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GEOTECHNICAL ENGINEERING REPORT
CATTAIL CREEK PAVEMENT DESIGN
NORTHEAST CORNER OF WELD COUNTY ROADS 29 AND 70
WELD COUNTY, COLORADO
TERRACON PROJECT NO. 21045034
May 5, 2004
Prepared for:
Messner Engineering
150 East 29th Street
Loveland, Colorado 80538
Prepared by:
Terracon
1289 First Avenue
Greeley, Colorado 80631
Telephone (970) 351-0460
Fax (970) 353-8639
2004-1994
lierracon
lierracon
1289 First Avenue
May 5, 2004 Post Office Box 1744
Greeley,Colorado 80632-1744
(970)351-0460 Fax:(970)353-8839
t Messner Engineering
150 East 29th Street
Loveland, Colorado 80538
Attn: Mr. Dennis Messner, P.E.
Re: Geotechnical Engineering Report
Cattail Creek Pavement Design
Northeast Corner of Weld County Roads 29 and 70
- Weld County, Colorado
Terracon Project No. 21045034 '
Terracon has completed a geotechnical engineering exploration for the proposed access road for the
Cattail Creek P.U.D. to be located northeast of the intersection of Weld County Roads 29 and 70 in
Weld County, Colorado. This study was performed in general accordance with our proposal number
P2104067g dated April 12, 2004.
The results of our engineering study, including the boring location diagram, laboratory test results,
test boring records, and the geotechnical recommendations needed to aid in the design and
construction of pavements and other earth connected phases of this project are attached.
The subsurface soils at the site consisted of silty sands and well to poorly graded sands with silt. The
results of our field exploration and laboratory testing indicate that the soils at the site are non-
expansive. The soils at anticipated pavement subgrade elevation appear suitable for support of the
proposed pavements and have moderate subgrade strength characteristics for support of proposed
pavements.
Shallow groundwater was encountered at the site ranging from about 51/2 to 71/2 feet below existing
grade at the time of our subsurface exploration. Groundwater elevations at the site may vary based
on seasonal conditions, and may be influenced by the existing irrigation ditch located north and east
of the property. A rise in groundwater elevation to levels within 5 feet of the pavement subgrade
elevation may influence the performance of the proposed pavements resulting in a reduced pavement
life or increased maintenance. Terracon recommends proposed pavements bear a minimum of 5 feet
above maximum seasonal groundwater depths to provide for fluctuation in groundwater elevation due
to seasonal considerations or influence from the irrigation ditch.
Terracon recommends piezometers be constructed adjacent to the proposed roadway to monitor the
seasonal fluctuations in the groundwater prior to construction. If the groundwater rises a significant
level, the pavement section may need to be revised to provide a capillary break that will help reduce
the movement due toossible frost heave induced movement.
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Geotechnical Engineering Report
Cattail Creek Pavement Design
Terracon Project No. 21045034 Terracon
•
Further, subgrade soils within 3 feet of groundwater may require chemical stabilization (fly ash or
cement) or mechanical stabilization (overexcavation and replacement with granular fill over geogrid)
to facilitate proper construction of proposed pavements.
,
Other design and construction recommendations, based upon geotechnical conditions, are presented
in the report.
We appreciate being of service to you in the geotechnical engineering phase of this project, and are
prepared to assist you during the construction phases as well. If you have any questions concerning
this report or any of our testing, inspection, design and consulting services, please do not hesitate to
contact us.
Sincerely, .s. c~�•'G IXEX4llllll y..I.Os, �P A i )6,JTF,
• G
TERRAC0N _ :�, Oy:O o• P=;
F:
a 36512 = = I =
•51510 "`
a„ /ONIinn'" o,,i1AL - o'
Ty G. Alexander, P.E. Douglas J. Jobe, P.E.
Office Manager/Geotechnical Engineer Principal/Regional Manager
Copies to: Addressee (3)
.—
iii
TABLE OF CONTENTS
Page No.
Letter of Transmittal
INTRODUCTION 1
PROPOSED CONSTRUCTION 1
SITE EXPLORATION 7
Field Exploration 2
Laboratory Testing 2
SITE CONDITIONS 3
Soil and Bedrock Conditions 3
Field and Laboratory Test Results 3
Groundwater Conditions 3
ENGINEERING ANALYSES AND RECOMMENDATIONS 3
Geotechnical Considerations 3
Pavement Design and Construction 4
Earthwork 6
General Considerations 6
Site Preparation 6
} Fill Materials and Placement 7
Excavation and Trench Construction 8
Additional Design and Construction Considerations 8
Underground Utility Systems 8
GENERAL COMMENTS 8
APPENDIX A
Boring Location Plan
Logs of Borings
APPENDIX B
Laboratory Test Results
APPENDIX C
General Notes
Unified Soil Classification
GEOTECHNICAL ENGINEERING REPORT
CATTAIL CREEK PAVEMENT DESIGN
NORTHEAST CORNER OF WELD COUNTY ROADS 29 AND 70
WELD COUNTY, COLORADO
TERRACON PROJECT NO. 21045034
MAY 5, 2004
INTRODUCTION
This report contains the results of our geotechnical engineering exploration for the proposed access
road for the Cattail Creek P.U.D. to be located northeast of the intersection of Weld County Roads 29
and 70 in Weld County, Colorado.
The purpose of these services is to provide information and geotechnical engineering
recommendations relative to:
• subsurface soil and bedrock conditions
• groundwater conditions
• pavement design and construction
• earthwork
The recommendations contained in this report are based upon the results of field and laboratory
testing, engineering analyses, and experience with similar soil conditions, structures and our
understanding of the proposed project.
PROPOSED CONSTRUCTION
Terracon understands development for the proposed project will consist of construction of a single
paved residential street that will provide access to the development from Weld County Road 70.
Preliminary site grading plans provided by the client include fills of about 1 to 2 feet on the north side of
the street, cuts of about 1 foot in the center portion of the street, and fills of about 3 to 4 feet on the
southern portion of the street. Traffic loadings were not provided. Terracon assumes traffic loading
will be consistent with two lane residential streets as outlined in the City of Greeley Construction
Specifications.
SITE EXPLORATION
The scope of the services performed for this project included a site reconnaissance by a Terracon
representative, a subsurface exploration program, laboratory testing and engineering analyses.
Geotechnical Engineering Report
Cattail Creek Pavement Design
Terracon Project No. 21045034 Terracon
Field Exploration
Three test borings were drilled on April 21, 2004. The borings were drilled to approximate depths of
10 feet at the locations shown on the Site Plan, Appendix A. All borings were advanced with a truck-
mounted drilling rig utilizing 4-inch diameter solid stem augers.
The borings were located in the field by measurements from property lines and existing site features.
Ground surface elevations at each boring location were obtained by interpolation of a topographic site
plan provided by the client. The accuracy of boring locations and elevations should only be assumed
to the level implied by the methods used to determine each.
Lithologic logs of each boring were recorded by the field representative during the drilling operations.
At selected intervals, samples of the subsurface materials were taken by driving split-spoon and ring-
barrel samplers.
Penetration resistance measurements were obtained by driving the split-spoon and ring-barrel
samplers into the subsurface materials with a 140-pound hammer falling 30 inches. The penetration
resistance value is a useful index in estimating the consistency, relative density or hardness of the
materials encountered.
•
Groundwater conditions were evaluated in each boring at the time of site exploration, and 1 day after
r completion of drilling.
Laboratory Testing
All samples retrieved during the field exploration were retumed to the laboratory for observation by the
project geotechnical engineer and were classified in accordance with the Unified Soil Classification
System described in Appendix C. At that time, the field descriptions were confirmed or modified as
necessary and an applicable laboratory testing program was formulated to determine engineering
properties of the subsurface materials. Boring logs were prepared and are presented in Appendix A.
Laboratory tests were conducted on selected soil samples and are presented on the boring logs and in
Appendix B. The test results were used for the geotechnical engineering analyses, and the
development of foundation and earthwork recommendations. All laboratory tests were performed in
general accordance with the applicable local or other accepted standards.
Selected soil samples were tested for the following engineering properties:
• Water Content • Grain size
• Dry Density • Plasticity Index
• Consolidation
2
Geotechnical Engineering Report
Cattail Creek Pavement Design
Terracon Project No. 21045034 Terracon
SITE CONDITIONS
The site was developed for agricultural purposes at the time of our field exploration. The site was
vegetated with trimmed alfalfa and some weeds. Based on the topographic site plan provided, the
surface drainage at the site appears to be gently towards the east. The site is bordered to the south
by Weld County Road 70, to the north and west by open agricultural land, and to the east by an
irrigation ditch.
1 _
f
SUBSURFACE CONDITIONS
Soil and Bedrock Conditions
As presented on the Logs of Boring, surface soils to depths of 8 to 9%2 feet consisted of silty sand.
The materials underlying the surface soils and extending to the maximum depth of exploration
consisted of well to poorly graded sands with silt.
Field and Laboratory Test Results
1 - Field test results indicate that the sand soils vary from very loose to medium dense in relative
density. Laboratory test results indicate that subsoils at shallow are non-expansive.
f '
t_- Groundwater Conditions
Groundwater was encountered at approximate depths of 6 to 8 feet in the test borings at the time of
• field exploration. When checked 1 day after the drilling, groundwater was measured at approximate
depths of 5/to 7% feet. These observations represent groundwater conditions at the time of the field
exploration, and may not be indicative of other times, or at other locations. Groundwater levels can be
expected to fluctuate with varying seasonal and weather conditions.
ENGINEERING ANALYSES AND RECOMMENDATIONS
Geotechnical Considerations
The site appears suitable for the proposed construction from a geotechnical engineering point of view.
The subsurface soils at the site consisted of silty sands and well to poorly graded sands with silt. The
results of our field exploration and laboratory testing indicate that the soils at the site are non-
expansive. The soils at anticipated pavement subgrade elevation appear suitable for support of the
•
3
Geotechnical Engineering Report
Cattail Creek Pavement Design
Terracon Project No. 21045034 Terracon
proposed pavements and have moderate subgrade strength characteristics for support of proposed
pavements.
Shallow groundwater was encountered at the site ranging from about 51, to 7'/ feet below existing
grade at the time of our subsurface exploration. Groundwater elevations at the site may vary based
on seasonal conditions, and may be influenced by the existing irrigation ditch located north and east
of the property. A rise in groundwater elevation to levels within 5 feet of the pavement subgrade
elevation may influence the performance of the proposed pavements resulting in a reduced
pavement life or increased maintenance. Terracon recommends proposed pavements bear a
minimum of 5 feet above maximum seasonal groundwater depths to provide for fluctuation in
groundwater elevation due to seasonal considerations or influence from the irrigation ditch.
Terracon recommends piezometers be constructed adjacent to the roadway to monitor the seasonal
fluctuations in the groundwater prior to construction. If the groundwater rises a significant level, the
pavement section may need to be revised to provide a capillary break that will help reduce the
movement due to possible frost heave induced movement.
— Further, subgrade soils within 3 feet of groundwater may require chemical stabilization (fly ash or
cement) or mechanical stabilization (overexcavation and replacement with granular fill over geogrid)
to facilitate proper construction of proposed pavements.
Further, subgrade soils within 3 feet of groundwater may require chemical stabilization (fly ash or
cement) or mechanical stabilization (overexcavation and replacement with granular fill over geogrid) to
facilitate proper construction of proposed pavements.
Design and construction recommendations for pavements and other earth connected phases of the
project are outlined below.
Pavement Design and Construction
l . Design of pavements for the project have been based on the procedures outlined in the 1993
Guideline for Design of Pavement Structures by the American Association of State Highway and
Transportation Officials (AASHTO) as well as Colorado Department of Transportation (CDOT) design
procedures. Areas within proposed pavements on the site will be divided into two categories based
upon anticipated traffic and usage.
Traffic criteria assumed for pavement thickness designs include daily single 18-kip equivalent axle
loads (EAL's) of 36,500. The assumed traffic loading is based on our understanding the proposed
4
Geotechnical Engineering Report
Cattail Creek Pavement Design
Terracon Project No. 21045034 Terracon
roadway will be classified as a two lane residential street with a reference to City of Greeley
Construction Specification design standards.
Local drainage characteristics of proposed pavement areas are considered to vary from fair to good
depending upon location on the site. For purposes of this design analysis, fair drainage characteristics
are considered to control the design. These characteristics, coupled with the approximate duration of
saturated subgrade conditions, results in a design drainage coefficient of 0.9 when applying the
AASHTO criteria for design.
For flexible pavement design, a terminal serviceability index of 2.0 was utilized along with an inherent
reliability of 85% and a design life of 20 years. Using the correlated design R-value of 25, appropriate
EAL/day, environmental criteria and other factors, the structural numbers (SN) of the pavement
sections were determined on the basis of the 1993 AASHTO design equation.
Based on our analysis, the following minimum pavement thicknesses are recommended:
Traf0cArea ySafiF t t ' rrttc?` at+l a� r
Residential 3 4 7
Aggregate base course should consist of a blend of sand and gravel that meets specifications for
quality and gradation. Use of materials meeting Colorado Department of Transportation (CDOT)
Class 5 or 6 specifications is recommended for base course. Aggregate base course should be
placed in lifts not exceeding six inches and should be compacted to a minimum of 95% Standard
Proctor Density(ASTM D698).
Asphalt 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 Marshall or 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 Colorado Department of Transportation Grading S or SX specification 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 should be compacted
to within a range of 92% to 96% of maximum theoretical specific gravity.
5
Geotechnical Engineering Report
Cattail Creek Pavement Design
Terracon Project No. 21045034 Terracon
Earthwork
General Considerations
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. The evaluation of
earthwork should include observation and testing of engineered fill, subgrade preparation, pavement
bearing soils, and other geotechnical conditions exposed during the construction of the project.
! _ Site Preparation
Strip and remove existing vegetation, debris, and other deleterious materials from proposed pavement
areas. All exposed surfaces should be free of mounds and depressions that could prevent uniform
4 compaction.
Stripped materials consisting of vegetation and organic materials should be wasted from the site, or
used to revegetate landscaped areas or exposed slopes after completion of grading operations. If it is
necessary to dispose of organic materials on-site, they should be placed in non-structural areas, and
in fill sections not exceeding 5 feet in height.
The site should be initially graded to create a relatively level surface to receive fill, and to provide for a
relatively uniform thickness of fill beneath proposed pavements.
Subgrade soils beneath proposed pavements, as well as all exposed areas which will receive fill, once
properly cleared where necessary, should be scarified to a minimum depth of 12 inches, conditioned to
near optimum moisture content, and compacted.
Although evidence of fills or underground facilities such as septic tanks, cesspools, basements, and
utilities 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.
Depending upon depth of excavation and seasonal conditions, groundwater may be encountered in
excavations on the site. Pumping from sumps may be utilized to control water within excavations.
Well points may be required for significant groundwater flow, or where excavations penetrate
groundwater to a significant depth.
Based upon the subsurface conditions determined from the geotechnical exploration, subgrade soils a
minimum of 3 feet above the groundwater level exposed during construction are anticipated to be
6
Geotechnical Engineering Report
Cattail Creek Pavement Design
Terracon Project No. 21045034 Terracon
relatively stable. Soils encountered within 3 feet of groundwater will likely be unstable and require
some form of stabilization prior to construction of pavements. Further, the stability of the upper level
soils may be affected by precipitation, repetitive construction traffic or other factors. If unstable
conditions develop, workability may be improved by scarifying and drying. Overexcavation of wet
zones and replacement with granular materials may be necessary. Use of lime, fly ash, kiln dust,
cement or geotextiles could also be considered as a stabilization technique. Laboratory evaluation is
recommended to determine the effect of chemical stabilization on subgrade soils prior to construction.
The individual contractor(s) is 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.
r •
Fill Materials and Placement
Clean on-site soils or approved imported materials may be used as fill material. Materials within 3 feet
of groundwater may require significant moisture conditioning prior to reuse as engineered fill.
Imported soils (if required) should conform to the following:
i . Percent fines by weight
Gradation (ASTM C1361
o- 3" 100
No. 4 Sieve 70-100
No. 200 Sieve 35 (max)
• Liquid Limit 30 (max)
• Plasticity Index 15 (max)
• R-Value 20 (min)
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. Recommended
compaction criteria for engineered fill materials is 95% of maximum dry density as determined by the
standard Proctor method ASTM D698.
On-site and imported sand soils should be compacted within a moisture content range of 4 percent
below to 2 percent above optimum unless modified by the project geotechnical engineer.
7
Geotechnical Engineering Report
Cattail Creek Pavement Design
Terracon Project No. 21045034 Terracon
Excavation and Trench Construction
Excavations into the on-site soils will encounter a variety of conditions, including caving soils and
possibly groundwater. 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.
The soils to be penetrated by the proposed excavations may vary significantly across the site. The
preliminary soil 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.
As a safety measure, it is recommended that all vehicles and soil piles be kept to a minimum lateral
distance from the crest of the slope equal to no less than the slope height. The exposed slope face
should be protected against the elements.
Additional Design and Construction Considerations
Underground Utility Systems
All piping should be adequately bedded for proper load distribution. It is suggested that clean, graded
gravel compacted to 75 percent of Relative Density ASTM D4253 be used as bedding. Where utilities
are excavated below groundwater, temporary dewatering will be required during excavation, pipe
placement and backfilling operations for proper construction. Utility trenches should be excavated on
safe and stable slopes in accordance with OSHA regulations as discussed above. Backfill should
consist of the on-site soils. The pipe backfill should be compacted to a minimum of 95 percent of
Standard Proctor Density ASTM D698.
All underground piping within or near the proposed structure should be designed with flexible
couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts in
grade beams should be oversized to accommodate differential movements.
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
8
Geotechnical Engineering Report
Cattail Creek Pavement Design
Terracon Project No. 21045034 Terracon
design and specifications. Terracon also should be retained to provide testing and observation
r ° during excavation, grading, and 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 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
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 outlined 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.
9
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Ditch
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M FIGURE I: SITE PLAN
LEGEND HE CATTAIL CREEK PAVEMENT THICKNESS DESIGN
NORTHEAST OF WELD COUNTY ROADS 29 AND 70
TEST BORINGS WELD COUNTY, COLORADO
Project Mngr. TGA Project No. 21045034
`LLLJJJ�' Designed By: lierracon Scale: 1. = 300
Checked TGA
1289 FIRST AVENUE
a 5/04/04
DED BY MESSNER By: TGA GREELEY, COLORADO 80631 Drawn By: TGA/AB
NOT INTEND D NFOR CONSTRUCTION PURPOSES. MODIFIED BY IERRACON. file\ Name: Cattail Creek Dmg Modified.dwg Figure No. 1
LOG OF BORING NO. B-1 Page 1 of 1
CLIENT
Messner Engineering
SITE Weld County Roads 29 and 70 PROJECT
Weld County,Colorado Cattail Creek Pavement Design
SAMPLES TESTS
DESCRIPTION m } w
U c >- re W Z H W~
n' H N o] W O 5 W IW- O W
N e. Wo: m OO 6 8 >- Z H
O Approx. Surface Elev.: 4784.5 ft o S) z 3 E m
TOPSOIL 4784
SILTY SAND, very loose to medium dense, SM 1 SS 10 9.7
moist to wet, brown(SM) -
•
1 _
SM 2 RS 3 17.0
5
i -
ss 4775 SP 3 SS 4 19.2
POORLY GRADED SAND WITH SILT, -SM
10 \occasional gravel, moist, brown(SP-SM) 4 10
END OF BORING
s
z
8
0-
The stratification lines represent the approximate boundary lines
between soil and rock types: in-situ,the transition may be gradual.
WATER LEVEL OBSERVATIONS, ft BORING STARTED 4-21-04
S WL Q 6 WD 5.5 1 AB BORING COMPLETED 4-21-04
WL Yir erracon RIG CME-55 FOREMAN JD
C4 WL AB checked after 24 hours. JOB# 21045034
LOG OF BORING NO. B-2 Page 1 of 1
CLIENT
Messner Engineering
SITE Weld County Roads 29 and 70 PROJECT
Weld County,Colorado Cattail Creek Pavement Design
SAMPLES TESTS
C0 O o
DESCRIPTION 2 a. I- z=
s = N w LLI> �i ML-1
Z zZ
re
w y o. wo: ?E.3
a0 K•- zr
O Approx. Surface Elev.: 4783.5 ft o 2 m 3 c) o x E y
":=05 TOPSOIL 4783
SILTY SAND loose to medium dense, SM 1 SS 11 7.3
moist to wet, brown to light brown(SM) -• SM 2 RS 7 17.4 106
5
1 �
t .
..f..8 • 4775.5 _
;. f WELL GRADED SAND WITH SILT
medium dense, wet, brown(SW-SM)• -
ti
SW 3 SS 19 14.2
• ti -SM
• 10 4773.5 10
END OF BORING
O
u
' U
I �
O The stratification lines represent the approximate boundary lines
$ between soil and rock types: in-situ,the transition may be gradual.
Any WATER LEVEL OBSERVATIONS, ft BORING STARTED 4-21-04
WL 7 WD 6.5 AB BORING COMPLETED 4-21-04
°_ WL 51 11 erracon RIG CME-55 FOREMAN JD
g WL AB checked after 24 hours. JOB# 21045034
LOG OF BORING NO. B-3 Page 1 of 1
CLIENT
Messner Engineering
SITE - Weld County Roads 29 and 70 PROJECT
Weld County,Colorado Cattail Creek Pavement Design
SAMPLES TESTS
_
a DESCRIPTION z
= y w > �w i z�
i a r CO CO w O wH O O w
rc F2 }
o Approx. Surface Elev.: 4782.0 ft o SI z m 3 c3i o 8 E',7)
TOPSOIL
4781.5
SILTY SAND loose to medium dense, SM 1 SS 16 7.8
moist to wet, brown to light brown (SM) -
•
SM 2 RS 4 13.7 106
5
.. ../C 8 4 4774 —
a WELL GRADED SAND WITH SILT
ti
medium dense,wet, brown (SW-SM) -
•
SW 3 SS 13 11.8
-SM
10 4772 10
END OF BORING
O
0
0
0
re
a.
re
The stratification lines represent the approximate boundary lines
between soil and rock types: In-situ,the transition may be gradual.
WATER LEVEL OBSERVVATIONS, ft BORING STARTED 4-21-04
'SS WL � 8 WD IT
` 7 5 �tlierracon BORING COMPLETED 4-21-04
WL
RIG CME-55 FOREMAN JD
WL AB checked after 24 hours. JOB# 21045034
U.S.SIEVE OPENING IN INCHES I U.S.SIEVE NUMBERS I HYDROMETER
4 3 2 1.5 1 3/4 1/2;{ 3 4 6 810 1416 20 30 40 50 80 100140200
100 I I I I I . 11 I 11
95
90
85
80
75
70 - -
i
65
t _
2 6o
>- 555 _
o
re
2 50 J
I— 45
U 40
W
I a
35
30 _
25
20
15
10
5
0
100 10 1 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
COBBLES GRAVEL SAND SILT OR CLAY
coarse I fine coarse I medium I fine
Specimen Identification Classification LL PL PI Cc Cu
• B-2 0.5ft SILTY SAND(SM) 22 19 3
Specimen Identification D100 D60 D30 D10 %Gravel %Sand %Silt I %Clay
• B-2 0.5ft 9.5 0.11 1.0 60.8 38.2
z
8
a.
GRAIN SIZE DISTRIBUTION
lierr acon Project: Cattail Creek Pavement Design
z
°' Site: Weld County Roads 29 and 70 Weld County, Colorado
Job#: 21045034
0 Date: 5-4-04
-2 _ - -
-1
1 `!
( 2
a \\\
4 r -
5 _ t_ -- •
6
7 __ r
8
0.01 0.1 1 10
PRESSURE,KSF
Specimen Identification Classification Yd, pcf WC,%
o • B-2 4.0ft SILTY SAND(SM) 106 17
0
Notes: Water added at 0.5 ksf.
CONSOLIDATION TEST
Project: Cattail Creek Pavement Design
1 brracon Site: Weld County Roads 29 and 70 Weld County,Colorado
8 8 Job#: 21045034
0 Date: 5-4-04
GENERAL NOTES
DRILLING&SAMPLING SYMBOLS:
SS: Split Spoon-1-'/8"I.D.,2"O.D.,unless otherwise noted HS: Hollow Stem Auger
ST: Thin-Walled Tube-2"O.D.,unless otherwise noted PA: Power Auger
{ RS: Ring Sampler-2.42"I.D.,3"O.D.,unless otherwise noted HA: Hand Auger
DB: Diamond Bit Coring-4",N, B RB: Rock Bit
BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary
.
The number of blows required to advance a standard 2-inch O.D. split-spoon sampler (SS) the last 12 inches of the total 18-inch
penetration with a 140-pound hammer falling 30 inches is considered the"Standard Penetration"or"N-value".
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WATER LEVEL MEASUREMENT SYMBOLS:
- WL: Water Level WS: While Sampling
WCI: Wet Cave in WD: While Drilling
DCI: Dry Cave in BCR: Before Casing Removal
AB: After Boring ACR: After Casing Removal
Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other
- times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater. In
low permeability soils,the accurate determination of groundwater levels may not be possible with only short-term observations.
DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils have
more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine
Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are
plastic,and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be
added according to the relative proportions based on grain size. In addition to gradation,coarse-grained soils are defined on the basis
of their in-place relative density and fine-grained soils on the basis of their consistency.
CONSISTENCY OF FINE-GRAINED SOILS RELATIVE DENSITY OF COARSE-GRAINED SOILS
Standard
Unconfined Penetration or Standard Penetration
Compressive N-value(SS) or N-value(SS}
Strength,Qu.psf Blows/Ft Consistency Blows/Ft Relative Density
<500 <2 Very Soft 0—3 Very Loose
500 - 1,000 2-3 Soft 4—9 Loose
1,001 - 2,000 4-6 Medium Stiff 10—29 Medium Dense
2,001 - 4,000 7-12 Stiff 30-49 Dense
4,001 - 8,000 13-26 Very Stiff 50+ Very Dense
8,000+ 26+ Hard
RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY
Descriptive Term(s)of other Percent of Mahar Component
constituents Dry Weight of Sample Particle Size
Trace <15 Boulders Over 12 in.(300mm)
With 15-29 Cobbles 12 in.to 3 in.(300mm to 75 mm)
Modifier >30 Gravel 3 in.to#4 sieve(75mm to 4.75 mm)
Sand #4 to#200 sieve(4.75mm to 0.075mm)
RELATIVE PROPORTIONS OF FINES Silt or Clay Passing#200 Sieve(0.075mm)
Descriptive Term(s)of other Percent of PLASTICITY DESCRIPTION
constituents Dry Weight
Term Plasticity Index
Trace <5 Non-plastic 0
With 5-12 Low 1-10
Modifiers > 12 Medium 11-30
High 30+
llerracon _
Form 108-9-00
UNIFIED SOIL CLASSIFICATION SYSTEM
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests" Soil Classification
Group
Symbol Group Name•
Coarse Grained Soils Gravels Clean Gravels Cu z 4 and I s Cc s 3` GW Well-graded gravel°
More than 50%retained More than 50%of coarse Less than 5%fines` Cu<4 and/or 1>Cc>3` GP Poorly graded gravel`
fraction retained on
on No.200 sieve No.4 sieve Gravels with Fines Fines classify as ML or MH GM Silty graven"
More than 12%fines` Fines classify as CL or CH GC Clayey gravel`°"
Sands Clean Sands Cu z 6 and 1 5 Cc s 3` SW Well-graded sand'
50%or more of coarse Less than 5%fines° Cu<6 and/or 1>Cc>3` SP Poorly graded sand'
fraction passes
No.4 sieve Sands with Fines Fines classify as ML or MH SM Silty sand"'
More than 12%fines° Fines Classify as CL or CH SC Clayey sand"'
Fine-Grained Soils Silts and Clays inorganic PI>7 and plots on or above"A"line' CL Lean Gay"
' - 50%or more passes the Liquid limit less than 50 PI<4 or plots below"A"line' ML Silt"
No.200 sieve
organic Liquid limit-oven dried Organic clay"""
<0.75 OL
Liquid limit-not dried Organic siltco"°
Silts and Clays Inorganic PI plots on or above"A"line CH Fat clay"
Liquid limit 50 or more
PI lots below"A"line MH Elastic Silt'"
organic Liquid limit-oven dried <0.75 OH Organic Gayr"
Liquid limit-not dried Organic silt- "40
Highly organic soils Primarily organic matter,dark in color,and organic odor PT .Peat
"Based on the material passing the 3-in.(75-mm)sieve If fines are organic,add"with organic fines"to group name.
B If field sample contained cobbles or boulders,or both,add"with cobbles ' If soil contains z 15%gravel,add"with gravel"to group name.
or boulders,or both"to group name. J If Atterberg limits plot in shaded area,soil is a CL-ML,silty clay.
°Gravels with 5 to 12%fines require dual symbols: GW-GM well-graded l<lf soil contains 15 to 29%plus No.200,add"with sand'or"with
gravel with silt,GW-GC well-graded gravel with Gay,GP-GM poorly gravel,"whichever is predominant.
graded gravel with silt,GP-GC poorly graded gravel with clay. L0 ° If soil contains z 30%plus No.200 predominantly sand,add
Sands with 5 to 12%fines require dual symbols: SW-SM well-graded "sandy to group name.
sand with silt,SW-SC well-graded sand with clay,SP-SM poorly graded
sand with silt,SP-SC poorly graded sand with clay M If soil contains z 30%plus No.200,predominantly gravel,
x
add"gravelly to group name.
ECU=DedD10 Cc= (D90) "PI z 4 and plots on or above"A"line.
Die X Doe ° PI<4 or plots below"A"line.
Pit soil contains z 15%sand,add"with sand"to group name. PPI plots on or above"A"line.
elf fines classify as CL-ML,use dual symbol CC-GM,or SC-SM. ° PI plots below"A"line.
60 i I
For classification of fine-grained
soils and fine-grained fraction "
50 —of coarse-grained soils ;fie - ce
Equation of"A"-line Al,{" e
014• Il Horizontal at PI=4 to LL=25.5. J `T
X 40 -- then PI-0.73(LL 20) .__-._.. .,r_�._ O __.__. .....
O Equation of"U"-line ,r°v
? Vertical at LL=16 to PI=7, fJ
30 — then P1=0.9(LL-8)
U , O�
w °t 20 Gp / am
a MH or OH
10
7
a ML or OL
° I I
0 10 18 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT(LL)
1 lerracon _
_ ,Form 111-698
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