DRAFT GEOTECHNICAL REPORT MORRISON BLOCKS PROJECT PORTLAND, OREGON

Transcription

1 PACRIM GEOTECHNICAL INC. DRAFT GEOTECHNICAL REPORT MORRISON BLOCKS PROJECT PORTLAND, OREGON Project No August 24, 2005 geotechnical engineering and applied earth sciences

2 August 24, 2005 Project No Portland Development Commission 222 NW Fifth Avenue Portland, Oregon Attention: Subject: Mr. Robert Van Vickle GEOTECHNICAL REPORT MORRISON BLOCKS SW 1 ST AVENUE AND SW ALDER STREET PORTLAND, OREGON Dear Mr. Van Vickle: We submit herewith five copies of our geotechnical report for the Morrison Blocks Preliminary Geotechnical Engineering Study. The report was prepared for use in planning foundation systems for the proposed structure and for identifying geotechnical constraints to development of the site. The report is not a final study for use in structural design. After the building footprint is defined and anticipated loads finalized, additional explorations should be conducted to provide more accurate information on anticipated pile lengths. We appreciate the opportunity to be of service to you on this interesting project. Please call with any questions. Sincerely, PACRIM GEOTECHNICAL INC. André D. Maré, P.E., G.E. Senior Engineer

3 TABLE OF CONTENTS Page 1.0 INTRODUCTION GENERAL PROJECT DESCRIPTION AUTHORIZATION AND SCOPE OF WORK FIELD AND LABORATORY INVESTIGATIONS FIELD INVESTIGATIONS LABORATORY TESTING PREVIOUS GEOTECHNICAL STUDIES SITE CONDITIONS SURFACE CONDITIONS SUBSURFACE CONDITIONS Soil Conditions Groundwater Conditions CONCLUSIONS AND ENGINEERING RECOMMENDATIONS GENERAL FOUNDATION SUPPORT Pile Foundations Floor Slab Permanent Drainage SEISMIC CONSIDERATIONS ADDITIONAL GEOTECHNICAL STUDIES UNCERTAINTIES AND LIMITATIONS REFERENCES...10 LIST OF TABLES (WITHIN TEXT) Table 1 Preliminary Allowable Pile Capacities LIST OF FIGURES (FOLLOWING TEXT) Figure 1 Vicinity Map Figure 2 Exploration Location Plan Figure 3 Cross Section A-A Figure 4 Cross Section B-B

4 TABLE OF CONTENTS (CONTINUED) APPENDIX A: FIELD INVESTIGATIONS Figure A-1 Key to Exploration Logs Figures A-2 - A-4 Summary Logs of Borings B-1 through B-3 APPENDIX B: LABORATORY INVESTIGATIONS Figures B-1 - B-2 Grain Size Analysis Test Results Figure B-3 Plasticity Chart APPENDIX C: SUBSURFACE DATA BY OTHERS Geotechnical Resources, Inc., 1989 Hart Crowser, 1989 Moffatt, Nichol & Taylor, 1958 Dames & Moore, 1981 Parsons Brinckerhoff and FEI, 2000 ii PACRIM GEOTECHNICAL INC.

5 GEOTECHNICAL REPORT MORRISON BLOCKS SW 1 ST AVENUE AND SW ALDER STREET PORTLAND, OREGON 1.0 INTRODUCTION 1.1 GENERAL This report presents the results of a geotechnical engineering study by PacRim Geotechnical Inc. (PacRim) to support proposed site redevelopment, a 27-story building and associated at-grade parking at the west end of the Morrison Bridge in downtown Portland, Oregon. The project location is illustrated on Figure 1. This preliminary geotechnical study is part of the Portland Development Commission (PDC) due diligence in preparing for the purchase of the blocks from Multnomah County. The purpose of this study was to review available existing subsurface information, conduct field explorations and laboratory testing to evaluate subsurface conditions at the site, and develop preliminary geotechnical recommendations for the project. 1.2 PROJECT DESCRIPTION The Morrison Blocks are four city blocks located along the west side of SW Naito Parkway, underneath and between the Morrison Bridge ramps. Block 16 is bound on the north by SW Washington Street, on the east side by SW 1 st Avenue, on the south side by SW Alder Street, and on the west side by SW 2 nd Avenue. Blocks 1, 2, and 39 are bounded on the north by SW Stark Street, on the east by SW Naito Parkway, on the south side by SW Morrison Street, and on the west side by SW 1 st Avenue. The combined size of the blocks is approximately 3 acres. Currently, the site is used as a privately run parking facility. Existing site features are shown on the Exploration Location Plan, Figure 2. The proposed use of the site includes construction of a high-rise building with 27 abovegrade stories and no subgrade levels. The location of the building footprint has not yet been selected. Parking will be at-grade. 1.3 AUTHORIZATION AND SCOPE OF WORK PacRim s services were authorized by Mr. Robert Van Vickle of the Portland Development Commission via an Notice to Proceed for WO on July 5, Our scope of work included: reviewing existing subsurface information, drilling and sampling exploratory borings,

6 August 24, 2005 Project No installing a piezometer and monitoring groundwater levels, performing laboratory testing, and completing engineering analyses to develop the geotechnical conclusions and recommendations presented in this report. PacRim s scope of work did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous substances in the soil, surface water, or groundwater at this site. 2.0 FIELD AND LABORATORY INVESTIGATIONS 2.1 FIELD INVESTIGATIONS The exploration program consisted of drilling three exploratory borings (B-1 through B- 3) and installing and monitoring one piezometer in boring B-2. The borings were drilled in early August The approximate locations of the borings are shown on Figure 2. The explorations were performed under the direction of PacRim personnel, who also compiled logs of the borings and collected soil samples. Discussions of field exploration methodology and summary logs are included in Appendix A. 2.2 LABORATORY TESTING PacRim personnel conducted laboratory testing on selected soil samples to assist in the characterization of the on-site soils. Tests completed include determination of natural water content, grain-size distribution, percent fines testing, and Atterberg Limits. All laboratory tests were conducted in general accordance with appropriate American Society for Testing and Materials (ASTM) standards (ASTM, 2000). A discussion of laboratory test methodology and test results are presented in Appendix B. Test results are also displayed where appropriate on the boring logs in Appendix A. 2.3 PREVIOUS GEOTECHNICAL STUDIES We researched and reviewed available geologic and geotechnical data for the project area. In addition to reviewing published geologic mapping, we reviewed available geotechnical studies for other site development projects completed in the vicinity. Where appropriate, information from these studies was incorporated into our evaluations and analyses. Previous geotechnical information utilized for this study is included in Appendix C. Approximate locations of borings by others are shown on Figure 2. The following studies provided the most useful data: 2 PACRIM GEOTECHNICAL INC.

7 August 24, 2005 Project No ) Geotechnical Resources, Inc., Geotechnical investigation for a proposed 10-story building to the north of the Morrison Blocks site. Five borings were completed to a maximum depth of 75 feet. 2) Hart Crowser, Inc., Geotechnical investigation for a proposed 32-story building to the west of the Morrison Blocks site. Five borings were completed to a maximum depth of 40 feet, with piezometers installed in all borings. 3) Moffatt, Nichol & Taylor, Nine borings were drilled to investigate foundation conditions for the west approaches to the Morrison Bridge. Logs of 7 borings are presented on a plan sheet dated May 15, ) Dames & Moore, Geotechnical investigation for a proposed 23-story building to the southwest of the Morrison Blocks site. Four borings were completed to a maximum depth of 56 feet. 5) Foundation Engineers Inc. drilled borings in 2001 along the alignment of the West Side CSO Tunnel, on the east side of Naito Parkway. Their boring logs are presented in the data report prepared by Parsons Brinckerhoff. A piezometer was installed in one of the four borings reviewed for the current study. 3.0 SITE CONDITIONS 3.1 SURFACE CONDITIONS The site is relatively level, sloping only slightly downwards from southwest to northeast. Elevations across the site vary from about 31 to 34 feet, with the exception of SW 1 st Avenue, which separates Block 16 from Blocks 1, 2, and 39. The right-of-way carries only light-rail, and is at a lower elevation (approximately 24 feet) to allow trains to pass beneath the Morrison Bridge. Site surfacing is almost entirely asphalt pavement. The only structures are two small pay booths and the piers for the Morrison Bridge structure and ramps. 3.2 SUBSURFACE CONDITIONS PacRim s interpretations of subsurface conditions are based on the results of field explorations, review of available references, and our general experience in similar geologic settings. General geologic information for the site was obtained from the above referenced consultant studies and the Geologic Map of the Portland Quadrangle, Multnomah and Washington Counties, Oregon, and Clark County, Washington (Beeson and Tolan, 1991). The geologic mapping indicates near-surface soils consist of Quaternary Alluvium. 3 PACRIM GEOTECHNICAL INC.

8 August 24, 2005 Project No Soil Conditions Our borings revealed conditions generally consistent with the geologic mapping and other consultant studies. The site is underlain by variable fill deposits overlying alluvial silt. Beneath the silt, we encountered dense sands and gravels, which we interpreted as layers of Coarse-Grained Alluvium (or flood deposits), overlying Troutdale Formation. The information from the borings and pre-existing studies was interpolated to construct the generalized subsurface profiles shown on Figures 3 and 4. The actual stratigraphic contacts are the result of complex geologic processes and/or construction activities, so they may be gradational or more erratic than shown in the figures. Each of the soil units encountered in our borings is described below in order from youngest to oldest. Artificial Fill: Fill soils were encountered in all borings by PacRim and most pre-existing borings in the vicinity. Fill thickness in PacRim borings varies from 8 to 12 feet. Fill encountered was highly variable in composition and consistency. The predominant soil type appears to be gravelly sand, but in boring B-3, fill soils consisted of medium stiff silt. In most borings by PacRim and others, brick and concrete debris was encountered within the fill. Also, very loose or open zones are evidenced by high mud loss during drilling. Fine-Grained Alluvium: Directly below the fill we encountered a layer of finegrained alluvial deposits that extends down to Elevation 13 to 16 feet. This material is soft to medium stiff, stratified silt, clayey silt, sandy silt and silty sand. We expect this material to exhibit moderate to high compressibility and low shear strength. Coarse-Grained Alluvium: In each boring, the alluvial silt was underlain by a deposit of dense to very dense poorly graded to silty gravel. This unit extended to approximately Elevation -10 feet in the PacRim borings. This unit may be interpreted as Pleistocene Catastrophic Flood Deposits due to its higher density than typical recent alluvium. These deposits contain zones of open-work gravel which contain very little matrix and exhibit high permeability. Others have noted that this unit contains interbeds of sand and silty sand. Cobbles are abundant and occasional boulders can be encountered. We expect this material to exhibit low compressibility and moderate to high shear strength. Troutdale Formation: Very dense sandy gravel with silt was encountered directly underlying the Coarse-Grained Alluvium, extending to the total depth of our borings. These gravels typically have a tight matrix of silt and/or sand. Cobbles are abundant, but boulders are rare. Occasional lenses of very dense 4 PACRIM GEOTECHNICAL INC.

9 August 24, 2005 Project No sand to silty sand are encountered within this unit. We expect this material to exhibit low compressibility and high shear strength Groundwater Conditions One piezometer was installed in boring B-2 in the northeast portion of the site. Groundwater levels in the piezometer have been monitored twice, one day and two weeks following piezometer installation, as shown on the boring log. The measured summer water level in boring B-2 is approximately 28 feet below ground surface, or Elevation 3 feet. Measured groundwater levels from the referenced nearby existing studies include Elevation 11 feet (Hart Crowser), 6 feet (GRI), 9 feet (Foundation Engineering), and 7 feet (Dames & Moore). Groundwater levels are anticipated to fluctuate with the seasons and will likely be highest during the winter and spring months. 4.0 CONCLUSIONS AND ENGINEERING RECOMMENDATIONS 4.1 GENERAL Based on anticipated loading for a typical 27-story structure, and considering no basement levels, we recommend deep foundation support for the structure. In our opinion, the proposed building may be supported by driven piles or drilled shafts extending to the Troutdale Formation, approximately Elevation -10 feet. Groundwater issues are anticipated to be minimal. Cuts for pile caps will be well above the groundwater level. Some seepage is possible during the wet season, but this can be controlled with shallow sumps and pumps. Because of the presence of loose fill soils, the ground-level floor slab will have to be designed as a structural slab supported on the pile caps and grade beams. Removal and replacement of all fill soils within the building footprint is another alternative that would allow use of a conventional soil-supported slab. 4.2 FOUNDATION SUPPORT Plans for the building are entirely conceptual at this time; thus, building column loads have not been determined. In our experience, designs for buildings of this size typically result in column loads on the order of 1,000 to 5,000 kips. Because of the relatively high loads and presence of compressible soils to greater than 15 feet below ground surface, shallow foundations are not a feasible option. 5 PACRIM GEOTECHNICAL INC.

10 August 24, 2005 Project No Pile Foundations Deep foundation systems considered by PacRim include various driven and drilled pile types. Site conditions are generally amenable to any of the systems commonly used in this area including steel H-piles, steel pipe piles, drilled shafts, augercast piles, and driven precast concrete piles. Pile type selection may come down to economic considerations or contractor preference. Based on soil conditions described above, we recommend piles extend to the Troutdale Formation gravels. The average elevation of the top of Troutdale is approximately -10 feet as shown on the cross-sections, Figures 3 and 4. This will result in pile lengths on the order of 40 feet. Based on this pile length, the following approximate axial compression capacities are provided for use in preliminary planning. Table 1. Preliminary Allowable Pile Capacities Pile Type Axial Capacity, tons 14 H-Pile Pipe Precast Concrete Augercast Drilled Shaft 400 Assumed bearing elevation of -10 feet (approximate pile length of 40 feet) Assume high strength steel, 50ksi, for pipe and H piles. Preliminary capacities incorporate a factor of safety of about 2.5. To eliminate the need to consider group effects, preliminary layouts should consider piles spaced no closer than about 3 pile diameters center-to-center. If the proposed structure is supported on piles as recommended herein, total and differential settlements are anticipated to be within tolerable limits. Under the assumed loading conditions, preliminary estimates are approximately ½-inch total settlement per pile. The majority of settlements will occur during construction as loads are applied. Lateral capacity will be achieved through bending in the piles and passive resistance at the edges of the pile cap. Because vertical loads will be carried by deep foundations, frictional resistance along the base of the pile cap should not be included in calculating resistance to lateral loads. An ultimate passive earth pressure equivalent to a fluid weighing 400 pcf (pounds per cubic foot) may be assumed. The upper 2 feet of soil should be neglected unless surficial soils are protected by pavement. Lateral load analyses of piles have not been performed. Pile type selection should precede lateral analyses. In addition to soil parameters and pile stiffness parameters, the 6 PACRIM GEOTECHNICAL INC.

11 August 24, 2005 Project No lateral capacity will depend on the degree of fixity at the pile cap. It is our opinion that lateral capacity of piles is unlikely to control the selection of pile type or size. Thus, preliminary layouts can be based entirely on axial compressive capacity considerations. Similarly, axial uplift capacity is unlikely to control design, provided a pile depth of about 40 feet is assumed. Uplift capacities should be calculated following pile type selection Floor Slab Two options should be considered for floor slab support: 1) a structural slab designed to span between pile caps and grade beams, and 2) removal and replacement of fill soils across the building footprint followed by construction of a conventional slab-on-grade. If the second option is chosen, depth of removals will be on the order of 7 to 12 feet from current ground surface. Even if the first option is selected, there still may be a need for isolated soil removals if soft zones are encountered. Such removals would be limited to approximately 3 feet below grade. Material for use as backfill should consist of imported granular material containing less than 10 percent fines (portion passing the U.S. Standard No. 200 sieve). The fine-grained portion of structural fill soils should be non-plastic. Structural fill soils should be moisture conditioned to within about 3 percent of optimum moisture content, and placed in loose, horizontal lifts of equivalent thickness. Structural fill soils should be compacted to at least 95 percent maximum dry density, as determined by ASTM D 1557 (Modified Proctor). The procedure to achieve proper density of a compacted fill depends on the size and type of compacting equipment, the number of passes, thickness of the layer being compacted, and certain soil properties. In general, we recommend the following maximum loose lift thicknesses: 6 inches for hand-operated compactors such as jumping jacks and small vibratory base plate compactors; 10 inches for large smooth drum vibratory rollers, and 18 inches for excavator-mounted hoe-pacs Permanent Drainage We recommend that foundation drains be installed around the perimeter of the structure wherever the top of floor slab is below the adjacent exterior grade. Foundation drains should consist of 4-inch diameter perforated PVC pipe surrounded on all sides by permeable imported backfill material. Roof and surface drainage should not be connected to the foundation drain system. 4.3 SEISMIC CONSIDERATIONS We assume that seismic design of structures will be in accordance with Section 1615 of the 2003 International Building Code (International Code Council, 2003). Based on the soil conditions observed during the exploration program, we recommend assuming Site 7 PACRIM GEOTECHNICAL INC.

12 August 24, 2005 Project No Class D, "stiff soil profile". The mapped site spectral response accelerations are S s =0.98 and S 1 =0.34. The corresponding seismic coefficients are: F a = 1.11 and F v = The normalized response spectra for the assumed soil type are considered adequate for the site. Based on the 2002 USGS National Seismic Hazards Mapping Project, the expected peak ground acceleration for the site is 0.19g. This value is based on a 500-year return period event, which has a 10 percent probability of being exceeded in a 50-year period. Due to the relatively dense nature of saturated soils beneath the groundwater level, it is our opinion that the risk of liquefaction at the site is very low. 4.4 ADDITIONAL GEOTECHNICAL STUDIES At the time of this study, design is very conceptual and the building footprint has not been selected. During final design of the structure, additional borings will be necessary to provide more definitive information for pile depth and capacity estimates. In our opinion, an additional three borings, each extending to approximately 50 feet below grade, will be required during final design. 5.0 UNCERTAINTIES AND LIMITATIONS We have prepared this report for use by the project design team and owner for use in preliminary planning. Experience has shown that subsurface soil and groundwater conditions can vary significantly over small distances. While the actual conditions encountered in the field are expected to be within the ranges discussed herein, the distribution of geologic conditions encountered will likely vary from those presented in this report. This report is preliminary and is intended for use as an early planning document. Prior to construction, further studies should be implemented to verify and refine our preliminary findings and conclusions. Recommendations for further study are presented in Section 4.4 of this report. Within the limitations of scope, schedule and budget, PacRim attempted to execute these services in accordance with generally accepted professional principles and practices in the fields of geotechnical engineering and engineering geology at the time the report was prepared. No warranty, expressed or implied, is made. 8 PACRIM GEOTECHNICAL INC.

13 August 24, 2005 Project No We appreciate the opportunity to be of service. PACRIM GEOTECHNICAL INC. André D. Maré, P.E., G.E. Senior Geotechnical Engineer 9 PACRIM GEOTECHNICAL INC.

14 August 24, 2005 Project No REFERENCES American Society for Testing and Materials, 2000, Annual Book of ASTM Standards, Vol. 4.08, Soil and Rock (1): D420-D4914, Philadelphia: ASTM. Beeson, M.H. and Tolan, T.L., 1991, Geologic Map of the Portland Quadrangle, Multnomah and Washington Counties, Oregon, and Clark County, Washington, Oregon Department of Geology and Mineral Industries GMS-75, Scale 1:24,000. Dames & Moore, 1981, Foundation Investigation, Proposed High Rise Structure, SW First and Second Avenues and Alder and Morrison Streets, Portland, Oregon, Consultant report to T.L. Brandt Company, dated August 31, Geotechnical Resources, Inc., 1989, Geotechnical Investigation for One Oak Plaza, GSA Building, Portland, Oregon, Consultant Report to Melvin Mark Properties, dated November 30, Hart Crowser, 1989, Geotechnical Engineering Design Study, Morrison Street Development, Portland, Oregon, Consultant report to Wright Runstad and Company, dated June 7, International Code Council, 2003, 2003 International Building Code. Mabey, M.A., Madin, I.P., Youd, T.L., and Jones, C.F., 1993, Earthquake Hazard Maps of the Portland Metropolitan Quadrangle, Multnomah and Washington Counties, Oregon, and Clark County, Washington, GMS-79, State of Oregon Department of Geology and Mineral Industries. Madin, I.P., 1990, Earthquake-Hazard Geology Maps of the Portland Metropolitan Area, Oregon, Oregon Department of Geology and Mineral Industries OFR O Moffat, Nichol & Taylor, 1958, Morrison Bridge, West Approaches, Test Borings 16 thru 24 and Plan, dated May 15, Parsons Brinckerhoff, 2001, West Side CSO Project, Geotechnical Data Report, November 29, 2001, boring logs dated November 2000 by Foundation Engineering, Inc. under subcontract to Parsons Brinckerhoff. U.S. Geological Survey, 2002, National Seismic Hazards Mapping Project, "Peak Acceleration with 10% Probability of Exceedance in 50 Years", October PACRIM GEOTECHNICAL INC.

15 SITE ``` SOURCE: Printed from Thomas Bros. Map 1999 N Not to Scale Morrison Blocks SW 1st Ave & Alder St Portland, Oregon GEOTECHNICAL ENGINEERING AND APPLIED EARTH SCIENCES Project No.: Vicinity Map Figure 1

16 T SW 1 SW NAIT OPKY SW 5T H AVE SW 3RD AV B-4 B-2 B-1 SW WASHINGT WASHINGT WASHINGT WASHINGT WASHINGT WASHINGT WASHINGT WASHINGT WASHINGT ON ST B-5 SW Stark Street B-3 ER ST MORRISON MORRISON MORRISON MORRISON MORRISON MORRISON MORRISON MORRISON MORRISON BRG-NAIT BRG-NAIT BRG-NAIT BRG-NAIT BRG-NAIT BRG-NAIT BRG-NAIT BRG-NAIT BRG-NAIT ORAMP ORAMP ORAMP ORAMP ORAMP ORAMP ORAMP ORAMP ORAMP NB N BIKEPAT H MORRISON RAMP B-1 B-22 B-1 B-2 B-20 SW 3rd Avenue SW 2nd Avenue SW Washington Street Legend B-1 PacRim Boring Location MORRISON MORRISON MORRISON MORRISON MORRISON MORRISON MORRISON MORRISON MORRISON BRG HC-2 HC-5 HC-1 HC-4 HC-3 B-2 Dames & Moore, August 1981 Hart Crowser, June 1989 GRI, November 1989 Parsons Brinckerhoff, November 2000 Moffatt, Nichol & Taylor, May 1958 Area of Interest (Blocks 16, 1, 2, & 39) SW YAMHILL YAMHILL YAMHILL YAMHILL YAMHILL YAMHILL YAMHILL YAMHILL YAMHILL ST NAIT NAIT NAIT NAIT NAIT NAIT NAIT NAIT NAIT O-MORRISON O-MORRISON O-MORRISON O-MORRISON O-MORRISON O-MORRISON O-MORRISON O-MORRISON O-MORRISON BRGRAMP BRGRAMP BRGRAMP BRGRAMP BRGRAMP BRGRAMP BRGRAMP BRGRAMP BRGRAMP SB SB SB SB SB SB SB SB SB B-4 B-3 B-3 PB-301A PB-922C PB-923 PB-302A B-19 SW Naito Parkway SW 1st Avenue B-21 B-18 B-1 B-16 HC-1 B-17 B-1 PB-1 B-1 SW Morrison Street SW Yamhill Street T GEOTECHNICAL ENGINEERING AND APPLIED EARTH SCIENCES Horizontal Scale in feet Morrison Blocks EXPLORATION LOCATION PLAN SW 1st Ave and Alder St Portland, Oregon Project No.: Figure 2

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19 APPENDIX A FIELD EXPLORATION PROGRAM

20 APPENDIX A FIELD EXPLORATION PROGRAM Subsurface exploration consisted of drilling of three exploratory borings (B-1 through B-3). The exploration program was completed between August 4 and August 6, The borings were each advanced to a depth of 60 feet below ground surface. Explorations were located in the field by pacing and taping distances from existing site features and are plotted on Figure 2. Summary exploration logs are included in this appendix as Figures A-2 through A-4. A key to the symbols and terms used on the summary logs is presented as Figure A-1. A PacRim representative was present throughout the field exploration program to observe the explorations, assist in sampling, and to prepare descriptive logs of the explorations. Soils were classified in general accordance with ASTM D-2488 Standard Practice for Description and identification of Soils (Visual-Manual Procedure) (ASTM, 2000). The summary exploration logs in this appendix represent our interpretation of the contents of the field logs and the results of laboratory testing. The stratigraphic contacts shown on the individual summary logs represent the approximate boundaries between soil types; actual transitions may be more gradual. The subsurface conditions depicted are only for the specific dates and locations reported, and therefore, are not necessarily representative of other locations and times. The borings were drilled by Boart Longyear Corportation of Tualatin, Oregon under subcontract to PacRim. Borings were drilled using mud rotary techniques from a truck-mounted Mobile B-57 drill rig. The sample drive hammer was equipped with an automatic trip mechanism for controlling the stroke distance during performance of Standard Penetration Tests (SPT). Soil samples were obtained from the borings at 2½ to 5-foot depth intervals. Representative portions of the samples were collected and transported to our laboratory for further observation and testing. SPT sampling was performed in general accordance with ASTM D 1586 using a 2-inch O.D. split spoon sampler and a 140-pound hammer. During the test, a sample is obtained by driving the sampler 18 inches into the soil with the hammer free-falling 30 inches. Recorded blows for each 6 inches of sampler penetration are shown on the boring logs. SPT blow counts for the final 12 inches are referred to as N-values and provide a qualitative measure of the relative density of cohesionless soil, or the relative consistency of fine-grained soils. An open-standpipe piezometer was installed in boring B-2. The piezometer consists of a 2-inch diameter PVC pipe with a 10-foot machine-slotted screened section supplied by the drilling contractor. The annular space around the piezometer was backfilled with filter media to a point 4 feet above the screened section. Bentonite and cement seals and a locking well cover were installed. Graphical representation of piezometer construction is shown on the boring log. The piezometer should be removed during construction; this work should be included in the contract documents. Groundwater levels measured in the piezometer are shown on the boring log.

21 RELATIVE DENSITY OR CONSISTENCY VERSUS SPT N-VALUE Density Very Loose Loose Medium Dense Dense Very Dense Coarse Grained Soils More than 50% Retained on No. 200 Sieve Size Fine Grained Soils 50% or More Passing No. 200 Sieve Size COHESIONLESS SOILS Approximate Approximate AL N (blows/ft) Consistency N (blows/ft) Undrained Shear Relative Density (%) Strength (psf) FC 0 to Very Soft 0 to 2 <250 GSD to MC 4 to Soft MD 10 to Medium Stiff 4 to Comp 30 to Stiff to over Very Stiff 15 to SG Hard over 30 >4000 CBR RM Perm UNIFIED SOIL CLASSIFICATION SYSTEM TXP MAJOR DIVISIONS GROUP DESCRIPTIONS Cons VS Gravel and Well-graded GRAVEL DS Clean Gravel GW Gravelly Soils UC (little or no fines) GP Poorly-graded GRAVEL TXS More than HYD 50% of Coarse Gravel with GM Silty GRAVEL UU Fraction Retained Fines (appreciable CU on No. 4 Sieve amount of fines) GC Clayey GRAVEL CD Sand and Sandy Soils 50% or More of Coarse Fraction Passing No. 4 Sieve Silt and Clay Silt and Clay Clean Sand (little or no fines) Sand with Fines (appreciable amount of fines) Liquid Limit Less than 50% Liquid Limit 50% or More COHESIVE SOILS SW SP SM SC ML CL OL MH CH OH Well-graded SAND Poorly-graded SAND Silty SAND Clayey SAND SILT Lean CLAY Organic SILTor CLAY Elastic SILT Fat CLAY Organic SILTor CLAY LABORATORY TEST SYMBOLS Atterberg Limits Fines Content Grain Size Distribution Moisture Content Moisture Content/Dry Density Compaction Test (Proctor) Specific Gravity California Bearing Ratio Resilient Modulus Permeability Triaxial Permeability Consolidation Vane Shear Direct Shear Unconfined Compression Triaxial Compression Hydrometer Unconsolidated, Undrained Consolidated, Undrained Consolidated, Drained SAMPLE TYPE SYMBOLS Std. Penetration Test (2.0" OD) Ring Sampler (3.25" OD) California Sampler (3.0" OD) Undisturbed Tube Sample Grab Sample Core Run RQD = A measure of the percentage of rock core recovered in pieces with lengths of 4 inches or greater, discounting drillers breaks. Highly Organic Soils PT PEAT DESCRIPTORS FOR SOIL STRATA AND STRUCTURE GROUNDWATER WELL COMPLETIONS PACRIM EXPLORATION LEGEND GPJ PACRIM.GDT 8/26/05 General Thickness or Spacing Notes: Parting: less than 1/16 in. Seam: 1/16 to 1/2 in. Layer: 1/2 to 12 in. Stratum: greater than 12 in. Scattered: less than 1 per ft. Numerous: more than 1 per ft. Structure Pocket: Lens: Varved: Laminated: Interbedded: Erratic, discontinuous deposit of limited extent Lenticular deposit Alternating seams of silt and clay Alternating seams Alternating layers 1. Sample descriptions in this report are based on visual field and laboratory observations, which include density/consistency, moisture condition, grain size, and plasticity estimates, and should not be construed to imply field nor laboratory testing unless presented herein. Visual-manual classification methods of ASTM D 2488 were used as an identification guide. Where laboratory data are available, soil classifications are in general accordance with ASTM D Solid lines between soil unit descriptions indicate change in interpreted geologic unit. Dashed lines indicate stratigraphic change within the unit. General Attitude Near horizontal: 0 to 10 deg. Low angle: 10 to 45 deg. High angle: 45 to 80 deg. Near vertical: 80 to 90 deg. Project No Concrete Seal Well Casing Bentonite Seal Groundwater Level and Date (ATD = At Time of Drilling) Slotted Well Casing Sand Backfill Soil Cuttings / Slough Morrison Blocks Portland, Oregon Portland Development Commission KEY TO EXPLORATION LOGS FIGURE A-1

22 Other Tests Sample No. Dry Density (pcf) Moisture Content (%) Blows/6 inches Sample Depth (feet) USCS Graphic Symbol DESCRIPTION Elevation (feet) Groundwater Well Detail S-1 S /0" 5 SP GP PAVEMENT, 3" asphalt over 6" gravel base. Poorly Graded SAND, loose to medium dense, moist, fine to medium-grained. (FILL) Poorly Graded GRAVEL, loose to medium dense, moist, fine to coarse-grained. Concrete slab from appoximately 5' to 6.5' over void or very soft zone to 7.8'. 30 FC %F=94 AL, FC %F=94 S-3 S At 7 feet, drilling mud loss. Stratified SILT, Clayey SILT, and Sandy SILT, medium stiff, slightly mottled/oxidized brown, moist to wet, low to medium plasticity. Sand is fine-grained, micaceous. (FINE-GRAINED ALLUVIUM) ML GSD %F=96 S S Poorly Graded GRAVEL to Poorly Graded GRAVEL with Sand, very dense grading dense by 30 feet, moist to wet, brown, non-plastic matrix. Fine to coarse, rounded to angular/broken gravel. Sand is predominantly coarse-grained, micaceous, relatively open. (COARSE-GRAINED ALLUVIUM) 10 S S GP 0 BORING_WELL SPT GPJ PACRIM.GDT 8/26/05 17 S Surface Elevation: 32 feet Date Completed: 8/6/05 Logged By: GCS Equipment: Mobile B-57 Drilling Method: Mud Rotary Hammer System: Auto-hammer 35 Morrison Blocks Portland, Oregon Portland Development Commission SHEET 1 OF 2 Project No FIGURE A-2-5 LOG OF BORING B-1

23 Other Tests Sample No. Dry Density (pcf) Moisture Content (%) Blows/6 inches Sample Depth (feet) USCS Graphic Symbol DESCRIPTION Elevation (feet) Groundwater Well Detail S-10 S /3" 45 GP Poorly Graded GRAVEL, dense, wet, brown. Poorly Graded GRAVEL with Sand and Silt, very dense, very moist to wet, brown. Fine to coarse gravel, relatively tight matrix. (TROUTDALE FORMATION) S-12 50/3" 50 GP GM -20 S-13 50/5" S-14 50/4" 60 SP Poorly Graded SAND, very dense, moist, brown, fine to medium-grained with some fine rounded gravel. Total Depth = 60.8 feet BORING_WELL SPT GPJ PACRIM.GDT 8/26/05 Date Completed: 8/6/05 Logged By: GCS Equipment: Mobile B-57 Drilling Method: Mud Rotary Hammer System: Auto-hammer Morrison Blocks Portland, Oregon -45 Portland Development Commission LOG OF BORING B-1 SHEET 2 OF 2 Project No FIGURE A-2

24 Other Tests Sample No. Dry Density (pcf) Moisture Content (%) Blows/6 inches Sample Depth (feet) USCS Graphic Symbol DESCRIPTION Elevation (feet) Groundwater Well Detail S SP PAVEMENT, 2"-3" asphalt over 6" gravel base. Poorly Graded SAND, Very loose to medium dense, moist, fine to medium grained. Some gravel and brick fragments above 2.5 feet. (FILL) 30 S At 7 feet, drilling mud loss. 25 S GP Poorly Graded GRAVEL, Loose to dense, moist, fine to coarse grained. At 9 feet, drilling mud loss. S /5.5" 10 SILT to Sandy SILT, Soft, brown, moist, stratified, low plasticity. Some mica. 20 (FINE-GRAINED ALLUVIUM) FC %F=97 S ML 15 S Poorly Graded GRAVEL with Silt and Sand, very dense, wet, brown, fine to coarse grained. Non-plastic matrix, staining/weathering discoloration in places. (COARSE-GRAINED ALLUVIUM) 10 GSD %F=9 S S /5.5" 30 GP GM 0 S BORING_WELL SPT GPJ PACRIM.GDT 8/26/05 Surface Elevation: 31 feet Date Completed: 8/5/05 Logged By: GCS Equipment: Mobile B-57 Drilling Method: Mud Rotary Hammer System: Auto-hammer Morrison Blocks Portland, Oregon Portland Development Commission LOG OF BORING B-2 SHEET 1 OF 2 Project No FIGURE A-3

25 Other Tests Sample No. Dry Density (pcf) Moisture Content (%) Blows/6 inches Sample Depth (feet) USCS Graphic Symbol DESCRIPTION Elevation (feet) Groundwater Well Detail S GP Poorly Graded GRAVEL, very dense, wet, brown, fine to coarse grained. Non-plastic matrix, staining/weathering discoloration in places. -10 S /5" 45 SP SM Stratified Poorly Graded SAND, Silty SAND, and SILT, very dense, moist, brown, non-plastic. Sand is fine- to medium-grained, micaceous. (TROUTDALE FORMATION) -15 S-12 50/3.5" 50 GP GM Poorly Graded GRAVEL with Sand and Silt, very dense, moist to wet, brown, fine to coarse grained. Non-plastic matrix, sand is fine to coarse-grained, micaceous. Poor recovery, depth of contact with underlying material uncertain. -20 S Poorly Graded SAND with Silt and Gravel, very dense, moist, brown. Fine to medium-grained sand and fine rounded gravel. 1" layer of brittle SILTSTONE at approximately 56 feet -25 SP SM S-14 50/5" 60 Total Depth = 60.4 feet. -30 Groundwater Measurements: 8/06/05: 28.3 feet 8/17/05: 28.5 feet BORING_WELL SPT GPJ PACRIM.GDT 8/26/05 Date Completed: 8/5/05 Logged By: GCS Equipment: Mobile B-57 Drilling Method: Mud Rotary Hammer System: Auto-hammer Morrison Blocks Portland, Oregon Portland Development Commission LOG OF BORING B-2 SHEET 2 OF 2 Project No FIGURE A-3

26 Other Tests Sample No. Dry Density (pcf) Moisture Content (%) Blows/6 inches Sample Depth (feet) USCS Graphic Symbol DESCRIPTION Elevation (feet) Groundwater Well Detail S PAVEMENT, 3"-4" asphalt over 4"-5" gravel base. Stratified Clayey SILT and Sandy SILT, medium stiff to stiff, moist, mottled brown, low to medium plasticity. Some gravel in upper 4 feet. (FILL) 30 FC %F=91 S ML 25 S FC %F=99 S S ML SM Stratified Clayey SILT to Silty SAND, medium stiff/loose, slightly mottled/oxidized brown, moist, low plasticity to non-plastic. Sand is fine-grained, micaceous. (FINE-GRAINED ALLUVIUM) Poorly Graded GRAVEL to Poorly Graded GRAVEL with Sand, dense to very dense, moist to wet, brown, fine to coarse grained. Sand is fine to coarse-grained, micaceous, relatively open. Staining/weathering discoloration in places. 15 S /5" 20 (COARSE-GRAINED ALLUVIUM) 10 S GP S /5.5" 30 0 S BORING_WELL SPT GPJ PACRIM.GDT 8/26/05 Surface Elevation: 31 feet Date Completed: 8/4/05 Logged By: GCS Equipment: Mobile B-57 Drilling Method: Mud Rotary Hammer System: Auto-hammer Morrison Blocks Portland, Oregon Portland Development Commission LOG OF BORING B-3 SHEET 1 OF 2 Project No FIGURE A-4

27 Other Tests Sample No. Dry Density (pcf) Moisture Content (%) Blows/6 inches Sample Depth (feet) USCS Graphic Symbol DESCRIPTION Elevation (feet) Groundwater Well Detail S /6" Poorly Graded GRAVEL with Sand and Silt, very dense, wet, yellowish brown. Fine to coarse, rounded to angular gravel. -10 (TROUTDALE FORMATION) S-11 50/4" Possible sand interbed 47 to 49 feet. S-12 50/4" 50 GP GM -20 S /3.5" S-14 50/3" 60 Total Depth = 60.2 feet BORING_WELL SPT GPJ PACRIM.GDT 8/26/05 Date Completed: 8/4/05 Logged By: GCS Equipment: Mobile B-57 Drilling Method: Mud Rotary Hammer System: Auto-hammer Morrison Blocks Portland, Oregon Portland Development Commission LOG OF BORING B-3 SHEET 2 OF 2 Project No FIGURE A-4

28 APPENDIX B LABORATORY TESTING

29 APPENDIX B LABORATORY TESTING PacRim Geotechnical Inc. personnel performed laboratory tests on soil samples collected from the explorations. Laboratory tests included determination of: Natural Moisture Content, Grain Size Distribution, Percent Fines, and Atterberg Limits. All laboratory tests were conducted in general accordance with appropriate ASTM test methods (ASTM, 2000). The test procedures and test results are discussed below. MOISTURE CONTENT Laboratory tests were conducted to determine the natural moisture content of selected soil samples in general accordance with ASTM D Test results are indicated at the sampled intervals on the appropriate summary logs in Appendix A. GRAIN SIZE DISTRIBUTION Grain size distribution was determined for selected samples in general accordance with ASTM D-422, Standard Test Method for Particle-Size Analysis of Soils. Results of grain size analyses are plotted on Figures B-1 and B-2. FINES CONTENT Fines content testing was performed on selected samples in accordance with ASTM D The test results are included with the grain size distribution results on Figures B-1 and B-2. ATTERBERG LIMITS The Liquid Limit (LL), Plastic Limit (PL), and Plasticity Index (PI) were determined for a selected sample in accordance with ASTM D The test results are plotted on Figure B-3.

30 Coarse GRAVEL Fine Coarse Medium SAND Fine SILT CLAY 100 3" 1-1/2" 3/4" 5/8" U.S. STANDARD SIEVE SIZES 3/8" #4 #10 #20 #40 #60 #100 # PERCENT FINER BY WEIGHT GRAIN SIZE IN MILLIMETERS SYMBOL SAMPLE DEPTH (ft) CLASSIFICATION % MC LL PL PI % Gravel % Sand % Fines B-1 S SILT (ML) B-1 S SILT (ML) B-1 S SILT (ML) B-2 S SILT (ML) Morrison Blocks Portland, Oregon Portland Development Commission GRAIN SIZE ANALYSIS TEST RESULTS Project No FIGURE B-1

31 Coarse GRAVEL Fine Coarse Medium SAND Fine SILT CLAY 100 3" 1-1/2" 3/4" 5/8" U.S. STANDARD SIEVE SIZES 3/8" #4 #10 #20 #40 #60 #100 # PERCENT FINER BY WEIGHT GRAIN SIZE IN MILLIMETERS SYMBOL SAMPLE DEPTH (ft) CLASSIFICATION % MC LL PL PI % Gravel % Sand % Fines B-2 S POORLY GRADED GRAVEL WITH SILT AND SAND (GP) B-3 S SILT (ML) B-3 S SILT (ML) Morrison Blocks Portland, Oregon Portland Development Commission GRAIN SIZE ANALYSIS TEST RESULTS Project No FIGURE B-2

32 60 CL CH 50 PLASTICITY INDEX (PI) CL-ML ML&OL MH&OH LIQUID LIMIT (LL) SYMBOL SAMPLE DEPTH (ft) CLASSIFICATION % MC LL PL PI % Fines B-1 S SILT (ML) Morrison Blocks Portland, Oregon Portland Development Commission ATTERBERG LIMITS TEST RESULTS Project No FIGURE B-3

33 APPENDIX C SUBSURFACE DATA BY OTHERS

34 Boring Logs Geotechnical Investigation for One Oak Plaza Building GRI, November, 1989 Boring Pages B-1 2 B-2 1 B-3 2 B-4 2 B-5 2

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44 Boring Logs Geotechnical Investigation for Morrison Street Project Hart Crowser, June, 1989 Boring Pages HC-1 1 HC-2 1 HC-3 1 HC-4 1 HC-5 1

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50 Test Borings 16 Thru 24 and Plan Morrison Bridge, West Approaches Moffatt, Nichol & Taylor, May, 1958

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52 Boring Logs Geotechnical Investigation for Proposed High-Rise Structure SW First and Second Avenues and Alder and Morrison Streets Dames & Moore, August, 1981 Boring Pages B-1 & B-2 1 B-3 & B-4 1

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55 Boring Logs Geotechnical Investigation for West Side CSO Tunnel Project Foundation Engineering, Inc. and Parsons Brinckerhoff November, 2000 Boring Pages PB-301A 2 PB-302A 2 PB-922C 2 PB-923 3

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