HomeMy WebLinkAboutGULLEY DURAN SINGLE-FAMILY RESIDENCE - PDP / FDP - FDP180021 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTMay 22, 2018
Beth Gulley (beth@gulleygreenhouse.com)
726 Laporte Avenue
Fort Collins, CO 80521
Re: Geotechnical Subsurface Exploration
Proposed Gulley Residence
Parcel #9610400006
Larimer County, Colorado
EEC Project No. 18-01-066
Ms. Gulley:
Earth Engineering Company, Inc. (EEC) personnel have completed the geotechnical subsurface
exploration you requested for the proposed single-family residence to be constructed in an area
northwest of the intersection of South Shields Street and West Trilby Road to the west of Gulley’s
Greenhouse south of Fort Collins in Larimer County, Colorado. Results of our subsurface
exploration are provided in this report.
We understand the proposed single-family residence will be a one or two-story wood-frame
structure constructed over a crawlspace. We expect foundation loads for the structure would be
light, with continuous wall loads less than 3 kips per lineal foot and individual column loads less
than 50 kips. Small grade changes are expected to develop final site grades for the structure. The
residence is expected to utilize an on-site wastewater treatment system (OWTS).
The purpose of this report is to describe the subsurface conditions encountered in the test borings
and test pit completed within the identified building envelope on the site and provide geotechnical
recommendations for design and construction of foundations and support of floor slabs and
exterior flatwork. The results of site percolation testing are also included.
The referenced lot is located on a parcel in an area northwest of the intersection of South Shields
Street and West Trilby Road south of Fort Collins in Larimer County, Colorado. The referenced
building site had slight to moderate slopes toward the south and east and was vegetated at the time
of our field work.
To develop information on existing subsurface conditions in the area of the proposed residence,
two soil borings were extended to depths of approximately 20 and 35 feet below present site grades
Earth Engineering Company, Inc.
EEC Project No. 18-01-066
May 22, 2018
Page 2
within the designated building envelope. One (1) additional test boring and test pit to a depth of
approximately 8 feet and three (3) percolation test holes to depths of approximately 3 feet were
advanced in the identified area of the OWTS to develop percolation and soil profile information.
The locations of the test borings and test pit were established in the field by the homeowner.
The borings were performed using a truck-mounted, rotary-type 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 Specification D-1586. All samples obtained in the field were sealed and returned to the
laboratory for further examination, classification and testing.
An EEC field engineer was on site during drilling to evaluate the subsurface conditions
encountered and direct the drilling activities. Field boring logs were prepared based on observation
of disturbed samples and auger cuttings. Based on results of the field borings and laboratory
testing, subsurface conditions in the proposed residence location can be summarized as follows:
Grey/tan and rust sandstone/claystone bedrock was encountered at the surface at the boring
locations. The moderately plastic sandstone/claystone bedrock encountered in the borings was
moderately hard to hard in consistency with depth and exhibited a low to moderate potential for
swelling with variation in moisture content at current moisture/density conditions. The
sandstone/claystone bedrock extended to the bottom of borings at a depth of approximately 20 and
35 feet below present site grades.
Observations were made while drilling and approximately 24 hours after completion of the borings
to determine the presence and depth to the hydrostatic groundwater table. At the time of drilling
and approximately 24 hours after drilling, free water was not observed in the borings completed
on the property.
Longer-term observations in holes which are cased and sealed from the influence of surface water
would be required to more accurately determine fluctuations in groundwater levels over time.
Fluctuations in groundwater levels can occur based on hydrologic conditions and other conditions
not apparent at the time of this report. Zones of perched and/or trapped water may also be
encountered in more permeable zones within the subgrade soils at times throughout the year.
Earth Engineering Company, Inc.
EEC Project No. 18-01-066
May 22, 2018
Page 3
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 indistinct. Bedrock
classification was based on visual and tactual observations of disturbed samples and auger cuttings;
coring and/or petrographic analysis may reveal other rock types. In addition, the soil borings
provide an indication of subsurface conditions at the test locations. However, subsurface
conditions may vary in relatively short distances away from the borings. Potential variations in
subsurface conditions can best be evaluated by close observation and testing of the subgrade
materials during construction. If significant variations from the conditions anticipated from the
test borings appear evident at that time, it may be necessary to re-evaluate the recommendations
provided in this report.
ANALYSIS AND RECOMMENDATIONS
General
The materials encountered in the soil borings completed in the approximate location of the
residence consisted of sandstone/claystone bedrock. Portions of the near surface soils exhibited a
low to moderate swell potential with increases in moisture content. Foundation elements supported
on moderate to highly expansive materials would be expected to experience post-construction
heaving. We typically recommend drilled pier foundations and structural basement floors in
similar subsurface conditions in order to reduce the potential for foundation and floor slab
movement subsequent to construction. Presented below are our recommendations for construction
of the residence using drilled pier foundations. It should be noted that construction in areas with
expansive soils and bedrock carries with it inherent risks regardless of the foundation type chosen.
Those risks include post-construction movement of foundations, floor slabs, exterior flatwork and
other site improvements.
Drilled Pier Foundations
Based on the materials observed in the test borings, it is our opinion the proposed lightly loaded
single-family residential structure could be supported on drilled pier foundations. We recommend
those drilled pier foundations extend to bear at least 28 feet below finished top-of-pier elevation
or extend into the underlying sandstone/claystone bedrock stratum at least 15 feet, whichever
results in the longer drilled pier. For design of drilled pier foundations bearing in the moderately
hard claystone bedrock, we recommend using a total load end bearing pressure not to exceed 25
Earth Engineering Company, Inc.
EEC Project No. 18-01-066
May 22, 2018
Page 4
kips per square foot. A minimum dead load pressure of 5.0 kips per square foot should be
maintained on the drilled pier foundations.
Additional pier capacity can be developed by extending the drilled piers beyond the recommended
minimum bedrock penetration and taking advantage of additional friction capacity between the
drilled pier and surrounding bedrock. We recommend an allowable friction value of 2.5 kips per
square foot be used for that portion of the drilled pier shaft extending below the upper 15 feet of
the pier. The skin friction on the drilled piers can also be used to offset an inability to develop the
recommended dead load on the piers. We recommend an uplift skin friction value of 1.7 kip per
square foot be used to calculate additional uplift resistance.
The drilled piers should be designed with full-length steel reinforcement to help transmit any
tensile stresses in the drilled pier shafts. Grade beams between the drilled piers should be designed
with a minimum 6-inch void space between the grade beam and underlying subgrade to prevent
heaving of the subgrades causing uplift forces on the bottom of those grade beams. The voids
should be formed using cardboard void boxes or other approved methods to prevent an influx of
debris or soil into the void space beneath the grade beams.
Based on previous experience with similar subsurface conditions in the area and on soil and
groundwater conditions observed at the time of our test borings, we do not anticipate that
temporary casing will be required to prevent an influx of soil and water into the boreholes required
for construction of the drilled piers. Based on previous experience with similar subsurface
conditions in the area and on materials observed in the test borings, we anticipate the drilled piers
could be constructed using conventional augering techniques; however, some difficulty will likely
be encountered when drilling through cemented or hard zones of bedrock where rock bits may be
needed.
At the time of construction, care should be taken to place concrete in the open borings as soon as
practical after completion to prevent sloughing of the sidewalls of the caissons into the open
boreholes and/or drying of the bearing materials. Concrete placed in the drilled piers should have
a slump within the range of 5 to 8 inches to promote complete filling of the drilled shaft excavation
and prevent formation of voids in the shaft concrete. Care should be taken at the time of
construction to avoid "mushrooming" at the top of the drilled pier excavations. The use of sono-
tubes or other approved means may be necessary to maintain a consistent shaft diameter if
sloughing occurs in the near surface soils.
Earth Engineering Company, Inc.
EEC Project No. 18-01-066
May 22, 2018
Page 5
We estimate the long-term movement of drilled caisson foundations designed and constructed as
outlined above would be less than 1-inch. Developing and maintaining positive drainage away
from the structure and preventing accumulation of water below or adjacent to the building will be
critical for long-term performance of the drilled pier foundations in the expansive claystone
materials.
Garage and Exterior Slab-on-Grade Subgrades
The near surface materials observed in the test borings exhibited a low to moderate potential for
swelling with increase in moisture content. Garage floor slabs and exterior flatwork placed directly
on those materials in their in-situ moisture and density conditions should be expected to heave as
the subgrade soils increase in moisture content. Overexcavation and backfill procedures would be
required to reduce the potential for swelling of those subgrades subsequent to construction.
Overexcavation and backfill procedures would consist of excavating a zone of the in-situ material
from beneath garage floor slab or flatwork subgrades, moisture conditioning the excavated
materials to be within –1% to +3% of the material’s optimum moisture content and placement of
the backfill soils in loose lifts not to exceed 9 inches in thickness and compacted to be within the
range of 94% to 98% of the material’s maximum dry density as determined by the standard Proctor
procedure (ASTM D-698). Overexcavation and backfill procedures as outlined above would
reduce the potential for post construction heaving of the overlying flatwork; however, significant
heaving of the site improvements could occur and should be expected.
All existing vegetation and/or topsoil should be removed from the flatwork areas. After stripping
and completing all cuts and prior to placement of any fill or flatwork, as a minimum for subgrade
preparation, we recommend the in-place soils be scarified to a depth of 9 inches, adjusted in
moisture content and compacted to be within the range of 94% to 98% of the material's maximum
dry density as determined in accordance with ASTM Specification D-698, the standard Proctor
procedure. The moisture content of the scarified soils should be adjusted to be within the range of
–1% to +3% of standard Proctor optimum moisture at the time of compaction. Severe post-
construction movement of slabs and flatwork supported on a scarified subgrade as outlined above
should be expected.
Fill soils required to develop the subgrade should consist of approved, low-volume change
materials which are free from organic matter and debris. The on-site sandstone/claystone bedrock
should not be used as backfill in this area. Imported structural fill or an approved low swell
Earth Engineering Company, Inc.
EEC Project No. 18-01-066
May 22, 2018
Page 6
material could be used as fill. We recommend fill soils be placed in loose lifts not to exceed 9
inches thick, adjusted in moisture content as recommended for the scarified materials and
compacted to be within the range of 94% to 98% of the material's standard Proctor maximum dry
density.
After preparation of the subgrades, care should be taken to avoid disturbing the in-place materials.
In addition, care should be taken to avoid excessive drying of the site cohesive materials. Soils
which become loosened or disturbed or materials which become dry and desiccated or wet and
softened should be removed and replaced or reworked in place prior to placement of the overlying
improvements.
Post-construction movement of the exterior flatwork should be expected as the subgrade soils
expand with increasing moisture content. Overexcavation/backfill procedures as outlined above
could be used to reduce the potential for post-construction movement of the exterior slabs-on-
grade; however, that risk cannot be eliminated.
Below Grade Areas
We recommend installing a perimeter drain system around all below grade areas to reduce the
potential for development of hydrostatic loads on the below grade walls and to help prevent
accumulation of infiltration water in below grade areas. In general, a perimeter drain system
should consist of perforated metal or plastic pipe placed at approximate foundation bearing level
around the exterior perimeter of the structure. The drainline should be surrounded by a minimum
of 6 inches of appropriately-sized granular filter soil. The filter soil or the drainline should be
surrounded by a filter fabric to help reduce the potential infiltration of fines into the drain system.
The drainline should be sloped to provide gravity flow of water to a sump or gravity outfall where
reverse flow cannot occur into the system.
Backfill placed adjacent to the below grade walls should consist of approved, cohesive low-
volume-change soils which are free from organic matter and debris. The on-site
sandstone/claystone bedrock should not be used as backfill in this area. If free draining granular
soils are used as backfill adjacent to the below grade areas, we recommend the top 2 feet of material
be an essentially cohesive material to help reduce the potential for immediate surface water
infiltration into the backfill. The backfill soils should be placed in loose lifts not to exceed 9 inches
thick, adjusted to within -1 to +3% of optimum moisture content and compacted to be within the
range 94 to 98% of the material's standard Proctor maximum dry density.
Earth Engineering Company, Inc.
EEC Project No. 18-01-066
May 22, 2018
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Care should be taken in placing and compacting the wall backfill to avoid placing undue lateral
stress on the below grade walls. We recommend compacting with light mechanical or hand
compaction equipment.
For design of below grade walls where appropriate steps have been taken to eliminate hydrostatic
loads, we recommend using an equivalent fluid pressure of 55 pounds per square foot per foot of
depth. The recommended design equivalent fluid pressure is based on an active stress distribution
case where slight rotation is expected in the below grade walls. The rotation expected to develop
an active stress distribution case results in deflection on the wall of approximately 0.5% times the
height of the wall. That deflection may result in stress cracks on the interior of the basement walls,
particularly near the center of spans between corners or other restrained points. The recommended
equivalent fluid pressure does not include a factor of safety or an allowance for hydrostatic loads.
Surcharge loads placed adjacent to below grade walls or point loads placed in the wall backfill
may add to the lateral pressures on below grade walls.
Other Considerations
Positive drainage should be developed away from the structure with a minimum slope of 1 inch
per foot for the first 10 feet away from the building. Care should be taken in planning of
landscaping adjacent to the residence to avoid features which would pond water adjacent to the
foundations or stemwalls. Plants which require an irrigation system and/or cause substantial
fluctuations in the moisture content of the subgrade soils should not be placed adjacent to the
structure. Lawn watering systems should not be placed within 5 feet of the perimeter of the
building. Spray heads should be designed to spray water away from the structure. Roof drains
should be designed to discharge at least 5 feet away from the structure and away from paved areas.
Site Percolation Tests
Percolation tests and one 8-feet deep boring and test pit were completed in the identified area of
the proposed individual sewage disposal system. The materials encountered in the test boring and
test pit consisted of brown sandy lean clay soils underlain by grey/tan and rust sandstone/claystone
bedrock at a depth of approximately 5 feet below present site grades which extended to the bottom
of the boring and test pit at a depth of approximately 8 feet below present site grades. An average
percolation rate of 100 minutes per inch was established in the percolation test borings.
Earth Engineering Company, Inc.
EEC Project No. 18-01-066
May 22, 2018
Page 8
The percolation test performed indicated an average percolation rate of 100 minutes per inch.
Larimer County Health Department regulations require a percolation rate between 5 and 60
minutes per inch to use a conventional absorption system. Based upon the visual soil classification,
the site soils classify as sandy clay (Soil Type 4), which corresponds to a percolation rate of 76 to
90 minutes per inch. The measured percolation rate does not meet that criterion. Soil Type 4
classification along with a percolation rate of 76 to 90 minutes per inch should be assumed in the
design. Larimer County guidelines also require that neither groundwater nor bedrock be
encountered within 6 feet of ground surface at the location of an absorption field. The test boring
and test pit completed indicates the near surface site soils do not meet the separation from bedrock
and groundwater criteria. Based on the results as outlined above, it appears an engineered septic
absorption system would be required for the lot. When constructing the absorption field, Larimer
County criteria concerning proximity to property lines, drainage ways and other site features
should be addressed.
GENERAL COMMENTS
The analysis and recommendations presented in this report are based upon the data obtained from
the soil borings and test pit performed at the indicated locations and from any other information
discussed in this report. This report does not reflect any variations which may occur 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 and foundation construction
phases to help determine that the design requirements are fulfilled.
This report has been prepared for the exclusive use of Ms. Beth Gulley 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:
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
Silts and Clays
Liquid Limit 50 or
more
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
GULLEY RESIDENCE
LARIMER COUNTY, CO
EEC PROJECT No. 18-01-066
MAY 2018
GULLEY RESIDENCE
LARIMER COUNTY, CO
EEC PROJECT No. 18-01-066
MAY 2018
GULLEY RESIDENCE
LARIMER COUNTY, COLORADO
PROJECT NO: 18-01-066 DATE: MAY 2018
LOG OF BORING B-1
RIG TYPE: CME75 SHEET 1 OF 1 WATER DEPTH
FOREMAN: SM START DATE 5/1/2018 WHILE DRILLING None
AUGER TYPE: 4" CFA FINISH DATE 5/1/2018 AFTER DRILLING None
SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR None
SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
SANDSTONE/CLAYSTONE 2
grey/tan/rust CS _ _ 50/9" 9000+ 9.9 127.3 28 13 73.7 700 psf 0.3%
moderately hard 4
SS _ _ 50/10" 9000+ 8.2
6
_ _
8
_ _
hard CS 10 50/4" 9000+ 7.5 116.8 2600 psf 2.5%
_ _
12
_ _
14
SS _ _ 50/6" 9000+ 8.6
16
_ _
18
_ _
CS 20 50/5" 9000+ 10.1 125.4 3000 psf 1.3%@1000
20' BOTTOM OF BORING _ _
22
_ _
24
_ _
26
_ _
28
_ _
30
_ _
32
_ _
34
_ _
36
_ _
38
_ _
40
_ _
42
_ _
44
_ _
46
_ _
48
_ _
50
GULLEY RESIDENCE
LARIMER COUNTY, COLORADO
PROJECT NO: 18-01-066 DATE: MAY 2018
LOG OF BORING B-2
RIG TYPE: CME75 SHEET 1 OF 1 WATER DEPTH
FOREMAN: SM START DATE 5/1/2018 WHILE DRILLING None
AUGER TYPE: 4" CFA FINISH DATE 5/1/2018 AFTER DRILLING None
SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR None
SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
SANDSTONE/CLAYSTONE 2
grey/tan/rust CS _ _ 50 9000+ 6.6 126.1 5400 psf 4.3%
moderately hard 4
CS _ _ 50/8" 9000+ 7.0 126.4 3400 psf 3.9%
6
CS _ _ 50/7" 9000+ 8.5 129.5 8400 psf 6.5%
8
_ _
hard CS 10 50/5" 9000+ 7.2 115.8 1400 psf 2.1%
_ _
12
_ _
14
CS _ _ 50/5" 9000+ 7.2 120.7 4400 psf 3.3%@1000
16
_ _
18
_ _
CS 20 50/5" 9000+ 9.8 121.4 < 1000 psf None@1000
_ _
22
_ _
24
CS _ _ 50/5" 9000+ 10.1 117.9 2200 psf 0.8%@1000
26
_ _
28
_ _
30
_ _
32
_ _
34
_ _
35' BOTTOM OF BORING 36
_ _
38
_ _
40
_ _
42
_ _
44
_ _
46
_ _
48
_ _
50
GULLEY RESIDENCE
LARIMER COUNTY, COLORADO
PROJECT NO: 18-01-066 DATE: MAY 2018
LOG OF BORING B-3
RIG TYPE: CME75 SHEET 1 OF 1 WATER DEPTH
FOREMAN: SM START DATE 5/1/2018 WHILE DRILLING None
AUGER TYPE: 4" CFA FINISH DATE 5/1/2018 AFTER DRILLING None
SPT HAMMER: AUTO SURFACE ELEV N/A 24 HOUR None
SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff 4
_ _
SANDSTONE/CLAYSTONE 6
grey/tan/rust _ _
moderately hard 8
8' BOTTOM OF BORING _ _
10
_ _
12
_ _
14
_ _
16
_ _
18
_ _
20
_ _
22
_ _
24
_ _
26
_ _
28
_ _
30
_ _
32
_ _
34
_ _
36
_ _
38
_ _
40
_ _
42
_ _
44
_ _
46
_ _
48
_ _
50
GULLEY RESIDENCE
LARIMER COUNTY, COLORADO
PROJECT NO: 18-01-066 DATE: MAY 2018
LOG OF TEST PIT NO. 1
RIG TYPE: BACKHOE SHEET 1 OF 1 WATER DEPTH
FOREMAN: SM START DATE 5/14/2018 WHILE DRILLING None
AUGER TYPE: N/A FINISH DATE 5/14/2018 AFTER DRILLING None
SPT HAMMER: N/A SURFACE ELEV N/A 24 HOUR N/A
SOIL DESCRIPTION D N QU MC DD A-LIMITS -200 SWELL
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SANDY LEAN CLAY (CL) _ _
brown 2
very stiff BS _ _ -- -- 8.2
calcareous deposits 4
BS _ _ -- -- 8.1 41 31 90.2
SANDSTONE/CLAYSTONE 6
grey/tan/rust BS _ _ -- -- 6.2
moderately hard 8
8' BOTTOM OF TEST PIT _ _
10
_ _
12
_ _
14
_ _
16
_ _
18
_ _
20
_ _
22
_ _
24
_ _
26
_ _
28
_ _
30
_ _
32
_ _
34
_ _
36
_ _
38
_ _
40
_ _
42
_ _
44
_ _
46
_ _
48
_ _
50
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Grey/Tan/Rust Sandstone/Claystone
Sample Location: B-1, S-1 @ 2'
Liquid Limit: 28 Plasticity Index: 13 % Passing #200: 73.7
Beginning Moisture: 9.0% Dry Density: 127.3 pcf Ending Moisture: 12.7%
Swell Pressure: 700 psf % Swell @ 500 psf: 0.3%
Project: Gulley Residence
Larimer County, Colorado
Project No.: 18-01-066
Date: May 2018
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.01 0.1 1 10
Percent Movement
Load (TSF)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Grey/Tan/Rust Sandstone/Claystone
Sample Location: B-1, S-3 @ 9'
Liquid Limit: -- Plasticity Index: -- % Passing #200: --
Beginning Moisture: 7.8% Dry Density: 116.8 pcf Ending Moisture: 15.4%
Swell Pressure: 2600 psf % Swell @ 500 psf: 2.5%
Project: Gulley Residence
Larimer County, Colorado
Project No.: 18-01-066
Date: May 2018
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.01 0.1 1 10
Percent Movement
Load (TSF)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Grey/Tan/Rust Sandstone/Claystone
Sample Location: B-1, S-5 @ 19'
Liquid Limit: -- Plasticity Index: -- % Passing #200: --
Beginning Moisture: 8.3% Dry Density: 125.4 pcf Ending Moisture: 16.5%
Swell Pressure: 3000 psf % Swell @ 1000 psf: 1.3%
Project: Gulley Residence
Larimer County, Colorado
Project No.: 18-01-066
Date: May 2018
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.01 0.1 1 10
Percent Movement
Load (TSF)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Grey/Tan/Rust Sandstone/Claystone
Sample Location: B-2, S-1 @ 2'
Liquid Limit: -- Plasticity Index: -- % Passing #200: --
Beginning Moisture: 6.7% Dry Density: 126.1 pcf Ending Moisture: 12.1%
Swell Pressure: 5400 psf % Swell @ 500 psf: 4.3%
Project: Gulley Residence
Larimer County, Colorado
Project No.: 18-01-066
Date: May 2018
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.01 0.1 1 10
Percent Movement
Load (TSF)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Grey/Tan/Rust Sandstone/Claystone
Sample Location: B-2, S-2 @ 4'
Liquid Limit: -- Plasticity Index: -- % Passing #200: --
Beginning Moisture: 6.5% Dry Density: 126.4 pcf Ending Moisture: 14.3%
Swell Pressure: 3400 psf % Swell @ 500 psf: 3.9%
Project: Gulley Residence
Larimer County, Colorado
Project No.: 18-01-066
Date: May 2018
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.01 0.1 1 10
Percent Movement
Load (TSF)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Grey/Tan/Rust Sandstone/Claystone
Sample Location: B-2, S-3 @ 6'
Liquid Limit: -- Plasticity Index: -- % Passing #200: --
Beginning Moisture: 7.9% Dry Density: 129.5 pcf Ending Moisture: 13.8%
Swell Pressure: 8400 psf % Swell @ 500 psf: 6.5%
Project: Gulley Residence
Larimer County, Colorado
Project No.: 18-01-066
Date: May 2018
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.01 0.1 1 10
Percent Movement
Load (TSF)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Grey/Tan/Rust Sandstone/Claystone
Sample Location: B-2, S-4 @ 9'
Liquid Limit: -- Plasticity Index: -- % Passing #200: --
Beginning Moisture: 7.6% Dry Density: 115.8 pcf Ending Moisture: 18.1%
Swell Pressure: 1400 psf % Swell @ 500 psf: 2.1%
Project: Gulley Residence
Larimer County, Colorado
Project No.: 18-01-066
Date: May 2018
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.01 0.1 1 10
Percent Movement
Load (TSF)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Grey/Tan/Rust Sandstone/Claystone
Sample Location: B-2, S-5 @ 14'
Liquid Limit: -- Plasticity Index: -- % Passing #200: --
Beginning Moisture: 21.4% Dry Density: 120.7 pcf Ending Moisture: 14.3%
Swell Pressure: 4400 psf % Swell @ 1000 psf: 3.3%
Project: Gulley Residence
Larimer County, Colorado
Project No.: 18-01-066
Date: May 2018
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.01 0.1 1 10
Percent Movement
Load (TSF)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Grey/Tan/Rust Sandstone/Claystone
Sample Location: B-2, S-6 @ 19'
Liquid Limit: -- Plasticity Index: -- % Passing #200: --
Beginning Moisture: 9.5% Dry Density: 121.4 pcf Ending Moisture: 16.0%
Swell Pressure: < 1000 psf % Swell @ 1000 psf: None
Project: Gulley Residence
Larimer County, Colorado
Project No.: 18-01-066
Date: May 2018
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.01 0.1 1 10
Percent Movement
Load (TSF)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Grey/Tan/Rust Sandstone/Claystone
Sample Location: B-2, S-7 @ 24'
Liquid Limit: -- Plasticity Index: -- % Passing #200: --
Beginning Moisture: 8.6% Dry Density: 117.9 pcf Ending Moisture: 15.7%
Swell Pressure: 2200 psf % Swell @ 1000 psf: 0.8%
Project: Gulley Residence
Larimer County, Colorado
Project No.: 18-01-066
Date: May 2018
-10
-8
-6
-4
-2
0
2
4
6
8
10
0.01 0.1 1 10
Percent Movement
Load (TSF)
Water Added
Consolidation Swell
No. 4 4.75
No. 10 2
No. 40 0.425
No. 200 0.075
Project:
City Location: Larimer County, Colorado
Project Number: 18-01-066
Date: May 2018
100%
No. 200 90%
Sieve Size Percent Passing
No. 4
98%
100%
No. 40
Description:
Earth Engineering Company, Inc.
Summary of Laboratory Gradation Test
Grey/Tan/Rust Sandstone/Claystone
Gulley Residence
Sample Location: TP-1, S-2 @ 4'
No. 10
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
90.0%
100.0%
100 10 1 0.1 0.01 0.001
Percent Finer by Weight
Grain Size in Millimeters
Earth Engineering Company
Earth Engineering Company
Earth Engineering Company
Earth Engineering Company
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
Unified Soil ClaSSifiCation SyStem
Soil Classification
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests
Sands 50% or more
coarse fraction
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
Silts and Clays
Liquid Limit less
than 50
IIf soil contains >15% gravel, add "with gravel" to
group name
JIf Atterberg limits plots shaded area, soil is a CL-
ML, Silty clay
GIf fines classify as CL-ML, use dual symbol GC-
CM, or SC-SM.
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
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
Earth Engineering Company