HomeMy WebLinkAboutTHE PARK TOWNHOMES AT FOSSIL RIDGE - Filed SEPD-SURFACE EXPLORATION/PAVEMENT DESIGN REPORT - 2017-12-144396 GREENFIELD DRIVE
WINDSOR, COLORADO 80550
(970) 970-545-3908 FAX (970) 663-0282
www.earth-engineering.com
September 7, 2017
(Revised from August 30, 2017)
Manhattan Land Company, LLC
c/o Cushman & Wakefield
772 Whalers Way #200
Fort Collins, Colorado 80525
Attn: Mr. Russell Baker (Russell.Baker@cushwake.com)
Re: Subsurface Exploration/Pavement Design Report
Ziegler Apartments – 5405 Ziegler Road
Ziegler Road and County Fair Lane Improvements
Fort Collins, Colorado
EEC Project No. 1174067
Mr. Baker:
Earth Engineering Consultants, LLC (EEC) personnel have completed field and laboratory
testing in general accordance with the Larimer County Urban Area Street Standard (LCUASS)
Pavement Design criteria, of in-place subgrades for proposed roadway widening/improvements
along Ziegler Road and County Fair Lane, associated with the Ziegler Apartments development
in Fort Collins, Colorado. At the time of our field exploration, the subgrades for the selected
roadways were near approximate “rough” final subgrade elevations and the main sanitary sewer
and water lines and services had been installed. Results of the subgrade evaluation and
pavement thickness recommendations, based on those test results and estimated 18-kip
equivalent daily load application (EDLA) values for this portion of the development, are
provided with this report.
Pavement related test borings for this evaluation were completed at three (3) locations (identified
herein as P-1 through P-3) to evaluate the subgrade conditions for the proposed roadway
widening/improvements sections. The borings were extended to approximate depths of 5 feet in
the boring located over the sanitary sewer line (boring B-3), and 10 feet in the remaining borings.
A site diagram indicating the approximate roadway alignments evaluated as part of this
assessment and the approximate boring locations are provided with this report. Site photographs
of the property at the time of our exploration are also provided with this report. Test borings
were taken at the points indicated on Ziegler Road and County Fair Lane.
Earth Engineering Consultants, LLC
Ziegler Apartments Pavement Design
EEC Project No. 1174067
September 7, 2017 (Revised from August 30, 2017)
Page 2
Laboratory testing on the recovered samples included moisture content tests of all samples, in-
situ dry density of appropriate samples, and an evaluation of the unconfined strength of selected
samples with a calibrated hand penetrometer. Atterberg limits and washed sieve analysis tests
were completed on selected samples to evaluate the quantity and plasticity of the fines in the
subgrade soils. In addition, swell/consolidation tests were completed on selected samples to
evaluate the soils’ tendency to swell with increased moisture content at current moisture and
density conditions. These swell/consolidation tests were completed with the loading criteria as
recommended in the LCUASS Pavement Design guideline using an inundation/preloading
criteria of 150 psf. Results of the outlined tests are indicated on the attached boring logs and
summary sheets.
As a part of the testing program, all samples were examined in the laboratory and classified in
general accordance with the attached General Notes and the Unified Soil Classification System,
based on the soils’ texture and plasticity. The estimated group symbol for the Unified Soil
Classification System is indicated on the boring logs and a brief description of that classification
system is included with this report.
Based on the results of the field borings and the laboratory testing, subsurface conditions can be
generalized as follows. Subsurface soils observed within the test borings, consisted of either fill
material and/or native soils generally classified as lean clay with sand. The subgrade soils were
generally moist in-situ; were medium stiff to stiff and exhibited low swell potential
characteristics. The lean clay with sand subsoils extended to the bottom of the borings at depths
of approximately 5 to 10 feet below present site grades.
Observations were made while drilling and after completion of the borings to detect the presence
and depth to hydrostatic ground water. No free water was observed in the borings at the time of
drilling to maximum depths of exploration. Fluctuations in groundwater levels can occur over
time depending on variations in hydrologic conditions and other conditions not apparent at the
time of this report. Longer term observations in cased holes sealed from the influence of surface
water would be required to evaluate long term water level fluctuations.
Earth Engineering Consultants, LLC
Ziegler Apartments Pavement Design
EEC Project No. 1174067
September 7, 2017 (Revised from August 30, 2017)
Page 3
ANALYSIS AND RECOMMENDATIONS
Swell – Consolidation Test Results
The swell-consolidation test is performed to evaluate the swell or collapse potential of soils to help
determine foundation, floor slab and pavement design criteria. In this test, relatively intact samples
obtained directly from the California barrel sampler are placed in a laboratory apparatus and
inundated with water under a predetermined load. The swell-index is the resulting amount of swell
or collapse after the inundation period expressed as a percent of the sample’s initial thickness.
Samples obtained at the 1 or 2-foot interval are generally pre-loaded and inundated with water at
an approximate 150 pounds per square foot (psf) increment to simulate the pavement loading
conditions in general accordance with LCUASS Pavement Design criteria. After the inundation
period, additional incremental loads are applied to evaluate swell pressure and consolidation
response as appropriate.
For this assessment, we conducted a total of three (3) swell-consolidation tests on subgrade
samples collected from approximate depths of 1 to 2-feet below existing site grades. The swell
index values for the soil samples tested at the 150-psf inundation pressures revealed relatively
low swell characteristics on the order of (+) 0.9 to (+) 1.5%.
The average swell index for the borings was less than the LCUASS maximum allowable 2%
criteria used to determine if a swell-mitigation plan is necessary. Based on these results, in our
opinion, a swell mitigation plan is not necessary.
Subgrade preparation for the roadways within the Ziegler Apartments development should be
completed in general accordance with the recommendations presented in the LCUASS Pavement
Design Manual – Chapter 22.
Pavement Subgrade Preparation
Based on the testing completed, it appears the in-place cohesive lean clay with sand subgrade
soils could be used for direct support of the roadways and for roadway subgrade fill provided
adequate moisture treatment and compaction procedures are followed. Those procedures would
Earth Engineering Consultants, LLC
Ziegler Apartments Pavement Design
EEC Project No. 1174067
September 7, 2017 (Revised from August 30, 2017)
Page 4
generally include placement in loose lifts not to exceed 9 inches thick and adjustment in moisture
content, 2% of optimum moisture content for generally cohesive type soils or 3% for cleaner
granular type soils, and compaction to at least 95% of the materials maximum dry density as
determined in accordance with ASTM Specification D698, the standard Proctor procedure. If
the site lean clay with sand soils are used as fill material, care will be needed to maintain the
recommended moisture content prior to and during construction of overlying improvements.
All existing vegetation, and apparent unsuitable fill materials should be removed from the site
improvement areas. After removal of unacceptable or unsuitable subsoils, removal of over
excavation materials, and removal of any previous fill material, and prior to placement of fill
and/or site improvements, the exposed soils should be scarified to a depth of 9 inches, adjusted in
moisture content to within (+/-) 2% of standard Proctor optimum moisture content for essentially
cohesive soils or to a workable moisture content for essentially granular materials and compacted
to at least 95% of the material's standard Proctor maximum dry density as determined in
accordance with ASTM Specification D698.
Fill materials used to replace the over excavated zone and establish grades in the
pavement/flatwork areas, after the initial zone has been prepared as recommended above, should
consist of approved on-site soils or imported structural fill material which is free from organic
matter and debris. Approved structural fill materials should be graded similarly to a CDOT
Class 5, 6 or 7 aggregate base with sufficient fines to prevent ponding of water within the fill.
Structural fill material should be placed in loose lifts not to exceed 9 inches thick, adjusted to a
workable moisture content and compacted to at least 95% of standard Proctor maximum dry
density as determined by ASTM Specification D698.
Proofrolling and recompacting the subgrade section is recommended immediately prior to
placement of the aggregate road base section. Soft or weak areas delineated by the proofrolling
operations should be undercut or stabilized in-place to achieve the appropriate subgrade support.
Moisture conditioning the site subgrade soils could result in pumping subgrade conditions with
elevated moisture contents in the subgrades. If pumping is observed, stabilization of the subgrades
with the addition of Class C fly ash would be required. Additional recommendations can be
provided at time of the proof roll observation.
Earth Engineering Consultants, LLC
Ziegler Apartments Pavement Design
EEC Project No. 1174067
September 7, 2017 (Revised from August 30, 2017)
Page 5
Pavement design methods are intended to provide structural sections with adequate thickness over
a particular subgrade such that wheel loads are reduced to a level the subgrade can support. The
support characteristics of the subgrade for pavement design do not account for shrink/swell
movements of a slightly expansive essentially cohesive subgrade or consolidation of a wetted
subgrade. Thus, the pavement may be adequate from a structural standpoint, yet still experience
cracking and deformation due to shrink/swell related movement of the subgrade. It is therefore
important to minimize moisture changes in the subgrade to reduce shrink/swell movements.
Care will be needed after preparation of the subgrades to avoid disturbing the subgrade materials.
Positive drainage should be developed away from the pavements to avoid wetting of subgrade
materials. Subgrade materials becoming wet subsequent to construction of the site improvements
can result in unacceptable performance.
The collection and diversion of surface drainage away from paved areas is critical to the
satisfactory performance of the pavement. Drainage design should provide for the removal of
water from paved areas in order to reduce the potential for wetting of the subgrade soils.
Long-term pavement performance will be dependent upon several factors, including maintaining
subgrade moisture levels and providing for preventive maintenance. The following
recommendations should be considered the minimum:
The subgrade and the pavement surface should be adequately sloped to promote proper surface
drainage.
Install pavement drainage surrounding areas anticipated for frequent wetting (e.g. landscaped
and irrigated islands, etc.),
Install joint sealant and seal cracks immediately,
Seal all landscaped areas in, or adjacent to pavements to minimize or prevent moisture
migration to subgrade soils;
Placing compacted, low permeability backfill against the exterior side of curb and gutter;
and,
Placing curb, gutter, and/or sidewalk directly on approved proof rolled subgrade soils without
the use of base course materials.
Earth Engineering Consultants, LLC
Ziegler Apartments Pavement Design
EEC Project No. 1174067
September 7, 2017 (Revised from August 30, 2017)
Page 6
Site grading is generally accomplished early in the construction phase. However, as construction
proceeds, the subgrade may be disturbed due to utility excavations, construction traffic,
desiccation, or rainfall. As a result, the pavement subgrade may not be suitable for pavement
construction and corrective action will be required. The subgrade should be carefully evaluated at
the time of pavement construction for signs of disturbance, rutting, or excessive drying. If
disturbance has occurred, pavement subgrade areas should be reworked, moisture conditioned, and
properly compacted to the recommendations in this report immediately prior to paving.
Please note that if during or after placement of the stabilization or initial lift of pavement, the area
is observed to be yielding under vehicle traffic or construction equipment, it is recommended that
EEC be contacted for additional alternative methods of stabilization, or a change in the pavement
section.
Pavement – Design and Construction
We understand that Ziegler Road is classified as a minor arterial roadway and a County Fair
Lane is classified as a local minor collector; therefore, Equivalent Daily Load Application
(EDLA) values of 100 and 25 were used, respectively, for pavement design in general
accordance with the LCAUSS criteria. Pavement section recommendations provided in this
report are based on the traffic information outlined and the subgrade field and laboratory test
results as discussed herein.
A Hveem Stabilometer/R-value of 15 was determined for the rough-graded pavement subgrades
for Ziegler Apartments as shown on the summary sheet included with this report. Using the
Colorado Department of Transportation (CDOT) and the current Larimer County Urban Area
Street Standards (LCUASS) Pavement Design Criteria, an R-value of 15 corresponds to a
resilient modulus value of 4195 psi, which was used in the pavement evaluation for the roadways
included herein.
The American Association of State Highway and Transportation Officials (AASHTO) design
guidelines for pavement thicknesses were used to evaluate recommended pavement sections for
this project along with the current LCUASS Pavement Design Criteria. Recommended
Earth Engineering Consultants, LLC
Ziegler Apartments Pavement Design
EEC Project No. 1174067
September 7, 2017 (Revised from August 30, 2017)
Page 7
pavement sections based on those evaluations are provided on the attached summary tables
included with this report.
The aggregate base should meet LCUASS Class 5 or Class 6 specifications. Aggregate base
should be placed and compacted to achieve a minimum density of 95% of standard Proctor
maximum dry density (ASTM Specification D698).
The hot bituminous pavement (HBP) should be grading SX (75) or S (75) with PG 58-28 binder
and should be designed in accordance with LCUASS. The HBP should be compacted to achieve
92-96% of the material’s maximum specific gravity (Rice Value).
The recommended pavement sections provided herein on the enclosed “Minimum Pavement
Thickness Summary Tables” for Ziegler Apartments are minimums and periodic maintenance
should be expected. Since the cohesive soils on the site have some shrink/swell potential,
pavements could crack in the future primarily because of the volume change of the soils when
subjected to an increase in moisture content to the subgrade. The cracking, while not desirable,
does not necessarily constitute structural failure of the pavement. Stabilization of the subgrades
will reduce the potential for cracking of the pavements.
Preventive maintenance should be planned and provided for through an on-going pavement
management program. Preventive maintenance activities are intended to slow the rate of pavement
deterioration, and to preserve the pavement investment. Preventive maintenance consists of both
localized maintenance (e.g. crack and joint sealing and patching) and global maintenance (e.g.
surface sealing). Preventive maintenance is usually the first priority when implementing a planned
pavement maintenance program and provides the highest return on investment for pavements.
Prior to implementing any maintenance, additional engineering observation is recommended to
determine the type and extent of preventive maintenance.
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
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
2
P-1 P-2
P-3
1
Boring Location Diagram
Ziegler Apartments - 5405 Ziegler Road
Fort Collins, Colorado
EEC Project #: 1174067 Date: August 2017
EARTH ENGINEERING CONSULTANTS, LLC
Approximate Boring
Locations
1
Legend
Site Photos
(Photos taken in approximate
location, in direction of arrow)
ZIEGLER APARTMENTS PAVEMENTS
FORT COLLINS, COLORADO
EEC PROJECT NO. 1174067
AUGUST 2017
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
_ _
LEAN CLAY with SAND (CL) 1
brown _ _
medium stiff to stiff 2
_ _ % @ 150 psf
CS 3 8 7000 17.8 104.3 36 20 73.2 800 psf 0.9%
_ _
4
_ _
brown / red SS 5 6 5000 11.0
_ _
6
_ _
7
_ _
8
_ _
9
brown _ _
SS 10 11 9000+ 12.8
_ _
BOTTOM OF BORING DEPTH 10.5' 11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
ZIEGLER APARTMENTS - 5405 ZIEGLER ROAD
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
_ _
LEAN CLAY with SAND (CL) 1
dark brown / rust _ _
stiff to medium stiff 2
_ _ % @ 150 psf
CS 3 9 6500 23.5 99.5 1200 psf 1.5%
_ _
4
brown / rust _ _
SS 5 8 4500 19.0
_ _
6
_ _
7
_ _
8
_ _
9
brown / grey _ _
SS 10 7 2000 17.2
_ _
BOTTOM OF BORING DEPTH 10.5' 11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
ZIEGLER APARTMENTS - 5405 ZIEGLER ROAD
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
_ _
LEAN CLAY with SAND (CL) - FILL 1
brown / rust / grey _ _
stiff to medium stiff 2
_ _ % @ 150 psf
CS 3 10 9000 14.6 111.8 38 23 66.7 1200 psf 1.5%
_ _
4
_ _
SS 5 6 6500 16.7
_ _
BOTTOM OF BORING DEPTH 5.5' 6
_ _
7
_ _
8
_ _
9
_ _
10
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11
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12
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13
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14
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15
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16
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17
_ _
18
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19
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20
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21
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22
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23
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24
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25
_ _
Earth Engineering Consultants, LLC
ZIEGLER APARTMENTS - 5405 ZIEGLER ROAD
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
Sample Location: Boring P1, Sample 1, Depth 2'
Liquid Limit: 36 Plasticity Index: 20 % Passing #200: 73.2%
Beginning Moisture: 17.8% Dry Density: 107.5 pcf Ending Moisture: 21.1%
Swell Pressure: 800 psf % Swell @ 150: 0.9%
Ziegler Apartments - 5405 Ziegler Road
Fort Collins, Colorado
1174067
August 2017
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Dark Brown / Rust Lean Clay with Sand (CL)
Sample Location: Boring P2, Sample 1, Depth 2'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
Beginning Moisture: 23.5% Dry Density: 100.8 pcf Ending Moisture: 25.1%
Swell Pressure: 1200 psf % Swell @ 150: 1.5%
Ziegler Apartments - 5405 Ziegler Road
Fort Collins, Colorado
1174067
August 2017
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Rust / Gray Lean Clay with Sand (CL) - Fill
Sample Location: Boring P3, Sample 1, Depth 2'
Liquid Limit: 38 Plasticity Index: 23 % Passing #200: 66.7%
Beginning Moisture: 14.6% Dry Density: 119.7 pcf Ending Moisture: 16.1%
Swell Pressure: 1200 psf % Swell @ 150: 1.5%
Ziegler Apartments - 5405 Ziegler Road
Fort Collins, Colorado
1174067
August 2017
-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: Ziegler Apartments - Pavement Evaluation PROJECT NO. 1174067
LOCATION: DATE Aug-17
MATERIAL DESCRIPTION: Lean Clay with Sand (CL) - AASHTO A-6
SAMPLE LOCATION:
LIQUID LIMIT: PLASTICITY INDEX: %PASSING #200:
R-VALUE LABORATORY TEST RESULTS
TEST SPECIMEN NO. 1 23
COMPACTION PRESSURE (PSI) 100 125 150
DENSITY (PCF) 113.1 117.0 115.7
MOISTURE CONTENT (%) 15.8 15.0 14.5
EXPANSION PRESSURE (PSI) 0.00 0.00 0.00
HORIZONTAL PRESSURE @ 160 PSI 127 119 119
SAMPLE HEIGHT (INCHES) 2.50 2.57 2.45
EXUDATION PRESSURE (PSI) 265.9 373.6 498.1
UNCORRECTED R-VALUE 13.8 18.4 19.2
CORRECTED R-VALUE 13.8 18.9 19.2
R-VALUE @ 300 PSI EXUDATION PRESSURE = 15 RESILIENT MODULUS, PSI = 4,195
Composite Subgrade Sample - Borings P-1 thru P-3: Upper 5 Feet
RESISTANCE R-VALUE & EXPANSION PRESSURE OF
COMPACTED SOIL - ASTM D2844
Fort Collins, Colorado
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200 250 300 350 400 450 500 550 600
R-Value
Exudation Pressure, PSF
Client: Manhattan Land Company, LLC Project: Ziegler Apartments Pavement Design Project No. 1174067
Subgrade Resilient Modulus: Based on Subgrade R-Value of 15
Minimum Pavement Thicknesses - Inches
Thickness,
Inches Calculated SN Calculated SN Calculated SN Calculated SN
0.44 5.0 2.20 2.86
0.11 6.0 0.66 1.10
-- -- -- -- --
2.86 3.96
MINIMUM PAVEMENT SECTION RECOMMENDATIONS (NON-STABILIZED SUBGRADE)
Roadways
Roadway Classification
Date: 9/7/2017
County Fair Lane
18-kip Equivalent Daily Load Axles (EDLA) 25 100
Ziegler Road
Local Minor Collector Minor Arterial
20-Year 18-kip Equivalent Single Axle Loads (ESAL) 182,500 730,000
Reliability (%) 75 90
Standard Deviation 0.44 0.44
4195 4195
PSI Loss (Initial Serviceability Index - Final Serviceability Index), psi 2.2 2
AASHTO Design Structural Number - SN 2.86 3.93
Composite Pavement Section (Option A)
Thickness,
Inches
Thickness,
Inches
Thickness,
Inches
Hot Bituminous Pavement (Grade S) - Structural Number SN 6.5
Aggregate Base Course (CDOT Class 5 or 6) - Structural No. SN 10.0
Stabilized Subgrade - Fly Ash Treated Subgrade 13% Class C
Calculated Pavement Structural Number - SN
Client: Manhattan Land Company, LLC Project: Ziegler Apartments Pavement Design Project No. 1174067
Subgrade Resilient Modulus: Based on Subgrade R-Value of 15
Minimum Pavement Thicknesses - Inches
Thickness,
Inches Calculated SN Calculated SN Calculated SN Calculated SN
0.44 5.0 2.20 2.64
0.11 6.0 0.66 0.88
0.05 10.0 0.50 0.50
3.36 4.02
Note:
Calculated Pavement Structural Number - SN
1) Calculated SN in RED-TEXT indicates the overall structural number assuming HALF-STRENGTH fly-ash credit, (i.e., assuming
the field compressive strength samples achieve less than 150 psi, then 0.05 strength coefficient is being applied. Please note the
HMA and ABC included herein with fly ash are the LCUASS required minimum thicknesses.
Aggregate Base Course (CDOT Class 5 or 6) - Structural No. SN 8.0
(1)
Stabilized Subgrade - Fly Ash Treated Subgrade 13% Class C 10.0
Composite Pavement Section (Option B)
Thickness,
Inches
Thickness,
Inches
Thickness,
Inches
Hot Bituminous Pavement (Grade S) - Structural Number SN 6.0
PSI Loss (Initial Serviceability Index - Final Serviceability Index), psi 2.2 2
AASHTO Design Structural Number - SN 2.86 3.93
Standard Deviation 0.44 0.44
4195 4195
20-Year 18-kip Equivalent Single Axle Loads (ESAL) 182,500 730,000
Reliability (%) 75 90
Roadway Classification Local Minor Collector Minor Arterial
18-kip Equivalent Daily Load Axles (EDLA) 25 100
MINIMUM PAVEMENT SECTION RECOMMENDATIONS (FLY ASH STABILIZED SUBGRADE)
Date: 9/7/2017
Roadways County Fair Lane Ziegler Road
FORT COLLINS, COLORADO
PROJECT NO: 1174067 LOG OF BORING P-3 AUGUST 2017
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING None
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/18/2017 AFTER DRILLING N/A
A-LIMITS SWELL
FORT COLLINS, COLORADO
PROJECT NO: 1174067 LOG OF BORING P-2 AUGUST 2017
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING None
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/18/2017 AFTER DRILLING N/A
A-LIMITS SWELL
FORT COLLINS, COLORADO
PROJECT NO: 1174067 LOG OF BORING P-1 AUGUST 2017
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING None
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/18/2017 AFTER DRILLING N/A
A-LIMITS SWELL
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
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