HomeMy WebLinkAboutWALNUT-CHESTNUT SUBDIVISION SECOND - Filed GR-GEOTECHNICAL REPORT/SOILS REPORT - 2017-12-13TABLE OF CONTENTS
EXECUTIVE SUMMARY ............................................................................................................ i
1.0 INTRODUCTION .............................................................................................................1
2.0 PROJECT INFORMATION .............................................................................................1
2.1 Project Description ...............................................................................................1
2.2 Site Location and Description...............................................................................2
3.0 SUBSURFACE CONDITIONS ........................................................................................2
3.1 Typical Subsurface Profile ...................................................................................2
3.2 Laboratory Testing ...............................................................................................3
3.3 Corrosion Protection (Water-Soluble Sulfates) .....................................................3
3.4 Groundwater ........................................................................................................3
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION ......................................3
4.1 Geotechnical Considerations ...............................................................................3
4.1.1 Existing, Undocumented Fill .....................................................................4
4.2 Earthwork.............................................................................................................4
4.2.1 Site Preparation ........................................................................................4
4.2.2 Excavation ................................................................................................4
4.2.3 Subgrade Preparation ...............................................................................5
4.2.4 Fill Materials and Placement ......................................................................5
4.2.5 Compaction Requirements ........................................................................6
4.2.6 Grading and Drainage ...............................................................................7
4.3 Pavements ...........................................................................................................7
4.3.1 Pavements Subgrade Preparation .........................................................7
4.3.2 Pavements Design Recommendations ..................................................8
4.3.3 Pavements Construction Considerations .............................................10
4.3.4 Pavements Maintenance .....................................................................10
5.0 GENERAL COMMENTS ...............................................................................................10
Appendix A FIELD EXPLORATION
Exhibit A-1 Site Location Map
Exhibit A-2 Exploration Plan
Exhibit A-3 Field Exploration Description
Exhibits A-4 to A-6 Boring Logs
Appendix B LABORATORY TESTING
Exhibit B-1 Laboratory Testing Description
Exhibit B-2 Atterberg Limits Test Results
Exhibit B-3 Grain-size Distribution Test Results
Exhibits B-4 & B-5 Swell-consolidation Test Results
Exhibit B-6 R-value Test Results
Appendix C SUPPORTING DOCUMENTS
Exhibit C-1 General Notes
Exhibit C-2 Unified Soil Classification System
TABLE OF CONTENTS (continued)
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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EXECUTIVE SUMMARY
A geotechnical exploration has been performed for the proposed city-maintained roadways to be
constructed at the Front Range Colorado Hospitality project that is currently under construction at
354 Walnut Street in Fort Collins, Colorado. Three (3) borings, presented as Exhibits A-4 through
A-6 and designated as Boring No. 1 through Boring No. 3, were performed to depths of approximately
10½ feet below existing site grades. This report specifically addresses the recommendations for the
proposed city maintained roadways. Borings performed in these areas are for informational
purposes and will be utilized by others.
Based on the information obtained from our subsurface exploration, the site can be developed for
the proposed project. However, the following geotechnical considerations were identified and will
need to be considered:
Subsurface conditions generally consisted of about 2½ to 3 feet of fill containing clayey sand
to sandy lean clay with gravel over silty clayey gravel with sand which extended to the
maximum depths of exploration in the majority of the borings performed on the site.
Existing, undocumented fill was encountered in the borings performed on this site to depths
ranging from about 2½ to 3 feet below existing site grades. Careful consideration should be
taken for pavements constructed on the existing undocumented fill. We recommend
thoroughly proof rolling the exposed subgrade soils prior to constructing the new roadways
to identify any soft or loose areas that need to be repaired.
The amount of movement of the pavements will be related to the wetting of underlying
supporting soils. Therefore, it is imperative the recommendations discussed in the 4.2.6
Grading and Drainage section of this report be followed to reduce potential movement.
Close monitoring of the construction operations discussed herein will be critical in achieving
the design subgrade support. We therefore recommend that Terracon be retained to
monitor this portion of the work.
This summary should be used in conjunction with the entire report for design purposes. It should
be recognized that details were not included or fully developed in this section, and the report must
be read in its entirety for a comprehensive understanding of the items contained herein. The section
titled GENERAL COMMENTS should be read for an understanding of the report limitations.
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GEOTECHNICAL ENGINEERING REPORT
Front Range Colorado Hospitality Project City Roadways
354 Walnut Street
Fort Collins, Colorado
Terracon Project No. 20145072
July 21, 2017
1.0 INTRODUCTION
This report presents the results of our geotechnical engineering services performed for the
proposed city-maintained roadways to be constructed at the Front Range Colorado Hospitality
project that is currently under construction at 354 Walnut Street in Fort Collins, Colorado (Exhibit
A-1). The purpose of these services is to provide information and geotechnical engineering
recommendations relative to:
subsurface soil conditions seismic considerations
groundwater conditions pavement construction
grading and drainage earthwork
Our geotechnical engineering scope of work for this project included the initial site visit, the
advancement of three test borings to depths ranging from approximately 10½ feet below existing
site grades, laboratory testing for soil engineering properties and engineering analyses to provide
pavement design and construction recommendations.
Logs of the borings along with an Exploration Plan (Exhibit A-2) are included in Appendix A. The
results of the laboratory testing performed on soil samples obtained from the site during the field
exploration are included in Appendix B.
Previously, Terracon performed a geotechnical study at the project site, as presented in Report No.
20145072 dated January 20, 2015. Information from the previous study was used in the evaluation
of the current project.
2.0 PROJECT INFORMATION
2.1 Project Description
Item Description
Site layout Refer to the Exploration Plan (Exhibit A-2 in Appendix A)
Proposed construction
Plans indicate the proposed construction includes new pavements
associated with roadway widening and realignment for the area
south of the Front Range Hospitality Project.
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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Item Description
Cut and fills slopes Assumed to be no steeper than 3H:1V (Horizontal to Vertical)
Traffic loading
The following traffic values were provided to us by the City of Fort
Collins Engineering Department for our use in developing
recommended pavement thicknesses:
EDLA: 7.5
ESALS: 54,750
2.2 Site Location and Description
Item Description
Location The project site is located at 354 Walnut Street in Fort Collins,
Colorado.
Existing site features
The Front Range Colorado Hospitality Project and Parking Garage
are currently under construction. The site is surrounded by existing
commercial developments.
Current ground cover The current ground cover consists of gravel surface and existing
asphalt.
Existing topography The site is relatively flat.
3.1 Typical Subsurface Profile
Specific conditions encountered at each boring location are indicated on the individual boring logs
included in Appendix A. Stratification boundaries on the boring logs represent the approximate
location of changes in soil types; in-situ, the transition between materials may be gradual. Based
on the results of the borings, subsurface conditions on the project site can be generalized as
follows:
Material Description Approximate Depth to
Bottom of Stratum Consistency/Density
Asphalt surface
About 4 to 5 inches below
existing site grades. Only
encountered in Boring Nos. 1
and 2.
--
Aggregate Base course
About 8 inches below existing
site grades, only encountered in
Boring Nos. 1 and 2.
--
Fill materials consisting of sandy
lean clay to clayey sand materials
About 2½ to 3 feet below
existing site grades. --
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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Material Description Approximate Depth to
Bottom of Stratum Consistency/Density
Silty clayey gravel with sand
About 8 feet to the maximum
depth of exploration of about 10
feet below existing site grades.
Very dense
Silty sand
Only encountered in Boring No.
1, to the maximum depth of
exploration of about 10 feet.
Very dense
3.2 Laboratory Testing
Representative soil samples were selected for swell-consolidation testing and exhibited 0.6 to 1.5
percent compression when wetted. Samples of site soils selected for plasticity testing exhibited
low to moderate plasticity with liquid limits ranging from non-plastic to 36 and plasticity indices
ranging from non-plastic to 18. Laboratory test results are presented in Appendix B.
3.3 Corrosion Protection (Water-Soluble Sulfates)
At the time this report was prepared, the laboratory testing for water-soluble sulfates had not been
completed. We will submit a supplemental letter with the testing results and recommendations
once the testing has been completed.
3.4 Groundwater
The boreholes were observed while drilling and after completion for the presence and level of
groundwater. Groundwater was not observed in the borings while drilling, or for the short duration
that the borings were allowed to remain open.
Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff
and other factors not evident at the time the borings were performed. Therefore, groundwater
levels during construction or at other times in the life of the structure may be higher or lower than
the levels indicated on the boring logs. The possibility of groundwater level fluctuations should
be considered when developing the design and construction plans for the project. However, we
do not believe that groundwater will significantly impact the proposed construction.
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION
4.1 Geotechnical Considerations
Based on subsurface conditions encountered in the borings, the site appears suitable for the
proposed construction from a geotechnical point of view provided certain precautions and design
and construction recommendations described in this report are followed. We have identified
geotechnical conditions that could impact design and construction of the proposed pavements.
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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4.1.1 Existing, Undocumented Fill
As previously noted, existing undocumented fill was encountered to depths up to about 3 feet in
the borings drilled at the site. We do not possess any information regarding whether the fill was
placed under the observation of a geotechnical engineer.
Support of pavements on or above existing fill soils is discussed in this report. There is an inherent
risk for the owner that compressible fill or unsuitable material within or buried by the fill will not be
discovered. This risk of unforeseen conditions cannot be eliminated without completely removing
the existing fill, but can be reduced by performing additional testing and evaluation. However, we
believe the risk can be significantly reduced by thoroughly proof rolling the exposed ground prior
to constructing the new roadways to assist with identifying any loose or soft areas that need to be
repaired.
4.2 Earthwork
The following presents recommendations for site preparation, excavation, subgrade preparation
and placement of engineered fills on the project. All earthwork on the project should be observed
and evaluated by Terracon on a full-time basis. The evaluation of earthwork should include
observation of over-excavation operations, testing of engineered fills, subgrade preparation,
subgrade stabilization, and other geotechnical conditions exposed during the construction of the
project.
4.2.1 Site Preparation
Prior to placing any fill, strip and remove existing surface material, and any other deleterious
materials from the proposed construction areas.
Stripped organic materials should be wasted from the site or used to re-vegetate landscaped areas
or exposed slopes after completion of grading operations. Prior to the placement of fills, the site
should be graded to create a relatively level surface to receive fill.
Demolition of the existing pavements should include complete removal of all components within the
proposed construction area. This should include removal of any utilities to be abandoned along
with any loose utility trench backfill or loose backfill found adjacent to existing foundations. All
materials derived from the demolition of existing pavements should be removed from the site, and
not be allowed for use in any on-site fills.
4.2.2 Excavation
It is anticipated that excavations for the proposed construction can be accomplished with
conventional earthmoving equipment.
The soils to be excavated can vary significantly across the site as their classifications are based
solely on the materials encountered in widely-spaced exploratory test borings. The contractor
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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should verify that similar conditions exist throughout the proposed area of excavation. If different
subsurface conditions are encountered at the time of construction, the actual conditions should be
evaluated to determine any excavation modifications necessary to maintain safe conditions.
If underground facilities are encountered, such features should be removed and the excavation
thoroughly cleaned prior to backfill placement and/or construction.
Depending upon depth of excavation and seasonal conditions, surface water infiltration and/or
groundwater may be encountered in excavations on the site. It is anticipated that pumping from
sumps may be utilized to control water within excavations.
The subgrade soil conditions should be evaluated during the excavation process and the stability
of the soils determined at that time by the Competent Person. Slope inclinations flatter
than the OSHA maximum values may have to be used. The individual contractor(s) should be
made responsible for designing and constructing stable, temporary excavations as required to
maintain stability of both the excavation sides and bottom. All excavations should be sloped or
shored in the interest of safety following local, and federal regulations, including current OSHA
excavation and trench safety standards.
As a safety measure, it is recommended that all vehicles and soil piles be kept a minimum lateral
distance from the crest of the slope equal to the slope height. The exposed slope face should be
protected against the elements
4.2.3 Subgrade Preparation
After the existing roadway materials have been removed from the construction area, the top 8
inches of the exposed ground surface should be scarified, moisture conditioned, and recompacted
to at least 95 percent of the maximum dry unit weight as determined by ASTM D698 before any
new fill or pavement is placed.
After the bottom of the excavation has been compacted, engineered fill can be placed to bring the
pavement subgrade to the desired grade. Engineered fill should be placed in accordance with
the recommendations presented in subsequent sections of this report.
The stability of the subgrade may be affected by precipitation, repetitive construction traffic or
other factors. If unstable conditions develop, workability may be improved by scarifying and
drying. Alternatively, over-excavation of wet zones and replacement with granular materials may
be used, or crushed gravel and/or rock can be tracked or crowd into the unstable surface soil
until a stable working surface is attained. Lightweight excavation equipment may also be used to
reduce subgrade pumping.
4.2.4 Fill Materials and Placement
The on-site soils or approved granular and low plasticity cohesive imported materials may be used
as fill material. The soil removed from this site that is free of organic or objectionable materials,
as defined by a field technician who is qualified in soil material identification and compaction
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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procedures, can be re-used as fill for the pavement subgrade. It should be noted that existing fill
will require reworking to adjust the moisture content to meet the compaction criteria.
Imported soils (if required) should meet the following material property requirements:
Gradation Percent finer by weight (ASTM C136)
100
70-100
No. 4 Sieve 50-100
No. 200 Sieve 50 (max.)
Soil Properties Values
Liquid Limit 35 (max.)
Plastic Limit 6 (max.)
Maximum Expansive Potential (%) Non-expansive1
1. Measured on a sample compacted to approximately 95 percent of the maximum dry unit weight as
determined by ASTM D698 at optimum moisture content. The sample is confined under a 100 psf
surcharge and submerged.
4.2.5 Compaction Requirements
Engineered fill should be placed and compacted in horizontal lifts, using equipment and
procedures that will produce recommended moisture contents and densities throughout the lift.
Item Description
Fill lift thickness
9 inches or less in loose thickness when heavy, self-
propelled compaction equipment is used
4 to 6 inches in loose thickness when hand-guided
equipment (i.e. jumping jack or plate compactor) is used
Minimum compaction requirements 95 percent of the maximum dry unit weight as determined
by ASTM D 698.
Moisture content cohesive soil (clay) -1 to +3 % of the optimum moisture content
Moisture content cohesionless soil
(sand) -3 to +3 % of the optimum moisture content
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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Item Description
1. We recommend engineered fill be tested for moisture content and compaction during placement.
Should the results of the in-place density tests indicate the specified moisture or compaction limits
have not been met, the area represented by the test should be reworked and retested as required
until the specified moisture and compaction requirements are achieved.
2. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction to
be achieved without the fill material pumping when proofrolled.
3. Moisture conditioned clay materials should not be allowed to dry out. A loss of moisture within these
materials could result in an increase in the material s expansive potential. Subsequent wetting of
these materials could result in undesirable movement.
4.2.6 Grading and Drainage
All grades must be adjusted to provide effective drainage away from the proposed pavements
and existing buildings during construction and maintained throughout the life of the proposed
project. Infiltration of water into foundation excavations must be prevented during construction.
Landscape irrigation adjacent to foundations should be minimized or eliminated. Water permitted
to pond near or adjacent to the perimeter of the structures (either during or post-construction) can
result in significantly higher soil movements than those discussed in this report. As a result, any
estimations of potential movement described in this report cannot be relied upon if positive
drainage is not obtained and maintained, and water is allowed to infiltrate the fill and/or subgrade.
Exposed ground (if any) should be sloped at a minimum of 10 percent grade for at least 5 feet
beyond the perimeter of the proposed pavements and new buildings, where possible. The use of
swales, chases and/or area drains may be required to facilitate drainage in unpaved areas around
the perimeter of the buildings. Backfill against foundations and exterior walls should be properly
compacted and free of all construction debris to reduce the possibility of moisture infiltration. After
construction of the proposed pavements and prior to project completion, we recommend
verification of final grading be performed to document positive drainage, as described above, has
been achieved.
Flatwork and pavements will be subject to post-construction movement. Maximum grades
practical should be used for paving and flatwork to prevent areas where water can pond. In
addition, allowances in final grades should take into consideration post-construction movement
of flatwork, particularly if such movement would be critical. Where paving or flatwork abuts a
structures, care should be taken that joints are properly sealed and maintained to prevent the
infiltration of surface water.
4.3 Pavements
4.3.1 Pavements Subgrade Preparation
On most project sites, the site grading is accomplished relatively early in the construction phase.
Fills are typically placed and compacted in a uniform manner. However as construction proceeds,
the subgrade may be disturbed due to utility excavations, construction traffic, desiccation, or
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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rainfall/snow melt. As a result, the pavement subgrade may not be suitable for pavement
construction and corrective action will be required. The subgrade should be carefully evaluated
at the time of pavement construction for signs of disturbance or instability. We recommend the
pavement subgrade be thoroughly proofrolled with a loaded tandem-axle dump truck prior to final
grading and paving. All pavement areas should be moisture conditioned and properly compacted
to the recommendations in this report immediately prior to paving.
4.3.2 Pavements Design Recommendations
Design of pavements for the project have been based on the procedures outlined in the 1993
Guideline for Design of Pavement Structures prepared by the American Association of State
Highway and Transportation Officials (AASHTO) and the Larimer County Urban Area Street
Standards (LCUASS).
Samples of the fill materials selected for swell-consolidation testing compressed approximately 0.6
to 1.5 percent when wetted under an applied pressure of 150 psf which is less than the maximum
2 percent criteria established for determining if swell-mitigation procedures in the pavement sections
are required per LCUASS standards. Therefore, swell-mitigation of the subgrade materials prior to
pavement operations is not required.
Traffic patterns and anticipated loading conditions were provided with an 18-kip equivalent single-
axle load (ESAL) of 73,000 for automobile parking areas and an ESAL of 54,750 for the proposed
pavements. This traffic design value should be verified by the civil engineer or owner prior to final
design and construction. If the actual traffic values vary from the assumed values, the pavement
thickness recommendations may not be applicable. When the actual traffic design information is
available Terracon should be contacted so that the design recommendations can be reviewed
and revised if necessary.
For flexible pavement design, a terminal serviceability index of 2.0 was utilized along with an inherent
reliability of 85 percent and a design life of 20 years. Using the correlated design R-value of 23,
appropriate ESAL, environmental criteria and other factors, the structural numbers (SN) of the
pavement sections were determined on the basis of the 1993 AASHTO design equation.
In addition to the flexible pavement design analyses, a rigid pavement design analysis was
completed based upon AASHTO design procedures. Rigid pavement design is based on an
evaluation of the Modulus of Subgrade Reaction of the soils (k-value), the Modulus of Rupture of
the concrete, and other factors previously outlined. The design k-value of 100 for the subgrade
soil was determined by correlation to the laboratory test results. A modulus of rupture of 600 psi
(working stress 450 psi) was used for pavement concrete. The rigid pavement thickness for each
traffic category was determined on the basis of the AASHTO design equation.
Recommended minimum pavement sections are provided in the table below.
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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Alternative
Recommended Pavement Thicknesses (inches)
Asphaltic Concrete
Surface
Aggregate Base
Course
Portland Cement
Concrete Total
A 4 6 -- 10
B - - 5 5
Aggregate base course (if used on the site) should consist of a blend of sand and gravel which
meets strict specifications for quality and gradation. Use of materials meeting Colorado
Department of Transportation (CDOT) Class 5 or 6 specifications is recommended for aggregate
base course. Aggregate base course should be placed in lifts not exceeding 6 inches and
compacted to a minimum of 95 percent of the maximum dry unit weight as determined by ASTM
D698.
Asphaltic concrete should be composed of a mixture of aggregate, filler and additives (if required)
and approved bituminous material. The asphalt concrete should conform to approved mix
designs stating the Superpave properties, optimum asphalt content, job mix formula and
recommended mixing and placing temperatures. Aggregate used in asphalt concrete should
meet particular gradations. Material meeting CDOT Grading S or SX specifications or equivalent
is recommended for asphalt concrete. Mix designs should be submitted prior to construction to
verify their adequacy. Asphalt material should be placed in maximum 3-inch lifts and compacted
within a range of 92 to 96 percent of the theoretical maximum (Rice) density (ASTM D2041).
Where rigid pavements are used, the concrete should be produced from an approved mix design
with the following minimum properties:
Properties Value
Compressive strength 4,000 psi
Cement type Type I or II portland cement
Entrained air content (%) 5 to 8
Concrete aggregate ASTM C33 and CDOT section 703
Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 minutes
from the time the water is added to the mix. Longitudinal and transverse joints should be provided
as needed in concrete pavements for expansion/contraction and isolation per ACI 325. The
location and extent of joints should be based upon the final pavement geometry. Joints should
be sealed to prevent entry of foreign material and doweled where necessary for load transfer.
For areas subject to concentrated and repetitive loading conditions such as dumpster pads, truck
delivery docks and ingress/egress aprons, we recommend using a portland cement concrete
pavement with a thickness of at least 6 inches underlain by at least 4 inches of granular base.
Prior to placement of the granular base, the areas should be thoroughly proofrolled. For dumpster
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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pads, the concrete pavement area should be large enough to support the container and tipping
axle of the refuse truck.
Pavement performance is affected by its surroundings. In addition to providing preventive
maintenance, the civil engineer should consider the following recommendations in the design and
layout of pavements:
Site grades should slope a minimum of 2 percent away from the pavements;
The subgrade and the pavement surface have a minimum 2 percent slope to promote proper
surface drainage;
Consider appropriate edge drainage and pavement under drain systems;
Install pavement drainage surrounding areas anticipated for frequent wetting;
Install joint sealant and seal cracks immediately;
Seal all landscaped areas in, or adjacent to pavements to reduce moisture migration to
subgrade soils; and
Placing compacted, low permeability backfill against the exterior side of curb and gutter.
4.3.3 Pavements Construction Considerations
Openings in pavement, such as landscape islands, are sources for water infiltration into
surrounding pavements. Water collects in the islands and migrates into the surrounding subgrade
soils thereby degrading support of the pavement. This is especially applicable for islands with
raised concrete curbs, irrigated foliage, and low permeability near-surface soils. The civil design
for the pavements with these conditions should include features to restrict or to collect and
discharge excess water from the islands. Examples of features are edge drains connected to the
storm water collection system or other suitable outlet and impermeable barriers preventing lateral
migration of water such as a cutoff wall installed to a depth below the pavement structure.
4.3.4 Pavements Maintenance
Preventative maintenance should be planned and provided for an ongoing pavement
management program in order to enhance future pavement performance. Preventive
maintenance consists of both localized maintenance (e.g. crack and joint sealing and patching)
and global maintenance (e.g. surface sealing). Preventative maintenance is usually the first
priority when implementing a planned pavement maintenance program and provides the highest
return on investment for pavements.
5.0 GENERAL COMMENTS
Terracon should be retained to review the final design plans and specifications so comments can
be made regarding interpretation and implementation of our geotechnical recommendations in
the design and specifications. Terracon also should be retained to provide observation and testing
services during grading, excavation, pavement construction and other earth-related construction
phases of the project.
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
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The analysis and recommendations presented in this report are based upon the data obtained
from the borings performed at the indicated locations and from other information discussed in this
report. This report does not reflect variations that may occur between borings, across the site, or
due to the modifying effects of construction or weather. The nature and extent of such variations
may not become evident until during or after construction. If variations appear, we should be
immediately notified so that further evaluation and supplemental recommendations can be
provided.
The scope of services for this project does not include either specifically or by implication any
environmental or biological (e.g., mold, fungi, and bacteria) assessment of the site or identification
or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about
the potential for such contamination or pollution, other studies should be undertaken.
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 generally accepted geotechnical
engineering practices. No warranties, either express or implied, are intended or made. Site
safety, excavation support, and dewatering requirements are the responsibility of others. In the
event that changes in the nature, design, or location of the project as described in this report are
planned, the conclusions and recommendations contained in this report shall not be considered
valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this
report in writing.
APPENDIX A
FIELD EXPLORATION
TOPOGRAPHIC MAP IMAGE COURTESY OF
THE U.S. GEOLOGICAL SURVEY
QUADRANGLES INCLUDE: FORT COLLINS,
CO (1984).
SITE LOCATION
Front Range Colorado Hospitality Project City
Roadways
354 Walnut Street
Fort Collins, CO
20145072
DIAGRAM IS FOR GENERAL LOCATION ONLY,
AND IS NOT INTENDED FOR CONSTRUCTION
PURPOSES
MGH
EDB
EDB
EDB
7/21/2017
-
Exhibit
SITE
20145072 EXPLORATION PLAN
AERIAL PHOTOGRAPHY PROVIDED BY
MICROSOFT BING MAPS
Front Range Colorado Hospitality Project City
Roadways
354 Walnut Street
Fort Collins, CO
DIAGRAM IS FOR GENERAL LOCATION ONLY,
AND IS NOT INTENDED FOR CONSTRUCTION
PURPOSES
MGH
EDB
EDB
EDB
7/21/2017
AS SHOWN -
Exhibit
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
Responsive Resourceful Reliable Exhibit A-3
Field Exploration Description
The locations of borings were based upon the proposed city roadway widening and realignment
shown on the provided site plan. The borings were located in the field by measuring existing site
features. The ground surface elevation was surveyed at each boring location
level and referencing the sewer manhole cover as the temporary benchmark with an assumed
shown on Exhibit A-2.
The borings were drilled with a CME-55 truck-mounted rotary drill rig with solid-stem augers.
During the drilling operations, lithologic logs of the borings were recorded by the field engineer.
Disturbed samples were obtained at selected intervals utilizing a 2-inch outside diameter split-
spoon sampler and a 3-inch outside diameter ring-barrel sampler. Disturbed bulk samples were
obtained from auger cuttings and combined into a bulk sample from about 0 to 5 feet from all the
borings. Penetration resistance values were recorded in a manner similar to the standard
penetration test (SPT). This test consists of driving the sampler into the ground with a 140-pound
hammer free-falling through a distance of 30 inches. The number of blows required to advance
the ring-barrel sampler 12 inches (18 inches for standard split-spoon samplers, final 12 inches
are recorded) or the interval indicated, is recorded as a standard penetration resistance value (N-
value). The blow count values are indicated on the boring logs at the respective sample depths.
Ring-barrel sample blow counts are not considered N-values.
A CME automatic SPT hammer was used to advance the samplers in the borings performed on this
site. A greater efficiency is typically achieved with the automatic hammer compared to the
conventional safety hammer operated with a cathead and rope. Published correlations between the
SPT values and soil properties are based on the lower efficiency cathead and rope method. This
higher efficiency affects the standard penetration resistance blow count value by increasing the
penetration per hammer blow over what would be obtained using the cathead and rope method. The
effect of the automatic hammer's efficiency has been considered in the interpretation and analysis of
the subsurface information for this report.
The standard penetration test provides a reasonable indication of the in-place density of sandy
type materials, but only provides an indication of the relative stiffness of cohesive materials since
the blow count in these soils may be affected by the moisture content of the soil. In addition,
considerable care should be exercised in interpreting the N-values in gravelly soils, particularly
where the size of the gravel particle exceeds the inside diameter of the sampler.
Groundwater measurements were obtained in the borings at the time of site exploration. After
completion of drilling, the borings were backfilled with auger cuttings. Some settlement of the
backfill and/or patch may occur and should be repaired as soon as possible.
17-29
16-50/5"
18-50/6"
0.3
0.7
2.5
8.0
10.0
ASPHALT, approximately 4 inches
AGGREGATE BASE COURSE, approximately 4 inches
FILL: SANDY LEAN CLAY to CLAYEY SAND, with gravel, dark
brown to brown
SILTY CLAYEY GRAVEL WITH SAND (GC-GM), red brown to
brown, very dense
SILTY SAND (SM), fine grained, light brown to gray, very dense
Boring Terminated at 10 Feet
3
5
16
107
120 19-15-4
NP
98
97.5
96
90.5
88.5
GRAPHIC LOG
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20145072 NEW PAVEMENTS.GPJ TERRACON_DATATEMPLATE.GDT 7/21/17
FIELD TEST
RESULTS
SWELL / LOAD
(%/psf)
354 Walnut Street
Fort Collins, Colorado
SITE:
Page 1 of 1
Advancement Method:
4-inch solid-stem augers
Abandonment Method:
Backfilled with soil cuttings upon completion.
Notes:
Project No.: 20145072
Drill Rig: CME-55
Boring Started: 7/14/2017
BORING LOG NO. 1
CLIENT: FCMWC, LLC
Loveland, Colorado
Driller: Terracon
Boring Completed: 7/14/2017
Exhibit: A-4
See Exhibit A-3 for description of field procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
PROJECT: Front Range Colorado Hospitality Project
City Roadways
1901 Sharp Point Dr Ste C
9-13
50/4"
45-50/6"
-0.6/150
3.0
10.0
FILL: SANDY LEAN CLAY WITH GRAVEL (CL), brown to dark
brown and ligh brown
SILTY CLAYEY GRAVEL WITH SAND, red/orange brown to brown,
very dense
Boring Terminated at 10 Feet
13
4
6
112
112
32-17-15
98
91
GRAPHIC LOG
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20145072 NEW PAVEMENTS.GPJ TERRACON_DATATEMPLATE.GDT 7/21/17
FIELD TEST
RESULTS
SWELL / LOAD
(%/psf)
354 Walnut Street
Fort Collins, Colorado
SITE:
Page 1 of 1
Advancement Method:
4-inch solid-stem augers
Abandonment Method:
Backfilled with soil cuttings upon completion.
Notes:
Project No.: 20145072
Drill Rig: CME-55
Boring Started: 7/14/2017
BORING LOG NO. 2
CLIENT: FCMWC, LLC
Loveland, Colorado
Driller: Terracon
Boring Completed: 7/14/2017
Exhibit: A-5
See Exhibit A-3 for description of field procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
PROJECT: Front Range Colorado Hospitality Project
City Roadways
1901 Sharp Point Dr Ste C
Fort Collins, CO
No free water observed
WATER LEVEL OBSERVATIONS
DEPTH
LOCATION
Latitude: 40.58751° Longitude: -105.07362°
See Exhibit A-2
WATER
7-11
19-37-50/5"
50/5"
-1.5/150
0.4
0.6
3.0
9.4
ASPHALT, approximately 5 inches
AGGREGATE BASE COURSE, approximately 3 inches
FILL: SANDY LEAN CLAY, with gravel, dark brown to brown
SILTY CLAYEY GRAVEL WITH SAND, with gravel, red brown to
brown, very dense
Boring Terminated at 9.4 Feet
12
2
2
116 36-18-18
98
97.5
95.5
89
GRAPHIC LOG
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20145072 NEW PAVEMENTS.GPJ TERRACON_DATATEMPLATE.GDT 7/21/17
FIELD TEST
RESULTS
SWELL / LOAD
(%/psf)
354 Walnut Street
Fort Collins, Colorado
SITE:
Page 1 of 1
Advancement Method:
4-inch solid-stem augers
Abandonment Method:
Backfilled with soil cuttings upon completion.
Notes:
Project No.: 20145072
Drill Rig: CME-55
Boring Started: 7/14/2017
BORING LOG NO. 3
CLIENT: FCMWC, LLC
Loveland, Colorado
Driller: Terracon
Boring Completed: 7/14/2017
Exhibit: A-6
See Exhibit A-3 for description of field procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
PROJECT: Front Range Colorado Hospitality Project
City Roadways
1901 Sharp Point Dr Ste C
Fort Collins, CO
No free water observed
WATER LEVEL OBSERVATIONS
DEPTH
LOCATION
APPENDIX B
LABORATORY TESTING
Geotechnical Engineering Report
Front Range Colorado Hospitality Project City Roadways Fort Collins, Colorado
July 21, 2017 Terracon Project No. 20145072
Responsive Resourceful Reliable Exhibit B-1
Laboratory Testing Description
The soil samples retrieved during the field exploration were returned to the laboratory for
observation by the project geotechnical engineer. At that time, the field descriptions were
reviewed and an applicable laboratory testing program was formulated to determine engineering
properties of the subsurface materials.
Laboratory tests were conducted on selected soil samples. The results of these tests are
presented on the boring logs and in this appendix. The test results were used for the geotechnical
engineering analyses, and the development of pavement and earthwork recommendations. The
laboratory tests were performed in general accordance with applicable locally accepted
standards. Soil samples were classified in general accordance with the Unified Soil Classification
System described in Appendix C. Procedural standards noted in this report are for reference to
methodology in general. In some cases, variations to methods are applied as a result of local
practice or professional judgment.
Water content Plasticity index
Grain-size distribution
Consolidation/swell
Water-soluble sulfate content
Dry density
R-value
0
10
20
30
40
50
60
0 20 40 60 80 100
CL or OL CH or OH
ML or OL
MH or OH
"U" Line
"A" Line
ATTERBERG LIMITS RESULTS
ASTM D4318
P
L
A
S
T
I
C
I
T
Y
I
N
D
E
X
LIQUID LIMIT
PROJECT NUMBER: 20145072
PROJECT: Front Range Colorado Hospitality
Project City Roadways
SITE: 354 Walnut Street
Fort Collins, Colorado
CLIENT: FCMWC, LLC
Loveland, Colorado
EXHIBIT: B-2
1901 Sharp Point Dr Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20145072 NEW PAVEMENTS.GPJ TERRACON_DATATEMPLATE.GDT 7/21/17
4 - 4.9
9 - 10
2 - 3
2 - 3
0 - 5
1
1
2
3
BULK
LL USCS
15
23
52
61
37
4
NP
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
100 10 1 0.1 0.01 0.001
30 40
1.5 50
6 8 200
4 10 14
1 3/4
1/2 60
GRAIN SIZE IN MILLIMETERS
PERCENT FINER BY WEIGHT
U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
4 3/8
3 3 100 140
2
GRAIN SIZE DISTRIBUTION
ASTM D422 / ASTM C136
6 16
20
PROJECT NUMBER: 20145072
PROJECT: Front Range Colorado Hospitality
Project City Roadways
SITE: 354 Walnut Street
Fort Collins, Colorado
CLIENT: FCMWC, LLC
Loveland, Colorado
EXHIBIT: B-3
1901 Sharp Point Dr Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20145072 NEW PAVEMENTS.GPJ TERRACON_DATATEMPLATE.GDT 7/21/17
48.0
8.3
21.4
0.0
12.6
50
25
50
4.75
19
9.794
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.6 percent compression upon wetting under an applied pressure of 150 psf.
PROJECT: Front Range Colorado PROJECT NUMBER: 20145072
Hospitality Project City
Roadways
SITE: 354 Walnut Street
Fort Collins, Colorado
CLIENT: FCMWC, LLC
Loveland, Colorado
EXHIBIT: B-4
1901 Sharp Point Dr Ste C
Fort Collins, CO
Specimen Identification Classification , pcf
2 112 13
WC, %
2 - 3 ft SANDY LEAN CLAY with GRAVEL(CL)
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20145072 NEW PAVEMENTS.GPJ TERRACON_DATATEMPLATE.GDT 7/21/17
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 1.5 percent compression upon wetting under an applied pressure of 150 psf.
PROJECT: Front Range Colorado PROJECT NUMBER: 20145072
Hospitality Project City
Roadways
SITE: 354 Walnut Street
Fort Collins, Colorado
CLIENT: FCMWC, LLC
Loveland, Colorado
EXHIBIT: B-5
1901 Sharp Point Dr Ste C
Fort Collins, CO
Specimen Identification Classification , pcf
3 116 12
WC, %
2 - 3 ft SANDY LEAN CLAY(CL)
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20145072 NEW PAVEMENTS.GPJ TERRACON_DATATEMPLATE.GDT 7/21/17
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado 80525
(970) 484-0359 FAX (970) 484-0454
CLIENT: DATE OF TEST: 20-Jul-17
PROJECT: Front Range Colorado Hospitality Project
LOCATION: Bulk from all borings at depths of about 0 to 5 feet
TERRACON NO. 20145072 CLASSIFICATION: Clayey Sand (SC)
TEST SPECIMEN NO. 1 2 3
COMPACTION PRESSURE (PSI) 80 130 180
DENSITY (PCF) 112.0 116.2 121.1
MOISTURE CONTENT (%) 18.0 15.3 12.4
EXPANSION PRESSURE (PSI) -0.28 -0.13 -0.09
HORIZONTAL PRESSURE @ 160 PSI 128 115 115
SAMPLE HEIGHT (INCHES) 2.53 2.55 2.51
EXUDATION PRESSURE (PSI) 190.1 303.4 387.4
CORRECTED R-VALUE 15.2 23.0 25.3
UNCORRECTED R-VALUE 15.2 23.0 25.3
R-VALUE @ 300 PSI EXUDATION PRESSURE = 23
AASHTO T190
PRESSURE OF COMPACTED SOIL
RESISTANCE R-VALUE & EXPANSION
SAMPLE DATA TEST RESULTS
0
10
20
30
40
50
60
70
80
90
100
0 100 200 300 400 500 600 700 800
R-VALUE
EXUDATION PRESSURE - PSI
EXHIBIT: B-6
FCMWC, LLC
APPENDIX C
SUPPORTING DOCUMENTS
Exhibit: C-1
Unconfined Compressive Strength
Qu, (psf)
500 to 1,000
2,000 to 4,000
4,000 to 8,000
1,000 to 2,000
less than 500
> 8,000
Modified
Dames &
Moore Ring
Sampler
Grab
Sample
Standard
Penetration
Test
Non-plastic
Low
Medium
High
DESCRIPTION OF SYMBOLS AND ABBREVIATIONS
GENERAL NOTES
Over 12 in. (300 mm)
12 in. to 3 in. (300mm to 75mm)
3 in. to #4 sieve (75mm to 4.75 mm)
#4 to #200 sieve (4.75mm to 0.075mm
Passing #200 sieve (0.075mm)
Particle Size
< 5
5 - 12
> 12
Percent of
Dry Weight
Descriptive Term(s)
of other constituents
RELATIVE PROPORTIONS OF FINES
0
1 - 10
11 - 30
> 30
Plasticity Index
Soil classification is based on the Unified Soil 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.
LOCATION AND ELEVATION NOTES
Percent of
Dry Weight
Major Component
of Sample
Trace
With
Modifier
RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY
Trace
With
UNIFIED SOIL CLASSIFICATION SYSTEM
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A
Soil Classification
Group
Symbol Group Name B
Coarse Grained Soils:
More than 50% retained
on No. 200 sieve
Gravels:
More than 50% of
coarse fraction retained
on No. 4 sieve
Clean Gravels:
Less than 5% fines C
Cu 4 and 1 Cc 3 E GW Well-graded gravel F
Cu 4 and/or 1 Cc 3 E GP Poorly graded gravel F
Gravels with Fines:
More than 12% fines C
Fines classify as ML or MH GM Silty gravel F,G,H
Fines classify as CL or CH GC Clayey gravel F,G,H
Sands:
50% or more of coarse
fraction passes No. 4
sieve
Clean Sands:
Less than 5% fines D
Cu 6 and 1 Cc 3 E SW Well-graded sand I
Cu 6 and/or 1 Cc 3 E SP Poorly graded sand I
Sands with Fines:
More than 12% fines D
Fines classify as ML or MH SM Silty sand G,H,I
Fines classify as CL or CH SC Clayey sand G,H,I
Fine-Grained Soils:
50% or more passes the
No. 200 sieve
Silts and Clays:
Liquid limit less than 50
Inorganic:
PI 7 and plots on or above “A” line J CL Lean clay K,L,M
PI 4 or plots below “A” line J ML Silt K,L,M
Organic:
Liquid limit - oven dried
0.75 OL
Organic clay K,L,M,N
Liquid limit - not dried Organic silt K,L,M,O
Silts and Clays:
Liquid limit 50 or more
Inorganic:
PI plots on or above “A” line CH Fat clay K,L,M
PI plots below “A” line MH Elastic Silt K,L,M
Organic:
Liquid limit - oven dried
0.75 OH
Organic clay K,L,M,P
Liquid limit - not dried Organic silt K,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-inch (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 =
10 60
2
30
D x D
(D )
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.
H If 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.
Exhibit: C-2
Modifier
DESCRIPTIVE SOIL CLASSIFICATION
Boulders
Cobbles
Gravel
Sand
Silt or Clay
Descriptive Term(s)
of other constituents
< 15
15 - 29
> 30
Term
PLASTICITY DESCRIPTION
Water levels indicated on the soil boring
logs are the levels measured in the
borehole at the times indicated.
Groundwater level variations will occur
over time. In low permeability soils,
accurate determination of groundwater
levels is not possible with short term water
level observations.
Water Level After
a Specified Period of Time
Water Level After a
Specified Period of Time
Water Initially
Encountered
Standard Penetration Test
Resistance (Blows/Ft.)
Hand Penetrometer
Torvane
Dynamic Cone Penetrometer
Photo-Ionization Detector
Organic Vapor Analyzer
Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracy
of such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical survey was
conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic
maps of the area.
N
(HP)
(T)
(DCP)
(PID)
(OVA)
FIELD TESTS
WATER LEVEL
STRENGTH TERMS SAMPLING
Standard Penetration or
N-Value
Blows/Ft.
Descriptive Term
(Consistency)
Descriptive Term
(Density)
CONSISTENCY OF FINE-GRAINED SOILS
(50% or more passing the No. 200 sieve.)
Consistency determined by laboratory shear strength testing, field
visual-manual procedures or standard penetration resistance
Standard Penetration or
N-Value
Blows/Ft.
(More than 50% retained on No. 200 sieve.)
Density determined by Standard Penetration Resistance
RELATIVE DENSITY OF COARSE-GRAINED SOILS
Hard > 30
> 50 Very Stiff 15 - 30
Stiff
Medium Stiff
Very Soft 0 - 1
Medium Dense
Loose Soft
Very Dense
Dense 30 - 50 8 - 15
10 - 29 4 - 8
4 - 9 2 - 4
Very Loose 0 - 3
0.128
0.182
0.298
0.468
0.083
19
NP
32
36
25
1
1
2
3
BULK
LL PL PI
finefine
SILT OR CLAY
%Gravel %Sand
COBBLES GRAVEL SAND
coarse medium
%Clay
15.4
23.4
51.7
61.1
37.0
%Silt %Fines
SILTY, CLAYEY GRAVEL with SAND (GC-GM)
SILTY SAND (SM)
SANDY LEAN CLAY with GRAVEL (CL)
SANDY LEAN CLAY (CL)
CLAYEY SAND (SC)
USCS Classification
5
16
13
12
WC (%)
4 - 4.9
9 - 10
2 - 3
2 - 3
0 - 5
Boring ID Depth
Boring ID Depth
D60
36.6
68.3
26.9
38.9
50.4
4 - 4.9
9 - 10
2 - 3
2 - 3
0 - 5
D30 D10
Cc Cu
D100
4
NP
15
18
9
15
NP
17
18
16
coarse
1
1
2
3
BULK
15
18
9
15
NP
17
18
16
19
NP
32
36
25
Fines
GC-GM
SM
CL
CL
SC
SILTY, CLAYEY GRAVEL with SAND
SILTY SAND
SANDY LEAN CLAY with GRAVEL
SANDY LEAN CLAY
CLAYEY SAND
Boring ID Depth PL PI Description
CL-ML
Latitude: 40.5872° Longitude: -105.0738°
See Exhibit A-2
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 98.3 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
SAMPLE TYPE
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 100.8 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
SAMPLE TYPE
Fort Collins, CO
No free water observed
WATER LEVEL OBSERVATIONS
DEPTH
LOCATION
Latitude: 40.5879° Longitude: -105.07326°
See Exhibit A-2
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 98.4 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
SAMPLE TYPE