HomeMy WebLinkAboutMAX FLATS - PDP - PDP120034 - SUBMITTAL DOCUMENTS - ROUND 1 - RECOMMENDATION/REPORTGEOTECHNICAL SUBSURFACE EXPLORATION REPORT
PROPOSED 5-STORY MIXED USE BUILDING
203 WEST MUBERRY STREET
FORT COLLINS, COLORADO
EEC PROJECT NO. 1122094
Prepared for:
Brinkman Partners
3003 East Harmony Road, Suite 300
Fort Collins, Colorado 80528
Attn: Ms. Tina Hippeli (tina.hippeli@brinkmanpartners.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
December 3, 2012
Brinkman Partners
3003 East Harmony Road, Suite 300
Fort Collins, Colorado 80528
Attn: Ms. Tina Hippeli (tina.hippeli@brinkmanpartners.com)
Re: Geotechnical Subsurface Exploration Report
Proposed 5-Story Mixed Use Building
203 West Mulberry Street
Fort Collins, Colorado
EEC Project No. 1122094
Ms. Hippeli:
Enclosed, herewith, are the results of the geotechnical subsurface exploration completed by
Earth Engineering Consultants, Inc. (EEC) for the referenced project. For this exploration,
four (4) soil borings were drilled on November 5, 2012 at select locations within the
footprint of the proposed mixed use building at 203 West Mulberry Street in Fort Collins,
Colorado. To accommodate the proposed 5-story mixed-use development project, the
existing King’s Auto building and associated site work, currently occupying the property,
will be demolished. The borings were extended to approximate depths of 35 to 45 feet
below present site grades. This study was completed in general accordance with our
proposal dated October 8, 2012.
In summary, the subsurface soils encountered beneath the surficial landscape/pavements,
generally consisted of cohesive lean clay with sand and sandy lean clay layers, which
extended to a fine to coarse granular strata below. Sand with gravel, varying fines and
intermittent cobbles was encountered beneath the upper cohesive soils at depths of
approximately 19 to 20 feet below existing site grades and extended to the bedrock below.
Sandstone bedrock was encountered in each of the borings beneath the overburden soils at
depths of approximately 25 to 29 feet below existing site grades and extended to the depths
explored, approximately 35 to 45 feet. Groundwater was encountered across the site
during the field exploration at approximate depths of 20 to 21 feet below existing site
grades.
GEOTECHNICAL SUBSURFACE EXPLORATION REPORT
PROPOSED 5-STORY MIXED USE BUILDING
203 WEST MULBERRY STREET
FORT COLLINS, COLORADO
EEC PROJECT NO. 1122094
December 3, 2012
INTRODUCTION
The geotechnical subsurface exploration for the proposed 5-story mixed use building to be
constructed at 203 West Mulberry Street in Fort Collins, Colorado, has been completed. For this
exploration, four (4) soil borings extending to depths of approximately 35 to 45 feet below
present site grades were drilled on November 5, 2012 at pre-selected locations within the new
building footprint. This exploration was completed in general accordance with our proposal
dated October 8, 2012.
We understand the new building will have a total floor area on the order of 45,000 to 50,000
square feet of residential apartments in four (4) stories over tuck-under at-grade parking.
Approximately 1,500 sf of commercial flex space will also be constructed at grade level.
Existing buildings on a portion of the site will be demolished prior to construction of the new
structure. Foundation loads for the new structure are estimated to be moderate with maximum
column loads likely in the range of 400 kips. Floor loads are expected to be light. Small grade
changes are expected to develop final site grades for the grade level improvements.
The purpose of this report is to describe the subsurface conditions encountered in the test borings,
analyze and evaluate the test data and provide geotechnical recommendations concerning design
and construction of foundations and support of at grade pavements, floor slabs and flatwork for
the new building.
EXPLORATION AND TESTING PROCEDURES
The boring locations were established in the field by representatives from Earth Engineering
Consultants, Inc. (EEC) by pacing and estimating angles from identifiable site features. Those
approximate boring locations are indicated on the attached boring location diagram. The
locations of the borings should be considered accurate only to the degree implied by the methods
used to make the field measurements. Photographs of the site taken at the time of drilling are
included with this report.
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
Page 2
The test borings were completed using a truck mounted, CME-55 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 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 soils and, to a lesser degree of accuracy,
the consistency of cohesive soils and hardness of weathered bedrock. In the California barrel
sampling procedure, relatively undisturbed samples are obtained in removable brass liners. All
samples obtained in the field were sealed and returned to the laboratory for further examination,
classification, and testing.
Laboratory moisture content tests were completed on each of the recovered samples. Washed
sieve analysis and Atterberg limits tests were completed on selected samples to evaluate the
quantity and plasticity of fines in the subgrade samples. Swell/consolidation tests were
completed on selected samples to evaluate the potential for the subgrade materials to change
volume with variation in moisture and load. Soluble sulfate tests were completed on selected
samples to evaluate potential for sulfate attack on site-cast concrete. Results of the outlined tests
are indicated on the attached boring logs and summary sheets.
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 soil’s 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.
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
Page 3
SITE AND SUBSURFACE CONDITIONS
The area for the proposed building currently includes an existing building, a parking/drive area
and areas which are currently landscaped with grass and deciduous trees. The site is relatively
flat.
Based on results of the field borings and laboratory testing, subsurface conditions can be
generalized as follows. The subsurface soils encountered beneath the surficial topsoil/landscaped
zone or pavements, generally consisted of cohesive lean clay with sand and sandy lean clay layers
which extended to a fine to coarse granular strata below. The cohesive soils were soft to medium
stiff to stiff, and exhibited generally low expansive characteristics with slight
compressible/consolidation characteristics.
Intermittent sand and gravel lenses were encountered at increased depths within the cohesive
zone. Sand with gravel and varying fines and intermittent cobbles was encountered beneath the
upper cohesive soils at depths of approximately 19 to 20 feet below existing site grades and
extended to the bedrock below. The granular materials were medium dense to dense.
Sandstone bedrock with was encountered in each of the borings beneath the overburden soils at
depths of approximately 25 to 29 feet below existing site grades and extended to the depths
explored, approximately 35 to 45 feet. The bedrock formation was weathered nearer surface;
however, became less weathered and more competent with depth, exhibiting moderate to high
load bearing capabilities.
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. At the time of drilling, free water was observed within the
test borings at approximate depths of 20 to 21 feet below existing site grades. The borings were
backfilled with auger cuttings upon completion of our drilling operations; subsequent
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
Page 4
groundwater measurements were not obtained. The observed groundwater depths are consistent
with groundwater depths previously observed in other explorations we have completed in the
general area.
Fluctuations in groundwater levels can occur over time depending on variations in hydrologic
conditions, irrigation demands on and/or adjacent to the site and other conditions not apparent at the
time of this report. Longer term monitoring of water levels in cased wells, which are sealed from
the influence of surface water would be required to more accurately evaluate fluctuations in
groundwater levels at the site. We have typically noted deepest groundwater levels in late winter
and shallowest groundwater levels in mid to late summer. Zones of perched and/or trapped water
can be encountered at times throughout the year in more permeable zones in the subgrade soils and
perched water is commonly observed in subgrade soils immediately above lower permeability
bedrock.
ANALYSIS AND RECOMMENDATIONS
Swell/Consolidation Test Results
Swell/consolidation testing is performed to evaluate the swell or collapse potential of soils or
bedrock for determining foundation, floor slab and pavement design criteria. In this test, relatively
undisturbed samples obtained directly from the California barrel sampler are placed in a laboratory
apparatus and inundated with water under a predetermined load. All samples are monitored for
swell and consolidation. 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. After the inundation
period, additional incremental loads are applied to evaluate the swell pressure and/or consolidation.
For this assessment, we conducted three (3) swell-consolidation tests at various intervals/depths
throughout the site. The swell tests completed on the cohesive overburden soils revealed low
expansive characteristics. Results of the swell tests are indicated on the attached boring logs and
summary sheets.
Colorado Association of Geotechnical Engineers (CAGE) uses the following information to provide
uniformity in terminology between geotechnical engineers to provide a relative correlation of
performance risk to measured swell. “The representative percent swell values are not necessarily
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
Page 5
measured values; rather, they are a judgment of the swell of the soil and/or bedrock profile likely to
influence slab performance.” Geotechnical engineers use this information to also evaluate the swell
potential risks for foundation performance based on the risk categories.
Recommended Representative Swell Potential Descriptions and Corresponding
Slab Performance Risk Categories
Slab Performance Risk Category Representative Percent Swell
(500 psf Surcharge)
Representative Percent Swell
(1000 psf Surcharge)
Low 0 to < 3 0 < 2
Moderate 3 to < 5 2 to < 4
High 5 to < 8 4 to < 6
Very High > 8 > 6
Based on the laboratory test results, the overburden cohesive soils were within the low range
while the underlying granular soils and sandstone bedrock would have no to very low swell
potential. Variations may exist across the site.
General Considerations and Discussion of Native Overburden Soils
The subject site is generally overlain by approximately 20 feet of cohesive clay soils which
extend to fine to coarse granular soils below. The cohesive subsoils have a tendency to
consolidate when inundated with water and subjected to increased loads. These soils would also
show instability and strength loss when wetted and/or subjected to construction traffic loads.
Final grading plans were not provided prior to the preparation of this subsurface exploration report.
Based on information provided, we estimate small cuts and fills may be necessary to achieve final
grades.
The recommendations contained in this report assume that small amounts of fill will be required,
and will be placed according to the recommendations provided herein. If there are any significant
deviations from the assumptions concerning fill depth and/or placement when the final site plan is
developed, the conclusions and recommendations of this report should be reviewed and
confirmed/modified as necessary to reflect the final planned site configuration.
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
Page 6
Site Preparation
All existing vegetation, tree root growth from the existing deciduous trees within the site
improvement areas, topsoil, pavements and any uncontrolled fill material that may be
encountered during the excavation phases, should be removed from improvement and/or fill areas
on the site. Demolition of the existing structures, concrete sidewalks, and other miscellaneous
features should include complete removal of all concrete or debris within the proposed
construction area. Site preparation should include removal of any loose backfill found adjacent
to the existing site structures/improvements. All materials derived from the demolition of the
existing building, pavements, sidewalks or other site improvements should be removed from the
site and not be allowed for use in any on-site fills.
Although final site grades were not available at the time of this report, based on our
understanding of the proposed development, we expect small fill depths may be necessary to
achieve design grades in the improvement areas. After stripping, completing all cuts, and
removing all unacceptable materials/soils, and prior to placement of any fill or site
improvements, we recommend the exposed soils be scarified to a minimum depth of 9-inches,
adjusted in moisture content to within ±2% of standard Proctor optimum moisture content and
compacted to at least 95% of the material's standard Proctor maximum dry density as determined
in accordance with ASTM Specification D698.
Fill soils required for developing the building and site subgrades, after the initial zone has been
prepared or stabilized where necessary, should consist of approved, low-volume-change
materials, which are free from organic matter and debris. It is our opinion the on-site cohesive
clay soils could be used as general site fill material, provided adequate moisture treatment and
compaction procedures are followed.
We recommend all fill materials and foundation wall backfill materials, be placed in loose lifts
not to exceed 9 inches thick and adjusted in moisture content, +/- 2% for cohesive soils and +/-
3% for cohesionless soils of optimum 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.
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
Page 7
If the site’s slightly cohesive soils are used as fill material, care will be needed to maintain the
recommended moisture content prior to and during construction of overlying improvements.
Care will also be needed to avoid over compaction of the cohesive soils which can occur in site
construction traffic routes.
Care should be exercised after preparation of the subgrades to avoid disturbing the subgrade
materials. Positive drainage should be developed away from the structure to avoid wetting of
subgrade materials. Subgrade materials becoming wet subsequent to construction of the site
structure can result in unacceptable performance.
Drilled Piers/Caissons Foundations
Based on the subgrade conditions observed in the test borings and on the anticipated foundation
loads, we recommend support the proposed building on a grade beam and straight shaft drilled
pier/caisson foundation system extending into the underlying bedrock formation. Particular
attention will be required in the construction of drilled piers due to the depth of bedrock and
presence of groundwater.
For axial compression loads, the drilled piers could be designed using a maximum end bearing
pressure of 35,000 pounds per square foot (psf), along with a skin-friction of 3,500 psf for the
portion of the pier extended into the underlying firm and/or harder bedrock formation. Straight
shaft piers should be drilled a minimum of 10-feet into competent or harder bedrock. Lower values
may be appropriate for pier “groupings” depending on the pier diameters and spacing. Pile groups
should be evaluated individually.
To satisfy forces in the horizontal direction, piers may be designed for lateral loads using a modulus
of 50 tons per cubic foot (tcf) for the portion of the pier in native cohesive soils, 75 tcf for native
granular materials or engineered fill, and 400 tcf in bedrock for a pier diameter of 12 inches. The
coefficient of subgrade reaction for varying pier diameters is as follows:
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
Page 8
Pier Diameter (inches)
Coefficient of Subgrade Reaction (tons/ft3)
Cohesive Soils
Engineered Fill or
Granular Soils
Bedrock
18 33 50 267
24 25 38 200
30 20 30 160
36 17 25 133
When the lateral capacity of drilled piers is evaluated by the L-Pile (COM 624) computer program,
we recommend that internally generated load-deformation (P-Y) curves be used. The following
parameters may be used for the design of laterally loaded piers, using the L-Pile (COM 624)
computer program:
Parameters Native Granular Soils or
Structural Fill
On-Site Overburden
Cohesive Soils Bedrock
Unit Weight of Soil (pcf) 130
(1)
115
(1)
125
(1)
Cohesion (psf) 0 200 5000
Angle of Internal Friction (degrees) 35 25 20
Strain Corresponding to ½ Max. Principal
Stress Difference 50
--- 0.02 0.015
*Notes: 1) Reduce by 64 PCF below the water table
Drilling caissons to design depth should be possible with conventional heavy-duty single flight
power augers equipped with rock teeth on the majority of the site. However, areas of well-
cemented sandstone bedrock lenses may be encountered throughout the site at various depths where
specialized drilling equipment and/or rock excavating equipment may be required. Varying zones
of cobbles may also be encountered in the granular soils above the bedrock. Excavation penetrating
the well-cemented sandstone bedrock may require the use of specialized heavy-duty equipment,
together with rock augers and/or core barrels. Consideration should be given to obtaining a unit
price for difficult caisson excavation in the contract documents for the project.
Due to the presence of granular soils and groundwater at approximate depths of 20 feet below site
grades, maintaining shafts may be difficult without stabilizing measures. Groundwater was
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
Page 9
encountered at approximate depths of 20 to 21 feet below site grades; we expect temporary
casing will be required to adequately/properly drill and clean piers prior to concrete placement.
Difficulty can be encountered in “sealing” temporary casing into the surface of the sandstone
bedrock. Groundwater should be removed from each pier hole prior to concrete placement. Pier
concrete should be placed immediately after completion of drilling and cleaning.
A maximum 3-inch depth of groundwater is acceptable in each pier prior to concrete placement. If
pier concrete cannot be placed in dry conditions, a tremie should be used for concrete placement.
Due to potential sloughing and raveling, foundation concrete quantities may exceed calculated
geometric volumes. Pier concrete with slump in the range of 6 to 8 inches is recommended. Casing
used for pier construction should be withdrawn in a slow continuous manner maintaining a
sufficient head of concrete to prevent infiltration of water or the creation of voids in pier concrete.
Foundation excavations should be observed by the geotechnical engineer. A representative of the
geotechnical engineer should inspect the bearing surface and pier configuration. If the soil
conditions encountered differ from those presented in this report, supplemental recommendations
may be required.
We estimate the long-term settlement of drilled pier foundations designed and constructed as
outlined above would be less than 1-inch.
Seismic
The site soil conditions consist of approximately 25 to 29 feet of overburden soils overlying
moderately hard bedrock. For those site conditions, the 2009 International Building Code
indicates a Seismic Site Classification of D.
Floor Slab/Pavement Subgrade
The near surface subgrades in the area of the floor slabs and pavements consist of stiff to very
stiff sandy lean clays. The floor and flatwork subgrades should be prepared as outlined under
Site Preparation as previously provided in this report. The in-situ cohesive soils have low swell
potential; however, some movement can still occur in the cohesive soil subgrades. Near surface
soils which become dry and desiccated or densified with site construction traffic can increase
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
Page 10
potential for post-construction heaving. Care should be taken immediately prior to placement of
pavements, floor slabs and flatwork to verify that the near surface subgrades are not subject to
higher swell potential prior to placement of the overlying improvements.
Cohesive soils can be subject to instability and strength loss when wetted. If the subgrades show
high instability and pumping at the time of floor slab or pavement placement, stabilization of
those subgrades may be needed prior to placement of the overlying improvements. Use of a
granular structural fill to develop site grades could reduce potential for instability.
Pavements
We anticipate the site pavements will be constructed of Portland cement concrete supported on
acceptable sandy lean clay subgrade soils. We also expect the pavement areas will be subject to
low volumes of automobile and light truck traffic.
For the outlined conditions, we recommend the Portland cement concrete pavement section be
constructed with at least 5 inches of Portland cement concrete consisting of an exterior concrete
pavement mix with a minimum 28-day compressive strength of 4,200 psi. The concrete
pavement should be air entrained and use of woven wire mesh or fiber mesh should be considered
to control shrinkage cracking.
Pavement design methods are intended to provide structural sections with sufficient thickness on
particular subgrades such as wheel loads are reduced to a level the subgrade can support. Support
characteristics of the subgrade for pavement design do not account for shrink/swell movements of
an expansive clay subgrade or consolidation of a wetted subgrade. Thus, the pavement maybe
adequate from a structural standpoint yet still experience cracking and deformation due to
shrink/swell related movements of the subgrade. It is important to minimize moisture changes in
the subgrades to reduce the post-construction shrink/swell movement.
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
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Soil Corrosivity
The results of the soluble sulfate tests indicate low potential for sulfate attack on Portland cement
concrete. ASTM Type I Portland cement can be used for concrete mixes on and below site grade
within the overburden soils. However, if there is no, or minimal cost differential, use of ASTM
Type I/II Portland cement is recommended for additional sulfate resistance of the concrete.
Foundation concrete should be designed in accordance with the provisions of the ACI Design
Manual, Section 318, Chapter 4.
Other Considerations
Excavations into the on-site soils may encounter a variety of conditions. Shallow excavations
into the on-site clays can be expected to stand on relatively steep temporary slopes during
construction. Individual contractor(s) should be made responsible for designing and constructing
stable, temporary excavations as required to maintain stability of both the excavation sides and
bottom. All excavations should be sloped or shored in the interest of safety following local and
federal regulations, including current OSHA excavation and trench safety standards.
GENERAL COMMENTS
The analysis and recommendations presented in this report are based upon the data obtained from
the soil borings performed at the indicated locations and from any other information discussed in
this report. This report does not reflect any variations, which may occur between borings or
across the site. The nature and extent of such variations may not become evident until
construction. If variations appear evident, it will be necessary to re-evaluate the
recommendations of this report.
It is recommended that the geotechnical engineer be retained to review the plans and
specifications so comments can be made regarding the interpretation and implementation of our
geotechnical recommendations in the design and specifications. It is further recommended that
the geotechnical engineer be retained for testing and observations during earthwork phases to
help determine that the design requirements are fulfilled. Site-specific explorations should be
completed to develop site-specific recommendations for each of the site buildings.
Earth Engineering Consultants, Inc.
EEC Project No. 1122094
December 3, 2012
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This report has been prepared for the exclusive use for Brinkman Partners, 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:
203 W. MULBERRY
FORT COLLINS, COLORADO
EEC PROJECT NO. 1122094
NOVEMBER 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 3.5" _ _
BASE 3" 1
_ _
SANDY LEAN CLAY (CL) / CLAYEY SAND (SC) 2
brown _ _
stiff to very stiff 3
_ _
4
_ _
CS 5 14 9000+ 12.4 105.8 35 16 43.7 2500 psf 1.2%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
brown / red / tan SS 10 12 9000 16.7
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 23 9000+ 16.3 113.3
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 11 6000 16.7
_ _
21
_ _
SAND & GRAVEL (SP/GP) 22
dense _ _
23
_ _
24
_ _
SS 25 30 -- 9.7
Continued on Sheet 2 of 2 _ _
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
Continued from Sheet 1 of 2 26
_ _
SAND & GRAVEL (SP/GP) 27
_ _
28
_ _
29
_ _
SANDSTONE SS 30 50/5" -- 11.5
brown / grey / rust _ _
31
_ _
32
_ _
33
_ _
34
_ _
CS 35 --
_ _
36
_ _
37
_ _
38
_ _
39
brown / grey _ _
SS 40 -- -- 19.1
_ _
BOTTOM OF BORING DEPTH 40.5' 41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants
24 HOUR N/A
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 3" _ _
BASE 3" 1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff 3
_ _
4
_ _
CS 5 5 -- 18.9 105.5
_ _
6
_ _
7
_ _
8
_ _
9
_ _
brown / tan SS 10 7 -- 26.0
_ _
11
_ _
12
_ _
13
_ _
14
_ _ % @ 1000 psf
* classified as LEAN CLAY (CL) CS 15 10 5000 17.5 114.7 28 9 85.7 <500 psf None
brown / red / tan _ _
with traces of gravel 16
_ _
17
_ _
18
_ _
19
_ _
SS 20 14 5000 24.0
_ _
21
SAND & GRAVEL (SP/GP) _ _
brown / rust / grey 22
dense _ _
23
_ _
24
_ _
SS 25 33 -- 8.3
Continued on Sheet 2 of 2 _ _
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
Continued from Sheet 1 of 2 26
_ _
SANDSTONE 27
brown / grey / rust _ _
28
_ _
29
_ _
CS 30 50/3" -- 17.6
_ _
31
_ _
32
_ _
33
_ _
34
_ _
SS 35 50/3" -- 18.9
_ _
36
_ _
37
_ _
38
_ _
39
_ _
SS 40 50/3" -- 18.6
_ _
41
_ _
42
_ _
43
_ _
44
_ _
SS 45 50/1"
_ _
BOTTOM OF BORING DEPTH 45.5' 46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants
24 HOUR N/A
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 2.5-3" _ _
BASE 3" 1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
stiff to very stiff 3
with calcareous deposits _ _
4
_ _
CS 5 8 9000 8.3 102.5 3000 psf 1.5%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 10 9000 17.2
_ _
11
_ _
12
_ _
13
_ _
14
_ _
with traces of gravel CS 15 30 9000 9.7 131.0
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SAND & GRAVEL (SP/GP) SS 20 50 -- 2.4
very dense _ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 48 -- 13.8
Continued on Sheet 2 of 2 _ _
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
Continued from Sheet 1 of 2 26
SAND & GRAVEL (SP/GP) _ _
27
_ _
SANDSTONE 28
brown / rust _ _
29
_ _
SS 30 50/6" -- 21.4
_ _
31
_ _
32
_ _
33
_ _
34
_ _
CS 35 50/2" -- 17.4
BOTTOM OF BORING DEPTH 35.0' _ _
36
_ _
37
_ _
38
_ _
39
_ _
40
_ _
41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants
24 HOUR N/A
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 3" _ _
BASE 3" 1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
stiff to very stiff 3
_ _
4
_ _
CS 5 9 -- 1.1
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 10 9000+ 16.3
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 8 9000+ 10.6 119.0
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SAND & GRAVEL (SP/GP) SS 20 4 4000 26.6
loose to dense _ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 36 -- 22.1
Continued on Sheet 2 of 2 _ _
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
Continued from Sheet 1 of 2 26
_ _
SANDSTONE 27
brown / grey/ rust _ _
28
_ _
29
_ _
CS 30 50/4.5" 7000 16.1 110.3
_ _
31
_ _
32
_ _
33
_ _
34
_ _
SS 35 50/4" -- 19.8 NL NP 85.6
grey _ _
36
_ _
37
_ _
38
_ _
39
_ _
CS 40 50/3" 9000+ 122.3
BOTTOM OF BORING DEPTH 40.0' _ _
41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants
24 HOUR N/A
A-LIMITS SWELL
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL) / Clayey Sand (SC)
Sample Location: Boring 1, Sample 1, Depth 4'
Liquid Limit: 35 Plasticity Index: 16 % Passing #200: 43.7%
Beginning Moisture: 12.4% Dry Density: 121.9 pcf Ending Moisture: 17.3%
Swell Pressure: 2500 psf % Swell @ 500: 1.2%
203 W Mulberry St
Fort Collins, Colorado
1122094
November 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)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Red / Tan LEAN CLAY (CL)
Sample Location: Boring 2, Sample 3, Depth 14'
Liquid Limit: 28 Plasticity Index: 9 % Passing #200: 85.7%
Beginning Moisture: 17.5% Dry Density: 112.9 pcf Ending Moisture: 18.7%
Swell Pressure: <500 psf % Swell @ 1000: None
203 W Mulberry St
Fort Collins, Colorado
1122094
November 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)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
Sample Location: Boring 3, Sample 1, Depth 4'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
Beginning Moisture: 8.3% Dry Density: 106.8 pcf Ending Moisture: 21.9%
Swell Pressure: 3000 psf % Swell @ 500: 1.5%
203 W Mulberry St
Fort Collins, Colorado
1122094
November 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)
Consolidatio Swell
Water Added
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: 203 W Mulberry St
Location: Fort Collins, Colorado
Project No: 1122094
Sample Desc.: Boring B-1, Sample 5, 25' Depth
Date: November 2012
EARTH ENGINEERING CONSULTANTS, INC.
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
SUMMARY OF LABORATORY TEST RESULTS
100
26
78
78
Sieve Size Percent Passing
100
100
75
69
59
49
40
15
10.7
30
22
Project: 203 W Mulberry St
Project Number:
Sample Desc.: Boring B-1, Sample 5, 25' Depth
Date: November 2012
Summary of Washed Sieve Analysis Tests (ASTM C117 & C136)
Coarse Fine
EARTH ENGINEERING CONSULTANTS, INC.
1122094
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
WHILE DRILLING 20.0'
FINISH DATE 11/5/2012 AFTER DRILLING N/A
SHEET 2 OF 2 WATER DEPTH
START DATE 11/5/2012
LOG OF BORING B-4
203 W MULBERRY STREET
FORT COLLINS, COLORADO
PROJECT NO: 1122094 NOVEMBER 2012
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 11/5/2012 AFTER DRILLING N/A
SHEET 1 OF 2 WATER DEPTH
START DATE 11/5/2012 WHILE DRILLING 20.0'
LOG OF BORING B-4
203 W MULBERRY STREET
FORT COLLINS, COLORADO
PROJECT NO: 1122094 NOVEMBER 2012
SURFACE ELEV N/A
WHILE DRILLING 20.0'
FINISH DATE 11/5/2012 AFTER DRILLING N/A
SHEET 2 OF 2 WATER DEPTH
START DATE 11/5/2012
LOG OF BORING B-3
203 W MULBERRY STREET
FORT COLLINS, COLORADO
PROJECT NO: 1122094 NOVEMBER 2012
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 11/5/2012 AFTER DRILLING N/A
SHEET 1 OF 2 WATER DEPTH
START DATE 11/5/2012 WHILE DRILLING 20.0'
LOG OF BORING B-3
203 W MULBERRY STREET
FORT COLLINS, COLORADO
PROJECT NO: 1122094 NOVEMBER 2012
SURFACE ELEV N/A
WHILE DRILLING 20.0'
FINISH DATE 11/5/2012 AFTER DRILLING N/A
SHEET 2 OF 2 WATER DEPTH
START DATE 11/5/2012
LOG OF BORING B-2
203 W MULBERRY STREET
FORT COLLINS, COLORADO
PROJECT NO: 1122094 NOVEMBER 2012
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 11/5/2012 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 11/5/2012 WHILE DRILLING 20.0'
LOG OF BORING B-2
203 W MULBERRY STREET
FORT COLLINS, COLORADO
PROJECT NO: 1122094 NOVEMBER 2012
SURFACE ELEV N/A
WHILE DRILLING 21.0'
FINISH DATE 11/5/2012 AFTER DRILLING N/A
SHEET 2 OF 2 WATER DEPTH
START DATE 11/5/2012
LOG OF BORING B-1
203 W MULBERRY STREET
FORT COLLINS, COLORADO
PROJECT NO: 1122094 NOVEMBER 2012
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 11/5/2012 AFTER DRILLING N/A
SHEET 1 OF 2 WATER DEPTH
START DATE 11/5/2012 WHILE DRILLING 21.0'
LOG OF BORING B-1
203 W MULBERRY STREET
FORT COLLINS, COLORADO
PROJECT NO: 1122094 NOVEMBER 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