Amendment 1- 230478-000 Emergency Power Dole VA Revision No. 1_S.pdf

CONSTRUCTION | SURVEY | GEOTECHNICAL DIVISIONS LOCATED AT: 350 SOUTH WASHINGTON WICHITA, KS 67202 316-262-6457 FAX 316-262-6592

MAILING ADDRESS: 303 SOUTH TOPEKA WICHITA, KS 67202 www.pec1.com

Geotechnical Engineering Report

Construct Emergency Power System – Dole VA Wichita, Kansas

PREPARED FOR

Miller-Remick, LLC

Cherry Hill, New Jersy

PEC PROJECT NO.

230478-000

PREPARED BY

Emmett M. Foltz, EIT

REVIEWED BY

Britt D. Clubb, PE License No. 24123

DATE

March 24, 2026

Construct Emergency Power System – Dole VAContents | i

Table of Contents

1. INTRODUCTION

1.1 General

1.2 Site Location and Description

1.3 Project Description

2. SUBSURFACE CONDITIONS

2.1 Boring Profiles

2.2 Existing Fill Materials

2.3 Groundwater

2.4 Seismic Classification

3. GEOTECHNICAL RECOMMENDATIONS & CONCLUSIONS

3.1 General

3.2 Geotechnical Discussion

4. EARTHWORK

4.1 Site Preparaton

4.2 Material Types

4.3 Utility Trenches

4.4 Site Grading and Drainage

4.5 Excavations

5. FOUNDATION RECOMMENDATIONS

5.1 General

5.2 Modulus of Subgrade Reaction

5.3 Deep Foundation Recommendations

6. CONCRETE SLAB-ON-GRADE

6.1 Building Pad and Subgrade Preparation

6.2 Low Volume Change Material

6.3 Building Pad and Slab-on-Grade Construction Considerations

7. LATERAL EARTH PRESSURES

Granular Backfill Materials (Sand) (Moist Unit Weight = 115 pcf)

In-Situ Shale Soils (Moist Unit Weight = 125 pcf)

Construct Emergency Power System – Dole VAContents | ii

8. PAVEMENTS

8.1 Non-Motorized Vehicle Pavement

8.2 Motorized Vehicle Pavement – Light to Moderate

8.3 Chemically Stabilized Soil

9. QUALITY CONTROL TESTING

10. REPORT SUMMARY

11. GENERAL NOTES AND LIMITATIONS

FIGURES: Site and Boring Locations

APPENDIX A: Field Exploration Program

APPENDIX B: Laboratory Testing Program

APPENDIX C: LPILE Parameters

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1. INTRODUCTION

1.1 GENERAL

This report serves as the conclusion to the subsurface investigation for the Construct Emergency Power System – Dole VA located in Wichita, Kansas. Four (4) geotechnical borings were performed within the footprint of the structure/structures and associated parking areas. The borings are designated SB-1 through SB-4 and were drilled to a depth of approximately 32 to 42 feet from existing ground elevation. Boring logs and boring location diagrams can be found in the attached Appendix of this report. The purpose of this report is to address specific geotechnical recommendations for building structures and pavements.

The geotechnical study included a field exploration program to obtain information on the subsurface conditions and collect samples for laboratory testing. The samples obtained during the field exploration were visually observed and classified in the laboratory referencing ASTM procedures. Representative samples were selected for laboratory testing to determine physical and engineering characteristics of the in-situ soils. Field exploration and laboratory test results were analyzed to develop geotechnical recommendations for the proposed construction.

The following sections present the results of field exploration, laboratory tests, and our conclusions and recommendations for the project design. The conclusions and recommendations are based on the project information available at the time of this report and the subsurface conditions encountered in the boreholes at the locations and times indicated. If the project details including structure locations, elevations, loads, cut and fill depths or other conditions change during design or if the subsurface conditions vary from those described in this report, the conclusions and recommendations may need to be re-evaluated and adjusted.

The scope of services did not include an environment assessment for determining the presence or absence of wetlands, or hazardous or toxic subsurface materials, groundwater or air, on, below or around this site.

Statements in this report or in the boring logs which reference visual, odorous, or other unusual or suspicious items or conditions are limited and should be used for information purposes only.

1.2 SITE LOCATION AND DESCRIPTION

This site is located at 5500 E Kellog Ave in Wichita, Kansas. The current site contains existing structures planned for demolition. The current ground cover consists of asphalt and concrete pavement. Based on visual observations the site appears to be relatively level.

1.3 PROJECT DESCRIPTION

It is our understanding that proposed construction will include a new structure to assist with emergency power at Rober J. Dole VA Medical Center in Wichita, Kansas. It is our understanding that the project will also include two new underground fuel tanks, approximately 47.5 ft in length installed at a minimum depth of approximately 15 feet below ground elevations. We anticipate that finish floor elevations of the additions to the existing structure will match the existing finish floor elevations of nearby structures. Additionally, new drive/pavement areas are planned for construction. It is our understanding the maximum loading for walls and columns of 3 klf and 150 kips respectively. If our assumptions are incorrect, PEC should be notified immediately so that our recommendations can be amended.

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2. SUBSURFACE CONDITIONS

2.1 BORING PROFILES

Based on the results of the borings, the subsurface conditions on the project site can be generalized as decomposed shale increasing with stiffness to boring termination depth. These soils were typically in a moist condition with a stiff to very stiff consistency. For more information pertaining to the borings, please refer to Appendix A.

2.2 EXISTING FILL MATERIALS

Fill materials were encountered at the boring locations extending from the ground surface or below top of existing pavement to depths ranging from approximately 2 to 3 feet below existing site grade at borings SB-2, SB-3 and SB-4 The fills soils primarily consisted of lean to fat clay and gravel. See the attached boring logs and laboratory summary sheet for physical properties of the fill materials.

Due to previous grading and construction operations at the site, disturbed soils and/or fill materials are likely to be encountered at other areas of the site that were not explored during our fieldwork. To our knowledge, test reports indicating the percent compaction and moisture content of these fill materials are not available.

PEC Field Services considers these fill materials as undocumented and uncontrolled fill and should be removed from directly beneath foundations as described in the section Shallow Foundations. Due to the depths at which fill materials were encountered, it is anticipated that portions of the structure may be founded on the encountered fill soils. If during construction operations, undocumented fill materials are encountered below bearing depth, these soils can present a significant risk if not removed prior to construction and replaced with engineered placed in a controlled manner. The fill materials encountered appear suitable for re-use as new engineered fill, provided they are placed in accordance with section Compaction Requirements of this report.

2.3 GROUNDWATER

Ground water was observed between 13.0 and 26.0 feet below existing grade during drilling operations.

Fluctuations of groundwater levels can occur due to seasonal variations in the amounts of rainfall, run off, nearby creek/river water level (if present), and other factors not evident at the time the borings were performed. The possibility of perched water and/or fluctuation of groundwater conditions should be considered for developing construction documents for this project.

Uplift forces acting on below-grade tanks due to groundwater can be resisted by the weight of the overlying soil. For design purposes, it is appropriate to assume a unit weight of 120 pcf for the on-site soil above the water table.

2.4 SEISMIC CLASSIFICATION

The native soil profiles encountered at the site consist primarily of stiff to very stiff decomposed shale. IBC 2015 determines the seismic hazard for a site based upon 2008 mapping of bedrock accelerations prepared by the United States Geologic Survey (USGS) and the soil site class. The USGS values are presented on maps incorporated into the IBC code and are also available based on latitude and longitude coordinates (grid points). For site class definitions, IBC 2015 (Section 1613.3.2) refers to Chapter 20, Site Classification Procedure for Seismic Design, of American Society of Civil Engineers (ASCE) 7. Given the subsurface soils at the site, including our projection of soils within the upper 100 feet of the soil profile, it is our opinion the site best fits Site Class D – Stiff Soil Profile, which we recommend for seismic structural design.

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3. GEOTECHNICAL RECOMMENDATIONS & CONCLUSIONS

3.1 GENERAL

Our Geotechnical Engineering evaluation of the surface and subsurface conditions at the site, with respect to the planned construction, are based on (1) our site observations, (2) the field and laboratory test data obtained, and (3) our understanding of the project information and structural conditions as presented previously in this report.

If the project information is incorrect, or should the location of the structure change, please contact the undersigned Engineer so that these recommendations can be reviewed. If project details including structure, and parking/drive locations, elevations, cut and fill depths or other conditions change during design or if the subsurface conditions vary considerably from those described in this report, the conclusions and recommendations shall not be considered valid until they have been re-evaluated.

The recommendations presented in the subsequent sections of this report present design and construction techniques that are appropriate for the planned construction. We recommend that we be provided with the opportunity to review the foundation plans and earthwork specifications to verify that our recommendations have been properly interpreted and implemented.

3.2 GEOTECHNICAL DISCUSSION

The near-surface soils at this site are typically moderate to high plasticity shales in a relatively moist condition. If the moderate to high plasticity shales are dry at the start of, or during construction, they could undergo post-construction swell when subjected to increased moisture conditions. Based on the results of our field exploration, laboratory testing, and the anticipated final site grades, we consider the subsurface conditions at the site adaptable for support of the new structures when constructed on a properly designed foundation system consisting of shallow spread footings, drill piers, or concrete mat foundation, placed on engineered fill or native materials.

Expansive shale soils are also present at this site and should not be used directly beneath concrete slabs.

See section Earthwork more detail regarding material types and uses for this project. Expansive soils pose a risk to slab heave or settlement with an increase or decrease in moisture. Recommendations in this report are to help mitigate the effects of soil shrinkage and expansion. While following these recommendations during construction will help reduce shrink/swell effects, some movement and cracking should be anticipated. The severity of cracking and uneven slab elevations will most likely increase if any construction operations result in the excessive wetting or drying of the expansive soils. Completely eliminating the risk of movement may not be feasible, but it may be possible to further reduce the risk of movement through other costlier construction measures. These measures could include increasing the zone of Low Volume Change material and/or construction a structural slab designed against swell and or shrinkage of the underlying subgrade soils. The design of a structural slab is not a part of our scope of services. We could discuss this alternative at your request.

This site was developed prior to this project. We are unaware if previous structures, including basements, or to what extent below grade elements were removed. These existing elements will most likely be encountered during construction operations. Care should be taken to ensure their complete removal prior to the start of any new construction. We consider these items unsuitable for support of new structures, including pavements, foundations and floor slabs, and should be removed and replaced in accordance with section Earthwork.

As mentioned above, existing fill was encountered and logged in several of our borings. We were not provided with any documentation suggesting that the existing fill materials were placed and a controlled manner. If left in place, the existing fill materials can cause the foundations and floor slab to perform

| 6 unpredictably. The depth of the existing fill ranged from 2 to 3 feet below existing grade within borings SB- 2, SB-3 and SB-4. The extents of the existing fill will not be fully known until earthwork and grading operations begin. We recommend that the owner and/or owner’s agent establish a known elevation for removal of the existing fill for bid purposes. Additionally, the owner should request unit rates for over-excavation beyond the base bid quantities, and for exporting and importing new engineered fill. Increase in costs should be accounted for associated with moisture conditioning and rework of soils deemed unsuitable during construction materials testing and observations.

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4. EARTHWORK

4.1 SITE PREPARATON

Prior to the start of construction, we recommended removing the existing topsoil, existing fill (if any) and all other unsuitable soils from within and at least 5 feet beyond the proposed building areas. All existing fills or unsuitable soils present beneath the bearing elevation of the footings should be removed. Existing fill left in place beneath footings could cause excessive settlement of the foundation system beyond what is typically acceptable. Existing fill and/or native soils not meeting the Plasticity Index requirements for Low Volume Change Material (LVC), see section Material Types below, should be removed to a depth of at least 30 inches below the bottom of the design floor slab elevation. After completion of the over-excavation operations, we recommend that the exposed subgrade be thoroughly proof-rolled, using heavy construction equipment (under the direction of PEC Field Services personnel) to identify any soft, yielding or unsuitable soils still present after the completion of over-excavation operations. The equipment used to perform the proofroll should consist of a rubber-tired vehicle weighing at least 15 tons (dump truck, water truck) or equivalent. If soft, yielding or unsuitable soils are identified during proof-rolling operations, we recommend that these soils be removed and replaced or reworked and re-compacted in place to meet the recommendations for engineered fill as presented in section Material Types.

4.2 MATERIAL TYPES

Engineered fill should meet the following physical property requirements:

LOCATION SOIL TYPE1 MIN. MOISTURE CONTENT COMPACTION RANGE

Below Footing Bearing Elevation2

Native Soils Optimum to +4% 98% to 100%

New Engineered Fill

PI >15

Optimum to +4% 98% to 100%

PI < 15

±3% of Optimum 98% to 100%

Below LVC Zone, Above Footing Bearing Native Soils Optimum to +4% 95% to 100%

Optimum to +4% 95% to 100%

±3% of Optimum 95% to 100%

Low Volume Change Zone

New Engineered Fill

5 < PI > 15

±3% of Optimum 95% to 100%

Granular Material Workable Moisture Content 95% to 100%

Pavement Subgrade Native Soils Optimum to +4% 95% to 100%

Optimum to +4% 95% to 100%

±3% of Optimum 95% to 100%

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Pavement Subgrade:

Upper 9 inches

Native Soils Optimum to +4% 98% to 100%

±3% of Optimum 98% to 100%

Pavement Subbase Chemically

Stabilized Soils3

Granular Material4 Workable Moisture Content 98% to 100%

1. Fill materials should be free of organic matter and debris. Frozen fill materials should not be used and should not be placed on frozen subgrade. Samples of all material types used during construction should be submitted to PEC for evaluation

2. Engineered fill beneath footings should have liquid limit of less than 40 and plasticity index less than 25

3. See section Chemically Stabilized Soils

4. See section Motorized Vehicle Pavements

4.3 UTILITY TRENCHES

Utility trench backfill is a potential source for the migration of water into and beneath structural elements, including foundations and floor slabs. Proper backfilling operations are imperative to reduce increases in moisture to the bearing and floor slab subgrade soils. Utility trenches that enter the building footprint should be sealed using a trench plug consisting of clay soils or flowable fill. If clay material is chosen for use as the trench plug, the material should be placed in accordance with the recommendations provided in section Material Types.

4.4 SITE GRADING AND DRAINAGE

Ponded water can present significant problems during and after construction. Site grading plans should be designed to provide positive drainage away from all structures, slabs-on-grade, pavements and sidewalks.

A minimum slope of 5 percent for the first 10 feet next to the structure and 2 percent thereafter is recommended for landscape areas. Positive drainage should also be provided in all paved and sidewalk areas to the extent practicable within ADA requirements. All downspouts should be designed to discharge a minimum of 5 feet away from structures. Temporary drainage to a sump should be used to remove ponded water in excavations.

The building pad should also be graded to promote positive runoff from weather events. Water should not be allowed to pond on the building pad and soak into the subgrade soils. Measures should be taken to remove ponded water and to maintain the moisture content of building pad and pavement subgrade soils during construction. If subgrade soils become frozen, saturated, desiccated, and/or disturbed, the subgrade soils should be removed and replaced with suitable soils or scarified, re-worked, and compacted in-place, prior to the placement of concrete for floor slabs or pavements.

4.5 EXCAVATIONS

Excavation should be performed in accordance with OSHA 29 CFR, Part 1926, Subpart P, “Excavations” and all its appendices. Each excavation must be evaluated during construction by the responsible person to determine appropriate sloping, shoring and excavation techniques. Maximum OSHA recommended slopes for temporary excavations less than 20 feet deep with simple slopes including the following:

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• Stable Rock – Vertical Side Walls

• Type A (stiff soils) – ¾ H to 1 V

• Type B (medium stiff soils) – 1 H to 1 V

• Type C (soft soils/sands) – 1.5 H to 1 V

These classifications are presented for general information only and preliminary design only. OSHA and pertinent local, state and federal regulations should be reviewed for details regarding soil strengths, sloping/shoring requirements and other guidelines. The soils on this site have been classified as Type B soils.

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5. FOUNDATION RECOMMENDATIONS

The table below outlines our recommendations for construction of shallow foundation systems founded on native and/or engineered fill materials:

LOCATION COLUMN WALL

BELOW GRADE

TANK

Net Allowable Bearing Pressure on Native Soil and/or Engineered Fill1,2

• Maximum Column Load:

150 kips

• Maximum Wall Load: 3 klf

2000 psf 2000 psf 2500 psf

Minimum Footing Width 30 inches 16 inches --

Minimum Footing Depth3 36 inches 36 inches --

Estimated Total Settlement4 ≤ 1 inch ≤ 1 inch ≤ 1.3 inches

Estimated Differential Settlement4 < ¾ inch < ¾ inch < 0.8 inch

1. All new engineered fill placed beneath footings should be constructed as recommended in the Earthwork section of this report. For footings founded on Engineered Fill, at a minimum, 24 inches of engineered fill is required beneath the footings.

2. Assumes all unsuitable fill, soft, or deleterious materials have been removed to native materials and replaced with new engineered fill placed in accordance with the recommendations outlined in this report

3. Indicates depth below finish floor elevation

4. Foundation settlements are based on the maximum estimated loads. If loading to the structure exceeds these estimated loads, additional settlement analysis will be required.

Differential settlement between existing and proposed structures could equal the total settlement.

5.1 GENERAL

Prior to placement of concrete, foundation excavations should be clear of standing water and loose bearing materials. To avoid disturbance of the bearing soils, concrete should be placed as soon as practicable.

The contractor should take measures to limit exposure of the subgrade soils to excessive wetting or drying.

Precautions should be made to prevent bearing soils from becoming frozen during cold-weather construction. To reduce the effects of below-freezing temperatures on exposed bearing soils, a layer of loose soil could be placed within the excavation if there is a somewhat short duration between the excavation and the placement of concrete. If an extended amount of time prior to the placement of concrete is needed, a mud-mat should be considered.

Under typical construction schedules, the bearing soils are suitable for support of the design bearing pressure and will be present at the base of the footings. However, there are factors that could cause suitable bearing materials to become unsuitable, such as, weather, perched water, and the presence of

| 11 undocumented existing fill materials. These factors could cause isolated areas of the bearing material to require the implementation of a removal and replacement program. Because of such, we recommend that PEC Field Services be present to evaluate the foundation bearing materials prior to the placement of concrete.

If during the evaluation of the bearing materials, soft, unsuitable material is encountered, the excavation should be extended down through the unsuitable zone to suitable bearing materials. The footings could bear directly on the newly exposed bearing materials or on lean concrete backfill. As an alternative to deepening the footings or backfill with lean concrete, the footings could be backfilled with newly placed engineered fill placed in accordance with section Material Types. If this method is selected, the footings should be over-excavated and should extend laterally at least 8 inches beyond the edges of the footings for every 1-foot in excavation depth. The engineered fill materials used should meet the requirements of Lean Clay or Low Volume Change material as defined in section Material Types.

5.2 MODULUS OF SUBGRADE REACTION

The Modulus of Subgrade Reaction (Ks), is based on soil index properties obtained from both field and laboratory analysis.

The Modulus of Subgrade Reaction is based on the following equations:

Ks = q / Δ q = load per unit area

Δ = settlement

Based on our evaluation and analysis, using an estimated Modulus of Subgrade Reaction (Ks) of 100 pounds per cubic inch (pci) and Poisson’s ratio of 0.33 would be appropriate for slabs bearing on LVC type material.

5.3 DEEP FOUNDATION RECOMMENDATIONS

It is our understanding that portions of the project may be founded on a drilled pier or auger cast-in-place (ACIP)foundation system. The recommendations given below provide for design and construction techniques that are appropriate for the planned construction. Pier/Pile loads should be designed using the nominal geotechnical resistances for the given tip elevation depths shown in appendix C. The

| 12 allowable drilled shaft, ACIP capacity values in appendix C were developed based on our site investigation, in accordance with the U.S. Department of Transportation Federal Highway Administration:

Publication No. FHWA-NHI-10-016. utilizing a 2.5 factor of safety for skin friction values and 3.0 factor of safety for end bearing values. All piers/piles should have a minimum embedment depth of at least 5 times the pier/pile diameter.

Drilled piers resist uplift loads by the effective dead weight of the pier/pile plus two-thirds the recommended skin friction value given in the section above. Skin friction should be ignored in the upper 5 feet of pier/pile, or any portion of the shaft which is cased.

To aid in the potential dewatering of the drilled shafts, we recommend a minimum shaft diameter of 36 inches. Deep foundations should be installed at a minimum center-to-center spacing of at least 3 diameters for full axial capacities and 5 diameters for full lateral capacities. At these spacings, no reduction in single shaft capacity (axial or lateral) is needed. Adjacent drilled shafts should not be installed on the same day. During installation of the drilled shaft foundations, the excavation and placement of concrete should be observed by an experienced engineering technician, under the supervision of licensed geotechnical engineer.

Based on the water level readings observed in all the borings, we anticipate that all excavations will be wet. Care should be taken to avoid aggressive dewatering of the shaft excavations as it may cause heaving and/or boiling. Prior to placing concrete and the reinforcing steel, groundwater should be allowed to stabilize to its hydrostatic level. The owner should provide a line item during the bidding process to account for dewatering equipment and temporary casings.

Expansive soils are present at the site. To address potential swelling of soil, it is recommended to install void forms with a minimum height of 4 inches beneath grade beams between piers. Suitable options include paper-based box forms or collapsible equivalents. Removal of soil 30 inches below grade beams and replacing with LVC material placed in accordance with section Material Types, is a suitable alternative to void forms beneath grade beams.

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6. CONCRETE SLAB-ON-GRADE

6.1 BUILDING PAD AND SUBGRADE PREPARATION

Floor slab performance is generally affected by swelling of the underlying subgrade soils due fluctuations in moisture content. The moisture content of the subgrade soils can increase due to trapped, accumulated capillary moisture which would normally escape or evaporate if concrete floors slabs are not constructed.

The plasticity and in-situ moisture content of the subgrade soils is directly correlated to the soil’s swell potential. Swell potential of the soils is also affected by the confining pressure of the floor slab itself and the overburden pressure of the fill materials used to develop the designed grade elevation.

Based on the subsurface conditions encountered at the time of our borings, the subgrade soils are identified as having moderate to high plasticity and were observed to be relatively moist. The laboratory test data, as well as our observations indicate that the near-surface subgrade soils have the potential to swell which could cause vertical movement (or heave) of the floor slab. The swell potential of the subgrade soils could increase should the soils be allowed to dry during construction operations. Based on laboratory test results and our familiarity of the soils, and using analysis that considers the materials physical properties obtained from laboratory testing, we estimate the potential vertical rise (PVR) of the subgrade soils to be approximately 1-inch or less.

To reduce the amount of PVR, we recommend a minimum total of 30 inches of low volume change (LVC) material be placed below all at grade floor slabs to reduce the potential for heave of the near-surface soils and provide a homogenous base. LVC material is described in further detail in the section below. Lower portions of the fill soils below the LVC zone may consist of on-site soils, imported general fill or LVC, provide the fill materials are installed as described in section Material Types.

In addition to the LVC zone, we recommend a minimum of 4 inches of a granular leveling course be placed directly below the at-grade floor slabs. The leveling course should consist of clean, medium to coarse grained sand, or clean gravel/rock with less than 5 percent fines. An appropriate synthetic moisture barrier should also be used for moisture sensitive floor coverings as recommended by the floor covering manufacturer. Care should be taken to protect the vapor barrier materials from puncture and tearing during construction operations. See Building Pad Diagram below:

The above recommendations provide for a stabilized/moisture-conditioned zone below the floor slab.

These recommendations are intended to reduce the potential for floor slab movement due to swell or shrinkage of the in-situ soils without adding undue costs to the project. However, some differential movement may still occur between floor slabs and foundations due to shrink/swell of the in-situ soils or differential settlement between the foundations and the floor slabs. The potential for damage due to relative differential movement between the footings and floor slab may be reduced by isolating the floor slab from all bearing walls and columns to allow unrestrained vertical movement and to restrict load transfer to and from the structure.

These recommendations do not necessarily address the potential for significant differential movement due to extreme moisture changes caused by excessive drying or saturation of the subgrade soils. Causes for excessive moisture changes can include leaking utility lines, poor surface or subsurface drainage, inadequate sealing of joints, and others. If project design includes items which can contribute to excessive moisture changes in the subsurface soils, our recommendations may need to be re-evaluated and adjusted, and additional preventative measures may be required.

6.2 LOW VOLUME CHANGE MATERIAL

We define LVC materials as any material having a liquid limit (LL) of less than 40 and a plasticity index (PI) of at least 5, but no more than 15. Clayey sands, silty/sands, lean clays and granular materials such as, KDOT Type AB-3 crushed concrete, or crushed limestone, or crushed limestone screenings, typically meet

| 14 our definition of LVC materials. Cohesive soils identified for use as LVC materials should be tested in a laboratory prior to bidding and/or construction, to verify the materials suitability for LVC material. If cohesive LVC materials are selected for use, it is imperative that continued monitoring of the moisture content of these soils be done by the contractor to ensure excessive drying or wetting does not occur prior to the placement of the concrete floor slab. Cohesive LVC soils are susceptible to swell if allowed to dry. We recommend that within 48 hours of planned placement of concrete floors slabs, the LVC be tested for compaction and moisture content. If compaction and moisture content do not meet the project requirements, the subgrade soils should scarified, moisture conditioned and re-compacted as described in section Material Types.

If LVC material is not readily available, either onsite or off-site, the onsite soils may be chemically modified to achieve LVC like material using hydrated lime, Class C fly ash, cement kiln dust (CKD), or cement.

These options can cause problems pertaining to dusting during construction. CKD should not be used if the virgin material has a high sulfate content. The chemical reaction between the CKD and the sulfates can cause excessive swelling of the soils after construction. We recommend that laboratory tests of the subgrade soils and a recent chemical laboratory analysis of the CKD be conducted prior to the approval for CKD use.

For cohesive soils, we recommend the following percentage by dry weight, based on our experience:

• Hydrate Lime: 4% to 6%

• Class C Fly Ash: 12% to 15%

• Cement Kiln Dust: 6% to 8%

• Cement (wet or dry): 4% to 7%

The percentage above has shown to reduce the swell/shrink characteristics of cohesive soils; however, a more precise application rate should be developed through a laboratory testing program.

The construction of an LVC zone is critical for overall performance of the concrete floor slab post-construction. However, during construction cohesive LVC soils are prone to become disturbed, dried, and wetted. Because of this, we recommend constructing the upper 4 to 6 inches of the LVC zone with KDOT Type AB-3 crushed limestone or crush concrete. This will provide protection to the cohesive LVC from excessive wetting or drying and provide a stable working surface during construction.

6.3 BUILDING PAD AND SLAB-ON-GRADE CONSTRUCTION CONSIDERATIONS

Site grading is typically started and completed at the early onset of construction. Because of this, subgrade soils can become disturbed as construction progresses. Installation of utilities, construction traffic, and weather events can cause subgrade soils to become unstable or unsuitable for the placement of concrete floor slabs.

Areas that have become disturbed should be evaluated by PEC Field Services prior to the placement of concrete floor slabs. Areas that have become rutted through normal construction operations and fill placement within utility trenches should be thoroughly evaluated, prior to the placement of concrete. If during these evaluations, it is determined that the subgrade soils have become unstable or unsuitable, corrective measures, such as removal and replacement or re-compaction and moisture conditioning of the subgrade soils should take place.

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7. LATERAL EARTH PRESSURES

Underground walls will be subject to lateral earth pressures. Lateral earth pressures are typically estimated by equivalent fluid unit weights. The magnitude of the lateral earth pressure is controlled by many factors including wall design, properties of the in-situ native soils and backfill adjacent to the walls, drainage conditions, surcharge loads and other factors. Where applicable, we generally recommend all below grade structures be designed and constructed using granular backfill and an appropriate drainage system. These measures are recommended to reduce the potential pressures on the below grade walls, the potential for saturation of the soils, and the possible detrimental effects due to shrink/swell of the clay soils. The estimated pressure coefficients and equivalent fluid unit weights are shown in the following tables:

GRANULAR BACKFILL MATERIALS (SAND) (MOIST UNIT WEIGHT = 115 PCF)

Coefficient Equivalent Fluid Unit Weight

Active Pressure 0.27 31

At-Rest Pressure 0.43 49

Passive Pressure 3.69 424

IN-SITU SHALE SOILS (MOIST UNIT WEIGHT = 125 PCF)

Coefficient Equivalent Fluid Unit Weight

Active Pressure 0.42 53

At-Rest Pressure 0.59 74

Passive Pressure 2.37 296

Significantly larger pressures will develop below the groundwater level. Depending on depth of excavation adjacent to the sheet pile retaining wall system, groundwater may be encountered. Sheet pile walls should be designed assuming groundwater will be present at and above the encountered groundwater level. An active equivalent fluid pressure of 77 pcf and an at-rest pressure equivalent fluid pressure of 85 pcf should be used for design of structures with a non-cohesive granular backfill, or in-situ granular backfill that extends below the water level. Other tunnel structures are not anticipated to encounter groundwater, however near surface perched water tables, and water from surface runoff may impact design and require the increase in equivalent fluid pressure noted above.

The passive pressures and coefficient of friction are used to resist sliding and lateral forces. A coefficient of friction of 0.19 is recommended. The at-rest case should be used if the walls are rigid and little or no rotation is anticipated. Below grade walls should only be designed for the active case if walls are allowed to rotate sufficiently to fully mobilize active pressure.

The earth pressure parameters provided above do not include surcharge loads (i.e., structure loads, fill loads, forces from construction equipment). Appropriate safety factors and surcharge loads should be applied to these values. The parameters also do not account for hydrostatic pressures.

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8. PAVEMENTS

8.1 NON-MOTORIZED VEHICLE PAVEMENT

Non-motorized vehicle pavements are defined as exterior concrete pavements not subjected to traffic loads.

Sidewalks, equipment pads, trash compactor pads, etc. are considered non-motorized vehicle pavements and are subject to the following recommendations.

Based on the subsurface conditions encountered at the boring locations, we recommend a minimum of 12 inches of select fill be placed below all at-grade exterior concrete pavement to reduce the potential for heave of the near surface soils and provide a homogenous base. Lower portions of the fill soils below the select fill zones may consist of on-site soils, imported general fill, or LVC materials.

The recommended 12-inch zone of select fill should be comprised of approximately 6 inches of material meeting the requirements for LVC given in the engineered fill section. To promote subgrade storm water drainage and provide a leveling course for construction in addition to the LVC material (as required to meet site grade), we recommend that a minimum of a 6-inch-thick drainage layer/leveling course be placed. The drainage layer may consist of clean, medium to coarse grained sand soils containing less than 5 percent fines (minus # 200), or clean gravel/rock (ASTM C-33, ASTM #57 stone or equivalent) with less than 5 percent fines.

After completing the clearing/stripping operations, the subgrade should be prepared as recommended in Earthwork section of this report. Engineered fill required to achieve the finish grades should be placed and compacted as described in Material Types section of this report.

8.2 MOTORIZED VEHICLE PAVEMENT – LIGHT TO MODERATE

Pavement performance is directly related to the physical properties of the subgrade soils and traffic loading.

Portions of the plant will be subject to lighter traffic loading and a more economical pavement section may be used for design. Design traffic information was not available when preparing this report and was assumed to be light to moderate loads for drive lanes used by passenger vehicles and delivery trucks.

Design traffic information was assumed not to exceed 500,000 ESAL (Equivalent Single Axle Load) for light duty pavement and 1.0 million ESAL for medium duty pavement.

The subgrade soils in the near surface of the site typically consisted of a moderate to high plasticity shale soils. Based on these conditions, we recommend a stabilized subbase (base) be placed below all pavement sections. Prior to placing the stabilized subbase, the existing subgrade should be prepared according to the Earthwork section of this report.

The stabilized subbase (base) beneath the pavement should consist of imported Type AB-1, AB-2, or AB- 3 gravel (or equivalent). We also recommend the placement of a subgrade separation geotextile conforming to AASHTO M288-06, Class 2 be utilized beneath imported gravel to protect it from contamination by the underlying soils and to add strength. As an alternative to an aggregate subbase, the use of cement, either dry or slurry form is also acceptable.

Based on assumed traffic loading, the following typical pavement sections are presented for light and moderately loaded pavements. These sections are typical sections based on assumed pavement loads.

Additional analysis and thicker pavement sections may be needed for heavy traffic and vehicle loads.

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FLEXIBLE PAVEMENT SECTIONS

PAVEMENT SECTION

CAR PARKING/DRIVE

AREAS, LIGHT DUTY

TRUCK DRIVE AREAS

MODERATE DUTY

Wearing Course 2 inches2 2 inches2

Base Course 3 inches2 4 inches2

Stabilized Subbase – Base1,3 8 inches 10 inches

1 Geogrid reinforced compacted Type AB-1, AB-2 or AB-3 gravel, or equivalent

2 Minimum recommended thickness due to construction tolerances 3 Chemically Stabilized Soil

RIGID PAVEMENT SECTIONS

PAVEMENT SECTION

CAR PARKING/DRIVE

AREAS, LIGHT DUTY

TRUCK DRIVE AREAS

MODERATE DUTY

Portland Cement Concrete 5 inches2 6 inches2

Stabilized Subbase – Base1,3 8 inches 8 inches

1 Geogrid reinforced compacted Type AB-1, AB-2 or AB-3 gravel, or equivalent

2 Minimum recommended thickness due to construction tolerances 3 Chemically Stabilized Soil

Rigid pavement is recommended for areas where heavy vehicles will be turning and stopping. These areas include truck routes, security gates, loading and unloading zones, and trash receptacle areas. A minimum of 8 inches of rigid concrete is recommended for these areas.

Asphaltic concrete pavement should consist of a plant mixture composed of aggregate and bituminous material which meets the requirements of KDOT specifications with mix design oversight by a qualified Engineer. Concrete should be based on a mix design prepared by a qualified Engineer.

The pavement sections presented are based on an estimated service life of 20 years. However, periodic maintenance including crack sealing and overlays may be required to achieve the service life. The performance and service life of the pavement will be significantly affected by poor surface and subsurface drainage. Adequate surface drainage and crack sealing should be maintained throughout the life of the pavement.

8.3 CHEMICALLY STABILIZED SOIL

The use of commercially available chemicals to treat the subgrade soils, in-lieu-of aggregate materials is viable option for pavement subgrades. After pavement subgrade elevation has been established, the subgrade soils can be stabilized with hydrated lime, cement kiln dust (CKD), Class C Fly Ash or cement via slurry or dry methods.

For cohesive soils, we recommend the following percentage by dry weight, based on our experience:

• Hydrate Lime: 4% to 6%

• Class C Fly Ash: 12% to 15%

• Cement Kiln Dust: 6% to 8%

• Cement (wet or dry): 4% to 7%

The percentages above have shown to increase the strength characteristics of cohesive soils to those of typical aggregate base materials; however, a more precise application rate should be developed through a laboratory testing program.

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If cement is selected for this application, additional field and laboratory testing are recommended. Prior to stabilizing subgrade soils with cement, a mix design should be performed to ensure appropriate percentages are placed. After placement of cement, the subgrade soils should be thoroughly blended to achieve uniformity and compacted to a minimum of 98 percent of the material’s maximum dry density (by ASTM D-698). Compaction testing should be performed with 24 hours of mixing. The moisture content of the subgrade soils should be within plus or minus 2 percentage points from the material’s optimum moisture content (by ASTM D-698). Cement Treated Base (CTB) materials will perform similarly to low-strength concrete. Shrinkage cracks of the subgrade soils should be expected. These shrinkage cracks, if not controlled, could propagate up through the pavement section and cause a reduction in the useful life of the pavement. To mitigate and control shrinkage cracking of the subgrade, we recommend that the subgrade soils undergo micro-cracking. Micro-cracking is achieved by subjecting the subgrade soils to loading produced from a vibratory smooth-drum roller and dissipates the severity of shrinkage cracking. Within 72 hours of compaction of the CTB, several passes from a vibratory smooth-drum roller should take place to ensure sufficient micro-cracking of the CTB. Base line Modulus of Subgrade Reaction using a lightweight deflectometer to be conducted prior to micro-cracking operations, followed by post-microcracking lightweight deflectometer readings. We recommend performing micro-cracking operations until a 40 percent reduction of the Modulus of Subgrade Reaction is achieved.

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9. QUALITY CONTROL TESTING

We recommend that PFS be retained to perform the construction materials testing and observations required for this project, to verify that our recommendations have been satisfied. Due to our familiarity with the project and the intent of our engineering design, we are the most qualified to efficiently address any problems that may arise during construction.

Proofrolling should be performed within each lift of compacted backfill and fill to verify uniform compaction across the site. A representative number of field in-place density tests should also be made in the upper 2 feet of compacted natural soils, in each lift of compacted backfill and fill, and in the upper 12 inches below the bearing levels in the footing excavations. The density tests are considered necessary to verify that satisfactory compaction operations have been performed. It is recommended that density testing be performed (1) at a minimum of 2 locations within the building area, (2) at one location for every 5 linear feet of continuous wall footings, and (3) within each isolated column pad footing.

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10. REPORT SUMMARY

This section is to provide a short summary of the pertinent information related to site conditions, structural fill, foundation design, and pavement design. The report should be read in its entirety for design purposes as some details may not be included.

• Existing fill materials are present onsite. We recommend that as a baseline for bidding purposes, the upper (2.5) feet of existing subgrade should be removed and stockpiled for use as new engineered fill.

• New engineered fill placed below footing bearing elevation should be compacted to at least 98% and at moisture contents described in the Material Types section of this report.

• New engineered fill placed above the footing bearing elevation should be compacted to at least

95% and at moisture contents described in the Material Types section of this report.

• The upper (2.5) feet of building pad subgrade directly beneath the floor slab should consist of

LVC material. See section Material Types and Low Volume Change Material sections of this report for more detail.

• Footings bearing on native or new engineered fill may be designed using a maximum bearing capacity of 2,000 psf. See section Foundation Recommendations of this report for more detail.

• Flexible Pavements should be designed using a section consisting of 2 inches of surface course, 3 inches of base course overtop 8 inches of subbase in light duty traffic areas. Moderate duty traffic areas should have a section consisting of 2 inches of surface course, 4 inches of base course overtop 10 inches of subbase. See section Pavements of this report for more detail.

• Rigid Pavements should be designed using a section consisting of 5 inches of concrete overtop 8 inches of subbase in light duty traffic areas. Moderate duty traffic areas should have a section consisting of 6 inches of concrete overtop 8 inches of subbase. See section Pavements of this report for more detail.

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11. GENERAL NOTES AND LIMITATIONS

The recommendations presented are based on experience with similar soils in this area. Performance of the structure depends on following the design recommendations and maintenance after construction.

PEC should be retained to review final plan design and specifications. Should the final design plans differ from the information provided to us or from any assumption made to develop this report, PEC should be notified immediately. PEC should also be retained during construction to provide observation and testing services related to earthwork construction and foundation construction.

Geotechnical recommendations are based on periodic sampling in widely spaced, small diameter borings and subsurface conditions may vary from those encountered in the borings. If subsurface conditions are encountered other than described in this report, the recommendations presented may need to be re-evaluated and adjusted.

Our Scope of Services was intended to evaluate the soil conditions within the zone of soil influenced by the foundation system. Our Scope of Services does not address geologic conditions, such as sinkholes or soil conditions existing below the depth of the soil borings. Environmental considerations, such as hazardous material identification, removal, and/or remediation are not a part of our Scope of Service.

This report was prepared for the exclusive use of the client, for the specific project referenced, and in accordance with generally accepted geotechnical engineering practices. No other warrantees or guarantees are intended. The nature and extent of subsurface conditions may vary across the site. Site safety, excavation support, and dewatering requirements are the responsibility of others.

PEC Field Services: Geotechnical Engineering Division

Prepared By: Reviewed By:

Emmett M. Foltz, EIT Britt D. Clubb, PE Geotechnical Engineer SVP Field Engineering

03/24/2026

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FIGURES: Site and Boring Locations

Figure 1. Site Location Map Figure 2. Boring Location Plan

SITE LOCATION MAP

Construct Centralized Emergency Power System - Dole VA

Wichita, Kansas

PEC Project No. 230478-000

Project Area

Figure 1

BORING LOCATION PLAN

Construct Centralized Emergency Power System - Dole VA

Wichita, Kansas

PEC Project No. 230478-000

Plan provided by client for Boring location illustration only.

Not for Construction.

Standard Penetration Test Boring

Approximate Location

No Scale

Figure 2

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APPENDIX A: Field Exploration Program

Coordinates are as shown in Table A-1, Boring Information. The approximate boring locations are shown in Figure 2, Boring Location Plan.

Table A-1. Boring Information

Boring ID Latitude Longitude Depth (ft.)

SB-1 37.6825833 -097.2737556 39

SB-2 37.6825972 -097.2739667 42.5

SB-3 37.6826944 -097.2737750 32.5

SB-4 37.6826750 -097.2740167 36.5

SS

SS

ST

SS

SS

SS

5-12-8 (20)

8-13-16 (29)

9-17-13 (30)

5-6-11 (17)

6-10-14 (24)

53 27 2696

Asphalt approximately 7" thick

DECOMPOSED SHALE, olive/ yellow, very stiff, moist

NOTES

GROUND ELEVATION

LOGGED BY R. Brown

DRILLING METHOD Power Auger

DRILLING CONTRACTOR PEC GROUND WATER LEVELS:

CHECKED BY E. Foltz

DATE STARTED 11/20/25 COMPLETED 11/20/25

AT TIME OF DRILLING ---

AT END OF DRILLING ---

AFTER DRILLING 26.00 ft

HOLE SIZE 4 inches

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