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HomeMy WebLinkAbout998600007 Geotech Assessment GEOTECHN[CAL EVALIIATION OF TERMINATION POINT SUBDIVISION JEFFERSON COUNTY, WASHINGTON BY Leland B. Jones, P.E. & James B. Scott, P.E. December 1996 T~R~ .F, nF r(,~~ITENTS ~~~~i~u yi v 1 P~ 1 1.0 REPORT SUMMARY 2.0 PURPOSE AND SCOPE 3.0 PROJECT LOCATION AND SITE DESCRIPTION 4.0 PREVIOUS TECHNICAL REPORTS & CORRESPONDENCE 5.0 PREVIOUS I~~IVESTIGATIONS b.0 GEOLOGY 7.0 SUBSURFACE EXPLORATION 8.0 LABORATORY TESTING 3 b 8 9 12 15 18 19 9.0 ENGINEERING DISCUSSION 9.1 COMPUTER ANALYSIS 24 9.2 GROUND V~ATER 29 9.3 DRAINAGE 32 9.4 EROSION 35 10.0 CONCLUSIONS AND RECOMMENDATIONS 10.1 SUMMARY OF CONCLUSIONS 39 14.2 RECOMMENDATIONS 41 11.0 APPENDIX A 43 12.0 APPENDIX B 44 13.0 APPENDIX C 45 14.0 ADDENDIUM 1(dated January 17,1997} ,_ , . 4b 5 `~ Termination Point Plat Geoteehnical Report Page 2 l.~ REPORT SUMMARY During a meeting with Mr. Trask on October 9, 1996, the authors of this report were en a ed to conduct site studies, direct laboratory testing, perform analyses of information gg obtained from our exploration as well as by others, and prepare a Joint report covering the stability of the Termination Point property. In the report, emphasis was to be given to the lower portion of the property that is being proposed for residential development. The site explorations and analyses has been completed. This portion of the report summarizes results of the site studies. Discussions covering details of each item in the summary are also included in the body of the report. 1 The lower Termination Point property has been classified as "Critical-Unstable" in the Washington Department of Ecology Coastal Zone Atlas (Volume 11, July 1978}. This study and report addresses that topic. A discussion is made of site exploration and anal ses of surface and subsurface conditions that caused the site, in the past, to be Y unstable. Then recommendations are made for remedial measures needed to correct those conditions. A onion of the lower area became unstable during the winter of 1973-1974. Soon p thereafter, Mr. Paul R. Weber conducted site explorations,. made some laboratory classification tests, and prepared a report that discussed results of this investigation. In his report he says about a 1200 feet length of property was affected. Also high groundwater tables were generally found on the extreme ends of the bench, while the middle section contained only seepage zones. Unfortunately, Mr. Weber is no longer available for consultation about his work and some of his illustrations are not available. Since then, several other reports concerning stability of the lower .area have been prepared by others, based on reconnaissance of the site, but without the benefit of additional subsurface exploration. and testing. All of these reports conclude that the Lower area has been unstable, in varying degrees, and some of the re orts discuss corrective actions that might be taken to permit residential p construction. However, none of them provide any specific details for the corrective measures. During the site studies for this report, three rotary drill holes were drilled in the lower bench to recover continuous samples, to collect groundwater data, and to identify the geological structure (See Figure 3 in Section 6.0}. From below sea level to about 20 feet below the ground surface, the materials compared favorably with the geological structure identified in the higher ground landward of the bench by Associated Earth Sciences, Inc. red to be in lace with no indications of (1995 report}. These materials appea p disturbance that would be associated with sliding. The top approximate 20 feet of material is definitely slide debris and flow material that has been involved in previous sliding; in the westerly part of the bench, the material to a depth of about 23 feet is composed of this material. Termination Point Plat Geotechnical Report Page 3 u ii L In the westerly area there are two perched seasonal water tables.. One is in the undisturbed material above sea level, and the other is above a clayey .zone at the bottom of the slide debris. On December 5, 1996 the lower water table was 30.5 feet below the ground surface in both the westerly area and in the more .central area of the bench; the upper perched water table was found to be near the ground surface in the slide debris. High ground conditions was present in the westerly area, but was not present in the more central area. In the central area we found the water table to be at a depth of 38 feet in drill hole A-1 when it was sounded December 5th. There was no perched water in the upper zone. The extreme. easterly end of the_ bench `was not drilled, but a substantial amount of surface runoff was being directed into that area,. so it obviously has a high water table. Based on examination of samples, tests on disturbed and undisturbed samples and stability analysis, the slide and. debris flow material (Zone 5) on the. lower bench area. has by far the Lowest strength and it is most. subject to instability when the water table. is high. It is our opinion, based on observations of materials exposed. along the beach, and stability analyses, that ,~ ~~~. vvas ~n~itd -to Zane 5 materi~ tl~t Gov lr~lly ' tie top of the und~stu er yir~g ma ~`ur example, Boring No. 2 by Mr. Weber at 20 feet and in our Drill Hole A-3 at 23 .feet). That. could have lowered the ground surface 15 to 20 feet (as reported by eye witnesses), and .dumped slide material onto the beach. With this condition, the depth of sliding. could not have been observed. ~ stir ~,~ tti" ;; erasiA~ ghat und~1,4 the tae of the bluf~'and'caus~d'the initial slide and instability aft e s e c e'~rst . lower sees it wfll be necessary to install extensive drainage toy surface rat ~ er ound; a ctt to the tie ~ ~t `>"s faue drainage in the wester y.,.part o owear area., a will later he ~~ discussed. ~ ~ ~~ihyin t1~ ea~terri a is caused~~by heavy _a ro~tlnuous,~ ~~ .._....a...~„~.. - ~ ~ ~- . surface rung during wet weather, and tnat runof~~~o ger~e allowec~to d~schargq .~..~.....,.,..~.w,.-o.,..~...__...~ onto the lower area, subsurface clrarnage will not be neeT decd ~n t at are . however, in addition to drainage, rt wide necessary to provide an erosion control structure at the toe of the bluff along the beach to prevent further loss of the lower bench. Without this erosion control the lower bench will remain potentially unstable, even if the recommended drainage is installed, and stability of the upper. area could eventually. be threatened. Installation of the erosion control structure will not prevent some additional landward bluff migration above the. structure. The ground above the structure will continue to slough and span of until it reaches its natural angle of repose and is covered by protective plant growth. To account for this slope flattening, the set-back. for residential construction should be based on a control line with a slope of 1.5:1 (horizontal to vertical} toward the bluff and to the top of the ground, plus an additional width of not less than 25 feet for drainage, planting of vegetation,. and for a normal. UBC:Zone 3 seismic event. Drainfields should not be permitted within the set-back area. Termination Point Plat Creotechnical Report Page 4 i~ Based on our reconnaissance, examination of samples, laboratory tests, observations of ' groundwater levels, and stability analyses, it is our conclusion that the lower portion of the project would be stable, were it not for erosion at the toe of the bluff by wave action, except in one relatively small area centered at Lot 12. In this area, a surficial deposit of slide debris and flow material (Zone 5) became unstable during the winter of 1973-1974. This instability was caused by a combination of erosion at the toe of the bluff and high groundwater in the area as a result of heavy precipitation and runoff from higher ground. This runoff in addition to the regular precipitation saturated ground, .made the slide debris unstable. Stability is lowest when groundwater completely fills the ground above the Whidbey Formation (?). If drainage is installed as discussed later in this report, this instability can be corrected, provided the erosion by wave: action is also controlled. The entire project, including the lower portion, would then be suitable for residential development. Without both drainage.. and erosion. control, the lower. area. would still be ' susceptible to progressive loss of land and instability. Eventually the continued loss of land from the lower area could jeopardize the stability of the entire development. u L~ Termination Point Plat Geotechnical Report Page 5 2.0 PIIRPQSF AND SCOPE t The property known as the Termination Point Subdivision is within an area classed as being "Critical-Unstable" as indicated in the Washington Department of Ecology Coastal Zone Atlas (Volume 11, July, 1978). Based on the earlier classification by the ' Department of Ecology along with a landslide within the subject property reported to have occurred in 1974, Jefferson County imposed a building moratorium on the general area (including the subject property). Later, some of the other properties in the area, that ' had also been classed as "Unstable" and which were also located within the building moratorium area, were allowed to be developed. This .was done after a favorable geotechnical report (Previous report No. 5 by Thorsen) was issued. Based on that precedent, a request was filed for a permit to build a bulkhead along the ' shoreline of the project property as the first stage for future development. That permit was denied, based in part by a letter dated. April 18, 1996 from Mr. John Boettner, Washington Department of Fish and Wildlife, Area .Habitat Biologist, to Jefferson ' County, in which he recommended that the permit be denied, based on engineering and geologic factors. 1t should be noted that Mr. Boettner is neither a geologist nor an engineer, and in our opinion is not qualified to assess land stability or to make. other ' official engineering judgments. We are unaware of any valid reason or scientific analyses that would justify his following statements, '"In fact, this is the most massive rotational failure this Area Habitat Biologist has ever encountered," or "The geological instability in this area will result in continual failures of septic systems. The ..... failures will exacerbate problems with non point pollution ....." or, regarding bulkheads, "...this ' type of slope movement cannot be corrected by a standard bulkhead,'" or "Eventually, an emergency will be declared which will result in a buttress to protect the shoreline to the depth of the rotational failure, we estimated the rotational failure depth at that time to be 50 or 60 feet." These comments are presented as official expert opinions and are presumed to convey not only his opinions, but the.. official stance of the Department .that he represents. However, these commentsare not based on factual evidence, and since he is not qualified to make official engineering judgments, they may be considered serious violations of ' State of Washington laws. When they are presented as official expert opinions, they are misleading, and could have mislead Jefferson County officials in their assessment of the site. ' The u oses of this eotechnical evaluation are: p rP g ' (1) Determine the causes and extent of previous instability, especially in Light of 1VIr. Boettner's comments about deep rotational sliding. ' (2) Recommend appropriate. remedial measures to stabilize the property. Termination Point Plat Geotechnical Report Page 6 i (3) Determine whether or not once remedial measures are completed, the s to stability issue should be a consideration in future site restrictions. by Jefferson ' County. Termination Point Plat Geotechnical Report Page 7 ii f' r i LI 3.0 PROJECT LOCATION AND SITE DESCRIPTION - The subject parcel consists of approximently 24 acres of sloping terrain that is bounded on the south by the Squamish Harbor portion of Hood Canal, is about one-half mile west of the west abutment of the Hood Canal Bndge, and faces south looking down the Hood Canal. The legal description is that of a parcel located in the Northeast Quarter of the Northwest Quarter of Section 2, .Township 27 North, Range 1 East, W.M., in Jefferson (''nnnt~~ tx7~eHin~rknn The site consists of south sloping wooded terrain, having moderate to steep terrace slopes with narrow to wide, near horizontal terrace. benches. Elevations range from sea level to about 235 feet. The north side of the parcel is bounded by Shine Road, a county road. Three roads access the property: Ricky Beach Drive (to the lower terrace), Linda View Drive,. and Harbor View Place (to the upper terrace). The shoreline, which abuts' on the Hood Canal, shows extensive recent erosion with resulting slumps or slope failures (See Photo 1). In addition, the prevailing wind is from the south and results. in waves of various heights that are eroding the shoreline. Coastal .currents, depending what stage of tide exists, run both east and west along the shore line, but litoral drift from prevailing southerly waves, is easterly. To the east, as a result of litoral drift, sand has accumulated in the inter-tidal zone as a result of the west abutment of the Hood Canal Bridge obstruction. Termination Point Plat Geotechnical Report Page 8 a FIGURE 1-VICINITY MAP OF TERMINATION POINT SUBll1V1S1U1V ' 4.O PREVIOUS REPORTS AND LETTERS " , to 1 - " R rt Investi ation of Earth Movement Seaire Condominium Preliminary epo g , ' William S. Tsao & Company from Paul R. Weber, Consulting Soil Engineer, .dated February 5 1974 , .. 2 - "Field Inspection of Termination Point Area," to William S. Tsao & Company from ' Gerald W. Thorsen, Environmental Geologist, Department of Natural Resources, dated March 25, 1974. Geology of the Uncas-Fort Ludlow Area, 3 - "The Quaternary and Environmental . Jefferson County, Washington" (Thesis for M.S.) by Kathryn L. Hanson, University of ' Oregon, December 1977. Termination Point Plat" to John Flern from Neil 4 - "Landslide Condition on Lot 7 , T Welker & Associates, dated July 9, 1984. 5 - "Slope Stability Review of Pope Resources Property between Paradise Bay Road and ' Hood Canal", by Gerald W. Thorsen, C.P.G. No date shown, but after 1985. 6 - "Preliminary Findings from a Geological Reconnaissance of the Termination Paint ' Area, Jefferson County, Washington" to Mr. Phil Canter by Northwestern Territories, Inc., dated November 1990.. ' 7 - "Preliminary Permit to Drill and Test in Conjunction with Ground Water Application No. G2-274484", to Windermere Real Estate by Gale Blomstrom, Department of Ecology, dated May 12, 1994. $ - "Hydrogeologic Report, Termination Point, Jefferson County, Washington," by Associated Earth Sciences, Inc., 1995. ty", to Jeff . Shine Road Jefferson ~oun 9 - "Proposed Bulkhead at Termination Point ' _ , , _ Stewart (DOE) by Hugh Shipman, Coastal Geologist, Department.of Ecology, dated May 10, 1995. ' 10 - "Comments on R. J. Trask Bulkhead, Shoreline Substantial Development Permit (Termination Point, S2-T27N-R1E} to Jefferson County Permit Center by Peter Bahls, Habitat Biologist, Port Gamble S'Klallam Tribe, dated June 3,.1995. ' 11 - "Discussion of environmental checklist re ardin ro osed l~cement ~f ri rap", t¢ g gp P p A Jefferson County Permit Center by S. Vernice Santee, Environmental Review Section, ' Department ofEcology, dated June 7, 1995. Termination Point Plat Geotechnical Report Page 9 12 - "Termination Point. Bank Protection", to John Bosttner, Fish & Wildlife by Ken ' Bates, Department of Fish & Wildlife, dated June 21, 1995. ~~ - 1200 foot Rock Bulkhead', to 13 - Application of Pending Threshold Determination Jefferson County Permit Center by John Boettner, Habitat Biologist, Department of Fish ' & Wildlife, dated June 21, 1995. 14 - "Termination Point: Trask 1200' bulkhead proposal", to Jeff Stewart (DOE) from Hugh Shipman, Coastal Geologist, Department of Ecology, dated August 3, 1995.. 15 - "Discussion of proposal to riprap 1200 feet of Termination Point"; to Jefferson County Permit Center by Jim Pendowski, Department of Ecology, dated August 21, 1995. ' n ff s J b " er o e y , tion that E.I.S. be re uired b Terminal Investments 16 - Recommends q y County Permit Center, dated September 27, 1995 ' ' , to 17 - "Prelimina results of geotechnical reconnaissance of Termination Point project ry ' Barbara Blowers by J. B. Scott & Associates, dated April 10, 1996. " , to Mr. Russell. J: 1 Evaluation of the Termination Point Subdivision 18 - Geotechmca Trask by J. B. Scott & Associates, dated May 10, 1996. 19 -Complaint. regarding proposed development, to Barbara Blowers from Termination ' Point property owners, dated July 10,.1996. ~~ i n a ainst excessive 20 - Results of field inspection to select sites that require. protect o g erosion", to Russell J. Trask from J. B. Scott & .Associates, dated August 1, 1996. 21 - "Termination Point Site, Storm Drainage, and Erosion Control", prepared fore R. J. ' Trask by A.D.A. Engineering, dated August 2; 1996. 22 -Petition objecting to proposed development at Termination Point to Jefferson ' County Permit Center by Termination Point property owners, dated August 12, 1996. 23 - "Review of environmental checklist", to Jefferson County Permit Center. by Charles ' Gale, Assistant to Regional Director, Department of Ecology, dated August 15, 1996. 24 -Review of proposal to develop Termination Point area", to Jeffrey Stewart (DOE) ' from Hugh Shipman, Department of Ecology, dated August 15, 1996. 25 - "Discussion of request to repeal development moratorium for Termination Point Plat", to Jefferson County Permit Center from James W. Peason, Project Manager,. Jefferson County Department of Public Works, dated August 16,:1996. Termination Point Plat Geotechnical Report Page 10 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 26 - "Review of Pending Plat Alteration Application" to .Jefferson County Permit Center from John Boettner, Habitat Biologist,. Department of Fish & Game, August 18, 1996. 27 - "Geotechnical Inspection of Termination Point Subdivision", to Mr. Russell J. Trask by Leland B. Jones, P.E., dated August 19, 1996. Termination Point Plat Geotechnical Report Page 11 ~7 0 ii ii '~, u i. 0 0 i i 5:0 PREVIOUS INVESTIGATIONS The only investigation, other than our current investigation, that included deep subsurface exploration and a geotechnical review, was the. work done in 1974 by Paul R. Weber, P.E. (No. 1 in .Previous Report List) A .copy of that report is included in Appendix C. In his work, a series of four drill holes (for sampling purposes) were placed at random locations within the parcel. Based on the blow count data including inspection of material from sampled holes and data. from the penetrometer holes,. four cross-sections were prepared showing interpretation of data. Unfortunately, the plan view map showing the location of both the holes. and crass- sections is not available, so the locations as shown in Figure 2 are based solely on elevation data and where the hole or section appears to match the locations as indicated in discussion within the text of the report. Therefore, at best, these indicated locations are approximate. It should be pointed out that during the time interval between 1974 and 1996, much more is known about the reliability of data obtained from Dutch Cone penetrometer exploration. Therefore, .where penetrometer data exceeds a capacity of 50/ton/ft., the data is considered questionable, and data exceeding a capacity of 100 ton/ft., should not be considered.. Also, no samples are recovered by the Dutch Cone so it is impossible to identify a slide zone by that method. Im our exploration drill holes, one hole drilled adjacent to a location thought to have been the site of a penetrometer hole indicated that. correlation was poor to .none. It is for this reason that. the interpretation of slide zones shown (at deep levels only where over-consolidated material is encountered) in the cross-sections of Mr. Weber's report are considered questionable. However, the data provided by their investigation was invaluable in helping direct our. exploration program. In a number of cases, data obtained from our exploration .very closely match their data. It should be noted, too,. that the analysis of data from their investigation .did not disclose the presence nor indicate. the .potential for a large deep circular failure. A report written by Gerald W. Thorsen, prepared sometime after 1985 for Pope Resources, was the document used to lift the building restrictions imposed by the Jefferson County. It is quite comprehensive in .its coverage of the Pope Resources property located north of the Hood Canal Bridge. Mr. Thorsen discusses noth the Pope property and the property covered by this report. He points out that this is not a deep slide area, but has only superficial slides, similar to those discussed in this report. Based mostly on his report, the building restriction was lifted for the Pope property. However, it should be recognized. that geological differences between the two sites are more. ~ ~~ favorable for the property that is the subject of this report... ~ ~~ The re rt b Norman A. Dixon P.E.G. No. 6 in Previous Re rt List was re aced in Po Y ~ ( l~ ) p p November 1990. This report was .based on a very limited reconnaissance of the property. In summary, Dixon, a highly qualified geologist, claimed there was landsliding in the form of massive slump blocks. A "line of demarcation" is described and the statement is made that real. estate development should present. no unusual problems for Termination Point Plat Geotechnical Report Page 12 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 construction of homes. For our investigation, however, the most telling statements he made in his report were that the "landslide appears to be in or near equilibrium, but that erosion along the shoreline is active and could again destabilize the area." The report by J. B. Scott &Associates, a co-author of this report (No. 17 in Previous Report List), prepared in May, 1996, consisted mostly of surface observations. However, a series of shallow backhoe trenches were placed plus: a number of "hand drop hammer" undisturbed samples were taken for laboratory analysis. Many of the same conclusions that are given in that report after analysis of data generated from the current. investigation and discussed in this report, are the same. Termination Point Plat Geotechnical Report Page 13 .,, r ~. ~ . ~ P, ' i ' y ~ ~'" g Tw Z . ` ' 4 (' 3 ,~ g • 44 ~,, ~ • ~ X ~ ~ rto.oo' r V J ~ ~• t~ ' • ~" ~~., S L7~~ r+~~ttJ ~,~ ?. ,. 'Q ,: O s sa•/r• r•t ~ 4l A ~ ` • ~ P ~ V ti ~~ o •° h i .: s" \ ~ J B -~ 7 - •. ~• _ A 8 ~ ~ r 3. ~ y O ,, -• ~/ I ~ 41 i ?' 40 r' i ~- ~' ~, k ;ro ~ .. o ~ er /s~ ti ~• ~ A3 re [ t ;p.lO r~ ~ i~ gyp. ~ i !~ ~ ~ e• o, ~ ~. S 4 is ~ 8/ A ;8 10 ~ ~,{ j r _ .: ~' ! ~ •~• O r ~ i' h 'ZT 3 'E' EJo.B N 86 Noh: Plan We~v map redtuced from orl~inal map ' prepared by PAC-TECH En~lneerln>~, Inc. EXPLANATION B r 1974 1m c~ti~ati~rn = R»tan Ihlll I Inlc. ~I,r;ah»r, nhl,m~,rn:,4.1 P„ ~1 ®^ 'Z = Penetrometer I Iolrs t lucetinn ;,~rrl,.n» ~,Ic) m,,tct n,r ` I rl l , = C 1 ..,rrd , r_tihr,n rncc n :,PP rxss ,K:a u 1995 Im•e+Nentfon ' Tw-3 ~ = wAter well Iknl I I„Ic 1996 1Scott) Inve~Her,tion ur 0 _ rtnckhl><:n,Jd.r \:nn~lc 1,tc 1996 (Jmrc~-Srn~InvesNr~lion ' />!~. O - Rotnrc Ihlll I I,dc tilrc i~ = Crews ticction 'I'rnce A A` r, see 1 • /s. sz• • /30' • 6•/s•i4 ~~ Se,•Iw 1" = 210' ~ITF 1I.AP O ~' POR"PION Of TR:15k PARC'i?L PLAN ~'T F,V4' ~r SF:C`TI()N A-A' & 197~t-1996 SiTT21+ACE ~Nl) SI.IBSi.1RFACF, F,~PLOR.1TTOl~1 SIT 12RR196 2 ' Termination Point Plat Geotechnical Report Page 14 1 II 1 6.0 GEOLOGY It is our interpretation that the site geology is consistent with the general geological formations shown in .the AESI 1995 report. A profile representing site subsurface conditions is shown in Figure 3. Zones 1 and 2 are part of the Whidbey Formation (?) and Zones 3 and probably 4 are remnants of the Possession Drift (?). These materials we have observed elsewhere. Zone 5 is a deposit of slide and debris flow material that originated on the bluff slope between the .upper and lower areas of the project.. Because of the large amount of uncontrolled. surface runoff from the upper slope, this material was washed off of the bluff slope and probably moved as a series of mud flows and covered the top. of the Possession Drift (?) which is a remnant of an older series of terraces (described later in the section "Erosion".) This slide debris was deposited. in a loose condition, and where it is almost continuously wet from runoff, it has never gained its normal amount of strength. The slide debris materials are from the. Possession Drift (?) and the overlying Olympian (?) and originally extended to and beyond the bluff slope at the beach. It is probable that the slide discussed in 1VIr. Weber's 1994 report, is the area shoreward from our boring A-3 and was confined to the Zone 5 material.. Many of the .trees in this area are fast-growing maples that appear to be younger than the. slide .and the older trees may have been carried down with the slide. According to Dixon and Newlin (No.6 in the Previous Report List) the slide consisted of blocks "carrying nearly undisturbed and; intact portions of the forest cover with them". During our site work, we observed no evidence of movement of the sediments of Possession Drift (?) in the bluff above the beach. That portion of the site. appears to be stable now (except near the bluff where it is being undermined by wave action). However, since sliding did occur at thaf time, we have tried to determine why and how conditions then were different than now. Our conclusion is that since soil strengths then and now should have been about the (~t, same, the difference must have been in groundwater conditions. Water in Zone 3, as of ~J ~ d December 5th was standing 30.5 feet below the ground surface in the westerly area, but it was probably to the top of both Zone 3 and 5 during the 1974 slide. This higher water table would have reduced the stability substantially in Zones 3, 4 and 5 from that at present, considering the most critical condition is when groundwater fills Zones 3, 4 and 5 to near the ground surface. ,S (;~p~ !' ~#e ~'~ w~~vv hat Zone 5 hfa~r less strength than any other zone, so it i~' N l prvbl~ that the 19'14 slide was l~rnit~ et~to that zor~. In our analysis, we found that the 0 1974 slide involved a progressive .failure triggered by erosion at the toe of the bluff that ~°"a undermined the steep bluff slope. The undermining of the slope,. weakened by .high groundwater resulted in the failure of .the bluff. When the bluff failed, it removed lateral support provided to Zone 5 _by the outer bluff material, and caused Zone 5 to fail. It slid out over the underlying Zone 3 material in a series of blocks, as described by Dixon and Newlin. Since Zone 5 is about 20 feet thick, a slide limited to Zone 5 would correspond to the appearance of the slide, as described in eye witness accounts. Termination Point Plat Geotechncal Report Page 15 '(, w 0 c ~ o a c o ~ ~ o a 0 4 a 0 ° -- o 0 0 0 ~ ° z ~ ~- y o ~ ~ ~ r ' ~ ~' ~ fD o c • ~ v~ ~ '~ ~ ~ ?~ ~ S ~ o r ~ ° o d ~ ~ ~ ~ r ~ p ~ ~ ~ G ~, N c ~ ~ ~ ~ Q' o C ~ J ~ N y (11 ~ ~ ~ N O O • 1 D ~ N °o _ ~ ~ n • t ~` o , ~ ~~ ~ w ~. ~ ~ \ -- n efl ~ w 0 _ i ° ~ ~ ~ G~ - ~ ~ ~ • N ~.y v ` ~~ ~ ~ o~ ~ o a ~ ~ ~ ~ m F ~ ^ H ~ ~ 1.r.~ ICI ,~ A \~ , ~ ~ O O ~ ~ NO c ~ a , ~ ~ b Z F+ ; (fj t~ O Q z ~ ~ ~ z O o ~ ~ ~ ' ~ • • ~ ~ ~ ~ o ~_ ~ y ~ Y ' ~ ~ .r ~ b ' ~ A C ~ ~" ~ p ~ • ~ ego W ^ ~ i i • ry " ~ ' ~ ~ • „~~ H ( y ~ ~ _ ~ ' ~ ~ ~ ~ ~• „~, ~ ~ J ~D 1 ~' ( I ~ • 0 ~ ro f 1 • `'d ~ ~ ~ + ~_ ' ~ f9 ~~ o `' , ~ ~ ~ ~ i + °' ;~ • ~ t ~` + ~ a ~ ~ ~ ~~ ~ y ~ ~ ~ ~ , • • ~ A , i V! ~ O ' ~ • o n o ~ _ o ~~ t I o ~ ~ r rb ~ ~ ~ C r.+ ~ ~ ( ~ I ~ `O A ~ A • • ~ G. i~ UQ ~) ~"~ ~ d ~ 1 f W y ~ ~ ~ - `~ ~ p ~ ~ ~ : * rD d A v 1 ~ r ~ :A ao ~ -o: -- - -- --- - ------- -----~ ;~ W 1 It is also our opinion that the 1974 slide was limited to the area south of the scarp near Boring A-3. However, after that slide stopped, some movement may have continued in the remaining Zone 5 material landward of the scarp. Most likely this was a slow mass movement similar to that of a glacier. We have observed this type of movement at other sites where conditions are similar. This slow movement could have continued for some time, and was probably the movement described by Mr. Weber. We have not observed such movement in our borings which were drilled in October 1996. Based on this, we believe the cause of the 1974 slide was the great amount of groundwater in the lower part of the project in the vicinity of Borings A-2 and A-3. Therefore we tried to determine the source or sources of this water. First, we examined the logs of borings behind the bluff for water level observations, :and found groundwater levels to consistently be only about 10 feet above sea level. That elevation is close to the top of the Whidbey Formation (?) encountered in Boring A-3, and would neither provide significant pressure to influence sliding, nor. supply water to the slide area. We concluded that the only sources. of water in the lower area are precipitation that falls on that area and precipitation that falls on the upper area and then. flows down over the bluff slope. This means that the runoff from above is the primary source of groundwater in the lower area. The 1974 slide would probably not have occurred without the upper i area runoff Without the presence of high groundwater stability of the lower area would depend primarily on the loss of land resulting from the undermining of the bluff toe by erosion. ' During our site visits we have observed large areas on the bluff where the colluvium .has. been completely washed off, exposing the original in-place Possession Drift (?) and the Olympian (?) soils, so it is obvious that a large amount of water runs off he upper area and down to the lower area. This runoff saturates the ground in the lower mass, lowers the strength of the mass and lowers .its stability.. The material washed off the slope lodges on the surface of the lower area, adds weight, and further reduces. its stability. Much of this runoff water is retained in Zone 5 as perched water, because the relatively impervious Zone 4 clay layer acts as a partial barrier to downward flow. However, part of the water finds its way down through Zone 4 .and into Zone 3 and forms another perched water table above Zone 2. It is doubtful if the perched water table rises enough to completely fill Zone 3 during normal years. As mentioned above, we measured the top of the perched water to be 30.5 feet below the top of Boring A-3 which is several feet ' below Zone 4. While this has been an unusually wet year, even during wetter years Zones 3 and 5 may fill completely in which case the water pressure causing sliding would be the combined effects of the two perched water tables, or substantially greater than the ' combination of the two without Zone 3 being filled as shown in Figure 4, Section 9.2. The control of runoff from the upper area is vitally important to the stability of the lower. area and further recession of the bluff. Termination Point Plat Geotechnical Report Page 17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ?.0 SUBSURFACE EXPLORATION Drilling was conducted by Environmental Drilling, Inc., of Snohomish, Washington. The drill rig consisted of a Mobile B61-HD Hollow Stem Auger having a 30 foot tower. The three holes which were continuously sampled are: A-1 (44'), A-2 (29'), and A-3 (59'). Water was encountered in all of the holes, so piezometer tubing was installed in all three holes. In hole A-3 a system was installed to detect any horizontal displacement of more than one-quarter inch taking place within the span of the installed pipe. All the holes were backfilled with Colorado Silica sand adjacent to the perforated section of piezometer tube to assure good. permeability. The tubing above the perforations was sealed with bentonite pellets to restrict access of surface water to the hole. Each hole had a 12 inch diameter flush monument placed to protect the hole from vandals. Sampling was done with either stainless steel or brass 1.5 inch and 2.5 inch diameter liners and with 3.0 inch diameter brass Shelby tubes. Blow counts were taken while taking the 1.5 inch diameter samples. Drilling was done over a period of two days, October 21 and 22, 1996. The drilling foreman was Bruce b. McCall.. Termination Point Plat Geotechnical Report Page 18 n i 1 8.0 LABORATORY TESTING As mentioned in Section 6.0, GEOLOGY, the site explorations were intended to disclose typical soil conditions in areas that appeared to be stable, and in areas that had been involved in recent sliding or where sliding appeared to be possible. The laboratory tests are from samples collected from borings at the site.. Results of he laboratory tests were used for verifying visual classifications of soils logged during drilling, and for use in interpreting soil strengths for stability analysis calculations. Results of laboratory tests are summarized in Table 1. Test data sheets are provided in Appendix B, under Laboratory Results. Primary tests, such as moisture, density, gradation and plasticity are identification tests to assist us in evaluating expected .soils behavior with respect to stability. For example, dry sandy soils. area expected to be relatively stable, while wet soft clays with the same slope conditions, are expected to be less stable. Sandy or gravelly soils have greater shear strength than clays, but clays have cohesive strength and may have more total strength than the granular .materials.. Shear strength is the frictional resistance to sliding, such as the resistance to moving a chair across the floor. Cohesion is the glue-like or sticky nature of the mass. Sandy. and gravelly materials do not have a sticky nature and are not cohesive. Clays have both frictional resistance to sliding and a sticky nature, so they .have both shear and cohesive strengths. Their total strengths are combinations of the two. Direct shear tests with different .loading conditions, as conducted for this project, measure both shear strength and cohesion. On the other hand, tnaxial shear tests as performed for this project were intended to show total strength at confining pressures the same as where the samples were extracted .from the ground. These tests do not.. separate shear and cohesive strengths. The unconfined compression tests also show total strength, but since they are not confined, their strengths are essentially measures of cohesion. Thus the combination of all tests, both field .and laboratory, as well as site. observations, are necessary for evaluating soil strengths for stability analysis. Based on observations. and test results during drilling, materials vary in strength and weaker soils are likely to control site stability. For example, the lowest strength soils were found in Borings A-2 and A-3 above a depth of 20 feet. With high groundwater this zone could be expected to be more likely to slide. than the deeper soils that have greater strength. However, it was necessary to evaluate soil strengths in all zones, as well as other factors for the stability analysis. For this evaluation, in addition to site observations, we performed identification tests. such as: moisture, density and other classification tests, down-hole tests in undisturbed materials, direct shear tests, triaxial shear tests, unconfined compression tests, .penetrometer tests and Torvane tests. Direct shear .tests were used to evaluate ultimate strengths, triaxial shear tests were used to evaluate soil strengths prior to and during.. sliding. Unconfined compression, penetrometer. and torvane tests were used for evaluating cohension. The tnaxaial shear tests were especially useful for evaluating the influences of groundwater on soil strength. Termination Point. Plat Geotechnical Report Page 19 pR_IlVIARY TESTING Sample # Classification % Moist_ Density (~gp~~1 LL PL PI A-1, S#1 Si, SA&Gr 18.8 (3.7) A-1, S#2 Med-Fine SA 23.2 (17-18.5) A-1, L-1) Med-Fine SA 28.9 (22.5) A-1, L-4) Fine Cl SA 108.5 (43) A-2, L-1) CL-SI 26.8 112.4 (17) A-2, SH-2) CL 46.2 75.6 48 22 26 (17.3-18.5) A-3, SH-1 CL 25.1 106.7 26 19 7 (19.5-21) 35.9 89.6 A-3, SH-1 CL 36.7 96.7 45 22 23 (20.3-20.8) A-3, S#1 CL 32.8 91.4 42 20 22 SECONDARY TESTING Sample No: Moist. Dens. UnComp Direct. Triax Shear. .Stress (De t~h) % PSF TSF Shear Total Effec A-1, L-4 108.5 0.55 (43) A-2, L-1 26.8 112.4 0.62 (17) A-2, SH-2 0.62 (20) A-2, L-2 17.7 128.7 0.35 32 27.9 (22.5) A-3, SH-1) 30.7 96.7 29.9 33 30:1 (20.3 ) A-3, SH-1) 32.8 91.4 32.3 29.4 (21.3) A-3, S#3 20.7 (28) A-3. S#6 34.4 (48) A-3.L-4 36.5 96.3 2.03/2.43 PENETROMETER & TORVANE TESTING Penetrometer, TSF Torvane, TSF A-3, SH-1 (Depth 20.3) ~ 0.25 0.35. A-3, SH-1 (Depth 21.3) 2.5 0.7 TABLE 1-SUMMARY OF LABORABORY TEST RESULTS Termination Point Plat Geotechnical Report Page 20 i ~~ i. ii Some soils tend to compress during sliding. When the pore spaces in a soil are filled with air, the air can compress and the soil loses little or no strength. However, water is not compressible, so when the pore spaces are filled with .water, the soil cannot compress. and some of the soil strength is shifted to the water. Since water has no strength, the soil loses part of its strength and becomes more likely to slide than when it is dry. Wet, compressible sandy and clayey soils, such as most encountered at this site, lose some of their strength during sliding because some of the stress is shifted to the incompressible water in the pore spaces. The triaxial tests give two values. Test procedures were scheduled to provide strength data that would closely simulate the strength of the materials at the site for use in stability analyses. The triaxial shear tests were consolidated undrained tests on undisturbed samples, Prior to testing these samples were consolidated under confining pressures equivalent to those at sampling depths. These tests were conducted on samples at natural moisture and also, on saturated samples. At natural moisture, the test strengths approximate those where the material is failing above groundwater levels. When saturated, the test strengths approximate those where the failure surface is below the groundwater level. The effects of saturation were evaluated by comparing test values for materials at natural moisture and when saturated, Because saturated strengths simulate the soil strength with high groundwater during sliding, they were given the greatest consideration when selecting strength values for the stability analysis. These tests were conducted at the same or similar confining pressures, so they provide only the total strength that includes both shear and cohesion, but they do not provide specific shear and cohesion values. The direct shear tests provide. both shear and cohesion values on saturated samples, but because these are drained tests, results represent soil strength without significant effects of groundwater. The strengths of soils can vary within the same deposit, and there is no positive evidence that the materials sampled and tested are the most critical. Theoretically, the use of test strengths results in conservative results, but in practice they may not, because the soil at some locations not tested may have lower strength and control stability. Consequently, in determining stability values for actual design,. both the test values and experience with similar materials have to be considered. The more experience the .engineer has with similar materials and conditions, the. better his evaluation is likely to be. However, although conditions assumed for stability analyses may be close, they are not likely to exactly represent actual conditions, no matter how experienced the engineer is. Therefore, comparisons between different conditions, such as the various analyses for this project, must be considered comparative rather than precise. Although we consider their results to be reasonable and close to actual, they cannot be considered precise. It is more likely that conditions are worse than better than we assumed. For actual design it is necessary to assume that conditions are worse and include a "bugger factor"--so-called, "safety factor" to account for adverse conditions not included in the stability analyses. The amount of the "bugger factor" depends on to what extent the analyses are likely to be in error, and standards generally accepted by the industry. Termination Point Plat Geotechnical Report Page 21 As a means of trying to make the. best evaluation of the subsurface soils, some tests are performed in the borings where the soil is in place and has not been disturbed. Tests such as vane shear tests, Dutch Cone Tests, and Standard Penetration Tests are commonly used. Each of these down-hole tests is designed to provide strength data, but ' each gives empirical results subject to interpretation. The most commonly used down- hole test is the Standard Penetration Test (STP), (see Table 2 below) which is used to provide relative total strength, but is subject to interpretation because it does not provide ' definite shear or cohesive strengths. These tests also provide guidance as to .which materials should be sampled for laboratory testing. On this project we used SPT results along with .laboratory test data for estimating soil strengths to be used in stability analyses. During the 1974 site evaluation by 1V1r. Weber, the results were based on SPT tests, Dutch Cone Penetration tests, visual examination of recovered. materials, and a few ' gradation tests, but no other field or laboratory strength tests. That was not an unusual approach, but it does not provide the information needed for the more. precise evaluation needed to satisfy our requirements for evaluating this site .for residential occupancy. ' However those results, along with our site explorations and testing, were helpful during the development of our evaluation. ' RELATIVE DENSITY STRENGTH OF CLAY OF SAND Penetration Relative Penetration Unconfined Consisten-^_;~ Resistance N Density Resistance N Compressive (Blows/Ft) Strength (tons/ft) Soft 25 Ve < 0 - ry . 1 0 - 4 Very Loose 0 5 - 10 Loose 2 - 4 0.25 - 0.5 Soft 11 - 30 Firm 5 - 8 0.50 - 1.0 Medium 31 - 50 Dense 9 - 15 1.00 - 2.0 Stiff > 50 Very Dense 16 - 30 2.00 - 4.0 Very Stiff > 30 >4:00 Hard ' TABLE 2 -STANDARD PENETRATION TEST: 1-1/2 INCH ID SAMPLER DRIVEN 1 FOOT BY 140# HAMMER FALLING 30 INCHES ' It is ow opinion that the combination of ow field work, together with our laboratory test data and results of site work by others, have provided a reliable basis for the, site evaluation. During laboratory testing we observed the samples as to their consistency ' and apparent degree of disturbance. The portions selected appeared to be suitable for strength testing. These samples also gave us the opportunity of examining the materials ' in their natural state as to whether or not they had been involved in previous sliding, and their probable cohesion. The strength interpretation included down-hole tests, all of the information gathered. from other site observations, examination of materials as they were being sampled, examination of materials in the laboratory, SPT results, and laboratory test results. We Termination Point Plat Geotechnical Report Page 22 ' found site materials to be confined to three definite zones. The lowest zone,. designated Zones 1 and 2, is very hard and dense as shown by both Mr. Weber's and our testing. ' Our evaluation of this material was based on SPT results and unconfined compression tests. Zone 2 may be an old erosion or beach surface. The materials in this zone were observed to be in place with no indications of movement. Because the soils in Zones 1 and 2 have total strengths substantially higher than any. other site soil, more precise: strength evaluation was not needed for the stability analyses. ' The next principal zone, Zone 3, is located directly above Zone 2 and extends up to about 22 feet below the top of Boring A-3. The materials in this zone are flat-lying sediments that have relatively high strengths, although not as high as in Zone 1 and 2. Zone 3 is completely different than the lower ones. The materials in this zone are more sandy but contain silty clays and gravelly zones. These materials are medium dense. Zone 4 is a cla a zone, indicated b STP tests to be borderline between medium stiff YY Y and stiff.. Shear surfaces were observed in this zone. This zone is considered to be a ' portion of the Possession Drift (?), the same as Zone 3. Zone 5 has much lower strength than any other zone at the site and has been involved in recent movement. Zone 6 is the deposit in the bluff, landward of the lower portion of the proposed development and above the Possession Drift (?) formation. This zone was drilled for a water well, explored by Ivir. Weber in 1974 and explored by Associated Earth Sciences, ' Inc. (AESI) in 1995. The data from Mr. Weber's boring provides better information than other drilling and explorations. The borings. by AESI were air rotary borings with grab. samples to identify materials, .but because of our geological knowledge of the formations ' identified in these borings, we are confident that our evaluation of Zone 6 is reasonable. ' Of equal importance to strength of materials is the condition of ground water in the formation, and its. source or sources. Groundwater in Zone 3 in the bluff is very low--only about 10 feet above sea level (see Figure 3). Therefore, groundwater in this zone neither ' contributes to reduced stability nor causes any significant reduction in stability in the bluff or in the lower area of the project. There are no other groundwater conditions in the bluff of importance. Although there is a small amount of seepage along the face of ' the bluff a few feet below the upper ground surface, the influence of that seepage would only affect the thin layer of surficial material, not the stability ofthe entire bluff. ' Because groundwaterat this site controls stability, piezometers were installed in Borings A-l, A-2 and A-3. Because groundwater at this site controls stability, piezometers were installed in Borings A-1, A-2 and A-3. On December 5th, groundwater was standing in ' Boring A-3 at a .depth. of 30.5 feet below the ground surface, but at Boring A-2 the groundwater was standing just below the ground surface. In Boring A-l, groundwater was at 38 feet. No groundwater was found in Zane 5. We conclude that the .relatively impervious Zones 1 and 2 retain a perched .water table in Zone 3, and relatively.. impervious Zone 4 retains. perched water in Zone 5, but only in the westerly area. Termination Point Plat Geotechnical Report Page 23 7 0 L i~ 9.0 ENGINEERING ANALYSIS 9.1 -COMPUTER ANALYSIS - As discussed earlier in this report, the 1974 investigation suggested that combination rotational and block sliding had recently occurred when that investigation was conducted. Surface features certainly confirm that some type of sliding occurred. It should be pointed out,: that the. 1974 investigation did not detect any failure zone extending below sea level (See Report # 1 in Appendix C). Using subsurface data (drill hole logs). from that report as a guide for location of hole sites during the current investigation, samples from the three holes drilled disclosed the presence of material similar to those described in the earlier work. Also, as indicated in the earlier work, we found no evidence of deep sliding or of a rotational failure. To check the conclusions reached in the 1974 investigation and our initial geotechnical investigation, limit equilibrium slope stability computer modeling of a .portion of the slope on the Termination Point property was conducted. The mast probable location of recent sliding and whatcertainly appears to be the most unstable portion of .the parcel, was selected for analysis. This analysis was conducted by using the computer slope stability analysis program .called WINSTABL. This program is a modification. of the PCSTABL6 program, developed at Purdue University under a Federal Highway grant.. The program was then modified for the MS Windows95 program by the University of Wisconsin in 1996. This program allows for the use of four basic analysis methods: (i ) Specific Failure Surface, (2) Circular and Irregular Surface .Search, (3)-Block Surface Search and (4) Spencers Method. In the Circular and Irregular Surface Search method, three options are available. These are Circle (Janbu), Circle 2 (Modified Bishop), and Random (Janbu). After input is made into the program, the analysis will generate 100 trial computer failure surfaces and then plot 10 having the lowest stability. factors, with:. the lowest value being plotted out in red. ' Since. others (State and County reviewers) consider that deep rotational sliding has taken place, this would call for the Circle (Janbu) or (Modified Bishop) method of analysis. ' However, the one failure zone having been detected by subsurface exploration, appears to more closely match the failure surface that would be produced by the Random (Janbu) option. Therefore, that method of analysis was selected. LI The computer model requires the development of a unit width typical topographic and stratigraphic profile, perpendicular to the face of the slope being analyzed to provide: numerical input on proximity relationships and geometry of the site. The profile (Section A-A') used for this model was located, based on both topography and evidence. of shallow... (perched) ground water conditions, in the most probable. location for past slope stability problems and is presented in Figure 2. The selection was also based on 'the reports by Jefferson County personnel, that sometime in the 1970's, that landsliding resulted in a 20 foot vertical drop of Ricky Beach Road. The reported .location of that offset is about 50 feet east of Section A-A'. This appears to be the. most vulnerable location: on the .parcel.. In order to allow for the analysis to detect a deep failure zone plus uplift conditions in the inter-tidal zone, Section A-A' is 900 feet in length and extends from -50 feet elevation Termination Point Plat Geotechnical Report Page. 24 i J '~1 I~ fl ~i to + 150 feet elevation (see Figure 3 and in Appendix B, Figures B-2 .through B-8. This would show anon-bias attitude in conducting our analysis. Based on our evaluation of site observations, materials recovered from borings, explorations by others, and laboratory testing, we have designated the following strength. data to the various zones: 7.ONE DEPTH BELOW DRY/WET WT. PHI ANGLE COHESION TOP OF BORINGS LBS/CU FT DEGREES PSF A-2 & A-3 1 Below 48' 95/115 35 5000 2 45-48' 105/130 28 4500 3 23-45' 100/120 28 500. 4 18-45' 110/130 28 1000 5 0-18' 100/125 15 50 6 Bluff 130/145 33 2000 Note: See Figure 3 (page 16) for geologic profile TABLE 3 -STRENGTH DATA OF VARIOUS ZONES ' As discussed under Laboratory Testing, both Phi (shear) and .cohesion values were assigned for the computer analysis. Some of these values were later adjusted to better conform to field conditions. The values used in the computer analysis are shown as ' Table 3 under Laboratory Testing. In regard to input on groundwater conditions, certain assumptions had to be made, since several perched water zones were. known to exist. The basic computer model program allows for one water level or phreatic line level. ' However, it is possible to allow for multiple perched water zones by calculating .pressures by "pore pressure parameters". Because of the complexity of introducing multiple water zones, in the various conditions. we were going to assume, we elected to ' use the perched water zone in Zone 5 as the controlling groundwater level. Consequently, our analysis does not consider how a partially saturated perched water ' zone effects stability. The consequences of using of the one groundwater level verses several levels is discussed more fully in the Section 8.2, on Groundwater. ' In the following discussion of the various conditions considered in the analysis, it should be pointed out, that while perched water conditions exist, the analysis allowed for the upper perched water Level to be considered also as the piezo (phreatic line) level. This ' resulted in a more unstable condition for analysis purposes and the lower Stability Factor values obtained, would reflect that condition. ' Condition A - (See Appendix B, Fig. B-2) Conditions as existing as of 10/20/96 with no allowance for seismic event or erosion removal of toe material at sea level. Termination Point Plat Geotechnical Report Page 25 ' _ in as of 10/20/96 with no Condition B - (See Appendix B, Fig. B 3) Conditions as exist g erosion :removal of toe material but allowance for moderate seismic event having ' acceleration value of H = O.OSg. ' Condition C - (See Appendix B, Fig. B-4) Conditions allowing for perched water table ance for seismic event or erosion of toe material. ll N i d l l t ow o a r o groun . se eve Condition b - (See Appendix B, Fig. B-5) Conditions with perched water table lowered 10 feet by placement of drainage trench. No allowance for seismic. event or removal of toe material ' Condition E - (See Appendix B, Fig. B-6) Conditions with perched water table lowered by 10 feet and allowance for moderate seismic .event having acceleration value H = ' O.OSg, but no erosion of toe material. Condition F - (See Appendix B, Fig. B-7) Reconstruction of how .ground surface on ' lower terrace area might have looked before the 1974 landsliding that shaped the present topography. Perched water table was placed to the ground surface. No allowance was made for seismic event or erosion of toe material. " worst Conditions G1 and G2 - (See Appendix B, Figs. B-8 & B-9) For G1, analysis is of case" condition with estimated high {winter) perched water table on lower terraced area. ' No allowance for seismic event or erosion of toe material. G1 is analysis of existing slope under the stated conditions. G2 allows for (horizontal) loss of toe shoreward to the ' head scarp of the 1974 slide. Perched water table as of 10/20/96, but no seismic event. rintout of G2 the ten most possible computer generated failure t the com uter Lookin p p g a surfaces for G2 are shown with the potential failwe surface SF# 1 (having SF = 0.61 extending up on the upper terrace. SF#2, having a higher SF extends down to -50 feet ' elevation. This example, as shown in the Condition G1 and G2 analysis, is typical of how a failwe progresses with time. ' In the discussion of the various Conditions as generated by the computer analysis output, does not compute factors of safety for this site, but relative stability, as explained below. In any analysis of a slope, or as amatter-of--fact any engineering analysis, the factor of safety is based on a ratio of combined active forces verses strength of the material. The point where the acting forces start to exceed the strength of a material is considered ' equilibrium or SF 1.0. Any value below 1.0 is considered as being. in a failure mode. The lower the number, the greater the scope of failwe. However, values above 1.0, especially 1.00 to 1.05 can be deceptive in the case of slope stability of slopes, since seasonal changes in water levels and loading values can result in factors of .safety temporarily dropping below 1.0. That is why. most slope stability problems happen during the winter months and/or dwing a period of seismic shaking. Therefore, the higher the values are above 1.0, the better. At this site, all actual safety factors are above 1.0, except Condition G2. As previously discussed, bath Phi (shear) and C (cohesion) values were assigned to each zone of subsurface .materials for use in the computerized Termination Point Plat Geotechnical Report Page 26 stability analysis. These values are shown in the Table 2. These values were assigned on the basis of field and laboratory tests, as well as on our own experience with similar materials. The initial values were the same as in Table 2, except for Zone 5, where lower values were assigned. The original values were: Phi = 28 degrees and C ° 200 psf. Those values are considered more realistic than those now shown in Table 2. Using the initial values, static stability values were greater than 1.0 for all trial failure surfaces, which meant that with that condition, none of the trial failure surfaces would actually reach failure. However, for this study, it was considered necessary to demonstrate relative values of stability, so each condition could be compared with the others in that manner. Zone 5 has the lowest strength, and when that zone is saturated, it has the lowest stability. This being so, the other zones would have greater static stability, so in order to make comparisons relative to Zone 5 it was necessary to compute a static stability value of 1.0 for Zone 5. That was done by assigning a series of empirical strength values to Zone 5 and then back-calculating the .stability factor until a stability factor of 1.0 was computed. The resultant comparison between their stability and the stability of Zone 5 then became a ratio of stability.. If a trial failure surface had a computed stability factor of 2.0, that trial failure surface would be twice as stable as the weakest trial failure surface in Zone 5. It would not mean that the trial failure surface would have a factor of safety of 2.0 against failure. The strength values shown in Table 3 are the lower values used for these comparisons. ' Condition Location Description Seismic Stai~iiity Factor A Zone 5 Low Groundwater No 1.6 B Zone 5 C (Control) Zone 5 Low Groundwater Yes 13 High Groundwater No 1.0 D Total Depth Zone 3, High GW No 1.8 Zones 3,4,5 Zone 5 ' E Total Depth Same as D Yes 1.4 Zones 3,4,5 F Total Depth High Groundwater No 0.7 ' Zones 3,4,5 Prior to 1974 slide Gl Total Depth Same as C after No 1.0 ' Zones 3,4,5 1974 slide G2 Total Depth Same as E, 1974 slide No 0.6 zone removed by erosion ' S L ' ' ' ' ' TABLE 4 -SUMMARY YSI AIs1L1 I Y ANA UTEI~ZEli S I OF COlVIF ' As can be seen in the various conditions, Condition A through Condition Gi, assigning different input such as water levels, seismic .acceleration values, and. removal of toe material resulted in a wide .range of Stability Factor values. The assigned conditions, except for Zone 5 were based on what are considered very reasonable conditions based on actual events in the past. We allowed for periods of very heavy rain with a rapid increase in the perched ground water level. In some cases a rather moderate earthquake Termination Point Plat Geotechnical Report Page 2? ' - allowed. Finall allowance was made for a having an acceleration of H - O.OSg was y, major storm with high winds resulting in rapid erosion of the existing lower bluff slope. in ' conjunction with moderate ground water levels. You will note that in all of the conditions created, that no program generated failure ' surface having a Stability .Factor less than 1.75, extended below the Zone 2 horizon except in the case where erosion of the bluff toe was allowed.. In reality, most of the program generated failure surfaces were restricted to being in Zone S or limited in depth by Zone 4. It was only when we began to allow for toe removal that an increase in the depth of the failures is generated. It should be pointed out that the output generated in ail of the conditions considered, are very sensitive to both changes in groundwater elevations and. seismic accelerations. This ' sensitivity feature, when modifying input, provides a guide in regard to effective means by which stability factors can be improved. ~~' u ii You will note that in the analysis of Condition. A and D that the stability factors are almost the same. Yet in Condition D, the .perched groundwater was lowered by 10 feet from the groundwater level established for the analysis of Condition A. The reason only a very moderate change was .affected by the lowering of groundwater, is that even in the Condition A mode, the indicated failure surface never extended deep enough to encounter groundwater. Based on all available data, when relative values are compared, it is obvious that high ground water and erosion or removal of toe material by wave action are the. two main factors in the triggering of slope failures. Thus both surface and subsurface water has to be contained and .controlled and a bulkhead or sea wall has to be placed to dissipate wave energy and arrest erosion. If these two conditions are not modified, then failures will continue both from surface and subsurface water from upslope sources and erosion of toe material by wave action as shown in Condition G2. In time, the existing houses on the upper terrace may be in jeopardy. Termination Point Plat Geotechnical Report Page 28 I~~ 9.2 - ~~~Q[,I?~DW~4TER. Figure 4 has been included to illustrate the influence of groundwater on slope stability, especially at this location. Water in the soil produces a horizel force tovv-ard the bluff face, were there is no water Itress-ure in the other direction to counte-Tact it. That pressure has a triangular d~stnbut~on, and the total fore-~. depends on the height of the groundwater. The pressure is zero at the water surface, but the pressure at the bc~tQn} equals tl~ d~ptl~ of the groomwater tip thv unit weight cif the water. As shown in Figure 4, the resultant of the total horizontal force acts at 1/3 the height; it is calculated from the equation F = whf2, where F equals the total force, w equals the unit weight of water (62.5 pounds), and h eq:~ls the depth of water. When there is groundwater in the soil, this horizontal pressure- always .exists and is almost always responsible for instability of slopes, and the cause of landslides.. This same force is always present in all materials, whether they are granular car whether the, are clays, and it always contributes a horizontal pressure to the soil mass. The higher the pressure, the lower the stability. Groundwater is likely to he highest during the winter and spring when there has been a sustained period of heavy rain.. There has been a period of unusually heavy precipitation this last fall (1996), so the groundwater is probably unusually high now. Should there be another period of heavy precipitation, as expend in January, February, and March, groundwater could rise and completely fill Zones 3, 4, and 5 in the wet area of the lower portion of the site.. We have shown two conditions in illustrate the affects of groundwater in the lower area (below elevation 60 feet). Both assume a vertical slice of ground one foot wide that extends landward horizontally from the bluff, and both assume that there are two perched water zones. Condition 1 is where the perched water in Zone 3 is at Elevation 37 feet, Mean Lower Low Water, which is one foot below the bottom of Zone 4, so there is no horizontal water pressure in Zone 4. With this condition, the horizontal water pressure in Zones 2 and 3 equals 18,000 pounds, and the water pressure in Zone 5 equals 10,125 pounds. That results in a total horizontal force of 28,125 pounds against each vertical 1- foot wide slice. This force must be resisted by the soil strength in the bluff. The second condition, Condition 2, is where the groundwater in Zane 3 has risen only one foot higher than in Condition I, and. it completely fills Zone 5. However, water no longer "dribbles" down through Zone 4, but fills it. Since there is now a full water column from Zone 1 to the top of the ground, there is now full and continuous water pressure from the top of Zone 1 to the ground surface. Under this condition the water pressure assumes the triangular dist~ihution shown for. Condition 2. Now the. total. horizontal water pressure becomes 72,000 pounds in each one-foot wide slice. The very slight rise of only one foot in the perched water in Zone 3 has increased the total horizontal pressure more than 2.5 times aver that in Condition 1. That means that in a 100-foot wide lot the water pressure acting to reduce stability would now exert a horizontal pressure of 7,2Q0,000 pounds, and that pressure would have to be resisted by the soil strength behind the Muff to prevent sliding. Not only would the pressure increase in .this way, but the increase would be very rapid. It would increase in the short time between when it reached the bottom of Zone 4 and when it filled the seepage channels in Termination Paint Plat Geatechnical Report Page 29 Ele~~ation, Feet, _19LLt~~ c s ~" M d i ~ d v o tY N t~ n ..., ~ I ~ ~ E^ C ~ ~ ~ ~ a~ ~ ~ ~ i o~ ~ ~ ~ ~ ~ # ~ ~ I ( ~s ~ $ , z~ ~ I ~~ ~ ~ I H I 1 ~ I i I ~ K ,~ ~ I I I ~ I ~ ~~ ) c ~ p 0 '+ ~ N ~ Ii I ~ ~ ~ C ~ ~ c c u. p O p ~ W ~ ~] ~ p ~ d' ~ M ~ ~ .~ W a ~ ~, II N ap N~ ~ ~ I~ N o m W E... C O N L1 r W H od' ~ : cN ~ a °' Q .. ~~,~ ~ ~ W Q+ '~3~ r.+ o ~ c~ 3 N 0 ~ 3 z 3>~ ~ 3~° ~ ~ h z s.., ~ H p ~ o~ ~3 p o i w3 p O ~ 3 p ~, a r~ F F z c o ~ Termination Point Plat Geotechnical Report Page 30 Fig. 4 l i~ i~ ii 1 'J ii Zone 4. This high water pressure could be greater than the resistance to sliding by the soil strength along the bottom of Zone 3. Thus, consideration must be givem to the influence of groundwater on both shear strength and cohesion. Because of unusually heavy precipitation. during the fall and winter of 1974, we consider it probable that ground water conditions were equal to those indicated in Condition 2. If so, the relatively sudden high horizontal water pressure in combination of erosion by wave action could have caused a block movement close to the bluff in the soil mass above Zone 2. This movement could have triggered movement in Zone 5. Because of the soil types and the low. density material in Zone 5, this movement could have caused the material in Zone 5 to partially liquefy, and fail as a mud flow. That would explain. the drop in the ground surface shoreward from the low scarp near Boring A-3, and the undisturbed nature of the Zone 3 material that is exposed along the face of the bluff above the beach. ANALYSIS - From this analysis we conclude that the groundwater in the westerly area must be controlled so it does not rise high in Zone 5. Since we know that the sources of groundwater in all zones are from precipitation, primarily that of rainfall on the area between Shine Road and the bluff landward of the lower area, it is necessary to provide the drainage required to intercept that water, as well as to provide subsurface drainage to prevent high groundwater from developing in Zone 5. If all of this drainage is not provided, the lower area will remain potentially unstable. If drainage is provided and a suitable bulkhead or riprap is placed, the lower area will be stable and suitable for residential construction. // ,,,~ ~ c-~-> C C ~ ~ ~~V~ ~~ ~ g~ 1 ~ ; _~ ~ ~. ~~ ~~ ~ 4~ ~ i ' Termination Point Plat Geotechnical Report Page 31 ' 9.3 DRAINAGE Ade uate drainage is needed, both on the higher and lower q portions of the project. As presently exists, relatively impervious material a few feet rates t th t bl t d w sa u a e ater a below the ground surface in the upper area. creates a perche the ground to the ground surface during periods of heavy precipitation, and this. high ' water table interferes with drainfield operations, as well as use of the ground. To correct and subsurface drainage construction of surface mmendin diti thi . g on, we are reco s con ~ along the southerly side of Linda View Drive (See Figure 5). F,~ ~ee~:~~. ,~ ~k~ s ~ ~ ~ ~«5 ~'t`"~" `~ k~ ~ a 1 ~"^' ' Armor ditch with -4" rock ~ . 2:1 , ~ ~ , 4:1 - ~ ~~ i~~ ~~ GJ'J ~ ~ r ~°> ~ ~,,, 1 1 ~~`~ s~ ~"-~ / / j ~% Impervious zone ~ pipe ~~ ~~~ ~~ ' ~ Note: Depth of ditch and subsurface drain pipe is variable Scale 1" = 2.0' Q ~ ~~~, ~ ,'t FIGURE 5 -TYPICAL DITCH SECTION SHOWE'~G SURFACE AND SUBSURFACE DIIAIN The surface drain would be a normal roadside ditch to collect"runoff from the road and keep it from flowing toward the bluff. The subsurface drain should be a perforated pipe ' placed in a trench that penetrates to the impervious materi~.l, is embedded in properly designed filter material, and is sealed from surface drainage. The surface drainage from the road would need to have contaminates removed, but the other surface and subsurface drainage would not... Low cost ABS 8-inch diameter pipe would be suitable for the pipe, but it should have slotted. perforations.. Pervious backfill around the pipe should be ' crushed rock graded from fine sand to about 3/8 inch maximum. The top two feet of backfill should be the most impervious material available .from the trench excavation. Both drains would follow the. same alignment, and the perforated pipe drain is expected to be five. or six feet:. deep, depending on conditions actually encountered during construction. This drainage would follow the natural slope of the ground, so most of it .would flow easterly toward the natural drain west of the intersection of Shine Road and ' Rickey Beach Road where it would be discharged into that drain. Termination Point Plat Geotechnical Report Page 32 i ~I fl 0 I~ i i Water in this natural drain would be collected before it enters the 12 inch culvert through the access road fill, and passed through a 24 inch culvert that is constructed along the northerly side of the road, then across stable ground near where. the roadgrade flattens, .and then to the bulkhead along the toe of the bluff. The water would. then enter a dispersal system, where it would seep through the bulkhead. Design of this dispersal system is described below. A similar method for disposing of the surface and subsurface drainage should be installed at the westerly end of the bulkhead. Properly designed and. constructed drainage is critical for correcting stability problem in the lower project area. This drainage would involve collecting drainage from the higher.. ~ ground, between Linda View Drive and the top of the bluff, controlling surface drainage ! on the lower level, and installing subsurface drainage to control ground water. The upper ~~; ~* level drainage .would consist of a ditch or Swale northerly from the top of the bluff to collect surface runoff, and a subdrain to intercept subsurface drainage .before it surfaces ~~t on the bluff slope and flows onto the lower area. Surface drainage on the lower level ~ ~ should include control of runoff from roofs, driveways and roads. Subsurface drainage on the lower level should consist of installing a relatively deep drainage system: in the vicinity of Borings A-2 and A-3. The drainage system in the higher ground near the top of the bluff should be similar to that along Linda View Road in that an open ditch or Swale .would intercept the surface flow toward the bluff, and a subsurface pipe would intercept .ground water flowing toward the bluff. As along Linda View Road, this drainage would flow both easterly and westerly depending on the ground. slope. The design of the subsurface drain should be identical to that along Linda View Road. The surface drainage should be located far enough back from the bluff to not be damaged should the bluff continue to slough and recede further north. This distance. from the side of the excavation for the drain bluff should be no less than 25 fee , rt should have a minimum ept of three feet for ' freeboard against overflow and it will need. to be armored. The trench excavation for the subsurface drain should extend down into the underlying impervious material at least one ' foot. It is expected that this trench will be 5 to 6 fee. deep, but its actual depth will depend on the depth to impervious material during construction. C The subsurface drain location and design on .the lower area were discussed with A.D.A. Engineering. Tt would be about 40 feet north of Boring A-2 and extend both easterly and westerly about 75 feet. This drain will be constructed with the same materials to be used in the two drains on higher. ground, but it should. be deeper to intercept the. groundwater seepage in the slide debris of Zone. 5. During our drilling and sampling operation the ground was too soft and wet for access to the trench location, so the actual depth is not known. However, it should extend only to the top of Zone 4, which should not be penetrated. Zone 4 is relatively impervious, and retains perched water in Zone S. That is the water to be intercepted. If the trench should be too deep and cut through Zone 4, it would allow seepage into Zone 3. The additional water would raise the water table in Zone 3 and increase seepage forces in Zone 3. Since water seeping from Zone. S through Zone 4 to Zone 3 is the source of water in Zone 3, the subsurface drain needs to be ~k~ ~~ (~. `~ ~~ ~~ . / ~~~ ~r~~ `' ~ ~~~7~ ~, Termination Point Plat Geotechncal Report Page 33 i ~~ 0 ii ~~! C carefully constructed to minimize seepage into Zone 3. The depth to Zone 4 would probably be about the same as it is at Borings A-2 and A-3, and it might be less. Since the drain construction would begin at its exit point south of Boring A-3, it .will be necessary to explore the depth to Zone 4 at the drain trench. From the center of the trench the .discharge pipe will be routed to the dispersal system along a lot line. This construction would have to be during the driest summer weather to minimize the trench excavation. We should be retained to provide details of the subdrain design and specifications. Roof and other surface drainage needs to be controlled so as to minimize seepage into the ~ ~a a ~°~ o'~~~ ground.. Road and driveway drainage can be routed to catch basins, where it can be piped ~~ ~ to an oil collector and then to the dispersal system. Details of this drainage should be ~ ~. ('~' designed before construction begins on each. lot. v The dispersal system mentioned above should be incorporated into the bulkhead or riprap erosion control structure. Fill material behind. the rock surface would be crushed rock {and spans if a bulkhead is constructed.) The crushed rock behind the riprap would be graded from fines to 1 1/2 inches, and would fill the entire"space between the rock and the beach and the bluff. The same crushed rock would be used behind the bulkhead, but because of the larger void spaces in the bulkhead a two to three foot wide spans zone would be constructed between the crushed rock and the bulkhead rock. During construction of the riprap or bulkhead a 2-foot diameter perforated CMP or plastic pipe (preferably plastic to resist deterioration by sea water) would be embedded in the crushed rock about two feet below the top of the structure and for the length of the structure to disperse the drainage water. Drain pipes could be connected to this .pipe wherever needed. One advantage of this .type. of system is that it avoids concentrated flows of drainage water onto the beach. Termination Point Plat Geotechnical Report Page 34 it 0 C~ I~ 1 ~r'! ~~i n 9.4 -EROSION Erosion by wave action has been the greatest factor influencing the stability of land masses in the Puget Sound area. This erosion has taken place at various levels above and below the current sea level since the last glacier receded some 13,000 years ago. Sea level is controlled by the amount of polar and local glacier ice. During ice ages when there is a great amount of polar ice, sea water is trapped in the ice and the sea level lowers. In the Puget Sound area, sea levels were possibly about 500 feet lower during the last ice age. Then as the ice age ended and the ice melted, .the .glaciers receded and the ocean rose. There was also a time, probably back over a period of several thousand years, when the ice cap melted back much farther than now, and the ocean raised to high levels, possibly as much as SOO feet above the present sea level. We have observed compelling evidence of higher. ocean levels. For example, we found sea shells at Elevation 175 feet near Ferndale,. and at Elevation 200 feet during construction of the Port Angeles airport. During those lower and higher periods the levels evidently. remained nearly constant at different levels for many years. They eroded the ground at those various levels, and created wave-cut terraces. The size of those terraces depended on how long the water remained at each level. Although many of these terraces are not obvious to the casual observer in the Puget Sound area because of timber cover, they can be observed if the observer looks for the signs. 'These terraces are world-wide, and we have observed them at the same elevations in the Orient, South America, and Europe, as well as in the Pacific Ocean and Caribbean Islands, and on the Atlantic, .Pacific and Arctic coasts of North America. The flat ground in the commercial part of Port Townsend is a remnant of one of these prominent wave cut terraces that can be seen all around the world. Many terraces at about the same elevation can be seen elsewhere in the Puget Sound area. One prominent terrace observable in the Hood Lanal area is at the level of the southeast end of the floating bridge approach at about Elevation 80 feet, and another is about Elevation 40 feet. These terraces can be seen for many miles along the southerly side of Hood Canal. In many places these lower terraces have been completely eroded. away where they were exposed to the most severe wave action, especially along. much of the northerly shoreline of Hood Canal, where there are long. fetches of open water. The low area on this project is probably in one of these terraces. While the ocean level was at the higher elevation that created the terrace at about Elevation 40 along the south side. of the canal, wave action cut a terrace into the Possession Drift at about Elevation 40 feet in the ~ lower area of this project. This erosion formed sort of an amphitheater with a steep bluff ~ .~ slope above the terrace between the upper and lower areas. This is the bluff slope from ~~ ~G~ which the colluvium has been washed by runoff from the higher ground. off` ~,~'~~ ~~i Wave action has been attacking the land around Puget Sound since the last giacier~ ~ ,? ,~ receded, has caused enormous loss of land, and severe damage to the original ecology, ~~ ~,~~`~, as can be seen from soundings on navigation charts, and this erosion is still continuing ,~ ~~ unabated except where shore. protection has been provided. In addition to the. terraces ~~ ~` that can be seen above the present. ocean level, wave attack and extensive erosion have ~' occurred at several principal levels below the present water surface. Two of these levels Termination Point Plat Geotechnfcal Report Page 35 ~~I f ~~ ii are apparent from terraces at about Elevation -100 feet, and the other at about Elevation -30 to -50 feet. For example, about 3/4 mile of land has been lost on Whidbey Island at llouble iilutf and about two miles has been lost at Scatchet Head where there are long southerly reaches of open water. At Foulweather Bluff a terrace about 50 feet deep extends 1/2 mile from the bluff and a 100 foot deep terrace extends out almost a mile: Most of the terraces near Double Bluff and Scatchet Head, are about 35 to 40 feet below sea level. The prevailing Puget Sound winds, including almost all storm winds, are southerly. Shorelines exposed to these winds are especially subject.. to erosion. The erosion was more severe along the northerly side of Hood Canal than along the. southerly side, although not nearly as much as in the more exposed Puget Sound areas. Also the northerly side wave attack has eroded away many of the lower terraces, whereas they still exist on the southerly side. Figure 3 has been included in this report to illustrate how wave action has eroded away a substantial amount of land below the existing ocean level in the project area. This figure is based on project topography above the beachand NOAH Navigation Chart No. 18461, ' "Hood Canal, Port Ludlow to South Point", for underwater topography. As shown in the profile there are two prominent underwater terraces, one at about 100 feet and the other. that starts about 20 feet below sea level. This erosion appears to have caused a loss of more than 1,800 feet of ground. All of this erosion has occurred since the last glacier receded. The erosion is continuing today in the project area, probably at an average rate of from 1 1/2 to 3 feet per year. If this erosion is allowed to continue, it will result in a ' continuing loss of land, reduction in stability of the ower area, and .eventually in `the stability of the upper area. ' In some cases erosion of bluffs is credited with enhancing the beach environment, especially when the eroded materials are. granular and their deposition is perceived to improve the natural beach condition. However, erosion at this project provides no ' discernible benefit, but inflicts .considerable damage. The eroded materials are nearly all fine grained, largely silt and clay, and. they do not provide beneficial deposition because of conditions created by the floating bridge fill that is only about 1/4 mile eastward from ' the project. The prevailing winds result in littoral drift toward the bridge, where lateral previously eroded materials have filled in a triangular .area as far out as the end of the boat ramp beyond the bridge fill. Now eroded material is being carried past this wedge ' of material into deep water, where it provides no benefit to the environment. EROSION CONTROL Although there is a misconception that erosion along. the shoreline can be controhed by .planting, we have not observed even one example of planting. that has been successful for this purpose. Plants that would have sufficient .cover and root structure to control erosion would have to be upland plants that do not thrive where they are .subjected to salt. water ' attack. Along the shoreline there is a line of vegetation that is used to designate the ordinary high water line. Often at this project, this line of ordinary high water is along the lower part of the steep bluff slope above the beach, where .plants do not grow (the Termination Point Plat Geotechnical Report Page 36 1 u I'~ I ~~ ~~I! ii L basis of defining the ordinary high water. line j. To prevent erosion along property such as this, it is necessary to construct an engineered structure that is capable of resisting the wave action that occurs at the site. The structwe must have sufficient strength,. resist deterioration, and be high enough to not be overtopped by waves that would erode the ground above the structure. We do not recommend wood structures because of their limited life. Steel structwes such as sheet piling have sufficient strength and resistance to deterioration, but they have the disadvantages of not being free. draining, and. they must have high top elevations because of wave run-up. For example riprap with a 2:1 slope (horizontal to vertical) has wave run-up of one wave height; whereas, the wave run-up is two wave heights for a vertical sheet pile wall. We are aware that some public agencies are opposed to bulkhead construction.. on the basis that it causes deterioration of the beach, damages fish propagation, and. eventually fails because of undermining. During many years of experience with shoreline protection with riprap or bulkheads, we have not observed such deterioration or failwes. With respect to the finer material often seen along the base of bulkheads, the same condition is seen along the tops of most beaches without bulkheads or riprap. Also the only bulkhead failwes we have observed were those constructed on soft ground along the toes of active landslides, or where they were not sufficiently.. embedded in firm foundation material. It is our understand that the basis for .most of their opinions concerning erosion control come from studies along the Atlantic .Coast, where soil and exposure conditions are vastly different than in the Puget Sound area, including that at this project. It should be further noted that there has never been a specific study conducted along Puget Sound that demonstrated such deterioration or failwe of properly designed and constructed bulkhead or riprap structures. It is our opinion that a careful and unbiased study would demonstrate the suitability of bulkheads along most of the Puget Sound shorelines. A prime candidate for such a bulkhead study would be the bulkhead along the Bwlington Northern Railroad between Seattle and Everett. This bulkhead is many miles long in one of the most exposed reaches of Puget Sound. It is constructed of large granite blocks and it has near-vertical slopes. It was constructed nearly 100 years ago and has neither failed. by undermining nor has it caused a deteriorating beach. Yet there are no feeder bluffs along .this bulkhead to replenish beach materials or protect fish habitat. It is also ow opinion that the only acceptable means of erosion control at this site, both financially and structwally, is by constructing either a rock bulkhead or a riprapped fill. Either type of structure would be suitable, provided it extends along the bluff the full length of the project. A shorter or intermittent structwe would not be suitable because the erosion conditions beyond the ends or within gaps in the structwe would continue to undermine the bluff, and lead to adverse hydraulic conditions. This structwe would not be designed to buttress the bluff slope; after the drainage is constructed the bluff above the bulkhead or riprap would be stable, except from surface sloughing. Of cowse, even Termination Point Plat Geotechnical Report Page 37 b / ~,, 1 1 1 1 1 1 1 ~°~ P~~" ~~ u i f a bulkhead or riprapped slope is constructed, the bluff above the structure will continue ~ to slough until it is protected with sufficient ground cover and reaches its natural angle of repose. In addition to providing erosion control, the bulkhead orriprapped slope would provide the added benefit of providing the means for dispersing drainage water as discussed in the section, DRAINAGE. If either a bulkhead or a riprap structure is constructed, it should have a top elevation consistent .with a 6-foot high design wave and a design tide level of 12 feet, or Elevation 18 feet MLLW. If riprap is used it should: have a slope of 2:1, an average rock size of two feet, and crushed rock fill. If a bulkhead is constructed it should have a slope not steeper than 1/2:1, 3-foot minimum size rock, a spalls zone and crushed rock backing. We are available to provide design details and specifications for either type of structure. Termination Point Plat Geotechnical Report Page 38 [] 0 10.0 CONCLUSIONS & RECOMMENDATIONS 10.1 SUMMARY OF CONCLUSIONS CONCERNING DEVELOPLMENT OF THIS PROPERTY FOR RESIDENTIAL OCCUPANCY:. 1. All of the lower portion of the project is being jeopardized by erosion of the bluff by wave action. A great deal of land has already been lost because of erosion by wave action, and this erosion is probably progressing landward at an average rate of between 1- 1/2 to 3 feet per year. This erosion was a significant factor in causing past slides in the lower area, and if not controlled, will continue to cause instability. 2 . The only financially and structurally viable erosion control system would be a riprap or bulkhead structure. Other structural systems would not be suitable or economical. Planting to control erosion is not practical, because no plants capable of resisting wave action at this site will grow in the salt water environment that exists along the shoreline. ' 3 . Without both erosion control and seepage control, the lower portion of the project, and eventually the-upper part, will continue to be subject to instability. ' 4. Surface water control is need to intercept runoff from the higher ground. This runoff is the principal source of high groundwater in the lower area. Based on our observations and limited subsurface explorations, the unfavorable groundwater condition that needs ' correcting is limited to a relatively small lower area in the westerly part of the project where subsurface drainage is being proposed.. Once the surface drainage system is in place and surface water is cut off from entering the easterly portion of the project area,. groundwater conditions in that area will then be favorable. Therefore, a subsurface drainage system will then not be needed in the easterly area. ' S. The material behind the bluff and below about Elevation 40, in the lower, Zones 3 and 4, is of sedimentary origin, and appears to be part of the Possession Drift (?). According to age dating in other areas, this material was deposited about 40,000 years ago. The material above the Possession Drift (?) and above about elevation 40, (Zone 5), is a combination of slide and debris flow material that originated from the bluff slope, except the nose landward of Drill Hole A-1. That material appears to be a slump of sandy material from the upper part of the bluff or from similar material near the ground surface between Linda View Drive and Shine road. We detected no evidence of a water table in this material. 6. There is a large amount of surface and subsurface runoff, including that from roads, ' that finds its way to Hood Canal under present circumstances. The proposed drainage plan is intended to collect such drainage, remove contaminates, and distribute it along the proposed shore protection structure so it would not discharge in concentrated flows. ' 7. We have carefull considered our site observations, reviewed boring data from our Y explorations and from explorations by others, read reports by others,. and considered Termination Point Plat Geotechnical Report Page 39 1 1 1 1 1 1 1 1 1 1 i 1 1 1 1 1 1 i results of laboratory tests to arrive at probable strengths and groundwater conditions now and at the time. of the 1974 slide. These results have been used to formulate our opinions.. about the 1974 slide event, and to arrive at our conclusions about the present stability and the stability after the proposed surface and subsurface drainage is installed. 8. After the shore protection, and surface and subsurface drainage is installed and. is acting to control the water table, the lower area will be stable for -residential construction. The potential for sloughing along the bluff above the erosion control structure will have to be considered when siting structures. Over a period of time the. bluff. top may progress landward to a slope of 1-1/2:1 (horizontal to vertical), and there should be an added distance of not less than 25 feet for set back to structures for planting and other local runoff control. Termination Point Plat Geotechnical Report Page 40 ill C~ I' 9.2 RECOMMENDATIONS: We recommend that this site be approved for residential construction, subject. to the following provisions: 1. The first project work should include the construction of a properly designed. erosion ~~ control structure for the full width of the project along the toe of the bluff. This structure ~~~J~ ` would incorporate a dispersal system for distributing surface and subsurface runoff. to the beach from the project. 2. Drainage should be installed along Linda View Road and along the top of the upper bluff, following the general design for such drainage. as described above. 3. After the upper drainage has been installed, and the ground water in Zone S has receded sufficiently, as determined from observations, subsurface drainage should be installed as described above. 4. ° ccrostru~tion in the lower area should not c©rnmence until the subsurface 1 dra Wage ~s installed and groundwater in Zone 3 can be observed forVe~~~tiveness durityg the ~;~rt ~a~l and winter rains. 5. Residential construction including drain fields, should be restricted to areas landward of the set back for bluff recession and the buffer zone,. as described above. ~~ 1 1 6. We recommend that we be retained for developing drainage design details, design of the erosion control system and drainage dispersal system, .and evaluation. of the effectiveness of the drainage system. This geotechnical engineering report has been prepared in accordance with standard practice in the industry. Its conclusions and recommendations have been developed from. our interpretation of subsurface conditions, as ..disclosed by surface observations.. subsurface boring information, laboratory testing, and previous reports by others. l~e:~~aze inherent differences in subsurface„ :~: i ' i,~closed from bori g ,,...~.,~..,,,.,~,.,.e_ m~ ~~nt than actual, conditions. that exist at the sitd. Although we believe: our interpretations to be correct, and our conclusions and recommendations to be reasonable, trust -accept the perssibilit_y that subsurface conditions ct~uld be different tha~i _~.. ~:~`~ tnte~ feel and modifiea~ons mig e nee e a er o a ose i ferences. W~ . _M... ~.....,,~„~...~,~...._..e_,_ .. make no ari , s e ar ot~ierwise, that we are responsible for events that occu~° o~ _.~.,_ _ w.~,. ~£ ~~ercatiorrs that iriiglit~e needed as a result of such differenee~'. Termination Point Plat Geotechnical Report Page 41 ~~v Leland B. Jones, P.E. al wt.~ J mes B. Scott, P.E. ~:..~ ~'' ~~ wAS.y ~~ ~~ s~ Csj a~'~i~'s ~4 a r~ ~6~.~ /~ ~. N3~0 ~~~tN~TA'L:~ EXFiRES ll~®• Z Q/17/ ~ 7 4s~~, d...._,_._.. i~ti ., T.eland B. Jones, P.E. James B. Scott, P.E. Termination Point Plat Geotechnical Report Page 42 11.0 APPENDIX A 1 -Leland B. Jones, P.E. -Experience Statement 2 -James B. Scott, P.E. -Experience Statement Termination Point Plat Geotechnical Report Page 43 12.0 APPENDIX B 1 -Computer Analysis Output ' 2 -Drill Hole Logs ' 3 -Laboratory Test Data Sheets A -Advanced Soil Mechanics ' B -Soil Technolo ,Inc. gy ' Termination Point Plat Geotechnical Report Page 44 :3A APPENDIX C 1 - "Preliminary Report, Investigation of Earth Movement, Seaire Condominium", by Paul R. Weber, Consulting Soil Engineer. 2 - "Slope Stability Review of Pope Resowces Property between Paradise Bay Road and Hood Canal", by Gerald W. Thorsen 3 - "Preliminary Findings from a Geological Reconnaissance of the Termination Point Area, Jefferson County, Washington", by Northwest Territories, Inc. 4 - "Geotechnical Evaluation of the Termination Point Subdivision", by J. B. Scott & Associates. Termination Point Plat Geotechnical Report Page 45 ~i C ~J C ~l 14.0 -ADDENDUM NO.1(Dated January 17,1997) TERNffNATION POINT RESIDENTAL DEVELOPMENT The report dated December 1996 (except for this addendum) was drafted prior to the destructive 1996 Christmas Holiday storm. Had it not been for that storm, which. prevented obtaining the last set of water level readings; review of the final draft; and word processing necessary for its publication, the report would have already been completed and issued. The report was based on surface observations, information from subsurface explorations, and personal experience. Now we have had the opportunity of observing the effects of the storm at the Termination Point property, and the inclusion of those observations in this addendum. Site observations were made January 6, 1997. During that reconnaissance, we looked for indications of sliding in the lower. part of the project, observed and photographed many debris flows that originated on the bluff between the lower and upper parts of the property, observed erosion and sliding in the parcel .east of this project, and measured groundwater levels in our observation wells. We found no indication of movement in the ground landward of the bluff along the beach: in this property, although groundwater in the westerly area was higher than observed in October and early December, and surface water was still draining from the higher ground. In Drill Hole A-1, representing the area considered stable in the report, groundwater had not changed; it was still at a depth of 38 feet. Also, the 1974 near surface slide and debris flow materials (located seaward of drill Hole A-3), were unchanged. In Drill Hole A-3, in the westerly area (the area considered most likely to become unstable), the water table had risen 7.5 since early December and was now 23 feet below the ground surface -- at the bottom of the zone previously involved in movement.. Also, near surface perched groundwater in that area was now standing at ground surface, and in places it was flowing from springs in the ground surface.. That condition was somewhat .more severe than Condition 1; Figure 4; but not as severe as Condition 2. The storm caused great destruction along the bluff slope between. the lower and higher portions of the project, as a result of surface runoff from melting snow and heavy rain. It washed large areas of colluvium from. the slope, and the colluviumcameto rest as debris flows on the lower area near the toe of the bluff. As mentioned in the report, this bluff slope was created sometime in the past when the ocean level was higher and not as a landslide head scarp as suggested by others. It is typical of such oversteepened slopes that have been slowly migrating landward,. but have not yet reached their angle of repose. During this .process they slough and span, and gradually build a blanket of colluvium that helps stabilize the. bluff. When the colluvium is removed, the raw slope again becomes active, and migrates landward by surface weathering until it collects another protective Termination Point Plat Geotechnical Report Page 46 n fl C ~'~ 'i i ii I~ J L ii i~ blanket of colluvium and vegetation. That is a slow process, and since this bluff has been denuded, it will remain active for a long time. At the east end of the project where surface water crosses under Rickey Beach Road in a 12-inch culvert and then discharges out on the .ground, the runoff eroded the toe of the road fill and caused the fill to partially fail. This .water continues across the ground toward the beach, and (along with beach erosion) has .caused a landslide in the low bluff along the .shore.. Near the same area, but on Termination. Point property, erosion. of the bluff undermined the ground supporting a large fir tree. During .our visit there was a high wind warning at the floating bridge, the tide was high, and waves generated by the wind were actively eroding the bluff. It is our opinion that, based on the conditions at the site following this storm, considered by some to be a 100 year storm, that none of the conclusions in the report about stability of the lower area need to be modified, and none of the recommendations need to be deleted. However, some modification may be needed regarding the location of the surface drainage on the higher ground near the .top of the .upper bluff. This drain will have to be located where it will not be undermined by bluff migration. Also, now that the colluvium has been stripped off the bluff slope between the lower and higher ground, more attention must be given to the location of residential construction above the bluff, and some of the existing structures should be reviewed for safety.. Had the recommended surface drainage system been completed in the upper area, there should have been very little destruction of the colluvium on the bluff slope, the road fill would not have been damaged, and erosion along the toe of the bluff at beach level would not continue and threaten the stability of the project. It is ever more apparent now; that. continued bluff erosion eventually will put the entire parcel, including the higher elevations in jeopardy. It should be recognized that conditions are unique at this site. as well as along almost ail the shoreline along Puget Sound. Since the .last glacier receded the .ocean has been higher and lower than now, and wave action developed across wide reaches of water have destroyed large land masses around the Sound, both above and below. the present ocean level, because the shoreline is not rock. Many square miles of land have been eroded away, and this erosion is continuing today.. This is not just of .concern to local property owners who are. allowed to occupy the land as long as their taxes are paid, but should be of concern to all public officials charged. with protecting the ground belonging to the United States. Once this land is eroded away, it cannot be_recovered, so not only is this generation effected by this destruction, but. future generations as well. Most of the slides and debris flows that occurred adjacent to Puget Sound during. the December storm were the indirect result of erosion by wave action, some of which occurred during higher ocean levels. The slides and debris flows occurred because the ground was too steep to be stable when it was subjected to adverse surface runoff and increased groundwater- pressures. This condition can be expected to continue, but can be minimized by careful design in surface and subsurface drainage.. However, since present bluff erosion is continuing, and it is possible to take protective measures to keep this Termination Point Plat Geoteehnical Report Page 47 1 1 1 1 1 1 1 1 i 1 1 1 condition from becoming worse than it is now, such protective measures should be taken. It seems incongruous to engineers charged with the. responsibility for protecting life and property, that public agencies charged with protecting. the environment should actually prevent. everyone from protecting the land they have been intrusted. to protect. Termination Point Plat Geotechnical Report Page 48 Photo No. 1 1~~~97 ~ L~~ The Christmas Holiday stem washed much of the ~olluvium from the bluff, as a result of uncontrolled runoff from move. Photo is Photo No ~ 1~~~9~ b~ same area as Photo No. l~ but farther from bluff. The bluff well continue to slough and span and migrate landward until It collects colluVlum and reaches its angle of repose, Photo No, 4 ~/~/97 b~ LBO Near confer of bluff. Debris clays collected at the base of the bluff. Design of the roadside ditch will protect lower residential area. Photo No, 3 ~~~/97 b~ L~~ East of Photos No. 1 & ~ there remaining colluvu~ has lost support, the bluff mill probably continue to slough, 0 ~, Near past ~r~~. cif duff. c~i~~:iu~.~ i.~1~u~i~~ rug ~~d tree, ~~.~ destroyed. ~1n~istur~e~ aric~il r~u~d i exp~se~. ~~ere ~_i ~ ~'~lo~t0 ~1t~. ~ 1./~/~ f ~y ~~~ ~~.st e~c~ of duff , ~h~to ~~ i ~. ~~~ Ne . ~ Ruof~ fray. ~.~~~~ ~~as i~erease~. beouse of ~.le~r~~ ~etee ~i~d~ view ~ri~e aid tie ~luf f . ~'~is ru~ef f ~.~ to ~~ i~.teroeted ~ ~ p~~~e~ded ~~ !~ .+ same looa.tion as Photo ~o. 7~ but looking easterly. av~e action continued to erode the lower ~lu~~, but those was no evidence of sliding or other story da~.age in this 1974 sli~.e ~~~~. i Looking toward Hood ~an~i and westo~l f~o~ ~~1i Hole A-~. ~~ indications o~ instability w~r~ osr~~~d. This is art o~ ~roa included ~n the 1974 slido. ' RESUME OF LELAND B. JONES EDUCATION ' Washington State University, Civil Engineering B.S. 1988 University of Washington, Civil Engineering Studies, 1942 Massachusetts Institute of Technology, Graduate Course, Soil Mechanics, 1949 ' REGISTRATION Washington, No. 3950 ' Hawaii, No. 4295 PROFESSIONAL ASSOCIATIONS Fellow, American Society of Civil Engineers Member, National Society of Professional Engineers Member, International Society of Soil Mechanics and Foundation Engineering INSTRUCTIONAL ACTIVITIES ' TEACHING Washington State University, 1955 University of Washington, 1975 and 1976 GUEST LECTURER 1 Seattle University, 1973 Washington State University, 1986 and 1987 University of Washington, 1990 ' RECENT GEOTECHNICAL ENGINEERING PROJECTS Geotechnical engineering for current and recent hydroelectric and flood control dams and similar projects ' including geotechnical consultation for engineering design and construction at Colbun, Puenche, Machicura Dams and Colorado Dike in Chile (with foundation cutoff walls to depths of up to 65 meters); consultation for the Corps of Engineers on foundation design and construction for Portugues Dam in ' Puerto Rico (current); consultation to Puget Power for Upper Baker Dam leakage correction and Lower Baker Dams grouting; consultation to the City of Seattle regarding stability of Chester Morse Dam reservoir; review of contractor's claims, Summer Falls and Quincey Chute hydroelectric projects; foundation cutoff design for Snoqualmie Diversion Dam, and design of several other dams for small ' hydroelectric and flood control projects in Washington State. Other recent projects include review of plans and specifications for the Corps of Engineers' Lock and Dam 26 on the Mississippi River; seepage control design during modifications at Chief Joseph and Rock Island Dams; review of design and construction for the Union Pacific Railroad at Bonneville Dam on the Columbia River; review and analysis of penstock failures at the County Pumped Storage Project in Virginia; review and analysis of the embankment failure at Quail Creek Dike, St. George, Utah; and was ' Project Engineer for a two-year design study to determine the Feasibility and estimated cost of extending the Alaska Railroad to Prudhoe Bay. r 0 EARLIER GEOTECHNICAL ENGINEEERING PROJECTS Earlier geotechnical engineering for hydroelectric and flood control dams includes assignments by the Corps of Engineers for quality control inspection and testing during construction of the 420-foot high Mud Mountain Dam near Enumclaw, Washington, and preliminary explorations and laboratory testing to determine the feasibility and preliminary cost estimates for dams such as Chief Joseph, Rocky Reach, and Wells, as well as several dams on the Clark Fork, Flathead and Coeur d'Alene rivers. This was done during studies by the Corps of Engineers for development of the Upper Columbia River for navigation, flood control and power production. During a 13-year assignment to the Walla Walla District, Corps of Engineers, was in responsible charge of all earthwork design in the district. this included design and construction monitoring connected with dams and other flood control projects, building foundations, etc. Principal projects include John Day Dam and Mcnary Damson the Columbia River, Ice Harbor, Lower Monumental, Little Goose and Lower Granite dams on the Snake River, Dworshak Dam on the Clearwater River, Lucky Peak Dam on the Boise River, Ririe Dam near Idaho Falls, Idaho, and Willow Creek Dam in Eastern Oregon. In addition many other dam sites were studied as to their suitability, preliminary design and cost. In addition to earthwork design for the dams, earthwork design and construction were completed for some 400 miles of railroad relocation, some 200 miles of highway relocation, and levies with slurry and other cutoff walls to protect the cities of Pasco, Kennewick, Richland, Washington, and Lewiston, Idaho. The first bentonite slurry cutoff wall in the United States was designed and constructed for levees at Kennewick, and this design became the basis for the present slurry cutoff wall designs. During a TDY assignment to the St. Lawrence Seaway Project designed a 75-ft. deep excavation in Lawrentian Clay for the Grass River Lock, and channel dredging in the river. The Lawrentian clay is extremely sensitive (it is known as a quick clay}, and has little or no strength when disturbed. After the 1964 earthquake in Alaska, was assigned to the Alaska District of the Corps of Engineers in ' charge of the geotechnical engineering work connected with reconstruction of port and harbor facilities, relocation of towns, etc., and other rrnlitary and civilian work. In connection v~nth this work, designed a water supply dam on permafrost for the City of Kotzebue and final design of Snettisham Hydroelectric ' Project near Juneau. The Snettisham Project has a lake tap, a Z-mile long partially lined penstock with 900-foot head connected to the powerhouse at sea level, and rock trap to protect the turbines. u I~ Following the Alaska assignment, was assigned to the Pacific Ocean Division of the Corps of Engineers as Chief, Geology, Soils and Materials Branch, responsible for review and approval of all geotechnical engineering design being performed in the division. This consisted of the design for all military services (Army, Navy and Air Force) by the Honolulu, .Okinawa, and Far East Corps of Engineer Districts, and included Taiwan, Japan, Korea and the Pacific Ocean islands north of the Pluhppine Islands. Civilian work included feasibility studies for 10 dams in Okinawa, safety review of three existing dams, and construction of two earth dams for water supply. One of these dams, Fukuji Dam, is approximately 300 feet high, and discharge from the reservoir is through a tunnel in the left abutment. Other earlier work consisted of a 2-year assignment with the Washington State Highway Department during design and construction of Interstate 5, mapping for the U. S. Geoogical Survey, and design and construction of thirty airfields in Washington, Montana and Alaska. 0 ~i ii 0 u STATEMENT OF QUALIFICATIONS JB SCOTT & ASSOCIATES KEY PERSONNEL James B. Scott, Principal Engineer-Geologist Education: B. S. (1951) Geological Engineer, University of Nevada; PT; Engineer of Geology, University of Nevada Registration: Professional Engineer in Washington State, Oregon and .British Columbia. Certified Engineering Geologist in California and Oregon Summary of Experience: Mr. Scott's professional background embraces the fields of geotechnical engineering, engineering geology, environmental geology, economic geology, groundwater geology, and wetland determinations. Mr. Scott has been the principal of the firm JB Scott & Associates for 20 years, during which time over 450 consulting projects were completed with gross earnings exceeding $400,000.00. He directed engineering and geologic input into siting twenty small hydro facilities for a Northwest utility; made a feasibility study for a series of flood control dams for a Northwest Indian Nation; made reservoir siting studies; was involved in 'joint venture' contracts to study and correct ground water problems, prepared designs for pipe pile foundations and tie-back systems for bluff slope structure sites, and completed foundation investigations for multi-story commercial buildings; conducted structure foundation investigations for bridges, pipelines, buildings; made many slope stability evaluations and analyses; evaluated and designed grouting procedures; conducted refraction seismograph surveys to establish rock lines and to determine excavation character of rock; completed surface and subsurface drainage analysis and design; did erosion analysis and correction design; studied groundwater development and conservation; prepared real estate development feasibility studies; made seismic response evaluations; prepared wetland delineations; consulted with lb Washington State and California engineering and/or geotechnical firms. Mr. Scott has served on government advisory boards and has been called to give expert witness or depositions in five litigations. Earlier work in the fields of geotechnical engineering and engineering geology consisted of participating or directing engineering-geologic input into exploration, design, construction and the operation and maintenance phases of the following: As Division Soils Engineer-Geologist for Oregon. Highway Department was responsible for 900 miles of primary and secondary highways. On the California State Water Projects, first as Chief of the North San Joaquin Design Exploration Unit and then as Chief of the Construction Geology Section of eight hundred miles of canals and pipelines, eight pumping plants, two power plants, ten dams, four tunnels, many bridges, two shallow subsidence areas, and many landslides. While Chief Engineer of Ion Tech, Inc., and Staff Engineering Geologist at Santa Clara Valley Water District, inspected and analyzed several hundred landslides and conducted stability analysis on over twenty earthen fill dams. His work in environmental and groundwater geology includes input into numerous projects and developments in California plus staff review and approval of many EIR's. Conducted wetland evaluations in conjunction with geotechnical investigations in northwest Washington State. Experience in ground water includes general ground water development and conservation. Conducted two major groundwater de- watering investigations related to construction projects plus many single family lot dewatering systems. He also participated in a saltwater intrusion study. Mr. Scott was also associated with a study using ion exchange to treat wastewater. In Hawaii, he developed a program by which water and hydroeletric power could be developed from high elevation sources. Mr. Scott is the author or co-author of six publications, four hundred fifty consulting reports, and about six hundred'in house' reports. He wrote a paper on a concept he developed for the structural control of a major Mexican mineral deposit and based on the concept, discovered a major 'new' deposit. He co-authored a paper on tunnel rock mechanics and was grant~l a gold medal for Outstanding Paper in Rock Mechanics, 1969. Another paper on ion exchange helped advanced that method of modifying engineering properties of clay from a curiosity to a proven technique. ' KEY PROJECT EXPERIENCE 1977 to Present JB Scott & Associates, Anacortes,Washington ' Principal of firm. Responsible for administration and technical supervision of work undertaken as program manager or subcontractor. Scope of work included siting 20 small hydro facilities for a major Northwest electric utility: siting reservoir tanks, siting dams and making reservoir foundation evaluations for Northwest Indian Nation; seismic response estimates, slope stability reconnaissance, evaluations, and stability analysis with PCSTABIA and/or WEDGE analysis computer programs in course of routine geotechnical evaluations; upland and shoreline erosions evaluations and design of correction procedures; established 'tight line' installation standazds; pile foundation design; grouting procedures; designed blasting programs for quarry operations; highway and structure foundation exploration and design; refraction seismic surveys to establish rock lines and excavating character; groundwater development, conservation, and permeability problems; ' clay and waste water treatment using ion exchange; and conducted wetland delineations. In Hawaii, developed groundwater electric power development program in volcanic environment. Appeared as expert witness in legal proceedings. Firm provided services as consultant to other consulting firms. ' 1975 to 1977 Santa Clara Valley Water District, San Jose,California Staff engineering geologist. Acted as 'in house' consultant and supervised contract work of outside consultants. Reviewed and approved EIS's prepazed by outside consultants. Conducted slope stability ' analysis (soil and rock) and designed correction methods. Prepazed a regional inventory (map and text) of geological hazardous azeas for government and private development planning purposes. Made dam site evaluations and stability (earth fill) dam analysis. Approved urban .development plans. Made seismic response estimates and mapped locations of active faults. Assisted in saltwater intrusion study and selected sites for groundwater recharge facilities. 1972 to 1975 California Department of Water Resources, Sacramento, California Chief Engineer: Geologic and engineering evaluations of clay related foundations, slope stability, and permeability problems. Use of ion exchange to correct or improve factor of safety in landslides, ' 1958 to 1972 CIA Minera Asazco: Santa Barbara, Chili., Mexico Mining Geologist. Was responsible for regional mineral evaluations in Central Northern Mexico. Was ' resident geologist at Santa Barbara Unit. Conducted drilling programs, sampling programs, .mapping (surface and underground), mineral evaluation of metallic, nonmetallic, and construction materials deposits. Developed new concept for structural control of Santa Barbara mining district deposits. ' 1952 to 1956 Oregon State Highway Department, Bend, Oregon Soils Engineer-Geologist. As division Soils Engineer, was responsible for geologic and soils input into ' planning, pre-design, construction, and maintenance phases. Supervised division soils lab. drill crew, and inspectors. Made preliminary foundation designs and selected alignments based on geologic factors. Located and drilled water wells for road side parks. Acted as expert witness. Developed structural control ' concept for location of cinder (aggragate) deposits. SPECIAL TRAINING ' 1960-1991: Soil mechanics. U.C. Extension Service; Rock Mechanics, San Jose State; Earthquake Engineering, U. C. Extension Service; Law for Geologist, Haywazd State; Hydrology, U. C. Extension Service; Management, U. C. Extension Service; Jurisdictional Delineation of Wetlands, National Wetlands Science Training Coop. PUBLICATIONS ' "Development Drilling, San Miguel County, Colorado." TEMR 454-5, U. S. Geological Survey, 1952 • "Helicoprion from Elko county, Nevada, "Journal of Paleontology, v. 29, No. 5,1955 Structure of Ore Deposits, Santa Bazbaza, Chili., Mexico, ECONOMIC GEOLOGY. v. 53,1958 • "Influence of Engineering Geology on the Design and Construction of Delta Pumping Plant, California • State Water Project," Geological Society of America (Abstract), 1965 ' • "Chemical Stabilization of Landslides by Ion Exchange," California. Geology, v. 27,1974 ~- r 'y ~• v i P, w / ~ r-- g Tw Z . ` ' 41' 8 3 ~ 44 ~,~ ix ,' PM' tel. S rl~~ ~^~~to ~,~ ~. p ,: O J ee•n. r•t a 4~+ A \~ ~ My w ~ ~ ` u // _ _Zi • t•~o . TW- 3 Z I ~ ~~ r O •0 ~ n ~~ h ,~ •s ?" ® ~° 8 -~ 7 ., ~' ,.~ ~ ,~ 8 ~ - ~ 3, ~ y / O d ,' i k ;o ~ fv ' ati~ o e , ~ e~• : to [ t~v.ti ~• ~ A3 /.~;PfO ,~. ~i rp.~ ' p ' 4~ o~ i O ~ I` ~ e 11 .~! ~ j 8 i 4 . ~ f0 4/8 ~I ~ ~~• .I - ..~ ~ 0 ~~N B6'17 3 .E E'J6.B 1 Note: Plan vlrw map reduced from orl~lnal map prepared by PAC-TECH En~ineerln~,, Inc EXPLANATION Br 197J Ln~_c~NelfMn =Rolan Ihill Ilidc.;l,wah,a,:,~~n+vmaici q P ~ ® L ^ = Pcnclmmctcr I lolcx l lucali~,n ;i~~n+.m,atc) ' ~ - - - -- I r:,cc i I~,caU+,n ;i~~mrima~c~ =Cmss Scchi,n 1995 Im•e.Np~Nnn Tw-3 (~ = wAler wen I>r~n I I„Ic 1996 (.4cottl Inve~N~tion .~ 0 - Ilnckh,r nrnl/.a Xnn,~lc ~qc ~6~J~nce-ScoH1,Invc~NE~Non A~. ® = R„lnn I kdl 16,Ic tiiic ~~ =Cmss ticcU„n'I'rncc A A• ,~.. ~: 1. ~ ~I I see • /s. sz' • /30' • 6•~.s'14 ~~ Se~M 1^ ~ 210' SITF, ~I.^P (~ ~' PC)RTION OF TR:15k PARC:T:L PLAN V1 F,W ~r 51:.('TI()N A-A' Rc 197-199fi Si~T+'ACE ~Nl) Si.rBSLTRFACF, F,~PLOR.1TiON SITE 12/2R/~)~ Figure S-1 TERMINATION POINT JEFFERSON COUNTY, WASHINGTON COMPUTER ANALYSIS OF CONDITION A Analysis of entire reach of Section A-A' with perched water table as it existed as of 10/20/96. No allowance for seismic event or erosion (removal of toe material) from bluff. 1 1 t Using RANDOM (Janbu) method of analysis, the following input data was used: Number of Initiation Points = 10 Number of Surfaces to be generated from each = 10 x Coordinate of leftmost initiation point ...................... 0 x Coordinate of rightmost initiation point .................... 250 x Coordinate of leftmost termination limit ................... 250 x Coordinate of rightmost termination limit ................. 700 Minimum Elevation of Surface Developed is - 50.0 feet Length of Segments Defining Surface is 10 feet. CONDITION BOUTPUT - SF 1.62: Lowest computer generated stability factor surface specified by 8 Coordinate Points. Computer "print out" of 10 surfaces having lowest SF values, with lowest value (SF# 1) shown in red. ~ bL . ~' 450.0 337.5 225.0 112.5 U 112.50 225.00 337.50 450.00 562.50 6'/5.00 /ti/.5U yUU.UU Figure B-2 TERMINATION POINT JEFFERSON COUNTY, WASHINGTON COMPUTER ANALYSIS OF CONDITION B Analysis of entire reach of Section A-A' with perched water table as it existed as of 10/20/96. Allowed for moderate seismic event having acceleration value of H = O.OSg. No allowance for erosion (removal of toe material) from bluff. Using RANDOM (Janbu) method of analysis, the following input data was used: Number of Initiation Points = 10 Number of Surfaces to be generated from each = 10 x Coordinate of leftmost initiation point ...................... 0 x Coordinate of rightmost initiation point .................... 250 x Coordinate of leftmost termination limit ................... 250 x Coordinate of rightmost termination limit ................. 700 Minimum Elevation of Surface Developed is - 50.0 feet Length of Segments Defining Surface is 10 feet. CONDITION BOUTPUT - SF 1.28: Lowest computer generated stability factor surface specified by 8 Coordinate Points. Computer "print out" of 10 surfaces having lowest SF values, with lowest value (SF# 1) shown in red. 562.5 450.0 337.5 225.0 112.5 112.50 225.00 337.50 450.00 562.50 675.00 787.50 900.00 0 0 0 Upper Terrace --~ Ex~stin~ Ground Line 0 Zone 6 Zone 5 SF#2 Groundwater Level 0 Sea Level SF#1 Zone 3 Zone 1 Zone 4 Zone 2 0 Figure B-3 TERMINATION POINT JEFFERSON COUNTY, WASHINGTON COMPUTER ANALYSIS OF CONDITION C Analysis of entire reach of Section A-A' with perched water table at ground surface. No allowance for seismic event or erosion (removal of toe material) from bluff. Using RANDOM (Janbu) method of analysis, the following input data was used: Number of Initiation Points = 10 Number of Surfaces to be generated from each =10 x Coordinate of leftmost initiation point ...................... 0 x Coordinate of rightmost initiation point .................... 250 x Coordinate of leftmost termination limit ................... 250 x Coordinate of rightmost termination limit ................. 700 Minimum Elevation of Surface Developed is - 50.0 feet Length of Segments Defining Surface is 10 feet. CONDITION COUTPUT - SF 1.00: Lowest computer generated stability factor surface specified by 8 Coordinate Points. Computer "print out" of 10 surfaces having lowest SF values, with lowest value (SF#1) shown in red. 562.5 450.0 337.5 Existing Ground Line 225.0 112.5 Upper Terrace ~ / ~,, SF#2 ~. Zone/6 . Zone 5 SF# 1 ~ Groundwater Level Sea Level 0 Zone 3 Zone 4 Zone 2 Zone 1 ~~~ "11~.~U ~~~.UU ~.i/.~U 4~U.UU ~bG.~U bl~.UU ltSi.~U yvU.00 Figure B-4 TERMINATION POINT JEFFERSON COUNTY, WASHINGTON COMPUTER ANALYSIS OF CONDITION D Analysis of entire reach of Section A-A' with perched water table 10 feet lower than what existed as of 10/20/96. No allowance for seismic event or erosion (removal of toe material) from bluff. Using RANDOM (Janbu) method of analysis, the following input data was used: Number of Initiation Points = 10 Number of Surfaces to be generated from each = 10 x Coordinate of leftmost initiation point ...................... 0 x Coordinate of rightmost initiation point .................... 250 x Coordinate of leftmost termination limit ................... 250 x Coordinate of rightmost termination limit ................. 700 Minimum Elevation of Surface Developed is - 50.0 feet Length of Segments Defining Surface is 10 feet. CONDITION DOUTPUT - SF 1.75: Lowest computer generated stability factor surface specified by 8 Coordinate Points. Computer "print out" of 10 surfaces having lowest SF values, with lowest value (SF# 1) shown in red. 562.5^ 450.0 337.5 225.0 112.5 0 0 Existing Ground Line SF#2 ^-~ ~ Upper Terrace 0 (" Zone 6 Zone 5 SF#1 Groundwater Level - 0 Sea Level Zone 3 Zone 1 Zone 4 Zone 2, 0 U 112.50 225.00 337.50 450.00 562.50 675.00 787.50 900.00 Figure B-5 1 1 1 1 1 1 TERMINATION POINT JEFFERSON COUNTY, WASHINGTON COMPUTER ANALYSIS OF CONDITION E Analysis of entire reach of Section A-A' with perched water table 10 feet lower than what existed as of 10/20/96. Allow for moderate seismic event having acceleration value of H = O.OSg. No allowance for erosion (removal of toe material) from bluff. Using RANDOM (Janbu) method of analysis, the following input data was used: Number of Initiation Points = 10 Number of Surfaces to be generated from each = 10 x Coordinate of leftmost initiation point ...................... 0 x Coordinate of rightmost initiation point .................... 250 x Coordinate of leftmost termination limit ................... 250 x Coordinate of rightmost termination limit ................. 700 Minimum Elevation of Surface Developed is - 50.0 feet Length of Segments Deming Surface is 10 feet. CONDITION EOUTPUT - SF 1.41: Lowest computer generated stability factor surface specified by 8 Coordinate Points. Computer "print out" of 10 surfaces having lowest SF values, with lowest value (SF#1) shown in red. 562.5 450.0 337.5 Existing Ground Line Upper Terrace 225.0 112.5 Sea Level Zone 4 Zone 1 11~.~U ~~~.UU ~~/.~U 4~U.UU ~bG.~U b/J. VU ioi.VV ~vv.00 Zone 6 SF#1 SF#2 Zone 5 / Groundwater Level , ~F Zone 3 Zone 2 Figure B-6 t 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 TERMINATION POINT JEFFERSON COUNTY, WASHINGTON COMPUTER ANALYSIS OF CONDITION F Analysis of entire reach of Section A-A' with reconstruction of how ground surface on middle terrace could have looked before failure in 1974. Placed perched water table at ground surface. No allowance for seismic event or erosion (removal of toe material) from bluff. Using RANDOM (Janbu) method of analysis, the following input data was used: Number of Initiation Points = 10 Number of Surfaces to be generated from each = 10 x Coordinate of leftmost initiation point ...................... 0 x Coordinate of rightmost initiation point .................... 250 x Coordinate of leftmost termination limit ................... 250 x Coordinate of rightmost termination limit ................. 700 Minimum Elevation of Surface Developed is - 50.0 feet Length of Segments Defining Surface is 10 feet. CONDITION FOUTPUT - SF 0.66: Lowest computer generated stability factor surface specified by 8 Coordinate Points. Computer "print out" of 10 surfaces having lowest SF values, with lowest value (SF# 1) shown in red. 562.5 450.0 337.5 225.0 112.5 ~ 112.50 225.00 337.50 450.00 562.50 6/~.uu i~i.~u yuu.00 0 0 0 Existing Ground Line Upper Terrace ,~ 0 Zone 6 Sea Level Zone 5 SF#2 Groundwater Level 0 Zone 4 SF#1~ Zone 3 Zone 2 Zone 1 n Figure B-7 i 1 i 1 1 1 1 1 1 1 1 1 1 1 1 1 TERMINATION POINT JEFFERSON COUNTY, WASHINGTON COMPUTER ANALYSIS OF CONDITION Gl Analysis of entire reach of Section A-A' with perched water table at ground surface. No allowance for seismic event or erosion (removal of toe material) from bluff. Using RANDOM (Janbu) method of analysis, the following input data was used: Number of Initiation Points = 10 Number of Surfaces to be generated from each = 10 x Coordinate of leftmost initiation point ...................... 0 x Coordinate of rightmost initiation point .................... 250 x Coordinate of leftmost termination limit ................... 250 x Coordinate of rightmost termination limit ................. 700 Minimum Elevation of Surface Developed is - 50.0 feet Length of Segments Defining Surface is 10 feet. CONDITION Gl OUTPUT - SF 1.00: Lowest computer generated stability factor surface specified by 8 Coordinate Points. Computer "print out" of 10 surfaces having lowest SF values, with lowest value (SF#1) shown in red. 562.5 450.0 337.5 225.0 112.5 0 0 0 Upper Terrace ( Existing Ground Line 0 SF#2 y Zone 6 Sea Level Zone 5 SF#1 Groundwater Level p Zone 4 ~ Zone 3 Zone 2 Zone 1 n 0 112.50 225.00 337.50 450.00 562.50 675.00 787.50 900.00 Figure B-8 TERMINATION POINT JEFFERSON COUNTY, WASHINGTON COMPUTER ANALYSIS OF CONDITION G2 Analysis of entire reach of Section A-A' with perched water table at level that existed on 10/20/96 but allowing for. erosion of bluff to the head scarp of 1974 landslide. No allowance for seismic event. Using RANDOM (Janbu) method of analysis, the following input data was used: Number of Initiation Points = 10 Number of Surfaces to be generated from each = 10 x Coordinate of leftmost initiation point ...................... 0 x Coordinate of rightmost initiation point .................... 250 x Coordinate of leftmost termination limit ................... 250 x Coordinate of rightmost termination limit ................. 700 Minimum Elevation of Surface Developed is - 50.0 feet Length of Segments Defining Surface is 10 feet. CONDITION G2 OUTPUT - SF 0.61: Lowest computer generated stability factor surface specified by 8 Coordinate Points. Computer "print out" of 10 surfaces having lowest SF values, with lowest value (SF# 1) shown in red. 562.50 450.0 337.5 225.0 112.5 Bluff removed by erosion Zone 5 Zone 4 ~ Sea Level - ,. - ~~ 0 112.50 225.00 337.50 450.00 562.50 675.00 787.50 900.00 Upper Terrace ~ Existing Ground Line ~~ SF#2 -~, ,r SF#1 Zone 6 Groundwater Level Zone 3 '' Zone 1 ~ Zone 2 '~ Figure B-9 1 n UNIFIED SOIL CtASSiFICATION SYSTEM MAJOR DIVISIONS ?YPICAL NAMES ~ CLEAN GRAVEL GW :'..Lt .~ WELL GRADED GRAVEL. GRAVEL•SANO MIXTURE ~ G WITH S ' • g RAVEL THAN LES . t ~ 5% FINES GP :=if'~. POORLY GRADED GRAVEL, GRAVEL•SANO MIXTURE _ MORE THAN HALF OF :!•~ . Q ~ COARSE FRACTION ~ Z lS LARGER THAN G M SILTY GRAIVEL. GRAVEL•SANO•SII.T MIXTURE p ~ No. 4 SIEVE SIZE GRAVEL WITH ' Z ~ OVER 12% FINES GC CLAYEY GRAVEL, GRAVEL•SANQCLAY MIXTURE Q ~ OC < Q N CLEAN SAND SW ~ • WELL GRADED SANG. GRAVELLY SAND W ~ SAND WITH LESS THAN ~ • • ~ ~ = Q = MORE THAN HALF OF 5% FINES Sp • . • POORLY GRADED SAND. GRAVELLY SAND O < COARSE FRACTION . . V W 1S SMALLER THAN SM ~ • ~ • SILTY SAND, GRAVEL•SANO-SILT MIXTURE •~ No. a SIEVE SIZE SAND WfTH • ~ OVER 12% FINES SC • • • ' ' • CLAYEY SANG, GRAVEL~SANO~IAY MIXTURE j ML INORGJ+~NIC SILT, ROCK FLOUR, SANDY OR CLAYEY SILT ,,, WITH LOW PLASTICITY " g SILT AND CLAY `" CL INORGANIC CLAY OF LOW TO IAEDIUM PLASTICITY, = GRAVELLY, SANDY, OR SILTY CLAY (LEAN) J UOUID LIMIT LESS THAN SO < i I O ~ y Q ( I ( I 1 ORGANIC CIAY AND ORGANIC SILTY CIAY OF LOW ~ „ PVISTICITY p"' J I I11 Z ~ M H INORGANIC SILT, MICACEOUS 0R DIATOMAGIOUS FINE Q = SANDY OR SILTY SOIL, ELASTIC SILT SILT AND CLAY ~ = Z CH INORGANIC CLAY OF HIGH PLASTICITY, GRAVELLY, < SANDY OR SILTY CLAY 1FAT) ~ _ LIpU10 LIMIT GREATER THAN 50 , „ ~ O H ~ ~ ~ ORGANIC CLAY OF MEDIUM TO HIGH PLASTICITY, ~ ~ ORGANIC SILT HIGHLY ORGANIC SOILS pt PEAT AND OTHER HIGHLY ORGANIC SOILS SOIL CLASSIFICATION CHART Note: Blow count count data (Standard Penetration Test) was taken by dropping a 140 hammer, 3U inches and taking the total count for last 12 inches of the drive. ' Liner sizes were 1.5 inches, unless designated. ' REMARKS: 1 Eig. B-10 a s scoTr ~ t\ssoctA~s DRILLING AND SAMPLING LOG i4 - 3 HOLE N0. . '~'S~1 ELEV. • r FEATURE T~~/~•Q-~d~ ~~6~'t DEPTH S5~ ~ LOCATION - •SGa- ~~' uy`.t„ 2 OY' ~;] u r+t B" 9 COUNTY~~" Sow LOGGED BY ~~ 8. S~ oZ3_~ DATE DRILLED /~,Z'Z`/y~O WATER LEVEL !~ DRILLING CO. ~I'1V/eol7/J9dq.°~~ ~P:'l~ri~RILLER Tom ~cP4.NtS DRILL RIG ~"'G' l . ELEV. (DEPTH) CLASS. DESCRIPTION SAMPLE NOM9ER SPT A~ REMARKS . m,0-'.~O : S/~ C~,s~i,~ 3i,qud S4~r~dit- QA. l4. n~ a'f'-•~ ~ c~( cl~ey ay s 1 t #~ ~'c pis?tinls~.? Saus~. 3aay61•e.. . , • ,' ~ ~o - -r. s~ : coa.~s~ sau.t. a.~.E. ~~, - Shf ,Slot 6y - Pu-~- .... ,os4. ~~~.~, ,~,K. Nn c.tay, t U~Cy~4,r•b.~ + .Uc~t~s-tL~• b~•~ • IN-t G~~ ~ ~ 2 • Saw~,~)bootily So~~v.L~ w.t~ . /n. t~ , • , cot! os. wooet. oN ald tr• ~C/,~,s j lv. r~ lamas o~C G>!ts~rcoo./. So~C~ • Sorxe clays .SawaQ.. lou,sts, ~~ •/Z. S - !3. n CCad a 3cw.e s ,1t~ ' y S . /. /5". o ~ ~ /~, o • . . • " , /? ~•o • ,~ 3~_ ~ ,r2o,n . ,, ~ ~'Z /6 ' • ~~ro - ' 43 ' ~S.d . . ~ . 7 - : 6tu~ S ~4a~c ~~ L ' t ,- Za o • : Sa~s.L C,bsacl,. Set.~,e )..SaN, ~ ion o S , . , e~ 8 tau s ! m.aet~ 4.-x 3 ra,i „,~r2 - Sau~•G f e~a~a~ s;lt; ~~ . - ~' 3 . ad.o ... , 30, o f .f 0 u C u ii n SHEET_ ~'_OF.^ ~' ~-3 ~ ELEV. i(DEPTH) I SAMPLE CLASS. ~ DESCRIPTION NGMSER i s~j' l~f REMARKS l `3p U I ` .. ~ . ~~ -~ 1 i m. d --• ~ ~ ~ ! I I ,35; o Cb v .~ G'mbbl~es a't 35 ~ - ~.- 3S,ca ~ . I - L- 3 -/ + - ~, ~ ~- 9n, d 4n. o . , • S~4 ~s '43.7 - 4 e.n' : fi SSur.a•t 4S, n ct~{yay s~ tt; t+ot~ is SAS 'gS,o l S ~uta,z •~eg ~ W1mlSY'; 3/ 4~.n - 5`?,0' ; F~ssur...t, s~ !~y _ S'~!o ~~ o cCc>u~ -E~ ~Qy s ~ l+c k,o r~~ Sc~.,D o! a~ ae, o~ h y, Gu ~+k ctt~j ~. ~ b ~,c.~,~,o s rn a h~ cp-att,Sre. • P~ef p.+~r~ow, or ti'~.ws is G ~ -f i -I f' ll S/ _ tiy a t-~attc t. - S ?~~ Q. '~-.osd- pot. ta,e.. y-t~'ie ~ { ~ - - $ + ~. f t S~7 tSd - r `- I .ZLCd 7~llZa2. ~t~tab~ ~~ ~, sld,,t~. Tcc.2 -~ bn:~~ , ,~laca~ sc•+••u. Q.t fx~tf+~~+ ~Ce~r, pr e3o, + t i - - a i ; ~ ~ I -~=- C . I $ ~ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ~ s scoTr ~ Assoct~~s DRILLING AND SAMPLING L.OG HOLE NO. A -~ ELEV. ~ ?G ~ FEATURE T~hryli~sai.T/7os1 /~Gris7'~ ~{4.O DEPTH LOCATION ~e~. F'Y_~urt. 2 Oi• ~Jurt ~- 9 COUNTYJt~~tt5on LOGGED BY ~• 8• `S~Tr- DATE DRILLED ~o/~'~ IQr° WATER LEVEL3~..- GRILLING CO. E~+vir0~»,sK~./ ~h'~/is~ DRILLER ~~ ~~4~5 GRILL RIG ~'!Of /vo f~: /~o'e~H~+~+~sr s ~.. ~~~ - ~"O~ Sanrbler . 43a,fu^ le v~ ! 38 ' opt /o~~/9C ELEV. (DEPTH) CLASS. DESCRIPTION SAMPLE NOM3ER sPT ~~ REMARKS oo - ~~o ": F,'t!, a/g/as. ce~at,,.. Saw-bl~- O~t_~•- C~i~y s: t t ; tgr4.u..1.3'~c~o S ti ,= p~s`tt,h b~..e bw..9 ~ by Sr`t-f~ sa.caG art 3.7 ' ba,~arb ~-~• ~ ` S.o hs, Most$y 9Ktuat ~m a~7' S 7.c7 ~ ~ttw, ink ,~Cia•s 's~rtw - ,c b~tack. sa~aQ., C!•scss~,.~ •, ~, • n~nt1,F-e,~ i w. p lcsca~s. ". . . . ~~ . /s /D. D ' • ' • ~. . ~•.. /D.D ,. • '' / .~o _ /4. ~ Tara. ~Ga~, b o /S ' . saw-a2.. Mo~tl~ le,,.pla~:es- ~~ ' . • . C~4,r<wmo@ ona<<1tr woo~Q. a,c~ /~ D . ', « ~ ~ ~IMaS...SCIN! C Gaq/pSt .X.ittwe SY2 • . 6~3 ~Q~1N OZC i'fONs'+~ /¢ltJ~ !.'S . ~ S ' /~• O '~o /9.0~ ~1K ~t~ o 10 • • /4.4- 34.0': Ct•ea+~ fa~+- 'S*~ .Z 3 Sao , . . ' • b~+.a,cJc. satiQ ~c s't bGC >`n , ~ -o ~s ~ y ~ t . • C~,-f- .ZZ.S •f~ 23.S ~s bhscciv. L-/ a~/-~ ~~ . • ~~.(rwobt ~ts.sursdP, /~Po71!•e.~0. S~''~' /~,r" iZS.O ~ ~ . Z~.a P ' . .`.~cc+G 6tc.owlr~s 8 ~ cs 4 - • ~fi+ott~s+, . ' ~'~ z ~ ~~ o • 80.0 l41FFT ~ A~ ~i ' SHEET '2 OF~_ A-~ i r--- I ii C' ii ELEV. (DEPTH) ~ CLASS. ~ DESCRiPTiON SAMPLE NL"1MSER SpT '~~ REMARKS 30, n - ~ __ ~~ 1 - • ', ~ r I • • ' ~ + ~_ . - • as - ~ L . • . • a~,e~ sat ~~•...Q ~ 3~ o $ Kd e[a G rc+ l 61 ' 'f . , ` y, .o .o~ r o h. u e S ~ s of 3 . ~• ~ S~ 4.t a. bout 34.0' ~ t D SiD • ~, 1~ 39:n- ~F°t.Or~ Fine [.-3 o . _ • • b~~ e.. sas, e. c CQy ~. y ,sa,~.aQ, 9or . ' ~ L_4 ~3 I ~ to . o 94 ,~k,S taCl..~ pre 3 v '} i _~ , t .: ~~ ~ ~ ~: ~ ~ -1- I -~- - ;' fi I i .~ - - i ! ! ; {{t i ~ t f ' 4 - t I ! f J B SC07? ~ ASSOCtATFS DRILLING AND SAMPLING LOG HnLE NO. ~ _Z fi ~ ELEV. FEATURE T~hm~i,~,cZ"('~ow Ppl~'t"' DEPTH ~Q'O , LOCATION s'QQ- guy's SL. mr Fc~ure. 4~- 9 COUNTYJ•~~~o~mK V SL.~L/ 'O/~.// /~f • C~ M LOGGED BY ~ DATE DRILLED WATER LEVEL«- DRILLING CO. F.ry~ro~s~-l~.1 Dw'l)~x7 pRILLER om ~a+~S DRILL RIG B"~ 1 ~va,-~ey. /ev,Gj 6.1a ~ ou. ~°l~ I4 6 .I,t„~ ~s~G~C p~~t ELEV. (DEPTH) CLASS. DESCRIPTION SAMPLE NUM9ER Sp'T ~'~`~ REMARKS ' 19.0 - 7.7 ': G~weJ. f+~art. ~7as~..•G a.~.•~ Sa wap /s. Da ~• ' ~GQyQy sq rut ~ sLGearus o''JaN ec ~p ha~P bay S st ~ rltcs7~'sy+ta.l C66a~o~c g~seS) . 5#1 SN =Shelby -P~a~. . ~ ~- Uitok4~'''~'~ ~.••i • 7.7- ?,1.5'; egecea,arss blue- 5aZ 4 •. 9~y 4~e ~. b`~ Q,t /o. o /3. ~ : . ~ ao.~e /o.o .. yCt ~.SvIYrQJ c~.l~st ~ cf!'ha, ' • , ' . FW$s olC woe.2tr cn'tto~cwa~ 5* ~ Aso ~ • ~s.~ ,•, ' Si~F - 1 Leas r ~jlt ~ SJ-~ -1 1 ~' Sa+~,bGa. . ~ Ac.s- ~9 ~ ~: f~shs.. blur -~' ' ' s~~, 9 ~~s ~ ~. ~. ~t ~ 3 . • o,c 14 as o,c ~Ca s 'It e ~ y . y y • /3 • • . ~ • 9~utf ~•susws cui`1~•14. cuoes.Q.. ', ,~ ~Cvo9e,~,.eK~-s, ` L-3 // 24.0 ' . ~Sro To-Ib./ b~b~k. 24.0 ~ ry ~~ C QQ St ,_J a a 0 4 .~ ~0 ;$ ~ .~ ~a . a . ~ a ~w z __:~ .~ w ~ ~~ > _.~ c~ .W ~ e p,,.G j Ir ~1 . ~ M ~ :O z C ~ ~ F '~ ~C ~. O O :~ ~ N . i ~ i ~ 1 ~ { ~ i ~ d i t C it . ._ ~.__ i _ ~~, ~ • Septic -UST's -Roans - . ~ ~ _. -- ...... . ~ -- ~ , _. ~ ADVANCED - c i- ~ - ' _. ., ,~, - S01L - i ~.. ~ _~__..! __I _ MECHANICS { ~ _ __i ! ~ ; -~~- , -~•-- 300 S. 1st St. #C, Mount Vernon, WA 98273 -j ~ , . .._ ._ _- ' , 360-33fr5641 ; _ ,- - r a r i __. . __ . i ~ ~ ! ; ~ _ . ~_ ; ' _ ~ ' ! . .STRESS -STRAIN CURVE ,__ - , . ; ~~' •i PROJECT NAME Tec~nvna}ton por.~~ Job# 299 j ~ ; .:- i . i . -- ~ I ~ - CLIENT NAME 4 ! ~ { i- ' ' I , l i -_~ ~ ~ '• ; ~ i._. ADDRESS \ O u~nC1 r. ., ._ ,. _ 1 { . N i _.., i. I. ~ .r M i ' - I .- 1_ - ~ re ~ ~~ s PRONE d r p ' K~pS ! ;,_, .,,,._f r r { ~- ___J __~ _.,~ ~; 3:5`CO P5~ ~__. SAMPLE DATA:. ~ ~ ~, a 4 ;_ SAMPLE DEPTH S ~ i t i ~~ ; ~ . ~ ; REMOLDED OR INTACT i Ai~'ACT .. 1 , • M ~ ~ - I ~ j I - - ~ } _ - ~ ! k .. AVERAGE STRAIlV RATE . 0 0 - 7 IIv. ~ ~ i _..._ { -;.. . ~ A VE TRAIN ~a FALURE ~k . Q i ,_ ,.. , ,_:- _..~ ,_. 1. ,.. ~-G . ` ~ , . , ' ~ r i ~ i I . t ~~ • l r _. _ ..... ~ ys ~ 1 {. • N ~ ~ r ;~ .. _. __ ..._~ _. y;P , ~ _~ __.. _ _~ _..i :j ~ Via, 63 ~ 4 ~. pO ' ~ r i ~ • i ~ 1 ~ ~ r 1 F i ~, i i ' ~ t ~ j , ' r • r r ... V i I i ~ . .-. .- _ .. .. ..' ...... t ~ ,.. ... _ .• r ~' ~ .+ i._ ` ~ }_ ~~ . _ . { ._~ _ ~ . i ~ ~ _ _ .L~~ KIPS , - '-- - : , ~,~ - ; • 3 ~ ~_ . . • - -~ P .. ~ _~ ~ i i ~ ~ i .. ~ ~ • . , ~ ~ , __1.__.~ t ~ _ __. . _ .._ i I ~ r ! ~ , '' ~ T i ~ - ~ , --; ~ i 1 ~ ; _~ . , __ ._... i . _ ..__~._. _ __. ~._~. : _ ' ( _ ~ i • , i ~ ~ ~ ~ _ _ ~ _ - __l_.__ ! ff ~__w . ~ ., ~~ ~ ~ _. _ _ -.. i .,, ~ ~ ...025'! ,- t •050" _ A75" _.{ ..100" ....125" ~.,~ ,150'! , , .175". 300'•.. .225" ~ .250" _ Z75" 3 !' ~ ... __. _ • r __ ~ ~ ~ { ~ i STRAIN IN INCHES (EA. SQ. = 0.01") ~ ~ . ' . .. ~ _ _. __ ~ ~~! .. !! _.. i.~ i TM D 3080 -.DIRECT SHEAR TEST i ... ; - + . J ~- - ~ -~ STRESS - STRAIlY CURVE - _ ; . ~~ _.... i... ~ ..;.. .::J .; ..( :.~_ ~.a i Zvi ~voil-yam YJ1KL+'(;'1' ~Jl-iLAK `$ ~..~. .~ . ~ ~..~,rfLSi~",~ SOIL Project name Client name Client address Sample number ~3c~td~~. .. Location sampled [Soc, n ~ •#~ 3 Sample depth Ig ' ~ x.1.5 ' Sample description OQrk o1~~,.Q, q ~-~,~~,~~ ~ ~L ~ m~,.,~, C.H~ ve.~y So St ~ ~ s~t~.~ rc.~e.d~~ SOIL SAMPLE MEASUREMENTS: .Shear sample no. ~ Sample water content from cuttings: diameter 6363c~ -~ NORMAL Load in KIPS 1 • ~~` , Fal F ~ KIPS;.-Tare number/wt. 'i ? ~-$. b xms - height 2.00 cm KG of weight applied ~,Q_,kg Tare + moist soil 14 4 . l volume 63.60- cc Tare + dry soil 1 1 6 .'~ moist wt. 13~ . a gms "/o Moisture from cuttings ZS : 1 "/o Wt. of water Z.~i . 3 moist unit wt. 1. I ~1 ~/cc ~ "/4 water content 2 S . ~ Dry unit wt. 1_ pcf Initial vertical dial reading 0.0000 in. Moist unit wt. Imo' ,~,~pcf Consolidated dial reading . 0 41 o in. Change in height ' 0`I Z Z In. . - 'Vertical dial @ failure .D'i 1 in. Sample ht. ~ failure •1 ti S 2 in. . ~~L-tc~i = .O~y 22.'' EIAPSEO TIME IN ~Iti EN[All. OIAI. W ~ =HEAR OIYPLACCYENT IN M. PROYIN{ .RING OIAI. IN .0001 M. SNCAR IORCE IN 1-b SHEAR ~TR[S;,'>;~ iN I-•.~a~. It .ozs.. .oso~~ ~:o~s~~ . o.ioo~~ 1 t 2 3 ~ j 32.9 1 y y S. b 9 y 11 2 ~ 9 317 o.tz~', . 15 y$.9 l3y 3 o.><so~~ 53 ~ 5.0 1 ~ 1 ~ o.><~s° 1 3 '-l5. iJy 31.'1 o.zoo^ 15 y S. 0~1 1 "S 1 o.zzs~~ o.zso~~ 0300~~ . ADVANCED SOIL MECHANICS 300 S. 1ST ST. #C, MOUNT VERNON, WA. 98273. T~ ~ F = e • ~ ~~ X360) 336-5641 ~ Tv.~~ Sa, s,,.c = 132.9 TarC+ 0~y ~~1 = ~~V.~ r O Ka i in ~vtsu-y~, lJ1KL~'(.:'1' ,HLAK '~~,~ ~> _:: _ 4 . ..~xESl~~;u SAIL • " Project name `Te~ti,~~~.~t~„ Po~,n} ' Client name RvSS~{ Tr-cfK Client address _.1355, d Svn~~~e. Dr , ii C C r 1 i n ElAP3E0 TIYC IN ~k ENtAE p1AL W ~ =NtAA OIIiPIACGYENT IN M. PROVINp .RING OIA~ W .0001 M. SNLAN iORCE IN Ida 3NEAl1 3TItLi;, 'E, IN Ib.~s~. It 3 ~'~ i~ z ~.oso~~ ._ ;,o~s~~. - . o><so" ~.z1 Z G3 3 o I . l,S. plo 7 3 '~l ~i~ 6 Iq b1. a. S t o.i7s~~ - 303 ~9 .20 - 6 0 • o.~oo~~ o.z~s~~ o.iso~~.: ~~o ro ~ 6 3' 9 0 .0 9 9 ~ 3 y 34 ~ S ..oz~$„ • • 0300~~ Sample number ` ~ , Location sampled o c r 'N . .' Sample depth 19 - ~1: 5" tt Sample description o"~ s i 1 ct CL wl~~ a cry.-}cal •wc~. W~r+,~d ~f {~y sa.Rd Sa~vra .-} C~ ~ ,very 5~~~ ~duc~ ~w~ ~~~~.~~ SOIL SAMPLE MEASU~ EMENTS: ~ _ Shear sample no. ~, _ ~Sample~vater content from cuttings: ~• ~ W` j diameter ~ 6363cm ,, .,NORMAL Load is KIPS 3 , s ~ R KIPS Tare number/wt ~~ _G, a.l tams height 2.00 ' cm = •-16'1 y KG of weight applied ~1~kg Tare + moist soil ' 23 G . ~ volume 63.60 cc moist wt. I O . gms . % Moisture from cuttings % - Tare + dry soil f $5. 1 Wt. of water 51 , 5 moist unit wt. ~ , 0 4~a/ca Dry unit wt. 9 ~9 pcf Initial vertical dial reading OT in. % water content ~.°I , 10 Moist unit wt. t 2Z . $ ncf ~ _ Consolidated'dial reading ~ 03 q 4 ip, ~ Change in height. - o ~ oS y tut. .. , . "Vertical dial (ul failure .os' Z'3 in. Sample ht. (u; failure 13 3 2 in. • N ~ ~~~ .p54Z1,,. ~0,1 # 1- t wig _ t28,5 +a ce. T.'1 a~3 ~ 5- 0 i f' 0 L'~ ii C C ASTM 3080-92 DIRECT SHEAR TES ~ w~ ~;t)HESI`I~E SOIL Project name "~'er+M~nG.~~~Sk; Pd~,.4 Client name- RvSS~I `T'rrs~ Client address ~3SSo Sv~t;r~5t IS r• . ljo.~4.~hr~l\oa•. ~~~ a. , Sample number _ ~ , S ,1 ., Location sampled o ~'n n1 Sample depth t9 - ?.1;~ t t Sample description o ' Q.. r i 1~ cl CL e. C ~ wl~~ o. c~•-~co.l ~wc~. w,n,Yd u~ 1}y San1~ Sa~vtiw,+~,v~cy 5~~~ l1ucJ iM~ ~~~~-~~. SOIL SAMPLE MEASUIZEMIENTS: Shear sample no. 3` . ;Sample water content from cuttings: ~• r ri` diameter : 6363 cm .: ~ NORMAL Load in KIPS S • 8 0 2 KIPS Tare number/wt~ ~S 51, 0 ums height - 2A0 cm (:16 l 4 "~ KG of weight applied qt1 kg Tare + moist soil ~ d4s. 3 volume 63.60 cc ~ ~ Tare + dry soil 8 1. $ moist. wt. 12ti . I_S gms~ ~ % Maisture from cuttings 3 S . 9 1 % Wt..of water _ ~6 moist unit wt. I ,9SZ ttkc - % water content 3 5 , 9 1 Dry unit wt. 89, ~,3pcf Initial vertical dia~1 reading' 0.0000 in. . Moist unit wt. ~ t L 1. 1 cf ~ ~ Consolidated dial reading ~ ~ `I y in. Change in height ~ hS ~ m. .. ~. .. - Vertical dial (~ failure Din. Sample ht. (a~ failure •"l 3 4 9 in. ,0333.®e~ . " E~AYSEO TIME IM tlti iNEAIt Ou-1, W ~ iHEAII -~ 01YPLACEYENT IN M. -AOYIN{-QINO OIA~ NI ,0001 W jMLAII IORCE iN D~, iNEAR {~ettj, Z, ul i-s. q. It ._ .,.- _ .025° Z. .; '~ ~{ 'z ~ ~.oso~~ 95s • ~ ~ 4 ~.o~s~~ 114 . ~~ ~ 33 57 ~ oaoo~~ ~ ~ 1 ~.~. 6 3 S5b o.>i2;;~,. ~„ '16 359 0 .~o.ISO^ ( 6 35'tO • ~o.iZS~~ ~ 1 ~.7,. ~I~ .. 0.200^ y I t 20.70 3529 o.z2s~~ o.2so-~. • •..o..:z~~~i~ .. .. ., _ ... ._ `~ r ~ Y ~: ~ f~W.f Lai\ Vi/i/ SO~ 1\ii/h/J.i~fi~iVS - 300 S 1ST ST4 #C' MOUNT VERNON ~ WA. 98273 . ' ~ 3 , , 360 -5641 ( ).33 }~ M I I vi f ~~a '• ', •I IY1 , . ~~. a.. a ...NI.. , mow. A-3. s - t O U.S. Standard s+~w~ Nu++bKS Itraroe-~tK GRAIN SIZE t!{ MtL~IMETERS CODES v+~avEt` ~aN~ COARSE FINE C04RSE MEOIUM FINE SILT OR CLAY DEPTH PIT NUMBER OR SAMPLE LO. _3 S_~ CLIENT NAME _ ADDRESS - UST's -Roads. - Lab P H D N E 'ADVANCED DATE SAMPLED D ATE TESTED ~O ' L CHECKED BY /IECHANICS PARTICLE SfZE ANAIYSiS 1392 M clean Road, Mount Vernon 424-0291 SIE~IE ANALYSIS., C 1.36-8,a ASTM C 136-84 - SIEVE ANALYSIS OF FINE AND COARSE AGGREGATES PROJECT NAME CLIENT NAME ' ADDRESS PHONE SAMPLED BY/DATE CORPS OF ENGINEERS WORK ORDER # SAMPLE DATA: SAMPLE NAME/LD. AND DEPTH - . S - ~ ~ NET DRY WT. TOTAL FOR TEST ~ 3 q ~~~~ `~ GRAMS i NET DRY W'T. FOR HYDRO AND FINE SIEVE S q , p GRAMS OF SAMPLE -# 10 SIEVE L~.h ' ['nARCF. SiF.VF:C FiNF. CiF.VF.C SIEVE SIZE WT. RETAINED %PASS WT. RETAINED Ye PASS ~MBINE Yo PASS SIEVE SIZE 3,. 3" 2.. 2.. 1 1/2" 1 1/2" 1~~ 1., . 314" 3/4" 1/2" 1/2.. 3/8" 3/8" #4 #4 #10 #10 #16 ~9, ~ #16 #30 e ~ ~ ~, ~, #30 #so y, ~' 9~,,y #so #100 ' '~, ~(~,`~ #100 #ZOO ~ °~~ .3 ~o.~ #ioo PAN- ADVANCED SOIL MECHANICS/I39Z MC'LEANRD/MT. VERNON, WA. 98273 C~ ~ ~ ~ T~„ G ASTM 422-90 -PARTICLE SIZE ANALYSIS OF SOILS HYDROMETER ANALYSIS/152H HYDROMETER PROJECT NAME CLIENT NAME ADDRESS PHONE CORPS OF ENGINEERS WORK ORDER NO. SAMPLE NUMBEIt/DEPTH (FT) -A- ~ 5 _ 1 (a1 19~- x.1.5 ~ DESCRIPTION: GRAVELLY, SANDY, SILTY, CLAY (CIRCLE ONE) SPECIFIC GRAVITY Z, 4 5 G/CC ASSUME C LCULATED~(CIRCL~ ONE) NET DRY WT. FOR HYDRO AND FINE SIEVE ~ ~~ , b GRAMS OF SAMPLE - # 10 SIEVE I 0 h SU~I~'IlvIARY OF READINGS: DATE/TIME READINGS BEGAN (I ~~ 3 ~1 ~ ~~J ELAPSED TllNE READING TEIvIP. CORR. CO • DEG. G FACTOR RE 1 MIN. S j. ~? - ~~ y. c 3 MINS. ~Z • 3 10 MiNS. 6o Mnvs. 2 ~' ~ 7 _ ~ ~ g 120 MINS. 2 Z 1? -~ ~ s R. D. `Ya FINER DIA. ~~ . ~ 3°-~S 5~,3~ ~ U~SI ~9 .~ ~ v l y~ 30 .S ~ U~ y _ ~.~.y R A S ~ v ~ y~ ADVANCED SOIL MECHANICS/ 139.2 MCI.EAN RD./MT VERNON, WA 98273 , (360) 424-029 - , " H~} t et r~ -T ~ G Q ,, 1S 't h. 1 i n Cut ~ • 1 1 1 1 1 1 1 1 1 1 1 1 1 1 to ,.. 4 „ 0 10 ASTM 4318-92 LIQUID AND PLASTIC LIMITS OF FINE-GRAINED SOILS PLASTICITY INDEX OF SOILS .SAMPLE PLASTIC NO. LIMIT a-3, s-1. - -~ 9 30 40 50 '60 70 80 LIQUID LIMIT LIQUID PLASTICITY UNIFIED SOIL CLASSIFICATION -tine LIMIT INDEX grained soils 2~ 'l ML- GL. Project Name ~ ., w,,,.,.~~ar~ ~b~n`~ Client Name _ 'R ~ ~ S.c, ~ T~-r,.~ K Sampled by/Date 'S. S ~,,-1~{ P E Date Samples Arr/Date Te ed~ ice, ~ q CORE OF ENGINEERS WOgg ORDER NO. ~ zq q ADVANCED SOIL MECHANICS/ 1392 MCLEAN ROAD/MT. VERNON, WA. 98273 . 1360) 424-029 i .' ~~ I i ' ATTERBERG LI"IIT DETI:RML;tATIOiIS ~iv~ t=- Z ~r ~ (P`grforme~-Qn Soii Fraction Pa3sing No. 40 Sieve) ?flOJECT NA:IH: iQ. rn~n 1~ Ystn't 511,~I8LE .10. i ~- ~ - 1 CLIENT NAHEs ~ uSS.c. Trfil DEPT:L (ia.~: ~-'~"~"-'- ' A?NO: DATE OP TESTS ~ Q SAMPLE N0. LIQUID LIMIT PLASTIC LIMIT CONTAINER N0. - (~ ' "t N0. OF BLOWS 3 I ~ •~T. CONT. + WET SAMP 22. 24.0 :JT. CONT. + 0 Y SAMP 15.2 i .yi- ~ .2 WT. OF WATER 3. X1,.3 WT. OF CONTAINER WT. OF ORY SOIL 12. 5.8 i , MATER CONTENT Z Z.S.Iy 2-i.'Z ~8 ~ (p 8 b.~ 3 .~ 1. SAMPt.C N0, LI UIO LIMIT PLASTIC LIMIT .r0. OF BLOWS .~T. CONT. + WET SAMPLE WT. CONT. + ORY SAMPLE '.IT. OF WATER :1T. OF CONTAINER WT. OF DRY SOIL ATER CONTENT X ' 2.5 SUMMARY i SAMPLE NO...~ 3~, S-~ G~ (q5-~,~~ F Z f~ F Z o U z m F 4 z7 x.47 a 9 Io 1 iS 20 ~: 30 NUh IBER O~ a ~14c ~a . ~~~ LIQUID LIMIT ZS.~ PLASTIC LIMIT 1 g ~~ PLASTICITY INDEX "~~'~ 40 SAMPLE N0. LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX Septic • UST's -Roads -Lab ~~ ADVANCED SOIL ~, MECHANICS 1392 Mclean Rood, MountVernon. WA 98273. 3~i0-424-0291 ~U - 1 1 1 ii C UNCONFINED COMPRESSION , ~.~> ~- ~,~, N 21 m e ~ t+RVf~A ICvA Nooc~ ~a,~ ~ tJC tc~ Q ,_ Date - i 1 ~l 3 ~ `~ 6 Job N o . _ 2.9 q nn ..~ ~ ~ - BorinE No. _ Ne , ~ IW E1,5 - 59 Sample No., [)ascription of Sample ~'~ 51 _, t ' S~ Depth/Elev.S~•S~~ S`i s) E} ~ ~x~'re, rn ~l ~~ Proving Rini; No. 2~~`t3 ~ ~~ ~o " Apparatus No. '~ Water Concenc Determination ~ Tare No. ~ ~ 6CT~ Wt. Specimen Wet -I- Tare Zo~iQ_gms, ~ Wt. Specimen Dry ~-.Tare ~g2•~ - gms. ,. Wt. IYater ~b'y gms. Water Content in ~ Dry Wt. ~~~"°`~k• Wt. Tare- 7. gms. at 105°C 3y;~_q, Wt. Specimen Wet ~.~5-,~_gms, Unit Weight Wet ,.~~'_ ~I~J.~ gm/cc Wc. Specimen Dry l~y•~ gms. Unit Weight. Dry Q4• gm/cc 235.1 t~y.1 l;nc:onfined Compressive Strength -g' kC2.4 1[ >162~y ; 3, 12'I-s-I6~ Initial Diameter Do; ~~ ~ cm Final Diameter De 3,5 ~ cm Ini vial Area Ao _ ~~ • yb(o cm2 Final Area. Ae ~~•b~ • cm2 Initial Height `tlo ~ I~..Z~~ cm Final Height He II.S~ cm Initial Volume Vo I~~.57g cm3 Final Volume ye ~ LS.O cm3 x.2?5= Test Data ~4 ~ 2.54 = .20't2 Corr. Area . ., AO t'1 1! n Nn ELA-SEO TIME•MIN. LOAD DIAL IN 0.0001•• AXIAL LoAO P KG STRAIN DIAL IN .001" TOTAL STRAIN INCHES UNIT STRAIN CORRECTED 2 AREA•CM a - •• STRESS 2 KG/Cw a r y Y• O1 .. L~ 5 r 25 , oa 5 (o ' ~S O ~~ . o~S ~-~ .loo ~ ,125 1ti7 t150 tS~ . t~s 1 ~ 200 1 b .Z2S 1 Z . 25 p ~ ~ .o .Z~s o.~-~s •05'~ tt.o3 6,go~t 139 7 1+ ~'~ o 0 or ; ' Failure Condition~~ '~~-5 ~0~1 TS~ Remarks .. ADVANCED SOIL MECHANICS 300 S. 1st ST. # C • Mount Vernon, WA 98273 • (360) 336-5641 /FAX (360) 336-5641 0 i CI ~l n 'J U.S. Stonda~d S+~w iJur++bKS Nyd-ow-~t~~ - too ~ a 2 i~jt t 3/4 Irt3/e 4 e to Is zo zo 4o so eo bo too zTO f0 eo TO eo °° ao a: 40 W ~w L Zo 10 (~ loo ao to s Q os o.l o.oa ao{ o.ooa o. (iRA1N SIZE JN iMLLIMETERS CA~Lt` GRAVEL ANQ S C.OARS FINE COARSE MEDIUM FINE SILT OR CLAY DEPTH PIT NUMBER OR SAMPLE LD. _~ _ CLIENT NAME - ~.Q. Sc_o-~"" ADDRESS Septic -UST's -Roads -Lab ADVANCED SUS ~ _ P H O N E DATE SAMPLED DATE TESTED CHECKED BY MECHANICS 1392 Mclean Road, Mount Vernon 424-0291 PARTICLE SIZE ANALYSIS S j E it E A N A l Y S I S, C 1 3 6- 8, a __ U.S. Stondard Si~w• ~1~~~ itydroe-~ht -D ' ' r ~- m oc w DEPTH PIT NUMBER OR .SAMPLE LD L ~~~ CLIENT NAME; - ~Q. 'Scc>~(" ADDRESS' , -UST's-Roads-Lab ~DVANCEU ~O' ~ - ~...' PHONE GATE SAMPLED . `~ DATE. TESTED CHECKED BY ' MECHANICS ~ ~ ~ 1392 Mclean Road, Mount Vernon •_ 424-0291 ~~~ .. - , ' ~~PARTICLE SIZE ANALYSIS .. S I E y E 'A N A L Y. 5, C 13 6- 8~ a RAVEL ANO T OR CLAY ~SIi C0881'ES COARSE FINE FtHE COARSE MEDIUM . ASTM C 136-84 - SIEVE ANALYSIS OF FINE AND COARSE ~- AGGREGATES PROJECT NAME ~rnn.~~,~.,,, Q},,Lf~oo~d C~~~••_~ Q~«1~~ CLIENT NAME _~e.~e.,Ml \o ~ ~ / .S 6 4~ a ADDRESS PHONE SAMPLED BY/DATE ' CORPS OF ENGINEERS WORK ORDER # SAMPLE DATA: SAMPLE NAMElLD. AND DEPTH NET DRY WT. TOTAL FOR TEST g ~ ,t~ G~ NET DRY WT, FOR HYDRO AND FINE SIEVE A3.4 " GRAMS OF SAMPLE -# 10 SIEVE 1 pC1 ~ " MARCF CiTi Vi~'C L+rwt~ ers«a ~~ SIZE WT. .RETAINED Ye PASS WT: RETAIldED K PASS COMBII~IE Yo PASS SIEVE SIZE 3" ~ 3p 2" 2~~ 1 1/2" 1.1/2" 1" 1" 314" 3l4" 1/2" 1!2" 3/8" 3/8.. #4 ~ #10 #10 #16 0 IOC ~ r e t #16 } #30 Q 10 d ~ t.,, C~ #30 #50 •. q. g #50 ~~:. #100 . ~~,(~; .~ `#100 #200 ~. 3Ss~ Sy, ' , i Y #200 PAN Tin t 0 . C.'vr1 L, ASTM 422-90 -PARTICLE -SIZE ANALYSIS OF SOILS HYDROMETER ANALYSIS/152H HYDROMETER PROJECT NAME. CLIENTNAME ADDRESS PHONE CORPS OF ENGINEERS WORK ORDER NO. SAMPLE NUMBER/DEPTH (FT) _ ~ I - L y DESCRIPTION: GRAVELLY, SANDY, SILTY, CLAY (CIRCLE ONE) SPECIFIC GRAVITY S G/CC ASSUMED CALCULATED (CIRCL$ ONE) NET DRY WT. FOR HYDRO. AND FINE SIE 3. , GRAMS OF SAMPLE - # 10 SIEVE ~ (7 (' SUm~1MARY OF READINGS: DAT'E'lf IME READINGS BEGAN 1 ~1 ~ 3 /g b 11;19 ~pi~~ ELAPSED TIME READING TEMP. CORR. CORR. DEG. irC FACTOR READ. 1 MIN. z~ ~ 1'1 ". x ~ 2, ~ 3 MINS. 2 S . _ ~ 10 MINS. Z ~ I y 6o Ivm~rs. -7 _ 1 ~ iao MINS. t S -~ $- 96 FINER DIA. ~) --3y:~ , OyS? I6• ~~ .016 f2.0 . 0vb7 ADVANCED SOIL MECHANICS/ 1392 MCLEAN RD./MT VERNON, WA 98273 (360) 424-029 I T'in 1C~ . ~ ~' . ~ ~--~ ~ ASTM 422-90 -PARTICLE. SIZE ANALYSIS OF SOILS HYDROMETER ANALYSIS/152H HYDROMETER PROJECT NAME CLIENT NAME ` ADDRESS PHONE CORPS OF ENGINEERS WORK ORDER NO. SAMPLE NUMBER/DEPTH (FT) A f - („ ~ DESCRIPTION: GRAVELLY, SANDY, SILTY, CLAY (CIlZCLE ONE) SPECIFIC GRAVITY 'a,. SOS G/CC ASSUMED ALC ULATED (CIRCL$ ONE) NET DRY WT. FOR HYDRO AND FINE SIEVE 121 , S GRAMS OF SAMPLE - # 10 SIEVE ~ p y SUm~IMARY OF READINGS: DATE/TIME READINGS BEGAN ~!S /96 11 ~ Iii 30 (~1^V~PM)J ELAPSED TIME READING TEMP. CORR. CORR. DEG. i~ L NACTOR RE D 4/o FiNER DlA. . A . ~~ 1 MIN. 3.2. 17 - ~ ; S ' ~C,~ . °6~ , Oy ~. 3 MINS. Z~ - 2d . ~' ~ t7 a,~ Z t o MINS. Z~ I y _ I (. S , U 15 4S 60 MINS. ~ ~ - 7 I ~ • ~. . d U (o ADVANCED SOIL MECHANICS/ 1392 MCLEAN RD./MT VERNON, WA 98273 (360) 424-0291 i Ti v K.. . ~ ~~ N_ 1 1 1 1 1 1 ASTM C 136-84 - SIEVE ANALYSIS OF FINE. AND COARSE AGGREGATES PROJECT NAME Tec~dv.~v~a~i~ Yo~v.~C' ~. Noocl~ ~,n~` ~$+r ~ aI ~ CLIENT NAME s , ADDRESS ~O. t tJU ~ S S /'• PHONE SAMPLED BY/DATE CORPS OF ENGINEERS WORK ORDER # SAMPLE DATA: SAMPLE NAME/LD. AND DEPTH /`-1 ~' ~- ~ NET DRY WT. TOTAL FOR TEST ~ 12 ~ . ~ -GRAMS we.~ ~..i~ NET DRY WT. FOR HYDRO AND FINE SIEVE I Z t , S GRAMS ~~ l ' `~ OF SAMPLE -#10 SIEVE 10 0 COARSE SIEVES FINE SIEVES .~ ADVANCED SOIL MECIiANIC.S/1392 MCLEANRD./M . VERNON, WA. 98273 T~h 1~ ~~ ~.n l~ SIEVE SIZE VP!'. RETAINED °/. PASS VAR'. RETAIIJED % PASS COMBINE °Yo PASS SIEVE SIZE 3" 3u 2" 2~~ 1 1/2" 1 1/2" 1" 1" 3/4" 3/4.. 1/2" 1/2" 3/8" 3/8" #4 ~} #10 #10 #16 . (0 95,5 #16 #30 ~. ~ ~ 9 . y #30 #SO I ~, O g0 • #50 #loo , 63. ~~~, #loo #aoo g0.7 -. 2~.3 ~ #200 .PAN i~ N \~ Q 3 CO O-I ~ r- ~. ~W,J V >°; r V. Z ~4,~ Z ¢ov- >O = ~v ~V-~ ~$"''c c : O a U i i M ~ I I ~' c~ W ~i 2' ~I i- 2 f- 2 W O ' W F- ' N O 1 a v ~c t V H' ~~ ~ ~ ~\ ~~ Q d' O Z p- c m ~... `, ~Gr. ~~ ~ l; J . (~ 4 J c~ ~-- 1.~„ ' ~ c~ ° ~ = r' -~- t!~ ~ cr1 O ~ 6- M ~ ~• ~ ~~ a - ~ r -- _ 'c.,,-~ ~,: ~ r. ~n ~ r .~., -r m ~ . . o ~-- ~ + + ,~ ` E ~ ,,,,... c ~ `..~ o E v E ~ E , c ~ ~ N c M c N , t o~ s v~ 2 ~ o v a ` ~ ~ ~ ~ 3 a t -- o to N 3 ~ N ~ ~ u " E v t v- E o i 3 _ 3 3 3 3 a ro ~, a` i ~ > % ~ ~ -_ _ N P , 3 ~ ~ ~ V ~ ^. V Z ~Q, r Z ' O ¢ = o ~ j ~ V ~ a$: c ~ Q C ~~~ ~ v L c 0 C 1~ a~ U i 1 i v I 1 1 1 1 1 1 1 ~ 7 aD F- z z O U '~ W ,~ N a ~~ r ~. . ca s ~~ a a 0 Z a ~i m '~ ~~ • v o~ 'A~ (~ 'S J to 3 J `g ~-i - ~~~ coo ~-- L.r? ~' ,~ X Q.. s N r ` wf1 r r C~ ~~~QJ ~~ r ~ r,,j O t~ ~,. O T d) S is ~ .9 ~ ~9 9 ~ N I" Q- l n S c~ T ~ 1.T d .. -. ..~ O _t `~ ~ r ~ v 1~ to ~ r ~ s m ~ 11) +n ~,: r r- ~ ~ ~t ~ .r ` ~ ,~ a-- ~' ~ ~- ~ cn J fi `9 ~,- O = - ~ s ~ o Fes- ~ o f.. /'~ ~. N co 07 v ~ ~ E - + 0 0 .~ E o c M N .- .. E r a ~ o N N 3 ~ N ~ E ~ a ~ c ~ ~°n o t°- 3 3 3 3 3 a c a` s >° F°- . ~ ~ ~- - ~n~ulvr 1IYCU l.Ui`"IYKtJJ1UfV I tJ I - UU1 { Name i r v'Y-~ r~e,.'~jt~'h P6 ~h1' Date Il / y / ~~ Job No. Lor.ation _ Boring No. A-~ ~, -~ Sample No.. A3 - ~ y Depth/Elev. Describt`o\\n of Sample ~ti1vC. ~, rv.:y. L~t~l_~u-, ~~, ~}' ~SI~~ - VC.,~~tC~Tr ti4, Sa~.~~ _ t , ~t'~'1.Q ~ ' Proving Rinq No. ~1-i 9 3 -U1-~~0 ~~r `~~ to Apparatus No. ti Water Content D terminatipn Tare No..~ ~ ~ ~~ Wt. Specimen N'et -}-'fare 23~ ; S gms. Wt. Specimen Dry -{-.Tare 115 gms. Wt. 1Yater ~1.2 gms, Wt. Tare 1.~ gms. ' Wt. Specimen Wet 2~ 8 ,''l gms, Wt. Specimen Dry 16 1.5 gms, ' ''n confined Compressive initial Diamcter ' Initial Area Initial Height Initial Volume ' Test Data 1 0 ii 0 Failure Conditions ' Remarks ADVANCED SOIL MECHA~ ~ ~~ S ' ~ 300 S. 1st ST. # C • Mount Vemon WA 982 336-5641 F 360 ::.. " 73 (360) / AX ( ) : ~ X641 1.~ ~( f ~~: .Water Content in ~ Dry Wt'. ,,jZZe.?~,x62• at 105°C Jlo •5~ ~ c ~i21.2. 1 O Unit Weight Wet. }~ ~~•'`12 f~,f Unit Wei ht Dry 9.25 P~ D`,Y r-7~~:38_I~~ ~ 4;12y„4I~. Strength D~MLw16~oI~SVo1•= x•616 Ina = 108.59 cL, 'D • '3.6d ~ C-6"t.5/1o6.S9~tC1.4~ = 9.15 P~• /~ cm Final Diameter D f 1.38` cm o f A,~ ~~ • X19 cm2 ~ Final Area A ~ •~9 a fin cm= f 110 ! << •~lb ~ e cm =ti,(c8~ Final Height H e 4.424" cm Vo ~Z ~ ~~-~ cm3 Final Volume Ve ~• ~~~1n3 cm3 tog ,5g cc. t 2.54 Ao N..I~,,.~ Corr. Area . , „__. ~_____ ELA-SEO TIME•MIN• LOAD DIAL IN O.000I•• AXIAL LOAD P KC STRAIN DIAL IN •OOI•• TOTAL STRAIN INCHES UNIT STRAIN CORRECTED 2 ARE A.CY STRESS 2 KG/CN ~ S ~ • O O ~ `t ~ .0 25 ~.~ ;b ~~ 7~ y ,goo S 1 ~..5 . 5Z ~~ 2 ~5 •1'15 .o ~13 ~b.5~~ 2.3-T - 5~ .20~ ~~ 5.. _ ' -~ ~ uNCUNr1NED COMPRESSION TEST - DU1 1 ~ I Name ~ ~.c rn (~C 11 d Date- ~~ / ~ / ~ G Job No. Location boring No. R' Z ~ L~ , A ~ L- 1 Sample No. Depth/Elev. S ~ ,~ , (lescription of Sample ~~1~~4~ tU~.t ii ~, ' Proving Rinq No. ~ ~~~ S5 C-hn 1~~' . Apparatus No. Water Content Determination - Tare No. _ .~1~ 1 ~ ' Wt. Specimen Net -~-. Ta e - 190 .~ gms. Wt. Specimen Dry -{-. Tare gms, 38.6 . 2~, 5 / '!r; ~ ' W4.3 Wt. IYater 3~g • gms. Water Content in ~ Dry WC'. Wt. Tare ~. g p gms. ~18z.q/ ~Z.4 at 10.5°C Z~_~ ' Wt. Specimen Wet ~ Z. 1 ~I~~v ~Z5 ~' Pc gms. Unit Weight Wet 19t. Specimen Dry 14y ~ 3 gms, Unit Weight Drv _~ IZ.43 p~~~ l.;nconfined Compressive Strength Initial Diamcter Do /- 3'~a~ cm~ ' Initial Area A~ ~0 ,~(D(~ cm2 Initial Height f~o 1I ~ % ~ i~5~ cm Initial Volume o V 3 '9 ~ • ~~i~ 0 cm ,Test Data i C i 'Failure Conditions Remarks ADVANCE - ,DSOIL MECHANICS . 1 300 S.1 st ST. # C • Mount Vemon, WA 98273 • (360) 336-5641 /FAX (360) 336-5641 Final Diameter De 3 . S~n g cm Final Area Ae Q 9'99 ` •cm2 Final Height He g•h 1 0 cm Final Volume Ve a~ •Og9 cm3 2.54 _ A u.. Corr. Area - - LOAD AX A . - uwa ~ again ELA/SED TINE-MIN. O~AI ~N 0.0001" I L LOAD PK° STRAIN DIAL IN .001" TOTAL STRAIN INCHES UNIT STRAIN CORRECTED 2 ARE A. CM STRESS 2 K6/CY N ~~ 1~ r 0 ~3 5 ~ 1 ~ ~o SO 1 75 $ Ibp ~ ZS q So ~ o ~s ~~ o ~ L ZS ~Z S6 13 ~ ~ ~ z~ o.z , a ~~ ~ ~o ,qo~ 0,62 ~z33 uiv~uwriivtu cuMNKt551UN TtST - DU1 J N~Ime _ ~~,C`M1 /1 ~ 51n POIv~~' Date_ ~~/ LI ~ (p Job No. Lor.aLion boring No. A'2 ~ ~- 2 Sample No. _A Z ~ L-Z Depth/Elev. i ' Proving (Iin~; No. Apparatus No. Water Content Determination • ' Tare No. ~ ~ / Wt. Specimen Het ~- Tare Zb d gms. Wt. Specimen Dry -{-.'rare 2_ 2~•~ gms. w. w__ 7~Q i ~ "" '•°~°a ~~'~~ gms. Water Content in ~ Dry Wt'. / Wt. Tare 1 ~ ~ gms, at 105°C _~ 1 ~ b~ q, L ~30.~4 P~ Wt. Specimen Wet ~ gms.. Unit Weight Wet Wt. Specimen Dry ~-~ gms. Unit Weight Dry ~ _ , Unconfined Compressive Strength Initial Diameter Do f 3+ ~oD9 cm Final Diameter Initial Area A/ ~0.~•3 cmi Final Area ' Initial Height 110 . ~ Z I ~~ cm .Final Height Initial Volume V ~~~'~,~ cm3 Final Volume 0 'Test Data L u ,Failure Conditions fiemarks ADVANCED S01L MECHANICS . 1 ~ ^:: 300 S. 1st ST. # C • Mount Vemon, WA 98273 ~ (360) 336-5641 /FAX (360) 336-5641 ~ ~, De 3.5gg cm A _ ~0. (~ ~ cmi e He ID .`i By cm ~/ ~ 0(0.0 ~ cm3 e ,. ~ z. sa _ . ,.0 3 Ao • (20o u.. 4Z Corr. Area _ .~ .._ ELA-SEO TIwE•MIN. LOAD DIAL IN O.000i" AXIAL LOAD P KO STRAIN CIAL IN ,001" TOTAL STRAIN INCHES UNIT STRAIN CORRECTED 2 ARE A. CM STRESS 2 K6/CM y~ ~S 0 b . 25 3 S6 y ~~~ 4 ~~~ 5 Ls 5 ~o - ~S ~ 3.G2 Z ~ a a.2o0 ~ b423 10. ~8 Z •339 _ ~9 ~} s .:r. ~_ y- . 3 -. ivame UNt;UNF1NED COMPRESSION TEST - DU1 Date Job No. Lnration n boring No. __ A-~ L~ ~ Sample No. A-~ ~--~ Depth/Elev. ' Description of ample ~11 \ (?• 1 S~it'~- I,h;C~ ~(~ ' Proving fling No. A arat N pp us o. Water Content Dete rmination T~St ~~~~.¢, r,ar~6~~~ ; Tare No . -_ '~ ~b bac~~-Ior-Q.: 302.10 g ~c~o.t~ ; Wt• Specimen Aet -}- Tare gms, wt.~ _ Zg`1.9 9 ~S Wt. Specimen Dry -~-.Tare ~•2 gms. , Vb1. ~ SI.$~ 9 V/1 9 S ` ~ ~S~ Wt. 1Yater t b gms. ; ~`t V. ~1 1 xC1.4= z 1,41 Water ontent in ~ Dry t, ~o ~~n Wt. Tare Wc. Specimen Wet ~ • ~d ~ gms. gms. at lOS°C Unit Weight Wet z~-LPG i2 ~ •4 -~' Wt. Specimen Dry gms. Unit Weight Dry ~Oa.49 P~ ,~~ae~ n4 4uc.1 4u~ )~.Q4rTe~~ . ~L'n~onfined Compressive Strength Initial Diameter Do. 3~ ` ,I cm Initial Area Ao ~Ib.ZC} ` cm2 Initial Height `Ho _ ~~i• 8o cm Initial Volume yo ~15 ~,CJ~cm3 ' ~o~ a~y~~,>.~} = 4.13. ~ cm Final. Diameter Final Area. Final Height Final Volume Te s D@ t a ~ 2. 5 4 _. I'~ I Cc wa~ w•h - t t1q : '] 3.5 Q 3 C m H e 1 0 n i ' Failure Conditipn~ rt Remarks SOU 1'Q, - ' ~ -n.c c~ ~ -+C~-t• ' RAT tom) SO t3 ~ ADVA NCED SOIL MECHANICS 1 300 S. 1st ST. # C • Mount Vemon, WA 98273 • (360) 336-5641 /FAX (360) 336-5641 pe 3.5~ 3 cln Ae - ~~ . ~~~ •cm2 He 4 ~, 3 I cm ye y, . 9 ~9 cm3 Ao Corr. Area . , „__ _ ~____ _ ElA-SEO TIME•MIN. LOAD OIAI IN O.0001'• A%1 A~ LOAD P %O STRAIN DIAL IN .001° TOTAL :STRAIN INCHES' UNIT STRAIN CORRECTED ARE A.Cw2 $TRESS •• KG/Cw2 -- ..-•Y_•• /~~~ C ~ b --- _ . ('IQa~ Node i LS T~ ;, 5 ~ ~; ~ ,< 1Q ~ can - I~-~ b ~ b ~" Sv , . . ~ .. .~ . , ~~)-r,9 ~n rclvk~v-,~ ~. Win',} wei3~~S ; `K Mo~ ~~ ~1~ S 5~.,~~.. ~,G ~ ~}0 6~ ~~ I b a +~-, ~v.El .~~~ AsT~ D 30 ~ o •- Si,~o.~'T~~ . =~ bv'~h 4r-a_. c.c arm r~.~tr ~o ~t~... f~v (~ ~~1® {{ '~es~' n c mac. . ~'~ 1 t 512' , 250 0.250 O.Oy~9 ~o, oo .535 = •la9 ;, _ iti ame uNCuiyFiNED COMPRESSIDN TEST - DU1 Date Job No. ' t_oracion R IIorin~; No. __ ~-~ L~ 2 Sample No. ~ ~ ~ L' 2 Depth/Elev. I ' Proving Rini; No. Apparatus No. _ Water Content Determination ' Tare No. Wt. Specimen N`et -}- Tare gms. ' Wt. Specimen Dry -f- Tare __ gms, Wt. IYater gms. Water Content in ~ Dry Wt. Wt. Tare gms. at 105°C y, ' Wt. Specimen Wet gms. Unit Weight Wet gm/cc Wt. Specimen Dry gms. Unit Weight Dry gm/cc ' t;nronfi d C ne ompressive Strength Initial Diameter Do, cm Initial Area Ao cmj Initial Height `H cm o Initial Volume Vo cm3 Test Data 2.54 = u„ L 0 C! i De c m Ae • cmj He cm Ve cm3 Ao Corr. Area . , „_:.-~.____ ELA/SEO TIwE•A/IN. LOAD 01 AL IN 0.0001• AXIAL t.0A0 P KG STRAIN DIAL IN .001° TOTAL STRAIN INCNES UNIT STRAIN CORRECTED j. #REA-Cw STRESS j KG/CM Final Diameter Final Area Final Height Final Volume ADVA NCED SOIL MECHANICS 300 S. 1st ST. # C • Mount Vemon, WA 98273 • (360) 336-5641 /FAX (360) 336-5641 DU - 1 UNCONFINED COMPRESSION TEST - DU1 Nllme Date Job No. ' l.oraLion Doring No. ~ - ~ _' Sample No. ~ ~ ~ ~-' 2 Depth/Elev f)escri pcion of Sample , +*.;~ ~ ;t. i1 ~.\ ~~ ~ ~~ ~ Ci ;ti ~~ . '',,.'_~-~ ',~ ,~ `: Pruvtng Rini; No, A aratus No pp . Water Content Determination ' Tare No. Wt. Specimen Net -}- Tare gms. 1 Wt. Specimen Dry -~ Tare gma. Wt. IVater gms. Water Content in y Dry Wt'. Wt. Tare gms. at 10 5°C qo ' Wt. Specimen Wet gms. Unit Weight Wet gm/ec Wt. Specimen Dry gms. Unit Weight Dry gm/cc ' l ~nco fi d C . n ne ompressive Strength Initial Diameter Do cm Final Diameter De cm Initial Area Ao cmZ Final Area Ae cm2 Initial Height `Ho cm Final Height He cm ' Initial Volume Vo cm3 Final Volume Ve cm3 Test Data 2.54 No = Corr. Are A a . ~ _ 11~; f° ~„~,,,_ ELAPSED TIME•MIH. LOAD DIAL IN 0.0001" AKIAL LOAO P KG STRAIN DI ALIN ,001' TOTAL STRAIN INCHES UNIY STRAIN CORRECTED 2 ARE A. CM STRESS T KG/CM t. ._` ,, ' Failure Condit ons Remarks ~~.; 1 ADVANCED SOIL MECHANICS 300 S. 1st ST. # C • Mount Vernon, WA 98273. • (360) 336-5641 /FAX (360) 336-5641 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 L.1.7 Ii ;',/I~OJ i, it Vim. SPECIALIZING IN PHYSICAL SOIL TESTING TO: J. B. Scott 8 Associates 3601 West 5th Street Anacortes, WA 98721 ATTENTION: Jim B. Scott SUBJECT: Bainbridge Marine Services, Inc. Russell Trask Termination Point Property Hood Canai Bridge RE: Sample ID No. A2-S2 and A3-31 We are sending the following items: Date: 11-22-96 Job No.: J-1006 Date Co ies Descri tion 11-22-96 1 Triaxial Stren th Tests Consolidated, Undrained Fi ures 1 throu h 8 11-22-96 1 Shelb Tube Visual Descri tion 2 a es 11-22-96 1 Atterbe Limits Fi ure 9 These are transmitted for your use. Remarks: Samples were tested in general accordance with ASTM D-4318, ASTM D-4767 and ASTM D-2488. Please call if you have any questions regarding this submittal or presentation of the data. Thank you. Best Regards, S®~. ~C~~1~T®~.,®GY, II®TC. .-----~- G~~ - Ri and G. Sheets, Vice President 3000 a 2000 v L Y L ~ 1000 3000 2500 a 2000 a~i 1500 L 0 1000 +~ a 0 ~ 0 1000 2000 3000 4000 5000 6000 Totol Normal Stress, psf effective Normal Stress, psf 0 500 0 ~ 0 10 20 30 Axicl Strain, TYPE OF TEST: CU with Pore Pressures SAMPLE TYPE: Shelby DESCRIPTION: Groy Clay SAMPLE NO WATER CONTENT, -~ DRY DENSITY, pcf H SATURATION, % H VOID. RATIO H DIAMETER, in HEIGHT, in WATER CONTENT, P' DRY DENSITY, pcf u, t1 SF,:i'~~RfiTION , ~ VOID RATIO DIAMETER, in Q HEIGHT, in Strain rote, in/min BACK PRESSURE, psf CELL PRESSURE, psf FAIL. STRESS, psf ' TOTAL PORE PR., psf 40 ULT. STRESS, psf TOTAL PORE PR., psf 6~FAILURE, psf 63 FAILURE, psf CLIENT: RUSSEL TRASK 1 42.6 75.6 95.0 1.189 2.87 6.04 35.0, 85.8 170.0 0.928 2.70 5.99 0.0030 8fi40 10800 2174 9850 2133 9864 .3124 950 PROJECT: Terminal Point Property LL= 48 PL= 22 PI= 26 SPECIFIC GRAVITY= 2.65 REMARKS: Substontiol organics Fig. No.: 1 SAMPLE LOCATION: A-2 S-2 17.5-18.0' P~OJ. NO.: 1006 DATE: 11/20/96 TRIAXIAL SHEAR TEST REPORT SOIL TECHNOLOGY, INC. 10000 i ~ 8000 ~ ~ L (() N ~ 6000 ~ ..~ .,- o ~ N L a 0 4000 ~ v a •- a. > _ 0 2000 v 0 ~- 0 0% 10% 20% 10000 i ~ 8000 ~ ~ ~ ~ 6000 ~ ~ a~ ~ w N a ~ ~ p 4000 ~ r ~ o o •- ~ > 0 2 0 _ 0 0 0 ~ + 0 0 0% 10% 20% 1 200 ~- N a o' 600 0 i i i i v ~ 0 600 1200 1:800 2400 3000 3600 p, psf Stress Paths: Total Effective - -- End -~ Client: RUSSEL TRASK Project: Terminal Point Property Locution: A-2 S-~ 17.E-18.0' File: 1006A2S2 Project No.: 1006 Fig. No.: 2 ~oo~u 8000 6000 .4000 2000 0 0 10000 8000 6000 4000 2000 0 0 10~ 20% I 10% 20% 1 1 6000 a 4000 a~ ''Y^^ V1 y 2000 6000 5000 n. 4000 m 3000 0 2000 O 0 1000 0~ 0 2000 4000 6000 8000 Total Normal Stress, psf Effective Normal Stress, psf SAMPLE N0.': WATER CONTENT, J DRY DENSITY, pcf _ H SATURATION, % ,_ ... H ~ VOID RATIO Z DIAMETER, in H ;- HEIGHT, in WATER CONTENT, ~~FY ~EN~ITY, pcf ,__._ w SATURATION, . ~ VOID RATIO • ~ DIAMETER, in --- 'Piclii~lT~i i n Strain rote, in/min BACK PRESSURE, psf CELL PRESSURE, psf FAIL. STRESS, psf TOTAL PORE PR., psf 40 ULT. STRESS, psf TOTAL PORE PR., psf ~'~ FAILURE , ps f 63 FAILURE, psf CLIENT: RUSSELL TRASK loooo 12000 0 ~ 0 TYPE OF TEST: CU with Pore Pressures SAMPLE TYPE: Shelby DESCRIPTION: Grey clay (CL) Top of sample silty LL= 42 PL= 20 PI= 22 SPECIFIC GRAVITY= 2.65 REMARKS: slickensides failure plane 60 degrees lFig. No.: 3 1 32.8 91.4 107.5 0.810 2.84 6..03 29.4 92.9 100.0 0.780 2.83 5.99 0.0040 7200 9792 5675. 7243 5667 7286 .8223 2549 PROJECT: Termination Point Property SAMPLE LOCATION: A-3 S-1 21.0-21.5 i'ROJ. NO.. J-1.006. DATE: 11/1496 TRIAXIAL ~I1EAR TEST REPORT ~; ~CI"~_ TECHNOLOGY , INC . 10 20 30 Arial Strain, i 10000 i i ~ 8000 N ~ t ~ ~ ~ 6000 ~ L ~ .~w v ~ ~ L ~ a 0 4000 o ., o o .- a > _ 0 2000 0 ~ . 0 0 0% loooo 8000 v ~ ~- N N ~ 6000 N ~ a.~ y- ~ N ~ a L 0 4000 v .~ o c .- ~ > _ 0 2000 0 0 0 0% 2000 a ~ 1000 0I ~ ~ I / I i i 0 1000 2000 3000 4000 5000 6000 P~ psf Stress Paths: Total Effective --- End -}- Client: RUSSELL TRASK Project: Termination Point Property Location: A-3 S-1 21.0-21.5 File: 1006A3S1 Project No.: J-1006 Fig. No.: 4 in% ~n~ ~ VJ~/ 8000 6000 4000 2000 0 0 looao 8000 c~000 4000 2000 0 0 ~; 10% 20% 10~ 20~ 10% 20% 6000 a 4000 a~ ~ 2000 6000 5000 a 4000 ~ 3000 0 2000 0 1000 0 ~ 0 2000 4000 6000 8000 Total Norma) Stress, psf Effective Normal Stress, psf SAMPLE NO.: WATER CONTENT, ~ DRY DENSITY, pcf H SATURATION, % _... F-I ~ VOID RATIO Z DI.gMETER , i n G F~ 1E~~~~~T, i n WATER CONTENT, ~ DRY DENSITY, pcf v' , S.^,T"RATION , °lo ~ VOID RATIO Q DIAMETER, in HEIGHT, in Strain rote, in/min BACK PRESSURE, psf CELL PRESSURE, psf FAIL. STRESS, psf TOTAL PORE PR., psf 20 ULT. STRESS, psf TOTAL PO~;E PR . , ps f 6~FAILURE, psf 63 FAILURE, psf CLIENT: Russe(i Trask 10000 12000 0 ~ 0 TYPE OF TEST: CU with Pore Pressures SAMPLE TYPE: Shelby DESCRIPTION:. Gray clay LL= 45 PL= 22 PI= 23 SPECIFIC GRAVITY= 2.65 REMARKS: Fig. No.: 5 1 35.8 88.4 109.0 0.871 2.84 ~ 02 32.1 89.4 100.0 0.850 2.83. 5.97 . o.ooao 7200 9792. 4297 .7963 4297 7963 6125 1829 PROJECT: Termination Point Property _-,^s1P,.r Ln''ATION: A-3 S-1 .20.3-20.8 ROJ. NO.: DATE: 11/20/96 T?I~~.XIAL SHEAR TEST REPORT SOIL TECHNOLOGY, INC_ 5 10 15 Axial Strain, i i 10000 i ~ 8000 N to ~ m ~ ~ 6000 ~ .~4- a~ ~ ~ ~ ~ a o .4000 ~ ~ o o ._ d > _ 0 2000 0 - , 0 0 0 10000 ~ 8000 N cn N ~ 6000 ~ ~4- ~ ~ ~ t1 a L 0 .4000 0 ~ o o .- ~ > _ 0 2000 a 0 10% 20°'_ IOuUo .8000 6000 4000 2000 0 0 10000 800 .6000 4000 2000 0 10% 20% 0% 109' 209' 2000 a ~ ,000 o~ 0 1000 2000 3000 4000 5000 6000 p, psf Stress Paths: Total Effective --- End -{- Client: Russell Trosk _ Project: Termination Point Property Location: A-3 S-1 20.3-20.8 File: 006A3S12 Project No.: Fig,' No.: 6 Peak Strength ~~ ~ . _. Totai Effective o= 0.00 psf ~',~ cx = 30 . 1 deg ~,, ~~ ton cx = 0.58 ~.~' ;_ __ _ -- - -~ ~ _. ~_ _ _ T ,, . , ,~ I. - , ,. l ,,. % 10% 20% 6000 ~n a 4000 a~ .~ ~ 2000 L 0 6000 5000 Q 4000 ~ 3000 L ,ter. TOTAL EFFECTIVE ~ C, psf 0 _ ~~. , ~ , d e g 3'' 3 ~ . ~ _. . - -----+ i TAN 0 . 63 / ~ ~ ' 0 2000 p 2000 +~ .~ m 1000 0 0 C 4000 6000 8000. 10000 Total Normal Stress, psf Effective Normal Stress, psf _: SAMPLE NO. 1 2 WATER CONTENT, % 32.8 35.8 4 cf 91 4 88 DRY DENSITY .. . , p rl SAT' ~r~,-i' ZON . % ~ 07 . 5 1-09 . 0 ~ H VOID RATIO 0.810.0.871 Z H DIAMETER, in 2.84 2.84 . .. ~ - HFTGHT, in 6,03 6.02 : '__ _.. WATER CON TENT . % 29 . 4 32 . 1 ' ~ DRY DENSITY, pc# 92.9 89.4 ;_ . _ w SATURATION . % 100 .0 100. 0 ~ VOID RATIO. 0.780 0..850 ~ Q DIAMETER, in 2.83 2,83 HEIGHT, in 5.99 5.97 ,; ~ St ra i n rate, i n/mi n o.ooao o.ooao ~~ BACK PRESSURE, psf 7200 72.00. CELL PRESSURE, psf 9792. 9792 FAIL. STRESS, psf 5675 .4297 TOTAL PORE PR. psf 7243 7:963 10 20 30 Axial Strain, TYPE OF TEST: CU with Pore Pressure s SAMPLE TYPE: Shelby DESCRIPTION: Grey clay (CL) Top of sample silty LL= 42 PL= 20 PI= 2 SPECIFIC GRAVITY= 2.65 REMARKS: slici<ensides failure plane 60 degrees IFig. No. : '] 12000 ROJ. NO.: J-1006 DATE: 11/14/96 TRIAXIAL SHEAR ,T EST REPORT SOIL TECI~NOLOGY , INC . 40 ULT. STRESS, psf 5667 4297 TOTAL PORE PR., psf 7286 7963 6~FAILURE, psf 8223 6125 63 FAILURE, psf 2549 1829 CLIENT: RUSSELL TRASK :-!?~Jc.~•-~ germination Point Property SAMPLE LOCATION: A-3 S-1 ~~ 100uO i ~ 800G ~ ~ ~ ~ 6000 ~ .~ ..- ~ ~ ~ a ~ 0 4000 ~ .~ o °_ > _ 0 2000 o 0 0 10000 8000 6000 4000 2000 0 O 10000 8000 6000 4000 2000 0 C 0% 10% 20% 10000 i ~ 8000 ~ m ~ ~ 6000 ~ .~~ ~ ~ ~ ' L ~ Q O 4000 N ..~ o ~ > _ 0 2000 0 , .. o ' 0 0% 10% 20% Peak Strength ~~~ ' Total Effective o= 0.00 psf ~.~i 2000 cx = 29 . 4 dc:c~ ~~ - - -... ~~ _ ' tan cx = 0.56 ~ ~~ (_ ~ / ~i ~ I ~ ~ ~ i~ a ~ ~~ ~~. ~ 1000 ~ ~~ ~ 1t ~ ~ 1, 1 // ' l1 (~ ~ ~ <. 11 O 0 1000 2000 ' Stress Paths: Totol Client: RUSSE~L TRASK ' Project: Termination Point Property Location: A-3 S-1 File: 1006A3S1 Project No.: J-1006 % 10% 20% 10% 20% 3000 4000 5000 6000 p, psf Effective --- End -{- Fig. No.: ~ _) i~ ~~ fl 0 ii C~~ SHELBY T:BE',':'J SL DESCRIPTION Job Hood Canal Bridge Date 11/8/96 Job No. J-1006 ~„_ __ Sample Pushed by RS Exploration No A-2 Sample Lagged by RS Sample No. S-2 Type of Sample X shelby -other Depth of Sample 17.3-18.5 Diameter of Sample 2.85 (inches) Sampled Length (from log) (feet) Sample Quality -good X fair -poor _ Disturbed Sample Recovery 1.5 (feet) Specimen Water Test Depth Core Classification and Description saved content Type (ft) 17.0 a>~ ;> FDisturbed 17.5 • f-Red Rock (-Lightly Shaded Area Contains Roots and Wood 43 CIJ Gray; Moist, Medium Stiff Ciay with Roots or Organics 36 ~1IIC 18.0 Gray, Sandy Silt 38 WC FSand Lens Gray, Stiff, Moist, Clay, CL 36 WC 18.5 Bottom of Recovery Cut by Other i This portion retained by Advanced Soil Mechanics Soil Technology, Inc. J-1006 1 SHELBY TUBE VISUAL DESCRIPTION Job Hood Canal Bridge Date 11/18/96 Job No. J-1006 Sample Pushed by RS Exploration No A-3 Sample Logged by RS Sample No. S-1 Type of Sample X shelby -other Depth of Sample 19.0-21.5 Diameter of Sample 2<85 (inches) Sampled Length (from log) (feet) Sample Quality -good -fair -poor _ Disturbed Sample Recovery (feet) Specimen Water Test Depth Core Classification and Description saved content Type (ft) ; , 19.0 This portion retained by Advanced Soil .Mechanics 19.5 T 20.0 ~ Cut by Others - ~ ~_ _ Top of Recovery Gray, Moist, Medium Stiff Clay. with sand tense E-Clay, CH with Slickensides 31 WC 47°~ ~ ~'~ 20 5 Gray,.Moist, Medium Stiff Clay, CL-CH . 36 C!a ~3 k~; ~~ y ; ~;~~, , Torr Vane = 0.35...tsf, Penetrometer = 0.25 tsf F Silt Lense 21.0 Gray, Moist, Medium Stiff Clay; CL s ~a;: T.`r ~~~rl ~ 33 CU.#~ Gray Moist Stiff Clay ,~, ,, . ~~~., ,,~ 21.5 Torre Vane = 0.70 tsf, Penetrometer = 2.5 tsf ~~ ~~~ Bottom of Recove ~ _~ Soil Technology, Inc. J-1006 1 1 1 1 1 1 1 1 1 1 1 Plasticity Chart ~'~.LivartceG S~~il Mechanics Termination Paint Property 70 60 50 X ~ 40 U .~ `~ 3 0 ~v a 20 to 0 0 10 20 30 40 50 60 70 80 Llquid Lirnit Symbol Boring Sample Depth Water Content in Percent Classification Number Number in feet Nat. L.L. P.L. P.I. • A-2 S-2 17.3-18.5 43 48 22 26 CI. M A-3 S- I 21.0-2. 5 ~; ~'. 2 20 22 C L • A-3 S-L 20.3-20.8 36 45 22 ?3 CL Nat. Natural L.L. Liquid Limit P.L. Plastic Limit P.I. Plasticity Index -----i--- -T-- , ~, _ ~ ' i_ I I T H C .. _ I ~ ~ j ~~, i C ~ i ~ i i I i ! ~ I ~ I V`~e i • .. ~~~ P i ~ ~ ~ ! MH o.r 0H ~ ~ --- .~;'~ ~~;~ ~ M L oar 0 L I Soil Technology. Inc. J-1006 90 tOG r~ i i i i i SEIRE CONDOMINIUM EARTH MOVEMENT INVESTIGATION TERMINATION POINT, WASHIPJGTON r PAUL R. WEBER CONSULTING SOILS ENGINEER. ~. 1200 WESTLAKE AVE. N. SEATTLE, Y:ASHINGTON 96109 - (20G) 263-0t80 Zlarch 1, 1974 William S. Tsao & Company 2340 Sea-First Bank Euilding Seattle, Washington Attention: t•:illiam Tsao Gentlemen: This letter transmits our Report of Earth 1`iovement Investigation, Seaire Cor_dominium, Termination Point, ktasiiington. This work has been accomplished in accordance with our proposal of January 28, 1974. It has been a pleasure to perform this service for you and we look forward to assisting you during the construction ' phase of this project. Sincerely, ~ `-' '~i(.~C. ' Paul R. Weber, P.E. a PRW:as ' Enc. ~ ~. 1 ~~. EAP.TIi MOVEPIENT INVESTIGATION SEAIRE CONDOi4IrIIUI•i TERPtINATIOiJ POINT, [ti~ASH. INTROllUCTION 1 We present in this report the results of our investigations at the site of the proposed Seaire Condominium on Hood Canal. The ' site is located south of the west tezzninus of the Hood Canal Floating Bridge in an area called Termination Point. The primary purpose of ' our investigation has been to e. lore a lar a area o }'p g f earth movement ' which was first noticed at the site in late January of this year. A brief reconnaissance of the area revealed that a section of ground ' approximately 1200 ft. long had moved laterally toward .the beach. A program of field exploration was then undertaken to provide data ~•. on the subsurface stratification, groundwater conditions, and the mechanism ' of earth movement. This data has been used in formulating recommendations for stabilizing the area. ' SITE CONDITIONS The 34 acre site can be divided into two topographic provinces; ' a lower bench area and an area of higher ground. The upper area, with elevations ranging from about 150 to 250 ft. above sea level, ' is characterized by moderately rolling terrain with a redominate slo e P P to the southeast. The upper level ends at a steep bluff parallel to Hood Canal. The lower bench level is an area of highly disturbed ' ground with steep slopes and undrained depressions that is the site of an ancient slide. The bluff c:*hich ends the higher ground area is '' the scar of this r. ._ p 2 dent slide. Elevations in the lo~.er bench range ' between about 55 and 70 and then drop on a steep slope to the beach ,,~~ (2 > ~` ' level. Subsurface conditions were e~:plored ' ~ One boring was located above the scarp on borings were located in three lines on tl ' data on subsurface condition, groundwater by means of ten borings. undisturbed ground. 2yine ze lower bench level to provide levels aid the location of ' the failure plane ~:hich defines the lower boundary of earth movement. Six of the nine borings on the lower bench were produced using the ' Dutch Cone Penetrometer. This device measures the resistance of the soil to an instrumented probe, giving an indication of the strength and consistency of the soil at 8-inch. intervals of depth. The boring locations are shown on the Plot Plan, DG g. 1. Borings advanced in the conventional manner by drilling and sampling are designated c.*ith the Letter B, and the Dutch Cone Penetrometer tests are designated with the Letter P. The upper boring,, supplemented by a general geologic reconna_ssance ' of the area indicates that the natural depositional sequence, where unaffected by earth movements, consists of the following: From the beach level up to about Elevation 130 to 150 is a massive deposit of overconsolidated glacial clay called stiff-fissured clay. The clay is overlain by glacial till, which is a very dense ' matrix of well sorted materials from silt size to gravel and cobbles ' which was compacted directly under the glacial ice. Where it has not been eroded, the glacial till is overlain by glacial outcaash sand, cahich is a brocan, fine sand. It is knocY-n from one boring, boring B3, that the glacial clay is underlain below beach level by ' a thin deposit of marine sediments and then. an extensive deposit ' glacial sand. f ~ ~3~ ~• 1'~. The stratigraphy just described could not l;encrally contain a static groundwater table since all the materials, with tl~e exception of the outwash sand at the highest elevations,,are very impcrr~~eable ' and transmit water only in seams or lenses of granular material, or ' in cracks and fissures which have formed in the clay. Borings within the lower bench area reveal the remr.:~nts of these ' geologic formations, although in a highly distorted and disarranged sequence. The. borings in the lower bench area generally reveal a slide mass approximately 30 to 50 ft. in thickness. Within this ' thickness, soils are highly disturbed and softened with .moisture contents several percentage points above their former condition. Inclusions of organic debris and highly mixed soil types are found within. the. upper 15 to 25 feet of the disturbed zone. The slide plane itself is almost ~~~ exclusively with the layer of overconsolidated glacial clay. Within a ' few feet below the bottom of the slide mass, the overconsolidated clay. .f becomes hard and Moisture contents drop to the usual moisture content ' •obtained from intact specimens of this material. The subsurface conditions ' within the lower bench area are depicted on three subsurface profiles on I?wgs. 2, 3'& 4. These sections show the general soil conditions encountered, ' the best estimate of the location of the failure surface, and the ground- water conditions at the time of the field explorations. ' High groundwater-. tables were generally found on the extrer:e ends .. -~ ~. _ ' of the bench, while the middle section contained only seepage zones. .' . ---. At the completion of the field explorations, three inclinometer ' casings were installed in the three borings on the lower bench level. Readings on these casings have disclosed rapid movements of the slide mass, ' particularly on the east and west ends. Continuing readings will demonstrate how the slide mass is progressing,. and ultimately, 1~ 1 1 1 1 1 1 1 1 ~, 1 1 1 1 1 1 1 1 1 ~ ('+) l . whether it has been stabilized by remedial measures which will ve pro- posed in the ne::t section. Laboratory tests were performed on samples of soils obtained from the borings in order to determine accurate classification of the materials, natural water content, grain size distribution, and other characteristics of the soil, which aid in our understanding of the slide conditions and best methods for controlling this large earth movement. The results of these tests are shown on the boring logs Dwgs. 5 thru 8 and on separate sheets where appropriate. ,~ ~_ c CS) ' F.c~RTH MOVFI•iLNT STABILIZ ATION ' The primary puzpose of this investigation is to provide remedial - measures to eliminate the present earth movement by stabilizing the lower bench area so that residential structures can be safely constructed. ' It is our opinion that this slide can be effectively stabilized by __~._-- r means of a combination of surface and subsurface drainage and by the •-- - construction of a buttress fill with rip rap protection from wave erosion. .r•v -~-- -- -- ~ _- -- --- - -~------ y~y-. The slide mass itself should be dewatered with horizontal drains. ' Since the ~~~~ groundwater in the slide area appears to be concentrated ~~, nl ~h ' on the two extreme ends `of the bench, we recommend that horizontal N~{ drains be concentrated in these two areas. Preli.mi:nary installation should consist of four drains in each area, installed to a length of about 200 lineal feet. These drains can be constructed from beach ~•' level and will ene p trate into the slide mass where groundwater is ' concentrated. A second important drainage provision for the lower bench level is to cut off the access of surface water into the slide mass in the ' scarp area. This should be done by constructing a ~ench drain along the entire length of the scarp in a trench some 4 to 6 ft. deep. A - --~- ~. pipe of suitable size should be bedded in clean gravel backfill. This ' trench should then receive 24" of: impermeable clay_backfill, carefully compacted into place, and topped with an asphaltic .concrete surfacing. ' This drain s}rsten should not be installed until the slide mass is stable, ----_.. since excessive movement would disrupt its effectiveness. Our analyses indicate that a buttress fill with a beach width , ' t' ~' of 30 ft. and an average heighth of 15 ft. will produce enough resistznce ~- . at the toe to maintain a stable condition in the slide, provided that groundwater access is cux.off by the drainage provisions recommended ~.. (6) bove. This buttress fill should consist of compacted granular borrow a -___. ' obtained primarily from the. site on the upper level, or from a nearby ----~, granular borrow source. The material should L-e placed in thin_lifts ' and thoroughly compacted by means of the hauling equipment used to r'~-_~ transport and place the material. After the construction of the buttress, ' a heav ri -ra facin should be placed on the water side of the fill. y P P g ' This buttress should be at Least 10 ft. in height and consist of three --~, and four man stones placed on an angle of about 1/2 to 1, horizontal to vertical. A typical buttress section is shown on Section EB, Dwg. 2. Before the buttress is placed, it will be necessary to perform ' some site preparation work along the beach. Fallen trees and vegetative debris should be stripped and stockpiled for burning or disposal. .~~ Areas on the beach that contains softened clay slide debris should be stripped to firm, .intact material. It does not appear that such areas will be very extensive. ' A further requirement of drainage has been trans~,tted to you in our earlier conversations. This drainage consists of the handling ' of surface and near-surface infiltration of water on the upper level ' that could find its way into .the lower bench area. All roof drains, street surface drainage and parking 1ot_drainage should be carried in tight lines to disposal in the Canal. In addition, we recommend that certain stretches of the upper region have french drains installed that will cut off the near-surface groundcr~ter flow ~•~hich might make ' its way •over the scarp and into the slide area. These provisions have • already been incorporated into the project plans. ' I1.1SPiCTION AP:D )`10NITOP.ING Iffpartant earthc•~orl: construction should be inspected by a qualified E i (. (7) geotechnical engineer to assure that proper materials and techniques are being used to complete-the very ic:portant drainage and buttress construction projects. To supplement the inclinometer installations, we recommend that a network of survey bench marks be established which will permit stability monitoring of the ground in the lower bench area. FOUNDATION SUPPORT Wiper Level - Foundations in the upper level should bear on firm undisturbed soil at shallow depth. Footings bearing on dense glacial materials, ' either outwash sand or glacial till, may be designed for an allowable soil bearing pressure of threee (3~s per square foot. Basement ;~:.•~~ f retaining walls in excess of 5 ft. fn Neigh may be designed for an ' equivalent. fluid pressure of 25 lbs. per cu. ft., provided that backfill consists of select granular soil. ~' ~' Lower Bench Level - Because of the highly disturbed and softened ground ' in the slide mass, buildings in the lo~,;er bench level will have to be supported on drilled piers. These piers must extend through the unstable material and obtain their bearing on hard, intact soil. We estimate that piers will average .between 30 and 40 feet in den~h The pier contractor can expect to encounter soft s ueezin round q g g ' with high water table in some areas. Respectfully submitted, 1 ,e ~~.~ Ft. 1N ~~ J ~p4 WASHY/r~~~ Paul. R. Weber, P.E. ,~ l PRW: as ~ ~`~ ,g ~ : y ay ~ . , ~~ ' ADO R~cisiE~~a G '` FF`S'S/ONA~ ~~ _ ~ ~ , _ - ._ CONE BEARING FRICTION RATIO ~ ~` ~ DEPTH CAPACITY (TON/ ft) _y oePr~+ a.t~r. F~ 1 t f b 20 60 100 200 X00 O ~ ~ K O fi4 GO 10 50 ' 20 ' ao 30 ~, 40 ' Zo 30 10 60 ,~~-. DUTCH CONE LOG ~~~ . J. C. 9.R.W. i SOIL INTERPRETATION ~ t~vr-noN 66S_. oucsal. as a«..a ~. rmu oovl2zm L]o/7i PROBE l SEAIRE CO-JD0411NiUtJ TER1rtt-.IATION F1~tNT, W/pSH. PAUL R. WEBER o 9_0l :O NSULTING SOILS fJ~IGiNEER i. b 1200WCSTI.AK[avC Ilowtll C~ iCATTLC.IMiK M100 =OS'a00 f 1. 1 1 1 1 1 1 1 [- 1 1 1 1 1 1 1 1 1 CONE BEARING FRICTION RATIO 9G DEPTH CAPACITY (TON/ ft) oEPrn EI~v ~ . fT. ft ~ s s a m ao wo =oo •oo o • • 1s O -1r GO 10 --11- 30 20 -11- 40 30 -I f- 30 ~ --1{- ZO 30 -{ ~ 10 so -iF- o . ~ ~-. , 1 ~-r-- _ ~ ~ i ~ 1' , - - .. . 1 r - i ~ - T . . .~ n{' ~ { .r ~ }.- +~ ~ :' r• w~ ~ ~ i~.+-- - ~ }~ - ~ ., I- ~ Yt ~ i t ! - - - - - r ~ - - - _ - ~ ~_ - _ - ~ ~ - - DUTCH CONE LOG / - - --~-- ~~I-_ _~ SOIL INTERPRETATION TOP ELEVATION ~O~ i~~ ~~ G1JS s-....• r... r~a.a eariss>m usn• PROBE 2 5 E A1RE CONDOMY~WM TEIZMIWATION PD~NT, WASFt 2"''' PAUL R. WEBER o q-a J.. CONSUlTIN4 SOILS ENGINEER c1.c 1xoo~stulct •v[ 11a1'ra 1 O P•R•w •[ATTL[.~-•1l••p• !•~-01.0 r ~- i ~\ CONE BEARING FRICTION RAT10 96 DEPTH CAPACITY (TON/ ft). oe~ Et~/. fT. FL O `~ 1 t • b !O W 100 7:00 X00 O • • I2 GO 10 50 20 40 30 30 40 30 --~ ~ _IO 60 -~ TO J i r ._"._ ++t• - - T"' 1 ~ •T'' ~- _,..,...t ~ U'~ - • i-i ;r- - ~ t r if ~- - ni~.._ ~'t N _ _ ~? ip . f ~~~ 1 .~ _ ~ _ > ~. r ^•- - _ . ~ f .~ i~t- - > - -r- ter{ / f;T~ - - --- - - - j ._ _ T . ; *r ~~i, ,~~ - - - - ~;,~ ~ ~ - - '~ T _ ~' 77 ~t _ - -- - ~.~ ~ 1 1 .- -- _ - - - --- - _- - ~ _ -,~ ~ j 1 -_ ' - - - _ ~~ DUTCH CONE LOG SOIL INTERPRETATION TOP ELEVATION rO? -ZIDL pi~t7t ox:at. a~ I_ a--- - - - .-- - moss calotaim 1/71/7 PROBE 3 SEAIRE, CONOO-ruNIUM TERMIAIATtON PomJT, w~SN. '_t9-~~ PAUL R. WEBER '0 9 OI .~ c. CONSULTING SOILS ENGWEER Y200NCtTLAK[ •VC IIOIrTN ' 1 Q. Q W, SE~TTL2.IYi/1. ••qf ! • ••OI.O ~, ~' ~~I CONE BEARING FRICTION RAT10 96 DEPTH CAPACITY (TON/ ft) ~~ FT. ft ~ s s a eo w 10o soo +oo o s • es O ~r 60 10 60 20 I.O 30 -~ E- SO ~O ~ ~~b 60 -t {"- o 7p JL_1o .--+,- ~^ T .J ~.o- ~...T T , i ~ t ~ ~ i ~ s ~4 - / j - r- - - f ~~t I~j - ~- - - ~II,~ - ~-~ - - i - -_ _. _ • --i ~•t' 1l f lip-- - _ - r^' 1~~ 1 , I~i!- i ~ - - - + - r , -- i DUTCH CONE LOG SOIL. .INTERPRETATION TOP ELEVATION rD~ ~ t y~r rras• rat CIAtLt OJ! ir~rtl !~M OJCLL fVm rRO~L 07f1tral 1/70/N PROBE 4 SEAIR£ COIJOOMINIUM TERMtNATtON POINT, WASH. '''°"" PAUL R. 11VE8ER orA-oi J.C. nn CONSULTING SOILS EN4NEER ROO rI~fTLJYt[ avG MORTN t 2 P. R.1K g[ATT{,[.wM••q• !•71-01.0 1~,. 1 1 1 1 1 1 1 F' 1 1 1 1 1 1 i 1 CONE BEARING FRICTION RATIO 9b DEPTH CAPACITY (TON/ ft) oe~ ta~v tR fL 1 ! S b !O 70 100 700 •00 O 4 • 17 O 7~ ~o 10 (00 20 so +FO 40 30 30 so 70 r . .,. ,.~ :i- `j~u ~~ ~tt_. Llq ~ ^ -- i ~ A ' ~ _ _ ` - . . ~. . - - - - ~ ~ ~f ~ - _ - - -- i . _-- - .ice - - _ - - - - ~_ ~ i~ -- -- -- ! , --- - - T ' I I ~ ., ,, . ~- +--r _ ~~ SOIL INTERPRETATION TOP ELEVAT70N 75 2 ntos ossus GrC1AL CLT pMrd Zr Lv~r~/ iw~ ~nln. i i 9 DUTCH. CONE LOG PROBE ~ SEAIRE CONOOMItJtUM 'fERNiNA"TiON PANT, WASH. " '"'"'4 PAUL R. WEBER o 9_0- J. G 1p CONSULTING SOILS ENGINEER CNC p k W 7GT'Tl[.M"lI11710! 7ti-01.O a,, ~~ r t W N_ N I.cl W_ N Q Z Q M- N N O ~ ~~ ~ ~~ ~ ~ i .~ Y 1" O d ~ - T ~' ~ ~ N ' O - - - - ~ .!- c ~ ..t_. - - - p ~ - ~ ~ .:. d -- - a _Z .J.. _._ _.a. i ~_ ' C g O Q O ~ O O O O O~ Qf G f~ ~D Q Rf N 1H913h~ A8 b3~Jid 1N3~a3d 0 0 0 o O W Z W ~, W J ~ C ~ ~ o -Z w W _N W N ~ ~ a Z ~ Q C7 z J ~- J<~ a H a ~~ l ~~ 1 V .. ~~ U ~ -...- U ,,; O Q ~ II nn V ~`~. f DWG . rro . 1~ ~. CONE BEARING FRICTION RAT10 96 ~_ -~~ OEPTH CAPACITY (TON/ ft) oEPn+ a.~k FT. ft ~ ~ a re f0 W 100 _~ X00 ~ ~ 0 "'f ~'- ~ ~~~ i 1 1 1 '.. ~~ ~I"" 40 20 -~~-- g0 3O -{ ~- 20 40 30 go ~_ ql ~, DUTCH .CONE LOG SOiI INTERPRETATION Tpp QEVATION ~~ _ LOOM iii OJC[~ dT nwc PROBE ~o SEAIRE CONDONINIU-~1 SERMINAZ~ON POiµT, WASti• '"'"'4 PAUL R• WEBER o 9-0~ z. c. w. coNSU~TUrc sous aaN~ 14 ~~~ ~ ~ P R. W. t[iTTIf.N-M NIOf 2.3-ONO i~ ~~ 1~, 1~ 1 ~~ ~~ i I i I = (REV. •.u~ W N N LJ taJ N 0 Z Q H N N 0 0 0 a 0 V O I O O c~ ~ O ~' '~ i N O ~~ - - - - ~ L- - - - ~ ~ i _ O M o 1 - - - - ~ ~~ ~ Q C ~~ ~ pp O O O O O~ O 0 ~ ~ ~p r7 7 ~ N 1H9I3r~+ ,l8 a3N~~ 1N3~a3d W F- W w J J Z W _N N z Q ~, ~. ~* ., a~. .~~ .4. '° ~ -.` ' t`'~,_ d, M. ~ i. ~ tia. ~F `'~ J '-'z+ ~y5 t,` •\ -~~ -. ~ ~~ ~ ~ /~// 6i. s .F \ 0 . a ~ i ~ ~, ~~ t~ V ~.' -. DWG . NO . f ~. c~ r r .- i W N to l.J _W N 4 O Q H N N 0 0 0 0 ~ p N __.y _ i - ~. - ~ ,~ ... ~ _ . O D Q O d `~ i ~ ~ ~ ~ O N a O •1• ~ - - _ ~ I ~ .~. - - d K c ~ ~ -~ - - - ~ ~ _ .~.. h a - . - . - - M ~ ~ , ~ -.~ ~ C`ri 2~ ~ ~ ~ ~ N 1H9131N J~8 b3Nld 1N3~~l3d N C W H W J Z W N_ N Z_ Q C t7 I'~UL Z.~~~BER ~. ';r ~- ~~ ~` ~ ~. .. `I .~ w ~~ ~ L y ~+ \ ~~ ~ U 3 ~`. y ~if e V `.,, z ~` i~ 0 Q -~ `\l, ~~` ` DWG . NO . -7 t } ~ DEPTH z ' ~ ~ `" STMID4RO PENETRaTION RES ISTANCE oEPT-+ EiEV BORING LOG 1 ~ : ~ 6 0 80 FT. FT• > w a t O y0 40 TOP ELEVATION ~~~ r ~ c ~, O lTfi ~. ~ our -crtus cur cw.rmral ~tw enm . Qaaou ssur 10 woes wr a cow ccaf a vcr rnn t~ aoase crrs- - nsam ifi0 99.7 car e.r. e.+~. Rv Dose 130 wr eun rtioi eum. ~r oorse ! wvct a wscus. rcn owe 30 wr cuvcut ctt.n v ~p e., larcLU. rrul ter . ao~ss 140 4p ' w! /txs WOf tII.T 1~0 wr n~.rn wo vtn c~u+~ f lcuctu. rtu) (~ soup SO 1y0 eoat>•c wvt.cren t/wn~ ~arsc asewl. ~ fo sranc QOUOwra s~os la >o LEGEND: D UNDISTURBED SAMPLE EXTRACTED ® DISTURBED SAb1PLE EXTRACTED p gAMPLE ATTEMPTED BUT LOST ~ SP T BWavs TO DRIVE SAMPLER 12~ O NATURAL WATER CONTENT PLASTIC LIMIT ~LIt3 U 1 D i11+1IT ~Clf 3~' 3WL' ~JS~ 60.4' a~ BORING i SEAIRE GOIdpOilINllYd -ERN1uA'~ION POINT , MIASNIWOTDIJ `-'"" PAUL R. WEBER '°o ~-~1 P.R.N CONSULTING S00.5 ENGNFER -u-51~o. txoo,ecsnwa ~'rORTM ~ fE~trll. rnM fflOf !f1-OV0 O X 20 Y 4v s w~ ••~ S WATER CONTENT ~, [. w DEPTH OEPTN ELEY FT. FT. TOP ELE o -~r ''~ to ~ ~~ ~ 3o w ~o aO so --IF- ~o so -~I-lo 70 LEG END e p UNDISTURBED SAMPLE EXTRACTED ® DISTURBED SAMtPLE E~cTR/,GTEO p SAMPLE ATTEA1PiE0 BUT LOST O SP T BLOWS TO DRIYE SA>APLER 12 O NATURAL WATER FONT EN T ~-PLASTIC lIM1T .~ n ~ ~~A~T STANQARO PENETRATION RESISTANCE ~ 20 40 60 ~ 20 x sox .sox ao x WATER CONTENT BORING 2 SEAIRE CONDOMI1JIUtd TERU~P:~T~oN PouJT, wuHa~ou 2_'-x PAUL R. WEBER '°~e-a P i. W CONSULTING SOILS FNGUVEER •uTa b uoowtsnA,ar+c~TM ~ fE6TRE.rrai.~~MO~ t~)-0U0 f /j J DEP . T H OEPTM ELEV fL Ff. 7DP El! 0 60 10 ~p r 20 40 ' ~ 30 ' ,0 ZO ~•... ' ~ 80 10 ' ~ SO O 70 -IO BO -20 ti0 -30 M BORING I.OG 3 NATION 60 ~ PY'~O~ ~} ~ ~ ~ ~ tuiaN r2trT aam ttaosa - uTwT~e) ij M1Q0 T[RfO2L, i2LTT r2U[ I/JD ~ adT (rOR a SOOL[) yiaT~rrnnnwu i swa aro S,c,n2w (wrr) .0-T a~T O®IYI tT21rI UQJa2i [TI21[~[) awns taro n Lars2es ou - , awt uLT vm smu t~ toss) trasm aateul oat ns: tasu a tiLT? viii iAfm ~; oasis aim Ta rns m ~~ aa~o , souas as~tssn i; W .~ STpNpARp pgNETRATION RESISTANCE i~ a ~~ ~~ < 0 20 •o ao ao j lA e7 4 98d ~.o ~ 81.5 G9.1 O 10 20 30 • • S 6 TO • 80 ~ S ^ ($ i~ I® I® bh• ~f ay~• .i ~ ~ ~ ' " DEPTH y ~ W ~~ ELEV BORING LOG 4 ~ ~ ? sTa~IoaRO PENETRATION RESISTANCE FT. fT. ~ r '" t O 20 40 60 80 TOP ELEVATION G7 ! ¢ ~ a+ ' O 67 ~ arwt ~ ~w ~atm tart tao aim tum a asr rtTt • ~ aunt wIS*t cwT) ' 10 ' WT CiJT (1®201 fn17 ' nttoaaal ttrvt zo aw ~ n taut) a0 1 1 ~ 1 1 1 ~ ~ •~ b ' so t9 K~TIC 000afYlrat Lai O .. 'o OZ 6 9z.g e i ri ~ LEG ENa: O UNDISTURBED bAMPLE EXTRACTED ' ® DISTURBED SAMPLE EXTRACTEQ O SAMPLE ATTEMPTED BUT 1057 ~ SP T BtCw3 TO DRIVC SAi/PLJFR 12` ' O NATUROL WATER CONTENT ter-PLASTIC LIMIT '~" `Lla u t O LtMR • ., O X 20'J< 40 !L 60'x 80 x WATER CONTENT BORING 4 $EAiRE CONOOMI-JIUM TERMINATtCN DOINT,wASNwGTON '4 PAUL R WEBER ';~:° Paw . C1 CONSULTING SOBS ENGWEER tt00 M€iTtA1Q w[ wo11tN ru-Tt to. / . scarTU.,rsKSSas :~a.olto ~... ~I, `. DEPTH DEPT" ELEV 60R I N G LOG 4 FT. FT. TOP ELE VA TION G7 = O 6 7 --------__ mr ~ uw ~ tttzt rrao am •a+m ~ nor rrn o~rrrsc ~t:s (qt1 to WT CL! (MDIU1 [TI11 ~ n~sa~l Isrsn :o aw n safnl 20 m~rro n~° n~C" ~ ~~ ~ ~OIIk ~ 2/S/It to K~ZrC OO~WIQ rApi Air •O > \ N " W Z ~ ~ STANOARO PENETRATION RESISTANCE ~„ n r ~ t 0 20 40 60 80 Q • N O ~ G ® . 02 6 ~ ~ 20 9z.g s ®. ~~ LEG END: O UNDISTURBED SAMPLE EXTRACTED ® DISTURBED SAI,APLE EXTR/~TED O SAMPLE ATTEMPTED BUT 1057 O SP T BLOW'S TO DRIVE SAMPLER 12~ O NATURAL WATER CONTENT PLASTK LIMIT ~, ,nu1D lIM(T ~~ .. O % 20 % 40 % 60 % 80 Z WATER CONTENT BORING 4 SE:AIRE CONOOMIIJIUM TERMiNA'7iCN POINT ,wASMwta'TdJ 74 P WEBER PAUL R ~:'. o~ 4w . CONSULTING 500.5 ENGWEER runt ro. noo wcsnA,a we notrn / fUT7tt.w~fK •f,Of tff.4f0 ELEVATION IN FEET 0 0 $ 8 $ $ ~ 8 6 $ U1 € _ m _ ~ ,~ o ~, ~ ~ ~~ ~. ' D I ' - / - /! ~ . I ~ o_ 1 "~ / I ,% i ~~ a; ~~~~~ .> z~ ~ ~ .t; n " n ti $ 1 i~ I A O V m n yM1 ~ r I/x ~ a l A o .~ ~I N _. . ._ m ~ z ' , o W I O ~ ~ 0 m D a - m w -' m ]7 I •V N N ' ~ ~~ m v I~ ,I .j -;~ i~ ~~I I U~~ .~J'.._ . r' i Xl rn T rngN-I r~p~ `>m~ D; n v "'i~ v I u ~Z< x n C`~ OS~ ~r ~. r O n ~ ~~ o~~ i _. Z ~ s w ~ "T i~! r~ fiD ~ j 1' L ^~ ~~Iq N ~ } ~ 'r ~~ ~ L f D C O r $~ ~z,,~ nip t~~ wm a~ ~~ ~ ~ > ~~ ~' ~~ x I . ,moo ~ o y~°Z ~ oC { ZO~p I aU li ~~~Q ELEVATION IN FEET ~ ~a~~ ! / o W ~ ui rN o ~ - - - $ o ~ 8 0 $ S ~ LLI ' . r ~ , I , ~ i. -~---- - -1-----~--- ---, - 1 ~ ~ n~ i ~ ~ +- . . _ ~ ~ I , ..~.~~ ~ . ! o ; , Z ~ .... _ .. . ., ~ i I F __ O.I i '. ~ .. __._.. __T ....___. _ _.~ _ / I ____. ,. d , i rfn 1/ t / .I / • _ ' ~ ~ . . y ~ I ,~ ~ .... ~ - i I ° ~ ~ i~, _ I ~ I I ,~ W, i ~ / ' 1 ' ... . D - y in _ - g • ft ~' e o~ n m~ O ~ 0 .~. ~~'t'- . ~ +~<t , ~ ~r ~ v N 4 ,~ ' , ~ ~ Z ! ~ ~ m A n , 1 ~' ~ ~ r ~ ~~' D { i .. .. ~ -'-- - . _ _ -r~ ~~ _ -i . ~ ~ j .~ i ~I ~~• _ ~ ~` ,~ri{ to' W A l1 ~H I n -m ~ ~ . ~ ~ e ~.>1 '• y ' ~ k X ~~ I~ '' y; n. °~ ~' O ~ ' ~ ~y i to ~I d ~ I w x ; S X ~, W ~ "~ ~ ,y V - ~ ~/ ~ ~ ~ .~ _~ ~~ N ~yz X i ~-. ~ ..._ u Wy, R iq ~ z ~ '/ W _ ,/,/~ Z / N '' r ~, c9 g m ~ S N 1334 IVI NOIl'dn3~3 Q 0 N U U z I"' U w 0 ' OPE STABILITY REVIEW OF POPE RESOURCES PROPERTY SL between Paradise Bap Road and Aood Canal. INTRODUCTION ' based on extensive field examinations, review This report is of available literature (see references), and examination of ' aerial photography flown in 1942, 1965, 1976, 1977, 1979 and 1985. The work was conducted in the contest of a pofSOthe acquaintance with. the geology and slope stability Termination Point area acquired during the period since 1974. SUMMARY ~~ The shoreline bluff north of Termination Point is, as the ~~~ enerall unstable. Actually, (~ Coastal Zone Atlas indicates, g p recent slides (Urs) on the bluff face are more abundant than the ~'~ Atlas indicates, but they are too small to show accurately at the map scale. Such small and superficial slides have probably been shaping the bluff face for thousands of pears. Thus, the Atlas designation "Uos" (unstable, old slide) for the rest of The bluff is also accurate in a sense, but a little misleading. here is not an old slide, but it is an old slide area. This distinction pis important because .the portion of the Po a site designated Uos on the Atlas is not a single large P ancient deep-seated slide mass that has moved as a unit and could reactivate as one. Thus, it is unlike the areas designated "Urs" (unstable, recent slide) southwest of Termination Point and along the north side of Thorndyke Bap, in ways other than the recency of movement. The Termination Point slide. is a large ' gently sloping landslide mass near beach level. The Thornda~~ Bay slide is a large landslide mass on a midbluff bench. In p because of their relatively gentle slopes, both slide masses have had attempts within the. past 15 years-or-so to develope permanent residential communities. Both slide masses have reactivated within that time span. 1 The bluff at the Pope site apparently. does not include large deep-seated slide masses poised for reactivation. Instead, it is a steep ice-compacted upper bluff fronted by the debris of laces, the weathering and many very small landslides. In a Seated landslide topography suggests the site of an ancient deePerosion, only the where the mass has long since been removed by it is ' E ually important, site of its origin remaining. q in any understood that Pope Resources has no intention of dearsoto be no part of the shoreline bluff itself. Thus, there app geologic reason why the upland surface of this site COreasonabbe safely developed for residential use, assuming setbacks. 1 .. II~~ IJ ~~ '~~ i Ir-, hI ~'~ i DISCUSSION General The Pope Resources property between the Paradise Bay Road and Hood Canal consists, in general, of two basic types of terrane, agently rolling upland and a steep shoreline bluff. Judging from Limited exposures, both terranes are underlain by silt, silty sand, and gravelly silt or clay. these materials have been compacted by the last continental. glaciation, with ice well in excess of 3000 feet thick in this area. Thus, the underlying sediments are not only hard but quite impermeable. Upon retreat of the ice sheet the area was subjected to a variety of erosional mechanisms, some no longer functioning. For example, the landscape, essentially barren for a while, was subjected to periods of climate quite different. from today's. During the 13,000-or-so years since the ice left, there have been times significantly wetter than today's climate. Combinations of these factors probably account for the erosion of broad V-shaped draws in the glaciated uplands at the site as well as elsewhere in Jefferson County, draws that no longer contain even intermittent streams. Such factors may also be responsible for landslide-like scarps with no associated landslide deposits, such as occur along the north end of the site. The post-glacial processes of weathering, mainly freeze/thaw and wetting/drying cycles and stream and wave action,. have produced a variety of slopes and soils upon the ice-compacted parent material. On the. uplands such soils are in the form of root-loosened and weathered silt and silty sand, more or less in its original site of deposition. On the bluff faces weathering is not in place, .but Itss th ic~nessv ran desnfromenon-existent on processes and gravity. ' g near-vertical upper slopes and recent avaianche;PVQis Theseobluff ~ ~ eyr the beach ten-or-more feet thick ocalyy r. face soils present the main slope stability cor.cerr. at t.:'s sir?, Shoreline bluffs Since pre old-growth times, and possibly for thousands of years, landslide action at the site has apparently been confined to the immediate bluff face. These slides have been inear Ito obe of small debris avalanches and slump/flows.. They aPp They rarely more than S-to=10 yards wide and 1-to-3 yardsedebluff to commonly extend from the base of the near-vertical upp and onto the at houses or otherestructurea along the. basedof the hazard to a bo bluff . ii ' These slides robably ar_e triggered by shallow groundwater P concentrated on the i;apermeable in-place silt underl;~ing the colluvial soil. In a fe:J places they map have been triggered by soil and debris fall from the top of the bluff. Generally, the;r occur below broad draws in the upper bluff but in some places ' they have occurred on steep, relatively plannar, slopes. One or two small slumps have occurred at beach level on the site. These are due primarily to long term undercutting of the toe of the ' slopes by wave action. ?tiave action is, however, not an important initiator of slide action here. Ice-compacted cohesive sediments such as make up much of the ' site commonly have cracks paralleling the bluff face. None could be seen at this site, but this may largely be due to the dense vegetation. Assuming that such cracks exist in places, .they are seldom a serious slope stability problem. For example, such ' cracks have existed for decades in the bluffs near the ferry terminal in Port Townsend. When a section of bluff made up of such sediments does eventually slab off, it is seldom more than a ' few feet at one time. Thus, while there could be rare and isolated hazards below from falling or rolling blocks of soil, there is little effect on the upland surface. ' Glaciated uplands The upland surface, between the bluff and the Paradise Bay ' Road, shows ample vegetative evidence of poor drainage. Patches of swamp grass, tussock clumps, .and. even cattail can be found throughout much of the site. Such areas indicate perennial ' shallow groundwater. Thus, they could cumulatively be a small but significant source of deep ground-water recharge, in spite of the low permeability of the soils. Such recharge .could, in places, be migrating laterally towards the bluff and contributing ' to the locallized instability. ' Slope stability Drainfields can be a source of ground-,~ater recharge and thus have a small but potentially significant impact on slope ' stability. At least three factors tend to mitigate this effect at the site. First, the low density of development proposed would limit the recharge potential from this source. Second, the low permeability of the natural soils would tend to slow any such ' recharge. Third, the relatively low precipitation at the site would tend to result in an increase in evaporation and evapotranspiration on and near the "mound system" drainfields. ' In general, low density residential development should not have as great a hydrologic impact on slope stability as clear cut ' logging. The uplands, and at least .some of the bluff face was logged long ago, probably in the early 1900x. The earliest available aerial photography (August 1942) shows a well ' and growth forest. at the site. The only evidence established sec o of instability apparent from that photography is shallow linear debris avalanching, just as has occurred in recent years. The apparently took piac° last logging, this time onl;~ the uplands, - in the late '70s. No evidence was found t:~~at either 1ogg~ng ' event had an impact on bluff stability. Particular attention was paid during this investigation to the shape and orientation of the older conifers. (Alder, maple ' and madrona are not reliable indicators of slope movement as they rarely grow straight.) In general conifers were straight. However, near the south end of the property, where slopes face south easterly, slight northerly leans or sweeps were common. As ' these diminish as one progresses uphill and inlandrevailin~ concluded that they were a response to the strong p o southerly winds up the Canal rather than to any slide movement. ' he area south of lot number one needs a Nevertheless, t closer look should development be eventualmapp dtthPsaareafas ' this particular area. Hanson (1970, 1977) Class 3 ("inferred to be unstable") in her thesis and it is shown as "U" (unstable) in the Atlas. Some topographic suggestions of old slide activity were r_oted during this study although, similar ' to an area along the north property boundary, no evidence of a remaining slide mass was detected. There were, however, more random directions of -lean and sweep of the scattered 2 to 3 foot ' fir here than further inland. The abundance of blow-downs in this vicinity again suggest that this could be more a result of severe winds than slope instability. RECOMMENDATIONS Should Jefferson County agree to exclude th~so tant that development restrictions (Resolution b9-83) it is p of these any resulting development recogn_ze the sensitiv~ty~V ~o~rlar-" 1 ~ th rou~cu- i- 1 i l gt r~1 'D ll~~ o _ _ ~-o- ShOrelne blu_iS. 1-- 1' eroQ=~. ~1 nee' ' are the end result. of erosion and are sti attention to their particular site characteristics in order to prevent or mitigate development impacts. The following. recommendations are based on or rellvnot adverselylimpactdpresent ' help to ensure that development wi slope stability conditions. ' 1. Construction setbacks: The bluff/upland boundary is quite sinuous along much of the property and erosional processes have, in places, made its locotion rather arbitary. That ' eolo is variability suggests factor plus topographic and g g~ that builders desiring a less-than-conservatsitesbassk will need to deal with the question on a site-by- ~~ 1~ ~l 2. Land clearing: Builders and homeowners snouid minimize the disturbance of soils and vegetation. Lot "scalping", in ' areas such as this with relatively impermeable soils and 10~~ precipitation, could make revegetation difficult. (Under no circumstances should land clearing debris be bulldozed over ' the bluff.) Tough, deep rooting, evergreen species such as madrona should be encouraged. ' 3. Drainage: enhanced. groundwat including ' carefully conducted Present upland drainage should be maintained or Unlined impoundments or ponds that could recharge er should be discouraged. Surface runoff, storm drainage from improvements, should be either dispersed or, where practical, collected and to beach level in water-tight flexible lines. 4. Beach access: Access systems for some sections of the bluff would be expensive, potentially hazardous, or environmentally unsound; whereas for other sections, could be quite practical. A few carefully selected community ' corridors might be considered as an option to a lot-by-lot approach for beach access.. Any such access systems should be carefully laid out to take advantage of relatively stable ' bluff segments and designed to .minimize disturbance of vegetation and soils. 5. Lower bluff/beach improvements: Permanent improvements in ' these areas, such as boat houses, cabins or bulkheads should be discouraged or at least be small and "disposable". In many places they could be damaged by small debris avalanches ' form above, on-site slumps triggered by excavation, or by falling trees. In general, beach erosion is slow and predictable, with wave protection offered both by Hood Head and the floating bridge. .Any bulkheads yr retaining ' structures should be carefully engineered, probably requiring more attention to soil pressures than. to wave action. ~~ GERALD W.- THOR~~" ~ '•G• ~~ ~ . 3325 ~~~_ r1~Ca 1 ~ _~~'~ ~ ~~ ~'-`~ ~FCSS~a"-"`~~ REFEREYCES Hanson, K.L., 1976, Slope stability map of the Uncas-Port Ludlow area Jefferson County, Washington: Washington Division of Geology and Earth Resources, Open-file report 76-I'8 Hanson, K.L., 1977, The Quaternary and environmental geology of the Uncas-Port Ludlow area, Jefferson County, Washington: Washington State Department of Ecology, 1978, Coastal zone atlas of Washington: vol. 11, Jefferson. County. ,. _~~ i ,~~~. NORTN~tIESTERN TERRiTaRiES, iNC. K Engmee!s ^ Land $urvpynrs ~ Planners Cnnsrrt,conn Conrdrnalrnn ^ A4arerrals Testing ~~~ - CV~. assaa•rs PRELIM=NARY F=ND=NG S FROM A GEOLOG=CAL RECONNA=SSANCE OF THE TERM=NAT=ON PO=NT AREA JEFFERSON CO'i.TN~~'`~ ~ WASH=NGTON Prepared for MR. PHIL CANTER Prepared by NORTHWESTERN TERRITORIES, INC. November, 1990 71? SOUTH PEABOOY, PORT ANGELES, WA 98362 (206),452.8497 1-800.654-5545 ',' PRELIMSN~IRY F=NI7=NGS FROM A GEOLOGICAL RECONNAISSANCE OF THE TERMINATION POINT AREA JEFFERSON COUNTY, WASHINGTON ' GENERAL ' At the request of Mr. Phil Canter, Project Manager, a geological field reconnaissance was performed on November 2, 1990, of a proposed property development site located at Termination Point on the west shoreline of Hood Canal, about one half mile south- west of the Hood Canal-Bridge. (Section 2, Township 27 North, Range 1 East). The coastal zone within the south portion of this 24 acre parcel has been identified in the Coastal Zone Atlas. bf ' Washington as.having "critically trigtable slopes". (See Enclo- sure) Points of contact at the property site were Mr. Phil Canter, Project Manager for ahe firm'bf McCormick & Canter North- ' west, and Mark Kuhlman of Pac-Tech Engineering, Inc. Mr. Can- ter's firm is a prospective purchaser of this property, pending the results of various engineering and geological studies. PROPERTY SITE DESCRIPTION ' The enclosed map shows a plat of the subject property with three access roads and associated subdivisions into individual lots.. This property is bounded on the north by Shine Road and the ter- ' rain then slopes southward at an average slope of around ten degrees to the Hovd Canal shoreline, a distance of around 1,200 feet. i SITE GEOLOGY The northern or higher elevations of the property are underlain by sandy soils which outcrop near the surface. However, with depth, and throughout the lower elevations and. coastal areas, prevailing underlying soil unit consists of a compact silt forma- tion with some interstitial clay content. It is this cohesive but weak soil stratum, combined with poor drainage and associated steeply sloping terrain near the coast line, that has given rise tv massive land slides which characterize all of the south coast- al portions of this property. These slides are in the form of massive slump blocks of up to several hundred tons each which have slid down and away form an escarpment, carrying nearly undisturbed and intact portions of the forest cover with them. A very approximate "line of demarcation" ha ' enclosed property map along the top of the ment. In the simplest terms, all the land escarpment line has been severely affected s been sketched on the above described esarp- to the south of this by typical landslide 1 topography, such as poor drainage and extremely variable founds- ' tion conditions. All land to the north of this demarcation line is for the must part free from the adverse effects of slides, but does suffer somewhat from poor surface drainage. ' PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS 1. A land survey is needed to accurately determine in the field the precise location of the "line of demarcation" between slide and non slide topogra- phy which is presently only approximately indicat- ed on the enclosed map. ' 2. This survey should also :construct a topographic map df the entire property~`s;ite north of the "line of demarcation" in order to-.~ac,ilitate the design •:. of an effective 'surface drainage system, which utilizes natural drainage features whenever possi- ble. ' 3. The land and soil conditions north of the line of demarcation should present nv unusual problems for the construction of homes utilizing standard foundations (e.g. soil bearing 2,500 lbs per sq. ' foot). However, for long term stability and safety, a set back distance on the order of 125 feet northward from the line of demarcation is ' recommended for all permanent homes. 4. A limited number of homes constructed upon spe- cially designed foundations such as piling might be considered in selected land slide areas below, (south of ), the line of demarcation. The unusual- r ly poor surface drainage existing throughout this general area crould~require substantial improve- ' ments, and all wooden structures constructed on shallow piling, (15 feet +/-), would be preferred ' over any type of masonry building. Some type of disclosure statement should also seem to be appropriate for any prospective buyer of properties south of the demarcation line in .order ' to apprise them of the land slide origin of this property and its corresponding need for special ' construction alternatives. 5. The massive slide blocks of soil comprising much of the shoreline area south of the demarcation line ' are probably now in a state of near equilibrium, having .come to rest from a higher elevation. However, the shoreline area itself is in an active state of marine erosion and can again destabilize these slide blocks which are adjacent to or near the present wave cut escarpment at the shoreline. (See photographs) Consequently, any specially ' designed home structures which are less than 150 feet of the existing shoreline may eventually be threatened. 6. Some thought may want to be given to the construe- tion of a low (six foot high +/-) rock sea wall along all or selected portions of the coast line to minimize ,erosion and associated escarpment retreat, which is estimated to average about six inches to twelve inches per year in this unpro- ' tected area. 7. Preservation of as many trees and vegetation cover ~.,as possible is strongly recommended. to help slow ' down the erosion process, particularly an steeply sloping ground. STANDARD DISCLOSURE STATEMENT This report is based on a visual inspection of the existing site conditions and/or facility. No scientific measurement, tests, or calculations were performed. The findings and report are limited to the normal standard of care of the industry for an investiga-. tion without benefit of scientific data and calculations. Unless foundations plans •are reviewed and the construction work is inspected by the Engineer, no warranty is made by the Engineer concerning conformity of the construction to the conclusions and recommendations of this report. woe.,eQa~Qee ~E~R Y ~~Fiy~•~ o .• ~ Y~aS~, '•.• ~y ~ e° ~~: ti~° ~~~~'c = • Norman A. Dixon, PEG • t~` 'y`~ / ~ Engineering Geologist ~ `,. _,d 0 1:5? O .~~. r ~ o 0 1$Tc.R ~; ~4, • .'~ .. ~Y. 0 . ft'C! . c~ ~~ o o =.Q.•~:~' J . R. Jerry Newlin, PE c L?, ~,.1 e~o~~edd"`~Q Principal Engineer r- ~ f fc: Canter.Nov ' Dir: JRN/Rpt it ~~ Photographs showing active marine erosion occurring along .the wave cut escarpment near the high tide zone at the extreme. south portion of the Termination Point ,property. A six foot high rock sea wall constr.~cted along the toe off the wave cut bank would substantially reduce the shoreline erosion process in this area. ~~~ 0 n ~~ ~~ May 10, 1996 Mr. Russell .I. Trask 13550 Sunrise Drive Bainbridge Island, WA 98110 Job 299 RF.: Geotechnical Evaluation of the Termination Point Subdivision located in a Portion of Section 2, Township 27 North, Range 1 East , W.M., Jefferson County, WA. Dear Mr. Trask: With your authorization and as directed by your agent, Ms. Barbara Blowers, a geotechnical evaluation was made of the subject parcel. It is my understanding, that due to the unstable slope classification made on the area by the publication of the Coastal Atlas of Washington, Department of Ecology, that in 1983, Jefferson County imposed building restrictions on the subject parcel in the Termination Point Area. Then, later geologic reports by both geologic consultants and state geologists appeared to confirm the unstable slope classification. The function of my evaluation is to determine if the unstable classifications are truly justified and to also determine what measures could be taken to improve stability. The field phase of my evaluation was done over a period of two days, April 9, 1996 and May 3, 1996. The field work, consisted of making a reconnaissance over the subject tract plus adjacent property of outcrops, attitude of conifer trees, drainage, topography as related to slope stability, the placing of five backhoe trenches to .obtain subsurface data, and took three undisturbed samples for secondary testing. Photographs and video pictures were taken to document field conditions. In addition to the field work, review was also made of the following: (1) Coastal Zone Atlas of Washington, volume 11, .lefferson County, Department of Ecology, 1978, (2) Soil Survey of Jefferson County Area, Washington, Soil Conservation Service, USDA, 1975, (3) Letter to .Jeff Stewart from Hugh Shipman, Washington Department of Ecology, Termination Point: Trask 1200' bulkhead proposal, August 1995, (4) a series of private consultants reports on the Trask property in addition to adjacent properties, (5) Jefferson County Resolution No.69-83, Termination Point Slide Area, Restriction on Development Activity, dated July 1983, and a (6) Topographic Survey of the Termination Point Subdivision as prepared by Pac-Tech Engineering, Inc., .Iuly 199.5. Also review was made of a series of aerial photographs dated 1965, 1972, and l 990. C~~ ~CO~~ ~ G~~.~.OCf.QfE~. Cieotec~Znlca~C'orz su~tants 360 ~'~~esE gt~Z ~tzeet - ~nacoates ~'V~ gL~22i `~e~e~~ZOne (360) 293-boq~ `~az (360) 293-6o~q '1 [l 1 i~ Mr. Russell J. Trask May l0, 1996 -2- As shown on the Coastal Atlas Slope Stability Classification Map of the Termination Point Area, the entire lower half of the tract is shown as being .within a Very Critical Area and is classed as Urs (unstable Recent Slides). However, based on my observations and conclusions, while it is quite obvious that sometime in the past, at least several hundred years ago, a slope stability problem did exist in the upper portion of the parcel. However, I saw no evidence that any slope stability problems other than minor ravel and surface slumping now exists in the upper portion of the parcel. Furthermore, with improved drainage (both surface and subsurface along with placement of an energy dissipating medium or structure along the toe area (shore line), 1 feel that the factor of safety can be greatly improved and except for a major seismic event, the entire parcel will be stable including the shoreline toe area. Since there are now areas along the shore line currently showing unstable conditions, it has suggested to some, that the rather bold expression of the "scarp" like features also indicates current sliding in the upper portion of the parcel. This is what needs to be discussed, because I came to the same conclusion when I first inspected the site. However, now in my opinion, the "scarp" like features while they might have been associated with a past slope failures, are now more the result of erosion by both water and weathering. If active sliding was now taking place, then the trees would confirm that condition and bulking of the toe area would be quite obvious. None of these features were observed. [n regard to the suggestion that the area has undergone movement by either a deep large arc failure or very large block slide, direct and indirect evidence also does not confirm those types of failures. Also, the long continuous "head scarp" type feature, does not fit in with what is typically found in either a rotational or block failure. To get a better grasp on what had actually happened, I prepared four cross-section profiles across the lower two-thirds of the tract. These sections, by their topographic expressions and what I had observed in the toe area, at first appeared to confirm that a large and rather deep combination rotational-block failure had taken place. 1 then considered running a computer analysis (P('STABL) of the slope, using what is called a "back analysis" method to obtain "reasonable" input values. However, 1 felt that not enough .firm data was available to even use the "back analvsis" method. Without the availability of firm data, 1 would simply create what I had already assumed. At a later date, when more firm data is available such as from one or two drill holes, 1 propose to make such an analysis. Then the results of the analysis will not be so dependent on my assumptions and I am quite sure that the results will show that only very shallow sliding has occurred. Mr. Russell J. Trask May 10,1996 ' -3- However, at the present time one factor does indicate that a deep slide did not occur. You will note in Attachment 3, that certain beds (hatched) are shown in all of the cross-sections. Because of the relatively low strength of these beds, they would be expected to be associated with any sliding (especially along the failure plane) that would occur in that formation or along the contact with an overlying formation. Also these beds arc only found in the one formation, and that formation is present ' only below elevation 100 feet. This is important, since beds are present in what would be the down drop portion of the slide, then these same beds would indicate only a vertical drop of about 20 feet and thus suggest a rather shallow slide and not a deep. block type failure. What is meant by this is shown below in Figure I. ~ q vf, .. ,.e _ _ _ __ _ _ _ ~ ~_ .. ~ i ~ /1/_._ ,j / ~ P1r 1 Figure 1 -Reconstruction of slope if deep sliding occurred. Also, because the attitude of the conifer trees, unless the slide or slides were relatively old and had not moved for at least 125 years, then all of the older trees, along the toe area of the slide or slides, would be leaning back toward the slope. But only a few trees, and at scattered locations, were .found to be leaning back. In reality, many more trees were seen to be leaning forward, which is normal for trees on sloping ground. Therefore, based on the data just discussed, I question the scope of the unstable conditions as offered by others. Another factor to be considered is that this past winter (1995-1996) was a period considered by many as the "winter of the hundred ' year storm" with resulting extremely heavy and prolonged rainfall with many slope failures all over the north Puget Sound area. Yet the Termination Point area (within the limits of the study area) except for shoreline erosion with normal related. i 1 1 Mr. Russell J. Trask May 10, 1996 -4- minor slumping and also only ravel in the scarp slopes in the higher elevations, did not show anv current failure conditions. "Then to expand beyond last winter, except for normal shore line erosion with associated bluff toe failures and normal excess ravel and/or minor slumping in the near vertical slopes that exist at many locations in the tract and some evidence of recent debris Flows, no recent slope failure conditions were noted anywhere on the tract. The geology within the limits of the tract and as indicated in the Coastal Atlas, consists of Quaternary Pre-Fraser nonglacial sediments (Qpf) exposed from high tide line to about elevation lOQ feet. These sediments consist of near horizontal beds of sand and gravel, but in places silt, clay, and peat. These beds appear both in color and physical properties to be similar to the Whidbey formation. The Whidbey formation is rather notorious for being associated with landslides in the northern portion of the Puget Sound. Then overlying the Qpf sediments is younger Vashon lodgement till (Qvtl) and consists of a compact mix of boulders, cobbles, pebbles, and sand-silt. At least three rather thick zones or beds of clayey silt in the Qpf sediments, were detected during my reconnaissance. Other thinner beds of clayey silt may also exist. The lower bed (#1) is located along the high tide line. It outcrops just above the high tide line at the east edge of the property and then both above and below the high tide line in the middle of the parcel. The second bed (#Z) is cncountcreci at about elevation 50 feet, and if a rotational or block slide had occurred, that bed would then be in the down drop section of the slide. This bed was encountered in backhoe trenches #4 and #S. The upper bed, seen in a road cut near the eastern edge of the tract, was encountered at about elevation 75 to 80. Because of the rather high clay content and the strongly fissured condition of the beds, it is a good "marker" bed. I classed it as a well consolidated clayey silt with minor sand. Bedding of this material is mostly near horizontal to having a very shallow dip toward the northwest. However, in places the bedding is chaotic and shows intense folding. Because of the clay content, the permeability of this material is quite low and it acts as an impervious layer, which results in perched water accumulating along and above the contact zone. This then results in an increase in pore water pressure which then can reduce stability. Also the perched water will Flow laterally and until it can discharge out to the surface. Exposures were noted along the shore line where many seeps and springs were discharging out at the. contact between the clayey silt and the overlying more permeable beds of glacial till and silty sand. The combination of both seepage out of the slope and active wave erosion has resulted in a rather rapid rate of erosion 1 1 Mr. Russell J. Trask May 10, 1996 -5- landward. The aerial photographs confirm the rather steady rate of erosion that has been taking place, by showing a structure located some distance back from 'the shore in 1965, then less in 1972, and then in 1990 of being right at the shoreline. When l inspected the site in April 1996, the structure .had been destroyed. It seems quite obvious that placement of rip rap or some energy dissipating medium and then the interception and removal of the perched ground water would do much toward reducing or arresting the erosion along the shore line and would then also increase the safety factor for the entire slope. On first inspection of the parcel, it is no wonder that it was classed as being unstable. About mid-way up the parcel at about elevation 125 to 175 feet, a very steep "head ,~ scarp like feature crosses the parcel. The scarp feature continues for some distance both to the east and west. Then a lower, a moderately steep scarp is present at about elevation 50 to 60 feet, which also continues for some distance both to the east and west. Then a low scarp exists just above the high tide line. This scarp is showing recent slumping as erosion is removing toe material. At isolated locations and within limited surface areas along the elevation 50 to 60 feet scarp zone, only a limited number of trees ranging in age from. SO to 100 years, show a history of arc or rotational ground movement. In addition, as a result of logging in the early 1970's, many low areas were created and it appears that surface drainage was modified in places. All of this resulted in "rumpled" topography, such as would be formed in an unstable area by rotational movement and "bulking" of material I strongly suspect that the logging done in the early 1970's was a major contributor toward the more recent unstable conditions, such as excessive erosion encountered in the upper elevations. In the upper portion of the tract (along Linda View Drive) surface drainage has been modified. Also excessive erosion, in the form of ruts in the face of the upper steep scarp, were noted. One backhoe trench (Trench #1) down slope of the upper scarp zone, encountered material that suggests "debris flow" type deposition. No evidence of rotational or wedge and/or slab type failure was noted. I might state again, that the conifer trees that did show a past slope failure condition were in rather small groups and not along the entire reach of what would be considered a toe area. That condition is what suggests to me, at least in the past hundred years, that the only shallow or minor slumps occurred and that they were quite limited in surface area. The four geologic cross-section profiles were prepared in an effort to explain the presence of the scarp zones. These profiles also helped direct the placement of backhoe trenches and select sample sites at locations that were considered critical if shallow arc or slab type failures existed. Three undisturbed samples were taken by Mr. Russell J. Trask May l0, 1996 -6- means of a drop hammer type Shelby tube sampler. However, only two samples r were subjected to unconfined compression testing (the third sample obviously being higher in cohesion and shear values, was not tested). Sample #2 was taken out of what I considered was a failure zone or zone. of weakness. Wave erosion was actively eroding the toe of the slope below the sampled zone while the overlying more competent material above the sampled zone, showed a slight amount of "over hang" horizontal movement toward the shore. Yet, the "Qu" value exceeded 1 ' TSF, which I consider as good. This would indicate a cohesion value of over 1000 psf. Sample #3, was from the middle clayey silt zone. This zone, if it was not within a down drop section, was projected to be along the most likely zone for failure for any slab or block type movement related to the upper scarp feature. This sample had an even better "(2u" of 2.6 TSF. Based on these data and. the results of my slope stability analysis, I began to look for an alternate explanation for the obvious ' slope stability problems of both the past and the present. As stated before, I strongly suspect that the logging in the early 1970's was and is still a major contributor toward the current problem. Prior to logging, except in the rather rare occasions during an extremely heavy rain, because of the forest floor 1 cover and the dense growth of vegetation, runoff in the form of sheet flow or concentrated flow did not occur. With the removal of both vegetation and the forest floor material being disturbed, especially on steep ground, concentrated flow with erosion started. :1t the present time, part of the concentrated flow along Linda View Drive, is diverted and flows down toward and then down the face of the upper scarp. The flow must be enough during the summer months to keep moisture conditions high, since wetland vegetation exists along the trace of the drainage course. This flow, while mostly surface flow, does introduce water into the subsurface for an extended period of time of the year. The moisture weeps that 1 saw at various locations on the upper scarp most likely are derived from such a source. The freezing and thawing of moist zones in the scarp face then results in thin sheets or wedges of the glacial till to fail or ravel. This type failure can result in forming or ' maintain very steep slopes. The low areas formed during logging or the areas where top soil was graded or removed by logging activity along with later erosion with additional removal of soil, results in greater infiltration of water into the subsurface. Without the heavy vegetation growth to absorb and use this water, it then percolates downward until it starts to form a perched water table on an impervious layer at depth.. Pore water pressures increase, resulting in lower shear values and a buoyant effect. During periods of rain with some zones already saturated and having zero or low cohesion can then result in debris flows with the resulting movement of large volumes of loose ~J i, Russell J. Trask May 10,1996 M r. -7- ' come unbalanced, then shallow slumps or arc failures result. soil. Once slopes be Then once failures start, ultimate strength values are reduced to residual strength values (usually about a 25 to 30% reduction), so slopes that had been stable for years are now vulnerable. While I have indicated that my analysis suggests that the tract appears not located in an area of an active large deep landslide, problems do exist at some locations within the tract. These will require detailed individual analysis and recommendations, if needed, of all lots located below Linda View Drive. As an example, the SO to 90 foot proposed movement northward of a portion of Ricky Beach Drive will result in an improvement of stability conditions and improve the usability of the waterfront lots. ' 1 might point out that Linda View Drive has been present since the early 1960's without any known failures. In other areas, over steep slopes and surface drainage has to be improved or corrected. However, in this report I am only going to make general recommendations. However, these recommendations should be implemented as soon as possible. _ ' RECOMMENDATIONS 1 -All depressions and low areas should be filled and sloped to drain. No water ' should be allowed to pond. 2 - Filter curtains with associated drains should be located at points to collect ' and/or intercept surface and subsurface flow. These collected flows should be put into "tight lines"and then be discharged at the high tide line. 3 - In the lower portion of the tract surface water flows should be collected and put into culverts and discharged at the high tide line.. 4 -Some medium capable of dissipating energy, should be placed along the shore, especially in areas undergoing excessive wave erosion and/or bank failure. ' _5 - In all bare areas, plant vegetation as recommended in the following publications by the Washington Department of Ecology. (1) Vegetation Management: A Guide for Puget Sound Bluff Property Owners, Publication 93-31, (2) Slope Stabilization and Erosion Control Using Vegetation, Publication 93-30. 6 -When cutting brush, cutting timber,' or regrading (such as fill low areas and ' sloping to drain), never throw brush or cuttings down any slope. This material will help unbalance the slope because of weight. Also, upon decomposition of the organic Mr. Russell J. Trask -8- May 10, 1996 material, a weak acid can form which will attack any carbonate cementing agent, if any is present, in the formation material Sincerely, James B. Scott, P.F. ATTACHMENTS ExPiRES ~ ~i7 Attachment l -Plan view showing backhoe, sample sites, and cross-section lines. Attachment 2 -Plan view showing areas with trees leaning up slope and areas where low areas need to be backfilled and sloped to drain. Attachment 3-Cross-sections A-A', B-B', C-C' and D-D'. Attachment 4 - Laboratory test results. I w - ~ •~ a W !~ or ~ q: 8 ^. 2~ o ~~ ~z ®_ TR~rcN a Svir+O/` ~is/C /'II` /` C ~ h~ s ee / • l5.3Z' • /30" • 6.45'/4 SCR. SHOWING BACKHOE TRENCH SITES, Sete 1" = 240' SAMPLE SITES, AND CROSS SECTION LINES Note: Plan view map reduced Trom original map 3501 w Sn~ sT, prepared by PAC-TECH Engineering, Inc. ANnCOptES. WA 99221 PLAN VIEW OF PORTION OF TRASK PARCEL >~ ~. i»6 `~ I O ~~ r ~~ 3 ~ „.. - -~. . ~ it v ~ t TREE S '~.. .. a LGrs~ lj,~e`19 .+' ~~ ~) ~ ~~ tit see I • 13.32" • /30' • s • 4S "/4 SHOWING LOCATION OF GROUPS OF LEANING TREES AND LOW AREAS TO BE FILLED AND SLOPED TO DRAIN scale 1'• = 2ao• Note• Plan view ma reduced from on inai ma ~ 1• Ii. ~(•(YI'I• Kr ~15~O(~ I/1TI;S p ~ p 3501 W Sn~ Sr prepared by PAC-TECH F,ngineering, Inc. AN4CORiES, WA 9A221 .PLAN VIEW OF PORTION OF TRASK PARCEL M~q• !• 1'f6 ~~ Attachment 2 ~~~ i i Qvt l ,~ ~ _ -.?rs ' ~ " Qpf SECTION A - A' /~1= . -- /eo leo aoo •ec Soo Qvt 1 I« ~- •' .. ~r~,z~~r_ ~ ~ - - - Qpr SF,CTiON R - R' r.o Aeo s0o 4oe a1DO Qvtl r« ~_, . ~~ • ~ - ~ / . SECTION C-C' _ l/_ ioo 20o Joo 400 ~,n --- Qvt l ~.o .~ Qpf SECTION D-D' ~ Scale 1" = 120' /oo .ea aoo Leo J. B. SCOTT RL ASSOCIATES NOTES: (1) Dashed lines are approximate or projected contacts 3601 W. STN Sr. from base or exposures. ANACORTES. WA 98221 (2) Sections were reduced from orginal drawings having scale of 1" = 50' (3) Cross hatched zones are consolidated clayey silt beds. CR093 SECTIONS A-A', B-B', C-C', & D-D' A Hu..l.w.n..f 0 ii i~ ~i C~ G i ATTAC~~VVIEENT 4 - LABORAT4R~ TEST RESULTS ' Attachment { ' D U - 1 UNCONFINED COMPRESSION TEST - DU1 ' N:+me Jim Scoff-~- Date r1a-+ 3 1`~9Cn _ E Job No. Locaton~oSS2SSi0.~ 1' ~oi.ti'~' rhn_ t-~oocl ~ G, a.,~ [3oring No. L.c~r.J¢-r` `~~o;~- Sam le No ~1 p . Depth/Elev. Description of Sample Proving [ling No. A aratus N pp o. Wat C er ontent Determination Tare No. ~~~ Wt. Specimen Wet -~ Tare ~~~ gms. Y f `t Wt. Specimen Dry ~- Tare 39~o gms. Wt. IYacer r0~ gms, Water Content i n % Dry Wt~. ' Wt. Tare -~ 1 (D ~ Zlte gms. at 1 05°C 35.5 Wt. Specimen Wet _ Z~1W gms, Unit Weight Wet ~llh•O'11,~' l.~iC.O gm/cc ' Wt. Specimen Dry IBC gms. Unit Weight Dry ~~S•bnPc~) ~ • 3~2 gm/cc Unconfined Compressive Strength Initial Diameter Do y.lJr cm Final Diameter ~[,'4S cm D Initial Area Ao 13.53 cm2 Final Area e Ae IS.Ss •cm2 Initial Height Ho _ 9.~- cm Final Height He `6•S cm Initial Volume Vo 13~• 21 cm3 Final Volume Ve 132_I~ cm3 Test Data 2.5 4 = 0.2(vZ Ao N„ Corr, Area . .,_ ~ „_ ELAPSED TIME•MIN. LOAD DIAL IN 0.0001'• AXIAL LOAD P KO STRAIN DIAL IN ,001•• TOTAL STRAIN (NONE! UNIT STRAIN CORRECTED 2 ARE A. CM STRESS Z KG/CM ~~~ Z , ot~ , 32J ~ Z 30 , u o .3S0 I ~ 3 . vs ,3~5 ~`~ ,100 ,`(fv o •12~ .kzS LZ •ISJ •9So 1y,9~- .17j .4}~ . 4~S ~,IZy l5.y5 o.9c~9 r. ono Z 33 ,200 .Soo , Z lZO Psi Z(~ 3 3 :225 ,StS L 33 ,?S~ .560 ~ 33 .z~~ •s~s ~ 33 ~ .3a~ .voo Failure Conditions Remarks SOILTEST INCORPORATED • 2205 LEE STREET • EVANSTON, ILLINOIS, U,S,A, ' DU - 1 Proving [iinq No. Apparatus No._ ' Name _T,.~ Sco{--1- £}-7' Date. Maw, 3 , 199(, Job No. Looation PoSbC.SSip•n \oih.•~- Oti ~OG~ ~v~C.-, ' boring No. Uppp,r 5(bpe Sample No. _ $•' Z Depth/Elev. [)escription of Sample Watcr Content Determination Tare No. ~- t~- Wt. Specimen Net -f- Tare SI'O .gms. Wt. Specimen Dry -}- Tare y~ gms. Wt. IVater ~~ gms, Wt. Tare ~ I~} @ Z2Z gms. Wt. Specimen Wet Z$93 gms. Wt. Specimen Dry 22~- gms, tlnconfined Compressive Strength ' Initial Diameter Do ~•~~ cm Initial Area Ao 13.3 cm2 Initial Fleight !lo I~•9 cm ' 1 C i Initial Volume Vo I~I~•tly cm3 Test pata UNCONFINED COMPRESSION TEST - DU1 Water Content in % Dry Wt'. at 105°C 29.E Unit Weight Wet~tZl•`~9P~-) i.°t53 gmJcc Unit Weight Dry (.93.91.P~~~ l•506 gm/cc Final Diameter De i•I.ZS cm Final Area Ae ty•I`3 • cm2 Final Height He t0•~ cm Final Volume Ve IS0.3 ~ cm3. 2.54 Z A Ho - 0. 33 Corr. Area . ~ _ tl,,;,° c«.. ELAPSED TIME•MrN. LOAD DIAL IN 0.0001" AxIAL t.DAD P KG STRAIN OIAt, IN ,001" TOTAL STRAIN INCHES UNIT STRAIN CORRECTED ARE A.CMZ STRESS KG/CM2 ~~ ~ S ~2 ,v 05~ .per 33.oS Ic,o .too x.02,3 t3.B,S 2.3~5(o Z.C.Iu ~-~ ,125 5 22D sF $ ,IS"O Failure Conditions liemarks (~Stti or 1~' ~ ti IID SOILTEST INCORPORATED • 2205 LEE STREET • EVANSTON, ILLINOIS, U.S.A.