Ivy St Pedestrian Improvements Geotech Report.pdf

REPORT OF GEOTECHNICAL ENGINEERING SERVICES

South Ivy Street Pedestrian Intersection Improvements South Ivy Street Clackamas County, Oregon

For Kittelson & Associates, Inc.

February 14, 2020

GeoDesign Project: ClackCo-105-01

9450 SW Commerce Circle, Suite 300 l Wilsonville, OR 97070 l 503.968.8787 www.geodesigninc.com

February 14, 2020

Kittelson & Associates, Inc.

851 SW 6th Avenue, Suite 600 Portland, OR 97204

Attention: Tony Roos, P.E.

Report of Geotechnical Engineering Services South Ivy Street Pedestrian Intersection Improvements

South Ivy Street Clackamas County, Oregon

GeoDesign Project: ClackCo-105-01

GeoDesign, Inc. is pleased to submit this report of geotechnical engineering services for the proposed improvements associated with South Ivy Street between OR 99E and Lee Elementary School in Clackamas County, Oregon. This report provides geotechnical design recommendations and construction guidelines for the proposed improvements.

We appreciate the opportunity to be of service to both Kittelson & Associates, Inc. and Clackamas County. Please call if you have questions regarding this report.

Sincerely, GeoDesign, Inc.

Krey D. Younger, P.E., G.E. George Saunders, P.E., G.E.

Senior Associate Engineer Principal Engineer cc: Cedomir Jesic, Cardno (via email only)

JLM:KDY:GPS:kt

Attachments

One copy submitted (via email only)

Document ID: ClackCo-105-01-021420-geor.docx

© 2020 GeoDesign, Inc. All rights reserved.

i ClackCo-105-01:021420

EXECUTIVE SUMMARY

Based on our review of the proposed preliminary development plan and the results of our explorations, laboratory testing, field testing, and analysis, it is our opinion that the proposed improvements can be constructed at the site. The main report should be referenced for a detailed description of the subsurface conditions and a full understanding of our geotechnical recommendations. A summary of the primary geotechnical considerations for the project is provided below.

We measured highly variable infiltration rates in the underlying gravel in the exploration locations. Accordingly, we recommend all locations of future on-site stormwater disposal systems be tested during construction to confirm the design rate is appropriate.

Cobbles and boulders are present in the underlying gravel. Excavations in oversize material will be difficult and may require larger equipment or possibly special rock excavation methods. Removal of oversize material will result in caving, excavations larger than anticipated, and increased backfill volumes.

ClackCo-105-01:021420

TABLE OF CONTENTS PAGE NO.

ACRONYMS AND ABBREVIATIONS

1.0 INTRODUCTION 1

2.0 PROJECT UNDERSTANDING 1

3.0 SCOPE OF SERVICES 1

4.0 SITE CONDITIONS 2

4.1 Geologic Setting 2

4.2 Surface Conditions 3

4.3 Subsurface Conditions 3

5.0 INFILTRATION TESTING 4

5.1 Infiltration Testing in Borings 4

5.2 Infiltration Testing in Drywells A-52 and A-59 5

5.3 Stormwater Disposal Design 5

6.0 SIGNAL POLE FOUNDATION DESIGN 6

7.0 CONSTRUCTION CONSIDERATIONS 7

7.1 Site Preparation 7

7.2 Wet Weather Considerations 7

7.3 Excavation 8

7.4 Materials 9

7.5 Erosion Control 10

9.0 OBSERVATION OF CONSTRUCTION 10

9.0 LIMITATIONS 11

REFERENCES 13

FIGURES

Vicinity Map Figure 1 Site Plan Figure 2

APPENDICES

Appendix A Field Exploration A-1 Laboratory Testing A-1 Exploration Key Table A-1 Soil Classification System Table A-2 Boring Logs Figures A-1 – A-4 Summary of Laboratory Data Figure A-5 SPT Hammer Calibrations Appendix B Groundwater Map B-1 Map

ClackCo-105-01:021420

ACRONYMS AND ABBREVIATIONS

AASHTO American Association of State Highway and Transportation Officials AC asphalt concrete ASTM American Society for Testing and Materials BGS below ground surface GPS global positioning system H:V horizontal to vertical ODOT Oregon Department of Transportation OSHA Occupational Safety and Health Administration OSSC Oregon Standard Specifications for Construction (2018) PCC portland cement concrete pcf pounds per cubic foot pci pounds per cubic inch psf pounds per square foot SPT standard penetration test UIC underground injection control

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1.0 INTRODUCTION

This report presents the results of GeoDesign’s geotechnical engineering evaluation for the proposed improvements associated with South Ivy Street in Clackamas County, Oregon. Figure 1 shows the site relative to existing topographic and physical features. Existing conditions and the exploration locations are shown on Figure 2. Acronyms and abbreviations used herein are defined above, immediately following the Table of Contents.

2.0 PROJECT UNDERSTANDING

We understand that the City of Canby plans to provide new bicycle lanes and sidewalk improvements on South Ivy Street between Pacific Highway E (OR 99E) and Lee Elementary School in Clackamas County, Oregon. As part of the project, new signal pole construction at the intersection of South Ivy Street and SE Township Road is being considered. At the request of the City of Canby, Clackamas County is managing the improvement project through its certification agreement with ODOT.

Part of the project includes modifying the existing cross section of South Ivy Street to include new bicycle lanes and sidewalks, which will require new stormwater collection and conveyance systems. Based on discussion with Cardno, we understand that stormwater will be routed to existing and new UIC drywell systems.

We understand the new signal pole construction may include installation of three mast-arm signal poles at the intersection of South Ivy Street and SE Township Road. The new signal poles will be designed and constructed in accordance with the applicable ODOT standards.

3.0 SCOPE OF SERVICES

The purpose of our geotechnical engineering services was to characterize site subsurface conditions and provide geotechnical engineering recommendations for use in design and construction of the proposed improvements. Our scope of services included the following:

Reviewed available information from previous geological and geotechnical studies conducted in the vicinity of the project.

Obtained one-call utility locates for explorations and obtained necessary permits through

Clackamas County.

Provided traffic control during field explorations through our subcontractor.

Explored subsurface conditions along the project alignment by completing the following:

Two borings were completed to depths of between 14 and 16.5 feet BGS using hollow-stem auger techniques. Both borings were used to facilitate infiltration testing.

One boring was completed to a depth of 31.5 feet BGS using both hollow-stem auger and mud rotary drilling techniques. Hollow-stem augers were used to drill the upper 10 feet of the boring to facilitate infiltration testing. Mud rotary drilling techniques were used to complete the exploration.

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One boring was completed to a depth of 31.5 feet BGS using mud rotary drilling techniques.

Collected soil samples at 2.5- and 5-foot intervals from the explorations for soil classification and laboratory testing.

Performed infiltration tests between depths of 10 and 15 feet BGS in three of the borings.

Measured the infiltration capacity of existing drywells A-52 and A-59, west of South Ivy

Street, using a water level logger and varying flow rates fed from a hydrant connected to the City of Canby water system.

Conducted the following laboratory tests on soil samples collected from the explorations:

Sixteen moisture content determinations in general accordance with ASTM D2216 Six particle-size analyses for material passing the U.S. Standard No. 200 sieve in general accordance with ASTM C117 Provided the results of our infiltration testing.

Provided soil parameters to be used for signal pole foundation design.

Provided construction recommendations for site preparation, structural fill compaction criteria, and wet/dry weather earthwork procedures.

Provided this draft geotechnical report summarizing the results of our subsurface investigation and recommendations.

4.0 SITE CONDITIONS

4.1 GEOLOGIC SETTING

The site is located within the Willamette Valley physiographic province (Orr and Orr, 1999). Bedrock in this region consists of basalt flows emplaced approximately 15 million years ago as part of the Columbia River Basalt Group (Gannett and Caldwell, 1998; Burns et al., 1997).

During and after the Miocene Age, uplift and rotation of the Coast Range to the east created a number of closed basins within the Willamette Valley, which filled with silt, sand, and gravel of Miocene to Pleistocene Age (14.5 million to 1 million years old) (Orr and Orr, 1999). These deposits form the majority of basin fill sediments in the Willamette Valley. This sedimentary package is generally mapped as the Sandy River Mudstone toward the lower portion of the assemblage (mostly fine-grained sandstone and mudstone) overlain by the Troutdale Formation, a series of gravel, sand, and silt, with both units deposited by the ancestral Columbia River and smaller rivers running out of the Cascade Mountains (Tolan and Beeson, 1984; Evarts et al., 2013).

The basin fill sediments are overlain by late Pleistocene Age catastrophic flood deposits.

Approximately 15,000 to 12,000 years ago floods caused by the sudden drainage of large glacial lakes in western Montana swept down the Columbia River and over the lowlands of the Portland area (Allen et al., 1986), leaving behind thick accumulations of silt, sand, and gravel. These Missoula flood deposits can be divided into a fine-grained facies consisting of silt and fine sand and a coarse-grained facies with gravel- to boulder-sized material deposited in a matrix of sand and silt. In Canby, a thick (110 to 130 feet) delta of gravel and boulders was deposited as a result of the Missoula Floods being channeled through the topographic gap along the Columbia River at Oregon City. These deposits are generally overlain by 10 to 30 feet of silt and sand in

3 ClackCo-105-01:021420 the project area (O’Connor et al., 2001; Burns and Coe, 2012). The total thickness of the basin fill and flood deposits in the vicinity of the site is thought to be approximately 600 to 700 feet (Gannett and Caldwell, 1998; Burns et al., 1997).

4.2 SURFACE CONDITIONS

South Ivy Street is an AC-surfaced major collector with intermittent sidewalks, curbs, and bike lanes. Mixed residential and commercial developments are situated adjacent to the project alignment. The proposed improvement zone of South Ivy Street is generally oriented in a northwest/southeast direction with generally two lanes; however, a center turn lane is present between OR 99E and SE 6th Place. Vegetation along the roadway consists of grass, shrubs, and trees.

4.3 SUBSURFACE CONDITIONS

4.3.1 General

Our subsurface exploration program consisted of drilling four borings (C-1 through C-4) to depths of between 14 and 31.5 feet BGS. The approximate locations of the explorations are shown on Figure 2. A description of our exploration and laboratory testing programs, logs of the explorations, and results of laboratory testing are presented in Appendix A.

Subsurface conditions generally consist of fill, sandy clay, and sand with vary proportions of silt and gravel over a dense gravel unit. The following sections provide a detailed description of the units encountered.

4.3.2 Pavement

AC was encountered at the ground surface in all borings completed for this study. Below the AC we encountered either PCC pavement slab or aggregate base in each boring location. Table 1 presents the thicknesses of AC, PCC, and aggregate base encountered at the boring locations.

Table 1. Existing Pavement Thickness

Boring Number

Lane Thickness of AC

(inches)

Thickness of PCC (inches)

Thickness of Aggregate Base

(inches)

C-1 Center 3.0 10.0 Not encountered C-2 Center 4.0 6.0 Not encountered C-3 Center 8.0 Not encountered 4.0 C-4 Center 8.0 Not encountered 6.0

4.3.3 Fill

We encountered fill beneath the pavement sections to depths up to 4.5 feet BGS in borings C-1 and C-2. The fill consists of silt with minor gravel, sand, and clay and clayey sand with trace silt in borings C-1 and C-2, respectively. Based on SPT blow counts, the silt and clayey sand fill are very soft to soft and very loose, respectively. Our laboratory testing program indicates the moisture content of the fill varied from 21 to 27 percent at the time of our explorations.

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4.3.4 Sandy Clay

We encountered sandy clay in boring C-3 beneath the pavement section to a depth of approximately 4.5 feet BGS. A sample of the clay appeared to demonstrate medium plasticity.

Based on SPT blow counts, the sandy clay is soft to medium stiff. Based on laboratory testing, a sample of the clay had a moisture content of 21 percent at the time of our explorations.

4.3.5 Sand

We encountered sand with varying proportions of silt and gravel in borings C-2 and C-3 beneath the fill and clay to depths of approximately 7 feet BGS. The sand layer appears to be a transition zone between the overlying fine-grained material and the underlying dense gravel. Based on laboratory testing, the moisture content of the sand layer varied from 12 and 25 percent at the time of our explorations.

4.3.6 Gravel

Gravel was observed below the fill, sandy clay, and sand layers to the maximum depth explored of 31.5 feet BGS. The gravel is generally medium dense to very dense with cobbles and variable amounts of clay, sand, and silt. Based on explorations completed in the project vicinity, boulders are anticipated in the gravel unit. The moisture content of the gravel varied between 6 and 18 percent at the time of our explorations.

4.3.7 Groundwater

Groundwater was not encountered in our hollow-stem auger borings to a maximum depth explored of 16.5 feet BGS. Groundwater could not be measured directly at greater depths due to the presence of drilling fluid in the mud rotary borings. Groundwater mapping completed by GSI Water Solutions for the Canby area is presented in Appendix B. The mapping indicates groundwater depths of approximately 20 to 50 feet BGS are expected along the project alignment.

The depth to groundwater may fluctuate in response to seasonal changes, prolonged rainfall, changes in surface topography, and other factors not observed in this study. Shallow perched groundwater is likely during extended periods of wet weather.

5.0 INFILTRATION TESTING

We conducted infiltration testing in the borings and in existing drywells A-52 and A-59 to evaluate stormwater infiltration for the project. The following sections provide descriptions of the test procedures, results, and our recommendations for design.

5.1 INFILTRATION TESTING IN BORINGS

We conducted infiltration testing in borings C-1 through C-3 at depths between 10 and 15 feet BGS. Prior to performing the tests, the exposed soil was saturated. The infiltration tests were performed using the encased falling-head method. Deep infiltration tests were performed with up to 6 feet of water head in order to simulate drywell conditions during a large storm event.

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Laboratory testing was performed on select soil samples to determine the percent fines content at infiltration test depths. Table 2 summarizes the unfactored infiltration test results and the fines content of the soil present at the infiltration test depths.

Table 2. Exploration Infiltration Test Results

Exploration Depth

(feet BGS) Material

Observed Infiltration Rate1 (inches per hour)

Water Head (feet)

Percent Fines2

C-1 10.0 Silty GRAVEL with cobbles (GM) 50 6 13

C-2 15.0 GRAVEL (GP) 100+ 1 4

C-3 10.0 Silty GRAVEL with cobbles (GM) Negligible 5 14

1. Infiltration rates are measured rates with no factor of safety.

2. Fines content: material passing the U.S. Standard No. 200 sieve

5.2 INFILTRATION TESTING IN DRYWELLS A-52 AND A-59

We conducted infiltration testing in drywells A-52 and A-59 by inflowing water at varying rates into the drywells and measuring the resulting sustained water head using a water level logger.

Drywells A-52 and A-59 were selected for testing due to their proximity to available fire hydrants.

Table 3 summarizes the measured sustained water head at each inflow rate.

Table 3. Drywell Infiltration Test Results

Drywell Depth of Drywell

(feet BGS)

Test Inflow Rate

(gpm)

Measured Sustained Water Head

(feet)

A-52 29 50 0.6 150 0.9 190 1.3

A-59 25.5 50 2.7 150 4.7 225 5.2

5.3 STORMWATER DISPOSAL DESIGN

Based on the results of infiltration testing, it is our opinion that infiltration can be achieved in the gravel unit underlying the project alignment; however, infiltration rates will be variable due to the varying amounts of silt, sand, and cobbles. Correction factors should be applied to the measured infiltration rates to account for soil variations and the potential for long-term clogging due to siltation and buildup of organic material. The infiltration rates shown in Tables 2 and 3 are short-term field rates and factors of safety have not been applied. Given the variability, we recommend a minimum factor of safety of at least 3 with the exploration results and 2 with the drywell results be applied to the field infiltration values presented above. We recommend that we be allowed to review the final design and provide comments as necessary.

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We recommend the installation of stormwater facilities be observed by a qualified geotechnical engineer or representative under their supervision to evaluate if soil conditions are consistent with subsurface conditions encountered during our explorations. Following installation, we recommend confirmation testing of infiltration facilities.

6.0 SIGNAL POLE FOUNDATION DESIGN

We understand that three mast-arm signal poles are being considered for new signaling at the intersection of South Ivy Street and SE Township Road. The signal poles will be constructed in accordance with ODOT standards. The design of traffic control structures is subject to the requirements of Chapter 16 to the ODOT Geotechnical Design Manual (November 2017) and Section 13 of AASHTO’s Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, 1st Edition (AASHTO, 2015).

We anticipate the foundations for the signal poles will consist of 36- to 48-inch-diameter drilled shafts. We anticipate that the axial loads of the signal poles will be negligible and the overturning and torsional forces will control design.

If the Brom’s design method is used to evaluate the pole foundations, the soil should be considered cohesionless and the soil reaction distribution should be modelled after the distribution shown on Figure 13-2 (AASHTO, 2015). We recommend that lateral resistance from soil within a distance of 1.5D of the ground surface be ignored in design when using Brom’s method, where D is the diameter of the shaft. Appropriate soil parameters for the Brom’s design method are presented in Table 4.

Table 4. Input Parameters for Brom’s Design Method of Laterally Loaded Piles

Soil Effective

Unit Weight, g' (pcf)

Cohesion, C (psf)

Friction Angle, (f')

Passive Earth Pressure

Coefficient Kp

Loose, Silty Sand and Medium Dense to

Dense Gravel (4.5 to 31.5 feet BGS)

120 (58)1,2 Not applicable 35 3.6

1. Values in parentheses are buoyant unit weights for soil below the groundwater table.

2. Groundwater level should be assumed at a depth of 30 feet BGS for the intersection.

If LPILE p-y curves are used to evaluate the pole foundations, deflection of the foundations should be limited to ½ inch at the shaft head. Appropriate soil parameters for the LPILE design method are presented in Table 5.

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Table 5. LPILE Input Parameters

Soil

LPILE

Soil Type

Effective Unit Weight, g'

(pcf)

Friction Angle, f'

Soil Modulus, k

(pci)

Loose, Silty Sand (4.5 to 7 feet BGS)

Sand 115 (53)1,2 30 40 (30)3

Medium Dense to Dense Gravel (7 to 31.5 feet BGS)

Sand 125 (63)1,2 38 160 (100)3

1. Values in parentheses are buoyant unit weights for soil below the groundwater table.

2. Groundwater level should be assumed at a depth of 30 feet BGS for the intersection.

3. Values in parentheses are submerged soil modulus, k, values for soil below the groundwater table.

7.0 CONSTRUCTION CONSIDERATIONS

The following sections provide general recommendations for construction of the proposed improvements related to this study.

7.1 SITE PREPARATION

We understand that existing underground utilities and other subsurface structures within the project area will need to be removed or rerouted. Soil disturbed during the removal of these items should be removed and replaced with structural fill in areas located in the influence zone of pavement or other structures. Voids resulting from the removal process should be backfilled with compacted structural fill. Material generated during demolition should be transported off site for disposal.

7.2 WET WEATHER CONSIDERATIONS

The on-site soil will provide poor support for construction traffic during periods of extended wet weather or when the moisture content of the surficial soil is more than a few percentage points above optimum. If not carefully executed, site preparation, utility trench work, and excavation can create extensive soft areas and will result in significant subgrade repair costs where the native soil is exposed. If construction is planned when the surficial soil is wet of optimum moisture content or during wet weather, the construction methods and schedule should be carefully considered with respect to protecting the subgrade to reduce the need to over-excavate disturbed or softened soil. When possible, construction equipment should work off existing AC surfacing and before the existing AC pavement is replaced or rehabilitated. The project budget should include a contingency reflecting the following recommendations if construction is planned during wet weather or when the surficial soil is wet.

Generally, a 12- to 18-inch-thick granular pad is sufficient for light staging areas but is not expected to be adequate to support heavy equipment or truck traffic for haul roads and areas with repeated heavy construction. In our experience, an 18- to 24-inch section should be adequate. The actual thickness of haul roads and staging areas should be based on the contractor’s approach to site development and the amount and type of construction traffic.

Consequently, the contractor should be responsible for selecting the locations of staging areas and haul roads and selecting the appropriate thickness of granular material for these areas.

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7.3 EXCAVATION

7.3.1 General

The clay and sand layers near the ground surface should be excavatable with conventional earthwork equipment. The site is underlain by medium dense to dense gravel with cobbles and boulders. The gravel, cobbles, and boulders will lead to difficult excavation conditions, including the following:

Excavation volumes may be greater than anticipated due to sloughing, caving, and the need to remove oversized material.

Boulders will likely be encountered during excavations, and we recommend that project bid documents include a contingency for boulder removal, as well as the associated increased volumes for backfilling.

Specialized excavation equipment may be required to remove cobbles and boulders.

7.3.2 Trench Cuts

Trench cuts should stand near vertical to a depth of at least 4 feet. Open excavation techniques may be used to excavate trenches with depths between 4 and 8 feet, provided the walls of the excavation are cut at a slope of 1H:1V, groundwater seepage is not present, and with the understanding that some sloughing may occur. Excavations should be flattened to 1½H:1V if excessive sloughing occurs. Excavations that extend into the dense gravel unit will likely encounter difficult excavation conditions as well as cobbles and boulders.

7.3.3 Shoring

If box shoring is used, it should be understood that box shoring is a safety feature used to protect workers and does not prevent caving. If the excavations are left open for extended periods of time, caving of the sidewalls may occur. The presence of caved material will limit the ability to properly place and compact backfill material. The contractor should be prepared to fill voids between the box shoring and the sidewalls of excavations with sand or gravel before caving occurs.

If shoring is used, we recommend that the type and design of the shoring system be the responsibility of the contractor, who is in the best position to choose a system that fits the overall plan of operation. All excavations should be made in accordance with applicable OSHA and state regulations.

7.3.4 Safety

All excavations should be made in accordance with applicable OSHA requirements and regulations of the state, county, and local jurisdiction. While this report describes certain approaches to excavation and dewatering, the contract documents should specify that the contractor is responsible for selecting excavation and dewatering methods, monitoring the excavations for safety, and providing shoring (as required) to protect personnel and adjacent structural elements.

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7.3.5 Dewatering

Excavations likely will not encounter static groundwater and significant dewatering operations will not be necessary. If storm runoff seeps into trenches, it should be removed by pumping from a sump. Water should be routed to a suitable discharge point.

7.4 MATERIALS

7.4.1 Structural Fill

7.4.1.1 General

A variety of granular material may be used as structural fill at the site; however, all material used as structural fill should be free of organic material or other unsuitable material. A brief characterization of some of the acceptable materials and our recommendations for their use as structural fill are provided below.

7.4.1.2 Imported Granular Material

Imported granular material used as structural fill should be pit- or quarry-run rock, crushed rock, or crushed gravel and sand. The imported granular material should also be angular, should be fairly well graded between coarse and fine material, should have less than 5 percent fines (material passing the U.S. Standard No. 200 sieve) by dry weight, and should have at least two mechanically fractured faces.

Imported granular 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 AASHTO T 99. During the wet season or when wet subgrade conditions exists, the initial lift should be approximately 18 inches in uncompacted thickness and should be compacted by rolling with a smooth-drum roller without using vibratory action.

7.4.1.3 Stabilization Material

Stabilization material used in staging or haul road areas or in trenches should consist of 4- or 6-inch-minus pit- or quarry-run rock, crushed rock, or crushed gravel and sand. The material should have a maximum particle size of 6 inches, should have less than 5 percent by dry weight passing the U.S. Standard No. 4 sieve (washed analysis), and should have at least two mechanically fractured faces. The material should be free of organic material and other deleterious material. Stabilization material should be placed in lifts between 12 and 24 inches thick and compacted to a firm and well-keyed condition.

7.4.1.4 Trench Backfill

Trench backfill for utility pipe bases and pipe zones should consist of well-graded, granular material with a maximum particle size of 1 inch, should have less than 7 percent by dry weight passing the U.S. Standard No. 200 sieve, and should meet OSSC 00405.12 (Bedding) and OSSC 00405.13 (Pipe Zone). The material should be free of roots, organic material, and other unsuitable material and should have at least two mechanically fractured faces. The pipe zone backfill should be compacted to at least 90 percent of the maximum dry density, as determined by AASHTO T 99, or as required by the pipe manufacturer.

Within roadway alignments, the remainder of the trench backfill up to the subgrade elevation should consist of granular material meeting the requirements above and with a maximum

10 ClackCo-105-01:021420 particle size of 2½ inches. This material should be compacted to at least 95 percent of the maximum dry density, as determined by AASHTO T 99, or as required by the pipe manufacturer.

The upper 3 feet of the trench backfill should be compacted to at least 95 percent of the maximum dry density, as determined by AASHTO T 99.

Outside of structural improvement areas (e.g., roadway alignments and other structures) trench backfill placed above the pipe zone may consist of general fill material that is free of organic material and material over 6 inches in diameter. This general trench backfill should be compacted to at least 90 percent of the maximum dry density, as determined by AASHTO T 99, or as required by the pipe manufacturer.

7.4.1.5 Pavement Aggregate Base

Imported granular material used as base rock for pavement should consist of ¾- or 1½-inch-minus material (depending on the application). In addition, the aggregate should have less than 5 percent fines by dry weight (washed analysis) and at least two fractured faces. The aggregate base should be compacted to not less than 95 percent of the maximum dry density, as determined by AASHTO T 99.

7.4.1.6 Drain Rock Material

Drain rock should consist of angular, granular material with a maximum particle size of 2 inches.

The material should be free of roots, organic material, and other unsuitable material; should have less than 2 percent by dry weight passing the U.S. Standard No. 200 sieve (washed analysis); and should have at least at least two mechanically fractured faces.

We recommend drain rock be separated from general fill, native soil, and/or topsoil using a geotextile fabric that meets the specifications provided below for drainage geotextiles.

7.4.2 Drainage Geotextile Fabric

Drainage geotextile fabric should meet the specifications provided in OSSC Table 02320-1 - Geotextile Property Values for Drainage Geotextile. The geotextile should be installed in conformance with OSSC 00350 (Geosynthetic Installation). A minimum initial aggregate base lift of 6 inches is required over geotextiles.

7.5 EROSION CONTROL

The site soil is susceptible to erosion; therefore, erosion control measures should be carefully planned and in place before construction begins. Surface water runoff should be collected and directed away from slopes to prevent water from running down the slope face. Erosion control measures (such as straw bales, sediment fences, and temporary detention and settling basins) should be used in accordance with local and state ordinances.

8.0 OBSERVATION OF CONSTRUCTION

Satisfactory earthwork performance depends to a large degree on quality of construction.

Sufficient observation of the contractor's activities is a key part of determining that the work is completed in accordance with the construction drawings and specifications. Subsurface conditions observed during construction should be compared with those encountered during the

11 ClackCo-105-01:021420 subsurface explorations. 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.

9.0 LIMITATIONS

We have prepared this report for use by Kittelson & Associates, Inc., Clackamas County, and members of the design and construction teams 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 nearby building 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, re-evaluation 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, 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 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 this report for consideration in design.

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 this report was prepared.

No warranty, express or implied, should be understood.

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We appreciate the opportunity to be of service to you. Please call if you have questions concerning this report or if we can provide additional services.

Sincerely, GeoDesign, Inc.

Jordan L. Melby, P.E.

Project Engineer

Krey D. Younger, P.E., G.E.

Senior Associate Engineer

George Saunders, P.E., G.E.

Principal Engineer

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REFERENCES

Allen, J.E., Burns, M., and Sargent, S.C., 1986, Cataclysms on the Columbia. Timber Press, Portland, Oregon: 211p.

Burns, W.J., and Coe, D.E., 2012, Missoula Floods – Inundation Extent and Primary Flood Features in the Portland Metro Area. Oregon Department of Geology and Mineral Industries, IMS-36.

Burns, S., Growney, L., Broderson, B., Yeats, R.S., and Popowski, T.A., 1997, Map showing faults, bedrock geology, and sediment thickness of the western half of the Oregon City 1:100,000 quadrangle, Washington, Multnomah, Clackamas, and Marion Counties, Oregon. Oregon Department of Geology and Mineral Industries, IMS-4, scale 1:100,000.

Evarts, R.C., O’Connor, J.E., and Tolan, T.L., 2013, Geologic Map of the Washougal Quadrangle, Clark County, Washington and Multnomah County, Oregon. U.S. Geological Survey Scientific Investigations Map 3257.

Gannett, M.W. and Caldwell, R.R., 1998, Geologic Framework of the Willamette Lowland Aquifer System, Oregon and Washington. U.S. Geological Survey Professional Paper 1424-A, 32p, 8 plates.

O’Connor, J.E., Sarna-Wojcicki, A., Wozniak, K.C., Polette, D.J., and Fleck, R.J., 2001, Origin, Extent and Thickness of Quaternary Geologic Units in the Willamette Valley, Oregon.

U.S. Geological Survey Professional Paper 1620, 62 p.

ODOT, 2018. Oregon Standard Specifications for Construction, Oregon Department of Transportation, 2018 Edition.

Orr, E.L. and Orr, W.N., 1999, Geology of Oregon. Kendall/Hunt Publishing Company, Iowa:

254p.

Tolan, T.L., and Beeson, M.H., 1984, Intracanyon Flows of the Columbia River Basalt Group in the Lower Columbia Gorge and Their Relationship to the Troutdale Formation. GSA Bulletin 95 (4),

pp. 463 to 477.

FIGURES

SITE

Pr in te d B y:

a d ay

P ri n t

D at e:

/1

/2

:4

:4

P

M

Fi le

N am e:

J:

\A

-D \C la ck

C o \c la ck co -1

\c la ck co

-1

-0

\F ig u re s\ C

A D

\C la ck C o -1

-0

-V M

.d w g L ay o u t:

F

IG

U R

E

AN COMPANY

VICINITY MAP

SOUTH IVY STREET PEDESTRIAN INTERSECTION

CLACKCAMAS COUNTY, OR

CLACKCO-105-01

FEBRUARY 2020 FIGURE 1

(SCALE IN APPROXIMATE FEET)

N

2000 4000VICINITY MAP BASED ON AERIAL

PHOTOGRAPH OBTAINED FROM

GOOGLE EARTH PRO®

C-1 C-2 C-4 C-3 S IVY STREET

S

S T

A V

E N

U E

S

N D

A V

E N

U E

S

R D

A V

E N

U E

S T O

W N

SH

IP

R O

A D

P A

C

IF

IC

H

IG

H

W A

Y E

A-59

SW

T H

A V

EN

U E

S W

T

H P

L A

C E

A-52

Pr in te d B y:

a d ay ri n t

D at e:

/1

/2

:4

:5

P

M

Fi le

N am e:

J:

\A

-D \C la ck

C o \c la ck co -1

\c la ck co

-1

-0

\F ig u re s\ C

A D

\C la ck C o -1

-0

-S P0

.d w g L ay o u t:

F

IG

U R

E

A N

C O

M P A

N Y

S

IT

E P

L A

N

SO

U

T H

I V

Y S

T R

EE

T

P

ED

ES

T

R

IA

N I N

T

ER

SE

C

T

IO

N C

LA

C

K C

A M

A S

C O

U N

T Y

O R

C

LA

C K

C O

-1

-0

FE

B R

U A

R Y

F

IG

U R

E

(SCALE IN FEET)

N

250 500

SITE PLAN BASED ON AERIAL PHOTOGRAPH

OBTAINED FROM GOOGLE EARTH PRO®,

DECEMBER 23, 2019

LEGEND:

BORING

TESTED DRYWELL

C-1

A-52

APPENDIX A

A-1 ClackCo-105-01:021420

APPENDIX A

FIELD EXPLORATIONS

GENERAL

We explored subsurface conditions at the site by drilling four borings (C-1 through C-4) to depths of between 14 and 31.5 feet BGS. The explorations were completed by Western States Soil Conservation, Inc. of Hubbard, Oregon, on December 11 and 12, 2019. Borings C-1, C-2, and the top 10 feet of boring C-3 were drilled using an 8-inch-diameter hollow-stem auger to facilitate infiltration testing. Boring C-4 and the lower portion of boring C-3 were drilled using mud rotary methods.

The locations of the explorations are shown on Figure 2. The locations of the explorations are based on coordinates collected from a hand-held GPS unit and should be considered accurate to the degree in which they were measured.

SOIL SAMPLING

Samples were collected from the borings using 1½-inch-inner diameter SPT split-barrel sampler in general accordance with ASTM D1586. The sampler was driven into the soil with a 140-pound hammer free-falling 30 inches. The sampler was driven a total distance of 18 inches. The number of blows required to drive the sampler the final 12 inches is recorded on the exploration logs, unless otherwise noted. Samples were generally collected at 2.5- to 5-foot intervals throughout the depth of the borings. Sampling methods and intervals are shown on the exploration logs.

The average efficiency of the automatic SPT hammer used by Western States Soil Conservation, Inc. was 86 percent. The calibration testing results are presented at the end of this appendix.

SOIL CLASSIFICATION

The soil samples were classified in accordance with the “Explorations Key” (Table A-1) and “Soil Classification System” (Table A-2), which are presented in this appendix. The exploration 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 are shown on the exploration logs.

LABORATORY TESTING

We visually examined soil samples collected from the explorations to confirm field classifications. We also performed the following laboratory testing.

MOISTURE CONTENT

We tested the natural moisture content of select soil samples in general accordance with ASTM D2216. The natural moisture content is a ratio of the weight of the water to soil in a test sample and is expressed as a percentage. The test results are presented in this appendix.

A-2 ClackCo-105-01:021420

PARTICLE-SIZE ANALYSIS

We completed particle-size analysis on select soil samples in general accordance with ASTM C117. The tests determined the percent fines (passing the U.S. Standard No. 200 sieve) only. The test results are presented in this appendix.

SYMBOL SAMPLING DESCRIPTION

Location of sample collected in general accordance with ASTM D1586 using Standard Penetration Test with recovery

Location of sample collected using thin-wall Shelby tube or Geoprobe® sampler in general accordance with ASTM D1587 with recovery

Location of sample collected using Dames & Moore sampler and 300-pound hammer or pushed with recovery

Location of sample collected using Dames & Moore sampler and 140-pound hammer or pushed with recovery

Location of sample collected using 3-inch-O.D. California split-spoon sampler and 140-pound hammer with recovery

Location of grab sample

Rock coring interval

Water level during drilling

Water level taken on date shown

GEOTECHNICAL TESTING EXPLANATIONS

ATT

CBR

CON

DD

DS

HYD

MC

MD

NP

OC

Atterberg Limits

California Bearing Ratio

Consolidation

Dry Density

Direct Shear

Hydrometer Gradation

Moisture Content

Moisture-Density Relationship

Non-Plastic

Organic Content

P

PP

P200

RES

SIEV

TOR

UC

VS

kPa

Pushed Sample

Pocket Penetrometer

Percent Passing U.S. Standard No. 200 Sieve

Resilient Modulus

Sieve Gradation

Torvane

Unconfined Compressive Strength

Vane Shear

Kilopascal

ENVIRONMENTAL TESTING EXPLANATIONS

CA

PID

ppm

Sample Submitted for Chemical Analysis

Pushed Sample

Photoionization Detector Headspace Analysis

Parts per Million

ND

NS

SS

MS

HS

Not Detected

No Visible Sheen

Slight Sheen

Moderate Sheen

Heavy Sheen

EXPLORATION KEY TABLE A-1

Graphic Log of Soil and Rock Types

Inferred contact between soil or rock units (at approximate depths indicated)

Observed contact between soil or rock units (at depth indicated)

RELATIVE DENSITY - COARSE-GRAINED SOIL

Relative Density Standard Penetration

Resistance Dames & Moore Sampler

(140-pound hammer) Dames & Moore Sampler

(300-pound hammer)

Very Loose 0 – 4 0 – 11 0 – 4 Loose 4 – 10 11 – 26 4 – 10

Medium Dense 10 – 30 26 – 74 10 – 30 Dense 30 – 50 74 – 120 30 – 47

Very Dense More than 50 More than 120 More than 47

CONSISTENCY - FINE-GRAINED SOIL

Consistency Standard

Penetration Resistance

Dames & Moore Sampler

(140-pound hammer)

Dames & Moore Sampler

(300-pound hammer)

Unconfined Compressive Strength

(tsf) Very Soft Less than 2 Less than 3 Less than 2 Less than 0.25

Soft 2 – 4 3 – 6 2 – 5 0.25 – 0.50 Medium Stiff 4 – 8 6 – 12 5 – 9 0.50 – 1.0

Stiff 8 – 15 12 – 25 9 – 19 1.0 – 2.0 Very Stiff 15 – 30 25 – 65 19 – 31 2.0 – 4.0

Hard More than 30 More than 65 More than 31 More than 4.0

PRIMARY SOIL DIVISIONS GROUP SYMBOL GROUP NAME

COARSE-

GRAINED SOIL

(more than 50% retained on No. 200 sieve)

GRAVEL

(more than 50% of coarse fraction retained on No. 4 sieve)

CLEAN GRAVEL

(< 5% fines) GW or GP GRAVEL

GRAVEL WITH FINES

(≥ 5% and ≤ 12% fines)

GW-GM or GP-GM GRAVEL with silt

GW-GC or GP-GC GRAVEL with clay

GRAVEL WITH FINES

(> 12% fines)

GM silty GRAVEL GC clayey GRAVEL

GC-GM silty, clayey GRAVEL

SAND

(50% or more of coarse fraction passing No. 4 sieve)

CLEAN SAND

(<5% fines) SW or SP SAND

SAND WITH FINES

(≥ 5% and ≤ 12% fines)

SW-SM or SP-SM SAND with silt

SW-SC or SP-SC SAND with clay

SAND WITH FINES

(> 12% fines)

SM silty SAND SC clayey SAND

SC-SM silty, clayey SAND

FINE-GRAINED

SOIL

(50% or more passing No. 200 sieve)

SILT AND CLAY

Liquid limit less than 50

ML SILT

CL CLAY

CL-ML silty CLAY OL ORGANIC SILT or ORGANIC CLAY

Liquid limit 50 or greater

MH SILT

CH CLAY

OH ORGANIC SILT or ORGANIC CLAY

HIGHLY ORGANIC SOIL PT PEAT

MOISTURE

CLASSIFICATION

ADDITIONAL CONSTITUENTS

Term Field Test

Secondary granular components or other materials such as organics, man-made debris, etc.

Percent

Silt and Clay In:

Percent

Sand and Gravel In:

dry very low moisture, dry to touch

Fine-Grained Soil

Coarse- Grained Soil

Fine-Grained Soil

Coarse- Grained Soil moist damp, without visible moisture

< 5 trace trace < 5 trace trace 5 – 12 minor with 5 – 15 minor minor wet visible free water, usually saturated

> 12 some silty/clayey 15 – 30 with with > 30 sandy/gravelly Indicate %

SOIL CLASSIFICATION SYSTEM TABLE A-2

Infiltration test at 10 feet.

P200 = 13%

P200 = 18%

Surface elevation was not measured at the time of exploration.

0.3

1.1

4.5

10.0

12.0

14.0

P200

P200

ASPHALT CONCRETE (3.0 inches).

PORTLAND CEMENT CONCRETE (10.0

inches).

Very soft to soft, dark brown SILT (ML), minor gravel, sand, and clay; moist, silt has low plasticity - FILL.

Very dense, orange-brown GRAVEL with silt and cobbles (GP-GM), minor sand, trace clay; moist, gravel is subrounded.

Dense, light gray-brown, silty GRAVEL with cobbles (GM), minor sand, trace clay; moist, gravel is subrounded.

Medium dense, brown with gray mottled GRAVEL with clay (GP-GC), minor sand; moist, gravel is subrounded.

Exploration completed at a depth of

14.0 feet.

Hammer efficiency factor is 86.0 percent.

INSTALLATION AND

COMMENTS

MOISTURE CONTENT %

CORE REC%RQD%

BLOW COUNT

BORING C-1

COMPLETED: 12/11/19

FIGURE A-1

BORING BIT DIAMETER: 8 inches

CLACKAMAS COUNTY, OR

CLACKCO-105-01

SOUTH IVY STREET PEDESTRIAN INTERSECTION

MATERIAL DESCRIPTION

T

ES

T

IN

G

DEPTH

FEET

LOGGED BY: J. Hook

FEBRUARY 2020

BORING METHOD: hollow-stem auger (see document text)

DRILLED BY: Western States Soil Conservation, Inc.

G R

A

PH

IC

L

O G

SA

M

PL

E

EL

EV

A T

IO

N

D

EP

T H

B O

R

IN

G L

O G

G

D I- N

V

P

ER

P A

G E

C

LA

C K

C O

-1

-0

-C

_4

.G

PJ

G

D I_

N V

.G

T

PR

IN

T

D A

T E:

/1

/2

:K

M

0 50 100

0 50 100

0.0

2.5

5.0

7.5

10.0

12.5

15.0

17.5

20.0

P200 = 16%

Infiltration test at 15 feet.

P200 = 4%

Surface elevation was not measured at the time of exploration.

0.3

0.8

4.5

7.0

12.0

14.5

16.5

P200

P200

ASPHALT CONCRETE (4.0 inches).

PORTLAND CEMENT CONCRETE (6.0

inches).

Very loose, brown, clayey SAND (SC), trace silt; moist, sand is fine - FILL.

Medium dense, brown SAND with silt and gravel (SP-SM); moist, sand is fine to medium, gravel is subrounded.

Very dense, gray-brown GRAVEL with silt (GP-GM), minor sand, trace clay;

moist, gravel is subrounded.

Dense, brown, clayey GRAVEL (GC), minor sand; moist, gravel is subrounded to subangular.

Very dense, gray GRAVEL (GP), minor sand, trace clay; moist.

Exploration completed at a depth of

16.5 feet.

Hammer efficiency factor is 86.0 percent.

INSTALLATION AND

COMMENTS

MOISTURE CONTENT %

CORE REC%RQD%

BLOW COUNT

BORING C-2

COMPLETED: 12/11/19

FIGURE A-2

BORING BIT DIAMETER: 8 inches

CLACKAMAS COUNTY, OR

CLACKCO-105-01

SOUTH IVY STREET PEDESTRIAN INTERSECTION

MATERIAL DESCRIPTION

T

ES

T

IN

G

DEPTH

FEET

LOGGED BY: J. Hook

FEBRUARY 2020

BORING METHOD: hollow-stem auger (see document text)

DRILLED BY: Western States Soil Conservation, Inc.

G R

A

PH

IC

L

O G

SA

M

PL

E

EL

EV

A T

IO

N

D

EP

T H

B O

R

IN

G L

O G

G

D I- N

V

P

ER

P A

G E

C

LA

C K

C O

-1

-0

-C

_4

I_

N V

.G

T

D A

T E:

/1

/2

:K

M

7-11-50/3"

14-38-50/5"

0 50 100

0 50 100

0.0

2.5

5.0

7.5

10.0

12.5

15.0

17.5

20.0

PP = 0.75 tsf

Infiltration test at 10 feet.

P200 = 14%

0.7

1.0

4.5

7.0

15.0

PP

P200

ASPHALT CONCRETE (8.0 inches).

AGGREGATE BASE (4.0 inches).

Soft to medium stiff, brown, sandy CLAY (CL), minor silt; moist, clay has medium plasticity.

Loose, light brown, silty SAND (SM);

moist, sand is fine to medium.

minor gravel at 6.5 feet

Dense, gray-brown, silty GRAVEL with cobbles (GM), minor sand, trace clay;

moist, gravel is rounded.

Medium dense to dense, gray-brown GRAVEL with clay, sand, and cobbles (GP-GC); moist, gravel is subrounded.

INSTALLATION AND

COMMENTS

MOISTURE CONTENT %

CORE REC%RQD%

BLOW COUNT

BORING C-3

COMPLETED: 12/12/19

FIGURE A-3

BORING BIT DIAMETER: 8 inches and 4 7/8 inches

CLACKAMAS COUNTY, OR

CLACKCO-105-01

SOUTH IVY STREET PEDESTRIAN INTERSECTION

MATERIAL DESCRIPTION

T

ES

T

IN

G

DEPTH

FEET

LOGGED BY: J. Hook

FEBRUARY 2020

BORING METHOD: hollow-stem auger and mud rotary (see document text)

DRILLED BY: Western States Soil Conservation, Inc.

G R

A

PH

IC

L

O G

SA

M

PL

E

EL

EV

A T

IO

N

D

EP

T H

B O

R

IN

G L

O G

G

D I- N

V

P

ER

P A

G E

C

LA

C K

C O

-1

-0

-C

_4

I_

N V

.G

T

D A

T E:

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M

0 50 100

0 50 100

0.0

2.5

5.0

7.5

10.0

12.5

15.0

17.5

20.0

Surface elevation was not measured at the time of exploration.

31.5

(continued from previous page) light gray-brown at 30.0 feet

Exploration completed at a depth of

31.5 feet.

Hammer efficiency factor is 86.0 percent.

INSTALLATION AND

COMMENTS

MOISTURE CONTENT %

CORE REC%RQD%

BLOW COUNT

BORING C-3

COMPLETED: 12/12/19

FIGURE A-3

BORING BIT DIAMETER: 8 inches and 4 7/8 inches

CLACKAMAS COUNTY, OR

CLACKCO-105-01

SOUTH IVY STREET PEDESTRIAN INTERSECTION

MATERIAL DESCRIPTION

T

ES

T

IN

G

(continued)

DEPTH

FEET

LOGGED BY: J. Hook

FEBRUARY 2020

BORING METHOD: hollow-stem auger and mud rotary (see document text)

DRILLED BY: Western States Soil Conservation, Inc.

G R

A

PH

IC

L

O G

SA

M

PL

E

EL

EV

A T

IO

N

D

EP

T H

B O

R

IN

G L

O G

G

D I- N

V

P

ER

P A

G E

C

LA

C K

C O

-1

-0

-C

_4

I_

N V

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T

D A

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M

0 50 100

0 50 100

20.0

22.5

25.0

27.5

30.0

32.5

35.0

37.5

40.0

P200 = 15%

0.7

1.2

P200

ASPHALT CONCRETE (8.0 inches).

AGGREGATE BASE (6.0 inches).

Very dense, light brown to brown GRAVEL with clay (GP-GC), minor sand;

moist, gravel is subrounded.

dense, with cobbles at 10.0 feet

INSTALLATION AND

COMMENTS

MOISTURE CONTENT %

CORE REC%RQD%

BLOW COUNT

BORING C-4

COMPLETED: 12/12/19

FIGURE A-4

BORING BIT DIAMETER: 4 7/8 inches

CLACKAMAS COUNTY, OR

CLACKCO-105-01

SOUTH IVY STREET PEDESTRIAN INTERSECTION

MATERIAL DESCRIPTION

T

ES

T

IN

G

DEPTH

FEET

LOGGED BY: J. Hook

FEBRUARY 2020

BORING METHOD: mud rotary (see document text)

DRILLED BY: Western States Soil Conservation, Inc.

G R

A

PH

IC

L

O G

SA

M

PL

E

EL

EV

A T

IO

N

D

EP

T H

B O

R

IN

G L

O G

G

D I- N

V

P

ER

P A

G E

C

LA

C K

C O

-1

-0

-C

_4

I_

N V

.G

T

D A

T E:

/1

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:K

M

14-34-50/6"

0 50 100

0 50 100

0.0

2.5

5.0

7.5

10.0

12.5

15.0

17.5

20.0

Surface elevation was not measured at the time of exploration.

31.5 light gray-brown at 20.0 feet medium dense at 30.0 feet

Exploration completed at a depth of

31.5 feet.

Hammer efficiency factor is 86.0 percent.

INSTALLATION AND

COMMENTS

MOISTURE CONTENT %

CORE REC%RQD%

BLOW COUNT

BORING C-4

COMPLETED: 12/12/19

FIGURE A-4

BORING BIT DIAMETER: 4 7/8 inches

CLACKAMAS COUNTY, OR

CLACKCO-105-01

SOUTH IVY STREET PEDESTRIAN INTERSECTION

MATERIAL DESCRIPTION

T

ES

T

IN

G

(continued)

DEPTH

FEET

LOGGED BY: J. Hook

FEBRUARY 2020

BORING METHOD: mud rotary (see document text)

DRILLED BY: Western States Soil Conservation, Inc.

G R

A

PH

IC

L

O G

SA

M

PL

E

EL

EV

A T

IO

N

D

EP

T H

B O

R

IN

G L

O G

G

D I- N

V

P

ER

P A

G E

C

LA

C K

C O

-1

-0

-C

_4

I_

N V

.G

T

D A

T E:

/1

/2

:K

M

0 50 100

0 50 100

20.0

22.5

25.0

27.5

30.0

32.5

35.0

37.5

40.0

C-1 2.5 27

C-1 5.0 6

C-1 10.0 9 13

C-1 12.5 16 18

C-2 2.5 21

C-2 5.0 12

C-2 10.0 10 16

C-2 12.5 10

C-2 15.0 10 4

C-3 2.5 21

C-3 5.0 25

C-3 10.0 12 14

C-3 20.0 18

C-4 5.0 15

C-4 10.0 12 15

C-4 20.0 15

GRAVEL

(PERCENT)

SAMPLE

DEPTH

(FEET)

SUMMARY OF LABORATORY DATA

ELEVATION

(FEET)

P200

(PERCENT)

SIEVE

PLASTIC

LIMIT

PLASTICITY

INDEX

ATTERBERG LIMITS

MOISTURE

CONTENT

(PERCENT)

SAMPLE INFORMATION

EXPLORATION

NUMBER

SAND

(PERCENT)

DRY

DENSITY

(PCF)

LIQUID

LIMIT

CLACKCO-105-01

FEBRUARY 2020 SOUTH IVY STREET PEDESTRIAN INTERSECTION

CLACKAMAS COUNTY, OR FIGURE A-5

LA

B S

U M

M A

R Y

G D

I- N

V

C

LA

C

K C

O -1

-0

-C

_4

I_ N

V

.G

T D

A T

E:

/1

/2

:K M

Pile Dynamics, Inc.

SPT Analyzer Results PDA-S Ver. 2017.22 - Printed: 1/4/2019

Summary of SPT Test Results

Project: WSSC-8-04, Test Date: 12/27/2018

EMX: Maximum Energy ETR: Energy Transfer Ratio - Rated

Start Final N N60 Average Average

Depth Depth Value Value EMX ETR ft ft ft-lb %

25.00 26.50 20 28 300.86 86.0

30.00 31.50 0 0 0.00 0.0

35.00 36.50 0 0 0.00 0.0

40.00 41.50 0 0 0.00 0.0

Overall Average Values: 300.86 86.0

Standard Deviation: 20.24 5.8

Overall Maximum Value: 342.80 97.9

Overall Minimum Value: 276.33 79.0

RIG #9

APPENDIX B

B-1 ClackCo-105-01:021420

APPENDIX B

GROUNDWATER MAP

Groundwater mapping of the Canby area completed by GSI Water Solutions, Inc. is presented in this appendix.

FIGURE 4

City of Canby Groundwater Protectiveness Demonstration

MAP NOTES:

Date: August 28, 2013 Data Sources: OWRD, USGS, METRO RLIS, OGIC, Elevation data based on NGVD 1927 vertical datum

7.65 (1)

5.05 (1)

52.05 (1)

21.05 (2)

28.55 (4) 31.55 (4) 74.05 (2)

89.55 (2)

48.05 (1)

42.05 (2)

52.05 (1)

48.05 (2)

47.05 (1)

34.05 (1) 45.05 (2)

19.05 (1)

45.05 (1) 40.05 (3)

47.05 (2) 45.05 (3)

26.55 (4) 12.05 (1)

21.05 (2) 20.05 (1)

31.0…