HomeMy WebLinkAbout016 - Appendix L.2 - Geotech Report Addendum #1
MONTANA | WASHINGTON | IDAHO | NORTH DAKOTA | PENNSYLVANIA
406.586.0277
tdhengineering.com
234 E Babcock St, Suite 3
Bozeman, MT 59715
June 25, 2024
Mr. Kerry Nickerson
S2K Miller Holding, LLC
4643 S Ulster St, Ste. 1500
Denver, CO 80237
RE: CANOPY HOTEL
BOZEMAN, MONTANA
GEOTECHNICAL ADDENDUM #1
TD&H ENGINEERING JOB NO. B23-017-003
Dear Mr. Nickerson,
Based on discussions with your design team, we understand that Allied Engineering
Services, Inc. performed a geophysical investigation of the property in April of 2024 to
assess the seismic site class for the property based on alternative methods. It is our
understanding that you desire TD&H to provide an opinion regarding the suitability of the
results provided by Allied Engineering. The seismic Site Class provided in our geotechnical
report utilized standard penetration test (SPT) data within the depth of our investigation
along with supporting well log information to the requisite 100-ft depth to assess the
seismic site class in accordance with IBC methods. While our classification approach is an
acceptable methodology, a geophysical study is a more accurate method as it provides
direct measurements of shear wave velocity (Vs) within the 100-ft depth. Geophysical
methods, such as the Multi-Channel Analysis of Surface Waves (MASW) utilized by Allied,
is a specialized testing method that yields a continuous profile of shear wave velocity with
depth, offering a detailed and precise subsurface characterization.
In our opinion, the seismic Site Class designations as identified in the geophysical report
prepared by Allied is appropriate for use in lieu of the site class provided in our original
report, as the MASW method supersedes our SPT correlation method. However, TD&H did
not oversee the geophysical study completed by Allied and provides no guarantee or
assurance regarding the accuracy of their results.
The intent of this addendum is to summarize additional information provided from work
performed by others. It shall serve as an addendum to the original geotechnical report,
dated March 2024, and is not to replace the overall engineering assessment or
recommendations outside the changes specifically noted above. We trust that the
additional information above is adequate to allow the design team to continue their work on
this project. Please let us know if there are any additional questions or concerns.
Sincerely,
June 25, 2024 PAGE NO. 2
tdhengineering.com
Nic Couch EI Craig Nadeau PE & Principal
Geotechnical Engineer Geotechnical Manager
TD&H ENGINEERING TD&H ENGINEERING
APPENDIX: MASW SEISMIC SURVEY (ALLIED ENGINEERING, INC)
J:\2023\B23-017 32 South Rouse\05_DESIGN (Tech & REPORTS)\GEOTECH\FINAL\SITE CLASS
ADDENDUM\B23-017 32 SOUTH ROUSE ADDENDUM #1.DOC
Civil Engineering ● Geotechnical Engineering ● Land Surveying ● Construction Services
Corporate Office
32 Discovery Drive
Bozeman, MT 59718
Ph: (406) 582-0221
Fax: (406) 582-5770
www.alliedengineering.com
April 30, 2024
Miller Properties Group, LLC
4643 South Ulster Street, Suite 1500
Denver, CO 80237
Email: kerry.nickerson@millerglobal.com
RE: MASW Seismic Survey, 32 South Rouse
Dear Mr. Nickerson:
This report presents our seismic evaluation of the 32 South Rouse site in Bozeman, Montana.
The information provided herein is based on a review of geologic maps and geotechnical data
for the project area, an on-site geophysical investigation of the property, and previous
experience gained during our involvement with similar developments in and around Bozeman.
DESCRIPTION OF THE PROPERTY
The 32 South Rouse site is a series of 3 adjacent developed properties totaling 0.882 acres
located immediately northeast of the intersection of East Babcock Street and South Rouse
Avenue in Bozeman, MT. The legal description of the properties are Lots 18 - 21 of Rouse 1st
Add, Block A, located in Section 7, Township 2 South, Range 6 East, Principal Meridian Montana,
Gallatin County, Montana. The property is bound to the west, north, and south by public Right
of Way (ROW), and to the east by an unimproved property (see Figures 1 and 2 for site location
maps). Presently, the Salvation Army building is found on the westernmost subject property
with adjacent parking to the south and east.
GEOLOGY AND SUBSURFACE CONDITIONS
The geologic map for the area prepared by Lonn and English (2002) indicates the site is
underlain by alluvium of modern channels and flood plains (Qal). An excerpt from the geology
map is provided as part of Figure 4. This interpretation is consistent with the borings logged by
TD&H in 2023 and 2024, which encountered topsoil, fill, or improved surfaces overlying about 5
to 10 feet of soft to medium stiff lean clay. These fine-grain soils were underlain by course-
grained sands and gravels which were interbedded with seams/layers of very stiff lean clay and
clayey sand. These conditions extended to the depth of the borings (up to 50 feet).
Geologic mapping indicates the alluvium is underlain by the Upper Tertiary Sixmile Creek
Formation (Tsc & Tscg). In the Bozeman area, this formation is primarily a course-grained
brown-to-gray conglomerate. The depth of this older formation is unknown at the site,
S2K Miller Babcock, LLC
April 30, 2024
32 South Rouse MASW
AESI Project: 24-057
32 Discovery Drive . Bozeman, Montana 59718 . Ph: (406) 582-0221 . Fax: (406) 582-5770 Page 2
although there is a possibility the borings may have just been touching into it at the bottom of
the deeper explorations.
METHODOLOGY
A geophysical survey was conducted on 20 April 2024, by Jesse Moyles, EI, and Erik
Schnaderbeck, PE, both of whom are geotechnical engineers with AESI. The survey was
conducted via Multi-Channel Analysis of Surface Waves (MASW) wherein 24 vertically polarized
and calibrated 4.5-Hz geophones manufactured by Seismic Source were used to analyze Raleigh
Wave propagation across the site.
For this study, the geophones were connected via a 24-channel spread cable to a DAQlink 4
MASW Seismograph, also manufactured by Seismic Source. The geophones were deployed
linearly, east to west (see Figure 3), on a 7-foot interval, for a total geophone array length of
161 feet. The array was located near the southern property boundary, with the first receiver
located at approximately 45.67846, -111.03134, and the last receiver located at approximately
45.67844, -111.03084. Each geophone was firmly seated into the soil utilizing a spike
connection or attached to a steel sled for improved surfaces (i.e., asphalt or concrete). Surface
waves were generated with a 20-lb sledgehammer impacting a rigid plastic or hard rubber
strike plate. The sledgehammer was instrumented and connected to the seismograph via a
hammer switch and cable. The acquisition time was set to 4 seconds with a 0.5 millisecond
sample interval. Shots were taken at 1, 6, 12, and 24 receiver spacings on each side of the array,
and stacks of 5 shots were recorded and stored in SEG-2 format for further processing.
DATA PROCESSING
Data were processed utilizing the ParkSEIS 3.0 Auto automated MASW processing software
from Park Seismic, LLC. The SEG-2 files were pre-loaded with acquisition parameters (shot and
receiver spacings) which were verified upon processing. Dispersion images were generated for
each SEG-2 file and subsequently stacked to produce a single-best image (Figure R1). Some
automated data smoothing, gain adjustment, and normalization were also conducted within
the ParkSEIS software to enhance the overall quality of the dispersion image.
S2K Miller Babcock, LLC
April 30, 2024
32 South Rouse MASW
AESI Project: 24-057
32 Discovery Drive . Bozeman, Montana 59718 . Ph: (406) 582-0221 . Fax: (406) 582-5770 Page 3
Figure R1 – 32 South Rouse dispersion image.
The acquired dispersion image demonstrates well-defined amplitudes for frequencies between
approximately 8 and 32 Hz. Although amplitudes are much smaller beyond 32 Hz, a
fundamental mode is still discernable at frequencies as high as about 43 Hz.
Figure R2 – 32 South Rouse dispersion curve extraction.
Once boundary conditions were established, a dispersion curve was extracted based on the
highest amplitudes within the pre-defined boundaries. The extracted dispersion curve is shown
in Figure R2.
S2K Miller Babcock, LLC
April 30, 2024
32 South Rouse MASW
AESI Project: 24-057
32 Discovery Drive . Bozeman, Montana 59718 . Ph: (406) 582-0221 . Fax: (406) 582-5770 Page 4
INVERSION
A one-dimensional shear wave velocity profile was produced by inversion analysis utilizing the
ParkSEIS 3.0 Auto software. For this analysis, layer properties were defined based on the boring
information provided by TD&H and our interpretation of the geologic information. Multiple
iterations were conducted until a best-fit model was produced. In this case, the shear wave
velocity profile produces a modeled dispersion curve that is a 96.5 percent fit to the measured
curve. Red-dot measured vs blue-dot modeled dispersion curves are shown in Figure R3.
Figure R3 – 32 South Rouse Shear Wave Velocity Profile.
As shown in Figure R3, the modeled shear wave velocity profile (solid blue line) increases from
about 500 ft/s at the surface to approximately 1,300 ft/s at a depth of 10 feet. Measured shear
wave velocities then decrease slightly before increasing to about 1,700 ft/s at a depth of
approximately 50 feet. Beyond 70 feet, shear wave velocities jumped to 2,250 ft/s, which
extended to a depth of over 100 feet.
The estimated velocity profile provided above is generally consistent with both the
geotechnical information provided by TD&H and our interpretation of the available geologic
information.
SEISMIC SITE CLASSIFICATION
Per ASCE 7-16 and ASCE 7-22, and barring any special circumstances, seismic site classification
is determined based on the average shear wave velocity as measured from the ground surface
to a depth of 100 feet. Moreover, ASCE 7-22 only allows the assignment of Site Classes A and B
S2K Miller Babcock, LLC
April 30, 2024
32 South Rouse MASW
AESI Project: 24-057
32 Discovery Drive . Bozeman, Montana 59718 . Ph: (406) 582-0221 . Fax: (406) 582-5770 Page 5
based on measured shear wave velocities and not velocities correlated from other data (CPT,
SPT, etc.). The MASW survey of 20 April 2024 fulfills these requirements by directly measuring
in-situ shear wave velocities on site.
As demonstrated in Figure R4, the average estimated shear wave velocity at this site measured
from the ground surface to a depth of 100 feet (Vs100) is approximately 1,274 ft/s, as calculated
according to the National Earthquake Hazard Reduction Program and ASCE standards. The
subject property is therefore assigned a Seismic Site Classification “C” per ASCE-7-16 and a
Seismic Site Classification “CD” per ASCE 7-22. Per ASCE 7-16, the transition from Site Class D
to Site Class C is 1,200 ft/s.
Figure R4 – 32 South Rouse Seismic Site Classification (ASCE 7-16).
Site-specific seismic loading and response spectra can be obtained from the web-based Hazard
Tool provided by the ASCE (https://ascehazardtool.org/). The user is required to input
parameters that are used to obtain site-specific seismic information. The user will need to
specify the applicable standard (ASCE 7-16 or ASCE 7-22), the occupancy risk category, the
seismic site classification, and the site location.
LIST OF FIGURES
FFiigguurree 11 –– VViicciinniittyy MMaapp
FFiigguurree 22 –– QQuuaaddrraannggllee MMaapp
FFiigguurree 33 –– MMAASSWW AArrrraayy
FFiigguurree 44 –– GGeeoollooggyy MMaapp
FIGURECivil Engineering
Geotechnical Engineering
Land Surveying
32 DISCOVERY DRIVE . BOZEMAN, MT 59718
PHONE (406) 582-0221 . FAX (406) 582-5770
www.alliedengineering.com
32 SOUTH ROUSE MASW
VICINITY MAP
BOZEMAN, MONTANA
1
N
FIGURECivil Engineering
Geotechnical Engineering
Land Surveying
32 DISCOVERY DRIVE . BOZEMAN, MT 59718
PHONE (406) 582-0221 . FAX (406) 582-5770
www.alliedengineering.com
32 SOUTH ROUSE MASW
QUADRANGLE MAP
BOZEMAN, MONTANA
2
N
FIGURECivil Engineering
Geotechnical Engineering
Land Surveying
32 DISCOVERY DRIVE . BOZEMAN, MT 59718
PHONE (406) 582-0221 . FAX (406) 582-5770
www.alliedengineering.com
32 SOUTH ROUSE MASW
MASW ARRAY
BOZEMAN, MONTANA
3
N
FIGURECivil Engineering
Geotechnical Engineering
Land Surveying
32 DISCOVERY DRIVE . BOZEMAN, MT 59718
PHONE (406) 582-0221 . FAX (406) 582-5770
www.alliedengineering.com
32 SOUTH ROUSE MASW
GEOLOGY MAP
BOZEMAN, MONTANA
4
N
LIST OF APPENDICES
AAppppeennddiixx AA –– GGeeootteecchhnniiccaall BBoorriinnggss
AAppppeennddiixx BB –– LLiimmiittaattiioonnss
APPENDIX A
GGeeootteecchhnniiccaall BBoorriinnggss
?
?
?B-4
B-3
B-5
B-1
B-2
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\B23-017 32 South Rouse\05_DESIGN (Tech & Reports)\GEOTECH\BOREHOLE MAP\B23-017 BOREHOLE MAP.2024.03.05.aprxB23-017 BOREHOLE MAP.2024.03.05.APRX
DRAWN BY:
DESIGNED BY:
QUALITY CHECK:
DATE DRAWN:
JOB NO.:
FIELDBOOK:REVDATEREVISIONCRN
1BOZEMAN, MONTANA32 SOUTH ROUSE GEOTECHNICAL SERVICES DRW
03/05/2024
B23-017-003
FIGURE
0
4.5
9
13.5
18
22.5
27
31.5
TOPSOIL: Lean CLAY with Sand - very soft to soft,
dark brown to black, moist, organics, trace gravel
Sandy Lean CLAY - soft, brown, moist, organics to 4
feet
- See Figure 9 for consolidation test result
Poorly-Graded GRAVEL with Clay and Sand -
medium dense, brown, moist, some red and rusty
brown throughout
Clayey GRAVEL with Sand - medium dense to very
dense, brown, moist to wet, some red / light brown /
white throughout
No Recovery
Bottom of Boring (Groundwater Monitoring Well
Installed Following Completion)
Screen from 24.0 to 14.0 feet
Sand from 24.0 to 10.0 feet
Bentonite from 10.0 to 1.5 feet
Sand, Concrete, and Well Cover from 1.5 to 0.0 feet
3.8
6.8
9.0
24.0
2-1-2
N=3
2-2-2
N=4
PUSH
5-5-6
N=11
5-4-9
N=13
19-32-
50/0.4
25-50/
0.4
50/0.0
T
82/0.9
50/0.4
50/0.0
LEGEND LOG OF SOIL BORING B-01SPT blows per foot Atterberg Limits
Field Moisture content 32 South Rouse Avenue
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: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.
June 7, 2023 B23-017-001
No sample recovery Figure No.2
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Sodded Lawn
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
4.5
9
13.5
18
22.5
27
31.5
TOPSOIL: Lean CLAY with Sand - appears soft to
firm, dark brown to black, moist, organics
FILL: Clayey GRAVEL with Sand - relatively dense,
dark brown, moist, cobbles, chunk of concrete
Sandy Lean CLAY - soft, brown, moist
Clayey SAND - medium dense, brown, moist
Poorly-Graded GRAVEL with Clay and Sand -
medium dense to very dense, brown, moist
Clayey GRAVEL with Sand - very dense, brown,
moist to wet
- Large cobbles / boulders, and some creme brown
below 15 feet
No Recovery
- Brown to dark gray and some maroon below 25 feet
Bottom of Boring (Groundwater Monitoring Well
Installed Following Completion)
Screen from 25.0 to 15.0 feet
Sand from 25.0 to 10.0 feet
Bentonite from 10.0 to 1.5 feet
Sand, Concrete, and Well Cover from 1.5 to 0.0 feet
1.0
1.5
4.5
6.0
9.5
26.4
3-3-3
N=6
6-7-7
N=14
16-27-
50/0.4
17-42-
23 N=
65
24-42-
50/0.4
50/0.33
35-47-
50/0.4
77/0.9
65
92/0.9
50/0.33
97/0.9
LEGEND LOG OF SOIL BORING B-02SPT blows per foot Atterberg Limits
Field Moisture content 32 South Rouse Avenue
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: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.
June 8, 2023 B23-017-001
No sample recovery Figure No.3
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Sodded Lawn
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
4.5
9
13.5
18
22.5
27
31.5
Asphalt Pavement - 4" thick
Base Coarse - Poorly-graded GRAVEL with Sand -
brown, moist, coarse, subrounded
LEAN CLAY with Sand - medium stiff to stiff, dark
brown, moist, medium plasticity, lenses of sand
Poorly-graded GRAVEL with Sand - dense to very
dense, brown, moist, coarse, subrounded and
subangular
Clayey SAND with Gravel - very dense, brown, wet,
coarse
Silty SAND - medium dense, light brown, wet, fine,
homogeneous, moderate oxidation
Poorly-graded SAND with Clay and Gravel - dense,
brown, wet, medium grained, moderate oxidation
0.3
0.8
8.7
24.0
28.0
32.0
3-3-4
N=7
4-4-4
N=8
5-7-8
N=15
11-11-
14 N=
25
23-32-
29 N=
61
45-50/
1"
44-50/
5.5"
8-12-17
N=29
61
95/7"
94/11.5"
LEGEND LOG OF SOIL BORING B-03SPT blows per foot Atterberg Limits
Field Moisture content 32 South Rouse Avenue
Bozeman, MontanaGroundwater 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:Paul Brey with 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 B23-017-001
No sample recovery Figure No.4
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
1 of 2
36
40.5
45
49.5
54
58.5
63
Clayey SAND - dense, light brown, wet, fine,
homogeneous, moderate oxidation
Poorly-graded GRAVEL with Sand - very dense,
brown, wet, coarse, subrounded and subangular
Poorly-graded SAND with Clay - dense, light brown,
wet, medium grained, moderate oxidation, trace of
gravel
Bottom of Boring
37.0
44.5
47.0
51.2
13-21-
14 N=
35
6-11-19
N=30
13-50/
3"
13-17-
20 N=
37
63/9"
LEGEND LOG OF SOIL BORING B-03SPT blows per foot Atterberg Limits
Field Moisture content 32 South Rouse Avenue
Bozeman, MontanaGroundwater 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:Paul Brey with 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 B23-017-001
No sample recovery Figure No.4
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
2 of 2
0
4.5
9
13.5
18
22.5
27
31.5
Asphalt Pavement - 4" thick
Base Coarse - Poorly-graded GRAVEL with Sand -
brown, moist, coarse, subrounded
Poorly-graded SAND with Clay - loose, dark brown,
moist, fine
Poorly-graded GRAVEL with Sand - medium dense to
very dense, brown, moist, coarse, subrounded
- light brown
- tan
- wet
Bottom of Boring
0.3
1.1
6.0
26.0
3-2-3
N=5
3-5-6
N=11
6-6-9
N=15
5-10-11
N=21
21-29-
33 N=
62
30-40-
50/4"
23-33-
38 N=
71
62
90/10"
71
LEGEND LOG OF SOIL BORING B-04SPT blows per foot Atterberg Limits
Field Moisture content 32 South Rouse Avenue
Bozeman, MontanaGroundwater 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:Paul Brey with 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.
2/19/2024 B23-017-001
No sample recovery Figure No.5
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Asphalt Pavement
SURFACE ELEVATION:Not Measured
DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT
0 10 20 30 40 50
= BLOWS PER FOOT
= MOISTURE CONTENT
1 of 1
0
4.5
9
13.5
18
22.5
27
31.5
Concrete Pavement - 3 1/2" thick
Base Coarse - Poorly-graded GRAVEL with Sand -
brown, moist, coarse, subrounded
LEAN CLAY with Sand - stiff, dark brown, moist,
medium plasticity, lense of sand
Poorly-graded GRAVEL with Sand - medium dense to
very dense, brown, moist, coarse, subrounded and
subangular, scattered cobbles
- wet
0.3
1.0
3.8
18-7-4
N=11
2-3-7
N=10
9-7-6
N=13
4-7-6
N=13
10-14-
15 N=
29
50/4"
33-41-
50/5"
33-48-
43 N=
91
42-38-
50/5"
50/4"
91/11"
91
88/11"
LEGEND LOG OF SOIL BORING B-05SPT blows per foot Atterberg Limits
Field Moisture content 32 South Rouse Avenue
Bozeman, MontanaGroundwater 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:Paul Brey with 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.
2/20/2024 B23-017-001
No sample recovery Figure No.6
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Concrete 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
36
40.5
45
49.5
54
58.5
63
Poorly-graded SAND with Clay and Gravel - dense,
brown, wet, fine and medium grained
Sandy LEAN CLAY - very stiff, tan, moist, medium
plasticity, homogeneous
Bottom of Boring
34.0
38.0
51.2
8-16-33
N=49
4-5-12
N=17
6-6-8
N=14
26-11-
15 N=
26
LEGEND LOG OF SOIL BORING B-05SPT blows per foot Atterberg Limits
Field Moisture content 32 South Rouse Avenue
Bozeman, MontanaGroundwater 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:Paul Brey with 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.
2/20/2024 B23-017-001
No sample recovery Figure No.6
SheetGRAPHICLOGSOIL DESCRIPTION
SURFACE:Concrete 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
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APPENDIX B
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LIMITATIONS OF YOUR GEOTECHNICAL REPORT
GEOTECHNICAL REPORTS ARE PROJECT AND CLIENT SPECIFIC
Geotechnical investigations, analyses, and recommendations are project and client specific. Each project
and each client have individual criterion for risk, purpose, and cost of evaluation that are considered in
the development of scope of geotechnical investigations, analyses and recommendations. For example,
slight changes to building types or use may alter the applicability of a particular foundation type, as can a
particular client’s aversion or acceptance of risk. Also, additional risk is often created by scope‐of service
limitations imposed by the client and a report prepared for a particular client (say a construction
contractor) may not be applicable or adequate for another client (say an architect, owner, or developer
for example), and vice‐versa. No one should apply a geotechnical report for any purpose other than that
originally contemplated without first conferring with the consulting geotechnical engineer. Geotechnical
reports should be made available to contractors and professionals for information on factual data only
and not as a warranty of subsurface conditions, such as those interpreted in the exploration logs and
discussed in the report.
GEOTECHNICAL CONDITIONS CAN CHANGE
Geotechnical conditions may be affected as a result of natural processes or human activity. Geotechnical
reports are based on conditions that existed at the time of subsurface exploration. Construction
operations such as cuts, fills, or drains in the vicinity of the site and natural events such as floods,
earthquakes, or groundwater fluctuations may affect subsurface conditions and, thus, the continuing
adequacy of a geotechnical report.
GEOTECHNICAL ENGINEERING IS NOT AN EXACT SCIENCE
The site exploration and sampling process interprets subsurface conditions using drill action, soil sampling,
resistance to excavation, and other subjective observations at discrete points on the surface and in the
subsurface. The data is then interpreted by the engineer, who applies professional judgment to render
an opinion about over‐all subsurface conditions. Actual conditions in areas not sampled or observed may
differ from those predicted in your report. Retaining your consultant to advise you during the design
process, review plans and specifications, and then to observe subsurface construction operations can
minimize the risks associated with the uncertainties associated with such interpretations. The conclusions
described in your geotechnical report are preliminary because they must be based on the assumption that
conditions revealed through selective exploration and sampling are indicative of actual
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conditions throughout a site. A more complete view of subsurface conditions is often revealed during
earthwork; therefore, you should retain your consultant to observe earthwork to confirm conditions
and/or to provide revised recommendations if necessary. Allied Engineering cannot assume responsibility
or liability for the adequacy of the report’s recommendations if another party is retained to observe
construction.
EXPLORATIONS LOGS SHOULD NOT BE SEPARATED FROM THE REPORT
Final explorations logs developed by the consultant are based upon interpretation of field logs (assembled
by site personnel), field test results, and laboratory and/or office evaluation of field samples and data.
Only final exploration logs and data are customarily included in geotechnical reports. These final logs
should not be redrawn for inclusion in Architectural or other design drawings, because drafters may
commit errors or omissions in the transfer process.
To reduce the likelihood of exploration log misinterpretation, contractors should be given ready access to
the complete geotechnical report and should be advised of its limitations and purpose. While a contractor
may gain important knowledge from a report prepared for another party, the contractor should discuss
the report with Allied Engineering and perform the additional or alternative work believed necessary to
obtain the data specifically appropriate for construction cost estimating purposes.
OWNERSHIP OF RISK AND STANDARD OF CARE
Because geotechnical engineering is much less exact than other design disciplines, there is more risk
associated with geotechnical parameters than with most other design issues. Given the hidden and
variable character of natural soils and geologic hazards, this risk is impossible to eliminate with any
amount of study and exploration. Appropriate geotechnical exploration, analysis, and recommendations
can identify and reduce these risks. However, assuming an appropriate geotechnical evaluation, the
remaining risk of unknown soil conditions and other geo‐hazards typically belongs to the owner of a
project unless specifically transferred to another party such as a contractor, insurance company, or
engineer. The geotechnical engineer’s duty is to provide professional services in accordance with their
stated scope and consistent with the standard of practice at the present time and in the subject geographic
area. It is not to provide insurance against geo‐hazards or unanticipated soil conditions.
The conclusions and recommendations expressed in this report are opinions based our professional
judgment and the project parameters as relayed by the client. The conclusions and recommendations
assume that site conditions are not substantially different than those exposed by the explorations. If
during construction, subsurface conditions different from those encountered in the explorations are
observed or appear to be present, Allied Engineering should be advised at once such that we may review
those conditions and reconsider our recommendations where necessary.
RETENTION OF SOIL SAMPLES
Allied Engineering will typically retain soil samples for one month after issuing the geotechnical report. If
you would like to hold the samples for a longer period of time, you should make specific arrangements to
have the samples held longer or arrange to take charge of the samples yourself.