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Geotechnical Engineering and Materials Testing
GEOTECHNICAL ENGINEERING REPORT
Pedersen Toyota Dealership Expansion
4455 South College Avenue
Fort Collins, Colorado
Prepared For:
Pedersen Toyota
4455 South College Avenue
Fort Collins, CO 80525
Prepared By:
Cole Garner Geotechnical
CGG Project No.: 25.22.116
August 25, 2025
Geotechnical Engineering and Materials Testing
Cole Garner Geotechnical
1070 W. 124th Ave, Ste. 300
Westminster, CO 80234
303.996.2999
August 25, 2025
Pedersen Toyota
4455 South College Avenue
Fort Collins, CO 80525
Attn: Anne Breck, TallyCM
Re: Geotechnical Engineering Report
Pedersen Toyota Dealership Expansion
4455 South College Avenue
Fort Collins, Colorado
CGG Project No. 25.22.116
Cole Garner Geotechnical (CGG) has completed a geotechnical engineering investigation for the proposed
expansion of the subject automotive dealership located in Fort Collins, Colorado. This geotechnical
summary should be used in conjunction with the entire report for design and/or construction purposes.
It should be recognized that specific details were not included or fully developed in this section, and the report
must be read in its entirety for a comprehensive understanding of the items contained herein. The section
titled General Comments should be read for an understanding of the report limitations.
• Subsurface Conditions: Approximately 7 to 9 feet of apparent man-made fill was encountered in our
borings across the site. The fill was variable but was primarily comprised of clayey sand and sandy
lean clay. We assume that the fill is related to original development of the property and existing
improvements. Native soils encountered below the fill were similar and consisted of varying layers of
clayey to silty sands and lean clays that extended to the full depth of exploration in some borings.
Sedimentary sandstone and claystone bedrock was encountered at depths ranging from about 17 to
23 feet below existing site grade in three of the four deeper borings and extended to the full depth of
exploration. Groundwater was encountered at depths ranging from about 18 to 20 feet below existing
site grade in the proposed building expansion area and at a depth of about 14 feet below existing site
grade in Boring No. 6. Other specific information regarding the subsurface conditions is shown on the
attached Boring Logs.
• Existing Fills: The man-made fill materials encountered in our borings appear to be relatively firm but
did contain varying amounts of asphalt debris fragments. The client must understand that
undocumented fills present an inherent risk that the fill contains or conceals areas or layers of poorly
compacted soils or unsuitable materials (such as organics or construction debris). Unsuitable soils or
excessive debris was not encountered in our borings; therefore, we believe there is low risk of
encountering large areas of unsuitable materials. At a minimum, we believe at least portions of the
fill should be removed and recompacted below new building foundations as discussed in the report.
It may be feasible to leave the fill soils in place below new floor slabs; however, further evaluation
is recommended.
Geotechnical Engineering Report
Pedersen Toyota Dealership Expansion – Fort Collins, CO
CGG Project No. 25.22.116
Cole Garner Geotechnical Page ii
Geotechnical Engineering and Materials Testing
• Expansive Soils: The clayey fill soils at or near foundation bearing elevations are defined as Expansive
Soils but exhibited low-expansive potential. Post-construction wetting of these highly expansive
materials can result in excessive or uneven movement of shallow foundations, floor slabs, exterior
flatwork, pavements, et cetera. We have provided recommendations to reduce the risk of movement
and distress; however, eliminating the risk of movement and cosmetic distress is generally not
considered feasible. It may be possible to further reduce the risk of movement if significantly more
expensive measures are used during construction.
• Structural Considerations: It is our opinion that the undocumented fill soils pose a moderate to high
risk of movement of spread footings foundations. To mitigate this risk, we recommend that site
preparation include overexcavation and recompaction of the fill soils below new foundations; provided
site grades will remain relatively unchanged, we believe this zone will extend about 4 to 5 feet below
new foundation bearing elevation. The base of this zone should also extend at least 3 feet laterally
beyond foundation edges. Recompacted on-site soils (provided they are substantially free of debris) may
be used to raise the site back up to footing bearing elevation.
We believe that the fill materials can likely remain in place for support of interior floor slabs, however,
we recommend further evaluation of the fill materials in each building footprint to confirm the fill is
suitable. This can be conducted vie test pits excavated during footing subgrade preparation. Additional
details are presented in the report.
We appreciate being of service to you in the geotechnical engineering phase of this project and are
prepared to assist you during the construction phases as well. Please do not hesitate to contact us if you
have any questions concerning this report or any of our testing, inspection, design and consulting services.
Sincerely,
Cole Garner Geotechnical
Andrew J. Garner, P.E.
Principal, COO
8/25/25
Geotechnical Engineering Report
Pedersen Toyota Dealership Expansion – Fort Collins, CO
CGG Project No. 25.22.116
Cole Garner Geotechnical Page iii
Geotechnical Engineering and Materials Testing
TABLE OF CONTENTS
Page No.
Letter of Transmittal .............................................................................................................................. ii
INTRODUCTION ..................................................................................................................................... 1
PROJECT INFORMATION ....................................................................................................................... 1
SITE EXPLORATION PROCEDURES ........................................................................................................ 2
Field Exploration ............................................................................................................................. 2
Laboratory Testing .......................................................................................................................... 3
SITE CONDITIONS .................................................................................................................................. 3
SUBSURFACE CONDITIONS ................................................................................................................... 3
Geology ........................................................................................................................................... 3
Soil and Bedrock Conditions ........................................................................................................... 4
Field and Laboratory Test Results ................................................................................................... 4
Groundwater Conditions ................................................................................................................ 4
ENGINEERING RECOMMENDATIONS ................................................................................................... 5
Geotechnical Considerations .......................................................................................................... 5
Earthwork ....................................................................................................................................... 6
General Considerations ............................................................................................................ 6
Site Preparation ........................................................................................................................ 6
Mitigation of Existing Fill .......................................................................................................... 6
Subgrade Preparation .............................................................................................................. 7
Fill Materials ............................................................................................................................. 7
Fill Placement and Compaction ................................................................................................ 8
Excavation and Trench Construction ........................................................................................ 8
Foundation Recommendations ....................................................................................................... 9
Lateral Earth Pressures ................................................................................................................. 10
Seismic Considerations ................................................................................................................. 11
Interior Slab-on-Grade Floors ....................................................................................................... 11
Below-Grade Construction ........................................................................................................... 13
Private Pavement Thickness Design and Construction ................................................................. 13
Final Grading, Landscaping, and Surface Drainage ....................................................................... 17
Additional Design and Construction Considerations .................................................................... 18
Exterior Slab Design and Construction ................................................................................... 18
Underground Utility Systems ................................................................................................. 19
Concrete Corrosion Protection ............................................................................................... 19
GENERAL COMMENTS ........................................................................................................................ 20
APPENDIX A: BORING LOCATION DIAGRAM, BORING LOGS
APPENDIX B: LABORATORY TEST RESULTS
APPENDIX C: GENERAL NOTES
Geotechnical Engineering and Materials Testing
Cole Garner Geotechnical
1070 W. 124th Ave, Ste. 300
Westminster, CO 80234
303.996.2999
GEOTECHNICAL ENGINEERING REPORT
PEDERSEN TOYOTA DEALERSHIP EXPANSION
4455 SOUTH COLLEGE AVENUE
FORT COLLINS, COLORADO
CGG Project No. 25.22.116
August 25, 2025
INTRODUCTION
This report contains the results of our geotechnical engineering exploration for the proposed expansion
of the subject automotive dealership in Fort Collins, Colorado. This study was performed in general
accordance with our proposal number P25.22.126 executed July 14, 2025.
The purpose of these services is to provide information and geotechnical engineering recommendations
relative to:
• Geologic conditions
• Subsurface soil and bedrock conditions
• Groundwater conditions
• Foundation design and construction
• Lateral earth pressures
• Floor slab design and construction
• Below-grade construction
• Retaining wall design and construction
• Pavement thickness design and construction
• Earthwork
• Drainage
The recommendations contained in this report are based upon the results of field and laboratory testing,
engineering analyses, our experience with similar subsurface conditions and structures, and our
understanding of the proposed project. In addition, we have reviewed a February 13, 2014 Subsurface
Exploration Report prepared by Earth Engineering Consultants, LLC (EEC) that included borings on the site.
PROJECT INFORMATION
The project will include an expansion of the existing Pedersen Toyota dealership in Fort Collins Colorado.
The expansion will include expanding the footprint of the dealership building with additions to both the
east and west sides of the building. The eastern addition to the front of the building will encompass
approximately 20,500 square feet, while the addition on the west side (back) of the building will be about
Geotechnical Engineering Report
Pedersen Toyota Dealership Expansion – Fort Collins, CO
CGG Project No. 25.22.116
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11,400 square feet in size. We assume that the building additions will include one to two stories of load-
bearing CMU and/or steel-framed superstructure supported on reinforced concrete foundations. We
assume concrete slab-on-grade construction is planned for interior floors. Wall and column loads are
anticipated to be on the order of about 2 to 5 kips per lineal foot and 50 to 250 kips, respectively; however,
we should be provided with this information once available.
Site work to support the expansion will include installation of new underground utilities, installation of
underground stormwater facilities within the northern parking lot, construction of a new tire/trash
enclosure, and reconstruction of private site pavements and fire lanes, new concrete flatwork, and limited
landscaping. The current site plan does not indicate the project will require any public right-of-way
improvements. If our understanding of the project, or assumptions above, is not accurate, or if you have
additional useful information, please inform us as soon as possible so that we may update this proposal
as applicable.
SITE EXPLORATION PROCEDURES
The scope of the services performed for this project included site reconnaissance by the project engineer,
a subsurface exploration program, laboratory testing and engineering analysis.
Field Exploration: Based on the proposed construction and in accordance with your request, we
investigated the subsurface conditions at the site with a total of eleven test borings as shown on the
attached Boring Location Diagram and summarized below:
Boring Designations Purpose Planned Boring Depths
1 through 4 Building addition foundation design 25 to 35 feet
5 through 7
Trash Enclosure foundation design, private
pavement thickness design, and underground
stormwater system information
15 feet
8 through 11 Private pavement design 5 feet
A lithologic log of each boring was recorded by our field personnel during the drilling operations. At
selected intervals, samples of the subsurface materials were obtained by driving modified California barrel
samplers. Penetration resistance measurements were obtained by driving the sample barrel into the
subsurface materials with a 140-pound automatic hammer falling 30 inches. The penetration resistance
value is a useful index to the consistency, relative density or hardness of the materials encountered.
Groundwater measurements were made in each boring at the time of site exploration and the borings
were backfilled with the drilling spoils following these measurements. Surface conditions were restored
by sweeping any remaining loose spoils and patching the pavement surface.
Geotechnical Engineering Report
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CGG Project No. 25.22.116
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Geotechnical Engineering and Materials Testing
Laboratory Testing: Samples retrieved during the field exploration were returned to the laboratory for
observation by the project geotechnical engineer and were classified in general accordance with the
Unified Soil Classification System described in Appendix C. Bedrock was identified using the Rock
Classification notes in Appendix C. At that time, an applicable laboratory-testing program was formulated
to determine engineering properties of the subsurface materials. Following the completion of the
laboratory testing, the field descriptions were confirmed or modified as necessary, and Boring Logs were
prepared. These logs are presented in Appendix A.
Laboratory test results are presented in Appendix B. These results were used for the geotechnical
engineering analyses and the development of foundation and earthwork recommendations. Laboratory
tests were performed in general accordance with the applicable local or other accepted standards.
Selected soil and bedrock samples were tested for the following engineering properties:
• Water content
• Dry density
• Swell/Consolidation
• Grain size
• Plasticity Index
• Water-soluble sulfates
SITE CONDITIONS
The project site is an active automotive dealership; the main showroom and service building is located in
the eastern half of the site. The remainder of the site is paved in asphalt and concrete with limited
landscape improvements. The western half of the site appears to have been used as a self-storage facility;
however, storage buildings were removed between summer 2014 and autumn 2016. The site is bound by
South College Avenue to the east, Kensington Drive to the south, South Mason Street to the west, and an
existing retail development to the north. Overall, the site appears to slope downward to the east with an
estimated 10 feet or less of relief. At each of our boring locations, we measured the thickness of the
asphalt and concrete pavements to range from about 6 to 10 inches.
SUBSURFACE CONDITIONS
Geology: Surficial geologic conditions on the site, as mapped by the U.S. Geological Survey (USGS)
(1Workman, et al, 2018), are variable but mainly include Slocum Alluvium of Pleistocene Age. These
formations are reported to reddish-brown clays, silts, sands, and gravel and are generally less than 10 feet
thick. Bedrock underlying the surface units consists of the Pierre Shale formations of Upper Cretaceous
Age. The formation includes various shale and sandstone members within this area.
1 Workman, J.B., Cole, J.C., Shroba, R.R., Kellogg, K.S., and Premo, W.R., 2018, Geologic map of the Fort Collins 30'×60' quadrangle,
Larimer and Jackson Counties, Colorado, and Albany and Laramie Counties, Wyoming, United States Geological Survey, Scientific
Investigations Map SIM-3399.
Geotechnical Engineering Report
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CGG Project No. 25.22.116
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Mapping completed by the Colorado Geological Survey (2Hart, 1972) indicates the site is located in an area
of "Moderate Swell Potential” associated with East Plum Creek; however, the overall area is mapped as
having “Moderate Swell Potential” and the fill placed at the site is considered low to highly expansive.
Expansive Soils generally includes the on-site clays and the underlying bedrock formation.
No other geologic hazards were identified. Seismic activity in the region is anticipated to be low. With
proper site grading around proposed structures, erosional problems at the site should be reduced.
Soil and Bedrock Conditions: Approximately 7 to 9 feet of apparent man-made fill was encountered in
our borings across the site. The fill was variable but was primarily comprised of clayey sand and sandy
lean clay. We assume that the fill is related to original development of the property and existing
improvements. Native soils encountered below the fill were similar and consisted of varying layers of
clayey to silty sands and lean clays that extended to the full depth of exploration in some borings.
Sedimentary sandstone and claystone bedrock was encountered at depths ranging from about 17 to 23
feet below existing site grade in three of the four deeper borings and extended to the full depth of
exploration. Other specific information regarding the subsurface conditions is shown on the attached
Boring Logs.
Field and Laboratory Test Results: Field test results indicate that the clayey fill soils are typically medium
stiff to very stiff in consistency, while the sandier fill soils are generally loose to medium dense in relative
density. Some very loose sand fill soils were also encountered. Native clay soils are predominantly medium
stiff to stiff; some deeper clay lenses (below groundwater) are soft. The native sand soils are generally
medium dense in relative density, though some loose lenses were encountered below groundwater.
The fill and native soils encountered in our borings exhibited low to moderate plasticity and non- to low
expansive potential Testing of select samples for the presence of water-soluble sulfates indicated
concentrations of nil parts per million (ppm).
Groundwater Conditions: Groundwater was encountered at depths ranging from about 18 to 20 feet
below existing site grade in the proposed building expansion area and at a depth of about 14 feet below
existing site grade in Boring No. 6.
Based upon review of U.S. Geological Survey Maps (3Hillier, et al, 1983), the site is located in an area where
groundwater predominates in unconsolidated alluvial deposits at depths ranging from about 10 to 20 feet
below existing ground surface.
2 Hart, Stephen S., 1972, Potentially Swelling Soil and Rock in the Boulder-Fort Collins-Greeley Area, Colorado, Colorado Geological
Survey, Sheet 1 of 4.
3 Hillier, Donald E.; Schneider, Paul A., Jr., 1979, Depth to Water Table (1976-1977) in the Boulder-Fort Collins-Greeley Area, Front Range
Urban Corridor, Colorado, United States Geological Survey, Miscellaneous Investigations Series Map I-855-I.
Geotechnical Engineering Report
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Zones of perched and/or trapped groundwater may also occur at times in the subsurface soils overlying
bedrock, on top of the bedrock surface or within permeable fractures in the bedrock materials. The
location and amount of perched water is dependent upon several factors including hydrologic
conditions, type of site development, irrigation demands on or adjacent to the site, fluctuations in water
features, seasonal and weather conditions.
ENGINEERING RECOMMENDATIONS
Geotechnical Considerations: The site appears suitable for the proposed construction as long as the
recommendations included herein are incorporated into the design and construction aspects of the
project. In our opinion, the primary geotechnical concerns with respect to the proposed development
include the presence of existing fill soils and expansive bedrock at the site.
• Existing Fills: The man-made fill materials encountered in our borings appear to be relatively firm but
did contain varying amounts of asphalt debris fragments. The client must understand that
undocumented fills present an inherent risk that the fill contains or conceals areas or layers of poorly
compacted soils or unsuitable materials (such as organics or construction debris). Unsuitable soils or
excessive debris was not encountered in our borings; therefore, we believe there is low risk of
encountering large areas of unsuitable materials. At a minimum, we believe at least portions of the
fill should be removed and recompacted below new building foundations as discussed in the report.
It may be feasible to leave the fill soils in place below new floor slabs; however, further evaluation
is recommended.
• Expansive Soils: The clayey fill soils at or near foundation bearing elevations are defined as Expansive
Soils but exhibited low-expansive potential. Post-construction wetting of these highly expansive
materials can result in excessive or uneven movement of shallow foundations, floor slabs, exterior
flatwork, pavements, et cetera. We have provided recommendations to reduce the risk of movement
and distress; however, eliminating the risk of movement and cosmetic distress is generally not
considered feasible. It may be possible to further reduce the risk of movement if significantly more
expensive measures are used during construction.
• Structural Considerations: It is our opinion that the undocumented fill soils pose a moderate to high
risk of movement of spread footings foundations. To mitigate this risk, we recommend that site
preparation include overexcavation and recompaction of the fill soils below new foundations; provided
site grades will remain relatively unchanged, we believe this zone will extend about 4 to 5 feet below
new foundation bearing elevation. The base of this zone should also extend at least 3 feet laterally
beyond foundation edges. Recompacted on-site soils (provided they are substantially free of debris) may
be used to raise the site back up to footing bearing elevation.
We believe that the fill materials can likely remain in place for support of interior floor slabs, however,
we recommend further evaluation of the fill materials in each building footprint to confirm the fill is
Geotechnical Engineering Report
Pedersen Toyota Dealership Expansion – Fort Collins, CO
CGG Project No. 25.22.116
Cole Garner Geotechnical Page 6
Geotechnical Engineering and Materials Testing
suitable. This can be conducted vie test pits excavated during footing subgrade preparation. Additional
details are presented in the report.
Design and construction recommendations for the foundation system and other earth-connected phases
of the project are outlined below.
Earthwork:
• General Considerations: The following presents recommendations for site preparation, excavation,
subgrade preparation and placement of engineered fills on the project.
All earthwork on the project should be observed and evaluated by CGG. The evaluation of earthwork
should include observation and testing of engineered fills, subgrade preparation, foundation bearing
soils and other geotechnical conditions exposed during construction of the project.
• Site Preparation: Strip and remove existing pavements, flatwork, vegetation and other deleterious
materials from proposed building and pavement areas. All exposed surfaces should be free of mounds
and depressions that could prevent uniform compaction. Stripped materials consisting of vegetation
and organic materials should be wasted from the site or used to revegetate landscaped areas or
exposed slopes after completion of grading operations.
The on-site soils were relatively firm at the time of our exploration, however, in our experience, the
subgrade soils directly beneath site pavements and flatwork could be very moist and unstable.
Stability could also be affected by precipitation, repetitive construction traffic, or other factors. Where
unstable conditions, if any, are encountered or develop during construction, workability may be
improved by scarifying and aeration during warmer periods. In some areas, removal and
recompaction (or replacement with other on-site soils) may be suitable to build a stable base for
placement of new fills. If more unstable conditions are encountered or develop during construction,
stabilization can generally be economically performed by placing and compacting or “crowding” larger-
sized crushed aggregate (recycled concrete and asphalt, 3 to 6 inches in diameter) into the high
moisture content, weak soils until a stable base is achieved. The geotechnical engineer should be
contacted to provide for further guidance where unstable conditions are encountered.
• Mitigation of Existing Fill: The field and laboratory data from our boring locations and sampling
intervals suggest that the existing fill is relatively compact, but contains minor asphalt debris. In our
opinion, there is inherent uncertainty associated with man-made fill, therefore, we recommend
removal and recompaction of fill soils below all new building foundations. It should be feasible to
leave the fill in place below floor slabs, site pavements, etc. provided that additional evaluation is
performed during construction.
Geotechnical Engineering Report
Pedersen Toyota Dealership Expansion – Fort Collins, CO
CGG Project No. 25.22.116
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Geotechnical Engineering and Materials Testing
To mitigate the risk associated with the fill and allow for the use of conventional shallow foundations,
we recommend that the full depth of the fill soils below building foundation elements be
overexcavated and recompacted. Provided site grades are not modified as part of the project, we
estimate this process will need to extend to a depth of 4 to 5 feet below foundation bearing elevation
at most locations; however, we recommend this process extend at least 3 feet below all new building
foundations. In addition, we recommend the base of the overexcavation extend at least 3 feet laterally
beyond all foundation edges. This recommendation applies to building footing foundation elements
only; we believe that the fill is generally suitable for support of lightly-loaded floor slabs and other
infrastructure.
Clean, on-site fill soils are suitable for re-use as fill below foundations provided they are processed,
moisture conditioned and properly compacted. In our opinion, this process will limit foundation
movement to levels that are normal for this region.
We believe that the fill poses relatively low risk of excessive movement of other exterior and ancillary
structures, where more movement can typically be tolerated (trash enclosures, retaining walls, etc.).
At a minimum, we recommend further evaluation of the fill (with test pit observations, proof rolls,
etc.) prior to construction of these elements to confirm the fill may remain in place. Where unsuitable
materials (soft/loose, expansive) are present, deeper removal, screening, and recompaction may be
required. We recommend the project budget and schedule include contingencies to account for
some limited mitigation across the site.
• Subgrade Preparation: All subgrade soils prior to placement new fill, at the base of overexcavations,
below slab-on-grade floors, exterior PCC flatwork, and pavements should be scarified to a minimum
depth of 12 inches, moisture conditioned and compacted as discussed below just prior to construction
of these elements.
• Fill Materials: Clean on-site soils or approved imported materials may be used as fill material. Other
imported soils used for general fill (if required) should conform to the following:
Percent finer by weight
Gradation (ASTM C136)
6” ................................................................................................................................... 100
3" ............................................................................................................................... 70-100
No. 4 Sieve ................................................................................................................ 50-100
No. 200 Sieve ............................................................................................................ 65 max
• Liquid Limit ........................................................................................................ 35 (max)
• Plasticity Index .................................................................................................. 20 (max)
• Maximum expansive potential (%)* .......................................................................... 0.5
*Measured on a sample compacted to approximately 95 percent of the ASTM D698 maximum dry
density at about optimum water content. The sample is confined under a 500 psf surcharge and
submerged.
Geotechnical Engineering Report
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• Fill Placement and Compaction: The on-site soils are suitable for use as fill on the site. These materials
should be processed with a maximum particle size of about 3 to 4 inches. Engineered fill for site
development, grading, and below foundations and floor slabs should be placed and compacted in
horizontal lifts, using equipment and procedures that will produce recommended moisture contents
and densities throughout the lift. Fill soils should be placed and compacted according to the following
criteria:
Criteria Recommendations
Fill soil types On-site materials or imported soils
Maximum Particle Size 3 to 4 inches
Lift Thickness 8 to 12 inches or less in loose thickness
Moisture Content Range
• Clayey soils: +1% to +4% above optimum moisture content
• Non-plastic granular soils: -2% below to +3% above optimum
• Pavement areas: Optimum to +2% above optimum
Compaction
Clayey soils: ASTM D698 standard Proctor dry density
• 95% minimum
Non-plastic granular soils: ASTM D1557 modified Proctor dry density
• 95% minimum
Earthwork contractors should use equipment and methods that ensure the soils are properly
processed with a relatively uniform distribution of added moisture and adequate compaction
throughout each lift. We recommend that fill placement and compaction beneath foundations, floor
slabs, deep underground utilities, and retaining wall backfill be observed and tested by CGG on a
full-time basis, unless modified by the geotechnical engineer.
At a minimum, fill soils placed for site grading, utility trench backfill, foundation backfill or sub-
excavation fill, and floor slab and PCC flatwork subgrade soils should be tested to confirm that
earthwork is being performed according to our recommendations and project specifications.
Subsequent lifts of fill should not be placed on previous lifts if the moisture content or dry density is
determined to be less than specified.
Fill should not be allowed to dry significantly prior to construction. Areas allowed to dry may require
additional preparation prior to construction of roadways, flatwork, foundations, et cetera.
• Excavation and Trench Construction: It is anticipated that excavations for the proposed construction
can be accomplished with conventional, heavy-duty earthmoving equipment that is common in the
region. Excavations into the clayey fill will likely stand on relatively steep temporary slopes; however,
caving sands are also present at the site. The individual contractor(s) should be made responsible
for designing and constructing stable, temporary excavations as needed to maintain stability of both
the excavation sides and bottom. All excavations should be sloped or shored in the interest of safety
following local and federal regulations, including current OSHA excavation and trench safety
standards.
Geotechnical Engineering Report
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Contractors should use additional care to not undermine the foundation of the existing structure.
Shoring or underpinning of existing foundations could be required as excavations approach the
existing building or other elements..
The soils to be penetrated by the proposed excavations may vary significantly across the site. The
contractor should verify that similar conditions exist throughout the proposed area of excavation. If
different subsurface conditions are encountered at the time of construction, the actual conditions
should be evaluated to determine any excavation modifications necessary to maintain safe
conditions.
As a safety measure, it is recommended that all vehicles and soil piles be kept to a minimum lateral
distance from the crest of the slope equal to no less than the slope height. The exposed slope face
should be protected against the elements.
Foundation Recommendations: The subsurface conditions include historic, undocumented fill. It is our
opinion that these conditions pose a moderate risk of movement of spread footing foundations. Mitigation
will be required below foundation bearing elements as described above. Provided these soils conditions are
mitigated as described above, the following shallow foundation design criteria may be used for the
structural design of foundations:
Criteria Design Value
Bearing Strata1
Recompacted on-site fill soils, unless
otherwise required by the
Geotechnical Engineer
Maximum net allowable bearing pressure2 2,500 psf
Min. depth below grade, exterior wall footings3 36 inches
Min. depth below grade, interior footings3 12 inches
Estimated maximum total foundation movement4 1 inch
Estimated maximum differential foundation movement4 ½ to ¾ of total
1. This will require the removal and recompaction of the full-depth of existing fill soils; We estimate this zone
will need to extend to at least 4 to 5 feet below building foundations and laterally 3 feet beyond footing
edges.
2. The design bearing pressure above applies to dead loads plus design live load conditions. The design bearing
pressure may also be increased by 1/3 when considering total loads that include wind or seismic conditions.
3. Finished grade is the lowest adjacent grade for perimeter footings and floor level for interior footings.
4. Based on assumed structural loads. Footings should be proportioned to apply relative constant dead load
pressure in order to reduce differential movement between adjacent footings.
The movement estimates above are contingent upon providing and maintaining good surface drainage
away from structures for the life of the project. Excessive foundation movements could occur if water
from any source infiltrates the foundation soils; therefore, proper drainage should be provided in the final
Geotechnical Engineering Report
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design and during construction. Failure to maintain proper surface drainage could result in soil-related
foundation movement exceeding the above estimation.
Foundation excavations and subexcavation and earthwork operations should be observed by the
geotechnical engineer during construction. If the soil conditions encountered differ significantly from
those presented in this report, supplemental recommendations may be required.
Lateral Earth Pressures: Earth pressures will be influenced by structural design of the walls, conditions of
wall restraint, methods of construction, wetting of backfill materials, and/or compaction and the strength
of the materials being restrained. Loads that should be considered by the structural engineer on walls are
shown below.
Active earth pressure is commonly used for design of freestanding cantilever retaining walls and assumes
wall movement. The "at-rest" condition assumes no wall rotation. Walls with unbalanced backfill levels
on opposite sides (i.e. crawlspace, basement, site retaining walls) should be designed for earth pressures
at least equal to those indicated in the following table. The recommended design lateral earth pressures
do not include a factor of safety and do not provide for possible hydrostatic pressure on the walls.
EARTH PRESSURE COEFFICIENTS
Earth Pressure
Conditions Coefficient For Backfill Type
Equivalent
Fluid Pressure
(pcf)
Surcharge
Pressure, P1
(psf)
Earth Pressure,
P2
(psf)
Active (Ka) On-site clay soils - 0.38 45 (0.38)S (45)H
At-Rest (Ko) On-site clay soils - 0.54 65 (0.54)S (65)H
Passive (Kp) On-site clay soils - 2.3 275 --- ---
Conditions applicable to the above conditions include:
• for active earth pressure, wall must rotate about base, with top lateral movements 0.01 Z to
0.02 Z, where Z is wall height
• for passive earth pressure, wall must move horizontally to mobilize resistance
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• uniform surcharge, where S is surcharge pressure
• in-situ soil backfill weight a maximum of 120 pcf
• horizontal backfill, compacted to at least 95 percent of standard Proctor maximum dry density
• loading from heavy compaction equipment not included
• no groundwater acting on wall
• no safety factor included
• ignore passive pressure in frost zone
Backfill placed against structures may consist of the on-site soils processed with maximum particle sizes
on the order of 4 to 6 inches. To calculate the resistance to sliding, a value of 0.35 may be used as the
coefficient of friction between the footing and the underlying soil.
If the project contains any foundation walls that will retain unbalanced soil loads (i.e. crawlspace,
basement foundations), we recommend installation of a drainage system at the base of the retained soil
mass to control the water level behind the wall. If this is not possible, then combined hydrostatic and
lateral earth pressures should be calculated for lean clay backfill using an equivalent fluid weighing 90 and
100 pcf for active and at-rest conditions, respectively. These pressures do not include the influence of
surcharge, equipment or floor loading, which should be added. Heavy equipment should not operate
within a distance closer than the exposed height of retaining walls to prevent lateral pressures more than
those provided.
Seismic Considerations: Based on the subsurface conditions encountered in the test holes drilled on the
site, we estimate that a Site Class D is appropriate for the site according to the 2021 International Building
Code (Section 1613 referencing ASCE 7, Chapter 20). This parameter was estimated based on
extrapolation of data beyond the deepest depth explored, using methods allowed by the code. Actual
shear wave velocity testing/analysis and/or exploration to 100 feet was not performed.
Interior Slab-on-Grade Floors: Based on the properties of the existing fill soils encountered in our borings,
we believe there is low risk of excessive floor slab movement on this site. We have recommended
additional evaluation of the fill soils be performed as part of site preparation. Provided that any unsuitable
materials (if any) are mitigated, we estimate that floor slab movement will be limited to amounts normally
tolerable in this region.
When bearing on approved, low-expansive on-site fill soils, we estimate that floor slab movement will be
limited to about 1 inch on this site. If this degree of movement cannot be tolerated, movement could be
further reduced by replacing the upper three feet of on-site soils with imported CDOT Class 1 structural
fill. Suspended, structural floors could also be considered, but in our opinion, the cost of such systems
does not justify the incremental reduction in movement risk.
The movement estimates outlined above assume that the other recommendations in this report are
followed. As discussed, additional movement could occur should the subsurface soils become wetted to
significant depths, which could result in potential excessive movement causing uneven floor slabs and
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Geotechnical Engineering and Materials Testing
severe cracking. We typically recommend minimal landscaping be installed and downspouts be hard-
piped to storm sewer systems as described in subsequent sections of this report.
Additional floor slab design and construction recommendations are as follows:
• Moisture condition and recompact the upper 12 inches of the slab subgrade soils just prior to
concrete placement
• Positive separations and/or isolation joints should be provided between slabs and all foundations,
columns or utility lines to allow independent movement. Where the design requires that the floor
slab be structurally connected (tied in) to foundation walls, we recommend that control joints be
used to allow for floor slab movement while limiting the stress imparted to the foundation by the
floor slab. Similar details should be considered where the design will include tied exterior
flatwork.
• Control joints should be provided in slabs to control the location and extent of cracking in
accordance with current ACI design standards.
• A minimum 2-inch void space should be constructed above or below non-bearing partition walls
placed on the floor slab. This typically involves suspending drywall 3 to 4 inches above the slab
and utilizing a “bottom plate” in the framing to which baseboards can be connected (no
connection from baseboards to drywall). Corner beads and other elements must also be isolated
from the slab. If this void space is constructed as a slip joint at the top of the wall, some minor
drywall cracking could occur due to slab movement, prior to mobilization of this joint. Partition
walls should be isolated from suspended ceilings.
• Doorjambs and frames within partition walls should be trimmed to allow for floor slab movement
and avoid potential distortion (we understand that about ½-inch is typical).
• The thickness of the partition void and gap at the base of door frames should be checked
periodically and adjusted as needed to maintain a void space and avoid transferring slab
movement to upper-level framing.
• Interior trench backfill placed beneath slabs should be compacted in accordance with
recommended specifications outlined below.
• The use of a vapor retarder/barrier should be considered beneath concrete slabs on grade that
will be covered with wood, tile, carpet or other moisture sensitive or impervious coverings, or
when the slab will support equipment sensitive to moisture. When conditions warrant the use of
a vapor retarder/barrier, the slab designer and slab contractor should refer to ACI 302 for
procedures and cautions regarding the use and placement of a vapor retarder/barrier.
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• Floor slabs should not be constructed on frozen subgrade.
• Other design and construction considerations, as outlined in Section 302.1R of the ACI Design
Manual, are recommended.
Below-Grade Construction: Below-grade construction (basement or crawlspace areas) is not anticipated
as a part of this development. If basement or crawlspace construction (or other below-grade interior
building spaces) are planned, additional recommendations and subsurface drainage plans will need to be
developed. All walls which retain earth will need to include provisions for drainage as discussed below.
Private Pavement Thickness Design and Construction: Design of private pavements for the project is based
on the procedures outlined in the 1993 Guideline for Design of Pavement Structures by the American
Association of State Highway and Transportation Officials (AASHTO). The AASHTO design method takes into
account several variables, including subgrade soil and traffic conditions. If public roadway construction is to
be included in the project, additional geotechnical investigation and a formal pavement design may be
required for those improvements in accordance with Town of Fort Collins Standards.
• Subgrade Soils: As discussed, undocumented fill soils are present at the site. These materials can
present a greater than normal risk of post-construction movement of pavements and flatwork
supported on these materials. In our experience, it is common for project owners to forego the costs
associated with mitigation (extensive removal and recompaction) and instead reserve those funds to
perform pavement maintenance in areas where excessive distress occurs. Since pavements
associated with the project are privately maintained, the owner may choose to only perform typical
subgrade preparation. At a minimum, we recommend a thorough proofroll of the subgrade soils to
help identify soft, loose or otherwise unsuitable soil conditions.
• Subgrade Soil: The near-surface materials at the site are variable and include clayey sands and sandy lean
clays; these soil types are considered to provide for fair to poor pavement support. Based on the
properties of the poorer clay materials, we estimated a design R-value of 5 for use in flexible pavement
(asphalt) thickness design. Likewise, modulus of subgrade reaction (K-value) of 100 pounds per cubic
inch (pci) was used for design of rigid concrete pavements.
• Assumed Design Traffic Conditions: We assume that pavements associated with the project will include
private heavy-duty drive lanes, main access driveways, fire lanes, and light-duty surface parking for
automobiles and light trucks. Private pavements will be surfaced with either asphalt concrete or Portland
cement concrete. As discussed, any improvements to adjacent public roadways will need to be designed
and constructed according to the governing standards.
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Geotechnical Engineering and Materials Testing
Based on our experience with similar projects, the following traffic criteria were used for determining
pavement thicknesses using a design life of 20 years:
• Driveways and parking stalls - maximum daily traffic of 1,000 cars per day (equivalent single-axle
loads, ESAL's of 22,000)
• Main on-site access drives and fire lanes – up to 10 trips by single-axle delivery trucks (box trucks)
per day, a maximum of 1 trash truck per day, occasional fire truck traffic (85,000 pounds
maximum) plus maximum daily traffic of 1,000 cars per day (73,000 ESAL’s)
• Heavy-duty delivery truck access – traffic above plus up to up to three vehicle-transport or semi-
trucks per day (109,500 ESAL’s)
The owner should review these assumptions, and we should be contacted to confirm or modify these
resulting pavement sections, if needed.
• Pavement Sections: For flexible pavement design a drainage coefficient of 1.0, a terminal
serviceability index of 2.0 (2.5 for truck access), and an inherent reliability of 80 percent (90 percent
for truck access) were used. Using, the appropriate ESAL values, environmental criteria and other
factors, the design structural numbers (SN) of the pavement sections were determined using the 1993
AASHTO design equation.
In addition to the flexible pavement design analyses, a rigid pavement design analysis was completed
based upon AASHTO design procedures. Along with soil and traffic conditions, rigid pavement design
is based on the Modulus of Rupture of the concrete, and other factors previously outlined. A modulus
of rupture of 650 psi (working stress 488 psi) was used for pavement concrete. The rigid pavement
thickness for each traffic category was determined using the AASHTO design equation.
We have considered full depth-asphalt paving, a composite section with asphalt concrete over
aggregate base course, and full depth rigid concrete sections. Alternatives for flexible and rigid
pavements are summarized for each traffic area as follows:
Private Pavement Traffic
Area Alternative
Recommended Pavement Thickness (Inches)
Hot-Mix Asphalt
(HMA)
Aggregate Base
Course
(ABC)
Portland Cement
Concrete
(PCC)
Automobile Parking and
Standard-Duty
Automobile and Light Truck
Parking Only
A 4 6 --
B 3-½ 8 --
C -- -- 5
Main Access Drives, and
Fire lanes
Private On-site Drives, Fire
Lanes, box-truck access
A 5 6 --
B 4 10 --
C -- -- 6
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Geotechnical Engineering and Materials Testing
Private Pavement Traffic
Area Alternative
Recommended Pavement Thickness (Inches)
Hot-Mix Asphalt
(HMA)
Aggregate Base
Course
(ABC)
Portland Cement
Concrete
(PCC)
Heavy-Duty Vehicle
Delivery and Semi-Truck
Access
A 6 6 --
B 5 10 --
C -- -- 7
A minimum 6-inch thickness of Portland cement concrete pavement (PCC) is recommended at the
location of dumpsters where trash trucks park and load and should be considered in other areas
supporting heavy truck traffic. Each alternative should be investigated with respect to current
material availability and economic conditions.
• Temporary Unpaved Access Drives: In our opinion, the use of aggregate base course or crushed stone
may be considered for use in constructing temporary access roads for construction traffic and/or all-
weather fire truck access. To provide an all-weather surface, we recommend that the section include
a minimum of 12 inches of aggregate base course (CDOT Class 5 or 6) or a minimum of 8 inches of 3-
inch minus crushed aggregate (or recycled concrete). In our opinion, these sections would be suitable
for the support of delivery and concrete trucks and occasional fire truck access (85,000 pounds
maximum) for the anticipated duration of a typical project of this magnitude. The contractor should
be responsible for monitoring the condition of unpaved drive lanes, including the repair and
maintenance of the drive lanes throughout its use to provide the required access. We believe it is
likely that these aggregate materials will be “contaminated” with soil and other constituents over the
course of construction; therefore, the aggregate materials should not be considered part of the final
pavement section unless otherwise evaluated and approved by the Geotechnical Engineer.
• Subgrade Preparation: We recommend the pavement areas be rough graded and then thoroughly
proof rolled with a loaded tandem axle dump truck, water truck, or other heavy equipment approved
by the observing engineer prior to final grading and paving. Particular attention should be paid to
high traffic areas that were rutted and disturbed earlier and to areas where backfilled trenches are
located. Areas where unsuitable conditions are located should be repaired by removing and replacing
the materials with properly compacted engineered fills.
At a minimum, to provide a more uniform subgrade for site pavements, we recommend that all
pavements be constructed on a minimum of 12 inches of properly moisture conditioned and
recompacted on-site soils. Confirmation of the moisture content and compaction level of the
subgrade soils should be confirmed within 24 hours prior to paving.
• Pavement Materials: Aggregate base course (if used on the site) should consist of a blend of sand and
gravel which meets strict specifications for quality and gradation. Use of materials meeting Colorado
Department of Transportation (CDOT) Class 5 or 6 specifications is recommended for base course.
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Aggregate base course (ABC) should be placed in lifts not exceeding 6 inches and compacted to a
minimum of 95 percent of the standard Proctor density (ASTM D698).
Hot-mix asphalt (HMA) should be composed of a mixture of aggregate, filler and additives (if required)
and approved bituminous material. The HMA should conform to approved mix designs stating the
Hveem properties, optimum asphalt content, and job mix formula and recommended mixing and
placing temperatures. Aggregate used in HMA should meet particular gradations. Material meeting
CDOT Grading S, SG (bottom-lift only) or SX (top-lift only) specifications or equivalent is recommended
for HMA. Mix designs should be submitted prior to construction to verify their adequacy. HMA should
be placed in appropriate lifts (CDOT specs per table below) and compacted within a range of 92 to 96
percent of the theoretical maximum (Rice) density (ASTM D2041).
CDOT specifications for asphalt pavement lift thickness are summarized below based on mix
aggregate size:
CDOT HMA Grade Nominal Maximum
Aggregate Size
Structural Layer Lift Thickness (Inches)
Minimum Maximum
SX 1/2“ 2.00 3.00
S 3/4” 2.25 3.50
SG 1” 3.00 4.00
* Alternative lift thicknesses can be considered provided the contractor uses equipment and
procedures to obtain the required compaction.
Where rigid pavements are used, the concrete should meet CDOT Class P requirements and be
obtained from an approved mix design with the following minimum properties:
• Modulus of Rupture @ 28 days ....................................................................... 650 psi minimum
• Strength Requirements .............................................................................................. ASTM C94
• Cement Type ..................................................................................................... Type II Portland
• Entrained Air Content ..................................................................................................... 6 to 8%
• Concrete Aggregate ............................................................... ASTM C33 and CDOT Section 703
Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 minutes from
the time the water is added to the mix. Other specifications outlined by CDOT should be followed.
Longitudinal and transverse joints should be provided as needed in concrete pavements for
expansion/contraction and isolation. The location and extent of joints should be based upon the final
pavement geometry. Sawed joints should be cut within 24 hours of concrete placement and should
be a minimum of 25 percent of slab thickness plus 1/4 inch. All joints should be sealed to prevent
entry of foreign material and doweled where necessary for load transfer.
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• Compliance: Recommendations for pavement design and construction presented depend upon
compliance with recommended material specifications. To assess compliance, observation and testing
should be performed under the observation of the geotechnical engineer.
• Pavement Performance: Future performance of pavements constructed on the subgrade at this site
will be dependent upon several factors, including:
• Maintaining stable moisture content of the subgrade soils.
• Providing for a planned program of preventative maintenance.
The performance of all pavements can be enhanced by minimizing excess moisture, which can reach
the subgrade soils. The following recommendations should be considered at minimum:
• Site grading at a minimum 2 percent grade onto or away from pavements.
• Water should not be allowed to pond behind curbs.
• Compaction of any utility trenches for landscaped areas to the same criteria as the pavement
subgrade.
• Sealing all landscaped areas in or adjacent to pavements to minimize or prevent moisture
migration to subgrade soils.
• Placing compacted backfill against the exterior side of curb and gutter.
• Placing curb, gutter and/or sidewalk directly on subgrade soils without the use of base course
materials.
Preventative maintenance should be planned and provided for an ongoing pavement management
program in order to enhance future pavement performance. Preventative maintenance activities are
intended to slow the rate of pavement deterioration and to preserve the pavement investment.
Preventative maintenance consists of both localized maintenance (e.g. crack sealing and patching)
and global maintenance (e.g. surface sealing). Preventative maintenance is usually the first priority
when implementing a planned pavement maintenance program and provides the highest return on
investment for pavements.
Final Grading, Landscaping, and Surface Drainage: All grades must be adjusted to provide positive
drainage away from structures during construction and maintained throughout the life of the proposed
project. Water permitted to pond near or adjacent to the perimeter of the structures (either during or
post-construction) can result in significantly higher soil movements than those discussed in this report.
As a result, any estimations of potential movement described in this report cannot be relied upon if
positive drainage is not obtained and maintained, and water is allowed to infiltrate the fill and/or
subgrade. Infiltration of water into utility or foundation excavations must be prevented during
construction.
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Geotechnical Engineering and Materials Testing
We recommend that exposed ground be sloped at a minimum of 10 percent grade for at least 10 feet
beyond the perimeter of the buildings, where possible. We understand that this may not be feasible in
all unpaved areas due to ADA access requirements and other required design features. In these areas,
exterior grades should be sloped as much as possible down to area drain systems, swales, and/or sidewalk
chases to facilitate drainage. In all cases, the grade should slope a minimum of 5 percent away from
structures in accordance with the applicable building code.
Downspouts should also be connected to area drain systems to help reduce wetting, if possible. If this is
not possible, roof drain flows should be directed onto pavements or discharge a minimum of 5 feet away
from the structure a through the use of splash blocks or downspout extensions.
Backfill against foundations, exterior walls and in utility and sprinkler line trenches should be well
compacted and free of all construction debris to reduce the possibility of moisture infiltration. After
building construction and prior to project completion, we recommend that verification of final grading
be performed to document that positive drainage, as described above, has been achieved. This is
especially important in areas where heating and cooling units are placed in close proximity to the
buildings.
Landscaped irrigation adjacent to foundations should be eliminated where possible or minimized to only
limited drip irrigation. Sprinkler mains and spray heads should be located a minimum of 5 feet away
from the buildings. We recommend the use of Xeric landscaping, requiring little or no irrigation, be used
within 5 feet of foundations. If drip irrigation is required in this zone, systems should be timed to provide
only the amount of water needed to sustain growth. Irrigation systems should be frequently checked for
proper performance and any breakages fixed as soon as possible. Planters located adjacent to the
structure should preferably be self-contained (planter boxes, potted landscaping, etc.), if possible.
Additional Design and Construction Considerations:
• Exterior Slab Design and Construction: Flatwork and pavements will be subject to post construction
movement due to backfill settlement and/or soil/frost heave. In our experience, it is not feasible to
eliminate the potential for movement of exterior flatwork. The amount of movement will be related
to the compactive effort used when the fill soils are placed and future wetting of the subgrade soils.
The potential for damage would be greatest where exterior slabs are constructed adjacent to the
building or other structural elements.
To reduce the potential for damage, we recommend:
• exterior slabs in critical areas be supported on a zone of recompacted soils as recommended
for pavement areas.
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Geotechnical Engineering and Materials Testing
• supporting of flatwork at building entrances and other critical areas on haunches attached by
the building foundations.
• placement of effective control joints on relatively close centers and isolation joints between
slabs and other structural elements.
• provision for adequate drainage in areas adjoining the slabs.
• use of designs which allow vertical movement between the exterior slabs and adjoining
structural elements.
• Underground Utility Systems: Details regarding the underground stormwater detention systems
were not available at the time of this study; however, these systems commonly include some type of
chambered system installed up to 8 to 10 feet below new pavements. Boring Nos. 6 and 7 were
advance in areas designated for these systems. Subsurface conditions at Boring No. 6 included fill and
native clayey sands and lean clays extending to a depth of about 12 feet. Soft lean clay soils were
encountered at this depth and groundwater was measured at a depth of about 14 feet below existing
site grade. Conditions at Boring No. 7 appeared to be more conducive to supporting underground
detention along with the potential for infiltration-type systems. We are available to provide additional
consultation in the design of such systems, upon request.
All underground utility lines penetrating below foundations should be installed deep enough to avoid
direct contact with foundations or be designed with flexible couplings (if available), so minor
deviations in alignment do not result in breakage or distress. Utility knockouts in foundation walls
should be oversized to accommodate differential movements.
It is strongly recommended that a representative of the geotechnical engineer provide full-time
observation and compaction testing of trench backfill within building and pavement areas.
• Concrete Corrosion Protection: Select samples of soils likely to be in contact with project concrete
were tested for the presence of water-soluble sulfates in order to determine corrosion characteristics
and the appropriate concrete mixture. Results of testing indicate these materials are categorized as
American Concrete Institute (ACI) Sulfate Exposure Class S0. However, for increased protection from
concrete sulfate attack, we recommend project concrete be designed for ACI Sulfate Exposure Class
S1 in accordance with Chapter 19 of the ACI design manual, Building Code Requirements for
Structural Concrete (ACI 318-14), as summarized in the table below.
ACI Sulfate
Exposure Class
Portland Cement Type
(ASTM C150)
Maximum
Water/Cement Ratio
Minimum Concrete
Compressive Strength
(psi)
S1 II (or equivalent) 0.50 4,000
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Geotechnical Engineering and Materials Testing
GENERAL COMMENTS
CGG should be retained to review the final design plans and specifications so comments can be made
regarding interpretation and implementation of our geotechnical recommendations in the design and
specifications. CGG should also be retained to provide testing and observation during the excavation,
grading, foundation and construction phases of the project.
The analysis and recommendations presented in this report are based upon the data obtained from the
borings performed at the indicated locations and from other information discussed in this report. This
report does not reflect variations that may occur between borings, across the site, or due to the modifying
effects of weather. The nature and extent of such variations may not become evident until during or after
construction. If variations appear, we should be immediately notified so that further evaluation and
supplemental recommendations can be provided.
The scope of services for this project does not include, either specifically or by implication, any
environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or
prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential
for such contamination or pollution, other studies should be undertaken.
This report has been prepared for the exclusive use of our client for specific application to the project
discussed and has been prepared in accordance with generally accepted geotechnical engineering
practices. No warranties, either express or implied, are intended or made. Site safety, excavation support,
and dewatering requirements are the responsibility of others. In the event that changes are planned in
the nature, design, or location of the project as outlined in this report, the conclusions and
recommendations contained in this report shall not be considered valid unless CGG reviews the changes,
and either verifies or modifies the conclusions of this report in writing.
APPENDIX A
BORING LOCATION DIAGRAM
BORING LOGS
PROPOSED BORING LOCATIONS
Cole Garner Geotechnical
1070 W. 124th Ave., Suite 300
Westminster, CO 80234
(303) 996-2999
1 BORING LOCATION DIAGRAM
PEDERSEN TOYOTA EXPANSION
4455 SOUTH COLLEGE AVENUE
FORT COLLIINS, COLORADO
CGG PROJECT NO. 25.22.116
1
2
3
4
5
6
7
8
9
10 11
CB
CB
CB
CB
CB
SC
SC
SC
CL
-
6 / 12
23 / 12
21 / 12
10 / 12
50 / 10
120
133
121
109
114
8.8
4.2
5.2
22.9
17.9
100
100
100
100
100
CONCRETE, 6 inches concrete pavement
FILL - CLAYEY SAND, fine- to coarse-grained, with fine gravel,
reddish-brown, moist, loose
CLAYEY SAND, fine- to coarse-grained, with gravel, red, dry to
moist, medium dense
LEAN CLAY with SAND, red to reddish-brown, grey, moist,
medium stiff
INTERBEDDED CLAYSTONE and SANDSTONE BEDROCK,
brown, olive, grey, pink, moist, medium hard
Approximate bottom of borehole at 25.0 feet.
0.5
7
16
22
25
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS ConcreteDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING 20.00 ft
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
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MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 1
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
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Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
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CB
CB
CB
SC
SC
SC
-
-
7 / 12
27 / 12
10 / 12
50 / 5
50 / 1
128
123
116
108
-0.3/1000
7.8
2.9
8.3
14.6
18.0
100
100
100
100
100
ASPHALT, 7 inch pavement
FILL - CLAYEY SAND, fine- to coarse-grained, with fine gravel,
brown to dark brown, reddish brown, dry to moist, loose
CLAYEY SAND, fine- to coarse-grained, with fine gravel, fine-
to coarse-grained, red, dry to moist, loose to medium dense
INTERBEDDED CLAYSTONE and SANDSTONE BEDROCK,
brown, olive, grey, iron stained, moist, very hard
Refusal at 25.0 feet.
Approximate bottom of borehole at 25.0 feet.
0.5
7
17
25
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS AsphaltDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING 19.00 ft
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
SA
M
P
L
E
T
Y
P
E
US
C
S
S
Y
M
B
O
L
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
20
25
PE
N
E
T
R
A
T
I
O
N
bl
o
w
s
/
i
n
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
SW
E
L
L
-
C
O
N
S
O
L
/S
U
R
C
H
A
R
G
E
LO
A
D
,
%
p
s
f
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
RE
C
O
V
E
R
Y
%
MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 2
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GE
O
T
E
C
H
B
H
C
O
L
U
M
N
S
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
1
:
5
4
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
CB
CB
CB
CB
CB
CB
CB
SC
SC
SC
SC
-
-
-
14 / 12
28 / 12
45 / 12
9 / 12
29 / 12
50 / 6
50 / 2
133
138
142
136
8.0
4.3
3.5
8.9
20.0
15.1
100
100
100
0
100
100
100
ASPHALT, 7 inch pavement
FILL - CLAYEY SAND, fine- to coarse-grained, with asphalt
fragments and gravel, red, brown, dry to moist, loose
CLAYEY SAND, fine- to coarse-grained, with gravel, red, light
pink, tan, moist to dry, loose to medium dense
INTERBEDDED CLAYSTONE and SANDSTONE BEDROCK,
fine-grained, olive, dark grey, iron stained, firm to very hard
Approximate bottom of borehole at 35.0 feet.
0.5
9
24
35
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS AsphaltDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING 18.00 ft
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
SA
M
P
L
E
T
Y
P
E
US
C
S
S
Y
M
B
O
L
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
20
25
30
35
PE
N
E
T
R
A
T
I
O
N
bl
o
w
s
/
i
n
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
SW
E
L
L
-
C
O
N
S
O
L
/S
U
R
C
H
A
R
G
E
LO
A
D
,
%
p
s
f
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
RE
C
O
V
E
R
Y
%
MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 3
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GE
O
T
E
C
H
B
H
C
O
L
U
M
N
S
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
1
:
5
4
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
CB
CB
CB
CB
CB
SC
SC
CL
CL
CL
8 / 12
33 / 12
11 / 12
7 / 12
8 / 12
121
127
109
100
108
+0.2/500
-0.1/500
-0.8/1000
8.9
3.2
17.6
26.8
22.9
100
100
100
100
100
ASPHALT, 8 inches of pavement
FILL - CLAYEY SAND, fine- to coarse-grained, with asphalt
graments and gravel, red, brown, dry to moist, loose
CLAYEY SAND, fine- to coarse-grained, red, pink, dry to moist,
medium dense
SANDY LEAN CLAY, light brown, grey, reddish-brown, red, iron
stained, moist, medium stiff to stiff
Approximate bottom of borehole at 25.0 feet.
0.5
9
11
25
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS AsphaltDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING 18.00 ft
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
SA
M
P
L
E
T
Y
P
E
US
C
S
S
Y
M
B
O
L
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
20
25
PE
N
E
T
R
A
T
I
O
N
bl
o
w
s
/
i
n
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
SW
E
L
L
-
C
O
N
S
O
L
/S
U
R
C
H
A
R
G
E
LO
A
D
,
%
p
s
f
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
RE
C
O
V
E
R
Y
%
MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 4
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GE
O
T
E
C
H
B
H
C
O
L
U
M
N
S
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
1
:
5
4
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
CB
CB
CB
CB
SC/CL
CL
SC/SM
SC/SM
11 / 12
10 / 12
18 / 12
16 / 12
107
115
117
+0.4/200
-0.1/500
18.9
11.1
2.9
14.2
100
100
100
100
ASPHALT, 8 inches of pavement
FILL - CLAYEY SAND to SANDY LEAN CLAY, dark brown,
red, moist, medium stiff to stiff
CLAYEY to SILTY CLAY, fine- to coarse-grained, with gravel,
red, pink, moist, medium dense
Approximate bottom of borehole at 15.0 feet.
0.5
7
15
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS AsphaltDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING None
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
SA
M
P
L
E
T
Y
P
E
US
C
S
S
Y
M
B
O
L
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
PE
N
E
T
R
A
T
I
O
N
bl
o
w
s
/
i
n
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
SW
E
L
L
-
C
O
N
S
O
L
/S
U
R
C
H
A
R
G
E
LO
A
D
,
%
p
s
f
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
RE
C
O
V
E
R
Y
%
MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 5
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GE
O
T
E
C
H
B
H
C
O
L
U
M
N
S
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
1
:
5
4
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
CB
CB
CB
CB
SC
CL
SC
CL
8 / 12
13 / 12
18 / 12
5 / 12
109
106
125
95
+0.7/500
15.4
19.5
9.4
29.8
100
100
100
100
ASPHALT, 10 inches of pavement
FILL - CLAYEY SAND, fine- to coarse-grained, with gravel and
asphalt fragments, reddish-brown, dry to moist, loose
FILL - LEAN CLAY with SAND, dark brown, moist, stiff
CLAYEY SAND, fine-grained, red, moist, medium dense
LEAN CLAY, trace sand, pink, moist to wet, soft
Approximate bottom of borehole at 15.0 feet.
0.83
3
8
12
15
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS AsphaltDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING 14.00 ft
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
SA
M
P
L
E
T
Y
P
E
US
C
S
S
Y
M
B
O
L
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
PE
N
E
T
R
A
T
I
O
N
bl
o
w
s
/
i
n
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
SW
E
L
L
-
C
O
N
S
O
L
/S
U
R
C
H
A
R
G
E
LO
A
D
,
%
p
s
f
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
RE
C
O
V
E
R
Y
%
MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 6
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GE
O
T
E
C
H
B
H
C
O
L
U
M
N
S
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
1
:
5
4
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
CB
CB
CB
CB
SC
SC
SM
SM
5 / 12
5 / 12
15 / 12
8 / 12
122
120
127 -0.4/1000
8.2
11.2
4.9
7.5
100
100
100
100
ASPHALT, 7 inches of pavement
FILL - CLAYEY SAND, fine- to coarse-grained, with gravel and
asphalt fragments, varies to SANDY LEAN CLAY, red, dry to
moist, very loose
SILTY SAND, fine- to medium-grained, with gravel, red, dry to
moist, loose to medium dense
Approximate bottom of borehole at 15.0 feet.
0.5
9
15
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS AsphaltDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING None
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
SA
M
P
L
E
T
Y
P
E
US
C
S
S
Y
M
B
O
L
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
10
15
PE
N
E
T
R
A
T
I
O
N
bl
o
w
s
/
i
n
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
SW
E
L
L
-
C
O
N
S
O
L
/S
U
R
C
H
A
R
G
E
LO
A
D
,
%
p
s
f
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
RE
C
O
V
E
R
Y
%
MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 7
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GE
O
T
E
C
H
B
H
C
O
L
U
M
N
S
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
1
:
5
4
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
CB
CB
SC
SC
5 / 12
6 / 12
12511.7
5.1
100
100
ASPHALT, 7 inches of pavement
FILL - CLAYEY SAND, fine- to coarse-grained, with asphalt
fragments and gravel, red, dry to moist, very loose to loose
Approximate bottom of borehole at 5.0 feet.
0.5
5
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS AsphaltDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING None
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
SA
M
P
L
E
T
Y
P
E
US
C
S
S
Y
M
B
O
L
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
PE
N
E
T
R
A
T
I
O
N
bl
o
w
s
/
i
n
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
SW
E
L
L
-
C
O
N
S
O
L
/S
U
R
C
H
A
R
G
E
LO
A
D
,
%
p
s
f
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
RE
C
O
V
E
R
Y
%
MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 8
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GE
O
T
E
C
H
B
H
C
O
L
U
M
N
S
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
1
:
5
4
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
CB
CB
SC-SM
SC-SM
17 / 12
15 / 12
127
120
10.0
13.2
100
100
ASPHALT, 7 inches of pavement
FILL - CLAYEY to SILTY SAND, fine- to coarse-grained, with
asphalt fragments and gravel, red, dry to moist, medium dense
Approximate bottom of borehole at 5.0 feet.
0.5
5
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS AsphaltDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING None
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
SA
M
P
L
E
T
Y
P
E
US
C
S
S
Y
M
B
O
L
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
PE
N
E
T
R
A
T
I
O
N
bl
o
w
s
/
i
n
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
SW
E
L
L
-
C
O
N
S
O
L
/S
U
R
C
H
A
R
G
E
LO
A
D
,
%
p
s
f
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
RE
C
O
V
E
R
Y
%
MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 9
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GE
O
T
E
C
H
B
H
C
O
L
U
M
N
S
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
1
:
5
4
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
CB
CB
SC
SC
14 / 12
15 / 12
125
124
+0.4/2009.6
8.3
100
100
ASPHALT, 8 inches of pavement
FILL - CLAYEY SAND, fine- to coarse-grained, with gravel,
brown, red, moist, loose to medium dense
Approximate bottom of borehole at 5.0 feet.
0.67
5
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS AsphaltDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING None
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
SA
M
P
L
E
T
Y
P
E
US
C
S
S
Y
M
B
O
L
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
PE
N
E
T
R
A
T
I
O
N
bl
o
w
s
/
i
n
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
SW
E
L
L
-
C
O
N
S
O
L
/S
U
R
C
H
A
R
G
E
LO
A
D
,
%
p
s
f
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
RE
C
O
V
E
R
Y
%
MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 10
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GE
O
T
E
C
H
B
H
C
O
L
U
M
N
S
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
1
:
5
4
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
CB
CB
CL
CL
19 / 12
18 / 12
117
126
+1.1/20014.7
9.2
100
100
CONCRETE, 8 inches concrete pavement
FILL - SANDY LEAN CLAY, with gravel, reddish-brown, moist,
stiff to very stiff
Approximate bottom of borehole at 5.0 feet.
0.67
5
DRILLING METHOD CME-55 / Solid Stem Auger
DATE STARTED 7/29/25
GROUND WATER LEVELS:
SURFACE CONDITIONS AsphaltDRILLING CONTRACTOR Vine Laboratories
COMPLETED 7/29/25
LOGGED BY AL CHECKED BY AG
HAMMER TYPE Automatic
PROPOSED ELEV.Not Provided
DURING DRILLING None
AFTER DRILLING Backfilled and Patched - 7/29/25
GROUND SURFACE ELEV.Not Provided
SA
M
P
L
E
T
Y
P
E
US
C
S
S
Y
M
B
O
L
GR
A
P
H
I
C
LO
G
DE
P
T
H
(f
t
)
0
5
PE
N
E
T
R
A
T
I
O
N
bl
o
w
s
/
i
n
DR
Y
U
N
I
T
W
T
.
(p
c
f
)
SW
E
L
L
-
C
O
N
S
O
L
/S
U
R
C
H
A
R
G
E
LO
A
D
,
%
p
s
f
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
RE
C
O
V
E
R
Y
%
MATERIAL DESCRIPTION
PAGE 1 OF 1
BORING NUMBER 11
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GE
O
T
E
C
H
B
H
C
O
L
U
M
N
S
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
1
:
5
4
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
APPENDIX B
LABORATORY TEST RESULTS
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.1 1 10 100
CO
N
S
O
L
I
D
A
T
I
O
N
(
-
)
%
S
W
E
L
L
(
+
)
APPLIED PRESSURE, ksf
SWELL/CONSOLIDATION TEST
123 3
Date: 8/7/25Date: 8/7/25Note: Water Added to Sample at 1000 psf.
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
BOREHOLE DEPTH
2 9.0 CLAYEY SAND
Classification MC%
CO
N
S
O
L
S
T
R
A
I
N
S
I
N
G
L
E
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
3
:
3
3
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.1 1 10 100
CO
N
S
O
L
I
D
A
T
I
O
N
(
-
)
%
S
W
E
L
L
(
+
)
APPLIED PRESSURE, ksf
SWELL/CONSOLIDATION TEST
121 9
Date: 8/7/25Date: 8/7/25Note: Water Added to Sample at 500 psf.
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
BOREHOLE DEPTH
4 4.0 FILL-CLAYEY SAND
Classification MC%
CO
N
S
O
L
S
T
R
A
I
N
S
I
N
G
L
E
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
3
:
3
3
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.1 1 10 100
CO
N
S
O
L
I
D
A
T
I
O
N
(
-
)
%
S
W
E
L
L
(
+
)
APPLIED PRESSURE, ksf
SWELL/CONSOLIDATION TEST
127 3
Date: 8/7/25Date: 8/7/25Note: Water Added to Sample at 500 psf.
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
BOREHOLE DEPTH
4 9.0 CLAYEY SAND
Classification MC%
CO
N
S
O
L
S
T
R
A
I
N
S
I
N
G
L
E
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
3
:
3
3
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.1 1 10 100
CO
N
S
O
L
I
D
A
T
I
O
N
(
-
)
%
S
W
E
L
L
(
+
)
APPLIED PRESSURE, ksf
SWELL/CONSOLIDATION TEST
109 18
Date: 8/7/25Date: 8/7/25Note: Water Added to Sample at 1000 psf.
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
BOREHOLE DEPTH
4 14.0 SANDY LEAN CLAY
Classification MC%
CO
N
S
O
L
S
T
R
A
I
N
S
I
N
G
L
E
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
3
:
3
3
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.1 1 10 100
CO
N
S
O
L
I
D
A
T
I
O
N
(
-
)
%
S
W
E
L
L
(
+
)
APPLIED PRESSURE, ksf
SWELL/CONSOLIDATION TEST
107 19
Date: 8/7/25Date: 8/7/25Note: Water Added to Sample at 200 psf.
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
BOREHOLE DEPTH
5 2.0 FILL-CLAYEY SAND to SANDY LEAN CLAY
Classification MC%
CO
N
S
O
L
S
T
R
A
I
N
S
I
N
G
L
E
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
3
:
3
3
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.1 1 10 100
CO
N
S
O
L
I
D
A
T
I
O
N
(
-
)
%
S
W
E
L
L
(
+
)
APPLIED PRESSURE, ksf
SWELL/CONSOLIDATION TEST
115 11
Date: 8/7/25Date: 8/7/25Note: Water Added to Sample at 500 psf.
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
BOREHOLE DEPTH
5 4.0 FILL-CLAYEY SAND to SANDY LEAN CLAY
Classification MC%
CO
N
S
O
L
S
T
R
A
I
N
S
I
N
G
L
E
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
3
:
3
3
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.1 1 10 100
CO
N
S
O
L
I
D
A
T
I
O
N
(
-
)
%
S
W
E
L
L
(
+
)
APPLIED PRESSURE, ksf
SWELL/CONSOLIDATION TEST
106 20
Date: 8/7/25Date: 8/7/25Note: Water Added to Sample at 500 psf.
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
BOREHOLE DEPTH
6 4.0 FILL-LEAN CLAY with SAND
Classification MC%
CO
N
S
O
L
S
T
R
A
I
N
S
I
N
G
L
E
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
3
:
3
3
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
J
E
C
T
S
G
E
O
2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
E
D
E
R
S
O
N
T
O
Y
O
T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.1 1 10 100
CO
N
S
O
L
I
D
A
T
I
O
N
(
-
)
%
S
W
E
L
L
(
+
)
APPLIED PRESSURE, ksf
SWELL/CONSOLIDATION TEST
127 7
Date: 8/7/25Date: 8/7/25Note: Water Added to Sample at 1000 psf.
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
BOREHOLE DEPTH
7 14.0 SILTY SAND
Classification MC%
CO
N
S
O
L
S
T
R
A
I
N
S
I
N
G
L
E
-
G
I
N
T
S
T
D
U
S
L
A
B
.
G
D
T
-
8
/
2
5
/
2
5
1
3
:
3
3
-
Y
:
\
G
I
N
T
B
A
C
K
U
P
S
\
M
A
I
N
T
R
A
N
S
F
E
R
1
0
.
2
8
\
P
R
O
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S
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2
0
2
5
\
2
5
.
2
2
.
1
1
6
P
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T
O
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T
A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.1 1 10 100
CO
N
S
O
L
I
D
A
T
I
O
N
(
-
)
%
S
W
E
L
L
(
+
)
APPLIED PRESSURE, ksf
SWELL/CONSOLIDATION TEST
125 10
Date: 8/7/25Date: 8/7/25Note: Water Added to Sample at 200 psf.
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
BOREHOLE DEPTH
10 2.0 FILL-CLAYEY SAND
Classification MC%
CO
N
S
O
L
S
T
R
A
I
N
S
I
N
G
L
E
-
G
I
N
T
S
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D
U
S
L
A
B
.
G
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-
8
/
2
5
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2
5
1
3
:
3
3
-
Y
:
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B
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F
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1
0
.
2
8
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6
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A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.1 1 10 100
CO
N
S
O
L
I
D
A
T
I
O
N
(
-
)
%
S
W
E
L
L
(
+
)
APPLIED PRESSURE, ksf
SWELL/CONSOLIDATION TEST
117 15
Date: 8/7/25Date: 8/7/25Note: Water Added to Sample at 200 psf.
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
BOREHOLE DEPTH
11 2.0 FILL-SANDY LEAN CLAY
Classification MC%
CO
N
S
O
L
S
T
R
A
I
N
S
I
N
G
L
E
-
G
I
N
T
S
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S
L
A
B
.
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-
8
/
2
5
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2
5
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3
3
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Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.0010.010.1110100
PI Cc
18
11
13
14
12
29
19
29
23
20
CuLL PL
11
8
16
9
8
GRAIN SIZE DISTRIBUTION
COBBLES GRAVEL
29.0
27.3
31.6
32.5
35.8
SAND
GRAIN SIZE IN MILLIMETERS
coarse fine
Classification
D100 D60 D30 D10 %Gravel
0.611
0.732
0.828
0.278
1
1
2
3
3
coarse SILT OR CLAYfinemedium
4.0
9.0
4.0
4.0
14.0
%Sand %Silt %Clay
0.082
0.103
4.4
8.1
16.5
2.0
66.6
64.6
51.9
65.4
BOREHOLE DEPTH
BOREHOLE DEPTH
3 100
1
1
2
3
3
24 16 30
1 2006 10 501/2
HYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
1403420 406 601.5 8 143/4 3/8
4.0
9.0
4.0
4.0
14.0
PE
R
C
E
N
T
F
I
N
E
R
B
Y
W
E
I
G
H
T
CLAYEY SAND(SC)
CLAYEY SAND(SC)
CLAYEY SAND with GRAVEL(SC)
CLAYEY SAND(SC)
CLAYEY SAND(SC)
9.5
9.5
9.5
9.5
0.075
CLIENT Jarred Black
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GR
A
I
N
S
I
Z
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-
G
I
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S
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A
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A
.
G
P
J
Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.0010.010.1110100
PI Cc
13
15
16
15
17
40
34
49
24
43
CuLL PL
27
19
33
9
26
GRAIN SIZE DISTRIBUTION
COBBLES GRAVEL
66.1
41.2
72.4
46.5
85.9
SAND
GRAIN SIZE IN MILLIMETERS
coarse fine
Classification
D100 D60 D30 D10 %Gravel
4
6
6
6
6
coarse SILT OR CLAYfinemedium
19.0
2.0
4.0
9.0
14.0
%Sand %Silt %Clay
BOREHOLE DEPTH
BOREHOLE DEPTH
3 100
4
6
6
6
6
24 16 30
1 2006 10 501/2
HYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
1403420 406 601.5 8 143/4 3/8
19.0
2.0
4.0
9.0
14.0
PE
R
C
E
N
T
F
I
N
E
R
B
Y
W
E
I
G
H
T
SANDY LEAN CLAY(CL)
CLAYEY SAND(SC)
LEAN CLAY with SAND(CL)
CLAYEY SAND(SC)
LEAN CLAY(CL)
0.075
0.075
0.075
0.075
0.075
CLIENT Jarred Black
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GR
A
I
N
S
I
Z
E
-
G
I
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T
S
T
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S
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A
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2
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1
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G
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Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.0010.010.1110100
PI Cc
15
NP
14
16
14
27
NP
27
22
26
CuLL PL
12
NP
13
6
12
GRAIN SIZE DISTRIBUTION
COBBLES GRAVEL
34.3
15.5
40.1
43.5
43.5
SAND
GRAIN SIZE IN MILLIMETERS
coarse fine
Classification
D100 D60 D30 D10 %Gravel
0.298
0.811
7
7
8
9
10
coarse SILT OR CLAYfinemedium
4.0
9.0
2.0
2.0
2.0
%Sand %Silt %Clay
0.317
2.7
9.8
63.0
74.7
BOREHOLE DEPTH
BOREHOLE DEPTH
3 100
7
7
8
9
10
24 16 30
1 2006 10 501/2
HYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
1403420 406 601.5 8 143/4 3/8
4.0
9.0
2.0
2.0
2.0
PE
R
C
E
N
T
F
I
N
E
R
B
Y
W
E
I
G
H
T
CLAYEY SAND(SC)
SILTY SAND(SM)
CLAYEY SAND(SC)
SILTY, CLAYEY SAND(SC-SM)
CLAYEY SAND(SC)
9.5
9.5
0.075
0.075
0.075
CLIENT Jarred Black
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GR
A
I
N
S
I
Z
E
-
G
I
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T
S
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A
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Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.0010.010.1110100
PI Cc
1631
CuLL PL
15
GRAIN SIZE DISTRIBUTION
COBBLES GRAVEL
63.9
SAND
GRAIN SIZE IN MILLIMETERS
coarse fine
Classification
D100 D60 D30 D10 %Gravel
11
coarse SILT OR CLAYfinemedium
2.0
%Sand %Silt %Clay
BOREHOLE DEPTH
BOREHOLE DEPTH
3 100
11
24 16 30
1 2006 10 501/2
HYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
1403420 406 601.5 8 143/4 3/8
2.0
PE
R
C
E
N
T
F
I
N
E
R
B
Y
W
E
I
G
H
T
SANDY LEAN CLAY(CL)
0.075
CLIENT Jarred Black
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
GR
A
I
N
S
I
Z
E
-
G
I
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S
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Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
1 4 FILL-CLAYEY SAND 8.8 120.4 29 29 18 11
1 9 CLAYEY SAND(SC)4.2 133.0 27 19 11 8
1 14 CLAYEY SAND 5.2 121.2
1 19 LEAN CLAY with SAND 22.9 108.7
1 24 INTERBEDDED CLAYSTONE/SANDSTONE BEDROCK 17.9 113.7
2 4 FILL-CLAYEY SAND with GRAVEL 7.8 127.6 0 32 29 13 16
2 9 CLAYEY SAND 2.9 122.6 -0.3/1000
2 14 CLAYEY SAND 8.3
2 19 INTERBEDDED CLAYSTONE/SANDSTONE BEDROCK 14.6 115.8
2 24 INTERBEDDED CLAYSTONE/SANDSTONE BEDROCK 18.0 107.6
3 4 FILL-CLAYEY SAND 8.0 132.7 33 23 14 9
3 9 CLAYEY SAND 4.3 138.4
3 14 CLAYEY SAND(SC)3.5 141.9 36 20 12 8
3 24 INTERBEDDED CLAYSTONE/SANDSTONE BEDROCK 8.9 136.5
3 29 INTERBEDDED CLAYSTONE/SANDSTONE BEDROCK 20.0
3 34 INTERBEDDED CLAYSTONE/SANDSTONE BEDROCK 15.1
4 4 FILL-CLAYEY SAND 8.9 120.7 +0.2/500
4 9 CLAYEY SAND 3.2 126.5 -0.1/500
4 14 SANDY LEAN CLAY 17.6 109.4 -0.8/1000
4 19 SANDY LEAN CLAY(CL)26.8 100.3 66 40 13 27
4 24 SANDY LEAN CLAY 22.9 107.6
5 2 FILL-CLAYEY SAND to SANDY LEAN CLAY 18.9 106.9 +0.4/200
5 4 FILL-CLAYEY SAND to SANDY LEAN CLAY 11.1 114.7 -0.1/500
5 9 CLAYEY to SILTY SAND 2.9
5 14 CLAYEY to SILTY SAND 14.2 116.8
6 2 FILL-CLAYEY SAND 15.4 109.4 41 34 15 19
6 4 FILL-LEAN CLAY with SAND 19.5 106.3 +0.7/500 0 72 49 16 33
6 9 CLAYEY SAND(SC)9.4 125.4 47 24 15 9
6 14 LEAN CLAY(CL)29.8 94.8 86 43 17 26
7 2 FILL-CLAYEY SAND 8.2 122.2 0
Water
Content
(%)
PAGE 1 OF 2
Liquid
Limit
Atterberg LimitsDry
Density
(pcf)
Passing
#200 Sieve
(%)
Water Soluble
Sulfates
(ppm)
SUMMARY OF LABORATORY RESULTS
Soil Description Plastic
Limit
Plasticity
Index
Borehole Depth
Swell (+) or
Consolidation (-)/
Surcharge
(%/psf)
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
LA
B
S
U
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M
A
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Y
-
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I
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S
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D
U
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A
B
.
G
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-
8
/
2
5
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2
5
1
3
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3
2
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B
A
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S
F
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1
0
.
2
8
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2
0
2
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2
2
.
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Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
7 4 FILL-CLAYEY SAND 11.2 120.3 34 27 15 12
7 9 SILTY SAND(SM)4.9 15 NP NP NP
7 14 SILTY SAND 7.5 127.3 -0.4/1000
8 2 FILL-CLAYEY SAND 11.7 125.2 40 27 14 13
8 4 CLAYEY SAND 5.1
9 2 FILL-SILTY, CLAYEY SAND 10.0 127.1 43 22 16 6
9 4 CLAYEY to SILTY SAND 13.2 119.8
10 2 FILL-CLAYEY SAND 9.6 124.8 +0.4/200 0 44 26 14 12
10 4 CLAYEY SAND 8.3 123.6
11 2 FILL-SANDY LEAN CLAY 14.7 116.8 +1.1/200 64 31 16 15
11 4 SANDY LEAN CLAY 9.2 125.9
Water
Content
(%)
PAGE 2 OF 2
Liquid
Limit
Atterberg LimitsDry
Density
(pcf)
Passing
#200 Sieve
(%)
Water Soluble
Sulfates
(ppm)
SUMMARY OF LABORATORY RESULTS
Soil Description Plastic
Limit
Plasticity
Index
Borehole Depth
Swell (+) or
Consolidation (-)/
Surcharge
(%/psf)
CLIENT Pederson Toyota
PROJECT NUMBER 25.22.116
PROJECT NAME Pedersen Toyota Dealership Expansion
PROJECT LOCATION Fort Collins, CO
LA
B
S
U
M
M
A
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Y
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Cole Garner Geotechnical1070 W 124th Ave, Suite 300Westminster, CO 80234
APPENDIX C
GENERAL NOTES
GENERAL NOTES
DRILLING & SAMPLING SYMBOLS:
SS: Split Spoon - 1!" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger
ST: Thin-Walled Tube – 2.5" O.D., unless otherwise noted PA: Power Auger
RS: Ring Sampler - 2.42" I.D., 3" O.D., unless otherwise noted HA: Hand Auger
CB: California Barrel - 1.92" I.D., 2.5" O.D., unless otherwise noted RB: Rock Bit
BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary
The number of blows required to advance a standard 2-inch O.D. split-spoon sampler (SS) the last 12 inches of the total 18-inch
penetration with a 140-pound hammer falling 30 inches is considered the “Standard Penetration” or “N-value”. For 2.5” O.D.
California Barrel samplers (CB) the penetration value is reported as the number of blows required to advance the sampler 12
inches using a 140-pound hammer falling 30 inches, reported as “blows per inch,” and is not considered equivalent to the
“Standard Penetration” or “N-value”.
WATER LEVEL MEASUREMENT SYMBOLS:
WL: Water Level WS: While Sampling
WCI: Wet Cave in WD: While Drilling
DCI: Dry Cave in BCR: Before Casing Removal
AB: After Boring ACR: After Casing Removal
Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other
times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater.
In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-term observations.
DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils
have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand.
Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they
are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents
may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined
on the basis of their in-place relative density and fine-grained soils on the basis of their consistency.
FINE-GRAINED SOILS COARSE-GRAINED SOILS BEDROCK
(CB)
Blows/Ft.
(SS)
Blows/Ft.
Consistency
(CB)
Blows/Ft.
(SS)
Blows/Ft.
Relative
Density
(CB)
Blows/Ft.
(SS)
Blows/Ft.
Consistency
< 3 0-2 Very Soft 0-5 < 3 Very Loose < 24 < 20 Weathered
3-5 3-4 Soft 6-14 4-9 Loose 24-35 20-29 Firm
6-10 5-8 Medium Stiff 15-46 10-29 Medium Dense 36-60 30-49 Medium Hard
11-18 9-15 Stiff 47-79 30-50 Dense 61-96 50-79 Hard
19-36 16-30 Very Stiff > 79 > 50 Very Dense > 96 > 79 Very Hard
> 36 > 30 Hard
RELATIVE PROPORTIONS OF SAND AND
GRAVEL
GRAIN SIZE TERMINOLOGY
Descriptive Terms of
Other Constituents
Percent of
Dry Weight
Major Component
of Sample
Particle Size
Trace < 15 Boulders Over 12 in. (300mm)
With 15 – 29 Cobbles 12 in. to 3 in. (300mm to 75 mm)
Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75 mm)
Sand
Silt or Clay
#4 to #200 sieve (4.75mm to 0.075mm)
Passing #200 Sieve (0.075mm)
RELATIVE PROPORTIONS OF FINES PLASTICITY DESCRIPTION
Descriptive Terms of
Other Constituents
Percent of
Dry Weight
Term Plasticity Index
Trace
With
Modifiers
< 5
5 – 12
> 12
Non-plastic
Low
Medium
High
0
1-10
11-30
30+
UNIFIED SOIL CLASSIFICATION SYSTEM
Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Soil Classification
Group
Symbol
Group NameB
Cu ! 4 and 1 " Cc " 3E GW Well graded gravelF Clean Gravels
Less than 5% finesC Cu < 4 and/or 1 > Cc > 3E GP Poorly graded gravelF
Fines classify as ML or MH GM Silty gravelF,G, H
Coarse Grained Soils
More than 50% retained
on No. 200 sieve
Gravels
More than 50% of coarse
fraction retained on
No. 4 sieve Gravels with Fines More
than 12% finesC Fines classify as CL or CH GC Clayey gravelF,G,H
Cu ! 6 and 1 " Cc " 3E SW Well graded sandI Clean Sands
Less than 5% finesD Cu < 6 and/or 1 > Cc > 3E SP Poorly graded sandI
Fines classify as ML or MH SM Silty sandG,H,I
Sands
50% or more of coarse
fraction passes
No. 4 sieve Sands with Fines
More than 12% finesD Fines classify as CL or CH SC Clayey sandG,H,I
PI > 7 and plots on or above “A” lineJ CL Lean clayK,L,M Silts and Clays
Liquid limit less than 50
Inorganic
PI < 4 or plots below “A” lineJ ML SiltK,L,M
Liquid limit - oven
dried
Organic clayK,L,M,N
Fine-Grained Soils
50% or more passes the
No. 200 sieve
Organic
Liquid limit - not
dried
< 0.75 OL
Organic siltK,L,M,O
Inorganic PI plots on or above “A” line CH Fat clayK,L,M
Silts and Clays
Liquid limit 50 or more PI plots below “A” line MH Elastic siltK,L,M
Liquid limit - oven dried Organic clayK,L,M,P Organic
Liquid limit - not dried
< 0.75 OH
Organic siltK,L,M,Q
Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat
A Based on the material passing the 3-in. (75-mm) sieve
B If field sample contained cobbles or boulders, or both, add “with cobbles
or boulders, or both” to group name.
C Gravels with 5 to 12% fines require dual symbols: GW-GM well graded
gravel with silt, GW-GC well graded gravel with clay, GP-GM poorly
graded gravel with silt, GP-GC poorly graded gravel with clay.
D Sands with 5 to 12% fines require dual symbols: SW-SM well graded
sand with silt, SW-SC well graded sand with clay, SP-SM poorly graded
sand with silt, SP-SC poorly graded sand with clay
E Cu = D60/D10 Cc =
F If soil contains ! 15% sand, add “with sand” to group name.
G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.
HIf fines are organic, add “with organic fines” to group name.
I If soil contains ! 15% gravel, add “with gravel” to group name.
J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.
K If soil contains 15 to 29% plus No. 200, add “with sand” or “with
gravel,” whichever is predominant.
L If soil contains ! 30% plus No. 200 predominantly sand, add
“sandy” to group name.
M If soil contains ! 30% plus No. 200, predominantly gravel, add
“gravelly” to group name.
N PI ! 4 and plots on or above “A” line.
O PI < 4 or plots below “A” line.
P PI plots on or above “A” line.
Q PI plots below “A” line.
ROCK CLASSIFICATION
(Based on ASTM C-294)
Sedimentary Rocks
Sedimentary rocks are stratified materials laid down by water or wind. The sediments may be
composed of particles or pre-existing rocks derived by mechanical weathering, evaporation or by
chemical or organic origin. The sediments are usually indurated by cementation or compaction.
Chert Very fine-grained siliceous rock composed of micro-crystalline or cyrptocrystalline
quartz, chalcedony or opal. Chert is various colored, porous to dense, hard and
has a conchoidal to splintery fracture.
Claystone Fine-grained rock composed of or derived by erosion of silts and clays or any rock
containing clay. Soft massive and may contain carbonate minerals.
Conglomerate Rock consisting of a considerable amount of rounded gravel, sand and cobbles
with or without interstitial or cementing material. The cementing or interstitial
material may be quartz, opal, calcite, dolomite, clay, iron oxides or other
materials.
Dolomite A fine-grained carbonate rock consisting of the mineral dolomite [CaMg(CO3)2].
May contain noncarbonate impurities such as quartz, chert, clay minerals, organic
matter, gypsum and sulfides. Reacts with hydrochloric acid (HCL).
Limestone A fine-grained carbonate rock consisting of the mineral calcite (CaCO3). May
contain noncarbonate impurities such as quartz, chert, clay minerals, organic
matter, gypsum and sulfides. Reacts with hydrochloric acid (HCL).
Sandstone Rock consisting of particles of sand with or without interstitial and cementing
materials. The cementing or interstitial material may be quartz, opal, calcite,
dolomite, clay, iron oxides or other material.
Shale Fine-grained rock composed of or derived by erosion of silts and clays or any rock
containing clay. Shale is hard, platy, of fissile may be gray, black, reddish or
green and may contain some carbonate minerals (calcareous shale).
Siltstone Fine grained rock composed of or derived by erosion of silts or rock containing
silt. Siltstones consist predominantly of silt sized particles (0.0625 to 0.002 mm in
diameter) and are intermediate rocks between claystones and sandstones and
may contain carbonate minerals.
LABORATORY TEST
SIGNIFICANCE AND PURPOSE
TEST SIGNIFICANCE PURPOSE
California Bearing
Ratio
Used to evaluate the potential strength of subgrade soil,
subbase, and base course material, including recycled
materials for use in road and airfield pavements.
Pavement Thickness
Design
Consolidation Used to develop an estimate of both the rate and amount of
both differential and total settlement of a structure.
Foundation Design
Direct Shear Used to determine the consolidated drained shear strength
of soil or rock.
Bearing Capacity,
Foundation Design,
and Slope Stability
Dry Density Used to determine the in-place density of natural, inorganic,
fine-grained soils.
Index Property Soil
Behavior
Expansion Used to measure the expansive potential of fine-grained
soil and to provide a basis for swell potential classification.
Foundation and Slab
Design
Gradation Used for the quantitative determination of the distribution of
particle sizes in soil.
Soil Classification
Liquid & Plastic Limit,
Plasticity Index
Used as an integral part of engineering classification
systems to characterize the fine-grained fraction of soils,
and to specify the fine-grained fraction of construction
materials.
Soil Classification
Permeability Used to determine the capacity of soil or rock to conduct a
liquid or gas.
Groundwater Flow
Analysis
pH Used to determine the degree of acidity or alkalinity of a
soil.
Corrosion Potential
Resistivity Used to indicate the relative ability of a soil medium to carry
electrical currents.
Corrosion Potential
R-Value Used to evaluate the potential strength of subgrade soil,
subbase, and base course material, including recycled
materials for use in road and airfield pavements.
Pavement Thickness
Design
Soluble Sulfate Used to determine the quantitative amount of soluble
sulfates within a soil mass.
Corrosion Potential
Unconfined
Compression
To obtain the approximate compressive strength of soils
that possess sufficient cohesion to permit testing in the
unconfined state.
Bearing Capacity
Analysis for
Foundations
Water Content Used to determine the quantitative amount of water in a soil
mass.
Index Property Soil
Behavior
REPORT TERMINOLOGY
(Based on ASTM D653)
Allowable Soil
Bearing Capacity
The recommended maximum contact stress developed at the interface of the foundation
element and the supporting material.
Alluvium Soil, the constituents of which have been transported in suspension by flowing water and
subsequently deposited by sedimentation.
Aggregate Base
Course
A layer of specified material placed on a subgrade or subbase usually beneath slabs or
pavements.
Backfill A specified material placed and compacted in a confined area.
Bedrock A natural aggregate of mineral grains connected by strong and permanent cohesive forces.
Usually requires drilling, wedging, blasting or other methods of extraordinary force for
excavation.
Bench A horizontal surface in a sloped deposit.
Caisson (Drilled
Pier or Shaft)
A concrete foundation element cast in a circular excavation which may have an enlarged
base. Sometimes referred to as a cast-in-place pier or drilled shaft.
Coefficient of
Friction
A constant proportionality factor relating normal stress and the corresponding shear stress
at which sliding starts between the two surfaces.
Colluvium Soil, the constituents of which have been deposited chiefly by gravity such as at the foot of a
slope or cliff.
Compaction The densification of a soil by means of mechanical manipulation
Concrete Slab-on-
Grade
A concrete surface layer cast directly upon a base, subbase or subgrade, and typically used
as a floor system.
Differential
Movement
Unequal settlement or heave between, or within foundation elements of structure.
Earth Pressure The pressure exerted by soil on any boundary such as a foundation wall.
ESAL Equivalent Single Axle Load, a criteria used to convert traffic to a uniform standard, (18,000
pound axle loads).
Engineered Fill Specified material placed and compacted to specified density and/or moisture conditions
under observations of a representative of a geotechnical engineer.
Equivalent Fluid A hypothetical fluid having a unit weight such that it will produce a pressure against a lateral
support presumed to be equivalent to that produced by the actual soil. This simplified
approach is valid only when deformation conditions are such that the pressure increases
linearly with depth and the wall friction is neglected.
Existing Fill (or
Man-Made Fill)
Materials deposited throughout the action of man prior to exploration of the site.
Existing Grade The ground surface at the time of field exploration.
REPORT TERMINOLOGY
(Based on ASTM D653)
Expansive
Potential
The potential of a soil to expand (increase in volume) due to absorption of moisture.
Finished Grade The final grade created as a part of the project.
Footing A portion of the foundation of a structure that transmits loads directly to the soil.
Foundation The lower part of a structure that transmits the loads to the soil or bedrock.
Frost Depth The depth at which the ground becomes frozen during the winter season.
Grade Beam A foundation element or wall, typically constructed of reinforced concrete, used to span
between other foundation elements such as drilled piers.
Groundwater Subsurface water found in the zone of saturation of soils or within fractures in bedrock.
Heave Upward movement.
Lithologic The characteristics which describe the composition and texture of soil and rock by
observation.
Native Grade The naturally occurring ground surface.
Native Soil Naturally occurring on-site soil, sometimes referred to as natural soil.
Optimum Moisture
Content
The water content at which a soil can be compacted to a maximum dry unit weight by a
given compactive effort.
Perched Water Groundwater, usually of limited area maintained above a normal water elevation by the
presence of an intervening relatively impervious continuous stratum.
Scarify To mechanically loosen soil or break down existing soil structure.
Settlement Downward movement.
Skin Friction (Side
Shear)
The frictional resistance developed between soil and an element of the structure such as a
drilled pier.
Soil (Earth) Sediments or other unconsolidated accumulations of solid particles produced by the
physical and chemical disintegration of rocks, and which may or may not contain organic
matter.
Strain The change in length per unit of length in a given direction.
Stress The force per unit area acting within a soil mass.
Strip To remove from present location.
Subbase A layer of specified material in a pavement system between the subgrade and base course.
Subgrade The soil prepared and compacted to support a structure, slab or pavement system.