Addenda 1 - Geotechnical Report .pdf

COMMONWEALTH OF KENTUCKY

DEPARTMENT FOR FACILITIES AND SUPPORT SERVICES

DIVISION OF ENGINEERING AND CONTRACT ADMINISTRATION

INVITATION TO BID NO: RFB-228-23

FOR: New Indoor Firing Range Department Of Criminal Justice Training Richmond, Kentucky

DATE: March 27, 2023

RFB-785-2300000633

ADDENDUM NO. One (1)

BIDDER SHALL CONFORM TO THE FOLLOWING CHANGES AS SAME SHALL BECOME BINDING

UPON THE CONTRACT TO BE ISSUED IN RESPONSE TO THIS INVITATION TO BID.

Item 1: Addition of Geotechnical Report

Refer to addendum to be distributed by Lynn Imaging for all additions, deletions, and/or changes to specifications and/or drawings.

END OF ADDENDUM

Invitation to Bid No. RFB-228-23 For: New Indoor Firing Range Department Of Criminal Justice Training

Kyla Satterly, Statewide Procurement Analyst II Division of Engineering and Contract Administration

Final Report of Geotechnical Exploration

DOCJT Firing Range

Richmond, Kentucky

S&ME Project No. 22830277

PREPARED FOR:

EOP Architects

3225 Summit Square Place

Suite #200

Lexington, Kentucky 40509

PREPARED BY:

S&ME, Inc.

2020 Liberty Road, Suite 105

Lexington, Kentucky 40505

January 26, 2023

EOP Architects

3225 Summit Square Place

Suite #200

Lexington, Kentucky 40509

Attention: Mr. Andrew Moore, AIA, LEED AP BD+C

Reference: Report of Geotechnical Exploration

S&ME Project No. 22830277

Dear Mr. Moore:

S&ME, Inc. (S&ME) has completed our geotechnical exploration for the new DOCJT Firing Range facility near the

Eastern Kentucky University campus in Richmond, Kentucky. We performed our work in accordance with S&ME

Proposal 22830277 dated October 19, 2022. The purpose of this exploration was to obtain subsurface data at the site and provide geotechnical recommendations for design and construction of the new firing range facility.

This report explains our understanding of the project, documents our findings, and presents our conclusion and engineering recommendations.

Sincerely, S&ME, Inc.

Andrew M. Fiehler, P.E. Timothy S. Lawrence, PE

Senior Geotechnical Engineer Senior Geotechnical Engineer

Licensed Kentucky 23,977

Geotechnical Exploration

January 26, 2023 iii

Table of Contents

1.0 INTRODUCTION

2.0 PROJECT INFORMATION

3.0 SITE DESCRIPTION

4.0 REGIONAL GEOLOGY

5.0 EXPLORATION METHODS

5.1 Field Exploration

5.2 Laboratory Testing

6.0 SUBSURFACE CONDITIONS

7.0 CONCLUSIONS AND RECOMMENDATIONS

7.1 General Discussion

7.2 Site Preparation

7.3 Structural Fill Placement

7.4 Foundation Recommendations

7.5 Seismic Site Classification

7.6 Stem Wall/Loading Dock/Site Retaining Walls

7.7 Floor Slab Recommendations

7.8 Pavement Recommendations

8.0 FOLLOW-UP SERVICES

9.0 LIMITATIONS OF REPORT

Appendices Appendix I – Site Location Plan / Boring Location Plans

Appendix II – Boring Logs / Test Pit Logs

Appendix III – Laboratory Testing Results

January 26, 2023 1

1.0 INTRODUCTION

S&ME, Inc. (S&ME) has completed our geotechnical exploration for the new DOCJT Firing Range facility near the

Eastern Kentucky University campus in Richmond, Kentucky. We performed our work in accordance with S&ME

Proposal 22830277 dated October 19, 2022. The purpose of this exploration was to obtain subsurface data at the site and provide geotechnical recommendations for design and construction of the new firing range facility.

This report explains our understanding of the project, documents our findings, and presents our conclusions and engineering recommendations.

2.0 PROJECT INFORMATION

The project is under schematic planning by EOP Architects and Carman Site. The project will encompass approximately 45,000 square feet with a partial mezzanine with load bearing masonry walls and a partial steel frame. The firing range will have clear spans of 150 feet by 180 feet. A basement is not anticipated however site retaining walls are possible. The provided schematic of the project also shows a loading dock at the southwest corner of the building. Mr. Kubican noted that column loads of 350 kips and wall loads in excess of 8.5 kips per linear foot are anticipated.

The topographic mapping on the schematic plan indicates that there is approximately 10 to 12 feet of relief in the building area. Grading plans for the site are under development. Mr. John Carman with Carman Site anticipates a preliminary finished floor elevation of 990.5 feet though the grading plan has not yet been finalized and this FFE may be lowered to help balance the site grading.

3.0 SITE DESCRIPTION

The project site is located on the south side of the Eastern Kentucky University (EKU) campus at the Department of

Criminal Justice Training (DOCJT) facilities. The project site has been disturbed. A portion of the site has been used as a disposal area for debris and other excavation activities on campus. From our exploration, it also appears that soil was “borrowed” from the eastern portion of the building footprint and backfilled with waste materials from other project sites. The dumped materials consisted largely of a mixture of soil and rock fragments though we did observe concrete pieces, asphalt pieces, assorted pipe pieces, and limited amounts of trash such as benches, pipe pieces, and a fuel transfer tank. We also observed several areas of compostable materials (wood, leaves, etc.).

Provided topographic mapping of the site indicates about 10 to 12 feet of relief in the building footprint. Based on the current site elevations and an FFE of 990.5 feet, we anticipate about 3 to 5 feet of cut and up to 6 feet of fill within the building. A portion of the near surface materials in the cut area consist of existing fill materials.

January 26, 2023 2

4.0 REGIONAL GEOLOGY

A review of the United States Geologic Survey (USGS) geologic map of the Richmond South Quadrangle (1966) indicates that the project site is underlain by the Ashlock formation.

The Richmond South quadrangle divides the Ashlock Formation into Five members including the Upper Part consisting of the Reba and Terrill members and the Lower part with the Stingy Creek, Gilbert, and Tate members.

The differences in the members are based on the classifications of the individual geologists preparing the maps and the names they assigned to the different geologic horizons. The four members of the formation are similar and consist of limestone with calcareous shale with varying percentages and layer thicknesses of the constituents.

Rock cores from two of our borings (B-4 and B-8) were described as limestone with shale partings consistent with the Gilbert Member which is located in the lower part of the formation.

Karst Topography, Sinkholes and Depressions

The most common feature of Karst topography in Central Kentucky is a highly variable bedrock surface or closed depression at the ground surface. Since the site has been developed in the past (both cut and fill placement), surface features present prior to development have likely been covered or filled in. While there is some variability of the bedrock surface in our borings and soundings, we do not consider it to be erratic or suspect for development of Karst features such as sinkholes.

Karst regions typically lack a well-defined surface drainage system. Karst topography is defined as areas underlain by carbonate limestone, which is generally soluble in water. Rainfall infiltration penetrates the surface vegetation and moves through fractures in the limestone. As water penetrates the rock joints, solutioning of the bedrock occurs and cavities in the bedrock develop. As the cavity continues to grow, the cavity roof arch can no longer support the overburden load. The overlaying soil begins to sag and creates a dish-shaped area (closed depressions) on the surface. A sinkhole develops when the overburden collapses into the cavity. As the collapsed soils are washed into the cavity (also known as solution features), sinkhole throats begin to develop.

During our exploration we did not observe sinkholes on the property; however, previous site grading may have hidden such features. Our experience in the Richmond area is that soil filled, solution widened joints in the bedrock are the most common Karst feature encountered during construction. These features, commonly referred to as slots, are relatively isolated and can be readily remediated during construction if encountered. If such features are encountered, we should be contacted to further evaluate the site conditions and provide recommendations for remediation.

5.0 EXPLORATION METHODS

The procedures used by S&ME for field and laboratory sampling and testing are in general accordance with ASTM procedures and established engineering practice. Appendix II contains brief descriptions of the procedures used in this exploration.

January 26, 2023 3

5.1 Field Exploration

Our field exploration included a site reconnaissance by a geotechnical engineer, excavation of 9 test pits, and the performance of 10 soil test borings with standard penetration testing (SPT) and undisturbed sampling techniques, and 2 mechanical rock soundings (borings without sampling). Upon completion, the as-excavated/as-drilled locations were surveyed and are shown on the Boring Location Plan (Figures 2) in Appendix I.

Mr. Andrew Fiehler, P.E. and Mr. Deron Zierer, GIT of S&ME were on-site during the test pit excavation and drilling operations to observe pertinent site features and log the excavations and borings. The test pits were excavated with a John Deer 330 tracked excavator. The borings were drilled using a track-mounted Diedrich D-50 drill rig using 4-1/4 inch O.D. solid flight augers. Soil samples were obtained using a split-barrel sampler driven by an automatic hammer system in general accordance with ASTM D1586. We obtained relatively undisturbed (Shelby) tube samples of the soil using direct push methods. Rock coring was performed in two of the soil test borings. A bulk sample of auger cuttings was obtained from the anticipated cut area for laboratory testing. The stratification lines shown on the boring record represent the approximate boundaries between soil types. The transitions may be more gradual than shown. A general description of our field procedures, a test boring record legend and

Boring Logs are provided in Appendix II of this report.

5.2 Laboratory Testing

The recovered soil samples were placed in plastic storage bags and were visually classified by a geotechnical engineer according to the Unified Soil Classification System during the field operations. The recovered samples were returned to our laboratory where applicable soil tests were performed. S&ME conducted natural moisture content determinations, Atterberg limits testing, unconfined compressive strength tests, and standard Proctor testing on representative soil and rock core samples. The samples were selected by the geotechnical engineer to aid in determining certain engineering properties of the soil and bedrock pertinent to the proposed design and construction of the firing range.

The results of the laboratory testing completed to date are summarized in Appendix III.

6.0 SUBSURFACE CONDITIONS

As discussed, the project site has been manipulated multiple times in the past. From our exploration and discussions with the project team, the site has been used as a waste area for materials excavated elsewhere on the

EKU campus. It also appears that a portion of the building footprint was a borrow source for soil. These varying generations of excavation and dumping of materials have resulted in highly variable site subsurface conditions.

In general, the eastern half of the building area appears to have been used as a borrow source that was backfilled with a fill mixture of soil and limestone with varying amounts of debris. The image below outlines our estimation of the area where the natural soils were removed and backfilled. The depth of the undercut and backfill appears to be deeper to the east (up to 10 to 12 feet below finished grade) and shallower near the middle of the building

(approximately 2 to 4 feet).

The backfill soil is a mixture of low plasticity (lean) clay (CL) and high plasticity (fat) clay (CH) with rock pieces ranging from small gravel up to boulders/slabs up to 6 feet across and 1 foot thick. Boring B-8 encountered

January 26, 2023 4 refusal at a depth of 6.6 feet; however, coring of the refusal material indicated auger refusal was on a limestone boulder and that bedrock surface was actually at a depth of 16.8 feet. We expect that boring B-9 and Test Pit TP-7 also encountered “false refusal” on rock pieces rather than bedrock. We also observed assorted deleterious debris such as concrete fragments (sidewalk pieces, parking stops, etc.), asphalt pieces, and pipe (both metal and plastic) pieces.

Approximate limits of previous deep borrow area in pink

It appears that some of the original soils were removed from the central portion of the building area (borings B-3, B-4 and B-10); however, the bedrock elevation in the central portion of the building is closer to the planned finished grades.

The western third of the building (borings B-1 and B-2) also includes the miscellaneous fill; however, we observed residual soil beneath the fill.

January 26, 2023 5

Based on the exploration locations within the building footprint bedrock appears to range from about 3 feet to 12 feet beneath the planned finished floor elevation although may be deeper than 19 feet below the FFE.

Detailed Test Boring Logs and Test Pit Logs are included in Appendix II which include specific measurements from the individual soil test borings and test pit excavations.

7.0 CONCLUSIONS AND RECOMMENDATIONS

7.1 General Discussion

The following recommendations are based upon a revised FFE of 990.5 feet as provided by Mr. John Carman. We understand that the FFE may be revised to help balance site grading operations. Our conclusions and recommendations are based on the conceptual design information furnished to us, the data obtained from the geotechnical exploration, and our experience with similar projects and the site vicinity. They do not reflect variations in the subsurface conditions which may exist between our borings and in unexplored areas of the site.

If such variations become apparent during construction, it will be necessary for us to re-evaluate our conclusions and recommendations based upon on-site observation of the conditions.

Based on discussions with the design team, the firing range portion of the building will consist of bedrock supported drilled shaft foundations tied together with grade beams to support a structural floor slab while the office portion of the building will be constructed with shallow foundations over-excavated to bedrock with a slab on grade floor system. The following sections of the report are tailored to address this design approach.

We have identified the following key issues to the development of this site:

Existing Fill

Varying Bedrock Elevation

High Plasticity Fat Clay

7.1.1 Existing Fill

The site has been used as a dumping ground for many years. Each of our borings and test pits encountered existing fill to varying depths. The fill was a heterogenous mixture of soil and rock pieces with limited amounts of deleterious material. We observed numerous large boulders scattered across the site with some as large as 6 feet across and 18 inches thick.

In our opinion, the existing fill does not appear to have been placed in an engineered manner and presents a high level of risk if not remediated prior to construction of the new facility. The design teams decision to use bedrock supported foundations with a structurally supported floor slab in the firing range area should greatly reduce the risks associated with the existing fill. The existing fill will be removed from the office area and backfilled with engineered structural fill to support the slab on grade floor of this portion of the building.

January 26, 2023 6

7.1.2 Varying Bedrock Elevation

Based on the exploration locations, the bedrock elevation ranges from about 983 feet along the western edge of the building, to about 987 feet in the central portion to as low as 971 feet on the eastern side of the building.

Based on an FFE of 990.5 (and the associated typical shallow spread foundation bearing elevation of 988.5 feet) the soil depth beneath the foundations would be significantly variable which can lead to differential settlement.

To help control the potential for differential settlement of the structure, the foundations will be supported by bedrock. Bedrock supported foundations are expected to consist of two variations – either over-excavated spread footings backfilled with lean concrete to the foundation bearing elevation where bedrock is close to the bearing elevation or drilled shaft foundations where bedrock is deeper than over-excavation is practical or economical.

7.1.3 High Plasticity Soils

Laboratory testing indicates that high plasticity (fat) clay with a plasticity index of up to 47 percent is present at the site. Based on the existing site grades and the proposed FFE, we anticipate that import soils will be required to achieve the anticipated grades. Our experience in Kentucky is clay with a plasticity index of greater than 30 percent often exhibits volume changes with fluctuations in seasonal moisture content (i.e. shrink and swell). This shrink/swell can cause floor slabs, concrete pavements, and other lightly loaded elements to crack. Methods used to reduce the risk associated with shrink/swell of the fat clay are:

Maintain the moisture of the high plasticity clay within three (3) percent of the natural moisture content for residual clays and within three (3) percent of the optimum moisture for newly compacted fill during construction.

Place low plasticity material such as lean clay or crushed stone in the upper three (3) feet of the building pad sub-grade.

Chemically stabilize the top three (3) feet with lime or cement.

As an alternative, higher plasticity clay can be placed in deeper fills or used in non-structural areas such as lawns or detention ponds.

7.2 Site Preparation

Prior to beginning cut and fill operations, the vegetation, topsoil, tree stumps, and other debris should be removed from the proposed construction areas. We recommend that entire rootball from any trees be removed.

The resulting holes from rootballs should be backfilled with compacted structural fill.

The existing fill should not be re-used as structural fill beneath the slab on grade portion (office area) of the building. It can be re-used beneath the structurally supported floor slab portion (firing range) provided debris and rock fragments greater than 6-inches are culled. The existing fill can also be used in non-structural areas outside the building and pavement areas provided debris and rock fragments greater than 6-inches are culled and the material is stable under proofrolling operations.

It is important an S&ME representative observes site stripping to assess that adequate (but not excessive) material has been stripped. Previously unexplored or unknown conditions could become evident during these operations.

S&ME must judge whether the recommendations in this report should be modified in view of the conditions

January 26, 2023 7 encountered. Once the initial site stripping is complete, S&ME should be retained to visit the site and assess the exposed grade before fill is placed. Observed soft areas should be remediated at the S&ME engineer’s discretion before moving on to subsequent tasks.

Once the initial site stripping and removal of existing fill from the building pad has occurred, we recommend a proofroll of the at-grade areas and areas to receive structural fill. Proofrolling consists of observing a loaded dump truck or scraper traffic over the planned fill area. Areas observed to exhibit excessive rutting and/or deflection should be remediated at the engineer’s direction. Areas where planned construction bears at or near the existing site grades may require stabilizing prior to beginning construction. Either undercutting and backfilling with structural fill or aerating/drying and re-compaction of the soil will likely be required.

To control distress associated with swelling clay the upper 3 feet of the floor slab subgrade should have a

Plasticity Index (PI) of 30 percent or less. The upper horizon of soil across the site classified as Lean Clay with a PI of less than 30 percent. Where fat clay is present within 3 feet of the building pad subgrade elevation, we recommend undercutting and replacing with lean clay or other suitable fill materials as described in following sections. Fat clay can be used as structural fill in deeper fill areas within the building footprint and below the top one-foot of asphalt pavement subgrade. It can also be used within 1 foot of the subgrade elevation beneath sidewalks that lead to entrances where they are more than 20 feet from the building, in lawn areas, for detention pond embankments, or in outslopes of other embankments.

If soils with potentially high plasticity are observed during site grading, additional Atterberg Limits testing should be performed.

7.3 Structural Fill Placement

7.3.1 Soil Fill

Structural soil fill being placed under the building pad shall occur in relatively thin (6 to 8-inch) layers and be compacted to at least 98 the percent of the standard Proctor maximum dry density. The moisture content of the fill should be maintained within three (3) percent of the soil’s optimum moisture content even though compaction may be achieved at moisture contents outside the specified range.

Structural fill is defined as inorganic natural soil with a maximum particle size of 3 inches and maximum dry density of at least 100 pounds per cubic foot (pcf) when tested by the standard Proctor method (ASTM D698).

The top 3 feet of the building pad or other grade supported improvements sensitive to movement of the underlying fat clay should have a Plasticity Index (PI) of less than 30 percent. A bulk sample of Lean Clay from boring B-3 meets both the plasticity and density requirements as shown in Table 7-1.

Table 7-1 – Moisture Density Relationship Test Results

Sample Plasticity Index (PI) Maximum Dry

Density (pcf)

Optimum Moisture

Content (%)

B-3, 2-4 ft 22 100.4 22.1

January 26, 2023 8

It is imperative that, during construction, additional standard Proctor testing and Atterberg limits testing of fill soils should be performed by S&ME for compliance with the project specifications before they are used as fill material. If soils are imported to the site, we recommend that the soils be tested for conformance with the project specifications before being transported to the site. Laboratory conformance testing usually takes three to four business days to complete. Therefore, the Contractor should plan accordingly.

7.3.2 Monitoring of Fill Placement

In-place density testing of structural soil fill must be performed as a check that the previously recommended compaction criteria have been achieved. This allows our project engineer to monitor the quality of the fill construction and verify that his design criterion is being achieved in the field. Performance of slabs-on-grade and foundations will depend directly on the quality of the fill construction. We further recommend that these tests be performed on a full-time basis by S&ME. The testing frequency for density tests performed on a full-time basis can be determined by our personnel based on the area to be tested, the grading equipment used, and construction schedule. Tests should be performed at vertical intervals of 8-inches or less (i.e., each lift) as the fill is being placed.

We recommend that an engineering technician working under the direction of our project geotechnical engineer perform the density tests.

Monitoring of shot-rock and soil/rock mix must be done visually by an experienced geotechnician working under strict supervision by one of S&ME’s senior geotechnical engineers. Placement of these materials is a blend of art and science and the experience of the equipment operator and testing personnel are crucial to achieving the desired performance from the fill. Key indicators include material type, gradation, soil percentage and moisture content, equipment used to place the material, uniformity of compactive effort, reduction of voids between rock pieces, and how the fill material reacts under the equipment. The placement criteria will vary somewhat as the material varies. For example - as the soil content increases, the lift thickness should be decreased.

7.4 Foundation Recommendations

S&ME recommends the foundations for the new firing range bear on intact limestone bedrock. We recommend the use of an allowable bearing pressure to 30 ksf (kips per square foot) to size foundations bearing on intact bedrock. We expect a combination of spread footings and end bearing drilled shafts bearing on bedrock will be used. The following sections include more detailed recommendations for each of the anticipated foundation types.

Shallow footings may be built/cast directly on bedrock. Where the overburden becomes thicker, footings may be extended to bear on bedrock or the overburden may be removed and the area filled with lean concrete up to the design bearing level. Areas of obvious deep fill, such as the eastern side of the building, would be appropriate for drilled shafts. The current geotechnical exploration program is insufficient to delineate which foundation type is appropriate for each column or foundation location. Based on our experience, several factors would be considered as to the selection of constructing a shallow footing versus a drilled pier at a given location, including unit or overall costs, overburden depth, structural loading, the foundation contractor’s preferences, methods, approach, etc. We suggest the contractor be prepared to conduct a pre-construction exploration program to help refine the foundation design and construction issues as well as to help reduce the potential for change orders.

January 26, 2023 9

7.4.1 Spread Footing Design and Construction Considerations

Where bedrock is near the foundation bearing elevation, over-excavating through the soil and backfilling with lean concrete to re-establish the foundation bearing elevation is acceptable provided the bedrock surface has been observed before backfilling. We recommend a minimum 28-day compressive strength of 2,000 psi concrete be used for backfilling beneath foundations.

To evaluate the bedrock beneath the spread footings, we recommend that 2-inch diameter probe holes be drilled to assess the continuity of the underlying bedrock. We recommend at least one probe hole be drilled every 25 feet along continuous footings that can be safely entered by personnel. Additionally, at least one probe hole may be requested for each column footing. Two or more probe holes may be required, at the discretion of the engineer, when the footing sizes exceed 25 square feet. We recommend that the project budget contain a unit price contingency for additional probe hole drilling if additional probe holes are required based on encountered subsurface conditions.

The probe holes should be drilled to a depth of 5 feet into the bedrock-bearing material for each spread footing foundation. These probe holes are usually drilled with a pneumatic percussion drill. The engineering technician should check the probe hole using a hooked-end steel feeler rod to assess the bedrock continuity. If this check indicates a discontinuous or compressible seam in the bedrock, the foundation should be excavated deeper.

Additional probe holes may be required by the Geotechnical Engineer to check foundations supported on marginal material.

Since the foundations will bear on bedrock, the frost depth requirement will not apply. We recommend all foundations have a minimum footing width of 24 inches to allow for hand cleaning of footing subgrades disturbed by the excavation process and the placement of reinforcing steel. The reinforcing steel should be clean and dry prior to concrete placement.

7.4.2 Drilled Shaft Design and Construction Considerations

For drilled shafts we recommend a minimum rock socket of 12-inches into intact limestone bedrock. Additionally, a 25 percent increase in the allowable axial unit end bearing pressure may be used for short term (transient) load increases. At that magnitude of transient increase, deflections will be within the elastic response zone of the rock and will not result in permanent deflection. S&ME recommends that any increases in design values for short term loadings due to wind and seismic loads be in accordance with the Kentucky Building Code or other applicable

Code. For either axial or uplift side resistance in a rock socket, an allowable unit side resistance for the unweathered limestone of 125 psi can be used (assuming 4,000 psi concrete for the drilled shafts)

The following construction considerations are recommended for end bearing drilled shaft construction:

End Bearing

Clean the foundation bearing area so it is nearly level or suitably benched and is free of ponded water or loose material.

Provide a minimum drilled shaft diameter of 30 inches to reasonably enter the drilled shaft excavation for cleaning, bottom preparation, and inspection.

January 26, 2023 10

Make provisions for groundwater removal from the drilled shaft excavation after rainfall events.

Subsurface water often occurs along the soil/rock interface for several days after rain. If water is flowing into the drilled shaft at less than 20 gallons per minute, pumps may be used to maintain less than 2 inches of water in the drilled shaft during cleaning and inspection. After approval of the bearing surface, the pumps should be pulled and concreting commenced immediately. If more than 20 gallons per minute are flowing into the drilled shaft, the water level should be allowed to stabilize before attempting to place the concrete. For this condition, concrete placement should be accomplished using a tremie pipe or concrete pumping equipment.

Specify a concrete slump of 7 to 9 inches for the drilled shaft construction. This slump is recommended to fill irregularities along the sides and bottom of the drilled shaft, displace water as it is placed, and permit placement of the fluid concrete around the reinforcing cage.

Retain S&ME personnel to observe foundation excavations after the bottom of the hole is leveled, cleaned of any mud or extraneous material, and de-watered.

Install temporary (if no voids greater than 6 inches are encountered) or permanent (if voids greater than

6 inches are encountered) protective steel casing or Sonotube to prevent side wall collapse, prevent excessive mud and water intrusion, and to allow workers to clean and inspect the drilled shaft.

Where temporary casing is required, the protective steel casing may be extracted as the concrete is placed provided a sufficient head of concrete is maintained inside the steel casing to prevent soil or water intrusion into the newly placed concrete.

Direct the concrete placement into the drilled shaft through a centering chute or tremie to reduce side flow or segregation.

Side Resistance

For side resistance design, we will require cleaning of the socket "face" prior to concrete placement.

Cleaning will require hand cleaning or washing if a mud smear forms on the face of the rock. The geotechnical engineer should approve the rock socket surface prior to concrete placement.

Provide a minimum drilled shaft diameter of 30 inches to reasonably enter the drilled shaft excavation for cleaning, rock socket face preparation, and inspection.

Make provisions for groundwater removal from the drilled shaft excavation after rainfall events.

Subsurface water often occurs along the soil/rock interface for several days after rain. If water is flowing into the drilled shaft at less than 20 gallons per minute, pumps may be used to maintain less than 2 inches of water in the drilled shaft during cleaning and inspection. After approval of the bearing surface, the pumps should be pulled and concreting commenced immediately. If more than 20 gallons per minute are flowing into the drilled shaft, the water level should be allowed to stabilize before attempting to place the concrete. For this condition, concrete placement should be accomplished using a tremie pipe or concrete pumping equipment.

Specify a concrete slump of 7 to 9 inches for the drilled shaft construction. This slump is recommended to fill irregularities along the sides and bottom of the drilled shaft, displace water as it is placed, and permit placement of the fluid concrete around the reinforcing cage.

Retain S&ME personnel to observe foundation excavations after the bottom of the hole is leveled, cleaned of any mud or extraneous material, and de-watered.

Install temporary (if no voids greater than 6 inches are encountered) or permanent (if voids greater than

6 inches are encountered) protective steel casing or Sonotube to prevent side wall collapse, prevent excessive mud and water intrusion, and to allow workers to clean and inspect the drilled shaft.

January 26, 2023 11

Where temporary casing is required, the protective steel casing may be extracted as the concrete is placed provided a sufficient head of concrete is maintained inside the steel casing to prevent soil or water intrusion into the newly placed concrete.

Direct the concrete placement into the drilled shaft through a centering chute or tremie to reduce side flow or segregation.

7.4.3 Drilled Shaft Rock Excavations

Our experience indicates general drilled shaft construction and delineation of "rock" in the excavation is greatly facilitated if adequate drilling equipment is used. We recommend the use of a drill capable of producing at least

500,000 inch·pounds of torque and 35,000 pounds of downward force. Additionally, we recommend that rock be defined as material which cannot be penetrated by a heavy-duty earth auger with hardened teeth at a rate in excess of 3 inches per minute.

Note that the unconfined compressive strengths for the tested rock cores ranged from 10,000 psi to 12,672 psi which are moderately high for limestone in Central Kentucky. The drilled shaft contractor should review the attached laboratory results when bidding and preparing for the project.

7.4.4 Drilled Shaft Quality Control Requirements

We recommend that the drilled shaft construction be observed by an S&ME geotechnical engineer or an S&ME, ICC Certified Special Inspector experienced in drilled shaft construction. The observation should address the following items:

Top location within tolerances

Correct plan dimensions

Plumbness within tolerances

Materials excavated agree with borings

Statement of bottom cleanliness

Construction procedure

Drilled shafts with diameters of 30-inches or greater are large enough to allow a down-hole inspection of the bearing conditions. S&ME will assess the rock condition during construction using 2-inch diameter probe holes to evaluate the actual condition at each shaft location. We recommend drilling the probe holes at least 5-feet into the rock-bearing material for all drilled shafts. These probe holes are usually drilled with a pneumatic percussion drill by the Contractor. S&ME will check the probe hole using a hooked-end steel feeler rod to assess the rock continuity and to check for the presence of mud seams or voids. If this check indicates a discontinuity or void in the rock, our Engineer will compute the expected settlement for that shaft using elastic theory. If the calculated settlement exceeds the allowable, our Engineer will require that the drilled shaft be excavated deeper. Additional probe holes may be required by the S&ME Geotechnical Engineer to check foundations supported on marginal material.

7.5 Seismic Site Classification

The current seismic design procedures outlined in the NEHRP (National Earthquake Hazard Reduction Program) guidelines mandate structural design loads to be based on the seismic coefficients of the site. Based on the results

January 26, 2023 12 of our exploration and the geology of the area, we recommend a site seismic classification of “C” for this project site. This classification is further defined in the Kentucky Building Code.

7.6 Stem Wall/Loading Dock/Site Retaining Walls

A stem wall will be constructed at the loading dock area. The loading dock wall will also act as a retaining wall.

The stem wall will have to resist a lateral earth pressure from the backfill below the slab and will not be free to rotate and thus should be designed using the at-rest condition (Ko). Place a 2-foot zone of KYTC No. 57’s between the wall and inner side of the wall as backfill connected to a drain and outlet. The stone layer will help prevent the development of hydrostatic pressures and reduce the risk of settlement behind the loading dock wall where compaction equipment access is limited.

If the values presented below for No. 57 stone are used in design, a sufficient width of No. 57 must be placed behind the wall so that a Rankine failure surface would develop within the crushed stone backfill. The Rankine failure surface is defined by a 1H:1V slope projected from the base of the wall foundation to the proposed finished grade. In areas where the face of the limestone falls within the Rankine failure surface, the lateral earth pressure coefficients will be conservative. The following table presents the lateral earth pressure coefficients for the loading dock wall.

Where the floor slab loads or pavement will apply pressure to the wall, the wall design should also factor in the lateral load imparted by the traffic loads. This is often modeled as a traffic surcharge line load of 250 psf.

Table 7-2 – Lateral Earth Pressure Parameters

Backfill Material Φ’ Unit Weight Active (Ka) At-Rest (Ko) Passive (Kp)

KYTC No. 57 Stone 40° 105 pcf 0.22 0.36 4.6

Lean or Fat Clay (CL / CH) 24° 120 pcf 0.42 0.59 2.3

7.7 Floor Slab Recommendations

The planned building will have a FFE of 990.5 feet. Based on the observed surface elevations and planned site development, the office area floor slab will be supported by newly placed and compacted fill. The firing range area floor slab will be constructed to be supported by the foundation system. We recommend the upper three feet of the building pad subgrade, especially beneath slab on grade floors, consist of low plasticity fill with a plasticity index (PI) of less than 30 percent, Dense Graded Aggregate (DGA), or quarry screenings.

We recommend that control joints be placed in the slab around columns and along footing supported walls to reduce cracking due to minor differential settlements. We recommend that ACI guidelines for floor slab construction be followed for design and placement of concrete floor slabs.

Between completion of grading and slab construction, floor slab subgrades are often disturbed by weather, footing and utility line installation, and other construction activities. For this reason, the subgrade should be evaluated by an S&ME engineer immediately prior to constructing the slab.

January 26, 2023 13

Floor slabs should be structurally independent of any building footings or walls to reduce the possibility of floor slab cracking caused by differential movements between the slab and foundation. Where floor slabs are tied to perimeter walls or turn-down slabs to meet structural or other construction objectives, our experience indicates that any differential movement between the walls and slabs will likely be observed in adjacent slab expansion joints or floor slab cracks that occur beyond the length of the structural dowels. The structural engineer should account for this potential differential settlement through use of sufficient control joints, appropriate reinforcing or other means.

7.8 Pavement Recommendations

In order for the pavement to perform satisfactorily, the subgrade soils must have sufficient strength and be stable enough to avoid deterioration from construction traffic and support the paving equipment. In addition, the completed pavement section must resist freeze/thaw cycles and wheel loads from traffic. Generally, construction traffic loading is more severe than the traffic after construction.

Minimizing infiltration of water into the subgrade and rapid removal of subsurface water are essential for the successful long-term performance of the pavement. Both the subgrade and the pavement surface should have a minimum slope of one-quarter inch per foot to promote surface drainage. Edges of the pavement should provide a means of water outlet by extending the aggregate base course through to side ditches. Side ditches should be at least 2 feet below the pavement surface.

Where pavements such as loading dock driveways, driveways into bay doors, or sidewalks abut the building, we recommend that the upper 2 feet of subgrade extending at least 10 feet from the building consist of stiff or better residual soil or controlled structural fill. If existing fill is present in this zone, we recommend undercutting and replacing with structural soil fill or compacted crushed limestone.

The pavement materials should conform and be placed and compacted in accordance with the applicable sections of the Kentucky Transportation Cabinet (KTC) Standard Specifications for Road and Bridge Construction, latest edition. We used the American Association of State Highway and Transportation Officials (AASHTO) Guide for

Design of Pavement Structures (1993) as a basis for our flexible pavement thickness analysis.

The following parking lot pavement design recommendations are based on the assumptions of a 20-year service life, a CBR value of 3 percent, 10,000 ESAL’s for light duty pavement (light duty parking lot) and 50,000 ESAL’s for heavy duty pavement (drive lanes and drop off lanes). If actual or anticipated traffic volumes exceed the estimated

ESAL value used for this design, S&ME must re-evaluate the pavement thickness recommendations. The total pavement thickness requirement is obtained from the AASHTO nomograph in terms of a structural number (SN), a weighted sum of the pavement layer thicknesses accounting for their structural and drainage properties.

S&ME recommends that the pavement section (base stone and asphalt) be placed after the majority of the new building construction has been completed. S&ME recommends that both binder and surface mix asphalt be placed sequentially before traffic is allowed on the new pavement. S&ME recommends that the light duty pavement section be used for automobile parking only.

The following pavement thickness design recommendations will likely NOT provide a sufficient pavement for haul roads or construction traffic. Expect that at least isolated repairs will be required to roadways

January 26, 2023 14 following major phases of construction. If construction sequencing requires that new pavement areas be constructed prior to substantial completion of the building, do not allow construction traffic on the finished pavement. Designating dedicated construction routes can help limit the areas requiring repairs to those areas.

S&ME recommends the following flexible asphalt pavement sections for this project:

Table 7-3 – Flexible Pavement Bearing on Soil

Material Light Duty Heavy Duty KY Transportation

Cabinet Specification

Asphalt Surface Course 1-½ Inches 1-½ Inches Section 400

Asphalt Binder Course 3 Inches 5 Inches Section 400

Crushed Stone Base 5 Inches 6 Inches Section 303

Our pavement recommendations are based on the assumption that S&ME is retained to monitor the installation of the asphalt and base, check the installed thickness of the aggregate materials, and perform in-place density tests. Asphalt placement should be monitored full-time to observe placement and compaction procedures.

Asphalt samples should be collected periodically and tested for asphalt cement content, aggregate gradation, and density.

Impervious Concrete Pavement – Preliminary development plans show concrete paving for the truck delivery areas and the delivery vehicle loading areas. We recommend that in areas where heavy, concentrated loads (i.e., dumpster area, entrances, loading docks, etc.) are expected, a rigid (concrete) pavement section be used. For dumpster areas, we recommend that rigid pavement be extended beyond the dumpster pad for the entire length of the garbage truck loading area. The pavement subgrade should be stabilized in accordance with the recommendations for the asphalt paved areas, and the related recommendations in this report. We recommend that the concrete pavement be supported by at least a 6-inch layer of compacted DGA. The DGA should be compacted to a minimum of 95 percent of the standard Proctor maximum dry density. We recommend a minimum concrete section of 6 inches for this site. The concrete should be air-entrained and have a 28-day compressive strength of 4,500 psi. Joint spacing should be at a maximum spacing of 15 feet each way.

8.0 FOLLOW-UP SERVICES

Our services should not end with the submission of this geotechnical report. S&ME should be kept involved throughout the design and construction process to maintain continuity and to assess whether our recommendations are properly interpreted and implemented. To achieve this, we should be retained to review project plans and specifications with the designers to see that our recommendations are fully incorporated. We also should be retained to observe and test the site preparation, foundation excavation, and building construction.

If we are not allowed the opportunity to continue our involvement on this project, we cannot be held responsible for the recommendations in this report.

Our familiarity with the site and with the foundation recommendations will make us a valuable part of your construction quality assurance team. In addition, a qualified engineering technician should observe and test all

January 26, 2023 15 structural concrete and steel. Only experienced, qualified persons trained in geotechnical engineering and familiar with foundation construction should be allowed to evaluate and test foundation excavations. Normally, full-time observations and testing of the site work and foundation installation is appropriate.

9.0 LIMITATIONS OF REPORT

This report has been prepared in accordance with generally accepted geotechnical engineering practice for specific application to this project. The conclusions and recommendations contained in this report are based upon applicable standards of our practice in this geographic area at the time this report was prepared. No other representation or warranty either express or implied, is made.

We relied on project information given to us to develop our conclusions and recommendations. If project information described in this report is not accurate, or if it changes during project development, we should be notified of the changes so that we can modify our recommendations based on this additional information if necessary.

Our conclusions and recommendations are based on limited data from a field exploration program. Subsurface conditions can vary widely between explored areas. Some variations may not become evident until construction. If conditions are encountered which appear different than those described in our report, we should be notified. This report should not be construed to represent subsurface conditions for the entire site.

Unless specifically noted otherwise, our field exploration program did not include an assessment of regulatory compliance, environmental conditions or pollutants or presence of any biological materials (mold, fungi, bacteria).

If there is a concern about these items, other studies should be performed. S&ME can provide a proposal and perform these services if requested.

S&ME should be retained to review the final plans and specifications to confirm that earthwork, foundation, and other recommendations are properly interpreted and implemented. The recommendations in this report are contingent on S&ME’s review of final plans and specifications followed by our observation and monitoring of earthwork and foundation construction activities.

For more information on the use and limitations of this report, please read the Geoprofessional Business

Association (GBA) document that follows this page.

Geotechnical-Engineering Report

Geotechnical Services Are Performed for Specific Purposes, Persons, and Projects Geotechnical engineers structure their services to meet the specific needs of their clients. A geotechnical-engineering study conducted for a civil engineer may not fulfill the needs of a constructor — a construction contractor — or even another civil engineer. Because each geotechnical- engineering study is unique, each geotechnical-engineering report is unique, prepared solely for the client. No one except you should rely on this geotechnical-engineering report without first conferring with the geotechnical engineer who prepared it. And no one

— not even you — should apply this report for any purpose or project except the one originally contemplated.

Read the Full Report Serious problems have occurred because those relying on a geotechnical-engineering report did not read it all. Do not rely on an executive summary. Do not read selected elements only.

Geotechnical Engineers Base Each Report on a Unique Set of Project-Specific Factors Geotechnical engineers consider many unique, project-specific factors when establishing the scope of a study. Typical factors include: the client’s goals, objectives, and risk-management preferences; the general nature of the structure involved, its size, and configuration; the location of the structure on the site; and other planned or existing site improvements, such as access roads, parking lots, and underground utilities. Unless the geotechnical engineer who conducted the study specifically indicates otherwise, do not rely on a geotechnical-engineering report that was:

• not prepared for you;

• not prepared for your project;

• not prepared for the specific site explored; or

• completed before important project changes were made.

Typical changes that can erode the reliability of an existing geotechnical-engineering report include those that affect:

• the function of the proposed…