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GEOTECHNICAL REPORT
421 West Main Street Development Table of Contents
Bozeman, Montana i
Table of Contents
1.0 EXECUTIVE SUMMARY .................................................................................................... 1
2.0 INTRODUCTION .................................................................................................................. 2
2.1 Purpose and Scope ....................................................................................................... 2
2.2 Project Description ........................................................................................................ 2
3.0 SITE CONDITIONS .............................................................................................................. 3
3.1 Geology and Physiography .......................................................................................... 3
3.2 Surface Conditions ........................................................................................................ 3
3.3 Subsurface Conditions .................................................................................................. 4
3.3.1 Soils .......................................................................................................................... 4
3.3.2 Ground Water ......................................................................................................... 5
4.0 ENGINEERING ANALYSIS ............................................................................................... 6
4.1 Introduction ..................................................................................................................... 6
4.2 Site Grading and Excavations ..................................................................................... 6
4.3 Convention Shallow Foundations with EAP System (Recommended) ................. 6
4.4 Foundation Walls ........................................................................................................... 7
4.5 Floor Slabs and Exterior Flatwork ............................................................................... 8
4.6 Pavements ...................................................................................................................... 9
5.0 RECOMMENDATIONS ..................................................................................................... 10
5.1 Site Grading and Excavations ................................................................................... 10
5.2 Conventional Shallow Foundations with EAP System (Recommended)............ 11
5.3 Foundation Walls ......................................................................................................... 12
5.4 Floor Slabs and Exterior Flatwork ............................................................................. 13
5.5 Pavements .................................................................................................................... 14
5.6 Continuing Services .................................................................................................... 16
6.0 SUMMARY OF FIELD AND LABORATORY STUDIES .............................................. 17
6.1 Field Explorations ........................................................................................................ 17
6.2 Laboratory Testing ...................................................................................................... 17
7.0 LIMITATIONS ..................................................................................................................... 19
421 West Main Street Development Appendix
Bozeman, Montana ii
APPENDIX
Boring & Test Pit Location Map (Figure 1)
Logs of Exploratory Borings (Figures 2 through 5)
Log of Exploratory Test Pit (Figure 6)
Laboratory Test Data (Figures 7 through 17)
Construction Standard No. 02801-06C
LTTPBind Online PG Asphalt Binder Analysis Summary
Soil Classification and Sampling Terminology for Engineering Purposes
Classification of Soils for Engineering Purposes
421 West Main Street Development Executive Summary
Bozeman, Montana Page 1
GEOTECHNICAL REPORT
421 WEST MAIN STREET DEVELOPMENT
BOZEMAN, MONTANA
1.0 EXECUTIVE SUMMARY
The geotechnical investigation for the 421 West Main Street Development project, generally
encountered compressible native lean clay over clayey gravel with sand. The lean clay extended to
depths of 15.0 to 17.0 feet in the borings performed. The lean clay encountered was weak,
compressible, and not considered suitable for support of the structural loads anticipated for this
project. The primary geotechnical concern on this project is the presence of weak and compressible
lean clay at the anticipated footing elevations and the risk of resulting foundation settlement.
Significant subgrade improvements will be necessary to control the overall settlement in the
clay. The seismic site class for the area is D, and the risk of seismically-induced liquefaction or
soil settlement is considered low and does not warrant additional evaluation.
Based on our understanding of the project and the concerns discussed above, it is our opinion that
all new building foundations and slab systems will require subsurface improvements comprised of:
• Specialized Engineered Aggregate Pier (EAP) systems to improve to fill soils and facilitate
standard foundation construction over the native clay.
• An increased layer of granular fill directly beneath the interior building slabs to provide a
structural cushion, a capillary-break from the subgrade, and a drainage medium.
We have also included recommendations for exterior concrete flatwork and asphalt pavement
systems, if applicable, for your consideration. In most cases, it is not practical or cost effective to
completely remove or improve poor soils, such as the lean clay encountered, beneath exterior site
development features. Also, these features are generally able to tolerate a higher level of potential
movement without experiencing detrimental impact to their function on the site. However, if the
project is unable or unwilling to accept any risk of potential vertical movements or distress to such
exterior features, the use of similar improvement methods, as discussed above, should be
incorporated throughout the project site.
421 West Main Street Development Introduction
Bozeman, Montana Page 2
2.0 INTRODUCTION
2.1 Purpose and Scope
This report presents the results of our geotechnical study for the 421 West Main Street
Development located in Bozeman, Montana. The purpose of the geotechnical study is to determine
the general surface and subsurface conditions at the proposed site and to develop geotechnical
engineering recommendations for support of the proposed structure and design of related facilities.
This report describes the field work and laboratory analyses conducted for this project, the surface
and subsurface conditions encountered, and presents our recommendations for the proposed
foundations and related site development.
Our field work included drilling four soil borings and excavating one test pit across the proposed
site. Samples were obtained from the borings and test pit and returned to our Great Falls laboratory
for testing. Laboratory testing was performed on selected soil samples to determine engineering
properties of the subsurface materials. The information obtained during our field investigations and
laboratory analyses was used to develop recommendations for the design of the proposed
foundation systems.
2.2 Project Description
It is our understanding that the proposed project consists of one new building that will encompass
the entire project site. The structure is proposed to be six stories in height with below grade parking.
A podium style building is anticipated with upper level stick frame construction. Structural loads had
not been developed at the time of this report. However, for the purpose of our analysis, we have
assumed that wall loads will be less than 6,000 pounds per lineal foot and column loads will be less
than 400 kips.
Site development will most likely include limited landscaping, exterior concrete flatwork, and
Portland cement concrete pavement for indoor parking. If the assumed design values presented
above vary from the actual project parameters, the recommendations presented in this report
should be reevaluated.
421 West Main Street Development Site Conditions
Bozeman, Montana Page 3
3.0 SITE CONDITIONS
3.1 Geology and Physiography
The site is geologically characterized as alluvium (Qal). These deposits are generally valley fill
comprised of mixtures of gravel, sand, and silt; however, some terrace deposits and glacial drift are
present in areas, and the glacial drift is generally of clay composition. The alluvial formations are
typical of areas proximate to stream and river channels and floodplains. Areas near the site also
encounter upper tertiary sediments or sedimentary rock (Tsu). This formation includes
conglomerate, tuffaceous sandstone and siltstone, marlstone, and equivalent sediment and ash
beds.
Geologic Map of Montana, Edition 1.0 (2007)
Montana Bureau of Mines & Geology
Based on the subsurface conditions encountered, the site falls under seismic Site Class D. The
structural engineer should utilize the site classification above to determine the appropriate seismic
design data for use on this project in accordance with current applicable building codes. The
likelihood of seismically-induced soil liquefaction or settlement for this project is low and does not
warrant additional evaluation.
3.2 Surface Conditions
The proposed project site is located directly northeast of the intersection between West Main Street
and North 5th Avenue in Bozeman, Montana, and presently consists of two commercial buildings
proposed for demolition. Based on background information and site observations, the site slopes
downward toward the northeast at slopes ranging from 0.5 to 1.5 percent. The topography is best
421 West Main Street Development Site Conditions
Bozeman, Montana Page 4
described as flat to gently sloped. Outside of the existing building footprints, the site is covered by
an asphalt parking lot that was constructed over a concrete slab varying in thickness.
3.3 Subsurface Conditions
3.3.1 Soils
The subsurface soil conditions appear to be relatively consistent based on our exploratory
drilling, excavating, and soil sampling. In general, the subsurface soil conditions
encountered consist of asphalt/concrete with base course fill materials over lean clay
extending to depths ranging from 15.0 to 17.0 feet. All borings encountered clayey gravel
with sand at depths ranging between 15.0 and 17.0 feet and extending to depths of at least
30.5 feet, the maximum depth investigated.
The subsurface soils are described in detail on the enclosed boring and test pit logs and are
summarized below. The stratification lines shown on the logs represent approximate
boundaries between soil types and the actual in situ transition may be gradual vertically or
discontinuous laterally.
PARKING LOT SECTION
The borings and test pit were completed in existing parking areas. The existing parking
section consisted of 1.0 to 3.0 inches of asphalt, 5.0 to 7.0 inches of concrete, and a gravel
base with broken concrete pieces mixed throughout. The overall pavement section varied
between 2.5 and 4.0 feet. A lift of remnant topsoil was encountered and noted in Boring B-4
and Test Pit TP-1 and was included in the parking lot fill thickness.
LEAN CLAY
Lean clay was observed in all borings and the test pit. The lean clay is considered very soft
to firm as indicated by penetration resistance values which ranged from 1 to 8 blows per foot
(bpf) and averaged 5 bpf. Four samples of the material contained between 0 and 4 percent
gravel, between 4 and 21 percent sand, and between 76 and 96 percent fines (silt and clay).
Four samples exhibited liquid limits ranging from 36 to 45 percent and plasticity indices
ranging from 17 to 27 percent. The natural moisture contents varied from 18 to 31 percent
and averaged 23 percent.
One composite sample of the lean clay was collected and tested to evaluate its compactive
properties. The results of these tests are summarized below.
Maximum Dry
Density (pcf)
Optimum Moisture
Content (%)
106.1 17.6
421 West Main Street Development Site Conditions
Bozeman, Montana Page 5
CLAYEY GRAVEL WITH SAND
Clayey gravel with sand was encountered in all borings at depths below 15.0 to 17.0 feet
below the ground surface. The gravel is considered very dense as indicated by penetration
resistance values exceeding 50 bpf. Two samples of the material contained between 41 and
46 percent gravel, between 35 and 40 percent sand, and between 14 and 24 percent fines
(silt and clay). Sampling coarse gravels during drilling generally results in samples which do
not accurately represent the material present on site due to material degradation and
segregation during drilling. The actual materials are anticipated to contain large cobbles with
sizes estimated to be up to 6-inch based on drilling observations and our experience in the
area. The natural moisture contents varied from 2 to 15 percent and averaged 7 percent.
3.3.2 Ground Water
Ground water was encountered in borings B-1 and B-4 at a depth of approximately 27 feet
below the ground surface. Water levels were measured at the time of drilling and
excavation. The presence or absence of observed ground water may be directly related to
the time of the subsurface investigation. Numerous factors contribute to seasonal ground
water occurrences and fluctuations, and the evaluation of such factors is beyond the scope
of this report.
421 West Main Street Development Engineering Analysis
Bozeman, Montana Page 6
4.0 ENGINEERING ANALYSIS
4.1 Introduction
The primary geotechnical concern regarding the proposed site is the thickness of weak and
compressible clay soil encountered to depths of 15.0 to 17.0 feet. Based on the planned size of the
building and the anticipated foundation loads associated with similar multi-story construction,
settlements are a significant concern for this project. Conventional foundation systems are
anticipated to require significant subgrade improvement to control potential settlements and provide
reasonable design bearing pressures. Deep foundation systems could be considered for the
support of the buildings; however, they are generally less cost effective than the recommended EAP
improvement system. If consideration of a deep foundation is desired, analysis and
recommendations can be provided through an addendum to this report.
4.2 Site Grading and Excavations
The ground surface at the proposed site is fully developed with buildings and parking areas. The
site slopes downward toward the northeast at grades of up to 1.5 percent. Based on our field work,
limited pavement, base course, and building materials over native lean clay are anticipated in
excavations. The actual materials encountered will depend on the location on site and depth of
each excavation. Ground water was encountered below the anticipated depths of footing and utility
excavations; however, depending on the time of year, occasional pockets of trapped or perched
ground water associated with recent precipitation events should be anticipated. Ground water was
observed at depths of 27 feet below existing site grades but may fluctuate seasonally and potential
seasonal fluctuations have not been evaluated for this site.
4.3 Convention Shallow Foundations with EAP System (Recommended)
The existing lean clay encountered across the site is not suitable to support foundation loads due to
its low strength, compressibility, and the associated risk of settlement and bearing failure. Complete
removal of these soils would require up to seven feet of removal and replacement with engineered
fill. Based on the tight project area and our experience, this magnitude of removal is likely cost-
prohibitive. An alternative to the complete removal and replacement of the surficial clay soils
includes using an engineered aggregate pier system (EAP), also known as a rammed aggregate
pier (RAP) system. This system is specialized and proprietary; thus, design would be performed by
specialized firms such as Specialty Foundation Systems, (Billings, Montana), GTFC – West
(Hillsboro, Oregon), or Montana Helical Pier (Whitefish, Montana). This subgrade improvement
system is commonly used throughout Bozeman.
EAPs are installed by drilling a hole of a specified depth and diameter and constructing rock
columns comprised of very dense, highly compacted aggregate. Ramming of thin lifts takes place
with a high-energy beveled tamper that densifies the aggregate and forces it laterally into the
sidewalls of the hole. This action increases the lateral stress in the surrounding soil, thereby
421 West Main Street Development Engineering Analysis
Bozeman, Montana Page 7
providing a stabilized composite soil mass. The result of the EAP installation is a significant
strengthening and stiffening of the subsurface soils that would then support conventional footings.
This allows for improved performance of the lean clay soils without requiring it to be completely
removed thus reducing the overall cost of the project. EAPs can be installed in a variety of ground
water conditions using varying methods and may or may not warrant some level of site dewatering
during construction. This should be discussed with the EAP designer / installer based on their
available equipment and abilities.
Based on our experience with the EAP system in similar conditions, we anticipate EAP elements to
utilize 24-inch to 30-inch diameter piers and lengths sufficient to tie the aggregate columns into the
underlying native gravel to provide adequate subgrade improvement for support of typical
foundation loads. EAPs constructed in this manner generally allow for a design bearing pressure of
at least 4,000 psf. Footings supported on EAP improved soils are generally designed to limit
potential settlements to less than one inch with differential settlements being less than ¾-inch;
however, stricter design criteria could be utilized and would likely result in more EAP elements.
On EAP projects, the EAP designer typically works closely with the design team, and they create
their own EAP installation plans to be included as part of the overall package. They then provide the
specialized construction and quality control during the installation of this system. Their design is
prepared utilizing the data provided in this report and structural loads provided by the project
structural engineer. We anticipate this approach to be more economical and provide for a shorter
construction schedule than the complete removal and replacement of the lean clay beneath the
structures.
Other deep foundation options are available, and analysis of those options can be completed
through addendums to this report, if desired. For example, helical piers, driven piles, and cast-in-
place drilled piers may be suitable options; however, generally less economical that EAPs.
The lateral resistance of spread footings is controlled by a combination of sliding resistance
between the footing and the foundation material at the base of the footing and the passive earth
pressure against the side of the footing in the direction of movement. Design parameters are given
in the recommendations section of this report.
4.4 Foundation Walls
Foundation walls will be subjected to horizontal loading due to lateral earth pressures. The lateral
earth pressures are a function of the natural and backfill soil types and acceptable wall movements,
which affect soil strain to mobilize the shear strength of the soil. More soil movement is required to
develop greater internal shear strength and lower the lateral pressure on the wall. To fully mobilize
strength and reduce lateral pressures, soil strain and allowable wall rotation must be greater for clay
soils than for cohesionless, granular soils.
421 West Main Street Development Engineering Analysis
Bozeman, Montana Page 8
The lowest lateral earth pressure against walls for a given soil type is the active condition and
develops when wall movements occur. Passive earth pressures are developed when the wall is
forced into the soil, such as at the base of a wall on the side opposite the retained earth side. When
no soil strain is allowed by the wall, this is the "at-rest" condition, which creates pressures having
magnitudes between the passive and active conditions.
The distribution of the lateral earth pressures on the structure depends on soil type and wall
movements or deflections. In most cases, a triangular pressure distribution is satisfactory for
design and is usually represented as an equivalent fluid unit weight. Design parameters are given
in the recommendations section of this report.
4.5 Floor Slabs and Exterior Flatwork
The natural on-site soils and fill soils are not recommended for support of interior floor slabs without
improvement to help address settlement concerns. It will be necessary to improve the underslab
conditions by removing and replacing a portion of the lean clay soil or providing subgrade soil
improvements such as EAP beneath the slab systems. The use of EAP improvement beneath
interior slabs is recommended as it will provide a higher level of performance due to their ability to
densify this problematic layer throughout its depth. When EAP systems are considered, a layer of
granular fill directly beneath the interior building slabs is recommended to provide a structural
cushion, a capillary-break from the subgrade, and a drainage medium. The thickness and
aggregate type should be specified by the EAP designer when their system is utilized.
When the expense of EAP improvements beneath the interior slabs is too much for the project,
slabs can be supported on a thickened zone of compacted structural fill isolated from the in-situ
soils using a geotextile. However, this method of construction does not completely address
settlement concerns associated with the lean clay and carries a higher level of risk related to
differential settlements caused by variations in the fill thickness. Conventional interior building and
parking slabs should be supported on at least 18 inches of properly compacted granular fill, which is
separated from the native soils using a woven geotextile. Recommendations for suitable granular
fill materials, geotextiles, and subgrade preparation requirements are included in the
recommendations section of this report for your consideration.
While exterior flatwork would benefit from the use of a similar gravel thickness, this additional
improvement is generally considered cost prohibitive for most projects. In our opinion, the use of
typical slab-on-grade construction consisting of a 6-inch gravel base course overlying native soils
could be utilized for exterior flatwork applications provided the Owner is aware of the potential for
reduced concrete performance. This level of construction will be at an increased risk of cracking
and differential movement associated with seasonal moisture fluctuations, reduced subgrade
strength, and frost penetration into the fine-grained subgrade. However, for most projects the repair
or replacement cost of similar exterior concrete is far less than the expense associated with
alternative improvements. This is not the case for interior slab systems which warrant a higher level
of care as recommended above.
421 West Main Street Development Engineering Analysis
Bozeman, Montana Page 9
4.6 Pavements
A pavement section is a layered system designed to distribute concentrated traffic loads to the
subgrade. Performance of the pavement structure is directly related to the physical properties of the
subgrade soils and the magnitude and frequency of traffic loadings. Pavement design procedures
are based on strength properties of the subgrade and pavement materials, along with the design
traffic conditions. Traffic information was not available at the time of this report. We have assumed
that traffic for the rigid concrete pavements, located in the basement of the proposed structure, will
be limited to passenger-type vehicles only. The exterior asphalt accesses and onsite parking, if any,
are assuming to be utilized by predominantly passenger-type vehicles but may also be utilized by
regular truck traffic associated with trash collection and deliveries. The pavement sections provided
are based on a design equivalent single axle load (ESAL) of 50,000 for the rigid concrete pavement
and exterior asphalt accesses. The ESAL count is a conservative minimum value for parking access
and local streets in the Bozeman area and accounts for the daily traffic over a 20-year design life.
The anticipated subgrade material for this project is lean clay, which is an A-7 soil in accordance
with the American Association of State Highway and Transportation Officials (AASHTO)
classification. AASHTO considers this soil type to be a relatively poor subgrade material when
encountered in a native condition. The uncontrolled fill is susceptible to increased settlement,
moisture sensitivity, and instability which make it a concern for pavement systems. Typical
California Bearing Ratio (CBR) values for these types of soil are less than 2 percent.
A geotextile acting as a separator is recommended between the pavement section gravels and the
prepared clay subgrade. The geotextile will prevent the upward migration of fines, the loss of
aggregate into the subgrade, and aid in the proper compaction of the base course gravels which will
overly the relatively soft yielding subgrade. These benefits of the separation fabric will help to
prolong the structural integrity and performance of the pavement sections.
The pavement section presented in this report is based on an assumed CBR value of one percent,
assumed traffic loadings outlined above, recommended pavement section design information
presented in the Asphalt Institute and AASHTO Design Manuals, and our past pavement design
experience in Bozeman, Montana.
Please note that our design has not considered construction traffic or staging use as part of the
analysis. The sections provided are not suitable for these purposes. If the contractor plans to utilize
the pavement section gravels for construction access roads or as staging areas which will realize
larger construction vehicles and deliveries, we should be consulted to provide additional pavement
recommendations including increased base course thicknesses and additional geosynthetic
reinforcement capable of supporting the larger construction loads.
421 West Main Street Development Recommendations
Bozeman, Montana Page 10
5.0 RECOMMENDATIONS
5.1 Site Grading and Excavations
1. All topsoil and organic material, asphalt, concrete and related construction debris,
and fill should be removed from the proposed building and pavement areas and any
areas to receive site grading fill.
2. All fill and backfill should be non-expansive, free of organics and debris and should
be approved by the project geotechnical engineer. The on-site soils are not
recommended for general site fill or building backfill due to difficulty meeting
compaction requirements. All fill should be placed in uniform lifts not exceeding 8
inches in thickness for fine-grained soils and not exceeding 12 inches for granular
soils. All materials compacted using hand compaction methods or small walk-behind
units should utilize a maximum lift thickness of 6 inches to ensure adequate
compaction throughout the lift. All fill and backfill shall be moisture conditioned to
near the optimum moisture content and compacted to the following percentages of
the maximum dry density determined by a standard proctor test which is outlined by
ASTM D698 or equivalent (e.g. ASTM D4253-D4254).
a) Fill Below Foundations or Spread Footings ................................ 98%
b) Fill Below Slab-on-Grade Construction ....................................... 98%
c) Exterior Foundation Wall Backfill ................................................. 98%
d) Fill Below Streets, Parking Lots, or Other Paved Areas ............. 95%
e) Native Soils Below Slabs ............................................................. 92%
f) General Landscaping or Nonstructural Areas .............................. 92%
g) Utility Trench Backfill, To Within 2 Feet of Surface..................... 95%
For your consideration, verification of compaction requires laboratory proctor tests to
be performed on a representative sample of the soil prior to construction. These
tests can require up to one week to complete (depending on laboratory backlog) and
this should be considered when coordinating the construction schedule to ensure
that delays in construction or additional testing expense is not required due to
laboratory processing times or rush processing fees.
3. The native clay is anticipated to be at moisture contents above optimum at the time
of construction and may not be conducive to conventional compaction methods and
equipment. Excessive compaction could further destabilize the clay causing
pumping and severe rutting.
4. Develop and maintain site grades which will rapidly drain surface and roof runoff
away from foundation and subgrade soils; both during and after construction. The
421 West Main Street Development Recommendations
Bozeman, Montana Page 11
final site grading shall conform to the grading plan, prepared by others to satisfy the
minimum requirements of the applicable building codes.
5. All downspouts should convey directly to the site storm water system, when
possible. However, at a minimum, downspouts from roof drains should discharge at
least six feet away from the foundation or beyond the limits of foundation backfill,
whichever is greater. All downspout discharge areas should be properly graded
away from the structure to promote drainage and prevent ponding.
Downspouts which will discharge directly onto relatively impervious surface (i.e.
asphalt or concrete) may discharge no less than 12 inches from the foundation wall
provided the impervious surfacing is properly graded away from the structure and
continuous within a minimum distance of six feet.
6. Irrigation around the perimeter of individual structures should be avoided.
Landscaping around foundation walls should consider plant varieties that do not
require significant irrigation such as drought-resistant species.
7. Site utilities should be installed with proper bedding in accordance with pipe
manufacturer’s requirements.
8. It is the responsibility of the Contractor to provide safe working conditions in
connection with underground excavations. Temporary construction excavations
greater than four feet in depth, which workers will enter, will be governed by OSHA
guidelines given in 29 CFR, Part 1926. The contractor is responsible to provide an
OSHA knowledgeable individual during all excavation activities to regularly assess
the soil conditions and ensure that all necessary safety precautions are
implemented and followed.
5.2 Conventional Shallow Foundations with EAP System (Recommended)
The native soils are not suitable for the support of conventional shallow foundations without
subgrade improvements. The use of an engineered aggregate pier (EAP) system is recommended.
EAPs are a proprietary system which requires specialized design and construction. We recommend
that you consult with Specialty Foundation Systems (Billings, Montana), GTFC – West (Hillsboro,
Oregon) or Montana Helical Pier (Whitefish, Montana) for their design services associated with this
system; however, other companies are also available for the design of these systems. The
geotechnical data provided should provide adequate information for them to complete their design
based on additional structural information to be provided by your design team. The preliminary
information shown below are not intended for construction, and the future recommendations given
on the plan sheets prepared by the EAP designer will govern the final construction.
421 West Main Street Development Recommendations
Bozeman, Montana Page 12
9. Both interior and exterior footings are anticipated to bear on engineered aggregate
pier (EAP) improved soils designed by others. Typical design bearing pressures for
these systems generally meet or exceed 4,000 psf; however, the actual bearing
pressure to be utilized will be specified by the EAP designer. We recommend the
EAP design be prepared to limit total settlements to less than ¾-inch with differential
movements being one half of the total settlement unless alternative requirements
are provided by the Owner or Architect.
10. Exterior footings and footings beneath unheated areas should be placed at least 48
inches below finished exterior grade for frost protection.
11. Lateral loads are resisted by sliding friction between the footing base and the
supporting soil and by lateral pressure against the footings opposing movement.
For design purposes, a friction coefficient of at least 0.4 is typical for EAP improved
soils and should be specified by the EAP designer. A lateral resistance pressure of
150 psf per foot of depth would be appropriate for foundations backfilled using
imported granual fill assuming relatively thin backfill zones (less than three feet).
12. The EAP designer / installer shall provide their own internal quality control system.
At a minimum, the installer shall record date, time, length, lift thicknesses, and
elevation for each pier installed. Additionally, the results of the test piers and
performance testing shall be documented. Prior to placing structural fill or footings
on EAP improved soils, the designer / installer shall provide a certification stamped
by a Montana Licensed Professional Engineer stating that the piers were properly
installed and can meet the performance requirements noted in Item 9. The
certification letter shall include all testing and internal quality control data.
13. Ground water could be encountered in excavations and EAP installation holes
depending on the time of year installation occurs. Ground water elevations will vary
depending on the time of year and the magnitude of seasonal ground water
fluctuations. The contractor should be prepared to dewater as needed to facilitate
the installation of utilities, foundations, and EAP systems. We recommend
dewatering to an elevation below the bottom of the EAP to ease installation, if
encountered.
5.3 Foundation Walls
The design and construction criteria presented below should be observed for foundation. The
construction details should be considered when preparing the project documents.
14. Backfill placed against the sides of the footings and the base of the walls to resist
lateral loads should be placed and compacted per the requirements of Item 2 above.
421 West Main Street Development Recommendations
Bozeman, Montana Page 13
15. Backfill should be selected, moisture conditioned, placed, and compacted per Item 2
above. Basement walls and other retaining walls which are laterally supported and
can be expected to undergo only a slight amount of deflection should be designed
for a lateral earth pressure computed on the basis of an equivalent fluid unit weight
of 75 pcf for backfill consisting of imported structural fill compacted to 98% of ASTM
D698.
16. Exterior footing drains are required for structures which incorporate a below grade
space (basement, crawlspace, etc.) or any structure in which the interior floor
elevation is set lower than the finished exterior grade. Exterior footing drains are
recommended to remove ground water seepage and infiltrated surface runoff away
from foundation soils. This is especially important along basement walls. Drains
should consist of a minimum 3-inch diameter, geotextile-wrapped, flexible, slotted
pipe (ADS) or perforated, SDR 35, 4-inch diameter, PVC drain tile in poorly-graded
gravel with geotextile placed at or below exterior footing grade. Drains shall be
covered by at least 12 inches of free-draining, open-graded, granular material. The
open-graded granular material should be enveloped in a geotextile to prevent the
migration of fines. Use of a single piece of geotextile with a full-width lap at the top
is preferred; however, two separate pieces of fabric may be used provided a
minimum overlap distance of 12 inches is maintained at all joints. Drains should be
sloped to an interior sump or a storm water system. A typical perimeter foundation
drain is shown on Construction Standard No. 02801-06C.
5.4 Floor Slabs and Exterior Flatwork
17. For normally loaded, exterior concrete flatwork, a typical cushion course consisting
of free-draining, crushed gravel should be placed beneath the concrete and
compacted to the requirements of Item 2 above. Cushion course thicknesses
generally range from four to six inches but may vary based on local requirements.
Conventional construction, as has been described, is not intended to mitigate
expansion or settlement concerns associated with the subsurface conditions
encountered. In most cases, the cost to repair and/or replace exterior flatwork when
excessive movements occur is far more economical than efforts to mitigate these
movements. However, if no acceptable risk of movements for exterior flatwork is
acceptable for this project, standard construction is not appropriate and additional
mitigative efforts described in Item 19 are warranted.
18. Prior to placing exterior concrete flatwork, the top 12 inches of subgrade should be
scarified and recompacted to the requirements of Item 2.
19. Interior floor slabs should be supported on engineered aggregate pier (EAP)
improved soils, designed by others, for optimal performance and to help address
settlement concerns.
421 West Main Street Development Recommendations
Bozeman, Montana Page 14
20. When the expense associated with EAP improvements beneath interior slabs is not
viable, normally loaded, interior slab-on-grade construction, can be supported on a
thickened section of at least 18 inches of compacted granular fill. The gravel should
be separated from the prepared subgrade using a woven Mirafi HP270 or equivalent
geotextile. Such construction is not intended to eliminate or control potential
settlements associated with construction over the lean clay and higher level of slab
movement and distress should be expected.
21. Cushion course materials utilized beneath slab-on-grade applications should
conform to the requirements outlined in Section 02235 of the Montana Public Works
Standard Specifications (MPWSS). All gradation outlined in this specification are
acceptable for this application. Prior to placing the cushion course, the upper six
inches of subgrade should be compacted per Item 2.
22. Geotechnically, an underslab vapor barrier is not required for this project. A vapor
barrier is normally used to limit the migration of soil gas and moisture into occupied
spaces through floor slabs. The need for a vapor barrier should be determined by
the architect and/or structural engineer based on interior improvements and/or
moisture and gas control requirements.
5.5 Pavements
23. The following pavement section or an approved equivalent section should be
selected in accordance with the discussions in the Engineering Analysis.
Pavement Component Component Thickness
Rigid Concrete
Pavement (Interior)
Flexible Asphalt
Pavement
Asphalt Pavement ----- 3”
Portland Cement Concrete Pavement 6” -----
Crushed Base Course 12” 6”
Crushed Subbase Course ----- 18”
Separation Geotextile (Item 27) YES YES
Total 18” 27”
NOTE: These pavement sections are not intended to be utilized by construction traffic or staging during construction. A larger
pavement section and/or additional geosynthetic reinforcement are warranted if it is to be utilized in this manner.
421 West Main Street Development Recommendations
Bozeman, Montana Page 15
24. Final pavement thicknesses exceeding 3 inches shall be constructed in two uniform
lifts.
25. Gradations for the crushed base courses shall conform to Section 02235 of the
Montana Public Works Standard Specifications (MPWSS). All gradations outlined in
this specification are acceptable for this application based on the local availability
and contractor preference. The gradation for the subbase shall conform to Section
02234 of the MPWSS and incorporate a maximum particle size of 3-inch. All
materials containing less than 70 percent passing the ¾-inch sieve shall utilize a
relative density test outlined in ASTM D4253-4254 to determine the field density to
be utilized during construction testing.
26. Where the existing grades will be raised more than the thickness of the pavement
section, all fill should be placed, compacted and meet the general requirements
given in Item 2 above.
27. A geotextile is recommended between the pavement section and the prepared
subgrade to prevent the migration of fines upward into the gravel and the loss of
aggregate into the subgrade. A Mirafi HP270 or equivalent geotextile is suitable for
this site.
28. The asphaltic cement should be a Performance Graded (PG) binder having the
following minimum high and low temperature values based on the desired pavement
reliability.
Reliability Min. High
Temp Rating
Min. Low
Temp Rating Ideal Oil Grade
50% 35.6 -23.6 PG 52-28
98% 39.5 -32.5 PG 52-34
For most low volume parking lot applications, a 50 percent reliability is considered
sufficient. For this reliability level, a PG 58-28 grade oil is recommended as this is
anticipated to be the most commonly available product to provide suitable low
temperature resistance to thermal cracking. The use of a PG 52-34 or 58-34 oil
would provide higher reliability and improved thermal cracking resistance; however,
it will also likely result in higher construction costs associated with a specialized
asphalt binder which is not commonly utilized by local suppliers.
29. The concrete pavement section shown in item 23 assumes that the concrete will
provide a minimum compressive strength of 4,000 psi and a minimum modulus of
rupture of 570 psi for the section thicknesses outlined above. If the concrete
materials available cannot meet these minimum requirements, the concrete
pavement section warrants modification, and we should be consulted to assist with
421 West Main Street Development Recommendations
Bozeman, Montana Page 16
determining the appropriate section for the concrete properties to be utilized on the
project.
A modulus of vertical subgrade reaction no greater than 50 psi is appropriate for the
design of the concrete reinforcing by others.
5.6 Continuing Services
Three additional elements of geotechnical engineering service are important to the successful
completion of this project.
30. Consultation between the geotechnical engineer and the design professionals
during the design phases is highly recommended. This is important to ensure that
the intentions of our recommendations are incorporated into the design, and that
any changes in the design concept consider the geotechnical limitations dictated by
the on-site subsurface soil and ground water conditions.
31. Observation, monitoring, and testing during construction is required to document the
successful completion of all earthwork and foundation phases. A geotechnical
engineer from our firm should be retained to observe the excavation, earthwork, and
foundation phases of the work to determine that subsurface conditions are
compatible with those used in the analysis and design.
32. During site grading, placement of all fill and backfill should be observed and tested
to confirm that the specified density has been achieved. We recommend that the
Owner maintain control of the construction quality control by retaining the services of
an experienced construction materials testing laboratory. We are available to
provide construction inspection services as well as materials testing of compacted
soils and the placement of Portland cement concrete and asphalt. In the absence of
project specific testing frequencies, TD&H recommends the following minimum
testing frequencies be used:
Compaction Testing
Beneath Column Footings N/A – EAP Improved Soil
Beneath Wall Footings N/A – EAP Improved Soil
Beneath Slabs 1 Test per 1,500 SF per Lift
Foundation Backfill 1 Test per 100 LF of Wall per Lift
Parking Lot & Access Roads 1 Test per 2,500 SF per Lift
LF = Lineal Feet SF = Square Feet
421 West Main Street Development Summary of Field & Laboratory Studies
Bozeman, Montana Page 17
6.0 SUMMARY OF FIELD AND LABORATORY STUDIES
6.1 Field Explorations
The field explorations were performed over two investigations on February 19, March 21, and
March 22, 2022. A total of four borings and one test pit were drilled and excavated to depths
ranging from 14.5 to 30.5 feet at the locations shown on Figure 1 to observe subsurface soil and
ground water conditions. The borings were advanced through the subsurface soils using a truck-
mounted Mobile B-61 drill rig equipped with 4.25-inch I.D hollowstem augers. The tests pit was
excavated using a Komatsu PC 140 tracked excavator. The subsurface exploration and sampling
methods used are indicated on the attached boring and test pit logs. The borings and test pit were
logged by Mr. Ahren Hastings, PE, and Mr. Nic Couch, EI of TD&H Engineering.
Grab samples of the various strata were collected from excavation spoils as the excavation
proceeded. Samples of the subsurface materials were also taken during drilling using a1⅜-inch I.D.
split spoon sampler. The samplers were driven 18 inches, when possible, into the various strata
using a 140-pound drop hammer falling 30 inches onto the drill rods. For each sample, the number
of blows required to advance the sampler each successive six-inch increment was recorded, and
the total number of blows required to advance the sampler the final 12 inches is termed the
penetration resistance (“N-value”). This test is known as the Standard Penetration Test (SPT)
described by ASTM D1586. Penetration resistance values indicate the relative density of granular
soils and the relative consistency of fine-grained soils. Samples were also obtained by hydraulically
pushing a 3-inch I.D., thin-walled Shelby tube sampler into the subsoils. Logs of all soil borings and
the test pit, which include soil descriptions, sample depths, and penetration resistance values, are
presented on the Figures 2 through 6.
Measurements to determine the depth of ground water in the test pits and borings were made using
a hundred-foot reel tape shortly after the completion of excavating and drilling. The depths or
elevations of the water levels measured, if encountered, and the date of measurement are shown
on the boring and test pit logs.
6.2 Laboratory Testing
Samples obtained during the field exploration were returned to our materials laboratory where they
were observed and visually classified in general accordance with ASTM D2487, which is based on
the Unified Soil Classification System. Representative samples were selected for testing to
determine the engineering and physical properties of the soils in general accordance with ASTM or
other approved procedures.
Tests Conducted: To determine:
Natural Moisture Content Representative moisture content of soil at the time of
sampling.
421 West Main Street Development Summary of Field & Laboratory Studies
Bozeman, Montana Page 18
Grain-Size Distribution Particle size distribution of soil constituents describing the
percentages of clay/silt, sand and gravel.
Atterberg Limits A method of describing the effect of varying water content on
the consistency and behavior of fine-grained soils.
Moisture-Density Relationship A relationship describing the effect of varying moisture
content and the resulting dry unit weight at a given
compactive effort. Provides the optimum moisture content
and the maximum dry unit weight. Also called a Proctor
Curve.
The laboratory testing program for this project consisted of 30 moisture-visual analyses, 6 sieve
(grain-size distribution) analyses, and 4 Atterberg Limits analyses. The results of the water content
analyses are presented on the boring and test pit logs, Figures 2 through 6. The grain-size
distribution curves and Atterberg limits are presented on Figures 7 through 16. In addition, one
proctor (moisture-density) test was performed and the result is presented on Figure 17.
421 West Main Street Development Limitations
Bozeman, Montana Page 19
7.0 LIMITATIONS
This report has been prepared in accordance with generally accepted geotechnical engineering
practices in this area for use by the client for design purposes. The findings, analyses, and
recommendations contained in this report reflect our professional opinion regarding potential
impacts the subsurface conditions may have on the proposed project and are based on site
conditions encountered. Our analysis assumes that the results of the exploratory borings and test
pit are representative of the subsurface conditions throughout the site, that is, that the subsurface
conditions everywhere are not significantly different from those disclosed by the subsurface study.
Unanticipated soil conditions are commonly encountered and cannot be fully determined by a
limited number of soil borings, test pits, and laboratory analyses. Such unexpected conditions
frequently require that some additional expenditures be made to obtain a properly constructed
project. Therefore, some contingency fund is recommended to accommodate such potential extra
costs.
The recommendations contained within this report are based on the subsurface conditions
observed in the borings and test pit and are subject to change pending observation of the actual
subsurface conditions encountered during construction. TD&H cannot assume responsibility or
liability for the recommendations provided if we are not provided the opportunity to perform limited
construction inspection and confirm the engineering assumptions made during our analysis. A
representative of TD&H should be retained to observe all construction activities associated with
subgrade preparation, foundations, and other geotechnical aspects of the project to ensure the
conditions encountered are consistent with our assumptions. Unforeseen conditions or undisclosed
changes to the project parameters or site conditions may warrant modification to the project
recommendations.
Long delays between the geotechnical investigation and the start of construction increase the
potential for changes to the site and subsurface conditions which could impact the applicability of
the recommendations provided. If site conditions have changed because of natural causes or
construction operations at or adjacent to the site, TD&H should be retained to review the contents of
this report to determine the applicability of the conclusions and recommendations provide
considering the time lapse or changed conditions.
Misinterpretation of the geotechnical information by other design team members is possible and can
result in costly issues during construction and with the final product. Our geotechnical engineers
are available upon request to review those portions of the plans and specifications which pertain to
earthwork and foundations to determine if they are consistent with our recommendations and to
suggest necessary modifications as warranted. This service was not included in the original scope
of the project and will require additional fees for the time required for specification and plan
document review and comment. In addition, TD&H should be involved throughout the construction
process to observe construction, particularly the placement and compaction of all fill, preparation of
all foundations, and all other geotechnical aspects. Retaining the geotechnical engineer who
421 West Main Street Development Limitations
Bozeman, Montana Page 20
prepared your geotechnical report to provide construction observation is the most effective method
of managing the risks associated with unanticipated conditions.
This report was prepared for the exclusive use of the owner and architect and/or engineer in the
design of the subject facility. It should be made available to prospective contractors and/or the
contractor for information on factual data only and not as a warranty of subsurface conditions such
as those interpreted from the boring and test pit logs and presented in discussions of subsurface
conditions included in this report.
Prepared by: Reviewed by:
Kyle Scarr, PE & Principal Craig Nadeau PE & Principal
Geotechnical Engineer Geotechnical Manager
TD&H ENGINEERING TD&H ENGINEERING
SHEETREVISIONSHEETDESIGNED BY:QUALITY CHECK:JOB NO.FIELDBOOKDRAWN BY:DATE:B22-007 BORING MAPREV DATE NOT FORCONSTRUCTION
421 WEST MAIN STREET
BOZEMAN, MONTANA
APPROXIMATE TEST PIT & BORING LOCATIONS B22-0072022.04.11.DWGFIG. 1TRB-KLSEngineering
tdhengineering.com
0
3
6
9
12
15
18
21
ASPHALT Pavement
CONCRETE Pavement
FILL: Poorly-Graded GRAVEL with Sand (Base),
relatively dense, light brown, slightly moist, concrete
pieces
Lean CLAY, very soft to stiff, brown, slightly moist
Clayey GRAVEL with Sand, very dense, brown and
gray, slightly moist to wet
0.3
0.7
2.5
17.0
49-6-7
2-1-2
2-1-1
1-0-1
2-3-4
29-50/
5"50/5"
LEGEND LOG OF SOIL BORING B-1SPT blows per foot Atterberg Limits
Field Moisture content 421 West Main Street
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Ahren Hastings, PE
2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling
Truck-mounted Mobile B-61 with 4.25-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
March 21, 2022 B22-007-001
No sample recovery Figure No. 2
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
1 of 2
24
27
30
33
36
39
42
Bottom of Boring
30.5
18-28-
28
20-28-
28
56
56
LEGEND LOG OF SOIL BORING B-1SPT blows per foot Atterberg Limits
Field Moisture content 421 West Main Street
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Ahren Hastings, PE
2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling
Truck-mounted Mobile B-61 with 4.25-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
March 21, 2022 B22-007-001
No sample recovery Figure No. 2
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
2 of 2
0
3
6
9
12
15
18
21
ASPHALT Pavement
CONCRETE Pavement
FILL: Poorly-Graded GRAVEL with Sand (Base),
relatively dense, light brown, slightly moist, concrete
pieces
Lean CLAY, soft to firm, brown, slightly moist
Clayey GRAVEL with Sand, medium dense to very
dense, brown and gray, slightly moist
0.1
0.7
2.0
15.0
3-3-4
3-2-1
3-3-4
3-4-4
3-4-22
30-45-
50/3"95/9"
LEGEND LOG OF SOIL BORING B-2SPT blows per foot Atterberg Limits
Field Moisture content 421 West Main Street
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Ahren Hastings, PE
2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling
Truck-mounted Mobile B-61 with 4.25-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
March 22, 2022 B22-007-001
No sample recovery Figure No. 3
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
1 of 2
24
27
30
33
36
39
42
- No Sample Recovered
Bottom of Boring
25.5
Ground
water
not
encoun-
tered
29-50/
2"
50/2"
LEGEND LOG OF SOIL BORING B-2SPT blows per foot Atterberg Limits
Field Moisture content 421 West Main Street
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Ahren Hastings, PE
2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling
Truck-mounted Mobile B-61 with 4.25-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
March 22, 2022 B22-007-001
No sample recovery Figure No. 3
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
2 of 2
0
3
6
9
12
15
18
21
ASPHALT Pavement
CONCRETE Pavement
FILL: Poorly-Graded GRAVEL with Sand (Base),
relatively dense, light brown, slightly moist, concrete
pieces
Lean CLAY, soft to firm, brown, slightly moist
Clayey GRAVEL with Sand, very dense, brown and
gray, slightly moist
0.2
0.6
3.0
16.0
8-9-4
1-2-2
2-2-2
2-3-3
2-3-5
23-50/
5"50/5"
LEGEND LOG OF SOIL BORING B-3SPT blows per foot Atterberg Limits
Field Moisture content 421 West Main Street
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Ahren Hastings, PE
2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling
Truck-mounted Mobile B-61 with 4.25-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
March 22, 2022 B22-007-001
No sample recovery Figure No. 4
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
1 of 2
24
27
30
33
36
39
42
Bottom of Boring
25.5
Ground
water
not
encoun-
tered
20-50/
2"50/2"
LEGEND LOG OF SOIL BORING B-3SPT blows per foot Atterberg Limits
Field Moisture content 421 West Main Street
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Ahren Hastings, PE
2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling
Truck-mounted Mobile B-61 with 4.25-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
March 22, 2022 B22-007-001
No sample recovery Figure No. 4
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
2 of 2
0
3
6
9
12
15
18
21
ASPHALT Pavement
CONCRETE Pavement
FILL: Poorly-Graded GRAVEL with Sand (Base),
relatively dense, light brown, slightly moist, concrete
pieces
Lean CLAY, soft to firm, brown, slightly moist
Clayey GRAVEL with Sand, very dense, brown and
gray, slightly moist to moist
0.2
0.6
4.0
15.0
9-4-4
3-3-3
3-2-1
1-3-3
2-9-36
50/5"50/5"
LEGEND LOG OF SOIL BORING B-4SPT blows per foot Atterberg Limits
Field Moisture content 421 West Main Street
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Ahren Hastings, PE
2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling
Truck-mounted Mobile B-61 with 4.25-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
March 22, 2022 B22-007-001
No sample recovery Figure No. 5
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
1 of 2
24
27
30
33
36
39
42
Bottom of Boring
30.5
24-50/
4"
36-30-
50/4"
50/4"
50/4"
LEGEND LOG OF SOIL BORING B-4SPT blows per foot Atterberg Limits
Field Moisture content 421 West Main Street
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Ahren Hastings, PE
2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling
Truck-mounted Mobile B-61 with 4.25-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
March 22, 2022 B22-007-001
No sample recovery Figure No. 5
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
2 of 2
0
2.5
5
7.5
10
12.5
15
17.5
ASPHALT Pavement
CONCRETE
Poorly-Graded GRAVEL with Clay and Sand, appears
medium dense, dark brown, moist (Base Course)
FILL: Fat CLAY, appears firm, dark brown, moist, some
cobbles
Lean CLAY, relatively soft, brown to light brown, moist
- See Figure 17 for proctor result
- Tan below 10.5 feet
Bottom of Test Pit
0.3
0.8
1.0
2.5
14.5
Ground
water
not
encoun-
tered
G
G
LEGEND LOG OF TEST PIT TP-1Atterberg Limits
Field Moisture content 421 West Main Street
Bozeman, MontanaGroundwater Level
Grab/composite sample
Logged by:Nic Couch, EI
Excavated by:Earth Surgeons
Komatsu PC 140GNP = Granular and Nonplastic
Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
February 19, 2022 B22-007-001
Figure No. 6
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT
0 10 20 30 40 50
= MOISTURE CONTENT
1 of 1
Tested By: BS Checked By:
4-6-2022
7
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Lean CLAY
1.5"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
99.9
99.8
99.5
99.4
99.1
99.0
99.0
98.9
98.6
98.2
97.8
94.8
18 36 18
CL A-6(17)
Report No. A-24132-206
Reuter Walton Development
421 West Main Street
Bozeman, Montana
B22-007-001
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: TP-1
Sample Number: A-25132 Depth: 2.5 - 3.5 ft Date:
Client:
Project:
Project No:Figure
SIEVE PERCENT SPEC.
*PASS?
SIZE FINER PERCENT (X=NO)PERCENT FINER0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.00010.0010.010.1110100
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 0.2 0.7 0.1 0.1 4.1 94.86 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report
Tested By: BS/MS Checked By:
4-6-2022
8
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Lean CLAY
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
100.0
99.9
99.8
99.7
99.6
99.3
98.8
98.2
97.7
94.0
18 45 27
CL A-7-6(27)
Report No. A-25133-206
Reuter Walton Development
421 West Main Street
Bozeman, Montana
B22-007-001
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: TP-1
Sample Number: A-25133 Depth: 10.5 - 12.5 ft Date:
Client:
Project:
Project No:Figure
SIEVE PERCENT SPEC.
*PASS?
SIZE FINER PERCENT (X=NO)PERCENT FINER0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.00010.0010.010.1110100
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 0.0 0.2 0.1 0.4 5.3 94.06 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report
Tested By: BC Checked By:
4-1-2022
9
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Lean CLAY with Sand
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
97.9
96.1
96.1
94.5
92.4
89.6
86.7
84.4
75.6
0.2653 0.1566
CL
Report No. A-25138-206
Reuter Walton Development
421 West Main Street
Bozeman, Montana
B22-007-001
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: B-1
Sample Number: A-25138 Depth: 14.0 - 15.5 ft Date:
Client:
Project:
Project No:Figure
SIEVE PERCENT SPEC.
*PASS?
SIZE FINER PERCENT (X=NO)PERCENT FINER0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.00010.0010.010.1110100
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 0.0 3.9 0.0 3.7 16.8 75.66 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report
Tested By: WJC Checked By:
3-31-2022
10
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Clayey GRAVEL with Sand
1.5"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
97.7
84.5
74.6
68.1
53.9
41.0
32.3
26.3
22.5
20.1
18.6
13.9
21.4044 19.2839 6.5387
3.7695 0.6623 0.0897
GC
Report No. A-25139COMP-206
Reuter Walton Development
421 West Main Street
Bozeman, Montana
B22-007-001
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: B-1 Through B-4 Composite
Sample Number: A-25139COMP Depth: 14.0 - 20.5 ft Date:
Client:
Project:
Project No:Figure
SIEVE PERCENT SPEC.
*PASS?
SIZE FINER PERCENT (X=NO)PERCENT FINER0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.00010.0010.010.1110100
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 15.5 30.6 12.9 14.7 12.4 13.96 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report
Tested By: WJC Checked By:
3-31-2022
11
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Clayey GRAVEL with Sand
1.5"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
92.9
87.7
77.0
70.9
58.6
47.0
38.3
33.0
30.2
28.4
27.4
24.0
21.3746 17.0997 5.1725
2.5755 0.2412
GC
Report No. A-25140COMP-206
Reuter Walton Development
421 West Main Street
Bozeman, Montana
B22-007-001
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: B-1 Through B-4 Composite
Sample Number: A-25140COMP Depth: 24.0 - 30.5 ft Date:
Client:
Project:
Project No:Figure
SIEVE PERCENT SPEC.
*PASS?
SIZE FINER PERCENT (X=NO)PERCENT FINER0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.00010.0010.010.1110100
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 12.3 29.1 11.6 14.0 9.0 24.06 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report
Tested By: BC Checked By:
4-1-2022
12
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Lean CLAY
#4
#10
#20
#40
#60
#80
#100
#200
100.0
100.0
99.9
99.8
99.6
99.3
99.0
95.5
CL
Report No. A-25150-206
Reuter Walton Development
421 West Main Street
Bozeman, Montana
B22-007-001
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: B-3
Sample Number: A-25150 Depth: 4.0 - 5.5 ft Date:
Client:
Project:
Project No:Figure
SIEVE PERCENT SPEC.
*PASS?
SIZE FINER PERCENT (X=NO)PERCENT FINER0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.00010.0010.010.1110100
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 0.0 0.0 0.0 0.2 4.3 95.56 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report
Tested By: BC Checked By:
LIQUID AND PLASTIC LIMITS TEST REPORT
PLASTICITY INDEX0
10
20
30
40
50
60
LIQUID LIMIT
0 10 20 30 40 50 60 70 80 90 100 110
CL-ML
C L o r O L
C H o r O H
ML or OL MH or OH
Dashed line indicates the approximate
upper limit boundary for natural soils
47
WATER CONTENT35.2
35.6
36
36.4
36.8
37.2
37.6
38
38.4
38.8
39.2
NUMBER OF BLOWS
5 6 7 8 9 10 20 25 30 40
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
Project No. Client:Remarks:
Project:
Location: TP-1
Sample Number: A-25132 Depth: 2.5 - 3.5 ft
Figure
Lean CLAY 36 18 18 98.9 94.8 CL
B22-007- Reuter Walton Development
13
Report No. A-25132-207
Date: 4-6-2022421 West Main Street
Bozeman, Montana
Tested By: BC Checked By:
LIQUID AND PLASTIC LIMITS TEST REPORT
PLASTICITY INDEX0
10
20
30
40
50
60
LIQUID LIMIT
0 10 20 30 40 50 60 70 80 90 100 110
CL-ML
C L o r O L
C H o r O H
ML or OL MH or OH
Dashed line indicates the approximate
upper limit boundary for natural soils
47
WATER CONTENT41
42
43
44
45
46
47
48
49
50
51
NUMBER OF BLOWS
5 6 7 8 9 10 20 25 30 40
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
Project No. Client:Remarks:
Project:
Location: TP-1
Sample Number: A-25133 Depth: 10.5 - 12.5 ft
Figure
Lean CLAY 45 18 27 99.3 94.0 CL
B22-007- Reuter Walton Development
14
Report No. A-25133-207
Date: 4-6-2022421 West Main Street
Bozeman, Montana
Tested By: BC Checked By:
LIQUID AND PLASTIC LIMITS TEST REPORT
PLASTICITY INDEX0
10
20
30
40
50
60
LIQUID LIMIT
0 10 20 30 40 50 60 70 80 90 100 110
CL-ML
C L o r O L
C H o r O H
ML or OL MH or OH
Dashed line indicates the approximate
upper limit boundary for natural soils
47
WATER CONTENT35.8
36.2
36.6
37
37.4
37.8
38.2
38.6
39
39.4
39.8
NUMBER OF BLOWS
5 6 7 8 9 10 20 25 30 40
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
Project No. Client:Remarks:
Project:
Location: B-2
Sample Number: A-25146 Depth: 14.0 - 15.0 ft
Figure
Lean CLAY 37 18 19 CL
B22-007- Reuter Walton Development
15
Report No. A-25146-207
Date: 4-1-2022421 West Main Street
Bozeman, Montana
Tested By: BC Checked By:
LIQUID AND PLASTIC LIMITS TEST REPORT
PLASTICITY INDEX0
10
20
30
40
50
60
LIQUID LIMIT
0 10 20 30 40 50 60 70 80 90 100 110
CL-ML
C L o r O L
C H o r O H
ML or OL MH or OH
Dashed line indicates the approximate
upper limit boundary for natural soils
47
WATER CONTENT35.4
35.8
36.2
36.6
37
37.4
37.8
38.2
38.6
39
39.4
NUMBER OF BLOWS
5 6 7 8 9 10 20 25 30 40
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
Project No. Client:Remarks:
Project:
Location: B-4
Sample Number: A-25157 Depth: 4.0 - 5.5 ft
Figure
Lean CLAY 36 19 17 CL
B22-007- Reuter Walton Development
16
Report No. A-25157-207
Date: 4-1-2022421 West Main Street
Bozeman, Montana
Tested By: BS Checked By:
Moisture-Density Test Report
Dry density, pcf95
97.5
100
102.5
105
107.5
Water content, %
5 10 15 20 25 30 35
17.6%, 106.1 pcf
ZAV for
Sp.G. =
2.65
Test specification:ASTM D 698-12 Method A Standard
2.5 - 3.5 ft CL A-6(17) 2.65 36 18 0.9 94.8
Lean CLAY
B22-007- Reuter Walton Development
Report No. A-25132-204
Date: 4-6-2022
17
Elev/ Classification Nat.Sp.G. LL PI
% > % <
Depth USCS AASHTO Moist.#4 No.200
TEST RESULTS MATERIAL DESCRIPTION
Project No. Client:Remarks:
Project:
Location: TP-1 Sample Number: A-25132
Figure
Maximum dry density = 106.1 pcf
Optimum moisture = 17.6 %
421 West Main Street
Bozeman, Montana
THOMAS, DEAN & HOSKINS, INC.
ENGINEERING CONSULTANTS
CONSTRUCTION STANDARD NO. 02801-06C
PERIMETER FOUNDATION DRAIN
RESIDENTIAL CONSTRUCTION
General Project Information
Project Number: B22-007
Project Title: 421 W Main St
Project Description:
Climatic Data Source (MERRA)
Latitude, Degree: 45.67971
Longitude, Degree: -111.04348
Climatic Data
Lowest Yearly Air Temperature, ºC: -31.20
Low Air Temp Standard Deviation, ºC: 5.17
Yearly Degree-Days > 10 Deg. ºC: 1652.47
High Air Temperature of high 7 days: 29.27
Standard Dev. of the high 7 days: 2.03
Low Pavement Temperature 50%: -30.50
Low Pavement Temperature 98%: -39.40
High Avg Pavement Temperature of 7 Days 50%: 51.19
High Avg Pavement Temperature of 7 Days 98%: 55.39
Target Rut Depth
Target Rut Depth (mm): 16.5
Temperature Adjustments
Depth of Layer, mm: 0
Base HT PG: 52
Traffic Adjustments
Traffic loading Cumulative ESAL for the Design Period, Millions: 0.05
Traffic Speed (Fast: >70 km/h, Slow: 20-70 km/h, Standing: < 20 km/h): Standing
Performance Grade
AASHTO M323-13 Performance-Graded Asphalt Binder
PG Temperature High Low
Performance Grade Temperature at 50% Reliability 35.7 -23.6
Performance Grade Temperature at 98% Reliability 39.6 -32.4
Adjustment for Traffic (AASHTO M323-13)2.8
Adjustment for Depth 0.0 -0.0
Adjusted Performance Grade Temperature 42.4 -32.4
Selected PG Grade 52 -34
PG Grade M323, PG 52-34
AASHTO M 332-14 Performance-Grade Asphalt Binder using Multiple Stress Creep Recovery (MSCR) Test
PG Temperature High Low
Performance Grade Temperature at 50% Reliability 35.7 -23.6
Performance Grade Temperature at 98% Reliability 39.6 -32.4
Designation for traffic loading V
Selected PG Grade 46 -34
PG Grade M332, PG 46V-34
Temperature Report
Lowest Yearly Air Temperature, ºC:-31.20
Low Air Temp Standard Deviation, ºC:5.17
Yearly Degree-Days > 10 Deg. ºC:1652.47
High Air Temperature of high 7 days:29.27
Standard Dev. of the high 7 days:2.03
Low Pavement Temperature 50%:-30.50
Low Pavement Temperature 98%:-39.40
High Avg Pavement Temperature of 7 Days 50%:51.19
High Avg Pavement Temperature of 7 Days 98%:55.39
Great Falls, Kalispell, Bozeman, Montana
Spokane, Washington, Lewiston, Idaho
THOMAS, DEAN & HOSKINSEngineering Consultants SOIL CLASSIFICATION AND
SAMPLING TERMINOLOGY
FOR ENGINEERING PURPOSES
12" 3" 3/4" No.4 No.10 No.40 No.200 <No.200
SILTS & CLAYSBOULDERSCOBBLESGRAVELSSANDS
PARTICLE SIZE RANGE
(Distinguished By
Atterberg Limits)FineCoarse FineMediumCoarse
Sieve Openings (Inches)Standard Sieve Sizes
CL - Lean CLAY
ML - SILT
OL - Organic SILT/CLAY
CH - Fat CLAY
MH - Elastic SILT
OH - Organic SILT/CLAY
SW - Well-graded SAND
SP - Poorly-graded SAND
SM - Silty SAND
SC - Clayey SAND
GW - Well-graded GRAVEL
GP - Poorly-graded GRAVEL
GM - Silty GRAVEL
GC - Clayey GRAVEL
* Based on Sampler-Hammer Ratio of 8.929 E-06 ft/lbf and 4.185 E-05 ft^2/lbf for
granular and cohesive soils, respectively (Terzaghi)
STANDARD PENETRATION TEST (ASTM D1586)
RELATIVE DENSITY*RELATIVE CONSISTENCY*
Granular, Noncohesive
(Gravels, Sands, & Silts)Fine-Grained, Cohesive
(Clays)
Very Loose
Loose
Medium Dense
Dense
Very Dense
Very Soft
Soft
Firm
Stiff
Very Stiff
Hard
0-2
3-4
5-8
9-15
15-30
+30
0-4
5-10
11-30
31-50
+50
Standard
Penetration Test
(blows/foot)
Standard
Penetration Test
(blows/foot)
PLASTICITY CHART
0 10 16 20 30 40 50 60 70 80 90 100 110
60
50
40
30
20
107
4
C L or O LC H or O H
ML or OL
MH or OH
CL-ML "U - LIN E""A - LIN E"LIQUID LIMIT (LL)PLASTICITY INDEX (PI)For classification of fine-grained soils and thefine-grained fraction of coarse-grained soils.
Equation of "A"-line
Horizontal at PI = 4 to LL = 25.5,
then PI = 0.73 (LL-20)
Equation of "U"-line
Vertical at LL = 16 to PI = 7,
then PI = 0.9 (LL-8)
Great Falls, Kalispell, Bozeman, Montana
Spokane, Washington, Lewiston, Idaho
THOMAS, DEAN & HOSKINSEngineering Consultants ASTM D2487
CLASSIFICATION OF SOILS
FOR ENGINEERING PURPOSES
Flow Chart For Classifying Coarse-Grained Soils (More Than 50 % Retained On The No. 200 Sieve)
Flow Chart For Classifying Fine-Grained Soils ( 50 % Or More Passes The No. 200 Sieve)
<5% fines
5-12% fines
>12% fines
<5% fines
5-12% fines
>12% fines
Well-graded GRAVELWell-graded GRAVEL with sandPoorly-graded GRAVELPoorly-graded GRAVEL with sand
Well-graded GRAVEL with silt
Well-graded GRAVEL with silt and sandWell-graded GRAVEL with clay (or silty clay)Well-graded GRAVEL with clay and sand (or silty clay and sand)
Poorly-graded GRAVEL with silt
Poorly-graded GRAVEL with silt and sand
Poorly-graded GRAVEL with clay (or silty clay)Poorly-graded GRAVEL with clay and sand (or silty clay and sand)
Silty GRAVELSilty GRAVEL with sandClayey GRAVELClayey GRAVEL with sandSilty, clayey GRAVEL
Silty, clayey GRAVEL with sand
Well-graded SAND
Well-graded SAND with gravel
Poorly-graded SANDPoorly-graded SAND with gravel
Well-graded SAND with silt
Well-graded SAND with silt and gravel
Well-graded SAND with clay (or silty clay)Well-graded SAND with clay and gravel (or silty clay and gravel)
Poorly-graded SAND with siltPoorly-graded SAND with silt and gravelPoorly-graded SAND with clay (or silty clay)
Poorly-graded SAND with clay and gravel
(or silty clay and gravel)
Silty SANDSilty SAND with gravelClayey SAND
Clayey SAND with gravel
Silty, clayey SAND
Silty, clayey SAND with gravel
<15% sand>15% sand
<15% sand
>15% sand
<15% sand>15% sand
<15% sand
>15% sand
<15% sand>15% sand<15% sand>15% sand
<15% sand>15% sand<15% sand>15% sand<15% sand
>15% sand
<15% gravel
>15% gravel
<15% gravel>15% gravel
<15% gravel>15% gravel<15% gravel>15% gravel
<15% gravel
>15% gravel<15% gravel>15% gravel
<15% gravel
>15% gravel<15% gravel>15% gravel<15% gravel>15% gravel
Lean CLAYLean CLAY with sandLean CLAY with gravelSandy lean CLAY
Sandy lean CLAY with gravel
Gravelly lean CLAY
Gravelly lean CLAY with sand
Silty CLAY
Silty CLAY with sand
Silty CLAY with gravel
Sandy silty CLAYSandy silty CLAY with gravelGravelly silty CLAYGravelly silty CLAY with sand
SILT
SILT with sandSILT with gravelSandy SILTSandy SILT with gravel
Gravelly SILT
Gravelly SILT with sand
Fat CLAYFat CLAY with sand
Fat CLAY with gravel
Sandy fat CLAYSandy fat CLAY with gravelGravelly fat CLAYGravelly fat CLAY with sand
Elastic SILT
Elastic SILT with sand
Elastic SILT with gravelSandy elastic SILTSandy elastic SILT with gravelGravelly elastic SILT
Gravelly elastic SILT with sand
%sand > %gravel
%sand < %gravel
<15% gravel>15% gravel<15% sand>15% sand
%sand > %gravel
%sand < %gravel<15% gravel>15% gravel<15% sand
>15% sand
%sand > %gravel%sand < %gravel
<15% gravel>15% gravel<15% sand>15% sand
%sand > %gravel%sand < %gravel<15% gravel>15% gravel<15% sand
>15% sand
%sand > %gravel
%sand < %gravel
<15% gravel>15% gravel<15% sand>15% sand
fines=ML or MH
fines=CL or CH (or CL-ML)
fines=ML or MH
fines=CL or CH (or CL-ML)
fines=ML or MH
fines=CL or CH
fines=CL-ML
fines=ML or MH
fines=CL or CH
(or CL-ML)
fines=ML or MH
fines=CL or CH
(or CL-ML)
fines= ML or MH
fines=CL or CH
fines=CL-ML
<30% plus No. 200
>30% plus No. 200
<30% plus No. 200
>30% plus No. 200
<30% plus No. 200
>30% plus No. 200
<30% plus No. 200
>30% plus No.200
<30% plus No. 200
>30% plus No. 200
Cu>4 and 1<Cc<3
Cu<4 and/or 1>Cc>3
Cu>4 and 1<Cc<3
Cu<4 and/or 1>Cc>3
Cu>6 and 1<Cc<3
Cu<6 and/or 1>Cc>3
Cu>6 and 1<Cc<3
Cu<6 and/or 1>Cc>3
CL
CL-ML
ML
CH
MH
PI>7 and plotson or above"A" - line
4<PI<7 andplots on or above"A" - line
PI<4 or plotsbelow "A" - line
PI plots on orabove "A" - line
PI plots below"A" - line
GRAVEL%gravel >
%sand
SAND%sand >%gravel
LL>50(inorganic)
LL<50(inorganic)
GW
GP
GW-GM
GW-GC
GP-GM
GP-GC
GM
GC
GC-GM
SW
SP
SW-SM
SW-SC
SP-SM
SP-SC
SM
SC
SC-SM
<15% plus No. 20015-29% plus No. 200
%sand > %gravel
%sand < %gravel
<15% plus No. 200
15-29% plus No. 200
%sand > %gravel
%sand < %gravel
<15% plus No. 200
15-29% plus No. 200
%sand > %gravel
%sand < %gravel
<15% plus No. 20015-29% plus No. 200
%sand > %gravel
%sand < %gravel
<15% plus No. 20015-29% plus No. 200
%sand > %gravel
%sand < %gravel