Loading...
Report (50) GEODESIGN, INC. . 2F GEOTECHNICAL, ENVIRONMENTAL, AND GEOLOGICAL CONSULTANTS m 1 • • cr: _ >s REPORT OF GEOTECHNICAL ENGINEERING SERVICES P 74 AVENUE INDUSTRIAL PARK SITE TIGARD, OREGON FOR PACIFIC REALTY VENTURES, INC. 17400 S.W. Upper Boones Ferry Rd., Suite 230 • Portland, OR 97224. • (503) 968 -8787 • Fax (503) 968 -3063 6• GEO INC. GEOTECHNICAL, ENVIRONMENTAL, AND GEOLOGICAL CONSULTANTS • April 30, 1998 ? Pacific Realty Ventures, Inc. 17700 SW Upper Boones Ferry Road, Suite 100 Portland, Oregon 97224 Attention: Mr. Dick Ossey Report of Geotechnical Engineering Services 74 Avenue Industrial Park Site Tigard, Oregon GDI Project: PacificRealty -2 GeoDesign is pleased to submit four copies of our "Report of Geotechnical Engineering Services" for the proposed 74 Avenue Industrial Park site. The site is located approximately 500 feet north of the intersection between SW Durham Road and SW 74 Avenue in Tigard, Oregon. Our services for this project were conducted in accordance with our proposal dated March 3, 1998. We appreciate the opportunity to be of continued service to you. you have Please call if y questions regarding this report. f,t Sincerely, GeoDesign, Inc. George Saunders, P.E. Principal cc: Mr. Fred VanDomelen VLMK Consulting Engineers GPS:SVM:kb Attachments Document ID: PacificRealty -2 -geor Four Copies Submitted RECEIVE APR 30 1998 VLMK CONSULUING ENGINtERS 17400 S.W. Upper Boones Ferry Rd., Suite 230 • Portland, OR 97224. • (503) 968 -8787 • Fax (503) 968 -3068 4,: k9 1 ".3 CONTENTS Page No. INTRODUCTION 1 PURPOSE AND SCOPE 1 ;, BACKGROUND 2 ,. SITE CONDITIONS 3 Surface Conditions 3 Subsurface Conditions 3 I CONCLUSIONS AND RECOMMENDATIONS 4 General 4 Erosion Control 4 Site Preparation 5 Construction Considerations 5 Groundwater Considerations 6 Structural Fill 6 Permanent Slopes 8 Shallow Foundations g s Deep Foundations 10 Floor Slabs 11 Retaining Structures 11 Resistance to Sliding 12 -,a Pavement Recommendations 12 Site Drainage 13 Li Seismic Considerations 13 Observation of Construction 14 .. LIMITATIONS 14 L' ,.. FIGURES Figure No. I Vicinity Map 1 Site Plan 2 Drilled Pier Capacities 3 APPENDIX A Page No. Carlson Testing, Inc. Test Pit Logs A -1 .I APPENDIX B i Field Explorations and Laboratory Testing C -1... C -2 } Soil Classification System Logs of Borings _2 a i GeoDesign, Inc. i PacificRealty- 2:043098 Report of Geotechnical Engineering Services 74 Avenue Industrial Park Site Tigard, Oregon For Pacific Realty Ventures, Inc. "-4 INTRODUCTION This report presents the results of GeoDesign's geotechnical engineering evaluation of the proposed site for the 74th Avenue Industrial Park. The site is located approximately 500 feet north of the intersection between SW Durham Road and SW 74 Avenue in Tigard, A Oregon. The site location relative to surrounding physical features is shown in Figure 1. Mr. Dan Maloney of Pacific Realty Ventures, Inc. provided us with a copy of the preliminary site plans prepared by VLMK Consulting Engineers. Mr. Maloney also provided us a copy of a July 10, 1997 preliminary geotechnical engineering report prepared by Carlson Testing, Inc. (CTI). The project will include two single -story structures, Buildings A and B as shown in Figure 2. Building A has a floor plate of approximately 9,570 square feet and . Building B has a floor plate of approximately 33,500 square feet. Building A will be located Tr approximately 5 feet from the top of the slope heading down to Fanno Creek. Portions of • Building B will be located up to 20 feet from Fanno Creek slope and pavements west of Building B will be located within 5 feet of the Fanno Creek slope. Construction is currently scheduled to start in July 1998. Based on our discussions with Mr. Fred VanDomelen of VLMK Consulting Engineers, the column loading will be dead loads of approximately 40 kips and total combined Toads (dead plus live loads) of approximately 90 kips. The continuous wall footing will have a dead load of approximately 1.5 kips per lineal foot and a total combined load (dead plus live loads) of I approximately 2.0 kips per lineal foot. The floor slab loading will likely be less than 100 pounds per square foot (psf). However, we have been asked to evaluate the possibility of . floor slab loads up to 250 psf. A grading plan was not available at the time of this report. However, the site plan indicates a finished floor grade of 140 feet mean sea level (MSL) for Building A and 141 feet MSL for Building B. Based on this information and the existing site grades, cuts and fills between 1 and 2 feet will be required to achieve final grade. PURPOSE AND SCOPE The purpose of our geotechnical engineering services is to explore subsurface conditions and provide geotechnical engineering recommendations for foundation support and site development. Our scope of work included: a Drill five 26.5- to 42.0- foot -deep exploratory borings using a drill rig equipped for mud rotary drilling. = GeoDesign, Inc. 1 PacificRealty- 2:043098 S'.11 . -; • Obtain soil samples for laboratory testing and maintain a log of encountered soil, rock and groundwater conditions in each exploration. • Complete the following laboratory tests on selected soils samples. • Moisture content and density tests in general accordance with American Society for Testing and Materials (ASTM) D 2216 and ASTM D 2937. • One consolidation test in general accordance with ASTM D 2435. • Provide recommendations for site preparation, grading and drainage, stripping depths, fill type for imported materials, compaction criteria, cut and fill slope criteria, procedures for use of on -site soils and wet weather earthwork procedures. • Provide recommendations for design and construction of shallow spread foundations, including allowable design bearing pressure and minimum footing depth and width. • Provide recommendations for preparation of floor slab subgrade. • Recommend design criteria for retaining walls, including lateral earth pressures, backfill, compaction and drainage. • Provide recommendations for construction of asphalt pavements for on -site access roads and parking areas, including subbase, base course, and asphalt paving thickness. • Provide recommendations for subsurface drainage of foundations, floor slabs and pavements. • Evaluate liquefaction potential of site soils, including estimates of liquefaction- induced settlement. If necessary, provide a discussion of methods to improve the liquefaction resistance of site soils. • Provide a discussion of seismic activity near the site and recommendations for the Z r'. factor and site coefficient. • Provide a report summarizing our explorations, laboratory testing and recommendations. BACKGROUND A Based on Figure 1 of CTI's July 10, 1997 report, the former grades at the site vary between approximately 130 and 140 feet above MSL. Based on our discussions with Mr. Maloney, we understand that the site was fill to the present grades which vary between approximately 139 to 143 feet MSL. Based on information provided in CTI's report, the majority of the fill was placed in 1988 to 1989 under a City of Tigard permit. However, we understand that documentation on the procedures used to place and compact the fill is not available. • Logs provided in CTI's report indicate that the fill is over 11 feet thick at some locations. CTI characterizes the fill as highly variable, ranging from soft to hard silt and including variable amounts of concrete and asphalt fragments, gravel- to boulder -size rock, and layers with a relatively high organic content. Relative to the information provided in CTI's Figure 1, the • approximate locations of CTI's test pits are provided in Figure 2. A copy of CTI's test pit logs and Figure 1 is included in Appendix A. _ .1 GeoDesign, Inc. 2 PacificRealty- 2:043098 " 3 ..8 I `` SITE CONDITIONS SURFACE CONDITIONS The site is bounded by Fanno Creek on the west, industrial developments on the north and ;L south and SW 74` Avenue on the east. The subject site currently is undeveloped. Site vegetation consists of ankle -high grass with a few scattered trees along the western portion of the site. Several piles of fill material exist at the site and soft saturated ground exists 7. over the majority of the site. In general, the site gradually slopes toward Fanno Creek to 1 the west. The slopes down from the site to Fanno Creek are relatively steep, varying between approximately 1 H:1 V (horizontal:vertical) to 1 V. >i Fragments of concrete were observed at the ground surface over scatter areas of the site. The northern 30 to 50 feet of the site contains crushed gravel consisting of 3- inch -minus I material. SUBSURFACE CONDITIONS - We explored subsurface conditions by completing five borings (B -1 through B -5) to depths of 26.5 to 42.0 feet. The approximate locations of the explorations are shown in Figure 2. Select soil samples from the explorations were tested to determine the natural moisture t content, in -situ dry density (dry unit weight) and consolidation properties. The subsurface exploration and laboratory testing programs are described in Appendix B. The boring logs and results of the laboratory testing are also presented in Appendix B. °- An approximately 4- to 6- inch -thick root zone exists at the ground surface. The subsurface profile consists of variable fill underlain by native silt, sand, and gravel. As shown in Figure 2, the fill extends to depths of 3 to 13 feet. The shallower depths of fill were observed in the a northeast portion of the site. The thickness of the fill is greatest along the western boundary of the site and adjacent to the slopes down to Fanno Creek. In general, the fill consists of very soft to medium stiff silt with variable amounts of sand and occasional layers with some organics. Based on the information provided in CTI's test pit logs TP -2 and TP -7, the fill also . includes occasional cobbles and boulders. Laboratory testing of selected samples resulted in a moisture content varying between 22 and 53 percent. However, one sample with a relative high organic content resulted in a moisture content of 104 percent. The dry density of a 12- foot deep sample at B-4 was 100 pounds per cubic foot (pcf). To the depths explored, the native material below the fill consists of layered silt, sand and gravel. The silt generally varies between stiff to very stiff, the sand varies between medium .: • dense to dense, and the gravel varies between medium dense to very dense. Laboratory testing of selected samples of the native materials indicated moisture contents varying - between 18 and 40 percent. However, one sample with a relative high organic content - resulted in a moisture content of 71 percent. The dry density varied between 92 and 102 pcf; however, one sample with a relative high organic content resulted in a dry density of 71 pcf. Consolidation testing on a sample obtained at depth of 17 feet from B -5 indicated a moderate degree of over - consolidation. The compressibility is relatively low in the over - consolidated range of bads and relatively high above this range of loads. .P • .t, GeoDesign, Inc. 3 PacificRealty- 2:043098 F- ;. ` Because of the mud rotary drilling methods used, groundwater seepage was not observed in • the borings. However, groundwater seepage was reported in three of CTI's Togs (TP -1, TP -3 and TP -7) at depths between 4 and 7.5 feet below the ground surface. Groundwater seepage was not observed /reported in the remaining CTI logs. CONCLUSIONS AND RECOMMENDATIONS GENERAL The subsurface conditions at the site include between . 3 and 13 feet of variable A'° undocumented fill. This conclusion is based on the subsurface conditions encountered in our explorations (B -1 through B -5) and in CTI's test pit explorations (TP -1 through TP -7), as reported in their July 10, 1997 preliminary geotechnical engineering report. The subsurface material underlying the fill consists of layered and relatively firm silt, sand and gravel. Based on our review of available information and the results of our explorations; laboratory testing and analysis, it is our opinion that the majority of the proposed structures with foundation Toads as previously discussed can be supported on shallow foundations. Variable embedment and granular pads will be required to reduce the risk of excessive differential 7 settlement. Our shallow foundation recommendations are provided in the "Shallow Foundations" section of this report. Because of the small setback between Building A and Fanno Creek and the thick deposits of fill in this area, it is our opinion that the western edge of Building A should be supported on drilled piers or on deeply- embedded footings. Our recommendations for drilled piers are provided in the "Deep Foundations" section of this report. Our recommendations for embedding footings are provided in the "Permanent Slopes" and "Shallow Foundations" sections of this report. The silt soils at the site can be sensitive to small changes in moisture content and difficult, if not impossible, to adequately compact during wet weather. If construction is planned for the wet season, the project budget should reflect the recommendations for wet weather contained in this report. A more detailed discussion is presented in the "Construction Considerations" and "Structural Fill' sections of this report. The following paragraphs present specific geotechnical recommendations for design and construction of the proposed development. i EROSION CONTROL The soil at this site is eroded easily by wind and water. Therefore, erosion control measures should be planned carefully and be in place before construction begins. Erosion control plans are required on construction projects located within Washington County and the City of • Tigard. Measures that can be employed to reduce erosion include the use of silt fences, hay bales, buffer zones of natural growth, sedimentation ponds, and granular haul roads. In general, erosion control measures must limit sediment transport to less than 1 ton per acre • per year, as calculated by the Universal Soil Loss equation. GeoDesign, Inc. 4 PacificRealty- 2:043098 : a SITE PREPARATION • Trees should be removed from all building and paved areas. In addition, root balls should be grubbed out to the depth of the roots, which could exceed 2.5 feet below the ground surface. Depending on the methods used to remove the root balls, considerable disturbance and loosening of the subgrade could occur during site grubbing. We recommend that soil disturbed during grubbing operations be removed to expose firm undisturbed subgrade. The resulting excavations should be backfilled with structural fill. If grubbing activities disturb Tess than a 12 -inch depth of soil and provided the earthwork is r$ being completed in the drier summer period, the material can be scarified, moisture conditioned, and compacted in place. The existing root zone should be stripped and removed from the site in all proposed building and pavement areas and for a 5 -foot margin around such areas. Based on our explorations, the depth of stripping will be approximately 4 to 6 inches. Stripping depths up to 12 inches deep may be required at isolated and small areas along the western boundary of the site where thicker vegetation exists. Greater stripping depths may be required to remove localized zones of loose or organic soil and 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. 1 Some concrete and asphalt debris exists at the site. We recommend that all concrete and asphalt debris large than 1 foot in diameter be transported off site for disposal. Material smaller than 1 foot in diameter can be mixed in with the general structural fill and campacted as recommended in the "Structural Fill" section of this report. Proofrolling should be conducted after site preparation activities have been completed and after mass grading. The subgrade should be proofrolled 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 proofrolling to evaluate yielding of the ground surface. Soft or loose zones identified during proofrolling should be excavated and replaced with compacted structural fill. Areas that appear too wet or soft to support proofrolling equipment should be prepared in accordance with recommendations for wet weather construction provided in the "Construction Considerations" section of this report. CONSTRUCTION CONSIDERATIONS Trafficability of the site may be difficult during or after extended wet periods or when the moisture content of the surface soil is more than a few percentage points above optimum 1, moisture content. When wet, the silty soils are easily disturbed and may provide • inadequate support for construction equipment. Proofrolling of the subgrade should not be • performed during wet weather or if wet ground conditions exist. Instead, the subgrade should be evaluated by probing. Soils that have been disturbed during site preparation activities, or soft or loose zones identified during probing, should be removed and replaced with compacted structural fill. The use of granular haul roads or staging areas will be necessary for support of construction traffic during the rainy season or when the moisture content of the surface soil is more than a GeoDesign, Inc. 5 PacificRealty- 2:043098 few percentage points above optimum moisture content. A 12 -inch thickness of imported FAR granular material generally should be sufficient for Tight staging areas and the building pad but is generally not expected to be adequate to support heavy equipment or truck traffic. Haul roads and areas with repeated heavy construction traffic should be constructed with a minimum thickness of 18 inches of imported granular material. The imported granular material should consist of crushed rock that has a maximum particle size of 4 inches, is well graded and has less than 5 percent by weight passing the U.S. Standard No. 200 Sieve. We recommend that a geotextile be placed as a barrier between the subgrade and imported granular material in areas of repeated construction traffic. The geotextile should have a minimum Mullen burst strength of 250 psi (pounds per square inch) for puncture resistance and an AOS (apparent opening size) between an U.S. Standard No. 70 and No. 100 Sieve. As an alternative to placing 12 to 18 inches of granular material, the subgrade can be stabilized using cement amendment. If this approach is used, the thickness of granular material in staging areas and along haul roads can be reduced to 6 inches. This recommendation is based on an assumed minimum unconfined compressive strength of 200 pounds per square inch (psi) for subgrade amended to a depth of 12 inches. Cement amendment is addressed below under the "Soil Amendment" section of this report. GROUNDWATER CONSIDERATIONS Groundwater was observed at depths of 4 and 7.5 feet and may raise above these levels • during extended wet weather. We recommend that foundation drains be installed at this site. The foundation drains should be installed at least 2 feet below the finished floor grade, constructed at a minimum slope of about '/2 percent and routed to a suitable discharge (e.g., connected to the storm drain system). The foundation drains should consist of 6- inch - diameter perforated drainpipe embedded in a minimum 3 -foot -wide zone of drain rock. The drain rock should be wrapped in a geotextile filter. The drain rock should be uniformly graded, have a maximum particle size of 3 inches and have less than 2 percent passing the U.S. Standard No. 200 Sieve. The • geotextile should have an AOS between the U.S. Standard No. 70 and 100 Sieve and a water permittivity greater than 1.5 sec'. STRUCTURAL FILL General All material used as structural fill should be free of organic material or other unsuitable materials and particles larger than 3 inches in diameter. On -Site Material The on -site materials consist of silt. Silty soils are generally sensitive to small changes in moisture content and are difficult, if not impossible, to compact adequately during wet weather or when their moisture content is more than a few percentage points above the optimum moisture content. Laboratory testing indicates that the moisture content of the on- site materials are considerably greater than the anticipated optimum moisture content required for satisfactory compaction, which, based on our experience, is approximately 16 • �ti GeoDesign, Inc. 6 PacificRealty- 2:043098 t , } percent. Therefore, moisture conditioning will be required to achieve adequate compaction. ., , We recommend using imported granular material for structural fill if the on -site material cannot be properly moisture - conditioned. As an alternative, use of the on -site silty material as structural fill may be acceptable if it is properly amended with portland cement or.lime. When used as structural fill, the on -site material should be placed in lifts with a maximum uncompacted thickness of 6 to 8 inches and compacted to not less than 92 percent of the ': maximum dry density, as determined by ASTM D 1557. Imported Granular Material Imported granular material for structural fill should be pit or quarry-run rock, crushed rock, or Aui crushed gravel and sand. It should be fairly well - graded between coarse and fine material and have less than 5 percent by weight passing the U.S. Standard No. 200 Sieve. The 9 , 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 1557. During the wet season or when wet subgrade conditions exist, the initial lift should be approximately 18 inches in uncompacted thickness and should be compacted by rolling with a smooth drum roller without use of a drum vibrator. Trench Backfill s Trench backfill for the utility pipe base and pipe zone should consist of well - graded granular material with a maximum particle size of 3 /4 inch and less than 8 percent by weight passing .1 the U.S. Standard No. 200 Sieve. The material should be free of roots, organic matter, and -._, other unsuitable materials. Backfill for the pipe base and pipe zone should be compacted to at least 90 percent of the maximum dry density, as determined by ASTM D 1557, or as E recommended by the pipe manufacturer. Within building and pavement areas, trench backfill placed above the pipe zone should be compacted to at least 92 percent of ASTM D 1557 at depths greater than 2 feet below the finished subgrade and as recommended for structural fill within 2 feet of finished subgrade. In all other areas, trench backfill above the pipe zone should be compacted to at least 90 percent of the maximum dry density, as determined by ASTM D 1557. Soil Amendment r As an alternative to the use of imported granular material, an experienced contractor may be ` able to amend the on -site soils with portland cement to obtain suitable support properties. It is generally less costly to amend on -site soils than to remove and replace soft soils with granular material. Based on the moisture contents, soil types and processing speed, cement amendment would be more suitable at this site than lime amendment. • Cement amendment should not be used if runoff during construction can not be directed away from adjacent wetlands or Fanno Creek. The permeability of cement - amended soil is extremely low. Because of the low permeability, cement amendment should not be ' t completed in landscape areas, or, the cement - amended material should be removed from r landscape areas prior to planting. In addition, there is a risk that rain water can perch within the floor slab base rock over the cement- amended soil during wet weather, resulting in i trapped water under the floor slab. Trapped water can result in slab curling, excessive floor 7 . *< GeoDesign, Inc. 7 PacificRealty- 2:043098 � M1, r:y slab moisture and damage to flooring. We recommend that cement - amended subgrade under building areas be sloped at a minimum of 0.5 percent, with the water collected at the perimeters of the building and routed to a suitable area and discharged away from building. Cement amendment should not be attempted in basement floor slab areas. Successful use of soil amendment depends on use of correct techniques and equipment, soil moisture content, and the amount of cement added to the soil. The recommended .:z percentage of cement is based on soil moisture contents at the time of placing the structural fill. Based on our experience, 3 percent cement by weight of dry soil can generally 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, 4 to 6 percent by weight of dry soil is r:3 recommended. It is difficult to accurately predict field performance due to the variability in soil response to cement amendment. The amount of cement added to the soil may need to be adjusted based on field observations and performance. For preliminary design purposes, we recommend a minimum of 5 percent cement and a treatment depth of 12 inches. It is not possible to amend soils during heavy or continuous rainfall. Work should be completed during suitable conditions. PERMANENT SLOPES General r g Permanent cut and fill slopes should not exceed 2H:1V. Buildings, access roads, and pavements should be located at least 5 feet from the top of cut and fill slopes. The slopes should be planted with appropriate vegetation to provide protection against erosion as soon as possible after grading. Surface water runoff should be collected and directed away from slopes to prevent water from running down the face of the slope. • Fanno Creek Building A will be located approximately 5 feet from the top of a slope down to Fanno Creek. The slopes down to Fanno Creek are relatively steep, varying between approximately 1 H:1 V to 1 V, and contain areas with evidence of prior soil creep and slope movement. Based on topography included in Figure 1 of CTI's report, the slope is approximately 20 feet high. _'; In our opinion, the 5 -foot setback recommended above will not be adequate along Fanno Creek because of the variable fill material observed in the streamside slopes, the steepness of the slopes, and the potential for stream erosion of the top of these slopes. We recommend locating all buildings a minimum of 5 feet from the top of the slope as defined by a 2H:1V • plane that extends upward from the toe of the slope. In addition, pavements and utilities may , be damaged if these elements extend beyond the modified setback recommended above and slope movement occurs. Embedded spread foundations or drilled piers will be required if buildings extend beyond this plane. Under this condition, we recommend that building and retaining wall footings be embedded such that the outer edge of the footing is a minimum horizontal distance of 5 Lbl feet from the 2H :1V plane. Based on our estimates, an embedment of over 10 feet will be y GeoDesign, Inc. 8 PacificRealty- 2:043098 '$i necessary along the west side of Building A to adequately found the footings outside of the recommended setback. In addition, the embedded wall of the footing should be designed 1 a a retaining wall with the free -face defined as the portion of the wall between the ground surface and the intersection of the wall with the above - referenced 2H:1V plane. Our design recommendations for retaining wall are provided in the "Retaining Structures" section of this report. An alternative to embedded footing is the use of drilled piers to support the western -most edge of Building A. Provided the drilled piers are installed at a maximum spacing of 4D, where D is the diameter of the pier, loss of soil from slop instability should not undermine the floor slab because of arching between the piers. However, shoring will need to be installed between piers if slope movement exposes the drilled piers. Our recommendations for drilled piers are provided in the "Deep Foundations" section of this report. r,. SHALLOW FOUNDATIONS Introduction There is a risk of excessive differential settlement because of the variable thickness and consistency of the fill materials at the site. Options to reduce the risk include deep . embedment of foundation element, granular pads and drilled pier foundations. Our recommendations for the buildings A and B are provided in the following paragraphs. . Building A Because of the small setback and steep slopes between Building A and Fanno Creek and the thick deposits of fill in this area, it is our opinion that the western edge of Building A should be supported on drilled piers or on deeply- embedded footings. Our recommendations for drilled piers are provided in the "Deep Foundations" section of this report. Our recommendations for the embedment depth of the footings are provided in the "Cut and Fill Slopes" section of this report. We recommend that footings be sized based on an allowable bearing pressure of 1,500 psf. To further reduce the risk of excessive differential settlement, we recommend that the • ._f footings be underlain by minimum of 2- foot -thick granular pads and that the perimeter of the building be supported on continuous footings. i Building B • With the exception of at B -2, the fill observed in the explorations completed in the area of Building B (B -1 through B -3 and TP-4 through TP -7) consists of relatively firm material. However, an approximately 2- to 3 -foot thick layer of very soft material was observed at a depth of 5 feet at boring B -2. To reduce the risk of excessive differential settlement associated with the variable fill thickness, we recommend that footings be sized based on an allowable bearing pressure of 2,000 psf. To further reduce the risk of excessive differential settlement, we recommend that the footings be underlain by a minimum of 2- foot -thick granular pads and that the perimeter of the building be supported on continuous footings. GeoDesign, Inc. 9 PacificRealty- 2:043098 q 1 1 Granular Pads The granular pads should extend 6 inches beyond the margins of the footings for every foot excavated below the bottom of the footing. The granular pads should consist of crushed rock or crushed gravel and sand that is fairly well - graded between coarse and fine, contain no organic matter or other deleterious materials, have a maximum particle size of 2 inches, and have Tess than 5 percent passing the U.S. Standard No. 200 Sieve. The imported granular material should be compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557, or, as determined by one of our geotechnical staff. We recommend that a member of our geotechnical staff observe the prepared footing subgrade. General 4,4 The bearing pressures described above apply to the total of dead and long -term live loads and may be increased by one -third when considering earthquake or wind loads. These are net bearing pressures; the weight of the footing and overlying backfill can be ignored in calculating footing sizes. Isolated column and continuous wall footings should have minimum widths of 24 inches and 18 inches, respectively. With the exception of the embedment recommendations for the Building A, the base of exterior footings should be founded at least 18 inches below the lowest adjacent finished. grade. Interior footings can be founded 12 inches below the bottom of the floor slab. It is difficult to accurately estimate the settlement at the site because of the variable nature of the fill materials at the site. Based on the subsurface conditions observed, consolidation test results and our settlement analysis, we estimate that total and differential settlements will be • less than 1 and 3 /4 inches, respectively. These estimates are based on the assumption that the floor slab live load is less than 150 psf and less than 2 feet of fill is required to achieve final grade. Total and differential settlements could exceed 3 and 1% inches, respectively if •; the floor slab live loads approach 250 psf. 1 DEEP FOUNDATIONS One alternative discussed above is to support the western wall of Building A on drilled piers. Allowable capacities, both downward and uplift, for 18 -, 24- and 36 -inch diameter drilled piers • are presented in Figure 3. The capacities include a safety factor of 2.5 for end bearing and 2 for skin friction. The embedment depth referenced in Figure 3 is the embedment below a depth of 15 feet. Accordingly, the total pier lengths referenced in Figure 3 vary between 25 and 35 feet. Lateral capacities of the drilled piers will be provided following the selection of . the pier diameter and embedment by the structural engineer. Drilled piers will undergo negligible settlement provided the bottoms of the pier shafts area cleaned adequately. If pier capacities greater than the values shown in the graph are required, the specific application should be reviewed by our office. • • • • : GeoDesign, Inc. 10 PacificRealty- 2:043098 , t FLOOR SLABS • Satisfactory subgrade support for building floor slabs supporting up to 100 psf area loading can be obtained on medium stiff to stiff silts or on structural fill underlain by medium stiff to stiff silts. A 6- inch -thick layer of imported granular material should be placed and compacted • over the prepared subgrade to assist as a capillary break. Imported granular material should be crushed rock or crushed gravel and sand that is fairly well - graded between coarse and fine, contain no deleterious materials, have a maximum particle size of 1% inches, and have less than 5 percent by weight passing the U.S. Standard No. 200 Sieve. 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 150 pci (pounds per cubic inch) may be used to design the floor slab. Settlement of floor slabs supporting the anticipated design Toads and constructed as recommended is not expected to exceed 1 /2 inch. 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. RETAINING STRUCTURES Our retaining wall design recommendations are based on the following assumptions: (1) the walls consist of conventional, cantilevered retaining walls or embedded building walls; (2) the walls are Tess than 15 feet in height; and (3) the backfill is level, drained, and consists of imported granular materials. Reevaluation of our recommendations will be required if the retaining wall design criteria for the project vary from these assumptions. For walls not restrained from rotation, an equivalent fluid pressure of 40 pcf should be used for design. An equivalent fluid pressure of 55 pcf should be used for design of walls restrained from rotation. Superimposed seismic lateral forces should be calculated based on a dynamic force of 9.3H pounds per lineal foot of wall, where H is the height of the wall in feet, and applied at 0.6H from the base of the wall. When computing resistance to lateral loads, a base friction coefficient of 0.35 can be used. Footings for the retaining walls should be designed as recommended for shallow foundations. I As stated above, our recommendations are based on the assumption of drained conditions. Drains that consist of a 8- inch - diameter perforated drainpipe wrapped in a geotextile filter should be installed behind all retaining structures. The pipe should be embedded in a minimum 3- foot -wide zone of drain rock and sloped to drain (minimum slope of 1 /2 percent) toward a suitable discharge. The geotextile should have an AOS between the U.S. Standard No. 70 and 100 Sieve and a water permittivity greater than 1.5 sec The drain rock should be uniformly graded, have a maximum particle size of 3 inches and have less than 2 percent passing the U.S. Standard No. 200 Sieve (washed analysis). • GeoDesign, Inc. 11 PacificRealty- 2:043098 Backfill material placed behind the wall and extending a horizontal distance of 1 /2H, where H is the height of the retaining wall, should consist of the well - graded sand or gravel, with not more than 5 percent by weight passing the U.S. Standard No. 200 Sieve. Alternatively, the on -site soils can be used as backfill material provided a minimum 3- foot -wide column of drain rock wrapped in a geotextile is placed against the wall. The rock column should extend from the foundation drains to within approximately 1 foot of the ground surface. The drain rock should consist of well- graded gravel, with not more than 2 percent by weight passing the U.S. Standard No. 200 Sieve. Backfill should be placed and compacted as recommended for structural fill, with the exception of backfill placed immediately adjacent to walls. Backfill adjacent to walls should be compacted to a lesser standard to reduce the potential for generation of excessive pressure on the walls. Backfill located within a .horizontal distance of 3 feet from the retaining walls should be compacted to approximately 90 percent of the maximum dry density, as determined by ASTM D 1557. Backfill placed within 3 feet of the wall should be compacted in lifts less than 6 inches thick using hand - operated tamping equipment (such as jumping jack or vibratory plate compactors). If flat work (slabs, sidewalk or pavement) will be placed adjacent to the wall, we recommend that the upper 2 feet of fill be compacted to 95 percent of the maximum dry density, as determined by ASTM D 1557. Settlements of up to 1 percent of the wall height commonly occur immediately adjacent to the wall as the wall rotates and develops active lateral earth pressures. Consequently, we recommend that construction of flat work adjacent to retaining walls be postponed at least 4 weeks after construction, unless survey data indicates that settlement is complete prior to that time. RESISTANCE TO SLIDING Lateral loads on footings can be resisted by passive earth pressure on the sides of the structures and by friction on the base of the footings. Our analysis indicates that the available passive earth pressure for footings confined by structural fill or for footings constructed in direct contact with the undisturbed silt soil is 350 pcf. Typically, the movement required to develop the available passive resistance may be relatively large. Therefore, we recommend using a reduced passive pressure of 250 pcf. Adjacent floor slabs, pavements or the upper 12 -inch depth of adjacent unpaved areas should not be considered when calculating passive resistance. t A coefficient of friction equal to 0.35 may be used when calculating resistance to sliding. PAVEMENT RECOMMENDATIONS The pavement subgrade should be prepared in accordance with the previously described site preparation, wet weather construction and structural fill recommendations. Our pavement recommendations assume that traffic at the site will consist of small trucks and passenger cars. We do not have specific information on the frequency of the vehicles that will use the area. However, we have assumed that traffic conditions will consist of no more than 20 two - axle trucks per day. • • Our pavement recommendations are based on a minimum California Bearing Ratio (CBR) value of 3 and a design life of 20 years. In access roadways and areas trafficked by trucks, GeoDesign, Inc. 12 PacificRealty- 2:043098 f~ , j } 2 l 1 '.Y �G - t .1Ss - we recommend a pavement section consisting of a minimum of 3.0 inches of asphalt concrete pavement underlain by a minimum of 9.0 inches of crushed rock base. A pavement section of 2.5 inches of asphalt concrete over 7.0 inches of aggregate base can be used in paved areas that will be exposed to passenger car traffic only. In addition, we 'I recommend that a geotextile separation layer be placed on the subgrade and under the •. crushed rock base in the truck traffic area to prevent migration of the silt up into the base course. The geotextile should meet the requirements previously presented. irI If the subgrade is stabilized with portland cement, a section consisting of 2.5 inches of asphalt concrete over 4 inches of crushed rock base course should be appropriate in passenger car 71 traffic areas and 3.0 inches of inches of AC over 6 inches of crushed rock base course in the ;,:i bus and truck traffic areas. These sections are based on a minimum unconfined compressive strength of 200 psi and a mixing depth of at least 12 inches below the crushed rock 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 I completed during an extended period of dry weather. Wet weather construction could require _ an increased thickness of aggregate base. 3 r< .ii The asphalt concrete pavement should conform to Section 00745 for standard- and heavy - duty asphalt pavements of the Standard Specifications for Highway Construction, Oregon •f State Highway Division, 1991 Edition. The crushed rock base should conform to Section 02630 of these specifications and have less than 5 percent passing the U.S. No. 200 ; sieve. Crushed rock base 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. SITE DRAINAGE .± We recommend that all roof drains be connected to a tightline leading to an appropriate discharge. 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. • SEISMIC CONSIDERATIONS UBC Design Criteria We recommend that the building be designed using the applicable provisions of the State of • Oregon Structural Specialty Code for Zone 3. We recommend using a UBC seismic zone factor, Z, of 0.30 and a site coefficient, S of 1.2. .. Liquefaction Liquefaction settlement is the result of seismically induced densification and subsequent ground settlement of loose /soft soils. Soils such as loose sands below the groundwater table — are particularly susceptible to liquefaction. The very soft silts observed at B -2 and the soft silts observed at B-4 and B -5 may susceptible to liquefaction. However, these soil units are I relatively thin and the amount of liquefaction- induced settlement possible should be less than i • . i �' GeoDesign, Inc. 13 PacificRealty- 2:043098 r • 1 /4 inch. The medium stiff silt fill material and the native silt, sand and gravel material below the fill is not susceptible to liquefaction. Accordingly, we conclude that there is a relatively low risk that liquefaction will cause structural damage to the building. qt OBSERVATION OF CONSTRUCTION Satisfactory foundation and earthwork performance depends to a large degree on quality of construction. Sufficient monitoring of the contractor's activities is a key part of determining that the work is completed in accordance with the construction drawings and specifications. Subsurface conditions observed during construction should be compared with those encountered during the subsurface exploration. Recognition of changed conditions often requires experience; therefore, qualified personnel should visit the site with sufficient frequency to detect if subsurface conditions change significantly from those anticipated. We recommend that GeoDesign be retained to observe earthwork activities, including stripping, proofrolling of the subgrade and repair of soft areas, performing laboratory compaction and field moisture - density tests, observing final proofrolling of the pavement • subgrade and base rock, and asphalt placement and compaction. In addition, if drilled piers are used, we recommend that GeoDesign be retained to observe the installation of all drilled . piers. :a I LIMITATIONS We have prepared this report for use by Pacific Realty Ventures, Inc. and its design and j • construction team for the proposed project. The data and report can be used for bidding or estimating purposes, but our report, conclusions and interpretations should not be construed as warranty of the subsurface conditions and are not applicable to other sites. Exploration observations indicate soil conditions only at specific locations and only to the depths penetrated. They 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, reevaluation will be necessary. The site development plans and design details were preliminary at the time this report was prepared. When the design has been finalized and if there are changes in the site grades or } location, configuration, design loads, or type of construction for the buildings, the conclusions and recommendations presented may not be applicable. If design changes are made, we request that we be retained to review our conclusions and recommendations and to provide a written modification or verification. 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. GeoDesign, Inc. 14 PacificRealty- 2:043098 it Within the limitations of scope, schedule, and budget, our services have been executed in accordance with generally accepted practices in this area at the time the report was prepared. No warranty, express or implied, should be understood. ♦•♦ We appreciate the opportunity pportunity to be of continued service to you. Please call if you have questions concerning this report or if we can provide additional services. -:x Sincerely, GeoDesign, Inc. AQ _ ROF ' 4 17 GIN ., • Aw. Lu: ce,c,„ii..,........:_v ,i George Saunders, P.E. \ \ % a>, ° �, G t� 25 ���° k,� Principal ' ? 5 1 C cre.5 Cal 11 "• T _'1 1 4 ': L a' A GeoDesign, Inc. 15 PacificRealty- 2:043098 • I . I . - • - - .__ , . - • - -- • . 7 ;- -- i ;--• ' rerStar A ' rej .a i .. ,-, Jitmer , c o l ir e gy,.. I.. r -- -.:.: - . 7," ...7,•:. • ....' ..., VT llars.val -.. -- 1 1 I • 1 .i.. 1r/i•-,-' ...--. ..'-... ‘• ) • s 01 IL - . ____ . :,A r, 6 rti. ! . riv e.- .„._,,, Jo: ' ,..., 1 ,... .. ... A • • Al. .....-.• , e . . , 1 / i • ' _____D• L.. c li . 1 • (`••• ''.., . =IN l 1 : : (•••°••• r \ , I • 1\ ' ,' , ' ; • ..). t • ' . .. • • . • .. • ? le . II Ft ;! i .... di, A I c.,, ir. -,.... , ,, •,. :./ ,- ,.,...1_.-• _____- ... /;#1,.__-' • • - ck -.' - • ) 200.. • •Ii- /. . j o , (q) -, . \ al ..... . • \lip/ , ,.,„..... . • - • I ___ "- , i a 6 .0 Jr- . • (x - 1 • ir• o . L II • ' . 11 ' - . 1'2 ' i :e. .) . .: 4 . • C- .. . ,•l ' A - , I c'3 rTrailTrP• ' .' \ ..‘' • a ,;,,, 1 ,,Rwc ' 7-",zil,• . ----- ( . 1 C "; ' \ 1 ')' ° i i i 4lik: ,.' : - TE ,, : , s ( . 1 ‘ - -- ' - '' .. , :, ,, .. • : ......! ,•., 1 .17 . . . __-•--,--•. _-11 1 _s. , 0 ..., "1 T i f li k.___I ji o „= j . • ,,.,.., .ul 1 0 i /1.....,(. : .1 I ' ; ! \z,-,.. :::: r ...- Avg .; , ,== _____... r , • • . , .41 ! • llilli* 4 11,. It._.1 1 ' '• 'I ' ..:_,W l • - • • ' -r- • • L.7'11 - . --- -...tr #.5"; -.;,.. , • :: a rd : • - II 1 %./.` ' . / . . I 1 • . •,,,,, I Y h s, i _,,. ! 1, / - . 0 ' .1193 • iimpoi if A I 4/ R.7 - i g . e •C•••-•,. • 0 : . .,: -- -- „,.,, • 1 6 . I . r .- '1 „ - ----:.,-, , - q. At • • ' i iiii - Lit • ---s s..,/Ati e 9 ,1' - . 61 an , , - _z,..i „-.--,- - - ol ,, ..,, i , - ,- - ._ , r o ,,01 Cook ' I - • : • '. 3 fir" , -,,•-•: .,,,....„,..0.-? -, - - -''e A ''° --• ' - • '-, ( ., ,;\ ..„,,,,,...-- 4 '4 - sir- --1 - - ? - ' - -• • , 0 , r , "--...„, .„- 4 j---_,.,,_ ..,,,,.. , /--- • o p i • " ,-;---] Gr Os %. '--, IL. k • 11 ",\E I A i r - . //,/: t i 4 • -1SZ ..." • :-'1 -, ..w...----„, .. ; _` ,L) _ : ' V.,,...1, r' - do ' _ii.. ... IL :i. '; z.: • - -- - . . --____ ,,- i it ----- 7 . "'sff:_j. - - - -, - i , '' .'-,.----< .. . "),..-.-- ing • , j an i 100 1 ;--F----- , I N\ \'.I■ 1 I 7 - V' , = ;":4 ‘. :. . .,. „. , r , . •ose _ •0 _ _ _, „ , n ..., ,., • c ..:,,a.ei - :1.•• • • , . Pq . • • . ,/,' , . • :I • ■ ' , t .... • R• 7 7 . - / vo I „ \-- '(..-- ,_ - ----- %,./ NE 1 i ii k- .0 '''''' •-•-- • i me . " rx ) . /' ' '' s .. - . 1 * '''''' • ry `'7-",\ 13 `: '''•-•,:: .4. ii IP' • 1-; i• i ,. , i ( . ' 2 . i am - 6?;'• . ■ 9 9' ----/' ,, _ c .,._ c l I: „ .) ; _ ...:-.-:-.,--.-_-_-.,-_ . .k. , .• 0 , 1, ,/ ,;*.t:Lke . o . ._ „ 1-ic. Nide 1 ■,- ..-____, , 97 ;• - /. . • . / Lik 1 Ar) .., ,„,,„ , igme...-_ -- -• .,:•••-•• • I. -- _ 1 1 , s- ` , Ai ,,m_ 1 0. i 0 • .,,• •... •.:-• 1 • •1••••• , Tu, ATIN •'• . • .. •'•• ■I:. • .11 • 1 k it. . ....• . ) P • k -, i 4 grpo R • •10-.1. :if: JAW. Tri - 7 )r.• - ,,,, no 1 1,:j G.041 '54 i l RYoC .(1: ■ .. R' 111- • lir slicir WS 11 - -1 - .....,. , ... _ •;- --__ _._ j ' ..-11 • Al .. ' L • \ • I, ...? ._____) • lagi 4 -:-___ ',Oil ,... ..',-"/ . '''''.`- • . . . -'' ' r •-;- . ' Li „,/, ralierr •-f--... / _ ..,_ "rt...--- •••••■•• • , ....7.@.- .7,-;•_•,- i : ; mimks,/ ) ... . ,-\_, -- .tW,■P =--- ;77 - F - 7t --- ThEliftPt --1.- - 1.--- - 3 .-"- '''. ' .• - 4.-H..- ..--1 ,---; 40,1 ..___- . _,_ ,,, --,...----,, ._____„/„---- ,-, . - - -._•„:-.. ' i z- : .1.• - „,.. . , ...." ------', • .r.:_-7---,,., /..---,...--.,..- 1 - r '. :- :-..--: -..: .. I . .---.--. S - : , ... . -:„..--' ... -- • 1 / °- - .. ____. - - rc ___ ., if .,.-,-..,,- --:- - .. 1 .,, wer: lite I , ‘,.. , 1 . ,,..- __ 1 , : . ... c-- - • I ' 07: o .. T:: -- .,>____ - _- 71. - - -", : - A ' 1 . I , 13 1.612 r t e... I • . 47. ' ... . • uar ,i' .. .. i l a .. „7 ' ---_,...,....._...“ .. I _____:„..- . : I N.::::: . ' '' :"ZIT ••!:Aiirii -.'' . - r '' ..,,L ' ___ 1 - .- r------=.7.---- -1 123 _ 1 - -- - - 1 L 7? - -f - - --- - " - - - J „%7 1:1' -4- \ v --- ' ‘-'-- ' ) _ •TZ qtrINB i. V-- ' ---- I I .7 1 ••••,- -:-'' ......C.) ......"-- .. S. ."---- f ...... .' \ ''' ,•,__! . 0 i it ' CJ Ay/A y, I 1 0 ...,_ ....!-- . i . ,. . _ -. ii. Ilf11. • ( I . • ^ r ,• -0 oP I. ---''.-- -'----.------'7 - il . H , f ." 11: .---.._ ,A 11 , f_:-1- ..:*-----------. W il: f i i - CM ' ---; ---:... - . •(•::•=•; - 4 ..1 1---- 1 ' J • ;I - , -- - - -- - -1 ti 1 ' .. Rid :„.-. f /SO _____ ..__,.--- ... T I 1 11 1 . . . ,-- - • • i • ;. • • ... ISO ---.*". • : / W.111116„ . ., __________., 7. . fr. -- I k'-•,481. ',. \‘‘ ci c: - 1 1 : - s ' ' Li , ' 4 ::-.. --- --_:: ' -21 •_..t. . • ) . , :L., Z IflitdrOe. ___.7---t • ----_, „,..-----_/ ••-..--- .- ht - i . . -. / • • A .z..._ i__skV2P 1 1 .A ar 7 ...1# C ' ..„ 1 ../ v v •.( - - - BORLA . - - - . - -- dia.9 , . ,.-..--- 21 -_ - 7, -- 5 - - ---- 1 • --- _- 7 7T - ..- - - - -,72Wii, , (,•1' -* ..• - •";/,;."--\ \ -.• -,-_,__..-,), USGS TOPOGRAPHIC MAP BEAVERTON, OR & • = LAKE OSWEGO, OR QUADS 1 'i . I. N -.- 1 0 2000 4000 FT 1 I • ... j VICINITY MAP ,,..1 G EcDE)ESIGN, INC - 7 PACIFIC REALTY-2 MARCH 1998 FIGURE 1 .,•,•; 1=1. �� i w 2S; r rt -- EXPLANATION: Z BA o m % y ®8 0 BORINGS BY GEODESIGN, IN a o i \ (MARCH 1998) /FILL DEPTH (FEET) 01 ; TP 1 0 1 ' 11.0 TEST PITS BY CARLSON TESTING, INC. z - - - m ,' (APRIL 1997) /FILL DEPTH (FEET) y r 4' r J O � '' CL r , r y am . , ' W • ' I— / ,, //, ,, 4.' v) N ,,,,,:,,..... „..,E,... -__::: :: :::::::: :: „.: ,..7 77::=I 1 2„ . „,_,„_,: - --:::---- -I- -------- ------------- ----:::: -,--,::, ,,1;' : sue I r i v ' „,'''' t �' ■■�M=■ •i ' ' 8.0 � � ' fir `\ t �K s � - ._ ;; • ;,� \. ��, i� BUILDING B � ' `. y am. - - - \ "~ � - ■� ' TP -5 MN U TP -2�%".:----'• � : .11 jY ■ MEIN , ■S ■ b a 3.0 = x 7 11.4 �• =--- - - - - -- - --- --- � ' -'s ° \ . e s■■ 1 1� ' - 1 ' (). '' \ . \ , ,, . IM 1 MO , ', ` BUILDING A - - - \\ III: © TP -6 N cri V Wli \,, Wale .: �`� - �� �, �.� a �u 0 ��. - -__ �.� j a B-2 f W •r. ■ � ___ -i - 'k',_ • - - - — — - - --- ' ' ------- TP 3 iliNallill il ga \ '-. % '-, a:2', N C) of I ` \\ - ',I O \� • • _ 11 l- --- -------------- - - - - -- TP -7__ - -- - �x 0 60 120 FT - 111111 ,, , � .. ', AC -- ____ . -- - 0 , SS ss $5 • O 55 `-- - SITE PLAN FROM nRAWINC, PP wInin RV vi IIAY r-fmnici n rinI CAIrsIAICCOC - s - _ - . 1 ■t 1 . P.! APPENDIX A CARLSON TESTING, INC. TEST PIT LOGS 1 Carlson Testing, Inc. (CTI) prepared a July 10, 1997 preliminary geotechnical engineering report for the site. A copy of the report was provided to us by Mr. Dan Maloney of Pacific I Realty Ventures, Inc. The geotechnical engineering report included seven test pits (TP -1 through TP -7). The approximate location of the test pits is shown on Figure 2. A copy of CTI's test pit logs and their site plan are included in this appendix. 1 I, • 7 . .. I r 1 .1 t • . . GeoDesign, Inc. A -1 PacificRealty- 2:043098 ii—:,-.; :.....:..L'.. L.._.....- L-. ;:4----:: ;-.......„,,; 1, ___ . L......::. ',...L...,.... l.A... ■::i'w..- 3:, t=;l i'L'.. 200.0 , . , 150.0 . ' 7) 2 ' : , . Z' 100.0 , _ : - I c.) cri 1 , , ca. . 1 , , , ....... , .... ... A ....... 1 ........ , ..... , , , . ..... , ....... A 50.0 1 : : 1 , 0 _ . ..... ....: ............ 4 o ! , o 1 , 1 0.0 10 15 20 Embedment below depth of 15 feet (feet) Pier diameter --E-- 18" Downward Capacity —*-24" Downward Capacity —A-- 36" Downward Capacity ' - - o - - 18" Uplift Capacity - - .o - -24" Uplift Capacity - - tr -- 36" Uplift Capacity G E 0 DESIGN, I DRILLED PIER CAPACITIES N C . PACIFIC REALTY-2 APRIL 1998 FIGURE 3 APPENDIX A s CARLSON TESTING, INC. TEST PIT LOGS Carlson Testing, Inc. (CTI) prepared a July 10, 1997 preliminary geotechnical engineering report for the site. A copy of the report was provided to us by Mr. Dan Maloney of Pacific Realty Ventures, Inc. The geotechnical engineering report included seven test pits (TP -1 through TP -7). The approximate location of the test pits is shown on Figure 2. A copy of CTI's test pit logs and their site plan are included in this appendix. gf a 1 .P •f 2 '' t <d GeoDesign, Inc. A -1 PacificRealty- 2:043098 ri• . -A bEti a, f � � y + by y�Test P� No� P { � w � o ' f k:�- � ' � y as y.,,, axs ' R 5, i�»4'c°a ' ; a x . .r. x ° i w ', :l rr s . .1 hr s �, f r -' A µ -- i Pte" ++� A 1 .` r '1-t s F° s 4 " s' " 9 ` `4 S S ' 4 , p '3 *� + .... �' � Y � . : '>K. °`x,+'�S ✓ �..8 .r "`" r 7 `" .�,rp.,f'��„ x- " j. a^, s'r;� �a � ,T ��� �x; ,. . yet f _ D caeate X 4 „ 4 : ' `Lo edb, a�Bi3L f f v �� � � f ' � 'v3.,3� t,� ���,, �k�,'� "' r , " � ' �` 6s' ` e 'e!s � c �. 't�+ � a/s'�� . 'n� . s , ,,//�� �'�'�`'" � f .. �, a ry�: . x `iy1 .,fs»c/ y 'x . w"" "' ' X- . -e � z'� .»r ' :, 4 - .: ( .1 Lo ee a s ite pfa f . s ae N u r f a c e Ele � -. ,.:. , .. j ��."�:. �,� .,. r -`ate -s�,sf . s�_'fsrr 4s� ���,��"- r �...✓u, .�i, s ? ae � ,,.. ., .,.,. ,.. ... .+'n. 6x��.L r� 0 Q \ - E ` m — C rl 15 ° Q o Material Descr I o d O 0 - Grass sod layer with exposed concrete pieces 3' 3 1 - in diameter maximum Brown to dark brown SILT with some clay, gravel, asphalt, and 2 _ rock - Soft, moist to wet (soft fill) 3 � _ Gravel (crushed), wet ` 2 gal /min from gravel layer 4- L (Medium dense) 5 _ Compacted fill, consisting of brown /orange and gray SILT with some sand andclay 6 - Moist, hard (Hard fill) LI 7 - Dark brown clayey silt , moderately organic, some odor Soft to medium stiff - "1 8 - - 9- �� - Glass pieces .' 10- Contains some gravels and cobbles with bark pieces 11- (Soft to Medium fill) • Bottom of pit y 12- f • 13- y 14- - 15- 16- ` 17- • .rr S tr- - , _. a . , : - : . ---4- ,,,,--, - ,,,, ,=*,:. � ' i ., �", rat SY Si. - i t ems 9 ��g�of ester' f �gur ,A s? .,«. ,-..� ? � � � w �. v z Q ,R� -Sp G ±L 4 L � Carlson Testing, Inc. - P.O. Box 23814 - Tigard, Oregon 97281 - 684 -3460 - Fax 684 -0954 . . pl 4 • VI ' -• • - - 4c, .,:f., - ' - ,P,-:- ."' '' , ,,.• - , ---',.. . . ..,. • .'2 -T ak — ' - -' T ' l' s r.:,"•).ili , ,,, . ,? .!, . tn...'" ,!,, ,' Pts.-' lac . , . 0 -- - ,,,-,:- .4 . : • 71 ,..,,,„-.4-,,,.._-...., ..4„t„. ;kr --,-- ,, -, %,,,,,,,,,,,,- , fr ,, ;`.04,:i . 'n,, e''., '6 W- - , ,i', .4. 0, s , l'' v. _' .42----V,,-A::397,4:;xwo,., -:,-,.---,•1.7.• 1 "2". 4'. *kV - 10,-, - ,te ,.,: - -- -4v , "=, -- *Awl..40.*4- - ' --oor D tez3cca, :atU. ft.-, : ;*,- , - -a, ;,,,,.....— ,-,,,, • -:, -:, *;? -, 44. 1 . - A9ON:W. , ;;;:,,' -, ,, -5 qyggechbyaBp. , . ' , :,...„A.----,4, , -,•&,-- tf„,1-4.V. - t - s - e-v 0 : 4 V -* ( , -* ,, 41 . 3 , 40 - 04-4, 7:n, '-'% -, - , --, 'ie 0 ,,,. ,..,... , - , ,....., ,,, . ".3 ,, t, ' • -1r," 1 :ft 7-7 ,:r. 'lc V, ii%,'::..s.,:itri . ..,. : - "fiStufat . el .1 evauon;IPY~:494 -„0•14,:,- eel' tea 0A AfTAS r f. , *„.,./ . ' , '..-. - 4,,, -.Om*: -J-..,..10,.*-;„0,,t , 1-tr.titp.„ ---4A,,,;•, - „,....„5„ - - • — 0 a ) 0 _ ..„-, >, — r I ........ lii >- L_, ._ 0 f il ......./ `.., E ' ___ cE4 -,-,•., .„.a) I - I t'---- Material Description . - c ., fl ct i s- 0 0 Ti a) o a) -5 0 O 0 a. a. u) '— '•s16 6" grass sod layer .-- ] 1 - Dark brown SI LT with some clay _ Soft, moist 2- (Fill) 1 3 - ...--- — — — — Brown SILT with gravel, asphalt and occasional boulders 2:1 _ Moist, soft to medium stiff '1 4 - • 5 _ (Fill) ..... 1 Ji 6 -- — — — Brown / orange /grey SILT with some sand and clay Medium stiff, moist , ,... 7 - . ‘. 8 - ..4 ..,) _ 9- - (Fill) ,,.j 1 0 — — — — — — - Gray, sandy clay, mottled 11- Moist to wet (Posssble native) Bottom of pit ..1 _ • 12- no groundwater encountered 13- ' i 14- .,• 15- . _ 16- . , I _ 17- . . -.., , . ,..„ ....,,,,,,,,,,„., . : ' i, .:. .,,,,,,,,,. . .•;.-. , . - ,,,:-- - • --,- 4,- r-• -,,..- . ,,,..,...-_,,,,,:.0.-„,1,....4-7--.„ - ,-fr - J.4.21,...:.,,>f x .0,N,--- --,4 4.1 .11 , .,, ,. 1 • gg' t....'"; ''''' . 'rlj nqi, , ..1-,- , uo,a D. .,/: . - A - ,, ,,,. , .4-',A:„4";., t 4-.2-4:i. - au, „./wii- ' - • • ' ,-, 94'''',0 ' Kj ij WO" . • . , , , ,‘ 4 '''.... •-, • =-)-.. ola,..--f., - ' , - - 1'. -S OA, Carlson Testing, Inc. - P.O. Box 23814 - Tigard, Oregon 97281 - 684-3460 - Fax 684-0954 TESTING INS. C46. ••• , ,415,ulawAigh .4ti.417:71;5WWW44116,461005%. e 4„ , • - „rirt,:e ; • ' 5,135W' 4141.40FADatgEkda.Vated14-- '114,04iiiti-kg 77;ts:n S u r face fivAr‘isvato. Jourp„Iffeo'n, v1:47,7-,:,, 11 ?-i..*:,...snA, 1 t _a) 0_ EH a) c 2 D c cl) Cr) Material Description 0_ — 0 ttz. a) c C1) 0 0 o (cc (1) 0 0 6 grass sod layer — — — — — — 1 - Dark brown, SILT with some day, moist,soft Brown/orange, SILT sith some sand and clay 2 - Moist, medium stiff 3 4 - - Transition to sandy SILT 5 Transition to tan / orange silty SAND, moist to wet - 6 7 Transition to wet, 3 gal/min 8 Brown , soft 9 10 Bottom of pit 11- Groundwater at 7' 12- 13- 14- 15- 16- 17- 4 , -4 -es r fAb 0 1 L Carlson Testing, Inc_ - P.O. Box 23814 - Tigard, Oregon 97281 - 684-3460 - Fax 684-0954 INC rj ? ..... 7 r,v ,.,... zr vi isgiAwsi:i :tr,'' .:0, t t.5-,..0 ,.. "0' 1 ..w .:::..:.0tiNiVe: 10414 fe)e,":4 4 ,-.4,A, : • ::,'-.; : AK% --..-..-* ,,-,,....2 ,,,,,,„ t :F''' , SCA'4 6 4.:W.,:24*:,44' gdeitY., ....413D[445,1V ..e..z.s,. .: , .„, <--...:;..,:„.„,,, ..... , .1.44 . .. : 1,... - ip.3. • .." in :04 :,,: '~::„.- 0. , 4„ ,, , i,,P , ‘": 1 .,.<.',,,,, , e4...,' utiticeeva OTIZ:::001,0 , 1 k 4 -: Itivo 0 1 .--... — 2 cu D c 0 co Material Description eL -, (1) 0 = CD E Q) -- — 0 c c a .., _ TT .•,.. o a) as o 0 0 o_ a_ j 2 O0 :,,.. ::,.. - . p _,- 4D"agr Dark grass sod s I I a L y T e w r with cc i t hs oomeacsl clay, o a o a f t s , asphalt II mois t ...1: i 1 __ _ ___ .. _ ___ ___ -N- 1_, ..._ - _ 2 - 3 - Brown SILT with some sand Moist, medium stiff • 4 - 5 - 7 I i.,1 - 6 - •1 :LI 7- (Fill) l• 8 - I Transition to tan silty SAND, moist to wet, soft to medium stiff. (Native) 9 - Bottom of pit _ ! i , -,1 10- , T 11- ' 4 - 12- ,-• • ..f. - _•.i 13- . 14- , 4t . .•' 15- ..:. - 16- ,• _ ( 17- • „ . • ; ' ,•:,,•!..--,,?', ' , :..',--,-- ztv-weilm•pg. , .4 - ; f:„ ; : , .:44.;,;:ii . "ClieM:ViT"IMikTzier" ',5,, . 5 ;!::,17:- :',V Pi.:3":0 , 1 ' .. ''....,-,-- -;2144=:: LI:cVotiTeststPit4004 ,7 7,,.& , :)-3' , &19 ust - -.; '-, -42, •.,' - - . ‘445A4- ,... 4.e,::': ;r:- ,....-„,;4 --., .-40.11:u........0K: ., -...-.01' 'L : . : - ?..' cp•R_,,.1-SCO+ • , 41.011ECI: Carlson Testing, Inc. - P.O. Box 23814 - Tigard, Oregon 97281 - 684-3460 - Fax 684-0954 ii ; • ... V, „ # i ,,,,,•,, • ,, ,..r' ' 9. --'• . ;;;. '. - ' .,,,, '''''-;:""' '' * *sWaftitt‘...e.tW = .:, "V;t:p.' ttpit..:No .0 . f•_ ,,, , , A .-- ,-, t'4 ..1 ; .0,,..A ./.., „ - . : -..,t v r , . 01.1.. ,14 ; ,,,- ' , AZAar-nler'4,i.g9?' ..10i\,,Hnii1,7- - ' ,,,,..f.jt-;. At , 03%; .6 ....,,Ar,.,Lp#7,.0.0. :,--1 4.41 ,,, ii 47 e 4 g - i•,wg,..g',;S -4 7,,, , g,.„ , kc-i,,::<::-4 , v, , ,-,44:, :14,4,2 .vt -4,- rit , "'• .:,--, 4,=;' ' - — ; .,;;; 1... ..,..., -....,,, 9 ,,,,t,q ,,,,, ....e, ....e ,. , ,,,.....t, abS:rel*.'! 4,40i. Wt,. e.,,mxca3,„,a-w.p ‘: U'i, gZ;V,..4t --- 0.2:ciggeu . 46r , U0 IL/L= '' ' - W"If0 zp,.% 4 ..r (f a, -,:, .: 0,„ti 44 ,-;;;„,, 4,,„tte.4.- - 4vv ,...., 4 , 4.....44 4 ..w,/ 4 . ' 4 - ••,' , - • :••••4 • ',, , Ae• - •••• , ,Nr•rw•• - •• rov f ''....'x',0 ..-T 1,...„.041 lnt.tg-,4tt.amed*t*.4 „,,,, . 1,%!•• IZIffitAix, , ,: . . • , - ' '''''' A V" ' t'lla 4 gi4 ..' igk e ' ' -. slail ^TA Zi s4,54-.W ,..., , ,,,, . , —. CD • D >-. .., ._ — E H a) --- c . f• _ - .......- o_ "--.:.-.. Material Description 0 t 0_ 0_ Co 2 0 DI :i 6" Topsoil dark brown SILT with some clay_ Pil 1 - Brown SILT with some sand J a . moist, medium stiff 2- _ r _ .y• Brown sandy SILT with orange specks •:-A _ 5 - 6 - - Transition to silty SAND, moist to wet `.* 7 - 8 - (Native) 9- Bottom of pit 71 10_ .., , a - 1,. 11- • .4 ..... _ . 12- I - 13- . 14- - .--, 15- 16- -.1 17- ::. / : „„.„-. ‘4?. .:,,,---- zo, -, -; , 4 ,--"-74...''4'1ffirt%-lro..Al25,414;' estV r ''. 0,,,, '' ' 2,, ; '*''''' '- '' ' ' ° Z1 A. „,„,,, ,, *' 61 1 391 14,:'- ' .. ‘•:! * 1.&. , '' , , .. — . , ;., . , ,... ,.,x1 ,, , ,a., ‘_, tm, e.wew. , ,,.....,„ , .44 '''' - ' -''' ,•, ' - .-: ,,,e..,Ye'revors2.,..•• -.. ''•"•-• ' * "'AV -- X?, •••••.,••-•-•• „ - . • -<crt. Carlson Testing, Inc. - P.O. Box 23814 - Tigard, Oregon 97281 - 684-3460 - Fax 684-0954 S41. TEL:TIV INC • ri .. . • , ,.:1 , :4A-Ac - 1 40 ,92V1-0-00 ,4 g fet gitAnWadr.:1-' 1 W - 4. 4 1rr'trki'V''-' 44 4-r'n."Wc 1 4*UZZA;:'-iW 5 Pt 4 :'•VZ- 7 04 , 5itiVilffi-tiginV 4 -,,iVlo-,A1% - • 7ftot;:,,tiliv-W,....Aw."AlsexAH. tv.;:we.Aoz•,;41NiteS ,.'.f :1:- . , 0, ,, togge.cjkbytliBDE4.4.VbeilLviArm.A4 - .;. , 14,.twv-,yr iwt • .' 40 4:' kv't - 14..' , 7 , 4' , .*t;gaialtis,_.E0t4;, , - ,- -intli:02-Aa4, ,,,, v.-; . 2: ,, ,p , ---oolev . :.Vieliv106.,t , .. , 4''.;,..„.4 ,, ',',%•01 - ',1,,,,..iir.,0_,:.---.: ', -, ' -1..kfff-r* E-kx 40 . 4 . ...A.'40Vr . •,-W ,,, w&: , 4,. ,,.. r:<i.4:v;:w,o,, , %vOfst6 ,. ;v.;gv.f: 4 ?44r4z4 ,, a.vz: . :....v,.g,Vppg . g . w4.1 . 0;ca„;, 4 : ,. .e- 4 : . ,. %?-4,-.-4,4 , 3,--.4,4s44:44.;=:Atk..f.:44 , 074 . - --..4.44 .- Al, .7f 1 , ::4- -vs- - 4*"*Ii 4 ..' ',--.', ,,-- , ': 4 .'"'" , : 11 '-''''Ogie , ' , ' ''':TAM :X441 ...,2:,,...,i.,4, ,.,..„. eWr4r'' - , . , " 3 ' 4 ' ,4 '.; 4 .- - .W 'I *gallattarffggYAMPANVVAVAM$URKZ5gORP.:SAVi***4A:15.ea0A1Zr.."16*:44:1,P13::404tek.kMa:ASVAMA.40IR ...L , ....': .....-■ 0 u) . : •-• E I a) — c ..._.... — Material Description o_ a) 0 •:= co --• 7 •.,.., a) o c co L - ,- - 7, c a - o e) co 0 a_ cl_ CO 2 O0 6 " _ _ __glass/ sod 1 - Dark brown gravelly SILT, moist, soft (Fill 2 _ 7 _ ,– - ,., Brown sandy SILT, compact, moist I 3 - ',.... ' 4 - . - (Fill) 7 5 — Brown and grey, sandy SILT,moist, hard, 6 - (Native) Bottom of pit - . i 8- • 1 L ?..._.: - 9- 10 - -, ' t ,... - ,..... - 11- 12- i - _ 13- 14- • . 15- -.; 16- j 17- , - . . . ; -„, ,..,,. ,-.‘,. , ,,,,,,,• ._„,... ,..,.,,, .,„ i . ,..,.,;, --; ,,,:-..-. ', -. - ......x._„ ,..'",* ,V ]:1.04 ,_... , ., 17, _ .4 _ , ,_ .,„, ., , . , ''" ''''''' • 17 - IP -''''' "''''''"'•'''T A - 4 A '''''''' >;•ris7 -...,1e0(34-.4, ..:..41vizi440-i.i,t,.." laff*,0*.4,... '''-.;.';'.:-,'. : -,%ggv*:642i4P.;04`...:it 4P..4 -;a4k144-.,4 _Ir. . . - Carlson Testing, Inc. . - P.O. Box 23814 - Tigard, Oregon 97281 - 684-3460 - Fax 684-0954 mi .ic. ; • . 3 r -1 0, ) ;741-11Toit c,.. , .! • Atok*.. 1.: , 4z,FiLqi 71 7 ;1411,14:; : tres*saritAit,, '• - ' ,-7,1- i'%4SIt'j:w- - 'kg;' , ,,,S ,- ..1=',471/7,-*Stk.,,K.,q , z_....:) , tri - ; ' ? 40, :,. ..,. 4 :■41' • ..O 40a4a =, ' 1 ? ..:4. - ' '','.' ' :''' • ':.71 ',.: kiLltiggediby4BDItki:;... froff„.1.,,4-4o .-- , -.*: mati , - 4 ,uE4,-. , -- 1 , ,,, .W:',4%., "I . ..,ilt ' .. ., . ...■: . ^'%/ :, ' >W W ' l''''Z' .-'-n - - ' "'" -P - '' ;Fflibe at d.riaSe:e z i' it&viara ,:. •.„,,,:: Vfefijulw,v4.*',' ,, P' , :' - -, Ave,,....„ - - , 5*..burjace;Lievation:t 4 tittWlaftP•mVi--; , 0 - ': .1 %., w , - 5.;:.:. m„ ' ` A-e 1, ^ , s . ,, -.W , "*::: - L.. 0 . rei .—.. 0 >-, 0 ,„ )‘‘ , E ...., ., c ...--.. :i — ... o a) — c o co 0 — : • D M ater i al Description ..c -: _ - M ci) a 4=- .(r) -- ---.. 1 cp 0 c o cy ca o c , n_ a_ (1) 2 O0 — — 6grass/ sod :., ,:. ,-, ] 1 - Gravelly SILT with occasional cobbles (large), loose, moist 2 - 1 - 3 - Gray SAND, medium dense, moist 4— _ Brown, sandy SILT, wet, soft 5- 77 . - Groundwater estimated at 2-3 gal/min 6 - _ Trans to very stiff at 6.5' '.......i 7 - 8 - - 9 - - 10- - t 1 1 - .._.: - . 12- ) ii - .J. 13- . — 1, 14- 15 1 6 - ' l . LI 1 7- ! . : ,...i tefi . ..;=Gg-09.14 AbitoToftirestgPitecsom,v.fe. 44, re:1-A ° 3, , , 7' '''''.',,,, --, • , ,," .,:,,...,,,, -,...,,,, ,...d ::T v su-so Carlson Testing, Inc. - P.O. Box 23814 - Tigard, Oregon 97281 - 684-3460 - Fax 684-0954 6IdIS TESTItIG INC Post -It' Fax Note 7671 Date OA, IPeces� / To ' � � F i c 0''Qy Co./Dept. Co. (76 41 Phone @ /?S:. XI Z Phone It Fax a Fax 0 � vv 2 Z17/ • • N O O 7 APPENDIX B i FIELD EXPLORATIONS AND LABORATORY TESTING FIELD EXPLORATIONS General Subsurface conditions at the site were explored by drilling five borings (B -1 through B -5). The approximate locations of the explorations are shown in Figure 2. Exploration locations were Y chosen based on a site plan provided to our office by Mr. Dan Maloney of Pacific Realty Ventures, Inc. 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. Crisman Drilling of Tualatin, Oregon drilled the borings on march 9 and 10, 1998, using mud rotary drilling methods. The depths of the explorations ranged between 26.5 to 42.0 feet below the exiting ground surface. The explorations were observed by a member of our geotechnical staff. We obtained representative samples of the various soils encountered in the explorations for geotechnical laboratory testing. Classifications and sampling intervals are shown in the boring logs included in this appendix. Soil Sampling Samples were obtained from the borings using a 1.5 -inch ID split -spoon sampler in general accordance with ASTM D 1586. The split - barrel samplers were driven into the soil with 140 -pound hammer free - falling 30 inches. 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 in the boring logs, unless otherwise noted. Relatively undisturbed samples were obtained ° using a standard Shelby tube in general accordance with ASTM D 1587, the Standard Practice for Thin- walled Tube Sampling of Soils. Soil Classification The soil samples were classified in accordance with the "Soil Classification Guidelines" and „y "Key to Test Pit and Boring Logs Symbols," copies of which are included in this appendix. The boring and test pit logs indicate the depths at which the soils or their characteristics change, although the change actually could be gradual. If the change occurred between sample locations, the depth was interpreted. Classifications and sampling intervals are shown in the boring logs included in this appendix. LABORATORY TESTING Classification and Moisture Content The soil samples were classified in the laboratory to confirm field classifications. The laboratory classifications are included in the logs if those classifications differed from the field classifications. GeoDesign, Inc. B -1 PacificRealty- 2:043098 7, : 1 .1 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 soil in a r 1 • test sample and is expressed as a percentage. The moisture contents are included in the t Togs presented in this appendix. We tested selected soil samples to determine the in -situ dry density. The tests were performed in general accordance with ASTM D 2937. The dry density is defined as the ratio -- of the dry weight of the soil sample to the volume of that sample. The dry density typically is a expressed in pounds per cubic foot. The dry densities are included in the Togs presented in this appendix. 9 Consolidation Testing A one - dimensional consolidation test was completed on one relatively undisturbed soil A samples obtained from the explorations. The tests were conducted in general accordance with ASTM D 2435. The test measures the volume change (consolidation) of a soil sample under predetermined loads. The results of the consolidation testing are included in this i appendix. 7 4 , r 1 A t . i 4 . A • t 1 1 �f i mi GeoDesign, Inc. B -2 PacificRealty- 2:040398 a Key to Test Pit and Boring Log Symbols 1 [I Location of sample obtained in general accordance with ASTM D 1586 Standard Penetration Test •,:� m • Location of SPT sampling attempt with no sample recovery A Location of sample obtained using thin wall or Shelby tube sampler • Location of thin wall or Shelby tube sampling attempt with no sample recovery A Location of sample obtained using Dames and Moore sampler and 300 pound hammer ],': M Location of Dames and Moore sampling attempt (300 pound hammer) with no sample recovery 14 Location of grab sample i4 Water level Blow count = number of blows required to drive the sampler 12 inches Soil Classification System Group Symbol Group Name GW well graded gravel, fine to coarse t GRAVEL CLEAN GRAINED GRAVEL GP poorly graded gravel SOILS More than 50% silty gravel t of coarse fraction GM retained o GRAVEL No. 4 Sieve WITH FINES GC clayey gravel More than � 50% SW well graded, fine to coarse sand °_ retained on SAND CLEAN No. 200 SAND SP poorly graded sand Sieve More than 50% of coarse fraction SM silty sand passes SAND No. 4 Sieve WITH FINES SC clayey sand ML low plasticity silt SILT and CLAY INORGANIC FINE GRAINED Liquid Limit CL low plasticity clay SOILS less than 50% ORGANIC OL organic silt, organic clay More than MH high plasticity silt, elastic silt e 50% SILT and CLAY INORGANIC ' passes high plasticity clay, fat clay No. 200 Liquid Limit CH Sieve greater than 50% ORGANIC OH organic clay, organic silt , —4 HIGHLY ORGANIC SOILS PT peat j , ,. GEO INC. i� ( I t 1 R+' -Y +'u� _�}��� ,y.�....u�. ( � 6!✓: .... ... Soil Classification Guidelines Granular Soils Cohesive Soils Standard Penetration Standard Penetration Unconfined Relative Density • Resistance Consistency Resistance Compressive Strength (tsf) very loose 0-4 very soft less than 2 less than 0.25 loose 4 -10 soft 2-4 0.25 -0.50 medium dense 10 -30 medium stiff 4 -8 0.50 -1.0 dense 30 -50 stiff 8 -15 1.0 -2.0 very dense over 50 very stiff 15 -30 2.0 -4.0 hard over 30 over 4.0 Grain Size Classification Boulders 12 -36 inches Subclassifications Percentage (by weight) of other Cobbles 3 -12 inches material in sample Gravel 3/4 - 3 inches (coarse) Clean 0 - 2 1/4 - 3/4 inches (fine) Trace 2 - 10 Sand No. 10 - No. 4 sieve (coarse) Some 10 - 30 No. 10 - No. 40 sieve (medium) Sandy, Silty, No. 40 - No. 200 sieve (fine) Clayey, etc. 30 - 50 • Dry = absence of moisture, dry to the touch; Moist = damp, without visible moisture; Wet = saturated, with visible free water. GEODESIGN, INC. ; t Job Name: Pacific Realty-2 Location: Tigard, Oregon Log of Boring B -1 Drilling Date: 9 March 1998 Depth, Feet Sample Location Soil Description Laboratory Tests 0 .Y ML- Soft to medium stiff, brown sandy SILT FILL FILL with trace organics; moist, 6-inch- thick root zone. Moisture content = 33.1% 4 r 5 - E 5 Moisture content = 33.2% - :: 4 ML Medium stiff to stiff, brown SILT with some sand moist. 10 Moisture content = 30.5% [I 10 ML Stiff, brown SILT with some to trace sand _ and occasional gravel; moist. 4 Moisture content = 71.0% Grades to with some organics. Dry density = 57.3 pcf • 15 Moisture content = 22.7% 36 _ SP/ Dense, brown SAND with trace silt; moist. { - = =� GW - Dense, brown sandy GRAVEL with some GM silt; moist. Jr. - -- - GW Dense, brown sandy GRAVEL with trace 20 silt; moist. - = 32 IMINNIMAIMMIN 25 $ (continued on next page) • EODESIG I fVC_ GDI document: Pacific Realty -2 boring va Job Name: Pacific Realty-2 • Location: Tigard, Oregon Log of Boring B -1 Drilling Date: 9 March 1998 Depth, Feet Sample Location Soil Description Laboratory Tests 25 SM/ Dense, brown silty fine SAND to hard Moisture content = 30.0% 7 43 ML sandy SILT; moist. 30 .,.......,...,.. F SW Medium dense, gray coarse SAND with Moisture content = 34.0% trace silt and occasional cobble and gravel; Dry density = 92.1 pcf moist. ML Stiff to very stiff, gray SILT with trace sand; 35 moist. Moisture content = 37.6% 26 A 40 22 } Boring completed at 41.5 feet. 1 . • GEGIESIGN, INC_ GDI document: Pacific Realty -2 boring logs.pub Job Name: Pacific Realty -2 Location: Tigard, Oregon Log of Boring B -2 .a Drilling Date: 9 March 1998 f • Depth, Feet Sample Location Soil Description Laboratory Tests '.r A. 0 -- GP- Dense, brown GRAVEL FILL with trace silt - FILL and organics; moist, 4- inch -thick root zone. _ ML- Dense, brown SILT FILL with organics; :4 FILL moist. . _ Moisture content = 21.9% 17 5 ML Very s, F 1 moist, buried oftbrown root zone. SILT with some organics; Moisture content = 40.4% u ML Very soft, gray SILT with trace organics; moist. - ',;` - ML Medium stiff, gray and brown mottled SILT Moisture content = 28.3% 7 with trace sand; moist. 1 21 ML Very stiff, brown and gray mottled SILT t _ with trace sand; moist. .x Moisture content = 27.8% - ;OM ∎IIIII GM Dense, brown silty GRAVEL with trace 12 ►IIIII sand; moist. WIN 15 PII/II 24 SW- Medium dense, brown SAND with some SM silt; moist. �C - : :: :::I ;WIN ►IIIII - ►IIIII GM Very dense, brown silty GRAVEL with ►IIIII 20 some sand; moist. ►IIIII Moisture content = 31.2% ►IIIII • , - ;OM ►IIIII 77 11111111111 ML L Very stiff, brown SILT with some sand; WIN WIN moist. . - WIN ►IIIII = ►IIIII GM Dense, gray -black silty sandy GRAVEL; ►IIIII moist. 25 WIN (continued on next page) E E CD IE) ES 1 G NJ, 1NC- :t GDI document: Pacific Realty -2 boring • f ya — 11 Job Name: Pacific Real-2 Location: Tigard, Oregon Log of Boring B-2 Drilling Date: 9 March 1998 ;.,..T Depth, Feet Sample Location Soil Description Laboratory Tests 25 ri ;$$$$ WOO/ GM Dense, gray-black silty sandy GRAVEL; $ 30 moist. 711 dukee... „ A ] Boring completed at 26.5 feet. 1 1 : ...:1 1 .:.'.,i , ..i ,..1 ..4. 3. A ... ...; i _I C..4 EC) IDoEsirv, INc.. ..',.1 GDI document: Pacific Realty-2 boring logs.pub h 6 AiT.A■ Job Name: Pacific Realty -2 Location: Tigard, Oregon Log of Boring B -3 Drilling Date: 9 March 1998 Depth, Feet Sample Location Soil Description Laboratory Tests 0 ML- Soft to medium stiff, brown -red SILT FILL FILL with large oxidized nodules and trace organics; moist, 6- inch -thick root zone. ,.4 Moisture content = 33.0% 4 5 Moisture content = 37.3% ,r_ [I 5 ML Soft to medium stiff, brown sandy SILT; moist. • 111 Moisture content = 35.1% 4 10 Moisture content = 36.5% 4 SM Medium dense, brown silty SAND; moist. II 17 15 fit• 52 ►IIIII GM Dense, brown silty sandy GRAVEL, moist. ►IIIII ►IIIII _ ►IIIII ►IIIII PIT 1, / MU Interbeded medium stiff to hard gray SILT, . SM/ medium dense to dense silty SAND and 20 GM silty GRAVEL; moist. Moisture content = 29.9% P Dry density = 94.0 pcf 25 (continued on next page) EC) IESIGN, IIJC_ .P k.. GDI document: Pacific Realty -2 boring :ct r 2 '' Job Name: Pacific Realty -2 Location: Tigard, Oregon Log of Boring B -3 Drilling Date: 9 March 1998 Depth, Feet Sample Location Soil Description Laboratory Tests , 1 25 MU Interbeded medium stiff to hard gray SILT, Moisture content = 29.8% SM/ medium dense to dense silty SAND to silty GM GRAVEL; moist. ML Very stiff, gray sandy SILT; moist. 30 1 [1 r 35 Moisture content = 32.7% • Ill :: 26 • - 40 Moisture content = 26.4% P Dry density = 102.4 pcf _ i Boring completed at 42.0 feet. 1 :i i ,;z f .t GE CD C) ES I G NJ. INIC_ 4, GDI document: Pacific Realty -2 boring logs.pub nae D , — 7 Job Name: Pacific Realty-2 Location: Tigard, Oregon Log of Boring B-4 1 Drilling Date: 10 March 1998 Depth, Feet Sample Location Soil Description Laboratory Tests r.x 0 - - -- ML - Soft to very stiff, gray -brown SILT FILL with _ - FILL some gravels and occasional wood chips; "t _ moist, 8- inch -thick root zone. a _ Moisture content = 52.3% „ 18 i 5 Moisture content = 41.2% i , , _ {I 12 ML - Soft, gray SILT FILL with trace organics '1 _ FILL and occasional wood; moist.; moist. Moisture content = 52.7% 2 "S 10 '' n P Moisture content = 31.5% .. n - Freee4 i Dry density = 100.5 pcf PIIII1 GM Medium dense, brown silty sandy - WIN ' IIIIII GRAVEL; moist. .t ►IIIII :,;1 15 ►IIIII *OA 26 - IIIIII ►IIIII ►IIIII ..4 : IIIII WIN ►IIIII WIN WON ►IIIII - WIN ►IIIII ►IIIII 20 ►■■■■■ IIIIII Moisture content = 18.0% IIIII zs -` :IIIII ►IIIII - ►IIIII ►IIIII ►IIIII 1 1 1 2 I • (continued on next page) .i GEODESIGIV, INC_ GDI document: Pacific Realty -2 boring I Fl Job Name: Pacific Realty-2 . Location: Tigard, Oregon Log of Boring B-4 Drilling Date: 10 March 1998 _1 . Depth, Feet Sample Location Soil Description Laboratory Tests : I • 25 ,,,$ I$SS GM Medium dense, brown silty sandy - 34 GRAVEL; moist. - 1 ; : .4 MU Very stiff to hard, gray sandy SILT with _ SM interbeded coarse gray silty SAND; moist. ,j - 30 21 ---/--- ML Very stiff, gray SILT with trace sand; most `` - to wet. 35 Moisture content = 31.9% - 17 F : Boring completed at 36.5 feet. :. 7 A 4t GEOEESIGIV, INIC_ e GDI document: Pacific Realty -2 boring logs.pub 7 I : fl . ti !,4 Job Name: Pacific Realty-2 Location: Tigard, Oregon Log of Boring B -5 Drilling Date: 10 March 1998 Depth, Feet Sample Location Soil Description Laboratory Tests t 0 ML- Soft to medium stiff, red -brown SILT FILL FILL with some wood debris and oxidized ; . s - nodules; moist, 8- inch -thick root zone. , a - Moisture content = 30.0% ..b 7 3 5 Moisture content = 39.1% ,!-1 _ l 5 .._-- i — ML- ' Very soft, gray SILT FILL with organics; Moisture content = 103.5 - FILL moist. i P - wee4 Moisture content = 24.0% j$ $$���� $ GM Medium dense, brown silty sandy 7 10 �� 6 GRAVEL; moist. ... ML Medium stiff, gray to brown sandy SILT; moist. 1 _ 4 7 1 Moisture content = 39.5% 11 7 ML Medium stiff, gray -green SILT with trace sand and some organics; moist. Consolidation test - p Moisture content = 42.1 • Dry density = 80.9 pcf 20 Moisture content = 33.3% 9 f WIN PIIIII GM Dense, brown silty sandy GRAVEL; moist. 25 (continued on next page) CEO INC_ t GDI document: Pacific Realty-2 boring ° Job Name: Pacific Realty-2 Location: Tigard, Oregon Log of Boring B -5 Drilling Date: 10 March 1998 rye Depth, Feet Sample Location Soil Description Laboratory Tests A 25 GM Dense, brown silty sandy GRAVEL; moist. ►I/III 39 _ ►IIIII ►VIII ML Stiff to very stiff, gray SILT with some sand; moist. 30 13 1 f 3 Moisture content = 34.0% 29 Boring completed at 36.5 feet. . .r • J f { . A EGEDESIGIJ, IIVC_ I GM document: Pacific Realty -2 boring logs.pub r 1 A o.00 — . -. 0.05 - - - -- —= —; ,,,]',- L L Z O . . , ;::::1 0 , ., , . : O �� ' co - • • - - - - 0 O • O . 0.10 • t i. . i ' • . i , 0.15 : : 100 1,000 10,000 100,000 5 PRESSURE (psf) SAMPLE INITIAL INITIAL 1 BORING DEPTH SOIL MOISTURE DRY DENSITY KEY NUMBER (FEET) CLASSIFICATION CONTENT (pcf ) P.' : B 5 17.0 Medium stiff, gray -green SILT with trace 42.1 80.9 fine sand; moist (ML) _j ., GEODESIGN, INC. CONSOLIDATION TEST RESULTS ticis A • u/ 7`/A A ". / / p GEc DESIGN, INC. S# 7OO GEOTECHNICAL, ENVIRONMENTAL, AND GEOLOGICAL CONSULTANTS ilLE t S ! COPY X11, / td/d- a& P4Sk • / A 6Agyl, 4/TY (P aAJT- 4 / cce (\\'‘/' • ;I REPORT OF GEOTECHNICAL ENGINEERING SERVICES 74 AVENUE INDUSTRIAL PARK SITE TIGARD, OREGON • FOR PACIFIC REALTY VENTURES, INC. _.s 17400 S.W. Upper Boones Ferry Rd., Suite 230 • Portland, OR 97224 • (503) 968 -8787 • Fax (503) 968 -3063 few percentage points above optimum moisture content. A 12 -inch thickness of imported granular material generally should be sufficient for Tight staging areas and the building pad but is generally not expected to be adequate to support heavy equipment or truck traffic. Haul roads and areas repeated heavy reas with re eated heav construction traffic should be constructed with a minimum thickness of 18 inches of imported granular material. The imported granular material should consist of crushed rock that has a maximum particle size of 4 inches, is well graded and has less than 5 percent by weight passing the U.S. Standard No. 200 Sieve. We recommend that a geotextile be placed as a barrier between the subgrade and imported • granular material in areas of repeated construction traffic. The geotextile should have a minimum Mullen burst strength of 250 psi (pounds per square inch) for puncture resistance and an AOS (apparent opening size) between an U.S. Standard No. 70 and No. 100 Sieve. As an alternative to placing 12 to 18 inches of granular material, the subgrade can be stabilized using cement amendment. If this approach is used, the thickness of granular material in staging . areas and along haul roads can be reduced to 6 inches. This recommendation is based on an assumed minimum unconfined compressive strength of 200 pounds per square inch (psi) for subgrade amended to a depth of 12 inches. Cement amendment is addressed below under the "Soil Amendment" section of this report. GROUNDWATER CONSIDERATIONS Groundwater was observed at depths of 4 and 7.5 feet and may raise above these levels • during extended wet weather. We recommend that foundation drains be installed at this site. The foundation drains should be installed at least 2 feet below the finished floor grade, constructed at a minimum slope of about 1 /2 percent and routed to a suitable discharge • (e.g., connected to the storm drain system). The foundation drains should consist of 6- inch - diameter perforated drainpipe embedded in a minimum 3- foot -wide zone of drain rock. The drain rock should be wrapped in a geotextile filter. The drain rock should be uniformly graded, have a maximum particle size of 3 inches and have less than 2 percent passing the U.S. Standard No. 200 Sieve. The geotextile should have an AOS between the U.S. Standard No. 70 and 100 Sieve and a water permittivity greater than 1.5 sec'. STRUCTURAL FILL General • All material used as structural fill should be free of organic material or other unsuitable materials and particles larger than 3 inches in diameter. On -Site Material The on -site materials consist of silt. Silty soils are generally sensitive to small changes in moisture content and are difficult, if not impossible, to compact adequately during wet weather or when their moisture content is more than a few percentage points above the optimum moisture content. Laboratory testing indicates that the moisture content of the on- site materials are considerably greater than the anticipated optimum moisture content required for satisfactory compaction, which, based on our experience, is approximately 16 GeoDesian, Inc. 6 PacificRealty- 2:043098 `1� Iy • 4 I I f'll Ar' cent. Therefore, moisture conditioning will be required to achieve f th ua t e s to pac ter al a 'I, We recommend using imported g per ranular material for struct I ii': cannot be properly moisture - conditioned. As an altemativeN'h a o cement or lime material f as structural fill may be acceptable if it is properly amended p r'I I When used as structural fill, the on -site material should be placed in lifts with a maximum uncompacted thickness of 6 to 8 inches and compacted to not Tess than 92 percent of the ,, I "', ill maximum dry density, as determined by ASTM D 1557.E l Imported Granular Material Imported granular material for run rock, crushed rock, or structural fill should be pit or quarry- material . ;1l , crushed gravel and sand. It should be fairly well- graded between coarse and fine mate and have less N than 5 percent by weight passing the U.S. Standard No. 200 Sieve. The , v I � 1 . material should be placed in lifts with a maxlmum d ; pa den d s ty as determined by ASTM compacted to not less than 95 p ercent of the max I D 1557. During the wet season or when wet subgrade conditions exist, the initial lift shout be a proximately 18 inches in uncompacted thickness and should be compacted by rolling P with a smooth drum roller without use of a drum vibrator. t ranular Trench Backfill Trench backfill for the utility pipe base and pipe zone less than g yweightgpassing material with a maximum particle size of 3 /4 inch the U.S. Standard No. 200 Sieve. The material should be free one should organic matter, and , to � � • ,� other unsuitable materials. Backfill for the pip e base and p p at least 90 percent of the maximum dry density, as determined by ASTM D 1557, or as i�' recommended by the pipe manufacturer. Within building and p kfill 2 percent pavement areas, ASTM as, trench 1 h bac ac at � placed above the pipe zone should b f shed subgrade l and east as recommended for structural fill depths greater than 2 feet below i e zone within 2 feet of finished subgrade. In all other areas, maximum dry de tyoas detepmined by should be compacted to at least 90 percent of the ASTM D 1557. Soil Amendment erienced contractor may be As an alternative to the use of imported granular a obtain suitable support properties. It able to amend the on -site soils with portland cement to Is generally less costly to amend on -site soils than to rem aed and replac ri s oft oil with granular material. Based on the moisture contents, sot types amendment would be more suitable at this site than lime amendment. Cement amendment should not be used if runoff during co t oftion can -a not beedirected soil away from adjacent wetlands or Fanno Creek. The permeability xtr Y emel low. Because of the low permeability, cement r e h dm e bes should n tro be c completed in landscape areas, or, the cement-amended material 'landscape a areas prior to planting. In addition, there is a risk rain wat can p within in sug the floor slab base rock over slab Trap water cement-amend can oesult in s lab curling, ex floor trapped water under the fl PacificRealty- 2: 043098 GeoDesign, Inc. 7 f le slab moisture and damage to flooring. W e recommend that cement - amended subgrade if , , under building areas be sloped at a minimum of 0.5 percent, with the water collected at the p perimeters of the building and routed to a suitable area and discharged away from building. !' j!I Cement amendment should not be attempted in basement floor slab areas. . 11I',, Successful use of soil amendment depends on use of I correct techniques and equipment, soil � , i, moisture content, and the amount of cement added to the soil. The recommended 4 percentage of cement is based on soil moisture contents at the time of placing the structural ; i P ;� fill. Based on our experience, 3 percent cement by weight of dry soil can generally be used 7 when the soil moisture content does not exceed approximately 20 percent. If the soil 9 moisture content is in the range of 25 to 35 percent, 4 to 6 percent by weight of dry soil is :I . 1 ,. recommended. It is difficult to accurately predict field performance due to the variability in soil vi response to cement amendment. The amount of cement added to the soil esign pu poses we !� adjusted based on field observations and performance. For preliminary 1 recommend a minimum of 5 percent cement and a treatment depth of 12 inches. �,, • zi It is not possible to amend soils during heavy or continuous rainfall. Work should be .:r4! completed during suitable conditions. PERMANENT SLOPES General roads , and Permanent cut and fill slopes should not the top f c Buildings, II slopesS The s pavements should be located at least 5 feet from should be planted with appropriate vegetation to provide protection against erosion as soon as possible after grading. Surface water runoff should be collected and directed away from slopes to prevent water from running down the face of the slope. Fanno Creek Fanno Creek. Building A will be located approximately 5 feet from the top of a slope d w n to approximately The slopes down to Fanno Creek are relatively steep, varying e movement. 1 H:1 V to 11/2H1 V, and contain areas with evidence of prior slope is approo 20 feet Based on topography included in Figure 1 of CTI's report, high. e adequate along Fanno In our opinion, the 5 -foot setback recommended above n the streams slopes, the steepness Creek because of the variable fill material ob served opes. We recommend = of the slopes, and the potential for stream erosion of the t o P the s ope l as defined by 2H 1V locating all buildings a minimum of 5 feet from the top ities may plane that extends upward from the toe of the the se ka e o mmended a and be damaged if these elements extend beyon d he mod feed -. slope movement occurs. Embedded spread foundations or drilled piers will be required if retaining wall footi gs be this plane. Under this condition, we recommend that building and embedded such that the outer edge of the footing is a minimum o of over al distance feet will be feet from the 2H:1V plane. Based on our estimates, an 4,y �/ PacificRealty 2:043098 V 8 =Y. GeoDesign, Inc. necessa ry along the west side of Building A to adequately found the footings outside of the n 1 ! Ill' recommended setback. In addition, the embedded wall of the footing should be designed 11 as a retaining wall with the free -face defined as the portion of the wall between the ground � surface and the intersection of the wall with the above - referenced 2H:1V plane. Our design ; , ;j recommendations for retaining wall are provided in the "Retaining Structures" section of , II this report. i ' An alternative to embedded footing is the use of drilled piers to support the western -most y i edge of Building A. Provided the drilled piers are installed at a maximum spacing of 4D, where D is the diameter of the pier, loss of soil from slop instability should not undermine , the floor slab because of arching between the piers. However, shoring will need to be wi , installed between piers if slope movement exposes the drilled piers. Our recommendations "i for drilled piers are provided in the "Deep Foundations" section of this report. '' ii :9 SHALLOW FOUNDATIONS ; Introduction There is a risk of excessive differential settlement because of the variable thickness and consistency of the fill materials at the site. Options to reduce the include deep embedment of foundation element, granular pads and drilled pier foundations. Our recommendations for the buildings A and B are provided in the following paragraphs. Building A Because of the small setback and steep slopes between Building A and Fanno Creek and the thick deposits of fill in this area, it is our opinion that the western edge of Building A should be supported on drilled piers or on deeply- embedded footings. Our recommendations for drilled piers are provided in the "Deep Foundations" section of this report. Our recommendations • for the embedment depth of the footings are provided in the "Cut and Fill Slopes" section of this report. We recommend that footings be sized based on an allowable bearing pressure of 1,500 psf. To further reduce the risk of excessive differential settlement, we recommend that the footings be underlain by minimum of 2- foot -thick granular pads and that the perimeter of the building be supported on continuous footings. Building B With the exception of at B -2, the fill observed in the explorations completed in the area of Building B (B -1 through B -3 and TP-4 through TP -7) consists of relati firm trial a However, an approximately 2- to 3 -foot thick layer of very soft m aterial was depth of 5 feet at boring B -2. To reduce the risk of excessive differential settlement associated with the variable fill thickness, we recommend that footings be sized based on an allowable bearing pressure of 2,000 psf. To further reduce the risk of excessive differential settlement, we recommend that the footings be underlain by a minimum footings. 2-foot-thick granular pads and that the perimeter of the building be supported i . ..i ..{ GeoDesign, Inc 9. PacificRealty 2:043098 : r 4?7 7 b j i )� 1 Granular Pads The granular pads should extend 6 inches beyond the margins of the footings for every foot excavated below the bottom of the footing. The granular pads should consist of crushed rock or crushed gravel and sand that is fairly well - graded between coarse and fine, contain no ` organic matter or other deleterious materials, have a maximum particle size of 2 inches, and have less than 5 percent passing the U.S. Standard No. 200 Sieve. The imported granular material should be compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557, or, as determined by one of our geotechnical staff. We recommend that a member of our geotechnical staff observe the prepared footing subgrade. General The bearing pressures described above apply to the total of dead and long -term live Toads and may be increased by one -third when considering earthquake or wind loads. These are net bearing pressures; the weight of the footing and overlying backfill can be ignored in calculating footing sizes. Isolated column and continuous wall footings should have minimum widths of 24 inches and 18 inches, respectively. With the exception of the embedment recommendations for the Building A, the base of exterior footings should be founded at least 18 inches below the lowest adjacent finished, grade. Interior footings can be founded 12 inches below the bottom of the floor slab. It is difficult to accurately estimate the settlement at the site because of the variable nature of • the fill materials at the site. Based on the subsurface conditions observed, consolidation test results and our settlement analysis, we estimate that total and differential settlements will be less than 1 and 'A inches, respectively. These estimates are based on the assumption that the floor slab live Toad is less than 150 psf and less than 2 feet of fill is required to achieve final grade. Total and differential settlements could exceed 3 and 1% inches, respectively if the floor slab live Toads approach 250 psf. DEEP FOUNDATIONS One alternative discussed above is to support the western wall of Building A on drilled piers. Allowable capacities, both downward and uplift, for 18 -, 24- and 36 -inch diameter drilled piers are presented in Figure 3. The capacities include a safety factor of 2.5 for end bearing and 2 for skin friction. The embedment depth referenced in Figure 3 is the embedment below a depth of 15 feet. Accordingly, the total pier lengths referenced in Figure 3 vary between 25 and 35 feet. Lateral capacities of the drilled piers will be provided following the selection of the pier diameter and embedment by the structural engineer. Drilled piers will undergo negligible settlement provided the bottoms of the pier shafts area cleaned adequately. If pier capacities greater than the values shown in the graph are required, the specific application should be reviewed by our office. t • GeoDesign, Inc. 10 PacificRealty- 2:043098 I: :: it.4-7,7 - . -.-7- L d iI 1 li I ' I fi ll FLOOR SLABS Satisfactory subgrade support for building floor slabs supporting up to 100 psf area l oading can be obtained on medium stiff to stiff silts or on structural fill underlain by medium stiff to ,, stiff silts. A 6- inch -thick layer of imported granular material should be placed and compacted over the prepared subgrade to assist as a capillary break. Imported granular material should •, i be crushed rock or crushed gravel and sand that is fairly well- graded between coarse and ,1, fine, contain no deleterious materials, have a maximum particle size of 1 inches, and have t less than 5 percent by weight passing the U.S. Standard No. 200 Sieve. The imported ; t 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. b. A subgrade modulus of 150 pci (pounds per anticipated ated d used and la as Settlement of floor slabs supporting P recommended is not expected to exceed '/2 inch. 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. RETAINING STRUCTURES Our retaining wall design recommendations are based on the following assumptions: (1) the walls consist of conventional, cantilevered retaining walls or embedded building walls; (2) the walls are Tess than 15 feet in height; and (3) the backfill is level, drained, and consists of imported granular materials. Reevaluation of our recommendations will be required if the retaining wall design criteria for the project vary from these assumptions. For walls not restrained from rotation, an equivalent fluid pressure of 40 pcf should be used for design. An equivalent fluid pressure of 55 pcf should be used for design of walls restrained from rotation. Superimposed seismic lateral forces should be calculated based on a dynamic force of 9.3H pounds per lineal foot of wall, where H is the height of the wall in feet, and applied at 0.6H from the base of the wall. When computing resistance to lateral loads, a base friction coefficient of 0.35 can be used. Footings for the retaining walls t should be designed as recommended for shallow foundations. As stated above, our recommendations are based on the assumption of drained conditions. Drains that consist of a 8- inch - diameter perforated drainpipe wrapped in a geotextile filter should be installed behind all retaining structures. The pipe should be embedded in a 1/2 percent) minimum 3- foot -wide zone of drain rock and sloped have an drain AOS between the U.S. S Standard toward a suitable discharge. The geotextile should No. 70 and 100 Sieve and a water permittivity greater of 3hnches and have less than 2 percent i be uniformly graded, have a maximum particle .__ passing the U.S. Standard No. 200 Sieve (washed analysis). 11 PacificRealty- 2:043098 - GeoDesign, Inc.