HomeMy WebLinkAboutFOX GROVE PHASE 2 - PDP190002 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTPRELIMINARY GEOTECHNICAL EXPLORATION REPORT
LEE MLD – LOT 2
FORT COLLINS, COLORADO
EEC PROJECT NO. 1132018
Prepared for:
Imago Enterprises, Inc.
140 Palmer Drive
Fort Collins, Colorado 80580
Attn: Mr. Les Kaplan (lesterkaplan@comcast.net)
Prepared by:
Earth Engineering Consultants, LLC
4396 Greenfield Drive
Windsor, Colorado 80550
PRELIMINARY GEOTECHNICAL EXPLORATION REPORT
LEE MLD – LOT 2
FORT COLLINS, COLORADO
EEC PROJECT NO. 1132018
April 18, 2013
INTRODUCTION
The preliminary geotechnical exploration requested for the Lee MLD – Lot 2 residential
development project planned for construction south of East Mulberry Street and east of
Interstate 25 in Fort Collins, Colorado has been completed. The approximate area included
in the preliminary exploration completed at this time is indicated on the attached boring
location diagram.
A total of five (5) soil borings were advanced to depths of approximately 20 feet below
present site grades within the planned development area to obtain information on existing
subsurface conditions. The approximate locations of those borings are indicated on the
attached boring location diagram. The area evaluated as a part of the preliminary exploration
will be developed as single and multi-family residential. A total of 83 single family
residential lots, 22 duplex units, and 54 multifamily units are currently planned for the
approximate 36 acre site. Foundation and floor loads for proposed site structures are
expected to be light. The multifamily buildings are not expected to have basements since the
current site plan indicates these buildings, which are proposed for the west side of the
development, are located within a “floodplain”. The duplex and single family structures will
likely have full basements. City of Fort Collins streets will be constructed for access in this
area. We expect small cuts and fills will be required to develop site grades for this
development.
The purpose of this report is to describe the subsurface conditions encountered in the test
borings, analyze and evaluate the test data and provide preliminary geotechnical
considerations for the proposed site development.
EXPLORATION AND TESTING PROCEDURES
The test boring locations were selected by Earth Engineering Consultants, LLC (EEC)
personnel and located in the field by pacing and estimating angles from identifiable site
Earth Engineering Consultants, LLC
EEC Project No. 1132018
April 18, 2013
Page 2
features. The approximate boring locations are indicated on the attached boring location
diagram. The locations of the test borings should be considered accurate only to the degree
implied by the methods used to make the field measurements.
The 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 and hardness of weathered
bedrock. 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.
At each of the boring locations, a field slotted PVC pipe was placed in the open boreholes
prior to backfilling to allow for temporary monitoring of groundwater levels. Water levels
were measured on two (2) occasions after drilling. The temporary piezometers were
removed after the final measurements.
Laboratory moisture content tests were completed on each of the recovered samples. The
unconfined compressive strength of appropriate samples was estimated using a calibrated
hand penetrometer. Wash sieve analysis and Atterberg limits tests were completed on
selected samples to determine the quantity and plasticity of the fines in the subgrade.
Swell/consolidation tests were also completed on selected samples to evaluate the tendency
for subgrade materials to change volume with variation in moisture content and load.
Soluble sulfate tests were completed on selected samples to assess the potential for sulfate
attack on site cast concrete. Results of the outlined tests are indicated on the attached boring
logs and summary sheets.
Earth Engineering Consultants, LLC
EEC Project No. 1132018
April 18, 2013
Page 3
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 material’s texture and plasticity. The estimated group
symbol for Unified Soil Classification System is indicated on the boring logs and a brief
description of that classification system is included with this report.
SITE AND SUBSURFACE CONDITIONS
The Lee MLD – Lot 2 development will be located approximately ½ mile south of East
Mulberry Street and ½ mile east of Interstate 25 in Fort Collins. The approximate site layout
is indicated on the attached boring location diagram. Surface drainage at the site is generally
to the south with maximum grade difference across the site on the order of 5 feet. The south
side of the site drains into a drainage ditch. This drainage ditch and the west side of the site
drain into Boxelder Creek, which runs along the northwest and west boundary of the
development. The site is currently an agricultural field.
Based on results of the field borings and laboratory testing, subsurface conditions can be
generalized as follows. Variable, generally sparse vegetation was encountered at the surface
at the boring locations. The vegetation and any associated topsoil were underlain by clayey
fine-grained sands. Sand and gravel with intermittent seams of sandy silt and sandy clay was
encountered with depth. The borings were terminated at depths of approximately 20 feet
below the existing grade in the granular soils.
The near surface clayey fine-grained sands were dry in a portion of the borings and,
consequently, indicated moderate swell potential. These near surface soils varied from loose
to medium dense and extended to a depth of approximately 9 feet. Between the depths of
approximately 9 to 18 feet, the sand and gravel was generally dense to medium dense. Loose
silty sands and clayey sands were generally encountered between 18 and 20 feet, which is
below the observed groundwater level.
The stratification boundaries indicated on the boring logs represent the approximate
locations of changes in soil types; in-situ, the transition of materials may be gradual and
Earth Engineering Consultants, LLC
EEC Project No. 1132018
April 18, 2013
Page 4
indistinct. The test borings indicate the subsurface conditions at the boring locations.
Subsurface conditions can vary at short distances from the boring locations and across the
site.
GROUNDWATER OBSERVATIONS
Observations were made while drilling and after completion of the borings to detect the
presence and depth to hydrostatic groundwater. In addition, the depth to groundwater was
measured in the temporary piezometers at approximately two and ten days after drilling. The
measured depth to groundwater at the piezometer locations is indicated in the upper right
hand corner of the attached boring logs. Groundwater depths were approximately 11 to 12
feet at the time of drilling and when measured again on April 10 and April 18, 2013.
Zones of perched and/or trapped water can be encountered in more permeable zones
interbedded with the cohesive soils and/or bedrock at times throughout the year. Perched
water is commonly encountered in soils immediately overlying less permeable bedrock. The
location and amount of perched/trapped water can vary over time depending on variations in
hydrologic conditions and other conditions not apparent at the time of this report. At the
time of our exploration, the drainage ditch located along the south property boundary was
not flowing.
Fluctuations in groundwater levels can also occur with variations in hydrologic conditions
and other conditions not apparent at the time of this report. Groundwater measurements
provided with this report are indicative of groundwater levels at the locations and at the time
the borings/groundwater measurements were completed.
ANALYSIS AND RECOMMENDATIONS
Swell/Consolidation Test Results
Swell/consolidation testing is performed to evaluate the swell or collapse potential of soil or
bedrock to help determine foundation, floor slab and/or pavement design criteria. In the
swell/consolidation test, relatively undisturbed samples obtained directly from the California
barrel sampler are placed in a laboratory apparatus and inundated with water under a pre-
Earth Engineering Consultants, LLC
EEC Project No. 1132018
April 18, 2013
Page 5
established load. The swell-index is the resulting amount of swell or collapse under the initial
loading condition expressed as a percent of the sample’s initial thickness. After the inundation
period, additional incremental loads are applied to evaluate swell pressure and/or consolidation.
As a part of this preliminary assessment, we conducted three (3) swell/consolidation tests on
samples obtained from the site. The swell index values for the samples analyzed revealed low
to moderate swell potential ranging from approximately 0% to (+) 9.3% at a dead load of 150
or 500 psf. A portion of the tested samples indicated a tendency to consolidate under load.
The Colorado Association of Geotechnical Engineers (CAGE) uses the following information
to provide uniformity in terminology between geotechnical engineers to provide a relative
correlation risk performance 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.
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
Based on the laboratory test results, the samples of clayey fine-grained sand analyzed for the
development were within the low range to moderate range.
General Soil Evaluations
The near surface clayey fine-grained sand soils encountered above a depth of approximately
9 feet, were generally medium dense to loose and varied from moist to dry with low to
moderate swell potential. Mitigation of a thin zone of the dry, higher swelling clayey fine-
grained sand materials will likely be required to reduce potential for swelling subgrade soils
Earth Engineering Consultants, LLC
EEC Project No. 1132018
April 18, 2013
Page 6
causing heaving of overlying improvements. City of Fort Collins standards require
mitigation in roadway areas for soils which show swells in excess of 2 percent.
Softer/looser zones were encountered in the clayey sands at depths of approximately 5 feet
below present site grades in all of the test borings. Mitigation of loose zones could be
needed for footing foundations supported within this zone. Mitigation of loose zones may
also be required for development of floor slabs or street subgrades depending on site cuts and
fills. The looser material may also lead to instability of site excavations extending into this
zone requiring stabilization of trench sides and bottoms for utility construction.
Site groundwater measurements indicate groundwater levels generally encountered 11 to 12
feet below present site grades. The depth to groundwater at the site may be influenced to a
large extent by the flow of water in the ditch along the south property boundary and in
Boxelder Creek along the west property boundary.
General Site Preparation
All existing vegetation and/or topsoil should be removed from building, fill or other
improvement areas. After stripping and completing all cuts and prior to placement of any fill
or structures, the in-place soils should be scarified to a minimum depth of 9 inches, adjusted
in moisture content and compacted to at least 95% of the material’s maximum dry density as
determined in accordance with ASTM Specification D698, the standard Proctor procedure.
The moisture content of the scarified soils should be adjusted to be within the range of ± 2%
of standard Proctor optimum moisture content at the time of compaction.
Overexcavations and moisture conditioning may be required in areas of dry/hard near
surface cohesive materials to mitigate higher swelling subgrades. Swelling cohesive soils
allowed to remain beneath roadways, sidewalks and floor slabs or similar improvements
could result in post-construction heaving of those improvements with wetting of the
subgrade materials.
Fill soils required to develop the site grades should consist of approved, low-volume-change
materials which are free from organic matter and debris. In general, the site soils could be
Earth Engineering Consultants, LLC
EEC Project No. 1132018
April 18, 2013
Page 7
used as overlot fill materials. Care should be taken during fill placement to avoid placing
layers or pockets of clean granular materials within the cohesive subgrades to reduce
potential for ponding of water at varying locations in the subgrades.
In general, site fill materials would be placed in loose lifts not to exceed 9 inches thick,
adjusted in moisture content and compacted to at least 95% of the material’s maximum dry
density as determined in accordance with the standard Proctor procedure. The moisture
content of predominately clay soils should be adjusted to be within the range of ± 2% of
optimum moisture content at the time of placement. Granular soils should be adjusted to a
workable moisture content.
Specific explorations should be completed for each building to develop recommendations
specific to the proposed structure and owner/builder and for specific parking, drive and street
areas. Specific exploration for City of Fort Collins streets will be required after pavement
subgrades are developed to approximate finish surface elevation and utilities have been
installed within the street right-of-ways.
Building Foundations
We anticipate use of conventional footing foundations could be considered for lightly loaded
structures at this site. We expect footing foundations would be supported either on the
native soils or on newly placed and compacted fills. Soft and/or loose zones were observed
in the near surface clayey fine-grained sand soils so that care will be necessary to see that
foundations are not supported directly on soft or loose materials. Mitigation for soft
subgrade soils should be expected over much of the site.
We anticipate footing foundations for site structures could be designed with net allowable
total load soil bearing pressures in the range of 1,500 psf.
Footings would be supported at least 30 inches below final adjacent exterior grade to provide
frost protection. Minimum footing widths are typically recommended in the range of 12 to 16
inches for continuous formed footings and 24 to 30 inches for isolated column foundations.
Earth Engineering Consultants, LLC
EEC Project No. 1132018
April 18, 2013
Page 8
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. The coefficient values are based on
horizontal backfill with backfill soils consisting of either essentially granular materials with
a friction angle of 30 degrees or greater or low volume change cohesive soils with a friction
angle of at least 25 degrees. Varying backfill materials and/or configurations would result in
greater or lesser coefficient values depending on the materials used and final configuration.
Soil Type On-Site Low Plasticity
Cohesive
Imported Medium Dense
Granular
Wet Unit Weight 120 135
Saturated Unit Weight 130 140
Friction Angle () – (assumed) 25° 35°
Active Pressure Coefficient 0.41 0.27
At-rest Pressure Coefficient 0.58 0.42
Passive Pressure Coefficient 2.46 3.70
Surcharge loads or point loads placed in the backfill can create additional loads on below
grade walls. Those lateral pressures should be evaluated on an individual basis.
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 the potential for hydrostatic loads developing on the walls.
Where necessary, appropriate hydrostatic load values should be used for design.
Preliminary Pavements Design
We anticipate site pavements will be supported on the near surface clayey fine-grained sand
soils. Those soils have low to moderate support capacity for site pavements. In addition, the
clayey subgrade soils at elevated moisture content can show instability and strength loss. In-
Earth Engineering Consultants, LLC
EEC Project No. 1132018
April 18, 2013
Page 9
place stabilization may be required for excessively wet, pumping soils prior to placement of
an overlying pavement section.
A minimum pavement section of 4 inches of hot bituminous pavement (HBP) overlying 6
inches of aggregate base course (ABC) is required by City of Fort Collins standards. That
section could be used as a preliminary estimate for local streets per Larimer County Urban
Street Standards (LUCASS). Thicker pavement sections would be expected for higher
volume collector or arterial streets. Collector streets are required to include at least 5 inches
of HBP.
A final pavement evaluation and geotechnical engineering exploration will be required in
general accordance with City of Fort Collins standards after utility infrastructure has been
installed and the subgrade section is at or near “final subgrade” elevations. Pavement
sections determined at that time will be based on in-situ prepared subgrades and traffic
volumes determined by City of Fort Collins. The sections determined at that time could be
greater than the preliminary pavement sections provided with this report.
GENERAL COMMENTS
The preliminary 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. This report is preliminary in nature and, as such, is
not suitable for use in any final design. Site-specific explorations will be required to develop
final site-specific recommendations for each of the site buildings and infrastructure in
pavements.
This report has been prepared for the exclusive use of Imago Enterprises, Inc. 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.
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:
LEE - MLD
FORT COLLINS, COLORADO
EEC PROJECT NO. 1132018
APRIL 2013
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
TOPSOIL & VEGETATION _ _
1
Clayey SAND (SC) _ _
loose, brown, moist, fine-grained sand, trace gravel 2
_ _
CS 3 7 5500 13.4 113.9 27 12 36.2 <500 psf None
_ _
4
_ _
SS 5 5 2000 10.7
_ _
6
_ _
7
_ _
8
_ _
9
_ _
Poorly graded SAND with silt and gravel (SP-SM) CS 10 31 -- 5.0 121.9
dense to medium dense, brown, moist to wet _ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 17 -- 13.3
_ _
16
_ _
17
_ _
18
Silty SAND with gravel (SM) _ _
loose, brown, wet, some clay seams 19
_ _
SS 20 6 -- 14.2
_ _
BOTTOM OF BORING DEPTH 20.5' 21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
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
TOPSOIL & VEGETATION _ _
1
Clayey Sand (SC) _ _
loose, brown, moist, fine-grained sand, trace gravel 2
_ _
3
_ _
4
_ _ Soluble Sulfates = 11.8 mg/kg
CS 5 7 6500 16.5 110.9
_ _
6
_ _
7
_ _
8
_ _
9
_ _
Poorly graded SAND with silt and gravel (SP-SM) CS 10 41 -- 2.4 122.5
dense to medium dense, dry to wet, brown _ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 15 -- 10.1
_ _
16
_ _
17
_ _
18
Poorly graded SAND with silt and gravel (SP-SM) _ _
loose, brown, wet 19
_ _
SS 20 5 -- 9.3
_ _
BOTTOM OF BORING DEPTH 20.5' 21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
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
TOPSOIL & VEGETATION _ _
1
Clayey SAND (SC) _ _
loose, brown, moist, fine-grained sand, trace gravel 2
_ _
3
_ _
4
_ _
CS 5 7 9000+ 9.5 112.4 20 3 40.9 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 25 -- 6.6
Poorly graded SAND with silt and gravel (SP-SM) _ _
medium dense to loose, brown, moist to wet 11
_ _
12
_ _
13
_ _
14
_ _
CS 15 5 -- 16.6 111.4
_ _
16
_ _
17
_ _
18
_ _
19
_ _
clayey SAND seam SS 20 9 -- 14.2
_ _
BOTTOM OF BORING DEPTH 20.5' 21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
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
TOPSOIL & VEGETATION _ _
1
Clayey SAND (SC) _ _
loose, reddish brown, moist, fine-grained sand, 2
trace gravel _ _
3
_ _
4
_ _
CS 5 5 1500 20.6 98.3
_ _
6
_ _
7
_ _
8
_ _
9
_ _ Soluble Sulfates = 11.8 mg/kg
Poorly graded SAND with silt and gravel (SP-SM) SS 10 35 -- 2.8
demse to medium dense, brown / red / grey, _ _
moist to wet, some sandy clay seams 11
_ _
12
_ _
13
_ _
14
_ _
SS 15 21 -- 13.1
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 11 -- 14.9
_ _
BOTTOM OF BORING DEPTH 20.5' 21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
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 % @ 150 PSF
TOPSOIL & VEGETATION _ _
1
FILL - Clayey SAND (SC) _ _
medium dense to loose, mottled brown, dry, 2
fine-grained sand, trace gravel _ _
CS 3 26 -- 4.0 118.7 23 13 37.8 <150 psf 9.3%
_ _
4
_ _
SS 5 6 9000+ 10.4
_ _
6
_ _
7
_ _
8
_ _
Poorly graded SAND with silt and gravel (SP-SM) 9
very dense to medium dense, brown, dry to wet, _ _
fine to coarse sand CS 10 57 -- 1.6 129.7
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 20 -- 11.1
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 8 -- 18.8
Silty SAND (SM), loose, brown, wet _ _
BOTTOM OF BORING DEPTH 20.5' 21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Clayey SAND (SC), brown, moist, fine-grained sand, trace gravel
Sample Location: Boring 1, Sample 1, Depth 2'
Liquid Limit: 27 Plasticity Index: 12 % Passing #200: 36.2%
Beginning Moisture: 13.4% Dry Density: 117.1 pcf Ending Moisture: 13.7%
Swell Pressure: <500 psf % Swell @ 500: None
LEE - MLD Lot 2
Fort Collins, Colorado
1132018
April 2013
-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:
LEE - MLD Lot 2
Fort Collins, Colorado
1132018
April 2013
Beginning Moisture: 9.5% Dry Density: 111.3 pcf Ending Moisture: 16.6%
Swell Pressure: <500 psf % Swell @ 500: None
Sample Location: Boring 3, Sample 1, Depth 4'
Liquid Limit: 20 Plasticity Index: 3 % Passing #200: 40.9%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Clayey SAND (SC), brown, moist, fine-grained sand, trace gravel
-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: Clayey SAND (SC), brown, dry, fine-grained sand, trace gravel
Sample Location: Boring 5, Sample 1, Depth 2'
Liquid Limit: 23 Plasticity Index: 13 % Passing #200: 37.8%
Beginning Moisture: 4.0% Dry Density: 122.2 pcf Ending Moisture: 14.5%
Swell Pressure: <150 psf % Swell @ 150: 9.3%
LEE - MLD Lot 2
Fort Collins, Colorado
1132018
April 2013
-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
SURFACE ELEV N/A WATER 4-18-13 11.8'
FINISH DATE 4/8/2013 WATER 4-10-13 12.5'
SHEET 1 OF 1 WATER DEPTH
START DATE 4/8/2013 WHILE DRILLING 11.5'
LEE MLD LOT 2
FORT COLLINS, COLORADO
PROJECT NO: 1132018 LOG OF BORING B-5 (PIEZOMETER) APRIL 2013
SURFACE ELEV N/A WATER 4-18-13 12.6'
FINISH DATE 4/8/2013 WATER 4-10-13 12.5'
SHEET 1 OF 1 WATER DEPTH
START DATE 4/8/2013 WHILE DRILLING 11.0'
LEE MLD LOT 2
FORT COLLINS, COLORADO
PROJECT NO: 1132018 LOG OF BORING B-4 (PIEZOMETER) APRIL 2013
SURFACE ELEV N/A WATER 4-18-13 12.6'
FINISH DATE 4/8/2013 WATER 4-10-13 12.2'
SHEET 1 OF 1 WATER DEPTH
START DATE 4/8/2013 WHILE DRILLING 12.0'
LEE MLD LOT 2
FORT COLLINS, COLORADO
PROJECT NO: 1132018 LOG OF BORING B-3 (PIEZOMETER) APRIL 2013
SURFACE ELEV N/A WATER 4-18-13 12.3'
FINISH DATE 4/8/2013 WATER 4-10-13 11.8'
SHEET 1 OF 1 WATER DEPTH
START DATE 4/8/2013 WHILE DRILLING 11.5'
LEE MLD LOT 2
FORT COLLINS, COLORADO
PROJECT NO: 1132018 LOG OF BORING B-2 (PIEZOMETER) APRIL 2013
SURFACE ELEV N/A WATER 4-18-13 10.7'
FINISH DATE 4/8/2013 WATER 4-10-13 10.9'
SHEET 1 OF 1 WATER DEPTH
START DATE 4/8/2013 WHILE DRILLING 11.0'
LEE MLD LOT 2
FORT COLLINS, COLORADO
PROJECT NO: 1132018 LOG OF BORING B-1 (PIEZOMETER) APRIL 2013
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