HomeMy WebLinkAboutBEEBE CHRISTIAN SCHOOL - FDP - FDP170011 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGEOTECHNICAL SUBSURFACE EXPLORATION REPORT
BEE BE CHRISTIAN SCHOOL
A PORTION OF OUTLOT A – SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
SOILOGIC # 16-1131
June 22, 2016
Soilogic, Inc.
3050 67th Avenue, Suite 200 Greeley, CO 80634 (970) 535-6144
P.O. Box 1121 Hayden, CO 81639 (970) 276-2087
June 22, 2016
Ridgetop Engineering and Consulting Services
5255 Ronald Reagan Boulevard, Suite 210
Johnstown, Colorado 80534
Attn: Mr. Mike Beach, P.E.
Re: Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic Project # 16-1131
Mr. Beach:
Soilogic, Inc. (Soilogic) personnel have completed the geotechnical subsurface
exploration you requested for the proposed Bee Be Christian School to be constructed on
A Portion of Outlot A of the Spring Creek Farms North subdivision in Fort Collins,
Colorado. The results of our subsurface exploration and pertinent geotechnical
engineering recommendations are included with this report.
The subsurface materials encountered in the completed site borings consisted of a thin
mantle of vegetation and topsoil underlain by light brown to reddish brown/rust lean clay
with varying amounts of silt and sand. In general, the lean clay varied from medium stiff
to very stiff in terms of consistency, typically exhibited no to low swell potential at
current moisture and density conditions and extended to the bottom of all borings at
depths ranging from approximately 10 to 15 feet below grade. However, one (1) sample
of lean clay obtained from boring B-1 at a depth of approximately 2 feet below grade
exhibited moderate swell potential at in-situ moisture and density conditions.
Groundwater was not encountered in any of the completed site borings to the depths
explored at the time of drilling.
Based on the subsurface conditions encountered, results of laboratory testing and type of
construction proposed, it is our opinion the proposed school building could be supported
by conventional spread footing foundations bearing on natural, undisturbed lean clay with
low swell potential. The presence of moderately expansive near surface lean clay at the
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
2
location of boring B-1 completed in the approximate northwest corner of the proposed
school building will require care in mitigating the swell potential of these soils prior to
foundation, floor slab, exterior flatwork and pavement construction. If identified to any
appreciable extent at the time of construction through test pit and/or openhole
observation, extending footing foundations through these soils to bear on low swelling
clays at greater depth and/or overexcavation/backfill procedures will be required. The
depth and extent of any required overexcavation/backfill procedures can best be
established at the time of construction through test pit observation.
The site lean clay soils would be considered low volume-change (LVC) potential soils
and could be used as fill to develop the site. The reconditioned near-surface site lean clay
and properly placed and compacted fill consisting of on-site lean clay and/or similar soils
could be used for support of the building floor slabs, exterior flatwork and site
pavements. Pavement section design options for the site drive and parking area
pavements are included with this report. Other opinions and recommendations
concerning design criteria and construction details for the proposed site improvements
are also provided.
We appreciate the opportunity to be of service to you on this project. If you have any
questions concerning the enclosed information or if we can be of further service to you in
any way, please do not hesitate to contact us.
Very Truly Yours,
Soilogic, Inc. Reviewed by:
Wolf von Carlowitz, P.E. Darrel DiCarlo, P.E.
Principal Engineer Senior Project Engineer
36746 44271
GEOTECHNICAL SUBSURFACE EXPLORATION REPORT
BEE BE CHRISTIAN SCHOOL
A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
SOILOGIC # 16-1131
June 22, 2016
INTRODUCTION
This report contains the results of the completed geotechnical subsurface exploration for
the proposed Bee Be Christian School to be constructed on a portion of Outlot A of the
Spring Creek Farms North Subdivision in Fort Collins, Colorado. The purpose of our
exploration was to describe the subsurface conditions encountered in the completed site
borings and develop the test data necessary to provide recommendations concerning
design and construction of the proposed school building foundations and support of floor
slabs, exterior flatwork and site pavements. The conclusions and recommendations
outlined in this report are based on the results of the completed field and laboratory
testing and our experience with subsurface conditions in this area.
PROPOSED CONSTRUCTION
Based on the provided site plan, we understand the proposed school building will have a
plan area of approximately 19,000 square feet and be a single-story masonry structure
with steel frame infill, constructed as slab-on-grade. Foundations loads for the building
are anticipated to be relatively light, with maximum continuous wall loads on the order of
4.5 kips per lineal foot and individual column loads less than 125 kips. Paved drive and
parking areas are also anticipated as part of the proposed site improvements. Small grade
changes (on the order of 3 feet or less) are anticipated to develop finish site grades in
building and pavement areas.
SITE DESCRIPTION
The development property is described at A Portion of Outlot A of the Spring Creek
Farms North Subdivision located north of Nancy Gray Avenue between south Timberline
Road and Joseph Allen Drive and includes a total of approximately 3.3 acres. At the time
of our site exploration, the lot was heavily vegetated in grass vegetation and relatively
level with the maximum difference in ground surface elevation across the site estimated
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
2
to be less than 3 feet. Evidence of prior building construction was not observed in the
proposed construction areas at the time of our site exploration.
SITE EXPLORATION
Field Exploration
To develop subsurface information for the proposed site improvements, a total of eight
(8) soil borings were completed. Five (5) borings were advanced in the area of the
proposed building to a depth of approximately 15 feet below present site grade. Three (3)
additional borings were completed in the site pavement areas to a depth of approximately
10 feet below ground surface. The boring locations were established in the field by
Soilogic, Inc. (Soilogic) personnel based on a provided site plan, using a mechanical
surveyor's wheel and estimating angles from identifiable site references. The boring
locations should be considered accurate only to the degree implied by the methods used
to make the field measurements. A diagram indicating the approximate boring locations
is included with this report. Graphic logs of each of the auger borings are also included.
The test holes were advanced using 4-inch diameter continuous-flight auger, powered by
a truck-mounted CME-45 drill rig. Samples of the subsurface materials were obtained at
regular intervals using California barrel sampling procedures in general accordance with
ASTM specification D-1586. As part of the D-1586 sampling procedure, standard
sampling barrels are driven into the substrata using a 140-pound hammer falling a
distance of 30 inches. The number of blows required to advance the sampler a distance
of 12 inches is recorded and helpful in estimating the consistency or relative density of
the soils encountered. In the California barrel sampling procedure, lesser disturbed
samples are obtained in removable brass liners. Samples of the subsurface materials
obtained in the field were sealed and returned to the laboratory for further evaluation,
classification and testing.
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
3
Laboratory Testing
The samples collected were tested in the laboratory to measure natural moisture content
and visually or manually classified in accordance with the Unified Soil Classification
System (USCS). The USCS group symbols are indicated on the attached boring logs.
An outline of the USCS classification system is included with this report.
As part of the laboratory testing, a calibrated hand penetrometer (CHP) was used to
estimate the unconfined compressive strength of essentially cohesive specimens. The
CHP also provides a more reliable estimate of soil consistency than tactual observation
alone. Dry density, Atterberg limits, -200 wash and swell/consolidation tests were
completed on selected samples to help establish specific soil characteristics. Atterberg
limits tests are used to determine soil plasticity. The percent passing the #200 size sieve
(-200 wash test) is used to determine the percentage of fine grained materials (clay and
silt) in a sample. Swell/consolidation tests are performed to evaluate soil volume change
potential with variation in moisture content. The results of the completed laboratory tests
are outlined on the attached boring logs and swell/consolidation test summaries. Water
Soluble Sulfates (WSS) tests were completed on two (2) selected soil samples to evaluate
corrosive soil characteristics with respect to buried concrete and results discussed
subsequently in this report.
SUBSURFACE CONDITIONS
The subsurface materials encountered in the completed site borings can be described as
follows. Approximately 3 to 6 inches of vegetation and topsoil was encountered at the
surface at the boring locations. The vegetative soil layer was underlain by light brown to
reddish brown/rust lean clay with varying amounts of silt and sand. The lean clay varied
from medium stiff to very stiff in terms of consistency, generally exhibited no to low
swell potential at current moisture and density conditions, although one (1) sample
obtained from boring B-1 at a depth of approximately 2 feet below grade exhibited
moderate swell potential, and extended to the bottom of all borings at depths ranging
from approximately 10 to 15 feet below present site grades
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
4
The stratigraphy indicated on the included boring logs represents the approximate
location of changes in soil and bedrock types. Actual changes may be more gradual than
those indicated.
Groundwater was not encountered in any of the site borings to the full depths of
exploration, 10 to 15 feet below ground surface, when checked immediately after the
completion of drilling. Groundwater levels will vary seasonally and over time based on
weather conditions, site development, irrigation practices and other hydrologic
conditions. Perched and/or trapped groundwater conditions may also be encountered at
times throughout the year. Perched water is commonly encountered in soils overlying
less permeable soil layers and/or bedrock. Trapped water is typically encountered within
more permeable zones of layered soil and bedrock systems. The location and amount of
perched/trapped water can also vary over time.
ANALYSIS AND RECOMMENDATIONS
General
A majority of the lean clay soil samples tested in the laboratory exhibited no to low swell
potential at in-situ moisture and density conditions. However, one (1) sample of lean
clay obtained from boring B-1 at a depth of approximately two (2) feet below ground
surface exhibited moderate swell potential. The sample of soil obtained from the same
boring at a depth of approximately four (4) feet below grade exhibited low swell potential
at current moisture and density conditions, such that we expect the area is isolated and
limited to the upper 3 to 4 feet of near-surface soils.
Further evaluation of the extent of expansive near surface lean clay in the area of boring
B-1 should be completed at the time of excavation to help ensure footing foundations and
floor slabs will not be supported directly on or immediately above expansive materials.
If expansive near-surface lean clay soils are identified to any appreciable degree at that
time, extending footing foundations to bear on lean clay with low swell potential at
greater depth and/or overexcavation/backfill procedures to develop low volume change
foundation and floor slab support conditions would be required. The depth and extent of
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
5
expansive near-surface lean clays soils can best be established at the time of construction
through openhole observation.
The site lean clay soils were relatively dry at the time of drilling. While a majority of the
site lean clay tested exhibited no to low swell potential at in-situ conditions, we expect
the near-surface lean clay could be densified by heavy truck traffic during construction,
thereby inadvertently increasing the swell potential of these materials. Careful evaluation
of the subgrade soils, most notably in areas subjected to heavy truck traffic should be
completed prior to placement of any floor slab and exterior flatwork concrete and site
pavements to ensure they possess low swell potential. Areas of expansive soils that
develop during construction will require swell mitigation efforts.
Site Development
All existing vegetation and topsoil should be completely removed from the building,
exterior flatwork, pavement and any proposed fill areas. If moderately expansive lean
clay is identified in the area of boring B-1 or any other areas, those materials should also
be completely removed from beneath the school building footprint and below exterior
flatwork and site pavements at that time. Overexcavation (if required) should extend 8
inches laterally past the exterior edges of the overlying improvements for every 12 inches
of overexcavation depth. As previously outlined, the depth and extent of required
expansive soil removal (if any) can best be established at the time of site
development/excavation through test pit and/or openhole observation. After stripping
and completing all cuts and removal procedures and prior to the placement of any new
fill or overlying improvements, Soilogic recommends the exposed subgrade soils be
scarified to a depth of 9 inches, adjusted in moisture content and compacted to at least
95% of the materials standard Proctor maximum dry density. The moisture content of the
scarified subgrade soils should be adjusted to within the range of ±2% or standard Proctor
optimum moisture content at the time of placement and compaction.
Fill soils required to develop the site should consist of approved low volume change
(LVC) soils free from organic matter, debris and other objectionable materials. Based on
results of the completed laboratory testing, it is our opinion the site lean clay could be
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
6
used as fill to develop the site and removal area backfill. If it is necessary to import
additional material to the site for use as fill, those materials should consist of approved
LVC materials and be approved prior to use. Typically soils with a liquid limit less than
40 and a plasticity index less than 18 could be considered LVC. Import soils should
contain a minimum of 25% fines (material passing the #200 size sieve) in order to reduce
permeability. We recommend the site lean clay and/or similar materials be placed in
loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted as
recommended for the scarified subgrade soils above.
Care should be taken to avoid disturbing the reconditioned subgrade soils and placed fill
materials prior to placement of any overlying improvements. Soils which are allowed to
dry or out or become wet and softened or disturbed by the construction activities should
be removed and replaced or reworked in place prior to concrete placement and/or paving.
Foundations
Based on the materials encountered in the completed site borings and results of field and
laboratory testing, it is our opinion the proposed school building could be supported by
continuous spread footing and isolated pad foundations bearing on natural, undisturbed,
medium stiff to very stiff lean clay with low swell potential. Extending footing
foundations to bear on natural undisturbed soils with low volume change potential may
be required in some areas in order to develop consistent foundation bearing.
For design of foundations bearing on natural, undisturbed, medium stiff to very stiff lean
clay with low swell potential, we recommend using a maximum net allowable soil
bearing pressure of 2,000 psf. As a precaution, we recommend footing foundations be
designed to maintain a minimum dead load pressure of 650 psf or as high as practical on
the supporting soils.
Exterior footings should bear a minimum of 30 inches below finished adjacent exterior
grade to provide frost protection. We recommend formed strip footings have a minimum
width of 12 inches and isolated pad foundations have a minimum width of 24 inches in
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
7
order to facilitate construction and reduce the potential for development of eccentrically
loaded footings. Actual footing widths should be designed by a structural engineer.
For design of footing foundations and foundation walls to resist lateral movement, a
passive equivalent fluid pressure value of 250 pcf could be used. The top 30 inches of
subgrade could be considered a surcharge load but should not be used in the passive
resistance calculations. A coefficient of friction of 0.35 could be used between
foundation and floor slab concrete and the bearing soils to resist sliding. The
recommended passive equivalent fluid pressure value and coefficient of friction do not
include a factor of safety.
We estimate settlement of footing foundations designed and constructed as outlined
above and resulting from the assumed structural loads would be less than 1 inch.
Differential settlement could approach the amount of total movement estimated above. If
water from any source is allowed to infiltrate the foundation bearing soils, additional
movement of the foundations could occur.
Backfill placed adjacent to foundation walls should consist of LVC potential and
relatively impervious soils free from organic matter, debris and other objectionable
materials. Native site lean clay could be used as backfill in these areas provided the
proper moisture content is developed in those materials at the time of placement and
compaction. We recommend the native site lean clay and/or similar backfill soils be
placed in loose lifts not to exceed 9 inches thick, adjusted in moisture and compacted as
previously outlined in the “Site Development” section of this report.
Excessive lateral stresses can be imposed on unilaterally backfilled foundation walls
when using heavier mechanical compaction equipment. We recommend compaction of
unbalanced foundation wall backfill soils be completed using light mechanical or hand
compaction equipment.
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
8
Seismic Design
Based on the results of this investigation and Soilogic’s review of the International
Building Code (IBC - 2003), a soil profile type D could be used for the site strata. Based
on our review of United States Geologic Survey (USGS) mapped information, design
spectral response acceleration values of SDS = .218 (21.8%) and S
D1 = .092 (9.2%) could
be used.
Floor Slabs and Exterior Flatwork
The building floor slab and exterior flatwork could be supported directly on the
reconditioned subgrade soils with low swell potential and/or properly placed and
compacted fill or overexcavation/backfill soils (if required) developed as outlined above.
A modulus of subgrade reaction (k) value of 150 pci could be used for design of floor
slabs supported on reconditioned site lean clay and/or similar soils. Disturbed subgrades
or subgrade materials that have been allowed to dry out or become wet and softened
should be removed and replaced or reconditioned in place prior to concrete placement.
Floor slabs should designed and constructed as floating slabs, separated from foundation
walls, columns and plumbing and mechanical penetrations by the use of block outs or
appropriate isolation material. Additionally, we recommend any partition walls
supported above slabs-on-ground be constructed as floating walls to help reduce the
potential for differential slab-to-foundation movement causing distress in upper sections
of the building. A minimum 1½-inch void space is recommended. Special attention to
door framing, drywall installation, stair systems and trim carpentry should be taken to
isolate those elements from the floor slabs, allowing for some differential foundation to
floor slab movement to occur without transmitting stresses to the overlying structure.
Depending on the type of floor covering and floor covering adhesive used in finished
slab-on-grade areas, a vapor barrier may be required immediately beneath the floor slabs
in order to maintain flooring product manufacturer warranties. A vapor barrier would
help reduce the transmission of moisture through the slabs, however, the unilateral
moisture release caused by placing concrete on an impermeable surface can increase slab
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
9
curl. The amount of slab curl can be reduced by careful selection of an appropriate
concrete mix. Slab curl cannot be eliminated. We recommend the owner, architect and
flooring contractor consider the performance of the slabs in conjunction with the
proposed flooring products to help determine if a vapor barrier will be required and
where best to position the vapor barrier in relation to the floor slabs. Additional guidance
and recommendations concerning slab on grade design can be found in American
Concrete Institute (ACI) section 302.
Pavements
Pavement subgrades should be developed as outlined in the “Site Development” section
of this report. Site pavement could be supported directly on the reconditioned subgrade
soils and suitable fill soils placed and compacted as outlined in that section.
The pavement subgrades are expected to consist of lean clay. The lean clay would be
subject to low remolded shear strength. A resistance value (R-value) of 5 was estimated
for the subgrade soils and used in the pavement section design. Traffic loading on the
site pavements is expected to consist of areas of low volumes of automobiles and light
trucks, as well as areas of higher light-vehicle traffic volumes and heavier trash and
delivery trucks. Equivalent 18-kip single axle loads (ESAL’s) were estimated for the
quantity of site traffic anticipated. Two (2) general pavement design classifications are
outlined below in Table I. Standard duty pavements could be considered in automobile
drive and parking areas. Heavy duty pavements should be considered for access drives
and other areas of the site expected to receive higher traffic volumes or heavy truck
traffic. It has been our experience that full-depth asphaltic concrete pavement sections
typically do not perform as well as structurally equivalent composite sections over time.
With the lean clay subgrade soils anticipated in proposed drive and parking areas, we do
not recommend full-depth asphaltic concrete pavement sections be considered for this
project.
Proofrolling of the pavement subgrades should be completed to help identify unstable
areas. Depending on the in place moisture content of the subgrade soils immediately
prior to paving, the time of year when construction occurs and other hydrologic
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
10
conditions, stabilization of the subgrade soils may become necessary to develop a
suitable paving platform. If required, we recommend consideration be given to
stabilization of the pavement subgrades with Class C fly ash. With the increase in
support strength developed by the fly ash stabilization procedures, it is our opinion some
credit for the stabilized zone could be included in the pavement section design, reducing
the required thickness of overlying asphaltic concrete and aggregate base course.
Pavement section design options incorporating some structural credit for the stabilized
subgrade soils are outlined below in Table 1. Fly ash stabilization can also eliminate
some of the uncertainty associated with attempting to pave during periods of inclement
weather.
TABLE 1 – PAVEMENT SECTION DESIGN
Standard Duty Heavy Duty
Option A – Composite
Asphaltic Concrete (Grading S or SX)
Aggregate Base (Class 5 or 6)
4”
6”
5”
8”
Option B – Composite on Stabilized Subgrade
Asphaltic Concrete (Grading S or SX)
Aggregate Base (Class 5 or 6)
Fly Ash Stabilized Subgrade
3”
4”
12”
4”
6”
12”
Option C - Portland Cement Concrete Pavement
PCCP
5”
6”
Asphaltic concrete should consist of a bituminous plant mix composed of a mixture of
aggregate, filler, binders and additives if required meeting the design requirements of the
City of Fort Collins. Aggregate used in the asphaltic concrete should meet specific
gradation requirements such as Colorado Department of Transportation (CDOT) grading
S (¾-inch minus) or SX (½-inch minus) specifications. Hot mix asphalt designed using
“Superpave” criteria should be compacted to within 92 to 96% of the materials Maximum
Theoretical Density. Aggregate base should be consistent with CDOT requirements for
Class 5 or Class 6 aggregate base, placed in loose lifts not to exceed 9 inches thick and
compacted to at least 95% of the materials standard Proctor maximum dry density.
If fly ash stabilization procedures will be completed, we recommend the addition of 13%
class ‘C’ fly ash based on component dry unit weights. A 12-inch thick stabilized zone
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
11
should be constructed by thoroughly blending the fly ash with the in-place subgrade soils.
Some “fluffing” of the finish subgrade level should be expected with the stabilization
procedures. The blended materials should be adjusted in moisture content to within the
range of ±2% of standard Proctor optimum moisture content and compacted to at least
95% of the material’s standard Proctor maximum dry density within two (2) hours of fly
ash addition.
For areas subjected to truck turning movements and/or concentrated and repetitive
loading such as dumpster or truck parking and loading areas, we recommend
consideration be given to the use of Portland cement concrete pavement with a minimum
thickness of 6 inches. The concrete used for site pavements should be air entrained and
have a minimum 28-day compressive strength of 4,200 psi. Woven wire mesh or fiber
entrained concrete should be considered to help in the control of shrinkage cracking.
The proposed pavement section designs do not include an allowance for excessive
loading conditions imposed by heavy construction vehicles or equipment. Heavily
loaded concrete or other building material trucks and construction equipment can cause
some localized distress to site pavements. The recommended pavement sections are
minimums and periodic maintenance efforts should be expected. A preventative
maintenance program can help increase the service life of site pavements.
Corrosive Soil Characteristics
We measured the soluble sulfate concentration of two (2) representative samples of the
subsoils which will likely be in contact with structural concrete. The sulfate
concentrations measured in the samples fall within the range of 0 to 150 parts per million.
ACI rates the measured concentrations as being a negligible risk of concrete sulfate
attack; therefore Type I cement should be suitable for concrete members on and below
grade. As an added precaution, Type I/II Portland cement could be considered for
additional sulfate resistance of construction concrete. Foundation concrete should be
designed in accordance with the provisions of the ACI Design Manual, Section 318,
Chapter 4.
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
12
Drainage
Positive drainage is imperative for satisfactory long-term performance of the proposed
building and associated site improvements. We recommend positive drainage be
developed away from the structure during construction and maintained throughout the
life of the site improvements, with twelve (12) inches of fall in the first 10 feet away from
the building. Shallower slopes could be considered in hardscape areas. In the event that
negative drainage develops back toward the building over time due to soil movement, the
original grade and associated positive drainage outlined above should be immediately
restored.
Care should be taken in the planning of landscaping to avoid features which could result
in the fluctuation of the moisture content of the foundation bearing and flatwork and
pavement subgrade soils. We recommend watering systems be placed a minimum of 5
feet away from the perimeters of the site structures and be designed to discharge away
from all site improvements. Gutter systems should be considered to help reduce the
potential for water ponding adjacent to the structures with the gutter downspouts, roof
drains or scuppers extended to discharge a minimum of 5 feet away from structural,
flatwork and pavement elements. Water which is allowed to pond adjacent to site
improvements can result in unsatisfactory performance of those improvements over time.
LIMITATIONS
This report was prepared based upon the data obtained from the completed site
exploration, laboratory testing, engineering analysis and any other information discussed.
The completed borings provide an indication of subsurface conditions at the boring
locations only. Variations in subsurface conditions can occur in relatively short distances
away from the borings. This report does not reflect any variations which may occur
across the site or away from the borings. If variations in the subsurface conditions
anticipated become evident, the geotechnical engineer should be notified immediately so
that further evaluation and supplemental recommendations can be provided.
Geotechnical Subsurface Exploration Report
Bee Be Christian School
A Portion of Outlot A, Spring Creek Farms North
Fort Collins, Colorado
Soilogic # 16-1131
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The scope of services for this project does not include either specifically or by
implication any biological or environmental assessment of the site or identification or
prevention of pollutants or hazardous materials or conditions. Other studies should be
completed if concerns over the potential of such contamination or pollution exist.
The geotechnical engineer should be retained to review the plans and specifications so
that comments can be made regarding the interpretation and implementation of our
geotechnical recommendations in the design and specifications. The geotechnical
engineer should also be retained to provide testing and observation services during
construction to help determine that the design requirements are fulfilled.
This report has been prepared for the exclusive use of our client for specific application
to the project discussed and has been prepared in accordance with the generally accepted
standard of care for the profession. No warranties express or implied, are made. The
conclusions and recommendations contained in this report should not be considered valid
in the event that any changes in the nature, design or location of the project as outlined in
this report are planned, unless those changes are reviewed and the conclusions of this
report modified and verified in writing by the geotechnical engineer.
LOG OF BORING B-1
1/1 CME 45
4" CFA
Automatic
BMc
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu
% Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
6" VEGETATION & TOPSOIL -
1
-
2
CL SILTY LEAN CLAY WITH SAND -
light brown to reddish brown/rust 3 CS 20 10.2 114.0 9000+ 3.9% 5500 - - -
stiff to very stiff -
4
-
5 CS 15 9.2 84.4 9000+ 0.8% 1100 31 9 85.0%
-
6
-
7
-
8
-
9
-
10 CS 22 7.5 - N/A - - - - -
-
11
-
12
-
13
-
14
-
15 CS 13 15.9 107.6 9000+ - - - - -
BOTTOM OF BORING 15' -
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
-
LOG OF BORING B-2
1/1 CME 45
4" CFA
Automatic
BMc
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu
% Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
6" VEGETATION & TOPSOIL -
1
-
2
CL SILTY/SANDY LEAN CLAY -
light brown to reddish brown/rust 3
stiff to very stiff -
4
-
5 CS 15 9.3 92.1 9000+ 0.9% 1250 - - -
-
6
-
7
-
8
-
9
-
10 CS 24 8.5 111.1 9000+ None <500 - - -
-
11
-
12
-
13
-
14
-
15 CS 17 12.1 116.6 9000+ - - - - -
BOTTOM OF BORING 15' -
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
-
LOG OF BORING B-3
1/1 CME 45
4" CFA
Automatic
BMc
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu
% Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
5" VEGETATION & TOPSOIL -
1
-
2
CL SILTY/SANDY LEAN CLAY -
light brown to reddish brown/rust 3 CS 17 7.1 98.3 9000+ None <500 - - -
stiff to very stiff -
4
-
5 CS 12 6.8 - 9000+ - - - - -
-
6
-
7
-
8
-
9
-
10 CS 24 6.5 - N/A - - - - -
-
11
-
12
-
13
-
14
-
15 CS 15 13.6 110.8 9000+ - - - - -
BOTTOM OF BORING 15' -
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
-
LOG OF BORING B-4
1/1 CME 45
4" CFA
Automatic
BMc
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu
% Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
6" VEGETATION & TOPSOIL -
1
-
2
CL SILTY/SANDY LEAN CLAY -
light brown to reddish brown/rust 3
medium stiff to stiff -
4
-
5 CS 16 8.3 102.0 9000+ 1.3% 1250 - - -
-
6
-
7
-
8
Increasing Sand Content 8 to 12' -
9
-
10 CS 14 13.6 110.8 9000+ - - - - -
-
11
-
12
-
13
-
14
-
15 CS 8 10.1 - N/A - - - - -
BOTTOM OF BORING 15' -
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
-
LOG OF BORING B-5
1/1 CME 45
4" CFA
Automatic
BMc
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu
% Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
5" VEGETATION & TOPSOIL -
1
-
2
CL SILTY/SANDY LEAN CLAY -
light brown to reddish brown/rust 3 CS 12 10.6 110.4 9000+ 0.9% - 36 16 59.4%
stiff -
4
-
5 CS 16 8.2 92.3 9000+ 0.1% 600 - - -
-
6
-
7
-
8
-
9
-
10 CS 17 2.3 110.4 9000+ - - - - -
-
11
-
12
-
13
-
14
-
15 CS 12 9.0 121.3 9000+ - - - - -
BOTTOM OF BORING 15' -
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
-
LOG OF BORING B-6
1/1 CME 45
4" CFA
Automatic
BMc
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu
% Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
6" VEGETATION & TOPSOIL -
1
-
2
CL SILTY/SANDY LEAN CLAY -
light brown to reddish brown/rust 3 CS 13 8.0 95.3 9000+ 0.5% 1100 - - -
stiff to very stiff -
4
-
5 CS 18 7.5 111.2 9000+ None <500 - - -
-
6
-
7
-
8
Increasing Sand Content @ 8.5' -
9
-
10 CS 19 2.4 - N/A - - - - -
BOTTOM OF BORING 10' -
11
-
12
-
13
-
14
-
15
-
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
-
LOG OF BORING B-7
1/1 CME 45
4" CFA
Automatic
BMc
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu
% Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
4" VEGETATION & TOPSOIL -
1
-
2
CL SILTY/SANDY LEAN CLAY -
light brown to reddish brown/rust 3 CS 14 6.3 104.5 9000+ 0.3% 1000 - - -
stiff -
4
-
5 CS 17 6.5 104.0 9000+ 0.9% 1500 - - -
-
6
-
7
-
8
-
9
-
10 CS 14 4.9 112.0 9000+ - - - - -
BOTTOM OF BORING 10' -
11
-
12
-
13
-
14
-
15
-
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
-
LOG OF BORING B-8
1/1 CME 45
4" CFA
Automatic
BMc
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu
% Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
3" VEGETATION & TOPSOIL -
1
-
2
CL SILTY LEAN CLAY WITH SAND -
light brown to reddish brown/rust 3 CS 15 10.2 113.8 9000+ 0.3% 450 - - -
stiff to very stiff -
4
-
5 CS 15 8.3 95.0 9000+ - - 30 12 85.7%
-
6
-
7
-
8
-
9
-
10 CS 23 9.6 - N/A - - - - -
BOTTOM OF BORING 10' -
11
-
12
-
13
-
14
-
15
-
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
-
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 114.0 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-1 @ 2'
Sample Description: Light Brown to Reddish Brown/Rust Lean Clay with Sand
Initial Moisture 10.2%
Final Moisture 16.5%
% Swell @ 500 psf 3.9%
Swell Pressure 5,500 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit 31
Plasticity Index 9
% Passing #200 85.0%
Dry Density 84.4 pcf
0.8%
1,100 psf
Initial Moisture
Final Moisture
% Swell @ 500 psf
Swell Pressure
9.2%
30.7%
Sample Description: Light Brown to Reddish Brown/Rust Lean Clay with Sand
Sample ID: B-1 @ 4'
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 92.1 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-2 @ 4'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 9.3%
Final Moisture 28.3%
% Swell @ 500 psf 0.9%
Swell Pressure 1,250 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 111.1 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-2 @ 9'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 8.5%
Final Moisture 18.6%
% Swell @ 500 psf None
Swell Pressure <500 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 98.3 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-3 @ 2'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 7.1%
Final Moisture 21.4%
% Swell @ 500 psf None
Swell Pressure <500 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 102.0 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-4 @ 4'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 8.3%
Final Moisture 26.7%
% Swell @ 500 psf 1.3%
Swell Pressure 1250 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit 36
Plasticity Index 16
% Passing #200 59.4%
Dry Density 110.4 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-5 @ 2'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 10.6%
Final Moisture 22.6%
% Swell @ 500 psf 0.9%
Swell Pressure -
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 92.3 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-5 @ 4'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 8.2%
Final Moisture 29.2%
% Swell @ 500 psf 0.1%
Swell Pressure 600 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 95.3 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-6 @ 2'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 8.0%
Final Moisture 26.7%
% Swell @ 500 psf 0.5%
Swell Pressure 1,100 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 111.2 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-6 @ 4'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 7.5%
Final Moisture 20.6%
% Swell @ 500 psf None
Swell Pressure <500 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 104.5 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-7 @ 2'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 6.3%
Final Moisture 27.4%
% Swell @ 200 psf 0.3%
Swell Pressure 1,000 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 104.0 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-7 @ 4'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 6.5%
Final Moisture 25.8%
% Swell @ 500 psf 0.9%
Swell Pressure 1,500 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density 113.8 pcf
BEE BE CHRISTIAN SCHOOL - A PORTION OF OUTLOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
SWELL/CONSOLIDATION TEST SUMMARY
Sample ID: B-8 @ 2'
Sample Description: Light Brown to Reddish Brown/Rust Sandy Lean Clay
Initial Moisture 10.2%
Final Moisture 15.9%
% Swell @ 200 psf 0.3%
Swell Pressure 450 psf
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
UNIFIED SOIL CLASSIFICATION SYSTEM
Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Soil Classification
Group
Symbol
Group NameB
Clean Gravels Cu ! 4 and 1 " Cc " 3E GW Well graded gravelF
Less than 5% finesC Cu
< 4 and/or 1 > Cc > 3E GP Poorly graded gravelF
Fines classify as ML or MH GM Silty gravelF,G, H
Coarse Grained Soils
More than 50% retained
on No. 200 sieve
Gravels
More than 50% of coarse
fraction retained on
No. 4 sieve Gravels with Fines More
than 12% finesC Fines classify as CL or CH GC Clayey gravelF,G,H
Clean Sands Cu ! 6 and 1 " Cc " 3E SW Well graded sandI
Less than 5% finesD Cu
< 6 and/or 1 > Cc > 3E SP Poorly graded sandI
Fines classify as ML or MH SM Silty sandG,H,I
Sands
50% or more of coarse
fraction passes
No. 4 sieve Sands with Fines
More than 12% finesD Fines classify as CL or CH SC Clayey sandG,H,I
Silts and Clays PI > 7 and plots on or above “A” lineJ CL Lean clayK,L,M
Liquid limit less than 50
Inorganic
PI < 4 or plots below “A” lineJ ML SiltK,L,M
Liquid limit - oven
dried
Organic clayK,L,M,N
Fine-Grained Soils
50% or more passes the
No. 200 sieve
Organic
Liquid limit - not
dried
< 0.75 OL
Organic siltK,L,M,O
Inorganic PI plots on or above “A” line CH Fat clayK,L,M
Silts and Clays
Liquid limit 50 or more
PI plots below “A” line MH Elastic siltK,L,M
Organic Liquid limit - oven dried Organic clayK,L,M,P
Liquid limit - not dried
< 0.75 OH
Organic siltK,L,M,Q
Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat
A Based on the material passing the 3-in. (75-mm) sieve
B If field sample contained cobbles or boulders, or both, add “with cobbles
or boulders, or both” to group name.
C Gravels with 5 to 12% fines require dual symbols: GW-GM well graded
gravel with silt, GW-GC well graded gravel with clay, GP-GM poorly
graded gravel with silt, GP-GC poorly graded gravel with clay.
D Sands with 5 to 12% fines require dual symbols: SW-SM well graded
sand with silt, SW-SC well graded sand with clay, SP-SM poorly graded
sand with silt, SP-SC poorly graded sand with clay
E Cu = D60/D10 Cc =
GENERAL NOTES
DRILLING & SAMPLING SYMBOLS:
SS: Split Spoon - 1⅜" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger
ST: Thin-Walled Tube – 2.5" O.D., unless otherwise noted PA: Power Auger
RS: Ring Sampler - 2.42" I.D., 3" O.D., unless otherwise noted HA: Hand Auger
CS: California Barrel - 1.92" I.D., 2.5" O.D., unless otherwise noted RB: Rock Bit
BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary
The number of blows required to advance a standard 2-inch O.D. split-spoon sampler (SS) the last 12 inches of the total 18-inch
penetration with a 140-pound hammer falling 30 inches is considered the “Standard Penetration” or “N-value”. For 2.5” O.D.
California Barrel samplers (CB) the penetration value is reported as the number of blows required to advance the sampler 12
inches using a 140-pound hammer falling 30 inches, reported as “blows per inch,” and is not considered equivalent to the
“Standard Penetration” or “N-value”.
WATER LEVEL MEASUREMENT SYMBOLS:
WL: Water Level WS: While Sampling
WCI: Wet Cave in WD: While Drilling
DCI: Dry Cave in BCR: Before Casing Removal
AB: After Boring ACR: After Casing Removal
Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other
times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater.
In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-term observations.
DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils
have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand.
Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they
are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents
may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined
on the basis of their in-place relative density and fine-grained soils on the basis of their consistency.
FINE-GRAINED SOILS COARSE-GRAINED SOILS BEDROCK
(CB)
Blows/Ft.
(SS)
Blows/Ft.
Consistency
(CB)
Blows/Ft.
(SS)
Blows/Ft.
Relative
Density
(CB)
Blows/Ft.
(SS)
Blows/Ft.
Consistency
< 3 0-2 Very Soft 0-5 < 3 Very Loose < 24 < 20 Weathered
3-5 3-4 Soft 6-14 4-9 Loose 24-35 20-29 Firm
6-10 5-8 Medium Stiff 15-46 10-29 Medium Dense 36-60 30-49 Medium Hard
11-18 9-15 Stiff 47-79 30-50 Dense 61-96 50-79 Hard
19-36 16-30 Very Stiff > 79 > 50 Very Dense > 96 > 79 Very Hard
> 36 > 30 Hard
RELATIVE PROPORTIONS OF SAND AND
GRAVEL
GRAIN SIZE TERMINOLOGY
Descriptive Terms of
Other Constituents
Percent of
Dry Weight
Major Component
of Sample
Particle Size
Trace < 15 Boulders Over 12 in. (300mm)
With 15 – 29 Cobbles 12 in. to 3 in. (300mm to 75 mm)
Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75 mm)
Sand
Silt or Clay
#4 to #200 sieve (4.75mm to 0.075mm)
Passing #200 Sieve (0.075mm)
RELATIVE PROPORTIONS OF FINES PLASTICITY DESCRIPTION
Descriptive Terms of
Other Constituents
Percent of
Dry Weight
Term Plasticity Index
Trace
With
Modifiers
< 5
5 – 12
> 12
Non-plastic
Low
Medium
High
0
1-10
11-30
30+
F If soil contains ! 15% sand, add “with sand” to group name.
G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.
HIf fines are organic, add “with organic fines” to group name.
I If soil contains ! 15% gravel, add “with gravel” to group name.
J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.
K If soil contains 15 to 29% plus No. 200, add “with sand” or “with
gravel,” whichever is predominant.
L If soil contains ! 30% plus No. 200 predominantly sand, add
“sandy” to group name.
M If soil contains ! 30% plus No. 200, predominantly gravel, add
“gravelly” to group name.
N PI ! 4 and plots on or above “A” line.
O PI < 4 or plots below “A” line.
P PI plots on or above “A” line.
Q PI plots below “A” line.
26
-
27
-
28
-
29
-
30
Surface Elev. - Field Personnel: 24 Hours After Drilling -
USCS
Sampler
Atterberg Limits
Start Date 5/31/2016 Auger Type: During Drilling None
Finish Date 5/31/2016 Hammer Type: After Drilling None
BEE BE CHRISTIAN SCHOOL - A PORTION OF LOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
Sheet Drilling Rig: Water Depth Information
26
-
27
-
28
-
29
-
30
BEE BE CHRISTIAN SCHOOL - A PORTION OF LOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
Sheet Drilling Rig: Water Depth Information
Start Date 5/31/2016 Auger Type: During Drilling None
Finish Date 5/31/2016 Hammer Type: After Drilling None
Surface Elev. - Field Personnel: 24 Hours After Drilling -
USCS
Sampler
Atterberg Limits
26
-
27
-
28
-
29
-
30
BEE BE CHRISTIAN SCHOOL - A PORTION OF LOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
Sheet Drilling Rig: Water Depth Information
Start Date 5/31/2016 Auger Type: During Drilling None
Finish Date 5/31/2016 Hammer Type: After Drilling None
Surface Elev. - Field Personnel: 24 Hours After Drilling -
USCS
Sampler
Atterberg Limits
26
-
27
-
28
-
29
-
30
Surface Elev. - Field Personnel: 24 Hours After Drilling -
USCS
Sampler
Atterberg Limits
Start Date 5/31/2016 Auger Type: During Drilling None
Finish Date 5/31/2016 Hammer Type: After Drilling None
BEE BE CHRISTIAN SCHOOL - A PORTION OF LOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
Sheet Drilling Rig: Water Depth Information
26
-
27
-
28
-
29
-
30
Surface Elev. - Field Personnel: 24 Hours After Drilling -
USCS
Sampler
Atterberg Limits
Start Date 5/31/2016 Auger Type: During Drilling None
Finish Date 5/31/2016 Hammer Type: After Drilling None
BEE BE CHRISTIAN SCHOOL - A PORTION OF LOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
Sheet Drilling Rig: Water Depth Information
26
-
27
-
28
-
29
-
30
Surface Elev. - Field Personnel: 24 Hours After Drilling -
USCS
Sampler
Atterberg Limits
Start Date 5/31/2016 Auger Type: During Drilling None
Finish Date 5/31/2016 Hammer Type: After Drilling None
BEE BE CHRISTIAN SCHOOL - A PORTION OF LOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
Sheet Drilling Rig: Water Depth Information
26
-
27
-
28
-
29
-
30
Surface Elev. - Field Personnel: 24 Hours After Drilling -
USCS
Sampler
Atterberg Limits
Start Date 5/31/2016 Auger Type: During Drilling None
Finish Date 5/31/2016 Hammer Type: After Drilling None
BEE BE CHRISTIAN SCHOOL - A PORTION OF LOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
Sheet Drilling Rig: Water Depth Information
26
-
27
-
28
-
29
-
30
Surface Elev. - Field Personnel: 24 Hours After Drilling -
USCS
Sampler
Atterberg Limits
Start Date 5/31/2016 Auger Type: During Drilling None
Finish Date 5/31/2016 Hammer Type: After Drilling None
BEE BE CHRISTIAN SCHOOL - A PORTION OF LOT A, SPRING CREEK FARMS NORTH
FORT COLLINS, COLORADO
Project # 16-1131
June 2016
Sheet Drilling Rig: Water Depth Information