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HomeMy WebLinkAbout3.31 Garage - VMC Geo ReportGeotechnical Engineering Services Valley Medical Center FY 2017 Proposed Parking Garage Renton, Washington for Valley Medical Center August 2, 2016 Geotechnical Engineering Services Valley Medical Center FY 2017 Proposed Parking Garage Renton, Washington for Valley Medical Center August 2, 2016 8410 154th Avenue NE Redmond, Washington 98052 425.861.6000 Table of Contents INTRODUCTION............................................................................................................................................................................... 1 PROJECT DESCRIPTION ............................................................................................................................................................... 1 FIELD EXPLORATIONS AND LABORATORY TESTING ........................................................................................................... 1 Field Explorations................................................................................................................................1 Laboratory Testing ..............................................................................................................................1 PREVIOUS SITE EVALUATIONS .................................................................................................................................................. 2 SITE CONDITIONS........................................................................................................................................................................... 2 Regional Geology ................................................................................................................................2 Surface Conditions..............................................................................................................................2 Subsurface Conditions ........................................................................................................................2 Fill…………. ....................................................................................................................................3 Glacially Consolidated Soils ...........................................................................................................3 Sandstone Bedrock.......................................................................................................................3 Groundwater Conditions ......................................................................................................................3 CONCLUSIONS AND RECOMMENDATIONS ............................................................................................................................ 3 Earthquake Engineering ......................................................................................................................4 Liquefaction .................................................................................................................................4 Lateral Spreading .........................................................................................................................4 Surface Rupture ...........................................................................................................................4 Other Seismic Hazards ..................................................................................................................4 2012 IBC Seismic Design Information ............................................................................................5 Excavations ........................................................................................................................................5 Excavation Considerations.............................................................................................................5 Temporary Cut Slopes ...................................................................................................................5 Soldier Pile and Tieback Walls .......................................................................................................6 Shallow Foundations ...........................................................................................................................9 Allowable Bearing Pressure ...........................................................................................................9 Settlement .................................................................................................................................10 Lateral Resistance ......................................................................................................................10 Construction Considerations ........................................................................................................11 Slab-on-Grade Floors .........................................................................................................................11 Subgrade Preparation .................................................................................................................11 Design Parameters .....................................................................................................................11 Below-Slab Drainage ...................................................................................................................12 Below-Grade Walls ............................................................................................................................13 Permanent Below-Grade Walls .....................................................................................................13 Other Cast-in-Place Walls.............................................................................................................13 Drainage ....................................................................................................................................14 August 2, 2016 | Page i File No. 2202-024-00 Table of Contents (continued) Earthwork.........................................................................................................................................14 Stripping, Clearing and Grubbing..................................................................................................14 Erosion and Sedimentation Control ..............................................................................................14 Subgrade Preparation .................................................................................................................15 Structural Fill ..............................................................................................................................15 Permanent Slopes ......................................................................................................................17 Pavement Recommendations ............................................................................................................17 Subgrade Preparation .................................................................................................................17 New Hot-Mix Asphalt Pavement....................................................................................................18 Recommended Additional Geotechnical Services ................................................................................18 LIMITATIONS ................................................................................................................................................................................ 18 REFERENCES ............................................................................................................................................................................... 18 LIST OF FIGURES Figure 1. Vicinity Map Figure 2. Site Plan Figure 3. Earth Pressure Diagrams – Permanent Soldier Pile & Tieback Wall Figure 4. Earth Pressure Diagram – Permanent Below Grade Walls Figure 5. Recommended Surcharge Pressure APPENDICES Appendix A. Field Explorations Figure A-1 – Key to Exploration Logs Figures A-2 through A-8 – Log of Borings Appendix B. Laboratory Testing Appendix C. Boring Logs from Previous Studies Appendix D. Ground Anchor Load Tests and Shoring Monitoring Program Appendix E. Report Limitations and Guidelines August 2, 2016 | Page ii File No. 2202-024-00 INTRODUCTION This report presents the results of GeoEngineers’ geotechnical engineering services for the Valley Medical Center (VMC) FY 2017 Parking Garage project in Renton, Washington. The site is irregular in shape and is located in the northern portion of the VMC campus at 400 South 43rd Street. The site is bordered to the west by an existing parking garage, to the north by a steep-sided ravine, to the east by medical office buildings and to the south by a VMC campus access road off Talbot Road South. The site is shown relative to surrounding physical features on the Vicinity Map, Figure 1 and the Site Plan, Figure 2. The purpose of this report is to provide geotechnical engineering conclusions and recommendations for the design and construction of the planned parking garage development. GeoEngineers’ geotechnical engineering services have been completed in general accordance with our signed agreement executed on March 21, 2016. PROJECT DESCRIPTION GeoEngineers understands that the Parking Garage project will be an expansion of the existing parking garage at the north end of the campus. The new garage will be directly east of the existing garage and will be up to eight levels above-grade. The lowest levels of the garage will be partially below grade adjacent to the existing garage and may require excavations up to 25 feet below grade along the north end of the garage. Additionally, based on our understanding of the project temporary and/or permanent soldier pile retaining walls will be used to support some of the excavations. We also understand that the permanent wall, where present, will be offset 3 to 5 feet from the new garage structure. Variable soil conditions are present at the anticipated foundation elevation; therefore, shallow foundations bearing on native or structural fill are anticipated for foundation support. FIELD EXPLORATIONS AND LABORATORY TESTING Field Explorations The subsurface conditions at the site were evaluated by drilling seven borings, GEI-1 through GEI-7, to depths of approximately 15½ to 35¾ feet below existing site grades. The approximate locations of the explorations are shown on the Site Plan, Figure 2. Descriptions of the field exploration program and the boring logs are presented in Appendix A. Laboratory Testing Soil samples were obtained during drilling and were taken to GeoEngineers’ laboratory for further evaluation. Selected samples were tested for the determination of fines content and grain-size distribution (sieve analysis). A description of the laboratory testing and the test results are presented in Appendix B. August 2, 2016 | Page 1 File No. 2202-024-00 PREVIOUS SITE EVALUATIONS In addition to the explorations completed as part of this evaluation, the logs of selected explorations from previous site evaluations in the project vicinity were reviewed. The logs of explorations from previous projects referenced for this study are presented in Appendix C. SITE CONDITIONS Regional Geology Published geologic information for the project vicinity includes a geologic map of the Renton Quadrangle (Mullineaux 1965). The geologic map of the project area identifies subsurface soils to consist primarily of glacial till deposits of the Vashon Drift. Also mapped in the area are Renton Formation sandstone with interbeds of siltstone, claystone and coal. Glacial till typically consists of a heterogeneous mixture of sand, gravel, cobbles and occasional boulders in a silt and clay matrix that was deposited beneath a glacier. Because glacial till has been overridden by thousands of feet of ice, it is typically dense to very dense. Renton Formation sandstone consists of irregularly cemented arkosic sandstone, mudstone and shale and locally contains coal deposits. Geologic map notes maximum thicknesses of approximately 2,500 feet. Subsurface soils encountered in our explorations are consistent with the geologic mapping. Specific details of subsurface conditions encountered in the field explorations are presented in the “Subsurface Conditions” section below. Surface Conditions The site is currently occupied by asphalt and gravel surface parking, landscaped parking islands and several mature coniferous and deciduous trees. The site steps down from east to west, with a total change in elevation of approximately 20 feet. Generally, the site appears to be clear of public utilities. The utilities on site consist of private stormwater, power for the parking lot lights, and sewer services. Subsurface Conditions The subsurface conditions at the site were evaluated by completing seven geotechnical borings (GEI-1 through GEI-7) completed for the current study, and reviewing logs of explorations completed by others immediately adjacent to the project site. The approximate locations of the explorations in the site vicinity are shown on the Site Plan, Figure 2. The geologic units encountered in the explorations consist of fill, glacially consolidated soils and sandstone bedrock. Each of these units is described below in order of deposition starting with the most recent. August 2, 2016 | Page 2 File No. 2202-024-00 Fill Fill was encountered below the asphalt pavement or gravel in the explorations completed for this study and previous studies. The fill typically consists of loose to dense silty sand or medium stiff to very stiff sandy silt with variable gravel content and extends to depths ranging from 3 and 14 feet below existing site grades. Glacially Consolidated Soils The glacially consolidated soils encountered below the fill consist of weathered and unweathered glacial till. The glacial till encountered consists of silty sand or sandy silt with variable gravel content. A medium dense to very dense weathered zone nearer the surface transitions to the dense to very dense unweathered glacial till below. The transition between weathered and unweathered glacial till was observed at depths ranging from approximately 5 to 12 feet below site grades. Glacial till extended approximately 22 to 24 feet below site grades in borings GEI-1, GEI-2 and GEI-5 and to the depths explored in borings GEI-3, GEI-4, GEI-6 and GEI-7. Sandstone Bedrock Sandstone bedrock (Renton Formation) was encountered below the glacially consolidated soils in borings GEI-1, GEI-2, and GEI-5 and consists of very dense cemented silty sand with occasional coal deposits. Where encountered, the Renton formation extended to the depths explored. Groundwater Conditions Perched water was encountered at various depths in borings GEI-2, GEI-3, and GEI-4. The groundwater observed in these borings was confined to wet, loose soils overlying dense to very dense soils with relatively high fines content. The perched groundwater encountered is likely associated with seasonal rainfall. Perched groundwater is expected to fluctuate as a result of season, precipitation, and other factors. CONCLUSIONS AND RECOMMENDATIONS A summary of the primary geotechnical considerations is provided below. The summary is presented for introductory purposes only and should be used in conjunction with the complete recommendations presented in this report. ■ The site is designated as Site Class C per ASCE/SEI 7-10 and the 2012 International Building Code (IBC). ■ The groundwater table is likely well below the base of the excavation. Minor seepage inflows may be expected where excavations intercept perched groundwater zones. We estimate flow rates from incidental seepage may be on the order of 5 to 10 gallons per minute (gpm). ■ Temporary excavations may be completed with open cuts or with temporary and/or permanent soldier pile and tieback walls. Soil nail walls are not recommended due to the thickness and variability of the existing fill soils. August 2, 2016 | Page 3 File No. 2202-024-00 ■ Shallow foundations may be used and shall bear on either dense to very dense glacial till and/or sandstone bedrock, on structural fill extending down to dense to very dense glacial till and/or sandstone bedrock, or on a 2-foot-thick layer of structural fill placed over the existing fill and highly weathered glacial soils:  For shallow foundations bearing directly on dense to very dense glacial till or sandstone bedrock, an allowable soil bearing pressure of 10 kips per square foot (ksf) may be used.  For shallow foundations bearing on structural fill extending down to dense to very dense glacial till or sandstone bedrock, an allowable soil bearing pressure of 6 ksf may be used.  For shallow foundations bearing on a 2-foot-thick layer of structural fill placed over the existing fill and highly weathered glacial soils, an allowable soil bearing pressure of 3 ksf may be used. ■ The majority of the on-site soils generally contain a high percentage of fines and are highly moisture-sensitive. The on-site soils may be used as structural fill during dry weather conditions only (typically June through September) provided the soils are properly moisture conditioned for compaction. Imported granular soils with a low percentage of fines should be used as structural fill during wet weather conditions and during the wet season (typically October through May). Our specific geotechnical recommendations are presented in the following sections of this report. Earthquake Engineering Liquefaction Liquefaction refers to the condition by which vibration or shaking of the ground, usually from earthquake forces, results in the development of excess pore pressures in saturated soils with subsequent loss of strength. In general, soils that are susceptible to liquefaction include very loose to medium dense, clean to silty sands that are below the water table. Our analysis indicates that the soils that underlie the proposed building area have a low risk of liquefying because of the density and gradation of these soils. Lateral Spreading Lateral spreading involves lateral displacement of large, surficial blocks of soil as the underlying soil layer liquefies. Because the buildings will bear on non-liquefiable soils, the potential for lateral spreading is considered to be low for the project site. Surface Rupture The Renton Formation has many small faults with generally low displacement (Mullineaux 1965). However, the nearest mapped fault, the Sunbeam fault is approximately ½ mile north of the site. Based on the distance to this known fault zone, and lack of other known fault zones near the site, it is our opinion that there is a low to moderate risk of surface rupture at the site. Other Seismic Hazards Due to the location of the site and the site’s topography, the risk of adverse impacts resulting from seismically induced slope instability and differential settlement is considered to be low. August 2, 2016 | Page 4 File No. 2202-024-00 2012 IBC Seismic Design Information The following 2012 IBC parameters for site class, short period spectral response acceleration (SS), 1-second period spectral response acceleration (S1) and seismic coefficients (FA and FV) are appropriate for the project site. TABLE 1. 2012 IBC SEISMIC DESIGN PARAMETERS 2012 IBC Parameter Recommended Value Site Class C Short Period Spectral Response Acceleration, SS (percent g) 140.1 1-Second Period Spectral Response Acceleration, S1 (percent g) 52.2 Seismic Coefficient, FA 1.0 Seismic Coefficient, FV 1.3 Excavations We understand that the planned building will have up to two below-grade levels and that the excavations may extend up to 25 feet below site grades. Temporary cut slopes may be used for shallow excavations or where there is sufficient space to complete cut slopes. Temporary shoring may also be used for excavations where there is not sufficient space for cut slopes. The following sections provide geotechnical design and construction recommendations for temporary cut slopes and temporary shoring, specifically soldier pile and tieback walls. We understand that permanent soldier pile walls with tiebacks may be used along the northern portion of the new garage. We provide geotechnical recommendations for permanent soldier pile walls with tiebacks below. Excavation Considerations The site soils may be excavated with conventional excavation equipment, such as trackhoes or dozers. It may be necessary to rip the glacially consolidated soils locally to facilitate excavation. The contractor should be prepared for occasional cobbles and boulders in the site soils. Likewise, the surficial fill may contain foundation elements and/or utilities from previous site development, debris, rubble and/or cobbles and boulders. We recommend that procedures be identified in the project specifications for measurement and payment of work associated with obstructions. Temporary Cut Slopes Temporary slopes may be used around the site where space allows, to facilitate early installation of shoring, or in the transition between levels at the base of the excavation. We recommend that temporary slopes constructed in the fill be inclined at 1½H:1V (horizontal to vertical) and that temporary slopes in the glacially consolidated soils be inclined at 1H:1V. Flatter slopes may be necessary if seepage is present on the face of the cut slopes or if localized sloughing occurs. For open cuts at the site, we recommend that: ■ no traffic, construction equipment, stockpiles or building supplies be allowed at the top of the cut slopes within a distance of at least 5 feet from the top of the cut; ■ exposed soil along the slope be protected from surface erosion by using waterproof tarps or plastic sheeting; August 2, 2016 | Page 5 File No. 2202-024-00 ■ construction activities be scheduled so that the length of time the temporary cut is left open is reduced to the extent practicable; ■ erosion control measures be implemented as appropriate such that runoff from the site is reduced to the extent practicable; ■ surface water be diverted away from the slope; and ■ the general condition of the slopes be observed periodically by the geotechnical engineer to confirm adequate stability. Because the contractor has control of the construction operations, the contractor should be made responsible for the stability of cut slopes, as well as the safety of the excavations. Shoring and temporary slopes must conform to applicable local, state and federal safety regulations. Soldier Pile and Tieback Walls Based on the subsurface information obtained from the borings, we recommend temporary or permanent cantilever soldier pile walls or soldier pile with tieback walls be used for excavation support where temporary slopes are not possible. Soil nail walls are not recommended due to the thickness and variability of the existing fill soils. We provide geotechnical design and construction recommendations for cantilever soldier pile and soldier pile with tiebacks walls below. Soldier pile walls consist of steel beams that are concreted into drilled vertical holes located along the wall alignment, typically about 8 feet on center. After excavation to specified elevations, tiebacks are installed, if necessary. Once the tiebacks are installed, the pullout capacity of each tieback is tested, and the tieback is locked off to the soldier pile at or near the design tieback load. Tiebacks typically consist of steel strands that are installed into pre-drilled holes and then either tremie or pressure grouted. Timber lagging is typically installed behind the flanges of the steel beams to retain the soil located between the soldier piles. Geotechnical design recommendations for each of these components of the soldier pile and tieback wall system are presented in the following sections. Soldier Piles We recommend that temporary and permanent soldier pile walls be designed using the earth pressure diagrams presented in Figure 3. The earth pressures presented in Figure 3 are for full-height cantilever soldier pile walls and soldier pile walls with single or multiple levels of tiebacks, and the pressures represent the estimated loads that will be applied to the wall system for various wall heights. Seismic earth pressures are included in Figure 3 for design of permanent walls. The seismic earth pressure does not need to be included in the design of temporary walls. The earth pressures presented in Figure 3 include the loading from traffic surcharge. Other surcharge loads, such as buildings, cranes, construction equipment or construction staging areas, should be considered on a case-by-case basis in accordance with the recommendations presented in Figure 5. We recommend that the embedded portion of the soldier piles be at least 2 feet in diameter and extend a minimum distance of 10 feet below the base of the excavation to resist “kick-out.” The axial capacity of the soldier piles must resist the downward component of the anchor loads and other vertical loads, as August 2, 2016 | Page 6 File No. 2202-024-00 appropriate. We recommend using an allowable end bearing value of 40 ksf for piles supported on the glacially consolidated soils. The allowable end bearing value should be applied to the base area of the drilled hole into which the soldier pile is concreted. This value includes a factor of safety of about 2.5. The allowable end bearing value assumes that the shaft bottom is cleaned out immediately prior to concrete placement. If necessary, an allowable pile skin friction of 1.0 ksf may be used on the embedded portion of the soldier piles to resist the vertical loads. For permanent walls, the exposed portion of the solider pile (e.g. if exposed to weather) should be painted with a coat of inorganic zinc primer to reduce the risk of corrosion. Additionally, structural concrete should be used for the embedded portion of the soldier pile. Temporary Lagging We recommend that the temporary timber lagging be sized using the procedures outlined in the Federal Highway Administration’s Geotechnical Engineering Circular No. 4. The site soils are best described as competent soils. Table 2 presents recommend temporary lagging thicknesses (roughcut) as a function of soldier pile clear span and depth. TABLE 2. RECOMMENDED TIMBER LAGGING THICKNESS Depth (feet) Recommended Lagging Thickness (roughcut) for clear spans of: 5 feet 6 feet 7 feet 8 feet 9 feet 10 feet 0 to 25 2 inches 3 inches 3 inches 3 inches 4 inches 4 inches Permanent Lagging Permanent lagging may consist of timber, cast-in-place concrete or pre-cast concrete. If timber is used for permanent lagging, it must be adequately treated for protection against water and decay. We recommend that the permanent lagging be designed for a pressure equal to two-thirds the pressures depicted in Figure 3. Surcharge loading should also be considered as appropriate. The one-third pressure reduction is based on a maximum center-to-center pile spacing of 8 feet. If a wider spacing is desired, GeoEngineers should provide guidance on modifying the lagging pressures. Lagging Installation Lagging should be installed promptly after excavation, especially in areas where perched groundwater is present or where clean sand and gravel soils are present and caving soils conditions are likely. The workmanship associated with lagging installation is important for maintaining the integrity of the excavation. The space behind the lagging should be filled with soil as soon as practicable. Placement of this material will help reduce the risk of voids developing behind the wall and damage to existing improvements located behind the wall. Material used as backfill in voids located behind the lagging should not cause buildup of hydrostatic pressure behind the wall. Lean concrete is a suitable option for the use of backfill behind the walls. Lean concrete will reduce the volume of voids present behind the wall. Alternatively, lean concrete may be used for backfill behind the upper 15 to 20 feet of the excavation to limit caving and sloughing of the upper soils, with on-site soils used to backfill the voids for the remainder of the excavation. Based on our experience, August 2, 2016 | Page 7 File No. 2202-024-00 the voids between each lean concrete lift are sufficient for preventing the buildup of hydrostatic pressure behind the wall. Tiebacks Tieback anchors can be used for wall heights where cantilever soldier pile walls are not cost-effective. Tieback anchors should extend far enough behind the wall to develop anchorage beyond the “no-load” zone and within a stable soil mass, as shown on Figure 3. The anchors should be inclined downward at 15 to 25 degrees below the horizontal. The inclination of the anchors should match or exceed the inclination of the adjacent slope. The anchors should have a minimum of 5 feet of vertical soil coverage above the strands throughout the length of the anchor and at least 10 feet of horizontal soil coverage at the tip of the anchor. Additional vertical and horizontal coverage may be required if the tiebacks will be post-grouted. Double corrosion protection is required for the permanent tieback anchors. Corrosion protection is not required for temporary tieback anchors. Centralizers should be used to keep the tieback in the center of the hole during grouting. Structural grout or concrete should be used to fill the bond zone of the tiebacks. A bond breaker, such as plastic sheathing, should be placed around the portion of the tieback located within the no-load zone if the shoring contractor plans to grout both the bond zone and unbonded zone of the tiebacks in a single stage. If the shoring contractor does not plan to use a bond breaker to isolate the no-load zone, GeoEngineers should be contacted to provide recommendations. Loose soil and slough should be removed from the holes drilled for tieback anchors prior to installing the tieback. The contractor should take necessary precautions to minimize loss of ground and prevent disturbance to previously installed anchors and existing improvements in the site vicinity. Holes drilled for tiebacks should be grouted/filled promptly to reduce the potential for loss of ground. Tieback anchors should develop anchorage in the glacially consolidated soils. We recommend that spacing between tiebacks be at least three times the diameter of the anchor hole to minimize group interaction. We recommend a preliminary design load transfer value between the anchor and soil of 4 kips per foot for glacially consolidated soils and 1.5 kips per foot for fill deposits. The tieback anchors should be verification- and proof-tested to confirm that the tiebacks have adequate pullout capacity. The pullout resistance of tiebacks should be designed using a factor of safety of 2. The pullout resistance should be verified by completing at least two successful verification tests in each soil type and a minimum of four total tests for the project. Each tieback should be proof-tested to 133 percent of the design load. Verification and proof tests should be completed as described in Appendix D, Ground Anchor Load Tests and Shoring Monitoring Program. The tieback layout and inclination should be checked to confirm that the tiebacks do not interfere with adjacent buried utilities. Drainage Drainage for soldier pile and lagging walls is achieved through seepage through the timber lagging. Seepage flows at the bottom of the excavation should be contained and controlled in order to prevent loss of soil from behind the lagging. Drainage should be provided for permanent below-grade walls as described below in the “Below-Grade Walls” section of this report. August 2, 2016 | Page 8 File No. 2202-024-00 Construction Considerations Temporary casing or drilling fluid may be required to install the soldier piles and tiebacks where: ■ loose fill is present; and ■ the native soils do not have adequate cementation or cohesion to prevent caving or raveling; and/or perched groundwater is present. GeoEngineers should be allowed to observe and document the installation and testing of the shoring to verify conformance with the design assumptions and recommendations. Shallow Foundations Subgrade soils at foundation elevation level for the project will be dependent on the depth of excavation and the finish floor elevation. The soils at the anticipated foundation elevation vary across the site and may consist of existing fill or glacially consolidated soils and sandstone bedrock, as such, the bearing capacity and subgrade preparation will vary. Where foundations bear on competent glacially consolidated soils or bedrock a high allowable bearing capacity value can be used. Where fill is present at foundation subgrade elevation, a lower allowable bearing capacity should be used. Where the west side of the proposed garage is adjacent to the existing garage, the planned shallow foundations should extend to a depth such that the loads are not transferred to the existing garage foundations. A line of influence extending at a 1H:1V slope from the bottom of the planned garage foundations should not intercept the existing garage foundations or structure. A controlled density-fill (CDF) bearing pad can be used below the planned garage foundations to lower the effective bottom of foundation. The CDF bearing pad shall extend a minimum of 2 feet beyond the edges of the new footing. More detail regarding recommended subgrade preparation and allowable bearing pressures for shallow foundations are presented below. Allowable Bearing Pressure We recommend using an allowable bearing pressure of 10 ksf for mat foundations and isolated spread footing foundations bearing on the dense to very dense glacially consolidated soils or sandstone bedrock. For foundations bearing on properly compacted structural fill extended down to dense to very dense glacially consolidated soils or bedrock, an allowable bearing pressure of 6 ksf may be used. The estimated depth to the dense to very dense glacially consolidated soils are summarized in Table 3. TABLE 3. ESTIMATED DEPTH TO DENSE TO VERY DENSE GLACIALLY CONSOLIDATED SOILS FOR FOUNDATION SUPPORT Exploration Number Approximate Depth to Competent Glacially Consolidated Soils1 (feet) GEI-1 10 GEI-2 14 GEI-3 10 GEI-4 12 GEI-5 11 August 2, 2016 | Page 9 File No. 2202-024-00 Exploration Number Approximate Depth to Competent Glacially Consolidated Soils1 (feet) GEI-6 5 GEI-7 5 Notes: 1Depth below existing ground surface Where foundations are planned to bear on existing fill or highly weathered glacial soils (elevations higher than shown in Table 3), we recommend a minimum of 2 feet be overexcavated below the foundation elevation and replaced with compacted structural fill. Existing fill or highly weathered glacial soils will still remain for this condition; therefore, we recommend an allowable bearing pressure of 3 ksf be used. The zone of structural fill below the foundation should extend beyond the faces of the footing a distance at least equal to the thickness of the structural fill. The zone of structural fill should be compacted to at least 95 percent of the maximum dry density (MDD) in general accordance with ASTM D 1557. If loose existing fill is encountered, further overexcavation may be necessary. The allowable soil bearing pressures provided above apply to the total of dead and long-term live loads and may be increased by up to one-third for wind or seismic loads. The allowable soil bearing pressures are net values. We recommend that conventional shallow foundations be a minimum of 36 inches wide and continuous wall footings be a minimum of 16 inches wide. Exterior footings should be founded a minimum of 18 inches below the lowest adjacent grade. Interior footings should be founded a minimum of 12 inches below top of slab. Settlement Provided that all loose soil is removed and that the subgrade is prepared as recommended under “Construction Considerations” below, we estimate that the total settlement of shallow foundations will be about 1 inch or less. The settlements will occur rapidly, essentially as loads are applied. Differential settlements between footings could be half of the total settlement. Note that smaller settlements will result from lower applied loads. Lateral Resistance Lateral foundation loads may be resisted by passive resistance on the sides of footings and by friction on the base of the shallow foundations. For shallow foundations supported on native soils or structural fill, the allowable frictional resistance may be computed using a coefficient of friction of 0.4 applied to vertical dead-load forces. The allowable passive resistance may be computed using an equivalent fluid density of 390 pounds per cubic foot (pcf) (triangular distribution). This value is appropriate for foundation elements that are poured directly against undisturbed glacial till or surrounded by structural fill. The allowable passive resistance for structural fill assumes that the structural fill extends out from the face of the foundation element for a distance of at least equal to 2½ times the height of the element and is compacted to at least 95 percent of the MDD in accordance with ASTM D-1557. August 2, 2016 | Page 10 File No. 2202-024-00 The above coefficient of friction and passive equivalent fluid density values incorporate a factor of safety of about 1.5. Construction Considerations We recommend that the condition of all subgrade areas be observed by GeoEngineers to evaluate whether the work is completed in accordance with our recommendations and whether the subsurface conditions are as anticipated. If foundation construction is completed during periods of wet weather, foundation subgrades are recommended to be protected with a rat slab consisting of 2 to 4 inches of lean or structural concrete. If soft areas are present at the footing subgrade elevation, the soft areas should be removed and replaced with lean concrete or structural fill at the direction of GeoEngineers. We recommend that the contractor consider leaving the subgrade for the foundations as much as 6 to 12 inches high, depending on soil and weather conditions, until excavation to final subgrade is required for foundation reinforcement. Leaving subgrade high will help reduce damage to the subgrade resulting from construction traffic for other activities. Slab-on-Grade Floors Subgrade Preparation The exposed subgrade should be evaluated after site grading is complete. Proof-rolling with heavy, rubber-tired construction equipment should be used for this purpose during dry weather and if access for this equipment is practical. Probing should be used to evaluate the subgrade during periods of wet weather or if access is not feasible for construction equipment. The exposed soil should be firm and unyielding, and without significant groundwater. Disturbed areas should be recompacted if possible or removed and replaced with compacted structural fill. The site should be rough graded to approximately 1 foot above slab subgrade elevation prior to foundation construction in order to protect the slab subgrade soils from deterioration from wet weather or construction traffic. After the foundations have been constructed, the remaining soils can be removed to final subgrade elevation followed by immediate placement of the capillary break material. In areas were existing fill is present below buildings, the existing soil may be left in place below the slab provided the slab is founded on at least 1 foot of structural fill compacted to 95 percent of the MDD in accordance with ASTM D1557. The upper foot of existing fill should also be recompacted to a firm condition prior to placement of the 1-foot-thick layer of structural fill. Design Parameters Conventional slabs may be supported on-grade, provided the subgrade soils are prepared as recommended in the “Subgrade Preparation” section above. For slabs designed as a beam on an elastic foundation, a modulus of subgrade reaction of 150 pounds per cubic inch (pci) may be used for slabs supported on glacial till. For slabs supported on a 1-foot layer of structural fill overlying existing fill soils, we recommend a modulus of subgrade reaction of 100 pci. August 2, 2016 | Page 11 File No. 2202-024-00 We recommend that the slab-on-grade floors be underlain by a 6-inch-thick capillary break consisting of 1½-inch minus clean crushed gravel with negligible sand or silt meeting the requirements Washington State Department of Transportation (WSDOT) Standard Specification 9-03.1(4)C, grading No. 57 or Mineral Aggregate Type 22 (¾-inch crushed gravel), City of Seattle Standard Specification 9-03.16. Provided that loose soil is removed and the subgrade is prepared as recommended, we estimate that slabs-on-grade will not settle appreciably. Below-Slab Drainage We expect the static groundwater level to be located well below the slab-on-grade level for the proposed building; however perched groundwater may be present above the slab subgrade elevation. We recommend installing an underslab drainage system to remove water from below the slabs-on-grade. The underslab drainage system should include an interior perimeter drain and one or more longitudinal drains with transverse pipes placed at a nominal spacing of 20 feet. The location of the longitudinal drain(s) will depend on the foundation and below-grade structure design and may need to be modified to two or more transverse drains or drains located behind interior cast-in-place walls. The civil engineer should develop a conceptual foundation drainage plan for GeoEngineers to review. The drains should consist of perforated Schedule 40 polyvinyl chloride (PVC) pipes with a minimum diameter of 4 inches placed in a trench at least 12 inches deep. The top of the underslab drainage system trenches should coincide with the base of the capillary break layer. The underslab drainage system pipes should have adequate slope to allow positive drainage to the sump/gravity drain. The drainage pipe should be perforated. Perforated pipe should have two rows of ½-inch holes spaced 120 degrees apart and at 4 inches on center. The underslab drainage system trenches should be backfilled with Mineral Aggregate Type 22 or Type 5 (1-inch washed gravel), City of Seattle Standard Specification 9-03.16, or gravel backfill for drains in conformance with WSDOT Standard Specification 9-03.12(4). The material should be wrapped with a geotextile filter fabric meeting the requirements of construction geotextile for underground drainage, WSDOT Standard Specification 9-33. The underslab drainage system pipes should be connected to a header pipe and routed to a sump or gravity drain. Appropriate cleanouts for drainpipe maintenance should be installed. A larger diameter pipe will allow for easier maintenance of drainage systems. The flow rate for the planned excavation in the below-slab drainage and below-grade wall drainage systems is anticipated to be on the order of 5 to 10 gpm. If no special waterproofing measures are taken, leaks and/or seepage may occur in localized areas of the below-grade portion of the building, even if the recommended wall drainage and below-slab drainage provisions are constructed. If leaks or seepage is undesirable, below-grade waterproofing should be specified. A vapor barrier should be used below slab-on-grade floors located in occupied portions of the building. Specification of the vapor barrier requires consideration of the performance expectations of the occupied space, the type of flooring planned and other factors, and is typically completed by other members of the project team. If partial below-grade waterproofing is specified (for instance, for elevator pits), the waterproofing should extend to at least the elevation of the lowest finished floor so that the waterproofing will be located above the elevation where foundation drainage is provided. August 2, 2016 | Page 12 File No. 2202-024-00 Below-Grade Walls Permanent Below-Grade Walls Permanent below-grade walls constructed in front of temporary shoring walls should be designed using the earth pressures presented in Figure 4. Foundation surcharge loads and traffic surcharge loads should be incorporated into the design of the below-grade walls using the surcharge pressures presented in Figure 5. Other surcharge loads, such as from construction equipment or construction staging areas, should be considered on a case-by-case basis. We can provide the lateral pressures from these surcharge loads as the design progresses. The soil pressures recommended above assume that wall drains will be installed to prevent the buildup of hydrostatic pressure behind the walls, as described above in the “Excavation Support” section of this report, and tied to permanent drains to remove water to suitable discharge points. Other Cast-in-Place Walls Conventional cast-in-place walls may be necessary for small retaining structures located on-site or where temporary open cuts are used for excavation support. The lateral soil pressures acting on conventional cast-in-place subsurface walls will depend on the nature, density and configuration of the soil behind the wall and the amount of lateral wall movement that can occur as backfill is placed. For walls that are free to yield at the top at least 0.1 percent of the height of the wall, soil pressures will be less than if movement is limited by such factors as wall stiffness or bracing. Assuming that the walls are backfilled and drainage is provided as outlined in the following paragraphs, we recommend that yielding walls supporting horizontal backfill be designed using an equivalent fluid density of 35 pcf (triangular distribution), while non-yielding walls supporting horizontal backfill be designed using an equivalent fluid density of 55 pcf (triangular distribution). For seismic loading conditions, a rectangular earth pressure equal to 14H pounds per square foot (psf) (where H is the height of the wall in feet) should be added to the active/at-rest pressures. A traffic surcharge pressure of 70 psf should also be included in the design, as appropriate. Other surcharge loading should be applied as appropriate using the recommendations provided in Figure 5. We recommend that below-grade wall or other retaining wall foundations be designed using the foundation recommendations provided above under “Shallow Foundations.” For retaining walls independent of building structures (grade-transition walls), the retaining wall footings may be supported on 2 feet of structural fill placed over the existing fill soils. The upper foot of existing fill should also be recompacted to a firm condition prior to placement of the 2-foot-thick layer of structural fill. An allowable bearing pressure of 3 ksf may be used for this foundation support condition. Lateral resistance for conventional cast-in-place walls can be provided by frictional resistance along the base of the wall and passive resistance in front of the wall. For walls founded on native soils or structural fill, the allowable frictional resistance may be computed using a coefficient of friction of 0.4 applied to vertical dead-load forces. The allowable passive resistance may be computed using an equivalent fluid densities of 390 pcf (triangular distribution). The allowable passive resistance for structural fill assumes that the structural fill extends out from the face of the foundation element for a distance of at least equal to 2½ times the height of the element and is compacted to at least 95 percent of the MDD in accordance August 2, 2016 | Page 13 File No. 2202-024-00 with ASTM D-1557. The above coefficient of friction and passive equivalent fluid density values incorporate a factor of safety of about 1.5. The above soil pressures assume that wall drains will be installed to prevent the buildup of hydrostatic pressure behind the walls, as discussed below. Drainage Positive drainage should be provided behind cast-in-place retaining walls by placing a minimum 2-foot-wide zone of Mineral Aggregate Type 17 (bank run gravel), City of Seattle Standard Specification 9-03.16, with the exception that the percent passing the U.S. No. 200 sieve is to be less than 3 percent. Alternatively, the 2-foot-wide zone of material may consist of gravel backfill for walls in conformance with WSDOT Standard Specification 9-03.12(2). A perforated drainpipe should be placed near the base of the retaining wall to provide drainage. The drainpipe should be surrounded by a minimum of 6 inches of Mineral Aggregate Type 22 (¾-inch crushed gravel) or Type 5 (1-inch washed gravel), City of Seattle Standard Specification 9-03.16, or gravel backfill for drains in conformance with WSDOT Standard Specification 9-03.12(4). The material should be wrapped with a geotextile filter fabric meeting the requirements of construction geotextile for underground drainage, WSDOT Standard Specification 9-33. The wall drainpipe should be connected to a header pipe and routed to a sump or gravity drain. Appropriate cleanouts for drainpipe maintenance should be installed. A larger-diameter pipe will allow for easier maintenance of drainage systems. Earthwork Stripping, Clearing and Grubbing We recommend that all new pavement and structure areas be stripped of organic-rich soils (sod, grass, topsoil), and vegetation. Based on our observations, we anticipate that stripping depths will generally be about 6 to 12 inches. Stripping depths will be locally greater where large trees are cleared and grubbed. The stripped organic soil may be stockpiled for later use as topsoil for landscaping purposes. Erosion and Sedimentation Control Potential sources or causes of erosion and sedimentation depend upon construction methods, slope length and gradient, amount of soil exposed and/or disturbed, soil type, construction sequencing, and weather. The project’s impact on erosion-prone areas can be reduced by implementing an erosion and sedimentation control plan. The plan should be designed in accordance with applicable City and/or county standards. The plan should incorporate basic planning principles including: ■ scheduling grading and construction to reduce soil exposure; ■ retaining existing vegetation whenever feasible; ■ revegetating or mulching denuded areas; ■ directing runoff away from denuded areas; ■ minimizing the length and steepness of slopes with exposed soils; ■ decreasing runoff velocities; August 2, 2016 | Page 14 File No. 2202-024-00 ■ confining sediment to the project site; ■ inspecting and maintaining control measures frequently; ■ covering soil stockpiles; and ■ implementing proper erosion control best management practices (BMPs). Temporary erosion protection should be used and maintained in areas with exposed or disturbed soils to help reduce the potential for erosion and reduce transport of sediment to adjacent areas. Temporary erosion protection should include the construction of a silt fence around the perimeter of the work area prior to the commencement of grading activities. Permanent erosion protection should be provided by reestablishing vegetation using hydroseeding and/or landscape planting. Until the permanent erosion protection is established and the site is stabilized, site monitoring should be performed by qualified personnel to evaluate the effectiveness of the erosion control measures and repair and/or modify them as appropriate. Provisions for modifications to the erosion control system based on monitoring observations should be included in the erosion and sedimentation control plan. Subgrade Preparation The exposed subgrade in structure and hardscape areas should be evaluated after site excavation is complete. Disturbed areas below slabs and foundations should be recompacted if the subgrade soil consists of granular material. If the subgrade soils consist of disturbed soils, it will likely be necessary to remove and replace the disturbed soil with structural fill unless the soil can be adequately moisture- conditioned and compacted. Structural Fill Fill placed to support structures, placed behind retaining structures, and placed below pavements and sidewalks will need to be specified as structural fill as described below: ■ Structural fill placed within utility trenches and below pavement and sidewalk areas and below foundations should meet the requirements of Mineral Aggregate Type 17 (bank run gravel), City of Seattle Standard Specification 9-03.16, or WSDOT common borrow as described in Section 9-03.14(3). Common borrow is only suitable for use during dry weather. If fill is placed during wet weather, WSDOT gravel borrow should be used, as described in Section 9-03.14(1). ■ Structural fill placed as capillary break material should meet the requirements of Type 22 (¾-inch crushed gravel), City of Seattle Standard Specification 9-03.16, or Section 9-03.1(4)C, grading No. 57 of the WSDOT Standard Specifications (1½-inch minus crushed gravel). ■ Structural fill placed behind retaining walls should meet the requirements of Mineral Aggregate Type 17 (bank run gravel), City of Seattle Standard Specification 9-03.16, or WSDOT gravel backfill for walls Section 9-03.12(2). ■ Structural fill placed around perimeter footing drains, underslab drains and cast-in-place wall drains should meet the requirements of Mineral Aggregate Type 5 (1-inch washed gravel) or Type 22 (¾-inch crushed gravel), City of Seattle Standard Specification 9-03.16, or WSDOT gravel backfill for drains Section 9-03.12(4). August 2, 2016 | Page 15 File No. 2202-024-00 ■ Structural fill placed as crushed surfacing base course below pavements and sidewalks should meet the requirements of Mineral Aggregate Type 2 (1¼-inch minus crushed rock), City of Seattle Standard Specification 9-03.16, or Section 9-03.9(3) of the WSDOT Standard Specifications. On-site Soils The on-site soils are moisture-sensitive and generally have natural moisture contents higher than the anticipated optimum moisture content for compaction. As a result, the on-site soils will likely require moisture conditioning in order to meet the required compaction criteria during dry weather conditions and will not be suitable for reuse during wet weather. Furthermore, most of the fill soils required for the project have specific gradation requirements, and the on-site soils do not meet these gradation requirements. If the contractor wants to use on-site soils for structural fill, GeoEngineers can evaluate the on-site soils for suitability as structural fill, as required. Fill Placement and Compaction Criteria Structural fill should be mechanically compacted to a firm, non-yielding condition. Structural fill should be placed in loose lifts not exceeding 1 foot in thickness. Each lift should be conditioned to the proper moisture content and compacted to the specified density before placing subsequent lifts. Structural fill should be compacted to the following criteria: ■ Structural fill placed in building areas (supporting or adjacent to foundations or slab-on-grade floors) should be compacted to at least 95 percent of the MDD estimated in general accordance with ASTM D 1557. ■ Structural fill placed within 10 feet of the back of subgrade and retaining walls should be compacted to between 90 and 92 percent of the MDD. Care should be taken when compacting fill against subsurface walls to avoid over-compaction and hence overstressing the walls. Structural fill beyond this 10-foot zone should be compacted to at least 95 percent of the MDD. ■ Structural fill in new pavement and roadway areas, including utility trench backfill, should be compacted to 90 percent of the MDD, except that the upper 2 feet of fill below final subgrade should be compacted to 95 percent of the MDD. ■ Structural fill placed as crushed rock base course below pavements should be compacted to 95 percent of the MDD. We recommend that GeoEngineers be present during probing of the exposed subgrade soils in building and pavement areas, and during placement of structural fill. We will evaluate the adequacy of the subgrade soils and identify areas needing further work, perform in-place moisture-density tests in the fill to verify compliance with the compaction specifications, and advise on any modifications to the procedures that may be appropriate for the prevailing conditions. August 2, 2016 | Page 16 File No. 2202-024-00 Weather Considerations The on-site soils contain a sufficient percentage of fines (silt and clay) to be moisture-sensitive. When the moisture content of these soils is more than a few percent above the optimum moisture content, these soils become muddy and unstable, and operation of equipment on these soils is difficult. Additionally, disturbance of near-surface soils should be expected if earthwork is completed during periods of wet weather. During wet weather, we recommend that: ■ The ground surface in and around the work area should be sloped so that surface water is directed away from the work area. The ground surface should be graded such that areas of ponded water do not develop. The contractor should take measures to prevent surface water from collecting in excavations and trenches. Measures should be implemented to remove surface water from the work area. ■ Slopes with exposed soils should be covered with plastic sheeting or similar means. ■ The site soils should not be left uncompacted and exposed to moisture. Sealing the surficial soils by rolling with a smooth-drum roller prior to periods of precipitation will reduce the extent to which these soils become wet or unstable. ■ Construction traffic should be restricted to specific areas of the site, preferably areas that are surfaced with materials not susceptible to wet weather disturbance. ■ Construction activities should be scheduled so that the length of time that soils are left exposed to moisture is reduced to the extent practicable. Permanent Slopes We recommend that permanent cut and fill slopes be constructed no steeper than 2H:1V. To achieve uniform compaction, we recommend that fill slopes be overbuilt slightly (1 to 2 feet) and subsequently cut back to expose properly compacted fill. We recommend that the finished slope faces be compacted by track walking with the equipment running perpendicular to the slope contours so that the track grouser marks help provide an erosion-resistant slope texture. To reduce erosion, newly constructed slopes should be planted or hydroseeded shortly after completion of grading. Until the vegetation is established, some sloughing and raveling of the slopes should be expected. This may require localized repairs and reseeding. Temporary covering, such as clear heavy plastic sheeting, jute fabric, loose straw, or excelsior or straw/coconut matting, should be used to protect the slopes during periods of rainfall. Pavement Recommendations Subgrade Preparation We recommend that the subgrade soils in new pavement areas be prepared and evaluated as described in the “Earthwork” section of this report. We recommend that the subgrade be compacted to at least 95 percent of the MDD per ASTM D 1557 prior to placing pavement section materials. If the subgrade soils are loose or soft, it may be necessary to excavate the soils and replace them with structural fill. A layer of suitable woven geotextile fabric may be placed over soft subgrade areas to limit the thickness of structural fill required to bridge soft, yielding areas. The depth of overexcavation or fabric placement should be evaluated by GeoEngineers during construction. August 2, 2016 | Page 17 File No. 2202-024-00 New Hot-Mix Asphalt Pavement At a minimum, paved areas exposed to automobile traffic only should consist of 2 inches of hot-mix asphalt (HMA) (Class ½ inch, PG-58) over 4 inches of crushed surfacing base course. In areas of truck traffic, new pavement sections should consist of at least 3 inches of HMA over 6 inches of crushed surfacing base course. The crushed surfacing base course should meet the requirements of Mineral Aggregate Type 2 (1¼-inch minus crushed rock), City of Seattle Standard Specification 9-03.16, or Section 9-03.9(3) of the WSDOT Standard Specifications. Recommended Additional Geotechnical Services GeoEngineers should be retained to review the project plans and specifications when complete to confirm that our design recommendations have been implemented as intended. Any changes in design, especially the incorporation of elements that deepen the required depth of excavation, will likely go below the water table and could require additional temporary construction dewatering measures. During construction, GeoEngineers should observe the installation of the shoring system, review/collect shoring and groundwater monitoring data, evaluate the suitability of the foundation subgrades, observe installation of subsurface drainage measures, evaluate structural backfill, observe the condition of temporary cut slopes, and provide a summary letter of our construction observation services. The purposes of GeoEngineers construction phase services are to confirm that the subsurface conditions are consistent with those observed in the explorations and other reasons described in Appendix E, Report Limitations and Guidelines for Use. LIMITATIONS We have prepared this report for the exclusive use of Valley Medical Center and their authorized agents for the VMC FY 2017 Parking Garage Project in Renton, Washington. Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in the field of geotechnical engineering in this area at the time this report was prepared. No warranty or other conditions, express or implied, should be understood. Any electronic form, facsimile or hard copy of the original document (email, text, table and/or figure), if provided, and any attachments are only a copy of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record. Please refer to Appendix E titled “Report Limitations and Guidelines for Use” for additional information pertaining to use of this report. REFERENCES City of Seattle, 2014, “Standard Specifications for Road, Bridge and Municipal Construction.” International Code Council, 2012, “International Building Code.” Mullineaux D.R., 1965 “Geologic Map of the Renton Quadrangle, King County, Washington.” USGS August 2, 2016 | Page 18 File No. 2202-024-00 U.S. Department of Transportation, Federal Highways Administration, 1999, “Geotechnical Engineering Circular No. 4, Ground Anchors and Anchored Systems,” FHWA Report No. FHWA-IF-99-015. U.S. Geological Survey – National Seismic hazard Mapping project Software, “Earthquake Ground Motion Parameters, Version 5.0.9a,” 2002 data, 2009. Washington State Department of Transportation, 2014, “Standard Specifications for Road, Bridge and Municipal Construction.” August 2, 2016 | Page 19 File No. 2202-024-00 FIGURES ! µ Vicinity Map Figure 1 Valley Medical CenterRenton, Washington 2,000 2,0000 Feet Data Sources: Open Street Map, 2016. Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication.3. It is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without permission. Transverse Mercator, Zone 10 N North, North American Datum 1983North arrow oriented to grid northPath: P:\2\2202024\GIS\220202400_F1_VicinityMap.mxdMap Revised: 4/19/2016 glohrmeyerSite Talbot Road SouthProposed Parking Garage Proposed MOB 23 22 21 25 24 28 27 26 B-2 B-1 B-2 B-4 B-6 B-7 B-5 B-3 GEI-3 GEI-4 GEI-2 GEI-6 GEI-7 GEI-8 GEI-9 GEI-10 GEI-11 GEI-5 HA-2 HA-1 B-2 B-3 B-4 B-1 1 GEI-1 Main Hospital Building Talbot Professional Building Psychiatry Wing Northwest Pavilion Building Parking Garage Medical Arts Center Olympic Building Valley Professional Center North Building 60 65 70 75 80 85 9090 85807550407555100 95W E N S Feet 0100 100 P:\2\2202024\CAD\00\Geotech\2202024-00_F02_Site Plan.dwg TAB:F2 Date Exported: 05/06/16 - 12:39 by cstickelValley Medical Center Renton, Washington Site Plan Figure 2 Projection: NAD83 Washington State Planes, North Zone, US Foot. Notes: 1.The locations of all features shown are approximate. 2.This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication. Data Source: Base aerial photo for Microsoft bing map server. Legend Boring by GeoEngineers, 2016 Boring by Terra Associates, 1989 Boring by Converse Consultants NW, 1987 Boring by Converse Consultants NW, 1989 Test Pit by Converse Consultants NW, 1987 B-1 1 B-2 GEI-1 21 Proposed Building HA-1 B-1 Boring by GeoEngineers, 2001 Hand Auger by GeoEngineers, 2001 . . ... No Load Zone to Uppermost Tieback, Feet Height of Excavation, Feet Distance From Ground Surface Horizontal Load in Uppermost Ground Anchor Maximum Apparent Earth Pressure Pounds per Square Foot Legend Soldier Pile Embedment Depth, feet Figure 3 Valley Medical Center Renton, Washington Earth Pressure Diagram Soldier Pile & Tieback Wall P:\2\2202024\CAD\00\Geotech\2202024-00_F03-F05_EPDs.dwg TAB:F3 Date Exported: 08/02/16 - 12:32 by cstickel.. Load Case Static Seismic Passive Pressure Coefficient (X)390 520 Passive Earth Pressure Coefficient (See Table) .. 1. Active, apparent earth pressure and surcharge act over the pile spacing above the base of the excavation. 2. Passive earth pressure acts over 2.5 times the concreted diameter of the soldier pile, or the pile spacing, whichever is less. 3. Passive pressure includes a factor of safety of 1.5 5.This pressure diagram is appropriate for temporary soldier pile and tieback walls. If additional surcharge loading (such as from soil stockpiles, excavators, dumptrucks, cranes, or concrete trucks) is anticipated, GeoEngineers should be consulted to provide revised surcharge pressures. Notes: 4. Additional surcharge from footings of adjacent buildings should be included in accordance with recommendations provided on Figure 5. Not to Scale 6. Seismic earth pressure to be included for design of permanent walls. . NOT TO SCALE Legend Notes . 1.This pressure diagram is appropriate for permanent basement walls. If additional surcharge loading (such as from soil stockpiles, excavators, dumptrucks, cranes, or concrete trucks) is anticipated, GeoEngineers should be consulted to provide revised surcharge pressures. 2.The static earth pressure does not include a factor of safety and represents the actual anticipated static earth pressure. Maximum Static Earth Pressure Pounds per Square Foot Height of Basement Wall, Feet Foundation Embedment Depth, Feet Figure 4 Valley Medical Center Renton, Washington Earth Pressure Diagram Permanent Below Grade Walls P:\2\2202024\CAD\00\Geotech\2202024-00_F03-F05_EPDs.dwg TAB:F4 Date Exported: 05/06/16 - 12:19 by cstickel 1. Procedures for estimating surcharge pressures shown above are based on Manual 7.02 Naval Facilities Engineering Command, September 1986 (NAVFAC DM 7.02). 2. Lateral earth pressures from surcharge should be added to earth pressures presented on Figures 3 and 4. 3. See report text for where surcharge pressures are appropriate. Definitions: . Point load in pounds Line load in pounds/foot Excavation height below footing, feet Lateral earth pressure from surcharge, psf Surcharge pressure in psf Radians Distribution of in plan view Resultant lateral force acting on wall, pounds Distance from base of excavation to resultant lateral force, feet Notes: Figure 5 Valley Medical Center Renton, Washington Recommended Surcharge Pressure P:\2\2202024\CAD\00\Geotech\2202024-00_F03-F05_EPDs.dwg TAB:F5 Date Exported: 05/06/16 - 12:19 by cstickel APPENDICES APPENDIX A Field Explorations APPENDIX A FIELD EXPLORATIONS Subsurface conditions were explored at the site by drilling seven borings (GEI-1 through GEI-7). The borings were completed to depths of approximately 15½ to 35¾ feet below existing site grades. The borings were completed by Geologic Drill, Inc. on April 4, 2016. The locations of the explorations were surveyed by Bush Roed & Hitchings, Inc. as part of the general project survey. The exploration locations are shown on the Site Plan, Figure 2. Borings The borings were completed using track-mounted, continuous-flight, hollow-stem auger drilling equipment, owned and operated by Geologic Drill, Inc. of Spokane, Washington. The borings were continuously monitored by a geotechnical engineer or geologist from our firm who examined and classified the soils encountered, obtained representative soil samples, observed groundwater conditions and prepared a detailed log of each exploration. The soils encountered in the borings were generally sampled at 2½- and 5-foot vertical intervals with a 2-inch outside diameter split-barrel standard penetration test (SPT) sampler. The disturbed samples were obtained by driving the sampler 18 inches into the soil with a 140-pound automatic hammer free-falling 30 inches. The number of blows required for each 6 inches of penetration was recorded. The blow count ("N-value") of the soil was calculated as the number of blows required for the final 12 inches of penetration. This resistance, or N-value, provides a measure of the relative density of granular soils and the relative consistency of cohesive soils. Where very dense soil conditions precluded driving the full 18 inches, the penetration resistance for the partial penetration was entered on the logs. The blow counts are shown on the boring logs at the respective sample depths. Soils encountered in the borings were visually classified in general accordance with the classification system described in Figure A-1. A key to the boring log symbols is also presented in Figure A-1. The logs of the borings are presented in Figures A-2 through A-8. The boring logs are based on our interpretation of the field and laboratory data and indicate the various types of soils and groundwater conditions encountered. The logs also indicate the depths at which these soils or their characteristics change, although the change may actually be gradual. If the change occurred between samples, it was interpreted. The densities noted on the boring logs are based on the blow count data obtained in the borings and judgment based on the conditions encountered. Observations of groundwater conditions were made during drilling. The groundwater conditions encountered during drilling are presented on the boring logs. Groundwater conditions observed during drilling represent a short-term condition and may or may not be representative of the long-term groundwater conditions at the site. Groundwater conditions observed during drilling should be considered approximate. August 2, 2016 | Page A-1 File No. 2202-024-00 AC Cement ConcreteCC Asphalt Concrete No Visible SheenSlight Sheen Moderate SheenHeavy SheenNot Tested NSSS MSHSNT ADDITIONAL MATERIAL SYMBOLS Measured groundwater level in exploration, well, or piezometer Measured free product in well or piezometer Graphic Log Contact Groundwater Contact Material Description Contact Laboratory / Field Tests Sheen Classification Sampler Symbol Descriptions NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurfaceconditions. Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made; they are not warranted to be representative of subsurface conditions at other locations or times. GRAPH Topsoil/ Forest Duff/Sod Crushed Rock/Quarry Spalls FIGURE A-1 2.4-inch I.D. split barrel SYMBOLS TYPICAL KEY TO EXPLORATION LOGS CR DESCRIPTIONSLETTER TS GC PT OH CH MH OL GM GP GW DESCRIPTIONS TYPICAL LETTER (APPRECIABLE AMOUNT OF FINES) MAJOR DIVISIONS POORLY-GRADED SANDS,GRAVELLY SAND PEAT, HUMUS, SWAMP SOILSWITH HIGH ORGANICCONTENTS CLEAN SANDS GRAVELS WITH FINES CLEAN GRAVELS HIGHLY ORGANIC SOILS SILTS AND CLAYS SILTS AND CLAYS SANDANDSANDY SOILS GRAVEL AND GRAVELLY SOILS (LITTLE OR NO FINES) FINEGRAINED SOILS COARSE GRAINED SOILS SW MORE THAN 50%OF COARSEFRACTIONRETAINED ON NO.4 SIEVE CL WELL-GRADED SANDS,GRAVELLY SANDS SILTY GRAVELS, GRAVEL - SAND- SILT MIXTURES LIQUID LIMITGREATER THAN 50 SILTY SANDS, SAND - SILTMIXTURES (APPRECIABLE AMOUNTOF FINES) SOIL CLASSIFICATION CHART LIQUID LIMITLESS THAN 50 SANDS WITHFINES SP(LITTLE OR NO FINES) ML SC SM NOTE: Multiple symbols are used to indicate borderline or dual soil classifications MORE THAN 50%OF COARSEFRACTIONPASSING NO. 4SIEVE CLAYEY GRAVELS, GRAVEL -SAND - CLAY MIXTURES CLAYEY SANDS, SAND - CLAYMIXTURES INORGANIC SILTS, ROCKFLOUR, CLAYEY SILTS WITHSLIGHT PLASTICITY ORGANIC SILTS AND ORGANICSILTY CLAYS OF LOWPLASTICITY INORGANIC SILTS, MICACEOUSOR DIATOMACEOUS SILTYSOILS ORGANIC CLAYS AND SILTS OFMEDIUM TO HIGH PLASTICITY INORGANIC CLAYS OF HIGHPLASTICITY MORE THAN 50%PASSING NO. 200SIEVE MORE THAN 50%RETAINED ON NO.200 SIEVE WELL-GRADED GRAVELS,GRAVEL - SAND MIXTURES POORLY-GRADED GRAVELS,GRAVEL - SAND MIXTURES INORGANIC CLAYS OF LOW TOMEDIUM PLASTICITY, GRAVELLYCLAYS, SANDY CLAYS, SILTYCLAYS, LEAN CLAYS GRAPH SYMBOLS Standard Penetration Test (SPT) Shelby tube Piston Direct-Push Bulk or grab Continuous Coring Distinct contact between soil strata Approximate contact between soil strata Contact between geologic units Contact between soil of the samegeologic unit %F%G ALCA CPCSDS HAMCMD OCPMPI PPPPM SATXUC VS Percent fines Percent gravelAtterberg limitsChemical analysis Laboratory compaction testConsolidation testDirect shear Hydrometer analysisMoisture content Moisture content and dry densityOrganic contentPermeability or hydraulic conductivity Plasticity indexPocket penetrometerParts per million Sieve analysisTriaxial compressionUnconfined compression Vane shear Blowcount is recorded for driven samplers as the numberof blows required to advance sampler 12 inches (or distance noted). See exploration log for hammer weightand drop. A "P" indicates sampler pushed using the weight of thedrill rig. A "WOH" indicates sampler pushed using the weight ofthe hammer. Rev. 02/16 1A%F 1B 2 3%F 4 5 6 18 18 18 18 17 18 14 13 22 66 85/11" 71 3 inches asphalt concrete pavement 3 inches base course Brown silty fine to medium sand with gravel(medium dense, moist) (fill) Brown to gray sandy silt (stiff, moist) Brown silty fine to medium sand (mediumdense, moist) With occasional gravel Gray silty fine to medium sand with gravel(medium dense, moist) (weathered glacialtill) Gray silty fine to medium sand with gravel (very dense, moist) (glacial till) AC GP SM ML SM SM SM Oxidation staining, till-fill 53 46 35 13 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger26.5 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/4/20164/4/2016 Not encountered 76.39 NAVD88 1298928.83 165386.17 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)7570656055Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-1 Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-2 Sheet 1 of 2Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 71783/11" White to light gray fine to medium sand (verydense, moist) (Renton FormationSandstone) SM Smoother drilling at 22 feet Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 IntervalElevation (feet)50Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-1 (continued) Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-2 Sheet 2 of 2Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 1 2 3 4%F 5 6 7 8 10 3 14 18 18 18 19 27 50/3"* 12 14 75 54 1 inch crushed gravel surfacing (parking lot surface) Brown silty fine to medium sand with gravel andorganics (medium dense, moist) (fill) Brown silty fine to medium sand with gravel(medium dense, moist) Becomes gray Gray silty fine to medium sand with occasionalgravel (very dense, wet) (glacial till) Becomes moist GP SM SM ML Oxidation staining/orange mottling, till-fill Oxidation staining *Blowcount overstated, sampler bouncing on rock during sampling Water in sampler 3414 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger31 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/4/20164/4/2016 See remarks 90.28 NAVD88 1299094.03 165403.44 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)9085807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-2 Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-3 Sheet 1 of 2Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 8 9 18 11.5 61 50/5.5" White to light gray silty fine to medium sandwith interbedded black coal (very dense,moist) (Renton Formation Sandstone) Gray to brown silt with trace interbeds of blackcoal (hard, dry) SM ML Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 30 IntervalElevation (feet)6560Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-2 (continued) Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-3 Sheet 2 of 2Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 1MC 2 3 4 5 6 7 10 18 12 9 18 10 14 3 25 12 50/3" 48 84 78 1.5 inches crushed gravel surfacing (parking lot surface) Brown silty fine to medium sand with gravel(very loose to medium dense, moist) (fill) With occsaional gravel and occasional coalfragments Grades to gray Gray silty fine to medium sand with occasional gravel (dense to very dense, moist) (glacialtill) GP SM SM Orange mottling Wet sampler 20 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger31.5 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/4/20164/4/2016 See remarks 87.92 NAVD88 1299048.22 165275.15 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)85807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-3 Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-4 Sheet 1 of 2Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 8 9 8 13 41 76 Transitioned to sandier layer Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 30 IntervalElevation (feet)6560Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-3 (continued) Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-4 Sheet 2 of 2Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 1%F 2 3A 3B 4A4B 5 6 18 18 18 11 8 3 6 9 6 20 38 50/3" 1 inch crushed gravel surfacing (parking lot surface) Brown silty fine to medium sand with gravel(loose, moist) (fill) Gray to brown silt with sand (medium stiff,moist to wet) Gray silty fine to medium sand with gravel(medium dense, moist) (weathered glacialtill) Gray silty fine to medium sand with gravel(dense to very dense, moist) (glacial till) Obstruction encountered GP SM ML SM SM Perched water Oxidation staining Perched water Boring could not be advanced further; practicalrefusal met 4920 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger15.5 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/4/20164/4/2016 Not encountered 96.7 NAVD88 1299202 165242.05 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 IntervalElevation (feet)959085Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-4 Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-5 Sheet 1 of 1Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 1 2 3%F 4A 4B 5%F 6 8 10 12 13 10 10 10 6 19 28 92/11.5" 56 1 inch crushed gravel surfacing (parking lot surface) Brown silty fine to medium sand with gravel andtrace organic debris (roots/wood) (loose to medium dense, moist) (fill) Brown silty fine to medium sand withoccasional gravel (medium dense, moist)(weathered glacial till) Becomes brownish orange Gray silty fine to medium sand with occasionalgravel (medium dense, moist) (glacial till) Becomes very dense GP SM SM SM Oxidation staining Silt lenses 35 24 14 7 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger35.8 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/4/20164/4/2016 Not encountered 98.02 NAVD88 1299210.26 165309.34 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)95908580Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-5 Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-6 Sheet 1 of 2Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 7 8 9 11.5 10 10 50/5.5" 50/4" 50/4" White to light gray silty fine to medium sand(very dense, moist) (Renton FormationSandstone) SM Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 30 35 IntervalElevation (feet)757065Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-5 (continued) Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-6 Sheet 2 of 2Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 1 2%F 3 4 5 6 12 12 5 18 18 18 29 36 37 52 75 65 3 inches asphalt concrete pavement 2 inches base course Brown silty fine to medium sand with gravel(medium dense, moist) (fill) Brown silty fine to medium sand withoccasional gravel (medium dense, moist)(weathered glacial till) Gray silty fine to medium sand with occasionalgravel (dense, moist) (glacial till) Becomes very dense Increasing gravel content AC GP SM SM SM Oxidation staining 3910 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger21.5 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/4/20164/4/2016 Not encountered 75.8 NAVD88 1298925.69 165180.99 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)7570656055Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-6 Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-7 Sheet 1 of 1Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 1 2%F 3 4 5 6 5 18 0 6 12 14 50/6"* 60 50/3" 50/5" 50/6" 56 2 inches asphalt concrete pavement 1.5 inch base course Brown silty fine to coarse sand and gravel (verydense, moist) (fill) Brown silty fine to medium sand with gravel(very dense, moist) (weathered glacial till) Gray silty fine to medium sand with gravel (verydense, moist) (glacial till) Becomes with occasional gravel AC GP SM SM SM *Sampler bouncing on rock, blowcountoverstated Oxidation staining No recovery Slow drilling Rougher drilling 2810 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger30.8 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/4/20164/4/2016 Not encountered 87.53NAVD88 1299051.08 165090.91 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)85807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-7 Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-8 Sheet 1 of 2Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 7 8 6 10 50/5" 50/4" Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 30 IntervalElevation (feet)6560Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-7 (continued) Valley Medical Center - Parking Garage Project Renton, Washington 2202-024-00 Task 100 Project: Project Location: Project Number:Figure A-8 Sheet 2 of 2Redmond: Date:5/6/16 Path:\\GEOENGINEERS.COM\WAN\PROJECTS\2\2202024\GINT\02202024.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) APPENDIX B Laboratory Testing APPENDIX B LABORATORY TESTING Soil samples obtained from the explorations were transported to GeoEngineers’ laboratory and evaluated to confirm or modify field classifications, as well as to evaluate engineering properties of the soil samples. Representative samples were selected for laboratory testing to determine the moisture content, percent fines (material passing the U.S. No. 200 sieve) and sieve analyses. The tests were performed in general accordance with test methods of ASTM International (ASTM) or other applicable procedures. Moisture Content Moisture content tests were completed in general accordance with ASTM D 2216 for representative samples obtained from the explorations. The results of these tests are presented on the exploration logs in Appendix A at the depths at which the samples were obtained. Percent Passing U.S. No. 200 Sieve (%F) Selected samples were “washed” through the U.S. No. 200 mesh sieve to estimate the relative percentages of coarse- and fine-grained particles in the soil. The percent passing value represents the percentage by weight of the sample finer than the U.S. No. 200 sieve. These tests were conducted to verify field descriptions and to estimate the fines content for analysis purposes. The tests were conducted in accordance with ASTM D 1140, and the results are shown on the exploration logs in Appendix A at the respective sample depths. August 2, 2016 | Page B-1 File No. 2202-024-00 APPENDIX C Boring Logs from Previous Studies APPENDIX C BORING LOGS FROM PREVIOUS STUDIES Included in this section are logs from previous studies completed in the immediate vicinity of the project site: ■ The logs of four borings (GEI-8 through GEI-11) completed by GeoEngineers and presented in the Valley Medical Center FY 2017 Medical Office Building Geotechnical Report dated May 6, 2016 as task two of this study. ■ The log of one boring (B-1) and eight test pits (21 through 28) completed by Converse Consultants NW in 1987 for the Valley Medical Center Garage project; ■ The log of one boring (B-2) completed by Converse Consultants NW in 1989 for the Valley Medical Center Garage Phase II project; ■ The logs of seven borings (B-1 through B-7) completed by Terra Associates in 1987 for the Valley Medical Center Office Building project; and ■ The logs of four borings (B-1 through B-4) and two hand augers (HA-1 and HA-2) completed by GeoEngineers in 2001 for the Warehouse Office Building project. August 2, 2016 | Page C-1 File No. 2202-024-00 1SA 2%F 3 4 5 16 12 15 6 18 56 50/6" 73 50/5" 65 3 inches asphalt concrete pavement 3 inches base course Gray silty fine to medium sand with gravel (verydense, moist) (glacial till) Becomes with occasional gravel AC GP SM Light oxidation staining31 21 8 5 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger21.5 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/5/20164/5/2016 Not encountered 82.72 NAVD88 1298995.48 165009.65 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)80757065Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-8 Valley Medical Center - Medical Office Building Project Renton, Washington 2202-024-00 Task 200 Project: Project Location: Project Number:Figure A-2 Sheet 1 of 1Redmond: Date:5/6/16 Path:W:\PROJECTS\2\2202024\GINT\0220202400.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 1 2%F 3 4 5MC 12 11.5 15 10 18 35 50/5.5" 90/11" 65 65 1.5 inches asphalt concrete pavement 5.5 inches base course Brown to gray silty fine to coarse sand withgravel and occasional coal fragments(dense, moist) (weathered glacial till) Gray sandy silt with occasional gravel (hard,moist) (glacial till) Gray silty fine to medium sand with gravel (verydense, moist) Large boulder obstruction Becomes wet AC GP SM ML SM Light oxidation staining Drilling on rock at 12 feet bgs Moved over 5 feet to complete boring Perched water 569 12 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger25.8 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/5/20164/5/2016 See remarks 91.83 NAVD88 1299121.94 165017.35 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)9085807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-9 Valley Medical Center - Medical Office Building Project Renton, Washington 2202-024-00 Task 200 Project: Project Location: Project Number:Figure A-3 Sheet 1 of 2Redmond: Date:5/6/16 Path:W:\PROJECTS\2\2202024\GINT\0220202400.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 6950/3" Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 IntervalElevation (feet)Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-9 (continued) Valley Medical Center - Medical Office Building Project Renton, Washington 2202-024-00 Task 200 Project: Project Location: Project Number:Figure A-3 Sheet 2 of 2Redmond: Date:5/6/16 Path:W:\PROJECTS\2\2202024\GINT\0220202400.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 1 2SA 3 4 5 6 18 18 18 18 18 11 10 11 29 48 82 50/5" 1.5 inches asphalt concrete pavement 4 inches base course Brown/orange silty fine to coarse sand withgravel (loose to medium dense, moist) (fill) Gray silty fine sand with occasional gravel(medium dense, moist) Becomes wet Gray silty fine to medium sand with occasional gravel (dense, moist) (glacial till) Becomes very dense Gray silty fine to medium sand (very dense,moist) (Renton Formation Sandstone) AC GP SM SM SM SM Oxidation staining Perched water 4117 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger20.9 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/5/20164/5/2016 See remarks 86.23 NAVD88 1298928.15 164820.19 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)85807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-10 Valley Medical Center - Medical Office Building Project Renton, Washington 2202-024-00 Task 200 Project: Project Location: Project Number:Figure A-4 Sheet 1 of 1Redmond: Date:5/6/16 Path:W:\PROJECTS\2\2202024\GINT\0220202400.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 1 2%F 3 4 5 18 15 7 10 8 52 50 50/1"* 50/4" 50/6" 1.5 inches asphalt concrete pavement Brown silty fine to medium sand with gravel(medium dense, moist) (fill) Brown to gray silty fine to medium sand withoccasional gravel and coal fragments (verydense, moist) (weathered glacial till) Gray silty fine to medium sand with gravel (verydense, moist) (glacial till) Increasing gravel AC SM SM SM No base course Oxidation staining *Sampler bouncing on rock, blowcountoverstated 3812 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By DTMDrilled Notes: SJB Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Diedrich D50 Track Rig Geologic Drill, Inc.DrillingMethod Hollow-Stem Auger26.5 Autohammer140 (lbs) / 30 (in) Drop DrillingEquipment 4/5/20164/5/2016 Not encountered 91.62 NAVD88 1299044.81 164830.36 WA State Plane,North NAD83 (feet) Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)9085807570Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-11 Valley Medical Center - Medical Office Building Project Renton, Washington 2202-024-00 Task 200 Project: Project Location: Project Number:Figure A-5 Sheet 1 of 2Redmond: Date:5/6/16 Path:W:\PROJECTS\2\2202024\GINT\0220202400.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) 61041 With interbeds of coarse sand and trace gravel Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 IntervalElevation (feet)Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-11 (continued) Valley Medical Center - Medical Office Building Project Renton, Washington 2202-024-00 Task 200 Project: Project Location: Project Number:Figure A-5 Sheet 2 of 2Redmond: Date:5/6/16 Path:W:\PROJECTS\2\2202024\GINT\0220202400.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD_%FREMARKS FinesContent (%)MoistureContent (%) APPENDIX D Ground Anchor Load Tests and Shoring Monitoring Program APPENDIX D GROUND ANCHOR LOAD TESTS AND SHORING MONITORING PROGRAM Ground Anchor Load Testing The locations of the load tests shall be approved by the Engineer and shall be representative of the field conditions. Load tests shall not be performed until the tieback grout has attained at least 50 percent of the specified 28-day compressive strengths. Where temporary casing of the unbonded length of test tiebacks is provided, the casing shall be installed to prevent interaction between the bonded length of the tieback and the casing/testing apparatus. The testing equipment shall include two dial gauges accurate to 0.001 inch, a dial gauge support, a calibrated jack and pressure gauge, a pump and the load test reaction frame. The dial gauge should be aligned within 5 degrees of the longitudinal nail/tieback axis and shall be supported independently from the load frame/jack and the shoring wall. The hydraulic jack, pressure gauge and pump shall be used to apply and measure the test loads. The jack and pressure gauge shall be calibrated by an independent testing laboratory as a unit. The pressure gauge shall be graduated in 100 pounds per square inch (psi) increments or less and shall have a range not exceeding twice the anticipated maximum pressure during testing unless approved by the Engineer. The ram travel of the jack shall be sufficient to enable the test to be performed without repositioning the jack. The jack shall be supported independently and centered over the tieback so that the tieback does not carry the weight of the jack. The jack, bearing plates and stressing anchorage shall be aligned with the tieback. The initial position of the jack shall be such that repositioning of the jack is not necessary during the load test. The reaction frame should be designed/sized such that excessive deflection of the test apparatus does not occur and that the testing apparatus does not need to be repositioned during the load test. If the reaction frame bears directly on the shoring wall facing, the reaction frame should be designed so as not to damage the facing. Verification Tests Prior to production tieback installation, at least two tiebacks for each soil type shall be tested to validate the design pullout value. All test tiebacks shall be installed by the same methods, personnel, material and equipment as the production anchors. Changes in methods, personnel, material or equipment may require additional verification testing as determined by the Engineer. At least two successful verification tests shall be performed for each installation method and each soil type. The tiebacks used for the verification tests may be used as production tiebacks if approved by the Engineer. August 2, 2016 | Page D-1 File No. 2202-024-00 The allowable tieback load should not exceed 80 percent of the steel ultimate strength. Tieback design test loads should be the design load specified on the shoring drawings. Verification test tiebacks shall be incrementally loaded and unloaded in accordance with the following schedule: Load Hold Time Alignment Load 1 minute 0.25 Design Load (DL) 1 minute 0.5DL 1 minute 0.75DL 1 minute 1.0DL 1 minute 1.25DL 1 minute 1.5DL 60 minutes 1.75DL 1 minute 2.0DL 10 minutes The alignment load shall be the minimum load required to align the testing apparatus and should not exceed 5 percent of the design load. The dial gauge should be zeroed after the alignment load is applied. Nail/tieback deflections during the 1.5 Design Load (DL) test load shall be recorded at 1, 2, 3, 5, 6, 10, 20, 30, 50 and 60 minutes. Proof Tests Proof tests shall be completed on each production tieback. The allowable tieback load should not exceed 80 percent of the steel ultimate strength. Tieback design test loads should be the design load specified on the shoring drawings. Proof tiebacks shall be incrementally loaded and unloaded in accordance with the following schedule: Load Hold Time Alignment Load 1 minute 0.25 Design Load (DL) 1 minute 0.5DL 1 minute 0.75DL 1 minute 1.0DL 1 minute 1.33DL 10 minutes The alignment load shall be the minimum load required to align the testing apparatus and should not exceed 5 percent of the design load. The dial gauge should be zeroed after the alignment load is applied. Nail/tieback deflections during the 1.33DL and 1.5DL test loads shall be recorded at 1, 2, 3, 5, 6 and 10 minutes. Depending upon the tieback deflection performance, the load hold period at 1.33DL (tiebacks) may be increased to 60 minutes. Tieback movement shall be recorded at 1, 2, 3, 5, 6 and 10 minutes. If the tieback deflection between 1 and 10 minutes is greater than 0.04 inches, the 1.33DL load shall be continued to be held for a total of 60 minutes and deflections recorded at 20, 30, 50 and 60 minutes. August 2, 2016 | Page D-2 File No. 2202-024-00 Test Nail/Tieback Acceptance A test tieback shall be considered acceptable when: 1. For verification tests, a tieback is considered acceptable if the creep rate is less than 0.08 inches per log cycle of time between 6 and 60 minutes and the creep rate is linear or decreasing throughout the creep test load hold period. 2. For proof tests, a tieback is considered acceptable if the creep rate is less than 0.04 inches per log cycle of time between 1 and 10 minutes or the creep rate is less than 0.08 inches per log cycle of time between 6 and 60 minutes, and the creep rate is linear or decreasing throughout the creep test load hold period. 3. The total movement at the maximum test load exceeds 80 percent of the theoretical elastic elongation of the unbonded length. 4. Pullout failure does not occur. Pullout failure is defined as the load at which continued attempts to increase the test load result in continued pullout of the test nail/tieback. Acceptable proof-test tiebacks may be incorporated as production tiebacks provided that the unbonded test length of the tieback hole has not collapsed and the test tieback length and number of strands are equal to or greater than the scheduled production tieback at the test location. Test tiebacks meeting these criteria shall be completed by grouting the unbonded length. Maintenance of the temporary unbonded length for subsequent grouting is the contractor’s responsibility. The Engineer shall evaluate the verification test results. Tieback installation techniques that do not satisfy the tieback testing requirements shall be considered inadequate. In this case, the contractor shall propose alternative methods and install replacement verification tiebacks. Shoring Monitoring Preconstruction Survey A shoring monitoring program should be established to monitor the performance of the temporary and/or permanent shoring walls and to provide early detection of deflections that could potentially damage nearby improvements. We recommend that a preconstruction survey of adjacent improvements, such as streets, retaining walls, utilities and buildings, be performed prior to commencing construction. The preconstruction survey should include a video or photographic survey of the condition of existing improvements to establish the preconstruction condition, with special attention to existing cracks in streets, retaining walls or buildings. Optical Survey The shoring monitoring program should include an optical survey monitoring program. The recommended frequency of monitoring should vary as a function of the stage of construction as presented in the following table. August 2, 2016 | Page D-3 File No. 2202-024-00 Construction Stage Monitoring Frequency During excavation and until wall movements have stabilized Twice weekly During excavation if lateral wall movements exceed 1 inch and until wall movements have stabilized Three times per week After excavation is complete and wall movements have stabilized, and before the floors of the building reach the top of the excavation Twice monthly Monitoring should include vertical and horizontal survey measurements accurate to at least 0.01 feet. A baseline reading of the monitoring points should be completed prior to beginning excavation. The survey data should be provided to GeoEngineers for review within 24 hours. For shoring walls, we recommend that optical survey points be established: (1) along the top of the shoring walls and (2) on existing buildings located within a horizontal distance of the shoring walls equal to the height of the wall. The survey points should be located on every other soldier pile along the wall face for soldier pile and tieback shoring and the points along the existing buildings should be located at an approximate spacing of 20 feet. If lateral wall movements are observed to be in excess of ½ inch between successive readings or if total wall movements exceed 1 inch, construction of the shoring walls should be stopped to determine the cause of the movement and to establish the type and extent of remedial measures required. August 2, 2016 | Page D-4 File No. 2202-024-00 APPENDIX E Report Limitations and Guidelines for Use APPENDIX E REPORT LIMITATIONS AND GUIDELINES FOR USE1 This appendix provides information to help you manage your risks with respect to the use of this report. Geotechnical Services Are Performed for Specific Purposes, Persons and Projects This report has been prepared for the exclusive use of Valley Medical Center (VMC) and other project team members for the VMC FY 2017 Parking Garage Project. This report is not intended for use by others, and the information contained herein is not applicable to other sites. GeoEngineers structures our services to meet the specific needs of our clients. For example, a geotechnical or geologic study conducted for a civil engineer or architect may not fulfill the needs of a construction contractor or even another civil engineer or architect that are involved in the same project. Because each geotechnical or geologic study is unique, each geotechnical engineering or geologic report is unique, prepared solely for the specific client and project site. Our report is prepared for the exclusive use of our Client. No other party may rely on the product of our services unless we agree in advance to such reliance in writing. This is to provide our firm with reasonable protection against open-ended liability claims by third parties with whom there would otherwise be no contractual limits to their actions. Within the limitations of scope, schedule and budget, our services have been executed in accordance with our Agreement with the Client and generally accepted geotechnical practices in this area at the time this report was prepared. This report should not be applied for any purpose or project except the one originally contemplated. A Geotechnical Engineering or Geologic Report Is Based on a Unique Set of Project-specific Factors This report has been prepared for the VMC FY 2017 Parking Garage Project in Renton, Washington. GeoEngineers considered a number of unique, project-specific factors when establishing the scope of services for this project and report. Unless GeoEngineers specifically indicates otherwise, do not rely on this report if it was: ■ not prepared for you, ■ not prepared for your project, ■ not prepared for the specific site explored, or ■ completed before important project changes were made. For example, changes that can affect the applicability of this report include those that affect: ■ the function of the proposed structure; ■ elevation, configuration, location, orientation or weight of the proposed structure; 1 Developed based on material provided by GBA, GeoProfessional Business Association; www.geoprofessional.org. August 2, 2016 | Page E-1 File No. 2202-024-00 ■ composition of the design team; or ■ project ownership. If important changes are made after the date of this report, GeoEngineers should be given the opportunity to review our interpretations and recommendations and provide written modifications or confirmation, as appropriate. Subsurface Conditions Can Change This geotechnical or geologic report is based on conditions that existed at the time the study was performed. The findings and conclusions of this report may be affected by the passage of time, by manmade events such as construction on or adjacent to the site, or by natural events such as floods, earthquakes, slope instability or groundwater fluctuations. Always contact GeoEngineers before applying a report to determine if it remains applicable. Most Geotechnical and Geologic Findings Are Professional Opinions Our interpretations of subsurface conditions are based on field observations from widely spaced sampling locations at the site. Site exploration identifies subsurface conditions only at those points where subsurface tests are conducted or samples are taken. GeoEngineers reviewed field and laboratory data and then applied our professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ, sometimes significantly, from those indicated in this report. Our report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions. Geotechnical Engineering Report Recommendations Are Not Final Do not over-rely on the preliminary construction recommendations included in this report. These recommendations are not final, because they were developed principally from GeoEngineers’ professional judgment and opinion. GeoEngineers’ recommendations can be finalized only by observing actual subsurface conditions revealed during construction. GeoEngineers cannot assume responsibility or liability for this report's recommendations if we do not perform construction observation. Sufficient monitoring, testing and consultation by GeoEngineers should be provided during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not earthwork activities are completed in accordance with our recommendations. Retaining GeoEngineers for construction observation for this project is the most effective method of managing the risks associated with unanticipated conditions. A Geotechnical Engineering or Geologic Report Could Be Subject to Misinterpretation Misinterpretation of this report by other design team members can result in costly problems. You could lower that risk by having GeoEngineers confer with appropriate members of the design team after submitting the report. Also retain GeoEngineers to review pertinent elements of the design team's plans and specifications. Contractors can also misinterpret a geotechnical engineering or geologic report. Reduce that risk by having GeoEngineers participate in pre-bid and preconstruction conferences, and by providing construction observation. August 2, 2016 | Page E-2 File No. 2202-024-00 Do Not Redraw the Exploration Logs Geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation of field logs and laboratory data. To prevent errors or omissions, the logs included in a geotechnical engineering or geologic report should never be redrawn for inclusion in architectural or other design drawings. Only photographic or electronic reproduction is acceptable, but recognize that separating logs from the report can elevate risk. Give Contractors a Complete Report and Guidance Some owners and design professionals believe they can make contractors liable for unanticipated subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems, give contractors the complete geotechnical engineering or geologic report, but preface it with a clearly written letter of transmittal. In that letter, advise contractors that the report was not prepared for purposes of bid development and that the report's accuracy is limited; encourage them to confer with GeoEngineers and/or to conduct additional study to obtain the specific types of information they need or prefer. A pre-bid conference can also be valuable. Be sure contractors have sufficient time to perform additional study. Only then might an owner be in a position to give contractors the best information available, while requiring them to at least share the financial responsibilities stemming from unanticipated conditions. Further, a contingency for unanticipated conditions should be included in your project budget and schedule. Contractors Are Responsible for Site Safety on Their Own Construction Projects Our geotechnical recommendations are not intended to direct the contractor’s procedures, methods, schedule or management of the work site. The contractor is solely responsible for job site safety and for managing construction operations to minimize risks to on-site personnel and to adjacent properties. Read These Provisions Closely Some clients, design professionals and contractors may not recognize that the geoscience practices (geotechnical engineering or geology) are far less exact than other engineering and natural science disciplines. This lack of understanding can create unrealistic expectations that could lead to disappointments, claims and disputes. GeoEngineers includes these explanatory “limitations” provisions in our reports to help reduce such risks. Please confer with GeoEngineers if you are unclear how these “Report Limitations and Guidelines for Use” apply to your project or site. Geotechnical, Geologic and Environmental Reports Should Not Be Interchanged The equipment, techniques and personnel used to perform an environmental study differ significantly from those used to perform a geotechnical or geologic study and vice versa. For that reason, a geotechnical engineering or geologic report does not usually relate any environmental findings, conclusions or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Similarly, environmental reports are not used to address geotechnical or geologic concerns regarding a specific project. August 2, 2016 | Page E-3 File No. 2202-024-00 Biological Pollutants GeoEngineers’ Scope of Work specifically excludes the investigation, detection, prevention or assessment of the presence of Biological Pollutants. Accordingly, this report does not include any interpretations, recommendations, findings, or conclusions regarding the detecting, assessing, preventing or abating of Biological Pollutants and no conclusions or inferences should be drawn regarding Biological Pollutants, as they may relate to this project. The term “Biological Pollutants” includes, but is not limited to, molds, fungi, spores, bacteria, and viruses, and/or any of their byproducts. If Client desires these specialized services, they should be obtained from a consultant who offers services in this specialized field. August 2, 2016 | Page E-4 File No. 2202-024-00 Have we delivered World Class Client Service? Please let us know by visiting www.geoengineers.com/feedback.