HomeMy WebLinkAbout012 - Appendix K - Geotech ReportMONTANA | WASHINGTON | IDAHO | NORTH DAKOTA | PENNSYLVANIA
JOB NO. B23-048-002 March 2024
REPORT OF GEOTECHNICAL INVESTIGATION
CLIENT
ENGINEER
S2K Miller Holding, LLC
Attn: D. Kerry Nickerson
4643 S Ulster St, Ste. 1500
Denver, CO 80237
Craig R. Nadeau, PE
Craig.nadeau@tdhengineering.com
REPORT OF GEOTECHNICAL INVESTIGATION
PROJECT NAME
PROJECT LOCATION 406.586.0277
tdhengineering.com
234 E Babcock St, Suite 3
Bozeman, MT 59715
BLOCK B CONDOS – EAST BABCOCK STREET
BOZEMAN, MONTANA
Block B Condos – East Babcock Street Table of Contents
Bozeman, Montana i
Table of Contents
1.0 EXECUTIVE SUMMARY ......................................................................................................... 1
2.0 INTRODUCTION ..................................................................................................................... 2
2.1 Purpose and Scope .......................................................................................................... 2
2.2 Project Description ........................................................................................................... 2
3.0 SITE CONDITIONS ................................................................................................................. 4
3.1 Geology and Physiography .............................................................................................. 4
3.2 Surface Conditions ........................................................................................................... 5
3.3 Subsurface Conditions ..................................................................................................... 5
3.3.1 Soils ......................................................................................................................... 5
3.3.2 Ground Water ......................................................................................................... 7
4.0 ENGINEERING ANALYSIS .................................................................................................... 8
4.1 Introduction ....................................................................................................................... 8
4.2 Site Grading and Excavations.......................................................................................... 8
4.3 Conventional Shallow Foundations (Recommended) ..................................................... 8
4.4 Mat Foundations............................................................................................................... 8
4.5 Foundation Walls.............................................................................................................. 9
4.6 Exterior Concrete Flatwork .............................................................................................. 9
5.0 RECOMMENDATIONS ......................................................................................................... 11
5.1 Site Grading and Excavations........................................................................................ 11
5.2 Conventional Shallow Foundations ............................................................................... 12
5.3 Mat Foundation .............................................................................................................. 13
5.4 Foundation Walls............................................................................................................ 14
5.5 Interior Slabs and Exterior Concrete Flatwork ............................................................... 15
5.6 Continuing Services ....................................................................................................... 15
6.0 SUMMARY OF FIELD & LABORATORY STUDIES ............................................................ 17
6.1 Field Explorations ........................................................................................................... 17
6.2 Laboratory Testing ......................................................................................................... 18
7.0 LIMITATIONS ........................................................................................................................ 19
Block B Condos – East Babcock Street Appendix
Bozeman, Montana ii
APPENDIX
Boring Location Map (Figure 1)
Logs of Exploratory Borings (Figures 2 through 4)
Laboratory Test Data (Figures 5 through 13)
Construction Standard 02801-06C
Soil Classification and Sampling Terminology for Engineering Purposes
Classification of Soils for Engineering Purposes
Block B Condos – East Babcock Street Executive Summary
Bozeman, Montana Page 1
REPORT OF GEOTECHNICAL INVESTIGATION
BLOCK B CONDOS - EAST BABCOCK STREET
BOZEMAN, MONTANA
1.0 EXECUTIVE SUMMARY
During the geotechnical investigation conducted for the redevelopment project near the intersection
of East Babcock Street and South Church Avenue in Bozeman, Montana, it was found that the
primary soil type is gravel, with overlying and underlying layers of lean clay and sand. Ground
water was detected at a depth of 21 feet at the location of one deep boring completed in February
2024. Detailed boring logs and laboratory test results are provided in this report. The geotechnical
investigation for this project could not be completed as originally proposed as access to a private lot
on the far east end was not yet allowed and limitations accessing much of the site with a truck-
mounted drill rig were encountered due to existing infrastructure and overhead as well as below
ground utility conflicts. Thus, two of the three borings were completed using a small track-mounted
drill rig which couldn't achieve the proposed depths due to auger refusal in dense gravel. Additional
investigation can be considered once full access to the property for larger drilling equipment is
feasible if the design team feels it is warranted.
We acknowledge that the project involves removing five residential structures and two apartment
complexes and erecting a new seven-story condominium with an underground parking facility. The
main geotechnical concern for this site is that the project is proposed to include an underground
parking facility that has a depth of 12 feet below ground level. However, the foundation is proposed
to bear on very dense gravel which is a suitable material for support of the structure. After
conducting analyses of two potential foundation options, the recommended option is a conventional
shallow foundation system but an alternative option which can be considered is a mat foundation
system. Detailed recommendations and preparations for the foundation options are provided in this
report.
Block B Condos – East Babcock Street Introduction
Bozeman, Montana Page 2
2.0 INTRODUCTION
2.1 Purpose and Scope
This report presents the results of our recent geotechnical study for the planned condominium
located at 523 East Babcock Street in Bozeman, Montana. The purpose of the recent geotechnical
study was to determine the general surface and subsurface conditions at the proposed site and to
develop geotechnical engineering recommendations for support of the proposed condominium
structure, underground parking facility, and design of related facilities. This report describes the field
exploration process, the surface and subsurface conditions encountered, laboratory and
engineering analyses conducted, and presents our recommendations for the foundation options and
related site developments.
The geotechnical investigation for this project could not be completed as originally proposed due to
our inability to access a private lot on the east end as well as conflicts with existing infrastructure
and utilities (overhead and below ground) which made access for the required truck-mounted drill
impossible to most areas of the property. Thus, a small track-mounted drill rig was used for two of
the three borings performed but this machine couldn't achieve the proposed depths due to its
limited power and reaching auger refusal in the dense gravel. These borings achieved the critical
goal of identifying the depth to the dense gravels encountered in the deep boring and we believe
the findings are sufficient to provide geotechnical recommendations. Additional investigation can
be considered once full access to the property for larger drilling equipment is feasible if the design
team feels it is warranted.
Our fieldwork included drilling three soil borings within the general limits of the proposed project.
Samples were obtained from the borings and returned to our laboratory in Great Falls for testing.
Laboratory testing was performed on selected soil samples to determine the engineering properties
of the subsurface materials. The information obtained during our field investigation, laboratory
testing, and engineering analyses were used to develop design recommendations for the foundation
options.
2.2 Project Description
It is our understanding that the proposed project consists of a seven-story condominium featuring
an underground parking facility. Information regarding the structural design of the building was
minimal during the preparation of this report. Therefore, we assume that construction will consist of
concrete walls for the underground parking facility with one to two stories of concrete podium style
construction and wood framing for the remaining levels. Preliminary foundation loads were not
available during the time of this report. Referring to our experience with similar construction, we
have assumed that wall loads will be less than 9,000 pounds per lineal foot and column loads, if
any, will be less than 450 kips. If the assumed design values vary from the actual project
parameters, the recommendations presented in this report should be re-evaluated.
Block B Condos – East Babcock Street Introduction
Bozeman, Montana Page 3
Site development will include the demolition and removal of five residential structures and two
apartment complexes throughout the site as well as all existing pavements and site infrastructures.
The new site development is expected to be limited to exterior concrete flatwork and landscaping as
the building footprint encompasses most of the available lot area. Detailed recommendations and
preparations for site development are provided in this report. If the locations or conditions are
significantly different from those described in this report, we should be notified to re-evaluate the
recommendations contained in this report.
Block B Condos – East Babcock Street Site Conditions
Bozeman, Montana Page 4
3.0 SITE CONDITIONS
3.1 Geology and Physiography
The site is geologically characterized as alluvial deposits (Qal, Qafo, and Qabo) that are comprised
of variable layering of gravel, sand, and lean clay deposits. The upper layering is comprised of fine-
grained lean clay with a minor sand fraction and this zone was observed to be medium stiff to stiff.
Occasional layers of sand with clay deposits were observed in this zone. The upper lean clay and
sand layers are underlain by a lower gravel layer that was observed to be medium dense to very
dense. According to the geologic map below, bedrock of the Maidson Valley member (Tscmv) is
displayed locally which is a conglomeratic material consisting of mostly siltstone, marlstone
(mudstone), and sandstone materials. However, obviously identifiable or competent bedrock
materials were not encountered during the field investigation.
Geologic Map of the Bozeman 30’ x 60’ Quadrangle Southwestern Montana
(Vuke, Lonn, Berg, Schmidt, 2014)
SITE
Block B Condos – East Babcock Street Site Conditions
Bozeman, Montana Page 5
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
At the time of our site investigation, the proposed project site was developed and consisted of
buildings, concrete pavement, asphalt pavement, gravel surfacing pavement, and landscaping. The
surface conditions are summarized below. Based on available Google Earth imagery and site
observations, the topography of the site is best described as flat.
ASPHALT & GRAVEL SURFACING PAVEMENT
Asphalt pavement was encountered at one boring location and gravel surfacing pavement
was encountered at one other boring location. The asphalt pavement had a thickness of 4
inches and the gravel surfacing pavement had a thickness of 3.5 inches. The need for
complete removal of both pavements during site preparation should be anticipated.
LIGHT VEGETATION AND TOPSOIL
Light vegetation and topsoil were encountered at the final boring location. The topsoil had a
thickness of 1.0 foot and will warrant complete removal during site preparation.
3.3 Subsurface Conditions
3.3.1 Soils
The stratigraphic profiles typically consist of a variation in layering of native lean clay and
sand which overlay gravel containing varying amounts of cobbles, sand, silt, and clay. The
depth and thickness of these alluvial materials vary significantly across the development
site. Obviously identifiable or competent bedrock materials were not encountered during the
field investigation; however, materials encountered below the native gravels could represent
completely weathered and very soft conglomerate formation materials. The project’s
maximum depth explored was 31.0 feet. For the purposes of our summary below and
engineering analyses, materials present at depth have been treated as soils due to their
density and physical properties being more consistent with soil than rock.
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.
Block B Condos – East Babcock Street Site Conditions
Bozeman, Montana Page 6
FILL MATERIAL
Fill materials encountered are limited to the existing pavement materials seen on site. The
asphalt pavement overlies a base course that was visually classified as a poorly-graded
gravel with clay and sand. This material extends to a depth of 0.7 feet and should anticipate
the need for complete stripping during site preparation.
LEAN CLAY
At depths ranging from 0.3 to 1.0 feet, we encountered a layer of lean clay. This layer varied
in thickness from 3.5 to 7.0 feet. Lean clay was also encountered at a depth of 29.0 feet and
extended below the exploratory depth of 31.0 feet. This zone may represent completely
weathered bedrock formations but should be treated as soil due to the very soft condition.
The composition of the lean clay varies slightly in terms of percentages of sand and gravel.
The lean clay was medium stiff to stiff as indicated by penetration resistance values which
ranged from 4 to 14 blows per foot (bpf) and averaged 11 bpf. The natural moisture content
ranged from 13.6 to 31.7 percent, with an average of 21.0 percent. Out of the two tested
samples, the materials contained:
• Gravel: 3.8 and 8.2 percent
• Sand: 31.7 and 37.7 percent
• Fines (clay and silt): 58.5 and 60.6 percent
Based on liquid limits of 36 and 40 percent and plasticity indices of 17 and 20 percent, the
fines in two samples were predominantly lean clay of medium to high plasticity.
GRAVEL
At depths ranging from 4.5 to 7.7 feet, we encountered native gravels. The thickness of this
layer was 22.0 feet at one boring location. The composition of the gravel varies in terms of
percentages of gravel, sand, silt, and clay. The gravel was medium dense to very dense as
indicated by penetration resistance values which ranged from 10 to more than 100 blows
per foot (bpf) and averaged 62 bpf. The natural moisture content ranged from 2.0 to 13.7
percent, with an average of 5.3 percent. The proportion of gravel differed slightly across the
site and not all locations matched the percentages found in the tested samples. Out of the
three tested samples, the materials contained:
• Gravel: 51.3 to 54.9 percent
• Sand: 32.7 to 38.4 percent
• Fines (clay and silt): 10.3 to 14.2 percent
SAND
At a depth of 4.5 feet, we encountered a thin layer of sand. This layer’s thickness was 1.7
feet. The sand was very loose as indicated by a penetration resistance value of 2 bpf. The
natural moisture content was 13.7 percent. Out of the tested sample, the material contained:
Block B Condos – East Babcock Street Site Conditions
Bozeman, Montana Page 7
• Gravel: 0.2 percent
• Sand: 75.4 percent
• Fines (clay and silt): 24.4 percent
3.3.2 Ground Water
Ground water was encountered at the location of one deep boring conducted in February
2024 at a depth of 21.0 feet below the ground surface. This location was completed as a
ground water monitoring well; however, no additional data collection had been performed at
the time of this report. 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.
Block B Condos – East Babcock Street Engineering Analysis
Bozeman, Montana Page 8
4.0 ENGINEERING ANALYSIS
4.1 Introduction
The main geotechnical concern for this site is that the project is proposed to include an
underground parking facility that has a depth of 12 feet below ground level. At such depths, the
foundation is anticipated to bear within the very dense gravel which is a suitable material for support
of the structure. Therefore, two types of foundation systems for this project were analyzed and the
recommendations are provided in the recommendations section below.
4.2 Site Grading and Excavations
The ground surface at the proposed site is flat. Based on our field investigation, pavement
materials, topsoil, lean clay, sand, and gravel will be encountered in the parking facility and
foundation excavations to the depths anticipated. It is expected that caving challenges will be
encountered during construction for excavations associated with both foundations and utilities.
Ground water should be below the anticipated depths of excavations. However, depending on the
time of year and depth of excavations, occasional pockets of trapped or perched ground water and
lateral seepage from excavation sidewalls associated with recent precipitation events should be
anticipated.
4.3 Conventional Shallow Foundations (Recommended)
Considering the subsurface conditions encountered and the nature of the proposed construction,
the structure can be supported on conventional shallow foundations bearing on properly compacted
native gravel. Based on our experience, the theory of elasticity, and using an allowable bearing
pressure of 4,500 psf, we estimate the total settlement for footings will be less than ¾-inch when
supported on properly compacted native gravel. Depending on variations in foundation loads,
differential settlement within the 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.
4.4 Mat Foundations
Alternatively, the structure can also be supported using a mat foundation bearing on properly
compacted native gravel. Mat foundations, also known as raft foundations, are effective solutions in
areas with heterogeneous soil conditions, as they distribute loads across a larger area, reducing
differential settlement risks. Additionally, a mat foundation provides additional resistance against
uplifting forces due to its mass and continuity. The mat foundation will also support conventional
passenger car traffic and serve as a rigid concrete pavement section. Design parameters are given
Block B Condos – East Babcock Street Engineering Analysis
Bozeman, Montana Page 9
in the recommendations section of this report.
Given the geotechnical conditions and project findings, opting for a mat foundation offers numerous
technical advantages. However, it is crucial to note that the mat foundation's influence reaches
beyond dense gravel into underlying lean clay, potentially leading to greater total settlement
compared to a conventional shallow foundation. Therefore, the conventional shallow foundation is
the recommended option due to this settlement consideration. Based on our experience, the theory
of elasticity, and using a net allowable bearing pressure of 750 psf, we estimate the total settlement
for the mat foundation will be less than 1-inch when supported on properly compacted native gravel.
Depending on variations in foundation loads, differential settlement within the structure should be on
the order of one-half this magnitude.
4.5 Foundation Walls
Foundation walls of the underground parking facility 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 along with the design wall height. 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.
4.6 Exterior Concrete Flatwork
The near surface lean clay soils which may directly underlie exterior concrete flatwork exhibit
elevated plastic properties and are considered marginally expansive. Concrete flatwork underlain
by potentially expansive soils could be susceptible to deformations caused by soil expansion. In
many cases, similar clays do not exhibit significant expansive pressures to impact foundations or
heavily loaded flatwork, but lightly loaded slab-on-grade construction presents a problem because
sufficient dead load cannot be maintained to resist even minor swelling pressures which can be
generated when the subgrade soils moisture is increased. Conventional slab-on-grade construction
consisting of thin base course gravel layer (approximately six inches) directly overlying native clay
soils may experience vertical movements related to the native clay. In many cases the cost
Block B Condos – East Babcock Street Engineering Analysis
Bozeman, Montana Page 10
associated with preventing such movements in exterior application far exceeds the replacement
cost of the exterior concrete should movements be considered excessive; thus, similar construction
is acceptable provided the Owner is willing to accept the risk of potential slab performance issues
for exterior concrete. We are available to discuss options to reduce the risk for exterior concrete if
desired.
According to the provided project plans, little to no pavement will be constructed and it is assumed
that the small entrance to the underground parking facility will be concrete. However, we are
available to provide pavement recommendations if required.
Block B Condos – East Babcock Street Recommendations
Bozeman, Montana Page 11
5.0 RECOMMENDATIONS
5.1 Site Grading and Excavations
1. All topsoil and organic materials, existing fills, asphalt, concrete and related
construction debris should be removed from the proposed building area, pavement
areas, and any areas to receive site grading fills.
2. All fills and backfills 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 and existing fills, are suitable for use as backfills and general site
grading fills on this project. Much of the excavated materials, including near surface
clays, are likely to exhibit elevated moisture contents and the contractor should
anticipate the need for moisture conditioning of these materials prior to reuse in
backfill applications.
All fills 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 fills and backfills 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 Below Foundation and Interior Slabs ................. 98%
b) Foundation Wall Backfill and Below Exterior Flatwork ............... 95%
c) Utility Trench Backfill, To Within 2 Feet of Surface ..................... 95%
d) General Landscaping or Nonstructural Areas ............................. 92%
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, when required, 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
Block B Condos – East Babcock Street Recommendations
Bozeman, Montana Page 12
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.
Native gravels are suitable for use as structural fill when properly moisture
conditioned and processed to remove large cobbles and boulders exceeding six
inches in diameter.
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 for providing
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.
7. Depending on the construction timeline and the potential for fluctuating ground water
levels, the contractor should anticipate the potential to encounter ground water in
any excavation deeper than 15 feet, pending future ground water monitoring results,
and the need for dewatering operations while excavations are underway.
5.2 Conventional Shallow Foundations
The design and construction criteria below should be observed for a shallow foundation system
bearing on native gravels. The construction details should be considered when preparing the project
documents.
8. Both interior and exterior footings should bear on properly compacted native gravels
and should be designed for a maximum allowable soil bearing pressure of 4,500 psf
provided settlements as outlined in the Engineering Analysis are acceptable.
Block B Condos – East Babcock Street Recommendations
Bozeman, Montana Page 13
9. Soils disturbed below the planned depths of footing excavations should either be
recompacted or be replaced with structural fill compacted to the requirements of
Item 2a above.
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. 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, a thin layer of cushion
gravel should be placed and compacted. Suitable materials should conform to
MPWSS Section 02235 and be compacted per Item 2a above.
12. Lateral loads are resisted by sliding friction between the footing base, 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 foundations supported on compacted native
gravels and backfilled with recompacted native soils.
13. A representative of the project’s geotechnical engineer should be retained to
observe all footing excavations and backfill phases prior to the placement of
concrete formwork.
5.3 Mat Foundation
The design and construction criteria below should be observed for conventional mat slab
foundation system. The construction details should be considered when preparing the project
documents.
14. All mat foundations should bear on properly moisture conditioned and compacted
native gravels (Item 2a). We would recommend that a gravel cushion course be
incorporated between the compacted native gravels and the concrete foundation.
This layer should be at least six inches thick, conform to the material properties
outlined in Item 3 above, and be moisture conditioned and compacted to the
requirements of Item 2a above. Mat foundations designed as recommended are
suitable to utilize a maximum allowable bearing pressure of 750 psf provided total
foundation movements of up to one inch and differential movements of up to ½-inch
are acceptable.
15. Soils disturbed below the planned depths of mat slab excavations should be re-
compacted to the requirements of Item 2a above.
Block B Condos – East Babcock Street Recommendations
Bozeman, Montana Page 14
16. Concrete mat slabs should be designed using a modulus of vertical subgrade
reaction no greater than 250 pci when designed and constructed as recommended
above.
5.4 Foundation Walls
The design and construction criteria presented below should be observed for foundation walls which
may retain differential soil heights. The construction details should be considered when preparing
the project documents.
17. Foundation walls which are laterally supported and can be expected to undergo only
a slight amount of deflection should be designed for a lateral earth pressure
computed on the basis of an equivalent fluid unit weight of 60 pcf for backfill
consisting of properly moisture conditioned and compacted native lean clay. For
consideration of seismic forces, a seismic equivalent fluid unit weight of 85 pcf is
appropriate for the increased lateral forces associated with earthquake motions for
similar backfill conditions. If alternative imported materials are planned for use as
backfill, we should be consulted to provide the appropriate values to be utilized in
design.
18. Backfills placed against the sides of the footings and the base of the walls to resist
lateral loads should be placed and compacted per the requirements of Item 2 above.
19. 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.
20. Exterior footing drains are required by the applicable building code for all portions of
the structure which retain soil along the foundation walls (i.e. exterior grade is higher
than interior slab elevation). The intent of this system is to remove water seepage
and infiltrated surface runoff away from foundation soils. 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. It is preferred that drains connect
directly to the on-site storm water system (if included); however, drains sloped to an
interior sump are also acceptable. A typical perimeter foundation drain is shown on
Construction Standard No. 02801-06C.
Block B Condos – East Babcock Street Recommendations
Bozeman, Montana Page 15
A foundation drain system may be omitted when the structure utilizes a mat
foundation design which is completely water-tight and the foundation walls are
designed to resist any hydrostatic forces which may develop based on the results of
future ground water monitoring and the design foundation elevation.
5.5 Interior Slabs and Exterior Concrete Flatwork
21. 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 2b above. A cushion course thickness of six
inches is typically utilized but requirements may vary locally.
Conventional construction, as has been described, is not intended to mitigate
settlement or expansion concerns associated with the subsurface conditions
encountered. In most cases, the cost to repair and/or replace exterior flatwork when
excessive movements occur is far more economical than efforts to mitigate these
movements. However, any exterior flatwork which is especially sensitive to vertical
movement or those which would be a significant cost to replace or have detrimental
impacts to the facility operation should consider additional subsurface improvements
as discussed for interior slabs below.
22. Slabs which will be utilized by vehicle traffic for indoor parking applications should
utilize a minimum concrete thickness of six inches.
23. Cushion course materials utilized beneath slab-on-grade applications should
conform to the requirements outlined in Section 02235 of the Montana Public Works
Standard Specifications (MPWSS). All gradations outlined in this specification are
acceptable for this application.
24. Interior floor slabs which are supported on properly compacted native gravels should
be designed using a modulus of vertical subgrade reaction no greater than 250 pci.
5.6 Continuing Services
Three additional elements of geotechnical engineering service are important to the successful
completion of this project.
25. 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.
Block B Condos – East Babcock Street Recommendations
Bozeman, Montana Page 16
26. 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.
27. During site grading, placement of all fills and backfills should be observed and
tested to confirm that the specified density has been achieved. We recommend that
the Owner maintain control of the construction quality control by retaining the
services of an experienced construction materials testing laboratory. We are
available to provide construction inspection services as well as materials testing of
compacted soils and the placement of Portland cement concrete and asphalt. In the
absence of project specific testing frequencies, TD&H recommends the following
minimum testing frequencies be used:
Compaction Testing
Beneath Column Footings 1 Test per Lift per Footing
Beneath Wall Footings (If Applicable) 1 Test per Lift per 50 LF† of Wall
Beneath Mat Foundation (If Applicable) 1 Test per Lift per 1,500 SF*
Beneath Slabs 1 Test per Lift per 1,500 SF
Foundation Backfill 1 Test per Lift per 100 LF of Wall
* SF = Square Feet † LF = Lineal Feet
Block B Condos – East Babcock Street Summary of Field & Laboratory Studies
Bozeman, Montana Page 17
6.0 SUMMARY OF FIELD & LABORATORY STUDIES
6.1 Field Explorations
The field exploration program was conducted on two separate occasions: February 21, 2024 and
February 29, 2024. A total of two shallow borings were drilled to depths ranging from 8.6 to 9.1 feet
and one deep boring was drilled to a depth of 31.0 feet at the locations shown on Figure 1 to
observe subsurface soil and ground water conditions. The program was conducted on two separate
occasions since access for a conventional truck-mounted drill rig was not possible over the majority
of the property due to existing buildings and site infrastructure, low handing overhead utilities, and
underground utilities limiting potential drilling sites. One boring was advanced through the
subsurface soils using a truck-mounted Longyear BK-81 drill rig equipped with 8-inch O.D.
hollowstem augers in a single area which was accessible for drilling with this equipment. The
remaining two borings were advanced through the subsurface soils using a track-mounted
Geoprobe 66DT drill rig equipped with 6-inch O.D. hollowstem augers and had to be limited in depth
due to the limitation of this equipment. The subsurface exploration and sampling methods used are
indicated on the attached boring logs. The borings were logged by Travis D. Gilskey, PE and Nic C.
Couch, EI of TD&H Engineering. The location of the borings were recorded using a Trimble
handheld GPS unit with an accuracy within 24 inches of the actual field location.
Samples of the subsurface materials were taken using 1⅜-inch I.D. split spoon samplers. The
samplers were driven 18 inches, when possible, into the various strata using a 140-pound drop
hammer falling 30 inches onto the drill rods. For each sample, the number of blows required to
advance the sampler each successive six-inch increment was recorded, and the total number of
blows required to advance the sampler the final 12 inches is termed the penetration resistance (“N-
value”). This test is known as the Standard Penetration Test (SPT) described by ASTM D1586.
Occasionally, the 2 ½-inch I.D. split spoon sampler was used. This represents a modified iteration
of the Standard Penetration Test, where the recorded penetration resistance was decreased by 65
percent to account for the increased surface area and align with the conventional Standard
Penetration Test. 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 borings, which include
soil descriptions, sample types, sample depths, and penetration resistance values, are presented
on Figures 2 through 4.
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 ground water level at the deep boring is indicated on Figure 3. A groundwater
monitoring well was installed following completion of soil sampling at boring B-02 on February 21,
2024, but no ground water data had been collected at the time of this report.
Block B Condos – East Babcock Street Summary of Field & Laboratory Studies
Bozeman, Montana Page 18
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.
Consolidation Measurements of the percent compression experienced
under various loading conditions. For use in settlement
analysis and foundation design.
The laboratory testing program for this project consisted of 18 moisture-visual analyses, 6 sieve
(grain-size distribution) analyses, and 2 Atterberg Limits analyses. The results of the water content
analyses are presented on the borings logs, Figures 2 through 4. The grain-size distribution curves
and Atterberg limits are presented on Figures 5 through 12. In addition, one consolidation test was
performed and is presented on Figure 13.
Block B Condos – East Babcock Street Limitations
Bozeman, Montana Page 19
7.0 LIMITATIONS
This report has been prepared in accordance with generally accepted geotechnical engineering
practices in this area for use by the client for design purposes. The findings, analyses, and
recommendations contained in this report reflect our professional opinion regarding potential
impacts the subsurface conditions may have on the proposed project and are based on site
conditions encountered. Our analysis assumes that the results of the exploratory borings 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 analyses. 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 fills, 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.
Block B Condos – East Babcock Street Limitations
Bozeman, Montana Page 20
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 borings and presented in discussions of subsurface conditions
included in this report.
Prepared by: Reviewed by:
Travis D. Gilskey PE Craig R. Nadeau PE & Principal
Geotechnical Engineer Geotechnical Manager
TD&H ENGINEERING TD&H ENGINEERING
??
?
B-3B-2
B-1
³
0 30 6015
Feet
?
PROJECT LOCATION
BORING LOCATION 406.761.3010 • tdhengineering.comService Layer Credits: NatGeo_World_Map: National Geographic, Esri, Garmin, HERE, UNEP-WCMC, USGS, NASA, ESA, METI,NRCAN, GEBCO, NOAA, increment P Corp.BORE HOLE LOCATION MAP1800 RIVER DR. NO. • GREAT FALLS, MONTANA 59401K:\2023\B23-048 Rouse Block B Condos\05_DESIGN (Tech & Reports)\GEOTECH\BOREHOLE MAP\B23-048 BOREHOLE MAP.2024.03.06.aprxB23-048 BOREHOLE MAP.2024.03.06.APRX
DRAWN BY:
DESIGNED BY:
QUALITY CHECK:
DATE DRAWN:
JOB NO.:
FIELDBOOK:REVDATEREVISIONCRN
1BOZEMAN, MONTANAROUSE BLOCK B CONDOS GEOTECHNICAL SERVICES DRW
03/06/2024
B23-048-002
FIGURE
0
3
6
9
12
15
18
21
TOPSOIL: Lean CLAY - appears firm to stiff, black to
dark brown, moist, organics
Lean CLAY - stiff, brown, moist, trace sand, trace
roots
Lean CLAY with Sand - stiff, light tan, moist
Clayey GRAVEL with Sand - loose to medium dense,
light brown to brown, moist
Bottom of Boring
1.0
3.0
4.5
9.1
Ground
water
not
encoun-
tered
5-6-6
N=12
5-5-5
N=10
6-12-21
N=33
6-13-16
N=29
LEGEND LOG OF SOIL BORING B-01SPT blows per foot Atterberg Limits
Field Moisture content Block B Condos
East Babcock Street
Bozeman, Montana
Groundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Nic C. Couch, EI
2-1/2-inch I.D. split spoon Drilled by:TD&H Engineering
Track-mounted Geoprobe 66DT with 6-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
2/29/2024 B23-048-002
No sample recovery Figure No. 2
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Light Vegetation and Topsoil
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 1
0
3
6
9
12
15
18
21
GRAVEL SURFACING PAVEMENT: Poorly-Graded
GRAVEL with Sand - appears medium dense, dark
brown, wet
Sandy Lean CLAY - soft, dark brown, moist,
homogeneous, low plasticity
Clayey SAND - very loose, dark brown, moist, fine,
homogeneous
Lean CLAY with Sand - soft, brown, moist,
homogeneous, low plasticity
Poorly-Graded GRAVEL with Clay and Sand - loose
to very dense, light brown, dry, coarse, subrounded
and subangular, slight oxidation
- wet
0.3
4.5
6.2
7.0
2-2-2
N=4
1-1-1
N=2
21-18-
27 N=
45
13-12-7
N=19
50/2"
41-50/
4"
50/2"
91/10"
LEGEND LOG OF SOIL BORING B-02SPT blows per foot Atterberg Limits
Field Moisture content Block B Condos
East Babcock Street
Bozeman, Montana
Groundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Travis D. Gilskey, PE
2-1/2-inch I.D. split spoon Drilled by:Haztech Drilling
Truck-mounted Longyear BK-81 with 4.25-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
2/21/2024 B23-048-002
No sample recovery Figure No. 3
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Gravel Surfacing Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
1 of 2
24
27
30
33
36
39
42
Sandy Lean CLAY - stiff, tan mottled with white,
moist, low plasticity, trace gravel
Bottom of Boring
29.0
31.0
14-26-
33/4"
7-6-8
N=14
59/10"
LEGEND LOG OF SOIL BORING B-02SPT blows per foot Atterberg Limits
Field Moisture content Block B Condos
East Babcock Street
Bozeman, Montana
Groundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Travis D. Gilskey, PE
2-1/2-inch I.D. split spoon Drilled by:Haztech Drilling
Truck-mounted Longyear BK-81 with 4.25-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
2/21/2024 B23-048-002
No sample recovery Figure No. 3
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Gravel Surfacing Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
2 of 2
0
3
6
9
12
15
18
21
ASPHALT PAVEMENT - 4" thick
BASE COURSE: Poorly-Graded GRAVEL with Clay
and Sand - appears medium dense to dense, dark
brown, moist
Sandy Lean CLAY - firm to very stiff, dark brown to
brown, moist, trace gravel
- See Figure 13 for Consolidation Test Report
Clayey GRAVEL with Sand - very dense, light
brown, moist
Bottom of Boring
0.3
0.7
7.7
8.6
Ground
water
not
encoun-
tered
PUSH
4-9-13
N=22
15-37-
47 N=
84
T
84
LEGEND LOG OF SOIL BORING B-03SPT blows per foot Atterberg Limits
Field Moisture content Block B Condos
East Babcock Street
Bozeman, Montana
Groundwater Level
Grab/composite sample
1-3/8-inch I.D. split spoon Logged by:Nic C. Couch, EI
2-1/2-inch I.D. split spoon Drilled by:TD&H Engineering
Track-mounted Geoprobe 66DT with 6-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic
3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate
boundaries between soil types. Actual boundaries
may be gradual or transitional.
2/29/2024 B23-048-002
No sample recovery Figure No. 4
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
1 of 1
Tested By: WJC Checked By:
Particle Size Distribution Report
ASTM C117 & C136
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 45.1 6.7 2.9 11.6 19.5 14.26 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Test Results (ASTM C117 & C136)Material Description
Atterberg Limits
Coefficients
Classification
Test Remarks
Sample Date:Location: B-1
Sample Number: A-29590 Depth: 5.0 - 6.5 ft
Client:
Project:
Project No:Figure
Sieve Size
or
Diam. (mm.)
Finer
(%)
Spec.*
(%)
Out of
Spec.
(%)
Pct.
of
Fines
Clayey GRAVEL with Sand
1 1/2"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
70.9
54.9
54.9
53.8
48.2
45.3
41.4
33.7
25.9
21.7
19.3
14.2
Not Tested Not Tested Not Tested
33.2662 31.1037 21.7973
6.0491 0.3284 0.0838
GC
Report No. A-29590-206
Report Date: 3-5-2024
F.M.=4.68
2-29-2024
S2K Miller Babcock, LLC
Block B Condos
East Babcock Street
B23-048-002
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*(no specification provided)
5
Tested By: WJC Checked By:
Particle Size Distribution Report
ASTM C117 & C136
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 26.9 28.0 9.9 12.7 10.1 12.46 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Test Results (ASTM C117 & C136)Material Description
Atterberg Limits
Coefficients
Classification
Test Remarks
Sample Date:Location: B-1 & B-3
Sample Number: A-29591COMP Depth: 7.5 - 10.5 ft
Client:
Project:
Project No:Figure
Sieve Size
or
Diam. (mm.)
Finer
(%)
Spec.*
(%)
Out of
Spec.
(%)
Pct.
of
Fines
Clayey GRAVEL with Sand
3"
1.5"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
96.2
81.9
73.1
62.8
56.7
45.1
35.2
27.9
22.5
19.0
17.2
16.1
12.4
Not Tested Not Tested Not Tested
31.1673 27.5947 11.2081
6.5219 1.0975 0.1231
GC
Report No. A-29591COMP-206
Report Date: 3-5-2024
F.M.=5.00
2-29-2024
S2K Miller Babcock, LLC
Block B Condos
East Babcock Street
B23-048-002
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*(no specification provided)
6
Tested By: WJC Checked By:
Particle Size Distribution Report
ASTM C117 & C136
PERCENT FINER0
10
20
30
40
50
60
70
80
90
100
GRAIN SIZE - mm.
0.00010.0010.010.1110100
% +3"Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 0.0 0.2 0.4 22.6 52.4 24.46 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Test Results (ASTM C117 & C136)Material Description
Atterberg Limits
Coefficients
Classification
Test Remarks
Sample Date:Location: B-02
Sample Number: A-29548 Depth: 5.0 - 6.2 ft
Client:
Project:
Project No:Figure
Sieve Size
or
Diam. (mm.)
Finer
(%)
Spec.*
(%)
Out of
Spec.
(%)
Pct.
of
Fines
Clayey SAND
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
99.8
99.4
95.1
76.8
55.4
44.1
37.9
24.4
Not Tested Not Tested Not Tested
0.6596 0.5501 0.2810
0.2148 0.1029
SC
Report No. A-29548-206
Report Date: 2-28-2024
F.M.=1.14
2-21-2024
S2K Miller Babcock, LLC
Block B Condos
East Babcock Street
B23-048-002
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*(no specification provided)
7
Tested By: WJC Checked By:
Particle Size Distribution Report
ASTM C117 & C136
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 25.5 25.8 11.2 17.5 9.7 10.36 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Test Results (ASTM C117 & C136)Material Description
Atterberg Limits
Coefficients
Classification
Test Remarks
Sample Date:Location: B-02
Sample Number: A-29554 Depth: 25.0 - 26.5 ft
Client:
Project:
Project No:Figure
Sieve Size
or
Diam. (mm.)
Finer
(%)
Spec.*
(%)
Out of
Spec.
(%)
Pct.
of
Fines
Poorly-Graded GRAVEL with Clay and Sand
1.5"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
78.8
74.5
66.2
60.0
48.7
37.5
27.8
20.0
16.3
14.5
13.5
10.3
Not Tested Not Tested Not Tested
31.9696 29.2366 9.5344
5.2016 1.0320 0.1962
GP-GC
Report No. A-29554-206
Report Date: 3-1-2024
F.M.=4.91
2-21-2024
S2K Miller Babcock, LLC
Block B Condos
East Babcock Street
B23-048-002
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*(no specification provided)
8
Tested By: WJC Checked By:
Particle Size Distribution Report
ASTM C117 & C136
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 3.8 1.9 6.5 29.3 58.56 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Test Results (ASTM C117 & C136)Material Description
Atterberg Limits
Coefficients
Classification
Test Remarks
Sample Date:Location: B-02
Sample Number: A-29555 Depth: 30.0 - 31.5 ft
Client:
Project:
Project No:Figure
Sieve Size
or
Diam. (mm.)
Finer
(%)
Spec.*
(%)
Out of
Spec.
(%)
Pct.
of
Fines
Sandy Lean CLAY
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
98.9
97.8
96.2
94.3
91.6
87.8
83.2
78.7
75.1
58.5
19 36 17
0.6116 0.2994 0.0797
CL A-6(7)
Report No. A-29555-206
Report Date: 2-28-2024
F.M.=0.68
S2K Miller Babcock, LLC
Block B Condos
East Babcock Street
B23-048-002
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*(no specification provided)
9
Tested By: WJC Checked By:
Particle Size Distribution Report
ASTM C117 & C136
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 8.2 4.1 5.9 21.2 60.66 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Test Results (ASTM C117 & C136)Material Description
Atterberg Limits
Coefficients
Classification
Test Remarks
Sample Date:Location: B-3
Sample Number: A-29594 Depth: 5.0 - 6.7 ft
Client:
Project:
Project No:Figure
Sieve Size
or
Diam. (mm.)
Finer
(%)
Spec.*
(%)
Out of
Spec.
(%)
Pct.
of
Fines
Sandy Lean CLAY
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#80
#100
#200
100.0
98.4
95.7
91.8
87.7
84.4
81.8
78.3
74.8
71.8
60.6
20 40 20
3.3437 0.9961
CL A-6(10)
Report No. A-29594-206
Report Date: 3-5-2024
F.M.=1.04
2-29-2024
S2K Miller Babcock, LLC
Block B Condos
East Babcock Street
B23-048-002
PL= LL= PI=
D90= D85= D60=
D50= D30= D15=
D10= Cu= Cc=
USCS= AASHTO=
*(no specification provided)
10
Tested By: JB 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 CONTENT34.4
34.8
35.2
35.6
36
36.4
36.8
37.2
37.6
38
38.4
NUMBER OF BLOWS
5 6 7 8 9 10 20 25 30 40
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
Project No. Client:Remarks:
Project:
Location: B-02
Sample Number: A-29555 Depth: 30.0 - 31.5 ft
Figure
Sandy Lean CLAY 36 19 17 87.8 58.5 CL
B23-048-002 S2K Miller Babcock, LLC
11
Report No. A-29555-207
Report Date: 2-29-2024Block B Condos
East Babcock Street
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 CONTENT38.2
38.6
39
39.4
39.8
40.2
40.6
41
41.4
41.8
42.2
NUMBER OF BLOWS
5 6 7 8 9 10 20 25 30 40
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
Project No. Client:Remarks:
Project:
Location: B-3
Sample Number: A-29594 Depth: 5.0 - 6.7 ft
Figure
Sandy Lean CLAY 40 20 20 81.8 60.6 CL
B23-048-002 S2K Miller Babcock, LLC
12
Report No. A-29594-207
Report Date: 3-6-2024Block B Condos
East Babcock Street
Tested By: CRN Checked By:
CONSOLIDATION TEST REPORT
Percent Strain4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
Applied Pressure - psf
100 1000 10000
Natural Dry Dens.LL PI Sp. Gr.
Overburden Pc Cc Cr Initial Void
Saturation Moisture
(pcf) (psf) (psf) Ratio
84.2 % 20.5 % 101.7 40 20 2.7 740 1665 0.08 0.01 0.657
Sandy Lean CLAY CL A-6(10)
B23-048- S2K Miller Babcock, LLC
Block B Condos
East Babcock Street
Report No. A-29594-219
Report Date: 3-4-2024
13
MATERIAL DESCRIPTION USCS AASHTO
Project No. Client:Remarks:
Project:
Location: B-3 Depth: 5.0 - 6.7 ft Sample Number: A-29594
Figure
QUALITY CHECK:
DESIGNED BY:
DRAWN BY:
CAD NO.
JOB NO.
DATE:
02801-06C
Engineering
tdhengineering.com
CONSTRUCTION STANDARD NO. 02801-06C
PERIMETER FOUNDATION DRAIN
RLT
CRN
MMJ
5/21/15
FIGURE