HomeMy WebLinkAbout20042146 PRELIMINARY GEOTECHNICAL ENGINEERING REPORT
PROPOSED 70 ACRE SUBDIVISION
WELD COUNTY ROADS 22 AND 19
WELD COUNTY, COLORADO
. TERRACON PROJECT NO. 21995142
November 17, 1999
Prepared for:
Don and Linda Owens
8585 Weld County Road 22
Fort Lupton, Colorado 80621
Prepared by:
Terracon
1289 First Avenue
Greeley, Colorado 80631
Exhibit 3
lrerracon
2004-2146
lierracon
PO.Box 1744•1289 First Avenue
November 17, 1999 Greeley,Colorado o80632-1744
(970)351-0460 Fax:(97%5 353-8639
Don and Linda Owens
8585 Weld County Road 22
Fort Lupton, Colorado 80621
Re: Preliminary Geotechnical Engineering Report
Proposed 70 Acre Subdivision
Weld County, Colorado
Terracon Project No. 21995142
Terracon has completed a preliminary geotechnical engineering exploration for the proposed
subdivision to be located near the intersection of Weld County Roads 22 and 19. This study was
performed in general accordance with our proposal number 2199p126 dated October 14, 1999.
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 preliminary design
and construction of foundations and other earth connected phases of this project are attached.
The subsurface soils at the site consisted of silty sand, silty clayey sand and sandy lean clay. The
soils are underlain in various borings by claystone and siltstone bedrock at depths of 51/2 to 25 feet.
The results of our field exploration and laboratory testing indicate that the soils have non to low
expansive potential and the bedrock has moderate to high expansive potential.
Based on the preliminary geotechnical engineering analyses, subsurface exploration and laboratory
test results, it is our opinion that proposed structures may be supported on a spread footing or a
drilled pier and grade beam foundation system depending on the proximity to the bedrock. The
preliminary percolation tests indicate that standard septic systems should be feasible throughout
much of the property. However, shallow groundwater will be a concern on the western portion of the
property for septic systems and foundation construction. Final soil borings and percolation tests
should be performed at each building location once residential and leach field locations have been
determined.
Slab on grade construction appears to be feasible for garage and upper level slabs. Given the
engineering characteristics of the bedrock which may support basement slabs, consideration should
be given to removal of certain portions of expansive subgrade materials beneath basement slabs,
and replacement with non-expansive soils. If no movement can be tolerated, consideration should
be given to use of structural floor systems.
Other preliminary design and construction recommendations, based upon geotechnical conditions,
are presented in the report. ky • MinneArizona • Arkansas
Neb aska■ Ne ada ■ New Mexico �Colorado • Georgia nOkl homasl♦ Te ness a ■sTexa ■ Utaas • ah■ Wisconsin Montana
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Quality Encino^ring Since 1965
Preliminary Geotechnical Engineering Report
70 Acre Subdivision
Terracon Project No. 21995142
We appreciate being of service to you in the preliminary geotechnical engineering phase of this
project, and are prepared to assist you during the final design and 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, „\<,oc v aFcss TERRACON 1CCC8 'c'• %o
Prepared by: ` Reviewed by:
Doug Lefgre P.G. ` Lewis Daniel Israel, P.E.
Office Manager/Senior Regional Manager
Copies to: Addressee (3)
Coldwell Banker- Mr. Ed Pruss (1)
r
III
TABLE OF CONTENTS
Page No.
Letter of Transmittal
1
INTRODUCTION
PROPOSED CONSTRUCTION 1
SITE EXPLORATION 2
Field Exploration 2
Laboratory Testing 2
SITE CONDITIONS 3
SUBSURFACE CONDITIONS 3
3
Geology 4
Soil and Bedrock Conditions 4
Field and Laboratory Test Results 4
Groundwater Conditions
PRELIMINARY ENGINEERING ANALYSES AND RECOMMENDATIONS 5
Geotechnical Considerations 5
Foundation Systems - Drilled Piers 5
Foundation Systems - Footings 6
Basement Construction 6
Seismic Considerations 7
Septic System Construction 7
7
Earthwork 7
General Considerations 7
Site Preparation 8
Fill Materials and Placement 9
Additional Design and Construction Considerations
Exterior Slab Design and Construction 99
Surface Drainage
10
GENERAL COMMENTS
TABLE OF CONTENTS (Cont'd)
APPENDIX A
Site Plan
Logs of Borings
APPENDIX B
General Notes
Unified Soil Classification
bedrock Classification
PRELIMINARY GEOTECHNICAL ENGINEERING REPORT
PROPOSED 70 ACRE SUBDIVISION
WELD COUNTY ROADS 22 AND 19
WELD COUNTY, COLORADO
TERRACON PROJECT NO. 21995142
NOVEMBER 17, 1999
INTRODUCTION
This report contains the results of our preliminary geotechnical engineering exploration for the
proposed subdivision to be located near the intersection of Weld County Roads 22 and 19. The
site is located in the southeast quarter of Section 9, Township 2 North. Range 67 West of the 6th
Principal Meridian.
The purpose of these services is to provide information and preliminary geotechnical engineering
recommendations relative to:
• subsurface soil and bedrock conditions
• groundwater conditions
• foundation design and construction
• basement construction
• floor slab design and construction
• septic systems
• earthwork
• drainage
The preliminary 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
As we understand it, the subdivision will be developed for single-family residences that will be
serviced by on site sewage disposal systems.
Preliminary Geotechnical Engineering Report
70 Acre Subdivision
Terracon Project No. 21995142
SITE EXPLORATION
The scope of the services performed for this project included a site reconnaissance by an
engineering geologist, a subsurface exploration program, laboratory testing and engineering
analyses.
Field Exploration
A total of six test borings were drilled on October 13, 1999. The borings were drilled to
approximate depths of 15 to 30 feet at the locations shown on the Site Plan, Figure 1. Additionally,
one percolation test boring was drilled adjacent to the soil test borings. All borings were advanced
with a truck-mounted drilling rig, utilizing 4- and 6-inch diameter solid stem augers.
The borings were located in the field by pacing from property lines and/or existing site features with
the help of the client. The accuracy of boring locations should only be assumed to the level implied_
by the methods used.
r Continuous lithologic logs of each boring were recorded by the engineering geologist during the
drilling operations. At selected intervals, samples of the subsurface materials were taken by
pushing thin-walled Shelby tubes, or by driving split-spoon samplers.
Penetration resistance measurements were obtained by driving the split-spoon 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 the drilling.
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 general accordance with the Unified Soil
Classification System described in Appendix B. Samples of bedrock were classified in general
accordance with the general notes for Bedrock Classification. 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 and bedrock samples. The test results were
used for the preliminary geotechnical engineering analyses, and the development of preliminary
2
Preliminary Geotechnical Engineering Report
70 Acre Subdivision
Terracon Project No. 21995142
foundation and earthwork recommendations. All laboratory tests were performed in general
accordance with the applicable ASTM, local or other accepted standards.
Selected soil and bedrock samples were tested for the following engineering properties:
• Water Content • Expansion
• Dry Density • Compressive Strength
• Atterberg Limits • Percent Fines
SITE CONDITIONS
The site is currently used as pasture ground for horses and cattle. Surface drainage is poor to fair
to the northeast. The property is vegetated with native grasses and weeds. Several fences divide
the site into individual pastures. Two oil and/or gas wells were observed near the center and
southern portions of the site. A small oil tank battery was observed near the northern property
boundary. An oil field supply yard is located near the southeast corner of the property. The site is
bounded to the south and east by Weld County Roads 22 and 19 respectively. An existing lake is
located southwest of the site. Pasture and agricultural ground was observed west and north of the
property. A single-family residence was observed near the northeast corner of the site.
SUBSURFACE CONDITIONS
Geology
The proposed area is located within the Colorado Piedmont section of the Great Plains
physiographic province. The Colorado Piedmont, formed during Late Tertiary and Early quaternary
time (approximately 2,000,000 years ago), is a broad, erosional trench which separates the
Southern Rocky Mountains from the High Plains. Structurally, the site lies along the western flank
of the Denver Basin. During the Late Mesozoic and Early Cenozoic Periods (approximately
70,000,000 years ago), intense tectonic activity occurred, causing the uplifting of the Front Range
and associated downwarping of the Denver Basin to the east. Relatively flat uplands and broad
valleys characterize the present-day topography of the Colorado Piedmont in this region. The site
is underlain by the Cretaceous Laramie Formation. The Laramie consists of interbedded
sandstone, siltstone and claystone units. Minor coal units are also observed within the Laramie.
Based on USGS subsidence maps, it does not appear that the site has had mining activity beneath
the property. Holocene (Recent) alluvial and/or eolian deposits overlie the Laramie.
2,a
3
Preliminary Geotechnical Engineering Report
70 Acre Subdivision
Terracon Project No. 21995142
Soil and Bedrock Conditions
As presented on the Logs of Boring, surface soils to depths of 6% to 25 feet consisted of silty sand,
silty clayey sand and sandy lean clay. The materials underlying the surface soils and extending to
the maximum depth of exploration consisted of claystone and siltstone bedrock.
Field and Laboratory Test Results
Field test results indicate that the sand soils vary from very loose to medium dense in relative
density and the clay soils are in consistency. The bedrock varies from weathered to moderately
hard in hardness.
Laboratory test results indicate that the soils have non to low expansive potential. The bedrock is
moderately to highly expansive.
Preliminary percolation testing is summarized as follows:
Pe °tattm5 Test ResccCts
F stHb[eil { _ CQepttW a S Soil f ,Percolationxk ate ':
,,•;" (inches tasslficatfore-, (minutesltnch.)c
1 36 I
SM 85
2 36 SM 15
3 i 36 SM 15
4 36 SM 105
5 j 36 SM h8
6 j 36 SM 10
Preliminary field test results indicate the soils have fair to poor percolation characteristics.
Groundwater Conditions
Where encountered, groundwater was encountered at approximate depths of 3% to 14 feet in the
test borings at the time of field exploration. When checked 1 day after the drilling, groundwater
was measured in borings 1, 3, 4 and 5 at approximate depths of 2 to 10'/s 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.
4
r Preliminary Geotechnical Engineering Report
70 Acre Subdivision
Terracon Project No. 21995142
PRELIMINARY ENGINEERING ANALYSES AND RECOMMENDATIONS
Geotechnical Considerations
The site appears suitable for the proposed construction from a geotechnical engineering point of
view. Potentially expansive bedrock and shallow groundwater will require particular attention in the
design and construction.
The following foundation systems were evaluated for use on the site:
• grade beams and straight shaft piers drilled into bedrock;
• spread footings and/or grade beams bearing on undisturbed soils; and,
• spread footings and/or grade beams bearing on engineered fill.
If the owner is willing to accept potential slab movements, slab-on-grade construction, for garage
areas and upper level footings, is considered acceptable provided that design and construction
recommendations are followed. Given the engineering characteristics of the bedrock.
consideration should be given to use of structural floor systems in basement areas where these
materials will be encountered. Evaluation of expansion tests conducted on individual lots during
supplemental geotechnical exploration is recommended to assess the need for structural floor
systems.
Preliminary design and construction recommendations for foundation systems and other earth
connected phases of the project are outlined below. The recommendations contained in the report
are based upon widely spaced borings and limited laboratory testing. As such, supplemental
geotechnical exploration, laboratory testing and engineering analysis are recommended once final
building locations and site configurations have been established in order to develop design and
construction recommendations.
Foundation Systems - Drilled Piers
Due to the presence of moderately to highly expansive ctaystone bedrock on the site, a grade
beam and drilled pier foundation system is recommended for support of proposed structures
founded within three feet of expansive bedrock. Straight shaft piers, drilled a minimum of 7 feet
into firm or harder bedrock, with a minimum shaft length of 20 feet are recommended.
Drilling to design depths should be possible with conventional single flight power augers.
Groundwater conditions indicate that temporary steel casing may be required to properly drill and
5
Preliminary Geotechnical Engineering Report
70 Acre Subdivision
Terracon Project No. 21995142
clean piers prior to concrete placement. Groundwater should be removed from each pier hole prior
to concrete placement. Pier concrete should be placed immediately after completion of drilling and
cleaning. If pier concrete cannot be placed in dry conditions, a tremie should be used for concrete
placement.
Foundation Systems - Footings
Due to the presence of low-swelling soils on the site, spread footing foundations bearing upon
undisturbed subsoils and/or engineered fill may be used for support of proposed structures where
the foundation is located at least three feet above the bedrock. The footings may be preliminarily
designed for maximum bearing pressures of 1,000 to 2,000 psf. The design bearing pressure
applies to dead loads plus design live load conditions. The design bearing pressure may be
increased by one-third when considering total loads that include wind or seismic conditions.
Exterior footings should be placed a minimum of 30 inches below finished grade for frost protection
and to provide confinement for the bearing soils. Finished grade is the lowest adjacent grade for
perimeter footings.
Foundations and masonry walls should be reinforced as necessary to reduce the potential for
distress caused by differential foundation movement. The use of joints at openings or other
discontinuities in masonry walls is recommended.
Foundation excavations should be observed by the geotechnical engineer. If very loose sand soils
are present at the foundation bearing level, or if the soil conditions encountered differ significantly
from those presented in this report, supplemental recommendations will be required.
Basement Construction
Groundwater was encountered on the site at depths of 2 to greater than 15 feet below existing
grade. Full-depth basement construction is considered feasible on portions of the site provided
that basement subgrade is placed three feet above the groundwater. The western portion of site,
nearest the lake southwest of the property, may require crawl space or slab on grade construction.
To reduce the potential for groundwater to enter the basement of the structure, installation of a
dewatering system is recommended. The dewatering system should, at a minimum, include an
underslab gravel drainage layer sloped to an interior perimeter drainage system.
6
F^ Preliminary Geotechnical Engineering Report
70 Acre Subdivision
Terracon Project No. 21995142
Seismic Considerations
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 soil profile type Sc should be used for the design cf structures for the proposed project (1997
Uniform Building Code, Table No. 16-J).
Septic System Construction
Preliminary field test results indicate that standard septic systems are feasible for construction on
portions of the site. Shallow groundwater conditions will be the limiting factor in the installation of
standard systems. Final soil percolation testing should be performed when absorption bed
locations for each residence are determined. The systems should be designed in accordance with
applicable state and county requirements and should be located at the minimum distances from all
pertinent ground features described in Weld County regulations.
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, foundation 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
•
building and pavement areas. All exposed surfaces should be free of mounds and
depressions which could prevent uniform 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.
7
^ Preliminary Geotechnical Engineering Report
70 Acre Subdivision
Terracon Project No. 21995142
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. Well points may be required for significant groundwater flow, or
where excavations penetrate groundwater to a significant depth.
Underground utility lines were observed at the site for the oil and/or gas wells and tanks
located on the property. Other underground 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.
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.
Fill Materials and Placement
Clean on-site soils or approved imported materials may be used as fill material.
Bedrock materials are not recommended for use as fill or backfill material.
Imported soils (if required) should conform to the following unless approved by the project
geotechnical engineer
Percent fines by weight
Gradation ASTM C136)
6" 100
3" 70-100
No. 4 Sieve 50-100
No. 200 Sieve 60 (max)
• Liquid Limit 30 (max)
• Plasticity Index 10 (max)
8
PaN, 7Th
Preliminary Geotechnical Engineering Report
70 Acre Subdivision
Terracon Project No. 21995142
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 are as follows:
Minimum Percent
Material JASTM D6981
Scarified subgrade soils 95
On-site and imported fill soils: •
Beneath foundations 95
Beneath slabs 95
Miscellaneous backfill (non-structural areas) 90
On-site or imported sand soils should be compacted within a moisture content range of 3
percent below to 3 percent above optimum unless modified by the project geotechnical
,/1 engineer.
Additional Design and Construction Considerations
Exterior Slab Design and Construction
Exterior slabs-on-grade, exterior architectural features, and utilities founded on, or in backfill
may experience some movement due to the volume change of the backfill. Potential
movement could be reduced by:
• minimizing moisture increases in the backfill
• controlling moisture-density during placement of backfill
• using designs which allow vertical movement between the exterior features and
adjoining structural elements
• placing effective control joints on relatively close centers
Surface Drainage
Positive drainage should be provided during construction and maintained throughout the life
of the proposed project. Infiltration of water into utility or foundation excavations must be
prevented during construction. Planters and other surface features which could retain water
in areas adjacent to the building or pavements should be sealed or eliminated. In areas
9
-- Preliminary Geotechnical Engineering Report
70 Acre Subdivision
Terracon Project No. 21995142
where sidewalks or paving do not immediately adjoin the structure, we recommend that
protective slopes be provided with a minimum grade of approximately 10 percent for at least
10 feet from perimeter walls. Backfill against footings, exterior walls, and in utility and
sprinkler line trenches should be well compacted and free of all construction debris to
reduce the possibility of moisture infiltration.
Downspouts, roof drains or scuppers should discharge into splash blocks or extensions
when the ground surface beneath such features is not protected by exterior slabs or paving.
Sprinkler systems should not be installed within 5 feet of foundation walls. Landscaped
irrigation adjacent to the foundation system should be minimized or eliminated.
GENERAL COMMENTS
Terracon should be retained to perform the final subsurface exploration and review the final design
plans and specifications so comments can be made regarding interpretation and implementation of
our preliminary 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 variations which may occur between borings or across the site. The
nature and extent of such variations may not become evident until construction. If variations
appear, it 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
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.
10
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WELD COUNTY ROAD 22 BORING LOCATION PLAN
\ PROPOSED RESIDENTIAL SUBDIVISION
N wE.D COUNTY ROADS 22&19
WELD COUNTY,COLORADO
PIcjlieNnr DML �+ r}I� �°°N' 21995142
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Cada By: 1289 FIRST AVENUE
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AppraaE By. DML GREELEY,COLORADO 80831 Ov.RBy. DML
OI.A RAM IS FCA GENERAL LOCATION ONLY. Fy Nn. T'�N°'
•ANO LS NnT IN;_ICED FOR CONSTRUCTION PURPOSES
•
LOG OF BORING No. 1 Page I of 1
CLIENT ARCHITECT/ENGINEER
Don and Linda Owens
SITE Weld County Roads 22 & 19 PROJECT
Weld County, Colorado Preliminary Soil and Percolation Tests
I SAMPLES I TESTS
0 ! i ` i � IL
CI L 2 . = C I B I Z I Z..-' C
U i DESCRIPTION I _ ' ! [„' > z = m v
E= in 2 _ C . 3 n iC iqZ -
G _ J = J E_O O i }._ ,v= ' `wt_
o C = Z - _ 1 me 2 C_ :DW_ tic-a_
0.5 TOPSOIL 6" -SM: 1 SS 18" 7 ii
I. SILTY SAND -
Brown to tan, moist to wet ? —
I I Loose to very loose = _ I 2 : ST I NR1 I I
i _ 3 SS , 12"I 3 191 I
_ I
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25.0 25
1165
.;?1 WEATHERED CLAYSTONE — i
Gray to tan, moist, soft — i
30.0 30 l
BOTTOM OF BORING
I !
I
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES
es._ BETWEEN SOIL AND ROCK TYPES: IN-SITU.THE TRANSITION MAY BE GRADUAL-
WATER LEVEL OBSERVATIONS BORING STARTED 10-13-99
WL is= 3.5' W.D.:t 2.3; A.B. BORING COMPLETED 10-13-99
WL . lierracon RIG CME-55 FOREMAN DBC
WL I Water Checked 1 Day A.B.
APPROVED DML ;10Ba 21995142
LOG OF BORING No. 2 Page 1 of 1
'� CLIENT ARCHITECT/ENGINEER
Don and Linda Owens
SITE Weld County Roads 22 & 19 PROJECT
Weld County, Colorado Preliminary Soil and Percolation Tests
, SAMPLES TESTS
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— DESCRIPTION I >- m j z71 � ! zJ
a 7. en = w I C � 3 t G %z
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SILTY SAND -
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Brown to tan, moist , :
I 1 Loose to medium dense i .
I 21 SS ! 12"' 3 7i
5
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7.0
SANDY LEAN CLAY 3 ST L?" 6! 107
Tan, moist, stiff -CL; 4 '; SS 12" 12 19:
10-, 1
11.5 _
WEATHERED CLAYSTONE
• Gray to tan, moist, soft _
"' '' 15.0 5 SS 122" 45 16;
BOTTOM OF BORLNG 1c- y •
i
•
•
•
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES
^� BETWEEN SOIL AND ROCK TYPES: IN-S[11:.THE TRANSITION MAY BE GRADUAL.
WATER LEVEL OBSERVATIONS BORING STARTED 10-13-99
WL = None W.D.I1 None AS. BORING COMPLETED 10-13-99
wL err acon RIG CME-55 i FOREMAN DBC
WL Water Checked 1 Day A.B. APPROVED MIL 'JOB/ 21995142
LOG OF BORING No. 3 Page 1 of I
�-
CLIENT ARCHITECT/ENGINEER
Don and Linda Owens
SITE Weld County Roads 22 & 19 PROJECT
Weld County, Colorado Preliminary Soil and Percolation Tests
' SAMPLES TESTS _
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'! 0.5 TOPSOIL 6- —SM: 1 ' SSI 18"I 14 4i
—
I SILTY SAND
Brown to tan, moist —
Loose to medium dense — 2 ! ST 12" 4 110 NViNP/LS
31SSi 12"' 6 4;
I 5
. I 7.5 —
•
fS'�, SILTY CLAYEY SAND _ SC 4 SS 12"' 11 22.
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41 Loose ID medium dense 10—
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I.4i -
f ri
_ -
:x:16r*' — 5 ; SS; 12" 8 17
15.0 15
BOTTOM OF BORING
}
1 I
•
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 10-13-99
WI- - 14.0' WD•.S 10.6' A.B. BORING COMPLETED 10-13-99
wt, err acon RIG CME-55 ;FOREMAN DBC
wI- Water Checked 1 Dav A.P.. APPROVED DMIL 'JOB ^ 21995142
LOG OF BORING No. 4 Page 1 0l' I
CLIENT
I ARCHITECT/ENGINEER
Don and Linda Owens 1
SITE Weld County Roads 22 & 19 PROJECT
Weld County, Colorado Preliminary Soil and Percolation Tests
SAMPLES TESTS
O E L •ss' r- —
— '"
—. EI � I ;c z=
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0.5 TOPSOIL 6" HSMI 1155 13 9 I 7I
SILTY SAND = 1
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Very loose to loose - 21ST NR'
—
3ISS 12" 2 20i
5
4 SS 12" 6 24
10.0
10-- ,
SILTY CLAYEY SAND
Tan. moist to wet =
••i•t Loose to medium dense I —
:'; i 15.0 - SC. 5 SS 12" 35 , 15
BOTTOM OF BORING 15- ;Sw1
I I i
I
I
I
I
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES
BETWEEN SOIL AND ROCK TYPES: NSITU.THE TRANSITION MAY BE GRADUAL.
WATER LEVEL OBSERVATIONS BORING STARTED 10-13-99
WL `_' 4.0' W D•I T 2.0' A.B. BORING COMPLETED 10-13-99
WL 1 erracon RIG CME-55 ',FOREMAN DBC
WL R'::tcr Checked 1 Day A.B. APPROVED DML :J013 21995142
A LOG OF BORING No. 5 Page 1 of 1
ARCHITECT/ENGINEER
CLIENT
Don and Linda Owens
SITE Weld County Roads 22 & 19 PROJECT
Weld County, Colorado Preliminary Soil and Percolation Tests
I • SAMPLES TESTS _
O I O s . Ic
O C1 I ?- • ry : to Z=
J I - >- N - 1 C 'IZ 'L-
U DESCRIPTION = cn m j > ZEn I E. to C..
_ E.= ' D . ?
¢ I _ to = I > ua c__J zu 1=
C7
0.5 TOPSOIL 6" _SMI 1 I SS i 18"I 8 4
SILTY SAND
�I'. Brown to tan, moist, loose
1 I I i
11 i 21551 12 3 d, i
3
1
`< tI WEATHERED CLAYSTONE ! 3 I ST! 12"j 7640
✓.� ;: Gray to tan, moist, soft _
4 i SS 1 12"I 36 11
I =
10.0 10—
i CLAYSTONE/SILTSTONE —
,�— --=-._—
Tan to gray, moist, moderately hard _
51 SS.I 12 40 !. 13I
16.0 IS ^
I BOTTOM OF BORING
j I i I
I
THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LLNES
BETWEEN SOIL AND ROCK TYPES: IN-SITU.THE TRANSITION MAY BE GRADUAL.
WATER LEVEL OBSERVATIONS BORING STARTED 10-13-99
WL i= None W.D..Y. 9.3' A.B. BORING COMPLETED 10-13-99
1 err 2con RIG CME-55 FOREMAN DEC
WL ! APPROVED DML '1108 s 21995142
wL �V ter Checked 1 Day A.B.
e
LOG OF BORING No. 6 Page 1 0l' I
..--. CLIENT ' ARCHITECT/ENGINEER
Don and Linda Owens
SITE Weld County Roads 22 & 19 PROJECT
Weld County, Colorado Preliminary Soil and Percolation Tests
SAMPLES TESTS
L:
0 : I I >- '• a EA1 LU
z-
DESCRIPTION " } > Z ? C ZZ •_f
C :n Z >- c -- C(7 H Zii c- ins
' - 0.5 TOPSOIL 6" _SMI 1 I SS 118"' 9 3
SILTY SAND
Brown to tan, moist, loose _ I
— 2 ' ST: 12" 30
3I SS . 12" 4 31
7.0 —
i — 4 i 5T; 12"' 7 120 i 2455
SANDY LEAN CLAY
Tan, moist. stiff —CL. 5 SS : 12" 9 17-'
10—
_
'1, . 11.5
WEATHERED CLAYSTONE • —
•:<#.•; #-: Gray co tan, moist, soft _ I
;cij i 15.0 - 6 SS 12" 30 18 , 810
BOTTOM OF BORING 1:
I '
I
I
THE STRATIFICATION LLNES REPRESENT THE APPROXIMATE BOUNDARY LLNES
BETWEEN SOIL AND ROCK TYPES: IN-SITU,THE TRANSITION MAY BE GRADUAL.
WATER LEVEL OBSERVATIONS BORING STARTED 10-13-99
WL None W.D.'= None A.B. BORING COMPLETED 1043-99
wt. Ferracon RIG CME-55 I FOREMAN DBC
WL Water Checked 1 Day A.B. APPROVED DML {JOBa 21995142
DRILLING AND EXPLORATION
DRILLING & SAM PUNG SYMBOLS:
y' : Ring Sampler - 2.42" I.D. PS : Pston ample
: Split Spoon - 1 '' I.D.. 2" O.D., unless otherwise noted WS Wash Sample
Thin-Walled Tube — 2-1/2" I.D.. unless otherwise noted
PA : Power Auger FT�� :: i Fch Tail Sit
h k ai[
HA : Hand Auger RS : Sulk Sample
DB : Diamond Bit = 4". N. B ES : Pressure Sar i Meter
AS : Auger Sample PMPC : Dutch rCcine
e M
HS : Hollow Stem Auger WB : Wash Sore
Penetration Test: Slows per foot of a 140 pound hammer fa:iina 33 inches on a 2-inch O.D. split spoon. escert
where noted.
WATER LEVE?MEASU REM ENT SYMBOLS: WS While Sampling
WINL . Water Level WS : While Sarong
CC : Wet Cave Cv in in SCR : Before Casing Removai
.CI : Dry ACR : After Casting Removai
A8 After Boring
:he borin s at the time indicated. In cer:icus
Water levels indicated on the boring legs are the levels measurer n 9
soils. the indicated levels may reflect the location of arounc.later. In low permeability soils, the accurate
determination of grounc.vater levels is not possible with only sncr. term obserfations.
DESCRIPTIVE SOIL CLASSIFICATION:
Soil Classification is baser on the Unified Soii Gassiricaticn syst=:- and the ASTM Desnations D-2487 anc :-734S.
,Ve!cn: -- a:ned on a #200 sieve:'they.are describer as:
boulders.Coarse cobbles.
Soils have more n i _Gr0% of their c^ :h - 50% of their cry •,veicnt retainer or. a =23:3
theyyo re d gravel or sand. Fine Grained Soils have :zss they are siicntly ?ias-:c or non-pies:It. '.:alcr
sieve: are described as: clays. if they are ?:as:.c. anc s:.a � /
constituents may de acted as modifiers anc minor cons;ituera m be added accorc.nc :o the-relative crcrc-:ers
defined on the bass of their relative .. -.<_a
�yaser on Aram sizai yr. sedition
iis t basis f : coarse a consistency_
- `r
msity anc fine grainer bolls on the basis or :heir consstency- can clay mite sano. :race grave. s
a:!tv sand. trace crave. medium dense (SW.
CONSISTENCY CF FINE-GRAINED SOILS: REa TIVE DENSITY OF
Unconfined Compressive
COARSE-GRAINED SOILS:
Strength. Cu. psf Consistency '1-Blow sift. Relative Density
-3 Very Loose
< 500 Very Soft ' „ Loose
500 - 1 .000 Soft ' O_-a Medium Dense
1 .001 - Z.Oc0 Medium
2.001 - 4.000 Stiff 30- 9 Dense
4.001 - 8.000 Very Stiff 50-80 Very Dense
8,001 -16.000 Very Hard 50' Extremely Dense
RELATIVE PROPORTIONS OF GRAIN SIZE TEr'cPA INOLOGY
SAND AND GRAVEL
Descriptive Term(s) Major Component
(of Components Also Percent of of Sample Size Range
Weight guiders Over 12 in. (CCGr, m)
Present in Samoief Dry g Cobbles 12 in. to 3 in.
Trace 15 - Zo` 5 m
(300mm to 75m
With 'ravel 3 in. to #4 sieve
Mocifier ' (75mm to 4.7 5.mr
30 — Sane #4 to #200 sieve
R!^ 4T1VE PROPORTIONS OF FINES -4.75mmto .07.7.r:—::
Silt or Clay Passing #200 Sievt
Descriptive Tertnls) (0A75mmi I
(of Components Also Percent of
Present in Sampiei Dry Weight
Trace c 5
With 5 - 12
`.tccifier ' 12 lrerraCcn
\
GENERAL NOTES
Sedimentary Rock Classification
DESCRIPTIVE ROCK CLASSIFICATION:
Sedimentary racks are composed of cemented clay, silt and sand sized particles. The most
common minerals are clay, quartz and calcite. Rock composec primarily of calc:te is called
limestone: rock of sand size grains is called sandstone, and rock of clay and silt size grains
is called mudstone or claystone. siltstone.or shale. Modifiers such as snaly, sandy.dolomitic.
calcareous.carbonaceous.etc.are used to describe various constituents. Examples: sandy
shale; calcareous sandstone.
LIMESTONE Light to dark colored. crystalline to fine-grained texture. composed or CaCo]. reacts readily
with HCI.
DOLOMITE Light to dark colored, crystalline to fine-grained texture. composed of CaMg(CO )2, harder
than limestone. reacts with HCI when powdered.
CHERT Light to dark colored,very fine-grained texture, composed or micro-crystalline cuartz(Si02).
brittle, breaks into angular fragments, will scratch glass.
SHALE Very fine-gr m.ed texture. composed or consolidated silt or clay,-beaded in thin layers. The
unlaminatec equivalent is frequently referred to as siltstone. claystone or mudstone.
SANCSTCNE Usually !ignt colored.coarse to fine texture.composed of cemented sand size grains of quartz.
feldspar, etc. Cement usually is silica out may be such minerals as calcite.iron-oxide,or some
other carachate.
CONGLOMERATE Rounded roc:: fragments or variable mineralogy varying in size tram near sane tc ooulder size
but usually ceccie to cobble size(t inch to 6 inches!.'Cemented together with various cemen-
ting agents. ?.eco:a is similar out composed of anguiar. frac:urea rack partic:es cemenrec
together.
PHYSICAL PROPERTIES:
DEGREE OF `,WEATHERING BEDDING AND JOINT CHARACTERISTICS
Slir_.ht Slight deCOm oCSEtiOn of parent Bed Thickness Joint Spacing Dimensions
material on ;aims. May be color Very Thick Very Wice >10'
change. Thick Wide - 10'
Medium Mocerately Close - 3'
Macerate Some decomccsizicn and color Thin Close
change througnc:.:. Very Thin Very Close - 2"
High Rock highly decomposed.may be ex- Laminated —
tremely broken. Bedding P!ane A olane dividing sedimentary rocks of
the same cr different lithology.
HARDNESS AND DEGREE OF CEMENTATION joint Fracture in rock. generally more or
less vertical or transverse to bedding,
Limestone and Dolomite: along which no appreciable move-
Hard Difficult to scratch with knife. ment has occurred.
Moderately Can be scratched easily with knife. Seam Generally applies to bedding plane
Hard cannot be scratched with fingernail. with an unspecified degree or
Soft Can be scratched with fingernail. weathering.
Shale. Siltstone and Claystone SOLUTION AND VOID CONDITIONS
Hard Can be scratched easily with knife,
cannot be scratched with fingernail. Solid Contains no voids.
Moderately Vuggy (Pitted) Rock having small solution pits or
Hard Can be scratches-with fingernail. cavities uo to 1/2 inch diameter. fre-
:uently with a mineral lining.
Soft Can be easily tented but not molded
with fingers. Porous Containing numerous voids.pores.or
other openings. which may or may
Sandstone and Conglomerate not interconnect.
Well Capable of scratching a knife blade. Cavernous Containing cavities or caverns.some-
Cemented times quite large.
Cemented Can be scratched with knife.
Poorly Can be broken apart easily with
Cemented ringers.
lerracon
(
UNIFIED SOIL CLASSIFICATION SYSTEM
LSoil Classification
'
Criteria for Assigning Group Symbols arc Grouc Names Using Laooratory Tests Group Group Name'
Symbol
Crean Gravels Cu a a and 1 s Cc s 3° OW Well-graded gravel'
Core than 50%ined Soils Gravels
—
Mom than ev retained on More than 50% of coarse mss than 5".'° tines` Cu < a and/or 1 > Cc > 3` GP Poorly graded gravel'
No.200 sieve traction retained on
No. s sieve Fines o:assily as ML Jr MH GM Silty gravel`'''"
Gravets...nth Fines
More than '2% fines' Fines classify as CL or CH GC Clayey gravel'.a"
Sands Crean Sands ° Cu a d and I s Cc s 3` SW Well-graded sand'
50% or more or coarse _ss than 5% fines Cu < d and/or 1> Cc > 3e. SP Poorly graded sane'
traction passes
No.s sieve Fines classify as ML or MH SM Silty sands'"'I
Sands '.vim Fines
More than :2% fines° Fines classify as CL or CH SC Clayey sands'"-I
Fine-Grained Soils Silts aria Clays narganic
?I > 7 an° aims on or above"A'line- CL Lean clayL L M
50% or mare passes the Liquid limit less than 50 PI < 4 or plots below "A" line' ML Sill'`'mNo.200 sieve PI
L m.
Liquid limit — oven dried Organic may '
organic < 0.75 OL
LIdWp limit — not dried Organic silt'u M.°
Silts and Clays -norganic PI plots on or aoove "A" line CH Fat clay'=•"
Liquid limit 50 or more PI ]lots oeimv "A" line MH Siastic silt'['L M
LIQUIo limit — oven urea Organic clay''/M o_
organic < 0.75 OH
Liquie limit — not dne0 Organic silt'1-a,=
Nighty organic soils
?-manly Organic-natter'. :ark in color.and organic°°or Pi Peat
IO- ,z `If soil contains '5:0 29% olus No. 200. adc
`Based on the material passing the 3-in. eV" = T C - M 'with sari°"or-.vialgravel'.'whicneyef is
75-mini sieve. o = 7.p x D,p predominant.
,..""'"3't field sample contamec cbbcles or 'If soil contains ≥ 5% sand. add "with Banc" :o -If soil contains ≥ 30°': °lust No.200
:ouldefs. Jr both. add "wan cObales or group name. predominantly sane. 100 -salty" to grout)
:cowers.or bum" to gonerotto name. 'If fines classify as CLML use dual symbol GC- flame.
°Gravels with 5 to 12% lines redulre dual GM. or SC-SM. 'Alf soil contains ≥ 30% plus No. 200.
symbols: ";f fines are organic. sod ^Kith organic tines 10 predominantly _ravel. sod -gravelly" to gratis
GW-GM -graded gravel with slit grouo name. name.
GPGM-GC coorty gradacted ag al gravel ww clay
GP-GM 000rty gadeQ ',vim silt 'If soil contains ≥ '5% gravel. add -.vim gravel" to 'i of ≥ 4 ano plats on cr aoove-A" line.
GP-GC poorly graded gravel with clay group name. :PI < 4 or plots -slow 'A' line.
°Sands with 5 to 12% fines recuire cuat 'If Atteroerc limits o:ct in shade° area. soil is a C_ '?I olots on or accve line.
symbols: ML silty clay. :PI plots below line.
SW-SM well-graded sane with silt
SW-SC well-graded sand with clay
SP-SM poorly grade° sand with silt
SP-SC poorly graded sari°with clay
-e0
For classification of fine-grained soils /
•
and fine-grained traction of coarse- / •
50;`grained soils /4 /
I Equation of "A"- line .• - N.C� •
Horizontal at PI = a to LL 25.5- ,J i ID
\'
E: then PI = 0.73 ILL•201 , 'P'
—
w -0 __uation of -"J" - line /' �0` —
p : 'lertic3i at LL = 16 to PI = , Q
Z :hen PI - 0.9(LL-a1 /
>. 30i /
/
_
U / '
/ O�R
to 20 , r '..
a // Goo MH :a OH
/
to '
/-
CL • ML MLoaOL
I -
0; '0 '5 20 30 _0 50 50 70 =0 90 'co rto
LIQUID LIMIT (LL)
•
11 rrecon
APRIL 2003
PRELIMINARY
DRAINAGE REPORT
GLORALOMA ESTATES
PUD
CHANGE OF ZONE
SUBMITTAL
Prepared for.
DON AND LINDA OWENS
8585 WCR 22
Fort Lupton, Colorado 80621
(303)
Prepared by.
PICKETT ENGINEERING, INC.
808 8th Street
Greeley, Colorado 80631
(970)
ENGINEER'S CERTIFICATION
This Preliminary Drainage Report for the Gloraloma Estates PUD Change of
Zone Application to Weld County, Colorado, has been prepared under my direct
supervision upon request of the property owners, expressly for their use.
Gregory E. Bowdish, PE Date
Colorado Registered Professional Engineer#35533
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