HomeMy WebLinkAbout019 Geotechnical ReportMONTANA | WASHINGTON | IDAHO | NORTH DAKOTA | PENNSYLVANIA
JOB NO. B22-025 MAY 2022
REPORT OF GEOTECHNICAL INVESTIGATION
CLIENT ENGINEER
REUTER WALTON DEVELOPMENT
4450 Excelsior Blvd, Ste 400
St. Louis Park, MN 55416
Ahren Hastings, PE
ahren.hastings@tdhengineering.com
REPORT OF GEOTECHNICAL INVESTIGATION
PROJECT NAME
PROJECT LOCATION 406.586.0277
tdhengineeri ng.com
234 E. Babcock, Suite 3
Bozeman, MT 59715
1825 KAGY BOULEVARD DEVELOPMENT
BOZEMAN, MONTANA
1825 Kagy Boulevard Development Appendix
Bozeman, Montana ii
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 Conventional Shallow Foundations ............................................................................ 6
4.4 Foundation and Retaining Walls ................................................................................. 7
4.5 Floor Slabs and Exterior Flatwork ............................................................................... 7
4.6 Pavements ...................................................................................................................... 7
5.0 RECOMMENDATIONS ....................................................................................................... 9
5.1 Site Grading and Excavations ..................................................................................... 9
5.2 Conventional Shallow Foundations .......................................................................... 10
5.3 Foundation and Retaining Walls ............................................................................... 11
5.4 Floor Slabs and Exterior Flatwork ............................................................................. 13
5.5 Flexible Asphalt Pavements ...................................................................................... 13
5.6 Continuing Services .................................................................................................... 15
6.0 SUMMARY OF FIELD AND LABORATORY STUDIES ............................................... 17
6.1 Field Explorations ........................................................................................................ 17
6.2 Laboratory Testing ...................................................................................................... 17
7.0 LIMITATIONS ..................................................................................................................... 19
1825 Kagy Boulevard Development Appendix
Bozeman, Montana iii
APPENDIX
Test Pit Location Map (Figure 1)
Summary of Test Pits (Figure 2 through 7)
Laboratory Test Data (Figures 8 through 17)
Construction Standard 02801-06C
Soil Classification and Sampling Terminology for Engineering Purposes
Classification of Soils for Engineering Purposes
1825 Kagy Boulevard Development Executive Summary
Bozeman, Montana Page 1
GEOTECHNICAL REPORT
1825 KAGY DEVELOPMENT
BOZEMAN, MONTANA
1.0 EXECUTIVE SUMMARY
The proposed 1825 Kagy Boulevard Development project is located at the northeast corner of the
intersection of 19th Avenue and Kagy Boulevard in Bozeman, Montana. The geotechnical
investigation performed for this project showed 3.8 to 6.5 feet of surficial lean clay including 1.4 to
2.5 feet of topsoil with high organic content. The surficial clay is underlain by dense native gravels
classified as poorly-graded gravel with sand. The seismic site class is D, and the risk of seismically-
induced liquefaction or soil settlement is considered low and does not warrant additional evaluation.
The primary geotechnical concerns regarding this project are the presence of varying thicknesses
of compressible clay soils and potential ground water impacts during construction. The surficial clay
is not suitable to support foundation loads for the planned construction and should be removed and
replaced with properly compacted structural fill to minimize settlement. Due to the limited thickness
of the clay, significant volumes of structural fill are not anticipated beneath foundations, but this will
ultimately depend on the finished floor elevation and site grading. Ground water was not
encountered in the test pits performed for this project; however, the project is located in an area of
known high ground water. We do not anticipate significant long-term impacts of ground water with
the at-grade slab-on-grade construction; however, if below grade spaces are planned, seasonal
fluctuations could result in some impact during construction and long-term buoyant forces on below-
grade structures. During our field work, two monitoring wells were installed for your use in
monitoring fluctuations in the ground water elevation during seasonally wet periods of the year to
evaluate potential fluctuations. The well locations are shown on Figure 1.
Interior at-grade slab systems which utilize conventional construction methods would be underlain
by varying thickness of the surficial lean clay and could realize some differential movement as a
result. Due to the limited thickness of the clay material, its complete removal and replacement with
properly compacted structural fill within building footprints is recommended for this project to
mitigate any potential concerns with slab displacement.
The site is suitable for the use of conventional shallow foundation systems and interior slab-on-
grade construction bearing on properly compacted native gravel or compacted structural fill
extending to native gravel.
NXW Apartments Introduction
Bozeman, Montana Page 2
2.0 INTRODUCTION
2.1 Purpose and Scope
This report presents the results of our geotechnical study for the planned 1825 Kagy Boulevard
Development to be located at the northeast corner of the intersection of 19th Avenue and Kagy
Boulevard 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 structures 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 excavating six test pits across the proposed site. Samples were obtained
from various test pits 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.
This study is in accordance with the proposal submitted by Mr. Kyle Scarr, PE of our firm dated April
15, 2022. Our work was authorized to proceed by Reuter Walton Development by their signed
acceptance of our proposal.
2.2 Project Description
It is our understanding that the proposed project consists of multiple three to four story, wood-
framed apartment buildings, site parking, access roads, and landscaping. All structures are
anticipated to utilize conventional shallow foundation systems and interior slab-on-grade
construction. It is possible that below grade construction will be utilized depending on ground water
levels. 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 4,500 pounds per lineal foot and
column loads, if any, will be less than 100 kips.
Site development will most likely include landscaping, exterior concrete flatwork, and asphalt
pavement for parking lots and roads. If the assumed design values presented above vary from the
actual project parameters, the recommendations presented in this report should be reevaluated.
1825 Kagy Boulevard Development Site Conditions
Bozeman, Montana Page 3
3.0 SITE CONDITIONS
3.1 Geology and Physiography
The site is geologically characterized as containing gravel deposits which range from pebble to
boulder size and include sand, silt, and clay. These deposits are generally alluvial terrace,
abandoned channel and floodplain, remnant alluvial fan, and local glacial outwash. The gravel is
predominately subrounded to subangular and reportedly extends down to as much as 165 feet.
Upper tertiary sediments or sedimentary rock (Tsu) also frequent the Bozeman area according to
the Montana Bureau of Mines and Geology (MBMG), Geologic Map of Montana. These formations
consist of conglomerate, tuffaceous sandstone and siltstone, marlstone, and equivalent sediment
and ash beds.
Figure 1. Geologic Map of Bozeman Area (MBMG 2007)
Based on the subsurface conditions encountered and our experience in the area, 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 in use at the time of design. The likelihood of seismically-induced soil
liquefaction is low and does not warrant additional evaluation.
3.2 Surface Conditions
The proposed project site is located at the northeast corner of the intersection of 19th Avenue and
Kagy Boulevard in Bozeman, Montana. The site currently consists of a church, parking lot, and sod
landscaping. Based on background information and site observations, the project area is
considered generally flat.
Approximate
Site Location
1825 Kagy Boulevard Development Site Conditions
Bozeman, Montana Page 4
3.3 Subsurface Conditions
3.3.1 Soils
The subsurface soil conditions appear to be relatively consistent based on our exploratory
excavating and soil sampling. In general, the subsurface soil conditions encountered within
the test pits consist of approximately 3.8 to 6.5 feet of surficial lean clay and topsoil materials
overlying native gravel. The gravels extend to depths of at least 11.1 feet, the maximum
depth investigated.
The subsurface soils are summarized on the enclosed summary of test pits logs and 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.
LEAN CLAY
Lean clay was encountered in each of the test pits performed and extended to depths of 3.8
to 6.5 feet below existing site grades. The lean clay appears firm based on the ease of
excavation with the equipment utilized. Three samples of the material obtained from the test
pits exhibited the following gradations:
4.9 percent gravel, 7.3 percent sand, and 87.8 percent fines (clay and silt)
3.1 percent gravel, 26.0 percent sand, and 70.9 percent fines (clay and silt)
0.1 percent gravel, 4.4 percent sand, and 95.5 percent fines (clay and silt)
Four samples exhibited the following Atterberg Limits:
Liquid limit of 34 percent and a plasticity index of 14 percent
Liquid limit of 35 percent and a plasticity index of 15 percent
Liquid limit of 43 percent and a plasticity index of 23 percent
Liquid limit of 32 percent and a plasticity index of 12 percent
The natural moisture contents varied from 10.0 to 25.4 percent and averaged 19.1 percent.
A single proctor test was performed on a bulk sample of the native clay obtained from TP-2
using methods outlined in ASTM D698. This test resulted in a maximum dry density of 106.8
pounds per cubic foot (pcf) when compacted at the optimum moisture content of 17.5
percent.
POORLY-GRADED GRAVEL WITH SAND
Native poorly-graded gravel with sand was encountered in all six test pits at depths ranging
from 3.8 to 6.5 feet below existing grade and extending to depths of at least 11.1 feet, the
maximum depth investigated. The native gravel is considered relatively dense based on the
difficulty with excavation. A single bulk sample of the material contained 16.8 percent
cobbles (larger than 3-inch), 57.9 percent gravel, 23.4 percent sand, and 1.9 percent fines
(clay and silt). The same sample when tested in accordance with ASTM D4253 and D4254
1825 Kagy Boulevard Development Site Conditions
Bozeman, Montana Page 5
(Relative Density Test), resulted in a maximum dry density of 131.1 pcf at an optimum
moisture content of 7.8 percent.
3.3.2 Ground Water
Ground water was not encountered in the test pits. Two monitoring wells were installed in
TP-1 and TP-4 by placing a 10-foot-long stick of perforated 4-inch diameter SDR-35 pipe
into the open excavation and backfilling around it with the native gravels. These monitoring
locations are intended to be utilized to evaluate seasonal fluctuations in the ground water
levels up until the start of construction. At the time of this report, ground water was not
observed in the monitoring wells. This area is known for high ground water and 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.
1825 Kagy Boulevard Development Engineering Analysis
Bozeman, Montana Page 6
4.0 ENGINEERING ANALYSIS
4.1 Introduction
The primary geotechnical concern regarding this project is the presence of varying thicknesses of
compressible clay soils. Due to the variability of the clay thickness across site and the potential for
differential settlements, it is our opinion that the native clays are not suitable to support foundation
loads and that all foundations should extend down to native gravel or be supported by compacted
structural fill extending to native gravel. Similar improvements are recommended for interior slab
systems to minimize settlement concerns and improve slab performance.
We do not anticipate significant long-term impacts of ground water with the assumed at-grade slab-
on-grade construction; however, seasonal fluctuations could result in some impact during
construction and long-term buoyant forces on below grade structures if utilized.
4.2 Site Grading and Excavations
The ground surface at the proposed site is considered nearly level. Based on our field work, limited
amounts of surficial lean clay overlying native gravels are anticipated in footing and utility
excavations to the depths anticipated for this project. Based on the test pits, ground water was not
observed to a maximum depth of 11.1 feet below existing grade. However, seasonal fluctuations
have not been evaluated for the site and may result in ground water being encountered at shallower
depths. The contractor should be prepared to dewater any footing and utility excavations should
they encounter ground water. Additionally, future monitoring of ground water levels should be
performed to determine the magnitude of seasonal fluctuations and assess if buoyant forces need to
be considered in the design of below grade structures if utilized.
4.3 Conventional Shallow Foundations
Considering the subsurface conditions encountered and the nature of the proposed construction,
the structures can be supported on conventional concrete footings bearing on properly compacted
native gravel or compacted structural fill extending to compacted native gravel. Significant
thicknesses of structural fill beneath foundations are not anticipated for this project; however, this
will ultimately depend on the finished floor elevation and site grading.
Based on our experience, the theory of elasticity, and using an allowable bearing pressure of 4,000
psf, we estimate the total settlement for footings will be less than ¾-inch. Differential settlement
within the limits of each individual structure should be on the order of one-half this magnitude.
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.
1825 Kagy Boulevard Development Engineering Analysis
Bozeman, Montana Page 7
4.4 Foundation and Retaining Walls
Foundation walls which will retain differential soil heights are only anticipated for below grade
structures should they be used. These structures 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.
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, exclusive of topsoil, are suitable to support lightly to moderately loaded,
exterior concrete flatwork. The native lean clay is considered frost susceptible, compressible, and
prone to strength loss when wetted. For these reasons, some risk of vertical movement beneath
exterior concrete flatwork should be expected for this project.
Interior slab systems for structures are more susceptible to damages resulting from slab movements
and are extremely difficult and expensive to repair. For these reasons, we recommend that the
native clay be removed from beneath the interior slabs systems down to the native gravel contact.
This zone should be replaced with compacted structural fill to improve performance of the interior
slab and control potential slab displacements. Slab-on-grade construction overlying compacted
structural fill extending down to the native gravel is not anticipated to realize vertical movements
exceeding ½-inch.
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
1825 Kagy Boulevard Development Engineering Analysis
Bozeman, Montana Page 8
that traffic for the parking lots and access roads will be limited to passenger-type vehicles with very
low equivalent single axle loads (ESALs). The pavement sections specified for these areas are the
minimum sections recommended for general constructability and exposure of the pavement over a
design life of 20 years.
The potential worst-case subgrade material is native lean clay which is classified as an A-6 and A-7
soil in accordance with the American Association of State Highway and Transportation Officials
(AASHTO) classification depending on the soil plasticity. AASHTO considers these soil types to be
a relatively poor subgrade due to its frost susceptibility, poor drainage properties, and low strength.
Typical California Bearing Ratio (CBR) values for this type of soil range from 5 to 15 percent when
properly compacted. Preliminary moistures appear sufficiently low to assume that compaction of the
subgrade strata will be feasible during construction. However, our experience in the area is that
spring runoff and snow melt typically results in a significant spike in soil moisture and can preclude
proper compaction. Thus, depending on the construction schedule, compaction of the pavement
subgrade may or may not be feasible. We have included recommendations for modified pavement
sections it subgrade soils are too wet to facilitate subgrade compaction at the time of construction.
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 and the loss of
aggregate into the subgrade, thereby prolonging the structural integrity and performance of the
pavement section.
The pavement sections presented in this report is based on an assumed CBR value of four percent
for properly compacted subgrade and two percent for subgrade which cannot be compacted due to
moisture at the time of construction. Additionally, our recommendations are based on assumed
traffic loadings, 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.
1825 Kagy Boulevard Development Recommendations
Bozeman, Montana Page 9
5.0 RECOMMENDATIONS
5.1 Site Grading and Excavations
1. All topsoil and organic material 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, exclusive of
topsoil, are suitable for use as exterior foundation backfill and general site grading fill
provided they are moisture conditioned and conducive to adequate levels of
compaction.
3. 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 optimum (within
approximately three percent) 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) Below Foundations or Spread Footings ...................................... 98%
b) Below Interior Slab-on-Grade Construction ................................. 98%
c) Exterior Foundation Wall Backfill & Exterior Flatwork ................. 95%
d) Below Parking Lots or Other Paved Areas .................................. 95%
e) General Landscaping or Nonstructural Areas ............................. 92%
f) Utility Trench Backfill, To Within 2 Feet of Surface ...................... 95%
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. Imported structural fill should be non-expansive, free of organics and debris, and
conform to the material requirements outlined in Section 02234, Subsections 2.3 and
2.4 of the Montana Public Works Standard Specifications (MPWSS). All gradations
outlined in this standard are acceptable for use on this project based on local
availability and contractor preference. Native gravels, when available from other
excavations, are considered suitable for use as structural fill but may require
processing to remove rocks larger than 4-inch prior to use.
1825 Kagy Boulevard Development Recommendations
Bozeman, Montana Page 10
Conventional proctor methods (outlined in ASTM D698) shall not be used for any
materials containing less than 70 percent passing the ¾-inch sieve. Conventional
proctor methods are not suitable for these types of materials, and the field
compaction value must be determined using a relative density test outlined in ASTM
D4253-4254.
5. 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
final site grading shall conform to the grading plan, prepared by others to satisfy the
minimum requirements of the applicable building codes.
6. We recommend that all roof downspouts be directed to the on-site storm water
systems, when possible. However, 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.
7. 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 soil conditions on site can change due
to changes in soils moisture or disturbances to the site prior to construction. Thus,
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
The design and construction criteria below should be observed for a conventional shallow
foundation system. The construction details should be considered when preparing the project
documents.
8. Both interior and exterior footings should bear on properly compacted native gravels
or compacted structural fill (Item 4) extending down to compacted native gravel.
Prior to the placement of structural fill or concrete forms, the surface of the native
gravels should be compacted and field verified to a minimum depth of 6 inches.
Footings supported as described above should be designed for a maximum
allowable soil bearing pressure of 4,000 psf provided settlements as outlined in the
1825 Kagy Boulevard Development Recommendations
Bozeman, Montana Page 11
Engineering Analysis are acceptable. A one-third increase in the allowable bearing
pressure is permitted for the consideration of dynamic load cases.
Based on the test pits performed, the need for structural fill beneath building
foundations will vary and will be partially controlled by the finished floor elevation
selected for each structure. The limits of over-excavation and replacement with
compacted structural fill should extend at least 18 inches beyond the outer face of
the footings in all directions.
9. Soils disturbed below the planned depths of footing excavations should either be re-
compacted or be replaced with suitable compacted backfill approved by the
geotechnical engineer.
10. Footings shall be sized to satisfy the minimum requirements of the applicable
building codes while not exceeding the maximum allowable bearing pressure
provided in Item 8 above.
11. Exterior footings and footings beneath unheated areas should be placed at least 48
inches below finished exterior grade for frost protection.
12. The bottom of the footing excavations should be free of cobbles and boulders to
avoid stress concentrations acting on the base of the footings. In areas where
footings are supported directly on native gravels and the surface cannot be rolled
smooth due to cobbles and boulders, a thin layer of cushion gravel should be
installed between the native gravel and the footing. Cushion gravel materials should
consist of finer graded structural fill material, conforming to Item 4 above, which is
placed and compacted per Item 3a.
13. 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 0.45 and a lateral resistance pressure of
150 psf per foot of depth are appropriate for footings bearing on compacted gravel or
structural fill and backfilled with properly compacted native soils.
14. A representative of the project geotechnical engineer should be retained to observe
all footing excavations and backfill phases prior to the placement of concrete
formwork in order to verify the removal of all clay soil and the proper compaction of
all structural fill and bearing gravel strata.
5.3 Foundation and Retaining Walls
The design and construction criteria presented below should be observed for foundation and
retaining walls. The construction details should be considered when preparing the project
documents.
1825 Kagy Boulevard Development Recommendations
Bozeman, Montana Page 12
15. If utilized, below grade walls for the structures should be designed using at-rest earth
pressures to limit lateral deflection of the wall structure. An at-rest lateral earth
pressure computed on the basis of an equivalent fluid unit weight of 60 pcf is
appropriate for backfill consisting of structural fill or native gravels. We recommend
that gravel backfill be utilized for a distance behind the wall equal to its height.
16. Site grading retaining structures which can deflect sufficiently to mobilize the full
active earth pressure condition, approximately three percent of the exposed wall
height, may be designed for a lateral earth pressure computed on the basis of an
equivalent fluid unit weight of 60 pcf for backfill consisting of compacted lean clay.
When structural fill or native gravels are to be utilized as backfill, a reduced active
earth pressure of 30 pcf is appropriate.
17. Backfill should be selected, placed, and compacted per Items 2 and 3 above. Care
should be taken not to over-compact the backfill since this could cause excessive
lateral pressure on the walls. Only hand-operated compaction equipment should be
used within 5 feet of retaining and foundation walls. Backfilled placed adjacent to
foundation walls for slab-on-grade structures should utilize lifts of equal thickness
which alternate between the interior and exterior of the structure.
18. Future monitoring of installed wells on site should be performed during upcoming
spring and summer months to evaluate fluctuations in the ground water table.
Monthly readings are recommended to ensure that the peak time frame is measured.
If monitoring indicates that ground water may rise above the elevation of the planned
basements, either an adequate drain system shall be designed by others to maintain
a water level below the bottom of basement elevation or the structure shall be
designed to resist the buoyant forces and lateral forces on pool walls associated with
the maximum anticipated ground water elevation.
19. Exterior footing drains are required by applicable building codes for all portions of the
structure in which the finished exterior grade is higher than the finished floor
elevation of the lowest level. 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 the site storm water system, an
interior sump, or point of surface discharge away from the foundation. A typical
perimeter foundation drain is shown on Construction Standard No. 02801-06C.
1825 Kagy Boulevard Development Recommendations
Bozeman, Montana Page 13
5.4 Floor Slabs and Exterior Flatwork
20. 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 any frost heave or
settlement concerns associated with the subsurface conditions encountered.
21. Interior slab-on-grade construction is more susceptible to slab displacements which
can cause interior distress and are very expensive to repair. For these reasons, we
recommend that these slabs be underlain by structural fill extending to the native
gravel to improve long-term performance.
Similar construction should be considered beneath any exterior slabs that would be
adversely impacted by differential slab movements, such as potential exterior
breezeways with stair access.
22. Concrete floor slabs should be designed using a modulus of vertical subgrade
reaction no greater than 350 pci when designed and constructed as recommended
above.
23. Geotechnically, an underslab vapor barrier is not required for the anticipated at-
grade slab systems planned 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 Flexible Asphalt Pavements
24. The following pavement sections or an approved equivalent section should be
selected in accordance with the discussions in the Engineering Analysis depending
on the subgrade conditions at the time of construction.
1825 Kagy Boulevard Development Recommendations
Bozeman, Montana Page 14
Pavement Sections for Properly Compacted, Stable Subgrade
Pavement Component Component
Thickness
Asphaltic Concrete Pavement 3”
Crushed Base Course 6”
Crushed Subbase Course 12”
Total 21”
The pavement section provided above assumes that the subgrade at the time of
construction will be sufficiently dry to facilitate proper compaction to the requirements
of Item 3d without instability or pumping. If subgrade moistures are elevated and the
subgrade cannot be compacted to the requirements of Item 3d or the subgrade is
unstable, the pavement section should be modified as outlined below to account for
the weaker subgrade.
Pavement Section for Unstable or Non-compactable Subgrade
Pavement Component Component
Thickness
Asphaltic Concrete Pavement 3”
Crushed Base Course 6”
Crushed Subbase Course 20”
Total 29”
25. Final pavement thicknesses exceeding 3 inches shall be constructed in two uniform
lifts.
26. 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.
27. 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 Items 2 and 3 above.
1825 Kagy Boulevard Development Recommendations
Bozeman, Montana Page 15
28. 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 appropriate.
29. 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% 33.9 -30.6 PG 52-34
98% 37.6 -39.5 PG 52-40
For most low volume parking lot applications, a 50 percent reliability is considered
sufficient. The table above outlines the ideal bituminous products for the local
climate conditions in Bozeman, Montana; however, in our experience neither of
these types of oil are commonly utilized or available through local contractors. While
the use of these oil types should improve performance, they will also increase
construction expenses associated with importing the specialized product and the use
of similar high-quality or modified asphalt products. Based on our experience, the
use of a PG 58-28 is recommended for this project. This material is frequently
utilized in Bozeman and has demonstrated acceptable performance levels for this
region.
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
1825 Kagy Boulevard Development Recommendations
Bozeman, Montana Page 16
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 1 Test per Footing per Lift
Beneath Wall Footings 1 Test per 50 LF of Wall per Lift
Beneath Slabs 1 Test per 1,000 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
Concrete Testing**
Structural Concrete† 1 Test per 50 CY per Day
Non-Structural Concrete 1 Test per 100 CY per Day (MPWSS Requirement)
** The testing frequencies shown are considered typical frequencies utilized for similar projects in the
region; however, frequencies specified by the civil / structural designer of record shall govern.
† Structural concrete includes all footings, stem walls, slabs, and other load bearing elements
CY = Cubic Yards
1825 Kagy Boulevard Development Summary of Field & Laboratory Studies
Bozeman, Montana Page 17
6.0 SUMMARY OF FIELD AND LABORATORY STUDIES
6.1 Field Explorations
The field exploration program was conducted on April 21, 2022. A total of six test pits were
excavated to depths ranging from 9.2 to 11.1 feet at the approximate locations shown on Figure 1 to
observe subsurface soil and ground water conditions. The tests pits were excavated by Earth
Surgeons using a CAT 305CR excavator. The test pits were logged by Mr. Ahren Hastings, PE of
TD&H Engineering. The location of the test pits was determined based on the site plan provided for
our use and were staked by TD&H survey personnel prior to the field investigation.
Composite grab samples of the excavation spoils were collected periodically during excavation and
at distinct changes in soil strata. A summary of the subsurface soils and ground water conditions
encountered in each test pit is shown on the test pit logs.
Ground water was not encountered in the test pits performed to a maximum depth of 11.1 feet below
existing site grades. Two monitoring wells were constructed at the corners of the property by
installing a 10-foot long perforated SDR-35 pipe in the open test pit and backfilling with native
gravels. No additional monitoring of these wells has been performed at the time of this report.
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.
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
or Relative Density Curve.
1825 Kagy Boulevard Development Summary of Field & Laboratory Studies
Bozeman, Montana Page 18
The laboratory testing program for this project consisted of 12 moisture-visual analyses, 4 sieve
(grain-size distribution) analysis, and 4 Atterberg Limits analyses. In addition, a single relative
density test and one standard proctor test were performed on representative bulk samples of the
native materials. The results of the laboratory testing are shown on Figures 8 through 17.
1825 Kagy Boulevard 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 test pits 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 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 test pits 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. We strongly advise that TD&H
be retained 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. 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
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
1825 Kagy Boulevard Development Limitations
Bozeman, Montana Page 20
contractor for information on factual data only and not as a warranty of subsurface conditions such
as those interpreted from the test pit logs and presented in discussions of subsurface conditions
included in this report.
Prepared by: Reviewed by:
Ahren Hastings PE Kyle Scarr PE
Geotechnical Engineer Regional Manager
TD&H ENGINEERING TD&H ENGINEERING
SHEETREVISIONSHEETDESIGNED BY:QUALITY CHECK:JOB NO.FIELDBOOKDRAWN BY:DATE:B22-025 FIG 1REV DATE NOT FORCONSTRUCTION
1825 KAGY BOULEVARD DEVELOPMENT
BOZEMAN, MONTANA
GEOTECHNICAL INVESTIGATION
TEST PIT LOCATIONS B22-0252022.05.13.DWGFIG. 1TRB-ACHEngineering
234 E. BABCOCK ST., SUITE 3 • BOZEMAN, MONTANA 59715
406.586.0277 • tdhengineering.com
Log of Test Pit TP-1
Figure No.
Sheet of
2
1 1LOGGRAPHIC01020304050
0
0 10 30 40 5020SAMPLEDEPTHWATERGROUNDSOIL DESCRIPTION
LEGEND DEPTH(FEET)1825 Kagy Boulevard Development
Geotechnical Investigation
THOMAS, DEAN & HOSKINS, INC.
ENGINEERING CONSULTANTS
April 21, 2022 B22-025(FEET)1
8
12
APPROXIMATE SURFACE ELEVATION:
SURFACE:
Logged By: Ahren Hastings, P.E.Excavated By:Earth Surgeons
CAT 305 CR
4
6
10
14
16
CLAY
2
3
5
7
9
11
13
15
CLAY
GRAVEL
Bottom of Test Pit
Groundwater Not EncounteredDuring Excavation
Log of Test Pit TP-2
Figure No.
Sheet of
3
1 1LOGGRAPHIC01020304050
0
0 10 30 40 5020SAMPLEDEPTHWATERGROUNDSOIL DESCRIPTION
LEGEND DEPTH(FEET)1825 Kagy Boulevard Development
Geotechnical Investigation
THOMAS, DEAN & HOSKINS, INC.
ENGINEERING CONSULTANTS
April 21, 2022 B22-025(FEET)1
8
12
APPROXIMATE SURFACE ELEVATION:
SURFACE:
Logged By: Ahren Hastings, P.E.Excavated By:Earth Surgeons
CAT 305 CR
4
6
10
14
16
CLAY
2
3
5
7
9
11
13
15
CLAY
GRAVEL
Bottom of Test Pit
Groundwater Not EncounteredDuring Excavation
Log of Test Pit TP-3
Figure No.
Sheet of
4
1 1LOGGRAPHIC01020304050
0
0 10 30 40 5020SAMPLEDEPTHWATERGROUNDSOIL DESCRIPTION
LEGEND DEPTH(FEET)1825 Kagy Boulevard Development
Geotechnical Investigation
THOMAS, DEAN & HOSKINS, INC.
ENGINEERING CONSULTANTS
April 21, 2022 B22-025(FEET)1
8
12
APPROXIMATE SURFACE ELEVATION:
SURFACE:
Logged By: Ahren Hastings, P.E.Excavated By:Earth Surgeons
CAT 305 CR
4
6
10
14
16
CLAY
2
3
5
7
9
11
13
15
CLAY
GRAVEL
Bottom of Test Pit
Groundwater Not EncounteredDuring Excavation
Log of Test Pit TP-4
Figure No.
Sheet of
5
1 1LOGGRAPHIC01020304050
0
0 10 30 40 5020SAMPLEDEPTHWATERGROUNDSOIL DESCRIPTION
LEGEND DEPTH(FEET)1825 Kagy Boulevard Development
Geotechnical Investigation
THOMAS, DEAN & HOSKINS, INC.
ENGINEERING CONSULTANTS
April 21, 2022 B22-025(FEET)1
8
12
APPROXIMATE SURFACE ELEVATION:
SURFACE:
Logged By: Ahren Hastings, P.E.Excavated By:Earth Surgeons
CAT 305 CR
4
6
10
14
16
CLAY
2
3
5
7
9
11
13
15
CLAY
GRAVEL
Bottom of Test Pit
Groundwater Not EncounteredDuring Excavation
Log of Test Pit TP-5
Figure No.
Sheet of
6
1 1LOGGRAPHIC01020304050
0
0 10 30 40 5020SAMPLEDEPTHWATERGROUNDSOIL DESCRIPTION
LEGEND DEPTH(FEET)1825 Kagy Boulevard Development
Geotechnical Investigation
THOMAS, DEAN & HOSKINS, INC.
ENGINEERING CONSULTANTS
April 21, 2022 B22-025(FEET)1
8
12
APPROXIMATE SURFACE ELEVATION:
SURFACE:
Logged By: Ahren Hastings, P.E.Excavated By:Earth Surgeons
CAT 305 CR
4
6
10
14
16
CLAY
2
3
5
7
9
11
13
15
CLAY
GRAVEL
Bottom of Test Pit
Groundwater Not EncounteredDuring Excavation
Log of Test Pit TP-6
Figure No.
Sheet of
7
1 1LOGGRAPHIC01020304050
0
0 10 30 40 5020SAMPLEDEPTHWATERGROUNDSOIL DESCRIPTION
LEGEND DEPTH(FEET)1825 Kagy Boulevard Development
Geotechnical Investigation
THOMAS, DEAN & HOSKINS, INC.
ENGINEERING CONSULTANTS
April 21, 2022 B22-025(FEET)1
8
12
APPROXIMATE SURFACE ELEVATION:
SURFACE:
Logged By: Ahren Hastings, P.E.Excavated By:Earth Surgeons
CAT 305 CR
4
6
10
14
16
CLAY
2
3
5
7
9
11
13
15
CLAY
GRAVEL
Bottom of Test Pit
Groundwater Not EncounteredDuring Excavation
Tested By: WJC Checked By:
4-29-2022
8
(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
98.0
96.6
95.9
95.5
95.1
94.7
94.3
93.7
93.0
92.2
91.5
87.8
20 35 15
0.1107
CL A-6(13)
Report No. A-25268-206
Reuter Walton Development
1825 West Kagy Development
Bozeman, Montana
B22-025-001
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: TP-2
Sample Number: A-25268 Depth: 3.0 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 3.4 1.5 0.4 1.0 5.9 87.86 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: WJC Checked By:
4-29-2022
9
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Poorly-Graded GRAVEL with Sand
6"
3"
2"
1.5"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
83.2
72.7
63.8
49.9
43.4
35.5
31.8
25.3
20.3
14.1
7.3
4.4
3.2
2.7
1.9
100.7563 82.0417 34.2518
25.4534 8.0212 0.9337
0.5697 60.13 3.30
GP
Report No. A-25269-206
Reuter Walton Development
1825 West Kagy Development
Bozeman, Montana
B22-025-001
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: TP-2
Sample Number: A-25269 Depth: 6.0 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
16.8 39.8 18.1 5.0 13.0 5.4 1.96 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:
4-29-2022
10
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Lean CLAY with Sand
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
97.5
97.5
96.9
96.0
94.9
93.3
91.1
87.6
84.1
70.9
0.2178 0.1568
CL
Report No. A-25271-206
Reuter Walton Development
1825 West Kagy Development
Bozeman, Montana
B22-025-001
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: TP-3
Sample Number: A-25271 Depth: 4.0 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 3.1 0.9 2.7 22.4 70.96 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:
4-29-2022
11
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Lean CLAY
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
99.9
99.8
99.5
98.9
98.4
98.0
97.7
95.5
CL
Report No. A-25273-206
Reuter Walton Development
1825 West Kagy Development
Bozeman, Montana
B22-025-001
Soil Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: TP-4
Sample Number: A-25273 Depth: 2.0 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 0.1 0.1 0.9 3.4 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 CONTENT32.4
32.8
33.2
33.6
34
34.4
34.8
35.2
35.6
36
36.4
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: TP-1
Sample Number: A-25266 Depth: 4.0 ft
Figure
Lean CLAY with Sand 34 20 14 CL
B22-025- Reuter Walton Development
12
Report No. A-25266-207
Date: 4-29-20221825 West Kagy Development
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 CONTENT33.6
34
34.4
34.8
35.2
35.6
36
36.4
36.8
37.2
37.6
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-2
Sample Number: A-25268 Depth: 3.0 ft
Figure
Lean CLAY 35 20 15 93.7 87.8 CL
B22-025- Reuter Walton Development
13
Report No. A-25268-207
Date: 4-29-20221825 West Kagy Development
Bozeman, Montana
Tested By: BS 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 CONTENT42.3
42.5
42.7
42.9
43.1
43.3
43.5
43.7
43.9
44.1
44.3
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-5
Sample Number: A-25276 Depth: 2.0 ft
Figure
Lean CLAY 43 20 23 CL
B22-025- Reuter Walton Development
14
Report No. A-25276-207
Date: 4-29-20221825 West Kagy Development
Bozeman, Montana
Tested By: BS 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 CONTENT28
29
30
31
32
33
34
35
36
37
38
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-6
Sample Number: A-25280 Depth: 4.0 ft
Figure
Lean CLAY with Sand 32 20 12 CL
B22-025- Reuter Walton Development
15
Report No. A-25280-207
Date: 4-29-20221825 West Kagy Development
Bozeman, Montana
Tested By: BS Checked By:
Moisture-Density Test Report
Dry density, pcf92
97
102
107
112
117
Water content, %
5 10 15 20 25 30 35
17.5%, 106.8 pcf
ZAV for
Sp.G. =
2.65
Test specification:ASTM D 698-12 Method A Standard
3.0 ft CL A-6(13) 2.65 35 15 4.9 87.8
Lean CLAY
B22-025- Reuter Walton Development
Report No. A-25268-204
Date: 4-29-2022
16
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-2 Sample Number: A-25268
Figure
Maximum dry density = 106.8 pcf
Optimum moisture = 17.5 %
1825 West Kagy Development
Bozeman, Montana
Technician:
Test Procedure
2.65
16.8
1.9
FIGURE 17
WJC
Pessimum Moisture =3.0 % Passing No. 200
Poorly Graded GRAVEL w/ Sand
7.8
Specific Gravity
Unified Classification
Optimum Moisture =
Minimum Dry Density =
131.1
115.0
Maximum Dry Density =
Client:Reuter Walton Report Number:A-25269-209
Thomas, Dean & Hoskins, Inc.
Sample Source:TP-2 (6.0 ft)
REPORT OF RELATIVE DENSITY
1800 River Drive North
Great Falls, Montana 59401
Jacob Budenski
Report Date:5/6/2022
Telephone: (406) 761-3010 Fax: (406) 727-2872
Suite 400 Sample Number:A-25269
4450 Excelsior Blvd.Project Number:B22-025-001
Project:1825 W. Kagy Development
Development
St. Louis Park, MN Date Sample Received:5/1/2022
Attn:
Address:
Relative Density, (ASTM D-4253, ASTM D-4254, ASTM D-4718)
% Retained on 3"
Peter Klevberg, P.E.
Laboratory Manager
100.0
105.0
110.0
115.0
120.0
125.0
130.0
135.0
140.0
145.0
150.0
0.0 2.0 4.0 6.0 8.0 10.0Dry Density (pcf)Water Content (%)
100
110
120
130
140
150
0 10 20 30 40 50 60 70 80 90 100lbs. / cu.ft.Percent Relative Density
ZAV Curve
QUALITY CHECK:
DESIGNED BY:
DRAWN BY:
CAD NO.
JOB NO.
DATE:
02801-06C
Engineering
tdhengineering.com
CONSTRUCTION STANDARD NO. 02801-06C
PERIMETER FOUNDATION DRAIN
RESIDENTIAL CONSTRUCTION
RLT
CRN
MMJ
5/21/15
FIGURE
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
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)