SUBMITTED TO: Marion County Public Works 5155 Silverton Road Salem, Oregon 97305

BY: Shannon & Wilson, Inc. 3990 Collins Way, Suite 100 Lake Oswego, OR 97035

503-210-4750 www.shannonwilson.com

GEOTECHNICAL ENGINEERING REPORT Silverton Road: Little Pudding River Bridge Replacement MARION COUNTY, OREGON

November 27, 2018 Shannon & Wilson No: 24-1-04094

Silverton Road: Little Pudding River Bridge Replacement Geotechnical Engineering Report

CONTENTS 1 Introduction ...... 1 2 Project Understanding ...... 1 2.1 Site Description ...... 1 2.2 Project Description ...... 2 2.3 Anticipated Construction Sequencing ...... 3 2.4 Scope of Services ...... 3 3 GEOLOGIC AND SEISMIC SETTING ...... 4 3.1 Regional Geology ...... 4 3.2 Local Geology ...... 4 3.3 Seismic Setting ...... 5 4 FIELD EXPLORATION AND LABORATORY TESTING ...... 7 4.1 Geotechnical Exploration ...... 7 4.1.1 Borehole and Sampling ...... 7

4.1.2 Dynamic Cone Penetration Test ...... 7 4.2 Laboratory Testing ...... 8 5 SUBSURFACE CONDITIONS ...... 8 5.1 Subsurface Soil Units ...... 8 CONTENTS 5.1.1 Fill ...... 9 5.1.2 Missoula Flood Deposits – Fine Facies ...... 9 5.1.3 Pleistocene Sand and Gravel ...... 9 5.2 Groundwater...... 10 6 SITE-SPECIFIC SEISMIC HAZARD EVALUATION ...... 10 6.1 Site Class ...... 10 6.2 Seismic Parameters – “Life Safety” Criteria ...... 11 6.3 Deterministic Response Spectra – “Operational” Criteria ...... 11 6.4 Liquefaction and Its Consequences ...... 12 6.4.1 Liquefaction-Induced Settlement ...... 13 6.4.2 Liquefaction-Induced Slope Instability ...... 13 7 ENGINEERING CONCLUSIONS AND RECOMMENDATIONS ...... 14 7.1 Foundation Types and Alternatives ...... 14

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7.2 Drilled Shafts for Abutment Foundations ...... 15 7.2.1 Drilled Shaft Axial Resistance ...... 16 7.2.2 Downdrag on the Drilled Shafts ...... 17 7.2.3 Drilled Shaft Lateral Resistance...... 17 7.2.4 Additional Lateral Load Due to Flow Failure ...... 21 7.2.5 Drilled Shaft Construction Considerations ...... 21 7.2.5.1 Potential Obstructions ...... 22 7.2.5.2 Shaft Quality Control ...... 22 7.3 Abutment Retaining Walls ...... 22 7.3.1 Earth Pressures - Abutment Retaining Walls ...... 23 7.3.2 Global Stability - Abutment Retaining Walls ...... 23 7.3.3 Retaining Wall Backfill Material and Drainage – Abutment Retaining Walls ...... 24 7.4 Embankment Retaining Walls ...... 24

7.4.1 Retaining Wall Types and Alternatives ...... 24 7.4.2 MSE Retaining Wall Geometry and Soil Parameters ...... 25 7.4.3 Lateral Earth Pressures - MSE Walls ...... 26 7.4.4 Soil Bearing Resistance - MSE Walls ...... 26 CONTENTS 7.4.5 Settlement - MSE Walls ...... 26 7.4.6 Lateral Sliding Resistance – MSE Walls ...... 27 7.4.7 Global Stability – MSE Walls ...... 27 7.4.8 MSE Wall Material and Compaction ...... 28 7.4.9 Retaining Wall Backfill Material and Drainage – MSE Walls ...... 28 7.5 Embankment Fills ...... 29 7.5.1 Embankment Material and Compaction ...... 29 7.5.2 Embankment Slope ...... 29 7.5.3 Embankment Settlement ...... 29 7.5.4 Embankment Construction Considerations ...... 30 7.6 Pavement Design Recommendations ...... 30 7.6.1 Traffic Data ...... 31 7.6.2 Subgrade ...... 31

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7.6.3 ACP Design Recommendations ...... 32 7.6.3.1 ACP Design Parameters ...... 32 7.6.3.2 Recommended New ACP Section ...... 32 8 GENERAL CONSTRUCTION CONSIDERATIONS ...... 33 8.1 Site Preparation ...... 33 8.2 Temporary Cut and Fill Slopes ...... 33 8.3 Temporary Shoring ...... 33 8.4 Dewatering & Control of Surface Water ...... 34 9 LIMITATIONS ...... 34 10 References ...... 35

Exhibits Exhibit 3-1: USGS Class A Quaternary Faults within an Approximate 30-Mile Radius of the Project Site ...... 6 Exhibit 6-1: "Life Safety" Criteria Seismic Parameters ...... 11

Exhibit 6-2: "Operational" Criteria Acceleration Response Spectrum (VS30 = 200 m/s) ...... 12 Exhibit 7-1: Bridge Abutment Foundation Alternatives...... 15 Exhibit 7-2: Estimated Drilled Shaft Length and Compressive Resistance ...... 16 Exhibit 7-3: LPILE Input Parameters for Drilled Shaft Foundations at Abutments - Static &

CONTENTS Seismic Conditions ...... 18 Exhibit 7-4: LPILE Input Parameters for Drilled Shaft Foundations at Abutments - Post- Seismic Conditions (Liquefied Case) Shaft Deflection in the Direction Away from the River ...... 19 Exhibit 7-5: LPILE Input Parameters for Drilled Shaft Foundations at Abutments - Post- Seismic Conditions (Liquefied Case) Shaft Deflection in the Direction Towards the River ... 20 Exhibit 7-6: Recommended Efficiency Factors (P-Multipliers) for Drilled Shaft Groups Under Lateral Loading ...... 21 Exhibit 7-7: Approach Embankment Retaining Wall Alternatives ...... 25 Exhibit 7-8: MSE Geotechnical Design Parameters ...... 26 Exhibit 7-9: MSE Configurations for Sufficient External Stability ...... 28 Exhibit 7-10: Summary of Percentage of Vehicle Classes ...... 31 Exhibit 7-11: Recommended New ACP Section for Silverton Road ...... 33

Figures Figure 1: Vicinity Map Figure 2: Site and Exploration Plan

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Figure 3: Geologic Map Figure 4: Interpretive Subsurface Profile A-A’ Figure 5: Estimated Axial Shaft Resistance 4-Foot-Diameter Drilled Shaft East Abutment Figure 6: Estimated Axial Shaft Resistance 4-Foot-Diameter Drilled Shaft West Abutment Figure 7: Additional Lateral Loading from Liquefaction Flow Failure on Drilled Shafts Figure 8: Lateral Earth Pressure Distribution on New Retaining Walls Figure 9: Global Slope Stability Results Profile A-A' Figure 10: Factored Bearing Resistance Versus Footing Width for MSE Wall Figure 11: Slope Stability Results Profile B-B’ – Static Case Figure 12: Slope Stability Results Profile B-B’ – Seismic Case Figure 13: Slope Stability Results Profile C-C’ – Static Case Figure 14: Slope Stability Results Profile C-C’ – Seismic Case

Appendices Appendix A: Field Explorations Appendix B: Laboratory Testing Important Information

CONTENTS

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ACRONYMS AC Asphalt Concrete ACP Asphalt Concrete Pavement Bgs Below ground surface Bpf Blows per foot CSZ Cascadia Subduction Zone DCP Dynamic Cone Penetrometer ESALS Equivalent Single Axle Loads HMCS Hazardous Material Corridor Study H:V Horizontal:Vertical MSE Mechanically Stabilized Earth SPT Standard Penetration Test USGS United States Geological Survey

ACRONYMS

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1 INTRODUCTION

This geotechnical engineer report summarizes our evaluation for the geotechnical components for the replacement of the Little Pudding River (Silverton Road NE) Bridge (No. 00962A) located on Silverton Road in Marion County, Oregon. This report provides geotechnical recommendations required for the design of the bridge abutments and foundations, wing walls, and embankment fill, as well as pavement recommendations for resurfacing.

Shannon & Wilson, Inc. (Shannon & Wilson), has been retained directly by Marion County, the bridge owner and designer, to provide geotechnical consulting services to support this project. This report presents the project understanding, geotechnical site characterizations including field explorations and laboratory testing, engineering analyses performed, and geotechnical recommendations for the bridge design, as well as construction considerations for this project.

2 PROJECT UNDERSTANDING

2.1 Site Description

The site encompasses an area approximately 500 feet in length on Silverton Road NE approximately 1.2 miles east of the Salem Metropolitan Statistical Area, as shown in Figure 1. The site is a paved two lane rural highway including a small bridge that spans the Little Pudding River, which flows generally north to meet the larger Pudding River west of Mt. Angel.

There is a slight horizontal curve at the location of the current bridge. There is an existing driveway on the north side of Silverton Road NE approximately 40 feet east of the existing bridge and another driveway on the north side of the roadway approximately 150 feet west of the existing bridge.

The west abutment leading up to the bridge consists of an approximate 8- to 10-foot embankment which is heavily overgrown with blackberries. The east abutment consists of an approximate 5- to 12-foot embankment which immediately leads into a small roadcut

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2- to 4-feet with drainage ditches on both sides of the road. The cuts are approximate 1H:1V slopes, heavily vegetated with grass and blackberries. On the east side of the bridge and along the north portion of the roadway, there is a small slope which leads down to the Little Pudding River. Utility poles with overhead power and telecommunications lines border the southern edge of the roadway through the site.

2.2 Project Description

This project will involve the complete replacement of the existing 37.5 feet wide and 103 feet long bridge. The bridge was built in 1922, widened in 1948, and is limited to an operating rating of 26 tons, with no overloads permitted. The existing bridge’s structural deficiency interferes with Silverton Road’s position as a major freight route and designation as a strategic freight route in Marion County’s Rural Transportation System Plan.

The new bridge is proposed to be 65.67 feet wide by 133 feet long single span structure which includes, 12-foot wide travel lanes, 8-foot wide shoulders, ODOT standard bridge rails, and will also include additional width to accommodate future roadway widening. In addition, the county is planning to raise the roadway profile at the bridge location as much as 5 to 6 feet to improve the vertical curvature through this stretch of roadway.

Design loads for the abutments were provided by the engineers at Marion County. We understand that each abutment will be subjected to unfactored live loads of 636 kips and unfactored dead loads of 2,471 kips. Applying Strength I limit state factors, the factored loads are 1,112 kips live load and 2,853 kips dead load. Each bridge abutment will be founded on five 4-foot-diameter drilled shafts that frame into a pile cap. The pile cap will have a depth below finished grade of 15.75 feet. The following recommendations are based on estimated factored Service I and Strength I limit state loads of 621 kips and 793 kips per shaft, respectively.

Each abutment pile cap will be a retaining wall. The approach embankments will also have retaining walls which will be constructed using MSE walls. These approach embankment walls will extend from each side of each abutment to assist with matching the new fill with existing grades. The southwest retaining wall will be approximately 14 feet tall and will extend longitudinally 175 feet. The northwest retaining wall will be approximately 16 feet tall and will extend longitudinally 146 feet. The southeast retaining wall will be approximately 19 feet tall and will extend longitudinally 35 feet. The northeast retaining wall will be approximately 9.2 feet and will extend 35 feet longitudinally. The heights of each of these retaining walls will shorten in height away from the bridge end bents.

The abutment retaining walls will be designed for a Factor of Safety of 1.5 for static, 1.1 for seismic, and 1.1 for post-seismic global stability cases. The approach embankment retaining

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walls will be designed for a Factor of Safety of 1.5 for static and 1.1 for seismic global stability cases. The approach embankment retaining walls will not be designed for the post- seismic liquefaction case. We understand that the approach embankment retaining walls’ design criteria is less than ODOT requirements; however, Marion County has approved this deviation in the design criteria for these four retaining walls.

The new bridge will lie on a vertical curve with the high point corresponding with the top of the bridge deck. This will raise the grade on either side of the bridge, requiring the construction of approach embankments to be approximately five feet higher than the current roadway at the west abutment and approximately six feet higher than the current roadway at the east abutment.

We understand that the design flood elevation will be +149.2 feet (50-year) and +149.7 feet (100-year), and the Ordinary High Water will be elevation +145.2 feet.

Once completed, the entire new bridge and approaches will be repaved.

2.3 Anticipated Construction Sequencing

We understand that Silverton Road will be temporarily closed during the summer of 2019 to allow for demolition of the existing bridge and construction of the new bridge. This closure is planned to last for approximately four months. Once the new bridge is completed, traffic along this stretch of Silverton Road can be reestablished.

2.4 Scope of Services

Shannon & Wilson is providing the geotechnical engineering consulting services for the geotechnical components of this project. The scope of services includes the following tasks:

. Site reconnaissance and development of a field exploration work plan; . Field explorations; . Laboratory testing; . Perform a Construction Material Survey for the existing bridge demolition; . Perform a Limited Phase 1 HMCS for the project corridor; . Geotechnical engineering evaluations and design, including seismic hazard analysis, drilled shafts, retaining walls, embankment fills, and pavement design; . Development of this geotechnical engineering report; . Development of a foundation data sheet; . Review of geotechnical related plans and specifications; and

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. Project management, attending project meetings, and emails and phone communications.

The scope of services was performed in general accordance with the following manuals and specifications:

. ODOT Geotechnical Design Manual (GDM), 2018; . ODOT Bridge Design & Drafting Manual (BDDM), May 2018; . ODOT Oregon Standard Specifications for Construction (OSSC), 2018; . ODOT Soil and Rock Classification Manual, 1987; . AASHTO LRFD Bridge Design Specifications, 8th Edition, 2017; and . Applicable FHWA geotechnical design guidelines.

3 GEOLOGIC AND SEISMIC SETTING

3.1 Regional Geology

The Little Pudding River Bridge site is located along the eastern side of the Willamette Valley physiographic province. The Willamette Valley is a forearc basin with a trough-like configuration brought about by uplift and tilting of the Coast Range and the Western Cascades. Bedrock underlying the Willamette Valley generally consists of Tertiary age volcanic rock, which has been overlain by sedimentary deposits (including Pleistocene Flood deposits of the Missoula Floods).

During the Ice Age of the Pleistocene epoch, enormous lakes formed behind glacial ice in western Montana. Water in the deep glacial lakes repeatedly breached the ice dam, resulting in catastrophic floods known as the Missoula Floods, which scoured across eastern Washington, were constricted in the Columbia River Gorge, and back-flooded into the Willamette Valley as far south as Eugene, creating a temporary lake.

The floods conveyed large blocks of ice, many of which contained sediment and even large boulders. After the flood waters receded back to the Columbia River Gorge and drained into to the Pacific Ocean, numerous large ice-rafted boulders (“erratics”) were left scattered across the Willamette Valley, along with a thick layer of fine-grained sediment, which settled out of the large temporary lake.

3.2 Local Geology

Geology near the site consists of late Pleistocene poorly indurated glaciofluvial clays and silts deposited by the Missoula Floods along with older alluvial deposits (Pleistocene)

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consisting of poorly to moderately indurated silt, sand, and weakly cemented conglomerate that comprise pre-Missoula Flood alluvial terrace/fan deposits along major streams (Tolan and Beeson, 1999). Figure 3 of this report presents a geologic map of the site and its surroundings.

3.3 Seismic Setting

Earthquakes in the Pacific Northwest occur largely as a result of the collision between the Juan de Fuca Plate and the North American Plate. These two tectonic plates meet along a mega thrust fault called the Cascadia Subduction Zone (CSZ). The CSZ runs approximately parallel to the coastline from northern California to southern British Columbia. The compressional forces that exist between these two colliding plates cause the denser oceanic plate to descend, or subduct, beneath the continental plate. This process leads to volcanism and contortion and faulting of both crustal plates throughout much of the western regions of southern British Columbia, Washington, Oregon, and northern California. Stress built up between the colliding plates is periodically relieved through great earthquakes at the plate interface (CSZ) (Goldfinger and Others, 2012).

Within our present understanding of the regional tectonic framework and historical seismicity, three broad earthquake sources have been identified. These three types of earthquakes and their maximum plausible magnitudes are as follows:

. Subduction Zone Interface Earthquakes originate along the CSZ, which is located approximately 25 miles beneath the coastline. Paleoseismic evidence and historic tsunami studies indicate that the most recent subduction zone thrust fault event occurred in 1700, probably ruptured the full length of the CSZ, and may have reached magnitude 9. . Deep-Focus, Intraplate Earthquakes originate from within the subducting Juan de Fuca oceanic plate as a result of the downward bending and contortion of the plate in the CSZ. These earthquakes typically occur at a depth of 28 to 38 miles. Such events could be as large as magnitude 7.5. Examples of this type of earthquake include the 1949 magnitude 7.1 Olympia earthquake, the 1965 magnitude 6.5 earthquake between Tacoma and Seattle, and the 2001 magnitude 6.8 Nisqually earthquake. The highest rates of CSZ intraslab activity area occur beneath the Puget Sound area, with much lower rates observed beneath western Oregon. . Shallow-Focus Crustal Earthquakes are typically located within the upper 12 miles of the continental crust. The relative plate movements along the CSZ cause not only east- west compressive strain but dextral shear, clockwise rotation, and north-south compression of the leading edge of the North American Plate (Wells and Others, 1998), which is the cause of much of the shallow crustal seismicity of engineering significance in region. The largest known crustal earthquake in the Pacific Northwest is the 1872 North Cascades earthquake with an estimated magnitude of about 7. Other examples

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include the 1993 magnitude 5.6 Scotts Mill earthquake and the 1993 magnitude 6 Klamath Falls earthquake.

Shallow crustal faults and folds throughout Oregon and Washington have been located and characterized by the USGS. Mapped fault locations and detailed descriptions can be found in the USGS Quaternary Fault and Fold Database (USGS, 2015). The database defines four categories of faults, Classes A through D, based on evidence of tectonic movement known or presumed to be associated with large earthquakes during Quaternary time (within the last 1.8 million years). For Class A and B faults, there is associated geologic evidence that demonstrates the existence of Quaternary deformation. Therefore, the faults are correlated to a higher potential for earthquake generation. Faults defined as Class B exhibit equivocal geologic evidence of Quaternary deformation or may not extend deep enough to be considered a source of significant earthquakes.

According to the USGS Fault and Fold database, there are eight Class A fault segments within approximately 30 miles of the project site. Their names, general locations relative to the site, and the time since their most recent deformation are summarized in Table 1. The surface trace of the CSZ itself is approximately 124 miles west of the site, with a slip rate greater than 5 millimeters (0.2 inches) per year and the most recent deformation occurring about 300 years ago (Personius and Nelson, 2006). Exhibit 3-1: USGS Class A Quaternary Faults within an Approximate 30-Mile Radius of the Project Site

Approximate Distance Time Since and Direction from Last Fault Name USGS Class Length Project Site Slip Rate Deformation Waldo Hills Fault A 7 miles 4.7 miles S-SW <0.2 mm/yr <1.6 Ma Mount Angel Fault A 19 miles 8.8 miles NE <0.2 mm/yr <15 ka Salem-Eola Hills A 20 miles 10.2 miles W-SW <0.2 mm/yr <1.6 Ma homocline Mill Creek Fault A 11 miles 11.2 miles S-SW <0.2 mm/yr <1.6 Ma Canby-Molalla Fault A 31 miles 20.6 miles NE <0.2 mm/yr <15 ka Newberg Fault A 3.1 miles 20.9 miles N-NW <0.2 mm/yr <1.6 Ma Gales Creek Fault Zone A 45.4 miles 27.5 miles N-NW <0.2 mm/yr <1.6 Ma Owl Creek Fault A 9 miles 29.4 miles SW <0.2 mm/yr <750 ka

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4 FIELD EXPLORATION AND LABORATORY TESTING

4.1 Geotechnical Exploration

4.1.1 Borehole and Sampling

Shannon &Wilson explored subsurface conditions at the project site with four geotechnical borings, designated B-1 through B-4, which included DCP tests for each boring. Borings B-1 and B-2 are located on the west side of the bridge, while borings B-3 and B-4, are located on the east side.

All boring locations and elevations were surveyed by Marion County. Surveyed coordinates are provided on the Drill Logs in Appendix A, and locations are shown on the Site and Exploration Plan, Figure 2. Appendix A describes the techniques used to advance and sample the borings and presents logs of the materials encountered during drilling. DCP test procedures and data are also presented.

The borings were drilled November 21 through November 29, 2016, using a CME-75, provided and operated by Western States Soil Conservation, Inc. (Western States), of Hubbard, Oregon. Samples were taken at 2.5 foot intervals for the first 10 feet and then at five foot intervals to the final depth of the borehole by driving a split spoon sampler. Sampling followed the procedures (ASTM D1586) for the Standard Penetration Test (SPT), which yields an in situ driving resistance index value (N-value) measured in blows per foot (bpf).

Shannon & Wilson geology staff were on site during drilling to locate the borings, observe drilling, collect samples, and maintain logs of the materials encountered. Summary logs of borings are presented in Figures A1 through A4 in Appendix A. Material descriptions and interfaces on the logs are interpretive, and actual changes may be gradual. Materials encountered in these boreholes were described and identified visually in the field in general accordance with the Oregon Department of Transportation (ODOT) Soil and Rock Classification Manual (ODOT, 1987).

4.1.2 Dynamic Cone Penetration Test

Pavement subgrade testing was conducted in all borings using a Dynamic Cone Penetrometer (DCP) test. The tests were conducted prior to drilling through the test interval. The DCP is a device widely used to determine in situ strength properties of base materials and subgrade soils. The four main components of the DCP include the cone, rod, anvil, and hammer. The cone is attached to one end of the DCP rod while the anvil and hammer are attached to the other end. Energy is applied to the cone tip through the rod by

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dropping the 17.64-pound hammer a distance of 22.6 inches against the anvil. The diameter of the cone is 0.16 inches larger than the rod to ensure that only tip resistance is measured. The number of blows required to advance the cone into the subsurface materials is recorded.

The DCP index is the ratio of the depth of penetration to the number of blows of the hammer. This can be correlated to a variety of material properties, including CBR and Resilient Modulus, which are common parameters used in pavement design. DCP testing was performed and documented by Shannon & Wilson field personnel. The DCP test data is presented in Appendix A in Figures A5 through A8.

4.2 Laboratory Testing

After the field explorations were completed, the samples were reviewed, and some were selected for additional laboratory testing to assist in the selection of representative engineering properties for the major soil units at the site. The soil testing program included moisture content analyses and Atterberg limits determinations. These laboratory tests were performed by Northwest Testing, Inc., of Wilsonville, Oregon. Corrosivity testing was also performed on three samples for parameters related to corrosivity potential by Specialty Analytical of Clackamas, Oregon.

The results of the Atterberg limit tests, sieve analysis tests, and corrosivity tests are shown in Appendix B.

Some of the laboratory testing data such as the moisture content results are included on the drill logs included in Appendix A. The entire set of laboratory data is presented in Appendix B.

5 SUBSURFACE CONDITIONS

The explorations were performed to evaluate geotechnical conditions for the design of the bridge abutments and foundations, retaining walls, and embankment fill, as well as to provide data for pavement design recommendations. Our observations are specific to the locations and depths noted on the logs and may not be applicable to all areas of the site.

5.1 Subsurface Soil Units

The soil units encountered at the project site generally consist of Fill at the surface overlying Missoula Flood Deposits - Fine Facies, which overlie the Pleistocene Sand and Gravel and extends to the limits of the depths explored. These units are represented stratigraphically on the geologic subsurface profile in Figure 4. Regarding the subsurface profile, it must be

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noted that no amount of explorations or testing can precisely predict the characteristics, quality, or distribution of subsurface and site conditions. Potential variation includes, but is not limited to the following:

. The conditions between and below explorations may be different. . The passage of time or intervening causes (natural and manmade) may result in changes to site and subsurface conditions. . Groundwater levels and flow directions may fluctuate due to seasonal variations. . Penetration test results in gravelly soils may be unrealistic. Actual soil density may be lower than estimated if the test was performed on a gravel or cobble.

If conditions different from those described herein are encountered during construction, we should be consulted to review our description of the subsurface conditions and confirm or reconsider our conclusions and recommendations as necessary.

5.1.1 Fill

The fill encountered at the site was likely placed during the construction of embankments for the original bridge at the Little Pudding River. The fill is typically silt with some sand or with some gravel. It is very soft to medium stiff. SPT N-values in the fill ranged from 0 to 28 bpf with an average of 9 bpf.

5.1.2 Missoula Flood Deposits – Fine Facies

The Missoula Flood Deposits – Fine Facies, also referred to as Fine-Grained Missoula Flood Deposits, underlie the fill at both abutments. This unit is composed of soft to medium stiff clay, silt, and sandy silts. The clays typically have medium plasticity, exhibit slight iron oxide staining, and are micaceous. The silts and sandy silts are typically non-plastic to low plasticity. Trace organics are present in the clays in most of the borings. SPT N-values in the Missoula Flood Deposits ranged from 0 to 33 bpf with an average of 8 bpf.

5.1.3 Pleistocene Sand and Gravel

Pre-Missoula Flood alluvium deposits were encountered below the Missoula Flood Deposits unit, which we designated Pleistocene Sand and Gravel based on mapping by Tolan and Beeson, 1999. The Pleistocene Sand and Gravel are generally thought to have been deposited from the east, in medium to high energy fluvial environments including large and small stream valleys and basins. The unit includes medium dense to very dense, silty sand, sand, gravel, sandy gravel, silty sandy gravel, and clayey gravel. Fines within the unit were generally nonplastic to medium plasticity. SPT N-values in the fill ranged from 38 bpf to

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refusal. 23 out of 33 SPT N-values performed in the Pleistocene Sand and Gravel met refusal, where 50 hammer blows were required to drive the sampler 6-inches or less.

5.2 Groundwater

Groundwater levels were estimated during drilling, but the exact location is somewhat difficult to ascertain based on the use of mud-rotary drilling techniques, which required switching to the mud rotary system prior to encountering groundwater. Based on subsurface conditions and the conditions encountered during drilling, groundwater was approximated to be at a depth of 10 feet below ground surface (bgs) at boring B-1, 19 feet bgs at boring B-2, 17.5 feet at boring B-3, and 10 feet bgs at boring B-4.

Groundwater levels may vary with precipitation, the time of year, and/or other factors. Generally, groundwater highs occur at the end of the wet season in late spring or early summer, and groundwater lows occur toward the end of the dry season in the fall. We understand that the design flood elevation will be +149.2 feet (50 year) and +149.7 feet (100 year), and the Ordinary High Water will be elevation +145.2 feet.

6 SITE-SPECIFIC SEISMIC HAZARD EVALUATION

A site specific seismic hazard assessment was conducted for the new bridge site in order to develop seismic parameters for the different design criteria and to assess the geotechnical seismic hazards such as liquefaction, lateral spreading, and seismic slope stability. The evaluation was performed in accordance with the ODOT GDM (2018b).

6.1 Site Class

The site class was estimated using the information collected during the exploratory boring program. Borings B-1 through B-4 provide data to assess the seismic site class using the uncorrected blow counts. The profile was consistent at each boring, showing Fill over Fine- Grained Missoula Flood Deposits with deep very dense gravels below. Based on the soil information available, we conclude that the soils would be representative of Site Class E.

While the site class is used in deriving the “life safety” criteria, the value Vs30, the average shear wave velocity in the upper 30 meters, is required to derive the “operational” criteria deterministic response spectra. The Vs30 was estimated by assigning representative shear wave velocity values to each of the three major stratigraphic layers. For the new bridge site, we estimate a Vs30 of 150 m/sec.

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6.2 Seismic Parameters – “Life Safety” Criteria

The seismic parameters for the “life safety” criteria were derived using Oregon Department of Transportation (ODOT) Bridge Section’s Excel application, ODOT_ARS.v.2014.16, which uses the three-point curve method. This excel application is available through ODOT’s web portal (ODOT, 2018d). The seismic parameters for this site are presented in Exhibit 6-1, below. Exhibit 6-1: "Life Safety" Criteria Seismic Parameters

Parameter Value Site Class E PGA (g) 0.253 Ss (g) 0.544 S1 (g) 0.216 Fpga 1.741 Fa 1.630 Fv 3.219 As (Fpga*PGA) 0.440 SDS (Fa*Ss) 0.886 SD1 (Fv*S1) 0.696 SDC D

6.3 Deterministic Response Spectra – “Operational” Criteria

The “operational” criteria is defined as a full rupture of CSZ Earthquake. The associated hazard is available through maps on the ODOT Bridge Section website; however, this hazard is a deterministic event. Therefore, a deterministic response spectrum is most representative. The deterministic response spectrum for the CSZ Earthquake was generated by using the web-based application developed by Portland State University and available on the ODOT Bridge Section website (ODOT, 2018d). A Vs30 of 200 m/sec was used to produce the design spectrum presented in Exhibit 6-2, below. This seismic design tool can only compute a minimum value for Vs30 of 200 m/s, and, therefore, this shear wave velocity was used and not the estimated value of VS30 of 150 m/s.

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Exhibit 6-2: "Operational" Criteria Acceleration Response Spectrum (VS30 = 200 m/s)

Period, T (sec) Spectral Acceleration, Sa(g) 0.00 0.206 0.05 0.202 0.10 0.282 0.15 0.355 0.20 0.397 0.25 0.432 0.30 0.468 0.40 0.502 0.50 0.505 0.60 0.483 0.70 0.477 0.80 0.466 1.00 0.407 1.50 0.289 2.00 0.218 2.50 0.175 3.00 0.142

6.4 Liquefaction and Its Consequences

Liquefaction is a phenomenon in which excess pore pressure of loose to medium-dense, saturated, granular soils increases during ground shaking. The increase in excess pore pressure results in a reduction of soil shear strength and a potentially quicksand-like condition.

Portions of the Fine-Grained Missoula Flood Deposits found in all borings, B-1 through B-4, at the new bridge site have been found to be susceptible to liquefaction based on liquefaction trigger analyses (Youd et al, 2001 and Boulanger & Idriss, 2014). In areas where this soil unit was found to be either low plasticity or non-plastic and below the ground water table, the blowcounts of this unit were typically below the liquefaction threshold.

In boring B-1, Fine-Grained Missoula Flood Deposits between 28 feet and 39 feet bgs were found to liquefy. These materials are described as silt with trace sand, non-plastic, and loose to very loose. The average blow counts in this zone is six bpf.

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In boring B-2, Fine-Grained Missoula Flood Deposits between 37.5 feet and 41.5 feet bgs were found to liquefy. These materials are described as sandy silt with trace gravel, low plasticity, and stiff. The blowcount for this sample is 10 bpf.

In boring B-3, Fine-Grained Missoula Flood Deposits between 17.5 feet and 33.0 feet bgs were found to liquefy. These materials are described as silt and silt with some sand, low plasticity to non-plastic, and soft to medium stiff. The average blowcount for the sample from this zone is 7 bpf.

In boring B-4, Fine-Grained Missoula Flood Deposits between 9.5 feet and 32.5 feet bgs were found to liquefy. These materials are described as silt with trace sand and silt with some sand, non-plastic, and loose to medium dense and stiff. The average blowcount for the sample from this zone is 11 bpf.

6.4.1 Liquefaction-Induced Settlement

Liquefaction-induced settlements at the ground surface are estimated to be on the order of three to five inches along the east approach embankments. Liquefaction-induced settlements at the ground surface are estimated to be on the order of one to three inches along the west approach embankments. Liquefaction-induced settlements will affect the retaining walls for the approach embankments. These settlements will not be transferred to the bridge structure because it will be founded on drilled shafts into the non-liquefiable gravels below the Missoula Flood Deposits. There will be downdrag imposed on the drilled shafts, which will be discussed in more detail below.

6.4.2 Liquefaction-Induced Slope Instability

Liquefaction of soils can drastically alter their engineering properties by reducing their strength to a residual strength value. The steep slopes at the east and west abutments were found to have factors of safety of less than 1.0 during the post-seismic case, using liquefied residual shear strength soil properties. This indicates that there is a risk of slope instability that may be expressed as flow failure or complete loss of the slope.

To protect the bridge structure from this type of slope failure, an integrated bridge and abutment system is used. This system uses a rigid moment and shear connection between the bridge deck and the abutment pile caps in addition to drilled shafts foundations for the abutment pile caps. The forces exerted onto the pile cap and drilled shafts are presented below.

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The consequence of liquefaction-induced slope stability will impact both the east and west the approach embankments and retaining walls, the bridge abutment retaining walls, and the bridge abutment foundations. Specific effects are described below.

7 ENGINEERING CONCLUSIONS AND RECOMMENDATIONS

The main components of this bridge project will be the abutment and their foundations. The foundations at each abutment will consist of five 4-foot diameter drilled shafts. The axial capacity of the drilled shafts is presented below along with anticipated downdrag loads in both the static case and the post-seismic case. Additionally, the lateral performance of these drilled shafts can be modeled using the L-Pile parameters. Lastly, the additional forces imposed on the drilled shafts due to flow failure during liquefied conditions is presented with discussion on how it will be applied.

There will be two abutment retaining walls located at each bridge abutment. These retaining walls will be resisted by both the drilled shafts and an integrated bridge superstructure. The lateral earth pressures applied to these abutment walls in the static and seismic case are provided. Furthermore, the lateral loading on the abutments during the post-seismic case is also provided.

There will be four approach embankment retaining walls. These walls will be constructed as MSE walls. The design parameters which can be used by the designing contractor are provided as well as the minimum required reinforced length based on the global stability analyses.

The approach embankments will be constructed by placing up to 6 feet of new fill. Due to the compressibility of the subsurface soils, this embankment may experience some long- term settlement which will require special care and sequencing of the final pavement placement. Lastly, this section will present our recommendations on the new pavement for this bridge replacement and approaches.

7.1 Foundation Types and Alternatives

The selection of an appropriate foundation system for the proposed bridge structure is dependent upon several factors, including foundation capacities, performance of the bridge during liquefaction, tolerance to total and differential settlement resulting from static loads, and construction considerations. Based on the explored subsurface conditions, design loads, slope stability in the post-seismic (liquefied) case, and anticipated construction sequence, we recommend drilled shafts as the most economical and feasible foundation

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system for this bridge. A comparison between drilled shafts and driven pipe piles is included below in Exhibit 7-1. Exhibit 7-1: Bridge Abutment Foundation Alternatives

Alternative Description Advantages Disadvantages Drilled - Construct drilled shafts - Can penetrate the - More expensive than driven pipe piles. Shafts at the abutment locations Missoula Flood Deposits - Some risk in drilling through the Pleistocene and connect them with a and the Pleistocene Sand and Gravel due to potential presence pile cap. Sand and Gravel. of cobbles. - Structural capacity and stiffness in lateral loading is adequate to achieve performance criteria when large lateral forces are applied to deep foundation elements during the post-seismic liquefaction case. Driven Pipe - Install driven pipe piles at - Can easily penetrate - Risk of premature refusal in the Pleistocene Piles the abutment locations the Missoula Flood Sand and Gravel. and connect them with a Deposits. - Structural capacity and stiffness in lateral pile cap. - More cost-effective than loading inadequate due to large forces drilled shafts. applied to deep foundation elements during - Faster installation than the post-seismic liquefaction case. drilled shafts.

We considered spread footings at the proposed bridge abutments. Spread footings are typically a cost-effective option. However, for this site, there are some specific construction challenges that restrict their use. Due to the presence of the high plasticity clays directly below the fill at either bridge abutment and the presence of liquefiable soils interbedded in the Fine-Grained Missoula Flood Deposits, spread footings would need to be placed on the Pleistocene Gravel. This would require excavations to depths of at over 40 feet, therefore making this option infeasible. Furthermore, the performance of the spread footings would still be inadequate during the post-seismic liquefaction case.

7.2 Drilled Shafts for Abutment Foundations

The following sections provide our recommendations for axial and lateral resistance of the 4-foot-diameter drilled shafts at the east and west abutments. We understand that five drilled shafts will be used at each abutment. The drilled shafts will frame into a pile cap that will extend to a depth of 15.75 feet from finished grade. We designed the drilled shafts to resist axial loads by both side friction and end bearing resistances.

Boring B-3 was advanced near the location of the east abutment. Boring B-2 was advanced at the approximate location of the west abutment. For design, we assumed subsurface

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conditions at drilled shafts for the west and east abutment are those encountered at Borings B-2 and B-3, respectively.

7.2.1 Drilled Shaft Axial Resistance

We performed axial resistance evaluation in general accordance with the AASHTO LRFD (2017). We evaluated axial resistance for service, strength, and extreme event limit states. The analyses were based on the subsurface conditions encountered in the nearby project borings and our experience with similar soil and project conditions. We estimated unit side and tip resistance values based on the average SPT values (N-values) within each unit, laboratory tests, load tests in similar soil conditions from other projects, and our experience.

Our axial resistance analyses results are presented for the east and the west abutments in Figures 5 and 6, respectively. These results are presented as plots of nominal and factored axial resistance versus depth for service, strength, and extreme event limit states. Recommended resistance factors for each limit state in compression and uplift are provided in the notes section of the figure. Recommended resistance factor values could be increased if a load test program is implemented for the project.

Estimated drilled shaft length and tip elevation, based on the provided factored design loads for the Strength and Service limit states at each abutment, are summarized in Exhibit 7-2, below. The estimated shaft length and tip elevation provided are based on axial capacity requirements only and do not consider uplift or lateral capacity requirements, such as the embedment depth required to develop lateral shaft fixity. Exhibit 7-2: Estimated Drilled Shaft Length and Compressive Resistance

Factored Axial Compressive Factored Uplift Resistance (kips) Resistance (kips)

Top of Estimated Estimated Service Shaft Shaft Shaft Tip Limit Extreme Extreme Elevation Length1 Elevation Strength (1 in of Event Strength Event Location (feet) (feet) (feet) Limit settlement) Limit Limit Limit East +160 47 +113 800 1007 1435 285 507 Abutment West +158 48 +110 805 1014 1364 288 513 Abutment NOTE: 1 Estimated shaft length is taken as the distance between the top of shaft and estimated shaft tip elevation.

The estimated axial resistance assumes the shafts are spaced at least three shaft diameters apart (3D), measured center to center, and in a single row. We understand that the abutments will be supported by a single row of shafts, spaced at approximately 13 feet

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center to center (~3.3D); therefore, a reduction is not required for axial shaft group effects, as recommended by the AASHTO LRFD Section 10.8.3.6.

7.2.2 Downdrag on the Drilled Shafts

The drilled shaft will be subjected to downdrag loads in both the static and post-seismic cases. In the static case, the downdrag will be caused by settlement of the Fine-Grained Missoula Flood Deposits due to the placement of new fill for the approach embankments. The maximum downdrag location will be in the lower portion of the Fine-Grained Missoula Flood Deposits, approximately 27 feet below finished roadway grade. The value of static unfactored downdrag load will be 90 kips. The load factors for downdrag for the Strength limit states are presented in Table 3.4.1-2 in AASHTO (2017). The load factor for downdrag for the Service limit states are presented in Table 3.4.1-1 in AASHTO (2017).

The soils at each abutment have been found to be susceptible to liquefaction. If liquefaction was to occur, downdrag will be imposed on the drilled shafts. At the east abutment, the downdrag load will be approximately 120 kips and will be maximum at a depth of 39 feet below finished grade. At the west abutment, the downdrag load will be approximately 240 kips and will be maximum at a depth of 46.5 feet below finished grade. The load factor for downdrag for the Extreme limit states should be taken as 1.00 per Table 3.4.1-1 in AASHTO (2017).

7.2.3 Drilled Shaft Lateral Resistance

The drilled shaft foundations will be subjected to lateral loads resulting from live, wind, and seismic loading. Additionally, in the post-seismic (liquefied) slope stability case for the abutment slopes, flow failure forces will exert lateral loads onto the drilled shafts. We understand that the bridge will be designed utilizing integrated abutment and bridge deck. The integrated bridge abutments will transfer lateral load through the bridge superstructure into the opposite bridge abutment. The drilled shafts will resist the lateral forces imposed by the seismic lateral loads and the additional post-seismic loading by both the bridge superstructure and embedment into non-liquefied soils.

We understand that the laterally loaded shaft analyses will be performed with the aid of the computer program LPILE. Geotechnical input parameters for the LPILE computer model are provided in Exhibit 7-3, below. These values are appropriate for use in the static and seismic cases.

For the post-seismic case, where some layers of non-plastic and low plasticity silts of the Fine-Grained Missoula Flood Deposits have liquefied, Exhibit 7-4 and Exhibit 7-5 contain those LPILE parameters. In the post-seismic case, the direction of loading is considered.

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Exhibit 7-4 should be used for deflection of the drilled shafts away from the river and Exhibit 7-5 should be used for deflection of the drilled shafts towards the river. Exhibit 7-3: LPILE Input Parameters for Drilled Shaft Foundations at Abutments - Static & Seismic Conditions

Approximate Soil p-y Depth1 (feet) Effective Friction Modulus p-y Unit Weight Angle k Abutment Top Bottom Soil Description Model (pcf)2 (deg)3 (pci)4 Missoula Flood Sand 0 11 105 32 18 Deposits - Fine Grained (Reese) Missoula Flood Sand 11 27 43 32 15 East Deposits - Fine Grained (Reese) Abutment Missoula Flood Sand (Boring B-3) 27 36.5 53 33 70 Deposits - Fine Grained (Reese) Pleistocene Sand & Sand 36.5 Tip 68 38 125 Gravel (Reese) Missoula Flood Sand 0 9 105 32 18 Deposits - Fine Grained (Reese) West Missoula Flood Sand Abutment 9 34.5 43 32 15 Deposits - Fine Grained (Reese) (Boring B-2) Pleistocene Sand & Sand 34.5 Tip 68 38 125 Gravel (Reese)

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Exhibit 7-4: LPILE Input Parameters for Drilled Shaft Foundations at Abutments - Post-Seismic Conditions (Liquefied Case) Shaft Deflection in the Direction Away from the River

Approximate Soil Depth1 (feet) Effective p-y Unit Friction Modulus Strain Undrained Soil p-y Weight Angle k Factor Cohesion Abutment Top Bottom Description Model (pcf)2 (deg)3 (pci)4 e50 (psi) Missoula Sand Flood 0 11 (Rees 105 32 18 - - Deposits - e) Fine Grained Missoula Soft Flood Clay 11 27 43 - - 0.05 2 East Deposits - (Matlo Abutment Fine Grained ck) (Boring B- Missoula 3) Sand Flood 27 36.5 (Rees 53 33 70 - - Deposits - e) Fine Grained Pleistocene Sand 36.5 Tip Sand & (Rees 68 38 125 - - Gravel e) Missoula Sand Flood 0 9 (Rees 105 32 18 - - Deposits - e) Fine Grained Missoula Sand Flood 9 30 (Rees 43 32 15 - - Deposits - West e) Abutment Fine Grained (Boring B- Missoula Soft 2) Flood Clay 30 34.5 Deposits - 43 - 0.05 3.4 (Matlo Fine Grained ck) (liquefied) Pleistocene Sand 34.5 Tip Sand & (Rees 68 38 125 Gravel e)

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Exhibit 7-5: LPILE Input Parameters for Drilled Shaft Foundations at Abutments - Post-Seismic Conditions (Liquefied Case) Shaft Deflection in the Direction Towards the River

Approximate Soil p-y Depth1 (feet) Effective Friction Modulus p-y Unit Weight Angle k Abutment Top Bottom Soil Description Model (pcf)2 (deg)3 (pci)4 Missoula Flood Sand 0 11 105 0 18 Deposits - Fine Grained (Reese) Missoula Flood Sand 11 27 43 0 15 East Deposits - Fine Grained (Reese) Abutment Missoula Flood Sand (Boring B-3) 27 36.5 53 33 70 Deposits - Fine Grained (Reese) Pleistocene Sand & Sand 36.5 Tip 68 38 125 Gravel (Reese) Missoula Flood Sand 0 9 105 0 18 Deposits - Fine Grained (Reese) West Missoula Flood Sand Abutment 9 34.5 43 0 15 Deposits - Fine Grained (Reese) (Boring B-2) Pleistocene Sand & Sand 34.5 Tip 68 38 125 Gravel (Reese) NOTES: 1 Based on depth below the bottom of the pile cap 2 pcf = pounds per cubic foot 3 deg = degrees 4 pci = pounds per cubic inch

The estimated lateral resistance parameters presented in Exhibit 7-3 through 7-5 are recommended for drilled shafts with center-to-center spacing greater than 5D (a distance that is five times the diameter of the shafts) and in a single row. For shaft spacing less than 5D, the appropriate P-Multiplier must be established and applied, as recommended by the AASHTO LRFD Section 10.7.2.4. We understand that each abutment will be supported by a single row of shafts, spaced at ~3.3D. Therefore, P-Multipliers for group effect were estimated for longitudinal and transverse loading directions to the center line of the bridge. The P-Multipliers for group effect are summarized in Exhibit 7-6, below.

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Exhibit 7-6: Recommended Efficiency Factors (P-Multipliers) for Drilled Shaft Groups Under Lateral Loading

Loading Direction1 Shaft2 P-multiplier Longitudinal All shafts 0.8 Row 1 0.8 Transverse Row 2 0.4 Row 3 and higher 0.3 NOTES: 1 To the center line of the bridge 2 Row 1 is the leading edge foundation element in the direction of loading

7.2.4 Additional Lateral Load Due to Flow Failure

The global stability analyses for the retaining walls at the bridge abutments and the slopes below them to the river indicate that the current abutment slope may experience flow failure at both abutments towards the river channel. The bridge structure will be designed to accommodate the lateral forces imposed on the bridge abutment and the drilled shaft foundations by the laterally-moving liquefied soil and crust.

This force applied to the deep foundations for the abutments due to the post-seismic liquefaction case was determined to be 30% of the total overburden pressure. This estimate of lateral force is a total unit force per linear foot of width. The resulting force is then distributed using a rectangular distribution that will extend from the bottom of the pile cap to the bottom of the lowest liquefiable layer. For the East Abutment, the depth to the bottom of the lowest liquefiable layer is 39.0 feet below finished grade. For the West Abutment, the depth to the bottom of the lowest liquefiable layer is 46.5 feet below finished grade. The resulting pressure is 0.8 kips per square foot. This pressure should be applied to three times the diameter of the drilled shafts. The pressure distribution on the drilled shaft is illustrated in Figure 7.

7.2.5 Drilled Shaft Construction Considerations

The drilled shaft installation procedures should follow the 2018 ODOT Oregon Standard Specifications for Construction (OSSC), Section 00512 (ODOT, 2018c), with appropriate project-specific provisions. The selection of equipment and procedures for constructing drilled shafts should consider shaft diameter and length and subsurface conditions. The design and performance of drilled shafts can be significantly influenced by the equipment and construction procedures used to install the shafts.

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Generally, drilled shafts are constructed by excavating a cylindrical bore to the prescribed embedment with a large-diameter auger or other drilling tool. Temporary or permanent casing is often used, depending on site conditions.

Upon completion of drilling and inspection of the shaft, a steel rebar cage is placed, and concrete is pumped into the hole to complete the drilled shaft. In our opinion, due to the possibility for instability and difficult drilling in the gravels, we recommend that the drilled shafts be constructed using fully-cased excavations. The drilled shafts should be constructed in the wet, and the casing should be advanced ahead of the auger. A vibratory hammer may be used to install the temporary casing. Due to the potential hydrostatic imbalances, drilling slurry may be required to avoid soil loss around the casing. The casing, used to advance the excavated shaft, must be removed upon backfilling the drilled shaft when poured.

Drilled shaft contractors who participate on this project should be required to demonstrate that they have suitable equipment for this project and adequate experience in the construction of shafts with similar subsurface conditions.

7.2.5.1 Potential Obstructions

Based on our explorations, cobbles may be encountered in the Pleistocene Sand & Gravel unit where the drilled shafts will be terminated. A statement must be included in the contract special provisions alerting the contractor to potential difficulties with cobbles when installing the drilled shafts.

7.2.5.2 Shaft Quality Control

We require that a qualified representative from our firm provide full-time observation of the drilled shafts to observe the contractor’s means, methods, and equipment and to assist the drilled-shaft inspector with an understanding of the critical issues for drilled shaft construction. In addition, the design geotechnical engineer and structural engineer should make periodic visits.

We require that cross-hole sonic log (CSL) tubes be installed in each shaft and that CSL testing is performed on each shaft in accordance with ODOT OSSC (2018c) and the project special provisions.

7.3 Abutment Retaining Walls

Each abutment will be comprised of a pile cap that will extend to a depth of 15.75 feet below finished grade. These pile caps will be supported by five 4-foot-diameter drilled shafts. There will be retained soil on the embankment side of these abutment walls. Global

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stability analyses are performed, assuming that all of the soil on the creek side of the retaining wall has been removed to the top of the scour pads. Settlement, bearing capacity, and lateral sliding is not presented for the abutment retaining walls in this section as these walls are founded on drilled shafts.

In this section, the lateral earth pressures are presented. For the static and seismic case, the approach is straight forward. For the post-seismic case, the lateral earth pressures will be governed by the global stability case. In this case, the integrated bridge abutments will transfer lateral load through the bridge superstructure into the opposite bridge abutment.

7.3.1 Earth Pressures - Abutment Retaining Walls

The at-rest earth pressures are estimated for the abutment retaining walls following the guidance presented in AASHTO Section 3.11.5.2 (AASHTO, 2017). The geometry yields an active earth pressure coefficient of 0.44. A resultant calculated from the distributed active earth pressure can be placed H/3 up from the base of the wall. The active earth pressure can be evaluated as an equivalent fluid unit weight of 57 pounds per cubic foot. Additionally, the static surcharge pressure is calculated using the active earth pressure coefficient. We present these earth pressures in Figure 8. At-rest earth pressure should be used for the abutment walls because they will be restricted from displacing at the top of the wall.

To estimate the earth pressures delivered to the abutment retaining walls from surcharge loading, the surcharge can be multiplied by a factor of 0.44 and applied to the back of the wall. This is shown in Figure 8.

We estimate the seismic induced earth pressures using a horizontal acceleration of 0.44. This is the site adjusted PGA for the “life safety” criteria. The full PGA is used because we assume that the abutment walls are not free to deform. The seismic earth pressure is presented in Figure 8.

7.3.2 Global Stability - Abutment Retaining Walls

The global stability was evaluated at both abutments for static, seismic, and post-seismic liquefaction cases. For each of the abutments, the post-seismic liquefaction case produced the worst factor of safety. For the west abutment wall, the total resisting unit force required to be applied to the bridge abutment was found to be 24 kips per linear foot of width in order to achieve a factor of safety of 1.1. For the east abutment wall, the total resisting unit force required to be applied to the bridge abutment was found to be 46 kips per linear foot of width in order to achieve a factor of safety of 1.1. The analyses for the post-seismic case is presented in Figure 8. This additional 46 kips per linear foot is shown in the drilled shaft lateral forces discussed above and presented in Figure 7.

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It should be noted that these factors of safety for the post-seismic case will result in protection of the bridge structure. The slope below the abutment may experience flow failure due to liquefied soil flowing between the drilled shafts. This soil flow will affect the approach embankments. We understand that the design criteria to protect the embankment slope for the post-seismic liquefaction case is not required so long as the bridge and its foundations are shown to provide adequate performance/strength in this post-seismic case.

7.3.3 Retaining Wall Backfill Material and Drainage – Abutment Retaining Walls

Suitable drainage for walls can be provided by granular backfill material and a wall base subdrain system consisting of a 6-inch-diameter perforated or slotted drain pipe wrapped in an envelope of filter material at least 12 inches thick, confined by a separation geotextile. The filter material is specified in Section 02610.10(a) of the OSSC (ODOT, 2018c). The subdrain should be above the typical groundwater level, convey any collected seepage to the end of the wall, and daylight at low spots below the wall elevation.

7.4 Embankment Retaining Walls

There will be four new wing walls that are a part of the new bridge approach embankments. These walls will be classified as Bridge Retaining Walls, according to the ODOT GDM (2018b). The walls are required because there will be up to five to six feet of fill required to raise the roadway at the two approach embankments. There are limitations to the right-of- way available for use, which eliminates the opportunity to place embankment slopes.

7.4.1 Retaining Wall Types and Alternatives

The retaining wall types considered for use to support the approach embankments are gravity walls, cantilever soldier pile walls, and MSE walls. The advantages and disadvantages are discussed in Exhibit 7-7, below.

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Exhibit 7-7: Approach Embankment Retaining Wall Alternatives

Alternative Advantages Disadvantages - Cannot accommodate settlement of the approach embankment fill. Gravity - Cost effective. - Must be drastically widened in order to achieve Wall/Ultrablock appropriate factors of safety for static and seismic Wall - Can be constructed quickly. cases. - Poor performance in seismic as compared to other wall types. - More cost effective than Soldier Pile Wall. - Can accommodate settlement of - More expensive than Ultablock Wall. MSE Wall approach embankment fill using a two - Requires more earthwork than Ultrablock Wall. phase approach. - Good performance during seismic event. - Good performance can be designed into the wall to accommodate settlements. Cantilever - Most expensive wall type. - Does not require a two phase approach. Soldier Pile - Increased risk when installing drilled shafts for the Wall - Solider piles can be installed using soldier piles. drilled shaft equipment already mobilized to site for abutment foundations.

MSE walls appear to be the best solution. These wall types can be constructed in two phases. The first stage would be to build the MSE walls using a wire face. Once constructed, they can be monitored for settlement. When most of the settlement appears to have occurred, a second stage can be built, which would be to install a rigid facing element onto the MSE wall. These rigid elements can be precast concrete panels.

7.4.2 MSE Retaining Wall Geometry and Soil Parameters

The basic geometries of the MSE walls have been determined following the guidance in the ODOT GDM (2018b) and the geometries at the site. All walls must have a minimum of two feet embedment and the wall height is measured from the bottom of the embedment to the top of the wall. The ODOT GDM (2018b) also requires that all walls are required to have a minimum width of 0.7 times the height of the wall or 8 feet, whichever is greater. In some instances, the wall width has become wider to accommodate for adjacent slopes at the toe based on the global stability analyses. The global stability analyses of these MSE walls is presented in Section 7.4.7, below. These analyses require minimum reinforment length in excess of ODOT GDM requirements. All walls should have a bench of four feet of width in front of the wall at the toe.

Exhibit 7-8 presents the estimated design parameters of the reinforced fill, retained backfill, and the generalized foundation soil used herein for MSE design.

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Exhibit 7-8: MSE Geotechnical Design Parameters

Soil Parameter Reinforced Fill Retained Backfill Foundation Soil Unit Weight (pcf) 130 130 105 Internal Friction Angle (degrees) 34 34 32 Cohesion (psf) 0 0 100 NOTES: pcf = pounds per cubic foot psf = pounds per square foot

7.4.3 Lateral Earth Pressures - MSE Walls

The lateral earth pressures were calculated for the MSE walls. These are presented in Figure 8. The active pressures will apply for retaining structures, which are free to deflect along the face of the wall.

7.4.4 Soil Bearing Resistance - MSE Walls

The bearing resistance of the MSE abutment retaining walls were calculated using the guidance provided in AASHTO (2017) Section 10.6.3.1 and the ODOT GDM (2018b). The strength and extreme event limit state bearing resistances are obtained by selecting appropriate soil strength parameters and computing a nominal bearing pressure at which shear failure of the bearing soil would likely occur. The nominal bearing resistance multiplied by the appropriate resistance factor gives the factored bearing resistance. The results of our bearing capacity analysis are presented in Figure 10.

We recommend that the wall designer check the bearing for both the Strength Limit State and Extreme Event Limit States and use a resistance factor of 0.65 and 1.0, respectively, based on AASHTO (2017) Table 11.5.7-1.

7.4.5 Settlement - MSE Walls

Based on the subsurface stratigraphy encountered in the geotechnical borings, the MSE retaining walls will likely bear directly on the clays of the Fine-Grained Missoula Flood Deposits. This unit will be slow to drain in some portions of the unit where the soil has higher plasticity. Slow draining soils will result in some long-term settlements. Due to the uncertainty in the properties of the clay unit, we estimate the long-term settlement of this retaining wall to fall within a range of 5 inches to 10 inches in areas where there will be up to 12 feet of fill placed. We anticipate that 90 percent of settlement will occur between one to three months.

We anticipate that the settlement at the face of the retaining walls will be larger than the settlement experienced in the center of the embankment because there will be twice as much

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fill placed at the face of the MSE walls due to the existing contours at site. This will lead to some differential settlements between the rear and the face of the MSE wall. In general, MSE walls can accommodate differential settlements as long as they do not have a rigid face attached.

The MSE walls must be constructed in two phases to prevent damage to the face. The first phase should use a flexible wire facing for the MSE walls. Once the settlement has concluded, a rigid, permanent face should then be applied to the MSE walls.

7.4.6 Lateral Sliding Resistance – MSE Walls

The sliding stability of the MSE walls must be evaluated by the wall designer. A check must be performed at the bottom of the wall facing and at the interface between the soil and reinforcement for the lowest reinforcement layer.

Additionally, the coefficient of sliding friction at the base of the reinforced soil mass shall be determined using the friction angle of the foundation soil or reinforced fill soil. In this case, the reinforced fill soil is assumed to have a friction angle of 34 degrees per ODOT GDM (2018b) Section 15.6. The foundation soil friction angle is assumed to be 32 degrees from the SPT N values. The lower of these two should be used for this analysis.

The nominal sliding resistance coefficient was calculated to be 0.62 for analyses of the MSE wall to soil interface. For analysis of sliding resistance in the Strength Limit State and the Extreme Event Limit States, we recommend a resistance factor of 1.0 is used based on AASHTO (2017) Table 11.5.7-1. The wall designer should check lateral sliding for the Strength Limit State and Extreme Event Limit States.

7.4.7 Global Stability – MSE Walls

We evaluated the global stability of the four MSE retaining walls for the embankments at perpendicular cross sections which represented their critical geometries and slopes beneath the toe. These critical sections were taken at a location approximately 10 feet from the centerline of the bridge abutments. These cross sections are B-B’ for the Northeast and Southeast retaining walls and C-C’ for the Northwest and Southwest retaining walls. The locations of these cross sections are shown in Figure 2. For each wall, we assume two feet of embedment of the toe and a bench at the base of each wall if the terrain was not already flat.

The global stability analyses were performed using the computer program SLOPE/W 2016. This program employs the Spencer method for rotational and irregular surface failure mechanisms. Additionally, a surcharge of 250 psf was placed along the ground surface at the top of the wall. The analysis results are presented in Figure 11 through 14. The static FS

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for the approach embankment retaining walls are estimated to be 1.5 or greater. The seismic FS for the approach embankment retaining walls are estimated to be 1.1 or greater.

The above analyses indicate that the abutment retaining wall geometry has an adequate FS for use as highway retaining wall for the static and seismic case. The design criteria requirement of a factor of safety for the seismic case and the post-seismic case of 1.1, per the ODOT GDM (2018b) has been waived for this project by Marion County. This decision was made because of the large expense to mitigate flow failure along the slope of the Little Pudding River. The four embankment retaining walls thus have compatible performance objectives.

Exhibit 7-9, below, indicates the wall geometry and the associated minimum reinforcement length as a fraction of wall height. In addition to this minimum requirement, the ODOT GDM (2018b) requires a minimum reinforcement length of 8 feet as well. Exhibit 7-9: MSE Configurations for Sufficient External Stability

Minimum Reinforcement Minimum Reinforcement Maximum Wall Height Length at Maximum Wall Length as a Fraction of Wall Designation (ft) Height (ft) Wall Height Northeast Retaining Wall 9.2 8.0 0.7 H Southeast Retaining Wall 19.0 22.8 1.1 H Northwest Retaining Wall 16.0 13.0 0.8 H Southwest Retaining Wall 14.1 10.0 0.7 H

7.4.8 MSE Wall Material and Compaction

The wall backfill material should conform to the OSSC Section 00596A.11(b) for MSE Granular Wall Backfill (ODOT, 2018c). We recommend that the OSSC criteria be amended to require that backfill material passing No. 200 sieve shall not exceed 10 percent by weight. This tighter restriction on the fines content will ensure that MSE wall backfill will not be at risk for internal settlement due to poor compaction of over optimum moisture backfill. Heavy compaction equipment should not be allowed closer than three feet to the retaining wall to prevent wall yielding and/or damage.

7.4.9 Retaining Wall Backfill Material and Drainage – MSE Walls

Suitable drainage for walls can be provided by granular backfill material and a wall base subdrain system consisting of a 6-inch-diameter perforated or slotted drain pipe wrapped in an envelope of filter material at least 12 inches thick, confined by a separation geotextile. The filter material is specified in Section 02610.10(a) of the OSSC. The subdrain should be above the typical groundwater level, convey any collected seepage to the end of the wall, and daylight at low spots below the wall elevation.

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7.5 Embankment Fills

We understand that there will be new fill placed for each new approach embankments. At the east embankment fill placed near the abutment will be 6 feet at the center of the embankment and up to 15 feet near the southeast retaining wall. At the west embankment, there will be approximately 5 feet of fill placed near the center of the embankment and as much as 11 to 12 feet of new fill at the locations of the northwest and southwest retaining walls. The new fill will be thickest at the location of the bridge abutments and will taper down away from the bridge.

The new fill will be retained by the two abutment retaining walls and the four MSE retaining walls at the proposed bridge. Where possible, the embankment will be sloped to match existing grade.

7.5.1 Embankment Material and Compaction

We assume that the embankment will be constructed using ODOT Borrow Material meeting OSSC Section 0330.12, consisting of non-plastic silty sand and sandy silt. Embankment construction should be in accordance with OSSC 00330.42 and 00330.43. If ODOT Borrow Material is used, it may be difficult to control the moisture content.

If embankment construction is carried out during wet weather, we recommend that ODOT Stone Embankment Material from OSSC 00330.16 be used.

7.5.2 Embankment Slope

In locations where the new fill is not retained behind retaining structures, new embankment fill will be stable at a slope of 2H:1V. If ODOT Stone Embankment Material is used for the embankment construction, the slopes can be 1.5H:1V.

7.5.3 Embankment Settlement

The clays of the Missoula Flood Deposit unit will settle upon placement of the new fill embankment. This settlement has been predicted assuming that the clay is sufficiently overconsolidated so that all new changes in stress occur within the recompression zone for the clay. The settlement of the new fill embankment is estimated to be between 5 to 10 inches. The majority of this settlement, 90 percent, will happen between one to three months.

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7.5.4 Embankment Construction Considerations

The settlement of the embankment will be a risk to this project due to the construction sequencing. For a normal new bridge project, the embankment can be placed and allowed to consolidate while other project components are installed. For this project, however, the new embankment fill will be placed at the very end of the construction sequence. This may lead to poor performance of the bridge as the drilled shaft supported bridge bents will remain mostly rigid comparatively.

In order to overcome this challenge, we recommend that the initial paving of the roadway is temporarily completed during the initial construction sequencing. The long-term settlement of the embankment must be carefully monitored with surface settlement markers over the course of a few months to understand when the long-term settlements are complete. A minimum of eight settlement markers are recommended. These will be placed in four rows of two settlement markers each. The two rows would be behind the east and the west embankments each at distances of two feet from the back edge of the reinforced concrete pile cap and abutment wing wall portion and 50 feet further away. Upon reaching an appropriate “completion” of settlement, the upgraded stretch of pavement, including the bridge and approach embankments, should receive finished paving.

These settlement markers can also be used to monitor the settlement of the MSE walls. Once the MSE walls have nearly reached complete settlement, the MSE wall rigid facing can be placed.

Roadway embankment construction considerations regarding site preparations and earthwork are presented below.

7.6 Pavement Design Recommendations

Pavement evaluation for the Little Pudding River Bridge project was performed in accordance with the recommended procedures and guidelines in the 2011 ODOT Pavement Design Guide (PDG) and the 1993 AASHTO Guide for Design of Pavement Structures. The results, conclusions, and recommendations in this report are based on our understanding and synthesis of design team requirements, field data, structural pavement analysis, and our engineering judgement.

We understand the new bridge approach pavement will be constructed with asphalt concrete pavement (ACP). The project does not include any pavement rehabilitation. Subgrade preparation, pavement, base course materials, and installation should be completed in accordance with the ODOT OSSC.

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7.6.1 Traffic Data

Marion County provided us with traffic counts and vehicle classifications recorded in July 2018. The average annual daily traffic (AADT) volume is 10,981 vehicles with a truck (FHWA Vehicle Classes 4 through 13) volume of 10.7 percent of AADT. An annual growth rate of 1 percent was provided by the County. Exhibit 7-10 summarizes the vehicle classification breakdown based on the provided traffic counts. Exhibit 7-10: Summary of Percentage of Vehicle Classes

Percentage of Vehicle Vehicle Type (FHWA Vehicle Class) AADT Motorcycles (1) 0.66 Passenger cars (2) 68.46 Single unit 2-axle 4-tire trucks (3) 20.21 Buses (4) 0.66 Single unit 2-axle 6-tire trucks (5) 8.00 Single unit 3-axle trucks (6) 0.37 Single unit 4 or more axle trucks (7) 0.05 Single trailer 3 or 4 axle trucks (8) 1.00 Single trailer 5-axle trucks (9) 0.28 Single trailer 6 or more axle trucks (10) 0.17 Multi-trailer 5 or less axle trucks (11) 0.02 Multi-trailer 6-axle trucks (12) 0.03 Multi-trailer 7 or more axle trucks (13) 0.08

ODOT two-way truck conversion factors for flexible pavement were used to determine design equivalent single axle (18-kip) loads (ESALs) for pavement design. The design ESAL after the construction year of 2019 is about 115,500. The 30-year design life ESALs are about 4.2 million.

7.6.2 Subgrade

The assumed subgrade soil for new bridge approach pavement will be medium stiff to stiff silt or compacted ODOT Borrow Material composed of any combination of non-plastic to low-plasticity silts, sand, and gravel. We recommend that the prepared subgrade be inspected to identify any soft or weak sports prior to the placement of pavement material. The subgrade inspection should, at a minimum, consist of proof-rolling the subgrade with a fully loaded dump truck. Soft or weak spots should be over-excavated and replaced with compacted aggregate base in accordance with OSSC, Section 00331. The subgrade should be compacted to a minimum density of 95 percent of the maximum dry density as determined

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by ASTM D 698 for the upper 12 inches of subgrade soil. Where the exposed subgrade consists of fine-grained soils, we recommend that a non-woven separation geotextile be used between soil subgrade and aggregate base to separate and reduce the potential for fines to migrate into the aggregate base. The non-woven separation geotextile should meet the requirements in OSSC, Section 02320.

7.6.3 ACP Design Recommendations

We understand that new ACP will be required for new bridge approach pavement sections. The 2011 ODOT PDG requires a minimum design life of 30 years for new ACP at bridge approaches. The design life periods used by ODOT are chosen so that the design period traffic will result in a pavement structure sufficient to survive through the analysis period. It should be recognized that intermittent treatments will be needed to preserve the surface quality and ensure the structure lasts through the analysis period.

7.6.3.1 ACP Design Parameters

The following additional assumptions should be reviewed by the design team and Agency to evaluate their suitability for this project. Changes in the assumptions will affect the corresponding pavement section recommendations.

. Subgrade Resilient Modulus (Mr) = 6,500 psi . 30-year design life for bridge approaches . Standard Deviation = 0.49 . Initial Serviceability = 4.2 . Terminal Serviceability = 2.5 . Reliability = 85 percent . Drainage Coefficient = 1.0 (good)

7.6.3.2 Recommended New ACP Section

We designed the new ACP section with a 30-year design life using the data, procedures, and assumptions discussed in the preceding sections. ACP design recommendations are presented in Exhibit 7-11.

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Exhibit 7-11: Recommended New ACP Section for Silverton Road

30-year Design Life Material Thickness (in) Material Requirements Level 3, ½-inch dense HMAC, ACP Wearing Course 2 PG 64-22 binder 6 Level 3, ½-inch dense HMAC, ACP Base Course (two equal lifts) PG 64-22 binder 1-inch or ¾-inch minus dense- Base Rock 12 graded aggregate base

The required AC mix design level, gradation, and binder grade is a Level 3, ½-inch dense HMAC with PG 64-22 binder. Base course materials should consist of 1-inch or ¾-inch minus aggregate materials. Aggregate base materials should meet OSSC, Section 02630. Asphalt grade is selected based on Table J-2 of the 2011 ODOT PDG for rural highway with design ESAL between 3 and 10 million. The new pavement section should be tied into the existing pavement section in accordance with Oregon Standard Drawing Asphalt Pavement Details RD610.

8 GENERAL CONSTRUCTION CONSIDERATIONS

8.1 Site Preparation

Site preparation will include the following: (1) clearing, grubbing, and roadside cleanup; (2) removal of existing structures and underground utilities; and (3) subgrade preparation and excavation. These construction activities should generally be accomplished in accordance with ODOT OSSC. If temporary shoring is needed, the design of such shoring is traditionally the responsibility of the contractor.

8.2 Temporary Cut and Fill Slopes

Temporary cut slopes are typically the responsibility of the contractor and should comply with applicable local, state, and federal safety regulations, including the current OSHA Excavation and Trench Safety Standards. For general guidance, we suggest that temporary construction slopes be made at 1.5H:1V or flatter.

8.3 Temporary Shoring

Temporary shoring may be necessary at each of the new bridge abutments in order to install the pile caps. Choice of temporary shoring is the responsibility of the contractor. Sheet

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piling would be feasible; however, it will not be able to be driven into the very dense Pleistocene Gravel unit. The contractor should keep this in mind when selecting a temporary shoring system.

8.4 Dewatering & Control of Surface Water

Dewatering may be required for installation of the bridge abutment pile caps and/or the MSE embankment retaining walls in locations where groundwater is near the surface. Surface water should be controlled so as not to allow it to flow into open excavations. Any water collected during dewatering as well as any excavated soil should be treated and disposed of in a manner meeting local, state, and federal environmental regulations and requirements.

9 LIMITATIONS

This report was prepared for the exclusive use of Marion County Public Works and their representatives for design of the bridge abutments and foundations, retaining walls, and the embankments for the new proposed Little Pudding River Bridge (No. 00962A) located on the Silverton Road. This report should not be used without our approval if any of the following occurs:

. Conditions change due to natural forces or human activity under, at, or adjacent to the site. . Assumptions stated in this report have changed. . Project details change or new information becomes available such that our analyses, conclusions, and recommendations may be affected. . More than 10 years have passed since the date of this report.

If any of these occur, we should be retained to review the applicability of our recommendations.

Our conclusions and recommendations are based on the following:

. The limitations of our approved scope, schedule, and budget described in our scope of services in the Contract with Marion County, dated November 7, 2016. . Our understanding of the project and information provided by Marion County between November 2016 and November 2018. . Subsurface conditions we observed in the borings as they existed during the time of drilling. . The results of testing performed on samples we collected from the explorations.

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. The requirements of the ODOT Geotechnical Design Manual (2018b) and AASHTO LRFD Bridge Design Specifications (2017).

We recommend retaining Shannon & Wilson to review the portions of the plans and specifications pertaining to geotechnical components presented in this report to check consistency with our recommendations.

We cannot assume responsibility or liability for the adequacy of our recommendations without our being retained to observe geotechnical construction activities. Our involvement will help with developing alternative recommendations if the conditions observed during construction are different from those assumed in this report. Our support services should include review of the contractor’s geotechnical submittals; observation of earthwork, foundation installation, and excavations; and as-needed support to clarify related issues.

The professional opinions, recommendations, and conclusions contained in this report are valid for a period not greater than 10 years from the date of this report. This time limitation is included in recognition that the site conditions can and do change with time.

We have prepared the document “Important Information About Your Geotechnical/Environmental Report” to assist you and others in understanding the use and limitations of this report. It is attached to this report. Please read this document to learn how you can lower your risks for this project.

10 REFERENCES

Allen, J.E., Burns, M., and Burns, S., 2009, Cataclysms on the Columbia: The Great Missoula Floods (2nd ed.): Portland, Oregon, Ooligan Press, 204 p.

American Association of State Highway and Transportation Officials (AASHTO), 2017, AASHTO LRFD Bridge Design Specifications: Customary U.S. Units (8th ed.): Washington, D. C.

Goldfinger, C., Nelson, C.H., Morey, A., Johnson, J.E., Gutierrez-Pastor, J., Eriksson, A.T., Karabanov, E., Patton, J., Gracia, E., Enkin, R., Dallimore, A., Dunhill, G., and Vallier, T., 2012, Turbidite Event History—Methods and Implications for Holocene Paleoseismicity of the Cascadia Subduction Zone: U.S. Geological Survey Professional Paper 1661–F, 332 p., 64 figures.

Oregon Department of Transportation (ODOT), 2018a, Bridge Design and Drafting Manual dated May 2018: Salem, Oregon. available: https://www.oregon.gov/ODOT/HWY/BRIDGE/Pages/standards_manuals.aspx#Br idge_Design_&_Drafting_Manual.

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Oregon Department of Transportation (ODOT), 2018b, Geotechnical Design Manual dated June 2018: Salem, Oregon. available: https://www.oregon.gov/ODOT/HWY/GEOENVIRONMENTAL/pages/geotechnic al_design_manual.aspx.

Oregon Department of Transportation, 2018c, Oregon Standard Specification for Construction, Salem, Oregon, available: https://www.oregon.gov/ODOT/Business/Documents/2018_STANDARD_SPECIFI CATIONS.pdf.

Oregon Department of Transportation, 2018d, ODOT Design Response Spectrum Program ODOT_ARS.v.2014.16.xlsx: ODOT website https://www.oregon.gov/ODOT/HWY/BRIDGE/Pages/seismic.aspx, accessed 10/14/2018 12:01 PM.

Oregon Department of Transportation, 1987, Soil and Rock Classification Manual, available: ftp://ftp.odot.state.or.us/techserv/Geo- Environmental/Geotech/Manuals/Soil_Rock_Classification_Manual.pdf

Personius, S.F., compiler, 2002, Fault number 719, Salem-Eola Hills homocline, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults, accessed 03/01/2017 04:15 PM.

Personius, S.F., compiler, 2002, Fault number 871, Mill Creek fault, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults, accessed 03/01/2017 04:19 PM.

Personius, S.F., compiler, 2002, Fault number 872, Waldo Hills fault, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults, accessed 03/01/2017 04:23 PM.

Personius, S.F., compiler, 2002, Fault number 870, Owl Creek fault, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults, accessed 03/01/2017 04:28 PM.

Personius, S.F., compiler, 2002, Fault number 873, Mount Angel fault, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults, accessed 03/01/2017 04:36 PM.

Personius, S.F., compiler, 2002, Fault number 717, Newberg fault, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults, accessed 03/01/2017 04:42 PM.

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Personius, S.F., compiler, 2002, Fault number 716, Canby-Molalla fault, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults, accessed 03/01/2017 04:48 PM.

Personius, S.F., compiler, 2002, Fault number 718, Gales Creek fault zone, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults, accessed 03/01/2017 04:55 PM.

Personius, S.F., and Nelson, A.R., compilers, 2006, Fault number 781, Cascadia subduction zone, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, http://earthquakes.usgs.gov/hazards/qfaults, accessed 03/01/2017 04:01 PM.

Tolan, T.L., Beeson, M.H., 1999, Geologic Map and Database of the Salem East and Turner 7.5-Minute Quadrangles, Marion County, Oregon: U.S. Geological Survey Open- File Report 00-351, scale 1:24,000.

24-1-04094 November 27, 2018 37 Washington

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LEGEND 0 0.25 0.5 1 Little Pudding River (Silverton Road NE) Alluvial deposits Bridge #00962A Missoula Flood deposits Scale in Miles Marion County, Oregon

GEOLOGIC MAP

NOTES November 2018 24-1-04094-001 1. Geologic mapping from Oregon Geologic Data Compilation, release 6 (OGDC-6), by DOGAMI. FIG. 3 Filename: T:\Projects\24-1\4094_Little T:\Projects\24-1\4094_Little PuddingFilename:River Bridge\Avmxd\GeologicMap.mxd Login: Date: clv 5/11/2017 File: I:\EF\24-1 PDX\04000s\04094 Little Pudding River Bridge\Graphics\CAD\Bridge962A_SilvertonRoad_working.dwg Date: 07-07-2017 Author: clv Subsurface Unit Designation

Approximate Elevation in Feet (NAVD 88) 100 110 120 130 140 150 160 170 180 190 200 60 70 80 90 (Proj. 24' SW) 11-23-16 0 B-1 LEGEND 50/1st 5" 16 /100 6 Existing Ground Surface Date of Completion Profile Line Designation and Projection of Boring to Bottom of Boring in Blows/Foot or Blows/Inches Driven (e.g., /100 = 100% Recovery) SPT Sample and Penetration Resistance Soil Type Symbol Shelby Tube Sample with Recovery FILL 100 (Proj. 18' SE) 11-23-16 B-1 43 51 50 50/5" 68 9 3 4 2 0 0 /100 0 3 3 (Proj. 17' SE) 11-22-16 B-2 50/2" 50/1st 2" 97/11" 50/1st 3" 50/1st 3" 70/10" 62 50/1st 5" 50/6" 50/1st 5" 50/1st 6" 38 10 7 1 7 0 /100 0 3 5 7 / 28 Little Pudding River 200 0 0 Vertical Exaggeration = 2x Horizontal Scale in Feet Vertical Scale in Feet PLEISTOCENE SAND Approximate Distance in Feet AND GRAVEL 40 20 Proposed Bridge 80 40 (Proj. 18' SE) 11-29-16 B-3 300 50/1st 4" 50/1st 3" 50/1st 4" 50/1st 3" 50/1st 4" / 50/4" 65 50/1st 5" 50/1st 4" 50/1st 5" 50/1st 5" 46 27 33 11 7 /100 4 10 0 4 4 8 .Ground surface generated from contours in drawing 1. .Proposed features from Bridge962ASilvertonRd.dwg, 5. See Figure 2 for profile location. 3. .Profile generalized from materials observed in borings. 2. .Boring locations and elevations are approximate. 4. DEPOSITS - FINE GRAINED provided by Marion County on March 22, 2017. Bridge962ASilvertonRd.dwg, provided by Marion County conditions. See Appendix A for complete boring logs and explanations of symbols. on March 22, 2017. Variations may exist between profile and actual MISSOULA FLOOD NOTES (Proj. 17' SE) 11-29-16 B-4 50/1st 3" 50/3" 61 41 19 19 9 14 10 14 7 7 5 10 400 FILL Proposed Ground Surface S November 2018 HANNON & Little Pudding River (Silverton Road NE) INTERPRETIVE SUBSURFACE Marion County, Oregon Bridge No. 00962A PROFILE A-A' W ILSON, 500 120 130 140 150 160 170 180 190 200 100 110

60 70 80 90

I NC. 24-1-04094-001 88) (NAVD Feet in Elevation Approximate FIG. 4 ASSUMED SUBSURFACE SERVICE LIMIT STRENGTH LIMIT EXTREME EVENT LIMIT PROFILE NOMINAL RESISTANCE (kips) NOMINAL RESISTANCE (kips) NOMINAL RESISTANCE (kips) Based on Nearby Explorations: B-3 0 200 400 600 800 1000 1200 1400 0 200 400 600 800 1000 1200 1400 0 200 400 600 800 1000 1200 1400 0 0 0 0' Nominal Side: 0.5-inch Settlement Nominal Side New Fill Nominal Side Nominal Base: 0.5-inch Settlement Nominal Base Nominal Base 6' Existing Fill Factored Total: 0.5- inch Settlement Factored Compression Total Factored Compression Total 10 10 10 10.5' Nominal Side: 1-inch Settlement

Nominal Base: 1-inch Settlement

Factored Total: 1-inch Settlement

20 20 20

Missoula Flood Deposits ‐ Fine 30 30 30

40 40 40 DRILLED SHAFT DRILLED SHAFT BASE DEPTH (feet) DRILLED SHAFT DRILLED SHAFT BASE DEPTH (feet) DRILLED SHAFT DRILLED SHAFT BASE DEPTH (feet) 48.5' 50 50 50

Pleistocene Sand & Gravel 60 60 60

70 70 70 SERVICE LIMIT NOTES: STRENGTH LIMIT NOTES: EXTREME EVENT LIMIT NOTES: 1. Recommended resistance factors per ODOT GDM are 1.0 for both side and 1. Recommended compression resistance factors per ODOT GDM are 0.55 1. Recommended resistance factors per ODOT GDM for both side and base base resistance. and 0.5 for side and base resistance, respectively. resistance are 1.0 for compression and 0.8 for uplift.

2. Settlement is based on a single shaft. No group action is considered. 2. Shaft uplift resistance estimated by using the nominal side resistance 3. Downdrag load of 90 kips must be subtracted from the Factored Total. shown above and a recommended resistance factor of 0.45 for Strength Limit and 0.8 for Extreme Event Limit. (AASHTO, 2017)

GENERAL NOTES Little Pudding River (Silverton Road NE) 1. The analyses were performed based on guidelines included in the ODOT Geotechnical Design Manual (GDM) and local experience. The analyses are based on a Bridge #00962A single shaft and do not consider group action of closely spaced shafts (closer than 4 diameters, center to center). Marion County, Oregon 2. Factored total shaft resistance shown on plots is determined by adding its nominal side and base resistances multiplied by the appropriate resistance factors as noted above. ESTIMATED AXIAL SHAFT RESISTANCE

3. Estimated shaft resistance assumes that if casing is used, it will be removed after the shaft installation. If, however, the casing is left in place, grouting should be 4-FOOT DIAMETER DRILLED SHAFT used to fill all potential voids around the casing and the estimated resistance given above should be re-evaluated. EAST ABUTMENT

4. Settlement in the Missoula Flood Deposits caused by the approach embankments will create static downdrag on the drilled shafts. An unfactored downdrag of 90 November 2018 24-1-04094-001 kips is recommended. A load factor of 1.25 is recommended to determine factored static downdrag load. SHANNON & WILSON, INC. FIG. 5 Geotechnical and Environmental Consultants ASSUMED SUBSURFACE SERVICE LIMIT STRENGTH LIMIT EXTREME EVENT LIMIT PROFILE NOMINAL RESISTANCE (kips) NOMINAL RESISTANCE (kips) NOMINAL RESISTANCE (kips) Based on Nearby Explorations: B-2 0 200 400 600 800 1000 1200 1400 0 200 400 600 800 1000 1200 1400 0 200 400 600 800 1000 1200 1400 0 0 0 0' New Fill Nominal Side: 0.5-inch Settlement Nominal Side Nominal Side

5' Nominal Base: 0.5-inch Settlement Nominal Base Nominal Base

Existing Fill Factored Total: 0.5- inch Settlement Factored Compression Total Factored Compression Total 10 10 10 Nominal Side: 1-inch Settlement 12' Nominal Base: 1-inch Settlement

Factored Total: 1-inch Settlement

20 20 20

Missoula Flood Deposits ‐ Fine 30 30 30

40 40 40 DRILLED SHAFT DRILLED SHAFT BASE DEPTH (feet) DRILLED SHAFT DRILLED SHAFT BASE DEPTH (feet) 46.5' DRILLED SHAFT BASE DEPTH (feet)

50 50 50

Pleistocene Sand & Gravel 60 60 60

70 70 70 SERVICE LIMIT NOTES: STRENGTH LIMIT NOTES: EXTREME EVENT LIMIT NOTES: 1. Recommended resistance factors per ODOT GDM are 1.0 for both side and 1. Recommended compression resistance factors per ODOT GDM are 0.55 1. Recommended resistance factors per ODOT GDM for both side and base base resistance. and 0.5 for side and base resistance, respectively. resistance are 1.0 for compression and 0.8 for uplift.

2. Settlement is based on a single shaft. No group action is considered. 2. Shaft uplift resistance estimated by using the nominal side resistance 3. Downdrag load of 90 kips must be subtracted from the Factored Total. shown above and a recommended resistance factor of 0.45 for Strength Limit and 0.8 for Extreme Event Limit. (AASHTO, 2017)

GENERAL NOTES Little Pudding River (Silverton Road NE) 1. The analyses were performed based on guidelines included in the ODOT Geotechnical Design Manual (GDM) and local experience. The analyses are based on a Bridge #00962A single shaft and do not consider group action of closely spaced shafts (closer than 4 diameters, center to center). Marion County, Oregon 2. Factored total shaft resistance shown on plots is determined by adding its nominal side and base resistances multiplied by the appropriate resistance factors as noted above. ESTIMATED AXIAL SHAFT RESISTANCE

3. Estimated shaft resistance assumes that if casing is used, it will be removed after the shaft installation. If, however, the casing is left in place, grouting should be 4-FOOT DIAMETER DRILLED SHAFT used to fill all potential voids around the casing and the estimated resistance given above should be re-evaluated. WEST ABUTMENT

4. Settlement in the Missoula Flood Deposits caused by the approach embankments will create static downdrag on the drilled shafts. An unfactored downdrag of 90 November 2018 24-1-04094-001 kips is recommended. A load factor of 1.25 is recommended to determine factored static downdrag load. SHANNON & WILSON, INC. FIG. 6 Geotechnical and Environmental Consultants Elevation Varies

New and Existing Fill 15.75 ft Abutment Wall/Pile Cap

Non-liquefiable Fine-Grained Missoula Flood Deposits H Liquefied Fine-Grained Little Pudding River Missoula Flood Deposits Elevation Varies Drilled Shaft Non-liquefied Fine-Grained Misoula Flood Deposits and Pleistocene Sand and Gravel ath SOIL PRESSURE NOTES

Login: 46 kips/ft 1. Pressure value is in kips per square foot (ksf).

2. Resolve lateral earth pressure force acting on

11-14-2018 the shaft by multiplying the earth pressure force by three times the pile diameter.

Date: 3. Apply a 46 kip per lineal foot force at the top H of the shaft, in the opposite direction of the lateral spread loading, to account for the resistance provided by the opposite integral abutment. Multiply the resisting force by the shaft center-to-center spacing to determine the resultant force acting on the shaft.

4. Pressure diagram only applies to lateral 0.8 ksf spread loading in the longitudinal direction (toward Little Pudding River).

NOT TO SCALE

Little Pudding River (Silverton Road NE) LEGEND Bridge #00962A East Abutment H = 23.25 feet Marion County, Oregon

West Abutment H = 30.75 feet LATERAL SPREADING INDUCED EARTH PRESSURES ON DRILLED SHAFT FOUNDATIONS

I:\EF\24-1 PDX\04000s\04094 Little Pudding River Bridge\Graphics\CAD\Lateral Spread Pressures.dwg November 2018 24-1-04094-001 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants FIG. 7 Filename: SURCHARGE, q TOTAL LATERAL EQUIVALENT FLUID PRESSURES

Drained granular backfill material H + +

SOIL BACKFILL SURCHARGE SEISMIC BACKFILL COMPONENT COMPONENT COMPONENT

YIELDING WALL SOIL COMPONENT NON-YIELDING WALL SOIL COMPONENT

H H P = (34H x ) lbs/ft wall length P = (57H x ) lbs/ft wall length R 2 R 2

RESULTANT FORCE (PR ) RESULTANT FORCE (PR ) 1 1 3 H 3 H

34H1 57H1 YIELDING WALL SURCHARGE COMPONENT NON-YIELDING WALL SURCHARGE COMPONENT

PR = 0.22qH lbs/ft wall length PR = 0.44qH lbs/ft wall length

RESULTANT FORCE (PR ) RESULTANT FORCE (PR )

1 1 2 H 2 H

0.22q1 0.44q1

YIELDING WALL SEISMIC BACKFILL COMPONENT NON-YIELDING WALL SEISMIC BACKFILL COMPONENT

24H1 H 60H1 H PR = (24H x ) lbs/ft wall length P = (60H x ) lbs/ft wall length 2 R 2

RESULTANT FORCE (PR ) RESULTANT FORCE (PR )

2 2 3 H 3 H

NOTES Little Pudding River (Silverton Road NE) 1. Units are pounds per square Bridge No. 00962A foot (psf). Marion County, Oregon 2. Backfill unit weight of 130 pcf. 3. Backfill friction angle is 34 deg. LATERAL EARTH PRESSURE 4. Wall backfill is assumed to be drained DISTRIBUTION ON NEW granular backfill material. MSE RETAINING WALLS 5. Seismic pressures provided for peak ground acceleration associated with the "Life Safety" November 2018 24-1-04094-001 criteria. SHANNON & WILSON, INC. Geotechnical and Environmental Consultants FIG. 7 File: I:\EF\24-1 PDX\04000s\04094 Little Pudding River Bridge\Graphics\CAD\Lateral Earth Pressures.dwg Date: 11-06-2018 Author: ath FS = 1.1 FS = 1.1 185 Traffic Surcharge = 125 psf EAST Traffic Surcharge = 125 psf WEST ABUTMENT 180 ABUTMENT PILE CAP PILE CAP 175 NEW FILL Magnitude: 46 kips/ft NEW FILL Magnitude: 24 kips/ft 170 EXISTING FILL

165 EXISTING FILL

160 FINE-GRAINED MISSOULA FLOOD DEPOSITS

155 Groundwater Elevation Groundwater Elevation RIP RAP 150 RIP RAP FINE-GRAINED MISSOULA FLOOD DEPOSITS 145

140 Elevation (ft) Elevation

135 Failure Surface LIQUEFIED MISSOULA FLOOD DEPOSITS

Elevation NAVD88 (ft) Elevation NAVD88 FINE-GRAINED MISSOULA FLOOD DEPOSITS 130

125 Failure Surface

120 PLEISTOCENE SAND AND GRAVEL 115

110

105

100 0 100 200 300 Distance (ft)

Name Unit Weight (pcf) Cohesion' (psf) Phi' (°)

New Fill 130 15 34 0 20 40

32 Existing Fill 115 25 Scale in Feet

Fine-Grained 105 100 32 Missoula Flood Deposits Fine-Grained 105 0 12 NOTES Little Pudding River (Silverton Road NE) Missoula Flood Deposits (Liquefied) 1. Ground surface generated from contours in drawing Bridge #00962A Bridge962ASilvertonRd_EG and FG Surfaces.dwg, 130 38 Marion County, Oregon Pleistocene Sand and Gravel 15 provided by Marion County on July 11, 2018. 2. See Figure 2 for anlysis locations. GLOBAL STABILITY RESULTS 3. Crtitical failture surface estimated using the entry and exit PROFILE A-A' - search criteria and the Spencer (1967) Method 4. Groundwater elevations estimated from levels observed POST-SEISMIC CASE during drilling. November 2018 24-1-04094-001 5. See report text for additional information about analyses SHANNON & WILSON, INC. and assumptions. Geotechnical and Environmental Consultants FIG. 8 File: I:\EF\24-1 PDX\04000s\04094 Little Pudding River Bridge\Graphics\CAD\XRef\Slope_Stability_A-A'.dwg Date: 11-13-2018 Author: ath 11-13-2018 Date: Bridge\Graphics\CAD\XRef\Slope_Stability_A-A'.dwg River Little Pudding PDX\04000s\04094 File: I:\EF\24-1 FIG. 10 24-1-04094-001 MSE WALL Bridge #00962A Marion County, Oregon VERSUS FOOTING WIDTH FOR Little Pudding River (Silverton Road NE) Service Limit State for 1-inch settlement Service Limit State for 2-inch settlement Strength limit state State Limit Event Extreme FACTORED BEARING RESISTANCE BEARING FACTORED November 2018 SHANNON SHANNON & WILSON, INC. Geotechnical and Environmental Consultants and Environmental Geotechnical f, a total unit weight of of weight unit total f, a Width of MSE Wall, B (feet) MSE Wall, Width of 1 1.0 0.65 f. We assumed that the bottom of the footing was 2 feet feet 2 was footing the of bottom the that f. We assumed ksf - kips per square foot (1 kip = 1000 pounds) 1.0 1.0 N/A Sliding Shear Bearing Capacity - pounds per cubic foot; pcf Service Strength Limit State Extreme Event f, a Poisson's ratio of 0.25, and a soil 0.25, of elastic ratio Poisson's modulusf, a of 100 ks - pounds per square foot; NOTES We recommend using the following resistance factors for footing LRFD design; the plotted bearing capacities use the bearing capacity resistance factors. The factored bearing capacities are based on a soil friction angle of 32 degrees, a soil cohesion of 50 ps 105 pc below thebelow ground surface. psf 8 10121416182022242628 1. 2. 3. 0 60 50 40 30 20 10

Factored Bearing Resistance (ksf) Resistance Bearing Factored FIG. 10 2.3 1.7 SOUTH Traffic Surcharge: 250 pcf NORTH EAST EAST 180 RETAINING WALL RETAINING WALL

NEW FILL 170 EXISTING FILL

160 Failure Surface

Groundwater Elevation

150 FINE-GRAINED MISSOULA FLOOD DEPOSITS

140

Failure Surface 130

Elevation NAVD88 (ft) 120 PLEISTOCENE SAND AND GRAVEL

110

100

90

80 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 187 Distance (ft)

0 20 40

Name Unit Weight (pcf) Cohesion' (psf) Phi' (°) Scale in Feet

New Fill 130 15 34

Existing Fill 115 25 32 NOTES Little Pudding River (Silverton Road NE) 1. Ground surface generated from contours in drawing Bridge #00962A Fine-Grained 105 100 32 Bridge962ASilvertonRd_EG and FG Surfaces.dwg, Marion County, Oregon Missoula Flood Deposits provided by Marion County on July 11, 2018. 2. See Figure 2 for anlysis locations. GLOBAL STABILITY RESULTS 130 15 38 Pleistocene Sand and Gravel 3. Crtitical failture surface estimated using the entry and exit PROFILE B-B' - search criteria and the Spencer (1967) Method 4. Groundwater elevations estimated from levels observed STATIC CASE during drilling. November 2018 24-1-04094-001 5. See report text for additional information about analyses SHANNON & WILSON, INC. and assumptions. Geotechnical and Environmental Consultants FIG. 11 File: I:\EF\24-1 PDX\04000s\04094 Little Pudding River Bridge\Graphics\CAD\XRef\Slope_Stability_B-B'.dwg Date: 11-16-2018 Author: ath 11-16-2018 Date: Bridge\Graphics\CAD\XRef\Slope_Stability_B-B'.dwg River Little Pudding PDX\04000s\04094 File: I:\EF\24-1 1.6 1.1 SOUTH Traffic Surcharge: 125 pcf NORTH EAST EAST 180 RETAINING WALL RETAINING WALL

NEW FILLNEW FILL 170 EXISTINGEXISTING FILL FILL

160 Failure Surface

Groundwater Elevation

150 FINE-GRAINED MISSOULA FLOOD DEPOSITS

140

130 Failure Surface

Elevation NAVD88 (ft) 120

110 PLEISTOCENE SAND AND GRAVEL

100

90

80 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 187 Distance (ft)

0 20 40

Name Unit Weight (pcf) Cohesion' (psf) Phi' (°) Scale in Feet

New Fill 130 15 34 NOTES 1. Ground surface generated from contours in drawing Existing Fill 115 25 32 Bridge962ASilvertonRd_EG and FG Surfaces.dwg, Little Pudding River (Silverton Road NE) provided by Marion County on July 11, 2018. Bridge #00962A Fine-Grained 105 100 32 2. See Figure 2 for anlysis locations. Marion County, Oregon Missoula Flood Deposits 3. Crtitical failture surface estimated using the entry and exit search criteria and the Spencer (1967) Method GLOBAL STABILITY RESULTS 130 15 38 Pleistocene Sand and Gravel 4. Groundwater elevations estimated from levels observed PROFILE B-B' - during drilling. 5. Horizontal seismic load coefficient, kh = 0.22g is applied in SEISMIC CASE this analysis for Site Class C Life Safety. November 2018 24-1-04094-001 6. See report text for additional information about analyses SHANNON & WILSON, INC. and assumptions. Geotechnical and Environmental Consultants FIG. 12 File: I:\EF\24-1 PDX\04000s\04094 Little Pudding River Bridge\Graphics\CAD\XRef\Slope_Stability_B-B'_Seismic.dwg Date: 11-16-2018 Author: ath Date: 11-16-2018 Bridge\Graphics\CAD\XRef\Slope_Stability_B-B'_Seismic.dwg River Little Pudding PDX\04000s\04094 File: I:\EF\24-1 Traffic Surcharge: 250 pcf 1.5 NORTH SOUTH 1.6 180 WEST WEST RETAINING WALL RETAINING WALL

NEW FILL 170

EXISTING FILL

160

Groundwater Elevation 150 FINE-GRAINED MISSOULA FLOOD DEPOSITS

Failure Surface 140 Failure Surface Elevation NAVD88 (ft) 130

120 PLEISTOCENE SAND AND GRAVEL

110

100 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 Distance (ft)

0 20 40

Scale in Feet Name Unit Weight (pcf) Cohesion' (psf) Phi' (°)

New Fill 130 15 34 NOTES Little Pudding River (Silverton Road NE) Existing Fill 115 25 32 1. Ground surface generated from contours in drawing Bridge #00962A Bridge962ASilvertonRd_EG and FG Surfaces.dwg, Marion County, Oregon Fine-Grained 105 100 32 provided by Marion County on July 11, 2018. Missoula Flood Deposits 2. See Figure 2 for anlysis locations. GLOBAL STABILITY RESULTS 3. Crtitical failture surface estimated using the entry and exit Pleistocene Sand and Gravel 15 38 PROFILE C-C' - 130 search criteria and the Spencer (1967) Method 4. Groundwater elevations estimated from levels observed STATIC CASE during drilling. November 2018 24-1-04094-001 5. See report text for additional information about analyses SHANNON & WILSON, INC. and assumptions. Geotechnical and Environmental Consultants FIG. 13 File: I:\EF\24-1 PDX\04000s\04094 Little Pudding River Bridge\Graphics\CAD\XRef\Slope_Stability_C-C'.dwg Date: 11-16-2018 Author: ath 11-16-2018 Date: Bridge\Graphics\CAD\XRef\Slope_Stability_C-C'.dwg River Little Pudding PDX\04000s\04094 File: I:\EF\24-1 Traffic Surcharge: 125 pcf 1.1 NORTH SOUTH 1.2 180 WEST WEST RETAINING WALL RETAINING WALL

NEW FILL 170

EXISTING FILL

160

Groundwater Elevation 150 FINE-GRAINED MISSOULA FLOOD DEPOSITS Failure Surface

Failure Surface 140 Elevation NAVD88 (ft) 130

120 PLEISTOCENE SAND AND GRAVEL

110

100 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 Distance (ft)

0 20 40

Scale in Feet Name Unit Weight (pcf) Cohesion' (psf) Phi' (°) NOTES 130 New Fill 15 34 1. Ground surface generated from contours in drawing Bridge962ASilvertonRd_EG and FG Surfaces.dwg, Little Pudding River (Silverton Road NE) Existing Fill 115 25 32 provided by Marion County on July 11, 2018. Bridge #00962A 2. See Figure 2 for anlysis locations. Marion County, Oregon Fine-Grained 105 100 32 3. Crtitical failture surface estimated using the entry and exit Missoula Flood Deposits search criteria and the Spencer (1967) Method GLOBAL STABILITY RESULTS 4. Groundwater elevations estimated from levels observed Pleistocene Sand and Gravel 15 38 PROFILE C-C' - 130 during drilling. 5. Horizontal seismic load coefficient, kh = 0.22g is applied in SEISMIC CASE this analysis for Site Class C Life Safety. November 2018 24-1-04094-001 6. See report text for additional information about analyses SHANNON & WILSON, INC. and assumptions. Geotechnical and Environmental Consultants FIG. 14 File: I:\EF\24-1 PDX\04000s\04094 Little Pudding River Bridge\Graphics\CAD\XRef\Slope_Stability_C-C'_Seismic.dwg Date: 11-16-2018 Author: ath Date: 11-16-2018 Bridge\Graphics\CAD\XRef\Slope_Stability_C-C'_Seismic.dwg River Little Pudding PDX\04000s\04094 File: I:\EF\24-1 Silverton Road: Little Pudding River Bridge Replacement Geotechnical Engineering Report

Appendix A: Field Explorations Appendix A Field Explorations

CONTENTS . Drilling Logs, B-1 through B-4 . DCP Test Data, Borings B-1 through B-4

PLORATIONS APPENDIX A:APPENDIX FIELD EX

24-1-04094 November 27, 2018 A-i Silverton Road: Little Pudding River Bridge Replacement Geotechnical Engineering Report

APPENDIX A

A.1 GENERAL

Shannon &Wilson, Inc., explored subsurface conditions at the project site with four geotechnical borings, designated B-1 through B-4, which included Dynamic Cone Penetrometer (DCP) tests for each boring. All boring locations and elevations were surveyed by Marion County. Surveyed coordinates are provided on the Drill Logs in this appendix, and locations are shown on the Site and Exploration Plan, Figure 2. This appendix describes the techniques used to advance and sample the borings and presents logs of the materials encountered during drilling. DCP test procedures and data are also presented.

A.2 DRILLING

The borings were drilled on November 23, 2016, through November 29, 2016, using a truck- mounted CME-75 drill rig provided and operated by Western States Soil Conservation, Inc. (Western States) of Hubbard, Oregon. The borings were drilled to total depths ranging from 60.25 to 100.6 feet using mud rotary drilling techniques. Shannon & Wilson geology staff PLORATIONS were on site during drilling to locate the borings, observe drilling, collect samples, and maintain logs of the materials encountered.

A.2.1 DISTURBED SAMPLING

Disturbed samples were collected in the borings, typically at 2.5- to 5-foot depth intervals, using a standard 2-inch outside diameter (O.D.) split spoon sampler in conjunction with Standard Penetration Testing. In a Standard Penetration Test (SPT), ASTM D1586, the sampler is driven 18 inches into the soil using a 140-pound hammer dropped 30 inches. The number of blows required to drive the sampler the last 12 inches is defined as the standard

APPENDIX A:APPENDIX FIELD EX penetration resistance, or N-value. The SPT N-value provides a measure of in situ relative density of cohesionless soils (silt, sand, and gravel), and the consistency of cohesive soils (silt and clay). All disturbed samples were visually identified and described in the field, sealed to retain moisture, and returned to our laboratory for additional examination and testing.

SPT N-values can be significantly affected by several factors, including the efficiency of the hammer used. Automatic hammers generally have higher energy transfer efficiencies than cathead driven hammers. Based on information we received from Western States, the energy transfer efficiency of the hammer used on site averaged 94.2 percent when measured in May of 2015. All N-values presented in this report are in blows per foot, as counted in the field. No corrections of any kind have been applied.

24-1-04094 November 27, 2018 A-1 Silverton Road: Little Pudding River Bridge Replacement Geotechnical Engineering Report

An SPT was considered to have met refusal where more than 50 blows were required to drive the sampler 6 inches. If refusal was encountered in the first 6-inch interval (for example, 50 for 1.5”), the count is reported as 50/1st 1.5”. If refusal was encountered in the second 6-inch interval (for example, 48, 50 for 1.5”), the count is reported as 50/1.5”. If refusal was encountered in the last 6-inch interval (for example, 39, 48, 50 for 1.5”), the count is reported as 98/7.5”.

A.3 BOREHOLE ABANDONMENT

All borings were backfilled with bentonite grout or bentonite chips in accordance with Oregon Water Resource Department regulations. No wells or other instruments were installed in the boreholes. Borings that penetrated pavement were finished at the surface with matching sections of ODOT-approved asphalt cold patch and nominally compacted

gravel extending to a depth of at least 2 feet below the ground surface.

A.4 MATERIAL DESCRIPTIONS

In the field, soil samples were described and identified visually in accordance with the ODOT Soil and Rock Classification Manual (1987). The ASTM International (ASTM) D2488 PLORATIONS Visual-Manual method was also used as a guide in determining the key diagnostic properties of soils. Consistency, color, relative moisture, degree of plasticity, peculiar odors, and other distinguishing characteristics of the samples were noted. Once returned to our laboratory, the samples were re-examined, various standard laboratory tests were conducted, and the field descriptions and identifications were modified where necessary. Please refer to the ODOT Soil and Rock Classification Manual (1987) for definitions of descriptive terminology used in the Drill Logs.

A.5 DRILL LOGS

Summary logs of the borings are presented in the Drill Logs, Figures A1 through A4. Soil APPENDIX A:APPENDIX FIELD EX descriptions and interfaces on the logs are interpretive, and actual changes may be gradual. The left-hand portion of the drill logs gives individual sample intervals, percent recovery, Standard Penetration Test data, and natural moisture content measurements. Material descriptions and geotechnical unit designations are shown in the center of the drill log, and the right-hand portion provides a graphic log, miscellaneous comments, and a graphic depicting hole backfill details.

A.6 DYNAMIC CONE PENETROMETER TESTING

Pavement subgrade testing was conducted in all borings using a Dynamic Cone Penetrometer (DCP). The tests were conducted prior to drilling through the test interval.

24-1-04094 November 27, 2018 A-2 Silverton Road: Little Pudding River Bridge Replacement Geotechnical Engineering Report

The DCP is a device widely used to determine in-situ strength properties of base materials and subgrade soils. The four main components of the DCP include the cone, rod, anvil, and hammer. The cone is attached to one end of the DCP rod while the anvil and hammer are attached to the other end. Energy is applied to the cone tip through the rod by dropping the 17.64-pound hammer a distance of 22.6 inches against the anvil. The diameter of the cone is 0.16 inches larger than the rod to ensure that only tip resistance is measured. The number of blows required to advance the cone into the subsurface materials is recorded. The DCP index is the ratio of the depth of penetration to the number of blows of the hammer. This can be correlated to a variety of material properties, including CBR and Resilient Modulus. DCP testing was performed and documented by Shannon & Wilson field personnel. This appendix presents DCP Test Data in Figures A5 through A8.

PLORATIONS APPENDIX A:APPENDIX FIELD EX

24-1-04094 November 27, 2018 A-3 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants DRILL LOG Figure A1 OREGON DEPARTMENT OF TRANSPORTATION Page1 of 3 Hole No. B-1 Project Silverton Road: Little Pudding River Bridge Purpose Subsurface Exploration E.A. No. N/A Highway State Highway 213 County Marion Key No. N/A Hole Location Northing: ~ 237,527 Easting: ~ 203,140 Start Card No. N/A Equipment CME-75 Truck Rig Driller Western States Bridge No. 00962A Project Geologist Cody K. Sorensen, CEG Recorder Seth Sonnier Ground Elev. ~ 169 ft. Start DateNovember 23, 2016 End Date November 23, 2016 Total Depth 61.50 ft Tube Height N/A Test Type Rock Abbreviations Typical Drilling Abbreviations "A" - Auger Core "GP" - GeoProbe® Discontinuity Shape Surface Roughness Drilling Methods Drilling Remarks WL - Wire Line LW - Lost Water "X" - Auger J - Joint Pl - Planar P - Polished HS - Hollow Stem Auger WR - Water Return "C" - Core, Barrel Type F - Fault C - Curved Sl - Slickensided DF - Drill Fluid WC - Water Color "N" - Standard Penetration B - Bedding U - Undulating Sm - Smooth SA - Solid Auger DP - Down Pressure "U" - Undisturbed Sample Fo - Foliation St - Stepped R - Rough CA - Casing Advancer DR - Drill Rate "T" - Test Pit S - Shear Ir - Irregular VR - Very Rough HA - Hand Auger DA - Drill Action

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 0 0.00 - 1.50 Mud rotary drilling Asphalt Concrete; technique (5-inch hole) (Fill)

1.50 - 2.10 Dynamic Cone Base Aggregate; (Fill) Penetrometer Test N1 67 6-5-5 22 N- 1 (2.50-4.00) SILT; ML; Brown; Low plasticity; Moist; 2.10 - 11.00 performed at 1.7 ft Stiff; Trace organics; Micaceous; (Fill) SILT; ML; Light brown; Low plasticity; Moist; Very Soft to Stiff; Micaceous; (Fill) 5 N2 67 1-2-1 N- 2 (5.00-6.50) SILT; ML; Brown; Low plasticity; Moist; Soft; Trace organics; Micaceous; (Fill)

N3 100 0-0-0 37 N- 3 (7.50-9.00) SILT; ML; Brown; Low plasticity; Moist; Very Soft; Micaceous; (Fill)

10 U1 100 U- 1 (10.00-12.00) SILT; ML; Brown; Low plasticity; Moist; Very Soft; Micaceous; (Fill)

11.00 - 23.00 SILT with trace gravel N4 100 0-0-0 N- 4 (12.00-13.50) SILT with trace gravel and sand; ML; and trace sand to Blue-gray; Low plasticity; Moist to wet; Very Soft; Fine SILT; ML; Blue-gray; subrounded gravel; Fine to medium sand; Trace organics; Low plasticity; Moist (Missoula Flood Deposits - Fine) to wet; Very Soft; Fine subrounded to rounded gravel; Fine to medium sand; Trace organics; 15 N5 100 0-0-0 39 N- 5 (15.00-16.50) SILT; ML; Blue-gray; Low plasticity; Micaceous; (Missoula N5: LL=37, PL=25, Moist to wet; Very Soft; Trace organics; (Missoula Flood Flood Deposits - Fine) PI=12 Deposits - Fine)

20 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 Figure A1 Project Name Silverton Road: Little Pudding River Bridge Hole No. B-1 Page2 of 3

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 20 N6 100 0-0-2 N- 6 (20.00-21.50) SILT with trace gravel and sand; ML; Blue-gray; Low plasticity; Wet; Very Soft to Soft; Fine rounded gravel; Fine to medium sand; Trace organics; Micaceous; (Missoula Flood Deposits - Fine)

23.00 - 28.00 Silty CLAY; CL; Blue-gray; Medium plasticity; Moist; Soft; Trace organics and 25 N7 100 0-0-4 N- 7 (25.00-26.50) Silty CLAY; CL; Blue-gray; Medium wood fragments; plasticity; Moist; Soft; Trace organics and wood (Missoula Flood fragments; (Missoula Flood Deposits - Fine) Deposits - Fine)

11/23/16

Observed during drilling. 28.00 - 39.00 SILT with trace sand; ML; Blue-gray; Nonplastic; Moist; Very Loose to Loose; 30 N8 100 0-1-2 42 N- 8 (30.00-31.50) SILT with trace sand; ML; Blue-gray; Fine sand; Nonplastic; Wet; Very Loose; Fine sand; (Missoula Flood Micaceous; (Missoula Deposits - Fine) Flood Deposits - Fine)

35 N9 100 4-4-5 N- 9 (35.00-36.50) SILT with trace sand; ML; Blue-gray; Nonplastic; Wet; Loose; Fine sand; Micaceous; (Missoula Flood Deposits - Fine)

39.00 - 61.50 Sandy GRAVEL with 40 N10 87 28-33-35 N- 10 (40.00-41.50) Sandy GRAVEL with some silt; some silt; GW-GM; GW-GM; Blue-gray; Nonplastic; Moist; Very Dense; Fine Blue-gray to Brown; to coarse, subangular to rounded gravel; Fine to coarse Nonplastic fines; sand; (Pleistocene Sand and Gravel) Moist; Very Dense to Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

45 N11 100 40-50/5" N- 11 (45.00-45.90) Sandy GRAVEL with some silt; N11: 8.1% fines GW-GM; Blue-gray; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

50 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 Figure A1 Project Name Silverton Road: Little Pudding River Bridge Hole No. B-1 Page3 of 3

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 50 N12 80 17-19-31 N- 12 (50.00-51.50) Sandy GRAVEL with some silt; GW-GM; Blue-gray; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

55 N13 93 16-23-28 N- 13 (55.00-56.50) Sandy GRAVEL with some silt; GW-GM; Blue-gray; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

60 N14 67 20-20-23 N- 14 (60.00-61.50) Sandy GRAVEL with some silt; GW-GM; Blue-gray; Nonplastic fines; Moist; Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel) 61.50 End of hole

65

70

75

80 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants DRILL LOG Figure A2 OREGON DEPARTMENT OF TRANSPORTATION Page1 of 4 Hole No. B-2 Project Silverton Road: Little Pudding River Bridge Purpose Subsurface Exploration E.A. No. N/A Highway State Highway 213 County Marion Key No. N/A Hole Location Northing: ~ 237,557 Easting: ~ 203,191 Start Card No. N/A Equipment CME-75 Truck Rig Driller Western States Bridge No. 00962A Project Geologist Cody K. Sorensen, CEG Recorder Seth Sonnier Ground Elev. ~ 169 ft. Start DateNovember 21, 2016 End Date November 22, 2016 Total Depth 100.60 ft Tube Height N/A Test Type Rock Abbreviations Typical Drilling Abbreviations "A" - Auger Core "GP" - GeoProbe® Discontinuity Shape Surface Roughness Drilling Methods Drilling Remarks WL - Wire Line LW - Lost Water "X" - Auger J - Joint Pl - Planar P - Polished HS - Hollow Stem Auger WR - Water Return "C" - Core, Barrel Type F - Fault C - Curved Sl - Slickensided DF - Drill Fluid WC - Water Color "N" - Standard Penetration B - Bedding U - Undulating Sm - Smooth SA - Solid Auger DP - Down Pressure "U" - Undisturbed Sample Fo - Foliation St - Stepped R - Rough CA - Casing Advancer DR - Drill Rate "T" - Test Pit S - Shear Ir - Irregular VR - Very Rough HA - Hand Auger DA - Drill Action

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 0 0.00 - 1.20 Mud rotary drilling Asphalt Concrete; technique (5-inch hole) (Fill) 1.20 - 2.10 Base Aggregate; (Fill) Dynamic Cone 2.10 - 3.50 Penetrometer Test N1A 100 3-4-24 28 N- 1A (2.50-3.50) SILT with trace sand; ML; Brown; Low SILT with trace sand; performed at 1.7 ft plasticity; Moist; Very Stiff; Fine sand; Micaceous; (Fill) ML; Brown; Low N1B N- 1B (3.50-4.00) Silty GRAVEL with some sand; GM; plasticity; Moist; Very Brown; Low plasticity fines; Moist; Medium Dense; Fine to Stiff; Fine sand; coarse, angular to rounded gravel; Fine to coarse sand; Micaceous; (Fill) (Fill) 3.50 - 4.50 5 N2 100 4-4-3 N- 2 (5.00-6.50) SILT with some gravel and trace sand; Silty GRAVEL with ML; Brown; Low plasticity; Moist; Medium Stiff; Fine to some sand; GM; coarse subrounded gravel; Fine to coarse sand; Trace organics; (Fill) Brown; Low plasticity fines; Moist; Medium Dense; Fine to coarse, angular to N3 67 3-2-3 25 N- 3 (7.50-9.00) SILT with trace gravel and trace sand; rounded gravel; Fine ML; Brown; Nonplastic to Low plasticity; Moist; Medium to coarse sand; (Fill) Stiff; Fine to coarse subrounded gravel; Fine to coarse sand; (Missoula Flood Deposits - Fine) 4.50 - 7.00 SILT with some gravel and trace sand; ML; Brown; 10 N4 87 1-1-2 N- 4 (10.00-11.50) SILT with some sand; ML; Brown; Nonplastic to Low Nonplastic to Low plasticity; Moist; Soft; Fine sand; plasticity; Moist; Micaceous; (Missoula Flood Deposits - Fine) Medium Stiff; Fine to coarse subrounded gravel; Fine to coarse sand; (Fill) 7.00 - 9.50 SILT with trace gravel and trace sand; ML; Brown; Nonplastic to Low plasticity; Moist; Medium Stiff; Fine to 15 coarse subrounded N5 100 0-0-0 33 N- 5 (15.00-16.50) Silty CLAY; CL; Blue-gray; Medium gravel; Fine to coarse N5: LL=43, PL=25, plasticity; Moist; Very Soft; Trace organics; (Missoula PI=18 Flood Deposits - Fine) sand; (Missoula Flood Deposits - Fine) 9.50 - 12.50 SILT with some sand; ML; Brown; Nonplastic to Low U1 100 U- 1 (18.00-20.00) Silty CLAY; CL; Blue-gray; Medium plasticity; Moist; Soft; plasticity; Moist; Very Soft; Trace organics; (Missoula Fine sand; Flood Deposits - Fine) Micaceous; (Missoula Flood Deposits - Fine) 20 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 Figure A2 Project Name Silverton Road: Little Pudding River Bridge Hole No. B-2 Page2 of 4

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 20 N6 100 0-0-0 N- 6 (20.00-21.50) Silty CLAY; CL; Blue-gray; Medium 12.50 - 23.00 plasticity; Moist; Very Soft; Trace organics; (Missoula Silty CLAY; CL; Flood Deposits - Fine) Blue-gray; Medium plasticity; Moist; Very Soft; Trace organics; (Missoula Flood Deposits - Fine) 23.00 - 27.50 CLAY; CH; Blue-gray; High plasticity; Moist; Medium Stiff; Trace organics; (Missoula 25 N7 100 1-3-4 N- 7 (25.00-26.50) CLAY; CH; Blue-gray; High plasticity; Flood Deposits - Fine) Moist; Medium Stiff; Trace organics; (Missoula Flood Deposits - Fine)

27.50 - 37.50 Silty CLAY; CL; Blue-gray; Medium plasticity; Moist; Very Soft to Medium Stiff; Trace organics; 30 N8 100 0-0-1 40 N- 8 (30.00-31.50) Silty CLAY; CL; Blue-gray; Medium Micaceous; (Missoula N8: LL=49, PL=26, plasticity; Moist; Very Soft; Trace organics; (Missoula Flood Deposits - Fine) PI=23 Flood Deposits - Fine)

11/21/16

Observed during drilling.

35 N9 100 1-3-4 N- 9 (35.00-36.50) Silty CLAY; CL; Blue-gray; Medium plasticity; Moist; Medium Stiff; Micaceous; (Missoula Flood Deposits - Fine)

37.50 - 41.50 Sandy SILT with trace gravel; ML; Blue-gray; Low plasticity; Wet; Stiff; Stratified with 1 to 40 N10 100 1-3-7 30 N- 10 (40.00-41.50) Sandy SILT with trace gravel; ML; 3-inch thick interbeds Blue-gray; Low plasticity; Wet; Stiff; Stratified with 1 to of SILT (ML); 3-inch thick interbeds of SILT (ML); Micaceous; (Missoula Micaceous; (Missoula Flood Deposits - Fine) Flood Deposits - Fine) 41.50 - 47.50 Silty SAND with trace gravel; SM; Brown; Nonplastic fines; Wet; Dense; Fine to coarse rounded gravel; Fine to coarse sand; (Pleistocene 45 Sand and Gravel) N11 100 12-18-20 N- 11 (45.00-46.50) Silty SAND with trace gravel; SM; Brown; Nonplastic fines; Wet; Dense; Fine to coarse rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

47.50 - 57.50 Sandy GRAVEL with some silt; GW-GM; Brown; Nonplastic fines; Moist; Very 50 Dense; Fine to ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 Figure A2 Project Name Silverton Road: Little Pudding River Bridge Hole No. B-2 Page3 of 4

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 50 N12 100 50/1st 6" N- 12 (50.00-50.50) Sandy GRAVEL with some silt; coarse, subangular to GW-GM; Brown; Nonplastic fines; Moist; Very Dense; subrounded gravel; Fine to coarse, subangular to subrounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel) Fine to coarse sand; (Pleistocene Sand and Gravel)

55 N13 100 50/1st 5" N- 13 (55.00-55.40) Sandy GRAVEL with some silt; GW-GM; Brown; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to subrounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

57.50 - 68.00 Sandy GRAVEL with some silt; GW-GM; Brown; Nonplastic fines; Moist; Very Dense; Fine to 60 N14 100 39-50/6" N- 14 (60.00-61.00) Sandy GRAVEL with some silt; coarse, subangular to GW-GM; Brown; Nonplastic fines; Moist; Very Dense; rounded gravel; Fine Fine to coarse, subangular to rounded gravel; Fine to to coarse sand; Slight coarse sand; Slight to moderate iron oxidation and staining; Highly varied gravel clast composition; to moderate iron (Pleistocene Sand and Gravel) oxidation and staining; Highly varied gravel clast composition; (Pleistocene Sand and Gravel)

65 N15 90 50/1st 5" N- 15 (65.00-65.40) Sandy GRAVEL with some silt; GW-GM; Brown; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; Slight to moderate iron oxidation and staining; Highly varied gravel clast composition; (Pleistocene Sand and Gravel)

68.00 - 73.50 Small cobbles around 68 SILT with trace sand; feet, based on drill ML; Gray-brown; action Nonplastic; Moist; Very Dense; Fine to 70 N16 100 22-22-40 29 N- 16 (70.00-71.50) SILT with trace sand; ML; medium sand; Gray-brown; Nonplastic; Moist; Very Dense; Fine to (Pleistocene Sand medium sand; (Pleistocene Sand and Gravel) and Gravel)

73.50 - 83.00 Silty SAND with some gravel; SM; Brown; 75 Nonplastic fines; N17 100 16-20-50/4" N- 17 (75.00-76.30) Silty SAND with some gravel; SM; Moist; Very Dense; N17: 14.1% fines Brown; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse Fine to coarse, sand; (Pleistocene Sand and Gravel) subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

80 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 Figure A2 Project Name Silverton Road: Little Pudding River Bridge Hole No. B-2 Page4 of 4

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 80 N18 100 50/1st 3" N- 18 (80.00-80.25) Silty SAND with some gravel; SM; Brown; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

83.00 - 100.60 Sandy GRAVEL with some silt; GW-GM; Brown; Nonplastic fines; Moist; Very 85 N19 100 50/1st 3" N- 19 (85.00-85.25) Sandy GRAVEL with some silt; Dense; Fine to GW-GM; Brown; Nonplastic fines; Moist; Very Dense; coarse, subangular to Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel) rounded gravel; Fine to coarse sand; Weakly cemented below 90 feet; Slight iron oxidation and staining at 100 feet; (Pleistocene Sand and Gravel)

90 N20 100 30-47-50/5" N- 20 (90.00-91.40) Sandy GRAVEL with some silt; N20: 8.3% fines GW-GM; Brown; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; Weakly cemented; (Pleistocene Sand and Gravel)

95 N21 0 50/1st 2" N- 21 (95.00-95.20) Sandy GRAVEL with some silt; GW-GM; Brown; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; Weakly cemented; (Pleistocene Sand and Gravel)

100 N22 100 48-50/2" N- 22 (100.00-100.60) Sandy GRAVEL with some silt; GW-GM; Brown; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to 100.60 coarse sand; Weakly cemented; Slight iron oxidation and End of hole staining; (Pleistocene Sand and Gravel)

105

110 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants DRILL LOG Figure A3 OREGON DEPARTMENT OF TRANSPORTATION Page1 of 4 Hole No. B-3 Project Silverton Road: Little Pudding River Bridge Purpose Subsurface Exploration E.A. No. N/A Highway State Highway 213 County Marion Key No. N/A Hole Location Northing: ~ 237,621 Easting: ~ 203,298 Start Card No. N/A Equipment CME-75 Truck Rig Driller Western States Bridge No. 00962A Project Geologist Cody K. Sorensen, CEG Recorder Seth Sonnier Ground Elev. ~ 170 ft. Start DateNovember 28, 2016 End Date November 29, 2016 Total Depth 100.30 ft Tube Height N/A Test Type Rock Abbreviations Typical Drilling Abbreviations "A" - Auger Core "GP" - GeoProbe® Discontinuity Shape Surface Roughness Drilling Methods Drilling Remarks WL - Wire Line LW - Lost Water "X" - Auger J - Joint Pl - Planar P - Polished HS - Hollow Stem Auger WR - Water Return "C" - Core, Barrel Type F - Fault C - Curved Sl - Slickensided DF - Drill Fluid WC - Water Color "N" - Standard Penetration B - Bedding U - Undulating Sm - Smooth SA - Solid Auger DP - Down Pressure "U" - Undisturbed Sample Fo - Foliation St - Stepped R - Rough CA - Casing Advancer DR - Drill Rate "T" - Test Pit S - Shear Ir - Irregular VR - Very Rough HA - Hand Auger DA - Drill Action

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 0 0.00 - 1.20 Mud rotary drilling Asphalt Concrete; technique (5-inch hole) (Fill) 1.20 - 2.00 Dynamic Cone Base Aggregate; (Fill) Penetrometer Test 2.00 - 4.50 performed at 1.25 ft N1 67 1-3-5 N- 1 (2.50-4.00) SILT with some gravel and trace sand; SILT with some ML; Brown; Nonplastic to low plasticity; Moist; Medium Stiff; Fine to coarse, angular to rounded gravel; Fine to gravel and trace coarse sand; Micaceous; (Fill) sand; ML; Brown; Nonplastic to low plasticity; Moist; Medium Stiff; Fine to 5 N2 67 2-2-2 33 N- 2 (5.00-6.50) SILT; ML; Brown; Low plasticity; Moist; coarse, angular to Soft to Medium Stiff; Micaceous; (Missoula Flood rounded gravel; Fine Deposits - Fine) to coarse sand; (Fill) 4.50 - 11.00 SILT; ML; Brown to brown mottled dark N3 100 0-2-2 N- 3 (7.50-9.00) SILT; ML; Brown; Low plasticity; Moist; brown; Low Soft to Medium Stiff; Trace fine fibrous organics; plasticity; Moist; Very Micaceous; (Missoula Flood Deposits - Fine) Soft to Medium Stiff;Trace fine fibrous organics; Moderate iron oxide 10 N4 100 0-0-0 29 N- 4 (10.00-11.50) SILT; ML; Brown mottled dark brown; staining at 10 feet; Low plasticity; Moist; Very Soft; Trace organics; Moderate Micaceous; (Missoula iron oxide staining; Micaceous; (Missoula Flood Deposits Flood Deposits - Fine) - Fine) 11.00 - 17.50 N4: LL=30, PL=23, PI=7 SILT; ML; Blue-gray; Low plasticity; Moist; Stiff; Trace organics; Micaceous; (Missoula Flood Deposits - Fine)

15 N5 100 0-4-6 N- 5 (15.00-16.50) SILT; ML; Blue-gray; Low plasticity; Moist; Stiff; Trace organics; Micaceous; (Missoula Flood Deposits - Fine)

11/28/17

17.50 - 22.50 Observed during drilling. SILT with some sand; ML; Light brown; Low plasticity; Moist; Soft to Medium Stiff; Fine 20 sand; Slight iron ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 Figure A3 Project Name Silverton Road: Little Pudding River Bridge Hole No. B-3 Page2 of 4

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 20 N6 100 1-2-2 33 N- 6 (20.00-21.50) SILT with some sand; ML; Light oxidation and brown; Low plasticity; Moist; Soft to Medium Stiff; Fine staining; (Missoula sand; Slight iron oxide staining; (Missoula Flood Deposits - Fine) Flood Deposits - Fine)

22.50 - 33.00 U1 100 U- 1 (23.00-25.00) SILT; ML; Light brown; Low plasticity; SILT; ML; Light Moist; Slight iron oxide staining; (Missoula Flood Deposits brown; Nonplastic to - Fine) low plasticity; Moist; Medium Stiff; Slight iron oxide staining; 25 N7 100 3-4-3 37 N- 7 (25.00-26.50) SILT; ML; Light brown; Low plasticity; Micaceous; (Missoula Moist; Medium Stiff; Micaceous; (Missoula Flood Flood Deposits - Fine) Deposits - Fine)

30 N8 100 3-6-5 N- 8 (30.00-31.50) SILT; ML; Light brown; Nonplastic to Low plasticity; Moist; Medium Stiff; Micaceous; (Missoula Flood Deposits - Fine)

33.00 - 42.50 SILT with some sand; ML; Dark gray to dark brown; Nonplastic to Low plasticity; Moist; 35 N9 100 9-13-20 N- 9 (35.00-36.50) SILT with some sand; ML; Dark gray; Very stiff to hard; Nonplastic to Low plasticity; Moist; Hard; Fine sand; Fine sand; Micaceous; (Missoula Flood Deposits - Fine) Micaceous; (Missoula Flood Deposits - Fine)

40 N10 100 8-12-15 38 N- 10 (40.00-41.50) SILT with some sand; ML; Dark brown; Nonplastic to Low plasticity; Moist; Very Stiff; Fine sand; Micaceous; (Missoula Flood Deposits - Fine)

42.50 - 49.00 Silty SAND; SM; Brown; Low plasticity fines; Moist; Dense; Fine to medium sand; (Pleistocene Sand 45 N11 100 12-18-28 N- 11 (45.00-46.50) Silty SAND; SM; Brown; Low and Gravel) plasticity fines; Moist; Dense; Fine to medium sand; (Pleistocene Sand and Gravel)

49.00 - 67.50 Sandy GRAVEL with 50 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 Figure A3 Project Name Silverton Road: Little Pudding River Bridge Hole No. B-3 Page3 of 4

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 50 N12 80 50/1st 5" N- 12 (50.00-50.40) Sandy GRAVEL with some silt; some silt; GW-GM; GW-GM; Brown to gray; Nonplastic fines; Moist; Very Brown to gray; Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; Slight iron oxidation and staining; Nonplastic fines; (Pleistocene Sand and Gravel) Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

55 N13 80 50/1st 5" N- 13 (55.00-55.40) Sandy GRAVEL with some silt; N13: 6.0% fines GW-GM; Brown to gray; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

60 N14 100 50/1st 4" N- 14 (60.00-60.30) Sandy GRAVEL with some silt; GW-GM; Brown to gray; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

65 N15 100 50/1st 5" N- 15 (65.00-65.40) Sandy GRAVEL with some silt; GW-GM; Brown to gray; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

67.50 - 75.50 SILT with some sand; ML; Blue-gray to brown; Nonplastic; Moist; Very Dense; Fine to medium sand; 70 N16 100 23-25-40 31 N- 16 (70.00-71.50) SILT with some sand; ML; Blue-gray (Pleistocene Sand to brown; Nonplastic; Moist; Very Dense; Fine to medium and Gravel) sand; (Pleistocene Sand and Gravel)

75 N17A 100 15-50/4" N- 17A (75.00-75.50) SILT with some sand; ML; Blue-gray to brown; Nonplastic; Moist; Very Dense; Fine N17B to medium sand 75.50 - 80.00 N- 17B (75.50-75.80) Silty Sandy GRAVEL; GM; Brown; Silty Sandy GRAVEL; Nonplastic fines; Moist; Very Dense; Fine to coarse GM; Brown; subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel) Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand 80 and Gravel) ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 Figure A3 Project Name Silverton Road: Little Pudding River Bridge Hole No. B-3 Page4 of 4

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 80 N18 100 50/1st 4" N- 18 (80.00-80.30) Sandy GRAVEL with some silt; 80.00 - 88.00 GW-GM; Brown to gray; Low plasticity fines; Moist; Very Sandy GRAVEL with Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel) some silt; GW-GM; Brown to gray; Low plasticity fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel) 85 N19 100 50/1st 3" N- 19 (85.00-85.25) Sandy GRAVEL with some silt; GW-GM; Brown to gray; Low plasticity fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

88.00 - 100.30 Sandy GRAVEL with some silt; GW-GM; Brown to gray; Low plasticity fines; 90 N20 100 50/1st 4" N- 20 (90.00-90.30) Sandy GRAVEL with some silt; Moist; Very Dense; GW-GM; Brown to gray; Nonplastic fines; Moist; Very Fine to coarse, Dense; Fine to coarse subangular to rounded gravel; Fine to coarse sand; Slight iron oxidation and staining; subangular to (Pleistocene Sand and Gravel) rounded gravel; Fine to coarse sand; Slight iron oxidation and staining; (Pleistocene Sand and Gravel)

95 N21 100 50/1st 3" N- 21 (95.00-95.25) Sandy GRAVEL with some silt; GW-GM; Brown to gray; Nonplastic fines; Moist; Very Dense; Fine to coarse subangular to rounded gravel; Fine to coarse sand; Slight iron oxidation and staining; (Pleistocene Sand and Gravel)

100 N22 100 50/1st 4" N- 22 (100.00-100.30) Sandy GRAVEL with some silt; GW-GM; Brown to gray; Nonplastic fines; Moist; Very 100.30 Dense; Fine to coarse subangular to rounded gravel; Fine End of hole to coarse sand; Slight iron oxidation and staining; (Pleistocene Sand and Gravel)

105

110 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants DRILL LOG Figure A4 OREGON DEPARTMENT OF TRANSPORTATION Page1 of 3 Hole No. B-4 Project Silverton Road: Little Pudding River Bridge Purpose Subsurface Exploration E.A. No. N/A Highway State Highway 213 County Marion Key No. N/A Hole Location Northing: ~ 237,664 Easting: ~ 203,377 Start Card No. N/A Equipment CME-75 Truck Rig Driller Western States Bridge No. 00962A Project Geologist Cody K. Sorensen, CEG Recorder Seth Sonnier Ground Elev. ~ 173 ft. Start DateNovember 29, 2016 End Date November 29, 2016 Total Depth 60.25 ft Tube Height N/A Test Type Rock Abbreviations Typical Drilling Abbreviations "A" - Auger Core "GP" - GeoProbe® Discontinuity Shape Surface Roughness Drilling Methods Drilling Remarks WL - Wire Line LW - Lost Water "X" - Auger J - Joint Pl - Planar P - Polished HS - Hollow Stem Auger WR - Water Return "C" - Core, Barrel Type F - Fault C - Curved Sl - Slickensided DF - Drill Fluid WC - Water Color "N" - Standard Penetration B - Bedding U - Undulating Sm - Smooth SA - Solid Auger DP - Down Pressure "U" - Undisturbed Sample Fo - Foliation St - Stepped R - Rough CA - Casing Advancer DR - Drill Rate "T" - Test Pit S - Shear Ir - Irregular VR - Very Rough HA - Hand Auger DA - Drill Action

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 0 0.00 - 1.00 Mud rotary drilling Asphalt Concrete; technique (5-inch hole) (Fill) Dynamic Cone 1.00 - 2.00 Penetrometer Test Base Aggregate; (Fill) performed at 1.0 ft 2.00 - 4.00 N1 67 4-4-6 32 N- 1 (2.50-4.00) SILT with some sand; ML; Light brown; SILT with some sand; Low plasticity; Moist; Stiff; Fine sand; Micaceous; (Fill) ML; Light brown; Low plasticity; Moist; Stiff; Fine sand; Micaceous; (Fill) 11/29/17 4.00 - 9.50 5 N2 100 3-2-5 N- 2 (5.00-6.50) SILT; ML; Light brown; Nonplastic; Moist SILT; ML; Light Observed during drilling. to wet; Loose; Micaceous; (Missoula Flood Deposits - brown; Nonplastic to Fine) low plasticity; Moist to wet; Loose/Medium stiff; Micaceous; (Missoula Flood N3 47 3-2-5 N- 3 (7.50-9.00) SILT; ML; Light brown; Nonplastic to low Deposits - Fine) plasticity; Moist to wet; Medium Stiff; Micaceous; (Missoula Flood Deposits - Fine)

9.50 - 18.00 10 N4 67 2-4-3 39 N- 4 (10.00-11.50) SILT with trace sand; ML; Light SILT with trace sand; brown; Nonplastic; Wet; Loose; Fine sand; Micaceous; ML; Light brown; (Missoula Flood Deposits - Fine) Nonplastic; Wet; Loose to Medium Dense; Fine sand; Micaceous; (Missoula Flood Deposits - Fine)

15 N5 100 4-6-8 N- 5 (15.00-16.50) SILT with trace sand; ML; Light brown; Nonplastic; Wet; Medium Dense; Fine sand; Micaceous; (Missoula Flood Deposits - Fine)

18.00 - 25.00 SILT with some sand; ML; Light brown; Nonplastic; Wet; 20 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 Medium Dense; Fine REV 3 Figure A4 Project Name Silverton Road: Little Pudding River Bridge Hole No. B-4 Page2 of 3

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 20 N6 100 2-3-7 32 N- 6 (20.00-21.50) SILT with some sand; ML; Light sand; Micaceous; brown; Nonplastic; Wet; Medium Dense; Fine sand; (Missoula Flood Micaceous; (Missoula Flood Deposits - Fine) Deposits - Fine)

25 N7 100 4-6-8 N- 7 (25.00-26.50) SILT with trace sand; ML; Light 25.00 - 32.50 brown; Nonplastic; Wet; Medium Dense; Fine sand; SILT with trace sand; Micaceous; (Missoula Flood Deposits - Fine) ML; Light brown; Nonplastic to low plasticity; Wet; Stiff to Medium Dense; Fine sand; Micaceous; (Missoula Flood Deposits - Fine)

30 N8 100 4-4-5 N- 8 (30.00-31.50) SILT with trace sand; ML; Light brown; Nonplastic to low plasticity; Wet; Stiff; Fine sand; Micaceous; (Missoula Flood Deposits - Fine)

32.50 - 41.00 SILT with trace sand; ML; Light brown to blue-gray; Nonplastic to low plasticity; Wet; Very Stiff; Fine sand; 35 N9 100 6-10-9 32 N- 9 (35.00-36.50) SILT with trace sand; ML; Light brown Slight iron oxide to blue-gray; Nonplastic to low plasticity; Wet; Very Stiff; staining; Micaceous; Fine sand; Micaceous; Slight iron oxide staining; (Missoula Flood (Missoula Flood Deposits - Fine) Deposits - Fine)

40 N10A 100 3-6-13 N- 10A (40.00-41.00) SILT with trace sand; ML; Light brown to blue-gray; Nonplastic to low plasticity; Wet; Very Stiff; Fine sand; Slight iron oxide staining; Micaceous; N10B (Missoula Flood Deposits - Fine) 41.00 - 44.00 N- 10B (41.00-41.50) SAND with some silt; SP-SM; Brown; Nonplastic fines; Moist; Medium Dense; Fine to SAND with some silt; medium sand; (Pleistocene Sand and Gravel) SP-SM; Brown; Nonplastic fines; Moist; Medium Dense; Fine to medium sand; (Pleistocene Sand and Gravel) 45 44.00 - 48.00 N11 100 11-18-23 34 N- 11 (45.00-46.50) Sandy SILT; ML; Brown mottled Sandy SILT; ML; orange-brown; Nonplastic; Moist; Dense; Fine to coarse sand; (Pleistocene Sand and Gravel) Brown mottled orange-brown; Nonplastic; Moist; Dense; Fine to coarse sand; (Pleistocene Sand and Gravel) 48.00 - 53.50 Silty SAND; SM; Brown; Nonplastic fines; Moist; Very 50 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 Dense; Fine to REV 3 Figure A4 Project Name Silverton Road: Little Pudding River Bridge Hole No. B-4 Page3 of 3

Soil Rock Material Description Unit Description SOIL: Soil Name, USCS, Color, Plasticity, Moisture, Consistency/Relative Density, Texture, Cementation, Structure, Origin. ROCK: Rock Name, Color, Weathering, Hardness, Discontinuity Spacing, Joint Filling, Core Recovery, Formation Name. Depth (ft) Test Type, No. Percent Recovery Driving Resistance Discontinuity Data Or RQD% Percent Natural Moisture Graphic Log Drilling Methods, Size and Remarks Water Level/ Date Backfill/ Instrumentation 50 N12 100 17-23-38 N- 12 (50.00-51.50) Silty SAND; SM; Brown; Nonplastic medium sand; fines; Moist; Very Dense; Fine to medium sand; Stratified Stratified with thin with thin interbeds of SAND with some silt (SP-SM); (Pleistocene Sand and Gravel) interbeds of SAND with some silt (SP-SM); (Pleistocene Sand and Gravel)

53.50 - 60.25 Sandy GRAVEL with some silt; GW-GM; 55 Brown to gray; N13 100 40-50/3" N- 13 (55.00-55.75) Sandy GRAVEL with some silt; Nonplastic fines; GW-GM; Brown to gray; Nonplastic fines; Moist; Very Dense; Fine to coarse, subangular to rounded gravel; Moist; Very Dense; Fine to coarse sand; (Pleistocene Sand and Gravel) Fine to coarse, subangular to rounded gravel; Fine to coarse sand; (Pleistocene Sand and Gravel)

60 N14 100 50/1st 3" N- 14 (60.00-60.25) Sandy GRAVEL with some silt; GW-GM; Brown to gray; Nonplastic fines; Moist; Very 60.25 Dense; Fine to coarse, subangular to rounded gravel; End of hole Fine to coarse sand; (Pleistocene Sand and Gravel)

65

70

75

80 ODOT DRILL LOG - FOR SW FOR REVIEW ODOT_MANWITHSWLAB.GDTODOT DRILL LOG - 24-1-04094.GPJ 11/6/18 REV 3 DCP TEST DATA

Project: Little Pudding River Br Date: 23-Nov-16 Location: B-1 Soil Type(s): ML

Hammer 10.1 lbs. CH 17.6 lbs. CL Both hammers used All other soils

No. of Accumulative Type of SUBGRADE MODULUS (MR) psi Blows Penetration Hammer 1000.0 10000.0 100000.0 (mm) 0 0 0 494 1 5 546 1 5 127 5 598 1 10 254 5 608 1 5 619 1 15 381 5 626 1 5 638 1 20 508 5 645 1 25 635 5 652 1

5 661 1 30 762

5 671 1 in. DEPTH, DEPTH, mm DEPTH, 5 690 1 35 889 5 719 1 40 1016 5 741 1 5 757 1 45 1143 5 769 1 5 780 1 50 1270 5 798 1 5 816 1 55 1397 1000.0 10000.0 100000.0 5 835 1 5 861 1 CORRECTED SUBGRADE MODULUS (MR) psi 5 902 1 1000.0 10000.0 100000.0 5 936 1 0 0 5 969 1 5 127 5 1001 1 5 1048 1 10 254 5 1107 1 5 1169 1 15 381 5 1252 1 5 1327 1 20 508

25 635

30 762 DEPTH, in. DEPTH, DEPTH, mm DEPTH, 35 889

40 1016

45 Based on approximate 1143 interrelationships of MR (ODOT PAVEMENT DESIGN GUIDE 50 2011) 1270

55 1397 1000.0 10000.0 100000.0

REV 3 Figure A5 DCP TEST DATA

Project: Little Pudding River Br Date: 21-Nov-16 Location: B-2 Soil Type(s): ML/GM

Hammer 10.1 lbs. CH 17.6 lbs. CL Both hammers used All other soils

No. of Accumulative Type of SUBGRADE MODULUS (MR) psi Blows Penetration Hammer 1000.0 10000.0 100000.0 (mm) 0 0 0 232 1 5 292 1 5 127 5 314 1 5 340 1 10 254 5 369 1 15 381 5 425 1 5 474 1 20 508 5 517 1 5 544 1 25 635 5 584 1

5 637 1 in. DEPTH,

30 762 mm DEPTH, 5 704 1 5 739 1 35 889 5 752 1 5 762 1 40 1016 5 769 1 5 778 1 45 1143 5 785 1 5 794 1 50 1270 1000.0 10000.0 100000.0 5 798 1 10 809 1 CORRECTED SUBGRADE MODULUS (MR) psi 10 816 1 1000.0 10000.0 100000.0 10 823 1 0 0 10 830 1 10 839 1 5 127 10 851 1 10 254 5 857 1 5 865 1 15 381 5 872 1 5 881 1 20 508 5 889 1

5 898 1 25 635 5 908 1

5 918 1 in. DEPTH, 30 762 mm DEPTH, 5 931 1 5 947 1 35 889 5 967 1 5 988 1 40 1016 Based on approximate 5 1018 1 interrelationships of MR (ODOT PAVEMENT DESIGN GUIDE 5 1057 1 45 2011) 1143 5 1101 1 5 1150 1 50 1270 1000.0 10000.0 100000.0

REV 3 Figure A6 DCP TEST DATA

Project: Little Pudding River Br Date: 23-Nov-16 Location: B-3 Soil Type(s): ML

Hammer 10.1 lbs. CH 17.6 lbs. CL Both hammers used All other soils

No. of Accumulative Type of SUBGRADE MODULUS (MR) psi Blows Penetration Hammer 1000.0 10000.0 100000.0 (mm) 0 0 0 481 1 5 127 5 491 1 5 495 1 10 254 5 499 1 5 501 1 15 381

5 504 1 20 508 5 507 1 5 513 1 25 635 5 518 1 30 762 5 524 1

5 537 1 in. DEPTH, 35 889 DEPTH, mm DEPTH, 5 552 1 40 1016 5 574 1 5 598 1 45 1143 5 616 1 50 1270 5 635 1

5 655 1 55 1397 5 717 1 5 815 1 60 1524 1000.0 10000.0 100000.0 5 919 1 5 1107 1 CORRECTED SUBGRADE MODULUS (MR) psi 5 1161 1 1000.0 10000.0 100000.0 5 1188 1 0 0 5 1216 1 5 127 5 1251 1 5 1332 1 10 254

15 381

20 508

25 635

30 762

DEPTH, in. DEPTH, 35 889 DEPTH, mm DEPTH,

40 1016

45 1143

50 Based on approximate 1270 interrelationships of MR (ODOT PAVEMENT DESIGN GUIDE 55 2011) 1397

60 1524 1000.0 10000.0 100000.0

REV 3 Figure A7 DCP TEST DATA

Project: Little Pudding River Br Date: 23-Nov-16 Location: B-4 Soil Type(s): ML

Hammer 10.1 lbs. CH 17.6 lbs. CL Both hammers used All other soils

No. of Accumulative Type of SUBGRADE MODULUS (MR) psi Blows Penetration Hammer 1000.0 10000.0 100000.0 (mm) 0 0 0 464 1 5 517 1 5 537 1 5 127 5 556 1 5 567 1

5 581 1 10 254 5 598 1 5 615 1 5 629 1 15 381 5 655 1

5 656 1 in. DEPTH, DEPTH, mm DEPTH,

20 508

25 635

30 762 1000.0 10000.0 100000.0

CORRECTED SUBGRADE MODULUS (MR) psi 1000.0 10000.0 100000.0 0 0

Based on approximate 5 interrelationships of MR (ODOT 127 PAVEMENT DESIGN GUIDE 2011)

10 254

15 381 DEPTH, in. DEPTH, DEPTH, mm DEPTH,

20 508

25 635

30 762 1000.0 10000.0 100000.0

REV 3 Figure A8 Silverton Road: Little Pudding River Bridge Replacement Geotechnical Engineering Report

Appendix B: Laboratory Testing Appendix B Laboratory Testing

CONTENTS . Grain Size Distribution . Atterberg Limits Results . Northwest Testing, Inc., Technical Report dated December 28, 2016 . Specialty Analytical Testing Report, Technical Report, dated January 10, 2017

BORATORY TESTING LA

APPENDIX B:APPENDIX

24-1-04094 November 27, 2018 B-i Silverton Road: Little Pudding River Bridge Replacement Geotechnical Engineering Report

APPENDIX B

B.1 GENERAL

Soil samples obtained during field explorations were examined in the laboratory. Physical characteristics of the samples were noted and field classifications were modified as necessary in accordance with the Oregon Department of Transportation (ODOT) Soil and Rock Classification Manual (ODOT, 1987). During the course of the examination, representative samples were selected for further testing. The soil-testing program included visual-manual classification and index property tests such as moisture content analyses, particle-size analyses, and Atterberg limits. These tests are described in the following paragraphs. All test procedures were performed in general accordance with applicable ASTM International standards. The term “general accordance” means that certain local and

common descriptive practices and methodologies have been followed.

B.2 SOIL TESTING B.2.1 Moisture (Natural Water) Content

Natural moisture content determinations were performed, in accordance with ASTM D2216, on selected soil samples. The natural moisture content is a measure of the amount of moisture in the soil at the time of exploration. It is defined as the ratio of the weight of water to the dry weight of the soil, expressed as a percentage. The results of moisture content determinations are presented in the boring logs in Appendix A. LABORATORY TESTING LABORATORY

B.2.2 Particle Size Analysis

Particle-size analyses were conducted to determine the grain size distribution. Grain size distributions were determined by sieve analysis in accordance with ASTM C117/C136. Results of the particle-size analyses are presented in Figure B1, Grain Size Distribution. For all particle-size analyses, the percentage of material passing the No. 200 (0.075 mm) sieve is

APPENDIX B:APPENDIX also presented in the boring logs in Appendix A.

B.2.3 Atterberg Limits

Atterberg limits were determined in accordance with ASTM D4318. This analysis yields index parameters of the soil that are useful in soil classification as well as engineering analyses. Atterberg limit tests include liquid and plastic limits. The results are plotted on Figure B2, Atterberg Limits Results, and are also presented in the boring logs in Appendix A.

24-1-04094 November 27, 2018 B-1 Silverton Road: Little Pudding River Bridge Replacement Geotechnical Engineering Report

B.2.4 Corrosivity Testing

Analytical testing was performed on a composite sample of specimens from boring B-2 and B-3 to evaluate the corrosivity potential of the soil at the site. The corrosivity test suite included resistivity, chloride concentration, soil pH, sulfide concentration and sulfate concentration. An analytical testing report, prepared by Specialty Analytical, is attached to the end of this appendix.

The corrosion potential of a soil is primarily evaluated by comparing measured pH, resistivity, and sulfate and chloride concentrations to the values specified in Section 10.7.5 of the AASHTO LFRD Bridge Design Specifications (6th Edition 2012).

Soil pH is a measurement of the hydrogen ion activity of the soil. Soil pH is reported in Standard Units (S.U.) on a scale ranging from 0 to 14, with 7 being neutral. Soils with a pH less than 7 are considered acidic and soils with a pH greater than 7 are considered alkaline. According to the AASHTO specifications, soils with a pH less than 5.5 and soils with a pH between 5.5 and 8.5 that also have high organic content are considered potentially corrosive. Soil pH of the tested sample was 8.02. Trace organics were observed in the sample from boring B-3. However; the organic content was considered trace or less than 5% by volume and is not considered to be a high organic content value. Organic matter observed in the tested sample was in trace amounts therefore, based on pH the sample does not appear to be corrosive.

LABORATORY TESTING LABORATORY Resistivity (expressed as ohms-centimeter or ohms-cm) is the numerical expression of the

ability of a soil to impede the transmission of an electrical current. Resistivity is the inverse of conductivity and is dependent on the presence of ions, their concentrations, mobility, and valence, as well as soil moisture and temperature. The AASHTO specifications state that effects of corrosion and deterioration shall be considered if resistivity values are less than 2,000 ohms-cm. The resistivity of the tested sample was 2,300 ohms-cm. Based on the

APPENDIX B:APPENDIX resistivity value of the sample being greater than 2,00 ohms-cm, it is our opinion the sample does not appear to be corrosive.

Sulfate and chloride concentrations were also measured in the soil sample. Sulfates can be converted to sulfides by naturally occurring bacteria. Sulfides, when allowed to oxidize, will produce sulfuric acid, which is highly corrosive. Chlorides will also chemically react and facilitate dissolution reactions with metals and concrete. According to the AASHTO specifications, the soil is considered corrosive if the concentration of sulfate is greater than 1,000 parts per million (ppm) or the concentration of chloride is greater than 500 ppm. Sulfate and chloride concentrations in the tested sample were 26.5 and 3.30 ppm,

24-1-04094 November 27, 2018 B-2 Silverton Road: Little Pudding River Bridge Replacement Geotechnical Engineering Report

respectively. Based on the sulfate and chloride concentrations, the sample does not appear to be corrosive.

LABORATORY TESTING LABORATORY

APPENDIX B:APPENDIX

24-1-04094 November 27, 2018 B-3 GSA_MAIN 24-1-04094.GPJ SHAN_WIL.GDT 11/6/18 24-1-04094.GPJGSA_MAIN SHAN_WIL.GDT ASTM D2487 where appropriate laboratory tests performed. are laboratory appropriate where ASTM D2487 with in accordance withrefined are ASTM and are in accordance Symbol D2488 Group Name and Group 2) with accordance ASTM unless otherwise noted in the report. D1140 in general performed sieve were analyses with than #200 finer accordance ASTM amount D422, and in general were performed with accordance ASTM sieve withD6913, analyses in general hydrometer Sieve were analyses 1) performed NOTES: SIEVE ANALYSIS HYDROMETER ANALYSIS SIZE OF MESH OPENING IN INCHES NO. OF MESH OPENINGS PER INCH, U.S. STANDARD GRAIN SIZE IN MILLIMETERS .001 20 12 6 4 3 2 1 1/2 1 3/4 5/8 1/2 3/8 1/4 4 10 40 60 100 200 .06 .04 .03 .02 .01 .008 .006 .004 .003 .002 100 0

90 10

80 20 PERCENT COARSER BY WEIGHT

70 30

60 40

50 50

40 60 PERCENT FINER BY WEIGHT BY FINER PERCENT

30 70

20 80

10 90

0 100 8 6 4 3 2 1 .8 .6 .4 .3 .2 .1 80 60 40 30 20 10 .08 .06 .04 .03 .02 .01 300 200 100 .001 .008 .006 .004 .003 .002 GRAIN SIZE IN MILLIMETERS

COARSE FINE COARSE MEDIUM FINE COBBLES FINES: SILT OR CLAY GRAVEL SAND

DRY BORING AND DEPTH GROUP GROUP GRAVEL SAND FINES NAT. 2 2 DENSITY SAMPLE NO. (feet) SYMBOL NAME % % % W.C. % Silverton Road: Little Pudding River Bridge PCF Marion County, Oregon B-1, N11 45.0 GW-GM Sandy GRAVEL with some Silt - 38 8 B-2, N17 75.0 SM Silty SAND with some Gravel 15 71 14 B-2, N20 90.0 GW-GM Sandy GRAVEL with some Silt 55 37 8 GRAIN SIZE DISTRIBUTION

FIG. B1 B-3, N13 55.0 GW-GM Sandy GRAVEL with some Silt 65 29 6

November 2018 24-1-04094-001 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants FIG. B1 ATT_MAIN 24-1-04094.GPJ 11/6/18 SHAN_WIL.GDT

70

60

CH

50

NOTES CL 1) Atterberg limits tests were performed in general accordance 40 with ASTM D4318 unless otherwise noted in the report.

2) Group Name and Group Symbol are in accordance with ASTM D2488 and are refined in 30 accordance with ASTM D2487 where appropriate laboratory PLASTICITY INDEX - PI (%) - PI INDEX PLASTICITY tests are performed.

3) Plasticity adjectives used in sample descriptions correspond 20 to plasticity index as follows: - Nonplastic (NP) (< 3%) MH or OH - Low Plasticity (3 to 15%) - Medium Plasticity (15 to 30%) - High Plasticity (> 30%) 10

CL-ML ML or OL

0 0 10 20 30 40 50 60 70 80 90 100 110 LIQUID LIMIT - LL (%)

BORING AND DEPTH GROUP GROUP LL PL PI NAT. FINES SAMPLE NO. (feet) SYMBOL2 NAME2 % % %3 W.C. % % Silverton Road: Little Pudding River Bridge Marion County, Oregon B-1, N5 15.0 ML SILT 37 25 12 B-2, N5 15.0 CL Silty CLAY 43 25 18 B-2, N8 30.0 CL Silty CLAY 49 26 23 ATTERBERG LIMITS RESULTS B-3, N4 10.0 ML SILT 30 23 7 FIG. B2 B-3, N7 25.0 ML SILT 30 27 3 37 November 2018 24-1-04094-001 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants FIG. B2

TECHNICAL REPORT

Report To: Ms. Aimee Holmes, P.E., C.E.G. Date: 12/28/16 Shannon & Wilson, Inc. 3990 S.W. Collins Way, Suite 203 Lab No.: 16-321 Lake Oswego, Oregon 97035

Project: Laboratory Testing – 24-1-04094-001 Project No.: 2966.1.1 1

Report of: Moisture content, sieve analysis, and Atterberg limits

Sample Identification NTI completed moisture content, sieve analysis, and Atterberg limits testing on samples delivered to our laboratory on December 16, 2016. Testing was performed in accordance with the standards indicated. Our laboratory test results are summarized on the following table and attached page.

Laboratory Testing

Atterberg Limits (ASTM D4318) Sample ID Liquid Limit Plastic Limit Plasticity Index B-1 N-5 @ 15 – 16.5 ft. 37 25 12 B-2 N-5 @ 15 – 16.5 ft. 43 25 18 B-2 N-8 @ 30 – 31.5 ft. 49 26 23 B-3 N-4 @ 11 – 11.5 ft. 30 23 7

Attachments: Laboratory Test Results

Copies: Addressee

This report shall not be reproduced except in full, without written approval of Northwest Testing, Inc. SHEET 1 of 2 REVIEWED BY: Bridgett Adame TECHNICAL REPORT \\192.168.1.197\Laboratory\Lab Reports\2016 Lab Reports\2966.1.1 Shannon & Wilson\16-321 Moistures, SA, & Atterbergs.docx

TECHNICAL REPORT

Report To: Ms. Aimee Holmes, P.E., C.E.G. Date: 12/28/16 Shannon & Wilson, Inc. 3990 S.W. Collins Way, Suite 203 Lab No.: 16-321 Lake Oswego, Oregon 97035

Project: Laboratory Testing – 24-1-04094-001 Project No.: 2966.1.1 1

Laboratory Testing

Moisture Content of Soil (ASTM D 2216) Moisture Content Moisture Content Sample ID Sample ID (Percent) (Percent) B-1 N-1 @ 2.5 – 4 ft. 22.2 B-3 N-2 @ 5 – 6.5 ft. 32.5 B-1 N-3 @ 7.5 – 9 ft. 36.8 B-3 N-4 @ 11 – 11.5 ft. 29.0 B-1 N-5 @ 15 – 16.5 ft. 38.7 B-3 N-6 @ 20 – 21.5 ft. 32.5 B-1 N-8 @ 30 – 31.5 ft. 42.3 B-3 N-10 @ 40 – 41.5 ft. 37.6 B-2 N-1A @ 2.5 – 4 ft. 27.6 B-3 N-16 @ 70 – 71.5 ft. 30.7 B-2 N-3 @ 7.5 – 9 ft. 24.9 B-4 N-1 @ 2.5 – 4 ft. 31.6 B-2 N-5 @ 15 – 16.5 ft. 33.3 B-4 N-4 @ 10 – 11.5 ft. 39.2 B-2 N-8 @ 30 – 31.5 ft. 40.3 B-4 N-6 @ 20 – 21.5 ft. 32.3 B-2 N-10 @ 40 – 41.5ft. 29.5 B-4 N-9 @ 35 – 36.5 ft. 31.6 B-2 N-16 @ 70 – 71.5 ft. 28.9 B-4 N- 11 @ 45 – 46.5 ft. 33.9

Sieve Analysis of Aggregate (ASTM C117/C136) B-1 N-11 B-2 N- 17 B-2 N-20 B-3 N-13 Sieve @ 45 – 45.9 ft. @ 75 – 76.3 ft. @ 90 – 91.4 ft. @ 55 – 55.4 ft. Size Percent Passing Percent Passing Percent Passing Percent Passing 1 ½” 100 100 100 100 1” 100 100 100 85 ¾” 82 97 78 71 ½” 72 91 66 54 ⅜” 63 89 60 48 ¼” 52 86 51 40 #4 46 85 45 35 #8 35 84 35 27 #10 34 83 34 26 #16 30 82 28 22 #30 24 73 20 16 #40 21 59 17 14 #50 16 40 14 11 #100 11 21 11 8 #200 8.1 14.1 8.3 6.0

This report shall not be reproduced except in full, without written approval of Northwest Testing, Inc. SHEET 2 of 2 REVIEWED BY: Bridgett Adame TECHNICAL REPORT \\192.168.1.197\Laboratory\Lab Reports\2016 Lab Reports\2966.1.1 Shannon & Wilson\16-321 Moistures, SA, & Atterbergs.docx Specialty Analytical 11711 SE Capps Road, Ste B Clackamas, Oregon 97015 TEL: 503-607-1331 FAX: 503-607-1336 Website: www.specialtyanalytical.com

January 10, 2017

Stephen McLandrich Shannon & Wilson 3990 SW Collins Way Ste. 100 Lake Oswego, OR 97035 TEL: (503) 223-6147 FAX: (503) 223-6140 RE: Silverton Rd: Little Pudding BR Dear Stephen McLandrich: Order No.: 1612147

Specialty Analytical received 3 sample(s) on 12/16/2016 for the analyses presented in the following report.

There were no problems with the analysis and all data for associated QC met EPA or laboratory specifications, except where noted in the Case Narrative, or as qualified with flags. Results apply only to the samples analyzed. Without approval of the laboratory, the reproduction of this report is only permitted in its entirety.

If you have any questions regarding these tests, please feel free to call.

Sincerely,

Marty French Lab Director Specialty Analytical Date Reported: 10-Jan-17

CLIENT: Shannon & Wilson Collection Date: 11/28/2016 10:40:00 AM Project: Silverton Rd: Little Pudding BR Lab ID: 1612147-001 Client Sample ID: Composite B-2 & B-3 Matrix: SOIL

Analyses Result RL Qual Units DF Date Analyzed

OXIDATION-REDUCTION POTENTIAL ASTM D1498-08 Analyst: EFH Oxidation-Reduction Potential 197 0 Eh 1 12/20/2016 10:00:09 AM

WATER SOLUBLE CHLORIDE T291-94 Analyst: EFH Chloride 3.30 0.250 mg/Kg 1 12/22/2016 1:20:13 PM

PH OF SOIL-CORROSION TESTING T289-91 Analyst: EFH pH 8.02 0 pH Units 1 12/22/2016 9:05:00 AM

SOIL RESISTIVITY T288-91 Analyst: EFH Minimum Soil Resistivity 2300 1.00 ohm-cm 1 12/21/2016 11:20:21 AM

SULFIDE ION IN WATER ASTM D4658-09 Analyst: EFH Sulfide (As S) ND 10.0 mg/Kg 1 1/6/2017 11:10:00 AM

WATER SOLUBLE SULFATE ION T290-95 Analyst: EFH Sulfate 26.5 15.0 mg/Kg 1 12/23/2016 2:07:28 PM

Page 1 of 1 QC SUMMARY REPORT

WO#: 1612147 Specialty Analytical 10-Jan-17

Client: Shannon & Wilson Project: Silverton Rd: Little Pudding BR TestCode: CL_AASHTO

Sample ID: LCS-R19535 SampType: LCS TestCode: CL_AASHTO Units: mg/Kg Prep Date: RunNo: 19535 Client ID: LCSS Batch ID: R19535 TestNo: T291-94 Analysis Date: 12/22/2016 SeqNo: 260091

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Chloride 49.2 0.250 50.00 0 98.4 85 115

Sample ID: MB-R19535 SampType: MBLK TestCode: CL_AASHTO Units: mg/Kg Prep Date: RunNo: 19535 Client ID: PBS Batch ID: R19535 TestNo: T291-94 Analysis Date: 12/22/2016 SeqNo: 260092

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Chloride ND 0.250

Sample ID: R19535CCV SampType: CCV TestCode: CL_AASHTO Units: mg/Kg Prep Date: RunNo: 19535 Client ID: CCV Batch ID: R19535 TestNo: T291-94 Analysis Date: 12/22/2016 SeqNo: 260097

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Chloride 51.7 0.250 50.00 0 103 90 110

Sample ID: 1612102-003ADUP SampType: DUP TestCode: CL_AASHTO Units: mg/Kg Prep Date: RunNo: 19535 Client ID: ZZZZZZ Batch ID: R19535 TestNo: T291-94 Analysis Date: 12/22/2016 SeqNo: 260116

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Chloride 1.32 0.250 1.350 2.25 20

Qualifiers: B Analyte detected in the associated Method Blank H Holding times for preparation or analysis exceeded ND Not Detected at the Reporting Limit Page 1 of 4 O RSD is greater than RSDlimit R RPD outside accepted recovery limits S Spike Recovery outside accepted recovery limits QC SUMMARY REPORT

WO#: 1612147 Specialty Analytical 10-Jan-17

Client: Shannon & Wilson Project: Silverton Rd: Little Pudding BR TestCode: REDOX_D1498

Sample ID: 1612148-001ADUP SampType: DUP TestCode: REDOX_D149 Units: Eh Prep Date: RunNo: 19534 Client ID: ZZZZZZ Batch ID: R19534 TestNo: ASTM D1498- Analysis Date: 12/20/2016 SeqNo: 260090

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Oxidation-Reduction Potential 410 0 405.0 1.35 20

Qualifiers: B Analyte detected in the associated Method Blank H Holding times for preparation or analysis exceeded ND Not Detected at the Reporting Limit Page 2 of 4 O RSD is greater than RSDlimit R RPD outside accepted recovery limits S Spike Recovery outside accepted recovery limits QC SUMMARY REPORT

WO#: 1612147 Specialty Analytical 10-Jan-17

Client: Shannon & Wilson Project: Silverton Rd: Little Pudding BR TestCode: SULFIDE_ASTM

Sample ID: R19625CCV SampType: CCV TestCode: SULFIDE_AS Units: mg/Kg Prep Date: RunNo: 19625 Client ID: CCV Batch ID: R19625 TestNo: ASTM D4658- Analysis Date: 1/6/2017 SeqNo: 261725

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Sulfide (As S) 102 10.0

Sample ID: MB-R19625 SampType: MBLK TestCode: SULFIDE_AS Units: mg/Kg Prep Date: RunNo: 19625 Client ID: PBS Batch ID: R19625 TestNo: ASTM D4658- Analysis Date: 1/6/2017 SeqNo: 261726

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Sulfide (As S) ND 10.0

Sample ID: 1612147-001ADUP SampType: DUP TestCode: SULFIDE_AS Units: mg/Kg Prep Date: RunNo: 19625 Client ID: Composite B-2 & B- Batch ID: R19625 TestNo: ASTM D4658- Analysis Date: 1/6/2017 SeqNo: 261728

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Sulfide (As S) ND 10.0 0 0 20

Sample ID: R19625CCV SampType: CCV TestCode: SULFIDE_AS Units: mg/Kg Prep Date: RunNo: 19625 Client ID: CCV Batch ID: R19625 TestNo: ASTM D4658- Analysis Date: 1/6/2017 SeqNo: 261730

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Sulfide (As S) 105 10.0

Qualifiers: B Analyte detected in the associated Method Blank H Holding times for preparation or analysis exceeded ND Not Detected at the Reporting Limit Page 3 of 4 O RSD is greater than RSDlimit R RPD outside accepted recovery limits S Spike Recovery outside accepted recovery limits QC SUMMARY REPORT

WO#: 1612147 Specialty Analytical 10-Jan-17

Client: Shannon & Wilson Project: Silverton Rd: Little Pudding BR TestCode: T290_95

Sample ID: MB-R19517 SampType: MBLK TestCode: T290_95 Units: mg/Kg Prep Date: RunNo: 19517 Client ID: PBS Batch ID: R19517 TestNo: T290-95 Analysis Date: 12/23/2016 SeqNo: 259896

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Sulfate ND 15.0

Sample ID: LCS-R19517 SampType: LCS TestCode: T290_95 Units: mg/Kg Prep Date: RunNo: 19517 Client ID: LCSS Batch ID: R19517 TestNo: T290-95 Analysis Date: 12/23/2016 SeqNo: 259897

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Sulfate 156 15.0 150.0 0 104 80 120

Sample ID: LCSD-R19517 SampType: LCSD TestCode: T290_95 Units: mg/Kg Prep Date: RunNo: 19517 Client ID: LCSS02 Batch ID: R19517 TestNo: T290-95 Analysis Date: 12/23/2016 SeqNo: 259898

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Sulfate 155 15.0 150.0 0 103 80 120 155.7 0.623 20

Sample ID: 1612147-001ADUP SampType: DUP TestCode: T290_95 Units: mg/Kg Prep Date: RunNo: 19517 Client ID: Composite B-2 & B- Batch ID: R19517 TestNo: T290-95 Analysis Date: 12/23/2016 SeqNo: 259904

Analyte Result PQL SPK value SPK Ref Val %REC LowLimit HighLimit RPD Ref Val %RPD RPDLimit Qual

Sulfate 28.2 15.0 26.54 6.18 20

Qualifiers: B Analyte detected in the associated Method Blank H Holding times for preparation or analysis exceeded ND Not Detected at the Reporting Limit Page 4 of 4 O RSD is greater than RSDlimit R RPD outside accepted recovery limits S Spike Recovery outside accepted recovery limits KEY TO FLAGS Rev. May 12, 2010

AThis sample contains a Gasoline Range Organic not identified as a specific hydrocarbon product. The result was quantified against gasoline calibration standards

A1This sample contains a Diesel Range Organic not identified as a specific hydrocarbon product. The result was quantified against diesel calibration standards.

A2This sample contains a Lube Oil Range Organic not identified as a specific hydrocarbon product. The result was quantified against a lube oil calibration standard.

A3The result was determined to be Non-Detect based on hydrocarbon pattern recognition. The product was carry-over from another hydrocarbon type.

A4The product appears to be aged or degraded diesel.

BThe blank exhibited a positive result great than the reporting limit for this compound.

CNSee Case Narrative.

DResult is based from a dilution.

EResult exceeds the calibration range for this compound. The result should be considered as estimate.

FThe positive result for this hydrocarbon is due to single component contamination. The product does not match any hydrocarbon in the fuels library.

GResult may be biased high due to biogenic interferences. Clean up is recommended.

HSample was analyzed outside recommended holding time.

HTAt clients request, samples was analyzed outside of recommended holding time.

JThe result for this analyte is between the MDL and the PQL and should be considered as estimated concentration.

KDiesel result is biased high due to amount of Oil contained in the sample.

LDiesel result is biased high due to amount of Gasoline contained in the sample.

MOil result is biased high due to amount of Diesel contained in the sample.

MCSample concentration is greater than 4x the spiked value, the spiked value is considered insignificant.

MIResult is outside control limits due to matrix interference.

MSAValue determined by Method of Standard Addition.

OLaboratory Control Standard (LCS) exceeded laboratory control limits, but meets CCV criteria. Data meets EPA requirements.

QDetection levels elevated due to sample matrix.

RRPD control limits were exceeded.

RFDuplicate failed due to result being at or near the method-reporting limit.

RPMatrix spike values exceed established QC limits; post digestion spike is in control.

SRecovery is outside control limits.

SCClosing CCV or LCS exceeded high recovery control limits, but associated samples are non-detect. Data meets EPA requirements.

* The result for this parameter was greater that the maximum contaminant level of the TCLP regulatory limit.

Silverton Road: Little Pudding River Bridge Replacement Geotechnical Engineering Report

Important Information Important Information About Your Geotechnical/Environmental Report

N IMPORTANT INFORMATIO

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CONSULTING SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND FOR SPECIFIC CLIENTS. Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be adequate for a construction contractor or even another civil engineer. Unless indicated otherwise, your consultant prepared your report expressly for you and expressly for the purposes you indicated. No one other than you should apply this report for its intended purpose without first conferring with the consultant. No party should apply this report for any purpose other than that originally contemplated without first conferring with the consultant.

THE CONSULTANT’S REPORT IS BASED ON PROJECT-SPECIFIC FACTORS. A geotechnical/environmental report is based on a subsurface exploration plan designed to consider a unique set of project-specific factors. Depending on the project, these may include the general nature of the structure and property involved; its size and configuration; its historical use and

practice; the location of the structure on the site and its orientation; other improvements such as N access roads, parking lots, and underground utilities; and the additional risk created by scope-of-service limitations imposed by the client. To help avoid costly problems, ask the consultant to evaluate how any factors that change subsequent to the date of the report may affect the recommendations. Unless your consultant indicates otherwise, your report should not be used (1) when the nature of the proposed project is changed (for example, if an office building will be erected instead of a parking garage, or if a refrigerated warehouse will be built instead of an unrefrigerated one, or chemicals are discovered on or near the site); (2) when the size, elevation, or configuration of the proposed project is altered; (3) when the location or orientation of the proposed project is modified; (4) when there is a change of ownership; or (5) for application to an adjacent site. Consultants cannot accept responsibility for problems that may occur if they are not consulted after factors that were considered in the development of the report have changed.

SUBSURFACE CONDITIONS CAN CHANGE.

IMPORTANT INFORMATIO Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report is based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for example, groundwater conditions commonly vary seasonally. Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or groundwater fluctuations may also affect subsurface conditions and, thus, the continuing adequacy of a geotechnical/environmental report. The consultant should be kept apprised of any such events and should be consulted to determine if additional tests are necessary.

MOST RECOMMENDATIONS ARE PROFESSIONAL JUDGMENTS. Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data were extrapolated by your consultant, who then applied judgment to render an opinion about overall subsurface conditions. The actual interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas

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not sampled may differ from those predicted in your report. While nothing can be done to prevent such situations, you and your consultant can work together to help reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly beneficial in this respect.

A REPORT’S CONCLUSIONS ARE PRELIMINARY. The conclusions contained in your consultant’s report are preliminary, because they must be based on the assumption that conditions revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can be discerned only during earthwork; therefore, you should retain your consultant to observe actual conditions and to provide conclusions. Only the consultant who prepared the report is fully familiar with the background information needed to determine whether or not the report’s recommendations based on those conclusions are valid and whether or not the contractor is abiding by applicable recommendations. The consultant who developed your report cannot assume responsibility or liability for the adequacy of the report’s recommendations if another party is retained to observe construction.

THE CONSULTANT’S REPORT IS SUBJECT TO MISINTERPRETATION.

N Costly problems can occur when other design professionals develop their plans based on misinterpretation of a geotechnical/environmental report. To help avoid these problems, the consultant should be retained to work with other project design professionals to explain relevant geotechnical, geological, hydrogeological, and environmental findings, and to review the adequacy of their plans and specifications relative to these issues.

BORING LOGS AND/OR MONITORING WELL DATA SHOULD NOT BE SEPARATED FROM THE REPORT. Final boring logs developed by the consultant are based upon interpretation of field logs (assembled by site personnel), field test results, and laboratory and/or office evaluation of field samples and data. Only final boring logs and data are customarily included in geotechnical/environmental reports. These final logs should not, under any circumstances, be redrawn for inclusion in architectural or other design drawings, because drafters may commit errors or omissions in the transfer process. IMPORTANT INFORMATIO To reduce the likelihood of boring log or monitoring well misinterpretation, contractors should be given ready access to the complete geotechnical engineering/environmental report prepared or authorized for their use. If access is provided only to the report prepared for you, you should advise contractors of the report’s limitations, assuming that a contractor was not one of the specific persons for whom the report was prepared, and that developing construction cost estimates was not one of the specific purposes for which it was prepared. While a contractor may gain important knowledge from a report prepared for another party, the contractor should discuss the report with your consultant and perform the additional or alternative work believed necessary to obtain the data specifically appropriate for construction cost estimating purposes. Some clients hold the mistaken impression that simply disclaiming responsibility for the accuracy of subsurface information always insulates them from attendant liability. Providing the best available information to contractors helps prevent costly construction problems and the adversarial attitudes that aggravate them to a disproportionate scale.

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READ RESPONSIBILITY CLAUSES CLOSELY. Because geotechnical/environmental engineering is based extensively on judgment and opinion, it is far less exact than other design disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem, consultants have developed a number of clauses for use in their contracts, reports, and other documents. These responsibility clauses are not exculpatory clauses designed to transfer the consultant’s liabilities to other parties; rather, they are definitive clauses that identify where the consultant’s responsibilities begin and end. Their use helps all parties involved recognize their individual responsibilities and take appropriate action. Some of these definitive clauses are likely to appear in your report, and you are encouraged to read them closely. Your consultant will be pleased to give full and frank answers to your questions. The preceding paragraphs are based on information provided by the ASFE/Association of Engineering Firms Practicing in the Geosciences, Silver Spring, Maryland

N IMPORTANT INFORMATIO

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