HomeMy WebLinkAbout20090732.tiff • •
�� HIGH PLAINS ENGINEERING & DESIGN, LLC
• 721 4th STREET, SUITE D, FORT LUPTON,CO 80621 • PHONE: (303)-857-9280• FAX: (303)-857-9238
SUBSURFACE INVESTIGATION AND FOUNDATION
RECOMMENDATIONS
Prepared For:
Turnpike, LLC
28667 Weld County Road 20
Keenesburg, CO 80643
Job Site Located At:
Steel Building #1 - North
A part of the NW1/4 of Section 9
• TIN, R63W of the 6th P.M.
Weld County, CO
November 7, 2007
JOB #07-1557
33548 r
Todd M. Schroeder P.Ei,:3 �5f4p4,7
EXHIBIT
2009-0732
AGREEMENT OFIRJRPOSE AND DISCLAIM:
The parties specifically agree and contract that the purpose of the provided
subsurface investigation is to test, analyze, and provide geotechnical
• recommendations for the proposed building and/or residence. This report presents a
description of subsurface conditions encountered at the site, recommended
foundation system, and design and construction criteria influenced by the subsurface
conditions. The opinions and recommendations presented in this report are based on
the data generated during this field exploration, laboratory testing, and our
experience. A foundation design sealed by a Professional Engineer is required to
obtain a building permit but is not included in this report.
The parties specifically agree that High Plains Engineering & Design, LLC has not been
retained nor will they render an opinion concerning environmental issues, hazardous
waste or any other known and or unknown conditions that may be present on the job
site, since this is not our area of expertise.
LOCATION AND SITE CONDITIONS:
This report represents the results of the data obtained during the subsoil investigation
for the proposed steel building at a part of the NW 1/4/4 of Section 9, Ti N, R63W of the 6th
P.M., Weld County, CO.
The proposed building site is presently vacant. The site is reasonably level with
• approximate slopes of 3.5% to the Northwest. The lot appears to be well drained with
no erosion evident.
The dept s of foundation construction are anticipated to range from two (2) to four (4)
feet belo grades that existed at the time of this investigation. It is anticipated that
final grad s may be adjusted to accommodate drainage and construction depths. It
is recom ended that we review the final grading plan to determine if any revisions to
the reco mendations presented in this report are necessary.
SUBSOIiL CONDITIONS:
Three, four inch diameter holes were drilled to a depth of twenty five feet at the
building site on November 5, 2007, as shown on the attached site map. Samples of
the soil were taken at two-foot intervals. These samples were analyzed in the field and
laboratory to determine the characteristics of the soil (per Unified Soil Classification
System) for identification and foundation design. In general, the soil profiles in test
holes # 1, #2 & #3 indicated Sandy Silt (SM) to a depth of 9 feet, underlain by Sandy
Clay (SC) to a depth of 15 feet. Clay with Medium Plasticity (CL) exists from 15 feet to
25 feet. The Standard Penetration Test similar to ASTM D1586 showed 12 blows for 12-
inch penetration at a depth of 4 feet, and 15 blows for a 12-inch penetration at a
• depth of 9 feet. Please note that actual subsurface soil conditions may vary between
samples and locations tested.
Job#07-1557 Steel Bldg#1-North Page 2 of 8
One-dimensional swell,•nsolidation tests were perform* on selected samples to
evaluate the expansive, compressive and collapsing nature of the soils and/or
bedrock s rata. These tests indicated a consolidation potential of 0.7% at a depth of 4
feet, and a consolidation potential of 0.8% at a depth of 9 feet. The soils in this report
• were cies ified using the American Society of Testing Materials (ASTM) procedures.
The geot chnical practice in State of Colorado utilizes a relative scale to evaluate
swelling ( xpansion) potentials. When a sample is wetted under a surcharge pressure
of 500 po nds per square foot (psf), the measured swell is classified as low, moderate,
high, or ery high. The following table represents the relative classification criteria.
Please n to that the measured swell is not the only criteria for slab-on-grade
recomme dations and additional factors are considered by the engineer when
evaluatin the risk for slab-on-grade construction.
TABLE I
SLAB PERFORMANCE REPRESENTATIVE
RISK CATEGORY PERCENT SWELL
(500 PSF SURCHARGE)
LOW 0 TO<3
MODERATE 3 TO<5
HIGH 5 TO<8
VERY HIGH ≥8
Source: Colorado Association of Geotechnical Engineers, Guideline for Slab Performance
• Risk Evaluation and Residential Basement Floor System Recommendations (Denver
Metropolitan Area), 1996
GROUNDWATER:
Groundwater levels were not recorded at the time of our field investigation; however,
it may be possible for groundwater to exist at construction depths at a later date. The
groundwater can be expected to fluctuate throughout the year depending on
variations in precipitation, surface drainage and irrigation on the site. The possible
presence of shallow bedrock/dense clays beneath the surface is favorable for the
formation of "perched" groundwater. We recommend that the bottom of the
basement or crawlspace excavations be maintained at least 4 feet above the free
groundwater level.
The ground water levels recorded represent the free, static water levels after
equalization of hydrostatic pressures in the test hole borings. It is possible that the
groundwater levels recorded in the test hole borings may not be present at those
levels in the foundation excavations. Flow rates, seepage paths, hydrostatic pressures,
seasonal groundwater fluctuations, water quality and other factors were not
determined in this investigation. A program, which may include special well
• construction, test procedures, long-term monitoring program and analysis would be
necessary to determine these factors.
Joh#07-1557 Steel Bldg#1-North Page 3 of 8
FOUNDATION REODMMENDATIONS: •
The Sandy Silt (SM) material has a bearing strength of 1250 pounds per square foot
(psf) and an equivalent liquid pressure of 35 pcf. We recommend the use of a
• continuo s spread footing, due to the low expansion-consolidation potential of the
analyzed soils. The foundation must be constructed at the location in which soils
investiga on was performed.
All loose nd disturbed soil shall be removed before placing of the concrete for the
foundati n. The bottom of the foundation shall be a minimum of 30" below final
grade (or that required by local iurisdiction; whichever is greater) for frost protection.
Soil settlement resulting from the assumed structural loads is estimated to be one inch
or less. Soil expansion at this site may be up to one inch in some areas. No foundation
wall is to exceed twenty-five feet in length without utilizing buttresses or counterforts
unless otherwise designed by the foundation engineer.
Engineered steel reinforcements shall be required in the footings and foundation walls.
This will give walls or footing beams the strength to span or bridge over any loose or
soft pockets of soil that may develop during construction.
Owners shall be made aware of all contents of this report, and the fact that water
accumulation around foundation elements is the primary cause of distressed
foundations.
• To help prevent secondary damage that could be caused by slab movement, the
following construction techniques are additional recommendations for the foundation
construction.
SLAB ON GRADE CONSTRUCTION:
1 . When and where slabs-on-grade are chosen and the owners are willing to
accept the risks associated with slab movement, the following
recommendations are to be followed:
a.)Slabs should be constructed as "free floating". Positive separations and/or
isolation joints should be provided between slabs and all foundation walls,
bearing members (columns), plumbing and utility lines. Isolation may be
achieved with 1/s inch expansion material or by sleeving. Vertical movement
of the slabs should not be restricted.
b.) Eliminate plumbing under slabs where feasible. Where such plumbing is
unavoidable, it should be thoroughly pressure tested during construction.
c.) Place the slab directly on the undisturbed natural soils, or properly
• compacted fill soil. Floor slabs and footings should not be constructed on
Job#07-1557 Steel Bldg#1-North Page 4 of 8
frozen sub gr.. Slabs should be reinforced vlikrebar, wire mesh or fiber
mesh to help control crack separation.
2. Provide frequent scoring of the slabs to provide joints for controlled cracking of
• the slab. Control joints should be placed to provide approximate slab areas of
1501square feet, with a maximum dimension of thirteen feet between joints. The
de th of sawed control joints should be 1/4 of the slab thickness. Install a good
qu lity sealant in these joints to prevent surface discharges of liquid from
pe etrating slab sub grades.
3. The soils that will support the concrete slabs should be kept moist during
construction by occasional sprinkling of water. The soils should be moistened to
+/- 2 % optimum moisture within 48 hours of pouring the slabs. This procedure will
help maintain the moisture content of the underlying soil. **Heavy watering or
polling of any kind next to the foundation or within the backfilled area is not
recommended.**
4. A minimum void or clear space of 3 inches should be provided at or near the
bottom of all non-bearing partitions. In finished room areas, all drywall and
paneling should be stopped approximately 3 inches above the top of the slab.
This will allow some space for upward movement of the slab before pressures
are applied to the wall and upper levels of the structure. The builder should
provide a Yz inch space at the bottom of all doorjambs to allow for limited
movement of the floor slab. The owner is hereby notified that it is their
responsibility to maintain these void spaces.
• 5. If a forced air heating system is used and the furnace is located on the slab, we
recommend provision of a collapsible connection between the furnace and the
ductwork. In the event a hot water heating system is used, the piping should not
be laced beneath the concrete slab.
BACKFILL AND SURFACE DRAINAGE:
The foundation and retaining walls must be well cured and well braced prior to
backfilling.
Any soil disturbed adjacent to bearing foundation components are to be re-
compacted to a minimum of 85% Standard Proctor Density (ASTM D698). Backfill that
bears concrete slabs shall be compacted to 95% Standard Proctor Density (ASTM
D698). Mechanical compaction methods shall be utilized, (water-flooding techniques
are strictly prohibited). See Compaction Section for more information regarding
compaction requirements and techniques.
Proper drainage away from the foundation walls shall be provided. The owners are
advised to immediately fill any settled areas to eliminate water accumulation near the
• foundation. A minimum slope of 12 inches in the first 10 feet from the perimeter of the
building is recommended. Roof downspouts and sill cocks should discharge into long
concrete splash blocks (5 feet long min.) or into gutter extensions to deposit runoff
Job#07-1557 Steel Bldg#1-North Page 5 of 8
water beyond the lin. of the backfill soil near the•undation walls. Plastic
membranes should not be used to cover the ground surface immediately surrounding
the structure; geotextile fabric should be utilized for weed control. Any drainage
water from uphill shall be diverted around the structure,
• Sprinkling systems should not be installed or direct water to be within 10 feet of the
foundation. The owner/builder is also advised that irrigation lines can leak and/or
break, resUlting in release of excessive amounts of water near the foundation, This can
cause dcpnage to slabs and foundation walls. WATER ACCUMULATION AROUND
FOUNDATION ELEMENTS IS THE MAIN CAUSE OF DISTRESSED FOUNDATIONS.
COMPACTION:
Placing Fill: No brush, sod, frozen material, perishable material, unsuitable material, or
stones of four inches or greater in maximum dimension shall be placed in the fill. The
distribution of the material on the fill shall be such as to avoid the formation of layers of
materials differing substantially in characteristics from the surrounding materials. The
materials are to be delivered to the backfill surface at a uniform rate, and in such
quantity as to permit a satisfactory construction procedure. Unnecessary
concentration of backfill machinery travel tending to cause ruts and other hollows
more than six inches in depth, are to be re-graded and compacted. After dumping of
fill material on the backfill surface, the material is to be spread by approved methods
in approximately 6 inches compacted thickness.
• Moisture Control: The material in each layer shall be compacted by rolling and shall
contain the optimum moisture required for maximum compaction, as nearly
practicable and as determined by the soils engineer. The moisture content shall be
uniform throughout all layers. If in the opinion of the soils engineer it is not possible to
obtain moisture content by adding water on the fill surface, the contractor may be
required to add the necessary moisture to backfill material in the borrow area.
Compaction: When the moisture condition and content of each spread layer is
satisfactory, it shall be compacted by a method approved by the soils engineer to
95% ASTM D698 (Standard Proctor Density) for slab areas, and 98% ASTM D698 for
footing and/or pad areas. A Standard Proctor test is to be performed for each typical
fill material and frequent tests of the density of the fill must be taken.
In general, to compact cohesion-less free-draining materials, the above guidelines
also apply.
When compacting cohesion-less free-draining materials such as gravel and sand, the
materials shall be deposited in layers and compacted by treads of a crawler type
tractor, surface of internal vibrators, pneumatic or smooth rollers, power or hand
tampers, or by any other means approved by the soils engineer. The thickness of the
horizontal layers after compaction is not to exceed 6 inches compacted thickness if
• compaction is performed by tractor treads, surface vibrators or similar equipment, or
not more than penetrating length of the vibrator head if compaction is performed by
internal vibrators. When the moisture content and condition of each spread layer is
Job#07-1557 Steel Bldg#I-North Page 6 of 8
satisfactory, it shall be "Impacted by a method appro. by the soils engineer to
95% ASTM D1557 (Modified Proctor Density) for slab areas, and 98% ASTM D1557 for
footing and/or pad areas.
• RADON:
Most counties in Colorado have average radon levels (measured in home) above the
U.S. EPA recommended "action level" of 4 picocuries per liter of air (pCi/1). Results of
a 1987-1968 EPA-supported radon study for Colorado indicated that granite rocks, in
particular, generally have elevated levels of uranium. These rocks have the potential
of produding higher than average levels of radon gas in the home. Increasing
ventilation of basements and crawl spaces and sealing of joints can mitigate build-ups
of radon gas. This mitigation is best implemented during the design and construction
phases of residences.
The U.S. EPA {www.epa.gov/iaq/radon} is a good source for additional radon
information.
CONSTRUCTION DETAILS - GENERAL COMMENTS:
In any soil investigation, it is necessary to assume that the subsurface soil conditions do
not vary greatly from the conditions encountered in the field and laboratory testing.
The accompanying design is presented using best professional judgment based on the
limits of the extent of testing commissioned by the client. Our experience has been
• that at times, soil conditions do change and variations do occur. These may become
first apparent at the time of excavation for the foundation system.
"If soils c nditions are encountered which appear different from the test borings as
presente in this report, it is required that this office be called to make an observation
of the o n excavation rior to lacin the footin s. The cost of this observation is not
part of thi report."
This proje t should be constructed by a qualified contractor with experience in similar
projects. The owner/builder is advised to observe and document the construction
process t ensure the construction is performed in accordance with the design
drawings nd technical specifications.
This report does not address general hillside stability, landslide potential, and/or other
natural hazards. Several areas in the Colorado Front Range have known geologic
hazards associated with them. We recommend that readers of this report educate
themselves further as to the existence of geologic hazards on or around their specific
property of interest. The Colorado Geologic Survey {www.geosurvey.state.co.us or
303-866-2611} is a good source for publications (maps, reports, etc.) dealing with
specific geologic issues and/or issues related to specific geographic areas. The
foundation and retaining walls must be well cured and well braced prior to backfilling.
•
Job#07-1557 Steel Bldg#I-North Page 7 of 8
DISCLAIMER: •
We do n It guarantee the performance of the project in any respect, but only that our
engineeri g work and judgments rendered meet the standard care of our profession.
• The pres nce of underground workings (e.g. coal mines) and subsidence potential
from any workings was not part of this investigation. The owner should contact the
State an County agencies to determine if mining has been conducted in the area
and if an precautions are recommended.
THE PARTIES SPECIFICALLY AGREE THAT HIGH PLAINS ENGINEERING & DESIGN, LLC, HAS
NOT BEE RETAINED NOR WILL THEY RENDER AN OPINION CONCERNING ANY
ENVIRON ENTAL ISSUES, HAZARDOUS WASTE OR ANY OTHER KNOWN OR UNKNOWN
CONDITI NS THAT MAY BE PRESENT ON SITE.
DUE TO C ANGING TECHNOLOGY, BUILDING CODES AND CITY/COUNTY REQUIREMENTS,
THIS SOIL',REPORT MUST BE USED WITHIN ONE YEAR OF THE DATE ON THE FRONT OF THE
REPORT OR MUST BE REVISED.
•
•
Job#07-1557 Steel Bldg#I-North Page 8 of 8
/ 0
//
%/ 1
• //. 2
// 3
//
lowcounts 12/12 /7/
/ 4 SANDY SILT (SM)
/
// 5
//
i//, 6
//
// 7
//, 8
'//
Dlowcounts 15/12 `' 9
\\ 10
11
• \\ 12 SANDY CLAY(SC)
\; 13
\\ 14
2\ 15
16
17
18
19
20 CLAY WITH MEDIUM PLASTICITY(CL)
21
22
7 23
24
/ 25
• SOIL PROFILE
• •
t HIGH PLAINS ENGINEERING & DESIGN, LLC
721 4th STREET, SUITE D, FORT [UPTON, CO 80621 PHONE — (303) 857-9280 FAX — (303) 857-9238
• 12% - , . .
10% —
8% - .
6% .
4% "
2% . . . .
0% 1-----__
4% ADDED —
-0% .
8%
- !0%a _ _ -
100 500 1000 2000 3000 10000
GRAPH Of FOUR FOOT DEPTH
SOIL TYPE
f iOl L# DEPTH ' IIILI P.L. 'I. EXPANSION CONSOLIDATION
I 4' I nor-plastic 0-7 SANDY SILT(SM)0 12% _ _,
(0% •
8% ---- - ) -
6%
4% .
2% L.
0% •. _ .
-2% 4420 r • T -
ADDED
-4%
-8% .
-10%
, 1
100 500 1000 2000 3000 10000
GRAPH OF NINE FOOT DEPTH
X % SOIL TYPE
BOLE N 1-DEPTH L L. P.L. P.I. 'EXPANSION ' CONSOLIDATION
` I 9' norl-platic 0.5 SANDY CLAY(SC)
• JOB NaNO 07,1557 JOB LOCATION:
DATE: 11O7/07 PART Of THE NW]/4 Of SECTION 9
DRAWN: Jasmn TIN.RG3W OF 1 HE 6TH P.M.
CHECKED: WELD COUNTY.CO
I
• •
- ' HIGH PLAINS ENGINEERING & DESIGN, LLC
ii
YNVN
21 4th STREET, SUITE D, FORT LUPTON, CO 80621 PHONE - (303) 857-9280 FAX - (303) 857-9238
FOUNDATION GRADING DETAIL
5' MIN.
-DECORATIVE GRAVEL
OR STONE AREA
a I ,
GRADE
z
METAL OR WOOD EDGE
00 W I/2" SPACE AT
BOTTOM TO ALLOW FOR
THE RELEASE OF WATER
A\
`FOUNDATION WALL _GEOTEXTILL FABRIC
NOTE:
I . PROVIDE A MINIMUM OF I 2" IN THE
FIRST I 0-0' FROM THE BUILDING ( I 0%)
2 . DOWN SPOUTS AND EXTENSIONS SHOULD
• EXTEND BEYOND THE GRAVEL OR STONE AREA
5 ILI- N/
ska
Part of the NW%4 of Section 9
TIN, KG3W of the Gth P.M.
Weld County, CO
•
1358' S . 1010 2
< >4
P5-7A
as I n
3
Steel Building Site#I -North
a3a
• Access — ——centerline of access roac
1Dfi
n
t 90
A
� 9a
A
Steel Building Site#2 -South
LEGEND
Percolation Test Hole All locations shown above are based on specific Information furnished
by others or estimates made in the field by High Plains Engineering &
Percolation Profile Hole Design personnel. The locations, distances, directions, etc. are not
the result of a property survey but are approximations and are not
a.—Soil Profile Hole warranted to be exact. It is the owner/builder's responsibility to
define property boundaries and ensure all onsite Improvements are
located within the platted site and out of inappropriate easements.
All distances are to be verified prior to excavation.
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