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107 RAILROAD AVE.PDF107 RAILROAD AVE ADDRESS:11�1:�1 "40 kw,7011 TAX ACCOUNT/PARCEL #: BUILDING PERMIT (NEW STRUCTURE) #: COVENANTS (RECORDED) FOR: CRITICAL AREAS #: DETERMINATION: ❑ Conditional Waiver ❑ Study Required ❑ Waiver CRITICAL AREAS #: DETERMINATION: ❑ Conditional Waiver ❑ Study Required ❑ Waiver DISCRETIONARY PERMIT #'S: DRAINAGE PLAN DATED: PARKING AGREEMENTS DATED: EASEMENT(S) RECORD FOR: PERMITS (OTHER — list permit #'s): PLANNING DATA CHECKLIST DATED: SCALED PLOT PLAN DATED: SEWER LID FEE $: LID #: SHORT PLAT FILE: LOT: BLOCK: SIDE SEWER AS BUILT DATED: SIDE SEWER PERMIT(S) #: GEOTECH REPORT DATED: STREET USE/ENCROACHMENT PERMIT #: FOR: -WATER METER TAP CARD DATED: OTHER: L:\TEMP\DST's\Forms\Jana's Street File Checklist 5-14-08.doc RECEIVED JAN ENGINEERING DIVISION GEOTECHNICAL REPORT Lift Stations 7 and 8 Integration and Rehabilitation Edmonds, Washington HWA Project No. 2004-069-21 Prepared for HDR Engineering, Inc. January 11, 2006 JUL - s 2008 Ucr ry C °Emn�NDS =I I � HWAGEOSCIENCES INC. • Geotechnical Engineering • Hydrogeology • Geoenvironinentnl Services • Inspection d "Testing STREET FILE �•^�r:r wk` k - HWA GEOSCIENCES INC. Geotechnical Engineering • Hydrogeology • Geoenrironmcntn! Services Inspection Testing January 11, 2006 HWA Project No. 2004-069-21-1200 HDR Engineering, Inc. 500 108`h Avenue, Suite 1200 Bellevue, WA 98004-5549 Attention: Rudy Vigilia, P.E. Subject: GEOTECE LAICAL REPORT Lift Stations 7 and 8, Integration and Rehabilitation Edmonds, Washington Dear Mr. Vigilia We are pleased to submit this final geotechnical report for the Lift Stations 7 and 8 Integration and Rehabilitation Project. If you have any questions, please contact the undersigned at your convenience. Sincerely, . HWA GEOSCIENCES INC. Erik O. Andersen, P.E. Senior Geotechnical Engineer EOA:LAB:eoa AFf/I la� A0410 L.A. "Lome" Balanko, P.E. Vice President ;a 19730 64th Ayeriue W_'= Lynnwood WA 98036 5957 s', r '• sir '., Tel: 425 774 Ewww hwageosciences coIJ41 TABLE OF CONTENTS Page 1. INTRODUCTION.............................................................................................................1 1.1 GENERAL........................................................................................................I 1.2 PROJECT DESCRIPTION................................................................................... l 1.3 SCOPE OF SERVICES AND AUTHORIZATION....................................................I 2. FIELD AND LABORATORY TESTING..............................................................................2 2.1 EXPLORATIONS..............................................................................................2 2.2 LABORATORY TESTING..................................................................................2 3. SITE CONDITIONS.........................................................................................................2 3.1 SURFACE CONDITIONS....................................................................................2 12 GENERAL. GEOLOGIC CONDITIONS.................................................................3 3.3 SITE SOIL CONDITIONS...................................................................................3 3.3.1 New Sewer Alignment (West Dayton Street) ................................3 3.3.2 New Lift Station Location.............................................................3 3.4 GROUNDWATER CONDITIONS.......................................................................4 4. CONCLUSIONS AND RECOMMENDATIONS.....................................................................5 4.1 GENERAL........................................................................................................5 4.2 NEW GRAVITY SEWERS ON WEST DAYTON STREET.......................................6 4.2.1 General...........................................................................................6 4.2.2 Temporary Excavation Support .....................................................6 4.2.3 Trench Bottom Preparation and Bedding......................................7 4.2.4 Pipe Settlement and Buoyancy......................................................8 4.2.5 Backfill Material and Compaction.................................................9 4.2.6 Construction Dewatering...............................................................9 4.3 NEW LIFT STATION NORTH OF WEST DAYTON STREET.................................10 4.3.1 Temporary Shoring........................................................................10 4.3.2 Ground Water Control / Dewatering..............................................11 4.3.3 Lift Station Excavation..................................................................12 4.3.4 Buoyancy.......................................................................................12 4.4. SEISMIC CONSIDERATIONS 4.4.1 Liquefaction Susceptibility............................................................12 4.4.2 Code -Based Design Parameters.....................................................12 4.5 WET WEATHER EARTHWORK.........................................................................13 4.6 DRAINAGE AND EROSION CONSIDERATIONS..................................................14 4. CONDITIONS AND LIMITATIONS....................................................................................14 5. REFERENCES................................................................................................................16 Table of Contents (Continued) LIST OF FIGURES (FOLLOWING TEXT) Figure 1. Vicinity Map Figures 2 & 3. Site and Exploration Plan Figure 4. Geologic Profile along Centerline W. Dayton St. Figure 5. Cross Section A -A', Proposed Lift Station Figure 6. Typical Trench Section Figure 7. Parameters for Calculating Uplift Resistance Figure 8. Design Earth Pressures for Temporary Braced Shoring Appendices Appendix A: Field Exploration Figure A-1. Legend to Symbols and Terms Used on Explorations Figures A-2 - A-5. Logs of Borings BH-1 through BH-4 Figures A-6 - A-8. Slug Test Analysis Results Figures A-9 — A-11. Tidal Influence of Ground Water Results Appendix B: Laboratory Testing Figure B-1 - B-4. Grain Size Distribution Test Results Appendix C: Log of Previous Boring By Others 2004069 Final Report.doc ii HWA GEOSCIENCES INC. GEOTECHNICAL REPORT LIFT STATIONS 7 AND 8, INTEGRATION AND REHABILITATION EDMONDS, WASHINGTON 1. INTRODUCTION 1.1 GENERAL This report presents the results of a geotechnical engineering study for the Lift Stations 7 and 8, Integration and Rehabilitation Project. Our role in the project is to identify geotechnical conditions that will have an impact the project, and to provide design and construction recommendations for proposed structures. 1.2 PROJECT DESCRIPTION The existing Lift Station 7 (LS 7) is located on the south side of W. Dayton St., to the east of the Burlington Northern Santa Fe (BNSF) Railroad. It has reached the end of its useful service life and the wet well will be converted into a manhole structure. The replacement lift station will be located in the existing Sound Transit parking lot to the north of W. Dayton St. Preliminary information from HDR (2004) indicates the temporary excavation for constructing the lift station will have a footprint of approximately 25 ft by 25 ft, and will be approximately 15 ft deep. The existing 8-inch sanitary sewers on the north and south sides of W. Dayton St. need to be replaced due to excessive solid deposition, which is attributed to low gradients, and possibly to pipe settlements. Replacement sewers will also be 8-inch diameter, and will have a steeper gradient and will be deeper than the existing sewers. The new sewers will vary in depth from approximately 6 to 14 feet below existing ground surface. The project also includes rehabilitation of Lift Station 8, located to the north of the Amtrak Station. The rehabilitation includes 350 lineal feet of shallow 4-inch diameter force main. This report addresses the new gravity sewers on W. Dayton Street and the new Lift Station 7. 1.3 SCOPE OF SERVICES AND AUTHORIZATION The scope of work completed for the project included test borings, field and laboratory testing, and engineering analyses to develop geotechnical recommendations for the proposed pipelines. Our proposed scope of work, dated November 18, 2004, was authorized by Edmonds City Council on February 22, 2005. January 11, 2006 HWA Project No. 2004-069-21-1200 2. FIELD AND LABORATORY TESTING 2.1 EXPLORATIONS We drilled four test borings along the project alignment on March 2 and 3, 2005. The borings were designated BH-1 through BH-4 at the locations shown on the Site and Exploration Plans, Figures 2 and 3. Borings BH-1 through BH-3 were located on W. Dayton Street, and BH-4 was located in the west end of the parking area of the business at 111 W. Dayton Street, which is in close proximity to the proposed new lift station. A previous boring was drilled by CDM (2004) to the west of the proposed lift station for a study for Sound Transit. We located our B114 directly east of the then -proposed lift station to supplement the previous CDM boring. However, subsequent to our field exploration program, the lift station location was shifted about 25 feet to the south. To monitor groundwater conditions, we installed slotted standpipe piezometers in borings BH-1, BH-3, and BH-4. Field permeability tests (slug tests) were performed in the piezometers in order to estimate the permeability of the existing soils. We also installed pore pressure transducers in each monitoring well to record ground water fluctuations over a 2-week period to evaluate tidal influence on ground water. Field exploration methods are described in more detail, and summary boring logs, slug test, and tidal study results are presented in Appendix A. 2.2 LABORATORY TESTING Laboratory tests were conducted on selected samples obtained from the explorations to characterize engineering and index properties of the project soils. Laboratory tests included determination of in -situ moisture content, grain size distribution and Atterberg Limits (plasticity characteristics). The tests were conducted in general accordance with appropriate American Society of Testing and Materials (ASTM) standards, and are discussed in further detail in Appendix B. The results are presented in Appendix B, or are displayed on the exploration logs in Appendix A. 3. SITE CONDITIONS 3.1 SURFACE CONDITIONS The ground surface along the proposed new sewer alignment on W. Dayton Street is relatively flat, at approximate Elevation 13 feet. The datum used for this project is Mean Lower Low Water (MLLW) (Bob Custer, Inca Engineers, email correspondence, 2005). The two-lane (to three -lane) asphalt -paved roadway is approximately 43. (to 51) feet wide (curb -to -curb) with sidewalks on both sides. In addition to the existing sanitary sewer 2004069 Final Report.doc 2 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 lines which will be replaced, there are significant underground utilities in the project area, including water, power, telephone, gas, and storm sewer. West Dayton St. has a moderate traffic volume as it is the principal arterial for the Edmonds Marina and businesses to the southwest. Community Transit buses travel eastbound at regular intervals. 3.2 GENERAL GEOLOGIC CONDITIONS The geologic map for the project area (Minard, 1983) indicates the near -surface soils in the project area to consist of modified land. The waterfront was modified by placement of fill when the area was developed. Marsh Deposits, consisting of peat and organic silt, are mapped to the south of the project area. Glacial deposits are anticipated to underlie the site area at depth. Glacially consolidated sand, locally referred to as the Whidbey Formation, is mapped in upland areas to the east of the site. 3.3 SITE SOIL CONDITIONS 3.3.1 New Sewer Alignment (West Dayton Street) Below the pavement, borings BH-1 through BH-3 along West Dayton Street encountered a sequence of fill, marsh deposits, and glacial drift. The fill varied from 5 to 8'/z feet thick and consisted of silty fine to medium sand with variable gravel content. Standard Penetration Test (SPT) blow counts indicated the fill to be medium dense to dense, suggesting the fill was well -compacted. The gradation of the fill suggests it was derived as a cut in glacial till. Below the fill, we encountered marsh deposits, consisting of very soft to soft peat, very soft to stiff organic silt/silty clay, and very loose, very silty, fine sand. Boring BH-1 was terminated in the marsh deposits 16.5 feet below ground surface (BGS), and BH-2 and BH-3 penetrated the bottom of the marsh deposits at 13 and 10 feet BGS, respectively. Below the marsh deposits in BH-2 and in BH-3 we encountered medium dense . (weathered) to very dense sand with variable silt and gravel content, which is inferred to be glacial drift. A geologic profile along the centerline of West Dayton Street is presented in Figure 4. Note the vertical exaggeration (IOx) on this figure. 3.3.2 New Lift Station Location Soil conditions encountered in our BH-4 (east of the proposed lift station location) were similar to those described in the log of B-4 by CDM (west of the lift station). We 2004069 Final Report.doc 3 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 encountered a sequence of fill, marsh deposits, and dense glacial drift, as described below. Fill was encountered below the pavement and extending about 5 feet BGS. The fill was loose and consisted of silty sand with fine gravel, organics, and some glass shards. Below the fill, we encountered a 3'/2-foot thick layer of soft to very soft peat (marsh deposits). The moisture content of the peat sample was found to be 244 percent. Below the peat, we encountered glacial drift, consisting of medium dense (weathered) to dense, medium to coarse sand with variable silt and gravel content. From 25 feet BGS to the bottom of the boring, very dense, very silty sand with gravel was encountered. This material has a diamicton (till -like) consistency and appearance, and difficult drilling conditions were reported by the drilling subcontractor. We classified this soil as till -like glacial drift in our boring log. Our interpretation of subsurface conditions in the proposed lift station vicinity is illustrated in Cross Section A -A', Figure 5. 3.4 GROUNDWATER CONDITIONS The ground water levels measured in our piezometers on March 28 and August 10, 2005, are summarized in Table 1 below. Table 1. Piezometer Readings Boring Designation Ground Surface Elevation (ft MLLW) Ground Water Elevation (feet above MLLW) March 28, 2005 August 10, 2005 BH-1 12.97 8.0 6.4 BH-3 13.35 8.0 7.5 BH-4 12.71 8.2 7.7 The ground water level is anticipated to vary with the season, local subsurface conditions, precipitation, and other factors. However, transducer monitoring suggests that ground water levels are not appreciably influenced by tidal fluctuations. The results of the tidal study are presented in Appendix A. 2004069 Final Report.doc 4 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 4. CONCLUSIONS AND RECOMMENDATIONS 4.1 GENERAL The following is a summary of our conclusions and recommendations based on the soil and ground water conditions encountered in our explorations. • Trench boxes, sheet piles, or other means of temporary shoring support will be required for the entire length of new gravity sewer line. Dewatering will be required for the majority of the gravity sewer lines. Sumps and pumps may be adequate in shallower sections along the eastern portions of the alignment. However, where the proposed sewer invert extends significantly below the ground water level, dewatering wells or wellpoints will be required. Dewatering should be confined to the immediate area of the trench to limit ground water drawdown on adjacent properties. Variable subgrade conditions exist along the proposed invertgrades of the gravity sewers. Where the sewers are underlain by compressible marsh deposits, special measures for pipe bedding and backfilling will be required. Detailed geotechnical recommendations for gravity sewer construction are presented in Section 4.2. Construction of the proposed gravity sewers on both the north and south sides of the street will result in significant pavement disruption. A complete pavement resurfacing should be contemplated. Temporary excavations for the lift station should be supported with a relatively water -tight shoring system, such as interlocking steel sheet piles. Internally - braced shoring is recommended. The contractor should be responsible to design and install the temporary shoring. • The lift station excavation will extend approximately 10 feet below ground water; therefore, construction dewatering will be required. Dewatering should be undertaken from the inside of the shoring system, to reduce the potential for settlement of the surrounding infrastructure. Driving interlocking sheet piling down to the till -like layer will tend to act as a seal and will substantially reduce ground water flows into the excavation. Temporary excavation support recommendations are presented in Section 4.3. Manhole structures founded below the ground water level should be designed to resist upward buoyancy. forces. 2004069 Final Report.doe 5 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 4.2 NEW GRAVITY SEWERS ON WEST DAYTON STREET 4.2.1 General The proposed sewer lines can be constructed utilizing conventional open -trench construction. Construction dewatering will be required for the majority of the alignment. Sumps and trash pumps are likely to be adequate to dewater the eastern portions of the trenches. However, for the central to western portions of the alignment, where the sewer inverts extend more than about three feet below the ground water level, a formal construction dewatering program will be required. The contractor should be responsible to design and operate the dewatering system. Our explorations indicate that the inverts of the proposed new 8-inch diameter gravity sewers will encounter mixed subgrade conditions, varying from dense fill at the east end, to existing soft marsh deposits, and finally to glacial outwash at the west end (see Figure 4). Where existing soft and/or organic rich marsh deposits are encountered at pipe subgrade, we recommend an 18-inch (minimum) sub -excavation and replacement with crushed rock. 4.2.2 Temporary Excavation Support Maintenance of safe working conditions, including temporaryexcavation stability, is the responsibility of the contractor. In accordance with Part N of Washington Administrative Code (WAC) 296-155, latest revisions, all temporary cuts in excess of 4 feet in height must be either sloped or shored prior to entry by personnel. The existing soils along W. Dayton St., when de -watered, generally classify as Type C soil, per WAC 296-155, and, if no trench box is used, should be sloped no steeper than 1 %H:IV. Flatter side slopes will be required where ground water seepage occurs. Dewatering will be required to lower the ground water table below the base of the excavation a sufficient depth to provide for a stable subgrade that is suitable for workmen to place pipe bedding and lay pipe. Lateral support for the trench walls should be provided by the contractor to prevent loss of ground and possible distress to nearby utilities. General recommendations for design and implementation of shoring and bracing systems are presented below. Hydraulic shoring is recommended over trench boxes (shields), to reduce and limit ground disturbance parallel to the trenches. • Shoring should be designed and constructed to support lateral loads exerted by the soil mass. In addition, any surcharge from construction equipment, construction materials, excavated soils, or vehicular traffic on adjacent roadways should be included in the shoring design. The contractor should be required to submit a 2004069 Final Report.doc 6 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 shoring/excavation plan for review prior to construction. The plan should contain specific measures for temporary support and protection of all existing utilities and structures. • Precautions should be taken during removal of the shoring to minimize disturbance of the pipe, underlying bedding materials, and native subgrade soils. • The ground water level must be drawn down below the base of the excavation. The contractor should be responsible for control of ground and surface water and should employ sloping, slope protection, ditching, sumps, dewatering, and other measures as necessary to prevent sloughing of soils. 4.2.3 Trench Bottom Preparation and Bedding If unsuitable soils are encountered at the pipe invert during excavation, they should be . over -excavated a minimum of 18 inches below the bottom of the pipe bedding material. Unsuitable soils include soft peat, silt or organic material (i.e: logs, stumps etc.). Over -excavated areas should be backfilled with I'/ -inch minus crushed rock meeting the gradation requirements for crushed surfacing, as described in Section 9-03.9(3) of the WSDOT Standard Specifications (WSDOT, 2004). To prevent migration of fine-grained organic materials into the crushed rock, a geotextile separator be placed along the bottom and sides of the sub -excavation. The separator should meet the requirements of Section 9-33, Table 3, of the 2004 Standard Specifications. Where the native soils are firm to stiff and do not require over -excavation, bedding material should be placed directly on undisturbed native soils. Trench bottoms should be free of debris and standing water. If subgrade soils are disturbed, the disturbed material should be removed and replaced with additional compacted bedding material. Pipe bedding material, placement, compaction, and shaping should be in accordance with the project specifications and the pipe manufacturer's recommendations. In general, the pipe bedding and manhole foundation base material should meet the gradation requirements of Section 9 03.12(3) Gravel Backfill for Pipe Zone Bedding, of the 2004 Standard Specifications. Materials not meeting this gradation requirement may be acceptable 'in some areas and should be evaluated on a case -by -case basis. Pipe bedding should provide a firm uniform cradle for support of the pipes. A minimum 6-inch thickness of bedding material beneath the pipe should be provided. Prior to installation of the pipe, the pipe bedding should be shaped to fit the lower part of the pipe exterior with reasonable closeness to provide uniform support along the pipe. Pipe bedding material should be used as pipe zone backfill and placed in layers and tamped 2004069 Final ReporLdoc 7 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 around the pipes to obtain complete contact. To protect the pipe, bedding material should extend at least 6 inches above the top of the pipe. A typical trench detail is shown on Figure 6. 4.2.4 Pipe Settlement and Buoyancy - The likely mechanisms for pipe settlement involve poor bearing support immediately below the pipe, consolidation of underlying compressible soils under loads greater than previously existing, and recompression of excavation subgrade heave. Bedding the pipe in accordance with the recommendations described above, including sub -excavating at least 18 inches of soft and/or organic soils from the trench base will help reduce the potential for differential settlement along the pipeline. Along most of the alignment, the pipe and backfill are considered comparable in weight to the soils displaced even if imported trench backfill is used above the pipe. Therefore, it is expected that little or no increase in net soil pressure will occur as a result of placement of the pipe and trench backfill. Thus, little or no consolidation settlement is expected. Heave occurs when the bottom of the excavation deforms elastically as overlying material is removed. This heave can be exacerbated if proper dewatering techniques are not employed. Recompression of heaved soils due to backfilling of the trench can cause pipe settlement. Due to the granular nature of the on -site soils and the relatively shallow depths of excavation required for the pipeline, significant heave/recompression is not anticipated in most areas, provided the area is adequately dewatered prior to excavating. The contractor should take adequate precautions to limit the disturbance to trench bottom materials during excavation and dewatering. Manholes may experience significant upward buoyancy forces when the ground water level is higher than the fluid level inside the structures. Such structures should be designed to resist this upward force and to prevent possible heave and cracking of their bases and connecting lines. The weight of the structure and friction along its sides will provide resistance to uplift forces, as illustrated on Figure 7. As is shown in the figure, we recommend the ground water level be assumed to be at the ground surface for long- term design. The uplift resistance can be increased by extending the base of the structure beyond the walls or by adding mass concrete to the bottom of the structure. We anticipate the weight of the backfill over the pipeline will be sufficient.to resist buoyant uplift of the line itself. Aspects related to settlement of the backfill above the pipe are discussed in the following section. 2004069 Final Report.doc 8 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 4.2.5 Backfill Material and Compaction Portions of the excavated on -site material may be re -used as trench backfill. Organic -rich materials are unsuitable for trench backfill, and they should be exported from the site. The geotechnical engineer should evaluate the use of on site material on a case -by -case basis during construction. For material stockpiled on -site for re -use as trench backfill, we recommend performing a series of laboratory tests to quantify the soil properties. These tests should include grain -size analysis, moisture content and Modified Proctor moisture - density determinations. Based on the results of these tests, the contractor should moisture condition the stockpiles to within 3 percent of the optimum moisture content for compaction. During temporary storage, the soil should be protected from becoming saturated by appropriate use of plastic sheeting during wet weather conditions, or to prevent excessive drying during hot and dry conditions. Imported trench backfill material should consist of Bank Run Gravel for Trench Backfill, as specified in Section 9-03.19 of the Standard Specifications. Trench backfill that is more than 3 feet below roadways should be compacted in a systematic manner to at least 92 percent of the maximum dry density (MDD), as determined by ASTM test method D 1557. The upper 3 feet of trench backfill should be compacted to, at least 95 percent of MDD. In landscaped areas backfill should be compacted to at least 90 percent of MDD, except the top 2 feet which should be compacted to at least 92 percent. During placement of the initial lifts, the trench backfill material should not be bulldozed into the trench or dropped directly on the pipe. Furthermore, heavy vibratory equipment should not be permitted to operate directly over the pipe until a minimum of 3 feet of backfill has been placed over the pipe bedding. A significant cause of large settlement results from inadequate shoring practices and poor compaction during shoring removal and backfilling. Special care must be taken to obtain good compaction up to the edges of the excavation as the shoring is removed. Moreover, attention must be paid to achieve good compaction around manholes. 4.2.6 Construction D.ewatering Construction dewatering will be necessary to facilitate open trench pipeline construction. Dewatering should be accomplished in advance of construction, as necessary, so that excavation and placement of the pipe, pipe bedding and backfill materials is completed in relatively dry conditions. The dewatering program should be stopped and water levels returned to the pre -construction levels, prior to final surface grading. 2004069 Final Report.doc 9 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 Extended dewatering with deep wells, resulting in water lowering over a large area, is likely to cause ground settlement over a relatively large area. The magnitude of the settlement and its areal extent would depend on the amount of change in the water level, the length of time the water level was lowered, and the compressibility and thickness of the underlying soils. To limit potential dewatering-induced settlement to the area immediately adjacent to the trenches, we recommend a well point dewatering system be utilized. Well points, or eductor wells, consist of a series of closely spaced, small diameter, screened pipes that are driven or drilled in place, and connected to a manifold which in turn is connected to large vacuum pump operating on the ground surface. A properly designed, installed, and operated wellpoint system can draw down the ground water level within the work area, without causing a large drawdown cone, as occurs with deep dewatering wells. We recommend the contractor retain an experienced wellpoint specialist to install and operate the dewatering system. The results of slug testing on piezometers in boreholes indicate that the glacial drift sands at the lift station site and at BH-3 along the alignment have an average permeability of about 10-3 cm/sec. The peat and organic silt (marsh deposits) at BH-1 have an average permeability of about 10-5 cm/sec. We recommend the contractor be required to submit a dewatering plan for review by HWA to evaluate other potential impacts. We recommend the plans and specifications include provisions requiring contractors to maintain a minimum and maximum draw - down from dewatering. The contractor could utilize existing monitoring wells to aid in the determination of the effectiveness of the dewatering system. However, design and implementation of any dewatering system remains the responsibility of the contractor. 4.3 NEW LIFT STATION NORTH OF WEST DAYTON STREET 4.3.1 Temporary Shoring We understand the new lift station will require an approximately 15-foot deep temporary excavation. The excavation will extend about 10 feet below the existing ground water level. We recommend a relatively water -tight shoring system, such as interlocking steel sheet piles, be used. The principal advantage of steel sheet piles over soldier piles and wood lagging is that construction dewatering may be accomplished from within the shoring, without significantly lowering the ground water outside the shoring. The high permeability of soldier pile and lagging shoring would require construction dewatering on the outside of the excavation. Because of the proximity of the new lift station structure to the private 2004069 Final Report.doc 10 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 property to the east and the existing paved parking lot, dewatering induced settlement of the surrounding infrastructure should be avoided. Recommended design earth pressures for temporary braced shoring are presented in Figure 7. The contractor should be responsible for the temporary shoring system design. Successful installation and removal of the temporary shoring system is the responsibility of the contractor. It may be somewhat difficult to drive the sheet piles through the existing dense glacial drift underlying the lift station site. We recommend sheet piling with a minimum web thickness of %-inch be used. Sheet piling sections with a web thickness of 3/8-inch or less are prone to installation damage when driving through dense sand and gravel. A large vibratory hammer should be used to install the steel sheets, to ensure the required penetration is achieved. The sheet piling maybe extracted or cut below ground surface and left in place when the lift station construction is completed and backfilled. Driving sheet piles into the dense sand and gravel could induce substantial ground vibrations. _ Excessive or sustained levels of vibration could potentially damage nearby structures and improvements. To reduce this risk, the contractor should be required to limit construction -induced ground vibrations adjacent to the work area, to a maximum peak particle velocity of 2.0 inches per second. The site area should be instrumented using geophones to monitor vibration. levels during all pile driving. If vibrations exceeding 2.0 inches per second are measured, the contractor should be required to stop work and propose a method of proceeding at a lower vibration level. One potentially acceptable method would be pre -drilling to loosen the glacial soils before driving the sheet piles. 4.3.2 Ground Water Control / Dewatering Construction dewatering should be accomplished from within the relatively water -tight shoring system, to limit drawdown exterior to the shoring. Till -like material, consisting of very dense silty sand with gravel, exists below 25 feet. This material has a much lower permeability that the overlying clean sand and gravel. Driving sheet piles into the till -like material will cut off ground water and substantially reduce flows into the excavation. One method of controlling ground water would be to drive the steel sheets. down and into the till -like layer, excavate in the wet to subgrade elevation, and then tremie-pour a concrete slab ("mud -slab"). Once the concrete has cured, the water above the mud slab could be pumped out of the excavation. The mud slab would need to be sufficiently thick (of the order of 4 feet) to resist the upward hydraulic gradient due to the ground water on 2004069 Final Report.doc I I HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 the outside the excavation. Leakage through joints in the steel sheets and along the mud slab/sheet pile interface could be handled using. sumps and trash pumps. Alternatively, dewatering wells could be installed on the inside of the shoring. The effectiveness of the dewatering wells will depend on whether the sheet piles are keyed into the till -like layer. The contractor should retain a dewatering specialist to design and. operate the dewatering system. Slug testing in the piezometer at our boring BH-4 indicated the relatively clean gravelly sand between 15 and 25 feet below the ground surface to have an average permeability of about 10-3 cm/sec. 4.3.3 Lift Station Excavation Excavations for the lift station can be completed with conventional excavating equipment, such as trackhoes. Although not encountered in our borings, there is a potential for logs to exist within the marsh deposits, and boulders may exist within the glacial drift. The contract should contain provisions for dealing with oversize materials. 4.3.4 Buoyancy As with other manhole structures, the lift station will need to be designed to resist hydraulic buoyancy. Recommended parameters for calculating uplift resistance are presented in Figure 6. We recommend the ground water be assumed to be at the ground surface for buoyancy resistance calculations. 4.4. SEISNIIC CONSIDERATIONS 4.4:1 Liquefaction Susceptibility Loose cohesionless soils below ground water are susceptible to liquefaction in response to an earthquake. Our analyses indicate a design level earthquake could cause limited liquefaction in discrete zones of loose sand below the sewer lines and manhole structures. This could cause localized minor settlement of the affected structures. Our analyses indicate the dense sand present below the proposed lift station structure is not susceptible to liquefaction during a design level earthquake. 4.4.2 Code -Based Design Parameters Whereas, we are not aware of code -based design requirements that apply to sewer conveyance lines and appurtenant manhole structures, seismic coefficients for use with 2004069 Final Report.doc 12 HWA GEOSciENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 the General Procedure described in Section 1615 of the 2003 International Building Code are presented in this section. The seismic ground motion procedure contained in the 2003 IBC is based upon a Maximum Considered Earthquake (MCE) with a 2 percent probability of exceedance in 50 years (i.e. recurrence interval of approximately 2500 years). Ground motions for the MCE in the IBC 2003 are linked to probabilistic earthquake hazard mapping efforts that have been conducted by the United States Geological Survey (Frankel, et al., 1996, 2002). Very dense sand was encountered within 20 feet of the ground surface in our borings. Furthermore, the thickness of highly organic soils was less than 10 feet in our borings. Therefore, the site classifies as Site Class C, as described in Section 1615.1 of the 2003 IBC. For the site location, the design maximum considered spectral response I cceleration at short periods, SS, is 1.21 g. The design maximum considered spectral response acceleration 1 second period, S 1, is 0.42g. Procedures for determination of the response spectra recommended for design is provided in Section 1615.1.4 of the Code. 4.5 WET WEATHER EARTHWORK General recommendations relative to earthwork performed in wet weather or in wet. conditions are presented below. These recommendations should be incorporated into the contract specifications. • Earthwork should be performed in small areas to minimize exposure to wet weather. Excavation or the removal of unsuitable soil should be followed promptly by the placement and compaction of clean structural fill. The size and type of construction equipment used may need to be limited to prevent soil disturbance. • The ground surface within the construction area should be graded to promote run-off of surface water and to prevent the ponding of water. • The ground surface within the construction area should be sealed by a smooth drum roller, or equivalent, and under no circumstances should soil be left uncompacted and exposed to moisture infiltration. • Excavation and placement of fill material should be undertaken under the observation of a representative of the geotechnical engineer, to determine that the work is being accomplished in accordance with the project specifications and the recommendations contained herein. 2004069 Final RTort.doc 13 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 4.6 DRAINAGE AND EROSION CONSIDERATIONS The native soils are easily erodable when exposed and subjected to surface water flow. Surface water runoff can be controlled during construction by careful grading practices. Typically, these include the construction of shallow earthen berms and the use of temporary sumps to collect runoff and prevent water from damaging exposed subgrades. All collected water should be directed under control to a suitable discharge system. Erosion can also be limited through the judicious use of silt fences and straw bales. The contractor should be responsible for control of ground and surface water and should employ sloping, slope protection, ditching, sumps, dewatering, and other measures as necessary to prevent erosion of soils. In this regard, grading, ditching, sumps, dewatering, and other measures should be employed as necessary to .permit proper completion of the work. 4. CONDITIONS AND LIMITATIONS We have prepared this report for the City of Edmonds and HDR for use in design of a portion of this project. This report should be provided in its entirety to prospective contractors for bidding and estimating purposes; however, the conclusions and interpretations presented in this report should not be construed as a warranty of existing subsurface conditions. Experience has shown that soil and ground water conditions can vary significantly over small distances. Inconsistent conditions can occur between exploration locations and may not be detected by a geotechnical study of this nature. If, during future site operations, subsurface conditions are encountered which vary appreciably from those described herein, HWA should be notified for review of the recommendations of this report, and revision of such if necessary. . Sufficient geotechnical monitoring, testing, and consultation should be provided during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should conditions revealed during construction differ from those anticipated, and to verify that geotechnical aspects of construction comply with the contract plans and specifications. Within the limitations of scope, schedule and budget, HWA attempted to execute these services in accordance with generally accepted professional principles_ and practices in the fields of geotechnical engineering and engineering geology in the area at the time the report was prepared. No warranty, express or implied, is made. The scope of our work did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous substances in the soil, surface water, or ground water at this site. 2004069 Final Report.doc 14 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 This firm does not practice or consult in the field of safety engineering. We do not direct the contractor's operations, and we cannot be responsible for the safety of personnel other than our own on the site. As such, the safety of others is the responsibility of the contractor. The contractor should notify the owner if he/she considers any of the recommended actions presented herein unsafe. 0, We appreciate the opportunity to provide geotechnical services on this project. Should you have any questions or comments, or if we may be of further service, please do not hesitate to call. Sincerely, HWA GEOSCIENCES INC. 0. CO �o �,4°cte�`�� F��ONAL tG EXPIRES 08 / 18 Erik O. Andersen, P.E. L.A. "Lorne" Balanko, P.E. Senior Geotechnical Engineer Vice President 2004069 Final Report.doc 15 HWA GEOSCIENCES INC. January 11, 2006 HWA Project No. 2004-069-21-1200 5. REFERENCES Bouwer, H., 1989, The Bouwer and Rice Slug Test — An Update, Ground Water, vol. 27, No. 3, May -June, pp. 304-309. Bouwer, H., and Rice, R.C., 1976, A Slug Test for Determining Hydraulic Conductivity of Unconfined Aquifers with Completely or Partially Penetrating Wells, Water Resources Research, vol. 12, No. 3, pp. 423428. CDM, 2004, Geotechnical Engineering Study, Sound Transit Commuter Rail System, Edmonds Transit'Station, draft report dated May 27, 2004. Boring Logs were provided to the City of Edmonds by Sound Transit. Frankel, et al.,2002, Documentation for the 2002 Update of the National Seismic Hazard Maps, USGS Open File Report, 02-420. HDR Engineering, Inc., 2004, Lift Stations 7 & 8 Integration & Rehabilitation, Predesign Report, November, 2004. International Code Council (ICC), 2002, 2003 International Building Code. Minard, J.P., 1983, Geologic Map of the Edmonds East and Edmonds West Quadrangles, Washington, MF 1541. Washington Department of Transportation (WSDOT), 2004, Standard Specifications for Road, Bridge, and Municipal Construction, M 41-10. 2004069 Final Report.doc 16 HWA GEOSCIENCES INC. i 104 �! R-ClU �'tigo cC II I< 524:frI <�? C �o ��/.�/r�VICINITY MAP HM CU,NfY\C LIFT STATIONS 7 & 8 EDMONDS, WASHINGTON I-IMPROJECTS12004 PROJECTS12004-069-21 EDMONDS LIFT STATIONS 7 & 8 REPLACEMENTXDWGILS 7AND8.DWG f t NOT TO SCALE WN BY Ili CKEO BY EA E PROJECT NO. 5.09.05 2004-069 I Q �F r• 4 S S S MH 1 - LS7 (EXIS, 2+50 WET WELL-,IE 0.70 LEGEND H-1 HWA BOREHOLE DESIGNATION AND APPROXIMATE LOCATION (CURRENT STUDY) CDM BOREHOLE DESIGNATION AND APPROXIMATE LOCATION (MAY 27, 2004) A A' CROSS SECTION DESIGNATION AND LOCATION 2- )JECT NO. 2004-069 BASE MAP PROVIDED BY: HDR ENGINEERING INC, JANUARY 2006 H:11 PROJECTS12004 PROJECTS12004-069-21 EDMONDS LIFT STAI i i { 10 f� I € Lu a i LL Lu " Lu = 9 j � S S W00 B0 7400 Q f MH 2� I i LEGEND H fiWA BOREHOLE DESIGNATION AND APPROXIMATE SITE AND �" BY EEK FlQW NO. 3 aw=m ey E& LOCATION EXPLORATION)ATE PROJECT NO. PLAN 01.09.06 2004-069 BASE MAP PROVIDED BY: HDR ENGINEERING INC. JANUARY 2006 H:\1PROJECTS12004 PROJECTS12004-069-21 EDMONDS LIFT STATIONS 7 & 8 REPLACE! REV 00 EFK 01/09/06 WEST EAST 15 I 15 13 m 14 13 1 2 12 25 \� \\/ \�\ �\ 11 37 B �r// // 2 \/��/�� \\% \� 41 \ 9 3 7 / // dli SIDE \ \ 8 `•, 7 Z 5Jp� p \\\ s Z 4 np .fin O O 4 a / // / 3 // 3 W 2 W d'g0� r/iri////////- 1 0 64//r / 2 0 2 . p� p`' t 0 °y'/ // �/ // // /r // , 0 -1 45 27 / -2 t-5 0+00 0 5+00 5+50 6+00 LEGEND M m BOREHOLE DESIGNATION OFILES PROVIDED BY HDR ENGINEERING INC. CONTACTS SHOWN ARE BASED ON INTERPOLATION 4CED BORINGS AND SHOULD BE CONSIDERED STANDARD PENETRATION TEST 2 N-VALUE v WATER LEVEL MEASURED IN = PIEZOMETER PIEZOMETER SCREENED 64 INTERVAL i 7 INFERRED GEOLOGIC CONTACT GEOLOGIC PROFILE DRAWN 6 45 ALONG CENTERLINE NECKED BOTTOM OF BORING W. DAYTON ST. re 51 2004-069 BASE MAP PROVIDED BY: HDR ENGINEERING INC, JANUARY 2006 LEGEND x m 2 Z 2 17 A (WEST) IT is °° T A' _ (EAST) m � ...._........T15 10 5 0 2; 8 J 21 17 LLI LL ILL 0 25 :4} Z30 Q 67 w -5 81 59 57 91 -10 , -15 ........:..... 50/5":- BOREHOLE DESIGNATION STANDARD PENETRATION TEST N-VALUE P WATER LEVEL MEASURED IN PIEZOMETER PIEZOMETER SCREENED INTERVAL 50/9 ..; INFERRED GEOLOGIC CONTACT BOTTOM OF BORING BASE MAP PROVIDED BY: HDR ENGINEERING INC, JANUARY 2006 CROSS SECTION A -A' (PROPOSED LIFT STATION) 10 E C -5 -10 -15 -20 C PATM " 5 �� ►h No= Nm 01.09.06 2004-069 LEGEND H-1 HWA BOREHOLE DESIGNATION AND APPROXIMATE LOCATION (CURRENT STUDY) B-4 CDM BOREHOLE DESIGNATION AND APPROXIMATE TTT LOCATION (MAY 27, 2004) A A' CROSS SECTION DESIGNATION AND LOCATION BASE MAP PROVIDED BY: HDR ENGINEERING INC, JANUARY 2006 H:11 PROJECTS12004 PROJECTS0004-069-21 EDMONDS LIFT STATIONS 7 8 8 REPLA( I 0' 10' 20' 30' 60' SCALE: 1 "=30' HMGEOSCIENCES INC LIFT STATIONS 7 & 8 EDMONDS, WASHINGTON JUL - 8 2000 2 )JECT NO. 2004-069 V 00 FFK 01/09/06 I �VR ui fy_ D LL Lu LLJ Ln %-.11 -S LEGEND s � BH-2 3+5 MH 2 V) V) (n 7-1 S-S S-S -s'-s -S S-S s BH-1 00 m 4+50 5+00 5+'5 6+00 6+50. DAY FON STREET MH-13 s We, 1. BH-1 HWA BOREHOLE DESIGNATION AND APPROXIMATE + LOCATION 0' 10' 20' 30' 60' SCALE: 1 "=30' 111 061 to 7+00 j C-7) u u , P( q r -, _- -" j I I ) L JUL 8 2008 01 BASE MAP PROVIDED BY: HOR ENGINEERING INC, JANUARY 2DO6 2004-069 WEST I c _ _ EXISTING GROUND SURFACE 15 _. ....... .. .. .......... • � 'ALONG THE'CENTERLINE OF . .N 2 14 m ; WEST DAYTON Sr. m / \ V, \ FI LL 10 - \ / \\ \ \\ PROPOSED 8" _7/ i \\ w 6 / / ILLw �� /// /ff//f MARSH %f// f/% 0 Z s Q Q°o o��' r. �'. '� . DEPOSITS Q 3 �O o °cam 13PROPOSED 8 SAN IV Luz �00� OoQpOLu �p 1 � c>4 -• � o 0 0 p o�`��'' Qn /� / a o 0 o©�Qp,�gQ° Oo p opV" �Qrrj� 0°0�Z 45 o GLACIAL c �C�" (� 000 00 0 �po0 ct po Qp� O�OoOo� Q�V" 31 O Qo�oC -3IX p Oo o Q �� 0 OoDoC DRIFT_ )o0n00 o c4 0° 00 opQ�O �Op Oo 0 o(T�p�V"n0 Oo�oO 0 o Op ��� Oo o °Givp -.�nV�(�ns2(l�no0op��V*�,�52(19on� �p_��i0n�0onn�o�nO�U"��QO�,Q000�-.p..l A...... .�. .�. . . . . . . . . . . . . . . . .�. .�. . . . . . ! . ./. ..(. ? ./. . . . . .�. . 0+00 0+50 1+00 1+50 2+00 2+50 3+00 3+50 4+00 LEGEND (M m BOREHOLE DESIGNATION STANDARD PENETRATION TEST 2 N-VALUE v WATER LEVEL MEASURED IN = PIEZOMETER PIEZOMETER SCREENED 6471 INTERVAL ? INFERRED GEOLOGIC CONTACT 45 BOTTOM OF BORING HORIZONTAL SCALE: 1 "=50' O' 25' 50' 100' 0' 2.5' 5' 10' VERTICAL SCALE: 1 "=5' (1OX VERTICAL EXAGGERATION) �I I HWAGEOSCIENCES INC 4+50 5+00 5+50 ST 1 15 �14 13 12 11 10 9 8 7 6 LL s z 0 4 Q 3 2 w 1 0 -1 -2 -3 -5 6+00 NOTES 1. PROPOSED SEWER PROFILES PROVIDED BY HDR ENGINEERING INC. 2. INFERRED GEOLOGIC CONTACTS SHOWN ARE BASED ON INTERPOLATION BETWEEN WIDELY SPACED BORINGS AND SHOULD BE CONSIDERED. APPROXIMATE. JUL - 8 2000 4 )IECT NO. 2004-069 BASE MAP PROVIDED BY: HDR ENGINEERING INC, JANUARY 2006 H:IIPROJECTS\2004 PROJECTS12004-069-21 EDMONDS LIFT STAI ek A (WEST) 15 ( . . . . . . . .. . . ^' '� (EAST) cc). . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . .. . . . . . . . .. .. . . EXISTING GROUND. . . ... . . . . . . . .. .. . . . . . . . . . .. . . . . . . . m . . . .. . . 1 �• SURFACE ' 1(' 15 U 10 :\; .\. �. �2;' ; "' FILL . .... .........:. .........:.........:. ;`;;, �•: �` FILL10 F.' ;\'., . ,� \ '�/ �` / '\ /; '�`.�\ \ ^ ^/` 1•/ \ ` PROPOSED yp \\'\ \ice �� f•, /�/� ,'\ _ \ �` C _\\ x �? — ? — LIFfi L STATION EXCAVATION MARSH MARSH 5 o DEPOSITS ...... :......... :......... :................... :. DEPOSITS 2. 5 21 17 lWi 0 25 ............:.......... :43 0 . Z O ;. I-- Q 3067 ,. W -5 e1 > - ' \ GLACIAL 58 -5 DRIFT _ 57 \ 91 - -10 -15 ........ :......... :......... :......... :................... :................................................. -15 LEGEND 2 co BOREHOLE DESIGNATION 2 STANDARD PENETRATION TEST 2 N-VALUE Z WATER LEVEL MEASURED IN - PIEZOMETER PIEZOMETER SCREENED 2 INTERVAL �- INFERRED GEOLOGIC CONTACT 17 BOTTOM OF BORING BASE MAP PROVIDED BY: HDR ENGINEERING INC. JANUARY 2006 TILL -LIKE NOTE GLACIAL ��� 1. INFERRED GEOLOGIC CONTACTS SHOWN ARE BASED ON INTERPOLATION DRIFT BETWEEN WIDELY SPACED BORINGS AND SHOULD BE CONSIDERED APPROXIMATE IV . 2. TEMPORARY LIFT STATION EXCAVATION LOCATION AND SIZE MAY VARY FROM THAT SHOWN. HORIZONTAL SCALE: 1 "=5' 0' 2.5' 5' 10' 0' 2.5' 5' 10' VERTICAL SCALE 1 "=5' Z I 3 .,L JUL - 8 2000 CROSS SECTION LIFT STATIONS 7 & 8 A -A' J EDMONDS, WASHINGTON (PROPOSED LIFT An P20im Nm STATION) 01.09.06 2004-069 TRENCH EDGES MUST BE SAW CUT AND TACKED PRIOR TO FINAL TRENCH PATCH HMA CRUSHED _ SURFACING 3' BACKFILL WITHIN 3' OF SURFACE. COMPACTED TO 95% OF MAX DENSITY BACKFILL MORE THAN 3' BELOW SURFACE. COMPACTED TO 92% OF MAX DENSITY PIPE ZONE BEDDING PER SECTION 9-03-12(3) OF WSDOT STANDARD SPECIFICATIONS 18" MINIMUM OVER -EXCAVATION AND REPLACEMENT WHERE SOFT, ORGANIC -RICH, OR OTHERWISE UNSUITABLE SOILS ARE ENCOUNTERED PAVEMENT SECTION PER CITY OF EDMONDS STANDARD DETAILS OR MATCH EXISTING BACKFILL MATERIAL: SUITABLE ON -SITE MATERIAL OR IMPORTED BANK RUN GRAVEL, PER SECTION 9-03.19 OF WSDOT STANDARD SPECIFICATIONS 6" MIN 6" MIN GEOTEXTILE SEPARATOR, PER SECTION 9-33.2, TABLE 3, WSDOT STANDARD SPECIFICATIONS 1 Y4" MINUS CRUSHED ROCK, PER SECTION 9-03.9(3) OF WSDOT STANDARD SPECIFICATIONS TYPICAL TRENCH SECTIONs'�� '� CITY OF EDMONDS a«Eu � � M act, f MC&0SCIENaS INC LIFT STATION 7 & 8 REPLACEMENT DATE PROJECT NO. EDMONDS, WASHINGTON 01.09.06 2004-069-21 H:\1PROJECTS0004X PROJECTS\2004-069-21 EDMONDS LIFT STATION 7 & 8 REPLACEMENT\DWGWEW CAD 0908051E4-3 TYP TRNCH_SEC_FOUND_STAB.DWG PROPOSED STRUCTURE DESIGN GROUNDWATER LEVEL 1 Fsw H 1 4: PASSIVE SOIL WE * Buoyant force could result in high bending moments in slab SYMBOL ASSUMPTIONS B = Width of extended base in feet Soil Unit Weight = 130 pcf Soil Friction Angle = 30' W = Structure weight in kips At —rest Pressure Coefficient = 0.50 W e = Total soil weight above base in kips Active Pressure Coefficient = 0.33 Buoyant Soil Unit Weight = 68 pcf F8 =Buoyant force in kips = Unit weight of water x volume of NOTES structure below design ground —water level Factor of Safety = W+Fs,wr L L = Perimeter around base of wall in feet Fe (without extended base, Fss = Shearing resistance of soil as indicated on the left side) = 0.006H 2 (in kips per foot of wall) Factor of Safety = W + W8 + F� L Fsw = Shearing resistance of soil —wall Fe = contact 0.004H 2 with extended base a (in kips per foot of wall) round perimeter of structure, as indicated on the right side of this figure) PARAMETERS FOR CALCULATING �' HMGEOSCU143SM UPLIFT RESISTANCE LIFT STATIONS 7 & 8 EDMONDS, WASHINGTON H:IIPROJECTS\2004 PROJECTS12004-069-21 EDMONDS LIFT STATIONS 7 8 8 REPLACEMENWWGILS 7AND8.DWG 01.09.06 I 2004-069 REV 00 KLS �sroe I--- B - X . SURCHAGE LOAD =. q 7-1 SURCHARGE PRESSURE s' DESIGN GROUND WATER LEVEL I� u .62.4(H-5) HYDRO STATIC PRESSURE 33H BRACED SHEET PILE WALL 9. 17H BOTTOM OF EXCAVATION 11.5H DESIGN .WATER LEVEL INSIDE . EXCAVATION 69 + 18H 69 + 18(H+D) ii 265D I ACTIVE PRESSURE PASSIVE PRESSURE Influence Factor,( i ) for Surcharge Loads For: x>_H 0=0 H>x>H/2 i=0.5 H/2>x>H/4 i=0.75 NOTES: H/4>x i=1.0 1. ASSUMED SOIL CONDITIONS: 0-9 FT: 0 = 251, yt = 125PCF, yb = 63PCF, Ka = 0.42 9 FT TO BOTTOM OF SHORING: 0 = 361, 7t = 130PCF, yb = 68PCF, Ka = 0.26, Kp = 3.9 GROUND WATER OUTSIDE SHORING IS 5 FT BELOW GROUND SURFACE GROUND WATER INSIDE SHORING IS AT THE BASE OF THE EXCAVATION 2. SURCHARGE LOADS SHOULD BE ADDED WHERE APPROPRIATE, USING THE FORMULA ABOVE. 3. SHORING EMBEDMENT (D) SHOULD BE DETERMINED BY SUMMATION OF MOMENTS ABOUT THE LOWEST BRACE. 4. NO FACTOR OF SAFETY HAS BEEN APPLIED TO THE RECOMMENDED PASSIVE EARTH PRESSURE. 5. AN ALLOWABLE BEARING CAPACITY OF 5,000 PSF MAY BE ASSUMED FOR SPREAD FOOTING FOUNDATION DESIGN, AT DEPTHS > H=10 FT. H D DESIGN EARTH PRESSURES FOR ou" G►R TEMPORARY BRACED SHORING aEa® °1 -EA-8 A. oAR raoJEcr Mo. LIFT STATIONS 7 & 8 01.09.06 2004-069 EDMONDS, WASHINGTON H:11 PROJECTS\2004 PROJECTS\2004-069-21 EDMONDS LIFT STATIONS 7 & 8 REPLACEMENT\DWGILS 7AND8.DWG REV 00 EFK 01109= APPENDIX A FIELD EXPLORATION APPENDIX A FIELD EXPLORATION The field exploration program consisted of four borings along the proposed alignment, designated BH-I through BH-4. The borings were drilled on March 2 and 3, 2005, by Holocene Drilling, Inc. of Fife, Washington using a Mobile B-61 truck -mounted drill rig. Borings BH-1 through BH-3, along W. Dayton St., were each drilled to depths of 16'/z feet below the ground surface. Boring BH-4, near the proposed lift station, was drilled to a depth of 40 feet below the ground surface. The boring locations were surveyed by INCA after completion of the drilling. The boring locations are shown on the Site and Exploration Plan, Figures 2 and 3. At selected intervals within each drilled boring, Standard Penetration Test (SPT) sampling was performed using a 2-inch outside diameter. split -spoon sampler and a 140-pound automatic hammer. During the test, a sample is obtained by driving the sampler 18 inches into the soil with the hammer free -falling 30 inches. The number of blows required for each 6-inches of penetration is recorded. If a total of 50 blows is recorded within a single 6-inch interval, the test is terminated, and the blow count is recorded as 50 blows for the number of inches of penetration. This resistance, or N-value, provides an indication of the relative density or granular soils and the relative consistency of cohesive soils. At the completion of BH-1, BH-3, and BH-4, 2-inch monitoring wells were installed. The monitoring wells were finished with a flush -mounted surface monument. Well completion details are indicated on the individual boring logs. Ground water levels in the piezometers were measured on March 28, 2005, and the readings are indicated on the boring logs. Boring BH-2 was abandoned with bentonite chips on termination of drilling. Each of the explorations was completed under the full-time observation of an HWA geologist. Representative soil samples obtained from the explorations were placed in plastic bags and taken to our Lynnwood, Washington, laboratory for further examination and testing. HWA personnel recorded pertinent information including soil sample depths, stratigraphy, soil engineering characteristics, and ground water occurrence as the explorations were excavated. Soils were classified in general accordance with the classification system described in Figure A-1, which also provides a key to the exploration log symbols. The summary logs are presented on Figures A-2 through A-5 2004069 Final Report.doc A -I HWA GEOSCIENCES INC. The stratigraphic contacts shown on the individual logs represent the approximate boundaries between soil types. The actual transitions may be more gradual. Slug testing was performed in the piezometers to determine the permeability of the soil surrounding the screened portions of the piezometers. The slug tests were conducted in general accordance with the method outlined by Bouwer and Rice (1976), and updated by Bouwer (1989). The slug test results are presented in Figures A-6 through A-8. To investigate the potential tidal influence on ground water levels, we installed pore pressure transducers and data loggers in each of the piezometers. The transducers continuously recorded the ground water conditions between August 10 and August 25, 2005. The measured ground water elevation at each piezometer and published tide information for Edmonds are plotted on Figures A-9 through A711. 2004069 Final Report.doc A-2 HWA GEOSCIENCES INC. RELATIVE DENSITY OR CONSISTENCY VERSUS SPT N-VALUE COHESIONLESS SOILS COHESIVE SOILS Approximate Approximate Density N (blows/ft) Consistency N (blows/ft) Undrained Shear Relative Density(%) Strength (psf) Very Loose 0 to 4 . 0 - 15 Very Soft 0 to 2 <250 Loose 4 to 10 15 - 35 Soft 2 to 4 250 - 500 Medium Dense 10 to 30 35 - 65 Medium Stiff 4 to 8 500 - 1000 Dense 30 to 50 65 - 85 Stiff 8 to 15 1000 - .2000 Very Dense over 50 85 - 100 Very Stiff 15 to 30 2000 - 4000 Hard over 30 >4000 USCS SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP DESCRIPTIONS Gravel and GW Well -graded GRAVEL Coarse Clean Gravel • Grained Gravelly Soils (little or no fines) Q GP Poorly -graded GRAVEL Soils a More than 50 % of Coarse Gravel with u GM Silty GRAVEL Fraction Retained Fines (appreciable on No. 4 Sieve amount of fines) GC Clayey GRAVEL Sand and Clean Sand •• SW Well -graded SAND More than Sandy Soils (little or no fines) SP Poorly -graded SAND 50 % Retained 50 % or More on No. of Coarse Sand with SM Silty SAND 200 Sieve Fines (appreciable Fraction Passing Size No. 4 Sieve amount of fines) SC Clayey SAND ML SILT Fine Silt CL Lean CLAY Grained and Liquid Limit Soils Less than 50 % Gay _ - OL Organic SILT/Organic CLAY MH Elastic SILT Silt 50% or More Liquid Limit Passing and 50 % or More CH Fat CLAY No. 200 Sieve Gay Size OH Organic SILT/Organic CLAY Highly Organic Soils PT PEAT. COMPONENT DEFINITIONS COMPONENT SIZE RANGE Boulders Larger than 12 in Cobbles 3 in to 12 in Gravel 3 in to No 4 (4.5mm) Coarse gravel 3 in to 314 in Fine gravel 3/4 in to No 4 (4.5mm) Sand No. 4 (4.5 mm) to No. 200 (0.074 mm) Coarse sand No. 4 (4.5 mm) to No. 10 (2.0 mm) Medium sand No. 10 (2.0 mm) to No. 40 (0.42 mm) Fine sand No. 40 (0.42 mm) to No. 200 (0.074 mm) Silt and Gay Smaller than No. 200 (0.074mm) TEST SYMBOLS %F Percent Fines AL Atterberg Limits: PL = Plastic Limit ILL. = Liquid Limit CBR California Bearing Ratio CN Consolidation DD Dry Density (pcf) DS Direct Shear GS Grain Size Distribution K Permeability MD Moisture/Density Relationship (Proctor) MR Resilient Modulus PID Photoionization Device Reading PP Pocket Penetrometer Approx. Compressive Strength (tsf) SG Specific Gravity TC Triaxial Compression TV Torvane Approx. Shear Strength (tsf) UC Unconfined Compression SAMPLE TYPE SYMBOLS ® 2.0" OD Split Spoon (SPT) (140 lb. hammer with 30 in. drop) IShelby Tube 3-1/4" OD Split Spoon with Brass Rings OSmall Bag Sample Large Bag (Bulk) Sample aCore Run Non-standard Penetration Test (3.0" OD split spoon) GROUNDWATER SYMBOLS Q Groundwater Level (measured at time of drilling) 1 Groundwater Level (measured in well or open hole after water level stabilized) COMPONENT PROPORTIONS PROPORTION RANGE DESCRIPTIVE TERMS < 5% Clean 5 -12 % Slightly (Clayey, Silty, Sandy) 12 - 30% Clayey, Silty, Sandy, Gravelly 30 - 50 % Very (Clayey, Silty, Sandy, Gravelly) Components are arranged in order of increasing quantities. NOTES: Soil classifications presented on exploration logs are based on visual and laboratory observation. Soil descriptions are presented in the following general order. Density/consistency, color, modifier (if any) GROUP NAME,additions to group name (if any), moisture content. Proportion, gradation, and angularity of constituents, additional comments. (GEOLOGIC INTERPRETATION) Please refer to the discussion in the report text as well as the exploration logs for a more complete description of subsurface conditions. CITY OF EDMONDS LIFT STATION 7 REPLACEMENT HMGEOSCIENCES INC EDMONDS, WASHINGTON MOISTURE CONTENT DRY Absence of moisture, dusty, dry to the touch. MOIST Damp but no visible water. WET Visible free water, usually soil is below water table. LEGEND OF TERMS AND SYMBOLS USED ON EXPLORATION LOGS PROJECT NO.: 2004-069 FIGURE: A-1 LEGEND 2004069.GPJ 5/9/05 I 01 DRILLING COMPANY: Holocene Drilling SURFACE ELEVATION: 12.97 t feet DATE STARTED: 3/2/2005 DRILLING METHOD: Hollow Stem Auger DATE COMPLETED: 3/2/2005 SAMPLING METHOD: Standard Penetration Test LOGGED BY: G. Emens LOCATION: Refer to Figure 3 rn wm w z Standard Penetration Test U N of (140 lb. weight, 30" drop) } U v w Q A Blows per foot -� 0 w w N W w m >- rn 0— cn D DESCRIPTION Q cn Q co W 9 a. ; O w 0 a cn W 'R 0 0 10 20 30 40 50 0-1 r0 1 5- 1 10- 1 15- 1 20- 1 25 - SM 4 in. asphalt and crushed gravel base. Dense, medium to dark brown, silty, fine to medium SAND (SM) with trace gravel, moist to wet [FILL] PT Soft, reddish brown PEAT (PT), wet. c r [MARSH DEPOSITS] _— _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ OL Very soft to stiff, mottled greenish gray, ORGANIC SILT (OL), wet Bottom of boring at 16.5 ft. bgs. Standpipe piezometer installed (see schematic). Ground water level measured at Elevation 8 feet, March 28, 2005, approximately 3PM. 1 ,f 0-0-2 _ NOTE: This log of subsurface, conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. !ir;il • >41-10 1 ....:....1 —20 1 L 25 0 20 40 60 80 100 Water Content (%) Plastic Limit {--♦ Liquid Limit Natural Water Content BORING: BOA CITY OF EDMONDS BH-1 LIFT STATION 7 REPLACEMENT fMGEOSCIENCES INC EDMONDS, WASHINGTON PAGE: 1 of 1 PROJECT NO.: 2004-069 FIGURE: A-2 PZO 2004069.GPJ 5/6/05 DRILLING COMPANY: Holocene Drilling SURFACE ELEVATION: 13.09 t feet DATE STARTED: 3/2/2005 DRILLING METHOD: Hollow Stem Auger DATE COMPLETED: 3/2/2005 SAMPLING METHOD: Standard Penetration Test LOGGED BY: G. Emens LOCATION: Refer to Figure 3 5- 1 10- 1 15- 1 20 - 1 25 - w w UZ of a ED < m U ~ } D to U (n Q 1- Z Cn Z d d N w D 0 DESCRIPTION ran c¢n a. a O (D 0 SM 4 in. asphalt and crushed gravel base. Dense, gray to dark brown, silty, fine to medium SAND (SM) with rounded to sub -rounded gravel, moist to wet [FILL] No recovery for Sample 1. Sampler was possibly driving gravel. Seven inches of recovery for Sample 2. OL Very soft, mottled greenish gray, ORGANIC SILT (OL), with organic fragments, wet. _______jMARSHDEPOSITSl______J pT Very soft,AT reddish brown PE(PT), wet. Medium stiff, mottled light olive gray, sandy SILT, with fine sand trace fine gravel, and trace or ganics,wet. ML SM Medium dense to dense, greenish gray, silty, fine to medium SAND (SM), wet. [GLACIAL DRIFT] SP Dense, gray, fine to medium SAND (SP-SM) with silt, wet SM Bottom of boring at 16.5 ft. bgs. Ground water encountered abou 5 f . bgs during drilling. 1 50/6 Q 2 32-26-13 GS 3 0 4 0-0-2 5 3-5-6 GS 6 5-13-18 NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. Standard Penetration Test (140 lb. weight, 30" drop) ♦ Blows per foot x wm 10 20 30 40 50 O 0 BORING: =A CITY OF EDMONDS BH_2 LIFT STATION 7 REPLACEMENT F WAGEOSCIENCES INC. EDMONDS, WASHINGTON. PAGE: 1 of 1 PROJECT NO.: 2004-069 FIGURE: A-3 BORING 2004069.GPJ 516/05 1 5- 1 10- 1 15- 1 20- 1 25 - DRQLLING COMPANY: Holocene Drilling SURFACE ELEVATION: 13.35 t feet DATE STARTED: 3/2/2005 DRILLING METHOD: Hollow Stem Auger DATE COMPLETED: 3/2/2005 SAMPLING METHOD: Standard Penetration Test LOGGED BY: G. Emens LOCATION: Refer to Figure 2 U J_ J O U1 0-Co U 0 —1 mmm SM 4 in. asphalt and crushed gravel base. Dark brown to dark gray, fine to medium, silty SAND (SM) with fine gravel, moist.' [FILL] Seven inches of recovery. OL Soft, dark olive brown, sandy, ORGANIC SILT (OL), wet [MARSH DEPOSITS] ---------------------- SM Loose to medium dense, brownish gray, very silty SAND (SM), wet. SW Medium dense, brownish gray, SAND (SW-SM) with silt, SM wet [GLACIAL DRIFT] ---------------------- SP Dense to very dense, dark brown and gray, clean SAND (SP), with sub -rounded, fine gravel, wet Approximately 1-foot layer of sandy, sub -rounded gravel with silt from 13 to 1_4ft. ____________ ____ SP Dense to very dense, gray, medium SAND (SP-SM) with silt SM and fine, sub -rounded gravel, wet. DESCRIPTION Bottom of boring at 16.5 ft. bgs. Standpipe piezometer installed (see schematic). Ground water level measured at Elevation 8 feet, March 28, 2005, approximately 4PM. w w U Z Standard Penetration Test Lu [D } „ t w (140 lb. weight, 30" drop) w w Lu v w a • Blows per foot w 0- o w w0- N 1: x wa a ami aaa i vi O a 0 10 20 30 40 50 a w NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. F-10 1 I-15 1 H 20 1 I `25 0 20 40 60 80 100 Water Content (%) Plastic Limit 1 0 Liquid Limit Natural Water Content BORING: CITY OF EDMONDS BH-3 LIFT STATION 7 REPLACEMENT, fMGEOSaENCES INC EDMONDS, WASHINGTON PAGE: 1 of _ PROJECT NO.: 2004-069 FIGURE: A-4 PZO 2004069.GPJ 516/05 01 DR✓<LLING COMPANY: Holocene Drilling SURFACE ELEVATION: 12.71 t feet DATE STARTED: 3/3/2005 DRILLING METHOD: Hollow Stem Auger DATE COMPLETED: 3/3/2005 SAMPLING METHOD: Standard Penetration Test LOGGED BY: G. Emens LOCATION: Refer to Figure 2 U w z Standard Penetration Test Jr m D m u U) W v (140 lb. weight. 30" drop) Lu a •Blows per foot m w w W, } wy rV 0 N Z) DESCRIPTION Q m Q rn W 2 o- O WU a vn Wm 0 0 10 20 30 40 50 0 r0 1 5 1 10 I 15 1 20 1 25 SM 4 in. asphalt and crushed ravel base. Very loose to loose, dark brown and gray, silty SAND (SM) with fine gravel and organics, moist. Glass shards present. [FILL] PT Soft, reddish brown PEAT (PT), moist. [MARSH DEPOSITS] SP Medium dense to very dense, dark gray, clean to slightly silty, medium SAND with coarse sand and fine gravel, wet. [GLACIAL DRIFT] Very dense, dark gray, clean to slightly silty, slightly SP SM gravelly, medium SAND, wet. FA 1 4-1-1 GS 2 5-2-2 3 0-0-2 4 0-9.8 5 10-18-25 GS 6 16-28-39 7 18-28-30 8 12-47-44 GS NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. ♦ : : • i 5 1 10 1 ♦: _» 15 0 20 40 60 80 Water Content (%) Plastic Limit I--0 Liquid Limit Natural Water Content BORING: CITY OF EDMONDS U01, BH-4 LIFT STATION 7 REPLACEMENT HMGEOSCIENCES INC EDMONDS, WASHINGTON PAGE: 1 of 2 PROJECT NO.: 2004-069 FIGURE: A-5 PZO 2004069.GPJ 5/6/05 DFj LLING COMPANY: Holocene Drilling SURFACE ELEVATION: 12.71 t feet DATE STARTED: 3/3/2005 DRILLING METHOD: Hollow Stem Auger DATE COMPLETED: 3/3/2005 SAMPLING METHOD: Standard Penetration Test LOGGED BY: G. Emens LOCATION: Refer to Figure 2 cn U) U J O V) a y U w 0 rn 25- 1 30 1 35 1 40 DESCRIPTION mz w Standard Penetration Test Y N r w v (140 lb. weight, 30" drop) w e w¢ •Blows per foot w w a- a f° 3 w Ow a z ° x w x o - w n r(n a " O a vi 0 10 20 30 40' o 50 9 50/6 GS 7 25 SM Very dense, greenish gray, very silty SAND (SM) with fine, sub -rounded gravel, moist. Diamicton. [TILL -LIKE DRIFT] Hard dilling below 25 feet. Bottom of boring at 40.3 feet BGS. Standpipe piezometer installed (see schematic). Ground water measured at Elevation 8.2 feet, March 28, 2005, approximately 4:30PM. 10 50/5 11 50/4 12 50/4 NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. 40 1 45 1 ' `50 0 20 40 60 80 100 Water Content (%) Plastic Limit 1-0-1 Liquid Limit Natural Water Content CITY OF EDMONDS BORING: BH-4 LIFT STATION 7 REPLACEMENT HMGEOSCIENCES INC EDMONDS, WASHINGTON PAGE: 2 of 2 PROJECT NO.: 2004-069 FIGURE: A-5 PZO 2004069.GPJ 516105 Hydraulic Conductivity Analysis Well No. BH-1 Bouwer and Rice Method Rising Head For Partially Penetrating Wells Casing Effective Screen Length of Static to Bottom Static to Bottom Radius Radius Eff. Screen of Eff. Screen of Aquifer time and drawdown points r, rw d b D 1 (min) t (min) ho (ft) ht (ft) 0.083 70.333 8.5 11 '20 1 6.4 2.9 1. .; Filter Eff. Casing Porosity Radius 0.459, 0.234 A B d/r. (from curve) (from curve) K 25.53 -2.1 .. "; 0`6. 1.4E-04 ft/min 7.2E-05 cm/sec Well No. BH-1 Falling Head Casing Effective Screen Length of Static to Bottom Static to Bottom Radius Radius Eff. Screen of Eff. Screen of Aquifer time and drawdown points rc r,,,, d b D 1 (min) t (min) ho (ft) ht (ft) 0.083 0.333 8.5 11 20 1 6 °'. 2, 1. Filter Eff. Casing Porosity Radius 0.459 0.234 A B d/rw (from curve) (from curve) K 25.53 2.1 0.6 9.9E-05 ft/min 5.0E-05 cm/sec SLUG TEST ANALYSIS - 131-1-1 If"T , I HWAGEOSCIENCES INC. I LIFT STATION 7/8 EDMONDS, WASHINGTON FIGURE NO. A-6 PROJECT NO. 2004-069 Hydraulic Conductivity Analysis Bouwer and Rice Method For Partially Penetrating Wells Well No. BH-3 Rising Head Casing Effective Screen Length of Static to Bottom Static to Bottom Radius Radius Eff. Screen of Eff. Screen of Aquifer time and drawdown points . r, rw d b D 1 (min) t (min) ho (ft) ht (ft) 0.083 0.333 10 10.6 20 1 0.35 1.5 0:1..:.. Filter Eff. Casing Porosity Radius 0.459—, 0.234 A B d/rw (from curve) (from curve) K . 30.03 2 1.:: '0.6 5.9E-03 ft/min 3.0E-03 cm/sec Well No. BH-3 Falling Head Casing Effective Screen Length of Static to Bottom Static to Bottom Radius Radius Eff. Screen of Eff. Screen of Aquifer time and drawdown points r. rw d b D 1 (min) t (min) ho (ft) ht (ft) 0.083 0.333 10 10.6 20 1 0:24 Filter Eff. Casing Porosity Radius 0.459 0.234 A B d/rw (from curve) (from curve) K 30.03 2.1 0.6 9.5E-03 fUrnin 4.8E-03 cm/sec SLUG TEST ANALYSIS - 131-1-3 CITY OF EDMONDS �, HWAGEOSCIENCES INC. LIFT STATION 7 REPLACEMENT EDMONDS, WASHINGTON FIGURE NO. A-7 PROJECT NO. 2004-069 Hydraulic Conductivity Analysis Bouwer and Rice Method For Partially Penetrating Wells Well No. BH-4 Rising Head Casing Effective Screen Length of Static to Bottom Static to Bottom Radius Radius Eff. Screen of Eff. Screen of Aquifer time and drawdown points rc rw d b D 1. (min) t (min) ho (ft) ht (ft) ..0.083 0.333 14 '22.3 25 1 .0.55 1:8 0.15 :- Filter Eff. Casing Porosity Radius 0.234 A B d/rw (from curve) (from curve) K 42.04 3 0.9 2.9E-03 ft/min 1.5E-03 cm/sec Well No. BH-4 Falling Head Casing Effective Screen Length of Static to Bottom Static to Bottom Radius Radius Eff. Screen of Eff. Screen of Aquifer time and drawdown points. fc rw d b D 1 (min) t (min) ho (ft) ht (ft) 0.083 0.333 14 22.3 25 1 0.3 .2.3 0.4 Filter Eff. Casing Porosity Radius 0.459 0.234 A B d/rw (from curve) (from curve) 42.04 3 0.9 . K 3.8E-03 ft/min 1.9E-03 cm/sec SLUG TEST ANALYSIS - 131-11-4 CITY OF EDMONDS HWAGEOSCIENCES INC. LIFT STATION 7 REPLACEMENT EDMONDS, WASHINGTON FIGURE NO. wiO r NO. 2004-069 12 10 8 J d co 6 d m u_ ..r o 4 M m w `m 2 M 3 c 0 0 x -2 -4 +- 8-Aug 10-Aug 12-Aug 14-Aug GBH-1 Puget Sound 16-Aug 18-Aug 20-Aug 22-Aug 24-Aug 26-Aug Date and Time 12 10 8 J 6 .n° cv m as u_ 4 c 0 d w 2 '° c 0 co m 0 a -2 --4- -4 28-Aug TIDAL INFLUENCE OF GROUNDWATER AT BH-1 FIGURE NO. %A [� T �7 S INCIFT STATIONS 7&8 ��� 1. ; Gt S ..ElVC�J 1IVPROJECT NO. CITY OF EDMONDS EDMONDS, WASHINGTON 2004-069 12 10 8 J d 6 a� m U. 0 4 w �o as w `m 2 �o 3 a - c 0 0 0 -2 -4 4- 8-Aug a GBH-3 —� Puget Sound 12 10 8 J d 6 .r m d U. 4 c 0 co d w 2 a c 0 d 0 a -2 m 10-Aug 12-Aug 14-Aug 16-Aug 18-Aug 20-Aug 22-Aug 24-Aug 26-Aug 28-Aug Date and Time - TIDAL INFLUENCE OF GROUNDWATER AT BH 3 FIGURE NO. LIFT STATIONS 7&8 A10 HWAGEOSCIENCES INC: CITY OF EDMONDS PROJECT NO., EDMONDS, WASHINGTON 2004-069 12 10 8 J d .0 6 M d m LL 0 4 M d w `m 2 �o 3 -o c 0 0 z� -2 -4 -I-- 8-Aug GBH-4 —�- Puget Sound 12 . 10 8 J d 6 ra d d LL 4 c 0 d w 2 c 0 -w m 0 . 0 a -2 -4 10-Aug 12-Aug 14-Aug 16-Aug 18-Aug 20-Aug 22-Aug 24-Aug 26-Aug 28-Aug Date and Time TIDAL INFLUENCE OF GROUNDWATER AT BH-4 FIGURE NO. '* HWAGEOSCIENCES INC LIFT. STATIONS 7&8 ■ ■,1 PROJECT NO. Y iir CITY OF EDMONDS EDMONDS, WASHINGTON 2004-069 APPENDIX B LABORATORY TESTING APPENDIX B LABORATORY TESTING Representative soil samples obtained from the borings were returned to the HWA laboratory for further examination and testing. Laboratory tests were conducted on selected soil samples to characterize relevant engineering properties of the on -site materials. The laboratory testing program was performed in general accordance with appropriate ASTM Standards as outlined below. MOISTURE CONTENT: The moisture content of selected soil samples were determined in general accordance with ASTM D 2216. The results are shown at the sampled intervals on the appropriate summary logs in Appendix A. PARTICLE SIZE ANALYSIS OF SOILS: Selected samples were tested to determine the particle distribution of material in general accordance with ASTM D422. The results are summarized on the attached Grain Size Distribution reports, Figures B-1 through B-4, which also provide information regarding the classification of the sample and the moisture content at the time of testing. 2004069 Draft Report.doc B-1 I HWA GEOSCIENCES INC. GRAVEL I SAND SILT CLAY Coarse Fine Coarse Medium Fine 3/4" 1 U.S. STANDARD SIEVE SIZES 100 90 80 70 W 60 ca Of W 50 z LL �— 40 Z U w 30 W CL 20 10 SYMBOL SAMPLE DEPTH (ft) CLASSIFICATION OF SOIL- ASTM D2487 Group Symbol and Name % MC LL I PL PI I Gravel Sand Fiones . • BH-1 1 2.5 - 4.0 (SM) Dark brown, silty SAND 8 12.9 69.7 17.4 ■ BH-1 3 7.5 - 9.0 (SM) Dark brownish gray, silty SAND with gravel 39 18.9 62.0 19.1 ♦ BH-2 2 5.0 - 6.5 (SM) Dark brown, silty SAND with gravel 11 16.3 67.4 16.3 CITY OF EDMONDS PARTICLE -SIZE ANALYSIS LIFT STATION 7 REPLACEMENT OF SOILS METHOD ASTM D422 HWAGEOSCIENCES INC. EDMONDS, WASHINGTON PROJECT NO.: 2004-069 FIGURE: B-1 HWAGRSZ 2004069.GPJ 5/6/05 ' Ii1N I li� II GRAVEL SAND SILT CLAY Coarse Fine Coarse Medium Fine SYMBOL SAMPLE DEPTH (ft) CLASSIFICATION OF SOIL- ASTM D2487 Group Symbol and Name % MC LL PL pl Gravel Sand Fines • BH-2 5 12.5 - 14.0 (ML) Light olive gray, sandy SILT 17 1.1 47.3 51.6 ■ BH-3 2 5.0 - 6.5 (OL) Dark olive brown, sandy SILT with organics 50 0.4 27.3 72.3 ♦ BH-3 3 7.5 - 9.0 (SM) Brownish gray, silty SAND and 2.3 %organics 36 0.6 57.2 42.2 CITY OF EDMONDS PARTICLE -SIZE ANALYSIS LIFT STATION 7 REPLACEMENT OF SOILS HWAGEOSCIENCES INC. EDMONDS, WASHINGTOty METHOD ASTM D422 PROJECT NO.: 2004-069 FIGURE: B-2 HWAGRSZ 2004069.GPJ 5/6l05 as �s GRAVEL SAND SILT CLAY Coarse Fine Coarse Medium Fine SYMBOL SAMPLE DEPTH (ft) CLASSIFICATION OF SOIL- ASTM D2487 Group Symbol and Name % MC LL PL pl Gravel Sand Fines 0 BH-3 4 10.0 - 11.5 (SW-SM) Brownish gray, well graded SAND with silt 24 4.5. 85.7 9.8 ■ BH-3 5 12.5 - 14.0 (SP) Dark grayish brown, poorly graded SAND 17 12.2 85.4 2.5 A BH-4 1 2.5 - 4.0 (SM) Dark brown 8� gray, silty SAND with gravel 25 25.9 55.8 18.3 CITY OF EDMONDS PARTICLE -SIZE ANALYSIS �■�� LIFT STATION 7 REPLACEMENT OF SOILS HWAGEOSCIENCES INC. EDMONDS, WASHINGTON METHOD ASTM D422 PROJECT NO.: 2004-069 FIGURE: B-3 HWAGRS2 2004069.GPJ 5/6/05 GRAVEL SAND SILT CLAY I WE i Coarse Fine Coarse Medium Fine SYMBOL SAMPLE DEPTH (ft) CLASSIFICATION OF SOIL- ASTM D2487 Group Symbol and. Name % MC LL PL pl Gravel Sand Fines • BH-4 5 12.5 - 14.0 (SP) Dark gray, poorly graded SAND with gravel 19 16.5 80.0 3.5 ■ BH-4 8 20.0 - 21.5 (SP-SM) Dark gray, poorly graded SAND with silt and gravel 8 37.5 54.9 7.5 A BH-4 9 25.0 - 25.5 (SM) Gray, silty SAND with gravel 9 22.4 45.5 32.1 CITY OF EDMONDS PARTICLE -SIZE ANALYSIS LIFT STATION 7 REPLACEMENT OF SOILS HWAGEOSCIENCES INC. METHOD ASTM D422 PROJECT NO.: 2004-069 FIGURE: B-4 EDMONDS, WASHINGTON HWAGRSZ 2004069.GPJ 5/6/05 APPENDIX C LOG OF PREVIOUS BORING B-4 CDM (2004) vveu or BoringLog B-4 Piezometer z - 9 Completion L^ Eo o mm o m . N a DESCRIPTION u Or i n �U 00 aarty0 N D rn 3 Inches Asphalt 10 GSD G-1 1.3 0 Gw 1 Inch Subbase. GSD 6-1 2.8 t GRAVEL with sand (GW) I t Dark gray, loose, moist, fine to coarse sand, fine to f I coarse subangular gravel, abundant asphalt debris I 2 Fdl. S t 11.3 0 2 2 SP-SM .. SAND with silt and gravel (SP-SM) 0 Brown, very loose, wet, poorly -graded sand, fine to coarse subrounded gravel, scattered organics, some asphalt debris (Fill)- - 4 Grades to silty sand with fine rounded gravel. - — — — — — — — — — — — — — — — — — — — — — — — 6 — ORGANIC SILT with silt (OL) S-2 121 0 o 0 Dark brown, very soft, moist to wet, trace fine to o medium sand, low plasticity, scattered organics 6 (Wetland and Marsh Deposits). OL 4 0 G-2 175 0 0 S-3a 94 0 0 3 — — — — — — — — — — — — — — — — — — — — — — — S 3b 20.8 0.3 3. - — SAND (SP) 2 5 Gray, loose to medium dense, wet, poorly -graded tine to medium sand (Recessional Outwash Deposits). S-4 15-1 0 5 9 1O SP 0 _ 12 12 — SAND with silt and grawel (SP-SM) S-5 0 6 10 Gray, medium dense, poorly -graded fine to coarse 2 15 sand, fine rounded gravel- SP-SM - _ - 14 -4 S-6 0 24 — GRAVEL with silt and sand (GP GM) 26 Gray, dense to very dense, wet, fine rounded gravel, 16 o fine to coarse sand (Recessional Outwash ° Deposits)- -6 S-7 29 0 43 GRGM > 38 18 LU cc -8 8 0 C ° - 0 S-8 19 0 .27 20 —11.1 0 — — --— — — — — — — — SAND with silt and gravel (SP-SM) -10 - > 30 Gray, very dense, wet, fine to coarse sand, fine m1 SPSM rounded gravel (Recessional Outwash Deposits). f Boring terminated at 21-5 ft bgs- 22 Groundwater encountered. at 8 f1 bgs during drilling- CL Groundwater encountered at 4.5 It bgs on April 30, -12 $ N 2004. - Y F v' m 24 N -14 J J 3 - - Location: See Site Plan Drill Rig: CME-95 x � Surface Elevation: 10.5' Equipment/Hammer HSA/SPT/140t1/30' i Logged By: KIS Date Completed: 4-30-04 Q m Sound Transit Commuter.Rail System o Edmonds Transit Station o Edmonds, Washington Boring Log .6-4 . Figure: A-5 caul Project No: 22107.42726 1 of 1