Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Report
�1 s--/O S&) &itt/d4If Go-1 GEODESIGN& REPORT OF GEOTECHNICAL ENGINEERING SERVICES Proposed SW Greenburg Road Development 9550 SW Greenburg Road Tigard, Oregon For Evergreen Builders, LLC October 20, 201 5 GeoDesign Project: EvergreenB-3-01 / r {l/ I [IDESIGNZ NNN October 20, 2015 Evergreen Builders, LLC 22331 SW Lebeau Road Sherwood, OR 97140 Attention: Mr. Daryl Retzlaff Report of Geotechnical Engineering Services Proposed SW Greenburg Road Development 9550 SW Greenburg Road Tigard, Oregon GeoDesign Project: EvergreenB-3-01 GeoDesign is pleased to present our report of geotechnical engineering services for the proposed residential development located at 9550 SW Greenburg Road in Tigard, Oregon. This report has been prepared in accordance with our proposal dated September 2, 201 5. We appreciate the opportunity to be of continued service to you. Please contact us if you have questions regarding this report. Sincerely, GeoDesign, Inc. '7" 4-17 Brett A. Shipton, P.E., G.E. Principal Engineer TCM:BAS:kt Attachments One copy submitted(via email only) Document ID: EvergreenB-3-01-10201 5-geor.docx ©2015 GeoDesign, Inc. All rights reserved. 15575 SW Sequoia Pkwy, Suite 100 I Portland,OR 97224 1503.968.8787 www.geodesigninc.com TABLE OF CONTENTS PAGE NO. 1.0 INTRODUCTION 1 2.0 PROJECT UNDERSTANDING 1 3.0 PURPOSE AND SCOPE 1 4.0 SITE CONDITIONS 2 4.1 Surface Conditions 2 4.2 Subsurface Conditions 2 5.0 CONCLUSIONS 3 6.0 SITE DEVELOPMENT RECOMMENDATIONS 3 6.1 Site Preparation 3 6.2 Construction Considerations 4 6.3 Temporary Slopes 5 6.4 Erosion Control 5 6.5 Structural Fill 5 7.0 FOUNDATION SUPPORT RECOMMENDATIONS 7 7.1 Spread Footings 7 8.0 SLABS-ON-GRADE 8 9.0 PERMANENT RETAINING STRUCTURES 8 10.0 DRAINAGE CONSIDERATIONS 9 11.0 SEISMIC DESIGN CRITERIA 9 12.0 PAVEMENT RECOMMENDATIONS 9 12.1 Pavement Design 9 12.2 Conventional Pavement Material Requirements 10 1 3.0 OBSERVATION OF CONSTRUCTION 10 14.0 LIMITATIONS 10 FIGURES Vicinity Map Figure 1 Site Plan Figure 2 Surcharge-Induced Lateral Earth Pressures Figure 3 APPENDIX Field Explorations A-1 Laboratory Testing A-1 Exploration Key Table A-1 Soil Classification System Table A-2 Boring Logs Figures A-1 -A-6 Test Pit Logs Figures A-7 -A-9 Summary of Laboratory Data Figure A-10 ACRONYMS G EODESIG NZ EvergreenB-3-01:10201 5 1.0 INTRODUCTION GeoDesign, Inc. is pleased to present this geotechnical engineering report for proposed residential development located at 9550 SW Greenburg Road in Tigard, Oregon. The location of the site relative to surrounding physical features is shown on Figure 1. Acronyms used herein are defined at the end of this document. 2.0 PROJECT UNDERSTANDING We understand that the proposed development consists of six three-story apartment buildings. The development will also include underground utilities and associated paved parking areas, drive aisles, and landscaped areas. Structural loads were not available at the time of this report; however, we have assumed that column loads will be less than 300 kips and floor loads will be less than 150 psf. We have assumed that cuts and fills will be minimal and less than approximately 5 feet each. 3.0 PURPOSE AND SCOPE The purpose of our work was to explore the site subsurface conditions and provide geotechnical engineering recommendations for use in design and construction of the proposed development. The specific scope of our services is summarized as follows: • Coordinated and managed the field investigation, including public utility locates, access preparation, and scheduling of subcontractors and GeoDesign field staff. • Drilled six borings to depths of up to 23.5 feet BGS. The borings were drilled using solid- stem augers and were completed within the footprint of each building. • Excavated six test pits to a depth of 10.0 feet BGS. The test pits were excavated in the parking area and roadways. • Maintained continuous logs of the explorations, collected samples at representative intervals, and observed groundwater conditions. • Performed a laboratory testing program. The specific laboratory tests performed on selected soil samples were as follows: • Moisture content determinations in general accordance with ASTM D 2216 • Particle-size analysis in general accordance with ASTM D 1 140 • Provided recommendations for site preparation and grading, including temporary and permanent slopes, fill placement criteria, suitability of on-site soil for fill, subgrade preparation, and recommendations for wet weather construction. • Provided recommendations for excavation and excavation support. • Provided shallow foundation recommendations for the support of the proposed structures, including allowable bearing capacity, estimated settlement, and lateral resistance. • Provided recommendations for use in the design of conventional retaining walls, including backfill and drainage requirements and lateral earth pressures. • Provided recommendations for construction of asphalt pavements for on-site access roads and parking areas, including subbase, base course, and asphalt paving thickness. • Evaluated groundwater conditions at the site. Provided general recommendations for dewatering during construction and subsurface drainage. G EODESIGNN 1 EvergreenB-3-01:102015 • Provided seismic design coefficients as prescribed by the 2012 IBC and 2014 SOSSC. • Prepared this geotechnical engineering report presenting our findings, conclusions, and recommendations. 4.0 SITE CONDITIONS 4.1 SURFACE CONDITIONS The site is located on the east side of SW Greenburg Road near the intersection of SW Washington Square Road. The site was generally vegetated with high grass and weeds at the time of our exploration. The northwestern and southern borders are vegetated with medium to large trees. The western portion of the site is relatively level and the eastern portion slopes gently downward from the center of the site toward the eastern property line. Land use in the vicinity of the site is primarily residential and commercial use. 4.2 SUBSURFACE CONDITIONS We explored subsurface conditions at the site by drilling six borings (B-1 through B-6) to depths of up to 23.5 feet BGS and excavating six test pits (TP-1 through TP-6) to a depth of 10.0 feet BGS. The approximate locations of our explorations are shown on Figure 2. Descriptions of the field explorations and laboratory testing and logs of the explorations are presented in the Appendix. The following sections provide a brief description of the subsurface conditions encountered in the explorations. 4.2.1 Root and Tilled Zone In general, a root zone and tilled zone were observed at the surface of the site in most of the test pit explorations. The root zone extends to depths of approximately 5 to 8 inches BGS, and the tilled zone generally extends to depths of approximately 14 to 18 inches BGS. 4.2.2 Fill Fill was encountered in test pits TP-2 and TP-3 located near the central portion of the site. The fill extends to a depth of approximately 2 feet BGS and consists of medium stiff to stiff silt with sand and trace debris (brick, rubble, glass, and metal debris). Fill was not encountered in any of the other explorations at the site. 4.2.3 Silt and Sand Native soft to hard silt was encountered to depths of 16.3 to 21.5 feet BGS in borings. The silt contains varying amounts of silt and gravel and the consistency generally increases with depth. The silt is underlain by dense to very dense sand with silt and gravel to the total depths explored of 20.6 to 21.5 feet BGS, or refusal in all borings. Cobbles were inferred in borings at the refusal depths. G EODESIGNz 2 EvergreenB-3-01:10201 5 4.2.4 Groundwater Groundwater seepage was not observed in any of the test pit explorations. Groundwater was inferred at depths of 17 to 20 feet BGS in several borings. Based on our experience in the site vicinity, perched groundwater should be expected at shallower depths, particularly during and after extended periods of wet weather. The depth to groundwater is expected to fluctuate in response to seasonal changes, changes in surface topography, and other factors not observed in the site vicinity. Caving was not observed in the test pits completed for our subsurface exploration. 5.0 CONCLUSIONS In our opinion, the site is suitable for the proposed development. We anticipate that the following geotechnical factors will have an impact on the design and construction of the proposed improvements. The proposed buildings can be supported on spread footings that bear on undisturbed native soil or structural fill overlying undisturbed native soil. An approximately 14-to 18-inch-thick tilled zone was encountered in most explorations. The tilled zone material should either be removed or scarified and compacted within all structural areas. The near-surface soil is primarily fine grained. This fine-grained soil is easily disturbed during wet weather or when at a moisture content that is above optimum. If not carefully executed, site preparation, grading, utility trench work, and roadway excavation in this soil can create extensive soft areas. Significant subgrade repair costs can result. Cobbles and boulders were inferred in borings completed for this study at depths of approximately 20 to 23.5 feet BGS. When encountered, cobbles and especially boulders, if encountered during excavation, will result in difficult excavation conditions and may require special equipment and procedures for removal. Our specific recommendations for site development are presented in the following sections of this report. 6.0 SITE DEVELOPMENT RECOMMENDATIONS 6.1 SITE PREPARATION 6.1.1 Grubbing and Stripping The existing root zone should be stripped and removed from the site in all proposed building and pavement areas. Based on our explorations, the depth of stripping will be approximately 5 to 8 inches. Greater stripping depths may be required to remove localized zones of loose or organic soil. The actual stripping depth should be based on field observations at the time of construction. Stripped material should be transported off site for disposal or used in landscaped areas. G EODESIGN= 3 EvergreenB-3-01:10201 5 6.1.2 Subgrade Preparation and Evaluation An approximately 14- to 18-inch-thick tilled zone was observed in most of the explorations. We recommend removing or scarifying the stripped ground surface to the depth of the tilled zone within all building and paved fill areas prior to placing structural fill. The scarified soil should be compacted as recommended for structural fill. The on-site silty material is sensitive to small changes in moisture content and will be difficult, if not impossible, to compact adequately during wet weather. Scarification and compaction of the subgrade will likely only be possible during extended dry periods and following moisture conditioning of the soil. Following stripping and prior to placing fill, pavement, or building improvements, the exposed subgrade should be evaluated by proof rolling. The subgrade should be proof rolled with a fully loaded dump truck or similar heavy, rubber-tire construction equipment to identify soft, loose, or unsuitable areas. A member of our geotechnical staff should observe the proof rolling to evaluate yielding of the ground surface. Soft or loose zones identified during proof rolling should be excavated and replaced with compacted structural fill. Areas that appear too wet or soft to support proof rolling equipment should be prepared in accordance with recommendations for wet weather construction provided in the "Construction Considerations"section of this report. 6.1.3 Test Pit Locations The test pit excavations were backfilled using the relatively minimal compactive effort of the excavator bucket. Soft spots can be expected at these locations. We recommend that this relatively uncompacted soil be removed from the test pits to a depth of 3 feet below finished subgrade. If a test pit is located within 10 feet of a footing, we recommend full-depth removal of the uncompacted soil. The resulting excavation should be brought back to grade with structural fill. 6.2 CONSTRUCTION CONSIDERATIONS Fine-grained soil present on this site is easily disturbed during the wet season. If not carefully executed, site preparation, utility trench work, and roadway excavation can create extensive soft areas and significant repair costs can result. Earthwork planning should include considerations for minimizing subgrade disturbance. If construction occurs during the wet season, or if the moisture content of the surficial soil is more than a few percentage points above the optimum, site stripping and cutting may need to be accomplished using track-mounted equipment, loading removed material into trucks supported on granular haul roads. The thickness of the granular material for haul roads and staging areas will depend on the amount and type of construction traffic and should be the responsibility of the contractor. Generally, a 12- to 18-inch-thick mat of granular material is sufficient for light staging areas and the basic building pad but is generally not expected to be adequate to support heavy equipment or truck traffic. The granular mat for haul roads and areas with repeated heavy construction traffic typically needs to be increased to between 18 to 24 inches. The actual thickness of haul roads and staging areas should be based on the contractor's approach to site development and the amount and type of construction traffic. The material used to construct haul roads and staging area should also be selected by the contractor. G EODESIGW! 4 EvergreenB-3-01:102015 6.3 TEMPORARY SLOPES Construction less than 10 feet high should be no steeper than 1%H:l V. If slopes greater than 10 feet high are required, GeoDesign should be contacted to make additional recommendations. All cut slopes should be protected from erosion by covering them during wet weather. If sloughing or instability is observed, the slope should be flattened or the cut supported by shoring. 6.4 EROSION CONTROL The on-site soil is moderately susceptible to erosion. Consequently, we recommend that slopes be covered with an appropriate erosion control product if construction occurs during periods of wet weather. We recommend that all slope surfaces be planted as soon as practical to minimize erosion. Surface water runoff should be collected and directed away from slopes to prevent water from running down the slope face. Erosion control measures such as straw bales, sediment fences, and temporary detention and settling basins should be used in accordance with local and state ordinances. 6.5 STRUCTURAL FILL Structural fill includes fill beneath foundations, slabs, pavements, any other areas intended to support structures, or within the influence zones of structures. Structural fill should be free of organic matter and other deleterious material and, in general, should consist of particles no larger than 3 inches in diameter. Recommendations for suitable fill material are provided in the following sections. 6.5.1 On-Site Native Soil The on-site native soil will be suitable for use as structural fill only if it can be moisture conditioned. The on-site silty soil is sensitive to small changes in moisture content and may be difficult, if not impossible, to compact adequately during wet weather or when its moisture content is more than a few percentage points above optimum. Laboratory tests indicate that the moisture content of the native silt unit is significantly greater than the anticipated optimum moisture content required for satisfactory compaction. Therefore, this soil may require extensive drying if it is used as structural fill. We recommend using imported granular material for structural fill if the moisture content of the on-site soil cannot be reduced. Native soil should be placed in lifts with a maximum uncompacted thickness of 8 inches and compacted to not less than 92 percent of the maximum dry density, as determined by ASTM D 1557. 6.5.2 Imported Granular Material Imported granular material should be pit- or quarry-run rock, crushed rock, or crushed gravel and sand that is fairly well graded between coarse and fine and has less than 5 percent by dry weight passing the U.S. Standard No. 200 Sieve. All granular material must be durable such that there is no degradation of the material during and after installation as structural fill. The percentage of fines can be increased to 12 percent if the fill is placed during dry weather and provided the fill material is moisture conditioned, as necessary, for proper compaction. The material should be placed in lifts with a maximum uncompacted thickness of 12 inches and compacted to not less than 95 percent of the maximum dry density, as determined by G EODESIGN= 5 EvergreenB-3-01:102015 ASTM D 1557. During the wet season or when wet subgrade conditions exist, the initial lift should have a maximum thickness of 15 inches and should be compacted with a smooth-drum roller without the use of vibratory action. 6.5.3 Floor Slab Base Rock Imported durable granular material placed beneath building floor slabs should be clean crushed rock or crushed gravel and sand that is fairly well graded between coarse and fine. The granular material should have a maximum particle size of 1Y2 inches, have less than 5 percent by dry weight passing the U.S. Standard No. 200 Sieve, and have at least two mechanically fractured surfaces. The imported base rock should be placed in one lift and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557. 6.5.4 Recycled Concrete Recycled concrete can be used for structural fill provided the concrete is processed to a relatively well-graded material with maximum particle size of 3 inches. This material can be used as trench backfill and general structural fill if it meets the requirements for imported granular material, which would require a smaller maximum particle size. The material should be placed in lifts with a maximum uncompacted thickness of 12 inches and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1 557. 6.5.5 Trench Backfill Trench backfill for the utility pipe base and pipe zone should consist of durable well-graded granular material containing no organic or other deleterious material, have a maximum particle size of% inch, and have less than 8 percent by dry weight passing the U.S. Standard No. 200 Sieve. Backfill for the pipe base and to the springline of the pipe should be placed in maximum 12-inch- thick lifts and compacted to not less than 90 percent of the maximum dry density, as determined by ASTM D 1557, or as recommended by the pipe manufacturer. Backfill above the springline of the pipe should be placed in maximum 12-inch-thick lifts and compacted to not less than 92 percent of the maximum dry density, as determined by ASTM D 1557. Trench backfill located within 2 feet of finish subgrade elevation should be placed in maximum 12-inch-thick lifts and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557. 6.5.6 Stabilization Material If groundwater is present at the base of utility excavations, we recommend placing trench stabilization material at the base of the excavation consisting of at least 2 feet of well-graded gravel, crushed gravel, or crushed rock with a minimum particle size of 4 inches and less than 5 percent by dry weight passing the U.S. Standard No. 4 Sieve. The material should be free of organic matter and other deleterious material and should be placed in one lift and compacted until "well keyed." 6.5.7 Soil Amendment with Cement As an alternative to the use of imported granular material for wet weather structural fill, an experienced contractor may be able to amend the on-site silt soil with portland cement or with G EODESIGNf 6 EvergreenB-3-01:102015 limekiln dust and portland cement to obtain suitable support properties. Successful use of soil amendment depends on the use of correct mixing techniques, soil moisture content, and amendment quantities. Soil amending should be conducted in accordance with the specifications provided in OSSC 00344 (Treated Subgrade). Removal of oversized material may be required in some areas to prevent damage to the tilling equipment required for cement amendment. Amendment of the existing gravel surfacing material is not recommended. Specific recommendations for soil amending can be provided based on exposed site conditions, if necessary. However, for preliminary design purposes, we recommend a target strength for cement-amended soils of 80 psi. The amount of cement used to achieve this target generally varies with moisture content and soil type. It is difficult to predict field performance of soil to cement amendment due to variability in soil response, and we recommend laboratory testing to confirm expectations. Generally, 4 percent cement by weight of dry soil can be used when the soil moisture content does not exceed approximately 20 percent. If the soil moisture content is in the range of 25 to 35 percent, 5 to 7 percent by weight of dry soil is recommended. The amount of cement added to the soil may need to be adjusted based on field observations and performance. Moreover, depending on the time of year and moisture content levels during amendment, water may need to be applied during tilling to appropriately condition the soil moisture content. Portland cement-amended soil is hard and has low permeability; therefore, this soil does not drain well, nor is it suitable for planting. Future planted areas should not be cement amended, if practical, or accommodations should be planned for drainage and planting. 7.0 FOUNDATION SUPPORT RECOMMENDATIONS The planned structures may be supported by continuous wall and isolated column footings founded on the underlying undisturbed soil or on structural fill overlying firm native soil. Our recommendations for use in foundation design and construction are provided in the following sections. 7.1 SPREAD FOOTINGS 7.1.1 Bearing Capacity The proposed structures can be supported on conventional spread footings bearing on firm, undisturbed native soil or on structural fill underlain by firm, undisturbed native soil. Undocumented fill, if encountered, should be removed from footing subgrades and backfilled with structural fill. The structural fill should extend a minimum of 6 inches beyond the footing perimeter for every foot excavated below the base grade of the footings. Due to the potential undocumented fill at the site, we recommend that we be retained to observe the footing subgrades and replacement of undocumented fill with structural fill. We recommend that footings be sized based on an allowable bearing pressure of 3,000 psf. This is a net bearing pressure; the weight of the footing and overlying backfill can be ignored in calculating footing sizes. The recommended allowable bearing pressure applies to the total of dead plus long-term live loads. We recommend an allowable bearing capacity of 5,000 psf for short-term loads such as those resulting from wind or seismic forces. Continuous wall and G EODESIGN= 7 EvergreenB-3-01:102015 spread footings should be at least 18 and 24 inches wide, respectively. The bottom of exterior footings should be at least 18 inches below the lowest adjacent final grade. The bottom of interior footings should be placed at least 12 inches below the base of the floor slab. Total post-construction settlement is expected to be less than 1 inch. Differential settlement is expected to be less thanY2 inch. 7.1.2 Lateral Resistance Lateral loads on footings can be resisted by passive earth pressure on the sides of the footings and by friction on the base of the footings. The available passive earth pressure for footings confined by native soil and structural fill is 350 pcf. Adjacent floor slabs, pavements, or the upper 12-inch depth of adjacent unpaved areas should not be considered when calculating passive resistance. A coefficient of friction equal to 0.35 may be used when calculating resistance to sliding on the native soil. A coefficient of friction equal to 0.45 may be used for footings founded on granular structural fill. 8.0 SLABS-ON-GRADE A minimum 6-inch-thick layer of base rock should be placed and compacted over the prepared subgrade to assist as a capillary break. The base rock should be crushed rock or crushed gravel and sand meeting the requirements outlined in the "Structural Fill" section of this report. The imported granular material should be placed in one lift and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557. A subgrade modulus of 120 pci can be used to design the floor slab. Floor slab base rock should be replaced if it becomes contaminated with excessive fines (greater than 5 percent by dry weight passing the U.S. Standard No. 200 Sieve). Vapor barriers are often required by flooring manufacturers to protect flooring and flooring adhesives. Many flooring manufacturers will warrant their product only if a vapor barrier is installed according to their recommendations. Selection and design of an appropriate vapor barrier(if needed) should be based on discussions among members of the design team. We can provide additional information to assist you with your decision. 9.0 PERMANENT RETAINING STRUCTURES Permanent retaining structures free to rotate slightly around the base should be designed for active earth pressures using an equivalent fluid unit pressure of 35 pcf. If retaining walls are restrained against rotation during backfilling, they should be designed for an at-rest earth pressure of 55 pcf. This value is based on the assumption that(1) the retained soil is level, (2) the backfill is drained, and (3) the wall is less than 12 feet in height. Lateral pressures induced by surcharge loads can be computed using the methods presented on Figure 3. Seismic lateral forces can be calculated using a dynamic force equal to 7H2 pounds per linear foot of wall, where G EODESIGNU. 8 EvergreenB-3-01:1 0201 5 H is the wall height. The seismic force should be applied as a distributed load with the centroid located at 0.6H from the wall base. Footings for retaining walls should be designed in as recommended for shallow foundations. Drains consisting of a perforated drainpipe wrapped in a geotextile filter should be installed behind retaining walls. The pipe should be embedded in a zone of coarse sand or gravel containing less than 2 percent by dry weight passing the U.S. Standard No. 200 Sieve and should outlet to a suitable discharge. 10.0 DRAINAGE CONSIDERATIONS We recommend that all roof drains be connected to a tightline leading to storm drain facilities. Pavement surfaces and open space areas should be sloped such that surface water runoff is collected and routed to suitable discharge points. We also recommend that ground surfaces adjacent to buildings be sloped away from the buildings to facilitate drainage away from the buildings. 11.0 SEISMIC DESIGN CRITERIA Seismic design is prescribed by the 2014 SOSSC and the 201 2 IBC. Table 1 presents the site design parameters prescribed by the 2012 IBC for the site. Table 1. Seismic Design Parameters Short Period 1 Second Period Parameter (TL=0.2 second) (T = 1.0 second) MCE Spectral Acceleration, S Ss= 0.98 g S = 0.43 g Site Class D Site Coefficient, F Fa= 1.11 F = 1.58 Adjusted Spectral Acceleration, SM SMS= 1.09 g SM = 0.67 g Design Spectral Response SDS= 0.73 g Sp = 0.45 g Acceleration Parameters, SD Liquefaction settlement is the result of seismically induced densification and subsequent ground settlement of loose sand and silty sand below the groundwater table. Based on the findings of our subsurface exploration, it is our opinion that liquefaction is not considered a site hazard. 12.0 PAVEMENT RECOMMENDATIONS 12.1 PAVEMENT DESIGN Our pavement recommendations are based on a minimum California Bearing Ratio value of 3 and a design life of 20 years. We do not have specific information on the frequency and type of G EODESIGN=. 9 EvergreenB-3-01:102015 vehicles that will use the area; however, we have assumed that post-construction traffic conditions will consist of no more than five heavy trucks per day. We recommend a pavement section consisting of a minimum of 3.0 inches of AC pavement underlain by a minimum of 10.0 inches of aggregate base. For areas subjected to passenger car traffic only, we recommend a pavement section consisting of a minimum of 2.5 inches of AC pavement underlain by a minimum of 8.0 inches of aggregate base. All thicknesses are intended to be the minimum acceptable. The design of the recommended pavement section is based on the assumption that construction will be completed during an extended period of dry weather. Wet weather construction could require an increased thickness of aggregate base. We can provide additional recommendations in a separate memorandum if pavement design is required for public roadways. 12.2 CONVENTIONAL PAVEMENT MATERIAL REQUIREMENTS The AC should be Level 3, %z-inch, dense ACP as described in OSSC 00744 (Asphalt Concrete Pavement) and be compacted to 91 percent of the specific gravity of the mix, as determined by ASTM D 2041. Minimum lift thickness for%z-inch, dense ACP is 2.0 inches. Asphalt binder should be performance graded and conform to PG 70-22. The crushed base rock should consist of 3/- or 1Y2-inch-minus material meeting the requirements in OSSC 00641 (Aggregate Subbase, Base, and Shoulders), with the exception that the crushed base rock should have less than 5 percent by dry weight passing the U.S. Standard No. 200 Sieve. The crushed base rock should be compacted in one lift to at least 95 percent of the maximum dry density, as determined by ASTM D 1 557. 13.0 OBSERVATION OF CONSTRUCTION Satisfactory earthwork and foundation performance depends to a large degree on the quality of construction. Subsurface conditions observed during construction should be compared with those encountered during the subsurface explorations. Recognition of changed conditions often requires experience; therefore, qualified personnel should visit the site with sufficient frequency to detect whether subsurface conditions change significantly from those anticipated. In addition, sufficient observation of the contractor's activities is a key part of determining that the work is completed in accordance with the construction drawings and specifications. 14.0 LIMITATIONS We have prepared this report for use by Evergreen Builders and members of their design and construction teams for the proposed project. The data and report can be used for estimating purposes, but our report, conclusions, and interpretations should not be construed as a warranty of the subsurface conditions and are not applicable to other sites. Soil explorations indicate soil conditions only at specific locations and only to the depths penetrated. The soil explorations do not necessarily reflect soil strata or water level variations that may exist between exploration locations. If subsurface conditions differing from those described are noted during the course of excavation and construction, re-evaluation will be G EODESIGNV 10 EvergreenB-3-01.102015 necessary. In addition, if design changes are made, we should be retained to review our conclusions and recommendations and to provide a written evaluation or modification. The scope of our services does not include services related to construction safety precautions, and our recommendations are not intended to direct the contractor's methods, techniques, sequences or procedures, except as specifically described in our report for consideration in design. Within the limitations of scope, schedule, and budget, our services have been executed in accordance with the generally accepted practices in this area at the time this report was prepared. No warranty or other conditions, express or implied, should be understood. ♦ ♦ ♦ We appreciate the opportunity to be of continued service to you. Please call if you have questions concerning this report or if we can provide additional services. Sincerely, GeoDesign, Inc. ol:4 Tacia C. Miller, P.E., G.E. r9.-7;;;;;4.-A-4'5,Senior Associate Engineer EG• 41,0" <9 4-'1/4 cNQ' 20 0 rT A. Se Brett A. Shipton, P.E., G.E. EXPIRES: 6!30!16 Principal Engineer G EODESIGN= 11 EvergreenB-3-01:102015 Printed By:aday I Print Date:12/23/2015 8:47:08 AM File Name:J:\E-L\EvergreenB\EvergreenB-3\EvergreenB-3-01\Figures\CAD\EvergreenB-3-01-det-srchrg-indcd-lat.dwg I Layout:FIGURE 3 Fes-- X=mH X=mH POINT LOAD,Qp LINE LOAD,Q L r-1 a STRIP LOAD,q —t— A ' '\ i Z=nH Z=nH �� i i_ _% H IW H r H W 1111 ah ah ah \��\\ FOR m<0.4= \\\ FOR m<0.4= �\\j� ah=2�c (3-SIN/3 COS 2a) \\\/\ a _ 0.28 r? \j\\j\ Cr —QL 0.2 n \/j\\//\ 3.14 /\/\/\/\\�\ h H2 (0.16+r? `rg//i//i//\/\\�� h H (0.16+rt ? •/,;\„/;\//%/%/%\\\//j (19 IN RADIANS) FOR m>0.4= FOR m>0.4= a _21.77m2r? a CIL 1.28m2n h H2 (m2+n2)3 h _ H (m2+n2}' LINE LOAD PARALLEL TO WALL STRIP LOAD PARALLEL TO WALL IIIIIP X=mH ah =oh COS2(1.10) NOTES: i a1 1 1. THESE GUIDELINES APPLY TO RIGID WALLS WITH POISSON'S RATIO ASSUMED TO BE 0.5 FOR BACKFILL MATERIALS. DISTRIBUTION OF HORIZONTAL PRESSURES 2. LATERAL PRESSURES FROM ANY COMBINATION OF ABOVE LOADS MAY BE DETERMINED BY THE PRINCIPLE OF VERTICAL POINT LOAD SUPERPOSITION. 3. VALUES IN THIS FIGURE ARE UNFACTORED. G EODESIGN? EVERGREENB-3-01 SURCHARGE-INDUCED LATERAL EARTH PRESSURES 1 5575 SW Sequoia Parkway-Suite 100 PROPOSED SW GREENBURG ROAD DEVELOPMENT Portland OR 97224 OCTOBER 201 5 FIGURE 3 Off 503.968.8787 Fax 503.968.3068 TIGARD, OR X 0 z w a a Q APPENDIX FIELD EXPLORATIONS GENERAL We explored subsurface conditions at the site by drilling six borings (B-1 through B-6) to depths of up to 23.5 feet BGS and excavating six test pits (TP-1 through TP-6) to a depth of 10.0 feet BGS. The approximate locations of our explorations are shown on Figure 2. Drilling and excavation services were provided by Dan J. Fischer Excavating, Inc. of Forest Grove, Oregon. The borings were drilled using a trailer-mounted drill rig equipped using solid-stem auger drilling techniques on October 12, 201 5. The test pits were excavated using a track-mounted excavator on September 24, 2015. A member of our geology staff observed the explorations. Exploration logs are presented in this appendix. The locations of the explorations were determined in the field by pacing from site features. This information should be considered accurate to the degree implied by the methods used. SOIL SAMPLING We obtained representative samples of the various soil encountered in the explorations for geotechnical laboratory testing. Samples were obtained from the borings using a 1%2-inch-inside diameter, split-spoon sampler(by conducting SPTs). The split-spoon sampling was conducted in general accordance with ASTM D 1 586. The %2-inch-inside diameter, split-spoon samplers were driven into the soil with 140-pound hammer free falling 30 inches. The hammer was lifted using a rope and cathead with two wraps around the head. The samplers were driven a total distance of 18 inches. The number of blows required to drive the sampler the final 12 inches is recorded on the boring logs, unless otherwise noted. Grab samples of the soil observed in the test pit explorations were obtained from the walls and/or base of the test pits. SOIL CLASSIFICATION The soil samples were classified in accordance with the "Exploration Key" (Table A-1) and "Soil Classification System" (Table A-2), which are presented in this appendix. The logs indicate the depths at which the soils or their characteristics change, although the change could be gradual. If the change occurred between sample locations, the depth was interpreted. Classifications and sampling intervals are shown on the exploration logs presented in this appendix. LABORATORY TESTING CLASSIFICATION The soil samples were classified in the laboratory to confirm field classifications. The laboratory classifications are presented on the exploration logs if those classifications differed from the field classifications. MOISTURE CONTENT We tested the natural moisture content of selected soil samples in general accordance with ASTM D 2216. The natural moisture content is a ratio of the weight of the water to the dry weight of soil in a test sample and is expressed as a percentage. The test results are presented in this appendix. G EODESIGN= A-1 EvergreenB-3-01:102015 • PARTICLE-SIZE ANALYSIS Particle-size analyses were performed on selected samples in general accordance with ASTM D 1140. This test determines of the amount of material finer than a 75-pm (No. 200) sieve expressed as a percentage of the dry weight of soil. The test results are presented in this appendix. G ODESIGN= A-2 EvergreenB-3-01:102015 SYMBOL SAMPLING DESCRIPTION Ill Location of sample obtained in general accordance with ASTM D 1586 Standard Penetration Test with recovery Location of sample obtained using thin-wall Shelby tube or Geoprobe® sampler in general accordance with ASTM D 1 587 with recovery 1 Location of sample obtained using Dames & Moore sampler and 300-pound hammer or pushed with recovery Location of sample obtained using Dames& Moore and 140-pound hammer or pushed with recovery Location of sample obtained using 3-inch-O.D. California split-spoon sampler and 140-pound hammer NLocation of grab sample Graphic Log of Soil and Rock Types ,;‘•!1,,,.1. ;,; Observed contact between soil or Rock coring interval i,:;"? rock units(at depth indicated) Water level during drilling Inferred contact between soil or rock units(at approximate depths indicated) Y Water level taken on date shown . • . —- GEOTECHNICAL TESTING EXPLANATIONS ATT Atterberg Limits PP Pocket Penetrometer CBR California Bearing Ratio P200 Percent Passing U.S. Standard No. 200 CON Consolidation Sieve DD Dry Density RES Resilient Modulus DS Direct Shear SIEV Sieve Gradation HYD Hydrometer Gradation TOR Torvane MC Moisture Content UC Unconfined Compressive Strength MD Moisture-Density Relationship VS Vane Shear OC Organic Content kPa Kilopascal P Pushed Sample ENVIRONMENTAL TESTING EXPLANATIONS CA Sample Submitted for Chemical Analysis ND Not Detected P Pushed Sample NS No Visible Sheen PID Photoionization Detector Headspace SS Slight Sheen Analysis MS Moderate Sheen ppm Parts per Million HS Heavy Sheen G EO DESIGN' kway EXPLORATION KEY TABLE A-1 15575 SW Sequoia Parkway-Suite 100 Portland OR 97224 Off 503.968 8787 Fax 503.968.3068 RELATIVE DENSITY- COARSE-GRAINED SOILS Relative Density Standard Penetration Dames& Moore Sampler Dames& Moore Sampler Resistance (140-pound hammer) (300-pound hammer) Very Loose 0- 4 0- 11 0-4 Loose 4- 10 1 1 - 26 4- 10 Medium Dense 10- 30 26- 74 10- 30 Dense 30- 50 74- 120 30-47 Very Dense More than 50 More than 120 More than 47 CONSISTENCY- FINE-GRAINED SOILS Consistency Standard Penetration Dames& Moore Sampler Dames& Moore Sampler Unconfined Compressive Resistance (140-pound hammer) (300-pound hammer) Strength (tsf) Very Soft Less than 2 Less than 3 Less than 2 Less than 0.25 Soft 2 -4 3 -6 2 - 5 0.25 - 0.50 Medium Stiff 4- 8 6- 12 5 -9 0.50 - 1.0 Stiff 8- 15 12 - 25 9- 19 1.0- 2.0 Very Stiff 15 - 30 25 - 65 19- 31 2.0-4.0 Hard More than 30 More than 65 More than 31 More than 4.0 PRIMARY SOIL DIVISIONS GROUP SYMBOL GROUP NAME CLEAN GRAVELS GW or GP GRAVEL GRAVEL (< 5%fines) of GRAVEL WITH FINES GW-GM or GP-GM GRAVEL with silt (more50% cothanre f5 (� 5%and _< 12%fines) GW-GC or GP-GC GRAVEL with clay COARSE-GRAINED retained on GRAVELS WITH FINES GM silty GRAVEL SOILS No. 4 sieve) (> 12%fines) GC clayey GRAVEL GC-GM silty, clayey GRAVEL (more than 50% CLEAN SANDS retained onSAND (<5%o fines) SW or SP SAND No. 200 sieve) (50%or more of SANDS WITH FINES SW-SM or SP-SM SAND with silt coarse mor (? 5%and _< 12%fines) SW-SC or SP-SC SAND with clay passing SM silty SAND SANDS WITH FINES No. 4 sieve) SC clayey SAND (> 12%fines) SC-SM silty, clayey SAND ML SILT FINE-GRAINED CL CLAY SOILS Liquid limit less than 50 CL ML silty CLAY (50%or more SILT AND CLAY OL ORGANIC SILT or ORGANIC CLAY passing MH SILT No. 200 sieve) Liquid limit 50 or CH CLAY greater -— OH ORGANIC SILT or ORGANIC CLAY HIGHLY ORGANIC SOILS PT PEAT MOISTURE ADDITIONAL CONSTITUENTS CLASSIFICATION _ Secondary granular components or other materials Term Field Test such as organics, man-made debris,etc. Silt and Clay In: Sand and Gravel In: very low moisture, Percent Fine-Grained Coarse- Percent Fine-Grained Coarse- dry dry to touch Soils Grained Soils Soils Grained Soils damp,without < 5 trace trace < 5 trace trace moist visible moisture 5 12 minor with 5 15 minor minor visible free water, > 12 some silty/clayey 15 - 30 with with wet usuallysaturated > 30 sandy/gravelly y/gravelly Indicate GEODESIGN= 5575 SW Sequoia Parkway Suite,00 SOIL CLASSIFICATION SYSTEM TABLE A-2 Portland OR 97224 Off 503 968.8787 Fax 503.968.3068 Z o = u w ♦BLOW COUNT INSTALLATION AND IF- z —' COMMENTS DEPTH = MATERIAL DESCRIPTION >w — ••MOISTURE CONTENT RQD%FEET w 0LU N ] Q �'CORE REC% cc— 0 50 100 0.0 Very stiff, brown with orange mottled - SILT with sand (ML),trace organics (plant roots); moist, sand is fine to ' medium (7-inch-thick root zone). 2.5— Y6 5.0— stiff at 5.0 feet ir] 1 7.5— brown, without organics at 7.5 feet 1 • • to.o— medium stiff at 10.0 feet i 12.5— ts.o— medium stiff to stiff, brown with orange = mottles, minor gravel at 1 5.0 feet A9. • 17.5— 20.0— © 5013" --- _.-- 20.3 Exploration terminated at a depth of Possible cobbles at 20.0feet. 20.3 feet due to refusal. Surface elevation was not measured at the time of Hammer efficiency factor is unknown. exploration. 22.5 SPT completed using two wraps with a cathead. Latitude: 45.45087 Longitude: -122.77429 (determined from hand-held CPS) 0 25.0- 2 _ z O U 27.5 U _ 30.0 0 0 50 100 DRILLED BY:Dan J.Fischer Excavating,Inc. LOGGED BY:TJS COMPLETED:10/12/15 u BORING METHOD:solid-stem auger(see document text) BORING BIT DIAMETER:4 1/4 inches LLi G EODESIG N z ? EVERGREENS 3 O1 BORING B-1 z 15575 SW Sequoia Parkway-Suite 100 m PortlandOR97224 OCTOBER 201 5 PROPOSED SW GREENBURG ROAD DEVELOPMENT FIGURE A-1 Off 503.968.8787 Fax 503.968.3068 TIGARD,OR z 0 0= u w A BLOW COUNT INSTALLATION AND DEPTH u Q a Z a •MOISTURE CONTENT% COMMENTS FEET a MATERIAL DESCRIPTION w o F- g w < Hil RQD% V7)CORE REC% cc w H —0.0 L7 0 50 100 Very stiff, light brown with orange mottled SILT with sand (ML),trace organics (plant roots); moist, sand is fine to medium (7-inch-thick root zone). 2.5— 18 s.o— stiff, brown at 5.0 feet (� :11 • 7'5 medium stiff to stiff,without organics $ • at 7.5 feet �' A 10.0— medium stiff at 10.0 feet - 1 • 12.5— p = -o - m 1 s.o— soft to medium stiff; sand is fine to 4 coarse at 15.0 feet I A - v Possible cobbles at 20.0 20.0— • J0/1.y feet. Exploration terminated at a depth of 201 Sampler was possibly p bouncing off cobbles.at 20.1 feet due to refusal. 20.0 feet. Possible water level at 20.0 feet. Hammer efficiency factor is unknown. 22.5— SPT completed using two wraps with a Surface elevation was not measured at the time of p -- cathead. exploration. Latitude: 45.45084 Longitude: -122.77390 (determined from hand-held GPS) 0 25.0— z o - 0 LL, v 27.5 u _ ki c 30.0 0 50 100 DS „, DRILLED BY:Dan J.Fischer Excavating,Inc. LOGGED BY:TJS COMPLETED:10/12/15 V BORING METHOD:solid-stem auger(see document text) BORING BIT DIAMETER:4 1l4 inches z GEODESIGN? EVERGREENB-3-01 BORING B-2 o 5575 SW Sequoia Parkway-Suite 100 PROPOSED SW GREENBURG ROAD DEVELOPMENT Portland OR 97224 OCTOBER 2015 FIGURE A-2 Off 503.968.8787 Fax 503.968.3068 TIGARD,OR v Z = u w BLOW COUNTHZ INSTALLATION AND DEPTH u <CL — - •MOISTURE CONTENT% COMMENTS FEET d MATERIAL DESCRIPTION >w H g o /_ < P l T] RQD% CORE REC% cc wo so 100 —0.0 ASPHALT CONCRETE(3.0 inches). -O° /- 0.3 AGGREGATE BASE (5.0 inches). ` 0.7 Stiff, brown SILT with sand (ML), trace - organics (plant roots); moist, sand is 2.5— fine to medium (7-inch-thick root zone). io s.o— medium stiff tostiff at 5.0 feet � B A 7.5 stiff,without organics at 7.5 feet 11 A • 10.0— medium stiff at 10.0 feet 6 A 12.5— 1s.o— I soft to medium stiff to stiff at 1 5.0 feet IL A 17.5— E zo.o— hard, red-brown with black mottles, minor gravel; sand is fine to coarse • it 20.0 feet Exploration terminated at a depth of 21.5 Surface elevation was not measured at the time of LL' 21.5 feet due to refusal exploration. Hammer efficiency factor is unknown. SPT completed using two wraps with a cathead. 0 25.0— Latitude: 45.45052 Z Longitude: -122.77396 (determined from hand-held GPS) 2 u 27.5- 2 H _ m 30.0 0 50 100 DRILLED BY:Dan J.Fischer Excavating,Inc. LOGGED BY:TJS COMPLETED:10/12/15 U cece BORING METHOD:solid-stem auger(see document text) BORING BIT DIAMETER:4 1/4 inches GEODESIGN= EVERGREENB-3-01 BORING B-3 m 15575 SW Sequoia Parkway-Suite 100 Portland OR 97224 OCTOBER 2015 PROPOSED SW GREENBURG ROAD DEVELOPMENT Off 503.968.8787 Fax 503.968.3068 TIGARD,OR FIGURE A-3 Z Si = u w BLOW COUNT INSTALLATION AND ~~ Z J •MOISTURE CONTENT% COMMENTS DEPTH = MATERIAL DESCRIPTION >w FEET d w- w Q [1 I l RQD% 7/ CORE REC% iz w I— V V0 SO 100 -0.0-7-- Stiff, brown with light brown and orange mottled SILT with sand (ML), trace organics (plant roots); moist, sand is fine to medium (6-inch-thick root 2.5— zone). s.o— medium stiff, brown with light brown 7 mottles at 5.0 feet A 7.5 ' : brown at 7.5 feet r 5: 10.0— I: C 12.5 is.o— li soft to medium stiff; sand is fine to coarse at 15.0 feet r I 17.5— 20.0Heav chatter at 1 9.5 feet. i- ' Dense, brown with orange and black 20.0 41 Possible water level at 20.0 mottled SAND with silt and gravel (SP- A feet. SM); moist, fine to medium. �Ex Exploration terminated at a depth of 21.5 surface elevation was not p p measured at the time of LLI 22,5— 21.5 feet due to refusal. exploration. a O Z Hammer efficiency factor is unknown. - SPT completed using two wraps with a cathead. 0 25.0— Latitude: 45.45066 Z - Longitude: -122.77351 N - (determined from hand-held CPS) w 0 0 w U E7 27.5— — u LO Z.: it O 30.0 O 0 SO 100 m ,z„ DRILLED BY:Dan J.Fischer Excavating,Inc. LOGGED BY:TJS COMPLETED:10/12/15 ce u w BORING METHOD:solid-stem auger(see document text) BORING BIT DIAMETER:4 1/4 inches w GEODESIGN? EVERGREENB-3-01 BORING B-4 z 15575 SW Sequoia Parkway-Suite 100 m Portland OR 97224 OCTOBER 201 5 PROPOSED SW GREENBURG ROAD DEVELOPMENT FIGURE A-4 Off 503.968.8787 Fax 503.968.3068 TIGARD,OR Z 0 -N z J A BLOW COUNT INSTALLATION AND DEPTH = MATERIAL DESCRIPTION j w — °- ••MOISTURE CONTENT% COMMENTS FEET o w < ITS I1 RQD% V/I CORE REC% cc w H o 50 100 Stiff, brown with light brown and orange mottled SILT with sand (ML); moist, sand is fine to medium (6-inch- thick root zone). 2.5— s.o— brown with light brown mottles at 5.0 feet , 7.5 , medium stiff to stiff, brown with black - mottles at 7.5 feet j • • 10.0— -_— — medium stiff at 10.0 feet 6 ♦ 12.5— — 15.0— stiff; sand is fine to coarse at 15.0 feet 12 A Very dense, gray and brown SAND with 16.3 silt and gravel (SP-SM); moist, fine to 17.5— coarse. with black mottles at 19.5 feet 20.0 P200 I. 7-2240/1"A P200=30% • Exploration terminated at a depth of 20.6 Surface elevation was not t 20.6 feet due to refusal. e ploration.the time of F 22,5— Hammer efficiency factor is unknown. SPT completed using two wraps with a cathead. - Latitude: 45.45039 Longitude: -122.77349 0 25.0— (determined from hand-held GPS) o 0 u27.5— c m 30.0 0 50 loo DRILLED BY:Dan J.Fischer Excavating,Inc. LOGGED BY:TJS COMPLETED:10/12/15 BORING METHOD:solid-stem auger(see document text) BORING BIT DIAMETER:4 1/4 inches GEODESIGN? EVERGREENB-3-01 BORING B-5 m 15575 SW Sequoia Parkway-Suite too PROPOSED SW GREENBURG ROAD DEVELOPMENT Portland OR 97224 OCTOBER 2015 FIGURE A-5 Off 503.968.8787 Fax 503.968.3068 TIGARD,OR Z o = V w ♦ BLOW COUNT INSTALLATION AND DEPTH u Q~ Z •MOISTURE CONTENT% COMMENTS = MATERIAL DESCRIPTION >w FEET a w w Q I RQD% V!CORE REC% Lu H N V o 50 100 Stiff, brown with light brown and orange mottled SILT with sand (ML), • trace organics; moist, sand is fine to medium (6-inch-thick root zone). 2.5— - 11 - I s.o medium stiff to stiff, brown,without organics at 5.0 feet M �o 7'5 medium stiff at 7.5 feet 6 10.0— soft to medium stiff at 10.0 feet 4 12.5- - 15.0— ♦ 17.5— Possible water level at 18.0 _ medium stiff to stiff, gray at 18.5 feet feet. 20.0— very dense, brown and orange with black mottles at 19.5 feet 32 Dense, brown and gray SAND with silt 20.5A - and gravel (SP-SM); moist, fine to - coarse. 22.5— - very dense at 23.0 50/6"feet [; • Exploration terminated at a depth of 23.5 Surface elevation was not measured at the time of 23.5 feet due to refusal. exploration. 15 25.0- 1 - Hammer efficiency factor is unknown. SPT completed using two wraps with a cathead. 2 Latitude: 45.45030 27.5— Longitude: -122.77297 (determined from hand-held GPS) - I 0 30.0 0 50 100 „Z, DRILLED BY:Dan J.Fischer Excavating,Inc. LOGGED BY:TJS COMPLETED:10/12/15 L.7 w BORING METHOD:solid-stem auger(see document text) BORING BIT DIAMETER:4 1/4 inches LJ GEODESIGN? EVERGREENB-3-01 BORING B-6 z 15575 SW Sequoia Parkway-Suite 100 Portland OR 97224 PROPOSED SW GREENBURG ROAD DEVELOPMENT Off 503.968.8787 Fax 503.968.3068 OCTOBER 201 5 TIGARD,OR FIGURE A-6 Z _o u w ' 7 Z --i •MOISTURE DEPTHFEETa MATERIAL DESCRIPTION cc w o I- Q 1' CONTENT COMMENTS vlV TP-1 0.0 i- 0 50 100 Medium stiff to stiff, brown SILT with _ ' sand (ML),trace organics; moist, sand is N1 • — fine to medium (18-inch-thick tilled 1.5 — 1 zone, 8-inch-thick root zone). 2.5Stiff tovery I e stiff, brown SILT with sand = Y _ PP � PP >4.5 tsf (ML); moist, sand is fine to medium. _ ; brown with light brown and orange , 5.0— 1 mottles at 4.0 feet brown with light brown mottles at 6.5 7.s— feet brown at 9.0 feet 10.0 1 Exploration completed at a depth of 10.0 M No groundwater seepage observed 1 0.0 feet. at the time of exploration. No caving observed at the time of Latitude: 45.45081 exploration. 1 12.5— Longitude: -122.77436 Surface elevation was not (determined from hand-held GPS) measured at the time of exploration. TP-2 0 So° ° 0 50 100 0.01 Medium stiff to stiff, brown SILT with sand (ML), trace organics and debris (brick rubble, glass,and metal); moist Z 1 - -, (18-inch-thick tilled zone, 7-inch-thick - 2.5 I root zone) - FILL. 2 0 I - 11 Stiff to very stiff, brown SILT with sand (ML), trace organics; moist. PP N, PP=>4.5 tsf brown with light brown and orange 9 o• 5.0— mottles at 4.0 feet H Z a H u 7.5— 1 brown at 7.0 feet z u 0 u F 10.0 - u - Exploration completed ata depth of 10.0 No groundwater seepage observed `° - 1 0.0 feet. at the time of exploration. No caving observed at the time of - Latitude: 45.45067 exploration. 12.5 Longitude: -122.77436 Surface elevation was not (determined from hand-held GPS) measured at the time of w -- exploration. C U CC w 0 50 100 d EXCAVATED BY:Dan J.Fischer Excavating,Inc. LOGGED BY:TJS COMPLETED:09/24/15 ce d EXCAVATION METHOD:backhoe(see document text) EVERGREENB 3 01 TEST PIT GEODESIGNv o 15575 SW Sequoia Parkway-Suite 100 F Portland OR 97224 OCTOBER 2015 PROPOSED SW GREENBURG ROAD DEVELOPMENT FIGURE A-7 Off 503.968.8787 Fax 503.968.3068 TIGARD,OR