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Home My WebLink AboutBLD2002-00107 Geotechnical Report y1/ 4of.ci I0b:4d 2b:3bdBB992 GEORESOURCES PAGE 01I06 77.7-- . ' '' " E C otesource LLC P11.263-27± -1023 -'j i 3 Pacific Hwy. E., tex 1-1 Fx.253-639-8992 �J APR - 3 2002 '`` ; ' ife, Washington 98424-2649 .J April 1, 2002 Port Ludlow Associates 781 Walker Way Port Ludlow, Washington 98265 Attention: Mr. Ray Welch Supplemental Report Oeotechnical Engineering Services Residential Lot No, 21 Port Ludlow, Division No. 7 Port Ludlow, Washington JobNo:ORk/140 INTRODUCTION This supplemental report provides additional information related to the proposed site development of Lot 21, Port Ludlow, Division No. 7, in Port Ludlow, Washington. The site is located at 585 Rainier Lane, on an east facing slope, generally north of Port Ludlow Bay. Previously, GeoEngineers completed a geotechnical evaluation for Port Ludlow, Division No. 7, and presented the results of those services in a report dated April 5, 1995. Subsequent letters with site specific recommendations were provided for adjacent lots, 16 through 19. Our understanding of the current proposed development of Lot 21 is based on disc nssions with you, site visit and our review of the site plan. We understand that a single story, single-family residence is proposed for Lot No. 21, and that the floor elevation of the structure will be—the level of-the. eet. We also understand that structural fill material will be placed in the lower portion of the site to support the residential structure. A concrete retaining wall will tie lac . at the r.owe portion of the sill material, although an engineered 2 to 1 slope may be utilized if desired. The foundation support system for the residence will Include a conventional foundation/retaining wail system. a understand that Jefferson County has requested thafihe proposed site development be reviewed for compliance with the geotechnical report. This supplemental report is provided for that purpose. Slopes on the lot south of Lot 21 are between 15 and 46 percent in inclination. The lop of the slopes south of the property are greater than 25 feet from the structure, greater that the recommended geotechnical setback for the plat. Slopes on the east portion of the site, near the boil, din area, range from approximately 10 to 25 percent and reach approximately 12 to 15 feet in height. These slopes extend up from the proposed building site area. The proposed engineered site grading will effectively result itng ag i ainst or flattening of the site slopes. We understand that the trill will reach aooroximate_y 6 to 7 feet in depth. The fill materiel will be retained by an engineered retaining wail or constructed with a 2 to 1 engineered fill sipe.-- Based on the criteria of the7effersvn County Critical Areas Ordinance, the site does not meet the technical criteria of a Landslide Hazard Area. A geotechnical report was previously prepared for the site area to evaluate the effects of the proposed development on the slope stability and to provide engineering recommendations for stable foundations for the structures, The site is underlain by very dense glacial till at depth, based on the previous geotechnical site evaluation. The till was deposited directly below the glacial ice and was consolidated to a very dense, cemented condition by the weight of the overriding ice. No ground water seepage was observed in the explorations excavated in the site area. CONCLUSIONS Based on our site reconnaissance,previous subsurface explorations and geotechnical report, and our understanding of the proposed site development, It is our opinion that the site is suitable for the proposed grading and single-family residence. In fact, it is our opinion that the proposed earthwork will improve stability at the site by reducing the slope inclination along the east portion of the site. 01/25!1999 DO:48 2536388992 GECRESOURCES PAGE 02/06 r Pr. Ludlow Associ • Lot 21 April 2, 2002 We observed no evidence of recent or past deep seated landsliding in the vicinity of the site, The soils at the site have been glacially consolidated to a very dense condition, In our opinion, these consolidated materials are generally not to dee p-seated y subject #allure, it is therefore our opinion that a site-specific geotechnical report is not necessary for Lot 21. Conventional earthwork and foundation support may be utilized at the site. Provided the fill material is placed as structural fill, the footings may be founded on the fill material at an appropriate depth for frost protection. Relative to stormwater discharge, we recommend that the stormwater runoff from the structure be directed to the site's storm pond in accordance with the original geotechnicai recommendations and conditions of approval. We trust this provides the information you require at this time. We appreciate the opportunity to be of service to you on this project. Please contact us should you have any questions concerning our findings or recommendations, or should you require additional information_ Respectfully submitted, GeoRe•, rces Ai ./.7, . / Of :rad P_ Bi• ►-rstaf G Principal P.,s i--. ' ri. ,1,17. r-F pc nr, 1 LI APR - 3 2002 I1 ,I ' ' 1 DEPT OF r• r • BPF3:bpb DocID:ORM.4OT . . • , . - 1/-. 1a4ri. 1 • 14-14 ‘- 5-1--c)-1 v--. i -c,•11De-4) ir‘ PI-A- 1-4-e..--1 AL°H.il\ \ Vii/.21-12.111Yrf-efivi-g 17,0T- 7 4 1 ,e..... e. oz_ 1 I CW-12---1)'121-441•1 1.34!37; L . iii'A,* -/'ij-$4t172.:(. .) 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