OTO-Wilson Rd Culvert Replacement - Preliminary Geotechnical Report (1).pdf
O:\J2900\2950 Fuss & O'Neill\30-01 Old Wilson Rd Northampton - Geotech\Report\OTO-Wilson RdCulvert Replacement - Geotech Recommendations.docx
J2950-30-01
November 30, 2023
Ms. Julianne Busa, P.E.
Fuss & O’Neill, Inc.
1550 Main Street, Suite 400
Springfield, Massachusetts, 01103
Re: Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
Dear Ms. Busa:
O’Reilly, Talbot & Okun Associates, Inc. (OTO) is pleased to provide these geotechnical
findings and recommendations for the culvert replacement project referenced above. The
subject culvert spans Nashawannuk Brook and is located on Old Wilson Road,
approximately 1,800 feet southwest of the intersection with Rocky Hill Road (Route 66) in
Northampton, Massachusetts. A Site Locus and Boring Location Sketch are attached.
Our geotechnical recommendations are based upon published information and
subsurface conditions observed in two borings. Our services consisted of a review of
published geologic information, the full-time observation of the borings, review of the logs
and soil samples, engineering analyses, and preparation of this report. This report is
subject to the limitations attached in Appendix A.
The recommendations in this report should be reviewed during final design and updated
as appropriate.
If you have any questions, please do not hesitate to contact the undersigned.
Sincerely yours,
O’Reilly, Talbot & Okun Associates, Inc.
Stephen McLaughlin, E.I.T Ashley Sullivan, P.E.
Senior Project Manager Principal
ii
TABLE OF CONTENTS
1.0 EXECUTIVE SUMMARY ........................................................................................... 1
1.1 Subsurface Conditions ........................................................................................... 1
1.2 Recommended Foundation System ....................................................................... 2
1.3 Construction Considerations .................................................................................. 2
2.0 INTRODUCTION ....................................................................................................... 3
2.1 Scope of Report ..................................................................................................... 3
2.2 Subject Background, Proposed Construction, and History ..................................... 3
2.3 Site Reconnaissance and Overall Description ........................................................ 3
3.0 SUBSURFACE CONDITIONS ................................................................................... 4
3.1 Local Geology ........................................................................................................ 4
3.2 Subsurface Exploration Program and Testing ........................................................ 4
3.3 Verification of Sample Descriptions on Boring Logs ............................................... 5
3.4 Subsurface Profile.................................................................................................. 5
3.5 Seismic Design Category Evaluation ..................................................................... 6
3.6 Liquefaction Potential ............................................................................................. 7
4.0 RECOMMENDED FOUNDATION SYSTEM .............................................................. 7
4.1 Existing Foundation ............................................................................................... 7
4.2 Embankment Considerations ................................................................................. 7
4.3 Deep Foundations.................................................................................................. 8
4.4 Spread Footing Foundations for Culverts and Wingwalls ....................................... 8
5.0 preliminary CONSTRUCTION CONSIDERATIONS ................................................ 10
5.1 Groundwater Considerations and Recommended Method for Water Control ....... 10
5.2 Engineered Fill Recommendations ...................................................................... 10
5.3 Excavations ......................................................................................................... 11
5.4 Obstructions......................................................................................................... 12
5.5 Protection of Adjacent Structures and Utilities ...................................................... 12
6.0 CONSTRUCTION CONSIDERATIONS ................................................................... 12
iii
TABLE OF CONTENTS (CONTINUED)
FIGURES
Figure 1 Site Locus
Figure 2 Boring Location Sketch
SHEETS
Sheet 1 General Compaction Guidelines
APPENDICES
Appendix A Limitations
Appendix B Boring Logs
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
1
1.0 EXECUTIVE SUMMARY
This report provides our preliminary geotechnical findings and recommendations for the
design of foundations for the proposed Old Wilson Road replacement culvert over
Nashawannuk Brook in Northampton, Massachusetts.
Summary of Existing and Proposed Replacement Structure
Type Size, Type Inlet Invert
(elevation)
Outlet Invert
(elevation)
Existing Structure
Concrete Pipe Approx. 2.3 foot
inner diameter N/A N/A
Proposed Replacement Structure
Embedded Concrete Box
Culvert or Open Bottom Culvert
(3 Sided Box)
Less than 10-foot
span N/A N/A
We understand that the existing pipe culvert will be completely removed, and a new culvert
will be constructed in its place. The type of structure has not been chosen, but it will likely
consist of either an embedded concrete box culvert or open bottom (3-sided) box culvert
with a clear span of less than 10 feet. Based upon the proposed type of structure, existing
data and estimated data, we anticipate that the new culvert will be founded on shallow
foundations bearing below a depth of five to six feet from the road surface, in the varved
sand and silt layer. To provide a firm bearing surface of the new culvert, we recommend
that footings bear on a minimum one-foot thick layer of imported Crushed Stone over the
varved sand and silt present at footing levels.
An organic layer, consisting primarily of a sandy silt mixed with organics, was encountered
in boring NB-2. The bottom of this organic layer was observed between 4 and 4.5 feet
below the ground surface. This depth is above the anticipated culvert bottom of footing
elevation; and therefore, this layer will be removed as part of footing construction. If this
material extends below anticipated culvert foundations and/or associated structures
(headwalls/wingwalls), it should be removed in its entirety. Resulting excavations may be
backfilled with Crushed Stone to proposed footing grade.
1.1 Subsurface Conditions
The two soil borings were performed off the shoulder of the road, approximately 17 to 22
feet from the existing culvert alignment. The borings were terminated at depths of 19.3 and
25.8 feet below the roadway surface. Soil boring NB-2 encountered refusal in the lower
granular layer. Boring locations are shown on the attached Boring Location Sketch. Boring
logs are attached.
Subsurface conditions at the Site generally consist of a surface layer of pavement and
granular base course or topsoil and underlain by (in order of increasing depth): reworked
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
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soils, varved sand and silt, and sand and gravel. A summary of conditions encountered in
the soil borings is provided as Table 1.
Table 1
Summary of Soil Boring Information
Boring
Ground
Surface
Elevation1 (ft)
Depth (ft) to:
Groundwater
Bottom of
Reworked
Soils
Maximum
Depth
Explored NB-1 N/A 5* 6 25.8
NB-2 N/A 4.5 4.5 19.3 (R)
Notes:
1. No ground surface elevations have been provided at this time. Data presented in this table are
based upon conditions encountered in the soil borings. Data shown in this table should be
considered accurate only to the degree implied by the methods used.
2. “R” indicates drilling refusal upon likely large cobble or boulder
* Borehole NB-1 was left open, and the water level was measured at 3.8 feet below ground surface
after 2.5 hours.
Groundwater was encountered initially at a depth of 5 to 4.5 feet below ground surface,
which was near the water level in Nashawannuk Brook at the time of drilling. The water
level in boring NB-1 was measured at 3.8 feet below ground surface after 2.5 hours. We
anticipate that groundwater levels will fluctuate with changes in the brook level.
The seismic Site Class was determined according to the AASHTO LRFD Culvert Design
Specifications, Article 3.10.3.1. Using the SPT N-value, the Site was determined to be Site
Class C. Based upon conditions encountered in the soil borings and the observed density
of saturated Site soils, it is unlikely that liquefaction would occur under the design
earthquake.
1.2 Recommended Foundation System
We recommend that the new culvert and associated structures (headwalls, wingwalls) be
supported on traditional spread footings bearing on at least one foot of Crushed Stone.
The minimum embedment depth of foundations should be 48 inches below surrounding
grade for frost, or below the maximum scour depth, whichever is greater.
Any organics (such as observed in boring NB-2) be removed from beneath the footings
and replaced with Crushed Stone. The Crushed Stone layer will provide a firm bearing
surface and protect the subgrade from disturbance during construction. A nonwoven
geosynthetic separation fabric should be installed beneath and around the Crushed Stone
layer. Foundation recommendations are presented in Tables 2 and 3. Soil conditions and
design parameters for use in the preliminary design of wingwalls or other retaining walls
are presented in Table 4.
1.3 Construction Considerations
The proposed culvert foundations will be installed below the base of Nashawannuk Brook
and below the maximum scour depth. Dewatering, cofferdams or temporary bypass
system may be required to install culvert elements, such as foundations and wingwalls.
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
3
2.0 INTRODUCTION
2.1 Scope of Report
This report provides preliminary geotechnical engineering recommendations for
foundation design of the proposed replacement culvert to carry Nashawannuk Brook
beneath Old Wilson Road in Northampton, Massachusetts. The location of the Site is
shown on Figure 1. This report also addresses earthwork considerations associated with
the proposed construction.
2.2 Subject Background, Proposed Construction, and History
2.2.1 Existing Conditions
The existing concrete pipe culvert carries Nashawannuk Brook, which flows from north to
south within the Site area, beneath Old Wilson Road. The existing culvert and brook
alignment are shown on the attached Boring Location Sketch. The existing culvert has a
diameter of 2.3 feet and length of approximately 22 feet. We understand the inlet and
outfall invert elevations of the existing culvert were not available at the time of this report.
The roadway surface in the subject area is approximately 3 to 4.5 feet above the water
surface at the time of drilling.
A buried water line is located along the centerline of the road. This utility appears to cross
the location of the existing pipe culvert.
2.2.2 Proposed Construction
We understand that the project includes the removal and replacement of the existing pipe
culvert. The structure type has not been selected; however, we understand that either a
box or 3-sided open box type structure with a span under 10 feet is currently being
considered. We understand the invert elevations for the replacement culvert have not
been determined. We understand that the foundation system and other elements of the
replacement culvert will be chosen based, in part, upon the conditions described and
recommendations provided in this report. We anticipate that the replacement culvert will
be founded upon traditional concrete spread footings bearing below the design scour
depth.
2.3 Site Reconnaissance and Overall Description
The Site is located on Old Wilson Road, approximately 1,800 feet to the southwest of the
intersection with Rocky Hill Road (Route 66) in Northampton, Massachusetts. An existing
conditions survey plan has not been completed for this location. Topography along the
roadway near the proposed culvert is generally flat. The roadway embankment slopes
downwards towards the south and north, towards Nashawannuk Brook. The existing
culvert at this location consists of a 2.3-foot inner diameter concrete pipe. Therefore, the
base of the existing culvert appears to be approximately 5 to 6 feet below the roadway
surface. The top of the existing culvert appeared to be approximately three feet below the
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
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pavement surface. The location of the existing culvert is shown on the attached Boring
Location Sketch.
3.0 SUBSURFACE CONDITIONS
3.1 Local Geology
We reviewed the surficial geologic map for the Easthampton Quadrangle1 to evaluate
likely geologic conditions at the Site. This map indicates Nashawannuk Brook flows
through flood plain alluvium underlain by fine grained post-glacial lake deposits at this
crossing. The glacial lake deposits include alternating layers of clay and sandy silt,
commonly known as varved silt and clay.
3.2 Subsurface Exploration Program and Testing
Subsurface investigations consisted of two soil borings performed on October 31, 2023,
by Seaboard Drilling of Chicopee, Massachusetts. The borings were performed using a
Mobile B-53 truck mounted drill rig and were advanced using hollow stem auger drilling
techniques.
Each boring was performed along the shoulder of Old Wilson Road (at the top of the
roadway embankment), approximately 18 to 23 feet from the existing pipe culvert
alignment. The boring locations were selected based upon rig access and proximity to
buried utilities. Boring NB-1 was extended to a depth of 25.8 feet below ground surface
and boring NB-2 encountered drilling refusal at a depth of 19 feet below ground surface.
Boring locations are shown on the attached Boring Location Sketch. Boring logs are
provided in Appendix B.
Soil samples were collected on a continuous or semi continuous basis from the ground
surface, until native soils were encountered, and at five-foot intervals thereafter. Soil
samples were collected using a two-inch diameter split spoon sampler, driven 24 inches
with a 140-pound automatic hammer falling 30 inches (American Society for Testing and
Materials Test Method D1586 “Standard Test Method for Penetration Test and Split-Barrel
Sampling of Soils”). The number of blows required to drive the sampler each six inches
was recorded. The standard penetration resistance, or N-value, is the number of blows
required to drive the sampler the middle 12 inches. Soil properties, such as strength and
density, are related to the N-value. The field N-values are corrected to a standard 60%
hammer efficiency, known as N60, to account for differing depth, sampler type, borehole
diameter, and hammer efficiencies for each hammer type and drill rig. The N-values
presented on the boring logs are field values, which are not adjusted for hammer
efficiency. However, the adjusted N60 values were used in our engineering calculations
and analysis.
An O’Reilly, Talbot & Okun Associates, Inc. (OTO) engineer observed and logged the
borings. Samples were classified according to a modified version of the Burmister Soil
1 Stone, Janet R. & DiGiacomo-Cohen, Mary (2018). “Surficial Materials Map of the Easthampton Quadrangle,
Massachusetts” US Geological Survey, Scientific Investigations Map 3402, Quadrangle 38 – Easthampton.
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
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Classification System. Borings performed in the roadway shoulder were backfilled with
soil cuttings.
3.3 Verification of Sample Descriptions on Boring Logs
I, Ashley Sullivan, a Massachusetts registered professional engineer, attest that I visually
and manually examined all soil samples as part of the preparation of this geotechnical
report. Samples collected from the subsurface investigations were reviewed at the
O’Reilly, Talbot, & Okun Associates, Inc. office, located in Springfield, Massachusetts on
November 29, 2023. The soil descriptions presented on the boring logs are consistent with
the soil samples collected during the Site explorations.
3.4 Subsurface Profile
Subsurface conditions were interpreted based upon information collected in the soil
borings and upon our review of published geologic maps. In general, subsurface
conditions at the boring locations consisted of the following, in order of increasing depth:
a surface layer of base course or topsoil; reworked soils; native fine-grained soils; and
sand and gravel. We note that the borings were performed at the top of the roadway
embankment, along the shoulder of the roadway. The ground surface elevation at each
boring location appeared to be approximately 5 to 6 feet above the level of the brook
channel bottom. This should be verified with survey.
Soil conditions are generally favorable for the proposed construction, and it appears that
the foundation for the new culvert will bear in the medium dense native soil layer present
below an approximate depth of six feet from the roadway surface. Since the new culvert
foundations will be below the brook level, the control of water will be a significant
construction consideration.
A summary of the conditions encountered in each of the soil borings is provided in Table 1.
3.4.1 Soil Conditions
Surficial Layers: The borings were performed in the roadway shoulder. At NB-1, a thin
sand and gravel layer (7 inches) was encountered at the ground surface. The top two
inches of the surficial layer contained a significant amount of roots. Eight inches of topsoil
was present at the ground surface in boring NB-2. The topsoil generally consisted of
medium sand, some silt, some medium to coarse sand, and organics (roots and tree
roots). Asphalt pavement was present within the roadway travel lanes.
Reworked Soils/Organic Soil: Reworked soils were encountered in each of the borings,
which appeared to have been placed during the construction of culvert and/or roadway
embankment. The soils generally consist of stiff to medium stiff, fine to medium sand and
silt or clayey silt with little coarse sand and trace fine gravel. The reworked soil layer
extended to a depth of 4 and 6 feet below the roadway surface. An organic soil layer
consisting of silt and fine to medium sand with trace organic sediment and an organic odor
was observed between a depth of 4 and 4.5 feet in NB-2. Trace amounts of organics
(roots) were also observed in boring NB-1 to a depth of 6 feet. The reworked soil and
organic layers are an unsuitable bearing material and should be completely removed from
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
6
beneath footings for new structures. We note that the depth of the organic layer may vary
based upon proximity to the current alignment of and historic meanders of Nashawannuk
Brook.
Varved Sand & Silt: A varved sand and silt layer was encountered beneath the surficial
reworked soils and organic soil and was observed to extend to an approximate depth of
10 feet below the roadway surface. This soil generally consisted of medium dense, varved
fine sand with some silt. The proposed culvert footings will likely bear within this layer.
Sand & Gravel: Granular soils were encountered below the varved sand and silt layer.
The upper portion of this layer consisted of approximately five to seven feet of loose to
medium dense sand with little silt and various amounts of gravel. The density and gravel
content increased with depth. The sand and gravel layer extended to the maximum depth
explored, 25 and 19 feet below ground surface in borings NB-1 and NB-2, respectively.
Boring NB-2 encountered auger refusal at 19 feet below ground surface, likely upon a
large cobble or boulder.
3.4.1 Bedrock Conditions
Rock was not encountered; however, we reviewed published geology maps. Bedrock
mapped as New Haven Arkose described on bedrock geology maps for the area2, which
is sedimentary rock of the upper Triassic epoch. We note that we do not anticipate that
bedrock will be encountered during construction of the new culvert.
3.4.2 Groundwater Conditions
Groundwater was encountered in borings NB-1 and NB-2 at a depth of 5 to 4.5 feet below
ground surface. Boring NB-1 was left open for a period of 2.5 hours and the water level
within the open borehole had risen to a depth of 3.8 feet. These groundwater elevations
were near the water level in the brook at the time of our explorations. We note that
groundwater will vary with changing water levels in Nashawannuk Brook.
3.5 Seismic Design Category Evaluation
Earthquake loadings must be considered under requirements of the 2023 MassDOT
Bridge Manual (MassDOT) and the most recent version of AASHTO LRFD Bridge Design
Specifications (AASHTO).
Section 3.4 of MassDOT covers seismic analysis and design. Lateral forces generated
during a seismic event are dependent on the type and properties of soils present beneath
the Site as well as geographic location. The USGS Seismic Design Maps web service was
used to determine seismic parameters for the Site. The peak ground acceleration (PGA),
as well as the maximum considered earthquake spectral response accelerations for short
periods (Ss) and for one-second (S1) were determined to be 0.058, 0.13, and 0.039,
respectively, for Northampton, Massachusetts. These values are for a non-critical/non-
2 Zen, E. et al. (1983). “Bedrock Geologic Map of Massachusetts” US Geological Survey.
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
7
essential bridge and based upon a seven percent probability of exceedance in 75 years
for a 1,000-year event.
Soil properties are represented through Site Classification. Procedures for the Site-
specific determination of Site Classification are provided in Article 3.10.3.1 of AASHTO.
At this Site, we evaluated Site Classification using Standard Penetration Resistance (SPT
N-value). Using the SPT N-value, the Site was determined to be Site Class C.
Furthermore, the Site coefficients Fpga, Fa, and Fv are determined using the PGA, Ss, and
S1 values and the Site Class. For Site Class C, Fpga, Fa, and Fv were determined to be 1.2,
1.2, and 1.7, respectively.
3.6 Liquefaction Potential
The potential for liquefaction of the saturated Site soils was evaluated. Based upon the
density of the soils, it is unlikely that liquefaction would occur under the design earthquake.
Seismic design and analysis of the proposed culvert should be performed in accordance
with the specifications provided in the 2023 MassDOT Bridge Manual and the most
recent AASHTO LRFD Bridge Design Specifications.
4.0 RECOMMENDED FOUNDATION SYSTEM
The following recommendations are provided for preliminary design of the culvert and
wingwall foundations. Foundations will be designed to resist lateral and vertical loads.
Vertical loads consist of downward pressures due to the dead weight of the culvert, the
weight of soils on the culvert roof, and live traffic loads, as well as uplift pressures due to
overturning loads (such as buoyant and seismic forces). All foundations should be
designed according to requirements provided in the 2021 MassDOT Bridge Manual
(MassDOT) and the most recent AASHTO LRFD Bridge Design Specifications
(AASHTO). We anticipate that the most appropriate foundation system will be spread
footings bearing on a one-foot-thick (minimum) layer of Crushed Stone, over the dense
native soils.
4.1 Existing Foundation
Construction drawings were not available at the time of this report.
4.2 Embankment Considerations
We anticipate that the proposed culvert will penetrate the existing roadway embankment
along Old Wilson Road. Therefore, the fills anticipated as part of this project will include:
• Placement of Crushed Stone beneath footings
• Backfill around and over the new culvert
• Replacement of soils disturbed during construction
• Backfill against wingwalls
• Placement of Processed Gravel for Subbase (M1.03.1) beneath final pavements
after the culvert is constructed
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
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Geotechnical concerns associated with the settlement or global stability of embankment
soils are not significant. Earthwork recommendations provided in Section 5.0 should be
followed.
4.3 Deep Foundations
At this time, we do not anticipate that deep foundations will be used to support the
proposed replacement culvert.
4.4 Spread Footing Foundations for Culverts and Wingwalls
The proposed culvert and associated wingwalls/headwalls may be founded upon shallow
spread footings bearing on a one-foot-thick (minimum) layer of Crushed Stone over native
Site soils. Tables 2 and 3 provides soil properties and preliminary design parameters for
use in design of spread footings. Spread footings should bear a minimum of four feet
below adjacent ground surface for frost protection; below the design scour depth; and
below organic soils layers, whichever is greater. For preliminary design, we anticipate that
footings for the new culvert and associated structures will bear in the varved sand and silt.
A review and update to the soil properties and design parameters provided in this report
should be performed during final design.
We recommend that a nonwoven geosynthetic separation fabric be placed beneath and
around the Crushed Stone layer beneath footings to prevent the migration of stone into
the underlying silty soils.
Table 2
Properties and Preliminary Design Parameters for Shallow Foundations
Bearing on 1-foot Crushed Stone over Dense Native Soils
Property/Design Parameter Recommended Value Angle of Internal Friction 34 Degrees
Soil Unit Weight 125 pcf
Interface Friction Angle1 17 degrees (Crushed Stone)
14 degrees (Native Silty Soils)
Friction Factor1 0.4 (Crushed Stone)
0.25 (Native Silty Soils)
Bearing Resistance Factor2, φb 0.45
Sliding Resistance Factor2,3, φτ 0.8
Passive Earth Pressure Component of Sliding Resistance2,3, φep 0.5
Notes:
1. Interface friction and friction factor for Crushed Stone and/or Native Silty Soils in contact with pre-cast concrete from
AASHTO Table 3.11.5.3-1.
2. Bearing and sliding resistance factors from AASHTO Table 10.5.5.2.2-1.
3. Sliding resistance factors for footings placed on Crushed Stone leveling pad.
4. See bearing capacity values in Table 3.
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
9
Table 3
Bearing Resistance for Varying Footing
Embedment Depth and Width
Footing
Embedment
Depth1
Bearing Resistance2
Strength Limit
State (ksf) Service Limit
State Nominal
(ksf)3 Nominal Factored
Footing Width (B) = 2 feet
4 10.3 4.6 3
2 6.3 2.8 3
0 2.3 1.0 3
Footing Width (B) = 4 feet
4 13.1 5.9 3
2 8.6 3.9 3
0 4.1 1.9 3
Notes:
1. Scour depth unknown at time of report writing; embedment
depth dependent on constructed footing geometry & design scour
depth
2. Bearing capacity values assumed firm bearing surface, i.e.
subgrade is over excavated by a minimum of 12 inches and 12
inches of crushed stone placed beneath footings
3. Bearing resistance for settlement of 1 inch.
Table 4
Soil Properties and Design Parameters for Headwalls, Wingwalls1
Soil Property/ M1.03.0 Type B Native Soils and Fill Design Parameter Gravel Borrow
Angle of Internal Friction 36 degrees 34 degrees
Equivalent Fluid Pressure (Active)3 35 pcf 40 pcf
Equivalent Fluid Pressure (At Rest)4 50 pcf 55 pcf
Notes:
1. Values presented in this table assume drained soil conditions.
2. Footings and retaining walls shall not bear on non-engineered fill.
3. Active Equivalent fluid pressure assumes that retaining walls will be unbraced and free to deflect
(cantilevered), level backfill from AASHTO Table 3.11.5.5-1. Values should be revised if sloping backfill.
4. At Rest Equivalent fluid pressure assumes that retaining walls will be braced, level backfill from AASHTO
Table 3.11.5.5-1. Values should be revised if sloping backfill.
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
10
4.4.1 Lateral Earth Pressures
Static lateral earth pressures will be imposed against the proposed culvert, wingwalls, and
any other earth retaining structures (such as earth support systems used during
construction). In addition, dynamic lateral earth pressures under the design earthquake
must be considered. These structures should be backfilled with MassDOT Gravel Borrow
(M1.03.0 Type B). A drainage system should be provided as required by MassDOT
specifications. Soil properties and design parameters for the determination of lateral
loading under drained conditions are provided in Table 4.
4.4.2 Scour Protection
A scour analysis was not available at the time of this report. The footings should extend
below the design scour depth, if applicable.
5.0 PRELIMINARY CONSTRUCTION CONSIDERATIONS
The following section presents preliminary construction considerations for the proposed
project. These recommendations should be reviewed during final design.
5.1 Groundwater Considerations and Recommended Method for Water Control
Groundwater was encountered at a depth of approximately 5 to 4.5 feet below ground
surface at the time of explorations. We note that the groundwater levels fluctuate in relation
to the water level of Nashawannuk Brook.
Groundwater will be present in excavations for foundations and the installation of the new
culvert, and stream flow will need to be diverted. During periods of relatively low water
levels, it should be possible to dewater small, short duration excavations extending only a
couple feet into the water table using sump pits and submersible pumps or well points.
However, for work during high water periods, the contractor will either need to stop work
or install a more robust system.
5.2 Engineered Fill Recommendations
Four types of engineered fill are recommended:
• Gravel Borrow (MassDOT designation M1.03.0, Type B) for use immediately
behind culvert walls and wingwalls
• Processed Gravel for Subbase (M1.03.1) for use immediately below pavements
• Special Borrow (M1.02.0) for use as miscellaneous fill
• Crushed Stone (M2.01.4) for use immediately below footings, in drainage
structures, and in place of Gravel Borrow
Grain size distribution requirements are presented in Table 5. The existing Site soils do
not likely meet requirements for reuse as engineered fill due to the high silt content of the
surficial soils.
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
11
Table 5
Grain Size Distribution Requirements
Fill Type/Use Gravel
Borrow
Processed Gravel
for Subbase
Special
Borrow
Crushed
Stone
MassDOT
Designation
M1.03.0,
Type B M1.03.1 M1.02.0 M2.01.4
Sieve Size Percent Finer by Weight
3 inch 100 100 100 (6” max) ---
2 inch --- --- 90 – 100 ---
1 ½ inch --- 70 – 100 --- ---
1 inch --- --- --- 100
¾ inch --- 50 – 85 --- 90 – 100
½ inch 50 – 85 --- --- 10 – 50
⅜ inch --- --- --- 0 – 20
No. 4 40 – 75 30 – 60 20 – 65 0 – 5
No. 50 8 – 28 --- --- ---
No. 200 0 – 10 0 – 10 0 – 12 ---
5.2.1 Compaction Recommendations
Compacted fill should be placed in lifts ranging in thickness between 6 and 12 inches
depending on the size and type of equipment. Recommended degrees of compaction and
compaction means and methods are presented on Sheet 1. Compaction within five feet of
the culvert or wingwalls should be performed using a hand-operated roller or vibratory
plate compactor weighing 250 pounds or less.
5.3 Excavations
The need for temporary earth support should be evaluated by the contractor. Sloping and
earth support may be needed if the excavation cannot be safely sloped to remove fill soils,
install utilities, and construct the new culvert and its associated foundations. The
contractor should evaluate the potential for basal heave when designing earth support and
dewatering systems and include provisions to prevent this condition from occurring.
5.3.1 Removal of Existing Culvert and Obstructions
The existing culvert will be removed as part of this project. If the new alignment differs
from the existing alignment, the excavation should be backfilled with Special Borrow
compacted to a minimum of 95% of the maximum dry density (as determined by ASTM
D1557). If the excavation extends below the groundwater table, it may be appropriate to
backfill portions of the excavation below the groundwater table with Crushed Stone.
Abandoned buried utilities containing asbestos (such as electrical conduit insulation or
transite pipe) are commonly found during construction excavations. Furthermore, former
structures (pipes, conduits, foundations walls) may contain or be covered with materials
containing asbestos. Such materials should be handled in accordance with MassDEP’s
asbestos regulations (310 CMR 7.15). We recommend that suspect materials be
Preliminary Geotechnical Engineering Recommendations
Old Wilson Road Culvert Replacement Project
Northampton, Massachusetts
November 30, 2023
12
managed appropriately and tested by a Department of Labor Standards (DLS) certified
asbestos inspector prior to disturbances.
5.3.2 Sloping and Earth Support
Soil may become unstable when excavations extend deeper than four feet or beneath the
groundwater table. The upper non-engineered fill and native silty sand encountered in the
upper 20 feet are estimated to be Type C soils for slope stability purposes. The maximum
allowable slope for excavations of Class C soils is 1.5H:1V (34°). All excavations should
conform to current OSHA requirements. These conditions apply only to excavations above
the groundwater table. We note that protective systems for any excavation exceeding
20 feet in depth must be designed by a registered professional engineer. All excavations
should conform to current OSHA requirements. The contractor should also follow
requirements in 29 CFR 1926.651(H)(3) for excavations that interrupt the natural drainage
of surface water.
In areas where sloping is not feasible, a temporary earth support system will be required
during construction. The design and engineering of the temporary earth support systems
should be the responsibility of the contractor. Prior to construction, we recommend that
the contractor evaluate the need for a temporary earth support system to protect the
existing roadway and personnel during construction.
5.4 Obstructions
Large boulders, cobbles, or other obstructions may be encountered in the non-engineered
fill. We recommend that provisions be made to remove obstructions, if encountered.
5.5 Protection of Adjacent Structures and Utilities
Nearby utilities include a water line and other utilities maybe present. The contractor
should evaluate the need for temporary support and/or geotechnical monitoring of existing
utilities.
6.0 CONSTRUCTION CONSIDERATIONS
This preliminary report should be reviewed and updated once a final survey is performed,
proposed culvert structure and alignment are finalized, and hydraulic and structural
studies are completed. Additional recommendations may be recommended if the
proposed structure and span, foundation depth and/or alignment differs from what is
presented in this report.
TABLES FIGURES
PROJECT No.
FIGURE No.
293 Bridge Street, Suite 500 Springfield, MA 01103 413.788.6222
O'Reilly, Talbot & Okun
E N G I N E E R I N G A S S O C I A T E S
www.OTO-ENV.com
OLD WILSON ROAD
CULVERT REPLACEMENT
OLD WILSON ROAD
NORTHAMPTON, MASSACHUSETTS
SITE LOCUSO:\J2900\2950 Fuss & O'Neill\30-01 Old Wilson Rd Northampton - Geotech\FiguresJ2930-30-01
1
Topographic Map Quadrant:
EASTHAMPTON, MA
Map Version: 1964
Current As Of: 1979
Date: OCTOBER 2023
1:25,000 SCALE NATIONAL GEODETIC VERTICAL DATUM 1929 10 FOOT CONTOUR INTERVAL
0 1000
FEET
0 0.5 1.0
MILES
0 0.5 1
KILOMETERS
SITE
FIGURE No.PROJECT No.293 Bridge Street, Suite 500 Springfield, MA 01103 413.788.6222
O'Reilly, Talbot & Okun
E N G I N E E R I N G A S S O C I A T E S
www.OTO-ENV.com
OLD WILSON ROAD CULVERT REPLACEMENT
OLD WILSON ROAD
NORTHAMPTON, MASSACHUSETTS
SITE SKETCHO:\J2900\2950 Fuss & O'Neill\30-01 Old Wilson Rd Northampton - Geotech\FiguresJ3017-01-012DESIGNED BY: CYI
DRAWN BY: CYI
CHECKED BY: SMM
DATE: 11/29/2023
REV. DATE:
SCALE IN FEET
1" = 50'
25'0'50'
LEGEND:
APPROXIMATE SOIL BORING LOCATION PERFORMED BYSEABOARD DRILLING ON 10/31/2023, OBSERVED BY OTO
NOTES:
1. BASE MAP INTERPRETED FROM MASS GIS2. SAMPLE LOCATIONS ARE SHOWN ACCORDING TO TAPED
MEASUREMENTS TAKEN FROM EXISTING SITE FEATURES
3. ALL DATA IS TO BE CONSIDERED ACCURATE ONLY TO THE DEGREE
IMPLIED BY THE METHODS USED IN THE DEVELOPMENT OF THIS PLAN
APPROXIMATE LOCATION OF
NASHAWANNUCK BROOKOLD WILSON ROADAPPROXIMATE PUBLIC
RIGHT OF WAY
APPROXIMATE LOCATION OF
EXISTING CULVERT,
2'-4" FEET INNER DIAMETER
CONCRETE PIPE
APPROXIMATE
ROADWAY SURFACE
NB-1
NB-2
TABLES SHEETS
PROJECT No.
SHEET No.
293 Bridge Street, Suite 500 Springfield, MA 01103 413.788.6222
O'Reilly, Talbot & Okun
E N G I N E E R I N G A S S O C I A T E S
www.OTO-ENV.com
Westfield Intermodal Transit Center
Elm and Arnold Streets
Westfield, Massachusetts
N
O’Reilly, Talbot & Okun
[ A S S O C I A T E S ]
ENGINEERING
SITE
C 2003 National Geographic Holdings, Inc.
Topographic Map Quadrant: West Springfield, MA Map Version: 1977
Current as of: 1979
Table 1-1
Degree of Compaction Recommendations
Location Minimum
Compaction
Below Structures (Foundations and Slabs) 95%
Below Pavements/Sidewalks/Exterior Slabs 95%
Against Basement Walls/Retaining Walls 92%
Utility Trenches 95%
General Landscaped Areas 90%
Notes.
1. Percentage of the maximum dry density as determined by Modified Proctor ASTM D1557, Method C.
2. When location falls into two or more categories, the engineer should be notified to determine appropriate
compaction efforts and/or methods.
3. Crushed stone should be compacted in lifts of 12 inches to form a dense matrix using either traditional
compaction methods (vibratory plate and/or roller) or tamping with an excavator bucket in deep
excavations. It is generally not necessary to perform laboratory or field density testing on crushed stone.
Table 1-2
General Guidelines for Compaction Means and Methods
Compaction Method
Maximum
Stone Size
(Inches
Diameter)
Maximum Lift
Thickness (Inches)
Minimum Number
of Passes
Below Structures
& Pavement
Non-
Critical
Areas
Below Structures
& Pavement
Non-
Critical
Areas
Hand-operated
Vibratory Plate
and confined spaces
3 6 8 6 4
Hand-operated vibratory
drum roller
(less than 1000 pounds)
3 6 8 6 4
Hand-operated vibratory
drum roller
(at least 1,000 pounds)
6 8 10 6 4
Light vibratory drum roller
(minimum 3000 pounds) 6 10 14 6 4
Heavy vibratory drum
roller (minimum 6000
pounds)
6 12 18 6 4
Note: The contractor should reduce or stop drum vibration if pumping of the subgrade is observed.
OLD WILSON ROAD
CULVERT REPLACEMENT
OLD WILSON ROAD
NORTHAMPTON, MASSACHUSETTS
GENERAL COMPACTION GUIDELINESO:\J2900\2950 Fuss & O'Neill\30-01 Old Wilson Rd Northampton - Geotech\FiguresDESIGNED BY: ALS
DRAWN BY: CYI
CHECKED BY:
DATE: 10/13/2023
REV. DATE:
J2930-30-01
1
TABLES APPENDIX ALIMITATIONS
LIMITATIONS
1. The observations presented in this report were made under the conditions described
herein. The conclusions presented in this report were based solely upon the services
described in the report and not on scientific tasks or procedures beyond the scope of
the project or the time and budgetary constraints imposed by the client. The work
described in this report was carried out in accordance with the Statement of Terms and
Conditions attached to our proposal.
2. The analysis and recommendations submitted in this report are based in part upon the
data obtained from widely spaced subsurface explorations. The nature and extent of
variations between these explorations may not become evident until construction. If
variations then appear evident, it may be necessary to reevaluate the
recommendations of this report.
3. The generalized soil profile described in the text is intended to convey trends in
subsurface conditions. The boundaries between strata are approximate and idealized
and have been developed by interpretations of widely spaced explorations and
samples; actual soil transitions are probably more erratic. For specific information, refer
to the boring logs.
4. In the event that any changes in the nature, design or location of the proposed
structures are planned, the conclusions and recommendations contained in this report
shall not be considered valid unless the changes are reviewed and conclusions of this
report modified or verified in writing by O'Reilly, Talbot & Okun Associates Inc. It is
recommended that we be retained to provide a general review of final plans and
specifications.
5. Our report was prepared for the exclusive benefit of our client. Reliance upon the
report and its conclusions is not made to third parties or future property owners.
TABLES APPENDIX BBORING LOGS
BLOWS/FOOT
(SPT N-Value)
0-4 Very soft
4-10 Soft
10-30 Medium Stiff
30-50 Stiff
>50 Very stiff
Hard
MATERIAL FRACTION SMALLEST
Coarse DIAMETER
Fine None SILT
Coarse 1/4" (pencil)clayey SILT
Medium 1/8"SILT & CLAY
Fine 1/16"CLAY & SILT
SILT/CLAY see adjacent table 1/32"Silty CLAY
COBBLES 1/64"CLAY
BOULDERS
TERM % OF TOTAL
and 35-50%
some 20-35%
little 10-20%
trace 1-10%
BORING LOGS
SUMMARY OF THE BURMISTER SOIL CLASSIFICATION SYSTEM (MODIFIED)
RELATIVE DENSITY (of non-plastic soils) OR CONSISTENCY (of plastic soils)
STANDARD PENETRATION TEST (SPT) COHESIONLESS SOILS COHESIVE SOILS
CONSISTENCY(SPT N-Value)
Very loose <2
Loose 2-4
*Based upon uncorrected field N-values >30
Method: Samples were collected in accordance
with ASTM D1586, using a 2" diameter split
spoon sampler driven 24 inches. If samples were
collected using direct push methodology
(Geoprobe), SPTs were not performed and
relative density/consistency were not reported.
N-Value: The number of blows with a 140 lb.
hammer required to drive the sampler the middle
12 inches.
WOR: Weight Of Rod (depth dependent)
WOH: Weight Of Hammer (140 lbs.)
RELATIVE
DENSITY
BLOWS/FOOT
Medium dense 4-8
Dense 8-15
Very dense 15-30
MATERIAL: (major constituent identified in CAPITAL letters)
COHESIONLESS SOILS COHESIVE SOILS
GRAIN SIZE RANGE PLASTICITY IDENTITY
GRAVEL 3/4" to 3"
1/4" to 3/4" Non-plastic
SAND
1/16" to 1/4" Slight
1/64" to 1/16" Low
Finest visible & distinguishable particles Medium
ADDITIONAL CONSTITUENTS COMMON TERMS
Cannot distinguish individual particles High
3" to 6" in diameter Very High
> 6" in diameter Wetted sample is rolled in hands to smallest possible
diameter before breaking.Note: Boulders and cobbles are observed in test pits and/or auger cuttings.
ORGANIC SILT: Typically gray to dark gray, often has strong H2S odor. May contain shells or shell fragments. Light weight.
Fibrous PEAT: Light weight, spongy, mostly visible organic matter, water squeezed readily from sample. Typically near top of layer.
Fine grained PEAT: Light weight, spongy, little visible organic matter, water squeezed from sample. Typically below fibrous peat.
DEBRIS: Detailed contents described in parentheses (wood, glass, ash, crushed brick, metal, etc.)
BEDROCK: Underlying rock beneath loose soil, can be weathered (easily crushed) or competent (difficult to crush).
RQD: Rock Quality Designation is determined by measuring total length of pieces of core 4" or greater and dividing by the total length of the
run, expressed as %. 100-90% excellent; 90-75% good; 75-50% fair; 50-25% poor; 25-0% very poor.
PID: Soil screened for volatile organic compounds (VOCs) using a photoionization detector (PID) referenced to benzene in air. Readings in
parts per million by volume.
Glacial till: Very dense/hard, heterogeneous mixture of sand, silt, clay, sub-angular gravel.
Deposited at base of glaciers, which covered all of New England.
Varved clay: Fine-grained, post-glacial lake sediments characterized by alternating layers
(or varves) of silt, sand and clay.
Fill: Material used to raise ground, can be engineered or non-engineered.
COMMON FIELD MEASUREMENTS
Torvane: Undrained shear strength is estimated using an E285 Pocket Torvane (TV). Values in tons/ft2.
Penetrometer: Unconfined compressive strength is estimated using a Pocket Penetrometer (PP). Values in tons/ft2.
Page 1 of 1
25.8
Doug
9 Nick
0 Hollow Stem Auger
A (1 5/8" O.D.)
FIRST (ft) 5.0 2" O.D. Split Spoon
LAST (ft) 3.8 Automatic
TIME (hr) 2.5 140 lb / 30"
DEPTH (ft)ELEV.
3/5/3/3 16/24 S-1 --GRAVEL 1,2
(0-2')0.75 -0.8
REWORKED SOILS
2/2/3/2 17/24 S-2 --
(2-4')
-5.0
5/6/7/7 14/24 S-3 --≡
(5-7')6.0 -6.0
VARVED SILTY
SAND
6/9/9/11 13/24 S-4 --
(7-9')
3/8/12/26 14/24 S-5 --
(10-12')11.0 -11.0
SAND AND GRAVEL
50 for 5"2/5 S-6 --3
(15-15.4')
15/19/43/50 19/24 S-7 --
(17-19')
30/39/39/37 17/24 S-8 --
(20-22')
35/50 for 4"12/10 S-9 --
(25-25.8')25.8 -25.8 4
1. Boring performed in shoulder alongside roadway.
2. Intermittent auger grinding at 3-4', 9-10', 11-15', 17-20', 20-25'.
3. Steady grinding from 15-16'.
4. Water level of brook on west side of roadway approximately 3'-10" from ground surface after 2.5 hours.
LOG OF BORING NB-1
PROJECT Old Wilson Rd Culvert Replacement CONTRACTOR Seaboard Environmental Drilling
START DATE 10/31/2023 DISTURBED SAMPLES HELPER CASE DIAMETER N/A
JOB NUMBER 2950-30-01 FINAL DEPTH (ft) DRILLING EQUIPMENT B-53 Truck Mounted Rig
LOCATION Northampton, MA SURFACE ELEV (ft) FOREMAN CASING
ENGINEER/SCIENTIST Caren Irgang WATER LEVEL ROD TYPE HAMMER DROP N/A
FINISH DATE 10/31/2023 UNDISTURBED SAMPLES BIT TYPE HAMMER WGT N/A
BORING
LOCATION North of existing culvert, west side of roadway
SAMPLER ROCK CORING INFORMATION
HAMMER TYPE TYPE N/A
HAMMER WGT/DROP SIZE N/A
DEPTH (ft)/
SAMPLES
SAMPLES
SAMPLE DESCRIPTION
(MODIFIED BURMISTER)
REMARKS/
WELL
CONSTRUCTION
PENETR.
RESIST.
(bl / 6 in)
REC.
(in)
TYPE/
NO.
FIELD
TEST
DATA
PROFILE
End of exploration at 25.8'
Very dense, gray, fine to medium SAND, some silt, little gravel, little coarse sand, trace
clay, wet
5'
10'
Top 6'': Stiff, gray, fine to medium SAND and clayey SILT, trace organics (tree root), wet
(silty pieces, some rust staining, tree root at bottom), trace fine gravel
Bottom 8'': Medium dense, gray, fine SAND and SILT, trace organics (tree root), wet (1/2"
fine sand varves)
Top 7'': Medium dense, gray to brown, varved fine SAND, some silt, wet (trace rust
staining in top 3",1/16" silt, 1/4" sand and silt varves)
Bottom 6'': Medium dense, gray to gray brown, varved fine SAND, some silt, wet
Medium dense, gray, fine SAND, some gravel, little coarse sand, little silt, wet
Poor recovery, gravel in spoon. From Cuttings: Gray, fine to medium SAND, some gravel,
little coarse sand, little silt, wet
Very dense, gray, fine to medium SAND and GRAVEL, little silt, wet
Very dense, gray, fine to medium SAND and GRAVEL, some coarse sand, little to some
silt, wet
Top 7'': very dark brown, fine GRAVEL, some fine to coarse sand, little silt, trace organics
(roots), damp (significant amount of roots in top 2")
Bottom 9'': Stiff, brown, fine to medium SAND and clayey SILT, little coarse sand, trace
fine gravel, damp (1" layer medium to coarse sand at 3" from top)
Medium stiff, brown, fine to medium SAND and clayey SILT, little coarse sand, trace fine
gravel, damp (2" layer medium to coarse sand with roots at 4" from top, bottom 8" moist)
LOG OF BORING
NB-1
Remarks:
25'
20'
PROJECT NO.
2950-30-01
15'
Page 1 of 1
19.3
Doug
7 Nick
0 Hollow Stem Auger
A (1 5/8" O.D.)
FIRST (ft) 4.5 2" O.D. Split Spoon
LAST (ft) N/A Automatic
TIME (hr) N/A 140 lb / 30"
DEPTH (ft)ELEV.
2/3/1/1 20/24 S-1 --TOPSOIL
(0-2') REWORKED SOILS
2/2/3/4 24/24 S-2 --
(2-4')
3.5 -3.5
ORGANICS
5/4/6/7 20/24 S-3 -- -4.5
(4-6') VARVED SILTY
SAND
9/8/9/8 20/24 S-4 --
(6-8')
10.0 -10.0
4/5/4/4 10/24 S-5 --SAND
(10-12')
1
4/4/9/12 21/24 S-6 --
(15-17')
17.0 -17.0
SAND AND GRAVEL
2
50 for 3"2/3 S-7 -- 19.0 -19.0 3,4
(19-19.3')
1. Auger grinding at 14'.
2. Steady grinding from18.5-19'.
3. Auger refusal at 19'. Applied 500 pounds of down pressure.
4. Water level of brook on west side of roadway at approximately 4'-6" from ground surface.
LOG OF BORING NB-2
PROJECT Old Wilson Rd Culvert Replacement CONTRACTOR Seaboard Environmental Drilling
START DATE 10/31/2023 DISTURBED SAMPLES HELPER CASE DIAMETER N/A
JOB NUMBER 2950-30-01 FINAL DEPTH (ft) DRILLING EQUIPMENT B-53 Truck Mounted Rig
LOCATION Northampton, MA SURFACE ELEV (ft) FOREMAN CASING
ENGINEER/SCIENTIST Caren Irgang WATER LEVEL ROD TYPE HAMMER DROP N/A
FINISH DATE 10/31/2023 UNDISTURBED SAMPLES BIT TYPE HAMMER WGT N/A
BORING
LOCATION South of existing culvert, east side of roadway
SAMPLER ROCK CORING INFORMATION
HAMMER TYPE TYPE N/A
HAMMER WGT/DROP SIZE N/A
DEPTH (ft)/
SAMPLES
SAMPLES
SAMPLE DESCRIPTION
(MODIFIED BURMISTER)
REMARKS/
WELL
CONSTRUCTION
PENETR.
RESIST.
(bl / 6 in)
REC.
(in)
TYPE/
NO.
FIELD
TEST
DATA
PROFILE
10'
5'
Top 3'': Medium dense, gray to brown to black, SILT and fine to medium SAND, moist
(organic odor)
Bottom 17'': Medium dense, gray to brown, varved fine SAND, some silt, little medium
sand, trace coarse sand, wet (2" layer silt some fine sand in middle and 5" from bottom)
Top 7'': Medium dense, brown gray, fine SAND, some silt, wet (1" layer some silt at 5" from
top)
Next 10'': Medium dense, brown gray, varved fine SAND, little silt, wet (1/16-1/8" fine sand
varves)
Bottom 3'': Medium dense, brown gray, varved fine SAND, some silt, wet (1/8-1/2" fine
sand varves)
Top 8'': Loose, very dark brown, medium SAND, some silt, some fine to coarse sand, trace
fine gravel, trace organics (roots, tree roots), damp (TOPSOIL)
Bottom 12'': Loose, dark brown, fine to medium SAND and SILT, some coarse sand, trace
fine gravel, moist (trace rust staining at 8" from bottom)
Top 16'': Loose, brown, fine to medium SAND and SILT, little coarse sand, wet (trace rust
staining)
Bottom 8'': Medium stiff, gray to brown, clayey SILT, some fine sand, little medium sand,
trace coarse sand, trace organics (roots), damp (trace rust staining)
15'
Loose, gray, fine to medium SAND, little silt, little coarse sand, trace gravel, trace (-) clay,
wet (some silt in top 4")
Dense, gray, GRAVEL and fine to medium SAND, little silt, little coarse sand, wet
20'Auger refusal at 19', likely upon boulder
Medium dense, gray, fine to medium SAND, little silt, little coarse sand, trace gravel, wet
(1/2-2" layer fine sand trace silt at 3" and 5" from bottom, gravel piece at bottom)
25'
Remarks:PROJECT NO.
2950-30-01
LOG OF BORING
NB-2