HomeMy WebLinkAboutBID - 5361 HOWES STREET OUTALL PHASE 1 AND 2 (3)ENGINEERING REPORT
CITY OF FORT COLLINS STORMWATER UTILITIES
PROPOSED HOWES STREET OUTFALL
FORT COLLINS, COLORADO
PROJECT NO. 20985231
FEBRUARY 10, 1999
Prepared for.
CITY OF FORT COLLINS STORMWATER UTILITIES
P. 0. BOX 580
FORT COLLINS, COLORADO 80522
ATTN: MR. JAY ROSE
Prepared by.
Terracon
301 North Howes Street
Fort Collins, Colorado 80521
0
Geotechnical Engine
City of Fort Collins S
Terracon Project No.
conditions at the time of
locations Groundwater
conditions
Report
rater Utilities
5231
Terracon
field exploration, and may not be indicative of other times, or at other
els can be expected to fluctuate with varying seasonal and weather
Based upon review of U S Geological Survey maps (Hillier, et at, 1983), regional groundwater
Is expected to be encountered in unconsolidated alluvial deposits on the site, at depths ranging
from 5 to 20 feet below the existing ground surface at the project site
The possibility of groundwater fluctuations should be considered when developing design and
construction plans for the protect Fluctuations In groundwater levels can best be determined by
Implementation of a groundwater monitoring plan Such a plan would Include Installation of
groundwater monitoring wells, and periodic measurement of groundwater levels over a sufficient
penod of time
ENGINEERING ANALYSES AND RECOMMENDATIONS
Geotechnical
The site appears suitable for the proposed construction from a geotechnlcal engineering point of
view
The following foundation systems were evaluated for use on the site
• spread footings and/orlgrade beams bearing on undisturbed soils or structural fill
Slab -on -grade construction Is considered acceptable for use, provided that design and
construction recommendations are followed
Foundation Systems
Due to the presence of low swelling subsurface sods on the site, spread footing foundations
bearing upon undisturbed Isubsolls and/or engineered fill are recommended for support for the
proposed box culvert structures Footings may be designed for a maximum bearing pressure of
2000 psf The design beanng pressure applies to dead loads plus design live load conditions
2 Hillier, Donald E , Schneider,
Boulder -,Fort Collins -Greeley A
855-1
I A, Jr, and Hutchinson, E Carter, 1983, Depth to Water Table (1979) In the
Front Range Urban Corridor, Colorado, United States Geological Survey, Map I-
5
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Geotechnical Engineering Report
City of Fort Collins Stormwater Utilities
Terracon Project No. 20985231
Terracon
The design bearing pressure may be increased by one-third when considering total loads that
include wind or seismic conditions It is recommended the bottom of the box culvert stab and
foundations are placed a minimum of two (2) feet above the weathered bedrock stratum Over -
excavation and replacement with on -site overburden sods may be required to achieve this
recommendation in the a
Exterior footings should
protection and to provide
grade for perimeter footir
Footings should be prop
the basis of equal total s
dead -load pressure will
settlement resulting from
or less Differential sel
settlement Additional fo
foundation sods,
construction
Foundation walls should
by differential foundation
masonry walls is recomm
Foundation excavations
encountered differ sic
recommendations will be
Box Culvert
vicinity of Test Boring No 6
placed a minimum of 30 inches below finished grade for frost
inement for the bearing sods Finished grade is the lowest adjacent
oned to reduce differential foundation movement Proportioning on
ement is recommended, however, proportioning to relative constant
o reduce differential settlement between adjacent footings Total
assumed structural loads is estimated to be on the order of 3/4 inch
vent should be on the order of 1/2 to 3/4 of the estimated total
cation movements could occur if water from any source infiltrates the
proper drainage should be provided in the final design and during
reinforced as necessary to reduce the potential for distress caused
ovement The use of joints at openings or other discontinuities in
be observed by the geotechnical engineer If the sod conditions
tly from those presented in this report, supplemental
— Dewatering
Groundwater was encountered on the site at approximate depths of 4 to 13 '/z feet below
existing grades The box culvert construction is considered feasible on the site provided a
dewatenng system is installed parallel to the box culvert alignment and empties into the water
quality pond in Lee Martinez Park
To reduce the potential
a dewaterng system is
groundwater to enter the lower portion of the structure, installation of
;ommended The dewatenng system should, at a minimum, include
2
Terracon
Geotechnical Engineering Report
City of Fort Collins Stormwater Utilities
Terracon Project No. 20985231
an underslab gravel drat age layer sloped to an exterior perimeter drainage system running
parallel to the box culvert alignment
The drainage system should consist of a properly sized perforated pipe, embedded in free -
draining gravel, placed in a trench at least 12-inches in width. Gravel should extend a minimum
of 3-inches beneath the bottom of the pipe and one (1) foot above the bottom of the box culvert
slab The drainage system should be sloped at a steeper grade than the box culvert
The underslab drainage
gravel meeting the specii
pipes should be provided
drainage system
Should the box culvert
consideration should be
hydrostatic forces Use
recommended
Lateral Earth Pressures
For sods above any
unrestrained foundation
should consist of a minimum 6-inch thickness of free -draining
s of ASTM C33, Size No 57 or 67 Cross -connecting drainage
ith the slab at 40 intervals, and should discharge to the perimeter
constructed to any significant depth below groundwater level,
en to including vertical drainage against foundation walls to reduce
drainage media discharging to the foundation dewatenng system is
water surface, recommended equivalent fluid pressures for
nts are
• Active
Cohesionless sod backfill (on -site sands)
• Passive
soil backfill (on -site sands)
• Coefficientlof Base Friction
35 psf/ft
375 psf/ft
035
Where the design includes restrained elements, the following equivalent fluid pressures are
recommended
• At rest
sod backfill (on -site sand)
7
50 psf/ft
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Geotechnical Engine
City of Fort Collins S
Terracon Project No.
Fill against grade beam
Earthwork High plastic
Compaction of each lift
or other lightweight coml
which could result in wall
Seismic
Report
eater Utilities
Terracon
and retaining walls should be compacted to densities specified in
clay soils should not be used as backfill against retaining walls
lacent to walls should be accomplished with hand -operated tampers
;tors Overcompaction may cause excessive lateral earth pressures,
The project site is located in Seismic Risk Zone I of the Seismic Zone Map of the United States
as indicated by the 1997 Uniform Building Code Based upon the nature of the subsurface
materials, a sod profile type '� should be used for the design of structures for the proposed
project (1997 Uniform Building Code, Table No 16-J)
Box Culvert Slab Desion and Construction
Some differential movement of a box culvert slab -on -grade floor system is possible should the
subgrade sods become elevated in moisture content To reduce potential slab movements, the
subgrade soils should be prepared as outlined in the earthwork section of this report
For structural design of concrete slabs -on -grade, a modulus of subgrade reaction of 150 pounds
per cubic inch (pa) may be used for floors supported on existing sods
Additional floor slab
• Control j
cracking
• Interior
• In areas
gravel sl
• Floor
and construction recommendations are as follows
should be provided in slabs to control the location and extent of
ich backfill placed beneath slabs should be compacted in
with recommended specifications outlined below
acted to normal loading, a minimum 4-inch layer of clean -graded
be placed beneath the box culvert.
should not be constructed on frozen subgrade
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Geotechnical Engineering Report
City of Fort Collins Stormwater Utilities
Terracon Project No. 20985231
Terracon
• Other design and construction considerations, as outlined in the ACI Design
Manual, Section 302 1R are recommended.
Pavement Design and
Design of pavements for the protect have been based on the procedures outlined in the 1986
Guideline for Design of Pavement Structures by the American Association of State Highway and
Transportation Officials (i SHTO) Areas within proposed pavements on the site will be divided
into two categories based upon anticipated traffic and usage
Traffic criteria provided 1
loads (EAL's) of 10 for a
and 86 for Cheery Street
this report were discus_
Department
Local drainage characters;
good depending upon loc
characteristics are consic
approximate duration of s
of 0 90 when applying the
r pavement thickness designs include single 18-kip equivalent axle
omobile parking area, and 70 for Howes Street, 73 for Maple Street,
These values and the pavement thickness design criteria provided in
Bd with and approved by the City of Fort Collins Engineering
of proposed pavements areas are considered for vary from fair to
i on the site For purposes of this design analysis, fair drainage
I to control the design These characteristics, coupled with the
ated subgrade conditions, results in a design drainage coefficient
;HTO criteria for design
Street'; ",;;
;Category-
:18 kipT
`-''Reliability;`
;,`Iriibal;.
'Terrnirial
Structuril"
µti
;jTraffic;
N'ESAL,3'�',
"
,x" %°<,
YServicez'
eSeryice=_
Jlumtie�",
,1ESAL,
: Value
=r�"`
�l:il.i
�
�kk��ii
.`abili
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'�
_
d.4 �ii
Howes
Collector
70
511,000
90
42
25
267
Street
Maple
Collector
73
532,900
90
42
25
269
Street
Cherry
Collector
86
6271800
90
42
25
276
Street
r
Geotechnical Engine
City of Fort Collins S
Terracon Project No.
Using the correlated de
other factors, the above
the basis of the 1986 AP
In addition to the flexib
completed, based upon
evaluation of the Moduli
of the concrete, and o
subgrade soil was dete
rupture of 650 psi (wc
pavement thicknesses f
design equation
Report
rater Utilities
Terracon
R-value of 18, appropriate ESAtJday, environmental cntena and
.tural numbers (SN) of the pavement sections were determined on
design equation
pavement design analyses, a rigid pavement design analysis was
4SHTO design procedures Rigid pavement design is based on an
of Subgrade Reaction of the soils (K-value), the Modulus of Rupture
:r factors previously outlined The design K-value of 110 for the
uned by correlation to the laboratory tests results A modulus of
ng stress 488 psi) was used for pavement concrete The rigid
each traffic category were determined on the basis of the AASHTO
Traffic Area
�,Altemativ®�
., ,Recomrnen`ded Pavement Thicknesses (inches) ,, , t,
Asphalt
Concrete',
Surface ,
Aggregate
"Base Course
w-
Plant -Mixed =
Bituminous � �;.
Base'`
3Portiand.,
�,- Cement I' „
' Concrete �'
,
_ , Total',,`
Automobile
A
3
6
9
Parking
B
2
3
5
Areas
C
6
6
Maple Street
A
4
9
13
And
B
3
4
7
Howes Street
C
I
7
7
Cherry
A
4
10
14
B
3
5
8
Street
C
7
7
Each alternative should be
conditions Aggregate ba!
gravel, which meets strict
Colorado Department of T
base course Aggregate
should be compacted to a
investigated with respect to current material availability and economic
,e course (if used on the site) should consist of a blend of sand and
specifications for quality and gradation Use of materials meeting
ransportation (CDOT) Class 5 or 6 specifications is recommended for
base course should be placed in lifts not exceeding six inches and
minimum of 95% Standard Proctor Density (ASTM D698)
ire
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Geotechnical Engine
City of Fort Collins S
Terracon Project No.
Asphalt concrete and/or I
of aggregate, filler and ad
base and/or asphalt cor
properties, optimum asp]
temperatures Aggregate
should meet particular g
Grading C or CX specr
Colorado Department of -,
mixed bituminous base c,
their adequacy Asphaf
compacted to a minimum
Where rigid pavements
with the following mirnn
Report
water Utilities
Terracon
ant -mixed bituminous base course should be composed of a mixture
litives, if required, and approved bituminous material The bituminous
:rete should conform to approved mix designs stating the Hveem
alt content, job mix formula and recommended mixing and placing
used in plant -mixed bituminous base course andlor asphalt concrete
adations Material meeting Colorado Department of Transportation
cation is recommended for asphalt concrete Aggregate meeting
-ansportation Grading G or C specifications is recommended for plant-
urse Mix designs should be submitted prior to construction to venfy
material should be placed in maximum 3-inch lifts and should be
)f 95% Hveem density (ASTM D1560) (ASTM D1561)
used, the concrete should be obtained from an approved mix design
properties
• Modulus of Rupture @ 28 days
600 psi minimum
• Strength Requirements
ASTM C94
• Minimum Cement Content
• Cement Type
6 0 sacks/cu yd
Type I Portland
• Entrained Air Content
4 to 8%
• Concrete Aggregate
ASTM C33 and CDOT Section 703
• Aggregate Size
1 inch maximum
• Maximum Water Content
0 49 Ibflb of cement
• Maximum Allowable Slump
4 inches
Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 minutes
from the time the water is added to the mix Other specifications outlined by the Colorado
Department of Transportation should be followed
Longitudinal and transverse joints should be provided as needed in concrete pavements for
expansion/contraction and isolation The location and extent of joints should be based upon the
final pavement geometry and should be placed (in feet) at roughly twice the slab thickness (in
11
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Geotechnical Engineering Report
City of Fort Collins Stoimwater Utilities
Terracon Project No. 26985231
Terracon
inches) on center in either direction Sawed joints should be cut within 24-hours of concrete
placement, and should be a minimum of 25% of slab thickness plus 114 inch All joints should be
sealed to prevent entry of, foreign material and dowelled where necessary for load transfer
Preventative maintenance should be planned and provided for through an on -going pavement
management program in order to enhance future pavement performance Preventative
maintenance activities are intended to slow the rate of pavement deterioration, and to preserve
the pavement investment)
Preventative maintenance consists of both localized maintenance (e g crack sealing and
patching) and global maintenance (e g surface sealing) Preventative maintenance is usually
the first priority when implementing a planned pavement maintenance program and provides the
highest return on investment for pavements
Recommended prever
based upon type and s
additional engineering
preventative maintenar
Earthwork
General
The following F
preparation and
maintenance policies for asphalt and jointed concrete pavements,
r of distress, are provided Prior to implementing any maintenance,
rvation is recommended to determine the type and extent of
recommendations for site preparation, excavation, subgrade
nt of engineered fills on the project
All earthwork on 'the protect should be observed and evaluated by Terracon The
evaluation of earthwork should include observation and testing of engineered fill,
subgrade preparation, foundation bearing sods, and other geotechnical conditions
exposed during the construction of the project
Site Preparation
Strip and remove'I existing pavement and fill materials, vegetation, debris, and other
deleterious materials from proposed box culvert structure and pavement areas All
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Geotechnical Engine
City of Fort Collins S
Terracon Project No.
Report
later Utilities
Terracon
exposed surfaces (should be free of mounds and depressions, which could prevent
uniform compaction
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 building structures.
All exposed areas which will receive fill, once properly cleared and benched where
necessary, should be scanfied to a minimum depth of eight inches, conditioned to near
optimum moisture content, and compacted
It is anticipated that excavations for the proposed construction can be accomplished with
conventional earthmoving equipment 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
Based upon the subsurface conditions determined from the geotechncal exploration,
subgrade sods exposed during construction are anticipated to be relatively stable
However, the statidity of the subgrade may be affected by precipitation, repetitive
construction traffic or other factors If unstable conditions develop, workability may be
improved by scanfying and drying Overexcavation of wet zones and replacement with
granular materials may be necessary Use of lime, fly ash, kiln dust, cement or
geotextdes could also be considered as a stabilization technique Laboratory evaluation
is recommended to determine the effect of chemical stabilization on subgrade sods prior
to construction. Lightweight excavation equipment may be required to reduce subgrade
pumping
Subgrade
Subgrade soils
moisture condit
content and co
construction
Fill Materials and
Clean on -site sods
ath the culvert slab, and beneath pavements should be scanfied,
and compacted to a minimum depth of eight inches The moisture
ion of subgrade sods should be maintained until slab or pavement
approved imported materials may be used as fill material
13
Terracon
Geotechnical Engineering Report
City of Fort Collins Stormwater Utilities
Terracon Project No. 20985231
On -site soils are sluitable for use as compacted fill beneath interior or exterior floor slabs
Imported sods (d' required) should conform to the following
Percent fines by weight
(ASTM C136)
100
3".. 70-100
No 4 Sieve 50-100
No, 200 Sieve 65 (max)
• Liquid Limit .
30 (max)
• Plasticity Index
.15 (max)
• Group Index.
10 (max)
Engineered fill should be placed and compacted in horizontal lifts, using equipment and
procedures that wl11 produce recommended moisture contents and densities throughout
the lift. Recommended compactmn cntena for engineered fill materials are as follows
Minimum Percent
Material (ASTM D698)
Scanfied sl bgrade soils 95
On -site and imported fill soils
Beneath foundations 95
Beneath slabs 95
Beneath pavements 95
Miscellaneous backfill (non-structural areas) 90
On -site clayey sands or imported clay sods should be compacted within a moisture
content range of 2 percent below, to 2 percent above optimum Imported granular soils
14
February 10, 1999
City of Fort Collins —S
P O lBox 580
Fort Collins, Colorado
Attn Mr Jay Rose
Re: Geotechnical
City of Fort C
Proposed Ho
Fort Collins, I
Terracon Pro
Terra Icon has complel
Street Outfall Box Cu
from LaPorte Avenue
performed in general
1998,
reff3rarmn
301 N Howes • PO Box 503
Fan Collins Colorado 80521 0503
1970) 494-0359 Fax (970) 484 0454
Utilities
ineering Report
s Stormwater Utilities
Street Outfall
No. 20985231
a geotechnical engineering exploration for the proposed Howes
t Project to be constructed between Mason and Howes Streets,
Lee Martinez Park in Fort Collins, Colorado This study was
Irdance with our proposal number D2098287 dated December 10,
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 foundations, pavements, and other earth connected phases of
this project are attached
The subsurface soils at the site consisted of pavement layers, silty clayey sand with gravel
fill and sandy lean clay underlain by silty sand with gravel The clay and sand strata are
underlain by the bedrocks encountered at approximate depths of 61/ to 13 feet below existing
site grades in all nine (9) test borings Groundwater was encountered at approximate
depths of 4 to 131/2 feet below existing site grades The results of field exploration and
laboratory testing completed for this study indicate that the sods at the site have low
expani sive potential The soils at anticipated foundation bearing depth have low to moderate
load bearing capability The subgrade soil beneath existing street cut sections exhibits
moderate subgrade strength characteristics
Based on the subsurface conditions encountered and the type of construction proposed, it is
recommended the box culvert structure be supported by conventional -type spread footings
Arizona ■ Arkansas ® Colorado 6 Idaho ® Illinois ■ Iowa ! Kansas ® Minnesota ■ Mrseoun ® Montana
Nebraska ® Nevada ■ New Mexico ■ North Dakota ■ Oklahoma i Tennessee ■ Texas ■ Utah 13 Wisconsin ■ Wyoming
Quality Engineering Since 1965
Terracon
Geotechnical Engineering Report
City of Fort Collins Stormwater Utilities
Terracon Project No. 20985231
and/or on -site sands should be compacted within a moisture range of 3 percent below to
3 percent above optimum unless modified by the project geotechnical engineer
Excavation and Trench Construction
Excavations into the on -site sods will encounter a variety of conditions Excavations into
the clays can be expected to stand on relatively steep temporary slopes during
construction However, caving soils and groundwater may also be encountered 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 sods to be penetrated by the proposed excavations may vary significantly across the
site The preliminary sod 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 drstnbubon 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 dewatenng will
be required during excavation, pipe placement and backfillrng 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
15
Terracon
Geotechnical Engineering Report
City of Fort Collins Stormuvater Utilities
Terracon Project No. 209855231
on -site soils or imported material approved by the geotechnical engineer The pipe
backfill should be compacted to a minimum of 95 percent of Standard Proctor Density
ASTM D698.
Corrosion Protection
Results of soluble sulfate testing indicate that ASTM Type I Portland cement is suitable
for all concrete on and below grade However, if there is no, or minimal cost differential,
use of ASTM Type 11 Portland cement is recommended for additional sulfate resistance
of construction concrete Foundation concrete should be designed in accordance with
the provisions of the ACI Design Manual, Section 318, Chapter 4
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 testing and
observation during excavation, grading, foundation 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 vanations, which may occur between borings or across
the site The nature and extent of such vanations may not become evident until construction 11
variations appear, i1 will be necessary to reevaluate the recommendations of this report
The scope of services for this project does not include either specifically or by implication any
environmental assessment of the site or identification of contaminated or hazardous materials or
conditions If the owner is concerned about the potential for such contamination, 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. In the
event that changes in the nature, design, or location of the project as outlined in this report, are
16
Terracon
Geotechnical Engineering Report
City of Fort Collins; Stormwater Utilities
Terracon Project No. 20985231
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
17
NO
a
HOBES
WTE FALL
ALIGNMENT
NO j
i
MASON STREET
a
a
U
NO d
NO 5 Nn E
PROPOSED
P..__
DUAL
NO 1
\� \N0s
z
DIAGRAM IS FOR GENERAL LOCATION ONLY,
AND IS NOT INTENDED FOR CCNSTRUCUON PURPOSES
FIGURE I: SITE MAP
CITY OF FORT COLLINS, HOWES STREET OUTFALL
HOWES STREET
FORT COLLINS, COLORADO
Project Mnpr DAR
Irerrac®Y ^ ■
SDI N. Howes Sisas*F
Fowl COI.Los, COMADO ON21
Pmpel No 20981
Designed By
R°M• 1".
Checked � DAR
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DAR
Oravn Br
Flle Nama• 23 SSLD
Flgu HHo l
i
LOG OF TEST BORING NO. 1
Page 1 of 1
CLIENT
ARCHITECT / ENGINEER
City of Fort Collins Stormwater
Icon Engineering/Bates Engineering
SITE LaPorte Avenue to Lee Martinez Park
PROJECT
Fort Collins, Colorado
Howes Street Outfall
SAMPLES
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17
FILL MATERIAL. _Sandy Lean
Clay with Gravel
3 0 Tan, gray, rust, moist 49790
5
27,8,44
CLAYEYSAND
50 Brown' tact' rust, moist, medium 4977 0
dense
SC
2
SS
12"
10
18
SILTY SAND with GRAVEL _
Tan, gray, moist to wet, mediurG
dense to dense
SM
3
SS
6"
50/0 5
7
I
10
120 49700
SWELL
PRESSUR
@ 14 0'
WEATHERED SZ
13 5 C,1 AYSTONEIS[ T TONE_ —4968 5
147 BEDROCK 4967 3
Tan, gray, olive, moist, moderately
4
SS
7"5010
7
17
hard
400 PSF
CLAYSTONE/SiLTSTO_
BEDROCK
an, gray, olive, moist, hard
BOTTOM OF BORING
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES
BETWEEN SOIL AND ROCK TYPES- IN -SITU, THE TRANSITION MAY BE GRADUAL
WATER LEVEL OBSERVATIONS
BORING STARTED 1-7-99
W D
=
BORING COMPLETED 1-7-99
LWLU0'
lrRIG
CME-55 FOREMANRTS
tial Water Level Reading
APPROVED DAR JOB a 20985231
LOG OF TEST BORING NO. 2 Page 1 of 1
CLIENT
City of Fort Collins Stormwater
ARCHITECT/ENGINEER
Icon Engineering/Bates Engineering
SITE LaPorte Avenue to Lee Martina. Park
Fort Collins, Colorado i
PROJECT
Howes Street Outfall
0
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LD
DEKRIPTION
Approx. Surface Elev,: 4982.0 ft.
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FILL MATERIAL silty Sand with
Gravel
Tan, gray, rust, moist
4 5 4977 5
5
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12"
14
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I
2
SS
12"
12
6
SILTY SAND with GRAVF_L _
Tan, gray, moist to wet, medium
dense to dense
4
13 0 4969 0
WEATHERED
CLAYSTONE/(iILTSTONE
BEDROCK
Tan, gray, Olive, moist, moderately
hard
180 49640
4
SS
12"
42
18
19 5-AYSTONE/SILISTONE - 4962 5
BED O K
Tan, gray. olive, moist, hard
BOTTOM OF BORING
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES
BETWEEN SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL
WATER LEVEL OBSERVATIONS
offm
�rr
BORING STARTED 1-7-99
WL
R 8 5' W D
Y
BORING COMPLETED 1-7-99
WL
RIG CME-SS
FOREMAN RTS
`A'L
Initial Water Level Reading
APPROVED DAR
I JOB s 20985231
LOG OF TEST BORING NO. 3 Page 1 of 1
CLIENT
ARCHITECT I ENGINEER
City of Fort Collins Stormwater
Icon Engineering/Bates Engineering
SITE LaPorte Avenue to Lee Martinez Park
PROJECT
Fort Collins, Colorado
Howes Street Outfall
SAMPLES
TESTS
Or
W
(13
r
O
Z
W
a-
}
F-
Ce
'>
o
U
W
X
W
Z�
' to
3
HO
0-J
trim
\
Ce
1-0
to
H
O
Z
H
w
YIL
W_u
oa
W
LL-
ZZ
COW
UWLL
ZF-tn
atnEL
H2N
o` se
HH'
=) to
cc,
HJ
Jn. N
LD
J
H
x
a
Cc
W
cD
DESCRIPTION
Approx. Surface Elev.: 4983.0 ft.
F-
2
ELU
W
o
m
N
to
VI
=0
03 ASPHALT (2") Parking Area 49927
0 6 BASE Cot IR:jp,(4") 49824
1
SS
12"
14
16
2 0 Silty Sand with Gravel 4981 0
FILL MATEFUAL—Sandy Lean,
Clay with Gravel
Tan, rust, moist
SM
SS
12"
6
4
SILTY SAND with .RAYEL ,_
5
Tan, gray, mmst to wet, medium
dense to dense
`
I
NV,NP 21
3
SS
12"
44
4
i
j
10
120 4971 0
WEATHERER
C AYSTONE/SILTSTONE 4
BFDROC
15 0 Tan, gray, olive, moist, moderately 49680
15
4
SS
7"
50/0 7
14
hard
i
i
BOTTOM OF BORING
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES
BETWEEN SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL
WATER LEVEL OBSERVATIONS
I
; RM
BORING STARTED 1-7-99
WL
13.5' w' D IT 9.5' AB
BORING COMPLETED 1-7-99
WL
� �
RIG CME-55
EOREMAN RTS
wL
Water checked 2 days A.B
APPROVED DAR
JOB # 20985231
LOG OF TEST BORING NO. 5
Page I of I
CLIENT
ARCHITECT / ENGINEER
City of Fort Collins StOrMwater
Icon Engineering/Bates Engineering
SITE LaPorte Avenue to Lee Martinez Park
PROJECT
Fort Collins, Colorado
Howes Street Outfall
SAMPLES
TESTS
\
>
HWm
CD
J
O
O
H
i-
O
=00
J
H
M
LL
H
W
HZ(U
H
DESCRIPTIONN
w
Z�
?
_
x
x
�
W
D.
ui
F
w
0
tHi
ZZ
❑~4
HH
0_
H
En
CO
W
O
3
to
O W
:Din i
Q
0_
U
U
F-O
1-4
YLL
UWIL
O¢"
it
LD
Approx. Surface Elev.: 4982.0 ft.
W
0
to
Z)
0
Z
}
r
W
it
a_J
U) CO
O
r
xU
OIL
ZF_(n
xU)(L
HJ
-JIL\
02 ASPHALT PAVE M ENT IT I 4981 8
0 5 PARKING AREA 4981 5
l
SS
12"
12
12
20 BASE COURSE W) 49800
Silty Sand wide Gravel
FILL MATERIAL• Sandy Lean
Clay with Gravel
SM
2
SS
9"
50/0.9
3
NV,NP,18
an, rust, moist
5
SILTY SAND with GRAVEL
Tan, gray, moist to wet, medium
dense to dense
3
SS
9"5010
9
2
10
12 5 4969 5
WEATHERED =
CLAYSTONE/SII,TSTONE
14 5 4967 5
7 BEDROCK
Tan, gray, olive, moist, moderately
hard
BOTTOM OF BORING
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE,BOUNDARY LINES
BETWEEN SOIL AND ROCK TYPES IN -SITU, THE TRANSITION MAY BE GRADUAL.
WATER LEVEL OBSERVATTONS
loom
BORING STARTED 1-7-99
W D
= 13.5' AB
COMPLETED 1-7-99
WL
fUzDRY
��80RING
RIG CME-55
FOREMAN RTS
WLWater
checked 2 days A B
APPROVED DAR
11013 a 20985231
LOG OF TEST BORING NO. 6 Page I of 1
CLIENT
City of Fort Collins Stormwater
ARCHITECT / ENGINEER
Icon Engineering/Bates Engineering
SITE LaPorte Avenue to Lee Martinez Park
Fort Collins, Colorado
PROJECT
Howes Street Outfall
O
J
H
x
CC
DESCRIPTION
Approx. Surface Elev.: 4980.5 ft,
H
m
1-
0_
o
O
in
N
to
U
SAMPLES
TESTS
m
W
m
L
z
W
a-
r'
w
O
U
X
LL
Z\
L to
3
HO
(ncc
m
to
H
�
H
w
❑
YLLL
oa
p
W
iHi -
ZZ
ow
UQ:LL
�fjd
J
J
=X
Ln
W Ln
WWLL
Lmi.a_a
0 8 ASPHALT (8") 4979 7
1 5 CHERRY STREET 49790
BASF O IRS . ()")
Silty Sand with Gravel
40 FILL MATERIAI—,�andy Lean 4976 5
Clay with Gravel
Tan, test, moist
5_7
10
IS
450
1
SS
12"
12
10
SM
2
SS
12"
22
3
SILTY SAND wuli GRAVEL '
6 5 Tan, gray, moist to wet, medium 49740
i dense to dense
WEATHERED
8 5 CLAYSTONE/SILTSTONE 49720
3
RS
12"
50
16
BEDROCK
Tan, gray, olive, moist, moderately
hard
CI AYSTON /SI I'STONE
BEDROCK
Tan, gray, olive, moist, hard
19 8 49607
BOTTOM OF BORING
4
SS
10"
50/0 8
10
5
SS
9"
5010 8
13
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES
BETWEEN SOIL AND ROCK TYPES: IN-S17U, THE TRANSITION MAY BE GRADUAL
WATER LEVEL OBSERVATIONS
err
BORING STARTED 1-7-99
L 7 DRY W D
x_
BORING COMPLETED 1-7-99
WL
RIG CMIE-55
FOREhtAN RTS
WL I Initial Water Level Reading
APPROVED DAR
JOB # 20985231
LOG OF TEST BORING NO. 7
Page 1 of 1
CLIENT
ARCHITECT I ENGINEER
City of Fort Collins Stormwater
Icon Engineering/Bates Engineering
SITE LaPorte Avenue to Lee Martinez Park
PROJECT
Fort Collins, Colorado
Howes Street Outfall
SAMPLES
TESTS
\
}
HWm
C7
J
F
m
Lt
H
W
HZN
H
DESCRIPTION
U.
>
W
z\
W
w
H�
oHtt
x
x
W
>
I In
o
zz
HH'
a_
H-
Il
In
U
m
=
W
a-
O
U
3
HO
In
H
}ti
ow
L)MU-
� In I
C3<C1
CY
cD
Approx. Surface Elev.: 4978.0 ft.
W
o
In
x
m
z
>
W
m
D- S
In In
O
z
IrU
oo-
ZH(n
TiIna-
HJ
-ia x
XXX
FILL MATERIAL. Sandy Lean
1
SS
12"
14
14
Clay with Gravel
2 0 Tan, rust, moist 49760
SILTY SAND
Tan, rust, moist, loose to medium
SM
2
ST
12"
7
103
dense
3
SS
12"
12
17
5
.
I
* Intermittent CLAYEY SAND
4
ST
12"
11
120
2460
lenses with depth
5
SS
12"
22
8
NV,NP,29
9 0 49690
10
SILTY SAND with GRAVEL
Tan, gray, moist to wet, medium
I
dense to dense
SM
135
49645
6
SS
9"
010 8
15
WEATHERED
14 8 4963 2
AYSTON /SILTSTON
BEDROCK
I
Tan, gray, olive, moist, moderately
hard
I
1
BOTTOM OF BORING
i
I
!
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES
BETWEEN SOIL AND ROCK TYPES IN -SITU, THE TRANSITION MAY BE GRADUAL
WATER LEVEL OBSERVATIONS
�! gnmoft
BORING STARTED 1-7-99
WL
g DRY W D
-T 14 O' Ai B
BORING COMPLETED 1-7-99
WL
�uam
RIG CM[E-55
FOREMAN RTS
WL
Water checked 2 days A.B.
APPROVED DAR
JOB a 20985231
Geotechnical Engine
Cityjof Fort Collins S
Terracon Project No.
Other design and con;
presented in the report
mg Report
rmwater Utilities
Terracon
recommendations, based upon geotechnical conditions, are
We appreciate being ofIservice 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,
TERRACON \\`wnwumuu,
A.kc
Prepared by
27712
avid A Richer, P E
' '�St.AL'E
Geotechnical Engineer "'o-nn,,,,,,,10
Reviewed by William J Attwooll, P E
Office Manager
Copies to Addressel (3)
Icon Engineering Inc (1) Mr Doug Williams
Bates Engineering (1) Mr Dave Woodward
LOG OF TEST BORING NO. 8 page 1 of 1
CLIENT
City of Fort Collins Stormwater
ARCHITECT I ENGINEER
Icon Engineering/Bates Engineering
SITE LaPorte Avenue to Lee Martinez Park'
Fort Collins, Colorado
PROTECT
Howes SI reet Outfall
0O
-1
H
x
a
¢
CD
DESCRIPTION
Approx. Surface Elev.: 4979.0 ft.
.-.
H
x
H
a
w
CD
J
m
'w
to
U
N
SAMPLES
TESTS
w
m
z
x
z
LLt
a
r
t
w
:
o
U
w
M
LL_
z
in
s
A
o.-j
U) CO
\
Of
H-
to
H
o
r
>
H
w
o
>-LL
WU
ca.
W
NHL i-
z z
ow
UXLL.
zi-m
xtna
Hwm
HZ0
❑ ~ *t '
Hi--,
Mtn t
O<rl
HJ
-j v
0 5 6" TOPSOIL 4978 5
SILTY SAND
Tau, rust, moist, loose to medium
dense
i
50 49740
dSM
5
10
15
23.4,33
i
1
SS
12"
6
10
2
SS
12"
5
15
SILTY CLAYEY SAND'
Tan, butt, olive moist to wet,
loose to medium dense
90 49700
SC-
3
SS
12"
19
19
SILTY SAND with GRAV L
Tan, gray, moist to wet, medium
dense to dense I
12 0 49670
SM
WEATHERED
CT-AYSTONE/SILTSTONE
15 0 BEDROCK 49640
Tan, gray, olive, moist, in derately
hard
4
SS
12"
24
17
CI .AYSTONE/SILTSTONF
B DRO K i
Tan, gray, rust, moist, hard
195 4959 5
BOTTOM OF BORING
i
I
I
i
i
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES
BETWEEN SOIL AND ROCK TYPES IN-SITU,I THE TRANSITION MAY BE GRADUAL
WATER LEVEL OBSERVATIONS i
IreffaC93n
I
BORING STARTED 1-7-99
�_ 9.�> W D
=_ I
BORING COMPLETED 1-7-99
lWL
WL
I
RIG CHE-55
FOREMAN RTS
k�VL
I Initial Water Level Reading
APPROVED DAR
IJOB# 20985231 1
LOG OF TEST BORING NO. 9 Page 1 of 1
CLIENT
ARCHITECT I ENGINEER
City of Fort Collins Stormwater
Icon Engineering/Bates Engineering
SITE LaPorte Avenue to Lee Martinez Park
PROJECT
Fort Collins, Colorado
Howes Street Outfall
SAMPLES
TESTS
r
z
a.
w
U
X
LL
Z\
r o
win
W
H
M
rY
H-i
w
aril
oa
❑
w
HLL �
ua:u-
Z)wNa
C3
H
OESCRIPTION
Approx. Surface Elev.: 4961.0 ft.
r
Q.0
wo
o
m
>
0 5 6" TOPSOIL 49605
SANDY LEAN CLAY
CL
1
SS
12"
9
10
Tan, rust, mots[ to wet, medium
stiff
3 5 4957 5
2
ST
12"
26 1
99
2130
3
SS
12"
13
23
SILTY SAND with GRAVEL.
Tan, gray, moist to wet, medium
5
dense to dense
I
i
SM
4
1 SS
12"
24
25
10
13 0 4948 0
15
WEATHERED
AYSTON /SIT TSTONF
5
SS
12"
50
15
ISO 4946 0
BEDROCK
Tan, gray, olive, moist, moderately
hard
�i
I
BOTTOM OF BORING
I
1
i
i
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES
BETWEEN SOIL AND ROCK TYPES IN-SITU,I THE TRANSITION MAY BE GRADUAL
WATER LEVEL OBSERVATIONS I
BORING STARTED 1-7-99
WL
4 4.5> W D
IT 4.0' 'A B
BORING COMPLETED 1-7-99
wLerr
RIGC1VIE-55
FOREMAN RTS
w'I
I Water checked 2 days A.B.
APPROVED DAR
11013 n 20985231
0
0
0
V
0
I
D
0
R
A
T
I
0
0
0
0
0
75
I
I
I
70
I
I
I
65
i
II
1
i
i
i
i
I
55
I
50
I
I
45
40
F-
i
i
I
I
0 1
__j
1 10
APPLIED PRESSURE, TSF
Bonng and depol (ft ) Classification DD MC %
• 6 180 WEATHERED CLAYSTONE/SILTSTONE 114 16
PROJECT Howes Street Outfall - LaPorte Avenue to Lee JOB NO 213985231
Martinez Park I DATE 1/27/99
CONSOLIDATION TEST
TERRACON
S
w
E
L
L
C
O
N
S
O
L
I
D
A
T
I
O
N
r
I
I t
I � \
I
2
I
3
I
4
I
5
i
6
I
7-
8-
0 1 I 1 0
I APPLIED PRESSURE, TSF
and
101 6 9.0 1 WEATHERED CLAYSTONE/SILTSTONE 1 114 1 16 1
I PROJECT Howes Street Outfall - LaPorte Avenue to Lee JOB NO 2UM231 I
Martina Park DATE 1/27/99
CONSOLIDATION TEST
TERRACON
0
0
0
V
0
1
D
0
R
A
T
u
0
0
0
0
7s
I
70
65
I \
60 I
i
I
I
55
i
50
I
45
I
40
0 1 1 1 10
APPLIED PRESSURE TSF
i
Bonng and depth (ft ) Classification I DD I MC %
101 9 3.0 1 SANDY LEAN CLAY (CL) 96 1 26
PROJECT Howes Street Outfall -LaPorte Avenue to LeeJOB NO 209852.51
Martinez Park I DATE 1/27199
CONSOLIDATION TEST
TERRACON
2
i
t
S 2
E
L
L
3
I
7 ,
4
C
O
N
s
O
L 5
t I
D
N 6
i
I
7
8
0 1 1 10
APPLIED PRESSURE TSF
Bonne and depdi (it) Classification DD MC%
*1 9 3.0 SANDY LEAN CLAY (CL) 96 26
PROJECT Howes Street Outfall - LaPorte Avenue to Lee JOB NO 20985231
Martinez Park I DA'I E 1/27/99
CONSOLIDATION TEST
TERRACON
No Text
7 301 NO HOWES STREET
P O BOXX 5, 503
Irerracon
FORT COLLINS, COLORADO 80521
(970) 484.0359 FAX (970) 484-0454
I
RESISTANCE
R-VALUE & EXPANSION
I
PRESSURE
OF COMPACTED SOIL
ASTM D-2844
CLIENT
City of Fort Collins Stormwater
PROJECT.
Howes Street Outfall - LaPorte Avenue to Lee Martinez Park
LOCATION.
Composite Sample Test Boring No 4 @ 0 5' - 4 0'
TERRACON NO.
20985231 CLASSIFICATION: Sandy Lean Clay with Gravel (CL)
SAMPLE DATA TEST RESULTS
TEST SPECIMEN NO. I 1 2 3
COMPACTION PRESSURE (PSI) 350 350 350
DENSITY (PCF) 1178 1159 1158
MOISTURE CONTENTI(%) 182 176 161
EXPANSION PRESSURE 000 000 000
HORIZONTAL PRESS , RE @ 160 PSI 148 132 105
SAMPLE HEIGHT (INCHES) 250 2 58 2 50
EXUDATION PRESSURE (PSI) 1193 2228 4654
CORRECTED R-VALUE 51 124 294
UNCORRECTED R-VALUE 51 124 294
R-VALUE @ 300 PSI Ei UDATION PRESSURE = 18
100
90
80
70
60
w
50
�
I
40
30
20
I
10
0
0 100
I 200 300 400 500 600 700 800
EXUDATION PRESSURE - PSI
DRILLING & SAMPLING SYMBOLS.
R Ring Barrell - 2 42" I,D , 3" O.D ,
SS Split Spoon - 1 " I D , 2" O D, L
ST Thin -Walled Tube - 2" 0 D, unle
PA • Power Auger
HA Hand Auger
DS Diamond Bit = 4", N, B
AS A S 1
Au
amp e
HS Hollow Stem Auger `
Penetration Test Blows per foot of a 140 pound hammer falling 30 inches on a 2-inch 0 D split spoon, except where
noted
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 Casting Removal
Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils,
the indicated levels may reflect the location of groundwater In low permeability sods, the accurate determination of
groundwater levels is not possible with only short term observations
DESCRIPTIVE SOIL CLASSIFICATION
Soil Classification is based on the Unified Sod Classification system and the ASTM Designations D-2487 and D-2488
Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve, they are described as boulders,
cobbles, gravel or sand Fine Grained Sods have less than 50% of their dry weight retained on a #200 sieve, they are
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 sods are defined on the basis of their relative in -place density and fine grained sods
on the basis of their consistency Example Lean clay with sand, trace gravel, stiff (CL), silty sand, trace gravel, medium
dense ISM)
DRILLING AND EXPLORATION
less otherwise noted
ss otherwise noted
otherwise noted
PS
WS
FT
RB
BS
PM
DC
WB
Piston Sample
Wash Sample
Fish Tad Brt
Rock Bit
Bulk Sample
Pressure Meter
Dutch Cone
Wash Bore
CONSISTENCY OF FINE-GRAINED SOILS.
RELATIVE DENSITY OF
Unconfined Compressive
I
COARSE -GRAINED
SOILS:
Strength, Qu, psf
Consistency
N-Blows/ft.
Relative Density
< 500
Very Soft
0-3
Very Loose
500- 1,000
Soft
4-9
Loose
1,001 - 2,000
Medium
10-29
Medium Dense
2,001 - 4,000
Stiff
30-49
Dense
4,001 - 8,000
Very Stiff
50-80
Very Dense
8,001-16,000
Very Hard
80+
Extremely Dense
RELATIVE PROPORTIONS OF
SAND AND GRAVELI
GRAIN SIZE TERMINOLOGY
Descriptive Term(s)
IMajor
Component
(of Components Also
Percent of
of Sample
Size Range
Present in Sample)
Dry Weight
Boulders
Over 12 in. (300mm)
Trace
< I 15
Cobbles
12 in to 3 in
With
15 - 29
(300mm to 75mm)
Modifier
> 1 30
Gravel
3 in. to #4 sieve
(75mm to 4 75mm)
RELATIVE PROPORTIONS OF FINES
Sand
#4 to #200 sieve
Descriptive Term(s)
14 75mmto 0.075mm)
(of Components Also
Percent of
Silt or Clay
Passing #200 Sieve
Present in Sample)
Dry Weight
(0 075mm)
Trace
< I 5
With
5-,12
Modifier
> 1 12
DRILLING & SAMPLING SYMBOLS
SS Split Spoon - 1 " I D, 2" O.D , unlf
ST Thin -Walled Tube - 2" O D., unless
R Ring Barrel Sampler - 2 42" 1 D , 3"
PA Power Auger
HA Hand Auger
DB Diamond Bit
AS Auger Sample
HS Hollow Stem Auger
Penetration Test Blows per foot of a
DRILLING AND EXPLORATION
otherwise noted PS Piston Sample
erwise noted WS : Wash Sample
) unless otherwise noted
FT • Fish Tad Bit
RB . Rock Bit
BS Bulk Sample
PM Pressure Meter
OC Dutch Cone
WB Wash Bore
pound hammer falling 30 inches on a 2-inch 0 D. split spoon, except where noted
WATER LEVEL MEASUREMENT SYMBOLS:
WL
Water Level
WS
While Sampling
WCI
Wet Cave in
I WD
While Drilling
DCI
Dry Cave in
BCR
Before Casing Removal
AB
After Boring
I I ACR
After Casting Removal
Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, the
indicated levels may reflect the locationlof groundwater In low permeability soils, the accurate determination of groundwater
levels is not possible with only short term observations
DESCRIPTIVE SOIL CLASSIFICATION
PHYSICAL PROPERTIES OF BEDROCK
Soil Classification is based on the Unified Soil Classification
DEGREE OF WEATHERING
system and the ASTM Designations D-2487 and D-2488
Coarse Grained Soils have more than 50% of their dry
Slight
Slight decomposition of parent material on
weight retained on a #200 sieve, they Jere described as
joints May Ibe color change
boulders, cobbles, gravel or sand Fine IGrained Soils have
less than 50% of their dry weight retained on a #200 sieve,
Moderate
Some decomposition and color change
they are described as clays, if they arel plastic, and silts if
throughout
they are slightly plastic or non -plastic iMajor constituents
may be added as modifiers and minor constituents may be
High
Rock highly decomposed, may be extremely
added according to the relative proportions based on grain
broken
size In addition to gradation, coarse grained soils are
defined on the basis of their relative in=place density and
HARDNESS AND DEGREE OF CEMENTATION
fine grained soils on the basis of their consistency
Limestone and Dolomite.
Example Lean clay with sand, trace grovel, stiff ICU, silty
Hard
Difficult to scratch with knife.
sand, trace gravel, medium dense (SM)
I
Moderately
Can be scratched easily with knife,
CONSISTENCY OF FINE-GRAINED SOILS
Hard
Cannot be scratched with fingernail
Unconfined Compressive I
Soft
Can be scratched with fingernail
Strength, Qu, psf Consistency
l
Shale, Sdtstone and Claystone:
< 500 Very Soft
Hard
Can be scratched easily with knife, cannot
500 - 1,000 Soft I
be scratched with fingernail
1,001 - 2,000 Medium
2,001 - 4,000 Stiff l
Moderately
Can be scratched with fingernail
4,001 - 8,000 Very Snff
Hard
8,001 - 16,000 Very i and
I
RELATIVE DENSITY OF COARSE -GRAINED SOILS.
Soft
Can be easily dented but not molded with
fingers
N-Blows/ft Relative Density
0-3 Very Loose
Sandstone and Conglomerate:
4-9 Loosel
Well
Capable of scratching a knife blade
10-29 Medium Dense
Cemented
30-49 Dense
50-80 Very Dense
Cemented
Can be scratched with knife
80 + Extremely Dense
Poorly
Can be broken apart easily with fingers
Cemented
k� I'll'=1�■ �1t�J11J
0
Geotechnical Engineering Report Terracon
City of Fort Collins Stormwater Utilities
Ter'racon Project No.120985231
TABLE OF CONTENTS
Page No.
Letter of Transmittal
I
INTRODUCTION....................................................................................................................I..
PROPOSED CONSTRUCTION............................................................................................1.
SITE EXPLORATION.I.........................................................................................................2.
Field Exploration)
2
Laboratory Testing
2
SITECONDITIONS..............................................................................................................3.
I
SUBSURFACE CONDITIONS..............................................................................................3.
Geology I
3
Sod Conditions
4
Field and Laboratory Test Results
4
Groundwater Conditions
4
ENGINEERING ANAL SES AND RECOMMENDATIONS
...................................................5
Geotechnical Considerations ...
5
Foundation Systems
5
Box Culvert Construction -- Dewatenng
6
Lateral Earth Pressures
7
Seismic Considerations
8
Floor Slab Design and Construction
8
Pavement Design and Construction
9
Earthwork
12
General Considerations ..
12
Site Preparation
12
Subgrade Preparation
13
Fill Materials and Placement 13
Excavation) and Trench Construction 15
Additional Design and Construction Considerations ... . .... . . ... 15
Underground Utility Systems 15
Corrosion 'Protection 16
GENERALCOMMENTS.....................................................................................................16
UNIFIED SOIL CLASSIFICATION SYSTEM
Cntona for Assigning Group Symbols and Group Names Using Laboratory Tests'
parse -Grained Gravels more than C
)ds more than 50% of coarse t
3% retained on fraction retained on
o 200 sieve No 4 sieve
ne-Grained Sods
)% or more
asses the
0 200 sieve
Gravels Less
5% finest Cu > 4 and 1 < Cc V,
1 >Cc> 3'
Is with Fines
than 12% finest Fines classify as NIL or MH
I
Sands 50% or more Clean Sands Less
of coarse fraction than 6% tines'
Passes No 4 sieve _ I
with FFnes
than 12% fineso
Silts and Clays
Liquid limit less
than 50
Silts and Clays inorgamc
Liquid limit 50
or more
-Cu
Cu <
Fines
asdy as CL or CH
and 1 < Cc < 3'
and/or 1 > Cc > 3'
issdy as MIL or MH
assify as CL or CH
PI > 7 and plots on or above "A line'
PI < 4 or Plots below "A" line'
Sod Classification
Group
;ymhol
Group Names
GW
Weil -graded gravel'
GP
Poorly graded gravy
GM
Silty gravel,G,H
GC
SW
Weil -graded sand'
SP
Poorly graded sand'
SM
Silty sand`"'
SC
Clayey sanda"'
CL
Lean clay''LN
ML
Sdt'LLN
lima - oven died
< 0 75 CL
limit - not dried
PI plots on or above "A"
PI lots below 'A" bne
Liquid limit - oven dried
<075
anic soils Primarily lorganic matter, dart in color, and
Based on the material passing the 3-in
75-mm) sieve
f field sample contained cobbles or
ioulders, or both, add "with cobbles or
Boulders, or both" to group name
Travels with 5 to 12% fines require dual
ymbols
;W-GM well -graded gravel with silt
;W-GC well -graded gravel with clay
;P-GM poorly graded gravel with silt
;P-GC poorly graded gravel with clay
;ands with 5 to 12% fines require dual
ymbols
,W-SM well -graded sand with silt
,W-SC well -graded sand with clay
;P-SM poorly graded sand with silt
,P-SC poorly graded sand with clay
'0
i °Cu�Dyv/DLv Cc ' D.v
I
'If sod contains > 159'o sand, add "with
sand" to group name
°If fines classify as CL-NIL, use dual symbol
GC -GM, or SC-SM
�If fines are organic, add 'with organic fines'
to group name
'If sod contains > 15% gravel, add "with
gravel" to group name
If Atterberg limits plot in shaded area, soil is
a CL-MIL, silty clay
i
— "a f v:e rl ni l9f'J =e'leeyrsr-
Jl
x "0
Z AEI ..., a11. .3 L-- iI II C✓a -
v
. �...: L,'.7 (Li.)
CH Fat
MH Elastic Sdt9 "'
Organic clay`LN1
OH
ll.nen.n e.liC.-Ne
PT Peat
'If sod contains 15 to 29% plus No 200, add
.with sand" or "with gravel', whichever is
predominant
Llf sod contains > 30016 plus No 200
predominantly sand, add 'sandy" to group
name
"If sod contains > 30% plus No 200.
predominantly gravel, add "gravelly" to group
name
"PI > 4 and pints on or above "A' line
.PI < 4 or plots below 'A" line
'PI plots on or above "A' line
oPl plots below "A" Lire
lfarrac®n
ROCK CLASSIFICATION
(Based on ASTM C-294)
Sedimentary Rocks
i
Sedimentary rocks are stratified materials laid down by water or wind. The sediments may be
composed of particles of pre-existing 'rocks derived by mechanical weathering, evaporation or by
chemical or organic origin. TI a sediments are usually indurated by cementation or compaction.
l
Chart Very fine-grained siliceous rock composed of micro -crystalline or crypto-
crystalline quartz, chalcedony or opal Chart is various colored, porous to
dense, hard and has a conchoicial to splintery fracture,
Claystone Fine-grained rock composed of or derived by erosion of silts and clays or any
rock containing clay Soft massive; gray, black, brown, reddish or green and
may coI ntain carbonate minerals.
Conglomerate Rock consisting of a considerable amount of rounded gravel, sand and
cobbles with or without interstitial or cementing material. The cementing or
interstitial material may be quartz, opal, calcite, dolomite, clay, iron oxides or
other materials.
Dolomite A fine-grained carbonate rock consisting of the mineral dolomite [CaMg
(CO3)21.1 May contain noncarbonate impurities such as quartz, chart, clay
minerals, organic matter, gypsum and sulfides. Reacts with hydrochloric acid
(HCL)
Limestone A fine-grained carbonate rock consisting of the mineral calcite (CaCO3)' May
containlnoncarbonate impurities such as quartz, cheri, clay minerals, organic
matter, (gypsum and sulfides. Reacts with hydrochloric acid (HCL)•
Sandstone Rock consisting of particles of sand with or without interstitial and cementing
materials. The cementing or interstitial material may be quartz, opal, calcite,
dolomite, clay, iron oxides or other material
i
Shale Fine-grained rock composed of, or derived by erosion of silts and clays or any
rock containing clay Shale is hard, platy, or fissile may be gray, black,
reddish or green and may contain some carbonate minerals (calcareous
shale)
Siltstone Fine grlained rock composed of, or derived by erosion of silts or rock
containing silt. Siltstones consist predominantly of silt sized particles
(0 0625 to 0.002 mm in diameter) and are intermediate rocks between
claystones and sandstones, may be gray, black, brown, reddish or green and
may coitain carbonate minerals.
0
ROCK CLASSIFICATION
(Based on ASTM C-294)
Igneous Rocks
Igneous rocks are formed byecooling from a molten rock mass (magma). Igneous rocks are divided
into two classes (1) plutonic, or intrusive, that have cooled slowly within the earth; and (2)
volcanic, or extrusive, that 'formed from quickly cooled lavas. Plutonic rocks have grain sizes
greater than approximately 11 mm, and are classified as coarse- or medium -grained. Volcanic rocks
have gram sizes less than approximately 1 mm, and are classified as fine-grained. Volcanic rocks
frequently contain glass. Both plutonic and volcanic rocks may consist of porphyries that are
characterized by the presence of large mineral grams in a fine-grained or glassy groundmass. This
is the result of sharp changes in rate of cooling or other physico-chemical conditions during
solidification of the melt. I
Granite Graniteiis a medium- to coarse -grained light-colored rock characterized by the
presence of potassium feldspar with lesser amounts of plagioclase feldspars
and quartz. The characteristic potassium feldspars are othoclase or
microclme, or both; the common plagioclase feldspars are albtte and
otgoclase Feldspars are more abundant than quartz. Dark -colored mica
(biotite)I is usually present, and light-colored mica (muscovite) is frequently
present. Other dark -colored ferromgnesian minerals, especially hornblende,
may be (present in amounts less than those of the light-colored constituents
I
Quartz-Monzonite Rocks similar to granite but contain more plagioclase feldspar than potassium
and Grano -Diorite feldspar.
Basalt Fine-grained extrusive equivalent of gabbro and diabase. When basalt
contains natural glass, the glass is generally lower in silica content than that
of the lighter -colored extrusive rocks.
ROCK CLASSIFICATION
(Based on ASTM C-294)
Metamorphic Rocks
I
Metamorphic rocks form from igneous, sedimentary, or pre-existing metamorphic rocks in response
to changes in chemical and physical conditions occurring within the earth's crust after formation of
the original rock. The changes may be textural, structural, or mineralogic and may be accompanied
by changes in chemical composition. The rocks are dense and may be massive but are more
frequently foliated (laminated or layered) and tend to break into platy particles. The mineral
composition is very variable depending in part on the degree of metamorphism and in part on the
composition of the original rock.
Marble
Metaquartzite
Slate
Schist
A recrystallized medium- t
calcite or dolomite, or cal
present lin the form of new
and graphite.
I
A granular rock consisting
and resistance to weatherin
o coarse -grained carbonate rock composed of
cite and dolomite. The original impurities are
minerals, such as micas, amphiboles, pyroxenes,
g
A fine -gamed metamorphic rock that is distinctly laminated and tends to split
into thin parallel layers. The mineral composition usually cannot be
determined with the unaided eye.
A highly, layered rock tending to split into nearly parallel planes (schistose) in
which the gram is coarse enough to permit identification of the principal
minerals! Schists are subdivided into varieties on the basis of the most
prominent mineral present in addition to quartz or to quartz and feldspars; for
mstancei mica schist. Greenschist is a green schistose rock whose color is
due to abundance of one or more of the green minerals, chlonte or amphibole,
and is commonly derived from altered volcanic rock.
Gneiss One of the most common metamorphic rocks, usually formed from igneous or
sedimentary rocks by a higher degree of metamorphism than the schists. It is
characterized by a layered or foliated structure resulting from approximately
parallel lenses and bands of platy minerals, usually micas or prisms, usually
amphiboles, and of granular minerals, usually quartz and feldspars. All
intermediate varieties between gneiss and schist and between gneiss and
granite are often found in the same areas in which well-defined gneisses
occur. i
I
LABORATORY TESTS
SIGNIFICANCE AND PURPOSE
TEST SIGNIFICANCE PURPOSE
California
Used to evaluate the potential strength of subgrade sod,
Pavement
Bearing
subbase, and Base course material, including recycled materials
Thickness
Ratio
for use in roadland airfield pavements.
Design
Consolidation
Used to develop an estimate of both the rate and amount of
Foundation
both differential and total settlement of a structure.
Design
Direct
Used to determine the consolidated drained shear strength of
Bearing Capacity,
Shear
sod or rock.
Foundation Design &
Slope Stability
Dry
Used to determine the in -place density of natural, inorganic,
Index Property
Density
fine-grained sods.
Soil Behavior
Expansion
Used to measure the expansive potential of fine-grained soil
Foundation & Slab
and to provide a basis for swell potential classification.
Design
Gradation
Used for the quantitative determination of the distribution of
Soil
particle sizes iri sod.
Classification
Liquid &
Used as an integral part of engineering classification systems
Soil
Plastic Limit,
to characterize Ithe fine-grained fraction of sods, and to specify
Classification
Plasticity Index
the fine-grained fraction of construction materials.
Permeability
Used to determine the capacity of sod or rock to conduct a
Groundwater
liquid or gas. l
Flow Analysis
pH
Used to determine the degree of acidity or alkalinity of a sod.
Corrosion
Potential
ResisSvity
Used to indicate the relative ability of a soil medium to carry
Corrosion
electrical currents.
Potential
R-Value
Used to evaluate the potential strength of subgrade soil,
Pavement
subbase, and base course material, including recycled materials
Thickness
for use in road and airfield pavements.
Design
Soluble
Used to determine the quantitative amount of soluble sulfates
Corrosion
Sulphate
within a soil mass.
Potential
Unconfined
To obtain the approximate compressive strength of soils that
Bearing Capacity
Compression
possess sufficient cohesion to permit testing in the unconfined
Analysis
state.
for
Foundations
Water
Used to determine the quantitative amount of water in a soil
Index Property
Content
mass
Soil Behavior
I
i
REPORT TERMINOLOGY
(Based on ASTM D653)
Allowable Soil
i
The recommended maximum contact stress developed at the interface of the
Bearing Capacity
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.
i
Aggregate Base
A layer of specified material placed on a subgrade or subbase usually beneath
Course
slabs or pavements.
i
Backfill
A specified material placed and compacted in a confined area.
Bedrock
A naturallaggregate 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
i
A concrete foundation element cast in a circular excavation which may have an
or Shaft)
enlarged base. Sometimes referred to as a cast -in -place pier or drilled shaft.
I
Coefficient of
A constant proportionality factor relating normal stress and the corresponding
Friction
shear stress at which sliding starts between the two surfaces.
Coluuvium
Soil, the constituents of which have been deposited chiefly by gravity such as at
the foot of a slope or cliff.
Compaction
The densrfication of a soil by means of mechanical manipulation.
Concrete Slab -on-
A concrete surface layer cast directly upon a base, subbase or subgrade, and
Grade
typically used as a floor system.
Differential
Unequal settlement or heave between, or within, foundation elements of a
Movement
structure.)
Earth Pressure
The press Iure or force 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, Ill 8,000 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
sod. Thislsimplified 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-
Materials deposited through the action of man prior to exploration of the site.
made rill)
Existing Grade
The ground surface at the time of field exploration.
L'F
REPORT TERMINOLOGY
(Based on ASTM D653)
Expansive Potential The potential of a sod to expand (increase in volume) due to absorption of
moistu re.
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 sod.
Foundation
The lower part of a structure that transmits the loads to the sod or bedrock.
Frost Depth
The depth of 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 sods, or within fractures in
bedrock.
i
Heave
Upward movement.
Lithologic
The characteristics which describe the composition and texture of sod and rock
by observation.
Native Grade
The naturally occuring ground surface
Native Soil
Naturally occurring on -site sod, sometimes referred to as natural sod
Optimum Moisture
The water content at which a soil can be compacted to a maximum dry unit
Content
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 continuing stratum.
Scarify
To mechanically loosen soil or break down existing sod structure.
Settlement
Downward movement.
Skin Friction (Side
The frictional resistance developed between sod and an element of structure
Shear)
such asi a drilled pier or shaft.
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 sod 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 sod prepared and compacted to support a structure, slab or pavement
system.
Geotechnical Engi
City of Fort Collins
Terracon Project N
SITE PLAN
APPENDIX A
Logs of Borings
APPENDIX B
Laboratory Test
APPENDIX C
General Notes
�J
>rt Terracon
Utilities
Figure No.
ro
11
INTRODUCTION
This report contains the
Howes Street Outfall Prol
and continuing north to L
Northeast'% of Section 1
Colorado
The purpose of these
recommendations relativ
Terracon
GEOTECHNICAL
G REPORT
OF FORT COLLINS STORMWATER UTILITIES
PROPOSED HOWES STREET OUTFALL
FORT COLLINS, COLORADO
TERRACON PROJECT NO. 20985231
FEBRUARY 10, 1999
-esults of our geotechnical engineering exploration for the proposed
=ct located between Mason and Howes Streets, from LaPorte Avenue
Be Martinez Park in Fort Collins, Colorado The site is located in the
I, Township 7 North, Range 69 West of the 6th P M , Larimer County,
is to provide information and geotechnical engineering
• subsurface sod and bedrock conditions
• groundwaterconditions
• foundation design and construction
• lateral earth pressures
• pavement design and construction
• earthwork
• drainage
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
Based on information provided, it is our understanding the project is to consist of either precast
or cast -in -place concrete box culvert type structures along with pavement replacement and
construction of a'small embankment and water quality pond The box culvert inverts are to be
constructed at approximate depths of 8 to 12 feet below existing site grades
Geotechnical Engine
City of Fort Collins S
Terracon Project No.
SITE EXPLORATION
The scope of the sei
geotechnical engineer
analyses
Field Exploration
A total of nine (9) test b
approximate depths of 15
Plan, Figure 1 The te:
proposed alignment and/
mounted drilling ng, utilize
Terracon
Report
water Utilities
m performed for this project included a site reconnaissance by a
subsurface exploration program, laboratory testing and engineering
rags were drilled on January 7, 1999 The borings were drilled to
20 feet below existing site grades at the locations shown on the Site
borings were spaced at approximate 500 foot intervals along the
at the major structures The borings were advanced with a truck-
4-inch diameter solid stem augers
The borings were located in the field by measurements from or existing site features Elevations
at each test boring location were interpolated from the contour maps provided by the client and
are included on the Logs of Bonngs in Appendix A The accuracy of boring locations and
locations should only be assumed to the level implied by the methods used.
Continuous lithologic logs of each boring were recorded by the geotechnical engineer during the
drilling operations At selected intervals, samples of the subsurface materials were taken by
means of pushing thin -walled Shelby tubes, or by driving split -spoon and/or ring barrel samplers
A composite sample was obtained from Test Boring No 4 to determine the subgrade strength
characteristics
Penetration resistance measurements were obtained by driving the split -spoon and/or ring barrel
samplers into the subsurface materials with a 140-pound hammer falling 30 inches The
penetration resistance vallue 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 the site exploration The
test borings were backfilled upon completion of the drilling operations.
Laboratory Testing
All samples retrieved during the field exploration were returned to the laboratory for observation
by the project geotechnical engineer and were classified in accordance with the Unified Sod
2
0
Geotechnical Engineering Report
City of Fort Collins Stormwater Utilities
Terracon Project No. 20985231
Terracon
Classification System described in Appendix C Samples of bedrock were classified in
accordance with the general notes for Bedrock Classification At that time, the field descriptions
were confirmed or modifed 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 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 ASTM, local or other accepted standards
Selected sod and bedrock) samples were tested for the following engineering properties
• Water Content • Expansion
• Dry Density, • Plasticity Index
• Consolidation • Water Soluble Sulfate Content
• Compressive Strength R-Value
SITE CONDITIONS
The proposed Howes Sti
an alley, crosses Maple
Cherry Street and events
Lee Martinez Park
SUBSURFACE
Geology
The proposed area is
physiographic province
quaternary time (apprc
separates the Southern
the western flank of the
(approximately 70,000,0
Outfall Protect begins at LaPorte Avenue, continues north through
:et, continues through an existing parking area, extends across
wdl empty into a small embankmenttwater quality pond located in
cated within the Colorado Piedmont section of the Great Plains
The Colorado Piedmont formed during Late Tertiary and Early
nately 2,000,000 years ago), is a broad, erosional trench which
)cky Mountains from the High Plains Structurally, the site lies along
anver Basin During the Late Mesozoic and Early Cenozoic Periods
years ago), intense tectonic activity occurred, causing the uplifting of
3
C
Geotechnical Engine
City of Fort Collins S
Terracon Project No.
the Front Range and asi
uplands and broad valley
this region The site iE
underlies the site at app
overlain by alluvial sands
Report
vater Utilities
Terracon
,sated downwarping of the Denver Basin to the east Relatively flat
characterize the present-day topography of the Colorado Piedmont in
underlain by the Cretaceous Pierre Formation The Pierre shale
)ximate depths of 6 to 15 feet below the surface The bedrock is
nd clays of Pleistocene and/or Recent Age
Mapping completed by the Colorado Geological Survey ('Hart, 1972), Indicates the site in an
area of "Low to Moderate Swell Potential" Potentially expansive materials mapped in this area
Include bedrock, weathered bedrock and colluvium (surficial units)
Soil Conditions
The majority of the site is presently overlain by approximately 2 to 8 inches of asphalt, 4 to 8
inches of aggregate base course and/or by an approximate 1 to 4 feet of fill Silty topsoil
consisting of root growth and organic matter was encountered at the surface of test borings 8
and 9 Silty sand and sand with gravel lenses were encountered underlying the pavement and
fill materials and extended to approximate depths of 6 '/2 to 13 feet below existing grades
Claystone/sandstone/siltstone bedrock was encountered in all nine test borings at approximate
depths of 6'/2 to 13 feet, and extended to the depths explored
Field and Laboratory Test Results
Field and laboratory test 'results indicate the sand soils are medium dense to dense in relative
density and exhibit moderate beanng characteristics and low swell potential The bedrock
stratum varies from weathered, moderately hard to hard with increasing depths and exhibits a
low to moderate swell potential
Groundwater
Groundwater was encountered in Borings 1, 2, 3, 8 and 9 at approximate depths of 4 to 13 '/z
feet at the time of field exploration Borings 4, 5, 6 and 7 were dry at the time of drilling. Water
measurements were obtained in Test Bonngs 3, 5, and 7, 2 days after drilling operations as
indicated on the Logs of Bonngs included in Appendix A The remaining test bonngs were
back -filled upon completion of drilling operations These observations represent groundwater
'Hart, Stephen S , 1972, Potentially Swelling Soil and Rock in the Front Range Urban Corridor, Colorado, Colorado
Geological Survey, Environmental I Geology No 7
4