Loading...
HomeMy WebLinkAboutGeoTech Report BNSF Crossings - Auburn- Final.pdf________________________________________________ 3213 Eastlake Avenue East, Ste B Seattle, WA 98102 Tel (206) 262-0370 Geotechnical & Earthquake Engineering Consultants September 5, 2014 Project No. 13-197 Mr. Randy Raymond, P.E. Parametrix 1019 39th Avenue SE, Suite 100 Puyallup, Washington 98374 Subject: Geotechnical Engineering Report BNSF ST2 Track Improvement Project Auburn, Washington Parametrix Project No. 216-1931-023 Dear Mr. Raymond, As requested, PanGEO, Inc. completed a geotechnical engineering study to support the design and installation of utility casings in the Burlington Northern Santa Fe (BNSF) right-of-way in Auburn, Washington. It is our understanding that the casings will be installed using trenchless methods. The results of our study and our recommendations are summarized in the attached report. Based on the results of our subsurface exploration program, the utility casing alignments are expected to encounter loose to soft alluvial deposits and a shallow groundwater table. We anticipate the excavation for the jacking and receiving pits can be shored using sheet piles or trench boxes and steel sheets, depending on the contractor’s configurations. Dewatering can likely be accomplished using sumps and pumps or well points. We appreciate the opportunity to assist you with this project. We are available to meet to discuss our findings at your convenience. Sincerely, Siew L. Tan, P.E. Principal Geotechnical Engineer i TABLE OF CONTENTS 1.0 INTRODUCTION................................................................................................................... 1 2.0 SITE AND PROJECT DESCRIPTION ............................................................................... 1 3.0 SUBSURFACE EXPLORATIONS ....................................................................................... 2 4.0 LABORATORY TESTING ................................................................................................... 3 5.0 EXISTING PAVEMENT SECTIONS .................................................................................. 3 6.0 SUBSURFACE CONDITIONS ............................................................................................. 4 6.1 SITE GEOLOGY AND SOILS ..................................................................................................... 4 6.2 GROUNDWATER ..................................................................................................................... 5 7.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................ 5 7.1 PIPE JACKING ......................................................................................................................... 5 7.2 EXCAVATION SUPPORT AND SHORING ................................................................................... 7 7.3 DEWATERING ......................................................................................................................... 8 7.4 JACKING AND RECEIVING PIT SUBGRADE .............................................................................. 9 7.5 JACKING AND RECEIVING PIT BACKFILL ................................................................................ 9 7.6 SETTLEMENT MONITORING .................................................................................................... 9 8.0 LIMITATIONS ..................................................................................................................... 10 9.0 LIST OF REFERENCES ..................................................................................................... 12 LIST OF FIGURES Figure 1 Vicinity Map Figures 2A to 2D Site and Exploration Plans LIST OF APPENDICES Appendix A Summary Boring Logs Figure A-1 Terms and Symbols for Boring and Test Pit Logs Figures A-2 to A-8 Boring Logs (BH-1 to BH-7) Appendix B Photos of Select Soil Samples Figures B-1 to B-6 Appendix C Laboratory Test Results Figure C-1 Grain Size Distribution 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 1 GEOTECHNICAL ENGINEERING REPORT BNSF ST2 TRACK IMPROVEMENT PROJECT AUBURN, WASHINGTON 1.0 INTRODUCTION As requested, PanGEO completed a geotechnical engineering study to support the design and installation of utility casings in the Burlington Northern Santa Fe (BNSF) right-of-way in West Main Street, 3rd Street Northwest, 29th Street Northwest, and 37th Street Northwest in Auburn, Washington. Our work included conducting a site reconnaissance, advancing seven test borings, completing a laboratory testing program, and developing the conclusions and recommendations presented in this report. 2.0 SITE AND PROJECT DESCRIPTION The project will consist of installing utility casings in the north-south trending BNSF right-of- way at West Main Street, 3rd Street Northwest, 29th Street Northwest, and 37th Street Northwest in Auburn, Washington (see Figure 1, Vicinity Map). The new steel utility casings will range from approximately 20 to 56 inches in diameter and will accommodate City of Auburn water, sanitary sewer, and storm drain utilities. The casings will likely be installed using jack and bore construction methods. The design and placement of the casings will follow the BNSF guidelines for utility crossings, which require underground utility crossings under railroad tracks have a minimum depth of cover of 5½ feet below the base of the rail (BNSF Utility Accommodation Policy, 2011). Our understanding of the proposed casing installations at each BNSF right-of-way crossing follows: West Main Street – An approximately 100-foot long, 20-inch diameter steel casing will be installed to accommodate a new water main. The invert of the casing is anticipated to be on the order of 8 to 9 feet below grade at the jacking and receiving pits, respectively. 3rd Street Northwest – Install two approximately 100-foot long, 32-inch diameter casings to accommodate sanitary sewer and storm drain utilities. The casing inverts are anticipated to be on the order of 7½ to 8 feet below grade at the jacking and receiving pits. The existing grade between the jacking and receiving pits rises between approximately ½ to 1½ feet such that the BNSF minimum depth of cover of 5½ feet should be met. 29th Street Northwest – Extend an existing water main casing approximately 15 feet west. We understand the existing casing extends on the order of 7 to 8 feet below grade. Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 2 37th Street Northwest – Install an approximately 120-foot long, 24-inch diameter steel casing to accommodate a new water main and an approximately 90-foot long, 56-inch diameter casing to accommodate a storm drain pipe. The casing invert at the jacking and receiving pits is anticipated to be on the order of 12 to 14 feet below grade. As currently planned, the jacking pits will measure approximately 40 feet long by 10 to 12 feet wide and the receiving pits will measure approximately 10 feet square. 3.0 SUBSURFACE EXPLORATIONS Between October 3rd and 5th, 2013, seven test borings (BH-1 to BH-7) were drilled at the approximate locations shown on Figures 2A to 2D. The borings were located in the field by taping from existing site features. All of the borings were advanced to a depth of 21½ feet below the existing grade. Borings BH-1 to BH-4, and BH-7 were drilled using a limited access mini track-mounted drill rig owned and operated by Boretec1, Inc. of Bellevue, Washington. Borings BH-5 and BH-6 were drilled using a Diedrich D-50 limited access track-mounted drill rig owned and operated by Holocene Drilling, Inc. of Puyallup, Washington. Borings BH-1, BH-2, and BH-4 to BH-6 were drilled using 6-inch outside diameter augers, and BH-3 and BH-7 were drilled using 8-inch outside diameter hollow stem augers to allow for installation of groundwater monitoring wells. Soil samples were obtained from the borings at 2½- and 5-foot depth intervals in conjunction with Standard Penetration Test (SPT) sampling methods in general accordance with ASTM test method D-1586, in which the samples are obtained using a 2-inch outside diameter (OD) split- spoon sampler. The samplers were driven into the soil a distance of 18 inches using a 140-pound weight falling a distance of 30 inches. The number of blows required for each 6-inch increment of sampler penetration was recorded. The number of blows required to achieve the last 12 inches of sample penetration is defined as the SPT N-value. The N-value provides an empirical measure of the relative density of cohesionless soil, or the relative consistency of fine -grained soils. A geologist from PanGEO was present during the field exploration to observe the drilling, to assist in sampling, and to describe and document the soil samples obtained from the borings. The soil samples were described using the system outlined on Figure A-1 in Appendix A. The summary boring logs are included in Appendix A. Photographs of select soil samples are presented in Appendix B. In addition, a geologist from Sound Earth Strategies was also onsite to collect soil and groundwater samples for environmental testing while drilling BH-2 and BH-3, Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 3 which were located in 3rd Street Northwest. The results of the environmental testing will be provided by Sound Earth Strategies in a separate report. Two-inch diameter groundwater monitoring wells were installed in BH-3 and BH-7 to subsequently monitor groundwater levels. The groundwater monitoring wells will need to be decommissioned per the Washington State Department of Ecology’s standards prior to or during construction. 4.0 LABORATORY TESTING Laboratory tests consisting of grain size analyses were performed on representative samples obtained from the borings. The grain size analyses were performed in general accordance with ASTM D-422. Where appropriate, the test results are displayed on the summary boring logs presented in Appendix A. The laboratory test results are included in Appendix C. 5.0 EXISTING PAVEMENT SECTIONS All of the borings were drilled in the existing roadways. Our measurements of the existing pavement sections at the boring locations are provided in Table 1 below. Table 1- Existing Pavement Sections Boring Location (Street) Asphalt Thickness (inches) Concrete Thickness (inches) Crushed Rock Base Thickness (inches) BH-1 (W Main St) 6 0 Not observed BH-2 (3rd St NW) 2 6½ 6 BH-3 (3rd St NW) 15 6 0 BH-4 (29th St NW) 9 0 0 BH-5 (37th St NW) 5 0 0 BH-6 (37th St NW) 5 0 2 BH-7 (37th St NW) 2½ 0 0 Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 4 6.0 SUBSURFACE CONDITIONS 6.1 SITE GEOLOGY AND SOILS Review of the geologic map of the Auburn quadrangle indicates that the surficial geologic unit in the vicinity of this project is alluvium (Map Unit Qaw, Mullineaux, 1965). Mullineaux describes the alluvium as coarse and medium sand overlain by thin silt, clay, and peat deposits. Fill material has likely been placed over the alluvium as a result past development. The results from our subsurface exploration program indicate that the subsurface conditions at each utility crossing are relatively consistent and encountered a surficial layer of fill material overlying interlayered alluvial sand and silt. The following is a description of the soils encountered at each of the BNSF crossing locations. Please refer to the boring summary logs in Appendix A for additional details. W Main Street Crossing (BH-1) – Underlying the pavement at BH-1, 2 feet of medium dense granular fill overlying very loose silty fine sand to very soft silt and very soft peat was encountered to approximately 12½ feet below grade. Medium dense silty to relatively sand was encountered from approximately 12½ feet below grade to the maximum exploration depth of 21½ feet below grade. 3rd Street NW Crossing (BH-2 & BH-3) – Underlying the pavement at the borings in 3rd Street NW, granular fill was encountered to 5 feet below grade at BH -2 and 4½ feet below grade at BH-3. In general, the granular fill was underlain by very loose to medium dense alluvial sand with a varying fines content. However, at BH-2 a layer of very soft organic silt was encountered from approximately 6½ to 11½ feet below grade. This organic silt layer was not encountered in BH-3. 29th Street NW Crossing (BH-4) – Underlying the pavement at BH-4, loose poorly graded gravel with sand granular fill was encountered to 3 feet below grade. Underlying the granular fill, an approximately 4½-foot thick layer of very loose silty fine sand to sandy silt was encountered overlying very soft to soft silt that extended from 7½ feet to 20 feet below grade. Underlying the silt layer, loose to medium dense silty fine sand was encountered to the maximum exploration depth of 21½ feet below grade. 37th Street NW Crossing (BH-5 to BH-7) – At the 37th Street NW crossing, 5 to 6 feet of medium dense to very dense granular fill consisting of poorly graded gravel with silt and sand was encountered underlying the pavement at each of the borings. Underlying the granular fill, a 4- to 5-foot thick layer of loose to medium dense layer of silty fine sand to Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 5 poorly graded sand with silt was encountered to approximately 10 feet below grade. From 10 feet to 20 feet below grade, very soft to soft silt with occasional fine organics and fine sand seams was encountered. Underlying the silt layer, very loose to medium dense silty to clean sand was encountered to the maximum exploration depth of 21½ feet below grade. 6.2 GROUNDWATER The groundwater table was encountered in all test borings, generally between 5 and 7½ feet below grade at the time of drilling. Subsequent monitoring of the water level in the BH-3 and BH-7 groundwater monitoring wells on October 5, 2013, yielded groundwater levels of 6.9 and 6.3 feet below grade, respectively. Based on our observations of the soil samples, evidence of seasonal groundwater level highs such as iron oxide staining were typically observed ½ to 1 feet above the groundwater level encountered at the time of drilling. As such, during winter-spring months, the water level may be as shallow as about 4½ to 6 ½ feet below grade. It should be noted that groundwater elevations may vary depending on the season, local subsurface conditions, rainfalls, and other factors. Groundwater levels are normally highest during the winter and early spring. 7.0 CONCLUSIONS AND RECOMMENDATIONS 7.1 PIPE JACKING We understand that the design team plans to use pipe jacking to install the approximately 20- to 56-inch diameter, 90- to 120-foot long steel casings beneath the existing railroad tracks. Pipe jacking is a trenchless technique for installing an underground pipeline where open excavations are not feasible or appropriate. Pipe jacking installs a continuous string of casing by jacking against a reaction block in the jacking pit to advance the casing sections. The contractor should select the pipe jacking machine most suitable for the subsurface conditions anticipated. To assist the pipe jacking contractor in the selection of installation equipment for this project, photos of the soil samples from the proposed casing alignment elevation are included in Appendix B. The casing inverts are anticipated to be in the range of 7½ to 14 feet below grade at the jacking and receiving pits. It appears that the minimum 5½-foot cover between the casings and railroad tracks will be maintained at all locations. Based on the borings drilled at the BNSF crossings, the pipes will be jacked through very loose to loose silty to relatively clean fine sand and very Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 6 soft to soft silt (alluvium). Wood and peat lenses may be present within the alluvium. Seasonal groundwater fluctuations are anticipated to be in the range of about 4½ to 6½ feet below grade during the winter-spring months; groundwater level in the summer months may be approximately a foot lower. Based on the subsurface conditions observed in the test borings, it is our opinion that pipe jacking should be feasible. Based on the anticipated casing invert depths, the jacking and receiving pits will likely be less than 10 feet deep at the West Main Street and 3rd Street NW crossings, and the jacking and receiving pits at the 37th Street NW crossing will likely be on the order of 14 to 16 feet deep. The design of temporary shoring systems, in addition to determining the required size and depth of the jacking pits, should be the responsibility of the contractor. In addition, the contractor should determine the number and capacity of jacks required, based on anticipated soil types, pipe size, and jacking distance. The typical construction sequence for pipe jacking begins with excavation of pits on each end of the jacked section, and construction of temporary shoring for the pit walls. Temporary shoring considerations are discussed in Section 7.2 of this report. A steel or wood jacking abutment is then installed against the far wall of the jacking pit, followed by the installation of the hydraulic jacks and a jacking frame. Once the jacking pit has been prepared, the first section of pipe is attached to the rear of a tunneling shield, lowered into the pit, positioned on the jacking frame, and jacked forward. Excavation is performed by advancing the pipe casing and then removing the material from within the jacked section of pipe. The succeeding section of pipe is then lowered between the jacks and the lead pipe and jacked forward. The excavation, soil removal, pipe insertion, and jacking sequence is repeated until the lead section of pipe enters the receiving pit. The contractor should anticipate the need for dewatering, as discussed in Section 7.3. During construction, the groundwater level should be lowered to at least 2 feet below the bottom of the jacking and receiving pits. Dewatering may also be needed along the pipe alignments, to prevent blowouts in the casings due to excessive hydrostatic pressure. We recommend that the contract documents require the contractor to submit a dewatering plan prior to construction, for review and approval by the project engineer. Additional recommendations relative to dewatering can be made following observation of the jacking pit excavations. Bentonite slurry/synthetic polymers may be pumped between the tunneling shield and the outside of the pipe to reduce frictional resistance if approved by BNSF. BNSF does not permit the use of water under pressure jetting or puddling to facilitate jacking operations. Once the jacking Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 7 operation begins, the operation should be as continuous as possible, thereby reducing the tendency of the casing to “set” when forward motion is interrupted. After the casings have been jacked into their final positions, any voids created outside of the casing should be filled with a pumpable grout. Per BNSF, all voids or abandoned holes caused by jacking are to be filled by pressure grouting. The grout material should be sand cement slurry with a minimum of two (2) sacks of cement per cubic yard and a minimum of water to assure satisfactory placement (Part 3 , Section C.5, Casing and Pipeline Installation, BNSF Utility Accommodation Policy). 7.2 EXCAVATION SUPPORT AND SHORING It is the contractor’s responsibility to maintain safe working conditions, including temporary excavation stability. All excavations in excess of 4 feet in depth should be sloped in accordance with Washington Administrative Code (WAC) 296-155, or be shored. Given the loose/soft subsurface conditions, shallow groundwater table, and the lack of adequate space for temporary excavation slopes, excavation shoring will be needed. ‘Running sand’ conditions could be present when excavating below the groundwater level. As a result, groundwater should be properly drawn down during construction. General dewatering considerations are discussed in this report. Provided that the groundwater level is effectively drawn down to at least 2 feet below the bottom of the excavation, excavation shoring such as trench boxes and/or steel plates with hydraulic braces are considered feasible for the proposed project. Other excavation support/shoring methods, including temporary soldier piles with timber or steel plate lagging or sheet piles, may also be used. An added advantage of using steel sheet piles is their ability to partially cut off the groundwater flow into the excavation, which could potentially reduce dewatering efforts, and limit the area of disturbance and sloughing outside of the excavation areas. All excavations should be conducted in accordance with all applicable federal, state, and other local safety requirements. As a minimum, we recommend that all shoring systems for this project be designed using the geotechnical parameters presented below. The following pressures are expressed in equivalent fluid pressure: Active earth pressure: 35 pcf above groundwater table 80 pcf below groundwater table Allowable Passive Pressure: 200 pcf in alluvial deposits Where appropriate, a uniform lateral pressure of 80 psf should be used to account for a traffic surcharge. Lateral loads due to construction equipment traffic or sloping ground conditions Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 8 adjacent to the excavations should also be added to the recommended earth pressures for design purposes. The adequacy and safety of the shoring installation should be made the sole responsibility of the contractor. A qualified geotechnical engineer/shoring designer should be retained by the contractor to design and evaluate the shoring system used. The excavation support and shoring system used must comply with all applicable safety requirements. During construction, the ground adjacent to excavations should be monitored for cracks or dips and other indications of movements and possible sloughing of the excavation walls. Such monitoring is particularly critical in areas adjacent to existing structures and utilities. 7.3 DEWATERING Groundwater was encountered between 5 and 7½ feet below grade in the borings at the time of our exploration, and based on subsequent groundwater measurements in the monitoring wells installed at BH-3 and BH-7. We anticipate site excavations will likely be 10 to 16 feet deep. Therefore, the excavation of the jacking and receiving pits will likely require dewatering. The design and installation of construction dewatering is the responsibility of the contractor. However, if steel sheet piles are used as excavation shoring, it is our opinion that the dewatering can be accomplished with a series of sumps and pumps located inside the sheet pile enclosures. The collected water can then be pumped from these pits for discharge. The dewatering along the pipe alignment likely can be accomplished using a series of well points. The rate of groundwater discharge will largely depend on the groundwater level at the time of excavation, the depth of excavation, the actual soil conditions (sand vs. silt), the dewatering systems installed by the contractor, and the sequencing of the excavation. Based on our previous experience with similar soil conditions, we generally anticipate that the amount of groundwater discharge to be no more than about 5 to 10 gallons per minute at each crossing. The selection of equipment and methods of dewatering should be left up to the contractor provided they are in accordance with the recommendations in this report and the project specifications. The contractor should be aware that modifications to the dewatering system may be required during construction depending on the conditions encountered. The dewatering method selected should have minimal impact on the groundwater level surrounding the proposed excavations. Grain size analyses were conducted on select alluvial soil samples. The results of the analyses are contained in Appendix C. In addition, photos of select soil samples are included in Appendix Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 9 B of this report. The contractor may use the information from the boring logs, laboratory test results, and the photos to develop a dewatering program for this project. Lowering of groundwater in fine-grained soils such as silt and clay can often result in ground subsidence. The alluvial soils encountered in our borings vary from silt to silty sand (see Figure C-1 for grain size analysis results). As a result, construction dewatering will need to be designed and executed to minimize the potential for off-site impacts. It is our opinion that the use of widely-spaced deep watering wells, which has a relatively large radius of influence, is not appropriate for this project. 7.4 JACKING AND RECEIVING PIT SUBGRADE We anticipate that, even with proper dewatering effort, the bottom of the jacking and receiving pits are likely to be wet and potentially unstable. Based on the conditions encountered at our boring locations, very soft silt, organic silt, or peat, or loose to medium dense silty sand is anticipated to be encountered at the bottom of the jacking and receiving pits. To provide a working surface at the bottom of the jacking and receiving pits, the contractor should consider overexcavating at least 1 foot and backfilling with railroad ballast or crushed rock. In addition, the use of a geotextile separator fabric such as Mirafi 500X placed at the bottom of the overexcavation may also be considered. 7.5 JACKING AND RECEIVING PIT BACKFILL Crushed rock or Gravel Borrow (WSDOT 9-03.14(1)) should be used to backfill the jacking and receiving pits. The backfill should be compacted to 95% of the materials maximum dry density in accordance with ASTM D1557. Because the pits will likely extend below the groundwater table, controlled density fill (CDF) may be used to backfill to the groundwater table elevation and the remainder of the excavation be backfilled with crushed rock or WSDOT Gravel Borrow. The procedure to achieve proper density of a compacted fill depends on the size and type of compacting equipment, soil moisture content, the number of passes, thickness of the layer being compacted, the presence of groundwater, and certain soil properties. In areas where the use of heavy equipment may be restricted, smaller equipment can be used, but the soil must be placed in thin enough layers to achieve the required relative compaction. 7.6 SETTLEMENT MONITORING Rail elevations over the work area must be monitored at intervals prescribed by BNSF to detect any track movement. Movements of over one-quarter (1/4) inch vertically shall be immediately Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 10 reported to the BNSF Roadmaster. Due to the danger to rail traffic that is caused by only small amounts of track movement, BNSF forces may have to be called out to surface the track several times (from BNSF Utility Accommodation Policy). As a result, baseline monitoring points should be established in the vicinity of the casing alignment prior to any construction activities. As a general guideline, we suggest the monitoring points be spaced on an approximately 10 foot by 10 foot grid and the points should extend about 10 feet perpendicular to both sides of the casing alignment. The monitoring points should be established both on the tracks and on the ground surface between the tracks. The elevations of the monitoring points should be checked daily with an optical survey during casing installation. The volume of soil removal should be continuously monitored during installation. The actual volume of the removed soils should be estimated and compared to its theoretical volume as an indication of excessive soil removal and ground loss. If appreciable loss of soil occurs during the casing installation, the voids shall be grouted promptly. 8.0 LIMITATIONS We have prepared this report for Parametrix and the project design team. Recommendations contained in this report are based on a site reconnaissance, a subsurface exploration program, review of pertinent subsurface information, and our understanding of the project. The study was performed using a mutually agreed-upon scope of work. Variations in soil conditions may exist between the locations of the explorations and the actual conditions underlying the site. The nature and extent of soil variations may not be evident until construction occurs. If any soil conditions are encountered at the site that are different from those described in this report, we should be notified immediately to review the applicability of our recommendations. Additionally, we should also be notified to review the applicability of our recommendations if there are any changes in the project scope. The scope of our work does not include services related to construction safety precautions. Our recommendations are not intended to direct the contractors’ methods, techniques, sequences or procedures, except as specifically described in our report for consideration in design. Additionally, the scope of our work specifically excludes the assessment of environmental characteristics, particularly those involving hazardous substances. This report has been prepared for planning and design purposes for specific application to the proposed project in accordance with the generally accepted standards of local practice at the time this report was written. No warranty, express or implied, is made. Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 11 This report may be used only by the client and for the purposes stated, within a reasonable time from its issuance. Land use, site conditions (both off and on-site), or other factors including advances in our understanding of applied science, may change over time and could materially affect our findings. Therefore, this report should not be relied upon after 24 months from its issuance. PanGEO should be notified if the project is delayed by more than 24 months from the date of this report so that we may review the applicability of our conclusions considering the time lapse. It is the client’s responsibility to see that all parties to this project, including the designer, contractor, subcontractors, etc., are made aware of this report in its entirety. The use of information contained in this report for bidding purposes should be done at the contractor’s option and risk. Any party other than the client who wishes to use this report shall notify PanGEO of such intended use and for permission to copy this report. Based on the intended use of the report, PanGEO may require that additional work be performed and that an updated report be reissued. Noncompliance with any of these requirements will release PanGEO from any liability resulting from the use this report. We appreciate the opportunity to be of service. Sincerely, Steven T. Swenson, L.G. Siew L. Tan, P.E. Project Geologist Principal Geotechnical Engineer Geotechnical Report BNSF ST2 Track Improvement Project, Auburn, WA September 5, 2014 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. 12 9.0 LIST OF REFERENCES Burlington Northern Santa Fe (BNSF) Engineering Services, May 18, 2011, Utility Accommodation Policy. Mullineaux, D. R., 1965, Geologic map of the Auburn quadrangle, King and Pierce Counties, Washington: U.S. Geological Survey Geologic Quadrangle Map GQ-406, 1 sheet, scale 1:24,000. WSDOT, 2012. Standard Specifications for Road, Bridge and Municipal Construction, Washington State Department of Transportation. Figure No.Project No. 13-197 BNSF ST2 Track Improvement Project Auburn, WA 1 VICINITY MAP 13 - 1 9 7 F i g 1 V i c i n i t y . g r f 1 0 / 2 2 / 1 3 ( 1 2 : 1 2 ) S T S N Not To Scale W Main St. Crossing 37th St. NW Crossing 29th St. NW Crossing 3rd St. NW Crossing 167 167 167 18 18 18 B S t N W B S t N W C S t N W 15th St NW W Main St Project No.Figure No.BNSF ST2 Track Improvment Project Auburn, WashingtonSITE AND EXPLORATION PLAN (W Main Street Crossing)13-1972A 13-197 Fig 2A Main St 10/22/13 (13:16) STS Ap p r o x i m a t e T e s t B o r i n g L o c a t i o n Le g e n d : BH - 1 Approx. Scale 1" = 20' No t e : B a s e m a p p r o v i d e d b y P a r a m e t r i x . W M a i n S t r e e t C r o s s i n g W M A I N S T R E E T BN S F R I G H T - O F - W A Y BNSF RIGHT-OF-WAY Approx. Scale 1" = 20'Project No.Figure No.BNSF ST2 Track Improvement Project Auburn, WashingtonSITE AND EXPLORATION PLAN (3rd Street NW Crossing)13-1972B 13-197 Fig 2B.grf 10/22/13 (13:17) STS Le g e n d : BH - 2 Ap p r o x i m a t e T e s t B o r i n g L o c a t i o n BH - 3 3r d S t r e e t N W C r o s s i n g 3r d S T R E E T N W BN S F R I G H T - O F - W A Y BN S F R I G H T - O F - W A Y No t e : B a s e m a p p r o v i d e d b y P a r a m e t r i x . Project No.Figure No.BNSF ST2 Track Improvement Project Auburn, WashingtonSITE AND EXPLORATION PLAN (29th Street NW Crossing)13-1972C 13-197 Fig 2C - 29th St NW.grf 10/22/13 (13:18) STS Le g e n d : BH - 4 Approx. Scale 1" = 20' Ap p r o x i m a t e T e s t B o r i n g L o c a t i o n 29 t h S t r e e t N W C r o s s i n g 29 t h S T R E E T N W BNSF RIGHT-OF-WAY BN S F R I G H T - O F - W A Y No t e : B a s e m a p p r o v i d e d b y P a r a m e t r i x . Project No.Figure No.BNSF ST2 Track Improvement Project Auburn, WashingtonSITE AND EXPLORATION PLAN (37th Street NW Crossing)13-1972D 13-197 Fig 2D - 37th St NW.grf 10/22/13 (13:19) STS Le g e n d : BH - 5 Approx. Scale 1" = 20'BH-6 BH-7 Ap p r o x i m a t e T e s t B o r i n g L o c a t i o n 37 t h S t r e e t N W C r o s s i n g BN S F R I G H T - O F - W A Y 37 t h S T R E E T N W BNSF RIGHT-OF-WAY No t e : B a s e m a p p r o v i d e d b y P a r a m e t r i x . 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. APPENDIX A SUMMARY BORING LOGS MONITORING WELL <15 15 - 35 35 - 65 65 - 85 85 - 100 GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT TEST SYMBOLS 50% or more of the coarse fraction retained on the #4 sieve. Use dual symbols (eg. GP-GM) for 5% to 12% fines. 1. Soil exploration logs contain material descriptions based on visual observation and field tests using a systemmodified from the Uniform Soil Classification System (USCS). Where necessary laboratory tests have beenconducted (as noted in the "Other Tests" column), unit descriptions may include a classification. Please refer to thediscussions in the report text for a more complete description of the subsurface conditions. 2. The graphic symbols given above are not inclusive of all symbols that may appear on the borehole logs.Other symbols may be used where field observations indicated mixed soil constituents or dual constituent materials. COMPONENT SIZE / SIEVE RANGECOMPONENT SIZE / SIEVE RANGE SYMBOLS Sample/In Situ test types and intervals Consistency Well-graded GRAVEL Poorly-graded GRAVEL Silty GRAVEL Clayey GRAVEL Well-graded SAND Poorly-graded SAND Silty SAND Clayey SAND SILT Lean SILT Organic SILT or CLAY Elastic SILT Fat CLAY Organic SILT or CLAY PEAT DESCRIPTIONS OF SOIL STRUCTURES Breaks along defined planes Fracture planes that are polished or glossy Angular soil lumps that resist breakdown Soil that is broken and mixed Less than one per foot More than one per foot Angle between bedding plane and a planenormal to core axis Very Loose Loose Med. Dense Dense Very Dense SPT N-values Approx. Undrained Shear Strength (psf) <4 4 to 10 10 to 30 30 to 50 >50 <2 2 to 4 4 to 8 8 to 15 15 to 30 >30 Layered: Laminated: Lens: Interlayered: Pocket: Homogeneous: Highly Organic Soils #4 to #10 sieve (4.5 to 2.0 mm) #10 to #40 sieve (2.0 to 0.42 mm) #40 to #200 sieve (0.42 to 0.074 mm) 0.074 to 0.002 mm <0.002 mm Silt and Clay Very Soft Soft Med. Stiff Stiff Very Stiff Hard Phone: 206.262.0370 Bottom of Boring CBR Comp Con DD DS %F GS Perm PP R SG TV TXC UCC 50%or more passing #200 sieve Groundwater Level at time of drilling (ATD)Static Groundwater Level Cement / Concrete Seal Bentonite grout / seal Silica sand backfill Slotted tip Slough <250 250 - 500 500 - 1000 1000 - 2000 2000 - 4000 >4000 RELATIVE DENSITY / CONSISTENCY Fissured: Slickensided: Blocky: Disrupted: Scattered: Numerous: BCN: COMPONENT DEFINITIONS Dry Moist Wet UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONSGROUP DESCRIPTIONS Notes: for In Situ and Laboratory Testslisted in "Other Tests" column. SPT N-values Units of material distinguished by color and/orcomposition from material units above and below Layers of soil typically 0.05 to 1mm thick, max. 1 cm Layer of soil that pinches out laterally Alternating layers of differing soil material Erratic, discontinuous deposit of limited extent Soil with uniform color and composition throughout Approx. Relative Density (%) Gravel Sand 50% or more of the coarse fraction passing the #4 sieve. Use dual symbols (eg. SP-SM) for 5% to 12% fines. MOISTURE CONTENT 2-inch OD Split Spoon, SPT (140-lb. hammer, 30" drop) 3.25-inch OD Spilt Spoon (300-lb hammer, 30" drop) Non-standard penetration test (see boring log for details) Thin wall (Shelby) tube Grab Rock core Vane Shear Dusty, dry to the touch Damp but no visible water Visible free water Figure A-1 SAND / GRAVEL California Bearing Ratio Compaction Tests Consolidation Dry Density Direct Shear Fines Content Grain Size Permeability Pocket Penetrometer R-value Specific Gravity Torvane Triaxial Compression Unconfined Compression Boulder: Cobbles: Gravel Coarse Gravel: Fine Gravel: Sand Coarse Sand: Medium Sand: Fine Sand: Silt Clay > 12 inches 3 to 12 inches 3 to 3/4 inches 3/4 inches to #4 sieve SILT / CLAY GRAVEL (<5% fines) GRAVEL (>12% fines) SAND (<5% fines) SAND (>12% fines) Liquid Limit < 50 Liquid Limit > 50 Terms and Symbols for Boring and Test Pit Logs Density LO G K E Y . G P J P A N G E O . G D T 6 / 1 9 / 0 6 GS 6 inches ASPHALT. Medium dense, dark brown, poorly graded GRAVEL with silt and sand, moist (GP-GM). (Granular Fill). Very loose, dark brown, silty fine SAND, moist to wet (SM). (Alluvium). Very soft, gray, SILT, wet. Trace fine sand. -Lenses of relatively clean black sand. Very soft, dark brown to black, PEAT, moist to wet. Occasional lenses of soft gray silt. Medium dense, black, silty SAND to poorly graded SAND with silt, wet (SM to SP-SM). Fine to medium, trace subrounded gravel, trace wood debris. -S-5: 21.5% fines. Boring terminated approximately 21.5 feet below grade. Groundwater encountered at 5 feet below grade at the time of drilling. S-1 S-2 S-3 S-4 S-5 S-6 4 1 1 1 1 2 2 1 1 1 1 1 5 6 7 5 5 8 Remarks: Boring drilled with a limited access mini tracked drill rig. Drill rig equipped with a safety hammer (cathead mechanism) for SPT. Elevation based on a topographic survey provided by Parametrix. . 0 5 10 15 20 25 The stratification lines represent approximate boundaries. The transition may be gradual. MATERIAL DESCRIPTION Figure A-2 Ot h e r T e s t s Sa m p l e N o . Completion Depth: Date Borehole Started: Date Borehole Completed: Logged By: Drilling Company: De p t h , ( f t ) BNSF ST2 Track Improvement Project 13-197 Auburn, Washington Northing: , Easting: 21.5ft 10/4/13 10/4/13 STS Boretec1 Sheet 1 of 1 Project: Job Number: Location: Coordinates: Sy m b o l Sa m p l e T y p e Bl o w s / 6 i n . 81.0ft Not Applicable HSA SPT Surface Elevation: Top of Casing Elev.: Drilling Method: Sampling Method: LOG OF TEST BORING BH-1 N-Value 0 MoistureLL 50 PL RQDRecovery 100 GS 2 inches ASPHALT. 6.5 inches CONCRETE. Dense, gray, poorly graded GRAVEL with sand, moist (GP-GM). (Crushed Rock, Road Base). Medium dense, dark brown to black, silty SAND with gravel, moist (SM). (Fill). Very loose, dark brown to black, silty fine SAND, moist to wet (SM). (Alluvium). Very soft, dark brown to gray, organic SILT, moist to wet (OL). Contains abundant lenses of peat. Very loose to medium dense, dark brown to dark gray, interlayered silty fine SAND to poorly graded SAND with silt, wet (SM to SP-SM). (Alluvium) Trace fine organics, occasional gray silt lenses with peat stringers. -S-6: 24.7% fines. -Becomes brown. Boring terminated approximately 21.5 feet below grade. Groundwater noted on drill rods at 6 feet below grade at the time of drilling. S-1 S-2 S-3 S-4 S-5 S-6 S-7 6 8 3 1 1 2 2 1 1 2 1 3 6 7 7 5 5 5 4 5 6 Remarks: Boring drilled with a limited access mini tracked drill rig. Drill rig equipped with a safety hammer (cathead mechanism) for SPT. Elevation based on a topographic survey provided by Parametrix. . 0 5 10 15 20 25 The stratification lines represent approximate boundaries. The transition may be gradual. MATERIAL DESCRIPTION Figure A-3 Ot h e r T e s t s Sa m p l e N o . Completion Depth: Date Borehole Started: Date Borehole Completed: Logged By: Drilling Company: De p t h , ( f t ) BNSF ST2 Track Improvement Project 13-197 Auburn, Washington Northing: , Easting: 21.5ft 10/3/13 10/3/13 STS Boretec1 Sheet 1 of 1 Project: Job Number: Location: Coordinates: Sy m b o l Sa m p l e T y p e Bl o w s / 6 i n . 76.0ft Not Applicable HSA SPT Surface Elevation: Top of Casing Elev.: Drilling Method: Sampling Method: LOG OF TEST BORING BH-2 N-Value 0 MoistureLL 50 PL RQDRecovery 100 GS 15 inches ASPHALT. 6 inches CONCRETE. Very dense, rusty brown to black, silty SAND with gravel, moist (SM). (Fill). -S-2 sampler bouncing on a rock. Rough drilling, auger grinding on a large cobble. Very loose, gray, silty fine SAND to sandy SILT, moist (SM to ML). (Alluvium) Tip of S-3 sample wet. Loose to medium dense, black, interlayered silty SAND to poorly graded SAND with silt, wet (SM to SP-SM). -S-4: 10.1% fines. -Gray silt seam, peat in tip of S-6 sample. Boring terminated approximately 21.5 feet below grade. Groundwater noted on drill rods at 7 feet below grade at the time of drilling. Groundwater measured at 6.94 feet below grade in 2" diameter piezometer on 10/05/2013. S-1 S-2 S-3 S-4 S-5 S-6 7 50/5.5 3 1 1 2 3 3 3 3 2 4 6 8 3 3 2 Remarks: Boring drilled with a limited access mini tracked drill rig. Drill rig equipped with a safety hammer (cathead mechanism) for SPT. Elevation based on a topographic survey provided by Parametrix. . 0 5 10 15 20 25 The stratification lines represent approximate boundaries. The transition may be gradual. MATERIAL DESCRIPTION Figure A-4 Ot h e r T e s t s Sa m p l e N o . Completion Depth: Date Borehole Started: Date Borehole Completed: Logged By: Drilling Company: De p t h , ( f t ) BNSF ST2 Track Improvement Project 13-197 Auburn, Washington Northing: , Easting: 21.5ft 10/3/13 10/4/13 STS Boretec1 Sheet 1 of 1 Project: Job Number: Location: Coordinates: Sy m b o l Sa m p l e T y p e Bl o w s / 6 i n . 78.0ft HSA SPT Surface Elevation: Top of Casing Elev.: Drilling Method: Sampling Method: LOG OF TEST BORING BH-3 N-Value 0 MoistureLL 50 PL RQDRecovery 100 In s t r u m e n t >> 9 inches ASPHALT. Loose, brown, poorly graded GRAVEL with sand, moist (GP-GM). (Fill). -Rough drilling, auger grinding on a large cobble. Very loose, brown to gray, silty fine SAND to sandy SILT, moist (SM to ML). (Alluvium). -Iron oxide staining, becomes wet at 6 feet. Very soft to soft, gray SILT, moist to wet (ML). Contains fine organics. -Sample S-4 contains lenses of silt with fine sand. -Homogenous. Loose to medium dense, gray, silty fine SAND, wet (SM). Boring terminated approximately 21.5 feet below grade. Groundwater noted on drill rods at 6 feet below grade at the time of drilling. S-1 S-2 S-3 S-4 S-5 S-6 5 2 4 3 2 1 1 1 2 1 1 2 2 2 2 3 5 5 Remarks: Boring drilled with a limited access mini tracked drill rig. Drill rig equipped with a safety hammer (cathead mechanism) for SPT. Elevation based on a topographic survey provided by Parametrix. . 0 5 10 15 20 25 The stratification lines represent approximate boundaries. The transition may be gradual. MATERIAL DESCRIPTION Figure A-5 Ot h e r T e s t s Sa m p l e N o . Completion Depth: Date Borehole Started: Date Borehole Completed: Logged By: Drilling Company: De p t h , ( f t ) BNSF ST2 Track Improvement Project 13-197 Auburn, Washington Northing: , Easting: 21.5ft 10/4/13 10/4/13 STS Boretec1 Sheet 1 of 1 Project: Job Number: Location: Coordinates: Sy m b o l Sa m p l e T y p e Bl o w s / 6 i n . 55.0ft Not Applicable HSA SPT Surface Elevation: Top of Casing Elev.: Drilling Method: Sampling Method: LOG OF TEST BORING BH-4 N-Value 0 MoistureLL 50 PL RQDRecovery 100 GS 5 inches ASPHALT. Medium dense to very dense, brown, poorly graded GRAVEL with silt and sand, moist (GP-GM). (Granular Fill). -Cobbles observed in cuttings. Medium dense, gray, silty fine SAND to poorly graded SAND with SILT, moist to wet (SM to SP-SM). (Alluvium). -Becomes wet. Very soft, gray, SILT, wet (ML). Low, plasticity, trace fine organics. -Increase in plasticity, laminated. Medium dense, black, silty SAND, wet (SM). Fine to medium. -S-6: 14.0% fines. Boring terminated approximately 21.5 feet below grade. Groundwater noted on drill rods at 7 feet below grade at the time of drilling. S-1 S-2 S-3 S-4 S-5 S-6 29 50/5 15 8 3 3 4 5 1 2 1 0 0 0 4 5 7 Remarks: Boring drilled with a Diedrich D50 limited access tracked drill rig. Drill rig equipped with an auto-hammer for SPT. Elevation based on a topographic survey provided by Parametrix. 0 5 10 15 20 25 The stratification lines represent approximate boundaries. The transition may be gradual. MATERIAL DESCRIPTION Figure A-6 Ot h e r T e s t s Sa m p l e N o . Completion Depth: Date Borehole Started: Date Borehole Completed: Logged By: Drilling Company: De p t h , ( f t ) BNSF ST2 Track Improvement Project 13-197 Auburn, Washington Northing: , Easting: 21.5ft 10/5/13 10/5/13 STS Holocene Drilling Sheet 1 of 1 Project: Job Number: Location: Coordinates: Sy m b o l Sa m p l e T y p e Bl o w s / 6 i n . 55.0ft Not Applicable HSA SPT Surface Elevation: Top of Casing Elev.: Drilling Method: Sampling Method: LOG OF TEST BORING BH-5 N-Value 0 MoistureLL 50 PL RQDRecovery 100 >> 5 inches ASPHALT over 2 inches crushed rock road base. Dense to very dense, brown, poorly graded GRAVEL with silt and sand, moist (GP-GM). (Granular Fill). -Cobbles observed in cuttings. Loose, dark gray to gray, silty fine SAND, moist to wet (SM). (Alluvium). -Becomes wet. Very soft, gray, SILT, wet (ML). Trace fine sand, trace fine organics. -Increase in plasticity. Medium dense, black, poorly graded SAND with silt, wet (SP-SM). Fine to medium. Boring terminated approximately 21.5 feet below grade. Groundwater noted on drill rods at 7.5 feet below grade at the time of drilling. S-1 S-2 S-3 S-4 S-5 S-6 45 31 32 34 26 19 2 3 2 1 0 1 1 0 0 4 4 7 Remarks: Boring drilled with a Diedrich D50 limited access tracked drill rig. Drill rig equipped with an auto-hammer for SPT. Elevation based on a topographic survey provided by Parametrix. 0 5 10 15 20 25 The stratification lines represent approximate boundaries. The transition may be gradual. MATERIAL DESCRIPTION Figure A-7 Ot h e r T e s t s Sa m p l e N o . Completion Depth: Date Borehole Started: Date Borehole Completed: Logged By: Drilling Company: De p t h , ( f t ) BNSF ST2 Track Improvement Project 13-197 Auburn, Washington Northing: , Easting: 21.5ft 10/5/13 10/5/13 STS Holocene Drilling Sheet 1 of 1 Project: Job Number: Location: Coordinates: Sy m b o l Sa m p l e T y p e Bl o w s / 6 i n . 56.0ft Not Applicable HSA SPT Surface Elevation: Top of Casing Elev.: Drilling Method: Sampling Method: LOG OF TEST BORING BH-6 N-Value 0 MoistureLL 50 PL RQDRecovery 100 GS 2.5 inches ASPHALT. Very dense, brown, poorly graded GRAVEL with silt and sand, moist (GP-GM). (Granular Fill). Loose to medium dense, dark brown to dark gray, interlayered silty fine SAND and poorly graded SAND with silt, moist to wet (SM to SP-SM). Contains fine organics, occasional gray silt seams. (Alluvium). -Iron oxide staining in tip of S-2. Very soft to soft, gray, SILT, moist to wet (ML). 2 inch thick peat lens in sample S-4, scattered fine organics. -Seams of fine sand. Very loose to loose, black, poorly graded SAND, wet (SP). Trace gravel. -S-6: 1.4% fines. Boring terminated approximately 21.5 feet below grade. Groundwater noted on drill rods at 7 feet below grade at the time of drilling. Groundwater measured at 6.3 feet below grade in 2" diameter piezometer on 10/05/2013. S-1 S-2 S-3 S-4 S-5 S-6 29 50/5 4 4 7 5 4 3 1 0 1 2 2 1 2 3 1 Remarks: Boring drilled with a limited access mini tracked drill rig. Drill rig equipped with a safety hammer (cathead mechanism) for SPT. Elevation based on a topographic survey provided by Parametrix. . 0 5 10 15 20 25 The stratification lines represent approximate boundaries. The transition may be gradual. MATERIAL DESCRIPTION Figure A-8 Ot h e r T e s t s Sa m p l e N o . Completion Depth: Date Borehole Started: Date Borehole Completed: Logged By: Drilling Company: De p t h , ( f t ) BNSF ST2 Track Improvement Project 13-197 Auburn, Washington Northing: , Easting: 21.5ft 10/3/13 10/3/13 STS Boretec1 Sheet 1 of 1 Project: Job Number: Location: Coordinates: Sy m b o l Sa m p l e T y p e Bl o w s / 6 i n . 54.5ft HSA SPT Surface Elevation: Top of Casing Elev.: Drilling Method: Sampling Method: LOG OF TEST BORING BH-7 N-Value 0 MoistureLL 50 PL RQDRecovery 100 In s t r u m e n t >> 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. APPENDIX B PHOTOS OF SELECT SOIL SAMPLES Photos of Select Soil Samples BNSF ST2 Track Improvement Project, Auburn WA Figure B-1 BH-1; S-2: 5’-6.5’ BH-1; S-3: 7.5’-9’ Photos of Select Soil Samples BNSF ST2 Track Improvement Project, Auburn WA Figure B-2 BH-2; S-2: 5’-6.5’ BH-2; S-3: 7.5’-9’ Photos of Select Soil Samples BNSF ST2 Track Improvement Project, Auburn WA Figure B-3 BH-3; S-2: 5’-6.5’ BH-3; S-3: 7.5’-9’ Photos of Select Soil Samples BNSF ST2 Track Improvement Project, Auburn WA Figure B-4 BH-5; S-3: 7.5’-9’ BH-5; S-4: 10’-11.5’ Photos of Select Soil Samples BNSF ST2 Track Improvement Project, Auburn WA Figure B-5 BH-6; S-3: 7.5’-9’ BH-6; S-4: 10’-11.5’ Photos of Select Soil Samples BNSF ST2 Track Improvement Project, Auburn WA Figure B-6 BH-7; S-3: 7.5’-9’ BH-7; S-4: 10’-11.5’ 13-197 BNSF Crossings - Auburn- Final PanGEO, Inc. APPENDIX C LABORATORY TEST RESULTS 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.1110100 Specimen Identification 1.5 16 D10 GRAIN SIZE DISTRIBUTION fine 30 200 15.0 15.0 10.0 20.0 20.0 BH-1 BH-2 BH-3 BH-5 BH-7 CuLL 3 60 4.75 9.525 19.05 4.75 38.1 8 BH-1 BH-2 BH-3 BH-5 BH-7 COBBLES SAND fine PL 20 0.187 0.168 0.327 0.235 0.978 SILTY SAND(SM) SILTY SAND(SM) POORLY GRADED SAND with SILT(SP-SM) SILTY SAND(SM) POORLY GRADED SAND(SP) NP NP NP NP NP PICc 0.0 0.8 0.8 0.0 5.5 NP NP NP NP NP D100D60 %Gravel 78.5 74.5 89.1 86.0 93.1 Specimen Identification 1/23/81 Figure C-1 coarse %Sand 6 2 coarse 1.41 0.99 4.40 5.01 21.5 24.7 10.1 14.0 1.4 SILT OR CLAY 4 404 GRAVEL %Clay 100 1403 D30 0.092 0.084 0.185 0.118 0.4340.195 @ 15.0 ft. @ 15.0 ft. @ 10.0 ft. @ 20.0 ft. @ 20.0 ft. PE R C E N T F I N E R B Y W E I G H T Classification GRAIN SIZE IN MILLIMETERS 3/4 %Silt medium 61014 NP NP NP NP NP 50 HYDROMETERU.S. SIEVE OPENING IN INCHES Figure U.S. SIEVE NUMBERS FigureProject: BNSF ST2 Track Improvement Project Job Number: 13-197 Location: Auburn, WashingtonPhone: 206.262.0370 GR A I N S I Z E 1 3 - 1 9 7 B O R I N G L O G S . G P J P A N G E O . G D T 1 0 / 2 1 / 1 3