HomeMy WebLinkAboutRIVER DISTRICT BLOCK 8 MIXED-USE - FDP - FDP160025 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTSUBSURFACE EXPLORATION REPORT
360 LINDEN STREET
FORT COLLINS, COLORADO
EEC PROJECT NO. 1142032
Prepared for:
Blue Ocean Enterprises, Inc.
401 Mountain Avenue, Suite 200
Fort Collins, Colorado 80521
Attn: Mr. Brandon Grebe, Construction Manager
brandon.grebe@blueocean-inc.com
Prepared by:
Earth Engineering Consultants, LLC
4396 Greenfield Drive
Windsor, Colorado 80550
4396 GREENFIELD DRIVE
WINDSOR, COLORADO 80550
(970) 545-3908 FAX (970) 663-0282
EARTH ENGINEERING
CONSULTANTS, LLC
April 29, 2014
Blue Ocean Enterprises, Inc.
401 Mountain Avenue, Suite 200
Fort Collins, Colorado 80521
Attn: Mr. Brandon Grebe, Construction Manager (brandon.grebe@blueocean-inc.com)
Re: Subsurface Exploration Report
360 Linden Street
Fort Collins, Colorado
EEC Project No. 1142032
Mr. Grebe:
Enclosed, herewith, are the results of the geotechnical subsurface exploration completed by
Earth Engineering Consultants, LLC (EEC) personnel for the proposed building at 360 Linden
Street in Fort Collins, Colorado.
In summary, the subsurface materials encountered in the five (5) exploration borings
completed on the site generally consisted of approximately 2 to 4½ feet of existing fill
overlying native sand and gravel with intermittent apparent cobbles. The native sand and
gravel with intermittent cobbles extended to sandstone bedrock at approximate depths of 10
feet below existing site grades. The bedrock extended to the depths explored, approximately
14 to 25 feet. Groundwater was encountered in only one of the soil borings at an approximate
depth of 19 feet below site grade at the time of drilling, and 14 feet approximately 24 hours
after drilling.
Based on results of the field borings and laboratory testing, it is our opinion the proposed
building could be supported on a conventional spread footing foundation system bearing on
the native granular subsoils, on approved engineered fill material which extends to the native
granular subsoils, or on the underlying sandstone bedrock. No foundation should be founded
within existing fill materials. Alternative foundation systems could be considered.
SUBSURFACE EXPLORATION REPORT
360 LINDEN STREET
FORT COLLINS, COLORADO
EEC PROJECT NO. 1142032
April 29, 2014
INTRODUCTION
The subsurface exploration you requested for the proposed development of 360 Linden Street in Fort
Collins, Colorado, has been completed. As a part of that exploration, five (5) soil borings extending
to depths of approximately 14 to 25 feet below present site grades were advanced on the
development parcel to obtain 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 construction of a new office/distillery on the referenced
parcel. The proposed building will be 2 to 3 stories above grade and will include a full-depth
basement. A portion of the structure will house the distillery equipment/process within an
approximate 60 foot tall structure. We anticipate maximum wall and column loads for the building
would be on the order of 5 klf and 300 kips, respectively, along with light floor loading conditions.
Specific information concerning proposed site layout and grading was not available to us at the time
of this report. We are basing the recommendations, herein, on assumed cuts and fills of less than 3
feet.
The purpose of this report is to describe the subsurface conditions encountered in the five (5) soil
borings completed on the site, analyze and evaluate the test data and provide geotechnical
recommendations concerning design and construction of the foundations and support of floor slabs.
EXPLORATION AND TESTING PROCEDURES
The boring locations were established in the field by a representative of Earth Engineering
Consultants, LLC (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 considerate accurate only to the degree implied by the methods used to
make the field measurements.
Earth Engineering Consultants, LLC
EEC Project No. 1142032
April 29, 2014
Page 2
The borings were performed 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 continuous flight augers and 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 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. 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. The quantity and
plasticity of the fines in the subgrades were determined by washed sieve analysis and Atterberg
limits tests on selected samples. 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.
SITE AND SUBSURFACE CONDITIONS
The proposed development lot is located at the south corner of the intersection of Linden Street and
Willow Street in Fort Collins. The referenced property is presently open and gravel surfaced with
the surrounding properties developed as light industrial. The property is relatively level with less
Earth Engineering Consultants, LLC
EEC Project No. 1142032
April 29, 2014
Page 3
than 2 to 3 feet of relief across the sites. Photographs of the site were taken during the subsurface
exploration and are included with this report.
An EEC field engineer was on site during the drilling operations to evaluate the subsurface
conditions encountered and direct the drilling activities. Field logs prepared by EEC site personnel
were based on visual and tactual observation of auger cuttings and disturbed samples. The boring
logs included with this report may contain modifications to the field logs based on results of
laboratory testing and engineering evaluation. Based on results of the field boring and laboratory
testing, subsurface conditions can be generalized as follows.
Approximately 4 inches of gravel base course material was observed at the surface at the boring
locations. The materials below the surfacing generally consisted of fill and apparent fill soils
consisting largely of black cinder/coal ash material. The fill soils contained varying zones of cleaner
fills. The fill and apparent fill soils generally extended to depths of approximately 2 to 4½ feet
below current site grades. The consistency of the fill soils was generally in the medium dense to
loose range.
The site apparent fill soils were underlain by medium dense to dense native sands and gravels with
silts and clay in the nearer surface material. The granular soils were typically tan in color and
contained apparent cobbles and variable sand, gravel and fines. The sands and gravels extended to
depths of approximately 10 feet and were underlain by sandstone/siltstone bedrock. The bedrock
was typically cemented/hard and contained zones of well cemented materials. Auger refusal was
encountered in boring B-3 at a depth of approximately 14 feet on apparent well cemented sandstone
bedrock. The borings were terminated at depths of approximately 14 to 25 feet in the bedrock
materials.
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.
WATER LEVEL OBSERVATIONS
Observations were made while drilling and after completion of boring to detect the presence and
depth to apparent groundwater. Groundwater was encountered only in boring B-2 at a depth of
Earth Engineering Consultants, LLC
EEC Project No. 1142032
April 29, 2014
Page 4
approximately 19 feet as the boring was being advanced and rising to a depth of approximately 14
feet the day after drilling. The boreholes were backfilled the day after completion of the drilling
operation; therefore subsequent groundwater measurements 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. In addition, zones of perched
and/or trapped water may be encountered at times throughout the year in more permeable areas
within the subgrade materials. Perched water is commonly observed in more permeable soils
overlying lower permeability bedrock. The location and amount of perched water can also vary over
time depending on variations in hydrologic conditions and other conditions not apparent at the time
of this report.
ANALYSIS AND RECOMMENDATIONS
General Considerations
Precautions will be required in the design and construction of the new building and any new pavements
to address the existing fill material, the removal/excavation of cobbles at increased depths, penetration
of the underlying well cemented sandstone bedrock lenses, and shoring/protection of adjacent
properties during excavation for the proposed basement level of site.
It is anticipated that excavations for the proposed construction can be accomplished with
conventional earthmoving equipment. However, if excavations penetrating the well-cemented
sandstone bedrock are required, the use of specialized heavy-duty equipment such as a rock hammer
or core barrel to achieve final design elevations may be necessary. Consideration should be given to
obtaining a unit price for difficult excavation in the contract documents for the project.
Depending upon the depth and proximity to the property line of lower level construction, a shoring
plan may be necessary to protect the adjacent sidewall slopes. The project design team should use the
subsurface information provided herein to properly design a mechanism for shoring protection. EEC is
available to provide supplemental design criteria or details, such as but not limited to secant piles or
piers, soldier piers, or a tie-back/bracing concepts.
Earth Engineering Consultants, LLC
EEC Project No. 1142032
April 29, 2014
Page 5
Site Preparation
Final site grades were not available at the time of this report. We are basing the recommendations in
this report on an assumption that cuts and fills of less than 2 to 3 feet will be necessary to achieve
design grades with the exception of the basement portions of the building where deeper excavations
will be required. All of the existing fill material should be removed in the new building areas
including adjacent flatwork areas. The in-place fill material does not appear to be acceptable for use
as any site fill. In-place fill materials could probably remain in pavement and landscape areas with
an acknowledgement that some future settlement could occur in the remaining fill areas and that
future settlement could result in differential movements in the overlying improvements.
After stripping, over-excavating as necessary and completing all cuts, and prior to placement of any
fill material or site improvements, we recommend the exposed subsoils be scarified to a minimum
depth of 9-inches, adjusted in moisture content to within ±3% of standard Proctor optimum moisture
content, and compacted to at least 98% of the material's standard Proctor maximum dry density as
determined in accordance with ASTM Specification D698. If cuts extend into zones of cinder
and/or ash fill, scarification and recompaction would generally not be possible. Removal and
replacement of unstable zones of cinder/ash fill may be necessary in near surface subgrades in all
areas not specifically designated as landscaping.
Fill soils required to develop the building, pavement and site subgrades, after the initial subgrade
zone (i.e. the layer beneath any over-excavation requirements) has been stabilized, should consist of
approved, low-volume-change materials which are free from organic matter and debris. We
recommend structural fill materials be placed and compacted within the building footprint and
consist of essentially granular soils. Silty and/or clayey sands or underlying sands and gravels
excluding cobble sized material could be used for fill in these areas. We recommend fill materials
be placed in loose lifts not to exceed 9 inches thick and adjusted in moisture content to within ± 3%
of optimum moisture content, and compacted to at least 98% of the material’s maximum dry density
as determined in accordance with ASTM Specification D698, the standard Proctor procedure.
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
Earth Engineering Consultants, LLC
EEC Project No. 1142032
April 29, 2014
Page 6
subgrade materials. Subgrade materials becoming wet subsequent to construction of the site
structure can result in unacceptable performance.
Foundations – Conventional Type Spread Footings
Based on results of field borings and laboratory testing as outlined in this report, it is our opinion the
proposed building could be supported on conventional type spread footing foundations bearing on
the native granular stratum, on a zone of engineered fill material extending to the native granular
soils, or extending to the underlying sandstone bedrock. In no case should any foundation system be
placed on the existing on-site fill material. Footings bearing on approved native granular subsoils or
on engineered fill material extended to the granular strata could be designed for a maximum net
allowable total load soil bearing pressure of 2,500 psf. Footing foundations extending to the
sandstone bedrock could be designed using a net allowable total load soil bearing pressure not to
exceed 5,000 psf. The net bearing pressure refers to the pressure at foundation bearing level in
excess of the minimum surrounding overburden pressure. Total load includes full dead and live
loads. A minimum dead load pressure would not be required in the low swell potential subsoils and
bedrock.
If fill material is required to achieve foundation bearing elevations, the engineered fill material
should consist of structural fill placed in uniform lifts, properly moisture conditioned, and
compacted to at least 98% of standard Proctor density (ASTM D698). Overexcavation for
placement of the structural fill should extend to the native granular subsoils, and should extend at
least eight (8) inches beyond the edges of the foundations for each 12 inches of structural fill placed
beneath the footings.
Exterior footings and foundations in unheated areas must be protected from frost action. The normal
depth of frost protection in this location is a minimum depth of 30 inches. Continuous wall footings
generally have a width of at least 12 inches. Isolated column pads generally require dimensions of at
least 24 inches by 24 inches. Footings should be proportioned to reduce differential foundation
movement. Proportioning on the basis of equal total settlement is recommended; however,
proportioning to relative constant dead-load pressure will also reduce differential settlement between
adjacent footings. Total settlement resulting from the assumed structural loads is estimated to be on
the order of 1 inch or less. Differential settlement is estimated to be on the order of 1/2 of the
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EEC Project No. 1142032
April 29, 2014
Page 7
estimated total settlement. Additional foundation movements could occur if water from any source
infiltrates the foundation soils; therefore, proper drainage should be provided in the final design and
during construction.
Care should be taken during construction to see that the footing foundations are supported on
similar, suitable strength native subsoils, approved fill material or suitable sandstone bedrock. Extra
care should be taken in evaluating the in-place soils with potentially variable depths of in-place fill
across the site. If unacceptable materials are encountered at the time of construction, it may be
necessary to extend the footing foundations to bear below the unacceptable materials or removal and
replacement of a portion or all of the unacceptable materials may be required. Those conditions can
best be evaluated in open excavations at the time of construction.
No unusual problems are anticipated in completing the excavation required for construction of the
footing foundations. Care should be taken during construction to avoid disturbing the foundation
bearing materials. Materials which are loosened or disturbed by the construction activities or
materials which become dry and desiccated or wet and softened should be removed and replaced
prior to placement of foundation concrete.
Seismic
The site soil conditions consist of approximately 10 feet of overburden granular subsoils overlying
cemented to well-cemented sandstone bedrock. For those site conditions, the 2009 International
Building Code indicates a Seismic Site Classification of C.
Lateral Earth Pressures
The proposed building will include at least a partial full-depth basement as a part of the new
building. Site retaining walls may also be desirable with the grade changes across the site.
Basement walls of the building and/or site retaining walls would be subjected to unbalanced lateral
earth pressures. Passive lateral earth pressures may help resist the driving forces for retaining wall
or other similar site structures. The values presented herein are for approved material placed and
compacted adjacent to the site structures.
Earth Engineering Consultants, LLC
EEC Project No. 1142032
April 29, 2014
Page 8
Active lateral earth pressures could be used for design of structures where some movement of the
structure is anticipated, such as retaining walls. The total deflection of structures for design with
active earth pressure is estimated to be on the order of one half of one percent of the height of the
down slope side of the structure. We recommend at-rest pressures be used for design of structures
where rotation of the walls is restrained, such as basement walls. Passive pressures and friction
between the footing and bearing soils could be used for design of resistance to movement of
retaining walls.
Coefficient values for backfill with the anticipated types of fill/backfill soil for calculation of active,
at rest and passive earth pressures are provided in the table below. Equivalent fluid pressure is equal
to the coefficient times the appropriate soil unit weight. Those coefficient values are based on
horizontal backfill with backfill soils consisting of essentially granular materials with a friction
angle of 30 degrees. For the at-rest and active earth pressures, slopes down and away from the
structure would result in reduced driving forces with slopes up and away from the structures
resulting in greater forces on the walls. The passive resistance would be reduced with slopes away
from the wall. The top 30 inches of soil on the passive resistance side of walls could be used as a
surcharge load; however, should not be used as a part of the passive resistance value. Frictional
resistance is equal to the tangent of the friction angle times the normal force. Surcharge loads or
point loads placed in or on the backfill can also create additional loads on below grade walls. Those
situations should be designed on an individual basis.
Soil Type – ONLY FOR APPROVED
MATERIALS Medium Dense Granular – On-site or Approved Imported Fill
Wet Unit Weight (pcf) 135
Saturated Unit Weight (pcf) 140
Friction Angle () – (assumed) 30°
Active Pressure Coefficient 0.33
At-rest Pressure Coefficient 0.50
Passive Pressure Coefficient 3.00
The outlined values do not include factors of safety nor allowances for hydrostatic loads and are
based on assumed friction angles, which should be verified after potential material sources have
been identified. Care should be taken to develop appropriate drainage systems behind below grade
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EEC Project No. 1142032
April 29, 2014
Page 9
walls to eliminate potential for hydrostatic loads developing on the walls. Those systems would
likely include perimeter drain systems extending to sump areas or free outfall where reverse flow
cannot occur into the system. Where necessary, appropriate hydrostatic load values should be used
for design.
Floor Slab Subgrades
All existing vegetation/topsoil and/or existing pavement and associated site fill materials should be
removed from beneath the new building at-grade floor slab area(s). The subgrades should be
prepared as outlined under “Site Preparation” in this report. Floors could be supported directly on
the placed structural fill soils.
After preparation of the subgrades, care should be taken to avoid disturbing the subgrade materials.
Materials which are loosened or disturbed by the construction activities will require removal and
replacement or reworking in place prior to placement of the overlying floor slabs.
Positive drainage should be developed away from the proposed building addition to avoid wetting
the subgrade or bearing materials. Subgrade or bearing materials allowed to become wetted
subsequent to construction can result in unacceptable performance of the improvements.
Other Considerations
Positive drainage should be developed away from the structure and pavement areas with a minimum
slope of 1 inch per foot for the first 10 feet away from the improvements in landscape areas. Care
should be taken in planning of landscaping adjacent to the building and parking and drive areas to
avoid features which would pond water adjacent to the pavement, foundations or stemwalls.
Placement of plants which require irrigation systems or could result in fluctuations of the moisture
content of the subgrade material should be avoided adjacent to site improvements. Lawn watering
systems should not be placed within 5 feet of the perimeter of the building and parking areas. Spray
heads should be designed not to spray water on or immediately adjacent to the structure or site
pavements. Roof drains should be designed to discharge at least 5 feet away from the structure and
away from the pavement areas.
Earth Engineering Consultants, LLC
EEC Project No. 1142032
April 29, 2014
Page 10
Excavations into the on-site soils may encounter a variety of conditions. Excavations extending into
the on-site fill zone and native granular strata may encounter loose and caving conditions. The
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 and taking into
account the site subsurface conditions as described herein. 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 further exploration or
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 that 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 for representatives with Blue Ocean Enterprises,
Inc., 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 modified or verified in
writing by the geotechnical engineer.
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 <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
1
Cu<6 and/or 1>Cc>3
E SP Poorly‐graded sand
1
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)
D x D
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
Gravels with Fines
more than 12%
fines
Clean Sands Less
than 5% fines
Sands with Fines
360 LINDEN STREET
FORT COLLINS, COLORADO
EEC PROJECT NO. 1142032
APRIL 2014
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
GRAVEL - 4" _ _
1
FILL: Miscellaneous Soil with Cinders & Apparent Coal Ash _ _
black / brown 2
with coal chunks _ _
3
_ _
4
_ _
CS 5 9 4000 8.9 115.9
CLAYEY SAND (SC) _ _
brown, medium dense to loose 6
_ _
7
SAND & GRAVEL (SP/GP) _ _
brown 8
medium dense _ _
9
_ _
SS 10 50/10" -- 1.8
_ _
SANDSTONE / SILTSTONE 11
brown / rust _ _
poorly cemented to cemented 12
with intermittent well cemented lenses _ _
13
_ _
14
_ _
CS 15 50/1" -- 10.4
_ _
16
_ _
17
_ _
18
_ _
19
_ _
grey SS 20 50/0.5" 9000+ 14.3
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 50/0.5" 9000+ 11.8
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
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
GRAVEL - 4" _ _
1
FILL: Miscellaneous Soil with Cinders & Apparent Coal Ash _ _
brown / black 2
_ _
3
_ _
4
_ _
CLAYEY SAND (SC) CS 5 9 8500 10.9 121.2 <500 psf None
brown _ _
medium dense to loose 6
_ _
7
_ _
8
1' gravel seam _ _
9
_ _
SS 10 50/7" -- 10.3
SANDSTONE _ _
brown / rust 11
poorly cemented to cemented _ _
with intermittent well cemented zones 12
_ _
13
_ _
14
grey _ _
CS 15 50/1" 9000+ 12.3
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 50/2" 9000+ 14.9
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 50/0.5" 9000+ 9.4
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
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
GRAVEL - 4" _ _
1
FILL - Miscellaneous Soil with Cinders & Apparent Coal As _ _
brown / black 2
_ _
CLAYEY SAND (SC) CS 3 7 3500 7.5 116.0
brown _ _
medium dense to loose 4
_ _
SS 5 4 6000 8.9
_ _
6
_ _
SAND & GRAVEL (SP/GP) 7
brown _ _
medium dense 8
_ _
9
_ _
CS 10 50/5" -- 3.8
_ _
SANDSTONE/SILTSTONE 11
brown / rust _ _
poorly cemented to cemented 12
_ _
13
_ _
14
BOTTOM OF BORING DEPTH 14.0' _ _
Auger Refusal on Apparent Well Cemented SS 15 Bounce 9000+ 12.4
Sandstone _ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
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
GRAVEL - 4" _ _
1
FILL - Miscellaneous Soil with Cinders & Apparent Coal As _ _
brown / black 2
_ _
3
_ _
4
_ _
CLAYEY SAND (SC) CS 5 10 7500 11.8 120.0
brown, medium dense _ _
6
SAND & GRAVEL (SP/GP) _ _
brown 7
medium dense _ _
8
_ _
9
_ _
SS 10 50 -- 1.9
_ _
11
SANDSTONE/SILTSTONE _ _
brown / rust 12
poorly cemented to cemented _ _
13
_ _
14
_ _
with intermittent well cemented lenses CS 15 --
_ _
16
_ _
17
_ _
18
_ _
19
_ _
grey SS 20 50/0.5" 9000+ 13.8
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 50/0.5"
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
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
_ _
FILL: LEAN CLAY (CL) with Apparent Cinders & Coal Ash 1
brown / black _ _
2
_ _
CS 3 10 9000+ 11.7 113.8
_ _
4
_ _
CLAYEY GRAVEL, brown, medium dense SS 5 34 6000 14.3
_ _
SAND & GRAVEL (SP/GP) 6
brown _ _
medium dense 7
_ _
8
_ _
9
_ _
CS 10 50/8" -- 1.1 132.4
_ _
SANDSTONE 11
grey / olive _ _
poorly cemented to cemented 12
with intermittent well cemented zones _ _
13
_ _
14
_ _
SS 15 50/3" 9000+ 14.0
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 50/1.5" 9000+ 13.7
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 50/1.5" 9000+ 13.7
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
Project:
Location:
Project #:
Date:
360 Linden Street
Fort Collins, Colorado
1142032
April 2014
Beginning Moisture: 10.9% Dry Density: 121.2 pcf Ending Moisture: 12.8%
Swell Pressure: <500 psf % Swell @ 500: None
Sample Location: Boring 2, Sample 1, Depth 4'
Liquid Limit: Plasticity Index: % Passing #200:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Clayey Sand (SC)
-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
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 4/16/2014 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 4/16/2014 WHILE DRILLING None
360 LINDEN STREET
FORT COLLINS, COLORADO
PROJECT NO: 1142032 LOG OF BORING B-5 APRIL 2014
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 4/16/2014 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 4/16/2014 WHILE DRILLING None
360 LINDEN STREET
FORT COLLINS, COLORADO
PROJECT NO: 1142032 LOG OF BORING B-4 APRIL 2014
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 4/16/2014 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 4/16/2014 WHILE DRILLING None
360 LINDEN STREET
FORT COLLINS, COLORADO
PROJECT NO: 1142032 LOG OF BORING B-3 APRIL 2014
SURFACE ELEV N/A 24 HOUR 14.0'
FINISH DATE 4/16/2014 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 4/16/2014 WHILE DRILLING 19.0'
360 LINDEN STREET
FORT COLLINS, COLORADO
PROJECT NO: 1142032 LOG OF BORING B-2 APRIL 2014
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 4/16/2014 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 4/16/2014 WHILE DRILLING None
360 LINDEN STREET
FORT COLLINS, COLORADO
PROJECT NO: 1142032 LOG OF BORING B-1 APRIL 2014
more than 12%
fines
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
CGravels with 5 to 12% fines required dual symbols: gravel, add "gravelly" to group name.
UNIFIED SOIL CLASSIFICATION SYSTEM
Soil Classification
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests
Sands 50% or more
coarse fraction
passes No. 4 sieve
Fine‐Grained Soils
50% or more passes
the No. 200 sieve
<0.75
Kif soil contains 15 to 29% plus No. 200, add "with sand"
or "with gravel", whichever is predominant.
OL
<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/D1 Cc=
Silts and Clays
Liquid Limit less
than 50
Silts and Clays
Liquid Limit 50 or
more
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
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.
0
10
20
30
40
50
60
0102030405060708090100110
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