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Home My WebLink AboutGeoTech Report - BLD Engineering / Geo-tech Reports - 10/4/2006 Myers Bindynamics inc. MB — geotechnical engineering•geological sciences•coastal processes - ---- October 4, 2006 Mathew Coates, AIA Gus Lynch Coates Design 921 Hildebrand Lane, Suite 210 Bainbridge Island, WA 98110 Re: Geotechnical Report Proposed Berger Residence—417 NE Bear Creek DeWatto Road Belfair,Washington Dear Mr. Coates and Mr. Lynch: This letter report presents the results of our geotechnical investigations and analyses for the proposed Berger residence located at 417 NE Bear Creek DeWatto Road in Belfair, Washington. The purpose of out work was to conduct subsurface investigations and provide geotechnical recommendations for foundation support of the proposed residence. Our work was conducted in general accordance with our letter of agreement dated August 15,2006 and included project coordination, information review, a site reconnaissance,geotechnical explorations,analyses,meetings with you, and preparation of this letter report. Site and Project Description The subject property is an approximately 1.2 acre parcel that is irregular-shaped but roughly rectangular, oriented northeast to southwest. The property is accessed by a gravel road that extends south of NE DeWatto Road and enters the property via a gravel driveway on the northeast side of the site. The parcel is located in an area that slopes moderately down to the southeast. A level area has been excavated on the west central portion of the site to create a building pad. The building pad was apparently constructed by cutting and filling across the original site grade. Current project plans call for construction of a single-story residence on the level area that has been graded on the property. No significant additional site excavation or grading is anticipated as a part of the proposed residential development. The Site and Exploration Plan presented on Figure 1 shows the general configuration of the proposed residence. P011 INC B%) lWILDING I12 ISI:NRNh0KIVF BAINBRIDC&ISI_.4VD. WAS111NGION '06_S4_), h73 Site Investigations ^ The existing site conditions were assessed by conducting a'site visit and test pit explorations on September 12, 2006. Our site work and observations occurred following a period of prolonged warm,dry weather. During our site work we observed site topography,vegetation, drainage, and subsurface soil and groundwater conditions as described below. Tonographv As previously described, the subject property is located in an area that slopes moderately down to the southeast. Slope grades in the area range from 10 to 20 degrees (18 to 36 percent)with locally steeper and flatter areas generally where grading has occurred for residential development. In the central portion of the subject property, a level area had been created by cutting and filling. The level area is oval shaped, approximately 50 feet wide and over 100 feet long as shown on Figure 1. Cut and fill heights based on visual observations appear to be a maximum 5 to 6 feet high. The cut and fill slopes are generally steep with average grades of 45 to 35 degrees,respectively. Vegetation Site vegetation around the proposed building envelope ranges from relatively undisturbed forest conditions on the perimeter of the property, to the central cleared building envelope,to disturbed forest conditions on the east side of the site where the access drive and on-site wastewater treatment system have been installed. Forested areas consist of established conifer and deciduous trees and a variable understory of sword ferns, woody shrubs and groundcover. Hydrophytic(water loving)vegetation is located on the slope immediately above the building pad to the northwest. Uniformly aged sapling alder trees along with an understory of hydrophytic vegetation is also located on the slope below and southeast of the building pad. Drainage Standing surface water was observed on the level building pad at the time of our visit. The water was generally located on the northwest side of the pad, adjacent to the cut slope. Daylighting groundwater seepage was observed on the cut slope. Since our site work occurred at the end of the dry summer season, it appears the origin of the standing surface water is the daylighting groundwater seepage from the cut slope. The hydrophytic (water-loving) vegetation observed on the slope indicates that prolonged, wet soil conditions are likely present on the site northwest and southeast of the building pad. A shallow curtain drain was reportedly installed on the northwest side of the level area near the toe of the cut slope. A 4-inch diameter PVC pipe was observed on the southwest edge of the level area,reportedly the discharge pipe for the curtain drain. The curtain drain discharged into a broad natural drainage area on the slope that Ceotechnical Report Project No. 061327-5 Proposed Berger Residence page 2 of 7 October 4, 2006 Bey'air, Washington - Myers Biodpnamics, Inc. descends to the southwest. At the time of our site visit, water flow from the curtain drain discharge pipe was estimated at one-quarter of a gallon per minute. Generalized Subsurface Soil and Groundwater Conditions Subsurface conditions for the project site were explored by advancing six test pit explorations on September 12,2006. The explorations were located on the proposed building pad area at the approximate locations shown on Figure 1. Soil conditions observed in the test pits generally consisted of a layer of surface fill ranging from 2 to 6 feet thick. Although test pits on the northwest side of the building pad were in a cut area,it appeared that the original site excavation was lower,with subsequent fill placement. Below the fill, several test pits on the south side of the site exhibited a layer of topsoil,covered by the fill. Below the fill and topsoil, site soils were composed of medium dense to dense granular soils ranging from sand and gravel to silty fine sand. The approximate fill and topsoil thickness and depth to medium dense native soils at each of the test pit locations are shown on Figure.1. Groundwater was encountered in all the test pits, except TT-4. Evidence of seasonal groundwater was also observed in TP-4. Groundwater seepage was observed generally below the level of the fill and topsoil at depths of 2 to 6 feet below existing grade as shown on Figure 1. Soil staining indicated that groundwater levels are likely higher during the wet season. Groundwater conditions will likely change depending on the season, precipitation, and other on-site and off-site factors. Slope Stability Evaluation _ Observation of the site indicated that the moderately steep slopes are underlain by granular soils in a medium dense to dense condition. These soils have a low risk of slope instability and are suitable for support of the proposed residence assuming adequate burial of foundations. The fill placed on the southeast side of the site to form the relatively level building envelope is in a loose condition and underlain at times by topsoil. In our opinion, the loose fill located on the southeast side of the site has a relatively high risk of erosion and a moderate risk of localized soil slumps(small landslides). This opinion is based on the relatively loose condition of the fill,the steep fill slope,the presence of topsoil below the fill, and groundwater. However, if surface water and shallow groundwater can be controlled and routed away from the fill, risk of slope instability can be significantly reduced. Also, shaving back the crest of the steep fill slope and/or establishing vegetation can help reduce shallow slope instability risk. Geotechnica!Report Project No. 061327-5 Proposed Berger Residence page 3 of*7 October 4, 2006 Belfair, Washington - Myers Biodynan:ics, Inc. Geotechnical Engineering Recommendations Geotechnical engineering recommendations presented in the following sections are based on the results of subsurface exploratioQs and our understanding of the proposed project at the time this report was prepared. Recommendations include foundation support, lateral resistance,drainage,and vegetation management considerations. Foundation Support For slope stability considerations, we recommend foundation support for the proposed residence and deck be provided by embedment in the medium dense or denser granular soils located below the fill and buried topsoil. Depth to suitable foundations soils at the test pit locations is shown on Figure 1. An allowable bearing pressure for spread footing foundations of 2,000 pounds per square foot(psf)is recommended for the medium dense or denser site soils. Once exposed, spread footing foundation subgrade soils should be compacted to a firm condition. If soft, wet,loose,or organic soils are present,they should be overexcavated and the footings extended down to firm native soil. We recommend a minimum width for spread footing foundations of 24 inches for isolated footings and 18 inches for continuous(wall)footings. Allowable soil bearing pressures may be increased by one-third to include short-term loads such as seismic or wind loading. Spread footings should be embedded at least 18 inches below adjacent finished grades or in the medium dense or denser native soils as shown on Figure 1, whichever is deeper. Foundation drainage systems should be provided for all spread footings as recommended below. Due to the relatively large depth to suitable foundation soils(6 feet)on the southeast side of the site,drilled pier foundations could be considered for residential foundation support. Drilled piers should extend a minimum 5 feet into the medium dense granular soils on the southeast, northeast, and southwest sides of the proposed residence (total pier depth below existing grade of approximately 9 1/2 to 11 feet at the test pit locations). Elsewhere, a minimum 2 feet of penetration into the suitable foundations soils is recommended for the northwest side of the residence and the office and garage area(pier depth below existing grade of 4 to 4 1/2 feet). We recommend a maximum allowable soil bearing pressure of 5,000 psf for the pier foundations assuming a minimum 5 feet of penetration into the medium dense or denser native soil. The recommended pier bearing pressure assumes pier diameters of 18 to 24 inches. We anticipate total settlement of spread footings and drilled piers will be I-ineh or less and differential settlement between foundation elements will be less than 1/2-inch. This assumes proper subgrade preparation and foundation construction techniques are utilized. The majority of settlement is expected to occur during construction as the loads are applied. It is imperative that the bottom of the footing and/or drilled pier foundations be free of loose soil or slough prior to concrete placement to avoid excessive settlement. If Geotechnical Report Project No. 061327-5 Proposed Berger Residence page 4 of 7 October 4, 2006 Belfair, Washington - Myers Biodynamics, Inc. groundwater is present, drilled piers may require casing to maintain an open hole. Also, concrete should be placed by tremmie method if groundwater is present. Lateral Resistance Lateral loads may be resisted by a combination of friction along the base of foundations and by passive soil resistance against buried foundations. We recommend shallow footings founded on native granular site soils be designed using an ultimate coefficient of base friction of 0.40. Passive soil resistance for compacted backfill around footings or for the portion of drilled piers embedded in undisturbed native soils be calculated based on an equivalent fluid of 280 pcf. The passive value includes a factor of safety of 1.5 to reduce the magnitude of lateral movement required to fully mobilize passive resistance. Passive resistance in the upper 1 foot should be ignored. On the southeast side of the residence we recommend ignoring passive resistance for the full height of the fill and topsoil. Passive resistance of the embedded portion of the drilled piers in the native soil can be assumed to act over 2 pier diameters. Due to the potential for loss of ground on the down slope side of the residence foundations, we recommend the foundations be capable of resisting lateral loads from soil retained behind the foundation subgrade wall or drilled piers. We recommend using an equivalent fluid of 55 pct which assumes "at- rest" conditions when the top of the foundation wall is restrained. At-rest earth pressures can be assumed to act over one pier diameter. Drainage Considerations Control of surface water runoff and groundwater on the subject property that flows toward the fill slope is an important mitigation measure to help reduce erosion and slope instability risks. We recommend site surface water runoff from roof, driveway, and other areas be collected,and routed to a suitable discharge location such as the existing natural drainage on the southwest portion of the property, southwest of the proposed residence, or other suitable discharge locations. Appropriate energy dissipation and/or erosion control measures should be utilized at the pipe discharge locations. We recommend subsurface drainage be provided for footings and behind any foundation subgrade walls. Footing drains should be constructed at the exterior edge(around the perimeter) of the proposed structures. In addition, if continuous spread footing foundations are used for the residence,we recommend that subgrade wall drainage also be installed on the northwest, inboard side of the foundations along the southeast side of the residence. This additional drainage is recommended because the foundations will be required to step down below the fill/topsoil and could be subject to a buildup of hydrostatic forces from groundwater. We recommend footing and subgrade wall drains consist of perforated PVC pipe surrounded by at least 6 inches of drain gravel. For the subgrade wall on the inboard, southeast side of the residence,the drain gravel or other drainage material such as a geocomposite drain mat should extend for the full height of the subgrade wall. The drain gravel should be surrounded by a suitable filter fabric, such Ceotechnical Report Project No. 061327-5 Proposed Berger Residence page 5 of 7 October 4, 2006 Bel(air, Washington Myers Biodynamics, Inc. � f as Mirafi 140N, with a 12-inch minimum overlap. Clean-outs should be provided to extend.the useful life of all drainage systems. In addition to footing and subgrade wall drains, we recommend re-installation of a surface swale and groundwater interceptor trench(curtain drain)along the northwest side of the building pad. The purpose of the curtain drain is to capture and route surface water from the daylighting groundwater on the cut slope and to intercept groundwater at depth below the fill that could adversely affect slope stability. We recommend that the curtain drain extend a minimum 6 feet below the existing grade on the level portion of the site. The bottom of the curtain drain should be sloped down towards the proposed discharge location(s). The curtain drain should be composed of perforated PVC pipe with a minimum 6-inch drain gravel surrounding the pipe and extending up to near the finished site grade. The-drain gravel should be fully surrounded by suitable filter fabric with a 12-inch overlap. The top of the trench could have a separate,`additional layer of filter fabric and a layer of gravel to line the surface swale and allow for future removal of surface gravel if it becomes clogged by fine soil particles. The swale and curtain drain should transition to q catC h asiifi d tightline discharie t pipe prior to routing the water onto the natural site ramage Swale. Vegetation Management and Fill Regrading ° Vegetation on the site can help reduce the rate and volume of surface water runoff. Vegetation root systems also help to reinforce shallow slope soils and can reduce erosion. We recommend establishing erosion control materials and native vegetation on the fill slope face and crest. Maintain vegetation on the slope and use methods of vegetation limbing and trimming,rather that clearing for view purposes. If possible, regrade the fill slope to a flatter configuration by shaving back the top of the slope prior to placing erosion control material and vegetation. Recommendations for Additional Service Prior to construction, we recommend geotechnical review of the project plans that pertain to the foundation support and drainage to determine that they are consistent with the recommendations presented herein. We also recommend that construction consultation be performed to confirm that conditions encountered on the project site are consistent with those indicated by the site explorations, to provide recommendations should site conditions be revealed during construction that differ from those anticipated, and to evaluate whether construction activities comply with project plans. Geotechnical Report Project No. 061327-5 Proposed Berger Residence page 6 of 7 October 4, 2006 Belfair, Washington Myers Biodynamics. Inc. Closure This report was prepared for the exclusive use of Coates Design and other project team members for specific application to the property identified herein. The data and report should be provided•to prospective contractors for their information but the report conclusions and interpretation should not be construed as a warranty of subsurface conditions. Within the limitations of scope, schedule, and budget, this report was prepared in accordance with generally accepted geotechnical engineering principles and practices in the area at the time this report was prepared. No other warranty, either expressed or implied, is made. The conclusions and recommendations presented herein are based on our understanding of the project as described in the report and conditions observed at the time of our explorations. If project plans change from those described in this report,we should be contacted and retained to review the changed conditions. Also,we should be contacted to review our work if. 1)there is a substantial lapse of time between submission of this report and the start of construction; 2) conditions have changed due to natural causes or other operations at the,site; or 3) conditions appear different from those described in our report. The purpose of the review is to determine the applicability of the conclusions and recommendations considering the time lapse or changed conditions. We appreciate the opportunity to provide continued geotechnical engineering services for you. Please contact our office at your convenience should you have any questions or require additional services. Sincerely Yours, MYERS BIODYNAMICS, INC. �� - --�,,:;'�� /�ry,./��-•_r fit;. r� e N. Myers, E.G. Principal Geotechnical Engineer ' c Attachments --- Geotechnical Report Project No. 061327-5 Proposed Berger Residence page 7 of 7 October 4, 2006 Belfair, Washington - Myers Biodynamics Inc. APPENDIX A Appendix A Field Exploration Program Subsurface conditions for the project site were explored by excavating six test pit explorations, TP-1 through TP-6, at the approximate locations shown on the Site and Exploration Plan,Figure 1. Subsurface conditions observed in the explorations are presented on the logs attached to this Appendix as Figures A-1 through A-6. No survey control was present on the project site. The explorations were located in the field by taping or pacing relative to the existing septic tank locations as shown on "Site Plan, Berger Residence,417 NE Bear Creek Dewatto Road,Belfaii, WA prepared by Coates Design dated August 24, 2006. No site topographic elevations were available for the site but test pits were generally at a similar elevation on a level area previously graded on the site. The location of the explorations should be considered accurate to the degree implied by the method used. A licensed engineering geologist/geotechnical engineer from Myers Biodynamics was present throughout the field work to observe the explorations,obtain soil samples, and to prepare field logs of the explorations. Soils were classified in general accordance with ASTM D-2488 "Standard Practice for Description and Identification of Soils(Visual- Manual Procedure)" and the Key to Soil Exploration Logs presented in this Appendix. A legend for the logs describing symbols and abbreviations is also shown on the Key. The exploration logs presented in this Appendix represent our interpretations and review of the contents of the field logs. Test Pit Explorations The test pit explorations TP-1 through TP-6 were advanced to depths of 4-1/2 to 8 feet by a track-mounted excavator on September 12,2006. The soils were classified and field logs prepared. The relative density of the soils, shown in parenthesis on the logs, was estimated in the field at the time of the explorations. Logs of the explorations are presented on Figure A-1 through A-6 attached to this Appendix. Groundwater conditions were noted during the field explorations. The groundwater level at the time of digging(ATD) is shown on the test pit logs. I i Geotechnical Report Project No.06 132 7-5 Proposed Berger Residence Appendix A October 4,2006 Beljair, Washington - Alyers Biodynamics. hic' L� Key to Soil Exploration Logs Unified Soil Classification System Sample Descriptions consist of the following: _ Well-graded gravels and Minor constituents, major constituents; density or °m GW gravel-sand mixtures,little m o or no fines consistency,color, moisture,and additional comments o mcc H y Poorly gradedqravels and including trace constituents. Soil classification is based — m m oa GP gravel-sandmlxtures,little o L' Q c U or no tines Z4 o' on visual field soil sample observations and laboratory =S � Silty gravels, results on selected samples, where indicated on the m z GM gravel-sand-silt mixtures logs. Soil classification is based on grain size,plastic- �; c�3 GC clayey gra vets, = gravel-sand-clay mixtures ity, color, density/consistency, and moisture. Visual- y Well-graded sands and y manual methods of ASTM D2488 were used as an a m m N SW gravely sands,little or no s_._ _� a,my may Ira identification guide. a= m y ro Poorly graded sands and wo v U S P gravelly sands,little or no Soil Density and Consistency o o o fines Soil density/consistency in borings is related to the a m� 3 H SM Silty sands,sand-silt mixtures Standard Penetration Test(SPT) as shown below. Soil SC clayey sands,sand clay density/consistency estimates in test pits are based on y mixtures visual observation and presented parenthetically on the h Inorganic silts,very fine M L sands,rock flour,silty or soil logs. o.y r clayey fine sands m z g U m Inorganic clays of low to a— medium plasticity,gravely Coarse-Grained Fine-Grained =z E CL clays,sandy clays,silty m y clays,lean clays Soil Density SPT Soil Consistency SPT* �� .,_ a OL Organic silts and organic Very Loose 0-4 Very Soft 0-2 silty clays of low plasticity Loose 4-10 Soft 2-4 y m Medium Dense 10-30 Medium Stiff 4-8 m E H m M H Inorganic sous,micaceous diatomaceous tine sand or y U silty soils,elastic silts Dense 30-50 Stiff 8-15 Very Dense >50 Very Stiff 15-30 CH Inorganic clays of high e m m r plasticity,fat clays Hard >30 i a " 'Standard Penetration Test measured in blows per foot E in i O H Organic clays medium to high plasticity Peat,muck and other Highly Organic Soils Pt Minor Constituents Estimated Percentage highly organic soils Trace" 0-5% Slightly(Silty, Sandy, etc.) 5-12% Clayey, Silty, Sandy, Gravelly 12-30% Observation Well Symbols Very(Silty, Sandy, etc.) 30-50% Bentonite "Not identified as a Minor Constituent seal 8rr/92 v Ground Water Level: Moisture = date of reading ATD 0 ATD:At Time of Drilling Dry Little to no perceptible moisture Sand pack and well Slightly y Some perceptible moisture,probably below optimum screen or hydrotip Moist Moisture content probably near optimum Boring Symbols most Much perceptible moisture,probably above optimum 2.0"dia.Split Spoon Wet Visible free water S-1 24 Sampler(SPT) 27 3 3.25"dia. Split Barrel Laboratory Test Symbols S-2 50 Ring Sampler MC Moisture Content 50/4' GS Grain Size classification S-3 3.0"dia. Thin Wall AL Atterberg Limits P Tube Sampler PP Pocket Penetrometer(compressive strength in TSF) P= Sampler pushed 'No sample recovery TV Torvane(shear strength in TSF) Test Pit Symbols CN Consolidation TUU Triaxial Unconsolidated Undrained S-1 Sample number Grab Sample(jar or bag) TCU Triaxial Consolidated Undrained TCD Triaxial Consolidated Drained 5 Ground Water seepage OU Unconfined Compression v Ground Water level observed in test pit excavation DS Direct Shear K Permeability Myers CBR California Bearing Ratio Bindgnamics inc. MD Moisture Density Curve - MH Roiling Bay Mercantile Building•11254 Sunrise Drive N Nutrients TEL:20M42-6073 FAX 0SM42-3797 TEST PIT LOG T P 1 This log applies only to test pit location at the time of excavation. Subsurface conditions may differ at other locations and may also change over time. This log is a simplified interpretation of the actual conditions. Berger Residence a Belfair, Washington a 2 TEST PIT LOCATION: See Figure 1 SURFACE CONDITIONS:Crushed rock/surface water 0 u) DESCRIPTION COMMENTS crushed rock surfacing surface water flowing into test pit 1 — FILL: Gravelly Silty SAND: (loose to medium dense), S-1 brown, very moist, trace to few organics 2- s 2 Gravelly Sand to Slightly Silty Fine SAND,(loose to medium dense), gray, very moist to wet, orange staining on north side of test pit 3- S-3 Sand and Gravel,(medium dense), orange, wet trace groundwater seepage from 3 foot depth to bottom 4— of test pit Bottom of test pit at 4 112 foot depth 5— Completed and backfilled 9112106 6- 7- 8- 9- 10- 11 - 12- 13- 14- 15- 16- 17- 18- Rolling Bay Mercantile Bldg. Myers 11254 Sunrise Drive DATE 9/12/06 FIGURE A-1 40�* Biodynamics inc. Bainbridge Island WA 98110 ELEVATION(FT) IF NO MB Bus:(206)842-6073 FAX:(206)842 3797 U11kC10WC1 061327-5 TEST PIT LOG T P 2 This log applies only to test pit location at the time of excavation. Subsurface conditions may differ at other locations and may also change over time. This log is a simplified interpretation of the actual conditions. tz W Berger Residence = J Belfair, Washington wa a TEST PIT LOCATION: See Figure 1 SURFACE CONDITIONS:Crushed rock o to DESCRIPTION COMMENTS crushed rock surfacing 1 - S-1 FILL:Gravelly Silty SAND; (loose to medium dense), brown, very moist, trace to few cobbles 2- S_2 Gravelly SAND to Slightly Silty Fine SAND; (medium dense), gray, very 3— moist 4- S-3 Very Gravelly SAND to Sandy GRAVEL; (medium dense), gray and trace groundwater seepage orange, wet, few cobbles, trace boulders from 3'8"depth to bottom 5— of test pit 6- 7- Bottom of test pit at 7 foot depth 8- Completed and backfilled 9112106 9- 10- 11- 12- 13- 14- 15- 16- 17- 18- Rolling Bay Mercantile Bldg. DATE 06 FIGURE Myers 11254 Sunrise Drive 9/12/ A-2 Bainbridge Island WA 98110 ELEVATION(FT) PROJECT NO Biodynamics inc. FAX:(206)842-3797 unknown 061327-5 MB BUS: (206)842-6073 TEST PIT LOG T P 3 This log applies only to test pit location at the time of excavation. Subsurface conditions may differ at other locations and may also change over time. This log is a simplified interpretation of the actual conditions. 1z W Berger Residence ii Belfair, Washington wa TEST PIT LOCATION: See Figure 1 SURFACE CONDITIONS:Crushed rock 0 to DESCRIPTION COMMENTS crushed rock surfacing S-1 FILL: Gravelly Silty SAND; (loose), dark brown, moist Fill thickens to the south 1 — towards the slope crest 2- S-2 TOPSOIL:Slightly Gravelly Silty SAND;(loose), dark brown, moist 3- s-3 Gravelly Slightly Silty SAND,(loose to medium dense), red brown, slightly moist, trace to few gravel and cobbles, trace to few fine roots 4- 5- S-4 Slightly Silty Fine SAND;(loose to medium dense), red brown, moist, trace organics, roots fine to 3"dia. 6- Gravelly Slightly SAND; (medium dense), light brown, very moist, trace groundwater seepage from to few cobbles and boulders 7 foot depth to bottom of 7— test pit s-5 Very Gravelly SAND; (medium dense), brown to red brown, wet, trace cobbles and boulders 8- Bottom of test pit at 8 foot depth s— Completed and backfilled 9112106 10- 11 - 12- 13- 14- 15- 16- 17- 18- Rolling Bay Mercantile Bldg. Myers 11254 Sunrise Drive DATE 9/12/06 FIGURE A-3 _Biodynamics inc. Bainbridge Island WA 98110 ELEVATION(FT) PROJECT NO MB BUS: (206)842-6073 FAX:(206)842-3797 unknown 061327-5 TEST PIT LOG T P 4 This log applies only to test pit location at the time of excavation. Subsurface conditions may differ at other locations and may also change over time. This log is a simplified interpretation of the actual conditions. IZ W Berger Residence a Belfair, Washington w a TEST PIT LOCATION: See Figure 1 SURFACE CONDITIONS:Crushed rock and grasses o cn DESCRIPTION COMMENTS crushed rock surfacing 1 FILL: Silty Gravelly SAND; (loose to medium dense), light gray brown to S-1 brown to red brown, stained at bottom of layer, trace fine roots 2- 3- 4- 5— TOPSOIL:Slightly Gravelly Silty SAND;(loose), dark brown, very moist, abundant organics, wood debris to 1 112"dia. 6— S-2 Gravelly Slightly Silty to Silty SAND, (dense), light gray and brown, very moist, stained and mottled 7— Bottom of test pit at 7 foot depth 8— Completed and backfilled 9112106 9- 10— 11 — 12— 13- 14— 15— 16— 17- 18— Rolling Bay Mercantile Bldg. Myers 11254 Sunrise Drive DATE 9/12/06 FIGURE A-4 Bindynamics inc. Bainbridge Island WA 98110 ELEVATION(Fr) PROJECT NO #� '-MB BUS:(206)842-6073 FAX:(206)842-3797 unknown 061327-5 TEST PIT LOG T P 5 This log applies only to test pit location at the time of excavation. Subsurface conditions may differ at other locations and may also change over time. This log is a simplified interpretation of the actual conditions. W Berger Residence a Belfair, Washington wa TEST PIT LOCATION: See Figure 1 SURFACE CONDITIONS: Crushed rock and grasses o u) DESCRIPTION COMMENTS crushed rock surfacing 1 FILL:Gravelly to Very Gravelly Silty SAND; (loose to medium dense), gray brown to red brown, moist, trace cobbles, trace fine roots 2— S-1 3- 4— TOPSOIL:Slightly Gravelly Silty SAND, (loose), dark brown, very moist trace fine roots 5— Gravelly to Very Gravelly Slightly Silty SAND; (medium dense to dense), brown, very moist to wet, trace cobbles and boulders 6— s 2 trace orange color at bottom of test pit trace groundwater seepage foot 7— at 7 depth Bottom of test pit at 7 foot depth e— Completed and backfilled 9112106 9- 10— i 11 — 12— 13— 14— I 15— 16— 17— 1a— Rolling Bay Mercantile Bldg. LMyers 11254 Sunrise Drive DATE 9/12/06 FIGURE �iw-5 Bindynamics inc. Bainbridge Island WA 98110 ELEVATION(FT) PROJECT NO MB BUS: (206)842-6073 FAX:(206)842-3797 unknown 061327-5 TEST PIT LOG T P 6 This log applies only to test pit location at the time of excavation. Subsurface conditions may differ at other locations and may also change overtime. This log is a simplified interpretation of the actual conditions. 1z W Berger Residence = J Belfair, Washington wa a TEST PIT LOCATION: See Plan SURFACE CONDITIONS: Crushed rock o cn DESCRIPTION COMMENTS crushed rock surfacing 1 FILUDISTURBED SOIL: Gravelly Silty SAND; (loose to medium dense), S-1 brown and red brown, very moist, trace scattered roots 2- occasional TOPSOIL lenses with trace roots from 2 112 to 3 foot depth 3- Gravelly to Very Gravelly Slightly Silty SAND, (medium dense), brown, s-2 very moist to wet 4- groundwater seepage at bottom of test pit Bottom of test pit at 4 112 foot depth 5_ Completed and backf fled 9112106 6- 7- 8- 9- 10- 11 - 12- 13- 14- 15- 16- 17- 18- Rolling Bay Mercantile Bldg. DATE FIGURE Myers 11254 Sunrise Drive 9/12/06 A-6 Biodynamics inc. Bainbridge Island WA 98110 ELEVATION(FT) PROJECT NO MB Bus:(206)842-6073 FAX:(206)842-3797 ^ unknown 061327-5 r } � TP-1 � �J � TP-2 (2'/2') (2�/2Q 3 Approximate Toe — �Z 4' -- - of Cut Slope aein ---------- TP-6 (2 1/2'/2 1/2') Y- 4 1/2' LI) T I KiTCHEN ... i DININCo LIMNG (�(� �r•\ / MAST BED ..----- _ _... _ .- - -- - --D --n _ -II TP-3 (2 1/2'/6) TP-5 (4 1/2 /4 1/2') I ---- SZ 7 5 1/2' i i I Approximate Crest ' / n of Fill Slope i I J LEGEND: i i SFPT1C 1 g,X 2' TP-1 Approximate Test Pit Exploration Location --------'--------'------� (2'/29 Depth in feet below existing grade of(fill and topsoil/suitable Approximate Scale: 1 foundation soils) -- -- 1 inch = 8 feet NOTE: Plan based on "Berger Residence, 417 Bear Creek DeWatto Rd.Belfair, WA", 4' Depth in feet below existing grade to groundwater seepage observed 9/12/06 0 4 g Site Plan, Scheme B-2, Coates Design, 921 Hildebrand Ln., Suite 210, Bainbridge Island, WA, 08124106. FIGURE NO. Myers GEOTECHNICAL REPORT 1 Biodynamics inc. Proposed Berger Residence SITE AND EXPLORATION PLAN PRQIECTN0.061327-5 N[B Rotting Bay Nor xntie RUIIAIng.11254 5unnc Drtw DATE V G J Bainbridge Island. ;h g� 1110 Belfair, Washington October 2006