HomeMy WebLinkAboutEAST RIDGE SECOND FILING - Filed GR-GEOTECHNICAL REPORT/SOILS REPORT - 2019-06-03Soilogic, Inc.
3522 Draft Horse Court Loveland, CO 80538 (970) 535-6144
May 22, 2019
Bison Ridge Construction, LLC
3524 Draft Horse Court
Loveland, Colorado 80538
Attn: Mr. Guillermo Hernandez
Re: Geotechnical Subsurface Exploration and Pavement Design Report
East Ridge – Filing 2, Phase 2 Pavements
Fort Collins, Colorado
Soilogic Project # 19-2026P
Mr. Hernandez:
Soilogic, Inc. (Soilogic) personnel have completed the geotechnical subsurface
exploration and pavement section design you requested for a portion of Vicot Way
located within Phase 2 of East Ridge Filing 2 in Fort Collins, Colorado. The results of
our subsurface exploration and pertinent geotechnical engineering recommendations are
included with this report.
The purpose of our exploration was to describe the subsurface conditions encountered in
the completed site borings and develop the test data necessary to provide pavement
section design recommendations for construction of a portion of Vicot Way. The
conclusions and recommendations outlined in this report are based on results of the
completed field and laboratory testing and our experience with subsurface conditions in
this area.
The East Ridge Subdivision is located southeast of the intersection of Timberline Road
and Vine Drive in Fort Collins, Colorado. The portion of Vicot way evaluated extends
from Sykes Drive to Comet Street. At the time of our site exploration, the sewer utilities
had been installed where planned and the roadways cut to approximate finish grade.
Moisture/density testing of the overlot fill and utility backfill soils were completed by
Soilogic personnel on a part time basis during placement and compaction and results met
the minimum requirement of at least 95% of the material’s standard Proctor maximum
dry density.
CITY OF FORT COLLINS
APPROVED
06/03/2019
Geotechnical Subsurface Exploration and Pavement Design Report
East Ridge – Filing 2, Phase 2 Pavements
Fort Collins, Colorado
Soilogic # 19-2026P
2
FIELD EXPLORATION
To develop subsurface information for use in the pavement design, a total of 4 borings
were completed. At each of two (2) test locations where sewer utilities were installed as
part of the site development, one (1) boring was advanced over the utility trench area to a
depth of approximately five (5) feet below roadway subgrade level and one (1) boring
advanced outside the utility trench area to a depth of approximately 10 feet. The test
areas were established at approximate 500 foot intervals along the roadway alignments in
accordance with the Larimer County Urban Area Street Standards (LCUASS). The
boring locations were established in the field by Soilogic personnel by pacing and
estimating angles and distances from identifiable site references. A diagram indicating
the approximate boring locations is included with this report. The boring locations
outlined on the attached diagram should be considered accurate only to the degree
implied by the methods used to make the field measurements. Graphic logs of each of
the auger borings are also included.
The test holes were advanced using 4-inch diameter continuous-flight auger powered by a
truck-mounted CME-45 drill rig. Samples of the subsurface materials were obtained at
regular intervals using California barrel sampling procedures in general accordance with
ASTM specification D-1586. As part of the D-1586 sampling procedure, standard
sampling barrels are driven into the substrata using a 140-pound hammer falling a
distance of 30 inches. The number of blows required to advance the sampler a distance
of 12 inches is recorded and helpful in estimating the consistency or relative density of
the soils encountered. In the California barrel sampling procedure, lesser disturbed
samples are obtained in removable brass liners. Samples of the subsurface materials
obtained in the field were sealed and returned to the laboratory for further evaluation,
classification and testing.
LABORATORY TESTING
The samples collected were tested in the laboratory to measure natural moisture content
and visually and/or manually classified in accordance with the Unified Soil Classification
System (USCS). The USCS group symbols are indicated on the attached boring logs. An
outline of the USCS classification system is included with this report.
Geotechnical Subsurface Exploration and Pavement Design Report
East Ridge – Filing 2, Phase 2 Pavements
Fort Collins, Colorado
Soilogic # 19-2026P
3
As part of the laboratory testing, a calibrated hand penetrometer (CHP) was used to
estimate the unconfined compressive strength of essentially-cohesive specimens. The
CHP also provides a more reliable estimate of soil consistency than tactual observation
alone. Dry density, Atterberg limits, -200 wash and swell/consolidation tests were
completed on selected samples to help establish specific soil characteristics. Atterberg
limits tests are used to determine soil plasticity. The percent passing the #200 size sieve
(-200 wash test) is used to determine the percentage of fine-grained soils (clay and silt) in
a sample. Swell/consolidation tests are performed to evaluate soil volume change
potential with variation in moisture content. Swell/consolidation tests completed on
samples obtained at a depth of approximately 2 feet below ground surface were inundated
with water at a 150 psf confining pressure while samples obtained at a depth of
approximately 4 feet below ground surface were inundated at a 500 psf confining
pressure. The results of the completed laboratory tests are outlined on the attached
boring logs, swell/consolidation summary sheets.
SUBSURFACE CONDITIONS
The subsurface materials encountered in the completed site borings can be summarized as
follows. Light brown to brown clayey sand with varying amounts of silt and gravel was
encountered at the surface at the boring locations. A portion of the near-surface clayey
sand appeared to be utility backfill. The clayey sand varied from loose to medium dense
in terms of relative density, exhibited no to low swell potential at in-situ moisture and
density conditions and extended to the bottom of all borings at depths ranging from
approximately 5 to 10 feet below present site grade.
The stratigraphy indicated on the included boring logs represents the approximate
location of changes in soil types. Actual changes may be more gradual than those
indicated.
Groundwater was not encountered in the completed site borings at the time of drilling.
Groundwater levels will vary seasonally and over time based on weather conditions, site
development, irrigation practices and other hydrologic conditions. Perched and/or
trapped groundwater conditions may also be encountered at times throughout the year.
Perched water is commonly encountered in soils overlying less permeable soil layers
Geotechnical Subsurface Exploration and Pavement Design Report
East Ridge – Filing 2, Phase 2 Pavements
Fort Collins, Colorado
Soilogic # 19-2026P
4
and/or bedrock. Trapped water is typically encountered within more permeable zones of
layered soil and bedrock systems. The location and amount of perched/trapped water can
also vary over time.
ANALYSIS AND RECOMMENDATIONS
Pavement Subgrade Development/Fly Ash Stabilization
At this time, we expect fly ash stabilization of the pavement subgrade soils may be
completed for the Phase 6 roadways. For fly ash stabilization, we recommend the
addition of 12% Class ‘C’ fly ash based on component dry unit weights. A 12-inch thick
stabilized zone should be constructed by thoroughly blending the fly ash with the in-place
subgrade soils. Some “fluffing” of the finish subgrade level should be expected with the
stabilization procedures. The blended materials should be adjusted in moisture content to
within the range of ±2% of standard Proctor optimum moisture content and compacted to
at least 95% of the material’s standard Proctor maximum dry density within two (2) hours
of fly ash addition.
Pavement Design
The clayey sand subgrade soils encountered in the completed site borings exhibited no to
low swell potential at in-situ moisture and density conditions, and in our opinion, could
be used for support of a composite pavement section on stabilized subgrade. Care should
be taken to avoid disturbing the fly ash-treated subgrade soils prior to paving. As a
precaution, we recommend proof-rolling of the roadway subgrade soils be completed
prior to aggregate base course placement to help identify unstable areas. Unstable areas
should be mended prior to surfacing.
The clayey sand subgrade soils classify as A-6 soils in accordance with The American
Association of State Highway and Transportation Officials (AASHTO) classification
system and would be expected to exhibit low to moderate remolded shear strength. An
R-value of 17 was determined on a representative subgrade sample obtained from the
development site and used in pavement section design. Design ESAL’s were provided by
City of Fort Collins personnel. Serviceability loss and reliability were obtained from the
current LCUASS.
Geotechnical Subsurface Exploration and Pavement Design Report
East Ridge – Filing 2, Phase 2 Pavements
Fort Collins, Colorado
Soilogic # 19-2026P
5
Outlined below in Table I. are proposed pavement section designs for the subject
roadways. Alternative pavement sections could be considered and we would be happy to
discuss any design alternatives at your request.
TABLE 1 – PAVEMENT SECTION DESIGN
Roadway
Classification
ESAL’s
Reliability
% Loss
Resilient Modulus (Mr)
Design Structural Number
Option A – Composite
Asphalt (Grading S or SX)
Aggregate Base (Class 6)
(Structural Number)
Option B – Composite on Fly Ash
Asphalt (Grading S or SX)
Aggregate Base (Class 6)
Fly Ash Treated Subgrade
(Structural Number)
Vicot Way
Local Residential
36,500
75%
2.5
4478
(2.16)
*4” (0.44/inch)
*6” (0.11/inch)
(2.42)
*4” (0.44/inch)
*6” (0.11/inch)
12” (10 @ .05/inch)
(2.70)
* - Minimum section required by the City of Fort Collins
Asphaltic concrete should consist of a bituminous plant mix composed of a mixture of
aggregate, filler, binders and additives if required meeting the design requirements of the
City of Fort Collins. Aggregate used in the asphaltic concrete should meet specific
gradation requirements such as Colorado Department of Transportation (CDOT) grading
S (3/4 inch minus) or SX (1/2 inch minus) specifications. Asphalt used in the hot mix
should consist of performance graded PG (58-28), or as specified by the Local agency,
for local residential roadways. Hot mix asphalt designed using “Superpave” criteria
should be compacted to within 92 to 96% of the materials Maximum Theoretical Density.
Aggregate base should be consistent with CDOT requirements for Class 5 or 6 aggregate
base, placed in loose lifts not to exceed 9 inches thick, adjusted to within ±2% of the
material’s standard Proctor optimum moisture content and compacted to at least 95% of
the materials standard Proctor maximum dry density.
Geotechnical Subsurface Exploration and Pavement Design Report
East Ridge – Filing 2, Phase 2 Pavements
Fort Collins, Colorado
Soilogic # 19-2026P
6
The proposed pavement section designs do not include an allowance for excessive
loading conditions imposed by heavy construction vehicles or equipment. Heavily
loaded concrete or other building material trucks and construction equipment can cause
some localized distress to the roadway pavements.
Drainage
Positive drainage is imperative for satisfactory long term performance of the roadway
pavements. Water which is allowed to pond adjacent to site pavements can result in a
loss of subgrade support and premature failure of the overlying pavement section.
LIMITATIONS
This report was prepared based upon the data obtained from the completed site
exploration, laboratory testing, engineering analysis and any other information discussed.
The completed borings provide an indication of subsurface conditions at the boring
locations only. Variations in subsurface conditions can occur in relatively short distances
away from the borings. This report does not reflect any variations which may occur
across the site or away from the borings. If variations in the subsurface conditions
anticipated become evident, the geotechnical engineer should be notified immediately so
that further evaluation and supplemental recommendations can be provided.
The scope of services for this project does not include either specifically or by
implication any biological or environmental assessment of the site or identification or
prevention of pollutants or hazardous materials or conditions. Other studies should be
completed if concerns over the potential of such contamination or pollution exist.
The geotechnical engineer should be retained to review the plans and specifications so
that comments can be made regarding the interpretation and implementation of our
geotechnical recommendations in the design and specifications. The geotechnical
engineer should also be retained to provide testing and observation services during
construction to help determine that the design requirements are fulfilled.
Geotechnical Subsurface Exploration and Pavement Design Report
East Ridge – Filing 2, Phase 2 Pavements
Fort Collins, Colorado
Soilogic # 19-2026P
7
This report has been prepared for the exclusive use of our client for specific application
to the project discussed and has been prepared in accordance with the generally accepted
standard of care for the profession. No warranties express or implied, are made. The
conclusions and recommendations contained in this report should not be considered valid
in the event that any changes in the nature, design or location of the project as outlined in
this report are planned, unless those changes are reviewed and the conclusions of this
report modified and verified in writing by the geotechnical engineer.
We appreciate the opportunity to be of service to you on this project. If you have any
questions concerning the enclosed information or if we can be of further assistance to you
in any way, please do not hesitate to contact us.
Very Truly Yours,
Soilogic, Inc. Reviewed by:
Wolf von Carlowitz, P.E. Darrel DiCarlo, P.E.
Principal Engineer Senior Project Engineer
44271
36746
LOG OF BORING B-1A
1/1 CME 45
4" CFA
Automatic
JL/BM
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
-
1
CL FILL - CLAYEY SAND -
light brown to brown 2
medium dense -
3 CS 16 7.6 121.3 9000+ - - - - -
-
4
-
5 CS 18 10.9 119.3 9000+ None <500 - - -
BOTTOM OF BORING 5.0' -
6
-
7
-
8
-
9
-
10
-
11
-
12
-
13
-
14
-
15
-
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
Sheet Drilling Rig: Water Depth Information
EAST RIDGE - FILING 2, PHASE 2 PAVEMENTS
LOG OF BORING B-1B
1/1 CME 45
4" CFA
Automatic
JL/BM
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
-
1
-
SC-CL light brown to brown 2
brown/olive -
loose to medium dense 3 CS 22 11.0 108.5 9000+ 1.9% 2000 23 6 47.4%
-
4
-
5 CS 13 9.7 119.4 9000+ - - - - -
-
6
-
7
-
8
-
9
-
10 CS 10 3.3 113.9 9000+ - - - - -
BOTTOM OF BORING 10.0' -
11
-
12
-
13
-
14
-
15
-
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
Sheet Drilling Rig: Water Depth Information
EAST RIDGE - FILING 2, PHASE 2 PAVEMENTS
LOG OF BORING B-2A
1/1 CME 45
4" CFA
Automatic
JL/BM
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
-
1
CL FILL - CLAYEY SAND -
light brown to brown 2
loose to medium dense -
3 CS 16 5.9 108.4 9000+ 0.9% - - - -
With Gravel -
4
-
5 CS 13 10.0 95.4 9000+ - - - - -
BOTTOM OF BORING 5.0' -
6
-
7
-
8
-
9
-
10
-
11
-
12
-
13
-
14
-
15
-
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
24 Hours After Drilling -
USCS
LOG OF BORING B-2B
1/1 CME 45
4" CFA
Automatic
JL/BM
Estimated Swell % Passing
SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve
(ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%)
-
1
-
SC light brown to brown 2
brown/olive -
medium dense 3 CS 38 5.1 117.6 9000+ - - - - -
-
4
-
5 CS 23 8.4 96.8 9000+ 0.3% 600 - - -
-
6
-
7
-
8
-
9
-
10 CS 18 2.5 116.3 9000+ - - - - -
BOTTOM OF BORING 10.0' -
11
-
12
-
13
-
14
-
15
-
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
24 Hours After Drilling -
USCS
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density (pcf) 119.3
Final Moisture 12.9%
% Swell @ 500 psf None
Swell Pressure (psf) <500
Sample ID: B-1A @ 4
Sample Description: Fill - Light Brown to Brown Clayey Sand (SC)
Initial Moisture 10.9%
SWELL/CONSOLIDATION TEST SUMMARY
EAST RIDGE - FILING 2, PHASE 2 PAVEMENTS
FORT COLLINS, COLORADO
Project # 19-2026P
May 2019
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit 23
Plasticity Index 6
% Passing #200 47.4%
Dry Density (pcf) 108.5
Final Moisture 19.9%
% Swell @ 150 psf 1.9%
Swell Pressure (psf) 2,000
Initial Moisture 11.0%
Sample ID: B-1B @ 2
Sample Description: Light Brown to Brown Clayey Sand (SC)
SWELL/CONSOLIDATION TEST SUMMARY
EAST RIDGE - FILING 2, PHASE 2 PAVEMENTS
FORT COLLINS, COLORADO
Project # 19-2026P
May 2019
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density (pcf) 108.4
Final Moisture 15.0%
% Swell @ 150 psf 0.9%
Swell Pressure (psf) -
Initial Moisture 5.9%
Sample ID: B-2A @ 2
Sample Description: Fill - Light Brown to Brown Clayey Sand (SC)
SWELL/CONSOLIDATION TEST SUMMARY
EAST RIDGE - FILING 2, PHASE 2 PAVEMENTS
FORT COLLINS, COLORADO
Project # 19-2026P
May 2019
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
Liquid Limit -
Plasticity Index -
% Passing #200 -
Dry Density (pcf) 96.8
Final Moisture 24.0%
% Swell @ 500 psf 0.3%
Swell Pressure (psf) 600
Initial Moisture 8.4%
Sample ID: B-2B @ 4
Sample Description: Light Brown to Brown Clayey Sand (SC)
SWELL/CONSOLIDATION TEST SUMMARY
EAST RIDGE - FILING 2, PHASE 2 PAVEMENTS
FORT COLLINS, COLORADO
Project # 19-2026P
May 2019
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
10 100 1000 10000 100000
---------
Applied Load (psf)
UNIFIED SOIL CLASSIFICATION SYSTEM
Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Soil Classification
Group
Symbol
Group NameB
Clean Gravels Cu ! 4 and 1 " Cc " 3E GW Well graded gravelF
Less than 5% finesC Cu
< 4 and/or 1 > Cc > 3E GP Poorly graded gravelF
Fines classify as ML or MH GM Silty gravelF,G, H
Coarse Grained Soils
More than 50% retained
on No. 200 sieve
Gravels
More than 50% of coarse
fraction retained on
No. 4 sieve Gravels with Fines More
than 12% finesC Fines classify as CL or CH GC Clayey gravelF,G,H
Clean Sands Cu ! 6 and 1 " Cc " 3E SW Well graded sandI
Less than 5% finesD Cu
< 6 and/or 1 > Cc > 3E SP Poorly graded sandI
Fines classify as ML or MH SM Silty sandG,H,I
Sands
50% or more of coarse
fraction passes
No. 4 sieve Sands with Fines
More than 12% finesD Fines classify as CL or CH SC Clayey sandG,H,I
Silts and Clays PI > 7 and plots on or above “A” lineJ CL Lean clayK,L,M
Liquid limit less than 50
Inorganic
PI < 4 or plots below “A” lineJ ML SiltK,L,M
Liquid limit - oven
dried
Organic clayK,L,M,N
Fine-Grained Soils
50% or more passes the
No. 200 sieve
Organic
Liquid limit - not
dried
< 0.75 OL
Organic siltK,L,M,O
Inorganic PI plots on or above “A” line CH Fat clayK,L,M
Silts and Clays
Liquid limit 50 or more
PI plots below “A” line MH Elastic siltK,L,M
Organic Liquid limit - oven dried Organic clayK,L,M,P
Liquid limit - not dried
< 0.75 OH
Organic siltK,L,M,Q
Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat
A Based on the material passing the 3-in. (75-mm) sieve
B If field sample contained cobbles or boulders, or both, add “with cobbles
or boulders, or both” to group name.
C Gravels with 5 to 12% fines require dual symbols: GW-GM well graded
gravel with silt, GW-GC well graded gravel with clay, GP-GM poorly
graded gravel with silt, GP-GC poorly graded gravel with clay.
D Sands with 5 to 12% fines require dual symbols: 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
E Cu = D60/D10 Cc =
GENERAL NOTES
DRILLING & SAMPLING SYMBOLS:
SS: Split Spoon - 1⅜" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger
ST: Thin-Walled Tube – 2.5" O.D., unless otherwise noted PA: Power Auger
RS: Ring Sampler - 2.42" I.D., 3" O.D., unless otherwise noted HA: Hand Auger
CS: California Barrel - 1.92" I.D., 2.5" O.D., unless otherwise noted RB: Rock Bit
BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary
The number of blows required to advance a standard 2-inch O.D. split-spoon sampler (SS) the last 12 inches of the total 18-inch
penetration with a 140-pound hammer falling 30 inches is considered the “Standard Penetration” or “N-value”. For 2.5” O.D.
California Barrel samplers (CB) the penetration value is reported as the number of blows required to advance the sampler 12
inches using a 140-pound hammer falling 30 inches, reported as “blows per inch,” and is not considered equivalent to the
“Standard Penetration” or “N-value”.
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 Casing Removal
Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other
times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater.
In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-term observations.
DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils
have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand.
Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally 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 in-place relative density and fine-grained soils on the basis of their consistency.
FINE-GRAINED SOILS COARSE-GRAINED SOILS BEDROCK
(CB)
Blows/Ft.
(SS)
Blows/Ft.
Consistency
(CB)
Blows/Ft.
(SS)
Blows/Ft.
Relative
Density
(CB)
Blows/Ft.
(SS)
Blows/Ft.
Consistency
< 3 0-2 Very Soft 0-5 < 3 Very Loose < 24 < 20 Weathered
3-5 3-4 Soft 6-14 4-9 Loose 24-35 20-29 Firm
6-10 5-8 Medium Stiff 15-46 10-29 Medium Dense 36-60 30-49 Medium Hard
11-18 9-15 Stiff 47-79 30-50 Dense 61-96 50-79 Hard
19-36 16-30 Very Stiff > 79 > 50 Very Dense > 96 > 79 Very Hard
> 36 > 30 Hard
RELATIVE PROPORTIONS OF SAND AND
GRAVEL
GRAIN SIZE TERMINOLOGY
Descriptive Terms of
Other Constituents
Percent of
Dry Weight
Major Component
of Sample
Particle Size
Trace < 15 Boulders Over 12 in. (300mm)
With 15 – 29 Cobbles 12 in. to 3 in. (300mm to 75 mm)
Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75 mm)
Sand
Silt or Clay
#4 to #200 sieve (4.75mm to 0.075mm)
Passing #200 Sieve (0.075mm)
RELATIVE PROPORTIONS OF FINES PLASTICITY DESCRIPTION
Descriptive Terms of
Other Constituents
Percent of
Dry Weight
Term Plasticity Index
Trace
With
Modifiers
< 5
5 – 12
> 12
Non-plastic
Low
Medium
High
0
1-10
11-30
30+
F If soil contains ! 15% sand, add “with sand” to group name.
G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.
HIf fines are organic, add “with organic fines” to group name.
I If soil contains ! 15% gravel, add “with gravel” to group name.
J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.
K If soil contains 15 to 29% plus No. 200, add “with sand” or “with
gravel,” whichever is predominant.
L If soil contains ! 30% plus No. 200 predominantly sand, add
“sandy” to group name.
M If soil contains ! 30% plus No. 200, predominantly gravel, add
“gravelly” to group name.
N PI ! 4 and plots on or above “A” line.
O PI < 4 or plots below “A” line.
P PI plots on or above “A” line.
Q PI plots below “A” line.
Sampler
Atterberg Limits
Surface Elev. - Field Personnel:
Start Date 5/6/2019 Auger Type: During Drilling None
Finish Date 5/6/2019 Hammer Type: After Drilling None
Sheet Drilling Rig: Water Depth Information
EAST RIDGE - FILING 2, PHASE 2 PAVEMENTS
FORT COLLINS, COLORADO
Project # 19-2026P
May 2019
Sampler
Atterberg Limits
Surface Elev. - Field Personnel:
Start Date 5/6/2019 Auger Type: During Drilling None
Finish Date 5/6/2019 Hammer Type: After Drilling None
Sheet Drilling Rig: Water Depth Information
EAST RIDGE - FILING 2, PHASE 2 PAVEMENTS
FORT COLLINS, COLORADO
Project # 19-2026P
May 2019
FORT COLLINS, COLORADO
Project # 19-2026P
May 2019
USCS
Sampler
Atterberg Limits
Start Date 5/6/2019 Auger Type: During Drilling None
Finish Date 5/6/2019 Hammer Type: After Drilling None
Surface Elev. - Field Personnel: 24 Hours After Drilling -
FORT COLLINS, COLORADO
Project # 19-2026P
May 2019
USCS
Sampler
Atterberg Limits
Start Date 5/6/2019 Auger Type: During Drilling None
Finish Date 5/6/2019 Hammer Type: After Drilling None
Surface Elev. - Field Personnel: 24 Hours After Drilling -