Report Information
Status: Completed
Uploaded: Jan 03, 2026 16:28
Uploaded by: Anonymous
PDF File
Summary
The geotechnical exploration for the proposed Medical Center located at the northwest corner of Highway 32 and Davis Drive in Bolivar, Missouri, involved eight borings (B-1 through B-8) drilled to depths ranging from approximately 10 to 31 feet below the existing ground surface. The subsurface profile revealed the presence of undocumented fill materials extending to depths of 2 to 4.5 feet, underlain by medium stiff to very stiff fat clays, and limestone bedrock with voids noted at depths of 18 to 19.5 feet. Groundwater was not encountered in most borings, but fluctuations may occur due to seasonal variations. The site is characterized by high plasticity clays that are prone to volume changes, and the potential for sinkhole development exists due to the karst geology of the area, which may pose risks for structures supported on shallow foundations.
For the foundation design, it is recommended to utilize a drilled pier foundation system that extends below any identified voids in the bedrock, with a structural slab to mitigate potential settlement issues. The net allowable bearing pressure for shallow foundations is estimated at 2,000 psf, with a minimum embedment depth of 3 feet. A 24-inch thick Low Volume Change (LVC) zone should be constructed beneath grade-supported floor slabs to reduce the risk of volume change. Construction considerations include the removal of undocumented fill and the potential need for subgrade stabilization due to the presence of soft or unstable soils. Overall, the site is deemed suitable for the proposed construction, provided that the outlined recommendations are followed to address the identified geotechnical challenges.
Document Sections
| Section Type | Start Page | End Page | Description |
|---|---|---|---|
| Site Description | 1 | 2 | Introduction to the project, including location and client information. |
| Executive Summary | 5 | 6 | Summary of geotechnical exploration findings and recommendations. |
| Introduction | 7 | 7 | Overview of the geotechnical exploration purpose and methods. |
| Project Information | 7 | 9 | Details about the project description and site location. |
| Subsurface Conditions | 9 | 11 | Description of subsurface soil conditions, including typical profiles and geology. |
| Groundwater Conditions | 11 | 11 | Summary of groundwater observations during drilling. |
| Recommendations for Design and Construction | 12 | 23 | Detailed geotechnical recommendations for foundations, earthwork, and construction. |
| General Comments | 23 | 23 | Additional comments and considerations for the project. |
| Appendices | 4 | 4 | Includes field exploration details, laboratory testing, and supporting documents. |
Boring Log Pages: 38, 39, 40, 42, 43, 44
Key Fields
Fill Depth Range
Range: 2.0 - 4.5 feet
Reference: Found in the Executive Summary: existing undocumented fill encountered to depths of approximately 2 to 4½ feet.
Bearing Stratum
Description: Medium stiff to very stiff fat clays (CL)
Depth Range: 4.5 - 31.0 feet
Reference: Identified in the Typical Profile section, where fat clays were noted from 4.5 feet to undetermined depths.
Groundwater Depth
Depth: 27.0 feet
Note: Encountered during drilling in boring B-4.
Reference: Found in the Groundwater section, where B-4 showed groundwater at 27 feet after drilling.
Recommended Bearing Capacity
Value: 2000 psf
Foundation Type: shallow
Reference: Stated in the Foundation Recommendations section for shallow foundations.
Settlement Limits
Total Settlement: 1.0 inches
Reference: Estimated total settlement from foundation loads is up to 1 inch.
Differential Settlement: 0.75 inches
Reference: Estimated differential settlement from foundation loads is less than ¾ inch.
Pile Load Capacity
Pile Type: Drilled Pier
Compression Capacity: 1600 psf
Reference: Allowable end bearing pressure for drilled piers in limestone.
Tension Capacity: None
Reference: No tension capacity specified in the report.
Notes: Minimum pier length of 4 diameters required.
Foundations Information
Foundations Summary
The geotechnical report for the proposed Medical Center in Bolivar, Missouri, outlines recommendations for both shallow and deep foundation systems due to the presence of karst conditions and undocumented fill. Shallow foundations are recommended to bear on suitable native soils or engineered fill, while deep foundations, specifically drilled piers, are suggested to mitigate risks associated with voids in the bedrock. The report emphasizes the importance of site preparation and the need for careful evaluation of subsurface conditions during construction.
General Foundation Recommendations (Shallow Foundations)
Foundation Type: Shallow Foundation
Allowable Bearing Capacity: 1.2 ksf
Reasoning: The net allowable bearing pressure is based on suitable native medium stiff to stiff fat clays or new engineered fill.
Depth Requirement: 3.0 feet
Reasoning: Minimum embedment below finished grade is required for frost protection.
Settlement Criteria: up to 1 inch total, < ¾ inch differential
Special Foundation Recommendations (Deep Foundations)
Drilled Pier
Compression Capacity: 1600 psf
Reasoning: Allowable end bearing pressure for limestone below 18 feet.
Tension Capacity: None
Reasoning: Tension load capacity not specified.
Depth Requirement: 4.0 feet
Reasoning: Minimum pier length of 4 diameters required.
Installation Requirements: Pier drilling may require temporary casing due to groundwater and voids in bedrock.
Additional Recommendations
It is recommended that the geotechnical engineer be retained during construction to observe earthwork and foundation construction phases.
Boring Logs (6 found)
B-2 Terminated at 18.0 ft
Groundwater Level: No free water observed
| # | Depth (ft) | USCS | Description | SPT N | Sampler | Notes |
|---|---|---|---|---|---|---|
| 1 | 0 - 0.7 | - | TOPSOIL | - | - | - |
| 2 | 0.7 - 4.5 | CL-ML | FILL - SILTY CLAY (CL-ML), with gravel and organics, dark brown | 16 @ 2.5' | - | - |
| 3 | 4.5 - 18.0 | CH | FAT CLAY (CH), with gravel, red and light gray, stiff | 13 @ 6.7' | - | - |
Termination: Auger refusal on apparent bedrock or boulder. Auger Refusal at 18 Feet
B-3 Terminated at 16.6 ft
| # | Depth (ft) | USCS | Description | SPT N | Sampler | Notes |
|---|---|---|---|---|---|---|
| 1 | 0 - 0.7 | - | TOPSOIL | - | - | - |
| 2 | 0.7 - 3.5 | CL-ML | FILL - SILTY CLAY (CL-ML), with sand and organics, dark brown | 9 @ 2.0' | - | - |
| 3 | 3.5 - 9.5 | CH | FAT CLAY (CH), with gravel, trace hair roots, brown and red, stiff no roots noted below 5 feet possible sandstone seam at 9 1/2 feet | 13 @ 7.0' | - | - |
| 4 | 9.5 - 14.0 | CH | FAT CLAY (CH), with chert seams, light gray with red, stiff, Residual soil | 11 @ 12.0' | - | - |
| 5 | 14.0 - 16.6 | - | Auger refusal on apparent bedrock or boulder. | 15 @ 15.0' | - | - |
Termination: Auger refusal on apparent bedrock or boulder. Auger Refusal at 16.6 Feet
B-4 Terminated at 28.9 ft
| # | Depth (ft) | USCS | Description | SPT N | Sampler | Notes |
|---|---|---|---|---|---|---|
| 1 | 0 - 0.7 | - | TOPSOIL | - | - | - |
| 2 | 0.7 - 3.0 | CL-ML | FILL - SANDY SILTY CLAY (CL-ML), with organics, brown | 18 @ 3.0' | - | - |
| 3 | 3.0 - 5.5 | CL | SANDY LEAN CLAY (CL), brown, stiff, possible fill | 18 @ 5.0' | - | - |
| 4 | 5.5 - 13.0 | CH | FAT CLAY (CH), trace gravel, reddish brown, stiff | 8 @ 8.0' | - | - |
| 5 | 13.0 - 17.0 | CH | FAT CLAY (CH), with sand, trace gravel, red, stiff | 16 @ 15.0' | - | - |
| 6 | 17.0 - 23.0 | CH | FAT CLAY (CH), trace sand and gravel, red, medium stiff | 7 @ 20.0' | - | - |
| 7 | 23.0 - 28.0 | CH | FAT CLAY (CH), trace gravel, yellowish brown and reddish brown, stiff, residual soil | 10 @ 25.0' | - | - |
| 8 | 28.0 - 28.9 | - | SHALE, gray, completely weathered | 50 @ 28.0' | - | - |
Termination: Boring Terminated at 28.9 Feet
B-6 Terminated at 10.0 ft
| # | Depth (ft) | USCS | Description | SPT N | Sampler | Notes |
|---|---|---|---|---|---|---|
| 1 | 0 - 0.9 | - | TOPSOIL | - | - | - |
| 2 | 0.9 - 2.0 | CL-ML | FILL - GRAVELLY SILTY CLAY (CL-ML), with sand, dark brown | 12 @ 1.5' | - | - |
| 3 | 2.0 - 5.5 | CH | GRAVELLY FAT CLAY (CH), trace sand, red, very stiff | 22 @ 3.5' | - | - |
| 4 | 5.5 - 10.0 | CH | FAT CLAY (CH), with gravel, yellowish red, medium stiff to stiff | 7 @ 8.0' | - | - |
Termination: Boring Terminated at 10 Feet
B-7 Terminated at 10.0 ft
Groundwater Level: No free water observed
| # | Depth (ft) | USCS | Description | SPT N | Sampler | Notes |
|---|---|---|---|---|---|---|
| 1 | 0 - 0.7 | - | TOPSOIL | - | - | - |
| 2 | 0.7 - 4.0 | CL-ML | FILL - GRAVELLY SILTY CLAY (CL-ML), trace organics, dark brown | 14 @ 4.0' | - | - |
| 3 | 4.0 - 7.0 | CH | GRAVELLY FAT CLAY (CH), with sand, red, stiff | 20 @ 7.0' | - | - |
| 4 | 7.0 - 10.0 | CH | FAT CLAY (CH), with gravel, red and yellowish brown, medium stiff | 7 @ 10.0' | - | - |
Termination: Boring Terminated at 10 Feet
B-8 Terminated at 10.0 ft
Groundwater Level: No free water observed
| # | Depth (ft) | USCS | Description | SPT N | Sampler | Notes |
|---|---|---|---|---|---|---|
| 1 | 0 - 0.7 | - | TOPSOIL | - | - | - |
| 2 | 0.7 - 3.0 | CL-ML | FILL - SILTY CLAY (CL-ML), with gravel, sand, and organics, dark brown | 12 @ 3.0' | - | - |
| 3 | 3.0 - 5.5 | CH | FAT CLAY (CH), trace sand and gravel, red with brown and gray, stiff | 8 @ 5.5' | - | - |
| 4 | 5.5 - 7.0 | CH | FAT CLAY (CH), red and light gray, stiff | 10 @ 7.0' | - | - |
| 5 | 7.0 - 10.0 | CH | SANDY FAT CLAY (CH), reddish brown, stiff, Residual soil | 16 @ 10.0' | - | - |
Termination: Boring Terminated at 10 Feet