HomeMy WebLinkAbout011 - Appendix J - Geotech ReportMONTANA | WASHINGTON | IDAHO | NORTH DAKOTA | PENNSYLVANIA
JOB NO. B23-012-001 May 2023
REPORT OF GEOTECHNICAL INVESTIGATION
CLIENT ENGINEER
Brick Capital RE
1907 Pine Street
Philadelphia, PA 19143
Kyle Scarr, PE
kyle.scarr@tdhengineering.com
REPORT OF GEOTECHNICAL INVESTIGATION
PROJECT NAME
PROJECT LOCATION 406.586.0277
tdhengineering.com
234 E Babcock St, Suite 3
Bozeman, MT 59715
805 NORTH IDA & 622 EAST TAMARACK
BOZEMAN, MONTANA
5/11/2023
805 North Ida & 622 East Tamarack Table of Contents
Bozeman, Montana i
Table of Contents
1.0 EXECUTIVE SUMMARY .................................................................................................... 1
2.0 INTRODUCTION .................................................................................................................. 3
2.1 Purpose and Scope ....................................................................................................... 3
2.2 Project Description ........................................................................................................ 3
3.0 SITE CONDITIONS .............................................................................................................. 5
3.1 Geology and Physiography .......................................................................................... 5
3.2 Surface Conditions ........................................................................................................ 6
3.3 Subsurface Conditions .................................................................................................. 7
3.3.1 Soils .......................................................................................................................... 7
3.3.2 Ground Water ......................................................................................................... 8
4.0 ENGINEERING ANALYSIS ............................................................................................... 9
4.1 Introduction ..................................................................................................................... 9
4.2 Site Grading and Excavations ..................................................................................... 9
4.3 Conventional Shallow Foundations .......................................................................... 10
4.4 Foundation and Retaining Walls ............................................................................... 10
4.5 Interior Slabs-on-Grade .............................................................................................. 11
4.6 Exterior Concrete Flatwork ........................................................................................ 11
4.7 Pavements .................................................................................................................... 11
5.0 RECOMMENDATIONS ..................................................................................................... 13
5.1 Site Grading and Excavations ................................................................................... 13
5.2 Conventional Shallow Foundations .......................................................................... 14
5.3 Foundation and Retaining Walls ............................................................................... 15
5.4 Interior Slabs-on-Grade .............................................................................................. 16
5.5 Exterior Concrete Flatwork ........................................................................................ 17
5.6 Pavements .................................................................................................................... 18
5.7 Continuing Services .................................................................................................... 20
6.0 SUMMARY OF FIELD AND LABORATORY STUDIES .............................................. 22
6.1 Field Explorations ........................................................................................................ 22
6.2 Laboratory Testing ...................................................................................................... 22
7.0 LIMITATIONS ..................................................................................................................... 24
805 North Ida & 622 East Tamarack Appendix
Bozeman, Montana ii
APPENDIX
Boring Location Map (Figure 1)
Logs of Exploratory Borings (Figures 2 through 6)
Laboratory Test Data (Figures 7 through 14)
LTTPBind Online PG Asphalt Binder Analysis Summary
Construction Standard 02801-06C
Soil Classification and Sampling Terminology for Engineering Purposes
Classification of Soils for Engineering Purposes
805 North Ida & 622 East Tamarack Executive Summary
Bozeman, Montana Page 1
GEOTECHNICAL REPORT
805 NORTH IDA & 622 EAST TAMARACK
BOZEMAN, MONTANA
1.0 EXECUTIVE SUMMARY
The geotechnical investigation for the Brick Capital Development to be located at 805 North Ida
Avenue and 622 East Tamarack Street in Bozeman, Montana, encountered relatively consistent soil
conditions. The subsurface soils are comprised of a limited thickness of native fat clay overlying
native gravels, visually classified as poorly-graded gravel with clay and sand. The native gravels
extend to depths of at least 26.0 feet, the maximum depth investigated. 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 concern regarding this project is the presence of relatively soft, potentially
compressible, and expansive clay soils. Such materials are not considered suitable to remain
beneath building foundations and interior slab systems and warrant removal and replacement with
properly compacted structural fill. These clay soils are acceptable to remain beneath exterior
parking lots and exterior flatwork provided some risk of vertical displacements is acceptable for
these elements and that they are properly designed in accordance with our recommendations,
which have considered such conditions.
Additionally, we understand that two existing structures currently occupy the lots and will be subject
to demolition and removal prior to construction. The existing foundations of the structures are
unknown; however, care should be taken to completely remove all building components and clay
soils from beneath these structures. The site is suitable for the use of conventional shallow
foundations and interior slab-on-grade construction bearing on properly compacted native gravels
or properly compacted structural fill extending to native gravel. A maximum allowable bearing
pressure of 5,000 pounds per square foot (psf) is suitable for this site provided the
recommendations included in this report are followed.
Recommendations for exterior parking lots have been prepared assuming that clay soils will remain
beneath the parking lot section. However, if preferred, the removal and replacement of the clay to
native gravel will improve long-term performance by supporting the pavement section on a far
superior subgrade material. Conventional construction of exterior flatwork, consisting of a thin base
course gravel layer over existing clay soils, has been recommended for this project assuming some
risk related to vertical movements can be tolerated in order to control the overall cost of constructing
these elements. If no level of risk is acceptable for exterior flatwork or for specific elements which
will be especially sensitive to vertical movements, the native clays should be completely removed
and replaced with compacted structural fill.
805 North Ida & 622 East Tamarack Executive Summary
Bozeman, Montana Page 2
To ensure proper performance of subsurface storm water systems they should extend to the
surface of the native gravel. The overlying clay soil is expected to have little or no permeability and
is not suitable for on-site infiltration.
805 North Ida & 622 East Tamarack Introduction
Bozeman, Montana Page 3
2.0 INTRODUCTION
2.1 Purpose and Scope
This report presents the results of our geotechnical study for the Brick Capital Development to be
located at 805 North Ida Avenue and 622 East Tamarack Street. 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.
The initial field investigation was performed on March 13th and 14th of 2023 and included drilling four
soil borings across the proposed site. Due to the time of year and the volume of snow in the area,
the final boring of the planned exploratory program could not be completed without causing
excessive disturbance to the site. Following seasonal snow melt and drier conditions, the final
boring was completed on April 25, 2023 using alternative drilling equipment. Samples from both
investigations were obtained from the borings 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 is comprised of two five-story structures, one on
each lot, consisting of residential units, common space, and leased commercial space. The
residential units are planned to be split into studios, and one-to-three-bedroom units. The common
and commercial space will consist of lobbies, storage / utility rooms, gym space, and shared offices.
Additionally, the development is planned to incorporate two three-story structures within the
southern lot, and one three-story structure within the northern lot. The first and second floor of
these structures will include two-story townhome units, while the third floor will consist of single-
story townhome units. The proposed development is currently planned to utilize below grade
parking beneath each lot; however, groundwater was encountered at relatively shallow depths and
may affect the design of such features. Further monitoring of the groundwater levels is currently in
progress through spring of 2023 to determine the feasibility of the planned below grade parking.
The structures are anticipated to utilize both wood and steel construction and be supported on
conventional shallow foundations incorporating slab-on-grade 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, if any, will
be less than 150 kips.
805 North Ida & 622 East Tamarack Introduction
Bozeman, Montana Page 4
Site development will most likely include landscaping, exterior concrete flatwork, possible asphalt
pavement for exterior parking lots, and subsurface retention systems. If the assumed design values
presented above vary from the actual project parameters, the recommendations presented in this
report should be reevaluated.
805 North Ida & 622 East Tamarack Site Conditions
Bozeman, Montana Page 5
3.0 SITE CONDITIONS
3.1 Geology and Physiography
The site is geologically characterized as gravel (Qgr) and alluvium (Qal). The gravel areas shown on
the geologic map below are generally comprised of variable deposits ranging from pebble to
boulder size including sand, silt, and clay. They are dominantly associated with alluvial terrace,
abandoned channel and floodplain, remnant alluvial fan, and local glacial outwash. The area shown
as white, is delineated as alluvium which is typically comprised of gravel, sand, silt, and clay
deposits of stream and river channels and floodplains. The sections denoted Tsu are Upper Tertiary
Sediments or sedimentary rock comprised of conglomerate, tuffaceous sandstone and siltstone,
marlstone, and equivalent sediment and ash beds. Based on the sites existing well log data, the
native gravels are anticipated to extend to depths of at least 30 feet; however, other nearby well
logs suggest these gravels may exceed to depths of 100 feet within areas of Bozeman.
Additional data provided by the geologic map of Bozeman further classifies the site as being
alluvium of the braid plain (Qab). These deposits consist of cobble to boulder size clasts containing
sand, silt, and clay. The rounded to well-rounded clasts are most commonly composed of Archean
metamorphic rock, and dark colored volcanic rock, with subordinate Paleozoic limestone and
Proterozoic Belt rocks. According to the geology report, two wells in this unit adjacent to the
Gallatin River indicate thicknesses of quaternary alluvium overlying tertiary deposits of 31 and 215
feet.
Geologic Map of Montana, Edition 1.0 (2007)
Montana Bureau of Mines & Geology
Approximate
Site Location
805 North Ida & 622 East Tamarack Site Conditions
Bozeman, Montana Page 6
Geologic Map of the Bozeman, Southwestern Montana (2014)
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 at 805 North Ida Avenue and 622 East Tamarack Street in
Bozeman, Montana. Both lots are heavily developed with nearly the entire properties consisting of
existing gravel surfacing, concrete flatwork, and buildings. A single-story structure being
approximately 1,700 square feet in plan is located in the northeast portion of 805 North Ida Avenue
and is currently occupied by an entertainment company. Similarly, 622 East Tamarack Street
contains a single-story warehouse structure being approximately 9,000 square feet in plan occupied
by a privately owned powder coating company. Based on background information and site
observations, both lots appear to slope downward to the north and northeast at slopes ranging
between 2 and 4 percent. The topography is best described as gently sloping to nearly level in
some areas.
Approximate
Site Location
805 North Ida & 622 East Tamarack Site Conditions
Bozeman, Montana Page 7
3.3 Subsurface Conditions
3.3.1 Soils
The subsurface soil conditions appear to be relatively consistent based on our exploratory
drilling and soil sampling. In general, the subsurface soil conditions encountered within the
borings consist of an existing gravel surface section or topsoil horizon ranging in thickness
from 6 to 10 inches overlying native fat clay. The clays extend to depths of 2.5 to 5.3 feet
below existing site grade and are underlain by native gravels, visually classified as poorly-
graded gravel with clay and sand. The native gravels extend to depths of at least 26.0 feet,
the maximum depth investigated.
The subsurface soils are described in detail on the enclosed boring 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.
EXISTING GRAVEL SURFACING
Existing gravel surfacing sections across each lot are generally consistent. The section
appears to be comprised of base course gravel, visually classified as either clayey gravel or
clayey gravel with sand, being approximately six to ten inches thick.
FAT CLAY
Fat clay was encountered in all five borings beneath the overlying gravel surfacing or topsoil
horizon. The fat clay extends to depths of 2.5 to 5.3 feet with the greatest thickness
observed in the northwest corner of the project area. The clay soil is generally considered
stiff as indicated by two penetration resistance values of 9 and 10 blows per foot (bpf). Two
additional penetration resistance values of 29 bpf were recorded; however, this zone
appeared frozen and is not an accurate representation of the stratum’s relative consistency.
This material is moderately expansive as indicated by the swell test results shown on
Figures 13 and 14. Two samples of the clay exhibited liquid limits of 51 and 53 percent and
plasticity indices of 34 and 32 percent. The natural moisture contents varied from 20.8 to
26.2 percent and average 24.2 percent.
POORLY-GRADED GRAVEL WITH CLAY AND SAND
Native gravels, visually classified as poorly-graded gravel with clay and sand, were
encountered in all borings beneath the clay at depths of 2.5 to 5.3 feet and extending to
depths of at least 26.0 feet, the maximum depth investigated. The gravels are medium
dense to very dense as indicated by penetration resistance values which ranged from 23 to
greater than 100 bpf. Multiple samples were combined to give a general representation of
the material within its respective boring (B-1 through B-4). The four composite samples
contained between 40.2 and 44.2 percent gravel, between 40.4 and 47.0 percent sand, and
between 10.7 and 15.4 percent fines (silt and clay). However, due to the sampling methods
805 North Ida & 622 East Tamarack Site Conditions
Bozeman, Montana Page 8
utilized which are unable to sample rocks larger than 1.5-inch and result in fracturing of
some materials, the samples are not believed to accurately depict the in-situ material
gradation. Additionally, drilling actions at various depths suggests the presence of large
cobbles or boulders within this stratum which were estimated to be up to 12-inch based on
the observations of the field engineer. However, larger boulder size materials are
commonly encountered within similar formations and should be anticipated. The natural
moisture contents varied from 2.5 to 18.5 percent and averaged 8.1 percent.
3.3.2 Ground Water
Ground water was encountered in all borings at depths ranging from 9.6 to 16.0 feet below
the ground surface. During the initial investigation, two monitoring wells were installed in
borings B-1 and B-3. During our second investigation, a third well was installed in boring B-
5. The three wells will be used to monitor the ground water fluctuations throughout the
spring season which high water levels are common. To date, seven readings have been
collected from borings B-1 and B-3. Due to the inability to complete the final boring and
monitoring well during our initial investigation, boring B-5 has been limited to a single
reading. However, monitoring cycles are anticipated to continue for several weeks. The
monitoring results are summarized in the table below.
Date of
Measurement
Ground Water Depth (ft)
B-1 B-3 B-5
3-22-2023 10.04 11.30 -----
3-29-2023 9.67 10.98 -----
4-5-2023 9.92 10.20 -----
4-13-2023 8.64 9.13 -----
4-19-2023 8.40 8.47 -----
4-26-2023 8.55 8.63 -----
5-4-2023 8.74 8.86 8.44
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.
805 North Ida & 622 East Tamarack Engineering Analysis
Bozeman, Montana Page 9
4.0 ENGINEERING ANALYSIS
4.1 Introduction
The primary geotechnical concern regarding this project is the presence of relatively soft, potentially
compressible, and expansive clay soil across the site which pose a risk of settlement and heave to
infrastructure constructed over it. It is our opinion that all clay and previous building foundations
should be removed from beneath building footprints and replaced with properly compacted
structural fill to improve bearing conditions and control settlement potential within the limits of the
planned structures. However, the clay soil is generally thin, and most footings are anticipated to
bear below the clays within the native gravels depending on final site grading. The remaining clay
beneath foundations and interior building slabs can be removed and replaced fairly economically.
Exterior concrete does not require the complete removal and replacement of the native clays and
can utilize conventional construction provided some risk of vertical movement related to
construction over this material can be tolerated for the project. The clay soil is highly compressible,
frost susceptible, and expansive, which can have adverse impacts on similar concrete elements,
especially those directly adjacent to irrigated landscaping.
Finally, ground water on the property is relatively shallow and is anticipated to fluctuate seasonally
within highly permeable native gravels. At the depth anticipated, the ground water is not expected
to be a significant concern for conventional shallow foundations (approximately four feet below
grade) and at grade interior slabs-on-grade; however, plans are currently considering the use of
below grade parking beneath many of the structures which will be impacted by ground water.
Water will be a concern for the construction of these elements as well as the design and long-term
performance which must include water proofing components and consideration of buoyancy forces
on the slab systems when water may rise above the elevation of these below grade components.
4.2 Site Grading and Excavations
The ground surface at the proposed site is considered relatively flat with slight downward slopes
toward the north and northeast. Based on our field work, fat clay, and native gravels will be
encountered in foundation excavations to the depths anticipated. Ground water was encountered in
all borings at depths ranging between 13.0 and 16.0 feet at the time of drilling. However, ground
water measurements performed in monitoring wells constructed on site have shown a rise in the
ground water elevated to depths of approximately 8 to 9 feet below grade in mid-April. Additional
rise in the ground water elevation is anticipated through the spring months and will be documented
in future ground water monitoring of the site and will give a more accurate representation of the
anticipated groundwater levels during seasonal highs. However, ground water levels and
fluctuations can vary from year to year and the monitoring being performed is not capable of or
intended to determine the maximum water levels which may be realized over the life of the project.
805 North Ida & 622 East Tamarack Engineering Analysis
Bozeman, Montana Page 10
4.3 Conventional Shallow Foundations
Considering the subsurface conditions encountered and the nature of the proposed construction, all
structures can be supported on conventional shallow foundations bearing on either properly
compacted native gravel or properly compacted structural fill extending to native gravel. When the
native gravels directly beneath foundation elements cannot be rolled smooth due to protruding
cobbles or boulders, a thin leveling course of compacted gravel should be incorporated beneath the
foundation elements. Footings should not be constructed over any thickness of the native fat clay
due to the potential vertical movements associated with this stratum.
Based on our experience, the theory of elasticity, and using an allowable bearing pressure of 5,000
psf, we estimate the total settlement for footings will be less than ¾-inch. Differential settlement
within individual structures 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.
4.4 Foundation and Retaining Walls
Foundation walls and other soil retaining structures may be required for this project depending on
the final decision regarding below grade structures. Similar features 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.
805 North Ida & 622 East Tamarack Engineering Analysis
Bozeman, Montana Page 11
4.5 Interior Slabs-on-Grade
The primary concern associated with slab-on-grade construction for this project is the presence of
relatively soft, potentially compressible, and expansive clay soils. Based on the risk of vertical
movements and the cost associated with repairs to the completed structure should undesirable
movements occur, it is our opinion that the native clay soils are not suitable for the support of
interior floor slabs. To mitigate the risk of vertical movements, all clays should be removed from
beneath interior slabs-on-grade and replaced with properly compacted structural fill extending to
native gravels.
4.6 Exterior Concrete Flatwork
Exterior flatwork is more readily repaired or replaced should displacement which are considered
excessive occur; thus, conventional construction of exterior flatwork over the in-situ clays is
permissible provided the Owner is willing to accept the risk of movements and understands that a
higher level of maintenance and future repair / replacement may be required. All exterior flatwork
underlain by native clays may be susceptible to vertical movements caused by soil expansion,
settlement, frost heave, or other factors. At a minimum, a granular layer directly below the exterior
flatwork is recommended to provide a structural cushion, a capillary-break from the subgrade, and a
drainage medium; however, this is not intended to mitigate the potential for slab movement in any
way.
Any portions of the exterior flatwork which are especially sensitive to vertical movement or those
which would be overly disruptive or costly to repair and/or replace should consider the removal and
replacement of the clay soils to eliminate the risk of movements in those areas.
4.7 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 rigid concrete pavement, if below grade parking is deemed feasible, will be limited to
daily traffic associated with passenger cars and trucks. Furthermore, we have assumed exterior
parking lots, if used, will be limited to primarily passenger-type vehicles with occasional mid-size
truck traffic associated with deliveries, trash collection, etc. We have assumed that traffic conditions
for both pavement applications will not result in a total equivalent single axle loading (ESAL)
exceeding 50,000 over a typical 20-year design interval.
The potential worst case subgrade material is fat clay encountered on site, which is classified as an
A-7-6 soil in accordance with the American Association of State Highway and Transportation
805 North Ida & 622 East Tamarack Engineering Analysis
Bozeman, Montana Page 12
Officials (AASHTO) classification. AASHTO considers this soil type to be a poor subgrade medium
due to its moisture sensitivity, poor drainage properties, and reduced strength and expansive risk
when wetted. Typical California Bearing Ratio (CBR) values for this type of soil range from 3 to 5
percent when properly compacted. However, natural moisture contents found in samples at the
time of our investigation were higher than the typical optimum moisture content for the material,
which will restrict the ability to compact the clay subgrade without considerable moisture
processing. Thus, the subgrade at the time of construction is likely to exhibit a lower CBR value
because of low compaction levels. During construction, the subgrade should be cleared of all loose
soil debris and rolled smooth using static methods. Vibration should be limited, especially if the
subgrade exhibits signs of instability such as pumping. All subsequent fill should be selected,
placed, and compacted in accordance with our recommendations.
A geotextile acting as a separator is recommended between the pavement section gravels and the
prepared clay subgrade. The recommended geotextile will prevent the upward migration of fines
and the loss of aggregate into the subgrade while adding strength to the overall pavement section
to account for the weak clay subgrade. These benefits will prolong the structural integrity and
performance of the pavement section.
The pavement section presented in this report is based on an assumed CBR value of two percent,
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.
805 North Ida & 622 East Tamarack Recommendations
Bozeman, Montana Page 13
5.0 RECOMMENDATIONS
5.1 Site Grading and Excavations
1. All topsoil and organic material, asphalt, concrete and related construction debris
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, fat clay, and construction debris, are suitable for use as exterior foundation
backfill and general site grading fill on this project.
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) Native Gravels and Structural Fill Below Foundations ............... 98%
b) Native Gravels and Structural Fill Below Building Slabs ............ 98%
c) Below Exterior Concrete & Exterior Foundation Wall Backfill ..... 95%
d) Below Streets, 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%
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. Imported structural fill should be non-expansive, free of organics and debris, and
conform to the material requirements outlined in Section 02234 of the Montana
Public Works Standard Specifications (MPWSS). All gradations outlined in this
standard are acceptable for use on this project; however, 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
805 North Ida & 622 East Tamarack Recommendations
Bozeman, Montana Page 14
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.
Native gravels excavated from other areas of the project site are permissible for use
in structural fill applications provided they do not contain any organics, construction
debris, or other deleterious material. Large cobbles and boulders larger than 4-inch
should be removed from the native materials prior to use as structural fill or in
backfill operations.
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.
5. 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. 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
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.
7. Both interior and exterior footings should bear on properly compacted native gravel
or compacted structural fill (Item 3) extending to native gravel and should be
designed for a maximum allowable soil bearing pressure of 5,000 psf provided
settlements as outlined in the Engineering Analysis are acceptable. The limits of
over-excavation and replacement with compacted structural fill should extend at
least 18 inches beyond the outer limits of the foundation in all directions.
805 North Ida & 622 East Tamarack Recommendations
Bozeman, Montana Page 15
8. Soils disturbed below the planned depths of footing excavations should be re-
compacted to the requirements of Item 2a.
9. 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 7 above.
10. Exterior footings and footings beneath unheated areas should be placed at least 48
inches below finished exterior grade for frost protection.
11. The bottom of the footing excavations should be free of cobbles and boulders to
avoid stress concentrations acting on the base of the footings. When the bearing
surface cannot be rolled smooth due to protruding cobbles or boulders, a thin
leveling course of material conforming to MPWSS Section 02235 may be placed
and compacted directly beneath the foundation. Compaction shall conform to the
requirements of Item 2a.
12. 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 200 psf per foot of depth are appropriate for footings supported on native gravels
or structural fill (Item 3) and backfilled with on-site materials per Item 2 above.
13. 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.
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.
14. Basement walls and other retaining walls which are being considered for below
grade parking alternatives should be designed for a lateral earth pressure computed
on the basis of an at-rest equivalent fluid unit weight of 60 pcf for backfill consisting
of on-site native gravels and clays. For consideration of seismic forces, a seismic
equivalent fluid unit weight of 80 pcf is appropriate for the increased lateral forces
associated with earthquake motions for similar backfill conditions.
Any portions of the below grade wall structures anticipated to extend below the
typical high water elevation should be designed including a lateral hydrostatic force
in addition to the lateral forces provided previously. Hydrostatic forces need not be
805 North Ida & 622 East Tamarack Recommendations
Bozeman, Montana Page 16
considered when the project will include dewatering systems capable of maintaining
the ground water elevation below the design footing elevation throughout the year.
15. Backfill should be selected, placed, and compacted per Item 2 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 foundation walls.
16. Exterior footing drains are recommended to remove ground water seepage and
infiltrated surface runoff away from foundation soils around below grade structures.
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.
Foundation drains may be omitted at the discretion of the design engineer when the
foundations and slabs systems are designed to resist all hydrostatic and buoyancy
forces in addition to incorporating water proofing methods to prevent intrusion of
water into the structure.
17. When foundation walls are shallow and not anticipated to extend below the high
ground water level, they may be damp-proofed in accordance with the applicable
sections of the International Building Code (IBC).
18. All foundation walls for below grade structures which are anticipated to extend below
the high ground water level obtained through future monitoring should incorporate
water-proofing methods in accordance with the applicable sections of the
International Building Code (IBC).
5.4 Interior Slabs-on-Grade
19. Based on the compressibility potential, frost susceptibility, and expansive potential
of the native clay soils, they are not considered suitable to remain beneath interior
slabs-on-grade due to potential impacts associated with future repairs. All interior
building slabs should be supported on properly compacted structural fill (Item 3)
extending to native gravel.
805 North Ida & 622 East Tamarack Recommendations
Bozeman, Montana Page 17
20. An optional cushion course consisting of material conforming to the requirements
outlined in Section 02235 of the Montana Public Works Standard Specifications
(MPWSS) can be placed beneath interior slabs depending on the gradation of
structural fill utilized.
Alternatively, clean washed chips exhibiting a high fracture percentage exceeding
70 percent single face may be utilized as a cushion material provided the overall
thickness does not exceed 12 inches. This layer should be compacted using a
minimum of four passes with a smooth vibratory plate compactor following
installation.
21. Concrete floor slabs should be designed using a modulus of vertical subgrade
reaction no greater than 400 pci when designed and constructed as recommended
above.
22. Geotechnically, an underslab vapor barrier is not required for at grade building slabs
on this site. 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.
23. Unless drain systems are designed to maintain the sites water level below the
design slab elevation, all slabs-on-grade associated with potential below grade
structures should be adequately water-proofed to prevent the intrusion of water into
the space and designed to resist buoyancy forces associated with maximum
expected water level.
Even when drain systems will be utilized to maintain a ground water level below the
basement grade, a vapor barrier is still advised beneath all below grade
components.
5.5 Exterior Concrete Flatwork
24. For normally loaded, exterior concrete flatwork, a typical cushion course consisting
of free-draining, crushed gravel may 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 clay soils present on site. 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 conventional construction is utilized it is assumed that the Owner is
805 North Ida & 622 East Tamarack Recommendations
Bozeman, Montana Page 18
willing to accept the potential reduced concrete performance and increased
maintenance time and expense.
25. Cushion course materials utilized beneath exterior 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.
26. If no acceptable risk can be assumed by the Owner, the only positive method to
control potential slab movements is to completely remove and replace the clay soils
with compacted structural fill (Item 3) extending to the surface of the native gravel.
Such improvements should be implemented beneath any portions of the exterior
concrete in which higher levels of performance are expected or those which will be
especially difficult or expensive to replace should movements be considered
excessive.
5.6 Pavements
27. The following flexible pavement section or an approved equivalent section should be
selected in accordance with the discussions in the Engineering Analysis for use in
exterior parking applications.
Pavement Component Component Thickness
Asphaltic Concrete Pavement 3”
Crushed Base Course 6”
Crushed Subbase Course 12”
Total 21”
28. The following rigid concrete pavement section or an approved equivalent section
should be selected in accordance with the discussions in the Engineering Analysis
for use in below grade parking applications. This section has been designed
assuming all below grade parking will be at depths greater than five feet and will be
supported over native gravels.
805 North Ida & 622 East Tamarack Recommendations
Bozeman, Montana Page 19
Pavement Component Component Thickness
Portland Cement Concrete (PCC)
Pavement 6”
Crushed Base Course 6”
Crushed Subbase Course -----
Total 12”
29. Final asphalt thicknesses exceeding 3 inches shall be constructed in two uniform
lifts.
30. Crushed base courses shall conform to the material properties outlined in 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.
Crushed subbase courses shall conform to material properties outlined in Section
02234 of the MPWSS. All gradations outlined in this specification are acceptable for
this application based on local availability and contractor preference.
31. 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.
32. A geotextile is recommended between the asphalt pavement section and the
prepared clay subgrade to prevent the migration of fines upward into the gravel and
the loss of aggregate into the subgrade as well as to reinforce the pavement
structure. A Mirafi RS380i has been assumed in our design section and should not
be substituted without our prior review and modification (if necessary) of the overall
pavement section.
33. Ideally, 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% 35.8 -30.6 PG 52-34
98% 39.8 -39.4 PG 52-40
805 North Ida & 622 East Tamarack Recommendations
Bozeman, Montana Page 20
In our experience, neither of the oil grades summarized above are available through
local suppliers and would result in additional costs associated with importing
specialized products. Thus, for this project the use of a PG 58-28 grade oil is
recommended as this product is locally available through asphalt suppliers and will
provide the highest reliability level without the added expense of importing
specialized products.
34. The concrete utilized for rigid pavement sections should 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 determining the appropriate
section for the concrete properties to be utilized on the project.
A modulus of vertical subgrade reaction no greater than 400 pci is appropriate for
the design of the concrete reinforcing by others.
5.7 Continuing Services
Three additional elements of geotechnical engineering service are important to the successful
completion of this project.
35. 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.
36. 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.
37. 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:
805 North Ida & 622 East Tamarack Recommendations
Bozeman, Montana Page 21
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 1,500 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
805 North Ida & 622 East Tamarack Summary of Field & Laboratory Studies
Bozeman, Montana Page 22
6.0 SUMMARY OF FIELD AND LABORATORY STUDIES
6.1 Field Explorations
The initial field exploration program was conducted on March 13th and 14th of 2023. However, due
to the time of year and high volumes of snow in the area, the exploration program could not be
completed without causing excessive disturbance to the site. Following seasonal snowmelt and
drier conditions, the final boring was completed on April 25th of 2023 using alternative drilling
equipment. The investigations consisted of five borings drilled to depths ranging from 24.2 to 26.0
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 Longyear BK-81
drill rig equipped with 4.25-inch I.D. hollowstem augers. The subsurface exploration and sampling
methods used are indicated on the attached boring logs. The borings were logged by Craig
Nadeau, PE and Nic Couch, EI of TD&H Engineering. The location of the borings were recorded
using a Trimble handheld GPS unit. The locations shown are accurate to within 18 inches of the
actual field location.
Samples of the subsurface materials were taken using a 1⅜-inch I.D. split spoon sampler. The
sampler was 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, which include soil
descriptions, sample depths, and penetration resistance values, are presented on Figures 2 through
6.
Measurements to determine the presence and depth of ground water were made in the borings by
lowering an electronic water sounder through the open boring or auger shortly after the completion
of drilling. The depths or elevations of the water levels measured, if encountered, and the date of
measurement are shown on the boring 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.
805 North Ida & 622 East Tamarack Summary of Field & Laboratory Studies
Bozeman, Montana Page 23
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.
Constant Volume Swell Determination of the maximum uplift force exerted by a soil
specimen during inundation by gradual increases in the
applied resisting force to maintain a fixed samples height.
Constant Pressure Swell Determination of the percent strain experienced by a soil
specimen during inundation under a fixed loading condition.
The laboratory testing program for this project consisted of 39 moisture-visual analyses, 4 sieve
(grain-size distribution) analyses, and 2 Atterberg Limits analyses. The results of the water content
analyses are presented on the boring logs, Figures 2 through 6. The grain-size distribution curves
and Atterberg limits are presented on Figures 7 through 12. In addition, one constant volume swell
test and one constant pressure swell test were performed. The swell testing results are presented
on Figures 13 and 14.
805 North Ida & 622 East Tamarack Limitations
Bozeman, Montana Page 24
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 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 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 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
prepared your geotechnical report to provide construction observation is the most effective method
of managing the risks associated with unanticipated conditions.
805 North Ida & 622 East Tamarack Limitations
Bozeman, Montana Page 25
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 logs and presented in discussions of subsurface conditions
included in this report.
Prepared by: Reviewed by:
Nic Couch EI Kyle Scarr PE & Principal
Geotechnical Engineer Geotechnical Engineer
TD&H ENGINEERING TD&H ENGINEERING
DESIGNED BY:QUALITY CHECK:JOB NO.FIELDBOOKDRAWN BY:DATE:B23-012 GEOTECHREV DATE NOT FORCONSTRUCTION
REVISION
805 NORTH IDA AND 622 EAST TAMARACK
BOZEMAN, MONTANA
BORING AND MONITORING WELL LOCATION MAP B23-01204.04.2023.DWGSHEETFG1.0ZJLEngineering
tdhengineering.com
J:\2023\B23-012 805 Ida - 622 Tamarack\05_DESIGN (Tech & Reports)\GEOTECH\FIGURES\B23-012 GEOTECH.dwg, 4/19/2023 4:37:32 PM, ZJL
0
2.5
5
7.5
10
12.5
15
17.5
FILL: Clayey GRAVEL with Sand, very dense, brown,
frozen
Fat CLAY, very stiff to stiff, dark brown, frozen to
moist, frozen down to 2 ft
Poorly-Graded GRAVEL with Clay and Sand, very
dense, brown, slightly moist to wet
0.7
5.3
21-15-
14
5-4-6
3-19-35
23-32-
50/0.42
25-39-
46
24-38-
50/0.25
54
82/0.92
86
88/0.75
LEGEND LOG OF SOIL BORING B-1SPT blows per foot Atterberg Limits
Field Moisture content 805 North Ida & 622 East Tamarack
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE
2-1/2-inch I.D. split spoon Drilled by:Haztech Drilling
Truck-Mounted Longyear BK-81 with 4.25-inch I.D. 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 13, 2023 B23-012-001
No sample recovery Figure No.2
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Gravel Surfacing
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
20
22.5
25
27.5
30
32.5
35
Bottom of Boring (Monitoring Well Installed)
- Screen from 25 to 15 ft
- Sand from 25 to 7 ft
- Bentonite from 7 to 1.5 ft
25.9
9-50/
0.5
21-50/
0.33
50/0.5
50/0.33
LEGEND LOG OF SOIL BORING B-1SPT blows per foot Atterberg Limits
Field Moisture content 805 North Ida & 622 East Tamarack
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE
2-1/2-inch I.D. split spoon Drilled by:Haztech Drilling
Truck-Mounted Longyear BK-81 with 4.25-inch I.D. 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 13, 2023 B23-012-001
No sample recovery Figure No.2
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Gravel Surfacing
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
FILL: Clayey GRAVEL with Sand, very dense, brown
and gray, wet to frozen
Fat CLAY, stiff, dark brown, frozen to moist, frozen
down to 1 ft
- See Figures 13 & 14 for Swell Testing Results
Poorly-Graded GRAVEL with Clay and Sand, medium
dense to very dense, brown, moist to wet
0.8
4.0
27-23-6
PUSH
9-14-9
23-50/
0.46
29-43-
45
13-21-
50/0.42
T
51
50/0.46
88
71/0.92
LEGEND LOG OF SOIL BORING B-2SPT blows per foot Atterberg Limits
Field Moisture content 805 North Ida & 622 East Tamarack
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE
2-1/2-inch I.D. split spoon Drilled by:Haztech Drilling
Truck-Mounted Longyear BK-81 with 4.25-inch I.D. 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 13-14, 2023 B23-012-001
No sample recovery Figure No.3
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Gravel Surfacing
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
20
22.5
25
27.5
30
32.5
35
Bottom of Boring
26.0
26-36-
31
20-50/
0.46
67
50/0.46
LEGEND LOG OF SOIL BORING B-2SPT blows per foot Atterberg Limits
Field Moisture content 805 North Ida & 622 East Tamarack
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE
2-1/2-inch I.D. split spoon Drilled by:Haztech Drilling
Truck-Mounted Longyear BK-81 with 4.25-inch I.D. 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 13-14, 2023 B23-012-001
No sample recovery Figure No.3
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Gravel Surfacing
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
FILL: Clayey GRAVEL, appears dense, brown, frozen
Fat CLAY, appears stiff, black to brown, moist, some
cinders and ash, potential fill
Poorly-Graded GRAVEL with Clay and Sand, medium
dense to very dense, brown, moist to wet
0.5
2.5
9-10-15
3-44-
50/0.33
15-29-
42
22-31-
32
13-19-
45
94/0.33
71
63
64
LEGEND LOG OF SOIL BORING B-3SPT blows per foot Atterberg Limits
Field Moisture content 805 North Ida & 622 East Tamarack
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE
2-1/2-inch I.D. split spoon Drilled by:Haztech Drilling
Truck-Mounted Longyear BK-81 with 4.25-inch I.D. 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 14, 2023 B23-012-001
No sample recovery Figure No.4
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Gravel Surfacing
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
20
22.5
25
27.5
30
32.5
35
Bottom of Boring (Monitoring Well Installed)
- Screen from 25 to 15 ft
- Sand from 25 to 7 ft
- Bentonite from 7 to 1.5 ft
26.0
24-45-
47
40-50/
0.33
92
50/0.33
LEGEND LOG OF SOIL BORING B-3SPT blows per foot Atterberg Limits
Field Moisture content 805 North Ida & 622 East Tamarack
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE
2-1/2-inch I.D. split spoon Drilled by:Haztech Drilling
Truck-Mounted Longyear BK-81 with 4.25-inch I.D. 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 14, 2023 B23-012-001
No sample recovery Figure No.4
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Gravel Surfacing
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
TOPSOIL: Lean CLAY, appears soft to firm, dark
brown, moist
Fat CLAY, firm to stiff, dark brown, moist
Poorly-Graded GRAVEL with Clay and Sand, very
dense, brown, moist to wet
No Recovery
0.5
3.5
2-3-6
PUSH
16-30-
50
50/0.25
16-39-
50/0.33
26-37-
29
31-24-
22
T
53
80
50/0.25
89/0.83
66
LEGEND LOG OF SOIL BORING B-4SPT blows per foot Atterberg Limits
Field Moisture content 805 North Ida & 622 East Tamarack
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE
2-1/2-inch I.D. split spoon Drilled by:Haztech Drilling
Truck-Mounted Longyear BK-81 with 4.25-inch I.D. 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 14, 2023 B23-012-001
No sample recovery Figure No.5
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Vegetated Soil, Snow Covered
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
20
22.5
25
27.5
30
32.5
35
No Recovery
Bottom of Boring
24.2
30-50/
0.25
50/0.2
50/0.25
50/0.2
LEGEND LOG OF SOIL BORING B-4SPT blows per foot Atterberg Limits
Field Moisture content 805 North Ida & 622 East Tamarack
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE
2-1/2-inch I.D. split spoon Drilled by:Haztech Drilling
Truck-Mounted Longyear BK-81 with 4.25-inch I.D. 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 14, 2023 B23-012-001
No sample recovery Figure No.5
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Vegetated Soil, Snow Covered
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
TOPSOIL: Lean CLAY, appears firm, dark brown to
black, moist, organics
Fat CLAY, firm, dark brown to brown, moist, some
coal
Poorly-Graded GRAVEL with Clay and Sand, dense
to very dense, light brown to tan, slightly moist
- Brown, and moist to wet below 7 ft
1.0
3.5 2-4-14
33-44-
50
25-50/
0.4'
49-47-
39
3-7-34
94
50/0.4'
86
LEGEND LOG OF SOIL BORING B-5SPT blows per foot Atterberg Limits
Field Moisture content 805 North Ida & 622 East Tamarack
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Nic Couch, EI
2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling
Truck-Mounted Mobile B-60X with 4.25 I.D. 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.
April 25, 2023 B23-012-001
No sample recovery Figure No.6
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Vegetated Soil
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
20
22.5
25
27.5
30
32.5
35
Bottom of Boring (Monitoring Well Installed)
- Screen from 25 to 15 ft
- Sand from 25 to 6 ft
- Bentonite from 6 to 1 ft
26.0
1-26-50
36-50/
0.45'
76
50/0.45'
LEGEND LOG OF SOIL BORING B-5SPT blows per foot Atterberg Limits
Field Moisture content 805 North Ida & 622 East Tamarack
Bozeman, MontanaGroundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Nic Couch, EI
2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling
Truck-Mounted Mobile B-60X with 4.25 I.D. 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.
April 25, 2023 B23-012-001
No sample recovery Figure No.6
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Vegetated Soil
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
Tested By: BC Checked By:
3-24-2023
7
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Clayey SAND with Gravel
1.5"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
94.5
91.1
80.3
74.3
59.8
45.5
34.2
25.7
21.4
19.0
17.8
14.4
18.0317 14.9994 4.8048
2.7097 0.6187 0.0864
SC
Report No. A-27510COMP-206
Brick Capital RE
805 North Ida & 622 East Tamarack
Bozeman, Montana
B23-012-001
Material Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: B-1
Sample Number: A-27510COMP Depth: 7.5 - 25.9 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 8.9 31.3 14.3 19.8 11.3 14.46 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:
3-24-2023
8
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Clayey SAND with Gravel
1.5"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
98.8
92.9
80.2
74.1
59.0
44.6
32.8
24.4
19.9
17.3
15.8
12.0
17.3165 14.8826 4.9813
2.8748 0.6884 0.1335
SC
Report No. A-27518COMP-206
Brick Capital RE
805 North Ida & 622 East Tamarack
Bozeman, Montana
B23-012-001
Material Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: B-2
Sample Number: A-27518COMP Depth: 4.0 - 26.0 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 7.1 33.9 14.4 20.2 12.4 12.06 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: JB Checked By:
3-30-2023
9
(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
85.8
74.1
68.3
55.8
43.9
34.1
26.9
23.0
20.4
19.1
15.4
22.3268 18.5403 6.0380
3.2275 0.5847
GC
Report No. A-27525COMP-206
Brick Capital RE
805 North Ida & 622 East Tamarack
Bozeman, Montana
B23-012-001
Material Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: B-3
Sample Number: A-27525COMP Depth: 5.0 - 26.0 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 14.2 30.0 11.9 17.0 11.5 15.46 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: JB Checked By:
3-30-2023
10
(no specification provided)
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*
Poorly-Graded SAND with Clay and Gravel
1.5"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
90.2
85.5
76.6
71.9
59.6
45.1
31.1
21.7
17.4
15.1
13.9
10.7
25.0795 18.5363 4.8641
2.7029 0.7917 0.1765
SP-SC
Report No. A-27534COMP-206
Brick Capital RE
805 North Ida & 622 East Tamarack
Bozeman, Montana
B23-012-001
Material Description
Atterberg Limits
Coefficients
Classification
Remarks
Location: B-4
Sample Number: A-27534COMP Depth: 7.5 - 20.8 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 14.5 25.9 14.5 23.4 11.0 10.76 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 CONTENT49.6
50
50.4
50.8
51.2
51.6
52
52.4
52.8
53.2
53.6
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: B-2
Sample Number: A-27517 Depth: 2.5 - 4.0 ft
Figure
Fat CLAY 51 17 34 CH
B23-012- Brick Capital RE
11
Report No. A-27517-207
Date: 3-30-2023805 North Ida & 622 East Tamarack
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 CONTENT51.7
52.2
52.7
53.2
53.7
54.2
54.7
55.2
55.7
56.2
56.7
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-27532 Depth: 2.5 - 3.5 ft
Figure
Fat CLAY 53 21 32 CH
B23-012- Brick Capital RE
12
Report No. A-27532-207
Date: 3-30-2023805 North Ida & 622 East Tamarack
Bozeman, Montana
Sat. Moist
Project No.B23-012-001 Brick Capital RE Remarks:
Project:805 North Ida / 622 East Tamarack Report No. A-27517-216
Bozeman, Montana
Location:B-2 Sample Depth (ft):2.5 - 4.0
13
N/A 0.68090.8 22.9 100.1 51 34 2.7 360 N/A N/A N/A
Cs Swell Pressure
(psf)
~ 800
Overburden
(psf)
Pc
(psf)Cc
CONSTANT VOLUME SWELL TEST REPORT
AASHTO
A-7-6
USCS
CH
MATERIAL DESCRIPTION
Fat CLAY
Natural Dry Density
(pcf)LL PI
Swell
(%)eo
Sp.
Gr.
Technician:CRN Reviewed By:
Client:
Figure
0
100
200
300
400
500
600
700
800
900
0.00 500.00 1000.00 1500.00 2000.00 2500.00 3000.00 3500.00 4000.00 4500.00
Swell Pressure (psf)Time (min)
Sat. Moist
Project No.B23-012-001 Brick Capital RE Remarks:
Project:805 North Ida / 622 East Tamarack Report No. A-27517-216
Bozeman, Montana
Location:B-2 Sample Depth (ft):2.5 - 4.0
14
Technician:CRN Reviewed By:
Client:
Figure
CONSTANT PRESSURE SWELL TEST REPORT
AASHTO
A-7-6
USCS
CH
MATERIAL DESCRIPTION
Fat CLAY
Natural Dry Density
(pcf)LL PI
Swell
(%)eo
Sp.
Gr.
Overburden
(psf)
Pc
(psf)Cc
N/A N/A
Cs Test Pressure
(psf)
100 ~ 1.5 0.69087.2 22.3 99.4 51 34 2.7 360 N/A
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0.00 500.00 1000.00 1500.00 2000.00 2500.00 3000.00 3500.00 4000.00 4500.00
Sample Expansion (%)Time (min)
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
General Project Information
Project Number: B23-012-001
Project Title: 805 Ida & 622 Tamarack
Project Description:
Climatic Data Source (MERRA)
Latitude, Degree: 45.68827
Longitude, Degree: -111.02717
Climatic Data
Lowest Yearly Air Temperature, ºC: -40.90
Low Air Temp Standard Deviation, ºC: 5.19
Yearly Degree-Days > 10 Deg. ºC: 1656.66
High Air Temperature of high 7 days: 28.91
Standard Dev. of the high 7 days: 2.01
Low Pavement Temperature 50%: -30.50
Low Pavement Temperature 98%: -39.30
High Avg Pavement Temperature of 7 Days 50%: 50.90
High Avg Pavement Temperature of 7 Days 98%: 55.06
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 M320-10 Performance-Graded Asphalt Binder
PG Temperature High Low
Performance Grade Temperature at 50% Reliability 35.8 -30.6
Performance Grade Temperature at 98% Reliability 39.8 -39.4
Adjustment for Traffic (AASHTO M323-13)2.8
Adjustment for Depth 0.0 -0.0
Adjusted Performance Grade Temperature 42.6 -39.4
Selected PG Grade 52 -40
PG Grade M323, PG 52-40