HomeMy WebLinkAbout00-3132-Geotechnical-Data_Rev_1Dennis Yarmouth Intermediate Middle School January 19, 2021
Dennis Yarmouth Regional School District 100% Construction Documents
Perkins Eastman DPC, project #71011
GEOTECHNICAL DATA
00 3132 - 1
DOCUMENT 00 3132
GEOTECHNICAL DATA
1.1 GEOTECHNICAL DATA
A. This Document with its referenced attachments is part of the Procurement and Contracting
Requirements for Project. They provide Owner's information for Bidders' convenience and are
intended to supplement rather than serve in lieu of Bidders' own investigations. They are made
available for Bidders' convenience and information. This Document and its attachments are not
part of the Contract Documents.
B. Because subsurface conditions indicated by the soil borings are a sampling in relation to the
entire construction area, and for other reasons, the Owner, the Architect, the Architect's
consultants, and the firm reporting the subsurface conditions do not warranty the conditions
below the depths of the borings or that the strata logged from the borings are necessarily typical
of the entire site. Any party using the information described in the soil borings and geotechnical
report shall accept full responsibility for its use.
1. Bidders are urged to examine the geotechnical data and to make their own investigation
of the site before bidding.
C. Two geotechnical investigation reports for Project, titled “Feasibility Phase Geotechnical Data
Summary Report” (23 pages) and “Design Phase Geotechnical Report” (36 pages), prepared by
Geotechnical Partnership, Inc., is available for viewing as appended to this Document.
1. The opinions expressed in this report are those of a geotechnical engineer and represent
interpretations of subsoil conditions, tests, and results of analyses conducted by a
geotechnical engineer. Owner is not responsible for interpretations or conclusions drawn
from the data.
2. Any party using information described in the geotechnical report shall make additional
test borings and conduct other exploratory operations that may be required to determine
the character of subsurface materials that may be encountered.
D. Related Requirements:
1. Document 00 2113 "Instructions to Bidders" for the Bidder's responsibilities for
examination of Project site and existing conditions.
2. Document 00 3119 "Existing Condition Information" for information about existing
conditions that is made available to bidders.
3. Document 003126 "Existing Hazardous Material Information" for hazardous materials
reports that are made available to bidders.
END OF DOCUMENT
(THIS PAGE IS BLANK)
Geotechnical Partnership, Inc.
Geotechnical Engineering Services for New England
Since 1987 Lisa R. Casselli,PE Principal - A WBE Firm
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Subsurface Exploration Laboratory Soil Testing Geothermal Testing
Foundation Specialty Systems Ground Improvement Earthwork Testing
45 New Ocean Street – Suite A 805 Main Street
Swampscott, MA 01907 Sanford, ME 04073
Tel. 781/646-6982 Tel. 207/459-7800
4 April 2018
File No. 1814
PEADPC No. 71010.00.0
Perkins Eastman Architects DPC
20 Ashburton Place, Floor 8
Boston, MA 02108
Attention: Daniel Colli – Associate Principal
Subject: Feasibility Phase Geotechnical Data Summary Report
Proposed Dennis-Yarmouth Intermediate School
296 Station Avenue
South Yarmouth, Massachusetts
Dear Dan:
This geotechnical data
summary report outlines our
site background data review,
initial subsurface explorations,
preliminary field soil and
groundwater testing,
engineering data summary,
analyses and calculations in
support of the feasibility phase
review of the proposed new
intermediate school building to
be erected in South Yarmouth,
Massachusetts (Figure 1)
Our feasibility phase
geotechnical engineering data
summary, analyses and
recommendations follow.
Proposed Dennis-Yarmouth Intermediate School 2 4 April 2018
South Yarmouth, MA GPI File No. 1814
I. Proposed Construction:
Existing Conditions:
Plan reference:
o Feasibility Study – Dennis Yarmouth Intermediate School – Existing Conditions Exhibit
(C-1) prepared by Doucet & Associates of Easthampton, Massachusetts; dated 26 March
2018; 100-scale.
o Feasibility Study – Dennis Yarmouth Intermediate School – Existing Conditions Exhibit
(C-1B; aerial base plan) prepared by Doucet & Associates of Easthampton,
Massachusetts; dated 26 March 2018; 100-scale. Some contour interval elevations were
added on 5 April 2018.
o No existing site utility plan was available to us at the time of this review.
Direction, Datum, Elevation and Coordinates:
o Direction:
Plan north: Figure 1A
Called north for this review: in the general direction of Christmas Way
o Datum and Elevation:
Vertical elevation datum: Town GIS referenced on drawing C-1B.
Site elevations:
Elevation trend between boring locations was taken from drawing C-1B
numbered contour intervals.
Site area elevation change patterns can be seen in gross scale in Figure 1: 3D
USGS Area Topographic Plan was undertaken.
o Site Coordinates:
Latitude: 41.6803° N
Longitude: -70.1974° W
Proposed Dennis-Yarmouth Intermediate School 3 4 April 2018
South Yarmouth, MA GPI File No. 1814
Existing Site Conditions:
o No attempt has been made to
undertake a history of this site.
Historic review is included in
research for Phase I
environmental site assessments.
o A 1905 historic property map
(Figure 1B) showed the site area
to be generally undeveloped.
o The proposed intermediate
school building site (Figure 1A,
Figure 1C) is currently woodland
west adjacent to the Station
Avenue Elementary School.
o Existing general project site
elevation range: El. 26 ft. to
El. 32 ft. (from C-1B).
o The immediate building site area
ground surface is relatively level
with included shallow mounds.
o No bedrock outcrops are visible
on-site or in adjacent areas. .
o Active underground site structures and utilities:
Likely non-existent on this undeveloped site.
The reviewed potential site utilities’ list is held by the test boring contractor.
Anticipated New Construction:
Plan Reference:
o Feasibility Study – Dennis Yarmouth Intermediate School – Landscape Site Plan (L-101)
prepared by Traverse Landscape Architects of Providence, Rhode Island; dated
26 March 2018; 100-scale.
o Feasibility Study – Dennis Yarmouth Intermediate School – First Floor Plan(s) (A-101)
prepared by Perkins Eastman Architects of Boston, Massachusetts; dated 26 March
2018; 1/32-scale.
o Feasibility Study – Dennis Yarmouth Intermediate School – First Floor Plan(s) (A-101)
prepared by Perkins Eastman Architects of Boston, Massachusetts; dated 26 March
2018; 1/32-scale.
o Feasibility Study – Dennis Yarmouth Intermediate School – Second Floor Plan(s) (A-102)
prepared by Perkins Eastman Architects of Boston, Massachusetts; dated 26 March
2018; 1/32-scale.
o Feasibility Study – Dennis Yarmouth Intermediate School – Massing(s) (A-201) prepared
by Perkins Eastman Architects of Boston, Massachusetts; dated 26 March 2018;
1/32-scale.
o Feasibility Study – Dennis Yarmouth Intermediate School – Typical Wall Section (A3101)
prepared by Perkins Eastman Architects of Boston, Massachusetts; dated 26 March
2018; 1/2-scale.
Building Structural Information: as presently understood
o Building levels: (Figure 1C)
Three (3) above-grade levels
No below-grade levels
Elevators and stairways:
Elevators: two
Stairways: four
Proposed Dennis-Yarmouth Intermediate School 4 4 April 2018
South Yarmouth, MA GPI File No. 1814
o Foundation footings:
Interior column footings (assumed):
400 K applied total load (assumed)
Bottom of footing (BOF; Figure 4):
o Interior footings: 2 feet below top of lowest level floor slab (assumed)
o Exterior walls and columns (pilasters): assumed at recommended frost depth
Exterior wall footing: 10 KLF applied total load (assumed)
o Lowest level floor level (Figure 4):
Assumed uniform
1st floor finish floor elevation (FFE): El. 28.5 ft. (assumed)
o Elevator pits: elevator pits’ base elevations are typically at 4 ft. below lowest level slab
finish floor (El. 24.5 ft.; assumed).
Proposed Dennis-Yarmouth Intermediate School 5 4 April 2018
South Yarmouth, MA GPI File No. 1814
II. Subsurface Conditions:
Topographic Data:
Elevation Range: The general site area is relatively level to slightly to moderately sloping
(Figure 1: 3D USGS Area Topographic Plan).
Area Surficial Geology:
o Area surficial geology is the result of a complex interaction of glacial advance and retreat
and intrusive marine action.
o The project area lies within a relatively level glacial fluvial (outwash) plain bounded north
by glacial moraine formations left behind by glacial scour and melt, and east by post-
glacial wetlands.
Figure 1 shows the site lies within a relatively level ground area (glacial lowlands or
outwash areas) created by soil deposition from glacial ice meltwater.
Glacial moraines are an accumulation of glacial drift (silt, sand and gravel) within a
glaciated region by deposition and thrust of glacial ice (bulldozed material)
o The vertical scale in Figure 1 has been purposely exaggerated by a factor of 4X to better
reveal subtle topographic variation.
o According to area surficial geologic mapping utilizing the site latitude and longitude
coordinates [Massachusetts GIS, Surficial Geology; Commonwealth of Massachusetts
Office of Geographic Information; September 2012] the site was predicted to be located
upon the following native materials:
Glacial fluvial soil (Figure 1, Figure 1D); over
Glacial till and/or bedrock.
Proposed Dennis-Yarmouth Intermediate School 6 4 April 2018
South Yarmouth, MA GPI File No. 1814
Area Water Bodies:
o Flax Pond: 2870 ft. east
o Long Pond: 3500 ft. south
o Plashes Pond: 6000 ft. west
o Other pond: 790 ft. north
o No other significant project area water bodies (ponds, lakes, rivers, streams) are mapped
on Figure 1.
o Mapped wetlands are found in lowlands as shown on Figure 1:
2400 ft. east and 2600 ft. southeast.
They may also may exist on the wooded section of campus as localized woodland
wetlands.
Anticipated Site Substrata: based upon the collected geologic and topographic data,
anticipated native site subsoils were considered as follows:
o Organic deposits (peat)
o Glacial fluvial material (silt, sand and gravel).
o Glacial till (basal till; hardpan)
Area Bedrock Geology: [US Department of the
Interior; US Geological Survey, Massachusetts State
Geologic Map; 1998; see Figure 1E]
o Common area bedrock: alkali feldspar granite
A crystalline igneous rock.
Granitic rock with dominant alkali feldspar
content and lesser quartz
A hard, sound medium grained rock
o Other common area bedrock: amphibolite schist
Accompanies granitic gneiss (secondary);
A class of metamorphic rock with one of the
amphibole minerals (silica rock making
minerals) as the dominant constituent:
bright green to dark-green to black
crystalline rock consisting chiefly of
amphibole and plagioclase feldspar; can
also be gray or whitish
Chief minerals include plagioclase feldspar
and amphibole with minor garnet and quartz.
Crystalline metamorphic rock with closely
spaced foliations; foliation surface is rough
Tends to readily split into thin flakes or slabs
More evident visible crystallization than
slates
With increase of feldspar and quartz and
decrease of schist forming minerals pass into more irregular foliated gneiss
o Other common area bedrock: granitic gneiss
Banded metamorphic rock; bands typically 1 mm to 1 cm thick); defined by texture
and arrangement of mineral grains
Layers are mineralogically unlike; coarse grained
Can originate from igneous rock (granite): recrystallization due to intense regional
metamorphism
Dominated by quartz and feldspar
Gray, well layered biotite-plagioclase-quartz gneiss
Proposed Dennis-Yarmouth Intermediate School 7 4 April 2018
South Yarmouth, MA GPI File No. 1814
o Depth to bedrock:
No specific depth data was available from the MA GIS (2012 database).
Area experience indicates bedrock is found at the base of thick glacial fluvial and thin
glacial till deposits.
Previous Test Borings
On-Site Borings:
o None of record were found on the subject site.
o No remnant groundwater wells were found which would have indicated prior subsurface
site review.
Test Borings Undertaken for this Study
Dig Safe:
o General Dig Safe site underground utility clearance: was provided by Soil Exploration
Corp. of Leominster, MA.
The Dig Safe ticket number is held by the drilling contractor.
Utilities contacted: utilities’ list is held by Soil Exploration
o Test boring locations were laid out on-site by Soil Exploration.
Test borings:
o Drilling by Soil Exploration Corp: four (4) structural test boring (designated B1 through
B4) were drilled on-site during 4 April 2018.
o Refer to Figure 2: Site Exploration Location Plan for approximate as-drilled test boring
locations based upon the current building configuration and boring locations provided by
Perkins Eastman DPC.
Proposed Dennis-Yarmouth Intermediate School 8 4 April 2018
South Yarmouth, MA GPI File No. 1814
o An ATV mounted drill-rig equipped with an auto-hammer (Photo 1), drilled and sampled
soils in the borings below grade.
Soil samples were taken in 2-foot increments.
Auger borings were drilled to 22 ft. depth below existing grade with:
Semi-continuous sampling and testing to 9 ft. depth and
Standard 5 ft. interval sampling and testing thereafter.
Digital Boring Logs:
o Recovered test boring soil samples were digitally logged by the geotechnical engineer in
accordance with ASTM D-5434-97: Standard Guide for Logging of Subsurface
Explorations of Soil and Rock.
o Boring logs prepared by the engineer are presented in soil boring log sheets in
Appendix A. Logs detail soil type, boundary elevation or depth, density, consistency,
thickness, coloration, moisture and composition.
Photo 2: Auger Drilling Boring B4 with ATV Mounted Drill Rig
III. Geotechnical Testing:
Field Testing Performed:
Standard Penetration Tests (SPT)
(N70 in blows/foot)
Field Gradation Tests
Standard Penetration Testing (SPT):
SPT Presentation and Definition:
o A standard penetration test is defined
as the number of blows of a 140 lb.
hammer falling 30 inches to drive a
standard soil split spoon sampler 12
vertical inches. The number of blows
is designated as “N”
o Standard penetration tests (SPT) N are summarized for the borings with elevation on the
boring logs in Appendix A and in Figure 4.
o Field SPT N (blows/foot) is taken from blow count graphs provided on the boring logs.
o Standard penetration test N is plotted for the borings with elevation in Figure 3.
SPT Type:
o The borings drilled for this study (see Appendix A) used an auto-hammer sampler drive
system which delivers replicable, consistent energy for each blow.
o This is considered an improvement over older style drill rigs which utilized a rope and
cathead (donut) system and can have operator error or bias particularly when drilling in
dense soils (e.g. “short stroke” as driller tired, yielding artificially high N values).
SPT N Data Analysis of this Site:
o Note that in the plots of N with depth in Figure 3:
Boring N values are low within the glacial fluvial sand to as deep as El. 17 ft.+/-
Boring N values increase somewhat with depth to a low medium dense condition
within the glacial fluvial sand material.
N values within the low medium dense glacial fluvial sand can be seen to vary slightly
and oscillate with depth below El. 17 ft.+/-
o See also the N pattern variation with depth in Figure 4 as well as in the blow count
graphs on individual boring logs in Appendix A.
Proposed Dennis-Yarmouth Intermediate School 9 4 April 2018
South Yarmouth, MA GPI File No. 1814
SPT N Engineering Uses: SPT data can be useful in determination of values of soil bearing
capacity, Young’s Modulus for footing settlement evaluation, as well as input to footing base
soil friction angle, seismic site class and slab subgrade modulus determination.
Corrected SPT N:
o Correction of raw field N70 values is performed based upon factors of soil overburden
pressure, drill rig sampler hammer type, drill rod length, sampler liner, etc. These are
employed to calibrate the field N values reported.
o Auto hammer field N values can require initial correction by a factor of about 1.15 when
using other hammer systems as a basis for calculations.
o Final N energy adjustment to N55 is required for performance of granular soil foundation
settlement calculations [refer to Joseph E. Bowles; Foundation Analysis and Design;
5th Edition; 1997].
Field Gradation Tests:
Test Use: Limited field gradation tests were performed to better determine the relative
percents of coarse gravel, fine gravel, coarse sand, and medium sand and fines (silt and fine
sand) in recovered glacial fluvial soil samples.
Limitations:
o Field tests are limited to recovered dry or field air dried soil samples.
o 4-sieve method does not allow separation of silt from fine sand.
Laboratory Soil Testing:
Testing Performed: no soil particle gradation or other soil testing was performed for the soil
materials encountered on-site.
Proposed Dennis-Yarmouth Intermediate School 10 4 April 2018
South Yarmouth, MA GPI File No. 1814
IV. Soil Strata:
Data Summaries:
Profile Data Summary: General summaries of soil substrata found in the subsurface
explorations are provided in Table I
Subsurface Summary Drawings:
o Refer to the subsoil profile sketched in Figure 4 to gain an initial overview of site
subsurface soil conditions within the proposed building area (Figure 1C, Figure 2).
o Subsoil profile orientation within the building area are given on the profile drawing.
Profile Field Descriptions: Detailed field soil descriptions are given in the boring logs
(Appendix A).
Table I: Exploration Summary
Test
Boring
No.
Ground
Surface
El. (ft.)
[datum?]
Depth
Drilled
(ft.)
Topsoil,
(ft.)
Loose
Glacial
Fluvial
(ft.)
Medium
Dense
Glacial
Fluvial
(ft.)
Glacial
Till
(ft.)
B1 26+/- 22.0 1.2 8.3 >12.5
B2 28+/- 22.0 1.0 5.0 >16
B3 28+/- 22.0 1.1 4.9 >16
B4 30+/- 22.0 1.2 3.8 >21
Proposed Dennis-Yarmouth Intermediate School 11 4 April 2018
South Yarmouth, MA GPI File No. 1814
Proposed Dennis-Yarmouth Intermediate School 12 4 April 2018
South Yarmouth, MA GPI File No. 1814
Soil Classification System Used for this Site Investigation:
Soil Classification System: Project soils have been classified in accordance with the Unified
Soil Classification System (USCS; MIT System). This is reflected in the test boring logs in
Appendix A.
Soil Descriptions: Soils are described in terms of color, grain size, moisture content, density
(coarse grained soils), consistency (fine grained soils), plasticity and cementation, as
appropriate.
Grain Size Boundaries (dia.) Common Size Example
Boulder >12 in. >Basketball
Cobble 3-in. to 12-in. Grapefruit size
Coarse Gravel ¾-in. to 3-in. Lemon size
Fine Gravel #4 Sieve (4.75mm) to ¾-in. Pea to grape size
Coarse Sand #10 Sieve (2 mm) to #4 Sieve Peppercorn size
Medium Sand # 40 Sieve (.425 mm) to #10 Sieve Sugar to table salt size
Fine Sand #200 Sieve (.075 mm) to #40 Sieve Powdered sugar size
Silt/Clay <#200 Sieve (.075 mm) Flour particle or finer
Soil Moisture Content:
o Dry: no moisture noted
o Moist: some moisture observed
o Very moist: very moist, but not saturated (possible vadose zone)
o Wet: saturated above the liquid limit (likely groundwater zone)
Soil Density and Consistency:
o Density of coarse grained soils (non-plastic silts, sands, gravels): defined in terms of
standard penetration test blowcount N values (refer to the summary table at the bottom of
any boring log)
o Consistency (plastic silts, clay, and organics): defined secondarily in terms of blowcount
N values and primarily with respect to field unconfined compressive strength in TSF (refer
to the summary table at the bottom of any boring log).
Soil Particle Percentage Field Designation: Relative soil particle size percentages (trace,
few, little, some, mostly [capitalized soil unit]): refer to summary table at bottom of any boring
log. These are more accurately tallied by laboratory soil particle gradation tests.
Subsoil Classes on this Site: USCS soil type designations utilized in this report:
o AR = man placed fill; artificial soil stratum
o SP = glacial fluvial sand
o GT = glacial till
o WR = weathered rock
o GT = granitic rock
Proposed Dennis-Yarmouth Intermediate School 13 4 April 2018
South Yarmouth, MA GPI File No. 1814
Photo 2: Near Surface Glacial Fluvial Sand Photo 3: Likely Glacial Fluvial Bearing Soi
Photo 4: Medium Dense Glacial Fluvial Sub-Layer Photo 5: Fine Grained Glacial Fluvial Sub-Layer
Site Subsoil Descriptions:
Existing Fill (AR): no fill material was found at the boring locations drilled
Organics (OH, PT): no organic soils were encountered in the borings drilled
Glacial Fluvial (Glacial Outwash; SP):
o Definition and Source:
Refer to the “Area Surficial Geology” report section (page 5).
Glacial fluvial plains are shown on Figure 1A.
o Description: (Photo 2, Photo 3, Photo 4, Photo 5)
USCS: SP: uniform (poorly graded) fine sand (Photo 5) or medium to fine sand
(Photo 2, Photo 3, Photo 4) with limited gravel and silt content
Proposed Dennis-Yarmouth Intermediate School 14 4 April 2018
South Yarmouth, MA GPI File No. 1814
Cohesionless.
Coloration: varied from orange-brown to tan-yellow to tan at the drilled locations
Found below the surficial topsoil at the locations and depths drilled (Table I, Figure 4,
Appendix A).
These soils are water bearing (Figure 4, Appendix A).
o Competency:
Generally very loose to loose in the upper portion
Low medium dense soil density in-situ at depth (Figure 3, Figure 4, Appendix A).
These soils will be exposed in site excavations (Figure 4).
Glacial Till: till was not encountered to the maximum depth drilled (22 ft.) on-site.
Bedrock:
o Occurrence:
No rock outcropping was noted either on-site or on nearby properties.
Depth to bedrock: bedrock was not found to the 22 ft. depth drilled on-site.
o Rock types: refer to “Area Bedrock Geology” report section (pages 6-7) and Figure 1E.
Photo 6: Soil rust lines Photo 7: Soil rust stains with lines
Photo 8: Saturated (water bearing) glacial fluvial soil
V. Groundwater Behavior
Free Water:
o Wet (saturated) soil was encountered In
the glacial fluvial sand layer in all site
borings (Photo 8).
o Site groundwater is unconfined.
o The site lies within a mapped significant
groundwater aquifer (refer to Figure 5:
Area Groundwater Aquifers).
o No groundwater monitoring wells were
found on-site. No wells were installed in
the borings during this phase of review.
o Table II and Table IIA summarize the site
groundwater data collected.
Proposed Dennis-Yarmouth Intermediate School 15 4 April 2018
South Yarmouth, MA GPI File No. 1814
Table II: Groundwater Monitoring Well Observations
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Loc. No. Elevation Date Observation Groundwater Depth Groundwater El.
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B1 26 ft.+/- 04/04/18 Wet Soil 7.0 ft. 19.0 ft.+/-
B2 28 ft.+/- 04/04/18 Wet Soil 7.5 ft. 20.5 ft.+/-
B3 28 ft.+/- 04/04/18 Wet Soil 7.0 ft. 21.0 ft.+/-
B4 30 ft.+/- 04/04/18 Wet Soil 11.0 ft. 19.0 ft.+/-
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Table IIA: Indications of Seasonal High Groundwater Elevation
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Loc. No. Elevation Date Observation Groundwater Depth Groundwater El.
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B1 26 ft.+/- 04/04/18 Rust Stains 5.0 ft. 21.0 ft.+/-
B2 28 ft.+/- 04/04/18 Rust Lines 5.0 ft. 23.0 ft.+/-
B3 28 ft.+/- 04/04/18 Rust Lines 5.5 ft. 22.5 ft.+/-
B4 30 ft.+/- 04/04/18 Rust Stains 5.0 ft. 25.0 ft.+/-
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Groundwater Level Variation:
o Clear soil rust staining and/or rust lines were seen in all site soil borings.
Rust staining and mottling can give an indication of water level at or approaching
seasonal high groundwater level.
Soil rust lines and rust staining are summarized in Table IIA and noted on the boring
logs in Appendix A.
o Groundwater was found in glacial fluvial sand in all borings drilled (Table II; see also the
“Free Water” report sub-section and Figure 4).
Proposed Dennis-Yarmouth Intermediate School 16 4 April 2018
South Yarmouth, MA GPI File No. 1814
o Localized temporary and long term changes to groundwater level can be natural or man-
made. These changes source from activities such as:
The 2016 extreme drought condition and the relatively dry summer of 2017, although
ended may still have lingering influence. This is borne out by some area mapping.
Winter drier season water levels.
Heavy rainstorms or lengthy precipitation periods
Leaky underground structures (pipes, tunnels)
Underground flow retarders (buried structures, walls, rock outcrops)
Percent of land surface covered by pavement and buildings without ability to
recharge.
Nearby construction dewatering.
Changes to the existing surface drainage pattern due to new site topography,
trenches, infiltrators, bio-retention basins and subgrade structures.
o Groundwater impact based upon the data collected to date (Table II, Appendix A):
Normal groundwater levels found in soil is not expected to impact new foundation
excavations (Figure 4).
Lowest level floor slab should not be impacted if the building is set at or above
average existing site grade (Figure 4).
Footing excavations set below about El. 23 ft.+/- could be impacted by seasonal high
groundwater (Table IIA).
Underground utilities on some sites are designed to be installed deeper than
foundations, however such data has not been provided us to-date for this project.
Hydraulic Conductivity (K in GPD/ft.2):
Testing Performed: laboratory soil gradation testing was not undertaken for this study and
associated calculations and estimations of soil hydraulic conductivity (K) were not undertaken
for any site subsoil unit.
Initial Comments: the following soil data should be considered in initial estimations of K:
o Soil:
Uniform SP soil
USGS medium to fine sand with nearly absent coarse sand and gravel
Silt content (No. 200 sieve) likely less than 7%
o Soil density: depends on site location; see Figure 2, Figure 3 and Figure 4
Site Civil and Environmental Site Investigation and Remediation Structural Unit Impact:
Intrusive Environmental Testing and Remediation:
o Site civil and environmental exploration (test pits and test trenches) can damage
anticipated building structural unit bearing soils.
o Site remediation work can require removal of significant volumes of contaminated soil
materials from within proposed new construction footprints and inadvertently cause
structural unit bearing soil degradation.
Protection of Structural Unit Bearing Subgrade: to protect structural bearing areas, project
specifications should require:
o Test pit and test trench areas avoid proposed project footing and slab bearing zones.
o Test pit and test trench depths be limited to structural bearing depths minus one foot.
Proposed Dennis-Yarmouth Intermediate School 17 4 April 2018
South Yarmouth, MA GPI File No. 1814
VI. Preliminary Foundation Review and Recommendations:
Foundation System:
Impact to the Foundation System:
o The very loose to loose glacial fluvial soil found from near ground surface to a depth of
about El. 16 ft. (Appendix A, Figure 3) is unsuitable for foundation bearing.
o Figure 4 illustrates a preliminary estimate of currently found acceptable bearing soil
elevation:
About El. 16 ft. south
About El. 25 ft. north
Most Economic Foundation Approach: two step approach
o Conventional shallow foundations (spread and continuous wall footings and lowest level
slabs-on-grade can be installed if the following steps are taken to prepare the site:
Employment of ground densification from working surface (say El. 28 ft.) is possible
to a depth of El. 20 ft. (up to 8 vertical feet) using the proper heavy duty vibrating
roller compactor. Densification of this sort would be able to remediate the loose near
surface subsoils within about 60% (preliminary estimate) of the building footprint
(Figure 4)
The remainder of the building footprint with deeper loose soil (Figure 4), would need
to be remediated by installation of a grid of ungrouted aggregate piers.
o Use of this two step site preparation approach should yield:
A site capable of providing 4 KSF net allowable soil bearing pressure for structural
design.
A subgrade upon which conventional slabs-on-grade can be installed.
Seismic Recommendations:
Seismic Site Hazard Review:
o Probabilistic Site Hard Analysis [PSHA Interactive Deagregation; Geologic Hazards
Science Center, US Geologic Survey; 2008 v.2]
Decimal site latitude and longitude utilized in this review: (41.6803° N, -70.1974° W).
Probability of magnitude 5 (M5.0) or greater earthquake occurrence within 50 miles of
the subject site within a 50-year building design life is considered relatively low
(<2 %+/-).
Proposed Dennis-Yarmouth Intermediate School 18 4 April 2018
South Yarmouth, MA GPI File No. 1814
o Area earthquake history:
Typical measured earthquakes within the past 40 years have magnitude ≤ 3.1 (1977).
Past significant earthquakes with area impact recreated from the geologic record:
Year Magnitude Location Intensity in Boston
1638 6.5 Central New Hampshire MMI: V-VII
1663 7.0 Charlevoix, Quebec MMI: V-VI
1727 5.6 Newbury, MA MMI: V-VI
1755 5.9 Scituate, MA MMI: IX
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MMI: Modified Mercalli Scale (subjective; observed damage and effects)
Seismic Site Class: The collected site subsoil data has been applied to the Massachusetts
adopted International Building Code (2015). According to the Building Code
o Analytic depth:
The upper 100 feet of soil and bedrock are subject to analysis.
Soil data on-site has been collected to up to 22 ft. depth.
Rock depth is expected to be as much as 100 ft. in this area
o Bedrock:
Site bedrock is a granitic rock (see “Area Bedrock Geology” report section).
Depth to intact bedrock as measured from likely BOF is > 10 ft. which eliminates
assignment of seismic Site Class A or B to this project.
The initial soil and rock data collected allows initial classification of this site as
seismic Site Class D.
Drainage and Waterproofing:
Building Foundation Walls: based upon preliminary level building, subsoil and groundwater
assumptions (pages 3-4, Figure 4, Table II and Table IIA) foundation drains are not needed.
Lowest Level Floor Slab: based upon existing project assumptions (pages 3-4, Figure 4,
Table II and Table IIA) no lowest level slab waterproofing is expected to be required.
Construction Dewatering:
Groundwater Impact:
o Based upon the data collected to-date, found seasonal high groundwater levels could
impact excavations for foundations shown on Figure 4.
o Refer to the “Groundwater Behavior” report sections for groundwater elevation limitations.
Re-use of Existing Site Subsoils as Engineered Fill:
Existing SP Glacial Fluvial Soils:
Re-use of these soils is likely limited to use as a sand fill.
Gravel content is insufficient for use of the SP sand as structural fill.
Thank you for inviting us to perform this initial study. Please contact us with any questions.
Sincerely yours,
Geotechnical Partnership, Inc.
Lisa R. Casselli, PE
Principal
Attachments: Appendix A: Logs of Test Borings B1 through B4
APPENDIX A: Logs of Structural Test Borings B1 to B4
Dennis-Yarmouth Intermediate School
South Yarmouth, Massachusetts
Geotechnical Partnership, Inc.
Swampscott, MA
File No. 1814
04-06-2018 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814 B1-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Test Boring No. B1
( 1 of 1)
Test Boring No. B1
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
26
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
DESCRIPTIONS
Topsoil (t = 14 in.)
Orange-brown, medium to fine SAND, few silt
(very loose; moist) --Glacial Fluvial--
3.0 ft.
Tan-yellow, medium to fine SAND, trace to few
silt, trace coarse sand (very loose to loose;
moist) --Glacial Fluvial--
5.0 ft.
Orange-brown, medium to fine SAND, trace to
few coarse sand, trace silt (loose; moist)
Orange-brown, medium to fine SAND, trace silt
(loose; wet) --Glacial Fluvial--
9.5 ft.
Tan, medium to fine SAND, trace silt (medium
dense; wet)
Tan, medium to fine SAND, trace silt, coarse
sand and fine gravel (medium dense; wet)
Tan, medium to fine SAND, trace silt and fine
gravel (medium dense; wet)
--Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%USCSSP
SP
SP
SP GRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count1
1
1
2
1
1
3
4
3
4
4
3
5
4
4
5
6
6
8
9
6
8
9
9
5
7
9
10
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=7'
Well Set: no
SS-1: 1' - 3'
R=11 N=2
SS-2: 3' - 5'
R=18 N=4
SS-3: 5' - 7'
R=20 N=8
Orange staining at
5 ft. on in sample
SS-4: 7' - 9'
R=24 N=8
SS-5: 10' - 12'
R=18 N=14
SS-6: 15' - 17'
R=17 N=17
SS-7: 20' - 22'
R=19 N=16
P=Penetrometer
Date Drilled : 4 April 2018
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 26 ft.+/- (datum?)
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
04-06-2018 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814 B2-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Test Boring No. B2
( 1 of 1)
Test Boring No. B2
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
28
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
DESCRIPTIONS
Topsoil (t = 12 in.)
Orange-brown, medium to fine SAND, few silt
(loose; moist) --Glacial Fluvial--
1.5 ft.
Tan-yellow to white-yellow, medium to fine
SAND, trace silt and coarse sand (loose; dry)
3.0 ft. --Glacial Fluvial--
Tan, medium to fine SAND, trace silt (medium
dense; dry) --Glacial Fluvial--
4.0 ft.
Tan, fine SAND, few silt (medium dense; dry)
Tan, fine SAND, few silt (medium dense; moist)
5.5 ft. --Glacial Fluvial--
Tan to tan-yellow, medium to fine SAND, trace
silt (medium dense; moist)
Tan to tan-yellow, medium to fine SAND, trace
silt and coarse sand (medium dense; moist to
wet)
Tan, medium to fine SAND, trace silt (medium
dense; wet)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
Tan, medium to fine SAND, trace silt, coarse
sand and fine gravel (medium dense; wet)
--Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%USCSSP
SP
SP
SP
SP GRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count3
4
4
5
5
6
5
7
5
5
6
7
7
7
8
11
5
7
8
10
6
6
8
9
8
7
9
9
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=7.5'
Well Set: no
SS-1: 1' - 3'
R=16 N=8
SS-2: 3' - 5'
R=23 N=11
SS-3: 5' - 7'
R=24 N=11
Rust lines from 5'
on in sample
SS-4: 7' - 9'
R=21 N=15
SS-5: 10' - 12'
R=19 N=15
SS-6: 15' - 17'
R=18 N=14
SS-7: 20' - 22'
R=14 N=16
P=Penetrometer
Date Drilled : 4 April 2018
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 28 ft.+/- (datum?)
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
04-06-2018 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814 B3-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Test Boring No. B3
( 1 of 1)
Test Boring No. B3
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
28
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
DESCRIPTIONS
Topsoil (t = 13 in.)
Orange-brown, medium to fine SAND, few silt
(very loose; moist) --Glacial Fluvial--
3.0 ft.
Tan-yellow, medium to fine SAND, few silt
(loose; moist)
Tan-yellow, medium to fine SAND, few silt
(loose; moist) --Glacial Fluvial--
6.0 ft.
Tan, fine SAND, few silt (medium dense; moist)
7.0 ft. --Glacial Fluvial--
Tan, medium to fine SAND, trace silt (medium
dense; wet)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
Tan, medium to fine SAND, trace silt (medium
dense; wet)
Tan, medium to fine SAND, trace silt and tan,
fine SAND, few silt (medium dense; wet) with
lenses tan, SILT (non-plastic), little fine sand
(wet) --Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%USCSSP
SP
SP
SP GRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count1
1
2
3
2
3
3
4
3
4
4
8
8
9
11
14
7
7
9
11
6
9
8
10
6
7
9
10
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=7'
Well Set: no
SS-1: 1' - 3'
R=13 N=3
SS-2: 3' - 5'
R=19 N=6
SS-3: 5' - 7'
R=21 N=8
Rust lines at 5.5'
SS-4: 7' - 9'
R=22 N=20
Rust stains at 7'
SS-5: 10' - 12'
R=20 N=16
SS-6: 15' - 17'
R=21 N=17
SS-7: 20' - 22'
R=17 N=16
P=Penetrometer
Date Drilled : 4 April 2018
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 28 ft.+/- (datum?)
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
04-06-2018 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814 B4-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Test Boring No. B4
( 1 of 1)
Test Boring No. B4
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
30
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
DESCRIPTIONS
Topsoil (t = 14 in.)
Orange-brown, medium to fine SAND, few silt,
trace coarse sand and coarse to fine gravel
(very loose; moist) --Glacial Fluvial--
3.0 ft.
Tan-yellow, mediium to fine SAND, trace silt
(loose; dry) --Glacial Fluvial--
5.0 ft.
Tan, fine SAND, few silt (medium dense; moist)
--Glacial Fluvial--
7.2 ft.
Tan, medium to fine SAND, trace silt, coarse
sand and fine gravel (medium dense; moist)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; moist to wet)
--Glacial Fluvial--
Tan, fine SAND, little medium sand, few silt
(medium dense; wet) --Glacial Fluvial--
16.5 ft.
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
--Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%USCSSP
SP
SP
SP
SP
SP GRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count1
2
2
4
4
3
3
4
4
7
7
8
7
8
8
9
6
6
7
8
6
8
9
10
6
8
8
10
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=11'
Well Set: no
SS-1: 1' - 3'
R=16 N=4
SS-2: 3' - 5'
R=16 N=6
SS-3: 5' - 7'
R=24 N=14
Orange stains at 5'
SS-4: 7' - 9'
R=24 N=16
Rust lines at 8.5'
SS-5: 10' - 12'
R=22 N=13
SS-6: 15' - 17'
R=18 N=17
SS-7: 20' - 22'
R=16 N=16
P=Penetrometer
Date Drilled : 4 April 2018
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 30 ft.+/- (datum?)
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
(THIS PAGE IS BLANK)
Geotechnical Partnership, Inc.
Geotechnical Engineering Services for New England
Since 1987 Lisa R. Casselli,PE Principal - A WBE Firm
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Subsurface Exploration Laboratory Soil Testing Geothermal Testing
Foundation Specialty Systems Ground Improvement Earthwork Testing
45 New Ocean Street – Suite A 805 Main Street
Swampscott, MA 01907 Sanford, ME 04073
Tel. 781/646-6982 Tel. 207/459-7800
18 February 2020
File No. 1814-01
PEADPC No. 71010.01.0
Perkins Eastman Architects DPC
20 Ashburton Place, Floor 8
Boston, MA 02108
Attention: Daniel Colli – Associate Principal
Subject: Design Phase Geotechnical Report
Proposed Dennis-Yarmouth Intermediate School
296 Station Avenue
South Yarmouth, Massachusetts
Dear Dan:
This geotechnical data
summary report outlines our
site background data review,
subsurface explorations, field
soil and groundwater testing,
engineering data summary,
analyses and calculations in
support of the design phase
development of the new
intermediate school building to
be erected in South Yarmouth,
Massachusetts (Figure 1)
Our design phase geotechnical
engineering data summary,
analyses and
recommendations follow.
296 Station Avenue 2 18 February 2020
South Yarmouth, MA GPI File No. 1814-01
I. Proposed Construction:
Existing Conditions:
Plan reference:
o Feasibility Study – Dennis Yarmouth Intermediate School – Existing Conditions Exhibit
(C-1) prepared by Doucet & Associates of Easthampton, Massachusetts; dated 26 March
2018; 100-scale.
o Dennis Yarmouth Intermediate/Middle School – Grading Plan (C-2) prepared by Doucet
& Associates of Easthampton, Massachusetts; dated 14 September 2018; 40-scale.
Direction, Datum, Elevation and Coordinates:
o Direction:
Plan north: Figure 2
Called north for this review: in the general direction of Christmas Way (Figure 1A).
o Datum and Elevation:
Vertical elevation datum: drawing C-2.
Site elevations:
Elevations used in this report were taken from drawing C-2.
Site area elevation change patterns can be seen in gross scale in Figure 1: 3D
USGS Area Topographic Plan was undertaken.
o Site Coordinates:
Latitude: 41.6803° N
Longitude: -70.1974° W
296 Station Avenue 3 18 February 2020
South Yarmouth, MA GPI File No. 1814-01
Existing Site Conditions:
o No attempt has been made to
undertake a history of this site.
Historic review is included in
research for Phase I
environmental site assessments.
o A 1905 historic property map
(Figure 1B) showed the site area
to be generally undeveloped.
o The proposed intermediate
school building site (Figure 1A,
Figure 2) is currently woodland
west adjacent to the Station
Avenue Elementary School.
o Existing general project site
elevation range: El. 22 ft. to
El. 28 ft. (from C-2).
o The immediate building site area
ground surface is relatively level
with shallow mounds and swales.
o No bedrock outcrops are visible
on-site or in adjacent areas. .
o Active underground site structures and utilities:
Non-existent on this undeveloped site.
The reviewed potential site utilities’ list is held by the test boring contractor.
Anticipated New Construction:
Plan Reference:
o Site Plan (AS-101) – Dennis Yarmouth Intermediate/Middle School, 296 Station Avenue
South Yarmouth MA; prepared by Perkins Eastman Architects of Boston, Massachusetts;
dated 5 April 2019.
o 3D Representations (A-002) – Dennis Yarmouth Intermediate/Middle School, 296 Station
Avenue South Yarmouth MA; prepared by Perkins Eastman Architects of Boston,
Massachusetts; dated 5 April 2019 (Figure 1C).
o Exterior Elevations (A-211, A-212, A-213, A-214, A-215) – Dennis Yarmouth
Intermediate/Middle School, 296 Station Avenue South Yarmouth MA; prepared by
Perkins Eastman Architects of Boston, Massachusetts; dated 5 April 2019.
o Elevator D1 & E1 (A-361) – Dennis Yarmouth Intermediate/Middle School, 296 Station
Avenue South Yarmouth MA; prepared by Perkins Eastman Architects of Boston,
Massachusetts; dated 5 April 2019.
296 Station Avenue 4 18 February 2020
South Yarmouth, MA GPI File No. 1814-01
Building Structural Information: as presently understood
o Building levels: (Figure 1C)
Two (2) above-grade levels
No below-grade levels
Elevators and stairways:
Elevators: two (D1, E1)
Stairways: five
o Foundation footings:
Interior column footings (assumed):
270 K applied total load (assumed)
Bottom of footing (BOF; Figure 4):
o Interior footings: 2 feet below top of lowest level floor slab (assumed)
o Exterior walls and columns (pilasters): assumed at recommended frost depth
Exterior wall footing: 7 KLF applied total load (assumed)
o Lowest level floor level (Figure 4):
Assumed uniform
1st floor finish floor elevation (FFE): El. 29 ft. (assumed)
o Elevator pits: elevator pits D1 and E1 base elevations appear equal to that of footing
recommended frost depth (A-361).
II. Subsurface Conditions:
Topographic Data:
Elevation Range: The general site area is relatively level to slightly to moderately sloping
(Figure 1: 3D USGS Area Topographic Plan).
296 Station Avenue 5 18 February 2020
South Yarmouth, MA GPI File No. 1814-01
Area Surficial Geology:
o Area surficial geology is the result of a complex interaction of glacial advance and retreat
and intrusive marine action.
o The project area lies within a relatively level glacial fluvial (outwash) plain bounded north
by glacial moraine formations left behind by glacial scour and melt, and east by post-
glacial wetlands.
Figure 1 shows the site lies within a relatively level ground area (glacial lowlands or
outwash areas) created by soil deposition from glacial ice meltwater.
Glacial moraines are an accumulation of glacial drift (silt, sand and gravel) within a
glaciated region by deposition and thrust of glacial ice (bulldozed material)
o The vertical scale in Figure 1 has been purposely exaggerated by a factor of 4X to better
reveal subtle site area topographic variation.
o According to area surficial geologic mapping utilizing the site latitude and longitude
coordinates [Massachusetts GIS, Surficial Geology; Commonwealth of Massachusetts
Office of Geographic Information; September 2012; updated 2018] the site was predicted
to be located upon the following native materials:
Glacial fluvial soil (Figure 1, Figure 1D); over
Glacial till and/or bedrock.
Area Water Bodies:
o Flax Pond: 2870 ft. east
o Long Pond: 3500 ft. south
o Plashes Pond: 6000 ft. west
o Other pond: 790 ft. north
o No other significant project area water bodies (ponds, lakes, rivers, streams) are mapped
on Figure 1.
o Mapped wetlands are found in lowlands as shown on Figure 1:
2400 ft. east and 2600 ft. southeast.
They may also may exist on the wooded section
of campus as localized woodland wetlands.
Anticipated Site Substrata: based upon the collected
geologic and topographic data, potential native site
subsoils were considered as follows:
o Organic deposits (peat)
o Glacial fluvial material (silt, sand and gravel).
o Glacial till (basal till; hardpan)
Area Bedrock Geology: [US Department of the Interior;
US Geological Survey, Massachusetts State Geologic
Map; 1998; see Figure 1E]
o Common area bedrock: alkali feldspar granite
A crystalline igneous rock.
Granitic rock with dominant alkali feldspar content
and lesser quartz
A hard, sound medium grained rock
o Other common area bedrock: amphibolite schist
Accompanies granitic gneiss (secondary);
A class of metamorphic rock with one of the
amphibole minerals (silica rock making minerals)
as the dominant constituent: bright green to
dark-green to black crystalline rock consisting
chiefly of amphibole and plagioclase feldspar;
can also be gray or whitish
296 Station Avenue 6 18 February 2020
South Yarmouth, MA GPI File No. 1814-01
Chief minerals include plagioclase feldspar and amphibole with minor garnet and
quartz.
Crystalline metamorphic rock with closely spaced foliations; foliation surface is rough
Tends to readily split into thin flakes or slabs
More evident visible crystallization than slates
With increase of feldspar and quartz and decrease of schist forming minerals pass
into more irregular foliated gneiss
o Other common area bedrock: granitic gneiss
Banded metamorphic rock; bands typically 1 mm to 1 cm thick); defined by texture
and arrangement of mineral grains
Layers are mineralogically unlike; coarse grained
Can originate from igneous rock (granite): recrystallization due to intense regional
metamorphism
Dominated by quartz and feldspar
Gray, well layered biotite-plagioclase-quartz gneiss
o Depth to bedrock:
No specific depth data was available from the MA GIS.
Area experience indicates bedrock is found at the base of thick glacial fluvial and thin
glacial till deposits.
Previous Test Borings
On-Site Borings:
o None of record were found on the subject site.
o No remnant groundwater wells were found.
Test Borings Undertaken for this Study
Dig Safe:
o General Dig Safe site underground utility clearance: was provided by Soil Exploration
Corp. of Leominster, MA.
The Dig Safe ticket numbers are held by the drilling contractor.
Utilities contacted: utilities’ list is held by Soil Exploration
o Test boring locations were laid out on-site by Soil Exploration.
Test borings:
o Drilling by Soil Exploration Corp: four (4) structural test boring (designated B1 through
B4) were drilled on-site during 4 April 2018 and an additional four (4) boring set on 18
February 2020 (B5 through B8).
o Refer to Figure 2: Subsurface Explorations for approximate as-drilled test boring
locations based upon the current building configuration and boring locations provided by
Perkins Eastman DPC.
o An ATV mounted drill-rig equipped with an auto-hammer (Photo 1), drilled and sampled
soils in the borings below grade.
Soil samples were taken in 2-foot increments.
Auger borings were drilled to 22 ft. depth below existing grade with:
Semi-continuous sampling and testing to 9 ft. depth and
Standard 5 ft. interval sampling and testing thereafter.
Digital Boring Logs:
o Recovered test boring soil samples were digitally logged by the geotechnical engineer in
accordance with ASTM D-5434-97: Standard Guide for Logging of Subsurface
Explorations of Soil and Rock.
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o Boring logs prepared by the engineer are presented in soil boring log sheets in
Appendix A. Logs detail soil type, soil boundary elevation and depth, soil density,
consistency, thickness, coloration, moisture and composition.
Photo 1: Auger Drilling Boring B4 with ATV Mounted Drill Rig
III. Geotechnical Testing:
Field Testing Performed:
Standard Penetration Tests (SPT)
(N70 in blows/foot)
Field Gradation Tests
Standard Penetration Testing (SPT):
SPT Presentation and Definition:
o A standard penetration test is defined
as the number of blows of a 140 lb.
hammer falling 30 inches to drive a
standard soil split spoon sampler 12
vertical inches. The number of blows
is designated as “N”
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o Standard penetration tests (SPT) N are summarized for the borings with elevation on the
boring logs in Appendix A and in Figure 4A, Figure 4B and Figure 4C.
o Field SPT N (blows/foot) is taken from blow count graphs provided on the boring logs.
o Standard penetration test N is plotted for the borings with elevation in Figure 3A and
Figure 3B.
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SPT Type:
o The borings drilled for this study (see Appendix A) used an auto-hammer sampler drive
system which delivers replicable, consistent energy for each blow.
o This is considered an improvement over older style drill rigs which utilized a rope and
cathead (donut) system and can have operator error or bias particularly when drilling in
dense soils (e.g. “short stroke” as driller tired, yielding artificially high N values).
SPT N Data Analysis of this Site:
o Note that in the plots of N with depth in Figure 3A and Figure 3B:
Boring N values are low within the glacial fluvial sand to as deep as El. 19 ft.+/-
(west) and El. 11 ft.+/- (east).
Boring N values increase somewhat with depth to a low medium dense condition
within the glacial fluvial sand material.
N values within the low medium dense glacial fluvial sand can be seen to vary slightly
and oscillate with depth below the weaker nearer surface materials.
o See also the N pattern variation with depth in Figure 4A, Figure 4B and Figure 4C as well
as in the blow count graphs on individual boring logs in Appendix A.
SPT N Engineering Uses: SPT data can be useful in determination of values of soil bearing
capacity, Young’s Modulus for footing settlement evaluation, as well as input to footing base
soil friction angle, seismic site class and slab subgrade modulus determination.
Corrected SPT N:
o Correction of raw field N70 values is performed based upon factors of soil overburden
pressure, drill rig sampler hammer type, drill rod length, sampler liner, etc. These are
employed to calibrate the field N values reported.
o Auto hammer field N values can require initial correction by a factor of about 1.15 when
using other hammer systems as a basis for calculations.
o Final N energy adjustment to N55 is required for performance of granular soil foundation
settlement calculations [refer to Joseph E. Bowles; Foundation Analysis and Design;
5th Edition; 1997].
Field Gradation Tests:
Test Use: Limited field gradation tests were performed to better determine the relative
percent of coarse gravel, fine gravel, coarse sand, and medium sand and fines (silt and fine
sand) in recovered granular soil samples (glacial fluvial sand soils).
Limitations:
o Field tests are limited to recovered dry or field air dried soil samples.
o 4-sieve method does not allow for separation of silt from fine sand.
Laboratory Soil Testing:
Test Boring Sampling:
o No laboratory soil particle gradation testing was undertaken for this review.
o Test boring samples are typically too small in volume for accurate lab testing.
o Taking samples from the auger flights can be inaccurate due to soil mixing as the soil
slowly migrates from the auger tip to ground surface.
Quality of Sampled Soils for Re-use: this subject is addressed in the report section entitled
“Re-Use of Existing Materials”.
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IV. Soil Strata:
Data Summaries:
Profile Data Summary: General summaries of soil substrata found in the subsurface
explorations are provided in Table I
Subsurface Summary Drawings:
o Refer to the subsoil profiles sketched in Figure 4A, Figure 4B and Figure 4C to gain an
initial overview of site subsurface soil conditions within the proposed building area from
north to south (Figure 1C, Figure 2).
o Subsoil profile orientation within the building area are given on the profile drawings.
Profile Field Descriptions: Detailed field soil descriptions are given in the boring logs
(Appendix A).
Table I: Exploration Summary
Test
Boring
No.
Ground
Surface
El. (ft.)
[C-2]
Depth
Drilled
(ft.)
Topsoil,
(ft.)
Loose
Glacial
Fluvial
(ft.)
Medium
Dense
Glacial
Fluvial
(ft.)
Glacial
Till
(ft.)
B1 27+/- 22.0 1.2 8.8 >12
B2 28+/- 22.0 1.0 3.0 >18
B3 26+/- 22.0 1.1 5.9 >15
B4 28+/- 22.0 1.2 4.8 >15
B5 28+/- 22.0 1.5 4.5 >16
B6 25+/- 22.0 1.7 4.3 >16
B7 22+/- 22.0 1.5 9.5 >11
B8 26+/- 22.0 1.0 5.0 >16
Soil Classification System Used for this Site Investigation:
Soil Classification System: Project soils have been classified in accordance with the Unified
Soil Classification System (USCS; MIT System). This is reflected in the test boring logs in
Appendix A.
Soil Descriptions: Soils are described in terms of color, grain size, moisture content, density
(coarse grained soils), consistency (fine grained soils), plasticity and cementation, as
appropriate.
Grain Size Boundaries (dia.) Common Size Example
Boulder >12 in. >Basketball
Cobble 3-in. to 12-in. Grapefruit size
Coarse Gravel ¾-in. to 3-in. Lemon size
Fine Gravel #4 Sieve (4.75mm) to ¾-in. Pea to grape size
Coarse Sand #10 Sieve (2 mm) to #4 Sieve Peppercorn size
Medium Sand # 40 Sieve (.425 mm) to #10 Sieve Sugar to table salt size
Fine Sand #200 Sieve (.075 mm) to #40 Sieve Powdered sugar size
Silt/Clay <#200 Sieve (.075 mm) Flour particle or finer
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Soil Moisture Content:
o Dry: no moisture noted
o Moist: some moisture observed
o Very moist: very moist, but not saturated (possible vadose zone)
o Wet: saturated above the liquid limit (likely groundwater zone)
Soil Density and Consistency:
o Density of coarse grained soils (non-plastic silts, sands, gravels): defined in terms of
standard penetration test blowcount N values (refer to the summary table at the bottom of
any boring log)
o Consistency (plastic silts, clay, and organics): defined secondarily in terms of blowcount
N values and primarily with respect to field unconfined compressive strength in TSF (refer
to the summary table at the bottom of any boring log).
Soil Particle Percentage Field Designation: Relative soil particle size percentages (trace,
few, little, some, mostly [capitalized soil unit]): refer to summary table at bottom of any boring
log. These are more accurately tallied by laboratory soil particle gradation tests.
Subsoil Classes on this Site: USCS soil type designations utilized in this report:
o AR = man placed fill; artificial soil stratum
o SP = glacial fluvial sand
o SM = glacial fluvial sandy silt
o GT = glacial till
o GT = granitic rock
Site Subsoil Descriptions:
Existing Fill (AR): no fill material was found at the boring locations drilled
Organics (OH, PT): no organic soils were encountered in the borings drilled
Glacial Fluvial (Glacial Outwash; SP):
o Definition and Source:
Refer to the “Area Surficial Geology” report section (page 5).
Glacial fluvial (outwash) plains are shown on Figure 1 and contain the subject site.
o Description: (Photo 2, Photo 3, Photo 4, Photo 5)
USCS:
SP: uniform (poorly graded) fine sand (Photo 5) or medium to fine sand (Photo
2, Photo 3, Photo 4) with limited gravel and silt content; typical site subsoils
SM: sandy silt; only observed at depth in boring B7 (El. 6.5 ft.)
Cohesionless.
Coloration: varied from orange-brown or tan-orange to tan-yellow to tan at the drilled
locations
Found below the surficial topsoil at all drilled boring locations and to the 22 ft. depth
drilled (Table I, Figure 4A, Figure 4B, Figure 4C, Appendix A).
These soils are water bearing (Figure 4A, Figure 4B, Figure 4C, Appendix A).
o Competency:
Generally very loose to loose in the upper portion of the deposit (Figure 3A,
Figure 3B, Figure 4A, Figure 4B, Figure 4C, Appendix A).
Low medium dense soil density in-situ at depth (Figure 3A, Figure 3B, Figure 4A,
Figure 4B, Figure 4C, Appendix A). The low medium dense SP sand is an
acceptable bearing material.
These soils will be exposed in site excavations (Figure 4A, Figure 4B, Figure 4C).
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Photo 2: Near Surface Glacial Fluvial Sand Photo 3: Likely Glacial Fluvial Bearing Soil
Photo 4: Medium Dense Glacial Fluvial Sub-Layer Photo 5: Fine Grained Glacial Fluvial Sub-Layer
Glacial Till: glacial till was not encountered to the maximum depth drilled (22 ft.) on-site.
Bedrock:
o Occurrence:
No rock outcropping was noted either on-site or on nearby properties.
Depth to bedrock: bedrock was not found to the 22 ft. depth drilled on-site.
o Rock types: refer to “Area Bedrock Geology” report section (pages 5-6) and Figure 1E.
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Photo 6: Soil rust lines Photo 7: Soil rust stains with lines
Photo 8: Saturated (water bearing) glacial fluvial soil
V. Groundwater Behavior
Free Water:
o Wet (saturated) soil was encountered in
the glacial fluvial sand layer in all site
borings (Photo 8).
o Site groundwater is unconfined.
o The site lies within a mapped significant
groundwater aquifer (refer to Figure 5:
Area Groundwater Aquifers).
o No groundwater monitoring wells were
found on-site. No wells were installed in
the borings due to the depth of found
groundwater.
o Table II and Table IIA summarize the site
groundwater data collected.
Table II: Groundwater Observations in Drilled Test Borings
---------------------------------------------------------------------------------------------------------------------------------
Loc. No. Elevation Date Observation Groundwater Depth Groundwater El.
---------------------------------------------------------------------------------------------------------------------------------
B1 27 ft.+/- 04/04/18 Wet Soil 7.0 ft. 20.0 ft.+/-
B2 28 ft.+/- 04/04/18 Wet Soil 7.5 ft. 20.5 ft.+/-
B3 26 ft.+/- 04/04/18 Wet Soil 7.0 ft. 19.0 ft.+/-
B4 28 ft.+/- 04/04/18 Wet Soil 11.0 ft. 17.0 ft.+/-
B5 28 ft.+/- 02/18/20 Wet Soil 9.5 ft. 18.5 ft.+/-
B6 25 ft.+/- 02/18/20 Wet Soil 7.5 ft. 17.5 ft.+/-
B7 22 ft.+/- 02/18/20 Wet Soil 7.0 ft. 15.0 ft.+/-
B8 26 ft.+/- 02/18/20 Wet Soil 10.0 ft. 16.0 ft.+/-
---------------------------------------------------------------------------------------------------------------------------------
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Table IIA: Indications of Seasonal High Groundwater in the Drilled Borings
---------------------------------------------------------------------------------------------------------------------------------
Loc. No. Elevation Date Observation Groundwater Depth Groundwater El.
---------------------------------------------------------------------------------------------------------------------------------
B1 26 ft.+/- 04/04/18 Rust Stains 5.0 ft. 21.0 ft.+/-
B2 28 ft.+/- 04/04/18 Rust Lines 5.0 ft. 23.0 ft.+/-
B3 28 ft.+/- 04/04/18 Rust Lines 5.5 ft. 22.5 ft.+/-
B4 30 ft.+/- 04/04/18 Rust Stains 5.0 ft. 25.0 ft.+/-
B5 28 ft.+/- 02/18/20 Rust Stains 5.0 ft. 23.0 ft.+/-
B7 22 ft.+/- 02/18/20 Rust Line 4.0 ft. 18.0 ft.+/-
---------------------------------------------------------------------------------------------------------------------------------
Groundwater Level Variation:
o Clear soil rust staining and/or rust lines were seen in 6 of 8 site soil borings.
Rust staining and mottling can give an indication of water level at or approaching
seasonal high groundwater level.
Soil rust lines and rust staining are summarized in Table IIA and noted on the boring
logs in Appendix A.
o Groundwater was found in glacial fluvial sand in all borings drilled (Table II; see also the
“Free Water” report sub-section and Figure 4A, Figure 4B, Figure 4C).
o Localized temporary and long term changes to groundwater level can be natural or man-
made. These changes source from activities such as:
The 2016 extreme drought condition and the relatively dry summer of 2017, although
ended may still have lingering influence. Wet early and late year periods were noted
in 2019, in contrast.
Winter drier season water levels.
Heavy rainstorms or lengthy precipitation periods
Leaky underground structures (pipes, tunnels)
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Underground flow retarders (buried structures, walls, rock outcrops)
Percent of land surface covered by pavement and buildings without ability to
recharge.
Nearby construction dewatering.
Changes to the existing surface drainage pattern due to new site topography,
trenches, infiltrators, bio-retention basins and subgrade structures.
o Groundwater impact based upon the data collected to date (Table II, Appendix A):
Normal groundwater levels found in soil is not expected to impact new foundation
excavations (Figure 4A, Figure 4B, Figure 4C).
Lowest level floor slab will not be impacted if the building is set at FFE El. 29 ft. as
indicated on C-2 (see also Figure 4A, Figure 4B, Figure 4C).
Any site excavations below about El. 23 ft.+/- could be impacted by seasonal high
groundwater (Table IIA).
Underground utilities on some sites are designed to be installed deeper than
foundations, however such data has not been provided us to-date for this project.
Hydraulic Conductivity (K in GPD/ft.2):
Testing Performed: laboratory soil gradation testing was not undertaken for this study and
associated calculations and estimations of soil hydraulic conductivity (K) were not undertaken
for any site subsoil unit.
Comments: the following soil data should be considered in initial estimations of K:
o Soil:
Uniform SP soil
USGS medium to fine sand with nearly absent to scant coarse sand and gravel
Silt content (No. 200 sieve) likely less than 7%
o Soil density: depends on site location; see Figure 2, Figure 3, Figure 4A, Figure 4B,
Figure 4C.
Site Civil and Environmental Site Investigation and Remediation Structural Unit Impact:
Intrusive Environmental Testing and Remediation:
o Site civil and environmental exploration (test pits and test trenches) can damage
anticipated building structural unit bearing soils.
o Site remediation work can require removal of significant volumes of contaminated soil
materials from within proposed new construction footprints and inadvertently cause
structural unit bearing soil degradation.
Protection of Structural Unit Bearing Subgrade: to protect structural bearing areas, project
specifications should require:
o Test pit and test trench areas avoid proposed project footing and slab bearing zones.
o Test pit and test trench depths be limited to structural bearing depths minus one foot.
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VI. Preliminary Foundation Review and Recommendations:
Foundation System:
Impact to the Foundation System:
o The very loose to loose glacial fluvial soil found from near ground surface to varying
elevations below grade, as summarized in Figure 4A, Figure 4B and Figure 4C, is
unsuitable for foundation bearing.
o Figure 4A, Figure 4B and Figure 4C illustrates estimates of found top of acceptable
bearing soil elevation:
North end of site: ranged from El. 23 ft. (west) to El. 20 ft. (east) (Figure 4A)
Central site area: ranged from El. 19 ft. (west and middle) to El. 11 ft. (east)
(Figure 4B)
South end of site: ranged from El. 22 ft. (west) to El. 20 ft. (middle) to El. 24 ft. (east)
(Figure 4C)
Foundation Approach:
o Ground surface elevations provided on C-2 have changed most initial test boring
elevation estimates from 2018. The revised site elevations coupled with drilling
supplemental test borings have changed the initial 2018 foundation recommendations.
o Assumption is that working base will be about El. 28 ft. to support a 1st floor slab FFE at
El. 29 ft. (per C-2) with a 6 in. to 7 in. thick slab base pad (compacted structural fill or
compacted ¾ in. crushed stone). This also assumes removal of surficial topsoil to top of
glacial fluvial sand (pages 14-15).
o Utilization of a very heavy duty vibratory drum roller assumed to be able to compact to
about 8 ft. depth as ground improvement should be conservatively assumed to usefully
compact to about 5 foot depth below working base (about El. 23 ft.).
o Based upon the bearing subsurface data summarized in the preceding section, the areas
in which acceptable footing bearing is at or above El. 23 ft. appears localized to the
northwest and southeast corners of the building area. Thus use of the very heavy duty
vibratory drum roller for ground improvement is unreliable for the building area for this
project.
o Conventional shallow foundations (spread and continuous wall footings and lowest level
slabs-on-grade) can be installed if remediated by installation of:
A grid of ungrouted aggregate piers below slabs (estimated at 10 ft. spacing+/-).
A grid of ungrouted aggregate piers below footings (estimated at 7.5 ft. wall footing
spacing)
o Ground improvement utilizing ungrouted aggregate piers would yield:
A 4 KSF net allowable soil bearing pressure below footings for structural design.
Utilization of slabs-on-grade throughout the structure.
o Pier lengths are estimated as up to about 15 ft.+/- as measured from working grade.
o Vibrations:
Non-displacement (pre-augered) type aggregate piers would be required to entirely
avoid generating vibrations capable of impacting nearby structures.
If displacement type piers are used, plan to limit vibrations to 0.5 in./sec. shear
velocity. A seismograph would need to be used at nearest on-site and off-site
structures to insure damage threshold shear velocities are not occurring and to aid
the installer in properly setting and maintaining the vibration level of the installation
mandrel’s vibratory hammer.
o For further information contact area installers:
Geopiers and geo-concrete columns: Helical Drilling, Inc.: 781/535-5832
Vibro-piers: Hayward Baker, Inc.: 617/306-5910
Aggregate piers/ Rigid Inclusions: HB Fleming: 207/799-8514
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Seismic Recommendations:
Seismic Site Hazard Review:
o Probabilistic Site Hard Analysis [PSHA Interactive Deagregation; Geologic Hazards
Science Center, US Geologic Survey; 2008 v.2]
Decimal site latitude and longitude utilized in this review: (41.6803° N, -70.1974° W).
Probability of magnitude 5 (M5.0) or greater earthquake occurrence within 50 miles of
the subject site within a 50-year building design life is considered relatively low
(<2 %+/-).
o Area earthquake history:
Typical measured earthquakes within the past 40 years have magnitude ≤ 3.1 (1977).
Past significant earthquakes with area impact recreated from the geologic record:
Year Magnitude Location Intensity in Boston
1638 6.5 Central New Hampshire MMI: V-VII
1663 7.0 Charlevoix, Quebec MMI: V-VI
1727 5.6 Newbury, MA MMI: V-VI
1755 5.9 Scituate, MA MMI: IX
------------------------------------------------------------------------------------------------------
MMI: Modified Mercalli Scale (subjective; observed damage and effects)
Seismic Site Class: The collected site subsoil data has been applied to the Massachusetts
adopted International Building Code (2015). According to the Building Code
o Analytic depth:
The upper 100 feet of soil and bedrock are subject to analysis.
Soil data on-site has been collected to up to 22 ft. depth.
Rock depth is expected to be as much as 100 ft. in this area
o Soils and bedrock:
Site bedrock is a granitic rock (see “Area Bedrock Geology” report section).
Depth to intact bedrock as measured from likely BOF is > 10 ft. which eliminates
assignment of seismic Site Class A or B to this project.
Expectation of increase in N value in glacial fluvial sand with depth (N>15) and
finding top of dense glacial till at about 60 ft. depth.
The soil and rock data collected indicates classification of this site as seismic
Site Class D.
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Seismic Design Factors: Preliminary estimated Earthquake Design Factors for Dennis/South
Yarmouth, Massachusetts (Massachusetts Amendments to the International Building Code
(2017; 9th Edition)) and IBC (2015):
Ss = 0.150g (short interval)
S1 = 0.054g (1-second interval)
Fa = 1.6 (site coefficient, classification as Site Class D)
Fv = 2.4 (site coefficient, classification as Site Class D)
Liquefaction:
Liquefaction Factors:
o Earthquake magnitude
o Earthquake amplitude (duration)
o Subsoil types and condition
Earthquake Magnitude:
o Figure 6 indicates that the probability of occurrence of an earthquake of magnitude 5 or
higher is low probable during a 50 year building design life.
o However, with a time period measured in centuries, earthquakes of magnitude 5 or
greater can be expected to occur as the earthquakes listed on page 20 indicate.
Earthquake Duration: This topic is beyond the scope of this review.
Subsoil Data Input: Review of the site subsoil profile was necessary for soil liquefaction
determination below structural units:
o Relevant test boring information: thicknesses of post compaction, loose to very loose
saturated silty to clean sands and non-plastic silts (SM, SP, SW, ML) glacial fluvial soil
layers were reviewed.
o Drill rig, site groundwater level and measured soil strength data with depth:
Drill rig hammer type: auto-hammer
Groundwater level: El. 23 ft.+/- (seasonal high estimate; see page 18)
Plotted field N70-values from the borings with depth (Figure 3A, Figure 3B).
Site Liquefaction Determination:
o Review of field auto hammer N70 from the borings with depth with respect to
Figure 1806.4c of the Massachusetts Amendments (2017; 9th Edition) for preliminary
liquefaction exclusion review compared to the estimated (seasonal high) groundwater
level.
o Result: liquefaction settlement is not of concern for this site were a 5M or greater
earthquake to occur here (see also Figure 6).
Structural Unit Frost Protection Depth:
Definition:
o Frost depth, freezing depth or frost line is the depth to which moisture in subsoil is
expected to freeze.
o Frost line varies in position (elevation) during seasonal freeze and thaw.
Massachusetts State Building Code Mandated Frost Protection Depth Changes:
o 7th Edition: “All foundations for buildings and structures shall extend to a minimum of 4 ft.
below (exterior) finished grades…”
o 8th Edition: Foundations and permanent building supports should be protected by
“extending below the frost line of the locality…” This suggests a 4 ft. frost depth is too
deep for coastal and southern areas and too shallow for northern or topographically
elevated locales.
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Site Structural Unit Frost Protection Depth:
o Frost line:
Average area frost line value: 0.9 m = 35.5 in. [J.E. Bowles; Foundation Analysis and
Design 5th Ed.; 1997; Figure 7-1].
Extreme frost line based upon state average: 53 in. [NAVFAC DM-7.1; Soil
Mechanics Design Manual 7.1; Figure 7; 1982].
Based upon the data collected to-date: recommended minimum site structural unit
frost protection depth in soil bearing for this property as measured from final adjacent
exterior grade: = 48 in. (4 ft.)
Direct bearing on bedrock does not require a minimum frost depth embedment.
Cold Weather Work Soil Protection:
o During cold weather construction earthwork the contractor must be prepared to provide
protection and/or thawing of foundation bearing soils against freezing.
Footings: insulation blankets and/or ground heating hoses should be utilized if
footing subgrade is exposed to freezing during cold weather periods.
Lowest Level Slabs:
Typically slab subgrade areas are thawed once basic framing is up by providing
heaters after enclosing the lowest level in plastic sheeting.
Then any remaining required grade raise fill, treatment and placement of the slab
base pad can be properly performed.
Foundation Footings:
Footings Bearing on Soil:
o All footings will bear upon ground improved SP sand.
o Any cap to installed aggregate piers will be as specified by the installer’s design
engineer.
o Interior footings should be designed to bear such that:
The top of footing (TOF) is ≥ 6 inches below bottom of grade slab.
They are founded below a minimum 1H:1V line as drawn from the bottom exterior
edge of adjacent footings or utilities.
o Minimum recommended footing widths:
Wall footings: 2 ft.
Column footings: 3 ft.
o Groundwater is not generally expected to be found within excavation zones on-site as per
the conditions listed in the “Groundwater Water Behavior” report section.
Seasonal high groundwater is not expected to be a factor during earthwork (page
18).
Seepage and influx into excavations following rain and melt events should be
anticipated in any case.
In any case the general contractor should follow the ground improvement contractor’s
design submittal’s requirements for providing a dry undisturbed working base.
Footing Soil Base Friction:
o Initial value for dry to moist SP sand ground improved to a medium dense condition is on
the order of 34°
o Final soil base friction value should be determined by the ground improvement
installation contractor’s design engineer.
Footings Bearing on Rock: none anticipated for this project
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Drainage and Waterproofing:
General Comments/Good Practice:
o Exterior grading at the building should be designed to carry surface water runoff away
from the structure.
o Planted areas or pavements should enhance the exterior grading performed to insure
surface water runoff beyond the building limits.
o Roof downspout water or other water should not be allowed to pool near the building.
Review Summary of Groundwater and Assumed Structural Unit Elevation Data for Drainage
and Waterproofing Design Assessment:
o Structural unit elevations:
Assumed exterior grade: about El. 28 ft.
Elevation of footings:
Exterior wall BOF: at frost depth, 4 ft. below exterior grade; El. 24 ft.
Interior walls or columns BOF: 2 ft. below 1st floor FF; El. 26 ft.
Assumed 1st floor slab: El. 29 ft. FFE
Assumed elevator pit base: 5 ft. below 1st floor FFE; El. 24 ft.
o Groundwater:
El. 23 ft. (seasonal high; see page 18)
In general, groundwater is not expected to be found in normal depth excavations.
Building Foundation Wall Drainage:
o Based on the data collected, foundation drains are not considered necessary.
o Frost wall waterproofing is unnecessary below grade.
Lowest Level Floor Slab Waterproofing or Damp Proofing:
o The base of the new building 1st floor slab is well above seasonal high water
o Under slab waterproofing (sump, membrane) is considered unnecessary.
o Normal damp proofing should be installed.
Elevator Pit:
Pit Foundation and Slab:
o The elevator pit base is assumed to bear at 5 feet below 1st floor slab finish floor.
o Elevator pit may be supported upon either:
Continuous wall footings with a slab-on-grade on aggregate pier improved
ground; or
A mat slab on aggregate pier improved ground.
o If a mat slab is used, use a subgrade modulus specified by the aggregate pier design
engineer.
o A minimum 12 inch thick base of structural fill or ¾ inch crushed stone should be set
below the slab-on-grade or structural mat on a Mirafi 140N geotextile (see also the
boldface section on page 25.)
Elevator Pit Drainage and Waterproofing: the elevator pit foundation base will be slightly
above estimated seasonal high water level (page 18).
o Water proofing is typically provided no matter what the groundwater conditions as the
elevator pit is the lowest elevation construction point on-site.
o Pit waterproofing should consist of installation of a positive side membrane system
such as PrePrufe (or equivalent).
o The elevator pit should require properly tied continuous waterstops in all construction
joints and if a mat, typically provide sufficient load to resist water buoyant forces (see
seasonal high water level, page 18). On this site under slab buoyant forces due to
seasonal high groundwater are expected to be zero vertical foot of uplift head.
296 Station Avenue 24 18 February 2020
South Yarmouth, MA GPI File No. 1814-01
Foundation Wall Design (Restrained Walls): no basement walls in design
Excavation and Bracing – Support of Excavation:
Excavation Depth ≤ 4 ft.:
o Common practice is to maintain a 1H:1V temporary side slope for shallow excavation
(≤ 4 ft.+/-) during construction.
o Benched steps can also be executed.
o Note that the sidewall stability may be undermined by minor sloughing if sidewall
bleeding occurs following storm events.
o Care must be taken not to undermine adjacent building foundations. Undermining occurs
if excavation intrudes upon adjacent building bearing soils determined by a 1H:1V line
downward and outward from the exterior base of the abutter’s foundation wall footing.
Excavation > 4 ft.:
o Site subsoil (SP sand) are considered an OSHA Class C soil.
o Thus excavations greater than 4 foot depth require a 1.5 H:1V layback of excavation
sidewalls.
Construction Dewatering:
Groundwater Impact:
o Based upon the test boring data collected to-date:
Found normal groundwater levels are not expected to impact expected excavations
for slabs and footings. It is also unlikely impact the elevator pit excavations.
Estimated seasonal high groundwater indicates excludes the possibility of such
groundwater intrusion during normal earthwork (page 18).
Refer also to the “Groundwater Behavior” report section and the summary provided
on page 23.
o Dewatering following melt and storm events should be expected. Pumping from filtered
sumps is required to avoid pumping fine soil particles (silt, fine sand) with water.
The contractor should provide adequate pumping and drainage to keep the work
area sufficiently dry as to not impact construction and cause disturbance of
foundation and slab subgrades.
Compaction of a SP sand subgrade is highly dependent on found soil water
content at the time of the work.
Harrowing to aid drying of overly wet subgrade should be expected.
Conversely addition of water to an overly dry subgrade should likewise be
expected.
Measurement of water content in-situ on-site can be performed using the
latest upgrade of the Troxler nuclear density meter (or equivalent).
Pumped Discharge:
o Discharge of pumped water should be performed in accord with all Town, Commonwealth
and Federal regulations.
o Assessment of permitting required by the USEPA, MWRA, or the Town should be
reviewed. Assessment by the Project Civil Engineer should be sought.
o It may be possible that pumped water could be discharged into an excavated on-site pit
in a controlled manner. Assessment by the Project Civil Engineer should be sought.
o For on-site drainage, it is likely that Town, Commonwealth and/or Federal discharge
permits may be needed. The contractor would be responsible for obtaining all permits
and any associated laboratory testing required for construction dewatering.
o Alternately the contractor might wish to consider use of a frac tank to temporarily store
pumped water at the work site.
296 Station Avenue 25 18 February 2020
South Yarmouth, MA GPI File No. 1814-01
Engineered Fills:
Crushed stone: ¾ in. clean, hard, durable crushed stone; uses:
o As a construction working pad
o As a surface protection below footings
o As a lowest level slab base pad.
Gravel: sandy gravel, bank run gravel; max. 3-in. gravel; limit No. 200 sieve content to about
6%
Structural fill: hard, durable sand and gravel;
o Common gradation limits for structural fill are given in the plot above.
o Structural fill gradation adjustments: gradations often specify
Minimum of 2% passing No. 200 to aid compaction
Maximum of 15% passing No. 200 with the assumption that work may not proceed
during wet conditions using this material (limit to < 12% passing No. 200, or Dense
Grade can be substituted (see below))
o Structural Fill Uses (in lieu of crushed stone):
To form a protective base directly below footings
As a replacement fill below structural units (over-excavated soft areas)
As a lowest level slab base pad.
Dense Grade Structural Fill/2-in. Crushed Stone: Structural fill/crushed stone meeting the
following minimum requirements
Sieve Size Percent Finer by Weight
2 in. 100
1½ in. 70 – 100
¾ in. 50 – 85
No. 4 30 – 55
No. 50 8 – 24
No. 200 3 – 10
296 Station Avenue 26 18 February 2020
South Yarmouth, MA GPI File No. 1814-01
o Dense grade structural fill uses:
As a readily workable replacement for conventional or recycled concrete type
structural fill when work must proceed during cold and/or wet conditions.
As a base pad for lowest level floor slabs and footings
Granular Fill: absent to minor gravel; primarily medium to fine sand with silt meeting the
following minimum requirements
Sieve Size Percent Finer by Weight
4 in. 100
No. 10 30 – 95
No. 40 10 – 70
No. 200 0 – 15*
-------------------------------------------------------------------
* May be as high as 20% if field compaction can be verified in dry conditions
o Granular Fill Uses:
As under slab fill below 2 ft. depth as measured from the slab base.
As densified trench backfill
Paved Areas:
A significant area of paved parking is planned for the southerly end of the new building.
Paved access drives are also included in design.
Based upon the test boring program (Appendix A) in general and test boring B1 in particular
the following paved area subgrade preparation suggestions are offered:
The paved area pavement section (bituminous layer(s), base gravel and subbase soil)
should be provided as designed by the Site Civil Engineer.
The engineer’s design should be able to rely upon a subgrade densified to complete frost
depth (4 feet) in SP sand improved to at least effective subgrade soil friction angle of 32°
if the following subgrade preparation steps are followed:
o Remove all topsoil to top of SP sand (Photo 2)
o Cut or fill subgrade to design subgrade elevations (i.e. elevation of base of pavement
section).
o Compact the entire paved area with a very heavy duty vibratory roller compactor as
follows (this compactor is defined as able to densify the subgrade to 8 ft. depth):
Note: if the area is determined to be too wet of optimum, harrow the exposed
area and allow to dry. Then seal top with 2 passes of the roller.
Note also: if the area is determined to be too wet of optimum, utilize a water
truck or other methods to dampen the ground.
Provide 10 passes (coverages) of the very heavy duty roller compactor east-west
Provide 10 passes (coverages) of the very heavy duty roller compactor north-
south.
Re-use of Excavated Existing Site Subsoils as Engineered Fill:
Existing Granular Fill: none
Existing SP Sand:
Refer to the “Glacial Fluvial” report section on pages 14-15.
Existing SP sand can be re-used on-site as “engineered fill”, the type of engineered fill
dependent upon the results of laboratory soil particle gradation testing of contractor
submitted recovered site SP sand samples. Likely re-use would likely be limited to sand
trench fill or less possibly “granular fill” as defined above.
As this soil is non-engineered, laboratory Proctor and associated field compaction tests
are not particularly useful. Re-use of this soil on-site would require compaction testing in
296 Station Avenue 27 18 February 2020
South Yarmouth, MA GPI File No. 1814-01
terms of experienced third party field observation of compaction equipment supported by
consideration of addition of water to dry soil or drying of saturated soils (harrowing) as
needed as previously described (page 24, boldface section).
Existing Sandy Silt Loam (Topsoil):
This material is likely limited to re-use as ordinary fill or common fill.
Common fill can only be reused on-site below planted areas.
Some earthwork specifications commonly in use provide strict silt content limits for
“common fill”.
Thank you for inviting us to perform this review. Please contact us with any questions.
Sincerely yours,
Geotechnical Partnership, Inc.
Lisa R. Casselli, PE
Principal
Attachments: Appendix A: Logs of Test Borings B1 through B8
APPENDIX A: Logs of Structural Test Borings B1 to B8
296 Station Avenue
South Yarmouth, Massachusetts
Geotechnical Partnership, Inc.
Swampscott, MA
File No. 1814-01
02-19-2020 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814 B1-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Date Drilled : 4 April 2018
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 27 ft.+/-
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Test Boring No. B1
( 1 of 1)
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
Test Boring No. B1
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
27
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
DESCRIPTIONS
Topsoil (t = 14 in.)
Orange-brown, medium to fine SAND, few silt
(very loose; moist) --Glacial Fluvial--
3.0 ft.
Tan-yellow, medium to fine SAND, trace to few
silt, trace coarse sand (very loose to loose;
moist) --Glacial Fluvial--
5.0 ft.
Orange-brown, medium to fine SAND, trace to
few coarse sand, trace silt (loose; moist)
Orange-brown, medium to fine SAND, trace silt
(loose; wet) --Glacial Fluvial--
9.5 ft.
Tan, medium to fine SAND, trace silt (medium
dense; wet)
Tan, medium to fine SAND, trace silt, coarse
sand and fine gravel (medium dense; wet)
Tan, medium to fine SAND, trace silt and fine
gravel (medium dense; wet)
--Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%USCSSP
SP
SP
SP GRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count1
1
1
2
1
1
3
4
3
4
4
3
5
4
4
5
6
6
8
9
6
8
9
9
5
7
9
10
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=7'
Well Set: no
SS-1: 1' - 3'
R=11 N=2
SS-2: 3' - 5'
R=18 N=4
SS-3: 5' - 7'
R=20 N=8
Orange staining at
5 ft. on in sample
SS-4: 7' - 9'
R=24 N=8
SS-5: 10' - 12'
R=18 N=14
SS-6: 15' - 17'
R=17 N=17
SS-7: 20' - 22'
R=19 N=16
P=Penetrometer
02-19-2020 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814 B2-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Date Drilled : 4 April 2018
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 28 ft.+/- (datum?)
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Test Boring No. B2
( 1 of 1)
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
Test Boring No. B2
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
28
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
DESCRIPTIONS
Topsoil (t = 12 in.)
Orange-brown, medium to fine SAND, few silt
(loose; moist) --Glacial Fluvial--
1.5 ft.
Tan-yellow to white-yellow, medium to fine
SAND, trace silt and coarse sand (loose; dry)
3.0 ft. --Glacial Fluvial--
Tan, medium to fine SAND, trace silt (medium
dense; dry) --Glacial Fluvial--
4.0 ft.
Tan, fine SAND, few silt (medium dense; dry)
Tan, fine SAND, few silt (medium dense; moist)
5.5 ft. --Glacial Fluvial--
Tan to tan-yellow, medium to fine SAND, trace
silt (medium dense; moist)
Tan to tan-yellow, medium to fine SAND, trace
silt and coarse sand (medium dense; moist to
wet)
Tan, medium to fine SAND, trace silt (medium
dense; wet)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
Tan, medium to fine SAND, trace silt, coarse
sand and fine gravel (medium dense; wet)
--Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%USCSSP
SP
SP
SP
SP GRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count3
4
4
5
5
6
5
7
5
5
6
7
7
7
8
11
5
7
8
10
6
6
8
9
8
7
9
9
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=7.5'
Well Set: no
SS-1: 1' - 3'
R=16 N=8
SS-2: 3' - 5'
R=23 N=11
SS-3: 5' - 7'
R=24 N=11
Rust lines from 5'
on in sample
SS-4: 7' - 9'
R=21 N=15
SS-5: 10' - 12'
R=19 N=15
SS-6: 15' - 17'
R=18 N=14
SS-7: 20' - 22'
R=14 N=16
P=Penetrometer
02-19-2020 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814 B3-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Test Boring No. B3
( 1 of 1)
Test Boring No. B3
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
26
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
DESCRIPTIONS
Topsoil (t = 13 in.)
Orange-brown, medium to fine SAND, few silt
(very loose; moist) --Glacial Fluvial--
3.0 ft.
Tan-yellow, medium to fine SAND, few silt
(loose; moist)
Tan-yellow, medium to fine SAND, few silt
(loose; moist) --Glacial Fluvial--
6.0 ft.
Tan, fine SAND, few silt (medium dense; moist)
7.0 ft. --Glacial Fluvial--
Tan, medium to fine SAND, trace silt (medium
dense; wet)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
Tan, medium to fine SAND, trace silt (medium
dense; wet)
Tan, medium to fine SAND, trace silt and tan,
fine SAND, few silt (medium dense; wet) with
lenses tan, SILT (non-plastic), little fine sand
(wet) --Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%USCSSP
SP
SP
SP GRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count1
1
2
3
2
3
3
4
3
4
4
8
8
9
11
14
7
7
9
11
6
9
8
10
6
7
9
10
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=7'
Well Set: no
SS-1: 1' - 3'
R=13 N=3
SS-2: 3' - 5'
R=19 N=6
SS-3: 5' - 7'
R=21 N=8
Rust lines at 5.5'
SS-4: 7' - 9'
R=22 N=20
Rust stains at 7'
SS-5: 10' - 12'
R=20 N=16
SS-6: 15' - 17'
R=21 N=17
SS-7: 20' - 22'
R=17 N=16
P=Penetrometer
Date Drilled : 4 April 2018
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 26 ft.+/-
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
02-19-2020 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814 B4-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Date Drilled : 4 April 2018
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 28 ft.+/-
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Test Boring No. B4
( 1 of 1)
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
Test Boring No. B4
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
28
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
DESCRIPTIONS
Topsoil (t = 14 in.)
Orange-brown, medium to fine SAND, few silt,
trace coarse sand and coarse to fine gravel
(very loose; moist) --Glacial Fluvial--
3.0 ft.
Tan-yellow, medium to fine SAND, trace silt
(loose; dry) --Glacial Fluvial--
5.0 ft.
Tan, fine SAND, few silt (medium dense; moist)
--Glacial Fluvial--
7.2 ft.
Tan, medium to fine SAND, trace silt, coarse
sand and fine gravel (medium dense; moist)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; moist to wet)
--Glacial Fluvial--
Tan, fine SAND, little medium sand, few silt
(medium dense; wet) --Glacial Fluvial--
16.5 ft.
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
--Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%USCSSP
SP
SP
SP
SP
SP GRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count1
2
2
4
4
3
3
4
4
7
7
8
7
8
8
9
6
6
7
8
6
8
9
10
6
8
8
10
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=11'
Well Set: no
SS-1: 1' - 3'
R=16 N=4
SS-2: 3' - 5'
R=16 N=6
SS-3: 5' - 7'
R=24 N=14
Orange stains at 5'
SS-4: 7' - 9'
R=24 N=16
Rust lines at 8.5'
SS-5: 10' - 12'
R=22 N=13
SS-6: 15' - 17'
R=18 N=17
SS-7: 20' - 22'
R=16 N=16
P=Penetrometer
02-19-2020 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814-01 B5-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814-01
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Date Drilled : 18 February 2020
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 28 ft.+/-
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Test Boring No. B5
( 1 of 1)
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
Test Boring No. B5
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
28
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
DESCRIPTIONS
USCSGRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count1
3
2
3
2
3
3
3
3
4
6
8
7
8
7
7
5
6
7
7
3
5
4
6
6
7
8
8
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=9.5'
Well Set: no
SS-1: 1' - 3'
R=19 N=5
SS-2: 3' - 5'
R=18 N=6
SS-3: 5' - 7'
R=18 N=10
Ruat stains
SS-4: 7' - 9'
R=21 N=15
SS-5: 10' - 12'
R=18 N=13
SS-6: 15' - 17'
R=21 N=9
SS-7: 20' - 22'
R=18 N=15
P=Penetrometer
Dark-brown, medium to find sandy SILT LOAM
(very loose; moist) --Topsoil--
1.5 ft.
Orange-brown, medium to fine SAND, little silt,
trace coarse sand and fine gravel (very loose;
moist) --Glacial Fluvial--
Tan, medium to fine SAND, trace coarse sand
(very loose; moist)
Tan, medium to fine SAND, trace coarse sand
and fine gravel (loose to medium dense; moist)
Tan, medium to fine SAND, trace coarse sand
and fine gravel (medium dense; moist)
Tan, medium to fine SAND, trace coarse sand
and fine gravel (medium dense; wet)
Tan, medium to fine SAND, trace coarse sand
and fine gravel (loose; wet)
Tan, medium to fine SAND, trace coarse sand
and fine gravel (medium dense; wet)
--Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%
AR
SM
SP
02-19-2020 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814-01 B6-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814-01
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Date Drilled : 18 February 2020
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 25 ft.+/-
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Test Boring No. B6
( 1 of 1)
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
Test Boring No. B6
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
25
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
DESCRIPTIONS
Topsoil
Tan-orange, medium to fine SAND, few silt
(very loose; dry) --Glacial Fluvial--
1.7 ft.
Tan, medium to fine SAND, few silt, trace
coarse sand (very loose to loose; moist)
Tan, medium to fine SAND, few silt, trace
coarse sand (very loose; moist)
Tan, medium to fine SAND, few silt, trace
coarse sand (medium dense; moist)
Tan, medium to fine SAND, few silt, trace
coarse sand (medium dense; moist to wet)
Tan, medium to fine SAND, few silt, trace
coarse sand (medium dense; wet)
--Glacial Fluvial--
15.0 ft.
Tan, fine SAND, little medium sand, trace silt
and coarse sand (medium dense; wet)
--Glacial Fluvial--
17.0 ft.
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
--Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%USCSSP
SP
SP
SP GRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count1
1
1
1
2
2
3
5
4
6
8
10
9
8
9
10
7
5
6
8
9
11
11
10
5
6
6
5
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=7.5'
Well Set: no
SS-1: 1' - 3'
R=9 N=2
SS-2: 3' - 5'
R=18 N=5
SS-3: 5' - 7'
R=21 N=14
SS-4: 7' - 9'
R=21 N=17
SS-5: 10' - 12'
R=21 N=11
SS-6: 15' - 17'
R=18 N=22
SS-7: 20' - 22'
R=18 N=12
P=Penetrometer
02-19-2020 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814-01 B7-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814-01
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Date Drilled : 18 February 2020
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 22 ft.+/-
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Test Boring No. B7
( 1 of 1)
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
Test Boring No. B7
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
22
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-1
DESCRIPTIONS
USCSGRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count2
3
5
6
4
4
4
5
4
3
2
4
4
5
5
5
4
6
7
8
5
6
6
8
4
5
7
9
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=7'
Well Set: no
B7 in athletic field
SS-1: 1' - 3'
R=20 N=8
SS-2: 3' - 5'
R=22 N=8
Rust line at 4'
SS-3: 5' - 7'
R=24 N=5
SS-4: 7' - 9'
R=24 N=10
SS-5: 10' - 12'
R=22 N=13
SS-6: 15' - 17'
R=19 N=12
SS-7: 20' - 22'
R=24 N=12
P=Penetrometer
Dark-brown, fine sandy SILT LOAM (loose;
moist) --Topsoil--
1.5 ft.
Tan to tan-orange, medium to fine SAND, trace
silt (loose; moist) --Granular Fill--
3.0 ft.
Dark-brown, SILT LOAM, some medium to fine
sand (loose; moist) --Buried Topsoil--
3.5 ft.
Tan, fine SAND, few medium sand, trace silt
(loose; moist) --Glacial Fluvial--
4.5 ft.
Tan-yellow, medium to fine SAND (very loose;
moist) --Glacial Fluvial--
6.5 ft.
Tan, medium to fine SAND, trace silt and
coarse sand (loose; wet)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet) with lenses
tan, SILT (non-plastic), little fine sand (wet)
--Glacial Fluvial--
15.5 ft.
Tan, SILT (non-plastic), little fine sand
(medium dense; wet) --Glacial Fluvial--
19.0 ft.
Tan, fine SAND, trace silt and tan, medium to
fine SAND, trace silt and coarse sand (medium
dense; wet) --Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%
AR
AR
AR
SP
SP
SP
SM
SP
02-19-2020 C:\Documents and Settings\Owner\My Documents\M-Tech\samples\1814-01 B8-22.borGeotechnical Partnership, Inc.
Swampscott, Massachusetts
Sanford, Maine
CLIENT: Perkins Eastman Architects DPC
File No. 1814-01
So. Yarmouth, Massachusetts
296 Station Avenue
PROJECT: Mattacheese Intermediate School
COHESIONLESS SOILS: 0-6 Very Loose 0-8 COHESIVE SOILS: 0-2 Very Soft (<0.25 TSF)
(DENSITY) 6-10 Loose 8-15 (CONSISTENCY) 2-4 Soft (0.25-0.5 TSF)
L: Sands; R: Gravels 11-30 Med-Dense 16-40 4-8 Med. Stiff (0.5-1.0 TSF)
>30 Dense 41-50 9-20 Stiff (1.0-4.0 TSF)
Very Dense >50 >20 Hard (>4.0 TSF)
Date Drilled : 18 February 2020
Boring Location : Refer to Report Figure 2
Drilling Contractor : Soil Exploration Corp.
: Leominster, MA
Driller : P. Goodale
Rock Core : ---
GPI Field Engineer : LR Casselli, PE, MASCE CSI
Elevation and Datum : El. 26 ft.+/-
Drilling Mud Utilized : Not necessary
Constant Water Head : Not necessary
Test Boring No. B8
( 1 of 1)
Drill Rig Type : ATV Mounted
Hammer Type : Auto
Cat-Head or Winch : NA
Soil Casing Type : 8 in. O.D. HSA
Sampler Type : SS - 1.375 in. I.D.; unlined
Sampler Hammer Fall : 140 lbs. / 30 in.
Test Boring No. B8
( 1 of 1)Depth in Feet0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Elev. in Feet
26
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
DESCRIPTIONS
USCSGRAPHICWater LevelSample No.1
2
3
4
5
6
7 Blow Count1
1
1
1
1
1
3
3
6
6
5
8
8
8
9
11
5
5
6
4
5
5
6
8
4
5
6
6
Blow Count
Graph
10 50 Averagequ-FieldAverage
qu-Field
(TSF)
0 1 2 3 4
REMARKS
Groundwater=10'
Well Set: no
SS-1: 1' - 3'
R=12 N=2
SS-2: 3' - 5'
R=15 N=4
SS-3: 5' - 7'
R=18 N=11
SS-4: 7' - 9'
R=21 N=17
SS-5: 10' - 12'
R=18 N=11
SS-6: 15' - 17'
R=21 N=11
SS-7: 20' - 22'
R=15 N=11
P=Penetrometer
Topsoil
Tan-orange, medium to fine SAND, trace silt
(very loose; dry)
Tan-orange, medium to fine SAND, trace silt,
coarse sand and fne gravel (very loose; dry)
5.0 ft. --Glacial Fluvial--
Tan, fine SAND, trace silt and medium sand
(medium dense; dry)
--Glacial Fluvial--
7.0 ft.
Tan, medium to fine SAND, trace silt (medium
dense; dry) with lenses tan, SILT (non-plastic),
few fine sand (moist)
--Glacial Fluvial--
10.5 ft.
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
Tan, medium to fine SAND, trace silt and
coarse sand (medium dense; wet)
--Glacial Fluvial--
Bottom of Exploration at 22 feet Depth
Particle Size: trace: <5%; few: 5-10%; little:
15-20%; some 30-45%; mostly: 50-100%
SP
SP
SP
SP