Loading...
HomeMy WebLinkAboutSWP272704(4) GEOTECHNICAL REPORT OLYMPIC PIPELINE CULVERT REPLACEMENT SW 23RD STREET AND LIND AVENUE RENTON,WASHINGTON HWA Project No. 8919-100 July 10, 1997 SWAM 101RAF Prepared for: R.W. Beck U Ili EONGWEST ar ASSOCIATES. INC. DRAFT u flONGWEST & ASSOCIATES, INC. July 10, 1997 Geotechnical Engineering HWA Project No. 8919-100 Hydrogeology Geoenvironmental Services R.W. Beck Testing & Inspection 1001 Fourth Avenue, Suite 2500 Seattle, Washington 98154 Attention: Mr. Michael Giseburt, P.E. Subject: OLYMPIC PIPELINE CULVERT REPLACEMENT SW 23'd Street and Lind Avenue Renton, Washington Dear Mr. Giseburt: Pursuant with your request, Hong West & Associates, Inc. performed a geotechnical engineering study for the proposed Olympic Pipeline Culvert Replacement project in Renton, Washington. The results of our study are presented in the accompanying report. 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 call. Sincerely, HONG WEST& ASSOCIATES, INC. David L. Sowers, P.E. Scott L. Hardman, P.E. Geotechnical Engineer Senior Geotechnical Engineer DLS:SLH:dls 19730-64th Avenue West Lynnwood,WA 98036-5904 Tel, 206-774-0106 Fax. 206-775-7506 TABLE OF CONTENTS Page 1.0 INTRODUCTION..................................................................................................... 1 1.1 GENERAL.................................................................................................. 1 1.2 PROJECT DESCRIPTION............................................................................... 1 2.0 FIELD AND LABORATORY INVESTIGATION....................................................... 2 2.1 FIELD INVESTIGATION................................................................................ 2 2.2 LABORATORY TESTING.............................................................................. 2 3.0 GEOLOGIC AND SUBSURFACE CONDITIONS.............................................................. 2 3.1 GENERAL GEOLOGIC CONDITIONS.............................................................. 2 3.2 SUBSURFACE CONDITIONS......................................................................... 3 3.3 GROUNDWATER CONDITIONS..................................................................... 3 4.0 CONCLUSIONS AND RECOMMENDATIONS............................................................... 4 4.1 GENERAL .................................................................................................. 4 4.2 SEISMIC DESIGN PARAMETERS................................................................... 4 4.3 EXCAVATIONS AND TEMPORARY SHORING................................................ 5 4.3.1 Unsupported Sloped Excavations................................................ 5 4.3.2 Temporary Shoring..................................................................... 6 4.4 GROUNDWATER CONTROL/DEWATERING................................................... 6 4.5 CULVERT STRUCTURE................................................................................ 8 4.5.1 Subgrade Preparation and Foundation Support........................... 8 4.5.2 Lateral Earth Pressures............................................................... 8 4.5.3 Estimated Settlement.................................................................. 9 4.6 BACKFILL PLACEMENT AND COMPACTION ................................................. 10 5.0 UNCERTAINTIES AND LIMITATIONS........................................................................ 10 6.0 REFERENCES .................................................................................................... 12 LIST OF FIGURES(FOLLOWING TEXT Figure 1. Vicinity Map Figure 2. Site and Exploration Plan Figure 3. Earth Pressures for Temporary Shoring Figure 4. Lateral Earth Pressures for Permanent Structures Appendix A: Field Exploration Figure A-1, Legend of Terms and Symbols Used on Exploration Logs Figure A-2. Log of Boring BH-1 Appendix B: Laboratory Investigation Figure B-1. Grain Size Distribution Test Results GEOTECHNICAL REPORT OLYMPIC PIPELINE CULVERT REPLACEMENT SW 23RD AVENUE AND LIND AVENUE RENTON, WASHINGTON 1.0 INTRODUCTION 1.1 GENERAL This report presents the results of our geotechnical study for the proposed Olympic Pipeline Culvert Replacement project in Renton, Washington. The purpose of this study was to explore and evaluate the surface and subsurface conditions at the site, and provide geotechnical recommendations for design and construction of a concrete box culvert to replace two existing metal culverts. A summary of our findings and evaluation of site conditions is presented in this report. A proposal for the performance of this geotechnical investigation was submitted by HWA to R.W. Beck, dated May 2, 1997. Authorization to proceed with this scope of work was subsequently given by R.W. Beck in a Subconsultant Agreement dated June 18, 1997. The scope of work completed for the project, as described herein, was in general agreement with that outlined in the Subconsultant Agreement, 1.2 PROJECT DESCRIPTION Our understanding of the Olympic Pipeline Culvert Replacement project is based on discussions with and information provided by Mr. Scott Woodbury with the City of Renton, and Mr. Mike Giseburt of R.W. Beck. The existing and proposed culverts are shown on Figure 2. Pre ntly, surface water flows through two, 80-foot long, 18-inch diameter metal culverts to s a small pond immediately west of Lind Avenue. The proposed culvert replacement project will involve removing the two existing culverts and replacing them with a single 10-foot wide by 4- v foot high (inside dimensions) concrete structure approximatelyXfeet long. Wall thickness is anticipated to be about 8 inches. In the vicinity of the proposed replacement culvert are several other utilities, including a Seattle Water Department water line and three Olympic Pipeline petroleum pipelines. The design of the box culvert is preliminary as of the date of this report. The box culvert may be constructed using precast concrete sections, or will be cast-in-place. The proposed culvert may be fitted with wing walls as shown on Figure 2. However, an alternative design concept is under consideration which would involve construction of a July 10, 1997 HWA Project No. 8919-100 longer culvert without wing walls. Should design changes occur which result in a design concept significantly different from that described herein, HWA should be notified for review of our geotechnical recommendations and revision of such if necessary based on the new design concept. 2.0 FIELD AND LABORATORY INVESTIGATION 2.1 FIELD INVESTIGATION On June 20, 1997, a geotechnical engineer from HWA logged the drilling of one 39-foot deep boring (BH-1) at the approximate location shown on the Site and Exploration Plan, Figure 2. The boring was performed to evaluate the presence and depth to groundwater, and soil conditions at the site. The boring was drilled with a track-mounted Mobile drill rig, owned and operated by Holocene Drilling of Pacific, Washington under subcontract to HWA. Appendix A presents additional information regarding field exploration methods. As part of the exploration program, HWA personnel recorded pertinent information including soil sample depths, stratigraphy, soil engineering characteristics, and groundwater occurrence. Soils were classified in the field in general accordance with the classification system described on Figure A-l. A key to the exploration log symbols is also presented on Figure A-1. The boring log is presented on Figure A-2. 2.2 LABORATORY TESTING Soil samples obtained at selected intervals within the boring were placed in air-tight bags and taken to our laboratory for further examination and testing. Select soil samples were tested for in situ moisture content and grain size distribution. Discussions of laboratory test methodology and test results are presented in Appendix B. 3.0 GEOLOGIC AND SUBSURFACE CONDITIONS 3.1 GENERAL GEOLOGIC CONDITIONS Geologic information for the site was obtained from the Geologic Map of the Renton Quadrangle, King County, Washington (Mullineaux, 1965). The geologic map indicates that the area is generally underlain by peat and alluvial deposits. Alluvium, or river- deposited soils, typically consist of interbedded, discontinuous layers of sand, silt, clay, and organic soils. Recent alluvium is typically unconsolidated and generally exhibits low shear strength and high compressibility. Regional geologic information was also obtained from previous geotechnical studies in the vicinity of the project (GeoEnaineers, 1992; Hong Consulting Engineers, 1989). In 8919100 2 HONG WEST& ASSOCIATES, INC. July 10, 1997 HWA Project No. 8919-100 evaluating geotechnical is�. for the project, we also relied on borings completed nearby for the ongoing e project. Results of explorations completed for that project will be presented in a forthcoming report. 3.2 SUBSURFACE CONDITIONS Based on the results of our explorations, the site appears underlain by alluvial sands and silts, consistent with the geologic map. Locally, the alluvium appears overlain by fill soils used to backfill the existing utilities and construct the access road. The subsurface units encountered in the explorations are described below in the order of stratigraphic sequence in which they were deposited, with the youngest units described first: • Fill: Fill materials were observed extending about 5 feet below the ground surface. The fill soils generally consisted of loose, poorly graded sand with silt, with interbeds of silt and clay with organic matter. In our opinion, these fill materials were used to construct the Seattle Water Department's access road and for backfill of the water line. The proposed location of the new culvert is off the edge of this access road, and consequently we do not anticipate these fill materials will be encountered along the proposed culvert alignment. Some fill soils may be encountered, associated with the existing Olympic Pipeline petroleum lines which cross the proposed culvert alignment. • Alluvium: Alluvial soils were encountered directly beneath the fill in boring BH-1. The alluvium consisted generally of interbedded, very loose to medium dense sand and silty sand, to very soft to very stiff silt with varying amounts of sand. The alluvium extended to the full depth of the boring. Although extensive deposits of peat and organic soils are common in the Duwamish Valley, significant layers of such materials were not encountered in the boring conducted on site. However, this does not preclude the possible presence of organic soils and peat in localized areas under the culvert alignment. 3.3 GROUNDWATER CONDITIONS Groundwater seepage was observed in the exploration at a depth of 5 feet below the existing ground surface (approximately Elevation 11 feet). Seepage was observed during drilling near the contact between the fill materials and the underlying alluvium deposit. Standing water was observed in wetland areas at the project site. It is anticipated that groundwater conditions will change in response to rainfall, time of year, and other factors. 8919100 3 HONG WEST&ASSOCIATES, INC. _ July 10, 1997 HWA Project No. 8919-100 4.0 CONCLUSIONS AND RECOMMENDATIONS 4.1 GENERAL We understand that the invert elevation of the box culvert will be at approximately Elevation 6.5 feet (based on datum NAVD88). At the time of our field investigation the groundwater level was observed at 5 feet below the existing ground surface, or about Elevation 11 feet. Consequently, dewatering measures will be required before excavating begins. We anticipate dewatering can be accomplished using a combination of sumps and wellpoints. Use of deep wells would also be feasible to facilitate dewatering. As proposed, installation of the proposed box culvert will involve conventional open cuts. Providing the site is dewatered below the depth of the cut, temporary excavations can be sloped at 1'/2H:1V (horizontal:vertical) or flatter. The use of sheet piling to shore excavations may be necessary in areas where dewatering and excavations would otherwise impact existing utilities and roadways. Based on the conditions encountered in our exploration, the proposed box culvert is underlain by soils capable of supporting the anticipated structural loads. We anticipate that the weight of the new structure will be slightly greater than the weight of soil replaced 1.7 by the structure. Consequently, settlement on the order of 1 inch is anticipated from the additional loads. Before placing the new concrete culvert, subgrade preparation at the invert elevation may require placing a slab of lean concrete, or tremie slab, where loose, saturated soils are encountered. If these subgrade soils can be dewatered, a working pad of crushed rock could be used instead. Some overexcavation of the subgrade will be required to place either the tremie slab or crushed rock pad. Additional overexcavations may be needed if highly organic soils or peat are encountered at subgrade elevations. Geotechnical recommendations for seismic design, excavations and temporary shoring, groundwater control/dewatering, culvert structure design, and backfill placement and compaction are discussed in further detail in the following sections. 4.2 SEISMIC DESIGN PARAMETERS The project alignment lies within Seismic Zone 3 as defined by the Uniform Building Code (UBC, 1994). Seismic Zone 3 includes the Puget Sound region, and represents an area susceptible to moderately high seismic activity. For comparison, much of California and southern Alaska are defined as Seismic Zone 4, which is an area of higher seismic risk. Consequently, moderate levels of earthquake shaking should be anticipated during the design life of the proposed pipeline. Based on the soils encountered during the 8919100 4 HONG WEST&AssociATEs, INC. July 10, 1997 HWA Project No. 8919-100 exploration program, UBC soil profile type S3 should be assumed for the project. For use in design, this soil profile type corresponds to a Site Coefficient of 1.5. Detailed evaluation of soil liquefaction potential is beyond the scope of our work. Based on our previous experience with similar soil conditions in Western Washington, the liquefaction potential of site soils is considered moderate to high during a strong seismic event. In particular, loose sandy soil layers beneath the site are susceptible to liquefaction. Potential effects of soil liquefaction include temporary loss of bearing capacity, liquefaction-induced settlement, and lateral spreading, which could result in damage to the proposed culvert. It should be noted that the site is anticipated to have no greater seismic risk than surrounding developments. While the proposed culvert construction will not mitigate the potential for seismic-induced liquefaction, installation of the culvert is not anticipated to increase seismic risk or soil liquefaction potential at the site. 4.3 EXCAVATIONS AND TEMPORARY SHORING We understand conventional open excavations will be the primary method for installation of the replacement culvert. Excavations are anticipated to have maximum depths on the order of 10 feet below the existing ground surface along the box culvert alignment. We anticipate excavation for the box culvert can be accomplished with conventional equipment such as backhoes and trackhoes. Excavation and construction of the new culvert must be performed in a manner which will not impact existing utilities. Shoring may be required in areas where the excavations encroach upon the utilities. Temporary support and protection of the Olympic Pipeline petroleum lines must be provided and maintained during construction. This may require the use of struts or saddles to temporarily support the existing pipelines and minimize sagging. We"recommend that the contractor be required to submit a dewatering and shoring/excavation.plan for the review of the project engineer prior to construction. The plan should be required to contain specific measures for temporary support and protection of the existing utilities. Recommendations for unsupported sloped excavations and temporary shoring are presented in the following sections. 4.3.1 Unsupported Sloped Excavations Maintenance of safe working conditions, including temporary excavation stability, is the responsibility of the contractor. All temporary cuts in excess of 4 feet in height should be sloped in accordance with Part N of WAC (Washington Administrative Code) 296-155 or shored. The existing fill and native sands and silts are generally classified as Type C soil. Excavations in Type C soils should be inclined no steeper than 1'AH:1 V 8919100 5 HONG WEST& ASSOCIATES, INC. July 10, 1997 HWA Project No. 8919-100 (horizontal:vertical). The recommended allowable cut slope inclinations are applicable to excavations above the water table only; flatter side slopes will be required for excavations below the water table. With time and the presence of seepage and/or precipitation, the stability of temporary unsupported cut slopes can be significantly reduced. Therefore, all temporary slopes should be protected from erosion by installing a surface water diversion ditch or berm at the top of the slope and by covering the cut face with well-anchored plastic sheets. In addition, the contractor should monitor the stability of the temporary cut slopes and adjust the construction schedule and slope inclination accordingly. 4.3.2 Temporary Shoring Sheet pile walls are considered suitable for temporary support of excavations in areas where open-cut excavations are not feasible or where additional support is required for protection of existing utilities. General recommendations for design and implementation of shoring systems for the project are presented below. • Design parameters for sheet pile walls used along the pipeline alignment are shown on Figure 3. Such sheet pile walls should be designed and constructed to support an equivalent fluid pressure of 21 pounds per cubic foot (pcf), plus hydrostatic water pressure (unit weight of water equal to 62.4 pcf). Surcharge loads from construction equipment, construction materials, excavated soils, or vehicular traffic should also be included in the shoring design. These recommended values assume that groundwater will be drawn down from within sheet pile supported areas. • To minimize the potential for excessive sheet pile deflections, use of horizontal bracing may be needed to provided additional lateral support. • Precautions should be taken during removal of the shoring or sheeting materials to minimize disturbance to the culvert and underlying materials, underlying bedding materials, natural soils, and adjacent utilities. 4.4 GROUNDWATER CONTROUDEWATERING Results of the field exploration program indicate that groundwater will be encountered during construction of the replacement culvert. Therefore, the need for temporary construction dewatering should be anticipated. Based on the soils encountered and the proposed depth of excavation, it is our opinion that dewatering using a combination of wellpoints and sumps will be appropriate for the proposed box culvert. It is the contractor's responsibility to design, construct, and maintain an effective dewatering system. Prior to construction, the contractor should determine an appropriate dewatering 8919100 6 HONG WEST&ASSOCIATES, INC. July 10, 1997 HWA Project No. 8919-100 scheme and submit a dewatering plan to the engineer for review. For preliminary planning and costing purposes, the following general assessments are provided. Use of conventional wellpoints is considered appropriate for areas where soft silt with sand deposits are present. For open-cut excavations, we estimate wellpoints on 2'/2 to 5 foot centers around the perimeter of the excavation will be required. Wellpoints should extend 15 to 20 feet deep. Sumps may be used in conjunction with the wellpoints; however, we consider it unlikely that dewatering can be accomplished entirely using sumps. Another alternative for construction dewatering is the use of deep wells. We estimate 25-foot deep wells installed at 20 feet on center would be required, as a minimum. Groundwater seepage into the open excavation will tend to destabilize side slopes and increase lateral loads on shoring systems. In addition groundwater flow into the excavation can cause sand boils or heaving at the bottom of excavations. Because of these impacts dewatering should be accomplished so that excavating and construction of the culvert can be completed in the dry. We recommend that temporary excavations be dewatered to maintain the groundwater level at least 2 feet below the base of the excavation. Dewatering should continue until the culvert has been placed and backfilled, and is capable of resisting hydrostatic forces. Extended dewatering could result in lowering the water table over a large area which would cause settlement of the underlying alluvial soils. The magnitude of the settlement and its lateral extent would depend on the amount of change in the water level; the length of time the water level was lowered; and the compressibility, thickness, and permeability of the underlying soils. Based on the soil conditions encountered during our site investigation, we estimate that for a 7-foot deep open-cut excavation, areas that may be impacted by groundwater drawdown could extend about 40 to 50 feet away from dewatered excavations. We estimate maximum settlements resulting from the anticipated dewatering operations would be on the order of 1'/2 to 2 inches. Settlement will be greatest where groundwater drawdown is at a maximum, and will decrease with increasing distance from the dewatered area. Dewatering within a sheet pile enclosed excavation with sufficient sheet pile embedment acting as a cut-off wall to groundwater flow will result in less groundwater discharge and drawdown over smaller areas. The extent of dewatering-related groundwater drawdown should be monitored during construction to minimize the potential for settlement damage. A contingency should be provided for installation of recharge wells should the dewatering system result in significant lowering of groundwater levels beneath the existing utilities and roadways. 8919100 7 HONG WEST&ASSOCIATES, INC. July 10, 1997 HWA Project No. 8919-100 4.5 CULVERT STRUCTURE 4.5.1 Subgrade Preparation and Foundation Support Based on the results of our explorations, we anticipate very soft silt to very loose sand will be encountered at/near the proposed base of the box culvert. Before placing the box culvert, we recommend stabilizing the subgrade with the use of either a crushed rock or lean concrete working surface. A lean concrete working surface, or tremie slab, can be poured directly on the subgrade in either dry or wet conditions. We recommend the tremie slab be a minimum of 12 inches thick, requiring overexcavations extending into the subgrade a similar depth. For the crushed rock working surface, overexcavation of the subgrade should extend a minimum of 2 feet below the proposed base elevation of the culvert. The excavation should be adequately dewatered and dry before placing crushed rock fill. Placement of these surfaces will help to minimize damage to the subgrade soil during placement of the box culvert, and the removal of compressible silty soils will help to minimize settlement of the structure. As discussed in Section 3.2, peat and highly organic soils were not encountered at anticipated subgrade elevations in the boring conducted for this study. However, regional geologic conditions and explorations from nearby geotechnical studies indicate the potential for discontinuous lenses and layers of peat and organic soils. In the event that compressible soils are encountered at the anticipated subgrade elevation for the tremie slab/crushed rock pad, the unsuitable soils should be overexcavated and replaced. The overexcavation process, if necessary, should be observed by the geotechnical consultant. The overexcavated area should be backfilled with structural fill as described in Section 4.6. If the subgrade is prepared as described above, the alluvial sands and silts are anticipated to provide adequate foundation support. For design purposes, we recommend an allowable soil bearing pressure of 1,000 pounds per square foot (psf for use in design of the culvert structure. 4.5.2 Lateral Earth Pressures Lateral earth pressures against below-grade structures will depend upon the inclination of any adjacent slopes, type of backfill, degree of wall restraint, method of backfill placement, degree of backfill compaction, drainage provisions, and magnitude and location of any surcharge loads. At-rest soil pressure is exerted on a subsurface structure or wall when it is restrained against rotation. For this project, it is anticipated that the proposed structural walls will be restrained against rotation and will have relatively level backfill. As such, the below-grade structure 8919100 8 HONG WEST&ASSOCIATES, INC. July 10, 1997 HWA Project No. 8919-100 _ should be designed for a horizontal at-rest equivalent fluid pressure of 52 pounds per cubic foot (pcf) above the design groundwater elevation and 87 pcf below the design groundwater elevation. The value of 87 pcf includes hydrostatic pressure. The configuration of the earth pressures generated is shown on Figure 4. The above recommendations regarding at-rest earth pressures assume that the backfill behind the subsurface walls will consist of properly compacted structural fill, and does not include adjacent surcharge loads. If the below-grade structures will be subjected to the influence of surcharge loading within a horizontal distance equal to or less than the height of the walls, the walls should be designed for the additional horizontal pressure using a suitable method for modeling surcharge loads. During a seismic event, lateral earth pressures acting on below-grade structural walls will increase by an incremental amount that corresponds to the earthquake loading. A concomitant decrease in passive earth pressure also occurs. However, if at-rest earth pressures are used in design, a conservative structural design that can readily accommodate the temporary seismic overloading conditions generally results. Therefore, it is our opinion that the dynamic incremental pressures from earthquake loading may be neglected if the below-grade structures are designed based on at-rest earth pressures. Winds, earthquakes, and unbalanced earth and water loads subject structures to lateral forces. Lateral forces on a structure will be resisted by a combination of sliding resistance of its base or footing on the underlying soil and passive earth pressure against the buried portions of the structure, as shown on Figure 4. The sliding resistance of cast-in-place concrete on structural fill may be calculated using a coefficient of friction of 0.4. 4.5.3 Estimated Settlement The likely mechanisms for pipe settlement are from poor bearing support immediately below the culvert, or consolidation of underlying compressible soils under new loads. Bedding the culvert structure in accordance with the recommendations described above, including removal of soft and/or organic soils from below the alignment, will help reduce the potential for differential settlement. We anticipate the culvert and backfill will weigh slightly more than the soil it displaces. Therefore, we estimate settlements on the order of 1 inch due to the net increase in soil pressure resulting from placement of the culvert and excavation backfill. This consolidation settlement will impact the supporting backfill soils around the existing Olympic pipelines. Evaluations should be performed to verify that the existing pipelines can accommodate this magnitude of settlement, in addition to movements anticipated as a result of construction activities and dewatering. Sand boils at the bottom of the excavation or subgrade soils disturbed during construction could result in settlement of the structure. Occurrence of sand boils can be minimized by 8919100 9 HONG WEST& ASSOCIATES, INc. July 10, 1997 HWA Project No. 8 919-100 proper construction dewatering, and/or providing sufficient sheet pile embedment below the bottom of excavation to provide base stability. In the event of sand boils or subgrades disturbed by construction activities, a minimum of the upper 12 inches of disturbed material should be removed and replaced with compacted crushed rock or lean concrete. 4.6 BACKFILL PLACEMENT AND COMPACTION All materials used for backfilling overexcavations of unsuitable soils, and used for the crushed rock working surface should consist of materials meeting the requirements for Crushed Surfacing Base Course, as described in Section 9-03.9(3) of the 1996 WSDOT Standard Specifications for Road, Bridge, and Municipal Construction. We recommend that excavation backfill consist of Bank Run Gravel for Trench Backfill, as described in Section 9-03.19 of the 1996 WSDOT Standard Specifications. During placement of the initial lifts, the backfill material should not be bulldozed into the excavation or dropped directly on the structure. Furthermore, heavy vibratory equipment should not be permitted to operate directly over the structure until a minimum of 3 feet of backfill has been placed. In order to minimize subsequent settlement of the excavation backfill and potential impacts of such settlement on the existing utilities, it is recommended that backfill soils be placed in horizontal lifts less than 8 inches in thickness, and compacted to at least 95 percent of maximum dry density, as determined using test method ASTM D 1557 (Modified Proctor). The procedure to achieve proper density of compacted fill depends on the size and type of compaction equipment, the number of passes, thickness of the layer being compacted, and certain soil properties. When access restricts the use of heavy equipment, smaller equipment can be used, but the soil must be placed in thin enough lifts to achieve the required compaction. It is imperative that the contractor protect the existing pipelines during placement and compaction of backfill soils around the box culvert. 5.0 UNCERTAINTIES AND LIMITATIONS We have prepared this report for use by the City of Renton and R.W. Beck in design of a portion of this project. This report should be provided in its entirety to prospective contractors for bidding or estimating purposes; however, the conclusions and interpretations presented should not be construed as a warranty of the subsurface conditions. Experience has shown that subsurface soil and groundwater conditions can vary significantly over small distances. Inconsistent conditions can occur between explorations and may not be detected by a geotechnical study. If, during future site operations, subsurface conditions are encountered which vary appreciably from those 8919100 10 HONG WEST&ASSOCIATES, INC. July 10, 1997 HWA Project No. 8919-100 described herein, HWA should be notified for review of the recommendations of this report, and revision of such if necessary. We recommend that HWA be retained to review the plans and specifications and to monitor the geotechnical aspects of construction, particularly construction dewatering and shoring systems, excavation, subgrade preparation, bedding and backfill placement and compaction. 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 groundwater at this site. 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; the safety of others is the responsibility of the contractor. The contractor should notify the owner if he considers any of the recommended actions presented herein unsafe. O'O We appreciate this opportunity to be of service. Sincerely, HONG WEST& ASSOCIATES, INC. David L. Sowers, P.E. Scott L. Hardman, P.E. Geotechnical Engineer Senior Geotechnical Engineer 8919100 11 HONG WEST&ASSOCIATES, INC. July 10, 1997 HWA Project No. 8919-100 6.0 REFERENCES GeoEngineers, 1992,Report, Geotechnical Engineering Services, Proposed Puget Western Business Park, Renton, Washington, consultant report prepared for Puget Western, Inc., dated March 27, 1992. Hong Consulting Engineers, Inc., 1989, Geotechnical Soil Investigation, Panther Creek, SR 167—P-9 Channel Project, Renton, Washington, consultant report prepared for R.W. Beck, dated June 2, 1989. Mullineaux, D.R., 1965, Geologic Map of the Renton Quadrangle, King County, Washington, U. S. Geological Survey. Uniform Building Code, 1994, Structural Engineering Design Provisions, published by the International Conference of Building Officials, Vol. 2, 1339 p. Washington State Department of Transportation/American Public Works Association, 1996, Standard Specifications for Road, Bridge, and Municipal Construction. 8919100 12 HONG WEST&ASSOCIATES, INC. \ 1IP��!. O it - I S 1 M�! > 31 I / C 1 gTH s M Biscic"Bluer / J I afm e.� P 1 1r i e s = >7= ivwr L z e I t Reynton > TM a 3 Ni ',S I s, TukwlIs lArr > rtEMoq I --..._........_ tj I �f 16t10 cAL � Pvs ..� ' PROJECT'! LOCATION sr»�tw a s - �` com-o,,,, , I sc,1rTM _ net sw I It (sl swn Orillia D 1993 DeLormc Mapping NOT TO SCALE OLYMPIC PIPELINE VICINITY MAP CULVERT REPLACEMENT flONGWEST RENTON, WASHINGTON &ASSOCIATES, INC. PROJECT NO.: 8919-100 FIGURE: 1 D: JOB 8919-100 8919001.DwG S DMH CEITERUNF_M©N M 19. ,.—GUY WIRE: i8.0 �\\ MONUMENT C�S -- 18.0 r ANCHORS —,� i 16.A \ II 16.4 GATE JTIJTI' POLE-, ; li I WA MAIN PROITCTIVc C04ER GATEFOST q . BH-1 V-�. O t,'1 f -o— 0 O ' 07. I --_--_-- \--- --�— -- �rl'SOMHr c :. � 2 InP CULiTS / FACE OF 30' :ULvEi<T �JI + + CURB WING WALL T fP i / i I I I .......... 1 .......... .......... .......... I REMOVE EXISTING 18" CULVERTS W n Ir rF� t• �Q rq, I � � I •���i �`� �. � � �'� EXCAVATE 2'-3' WITHIN THIS AREA 22.17 I i �?.C•... .. ��`\'; i 14' WIDE x HIGH _ CUL a REMOVE SILT IN CULVER� t ; r ' I �— Y OF WEI 11u. 10' WIDE x 3' HIGH CULVERT.'-'-'-'-'-'- I d IE .2 ti (OR 10' x 4' ALTERNATIVE)• • ` i I I 0 1 :'A:. �O i :::::.•.::::.:.'• •r: I: :..1 z 4 BOUNDAR. 0 � - ND I 14 WIDE x 9' HIGH CULVERT .� ;/ l ; r T E i VER��� .w IN L SILT.................. I .I• ''� REMOVE ' � } fn I Lli / I i S/�i / I SCALE. 1"-W LEGEND �f 5 �81-1_1 BORING DESIGNATION �� OLYMPIC PIPELINE SITE AND AND APPROXIMATE LOCATION CULVERT REPLACEMENT EXPLORATION PLAN 'HONGWEST RENTON, WASHINGTON &ASSOCIATES.INC. PROJECT NO.:8919-100 FIGURE:2 REFERENCE: Base ma provided b R.W. BECK INC. D: 5 891 D919002._ ASSUME GROUNDWATER AT GROUND SURFACE FOR DESIGN CANTILEVERED SHEET PILE WALL OR SHEET PILE WALL WITH ONE LEVEL OF BRACING BRACING/STRUT H BOTTOM OF EXCAVATION 2' GROUNDWATER DRAW 2, DOWN IN EXCAVATION D 62.4(H+2) r 21(H+D) 240D ULTIMATE HYDROSTATIC ACTIVE EARTH PASSIVE EARTH PRESSURE PRESSURE PRESSURE NOTES: 1. Recommended lateral earth pressure values assume subsurface soils consist of fill and alluvium. 2. The active and passive pressures do not include the effects of wall friction. 3. Sufficient embedment should be provided to achieve base stability, and to minimize impacts of dewatering to surrounding areas. 4, Surcharge loads should be added to the active pressure where appropriate. 5. A factor of safety has not been applied to the recommended earth pressure values. 6. All units in feet and pounds. =A OLYMPIC PIPELINE EARTH PRESSURES FOR ULVERT REPLACEMENT'�"IQNG`A1EST C ENTON, WASH NGTON TEMPORARY SHORING *ASSOCIATES, INC. PROJECT NC.:8919-100 FIGURE: 3 C: JOBS 8919-100\8919003.DWG STRUCTURE H1 DESIGN GROUNDWATER LEVEL H2 + 662.4H2 l 25H2 52H1 0.4 x NORMAL FORCE 295H1 142H2 62�.4H22 AT-REST SLIDING PASSIVE EARTH PRESSURES RESISTANCE RESISTANCE NOTES 1. Hi AND H2 MEASURED IN FEET: EQUIVALENT FLUID WEIGHT IN POUNDS PER CUBIC FOOT (pcf), 2. RECOMMENDED PASSIVE RESISTANCE AND FRICTION FACTOR INCLUDE A FACTOR OF SAFETY OF ABOUT 1.5. 3. EARTH AND HYDROSTATIC PRESSURES SHOULD BE COMBINED BELOW THE DESIGN GROUNDWATER LEVEL. 4. REFER TO REPORT TEXT FOR DISCUSSION OF DESIGN GROUNDWATER LEVEL. 5. RECOMMENDED EARTH PRESSURES ASSUME PROPERLY COMPACTED STRUCTURAL FILL ADJACENT TO STRUCTURES. ASSUMPTIONS TOTAL SOIL UNIT WEIGHT 120 pcf BUOYANT SOIL UNIT WEIGHT — 57.6 pcf UNIT WEIGHT OF WATER = 62.4 pcf SOIL FRICTION ANGLE = 35' SOIL/CONCRETE FRICTION ANGLE = 30- =A OLYMPIC PIPELINE LATERAL EARTH PRESSURES CULVERT REPLACEMENT FOR PERMANENT STRUCTURES flONGWEST RENTON, WASHINGTON ASSOCIATES, INC. PROJECT NO.: 8919-100 FIGURE: 4 C: JOBS 8919-100 8919004.DWG ,7i: r .a 'ti:•• , 'i •+'.. ? .;tt^; i ( .•r _7, i 's vY 4:, ,`a,. -'7[• c .J. 'It, a,s ':� _'-r t t: «-t ,; �,.. 1 a r: f > f ;r a 3 :r Q. i i vt. } .L sY r :;8 ` r. 1 -,t 4 t"I \ 'iC.. .f't•y{ t.. In r..4.. ',•" .a F! ;.3 2S. ..t/1`h.F r•A- �.t 1 ;r. .� ..i .t,i•. a „ '�. 'r7• f• !:�'t t i't.' rr .Y': v :i? .5:�- �", .n".: `-,7..1 :r' •t.;,, .Y.4, I,' i t 0 ..�. -L, ,S.•_ .A Y . 1 J,C•�.= 'v: (. y:' .r. .={ 3.„. -• t .;• S Z`a••+3,••fo....... 1 'f :- ,.{-- li; a t f; t• d,�o .)•• S•Ci 7v j. '•r t' { 1, f r3. C.o.. •,:v. ..Y i .•.\.. .s +. S' t. ,.7+ -,3 Lt' t:. ,J 4.. .r Z. i ,:,_,��tt S.: �'�,, t k ,, c .� -r ,:.. .•! •.., s+•a.r.... .::+ .. M a. ,..\. )) = ..•a.tt'A. -?ta': ,.'_y r'+:. - i 'Ct,: ,; f \ ;r T .':+ - y1:.. i t • ! -[7,. _ ;r+ r' .+1 :-a .ro.. .•-.•.., .I d.,Y, �,• ,.,. 3t. ..+7-. , aJ.V .-+:f` Sr'(1'r .A "/ tl7. .yh?,4 q ,.S G t t, .r Sli:} t, -is'I:.H .r t r"' '} }' a, .'`l. !v •�{. •' •P! ., } S .at 's•'y s .a• .'k,,!'• t ., ,.rkr:'t. ,;i i' .S t r f y Ir.�t"t. v f r •r i s, tt -OC:i ,' y `"ra(.j pi.•y` ;. ,..:•.t 1. Met •Y J L 1.>. .✓. ..� '-J:r. i J :l: '•r•,. k, `./t•.:i. ''f.J •aa��t:;• 4 �1. {.f {,y.Jr.6.. .rt'f- ,>• S :C.,," ,r:' - r.-r •r3'~tu 't its' a rt. :T. l.. .'. .,y�: ,,;f +•y'^ •}i, .v f, „r.i,. ..4' -, t T>, ,*' `L.it .3s:[. �, !:it V. .{ r:' -S F-' !: r. ••�: h r: r. !z �1 - i�• r.:{:7 1 [ rL t r ",, n �•''y{4\L * tri' / Jt "Z• :t a!, )"r<. ., :t3 +. +� i ).r •'�.1` 3�. [ r4.- ,.J- I r'.r[• :•�r�.l r rl i:�'b:.. .c,t.... •,�'.. / ..c 1 �! �. 4"IMI 1rn. �'� * ,4. -Y ;'� Y v �.K. r.r .i..� •k. ..N .,a.. t. 1".3• .:,y t..'f �? + .1- tY. ,.r •:�'.. •1,�AY?• _i-. '•:q'a„4., .y r. .,' '.!-'d•, r' Cv" P s�' l-.:t�''•. y >'(, Y .. .L ;r' i. t -.e r 'iY. 4 '•Jr: .� +f !,.r r.. :. :fi'.,.. j y '.a.F t rr,, .!t ! .�( '7 tt %j fr•-G. r i. Y..:',A.�. 1 .�.7.ar.•1 ^.t.: r. t .::'.t J ,,,1 yy .,^S 4•�.L P" r '.J:..a... 1 t "s_s c r.. •� ri- t i, ••�.�j^. .:k-, o P tea-. .( 't. y1, ., •.+, r �! Sf. '''f ♦ '.y..-.fµn�' :•7-.. :'1. :i•'_ -! I Cx':4 L' :l •-011..,.I f S + di rr.4 K, r, ,t. ..2 +•C: f: ,s:•' %• ..t.!!• ',r 'S.La l x,. .( i.J !. + r. ,!•..•. •. J + 3 ^1: .1 -..ti -s t' .Jf r7 �. ? 1 'P 'v.1-y'f. T`;i.;J•..i r4r. -L.T. t !."< ,3:. z S r n 4: l y.Y y L e.. r:a. :.t., s �d' J air.;t.'.... R .� ..y +t' :rl` • ::r :�' ::,i -� •:.• ,r. r..r.. t 'ic ;3 $t` •.?'.t�l-x 'b. Z4.•.,y p . i r .�� tr..+ 1. t>- rR L \r-*. '. ,,4 f f 1;. J ,�r ,u -.YS,.''+ir�..L•..Y!'.r�;. < a t "j' t t •, ,- .r_ •:,., .Y -t\ , r tir" :.7', •1 .t� SS,',r - .* Es...y a „/ 1 4S i .,St-,. ,rl ,t ..f!l.. r St. , '•.,, 'B.. J 1 t '*`• t �. c,. l �, s t . �: u� t i �; rf_n"J Y 1 t i'c r t 1' ". :'A' .t!'i t' !- ;r:`n. 71' .i x {.•=. .k, rl.j`_•J' �; '!1'_ i, ;, I 7 S ';, .a ,+ :1?' .♦>:'. St ea:3'g. �- a r..J..�. a ,:�5 t z I ,t. .i .G+ :r t. .i r i;tr, L.:.F>tP 3. i,- ,,c.Y $� o.?( >` \ ,q' ,:. ., :.v r. •,.. t -x, f. .. r5.a f. .:tr. ♦.i- 'A t, ., t.; ra:af k': t 9, y e ` .l, I) -k�)' '.L J'�1�:i• .t S. > , ''`. 1 .ty' y ;,ti., .t ^v 1 Y:' .:1' [ !. :- '( 'r N -7t -,N. i� >: n i f'SR'w.';f1 ,,, �,al I,�W r r. r.r 't "{ , v.,.•t �,_ ,, 1't-P. trl,.. M t+.r v} a+Y' r,; ry,'>4. . %:". y,: ,�/ + itt 1' '1:. 1. s n�:r t `.�?' ,! -t ''�`. .c• F. + / ,3 .ti tr: r,. r xr' ?t •,�. - pMt._. y 1 3 .• .. L + 'Y4 r .1 , 't�'i? t !,'. v I..r., �, , .I' t:: '+41 s''r w'rllt_- \y •a,:.C' t)S •'4 'r� ` 1': I.' t ,' + l + t!. t t. } �.'. 'j S„ f :MS 1.. t' <'+� '`•'17 :r t ,, "f �. + .t, tt.,',.5, .,` qfi J 'ire ' .t,;r 4 :A5 °.14i ii1 ? S r A t y1. •R } .J%')t '.Pr '.1 Kf y ,: .r %f•• i ✓,. 't :•.:3, C . /. a„✓ f •S'„n`r X l' , 7. ,-}I. ..1• Jr. , t•a t +-i'is t...tr, y. >{i. L, �.-+ .jl. r 't^' f. r t:ftY ;I 4 a' r it ti. e s �. 3 '' r•, , ;Y.tf• t. r( r .:�.. i. r : t ,.r.,: t r' n'r .,I.'43 t 37� (.. - a J. -t ) ;i!fa's,, " �, r J T +.,i - 7 r '• ' .t. �� r i�:r!'': :� i:,• I ,_ y.H!'•� ti T:ti. r. - - �f r 7;.',y e. 2 I .r ,,,;.- lr.r-) �:a! :\..'•f i 1= 'rl ?::,:f4 '3,`rft -'ll' )•. c f i; t�.' .w. '.< "t r1 ro. ,t �+.1 t �' > 4 »'-'!� f. „r t.. ; Y 1 r' '. { .r.i .G• j T �J f r ..r 1 t. ✓ t t;.. , Y y i. + yl:+Jta (' I:.A h•,rt' s - 5't Wi y 1 ,•t.. t ! j. _ l r - J 7 «J r� -7 .Y-/ 4 (:a.; 1' r.i ..r: ,a !. c:. 4 f- .f, t d - S.- ( iJ. :r• S +f i�- i q ;t. e 9 , :i :rr y. '.< .7 f .i r i r 11 ta`'tr 1' �, l _ 4 , f. / -11 .�. .v f, .k t L ,i r �, 3. 1 , 1 G. v S. '�• J } .Y.' i YM1 , _ ;: t :(ti o'y. rJ -R�• .' - r .Y•� .,q`s S.i �j -r`,J t r « t r J j .7�. C ♦ "v Y at Yi } :..r r:{. �„ \ :t , . r''i. .. t. !. . A f.G- �y.,J t f ,1 r , ;;J �� -0. - �f' / $1.�1, t' .tw Y J `,.' '1 1 ,..` t a' 11 ( '1:. 1-, i I t' S .,- J: 1 p"-;):SY .., qn J t,, ' 3 %1 r.'. t ; .;�„\>)'� .f. 'S 1., )' f .,.. u `'+ w j .1 - i .'c " ;,P t;' .fit t J- t 1 r �.1. a 'i .: in , 1.^• 1 v.'.s. r ^r _, l r , i t T 7 t .rJ. a •,a: \ -.,. i. \ i6.)• ;r .a• . r^' t 7 1 s I,,' 1° r ' r •!, ,+,° t r t ..�- 7._ s F� )< ins l' 1 t f. + •.�' t +,.' \t s i;,_, ' r 1 �;i' t i' a-.r rt 1r / -r.,:D rf (. <r i 1 <I:`i t ♦ t + 1 'J +i.1:'. 'r.i' .., t nl. � .. 1r t :�: 1� i ,'(t l is.:i 1, + r .'7. t r.0 t -/`• J . i }} .7> ..ram •( t't' r. d.lr :F'. r. l,.,. •,. .( ? 1.,4_�eit �. r .& 'ttf a .,t 1.a ,t. 1 a t 'j + hk;�`'yyy�,1 r?,. t l..t •.' , ,+ .}_ I♦, .t1 v �j,. v: �.:•i r <Y ..y t. .r ' �ti �0 t ( '(t '�� .i,. `f:, '(.. ' S T c.it + �_� f 't- �. Q..V. t Jot i 4.1' Q•: r 1.: r4 ^ '1"'. it r.Jp J, 'I I ''Y :!� t. '.j '-.t)•l •,t t• .7,:• )' ; S .t. �jf. r:a t�"t)e ' `f -ji !. Yr. J �i f •/.• ti i. «a a -•x. I r' 'r. r �rs r. ,. i t,. "" ^f .;1, .:w.- � .rt +:' ) i - r` .gip'+ r (0 �. o- :.v;: a .7�•+.'. t :Ss `< r.or -�: i ', v -e.,' c ♦; t t. r.7, :1 �a r •S1:: to ,' .S ./J. 1.-�- J E _ V. '� y, r h <p 1'?�t ' y.,,,. 'r= �, .ly ii - L - \-. Yy .�• -il ! '.i A. jp -yrf.(,, .Y,(.. }•i1' 1;.. Zv a _., :* S Oct k t;{ z .�,. �,. J ,, 11, ri r.-f `fir:,It t,'t. i'r"?. t' `l .5;. ) , a,..:1. Y'at• .j. 'f;.� r-. l"t•1` ',t4' i.r a., �'- lrT_\l - _ , t C. :<r Y 1}:e-; ,ty r ',i i 7 .�.1.1id f. ): ,..4►�1 n a ,! tf r ,+ -A,S r ' 1.� et f;.. Li. (:;3 ,tj'. ..iiY:S;' ;• t, ;i• + i, ,.`. .f' It 4. �d,h. t J < , d.�yy dl r 1� f l't _\ a. ,a l i`. ,., 3',;'p .t.. �..J 3 .T ; Y,.. ir -�•'a:11 `J\ 1ii 1' •f, if ',L 1. � r 1' t -% J t..y.,+ff<� y r r'. '#,.'�:. J �I. 7�,• o..J J,. ., .t; i ;jam` r v v 1 A•Ir \•' •2. •-art �it.f f ..5:. SYJi �'d ,. , A (,' -d Y T > 1.-' �: -i. �� 1.V. •Y r•., ..A: 'P f. `.+• S �- t r.l'` 5'. i t•j 1`vttL .;r.. �' , a. `a r �Jr.r. R° 1 r Yf tr...i t5 f' ` r.,t.'�• ..SK + J ;'I„ e: , .� Yh+ s� '.,, ,' .. R. - ,1.3� r t + �:n.,, f ,:'tt .f 4, _.vr ;,:. ar' f^ •.3 e:r• s. ri. 1 (tar. i �'•' t �.f• !. S i sr "S � .ir 1 -'i .r' li, iv r. , ;.r A, (. , ,t i•S. ,:`I t {�ryJ .jl j F;. ',,.t.,.>, .."' R: 'If. a' f ��l• 4 + s' ,rN. 4' rrt..a P _ 4. I.Y t �•-�'1 r t t. i\, 5 w 't vt +�r',. t .ec ! _.� �y ° •fit, t .1'.i'. ^,1: c .� �s s. .L �.d i tt ' 'l `tv a4t. , ) 1c; ,i. Sr .N aT., -t `r..•r• t.'• .;• .`,, ..,r... {' S. tti� f� t;1 y.' �'r :�t \r�'. s, "j't f, �.yr. r, key�:: Y,. .r .r.., •g:: t r t\. ". '+. P. a •t-. , � .t ,.Z ':1. ':r•.+ •F..'�S . 1'a: 1.�a•.. -s:1 a ra:L c r a.:r 1''J i r; r..y,''i 'T ''r tf� ha tr' r..1. .t .'4. . ift,,r. •'J l•..a rr jj `., t i ;:f' ,�\ :,. a -/ c .3 t � Kt. uu r, -.< r- ';,.. ,r• ¢•7 t'!. -:+},r + ' 3.: , _ ✓,, c P't 3 J. C r r'+•. W%1. f i'j ^.- .�Y.' tx+.. r, .Kh, ih •'L }. t... :.+ t "'ro, tY.y. �� vt ,.y l ,'�.. j{.: \ , _t a ;'a u*;4:: ,-, f "k . • _-.'I:. M i r -.1 - r (rct 'i ,tr. -J,• �ey,w 3 l f. :... 4 .,4,.rid. 't( 1 ).+.4' ♦ .S ' t;>,sSr JA_rll h\t�1 1�*f. 5 IJi _.r t } 'f_.•. L' _Y. i+rh" a•' IT ., ,Mf \ H'^ 1 .r+ ' :.� Y t;t 1',' 7: 1 �,..k l^ 'Y.\ t,t t"" .f ! .y' 1 ), rr.. ti t L y.. ''w'. 't 'Y-.r.,ry. 1 't? 'S 0. Y "i. f- -�' !'r•' 7, 7,1.. ty} J 70 ti l: {.�. .,f ;( t' b r'1 f i, I" " �' ! ca'�°'n S 4` •^vr1' i, p�.0., !t: i_ tir ,; ..?? ,- .t- Y:r y;y.tr'. ,.:t. X ti. .r:..♦ !. S'r' 1.v ,fi� * .•r .S t i. t r . .1 t d ,i:. Y.. ,� .M $ •r Ytf • ! 'IS f;'' •:.^ �':a. 4."..) t+ : t e1- •+. j'.;a.,t, "tia 7r, :t'I. ,�,,,; i:J .3..'e: '9 -( . '.. s .R r.� h r r .:+ ; Imo, t t.t tz �y• 7 t 't:' j',, ,.(. ( i.. i. {; v. �;. 5 �,, tit t,t^ t .r .. ,a, 1 �a :� r, �i% . t !4 :. tr t;t r h. a *t r -r E + Y li: 11 K-t. -:Lo Y.. t:0..'Y.' S ,:.: I' .t• P F, .,,,;... ,: 2 ''.}: > ` [I l +' c; ,r: ji�:f�,• CY: r•t Y ,.•t,: (-'!'. r ,++j: ;�' r .t �,t. xr: 1it. ee t 't .t ,:Y i it :M ? ! ! i r7.f'. ��,. gip.... i. '[� •1y '( a. t. ,is� .J}t. y Y ,, --S IJ• 1', 1' :t!' !:- ;: '. _.� :,( !. f .r. -:'1,^ .,.t" ''.f -'-. -,•�a it .J• ?.. ;y.: s �>' \ .r .t.r1• I`,, r: S y. .:a,-r. 4 , i. y., ify \f I� ai. ! a. r..i Q �.r• i. J fs•C , .f. 1 '.. " r `,ra.. ..s. t,r ! a l / -r' J t ..tx:• .�-'• d + -,LJ I .,,.7 ••11•r3. xa �'� .i'j^� tt''.. { '- #..: y 1 Ni.' (/rl r { : rl. T. fp,•1ri ,r-,r^ tr. �'.4'. :Y :t... L ?.` K•, `;A "'n'.' rl,a J: 7 •-y' ): j y' }.+ I ..ra':ir L,, l)yZy t•� 1 •.' cr t :1 :t r-+ .3. [' 3 ,:�: i;tv 1 S e 6z .t: '.c 0.• 1 f. T t r ti a t ^i Jt i s b 4. 1 - / T. _4y, .Y..� .; 4 - #.,,.l 5 ' J J..it •� 'v yr. .i, t r, ..)' 'i'r t. C•Y fi t. ?,f .F. ,7� 4 .J , :,d: aK:. tr. / t i, :r ..a Py a; i .>'- .'7r. 3 {. •�' t :I.t a .� �• * :, �� -Jf '��{ ! V-. F„ �.' l;' ..L +S•' '�f.�r R,,. i" 1. �d -,•.1, :t. }} f•. ,ti ';< . ; �� , Y: 4,. G" `� `� .y-,• :'. , f:[1 -`+ l _r .:Y� i..I- }.-• > jlj " J- ,f 4 �! n{:, i•. ':tQ'r.' a .:t..J. r(:. t`.. ?.r -y *1 / t'. fn 7. �'ayt.{.� - q}r� ,r.:y-r .,(' .l r t': J ..5 ! J✓. 1.. .(r ✓. a' i.-, t7°iTr (•Z :'J .7s 1r.. ,.(' 2 ^:J. 1 I 1': 1 ! r .r. r'� 1 ,j t '"' 'v T.' r?:,i. lr� '1 ::i/ 1♦ ,\ �, ::S• .a• r' 2 J `-t + ,{+: y + ;, ,"t,, 5 ';� t �` :.F,i TYr' .t-:;, a S ..t t y ,,< `Y; t •!' Y S �,, y:,.Y .'t i( .:4....i, r...1 r.• :.1' ,e _ y s "t ( (� y }.'� .:'r .} �'`, i5 :t d i •:�4.:ret.. �tr'r^7. '{:Ll i. l_Li '�t} r:r '''• �'1 S 4` t .< +` } - , a9, :t•.:�S'.y �%�•- C•.•-A --<K Y- lr y! - 'v.Y, i� '3 .j3 , ') ji f tr•q roa:a'+Y1.•.}• t a. ( .. Jn- 3 ;.t 1 5 S .f '', •.1.�j>L.L`":t 't"+ 'l'.:t ), 7t`3 :+'+ -S,,.SF. yi .? r -f I - a s ♦.. ! i.l., di f` k.. ..1. rt AT r ."p -:7: ;/ 1 1 ;l .t.. r- t �' t :t 'M- i.�r. ,,}} j,t T.ti<{{ :t ..� t{ '.d. l'..1. 1 .f:r ,k r. j ;.i :.to• 7: f. '�1n.. ,.y(�,fS'.>'i `�.Y rt ,.. 1. id J �Sp '±t l l: ) '.t.,, _t. .j.i 1Y: ,. 7 ;' 1t.1,) i,� W 2k,�,.-t-. .st r a. , _a, '� J , t. "K :+ �f. .1 sir 13. ) r tl, .7 l.,Ttl,•, ii,,-4 :r1, r ,f / Y +- l'' n`t+. •! '( .} r r .r,pJ.fSI:---.'f.� r';; t. _:�, y }.' 1, _J ?a s _ 2 t,{ M 1, +,:[ r,:r 't�.`.v. }} ,'•`, i '� ;.�), .L r ;„ a ,.ri Q .4, :^Y. J(: .t NT R 1' ,a. :.',j,,�p}•'J: ?L',! }'r y. rtih ,};.. 1,J,. i• r) l'+:t. 'i .r. �# r:,F'. ,tr•.9 ,:�.} r sa.. ,. ..) 4 'f., rJ11 •.�.. , t. }4�St' 4« ,.rr "I•:.7 y "l '{ f' •T' .,. +-t F.,a....5. J.,',:f•. L'i• < t :y 'i• t S '4' s. r t t 1 - ,t .,i x:L9 *} 1. id. i t %r 7 Y. 1' ..q. 7� ^l^ .• u.. si• 5 :i a(Y .J,'"• :y' .r. , yJ r.'':l b , r 1 4 ;rt i�a.9:l s :: {' :k rt f 1,,.,,: Ills 1 J?:'r- ; Y v r Fr �. "' •1 l�• ::1' J i �: It• ♦ 'L, �(. j ,r; rs\ ,y^.;h,., r:!.. +yid r •3, zr, i-.r. 1'v.1.� ,1 I t1 7 �.t \� ,,,1� )4' /•�s "jt h't:, �, -.S ;- .,S;.l / t 1 M. ..l .,J,� ,; `_. Sr S. •:y. .-T r 1'- '�-,t rJ" t� <.��T,,:• nl:'+y1.4.I ...� ..r .J. :,. 'i f F ,)'r. �, 1 1' :i•J I <t' t' 1: at'y i ,) I +- '�- ( f y�:.�' f�'}��a{: a-.r. �r • i i y'.. f?.�,,:5` J'+ i.l rt ,•.A.l 1 i , !' :r , .? ,t, Y. a _s` 4 A •10- ,X'6 _ .r ,:1 ;v•, •, 1. ,r tit, y{.'+' a 2', �.. t �`'7 r S< i-i•••'i+�fm i ':" T,ai.;Y;�1!? 'A... y t r :� r! 1-: '• ,-. i .( ,, f�:'.�i r .a 1r. i ( .�` �. f f .7 :1 h ryyy1i.•.s.. '4 �. i •-e,c 4 :w.. t :.t: `f` t s. ...L s' r: 1 •r `.1' ,1 r- rt .t•".'ppp.x,, , rt .1.1 "K PS :b J i '�.!'-� -J.. .J,' ,t1 / .j',"� ;4 t 2 ,:y t "r x- -'Y ( .Y-• f. ++��tt',''.ry`.� . ,v rr ) y'. , .�`. .r.7.j i '•( '.�.t! .n.'Z.' .J.•{/ .� 'I .4 ,ld>.,.,•�tii t .:+('' ,a�5�,,,�, r^+�.,W .):' ..1'•,. •( /i r.. :1, ri.,"t. F, ,[ iY !•, t/.J.':�.ai as' rst, t , .,.i q •�{. .�.' a.a av t. �s: ,h 11 t Y .,�• e� ',• M, T 1 _'.!, J -,J. :t ,/ -1• Y�.. Ir. ,�"'w9, ..1'' �1' nY > i r i� t„ 't ��.�. ,.t,.• •!' a n r.~ r i e,:' c. � , �,,ta4 ),i' r a, f.a ,, rs.' r a% 'tt• ,�' S ;�•p.' '1"t •-�l 'e fi t'C -r! .r' J 3 '.t . •e•F a ,7,j.'.q T,,LL -r .1'•`f:'; I ,iK--( 'a *)'ir• J ; 5•- `''-. I. ... <♦ ,. rJ., t4. •+ :r +s. - .r;af'. Y, :.•G' Y. ♦ r.• , ,..it r, ;,i y ,� t', APPENDIX A FIELD EXPLORATION The field investigation consisted of drilling and sampling one exploratory boring, to a maximum depth of approximately 39 feet. The field exploration program was completed on June 20, 1997 under the full-time observation of an HWA engineer. The boring was located approximately in the field by taping distances from known site features and plotted on the Site and Exploration Plan, Figure 2. A legend to the terms and symbols used on the exploration logs is presented on Figure A-1. A summary boring log is presented on Figure A-2. Geotechnical drilling was performed by Holocene Drilling of Pacific, Washington, under subcontract to HWA. The boring was drilled with a Mobile track-mounted drill rig advancing a 4'/<-inch I.D., continuous flight hollow stem auger. During drilling, the HWA representative recorded pertinent information including soil sample depths, stratigraphy, soil engineering characteristics, and groundwater occurrence. The stratigraphic contacts shown on the boring log represent the approximate boundaries between soil types; actual transitions may be more gradual. The soil and groundwater conditions depicted are only for the specific date and location reported, and therefore, are not necessarily representative of other locations and times. At intervals within the boring, Standard Penetration Test (SPT) sampling was performed in general accordance with ASTM D-1586 using a 2-inch outside diameter split-spoon sampler and a standard 140-pound hammer. During the test, a sample is obtained by driving the sampler'18 inches into the soil with a hammer free-falling 30 inches per stroke. The number of blows required for each 6 inches of penetration is recorded. The SPT Resistance ("N-value") of the soil is calculated as the number of blows required for the final 12 inches_ of penetration. The N-value provides a measure of the relative density of granular soils and the relative consistency of cohesive soils. Soil samples were classified in the field and representative portions were placed in air-tight plastic bags. These soil samples were then returned to our Lynnwood, Washington laboratory for further examination and testing. 8919100 A-1 HONG WEST&ASSOCIATES, INC. RELATIVE DENSITY OR CONSISTENCY VERSUS SPT N-VALUE TEST SYMBOLS COHESIONLESS SOILS COHESIVE SOILS GS Grain Size Distribution Approximate %F Percent Fines Approximate Consistency N(blows/ft) Undrained Shear CN Consolidation Density N(blows/ft) Relative Density(%) Strength Ipstl TX Triaxial Compression Very Loose 0 to 4 0 - 15 Very Soft 0 to 2 <250 UC Unconfined Compression Loose 4 to 10 15 - 35 Soft 2 to 4 250 - 500 DS Direct Shear Medium Dense 10 to 30 35 - 65 Medium Stiff 4 to 8 500 - 1000 M Resilient Modulus Dense 30 to 50 65 - 85 Stiff 8 to 15 1000 2000 pp Pocket Penetrometer Very Dense over 50 85 - 100 Very Stiff 15 to 30 2000 - 4000 Approx. Compressive Strength (tsf) Hard I over 30 >4000 TV Torvane A Approximate Shear Strength(tsf) ASTM SOIL CLASSIFICATION SYSTEM C8R California Bearing Ratio MAJOR DIVISIONS GROUP DESCRIPTIONS MD Moisture/Density Relationship PID Photoionization Device Reading Gravel and A o GW Well-graded GRAVEL AL Atterberg Limits: PL Plastic Limit Coarse Clean Gravel LL Liquid Limit Gravelly Soils (little or no fines) Grained (I C]P Poorfy-graded GRAVEL Soils More than SAMPLE TYPE SYMBOLS 50%of Coarse Gravel with , EI GI\/I Silty GRAVEL Fraction Retained Fries(appreciable0- 1 ® 2.0" OD Split Spoon (SPT) on No.4 Sieve amount of fines) GC Clayey GRAVEL (140 lb.hammer with 30 in.drop) Sand and Clean Sand SW Well-graded SAND I Shelby Tube Sandy Soils (little or no fines) a 3.0" OD Split Spoon with Brass Rings More than _ Sp Poorly-graded SAND 50%Retained 50%or More O Small Bag Sample on No. of Coarse Sand with .�. .I SM Silty SAND 200 Sieve Fraction Passing Fines(appreciable '11 Large Bag (Bulk)Sample �L.JJ Size on No.4 Sieve amount of fines) Sir Clayey SAND i Core Run ll ML SILT Fine Silt Non-standard Penetration Test Grained and Liquid Limy with split s sampler) Less than 50% / CL Lean CLAY ( p spoon sam P Soils Clay _ OL I organic SILT/Organic CLAY COMPONENT PROPORTIONS MH Elastic SILT 50%or More Silt Liquid Limo DESCRIPTIVE TERMS RANGE OF PROPORTION Passing and 50%or More CH Fat CLAY Trace 0 - 5% No.200 Sieve Clay Few 5 - 10% ij/ OH Organic SILT/Organic CLAY Little 15 - 25% Size - Some 30 - 45% Highly Organic Soils PT ii PEAT Mostly 50 100% COMPONENT DEFINITIONS GROUNDWATER WELL COMPLETIONS Locking Well Security Casing COMPONENT SIZE RANGE Well Cap Boulders Larger than 12 in Concrete Seal Cobbles 3 in to-b2in Well Casing Gravel 3.in to No 4 14.5mm) Bentonite Seal Coarse gravel 3 in to 3/4 in Fine gravel 3/4 in to No 4(4.5mm) Q Groundwater Level (measured at Sand No.4(4.5 mm)to No.200(0.074 mml time of drilling) Coarse sand No.4(4.5 mml to No. f0(2.0 mm) = Groundwater Level (measured in Medium sand No. 10(2.0 mm)to No.40(0.42 mml well after water level stabilized) Fine send No.40(0.42 mm)to No. 200(0.074 mm) Slotted Well Casing Silt and Clay Smaller than No.200 10.074mm) Sand Backfill NOTES: Soil classifications presented on exploration logs are based on visual and laboratory observation in general accordance with ASTM D 2487 and ASTM D 2488. Soil descriptions MOISTURE CONTENT are presented in the following general order: DRY Absence of moisture,dusty, Density/consisrency, color,modifier(if any)GROUP NAME,additions to group name(if any),moisture content. dry to the touch. Proportion,gradation,and angularity of constituents,additional comments. (GEOLOGIC INTERPRETA TIONJ MOIST Damp but no visible water. Please refer to the discussion in the report text as well as the exploration logs for a more WET Visible free water,usually complete description of subsurface conditions, soil is below water table. LEGEND OF TERMS AND YL"I Olympic Pipeline Culvert Replacement SYMBOLS USED ON +IONGWEST Renton, Washington EXPLORATION LOGS & ASSOCIATES, INC. PROJECT NO.: 89 1 9-100 FIGURE: A-1 LEGEND 89191 7/8/97 DRILLING COMPANY: Holocene LOCATION: See Figure 2 DRILLING METHOD: Track Mounted Mobile, 4-1/4'ID HSA DATE COMPLETED: 6/20/97 SURFACE ELEVATION: 16 t Feet LOGGED BY: David Sowers W V— cc LU w Q s rn Standard Penetration Resistance CL -j Z N w 3 (140 lb. weight,30'drop) m of N J w �W Z ♦ Blows per foot s a- o_ w O a Zc O w a in Q DESCRIPTION Q Q u, v) v) a_ O O 0 10 20 30 40 50 0 0 SP Loose,dark brown to dark reddish brown, SM poorly graded SAND with silt,moist. (FILL) S-1 1-2-3 Interbeds of silt and clay with trace organics ML Very soft to soft,dark gray,SILT with fine sand, wet. (ALLUVIUM) S-2 1-1-2 ♦ Interbeds of fine to medium sand. ................. ......'...... ......E...... .....:.... _ . ... ........ 10 10— E : : ---- ------ - -------- - -- �S-3 1/12'-1 4! SP Very loose,dark gray,poorly graded fine to 5 medium SAND, wet. ...... ............ ............_...... . _ . . _ .. 15 ML Very stiff,very dark gray sandy SILT, wet. Fine sand. S4 6-11-8 GS ............ .....'......_ 20 20 SM Loose, dark grayish brown, silty SAND, wet Fine to medium sand. S5 3-3-3 GS 25 25 SP Medium dense, dark grayish brown, poorly graded SAND, wet.Trace silt. Fine to coarse : sand. S6 4-10-12 ...... ............ ............._ . ......_...... _ ..- 0 30 3 •` A S7 7-7-7 _............ ......6......_...... _ _...... 35 35 ♦ S8 4-11-11 Bottom of boring at 39 feet. _ -40 40 0 20 40 60 80 100 Water Content (°6i Plastic Limit Liquid Limit Natural Water Content 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. BORING: BH-1 ff",1 Olympic Pipeline Culvert Replacement floNGWES°T Renton, Washington PAGE: 1 of 2 & ASS 0 C I AT E S, INC. PROJECT NO.: 8919-1 OO FIGURE: A-2 BORING 89191 7/9/97