Carlson Geotechnical Bend Office (541) 330-9155 Eugene Office … · 2020. 9. 1. · civil plans...

Carlson Geotechnical 4060 Hudson Avenue NE, Salem, Oregon 97301

Carlson Geotechnical A division of Carlson Testing, Inc. Phone: (503) 601-8250 Fax: (503) 601-8254

Bend Office Eugene Office Salem Office Tigard Office

(541) 330-9155 (541) 345-0289 (503) 589-1252 (503) 684-3460

Report of

Limited Geotechnical Investigation

ODVA Lebanon Parking Lot Expansion & Swale Crossings

Reeves Parkway & North 5th Street

Lebanon, Oregon

CGT Project Number G1804791

Prepared for

Oregon Department of Veterans Affairs (ODVA)

Attn: Mr. John Osborn

700 Summer Street NE

Salem, Oregon 97301

August 6, 2018


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August 6, 2018

Carlson Geotechnical of 17

TABLE OF CONTENTS

1.0 INTRODUCTION .................................................................................................................................... 4 1.1 Project Information ........................................................................................................................... 4 1.2 Scope of Services ............................................................................................................................. 4

2.0 SITE DESCRIPTION .............................................................................................................................. 5 2.1 Site Geology ...................................................................................................................................... 5 2.2 Site Surface Conditions ................................................................................................................... 5

3.0 FIELD INVESTIGATION ........................................................................................................................ 5 3.1 Overview ............................................................................................................................................ 5 3.2 Drilled Borings .................................................................................................................................. 5 3.3 Hand Auger Boring ........................................................................................................................... 6 3.4 Soil Classification & Sampling ........................................................................................................ 6

4.0 LABORATORY TESTING ...................................................................................................................... 6 5.0 SUBSURFACE CONDITIONS ............................................................................................................... 6

5.1 Soils ................................................................................................................................................... 6 5.2 Groundwater...................................................................................................................................... 7

6.0 CONCLUSIONS ..................................................................................................................................... 7 7.0 RECOMMENDATIONS .......................................................................................................................... 8

7.1 Site Preparation ................................................................................................................................ 8 7.2 Temporary Excavations ................................................................................................................. 10 7.3 Wet Weather Considerations ......................................................................................................... 11 7.4 Structural Fill ................................................................................................................................... 12 7.5 Floor Slabs & Hardscaping Features ............................................................................................ 14 7.6 Pavements ....................................................................................................................................... 15 7.7 Additional Considerations ............................................................................................................. 15

8.0 RECOMMENDED ADDITIONAL SERVICES ...................................................................................... 16 8.1 Design Review................................................................................................................................. 16 8.2 Observation of Construction ......................................................................................................... 16

9.0 LIMITATIONS ....................................................................................................................................... 16

ATTACHMENTS

Site Location ........................................................................................................................................... Figure 1

Site Plan (Parking Lot) .......................................................................................................................... Figure 2

Site Plan (South Swale Crossing) ........................................................................................................ Figure 3

Site Photographs .................................................................................................................................... Figure 4

Soil Classification & Terminology ........................................................................................................... Figure 5

Boring Logs ......................................................................................................................... Figures 6 through 12


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1.0 INTRODUCTION

Carlson Geotechnical (CGT), a division of Carlson Testing, Inc. (CTI), is pleased to submit this report

summarizing the results of our geotechnical investigation for the proposed ODVA Lebanon Parking Lot

Expansion & Swale Crossings project. The project site is located at the southwest quadrant of the

intersection of Reeves Parkway & North 5th Street in Lebanon, Oregon, as shown on the attached Site

Location, Figure 1.

CGT previously performed a geotechnical investigation of the subject ODVA facility, the results of which

were presented in our “Report of Geotechnical Investigation & Site-Specific Seismic Hazards Study”, dated

August 17, 2012. CGT also provided geotechnical construction observations and testing (soil special

inspections) during mass grading of the project in 2012 and 2013.

1.1 Project Information

CGT developed an understanding of the proposed project based on our correspondence and review of the

updated project civil plans, prepared by June 11, 2017, prepared by DevCo Engineering Inc. (Devco) and

subsequent correspondence with CB|2 Architects. The proposed layout drawings depicting the two project

areas were reproduced and are shown on the attached Site Plans, Figures 2 and 3. Based on our review,

we understand the project will include:

Parking Lot: Construction of a new passenger car parking lot and appurtenant underground utilities

within a grass field located west of the existing ODVA facility. The parking lot will be accessed via

Hansard Avenue through a new drive lane. The parking lot and drive lane will be surfaced with asphalt

concrete. Design of pavement sections will rest with others. Permanent grade changes at the relatively

level site will include maximum cuts and fills on the order of 3 feet in depth to achieve design grades.

Swale Crossings: Construction of two swale crossings at the existing ODVA facility. The first crossing

(Crossing #1) will be located along the west site border and provide pedestrian access to the new parking

lot. The second crossing (Crossing #2) will be located along the south site border and provide pedestrian

access to an off-site school. Pedestrian bridges were initially proposed at these locations; however, the

most recent plans include the installation of culverts, structural fill, and sidewalks.

1.2 Scope of Services

Our scope of work included the following:

Contact the Oregon Utilities Notification Center and subcontract a private utility locating service to mark

the locations of public and private utilities within a 30-foot radius of our explorations at the site.

Explore subsurface conditions at the site by advancing six drilled borings and one hand auger boring to

depths of up to about 21½ feet below ground surface (bgs).

Classify the materials encountered in the borings in general accordance with American Society for

Testing and Materials (ASTM) D2488 (Visual-Manual Procedure).

Provide a technical narrative describing surface and subsurface deposits, and local geology of the site,

based on the results of our explorations and published geologic mapping.

Provide geotechnical recommendations for site preparation and earthwork, including subgrade

preparation for the proposed culverts.

Provide geotechnical engineering recommendations for use in design and construction of pavements

and hardscaping features (e.g. sidewalks).


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Provide this written report summarizing the results of our geotechnical investigation and

recommendations for the project.

2.0 SITE DESCRIPTION

2.1 Site Geology

Available geological mapping1 indicates that the site is underlain by Quaternary alluvium, consisting of

coarse-grained (i.e. sand, gravel, and cobbles) and fine-grained (i.e. silt and clay) sediments deposited by

the South Santiam River and its tributaries. The textural soils map included with the referenced geologic

mapping indicates that the alluvium in the vicinity of the site consists predominantly of silt and clay. The

mapping indicates that the alluvium is on the order of a few tens of feet thick, and underlain by interfingered

crystalline volcanic rocks and volcaniclastic rocks.

2.2 Site Surface Conditions

At the time of our field investigation, the area of the proposed parking lot expansion was relatively level and

surfaced with short grasses. Similarly, the swale crossing areas were generally located within shallow,

landscaped swales located adjacent to existing pavements at the ODVA facility. The crossing areas were

concaved and served as drainages, with up to about 3 feet of vertical relief. Site conditions at the time of

our field investigation are shown on Photographs 1 through 4, attached as Figure 4.

3.0 FIELD INVESTIGATION

3.1 Overview

Our field investigation included the advancement of six drilled borings and one hand auger boring on May 18,

2018. The approximate exploration locations are shown on the Site Plans, Figures 2 and 3. The exploration

locations shown therein were determined based on measurements from existing site features (fenced site

corners, etc.) and should be considered approximate.

3.2 Drilled Borings

Six drilled borings (B-1 through B-6) were advanced at the site to depths ranging from about 6½ to 21½ feet

bgs using a CME 55 track-mounted drill rig provided and operated by our subcontractor, Western States Soil

Conservation of Hubbard, Oregon. The borings were advanced using the hollow-stem auger drilling

technique. Upon completion, the borings were backfilled with cuttings and granular bentonite. Drilling waste

(cuttings) were left on-site.

Standard Penetration Tests (SPTs) were conducted within the borings using a split-spoon sampler in general

accordance with ASTM D1586. The SPT is performed by driving a 2-inch, outside-diameter, split-spoon

sampler into the undisturbed formation located at the bottom of the advanced boring with repeated blows of a

140 pound, automatic hammer falling a vertical distance of 30 inches. The number of blows (N-value)

required to drive the sampler the last 12 inches of an 18-inch sample interval is used to characterize the soil

consistency or relative density. The SPTs were conducted at 2½- to 5-foot intervals to the termination

depths of the borings. The CME-55 drill rig was equipped with a 140-pound, automatic hammer, which was

used to conduct the SPTs. It should be noted automatic hammers generally produce lower SPT values than

1 Beaulieu, J.D., Hughes, P.W. and Mathoit, R.K., 1974, Environmental geology of western Linn County: Oregon Department of

Geology and Mineral Industries, Bulletin 84, scale 1:62500.


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those obtained using a traditional safety hammer (cathead). According to the driller, the automatic hammer

on the CME-75HT drill rig had hammer efficiency (ETRhammer) of 81.2 percent, resulting in an efficiency factor

of about 1.35. We have considered this in our description of soil relative density and in our evaluation of soil

strength and compressibility.

3.3 Hand Auger Boring

One hand auger boring (HA-1) was advanced at the site to a depth of about 8¼ feet bgs using a manual,

3-inch-diameter, hand auger provided and operated by CGT. The hand auger boring was terminated at the

said depth due to practical refusal. Practical refusal occurs when the auger cannot be advanced further,

often due to coarse gravel particles in the soil. The hand auger boring was loosely backfilled with the

excavated materials upon completion.

3.4 Soil Classification & Sampling

Soil samples were obtained at the indicated intervals in the drilled borings using the referenced split-spoon

(SPT) sampler and thin-walled, steel (Shelby) tube samplers. Grab samples were collected as the hand

auger boring was advanced. A member of CGT’s geotechnical staff logged the soils observed within the

borings in general accordance with the Visual-Manual Procedure (ASTM D2488). An explanation of this

classification procedure is presented on the attached Figure 5. All SPT and grab samples collected at the

site were stored in sealable plastic bags and were transported along with the Shelby tube samples to our

laboratory for further examination and testing. Our geotechnical staff visually examined all samples returned

to our laboratory in order to refine the initial field classifications.

4.0 LABORATORY TESTING

Laboratory testing was performed on samples collected in the field to refine our initial field classifications and

determine in-situ parameters. Laboratory testing included ten moisture content determinations (ASTM

D2216), two Atterberg limits (plasticity) tests (ASTM D4318), and one Shelby Tube Unit Weight test (ASTM

D2937). Results of the laboratory tests are shown on the respective exploration logs.

5.0 SUBSURFACE CONDITIONS

Logs of the explorations are presented on the attached Boring Logs, Figures 6 through 12. Surface

elevations indicated on the logs were estimated based on the provided topographic survey included in the

civil plans set and should be considered approximate. The following describes the subsurface conditions

encountered at the site.

5.1 Soils

Organic Soil (OL): Organic soil (topsoil) was encountered at the surface of borings B-1 through B-6, and

extended to depths of about ¼ to ½-foot bgs. The organic soil was generally very soft, brown, moist, and

rooted.

Peat Fill (PT FILL): Peat fill (barkdust) was encountered at the surface of boring HA-1 and was about 2

inches thick.

Lean Clay (CL): Lean clay was encountered below the organic soil and peat fill and extended to depths of

about 5 to 8½ feet bgs in the drilled borings. This soil extended to the full depth explored (about 8¼ feet bgs)


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in boring HA-1. This soil was generally brown to brown with light gray mottling, moist to wet, and exhibited

medium plasticity. In terms of consistency, this soil was generally soft to medium stiff within the west parking

lot and west swale crossing areas. In the area of the south swale crossing (B-6 and HA-1), this soil was

generally very soft to soft in terms of consistency.

Poorly Graded Gravel with Clay (GP-GC): Native poorly graded gravel with clay was encountered below the

lean clay in all drilled borings and extended to the full depths explored, up to about 21½ feet bgs. This

material was medium dense to very dense, dark gray/brown, wet, rounded, and contained varying amounts

of coarse sand and rounded cobbles interpreted to be up to 6 inches in diameter. We interpret this material

was encountered at the bottom of hand auger boring HA-1.

5.2 Groundwater

Groundwater was encountered at depths ranging between 4 to 5½ feet bgs in each of the borings advanced

at the site on May 18, 2018. To determine approximate regional groundwater levels in the area, we

researched well logs available on the Oregon Water Resources Department (OWRD)2 website for wells

located within Section 32, Township 13 South, Range 1 East, Willamette Meridian. Our review indicated that

groundwater levels in the area generally ranged from about 6 to 12 feet bgs. It should be noted groundwater

levels vary with local topography. In addition, the groundwater levels reported on the OWRD logs often

reflect the purpose of the well, so water well logs may only report deeper, confined groundwater, while

geotechnical or environmental borings will often report any groundwater encountered, including shallow,

unconfined groundwater. Therefore, the levels reported on the OWRD well logs referenced above are

considered generally indicative of local water levels and may not reflect actual groundwater levels at the

project site. We anticipate that groundwater levels will fluctuate due to seasonal and annual variations in

precipitation, changes in site utilization, or other factors. In addition, the native lean clay (CL) is conducive to

the formation of perched groundwater tables.

6.0 CONCLUSIONS

Based on the results of our field explorations and analyses, the site may be developed as described in

Section 1.1, provided the recommendations presented in this report are incorporated into the design and

development. Satisfactory subgrade support for planned pavements and hardscaping features can be

achieved by the native, medium stiff to better, lean clay (CL), the native, medium dense to very dense, poorly

graded gravels (GP-GC), or structural fill that is properly placed and compacted on these materials during

construction.

As indicated in Section 5.1 above and shown on the respective boring logs, the native lean clay was found to

be generally soft (boring B-3) and very soft to soft (boring B-6 and HA-1). These borings were located in

close proximity to the planned swale crossings. Remediation of the soft clayey soils is recommended in

order to provide assurance of proper bearing support for the planned culverts, structural fills, and

sidewalks. Geotechnical recommendations for subgrade preparation of the creek crossings are presented in

Section 7.1.5 of this report.

2 Oregon Water Resources Department, 2018. Well Log Records, accessed July 2018, from OWRD web site:

http://apps.wrd.state.or.us/apps/gw/well_log/.

http://apps.wrd.state.or.us/apps/gw/well_log/


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The native lean clay (CL) soils are susceptible to disturbance during wet weather. Trafficability of these soils

may be difficult, and significant damage to the subgrade could occur, if earthwork is undertaken without

proper precautions at times when the exposed soils are more than a few percentage points above optimum

moisture content. In the event construction occurs during wet weather, we recommend measures be

implemented to protect the fine-grained subgrade in areas of repeated construction traffic and in foundation

bearing areas. Geotechnical recommendations for wet weather construction are presented in Section 7.3 of

this report.

7.0 RECOMMENDATIONS

The recommendations presented in this report are based on the information provided to us, results of our

field investigation and analyses, laboratory data, and professional judgment. CGT has observed only a small

portion of the pertinent subsurface conditions. The recommendations are based on the assumptions that the

subsurface conditions do not deviate appreciably from those found during the field investigation. CGT

should be consulted for further recommendations if the design of the proposed development changes and/or

variations or an undesirable geotechnical condition is encountered during site development.

7.1 Site Preparation

7.1.1 Stripping

Existing vegetation and organic soil (OL) should be removed from within, and for a minimum 5-foot margin

around, proposed pavement, hardscaping, and structural fill areas. Based on the results of our explorations,

stripping depths are anticipated to be about ½-foot bgs. Deeper stripping depths are anticipated at and near

the base of the proposed swale crossings. These materials may be deeper or shallower away from our

completed explorations. Accordingly, the geotechnical engineer or their representative should provide

recommendations for actual stripping depths based on observations during site stripping. Vegetation and

rooted soils should be transported off-site for disposal, or stockpiled for later use in landscaped areas.

7.1.2 Existing Utilities & Below-Grade Structures

All existing utilities at the site should be identified prior to excavation. Abandoned utility lines beneath the

new pavements and hardscaping features should be completely removed or grouted full. Soft, loose, or

otherwise unsuitable soils encountered in utility trench excavations should be removed and replaced with

structural fill in conformance with Section 7.4 this report. Buried structures (i.e. footings, foundation walls,

retaining walls, slabs-on-grade, tanks, etc.), if encountered during site development, should be completely

removed and replaced with structural fill in conformance with Section 7.4 of this report.

7.1.3 Grubbing

Grubbing of trees, if required, should include the removal of the root mass and roots greater than ½ inch in

diameter. Grubbed materials should be transported off site for disposal. Root masses from larger trees may

extend several feet bgs. Where root masses are removed, the resulting excavation should be properly

backfilled with structural fill in conformance with Section 7.4 of this report.

7.1.4 Subgrade Preparation – Pavement Areas

7.1.4.1 Dry Weather Construction

After site preparation as recommended above, but prior to placement of structural fill and/or aggregate base,

the geotechnical engineer or his representative should observe a proof roll test of the exposed subgrade


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soils in order to identify areas of excessive yielding. Proof rolling of subgrade soils is typically conducted

during dry weather conditions using a fully-loaded, 10- to 12-cubic-yard, tandem-axle, tire-mounted, dump

truck or equivalent weighted water truck. Areas that appear too soft and wet to support proof rolling

equipment should be prepared in general accordance with the recommendations for wet weather

construction presented in Section 7.3 of this report. If areas of soft soil or excessive yielding are identified,

the affected material should be over-excavated to firm, stable subgrade, and replaced with imported granular

structural fill in conformance with Section 7.4.2 of this report.

7.1.4.2 Wet Weather Construction

Preparation of subgrade soils during wet weather should be in conformance with Section 7.3 of this report.

As indicated therein, increased granular fill (working surfaces) and a geotextile separation fabric may be

required in wet conditions in order to support construction traffic and protect the subgrade. Cement

amendment may also be considered to help stabilize subgrade soils during wet weather.

7.1.5 Swale Crossings – Subgrade Preparation

Due to the presence of soft soils, relatively shallow groundwater, and moisture sensitivity of the near-surface

soils, placement of a geo-grid reinforced, granular mattress below the swale crossings is recommended.

Construction of the geo-grid reinforced, granular mattress should include the following:

Over-excavating the existing soft, native lean clay to a minimum depth of 2 feet below design bottom-of-

culvert elevations3. The over-excavation should extend a minimum of 3 feet laterally (measured

horizontally) of each culvert and structural fill footprint. Geotechnical recommendations for use in

planning of temporary excavations and dewatering are presented in Section 7.2 of this report. The

geotechnical engineer or his representative should be contacted to observe (probe) the finished over-

excavation to confirm suitable subgrade conditions.

Placing non-woven geotextile separation fabric over the exposed subgrade and sidewalls of the over-

excavation. The geotextile fabric should be in conformance with Section 02320 of the current Oregon

Department of Transportation (ODOT) Standard Specification for Construction.

Installing a layer (or multiple layers) of geo-grid, such as Tensar Tri-Ax TX140 or TX160 grid or approved

strength equivalent, over the geotextile fabric. The geo-grid should be installed, overlapped (where

necessary), and pulled taught in conformance with the manufacturer’s recommendations.

Placing and compacting imported granular fill to serve as engineered fill and return grades to design

subgrade elevations. The crushed rock should be in conformance with the recommendations presented

in Section 6.4.2 of this report.

7.1.6 Erosion Control

Erosion and sedimentation control measures should be employed in accordance with applicable City,

County, and State regulations.

3 With regard to the west swale crossing, based on the results of the borings and those completed on the ODVA site in 2012, but

depending on final elevations, the over-excavation may encounter the native, dense to very dense, poorly graded gravel (GP-GC).

In the event the native gravels are encountered, the geotechnical engineer should be contacted to observe subgrade conditions.

Placement of geotextile separation fabric and geo-grid, as detailed above, should not be necessary where native dense gravels are

encountered.


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7.2 Temporary Excavations

7.2.1 Overview

Conventional earthmoving equipment in proper working condition should be capable of making necessary

excavations for the anticipated site cuts as described earlier in this report. All excavations should be in

accordance with applicable OSHA and state regulations. It is the contractor's responsibility to select the

excavation methods, to monitor site excavations for safety, and to provide any shoring required to protect

personnel and adjacent improvements. A “competent person”, as defined by OR-OSHA, should be on-site

during construction in accordance with regulations presented by OR-OSHA. CGT’s current role on the

project does not include review or oversight of excavation safety.

7.2.2 OSHA Soil Type

For use in the planning and construction of temporary excavations up to 10 feet in depth, an OSHA soil type

“C” should be used for the native lean clay (CL) and poorly graded gravels (GP-GC) encountered in the

borings.

7.2.3 Dewatering

As indicated above, groundwater was encountered at depths as shallow as about 4 feet bgs in our

explorations. The soils encountered near-surface generally have relatively high fines content and are

anticipated to exhibit low to moderate rates of transmissivity. Pumping from sumps may be effective in

removing groundwater within shallow or localized excavations at the site. Pumping from multiple well points

will likely be required for larger excavations, particularly those that extend into the native gravels (GP-GC).

The sumps or wells should be installed to remove water to a depth of at least 2 feet below the lowest

elevation of the excavation, and should be installed and put into operation prior to commencing excavation.

The project civil engineer should be consulted to review requirements for disposal of resultant discharge. In

order to refine groundwater levels and estimate flow rates, piezometers or well points could be installed and

drawdown tests could be performed prior to, or at the onset of, construction.

7.2.4 Utility Trenches

Temporary trench cuts should stand near vertical to depths of approximately 4 feet in the native lean clay

(CL) and poorly graded gravels (GP-GC) encountered at the site. Some instability may occur in coarse-

grained soils, particularly if allowed to dry or if seepage occurs. If seepage undermines the stability of the

trench, or if sidewall caving is observed during excavation, the sidewalls should be flattened or shored.

Depending on the time of year trench excavations occur, trench dewatering may be required in order to

maintain dry working conditions, particularly if the invert elevations of the proposed utilities are below the

groundwater level. A discussion of dewatering of temporary excavations is presented in Section 7.2.3

above. If groundwater is present at the base of utility excavations, we recommend placing trench

stabilization material at the base of the excavations. Trench stabilization material should be in conformance

with Section 7.4.4 of this report.

7.2.5 Excavations Near Foundations

Excavations near footings should not extend within a 1H:1V (horizontal:vertical) plane projected out and

down from the outside, bottom edge of the footings. In the event excavation needs to extend below the

referenced plane, temporary shoring of the excavation and/or underpinning of the subject footing may be


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required. The geotechnical engineer should be consulted to review proposed excavation plans for this

design case to provide specific recommendations.

7.3 Wet Weather Considerations

For planning purposes, the wet season should be considered to extend from late September to late June. It

is our experience that dry weather working conditions should prevail between early July and mid-September.

Notwithstanding the above, soil conditions should be evaluated in the field by the geotechnical engineer or

his representative at the initial stage of site preparation to determine whether the recommendations within

this section should be incorporated into construction.

7.3.1 Overview

Due to its fines content, the on-site native lean clay (CL) is susceptible to disturbance during wet weather.

To a lesser degree, depending on the fines content, the poorly graded gravels (GP-GC) may also be

susceptible to disturbance during wet weather. Trafficability of these soils may be difficult, and significant

damage to subgrade soils could occur, if earthwork is undertaken without proper precautions at times when

the exposed soils are more than a few percentage points above optimum moisture content. For wet weather

construction, site preparation activities may need to be accomplished using track-mounted equipment,

loading removed material onto trucks supported on granular haul roads, or other methods to limit soil

disturbance. The geotechnical engineer or his representative should evaluate the subgrade during

excavation by probing rather than proof rolling. Soils that have been disturbed during site preparation

activities, or soft or loose areas identified during probing, should be over-excavated to firm, stable subgrade,

and replaced with imported granular structural fill in conformance with Section 7.4.2 of this report.

7.3.2 Geotextile Separation Fabric

We recommend a geotextile separation fabric be placed to serve as a barrier between the prepared

subgrade and granular fill/base rock in areas of repeated or heavy construction traffic. The geotextile fabric

should meet the requirements presented in the current Oregon Department of Transportation (ODOT)

Standard Specification for Construction, Section 02320.

7.3.3 Granular Working Surfaces (Haul Roads & Staging Areas)

Haul roads subjected to repeated heavy, tire-mounted, construction traffic (e.g. dump trucks, concrete trucks,

etc.) will require a minimum of 18 inches of imported granular material. For light staging areas, 12 inches of

imported granular material is typically sufficient. Additional granular material, geo-grid reinforcement, or

cement amendment may be recommended based on site conditions and/or loading at the time of

construction. The imported granular material should be in conformance with Section 7.4.2 and have less

than 5 percent material passing the U.S. Standard No. 200 Sieve. The prepared subgrade should be

covered with geotextile fabric prior to placement of the imported granular material. The imported granular

material should be placed in a single lift (up to 24 inches deep) and compacted using a smooth-drum, non-

vibratory roller until well-keyed.

7.3.4 Cement Amendment

It is sometimes less costly to amend near-surface, moisture-sensitive, fine-grained soils with Portland

cement than to remove and replace those soils with imported granular material. Successful use of soil

cement amendment depends on the use of correct techniques and equipment, soil moisture content, and the


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amount of cement added to the subgrade (mix design). We anticipate the native lean clay (CL) is conducive

to cement amendment due to its generally medium plasticity and experience with similar soils.

The recommended percentage of cement is based on soil moisture contents at the time the work is

performed. Based on our experience, 3 percent cement by weight of dry soil can generally be used when

the soil moisture content does not exceed approximately 20 percent. If the soil moisture content is in the

range of 25 to 35 percent, 4 to 6 percent by weight of dry soil is recommended. It is difficult to accurately

predict field performance due to the variability in soil response to cement amendment. The amount of

cement added to the soil may need to be adjusted based on field observations and performance.

If cement amendment is considered, we recommend additional sampling, laboratory testing, and a mix

design be performed to determine the level of improvement in engineering properties (strength, stiffness) of

the on-site soils when blended with Portland cement. We recommend project scheduling allow for a

minimum of 3 weeks for this testing and design to be completed, prior to initiating cement amendment.

7.4 Structural Fill

The geotechnical engineer should be provided the opportunity to review all materials considered for use as

structural fill. The geotechnical engineer or his representative should be contacted to evaluate compaction of

structural fill as the material is being placed. Evaluation of compaction may take the form of in-place density

tests and/or proof roll tests with suitable equipment. Structural fill should be evaluated at intervals not

exceeding every 2 vertical feet as the fill is being placed.

7.4.1 On-Site Soils – General Use

7.4.1.1 Lean Clay (CL)

Re-use of this soil as structural fill may be difficult because it is sensitive to small changes in moisture

content and difficult, if not impossible, to adequately compact during wet weather. We anticipate the

moisture content of this soil will be higher than the optimum moisture content for satisfactory compaction.

Therefore, moisture conditioning (drying) should be expected in order to achieve adequate compaction. If

excavated and re-used as structural fill, this soil should be free of organic matter, debris, and particles larger

than 4 inches. When used as structural fill, this soil should be placed in lifts with a maximum thickness of

about 8 inches at moisture contents within –1 and +3 percent of optimum, and compacted to not less than

92 percent of the material’s maximum dry density, as determined in general accordance with ASTM D1557

(Modified Proctor).

7.4.1.2 Poorly Graded Gravels (GP-GC)

Re-use of these relatively clean granular materials as structural fill is feasible, provided they can be kept free

of debris, deleterious materials, and particles larger than 4 inches in diameter. Processing (removal) of

cobbles in excess of 4 inches in diameter will be required and should be factored. If used as structural fill,

these materials should be prepared in conformance with Section 7.4.2 of this report.

If the on-site materials cannot be properly moisture-conditioned and/or processed, we recommend using

imported granular material for structural fill.


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7.4.2 Imported Granular Structural Fill – General Use

Imported granular structural fill should consist of angular pit or quarry run rock, crushed rock, or crushed

gravel that is fairly well graded between coarse and fine particle sizes. The granular fill should contain no

organic matter, debris, or particles larger than 4 inches, and have less than 5 percent material passing the

U.S. Standard No. 200 Sieve. For fine-grading purposes, we recommend the maximum particle size be

limited to 1½ inches. The percentage of fines can be increased to 12 percent of the material passing the

U.S. Standard No. 200 Sieve if placed during dry weather, and provided the fill material is moisture-

conditioned, as necessary, for proper compaction. Imported granular fill material should be compacted to not

less than 95 percent of the material’s maximum dry density, as determined in general accordance with ASTM

D1557 (Modified Proctor). Proper moisture conditioning and the use of vibratory equipment will facilitate

compaction of these materials.

Granular fill materials with high percentages of particle sizes in excess of 1½ inches are considered non-

moisture-density testable materials. As an alternative to conventional density testing, compaction of these

materials should be evaluated by periodic proof roll test observation (deflection test) in accordance with

ODOT Test Method 158. Such materials should be “capped” with a minimum of 12 inches of ¾-inch-minus

(or finer) granular fill under all structural elements (footings, concrete slabs, etc.).

7.4.3 Floor Slab (Sidewalk) Base Rock

Floor slab base rock should consist of well-graded granular material (crushed rock) containing no organic

matter or debris, have a maximum particle size of ¾ inch, and have less than 5 percent material passing the

U.S. Standard No. 200 Sieve. Floor slab base rock should be placed in one lift and compacted to not less

than 95 percent of the material’s maximum dry density as determined in general accordance with

ASTM D1557 (Modified Proctor).

7.4.4 Trench Base Stabilization Material

If groundwater is present at the base of utility excavations, trench base stabilization material should be

placed. Trench base stabilization material should consist of a minimum of 1 foot of well-graded granular

material with a maximum particle size of 4 inches and less than 5 percent material passing the U.S. Standard

No. 4 Sieve. The material should be free of organic matter and other deleterious material, placed in one lift,

and compacted until well-keyed.

7.4.5 Trench Backfill Material

Trench backfill for the utility pipe base and pipe zone should consist of granular material as recommended by

the utility pipe manufacturer. Trench backfill above the pipe zone should consist of well-graded granular

material containing no organic matter or debris, have a maximum particle size of ¾ inch, and have less than

8 percent material passing the U.S. Standard No. 200 Sieve. As a guideline, trench backfill should be placed

in maximum 12-inch-thick lifts. The earthwork contractor may elect to use alternative lift thicknesses based

on their experience with specific equipment and fill material conditions during construction in order to achieve

the required compaction. The following table presents recommended relative compaction percentages for

utility trench backfill.


Lebanon, Oregon


August 6, 2018


Table 1 Utility Trench Backfill Compaction Recommendations

Backfill Zone Recommended Minimum Relative Compaction

Structural Areas1 Landscaping Areas

Pipe Base and Within Pipe Zone 90% ASTM D1557 or pipe

manufacturer’s recommendation

88% ASTM D1557 or pipe

manufacturer’s recommendation

Above Pipe Zone 92% ASTM D1557 90% ASTM D1557

Within 3 Feet of Design Subgrade 95% ASTM D1557 90% ASTM D1557

1Includes pavement areas, structural fill areas, exterior hardscaping, etc.

7.4.6 Controlled Low-Strength Material (CLSM)

CLSM is a self-compacting, cementitious material that is typically considered when backfilling localized

areas. CLSM is sometimes referred to as “controlled density fill” or CDF. Due to its flowable characteristics,

CLSM typically can be placed in restricted-access excavations where placing and compacting fill is difficult.

If chosen for use at this site, we recommend the CLSM be in conformance with Section 00442 of the most

recent, State of Oregon, Standard Specifications for Highway Construction. The geotechnical engineer’s

representative should observe placement of the CLSM and obtain samples for compression testing in

accordance with ASTM D4832. As a guideline, for each day’s placement, two compressive strength

specimens from the same CLSM sample should be tested. The results of the two individual compressive

strength tests should be averaged to obtain the reported 28-day compressive strength. If CLSM is

considered for use on this site, the geotechnical engineer should be consulted for site-specific and

application-specific recommendations.

7.5 Floor Slabs & Hardscaping Features

7.5.1 Subgrade Preparation

Satisfactory subgrade support for slabs constructed on grade, supporting up to 200 psf area loading, can be

obtained from the native, medium stiff to better, lean clay (CL), the native, medium dense to better, poorly

graded gravels (GP-GC), or new structural fill that is properly placed and compacted on these materials

during construction. The geotechnical engineer or his representative should observe floor slab subgrade

soils to evaluate surface consistencies. If soft, loose, or otherwise unsuitable soils are encountered, they

should be over-excavated as recommended by the geotechnical representative at the time of construction.

The resulting over-excavation should be brought back to grade with imported granular structural fill as

described in Section 7.4.2 of this report.

7.5.2 Crushed Rock Base

Concrete floor slabs should be supported on a minimum 6-inch-thick layer of crushed rock (base rock) in

conformance with Section 7.4.3 of this report. The surface of the base rock should be “choked” with sand

just prior to concrete placement. Choking means the voids between the largest aggregate particles are filled

with sand, but does not provide a layer of sand above the base rock. Choking the base rock surface reduces

the lateral restraint on the bottom of the concrete during curing when a vapor barrier is not used above the

base rock. Choking helps reduce puncturing of the vapor barrier due to foot traffic when one is used.


Lebanon, Oregon


August 6, 2018


7.5.3 Design Considerations

For floor slabs constructed as recommended, a modulus of subgrade reaction of 100 pounds per cubic inch

(pci) is recommended for the design of the floor slab. Floor slabs constructed as recommended will likely

settle less than ½-inch. For general floor slab construction, slabs should be jointed around columns and

walls to permit slabs and foundations to settle differentially.

7.5.4 Subgrade Moisture Considerations

Liquid moisture and moisture vapor should be expected at the subgrade surface. The recommended

crushed rock base is anticipated to provide protection against liquid moisture. Where moisture vapor

emission through the slab must be minimized, e.g. impervious floor coverings, storage of moisture sensitive

materials directly on the slab surface, etc., a vapor retarding membrane or vapor barrier below the slab

should be considered. Factors such as cost, special considerations for construction, floor coverings, and

end use suggest that the decision regarding a vapor retarding membrane or vapor barrier be made by the

architect and owner.

If a vapor retarder or vapor barrier is placed below the slab, its location should be based on current American

Concrete Institute (ACI) guidelines, ACI 302 Guide for Concrete Floor and Slab Construction. In some

cases, this indicates placement of concrete directly on the vapor retarder or barrier. Please note that the

placement of concrete directly on impervious membranes increases the risk of plastic shrinkage cracking and

slab curling in the concrete. Construction practices to reduce or eliminate such risk, as described in ACI 302,

should be employed during concrete placement.

7.6 Pavements

Satisfactory subgrade support for pavements can be obtained from the native, medium stiff to better, lean

clay (CL), the native, medium dense to better, poorly graded gravels (GP-GC), or new structural fill that is

properly placed and compacted on these materials during construction. Pavement subgrade preparation

should be in conformance with Section 7.1.4 of this report. Pavement subgrade surfaces should be crowned

(or sloped) for proper drainage in accordance with specifications provided by the project civil engineer.

This assignment did not include development of recommendations for design pavement sections. We

understand pavement section design will rest with others. In the event pavement design recommendations

are desired, we would be pleased to provide such recommendations, upon request, for an additional fee.

7.7 Additional Considerations

7.7.1 Drainage

Subsurface drains, if incorporated, should be connected to the nearest storm drain or other suitable

discharge point. Paved surfaces and grading near or adjacent to new structures should be sloped to drain

away from the structures. Surface water from paved surfaces and open spaces should be collected and

routed to a suitable discharge point.

7.7.2 Expansive Potential

The near surface native soils consist of medium plasticity lean clay (CL) and granular materials (GP-GC).

These soils are not considered to be susceptible to appreciable movements from changes in moisture


Lebanon, Oregon


August 6, 2018


content. Accordingly, no special considerations are required to mitigate expansive potential of the near

surface soils at the site.

8.0 RECOMMENDED ADDITIONAL SERVICES

8.1 Design Review

Geotechnical design review is of paramount importance. We recommend the geotechnical design review

take place prior to releasing bid packets to contractors.

8.2 Observation of Construction

Satisfactory earthwork, floor slab, and pavement performance depends to a large degree on the quality of

construction. Sufficient observation of the contractor’s activities is a key part of determining that the work is

completed in accordance with the construction drawings and specifications. Subsurface conditions observed

during construction should be compared with those encountered during subsurface explorations, and

recognition of changed conditions often requires experience. We recommend that qualified personnel visit

the site with sufficient frequency to detect whether subsurface conditions change significantly from those

observed to date and anticipated in this report. We recommend the geotechnical engineer or their

representative attend a pre-construction meeting coordinated by the contractor and/or developer. The

project geotechnical engineer or their representative should provide observations and/or testing of at least

the following earthwork elements during construction:

Site Stripping and Grubbing

Subgrade Preparation for Structural Fills, Floor Slabs, and Pavements

Compaction of Structural Fill and Utility Trench Backfill

Compaction of Base Rock for Floor Slabs & Pavements

Compaction of HMAC for Pavements

It is imperative that the owner and/or contractor request earthwork observations and testing at a frequency

sufficient to allow the geotechnical engineer to provide a final letter of compliance for the earthwork activities.

9.0 LIMITATIONS

At our client’s request, the scope of our evaluation was limited to the scope of services described in this

report. Other geotechnical considerations described in the 2014 Oregon Structural Specialty Code (OSSC)

have not been addressed. Accordingly, this evaluation must be considered “limited”. A more comprehensive

evaluation may be completed if requested by our client, for an additional fee. Such evaluation would include,

but not be limited to: assessment of seismic/geologic hazards at the site, recommendations for seismic

design criteria, and other geotechnical considerations. The responsibility for determining the sufficiency of

our evaluation to meet the project needs rests solely with the owner and not with CGT. Please contact us if

additional evaluation is desired.

We have prepared this report for use by ODVA and other members of the design and construction team for

the proposed development. The opinions and recommendations contained within this report are not

intended to be, nor should they be construed as a warranty of subsurface conditions, but are forwarded to

assist in the planning and design process.


Lebanon, Oregon


August 6, 2018


We have made observations based on our explorations that indicate the soil conditions at only those specific

locations and only to the depths penetrated. These observations do not necessarily reflect soil types, strata

thickness, or water level variations that may exist between or away from our explorations. If subsurface

conditions vary from those encountered in our site explorations, CGT should be alerted to the change in

conditions so that we may provide additional geotechnical recommendations, if necessary. Observation by

experienced geotechnical personnel should be considered an integral part of the construction process.

The owner/developer is responsible for ensuring that the project designers and contractors implement our

recommendations. When the design has been finalized, prior to releasing bid packets to contractors, we

recommend that the design drawings and specifications be reviewed by our firm to see that our

recommendations have been interpreted and implemented as intended. If design changes are made, we

request that we be retained to review our conclusions and recommendations and to provide a written

modification or verification. Design review and construction phase testing and observation services are

beyond the scope of our current assignment, but will be provided for an additional fee.

The scope of our services does not include services related to construction safety precautions, and our

recommendations are not intended to direct the contractor’s methods, techniques, sequences, or

procedures, except as specifically described in our report for consideration in design.

Geotechnical engineering and the geologic sciences are characterized by a degree of uncertainty.

Professional judgments presented in this report are based on our understanding of the proposed

construction, familiarity with similar projects in the area, and on general experience. Within the limitations of

scope, schedule, and budget, our services have been executed in accordance with the generally accepted

practices in this area at the time this report was prepared; no warranty, expressed or implied, is made. This

report is subject to review and should not be relied upon after a period of three years.

Site LocationCARLSON

GEOTECHNICAL

503-601-8250

1 Inch = 2,000 feet

0 2000 4000

FIGURE 1

Map created with TOPO!™, © 2006 National Geographic HoldingsUSGS 7.5 Minute Topographic Map Series, Lebanon, Oregon Quadrangle,1986.Township 12 South, Range 2 West, Section 43 Willamette Meridian

SITE

Latitude: 44.551602° NorthLongitude: 122.91618° West

N

ODVA LEBANON PARKING LOT EXPANSION - LEBANON, OREGONProject Number G1804853

Drafted by: ALS

Site Plan 1

CARLSON

GEOTECHNICAL

503-601-8250

N

LEGEND

NOTES: Drawing based on observations made while onsite and Site Clearing Plan produced by DEVCO Engi-neering, Inc. dated 06/15/18. All locations are approxi-mate.

0 80 160

1 Inch = 80 Feet

2

3

1

SCALE: 1" = 20’

SCALE IN FEET

B-1 B-2

B-3

B-4B-5


Orientation of site photographs shown on Figure 41

B-1 Drilled boring

Drafted by: ALS

FIGURE 2

CARLSON

GEOTECHNICAL

503-601-8250

Site Plan 2

SCALE: 1" = 10’

SCALE IN FEET

B-6

HA-1

4

N

LEGEND


FIGURE 3

0 20 40

NOTES: Drawing based on observations made while on site and South SwaleCrossing Plans and Details produced by DEVCO Engineering, Inc dated06/15/2018. All locations are approximate.

1 Inch = 20 Feet

Drafted by: ALS/BMW

Orientation of site photographs shown on Figure 41

Drilled boringB-1 Hand auger boringHA-1

Site PhotographsCARLSON

GEOTECHNICAL

503-601-8250

See Figures 2 and 3 for approximate photograph locations and directions. Photographs were taken at the time of ourfieldwork.

Photograph 1 Photograph 2

FIGURE 4

Photograph 3 Photograph 4


Drafted by: ALS

References:ASTM D2487 Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)ASTM D2488 Standard Practice for Description and Identification of Soils (Visual-Manual Procedure)Terzaghi, K., and Peck, R.B., 1948, Soil Mechanics in Engineering Practice, John Wiley & Sons.

Classification of Terms and ContentNAME: Group Name and Symbol

Relative Density or ConsistencyColorMoisture ContentPlasticityOther ConstituentsOther: Grain Shape, Approximate GradationOrganics, Cement, Structure, Odor, etc.Geologic Name or Formation

Grain Size<#200 (0.075 mm)

FineMediumCoarseFineCoarse

3 to 12 inchesBoulders

Coarse-Grained (Granular) SoilsRelative Density

SPTN60-Value Density

SPTN60-Value

Torvane tsfShear Strength

0.13 - 0.25

>2.00

0.25 - 0.500.50 - 1.001.00 - 2.00

<0.13

Pocket Pen tsfUnconfined

0.25 - 0.50

>4.00

0.50 - 1.001.00 - 2.002.00 - 4.00

<0.25

Consistency

Soft

Hard

Medium StiffStiff

Very Stiff

Very Soft

Manual Penetration Test

Thumb penetrates about 1 inch

Difficult to indent by thumbnail

Thumb penetrates about ¼ inchThumb penetrates less than ¼ inch

Readily indented by thumbnail

Thumb penetrates more than 1 inch2 - 4

>30

Moisture Content

Stratified: Alternating layers of material or color >6 mm thick

Plasticity Dry Strength Dilatancy Toughness

Visual-Manual Classification

CoarseGrained

Soils:More than

50% retainedon No. 200

sieve

Fine-GrainedSoils:

50% or morePasses No.200 Sieve

Gravels: 50% or moreretained onthe No. 4 sieve

Sands: More than50% passing theNo. 4 sieve

Silt and ClaysLow Plasticity Fines

Silt and ClaysHigh Plasticity Fines

CleanGravelsGravelswith FinesCleanSandsSandswith Fines

Highly Organic Soils

GW Well-graded gravels and gravel/sand mixtures, little or no finesGP Poorly-graded gravels and gravel/sand mixtures, little or no finesGM Silty gravels, gravel/sand/silt mixturesGC Clayey gravels, gravel/sand/clay mixturesSW Well-graded sands and gravelly sands, little or no finesSP Poorly-graded sands and gravelly sands, little or no finesSM Silty sands, sand/silt mixturesSC Clayey sands, sand/clay mixturesML Inorganic silts, rock flour, clayey siltsCL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, lean claysOL Organic soil of low plasticityMH Inorganic silts, clayey siltsCH Inorganic clays of high plasticity, fat claysOH Organic soil of medium to high plasticityPT Peat, muck, and other highly organic soils

4 - 88 - 15

15 - 30

<2

#200 - #40 (0.425 mm)#40 - #10 (2 mm)#10 - #4 (4.75)

Sand

> 12 inches

Gravel #4 - 0.75 inch0.75 inch - 3 inches

Cobbles

Fines

0 - 4 Very Loose4 - 10 Loose

10 - 30 Medium Dense30 - 50 Dense

>50 Very Dense

Major Divisions GroupSymbols Typical Names

Structure

Homogeneous: Same color and appearance throughoutLenses: Has small pockets of different soils, note thickness

Blocky: Cohesive soil that can be broken down into small angular lumpswhich resist further breakdown

Slickensided: Striated, polished, or glossy fracture planesFissured: Breaks along definite fracture planesLaminated: Alternating layers < 6 mm thick

MLCLMHCH

Non to LowLow to MediumMedium to HighMedium to High

Non to LowMedium to HighLow to Medium

High to Very High

Slow to RapidNone to SlowNone to Slow

None

Low, can’t rollMedium

Low to MediumHigh

Wet: Visible free water, likely from below water tableMoist: Leaves moisture on handDry: Absence of moisture, dusty, dry to the touch

Soil ClassificationU.S. Standard Sieve

Fine-Grained (Cohesive) Soils

Minor ConstituentsPercent

by Volume Descriptor Example

0 - 5%

5 - 15%

15 - 49%

“Trace” as part of soil description

“With” as part of group name

Modifier to group name

“trace silt”

“SILT WITH SAND”

“SILTY SAND”

Minor ConstituentsPercent

by Volume Descriptor Example

0 - 5% “Trace” as part of soil description

15 - 30% “With” as part of group name5 - 15% “Some” as part of soil description

30 - 49% Modifier to group name

“trace fine-grained sand”

“SILT WITH SAND”“some fine-grained sand”

“SANDY SILT”

CARLSON

GEOTECHNICAL

503-601-8250

FIGURE 5ODVA LEBANON PARKING LOT EXPANSION - LEBANON, OREGONProject Number G1804853

0 25 50

TEST RESULTSStandard Penetration Test, Blows per Foot

GROU

NDW

ATER

Project Number: G1804853Drilled by: Western States Soil Conservation of Hubbard, OregonDrill Rig / Method: CME 55 Track-Mounted Rig / Hollow-Stem Auger with Automatic SPT Hammer

EXPLORATORY BORING LOG B-

ASTM

D248

8

SOIL DESCRIPTION

SAMP

LETY

PE

Figure:

SH-1 Thin Walled TubeSample (ASTM D1587)

SPT-1 Split-SpoonSample (ASTM D1586)

Notes:1. Soil interfaces and descriptions are interpretive and actual changes and transitions may be gradual.2. Water level is for date shown and may vary with the time of year.3. Soil classifications are determined by ASTM D2488 (visual-manual method).

Water Level

SAMP

LENU

MBER

Date Drilled: 05/18/18Logged By: BMWSurface Elevation:

ODVA LEBANON PARKING LOT EXPANSION - LEBANON, OREGON

SPT

DATA

Moisture Content in PercentPercent passing the U.S. Standard No. 200Sieve.

Liquid Limit (LL) in Percent.Plastic Limit (PL) in Percent.

0 25 50

Laboratory Testing

Organic Content in Percent.Carlson Geotechnical7185 SW Sandburg #200

Tigard, Oregon 97223

CARLSON

GEOTECHNICAL

503-601-8250

Legend

Ground water seepage orperched water

DEPT

H(F

EET)

MCAL-1 Mod. CaliforniaSplit-Spoon Sample (ASTM D1586)

1

336.5 Feet

5

10

15

20

25

30

35

0

SPT-12½

7½

12½

17½

22½

27½

32½

SPT-2

SPT-3

2/1/1

9/10/10

6/16/15

20

29

6

ORGANIC SOIL. Brown, moist, rooted, approx. 6" thick.

LEAN CLAY. Soft, brown, moist, medium plasticity

OL

NOTES:1. Boring terminated at a depth of about 9 feet below

ground surface (bgs).2. Boring was backfilled with granular bentonite.3. Groundwater was encountered at a depth of about 4

feet bgs.

2

31

CL

POORLY GRADED GRAVEL with clay. Medium dense,dark gray/brown, wet, rounded, with coarse sand.

GP-GC

0 25 50


GROU

NDW

ATER



ASTM

D248

8

SOIL DESCRIPTION

SAMP

LETY

PE

Figure:




Water Level

SAMP

LENU

MBER



SPT

DATA



0 25 50

Laboratory Testing



CARLSON

GEOTECHNICAL

503-601-8250

Legend


DEPT

H(F

EET)


2

7

336.5 Feet

5

10

15

20

25

0

SPT-12½

7½

12½

17½

22½

SPT-2

30

35

27½

32½

2/1/2

3/6/7 13

39


LEAN CLAY. Soft to medium stiff, brown, moist, mediumplasticity.

OL

NOTES:1. Boring terminated at a depth of about 6½ feet below


feet bgs.

3

CL


GP-GC

18

0 25 50


GROU

NDW

ATER



ASTM

D248

8

SOIL DESCRIPTION

SAMP

LETY

PE

Figure:




Water Level

SAMP

LENU

MBER



SPT

DATA



0 25 50

Laboratory Testing



CARLSON

GEOTECHNICAL

503-601-8250

Legend


DEPT

H(F

EET)


3

8

337.5 Feet

5

10

15

20

25

30

35

0

SPT-12½

7½

12½

17½

22½

27½

32½

SPT-2

SPT-3

SPT-4

MCAL-5

2/1/1

10/24/27

14/20/18

17/17/23

32/57for 6"

38

51

3

SPT-6

35

7/13/53

40

50+

66

13

14


LEAN CLAY. Soft, brown with light gray mottling, moist,medium plasticity.

OL



feet bgs.

CL

POORLY GRADED GRAVEL with clay. Dense to verydense, dark gray/brown, wet, rounded, with coarse sand.

GP-GC

0 25 50


GROU

NDW

ATER



ASTM

D248

8

SOIL DESCRIPTION

SAMP

LETY

PE

Figure:




Water Level

SAMP

LENU

MBER



SPT

DATA



0 25 50

Laboratory Testing



CARLSON

GEOTECHNICAL

503-601-8250

Legend


DEPT

H(F

EET)


4

9

338 Feet

5

10

15

20

25

30

35

0

SPT-12½

7½

12½

17½

22½

27½

32½

SPT-2

2/3/2

6/15/16

5

31

20


LEAN CLAY. Medium stiff, brown, moist, mediumplasticity, with trace rounded fine gravel.

OL



feet bgs.

CL


GP-GC

0 25 50


GROU

NDW

ATER



ASTM

D248

8

SOIL DESCRIPTION

SAMP

LETY

PE

Figure:




Water Level

SAMP

LENU

MBER



SPT

DATA



0 25 50

Laboratory Testing



CARLSON

GEOTECHNICAL

503-601-8250

Legend


DEPT

H(F

EET)


5

10

15

20

25

30

35

0

SPT-22½

7½

12½

17½

22½

27½

32½

SPT-3

SPT-4

SPT-5

1/2/2

1/2/2

15/18/17

13/14/27

41

5

10

Mud Rotary with Automatic Hammer 338 Feet

344

6

5126

SPT-1 4/3/3

4

35


LEAN TO FAT CLAY. Medium stiff, brown, moist,medium plasticity, with trace very fine roots.

OL



feet bgs.

CL-CH


GP-GC

No roots below about 2½ feet bgs.

Uneven drilling (chatter) below about 6½ feet bgs.

0 25 50


GROU

NDW

ATER



ASTM

D248

8

SOIL DESCRIPTION

SAMP

LETY

PE

Figure:




Water Level

SAMP

LENU

MBER



SPT

DATA



0 25 50

Laboratory Testing



CARLSON

GEOTECHNICAL

503-601-8250

Legend


DEPT

H(F

EET)


5

10

15

20

25

0 SPT-1

2½

7½

12½

17½

22½

SH-2

SPT-3

SPT-4

SPT-5

2/2/2

0/0/0

0/1/15

15/21/24

16

4

SPT-6

36

9/23/25

45

48


LEAN CLAY. Soft, brown with light gray mottling, moist,medium plasticity.

OL

NOTES:1. Boring terminated at a depth of about 14 feet below


feet bgs.

CL


GP-GC

Very soft below about 5 feet bgs.4726

14

SH 2: Dry unit weight = 80 pcf.30

6

11

340 Feet

HAND AUGER BORING LOGODVA LEBANON PARKING LOT EXPANSION - LEBANON, OREGON

Date Advanced: 05/18/18Logged by: BMWChecked by: BMW

Location: See Figure 3Approximate Surface Elevation: 339.5 feetEquipment: Manual 3-inch-diameter hand auger

Job No. G1804853 Log of Hand Auger Boring HA-1 Figure 12

1

2

3

4

5

6

7

8

9

10

11

13

14

15

16

17

12

Material Description

Carlson Geotechnical - 7185 SW Sandburg, #200 - Tigard, Oregon 97223

De

pth

(ft)

Sa

mp

leN

um

be

r

Sa

mp

leT

yp

e

Mo

istu

reC

on

ten

t%

Co

rre

late

dN

’va

lue

sfr

om

WD

CP

So

ilC

lass.

pe

rA

ST

MD

24

88

Gro

un

dw

ate

r

CARLSON

GEOTECHNICAL

503-601-8250

Laboratory Testing

P2

00

Sie

ve

%

Org

an

icC

on

ten

t%

Liq

uid

Lim

it%

Pla

stic

Lim

it%

Pla

sticity

Ind

ex

%

Atterberg limits

NOTES:1. Hand auger boring terminated at a depth of about 8¼

feet below ground surface (bgs) due to refusal ofequipment on gravel.

2. Hand auger boring was loosely backfilled withcuttings upon completion.

3. Soil consistency estimated based on effort requiredto advance hand auger into subsurface.

PEAT FILL. Brown, moist, approx. 2 inches. (Barkdust)PTFILL

LEAN CLAY. Medium stiff, brown, moist, mediumplasticity.

CL

Soft to medium stiff below about 2 feet bgs.

Very soft to soft below about 4½ feet bgs.

Sandy below about 7 feet bgs. Minor caving observedbelow this depth.

Wet below about 5½ feet bgs.

GB-1

GB-2

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