Independence-3-01 GTES Report 013024.pdf

10240 SW Nimbus Avenue

Suite L6 Portland, Oregon 97223

503.616.9419 www.centralgeotech.com

January 30, 2024

Keller Associates, Inc.

245 Commercial Street SE, #210 Salem, OR 97301

Attention: Shannon Williams, PE

Re: Report of Geotechnical Engineering Services:

CGS Project: Independence-3-01 Corvallis Road Water Line Improvements Corvallis Road Independence, Oregon

Central Geotechnical Services, LLC (CGS) is pleased to submit this report of geotechnical engineering services for the proposed City of Independence Corvallis Road Water Line Improvement Project in

Independence, Oregon. This report was prepared in conformance with the signed contract dated

November 28, 2023. We appreciate the opportunity to be of service to Keller Associates, Inc. Please feel free to call our office with questions about this report.

Respectfully, Central Geotechnical Services, LLC

Julio Vela, PhD, P.E., G.E.

Principal Engineer

Report of Geotechnical Engineering Services:

City of Independence – Corvallis Road Water Line Improvements

CGS Project: Independence-3-01

Prepared For:

Keller Associates 245 Commercial Street SE, #210 Salem, Oregon 97301

January 30, 2024

Submitted by:

Central Geotechnical Services, LLC January 30, 2024 |Page i

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements

Independence-3-01

Table of Contents

1.0 INTRODUCTION

2.0 PURPOSE AND SCOPE OF WORK

3.0 SITE CONDITIONS

3.1. Site Geology

3.2. Surface Conditions

3.3. Subsurface Conditions

3.3.1. Soil Conditions

3.3.2. Groundwater Conditions

3.3.3. AC Pavement Section

4.0 CONCLUSIONS

5.0 EARTHWORK RECOMMENDATIONS

5.1. Site Preparation

5.2. Pipe Foundation Support

5.3. Subgrade Protection and Wet Weather Considerations

5.4. Dewatering

5.5. Shored Excavations

5.6. Trench Shoring

5.7. Pipe Bedding and Trench Backfill

5.7.1. Reuse of On-Site Soils

5.7.2. Fill Placement and Compaction

6.0 SIGNATURES

7.0 REFERENCES

LIST OF FIGURES

Figure 1. Vicinity Map Figure 2. Site Plan

APPENDICES

Appendix A. Field Explorations and Laboratory Testing Figure A-1. Key to Exploration Logs Figure A-2 through A-11. Logs of Explorations Figure A-12 Atterberg Limits Determination

Central Geotechnical Services, LLC January 30, 2024 |Page ii

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements

(This page intentionally left blank)

Central Geotechnical Services, LLC January 30, 2024 |Page 3

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements

1.0 INTRODUCTION

Central Geotechnical Services, LLC (CGS) is pleased to submit this geotechnical engineering report to Keller

Associates, Inc. (Keller) for the proposed City of Independence’s (City) Corvallis Road Water Line project along

Corvallis Road between River Road South and Independence Way in Independence, Oregon. The approximate location of the site is shown in the Vicinity Map, Figure 1.

Our understanding of the project is based on our discussions with, and information provided to us by Keller.

We understand that the project will include improvements to the existing 10-inch PVC water main beneath

Corvallis Road between River Road South and Independence Way, and construction of a new 12-inch transmission water line extending from Independence Way approximately 1,300 feet east along Corvallis

Road. We completed ten borings (B-1 to B-10) to depths of approximately 11.5-feet below ground (roadway) surface (bgs) along the alignment of proposed improvements. Logs of our explorations are included in

Appendix A.

2.0 PURPOSE AND SCOPE OF WORK

The purpose of our services was to evaluate soil and groundwater conditions as a basis for developing geotechnical engineering design criteria and geotechnical construction recommendations for the proposed project. Our scope of services was provided in general accordance with our proposal titled “Proposal for

Geotechnical Engineering Design Services,” to Keller Associates, Inc. dated August 3, 2023, and authorized

November 28, 2023. We completed the following scope of services:

1. Reviewed information regarding subsurface soil and groundwater in the vicinity of the site, including reports in our files, selected geologic maps, and other geotechnical engineering-related information.

2. Coordinated and managed the field investigation, including public utility notification and scheduling of subcontractors and CGS field staff. Requested public and private utility locates.

3. Explored subsurface soil and groundwater conditions at the site by drilling 10 exploratory borings with a truck -mounted drill rig. All borings were advanced to a final depth of approximately 11.5-ft bgs.

4. Obtained samples at representative intervals from the explorations, observed groundwater conditions and maintained detailed logs in general accordance with ASTM International (ASTM) Standard Practices

Test Method D 2488. Qualified staff from our office observed and documented field activities.

5. Performed laboratory tests on selected soil samples obtained from the explorations to evaluate pertinent engineering characteristics. Laboratory test results are summarized in the logs in Appendix A.

6. Provided a geotechnical evaluation of the site and provided design recommendations in this geotechnical report with the following geotechnical components:

a. A general description of site topography, geology, and subsurface conditions.

b. An opinion as to the adequacy of the proposed development from a geotechnical engineering standpoint.

Central Geotechnical Services, LLC January 30, 2024 |Page 4

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements

c. Recommendations for site preparation measures, including disposition of undocumented fill and unsuitable native soils, recommendations for temporary cut slopes and constraints for wet weather construction.

d. Provided estimates of groundwater level and management recommendations.

e. Recommendations for temporary excavation and temporary excavation protection, such as excavation sheeting and bracing.

f. Recommendations for earthwork construction, including use of on-site and imported structural fill, and fill placement and compaction requirements.

3.0 SITE CONDITIONS

3.1. Site Geology

Near surface geology of the site is mapped by O’Connor et el. (2001) as main body of fine-grained facies of the Pleistocene catastrophic (Missoula) flood deposits below altitudes of 395 ft mean sea level (MSL.) This unit generally consists of stratified silt and clay with sand with rhythmic bedding up to 3 to 4 feet thick.

Additionally, it encloses sparse pebbles to boulders. This description is generally consistent with site soils observed in our subsurface explorations that suggest the site is underlain by clayey, and silty flood deposits with trace gravel.

3.2. Surface Conditions

The overall project site includes approximately 2,900 lineal feet along Corvallis Road in the southbound direction from its intersection with River Road S. Existing developments within the project limits include the asphalt concrete pavement section and subsurface utilities. Site grades are generally flat or sloping gently to the east.

3.3. Subsurface Conditions

We explored subsurface conditions at the site by drilling a total of ten geotechnical borings (B-1 through B-

10) on September 28, 2023. All borings were completed to a final depth of approximately 11.5 feet bgs in proximity to the proposed alignment for utility improvements. Approximate locations of the explorations completed at the site are presented in Figure 2. Exploration logs are presented in Appendix A together with a description of the exploration method.

Soil samples obtained during our explorations were taken to our laboratory for further evaluation. Selected samples were tested for determination of moisture content. A description of the laboratory testing and test results are presented in Appendix A.

3.3.1. Soil Conditions

In general, subsurface conditions beneath the pavement section consist of up to 5 feet of medium stiff to hard gravelly silt and clay or loose to medium dense silty clayey gravel fill that was observed in all explortions

Central Geotechnical Services, LLC January 30, 2024 |Page 5

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements except B-3 and B-4, underlain by native medium stiff to very stiff silt and clay with trace gravel that was observed to extend to the maximum depths observed in our explorations of 11.5 feet bgs.

3.3.2. Groundwater Conditions

Static groundwater was not observed at the time of our explorations. Based on observations on site and data from nearby sites, groundwater may be present at shallow depths in a perched condition on harder underlying layers as it infiltrates downward or moves downslope towards the nearby Willamette River during wet times of the year or during extended periods of wet weather. Groundwater conditions at the site are expected to vary seasonally due to rainfall events and other factors not observed in our explorations.

3.3.3. AC Pavement Section

Pavement sections within the existing roadway were generally observed to consist of AC over aggregate base with AC thickness generally between 9 to 14 inches, except for B-9 where we observed approximately 18-inches of AC. A summary of existing pavement conditions observed in field pavement cores is presented in

Table 1.

Table 1. Existing Pavement Thickness

Boring

Thickness (inches)

AC Aggregate Base

B-1 9.0 4.0

B-2 9.0 14.0

B-3 14.0 4.0

B-4 13.5 1.0

B-5 11.5 0.0

B-6 13.0 1.0

B-7 13.5 0.0

B-8 13.5 1.0

B-9 13.0 1.5

B-10 18.0 4.0

4.0 CONCLUSIONS

Based on our explorations, testing, and analyses, it is our opinion that the site is suitable for the proposed water line alignment project from a geotechnical standpoint, provided the recommendations in this report

Central Geotechnical Services, LLC January 30, 2024 |Page 6

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements are incorporated into the project design and implemented during construction. We offer the following conclusions regarding geotechnical engineering design and construction at the site.

• Groundwater was not observed during our explorations. However, based on our experience and our observations, shallow groundwater may be present during periods of persistent rainfall, particularly in a perched condition atop hydraulically restricting layers.

• Per the Dity of Independence Design Standards (COIDS), native fine-grained site soils are not suitable for reuse as fill within utility trenches. Soils generated from excavation for improvements within the existing water line trench may be reusable as utility trench zone backfill provided that it meets the requirements of Division 5 and appendices A and B of the COIDS.

• Although native fine grained site soils are not suitable for reuse as fill within utility trenches per the

COIDS, they may be reusable as general structural fill for the nearby water treatment plant project or other fill projects.

• Pavement sections should be restored to the sections in place along the alignment (in-kind replacement of the section).

5.0 EARTHWORK RECOMMENDATIONS

5.1. Site Preparation

In general, initial site preparation and primary earthwork operations will include demolition and reconstruction of the existing pavement section and excavating and filling for existing utility improvements and installation of new utilities. Demolition and reconstruction of pavement sections for utility trenches should be completed in accordance with the COIDS and applicable Standard Details.

5.2. Pipe Foundation Support

Based on conditions observed in our explorations, soils at the bottom of the proposed new 12-inch transmission line are anticipated to consist primarily of moisture sensitive fine-grained soils that could easily become disturbed by construction activities. In a disturbed condition they will provide poor foundation support for the proposed utilities. If the trench bottom becomes disturbed due to excavation and construction foot traffic, disturbed soils should be overexcavated to undisturbed native soils and replaced using properly compacted granular fill as discussed in the Pipe Bedding and Trench Backfill section of this report.

Upon completion of site preparation activities, exposed subgrades should be probed to identify soft, loose, or unsuitable areas. Probing should be conducted prior to placing fill and should be performed by a representative of CGS who will evaluate the suitability of the subgrade and identify areas of yielding that are indicative of soft or loose soil. If soft or loose zones are identified during probing, these areas should be excavated to the extent indicated by our representative and replaced with properly compacted ¾”-0” granular backfill as discussed in the Structural Fill section of this report.

As discussed in the Subsurface Conditions, native soils observed in our explorations are generally fine grained and are considered to be highly sensitive to moisture that will be difficult, or not possible, to compact adequately during wet weather. While tilling and compacting is the economical method for subgrade

Central Geotechnical Services, LLC January 30, 2024 |Page 7

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements improvement, it will likely only be possible during extended dry periods and following moisture-conditioning of the soil.

5.3. Subgrade Protection and Wet Weather Considerations

If wet weather construction practices are necessary based on conditions observed at the time of construction, it may be necessary to use gravel working pads and employ other methods to reduce ground disturbance within but not limited to utility trench subgrades and subgrade soils beneath the existing pavement section. The contractor should be responsible for protecting the subgrade during construction.

Earthwork planning should include considerations for minimizing subgrade disturbance. We provide the following recommendations if wet weather construction is considered:

• Earthwork activities should not take place during periods of heavy precipitation.

• Site soils should not be left in a disturbed or uncompacted state and exposed to moisture. Sealing the surficial soils by rolling with a smooth-drum roller prior to periods of precipitation may reduce the extent to which these soils become wet or unstable.

• Construction activities should be scheduled so that the length of time that soil is left exposed to moisture is reduced to the extent practicable.

• Construction traffic should be restricted to specific areas of the site, preferably areas that are not susceptible to wet weather disturbance such as areas that are adequately surfaced with working pad materials.

• When on-site, moisture sensitive soils are wet of optimum, they are easily disturbed and will not provide adequate support for construction traffic. Granular fill in addition to the minimum 6-inches of pipe zone embedment as discussed in the Structural Fill and Backfill section of this report, or other subgrade stabilization methods may be required within trench excavations to create a firm unyielding working platform to allow for proper compaction of utility trench backfill.

• During periods of wet weather, foundation bearing surfaces, including trench foundations, should not be exposed to standing water. Should water infiltrate and pool in the excavation, the water should be removed, and the foundation subgrade should be re-evaluated before placing utilities.

subgrade should be evaluated prior to the placement of trench backfill by observing excavation activity and probing with a steel foundation probe. Observations and probing should be performed by a member of our staff. Wet soil that has been disturbed due to site preparation activities, or soft or loose zones identified during probing, should be removed, and replaced with properly compact Granular Backfill.

5.4. Dewatering

As discussed in the “Groundwater” section of this report, groundwater was not encountered in our explorations. We do not expect groundwater to be a major factor during shallow excavations and earthwork.

Excavations that extend into saturated/wet soils, or excavations that extend into perched groundwater, should be dewatered. Sump pumps are expected to adequately address groundwater encountered in shallow excavations. In addition to groundwater seepage, surface water inflow to the excavations during the wet

Central Geotechnical Services, LLC January 30, 2024 |Page 8

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements season can be problematic. Provisions for surface water control during earthwork and excavations should be included in the project plans and should be installed prior to commencing earthwork.

5.5. Shored Excavations

We anticipate that excavation shoring will be required for the planned depth of excavation during utility construction. Because of the diversity of available shoring systems and construction techniques, the design of temporary shoring is most appropriately left up to the contractor proposing to complete the installation. We recommend that the shoring be designed by a Professional Engineer (PE) licensed in Oregon, and that the

PE-stamped shoring plans and calculations be submitted to the project team for review prior to construction.

The following paragraphs present recommendations for the type of shoring system and design parameters appropriate for the subsurface conditions at the project.

The soils within the project area consist of medium stiff to very stiff silt and clay with trace gravel. These soils can be retained using conventional shoring systems such as a box system with internal slide bracing.

Temporary shoring should be designed for lateral pressures resulting from: the retained soil; surcharge loads resulting from traffic; surcharge loads resulting from construction equipment and temporary stockpiles adjacent to the excavation; and other lateral and surcharge loads that will be imposed on the shoring. Lateral load resistance can be mobilized through the use of braces, tiebacks, anchor blocks and passive pressures on structural shoring members that extend below the base of the excavation.

Temporary shoring can be designed using equivalent fluid density soil pressures. We recommend that temporary shoring, for conditions with horizontal ground or horizontal backfill conditions adjacent to the excavation, be designed using a lateral soil pressure equal to an equivalent fluid density (efp) of 40 pounds per cubic foot (pcf), assuming a level surface behind retaining structures for a lateral distance equal to the excavation height as measured perpendicular from the face of shoring elements. Other conditions should be evaluated on a case-by-case basis such as shoring with multiple levels of support where lateral earth pressures can be modified to apparent earth pressures with a distribution different from efp.

The lateral soil pressure value presented in the preceding paragraph does not include surcharge-induced pressures, such as from traffic or construction surcharges, which should be included where appropriate.

Shoring that will support passenger vehicle traffic should be designed for a traffic influence equal to a uniform lateral pressure of 100 pounds per square foot (psf) acting over the full depth of the excavation.

Construction traffic will require higher lateral pressures that should be evaluated based on the planned construction vehicle surcharge loading. Additional pressure values should be applied as the designer deems them appropriate.

The later soil pressure values and recommendations provided in this report are predicated on essentially dewatered condition; therefore, hydrostatic water pressures are not included.

5.6. Trench Shoring

While we anticipate trench shoring will be the most economical option for construction of deep utilities, excavations may be laid back per the following recommendations in lieu of shoring, if feasible.

All trench excavations should be made in accordance with applicable Occupational Safety and Health

Administration (OSHA) and state regulations. In our opinion, native soils are generally OSHA Type B, provided there is no seepage and excavations occur during periods of dry weather. Temporary excavations deeper

Central Geotechnical Services, LLC January 30, 2024 |Page 9

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements than 4 feet should be shored or laid back at an inclination of 1H:1V or flatter if workers are required to enter.

Excavations made to construct footings or other structural elements should be laid back or shored at the surface as necessary to prevent soil from falling into excavations.

It should be expected that unsupported cut slopes will experience some sloughing and raveling if exposed to water. Plastic sheeting, placed over the exposed slope and directing water away from the slope, will reduce the potential for sloughing and erosion of cut slopes during wet weather.

The contractor is responsible for shoring methods and shoring system design. Shoring systems should be designed by a professional engineer before installation.

In our opinion, the contractor will be in the best position to observe subsurface conditions continuously throughout the construction process and to respond to the soil and groundwater conditions. Construction site safety is generally the sole responsibility of the contractor, who also is solely responsible for the means, methods, and sequencing of the construction operations and choices regarding excavations and shoring.

Under no circumstances should the information provided by CGS be interpreted to mean that CGS is assuming responsibility for construction site safety or the contractor’s activities; such responsibility is not being implied and should not be inferred.

5.7. Pipe Bedding and Trench Backfill

To provide uniform support of buried utility pipes, the pipe should be embedded in accordance with the applicable standard drawings of Appendix A of the COIDS. Pipe bedding and trench zone backfill should consist of ¾”- 0” conforming to OSSC (ODOT/APWA) 02630.10 (Dense Graded Base Aggregate), with no more than 10- and 5-percent passing the #40 sieve and #200 sieve, respectively, unless otherwise approved by the

City of Independence and CGS. As noted previously, granular material in addition to the minimum pipe zone bedding may be necessary for subgrade stabilization based on the conditions observed during construction. If additional granular material is required for subgrade stabilization, it should be encased in a non-woven geotextile fabric.

5.7.1. Reuse of On-Site Soils

Soils generated from onsite excavations for improvements to the existing water line are expected to consist of trench backfill. Soils from within the footprint of the proposed new 12-inch water transmission line are anticipated to consist of native medium stiff to very stiff silt and clay. On-site excavated soils may be reused as Trench Backfill, Bedding, and Pipe Zone materials if it meets the requirements of the City’s Design standards. An experienced geotechnical engineer from CGS should determine the suitability of on-site soil encountered during earthwork activities for reuse as fill within utility trenches.

We do not anticipate that soils excavated for the new transmission line will be suitable for reuse as fill within the utility trench. However, it could potentially be reused as structural fill for the nearby planned water treatment plant project, if necessary.

Central Geotechnical Services, LLC January 30, 2024 |Page 10

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements

5.7.2. Fill Placement and Compaction

Utility construction should be completed in accordance with Division 5 and Standard Detail number 301 of the COIDS. Additionally, compaction of pipe foundation and pipe zone fill should be completed in accordance with the manufacturer’s recommendations.

Central Geotechnical Services, LLC January 30, 2024 |Page 11

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements

6.0 SIGNATURES

We appreciate the opportunity to provide geotechnical services to support your project. If you feel obliged, we welcome referrals from our previous clients and would enjoy the opportunity to work with others in your professional and personal networks.

Central Geotechnical Services, LLC

Julio Vela, PhD, PE, GE Blayne Sandau, PE, GIT

Principal Engineer Project Engineer

01/30/24

06/30/24

Central Geotechnical Services, LLC January 30, 2024 |Page 12

Geotechnical Engineering Design Services – City of Independence Corvallis Road Water Line Improvements

7.0 REFERENCES

City of Independence. 2018. “Design Standards”. https://www.ci.independence.or.us/design-standards/.

Accessed January 17, 2024.

Occupational Safety and Health Administration (OSHA). Technical Manual Section V: Chapter 2, Excavations:

Hazard Recognition in Trenching and Shoring:

http://www.osha.gov/dts/osta/otm/otm_v/otm_v_2.html.

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

United States Geological Survey Professional Paper 162.

http://www.osha.gov/dts/osta/otm/otm_v/otm_v_2.html

APPENDIX A: Field Explorations

APPENDIX A

FIELD EXPLORATIONS AND LABORATORY TESTING

Field Explorations

Soil and groundwater conditions at the proposed project were explored on December 28, 2023, by completing ten drilled borings (B-1 through B-10), at the approximate locations shown on the Site Plan, Figure 2. The exploratory borings were extended to final depths of approximately 11.5-feet below ground surface using a 3-1/4-inch diameter solid stem auger.

The drilling was continuously monitored by a qualified staff from our office who maintained detailed logs of subsurface explorations, visually classified the soil encountered and obtained representative soil samples from the borings. Representative soil samples were obtained from each boring at approximate 2½-and 5 foot-depth intervals using a 1-inch, inside-diameter, standard split spoon sampler. The samplers were driven into the soil using a 140-pound hammer, free-falling 30 inches on each blow. The number of blows required to drive the sampler each of three, 6-inch increments of penetration were recorded in the field. The sum of the blow counts for the last two, 6-inch increments of penetration is reported on the boring logs as the ASTM

International (ASTM) Test Method D 1556 Standard Penetration Test (SPT) N-value.

Recovered soil samples from exploratory borings and test pits were visually classified in the field in general accordance with ASTM D 2488 and the classification chart listed in Key to Exploration Logs. Logs of the borings are presented in this Appendix. The logs are based on interpretation of the field and laboratory data and indicate the depth at which subsurface materials, or their characteristics change, although these changes might actually be gradual.

Laboratory Testing

Soil samples obtained from the explorations were visually classified in the field and in our laboratory using the USCS and ASTM classification methods. ASTM Test Method D 2488 was used to visually classify the soil samples, while ASTM D 2487 was used to classify the soils based on laboratory tests results. Moisture content tests were performed in general accordance with ASTM D 2216-05. Results of the moisture contents testing are presented in the appropriate exploration logs at the respective sample depths.

Atterberg limits testing was performed on selected fine-grained samples. The tests were used to classify the soil as well as to evaluate index properties. The liquid limit and the plastic limit were estimated through a procedure performed in general accordance with ASTM D 4318. The results of the Atterberg limits testing are summarized in Figure A-12

ATT

LETTER GRAPH CBR

GW CON

GP DD

GM DS

GC HYD

SW LL

SP PL

SM PI

SC MC

ML MD

CL NP

OL OC

MH P

CH PP

OH

Passing

No.200

TS RES

SIEV

TOR

AC UC

CC VS

CR

SOD

FILL

NO

MINOR

MODERATE

SEVERE

SYMBOL

Approximate contact between soil strata

SOD/FOREST DUFF

FILL

ADDITIONAL MATERIALS

POORLY-GRADED SAND AND GRAVELLY

SANDS, LITTLE OR NO FINES

SANDS WITH FINES

SILTY SANDS, SAND/SILT MIXTURES

CONTACT TYPES

Distinct contact between soil strata (approximate location)

LIQUID LIMIT MORE

THAN 50

INORGANIC SILTS, SILTS WITH CLAY

INORGANIC CLAYS OF HIGH PLASTICITY, FAT

CLAYS

ORGANIC CLAYS OF MEDIUM TO HIGH

PLASTICITY

LIQUID LIMIT LESS

THAN 50

GEOTECHNICAL TESTING EXPLANATIONS

WATER LEVELS

Water Level at Time of Drilling, or as labeled

Water Level at End of Drilling, or as labeled

Moisture-Density

Static Water Level, or as labeled

Non-Plastic

Organic Content

Pushed Sample

Pocket Penetrometer

Percent Passing U.S. Std. No.200 Sieve

Resilient Modulus

Sieve Gradation

Torvane

Vane Shear

Unconfined Compressive Strength

Hydrometer Gradation

Liquid Limit

Plastic Limit

Plasticity Index

Moisture Content

Atterberg Limits

California Bearing Ratio

Consolidation

Dry Density

Direct Shear

Location of sample collected using Dames & Moore sampler or pushed with recovery

SAMPLER DESCRIPTIONS

Location of sample collected using the thin-wall Shelby tube or

Geoprobe sample in general accordance with ASTM D1587 with recovery (SH)

Location of sample collected in general accordance with ASTM D2573 using the field Vane Shear test in saturated fine-grained soils with recovery

Location of sample collected in general accordance with ASTM D1586 using Standard Penetration Test (SPT) with recovery (SS)

GAP GRADED

SYMBOL

UNIFORMLY GRADED

SAND

COMMON SPALLING

Location of auger cuttings sample

Location of bulk or grab sample (GS)

LIMITED RANGE OF GRAIN SIZES

SAMPLER DESCRIPTIONS

WILL NOT STAND VERTICAL

PREDOMINANTLY ONE GRAIN SIZE

GAPS WITHIN RANGE OF GRAIN SIZES

ASPHALT CONCRETE

CEMENT CONCRETE

CRUSHED ROCK

POORLY GRADED

SOIL CHARACTERISTICS

INORGANIC CLAY, CLAY WITH LOW TO

MEDIUM PLASTICITY

ORGANIC SILTS, ORGANIC SILTY CLAYS WITH

LOW PLASTICITY

ISOLATED SPALLING

CLAYEY SANDS, SAND/CLAY MIXTURES

INORGANIC SILTS, SILT WITH SLIGHT

PLASTICITY

SOIL CLASSIFICATION

TYPICAL DESCRIPTIONS

SILTY GRAVELS, GRAVEL/SAND/SILT MIXTURES

CLAYEY GRAVELS, GRAVEL/SAND/CLAY

MIXTURES

GRAVEL

CLEAN GRAVELS

WELL-GRADED GRAVELS AND GRAVEL/SAND

MIXTURES, LITTLE OR NO FINES

POORLY-GRADED GRAVELS, GRAVEL/SAND

MIXTURES, LITTLE OR NO FINES

GRAVELS WITH FINES

SYMBOLS

MAJOR DIVISIONS

COARSE

GRAINED

(MORE THAN

50% RETAINED

BY NO. 200

SIEVE)

WALL STANDING VERTICAL

CLEAN SANDS

WELL-GRADED SAND AND GRAVELLY SANDS,

LITTLE OR NO FINES

FINE

GRAINED

(MORE THAN

50% PASSING

BY NO. 200

SIEVE)

HIGHLY ORGANIC SOILS

GRADATION

WELL-GRADED

SILTS AND

CLAYS

Location of rock coring interval (RC)

No Recovery

TOPSOIL, PEAT, HUMUS, MULCH AND OTHER

HIGH ORGANIC SOILS

CAVING

FULL RANGE OF GRAIN SIZES

Figure: A-1

GS

S-1

SS

S-2

SS

S-3

SS

S-4

0.8

1.1

11.5

ASPHALT CONCRETE (9.0-inches)

AGGREGATE BASE (4.0-inches)

Medium stiff sandy SILT (ML), trace organics, brown w/ gray, moist becomes without sand @ 2.5-ft becomes stiff @ 5-ft bgs bceomes very stiff @ 10-ft bgs

Boring terminated at 11.5 feet bgs

4-1-4

4-4-6

6-8-9

G R

A

PH

IC

L

O G

Remarks:

SA

M

PL

E

TY

PE

N U

M B

ER

Operator: Dan J Fischer Excavating

Drilling Method: 4.5" Core / 4 3/8" Auger

Groundwater at end of drilling: ---

Checked By: Blayne Sandau Logged By: Adrian Cadena

Approximate Ground Elevation:

Approximate Location Coordinates:

Lat: Long:

LA

B

R

ES

U

LT

S/ R

EM

A

R K

S

Date Completed:

12/28/23

Date Started:

12/28/23 Groundwater first observed: --- Groundwater Not Observed

Equipment: Trailer Mounted Drill Rig

D

EP

TH

ft

BORING LOG B-1

MATERIAL DESCRIPTION

Client: Keller Associates

Project: Corvallis Road Water Line Improvements

Location: Corvallis Road, Independence, OR

Project No:

Independence-3-01

B

O R

IN

G

T

EM

PL

A

TE

_2

C

G S

B O

R

IN

G L

O G

.G D

T

/1

/2

:4

C

U

SE

R S\

C G

SU

SE

R \C

EN

TR

A L

G

EO

TE

C

H N

IC

A

L

SE

R V

IC

ES

\C G

S

P R

O

JE

C

TS

\I -Q

\I N

D

EP

EN

D

EN

C

E\

IN

D

EP

EN

D

EN

C

E-

\I N

D

EP

EN

D

EN

C

E-

-0

\F

IE

LD

E

X

PL

O R

A

TI

O N

\2 _F

IE

LD

A N

D D

R A

FT

L

O G

S\

IN

D

EP

EN

D

EN

C

E-

-0

L O

G S.

G P

J Central Geotechnical Services 10240 SW Nimbus Ave, Suite L6 Portland, OR 97223 Telephone: (503) 616-9419

M O

IS

TU

R E

R

EC

O V

ER

Y in

B

LO

W C

O U

N

TS

SS

S-2

SS

S-3

SS

S-4

0.8

1.9

11.5

ASPHALT CONCRETE (9.0-inches)

AGGREGATE BASE (14.0-inches)

Soft, gravelly SILT (ML), trace medium to coarse sand, gravels are rounded, moist becomes medium stiff, without gravel, and gray @ 4-ft bgs becomes stiff at 10-ft bgs

Boring terminated at 11.5 feet bgs

4-2-1

4-2-4

6-5-5

G R

A

PH

IC

L

O G

Remarks:

SA

M

PL

E

TY

PE

N U

M B

ER

Operator: Dan J Fischer Excavating

Drilling Method: 4.5" Core / 4 3/8" Auger

Groundwater at end of drilling: ---

Checked By: Blayne Sandau Logged By: Adrian Cadena

Approximate Ground Elevation:

Approximate Location Coordinates:

Lat: Long:

LA

B

R

ES

U

LT

S/ R

EM

A

R K

S

Date Completed:

12/28/23

Date Started:

12/28/23 Groundwater first observed: --- Groundwater Not Observed

Equipment: Trailer Mounted Drill Rig

D

EP

TH

ft

BORING LOG B-2

MATERIAL DESCRIPTION

Client: Keller Associates

Project: Corvallis Road Water Line Improvements

Location: Corvallis Road, Independence, OR

Project No:

Independence-3-01

B

O R

IN

G

T

EM

PL

A

TE

_2

C

G S

B O

R

IN

G L

O G

.G D

T

/1

/2

:4

C

U

SE

R S\

C G

SU

SE

R \C

EN

TR

A L

G

EO

TE

C

H N

IC

A

L

SE

R V

IC

ES

\C G

S

P R

O

JE

C

TS

\I -Q

\I N

D

EP

EN

D

EN

C

E\

IN

D

EP

EN

D

EN

C

E-

\I N

D

EP

EN

D

EN

C

E-

-0

\F

IE

LD

E

X

PL

O R

A

TI

O N

\2 _F

IE

LD

A N

D D

R A

FT

L

O G

S\

IN

D

EP

EN

D

EN

C

E-

-0

L O

G S.

G P

J Central Geotechnical Services 10240 SW Nimbus Ave, Suite L6 Portland, OR 97223 Telephone: (503) 616-9419

M O

IS

TU

R E

R

EC

O V

ER

Y in

B

LO

W C

O U

SS

S-2

SS

S-3

SS

S-4

LL = 51%;

PL = 28%

1.2

1.5

11.5

ASPHALT CONCRETE (14.0-inches)

AGGREGATE BASE (4.0-inches)

Stiff CLAY (CH), trace fine sand, gray, moist becomes very stiff @ 10-ft bgs

Boring terminated at 11.5 feet bgs

5-4-7

4-6-5

6-8-9

G R

A

PH

IC

L

O G

Remarks:

SA

M

PL

E

TY

PE

N U

M B

ER

Operator: Dan J Fischer Excavating

Drilling Method: 4.5" Core / 4 3/8" Auger

Groundwater at end of drilling: ---

Checked By: Blayne Sandau Logged By: Adrian Cadena

Approximate Ground Elevation:

Approximate Location Coordinates:

Lat: Long:

LA

B

R

ES

U

LT

S/ R

EM

A

R K

S

Date Completed:

12/28/23

Date Started:

12/28/23 Groundwater first observed: --- Groundwater Not Observed

Equipment: Trailer Mounted Drill Rig

D

EP

TH

ft

BORING LOG B-3

MATERIAL DESCRIPTION

Client: Keller Associates

Project: Corvallis Road Water Line Improvements

Location: Corvallis Road, Independence, OR

Project No:

Independence-3-01

B

O R

IN

G

T

EM

PL

A

TE

_2

C

G S

B O

R

IN

G L

O G

.G D

T

/1

/2

:4

C

U

SE

R S\

C G

SU

SE

R \C

EN

TR

A L

G

EO

TE

C

H N

IC

A

L

SE

R V

IC

ES

\C G

S

P R

O

JE

C

TS

\I -Q

\I N

D

EP

EN

D

EN

C

E\

IN

D

EP

EN

D

EN

C

E-

\I N

D

EP

EN

D

EN

C

E-

-0

\F

IE

LD

E

X

PL

O R

A

TI

O N

\2 _F

IE

LD

A N

D D

R A

FT

L

O G

S\

IN

D

EP

EN

D

EN

C

E-

-0

L O

G S.

G P

J Central Geotechnical Services 10240 SW Nimbus Ave, Suite L6 Portland, OR 97223 Telephone: (503) 616-9419

M O

IS

TU

R E

R

EC

O V

ER

Y in

B

LO

W C

O U

SS

S-2

SS

S-3

SS

S-4

1.1 1.2

11.5

ASPHALT CONCRETE (13.5-inches)

AGGREGATE BASE (1.0-inch)

Stiff SILT (ML), trace fine sand, brown and gray, moist becomes very stiff @ 10-ft bgs

Boring terminated at 11.5 feet bgs

3-4-5

4-5-8

6-8-10

G R

A

PH

IC

L

O G

Remarks:

SA

M

PL

E

TY

PE

N U

M B

ER

Operator: Dan J Fischer Excavating

Drilling Method: 4.5" Core / 4 3/8" Auger

Groundwater at end of drilling: ---

Checked By: Blayne Sandau Logged By: Adrian Cadena

Approximate Ground Elevation:

Approximate Location Coordinates:

Lat: Long:

LA

B

R

ES

U

LT

S/ R

EM

A

R K

S

Date Completed:

12/28/23

Date Started:

12/28/23 Groundwater first observed: --- Groundwater Not Observed

Equipment: Trailer Mounted Drill Rig

D

EP

TH

ft

BORING LOG B-4

MATERIAL DESCRIPTION

Client: Keller Associates

Project: Corvallis Road Water Line Improvements

Location: Corvallis Road, Independence, OR

Project No:

Independence-3-01

B

O R

IN

G

T

EM

PL

A

TE

_2

C

G S

B O

R

IN

G L

O G

.G D

T

/1

/2

:4

C

U

SE

R S\

C G

SU

SE

R \C

EN

TR

A L

G

EO

TE

C

H N

IC

A

L

SE

R V

IC

ES

\C G

S

P R

O

JE

C

TS

\I -Q

\I N

D

EP

EN

D

EN

C

E\

IN

D

EP

EN

D

EN

C

E-

\I N

D

EP

EN

D

EN

C

E-

-0

\F

IE

LD

E

X

PL

O R

A

TI

O N

\2 _F

IE

LD

A N

D D

R A

FT

L

O G

S\

IN

D

EP

EN

D

EN

C

E-

-0

L O

G S.

G P

J Central Geotechnical Services 10240 SW Nimbus Ave, Suite L6 Portland, OR 97223 Telephone: (503) 616-9419

M O

IS

TU

R E

R

EC

O V

ER

Y in

B

LO

W C

O U

SS

S-2

SS

S-3

SS

S-4

1.0

1.5

11.5

ASPHALT CONCRETE (11.7-inches)

Loose, sandy GRAVEL (GW-GM), trace silt, sand is medium to coarse, (FILL)

Stiff, SILT (ML), trace fine sand, gray, moist

Pockets of dark gray at 5 feet becomes very stiff @ 10-ft

Boring terminated at 11.5 feet bgs

13-3-4

5-4-6

8-10-12

G R

A

PH

IC

L

O G

Remarks:

SA

M

PL

E

TY

PE

N U

M B

ER

Operator: Dan J Fischer Excavating

Drilling Method: 4.5" Core / 4 3/8" Auger

Groundwater at end of drilling: ---

Checked By: Blayne Sandau Logged By: Adrian Cadena

Approximate Ground Elevation:

Approximate Location Coordinates:

Lat: Long:

LA

B

R

ES

U

LT

S/ R

EM

A

R K

S

Date Completed:

12/28/23

Date Started:

12/28/23 Groundwater first observed: --- Groundwater Not Observed

Equipment: Trailer Mounted Drill Rig

D

EP

TH

ft

BORING LOG B-5

MATERIAL DESCRIPTION

Client: Keller Associates

Project: Corvallis Road Water Line Improvements

Location: Corvallis Road, Independence, OR

Project No:

Independence-3-01

B

O R

IN

G

T

EM

PL

A

TE

_2

C

G S

B O

R

IN

G L

O G

.G D

T

/1

/2

:4

C

U

SE

R S\

C G

SU

SE

R \C

EN

TR

A L

G

EO

TE

C

H N

IC

A

L

SE

R V

IC

ES

\C G

S

P R

O

JE

C

TS

\I -Q

\I N

D

EP

EN

D

EN

C

E\

IN

D

EP

EN

D

EN

C

E-

\I N

D

EP

EN

D

EN

C

E-

-0

\F

IE

LD

E

X

PL

O R

A

TI

O N

\2 _F

IE

LD

A N

D D

R A

FT

L

O G

S\

IN

D

EP

EN

D

EN

C

E-

-0

L O

G S.

G P

J Central Geotechnical Services 10240 SW Nimbus Ave, Suite L6 Portland, OR 97223 Telephone: (503) 616-9419

M O

IS

TU

R E

R

EC

O V

ER

Y in

B

LO

W C

O U

SS

S-2

SS

S-3

SS

S-4

1.1 1.3 1.5

11.5

ASPHALT CONCRETE (13.0-inches)

AGGREGATE BASE (1.0-inch)

Medium stiff, gravelly SILT(ML), with fine to medium sand, brown, moist

(FILL)

Stiff SILT (ML), trace fine sand, brown and gray, moist becomes very stiff at 10-ft bgs

Boring terminated at 11.5 feet bgs

2-4-5

6-5-7

6-8-8

G R

A

PH

IC

L

O G

Remarks:

SA

M

PL

E

TY

PE

N U

M B

ER

Operator: Dan J Fischer Excavating

Drilling Method: 4.5" Core / 4 3/8" Auger

Groundwater at end of drilling: ---

Checked By: Blayne Sandau Logged By: Adrian Cadena

Approximate Ground Elevation:

Approximate Location Coordinates:

Lat: Long:

LA

B

R

ES

U

LT

S/ R

EM

A

R K

S

Date Completed:

12/28/23

Date Started:

12/28/23 Groundwater first observed: --- Groundwater Not Observed

Equipment: Trailer Mounted Drill Rig

D

EP

TH

ft

BORING LOG B-6

MATERIAL DESCRIPTION

Client: Keller Associates

Project: Corvallis Road Water Line Improvements

Location: Corvallis Road, Independence, OR

Project No:

Independence-3-01

B

O R

IN

G

T

EM

PL

A

TE

_2

C

G S

B O

R

IN

G L

O G

.G D

T

/1

/2

:4

C

U

SE

R S\

C G

SU

SE

R \C

EN

TR

A L

G

EO

TE

C

H N

IC

A

L

SE

R V

IC

ES

\C G

S

P R

O

JE

C

TS

\I -Q

\I N

D

EP

EN

D

EN

C

E\

IN

D

EP

EN

D

EN

C

E-

\I N

D

EP

EN

D

EN

C

E-

-0

\F

IE

LD

E

X

PL

O R

A

TI

O N

\2 _F

IE

LD

A N

D D

R A

FT

L

O G

S\

IN

D

EP

EN

D

EN

C

E-

-0

L O

G S.

G P

J Central Geotechnical Services 10240 SW Nimbus Ave, Suite L6 Portland, OR 97223 Telephone: (503) 616-9419

M O

IS

TU

R E

R

EC

O V

ER

Y in

B

LO

W C

O U

SS

S-2

SS

S-3

SS

S-4

1.1

1.9

11.5

ASPHALT CONCRETE (13.5-inches)

Stiff, gravelly SILT(ML), with fine to medium sand, brown, moist

(FILL)

Stiff SILT (ML), trace fine sand, brown and gray, moist become very stiff @ 10-ft bgs

Boring terminated at 11.5 feet bgs

5-4-6

5-5-7

8-10-11

G R

A

PH

IC

L

O G

Remarks:

SA

M

PL

E

TY

PE

N U

M B

ER

Operator: Dan J Fischer Excavating

Drilling Method: 4.5" Core / 4 3/8" Auger

Groundwater at end of drilling: --- Groundwater Not Observed

Checked By: Blayne Sandau Logged By: Adrian Cadena

Approximate Ground Elevation:

Approximate Location Coordinates:

Lat: Long:

LA

B

R

ES

U

LT

S/ R

EM

A

R K

S

Date Completed:

12/28/23

Date Started:

12/28/23 Groundwater first observed: ---

Equipment: Trailer Mounted Drill Rig

D

EP

TH

ft

BORING LOG B-7

MATERIAL DESCRIPTION

Client: Keller Associates

Project: Corvallis Road Water Line Improvements

Location: Corvallis Road, Independence, OR

Project No:

Independence-3-01

B

O R

IN

G

T

EM

PL

A

TE

_2

C

G S

B O

R

IN

G L

O G

.G D

T

/1

/2

:4

C

U

SE

R S\

C G

SU

SE

R \C

EN

TR

A L

G

EO

TE

C

H N

IC

A

L

SE

R V

IC

ES

\C G

S

P R

O

JE

C

TS

\I -Q

\I N

D

EP

EN

D

EN

C

E\

IN

D

EP

EN

D

EN

C

E-

\I N

D

EP

EN

D

EN

C

E-

-0

\F

IE

LD

E

X

PL

O R

A

TI

O N

\2 _F

IE

LD

A N

D D

R A

FT

L

O G

S\

IN

D

EP

EN

D

EN

C

E-

-0

L O

G S.

G P

J Central Geotechnical Services 10240 SW Nimbus Ave, Suite L6 Portland, OR 97223 Telephone: (503) 616-9419

M O

IS

TU

R E

R

EC

O V

ER

Y in

B

LO

W C

O U

SS

S-2

SS

S-3

SS

S-4

1.2 1.3

5.0

11.5

ASPHALT CONCRETE (13.5-inches)

AGGREGATE BASE (1.0-inch) very stiff to hard, gravelly SILT(ML), with fine to medium sand, brown, moist

(FILL)

Stiff SILT (ML), with fine sand, gray, moist becomes very stiff @ 10-ft bgs

Boring terminated at 11.5 feet bgs

16-30-31

4-5-8

7-9-10

G R

A

PH

IC

L

O G

Remarks:

SA

M

PL

E

TY

PE

N U

M B

ER

Operator: Dan J Fischer Excavating

Drilling Method: 4.5" Core / 4 3/8" Auger

Groundwater at end of drilling: ---

Checked By: Blayne Sandau Logged By: Adrian Cadena

Approximate Ground Elevation:

Approximate Location Coordinates:

Lat: Long:

LA

B

R

ES

U

LT

S/ R

EM

A

R K

S

Date Completed:

12/28/23

Date Started:

12/28/23 Groundwater first observed: --- Groundwater Not Observed

Equipment: Trailer Mounted Drill Rig

D

EP

TH

ft

BORING LOG B-8

MATERIAL DESCRIPTION

Client: Keller Associates

Project: Corvallis Road Water Line Improvements

Location: Corvallis Road, Independence, OR

Project No:

Independence-3-01

B

O R

IN

G

T

EM

PL

A

TE

_2

C

G S

B O

R

IN

G L

O G

.G D

T

/1

/2

:4

C

U

SE

R S\

C G

SU

SE

R \C

EN

TR

A L

G

EO

TE

C

H N

IC

A

L

SE

R V

IC

ES

\C G

S

P R

O

JE

C

TS

\I -Q

\I N

D

EP

EN

D

EN

C

E\

IN

D

EP

EN

D

EN

C

E-

\I N

D

EP

EN

D

EN

C

E-

-0

\F

IE

LD

E

X

PL

O R

A

TI

O N

\2 _F

IE

LD

A N

D D

R A

FT

L

O G

S\

IN

D

EP

EN

D

EN

C

E-

-0

L O

G S.

G P

J Central Geotechnical Services 10240 SW Nimbus Ave, Suite L6 Portland, OR 97223 Telephone: (503) 616-9419

M O

IS

TU

R E

R

EC

O V

ER

Y in

B

LO

W C

O U

SS

S-2

SS

S-3

SS

S-4

1.1 1.2

2.5

11.5

ASPHALT CONCRETE (13.0-inches)

AGGREGATE BASE (1.5-inches) stiff, gravelly SILT(ML), with fine to medium sand, brown, moist

(FILL)

Stiff, SILT (ML), with fine sand, brown with orange and gray mottling, moist becomes very stiff @ 10-ft bgs

Boring terminated at 11.5 feet bgs

10-7-6

4-7-5

8-10-11

G R

A

PH

IC

L

O G

Remarks:

SA

M

PL

E

TY

PE

N U

M B

ER

Operator: Dan J Fischer Excavating

Drilling Method: 4.5" Core / 4 3/8" Auger

Groundwater at end of drilling: ---

Checked By: Blayne Sandau Logged By: Adrian Cadena

Approximate Ground Elevation:

Approximate Location Coordinates:

Lat: Long:

LA

B

R

ES

U

LT

S/ R

EM

A

R K

S

Date Completed:

12/28/23

Date Started:

12/28/23 Groundwater first observed: --- Groundwater Not Observed

Equipment: Trailer Mounted Drill Rig

D

EP

TH

ft

BORING LOG B-9

MATERIAL DESCRIPTION

Client: Keller Associates

Project: Corvallis Road Water Line Improvements

Location: Corvallis Road, Independence, OR

Project No:

Independence-3-01

B

O R

IN

G

T

EM

PL

A

TE

_2

C

G S

B O

R

IN

G L

O G

.G D

T

/1

/2

:4

C

U

SE

R S\

C G

SU

SE

R \C

EN

TR

A L

G

EO

TE

C

H N

IC

A

L

SE

R V

IC

ES

\C G

S

P R

O

JE

C

TS

\I -Q

\I N

D

EP

EN

D

EN

C

E\

IN

D

EP

EN

D

EN

C

E-

\I N

D

EP

EN

D

EN

C

E-

-0

\F

IE

LD

E

X

PL

O R

A

TI

O N

\2 _F

IE

LD

A N

D D

R A

FT

L

O G

S\

IN

D

EP

EN

D

EN

C

E-

-0

L O

G S.

G P

J Central Geotechnical Services 10240 SW Nimbus Ave, Suite L6 Portland, OR 97223 Telephone: (503) 616-9419

M O

IS

TU

R E

R

EC

O V

ER

Y in

B

LO

W C

O U

SS

SS

S-2

SS

S-3

SS

S-4

1.5

1.8

3.5

11.5

ASPHALT CONCRETE (18.0-inches)

AGGREGATE BASE (4.0-inches)

Stiff, gravelly SILT(ML), gravels are rounded, brown, moist

(FILL)

Stiff, SILT(ML), trace gravel, gray, moist becomes very stiff @ 5-ft bgs

Boring terminated at 11.5 feet bgs

17-3-7

7-9-12

10-12-13

G R

A

PH

IC

L

O G

Remarks:

SA

M

PL

E

TY

PE

N U

M B

ER

Operator: Dan J Fischer Excavating

Drilling Method: 4.5" Core / 4 3/8" Auger

Groundwater at end of drilling: ---

Checked By: Blayne Sandau Logged By: Adrian Cadena

Approximate Ground Elevation:

Approximate Location Coordinates:

Lat: Long:

LA

B

R

ES

U

LT

S/ R

EM

A

R K

S

Date Completed:

12/28/23

Date Started:

12/28/23 Groundwater first observed: --- Groundwater Not Observed

Equipment: Trailer Mounted Drill Rig

D

EP

TH

ft

BORING LOG B-10

MATERIAL DESCRIPTION

Client: Keller Associates

Project: Corvallis Road Water Line Improvements

Location: Corvallis Road, Independence, OR

Project No:

Independence-3-01

B

O R

IN

G

T

EM

PL

A

TE

_2

C

G S

B O

R

IN

G L

O G

.G D

T

/1

/2

:4

C

U

SE

R S\

C G

SU

SE

R \C

EN

TR

A L

G

EO

TE

C

H N

IC

A

L

SE

R V

IC

ES

\C G

S

P R

O

JE

C

TS

\I -Q

\I N

D

EP

EN

D

EN

C

E\

IN

D

EP

EN

D

EN

C

E-

\I N

D

EP

EN

D

EN

C

E-

-0

\F

IE

LD

E

X

PL

O R

A

TI

O N

\2 _F

IE

LD

A N

D D

R A

FT

L

O G

S\

IN

D

EP

EN

D

EN

C

E-

-0

L O

G S.

G P

J Central Geotechnical Services 10240 SW Nimbus Ave, Suite L6 Portland, OR 97223 Telephone: (503) 616-9419

M O

IS

TU

R E

R

EC

O V

ER

Y in

B

LO

W C

O U

Note: This report may not be reproduced, except in full, without written approval of Central Geotechnical Services, LLC. Test results are applicable only to the specific sample on which they were performed and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes.

The liquid limit and plasticity index were obtained in general accordance with ASTM D 4318.

Figure A-12

Atterberg Limits Test Results

Corvallis Road Water Line Improvements Independence, Oregon

In d ep en d en ce -3

-0

D at e Ex p o rt ed

/1 8/

Symbol Boring

Number Depth (feet)

Moisture Content

Liquid Limit

Plasticity Index

Soil Description

B-3 5 28.9 Clay (CH)

0 10 20 30 40 50 60 70 80 90 100

P L A

S T

IC

IT

Y

I N

D E

X

LIQUID LIMIT

PLASTICITY CHART

CL-ML ML or OL

CL or OL

OH or MH

CH or OH

56 31