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Report N aiasoi°00/t, Geotechnucal E n ineerin Report g g p Proposed AutoZone Store 3756 Tigard, Oregon Updated April 15, 2010 Project No. 82095068 Prepared for: AutoZone, Inc. Memphis, Tennessee Prepared by: Terracon Consultants, Inc. Portland, Oregon (30p20k -mi (oc . OFFICE 11111 ail r acon r ,.. - ' - x p gfficesBNat�a x Established ih 1965 ` Emplo onw , ° terracfl com < Geotechnical 8 Environmental EIB Construction Materials ® Facilities April 15, 2010 AutoZone, Inc. 123 South Front Street Memphis, Tennessee 38103 Attn: Mr. Trey Smallwood P: 901 - 495 -7956 F: 901 - 495 -8300 Re: Geotechnical Engineering Report - UPDATED Proposed AutoZone Store 3756 Tigard, Oregon Terracon Project No. 82095068 Dear Mr. Smallwood: Terracon Consultants, Inc. (Terracon) has completed the geotechnical engineering services for the above referenced project. This study was performed in general accordance with our proposal number P82090096 dated July 22, 2009. This report is an update to our original report dated August 5, 2009, and is prepared in general accordance with AutoZone Purchase Order No. 62054 dated September 3, 2009, and presents the findings of the subsurface exploration and provides geotechnical recommendations concerning earthwork and the design and construction of foundations and floor slabs for the proposed project. We appreciate the opportunity to be of service to you on this project. If you have; any questions concerning this report, or if we may be of further service, please contact us. <z's'a. ";_'' Sincerely, f a r Terracon Consultants, Inc. 1 "• 47: t r � J: y F° David A. aB ska, Ph.D., P.E., C.E.G. Eric J. Lim, PE, GE r = phi/2 to Senior Consultant Geotechnical Depai men 4 Manager Enclosures cc: 2 - Above 1 - File Terracon Consultants, Inc. 12400 SE Freeman Way, Suite 102 Portland, Oregon 97222 P (503] 659 3281 F [503] 659 1287 terracon.com �4..; °°n:;- r �,,; -. 4 . 9� - �,°-n. r ,�.,c --.x�w a ly''" - t s ^,{4. ° , G e o t etc nt cta ' 111 a E n�u°fi r4 otn(mre;n t a�I Cidrn o f "r utctt i M ait e9"r2raaal s ; U 'Y 1 TABLE OF CONTENTS Page EXECUTIVE SUMMARY 1.0 INTRODUCTION 1 2.0 PROJECT INFORMATION 1 2.1 Project Description 1 2.2 Site Location and Description 2 3.0 SUBSURFACE CONDITIONS 2 3.1 Geology 2 3.2 Typical Profile 3 3.3 Groundwater 3 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION 4 4.1 Geotechnical Considerations 4 4.2 Seismic Considerations 4 4.2.1 Design Recommendations 4 4.2.2 Seismic Hazards 5 4.2.3 Liquefaction Analysis 5 4.3 Foundation Support Alternatives 6 4.3.1 Aggregate Pier Ground Improvements 7 4.3.2 Earthquake Drains 8 4.3.3 Rigid Shallow Foundations with Seismic Ties 8 '4.4 Earthwork 9 4.4.1 Compaction Requirements 10 4.4.2 Grading and Drainage 10 4.4.3 Construction Considerations 11 4.5 Floor Slab 12 4.5.1 Design Recommendations 12 4.5.2 Construction Considerations 12 4.6 Pavements 13 4.6.1 Design Recommendations 13 4.6.2 Construction Considerations 14 5.0 GENERAL COMMENTS 15 APPENDIX A — FIELD EXPLORATION Site and Exploration Plan Boring and CPT Logs Field Exploration Description APPENDIX B — LABORATORY TESTING Laboratory Test Data APPENDIX C — SUPPORTING DOCUMENTS General Notes Unified Soil Classification 7 i Geotechnical Engineering Report - UPDATED 1 Proposed AutoZone Store 3756 ® Tigard, Oregon April 15, 2010 D Terracon Project No. 82095068 EXECUTIVE SUMMARY A geotechnical engineering report has been completed for the investigation for the proposed AutoZone Store 3756 proposed at 13405 SW Pacific Highway approximately 500 feet southwest of the intersection of SW Park Street in Tigard, Oregon. Seven borings, designated B -1 through B -7, were completed to depths ranging between approximately 111/2 to 24 feet below the existing ground surface (bgs) within the proposed building area and parking areas locations. One Cone Penetration Test (CPT), designated CPT -1, was also conducted to a depth of approximately 45 feet bgs within the proposed building area. This report specifically addresses the recommendations for the proposed building. Based on the information obtained from our subsurface exploration, the site can be developed for the proposed project. The following geotechnical considerations were identified: • Loose, saturated sand and non - plastic silt soils were encountered in the explorations and these soils are considered susceptible to liquefaction during a seismic event. Seismic related settlements between 4 and 10 inches are estimated. The 2006 International Building Code, Table 1613.5.2 IBC seismic design classification for this site is F. Deep foundations, ground improvements (such as aggregate piers), or earthquake drains would be required to reduce seismic related settlements to tolerable amounts. • If the owner accepts the risks of excessive seismic settlements, the building can be designed for life- safety only over a rigid shallow foundation with seismic ties. This type of construction is meant to prevent collapse and may not be operable or repairable after a significant earthquake. • On -site native soils consist of fine - grained soils that would only be considered suitable as general engineered fill during extended periods of dry weather. Imported granular fill may be required for structural fill placed below the structure. • The near - surface native soils are typically fill soils consisting of stiff and medium dense sandy silt. We recommend a minimum 12 -inch thick granular base course be placed below building slab. • The existing pavements are not considered suitable for reuse for the new development. We recommend the new pavement section include a geotextile fabric placed over the fine - grained subgrade and below the base course. Close monitoring of the construction operations discussed herein will be critical in achieving the design subgrade support. Therefore, we recommend that Terracon be retained to monitor this portion of the work. This summary should be used in conjunction with the entire report for design purposes. It should be recognized that details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. The section titled GENERAL COMMENTS should be read for an understanding of the report limitations. Reliable Responsive El Convenient fa Innovative 1 GEOTECHNICAL ENGINEERING REPORT PROPOSED AUTOZONE STORE 3756 TIGARD, OREGON Project No. 82095068 April 15, 2010 1.0 INTRODUCTION A geotechnical engineering report has been completed for the investigation for the proposed AutoZone Store 3756 Tigard planned at a site located at 13405 SW Pacific Highway south west of the intersection of SW Park Street in Tigard, Oregon. Seven borings, designated B -1 through B -7, were completed to depths ranging between approximately 11%2 to 24 feet below the existing ground surface (bgs) within the proposed building area and parking areas locations. One Cone Penetration Test (CPT), designated CPT -1, was also conducted to a depth of approximately 45 feet bgs within the proposed building area. The CPT exploration included collection of shear wave velocity testing and pore pressure dissipation data. This report specifically addresses the recommendations for the proposed building. Logs of the borings, CPT plots, along with a Site and Exploration Plan are included in Appendix A of this report. The purpose of these services is to provide information and geotechnical engineering recommendations relative to: Ea subsurface soil conditions foundation design and construction groundwater conditions a floor slab design and construction earthwork ® seismic considerations pavement design and construction 2.0 PROJECT INFORMATION 2.1 Project Description ITEM j DESCRIPTION Site layout See Appendix A, Figure 1: Site and Exploration Plan Building' 6,786 square foot single story structure. Masonry (Prototype 65W) Building construction steel bar joist roof, and slab -on -grade floor. Finished floor elevation i Unknown at the time that this report was prepared. Interior Columns: 37 -75 kips Maximum Toads Perimeter Columns: 20 -50 kips Walls: 1.2 - 3.0 klf Reliable Responsive a Convenient o Innovative 1 Geotechnical Engineering Report lierracon Proposed AutoZone Store 3756 o Tigard, Oregon April 15, 2010 in Terracon Project No. 82095068 ITEM DESCRIPTION Floor Slab: 100 psf Maximum allowable settlement 1 -inch total settlements, 'A -inch differential settlement (both related to static settlements) Grading Not known, maximum cut and fill depths assumed to be on the order of 2 feet Cut and fill slopes none anticipated 1. Project information based on AutoZone Geotechnical Design Criteria, Rev. 06 -05 -09 2.2 Site Location and Description ITEM I DESCRIPTION The proposed project is planned at 13405 SW Pacific Location Highway approximately 500 feet southwest of the intersection of SW Park Street in Tigard, Oregon. Existing improvements A vacant restaurant building and surrounding asphalt parking lot occupy the site. Existing building with asphalt parking lot. Asphalt pavements observed to have significant areas of "alligator cracking" in Current ground cover drive lanes and area of previous asphalt reconstruction patches. Landscaping islands with concrete curbs are located along the southwest face of the building and adjacent to SW Pacific Highway. Existing topography Site has between 2 and 4 feet of grade changes throughout existing parking lot to drain stormwater to catch basins. 3.0 SUBSURFACE CONDITIONS 3.1 Geology The regional geology of the site area was reviewed in the Earthquake- Hazard Geology Maps of the Portland Metropolitan Area, Oregon: Oregon Department of Geology and Mineral Industries Open File Report 0- 90 -2 The project site area is located within the Beaverton, Oregon Quadrangle Map (0r090_2f), and is classified as Qff, fine - grained facies. These deposits are described as crudely to complexly layered, poorly consolidated medium sand and silt, deposited by glacial outburst flooding. The map indicates the thickness of these deposits is on the order of about 30 to 60 feet. The subsurface conditions as disclosed by the borings confirmed the presence and thickness of silt soils as described on the geologic map. 1 Open File Report 0 -90 -2, Beaverton Quadrangle, Oregon - Washington Co., 7.5 Minute Series (Topographic), 1984 Reliable o Responsive o Convenient ❑ Innovative 2 ' 1 Geotechnical Engineering Report irerracon Proposed AutoZone Store 3756 ® Tigard, Oregon April 15, 2010 Terracon Project No. 82095068 3.2 Typical Profile Based on the results of the borings and cone penetration testing, subsurface conditions on the project site can be generalized as follows: Description Approximate Depth to Material Encountered Consistency /Density Bottom of Stratum (feet) 2 inches to 3 inches Existing 1 /2 to 1'/ Asphalt over Pavement N/A Section 3 to 11 inches Gravel Base Course Fill j 1 to 5'/ Sandy Silt and Silty Sand Stiff and Medium Dense Sandy Silt 7 to 10 feet Sandy Silt to Clayey Silt Soft to Stiff Silty Sand 30 feet Silty Sand Loose to Very Loose Clayey Silt 40 feet Clayey Silt to Sandy Silt Very Stiff to Hard' Sandy Silt >45 feet Sandy Silt to Clayey Silt Very Stiff to Hard' ' Based on CPT to SPT correlations. Conditions encountered at each exploration location are indicated on the individual exploration logs. Stratification boundaries on the Togs represent the approximate location of changes in soil types; in -situ, the transition between materials may be gradual. Details for each of the explorations can be found on the logs in Appendix A of this report. 3.3 Groundwater The boreholes were observed while drilling and after completion for the presence and level of groundwater. In addition, delayed water levels were also obtained in some borings. The water levels observed are noted on the attached boring logs, and are summarized below. Boring Number Depth to groundwater Depth to groundwater while drilling, ft. after boring, ft. B -1 I 9 12 B -2 j 10 12 B -3 I 11 12 B -4 10'/2 12 B -5 10 10 B -6 1 ( 5 B -7 11 Borehole Caved Reliable o Responsive ® Convenient Innovative 3 Geotechnical Engineering Report irerracon Proposed AutoZone Store 3756 a Tigard, Oregon April 15, 2010 a Terracon Project No. 82095068 Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the structure may be higher or lower than the levels indicated on the boring Togs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project. 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION 4.1 Geotechnical Considerations The soil exploration data and laboratory test results were evaluated to develop recommendations for the site preparation and for the design and construction of foundations and floor slabs for the proposed building. The primary geotechnical consideration for development of this site is the potential for seismic related settlements to exceed typical design tolerances due to the presence of potentially liquefiable soils at the site. The 2006 International Building Code (IBC) requires that liquefaction analyses be completed assuming a substantial earthquake with associated ground accelerations that are provided in the IBC. The IBC seismic design is based on life safety with the intent of preventing building collapse during such a design earthquake. It is not the intent of the IBC to require a building to be in an operable condition after such event. The Owner should understand that the building may not be in an operational condition after a design earthquake and significant repair or even demolition and reconstruction might be required. We recommend the owner and design team develop allowable seismic settlement criteria for this site based on tolerable settlements that would maintain life safety and also meet owner expectation for building performance subsequent to a design level seismic event. 4.2 Seismic Considerations 4.2.1 Design Recommendations Code Used Site Classification 2006 International Building Code (IBC) F 2.3 Mapped Spectral Acceleration for 0.930 Short Periods, S Mapped Spectral Acceleration for a 0.336 1- second period, S Reliable a Responsive a Convenient Innovative 4 t i Geotechnical Engineering Report �� Proposed AutoZone Store 3756 a Tigard, Oregon April 15, 2010 a Terracon Project No. 82095068 Code. Used Site Classification 1. In general accordance with the 2006 International Building Code, Table 1613.5.2. 2. The 2006 International Building Code (IBC) requires a site soil profile determination extending a depth of 100 feet for seismic site classification. The current scope requested does not include the required 100 foot soil profile determination. Explorations for the building extended to a maximum depth of approximately 45 feet. 3. Per 2006 IBC, Table 1613.5.2, any profile containing soils vulnerable to potential failure or collapse under seismic loading such as liquefiable soils. As discussed later in this report, the site soils are liquefiable; consequently, the Site Class is F. However, Section 20.3.1 of ASCE 7 -05 allows site coefficients Fa and Fv to be determined assuming that liquefaction does not occur for structures with fundamental periods of vibration less than 0.5 second. Based on the results of the shear wave velocity testing, Site Class D may be used to determine the values of Fa and Fv in accordance with Section 1613.5.2 of the 2006 IBC. 4.2.2 Seismic Hazards Seismic hazards resulting from earthquake motions can include slope instability, liquefaction, and surface rupture due to faulting or lateral spreading. Liquefaction is the phenomenon wherein soil strength is dramatically reduced when subjected to vibration or shaking. Liquefaction generally occurs in loose sand or non - plastic silt deposits that are below the water table. Groundwater was typically encountered in borings at depths ranging from 9 to 12 feet. It is our opinion, based on the site geology and the subsurface conditions encountered in our borings, that the risks associated with liquefaction are high. Since the project site is not situated • in close proximity to free slopes, the risk associated with slope instability and lateral spread is considered low. We reviewed the USGS Earthquake Hazards Program Quaternary Faults and Folds Database available online ( http: // earthquake. usqs. qov /regional /gfaults /usmap.php). The nearest faults to the project site are the Canby - Molalla fault zone, approximately 3/4 mile southwest of the project site. According to this source, this fault zone consists of a linear series of northeast trending, discontinuous aeromagnetic anomalies beneath sediments that fill the northern Willamette River basin and that are buried by Missoula flood deposits, as encountered in the explorations. These faults are in the slip rate category of less than 0.2 mm /year. Based on the information described above, we estimate that the risk associated with surface rupture at the site is low. 4.2.3 Liquefaction Analysis Liquefaction is the phenomenon where saturated soils develop high pore water pressures during seismic shaking and lose their strength characteristics. This phenomenon generally Reliable a Responsive a Convenient a Innovative 5 Geotechnical Engineering Report err Proposed AutoZone Store 3756 ® Tigard, Oregon April 15, 2010 0 Terracon Project No. 82095068 occurs in areas of high seismicity, where groundwater is shallow and loose granular soils or relatively non - plastic fine grained soils are present. Saturated loose to very loose silty sand soils were encountered in the borings below depths of about 7A to 10 feet bgs and extended to the bottom of the borings. A supplemental cone penetrometer test (CPT) with seismic shear wave velocities was performed down to approximately 45 feet bgs to further evaluate the liquefaction potential of the site. As part of this geotechnical evaluation, we performed a site- specific liquefaction analysis using the methods based on empirical methods originally developed by Seed and Idriss and subsequently modified by others. The latest recommended procedures were presented by Idriss and Boulanger (2008). In our analysis, the CPT data was used to calculate the liquefaction resistance of the soils based on correlations presented in the Idriss and Boulanger monograph. The peak ground acceleration and moment magnitude used in the analysis were based on IBC derived ground motions for the design earthquake. Using the 2006 IBC seismic parameters, we computed safety factors against liquefaction for the various soil layers below the water table encountered at the time of our exploration. For the groundwater at 12 feet bgs, as encountered in our borings, the potential for liquefaction of the loose sand and non - plastic site soils from about 12 feet bgs to the maximum explored depth of about 45 feet is considered to be high and we estimate liquefaction- induced settlements of 4 to 10 inches at the ground surface. 4.3 Foundation Support Alternatives Potential liquefaction due to a design level seismic event is expected to result in excessive seismic - related settlements of the structure. The following alternatives could be considered to support the structure and or mitigate liquefaction at the site. n Deep pile foundations and structurally support floor slab; ® Aggregate Pier / Stone Column Ground Improvements and conventional shallow foundations; • Earthquake Drains with limited overexcavation and replacement for shallow foundations; Shallow footings and slab -on -grade with rigidly connected footings with seismic ties. Deep foundations would not address settlements below the floor slab. Therefore, a structural floor slab would also be necessary to provide positive support for the structure. We anticipate that this alternative would be the most costly alternative, and we anticipate adequate performance from the ground improvement alternatives. Therefore, we have not provided recommendations for pile foundations in this report. Rammed aggregate piers (such as Geopier®) or stone column ground improvement techniques are also feasible foundation support alternatives and should provide suitable mitigation of liquefaction- induced settlements Reliable a Responsive 0 Convenient ® Innovative 6 • Geotechnical Engineering Report �� Proposed AutoZone Store 3756 Tigard, Oregon April 15, 2010 0 Terracon Project No. 82095068 when designed and constructed properly. If the owner is willing to accept the risk of excessive liquefaction - induced settlements and possible demolition of the building after a significant earthquake, then the building may be designed for a rigid foundation consisting of shallow spread footings with seismic ties designed to prevent collapse to satisfy life- safety requirements of the IBC. This alternative would represent the least cost option. 4.3.1 Aggregate Pier Ground Improvements Based on the presence of liquefaction susceptible soils encountered in the borings, one alternative for support of the structure would be ground improvement of the loose granular soils in order to provide positive support of foundations and floor slabs. Installation of a system of aggregate piers that extend through loose granular materials could consist of Geopiers® or stone columns. The seismic related settlements would depend on the depth of improvement and grid spacing of the aggregate piers. Geopiers® involves excavating 30- to 36 -inch diameter drilled shafts and backfilling the shafts with crushed aggregate placed in lifts and compacted. Compaction is performed with a patented beveled edge ram, which also helps densify the soils surrounding the shaft, creating a stiffer soil matrix for support of foundations. Typical installations to depths of up to about 20 feet are common. Based on the depth of the loose sand and non - plastic soils encountered in the explorations, we anticipate typical Geopier depths would be on the order of 30 or more feet. Conventional spread footings and reinforced slab -on -grade could then be constructed on top of the Geopier /soil matrix. Engineering design of Geopiers® is proprietary and is typically done on a design /build basis by the licensed Geopier® contractor. Vibro- replacement/compaction stone column construction is accomplished using a down -hole vibratory probe that typically penetrates the ground under its own weight. Stone columns at this site would extend through the fill and loose soils and would need to extend to soils stable against liquefaction. Based on the explorations completed for this project and published geologic literature, it appears that the stone columns would be on the order of 30 feet or more in length. When the probe has penetrated to the design depth, gravel is placed in lifts through a tremie pipe. Each gravel lift is forced into the surrounding soil forming a stone column. Stone columns are also generally designed and constructed by a qualified design -build contractor based upon replacement area, densification, liquefaction, and settlement criteria. The contractor also develops specifications for construction of the stone columns, the diameter and spacing, products to be used, as well as tolerance and acceptance criteria. Conventional spread footings could then be constructed on top of the stone column /soil matrix. Floor slabs are also estimated to settle several inches due to potential liquefaction during a design level seismic event. Floor slab settlement can be reduced by installing aggregate piers below slabs. The pier spacing typically ranges from 5 to 10 feet depending on slab reinforcing and the specified design. With wider spaced piers, a reinforced floor slab may be necessary in Reliable 12 Responsive 0 Convenient 0 Innovative 7 Geotechnical Engineering Report lierracon Proposed AutoZone Store 3756 a Tigard, Oregon April 15, 2010 o Terracon Project No. 82095068 order to span between aggregate pier supports. The slab design and spacing of piers in slab - on -grade areas should be included in the design -build proposals. 4.3.2 Earthquake Drains Additional measures could also be considered to improve the subsurface conditions and reduce potential seismic settlements by either densification of the site soils or providing increased drainage of site soils. Installation of Earthquake Drains in combination with imported structural fill supported foundations could be considered to reduce seismic related settlements. Earthquake drains consist of a high flow capacity prefabricated vertical drain wrapped with a geotextile fabric that is typically 3 inches in diameter. The drain provides a path for the rapid dissipation of earthquake- generated excess pore pressures. Vibratory installation of the earthquake drains can also densify loose sand soils around the drain. The Earthquake Drains are a proprietary system and the design and installation would be completed by the licensed contractor. Earthquake drains alone may not be sufficient to reduce seismic related settlements to tolerable amounts that would prevent life safety with standard foundation construction (i.e. some ground improvement discussed above would be necessary in addition). However, installation of these drains in addition to imported structural fill supported footings could reduce settlements and or improve the performance of the structure during a seismic event. 4.3.3 Rigid Shallow Foundations with Seismic Ties We understand that the proposed building will be in the same location as the existing building, but will have a slightly larger footprint. The borings at the four building corners encountered stiff silt to sandy silt fill soils from 21 to 51 feet. These soils appear to be suitable for support of the proposed structure under static conditions. However, liquefaction- induced settlement may cause displacements of 4 to 10 inches, as previously discussed. We recommend that all footings for the structure be connected together. No isolated footing pads should be planned or constructed. In addition, the footings should be designed such that they would be able to span approximately 8 feet without subgrade support (similar to grade - beams). The intent of these recommendations is driven by life- safety as required by the IBC and to help limit differential settlements, but not to prevent total settlements to the magnitudes discussed previously in this report. In addition, this alternative is not intended to mitigate potential liquefaction settlements occurring due to the design level earthquake and the structure may require repair or even reconstruction for operability after a design -level event. The foundations for this alternative may be designed using the parameters provided in the table below. Foundation parameters for the other alternatives will need to be provided by the design - build contractor based on their proposed scope of work. Reliable 0 Responsive o Convenient o Innovative 8 Geotechnical Engineering Report �� Proposed AutoZone Store 3756 ® Tigard, Oregon April 15, 2010 El Terracon Project No. 82095068 DESCRIPTION ` Column j Wall Net allowable bearing pressure 1 2,000 psf 2,000 psf Bearing soil 2 I Stiff Silt or two feet of structural fill. Minimum dimensions 30 inches 24 inches Approximate total static settlement 3 <1 inch <1 inch Estimated differential Static settlement due <'/2 inch between <1/2 inch over 40 feet to static loads columns 1. The recommended net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation. 2. The minimum depth for bottom of footings 18 inches for exterior footings (frost depth) and 12 inches for interior footings. 3. The foundation settlement will depend upon the variations within the subsurface soil profile, the structural loading conditions, the embedment depth of the footings, the thickness of compacted fill, and the quality of the earthwork operations. The above settlement estimates have assumed that the maximum footing size is 5 feet for column footings and 2 feet for continuous footings. 4.4 Earthwork After removal of the existing structures, the floor slabs, existing foundations and pavements should be broken up and removed completely. In addition, any existing utilities that interfere with the proposed construction should be properly abandoned in -place or removed and the trenches backfilled with granular fill. It is important that the demolition of existing structures be performed with close observation and testing. Ground improvements and footing foundations, floor slabs and pavements will be supported on the new structural fill placed in the demolition excavations. The demolition contractor should be aware of project requirements for backfilling so that removal of these fill materials and replacement under controlled conditions is not necessary upon building construction. Also, any excavations necessary for removal of old structures or utilities should be carefully planned and executed, especially adjacent to existing retaining walls, streets, sidewalks, or utilities. Temporary sheeting, shoring or other earth retention systems may be needed to reduce potential for damage to existing infrastructure. After demolition, the exposed subgrades should be thoroughly observed and tested prior to placement of new fill, construction of pavements or slabs. This testing should include proofrolling the subgrade. Wet or dry material should either be removed or moisture conditioned and recompacted. Loose, dry and low- density soil should be removed or compacted in -place prior to placing fill. We recommend that exposed excavation surfaces be, at a minimum, surface compacted prior to the placement of backfill, additional fill, or structural elements. Reliable E3 Responsive m Convenient o Innovative 9 Geotechnical Engineering Report �� Proposed AutoZone Store 3756 Tigard, Oregon April 15, 2010 a Terracon Project No. 82095068 Engineered fill should meet the following material property requirements: Fill Type 1 USCS Classification Acceptable Location for Placement SP, GP Clean Granular Fill All locations (P200 <5 %) SP, SP -SM, GP, GW, Select Granular Fill SW All locations (P200 <12 %) SP, SM, GP, GM, GW All locations and elevations, except where non -frost Granular Fill (P200 <50 %) susceptible fill is required 1. Controlled, compacted fill should consist of approved materials that are free of organic matter and debris. Frozen material should not be used, and fill should not be placed on a frozen subgrade. A sample of each material type should be submitted to the geotechnical engineer for evaluation. 4.4.1 Compaction Requirements ITEM DESCRIPTION 9- inches or less in loose thickness when heavy, self- propelled compaction equipment is used Fill Lift Thickness 4 to 6 inches in loose thickness when hand - guided equipment (i.e. jumping jack, plate compactor, etc.) is used Compaction Requirements 95% of the materials maximum Proctor dry density (ASTM D 1557) Moisture Content Granular Material within ±2 percent of optimum moisture content as determined by ASTM D 1557 1. We recommend that engineered fill be tested for moisture content and compaction during placement. Should the results of the in -place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved. 4.4.2 Grading and Drainage Final surrounding grades should be sloped away from the structure on all sides to prevent ponding of water. Gutters and downspouts that drain water a minimum of 5 feet beyond the footprint of the proposed structure is recommended. This can be accomplished through the use of splash - blocks, downspout extensions, and flexible pipes that are designed to attach to the end of the downspout. Flexible pipe should only be used if it is daylighted in such a manner that it gravity - drains collected water. Splash- blocks should also be considered below hose bibs and water spigots. Reliable Responsive a Convenient a Innovative 10 i Geotechnical Engineering Report lierracon Proposed AutoZone Store 3756 a Tigard, Oregon April 15, 2010 a Terracon Project No. 82095068 4.4.3 Construction Considerations There is existing fill in the building pad area, likely placed as structural fill during construction of the existing building. The condition of the fill as encountered in the explorations appears to be suitable for the allowable design bearing capacity recommended. However, variations may exist in the condition of the fill, especially after disturbed by demolition activities. We recommend that a qualified owner's representative assess the foundation subgrades at the time of construction for their suitability to support the foundation Toads. Loose or soft to medium stiff soils should be removed and replaced with structural fill. Although the exposed subgrade is anticipated to be relatively stable upon initial exposure, unstable subgrade conditions could develop during general construction operations, particularly if the soils are wetted and /or subjected to repetitive construction traffic. Due to the fine - grained nature of the soil, subgrade disturbance may be reduced by placing a working mat of granular fill over exposed subgrades. Upon completion of filling and grading, care should be taken to maintain the subgrade moisture content prior to construction of floor slabs and pavements. Construction traffic over the completed subgrade should be avoided to the extent practical. The site should also be graded to prevent ponding of surface water on the prepared subgrades or in excavations. If the subgrade should become saturated, frozen, desiccated, or disturbed, the affected material should be removed or these materials should be scarified, moisture conditioned, and recompacted prior to floor slab and pavement construction. As a minimum, all temporary excavations should be sloped or braced as required by Occupational Health and Safety Administration (OSHA) regulations to provide stability and safe working conditions. Temporary excavations will probably be required during grading operations. The grading contractor, by his contract, is usually responsible for designing and constructing stable, temporary excavations and should shore, slope or bench the sides of the excavations as required, to maintain stability of both the excavation sides and bottom. All excavations should comply with applicable local, state and federal safety regulations, including the current OSHA Excavation and Trench Safety Standards. The geotechnical engineer and /or their representative should be retained during the construction phase of the project to observe earthwork and to perform necessary tests and observations during subgrade preparation; proof - rolling; placement and compaction of controlled compacted fills; backfilling of excavations into the completed subgrade, and just prior to construction of building floor slabs. Reliable a Responsive a Convenient G Innovative 11 Geotechnical Engineering Report 1 rerracon Proposed AutoZone Store 3756 ® Tigard, Oregon April 15, 2010 o Terracon Project No. 82095068 4.5 Floor Slab 4.5.1 Design Recommendations ITEM DESCRIPTION 12 -inch compacted granular fill zone and special Floor slab support subgrade preparation, is required 125 pounds per square inch per in (psi /in) for point Modulus of subgrade reaction j loading conditions Aggregate base course /capillary break ° 6 inches of free draining granular material, tested for a capillary rise less than 2 inches. 1. Floor slab subgrade is recommended to consist of Granular Fill. 2. Ground improvement techniques, such as aggregate piers or earthquake drains, may alter the modulus of subgrade reaction and require additional reinforcement or other requirements per the design -build contractor. 3. We recommend subgrades be maintained in a relatively moist condition until floor slabs and pavements are constructed. If the subgrade should become desiccated prior to construction of floor slabs and pavements, the affected material should be removed or the materials scarified, moistened, and recompacted. Upon completion of grading operations in the building areas, care should be taken to maintain the recommended subgrade moisture content and density prior to construction of the building floor slabs. 4. The floor slab design should include a capillary break, comprised of free - draining, compacted, granular material, such as ODOT gradation Section 02630 Dense graded aggregates 3/4" - 0, at least 6 inches thick. Free - draining granular material should have less than 5 percent fines (material passing the #200 sieve) and be tested for a capillary rise of less than 2 inches. Where appropriate, saw -cut control joints should be placed in the slab to help control the location and extent of cracking. For additional recommendations refer to the ACI Design Manual. Joints or any cracks in pavement areas that develop should be sealed with a water- proof, non - extruding compressible compound specifically recommended for heavy duty concrete pavement and wet environments. 4.5.2 Construction Considerations On most project sites, the site grading is generally accomplished early in the construction phase. However as construction proceeds, the subgrade may be disturbed due to utility excavations, construction traffic, desiccation, rainfall, etc. As a result, the floor slab subgrade may not be suitable for placement of base rock and concrete and corrective action will be required. We recommend the area underlying the floor slab be rough graded and then thoroughly proofrolled with a loaded tandem axle dump truck prior to final grading and placement of base rock. Particular attention should be paid to high traffic areas that were rutted and disturbed earlier and to areas where backfilled trenches are located. Areas where unsuitable conditions are Reliable o Responsive r Convenient Innovative 12 Geotechnical Engineering Report �� Proposed Auto Store 3756 u Tigard, Oregon April 15, 2010 Terracon Project No. 82095068 located should be repaired by removing and replacing the affected material with properly compacted fill. All floor slab subgrade areas should be moisture conditioned and properly compacted to the recommendations in this report immediately prior to placement of the base rock and concrete. 4.6 Pavements 4.6.1 Design Recommendations Existing pavements present at the site are not considered suitable for reuse for the new store development. Significant areas of the existing drive areas are either "alligator cracked" or have been patched. Although we have not completed an evaluation of the remaining design life of the existing pavements, we anticipate that the pavements would not meet criteria for a 20 -year design life. Pavement areas removed for construction or damaged will require proper subgrade preparation for either reinforced concrete or bituminous pavements. Consideration of concrete pavements is strongly recommended in truck loading and turn around areas. The existing fill may be left beneath pavements; however, we recommend that, at a minimum, the upper 1 foot of the subgrade be scarified, blended, and recompacted prior to the placement of aggregate base or structures. This risk of unforeseen conditions cannot be eliminated without completely removing the existing fill, but can be reduced by performing additional testing and evaluation. Two levels of traffic were provided to us by AutoZone criteria for new pavements to be constructed on the site. Traffic criteria provided for flexible pavement thickness designs include 18 -kip equivalent single axle loads (ESAL's) of 11,279 for light duty, and 30,567 for heavy -duty pavement areas. Listed below are pavement component thicknesses, which may be used as a guide for pavement systems at the site for the traffic classifications stated herein. It should be noted that these systems were derived based on general characterization of the subgrade. No specific testing (such as CBR, resilient modulus test, etc.) was performed for this project to evaluate the support characteristics of the subgrade. Reliable a Responsive a Convenient a Innovative 13 Geotechnical Engineering Report llerracon Proposed AutoZone Store 3756 o Tigard, Oregon April 15, 2010 o Terracon Project No. 82095068 RIGID (CONCRETE) PAVEMENT SYSTEM COMPONENT Material Thickness, Inches Light Duty Heavy Duty Reinforced Concrete 5 6 ODOT Aggregate 4 I 4 Base FLEXIBLE (BITUMINOUS) PAVEMENT SYSTEM COMPONENT Material Thickness, Inches Light Duty Heavy Duty Bituminous 3 1/2 4 Pavement ODOT Aggregate Base 6 8 For areas subject to concentrated and repetitive loading conditions such as dumpster pads, truck delivery docks, and ingress /egress aprons, we recommend using a Portland cement concrete pavement with a thickness of at least 7 inches underlain by at least 4 inches of crushed stone. Prior to placement of the crushed stone the areas should be thoroughly proofrolled. For dumpster pads, the concrete pavement area should be large enough to support the container and tipping axle of the refuse truck. Dumpster areas that are not designed in this manner often experience localized failures due to large wheel loading imposed during waste collection. We recommend that newly constructed pavement sections include a geotextile fabric over the fine - grained subgrade and below the base course to prevent migration of fines into the base course layer. We recommend using a fabric such as Mirafi 600X, or equivalent. Geotextile fabrics, if properly selected and installed, will maintain segregation of the subgrade soil and base course materials. Decreased pavement support will result if the subgrade soils are allowed to migrate upwards into the base course. The use of stabilization fabric will not reduce the necessary base rock thickness, since fabric does not provide structural strength at such depths. 4.6.2 Construction Considerations Long term pavement performance will be dependent upon several factors, including maintaining subgrade moisture levels and providing for preventive maintenance. The following recommendations should be considered the minimum: O Site grading at a minimum 2% grade away from the pavements; Reliable o Responsive r3 Convenient El Innovative 14 Geotechnical Engineering Report lierracon Proposed AutoZone Store 3756 E Tigard, Oregon April 15, 2010 a Terracon Project No. 82095068 • The subgrade and the pavement surface have a minimum 1/4 inch per foot slope to promote proper surface drainage. • Consider appropriate edge drainage and pavement under drain systems, • Install pavement drainage surrounding areas anticipated for frequent wetting (e.g. wash racks) • Install joint sealant and seal cracks immediately, • Seal all landscaped areas in, or adjacent to pavements to minimize or prevent moisture migration to subgrade soils; • Placing compacted, low permeability backfill against the exterior side of curb and gutter. Preventive maintenance should be planned and provided for through an on -going pavement management program. Preventive maintenance activities are intended to slow the rate of pavement deterioration, and to preserve the pavement investment. Preventive maintenance consists of both localized maintenance (e.g. crack and joint sealing and patching) and global maintenance (e.g. surface sealing). Preventive maintenance is usually the first priority when implementing a planned pavement maintenance program and provides the highest return on investment for pavements. Prior to implementing any maintenance, additional engineering observation is recommended to determine the type and extent of preventive maintenance. Portland Cement Concrete (PCC) pavements will require properly designed and constructed joints to provide satisfactory performance. Refer to ACI 330, Guide for Design and Construction of Concrete Parking Lots for information on design of joints for PCC pavements. Construction traffic on the new pavements was not considered in developing the recommended minimum pavement thicknesses. Construction traffic can cause significant damage to partially completed pavement sections. If the new pavements will be subject to traffic by construction equipment/vehicles, the pavement thicknesses should be revised to consider the effects of additional traffic loading. Related civil design factors such as subgrade drainage, shoulder support, cross sectional configurations, surface elevations and environmental factors which will significantly affect the service life must be included in the preparation of the construction drawings and specifications. The above sections should be considered minimum pavement thicknesses and higher traffic volumes and heavy trucks may require thicker pavement sections. 5.0 GENERAL COMMENTS Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon also should be retained to provide observation and testing services during grading, excavation, foundation construction and other earth- related construction phases of the project. Reliable a Responsive ra Convenient o Innovative 15 J 1 Geotechnical Engineering Report lierracon Proposed AutoZone Store 3756 o Tigard, Oregon April 15, 2010 o Terracon Project No. 82095068 The analysis and recommendations presented in this report are based upon the data obtained from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations that may occur between borings, across the site, or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided. The scope of services for this project does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. Terracon has been contracted to perform a Phase I environmental assessment for the project site, and the results of this study are being submitted under a separate cover. This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that changes in the nature, design, or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this report in writing. Reliable o Responsive a Convenient o Innovative 16 APPENDIX A FIELD EXPLORATION APPROXIMATE LOCATION AND EXTENT OF BLDG. TO BE DEMOLISHED FF = 103.4' - -_I - -- PROPOSED BUILDING � �, ( I 60' 10' BACK ENTRANCE TO SW Id PARK STREET —� • L 0 1 l'' ' �' 1 0 30' 03.0 j r F° 1 /F i L14__ -- B-5 I ti - I I A ,� ! 104.5 I 70 I ®i 13-7 I 25' * I I 101.5 A I CPT -1 I 13-4 ilk ,�� 102 - 13 -3 . I _ . . . . 102:5 k I 75 1 \'‘,Y I B-6 ` 1 �, 100.5 CB ( l ?a9' — ---A BENCHMARK 4—_ SW PACIFIC HIGHWAY —.. Legend ED B-1 Approximate Boring Location 103.5 and Surface Elevation, Feet CPT -1 Approximate Cone Penetration Test Location Base Map: Referenced From AutoZone RFP . Documents, Proposed Store 3756 Tigard, and Catch Basin on Pacific Highway Modified by Terracon Consultants Iil Benchmark – Assigned Elevation = 100.0', Terracon Site Datum NOT TO SCALE TERRACON PROJECT NO.: 82095068 4, SITE AND EXPLORATION PLAN 1 i/ Proposed AutoZone Store 3756 13405 SW Pacific Highway Tigard, OR 97223 April 2010 P % LOG OF BORING NO. B -1 Page 1 of 1 CLIENT AutoZone, Inc. SITE 13405 SW Pacific Hwy PROJECT . Tigard, Oregon Proposed AutoZone Store 3756 SAMPLES TESTS O p 1 - o n o DESCRIPTION w ° 1- z __- ce o >_ o! W C z Z Z 0 m' 1 = fn W > Z (n OC W Z CY V) 0_ ~ CO m W O WZ >- Oct w F- w v a 0 a� Q 8 o 0 r o Approx. Surface Elev.: 103.0 ft o S z L Pa m `i o a E 0.25 3" Asphalt over 6 -8" Gravel Base Course 103 — 1 over 102 ;4 ;; FILL: SANDY SILT, brown -gray, stiff, — 1 SS 14 9 26 2500* •• damp — ' • ' •∎∎, 3 100 — 2 SS 18 9 29 2500* SILT, WITH SAND, brown, stiff, damp — • 5 —ML 3 ST 4 32 7.5 95.5 SAND, WITH SILT, brown, loose, moist to _SM 4 SS 15 4 32 LL = 27 wet — PI = 2 - becomes wet 10 _ SM 5 SS 17 5 T. - brown with black mottling 15 —SM 6 SS 16 7 — - becomes medium dense 20 _SM 7 SS 16 13 36 :21.5 81.5 BOTTOM OF BORING i. m Boring advanced using solid stem augers. zb- i- 0 0 Z 0 0 Q x K W F 0 The stratification lines represent the approximate boundary lines *Calibrated Hand Penetrometer between soil and rock types: in -situ, the transition may be gradual. * *140H SPT Cathead N WATER LEVEL OBSERVATIONS, ft BORING STARTED 7 -26 -09 WL SZ 9 WD 1 12.5 AB lierracon BORING COMPLETED 7-26-09 o o WL Y 12 1HR RIG B.R. 160 DRILLER DFE m�WL LOGGED BHS JOB # 82095068 f LOG OF BORING NO. B -2 Page 1 of 1 CLIENT AutoZone, Inc. SITE 13405 SW Pacific Hwy PROJECT Tigard, Oregon Proposed AutoZone Store 3756 SAMPLES TESTS J V Q c F d en DESCRIPTION 2 z = a F ui w w > zw aw _z LL a w Q ~z } 0 a F cn CO w� w o Approx. Surface Elev.: 103.0 ft o S z LcV can in o o a v~i o rri 0.16 2" Asphalt over 10 "Gravel Base Course 103 — „� 1 over 102 •• 1 SS 3 12 9 :•: FILL: SILTY GRAVEL, WITH SAND, —_ ;.;.; b rown, medium dense, damp te 3 100 — 2 SS 11 12 25 •. ❖. FILL: SANDY SILT, TRACE GRAVEL, — A% brown, stiff, damp .» 5 98 — SILT WITH SAND, brown, medium stiff, 5 — ML 3 SS 18 7 28 2000* damp to moist — — ML 4 ST 21 33 88 2500* 3000 9.5 93.5 SILTY SAND, brown, loose, wet SZ 10 — SM 5 SS 17 4 37 t — 15 — SM 6 SS 17 7 32 . 20 — SM 7 SS 17 5 :; •:. — :'. 21.5 81.5 BOTTOM OF BORING m Boring advanced using solid stem augers. 0 0 0 z 0 0 Q K uJ W F 5 The stratification lines represent the approximate boundary lines *Calibrated Hand Penetrometer between soil and rock types: in -situ, the transition may be gradual. * *140H SPT Cathead a WATER LEVEL OBSERVATIONS, ft BORING STARTED 7 -26 -09 WL V- 10 WD 1 12 AB lierracon BORING COMPLETED 7 -26 -09 Fi WL 51 11 5HR RIG B.R. 160 DRILLER DFE m(WL LOGGED BHS JOB # 82095068 d . e LOG OF BORING NO. B -3 Page 1 of 1 CLIENT AutoZone, Inc. SITE 13405 SW Pacific Hwy PROJECT Tigard, Oregon Proposed AutoZone Store 3756 • SAMPLES TESTS 0 d O- DESCRIPTION _ F z = wo W w w Z Z0 CO a H fn m w O Z Li) I- >- OO w o Approx. Surface Elev.: 102.5 ft o S z 'k' Pr, m ' 8 o a r a MI 0.21 2.5" Asphalt over 6 -7" Gravel Base Course 102.5 • 1 over 101.5 * A e FILL: SILT, WITH SAND, dark brown, stiff, — 1 SS 11 13 16 • + • 2.5 damp 100 — SILT, WITH SAND, brown, stiff, damp _ ML 2 ST 18 24 93 3500* _ ML 3 SS 15 10 27 5— _ ML 4 SS 13 9 33 3000* • - becomes medium stiff _ ML 5 SS 15 5 30 LL = 36 — PI =13 10 92.5 SILTY SAND, brown, loose, moist to wet 10 _SM 6 SS 17 4 32 SL _ Y _ - becomes wet 15 _ SM 7 SS 16 5 20 _ SM 8 SS 16 4 — 21.5 81 • BOTTOM OF BORING Boring advanced using solid stem augers. F- 0 0 . 0 0 Q K CL W F The stratification lines represent the approximate boundary lines *Calibrated Hand Penetrometer between soil and rock types: in -situ, the transition may be gradual. * *140H SPT Cathead 0 N N WATER LEVEL OBSERVATIONS, ft BORING STARTED 7 -26 -09 Eg WL V 11 WD T 13 AB 1 r�rr�c ®n BORING COMPLETED 7 -26 -09 o WL 1 12 2HR RIG B.R. 160 DRILLER DFE w m LOGGED BHS JOB # 82095068 LOG OF BORING NO. B-4 Page 1 of 1 CLIENT AutoZone, Inc. SITE 13405 SW Pacific Hwy PROJECT Tigard, Oregon Proposed AutoZone Store 3756 SAMPLES TESTS cO c OC o DESCRIPTION CO i_ z = o � W > zd) o w Z Zz w o Approx. Surface Elev.: 102.0 ft o S z i- l aim ° o a o u In Z o o 0.16 2" Asphalt over 6 -7" Gravel Base Course 102 _ _ 1 over 101 — 1 SS 12 9 21 ••••• FILL: SILT, TRACE SAND, TRACE :4• 2 ROOTHAIRS, dark gray, stiff, damp 99 — ; FILL: SANDY SILT, brown -gray, stiff damp — 2 SS 12 22 • • •;• •• •�•�• ••• — •:•:. 5 , ••••• 5.5 96.5 _ ML 3 SS 16 15 27 SILT, TRACE SAND, brown, stiff, damp — 29 _ ML 4 ST 10 32 89 1500* 8.5 93.5 , ;: SILTY SAND, brown, loose, damp to moist _ SM 5 SS 15 6 30 - becomes wet 5Z 10 _ SM 6 SS 18 6 30 44% 1 — - becomes brown -gray 15 _SM 7 SS 15 7 33 48% - very loose, wet 20 _ SM 8 SS 11 3 31 22% o•': _SM 9 SS 15 3 • 78 — 8 BOTTOM OF BORING 0 0 a Boring advanced using solid stem augers. cc W The stratification lines represent the approximate boundary lines `Calibrated Hand Penetrometer 0 between soil and rock types: in -situ, the transition may be gradual. **140H SPT Cathead N . E WATER LEVEL OBSERVATIONS, ft BORING STARTED 7 -26 -09 WL V 10.5 WD 1 13 AB 1 Yeast ®n BORING COMPLETED 7 -26 -09 o WL Z 12 4HR X RIG B.R. 160 DRILLER DFE W m`WL LOGGED BHS JOB # 82095068 1 LOG OF BORING NO. B -5 Page 1 of 1 CLIENT AutoZone, Inc. SITE 13405 SW Pacific Hwy PROJECT Tigard, Oregon Proposed AutoZone Store 3756 SAMPLES TESTS -J o c o F- 0 0- U DESCRIPTION z cc V) w > zu w zz c m ww O W >- 0 W S z F- a �0 0 a 70) Approx. Surface Elev.: 104.5 ft o S z wm 0.21 2 1/2" Asphalt over 3" Gravel Base Course 104.5 0.5 over 104 — ML 1 SS 13 8 26 SILT, WITH SAND, brown, medium stiff, — damp _ ML 2 SS 15 9 28 2000* - becomes brown -gray — - becomes brown, damp to moist 5 _ ML 3 SS 15 7 29 97 4 SS 17 4 35 SAND, WITH SILT, brown, loose, moist — SM - becomes wet 10 _ SM 5 SS 16 4 :11.5 93 BOTTOM OF BORING Boring advanced using solid stem augers. • 0 0 Z 0 0 uJ W P5 The stratification lines represent the approximate boundary lines `Calibrated Hand Penetrometer between soil and rock types: in -situ, the transition may be gradual. * *140H SPT Cathead WATER LEVEL OBSERVATIONS, ft BORING STARTED 7 -26 -09 WL S? 10 WD L 10 o AB lierracon BORING COMPLETED 7 -26 -09 WL RIG B.R. 160 DRILLER DFE WL LOGGED BHS JOB # 82095068 I 1 LOG OF BORING NO. B -6 Page 1 of 1 CLIENT AutoZone, Inc. SITE 13405 SW Pacific Hwy PROJECT Tigard, Oregon Proposed AutoZone Store 3756 SAMPLES TESTS 0 o 5 O a DESCRIPTION g >- z z W Z z ~ to m W O F z >- w o Approx. Surface Elev.: 100.5 ft o z r uai m 8 o a S c~n mg 0.25 3" Asphalt over 11 -12" Gravel base Course 100.5 — • over S? — 0 ,. t 1.5 99 • SANDY SILT, brown -gray, medium stiff, — ML 1 ST 18 23 103 4000* wet - 3000` — ML 2 SS 15 6 29 2000* 5 ML 3 SS 17 8 32 2500* - becomes brown — 7.5 93 SILTY SAND, brown, loose, wet _SM 4 SS 15 6 34 10 —SM 5 SS 14 6 89 BOTTOM OF BORING Boring advanced using solid stem augers. • 0 0 0 N 0 0 Z O U W F- The stratification lines represent the approximate boundary lines *Calibrated Hand Penetrometer o between soil and rock types: in -situ, the transition may be gradual. **140H SPT Cathead WATER LEVEL OBSERVATIONS, ft BORING STARTED 7 -26 -09 WL �? 1 WD 1 5 3HR ir erseon RIG BORING COMPLETED B.R. 160 DRILLER 7 -26 o WL � � mo L LOGGED BHS JOB # 82095068 • LOG OF BORING NO. B -7 Page 1 of 1 CLIENT AutoZone, Inc. SITE 13405 SW Pacific Hwy PROJECT Tigard, Oregon Proposed AutoZone Store 3756 SAMPLES TESTS 0 o .E o H 0 o DESCRIPTION o - . m F z _ W w z 1-1- t_9 F (1) m w > i w D Ow Fz )- U ce o Ii Approx. Surface Elev.: 101.5 ft o z n w a Q o z t rn � U a E U 0.25 3" Aphalt over 7" Gravel Base Course over 101.5 _ P. Mk'. 1 100.5 SANDY SILT, gray and brown, stiff, damp _ ML 1. SS 9 10 22 - brown to gray mottled, moist _ ML 2 SS 15 13 24 5 96.5 `: ; ;; SILTY SAND, brown, medium dense, 5 _ SM 3 SS 15 10 28 damp — loose, damp to moist _SM 4 SS 18 6 31 - very loose, wet 10 _SM 5 SS 18 3 Q — ..'.11.5 90 BOTTOM OF BORING Boring advanced using solid stem augers. 0 • • 0 0 0 0 0 Q Lx Lx W F tt The stratification lines represent the approximate boundary lines *Calibrated Hand Penetrometer fg 0 between soil and rock types: in -situ, the transition may be gradual. **140H SPT Cathead N R, WATER LEVEL OBSERVATIONS, ft BORING STARTED 7 -26 -09 WL Si 11 WD N/E AB lrerracon BORING COMPLETED 7-26-09 o WL Y RIG B.R. 160 DRILLER DFE W m LOGGED BHS JOB # 82095068 Subsurface Technologies Operator: SAM CPT Date/Time: 9/4/2009 10:22:49 AM Sounding: P -1 (CPT -1) Location: TIGARD AUTO ZONE Cone Used: DSG0683 Job Number: 82095068 Tip Resistance Local Friction Friction Ratio Pore Pressure Diff PP Ratio Soil Behavior Type* Qt TSF Fs TSF Fs /Qt ( %) Pw PSI (Pw- Ph) /Qt ( %) Zone: UBC -1983 0 250 0 5 0 10 -20 100 -20 100 0 12 0 IIl I I II II II II 11 2 l 1 e I 5 r - --i — y - t - r - -H -1) rrr- r -i - - + - r - - +- a:•+ r1ry +r ( iP. 1 111 1 ) 10 - - + --- r -- - t - - - - - -- - - 1 - + -r- '-- 1 L1-4 - - + — 1- r - + n�`'e'i - F ry +r I 1 I i „..,,, 1 3 a0a,. =i I „,„,_:„„.., ;fa riot 20 — - - H-- 1- - - - - -- 4_1 - + -H_ - 1- :- 1 4 +HH 4 - - H „ - -+- Hi - - +- ' . 1 +1- ,, \, mat Depth • 1 k (ft) aIi p 98 25 — H l -_ _ - -_____ -II- -+ -H- 3-11 1-•+i -H- --i 1 -i__ +- _Hi - - + - 1 4-+1 - 1 + 4D ei x 4141: OA I I I ! 30 �f (( 5 ' 1 ' 1 11 I J I �I 1 E k -4-1 ■ V it L y I Q e 40 — — , Yxr # , �I i rIT I r1 fr { asa p F (1pr r J I > 1 I b,9 is _ '� J� 1, h�c��r 45 _ —_ Maximum Depth = 44.95 feet Depth Increment = 0.328 feet El 1 sensitive fine grained 1 4 silty clay to clay 1 7 silty sand to sandy silt 1 10 gravelly sand to sand 2 organic material 5 clayey silt to silty clay ri 8 sand to silty sand rei 11 very stiff fine grained ( *) ® 3 clay 16 sandy silt to clayey silt G 9 sand 1 12 sand to clayey sand ( *) "Soil behavior type and SPT based on data from UBC -1983 s Subsurface Technologies Operator: SAM CPT Date/Time: 9/4/2009 10:22:49 AM Sounding: P -1 (CPT -1) Location: TIGARD AUTO ZONE Cone Used: DSG0683 Job Number: 82095068 Tip Resistance Soil Behavior Type* SPT N* Seismic Delay Seismic Velocity Qt TSF Zone: UBC -1983 60% Hammer (milliseconds) (ft/s) 0 250 0 12 0 50 0 60 0 1200 0 1 1 I 1 I 1 I I I I 1 I t I I 1 . Iiii L 5 — � - 1-------- r-- - + - - -- - a *,,- i- I- t-r+ +r - r+- t- I -1-1-I - -- — 1- -- -1-t-1- - — r- - -t - + -r- ::zitx H7 11 05 630.0525 l I RIP f z 1 10 1________ +____ aria,P ylltrr --1- 1111y___ - - 1 - + - r - - r 1I - r_ , I IL 19.0 584.08 II I sUals nA ¢l C�, tt rt I t Z 4 J t 1 30.27 7673 5565r 20 71 -/-i 1- + +r —+ 111 -1 - -- — 1--- - I - + - r — — I --- 1 - + - r — e p I, fl 1 I 116.9 ;ei Depth -'o ,` , tin 1 — � 25 -------- r - + - --- + +r �+ 1 1 1 — �-- - -- - i - + - r — — 1--- 1 = + - r— 39.8 L 1794.8819 / I C` 3} � 1 I I I 30 4 I + 11 + +r _+ 1-I-I —, 1 + -1-- —� i f 9 1 i 1 I ..1 L` r� I — 47.77 9 36.0236 eitti 6 e 1 35 - - -'�F I - + - - -- _i i +A-I- + + - — I-- 4- + - — I - -I - - t-- WOli 6 6} , � 0. .. " 54.68 133.924 7 +. 40 _ 1_ L - 1.1 +LI- —A- +44 -I-1 -- —~ -- - "4 -l"— —I-' -- -y -t' 1 i I I ti e g L,7R 1 1 1 n rfi A ifn I i ;i ■ , I a ,,ti6rr - i , _11 i 45 �. � � 59.84 Maximum Depth = 44.95 feet Depth Increment = 0.328 feet 0 1 sensitive fine grained E 4 silty clay to clay 0 7 silty sand to sandy silt 0 10 gravelly sand to sand 2 organic material 0 5 clayey silt to silty clay E 8 sand to silty sand El 11 very stiff fine grained ( *) ■ 3 clay • 6 sandy silt to clayey silt - 9 sand II 12 sand to clayey sand ( *) *Soil behavior type and SPT based on data from UBC -1983 ' r Geotechnical Engineering Report - UPDATED �� Proposed AutoZone Store 3756 a Tigard, Oregon April 15, 2010 a Terracon Project No. 82095068 Field Exploration Description The boring and cone penetration test (CPT) locations were selected by AutoZone and marked in the field by Terracon personnel. The approximate boring and CPT locations are indicated on the attached Site and Exploration Plan. Distances from the boring and CPT locations to the reference features shown on the attached diagram are approximate and were measured with a tape. Right angles for the boring and CPT location measurements were estimated. The drill crew obtained the elevations at the boring locations using a surveyor's rod and level. The elevations were referenced to catch basin rim located on the north side of Pacific Highway, as shown on the Site and Exploration Plan. For the purposes of this report, we assigned this benchmark an elevation of 100.0 feet, Terracon site datum. The elevations, rounded to the nearest 1/2 -foot, are shown on the boring logs and Location Diagram. The locations of the borings should be considered accurate only to the degree implied by the means and methods used to define them. The borings were drilled with a trailer- mounted rotary drill rig using continuous flight solid -stem augers to advance the boreholes. Samples of the soil encountered in the borings were obtained using the split barrel sampling procedures, and undisturbed samples were obtained using Shelby tubes. In the split - barrel sampling procedure, the number of blows required to advance a standard 2 -inch O.D. split - barrel sampler the last 12 inches of the typical total 18 -inch penetration by means of a 140 -pound C.M.E. auto - hammer with a free fall of 30 inches, is the standard penetration resistance value (SPT -N). This value is used to estimate the in -situ relative density of cohesionless soils and consistency of cohesive soils. Undisturbed samples were obtained by pushing a 3 -inch outside diameter, seamless steel Shelby tube into the soil using the hydraulic system on the drill rig in accordance with ASTM: D1587. Since the thin wall tube is pushed rather than driven, the sample obtained is considered to be relatively undisturbed. The samples were classified in the field by examining the ends of the tube prior to sealing with plastic caps. The samples were then transported to our laboratory where they were extruded for further classification and laboratory testing. A hammer operated with a cathead and rope SPT hammer was used to advance the split - barrel sampler in the borings performed on this site. A lower efficiency is achieved with a safety hammer operated with a cathead and rope hammer compared to an automatic hammer. This lower efficiency has an appreciable effect on the SPT -N value. The effect of the cathead hammer's efficiency has been considered in the interpretation and analysis of the subsurface information for this report. The samples from the borings were tagged for identification, sealed to reduce moisture loss, and taken to our laboratory for further examination, testing, and classification. Information provided on Exhibit A -1 • the boring logs attached to this report includes soil descriptions, consistency evaluations, boring depths, sampling intervals, and groundwater conditions. The borings were backfilled with bentonite per applicable state regulations. A field log of each boring was prepared by the Field Geotechnical Engineer. These logs included visual classifications of the materials encountered during drilling as well as the engineers' interpretation of the subsurface conditions between samples. Final boring logs included with this report represent the engineer's interpretation of the field logs and include modifications based on laboratory observation and tests of the samples. Subsurface Technologies, Inc., an independent firm working under subcontract to Terracon, performed Cone Penetration Test (CPT) at the site on September 4, 2009. The CPT probes were advanced using a truck mounted rig. A CPT is completed by pushing a probe (Type DSG0683) with a conical tip into the soil at a constant rate, and measuring the penetration resistance of the cone and the friction resistance on a friction sleeve. A continuous log of the probe hole was obtained. Soil descriptions presented on the CPT log are based on interpretations of the cone data at specific exploration locations. Pore water pressure dissipation and seismic tests were performed throughout the depths tested. The probe hole was backfilled with bentonite slurry after completion. Results of the CPT are presented in this appendix. a APPENDIX B LABORATORY TESTING n . Geotechnical Engineering Report - UPDATED 1 r�rr�c ®n Proposed AutoZone Store 375613 Tigard, Oregon April 15, 2010 o Terracon Project No. 82095068 Laboratory Testing As a part of the laboratory testing program, the soil samples were classified in the laboratory based on visual observation, texture, plasticity, and the limited laboratory testing described above. The soil descriptions presented on the boring logs for native soils are in accordance with our enclosed General Notes and Unified Soil Classification System (USCS). The estimated group symbol for the USCS is also shown on the boring logs, and a brief description of the Unified System is included in this report. Moisture content tests, Atterberg limits, 200 wash, and dry unit weights were completed on select thin - walled tube samples in the laboratory. The unconfined compressive strength of moderately cohesive soil samples were estimated using a hand penetrometer. Results of the laboratory tests are presented on the boring logs. • , w Sheet 1 of 1 Depth Liquid Plastic Plasticity Maximum %< #200 USCS Water Dry Unit Satur- Void Borehole Size Class- Content Weight ation ft Limit Limit Index Sieve o o) Ratio (mm) ification (/o ) (p cf) (/o B -1 1.0 26.4 B -1 2.5 29.4 B -1 5.0 32.1 B -1 7.5 27 25 2 32.0 B -1 20.0 36.0 B -2 1.0 9.3 B -2 2.5 25.0 B -2 5.0 27.7 B -2 7.5 32.7 88.1 B -2 10.0 36.8 B -2 15.0 31.7 B -3 1.0 16.4 B -3 2.5 23.9 92.9 B -3 4.0 27.0 B -3 5.5 32.8 B -3 7.5 36 23 13 29.6 B -3 10.0 31.9 B-4 1.0 20.6 B-4 2.5 22.2 B-4 5.0 27.1 B-4 6.0 29.1 B-4 7.5 31.9 89.1 B-4 8.5 30.1 B-4 10.0 0.075 44 29.8 B-4 15.0 0.075 48 33.0 B -4 20.0 0.075 22 31.3 B -5 0.5 26.1 B -5 2.0 28.2 B -5 5.0 28.9 B -5 7.0 34.5 B -6 1.5 23.4 103.1 B -6 3.5 29.4 B -6 5.0 32.1 B -6 7.5 33.8 B -7 1.0 21.7 B -7 2.5 23.8 H B -7 5.0 27.6 z 8 B -7 7.5 31.3 0 0 w W N 0 (7 0 N 01 SUMMARY OF LABORATORY RESULTS Project: Proposed AutoZone Store 3756 1 lrerracon Site: 13405 SW Pacific Hwy Tigard, Oregon Q Job #: 82095068 J 0 Date: 8 -5 -09 APPENDIX C SUPPORTING DOCUMENTS • GENERAL NOTES DRILLING & SAMPLING SYMBOLS: SS: Split Spoon -1 3 /8" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger ST: Thin - Walled Tube - 2" O.D., unless otherwise noted PA: Power Auger RS: Ring Sampler - 2.42" I.D., 3" O.D., unless otherwise noted HA: Hand Auger DB: Diamond Bit Coring - 4 ", N, B RB: Rock Bit BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary The number of blows required to advance a standard 2 -inch O.D. split -spoon sampler (SS) the last 12 inches of the total 18 -inch penetration with a 140 -pound hammer falling 30 inches is considered the "Standard Penetration" or "N- value ". WATER LEVEL MEASUREMENT SYMBOLS: • WL: Water Level WS: While Sampling N /E: Not Encountered WCI: Wet Cave in WD: While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB: After Boring ACR: After Casing Removal Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels may not be possible with only short -term observations. DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non - plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse- grained soils are defined on the basis of their in -place relative density and fine- grained soils on the basis of their consistency. CONSISTENCY OF FINE - GRAINED SOILS RELATIVE DENSITY OF COARSE - GRAINED SOILS Standard Unconfined Penetration or Standard Penetration Compressive N -value (SS) or N -value (SS) Strength, Qu, psf Blows /Ft. Consistency Blows /Ft. Relative Density < 500 0 - 1 Very Soft 0 — 3 Very Loose 500 — 1,000 2 - 4 Soft 4 — 9 Loose 1,000 — 2,000 4 - 8 Medium Stiff 10 — 29 Medium Dense 2,000 — 4,000 8 - 15 Stiff 30 — 49 Dense 4,000 — 8,000 15 - 30 Very Stiff > 50 Very Dense 8,000+ > 30 Hard RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY • Descriptive Term(s) of other Percent of Major Component constituents Dry Weight of Sample Particle Size Trace < 15 Boulders Over 12 in. (300mm) With 15 — 29 Cobbles 12 in. to 3 in. (300mm to 75 mm) Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75 mm) Sand #4 to #200 sieve (4.75mm to 0.075mm) RELATIVE PROPORTIONS OF FINES Silt or Clay Passing #200 Sieve (0.075mm) Descriptive Term(s) of other Percent of PLASTICITY DESCRIPTION constituents Dry Weight Term Plasticity Index Trace < 5 Non - plastic 0 With 5 —12 Low 1 -10 Modifiers > 12 Medium 11 -30 High > 30 1[erracon_ .. , y UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests" Soil Classification Group Symbol Group Name' Coarse Grained Soils Gravels Clean Gravels Cu z 4 and 1 5 Cc 5 3 GW Well- graded gravel` More than 50% retained More than 50% of coarse Less than 5 %fines° Cu < 4 and /or 1 > Cc > 3 GP Poorly graded gravel' fraction retained on on No. 200 sieve No. 4 sieve Gravels with Fines More Fines classify as ML or MH GM Silty graver 0 " than 12 %fines° Fines classify as CL or CH GC Clayey gravel 0H Sands Clean Sands Cu z 6 and 1 <- Cc <_ 3 SW Well- graded sand' 50% or more of coarse Less than 5% fines° Cu < 6 and /or 1 > Cc > 3 SP Poorly graded sand' fraction passes No. 4 sieve Sands with Fines Fines classify as ML or MH SM Silty sand "' More than 12% fines Fines Classify as CL or CH SC Clayey sands "' Fine - Grained Soils Silts and Clays inorganic PI > 7 and plots on or above "A" line' CL Lean clay M 50% or more passes the Liquid limit less than 50 PI < 4 or plots below "A" line' ML SIIt No. 200 sieve organic Liquid limit - oven dried " < 0.75 OL Organic clay` M" Liquid limit - not dried Organic silt Silts and Clays inorganic PI plots on or above "A" line CH Fat clay - ' M Liquid limit 50 or more K L,M PI plots below "A" line MH Elastic Silt organic Liquid limit - oven dried <0.75 OH Organic clay<LMM' Liquid limit - not dried Organic siltK.L.M Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat " Based on the material passing the 3 -in. (75 -mm) sieve "If fines are organic, add "with organic fines" to group name. E If field sample contained cobbles or boulders, or both, add "with cobbles ' If soil contains ? 15% gravel, add "with gravel" to group name. or boulders, or both" to group name. ' If Atterberg limits plot in shaded area, soil is a CL -ML, silty clay. C Gravels with 5 to 12% fines require dual symbols: GW -GM well - graded K If soil contains 15 to 29% plus No. 200, add "with sand" or "with gravel with silt, GW -GC well - graded gravel with clay, GP -GM poorly gravel," whichever is predominant. graded gravel with silt, GP -GC poorly graded gravel with clay. L If soil contains >_ 30% plus No. 200 predominantly sand, add ° Sands with 5 to 12% fines require dual symbols: SW -SM well - graded "sandy" to group name. sand with silt, SW -SC well - graded sand with clay, SP -SM poorly graded nn o sand with silt, SP -SC poorly graded sand with clay If soil contains ? 30 /° plus No. 200, predominantly gravel, add "gravelly" to group name. E CU = 060/D10 Cc = (D30) "PI >_ 4 and plots on or above "A" line. D10 x D60 ° PI < 4 or plots below "A" line. F If soil contains >_ 15% sand, add with sand" to group name. P PI plots on or above "A" line. ° If fines classify as CL -ML, use dual symbol GC -GM, or SC -SM. ° PI plots below "A" line. 60 r - i i i — 1 -' For classification of fine - grained soils and fine - grained fraction , _ of co arse - grained soils __'____^ J am? /_ ` `c e 50 V - -- Equation of "A" - line o-• ,'' I .•P d Horizontal at PI =4 to LL =25.5. 1 I I \X 110.-i X 40 !— then PI =0.73 (LL -20) • 0 ~ Ca ILI Equation of "U" -line ` Vertical at LL =16 to P1=7. , Z 30 f then PI =0.9 (LL -8) -' I_ — G - ` -_ I � , F I- I I I ,' .,°- ; Q 20 i- - - - -:- __ G - - -__ ; - - - 1 a ' MH or OH � _ ... — . _- - - - -� _ 7 I I ML or OL I ' 0 10 16 20 . 30 40 50 60 70 80 90 100 110 LIQUID LIMIT (LL) lrerracon _ Form 111 -6/98