ATTACHMENT 4 - GEOTECHNICAL ENGINEERING REPORT.pdf

GEOTECHNICAL ENGINEERING REPORT

Air National Guard

Munitions Maintenance & Inspection Facility

XGFG182017

Truax Field

Madison, Wisconsin

GESTRA Project No.: M20068-10

November 30, 2020

Prepared For:

Hanson Professional Services, Inc.

13801 Riverport Drive, Suite 100

Maryland Heights, MO 63043

Geotechnical Engineering Report

Air National Guard

Munitions Maintenance & Inspection Facility

XGFG182017

GESTRA Project No. M20068-10

November 30, 2020

Prepared For:

Hanson Professional Services, Inc.

277 W. Nationwide Blvd.

Columbus, OH 43215

Prepared By:

GESTRA Engineering, Inc.

2223 Industrial Drive

Monona, WI 53713

(608) 222-9406

Table of Contents

1.0 INTRODUCTION

1.1 PROJECT INFORMATION

2.0 SCOPE OF WORK

3.0 EXPLORATION RESULTS

3.1 SITE CONDITIONS

3.2 PEDOLOGICAL INFORMATION

3.3 SUBSURFACE SOIL PROFILE

3.4 GROUNDWATER OBSERVATIONS

3.5 LABORATORY TEST SUMMARY

4.0 ANALYSIS AND RECOMMENDATIONS

4.1 SITE PREPARATION

4.2 FOUNDATION RECOMMENDATIONS

4.2.1 SHALLOW FOUNDATIONS

4.2.2 AGGREGATE PIERS

4.2.3 HELICAL PIERS

4.3 FLOOR SLAB RECOMMENDATIONS

4.4 SEISMIC SITE CLASSIFICATION

4.5 PAVEMENT DESIGN

4.6 SOIL CORROSIVITY

4.7 CONSTRUCTION CONSIDERATIONS

5.0 EXPLORATION AND TESTING PROCEDURES

5.1 LAYOUT AND ELEVATION PROCEDURES

5.2 FIELD TESTING PROCEDURES

5.3 LABORATORY TESTING PROCEDURES

STANDARD OF CARE

APPENDIX I SITE LOCATION MAP, BOREHOLE LOCATION MAP, TEST BORING LOGS,

GENERAL NOTES AND SOILS CLASSIFICATION

APPENDIX II LABORATORY TEST RESULTS

APPENDIX III WEB SOIL SURVEY

© GESTRA Engineering, Inc. 2020

Page 1 M20068-10

Geotechnical Engineering Report

Air National Guard

Munitions Maintenance & Inspection Facility

XGFG182017

1.0 INTRODUCTION

GESTRA Engineering, Inc. (GESTRA) was authorized by Hanson Professional Services, Inc.

(Hanson) to complete a subsurface exploration and geotechnical engineering report for the Air

National Guard (ANG) Munitions Maintenance & Inspection Facility project located at Truax

Field in Madison, Wisconsin. This report presents the results from the subsurface soil exploration and describes the field exploration, laboratory test results, and provides recommendations pertaining to the design and construction of the proposed building and pavement.

The engineering recommendations and analysis contained within this report are based on the following project information which is a projection of GESTRA’s understanding of the project. If for any reason the actual project information differs from what is reported below, GESTRA should be contacted so that we can review our recommendations in light of any new information.

1.1 PROJECT INFORMATION

The project area is located on the northern end of the ANG Truax Field. The project will consist of constructing a single bay Munitions Maintenance and Inspection building within the fenced in area just east of the taxiways.

The building is planned to be approximately 2,500 square feet in size. The exterior walls for the building will consist of two cast-in-place concrete walls, with earth fill placed between the walls.

The walls are planned to be supported on shallow foundations. At this time, the wall loads for the building are unknown, but it is assumed that the loads will be less than 7 kips per linear foot. The design floor elevation is not established at this time, but we assume it will be around elevation 856 feet.

An asphalt drive will be constructed on the southeast side of the building. The pavement section for the drive is planned as 4 inches of asphalt over 12 inches of aggregate base course.

2.0 SCOPE OF WORK

GESTRA has performed the following services for the project:

Contacted Diggers Hotline to locate public utilities at the site.

Staked borehole locations in the field using tape and stake methods. Elevation and coordinates of boring locations were determined by using a Geomax Zenith 35 GNSS-INS receiver and referenced to Wisconsin Carrier Registration System (WisCRS) Dane County

(NAVD88).

Completed a total of two (2) standard penetration test (SPT) soil borings, 1 to a depth of

11 feet and 1 to a depth of 26 feet. At the completion of drilling, the spoils produced from

Munitions Maintenance & Inspection Facility November 30, 2020

Page 2 M20068-10 boring B-7 were containerized in 55-gallon drums and the boreholes were abandoned per

WDNR requirements.

Performed laboratory soil testing to assign classification and engineering properties to the soils encountered. Laboratory testing included hand penetrometer, moisture and organic content, Atterberg limits, percent passing the number 200 sieve, modified Proctor, California Bearing Ratio (CBR) test, pH and Miller Box resistivity. GESTRA also subcontracted Testing Engineers International, Inc. to perform laboratory sulfate and pH testing.

Prepared this geotechnical engineering report presenting the results of the field and laboratory testing as well as providing the following recommendations:

a. Building: recommendations for shallow foundations, allowable soil bearing capacity, estimates of settlement, recommendations for helical piers and aggregate piers, floor slab recommendations, seismic site classification, site preparation/ soil correction and construction considerations.

b. Pavement: soil parameters for the pavement design consisting of an estimated CBR value for design of asphalt pavement, and subgrade modulus of soil reaction value for design of rigid pavement.

3.0 EXPLORATION RESULTS

3.1 SITE CONDITIONS

The existing site is currently a grass landscaped area with an underground Munitions Maintenance and Inspection building located northwest of the project site. Historical aerial photos indicate that the site and surrounding area was undeveloped in 1937. By 1955, a runway/ taxiway was constructed north of the site and an open at grade parking lot for aircrafts was constructed south of the site. By 2000, the runway/ taxiway was realigned to run in a more north to south direction.

By 2010, the existing Munitions Maintenance & Inspection facility, surrounding buildings and drive areas were constructed.

3.2 PEDOLOGICAL INFORMATION

The USDA NRCS Web Soil Survey was used to research the pedologic mapping within the project limits. We have included the Web Soil Survey map in Appendix III of this report for your reference. Wacousta Silty Clay Loam was mapped within the project limits.

Wacousta series consists of very deep, very poorly drained soils formed in silty lacustrine sediments. These soils are in broad depressions and swales on till plains, moraines, and stream terraces. These soil types are considered common subgrade material, and have generally fair to poor strength characteristics.

3.3 SUBSURFACE SOIL PROFILE

The borings for the Munitions Maintenance and Inspection building were completed in conjunction with other borings for multiple different projects at Truax Field. Borings B-6 and B-

7 were performed for our analysis for the new Munitions Maintenance & Inspection building. Both of the borings were performed in the grass landscaped area southeast of the existing Munitions

Maintenance & Inspection buildings. Boring B-7 was performed on a topsoil pile, approximately

Page 3 M20068-10

4 feet higher than boring B-6. The topsoil at the boring locations was observed to extend to a depth of 2 feet in boring B-6 and 5.2 feet in boring B-7.

Below the topsoil, fill was only encountered in boring B-7. The fill material consisted primarily of sand with clay seams and was observed to extend to a depth of 11.5 feet. The native soils typically consisted of loose to medium dense sand. In boring B-6, a 1.7-foot thick layer of clay was encountered directly below the topsoil. The native sand soil was observed to have N-values between 8 and 18 blows per foot (bpf).

Results of the field and laboratory tests and observations are depicted on the individual boring logs included in Appendix I. Soils were grouped together based on similar observed properties. The stratification lines were estimated by the reviewing engineer based on available data and experience. The actual in-situ changes between layers may differ slightly and may be more gradual than depicted on the boring logs. Subsurface and groundwater conditions can vary between borehole locations and in areas not explored.

It is important to note that the soil observations, fill depths and topsoil thickness estimates were made in small diameter boreholes. Therefore, it should be understood that thicker or thinner deposits of the individual strata are likely to be encountered within other portions of the project.

Furthermore, the estimation of a strata thickness at a particular location can differ from person to person due to a sometimes indistinct transition between the soils encountered. Additionally, it must be recognized that in the absence of foreign substances and/or debris within the soil samples obtained, it is sometimes difficult to distinguish between natural soils and clean soil fill.

3.4 GROUNDWATER OBSERVATIONS

Groundwater observations were made during drilling operations. Groundwater was observed at a depth of 4.5 feet (elevation 851.7 feet) in boring B-6 and 9.5 feet (elevation 580.8 feet) in boring

B-7. Accurate water level readings could not be made at the completion of drilling due to collapsing soils.

Groundwater level fluctuations may occur with time and seasonal changes due to variations in precipitation, evaporation, surface water runoff and local dewatering. Perched water pockets and a higher water table may also be encountered during wet weather periods, particularly in more permeable silt and sand seams or granular fill material overlying less permeable clays. Installation and monitoring of an observation well would be required to assess true groundwater elevation.

3.5 LABORATORY TEST SUMMARY

GESTRA collected bulk samples from the auger cuttings from borings B-6 and B-7. The bulk samples were combined to create a composite sample to represent the generalized soil profile of the upper subgrade soils. Based on design pavement loads, CBR tests were performed using a modified Proctor density (ASTM D1557). The details of laboratory results for the modified Proctor and CBR tests are provided in Appendix II. Following Table 3-1 summarizes the modified Proctor and CBR test results. It should be noted that the sample tested was collected from auger cuttings and was likely a mix of the material in our borings and actual soil types in situ may vary from our sample collected.

Page 4 M20068-10

Table 3-1: Summarized Modified Proctor and CBR Test Results of Subgrade Materials

Sample

Designation Sample Location

Modified Proctor (ASTM D1557) % CBR at 0.1 in penetration, 95% compaction

Max. Dry

Density

(pcf)

% Optimum

Moisture

Content

CBR-1 B-6 and B-7 127.3 9.0 10.5

Select samples of the subgrade soils were submitted for laboratory gradation testing. Table 3-2 provides a summary of the tests performed and associated USCS soil classification.

Table 3-2: Subgrade Soil Tests

Soil

Sample Sample Location

Grain Size Results

(% passing)

Atterberg Limit

Results (%) Soil Type

P4 P200 LL PI

CBR-1 B-6 and B-7 100 51.9 26 12

SANDY LEAN

CLAY, gray

P4= Percent passing sieve #4; P200= Percent passing sieve #200

4.0 ANALYSIS AND RECOMMENDATIONS

4.1 SITE PREPARATION

Site preparation should start with removal of surficial topsoil, vegetation, and debris or other deleterious material, if encountered. In addition, all unused utilities should be properly rerouted, removed or abandoned. Material removed from the project site should be disposed in accordance with all applicable federal, state, and local regulations. Soil should not be stockpiled near or adjacent to the excavations. Based on the borings performed, the topsoil depth ranged from 2 to

5.2 feet indicating significant topsoil removal may be necessary.

In the building slab on grade and pavement areas, after the initial site preparation described above, we recommend compacting the exposed material. Any areas of significant deflection during compaction may be disked, dried, and re-compacted if weather permits, or removed and replaced with engineered fill. After compaction is completed, we recommend the subgrade area should be proof rolled with a minimum 20-ton tandem axle duel wheel dump truck. A geotechnical engineer or their designated representative should be present during the proof roll in order to identify soft or unstable areas, if any, and subsequently recommend remediation procedures.

Soft areas of subgrade that deflect more than 1-inch or show permanent deformation greater than

1-inch shall be remediated. Where subgrade remediation is needed in slab on grade and pavement areas, the type of remediation and the depth needed should be determined at the time of construction based on drainage, weather and soil conditions. The following options may be considered for subgrade soil correction.

Page 5 M20068-10

Mechanical Stabilization: Areas of subgrade remediation could be reworked to correct the moisture content and recompacted in accordance with the project specification. If the underlying soil becomes soft and unstable due to presence of water and existing soil cannot be recompacted, localized soft areas may require bridging of the unstable weak soils to facilitate construction.

Bridging can be accomplished with the use of thick layers of granular engineered fill. If open-graded aggregate layers are used for subgrade replacement, we recommend a geotextile fabric be placed to prevent migration of fine soil particles into the layer.

Geogrid: Removal and replacement or mechanical stabilization can include the placement of a geogrid material with an approved granular fill. Various options of geogrid strength and related thickness of granular fill are available, but the system selected should be designed by an experienced contractor or geogrid supplier based on the site soil conditions. By using a geogrid, the soil excavation and replacement depth can be reduced.

Removal and Replacement: Removal and replacement of the soft or unstable soils can be performed and replaced with similar suitable material that exists in the other areas of the subgrade or replaced with engineered fill. The new engineered fill shall be compacted in lifts consistent with the recommendations of this report and to a density of not less than 95 percent of the maximum dry density as determined by ASTM D1557.

Site grading should direct runoff away from the planned building slab on grade and pavement areas, and should be maintained throughout construction so that the potential for softening of the subgrade soils is reduced. Equipment and working traffic should also be kept to a minimum on subgrade surfaces, especially during times of precipitation or following spring thaw. The contractor is responsible for maintaining completed earthwork areas. Consideration should be given to installing construction roads or utilizing the existing pavement for construction traffic to reduce disturbance to the subgrade soils.

As a general rule for new fill placement, the fill materials shall be constructed in lifts as established in control strip. However, the lift thickness should not be less than 6 inches nor more than 12 inches of compacted thickness. The material in each lift shall be within ±2% of optimum moisture content before rolling to obtain the prescribed compaction. Engineered fill placed within the building pad, below foundations or in the pavement subgrade/base course should be compacted to a minimum of 95% of the modified Proctor dry density value. Structural soil fill should be placed a minimum of five feet beyond the edges of the new building and pavement areas, and an additional foot horizontally for each vertical foot of new fill to be placed to provide adequate lateral confinement. The inorganic site soils free of any construction debris that would be removed from excavations could be reused as structural fill; however, moisture conditioning of the material may be necessary.

The information presented in this report may be used to evaluate the site conditions for construction, but the contractor is responsible for determining site preparation means and methods required to complete the project. An aggressive construction schedule or construction during seasons with limited drying time may not allow for reconditioning of the subgrade and soil correction may require removal and replacement with imported granular fill or use of geogrid with granular fill.

Page 6 M20068-10

4.2 FOUNDATION RECOMMENDATIONS

4.2.1 SHALLOW FOUNDATIONS

The proposed buildings can be supported on a typical shallow spread/strip footing system designed for a maximum net allowable soil bearing pressure of 2,000 pounds per square foot (psf) provided the recommendations in this report are followed. Spread foundations designed for a maximum net allowable soil bearing capacity of 2,000 psf should be supported by the native sand soils with a minimum N-value of 8 blows per foot or new engineered fill placed over the recommended sand soil.

Table 4-1 provides the depths at each of the test boring locations to the soil recommended for an allowable bearing capacity of 2,000 psf.

Table 4-1: Recommended Excavation Depths

Boring

Location

Existing Surface

Ground Elevation (ft)

Estimated Depth to 2,000 psf

Allowable Bearing Capacity (ft)

Depth (ft) Elevation (ft)

B-6 856.2 3.7 852.5

B-7[1] 860.3 11.5 848.8

[1] B-7 was drilled on a 4-foot topsoil pile.

Where unsuitable soils are encountered at the foundation elevation, soil correction should consist of additional excavation to remove the unsuitable soils. If the over-excavation is being filled with engineered fill, we recommend the over-excavation be widened at a minimum 1H:1V ratio from the edge of the foundation. The over-excavation can then be filled to grade with suitable engineered fill consisting of a well graded granular material placed in lifts not exceeding 12 inches and compacted to at least 95% of the maximum dry density as determined by the modified Proctor

(ASTM D1557). Alternatively, lean concrete with a minimum compressive strength of 500 psi could be used to fill the over-excavation to grade and lateral over-excavation will not be required.

The excavation depths listed above may be difficult due to the existing groundwater encountered and potential proximity to the existing structure. As over-excavations of individual foundation could be extensive, the project could consider mass excavation of the entire building area to remove the existing fill, expose suitable bearing material, and place engineered fill to design elevations. If the mass excavation option is performed, then over-excavation of individual foundations would not be required.

The depth of excavation required to expose suitable bearing material may vary in areas not explored by GESTRA; therefore, we recommend the foundation excavations be reviewed by a geotechnical engineer or their designated representative to determine when soil suitable to support the recommended bearing capacity is observed.

The shallow foundation design should incorporate a minimum strip footing width of 18 inches and column pad width of 24 inches, even if the allowable bearing capacity has not been fully utilized.

All foundations should bear a minimum of 48 inches below grade for heated structures and 60

Page 7 M20068-10 inches for unheated structures in order to protect the structure from frost heave. We recommend that foundations also be suitably reinforced in order to compensate for the effects of minor differential movements due to subsurface soil variations.

If the recommendations as stated in this report are used in the design and construction of the proposed buildings, it is our opinion that total settlements will be less than 1 inch. It should be noted that the current design for the Munitions Maintenance and Inspection building will not have earth embankment on the exterior side of the building. If the design changes to include earth embankment fill this will result in additional loading on the foundation and soils below, which will result in additional settlement. Therefore, if earth fill is placed behind the exterior wall, similar to the existing buildings to the northwest, the recommendations in this report should be reviewed and updated to account for the additional loading from new fill.

If the project team decides that either over-excavation or mass excavation is not feasible, the project could support the building on either aggregate piers or helical piers. The below sections provide a summary for each option.

4.2.2 AGGREGATE PIERS

As an alternative to a shallow foundation design, compacted aggregate piers could be used beneath the building foundations to eliminate the need for over-excavation. In addition, aggregate piers could likely provide a higher bearing capacity.

In general, aggregate piers consist of drilling a hole into suitable bearing soil and backfilling the excavation with crushed stone in lift and compacting each lift using a crane-suspended downhole vibrator to densify the stone. Aggregate pier system will generate spoil; however, alternate displacement systems are available that can be installed without generating spoil. The evaluation of the soil conditions along with the specific design is typically provided by a specialty contractor and the soil conditions may require unique construction methods beyond the general description provided above.

A more in depth cost analysis should be performed by a specialty contractor to determine if the cost of aggregate piers will result in an overall lower project cost. The specialty contractor should also determine if vibrations from installing the aggregate piers will affect any nearby utilities or buildings.

4.2.3 HELICAL PIERS

A helical pier foundation system can be considered as a deep foundation system to support the building. Helical piers would eliminate the need to over-excavation and possibly the need for dewatering. Helical piers consist of a solid steel plate or plates (helical plate) attached at the lower end of a steel shaft. The piers are turned into the ground to suitable soils until the necessary resistance is met to provide the designed bearing strength. The design loads will dictate the shaft length and configuration of the helical piers. Therefore, the design should be reviewed once the loads for the building have been better defined.

4.3 FLOOR SLAB RECOMMENDATIONS

Assuming the building pad is prepared according to the recommendations in this report, we recommend that a subgrade reaction modulus of 100 pounds per square inch per inch of deflection

(pci) be used in the design of the floor slab at grade. The modulus value is based on the inorganic clay or sand below the existing topsoil, assumes a 1-foot plate is used to determine the modulus

Page 8 M20068-10 and should be adjusted for the size of the foundation and confinement effect. A higher subgrade modulus value could be provided if the mass excavation option is performed.

We recommend that the floor slabs be suitably reinforced and designed to be separate from the foundation system in order to allow for separate movements. It is recommended that the structural engineer specify the floor slab thickness, reinforcing, joint details and other parameters. At a minimum, the floor slabs are recommended to be reinforced or the concrete contain an appropriate fiber mesh additive to help control shrinkage cracking.

We recommend the installation of a capillary moisture break directly below the slab. A typical capillary moisture break may consist of at least 6 inches of sand or gravel with a maximum particle size of 1-1/2 inch, containing 15-55% passing the number 4 sieve and no more than 12% passing the number 200 sieve (fines) and should follow the recommendations of ACI 302.1R-15, Chapter

6. The structural engineer, architect, or manufacturer of a floor covering should determine the need of a vapor barrier, specify the vapor barrier location and consider the concrete curing and the effects of moisture on future flooring materials or building end use. If a vapor retarder is used, we recommend it be placed in accordance with ACI 302.1 Section 3.2 and should meet the requirements of ASTM E1745. The vapor retarder should include proper sealing at penetrations, overlap at joints, and sealing at the interface of the wall and slab and may require an adequate cushion material to prevent damage.

Our recommendations assumed the floor elevation will not approach the water levels encountered in our borings. If the design elevation is near the groundwater encountered, our recommendations should be reviewed and a below slab drainage system may be required.

4.4 SEISMIC SITE CLASSIFICATION

Section 1613 of the International Building Code 2015 (IBC) was used to assign a soil site classification. Based on the native soil conditions observed and assuming these are consistent or better to a depth of 100 feet, the soil site classification D (stiff soil) should be used in the structural design of the proposed building. Based on site class D, and mapped spectral response acceleration

Ss and S1 for Madison, Wisconsin, the site coefficient Fa and Fv are 1.6 and 2.4, respectively.

4.5 PAVEMENT DESIGN

SOIL PARAMETERS FOR PAVEMENT DESIGN

From an evaluation of the subsurface conditions, FAA AC No.: 150/5320-6F, and FAA AC No.:

150/5370-10H, we recommend that the specific pavement design values outlined below be used in establishing the appropriate pavement section(s) for the project.

The parameters in Table 4-2 assume soil subgrade preparation has been performed as identified in this report and are based on Unified Soil Classification System (USCS) classification of sandy lean clay (CL). Table 4-2 provides the recommended soil parameters for the design of the pavement section.

Page 9 M20068-10

Table 4-2: Estimated Average Soil Parameters

Design Parameters

USCS Soils Classification CL

Laboratory CBR value b, (%) 10.5

Frost Group Index b F-4

Frost Penetration depth c, (Inches) 60

Maximum Dry Density d, (pcf) 127.3

Optimum Moisture Content d, (%) 9.0

Poisson’s Ratio e 0.35

Modulus of Subgrade Reaction f (k) (pci) 175

Elastic Modulus of Subgrade for Flexible Pavement g (E), (psi) 15,750 a Based on FAA AC No.: 150/5320-6F, Chapter 3. Section 3.14.4 b Based on FAA AC No.: 150/5320-6F, Chapter 2. Section 2.7.1, Table 2-2 c Based on Hammerpedia website, Wisconsin Frost Line (https://www.hammerpedia.com/wisconsin-frost-line/) d Based on Proctor test performed on the auger cuttings collected from upper 5 feet of borings.

e Based on FAA AC No.: 150/5320-6F, Chapter 3. Section 3.12.11, Table 3-2 f Estimated using empirical formula per FAA AC No.: 150/5320-6F, Chapter 3. Section 3.14.4.

g Estimated using empirical formula per FAA AC No.: 150/5320-6F, Chapter 2. Section 2.5.3.

DISCUSSION OF SEASONAL FROST

The airport is located in a seasonal frost area. The design of an airport pavement should address the adverse effects of seasonal frost. Per FAA AC No: 150/5320-6F, Section 3.12.15, the design of pavement can be based on either of two approaches: Frost Protection or Reduced Subgrade

Strength (RSS). Due the anticipated subgrade soils consisting clay with a plasticity index value of

12 or less, it is recommended that Frost Protection be performed.

Complete Frost Protection and Limited Subgrade Frost Protection are described in FAA AC No:

150/5320-6F, Sections 3.12.16 and 3.12.17. Complete Frost Protection will consist of either providing a sufficient thickness of pavement and non-frost-susceptive material to totally contain frost penetration within the pavement structure (Section 3.12.16.1) or the removal of a considerable amount of existing subgrade material and replacing it with a non-frost susceptible material (Section 3.12.16.2). For estimating purposes it can be assumed that the upper 39 inches of soil will need to be removed. A frost susceptible material may consist of gravel with less than

20 percent of soil finer than 0.02 mm or sand with less than 5 percent of soil finer than 0.02 mm.

Per FAA AC No: 150/5320-6F, Section 3.12.17, Limited Subgrade Frost Protection, is used if there is an acceptable level of maintenance related to frost heave. Frost is allowed to penetrate a limited amount into the frost susceptible subgrade. If the non-frost susceptible section is less than

65 percent of the frost penetration or 39 inches, additional frost protection is required.

Page 10 M20068-10

SUBSURFACE DRAINAGE

One of the important considerations in designing a high quality and durable pavement is providing adequate drainage. Drainage design for the proposed pavement section is out of GESTRA’s scope for this project. Subsurface drainage is discussed in Appendix G of FAA AC No. 150/5320-5D

Airport Drainage Design dated May 13, 2013. The effectiveness of subsurface drainage will be impacted by the site groundwater.

4.6 SOIL CORROSIVITY

GESTRA completed Miller Box resistivity and pH testing on samples collected from the upper 5 feet of borings B-6 and B-7. In addition, GESTRA subcontracted Testing Engineers International, Inc. to complete sulfate testing on a sample collected from B-6 and B-7. Table 4-3 provides a summary of the test results, and detailed results are included in Appendix II.

Table 4-4: Summary of Laboratory Testing (Corrosivity)

Sample

Number Soil Type Test Test Method Results

B-7, SS-6 Sand Resistivity

(Miller Box) G187 12,760 Ω*cm

B-6, SS-2 Clay pH

D4972 8.14

B-7 SS-6 Sand G51 8.5

B-6, SS-2 Clay Sulfate C1580

< 0.1 percent by mass

B-7, SS-6 Sand < 0.1 percent by mass

Based on the results from the electrical resistivity testing and Table 2-3 in the FHWA NHI-09-

087, the existing onsite soils are Non-corrosive.

The sulfate content determined for the sample was compared to the values in Table 19.3.1.1 of

ACI 318R. Based on this table, the soil samples test are categorized as “Exposure Class S0” and injurious sulfate attack is not a concern.

4.7 CONSTRUCTION CONSIDERATIONS

The detailed means and method of excavation and construction should be decided by the contractor and approved by the project design team. Based on the specific site information, geotechnical exploration results and requirements for the proposed building and pavement, the following issues should be taken in consideration during construction.

Dewatering

Based on the soil borings performed, substantial water will likely be encountered where deeper excavations are required, or excavations deeper than the water levels encountered in our borings.

As for areas which will not require deep excavations, less than 4 feet, substantial water is not anticipated to be encountered. If water is encountered during the shallow excavations, we anticipate the appropriate number of temporary sump pits and pumps should be sufficient to

Page 11 M20068-10 remove water in the excavation. If excavations are anticipated to extend below elevation 852 feet, a formal dewatering plan should be prepared so that the groundwater level is maintained to a depth of 2 feet below the excavation. The formal dewatering plan should also address the effects of lowering the groundwater table will have on nearby structures. The contractor should also be prepared to control water from surface run-off and rain, and prevent it from accumulating in excavations or otherwise affecting construction.

Excavation Stability

Caving is a common issue for excavation side walls during construction, especially if fill material, granular soils, and/or water seepage are observed. An excavation plan should be developed and the length of excavation left open should be limited to prevent caving soil from covering the suitable bearing soils.

A temporary soil retention system may also be necessary in order to prevent caving or provide support of surrounding structures or utilities during construction. Providing recommendations or designing the retention system is out of the scope for GESTRA. The contractor must comply with the federal, state, local and updated OSHA regulations during excavation and in retention system design to ensure excavation safety and a retention system should consider the site groundwater in the design.

Occupational Safety and Health Act (OSHA) has instituted strict standards for temporary construction excavations. These standards are outlined in 29 CFR Part 1926 Subpart P.

Excavations within unstable soil conditions or extending five feet or more in depth should be adequately sloped or braced according to these standards. Excavation safety is the responsibility of the contractor. Material stockpiles or heavy equipment should not be placed near the edge of the excavation slopes. The actual stable slope angle should be determined during construction and will depend upon the loading, soil, and groundwater conditions encountered.

Weather Implications

The subgrade soil or the soil at foundation level might become unstable with exposure to adverse weather such as rain, snow and freezing temperatures. The unstable areas due to weather exposure may require an additional undercut or stabilization and the representative geotechnical engineer should assist with the determination of the depth of additional undercut or stabilization procedure based on observation of the field condition.

Soil Sensitivity

Soil at the construction site will be exposed to moisture and disturbance from construction traffic, construction equipment and human factors. Due to the disturbance, soil may become sensitive with contact of water. Contractor should try to lessen the exposure the soil at the construction site may encounter to moisture and disturbances. Therefore, the foundations, floor slabs and pavements should be constructed immediately after the review of the representative geotechnical engineer.

Existing Adjacent Structures

New construction near or adjacent to existing foundations and structures requires special consideration. Due to potential interaction between new and existing foundations and slab on grade pads and overlapping stresses from adjacent foundations, the existing buildings may experience

Page 12 M20068-10 some settlement. The effect of these stresses and potential settlement should be evaluated prior to finalizing the design.

Where new slab on grade pads or foundations are planned adjacent to existing spread foundations, the effects of overlapping soil stresses must be considered and the maximum net allowable soil bearing pressure must not be exceeded. The excavation and new construction should also consider the potential impact on the existing deep foundations. A temporary soil retention system may also be necessary to avoid undermining the existing building or other adjacent structures. The contractor and design team should consider the impact of the planned construction on any adjacent structures or utilities and should develop a plan of construction to mitigate impact. Evaluation of any adjacent structures or utilities or the effect of the construction on adjacent structures or utilities is outside the scope of GESTRA’s services for this project. The project may also want to consider a pre and post condition survey to identify pre-existing distress of the structures adjacent to the planned construction and a monitoring plan during construction.

Existing Fill

The depth and type of existing fill material varied between our borings. Excavating, handling and disposing existing fill material may have special requirements. GESTRA has not evaluated the material or groundwater with respect to environmental considerations.

5.0 EXPLORATION AND TESTING PROCEDURES

5.1 LAYOUT AND ELEVATION PROCEDURES

A total of two (2) soil borings were completed at the locations shown on the attached Borehole

Location Map in Appendix I. The location of the borings were selected by Hanson and located in the field by GESTRA.

Elevation of boreholes were obtained by GESTRA using a Geomax Zenith 35 GNSS-INS receiver.

Elevations shown on the boring logs are referenced to the Wisconsin Carrier Registration System

(WisCRS) Dane County (NAVD88). Coordinates and elevation were not obtained by a licensed surveyor.

5.2 FIELD TESTING PROCEDURES

The boreholes were drilled using a track mounted drill rig. The boreholes were initiated and advanced by using hollow stem augers. Samples were collected at 2-1/2-foot intervals to a depth of 16 feet and then at 5-foot intervals. All representative soil samples were taken in general accordance with the “Standard Method for Penetration Test and Split-Barrel Sampling of Soils”

(ASTM D1586). After each sampling, a soil sample was retained and placed in a jar and recorded for type, color, consistency, and moisture, sealed and then transported to the laboratory for further review and testing, if required. The specific drilling method used including the depth, rig type, and crew chief, are included on each of the individual boring logs as it may change for each borehole.

5.3 LABORATORY TESTING PROCEDURES

After completion of drilling operations, all of the retained soil samples were transported to

GESTRA’s laboratory and classified by a geotechnical engineer using the Unified Soil

Classification System (USCS). A chart describing the classification system used is included in

Appendix I. The engineer assigned laboratory testing suited to extract important index properties of the soil layers. These tests included hand penetrometer, moisture and organic content, Atterberg

Page 13 M20068-10 limit, P200, modified Proctor, CBR, pH, resistivity using Miller box and sulfate. The methods used are presented on the individual lab forms.

Page 14 M20068-10

STANDARD OF CARE

Our exploration was limited to evaluating subsurface soil and groundwater conditions pertaining to the proposed project. GESTRA did not perform any environmental, chemical, or hydrogeologic testing as these were not part of our work scope.

This report should be made available in its entirety to bidding contractors for information purposes.

The soil borings and site sketch should not be detached from this report. Our report is not valid if used for purposes other than what is described in the report.

All OSHA regulations such as those regarding proper sloping and temporary shoring of excavations should be followed during the entire construction process.

GESTRA has presented our professional opinions in this report in the form of recommendations.

Our opinions are based on our understanding of current project information and related accepted engineering practices at the time of this report. Other than this, no warranty is implied or intended.

Sincerely, Report Prepared By: Report Reviewed By:

Eric Jeske, P.E. Douglas Dettmers, P.E.

Staff Engineer Senior Engineer

Digitally signed by Eric Jeske

Date: 2020.12.01 09:13:48 -06'00' Digitally signed by Douglas Dettmers

Date: 2020.12.01 09:14:51 -06'00'

M20068-10

APPENDIX I

SITE LOCATION MAP, BOREHOLE LOCATION MAP, TEST BORING LOGS, GENERAL NOTES AND

SOILS CLASSIFICATION

191 W. Edgerton Avenue Milwaukee, WI 53207

Project Name & Location:

Truax Beddown Projects

Truax Air Field

Phone: (414) 933-7444 Fax: (414) 933-7844

Checked by: DD

Date: October 23, 2020

Madison, Wisconsin

Scale: Not to Scale

Drawing Title:

Site Location Map

Drawing No.: 1 of 1

Project No.: M20064-10

Prepared by: EJ

XGFG182017

XGFG182006

XGFG182018

XGFG182002

XGFG182009

NORTH

NA

191 W. Edgerton Avenue Milwaukee, WI 53207

Project Name & Location:

Truax Beddown Projects

XGFG182017

Phone: (414) 933-7444 Fax: (414) 933-7844

Checked by: DD

Date: October 23, 2020

Madison, Wisconsin

Scale: 1” = 80’

Drawing Title:

Borehole Location Map

Drawing No.: 1 of 1

Project No.: M20068-10

Prepared by: EJ

= Approximate Borehole Location

B-6

= Approximate Borehole Location

B-7

N

Base map obtained from Dane County GIS website

2.00

TOPSOIL (24")

2 (854.2) LEAN CLAY, gray with brown mottles, moist, very stiff

3.7 (852.5) SAND, brown, wet, loose to medium dense

Color change to gray at 7'

11 (845.2) End of Boring at 11.0 ft.

S S

-1 S

S -2

S S

-3 S

S -4

S S

-5

CL

SP

DATE DRILLING ENDED

PROJECT NAME

PROJECT LOCATION

SURFACE ELEVATION

Li qu id L im it

Madison, WI

U S

C S

C la ss ifi ca tio n

BORING DRILLED BY

B-6

N

V al ue

CAVE DEPTH AT COMPLETION (ft): NMR

WATER LEVEL AT COMPLETION (ft): NMR

CAVE DEPTH AT COMPLETION (ft): NMR

S am pl e

N um be r an d

T yp e

WATER ENCOUNTERED DURING DRILLING (ft): 4.5 ft.

WATER LEVEL AFTER 0 HOURS (ft): NMR

10/13/2020

FIELD LOG

Comments

WET

DRY

G ra ph ic

Soil Description and Geological Origin for

Each Major Unit

NE = Not Encountered; NMR = No Measurement Recorded

NORTHING

PROJECT NUMBER

504795

LAB LOG / QC

S am pl e

R ec ov er y (in

856.2 ft

SOIL BORING LOG

NOTE: Stratification lines between soil types represent the approximate boundary; gradual transition between in-situ soil layers should be expected.

PAGE NUMBER

WET

DRY

U nc on fin ed C om p.

S tr en gt h (Q u o r Q p) ts f)

M oi st ur e C on te nt

DATE DRILLING STARTED

B lo w C ou nt s

W el l D ia gr am

WATER & CAVE-IN OBSERVATION DATA

EASTING

833979

Diedrich D50 ATV

10/13/2020

P la st ic ity In de x

CAVE DEPTH AFTER 0 HOURS (ft): NMR

851.2

846.2

841.2

836.2

831.2

DRILLING RIG

DRILLING METHOD

D ep th ft)

E le va tio n

E. Jeske

M20068-10

BORING NUMBER

K. TurnerFIRM: Gestra CREW CHIEF: S. Gonyer

Truax Beddown Facility

3¼" HSA

GESTRA Engineering Inc.

2223 Industrial Drive

Phone: 608-222-9406, Fax: 608-222-9408

TOPSOIL

5.2 (855.1) SAND, light gray, moist, with bluish gray clay seams, (FILL)

Wet at 9.5'

11.5 (848.8) SAND, brown, wet, loose, trace gravel

13.8 (846.5) SAND WITH SILT, gray, wet, medium dense

With silt in sample SS-8

Boring was drilled on a topsoil pile.

Moisture content ran on clay seam

P200 = 8.7%

S S

-1 S

S -2

S S

-3 S

H -4

S S

-5 S

S -6

S S

-7 S

S -8

S S

-9

SP

SP-SM

DATE DRILLING ENDED

PROJECT NAME

PROJECT LOCATION

SURFACE ELEVATION

Li qu id L im it

Madison, WI

U S

C S

C la ss ifi ca tio n

BORING DRILLED BY

B-7

N

V al ue

CAVE DEPTH AT COMPLETION (ft): NMR

WATER LEVEL AT COMPLETION (ft): NMR

CAVE DEPTH AT COMPLETION (ft): NMR

S am pl e

N um be r an d

T yp e

WATER ENCOUNTERED DURING DRILLING (ft): 9.5 ft.

WATER LEVEL AFTER 0 HOURS (ft): NMR

10/13/2020

FIELD LOG

Comments

WET

DRY

G ra ph ic

Soil Description and Geological Origin for

Each Major Unit

NE = Not Encountered; NMR = No Measurement Recorded

NORTHING

PROJECT NUMBER

504856

LAB LOG / QC

S am pl e

R ec ov er y (in

860.3 ft

SOIL BORING LOG

NOTE: Stratification lines between soil types represent the approximate boundary; gradual transition between in-situ soil layers should be expected.

PAGE NUMBER

WET

DRY

U nc on fin ed C om p.

S tr en gt h (Q u o r Q p) ts f)

M oi st ur e C on te nt

DATE DRILLING STARTED

B lo w C ou nt s

W el l D ia gr am

WATER & CAVE-IN OBSERVATION DATA

EASTING

834047

Diedrich D50 ATV

10/13/2020

P la st ic ity In de x

CAVE DEPTH AFTER 0 HOURS (ft): NMR

855.3

850.3

845.3

840.3

835.3

DRILLING RIG

DRILLING METHOD

D ep th ft)

E le va tio n

E. Jeske

M20068-10

BORING NUMBER

K. TurnerFIRM: Gestra CREW CHIEF: S. Gonyer

Truax Beddown Facility

3¼" HSA

GESTRA Engineering Inc.

2223 Industrial Drive

SAND WITH SILT, gray, wet, medium dense

With silt in sample SS-10

31 (829.3) End of Boring at 31.0 ft.

S S

-1

SP-SM

DATE DRILLING ENDED

PROJECT NAME

PROJECT LOCATION

SURFACE ELEVATION

Li qu id L im it

Madison, WI

U S

C S

C la ss ifi ca tio n

BORING DRILLED BY

B-7

N

V al ue

CAVE DEPTH AT COMPLETION (ft): NMR

WATER LEVEL AT COMPLETION (ft): NMR

CAVE DEPTH AT COMPLETION (ft): NMR

S am pl e

N um be r an d

T yp e

WATER ENCOUNTERED DURING DRILLING (ft): 9.5 ft.

WATER LEVEL AFTER 0 HOURS (ft): NMR

10/13/2020

FIELD LOG

Comments

WET

DRY

G ra ph ic

Soil Description and Geological Origin for

Each Major Unit

NE = Not Encountered; NMR = No Measurement Recorded

NORTHING

PROJECT NUMBER

504856

LAB LOG / QC

S am pl e

R ec ov er y (in

860.3 ft

SOIL BORING LOG

NOTE: Stratification lines between soil types represent the approximate boundary; gradual transition between in-situ soil layers should be expected.

PAGE NUMBER

WET

DRY

U nc on fin ed C om p.

S tr en gt h (Q u o r Q p) ts f)

M oi st ur e C on te nt

DATE DRILLING STARTED

B lo w C ou nt s

W el l D ia gr am

WATER & CAVE-IN OBSERVATION DATA

EASTING

834047

Diedrich D50 ATV

10/13/2020

P la st ic ity In de x

CAVE DEPTH AFTER 0 HOURS (ft): NMR

830.3

825.3

820.3

815.3

810.3

DRILLING RIG

DRILLING METHOD

D ep th ft)

E le va tio n

E. Jeske

M20068-10

BORING NUMBER

K. TurnerFIRM: Gestra CREW CHIEF: S. Gonyer

Truax Beddown Facility

3¼" HSA

GESTRA Engineering Inc.

2223 Industrial Drive

GESTRA Engineering, Inc server_share\report\10-geotechnical\General Notes.doc

GENERAL NOTES

DRILLING AND SAMPLING SYMBOLS TEST SYMBOLS

SYMBOL

HSA

RWB

_FA

_HA

_DC

_RC

PD

CS

DM

JW

SS

_L

ST

3TP

_TO

W

B

P

_Q

_X

CR

NSR

NMR

DEFINITION

Hollow Stem Auger

Rotary Wash Boring (Mud Drilling)

4”, 6” or 10” Diameter Flight Auger

2”, 4” or 6” Hand Auger

2 1/2” , 4” , 5” or 6” Steel Drive Casing

Size A, B, or N Rotary Casing

Pipe Drill or Cleanout Tube

Continuous Split Spoon Sampling

Drill Mud

Jetting Water

2” O.D. Split Spoon Sample

2 1/2” or 3 1/2” O.D. SB Liner Sample

3” Thin Walled Tube Sample (Shelby Tube)

3” Thin Walled Tube (Pitcher Sampler)

2” or 3” Thin Walled Tube (Osterberg Sampler)

Wash Sample

Bag Sample

Test Pit Sample

BQ, NQ, or PQ Wireline System

AX, BX, or NX Double Tube Barrel

Core Recovery – Percent

No Sample Recovered, classification based on action of drilling, equipment and/or material noted in drilling fluid or on sampling bit.

No Measurement Recorded, primarily due to presence of drilling or coring fluid.

Water Level Symbol

SYMBOL

MC

OC

DD

LL, PL

DEFINITION

Moisture Content - % of Dry Wt. – ASTM D 2216

Organic Content - % of Dry Wt. – ASTM D 2974 Dry Density – Pounds Per Cubic Foot

Liquid and Plastic Limit – ASTM D 4318

Additional Insertions

Qu

Qp

Ts G

SL

OC

SP

PS

FS

pH

SC

CC

C*

Qc*

D.S.* K*

D*

DH*

MA*

R E*

PM*

VS*

IR*

RQD

Unconfined Comp. Strength-psf – ASTM D 2166

Penetrometer Reading – Tons/Square Foot

Torvane Reading – Tons/Square Foot Specific Gravity – ASTM D 854

Shrinkage Limits – ASTM D 427

Organic Content – Combustion Method Swell Pressure - Tons/Square Foot

Percent Swell

Free Swell – Percent Hydrogen Ion Content. Meter Method

Sulfate Content – Parts/ Million, same as mg/L

Chloride Content - Parts/ Million, same as mg/L One Dimensional Consolidation – ASTM D 2453

Triaxial Compression

Direct Shear – ASTM D 3080 Coefficient of Permeability – cm/sec

Dispersion test

Double Hydrometer – ASTM D 4221 Particle Size Analysis – ASTM D 422

Laboratory Receptivity, in ohm – cm – ASTM G 57 Pressuremeter Deformation Modulus – TSF

Pressuremeter Test

Field Vane Shear – ASTM D 2573 Infiltrometer Test – ASTM D 3385

Rock Quality Designation – Percent

*See attached data sheet or graph

WATER LEVEL

Water levels shown on the boring logs are the levels measured in the borings at the time and under the conditions indicated. In sand, the indicated levels may be considered reliable ground water levels. In clay soil, it may not be possible to determine the ground water level within the normal time required for test borings, except where lenses or layers of more pervious waterbearing soil are present. Even then, an extended period of time may be necessary to reach equilibrium. Therefore, the position of the water level symbol for cohesive or mixed texture soils may not indicate the true level of the ground water table. Perched water refers to water above an impervious layer, thus impeded in reaching the water table. The available water level information is given at the bottom of the log sheet.

DESCRIPTIVE TERMINOLOGY

DENSITY

TERM

Very Loose

Loose

Medium Dense Dense

Very Dense

“N”

VALUE

0-4

4-10

10-30 30-50

Over 50

CONSISTENCY

TERM

Very Soft

Soft Medium Stiff

Stiff

Very Stiff

Hard

Unconfined

Compressive

Strength, (tsf)

<0.25

0.25 - 0.49

0.5 - 0.99

1.0 - 1.99

2.0 - 3.99

4.0+

“N”

VALUE

0-2

2-4 4-8

8-16

16-30

Over 30

Lamination

Layer Lens

Varved

Dry Moist

Wet

Water bearing

Up to 1/2” thick stratum

1/2” to 6” thick stratum 1/2” to 6” discontinuous stratum

Alternating laminations

Powdery, no noticeable water Below saturation

Saturated, above liquid limit

Pervious soil below water

Standard “N” Penetration: Blows per Foot of a 140 Pound Hammer

Falling 30 inches on a 2 inch OD Split Barrel

Sampler

RELATIVE GRAVEL PROPORTIONS RELATIVE SIZES

CONDITION

Coarse Grained Soils

Fine Grained Soils 15-29% + No. 200

15-29% + No. 200

30% + No. 200

30% + No. 200

30% + No. 200

TERM

trace of gravel with gravel trace of gravel with gravel trace of gravel with gravel gravelly

RANGE

2-14%

15-49%

2-14%

15-29%

2-14%

15-24%

25-49%

Boulder Cobble

Gravel

Coarse Fine

Sand

Coarse Medium

Fine

Silt & Clay

Over 12” 3” - 12”

3/4” - 3” #4 – 3/4”

#4 - #10 #10 - #40

#40- #200

- # 200, Based on Plasticity

Group

Symble

Coarse-Grained Soils Gravels Clean Gravels Less than 5% fines C

Cu≥ 4 and 1≤ Cc ≤3 E GW Well graded gravel

F

More than 50% retained on More than 50% coarse Less than 5% fines C

Cu< 4 and/or 1> Cc >3 E GP Poorly graded gravel

F

No. 200 sieve fraction retained on Gravels with Fines

More than 12% fines C

GM Silty gravel F.G.H.

No. 4 sieve more than 12% fines C GC Clayey gravel

F.G.H.

Sands Clean sands Cu≥ 6 and 1≤ Cc ≤3 E SW Well graded sand

I

50% or more of coarse Less than 5% fines D

Cu< 6 and/or 1> Cc >3 E SP Poorly graded sand

I fraction passes No. Sands with Fines

More than 12% fines D

SM Silty sand G.H.I

4 sieve more than 12% fines D SC Clayey sand

G.H.I

Fine-Grained Soils Silts and Clays inorganic PI >7 and plots on or above

50% or more passes the Liquid Limit less than 50 " A" line

No. 200 sieve PI<4 or plots below " A " line organic OL Organic clay K.L.M.N

Organic Silt K.L.M.O

Silts and Clays inorganic PI plots on or above " A " line CH Fat clay K.L.M

Liquid Limit 50 or more PI plots below " A " line MH Elastic silt K.L.M

Organic OH Organic clay K.L.M.P

Organic Silt K.L.M.Q

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

Fibric Peat > 67% Fibers Hemic Peat 33 % - 67 % Fibers sapric Peat < 33% Fibers

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

E ( D30 ) 2 J

If Atterberg limits plot in hatched area, soil is a CL_ML

B If field sample contained cobbles or boulders, or both. add D10 x D60 silty clay with cobbles or boulders, or both to group name If soil contains 15 to 29% plus No. 200, add, "with sand"

C Gravels with 5 to 12 % fines require dual symbols:

F If soil contains ≥ 15% sand, add "with sand" to group or " with gravel", whichever is predominent

GW - GM well-graded gravel with silt name L If soil contains ≥ 30% plus No.200, predominantly sand, GW - GC well-graded gravel with clay G

If fines classify as CL-ML, use dual symbol GC-GM. or add "sandy" to the group name

GP - GM poorly-graded gravel with Silt SC-SM M If soil contains ≥ 30% plus No.200, predominantly

GP - GC poorly-graded gravel with clay H

If fines are…