HomeMy WebLinkAboutBID - 7544 OLD TOWN PARKING GARAGE CANOPYADDENDUM NO. 1
SPECIFICATIONS AND CONTRACT DOCUMENTS
Description of BID 7544: Old Town Parking Garage Canopy
OPENING DATE: 3:00 PM (Our Clock) August 22, 2013
To all prospective bidders under the specifications and contract documents described
above, the following changes/additions are hereby made and detailed in the following
sections of this addendum:
Exhibit 1 – Geotechnical Engineering Report
Please contact John Stephen, CPPO, LEED AP, Senior Buyer at (970) 221-6777 with
any questions regarding this addendum.
RECEIPT OF THIS ADDENDUM MUST BE ACKNOWLEDGED BY A WRITTEN
STATEMENT ENCLOSED WITH THE BID/QUOTE STATING THAT THIS
ADDENDUM HAS BEEN RECEIVED.
Financial Services
Purchasing Division
215 N. Mason St. 2nd Floor
PO Box 580
Fort Collins, CO 80522
970.221.6775
970.221.6707
fcgov.com/purchasing
Geotechnical Engineering Report
Remington Parking Garage West Canopy
Southeast of Remington Street and East Mountain Avenue
Fort Collins, Colorado
June 17, 2013
Terracon Project No. 20135016
Prepared for:
RB+B Architects, Inc.
Fort Collins, Colorado
Prepared by:
Terracon Consultants, Inc.
Fort Collins, Colorado
TABLE OF CONTENTS
Page
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 Groundwater ........................................................................................................3
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION ......................................3
4.1 Geotechnical Considerations ...............................................................................3
4.1.1 Existing, Undocumented Fill .....................................................................3
4.1.2 Groundwater .............................................................................................4
4.1.3 Expansive Soils ........................................................................................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 ........................................................................7
4.2.6 Grading and Drainage ...............................................................................7
4.2.7 Corrosion Protection ..................................................................................8
4.3 Foundations .........................................................................................................8
4.3.1 Drilled Piers Bottomed in Bedrock - Design Recommendations ................8
4.3.2 Drilled Piers Bottomed in Bedrock - Construction Considerations .............9
4.4 Seismic Considerations......................................................................................10
5.0 GENERAL COMMENTS ...............................................................................................10
TABLE OF CONTENTS (continued)
Appendix A – FIELD EXPLORATION
Exhibit A-1 Site Location Map
Exhibit A-2 Boring Location Plan
Exhibit A-3 Field Exploration Description
Exhibits A-4 and A-5 Boring Logs for Current Study
Exhibits A-6 to A-11 Boring Logs from Previous Studies
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
Exhibit B-4 Swell-consolidation Test Results
Appendix C – SUPPORTING DOCUMENTS
Exhibit C-1 Explanation of Boring Log Information
Exhibit C-2 Unified Soil Classification System
Exhibit C-3 Description of Rock Properties
Exhibit C-4 Laboratory Test Significance and Purpose
Exhibits C-5 and C-6 Report Terminology
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
Responsive Ŷ Resourceful Ŷ Reliable i
EXECUTIVE SUMMARY
A geotechnical investigation has been performed for the proposed Remington Parking Garage
West Canopy to be constructed southeast of the intersection of Remington Street and East
Mountain Avenue in Fort Collins, Colorado. Two (2) borings, presented as Exhibits A-4 through
A-5 and designated as Boring No. 1 through Boring No. 2, were performed to depths of
approximately 11½ feet below existing site grades. This report specifically addresses the
recommendations for the proposed canopy on the west side of the parking garage. 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:
Existing, undocumented fill was encountered in the borings performed on this site to a
depth of about 3 feet below existing concrete surfaces. The use of deep foundation
systems such as drilled piers bottomed in bedrock will not be affected by the existing fill as
the drilled shafts will penetrate through the fill to proper bearing materials below the site.
However, the upper 3 feet of soil should be neglected during lateral load analysis.
The proposed canopy addition may be supported on a drilled pier foundation system
bottomed in bedrock.
The 2009 International Building Code, Table 1613.5.2 IBC seismic site classification for this
site is C.
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
Remington Parking Garage West Canopy
Southeast of Remington Street and East Mountain Avenue
Fort Collins, Colorado
Terracon Project No. 20135016
June 17, 2013
1.0 INTRODUCTION
This report presents the results of our geotechnical engineering services performed for the
proposed Remington Parking Garage West Canopy to be located southeast of the intersection of
Remington Street and East Mountain Avenue in Fort Collins, Colorado. The purpose of these
services is to provide information and geotechnical engineering recommendations relative to:
subsurface soil and bedrock conditions foundation design and construction
groundwater conditions earthwork
grading and drainage seismic considerations
Our geotechnical engineering scope of work for this project included the initial site visit, the
advancement of two (2) test borings to depths of approximately 11½ feet below existing site
grades, laboratory testing for soil engineering properties and engineering analyses to provide
foundation design and construction recommendations. Considering practical auger refusal
occurred in each of our two (2) borings completed for this study at elevations above
recommended foundations depths for the proposed addition, our scope of services also
included review of available geotechnical data obtained during previous studies near this site to
assist with developing geotechnical design and construction criteria for this project.
Logs of the borings along with a Boring Location 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.
2.0 PROJECT INFORMATION
2.1 Project Description
Item Description
Site layout Refer to the Boring Location Plan (Exhibit A-2 in Appendix A)
Proposed construction We understand a stand-alone canopy is planned for the west
entrance/exit to the parking garage.
Maximum loads Canopy: 25 kips per column (max.)
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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2.2 Site Location and Description
Item Description
Location The site is located southeast of the intersection of Remington
Street and East Mountain Avenue in Fort Collins, Colorado.
Existing improvements
An existing three-story parking garage structure currently occupies
the site. The western entrance planned for the proposed canopy
addition consists of two exit lanes and one entrance lane into the
parking garage.
Surrounding developments
The site is bordered to the north and west by East Mountain
Avenue and Remington Street respectively with commercial/retail
beyond. The east and south are bordered by commercial/retail
space.
Current ground cover The proposed construction area is covered with concrete
pavements and curbs.
3.0 SUBSURFACE CONDITIONS
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 (feet) Consistency/Density/Hardness
Fill materials consisting of lean clay
About 3 feet below existing site
grades.
--
Sandy lean clay
About 8½ to 10 feet below
existing site grades.
Medium stiff to very stiff
Silty sand with gravel, and cobbles
To the maximum depth of
exploration of about 11 feet.
Medium dense
Terracon utilized a limited access drill rig to perform our field investigation due to the limited
access constrains of this site. During our field study, we encountered difficult drilling at depths of
approximately 11½ feet below existing site grades with practical auger refusal. The use of a
limited access drill rig limits the depth of drilling in some difficult subsurface conditions. However,
Terracon has previously completed several geotechnical field studies at site in close proximity to
the proposed canopy addition.
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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After reviewing boring logs from previous studies at locations to the north, south and east of this
site, we believe bedrock should be expected at depths of approximately 13 to 15 feet below the
existing concrete surface. We have included the boring logs from the previous studies in
Appendix A.
3.2 Laboratory Testing
One soil sample was selected for swell-consolidation testing and exhibited 1.1 percent
compression when wetted. The sandstone and siltstone bedrock expected below this site is
also considered to have low expansive potential or non-expansive. Samples of site soils
selected for plasticity testing exhibited medium plasticity with a liquid limit of 27 and a plasticity
index of 11. Laboratory test results are presented in Appendix B.
3.3 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. In previous studies completed in nearby areas,
groundwater was measured in some boreholes at depths ranging from 21 to 22 feet below site
grades. We believe groundwater may be present below this site at depths ranging from 20 to 25
feet below existing site grades.
Groundwater conditions can change with varying seasonal and weather conditions, and other
factors. The possibility of groundwater fluctuations should be considered when developing design
and construction plans for the project.
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
canopy.
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. However, we believe the fill was likely
placed during the construction of the existing concrete pavements and other improvements.
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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The use of a deep foundation system such as drilled piers bottomed in bedrock may not be
affected by the existed undocumented fill. The drilled piers bottomed in bedrock will penetrate
through the fill to bear in bedrock below this site. However, we recommend neglecting the
upper 3 feet of soils when analyzing foundations for lateral load capacity.
4.1.2 Groundwater
As previously stated, groundwater was measured at depths ranging from about 21 to 22 feet
below site grades during previously conducted field studies at nearby sites. Depending upon
the depth of groundwater encountered during construction below this site, steel casing may be
necessary to advance drilled pier foundation excavations.
4.1.3 Expansive Soils
Laboratory testing indicates the native clay soils exhibited slight compression to low expansive
potential at the samples in-situ moisture content. However, it is our opinion these materials will
exhibit a higher expansive potential if the clays undergo a significant loss of moisture.
This report provides recommendations to help mitigate the effects of soil shrinkage and
expansion. However, even if these procedures are followed, some movement in the canopy
should be anticipated. The severity of cracking and other damage will probably increase if any
modification of the site results in excessive wetting or drying of the expansive clays. Eliminating
the risk of movement and distress is generally not be feasible, but it may be possible to further
reduce the risk of movement if significantly more expensive measures are used during
construction. It is imperative the recommendations described in section 4.2.7 Grading and
Drainage of this report be followed to reduce movement.
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 and testing of engineered fills, subgrade preparation, subgrade stabilization,
and other geotechnical conditions exposed during the construction of the project.
4.2.1 Site Preparation
Demolition of the existing concrete flatwork and curbs 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.
4.2.2 Excavation
It is anticipated that excavations for the proposed construction can be accomplished with
conventional earthmoving equipment. Construction for the proposed canopy foundations will
require removal of existing flatwork, curb, and pavements prior to excavation.
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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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
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.
Although evidence of underground facilities such as septic tanks, vaults, and basements was not
observed during the site reconnaissance, such features could be encountered during construction.
If unexpected fills or underground facilities are encountered, such features should be removed
and the excavation thoroughly cleaned prior to backfill placement and/or construction.
4.2.3 Subgrade Preparation
After demolition of the existing concrete flatwork, curbs and pavements; the construction of the
drilled piers and pier caps; and any deleterious materials have been removed from the
construction areas, the top 8 inches of the exposed ground surface below repairs 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, flatwork patch, or pavement repairs
are placed.
After the bottom of the excavation has been compacted, engineered fill can be placed to bring
the flatwork and/or pavement patch subgrade to the desired grade. Engineered fill should be
placed in accordance with the recommendations presented in subsequent section 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 “crowded” 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
procedures, can be re-used as fill for the flatwork and/or pavement subgrade, and around pier
caps. It should be noted that on-site soils may require reworking to adjust the moisture content
to meet the compaction criteria.
All fill materials should be inorganic soils free of vegetation, debris, and fragments larger than 4
inches in size. Pea gravel or other similar non-cementitious, poorly-graded materials should not
be used as fill or backfill without the prior approval of Terracon.
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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Engineered fill should be placed and compacted in horizontal lifts, not exceeding 8 inches in loose
thickness, using equipment and procedures that will produce recommended moisture contents
and densities throughout the lift.
If crushed gravel or certain other granular materials are used it may be appropriate to specify
compaction criteria based on a relative density test. Compaction criteria based on relative
density should be evaluated based on a project specific basis. Imported soils (if required)
should meet the following material property requirements:
Gradation Percent finer by weight (ASTM C136)
4” 100
3” 70-100
No. 4 Sieve 50-100
No. 200 Sieve 15-50
Soil Properties Value
Liquid Limit 30 (max.)
Plastic Limit 15 (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.
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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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
8 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 D698
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
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 canopy,
existing buildings, and pavements 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 (if any) should be minimized or
eliminated. Water permitted to pond near or adjacent to the perimeter of the canopy (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.
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 the
structures, care should be taken that joints are properly sealed and maintained to prevent the
infiltration of surface water.
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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4.2.7 Corrosion Protection
Results of water-soluble sulfate testing indicate that ASTM Type I or II portland cement should
be specified for all project concrete on and below grade. Foundation concrete should be
designed for low sulfate exposure in accordance with the provisions of the ACI Design Manual,
Section 318, Chapter 4.
4.3 Foundations
The proposed canopy can be supported by a drilled pier foundation system bottomed in
bedrock. Design recommendations for foundations for the proposed canopy and related
structural elements are presented in the following paragraphs.
4.3.1 Drilled Piers Bottomed in Bedrock - Design Recommendations
Description Value
Minimum pier length 20 feet
Minimum pier diameter 18 inches
Minimum bedrock embedment 1 6 feet
Maximum end-bearing pressure 30,000 psf
Skin friction (for portion of pier embedded into bedrock) 2,500 psf
1. Drilled piers should be embedded into hard or very hard bedrock materials.
Piers should be considered to work in group action if the horizontal spacing is less than three
pier diameters. A minimum practical horizontal clear spacing between piers of at least three
diameters should be maintained, and adjacent piers should bear at the same elevation. The
capacity of individual piers must be reduced when considering the effects of group action.
Capacity reduction is a function of pier spacing and the number of piers within a group. If group
action analyses are necessary, capacity reduction factors can be provided for the analyses.
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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To satisfy forces in the horizontal direction using LPILE, piers may be designed for the following
lateral load criteria:
Parameters Clay Sand and
Gravel
Sandstone/siltstone
Bedrock
LPILE soil type1
Stiff clay
without free
water2
Sand
(above WT)
Stiff clay without free
water
Unit weight (pcf) 120 125 130
Average undrained shear strength (psf) 500 N/A 9,000
Average angle of internal friction, )
(degrees)
N/A 35 N/A
Coefficient of subgrade reaction, k (pci)*
100 - static
30 - cyclic
60
2,000- static
800 – cyclic
Strain, H50 (%) 0.010 N/A 0.004
1. For purposes of LPILE analysis, assume a groundwater depth of about 20 feet below existing
ground surface.
2. The upper 3 feet of soils should be neglected during lateral load analysis.
4.3.2 Drilled Piers Bottomed in Bedrock - Construction Considerations
Drilling to design depth should be possible with conventional single-flight power augers on the
majority of the site; however, specialized drilling equipment may be required for very hard bedrock
layers. Cobbles encountered during our field study, causing practical auger refusal, may cause
difficult drilling conditions. In addition, caving soils and groundwater indicate that temporary steel
casing will be required to properly drill the piers prior to concrete placement.
Groundwater should be removed from each pier hole prior to concrete placement. Pier concrete
should be placed immediately after completion of drilling and cleaning. If pier concrete cannot
be placed in dry conditions, a tremie should be used for concrete placement. The use of a
bottom-dump hopper, or an elephant's trunk discharging near the bottom of the hole where
concrete segregation will be minimized, is recommended. Due to potential sloughing and
raveling, foundation concrete quantities may exceed calculated geometric volumes.
Casing should be withdrawn in a slow continuous manner maintaining a sufficient head of
concrete to prevent infiltration of water or caving soils or the creation of voids in pier concrete.
Pier concrete should have a relatively high fluidity when placed in cased pier holes or through a
tremie. Pier concrete with slump in the range of 5 to 7 inches is recommended.
We recommend the sides of each pier should be mechanically roughened in the bedrock
bearing strata. This should be accomplished by a roughening tooth placed on the auger. Shaft
bearing surfaces must be cleaned prior to concrete placement. A representative of the
Terracon should observe the bearing surface and shaft configuration.
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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Free-fall concrete placement in piers will only be acceptable if provisions are taken to avoid
striking the concrete on the sides of the hole or reinforcing steel. The use of a bottom-dump
hopper, or an elephant's trunk discharging near the bottom of the hole where concrete
segregation will be minimized, is recommended.
4.4 Seismic Considerations
Code Used Site Classification
2009 International Building Code (IBC) 1 C 2
1. In general accordance with the 2009 International Building Code, Table 1613.5.2.
2. The 2009 International Building Code (IBC) requires a site soil profile determination extending a
depth of 100 feet for seismic site classification. The current scope requested does not include the
required 100 foot soil profile determination. The borings completed for this project extended to a
maximum depth of about 11½ feet, borings completed for previous studies extended to depths of
about 29.4 feet, and this seismic site class definition considers that similar soil and bedrock
conditions exist below the maximum depth of the subsurface exploration. Additional exploration to
deeper depths could be performed to confirm the conditions below the current depth of exploration.
Alternatively, a geophysical exploration could be utilized in order to attempt to justify a more favorable
seismic site class. However, we believe a higher seismic site class for this site is unlikely.
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, foundation construction and other earth-related
construction phases of the project.
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, 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
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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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
SITE LOCATION MAP
A-1
20135016
5/30/2013
EDB
BCJ
EDB
EDB
1” = 2,000’
Project Manager:
Drawn by:
Checked by:
Approved by:
Project No.
Scale:
File Name:
Date:
Exhibit
Project Site
Remington Parking Garage West Canopy
Southeast of Remington Street and East Mountain Avenue
1901Colorado Sharp Point Drive, Suite C Fort Collins, Colorado 80525 Fort Collins,
PH. (970) 484-0359 FAX. (970) 484-0454
0’ 1,000’ 2,000’
APPROXIMATE SCALE
BORING LOCATION PLAN
1901 Sharp Point Drive, Suite C Fort Collins, Colorado 80525 A-2
PH. (970) 484-0359 FAX. (970) 484-0454
20135016
5/30/2013
EDB
BCJ
EDB
EDB
1” = 80’
Project Manager:
Drawn by:
Checked by:
Approved by:
Project No.
Scale:
File Name:
Date:
DIAGRAM IS FOR GENERAL LOCATION Exhibit
ONLY, AND IS NOT INTENDED FOR
CONSTRUCTION PURPOSES
0’ 30’ 60’
APPROXIMATE SCALE
Approximate Boring Location
for current study.
Remington Parking Garage West Canopy
Southeast of Remington Street and East Mountain Avenue
Fort Collins, Colorado
LEGEND
1
2
Approximate Boring Location
for previous study (Terracon
Project No. 20025144; dated
August 14, 2002.)
Approximate Boring Location
for previous study (Terracon
Project No. 20065048; dated
May 3, 2006.)
1
2
1
2
3
4
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
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Field Exploration Description
The locations of borings were based upon the proposed development shown on the provided
site plan. The borings were located in the field by measuring from existing site features.
The borings were drilled with a limited access mini-rig with solid-stem augers. Prior to drilling
the borings, the existing concrete flatwork was cored with a 4-inch diameter core barrel. During
the drilling operations, lithologic logs of the borings were recorded by the field engineer.
Relatively undisturbed samples were obtained at selected intervals utilizing a 2-inch outside
diameter split-spoon sampler (SS) and a 3-inch outside diameter ring-barrel sampler (RS).
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 manual SPT safety hammer was used to advance the samplers in the borings performed on
this site. 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 soils moisture content. 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.
Practical auger refusal was encountered in each of the two (2) borings completed for this
geotechnical study at a depth of 11½ feet below the existing concrete surface.
Groundwater measurements were obtained in the borings at the time of site exploration. After
completion of drilling, the borings were backfilled with auger cuttings and sand. The core
specimen obtained from each boring location had an exposed aggregate surface. At the
request of the City of Fort Collins, we “seated” the core specimens into the upper portion of the
boring during backfill with non-shrink grout to reasonably restore appearances.
0.4
3.0
10.0
11.6
CONCRETE - 4.5 inches
FILL - LEAN CLAY, brown
SANDY LEAN CLAY, trace calcareous nodules, brown, stiff to
very stiff
COBBLES
Auger refusal at 11.6 Feet
Below
detectable
limits.
10
9
0
7-8
13-25
50/1"
N=50/1"
106 27-16-11
See Exhibit A-2
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Rope and Cathead
LOCATION
DEPTH
GRAPHIC LOG
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20135016.GPJ TERRACON2012.GDT 6/17/13
SE of Remington St. and E Mountain Ave.
Fort Collins, Colorado
SITE:
No free water observed.
WATER LEVEL OBSERVATIONS
PROJECT: Remington Parking Garage
West Canopy
Page 1 of 1
Advancement Method:
3-inch solid-stem flight auger
Abandonment Method:
Borings backfilled with soil cuttings and concrete core
upon completion.
,
Notes:
Project No.: 20135016
Drill Rig: Minirig
Boring Started: 5/20/2013
BORING LOG NO. 1
CLIENT: RB+B Architects Inc.
Fort Collins, Colorado
Driller: Unlimited Access Drilling
Boring Completed: 5/20/2013
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.
Sulfates (PPM)
SWELL (%)
WATER
0.5
3.0
8.5
11.0
11.5
CONCRETE - 5.5 inches
FILL - LEAN CLAY, brown
SANDY LEAN CLAY, trace calcareous nodules, brown, medium
stiff
SILTY SAND WITH GRAVEL, light brown red to white, medium
dense
COBBLES
Auger refusal at 11.5 Feet
8 -1.1
3
4-4
11-9-14
N=23
97
See Exhibit A-2
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Rope and Cathead
LOCATION
DEPTH
GRAPHIC LOG
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20135016.GPJ TERRACON2012.GDT 6/17/13
SE of Remington St. and E Mountain Ave.
Fort Collins, Colorado
SITE:
No free water observed.
WATER LEVEL OBSERVATIONS
PROJECT: Remington Parking Garage
West Canopy
Page 1 of 1
Advancement Method:
3-inch solid-stem flight auger
Abandonment Method:
Borings backfilled with soil cuttings and concrete core
upon completion.
,
Notes:
Project No.: 20135016
Drill Rig: Minirig
Boring Started: 5/20/2013
BORING LOG NO. 2
CLIENT: RB+B Architects Inc.
Fort Collins, Colorado
Driller: Unlimited Access Drilling
Boring Completed: 5/20/2013
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.
Sulfates (PPM)
SWELL (%)
WATER
CONTENT (%)
FIELD TEST
APPENDIX B
LABORATORY TESTING
Geotechnical Engineering Report
Remington Parking Garage West Canopy Ŷ Fort Collins, Colorado
June 17, 2013 Ŷ Terracon Project No. 20135016
Responsive Ŷ Resourceful Ŷ 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 foundation 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.
Water content Plasticity index
Grain-size distribution
Consolidation/swell
Dry density
Water-soluble sulfate content
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
PL PI
4.0
Boring ID Depth Description
CL SANDY LEAN CLAY
Fines
P
L
A
S
T
I
C
I
T
Y
I
N
D
E
X
LIQUID LIMIT
"U" Line
"A" Line
27 16 11 50
LL USCS
1
ATTERBERG LIMITS RESULTS
ASTM D4318
,
PROJECT NUMBER: 20135016
PROJECT: Remington Parking Garage West
Canopy
SITE: SE of Remington St. and E Mountain
Ave.
Fort Collins, Colorado
CLIENT: RB+B Architects Inc.
Fort Collins, Colorado
EXHIBIT: B-2
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20135016.GPJ FENCE PROJECT 1-8-13.GPJ 6/17/13
CL-ML
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
6 16
20 30
40 50
1.5 6 200
810
0.6 50.3
14
LL PL PI
%Silt %Clay
1 4
3/4 1/2
60
fine
U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS HYDROMETER
16 11
D100
Cc Cu
SILT OR CLAY
4
D30 D10 %Gravel %Sand
1 SANDY LEAN CLAY(CL) 27
1 9.5 0.109
4.0
GRAIN SIZE IN MILLIMETERS
PERCENT FINER BY WEIGHT
coarse fine
3/8 3 100
3 2 140
COBBLES
GRAVEL SAND
USCS Classification
49.1
D60
coarse medium
4.0
Boring ID Depth
Boring ID Depth
GRAIN SIZE DISTRIBUTION
-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 1.1 percent compression upon wetting under an applied pressure of
1,000 psf.
,
PROJECT NUMBER: 20135016
PROJECT: Remington Parking Garage West
Canopy
SITE: SE of Remington St. and E Mountain
Ave.
Fort Collins, Colorado
CLIENT: RB+B Architects Inc.
Fort Collins, Colorado
EXHIBIT: B-4
Specimen Identification
4.0 ft
Classification , pcf
2 97 8
WC, %
SANDY LEAN CLAY (CL)
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. CONSOL_STRAIN-USCS 20135016.GPJ FENCE PROJECT 1-8-13.GPJ 6/17/13
APPENDIX C
SUPPORTING DOCUMENTS
Boulders
Cobbles
Gravel
Sand
Silt or Clay
< 5
5 - 12
> 12
Trace
With
Modifier
RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY
Hard
Trace
With
Modifier
above 4.00 > 30
2.00 to 4.00
1.00 to 2.00
0.50 to 1.00
0.25 to 0.50
less than 0.25
(50% or more passing the No. 200 sieve.)
Consistency determined by laboratory shear strength testing, field
visual-manual procedures or standard penetration resistance
CONSISTENCY OF FINE-GRAINED SOILS
Very Loose
Loose
Medium Dense
Dense
Descriptive Term
(Density)
> 50
30 - 50
10 - 29
4 - 9
0 - 3
Water Level After a
Specified Period of Time
STENGTH TERMS
Std. Penetration Resistance
(blows per foot)
Very Stiff
Stiff
RELATIVE DENSITY OF COARSE-GRAINED SOILS
15 - 30
8 - 14
Medium-Stiff
Soft
Very Soft
Descriptive Term
(Consistency)
2 - 4
0 - 1
Std. Penetration Resistance
(blows per foot)
Undrained Shear Strength
(kips per square foot)
Very Dense
5 - 7
UNIFIED SOIL CLASSIFICATION SYSTEM
Exhibit C-2
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.
DESCRIPTION OF ROCK PROPERTIES
Exhibit C-3
WEATHERING
Fresh Rock fresh, crystals bright, few joints may show slight staining. Rock rings under hammer if crystalline.
Very slight Rock generally fresh, joints stained, some joints may show thin clay coatings, crystals in broken face show
bright. Rock rings under hammer if crystalline.
Slight Rock generally fresh, joints stained, and discoloration extends into rock up to 1 in. Joints may contain clay. In
granitoid rocks some occasional feldspar crystals are dull and discolored. Crystalline rocks ring under hammer.
Moderate Significant portions of rock show discoloration and weathering effects. In granitoid rocks, most feldspars are dull
and discolored; some show clayey. Rock has dull sound under hammer and shows significant loss of strength
as compared with fresh rock.
Moderately severe All rock except quartz discolored or stained. In granitoid rocks, all feldspars dull and discolored and majority
show kaolinization. Rock shows severe loss of strength and can be excavated with geologist’s pick.
Severe All rock except quartz discolored or stained. Rock “fabric” clear and evident, but reduced in strength to strong
soil. In granitoid rocks, all feldspars kaolinized to some extent. Some fragments of strong rock usually left.
Very severe All rock except quartz discolored or stained. Rock “fabric” discernible, but mass effectively reduced to “soil” with
only fragments of strong rock remaining.
Complete Rock reduced to ”soil”. Rock “fabric” not discernible or discernible only in small, scattered locations. Quartz may
be present as dikes or stringers.
HARDNESS (for engineering description of rock – not to be confused with Moh’s scale for minerals)
Very hard Cannot be scratched with knife or sharp pick. Breaking of hand specimens requires several hard blows of
geologist’s pick.
Hard Can be scratched with knife or pick only with difficulty. Hard blow of hammer required to detach hand specimen.
Moderately hard Can be scratched with knife or pick. Gouges or grooves to ¼ in. deep can be excavated by hard blow of point of
a geologist’s pick. Hand specimens can be detached by moderate blow.
Medium Can be grooved or gouged 1/16 in. deep by firm pressure on knife or pick point. Can be excavated in small
chips to pieces about 1-in. maximum size by hard blows of the point of a geologist’s pick.
Soft Can be gouged or grooved readily with knife or pick point. Can be excavated in chips to pieces several inches in
size by moderate blows of a pick point. Small thin pieces can be broken by finger pressure.
Very soft Can be carved with knife. Can be excavated readily with point of pick. Pieces 1-in. or more in thickness can be
broken with finger pressure. Can be scratched readily by fingernail.
Joint, Bedding, and Foliation Spacing in Rock
a
Spacing Joints Bedding/Foliation
Less than 2 in. Very close Very thin
2 in. – 1 ft. Close Thin
1 ft. – 3 ft. Moderately close Medium
3 ft. – 10 ft. Wide Thick
More than 10 ft. Very wide Very thick
a. Spacing refers to the distance normal to the planes, of the described feature, which are parallel to each other or nearly so.
Rock Quality Designator (RQD) a Joint Openness Descriptors
RQD, as a percentage Diagnostic description Openness Descriptor
Exceeding 90 Excellent No Visible Separation Tight
90 – 75 Good Less than 1/32 in. Slightly Open
75 – 50 Fair 1/32 to 1/8 in. Moderately Open
50 – 25 Poor 1/8 to 3/8 in. Open
Less than 25 Very poor 3/8 in. to 0.1 ft. Moderately Wide
a. RQD (given as a percentage) = length of core in pieces Greater than 0.1 ft. Wide
4 in. and longer/length of run.
References: American Society of Civil Engineers. Manuals and Reports on Engineering Practice - No. 56. Subsurface Investigation for
Design and Construction of Foundations of Buildings. New York: American Society of Civil Engineers, 1976. U.S.
Department of the Interior, Bureau of Reclamation, Engineering Geology Field Manual.
Exhibit C-4
LABORATORY TEST
SIGNIFICANCE AND PURPOSE
Test Significance Purpose
California Bearing
Ratio
Used to evaluate the potential strength of subgrade soil,
subbase, and base course material, including recycled
materials for use in road and airfield pavements.
Pavement Thickness
Design
Consolidation
Used to develop an estimate of both the rate and amount of
both differential and total settlement of a structure. Foundation Design
Direct Shear
Used to determine the consolidated drained shear strength
of soil or rock.
Bearing Capacity,
Foundation Design,
and Slope Stability
Dry Density
Used to determine the in-place density of natural, inorganic,
fine-grained soils.
Index Property Soil
Behavior
Expansion
Used to measure the expansive potential of fine-grained
soil and to provide a basis for swell potential classification.
Foundation and Slab
Design
Gradation
Used for the quantitative determination of the distribution of
particle sizes in soil. Soil Classification
Liquid & Plastic Limit,
Plasticity Index
Used as an integral part of engineering classification
systems to characterize the fine-grained fraction of soils,
and to specify the fine-grained fraction of construction
materials.
Soil Classification
Permeability
Used to determine the capacity of soil or rock to conduct a
liquid or gas.
Groundwater Flow
Analysis
pH
Used to determine the degree of acidity or alkalinity of a
soil. Corrosion Potential
Resistivity
Used to indicate the relative ability of a soil medium to carry
electrical currents. Corrosion Potential
R-Value
Used to evaluate the potential strength of subgrade soil,
subbase, and base course material, including recycled
materials for use in road and airfield pavements.
Pavement Thickness
Design
Soluble Sulfate
Used to determine the quantitative amount of soluble
sulfates within a soil mass. Corrosion Potential
Exhibit C-5
REPORT TERMINOLOGY
(Based on ASTM D653)
Allowable Soil
Bearing Capacity
The recommended maximum contact stress developed at the interface of the foundation
element and the supporting material.
Alluvium
Soil, the constituents of which have been transported in suspension by flowing water and
subsequently deposited by sedimentation.
Aggregate Base
Course
A layer of specified material placed on a subgrade or subbase usually beneath slabs or
pavements.
Backfill A specified material placed and compacted in a confined area.
Bedrock
A natural aggregate of mineral grains connected by strong and permanent cohesive forces.
Usually requires drilling, wedging, blasting or other methods of extraordinary force for
excavation.
Bench A horizontal surface in a sloped deposit.
Caisson (Drilled
Pier or Shaft)
A concrete foundation element cast in a circular excavation which may have an enlarged
base. Sometimes referred to as a cast-in-place pier or drilled shaft.
Coefficient of
Friction
A constant proportionality factor relating normal stress and the corresponding shear stress
at which sliding starts between the two surfaces.
Colluvium
Soil, the constituents of which have been deposited chiefly by gravity such as at the foot of a
slope or cliff.
Compaction The densification of a soil by means of mechanical manipulation
Concrete Slab-on-
Grade
A concrete surface layer cast directly upon a base, subbase or subgrade, and typically used
as a floor system.
Differential
Movement Unequal settlement or heave between, or within foundation elements of structure.
Earth Pressure The pressure exerted by soil on any boundary such as a foundation wall.
ESAL
Equivalent Single Axle Load, a criteria used to convert traffic to a uniform standard, (18,000
pound axle loads).
Engineered Fill
Specified material placed and compacted to specified density and/or moisture conditions
under observations of a representative of a geotechnical engineer.
Equivalent Fluid
A hypothetical fluid having a unit weight such that it will produce a pressure against a lateral
support presumed to be equivalent to that produced by the actual soil. This simplified
approach is valid only when deformation conditions are such that the pressure increases
linearly with depth and the wall friction is neglected.
Existing Fill (or
Man-Made Fill) Materials deposited throughout the action of man prior to exploration of the site.
Existing Grade The ground surface at the time of field exploration.
Exhibit C-6
REPORT TERMINOLOGY
(Based on ASTM D653)
Expansive Potential The potential of a soil to expand (increase in volume) due to absorption of moisture.
Finished Grade The final grade created as a part of the project.
Footing A portion of the foundation of a structure that transmits loads directly to the soil.
Foundation The lower part of a structure that transmits the loads to the soil or bedrock.
Frost Depth The depth at which the ground becomes frozen during the winter season.
Grade Beam
A foundation element or wall, typically constructed of reinforced concrete, used to span
between other foundation elements such as drilled piers.
Groundwater Subsurface water found in the zone of saturation of soils or within fractures in bedrock.
Heave Upward movement.
Lithologic
The characteristics which describe the composition and texture of soil and rock by
observation.
Native Grade The naturally occurring ground surface.
Native Soil Naturally occurring on-site soil, sometimes referred to as natural soil.
Optimum Moisture
Content
The water content at which a soil can be compacted to a maximum dry unit weight by a given
compactive effort.
Perched Water
Groundwater, usually of limited area maintained above a normal water elevation by the
presence of an intervening relatively impervious continuous stratum.
Scarify To mechanically loosen soil or break down existing soil structure.
Settlement Downward movement.
Skin Friction (Side
Shear)
The frictional resistance developed between soil and an element of the structure such as a
drilled pier.
Soil (Earth)
Sediments or other unconsolidated accumulations of solid particles produced by the physical
and chemical disintegration of rocks, and which may or may not contain organic matter.
Strain The change in length per unit of length in a given direction.
Stress The force per unit area acting within a soil mass.
Strip To remove from present location.
Subbase A layer of specified material in a pavement system between the subgrade and base course.
Subgrade The soil prepared and compacted to support a structure, slab or pavement system.
Unconfined
Compression
To obtain the approximate compressive strength of soils
that possess sufficient cohesion to permit testing in the
unconfined state.
Bearing Capacity
Analysis for
Foundations
Water Content
Used to determine the quantitative amount of water in a soil
mass.
Index Property Soil
Behavior
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.
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)
Descriptive Term(s)
of other constituents
Percent of
Dry Weight
Descriptive Term(s)
of other constituents
Percent of
Dry Weight
LOCATION AND ELEVATION NOTES
(HP)
(T)
(b/f)
(PID)
(OVA)
DESCRIPTION OF SYMBOLS AND ABBREVIATIONS
No Recovery Rock Core
Shelby Tube
< 15
15 - 29
> 30
Water Level After
a Specified Period of Time
Macro Core
Auger Split Spoon
(More than 50% retained on No. 200 sieve.)
Density determined by Standard Penetration Resistance
Exhibit C-1
FIELD TESTS
PLASTICITY DESCRIPTION
Term
Hand Penetrometer
Torvane
Standard Penetration
Test (blows per foot)
Photo-Ionization Detector
Organic Vapor Analyzer
DESCRIPTIVE SOIL CLASSIFICATION
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.
Non-plastic
Low
Medium
High
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.
Plasticity Index
0
1 - 10
11 - 30
> 30
RELATIVE PROPORTIONS OF FINES
Descriptive Term(s)
of other constituents
No Water Level Observed
Water levels indicated on the soil boring
logs are the levels measured in the
borehole at the times indicated. Water
level variations will occur over time. In
low permeability soils, accurate
determination of water levels is not
possible with short term water level
Ring Sampler observations.
Percent of
Dry Weight
SAMPLING
EXPLANATION OF BORING LOG INFORMATION
Water Level Initially
Encountered
WATER LEVEL OBSERVATIONS
ASTM D422
,
PROJECT NUMBER: 20135016
PROJECT: Remington Parking Garage West
Canopy
SITE: SE of Remington St. and E Mountain
Ave.
Fort Collins, Colorado
CLIENT: RB+B Architects Inc.
Fort Collins, Colorado
EXHIBIT: B-3
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20135016.GPJ FENCE PROJECT 1-8-13.GPJ 6/17/13
RESULTS
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
CONTENT (%)
FIELD TEST
RESULTS
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI