HomeMy WebLinkAboutZIEGLER-HARVEST PARK - FDP - FDP140022 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGEOTECHNICAL EXPLORATION REPORT
5305 ZIEGLER ROAD – SOUTH/LOT 2
FORT COLLINS, COLORADO
EEC PROJECT NO. 1122052
Prepared for:
Architecture West, LLC
4710 South College Avenue
Fort Collins, Colorado 80525
Attn: Mr. Stephen Steinbicker (Steve@architecturewestllc.com)
Prepared by:
Earth Engineering Consultants, Inc.
4396 Greenfield Drive
Windsor, Colorado 80550
4396 GREENFIELD DRIVE
WINDSOR, COLORADO 80550
(970) 545-3908 FAX (970) 663-0282
www.earth-engineering.com
July 10, 2012
Architecture West, LLC
4710 South College Avenue
Fort Collins, Colorado 80525
Attn: Mr. Stephen Steinbicker (Steve@architecturewestllc.com)
Re: Geotechnical Exploration Report
5305 Ziegler Road – South Parcel/Lot 2
Fort Collins, Colorado
EEC Project No. 1122052
Mr. Steinbicker:
Enclosed, herewith, are results of the geotechnical subsurface exploration completed by
Earth Engineering Consultants, Inc. (EEC) personnel for the referenced project. As part
of this exploration, six (6) soil borings extending to depths of approximately 20 to 30 feet
below existing site grades were drilled on this portion of the property to develop
information on existing subsurface conditions. This study was completed in general
accordance with our revised proposal dated June 8, 2012.
The property at 5305 Ziegler Road consists of an approximate 3.75 acre parcel split into a
north parcel (Lot 1) located north of County Fair Lane and a south parcel (Lot 2) located
south of that roadway. The south portion of the development will include four (4) 6-plex
multi-family buildings with associated drive and parking areas. The multi-family
buildings are expected to be wood frame with light foundation and floor loads. Those
structures are expected to be constructed on full basements. We anticipate small grade
changes will be required to establish final site grades.
In summary, the subsurface soils encountered in the test borings completed on the south
parcel included lean clay soils with varying amounts of sand extending to depths of
approximately 10 to 16 feet below existing site grades and underlain by
siltstone/sandstone/claystone bedrock. The overburden lean clays showed moderate to
high moisture contents with corresponding medium stiff to stiff consistency. The
underlying bedrock was highly weathered near surface becoming less weathered with
GEOTECHNICAL SUBSURFACE EXPLORATION REPORT
5305 ZIEGLER ROAD – SOUTH PARCEL/LOT 2
FORT COLLINS, COLORADO
EEC PROJECT NO. 1122052
July 10, 2012
INTRODUCTION
The geotechnical subsurface exploration for the proposed south parcel (Lot 2) at 5305
Ziegler Road in Fort Collins, Colorado, has been completed. Six (6) soil borings were
completed at predetermined locations on the south parcel to develop information on existing
subsurface conditions. The borings were extended to depths of approximately 20 to 30 feet
below present site surface grade. Individual boring logs and a diagram indicating the
approximate boring locations are included with this report.
The development parcel at 5305 Ziegler Road includes approximately 3.75 acres divided as a
north parcel (Lot 1) located north of County Fair Lane and a south parcel (Lot 2) located to
the south of that roadway. County Fair Lane will be constructed as a part of this
development. Four (4) 6-plex multi-family structures will be constructed on the south
parcel. Those structures are expected to be wood frame with light foundation loads
constructed on full basements. Foundation loads for those structures are expected to be less
than 3 kips per lineal foot for continuous wall loads and less than 100 kips for column loads.
Small grade changes are expected to develop the final site grades in the vicinity of the
proposed buildings. Paved drive and parking areas will be constructed as a part of the
proposed development.
The purpose of this report is to describe the subsurface conditions encountered in the
borings, analyze and evaluate the test data and provide geotechnical recommendations
concerning design and construction of foundations and support of floor slabs and pavements
EXPLORATION AND TESTING PROCEDURES
The boring locations were selected in collaboration with Architecture West and located in
the field by Earth Engineering Consultants, Inc. (EEC) personnel by pacing and estimating
angles from identifiable site references. The approximate locations of the borings are
indicated on the attached boring location diagram. The location of the borings should be
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EEC Project No. 1122052
July 10, 2012
Page 2
considered accurate only to the degree implied by the methods used to make the field
measurements.
The test borings were completed using a truck mounted, CME-45 drill rig equipped with a
hydraulic head employed in drilling and sampling operations. The boreholes were advanced
using 4-inch nominal diameter continuous flight augers. Samples of the subsurface materials
encountered were obtained using split-barrel and California barrel sampling procedures in
general accordance with ASTM Specifications D1586 and D3550, respectively.
In the split-barrel and California barrel sampling procedures, standard sampling spoons are
driven into the ground by means of a 140-pound hammer falling a distance of 30 inches. The
number of blows required to advance the split barrel and California barrel samplers is
recorded and is used to estimate the in-situ relative density of cohesionless soils and, to a
lesser degree of accuracy, the consistency of cohesive soils. In the California barrel
sampling procedure, relatively undisturbed samples are obtained in removable brass liners.
All samples obtained in the field were sealed and returned to the laboratory for further
examination, classification, and testing.
Laboratory moisture content tests were completed on each of the recovered samples. In
addition, the unconfined strength of appropriate samples was estimated using a calibrated
hand penetrometer. Atterberg limits and washed sieve analysis tests were completed on
selected samples to evaluate the quantity and plasticity of the fines in the subgrade.
Swell/consolidation tests were completed on selected samples to evaluate the potential for
the subgrade materials to change volume with variation in moisture content and load.
Soluble sulfate tests were performed on selected samples to evaluate the potential for sulfate
attack on site cast concrete. Results of the outlined tests are indicated on the attached boring
logs and summary sheets.
As a part of the testing program, all samples were examined in the laboratory by an engineer
and classified in accordance with the attached General Notes and the Unified Soil
Classification System, based on the soil’s texture and plasticity of the soil. The estimated
group symbol for the Unified Soil Classification System is indicated on the boring logs and a
brief description of that Classification System is included with this report. Classification of
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EEC Project No. 1122052
July 10, 2012
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the bedrock was based on visual and tactual observation of disturbed samples and auger
cuttings. Coring and/or petrographic analysis may reveal other rock types.
SITE AND SUBSURFACE CONDITIONS
The proposed development is located on the west side of Ziegler Road, north of Kechter
Road in Fort Collins, Colorado. The development property was formerly part of the Ruff
Feedlot and still contains several outbuildings. Most recently, the property has been used for
truck and miscellaneous storage. We understand site structures will be razed to
accommodate the planned multi-family development. Site drainage is generally to the south
toward McClelland Creek which borders the property to the south.
An EEC field engineer was on site during drilling operations to evaluate the subsurface
conditions encountered and to direct the drilling activities. Field logs prepared by EEC site
personnel were based on visual and tactual observation of disturbed samples and auger
cuttings. The final boring logs included with this report may contain modifications to the
field logs based on results of laboratory testing and evaluation. Based on results of the field
borings and laboratory evaluation, subsurface conditions can be generalized as follows.
Surface materials on this site include sparse vegetation and gravel surfaced drive areas.
Where encountered, the gravel thickness ranged from approximately 4 to 6 inches. The
topsoil vegetation and gravel surfacing were underlain by brown lean clay with varying
amounts of sand. The cohesive soils were generally very stiff to stiff and were generally
moist to very moist. The higher moisture content clay soils showed low swell potential in
laboratory testing. The lean clay soils extended to depths on the order of 10 to 16 feet below
present ground surface. The cohesive soils extended to the bottom of boring B-10 at a depth
of approximately 15 feet. The clay soils were underlain by highly weathered to weathered
claystone/siltstone/sandstone bedrock. The bedrock formation generally became less
weathered with depth and, where encountered, extended to the bottom of the borings at
depths of approximately 20 to 30 feet below existing site grades.
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The stratification boundaries indicated on the boring logs represent the approximate
locations of changes in soil and bedrock types. In-situ, the transition of materials may be
gradual and indistinct.
GROUNDWATER CONDITIONS
Observations were made while drilling and after completion of the borings to detect the
presence and depth to hydrostatic groundwater. In addition, field slotted PVC piezometers
were installed at four (4) boring locations to allow for short term monitoring of groundwater
levels. At the time of our field exploration, groundwater was observed at depths on the order
of 16 feet below ground surface. Measurements in the field piezometers, approximately 2
weeks after the initial drilling, indicate groundwater levels ranging from approximately 14 to
18 feet below existing ground surface. Measured depths to groundwater are indicated in the
upper right hand corner of the boring logs.
Fluctuations in groundwater levels can occur over time depending on variations in
hydrologic conditions and other conditions not apparent at the time of this report.
Monitoring of groundwater levels in cased borings which are sealed from the influence of
surface water would be required to more accurately evaluate the depth and fluctuations in
groundwater levels on the site.
Zones of perched and/or trapped groundwater may occur at times in the subsurface soils
overlying bedrock, on top of the bedrock surface or within permeable fractures within the
bedrock. The location and amount of perched/trapped water is depended on several factors
including hydrologic conditions, type of site development, irrigation demands on or adjacent
to the site and fluctuations in water levels in McClelland Creek on the southern boundary of
the property, as well as seasonal weather conditions. Observations submitted with this report
represent groundwater conditions at the time of the field exploration and may not be
indicative of other times or other locations.
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ANALYSIS AND RECOMMENDATIONS
Swell/Consolidation Test Results
The swell/consolidation test is performed to evaluate swell or collapse potential of soils or
bedrock for determining foundation, floor slab and pavement design criteria. In this test,
relatively undisturbed samples obtained from the California barrel sampler or thin-walled
tubes are placed in a laboratory apparatus and inundated with water under a pre-established
load. The swell index is the resulting amount of swell or collapse after the inundation
period, expressed as a percent of the sample’s initial thickness. After the inundation period,
additional incremental loads are applied to evaluate the swell pressure and consolidation
response of the tested sample.
For this assessment, we conducted five (5) swell/consolidation tests at varying depths within
the south portion of the site. The swell index values for the soils samples revealed low swell
characteristics ranging from no swell to approximately 0.4% swell. A slightly higher swell
was measured in the underlying bedrock with a swell of 2.8%.
The Colorado Association of Geotechnical Engineers (CAGE) uses the following information in
Table I, to provide uniformity in terminology between geotechnical engineers to provide a
relative correlation of slab performance risk to measured swell. “The representative percent
swell values are not necessarily measured values; rather, they are a judgment of the swell of the
soil and/or bedrock profile likely to influence slab performance.” Geotechnical engineers use
this information to also evaluate the swell potential risks for foundation performance based on
the risk categories.
TABLE I: Recommended Representative Swell Potential Descriptions and Corresponding
Slab Performance Risk Categories
Slab Performance Risk Category Representative Percent Swell
(500 psf Surcharge)
Representative Percent Swell
(1000 psf Surcharge)
Low 0 to < 3 0 < 2
Moderate 3 to < 5 2 to < 4
High 5 to < 8 4 to < 6
Very High > 8 > 6
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Based on the laboratory test results, the in-situ soil samples analyzed for this project at current
moisture contents and dry densities were within the low range. The higher swells were
observed in the underlying bedrock.
Site Preparation
Specific site grading plans were not available prior to preparation of this subsurface exploration
report. However, site topography indicates that cut/fill operations will likely be required to
achieve final grades. For the purposes of this report, we have assumed cuts and fills of less
than three (3) feet. If there are any significant deviations from the assumptions of the fill depth
when the final site plan is developed, the conclusions and recommendations of this report
should be reviewed and confirmed/modified as necessary to reflect the final planned site
configuration.
All existing vegetation and/or topsoil should be removed from any fill, structure or pavement
area. In addition, all existing site structures, foundations, floor slabs, flatwork and any
associated fill/backfill soils should be removed from the improvement areas. The gravel
surfacing could remain in-place; however, should be blended with underlying subgrade soils
during the scarification and compaction of the site subgrade soils.
After stripping and completing all cuts and removal of all unacceptable materials from the
site, and prior to placement of any moisture-conditioned fill material or site improvements,
the exposed soils should be scarified to a minimum depth of 9-inches, adjusted in moisture
content to within ±2% of standard Proctor optimum moisture content and compacted to at
least 95% of the material's standard Proctor maximum dry density as determined in
accordance with ASTM Specification D698, the standard Proctor procedure. Scarification
and recompaction of the subgrade soils within the basement areas of the structures would not
be required.
Fill soils required for developing the building, pavement and site subgrades, after the initial
zone has been stabilized, should consist of approved, low-volume-change materials, which
are free from organic matter and debris. It is our opinion the on-site cohesive soils could be
used as general site fill, provided adequate moisture treatment and compaction procedures
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are followed. Care will be needed to maintain the recommended moisture contents in the
subgrade soils prior to construction of the overlying improvements.
Site fill materials should be placed in loose lifts not to exceed 9 inches thick, adjusted in
moisture content and compacted to at least 95% of the materials maximum dry density as
determined in accordance the standard Proctor procedure. The moisture content of the fill
soils should be adjusted to be within range of ±2% of optimum moisture content at the time
of compaction. Care should be exercised after preparation of the subgrades to avoid
disturbing the subgrade materials. Positive drainage should also be developed away from the
structures to avoid wetting of subgrade materials. Subgrade materials becoming wet
subsequent to construction of the site improvements can result in unacceptable performance.
Foundations
Based on materials observed at the boring locations, we anticipate the site structures could be
supported on conventional footing foundations bearing on stiff sandy lean clay subgrade soils.
Some zones of soft or loose materials may be encountered which require removal and
replacement or stabilization in-place prior to construction of the footing foundations. In-place
stabilization would likely include mechanical stabilization of the soft subgrade areas. As an
alternative, drilled pier foundations could be used for support of the structures. The drilled pier
foundations would extend to bear an underlying claystone/siltstone/sandstone bedrock.
Recommendations are provided below for conventional footing foundations and drilled pier
foundations.
Footing Foundations
We anticipate the natural stiff sandy lean clay soils could be used for support of conventional
footing foundation system. For design of footing foundations bearing on suitable strength
natural sandy lean clay soils, we recommend using a net allowable total load soil bearing
pressure not to exceed 1,500 psf. The net allowable total load soils bearing pressure refers to
the pressure at foundation bearing level in excess of the minimum surrounding overburden
pressure.
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Occasional zones of higher moisture content, softer soils were observed in the subgrades.
Footing foundations should not be placed on or immediately above those zones. Mechanical
stabilization might be acceptable for development of stable subgrades for construction of the
footing foundations. Removal and replacement of unacceptable materials could also be
considered. The specific approach to developing the foundation bearing in these areas can best
be evaluated during construction based on the horizontal and vertical extent of the soft
materials and the consistency of those soils.
Exterior foundation and foundations in unheated areas should be located at least 30 inches
below adjacent exterior grade to provide frost protection. We recommend formed continuous
footing have a minimum width of 16 inches and isolated column foundations have a minimum
width of 30 inches.
Care should be taken at the time of construction to see that the foundations are supported on
suitable strength natural soils or acceptable modified subgrade materials.
Drilled Pier Foundations
As an alternative to the use of spread footings, consideration could be given to support the
proposed structures on a grade beam and straight shaft drilled caisson foundation extending
into the underlying bedrock formation. The bedrock was generally encountered at depths on
the order of 14 to 16 feet below existing site grades. For axial compression loads, the drilled
piers could be designed using a maximum end bearing pressures of 20,000 psf. Skin-friction of
2,000 psf could be used for that portion of the drilled pier extending into the underlying firm
harder bedrock formation. The drilled piers should be designed to maintain a minimum dead
load pressure of 5,000 psf.
Required pier penetration should be balanced against potential uplift forces due to expansion of
the bedrock on the site. For design purposes, the uplift force on each pier could be determined
on the basis of the following equation:
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Up =20 to 30 x D
Where: Up = the uplift force in kips, and
D = the pier diameter in feet
Uplift forces on piers should be resisted by a combination of dead-load and pier penetration
below a depth of 15-feet and into the bearing stratum. We recommend a minimum pier length
of 25 feet and minimum pier penetration of 10 feet into the bearing stratum.
To reduce potential uplift forces on piers, use of long grade beam spans to increase individual
pier loading, and small diameter piers should be considered. A minimum 4-inch void space
should be constructed beneath the grade beams between piers. The void material should be
suitable strength to support the weight of fresh concrete used in the grade beam construction
and to avoid collapse when foundation the backfill is placed.
Drilling caissons to design depth should be possible with conventional heavy-duty single flight
power augers equipped with rock teeth on the majority of the site. Areas of well-cemented
sandstone bedrock lenses may be encountered throughout the site at various depths where
specialized drilling equipment and/or rock excavating equipment may be required.
Excavations penetrating the well-cemented sandstone may require the use of specialized
heavy-duty equipment along with rock augers or core barrels.
The drilled shafts will probably remain open without stabilizing measures; however,
groundwater was encountered at depths on the order of 14 to 17 feet at the time of our
drilling operations. Encountering groundwater should be expected during the drilled pier
installation. Temporary casing could be needed to seal off the drilled shafts from
groundwater seams. Allowing water depths to stabilize and using tremie procedures could
also be considered. Pier concrete should be placed as soon possible after completion of
drilling and cleaning to reduce potential for groundwater accumulation in the drilled shafts.
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At-Grade Floor Slab Design and Construction
The variability of the existing and newly placed fill soils in close proximity to the slab
subgrade elevation, could result in differential movement of slabs should these materials
become elevated in moisture content. As presented on the boring logs and the swell-
consolidation test results, the subsurface soils and bedrock profile on the site exhibited
generally low expansive potential. Positive drainage should be developed away from the
building footprint(s) to reduce the potential for surface water infiltration from impacting the
underlying slab subgrade material.
Floor slab and pavement subgrades would generally be prepared as outlined under “Site
Preparation” in this report. To limit the amount of possible floor slab differential movement,
the floors should be supported on similar subgrade materials. In some areas, an
overexcavation and replacement procedure may be considered. For this approach, we expect
areas beneath the floor slab, depending upon building location and subsurface profile would
be undercut to depths of approximately 2 feet beneath top-of-subgrade and backfill/replaced
with an approved engineered/controlled fill material. An underslab gravel layer or thin
leveling course could be used underneath the concrete floor slabs and concrete pavement
areas to provide a leveling course for the concrete placement. Greater or lesser
overexcavation depths may be appropriate depending upon the final project development
layout and subgrade conditions.
Basement Design and Construction
Groundwater was encountered across the site within the preliminary soil borings at
approximate depths of 14 to 17 feet below existing site grades. Additional monitoring of
groundwater depths is being completed. If lower level construction is being considered for
the site, we would suggest that the lower level subgrade(s) be placed a minimum of 4-feet
above maximum anticipated rise in groundwater levels, or a combination exterior and
interior perimeter drainage system(s) be installed.
To reduce the potential for groundwater to enter the lower level/basement area of the
structure(s), installation of a dewatering system is recommended. The dewatering system
should, at a minimum, include an underslab gravel drainage layer sloped to an interior
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perimeter drainage system. The following provide preliminary design recommendations for
interior and exterior perimeter drainage systems.
The interior 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. The trench should be
inset from the interior edge of the nearest foundation a minimum of 12 inches. In addition,
the trench should be located such that an imaginary line extending downward at a 45-degree
angle from the foundation does not intersect the nearest edge of the trench. Gravel should
extend a minimum of 3 inches beneath the bottom of the pipe. The drainage system should
be sloped at a minimum 1/8 inch per foot to a suitable outlet, such as a sump and pump
system or a gravity drainage system.
The underslab drainage layer should consist of a minimum 6-inch thickness of free-draining
gravel meeting the specifications of ASTM C33, Size No. 57 or 67 or equivalent. Cross-
connecting drainage pipes should be provided beneath the slab at minimum 15-foot intervals,
and should discharge to the perimeter drainage system.
To reduce the potential for surface water infiltration from impacting foundation bearing soils
and/or entering any planned below grade portion of any residential structure, installation of
an exterior perimeter drainage system is recommended. This drainage system should be
constructed around the exterior perimeter of the lower level/below grade foundation system,
and sloped at a minimum 1/8 inch per foot to a suitable outlet, such as a sump and pump
system.
The exterior 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 at least 2 feet above the bottom of
the foundation wall. The system should be underlain with a polyethylene moisture barrier,
sealed to the foundation walls, and extending at least to the edge of the backfill zone. The
gravel should be covered with drainage fabric prior to placement of foundation backfill.
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Lateral Earth Pressures
Coefficient values for backfill with anticipated types of soils for calculation of active, at rest
and passive earth pressures are provided in the table below. Equivalent fluid pressure is
equal to the coefficient times the appropriate soil unit weight. As appropriate, buoyant
weights and hydrostatic pressures should be considered. Those coefficient values are based
on horizontal backfill with backfill soils consisting of essentially granular materials (import)
with friction angle 35 degrees or low volume change cohesive soils (site soils) assuming a
friction angle of at least 28 degrees. The assumed values should be verified with the material
supplier or through laboratory testing.
For the at-rest and active earth pressures, slopes away from the structure would result in
reduced driving forces with slopes up away from the structures resulting in greater forces on
the walls. The passive resistance would be reduced with slopes away from the wall. The top
30-inches of soil on the passive resistance side of walls could be used as a surcharge load;
however, should not be used as a part of the passive resistance value. Frictional resistance is
equal to the tangent of the friction angle times the normal force.
Soil Type On-Site Low Plasticity Cohesive Imported Medium Dense
Granular
Wet Unit Weight 120 135
Saturated Unit Weight 130 140
Friction Angle () – (assumed) 28° 35°
Active Pressure Coefficient 0.36 0.27
At-rest Pressure Coefficient 0.53 0.43
Passive Pressure Coefficient 2.77 3.70
Surcharge loads or point loads placed in the backfill can also create additional loads on
below grade walls. Those lateral pressures should be evaluated on an individual basis.
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The outlined lateral earth values do not include factors of safety nor allowances for
hydrostatic loads. Care should be taken to develop appropriate drainage systems behind
below grade walls to eliminate potential for hydrostatic loads developing on the walls.
Those systems would likely include perimeter drain systems extending to sump areas or free
outfall where reverse flow cannot occur into the system. Where necessary, appropriate
hydrostatic load values should be used for design.
Use of active lateral pressure conditions assumes movement (rotation) of the wall. That
behavior is consistent with retaining walls or similar structures. At-rest pressures should be
used for design of walls restricted from movement such as basement walls.
Pavement Design and Construction
We expect the site pavements will carry low volumes of light vehicles such as automobiles
and light trucks. A portion of the pavement may also be used by heavier trucks (trash
trucks). For design, heavy-duty truck pavement areas are assumed to carry equivalent daily
load axle (EDLA) rating of 25 and automobile areas assumed to carry an EDLA of 5.
Proofrolling and recompacting the subgrade is recommended immediately prior to placement
of the aggregate road base section. Soft or weak areas delineated by the proofrolling
operations should be undercut or stabilized in-place to achieve the appropriate subgrade
support. Based on the subsurface conditions encountered at the site, it is recommended
preliminary design of on-site drive and parking areas be completed using an R-value of 5.
With the slight expansive characteristics of the overburden soils, a swell mitigation plan may
be necessary to reduce the potential for movement within the pavement section if soils are
allowed to dry excessively and be densified by construction traffic prior to pavement
construction. Over-excavating on the order of two (2) feet of the overburden soils and
replacement of these soils as moisture conditioned/engineered fill material may be considered
beneath pavement areas. If pumping conditions are observed at elevated subgrade moisture
contents either at current moisture content or with a moisture conditioned subgrade; subgrade
stabilization by incorporating at least 13 percent by weight, Class C fly ash, into the upper 12-
inches of subgrade could also be needed.
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Hot Mix Asphalt (HMA) underlain by crushed aggregate base course, with or without a fly ash
treated subgrade, and non-reinforced concrete pavement underlain by an approved subgrade
zone appear to be feasible alternatives for the proposed on-site paved sections. Eliminating the
risk of movement within the proposed pavement section may not be feasible due to the
characteristics of the subsurface materials; but it may be possible to further reduce the risk of
movement if significantly more expensive subgrade stabilization measures are used during
construction. We would be pleased to discuss other construction alternatives with you upon
request.
Pavement design methods are intended to provide structural sections with adequate thickness
over a particular subgrade such that wheel loads are reduced to a level the subgrade can
support. The support characteristics of the subgrade for pavement design do not account for
shrink/swell movements of an expansive clay subgrade or consolidation of a wetted
subgrade. Thus, the pavement may be adequate from a structural standpoint, yet still
experience cracking and deformation due to shrink/swell related movement of the subgrade.
It is, therefore, important to minimize moisture changes in the subgrade to reduce
shrink/swell movements.
Suggested preliminary pavement sections are provided below in Table III. HBP pavements
may show rutting and distress in truck loading and turning areas. Concrete pavements
should be considered in those areas.
TABLE III – PRELIMINARY SUGGESTED PAVEMENT SECTIONS
Automobile Parking Heavy Duty Areas and Taxiways
EDLA
Reliability
Resilient Modulus (R=5)
PSI Loss
5
75%
3025
2.2
25
85%
3025
2.5
Design Structure Number 2.50 3.44
Composite
Hot Bituminous Pavement
Aggregate Base
(Design Structure Number)
Composite with Stabilized Subgrade
Hot Bituminous Pavement
Aggregate Base
Fly Ash Treated Subgrade
(Design Structure Number)
4"
7"
(2.53)
3-1/2"
6"
12″
(2.80)
5½"
9"
(3.41)
4½"
8"
12″
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Site grading is generally accomplished early in the construction phase. However as
construction proceeds, the subgrade may be disturbed due to utility excavations, construction
traffic, desiccation, or rainfall. As a result, the pavement subgrade may not be suitable for
pavement construction and corrective action will be required. The subgrade should be
carefully evaluated at the time of pavement construction for signs of disturbance, such as but
not limited to drying, or excessive rutting. If disturbance has occurred, pavement subgrade
areas should be reworked, moisture conditioned, and properly compacted to the
recommendations in this report immediately prior to paving.
Final pavement design report, in general accordance with City of Fort Collins pavement design
criteria will be required prior to pavement construction on County Fair Lane. That
exploration/design is completed after the site utilities/infrastructure are installed and the
subgrades are prepared/constructed to “rough” final subgrade elevations. A preliminary
section estimate based on the roadway classification can be obtained in the LCUASS
Standards.
Other Considerations
Positive drainage should be developed away from the structures and pavement areas with a
minimum slope of 1-inch per foot for the first 10-feet away from the improvements in
landscape areas. Care should be taken in planning of landscaping adjacent to the building
and parking and drive areas to avoid features which would pond water adjacent to the
pavement, foundations or stemwalls. Placement of plants which require irrigation systems or
could result in fluctuations of the moisture content of the subgrade material should be
avoided adjacent to site improvements. Lawn watering systems should not be placed within
5 feet of the perimeter of the building and parking areas. Spray heads should be designed not
to spray water on or immediately adjacent to the structure or site pavements. Roof drains
should be designed to discharge at least 5 feet away from the structure and away from the
pavement areas.
Influx of groundwater should be anticipated for excavations approaching the level of
bedrock. Pumping from sumps may be needed to control water within the excavations.
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July 10, 2012
Page 16
Excavations into the on-site soils may encounter caving soils and possibly groundwater,
depending upon the final depth of excavation. 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.
Sulfate Considerations
The water soluble sulfate (SO4) testing of the on-site overburden subsoils indicated sulfate
contents generally less than 1 pps or contents less than 150 ppm, sulfate (SO4) in water, or less
than 0.1% water soluble sulfate (SO4) in soils, percent by weight, are considered negligible risk
of sulfate attack on Portland cement concrete. Less than 150 ppm results would typically
indicate that ASTM Type I Portland cement is suitable for all concrete on and below grade.
Therefore, based on the results as presented herein it appears Type I or Type I/II Portland
cement could be used for site cast-in-place concrete. Foundation concrete should be designed
in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4.
GENERAL COMMENTS
The analysis and recommendations presented in this report are based upon the data obtained
from the soil borings performed at the indicated locations and from any other information
discussed in this report. This report does not reflect any 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 evident, it will be necessary to re-evaluate the
recommendations of this report.
It is recommended that the geotechnical engineer be retained to review the plans and
specifications so comments can be made regarding the interpretation and implementation of
our geotechnical recommendations in the design and specifications. It is further
recommended that the geotechnical engineer be retained for testing and observations during
Earth Engineering Consultants, Inc.
EEC Project No. 1122052
July 10, 2012
Page 17
earthwork and foundation construction phases to help determine that the design requirements
are fulfilled.
This report has been prepared for the exclusive use of Architecture West, LLC, for specific
application to the project discussed and has been prepared in accordance with generally
accepted geotechnical engineering practices. No warranty, express or implied, is made. In
the event that any 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 the changes are reviewed and the conclusions of this report are
modified or verified in writing by the geotechnical engineer. Additional
exploration/evaluation will be necessary to provide specific recommendations for individual
users/buildings in part, to match owner expectations with geotechnical recommendations.
DRILLING AND EXPLORATION
DRILLING & SAMPLING SYMBOLS:
SS: Split Spoon - 13/8" I.D., 2" O.D., unless otherwise noted PS: Piston Sample
ST: Thin-Walled Tube - 2" O.D., unless otherwise noted WS: Wash Sample
R: Ring Barrel Sampler - 2.42" I.D., 3" O.D. unless otherwise noted
PA: Power Auger FT: Fish Tail Bit
HA: Hand Auger RB: Rock Bit
DB: Diamond Bit = 4", N, B BS: Bulk Sample
AS: Auger Sample PM: Pressure Meter
HS: Hollow Stem Auger WB: Wash Bore
Standard "N" Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2-inch O.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 ground water. In low permeability soils, the accurate determination of ground water levels is not
possible with only short term observations.
DESCRIPTIVE SOIL CLASSIFICATION
Soil Classification is based on the Unified Soil Classification
system and the ASTM Designations D-2488. Coarse Grained
Soils have move than 50% of their dry weight retained on a #200
sieve; they are described as: boulders, cobbles, gravel or sand.
Fine Grained Soils 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
soils are defined on the basis of their relative in-place density
and fine grained soils on the basis of their consistency.
Example: Lean clay with sand, trace gravel, stiff (CL); silty
sand, trace gravel, medium dense (SM).
CONSISTENCY OF FINE-GRAINED SOILS
Unconfined Compressive
Strength, Qu, psf Consistency
< 500 Very Soft
500 - 1,000 Soft
1,001 - 2,000 Medium
2,001 - 4,000 Stiff
4,001 - 8,000 Very Stiff
8,001 - 16,000 Very Hard
RELATIVE DENSITY OF COARSE-GRAINED SOILS:
N-Blows/ft Relative Density
0-3 Very Loose
4-9 Loose
10-29 Medium Dense
30-49 Dense
50-80 Very Dense
80 + Extremely Dense
PHYSICAL PROPERTIES OF BEDROCK
DEGREE OF WEATHERING:
Slight Slight decomposition of parent material on
joints. May be color change.
Moderate Some decomposition and color change
throughout.
High Rock highly decomposed, may be extremely
broken.
HARDNESS AND DEGREE OF CEMENTATION:
HARVEST MIXED USE
FORT COLLINS, COLORADO
EEC PROJECT NO. 1122052
JUNE 2012
HARVEST MIXED USE
FORT COLLINS, COLORADO
EEC PROJECT NO. 1122052
JUNE 2012
DATE:
RIG TYPE: CME45
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: MANUAL
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
SANDY LEAN CLAY (CL) 1
brown _ _
very stiff 2
_ _
3
_ _
4
_ _
CS 5 5 6000 19.5 99.4 800 psf 0.3%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
grey / brown SS 10 13 5500 19.3
with calcareous deposits _ _
11
_ _
12
_ _
13
_ _
14
LEAN CLAY (CL) _ _
brown / grey / rust CS 15 30 4500 12.6 121.1
very stiff _ _
with gravelly seams 16
_ _
CLAYSTONE / SILTSTONE / SANDSTONE 17
brown / grey / rust _ _
highly weathered 18
_ _
19
_ _
SS 20 22 8500 24.8
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 50/8" 9000+ 17.5 113.5
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants
5305 ZIEGLER ROAD
DATE:
RIG TYPE: CME45
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: MANUAL
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
CLAYSTONE / SILTSTONE / SANDSTONE 27
brown / grey / rust _ _
highly weathered 28
_ _
29
_ _
SS 30 50/11" 9000+ 16.2
_ _
BOTTOM OF BORING DEPTH 30.5' 31
_ _
32
_ _
33
_ _
34
_ _
35
_ _
36
_ _
37
_ _
38
_ _
39
_ _
40
_ _
41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants
5305 ZIEGLER ROAD
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME45
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: MANUAL
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
GRAVEL - 4" _ _
1
SANDY LEAN CLAY (CL) _ _
brown / rust 2
stiff to very stiff _ _
CS 3 13 9000+ 14.8 111.4
_ _
4
_ _
SS 5 9 7000 20.0
_ _
6
_ _
7
_ _
8
_ _
9
_ _
*intermittent LEAN CLAY lens CS 10 16 6000 17.6 112.6 34 19 86.3 1000 psf 0.4%
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 9 2000 20.9
_ _
16
_ _
CLAYSTONE / SILTSTONE / SANDSTONE 17
highly weathered _ _
18
_ _
19
_ _
CS 20 50/11" 9000 21.9 107.8
BOTTOM OF BORING DEPTH 20.0' _ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants
5305 ZIEGLER ROAD
DATE:
RIG TYPE: CME45
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: MANUAL
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
GRAVEL - 5" _ _
1
SANDY LEAN CLAY (CL) _ _
dark brown / brown / tan 2
stiff to very stiff _ _ % @ 150 psf
CS 3 14 8000 22.3 104.5 250 psf 0.4%
_ _
4
_ _
SS 5 14 9000+ 17.0
_ _
6
_ _
7
_ _
8
_ _
9
grey / brown / rust _ _
CS 10 10 5000 27.5 97.8
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 11 2000 27.4
CLAYSTONE _ _
brown / grey / rust 16
highly weathered _ _
17
_ _
18
_ _
19
_ _
CS 20 50/9" 9000+ 19.4 111.2
BOTTOM OF BORING DEPTH 20.0' _ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants
5305 ZIEGLER ROAD
DATE:
RIG TYPE: CME45
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: MANUAL
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
GRAVEL - 4" _ _
1
SANDY LEAN CLAY (CL) _ _
dark brown / brown 2
very stiff _ _
with traces of gravel 3
_ _
4
_ _
CS 5 8 5000 15.7 110.1 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
brown / rust _ _
CS 10 17 7000 24.1 103.3
_ _
11
_ _
12
brown / grey / rust _ _
13
_ _
14
_ _
SS 15 14 4000 22.3
_ _
16
_ _
CLAYSTONE 17
brown / grey / rust _ _
highly weathered 18
_ _
19
_ _
CS 20 32 9000+ 19.3 111.0
BOTTOM OF BORING DEPTH 20.0' _ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants
5305 ZIEGLER ROAD
DATE:
RIG TYPE: CME45
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: MANUAL
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
FILL: SANDY LEAN CLAY (CL) 1
brown, with gravel _ _
2
_ _
SANDY LEAN CLAY (CL) CS 3 12 8000 13.2 107.8
brown / tan _ _
very stiff 4
_ _
SS 5 11 8000 11.0
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 18 9000+ 15.6 113.6 3000 psf 2.8%
CLAYSTONE _ _
brown / grey / rust 11
highly weathered _ _
12
_ _
13
_ _
14
_ _
SS 15 26 9000+ 19.1
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 50/10" 9000+ 18.0 112.3
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 50 9000+ 16.5
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants
5305 ZIEGLER ROAD
DATE:
RIG TYPE: CME45
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: MANUAL
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
CLAYSTONE 27
brown / grey / rust _ _
highly weathered 28
_ _
29
_ _
CS 30 50/7" 9000+ 17.9 113.5
BOTTOM OF BORING DEPTH 30.0' _ _
31
_ _
32
_ _
33
_ _
34
_ _
35
_ _
36
_ _
37
_ _
38
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39
_ _
40
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41
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42
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43
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44
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45
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46
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47
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48
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49
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50
_ _
Earth Engineering Consultants
5305 ZIEGLER ROAD
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME45
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: MANUAL
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
GRAVEL - 4" _ _
1
FILL: SANDY LEAN CLAY (CL) _ _
brown 2
stiff to very stiff _ _
with traces of gravel 3
_ _
4
_ _
CS 5 8 9000+ 11.4 119.6
_ _
SANDY LEAN CLAY (CL) 6
brown / rust _ _
stiff to very stiff 7
_ _
8
_ _
9
_ _
SS 10 20 9000 21.2
_ _
11
_ _
12
_ _
13
_ _
14
brown / grey / rust _ _
CS 15 16 7000 23.0 101.4
BOTTOM OF BORING DEPTH 15.0' _ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants
5305 ZIEGLER ROAD
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
Sample Location: Boring 5, Sample 1, Depth 4'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
Beginning Moisture: 19.5% Dry Density: 105.6 pcf Ending Moisture: 18.2%
Swell Pressure: 800 psf % Swell @ 500: 0.3%
5305 Ziegler Road
Fort Collins, Colorado
1122052
June 2012
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Rust Sandy Lean Clay (CL)
Sample Location: Boring 6, Sample 3, Depth 9'
Liquid Limit: 34 Plasticity Index: 19 % Passing #200: 86.3%
Beginning Moisture: 17.6% Dry Density: 112.8 pcf Ending Moisture: 17.7%
Swell Pressure: 1000 psf % Swell @ 500: 0.4%
5305 Ziegler Road
Fort Collins, Colorado
1122052
June 2012
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Dark Brown / Brown / Tan Sandy Lean Clay (CL)
Sample Location: Boring 7, Sample 1, Depth 2'
Liquid Limit: Plasticity Index: % Passing #200:
Beginning Moisture: 22.3% Dry Density: 98.4 pcf Ending Moisture: 23.2%
Swell Pressure: 250 psf % Swell @ 150: 0.4%
5305 Ziegler Road
Fort Collins, Colorado
1122052
June 2012
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Dark Brown / Brown Sandy Lean Clay (CL)
Sample Location: Boring 8, Sample 1, Depth 4'
Liquid Limit: Plasticity Index: % Passing #200:
Beginning Moisture: 15.7% Dry Density: 112.5 pcf Ending Moisture: 19.9%
Swell Pressure: <500 psf % Swell @ 500: None
5305 Ziegler Road
Fort Collins, Colorado
1122052
June 2012
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Grey / Rust Claystone (LEAN to FAT CLAY with SAND)
Sample Location: Boring 8, Sample 4, Depth 19'
Liquid Limit: 52 Plasticity Index: 33 % Passing #200: 80.6%
Beginning Moisture: 19.4% Dry Density: 106.2 pcf Ending Moisture: 23.0%
Swell Pressure: 2500 psf % Swell @ 500: 0.7%
5305 Ziegler Road
Fort Collins, Colorado
1122052
June 2012
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
5305 Ziegler Road
Fort Collins, Colorado
1122052
June 2012
Beginning Moisture: 15.6% Dry Density: 110.4 pcf Ending Moisture: 20.9%
Swell Pressure: 3000 psf % Swell @ 500: 2.8%
Sample Location: Boring 9, Sample 3, Depth 9'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Tan Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
2 1/2" (63 mm)
2" (50 mm)
1 1/2" (37.5 mm)
1" (25 mm)
3/4" (19 mm)
1/2" (12.5 mm)
3/8" (9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 16 (1.18 mm)
No. 30 (600 m)
No. 40 (425 m)
No. 50 (300 m)
No. 100 (150 m)
No. 200 (75 m)
Project: 5305 Ziegler Road
Location: Fort Collins, Colorado
Project No: 1122052
Sample Desc.: B-5, S-3 at 14'
Date: June 2012
100
100
100
98
92
82
41
25.7
71
56
EARTH ENGINEERING CONSULTANTS, INC.
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
SUMMARY OF LABORATORY TEST RESULTS
100
64
100
100
Sieve Size Percent Passing
100
Project: 5305 Ziegler Road
Project Number:
Sample Desc.: B-5, S-3 at 14'
Date: June 2012
Summary of Washed Sieve Analysis Tests (ASTM C117 & C136)
Coarse Fine
EARTH ENGINEERING CONSULTANTS, INC.
1122052
Coarse Medium
Cobble
Fine
Sand Silt or Clay
Gravel
Location: Fort Collins, Colorado
0
10
20
30
40
50
60
70
80
90
100
1000 100 10 1 0.1 0.01
Finer by Weight (%)
Grain Size (mm)
5" 3" 1" 1/2" No. 4 No. 16 No. 40 No. 100
6" 4" 2" 3/4" 3/8" No. 8 No. 30 No. 50 No. 200
FORT COLLINS, COLORADO
PROJECT NO: 1122052 JUNE 2012
LOG OF BORING B-10
SHEET 1 OF 1 WATER DEPTH
START DATE 6/19/2012 WHILE DRILLING None
FINISH DATE 6/19/2012 7/5/2012 14.5'
SURFACE ELEV N/A 24 HOUR 15.0'
A-LIMITS SWELL
PROJECT NO: 1122052 JUNE 2012
LOG OF BORING B-9 (PIEZOMETER)
SHEET 2 OF 2 WATER DEPTH
START DATE 6/19/2012 WHILE DRILLING None
FINISH DATE 6/19/2012 7/5/2012 14.3'
SURFACE ELEV N/A 24 HOUR 17.1'
A-LIMITS SWELL
FORT COLLINS, COLORADO
PROJECT NO: 1122052 JUNE 2012
LOG OF BORING B-9 (PIEZOMETER)
SHEET 1 OF 1 WATER DEPTH
START DATE 6/19/2012 WHILE DRILLING None
FINISH DATE 6/19/2012 7/5/2012 14.3'
SURFACE ELEV N/A 24 HOUR 17.1'
A-LIMITS SWELL
FORT COLLINS, COLORADO
PROJECT NO: 1122052 JUNE 2012
LOG OF BORING B-8
SHEET 1 OF 1 WATER DEPTH
START DATE 6/19/2012 WHILE DRILLING None
FINISH DATE 6/19/2012 AFTER DRILLING N/A
SURFACE ELEV N/A 24 HOUR N/A
A-LIMITS SWELL
FORT COLLINS, COLORADO
PROJECT NO: 1122052 JUNE 2012
LOG OF BORING B-7
SHEET 1 OF 1 WATER DEPTH
START DATE 6/19/2012 WHILE DRILLING 13.0'
FINISH DATE 6/19/2012 AFTER DRILLING 14.0'
SURFACE ELEV N/A 24 HOUR N/A
A-LIMITS SWELL
FORT COLLINS, COLORADO
PROJECT NO: 1122052 JUNE 2012
LOG OF BORING B-6
SHEET 1 OF 1 WATER DEPTH
START DATE 6/19/2012 WHILE DRILLING 15.0'
FINISH DATE 6/19/2012 AFTER DRILLING N/A
SURFACE ELEV N/A 24 HOUR N/A
A-LIMITS SWELL
PROJECT NO: 1122052 JUNE 2012
LOG OF BORING B-5
SHEET 2 OF 2 WATER DEPTH
START DATE 6/19/2012 WHILE DRILLING None
FINISH DATE 6/19/2012 7/5/2012 16
SURFACE ELEV N/A 24 HOUR 16.0'
A-LIMITS SWELL
FORT COLLINS, COLORADO
PROJECT NO: 1122052 JUNE 2012
LOG OF BORING B-5
SHEET 1 OF 1 WATER DEPTH
START DATE 6/19/2012 WHILE DRILLING None
FINISH DATE 6/19/2012 7/5/2012 16
SURFACE ELEV N/A 24 HOUR 16.0'
A-LIMITS SWELL
Limestone and Dolomite:
Hard Difficult to scratch with knife.
Moderately Can be scratched easily with knife.
Hard Cannot be scratched with fingernail.
Soft Can be scratched with fingernail.
Shale, Siltstone and Claystone:
Hard Can be scratched easily with knife, cannot be
scratched with fingernail.
Moderately Can be scratched with fingernail.
Hard
Soft Can be easily dented but not molded with
fingers.
Sandstone and Conglomerate:
Well Capable of scratching a knife blade.
Cemented
Cemented Can be scratched with knife.
Poorly Can be broken apart easily with fingers.
Cemented
(3.46)
PCC (Non-reinforced) – placed on an
approved subgrade layer 5″ 7″