23230205 - Geotechnical Evaluation Report.pdf

AA/EOE

Braun Intertec Corporation 1901 16th Avenue SW, Suite 2 Cedar Rapids, IA 52404

Phone: 319.365.0961 Web: braunintertec.com

August 9, 2022 Project B2204326

Mr. Justin H. Campbell, PE

Shive-Hattery, Inc.

222 Third Avenue SE, Suite 300

Cedar Rapids, IA 52401

Re: Geotechnical Evaluation

Bluff Boulevard Reconstruction

Between College Avenue and 7th Avenue North

Clinton, Iowa

Dear Mr. Campbell:

We are pleased to present this Geotechnical Evaluation Report for the proposed Bluff Boulevard reconstruction project in Clinton, Iowa.

Thank you for making Braun Intertec your geotechnical consultant for this project. If you have questions about this report, or if there are other services that we can provide in support of our work to date, please contact Holly Haywood at 816.807.8212 or hhaywood@braunintertec.com or Tim Wiles at 319.375.5801 or twiles@braunintertec.com.

Sincerely, BRAUN INTERTEC CORPORATION

Holly Haywood Project Consultant

Timothy T. Wiles, PE Principal Engineer

Table of Contents

Description Page

A. Introduction A.1. Project Description A.2. Existing Site Conditions and Proposed Site Layout A.3. Purpose A.4. Background Information and Reference Documents A.5. Scope of Services

B. Results B.1. Geologic Overview B.2. Coring Results B.3. Boring Results B.4. Laboratory Test Results B.5. Groundwater

C. Recommendations C.1. Design and Construction Discussion C.2. Site Grading and Subgrade Preparation

C.2.a. Subgrade Preparation C.2.b. Pavement Subgrade Preparation C.2.c. Engineered Fill Materials and Compaction C.2.d. Pavement Section Recommendations C.2.e. Subdrain Design C.2.f. Performance and Maintenance

C.3. Utilities C.3.a. Subgrade Stabilization C.3.b. Corrosion Potential

C.4. Equipment Support D. Procedures

D.1. Coring and Penetration Test Borings D.2. Exploration Logs

D.2.a. Log of Boring Sheets D.2.b. Geologic Origins

D.3. Material Classification and Testing D.3.a. Visual and Manual Classification D.3.b. Laboratory Testing

E. Qualifications E.1. Variations in Subsurface Conditions

E.1.a. Material Strata E.1.b. Groundwater Levels

E.2. Continuity of Professional Responsibility E.2.a. Plan Review E.2.b. Construction Observations and Testing

E.3. Use of Report E.4. Standard of Care

Appendix: Figure A-1: Soil Boring Location Plan (All); Figures A-2 to A-4 Soil Boring Location Plan (West, Center and East); Figure A-5 to A-7: Subsurface Profiles; Core Photo Log; Log of Borings Sheets; Sieve Analysis Test Results;

California Bearing Ratio Test Results; Standard Proctor Test Results; Descriptive Terminology of Soil

A. Introduction

A.1. Project Description

This Geotechnical Evaluation Report addresses the proposed design and reconstruction of approximately

2.1 miles of Bluff Boulevard from College Avenue to 7th Avenue North and 500 feet of 7th Avenue North in

Clinton, Iowa. The project includes widening Bluff Boulevard in some areas to a three-lane road with middle turning lane. Additionally, we understand two roundabouts are planned along the planned Bluff

Boulevard reconstruction. The general outline of the proposed road alignment is shown in Figures A-2 through A-4 in the attachments. Table 1 provides project details.

Table 1. Project Description

Aspect Description

Nature of construction PCC (Portland Cement Concrete) or HMA (Hot Mix Asphalt)

Estimated Traffic Volume Unknown

Site grading Less than about 5 feet (Provided)

A.2. Existing Site Conditions and Proposed Site Layout

Currently, the roadway segment exists as a two- to four-lane, approximately 2.1 miles of HMA pavement along Bluff Boulevard and 500 feet of HMA along 7th Avenue North. The project area begins approximately 150 feet west of College Avenue to approximately 180 feet west of North 5th Street along

7th Avenue North. The site is bordered by residential houses and various commercial properties and associated pavements.

Current grades range from approximate elevations of 595 to 616 feet. Generally, the profile of the site is rolling hills with about 10 to 12 feet of grade change. However, between 2nd Avenue and 4th Avenue along Bluff Boulevard the profile dips lower than the remaining portion of the road with up to 20 feet of elevation difference in that area. A detailed history of construction and maintenance of this roadway was not provided to us.

A.3. Purpose

The purpose of this geotechnical evaluation is to provide information about the pavement and subsurface geologic conditions at selected boring locations, evaluate their impact on the project, and provide geotechnical recommendations for the design and reconstruction of Bluff Boulevard.

Project B2204326 August 9, 2022

A.4. Background Information and Reference Documents

We reviewed the following information:

▪ Drive to Prosperity - Bluff Boulevard, Concept Exhibit dated July 8, 2022, provided by Shive-

Hattery, Inc.

▪ Email and phone communications with Shive-Hattery, Inc.

▪ Publicly available sources of information

We have described our understanding of the proposed construction and site to the extent others reported it to us. Depending on the extent of available information, we may have made assumptions based on our experience with similar projects. If we have not correctly recorded or interpreted the project details, the project team should notify us. New or changed information could require additional evaluation, analyses, and/or recommendations.

A.5. Scope of Services

We performed our scope of services for the project in accordance with our Proposal for a Geotechnical

Evaluation, dated March 24, 2022, and in accordance with our Master of Services Agreement (MSA) dated November 7, 2018. The following list describes the geotechnical tasks completed in accordance with our authorized scope of services.

▪ Reviewed the background information and reference documents previously cited.

▪ Staked and cleared the exploration location of underground utilities. The Soil Boring Location

Plan included in the Appendix shows the approximate locations of the borings.

▪ Performed 24 pavement cores follow by standard penetration test (SPT) borings and two SPT borings that did not include pavement cores, denoted as B-1 through B-26, within the proposed pavement improvement and new pavement area to nominal depths of 1.5 to 15 feet below grade across the site.

▪ Performed laboratory testing on selected samples to aid in soil classification and engineering analysis.

▪ Prepared this report containing a boring location plan, logs of soil borings, a summary of the soils encountered, results of laboratory tests, and recommendations for pavement subgrade preparation and the design and reconstruction of pavements.

Our scope of services did not include environmental services or testing and our geotechnical personnel performing this evaluation are not trained to provide environmental services or testing. We can provide environmental services or testing at your request.

B. Results

B.1. Geologic Overview

We based the geologic origins used in this report on the soil types, in-situ and laboratory testing, and available common knowledge of the geological history of the site. Because of the complex depositional history, geologic origins can be difficult to ascertain. We did not perform a detailed investigation of the geologic history for the site.

B.2. Coring Results

Table 2 on the following page provides a summary of the pavement cores including pavement type and thickness.

B.3. Boring Results

Table 3 on page 5 of this report provides a summary of the soil boring results; in the general order we encountered the strata. We indicate the depths as measured from existing grade. Please refer to the Log of Boring sheets in the Appendix for additional details. The Descriptive Terminology sheets in the

Appendix include definitions of abbreviations used in Table 3.

B.4. Laboratory Test Results

The boring logs show the results of laboratory testing we performed, next to the tested sample depth.

Additionally, the California Bearing Ratio (CBR), Standard Proctor, and sieve analysis test reports are included in the Appendix.

The moisture content of the sandy soils ranged from 6 to 17 percent. The moisture contents of the native clayey soils ranged from 14 to 27 percent. Two unconfined compression tests were performed on Shelby tube samples consisting of lean clay. The resulting strength ranged from 0.7 tsf to 2.0 tsf.

Table 2. Pavement Core Summary

Boring Location

HMA Thickness (inches)

PCC Thickness (inches)

Brick Thickness (inches) Notes

B-1 NA 9.5 NA Subbase: Approx. 5 inches of gravel

B-2 NA 6 NA Subbase: Approx. 3 inches of clayey sand

B-3 NA 8 NA Subbase: Approx. 12 inches of clayey sand

B-4 NA 8 NA Subbase: Approx. 3 inches of clayey sand

B-5 NA 8 NA Subbase: Approx. 4 inches of sandy clay

B-7 4 NA 3.5 Subbase: Approx. 3 inches of clayey sand

B-8 5 NA 3.5 Subbase: Approx. 3 inches of sand

B-9 5.5 NA 3.5 Subbase: Approx. 4 inches of clayey sand

B-10 4.25 NA 3.5 Subbase: Approx. 2 inches of clayey sand

B-11 4 NA 3.5 Subbase: Approx. 3 inches of clayey sand

B-12 3.5 8 NA No apparent subbase

B-13 4.5 NA NA Subbase: Approx. 3 inches of gravel

B-14 3.25 7 NA No apparent subbase

B-15 9 6.5 NA No apparent subbase

B-16 3.5 7.5 NA Subbase: Approx. 4 inches of clayey sand

B-17 9 NA NA No apparent subbase

B-18 8 NA NA Subbase: Approx. 2 inches of clayey sand

B-19 5 NA NA No apparent subbase

B-20 7.5 NA NA No apparent subbase

B-21 7 NA NA No apparent subbase

B-22 8.5 NA NA No apparent subbase

B-23 8.5 NA NA No apparent subbase

B-25 9.5 NA NA No apparent subbase

B-26 7.5 NA NA No apparent subbase

Our mechanical analyses indicated that the native soils contained a wide array of compositions including clay, silt, silty sand, clayey sand, and sand with gravel. The boring logs show the material type based on the sieve analysis. The liquid limit determined for the clay or silt soils ranged from 22 to 38 and plasticity index of 4 to 21. These results indicate that the fine-grained portion of the fill soils tested classify as lean clay or low plasticity silt. Our analysis included performing CBR and Standard Proctor tests on the proposed subgrade soils. The results of our CBR tests ranged from 2.2 to 8.9 with an average of 5.8 and included silty sand and lean clay soil types. The results of the Standard Proctor test provided maximum dry densities of 112 pcf to 123 pcf and optimum moisture contents of 10.3% to 15.3%.

Table 3. Subsurface Profile Summary

Strata

Soil Type -

ASTM

Classification

Range of Penetration Resistances

(Blows Per Foot) Commentary and Details

Pavement section

▪ Present at all borings, excluding B-6 and B-24 to depths of approximately 4.5 to 15.5 inches.

▪ PCC pavement in B-1 through B-5

▪ HMA overlying PCC or brick in B-7 through B-

12, B-14, B-15, and B-16; and HMA only in B- 13, B-17 through B-26 (excluding B-24).

Pavement Subbase

CL, SC, SP, GC,

GP

▪ Where observed the pavement subbase consisted generally of sandy soils with some clay and gravel

▪ Thickness ranges from 2 to 12 inches

Existing Fill CL 5 to 13

▪ Present in B-1 through B-5, B-7, B-11, B-13, B- 16, B-18, and B-22 below pavement

▪ Encountered to depths of 0.7 to 5 feet

▪ Generally sandy and may contain gravel

Loess and Eolian Deposits

CL, SM, SC, SP 4 to 14

▪ Present in B-1, B-3 through B-7, B-11, and B-22 below existing fill, topsoil, or pavement

▪ Loess soils are generally medium to stiff CL

▪ Eolian soils generally loose, fine-grained sand

▪ Encountered to a depth of 3 to 9 feet and until termination depth in B-4.

Glacial Deposits

CL

(Till) 5 to 10

▪ Present in borings B-1, B-2, B-3, B-11, B-20, B- 22, and B-25 below fill, loess/eolian soil, or pavement.

▪ Typically sandy, with trace gravel

▪ Generally medium to stiff

▪ Encountered to depths of 3 to 13 feet

Residuum

CL, CH, SM,

SP, GP

4 to 45

▪ Present in all borings excluding B-1, B-4, B-11 through B-13, B-16, B-18, B-20, B-21, B-23 below pavement, fill, loess/eolian deposits, or glacial till

▪ Typically gravel or with gravel and sand

▪ Medium to stiff clays or medium dense to dense sands or gravels

▪ Encountered to depths of 2 to 15 feet typically above limestone bedrock.

Bedrock Limestone 50 to 50 blows per 0 inches

▪ Present in all borings, except B-3, B-4, and B-7

▪ Encountered at depths of 0.6 to 13 feet

▪ Generally, highly weathered and hard

B.5. Groundwater

Groundwater was observed in Borings B-5 and B-7 at depths of 13½ and 14½ feet, respectively, but was not observed in the other borings. The attached Log of Boring sheets also include this information and additional details. There will be seasonal and annual fluctuations of groundwater as well as fluctuations based on periods of heavy or prolonged precipitation and the level of nearby bodies of water.

C. Recommendations

C.1. Design and Construction Discussion

Based on the results of our field exploration, laboratory testing, and our understanding of the project, it is our opinion that the site is suitable for the proposed construction with the following geotechnical design and construction considerations.

▪ A detailed grading plan or profile was not provided at this time; however, we assume grade changes will be less than about 5 feet. Settlement due to the weight of new fill less than 5 feet thick will not cause significant settlement in soils similar to those encountered by our borings.

▪ Pavement types and thickness vary across the project site with a general thickness of 4½ to 15½ inches below existing surface as shown in Table 2. We understand that it is planned to remove all pavement materials as part of the reconstruction. We agree that all pavement materials

(cement concrete, HMA and brick) should be removed in their entirety.

▪ While we expect the existing fill was placed with some compactive effort, we were not provided records regarding observation of the fill placement or field density testing. Typically, untested fill can contain zones of soft of loose material that borings may or may not encounter resulting in a higher-than-normal risk of adverse settlement. However, the condition of the previous pavement may be an indicator of the performance of this existing fill. Lower portions of the existing fill may be left in place if there is a minimum of 2 feet of new, compacted fill below subgrade level to provide uniformity. If the untested existing fill is left in place, the owner should be willing to accept the risk settlement due to any soft or loose zones that were not detected during proofrolling.

▪ Based on our general understanding of the proposed cut and fill, it appears that excavation of limestone bedrock could be required along portions of the proposed road alignment to achieve design grades. Shallow limestone bedrock was typically encountered within 2 feet of existing grade in portions of the north half of the project. See Figure A-5 through A-7 for locations of shallow bedrock. We recommend that bedrock be excavated to a depth of 2 feet below subgrade level to allow for a uniform layer of new compacted fill. In general, highly weathered limestone above refusal depths shown on our boring logs can be removed with conventional earthmoving equipment (i.e., backhoes and bulldozers). Weathered limestone below refusal depths can often require single-tooth rippers mounted on bulldozers or pneumatic breakers. The contractor should be prepared to remove more resistant rock.

▪ We anticipate the pavement layers (pavement and aggregate base) will be placed on 2 feet of new compacted fill extending to existing soils that have been proofrolled and corrected as necessary. In general, these soils should provide adequate support under the assumed traffic loads.

▪ The lean clays encountered at this site can become unstable from excessive moisture and earthwork construction activities. Disturbance of these soils may cause areas that were previously suitable for pavement support to become unstable, requiring additional moisture conditioning and compaction, chemical stabilization, or subcutting and replacement. To the extent possible the site should be maintained in a manner to promote sheet drainage and minimize the ponding of water during construction.

▪ We observed groundwater a depth of 13½ to 14½ feet below existing grade in two borings, but did not encounter groundwater in any of the other borings. We anticipate excavations to depths less than five feet will not likely encounter groundwater. However, we recommend the contractor control surface water from entering excavations. The design team should be aware that zones of perched water could develop at varying elevations and locations depending upon recent precipitation. We anticipate that sumps and pumps within the excavation will be adequate to control groundwater.

▪ Onsite soils free of organic matter can be reused as engineered fill. Proper moisture conditioning of the clayey soils will be required prior to compaction.

C.2. Site Grading and Subgrade Preparation

C.2.a. Subgrade Preparation

We recommend removing the existing pavement section and unsuitable materials from below the proposed pavement area. Due to the variability in strength and consistency of the existing subgrade soils, we recommend placing a 2-foot layer of new compacted fill below the proposed subgrade elevation. We define unsuitable materials as frozen materials, organic soils, existing structures, existing utilities, vegetation, and soft or loose soils. A geotechnical engineer or experienced soil technician should observe the excavations to make the necessary field judgement regarding the suitability of the exposed soil in the excavation bottoms.

C.2.b. Pavement Subgrade Preparation

We recommend the following steps for pavement subgrade preparation. Note that project planning may need to require additional subcuts to limit frost heave.

1. Strip unsuitable soils consisting of topsoil, organic soils, vegetation, existing structures, and pavements from the area. Excavate to a depth of 2 feet below the proposed subgrade level.

2. Proofroll the excavation bottom with a fully loaded tandem-axle truck prior to placing new fill. Have a geotechnical representative observe the proofroll and the excavated subgrade to evaluate if additional subgrade improvements are necessary. The contractor should correct areas that display excessive yielding or rutting during the proofroll, as determined by the geotechnical representative. Possible options for subgrade correction include moisture conditioning and recompaction, subcutting and replacement with soil or crushed aggregate, chemical stabilization, and/or geotextiles

3. Slope subgrade soils to areas of sand or drain tile to allow the removal of any accumulating water.

4. Place engineered fill to grade and compact in accordance with this report.

C.2.c. Engineered Fill Materials and Compaction

Table 4 below contains our recommendations for engineered fill materials. More select soils comprised of coarse sands with < 5% passing #200 sieve may be needed to accommodate work occurring in periods of wet or freezing weather.

Table 4. Engineered Fill Materials

Locations To Be Used

Engineered Fill

Classification

Possible Soil Type

Descriptions Gradation

Additional

Requirements

Pavements Pavement fill GP, SP, SM, SC, CL 100% passing 3-inch sieve

< 2% OC

PI < 15%

Below landscaped areas, where subsidence is not a concern

Non-structural fill 100% passing 6-inch sieve < 10% OC

We recommend spreading engineered fill in loose lifts of approximately 8 to 10 inches thick. We recommend compacting engineered fill in accordance with the criteria presented below in Table 5. The project documents should specify relative compaction of engineered fill, based on the structure located above the engineered fill, and vertical proximity to that structure.

Table 5. Compaction Recommendations Summary

Reference

Relative Compaction, %

(ASTM D698 – Standard

Proctor)

Moisture Content Variance from Optimum, %-points

< 12% Passing #200 Sieve

(typically SP, SP-SM)

> 12% Passing #200 Sieve

(typically CL, SC, ML, SM)

Within 2 feet of pavement subgrade 98 ±3 -1 to +3

More than 2 feet below pavement subgrade 95 ±3 ±3

Below landscaped surfaces 90 ±5 ±4

The project documents should not allow the contractor to use frozen material as engineered fill or to place engineered fill on frozen material. Frost should not penetrate under foundations during construction. We recommend performing density tests in engineered fill to evaluate if the contractors are effectively compacting the soil and meeting project requirements.

C.2.d. Pavement Section Recommendations

Our scope of services for this project includes laboratory testing on subgrade soils to determine a CBR or modulus value for pavement design. Based on the results of our tests, we recommend pavement design use a CBR of 5 and a modulus of subgrade reaction (k) of 100 pci for the pavement design. The design of pavement and subbase thicknesses should consider maintenance, such as seal coating and crack sealing and other factors such as variations in weather and traffic conditions.

We recommend designing the pavement sections based on the anticipated traffic loading, road type, and anticipated subgrade support in accordance with Iowa SUDAS Section 5F-1. We understand the road type is a minor arterial road; however, we do not know the anticipated traffic loading or growth rate. We assume the road will be designed for 10,000,000 ESALs or less. As per Table 5F-1.15 in Iowa SUDA, the minimum rigid pavement thickness for an arterial road with 10,000,000 ESALs is 9 inches over 12 inches of granular subbase. We recommend specifying a granular subbase beneath the proposed pavement section consisting of a minimum 12-inch thickness, in accordance with Iowa SUDAS Section 5F-1. This layer should meet the material and compaction specifications of “Section 4121 Granular Subbase” as stated in the Iowa Department of Transportation Standard Specifications. If traffic loading is expected to be greater than 10,000,000 ESALs additional pavement is required.

C.2.e. Subdrain Design

We recommend installing longitudinal subdrains below the granular base, along the edge of the pavements where practical, due to the presence of frost-susceptible soils in the proposed construction areas. Longitudinal subdrain should drain the permeable base to decrease the potential for frost heave, increase the stability of the roadbed and prolong pavement life. The contractor should install subdrains to extend to a depth of at least 2 feet below subgrade, be hydraulically connected to the granular base, and discharge to a reliable outlet in accordance with Iowa SUDAS Section 6G-1.

We recommend the subdrain consist of a trench lined with filter fabric and a drainage pipe surrounded by granular backfill. The backfill should be free draining and meet the requirements of IDOT Specification

4131 (Gradation 29). An alternate subdrain design could include the filter fabric wrapped around the drainage pipe instead of between the backfill and native soils. In this case, we recommend using granular backfill that is graded to prevent the intrusion of fines. We also recommend using clean sand as backfill materials around the fabric-wrapped pipe.

C.2.f. Performance and Maintenance

Many conditions affect the overall performance of the pavements. Some of these conditions include the environment, loading conditions, and the level of ongoing maintenance. We recommend developing a regular maintenance plan for filling cracks in pavements to lessen the potential impacts for cold weather distress due to frost heave or warm weather distress due to wetting and softening of the subgrade.

C.3. Utilities

C.3.a. Subgrade Stabilization

Earthwork activities associated with utility installations located inside the building area should adhere to the recommendations in this report. For exterior utilities, the soils at typical invert elevations will be suitable for utility support. However, if construction encounters conditions such as debris or organic soils at invert grades, these soils may require subcutting and replacement with sand or crushed rock for pipe support. Project design should not place utilities within the 1H:1V oversizing of foundations.

C.3.b. Corrosion Potential

Based on our experience, the soils encountered by the borings are moderately corrosive to metallic conduits, but only marginally corrosive to concrete. We recommend specifying non-corrosive materials or providing corrosion protection, unless project planning chooses to perform additional tests to demonstrate the soils are not corrosive.

C.4. Equipment Support

The recommendations included in the report may not be applicable to equipment used for the construction and maintenance of this project. We recommend evaluating subgrade conditions in areas of shoring, scaffolding, cranes, pumps, lifts, and other construction equipment prior to mobilization to determine if the exposed materials are suitable for equipment support or require some form of subgrade improvement. We also recommend project planning consider the effect that loads applied by such equipment may have on structures they bear on or surcharge – including pavements, buried utilities, below-grade walls, etc. We can assist you in this evaluation.

D. Procedures

D.1. Coring and Penetration Test Borings

We drilled the cores with a coring fill rig equipped with a 6-inch pavement core bit. We then drilled the penetration test borings through the core holes with a track-mounted core and auger drill equipped with hollow-stem auger. We performed the borings in general accordance with ASTM D6151 taking penetration test samples at 2½- or 5-foot intervals in general accordance with ASTM D1586. We collected thin-walled tube samples in general accordance with ASTM D1587 at selected depths. The boring logs show the actual sample intervals and corresponding depths.

D.2. Exploration Logs

D.2.a. Log of Boring Sheets

The Appendix includes Log of Boring sheets for our penetration test borings. The logs identify and describe the penetrated geologic materials and present the results of penetration resistance and other in-situ tests performed. The logs also present the results of laboratory tests performed on soil samples and groundwater measurements.

We inferred strata boundaries from changes in the soil samples and the auger cuttings. Because we did not perform continuous sampling, the strata boundary depths are only approximate. The boundary depths likely vary away from the boring locations, and the boundaries themselves may occur as gradual rather than abrupt transitions.

D.2.b. Geologic Origins

We assigned geologic origins to the materials shown on the logs and referenced within this report, based on: (1) a review of the background information and reference documents cited above, (2) visual classification of the various geologic material samples retrieved during the course of our subsurface exploration, (3) penetration resistance testing performed for the project, (4) laboratory test results, and

(5) available common knowledge of the geologic processes and environments that have impacted the site and surrounding area in the past.

D.3. Material Classification and Testing

D.3.a. Visual and Manual Classification

We visually and manually classified the geologic materials encountered based on ASTM D2488. When we performed laboratory classification tests, we used the results to classify the geologic materials in accordance with ASTM D2487. The Appendix includes a chart explaining the classification system.

D.3.b. Laboratory Testing

The exploration logs in the Appendix note the results of the laboratory tests performed on geologic material samples. We performed the tests in general accordance with ASTM or AASHTO procedures.

E. Qualifications

E.1. Variations in Subsurface Conditions

E.1.a. Material Strata

We developed our evaluation, analyses, and recommendations from a limited amount of site and subsurface information. It is not standard engineering practice to retrieve material samples from exploration locations continuously with depth. Therefore, we must infer strata boundaries and thicknesses to some extent. Strata boundaries may also be gradual transitions, and project planning should expect the strata to vary in depth, elevation, and thickness, away from the exploration locations.

Variations in subsurface conditions present between exploration locations may not be revealed until performing additional exploration work or starting construction. If future activity for this project reveals any such variations, you should notify us so that we may reevaluate our recommendations. Such variations could increase construction costs, and we recommend including a contingency to accommodate them.

E.1.b. Groundwater Levels

We made groundwater measurements under the conditions reported herein and shown on the exploration logs and interpreted in the text of this report. Note that the observation periods were relatively short, and project planning can expect groundwater levels to fluctuate in response to rainfall, flooding, irrigation, seasonal freezing and thawing, surface drainage modifications and other seasonal and annual factors.

E.2. Continuity of Professional Responsibility

E.2.a. Plan Review

We based this report on a limited amount of information, and we made a number of assumptions to help us develop our recommendations. We should be retained to review the geotechnical aspects of the designs and specifications. This review will allow us to evaluate whether we anticipated the design correctly, if any design changes affect the validity of our recommendations, and if the design and specifications correctly interpret and implement our recommendations.

E.2.b. Construction Observations and Testing

We recommend retaining us to perform the required observations and testing during construction as part of the ongoing geotechnical evaluation. This will allow us to correlate the subsurface conditions exposed during construction with those encountered by the borings and provide professional continuity from the design phase to the construction phase. If we do not perform observations and testing during construction, it becomes the responsibility of others to validate the assumption made during the preparation of this report and to accept the construction-related geotechnical engineer-of-record responsibilities.

E.3. Use of Report

This report is for the exclusive use of the addressed parties. Without written approval, we assume no responsibility to other parties regarding this report. Our evaluation, analyses and recommendations may not be appropriate for other parties or projects.

E.4. Standard of Care

In performing its services, Braun Intertec used that degree of care and skill ordinarily exercised under similar circumstances by reputable members of its profession currently practicing in the same locality.

No warranty, express or implied, is made.

Appendix

M o u n t P leas ant P ark

Rd

M o u n t P lea sant P ark

R d

Lee Ln

Lee Ln

7th Ave7th Ave

Crescent Dr

Crescent Dr

Isa b e lla

C t

Isa b e lla

C t

Beckman Ln

Beckman Ln

Woodlawn Ct

Woodlawn Ct th

A vct

N th A vct N

A lb a n y C t

A lb a n y C t

Caroline Ave

Caroline Ave

N B lu ff

B lv d

N B lu ff

B lv d

East LnEast Ln

S

1t h

S t

S

1t h

S t

C ra b T re e

C t

C ra b T re e

C t

S u rre y C t S u rre y C t

Dubuque C t

Dubuque C t

Bobetta CtBobetta Ct

13th Ave13th Ave

E lm h u rs t

C t

E lm h u rs t

C t

S 9th AveS 9th Ave

Rock Creek Ln

Rock Creek Ln

N th S t N th

S t

A d a m s P l

A d a m s P l

Overlo ok Ln

Overlo ok Ln

8th Ave8th Ave

H eather Ln

H eather Ln

M yr a P l M yr a

P l

S th

S t

S th

S t

Becknan Ln

Becknan Ln

D o u g la s

C t

D o u g la s

C t

O rch a rd

L n

O rch a rd

L n

W h isp e r i ng Pines

W h isp e r i ng Pines

Keith CtKeith Ct

10th Ave10th Ave

L a w n d a le D r L a w n d a le

D r

6th Ave6th Ave

Roc kw ood Ct

Roc kw ood Ct

11th Ave

11th Ave

Locust PlLocust Pl

1st Ave1st Ave

L a w re n ce

S t

L a w re n ce

S t

Carriage Hill Dr

Carriage Hill Dr

H ill cr es t D r H ill cr es t

D r

Sa in t M ich ael Dr

Sa in t M ich ael Dr

Circle Dr ECircle Dr E

10th St10th St

S th

S t

S th

S t

C olleg e A ve

C olleg e A ve

K e n ilw o rth

C t

K e n ilw o rth

C t

M e lro se

C t

M e lro se

C t

S th S t S th

S t

5th Ave5th Ave Florence AveFlorence Ave

G ra ndview Dr

G ra ndview Dr

Rid g e cr e st

D r

Ri d g e cr e st

D r

N th S t N th

S t

6th Ave6th Ave

6th Ave 6th Ave

Li be rty A ve

Li be rty A ve

N th

S t

N th

S t

5th Ave5th Ave

A rg yl e

C t

A rg yl e

C t

F a ye tt e S t F a ye tt e

S t

5th Ave 5th Ave

S th S t S th

S t

N th S t N th

S t

Bria rc liff Ln

Bria rc liff Ln

H ig h vie w D r H ig h vie w

D r

R u th P l R u th

P l

7th Ave7th Ave

N th

S t

N th

S t

IkesP eak R d

IkesP eak R d

S th

S t

S th

S t

S th

S t

S th

S t

Woodlawn AveWoodlawn Ave

Glenwood Pl

Glenwood Pl

T h o rw a ld se n

P l

T h o rw a ld se n

P l

S th S t S th

S t

N th

S t

N th

S t

N th S t N th

S t

S th

S t

S th

S t

S th

S t

S th

S t

S th S t S th

S t

S th S t S th

S t

8th Ave8th Ave

14th Ave14th Ave

12th Ave12th Ave

N th

S t

N th

S t

1st Ave1st Ave

9th Ave9th Ave

2nd Ave2nd Ave

N th

S t

N th

S t

S th

S t

S th

S t

3rd Ave3rd Ave

6th Ave6th Ave

4th Ave4th Ave

S th S t S th

S t

13th Ave13th Ave

S

T H

S T

S

T H

S T

S

T H

S T

S

T H

S T

TERRACE

D

R

TERRACE

D

R

7TH AVE

7TH AVE

R

AVINE

PL

R

AVINE

PL

S

T H

S T

S

T H

S T

S

T

H S

T S

T H

S T

SPR

IN

G D

ALE D

R

SPR

IN

G D

ALE D

R

LI

NCO

LN

B

LV

D

LI

NCO

LN

B

LV

D

N

T H

S T

N

T H

S T

S

T H

S T

S

T H

S T

N

T H

S T

N

T H

S T

8TH AVE8TH AVE

7TH AVE7TH AVE

11TH AVE11TH AVE

2ND AVE2ND AVE

")F14

£¤30

B-1

B-2

B-3

B-4

B-5

B-6

B-7

B-8

B-9

B-10

B-11

B-12

B-13

B-14

B-15 B-16

B-17

B-18

B-19

B-20

B-21

B-22

B-23

B-24

B-25

B-26

13th Ave N

Clin ton Rd

FultonLyons

Clinton

Walle r

R d

Lincoln Way

Camanche

Project Information

Drawing Information

Drawn By:

Drawn Drawn:

Checked By:

Last Modified:o

0 800400

Feet

Figure A-1

Project No:

B2204326

ZS

7/18/2022

HGH

7/18/2022

Soil Boring Location Sketch

FA1

Drawing No:

F :\2

2\

B

6\ G

IS

\B

6.

ap rx

Bluff Boulevard Reconstruction

Between College Avenue and 7th Avenue North

Clinton, Iowa

1" = 800 Feet

!( Approximate Boring Location

Source: Google Earth Imagery

11529 W 79th St Suite 21 Lenexa, KS 66214

913.962.0909 braunintertec.com

M yra P l

M yra P l th S t th

S t

LeeLnLee Ln

Beckman Ln

Beckman Ln

B riarw ood Ln

B riarw ood Ln

Caroline Ave

Caroline Ave

C ra b T re e

C t

C ra b T re e

C t

Dubuque

Dubuque

S u rre y C t S u rre y C t

Dubuque C t

Dubuque C t

W es tw oo d Ln

W es tw oo d Ln

E lm h u rs t

C t

E lm h u rs t

C t

S th

S t

S th

S t

S th

S t

S th

S t

S th

S t

S th

S t

Becknan Ln

Becknan Ln

O rch a rd

L n

O rch a rd

L n

Te rr ac e

D r

Te rr ac e

D r

B luff H eights R d

B luff H eights R d

Rockwood C t

Rockwood C t

11th Ave

11th Ave

S th

S t

S th

S t

Circle Dr ECircle Dr E

10th St10th St

S th

S t

S th

S t

C ollege A ve

C ollege A ve

9th Ave9th Ave

S th

S t

S th

S t

S 15th S t

S 15th S t

7th Ave7th Ave

8th Ave8th Ave

12th Ave12th Ave

14th Ave14th Ave

13th Ave13th Ave

Carolin e

Carolin eA ve A ve

8TH AVE8TH AVE

TERRACE D

R

TERRACE D

R

M A

N U

FA

C

TU

R

IN

G

D R

M A

N U

FA

C

TU

R

IN

G

D R

S

T

H S

T S

T H

S T

11TH AVE11TH AVES

T

H S

T S

T H

S T

S BLUFF BLVD

S BLUFF BLVD

B-1

B-2

B-3

B-4

B-5

B-6

B-7

B-8

B-9

B-10

4th Ave S 2nd Ave S

8th Ave S

N th

S t

2nd Ave S

8th Ave S

15th Ave S

H ar ri son Dr

13th Ave S

10th Ave S

S th

S t

M an uf actu ri ng

D r

Lib ert y A ve

Project Information

Drawing Information

Drawn By:

Drawn Drawn:

Checked By:

Last Modified:o

0 300150

Feet

Figure A-2

Project No:

B2204326

ZS

7/18/2022

HGH

7/18/2022

Soil Boring Location Sketch

- West

FA2

Drawing No:

F :\2

2\

B

6\ G

IS

\B

6.

ap rx

Bluff Boulevard Reconstruction

Between College Avenue and 7th Avenue North

Clinton, Iowa

1" = 300 Feet

!( Approximate Boring Location

Source: Google Earth Imagery

11529 W 79th St Suite 21 Lenexa, KS 66214

Crescent Dr

Crescent Dr

Isa b e lla

C t

Isa b e lla

C t

S

1t h

S t

S

1t h

S t

Woodlawn C t

Woodlawn C t

W es tw oo d Ln

W es tw oo d Ln

E lm h u rs t

C t

E lm h u rs t

C t

Rock Creek Ln

Rock Creek Ln

Florence AveFlorence Ave

H eather Ln

H eather Ln

C u rtis

Cir

C u rtis

Cir

M yr a P l M yr a

P l

S th

S t

S th

S t

3rd Ave3rd Ave

S th S t S th

S t

D o u g la s

C t

D o u g la s

C t M e lro se C t M e lro se C t

Caroline Ave

Caroline Ave

H illc re st

D r

H ill cr es t D r

K e n ilw o rth

C t

K e n ilw o rth

C t

6th Ave6th Ave

4th Ave4th Ave

5th Ave5th Ave

A rg yl e

C t

A rg yl e

C t

W oodlaw n Ave

W oodlaw n Ave

T h o rw a ld se n

P l

T h o rw a ld se n

P l

RAVINE PL

RAVINE PL

S

T H

S T

S

T H

S T

8TH AVE8TH AVE

7TH AVE7TH AVE

S

BLU

FF

BLV

D

S

BLU

FF

BLV

D

B-9

B-10

B-11

B-12

B-13

B-14

B-15

B-16

B-17

1st Ave

4th Ave S

8th Ave S

N th

S t

6th Ave N

2nd Ave S

8th Ave S

M il l C re e k P kw y

Clinton

15th Ave S

H ar ri son Dr

13th Ave S

10th Ave S

S th

S t

M an uf actu ri ng

D r

Lib ert y A ve

Project Information

Drawing Information

Drawn By:

Drawn Drawn:

Checked By:

Last Modified:o

0 250125

Feet

Figure A-3

Project No:

B2204326

ZS

7/18/2022

HGH

7/18/2022

Soil Boring Location Sketch

- Central

FA3

Drawing No:

F :\2

2\

B

6\ G

IS

\B

6.

ap rx

Bluff Boulevard Reconstruction

Between College Avenue and 7th Avenue North

Clinton, Iowa

1" = 250 Feet

!( Approximate Boring Location

Source: Google Earth Imagery

11529 W 79th St Suite 21 Lenexa, KS 66214

MountPleasant P ark

R d

MountPleasant P ark

R d

7th Ave7th Ave

8th Ave 8th Ave st

A ve st

A ve

5th Ave5th Ave th

A vct

N th A vct N th

A ve n u e N

C t th

A ve n u e N

C t

2nd Ave2nd Ave

N B lu ff

B lv d

N B lu ff

B lv d

S th S t S th

S t

N th S t N th

S t

A d a m s P l

A d a m s P l

S th

S t

S th

S t

N 10th S t

N 10th S t

6th Ave6th Ave

Saint M ic hael Dr

Saint M ic hael Dr

4th Ave4th Ave

Locust PlLocust Pl

S th S t S th

S t

N th S t N th

S t

S th S t S th

S t

S th S t S th

S t

2nd Ave2nd Ave

F a ye tt e S t F a ye tt e

S t

6th Ave 6th Ave

N th S t N th

S t

4th Ave4th Ave

5th Ave 5th Ave

Ike s

P eak

R d

Ike s

P eak

R d

4th Ave 4th Ave

3rd Ave 3rd Ave

Glenwood Pl

Glenwood Pl

N th S t N th

S t

1st Ave1st Ave

3rd Ave3rd Ave

RAVINE

PL

RAVINE

PL

7TH AVE

7TH AVE

S

T H

S T

S

T H

S T

2ND AVE2ND AVE

S B

LU

FF B

LV

D

S B

LU

FF B

LV

D

SPR

IN

G D

ALE D

R

SPR

IN

G D

ALE D

R

N

T H

S T

N

T H

S T

N

BLUFF

BLV

D

N

BLUFF

BLV

D

B-17

B-18

B-19

B-20

B-21

B-22

B-23

B-24

B-25

B-26

1st Ave

4th Ave S

8th Ave S

N th

S t

6th Ave N

R iv e rv ie w

D r

2nd Ave S

8th Ave S

13th Ave N

N n d

S t

Clinton

10th Ave S

Project Information

Drawing Information

Drawn By:

Drawn Drawn:

Checked By:

Last Modified:o

0 400200

Feet

Figure A-4

Project No:

B2204326

ZS

7/18/2022

HGH

7/18/2022

Soil Boring Location Sketch

- East

FA4

Drawing No:

F :\2

2\

B

6\ G

IS

\B

6.

ap rx

Bluff Boulevard Reconstruction

Between College Avenue and 7th Avenue North

Clinton, Iowa

1" = 400 Feet

!( Approximate Boring Location

Source: Google Earth Imagery

11529 W 79th St Suite 21 Lenexa, KS 66214

617 617

612 612

607 607

602 602

597 597

592 592

587 587

582 582

577 577

572.00

Legend Key Concrete

Fill

CL

SP

SM

Limestone

SC

Asphalt

Topsoil

Figure A-5: Subsurface ProĮle

Project ID:

Vert. Scale:

Hor. Scale:

Date:

Fence Diagram B2204326 Geotechnical EvaluaƟon 1"= 6' Bluī Blvd. ReconstrucƟon

NTS

08/08/2022 Clinton, Iowa

WL

0.8 1.2

9.0

13.0 13.8

B-

N

TW

REF

WL

0.5 0.8

3.0

8.0 9.0

B-

N

REF

WL

0.7 1.5

3.0

6.0

9.5

15.0

B-

N

WL

0.8 0.9

15.0

B-

N

WL

0.7

4.0

6.0 7.0

13.0 13.8

B-

N

TW

REF

WL

1.0

3.0

7.0

12.0

15.0

B-

N

TW

REF

WL

0.3 0.7 0.9

5.0

9.0

15.0

B-

N

WL

0.5 0.7

3.0 3.6

B-

N

REF

WL

0.5 0.8

3.5

5.5 6.1

B-

N

REF

613 613

608 608

603 603

598 598

593 593

588 588

583 583

578 578

573 573

568.00

Legend Key Asphalt

Concrete

Limestone

Fill

GP

SM

SP

CL

SC

Figure A-6: Subsurface ProĮle

Project ID:

Vert. Scale:

Hor. Scale:

Date:

Fence Diagram B2204326 Geotechnical EvaluaƟon 1"= 6' Bluī Blvd. ReconstrucƟon

NTS

08/08/2022 Clinton, Iowa

WL

0.5 0.8

3.5

5.5 6.1

B-

N

REF

WL

0.4 0.7

4.5

6.0

B-

N

REF

WL

0.3 0.6

3.0

6.0

9.5

12.0

B-

N

TW

WL

0.3 0.9 2.0

B-

N

REF

WL

0.4 0.7 1.5

B-

N

REF

WL

0.3 0.9

6.0 6.5

B-

N

REF

WL

0.8 1.3

4.5 5.0

B-

N

REF

WL

0.3 0.9 1.5 2.5

B-

N

REF

WL

0.8

5.0

8.0

13.0 13.6

B-

N

613 613

608 608

603 603

598 598

593 593

588 588

583 583

578 578

573 573

568.00

Legend Key Asphalt

CL

Topsoil

Limestone

SP

Fill

SM

Figure A-7: Subsurface ProĮle

Project ID:

Vert. Scale:

Hor. Scale:

Date:

Fence Diagram B2204326 Geotechnical EvaluaƟon 1"= 6' Bluī Blvd. ReconstrucƟon

NTS

08/08/2022 Clinton, Iowa

WL

0.7 0.8 2.0

B-

N

REF

WL

0.6

2.0 2.2

B-

N

REF

WL

0.6

2.0 2.5

B-

N

REF

WL

0.6

1.8

B-

N

REF

WL

0.7 1.5

3.0

6.0

8.0

13.0 13.8

B-

N

REF

WL

0.7

2.0

B-

N

REF

WL

1.5 2.5 2.7

B-

N

REF

WL

0.9

6.0 6.5

B-

N

TW

REF

WL

0.7

6.0 6.1

B-

N

Borings B-1 and B-2 Pavement Cores Bluff Boulevard Reconstruction

Clinton, Iowa sketch

HGH 7/21/2022

TW 7/21/2022

B2204326

NA 1 12

Boring B-3 and B-4 Pavement Cores

B2204326

NA 2 12

Borings B-5 and B-7 Pavement Cores

TW 7/21/2022

B2204326

NA 3 12

Boring B-8 and B-9 Pavement Cores

B2204326

NA 4 12

Borings B-10 and B-11 Pavement Cores

B2204326

NA 5 12

Boring B-12 and B-13 Pavement Cores

B2204326

NA 6 12

Borings B-14 and B-15 Pavement Cores

TW 7/21/2022

B2204326

NA 7 12

Boring B-16 and B-17 Pavement Cores

B2204326

NA 8 12

Borings B-18 and B-19 Pavement Cores

B2204326

NA 9 12

Boring B-20 and B-21 Pavement Cores

B2204326

NA 10 12

Borings B-22 and B-23 Pavement Cores

TW 7/21/2022

B2204326

NA 11 12

Boring B-25 and B-26 Pavement Cores

B2204326

NA 12 12

Elev./ Depth ft

613.2 0.8

612.8 1.2

605.0 9.0

601.0 13.0

600.2 13.8

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

CONCRETE, 9.5 inches APPARENT AGGREGATE BASE, 5 inches LEAN CLAY (CL), with Sand, brown to dark brown, moist, stiff to medium (LOESS)

LEAN CLAY with SAND (CL), trace Gravel, dark brown, moist, medium (GLACIAL TILL)

LIMESTONE, highly weathered, hard

END OF BORING

Sa m pl e Blows

(N-Value) Recovery

3-4-6 (10) 8"

TW

12"

1-2-3 (5) 8"

1-3-3 (6) 10"

50/3"

(REF)

2" qₚ tsf

MC

Tests or Remarks

LL=27, PL=19, PI=8

DD=108 pcf qᵤ=2 tsf

AUGER REFUSAL AT 13.8

FEET.

Water not observed while drilling.

Boring patched with Asphalt.

LOG OF BORING

See Descriptive Terminology sheet for explanation of abbreviations

Project Number B2204326 Geotechnical Evaluation Bluff Blvd. Reconstruction Clinton, Iowa

BORING: B-01

LOCATION: See attached sketch

LATITUDE: 41.83252 LONGITUDE: -90.22527

DRILLER: AL/AC/BG LOGGED BY: A. Schweizer START DATE: 06/24/22 END DATE: 06/24/22

SURFACE

ELEVATION: 614.0 ft RIG: 5501 METHOD: 3 1/4" HSA SURFACING: Pavement WEATHER: Sunny & 80-90

B2204326 Braun Intertec Corporation Print Date:08/01/2022 B-01 page 1 of 1 ft

615.5 0.5

615.2 0.8

613.0 3.0

608.0 8.0

607.0 9.0

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

CONCRETE, 6 inches FILL: CLAYEY SAND (SC), dark gray SANDY LEAN CLAY (CL), trace Gravel, brown, moist, stiff (GLACIAL TILL)

SILTY SAND with GRAVEL (SM), fine to coarse-grained, tan, moist, medium dense to dense (RESIDUUM)

LIMESTONE, highly weathered, hard

END OF BORING

Sa m pl e Blows

(N-Value) Recovery

6-4-5 (9) 10"

7-8-7 (15) 8"

7-15-30 (45) 8"

50/1"

(REF)

1" qₚ tsf

MC

Tests or Remarks

AUGER REFUSAL AT 9

FEET.

Water not observed while drilling.

Boring patched with Asphalt.

LOG OF BORING

See Descriptive Terminology sheet for explanation of abbreviations

Project Number B2204326 Geotechnical Evaluation Bluff Blvd. Reconstruction Clinton, Iowa

BORING: B-02

LOCATION: See attached sketch

LATITUDE: 41.83326 LONGITUDE: -90.22527

DRILLER: AL/AC/BG LOGGED BY: A. Schweizer START DATE: 06/24/22 END DATE: 06/24/22

SURFACE

ELEVATION: 616.0 ft RIG: 5501 METHOD: 3 1/4" HSA SURFACING: Pavement WEATHER: Sunny & 80-90

B2204326 Braun Intertec Corporation Print Date:08/01/2022 B-02 page 1 of 1 ft

615.3 0.7

614.5 1.5

613.0 3.0

610.0 6.0

606.5 9.5

601.0 15.0

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

CONCRETE, 8 inches FILL: CLAYEY SAND (SC), trace Gravel, dark gray FILL: POORLY GRADED SAND (SP), fine-grained, trace Gravel, dark brown, moist POORLY GRADED SAND (SP), fine-grained, brown, moist, loose (EOLIAN)

SANDY LEAN CLAY (CL), brown, moist, stiff

(GLACIAL TILL)

LEAN CLAY (CL), trace Gravel, tan and white, moist, medium to stiff (RESIDUUM)

END OF BORING

Sa m pl e Blows

(N-Value) Recovery

2-2-2 (4) 8"

1-2-3 (5) 8"

2-5-5 (10) 10"

1-2-5 (7) 8"

5-6-8 (14) 14" qₚ tsf

MC

Tests or Remarks

LL=23, PL=19, PI=4

Boring patched with Asphalt.

Water not observed while drilling.

LOG OF BORING

See Descriptive Terminology sheet for explanation of abbreviations

Project Number B2204326 Geotechnical Evaluation Bluff Blvd. Reconstruction Clinton, Iowa

BORING: B-03

LOCATION: See attached sketch

LATITUDE: 41.83409 LONGITUDE: -90.22329

DRILLER: AL/AC/BG LOGGED BY: A. Schweizer START DATE: 06/24/22 END DATE: 06/24/22

SURFACE

ELEVATION: 616.0 ft RIG: 5501 METHOD: 3 1/4" HSA SURFACING: Pavement WEATHER: Sunny & 80-90

B2204326 Braun Intertec Corporation Print Date:08/01/2022 B-03 page 1 of 1 ft

613.2 0.8

613.1 0.9

599.0 15.0

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

CONCRETE, 8 inches FILL: CLAYEY SAND (SC), fine to coarse-grained, trace Gravel, gray and brown, moist POORLY GRADED SAND (SP), fine-grained, brown, moist, loose (EOLIAN) becoming fine to medium grained at 13 feet.

END OF BORING

Sa m pl e Blows

(N-Value) Recovery

4-4-5 (9) 7"

1-2-3 (5) 7"

1-2-3 (5) 7"

1-3-4 (7) 5"

2-2-6 (8) 8" qₚ tsf

MC

Tests or Remarks

Boring patched with Asphalt.

Water not observed while drilling.

LOG OF BORING

See Descriptive Terminology sheet for explanation of abbreviations

Project Number B2204326 Geotechnical Evaluation Bluff Blvd. Reconstruction Clinton, Iowa

BORING: B-04

LOCATION: See attached sketch

LATITUDE: 41.83466 LONGITUDE: -90.22198

DRILLER: AL/AC/BG LOGGED BY: A. Schweizer START DATE: 06/24/22 END DATE: 06/24/22

SURFACE

ELEVATION: 614.0 ft RIG: 5501 METHOD: 3 1/4" HSA SURFACING: Pavement WEATHER: Sunny & 80-90

B2204326 Braun Intertec Corporation Print Date:08/01/2022 B-04 page 1 of 1 ft

611.3 0.7

608.0 4.0

606.0 6.0

605.0 7.0

599.0 13.0

598.2 13.8

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

CONCRETE, 8 inches FILL: CLAYEY SAND (SC), fine to coarse-grained, trace Gravel, with, Clay pockets, dark brown, moist

CLAYEY SAND (SC), fine-grained, brown, moist, loose (EOLIAN)

LEAN CLAY (CL), brown, moist, stiff (LOESS)

SILTY SAND (SM), fine-grained, tan, moist

(RESIDUUM)

LIMESTONE, highly weathered, hard

END OF BORING

Sa m pl e Blows

(N-Value) Recovery

7-3-3 (6) 5"

1-3-5 (8) 8"

2-4-10 (14) 8"

TW

50/2"

(REF)

2" qₚ tsf

1.25

MC

Tests or Remarks

Water observed at 13.5 feet while drilling.

AUGER REFUSAL AT 13.8

FEET.

Boring patched with Asphalt.

LOG OF BORING

See Descriptive Terminology sheet for explanation of abbreviations

Project Number B2204326 Geotechnical Evaluation Bluff Blvd. Reconstruction Clinton, Iowa

BORING: B-05

LOCATION: See attached sketch

LATITUDE: 41.83521 LONGITUDE: -90.22064

DRILLER: AL/AC/BG LOGGED BY: A. Schweizer START DATE: 06/24/22 END DATE: 06/24/22

SURFACE

ELEVATION: 612.0 ft RIG: 5501 METHOD: 3 1/4" HSA SURFACING: Pavement WEATHER: Sunny & 80-90

B2204326 Braun Intertec Corporation Print Date:08/01/2022 B-05 page 1 of 1 ft

603.0 1.0

601.0 3.0

597.0 7.0

592.0 12.0

589.0 15.0

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

TOPSOIL, 12 inches

CLAYEY SAND (SC), fine-grained, brown, moist, loose (EOLIAN)

LEAN CLAY (CL), brown, moist, medium

(LOESS)

LEAN CLAY (CL), trace Sand, and Gravel, tan, moist, medium (RESIDUUM)

LIMESTONE, highly weathered, hard

END OF BORING

Sa m pl e Blows

(N-Value) Recovery

2-2-2 (4) 6"

TW

2"

1-2-4 (6) 5"

4-4-11 (15) 7"

6-50/2"

(REF)

1" qₚ tsf

MC

Tests or Remarks

LL=38, PL=17, PI=21

Water not observed while drilling.

Boring patched with Asphalt.

LOG OF BORING

See Descriptive Terminology sheet for explanation of abbreviations

Project Number B2204326 Geotechnical Evaluation Bluff Blvd. Reconstruction Clinton, Iowa

BORING: B-06

LOCATION: See attached sketch

LATITUDE: 41.83588 LONGITUDE: -90.21882

DRILLER: AL/AC/BG LOGGED BY: A. Schweizer START DATE: 06/24/22 END DATE: 06/24/22

SURFACE

ELEVATION: 604.0 ft RIG: 5501 METHOD: 3 1/4" HSA SURFACING: Pavement WEATHER: Sunny & 80-90

B2204326 Braun Intertec Corporation Print Date:08/01/2022 B-06 page 1 of 1 ft

605.7 0.3

605.3 0.7

605.1 0.9

601.0 5.0

597.0 9.0

591.0 15.0

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

ASPHALT PAVEMENT, 4 inches BRICK, 3.5 inches FILL: CLAYEY SAND (SC), fine to coarse-grained, dark brown FILL: POORLY GRADED SAND (SP), fine-grained, trace Gravel, brown, moist

POORLY GRADED SAND (SP), fine-grained, brown, moist, loose (EOLIAN)

LEAN CLAY (CL), reddish brown and brown, moist, medium to soft (RESIDUUM)

END OF BORING

Sa m pl e Blows

(N-Value) Recovery

3-4-4 (8) 8"

3-3-3 (6) 8"

2-3-4 (7) 10"

2-3-3 (6) 12"

1-2-2 (4) 13" qₚ tsf

MC

Tests or Remarks

LL=22, PL=14, PI=8

Water observed at 14.5 feet while drilling.

Boring patched with Asphalt.

LOG OF BORING

See Descriptive Terminology sheet for explanation of abbreviations

Project Number B2204326 Geotechnical Evaluation Bluff Blvd. Reconstruction Clinton, Iowa

BORING: B-07

LOCATION: See attached sketch

LATITUDE: 41.83652 LONGITUDE: -90.21781

DRILLER: AL/AC/BG LOGGED BY: A. Schweizer START DATE: 06/30/22 END DATE: 06/30/22

SURFACE

ELEVATION: 606.0 ft RIG: 5501 METHOD: 3 1/4" HSA SURFACING: Pavement WEATHER: Sunny & 80-90

B2204326 Braun Intertec Corporation Print Date:08/01/2022 B-07 page 1 of 1 ft

606.5 0.5

606.3 0.7

604.0 3.0

603.4 3.6

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

ASPHALT PAVEMENT, 5 inches BRICK, 3.5 inches POORLY GRADED SAND (SP), fine to coarse-grained, trace Gravel, brown, moist, medium dense (RESIDUUM) LIMESTONE, highly weathered, hard

END OF BORING

Sa m pl e Blows

(N-Value) Recovery

3-13-17 (30) 2"

50/1"

(REF)

0" qₚ tsf

MC

% Tests or Remarks

AUGER REFUSAL AT 3.6

FEET.

Water not observed while drilling.

Boring patched with Asphalt.

LOG OF BORING

See Descriptive Terminology sheet for explanation of abbreviations

Project Number B2204326 Geotechnical Evaluation Bluff Blvd. Reconstruction Clinton, Iowa

BORING: B-08

LOCATION: See attached sketch

LATITUDE: 41.83704 LONGITUDE: -90.21686

DRILLER: AL/AC/BG LOGGED BY: A. Schweizer START DATE: 06/30/22 END DATE: 06/30/22

SURFACE

ELEVATION: 607.0 ft RIG: 5501 METHOD: 3 1/4" HSA SURFACING: Pavement WEATHER: Sunny & 80-90

B2204326 Braun Intertec Corporation Print Date:08/01/2022 B-08 page 1 of 1 ft

606.5 0.5

606.2 0.8

603.5 3.5

601.5 5.5

600.9 6.1

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

ASPHALT PAVEMENT, 5.5 inches BRICK, 3.5 inches POORLY GRADED SAND (SP), fine to coarse-grained, trace Gravel, brown, moist, medium dense (RESIDUUM) SANDY LEAN CLAY (CL), trace Gravel, brown, moist, very stiff (RESIDUUM)

LIMESTONE, highly weathered, hard

END OF BORING

Sa m pl e Blows

(N-Value) Recovery

6-7-5 (12) 6"

2-2-16 (18) 10"

50/1"

(REF)

0" qₚ tsf

MC

Tests or Remarks

LL=29, PL=19, PI=10

AUGER REFUSAL AT 6.1

FEET.

Water not observed while drilling.

Boring patched with Asphalt.

LOG OF BORING

See Descriptive Terminology sheet for explanation of abbreviations

Project Number B2204326 Geotechnical Evaluation Bluff Blvd. Reconstruction Clinton, Iowa

BORING: B-09

LOCATION: See attached sketch

LATITUDE: 41.83767 LONGITUDE: -90.21575

DRILLER: AL/AC/BG LOGGED BY: A. Schweizer START DATE: 06/30/22 END DATE: 06/30/22

SURFACE

B2204326 Braun Intertec Corporation Print Date:08/01/2022 B-09 page 1 of 1 ft

606.6 0.4

606.3 0.7

602.5 4.5

601.0 6.0

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

ASPHALT PAVEMENT, 4 inches BRICK, 4 inches SILTY…