Attachment 0008 - 2024-3910 - SOW - Appendix G - Geotechnical Report.pdf

Geotechnical Exploration for New ADA Ramp

Quarters One 1940 Gillespie Circle

Rock Island Arsenal, Illinois

January 10, 2025 IMEG No. 24007322.00

Appendix G

January 10, 2025

Tunista Logistic Solutions, LLC 3050 Rodman Avenue, Building 102 Rock Island Arsenal, Illinois

ATTN: Mr. Matt McComb P: 309.781.2194

E: Matthew.McComb@yulista.com

RE: Geotechnical Exploration for New ADA Ramp Quarters One 1940 Gillespie Circle Rock Island Arsenal, Illinois

IMEG No. 24007322.00

Mr. McComb:

The recently completed geotechnical study for planning, design, and future construction of a New ADA Ramp at the above address in Rock Island, Illinois is submitted herewith.

The report presents the results of field and laboratory testing of soils and geotechnical recommendations for the planned construction. We hope the findings and recommendations are helpful with planning for design and construction activities. We invite you to call if you require clarification or further discussion of any items presented herein.

Respectfully Submitted, IMEG Consultants Corp.

I hereby certify that this report was prepared by me or under my direct supervision and that I am a duly licensed Professional Engineer under the laws of the State of Illinois.

2025.01.10

Signature Date

Matthew A. Dotson

License No. 062-067498

My license renewal date is November 30, 2025

Pages covered by this seal: Geotechnical Report and Appendices A to C

NJL/rma Geotechnical Engineer mailto:Matthew.McComb@yulista.com

GEOTECHNICAL STUDY

New ADA Ramp Quarters One

1940 Gillespie Circle Rock Island Arsenal, Illinois

Table of Contents

1.0 INTRODUCTION

2.0 EXPLORATION AND TESTING PROCEDURES

3.0 SUBSURFACE CONDITIONS

3.1 SOILS DESCRIPTIONS METHODS

3.2 SUMMARY OF SUBSURFACE CONDITIONS

3.3 WATER LEVEL OBSERVATIONS

4.0 ANALYSIS AND RECOMMENDATIONS

4.1 PROJECT INFORMATION

4.2 GEOTECHNICAL CONSIDERATIONS

4.3 SITE PREPARATION AND DRAINAGE

4.4 CONTROLLED FILL

4.5 SHALLOW FOUNDATIONS

4.6 LATERAL EARTH PRESSURES

4.7 SEISMIC SITE CLASSIFICATION

5.0 CLOSING REMARKS

5.1 EXCAVATIONS

5.2 CONSTRUCTION INSPECTION

5.3 STUDY LIMITATIONS

GEOTECHNICAL STUDY

New ADA Ramp Quarters One

1940 Gillespie Circle Rock Island Arsenal, Illinois

January 10, 2025 IMEG No. 24007322.00

1.0 INTRODUCTION

This report presents the results of our geotechnical exploration for planning, design, and future construction of a New ADA Ramp at the above address in Rock Island, Illinois. The report is in general accordance with correspondence between Mr. Matt McComb

(Tunista Logistics) and Mr. Nate Lawson (IMEG-Rock Island). Notice to proceed was provided on November 21st and our exploratory services were executed thereafter. The following table provides a summary of project execution items and milestone dates.

Table A. Project Execution Summary

Item Date Completed

Proposal Date November 11, 2024

Authorization Received November 21, 2024

Field Work Completed December 18, 2024

Geotechnical Report Completed January 10, 2025

Work included a review of available subsurface data for the project area, completion of three hand auger borings to depths ranging from 7.3 to 7.8 feet below the existing ground surface, testing of soil in the field and laboratory, analyses of results, development, and presentation of geotechnical recommendations based on our observations. Appendix A of the report provides a Boring Location Plan showing the approximate location of the borings performed for this study.

2.0 EXPLORATION AND TESTING PROCEDURES

The exploratory borings were advanced manually with a 3.25-inch diameter hand auger.

At levels of interest, dynamic cone penetration testing (DCPT) was performed. The DCPT tests described by ASTM Special Technical Publication 399 were used. During the tests, 15-pound controlled hammer blows fall a distance of 20 inches along a guide rod by gravity and drive a 1-1/2-inch diameter cone-tipped rod a given distance, or increment, of

1-3/4 inches. A count of the blows is made and recorded. The count is an indication of the soil strength or relative density and correlates to the split spoon blow counts (N-values).

Resulting DCPT, or equivalent SPT, blow counts obtained in the field were recorded and provide an index of the soil relative density and strength as shown by Table B.

Table B. Consistency and Relative Density by Blow Count

Cohesive (Clayey) Soils Cohesionless (Sandy) Soils

N-Value (blows/ft.)

Consistency

Approximate Unconfined

Compressive Strength, psf.

N-Value (blows/foot)

Relative Density

0 - 2 Very Soft 0 - 500 0 - 4 Very Loose

2 - 4 Soft 500 - 1000 4 - 10 Loose

4 - 8 Medium Stiff 1000 - 2000 10 - 30 Medium Dense

8 - 15 Stiff 2000 - 4000 30 - 50 Dense

15 - 30 Very Stiff 4000 - 8000 50+ Very Dense

30+ Hard 8000+

Recovered soil samples were sealed in either the direct push sampler or recovered from the manual hand auger bucket, were labeled according to the appropriate boring number and depth of the specimen. Then, samples were protected and were prepared for transport to our laboratory for density measurement, moisture content determination, and strength testing in unconfined compression as appropriate for intact samples. ASTM test methods D2216 and D2166 were closely followed. Test results were recorded on the final boring logs of Appendix B.

3.0 SUBSURFACE CONDITIONS

3.1 SOILS DESCRIPTIONS METHODS

Soil sample grain size, plasticity, and consistency were evaluated by visual-manual methods and the Unified Soil Classification System as outlined in Appendix C. The resulting descriptions were recorded on the boring logs in conjunction with soil colors evident at the time of sample examination. The descriptions were separated by stratification lines but, in place, the change between them is usually more gradual.

3.2 SUMMARY OF SUBSURFACE CONDITIONS

The hand auger borings encountered 2.25 to 4-inch HMA surface cover overlying existing fill and highly weathered limestone. The existing fill was comprised of silty fine-grained sand and sandy clay with red brick fragments and gravel. The existing fill encountered in the borings varied in material composition, consistency, and moisture content. Moistures within the existing fill ranged from 11.6 to 21.0 percent with SPT N-Values on the order of 1 to 17 blows per foot.

By depths of 3.0 to 4.0 feet below the existing ground surface, the existing fill gradually transitioned to native alluvial soils. The native alluvium consisted of Sandy Clay, Silty Fine-

Grained Sand, Lean to Silty Clay, and Silty Clay. SPT N-values within the alluvium varied from 1 to 13 blows per foot while moistures were on the order of 13.2 to 23.7 percent.

The native alluvium extended to depths of 7.2 to 7.7 feet below the existing ground surface.

Beneath the alluvium, highly weathered limestone was discovered. Moistures within the highly weathered limestone ranged upward from 9.5 to 17.3 percent. The highly weathered limestone extended until hand auger refusal was encountered by depths of about 7.3 to 7.8 feet.

A summary of the generalized subsurface conditions for the respective soil layers encountered in the current borings is presented in Table C.

Table C. Summary of Site Stratigraphy

Layer Description Depth to Bottom of

Layer (feet bgs) DCPT N-Value

(blows per foot) Moisture Content

(percent)

HMA Surface 0.2 to 0.3 N/A N/A

FILL 3.0 to 4.0 1 to 17 11.6 to 21.0

Sandy Clay (Alluvium) 5.0 to 6.0 8 to 9 18.4 to 21.3

Silty Fine-Grained Sand (Alluvium) 5.0 to 7.2 1 to 7 13.2 to 19.7

Lean to Silty Clay (Alluvium) 7.5 8 to 9 18.5 to 21.6

Silty Clay (Alluvium) 7.7 13 23.7

Highly Weathered Limestone 7.3+ to 7.8+ 25/1”+ 9.5 to 17.3

The Table C subsurface descriptions are summarized to highlight the major subsurface stratification features and material characteristics within the project borings. The boring logs included in Appendix B should be reviewed for specific information at the boring locations and at depths within the borings. These records include soil descriptions, stratifications, penetration resistances and depths of the respective samples and laboratory test data.

The stratifications shown on the boring logs represent the conditions only at the actual boring locations. Variations often occur and should be expected across the site. The stratifications represent the approximate boundary between subsurface materials and the actual transition may be more abrupt or gradual. Water level information obtained during field operations is also provided on the boring logs and discussed in the following section.

3.3 WATER LEVEL OBSERVATIONS

The soil test borings were monitored for water upon completion of drilling and backfilled shortly after the monitoring period. Ground water accumulations were not readily observed during the limited monitoring period. Please refer to Appendix B boring logs for additional information.

The presence of groundwater may depend on the season, year, and surface drainage patterns. It could vary for reasons not evident at the time of drilling. If more accurate determination of groundwater levels is desired, we recommend installation of a PVC piezometer so that groundwater elevations may be more accurately determined and monitored prior to execution of construction activities. Water can collect in trench backfill new construction grading fill depending on the backfill classification and compaction. The effects of water should be carefully considered.

4.0 ANALYSIS AND RECOMMENDATIONS

The subsurface conditions are analyzed in conjunction with the available project information and the geotechnical recommendations depend on the amount of project information provided. You are invited to discuss the project with us. This will enable us to apply available knowledge of soil conditions to actual design problems, convey impressions, and offer suggestions.

4.1 PROJECT INFORMATION

It is our understanding that construction of a new ADA ramp at Quarters One is being planned. Since the project is in the conceptual stages of design, structural loads for the new ramp are not yet available. Therefore, for the purposes of report preparation and development of recommendations we have assumed the following:

• Maximum concrete ramp live load of 100 pounds per square foot.

• Maximum continuous footing loads of 2 kips per lineal foot.

• Maximum fill depths of five feet relative to existing lines and levels.

If any of the above information is not well aligned with the final design or construction documents, please contact us as our recommendations may be affected.

4.2 GEOTECHNICAL CONSIDERATIONS

The project borings encountered existing fill extending to depths ranging from 3.0 to 4.0 feet below the existing ground surface. The existing fill was comprised of silty fine-grained sand and sandy clay with red brick fragments and gravel. Moistures varied significantly and SPT N-values were inconsistent throughout all three soil borings.

We do not possess the construction materials test reports showing the results of compaction tests before and during the previous site improvements. Therefore, it is necessary to base our evaluation on limited data from the current geotechnical study.

With consideration of in-place moisture contents and the presence of deleterious material for soils encountered in the borings, it is our opinion that the existing fill in its current condition is not desirable for the construction of the ADA Ramp.

In our opinion and given the relatively shallow depth of existing fill present, the existing fill should be completely removed and replaced with new compacted controlled fill.

Based upon the hand augers performed for this project, with the exception of red bricks encountered in boring HA-3, the existing fill appears to satisfy the material requirements of Section 4.4. Any deleterious material (red brick fragments, etc.) should be hauled off-site.

Once the existing fill is removed and replaced (i.e., reused) any loose soils underlying the existing fill should be disked, dried, and recompacted with a walk-behind plate compactor to 98% of its maximum dry density determined by ASTM D698. Very loose to loose silty fine-grained sand was encountered to depths of 7.0 feet in boring HA-3. After disking, drying, moisture conditioning, and recompaction, should these soils not meet the compaction requirements of Section 4.4, they should be removed and replaced with compacted controlled fill as directed by the Geotechnical Engineer.

Once the existing fill and soft-subgrade soils have been addressed, shallow foundation construction may proceed. Recommendations concerning shallow foundations are provided in Section 4.5. Since backfill will be placed within the new ADA ramp walls, the walls will need to be designed to resist lateral earth pressure from the backfill material.

Recommendations addressing lateral earth pressures and seismic site classification are provided in Sections 4.6 and 4.7.

New fill may be required for site grading and excavation backfill. Recommendations regarding site preparation, grading, and selection of Controlled Fill are provided in

Sections 4.3 and 4.4.

4.3 SITE PREPARATION AND DRAINAGE

After the existing pavement is removed and following the successful execution of over-excavation of all the existing fill, the base of all excavations should be examined by a technical representative of IMEG to ensure no other deleterious material, demolition debris, or soft bearing soils remain. Then, new fill meeting the requirements of Section

4.4 may be placed in compacted and controlled lifts. Verification testing throughout placement and compaction activities is recommended.

All grading fill compaction, moisture content, and lift thicknesses should be monitored and verified by a geotechnical representative throughout construction activities. Any damage caused by construction traffic patterns or deterioration due to adverse weather should be repaired to the satisfaction of the Geotechnical Engineer.

Positive surface water management practices must be established throughout the duration of construction activities and extended to the service life of the planned improvements. It is imperative that no water be allowed to accumulate adjacent to or upon any of the planned improvement areas. This requirement of design must be satisfied throughout the entirety of construction and extend to the service life of the planned improvements.

4.4 CONTROLLED FILL

Controlled fill should consist of sand, crushed stone, lean clay, silty clay, or clayey silt having Unified Soil Classifications SM, SW, SP, SC, GM, GW, GC, CL, CL-ML or ML. To inhibit shrinking and swelling, it should have a maximum liquid limit of 45, and its plasticity index should be 20 or less.

Fill should be free of fat clay and organic soil (Unified Soil Classification CH, OL, OH, MH, or PT), frozen material, rubble, degradable material, chemical contaminants, and stones that interfere with compaction or compaction testing. In general, at least 70% of the fill should pass a 3/4-inch sieve, the over-size limit for the ASTM D698 maximum density test.

Fill should be placed on stable, unfrozen surfaces and in nearly horizontal lifts that have thicknesses that are compatible with the compaction equipment used, but generally not over eight inches. All fill should be compacted to at least 98% of its maximum dry density determined by ASTM D698, Test Method for Laboratory Compaction Characteristics of

Soil Using Standard Effort (12,400 ft-lbf/cu.ft.). Compaction usually requires adjustment of fill moisture contents to within two or three percentage points of the ASTM D698 optimum moisture.

4.5 SHALLOW FOUNDATIONS

For the assumed footing loads described in Section 4.1 and once the existing fill has been addressed, we recommend the soils at the base of all excavations be disked, dried, moisture conditioned, and compacted with a walk-behind plate compactor to provide more uniform bearing conditions. Once the above criteria are met, shallow foundation support appears possible.

At conventional footing depths, the project borings encountered existing fill, silty fine-grained sand (alluvium), and sandy clay (alluvium). For footings bearing directly on new

Controlled Fill that completely replaces the existing fill or upon native alluvium, a maximum allowable bearing pressure of 1500 pounds per square foot is recommended for design. This net pressure is the pressure in excess of that generated by the lowest final grade adjacent to the footings. If the pressure permits continuous and isolated footing widths of less than 16 and 30 inches these minimum widths should be provided.

Where soft bearings soils, existing fill soils, or other unsuitable soils are encountered over-excavation and backfill procedures may be necessary. Backfill may be selected from alternatives listed in the following table.

Table D. Over-Excavation Backfill Materials

Backfill Material Requirement

1” Clean Stone (CA7) 70% Relative Density

Flowable Fill (CLSM) 500 psi 28-day Strength

Lean Concrete 1,500 psi 28-day Strength

When backfill is clean one-inch nominal size crushed stone (Illinois Gradation CA-7), it should extend outside of all footing edges by at least 8 inches per foot of backfill thickness beneath the footings. This is illustrated by Figure 1.

During construction, footing bearing surfaces need to be protected from loosening, water-softening or freezing. If soil becomes disturbed, they should be replaced with Table D backfill material.

If groundwater is encountered, it should be removed and bearing soils should be protected by expedient placement of concrete or by a clean stone working mat. Additionally, excavation should not proceed below the groundwater level. Rather, temporary sumps and pumps should be utilized to maintain groundwater a minimum of two feet below excavation base elevations. Probing and testing of foundation soils by a geotechnical engineering company throughout construction is recommended.

Foundations should be protected from frost action by placement beneath soil cover that is at least 42 inches. When using the stated bearing pressure and following the recommendations it is our opinion, settlements due to consolidation of the foundation soil should be about one inch or less. Differential settlements should be on the order of one-half to 2/3 of the estimated total settlement.

4.6 LATERAL EARTH PRESSURES

Any walls that retain soils will be subject to unbalanced earth pressures and should be designed using the pressure distribution provided in Table E. Cohesionless backfill lateral pressures may be used for the free-draining granular backfill. Any other surcharge loads, whether temporary or permanent, should be examined and applied to the walls by the

Structural Engineer.

Figure 1. Over-Excavation Sketch

Table E. Lateral Earth Pressure Design Parameters

Condition Cohesive Soil

(non-expansive clay) Cohesionless Soil

(granular)

Assumed Backfill Characteristics

Approximate Total Density 130 pcf 120 pcf

Approximate Friction Angle 15° to 20° 30° to 35°

Active Pressure Coefficient, Ka 0.5 0.3

At-Rest Pressure Coefficient, Ko 0.7 0.5

Passive Pressure Coefficient, Kp 2.0 3.3

Estimated Lateral Earth Pressure 1 (Equivalent Fluid Pressures)

Active - Drained Active - Undrained 2

65 pcf 95 pcf

35 pcf 80 pcf

At-Rest - Drained At-Rest - Undrained 2

90 pcf 110 pcf

60 pcf 90 pcf

Passive - Drained Passive - Undrained 3

260 pcf 135 pcf

400 pcf 190 pcf

Table Notes:

(1) Assumes no safety factor, negligible wall friction, vertical wall, level backfill, zero surcharge load and ignores soil cohesion.

(2) Combined buoyant backfill unit weight and hydrostatic loading (water = 62.4 pcf).

(3) Excludes hydrostatic loading.

Active earth pressure design assumes that the wall can rotate and deflect at the top. If the wall is either pinned or is rigidly fixed, higher lateral earth pressures will develop against the wall and at-rest pressure parameters should be used for design. Increased earth pressures may also develop from restricted soil drainage, surcharge loads adjacent to the wall, and during compaction of the adjacent backfill. The additional uniformly distributed wall pressure can be estimated by multiplying the equivalent uniform surcharge pressure by the above active or at-rest pressure coefficient.

4.7 SEISMIC SITE CLASSIFICATION

Based on the soil conditions encountered in the project borings, our past exploration experience at nearby projects, and with respect to guidance provided by the International

Building Code, Seismic Site Class “C” should be used for the seismic design of the structure. It should be noted that this area is not considered a high-risk seismic zone, and the general area has experienced minimal seismic events.

A site-specific seismic evaluation, such as Refraction Microtremor (ReMi) survey could be considered to further evaluate the seismic site class. If this option may provide value to the project, please contact us.

5.0 CLOSING REMARKS

5.1 EXCAVATIONS

Excavations may stand with 3- or 4-foot-tall vertical banks for short periods of time, but they should not be considered stable. Banks of deeper excavations are not as reliable and may slump or flow especially where fill, sand, or groundwater are encountered.

Excavations should be sloped, stepped, braced, or shored to provide protection for workers and portions of below grade structures under construction.

As a minimum, trenching and excavating should conform to local, state, and federal requirements including OSHA 29 CFR Part 1926. Draping excavation slopes with geotechnical fabric or poly sheeting can also be an effective measure to control moisture loss of the soils and to minimize erosion resulting from precipitation events.

5.2 CONSTRUCTION INSPECTION

Due to the possibility of variation in subsurface conditions at locations not observed by the current geotechnical study, it is recommended that the Geotechnical Engineer observe all subgrades and excavations to verify suitability of the bearing materials. The

Geotechnical Engineer should confirm that the bearing surfaces are clean, well prepared, and contain no soft, wet, or otherwise deleterious materials.

In the interest of completeness and to provide a comprehensive contact list to elevate report questions and to schedule future construction materials testing services, applicable IMEG contact information is provided by Table F.

Table F. IMEG Contact Information

IMEG Contact Organizational Role Phone Email

Ruth Arnold Proposals & Billing 309.605.0145 Ruth.M.Arnold@imegcorp.com

Melissa Nye Field Testing Services 309.230.3674 Melissa.L.Nye@imegcorp.com

Nate Lawson, EIT Engineering Questions 309.948.1775 Nathaniel.J.Lawson@imegcorp.com

5.3 STUDY LIMITATIONS

The purpose of this study was to provide limited subsurface information for the site. The borings should assist in prediction of conditions present when executing construction activities. The boring may not reflect all variations that occur across the site and careful construction observations will be necessary to identify conditions requiring adjustments in grading, further excavation, or design. Remedial funds should be available to accommodate changes encountered during construction.

This report has been prepared for the exclusive use of our client for the specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No other warranty is expressed or implied.

In the event that any changes in the nature, design or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed, and the conclusions of this report modified in writing by the Geotechnical Engineer.

The borings and report do not assess site environmental conditions or determine presence of pollutants in the soil, rock, and groundwater. Such work is beyond the scope of this study.

mailto:Ruth.M.Arnold@imegcorp.com mailto:Melissa.L.Nye@imegcorp.com mailto:Nathaniel.J.Lawson@imegcorp.com

The following figures and appendices are attached and complete this report.

APPENDIX DESCRIPTION

A Boring Location Diagram B Logs for Borings C Soil Description Charts

Appendix A Boring Location Map

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IMEG Project No.

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Date: 2024.12.18

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HA-3

HA-1

HA-2

TBM 1 (North Manhole) Elevation = 100.00 Top of Porch Elevation = 104.96

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Boring Elevation = 100.42 Existing Fill Depth = 3.0 feet Bottom of Fill Elevation = 97.42

Boring Elevation = 99.92 Existing Fill Depth = 3.0 feet Bottom of Fill Elevation = 96.92

Boring Elevation = 100.37 Existing Fill Depth = 4.0 feet Bottom of Fill Elevation = 96.37

Appendix B

Logs for Borings

DRILLER

DRILL RIG

BORING NO. / LOCATION

DATE 100.4 FT.

REFUSAL 7.8 FT. ELEV. 92.6 FT. SEEPAGE:

SAMPLED 7.8 FT.

TOP OF ROCK 7.7 FT. ELEV. 92.7 FT. COMPLETION:

BEGAN CORING FT. ELEV. FT.

FOOTAGE CORED LF

BOTTOM OF HOLE DEPTH 7.8 FT. ELEV. 92.6 FT.

PENETROMETER TYPE X

SAMPLE

FT. ELEV. TYPE N-Value Qp %M DD UCS Qr

FILL:

Dark Brown Sandy Clay, Moist, Loose

Dark Brown Sandy Clay and Gravel

Moist, Loose

3.0

SILTY FINE-GRAINED SAND (ALLUVIUM):

Dark Brown

Moist

Loose 5.0

SANDY CLAY (ALLUVIUM):

Brown, Very Moist, Loose 6.0

SILTY CLAY (ALLUVIUM):

Red Brown

Moist, Loose 7.7

HIGHLY WEATHERED LIMESTONE: 7.8

DCP N = 13

3.0 4.0 4 DCP N = 5

END OF BORING (HAND AUGER REFUSAL)

DCP N = 25/1"

6.0 7.0 7

10.0 90.4

7.5 92.9 7.7 7.8 8

5.0 95.4

16.6

21.0

15.7

15.0

13.2

17.3

23.7

19.3

REMARKS: Boring Elevations Estimated Using Google Earth

12.5 87.9

NOTE: All Borings were Backfilled with the Available

Auger Cuttings at Completion of the Monitoring Period.

The stratification lines represent the approximate boundary between soil types; however, the actual transition may be more abrupt or gradual.

Qp = spring-calibrated pocket penetrometer reading (tons per square foot)

%M = oven-dried soil moisture content (percent)

DD = oven-dried sample dry unit weight (pounds per cubic foot)

UCS = sample laboratory unconfined compressive strength (tons per square foot)

Qr = sample laboratory remolded strength (tons per square foot)

17.5 82.9

20.0 80.4

15.0 85.4

5.0 6.0 6 DCP N = 9

4.0 5.0 5 DCP N = 7

2.5 97.9 2.0 3.0 3 DCP

1.0 2.0 2 DCP N = 3

N = 6

NONE

NONE

BACKFILLED AT COMPLETION

STRATUM DESCRIPTION

FT. FT. RUN NO.

0.0 1.0 1 DCP N = 8

DEPTH FROM TO OR RESULTS RESULTS

SOWERS FOUNDATION DCP

STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY

DUAL MASS PAVEMENT DCP

New ADA Ramp - Quarters One LOG OF BORING HA-1 1940 Gillespie Circle SHEET 1 OF

2024.12.18 SURFACE ELEV. WATER LEVEL DATA (IF APPLICABLE)

Rock Island Arsenal, Illinois N. LAWSON (IMEG-ROCK ISLAND)

IMEG Project Number: 24007322.00 3.25-INCH DIAMETER HAND AUGER

HA-1 DRY AT COMPLETION YES

DRILL RIG

BORING NO. / LOCATION

DATE 99.9 FT.

REFUSAL 7.6 FT. ELEV. 92.3 FT. SEEPAGE:

SAMPLED 7.6 FT.

TOP OF ROCK 7.5 FT. ELEV. 92.4 FT. COMPLETION:

BEGAN CORING FT. ELEV. FT.

FOOTAGE CORED LF

BOTTOM OF HOLE DEPTH 7.6 FT. ELEV. 92.3 FT.

PENETROMETER TYPE X

SAMPLE

FT. ELEV. TYPE N-Value Qp %M DD UCS Qr

4-INCH HMA SURFACE OVER 6-INCH

AGGREGATE SUBBASE: 0.9

FILL:

Dark Brown Silty Fine-Grained Sand

Moist, Loose

3.0

SANDY CLAY (ALLUVIUM):

Red-Brown

Very Moist

Loose 5.0

LEAN TO SILTY CLAY (ALLUVIUM):

Red-Brown

Very Moist

Loose

7.5

HIGHLY WEATHERED LIMESTONE: 7.6

New ADA Ramp - Quarters One LOG OF BORING HA-2 1940 Gillespie Circle SHEET 1 OF

2024.12.18 SURFACE ELEV. WATER LEVEL DATA (IF APPLICABLE)

NONE

NONE

BACKFILLED AT COMPLETION

Rock Island Arsenal, Illinois N. LAWSON (IMEG-ROCK ISLAND)

IMEG Project Number: 24007322.00 3.25-INCH DIAMETER HAND AUGER

HA-2 DRY AT COMPLETION YES

DEPTH FROM TO OR RESULTS RESULTS

SOWERS FOUNDATION DCP DUAL MASS PAVEMENT DCP

STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY

15.5

1.0 2.0 2 DCP N = 6 12.5

STRATUM DESCRIPTION

FT. FT. RUN NO.

0.0 1.0 1 DCP N = 5

2.5 97.4 2.0 3.0 3 DCP N = 5 11.6

4.0 5.0 5 DCP N = 8 21.3

3.0 4.0 4 DCP N = 9 18.4

6.0 7.0 7 DCP N = 9 18.5

5.0 94.9

5.0 6.0 6 DCP N = 8 21.6

N = 30/1" 9.5

END OF BORING (HAND AUGER REFUSAL)

The stratification lines represent the approximate boundary between soil types; however, the actual transition may be more abrupt or gradual.

NOTE: All Borings were Backfilled with the Available

Auger Cuttings at Completion of the Monitoring Period.

10.0 89.9

Qp = spring-calibrated pocket penetrometer reading (tons per square foot)

7.5 92.4 7.5 7.6 8 DCP

15.0 84.9

%M = oven-dried soil moisture content (percent)

DD = oven-dried sample dry unit weight (pounds per cubic foot)

UCS = sample laboratory unconfined compressive strength (tons per square foot)

12.5 87.4 Qr = sample laboratory remolded strength (tons per square foot)

REMARKS: Boring Elevations Estimated Using Google Earth

17.5 82.4

20.0 79.9

DRILL RIG

BORING NO. / LOCATION

DATE 100.4 FT.

REFUSAL 7.3 FT. ELEV. 93.1 FT. SEEPAGE:

SAMPLED 7.3 FT.

TOP OF ROCK 7.2 FT. ELEV. 93.2 FT. COMPLETION:

BEGAN CORING FT. ELEV. FT.

FOOTAGE CORED LF

BOTTOM OF HOLE DEPTH 7.3 FT. ELEV. 93.1 FT.

PENETROMETER TYPE X

SAMPLE

FT. ELEV. TYPE N-Value Qp %M DD UCS Qr

2.25-INCH HMA SURFACE OVER 6-INCH

AGGREGATE SUBBASE: 0.7

FILL:

Brown Silty Fine-Grained Sand with Red brick

Very Moist

Very Loose

4.0

SILTY FINE-GRAINED SAND (ALLUVIUM):

Brown

Very Moist

Very Loose

7.2

DCP N = 30/1" 9.8 HIGHLY WEATHERED LIMESTONE: 7.3

New ADA Ramp - Quarters One LOG OF BORING HA-3 1940 Gillespie Circle SHEET 1 OF

2024.12.18 SURFACE ELEV. WATER LEVEL DATA (IF APPLICABLE)

NONE

NONE

BACKFILLED AT COMPLETION

Rock Island Arsenal, Illinois N. LAWSON (IMEG-ROCK ISLAND)

IMEG Project Number: 24007322.00 3.25-INCH DIAMETER HAND AUGER

HA-3 DRY AT COMPLETION YES

DEPTH FROM TO OR RESULTS RESULTS

SOWERS FOUNDATION DCP DUAL MASS PAVEMENT DCP

STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY

13.4

1.0 2.0 2 DCP N = 2 12.0

STRATUM DESCRIPTION

FT. FT. RUN NO.

0.0 1.0 1 DCP N = 17

2.5 97.9 2.0 3.0 3 DCP N = 2 18.8

4.0 5.0 5 DCP N = 1 19.7

3.0 4.0 4 DCP N = 1 19.1

N = 5 18.3

5.0 95.4

5.0 6.0 6 DCP N = 2 19.3

87.3

7.5 92.9

7.0

6.0 7.0 7 DCP

DD = oven-dried sample dry unit weight (pounds per cubic foot)

UCS = sample laboratory unconfined compressive strength (tons per square foot)

12.5 87.9 Qr = sample laboratory remolded strength (tons per square foot)

The stratification lines represent the approximate boundary between soil types; however, the actual transition may be more abrupt or gradual.

10.0 90.4

Qp = spring-calibrated pocket penetrometer reading (tons per square foot)

END OF BORING (HADN AUGER REFUSAL)

NOTE: All Borings were Backfilled with the Available

Auger Cuttings at Completion of the Monitoring Period.

REMARKS: Boring Elevations Estimated Using Google Earth

17.5 82.9

20.0 80.4

15.0 85.4

%M = oven-dried soil moisture content (percent)

Appendix C Soil Description Charts

Quarters One 1940 Gillespie Circle

Rock Island Arsenal, Illinois

January 10, 2025

C-1

Soils Descriptions

Soils descriptions are based on the Unified Soil Classification System and ASTM D2488 (visual-manual procedure) unless otherwise indicated. Coarse-grained soils (sands and larger) have more than 50% of dry weight retained on a #200 sieve. They are described as boulders, cobbles, gravel or sand. Fine-grained soils have less than 50% of their dry weight retained on a #200 sieve. They are described as clays or silts depending on their liquid and plastic limits. There can be some sand content in the clays and can be some silt or clay content in the sands. Adjectives are used to further describe these materials.

For example:

Lean clay with sand is a clay of low plasticity, thus lean, having 15% to 29% sand grains mixed into it. Sandy lean clay is a clay of low plasticity having 30% to 50% sand grains mixed into it.

Relative Properties of Sand or Gravel in

Clay Relative Amount of Fines Passing

#200 Sieve in Sand or Gravel Descriptive Term Percent of Dry

Weight Descriptive Term Percent of Dry

Weight Trace Sand* Less than 15 Trace Clay* Less than 5 With Sand* 15 to 30 With Clay 5 to 12

Sandy 30 to 50 Clayey 12 to 50 *or Gravel, Gravelly *or Silt, Silty

Grain-Size Terminology Description of Fine-Grained Soils

Descriptive Term

Diameter (inches)

For Liquid Limits Less Than 50 PI > 7 Lean Clay

Boulders > 12 4 < PI < 7 Silty Clay Cobbles 3 to 12 PI < 4* Silt Gravel #4 Sieve to 3 For Liquid Limits of 50 and Higher Sand #200 to #4 Sieve Plots on or Above A-

Line Fat Clay

Silt or Clay < #200 Sieve Plots Below A-Line Elastic Silt *or below A-Line

Definitions

Liquid Limit (LL) Moisture content where soil changes from plastic to liquid state as determined by ASTM D4318

Plastic Limit (PL) Moisture content where soil changes from plastic to semi-solid state as determined by ASTM D4318

Plasticity Index (PI) Numerical difference between liquid limit and plastic limit (PI = LL - PL)

C-2

Consistency of Cohesive (Clayey) Soils Description UCS (psf) Nblows/foot CBR* Appearance

Very Soft 0 to 500 0 to 2 0.0 to 0.4 Extruded through fingers when squeezed

Soft 500 to 1000 2 to 4 0.4 to 0.8 Molded by very light finger pressure

Medium 1000 to 2000 4 to 8 0.8 to 1.6 Molded by light finger pressure

Stiff 2000 to 4000 8 to 15 1.6 to 3.2 Readily indented by thumb

Very Stiff 4000 to 8000 15 to 30 3.2 to 6.4 Readily indented by thumbnail

Hard 8000+ 30+ 6.4+ Hard to indent by thumbnail

*California Bearing Ratio (CBR) = subgrade support value for paving expressed as a percent of value for standard crushed stone

Relative Density of Cohesionless (Sand) Soils

Grain-Size Terminology

Description Nblows/foot

Friction Angle

(degrees)

Descriptive Term

Diameter (inches)

Very Loose 0 to 4 26 to 30 Boulders > 12

Loose 4 to 10 28 to 34 Cobbles 3 to 12

Medium 10 to 30 30 to 40 Gravel #4 Sieve to 3

Dense 30 to 50 33 to 45 Sand #200 to #4 Sieve

Very Dense 50+ 50+ Silt or Clay < #200 Sieve

Note: Lower limits are for fine, clean sand and should be reduced by up to 5 degrees for silty sands. The upper limits are for coarse clean sands.

C-3

Comments on Soil Color Descriptions

Dark Gray, Blue, or Green Constant submergence with a total absence of available oxygen

Gray with Concretions Saturation with water of limited oxygen supply

Red-Brown, Yellow-Brown, and Olive-Brown

Abundant supply of oxygen under good condition of drainage

Red-Brown, Yellow-Brown, and Olive-Brown with Gray Mottles

Abundant supply of oxygen under poor drainage conditions (occasional to frequent saturation)

C-4

Sedimentary Rocks

These rocks are comprised of sediments that were laid down mostly by water but wind and glacial action was also sometimes involved. The sediments consisted of particles of previous rocks and/or of minerals having a chemical or organic origin. The sediments were usually hardened by cementation or compaction over geologic time; however, the existing degree of hardening may vary widely due to differences in deposition processes and subsequent weathering. Weak planes (i.e., seams, fractures, fissures) or other discontinuities could be present in these rocks.

Gravel, sand, silt and clay sized particles make up the sediments in these rocks. All types of rocks and minerals could be represented in these sediments; however, gravel and sand are usually rock fragments; fine sand and silt particles are usually mineral grains;

and clay particles are mineral grains mostly from the clay mineral group.

The accurate identification of rocks and minerals can, in many cases, only be made by a geologist, mineralogist or petrographer using testing equipment and procedures associated with these sciences. However, the following presents a basis for providing general descriptions. Most rocks grade from the descriptions given, and intermediate descriptions can be found.

Shales – these are very fine-grained rocks composed of silts and clays deposited in quiet waters.

Sandstones and Conglomerates – these are composed of particles of sand, gravel or both with or without interstitial cementing material.

Carbonate Rocks – limestones are the predominant carbonate rock. They can range from pure limestone consisting of the calcite mineral to pure dolomite consisting of the dolomite mineral. Usually, they contain both limestone and dolomite in various proportions. Limestone reacts with hydrochloric acid readily. Dolomite may need to be ground to a powder to show a reaction.

Chert – chert is a very fine-grained texture and breaks into angular fragments. It is composed of microcrystalline or cryptocrystalline quartz, chalcedony or opal.

C-5

UNIFIED SOIL CLASSIFICATION SYSTEM

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

Soil Classification

Group Symbol

Group Name B

Coarse-Grained Soils Gravels Clean Gravels Cu ≥ 4 and Cc ≤ 3 E GW

Well-graded gravel F

More than 50% retained on No.

200 sieve

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

Less than 5% finesC Cu < 4 and/or 1 > Cc > 3 E GP

Poorly graded gravel F

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

More than 12% finesC Fines classify as CL or MH GC Clayey gravel F, G, H

Sands Clean Sands Cu ≤ 4 and 1 ≤ Cc ≤ 3 E SW Well-graded sand I

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

Less than 5% finesD Cu < 6 and/or 1 > Cc > 3 E SP

Poorly graded sand I

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

More than 12% finesD Fines classify as CL or CH SC Clayey sand G, H, I

Fine-Grained Soils Silts and Clays inorganic PI > 7 and plots on or above "A" line J CL Lean clay K, L, M

50% or more passes the No.

200 sieve

Liquid limits less than 50 PI < 4 and plots below "A" line J ML Silt K, L, M organic Liquid limit - oven dried

< 0.75 OL

Organic clay K, L, M, N

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

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

Liquid limit 50 or PI plots below "A" line J MH Elastic silt K, L, M more organic Liquid limit - oven dried

< 0.75 OH

Organic clay K, L, M, P

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

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

C-6

Table Notes:

A Based on the material passing the 3-in. (75 mm) sieve. H If fines are organic, add "with organic fines" to group name.

B If field sample contained cobbles or boulders, or both, add "with I If soil contains ≥ 15% gravel, add "with gravel" to group name.

cobbles" or "boulders", or "both" to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.

C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded K If soil contains 15 to 29% plus No. 200, add "with sand" or "with gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly gravel", whichever is predominant.

graded gravel with silt, GP-GC poorly graded gravel with clay. L If soil contains ≥ 30% plus No. 200 predominantly sand, add "sandy" D Sands with 5 to 12 % fines require dual symbols: SW-SM well-graded to group name.

sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded M If soil contains ≥ 30% plus No. 200 predominantly gravel, add sand with silt, SP-SC poorly graded sand with clay. "gravelly" to group name.

E Cu = D60 / D10 CC = (D30)2 N PI ≥ 4 and plots on or above "A" line.

D10 x D60 O PI < 4 or plots below "A" line.

F If soil contains ≥ 15% sand, add "with sand" to group name. P PI plots on or above "A" line.

G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM. Q PI plots below "A" line.