The URL can be used to link to this page

1139 SIERRA PL.PDFiiiiiiiiiiiiii 13116 1139 SIERRA PL ADDRESS: / / 3 q '7'_G� TAX ACCOUNT/PARCEL #: nlf)5qF `lQ0D6 ZZl BUILDING PERMIT (NEW STRUCTURE) #: COVENANTS (RECORDED) FOR: CRITICAL AREAS #: DETERMINATION: ❑ Conditional Waiver ❑ Study Required ❑ Waiver CRITICAL AREAS #: DETERMINATION: ❑ Conditional Waiver ❑ Study Required ❑ Waiver DISCRETIONARY PERMIT #'S: DRAINAGE PLAN DATED: PARKING AGREEMENTS DATED: EASEMENT(S) RECORD FOR: PERMITS (OTHER — list permit #'s): PLANNING DATA CHECKLIST DATED: SCALED PLOT PLAN DATED: SEWER LID FEE $: LID #: SHORT PLAT FILE: LOT: BLOCK: SIDE SEWER AS BUILT DATED: SIDE SEWER PERMIT(S) #: GEOTECH REPORT DATED: STREET USE/ENCROACHMENT PERMIT #: FOR: "WATER METER TAP CARD DATED: OTHER: L:\TEMP\DST's\Forms\Jana's Street File Checklist 5-14-08.doc CITY OF EDMONDS 121 5th AVENUE NORTH • EDMONDS, WA 98020 • (425) 771-0220 • FAX (425) 771-0221 Website: www dedmonds.wa.us DEVELOPMENT SERVICES DEPARTMENT C. 1890 December 14, 2011 Darryl Lewis PO Box 60037 Shoreline, WA 98160 Re: Building Permit Application: Site Address: 1139 Sierra PI Expiration Date: 3/19/2012 Dear Darryl Lewis, BLD2010-0196 / New Single Family Residence MIKE COOPER MAYOR The purpose of this letter is to inform you that the above permit application will expire on 3/19/2012. According to Edmonds Community Development Code Chapter 19.00.010D, applications are only valid for a period of 1 year unless a written request for extension is submitted to the Building Official for a total period of two years. Our records indicate that you have already received an additional year for this application and no further extensions can be granted. Please be advised, once the permit application expires, the application materials and plans will be destroyed within ten working days of expiration. Also, if the project is pursued in the future a new permit application, plans pertaining to existing adopted building code and new fees will be required. If you have any questions, please feel free to call our offices at 425-771-0220. Sincerely, -� -��Gt// AG9u dY%� Linda Thornquist Permit Specialist City of Edmonds (n'un-4 cQ41L.&ancQ ptcL40uP C��Dltcanf�2efo-� aovpmeco pluQS ) 4/ 1 b/f 7, Incorporated_August 11, 1890 Sister City - Hekinan, Japan Ah .� of EDk City of Edmonds Permit Application Form Form aOl0—�Iq`Le f��. i890 Site Address: I I Sno County Tax Account Parcel #:_ Business/Tenant Name (if applicable PROPERTY OWNER:AWPAL �^ Mailing AdON LIL I, YAK City: LN44- AV%N#- 42 Phone: ( A^Ill ) F E-Mail:^c woo, Lc.,-, APPLICANT/CONTACT: Fill out the following inform - Name & Mailing Address] City: I — Phone: ( ) E-Mail: CONTRACTOR: uite # Mailing Address: City: State: Zip: Phone: ( ) FAX: ( ) E-Mail: State License Number: Exp: Date: City Business License No: L\TEMIDWILDINMHANDOUTS REVISED IN 2009\2009 updated handouts\FORM A.doc 10/16/2009 1 OF EDP City of Edmonds 1'/ u Permit Application Form Form A IOC. i ago Permit Application .for: 0 New Single Family ❑ New Com/Apt ❑ Addition ❑ Interior Remodel ❑. Garage/Carport ❑ Repair ❑ Sign ❑ Fence. ❑ Grading- cvds ❑ Storage/Shed ❑ Tenant. Improvement/Change of Use ❑ Fire System (Specify) ❑ Rockery/Retaining Wall ❑-Other_(Specify) DATE: 3%ZC e Brief Description: L-P-wi5 — , v,v,,t 12a(� Site Address: 113q S► Sno County Tax Account Pa Business/Tenant Nameji#oap� PROPERTY OWNER: Mailing Addre City: Phone: CONTRACTOR: Aame a: Mailing Address: City: Phone: ( ) Sui si S; XKI �' a FAX: (" 'U— ) I I L- FAX: ( ) E-Mai G Iawi•Sfr�ojQ `� '9mo'l l.C;\ State License Number: Exp: Date: City Business License No: APPLICANT/CONTACT: `Same as Property Owner ❑Same as Contractor ❑Other Fill out the following information if "Other". .Name & Mailing Address: City: State: Zip: Phone: ( ' ) FAX: ( ) E-Mail: L:\TEMP\BUILDING\WEBchecklists\SFR.COMM.APP.doc5/24/2007 0 Associated Earth Sciences, Inc. Ce��ali�� dues 2� Zfear�a f S'ev�ice June 24, 2008 Project No. EE070659B Interbay Properties, LLC 1445 NW 186`' Street Shoreline, Washington 98177 Attention: Mr. Darryl Lewis Subject: Rockery Design Proposed Residence 1142 Sierra Place Edmonds, Washington Dear Mr. Lewis: EDM 09-06 APR 012009 As requested, Associated Earth Sciences, Inc. (AESI) is pleased to provide this letter presenting our geotechnical engineering recommendations for construction of rockeries at the above -referenced site. AESI has previously completed geotechnical explorations on the site as part of a geotechnical study. The report was titled "Subsurface Exploration, Geologic Hazard, and Preliminary Geotechnical Engineering Report, Proposed Edmonds Property, Edmonds, Washington", dated January 25, 2008. AESI used the information in the above referenced report to design both cut and fill rockeries for the subject property. ROCKERY RECOMMENDATIONS Rockeries may be used to prevent erosion of cut slopes in dense, natural soils. Unreinforced rockeries are not engineered structures and should not be used in place of retaining walls. Rockeries facing structural fill greater than 3 feet high require the inclusion of geogrid at specified elevations, as shown on the attached plan sheet to function as intended. Structures and pavement should be set back from rockeries so that a 1H:1V (Horizontal: Vertical) line extending up from the rear base of the rockery does not intersect a structure footing. The rockeries were designed to include a 250-pounds-per-square-foot (psf) surcharge to account for traffic loading conditions. A geotechnical engineer should observe foundation conditions, placement of drainage aggregate, and, where applicable, placement of structural fill to confirm that construction of the rockery is in general accordance with the recommendations presented herein. Kirkland Everett Tacoma 425-827-7701 425-259-0522 253-722-2992 www.aesgeo.com The following notes present rockery construction recommendations. Rockery details for rockeries constructed against native soils and for rockeries constructed against reinforced fills are shown on the attached plan sheet. In addition, the contractor should confirm that his configurations conform to current City of Edmonds specifications. • The base of the rockery should be started by excavating a trench to a minimum depth of 12 inches below subgrade into firm, unyielding ground. If loose, soft, existing fill or disturbed materials exist at the base rock location, they should be removed and replaced with free -draining sand and gravel or crushed rock. This backfill material should be compacted to a minimum of 90 percent of the modified Proctor maximum density using American Society for Testing and Materials (ASTM):D 1557 as the standard. • The base rock should have a minimum width (perpendicular to the line of the rockery) of 40 percent of the height of the rockery. All rocks should also meet the following weight requirements: Height of Rockery Minimum Weight of Rock Above 5 feet 500/2,200 pounds, graded, top/bottom rocks 5 feet or less 50011,000 pounds, graded, top/bottom rocks • The rock material should all be as nearly rectangular as possible. No stone should be used that does not extend through the wall. The rock material should be hard, sound, durable, and free from weathered portions, seams, cracks, or other defects. The rock density should be a minimum of 160 pounds per cubic foot (pcf). • Rock selection and placement should be such that there will be minimum voids, and in the exposed face of the wall, no open voids over 8 inches across in any direction. The rocks should be placed in a manner such that the longitudinal axis of the rock will be at right angles or perpendicular to the rockery face. Each rock should be placed so as to lock into two rocks in the lower tier. After setting each rock course, all voids between the rocks should be chinked on the back with quarry rock to eliminate any void sufficient to pass a 2-inch square probe. • A drain consisting of rigid, perforated, polyvinyl chloride (PVC) pipe bedded in a 12-inch-wide, pea gravel trench should be placed behind the lower course of rock to remove water and prevent the buildup of hydrostatic pressure behind the rockery. The remainder of the rockery backfill (for cut rockeries) should consist of quarry spalls with a maximum size of 4 inches and a minimum size of 2 inches. This material should be placed to a 12-inch minimum thickness behind the entire rockery. The backfill material should be placed in lifts to an elevation approximately 6 inches below the top of each course of rocks as they are placed until the uppermost course is placed. Any backfill material falling onto the bearing surface of a rock course should be removed before the setting of the next course. 2 • Rockeries facing structural fill should include a chimney drain, as shown on the plan sheet. A chimney drain is hydraulically connected to the drain system, runs under the structural fill, and extends two-thirds of the total height of the rockery. Drainage aggregate for the drains should consist of granular, free -draining clean, crushed rock with less than 5 percent fines by volume. • Any asphalt paving or final lot grades should be sloped to drain away from the rockery. In addition, the areas above rockeries should be permanently protected from erosion as soon as possible after rockery construction. • A geotechnical engineer must observe foundation conditions, placement of drainage aggregate, and, where applicable, placement of structural fill to confirm that construction of the rockery is in general accordance with the plans and specifications. We trust that the wall design details will aid in the successful completion of the project. If there are questions regarding the wall design, please contact us. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Everett, Washington Edwardo Garcia, P.E. Project Engineer Attachment: Plan Sheet EG/dr EE070659B5 Proj ects\20070659\EE\W P \NEW A. P� F w z FG/STER�� NAt to Z-z-/o Matthew A. Miller, P.E. Associate Engineer 3 MSEW -- Mechanically Stabilized Earth Walls Present Daterrim Thu Jun 26 14:52:08 2008 1142 Sierra Place, Edmonds ckery\EE070359B reinf rockery pegrid.BEN Associated Earth Sciences, Inc. AASHTO DESIGN METHOD 1142 Sierra Place, Edmonds PROJECT IDENTIFICATION Title: 1142 Sierra Place, Edmonds Project Number: EE070659B Client: Interbay Properties LLC Designer: EJL Station Number: Description: Geogrid Reinforced Rockery up to 7-ft max height. Geogrid to be 1Vliragrid SXT, Synteen SF55,=or Stratagrid 350 at Length = PI fight_+ 2,) Company's information: Name: Associated Earth Sciences, Inc. Street: 911 Fifth Avenue Kirkland, WA 98033 Telephone #: 425.827.7701 Fax #: 425.827.5424 E-Mail: elim@aesgeo.com Original file path and name: Z:\O1Projects\07s\070659 Interbay Rockery\EE070359B rei..... .....f rockery pegrid.BEN Original date and time of creating this file: Thu Jun 26 14:09:40 2008 PROGRAM MODE: ANALYSIS of a SIMPLE STRUCTURE using GEOGRID as reinforcing material. 1142 Sierra Place, Edmonds Page 1 of 5 Convright ® 1998-2006 ADAMA Engineering. Inc. License number MSEW-301043 MSEW -- Mechanically Stabilized Earth Walls 1142 Sierra Place, Edmonds Presetit Datell'ime: VamOIOM)fM Vein IO NMW VNTmhuNJSuVe2u6'1 :)562M :b2l0o08 Z\01Projects\07s\0706591nterhay Rockery\EE070359B einf rockery pegrid.BEN NMW Vaio.lON)EM Ve.b>ON]EMV�n)o NSFM Va`.a IOMSl11'VanIO H)EV.'V lO NSEWV )0M]FMV 66VY Vedn>o NSEP'V )OM4R'V )Ew VM.bfOH)EVIV 0 sEw vOmslOM)EMVm]o M560/V�lo SOIL DATA REINFORCED SOIL Unit weight, y 130.0 lb/ft 3 Design value of internal angle of friction, 34.00 RETAINED SOIL Unit weight, y 130.0 lb/ft 3 Design value of internal angle of friction, 34.00 FOUNDATION SOIL (Considered as an equivalent uniform soil) Equivalent unit weight, y e4uiv. 130.0 lb/ft 3 Equivalent internal angle of friction, �Nui,.. 34.00 Equivalent cohesion, c equiv. 0.0 lb/ft 2 Water table does not affect bearing capacity LATERAL EARTH PRESSURE COEFFICIENTS Ka (internal stability) = 0.2827 (if batter is less than 10°, Ka is calculated from eq. 15. Otherwise, eq. 38 is utilized) Inclination of internal slip plane, w= 62.000 (see Fig. 28 in DEMO 82). Ka (external stability) = 0.3979 (if batter is less than 10°, Ka is calculated from eq. 16. Otherwise, eq. 17 is utilized) BEARING CAPACITY Bearing capacity coefficients (calculated by MSEW): Nc = 42.16 N y= 41.06 SEISNUC ITY Note: specified a combined with I and &roduced a square root of -0.05 in eq. 37a. MSEW set this square root to ZERO so that the Kae could be calculated. Be aware that the end results are likely erroneous and ARE PROVIDED FOR INFORMATION ONLY Maximum ground acceleration coefficient, a o = 0.160 Kae ( ao> 0) = 1.1035 Kae ( as 0) = 0.3979 A Kae = 0.7056 (see eq. 37 in DEMO 82) Seismic soil-geogrid friction coefficient, F* is 80.0% of its specified static value. 1142 Sierra Place, Edmonds Page 2 of 5 Copyright ® 1998-2006 ADAMA Engineering, Inc. License number MSEW-301043 MSEW -- Mechanically Stabilized Earth Walls 1142 Sierra Place, Edmonds Present Date1l ime: Thu Jun 26'1 : 2:0g 2008 Z:\Ol Projects\07s\070659 Interbay Rockery\EE070359B reinf rockerypegrid.BEN Ve Pr Mat Vtla]eYEM._ l Vev)eN.4Y VNJs]e YIIM Ve�)0YA1'VwsLNeEV Vwale4S.M Veyle YRVVm)eM]A/Ve.b)OYYV/Veu�)eY4M Veme)oNsfM VadmleNftle V�v)0Y4V Veo)au]EM V�emle N>aV/VeoIeMIIV VerNleuaEv vavleN]E]/Vea)0Y4Y V�da)a INPUT DATA: Geogrids (Analysis) D A T A Geogrid Geogrid Geogrid Geogrid Geogrid type #1 type #2 type #3 type #4 type #5 Tult jlb/ftj 4200.0 Durability reduction factor, RFd 1.10 Installation -damage reduction factor, RFid 1.22 Creep reduction factor, RFc 1.60 N/A N/A N/A N/A Fs -overall for strength N/A Coverage ratio, Rc 1.000 Friction angle along geogrid-soil interface, p 29.80 Pullout resistance factor, F* 0.80•tano N/A N/A N/A N/A Scale -effect correction factor, a 1.0 Variation of Lateral Earth Pressure Coefficient With Depth Z K/Ka 0 ft 1.00 3.3 ft 1.00 6.6 ft 1.00 9.8 ft 1.00 13.1 ft 1.00 16.4 ft 1.00 19.7 ft 1.00 Z IN 0.0 1.0 32.8 K/Ka 2.0 3.0 1142 Sierra Place, Edmonds Copyright 0 1998-2006 ADAMA Engineering, Inc. Page 3 of 5 License number MSEW-301043 MSEW -- Mechanically Stabilized Earth Walls 1142 Siena Place, Edmonds Present Date/rime: Thu Jun 26 14:52:08 2001 Z:\01 Projects\07s\070659 Interbay Rockery\EE070359B reinf rockery pegrid.BEN v..�.�ewsev �.�.�.wmvv.:s,nuuwr.a.�.w�.vr.®,euuvv.e�euun v.�.r.�srw�..�,�uManv v.:e,�.wssvv.:e.�•wssvr.:��.Mssvv.o .waNv.:.�nws�w v.:o. �.asswv.o>.wavv.o�. INPUT DATA: Geometry and Surcharge loads (of a SIMPLE STRUCTURE) Design height, Hd 7.00 [ft] { Embedded depth is E = 1.00 ft, and height above top of finished bottom grade is H = 6.00 ft } Batter, w 0.0 [deg] Backslope, a 26.0 [deg] Backslope rise 20.0 [ft] Broken back equivalent angle, I = 26.00° (see Fig. 25 in DEMO 82) UNIFORM SURCHARGE j --- - " __ j Uniformly distributed dead load is 0.0 [lb/ft 2], and live load is 250.0 [lb/ft 2] SCALE: 0 2 4 6 [ft] 1142 Sierra Place, Edmonds Page 4 of 5 Copyright @ 1998-2006 ADAMA Engineering, Inc. License number MSEW-301043 �MSEW -- Mechanically Stabilized Earth Walls 1142 Sierra Place, Edmonds Prcseni DateZM. Thu Jun 26 14:52:08 2008 ZA0 I Projects\07s\070659 Interbay Rockery]EE070359B rcinf rockery pegrid.BEN v �J,v.b]ev J.4]EMy .4uvv snrv..e e .,,.v.�.,.4>,.v..�,.4,�v.�.,.4,�vo .4,..�v..,.,.4>�v.�. •,..,v..,,.4�v..o.,.4>zwv.o,.4.,,,v.:s,.4:..,v.:e.,. ANALYSIS: CALCULATED FACTORS (Static conditions) Bearing capacity, Fs = 10.49, Meyerhof stress = 1828 lb/ft2. P—.,d.r;f,., Tnf—IF ro• Tl;—,* AM— Fe = 7 nno R...,.,ran — n n4n1 T7o_ ..,o f,....:... — 1 G[ GEOGRID CONNECTION Fs -overall Fs -overall Fs -overall Geogrid Pullout Direct Eccentricity Product # Elevation Length Type [pullout [connection [geogrid strength resistance sliding e/L name IN [ft] # resistance] break] strength] Fs Fs Fs 1 0.00 8.00 1 N/A N/A N/A 7.283 37.406 1.706 0.0601 Synteen SF55 2 1.50 8.00 1 N/A N/A N/A 4.117 16.257 1.812 0.0278 Synteen SF55 3 3.00 8.00 1 N/A N/A N/A 4.985 14.512 1.922 -0.0052 Synteen SF55 4 4.50 8.00 1 N/A N/A N/A 6.316 12.785 2.018 -0.0422 Synteen SF55 5 6.00 8.00 1 N/A N/A N/A 7.616 9.793 2.042 -0.0936 Synteen SF55 ANALYSIS: CALCULATED FACTORS (Seismic conditions) Bearing capacity, Fs = 5.10, Meyerhof stress = 2706 lb/ftz. Rn,,.,.i�t;nn r.,to, F . o• rl;—,+ ].1;.1;,,,. Ro — 1 1d7 R o„r.: :,,] o/T — n 1 044 Rom7 nn GEOGRID CONNECTION Fs -overall Fs -overall Fs -overall Geogrid Pullout Direct Eccentricity Product # Elevation Length Type [pullout [connection [geogrid strength resistance sliding e/L name [ft] [ft] # resistance] break] strength] Fs Fs Fs 1 0.00 8.00 1 N/A N/A N/A 5.715 20.796 1.054 0.1955 Synteen SF55 2 1.50 8.00 1 N/A N/A N/A 3.613 10.631 1.204 0.1160 Synteen SF55 3 3.00 8.00 1 N/A N/A N/A 4.333 9.359 1.406 0.0446 Synteen SF55 4 4.50 8.00 1 N/A N/A N/A 5.413 8.074 1.671 -0.0210 Synteen SF55 5 6.00 8.00 1 N/A N/A N/A 6.496 6.140 1.942 -0.0897 Synteen SF55 Vwh.lA4,SM V.W. ]AJI]El. Veb. ].➢.6,v VW,.➢Y,EV vmia J.➢,I]JiY Ve.b. ].➢4J6V Vmi.l.➢,I3E1' Va.b ].➢.6EM VM.I.O4,E'v VNa ]A4,6.1 Ve.b.J➢4JE]v Vmb.JA4,f W Va.b,.➢43E'Y VmbJA45EW Vnb J.,,I]EA' Va.b] oMSEW VNmJ,16EW V.,Y. ]., M,fiV VUIa L,I,EW VnbJA]IJfW Vm1-l➢YJEV Vn]-]A 1142 Sierra Place, Edmonds Page 5 of 5 Copyright m 1998-2006 ADAMA Engineering, Inc. License number MSEW-301043 EDM 08-27 Geotechnical Engineering Water Resources Associated Earth Sciences, Inc. Cel�i��rfi�,Zy' Je�psofJesri>ce Subsurface Exploration, Geologic Hazard, and Preliminary Geotechnical Engineering Report PROPOSED EDMONDS RESIDENCE Environmental Assessments and Remediation Sustainable Development Services Geologic Assessments Edmonds, Washington Prepared for Interbay Properties, LLC Project No. EE070659A January 25, 2008 Q EECE EECE Associated Earth Sciences, Inc. r El FTI NJ W:1 W rCefe&abng Auer25'Jean of.S'emce 11 January 25, 2008 Project No. EE070659A Interbay Properties, LLC ' 1445 NW 186"' Street Shoreline, Washington 98177 Attention: Mr. Darryl Lewis Subject: Subsurface Exploration, Geologic Hazard, and Preliminary Geotechnical Engineering Report Proposed Edmonds Property Edmonds, Washington Dear Mr. Lewis: We are pleased to present the enclosed copies of the above -referenced report. This report L summarizes the results of our subsurface exploration, geologic hazard, and geotechnical engineering studies and offers recommendations for the preliminary design and development of the proposed project. Our recommendations are preliminary in that construction details have not been finalized at the time of this report. We have enjoyed working with you on this study and are confident that the recommendations presented in this report will aid in the successful completion of your project. If you should have any questions or if we can be of additional help to you, please do not hesitate to call. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington Ie��' G V40 Jon D s Senior Staff Geologist JDH11d EE070659A5 Projects\20070659\EE\WP Kirkland Everett Tacoma 425-827-7701 425-259-0522 253-722-2992 www.aesgeo.com I I SUBSURFACE EXPLORATION, GEOLOGIC HAZARD, AND PRELIMINARY GEOTECHNICAL ENGINEERING REPORT PROPOSED EDMONDS RESIDENCE Edmonds, Washington Prepared for: Interbay Properties, LLC 1445 NW 180' Street Shoreline, Washington 98177 Prepared by: Associated Earth Sciences, Inc. 2911 '/z Hewitt Avenue, Suite 2 Everett, Washington 98201 425-259-0522 Fax: 425-252-3408 January 25, 2008 Project No. EE070659A Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Project and Site Conditions ' I. PROJECT AND SITE CONDITIONS 1.0 INTRODUCTION This report presents the results of Associated Earth Sciences, Inc.'s (AESI's) subsurface exploration, geologic hazard, and geotechnical engineering study for the proposed Edmonds residence located at 1142 Sierra Place in Edmonds, Washington (Figure 1). Some existing site features, including topographic contours and the approximate locations of the explorations accomplished for this study, are presented on the client -provided "Site and Exploration Plan," Figures 2. The recommendations to this report are considered to be preliminary because grading plans and construction details were not finalized at the time of this study. Once development plans are ' substantially complete, the conclusions and recommendations in this report should be reviewed and modified, or verified as appropriate. 1.1 Purpose and Scope ' The purpose of this study was to provide subsurface data to be used in the preliminary design, site preparation, site grading, and development of the subject project. Our study included a review of available geologic literature, excavation of exploration pits, and performing geologic ' studies to assess the type, thickness, distribution, and physical properties of the subsurface sediments and shallow ground water conditions. Geotechnical engineering studies were also conducted to assess the type of suitable foundation, allowable foundation soil bearing ' pressures, anticipated settlements, basement/retaining wall lateral pressures, floor support recommendations, sensitive area hazard mitigation, and drainage considerations. This report summarizes our current fieldwork and offers development recommendations based on our present understanding of the project. We recommend that we be allowed to review project plans prior to construction to verify that our geotechnical engineering recommendations have ' been correctly interpreted and incorporated into the design and provide additional recommendations, as appropriate. 1 1.2 Authorization Written authorization to proceed with this study was granted by Mr. Darryl Lewis of Interbay Properties, LLC. Our study was accomplished in general accordance with our proposal dated October 3, 2007. This report has been prepared for the exclusive use of Interbay Properties, LLC and their agents for specific application to this project. Within the limitations of scope, schedule, and budget, our services have been performed in accordance with generally accepted geotechnical engineering and engineering geology practices in effect in this area at the time our report was prepared. No other warranty, express or implied, is made. January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. IJDHIld - EE070659A5 - Projecrs1200706591EEMP Page 1 1 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Project and Site Conditions 2.0 PROJECT AND SITE DESCRIPTION 2.1 Site Description The subject site consists of a rectangular -shaped vacant residential parcel of approximately 0.9 acre located at 1142 Sierra Place in Edmonds, Washington. The property is currently undeveloped. The property is naturally forested with stands of second -growth coniferous and deciduous trees and moderate to thick underbrush. The topography of the site generally consists of moderately sloping terrain with delineated wetland areas over the western half of the parcel and a west to east trending utility easement along the southern property boundary. Overall, the vertical relief across the site is approximately 70 feet, based on the site survey. The topography generally dips down toward the west and northwest portions of the site. A site plan provided by the client includes topographic contours over the site. Review of the topographic contours shown on this site plan indicates that slope gradients in the mapped portion of the steeper, northeast portions of the site range from approximately 30 to 35 percent. A visual reconnaissance of the site indicates that topographic gradients in this area appear similar to that found on the site survey (i.e., approximately 30 percent). Based on the above observations, it does not appear the on -site slopes meet the City of Edmonds criteria for treatment as a landslide hazard area. 2.2 Project Description Our understanding of the project plans is based on information presented in discussions with Mr. Darryl Lewis of Interbay Properties, LLC. It is our understanding that conceptual plans call for the construction of a new one- to two-story, single-family residence with a daylight or full basement, several 4-foot-high rockeries, access roads, buried utilities, and other typical site improvements. We understand that the locations of the residence and rockeries as shown are approximate, and construction details, such as the proposed cut depths and final site grades, are not known at this time. 1 3.0 SUBSURFACE EXPLORATION Our field study included excavating two exploration pits to gain subsurface information about the site. The various types of sediments, as well as the depths where characteristics of the sediments changed, are indicated on the exploration logs presented in the Appendix. The depths indicated on the logs where conditions changed may represent gradational variations between sediment types. Our explorations were approximately located in the field relative to known site features shown on a topographic site plan provided by the client. The approximate locations of the explorations are shown on the "Site and Exploration Plan," Figure 2. I January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. ' JDH/!d - EE070659A5 - Projects1200706591EEMP Page 2 i Subsurface Exploration, Geologic Hazard, and ' Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Project and Site Conditions ' The conclusions and recommendations presented in this report are based, in part, on the conditions encountered in the exploration pits completed for this study. The number, locations, and depths of the explorations were completed within site and budgetary constraints. Because of the nature of exploratory work below ground, extrapolation of subsurface conditions beyond the field explorations is necessary. Differing subsurface conditions may be present outside of the area of the field explorations due to the random nature of deposition and the alteration of topography by past grading and/or filling. The nature and extent of any variations beyond the field explorations may not become fully evident until construction. If 1 variations are observed at that time, it may be necessary to re-evaluate specific recommendations in this report and make appropriate changes. ' 3.1 Exploration Pits Exploration pits were excavated with a track -mounted excavator owned and operated by ' Northwest Excavating and Trucking of Mill Creek, Washington. The pits permitted direct, visual observation of subsurface conditions. Materials encountered in the exploration pits were ' studied and classified in the field by a geologist from our firm. All exploration pits were backfilled immediately after examination and logging. Selected samples were then transported to our laboratory for further visual classification and testing, as necessary. 4.0 SUBSURFACE CONDITIONS Subsurface conditions at the project site were inferred from the exploration pits completed for this study, our visual reconnaissance of the site, and applicable geologic literature. As shown on the exploration logs, the exploration pits generally encountered consolidated medium dense grading to very dense silty sand with gravel and cobbles, interpreted as lodgement till, overlain by a few to several feet of weathered soils. The following section presents more detailed subsurface information organized from the youngest to the oldest sediment types. Review of the regional geologic map titled Preliminary Surficial Geologic Map of the Edmonds East and Edmonds West Quadrangles, Snohomish and King Counties, Washington, by Makey Smith (1975) indicates that the site is underlain by Vashon lodgement till. Our interpretation of the sediments encountered in our explorations is in general agreement with the regional geologic map. ' 4.1 Stratigraphy Forest Duff/Topsoil A surficial organic topsoil layer was encountered at each of the exploration locations. The g P Y topsoil layer was approximately 1 to 1.5 feet thick. Due to their high organic content, these 1 January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. ' JDH/ld - EE070659A5 - Projects1200706591EEMP Page 3 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Project and Site Conditions ' materials are not considered suitable for foundation or pavement support, slab -on -grade floor, or for use in a structural fill. Colluvium Sediments encountered below the topsoil layer generally consisted of loose to medium dense, very moist to wet, gray to bluish gray silty fine sand containing little gravel and trace organics. We interpret these sediments to be representative of a localized colluvium deposit. The sediments were likely deposited from soil creep and shallow raveling of the adjacent hillslope. Colluvium sediments were encountered in exploration pit EP-2 to a depth of approximately 2.5 feet and are thought to extend farther west towards the wetland areas of the site. These materials are not considered suitable for foundation or pavement support, slab -on -grade floor, or for use in a structural fill. ' Vashon Lodgement Till Sediments encountered directly below the surficial topsoil and/or colluvium layer generally consisted of medium dense to dense, brown, silty fine sand with little gravel and trace amounts of cobbles. Below depths of approximately 2.5 to 3.5 feet, these sediments became dense, ' gray in color, and contained a slightly higher concentration of cobbles. We interpret these sediments to be representative of the Vashon lodgement till. 'The lodgement till sediments were deposited at the base of an active continental glacier and were subsequently overrun by ' several thousand feet of glacial ice during the Vashon Stade of the Fraser Glaciation, approximately 15,000 years ago. Lodgement till was deposited at the base of an active continental glacier and was subsequently compacted by the weight of the overlying glacial ice. ' Lodgement till typically possesses high -strength and low -compressibility attributes that are favorable for support of foundations, floor slabs, and paving with proper preparation. Lodgement till is silty and moisture -sensitive. In the presence of moisture contents above the ioptimum moisture content for compaction purposes, lodgement till can be easily disturbed by vehicles and earthwork equipment. Careful management of moisture -sensitive soils, as recommended in this report, will be needed to reduce the potential for disturbance of wet lodgement till soils and costs associated with repairing disturbed soils. The reduced density observed in the upper portion of this unit is interpreted to be due to weathering. The Vashon lodgement till sediments extended beyond the maximum depths explored of approximately 14 feet below surrounding grade. 4.2 Hydrology Light to moderate ground water seepage was encountered within both explorations EP-1 and EP-2 at depths of 4 feet and again at depths of 11 feet below surrounding grade. The upper seepage, which was located near the contact between the weathered and unweathered portions of the lodgement till, is interpreted as interflow. Interflow is a type of seasonal perched January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. 1 JDH/ld - EE070659A5 - Projects1200706591EEMP Page 4 Li I Subsurface Exploration, Geologic Hazard, and ' Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Project and Site Conditions rground water condition that occurs where surface water infiltrates down through the relatively permeable, surficial weathered till and perches upon the relatively impermeable, unweathered lodgement till. The interflow generally migrates atop the less permeable, unweathered till roughly following the surface topography. Interflow is often a seasonal phenomenon. It should be noted that the presence and depth of seepage at the site may vary in response to such ' factors as changes in season, precipitation, and site use. The lower seepage, which appeared light in flow, was encountered within a sandier zone in the till and found over an approximate soil interval of 6 inches. Further, several areas of standing water and/or saturated surficial Isoils were noted in the lowland areas located in the central and western portions of the site. 1 1 I� I i 1 January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. ' JDH/ld - EE070659A5 - Projects 1200706591EEIWP Page 5 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Geologic Hazards and Mitigations ' II. GEOLOGIC HAZARDS AND MITIGATIONS The following discussion of potential geologic hazards is based on the geologic, slope, and shallow ground water conditions as observed and discussed herein. 5.0 SEISMIC HAZARDS AND MITIGATION 1 i� Earthquakes occur in the Puget Lowland with great regularity. The vast majority of these events are small and are usually not felt by people. However, large earthquakes do occur, as evidenced by the 1949, 7.2-magnitude event; the 2001, 6.8-magnitude event; and the 1965, 6.5-magnitude event. The 1949 earthquake appears to have been the largest in this region during recorded history and was centered in the Olympia area. Evaluation of earthquake return rates indicates that an earthquake of the magnitude between 5.5 and 6.0 is likely within a given 20-year period. Generally, there are four types of potential geologic hazards associated with large seismic events: 1) surficial ground rupture, 2) seismically induced landslides, 3) liquefaction, and 4) ground motion. The potential for each of these hazards to adversely impact the proposed project is discussed below. 5.1 Surficial Ground Rupture Generally, the largest earthquakes that have occurred in the Puget Sound area are subcrustal ' events with epicenters ranging from 50 to 70 kilometers in depth. The 1949 and 2001 Olympia earthquakes are good examples of this type of seismic activity. Although the energy from deep subcrustal earthquakes does propagate up to the ground surface, actual surficial faulting and earth rupture features are rare. However, loose, wet soils may liquefy, move laterally, landslide, or otherwise settle or move, causing cracks and ruptures in the surficial soils during earthquakes. These types of damages are not related to actual fault rupture, but are a result of ground shaking and liquefaction (see below). To our knowledge, no surficial faulting or earth rupture has been documented to date in the proposed project area. Therefore, it is our opinion, ' based on the existing geologic data, that the risk of surface rupture impacting the proposed project is low. ' 5.2 Seismically Induced Landslides The topography of the proposed project area generally slopes moderately down to the west with gradients ranging from 25 to 35 percent. Chapter 23.80 of the City of Edmonds Municipal Code defines a Steep Slope Hazard Area as "any area with a slope of 40 percent or steeper and with a vertical relief of 10 or more feet except areas composed of, or consolidated January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDH/ld - EE070659A5 - Projects1200706591EEMP Page 6 Subsurface Exploration, Geologic Hazard, and ' Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Geologic Hazards and Mitigations trock. " Therefore, the location of the proposed single-family residence does not lie within a designated Steep Slope Hazard Area and does not warrant mitigation. 5.3 Liquefaction ' Liquefaction is a process through which unconsolidated soil loses strength as a result of vibratory shaking, such as that which occurs during a seismic event. During normal conditions, the weight of the soil is supported by both grain -to -grain contacts and by the pressure within the pore spaces of the soil below the water table. Extreme vibratory shaking can disrupt the grain -to -grain contact, increase the pore pressure, and result in a decrease in soil shear strength. The soil is said to be liquefied when nearly all of the weight of the soil is ' supported by pore pressure alone. Liquefaction can result in deformation of the sediment and settlement of overlying structures. Areas most susceptible to liquefaction include those areas underlain by coarse silt and sand with low relative densities, accompanied by a shallow water ' table. ' Our exploration pits typically encountered unsaturated, glacially consolidated soils that are not considered susceptible to liquefaction and hence, do not warrant mitigation. ' 5.4 Ground Motion Based on the site stratigraphy and visual reconnaissance of the site, it is our opinion that any ' earthquake damage to the proposed structures, when founded on suitable bearing strata, would be caused by the intensity and acceleration associated with the event and not any of the above - discussed impacts. Structural design of buildings should follow 2006 International Building Code (IBC) standards using Site Class "C", as defined in Table 1613.5.1. The 2006 IBC seismic design parameters for short period (Ss) and 1-second period (Si) spectral acceleration values were determined by the latitude and longitude of the project site using the United States ' Geological Survey (USGS) National Seismic Hazard Mapping Project website'. Based on the more current 2002 data, the USGS website interpolated ground motions at the project site to be 1.21g and 0.42g for building periods of 0.2 and 1.0 seconds, respectively, with a 2-percent chance of exceedence in 50 years. 6.0 EROSION HAZARDS AND MITIGATION ' To mitigate the erosion hazards and potential for off -site sediment transport, we would recommend the following: http://earthquake.usgs.gov/hazmaps/ January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDH/ld - EE070659A5 - Projects1200706591EEI WP Page 7 1 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Geologic Hazards and Mitigations 1. The winter performance of a site is dependent on a well -conceived plan for control of site erosion and storm water runoff. It is easier to keep the soil on the ground than to remove it from storm water. The owner and the design team should include adequate ground -cover measures, access roads, and staging areas in the project bid to give the selected contractor a workable site. The selected contractor needs to be prepared to implement and maintain the required measures to reduce the amount of exposed ground. A site maintenance plan should be in place in the event storm water turbidity measurements are greater than the Ecology standards. 2. All TESC measures for a given area to be graded or otherwise worked should be installed prior to any activity within an area other than installing the TESC features or timber harvesting. The recommended sequence of construction within a given area after timber harvesting would be to install sediment traps and/or ponds and establish perimeter flow control prior to starting mass grading. ' during 3. During the wetter months of the year, or when large storm events are predicted g ' the summer months, each work area should be stabilized so that if showers occur, the work area can receive the rainfall without excessive erosion or sediment transport. The required measures for an area to be "buttoned -up" will depend on the time of year and ' the duration the area will be left un-worked. During the winter months, areas that are to be left un-worked for more than 2 days should be mulched or covered with plastic. During the summer months, stabilization will usually consist of seal -rolling the ' subgrade. Such measures will aid in the contractor's ability to get back into a work area after a storm event. The stabilization process also includes establishing temporary storm water conveyance channels through work areas to route runoff to the approved ' treatment facilities. 4. All disturbed areas should be revegetated as soon as possible. If it is outside of the ' growing season, the disturbed areas should be covered with mulch, as recommended in the erosion control plan. Straw mulch provides the most cost-effective cover measure ' and can be made wind -resistant with the application of a tackifier after it is placed. 5. Surface runoff and discharge should be controlled during and following development. Uncontrolled discharge may promote erosion and sediment transport. Under no circumstances should concentrated discharges be allowed to flow over the surface of steep slopes. 6. Soils that are to be reused around the site should be stored in such a manner as to reduce erosion from the stockpile. Protective measures may include, but are not limited to, covering with plastic sheeting, the use of low stockpiles in flat areas, or the use of straw bales/silt fences around pile perimeters. During the period between October 1" and March 31", these measures are required. January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDHIld - EE070659A5 - Projects1200706591EEMP Page 8 Subsurface Exploration, Geologic Hazard, and ' Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Geologic Hazards and Mitigations 7. On -site erosion control inspections and turbidity monitoring (if required) should be performed in accordance with Ecology requirements. Weekly and monthly reporting to Ecology should be performed on a regularly scheduled basis. TESC monitoring should be part of the weekly construction team meetings. Temporary and permanent erosion control and drainage measures should be adjusted and maintained, as necessary, at the ' time of construction. It is our opinion that with the proper implementation of the TESC plans and by field -adjusting ' appropriate mitigation elements (BMPs) during construction, as recommended by the erosion control inspector, the potential adverse impacts from erosion hazards on the project may be mitigated. 1 1 1 1 1 11 January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. ' JDH/[d - EE070659A5 - Projects12007065MEMP Page 9 Subsurface Exploration, Geologic Hazard, and ' Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Preliminary Design Recommendations ' III. PRELIMINARY DESIGN RECOMMENDATIONS 7.0 INTRODUCTION Our exploration indicates that, from a geotechnical standpoint, the parcel is suitable for the proposed development provided the recommendations contained herein are properly followed. The foundation bearing stratum is relatively shallow and conventional spread footing ' foundations and standard pavement sections may be utilized. Consequently, foundations bearing on either the medium dense to dense, natural glacial sediments or on structural fill placed over these sediments are capable of providing suitable building support. ' 8.0 SITE PREPARATION 8.1 Clearing and Stripping ' Site preparation of the planned building area should include removal of all trees, brush, debris, and any other deleterious materials. These unsuitable materials should be properly disposed of ' off -site. Additionally, any areas of organic topsoil should be removed and the remaining roots grubbed. Areas where loose surficial soils exist due to grubbing operations should be considered as fill to the depth of disturbance and treated as subsequently recommended for structural fill placement. Any buried utilities should be removed or relocated if they are under the proposed building area. The resulting depressions should be backfilled with structural fill, as discussed under the "Structural Fill" section of this report. Any existing fill soils below ' footing areas should be stripped down to the underlying, medium dense to dense natural sediments. ' After stripping and grubbing operations have been completed, we recommend that the soil exposed in the proposed driveway and any other pavement areas be recompacted to a firm and ' unyielding condition. Any soft or yielding areas identified during compaction should be overexcavated and backfilled with structural fill. 8.2 Temporary Cut Slopes In our opinion, stable construction slopes should be the responsibility of the contractor and ' should be determined during construction based on the local conditions encountered at that time. For planning purposes, we anticipate that temporary, unsupported cut slopes in the medium dense to dense, weathered glacially consolidated sediments can be made at a maximum slope of 1.5H:1V (Horizontal: Vertical). Temporary cut slopes within the dense to very dense, unweathered lodgement till sediments can be planned up to a 1H:1V inclination. As is typical with earthwork operations, some sloughing and raveling may occur, and cut slopes may have January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. IJDH/ld - EE070659A5 - Projects1200706591EEMP Page 10 Subsurface Exploration, Geologic Hazard, and ' Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Preliminary Design Recommendations tto be adjusted in the field. In addition, WISHA/OSHA regulations should be followed at all times. ' 8.3 Site Disturbance ' The site soils contain a high percentage of fine-grained material, which makes them moisture - sensitive and subject to disturbance when wet. The contractor must use care during site preparation and excavation operations so that the underlying soils are not softened. If ' disturbance occurs, the softened soils should be removed and the area brought to grade with structural fill. If crushed rock is considered for the access and staging areas, it should be underlain by stabilization fabric (such as Mirafi 50OX or approved equivalent) to reduce the ' potential of fine-grained materials pumping up through the rock and turning the area to mud. The fabric will also aid in supporting construction equipment, thus reducing the amount of crushed rock required. We recommend that at least 10 inches of rock be placed over the fabric; however, due to the variable nature of the near -surface soils and differences in wheel loads, this thickness may have to be adjusted by the contractor in the field. Crushed rock used I for access and staging areas should be of at least 2-inch size. ' 9.0 STRUCTURAL FILL Although final grading plans were not available to AESI at the time of this study, we anticipate ' that structural fill may be necessary to establish desired grades in some areas. All references to structural fill in this report refer to subgrade preparation, fill type, and placement and compaction of materials, as discussed in this section. If a percentage of compaction is ' specified under another section of this report, the value given in that section should be used. 9.1 Subgrade Compaction After overexcavation/stripping has been performed to the satisfaction of the geotechnical engineer/engineering geologist, the upper 12 inches of exposed ground should be recompacted to a firm and unyielding condition. If the subgrade contains too much moisture, suitable recompaction may be difficult or impossible to obtain and should probably not be attempted. ' In lieu of recompaction, the area to receive fill should be blanketed with washed rock or quarry spalls to act as a capillary break between the new fill and the wet subgrade. Where the exposed ground remains soft and further overexcavation is impractical, placement of an engineering stabilization fabric may be necessary to prevent contamination of the free -draining layer by silt migration from below. After recompaction of the exposed ground is tested and approved, or a free -draining rock course is laid, structural fill may be placed to attain desired grades. January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. tJDH/!d - EE070659A5 - Projects 1200706591EEI WP Page 11 Subsurface Exploration, Geologic Hazard, and ' Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Preliminary Design Recommendations ' 9.2 Keying and Benching ' All structural fills planned to be placed on existing slopes steeper than 20 percent are required to have a keyway constructed at the toe of the fill body and the slope to be benched prior to placing fill. The keyway should be excavated a minimum of 2 feet down into firm, dense, natural sediments and be a minimum of 8 feet in width. The width for the benches should be established in the field to fit the contour and gradient of the slope being filled. ' 9.3 Structural Fill Compaction Structural fill is defined as non -organic soil, acceptable to the geotechnical engineer, placed in ' maximum 8-inch loose lifts, with each lift being compacted to at least 95 percent of the modified Proctor maximum dry density using American Standard for Testing and Materials (ASTM):D 1557 as the standard. Roadway and utility trench backfill should be placed and ' compacted in accordance with applicable municipal codes and standards. The top of the compacted fill should extend horizontally a minimum distance of 3 feet beyond footings or ' pavement edges before sloping down at an angle no steeper than 2H:1V. Fill slopes should either be overbuilt and trimmed back to final grade or surface -compacted to the specified density. 9.4 Moisture -Sensitive Fill ' Soils in which the amount of fine-grained material (smaller than No. 200 sieve) is greater than approximately 5 percent (measured on the minus No. 4 sieve size) should be considered moisture -sensitive. Use of moisture -sensitive soil in structural fills should be limited to ' favorable dry weather conditions. The on -site soils contain significant amounts of silt and are considered moisture -sensitive. Construction equipment traversing the site when the soils are very moist or wet can cause considerable disturbance. If fill is placed during wet weather or if ' proper compaction cannot be obtained, a select import material consisting of a clean, free - draining gravel and/or sand should be used. Free -draining fill consists of non -organic soil with ' the amount of fine-grained material limited to 5 percent by weight when measured on the minus No. 4 sieve fraction. 9.5 Structural Fill Testing The contractor should note that any proposed fill soils must be evaluated by AESI prior to their ' use in fills. This would require that we have a sample of the material at least 3 business days in advance to perform a Proctor test and determine its field compaction standard. ' A representative from our firm should inspect the stripped subgrade and be present during placement of structural fill to observe the work and perform a representative number of in - place density tests. In this way, the adequacy of the earthwork may be evaluated as filling January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. I JDH/ld - EE070659A5 - Projects1200706591EEMP Page 12 1 Subsurface Exploration, Geologic Hazard, and ' Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Preliminary Design Recommendations progresses and any problem areas may be corrected at that time. It is important to understand that taking random compaction tests on a part-time basis will not assure uniformity or ' acceptable performance of a fill. As such, we are available to aid the owner in developing a suitable monitoring and testing frequency. . 10.0 FOUNDATIONS ' 10.1 Allowable Soil Bearing Pressure Spread footings may be used for building support when founded either directly on the medium 1 dense to very dense, natural glacial sediments, or on structural fill placed over these materials, as described under the "Site Preparation" and "Structural Fill" sections of this report. For footings founded either directly upon the medium dense to very dense glacial sediments, or on ' structural fill as described above, we recommend that an allowable bearing pressure of 2,000 pounds per square foot (psf) be used for design purposes, including both dead and live loads. ' An increase of one-third may be used for short-term wind or seismic loading. If structural fill is placed below footing areas, the structural fill should extend horizontally beyond the footing edges a distance equal to or greater than the thickness of the fill. 10.2 Footing Depths ' Perimeter footings for the proposed building should be buried a minimum of 18 inches into the surrounding soil for frost protection. No minimum burial depth is required for interior footings; however, all footings must penetrate to the prescribed stratum, and no footings 1 should be founded in or above loose, organic, or existing fill soils. We recommend that an evaluation of the foundation subgrade be performed prior to placement of concrete. At the location of both exploration pits, located in the area of the proposed home, sediments suitable for foundation support were encountered at a depth of approximately 1.5 to 2.5 feet below the existing ground surface. The distribution and thickness of unsuitable colluvium sediments may ' not be uniform throughout the site, and overexcavation of some footing areas may be expected. Furthermore, foundations on the west side must be deep enough to allow a setback of 15 feet where that elevation would daylight on the slope. 1 10.3 Footings Adjacent to Cuts ' The area bounded by lines extending downward at 111:1V from any footing must not intersect another footing or intersect a filled area that has not been compacted to at least 95 percent of ASTM:D 1557. In addition, a 1.5H:1V line extending down from any footing must not ' daylight because sloughing or raveling may eventually undermine the footing. Thus footings should not be placed near the edges of steps or cuts in the bearing soils. 1 January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. ' !DH/ld - EE070659A5 - Projects1200706591EE1 WP Page 13 ' Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Preliminary Design Recommendations ' 10.4 Footing Settlement Anticipated settlement of footings founded as described above should be on the order of 1 inch or less. However, disturbed soil not removed from footing excavations prior to footing placement could result in increased settlements. 10.5 Footing Subgrade Bearing Verification All footing areas should be observed by AESI prior to placing concrete to verify that the exposed soils can support the design foundation bearing capacity and that construction ' conforms with the recommendations in this report. Foundation bearing verification may also be required by the governing municipality. ' 10.6 Foundation Drainage ' Perimeter footing drains should be provided, as discussed under the "Drainage Considerations" section of this report. 11.0 LATERAL WALL PRESSURES ' All backfill behind walls or around foundations should be placed following our recommendations for structural fill and as described in this section of the report. Horizontally backfilled walls, which are free to yield laterally at least 0.1 percent of their height, may be ' designed using an equivalent fluid equal to 35 pounds per cubic foot (pcf). Fully restrained, horizontally backfilled, rigid walls that cannot yield should be designed for an equivalent fluid of 50 pcf. Walls that retain sloping backfill at a maximum angle of 60 percent should be ' designed for 55 pcf for yielding conditions and 75 pcf for restrained conditions. If parking areas or driveways are adjacent to walls, a surcharge equivalent to 2 feet of soil should be ' added to the wall height in determining lateral design forces. 11.1 Wall Backfill The lateral pressures presented above are based on the conditions of a uniform backfill consisting of either the on -site glacial sediments or imported sand and gravel compacted to 90 to 95 percent of ASTM:D 1557. A higher degree of compaction is not recommended, as this will increase the pressure acting on the walls. A lower compaction may result in unacceptable settlement behind the walls. Thus, the compaction level is critical and must be ' tested by our firm during placement. The recommended compaction of 90 to 95 percent of ASTM:D 1557 applies to any structural fill placed behind the wall within a distance equal to the wall height and up to the elevation of the top of the wall. Structural fill used to construct January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. I JDH/ld - EE070659A5 - Projects1200706591EEMP Page 14 Subsurface Exploration, Geologic Hazard, and ' Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Preliminary Design Recommendations slopes above retaining walls should be compacted to at least 95 percent of ASTM:D 1557 if the fill is placed above the elevation of the top of the wall. Surcharges from adjacent footings, ' heavy construction equipment, or sloping ground must be added to the above -recommended lateral pressures. Footing drains should be provided for all retaining walls, as discussed under the "Drainage Considerations" section of this report. 11.2 Passive Resistance and Friction Factor ' Lateral loads can be resisted by friction between the foundation and the natural, medium dense to dense glacial sediments or supporting structural fill soils, or by passive earth pressure acting on the buried portions of the foundations. The foundations must be backfilled with compacted structural fill to achieve the passive resistance provided below. We recommend the following allowable design parameters: ' • Passive equivalent fluid = 300 pcf • Coefficient of friction = 0.35 12.0 FLOOR SUPPORT n U F 1 11 Slab -on -grade floors may be constructed either directly on the medium dense to dense natural sediments, or on structural fill placed over these materials. Areas of the slab subgrade that are disturbed (loosened) during construction should be recompacted to an unyielding condition prior to placing the pea gravel, as described below. If moisture intrusion through slab -on -grade floors is to be limited, the floors should be constructed atop a capillary break consisting of a minimum thickness of 4 inches of washed pea gravel. The pea gravel should be overlain by a 10-mil (minimum thickness) plastic vapor retarder. 13.0 DRAINAGE CONSIDERATIONS The natural glacial sediments encountered in our explorations generally contained significant amounts of silt and are considered to be highly moisture -sensitive. Traffic from vehicles, construction equipment, and even foot traffic across these sediments when they are very moist or wet will result in disturbance of the otherwise firm stratum. Therefore, prior to site work and construction, the contractor should be prepared to provide drainage and subgrade protection, as necessary. 1 January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDH11d - EE070659A5 - Projects1200706591EEIWP Page 15 ' Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Preliminary Design Recommendations ' 13.1 Wall/Foundation Drains ' All retaining and perimeter footing walls should be provided with a drain at the footing elevation. The drains should consist of rigid, perforated, polyvinyl chloride (PVC) pipe surrounded by washed pea gravel. The level of the perforations in the pipe should be set approximately 2 inches below the bottom of the footing, and the drains should be constructed with sufficient gradient to allow gravity discharge away from the building. All retaining walls should be lined with a minimum, 12-inch-thick, washed gravel blanket provided to within ' 1 foot of finish grade, and which ties into the footing drain. Roof and surface runoff should not discharge into the footing drain system, but should be handled by a separate, rigid, tightline drain. ' Exterior grades adjacent to walls should be sloped downward away from the structure to g J P Y ' achieve surface drainage. Final exterior grades should promote free and positive drainage away from the building at all times. Water must not be allowed to pond or to collect adjacent to the foundation or within the immediate building area. It is recommended that a gradient of at least 3 percent for a minimum distance of 10 feet from the building perimeter be provided, except in paved locations. In paved locations, a minimum gradient of 1 percent should be provided unless provisions are included for collection and disposal of surface water adjacent to ' the structure. Additionally, pavement subgrades should be crowned to provide drainage toward catch basins and pavement edges. ' 14.0 PROJECT DESIGN AND CONSTRUCTION MONITORING ' We are available to provide additional geotechnical consultation as the project design develops and possibly changes from that upon which this report is based. The recommendations in this ' report are considered to be preliminary because grading plans and construction details were not finalized at the time of this study. If significant changes in grading are made, we recommend that AESI perform a geotechnical review of the plans prior to final design completion. In this way, our earthwork and foundation recommendations may be properly interpreted and implemented in the design. ' We are also available to provide geotechnical engineering and monitoring services during construction. The integrity of the foundations depends on proper site preparation and construction procedures. In addition, engineering decisions may have to be made in the field in the event that variations in subsurface conditions become apparent. Construction monitoring services are not part of this current scope of work. If these services are desired, please let us know, and we will prepare a proposal. January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. ' JDH/!d - EE070659A5 - Projects1200706591EDWP Page 16 ' Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Preliminary Design Recommendations ' We have enjoyed working with you on this study and are confident that these recommendations will aid in the successful completion of your project. If you should have any questions or ' require further assistance, please do not hesitate to call. 1� u I� L� LI Sincerely, ASSOCIATED EARTH SCIENCES, INC. Everett, Washington - /-�� --' d"A,2= Jon . Hansen Senior Staff Geologist Attachments: Figure 1: Vicinity Map Figure 2: Site and Exploration Plan Appendix: Exploration Logs Vey Ws2/8lc� 1 Matthew A. Miller, P.E. Associate Engineer January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDH/!d - EE070659A5 - Projects 1200706591EEIWP Page 17 i i i i 1• s SW to" LJtI,t ;�— .� PL �1a �t f r, f� ST St( F� $1J 195iN ST t`` o %� Sw ' * . __71 196TH _ I GET ST SW kAPLEMOOD', c s: su z '°- t- I 198TN HEINZ .-^e� i tLEY VIE4lLaf�O - WY HILL PARK sr s -t J , .�..- s��i - LN — �---- , _ - i n- - _ 4 a r 98TH ; f,: e f 5TH '= P_ jpL eR00KMERE _ S7 .... _ _, *.. s' 199TH .�ic� �`�+ i +-1 1 ^ i 198TH �z_X X7�` ; (V I ,a,. f �+ C 19TH S7 $wST StyS7 Sty , ,2 . Cn co iVIEI't�AOR { SITES ! ! `'p� S� Q s`�200TH S7 Sty 200TH , Ma'luT„t�s PL SW VISTA ! WY - -.•--- a- 200TH ST St'! _ I2015T 41 2ots sr DR i �'t..SC n_ 201ST FL o 202ND ST PZO SH SW i U CAROL ; wy SI ERR !- a pR sw 202ND 3� )= 202ND F — i PL �ti 202t1B P 7 t Jt 7 i L ¢ ST S4! I� t� `� 2U2HD PLSi! is L, PL Sw a' a GLEN ST SIERRk ST sw �`_ S s 24wK� 203RD ST ksw I Sw PL s� -- 203RD S'f SI+! iE39. .r x i 2DIRD ?L S>' i r1 ST a h of °Q 204TH2MFH ST SW ' d R13sF C' 204TH I a a t ST, SV Zir;7H j .x ¢iF! ( O "ST =/PLSM'P4 sm QSIJ`--� —z'� 0 205TH 3 f ' a- PINE i 20s1! �' -. ��sn:RO }4; PL 5tt R DGE > sp ssu 'i r at suNILG PK _ .Q o 2osTx F 4 a V _ I d 206TH t `� ^ f�%tD - - r.. sr sti' ? t e PK ' S7 SW + t i I J { j mod-, BELT EAtEBALD 4 H�CI1� `� 2Go� S 17a 207TH y ST ASH d a =: ST DR u 207TH j FL SYJ h t PL su M= F N S T _ vL-sw� 1 -;. � :.3„ i 2 0 8 T H S T- SW_ t g { ) Q 206n ST CO } ! ?L SO r~ (/) cn j �1 -� 1 q '`' e 208TH�PL- s. wr I __` YOST n 209TH PL ; ^ �� Sit ��ta a� a ¢ MEMORIAL Sw ti �,S�O� 2F0r,V� 3 J }�2� 2o9TH ST 2107H ST ' I N PARKcl -c �. _ PaRx1T71 a "-� = t CO ! n Obi PL & RID:r i 1P"t u - ---- {� _ NO SCALE ...,__<.,,.,..... ...... _ .. __. „ _. . . a c 0 E Associated Earth Sciences, Inc. VICINITY MAP FIGURE 1 k s�• •, ti PROPOSED EDMONDS RESIDENCE DATE 1/08 Lai t EDMONDS, WASHINGTON PROD. NO. EE070659A 0 = 20.00' _... 10s' E 1 L AC E P ` °' Uli; Gut. f1( AIA Reference: Untitled Map from John L. Scott OFF —SITE N A 0 30 SCALE IN FEET W FIGURE 2 Associated Earth Sciences, Inc. SITE AND EXPLORATION PLAN DATE vos GPM 77M PROPOSED EDRESIDENCE EDMONDS, WASH WASHINGTON ' o PROJ. NO. EE070659A m m m m m a ' o Well -graded gravel and Terms Describing Relative Density and Consistency �N o. o. GW gravel with sand, little to Dens' SPTmblows/foot • o no fines Very Loose 0 to 4 > > ' O a) u- � �n Loose 4 to 10 Grained Soils Medium Dense 10 to 30 Test Symbols Y 00000 o 0 0 Poorly -graded gravel c� in vu 0o 00 00000 GP and gravel with sand, Dense 30 to 50 o d 0 0 0 0 0 0 little to no fines Very Dense >50 G= Grain Size o Z 0 000 0 R) M= Moisture Content SPT blows/foot It D 0 o c Consistency A = Atterberg Limits c 0 , . Silty gravel and silty Very Soft 0 to 2 C = Chemical o Co H - GM gravel with sand Fine - Fine- Soft 2 to 4 DD = Dry Density a) m m � • Grained Soils Medium Stiff 4 to 8 K = Permeability c oa) o: FL Stiff 8 to 15 - Clayey gravel and Very Stiff 15 to 30 Gc clayey gravel with sand Hard >30 Component Definitions Descriptive Term Size Range and Sive Number C Well -graded sand and :SW sand with gravel, little Boulders Larger than 12" ..... to no fines Cobbles 3' to 12" m LL ' ' ' ' ' Gravel 3' to No. 4 (4.75 mm) : Poorly -graded sand Ic � Coarse Gravel 3'to 3/4' jvuto ''SP and sand with gravel,Fine Gravel 3/4" to No. 4 (4.75 mm) o little to no fines Sand No. 4 (4.75 mm) to No. 200 (0.075 mm) a!0ZCoarse Sand No. 4 (4.75 mm) to No. 10 (2.00 mm) Silty sand and Medium Sand No. 10 (2.D0 mm) to No. 40 (0.425 mm) SMsilty sand with Fine Sand No. 40 (0.425 mm) to No. 200 (0.075 mm) m o o gravel Silt and Clay Smaller than No. 200 (0.075 mm) in LL Clayey sand and (3) Estimated Percentage Moisture Content r;, in M sc clayey sand with gravel Percentage by Dry - Absence of moisture, rn Component Weight dusty, dry to the touch Trace <5 Slightly Moist - Perceptible Silt, sand silt, ravel) Silt, Y gravelly Few 5 to 10 moisture MIL silt with sand or gravel Little 15 to 25 Moist - Damp but no visble > U) a, m With - Non -primary coarse water 00. y constituents: > 15% Very Moist - Water visible but Clay of low to medium o0 a) plasticity; silty, sandy, or -Fines content between not free draining z CO := CL gravelly clay, lean clay 5 % and 15% Wet - Visible free water, usually m En E from below water table u1 =_ .J — Organic clay or silt of low Symbols n5 2!D or — — oL plasticity Blows/6' or 0 _ Sampler portion of 6" Cement grout ;5 Type / surface seal Elastic Silt, Clayey Silt, Silt Sampler Type 2.0" ODJon a MH with micaceous or u Description Split-Spp t"> seal seal o u? m o diatomaceous fine sand or Sampler3.0' OD Split -Spoon Sampler - Filter pack with 2 T? silt (SPIj 3.25' OD Split -Spoon Ring Sampler t.> _ : blankcasin 9 Clay of high plasticity, �, moo o Bulk sa- section c CH sand or ravel) clay, fat Y gravelly Yr 3.0' OD Thin -Wall Tube Sampler =' Screened casing m y E clay with sand or gravel (including Shelby tube) _` or Hyddrotip with pack - Grab Sa a3 iifi�, Organic clay or silt of Portion not recovered End cap J OH medium to high fti t4) Percentage by dry weight Depth of ground water plasticity (2) (SPT) Standard Penetration Test 1 ATD = At time of drilling >' (ASTM D-1586) Cl Static water level (date) tat In General Accordance with N Peat, muck and other o, Q,'o PT highly organic soils Standard Practice for Description t� Combined USCS symbols used for = V US O and Identification of Soils (ASTM 0=2488) fines between 5%and 15% lassifications of soils in this report are based on visual field and/or laboratory observations, which include density/consistency, moisture condition, grain size, and Iasticity estimates and should not be construed to imply field or laboratory testing unless presented herein. Visual -manual and/or laboratory classification :) methods of ASTM D-2487 and D-2488 were used as an identification guide for the Unified Soil Classification System. D Associated Earth Sciences, Inc. _ a EXPLORATION LOG KEY FIGURE Al Ell, •.car,¢ ?a-:T£? n 1 1 1 1 LOG OF EXPLORATION PIT NO. EP-1 w This log is part of the report prepared ly Associated Earth Sciences, Inc. (AESI) for the named project and should be together with that report for complete interpretation. This summary applies only to the location of this trench at the read time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are p a simplfication of actual conditions encountered. DESCRIPTION Topsoil Loose, moist, brown to dark brown, silty fine SAND, little gravel, few organics. 1 Weathered Vashon Lodgement Till 2 Medium dense, moist to very moist, brown, silty fine SAND, little gravel. 3 Vashon Lodgement Till 4 Medium dense to dense, moist to very moist, gray, silty fine SAND, little gravel, mottled from 3.5 to 6 feet bgs. 5 Grades to dense, very moist, gray, silty fine SAND, with few medium SAND interbeds, little gravel, 6 trace cobbles. 7 8 9 10 11 12 13 14 Bottom of exploration pit at depth 14 feet 15 No caving. Minor seepage at 11 feet bgs. Roots to 3 feet. 16 17 18 19 ' N Proposed Edmonds Residence Edmonds, WA Associated Earth Sciences, Inc. Project No. EE070659A 8 Logged by: JH 'Approved by: % � � k 119108 a H Y I �I 1 LOG OF EXPLORATION PIT NO. EP-2 t This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the location time. The data o time of excavation. Subsurface conditions may change at this with the passage of presented are a simplfication of actual conditions encountered. DESCRIPTION Topsoil Loose, very moist to wet, dark brown, fine sandy SILT, little gravel, few organics. 1 Colluvium Loose to medium dense, very moist to wet, mottled gray to bluish gray, silty fine SAND, little gravel, 2 trace organics. Vashon Lodgement Till 3 Medium dense to dense, very moist to wet, gray, silty fine SAND, with trace medium SAND interbeds, little gravel, trace cobbles, mottled from 2 to 4 feet. 4 5 6 7 8 9 10 Bottom of exploration pit at depth 10 feet 11 Exploration terminated due to caving. Slight caving at 4 feet. Moderate seepage at 4 feet. Roots to 1 foot. 12 13 14 15 16 17 18 19 Proposed Edmonds Residence Edmonds, WA Associated Earth Sciences, Inc. Logged by: '- Approved by:: -' ia. ,'�"'•" Project No. EE070659A 1 /9/08 Associated Earth Sciences, Inc. No IE NJ WJ 0 afe&abT Over25 Yeasfaf S'emce ,t January 25, 2008 Project No. EE070659A Interbay Properties, LLC 1445 NW 186`h Street Shoreline Washington 98177 Attention: Mr. Darryl Lewis Subject: Subsurface Exploration, Geologic Hazard, and . Preliminary Geotechnical Engineering Report Proposed Edmonds Property (� Edmonds, Washington P 0 Dear Mr. Lewis: We are pleased to present the enclosed copies of the above -referenced report. This report summarizes the results of our subsurface exploration, geologic hazard, and geotechnical engineering studies and offers recommendations for the preliminary design and development of the proposed project. Our recommendations are preliminary in that construction details have not been finalized at the time of this report. We have enjoyed working with you on this study and are confident that the recommendations presented in this report will aid in the successful completion of your project. If you should have any questions or if we can be of additional help to you, please do not hesitate to call. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington T� Jon D. Hansen Senior Staff Geologist 1DH/Id EE070659A5 Projects\200706WEEMP 4 L „ aoredi® MAR .2 0 2008 BUILDING DEPARTMEN'i CITY OF EDMOND$ Kirkland Everett 0 Tacoma 425-827-7701 425-259-0522 253-722-2992 www.aesgeo.com C SUBSURFACE EXPLORATION, GEOLOGIC HAZARD, AND PRELIMINARY GEOTECHNICAL ENGINEERING REPORT j� PROPOSED EDMONDS RESIDENCE Edmonds, Washington Prepared for: Interbay Properties, LLC l: 1445 NW 186`' Street Shoreline, Washington 98177 Prepared by: Associated Earth Sciences, Inc. 2911 '/z Hewitt Avenue, Suite 2 Everett, Washington 98201 425-259-0522 Fax: 425-252-3408 . January 25, 2008 Project No. EE070659A �l n Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Project and Site Conditions 4 I. PROJECT AND SITE CONDITIONS i J I 1.0 INTRODUCTION This report presents the results of Associated Earth Sciences, Inc.'s (AESI's) subsurface ' exploration, geologic hazard, and geotechnical engineering study for the proposed Edmonds residence located at 1142 Sierra Place in Edmonds, Washington (Figure 1). Some existing site 1 features, including topographic contours and the approximate locations of the explorations accomplished for this study, are presented on the client -provided "Site and Exploration Plan," 1 Figures 2. The recommendations in this report are considered to be preliminary because grading plans and 1 construction details were not finalized at the time of this study. Once development plans are substantially complete, the conclusions and recommendations in this report should be reviewed and modified, or .verified as appropriate. 1.1 Purpose and Scope 1 The purpose of this study was to provide subsurface data to be used in the preliminary design, site preparation, site grading, and development of the subject project. Our study included a review of available geologic literature, excavation of exploration pits, and performing geologic �] studies to assess the type, thickness, distribution, and physical properties of the subsurface sediments and shallow ground water conditions. Geotechnical engineering studies were also conducted to assess the type of suitable foundation, allowable foundation soil bearing pressures, anticipated settlements, basement/retaining wall lateral pressures, floor support recommendations, sensitive area hazard mitigation, and drainage considerations. This report summarizes our current fieldwork and offers development recommendations based on our [� present understanding of the project. We recommend that we be allowed to review project plans prior to construction to verify that our geotechnical engineering recommendations have been correctly interpreted and incorporated into the design and provide additional recommendations, as appropriate. 1.2 Authorization Written authorization to proceed with this study was granted by Mr. Darryl Lewis of Interbay Properties, LLC. Our study was accomplished in general accordance with our proposal dated October 3, 2007. This report has been prepared for the exclusive use of Interbay Properties, LLC and their agents for specific application to this project. Within the limitations of scope, schedule, and budget, our services have been performed in accordance with generally accepted geotechnical engineering and engineering geology practices in effect in this area at the time our report was prepared. No other warranty, express or implied, is made. January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. n !DH/ld - EE070659A5 - Projects1200706591EEMP Page 1 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Project and Site Conditions i 2.0 PROJECT AND SITE DESCRIPTION 2.1 Site Description The subject site consists of a rectangular -shaped vacant residential parcel of approximately 0.9 acre located at 1142 Sierra Place in Edmonds, Washington. The property is currently undeveloped. The property is naturally forested with stands of second -growth coniferous and deciduous trees and moderate to thick underbrush. The topography of the site generally consists of moderately sloping terrain with delineated wetland areas over the western half of the parcel and a west to east trending utility easement along the southern property boundary. -- Overall, the vertical relief across the site is approximately 70 feet, based on the site survey. The topography generally dips down toward the west and northwest portions of the site. A site plan provided by the client includes topographic contours over the site. Review of the f topographic contours shown on this site plan indicates that slope gradients in the mapped ` portion of the steeper, northeast portions of the site range from approximately 30 to 35 percent. A visual reconnaissance of the site indicates that topographic gradients in this area lappear similar to that found on the site survey (i.e., approximately 30 percent). Based on the above observations, it does not appear the on -site slopes meet the City of Edmonds criteria for treatment as a landslide hazard area. 2.2 Project Description 1 I Our understanding of the project plans is based on information presented in discussions with 1 Mr. Darryl Lewis of Interbay Properties, LLC. It is our understanding that conceptual plans call for the construction of a new one- to two-story, single-family residence with a daylight or full basement, several 4-foot-high rockeries, access roads, buried utilities, and other typical site improvements. We understand that the locations of the residence and rockeries as shown are approximate, and construction details, such as the proposed cut depths and final site grades, are not known at this time. 3.0 SUBSURFACE EXPLORATION Our field study included excavating two exploration pits to gain subsurface information about - the site. The various types of sediments, as well as the depths where characteristics of the sediments changed, are indicated on the exploration logs presented in the Appendix. The l depths indicated on the logs where conditions changed may represent gradational variations t between sediment types. Our explorations were approximately located in the field relative to (� known site features shown on a topographic site plan provided by the client. The approximate I 1 locations of the explorations are shown on the "Site and Exploration Plan," Figure 2. January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDHRd - EE070659A5 - Projects M0706591EEIWP Page 2 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Project and Site Conditions The conclusions and recommendations presented in this report are based, in part, on the conditions encountered in the exploration pits completed for this study. The number, locations, and depths of the explorations were completed within site and budgetary constraints. Because of the nature of exploratory work below ground, extrapolation of subsurface conditions beyond the field explorations is necessary. Differing subsurface conditions may be 1 present outside of the area of the field explorations due to the random nature of deposition and j the alteration of topography by past grading and/or filling. The nature and extent of any variations beyond the field explorations may not become fully evident until construction. If variations are observed at that time, it may be necessary to re-evaluate specific recommendations in this report and make appropriate changes. 3.1 Exploration Pits Exploration pits were excavated with a track -mounted excavator owned and operated by Northwest Excavating and Trucking of Mill Creek, Washington. The pits permitted direct, visual observation of subsurface conditions. Materials encountered in the exploration pits were f studied and classified in the field by a geologist from our firm. All exploration pits were (, backfilled immediately after examination and logging. Selected samples were then transported to our laboratory for further visual classification and testing, as necessary. 4.0 SUBSURFACE CONDITIONS Subsurface conditions at the project site were inferred from the exploration pits completed for this study, our visual reconnaissance of the site, and applicable geologic literature. As shown on the exploration logs, the exploration pits generally encountered consolidated medium dense grading to very dense silty sand with gravel and cobbles, interpreted as lodgement till, overlain by a few to several feet of weathered soils. The following section presents more detailed subsurface information organized from the youngest to the oldest sediment types. Review of the regional geologic map titled Preliminary Surficial Geologic Map of the Edmonds East and Edmonds West Quadrangles, Snohomish and King Counties, Washington; by Makey Smith (1975) indicates that the site is underlain by Vashon lodgement till. Our, interpretation of the sediments encountered in our explorations is in general agreement with the regional geologic map. 4.1 Stratigraphy Forest Duff/Topsoil A surficial . organic topsoil layer was encountered at each of the exploration locations. The topsoil layer was approximately 1 to 1.5 feet thick. Due to their high organic content, these January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDHI& - EE070659A5 - Projects1200706591EEMP Page 3 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Project and Site Conditions materials are not considered suitable for foundation or pavement support, slab -on -grade floor, or for use in a structural fill. Colluvium Sediments encountered below the topsoil layer generally consisted of loose to medium dense, very moist to wet, gray to bluish gray silty fine sand containing little gravel and trace organics. I We interpret these sediments to be representative of a localized colluvium deposit. The sediments were likely deposited from soil creep and shallow raveling of the adjacent hillslope. Colluvium sediments were encountered in exploration pit EP-2 to a depth of approximately 2.5 feet and are thought to extend farther west towards the wetland areas of the site. These materials are not considered suitable for foundation or pavement support, slab -on -grade floor, or for use in a structural fill. Vashon Lodgement Till (� Sediments encountered directly below the surficial topsoil and/or colluvium layer generally J consisted of medium dense to dense, brown, silty fine sand with little gravel and trace amounts of cobbles. Below depths of approximately 2.5 to 3.5 feet, these sediments became dense, l l gray in color, and contained a slightly higher concentration of cobbles. We interpret these (1 sediments to be representative of the Vashon lodgement till. 'The lodgement till sediments were deposited at the base of an active continental glacier and were subsequently overrun by (� several thousand feet of glacial ice during the Vashon Stade of the Fraser Glaciation, l approximately 15,000 years ago. Lodgement till was deposited at the base of an active continental glacier and was subsequently compacted by the weight of the overlying glacial ice. Lodgement till typically possesses high -strength and low -compressibility attributes that are favorable for support of foundations, floor slabs, and paving with proper preparation. Lodgement till is silty and moisture -sensitive. In the presence of moisture contents above the [ optimum moisture content for compaction purposes, lodgement till can be easily disturbed by vehicles and earthwork equipment. Careful management of moisture -sensitive soils, as recommended in this report, will be needed to reduce the potential for disturbance of wet �J lodgement till soils and costs associated with repairing disturbed soils. The reduced density observed in the upper portion of this unit is interpreted to be due to weathering. The Vashon f lodgement till sediments extended beyond the maximum depths explored of approximately 1 14 feet below surrounding grade. n 4.2 Hydrology Light to moderate ground water seepage was encountered within both explorations EP-1 and EP-2 at depths of 4 feet and again at depths of 11 feet below surrounding grade. The upper seepage, which was located near the contact between the weathered and unweathered portions n of. the lodgement till, is interpreted as interflow. Interflow is a . type of seasonal perched January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. nJDH/ld - EE070659A5 - Projects120070659TEIWP Page 4 I_I a 0 Subsurface Exploration, Geologic Hazard, and f Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Project and Site Conditions ground water condition that occurs where surface water infiltrates down through the relatively permeable, surficial weathered till and perches upon the relatively impermeable, unweathered lodgement till. The interflow generally migrates atop the less permeable, unweathered till roughly following the surface topography. Interflow is often a seasonal phenomenon. It should be noted that the presence and depth of seepage at the site may vary in response to such factors as changes in season, precipitation, and site use. The lower seepage, which appeared light in flow, was encountered within a sandier zone in the till and found over an approximate soil interval of 6 inches. Further, several areas of standing water and/or saturated surficial soils were noted in the lowland areas located in the central and western portions of the site. January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDHRd - EE070659A5 - Projeas1200706591MWP Rage 5 1 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Geologic Hazards and Mitigations II. GEOLOGIC HAZARDS AND MITIGATIONS The following discussion of potential geologic hazards is based on the geologic, slope, and shallow ground water conditions as observed and discussed herein. 5.0 SEISMIC HAZARDS AND MITIGATION Earthquakes occur in the Puget Lowland with great regularity. The vast majority of these events are small and are usually 'not felt by people. However, large earthquakes do occur, as evidenced by the 1949, 7.2-magnitude event; the 2001, 6.8-magnitude event; and the 1965, 6.5-magnitude event. The 1949 earthquake appears to have been the largest in this region during recorded history and was centered in . the Olympia area. Evaluation of earthquake return rates indicates that an earthquake of the magnitude between 5.5 and 6.0 is likely within a given 20-year period. Generally, there are four types of potential geologic hazards associated with large seismic events: 1) surficial ground rupture, 2) seismically induced landslides, 3) liquefaction, and 4) ground motion. The potential for each of these hazards to adversely impact the proposed project is discussed below. 5.1 Surficial Ground Rupture Generally, the largest earthquakes that have occurred in the Puget Sound area are subcrustal events with epicenters ranging from 50 to 70 kilometers in depth. The 1949 and 2001 Olympia earthquakes are good examples of this type of seismic activity. Although the energy from deep subcrustal earthquakes does propagate up to the ground surface, actual surficial faulting and earth rupture features are rare. However, loose, wet soils may liquefy, move laterally, landslide, or otherwise settle or move, causing cracks and ruptures in the surficial soils during earthquakes. These types of damages are not related to actual fault rupture, but are a result of ground shaking and liquefaction (see below). To our knowledge, no surficial faulting or earth rupture has been documented to date in the proposed project area. Therefore, it is our opinion, based on the existing geologic data, that the risk of surface rupture impacting the proposed project is low. 5.2 Seismically Induced Landslides The topography of the proposed project area generally slopes moderately down to the west with gradients ranging from 25 to 35 percent.. Chapter 23.80 of the City of Edmonds Municipal Code defines a Steep Slope Hazard Area as "any area with a slope of 40 percent or steeper and with a vertical relief of 10 or more feet except areas composed of, or consolidated January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDHRd - EE070I659A5 - Projeas1200706591EEMP Page 6 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Geologic Hazards and Mitigations rock. " Therefore, the location of the proposed single-family residence does not lie within a designated Steep Slope Hazard Area and does not warrant mitigation. 5.3 Liquefaction 1 Liquefaction is a process through which unconsolidated soil loses strength as a result of vibratory shaking, such as that which occurs during a seismic event. During normal conditions, the weight of the soil is supported by both grain -to -grain contacts and by the 1 pressure within the pore spaces of the soil below the water table. Extreme vibratory shaking I can disrupt the grain -to -grain contact, increase the pore pressure, and result in a decrease in soil shear strength. The soil is said to be liquefied when nearly all of the weight of the soil is supported by pore pressure alone. Liquefaction can result in deformation of the sediment and settlement of overlying structures. Areas most susceptible to liquefaction include those areas underlain by coarse silt and sand with low relative densities, accompanied by a shallow water (� table. ( 0ur.exploration pits typically encountered unsaturated, glacially consolidated soils that are not { considered susceptible to liquefaction and hence, do not warrant mitigation. 5.4 Ground Motion Based on the site stratigraphy and visual reconnaissance of the site, it is our opinion that any l J earthquake damage to the proposed structures, when founded on suitable bearing strata, would l J be caused by the intensity and acceleration associated with the event and not any of the above - discussed impacts. Structural design of buildings should follow 2006 International Building Code (IBC) standards using Site Class "C", as defined in Table 1613.5.1. The 2006 IBC seismic design parameters for short period (Ss) and 1-second period (Si) spectral acceleration values were determined by the latitude and longitude of the project site using the United States [� Geological Survey (USGS) National Seismic Hazard Mapping Project website'. Based on the more current 2002 data, the USGS website interpolated ground motions at the project site to be (l 1.21g and 0.42g for building periods of 0.2 and 1.0 seconds, respectively, with a 2-percent LJ chance of exceedence in 50 years. L) 6.0. EROSION HAZARDS AND MITIGATION To mitigate the erosion hazards and potential for off -site sediment transport, we would recommend the following: o. http://darthquake.usgs.gov/hazmaps/ _ January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. nJDH/id - EE070659A5 - Projects1200706591EEMP Page % 1. 1 l Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds Washington Geologic Hazards and Mitigations H_ I H 1. The winter performance of a site is dependent on a well -conceived plan for control of site erosion and storm water runoff. It is easier to keep the soil on the ground than to remove it from storm water. The owner and the design team should include adequate ground -cover measures, access roads, and staging areas in the project bid to give the selected contractor a workable site. The selected contractor needs to be prepared to implement and maintain the required measures to reduce the amount of exposed ground. A site maintenance plan should be in place in the event storm water turbidity measurements are greater than the Ecology standards. 2. All TESC measures for a given area to be graded or otherwise worked should be installed prior to any activity within an area other than installing the TESC features or timber harvesting. The recommended sequence of construction within a given area after timber harvesting would be to install sediment traps and/or ponds and establish perimeter flow control prior to starting mass grading. 3. During the wetter months of the year, or when large storm events are predicted during the summer months, each work area should be stabilized so that if showers occur, the work area can receive the rainfall without excessive erosion or sediment transport. The required measures for an area to be "buttoned -up" will depend on the time of year and the duration the area will be left un-worked. During the winter months, areas that are to be left un-worked for more than 2 days should be mulched or covered with plastic. During the summer months, stabilization will usually consist of seal -rolling the subgrade. Such measures will aid in the contractor's ability to get back into a work area after a storm event. The stabilization process also includes establishing temporary storm water conveyance channels through work areas to route runoff to the approved treatment facilities. 4. All disturbed areas should be revegetated as soon as possible. If it is outside of the growing season, the disturbed areas should be covered with mulch, as recommended in the erosion control plan. Straw mulch provides the most cost-effective cover measure and can be made wind -resistant with the application of a tackifier after it is placed. 5. Surface runoff and discharge should be controlled during and following development. Uncontrolled discharge may promote erosion and sediment transport. Under no circumstances should concentrated discharges be allowed to flow over the surface of steep slopes. 6. Soils that are to be reused. around the site should be stored in such a manner as to reduce erosion from the stockpile. Protective measures may include, but are not limited to, covering with plastic sheeting, the use of low stockpiles in flat areas, or the use of straw bales/silt fences around pile perimeters. During the period between October 1' and March 3151, these measures are required. H January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. !DH/ld - EE070659A5 - ProjecW200706591EE1WP Page 8 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Geologic Hazards and Mitigations 7. On -site erosion control inspections and turbidity monitoring (if required) should be performed in accordance with Ecology requirements. Weekly and monthly reporting to Ecology should be performed on a regularly scheduled basis. TESC monitoring should be part of the weekly construction team meetings. Temporary and permanent erosion control and drainage measures should be adjusted and maintained, as necessary, at the time of construction. his our opinion that with the proper implementation of the TESC plans and by field -adjusting appropriate mitigation elements (BMPs) during construction, as recommended by the erosion control inspector, the potential adverse impacts from erosion hazards on the project may be mitigated. 1 0 January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. {� JDH/[d - EE070659A5 - Projeds1200706591EEIWP Page 9 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Preliminary Design Recommendations III. PRELIMINARY DESIGN RECOMMENDATIONS 7.0 INTRODUCTION j Our exploration indicates that, from a geotechnical standpoint, the parcel is suitable for the J proposed development provided the recommendations contained herein are properly followed. The foundation bearing stratum is relatively shallow and conventional spread footing ` foundations and standard pavement sections may be utilized. Consequently, foundations bearing on either the medium dense to dense, natural glacial sediments or on structural fill placed over these sediments are capable of providing suitable building support. 8.0 SITE PREPARATION 8.1 Clearing and Stripping Site preparation of the planned building area should include removal of all trees, brush, debris, and any other deleterious materials. These unsuitable materials should be properly disposed of off -site. Additionally, any areas of organic topsoil should be removed and the remaining roots grubbed. Areas where loose surficial soils exist due to grubbing operations should be considered as fill to the depth of disturbance and treated as subsequently recommended for structural fill placement. Any buried utilities should be removed or relocated if they are under the proposed building area. The resulting depressions should be backfilled with structural fill, as discussed under the "Structural Fill" section of this report. Any existing fill soils below footing areas should be stripped down to the underlying, medium dense to dense natural sediments. After stripping and grubbing operations have been completed, we recommend that the soil exposed in the proposed driveway and any other pavement areas be recompacted to a firm and unyielding condition. Any soft or yielding areas identified during compaction should be overexcavated and backfilled with structural fill. 8.2 Temporary Cut Slopes In our opinion, stable construction slopes should be the responsibility of the contractor and should be determined during construction based on the local conditions encountered at that time. For planning purposes, we anticipate that temporary, unsupported cut slopes in the medium dense to dense, weathered glacially consolidated sediments can be made at a maximum slope of 1.511:1V (Horizontal: Vertical). Temporary cut slopes within. the dense to very dense, unweathered lodgement till sediments can be planned up to a III: 1V inclination. As is typical with earthwork operations, some sloughing and raveling may occur, and cut slopes may have January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDH11d - EEOM59A5 - Projects120070659LMWP Page 10 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Preliminary Design Recommendations to be adjusted in the field. In addition, WISHA/OSHA regulations should be followed at all times. 8.3 Site Disturbance 1 The site soils contain a high percentage of fine-grained material, which makes them moisture - sensitive and subject to disturbance when wet. The contractor must use care during site preparation and excavation operations so that the underlying soils are not softened. If disturbance occurs, the softened soils should be removed and the area brought to grade with structural fill. If crushed rock is considered for the access and staging areas, it should be underlain by stabilization fabric (such as Mirafi 50OX or approved equivalent) to reduce the Jpotential of fine-grained materials pumping up through the rock and turning the area to mud. The fabric will also aid in supporting construction equipment, thus reducing the amount of crushed rock required. We recommend that at least 10 inches of rock be placed over the fabric; however, due to the variable nature of the near -surface soils and differences in wheel loads, this thickness may have to be adjusted by the contractor in the field. Crushed rock used f-� for access and staging areas should be of at least 2-inch size. 9.0 STRUCTURAL FILL Although final grading plans were not available to AESI at the time of this study, we anticipate �^ 1 that structural fill may be necessary to establish desired grades in some areas. All references 1 to structural fill in this report refer to subgrade preparation, fill type, and placement and compaction of materials, as discussed in this section. If a percentage of compaction is specified under another section of this report, the value given in that section should be used. j9.1 Subgrade Compaction tJ After overexcavation/stripping has been performed to the satisfaction of the geotechnical engineer/engineering geologist, the upper 12 inches of exposed ground should be recompacted l_J to a firm and unyielding condition. If the Subgrade contains too much moisture, suitable recompaction may be difficult or impossible to obtain and should probably not be attempted. CJIn lieu of recompaction, the area to receive fill should be blanketed with washed rock or quarry J spalls to act ,as a capillary break between the new fill and the wet Subgrade. Where the exposed ground remains soft and further overexcavation is impractical, placement of an O engineering stabilization fabric may be necessary to prevent contamination of the free -draining layer by silt migration from below. . After recompaction of the exposed ground is tested and approved, or a free -draining rock course is laid, structural fill may be placed to attain desired grades. January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. (� JDH/ld - EE070659A5 - Projects1200706591EE1WP page 1 I Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Preliminary Design Recommendations 9.2 Keying and Benching All structural fills planned to be placed on existing slopes steeper than 20 percent are required to have a keyway constructed at the toe of the fill body and the slope to be benched prior to placing fill. The keyway should be excavated a minimum of 2 feet down into firm, dense, natural sediments and be a minimum of 8 feet in width. The width for the benches should be established in the field to fit the contour and gradient of the slope being filled. 9.3 Structural Fill Compaction Structural fill is defined as non -organic soil, acceptable to the geotechnical engineer, placed in r I maximum 8-inch loose lifts, with each lift being compacted to at least 95 percent of the modified Proctor maximum dry density using American Standard for Testing and Materials (ASTM):D 1557 as the standard. Roadway and utility trench backfill should be placed and (, compacted in accordance with applicable municipal codes and standards. The top of the compacted fill should extend horizontally a minimum distance of 3 feet beyond footings or 1 pavement edges before sloping down at an angle no steeper than 2H A V . Fill slopes should either be overbuilt and trimmed back to final grade or surface -compacted to the specified density. 9.4 Moisture -Sensitive Fill C Soils in which the amount of fine-grained material (smaller than No. 200 sieve) is greater than approximately 5 percent (measured on the minus No. 4 sieve size) should be considered moisture -sensitive. Use of moisture -sensitive soil in structural fills should be limited to [, favorable dry weather conditions. The on -site soils contain significant amounts of silt and are considered moisture -sensitive. Construction equipment traversing the site when the. soils are very moist or wet can cause considerable disturbance. If fill is placed during wet weather or if proper compaction cannot be obtained, a select import material consisting of a clean, free - draining gravel and/or sand should be used. Free -draining fill consists of non -organic soil with (� the amount of fine-grained material limited to 5 percent by weight when measured on the l J minus No. 4 sieve fraction. 9.5 Structural Fill Testin The contractor should note that any proposed fill soils must be evaluated by AESI prior to their Duse in fills. This would require that we have a sample of the material at least 3 business days in advance to perform a Proctor test and determine its field compaction standard. A representative from our firm should inspect the stripped subgrade and be present during placement of structural fill to observe the work and perform a representative number of in - place density tests. In this way, the adequacy of the earthwork may be evaluated as filling hl January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. nJDHRd - M70659A5 - Projects120070659LMWP Page 12 lJ I Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Preliminary Design Recommendations progresses and any problem areas may be corrected at that time. It is important to understand that taking random compaction tests on a part-time basis will not assure uniformity or acceptable performance of a fill. As such, we are available to aid the owner in developing a suitable monitoring and testing frequency. . 10.0 FOUNDATIONS I 1'10.1 Allowable Soil Bearing Pressure Spread footings may be used for building support when founded either directly on the medium dense to very dense, natural glacial sediments, or on structural fill placed over these materials, as described under the "Site Preparation" and "Structural Fill" sections of this report. For l� footings founded either directly upon the medium dense to very dense glacial sediments, or on structural fill as described above, we recommend that an allowable bearing pressure of 2,000 pounds per square foot (pso be used for design purposes, including both dead and live loads. r l An increase of one-third may be used for short-term wind or seismic loading. If structural fill I) . is placed below footing areas, the structural fill should extend horizontally beyond the footing edges a distance equal to or greater than the thickness of the fill. 10.2 Footing Depths LI Perimeter footings for the proposed building should be buried a minimum of 18 inches into the J surrounding soil for frost protection. No minimum burial depth is required for interior footings; however, all footings must penetrate to the prescribed stratum, and no footings should be founded in or above loose, organic, or existing fill soils. We recommend that an . evaluation of the foundation subgrade be performed prior to placement of concrete. At the location of both exploration pits, located in the area of the proposed home, sediments suitable [, for foundation support were encountered at a depth of approximately 1.5 to 2.5 feet below the existing ground surface. The distribution and thickness of unsuitable colluvium sediments may not be uniform throughout the site, and overexcavation of some footing areas may be expected. �l Furthermore, foundations on the west side must be deep enough to allow a setback of 15 feet where that elevation would daylight on the slope. a 10.3 Footings Adjacent to Cuts s The area bounded by lines extending downward at 1H:1V from any footing must not intersect another footingor intersect a filled area that has not been compacted to at least 5 p 9 percent of ASTM:D 1557. In addition, a 1.5H:1V line extending down from any footing must not daylight because sloughing or raveling may eventually undermine the footing. Thus footings should not be placed near the edges of steps or cuts in the bearing soils. 1.1 . January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JoHad - EW70659n5 - ProJec1s120070659LMWP Page 13 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Preliminary Design Recommendations 10.4 Footing Settlement Anticipated settlement of footings founded as described above should be on the order of 1 inch or less. However, disturbed soil not removed from footing excavations prior to footing placement could result in increased settlements. 10.5 Footing Subgrade Bearing Verification All footing areas should be observed by AESI prior to placing concrete to verify that the exposed soils can support the design foundation bearing capacity and that construction conforms with the recommendations in this report. Foundation bearing verification may also be required by the governing municipality. 10.6 Foundation Drainage r Perimeter footing drains should be provided, as discussed under the "Drainage t , Considerations" section of this report. 1. 1 11.0 LATERAL WALL PRESSURES All backfill behind walls or around foundations should be placed following our recommendations for structural fill and as described in this section of the report. Horizontally backfilled walls, which are free to yield laterally at least 0.1 percent of their height, may be designed using an equivalent fluid equal to 35 pounds per cubic foot (pcf). Fully restrained, horizontally backfilled, rigid walls that cannot yield should be designed for an equivalent fluid of 50 pcf. Walls that retain sloping backfill at a maximum angle of 60 percent should be designed for 55 pcf for yielding conditions and 75 pcf for restrained conditions. If parking areas or driveways are adjacent to walls, a surcharge equivalent to 2 feet of soil should be added to the wall height in determining lateral design forces. 11.1 Wall Backfill The lateral pressures presented above are based on the conditions of a uniform backfill consisting of either the on -site glacial sediments or imported sand and gravel compacted to 90 to 95 percent of ASTM:D 1557. A higher degree of compaction is not recommended, as this will increase the pressure acting on the walls. A lower compaction may result in unacceptable settlement behind the walls. Thus, the compaction level is critical and must be tested by our firm during placement. The recommended compaction of 90 to 95 percent of ASTM:D 1557 applies to any structural fill placed behind the wall within a distance equal to the wall height and up to the elevation of the top of the wall. Structural fill used to construct January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. !DH/[d - EE070659A5 - Projecrs1200706591EE1WP Page 14 Subsurface Exploration, Geologic Hazard, and i Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Preliminary Design Recommendations ( slopes above retaining walls should be compacted to at least 95 percent of ASTM:D 1557 if the fill is placed above the elevation of the top of the wall. Surcharges from adjacent footings, heavy construction equipment, or sloping ground must be added to the above -recommended lateral pressures. Footing drains should be provided for all retaining walls, as discussed under the "Drainage Considerations" section of this report. 11.2 Passive Resistance and Friction Factor l Lateral loads can be resisted by friction between the foundation and the natural, medium dense 1 J to dense glacial sediments or supporting structural fill soils, or by passive earth pressure acting on the buried portions of the foundations. The foundations must be backfilled with compacted �) structural fill to achieve the passive resistance provided below. We recommend the following allowable design parameters: [� • Passive equivalent fluid = 300 pcf l • Coefficient of friction = 0.35 ll 12.0 FLOOR SUPPORT Slab -on -grade floors may be constructed either directly on the medium dense to dense natural sediments, or on structural fill placed over, these materials. Areas of the slab subgrade that are disturbed (loosened) during construction should be recompacted to an unyielding condition prior to placing the pea gravel, as described below. If moisture intrusion through slab -on -grade floors is to be limited, the floors should be constructed atop a capillary break consisting of a minimum thickness of 4 inches of washed pea gravel. The pea gravel should be overlain by a 10-mil (minimum thickness) plastic vapor retarder. 13.0 DRAINAGE CONSIDERATIONS j� The natural glacial sediments encountered in our explorations generally contained significant Ll amounts of silt and are considered to be highly moisture -sensitive. Traffic from vehicles, construction equipment, and even foot traffic across these sediments when they are very moist n or wet will result in disturbance of the otherwise firm stratum. Therefore, prior to site work �J and construction, the contractor should be prepared to provide drainage and subgrade n protection, as necessary. L1 January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. nJDHIld - EE070659A5 - Projects120070659iMUP Page 15 l_i Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Preliminary Design Recommendations r I 13.1 Wall/Foundation Drains All retaining and perimeter footing walls should be provided with a drain at the footing elevation. The drains should consist of rigid, perforated, polyvinyl chloride (PVC) pipe surrounded by washed pea gravel. The level of the perforations in the pipe should be set approximately 2 inches below the bottom of the footing, and the drains should be constructed with sufficient gradient to allow gravity discharge away from the building. All retaining walls should be lined with a minimum, 12-inch-thick, washed gravel blanket provided to within 1 foot of finish grade, and which ties into the footing drain. Roof and surface runoff should not discharge into the footing drain system, but should be handled by a separate, rigid, tightline drain. Exterior grades adjacent to walls should be sloped downward away from the structure to achieve surface drainage. Final exterior grades should promote free and positive drainage away from the building at all times. Water must not be allowed to pond or to collect adjacent to the foundation or within the immediate building area. It is recommended that a gradient of at least 3 percent for a minimum distance of 10 feet from the building perimeter be provided, except in paved locations. In paved locations, a minimum gradient of 1 percent should be provided unless provisions are included for collection and disposal of surface water adjacent to the structure. Additionally, pavement subgrades should be crowned to provide drainage toward catch basins and pavement edges. 14.0 PROJECT DESIGN AND CONSTRUCTION MONITORING We are available to provide additional geotechnical consultation as the project design develops and possibly changes from that upon which this report is based. The recommendations in this report are considered to be preliminary because grading plans and construction details were not finalized at the time of this study. If significant changes in grading are made, we recommend that AESI perform a geotechnical review of the plans prior to final design completion. In this way, our earthwork and foundation recommendations may be properly interpreted and implemented in .the design. We are also available to provide geotechnical engineering and monitoring services during construction. The integrity of the foundations depends on proper site preparation and construction. procedures. In addition, engineering decisions may have to be made in the field in the event that variations in subsurface conditions become apparent. Construction monitoring services are . not part of this current scope of work. If these services are desired, please let us know, and we will prepare a proposal. January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDH/ld - EE070659A5 - Projecu1200706591EEIWP Page 16 Subsurface Exploration, Geologic Hazard, and Proposed Edmonds Residence Preliminary Geotechnical Engineering Report Edmonds, Washington Preliminary Design Recommendations We have enjoyed working with you on this study and are confident that these recommendations will aid in the successful completion .of your project. If you should have any questions or 1 require further assistance, please do not hesitate to call. Sincerely, 1 ASSOCIATED EARTH SCIENCES, INC. Everett, Washington i� 1 H H Jon . Hansen Senior Staff Geologist Attachments: Figure 1: Vicinity Map Figure 2: Site and Exploration Plan Appendix: Exploration Logs ✓0 Matthew A. Miller, P.E. Associate Engineer January 25, 2008 ASSOCIATED EARTH SCIENCES, INC. JDH/!d - EE070659A5 - Projects1200706591EEw Page 17 ~20.mr_` SCALE IN FEET Reference: Untitled Map from John L. Scoft FIGURE 2 Associated Earth Sciences, Inc. SITE AND EXPLORATION PLAN DATE 1/08 PROPOSED EDMONDS RESIDENCE APPENDIX i •o ° Well -graded gravel and Terms Describing Relative Density and Consistency ID o00o GW gravel with sand, little to Density SPTr4blows/foot j H LL o no fines Coarse Very Loose 0 to 4 > > ae O C) to e 0,o o 0 0 0 o Poorly -graded 9 Poorl - raded ravel Grained Soils Loose 4 to 10 Test Symbols Medium Dense 10 to 30 Y rn 0 00000 GP and gravel with sand, Dense 30 to 50 I oo 0 000 little to no fines Very Dense >50 G =Grain Size N 6 o Z o c 0000 0 0 o M= Moisture Content Consistency SPT(2)blows/foot A = Atterberg Limits IZ 1n 0 c v Silty gravel and silty Very Soft 0 to 2 C=Chemical c o GM gravel with sand Fine- Soft 2 to 4 DD = Dry Density m m m Grained Soils Medium Stiff 4 to 8 K= Permeability g Stiff 8 to 15 I0 Clayey gravel and very stiff 15 to 30 > r>t GC clayey gravel with sand Hard >� �"' Component Definitions ID Well -graded sand and Descriptive Term Size Range and Sieve Number Ia o SW sand with gravel, little Boulders Larger than 12• m } `o r P y to no fines Cobbles 3' to 12' Gravel 3' to No. 4 (4.75 mm) Iy m > in Poorly -graded sand Coarse Gravel 3' to 3/4' U T vu ' • SP and sand with gravel, Fine Gravel 3/4' to No. 4 (4.75 mm) o � little to no fines Sand No. 4 (4.75 mm) to No. 200 (0.075 mm) 1 z Coarse Sand No. 4 (4.75 mm) to No. 10 (2.00 mm) Ic N Silty sand and Medium Sand No. 10 (2.00 mm) to No. 40 (0.425 mm) w o y SM silty sand with Fine Sand No. 40 (0.425 mm) to No. 200 (0.075 mm) v [D� �a H Op.. ' gravel Silt and Gay Smaller than No. 200 (0.075 mm) to LL I Clayey sand and (3) Estimated Percentage Moisture Content c M cc • SC clayey sand with gravel Percentage by Dry - Absence of moisture, U . Component Weight dusty, dry to the touch Silt, sandy silt, gravelly silt, Trace <5 Slightly Moist-me�ftible m o 'n ML silt with sand or ravel g Fe1/ 5 to 10 Little 15 to 25 Moist - Damp but no visible > U) H m With - Non -primary coarse water m w Clay of low to medium constituents: > 15% Very Moist - Water visible but o Cn v °; plasticity; silty, sandy, Or Fines content between not free draining Z q = CL gravelly clay, lean Clay 5% and 15% Wet - Visible free water, usually Im E from below water table 1 a _ Organic clay or silt of low Symbols OL plasticity Blows/6" or o Sampler portion of 6' Cement grout o Elastic Type surface seal silt, Clayey silt, silt 2 0' OD „ Sampler Type e .. MH with micaceous or Description Bentorrite Split Spoon „ tit seal C. rn m o diatomaceous fine sand or Sampler 3.0' OD Split -Spoon Sampler - Filterckwith o o silt Clay of high plasticity, (SPA 3.25' OD Split -Spoon Ring Sampler t.l ; blank casing a� Ca c r CI sandy or gravelly clay, fat section Bulk sample - 3.0' OD Thin -Wall Tube Sampler =� casing c m E clay with sand or gravel (ncludin Shel tube or hwro� g ) with filler Pack (? yr n , Grab Sample • End cap c Organic clay or silt of 9 Y O Portion not recovered tL OH medium to high ttI laI Percentage by dry weight Depth of ground water plasticity fn (SPT) Standard Penetration Test 1 ATO = At time of drilling ,, c y Peat, muck and other. (ASTM D-1586) jZ Static water level (date) �1 In General Accordance with :E o, o PT highly organic soils Standard Practice for Description (S) Combined USCS symbols used for = cn O and Identification of Soils (ASTM D-2488) fines between 5% and 15% Classifications of soils in this report are based on visual field and/or laboratory observations, which include density/consistency, moisture condition, grain size, and plasticity estimates and should not be construed to imply field or laboratory testing unless presented herein. Visual -manual and/or laboratory classification methods of ASTM D-2487 and D-2488 were used as an identification guide for the Unified Soil Classification System. --. Associated Earth Sciences, Inc. EXPLORATION LOG KEY FIGURE Al LOG OF EXPLORATION PIT NO. EP-1 ii s This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named Project and should be together that for interpretation. This summary applies only to the location of this trench at the C read with report complete time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION Topsoil Loose, moist, brown to dark brown, silty fine SAND, little gravel, few organics. 1 Weathered Vashon Lodgement Till 2 Medium dense, moist to very moist, brown, silty fine SAND, little gravel. 3 Vashon Lodgement Till 4 Medium dense to dense, moist to very moist, gray, silty fine SAND, little gravel, mottled from 3.5 to 6 feet bgs. 5 Grades to dense, very moist, gray, silty fine SAND, with few medium SAND interbeds, little gravel, 6 trace cobbles. 7 8 9 10 11 12 13 14 15 Bottom of exploration pit at depth 14 feet No caving. Minor seepage at 11 feet bgs. Roots to 3 feet. 16 17 18 19 co s N Proposed Edmonds Residence Edmonds, WA Associated Earth Sciences, Inc. Project No. EE070659A 8 Logged by: JH n m : Approved by: FA LM W RN 0 1/9/08 CL LOG OF EXPLORATION PIT NO. EP-2 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION Topsoil Loose, very moist to wet, dark brown, fine sandy SILT, little gravel, few organics. 1 Colluvium Loose to medium dense, very moist to wet, mottled gray to bluish gray, silty fine SAND, little gravel, 2 trace organics. Vashon Lodgement Till 3 Medium dense to dense, very moist to wet, gray, silty fine SAND, with trace medium SAND interbeds, little gravel, trace cobbles, mottled from 2 to 4 feet. 4 5 6 7 8 9 10 11 Bottom of exploration pit at depth 10 feet Exploration terminated due to caving. Slight caving at 4 feet. Moderate seepage at 4 feet. Roots to 1 foot. 12 13 14 15 16 17 18 19 C3 lJ m Proposed Edmonds Residence r Edmonds, WA Associated Earth Sciences Inc. 1 8 Logged by: JH Project No. EE070659A . rl a Approved by: .' 119/08 Il)I Y Associated Fa rth Sciences, Inc. RE NJ W a t Ce(�rafiry a vr25 V afsaf S'esdce Junk 24, 2008 Project No. EE070659B Interbay Properties, LLC 1445 NW 186`h Street Shoreline, Washington 98177 Attention: Mr. Darryl Lewis Subject: Rockery Design Proposed Residence 1142 Sierra Place Edmonds, Washington Dear Mr. Lewis: 4 A,- M 1 APR 012009 As requested, Associated Earth Sciences, Inc. (AESI) is pleased to provide this letter presenting our geotechnical engineering recommendations for construction of rockeries at the above -referenced site. AESI has previously completed geotechnical explorations on the site as part of a geotechnical study. The report was titled "Subsurface Exploration, Geologic Hazard, and Preliminary Geotechnical Engineering Report, Proposed Edmonds Property, Edmonds, Washington", dated January 25, 2008. AESI used the information in the above referenced report to design both cut and fill rockeries for the subject property. ROCKERY RECOMMENDATIONS Rockeries may be used to prevent erosion of cut slopes in dense, natural soils. Unreinforced rockeries are not engineered structures and should not be used in place of retaining walls. Rockeries facing structural fill greater than 3 feet high require the inclusion of geogrid at specified elevations, as shown on the attached plan sheet to function as intended. Structures and pavement should be set back from rockeries so that a 1H:1V (Horizontal: Vertical) line extending up from the rear base of the rockery does not intersect a structure footing. The rockeries were designed to include a 250-pounds-per-square-foot (psf) surcharge to account for traffic loading conditions. A geotechnical engineer should observe foundation conditions, placement of drainage aggregate, and, where applicable, placement of structural fill to confirm that construction of the rockery is in general accordance with the recommendations presented herein. Kirkland Everett Tacoma 425-827-7701 425-259-0522 253-722-2992 www.aesgeo.com The following notes present rockery construction recommendations. Rockery details for rockeries constructed against native soils and for rockeries constructed against reinforced fills are shown on the attached plan sheet. In addition, the contractor should confirm that his configurations conform to current City of Edmonds specifications. • The base of the rockery should be started by excavating a trench to a minimum depth of 12 inches below subgrade into firm, unyielding ground. If loose, soft, existing fill or disturbed materials exist at the base rock location, they should be removed and replaced with free -draining sand and gravel or crushed rock. This backfill material should be compacted to a minimum of 90 percent of the modified Proctor maximum density using American Society for Testing and Materials (ASTM):D 1557 as the standard. • The base rock should have a minimum width (perpendicular to the line of the rockery) of 40 percent of the height of the rockery. All rocks should also meet the following weight requirements: Height of Rockery Minimum Weight of Rock Above 5 feet 500/2,200 pounds, graded, top/bottom rocks 5 feet or less 50011,000 pounds, graded, top/bottom rocks • The rock material should all be as nearly rectangular as possible. No stone should be used that does not extend through the wall. The rock material should be hard, sound, durable, and free from weathered portions, seams, cracks, or other defects. The rock density should be a minimum of 160 pounds per cubic foot (pcf). • Rock selection and placement should be such that there will be minimum voids, and in the exposed face of the wall, no open voids over 8 inches across in any direction. The rocks should be placed in a manner such that the longitudinal axis of the rock will be at right angles or perpendicular to the rockery face. Each rock should be placed so as to lock into two rocks in the lower tier. After setting each rock course, all voids between the rocks should be chinked on the back with quarry rock to eliminate any void sufficient to pass a 2-inch square probe. • A drain consisting of rigid, perforated, polyvinyl chloride (PVC) pipe bedded in a 12-inch-wide, pea gravel trench should be placed behind the lower course of rock to remove water and prevent the buildup of hydrostatic pressure behind the rockery. The remainder of the rockery backfill (for cut rockeries) should consist of quarry spalls with a maximum size of 4 inches and a minimum size of 2 inches. This material should be placed to a 12-inch minimum thickness behind the entire rockery. The backfill material should be placed in lifts to an elevation approximately 6 inches below the top of each course of rocks as they are placed until the uppermost course is placed. Any backfill material falling onto the bearing surface of a rock course should be removed before the setting of the next course. 2 • Rockeries facing structural fill should include a chimney drain, as shown on the plan sheet. A chimney drain is hydraulically connected to the drain system, runs under the structural fill, and extends two-thirds of the total height of the rockery. Drainage aggregate for the drains should consist of granular, free -draining clean, crushed rock with less than S percent fines by volume. • Any asphalt paving or final lot grades should be sloped to drain away from the rockery. In addition, the areas above rockeries should be permanently protected from erosion as soon as possible after rockery construction. • A geotechnical engineer must observe foundation conditions, placement of drainage aggregate, and, where applicable, placement of structural fill to confirm that construction of the rockery is in general accordance with the plans and specifications. We trust that the wall design details will aid in the successful completion of the project. If there are questions regarding the wall design, please contact us. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Everett, Washington Edwardo Garcia, P.E. Project Engineer Attachment: Plan Sheet EG/dr EE070659B5 Projects\20070659\EE\W P YNEW A. ti )284 TERE G�� 2 oS AL t-x? 'z-X-.O Matthew A. Miller, P.E. Associate Engineer Ke M MSEW -- Mechanically Stabilized Earth Walls Present Date rime: Thu Jun 26 14:53:24 2008 1142 Sierra Place, Edmonds Z:\01Projeas\07s\070659 Interbay Rockery\EE070359B reinf rockery pegriM.BEN Assoc at %d Earth ,Sciences,. Inc. M a 1.4 . ,LAM AASHTO DESIGN METHOD 1142 Sierra Place, Edmonds PROJECT IDENTIFICATION Title: 1142 Sierra Place, Edmonds Project Number: EE070659B Client: Interbay Properties LLC Designer: EX Station Number: Description: Geogrid Reinforced Rockery up to 5-ft max height. Geogrid to be at Length Company's information: Name: Associated Earth Sciences, Inc. Street: 911 Fifth Avenue Kirkland, WA 98033 Telephone #: 425.827.7701 Fax #: 425.827.5424 E-Mail: elim@aesgeo.com Original file path and name: Z:\O1Projects\07s\070659 Interbay Rockery\EE070359B rei..... ..... rockery pegrid4.BEN Original date and time of creating this file: Thu Jun 26 14:09:40 2008 PROGRAM MODE: ANALYSIS of a SIMPLE STRUCTURE using GEOGRID as reinforcing material. 1142 Sierra Place, Edmonds Copyright m 1998-2006 ADAMA Engineering, Inc. Page 1 of 5 License number MSEW-301043 MSEW -- Mechanically Stabilized Earth Walls 1142 Sierra Place, Edmonds Present Date rime: Thu Jun 26 14:53:24 2008 Z:\01Projects\07s\070659 Interbay Rockery\EE070359B roinf rockerypegid4.BEN JJ Yi6MVmJe10aM Vaia10YIIJIVmJJY)[MVm).OYSV V�aJJY)lV V�vfa YtFM Vas�l.JY6EW Vie JJ W[M V�o 10YIIV/Vatln JL MS6M Via JYJiM Vain)< YJ6N Vciw JJdlM �.la ab ) MJA' �y SOII.DATA REINFORCED SOIL Unit weight, y 130.0 lb/ft 3 Design value of internal angle of friction, 34.00 RETAINED SOIL Unit weight, y 130.0 lb/ft 3 Design value of internal angle of friction, 34.00 FOUNDATION SOIL (Considered as an equivalent uniform soil) Equivalent unit weight, y egniv. 130.0 lb/ft 3 Equivalent internal angle of friction, �epiv. 34.00 Equivalent cohesion, c equiv. 0.01b/ft Z Water table does not affect bearing capacity LATERAL EARTH PRESSURE COEFFICIENTS Ka (internal stability) = 0.2827 (if batter is less than 10°, Ka is calculated from eq. 15. Otherwise, eq. 38 is. utilized) Inclination of internal slip plane, W= 62.000 (see Fig. 28 in DEMO 82). Ka (external stability) = 0.3979 (if batter is less than 100, Ka is calculated from eq. 16. Otherwise, eq. 17 is utilized) BEARING CAPACITY Bearing capacity coefficients (calculated by MSEW): Nc = 42.16 N y= 41.06 SEISMICITY Note: specified a combined with I and &roduced a square root of -0.05 in eq. 37a. MSEW set this square root to ZERO so that the Kae could be calculated. Be aware that the end results are likely erroneous and ARE PROVIDED FOR INFORMATION ONLY Maximum ground acceleration coefficient, a n = 0.160 Kae ( a.> 0) = 1.1035 Kae ( as 0) = 0.3979 0 Kae = 0.7056 (see eq. 37 in DEMO 82) Seismic soil-geogrid friction coefficient, F* is 80.0% of its specified static value. 1142 Sierra Place, Edmonds Page 2 of 5 Copyright 0 1998-2006 ADAMA Engineering, Inc. License number MSEW-301043 MSEW -- Mechanically Stabilized Earth Walls 1142 Sierra Place, Edmonds Present DatefMw: Thu Jun 2614:53:2200 4 8 ZAO1Projecta\07M70659 Interbay Rockery1EE070359B reinf rockerypeVW4.BEN r.a„m.rrs,. INPUT DATA: Geogrids (Analysis) D A T A Geogrid Geogrid Geogrid Geogrid Geogrid type #1 type #2 type #3 type #4 type #5 Tult [lb/ftj 4200.0 Durability reduction factor, RFd 1.10 Installation -damage reduction factor, RFid 1.22 Creep reduction factor, RR 1.60 N/A N/A N/A N/A Fs -overall for strength N/A Coverage ratio, Rc 1.000 Friction angle along geogrid-soil interface, p 29.80 Pullout resistance factor, F* 0.80•ta4 N/A N/A Scale -effect convection factor, a 1.0 Variation of Lateral Earth Pressure Coefficient With Depth Z K / Ka 0.0 1.0 0 ft 1.00 3.3 ft 1.00 Z [ft] 6.6 ft 1.00 9.8 ft 1.00 13.1 ft 1.00 16.4 ft 1.00 19.7 ft 1.00 32.8 N/A N/A K/Ka 2.0 3.0 1142 Sierra Place, Edmonds Page 3 of 5 Copyright 0 1998-2006 ADAMA Engineering, Inc. License number MSEW-301043 MSEW -- Mechanically Stabilized Earth Walls 1142 Sierra Place, Edmonds Present me: DatefriThu Jun 26 14:53:24 2008 ZA01ProjectM7s\0706591nterbsy Rockery4EE070359B reinfrockety pegrid4.BEN 1pYIIM VSY3e Y]f1/V�i A14IIV/V�elp Mf]M V�e]IYYMVw1a ApYRMVm_ pY]FM Vein LY.>E•.'VY.s3p YQVIVm3p4]CM vs.Ynlp4S[MV via YVI A M4.v wb MSA' MI[MV , M]Ev , M3A' tia ! INPUT DATA: Geometry and Surcharge loads (of a SUAPLE STRUCTURE) Design height, Hd 5.00 [ft] { Embedded depth is E = 1.00 ft, and height above top of finished bottom grade is H = 4.00 ft } Batter, w 0.0 [deg] Backslope, Q 26.0 [deg] Backslope rise 20.0 [ft] Broken back equivalent angle, I = 26.000 (see Fig. 25 in DEMO 82) UNIFORM SURCHARGE F-77- 77 Uniformly distributed dead load is 0.0 [lb/ft 1], and live load is 250.0 [lb/ft 2] SCALE: 0 2 4 6 [ft] 1142 Sierra Place, Edmonds Page 4 of 5 Copyright m 1998-2006 ADAMA Engineering, Inc. License number MSEW-301043 3 MSEW -- Mechanically Stabilized Earth Walls 1142 Sierra Place, Edmonds Present Duelfime: Thu lun 2614:53:24 2008 Z\01 Projects\07M706591nterbay Rockery]EE070359B reinf rockery pcgrid4.BEN Vda U)O[V Vda WWV A dal lRW UY)EW VdaI 1]lry Vda MGM Vda Vda da) MpWVwI.] V - A YIIW- - M9WVda Y¢W daA f[W da UMIIW l ]]QW Y)A' l]IIW ANALYSIS: CALCULATED FACTORS (Static conditions) Bearing capacity, Fs = 15.36, Meyerhof stress = 1352 lb/ft2. Fnnnriatinn Tntprfarp• Ti:rnrt clirrina Rc = 7 1 77 Rrrantr:r:h] a/r = n nl 7n Fc_n,mrt,,...:.,.. = d AIZ GEOGRID CONNECTION Fs -overall Fs -overall Fs -overall Geogrid Pullout Direct Eccentricity Product # Elevation Length Type [pullout [connection [geogrid strength resistance sliding e/L name IN IN # resistance] break] strength] Fs Fs Fs 1 0.00 8.00 1 N/A N/A N/A 9.587 38.239 1.849 0.0170 Synteen SF55 2 1.50 8.00 1 N/A N/A N/A 5.653 16.484 1.957 -0.0168 Synteen SF55 3 3.00 8.00 1 N/A N/A N/A 7.428 14.809 2.039 -0.0568 Synteen SF55 4 4.50 8.00 1 N/A N/A N/A 12.517 15.271 2.009 -0.1193 Synteen SF55 ANALYSIS: CALCULATED FACTORS (Seismic conditions) Bearing capacity, Fs = 10.84, Meyerhof stress = 1642 lb/ft2. Rnnndat:nn Tntorf-- Tl:rnrt I;Ain. P. = 1 don Arrantriraftl a/T = n n011 Fe_mmrt„r.,:.... — '2 n4 GEOGRID CONNECTION Fs -overall Fs -overall Fs -overall Geogrid Pullout Direct Eccentricity Product # Elevation Length Type [pullout [connection [geogrid strength resistance sliding e/L name [ft] [ft] # resistance] break] strength] Fs Fs Fs 1 0.00 8.00 1 N/A N/A N/A 7.879 22.712 1.265 0.0913 Synteen SF55 2 1.50 8.00 1 N/A N/A N/A 5.069 11.136 1.487 0.0223 Synteen SF55 3 3.00 8.00 1 N/A N/A N/A 6.547 9.749 1.769 -0.0427 Synteen SF55 4 4.50 8.00 1 N/A N/A N/A 10.444 9.273 1.979 -0.1182 Synteen SF55 VaLUA46W VW U16EY Vda UY1[W Vda)AY)EW Vdr U,IJEW Vs 1416]W Vda)A16AW Vda UIJ]AW Vi1416FW Vi UllffW VmY]UM1EW Vda UII)EW Vda Ul66W VM�IAH)RW Vda]AYlAW VdalA4ffW Vda14--U)ISA' V®U11f[W Vd---V®lA--lA 1142 Sierra Place, Edmonds Page 5 of 5 Copyright ® 1998-2006 ADAMA Engineering, Inc. License number MSEW-301043 AN 2/3 H (CRUSHED J 5% FINES F MIN MIN V WIDE LAYER V MIN NT OF 2"-4" QUARRY TYP :R SPALLS ADJACENT 3 OR FLATTER (UAL TO ROCKERY TYP 1 16" MIN X 1 io 6 x H 2 (7 w .x / 12" TYP NO ROADWAY, PARKING LOTS, OR BUILDING FOOTINGS IN THIS AREA r 2 OR FLATTER i i i i 16" MIN i i CD 6 2 j i w 1 x STABLE CUT FACE IN NATURAL MATERIAL -TYP SEE NOTE 5 MIN 4" DIAMETER PERFORATED RIGID PVC PIPE WITH 6" COVER AND 2" BEDDING OF 1" WASHED ROCK - PROVIDE MIN 1 % CONTINUOUS MIN 4" DIAMETER PERFORATED RIGID PVC PIPE WITH 6" COVER AND 2" BEDDING OF 1" WASHED ROCK - PROVIDE MIN 1 % CONTINUOUS SLOPE TO APPROVED OUTLET FIRM UNDISTURBED SOIL -TYP SEE NOTE 2 NO WALLS, ROCKERIES, OR FOOTINGS IN THIS AREA 1' MIN j 2 OR FLATTER 1 / / / / / 1 6 H w rn 12" FIRM UNDISTURBED SOIL SEE NOTE 2 MIN 1' WIDE LAYER OF 2"-4" QUARRY SPALLS ADJACENT TO ROCKERY STABLE CUT FACE IN NATURAL MATERIAL SEE NOTE 5 MIN 4" DIAMETER PERFORATED RIGID PVC PIPE WITH 6" COVER AND 2" BEDDING OF 1" WASHED ROCK - PROVIDE MIN 1 % CONTINUOUS SLOPE TO APPROVED OUTLET TYPICAL UNREINFORCED ROCKERY DETAIL NOT TO SCALE rn n 0 NO WALLS, ROCKERIES, OR FOOTINGS IN THIS AREA / V MIN / MIN V WIDE LAYER 2 OR FLATTER OF 2"-4" QUARRY 1 F / SPALLS ADJACENT / TO ROCKERY i STRUCTURAL FILL COMPA i TO 95% OF ASTM D-1557 FIRM UNDISTURBED SOIL OR STRUCTURAL FILL SEE NOTE 2 / /1 / 12" THICK CHIMNE FREE DRAINING C Z_ f _ -- ROCK WITH LESS' — — L = H+Z 6" / 1.5' TYP —MIN 3'—� 999 kml GEOGRID REINFORC LAYERS MIRAGRID 5) ENGINEER APPROVE TYP MIN 4" DIAMETER PERFORATED RIGID PVC PIPE WITH 6" COVER AND 2" BEDDING OF 1" WASHED ROCK PROVIDE MIN 1 % CONTINUOUS SLOPE TO APPROVED OUTLET GEOGRID REINFORCED ROCKERY DETAIL NOT TO SCALE NO WALLS, ROCKERIES, OR FOOTINGS IN THIS AREA I'MIN i 2 OR FLATTER / 1 F— / i / / / / MIN 1' WIDE LAYER OF 2"-4" QUARRY SPALLS ADJACENT TO ROCKERY STABLE CUT FACE IN NATURAL MATERIAL SEE NOTE 5