HomeMy WebLinkAboutELIZABETH & CITY PARK CORNER REDEVELOPMENT - FDP - FDP120003 - SUBMITTAL DOCUMENTS - ROUND 1 - RECOMMENDATION/REPORTPRELIMINARY GEOTECHNICAL EXPLORATION REPORT
1401 WEST ELIZABETH STREET REDEVELOPMENT
FORT COLLINS, COLORADO
EEC PROJECT NO. 1122010
Prepared for:
Elizabeth & City Park Corner, LLC
1107 City Park Avenue
Fort Collins, Colorado 80521
Attn: Ms. Betty Aris – betty@campuswestliquors.com
Prepared by:
Earth Engineering Consultants, Inc.
4396 Greenfield Drive
Windsor, Colorado 80550
4396 GREENFIELD DRIVE
WINDSOR, COLORADO 80550
(970) 545-3908 FAX (970) 663-0282
February 7, 2012
Elizabeth & City Park Corner, LLC
1107 City Park Avenue
Fort Collins, Colorado 80521
Attn: Ms. Betty Aris – betty@campuswestliquors.com
Re: Preliminary Geotechnical Exploration Report
1401 West Elizabeth Street Redevelopment
Fort Collins, Colorado
EEC Project No. 1122010
Ms. Aris:
Enclosed, herewith, are the results of the preliminary geotechnical evaluation for the
proposed redevelopment of the former Consuelo’s Mexican Restaurant site at 1401 West
Elizabeth Street in Fort Collins, Colorado. Two (2) soil borings extending to depths of
approximately 15 to 25 feet below present site grades were advanced on this property to
develop information on existing subsurface conditions. Individual boring logs and a
diagram indicating the approximate boring locations are included with this report.
We understand this project involves the redevelopment of 1401 West Elizabeth Street.
The existing structure on that site will be razed to make room for the new building. The
new building is anticipated to be a single story, slab-on-grade, lightly loaded structure. In
general, the subsurface conditions encountered at the boring locations included a
relatively stiff brown sandy lean clay, above a layer of sand and gravel, overlying
siltstone/claystone/sandstone bedrock. The near surface cohesive soils show moderate
plasticity and low swell potential at current moisture and density conditions.
Based on results of the field borings and laboratory testing, we anticipate the new
structure could be supported on conventional footing foundations bearing in the near
surface natural lean clay soils or newly placed fill materials. We anticipate the floor
could also be supported on the in-place natural soils or suitable fill materials placed to
develop the floor slab subgrades. Care will be necessary to see that all existing site
PRELIMINARY GEOTECHNICAL EXPLORATION REPORT
1401 WEST ELIZABETH STREET REDEVELOPMENT
FORT COLLINS, COLORADO
EEC PROJECT NO. 1122010
February 7, 2012
INTRODUCTION
The preliminary geotechnical exploration requested for the proposed redevelopment of 1401 West
Elizabeth Street in Fort Collins, Colorado, has been completed. As a part of that exploration, two (2)
soil borings were extended to depths of approximately 15 to 25 feet below present site grades to
develop information on existing subsurface conditions. Individual boring logs and a diagram
indicating the approximate boring locations are included with this report.
We understand this project involves the redevelopment of 1401 West Elizabeth Street. An existing
building which formerly housed Consuelo’s Mexican Restaurant is currently located on the site. We
understand that building will be razed prior to construction of the new structure. The new building
is expected to be single story, slab-on-grade with a plan area of approximately 7,200 square feet.
The structure is expected to be concrete block or steel stud perimeter and will be lightly loaded.
Floor loads will also be light. We understand the structure will be situated to the north side of the
site with the long access (N120 feet) parallel to West Elizabeth Street. We anticipate the south
portion of the site will be paved parking and drive for automobiles and light trucks.
The purpose of this report is to describe the subsurface conditions encountered in test borings,
analyze and evaluate the test data, and provide preliminary geotechnical recommendations for the
proposed redevelopment.
EXPLORATION AND TESTING PROCEDURES
The approximate boring locations were field located by estimating the boring locations relative to
the existing site improvements. The locations of the borings should be considered accurate only to
the degree implied the methods used to make the field measurements. Photographs at the site taken
at the time of the field drilling are included with this report.
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
Earth Engineering Consultants, Inc.
EEC Project No. 1122010
February 7, 2012
Page 2
nominal diameter continuous flight augers. Samples of the subsurface materials encountered were
obtained using split barrel and California barrel sampling procedures in general accordance with
ASTM Specifications D1586 and D3550, respectively. In the split barrel and California barrel
sampling procedures, standard sampling spoons are driven into the ground by means of a 140-pound
hammer falling a distance of 30 inches. The number of blows required to advance the split barrel
and California barrel samplers is recorded and is used to estimate the in-situ relative density of
cohesionless materials and, to a lesser degree of accuracy, the consistency of cohesive soils and
hardness of weathered bedrock. All samples obtained in the field were sealed and returned to our
laboratory for further examination, classification, and testing.
Moisture content tests were completed on each of the recovered samples. The unconfined strength
of appropriate samples was estimated using a calibrated hand penetrometer. Dry unit weights were
determined on selected samples, and the quantity and plasticity of fines in subgrade materials were
tested with washed sieve analysis and Atterberg limits, respectively. Swell/consolidation tests were
completed on select samples to evaluate the soils’ tendency to change volume with variation in
moisture content at their current moisture and density conditions.
As part of the testing program, all samples were examined in the laboratory by an engineer and
classified in accordance with the attached General Notes and the Unified Soil Classification System,
based on the 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. Classification of the bedrock was based on visual and tactual
observation of disturbed samples and auger cuttings. Coring and/or petrographic analysis may
reveal other rock types.
SITE AND SUBSURFACE CONDITIONS
The proposed redevelopment site is located at the southwest corner of West Elizabeth Street and
City Park Avenue in Fort Collins, Colorado. The existing building which has housed Consuelo’s
Mexican Restaurant is located on the site. The remainder of the site is generally covered with paved
drive and parking. The existing structure will be razed as part of the redevelopment. At this time, it
is unknown whether the existing parking will be incorporated into the new pavements or removed
and replaced.
Earth Engineering Consultants, Inc.
EEC Project No. 1122010
February 7, 2012
Page 3
Based on results of the field borings and laboratory testing, subsurface conditions at the boring
locations can be generalized as follows. Approximately 3 to 4½ inches of hot bituminous pavement
(HBP) overlying 4½ to 6 inches of aggregate base course was encountered at the boring locations.
The described pavement sections were underlain by silty/sandy lean clay, generally colored brown
and rust. The cohesive soils extended to a depth of approximately 6 feet and were underlain by
brown sands and gravels. The granular soils extended to a depth of approximately 10 feet and were
underlain by claystone/siltstone/sandstone bedrock.
The sandy lean clay soils were stiff in consistency and showed low potential to change volume with
variation in moisture content and load at their present moisture and density conditions. The
underlying sands and gravels were generally medium dense and were poorly graded. The
siltstone/claystone bedrock was highly weathered near surface; however, became less weathered and
more competent with depth. The bedrock was generally moderately hard to hard.
The stratification boundaries indicated on the boring logs represent the approximate locations of
changes in soil and rock types; in-situ, the transition of materials may be gradual and indistinct.
Groundwater Conditions
Observations were made while drilling and after completion of the borings to detect the presence and
depth to hydrostatic groundwater. Free water was observed at depths of approximately 7½ to 8½
feet below existing ground surface at the time of drilling. The bore holes were backfilled upon
completion; longer term observations of groundwater levels were not obtained.
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. Monitoring of groundwater
levels in cased holes which are sealed from the influence of surface water would be necessary to
more accurately evaluate groundwater levels and fluctuations in those levels over time.
Zones of perched and/or trapped water can be encountered in more permeable zones within subgrade
soils at varying times throughout the year. Perched water is commonly encountered in granular
seams in the soils or in soils immediately overlying less permeable weathered bedrock. Variations
in the locations and depth to perched water can also occur over time depending on variations in
hydrologic conditions and other conditions not apparent at the time of this report.
Earth Engineering Consultants, Inc.
EEC Project No. 1122010
February 7, 2012
Page 4
ANALYSIS AND RECOMMENDATIONS
Site Preparation
We understand the existing structure on the site will be razed prior to the proposed redevelopment.
Demolition of the existing structure should include removal of all floor slabs, foundations, and other
improvements including fill and backfill soils over and adjacent to those improvements. Any
existing pavements or exterior slabs should also be removed from with the new building area and
any other structural improvement areas.
Fill materials required to develop the foundation and floor slab subgrades should consist of
approved, low volume change soils which are free from organic matter and debris. Those soils could
be similar to the site sandy lean clay materials or could consist of a more granular import structural
fill with sufficient fines to prevent ponding of water in the fill areas. Fill soils in the footing and
floor slab areas should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture
content and compacted to at least 95% of the materials maximum dry density as determined in
accordance with ASTM Specification D698, the standard Proctor procedure. The moisture content
of the placed fill materials should be adjusted to be within ±2% of standard Proctor optimum
moisture content at the time of placement.
Care should be taken prior to placement of overlying improvements to prevent wetting and drying or
disturbance of the subgrade materials. Subgrade materials which are allowed to become wet and
soft or dry and desiccated or materials which are disturbed by the construction activities would
require removal and replacement or reworking in-place prior to placement of overlying structures or
other site improvements.
Foundations
Based on materials observed at the test boring locations, we anticipate the proposed structure could
be supported on conventional footing foundations. Those footing foundations would bear in the
natural site sandy lean clay soils or newly placed and compacted fill materials. We expect bearing
pressures in the range of 1,500 to 2,000 psf could be used for design of footing foundations bearing
on those materials. As an alternate, more heavily loaded foundations could be supported on drilled
Earth Engineering Consultants, Inc.
EEC Project No. 1122010
February 7, 2012
Page 5
piers extending to the underlying claystone/siltstone bedrock. Drilled piers could be designed using
significantly higher allowable bearing pressure which would be suitable for higher concentrated
loads. However, the presence of a relatively shallow groundwater table and granular subgrade
material would suggest that temporary casing would be required to maintain open boreholes for
construction of the drilled pier foundations.
Backfill placed adjacent to foundation footings or stem walls should be placed and compacted as
outlined for site preparation fill materials.
Alternative foundation types could be considered including post-tension slab-on-grade foundations.
Specific recommendations for alternate foundation types could be provided at time of the final
geotechnical exploration for the site, if appropriate.
Floor Slab Subgrades
The in-situ site subgrade materials showed low potential for swelling or consolidation at existing
moisture and density in laboratory testing. Based on the relatively low swell potential, we anticipate
floor slabs could be supported directly on the natural site subgrade soils or on newly placed and
compacted structural fill within the area of the existing structure. Fill materials for support of the
floor slabs should be placed as outlined for fill materials in the site preparation.
Care should be taken to avoid disturbing the subgrade materials prior to placement of floor slabs.
Floor slab subgrade materials which are disturbed by construction activities or soils which become
wet and softened or dry and desiccated should be removed and replaced or reworked in-place prior
to construction of the overlying floor slab.
Care should also be taken during construction to avoid densification of the subgrades prior to
placement of the overlying floor slabs. Densification can occur with repeated passes of heavily
loaded construction equipment across the prepared subgrades.
Earth Engineering Consultants, Inc.
EEC Project No. 1122010
February 7, 2012
Page 6
Pavements
At the time of this report, it was not known if existing pavements would remain in-place and
incorporated into the new paved drive and parking areas or if all pavements would be removed from
site and the pavement areas reconstructed. Specific recommendations regarding those options can
be provided when the design approach is known.
In general, the site subgrade soils show low potential for swelling at current moisture and density
conditions indicating those materials could be used for direct support of pavements. Existing trees
are located within the south portion of the property which may include dry and desiccated clay soils
in the area of the root structure. Those dry and desiccated soils should be removed from the
pavement areas if the associated trees will be removed.
Upon removal of the existing pavements in clay subgrade soils, it is common to see instability in the
pavement subgrades. Instability of the pavement subgrades is commonly seen with pumping and
possibly rutting of the pavement subgrades with wet cohesive subgrades. We suggest stabilization
of subgrades with the addition of Class C fly ash should be anticipated if the existing pavements are
removed and reconstructed. If those pavements remain in-place, subgrade instability may not be a
consideration; however, joints, cracks and unstable areas in the existing pavements should be
anticipated to reflect through the new pavement overlay.
For reconstruction of pavements, we expect minimum pavement sections in the range of 3 to 4
inches of hot bituminous pavement (HBP) overlying 4 to 6 inches of aggregate base course on a
stabilized subgrade would be required to develop suitable pavement section for automobiles and
light trucks. Areas of heavier truck traffic including both higher volumes and heavier vehicles may
require additional pavement thickness.
GENERAL COMMENTS
The analysis and recommendations presented in this report are based upon the data obtained from
the soil borings performed at the indicated locations and from any other information discussed in this
report. This report does not reflect any variations, which may occur between borings or across the
Earth Engineering Consultants, Inc.
EEC Project No. 1122010
February 7, 2012
Page 7
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 Elizabeth & City Park Corner, LLC 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:
1401 W. ELIZABETH STREET
FORT COLLINS, COLORADO
EEC PROJECT NO. 1122010
JANUARY 2012
DATE:
RIG TYPE: CME45
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: MANUAL
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
ASPHALT - 3" _ _
BASE - 4.5" 1
_ _
SILTY SANDY LEAN CLAY (CL) 2
brown / rust _ _
stiff 3
_ _
4
_ _
CS 5 6 4000 14.5 102.9 36 20 49.7 <500 psf None
_ _
6
_ _
SAND & GRAVEL (SP-GP) 7
medium dense _ _
8
_ _
9
_ _
CS 10 14 -- 12.7 129.8 NL NP 13.6
_ _
CLAYSTONE / SILTSTONE / SANDSTONE 11
brown / olive / rust _ _
highly weathered 12
_ _
13
_ _
14
_ _
CS 15 --
BOTTOM OF BORING DEPTH 15.0' _ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants
A-LIMITS SWELL
DATE:
RIG TYPE: CME45
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: MANUAL
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
ASPHALT - 4.5" _ _
ABC - 6" 1
_ _
LEAN CLAY with SAND (CL) 2
brown _ _ % @ 150 psf
stiff CS 3 10 3500 19.4 103.9 43 29 76.2 600 psf 1.1%
_ _
4
_ _
CS 5 10 2500 20.4 105.3 40 26 78.5 <500 psf None
_ _
6
_ _
SAND & GRAVEL (SP-GP) 7
medium dense _ _
8
_ _
9
_ _
SS 10 11 2500 25.2
_ _
CLAYSTONE / SILTSTONE 11
brown / rust / olive _ _
highly weathered 12
_ _
13
_ _
14
_ _
CS 15 --
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CLAYSTONE / SILTSTONE / SANDSTONE CS 20 50/6" 9000+ 10.2 128.1
brown / rust / olive _ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 50/3.5" 9000+ 10.2
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants
A-LIMITS SWELL
SWELL / CONSOLIDATION TEST RESULTS
% Swell @ 500:
Project:
Project #:
Date:
1122010
February 2012
Swell Pressure: <500 psf
1401 W. Elizabeth Street
Fort Collins, Colorado
None
Beginning Moisture: 14.5% Dry Density: 111.1 pcf Ending Moisture: 15.7%
Material Description:
Sample Location:
Liquid Limit: 36 Plasticity Index: 20
Brown / Rust Sandy Lean Clay (CL)
Boring 1, Sample 1, Depth 4'
% Passing #200: 49.7%
-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)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
% Swell @ 150:
Project:
Project #:
Date:
Material Description: Brown Sandy Lean Clay (CL)
Sample Location: Boring 2, Sample 1, Depth 2'
Liquid Limit: 43 Plasticity Index: 29 % Passing #200: 76.2%
Beginning Moisture: 19.4% Dry Density: 106.6 pcf Ending Moisture: 20.8%
Swell Pressure: 600 psf 1.1%
1401 W. Elizabeth Street
Fort Collins, Colorado
1122010
February 2012
-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)
Water Added
Consolidation Swell
SWELL / CONSOLIDATION TEST RESULTS
% Swell @ 500:
Project:
Project #:
Date:
Material Description: Brown Lean Clay with Sand (CL)
Sample Location: Boring 2, Sample 2, Depth 4'
Liquid Limit: 40 Plasticity Index: 26 % Passing #200: 78.5%
Beginning Moisture: 20.4% Dry Density: 103.9 pcf Ending Moisture: 22.1%
Swell Pressure: <500 psf None
1401 W. Elizabeth Street
Fort Collins, Colorado
1122010
February 2012
-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)
Water Added
Consolidation Swell
2 1/2" (63 mm)
2" (50 mm)
1 1/2" (37.5 mm)
1" (25 mm)
3/4" (19 mm)
1/2" (12.5 mm)
3/8" (9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 16 (1.18 mm)
No. 30 (600 m)
No. 40 (425 m)
No. 50 (300 m)
No. 100 (150 m)
No. 200 (75 m)
Project: 1401 W. Elizabeth Street
Location: Fort Collins, Colorado
Project No: 1122010
Sample Desc.: B-1, S-2, at 9'
Date: February 2012
100
83
NL
78
66
54
42
19
13.6
31
24
Plasticity Index
Plastic Limit NP
NP
EARTH ENGINEERING CONSULTANTS, INC.
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
SUMMARY OF LABORATORY TEST RESULTS
100
27
100
91
Sieve Size
Liquid Limit, Plastic Limit and Plasticity Index of Soils (AASHTO T 89 & T90/ASTM D 4318)
Liquid Limit
Percent Passing
100
Project: 1401 W. Elizabeth Street
Project Number:
Sample Desc.: B-1, S-2, at 9'
Date: February 2012
Summary of Washed Sieve Analysis Tests (ASTM C117 & C136)
Coarse Fine
EARTH ENGINEERING CONSULTANTS, INC.
1122010
Coarse Medium
Cobble
Fine
Sand Silt or Clay
Gravel
Location: Fort Collins, Colorado
0
10
20
30
40
50
60
70
80
90
100
1000 100 10 1 0.1 0.01
Finer by Weight (%)
Grain Size (mm)
5" 3" 1" 1/2" No. 4 No. 16 No. 40 No. 100
6" 4" 2" 3/4" 3/8" No. 8 No. 30 No. 50 No. 200
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 2/1/2012 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 2/1/2012 WHILE DRILLING 8.5'
LOG OF BORING B-2
1401 W. ELIZABETH STREET
FORT COLLINS, COLORADO
PROJECT NO: 1122010 FEBRUARY 2012
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 2/1/2012 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 2/1/2012 WHILE DRILLING 7.5'
LOG OF BORING B-1
1401 W. ELIZABETH STREET
FORT COLLINS, COLORADO
PROJECT NO: 1122010 FEBRUARY 2012
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