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FOUNDATION REPORT
PROPOSED ADDITION
FOR
UPPER PROVIDENCE TOWNSHIP BUILDING
UPPER PROVIDENCE TOWNSHIP,
MONTGOMERY COUNTY, PENNSYLVANIA
Prepared For: Richard Kapusta & Company 935 Landis Road Telford, Pennsylvania 18969
EEI Project Number: 29307.00
December 12, 2016
TABLE OF CONTENTS I. PROJECT OBJECTIVE AND SCOPE OF WORK ................................................. 1
II. SITE AND PROJECT DESCRIPTIONS ................................................................. 1
III. FIELD INVESTIGATION ........................................................................................ 3
IV. LABORATORY TESTING ...................................................................................... 4
V. SUBSURFACE CONDITIONS ............................................................................... 4
A. GEOLOGY ......................................................................................................... 4
B. SOIL / BEDROCK ............................................................................................. 5
C. GROUNDWATER .............................................................................................. 7
VI. SITE PREPARATION ............................................................................................ 7
VII. GEOTECHNICAL ANALYSIS ................................................................................ 8
VIII. FLOOR SUPPORT ................................................................................................. 10
IX. EXCAVATION METHODS ..................................................................................... 11
X. PAVEMENT DESIGN RECOMMENDATIONS ....................................................... 12
A. FLEXIBLE PAVEMENTS .................................................................................. 12
B. GENERAL PAVEMENT RECOMMENDATIONS .............................................. 12
XI. FILL AND COMPACTION ...................................................................................... 13
A. FILL CRITERIA ................................................................................................. 13
B. COMPACTION CRITERIA ................................................................................. 14
XII. LATERAL EARTH PRESSURES........................................................................... 15
XIII. SITE SEISMICITY .................................................................................................. 16
XIV. CONSTRUCTION QUALITY CONTROL ............................................................... 16
XV. LIMITATIONS ......................................................................................................... 16
APPENDIX
TOPOGRAPHIC MAP OF SITE GEOLOGIC MAP OF SITE BORING LOCATION PLAN
BORING PROFILES LABORATORY TESTING
BORING LOGS KEY TO BORING LOGS
Proposed Addition - 1 EEI Project Number 29307.00 Upper Providence Township
I. PROJECT OBJECTIVE AND SCOPE OF WORK
Earth Engineering Incorporated (EEI) completed the Foundation Report for the proposed
addition to the Upper Providence Township Building located in Upper Providence Township,
Montgomery County, Pennsylvania. The objective of this project was to investigate, document, and
analyze the subsurface conditions present at the site. Based upon the subsurface conditions,
recommendations regarding the design of the foundation system for the proposed addition, as well
as general earthwork and construction recommendations, were developed and are included within
this Report.
The scope of work for this project included a field investigation, a geologic analysis of site
conditions, laboratory testing of a soil sample obtained during the field investigation and a
geotechnical engineering analysis. The work was performed in accordance with EEI proposal
LV3840. This Report presents the results of our work.
II. SITE AND PROJECT DESCRIPTIONS
The Upper Providence Township Building is located at 1286 Black Rock Road in Upper
Providence Township, Montgomery County, Pennsylvania. The site is bordered by Black Rock
Road to the west, the township police administration building and commercial properties to the
south, with other township owned properties and athletic fields to the north and east. It should be
noted that U.S. Route 422 is located to the far northeast, beyond the park, and State Route 29 is to
the far south, beyond the commercial/industrial property. The existing township building is located in
the northern portion of the site, including asphalt driveways and parking areas on the south, east
and west sides of the building. The majority of the addition area is currently asphalt covered with
some landscaping. The topography of the proposed addition location is relatively flat. Ultimately,
the topography of the site slopes gently downward to the north. Based on the surface elevations at
each boring location, the relief across the footprint of the proposed addition area is approximately
two feet (2’). Plate 1, included with this Report, shows the location of the site on a topographic map
of the area. The following photographs show the site conditions at the time of the field
investigation:
Proposed Addition - 2 EEI Project Number 29307.00 Upper Providence Township
B-101 (Photograph 1) B-102 (Photograph 2)
B-103 (Photograph 3)
Based on information provided to EEI by Richard Kapusta Architect & Planners (RKAP), a
single story, 6,800 square foot, slab-on-grade addition to the Upper Providence Township Building
is proposed to be constructed at the site. The proposed addition is expected to have a finished floor
elevating that will match the finished first floor elevation of the existing building at 313.23 feet. The
addition will consist of a combination of masonry bearing walls and steel column construction. A
portion of the addition containing the new meeting hall, restrooms and an entrance lobby will be
constructed with a crawl space. The bottom of footing elevation for the crawl space will be
approximately eight feet (8’) below the finished floor elevation of 313.23 feet. Based on information
provided by RKAP, the maximum column and wall loads will not exceed 110 kips and 6 kips per
linear foot, respectively. Finally, driveway and parking areas are also proposed around the new
building. The proposed construction, in relation to the existing site features is shown on the Boring
Location Plan, EEI Drawing Number: 29307.00-A-101, included within the Appendix of this Report.
Proposed Addition - 3 EEI Project Number 29307.00 Upper Providence Township
III. FIELD INVESTIGATION
Three (3) borings, designated as B-101 through B-103, were conducted for this
investigation. The borings were performed on December 1, 2016, by Main Line Drilling Company of
Wayne, Pennsylvania. Supervision and monitoring of the boring program were performed by a
representative of EEI. The boring locations were field determined by a representative of EEI using
the provided plans. The ground surface elevation of each boring was determined by utilizing a
finished floor of a northern portion of the existing building as a reference datum. Based on the
provided plans, the existing finished floor elevation was 313.23 feet. The location of each test
boring is shown on the Boring Location Plan, included in the Appendix of this Report.
The test borings were advanced using two inch (2”) outer diameter (O.D.) split barrel
samplers and six inch (6”) O.D. hollow stem augers. Split-barrel samples, conducted in accordance
with American Society for Testing and Materials (ASTM) standard D1586, were taken at regular
intervals throughout the depths of the borings. Standard Penetration Test (SPT) values were
recorded for each sample. The SPT values, which are a measure of soil density and consistency,
are the number of blows required to drive the two inch (2”) O.D. split-barrel sampler six inches (6”)
using a one hundred forty pound (140#) weight dropped thirty inches (30”). The number of blows
required to advance the sampler over the 12 inch interval from 6 to 18 inches is considered the "N"
value. The test boring logs, which provide sample depths, description of the materials encountered
and sampling data, are included in the Appendix of this Report. The information presented on
these logs was used to generate boring profiles that graphically represent the subsurface conditions
encountered at the boring locations. The Boring Profiles, EEI Drawing Sheet Number: 29307.00-A-
102, are also included within the Appendix of this Report.
The borings were conducted to auger refusal at depths ranging from 10.0 to 15.0 feet below
the existing ground surface. Auger refusal is typically interpreted as the drilling apparatus
encountering the bedrock surface. Hard augering, which is indicative of very dense soil conditions,
was encountered at each boring location at depths ranging from 6.5 to 11.5 feet below the existing
ground surface. Groundwater was not encountered within any boring locations conducted, to the
depths achieved. The total depth of each boring and the conditions encountered can be observed
on the Boring Logs and Boring Profiles, included in the Appendix of this Report.
Proposed Addition - 4 EEI Project Number 29307.00 Upper Providence Township
IV. LABORATORY TESTING
One (1) representative soil sample recovered during the subsurface investigation was tested
in the laboratory. The laboratory testing conducted on this sample consisted of classification, in
accordance with ASTM D2487, to verify visual classification and to establish engineering
parameters required for analysis. The tests performed include: Particle Size Analysis (ASTM
D422), Atterberg Limits Determination (ASTM D4318) and Natural Moisture Content (ASTM
D2216). A Unified Soil Classification System (USCS) Group Symbol and ASTM Group Name were
assigned to the soil sample based upon the laboratory testing. The results of the laboratory testing
conducted are presented in Table I. A gradation curve, numerically and graphically depicting the
results of the analysis, is presented in the Appendix of this Report.
TABLE I
LABORATORY RESULTSSample Location B-102
Sample Number S-2
Sample Depth, feet 2.0’-4.0’
Stratum I
Atterberg Limits
Liquid Limit Non Plastic
Plastic Limit Non Plastic
Plasticity Index Non Plastic
Natural Moisture Content (%) 12.6
Unified Soil Classification System (USCS) Group Symbol
ML
ASTM Group Name Silt
V. SUBSURFACE CONDITIONS
A. GEOLOGY
According to the Pennsylvania Department of Conservation and Natural Resources, PA
DCNR Interactive Map, reprinted November 30, 2016, the site is situated within an area underlain
by the Triassic Period Brunswick Formation (Geologic Symbol: Trb). Plate 2, included within the
Appendix, shows the location of the site on a geologic map of the area.
According to the Commonwealth of Pennsylvania, Topographic and Geologic Survey,
Engineering Characteristics of The Rocks of Pennsylvania, Fourth (4th) Series, Revised 1982, the
Brunswick Formation is typically composed of a reddish-brown shale, mudstone, and siltstone
which sometimes contains beds of green and brown shale with red and dark-gray argillite inter-
bedded in some places. The bedding within this formation is typically thin to flaggy. Fracturing and
jointing within this rock type are moderately abundant, usually closely spaced and exhibiting a
Proposed Addition - 5 EEI Project Number 29307.00 Upper Providence Township
blocky pattern. This rock type is moderately resistant to weathering and the overlying soil mantle is
moderately thick. Weathered fragments of this rock range in shape from elongated to blocky. The
ease of excavation ranges from easy in the completely to highly weathered rock to difficult in the
moderately weathered to fresh bedrock of the Brunswick Formation.
The split-barrel samples of the soil and weathered rock fragments confirm the presence of
the Brunswick Formation shale on this site.
B. SOIL / BEDROCK
The soil samples obtained during the field investigation were examined and visually
classified by EEI, both in the field and in the laboratory. Based upon the classifications and the
laboratory testing conducted, a generalized subsurface profile was developed for this site. One (1)
material designated as FILL and three (3) naturally-occurring strata were characterized by EEI to
exist at the site. Topsoil was encountered at the surface of each boring location, to depths ranging
from 0.3 to 0.4 feet below the existing ground surface.
Cross-sections of each boring, displaying the various strata, as well as other information
obtained from the field investigation, are included within the Appendix on the Boring Profiles. The
subsurface information observed is also shown on the Boring Logs. A general description of the
materials encountered is as follows:
FILL
The material designated as FILL is visually described as brown to gray sandy silt with trace
root fibers. The FILL material was encountered at each boring location, which extended to depths
ranging from 1.0 and 3.0 feet below the existing ground surface. The SPT (N) values recorded
during the sampling of this material ranged from 4 to 12 blows on the sampling barrel per foot of
penetration. The SPT (N) results indicate that the FILL materials are loose to medium dense.
STRATUM I
The soil designated as Stratum I is visually described as red brown silt to sandy silt. As
determined by laboratory testing, the USCS Group Symbol for a representative sample of this
material is ML. The assigned ASTM Group Name is Silt. The Stratum I soil was encountered at
each boring locations, which extended to depths ranging from 4.5 to 6.5 feet below the existing
ground surface.
The SPT (N) values recorded during the sampling of this material ranged from 10 to 26
blows on the sampling barrel per foot of penetration. The SPT (N) results indicate that the Stratum I
soil is medium dense.
Proposed Addition - 6 EEI Project Number 29307.00 Upper Providence Township
STRATUM II
The material designated as Stratum II is visually described as interbedded weathered
siltstone and sandstone in the form of red brown sandy silt to silty sand. This material was
observed to be encountered in a highly weathered state. The Stratum II material was encountered
at boring locations B-102 and B-103, and extended to depths of 9.0 (B-102) and 11.5 (B-103) feet
below the existing ground surface. The SPT (N) values recorded during the sampling of this
material ranged from 36 to 72 blows on the sampling barrel per foot of penetration. The SPT (N)
results indicate that the Stratum II material is dense to very dense.
STRATUM III
The material designated as Stratum III is visually described as weathered shale in the form
of red brown to gray sand and gravel. The Stratum III material was encountered at each boring
location, which extended to the conclusion of the borings at depths ranging from 10.0 to 15.0 feet
below the existing ground surface. The SPT (N) values recorded during the sampling of this
material ranged from 61 blows on the sampling barrel per foot of penetration to 50 blows with no
penetration. The SPT (N) results indicate that the Stratum III material is very dense.
BEDROCK
Auger refusal was encountered at each boring location at depths ranging from 10.0 to 15.0
feet below the existing ground surface. Auger refusal is typically interpreted as the drilling
apparatus encountering the bedrock surface. The corresponding bedrock elevations can be found
in Table II below:
TABLE II BEDROCK ELEVATIONS
Boring Number Surface Elevation* (Ft.) Depth to Auger Refusal (Ft.) Bedrock Elevation (Ft.)
B-101 310.4 10.0 300.4
B-102 308.7 10.5 298.2
B-103 308.6 15.0 293.6
Note: * The ground surface elevation of each boring was determined by utilizing the existing finished floor elevation of a northern portion of the existing building as a reference datum. Based on the provided plans, the existing finished floor elevation was 313.23 feet.
Proposed Addition - 7 EEI Project Number 29307.00 Upper Providence Township
C. GROUNDWATER
Groundwater was not encountered within any boring location conducted, to the depths
achieved. It must be noted that groundwater observations were made at the time of the drilling
operation and that groundwater table elevations may fluctuate with daily, seasonal, and climatic
variations. If groundwater is encountered during construction, the appropriate measures to be
taken for groundwater control during construction should be determined in the field at the time of
excavation, and is the responsibility of the contractor.
VI. SITE PREPARATION
EEI performed a cursory analysis of the excavations and fill placements necessary for the
development of this site using the existing site grades and the anticipated bottom of crawl space
footing elevation of approximately 305 feet. Based on this analysis, excavations ranging from 3 to 5
feet, and fill placements up to approximately 5 feet will be required to achieve the proposed grades.
Prior to the placement of the required structural fill, areas extending a minimum of ten feet
(10’) or twice (2x) the height of the proposed fill beyond the proposed construction should be
stripped of all vegetation, topsoil, root mats, and other deleterious materials, where applicable. The
stripping operation should be completed to the satisfaction of the on-site representative of the
Geotechnical Engineer of Record. Following removal of the surface materials and after excavation
to the proposed grades, the building pad should be proof-rolled and compacted. It is recommended
that a steel drum vibratory roller having a minimum static weight of ten (10) tons be utilized for this
purpose. Proof-rolling should be conducted with a minimum of two (2) passes in each direction with
a smooth drum roller in static mode. Proof-rolling and compaction procedures are necessary to
densify and verify the integrity of the upper zones of the soils. The proof-rolling effort is an important
aspect of the development of the site, as portions of the existing FILL materials were encountered
during the test boring operation; EEI anticipates that unstable areas will be encountered during the
proof-rolling effort. Any loose or unstable areas encountered during proof-rolling are most likely due
to excessive moisture within the soil matrix. These soils can be aerated and dried in-place.
Following adequate drying time, these soils can be densified in-place. Alternately, any loose or soft
zones of soil can be removed and replaced with structural fill, as outlined in the FILL AND
COMPACTION section of this Report.
Proposed Addition - 8 EEI Project Number 29307.00 Upper Providence Township
The need to excavate and replace the soft materials will be reduced if the development of
the site occurs during periods of dry and warm conditions, such as the summer months. During
these periods, the effectiveness of scarifying and aerating will be greatly enhanced while reducing
the need to over-excavate and replace soft soils. The proof-rolling effort should be observed and
evaluated in the field by a qualified representative of the Geotechnical Engineer of Record.
Due to the fine-grained nature of the existing soils, repeated construction traffic across the
site will lead to instabilities. Therefore, construction traffic should be limited across the site. The
site should be graded during development to convey surface runoff away from construction. The
work areas should be sealed by rolling on a daily basis to promote runoff. Careful grading and
management of surface water runoff will help minimize disturbance of the subgrade. Furthermore, it
is recommended that all construction areas, including those which were excavated to achieve the
planned subgrade elevation, be proof-rolled immediately prior to the placement of the sub-base
stone section and again before installation of the asphalt/concrete sections. This will allow for soft
and/or weak areas to be observed and remediated prior to slab and/or pavement construction.
VII. GEOTECHNICAL ANALYSIS
The results of the field investigation revealed that the general geotechnical cross-section of
the site consists of one (1) FILL material and three (3) residual strata above the shale bedrock. As
previously mentioned in the SITE AND PROJECT DESCRIPTIONS section of this Report, the
maximum column and wall loads will not exceed 110 kips and 6 kips per linear foot, respectively.
Loose existing FILL material was encountered at boring location B-101 which extended to a
total depth of 3.0 feet below the existing ground surface. The variable density of the FILL indicates
that this material was not placed and compacted in controlled lifts, under engineering supervision.
Engineering analysis of the site conditions indicates there is potential for settlements above
acceptable limits if the foundation and slab elements are placed on or above the FILL materials.
Therefore, any FILL shall be removed and replaced with structural fill prior to structural fill
placement required to establish the slab subgrade elevations. It should be noted that FILL material
can vary in density and composition over short lateral and horizontal distances. Following the
removal of the FILL materials, the underlying subgrade soils should be proof-rolled and densified, in
accordance with the SITE PREPARATION section of this Report.
Proposed Addition - 9 EEI Project Number 29307.00 Upper Providence Township
The natural soils are suitable for support of the proposed structure. However, if soft/loose
natural soils are encountered at the site during construction, foundation preparation measures may
also be necessary at the time of excavation. The soft/loose soils should be evaluated by the on-site
representative of the Geotechnical Engineer of Record. All soft/loose natural soils should be
removed and replaced with structural fill. The over excavation, if required, should be backfilled with
compacted lifts of structural fill, to the originally proposed foundation bottom elevation. The
structural fill should be placed and compacted to ninety eight percent (98%) of the material’s
maximum dry density in accordance with ASTM D698.
EEI recommends supporting the proposed structure utilizing a shallow foundation system,
bearing on the medium dense Stratum I soils and very dense Stratum II weathered rock and/or
properly placed structural fill and possibly Stratum III weathered rock. The following foundation
system and soil bearing capacity recommendations are provided by EEI, in addition to those
discussed above.
1. A foundation system consisting of strip and spread footings along with a
slab-on-grade floor system is recommended for the proposed addition.
2. The base of the strip and spread footings should be situated within the medium dense to very dense natural soils and/or newly placed and compacted structural fill as detailed in the FILL AND COMPACTION section of this Report. FILL material and/or soft/loose natural soils encountered at the footing bottom elevation should be removed and replaced with compacted lifts of structural fill, or lean concrete. Foundations shall not bear on or above existing FILL and/or soft/loose natural soils.
3. Following implementation of the site and foundation preparation recommendations, the foundations can be designed for a maximum allowable bearing capacity of 3,000 pounds per square foot. Regardless of the load criteria, a minimum eighteen inch (18”) wide strip footing and thirty six inch (36”) spread footing should be utilized.
4. Supported on the suitably dense natural soil and/or properly placed structural fill, total settlements are estimated not to exceed 1.0 inch. Differential settlements are estimated not to exceed 0.5 inch. These settlements were calculated using a bearing capacity of 3,000 pounds per square foot along with the provided column and wall loads (110 kips and 6 klf, respectively).
5. The elevation of the base of the new foundations should match the base elevation of the adjacent existing footings. Alternately, foundations bearing at different elevations should be positioned so that the base of the closest points of the adjacent foundation is located a minimum of one horizontal to one vertical (1:1) from each other. Care should be taken not to undermine existing foundations. Should foundations be undermined, underpinning or shoring will be required.
Proposed Addition - 10 EEI Project Number 29307.00 Upper Providence Township
6. The bottom of exterior footings and footings in unheated areas should be placed at least thirty six inches (36”) below the final exterior grade for protection from frost heave.
7. All footing bottoms should be tamped and completely cleaned of loose material or debris immediately prior to the placement of concrete. The foundation must be dry at the time of concrete placement.
8. The actual bearing conditions of the soil at the footing bottom elevations should be confirmed in the field during excavation, by inspection under the supervision of a Professional Engineer qualified in Geotechnical Engineering.
It should be noted that foundation excavation adjacent to the existing building will likely
encounter loose backfill material. Backfill material for exterior foundation walls is often not placed
and compacted under engineering control. Therefore, localized over-excavation adjacent to the
existing building foundation(s) should be anticipated. The extent of the over-excavation should be
field determined at the time of construction by a qualified representative of the Geotechnical
Engineer of Record.
VIII. FLOOR SUPPORT
Floor slabs for the building addition may be supported on approved soils and/or new
engineered fill placed and compacted over approved subgrade soils in accordance with the FILL
AND COMPACTION section of this Report. Due to the soft/loose FILL materials, overexcavation
and replacement is expected to be required for proper support.
Following stabilization, if required, as previously discussed, floor slabs for the proposed
building addition may be designed as a slab-on-grade system with a recommended Modulus of
Subgrade Reaction value of 150 psi/inch. The subgrade should be prepared in accordance with the
procedures described in this Report. In order to reduce capillary rise and damp floor slabs, a
granular subbase is recommended. The granular subbase will also provide uniform support
distribution between the subgrade soils and the base of the concrete slab. It is recommended that a
minimum of six inches (6”) of clean, coarse-graded aggregate (such as PADOT 2B or other
approved materials) be placed and compacted beneath all floor slab areas. The floor slabs should
be suitably reinforced to control shrinkage cracks. Proper joints should be provided at the interface
of the slab(s) and foundation walls so that a small amount of independent movement can occur
without causing damage.
Proposed Addition - 11 EEI Project Number 29307.00 Upper Providence Township
IX. EXCAVATION METHODS
Excavations ranging from 3 to 5 feet deep will be required to achieve the proposed footing
bottom elevation of the crawl space. The excavations at this site are expected to occur within the
FILL materials and residual soils. Based on the results of the drilling operation, the FILL material
and Stratum I soil as well as the upper portion of the Stratum II weathered rock will be easy to
excavate using conventional equipment and techniques.
Conversely, very dense weathered rock (Stratum II and Stratum III) was encountered at
each of the boring locations. The depths to the very dense weathered rock (Stratum II and Stratum
III), in addition to the depths to bedrock, at each testing location are presented in the Table III.
TABLE III
DEPTHS OF VERY DENSE WEATHERED ROCK AND BEDROCK
Boring Location
*Surface Elevation
(ft)
Proposed Elevation
(ft)
Depth to Very Dense Stratum II
(ft)
Stratum II Weathered
Rock Elevation
(ft)
Depth to Very Dense Stratum III
(ft)
Stratum III Weathered
Rock Elevation
(ft)
Depth to Bedrock
(ft)
Bedrock Elevation
(ft)
B-101 310.4 305.0 -- -- 6.5 303.9 10.0 300.4 B-102 308.7 305.0 5.0 303.7 9.0 299.7 10.5 298.2 B-103 308.6 305.0 4.5 304.1 11.5 297.1 15.0 293.6
Note: * The ground surface elevation of each boring was determined by utilizing the existing finished floor elevation of a northern portion of the existing building as a reference datum. Based on the provided plans, the existing finished floor elevation was 313.23 feet.
Removal of the very dense materials with a standard back-hoe will prove difficult and result
in slow excavation rates. Improved excavation rates, specifically within the very dense portions of
these weathered materials, will be realized utilizing a late model, high power track-mounted hoe in
lieu of a standard backhoe. Removal of the deeper portions of the very dense Stratum II weathered
rock, such as during trench excavation, may require hydraulic hammering, ripping or other rock
removal techniques.
Deeper excavations for utilities may also encounter the bedrock surface. The rock removal
may be aided by the typically closely spaced fractures within the bedrock. However, rock
excavation within confined foundation and utility trenches is expected to require hydraulic
hammering, ripping, or other rock removal techniques. The final determination of the rock removal
method should comply with all Township codes and generally accepted safety guidelines.
Proposed Addition - 12 EEI Project Number 29307.00 Upper Providence Township
As required, temporary slopes and support for excavations should be designed and installed
by the contractor in accordance with the Occupational Safety and Health Administration’s (OSHA),
Safety and Health Regulations for Construction, 29 CFR 1926, Subpart P. A competent person as
defined by the aforementioned regulation is required to confirm stability of all excavations during
construction. If required, the design of temporary bracing and shoring by the contractor needs to
consider an active earth pressure and passive earth pressure on the temporary shoring as
appropriate. Effects of any surcharges also need to be considered in the bracing design.
Permanent slopes should be designed at 3 horizontal to 1 vertical or flatter.
X. PAVEMENT DESIGN RECOMMENDATIONS
Flexible pavement areas are expected to be constructed over the natural Stratum I soils
and/or newly compacted structural fill placed in accordance with the FILL AND COMPACTION
section of this Report. The following pavement design parameters including a 20 year design life
and 18 kip Equivalent Single Axle Loading (ESAL) of 26,249 ESALs were used in our analysis.
Should these traffic estimates be different, EEI should be notified so that our recommendations can
be reviewed and if necessary revised.
A. FLEXIBLE PAVEMENTS
The following design recommendations for flexible pavement sections were based on the
above parameters, and correlations with soil types and densities encountered during drilling. Based
on these estimated pavement design parameters and an assumed California Bearing Ratio (CBR)
value of 3.0, EEI recommends the following flexible pavement sections at the site.
Light Duty - Pavement Sections - 20 Year Design
Layer Designation Material Specification Thickness Surface Course PADOT ID-2 Wearing 1.5 inches
Base Course PADOT BCBC 2.0 inches Subbase PADOT Type 2A Modified Aggregate 7.0 inches
B. GENERAL PAVEMENT RECOMMENDATIONS
All pavement areas should be evaluated and thoroughly proof-rolled prior to the placement
of the subbase stone. Any soft or unstable areas encountered during proof-rolling should be
compacted in-place or removed and replaced with structural fill as outlined in the SITE
PREPARATION and FILL AND COMPACTION sections of this Report. Due to the fine grained
natural of the residual soils, stabilization sections and/or over-excavation are anticipated to be
required prior to the subbase stone placement. Existing local pavement specifications should be
adhered to if they are more stringent than those provided herein.
Proposed Addition - 13 EEI Project Number 29307.00 Upper Providence Township
The previous pavement analysis was performed using the American Association of State
Highway and Transportation Officials (AASHTO) method of flexible pavement design and are based
on the assumption that the pavement subgrades are well compacted, stable, and otherwise suitable
for the placement of subbase and pavement materials. All pavement subgrade areas should be
evaluated and thoroughly proof-rolled prior to the placement of the subbase stone and again prior to
asphalt placement.
Unstable soil observed during proof-rolling that is attributed to excessive moisture can be
aerated and dried in-place. Following adequate drying time, the soils can be densified in-place.
The excessively moist state of the soil, if encountered, may require localized stabilization via soil
over-excavation. Once completed, it is assumed that periodic maintenance, such as patching and
sealing, is performed at regular intervals.
XI. FILL AND COMPACTION
A. FILL CRITERIA
Fill material which supports foundations, floor slabs, and pavements, as well as fill for
retaining wall backfill, is considered structural fill. Excavations required to achieve the anticipated
grades will make the existing FILL material, as well as the Stratum I soils, and possibly Stratum II
and Stratum III weathered rock available for reuse as structural fill material.
Based on visual observations, the existing FILL materials are considered suitable for use as
structural fill provided any deleterious materials (i.e., metal, wood, etc.) which are unsuitable for
reuse as structural fill are stockpiled separately and removed from the site or placed in non-
structural areas. EEI recommends that the FILL materials be further evaluated for reuse as
structural fill by a representative of the Geotechnical Engineer of Record, at the time of excavation.
One (1) sample of the Stratum I soil was tested in the laboratory for natural moisture
content. The result yielded a natural moisture content of 12.6 percent. Based on visual
observations supported by laboratory testing, this material was observed to be near optimum
moisture.
Based on visual observations, the Stratum II and Stratum III weathered rock are suitable for
reuse as structural fill in their current condition. However, portions of the residual soil and
weathered rock may be encountered above optimum moisture. These portions of the Stratum II
and Stratum III materials may need time to be aerated and dried prior to use as structural fill. Also,
rock fragments should be processed to less than three inches (3”) in size and mixed with suitable
soil materials during placement to provide a well-graded structural fill.
Proposed Addition - 14 EEI Project Number 29307.00 Upper Providence Township
The on-site soils will require careful moisture control as they are sensitive to moisture
changes. Materials stockpiled for use as structural fill should be graded to shed water and rolled to
maintain the soils. During periods of wet site conditions, travel upon the building pad and
construction areas should be limited to minimize disturbance of the subgrade which will lead to
instabilities.
Any structural fill imported to the site should meet the following criteria:
Free of organic matter, ash, cinders, frozen materials, and demolition debris.
Plasticity Index less than ten (10). Less than fifteen (15) percent by weight rock fragments larger than
three (3) inches, less than thirty (30) percent by weight larger than ¾ inches, and less than thirty (30) percent by weight smaller than the No. 200 sieve.
Meets the definition of clean fill according to PADEP Management of Fill Policy, Document Number 258-2182-773.
The criteria are provided as a general guideline for soil materials imported to the site. Soil
materials available for use as structural fill should be submitted to the Geotechnical Engineer of
Record for evaluation prior to use at the site.
B. COMPACTION CRITERIA
Structural fill should generally be placed in horizontal lifts not exceeding eight inches (8”) in
loose thickness and compacted with a sheepsfoot or smooth drum vibratory roller with a minimum
static weight of ten (10) tons. Where compaction by hand-operated equipment is necessary,
structural fill should be placed in horizontal lifts of six inches (6”) loose thickness. The optimum lift
thickness and number of repetitions necessary to achieve the required percentage compaction
values should be determined in the field with test passes of the chosen compaction equipment.
The fill material should be placed at its optimum moisture content (+/- 2%) as determined in
accordance with ASTM D698 and compacted to a minimum percentage of the maximum dry density
as indicated in Table IV.
TABLE IV COMPACTION CRITERIA
Fill Area Percent of Maximum Dry Density as
per ASTM Standard D698 Foundation Support and Slab on Grade 98
Retaining Wall, Paved Areas, Walkways and Berms
95
Non-Structural 92
Proposed Addition - 15 EEI Project Number 29307.00 Upper Providence Township
XII. LATERAL EARTH PRESSURES
The lateral earth pressure coefficients that may be used for designing below grade walls and
retaining walls, if necessary, are shown in Table V. Retaining walls that are restrained from
deflection should be designed for the at-rest (Ko) condition. Retaining walls that are free to deflect,
such as landscape walls, should be designed for the active (Ka) condition. Considered somewhat
conservative, the earth pressure data for the on-site materials was determined from the soil
classification testing and visual classification of the soil samples which was compared to generally
accepted and published values for the various properties.
EEI recommends that a drainage system be installed for walls constructed below grade.
The presence of a drainage system will serve to minimize hydrostatic pressures caused by water
trapped against the walls. If adequate drainage is not provided, the walls should be designed to
resist hydrostatic loads. Additionally, consideration should be given to any surcharge loads at the
top of walls.
TABLE V SOIL PROPERTIES FOR THE COMPUTATION OF LATERAL LOADS
FILL &
STRATUM I STRATUM II & STRATUM III
Effective Stress Angle of Friction – φ 28.0º 30.0º
Dry Unit Weight - γd 110.0 pcf 120.0 pcf
Submerged Unit Weight – γw 47.6 pcf 57.6 pcf Rankine Coefficient of Active Earth Pressure - Ka 0.36 0.33 Rankine Coefficient of Passive Earth Pressure - Kp 2.77 3.00 Rankine Coefficient of at Rest Earth Pressure - Ko 0.53 0.50
It should be noted that for the design of an Segmental Retaining Walls (SRW), the National
Concrete Masonry Association (NCMA) suggests that all soil placed within the reinforced zones of
the system have no more than 35% passing the #200 sieve. The soil classification, conducted by
EEI as part of this investigation, indicates that placement of the Stratum I soil in the reinforced zone
of an SRW is not permitted. However, additional testing should be conducted once the reinforced
backfill material is identified, namely a direct shear test (ASTM D3080). The results of this test may
provide more aggressive soil parameters to be used in retaining wall design, which may effectively
reduce retaining wall costs.
Proposed Addition - 16 EEI Project Number 29307.00 Upper Providence Township
XIII. SITE SEISMICITY
The 2009 edition of the International Building Code (IBC) specifies seismic design
requirements applicable to the structural design of the proposed building addition. In particular,
Chapter 16, Sections 1613 through 1620 are relevant to this structural design. This in turn requires
that the project site be classified geotechnically as either “Site Class” A through F based on Table
1613.5.2 of IBC 2009. In this regard, based on a comparison of the criteria of Table 1613.5.2 with
the field data accumulated during the drilling for this site in December 2016, the site should be
classified as Site Class “C”, which according to IBC 2009 indicates a “very dense soil and soft rock”
profile.
XIV. CONSTRUCTION QUALITY CONTROL
As documented within this Report, the anticipated construction will include significant
earthwork procedures and foundation construction activities. The quality of this work is an integral
part of the development of this site and directly impacts the validity of the recommendations
presented in this Report. Based upon past experience, the most cost effective and economical
earthwork inspection is obtained through the on-site presence of a qualified representative of the
Geotechnical Engineer of Record during the placement of structural fill and the installation of
structural elements. Therefore, it is recommended that the proof-rolling effort, excavation and
placement of fill, and verification of the installation of foundation elements be tested and confirmed
by Earth Engineering Incorporated.
XV. LIMITATIONS
The conclusions and recommendations contained in this Report are based upon the
subsurface data collected, and on details stated in this Report, as well as the assumption that the
subsurface conditions do not deviate appreciably from those disclosed by the test borings
performed.
Unless specifically indicated to the contrary in this Report, the scope of this Report is limited
only to investigations and evaluation of the geotechnical aspects of the site conditions, and does
not include any consideration of potential site pollution, contamination or other environmental
issues. This Report offers no facts or opinions related to potential pollution or contamination of the
site.
Proposed Addition - 17 EEI Project Number 29307.00 Upper Providence Township
The procedures followed for the subsurface exploration, analysis and conclusion
development followed generally accepted geotechnical engineering practices and make no other
warranties, either expressed or implied, as to the professional advice provided under the terms of
EEI’s agreement and included in this Report. The conclusions and recommendations presented in
this Report assume that recognized proper construction practices are followed throughout
construction and that a Professional Engineer qualified in geotechnical engineering is retained to
oversee the inspection of site preparations, proof-rolling, foundation construction, and other critical
earthwork operations.
It is emphasized that this analysis was made for the proposed addition to the Upper
Providence Township Building located in Upper Providence Township, Montgomery County,
Pennsylvania. Earth Engineering Incorporated does not assume any responsibility in using this
Report to generate foundation design recommendations other than at the specific site addressed.
Respectfully submitted, EARTH ENGINEERING INCORPORATED
Michael J. Carmosky Assistant Director ~ Lehigh Valley Division
Michael O. Meixell, P.E. Director of Engineering ~ Lehigh Valley Division
Paul J. Creneti, P.G. Director ~ Lehigh Valley Division G:\PROJECTS\29000\29307.00 - UP TOWNSHIP BUILDING - LV GEOTECH\REPORT\29307.00 - UPPER PROVIDENCE TWP. BLDG. REPORT.DOC
APPENDIX
PLATE 1 - TOPOGRAPHIC MAP OF SITE
Visit us at http://www.dcnr.state.pa.us
Created using PA DCNR Map Viewer Copyright 2011 Esri. All rights reserved Collegeville Quadrangle Map created on Wed Nov 30 2016
PLATE 2 - BEDROCK GEOLOGY MAP OF SITE
Visit us at http://www.dcnr.state.pa.us
Created using PA DCNR Map Viewer Copyright 2011 Esri. All rights reserved Collegeville Quadrangle Map created on Wed Nov 30 2016
Date:
F.F.E.= Finished Floor Elevation
UPPER PROVIDENCE TOWNSHIP BUILDINGUPPER PROVIDENCE TOWNSHIP, MONTGOMERY COUNTY, PENNSYLVANIA
FILL - Brown to Gray Sandy Silt with Trace Root Fibers
www.earthengineering.com
TOPSOIL
STRATUM III - Red Brown to Gray Sand and Gravel(Weathered Shale)
313.23'
STRATUM II - Red Brown Sandy Silt to Silty Sand(Interbedded Weathered Siltstone and Sandstone)
Lithology Graphics
0.4'
26
12/12/2016
290
305.0+/-
A-102SHEET:
STRATUM I - Red Brown Silt to Sandy Silt
B.C.S.F.E.= Bottom of Crawl Space Footing Elevation
F.F.E.=
B.C.S.F.E.=
308
300
298
296
294
292
290
314
310
306306
304
302
300
298
296
294
292
312
PREPARED FOR
EL
EV
AT
ION
(fe
et)
3.0'10
29307.00
302
BORING PROFILES
304
EARTHENGINEERINGINCORPORATED
Geotechnical Engineers & Geologists
314
312
310
308
Project Number:
61
Auger RefusalHard Augering
11.5'-15.0'
Auger RefusalHard Augering
9.5'-10.5'
B-102EL. 308.7'
10.5'
9.0'
5.0'
0.3'
4
72
6.5'
36
20
211.0'
2.2'
50/0''
60
71
50
B-103EL. 308.6'
15.0'
4.5'
0.4'
21
12
11.5'
Auger RefusalHard Augering
6.5'-10.0'
50/5''
50/5''
B-101EL. 310.4'
10.0'
12.6 Odor:
% Gravel: Coarse: 0.0 Fine: 1.9 Diameter, mm % Finer
% Sand: Coarse: 3.0 Medium: 3.9 Fine: 0.5 75 100.038.1 100.019.0 100.09.5 100.04.75 98.12.00 95.1
0.425 91.20.150 91.1
0.075 90.7
0.005 NR
0.001 NR
Gs: N/A Cu: N/A Cc: N/A
Project: LL: NP PL: NP PI: NP
Job #:
Client:
Sample:Depth:
Comments:
East Norriton, PA - (610) 277-0880 Central PA: (717) 697-5701 Southern NJ: (856) 768-1001Classification of Soils, ASTM D 2487-00 / D 2488-00
2.0'-4.0'
USCS Classification: ML, Silt
B-102 / S-2
AASHTO Classification: A-4
December 7, 2016
№ 200
Hydrometer AnalysisClay Size
Colloids
SAND
Coarse № 10Medium № 40
№ 100
Particle SizeUS Standard Sieve Size
GRAVELCoarse
3"1½"¾"
Fine
FineDilatency: N/R
⅜"№ 4
STRATUM I NP - Indicates Sample is Non Plastic
Upper Providence Township Building29307.00
Richard Kapusta Architects & Planners
Cementation: strong Dry Strength: medium
Reaction to HCl: N/R Toughness: N/R
Structure: homogeneous
Sand Description: sub-angular to subrounded, weathered, brown and gray
Consistency: very hard Hardness: N/R
As-rec'd water content: N/R
1.97.4
Gravel Description: sub-angular to subrounded, weathered, brown and gray
3" 1½" ¾" ⅜" №4 №10 №40 №100 №200
0
10
20
30
40
50
60
70
80
90
100
0.010.1110100
Per
cen
t P
assi
ng
Sie
ve
Sieve Opening, mm
Particle Size Analysis of Soils
149 Main Street, Emmaus, PA 18049Tel: 610-967-4540 Fax: 610-967-4488
50/5''
M
M
M
M
17
50/5''
9
12
14
15
3
4
6
6
1
2
2
3
310.0
10.0
6.5
3.0
0.4
Auger Refusal
S-4 - PP=3.25 tsf
Hard Augering 6.5'-10.0'
S-3 - PP=4.00 tsf
S-2 - PP=1.75 tsf
M
PP = Pocket Penetrometer (tsf=tons persquare foot)
-
FILL - Brown to Gray Sandy Silt withTrace Root Fibers
-S-5
S-4
S-3
S-2
S-1
sm
sm
ml
ml
cl-ml
300.4
303.9
307.4
S-1 - PP=2.00 tsf
-
-
-
WATER:
1
;
START 12/1/16
REMARKS
RE
CO
VE
RY
(Ft.
) US
CS
Geotechnical Engineers & Geologists
BLO
WS
/0.5
FT
.O
N S
AM
PLE
R
SA
MP
LE N
O./
TY
PE
/CO
RE
RU
N
TIME:DEPTH:
EQUIPMENT USED Truck Mounted Drill Rig - Mobile B-47
DATE:
DEPTH: 10.0'
DE
PT
H (
FT
)
BORINGLOG
DEPTH (feet)
PROJECT LOCATION Upper Providence Township, Montgomery County, Pennsylvania
PROJECT NUMBER 29307.00
SURFACEELEV. (FT) 310.4
NOT ENCOUNTERED
H2O
CO
NT
EN
T
DEPTH:
DRILLING METHODS 2 inch O.D. Split Barrel Sampler, 6 inch O.D. Hollow Stem Augers
RE
CO
VE
RY
(%)
CHECKED BY: MJC
PROJECT NAME Upper Providence Township Building
DATE: 12/6/2016
DATE:
www.earthengineering.com
DESCRIPTION
TIME:
ELEVATION (feet)
STRATUM III - Reddish-Brown to GraySand and Gravel (Weathered Shale)
STRATUM I - Reddish-Brown Sandy Silt
TOPSOIL
CASING: SIZE: 3 1/4 inch I.D.
0.3'
0.7'
0.9'
1.4'
0.9'
INSPECTOR NAME D. Folk
DRILLER NAME/COMPANY Bill Corcoran/Main Line Drilling Company
1
XDATE:
OF
EARTHENGINEERINGINCORPORATED
** D = DRY, M = MOIST, W = WET
RQ
D (
%)
AA
SH
TO
SHEET
;
END 12/1/16
GR
AP
HIC
LO
G
BORING NO. B-101
8.48.0
6.9
6.0
4.0
2.0
0.0
M
M
M
W
W
6
11
50
46
40
32
34
9
12
24
25
8
9
11
15
1
4
17
10
308.4
10.5
9.0
5.0
1.0
0.3
Auger Refusal
Hard Augering 9.5'-10.5'
S-5 - PP=4.25 tsf
S-3 - PP=4.25 tsf
-
Perched Water Was Present BeneathTopsoil Layer
S-1 - PP=2.00 tsf
PP = Pocket Penetrometer (tsf=tons persquare foot)
FILL - Brown to Gray Sandy Silt withTrace Root Fibers
S-5
S-4
S-3
S-2
S-1STRATUM I - Reddish-Brown Silt toSandy Silt
sm
ml
ml
ml
298.2
299.7
303.7
307.7
-
-
-
-
S-4 - PP=4.50 tsf
WATER:
1
;
START 12/1/16
REMARKS
RE
CO
VE
RY
(Ft.
) US
CS
S-2 - PP=2.75 tsf
Geotechnical Engineers & Geologists
BLO
WS
/0.5
FT
.O
N S
AM
PLE
R
SA
MP
LE N
O./
TY
PE
/CO
RE
RU
N
TIME:DEPTH:
EQUIPMENT USED Truck Mounted Drill Rig - Mobile B-47
DATE:
DEPTH: 10.5'
DE
PT
H (
FT
)
BORINGLOG
DEPTH (feet)
PROJECT LOCATION Upper Providence Township, Montgomery County, Pennsylvania
PROJECT NUMBER 29307.00
SURFACEELEV. (FT) 308.7
NOT ENCOUNTERED
H2O
CO
NT
EN
T
DEPTH:
DRILLING METHODS 2 inch O.D. Split Barrel Sampler, 6 inch O.D. Hollow Stem Augers
RE
CO
VE
RY
(%)
CHECKED BY: MJC
PROJECT NAME Upper Providence Township Building
DATE: 12/6/2016
DATE:
www.earthengineering.com
DESCRIPTION
TIME:
GR
AP
HIC
LO
GELEVATION (feet)
STRATUM III - Reddish-Brown to GraySand and Gravel (Weathered Shale)
STRATUM II - Reddish-brown Sandy Siltto Silty Sand (Interbedded WeatheredSandstone and Siltstone)
TOPSOIL
1.2'
1.5'
1.3'
1.0'
0.8'
ML
** D = DRY, M = MOIST, W = WET
OF
DATE:
DRILLER NAME/COMPANY Bill Corcoran/Main Line Drilling Company
1
X
INSPECTOR NAME D. Folk
BORING NO. B-102EARTHENGINEERINGINCORPORATED
AA
SH
TO
RQ
D (
%)
SHEET
CASING: SIZE: 3 1/4 inch I.D. ;
END 12/1/16
9.5
8.0
6.0
4.0
2.0
0.0
32
29
31
28
.
-
25
33
38
20
M
20
23
27
29
9
10
11
19
2
4
8
10
-
Hard Augering 11.5'-15.0'
50/0''
S-5 - PP=3.50 tsf
S-4 - PP=4.50 tsf
S-3 - PP=4.50 tsf
S-2 - PP=3.25 tsf
S-1 - PP=3.50 tsf
PP = Pocket Penetrometer (tsf=tons persquare foot)
FILL - Brown to Gray Sandy Silt withTrace Root FibersM
NA
M
M
M-
308.2
S-6
S-5
S-4
S-3
S-2
S-1
-
sm
ml
ml
ml
ml
293.6
297.1
304.1
306.4
-
-
;
START 12/1/16
REMARKS
RE
CO
VE
RY
(Ft.
)DEPTH: 15.0'
ELEVATION (feet)
DESCRIPTION
SHEET
SA
MP
LE N
O./
TY
PE
/CO
RE
RU
N
Auger Refusal
DEPTH:
EQUIPMENT USED Truck Mounted Drill Rig - Mobile B-47
DATE:
US
CS
GR
AP
HIC
LO
G
END 12/1/16
;
BLO
WS
/0.5
FT
.O
N S
AM
PLE
R
PROJECT NAME Upper Providence Township Building
BORINGLOG
DEPTH (feet)
PROJECT LOCATION Upper Providence Township, Montgomery County, Pennsylvania
PROJECT NUMBER 29307.00
SURFACEELEV. (FT) 308.6
NOT ENCOUNTERED
H2O
CO
NT
EN
T
DEPTH: TIME:R
EC
OV
ER
Y(%
)
1
WATER:
DATE: 12/6/2016
DATE:
www.earthengineering.comGeotechnical Engineers & Geologists
CHECKED BY: MJC
DRILLING METHODS 2 inch O.D. Split Barrel Sampler, 6 inch O.D. Hollow Stem Augers
TIME:
DE
PT
H (
FT
)
1.3'
STRATUM II - Reddish-brown Sandy Siltto Silty Sand (Interbedded WeatheredSandstone and Siltstone)
STRATUM I - Reddish-Brown Sandy Silt
TOPSOIL
AA
SH
TO
1.8'
STRATUM III - Reddish-Brown to GraySand and Gravel (Weathered Shale)
1.8'
1.3'
1.5'
15.0
11.5
4.5
2.2
0.4
0.0'
1
EARTHENGINEERINGINCORPORATED
** D = DRY, M = MOIST, W = WET
X
CASING: SIZE: 3 1/4 inch I.D.
RQ
D (
%)
BORING NO. B-103
INSPECTOR NAME D. Folk
DATE:
OF
DRILLER NAME/COMPANY Bill Corcoran/Main Line Drilling Company
13.5
10.0
8.0
6.0
4.0
2.0
0.0
INCHES
3/4"-3.0"
and
3.0"-12.0"
Loose
3/16"-3/4"
Dense
Clean Gravels (Less than 5% fines)
Over 50
> 12"
some
Clayey sands, sand-clay mixtures
Poorly-graded gravels, gravel-sand mixtures, littleor no fines
Well-graded gravels, gravel-sand mixtures, little orno fines
(more than 50% of material is larger than No. 200 sieve size)
(50% or more of material is smaller than No. 200 sieve size)
GC
SW
CLAY
Silty sands, sand-silt mixtures
SILT
SC
OL
Clayey gravels, gravel-sand-clay mixtures
CL
ML
soils; fine grained soils usually soft or very soft; granular soils exhibit no apparent cohesion
Silty gravels, gravel-sand-silt mixtures
SP
31 - 50
Moist
GeneralClassification
DESCRIPTIONSYMBOL
Slight moisture perceptible by touch; fine grained soils are usually firm;
No visible free water; sample may be cool to the touch; at or above optimum moisture;
Dr
>30
Damp
(tons/sq.ft.)
W
Dry
Very dense
Medium dense
Very loose
APPARENTDENSITY
SPT# Blows/ft
Da
No. 10
trace
Passing #200 Seive
Passing #200 Seive
#200 Seive-#40 Seive
#40 Seive-#10 Seive
KEY TO LOG OFBORINGS
AASHTO SOIL CLASSIFICATION
CONSISTENCY - FINE-GRAINED SOIL
PERCENT OR
little
silty soilsgravel and
sandSignificant Constituent
Materials
Sieve AnalysisPercent Passing
No. 40
Unconfined Compressive Strength
11 - 30
SANDS
Liquid limit50% or greater
COARSE-GRAINED SOILS
Inorganic silts, micaceous or diatomaceous finesandy or silty soils, elastic silts
Inorganic clays of low to medium plasticity, gravellyclays, sandy clays, silty clays, lean clays
SILTSANDCLAYS
Liquid limit lessthan 50%
SILTSANDCLAYS
50% or more ofcoarse fractionsmaller thanNo. 4 sieve
size
More than 50%of coarse
fraction largerthan No. 4sieve size
ASTM D 422-63 AND ASTM D2487-92
Peat and other highly organic soils
FINE-GRAINED SOILS
Well-graded sands, gravelly sands, little or nofines
COMPONENT NAME FOR VARIOUS
GRAVELS
Inorganic silts and very fine sands, rock flour, silty orclayey fine sands or clayey silts with slight plasticity
UNIFIED SOIL CLASSIFICATION AND SYMBOL CHART
Inorganic clays of high plasticity, fat clays
Gravels with fines (More than 12% fines)
Clean Sands (Less than 5% fines)
Sands with fines (More than 12% fines)
Organic silts and organic silty clays of low plasticity
35 max
Coarse SAND
Medium SAND
Fine SAND
OH
PT
Geotechnical Engineers & Geologists
EARTH
ENGINEERING
INCORPORATED
20 - 35%
www.earthengineering.com
GW
GM
SMSOIL MOISTURE
M
PROPORTION OF SOIL
51 max
PARTICAL SIZE RANGES
MH
3/32"-3/16"
Fine GRAVEL
Coarse GRAVEL
COBBLE
BOULDER
0 - 10%
COMPONENT NAME
GP
Organic clays of medium to high plasticity, organicsilts
35 max
Poorly graded sands, gravelly sands, little or nofines
0 - 4
CH
CONSISTENCY
COARSE-GRAINED SOILRELATIVE DENSITY
RELATIVEAMOUNT
DESCRIPTION
10 - 20%
Visible free water; usually soil is below water table; contains significantly more mosture than moist
HIGHLY ORGANICSOILS
granular soils have very little apparent cohesion
> 4.0
2 - 4
A-1-b
SPT# Blows/ft
A-2-4
Absence of moisture; dusty; completely dry to the touch
< 0.25
0.25 - 0.50
1.0 - 2.0
<2
40 max
Silt-Clay Materials(More than 35% of total sample
passing No. 200 sieve size)
6 max
finesand
Granular Materials(35% or less of total sample passing No. 200 sieve size)
NP
A-1-a
35 max
silty and clayeygravel and sand
10 max
36 min 36 min 36 min
A-2-5
35 maxNo. 200
5 - 10
Extruded between fingers when squeezed
Very stiff
Stiff
Medium stiff
Soft
Very soft
0.50 - 1.0
Molded by light finger pressure
Field Test
Molded by strong finger pressure
Readily indented by thumb but penetrated only with great effort
Readily indented by thumbnail
Indented with difficulty by thumbnail
41 min
granular soils might exhibit slight apparent cohesion
Hard
Plastic Index, Ip
Liquid Limit, wi
Characteristics ofFraction Passing
Wet
10 max
No. 40
41 min40 max
10 max
50 max
30 max
41 min
35 - 50%
2.0 - 4.0
GroupClassification
16 - 30
MOISTURE
10 max 36 min15 max
A-7-5A-7-6
A-2
11 min
9 - 15
11 min 11 min10 max
A-5 A-7
A-2-6 A-2-7
11 min
41 min40 max
A-4 A-6
5 - 8
40 max
A-3A-1
50 max
25 max
clayey soils
top related