HomeMy WebLinkAboutHARMONY COTTAGES (AFFORDABLE HOUSING) - PDP - PDP150030 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT4396 GREENFIELD DRIVE
WINDSOR, COLORADO 80550
(970) 545-3908 FAX (970) 663-0282
November 30, 2015
Habitat for Humanity
c/o JB Consulting Services
1619 Streamside Drive
Fort Collins, Colorado 80525
Attn: Mr. John Barberio (johnb@jbconsultingservices.com)
Re: Geotechnical Exploration Report
Habitat for Humanity
West Harmony Road and South Taft Hill Road
Fort Collins, Colorado
EEC Project No. 1152114
Mr. Barberio:
Earth Engineering Consultants, LLC (EEC) personnel have completed the supplemental
geotechnical exploration for the proposed Habitat for Humanity project at the southeast corner of
West Harmony Road and South Taft Hill Road in Fort Collins. A geotechnical exploration on
this property was completed by others in 2005. The supplemental exploration was completed to
help evaluate current conditions at the site to provide updated recommendations considering
current site conditions and current codes and standards. The subsurface exploration completed
as a part of the 2005 exploration on this property was evaluated and considered when developing
the recommendations contained in this report.
We understand this project involves development of approximately 21 duplex buildings on the
referenced parcel for Habitat for Humanity. The new buildings are expected to be single story or
two-story wood-framed structures, a portion of which may include basements. We anticipate
maximum wall and column loads be on the order of 2½ kips per lineal foot and 50 kips,
respectively. Small grade changes are expected to develop the site grades. On-site paved drive
and parking areas will be constructed as a part of this project. The site layout for the proposed
development is indicated on the attached boring location diagram.
As a part of the 2005 geotechnical exploration, nine (9) soil borings were completed on this
property extending to depths ranging from approximately 10 to 25 feet below current site grades.
To develop supplemental, current geotechnical data, four (4) additional borings were advanced to
depths of approximately 15 feet below present site grades. The locations of the previously
Earth Engineering Consultants, LLC
Habitat for Humanity
November 30, 2015
Page 2
completed and currently completed exploration borings are indicated on the attached boring
location diagram. The locations of those borings should be considered accurate only to the
degree implied by the methods used to make the field measurements.
To develop additional information on groundwater levels, field slotted PVC piezometers were
installed at the four (4) boring locations completed as a part of the current exploration. Those
temporary piezometers were monitored for an approximate 2-week period after installation.
Results of the field monitoring are indicated on the upper right hand corner of the boring logs.
Moisture content tests and visual/tactual evaluation of recovered samples was completed in the
laboratory as a part of the geotechnical evaluation. Dry density tests were completed on selected
samples and the unconfined strength of appropriate samples was estimated using a calibrated
hand penetrometer. Swell/consolidation tests were completed on selected samples to evaluate
the soils’ tendency to change volume with variation in moisture content and load. Results of the
outlined tests are indicated on the attached boring logs and summary sheets.
Based on results of the field borings and laboratory testing, subsurface conditions can be
generalized as follows. Sparse vegetation and/or topsoil was observed at ground surface at the
boring locations. The vegetation/topsoil in borings P-1, P-2 and P-3 were underlain by brown to
reddish brown sandy lean clay. The sandy lean clay in boring P-3 transitioned to clayey sand at
a depth of approximately 4 feet and in boring P-2 to sands and gravels at a depth of
approximately 12 feet. Sand and gravel was encountered beneath the vegetation/topsoil in
boring P-4 extending to a depth of approximately 10 feet. Claystone, siltstone bedrock was
encountered beneath the overburden soils in borings P-1, P-3 and P-4 at depths ranging from
approximately 9½ to 14½ feet. The overburden lean clay soils showed low to moderate
plasticity and low to moderate swell potential with the underlying claystone, siltstone bedrock
exhibiting high plasticity and high swell. Test borings were terminated at depths of
approximately 15 feet below present site grades in claystone bedrock (borings P-1, P-3 and P4)
or sands and gravel (boring P-2).
Groundwater observations were completed at the time of drilling and in the field slotted PVC
piezometers for approximately 2 weeks after installation. No free water was observed in the test
borings at the time of completion or in the field piezometers during the monitoring period.
Earth Engineering Consultants, LLC
Habitat for Humanity
November 30, 2015
Page 3
Zones of perched and/or trapped water may be encountered at times throughout the year in more
permeable zones in the subgrade soils. Perched groundwater is commonly encountered in soils
overlying less permeable weathered bedrock. Fluctuations in the location and amount of perched
water can also vary over time depending on variations in hydrologic conditions and other
conditions not apparent at the time of this report.
ANALYSIS AND RECOMMENDATIONS
General Observations
The near surface cohesive soils show low to moderate plasticity and low to moderate swell
potential at current moisture and density conditions. Those conditions are somewhat variable
across the site. To reduce the potential for post-construction heaving of site improvements,
moderately expansive soils in building and pavement areas should be removed, moisture
conditioned and replaced as controlled fill. The depth of the overexcavations could vary across
the site depending on the expansion potential of the subgrade soils and on acceptable movement
in floor slabs and pavement areas.
The underlying claystone bedrock also shows moderate to high swell potential and moderate to
high plasticity. As such, care should be taken to maintain separation from the bedrock for any
below grade areas to reduce potential for post-construction heaving of foundations and/or floor
slabs. In general, a separation of 4 feet from the bedrock surface should be maintained for
footings and floor slabs.
Site Preparation
All existing vegetation and/or topsoil should be removed from site improvement areas. In
addition, any moderately expansive cohesive soils should also be removed. The site cohesive
soils could be reused as fill in the improvement areas although care will be necessary to see that
acceptable moisture contents are maintained in the subgrade soils prior to completion of the
overlying improvements to maintain low swell potential for foundation, floor slab and pavement
support.
Earth Engineering Consultants, LLC
Habitat for Humanity
November 30, 2015
Page 4
After stripping and removing all moderately expansive materials and prior to placement of any
fill, floor slab or pavements, we recommend the in-place soils be scarified to a minimum depth
of 9 inches, adjusted in moisture content and compacted to at least 95% of the material’s
standard Proctor maximum dry density as determined in accordance ASTM Specification D698.
The moisture content of the scarified material should be adjusted to within the range of ±2% of
standard Proctor optimum moisture at the time of compaction.
Fill soils required to develop the site subgrades should consist of approved, low volume change
materials which are free from organic matter and debris. We believe the site materials could be
used for general site fill although care will be necessary to maintain the moisture in the subgrade
soils to reduce potential for post-construction movement/heaving of the overlying improvements.
Site cohesive materials should be placed in loose lifts not to exceed 9 inches thick, adjusted in
moisture content as recommended for the scarified soils and compacted to be at least 95% of
standard Proctor maximum dry density.
Care should be taken after placement of fill materials to avoid disturbing the in-place materials
and to prevent wetting and drying of those materials. Soils which are disturbed by the
construction activities or materials which become wet and unstable or dry and desiccated should
be removed and replaced or reworked in place prior to placement of the overlying improvements.
Foundations
Based on materials observed at the boring locations, in our opinion, the site structures could be
supported on conventional footing foundations bearing in the natural stiff to very stiff sandy lean
clay soils or medium dense granular soils. For design of footing foundations bearing on suitable
stiff to very stiff low volume change natural lean clays or medium dense granular to essentially
granular soils, we recommend using a net allowable total load soil bearing pressure not to exceed
1,500 psf. The net bearing pressure refers to the pressure at foundation bearing level in excess of
the minimum surrounding overburden pressure. A minimum dead load pressure would not be
required in the low volume change cohesive soils or essentially non-volume change granular
soils.
Earth Engineering Consultants, LLC
Habitat for Humanity
November 30, 2015
Page 5
Exterior foundations and foundations in unheated areas should be located at least 30 inches
below adjacent exterior grades to provide frost protection. Footing foundations should maintain
a separation of at least 4 feet from the underlying claystone bedrock. We recommend formed
continuous footings 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 footing foundations are supported on
suitable strength natural soils. Soils which are loosened or disturbed by the construction
activities or materials which become dry and desiccated or wet and softened should be removed
and replaced with acceptable backfill soils prior to construction of the footing foundations.
We estimate the long-term settlement of footing foundations designed and constructed as
outlined above would be less than 1 inch.
Floor Slabs
Floor slab subgrades should be prepared as outlined above for site preparation. Care should be
taken after preparation of the floor slab subgrades to prevent wetting or drying of the prepared
materials. Cohesive subgrade soils which are allowed to become dry and desiccated can result in
increased swell potential and heaving of floor slabs supported on those materials. Care should
also be taken to avoid disturbing the in-place subgrade materials and to prevent wetting or drying
of the subgrades.
Below Grade Areas
We recommend a perimeter drain system be installed around all below grade areas to intercept
surface infiltration and prevent surface infiltration water from entering the below grade areas. In
general a perimeter drain system would consist of perforated metal or plastic pipe placed around
the exterior perimeter of the below grade area and sloped to drain to a sump area where it can be
removed without reverse flow into the system. The drain line should be surrounded by an
appropriate/granular filter material to prevent fines from entering the system.
Earth Engineering Consultants, LLC
Habitat for Humanity
November 30, 2015
Page 6
Below grade walls would be subject to lateral earth pressures. We recommend using an at-rest
lateral earth pressure for design of the below grade walls which are restrained from movement.
For backfill soils consisting of the site cohesive materials, we recommend using an equivalent
fluid pressure of 60 pounds pcf assuming positive drainage to prevent development of
hydrostatic loads on below grade walls. Surcharge loads, point loads, or hydrostatic loads would
be an addition to the recommended equivalent fluid pressure. The outlined equivalent fluid
pressure does not include a factor of safety nor an allowance for hydrostatic loads.
Seismic
The site subgrades are variable with layered cohesive and granular soils overlying claystone
bedrock. The depth to the bedrock is variable. Based on the 2012 International Building Code,
we recommend a Site Classification of D be used for seismic design.
Site Pavements
We anticipate site pavements be private paved drives with low volumes of predominately light
traffic. However, some truck traffic, including weekly trash pick-up would be anticipated to
utilize the site pavements.
Subgrades for the pavements should be prepared as outlined in the Site Preparation section of
this report. Cohesive subgrade soils at elevated moisture contents can result in
instability/pumping of the subgrades. If instability is noted in the pavement subgrades at the
time of paving, consideration could be given to stabilizing the subgrades with the addition of
Class C fly ash. Structural credit for a fly ash subgrade could be considered in design of the
pavement sections, although with the minimum pavement design proposed, the use of a
stabilized subgrade would not reduce the overlying pavement sections.
We recommend pavement sections consist of at least 4 inches of hot bituminous pavement
(HBP) overlying 6 inches of aggregate base coarse (ABC). As an alternative, a section of 5½
inches Portland cement concrete could also be used. In the turnaround area at the west end of the
site, thicker pavement sections would be appropriate and we suggest consideration be given to
Earth Engineering Consultants, LLC
Habitat for Humanity
November 30, 2015
Page 7
Portland cement concrete in this area to help resist degradation from any trash truck traffic.
Pavements should be designed in accordance with Larimer County Urban Area Street Standards.
Other Considerations
Positive drainage should be developed across and away from the pavements and away from the
residences to prevent wetting of the subgrade and varying materials. If subgrade of varying
materials become wetted subsequent to construction, it can result in premature failure of the
overlying improvements. We recommend at least 1 inch per foot for the first 10 feet away from
the structures in landscape areas although flatter slopes with positive drainage could be used in
hardscape areas.
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 earthwork phases to
help determine that the design requirements are fulfilled.
This report has been prepared for the exclusive use of Habitat for Humanity c/o JB Consulting
Services for specific application to the project discussed and has been prepared in accordance
with generally accepted geotechnical engineering practices. No warranty, expressed 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
Earth Engineering Consultants, LLC
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.
Group
Symbol
Group Name
Cu≥4 and 1<Cc≤3
E GW Well-graded gravel
F
Cu<4 and/or 1>Cc>3
E GP Poorly-graded gravel
F
Fines classify as ML or MH GM Silty gravel
G,H
Fines Classify as CL or CH GC Clayey Gravel
F,G,H
Cu≥6 and 1<Cc≤3
E SW Well-graded sand
I
Cu<6 and/or 1>Cc>3
E SP Poorly-graded sand
I
Fines classify as ML or MH SM Silty sand
G,H,I
Fines classify as CL or CH SC Clayey sand
G,H,I
inorganic PI>7 and plots on or above "A" Line CL Lean clay
K,L,M
PI<4 or plots below "A" Line ML Silt
K,L,M
organic Liquid Limit - oven dried Organic clay
K,L,M,N
Liquid Limit - not dried Organic silt
K,L,M,O
inorganic PI plots on or above "A" Line CH Fat clay
K,L,M
PI plots below "A" Line MH Elastic Silt
K,L,M
organic Liquid Limit - oven dried Organic clay
K,L,M,P
Liquid Limit - not dried Organic silt
K,L,M,O
Highly organic soils PT Peat
(D30)2
D10 x D60
GW-GM well graded gravel with silt NPI≥4 and plots on or above "A" line.
GW-GC well-graded gravel with clay OPI≤4 or plots below "A" line.
GP-GM poorly-graded gravel with silt PPI plots on or above "A" line.
GP-GC poorly-graded gravel with clay QPI plots below "A" line.
SW-SM well-graded sand with silt
SW-SC well-graded sand with clay
SP-SM poorly graded sand with silt
SP-SC poorly graded sand with clay
Earth Engineering Consultants, LLC
IIf soil contains >15% gravel, add "with gravel" to
group name
JIf Atterberg limits plots shaded area, soil is a CL-
ML, Silty clay
unified soil classification system
Soil Classification
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests
Sands 50% or more
coarse fraction
1
2
P-2
TB #1
TB #3
P-1 TB #4
TB #2
TB #6
TB #8
TB #7
P-3
P-4
TB #9
TB #5
Boring Location Diagram
Habitat for Humanity - Ft Collins, Colorado
EEC Project Number: 1152114
November 2015
EARTH ENGINEERING CONSULTANTS, LLC
TB #1 through TB #9: Approximate
Test Boring Locations Completed
by Others
Legend
P-1 through P-4: Approximate
Piezometer Boring Locations
1 Site Photos
(Photos taken in approximate location, in direction
of arrow)
HABITAT FOR HUMANITY
FORT COLLINS, COLORADO
EEC PROJECT NO. 1152114
NOVEMBER 2015
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
brown / red 2
stiff to very stiff _ _ % @ 150 psf
with calcareous deposits CS 3 22 9000+ 15.2 104.9 39 17 54.3 1200 psf 1.2%
_ _
4
_ _
SS 5 18 7000 7.8
_ _
6
_ _
7
_ _
8
cemented zone _ _
9
_ _
CS 10 35 9000+ 7.8 127.7 31 19 67.6 >8000 psf 14.0%
CLAYSTONE / SILTSTONE _ _
brown / grey / rust 11
with calcareous deposits _ _
12
_ _
13
_ _
14
_ _
SS 15 50 9000+ 15.0
_ _
BOTTOM OF BORING DEPTH 15.5' 16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
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 / red _ _
very stiff to stiff 2
with traces of gravel _ _
3
_ _
4
_ _
CS 5 16 9000+ 7.5 112.6 29 14 28.4 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
red _ _
with calcareous deposits SS 10 11 2000 18.0
_ _
11
_ _
12
_ _
SAND & GRAVEL (SP/GP) 13
red _ _
medium dense 14
_ _
CS 15 32 -- 3.4 122.2
BOTTOM OF BORING DEPTH 15.0' _ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
very stiff _ _ % @ 150 psf
with traces of gravel CS 3 36 9000+ 5.9 127.8 28 15 53.1 1300 psf 3.2%
_ _
4
_ _
CLAYEY SAND (SC) SS 5 18 9000+ 7.0
brown / red _ _
medium dense to dense 6
_ _
7
_ _
8
cemented zone _ _
9
red, with gravel _ _
CS 10 45 9000 2.1 131.5
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CLAYSTONE / SILTSTONE SS 15 35/8" 9000+ 15.6
brown / grey / rust _ _
BOTTOM OF BORING DEPTH 15.5' 16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
SAND & GRAVEL (SP/GP) _ _
brown / red 2
medium dense _ _
3
_ _
4
_ _
CS 5 14 -- 2.8 28 14 14.1
_ _
6
_ _
7
_ _
8
_ _
9
CLAYEY SAND & GRAVEL (SC), brown / red _ _
SS 10 38/10" 9000+ 13.8
CLAYSTONE _ _
brown / grey / rust 11
_ _
12
_ _
13
_ _
14
_ _
CS 15 50/5" 9000+ 12.1 123.4
BOTTOM OF BORING DEPTH 15.0' _ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Red Sandy Lean Clay (CL)
Sample Location: Boring 1, Sample 1, Depth 2'
Liquid Limit: 39 Plasticity Index: 17 % Passing #200: 54.3%
Beginning Moisture: 15.2% Dry Density: 101.3 pcf Ending Moisture: 25.5%
Swell Pressure: 1200 psf % Swell @ 150: 1.2%
Habitat for Humanity - Harmony & Taft
Fort Collins, Colorado
1152114
November 2015
-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:
Habitat for Humanity - Harmony & Taft
Fort Collins, Colorado
1152114
November 2015
Beginning Moisture: 7.8% Dry Density: 132 pcf Ending Moisture: 17.6%
Swell Pressure: >8,000 psf % Swell @ 500: 14.0%
Sample Location: Boring 1, Sample 3, Depth 9'
Liquid Limit: 31 Plasticity Index: 19 % Passing #200: 67.6%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown/Grey/Rust Claystone/Siltstone
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
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 / Red Sandy Lean Clay (CL)
Sample Location: Boring 2, Sample 1, Depth 4'
Liquid Limit: 29 Plasticity Index: 14 % Passing #200: 28.4%
Beginning Moisture: 7.5% Dry Density: 123.3 pcf Ending Moisture: 13.5%
Swell Pressure: <500 psf % Swell @ 500: None
Habitat for Humanity - Harmony & Taft
Fort Collins, Colorado
1152114
November 2015
-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 Sandy Lean Clay (CL)
Sample Location: Boring 3, Sample 1, Depth 2'
Liquid Limit: 28 Plasticity Index: 15 % Passing #200: 53.1%
Beginning Moisture: 5.9% Dry Density: 124.8 pcf Ending Moisture: 13.6%
Swell Pressure: 1300 psf % Swell @ 150: 3.2%
Habitat for Humanity - Harmony & Taft
Fort Collins, Colorado
1152114
November 2015
-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 24 HOUR None
FINISH DATE 11/11/2015 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 11/11/2015 WHILE DRILLING None
HABITAT FOR HUMANITY - HARMONY & TAFT
FORT COLLINS, COLORADO
PROJECT NO: 1152114 LOG OF BORING P-4 (PIEZOMETER) NOVEMBER 2015
SURFACE ELEV N/A 24 HOUR None
FINISH DATE 11/11/2015 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 11/11/2015 WHILE DRILLING None
HABITAT FOR HUMANITY - HARMONY & TAFT
FORT COLLINS, COLORADO
PROJECT NO: 1152114 LOG OF BORING P-3 (PIEZOMETER) NOVEMBER 2015
SURFACE ELEV N/A 24 HOUR None
FINISH DATE 11/11/2015 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 11/11/2015 WHILE DRILLING None
HABITAT FOR HUMANITY - HARMONY & TAFT
FORT COLLINS, COLORADO
PROJECT NO: 1152114 LOG OF BORING P-2 (PIEZOMETER) NOVEMBER 2015
SURFACE ELEV N/A 24 HOUR None
FINISH DATE 11/11/2015 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 11/11/2015 WHILE DRILLING None
HABITAT FOR HUMANITY - HARMONY & TAFT
FORT COLLINS, COLORADO
PROJECT NO: 1152114 LOG OF BORING P-1 (PIEZOMETER) NOVEMBER 2015
passes No. 4 sieve
Fine-Grained Soils
50% or more passes
the No. 200 sieve
<0.75 OL
Gravels with Fines
more than 12%
fines
Clean Sands Less
than 5% fines
Sands with Fines
more than 12%
fines
Clean Gravels Less
than 5% fines
Gravels more than
50% of coarse
fraction retained on
No. 4 sieve
Coarse - Grained Soils
more than 50%
retained on No. 200
sieve
CGravels with 5 to 12% fines required dual symbols:
Kif soil contains 15 to 29% plus No. 200, add "with sand"
or "with gravel", whichever is predominant.
<0.75 OH
Primarily organic matter, dark in color, and organic odor
ABased on the material passing the 3-in. (75-mm)
sieve
ECu=D60/D10 Cc=
HIf fines are organic, add "with organic fines" to
group name
LIf soil contains ≥ 30% plus No. 200 predominantly sand,
add "sandy" to group name.
MIf soil contains ≥30% plus No. 200 predominantly gravel,
add "gravelly" to group name.
DSands with 5 to 12% fines require dual symbols:
BIf field sample contained cobbles or boulders, or
both, add "with cobbles or boulders, or both" to
group name. FIf soil contains ≥15% sand, add "with sand" to
GIf fines classify as CL-ML, use dual symbol GC-
CM, or SC-SM.
Silts and Clays
Liquid Limit less
than 50
Silts and Clays
Liquid Limit 50 or
more
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110
PLASTICITY INDEX (PI)
LIQUID LIMIT (LL)
ML OR OL
MH OR OH
For Classification of fine-grained soils and
fine-grained fraction of coarse-grained
soils.
Equation of "A"-line
Horizontal at PI=4 to LL=25.5
then PI-0.73 (LL-20)
Equation of "U"-line
Vertical at LL=16 to PI-7,
then PI=0.9 (LL-8)
CL-ML
HARDNESS AND DEGREE OF CEMENTATION:
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