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20040828.pdfDATE RECEIVED CITY OF EDMONDS CONSTRUCTION PERMIT APPLICATION OWNER NAMEINAME OF BUSINESS MAILING ADDRESS NAME L- ADDRE�SS a: 4t NAME ZIP TELEPHONE 1�:,li - Llz� __V 2- k , I I zV ZIP ITELEPHONE -'+Nk%4 I )_ L L, V kl,% I (. -) q -) \ V,:) WL ADDRESS CBL 0 C CITY ZIP TELEPHONE STATE LICEASE NUMBER EXPIRATION DATE CHECKED BY PROPERTY TAX ACCOUNT PARCEL NO. I qsco) - 4 -000­11 NEW RESIDENTIAL PLUMBING / MECH 7­ El ADDITION COMMERCIAL COMPLIANCE OR CHANGE OF USE 13 REMODEL MULTIFAMILY SIGN 1:1 REPAIR GRADING 19i CYDS FENCE I X FT) 1:1 DEMOLISH TANK OTHER �GARAGE Et Cnmfqm�x RETAINING WALL ROCKERY FIRE SPRINKLER FIRE ALARM (TYPE OF USE, BUSINESS OR ACTIVITY) EXPLAIN: I c-) F' fk� NUMBER OF L- NUMBER OF DWELLING I z CRITICAL AREAS 0 /7) 4V STORIES UNITS NUMBER/")/V— DESCRIBE WORK TO BE DONE I PE RMIT EXPIRES USE PERMIT ZONE NUMBER JOB ADDRESS ML PLAT NAMEI;UBDIVISION NO. LOT NO. W PUBLIC RIGHT OF WAY PER OFFICIAL STREET MAP EXISTING - PROPOSED REQUIRED DEDICATION Fr METER SIZE TL17NE SIZE NO. OF FIXTURES 17 SUITE/APT# LID NO. LID FEE S TESCP APPIOVOO RW Pe,mit Requited Spoel Use Permit Req'd jilspection Required sidewalk Rectijifed Undolground wiring gertuired YES REMARKS OWN ER/CON TRACTOR RESPONSIBLE FOR EROSION CONTROL/DRAINAGE F. a FIRE REVIEWED BY I DATE JIFIED NO 1:3 z z F3 Z LU LLI cc iE VARIANCWFI CU SHORELINE OR ADBN A P EQC.TION REqD,, BOND POSTED LINS ] S YES P�NO S SEPA F IEW COMPLETE EXEMPT SIGN AREA ALLOWED PROPOSED HEIGHT ALLOWED PROPOSED LOT COVERAGE ALLOWED PROPOSED REQUIRED SETBACKS (FT) FR SjDE RE�AFI PROPOSED SETBACKS (Fr.) FRqNT /UR S.PE R OK CC/- W �PNT 0 5' 1615. 16 �i5,, z z PARKING REO'D VID PRC� D LOT AREA b NNING REVIEWED BY DATE r� /0 L _E REMARKS P-00 -17,�, CHECKED BY TYPE OF gpNSTRUCTION I C.ODE OCCUPANT GR SPECIAL INS r AREA OCCUPANT/ REQUIRED WY LOAD � 0 REMARKS/ INSPECTIONS PER UBC 108/IBC1091IRC109 FINAL INSPECTION REQ'D z a ROGRESS j P -6 A'A 0 1 -/,"7 YCIS HEAT �kIOURCE GLAZING % IN SLqPE % "Q� ir /c, I PLAN CHEC�10* VESTED DATE ......... THIS PERMIT AUTHORIZES ONLY THE WORK NOTED. THIS PERMIT COVERS WORK TO BE DONE ON PRIVATE PROPERTY ONLY. ANY CONSTRUCTION ON THE PUBLIC DOMAIN (CURBS, SIDEWALKS, DRIVEWAYS, MARQUEES, ETC.) WILL REQUIRE SEPARATE PERMISSION. IL C11 Lu PERMIT APPLICATION: 180 DAYS PERMIT LIMIT I YEAR - PROVIDED WORK IS STARTED WITHIN 180 DAYS SEE BACK OF PINK PERMIT FOR MORE INFORMATION in 'APPLICANT, ON BEHALF OF HIS OR HER SPOUSE, HEIRS. ASSIGNS AND SUCCESORS V) !H IN INTEREST, AGREES TO INDEMNIFY, DEFEND AND HOLD HARMLESS THE CITY OF M EDMONDS, WASHINGTON, ITS OFFICIALS, EMPLOYEES. AND AGENTS FROM ANY AND ALL CLAIMS FOR DAMAGES OF WHATEVER NATURE. ARISING DIRECTLY OR INDIRECTLY FROM THE ISSUANCE OF THIS PERMIT. ISSUANCE OF 1HIS PERMIT SHALL NO] BE DEEMED TO MODIFY WAIVE OR REDUCE ANY REQUIREMENT OF ANY CITY ORDINANCE 0 NOR LIMIT IN ANY WAY THE CITYS ABILITY TO ENFORCE ANY CRDINANCE PROVISION." I HEREBY ACKNOWLEDGE THAT I HAVE READ THIS APPLICATION; THAT THE INFORMATION GIVEN IS CORRECT; AND THAT I AM THE OWNER, OR THE DULY AUTHORIZED AGENT OF THE OWNER. I AGREE TO COMPLY WITI I CITY AND STATE LAWS REGULATING CONSTRUC- TION; AND IN DOING THE WORK AUTHORIZED THEREBY. NO PERSON WILL BE EMPLOYED IN VIOLATION OF THE LABOR CODE OF THE STATE OF WASHINGTON RELATING TO WORKMEN'S COf�PENSATION INSURANCE AND RCW 18.27. SI �TTLRE (OWN�R OR kd?�T),' DATE SIGNED (ALLIATION ; 121 17 Description FEE Description FEE 31an Check State Surcharge 3uilding Permit City Surcharge 3lumbing Base Fee 1 EAechanical irading S radi n g Engr. Review Engr. Inspection Fire Review— Plan Chk. Deposit Fire Inspection Receipt # Landscapelnsp. Total Amt. Due Recording Fee Receipt # APPLICATION APPROVAL CALL This application is not a permit until signed by the Building official or his/tier Deputy: and Fees are paid. and FOR INSPECTION receipt is acknowledged in space provided. OFFICIALS SIGNATURE DATE (425) 771-0220 RELEASE" DATE / / - - A 11 1 1 / - I/ ATTENTION \'�CUPYA BUILDING OR STRUCTURE UNTILAFINAL IT IS UNLAWFlJLT0 USE OR 0 LL INSPECTION HAS BEEN MADE AND APPROVAL OR A CERTIFICATE OF OCCU- PANCY HAS BEEN GRANTED. UBC109/iBC110/IRC110. 09/03 PRESS HARD -YOU ARE MAKING 4 COPIES L-FILE YELI_CM-INbI­T_WU OWNER GOLD -ASSESSOR &A z 0 1 0 M --i _n W 3: 0 M C M 0 0 -40 0 C: -49 x rn M z _z 3: W 0 -n n -4 3:9 M M 0 0 0 M C: (/) 9 Cn M 0 Z 17, z W z 0 i 0 M 3 WATER & SEWER INSPECTIONS REQ'D. CALI. 425-771-0220 EXT. 1326 III - 0 A C 0 E !:` I'Al '-.3 'E -f IGHTLINE MATERIAL SDA 35 SCH 40 N - 12 ir-*81 0 HANCOR FOOTING DRAINS NOT, TO BE TIED INT6:!.�"" DETENTION SYSTEM %01 5f:mf'�%dm et 10'UTILIT'r— Ir Vxo'D EASEMENT_ Zone 4� Corner IV Flag IV �jcfbacks Emuired Actual ALL EXPOSED SURFACES TO Front 10 16 BE COVERED WITHIN 2 DAYS ___6- 7 Sides 13 7to I A1c_Cd1^,f1' �,,q Rear Other ,xv 4 I I wfi/ ADDRESS XXXX 210TH FLACELWO—It - - _\. /- ?�(q _IW6 Q1 VAI MAkNi'd NI T- ALLOWED 140/A\J- Ft4r- 01 44/0,'� 9*,q,,W10TH FLACE SN LOT I 5r=I=_ (�f=—Nr=R^L NOTES 5c:-,ALE. I"=20' /7 (y 'z 0 r-z LEOAL LOT 1, MADRONA COVE DESCRIPTION:. APPROVED Ry PLANNING 1 A/O SITE AREA: q06cl 5GUARE FEET ZONIN6,t . PLANNED UNIT DEVELOPMENT HEIrvHT CALCULATION (BASED FROM EX15TIN(S, ORADP) A= 40q' 5= 406.5' C = 412' .D= 411' 1655.5/4= 40q.625' AVERAOE EX15TINO &F;ZADE= 40q.625' ACTUAL BUILDINO Hr=1(3HT= 454.25' 4E MAXIMUM BUILDINO HEIOHT= 454.625' ,—' BENCHMAR-l< Hee,4_ EjeV'k_r:'1"'-\ ARFZAZI�� FOR HEIeHTVERIFI(�:,ATION) IMPERVIOUS AF:ZEAS RESIDENCE I^V 1-75-7 eGUARE FEET r-\/F:ZD PORCHEE) -NOTED DF;Zl\/EkqA'r5 400 5GUARE FEET ;VED AS PATIO 120 5GUAR-E FEET v-j,4c%21NEERING NALKVqA'7'5 (NE" 100 501JARE FEET'- WA .11?.41good TOTAL 2,55-7 SGUARE FEE-r0a0: tat C-1 LOT COVERAC-YE- ( LOT COVER'ArvE 15 BASED UPON 5591, OF ENTIRE PLANNED UNIT DEVELOPMENT) 1-75-7 50UARE FEEt OF PROP05ED LOT COVERACE (INCLUDES STRUCTURE, COVEF;ZED PORCHES, r.)Er-<S 0\/Ef;z 50") iv 2 000 4 y C I T Y& C GEOTECHNICAL ENGINEERING STUDY PEPPEFWOOD RESIDENTIAL DEVELOPMENT 8526 MAIN STREET z 0 EDMONDS, WASHINGTON 0 E-10075 0 M May 14, 2002 0 C PREPARED FOR z PHOENIX DEVELOPMENT, INC. vi 0 -n MM C/) 0 M C CD C Cn M 0 Z ;U z rE7R FS 7 CD z Raymond -A. Coglas, P.E. Project Manager M Earth Consultants, Inc. 1805 - 136th Place Northeast, Suite 201 Bellevue, Washington 98005 (206) 643-3780 Toll Free 1-888-739-6670 CITY IMPORTANT INFORMATION ABOUTYOUR GEOTECHNiCAL ENGINEERING REPORT More construction problems are caused by site subsur- face conditions than any other factor. As troublesome as Subsurface problems can be. their frequency and extent have been lessened considerably in recent years. due in large measure to programs and publiCaLions of ASFE/ The Association of Engineering Firms Practicing in tile Geosciences. The following suggestions and observations are olfered to help you reduce tile geotech n ical- related delays. cost -overruns and other costly headaches that can occur during a construction project. A GEOTECHNICAL ENGINEERING REPORT IS BASED ON A UNIOUE SET OF PROJECT -SPECIFIC FACTORS A geotechnical engineering report is based on a subsur- face exploration plan designed to incorporate a unique set of project -specific factors. These typically include: the general nature of the structure involved, its size and configuration; the location of the structure on the site and its orientation; physical concomitants such as access roads, parking lots, and underground utilities. and the level of additional risk which the client assumed by virtue of limitations imposed upon the exploratory program. To help avoid costly problems. consult tile geo ' technical engineer to determine how any factors which change subsequent to the date of tile report may affect its recommendations. Unless your consulting geotechnical engineer indicates otherwise, your geotechnical engineering report should not be used: • When the nature of the proposed structure is changed. for example, if an office building will be erected instead of a parking garage, or if a refriger- ated warehouse will be built instead of an unre- frigerated one; • when the si ze or con f igu ration of the proposed structure is altered; • when the location or orientation of tile proposed structure is modified: when there is a change of ownership. or • for application to an adjacent Site. Geotechnical engineers cannot accept responsibility for problems which may develop if they are not consulted after factors consid- ered in their report's development have changed. MOST GEOTECHNICAL "FINDINGS" ARE PROFESSIONAL ESTIMATES Site exploration identifies actual subsurface conditions only at those points where samples are taken, when they are taken. Data derived through sampling and sub- sequent laboratory testing are extrapolated by geo- technical engineers who then render an opinion about overall subsurface conditions. -their likely reaction to proposed construction activity, and appropriate founda- tion design. Even under optimal circumstances actual conditions may differ from those inferred to exist, because no geotechnical engineer, no matter how qualified, and no subsurface exploration program, no matter how comprehensive, can reveal what is hidden by earth, rock and time. The actual interface between mate- rials may be far more gradual or abrupt than a report indicates. Actual conditions in areas not sampled may differ from predictions. Nothing can be done to prevent the unanticipated, but steps can be taken to help minimize their impact. For this reason, most experienced owners retain their geotechnical consultants through the construction stage, to iden- tify variances, conduct additional tests which may be needed, and to recommend solutions to problems encountered on site. SUBSURFACE CONDITIONS CAN CHANGE Subsurface conditions may be modified by constantly - changing natural forces. Because a geotechnical engi- neering report is based on conditions which existed at the time of subsurface exploration, construction decisions should not be based on a geolechnical engineering report whose adequacy may have been affected by time. Speak with the geo- technical consultant to learn if additional tests are advisable before construction starts. Construction operations at or adjacent to the site and natural events such as floods. earthquakes or ground- water fluctuations may also affect subsurface conditions and. thus, the continuing adequacy of a geotechnical report. The geotechnical engineer should be kept apprised of any such events, and should be consulted to determine if additional tests are necessary. GEOTECHNICAL SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND PERSONS Geotechnical engineers� reports are prepared to meet the specific needs of specific individuals. A report pre- pared for a consulting civil engineer may not be ade- quate for a Construction contractor, or even some other consulting civil engineer. Unless indicated otherwise, this report was prepared expressly for the client involved and expressly for purposes indicated by the client. Use by any other persons for any purpose, or by the client for a different purpose, may result in problems. No indi- vidual other than the client should apply this report for its intended purpose without first conferring with the geotechnical engineer. No person should apply this report for any purpose other than that originally contemplated without first conferring with the geoiechnical engineer Z 0 4 0 M =i 9 C/) M 0 0 0 0 C —4 r. X M M Z C) -1 C Cn 0 -n n M M 0 0 0 M C Cn 9 C/) M 0 Z X Z Cn Z 0 1 0 M I Earth Consultants Inc. 1111olla sdenlists & i-twitot May 14, 2002 E-1 0075 Phoenix Development, Inc. P.O. Box 3167 Lynnwood, Washington 98046-0958 Attention: Ms. Loree Quade Dear Ms. Quade: We are pleased to submit our report titled "Geotechnical Engineering Study, Pepperwood, Residential Development, 8526 Main Street, Edmonds, Washington." This study presents the results of our field exploration and. geotechnical engineering analyses for the proposed residential development. Our scope of services for producing this study were outlined in our proposal PR-10075, dated March 1, 2002. Based on the results of our study, development of the site as planned is feasible from a geotechnical standpoint. Medium dense to very dense glacial till was observed at the test pit locations. Fill and yard waste materials were observed along the top of the existing slope areas along the upper half of the site at several of the test pit locations. The fill soils were observed to depths of approximately four to five feet. Based on the subsurface conditions observed at the test pit locations, it is our opinion the proposed single family residences can be supported on conventional spread and continuous footings bearing on the competent glacial till native soils, or on structural fill soils used to modify existing site grades. The existing slope areas throughout the middle of the site appear stable. Due to the dense condition of the native glacial till soils, the existing slope areas should not be adversely impacted by the proposed construction. In our opinion, the buffer requirements for building construction adjacent to steep slope areas can be reduced. Recomrnendations for setbacks and other geotechnical recommendations are presented in this geotechniGal engineering study. 1805 - 136th Place RE, Suite 201, Bellevue, Washington 98005 Bellevue (425) 643-3780 FAX (425) 746-0860 Toll Free (888) 739-6670 z 0 4 0 M --i -n M M 0 -10 0 C --I K % . , I M M M z J0 0 -n n M M 0 —Cn . I 0 F- 0 M C C/) 9 CD M 0 Z z Cn z 0 i 0 M I Phoenix Development May 14, 2002 E-10075 We appreciate the opportunity to provide our services during the design phase of the project. If you have questions about the content of this geotechnical engineering study, or if we can be of further assistance, please call. z Sincerely, 0 M ISULTANTS, INC. CO SULTAN EA CM "Cogla M :ond M 0 C A. E X M Project Manager M Z RACJJrne C —Z 0 -n 3: IT! M C) 0- r 0 M MCI), Q 0 Z X, 3:, �z Z' 0 0. 171 Earth Consultants, Inc. TABLE OF CONTENTS E-,10075 PAGE z INTRODUCTION a a 0 0 a 0 6 0 0 0 a 0 4 0 & 0 0 6 a 0 0 a a dead 0 General a a a a a a a a a 0 4 a 4 0 4 a a a a 0 0 a a a a a 4646004040 0 0 0 a a 0 a 4 0 4 0 4 a a a a of 4 @@seemed 04 a do 000 0 4 0 0 0 a 4 0 a a a 0 a 4 0 m Proigct Descripfions a 4 a a a a a a 0 a 4 a 0 4 4 0 a a 0 a 0 4 a a 9 a a a 0 a 4 a a a a a a 4 a a 4 a a 0 0 0 0 0 0 4 4 a & a 0 4 0 0 a 4 a 6 0 a 4 a sell adds 2 SITE CONDITIONS 0400 added a a's 0*0 0 0 0 eased Goosed a @so 6000000060 Cn 2 m 0 a a a a a 0 0 4 a 4 0 4 a 0 0 6 a 0 a 0 0 0 a 4 a a a 0 a a 0 4�6 0 a a a a a a a a a 0 a 0 0 a a Surface C M 0 3 Steep Slope EvalualLon deal 0 3 0 C Subsurface 4 m 6 0 0 a 0 a 0 a a 0 a 0 4 a a 0 a a a a a a a 9 0 a 0 8 a 4 6 Groundwater. m Z, 4 10 deal a 4 4 0 a a 0 a 0 0 0 0 a a 0 0 0 a a 4 a 6 0 a 0 0 a 9 a a 0 a a a 4 a 0 4 0 0 0 a 0 Laboratory Tesmg dead C z > momil 4 N AND RECOMMENDATIONSO a a 6 0 0 a a a 4 6 0 6 0 4 a 4 0 a 0 0 0 a 0 a 4 0 0 a 4 a 0 4 4 4 a a 6 a 0 0 a a 0 0 a a 4 leads DISCUSSIO 4 M General80440 oeseasome added *does 4 4 4 a a a 4 0 4 as a ad a a a 0 a a 0 a a a a 00000 0 04 a a losses a *seems 4 0 am a 6 den Site Preparation and General Earthwork. a a 0 a a 4 a 0 a a 4 a 4 a 0 0 0 0 a 6 1 a 6 a 4 a 0 0 1 a a a 0 a 4 0 0 a 4 6 4 0 0 a 0 a a "Mai 7 Steep Slope Buffer m M a 8 Foundations. dead CD 0 9 red Permanent Retaining and Foundation Walls .......possessed 0.6404 0000000*0 on 8464444 4 a a a 6 0 a a 0 9 0 0 0 4 a a a 0 m I I samovosoes 10 Cn Seismic Design Considerations...... �4468 ad goddesses 0 Models 0 losses 64400 0 0044409 6*044 sea 00000000 cn, Slab —on —Grade Floors. M 0 z resed dead! Site Drainacie. Excavations and Slopes adooloodasome adds eggs a 0 a 4 a 4 a 0 a a 6 6 4 0 a a 9 a a a a 0 0 a a a 4 4 0 a a a 0 a 4 0 4 a 0 a a a a 9 1 0 4 a 0 0 a 0 1 2 Wilily Trench Backfill 664464644 eased 4 lasso a 4 a A a 6 a 1 2 13 z Rockeriesa 0 a 4 a 0 4 0 a a a 4 0 0 a a 0 a 0 4 4 8 0 a 0 a a a a 6 0 a 0 4 4 4 a 0 a 0 a 0 a 0 a 0 a 4 6 4 14 Pavement Areas 00000 od4*0004 ago "oes 40 a a 0 0 a 4 0 0 0 a 6 4 4 0 6 0 a a 9 a a a 4 0 a a a a dead Cn z LIMITATIONS*0604000000 fleas asoodeael 4 a 9 a 6 a a a 6 a 0 a 9 a 9 a 0 a 9 4 0 0 a 0 4 d 0 4 a 0 a a 6 4 a 0 4 0 0 0 14 0 15 AddftionalServicess 0 a 0 a a 4 a 0 0 a 4 0 0 a a 0 a 4 4 0 a 0 4 0 4 a 4 0 a 0 0 0 a a a a 0 a 0 0 a 0 a a a a a 0 a a a a 9 0 0 a a 0 a 0 0 a 0 a 0 4 0 a 0 A a 0 4 9 4 a a 4 0 4 0 0 0 a 0 a a 0 m Earth Consultantse Inc, TABLE OF CONTENTS E-10075 ILLUSTRATIONS Plate 1 Vicinity Map Z 0 Plate 2 Test Pit Location Plan Plate 3 Typical Footing Subdrain Detail K Plate 4 Typical Utility Trench Fill 9 m APP ENDICES C M, Appendix A Field Exploration 0 0 0 C Plate Al Legend IT! Plates A2 through Al 2 Test Pit Logs ITIZI Appendix B Laboratory Test Results -4 X plate 131 Grain Size Analyses CD 0 -n M m 0 m C CA K W �mo I Z ;U Z:I Z 0 j:. 0 m Earth consultants, Inc. GEOTECHNICAL ENGINEERING STUDY PEPPERWOOD RES! DENTIAL DEVELOPMENT 8526 MAIN STREET EDMONDS, WASHINGTON E-11 0075 INTRODUCEON rjpnp-ra This report presents geotechnical recommendations for the proposed Pepperwood Residential Development to be located at 8526 Main Street, Edmonds, Washington. The general location of the site is shown on the Vicinity Map, Plate 1. The approximate locations of the test pits and the approximate limits of the property are illustrated on the Test Pit Location Plan, Plate 2. Our scope of services included a subsurface exploration to characterize soil conditions at the site, and preparation of this report with geotechnical recommendations for the proposed site development. P-mopet Dp-scdpfim We understand development of the site will consist of a 22-lot subdivision and construction of a storm water detention vault. New access roadways will be constructed throughout the property, and will connect to Main Street on the upper east half of the property and Pioneer Way along the lower west portion of the property. At the time this geotechnical engineering study was prepared, a final grading plan had not been completed. However, we anticipate that cuts and fills will be necessary to establish the building lot and roadway grades. Construction of a storm water detention vault is proposed for the lower west portion of the site, along the new access roadway that will connect to Pioneer Way. Cuts for the detention vault will probably be in the range of twelve (12) to sixteen (16) feet. Cuts along the toe of the existing steep slopes will likely be necessary to establish roadway grades for the new access roadway that will connect to Pioneer Way. The use of rockeries may be necessary to transition grades in landscaping areas and to provide permanent erosion control along cuts. Reinforced rockeries may also be utilized along the back of the building lots located at the top of the slope areas. Preliminary design information indicates that the alignment of the reinforced fill rockery may be located on the existing slopes. Earth Consultants, Inc. Z 0 rn --i -n 3: M 0 0 0 0 C -49 X M M Z C') o -n n M M 0 0 0 M C: cl) K Cn M 0 Z 7-1 3: Z --i 3: 0) Z 0 M GEOTECHNICAL ENGINEEFUNG STUDY Phoenix Development, Inc. E-10075 May 14, 2002 Page 2 An existing rockery along Main Street will be maintained and incorporated into the final development. The existing rockery is up to approximately ten (10) feet to twelve (12) feet in height and was likely constructed during widening and improvements to Main Street. An assessment of the existing rockery is provided in the Rockeries section of this report. The use of relatively lightly loaded wood frame construction is anticipated for the proposed single family residences. We estimate wall loads will be in the range of one to two kips per lineal foot, and column loads in the range of ten (10) to twenty (20) kips. If the above design criteria are incorrect or change, ECI should be notified and allowed t o review the recommendations contained in this report. In any case, ECI should be retained to perform a general review of the final design. SITE CONDITIONS Surface The approximate property limits and site topography are illustrated on the Test Pit Location Plan (Plate 2). The majority of the site is undeveloped and heavily vegetated, with the exception of several rental homes located along Main Street. The topography is partitioned into two halves, with a slope area approximately bisecting the site in a north - south direction. The slopes descend to the west at grades of approximately 30 percent to .40 percent. The overall height of the slope ranges from approximately forty (40) to fifty (50) feet. Based on the site survey prepared by Group Four Inc., the steep slope areas within the planned development are limited to the north end of the property adjacent to Building Lot 9. The upper east half of the property is relatively flat, with gently sloping areas that descend to the east. An existing rockery and steep driveway area are located at the northeast corner of the site. As previously discussed, the existing rockery will be incorporated into the new development, and the driveway areas will likely be filled to create a level building lot area. The maximum height of the existing rockery is approximately ten (10) to twelve (12) feet. The lower west portion of the development area is located at the toe of the existing slope that approximately bisects the property in a north -south direction. The immediate toe area of the site is relatively flat, and is located along an existing utility easement corridor that connects to Main Street on the north and Pioneer Way on the south. On the extreme west side of the property, west of the utility easement, there is an area of ascending steep slopes. Development is not planned in this area. Earth Consultants, Inc. z 0 1 0 M M C M 0 __10 0 C M M Z 0) 0 -n n M M 0 6) 0 r- 0 M C cl) K 0) Q 0 Z X z --I z 0 --I M GEOTECHNICAL ENGINEEPJNG STUDY Phoenix Development, Inc. E-10075 May 14, 2002 Page 3 Steep Slope Evaluation At the time our field exploration was performed (March 2002), the steep slope areas of the site were observed for signs of instability or severe erosion. Based on our observations, the steep slope areas appear stable. There were no indications of shallow or deep seated slide activity. The slope areas are generally heavily vegetated with mature Douglas Fir, and there were no indications of severe erosion due to surface water runoff. ble. Based on our observations, it appears the slopes are sta Subsurface Eleven test pits were excavated throughout the site. The test pits were excavated to depths of approximately five to eight feet, where very dense glacial till soil conditions were encountered. Please refer to the test pit logs, Plates A2 through Al 2, for a description of the conditions encountered at the test pit locations. The soils encountered at the test pit locations consisted of medium dense to very dense silty sand with gravel (Unified Soil Classification SM). Sand deposits were occasionally observed throughout the glacial till deposit. The depth of the topsoil layer varied, and typically ranged between two inches to twelve (12) inches. The geologic map of the area identifies the silty sand with gravel deposit as glacial till. The upper three to four feet of the soil deposit generally consisted of weathered glacial till. The weathered till was in a medium dense condition, and was characterized by brown to dark brown coloring. Dense to very dense unweathered glacial till was encountered below the weathered glacial till layer. The unweathered glacial till was generally characterized by a gray to dark gray coloring. Fill was observed at test pit locations TP-4 and TP-5. The fill consisted of loose silty sand soils, and extended to depths of four to five feet. Yard waste piles were also observed along the top of the steep slope area in the vicinity of Test Pits TP-4 and TP-5. At the time the test pit exploration was performed (March 2002), the upper deposit of weathered glacial till was generally in a wet condition. Laboratory testing indicates moisture contents of approximately 13 to 16 percent, or greater for the weathered glacial till. The lower deposit of unweathered glacial till was in a moist to wet condition, and had moisture contents generally in the range of approximately 8 percent to 10 percent. Earth Consultants. Inc. Z 0 'I 0 M --i -n 0 M M 0 0 —40 0 C M M Z 0 -n n M M 0 0 0 M Cl) Cn M 0 Z Z CO Z 0 I 0 M GEOTECHNICAL ENGINEEFUNG STUDY Phoenix Development, Inc. E-10075 May 14, 2002 Page 4 Groundwater Groundwater seepage was not observed at the time of our exploration (March 2002). The presence of light to moderate groundvvmter seepage, however, should be expected in deep excavations. Based on the conditions observed at the time of our field exploration, we do not anticipate groundvwter seepage will adversely impact the earthwork. Groundwater seepage levels and the rate of seepage are not static; fluctuations in the level and rates can be expected depending on the season, amount of rainfall, surface water runoff, and other factors. Generally, the level and rate of seepage is higher in the wetter winter months (typically October through May). Laboratory Testing The results of laboratory tests performed on specific samples are provided in Appendix B, or at the appropriate sample depth on the test pit logs. it is important to note that these test results may not accurately represent the overall in -situ soil conditions. Our geotechnical recommendations are based on our interpretation of these test results. ECI cannot be responsible for the interpretation of these data by others. DISCUSSION AND RECOMMEWATIONS General Based on the subsurface conditions observed at the test pit locations, development of the site is feasible from a geotechnical standpoint. The proposed single family residences can be supported on conventional spread and continuous footings bearing on the medium dense to dense glacial till soils observed at the test pit locations. The building foundations can also be supported on structural fill soils that are used to modify the existing site grades. The medium dense to dense glacial till soil suitable for support of foundations was generally observed at a depth of approximately two feet below the native ground surface elevation. Earth Consultants, Inc. z 0 0 M GEOTECHNICAL ENGINEERING STUDY Phoenix Development, Inc. May 14, 2002 E-10075 Page 5 Due to the dense condition of the glacial till soils and the stable condition of the steep slope area, a minimum steep slope buffer of ten (10) feet from the top and toe of the steep slope areas can be considered for the proposed single-family residences. As previously discussed, the site survey prepared by Group Four, Inc. indicates that the steep slope areas within the planned development area are limited to the north end of the site, adjacent to Building Lot 9. In our opinion, reinforced fill rockeries can be successfully constructed on the existing steep slope, provided an engineered rockery design is completed. Steep slope buffer and foundation recommendations are provided in the Steep Slope Buffer and Foundations sections of this report. Preliminary rockery design recommendations are provided in the Rockeries section of this report. In our opinion, the majority of the existing rockery located along Main Street can be utilized and incorporated into the new development. Several of the existing rocks along the upper row of the rockery, however, will need to be replaced due to severe weathering. ECI will work with the contractor to identify the rocks that need to be replaced. With regard to the existing driveway areas that will likely be filled and brought up to the level of the existing rockery, the use of a geogrid reinforced fill will be necessary where the fill heights exceed approximately four feet. An engineered rockery design will also be needed for the proposed fill areas along the alignment of the existing Main Street rockery. In our opinion,. construction of the proposed storm water detention vault is feasible from a geotechnical standpoint. Medium dense to dense glacial till soil will likely be encountered in the excavation for the storm water detention vault. Based on the conditions observed at the test pit locations, groundwater seepage may be encountered in the excavation for the storm water detention vault. However, in our opinion, groundveter seepage will likely not adversely impact the stability of the detention vault excavation. Recommendations for temporary excavations are provided in the Excavations and Slopes section of this report. Cuts will be performed for the proposed access roadway that will connect to Pioneer Way. These cuts may encroach into the toe of the existing steep slope areas on the west side of the property. Due to the dense glacial till soil conditions observed at the site, it is our opinion the roadway cuts will not compromise the stability of the slopes. We anticipate the roadway cuts will not exceed six feet along the toe of the steep slopes. In our opinion, construction of a rockery along the planned roadway cuts can be considered. Earth Consultants, Inc. Z M M C MID 0 0 0 C X M M Z C _Z Cl) 0 -n n M M 0 0 0 M C cl) 9 Cl) Q 0 Z Z Z 0 M GEOTECHNICAL ENGINEEFJNG STUDY Phoenix Development, Inc. May 14, 2002 E-10075 Page 6 This geotechnical engineering study has been prepared for the exclusive use of Phoenix Development, Inc. and their representatives. This study was prepared for specific application to this project only and in a manner consistent with that level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area. No other warranty, expressed or implied, is made. We recommend that this geotechnical engineering study, in its entirety, be included in the project contract documents for the information of the contractor. Site Preparation and General Earthwork The proposed development areas of the site should be stripped and cleared of existing surface vegetation, topsoil, existing structures, and other deleterious materials. Existing utility pipes that will be abandoned should be plugged or removed. Based on the conditions observed at the test pit locations, the thickness of the topsoil layer ranges between approximately two (2) inches to twelve (12) inches. 'The thickness of the topsoil layer will vary throughoutthe site. The ground surface where structural fill, or foundations are to be placed should be observed by a representative of ECI. An ECI representative should also observe the excavation for the proposed storm water detention vault and roadway cuts. Existing fill soil and organic debris that is encountered in the building and vault foundation excavations should be overexcavated. Due to the relatively high fines content of the native soils, moisture sensitivity of the soils will be moderate to high. Building and pavement subgrade areas that are exposed to extended periods of precipitation will likely become unstable. If the subgrade soil in the proposed foundation and pavement areas becomes saturated and unstable, overexcavation of the unstable soil and replacement with structural fill may be necessary. In our opinion, the majority of the native soils can be considered for use as structural fill, provided the soil is placed during dry weather conditions, and provided the moisture content of the soil is at or near the optimum moisture content at the time of placement. At the time of the subsurface exploration (March, 2002) the upper deposit of weathered glacial till was generally in a wet condition. Laboratory testing indicates moisture contents of 13 percent or greater for the weathered glacial till. The lower deposit of unweathered glacial till was generally in a moist to wet condition, and had moisture contents of approximately 10 percent. ECI will work with the contractor to assess the suitability of the on -site soils for use as structural fill. Earth Consultants, Inc. z 0 4 0 R! =i --fi M C MO 0 __10 0 C M M z 0 M M 0 0 0 M C cl) 9 Cn M 0 Z X z z 0 1 0 M GEOTECHNICAL ENGINEEPJNG STUDY Phoenix Development, Inc. E-10075 May 14, 2002 Page 7 Imported soil intended for use as structural fill should consist of a fairly well graded granular soil with a moisture content that is at or near the optimum moisture content, and having a maximum aggregate size of four inches. During wet weather conditions, imported fill should consist of a fairly well graded granular material having a maximum Z 0 ize of four inches and no more than 5 percent fines passing the No. 200 sieve based on, s the minus 3/4-inch fraction. M Structural fill is defined as compacted fill placed under foundations, roadways, slabs, --j pavements, or other load -bearing areas. Structural fill under slabs and footings should be X M C placed in horizontal lifts not exceeding twelve (12) inches in loose thickness and M C) 0 compacted to a minimum of 90 percent of its laboratory max imum dry density. The 0 0 C maximum dry density should be determined in accordance with ASTIVI Test Designation -4 r. I the optimum D-1 557-91 (Modified Proctor). The fill materials should be paced at or near X M M Z moisture content. Fill under pavements and walks should also be placed in horizontal lifts C _Z and compacted to 90 percent of the maximum dry density except for the top twelve (12) > inches, which should be compacted to 95 percent of the maxi mum dry density. If a 55 structural fill berm is necessary to construct the storm water detention pond, the fill 0 _n _n should be compacted to at least 95 percent of the maximum dry density. M M Steep Slgpg Buffer C) 0 0 M C Cn In our opinion, due to the dense condition of the glacial till soils observed at the site, and 9 (D i I M the stable condition of the existing slope areas, a minimum ten (10) foot bu ffer from the 0 Z top and toe of the steep slope areas can be considered for the proposed single-family residences. The City of Edmonds Development Standards for Geologically Hazardous Areas are found under Title 20 (Chapter 20.15B). The Development Standards allow the > required buffer distance to be reduced from fifty (50) feet to ten (10) feet, provided a Z geotechnical report can demonstrate that no adverse impacts to the slope or surrounding X developments will result. In our opinion, reducing the buffer distance to ten (10) feet will Z not adversely impact the stability of the steep slope areas. The observed stability of the 0 i existing slope and the presence of dense glacial till soils is the primary basis for this 0 M recommendation. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Phoenix Development, Inc. E-1 0075 May 14, 2002 Page 8 In our opinion, grading and the placement of fill on the slope will not adversely impact the stability of the slope. We understand fill placement along the backside of the upper building lots adjacent to the slope areas may be necessary to establish relatively level backyard areas. Reinforced fill rockeries can be used to transition the grade between the Z' fill and the slope. In our opinion, due to the dense glacial till soil conditions, fill and 0 rockery placement on the slope will not adversely impact the stability of the slope. As 0 previously discussed, an engineered reinforced rockery design should be completed for M the proposed fill and rockery areas. =i r Foundations rn C 0 M 0 -10 In our opinion, the proposed single family residences can be supported on conventional 0 C: spread and continuous footings bearing on the medium dense t o dense glacial till soil -4 C X M observed at the test pit locations. Where necessary, the proposed building foundations M z can also be supported on structural fill that is used to modify the existing site grades. C: 2 Foundations should not be supported on the existing fill soils. The medium dense to E: dense glacial till soils suitable for support of foundations was generally observed at a Cn -" depth of approximately two feet below the native ground surface elevation. 0 For foundations bearing on the medium dense to dense glacial till soil or structural fill, an M rn 0 allowable soil bearing capacity of two thousand five hundred (2,500) pounds per square 0 foot (psf) can be used. This allowable soil bearing capacity has a facto r-O f-safety in 0 M C CD 9 Cn excess of 3.0 against shear failure, provided the foundations are placed on competent rn 0 Z native soils'or structural fill. A one-third increase in the above allowable soil bearing capacity can be assumed for short-term wind and seismic loading conditions. Continuous and individual spread footings should have minimum widths of eighteen (18) and twenty- four (24) inches, respectively. z r If loose or unstable soil conditions are encountered at the footing subgrade elevation, the CO soil should be overexcavated, and replaced with structural fill. The width of the z 0 overexcavation should extend a minimum of six inches beyond each edge of the --I 0 foundation. M Exterior foundations elements should be placed at a minimum depth of eighteen (18) inches below final exterior grade. Interior spread foundations can be placed at a minimum depth of twelve 0 2) inches below the top of slab, except in unheated areas, where interior foundation elements should be founded at a minimum depth of eighteen (18) inches. Earth Consultants, Inc. GEOTECHNICAL ENGINEEMINIG STUDY Phoenix Development, Inc. May 14, 2002 E-10075 Page 9 Provided the foundations are placed in accordance with the recommendations contained in this report, we estimate total settlement of approximately one inch and differential settlement of approximately one half inch. Most of the anticipated settlements should occur during construction as dead loads are applied. Lateral loads can be resisted by friction between the base of the foundation and the supporting soil, and by passive soil pressure acting on the face of the buried portion of the foundation. Resistance to lateral loads from passive earth pressures can be calculated using an equivalent fluid with a unit weight of three hundred fifty (350) pounds per cubic foot (pcf). To achieve adequate passive resistance, the foundations must be backfilled with structural fill. As an alternative, the foundations can be poured neat against the undisturbed native soil. For frictional capacity, a coefficient of 0.40 can be used for foundations bearing on competent native soils or structural fill. These lateral resistance values are allowable values; a facto r-of-safety of 1.5 has been included. Footing excavations should be observed by a representative of ECI prior to placing the formwork and repar. ECI should also observe areas where overexcavation is required to remove loose or unstable soils. Permanent Retaining and Found_afionWalls Retaining and foundation walls should be designed to resist lateral earth pressures from the retained soils, and any surcharge loading. Walls that are unrestrained and free to move at the top can be designed using an equivalent fluid with a unit weight of thirty-five (35) pcf. The earth pressure imparted on restrained walls should be calculated using an equivalent fluid with a unit weight of fifty (50) pcf. The above equivalent fluid values assume surcharges due to traffic, adjacent foundations, construction loads, or any other loadings will not apply. If surcharges are to apply, they should be added to the above design lateral pressures. For traffic surcharge loading, a uniform pressure of seventy (70) psf should be applied in a rectangular distribution along the height of the retaining wall. If sloping backfill conditions are present behind the walls, ECI should review the slope configurations and provide modified equivalent fluid values, as necessary. Earth Consultants, Inc. z 0 4 0 :; 9 Om C RIO 0 0 0 C --I K X M M Z r') --I C C1) 0 _n n M M 0 F) 0 r- 0 M C cl) 9 V) Q 0 Z z a: 65 z 0 1 .0 M GEOTECHNICAL ENGINEEMNIG STUDY Phoenix Development, Inc. May 14, 2002 E-10075 Page 10 Retaining and foundation walls should be provided with a four inch diameter perforated drainpipe and backfilled with a free -draining granular soil with less than 5 percent fines (percent passing the No. 200 sieve based on the minus % inch fraction). The zone of free -draining granular soil should extend along the entire height of the wall, and a distance of at least eighteen (18) inches behind the wall. A surface seal consisting of a less permeable silty sand soil can be placed along the upper one foot of the wall backfill, if desired. The remainder of the backfill behind the zone of free draining soil should consist of a suitable granular structural fill. Seismic Design Consideration The Puget Sound region is classified as Zone 3 by the Uniform Building Code (UBC). The largest earthquakes in the Puget Sound region have been subcrustal (intraplate) events, ranging in depth from fifty (50) to seventy (70) kilometers. Such deep events have exhibited no surface faulting. Weaver and Shedlock (1989) researched the probable or known source areas for the crustal, intraplate, and subduction zone earthquakes in the Washington and Oregon area. Crustal and intraplate earthquakes are the only events in Washington and Oregon in which there is a historical record. Shallow crustal earthquakes occur within the North American Plate, and typically do not exceed focal depths of approximately 20 kilometers. Intraplate earthquakes occur in the subducting Juan de Fuca plate, and typically occur below depths of 40 kilometers. The recent February 28, 2001 earthquake that was focused just north of Olympia, Washington was an intraplate earthquake, and had a magnitude Of ML =6.8. The subduction zone earthquake, in which there is no historical record in the Washington and Oregon area, would have its source along the interface between the North American Plate and the subducting Juan de Fuca Plate. Magnitude 8+ earthquakes are thought to be possible along this interface, and would occur at depths of approximately 50 to 60 kilometers (Weaver and Shedlock, 1989). The UBC Earthquake regulations have established a series of soil profile types that are used as a basis for seismic design of structures. Based on the encountered soil conditions, it is our opinion that soil type Sc from Table 16-J of the 1997 UBC should be used for design. Liquefaction is a phenomenon in which soils lose all shear strength for short periods of time during an earthquake. The effects of liquefaction may be large total and/or differential settlement for structures with foundations founded in the liquefying soils. Groundshaking of sufficient duration results in the loss of grain -to -grain contact and rapid increase in pore water pressure, causing the soil to behave as a fluid for short periods of time. Earth Consultants, Inc. Z 0 i 0 M :; --fi M C M 0 0 C: M M Z —Z Cn 0 _rl n M M 0 5) 0 r- 0 M C cl) 9 0 M 0 Z X Z Z 0 i 0 M GEOTECHNICAL ENGINEEFUNG STUDY Phoenix Development, Inc. E-1 0075 May 14, 2002 Page 11 To have potential for liquefaction, a soil must be cohesionless with a grain size distribution of a specified range (generally sands and silt); it must be loose to medium - dense; it must be below the groundv\eter table; and it must be subject to sufficient magnitude and duration of groundshaking. Z 0 Based on the soil and groundv\eter conditions observed at the site, it is our opinion that 0 M the site has a low susceptibility to liquefaction. The dense condition of the native soils is the primary basis for this conclusion. CD M Slab -on -Grade Floors C 0 M 0 -40 0 C: Slab -on -grade floors can be supp oried on competent native soils or structural fill. Loose -4 r. or unstable subgrade soils should be stabilized prior to construction of the s lab. The use X M M Z of a geotextile and crushed rock can be considered for stabilizing the subgrade soils, if ID -1 C necessary. A four4nch capillary break consisting of a free draining poorly graded sand or > gravel with less than 5 percent fines (perce nt passing the No. 200 sieve, based on the X Vi minus 3/4-inch fraction) should be placed below the slab. In areas where slab moisture is 0 -n undesirable, a vapor barrier such as a 6-mil plastic membrane can be placed beneath the n free draining sand or gravel. The subgrade soils in slab -on -grade areas of the site should X M M be observed by a representative of ECI prior t o placing the capillary break material. 0 U5 0 r- 0 M C Site Drainne 9 Cn M 0 During construction, surface water runoff must not be allowed to stand in construction Z areas. Interceptor trenches should be established, as necessary, along the perimeter of the building site before it enters the construction area. During construction, loose > surfaces should be compacted to reduce the potential for moisture infiltration into the Z soils. Finish grades around the buildings must be sloped such that surface water is directed away from the buildings. Z 0 Perimeter footing drains should be installed around the perimeter foundations to intercept M groundv\eter seepage. A typical perimeter footing drain detail is illustrated on Plate 3. Under no circumstances should roof downspout drain lines be connected to the footing or foundation wall drain systems. All roof downspouts must be separately tightlined to the site storm water system. Earth Consultants, Inc. GEOTECHNICAL ENGINEEPJNG STUDY E-1 0075 Phoenix Development, Inc. May 14, 2002 Page 12 Excavations and Slope The following information is provided solely as a service to our client. Under no circumstances should this information be interpreted to mean that ECI is assuming. responsibility for construction site safety or the contractor's activities; such responsibility is not being implied and should not be inferred. In no case should excavation slopes be greater than the limits specified in local, state, and Federal safety regulations. - Based on the information obtained from our field exploration, the upper deposit of weathered glacial till that extends to a depth of approximately four feet below existing site grades would be classified as Type C soils by OSHA. The existing fill observed at the site would also be classified as Type C soil. Temporary cuts in Type C soils should be sloped at an inclination no steeper than 1.5H:1 V (Horizontal:Vertical), respectively. The unweathered glacial till observed below a depth of approximately four feet would be classified as Type A and Type B soils by OSHA. Temporary slopes constructed in Type A and Type B soils should be inclined no steeper than 0.75H: 1 V and 1 H: 1 V, respectively. ECI should observe the excavations to assess soil and groundv�ater conditions, and to verify the OSHA soil type. Permanent cut and fill slopes should be inclined no steeper than 2H:1V. Cut slopes should be observed by ECI during excavation to verify that conditions are as anticipated. Supplementary recommendations can then be developed, if needed, to improve stability, including flattening of slopes or installation of surface or subsurface drains. In any case, water should not be allowed to flow uncontrolled over the top of slopes. Permanently exposed slopes should be seeded with an appropriate species of vegetation to reduce erosion and improve stability of the surficial layer of soil. Uitility-Trench Backfill Based on the soil conditions encountered at the time of our exploration, the native soils should provide adequate support for utilities. If remedial measures are necessary to provide adequate support for utilities, the unsuitable soils can be overexcavated and replaced with a rock ballast and pipe bedding material such as pea gravel. The presence of groundv\ater seepage should be expected in the deeper utility trench excavations and the proposed detention vault excavation. Earth Consultants. Inc. z 0 1 0 M --i -n 0) M C M 0 -10 0 C M M Z 10--1 .1 C —Z 0 -n n --i X MM 0 0 0 M C cn 9 C/) Q 0 Z X z W z 0 -1 0 M GEOTECHNICAL ENGINEENNG STUDY Phoenix Development, Inc. May 14, 2002 E-1 0075 Page 13 In our opinion, the native soils can be considered for use as backfill for the utility trenches. At the time of the subsurface exploration (February, 2002) the upper deposit of weathered glacial till was generally in a wet condition, with moisture contents in excess of 16 percent. The lower deposit of unweathered glacial till was generally in a moist to wet condition, and had moisture contents of approximately 10 percent. ECI will work with the contractor to assess the suitability of the on -site soils for use as utility trench backfill. As previously mentioned, the soil should be placed during dry weather conditions, and the moisture content of the soil should be at or near its optimum moisture content at the time of placement. Utility trench backfill is a primary concern in reducing the potential for settlement in pavement areas. It is important that the utilities be adequately supported in the bedding material. The material should be hand tamped to ensure support is provided around the haunches of these structures. Fill should be carefully placed and tamped to about twelve (12) inches above the crown of the pipe before heavy compaction equipment is brought into use. The remainder of the backfill should be placed in lifts having a loose thickness of less than twelve (12) inches. A typical trench backfill section and compaction requirements for load supporting and non -load supporting areas is presented on Plate 4. Rockeries We understand the existing rockery located along Main Street at the northeast portion of the site will be incorporated into the new development. The rockery is approximately 180 feet in length, and ranges between four (4) feet to twelve (12) feet in height. We estimate the rockery has been in place for approximately twenty-five years. Two existing driveways that ramp up through the alignment of the rockery face will be filled as part of the proposed development to establish a level building lot area. Construction of new reinforced fill rockeries is currently being considered for purposes of retaining the new fill. As discussed previously, an engineered rockery design will need to be completed for the reinforced fill rockeries proposed for the site. Based on our observations, the majority of the existing rockery has experienced minor to moderate weathering. The minor to moderate weathering was primarily observed along the lower rows of the rockery. In our opinion, these rocks are still structurally sound and will not have to be replaced. Several of the upper rocks have experienced severe weathering, and should be replaced. These rocks are located primarily along the higher portions of the rockery. ECI will work with the contractor in identifying rocks that should be replaced. Earth Consultants, Inc. z 0 4 0 R! =i --fi M M 0 0 0 0 C ­4 r. = M M Z 1[) —1 C 0) 0 71 n M M 0 0 0 M C (n 90) M C) Z 3: z --i X C1) z 0 1 0 M GEOTECHNICAL ENGINEERNG STUDY Phoenix Development, Inc. May 14, 2002 Pavement Areas E-1 0075 Page 14 The adequacy of site pavements is related in part to the condition of the underlying subgrade. To provide a properly prepared subgrade for pavements, the subgrade should be in a firm and unyielding condition when subjected to proofrolling with a loaded dump truck. Strvctural fill in pavement areas should be prepared as described in the Site Preparation and General Earthwork section of this report. This means the pavement subgrade should be compacted to at least 95 percent of the maximum dry density. It is possible that some localized areas of soft, wet or unstable subgrade may exist after the pavement subgrade is prepared. Overexcavation and a greater thickness of structural fill or crushed rock may be needed to stabilize these localized areas. A biaxial geogrid such as Tensar BX-11 200 can be considered for use below the crushed rock where bridging of unstable subgrade is necessary. Assuming a properly prepared subgrade, the following pavement section for lightly -loaded areas can be used: Two inches of asphalt concrete (AQ over four inches of crushed rock base (CRB) material, or 0 Two inches of AC over three inches of asphalt treated base (ATB) material. Heavier truck -traffic areas will require thicker pavement sections depending upon site usage, pavement life, and site traffic. If necessary, ECI can provide pavement design recommendations for truck traffic areas. Asphalt concrete (AC), asphalt treated base (ATB), and crushed rock base (CRB) materials should conform to WSDOT specifications. All rock bases should be compacted to at least 95 percent of the maximum dry density. LIMIT-ATIONS Our recommendations and conclusions are based on the site materials observed, selective laboratory testing and engineering analyses, the design information provided to us, and our experience and engineering judgement. The conclusions and recommendations are professional opinions derived in a manner consistent with that level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area. No warranty is expressed or implied. Earth Consultants, Inc. Z 0 1 0 M —i -n f M C: M 0 __10 0 C: X M M Z C o -n n M M 0 5) 0 r- 0 M 0) C/) M 0 Z Z Z 0 M GEOTECHNICAL ENGINEEPJNG STUDY Phoenix Development, Inc. E-10075 May 14, 2002 Page 15 The recommendations submitted in this report are based upon the data obtained from the test pits. Soil and groundv�eter conditions between exploration sites ma y vary from those encountered. The nature and extent of variations between our exploratory I ld locations may not become evident until construction. If variations do appear, EC shou be requested to reevaluate the recommendat ions of this report and allowed to modify or Z. 0 verify our recommendations in writing prior to proceeding with the construction. Additional Services We recommend that ECI be retained to perform a general review of the final design and C M pecification hat the earthwork and foundation recommendations have been s s to verify t M 0 0 p roperly interpreted and implemented in the design and in the construction specifications. 80 C M We also recommend that ECI be retained to provide geotechnical services during M z construction. This is to observe compliance with the design concepts, specifications or C z recommendations and to allow design changes in the event subsurface conditions differ > from those anticipated prior to the start of c onstruction. We do not accept responsibility Cn for the performance of the foundati ' on or earthwork unless we ar e retained to review the 0 -n j construction drawings and spec ifications, and to provide construction observation and testing. M M C/) 0 0 M C C/) K cly MO Z M Earth Consultants, Inc. e CHERRI ST "'W lolls ;f, N% 9601 -,13 57---s W& 1 RFU %4 -A 0, ri mi lat? St J z 01141310a 1, 0 Fol't% FE 194 CIL V, 1-96T 4. -:ST. ..Am �r SW F �ftoo­­,�:r."­', PU ET PU�ET MELODY LN wyr 7! lr� j, Wy 157 HINOL OR SMOMSE ST :A jip S7. iwERWu I-C P S ST,7 . . . . ...... . _. ..- , - - " 11 � I �14._ 15T L MI "Ni W, -A SIERPA-,- 202NO S-R.ACKEnS >1 U _rx : . PT A, t --LA010 L I 13M `1` My Y pt-Y, :200TH' PARK HER U YTSTA'� 51 OLEN let' ST SEACH I- : , SE 24 Cn X R CL 7'77 PRAGUE MT P iEE 111U, 1AW1 S4 MI --%%qmw 00 ELL ST W ton L MIN TIN ST 00 W MAPLC ;J_ V). 1z LNUI C, CEDAR ST-': LA_R FL - POW IL S CE A _11 WY PL 14W SWCE ST z 4M SX1 W,: 1, . 11 .. . — SW < E; t-A 'Lit -W 20 215TH se 2 1 Sql ST PL - %_G� 215 f Laid OR, ST;: Win PLC F -pill 710H OY 0, ST. Ft ST. !6 > _9W_ , . 0 ..< e LK ;jI I 9 S 5_ 218TH ST 216 MU PL F R LLJ ne . — i I . s I ..: 30. S1 SW 221 TH 10 ATE UP S'F Sc ;rzo�rdn TnD UH W." Ci _j 22 Cis yy CC) 22-711D bi _j L Cl jv C., VH 9v KNST Reference: Puget Sound Area Snohomish County / Map 454 By Thomas Brothers Maps Dated 2002 NOTE: This plate may contain areas of color. ECI cannot be responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. 1.-arth Consultants, Inc. & iinvirt-xiinvoital Vicinity Map Pepperwood Edmonds, Washington Drwn. GLS Date April 2002 Proi. No. 10075 checked RAC Date 4112/02 Plate 1 z 0 1 0 M =n- Cn 0 M C M 0 -10 0 CZ M M Z ID --i C: _Z x U) 0 _n n M M 0 _U) 0 r- 0 M C Cn 9 C0 M 0 Z z Cn z 0 M Subject Site Existing Building 6 Lot Number NOTE: This plate may contain areas of color. ECI cannot be responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. Earth Consultants, Inc. Geotediniral Engineerr, Geologists & E:nvircntnental scienfists Test Pit Location Plan Pepperwood Edmonds, Washington I GLS Date April 2002 Proi. No. 10075 I I IDrwn. Checked RAC I I Date 4/12/02 Plate 2 z 0 1 0 M W - Slope To Drain A zID 0 6 inch min. 0 M 18 inch min. 0 M C M 0 0 0 C 4 inch min. X M M z Diameter 0 0 Perforated Pipe C G. 0 >Z Wrapped in Drainage 01, r Fabric 0 -n -n 2 inch min. 2 inch min. 4 inch max. M M 12 inch 0 —co min. 0 r- 0 M C Cn Cn Q0 SCHEMATIC ONLY - NOT TO SCALE Z NOT A CONSTRUCTION DRAWING LEGEND > z Surface seal; native soil or other low permeability material. CD Fine aggregate for Portland Cement Concrete; Section 9-03.1(2) of the z 0 WSDOT Specifications. M Drain pipe-, perforated or slotted rigid PVC pipe laid with perforations or slots facing down; tight jointed; with a positive gradient. Do not use flexible corrugated plastic pipe. Do not tie building downspout drains into footing lines. Wrap with Miral'i 140 Filter Fabric or equivalent. TYPICAL FOOTING SUBDRAIN DETAIL Earth Consultants Inc. Pepperwood Cx0109L'As En%imM%mlial Sck-ni6ts I Edmonds, Washington Checked RAC Date 4/12/02 _lPlate 3 Proj. No. 10075 GLS Date Apr. 2002_ Non -Load Supporting Floor Slab or Areas Roadway Areas Backfill . � Bedding Varies 1 Foot Minimum Varies Varies LEGEND: &J. Asphalt or Concrete Pavement or Concrete Floor Slab 9_5 —..-V 771 I o o o-1 Base Material or Base Rock Backfill; Compacted On -Site Soil or Imported Select Fill Material as Described in the Site Preparation of the General Earthwork Section of the Attached Report Text. Minimum Percentage of Maximum Laboratory Dry Density as Determined by ASTM Test Method D 1557-91 (Modified Proctor), Unless Otherwise Specified in the Attached Report Text. Bedding Material; Material Type Depends on Type of Pipe and .�Oo- -0 Laying Conditions. Bedding Should Conform to the Manufacturers Recommendations for the Type of Pipe Selected. TYPICAL UTILITY TRENCH FILL 3ftF,arth Consultants Inc. Pepperwood & Nivinvui"val ","nimm Edmonds, Washington Prol. No. 10075 Drwn. GLS Date Apr. 2002 Checked RAC jDate 4/12/02 1PIate, 4 1 - L I _­ I - - j z 0 A 0 M .'M M1 APPENDIX A FIELD EXPLO-RATION E-10075 Our field exploration was performed on March 28, 2002. Subsurface conditions at the site were explored by observing a total of eleven test pit excavations. The test pits were excavated by a subcontractor of Phoenix Development, Inc. The approximate test pit locations were determined from existing landmarks presented on available plans. The locations of the test pits should be considered accurate only to the degree implied by the method used. These approximate test pit locations are shown on the Test Pit Location Plan, Plate 2. The field exploration was continuously monitored by a geologist from our office, who classified the soils encountered and maintained a log of each test pit, obtained representative samples, measured groundv\ater levels, and observed pertinent site features. All samples were visually classified in accordance with the Unified Soil Classification System that is presented on Plate Al, Legend. Logs of the test pits are presented in Appendix A, Plates A2 through Al2. The final logs represent our interpretations of the field logs and the results of the laboratory tests of field samples. The stratification lines on the logs represent the approximate boundaries between soil types. In actuality, the transitions may be more gradual. Earth Consultants, Inc. z 0 M MAJOR GRA PH LETT Ell TYPICAL DESCRIPTION DIVISIONS 1;QV"Rr)I _qVMRCN Coarse Gravel And Gravelly Soils Clean Gravels (little or no lines) �0'�OAOA GW gW Well -Graded Gravels. Gravel -Sind Mixtures, Little Or No Fines 4111111, Ift GP gp Poorly -Graded Gravels, Gravel - Sand Mixtures, Little Or No Fines Grained Soils T More Than ore n.j. r % Coarse Praction Retained On No. 4 Sieve Gravels With Fines (appreciable amount of fines) j ��gm Silty Gravels, Gravel - Sand - Silt Mixtures �gc Clayey Gravels, Gravel - Sand - Clay Mixtures Sand And Sandy Clean Sand (little or no lines) 000 000 — SW _�� SW I Well -Graded Sands, Gravblly Sands, Little Or No Fines rf'_Nlrv� Poorly -Graded Sands, Gravelly More Than Soils 50% Material Larger Than More Than No. 200 Sieve 50% Coarse Sands With Size Fraction Fines (appreciable Passing No. 4 amount of fines) Sieve Fine Silts Liquid Limit Grained Arid Less Than 50 Soils I Clays More Than 5o% Material Silts S 11 TI, Liquid Limit ma"e' ' an And Greater Than 50 No. 200 Sieve Clays Size Highly Organic SOU SP Sands. Little Or No Fines SM Silty Sands. Sand - Silt Mixtures SM 3C Sc Clayey Sands, Sand -Clay Mixtures M L Inorganic Silts a Very Fine Sands, Rock Flour,Silty- Clayey Fine Sands; Clayey Silts wl Slight Plasticity CL Inorganic Clays Of Low To Medium Plasticity, Cl Gravelly Clays, Sandy Clays, Silty Clays, Lean �01 Organic Silts And Organic Silly Clays of Low. Plasticity I MH Inorganic Silts. Micaceous or Diatomaceous Five Sand or Silly Soils son mill jhv�' Clays Of High �InorgaNc c h Plasticity, Fat Clays. ? 0 Organic Clays Of Medium, To High Plasticity, Organic Silts Peat, Humus, Swamp Soils With High Organic Contents Topsoil Humus And Duff Layer Hk,hly Variable Constituents Fill The discussion in the text of this report is necessary for a proper understanding of the nature of the material presented in the attached logs. DUAL SYMBOLS are used to Indicate borderline scill classification. C TORVANE READING, tsf 2- O.D. SPLIT SPOON SAMPLER qu W PENETROMETER READING, tsf MOISTURE, % dry weight 24" I.D. RING OR SHELBY TUBE SAMPLER P SAMPLER PUSHED SAMPLE NOT RECOVERED WATER OBSERVATION WELL pef LL DRY DENSITY, lbs. per cubic ft. LIQUID LIMIT, % sz DEPTH OF ENCOUNTERED GROUNDWATER PI PLASTIC INDEX DURING EXCAVATION T SUBSEQUENT GROUNDWATER LEVEL W/ DATE Earth Consultants Inc. utimiiuikad 1-�1911kvf-s. 16 121VII(MMIX111111 '""'bAs LEGEND Proi. No. 100751 Date Apr. 2002 1 Plate Al Z 0 0 M 0) 0 171 C M 0 --i C-) 0 C M M Z C _Z 0 M M 0 0 0 M C cl) 9 C/) M 0 Z ;U Z Z 0 i 0 M Test Pit Log Project Narne: Sheet of Pepperwood 1 1 Job No. Logged by: Test Pit No.: 10075 1 KCS __�j 8102 _ _ TP-1 Excavation Contactor: Ground Surface Elevation: Universal Land 420' Notes: Surface Conditions: Depth of Topsoil & Sod 4": grass General w Z CL E CL U E co 0 E cn Noles (0/6) >' (n M in 0 U>. SM Brown silty SAND with gravel, loose, moist 13.3 2 -30% fines 3 ....... 4 ML Gray sandy SILT, medium dense, moist 16.4 ... ­7 5 SM -mottlin at 5' Gray s& SAND, medium dense to dense, moist 15A 6 14.5 Test pit terminated at 7.5 feet below e)dsbng grade. No groundwater encountered during excavation. NOTES: Elevations estimated by a TopograThic Site Plan provided by the E Client. Survey by Group Four Inc. ated 116/99. Uj Test Pit Log Earth Consultants Inc. Pepperwood Edmonds, Washington �i April 2002 Checked KCS Date 4/10/02 .�,pral.r1,10075,J Dwn. GLS Date I Plate I __ _ _ ied by engineering tests, analysis and d'i. cted represent our observations at the time and location of this e)#oratory hote, modif �urf or� Ah' —.Mfh� nf r4har fimr—z and locations. we cannot accept responsiblity for the use or interpretation by others of z 0 m _-A Test Pit Log Project Narne: Sheet of Pepperwood Job No. Logged by: Test Pit No.: 10075 1 KCS !8102 TP-2 Ocavabon Contactor Ground Surface Elevation: Universal Land 424' Notes: Surface Conditions: Depth of Topsoil & Sod 10": ferns General W IZ CL E _E 'WL 0 5 n E Notes ff >' 0 U) M 0 (n D. >1 CO SM Brown silty SAND with gravel, loose, moist 2 -roots may e)dend to 3' 3 mottling at 4' 4 __§M Brown silty SAND, dense, moist 11.9 -15% fines 6 7 Test pit terminated at 7.0 feet below e)dsting grade. No groundwater encountered during excavation. Test Pit Log Earth Consultants Inc. Pepperwood & Edmonds, Washington 1002 4/10/02 No. 10075 Dwn. GLS Checked KCS TD Subsurface conditions depicted represent our observations at the time and location of this e)ploratory hole, modified by engineering tests, analysis and !-1- --A �­ __ __# - —i �f ofiva nf dhi-r f imf_-, and locations. we cannot acceot responsibility for the use or interpretation by others of z 0 0 m Test Pit Log Project Name: Of Pepperwood Job No. Logged by: Date: Test Pit No.: 10075 1 KCS 3/28/02 TP-3 bcavation Contactor Ground Surface Elevation: Universal Land 416' Notes: _0 Surface Conditions: Depth of Topsoil & Sod 2": trees and ferns General w J2 CL -0 E cEL U) E Notes M , a - Cn 0 (n >' CO SM Brown silty SAND with gravel, loose, moist 10.6 2 -with some organics roots 3 -mottling and iron o)dde staining at 3' 4 SM Gray silty SAND with gravel, dense, moist 7.1 6 Test pit terminated at 6.0 feet below e)dsfing grade. No groundwater encountered during e)cavation. IL 0 Test Pit Log Earth Consultants Inc. Pepperwood Edmonds, Washington ----FDwn. .1 proi. No. 10075 GLS I Date April2002 Checked KCS Piate A4 Subsurface conditions deplaea represent our ooservations at ine time am tuldut.- v, ulla vAp"o—Y 11�w. -Y 'Ron by others judgment. They are not necessarily representative of other times and locations. We cannot accept responsibility for the use or i�OrWd i Of lnf�mof;^n rw��#M � flile 1� z 0 4 0 M Test Pit Log Project Name: Sheet Of Pepperwood Test Pft No.: Da�te: Job No. Logged by: 10075 - I KCS 3/28/02- 1 r-q Excavation Contactor Ground Surface Elevation: Universal Land 404' Notes: Surface Conditions: Depth of Topsoil & Sod 4!': brush debris General W r- .0 CL E VL -; CL E U) E Notes (OA) (-n v LL 0 CO U) n :3 >. SM Brown silty SAND with gravel, loose, moist 2 3 4 11.2 -§P—�M B Iwn poorly graded SAND with silt and gravel, medium dense, moist, 5% fines 7.7 6 Gray silty SAND with gravel, dense, moist to wet 16.9 7 8 Test pit terminated at 8.0 feet below e)dsbng grade. No groundwater encountered during excavation. W Test Pit Log C, (MEArthCOrISUItMtS Inc. Pepperwood Croed FJIVIr" IMMIr'll "KIM ltb;m' Edmonds, Washington t (L. 1;i W oj. No. 10075 rp-roj Dwn. GLS Date April 2002 1 checked KCS Date 4/10/02 Plate A5 depicted represent our observations at the time and location . I. I .. - —6;— of this exploratory hole, modified by engineering tests, analysis and AA/m �nnrJ Priy" ri*qnonsibilftv for the use or interDretation by others of Subsurface conditions judgment. i ney are not neumbdilly IUPIUbUIILOU� VI —I... 111— z 0 i 0 m ff. Test Pit Log Project Name: Sheet Of Job No. Logged by: Date: Test Pit No.: 10075 KCS 3/28102 TP-5 Excavation Contactor: Ground Surface Elevation: Universal Land 395' Notes: U — W Surface Conditions: Depth of Topsoil & Sod 2": grass 0 = — General W z -0 '� j CL CL E 4D E E Notes >1 0 >' (0/6) U) Cn (n SM Brown silty SAND with gravel, loose, moist 2 3 SM Brown silty SAND with gravel, occasional cobbles, medium dense, 4 moist 10.8 T 5 6 -mottling at 7' 7 10.8 SM Gray sil!y SAND with gravel, dense, moist (Weathered Till) Test pit terminated at 7.5 feet below e)dsting grade. No groundwater encountered during excavation. C4 12 . .... . .. ...... Test Pit Log 8 Earth Consultants Inc. Pepperwood cokv;ts kim b;N Edmonds, Washington .... . .. . . ...... .. ..... tu Prcj. No. 10()'Iil'"'151� Dvn. GLS Date April2002 Checked KI ti Date 4/10/02 plate A6 I Subsurfloe conditilon's depicted represent our observations at the time and location oT ints expioralory nole, modified by engineering tests, analysis and ju�Mn,t�= are not necessarily representative of other times and locations. We cannot accept responsi0i ity for the use or interpretation by others of �fowi ^M fhk U-t z 0 A 0 M Test it Loa Project Narne: Sheet Of Peppetwood - -- — 1 1 1 Job No. Logged by: Date: Test Ph No.: 10075 1 KCS 3/28/02 TP-6 Excavation Contador. Ground Surface Elevation: Universal Land —1-395' Notes: -6 Cn Surface Conditions: Depth of Topsoil & Sod 2": grass General W q- n CL 0 E E t� E ch Notes CO U) U) SM Brown silty SAND with gravel, medium dense, moist 2 3 -some mottling at 3'- 4' 4-- — SP-SM Brown poorly graded SAND with silt, medium dense, moist 5 vel, dense, moist SM Gray silty SAND with q Test pit terminated at 5.5 feet below e)dsbng grade. No groundwater encountered during excavation. Test Pit Log 8 Earth Consultants Inc. Pepperwood 0 Edmonds, Washington 4/10/02 April 2002 Checked K Plate A7 Ui proi. No. 101375 Dwn. GLS Date Subsurface con(rdions depicted represent our observations at the time and location of this exploratory hole, modified by engineering tests, analysis and L — * .. —41.4;— IN" �nnrd nnPPH m-qnonsibilitv for the use or interpretation by others of ju*jment. iney are not nuuabbailly iw—' z 0 M Test Pit Log Project Name: Sheet Of 1- Pepperwood 1 1 Job No. - Logged by: Date: Test Pit No.: 10075 1 KCS 3/28/02 1 TP-7 bravation Contador Ground Surface Elevation: Universal Land 1 408' Notes: 0 Surface Conditions: Depth of Topsoil & Sod 2": grass General W .0 CL E jrL CL LL E 0 .0 Cn E Notes (%) E - U) (n A SM Brown silty SAND with gravel, loose, moist SP Brown poorly graded SAND With gravel, dense, moist 5.9 2 3 0 4 :: 4 SM Gray silty SAND with gravel, dense, moist Test pit terminated at 5.5 feet below existing grade. No groundwater encountered during excavation. W Test Pit Log 8 Eanh Consultants Inc. Pepperwood C1-~-U--.& FJIARX III %M9,11 It"S Edmonds, Washington Proj. No. 10075 Dm. GLS Date April2002 Ched(ed KCS 4/10/02 Plate A8 but)sunaoe conamons oepK;tea represent out L%)bWV-dlKAth dt tilt; illitU Cillu ruk'at— � ...... -1 ' h of judgment. They are not necessarily representative of other times and locations. We cannot accept responsibility or the use or in erpretation by ot ers ,M,wmaftin- z 0 0 m