Geotechnical_Report_BRIDGE_B119_0002.pdf

REPORT COVER PAGE

Geotechnical Engineering Report

Kickapoo Bridge Replacement

Near Horton, Kansas

March 7, 2023

Terracon Project No. 14225103.1

Prepared for:

Kickapoo Tribe c/o BG Consultants, Inc.

Manhattan, Kansas

Prepared by:

Terracon Consultants, Inc.

Topeka, Kansas

Terracon Consultants, Inc. 2016 SW 37 th Street Topeka, Kansas 66611

(785) 267 3310 terracon.com

REPORT COVER LETTER TO SIGN

March 7, 2023

Kickapoo Tribe c/o BG Consultants, Inc.

4806 Vue Du Lac Place

Manhattan, Kansas 66503

Attn: Mr. Brady Hedstrom, P.E.

P: (785) 712 2676

E: brady.hedstrom@bgcons.com

Re: Geotechnical Engineering Report

Kickapoo Bridge Replacement

140th Street over a Tributary of the Delaware River

Near Horton, Kansas

Terracon Project No. 14225103.1

Dear Mr. Hedstrom:

We have completed the Geotechnical Engineering services for the above referenced project. This study was performed in general accordance with Terracon Proposal No. P14225103 dated

December 21, 2022. This report presents the findings of the subsurface exploration and provides geotechnical recommendations concerning earthwork and the design and construction of foundations for the proposed project.

We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report or if we may be of further service, please contact us.

Sincerely, Terracon Consultants, Inc.

Michael A. Snapp, P.E. Jamie M. Klein, P.E.

Geotechnical Engineer Senior Associate

Kansas PE: 27005 Kansas PE: 22112

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REPORT TOPICS

INTRODUCTION

SITE CONDITIONS

PROJECT DESCRIPTION

GEOTECHNICAL CHARACTERIZATION

GEOTECHNICAL OVERVIEW

EARTHWORK

DEEP FOUNDATIONS

LATERAL EARTH PRESSURES

GENERAL COMMENTS

ATTACHMENTS

Note: This report was originally delivered in a web-based format. For more interactive features, please view your project online at client.terracon.com.

ATTACHMENTS

EXPLORATION AND TESTING PROCEDURES

SITE LOCATION AND EXPLORATION PLAN

EXPLORATION RESULTS

• Boring Logs with Laboratory Data

• GeoModel

• Rock Core Photo Log

SUPPORTING INFORMATION

• General Notes

• Unified Soil Classification System

• Description of Rock Properties

Note: Refer to each individual Attachment for a listing of contents.

http://client.terracon.com/

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INTRODUC TRIBUGeotechnical Engineering Report

Kickapoo Bridge Replacement

140th Street over a Tributary of the Delaware River

Near Horton, Kansas Terracon Project No. 14225103.1

March 7, 2023

INTRODUCTION

This report presents the results of our subsurface exploration and geotechnical engineering services performed for the proposed bridge replacement located where 140th Street crosses over a tributary of the Delaware River approximately 7 miles northwest of Horton, Kansas. The purpose of these services is to provide information and geotechnical engineering recommendations relative to:

■ Subsurface soil and rock conditions ■ Site preparation and earthwork

■ Groundwater conditions ■ Foundation design and construction

The geotechnical engineering Scope of Services for this project included the advancement of

2 test borings to depths ranging from approximately 44.5 to 46 feet below existing site grades.

Maps showing the site and boring locations are shown in the Site Location and Exploration

Plans section. The results of the laboratory testing performed on soil samples obtained from the site during the field exploration are included on the boring logs in the Exploration Results section.

SITE CONDITIONS

The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps.

Item Description

Parcel Information

The project is located where 140th Street crosses over a tributary of the

Delaware River northwest of Horton, Kansas.

Approximate Coordinates: 39.710806, -95.645389

Existing

Improvements

Based upon provided plans, we understand the existing structure is an 84 foot, 3-span continuous concrete slab bridge.

Existing Topography

The roadway is elevated above the creek channel and associated low-lying areas with the road embankment having moderate to steep side-slopes.

Based on the provided plan/profile sheets, the creek channel is incised approximately 20 feet below 140th Street.

Kickapoo Bridge Replacement ■ Near Horton, Kansas

March 7, 2023 ■ Terracon Project No. 14225103.1

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PROJECT DESCRIPTION

Our initial understanding of the project was provided in our proposal and was discussed during project planning. A period of collaboration has transpired since the project was initiated, and our final understanding of the project conditions is as follows:

Item Description

Information Provided

Our understanding of the project is from conversation and email correspondence with the BG Consultants and provided Preliminary Plan and

Profile Sheets for Site 1, B119.

Project Description

We understand the improvements at the project site are anticipated to include removal of the existing bridge and construction of a new, three-span reinforced concrete haunched slab (RCSH) bridge. Bridge B119 will be located along the existing roadway alignment and likely have span lengths of 33 ft.–44 ft.–33 ft.

We understand the abutments and the intermediate bents are planned to be supported by driven piles.

Grading/Slopes

Based on the provided Plan and Profile sheets for Site 1, Bridge B119, up to about 10 feet of cut may be required to widen the existing channel. We expect general site grading to include less than approximately 5 feet of cut and fill to possibly reshape side slopes of the existing road embankments.

Slope Stability

As there is an existing bridge present at the site, it may not be necessary to perform global slope stability analysis of the spill slopes unless the slopes are steepened. We could provide a proposal for these services upon request.

Terracon should be notified if any of the above information is inconsistent with the planned construction, especially the grading limits, as modifications to our recommendations may be necessary.

GEOTECHNICAL CHARACTERIZATION

Geology

The site is located within the Delaware River floodplain which typically consists of Quaternary aged alluvial (water-deposited) soils generally comprised of clay and sand/gravel materials. The soils overlie Carboniferous aged bedrock from the Admire Group. Based on our review of Brown

County geology, we believe the bedrock encountered in the borings is part of the Janesville Shale which includes the Hamlin Shale, Five Point Limestone and West Branch Shale Members.

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Subsurface Profile

We have developed a general characterization of the subsurface conditions based upon our review of the subsurface exploration, laboratory data, geologic setting and our understanding of the project. This characterization, termed GeoModel, forms the basis of our geotechnical calculations and evaluation of site preparation and foundations. Detailed conditions encountered at each exploration point are indicated on the individual logs. The individual boring logs and

GeoModel can be found in the Exploration Results section of this report. Stratification boundaries on the boring logs and GeoModel represent the approximate location of changes in stratum type; however, in situ the transition between native materials may be gradual while in existing fill changes could be abrupt.

Groundwater Conditions

The boreholes were observed while auger drilling for the presence and level of groundwater.

Groundwater was observed at a depth of 28 feet while sampling in Boring B-2 but was not observed in Boring B-1 prior to the introduction of drilling fluid. However, this does not necessarily mean a stable groundwater level was observed in Boring B-2, or that the augered portion of Boring B-1 was completed above groundwater. A longer period of time may be required for groundwater to develop and stabilize in a borehole. Longer term observations in piezometers or observation wells, sealed from the influence of surface water, are often required to define groundwater levels.

We would generally expect the groundwater level at this site to be near or above the water level in the tributary. However, groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff, the water level in the tributary and other factors not evident at the time the borings were performed. In addition, perched water can develop over low permeability soil or rock strata. Therefore, groundwater levels during construction or at other times in the life of the structure may be higher or lower than the observations made during our subsurface exploration.

The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project.

GEOTECHNICAL OVERVIEW

Based on the subsurface conditions, planned construction, and our analysis, it is our opinion the proposed bridge can be supported as planned by driven steel piles that would derive capacity from the weathered bedrock. We anticipate pre-boring may be required for the driven piles at the intermediate piers to develop sufficient pile lengths for scour protection and/or lateral capacity.

With seasonal water level fluctuations in the tributary, it is difficult to predict the near surface groundwater conditions that will be present during construction. The potential for soft subgrade soils during earthwork activities for the project should be anticipated by the contractor.

Accordingly, stabilization of subgrade soils prior to placement of embankment soils should be

Responsive ■ Resourceful ■ Reliable 4 anticipated and considered when budgeting for the project. Additional considerations regarding stabilization are included in the Earthwork section of this report below. Further, the potentially shallow groundwater conditions resulting from the proximity to the tributary indicate that the contractor should be prepared for dewatering at the site.

We recommend the exposed subgrade be thoroughly evaluated after site stripping and the removal of unsuitable existing fill, but prior to the start of any fill operations. We recommend the geotechnical engineer be retained to evaluate and observe earthwork operations and foundation installation procedures. Subsurface conditions, as identified by the field and laboratory testing programs, have been reviewed and evaluated with respect to the proposed project plans known to us at this time.

The recommendations presented in the following sections consider the proposed structure, site grading, and the location of the project are as outlined earlier within this report. Terracon should be contacted immediately if conditions are different than described as this may impact our recommendations.

EARTHWORK

Site Preparation

Once all cuts have been performed to accommodate the planned construction, the subgrade soils should be evaluated prior to placement of the new fill. Unsuitable materials, including vegetation, topsoil, construction debris and unsuitable fill should be removed to full depth. Wet or dry material should also be removed; if otherwise suitable, such materials can be moisture conditioned and placed with moisture and density control in engineered fills. The exact depth of remediation, if any, should be determined in the field during site grading based on the actual extent of unsuitable material encountered.

After stripping and removal of unsuitable soils (if any) the subgrade should be proof-rolled where possible to aid in locating loose or soft areas. Proof-rolling can be performed with a loaded tandem axle dump truck or other equipment providing an equivalent subgrade loading. Where proofrolling is not possible, we recommend the subgrade be evaluated by other means, possibly including the use of a steel T-probe, test pits, or Shelby tube samples. Soft, dry and low-density soil should be removed, compacted in place prior to placing fill or stabilized as recommended in the Earthwork Construction Considerations section.

New Fill Materials and Placement

Newly placed engineered fill should consist of approved materials that are free of organic matter and debris. Based on the results of our borings, material suitable for re-use as engineered fill may be present at the site provided any deleterious materials, if present, are removed. Off-site

Responsive ■ Resourceful ■ Reliable 5 borrow material should be approved by the geotechnical engineer of record prior to being imported to the site. Samples of each proposed off-site borrow material should be submitted to the geotechnical engineer of record for classification testing. Frozen material should not be used, and fill should not be placed on a frozen subgrade.

Areas where fill is required to develop design grades and areas undercut to remove unsuitable or soft materials should be filled with controlled engineered fill. Fill should be placed and compacted in loose lifts of 9 inches or less and compacted to at least 95% of the material's standard Proctor maximum dry density (KDOT Type AA Compaction). The moisture content of the fill at the time of compaction should be within 3 percentage points of the material’s standard Proctor optimum moisture content (KDOT MR-3-3 Moisture Range).

Where fill is placed on existing slopes steeper than 5H:1V, benches should be cut into the existing slopes prior to fill placement. The benches should have a minimum vertical face height of 1 foot and a maximum vertical face height of 3 feet and should be cut wide enough to accommodate the compaction equipment. This benching will help provide a positive bond between the fill and natural soils and reduce the possibility of failure along the fill/natural soil interface. Furthermore, we recommend that fill slopes be over filled and then cut back to develop an adequately compacted slope face.

Earthwork Construction Considerations

With seasonal water level fluctuations in the tributary, it is difficult to predict the near surface groundwater conditions that will be present during construction. The potential for soft subgrade soils during earthwork activities for the project should be anticipated by the contractor.

Accordingly, stabilization of subgrade soils prior to placement of embankment soils should be anticipated and considered when budgeting for the project.

Should unstable subgrade conditions be encountered, the methods described below could be considered to improve subgrade strength. Common methods include scarification, moisture conditioning and recompaction, and removal of unstable materials and replacement with granular fill (with or without geosynthetics). The appropriate method of improvement, if required, depends on factors such as schedule, weather, the size of area to be stabilized, and the nature of the instability.

If the exposed subgrade becomes unstable, methods outlined below can be considered.

◼ Scarification and Recompaction - It may be feasible to scarify, dry, and recompact the exposed soils. The success of this procedure would depend primarily upon favorable weather and sufficient time to dry the soils. Stable subgrades likely would not be achievable if the thickness of the unstable soil is greater than about 1 foot, if the unstable soil is at or near groundwater levels, or if construction is performed during a period of wet or cool weather when drying is difficult.

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◼ Crushed Stone - The use of crushed stone or crushed gravel is the most common procedure to improve subgrade stability. Typical undercut depths would be expected to range from about

6 to 30 inches below finished subgrade elevation. The use of high modulus geotextiles (i.e., engineering fabric or geogrid) could also be considered after underground work such as utility construction is completed. Prior to placing the fabric or geogrid, we recommend that all below grade construction, such as utility line installation, be completed to avoid damaging the fabric or geogrid. Equipment should not be operated above the fabric or geogrid until one full lift of crushed stone fill is placed above it. The maximum particle size of granular material placed over geotextile fabric or geogrid should not exceed 1½ inches.

Further evaluation of the need and recommendations for subgrade stabilization should be provided by a qualified geotechnical engineer during construction as the subgrade conditions are exposed on a broad scale.

Temporary excavations will probably be required during grading operations. The grading contractor, by his contract, is usually responsible for designing and constructing stable, temporary excavations and should shore, slope or bench the sides of the excavations as required, to maintain stability of both the excavation sides and bottom. All excavations should comply with applicable local, state and federal safety regulations, including the current Occupational Safety and Health Administration (OSHA) Excavation and Trench Safety Standards.

Construction Observation and Testing

The earthwork efforts should be monitored under the direction of the Geotechnical Engineer.

Monitoring should include documentation of adequate removal of vegetation and top soil, evaluation of existing fill materials, proof-rolling and mitigation of areas delineated by the proof-roll to require mitigation.

Each lift of compacted fill should be tested, evaluated, and reworked as necessary until approved by the Geotechnical Engineer prior to placement of additional lifts. In areas of shallow foundation excavations, the bearing subgrade should be evaluated under the direction of the Geotechnical

Engineer. In the event unanticipated conditions are encountered, the Geotechnical Engineer should prescribe mitigation options.

In addition to the documentation of the essential parameters necessary for construction, the continuation of the Geotechnical Engineer into the construction phase of the project provides the continuity to maintain the Geotechnical Engineer’s evaluation of subsurface conditions, including assessing variations and associated design changes.

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DEEP FOUNDATIONS

Based on the subsurface conditions encountered at the boring locations, it is our opinion the planned bridge could be supported as planned by deep foundations consisting of driven piles. As previously described pre-boring for driven piles at the intermediate bents may be required to develop sufficient depth for scour protection and/or lateral capacity. Recommendations for the design and construction of driven piles are discussed in the following sections.

Driven Steel Pile Design Parameters

Steel H-piles (HP sections) should be driven through the native soils to achieve bearing in the underlying weathered limestone or shale, using an appropriately sized hammer. The table below provides the upper elevation of bedrock as encountered in the borings and the depth at which we anticipate the piles will achieve the recommended capacity.

Based on Section 10.7.3.2.3 of the AASHTO LRFD Bridge Design Specifications (2012), the nominal resistance of piles driven to point bearing on competent bedrock is controlled by the structural limit state. The nominal compressive resistance of the piles for various limit states should be designed in accordance with Section 6 of the referenced AASHTO specifications.

According to Section 6.5.4.2 of the referenced AASHTO specifications, a structural resistance factor of 0.50 is applicable for H-piles (with pile tips) due to potential damage to the pile while driving through the alluvial materials and into competent bedrock.

Considering the above information, the nominal resistances for HP10x42 and HP12x53 piles composed of steel with a 50 ksi allowable yield stress, driven to refusal in limestone or shale bedrock, and driven with a pile tip, are shown in the following table. If other pile sizes or types will be considered, Terracon should be contacted to provide additional recommendations.

Pile Location Pile Size

Nominal Pile

Resistance 1

(kips)

Factored Pile

Resistance

(kips)

Upper

Elevation 2 of Bedrock

(feet)

Estimated

Tip

Elevation 3, 4

(feet)

West Abutment

Near Boring B-1

HP 10x42 620 310

1022.5 1022

HP 12x53 775 387.5

East Abutment

Near Boring B-2

HP 10x42 620 310

1022.5 1017.5

HP 12x53 775 387.5

1. These nominal resistance values are applicable if the center-to-center spacing of piles is equal to or greater than 3 times the maximum pile section dimension. If the piles will be spaced closer, a reduction in the design pile capacity would be required based on the geometry of the pile spacing. Terracon should be notified if closer pile spacing is planned.

2. Based on the elevations as shown on the boring logs.

3. All piles should be monitored during driving in order to avoid damage.

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4. The quality and strength of the bedrock may vary, and refusal to driving conditions could be encountered at shallower or deeper elevations. Therefore, actual pile lengths may vary. If pre-drilling is required, the values shown above are valid for tip elevations below the elevations shown, provided field observation/PDA testing indicates capacity has been achieved.

We anticipate any uplift forces will be resisted by the weight of the bridge. For driven piles that designed according as recommended in this report, constructed in accordance with KDOT requirements, and observed during construction, we anticipate that the long-term settlement of would be about ½-inch for the Service I Limit State loading, in addition to elastic shortening of the pile materials.

We recommend welding reinforced high strength cast steel tips to the bottom of the H-piles to reduce the potential for pile damage during driving and allow the pile to penetrate into suitable bedrock. We recommend using Associated Pile and Fitting Company (APF) 77600 pile tips, or approved equivalent, such as DFP H-776 or Versabite VB-300P.

Steel piles are subject to corrosion. Selection of a pile section capable of transmitting design loads through the corrosion-reduced section area is a typical method of protection.

Frost action beneath abutments can cause uplift loads on the piles. To avoid potential uplift loads, the base of the abutments should extend a minimum of 3 feet below grade. Requirements of resistance to lateral and uplift loads for the structure were not provided. We estimate that HP piles driven through native soil to refusal in suitable bedrock, or pre-bored into bedrock, would be capable of resisting lateral loads of approximately 5 kips. If piles will be subjected to lateral loads greater than 5 kips, additional analyses, such as LPILE, should be performed to evaluate lateral load capacity. The following table lists input values for use in LPILE analyses. LPILE will estimate values of kh and E50 based on strength; however, non-default values of kh should be used where provided. Since deflection or a service limit criterion will most likely control lateral capacity design, no safety/resistance factor is included with the parameters.

Material / Bottom of

Layer Elevation

L-Pile Soil Model Su (psf)

2 (pcf) 2, 3 ε50

K

(pci) qu

(psi)

Existing Fill /

3 ft. from surface

Stiff Clay w/o

Free Water 2,250 120 Ignore Ignore ---

Stiff Clays

1049 feet

Stiff Clay w/o

Free Water 2,250 120 0.006 750 ---

Soft to Medium Stiff Clays

1022.5 feet

Stiff Clay w/o

Free Water 750 120 0.015 125 ---

Limestone and Shale Weak Rock 8,000 130 0.0005 2,000 250

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1. The soil values/elevations are for use at the abutments and are based on the results of Borings B-1 and B-2.

The rock values are for use at the abutments and piers. See Subsurface Profile in Geotechnical

Characterization for more details on Stratigraphy.

2. Definition of Terms:

Su: Undrained shear strength

Moist unit weight ε50: Non default E50 strain

K: Non-default soil modulus – static. Refer to software guidelines for cyclic loading.

qu: Unconfined compressive strength of rock.

3. Buoyant unit weight values should be used below water table.

Driven Pile Construction Considerations

Driven piles should be installed in accordance with the KDOT Bridge Manual. Pile driving through the upper soils is not expected to be difficult; however, the alluvial soils could contain gravel, cobbles or boulders which result in difficult driving conditions. Furthermore, as described above, penetration into weathered limestone or shale bedrock may occur depending on driving effort and resistance. Therefore, we recommend that point reinforcement and/or flange stiffening be considered to protect pile tips from damage during potential hard driving conditions which may occur as the design capacity is being obtained.

Since variations may occur in depth and strength of the bedrock and the strength and composition of the overlying soil layers, piles should be driven until satisfactory driving resistance is developed for the design capacity as evaluated in accordance with an appropriate pile driving formula or by wave equation analysis and verified with a pile driving analyzer.

Care should be taken not to overdrive and damage the piles during installation. Pile installation should be performed by an experienced, knowledgeable contractor who is familiar with the subsurface conditions in the region of the project site. The contractor should be prepared to cut or splice piles, as necessary. Pile installation should be observed by Terracon or other qualified personnel retained to evaluate the installation of the driven piles to assess when adequate bearing has been achieved.

LATERAL EARTH PRESSURES

Design Parameters

Structures with unbalanced backfill levels on opposite sides should be designed for earth pressures at least equal to values indicated in the following table. Earth pressures will be influenced by structural design of the walls, conditions of wall restraint, methods of construction and/or compaction and the strength of the materials being restrained. Two wall restraint conditions

Responsive ■ Resourceful ■ Reliable 10 are shown below. Active earth pressure is commonly used for design of free-standing cantilever retaining walls and assumes wall movement. The "at-rest" condition assumes no wall movement and is commonly used for basement walls, loading dock walls, or other walls restrained at the top.

The recommended design lateral earth pressures do not include a factor of safety and do not provide for possible hydrostatic pressure on the walls.

Earth Pressure Coefficients

Earth Pressure Condition

Coefficient for Backfill Type

Equivalent Fluid

Density (pcf) Surcharge

Pressure, p1 (psf) Earth Pressure, p2 (psf)

Active (Ka)

Granular – 0.3

Lean Clay – 0.42

Lean to Fat Clay – 0.45

(0.3)S

(0.42)S

(0.45)S

(40)H

(50)H

(55)H

At-Rest (Ko)

Granular – 0.47

Lean Clay – 0.59

Lean to Fat Clay – 0.63

(0.47)S

(0.59)S

(0.63)S

(60)H

(70)H

(75)H

Passive (Kp)

Granular – 3.3

Lean Clay – 2.4

Lean to Fat Clay – 2.2

Applicable conditions to the table above include:

■ For active earth pressure, wall must rotate about base, with top lateral movements of about

0.002 H to 0.004 H, where H is wall height

■ For passive earth pressure to develop, wall must move horizontally to mobilize resistance.

■ Uniform surcharge, where S is surcharge pressure

■ Granular backfill: unit weight = 130 pcf (maximum), and = 32 degrees (minimum)

■ Lean clay soil backfill: unit weight = 120 pcf (maximum), and = 24 degrees (minimum)

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■ Lean to fat clay backfill: unit weight = 120 pcf (maximum), and = 22 degrees (minimum)

■ Horizontal backfill, compacted as recommended herein

■ Loading from heavy compaction equipment not included

■ No hydrostatic pressures acting on wall

■ No loading from nearby footings or slabs

■ No dynamic loading

■ No safety factor included in soil parameters

■ Ignore passive pressure in frost zone

Backfill placed against structures should consist of granular soils or low plasticity cohesive soils.

For the granular values to be valid, the granular backfill must extend out from the base of the wall at an angle of at least 45, 45 and 60 degrees from vertical for the active, at-rest and passive cases, respectively. To calculate the resistance to sliding, a value of 0.32 should be used as the ultimate coefficient of friction between the footing and the underlying soil.

The lateral earth pressure recommendations given in this section are applicable to the design of rigid retaining walls subject to slight rotation, such as cantilever, or gravity type concrete walls.

These recommendations are not applicable to the design of modular block - geogrid reinforced backfill walls (also termed MSE walls). Recommendations covering these types of wall systems are beyond the scope of services for this assignment. However, we would be pleased to develop a proposal for evaluation and design of such wall systems upon request.

Subsurface Drainage for Below-Grade Walls

A perforated rigid plastic drain line installed behind the base of walls and extends below adjacent grade is recommended to prevent hydrostatic loading on the walls. The invert of a drain line around a below-grade building area or exterior retaining wall should be placed near foundation bearing level. The drain line should be sloped to provide positive gravity drainage to daylight or to a sump pit and pump. The drain line should be surrounded by clean, free-draining granular material having less than 5% passing the No. 200 sieve, such as No. 57 aggregate. The free-draining aggregate should be encapsulated in a filter fabric. The granular fill should extend to within 2 feet of final grade, where it should be capped with compacted cohesive fill to reduce infiltration of surface water into the drain system.

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As an alternative to free-draining granular fill, a pre-fabricated drainage structure may be used. A pre-fabricated drainage structure is a plastic drainage core or mesh which is covered with filter fabric to prevent soil intrusion, and is fastened to the wall prior to placing backfill.

GENERAL COMMENTS

Our analysis and opinions are based upon our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration. Natural variations will occur between exploration point locations or due to the modifying effects of construction or weather.

The nature and extent of such variations may not become evident until during or after construction.

Terracon should be retained as the Geotechnical Engineer, where noted in this report, to provide observation and testing services during pertinent construction phases. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations.

Our Scope of Services does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken.

Our services and any correspondence or collaboration through this system are intended for the sole benefit and exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices with no third-party beneficiaries intended. Any third-party access to services or correspondence is solely for information purposes to support the services provided by Terracon to our client.

Reliance upon the services and any work product is limited to our client, and is not intended for third parties. Any use or reliance of the provided information by third parties is done solely at their own risk. No warranties, either express or implied, are intended or made.

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Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly impact excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for specific purposes to obtain the specific level of detail necessary for costing.

Site safety, cost estimating, excavation support, and dewatering requirements/design are the responsibility of others. If changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing.

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ATTACHMENTS

Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 1 of 2

EXPLORATION AND TESTING PROCEDURES

Field Exploration

The field exploration program consisted of the following:

Number of Borings Boring Depth (feet) Location

1 46 Near west end of existing bridge

1 44.5 Near east end of existing bridge

1. Below existing ground surface.

2. The boring locations are shown on the attached Exploration Plan

Boring Layout and Elevations: Terracon personnel provided the boring layout using handheld

GPS equipment (estimated horizontal accuracy of about ±10 feet) and referencing existing site features. Approximate ground surface elevations were obtained by interpolation from the provided topographic site plan. If more precise ground surface elevations and/or boring locations are desired, we recommend the borings be surveyed by a professional land surveyor.

Subsurface Exploration Procedures: We advanced the borings with a track-mounted rotary drill rig using continuous flight hollow stem augers and rotary wash boring techniques. Three samples were obtained in the upper 10 feet of each boring and at intervals of 5 feet thereafter. In the thin-walled tube sampling procedure, a thin-walled, seamless steel tube with a sharp cutting edge is pushed hydraulically into the soil to obtain a relatively undisturbed sample. In the split-barrel sampling procedure, a standard 2-inch outer diameter split-barrel sampling spoon is driven into the ground by a 140-pound automatic hammer falling a distance of 30 inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration is recorded as the

Standard Penetration Test (SPT) resistance value. The SPT resistance values, also referred to as

N-values, are indicated on the boring logs at the test depths. Rock coring was performed using an

NQ sized core barrel.

We also observed and recorded groundwater levels during drilling and sampling. The groundwater levels are shown on the attached boring log.

Our exploration team prepared field boring logs during drilling operations to record sampling depths, penetration distances, other relevant sampling information, visual classifications of materials encountered during drilling, and our interpretation of subsurface conditions between samples. Final boring logs, prepared from field logs, represent the geotechnical engineer's interpretation, and include modifications based on observations and laboratory tests.

Property Disturbance: We backfilled the boring with auger cuttings and bentonite chips after completion. Our services do not include repair of the site beyond backfilling our borehole. Excess

Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 2 of 2 auger cuttings and drill fluid were dispersed in the general vicinity of the borehole. Because backfill material often settles below the surface after a period, we recommend the borehole be checked periodically and backfilled, if necessary.

Laboratory Testing

The project engineer reviewed the field data and assigned laboratory tests. The laboratory testing program included the following types of tests:

■ Moisture Content

■ Dry Unit Weight

■ Unconfined Compression

The laboratory testing program included examination of soil samples by an engineer or geologist.

Based on the material’s texture and plasticity, we described and classified the soil samples in accordance with the attached Unified Soil Classification System (USCS).

Rock classification was conducted using locally accepted practices for engineering purposes and was based on drilling characteristics and observation of disturbed samples and auger cuttings;

rock core samples and petrographic analysis may reveal other rock types. Boring log rock classification was determined using the Description of Rock Properties.

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SITE LOCATION AND EXPLORATION PLANS

Contents:

Site Location Plan

Exploration Plan

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SITE LOCATION PLAN

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MAP 1 PORTRA IT

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS

EXPLORATION PLAN

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MAP 2 LANDSCAPE

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS

EXPLORATION RESULTS

Boring Logs (B-1 and B-2)

GeoModel

Rock Core Photo Log

4-9-10 N=19

3-3-5 N=8 3-4-5 N=9

3-3-2 N=5

3-2-1 N=3

2-1-1 N=2

3-2-2 N=4

50/6"

RQD = 83%

RQD = 52%

RQD = 33%

13.0

20.0

25.5

23.1

26.4

30.8

29.2

28.8

29.1

6 INCHES AGGREGATE

LEAN TO FAT CLAY, trace silt, sand, gravel, and concrete fragments, gray

LEAN TO FAT CLAY (CL/CH), trace silt, grayish tan, soft to stiff trace sand

LIMESTONE, light gray, slight weathering

SHALE, gray, severe to moderate weathering dark gray gray

Boring Terminated at 46 Feet

0.5

6.0

33.5

35.5

46.0

1055.5+/-

1050+/-

1022.5+/-

1020.5+/-

1010+/-

RUN 1

RUN 2

RUN 3

1179000+

(HP)

9000+

(HP)

(HP)

(HP)

(HP)

<500

(HP)

(HP)

(HP)

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

R A

T E

D F

R O

M O

R

IG

IN

A

L R

E P

O R

T . G

E O

S M

A R

T L

O G

-N O

W E

LL

K

IC

K A

P O

O B

R

ID

G E

R .G

P J

T E

R R

A C

O N

_D A

T A

T E

M P

LA

T

E .G

D T

/2

/2

D E

P T

H

F t.)

W A

T E

R L

E V

E L

O B

S E

R V

A T

IO

N

S

F

IE

LD

T

E S

T R

E S

U

LT

S

W A

T E

R C

O N

T E

N T

)LOCATION See Exploration Plan

Latitude: 39.7108° Longitude: -95.6456°

G R

A P

H

IC

L O

G

M O

D E

L

LA

Y E

R

DEPTH

Approximate Surface Elev.: 1056 (Ft.) +/-

ELEVATION (Ft.)

Advancement Method:

Hollow Stem Auger to 34 NX Core to termination

Abandonment Method:

Boring backfilled with Auger Cuttings and/or Bentonite

Notes:

Project No.: 14225103

Drill Rig: ATV

BORING LOG NO. B-1

Kickapoo Tribe in KansasCLIENT:

Horton, KS

Driller: LN

Boring Completed: 02-22-2023

PROJECT: Kickapoo Bridge B119 Replacement

Elevations were estimated from provided plans.

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

140th Street over tributary to Delaware River Horton, KS

SITE:

Boring Started: 02-22-2023

2016 SW 37th St Topeka, KS

WATER LEVEL OBSERVATIONS

No free water observed prior to the introduction of drilling fluids

R E

C O

V E

R Y

In

S A

M P

LE

N

U M

B E

R

D R

Y U

N

IT

W E

IG

H

T pc f)

LA

B

O R

A T

O R

Y H

P ps f)

U N

C O

N F

IN

E

D C

O M

P R

E S

S

IV

E S

T R

E N

G T

H ps f)

S A

M P

LE

T

Y P

E

5-8-10 N=18

1-2-2 N=4 2-2-2 N=4

2-2-2 N=4

0-1-2 N=3

2-2-3 N=5

2-3-6 N=9

16-36-48 N=84

28-50/4"

20-50/5"

16.4

15.0

24.9

17.9

27.0

30.1

27.6

30.1

15.6

18.6

16.7

12 INCHES AGGREGATE

LEAN TO FAT CLAY (CL/CH), trace gravel, dark gray, very stiff, (Possible Fill) LEAN CLAY (CL), trace sand and gravel, dark gray, medium stiff to stiff

SILTY CLAY (CL-ML), grayish tan, soft to medium stiff

LEAN TO FAT CLAY (CL/CH), trace sand, gray, stiff

SHALE, gray, moderate weathering

Boring Terminated at 44.4 Feet

1.0

3.0

14.0

28.0

32.0

44.4

1053.5+/-

1051.5+/-

1040.5+/-

1026.5+/-

1022.5+/-

1010.1+/-

9000+

(HP)

9000+

(HP)

(HP)

(HP)

(HP)

<500

(HP)

(HP)

9000+

(HP)

(HP)

9000+

(HP)

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

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IF

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P A

R A

T E

D F

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IN

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-N O

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/2

/2

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F t.)

W A

T E

R L

E V

E L

O B

S E

R V

A T

IO

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S

F

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LD

T

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T R

E S

U

LT

S

W A

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O N

T E

N T

)LOCATION See Exploration Plan

Latitude: 39.7108° Longitude: -95.6452°

G R

A P

H

IC

L O

G

M O

D E

L

LA

Y E

R

DEPTH

Approximate Surface Elev.: 1054.5 (Ft.) +/-

ELEVATION (Ft.)

Advancement Method:

Hollow Stem Auger

Abandonment Method:

Boring backfilled with Auger Cuttings and/or Bentonite

Notes:

Project No.: 14225103

Drill Rig: ATV

BORING LOG NO. B-2

Kickapoo Tribe in KansasCLIENT:

Horton, KS

Driller: LN

Boring Completed: 02-21-2023

PROJECT: Kickapoo Bridge B119 Replacement

Elevations were estimated from provided plans.

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

140th Street over tributary to Delaware River Horton, KS

SITE:

Boring Started: 02-21-2023

2016 SW 37th St Topeka, KS

28 ft while drilling

WATER LEVEL OBSERVATIONS

R E

C O

V E

R Y

In

S A

M P

LE

N

U M

B E

R

D R

Y U

N

IT

W E

IG

H

T pc f)

LA

B

O R

A T

O R

Y H

P ps f)

U N

C O

N F

IN

E

D C

O M

P R

E S

S

IV

E S

T R

E N

G T

H ps f)

S A

M P

LE

T

Y P

E

1,010

1,015

1,020

1,025

1,030

1,035

1,040

1,045

1,050

1,055

E L

E V

A T

IO

N

M

S L

(f ee t)

Kickapoo Bridge B119 Replacement Horton, KS Terracon Project No. 14225103

Layering shown on this figure has been developed by the geotechnical engineer for purposes of modeling the subsurface conditions as required for the subsequent geotechnical engineering for this project.

Numbers adjacent to soil column indicate depth below ground surface.

NOTES:

B-1 B-2

GEOMODEL

This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions.

First Water Observation

The groundwater levels shown are representative of the date and time of our exploration. Significant changes are possible over time.

Water levels shown are as measured during and/or after drilling. In some cases, boring advancement methods mask the presence/absence of groundwater. See individual logs for details.

Lean, Lean to Fat, and Silty Clays, varying amounts of silt, sand, and gravel, soft to stiff.3

Limestone and Shale.4

LEGEND

Aggregate Base Course

Fill

Lean Clay/Fat Clay

Limestone

Shale

Lean Clay

Silty Clay

Model Layer General DescriptionLayer Name

Asphalt and Aggregate1

Lean to Fat Clay, trace silt, sand, gravel, concrete fragments, and organics.2

Cohesive Soil

Bedrock

Surface

Fill

0.5

33.5

44.4 masnapp Line masnapp Callout Approximate elevation of channel

ROCK CORE PHOTO LOG

Photo #1: Boring SB-1: Run 1 (34.5’ to 36’), Run 2 (36’ to 41’), and Run 3 (41’ to 44’)

Photo #2: Boring SB-1: Run 4 (44.5’ to 46’)

SUPPORTING INFORMATION

General Notes

Unified Soil Classification System

Description of Rock Properties

GENERAL NOTES – DESCRIPTION OF SYMBOLS AND ABBREVIATIONS

GENERAL NOTES

Sampling Water Level Field Tests

Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated. Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible with short term water level observations.

N Standard Penetration Test Resistance (Blows/Ft.)

(HP) Hand Penetrometer

(T) Torvane

(DCP) Dynamic Cone Penetrometer

UC Unconfined Compressive Strength

(PID) Photo-Ionization Detector

(OVA) Organic Vapor Analyzer

Descriptive Soil Classification

Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their dry weigh t retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency.

Location and Elevation Notes

Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracy of such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area.

Strength Terms

Relative Density of Coarse Grained Soils

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

Density determined by Standard Penetration Resistance

Consistency of Fine Grained Soils

(50% or more passing the No. 200 sieve.)

Consistency determined by laboratory shear strength testing, field visual-manual procedures or standard penetration resistance

Descriptive Term (Density)

Standard Penetration or N-Value

Blows/Ft.

Descriptive Term (Consistency)

Unconfined Compressive Strength Qu (psf)

Standard Penetration or N-Value

Blows/Ft.

Very Loose 0 – 3 Very Soft less than 500 0 – 1

Loose 4 – 9 Soft 500 to 1,000 2 – 4

Medium Dense 10 – 29 Medium Stiff 1,000 to 2,000 4 – 8

Dense 30 – 50 Stiff 2,000 to 4,000 8 – 15

Very Dense > 50 Very Stiff 4,000 to 8,000 15 – 30

Hard > 8,000 > 30

Relative Proportions of Sand and Gravel Relative Proportions of Fines

Descriptive Term(s) of other constituents

Percent of Dry Weight

Descriptive Term(s) of other constituents Percent of Dry Weight

Trace < 15 Trace < 5

With 15 – 29 With 5 – 12

Modifier > 30 Modifier > 12

Grain Size Terminology Plasticity Description

Major Component of Sample Particle Size Term Plasticity Index

Boulder Over 12 in. (300 mm) Non-plastic 0

Cobbles 12 in. to 3 in. (300 mm to 75 mm) Low 1 – 10

Gravel 3 in. to #4 sieve (4.75mm to 0.075mm) Medium 11 – 30

Sand #4 to #200 sieve (4.75mm to 0.075mm) High > 30

Silt or Clay Passing #200 sieve (0.075 mm)

UNIFIED SOIL CLASSIFICATION SYSTEM

UNIFIED SOI L CLASSI FICATI ON SYSTEM

Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A Soil Classification

Group

Symbol Group Name B

Coarse-Grained Soils:

More than 50% retained on No. 200 sieve

Gravels:

More than 50% of coarse fraction retained on No. 4 sieve

Clean Gravels:

Less than 5% fines C

Cu 4 and 1 Cc 3 E GW Well-graded gravel F

Cu 4 and/or [Cc<1 or Cc>3.0] E GP Poorly graded gravel F

Gravels with Fines:

More than 12% fines C

Fines classify as ML or MH GM Silty gravel F, G, H

Fines classify as CL or CH GC Clayey gravel F, G, H

Sands:

50% or more of coarse fraction passes No. 4 sieve

Clean Sands:

Less than 5% fines D

Cu 6 and 1 Cc 3 E SW Well-graded sand I

Cu 6 and/or [Cc<1 or Cc>3.0] E SP Poorly graded sand I

Sands with Fines:

More than 12% fines D

Fines classify as ML or MH SM Silty sand G, H, I

Fines classify as CL or CH SC Clayey sand G, H, I

Fine-Grained Soils:

50% or more passes the

No. 200 sieve

Silts and Clays:

Liquid limit less than 50

Inorganic:

PI 7 and plots on or above “A” line J

CL Lean clay K, L, M

PI 4 or plots below “A” line J ML Silt K, L, M

Organic:

Liquid limit - oven dried

0.75 OL

Organic clay K, L, M, N

Liquid limit - not dried Organic silt K, L, M, O

Silts and Clays:

Liquid limit 50 or more

Inorganic:

PI plots on or above “A” line CH Fat clay K, L, M

PI plots below “A” line MH Elastic Silt K, L, M

Organic:

Liquid limit - oven dried

0.75 OH

Organic clay K, L, M, P

Liquid limit - not dried Organic silt K, L, M, Q

Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat

A Based on the material passing the 3-inch (75-mm) sieve.

B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name.

C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay.

D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay.

E Cu = D60/D10 Cc =

F If soil contains 15% sand, add “with sand” to group name.

G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.

H If fines are organic, add “with organic fines” to group name.

I If soil contains 15% gravel, add “with gravel” to group name.

J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.

K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant.

L If soil contains 30% plus No. 200 predominantly sand, add

“sandy” to group name.

M If soil contains 30% plus No. 200, predominantly gravel, add

“gravelly” to group name.

N PI 4 and plots on or above “A” line.

O PI 4 or plots below “A” line.

P PI plots on or above “A” line.

Q PI plots below “A” line.

DxD

)(D

DESCRIPTION OF ROCK PROPERTIES

ROCK VERSION 2

Weathering

Fresh Rock fresh, crystals bright, few joints may show slight staining. Rock rings under hammer if crystalline.

Very slight Rock generally fresh, joints stained, some joints may show thin clay coatings, crystals in broken face show bright.

Rock rings under hammer if crystalline.

Slight Rock generally fresh, joints stained, and discoloration extends into…