HomeMy WebLinkAbout20061359.tiff Soil Survey of Weld County,Colorado excerpt(Southern Portion)
Published by the United States Department of Agriculture Soil Conservation Service
Soil Classification#32: Kim loam, 1 to 3 percent slopes
This is a deep,well drained soil on smooth plains and alluvial fans at elevations of 4,900 to 5,250 feet. It
formed in mixed eolian deposit and parent sediment from a wide variety of bedrock. Included in mapping are
small areas of soils that have loamy sand underlying material.
Typically the surface layer is brown and pale brown loam about 12 inches thick. The upper 28 inches
of the underlying material is pale brown loam. The lower part to a depth of 60 inches is pale brown fine sandy
loam.
Permeability is moderate. Available water capacity is high. The effective rooting depth is 60 inches
or more. Surface runoff is medium,and the erosion hazard is low.
In irrigated areas this soil is suited to all crops commonly grown in the area,including corn,sugar
beets,beans,alfalfa,small grain,potatoes,and onions. An example of a suitable cropping system is 3 to 4
years of alfalfa followed by corn,corn for silage,sugar beets,small grain,or beans. Land leveling,ditch lining
(fig.6),and installing pipelines may be needed for proper water applications.
All methods of irrigation are suitable,but furrow irrigation is the most common. Barnyard manure
and commercial fertilizer are needed for top yields.
In nonirrigated areas this soil is suited to winter wheat,barley,and sorghum. Most of the acreage is
planted to winter wheat and is summer fallowed in alternate years to allow moisture accumulation. Generally
precipitation is too low for beneficial use of fertilizer.
Stubble mulch farming,striperopping,and minimum tillage are needed to control soil blowing and
water erosion. Terracing also may be needed to control water erosion.
The potential native vegetation is dominated by blue grama. Several mid grasses, such as western
wheatgrass and needleandthread,are also present. Potential production ranges from 1,600 pounds per acre in
favorable years to 1,000 pounds in unfavorable years. As range condition deteriorates,the mid grasses
decrease;blue grama,buffalograss,snakeweed,yucca,and fringed sage increase;and forage production drops.
Undesirable weeds and annuals invade the site as range condition becomes poorer.
Management of vegetation on this soil should be based on taking half and leaving half of the total
annual production. Seeding is desirable if the range is in poor condition. Sideoats grama,little bluestem,
western wheatgrass,blue grama pubescent wheatgrass,and crested wheatgrass are suitable for seeding. The
grass selected should meet the seasonal requirements of livestock. It can be seeded into clean, firm sorghum
stubble,or it can be drilled into a firm prepared seedbed. Seeding early in spring has proven most successful.
Windbreaks and environmental plantings of trees and shrubs commonly grown in the area are
generally well suited to this soil. Cultivation to control competing vegetation should be continued for as many
years as possible following planting. Trees that are best suited and have good survival are Rocky Mountain
juniper,eastern redcedar,ponderosa pine,Siberian elm,Russian-olive,and hackberry. The shrubs best suited
are skunkbush sumac,lilac, Siberian peashrub,and American plum.
Wildlife is an important secondary use of this soil. The cropland areas provide favorable habitat for
ring-necked pheasant and mourning dove. Many nongame species can be attracted by establishing areas for
nesting and escape cover. For pheasants,undisturbed nesting cover is essential and should be included in
plans for habitat development,especially in areas of intensive agriculture. Rangeland wildlife,for example,
the pronghorn antelope,can be attracted by developing livestock watering facilities,managing livestock
grazing,and reseeding where needed.
This soil has good potential for urban and recreational development. Increased population growth in
the survey area has resulted in increased homesite construction. The chief limiting soil feature for urban
development and road construction is the limited capacity of this soil to support a load. Septic tank absorption
fields function property,but community sewage systems should be provided if the population density
increases. Because of the permeability of the substratum,sewage lagoons must be sealed. Lawns,shrubs,and
trees grow well. Capability subclass Ile irrigated,IVe nonirrigated; Loamy Plains range site.
2006-1359
Soil Survey of Weld County,Colorado excerpt(Southern Portion)
Published by the United States Department of Agriculture Soil Conservation Service
Soil Classification#47: Olney fine sandy loam, 1 to 3 percent slopes.
This is a deep,well drained soil on plains at elevations of 4,600 to 5,200 feet. It formed in mixed
outwash deposits. Included in mapping are small areas of soils that have a dark surface layer. Some
small leveled areas are also included.
Typically the surface layer of this Olney soil is grayish brown fine sandy loam about 10 inches
thick. The subsoil is yellowish brown and very pale brown sandy clay loam about 14 inches thick. The
substratum to a depth of 60 inches is very pale brown,calcareous fine sandy loam.
Permeability and available water capacity are moderate. The effective rooting depth is 60 inches
or more. Surface runoff is medium,and the erosion hazard is low.
In irrigated areas this soil is suited to all crops commonly grown in the area, including corn,sugar
beets, beans,alfalfa, small grain,potatoes,and onions. An example of suitable cropping system is 3 to 4
years of alfalfa followed by corn,corn for silage,sugar beets, small grain,or beans. Land leveling,ditch
lining,and installing pipelines may be needed for proper water application. All methods of irrigation are
suitable,but furrow irrigation is the most common. Barnyard manure and commercial fertilizer are
needed for top yields.
In nonirrigated areas this soil is suited to winter wheat,barley,and sorghum. Most of the acreage
is planted to winter wheat. The predicted average yield is 28 bushels per acre. The soil is summer
fallowed in alternate years to allow moisture accumulation. Generally precipitation is too low for
beneficial use of fertilizer.
Stubble mulch farming, striperopping,and minimum tillage are needed to control soil blowing
and water erosion. Terracing also may be needed to control water erosion.
The potential native vegetation on this range site is dominated by sand bluestem, sand reedgrass,
and blue grama. Needleandthread,switchgrass, sideoats grama,and western wheatgrass are also
prominent. Potential production ranges from 2,200 pounds per acre in favorable years to 1,800 pounds in
unfavorable years. As range condition deteriorates,the sand bluestem,sand reedgrass,and switchgrass
decrease and blue grams, sand dropseed,and sand sage increase. Annual weeds and grasses invade the
site as range condition becomes poorer.
Management of vegetation on this soil should be based on taking half and leaving half of the total
annual production. Seeding is desirable if the range is in poor condition. Sand bluestem, sand reedgrass,
switchgrass,sideoats grama,blue grama,and pubescent wheatgrass are suitable for seeding. The grass
selected should meet the seasonal requirements of livestock. It can be seeded into clean,firm sorghum
stubble,or it can be drilled into a firm prepared seedbed. Seeding early in spring has proven most
successful.
Windbreaks and environmental plantings are generally suited to this soil. Soil blowing,the
principal hazard in establishing trees and shrubs, can be controlled by cultivating only in the tree row and
by leaving a strip of vegetation between the rows. Supplemental irrigation may be needed at the time of
planting and during dry periods. Trees that are best suited and have good survival are Rocky Mountain
juniper,eastern redcedar,ponderosa pine, Siberian elm,Russian-olive,and hackberry. The shrubs best
suited are skunkbush sumac, lilac,and Siberian peashrub.
Wildlife is an important secondary use of this soil. The cropland areas provide favorable habitat
for ring-necked pheasant and mourning dove. Many nongame species can be attracted by establishing
areas for nesting and escape cover. For pheasants,undisturbed nesting cover is essential and should be
included in plans for habitat development,especially in areas of intensive agriculture. Rangeland
wildlife,for example,the pronghorn antelope, can be attracted by developing livestock watering facilities,
managing livestock grazing,and reseeding where needed.
Rapid expansion of Greeley and the surrounding area has resulted in urbanization of much of the
Olney soil. This soil has good potential for urban and recreational development. The only limiting
feature is the moderately rapid permeability in the substratum,which causes a hazard of ground water
contamination from sewage lagoons. Lawns, shrubs,and trees grow well. Capability subclass IIe
irrigated, IVe nonirrigated;Sandy Plains range site.
FEMA Community Panel
Panel Numbers 080266 0489C
Map Date: 9/28/82
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U.S.D.A. Soil Survey of Weld County,Colorado
Southern Part,Sheet Number 7
Applicable Soil Narratives: 32 and 47
Narrative described on the following page.
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32 3•10 . 1 :
SUBSURFACE EXPLORATION REPORT
GATEWAY EVENT CENTER
EATON, COLORADO
EEC PROJECT NO. 1052126
E EC
EARTH ENGINEERING
CONSULTANTS, INC.
September 20, 2005
Church Barn, LLC.
134 Oak Avenue
Eaton, Colorado 80615
Attn: Mr. Joe Hoff
Re: Subsurface Exploration Report
Gateway Event Center
Eaton, Colorado
EEC Project No. 1052126
Mr. Hoff:
Enclosed, herewith, are the results of the geotechnical subsurface exploration completed
by Earth Engineering Consultants, Inc. personnel for the referenced project. In summary,
the subsurface soils encountered in the three (3) test borings completed within the
proposed building area consisted of light brown, silty, sandy, lean clay underlain by
weathered sandstone. Groundwater was observed at a depth of approximately 12.5 feet
in boring B-5 at the time of drilling.
Based on the materials we observed at the boring locations, it is our opinion the two-story
metal structural could be supported on conventional footing foundations bearing on the
near surface, sandy lean clay. The near surface soils also appear usable for direct support
of floor slabs and pavements. Slightly higher swell was observed in one sample on the
site. Care will be needed to avoid placing improvements on or immediately above higher
swell potential soils. Geotecimical recommendations concerning design and construction
of foundations and support of floor slabs and pavements are contained in the following
report.
4396 GREENFIELD DRIVE
WINDSOR, COLORADO 80550
(970) 224-1522 FAX (970) 663-0282
Earth Engineering Consultants,Inc.
EEC Project No. 1052126
September 20,2005
Page 2
We appreciate the opportunity to be of service to you on this project. If you have any
questions concerning the enclosed report, or if we can be of further service to you in any
other way, please do not hesitate to contact us.
Very truly yours,
Earth Engineering Consultants, Inc.
Reviewed by:
23957
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mac _ccl
Michael R. Steen, P.G. r, Lester L. Litton, P.E.
Project Manager Principal Engineer
MRS/LLL/cgw
SUBSURFACE EXPLORATION REPORT
GATEWAY EVENT CENTER
EATON, COLORADO
EEC PROJECT NO. 1052126
September 20, 2005
INTRODUCTION
The subsurface exploration for the Gateway Event Center to be located on the northwest
corner at the intersection of Weld County Roads 33 and 70 in Weld County, Colorado, has
been completed. Three(3) soil borings extending to depths of approximately 15 feet below
present site grades were advanced in the area of the proposed structure to obtain information
on existing subsurface conditions. One other boring was advanced in the proposed detention
pond area and an auger boring and percolation test were completed in a proposed leach field
area of the site. Individual boring logs and a diagram indicating the approximate boring
locations are included with this report.
We understand the proposed two-story metal structure is approximately 22,000 square feet in
plan area.The structure will be non-basement, slab-on-grade construction. Foundation loads
for the proposed structure are expected to be light with continuous wall loads less than 3 kips
per lineal foot and individual column loads less than 100 kips.Floor loads are expected to be
light. Drive and parking areas are expected for moderate volumes of light vehicles,
automobiles and light trucks. Small cuts and fills are expected to develop final site grades.
The purpose of this report is to describe the subsurface conditions encountered in the borings,
analyze and evaluate the test data and provide geotechnical recommendations concerning
design and construction of foundations and support of floor slabs and pavements. Results of
percolation testing in the designated septic leach field area are also provided.
EXPLORATION AND TESTING PROCEDURES
The boring locations were selected and established in the field by Earth Engineering
Consultants, Inc. (EEC)personnel by estimating angles and distances from identifiable site
features. The locations of the borings should be considered accurate only to the degree
implied by the methods used to make the field measurements. A boring location diagram is
provided with this report.
Earth Engineering Consultants,Inc.
EEC Project No. 1052126
September 20,2005
Page 2
The borings were performed using a truck mounted CME-45 drill rig equipped with a
hydraulic head employed in drilling and sampling operations. The boreholes were advanced
using 4-inch nominal diameter, solid stem continuous flight augers. Samples of the
subsurface materials encountered were obtained using split-barrel and California barrel
sampling procedures in general accordance with ASTM Specification D-1586. In addition,
one relatively undisturbed sample was obtained in a hydraulically pushed thin-walled
`Shelby' tube sampler in general accordance with ASTM Specification D-1587.All samples
obtained in the field were sealed and returned to the laboratory for further examination,
classification and testing.
Moisture content tests were performed on each of the recovered samples. In addition,
selected samples were tested for fine content and plasticity by washed sieve analysis and
Atterberg limits tests. Swell/consolidation tests were completed on selected samples to
evaluate the tendency of the subgrade soils to change volume with variation in moisture
content. Results of the outlined tests are indicated on the attached boring logs and summary
sheets.
As a part of the testing program,all samples were examined in the laboratory by an engineer
and classified in accordance with the attached General Notes and the Unified Soil
Classification System,based on the texture and plasticity of the soil samples. The estimated
group symbol for the Unified Soil Classification System is shown on the boring logs.A brief
description of the Unified Soil Classification System is included with this report.
SITE AND SUBSURFACE CONDITIONS
The Gateway Event Center site is located on the northwest corner at the intersection of Weld
County Roads 33 and 70 in Weld County, Colorado. The site was vegetated and relatively
level at the time of our field work. Site drainage is generally to the east. A pre-existing
metal structure and corral were located north of the proposed structure. Photographs of the
site are included with this report.
Earth Engineering Consultants,Inc.
EEC Project No. 1052126
September 20,2005
Page 3
A representative of EEC was on site during drilling to direct the drilling activities and
evaluate the subsurface materials encountered. Field descriptions of the materials
encountered were based on visual and tactual observation of disturbed samples and auger
cuttings. 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
field and laboratory evaluation, subsurface conditions can be generalized as follows.
Approximately 3 to 6 inches of vegetation and/or topsoil were encountered at the surface at
the test boring locations. The topsoil/vegetation was typically underlain by sandy, light
brown lean clay.The sandy clay extended to approximately 10 feet below present site grades
in borings B-3 and B-4, and approximately 13 to 14 feet in borings B-2 and B-5. Weak
sandstone bedrock was encountered beneath the lean clay at those boring locations. The
sandstone bedrock extended to approximately 15 feet below present site grades, where the
borings were terminated. Boring B-1 was terminated at a depth of approximately 10 feet in
-- the lean clay soils.
The clay soils encountered in boring B-4 and B-5 were generally firm to stiff with low swell
potential at current moisture and density conditions. Softer clay soil was encountered in
boring B-5 at approximately 6.5 feet to 13.5 feet below present site grades and the clay soil
encountered in boring B-3 at approximately 2.5 feet below present site grades showed
moderate swell potential at current moisture and density conditions. Further testing at the
time of construction should be undertaken to determine the extent of the moderately
swelling,clay soil encountered in boring B-3 and the soft,clay soil encountered in boring B-
5.
The stratification boundaries indicated on the boring logs represent the approximate location
of changes in soil types. In-situ, the transition of materials may be gradual and indistinct.
GROUNDWATER OBSERVATIONS
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, groundwater was
Earth Engineering Consultants,Inc.
EEC Project No. 1052126
September 20,2005
Page 4
encountered at approximately 12.5 feet below present site grades in boring B-5.
Groundwater was also observed at depths of 6 to 8 feet in the borings completed in the
detention pond and septic field areas.
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. Perched groundwater
may also be encountered in more permeable zones in the subgrade soils at times throughout
the year. Perched water is commonly encountered in more permeable soils overlying less
permeable clay or weathered bedrock.
ANALYSIS AND RECOMMENDATIONS
General
The swell potential of the site soils was generally low. However, clay soil with moderate
swell potential was observed at boring B-3, which is in the south east section of the site.
Care will be needed to see that the site improvements are not placed directly on or
immediately above moderately swelling soils.Care should also be taken to properly moisture
condition these soils prior to placement as fill in any structure or flatwork area.
Site Preparation
All existing vegetation and/or topsoil should be removed from beneath fill, pavement and
building subgrade areas. The stripping depth should be expected to vary across the site,
although 2 to 6 inches of stripping is expected from the test borings. After stripping and
completing all cuts and prior to placement of any fill, pavements, or site concrete we
recommend the exposed soils be scarified to a minimum depth of 9 inches,adjusted to within
±2%of 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 D-698.
Fill soils required to develop the building or pavement subgrades should consist of approved,
low-volume-change materials which are free from organic matter and debris. The on-site,
Earth Engineering Consultants,Inc.
EEC Project No. 1052126
September 20,2005
Page 5
non-expansive, sandy lean clay could be used as fill in these areas. We recommend the fill
soils be placed in loose lifts not to exceed 9 inches thick and adjusted in moisture content and
compacted as recommended for the scarified soils.
Care should be exercised after preparation of the subgrades to avoid disturbing the subgrade
materials. Positive drainage should be developed away from the structures and across and
away from the pavement edges to avoid wetting of subgrade materials. Subgrade materials
becoming wet subsequent to construction of the building and/or pavements can result in
unacceptable performance of those improvements over time.
Foundations
Based on materials observed at the test boring locations, it is our opinion that the proposed
lightly loaded structure proposed for this site could be supported on conventional footing
foundations bearing in the near surface lean clay soils. Occasional soft zones were
encountered with depth in the completed site borings such that care will be needed to insure
foundations are supported on suitable strength materials. For design of footing foundations
bearing in suitable strength natural, medium stiff lean clay, we recommend using a net
allowable total load soil bearing pressure not to exceed 1,500 psf. The net bearing pressure
refers to the pressure at foundation bearing level in excess of the minimum surrounding
overburden pressure. Total load should include full dead and live loads.
Exterior foundations and foundations in unheated areas should be located at least 30 inches
below adjacent exterior grade to provide frost protection. We recommend formed continuous
footings have a minimum width of 16 inches and isolated column foundations have a
minimum width of 30 inches. Trenched foundations or grade beam foundations could be
used in the near surface essentially cohesive soils. If used we recommend trenched
foundations have a minimum width of 16 inches with formed grade beam foundations having
a minimum width of 12 inches.
Care should be taken during construction to see that footing foundations are supported on
suitable strength natural soils. Soft zones, if encountered, will require removal and
Earth Engineering Consultants,Inc.
EEC Project No. 1052126
September 20,2005
Page 6
replacement prior to construction of the footing foundations. Care will also be needed to
evaluate the swell potential of the bearing materials. High swell potential may necessitate
removal and replacement of bearing or subgrade materials.
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.
We estimate the long-term settlement of footing foundations designed and constructed as
outlined above would be less than 1 inch.
Floor Slab, Flatwork and Pavement Subgrades
Some zones of dryer lean clay soils were encountered near surface in areas of the
development site. The swell potential of those materials was such that care should be taken
to maintain and/or adjust the moisture content of the subgrade soils to an acceptable level
prior to placement of floor slab and flatwork concrete and site pavements. If the near surface
soils are allowed to dry out appreciably prior to concrete placement, some reworking of the
subgrade soils in-place and/or overexcavation/backfill procedures would be expected.
All existing vegetation and/or topsoil should be removed from beneath floor slab and
pavement areas. That removal depth should be expected to vary across the site based on
varying topsoil/vegetation depths.
After stripping and completing all cuts and prior to placement of any fill, floor slabs or
pavements, we recommend the exposed soils be proofrolled to help locate any soft or loose
zones in the near surface subgrades. Soft or loose zones observed during proofrolling would
require removal and replacement or reworking in place prior to placement of fill,floor slabs
or pavements. After proofrolling, we recommend the exposed subgrades be scarified to a
minimum depth of 9 inches, adjusted in moisture content and compacted to at least 95%of
standard Proctor(ASTM Specification D-698)maximum dry density. The moisture content
r
Earth Engineering Consultants,Inc.
EEC Project No. 1052126
September 20,2005
Page 7
of the scarified soils should be adjusted to be within the range of±2% of standard Proctor
optimum moisture at the time of compaction.
Fill soils required to develop floor slab, flatwork, or pavement subgrades should consist of
approved,low-volume change materials which are free from organic matter and debris.The
near surface site lean clay could be used as fill beneath the floor slabs or pavements. If off-
site materials are used,they should consist of approved low-volume change materials with a
minimum of 15 percent fines(material passing the#200 size sieve). Those fill soils should
be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content as
recommended for the scarified soils and compacted to at least 95%of the material's standard
Proctor maximum dry density. More heavily loaded floor slabs may require a greater degree
of compaction for the fill materials.
After preparation of the subgrades, care should be taken to avoid disturbing the in-place
materials. Subgrade 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 or reworked in place prior to placement of the overlying floor slabs or pavements.
Site Pavements
We expect traffic on the site pavements will consist predominately of low to moderate
volumes of automobiles and light trucks. We anticipate the subgrades in those areas will
consist of low to moderate plasticity sandy lean clay.
Alternative composite,full depth asphalt and concrete pavement sections are provided below
in Table 1 for both light and heavy-duty pavement areas. Those pavement sections are based
on assumed traffic volumes. Light duty areas would include pavements for low to moderate
traffic consisting of automobiles and light trucks. Heavy duty areas would include pavement
subjected to higher traffic volume and/or heavier truck traffic. A Hveem R-value of 5 was
estimated for the sandy clay subgrades. Although the full depth asphalt section is
numerically equivalent to the composite section, it has been our experience the composite
Earth Engineering Consultants,Inc.
EEC Project No. 1052126
September 20,2005
Page 8
section would likely perform better.
TABLE 1 —PAVEMENT SECTION RECOMMENDATIONS
Light Duty Heavy Duty
Alternative A—Composite Section
Surface Asphalt(Grading S or SX) 4" 5"
Aggregate Base (Class 5 or 6) 6" 8"
Alternative B—Full Depth Asphalt
Surface Asphalt(Grading S or SX) 2W Not
Base Asphalt(Grading SG) 3" Recommended
Alternative C—Portland Cement Concrete Pavement 5" 6"
Asphalt surfacing should consist of grading S(3/4 inch minus)or grading SX hot bituminous
pavement consistent with CDOT requirements. Grading SG could be used for base asphalt
for the full-depth asphaltic concrete section. Aggregate base should be consistent with
CDOT requirements for Class 5 or Class 6 aggregate base.
Portland cement concrete, if used, should have a minimum 28-day design compressive
strength of 3,500 psi and should be air entrained. The recommended Portland Cement
Concrete pavement section is based on non-reinforced concrete although woven wire or fiber
mesh should be considered for control of shrinkage cracks. In dumpster or truck loading and
unloading areas, asphalt pavement sections subject to increased loads and truck turning
movements would likely show poor performance. We recommend concrete pavement
sections be considered in these areas.
Earth Engineering Consultants,Inc.
EEC Project No. 1052126
September 20,2005
Page 9
The recommended pavement sections are minimums and, as such, periodic maintenance
should be expected. Areas expected to carry heavier trucks or higher volumes of trucks may
require thicker pavement sections. Alternative pavement sections could also be considered
and we would be pleased to review any alternatives at your request.
The essentially cohesive site soils would be subject to strength loss and instability when
wetted. Pumping of the pavement subgrades may occur if development is completed during
wet periods of the year or pavement subgrades contain excessive moisture. Stabilization of a
portion of the pavement subgrades may be required prior to paving. If desired, stabilized
subgrades could be incorporated as part of the pavement sections resulting in a reduction in
the base and asphalt for the roadways. We would be pleased to provide recommendations
concerning fly ash or other alternative stabilization procedures at your request.
Other Considerations
Positive drainage should be developed away from the new structure and across and away
from the edges of the site pavements. Water allowed to pond on or adjacent to the
pavements or adjacent to the buildings can result in poor performance of those
improvements.
Care should be taken when planning landscaping adjacent to the structures to avoid features
which could pond water adjacent to the foundations or stem walls. Roof drains should be
designed to discharge at least 5 feet away from the structures and away from the pavement
areas.
Soils from the detention pond area could be used for site fill. Groundwater was observed in
this area at depths of 6 to 8 feet. Soils near these depths will require drying prior to
placement as fill. The soils near the water table would be unstable under construction traffic.
Cuts greater than 3 to 4 feet in this area will likely require backhoe excavation.
The soils in the septic area show percolation rates favorable to the use of a conventional
leach field. Groundwater depths met the required depth of 6 feet below ground surface at the
Earth Engineering Consultants,Inc.
EEC Project No. 1052126
September 20,2005
Page 10
time of our observation. However,monitoring of the groundwater level should be considered
to establish seasonal high groundwater. Raising the surface level on the order of 1 to2 feet in
this area could also help maintain suitable separation from groundwater level.
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 then 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 of Church Barn 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 modified
or verified in writing by the geotechnical engineer.
DRILLING AND EXPLORAT1 J NI
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 PHYSICAL PROPERTIES OF BEDROCK
Soil Classification is based on the Unified Soil Classification DEGREE OF WEATHERING:
system and the ASTM Designations D-2488. Coarse Grained Slight Slight decomposition of parent material on
Soils have move than 50%of their dry weight retained on a#200 joints. May be color change.
sieve;they are described as: boulders,cobbles,gravel or sand. Moderate Some decomposition and color change
Fine Grained Soils have less than 50% of their dry weight throughout.
retained on a#200 sieve;they are described as : clays, if they High Rock highly decomposed, may be extremely
are plastic, and silts if they are slightly plastic or non-plastic. broken.
Major constituents may be added as modifiers and minor HARDNESS AND DEGREE OF CEMENTATION:
constituents may be added according to the relative proportions Limestone and Dolomite:
based on grain size. In addition to gradation, coarse grained Hard Difficult to scratch with knife.
soils are defined on the basis of their relative in-place density Moderately Can be scratched easily with knife.
and fine grained soils on the basis of their consistency.
Example: Lean clay with sand, trace gravel, stiff(CL); silty Hard Cannot be scratched with fingernail.
sand,trace gravel,medium dense(SM). Soft Can be scratched with fingernail.
CONSISTENCY OF FINE-GRAINED SOILS Shale, Siltstone and Claystone:
Hard Can be scratched easily with knife,cannot be
Unconfined Compressive scratched with fingernail.
Strength, Qu,psf Consistency Moderately Can be scratched with fingernail.
Hard
< 500 Very Soft Soft Can be easily dented but not molded with
500- 1,000 Soft fingers.
1,001 - 2,000 Medium Sandstone and Conglomerate:
2,001 - 4,000 Stiff Well Capable of scratching a knife blade.
4,001 - 8,000 Very Stiff Cemented
8,001 - 16,000 Very Hard Cemented Can be scratched with knife.
RELATIVE DENSITY OF COARSE-GRAINED SOILS: Poorly Can be broken apart easily with fingers.
N-Blows/ft Relative Density Cemented
0-3 Very Loose
4-9 Loose •
10-29 Medium Dense
30-49 Dense EEC
50-80 tr Dense
80+ Extremely Dense
UNIHED SOIL CLASSIFICATION SYSTEM
Soil Classification
Group
Criteria for Assigning Group Symbols and Group names Using Laboratory Tests Symbol bol Group Name
Coarse—Grained Gravels more than Clean Grovels Less
Soils more than 50% of coarse than 5% fines Cu>_4 and <Cc53[ GW Well—graded grovel'
50% retained on fraction retained _ _
' No. 200 sieve on No. 4 sieve Cu C4 and/or 1>Cc>31 GP Poorly—graded gravel'
Gravels with Fines Fines classify as ML or MH GM Silty gravel, G,H
more than 12%
• fines Fines classify as CL or CH GC Clayey Grovel'`•"
Sands 50% or Clean Sands Less Cut¢ and 1<G.c≤3e SW Well—graded sand'
more coarse than 5% fines
fraction passes Cu<6 and/or 1>Cc>3e SP Poorly—graded sand'
No. 4 sieve
Sands with Fines Fines classify as ML or MH SM Silty sand'
more than 12%
fines Fines classify as CL or CH SC Clayey sand°"'
Fine—Grained Slits and Clays inorganic PI>7 and plots on or above "A"Line' CL Lean clay'r."
Sails 50% or Liquid Limit less
more passes the than 50 PI<4 or plots below 'A-Line ML Silt"'
No. 200 sieve
organic Liquid Limit — oven dried Organic clay WO
<0.75 OL
Liquid Limit — not dried Organic silt"
Silts and Clays inorganic P1 plots on or above "A"Line CH Fat clay°
Liquid Limit 50 or
more P1 plots below "A"Line MH Elastic Silt`j".
organic Liquid Limit oven dried Organic clay'
<0.75 OH
Liquid Limit — not dried Organic silt'
Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat
ABosed on the material passing the 3-in. (75- r (l), If sot contains 15 to 29 lus No. 200. add
mm) sieve CU�Oa/0,Cc= 0 % D 'with sand" or 'with gravel whichever Is
elf field sample contained cobbles or boulders, predominant,
or both, odd 'with cobbles or boulders, or both' tlf sot contains 2 30' plus No. 200
to group nam& hf sat contains 2t5X sand, add'wlUt•sond"to predominantly sand. odd 'sandy to group
cCrovcls with 5 to 12X fines required dual home.
symtidar. group nave "If sot contains 2 JOX plus No. 200
GW-GM well graded gravel with sit %f fines classify as CL 44 use dual symbol GC-LM pred°minonUy gravel, odd "gravely' to group
GW-GC well-graded grovel with day , or SC-SY.
'1f fines ore organic, add'wlth organic Mee'to name.
OP-CM poorly-graded gravel wlth slit group erne °P124 and plots on or above 'A' ans.
GP-GC poorly-graded gravel with day of sail contains �J5xgravel, add"with ravel' °PlS4 or plots below 'A' line.
Sands with 5 to 12X fines require dual to group name. 9 °Pl plots on ar above A" line
symbols: f °PI plots below 'A' line.
SW-SM well-graded sand with sit If Atterberg limits plots shaded area, sal is a
SW-SC well-graded sand with clay Cl..-14L, cat),day.
SP-SM poorly graded sand with slit
SP-SC poorly graded sand with day
•
'a
•rat aoadflootbn of llnd freedomo-g olood sots '
and Sno-snnlnsdon of ammo- e
c obid sons. i
50
[quota,of'A'-nr8 /
r tbrlaonld at N.4 to IL..ae n 4.5r•
`
Nan A-473(LL-20) ", ' r
t'awtlan e1 V—M. +air O
40 Yvlkd et Il.I5 to PI-7,
W then Plans(LL-el .
i
G
JO
i .
I- ,l,
U
F i Q�VI 30
•G�• d� MH °I1 OH
ic
• la ,
ML in OL
E r
,
00 la 30 ]a .O Sa f0 70 s0 i0 100 110
L14UI0 LIMIT (LL)
LEGEND
r-- ISITE PHOTO
8-2 BORING LOCATION
N MOTOR TAKEN FROM APPROXIMATE LOCATION, IN OOIECTION OF ARROW
NOT TO SCALE
EXISTING CORRAL
PROPOSED SEPTIC AREA
PERC AREA TEST RESULTS 1-----:I •a ♦�
O I--664 MiWINQI * B-1
O 2-- 62.5 404/1404
O 3-- 33.9 MD1/1N04 l *4 -*3 *4 I
R 4-- 71.4 NIWINCH
O 5-- 33.3 FOIL/INCH
O 6-- 00.0 NIN/INCH
AVERAGE—03.8 rownln, .� PROPOSPEQNDETENTION
PROPOSED PARKING v
SITE DRAINAGE
`X 7 F
mz 1---i L_ — B 4 — --1 I / 1 c)
o
1r I B-2• 0
o c
xi
l Iz
DLI PROPOSED EVENT CENTER \ / XI
0
-< I4 ,� D
. - -\ _ W
B--5 / B-3 W
PROPOSED DRIVEWAY (T;3
J \. J
WELD COUNTY ROAD 70
-\ r_____
BORING LOCATION DIAGRAM
GATEWAY EVENTS CENTER
WELD COUNTY, COLORADO
PROJECT NO: 1052126 DATE: SEPTEMBER 2005
EARTH ENGINEERING CONSULTANTS
.11 m+e,. . r n -i
1L 4 Fu ^ x ^ds'n w: gx�� t
•.' fk' PHOTO # 1
yy P
id lF Y V
rr �y{P�Y c, 41.
� tlF 4 f 1
_. .. ,.r 1'I i iia�i{I) .m."Fm` _ y
PHOTO # 2
GATEWAY EVENTS CENTER
WELD COUNTY,COLORADO
EEC PROJECT No. 1052126 `/'�_
SEPTEMBER 2005 EE v
GATEWAY EVENTS CENTER
WELD COUNTY,COLORADO
PROJECT NO: 1052128 PERC TEST PROFILE HOLE DATE: SEPTEMBER 2005
LOG OF BORING B-1
RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JJB START DATE 8/31/2005 WHILE DRILLING 8.5'
AUGER TYPE: 4"CFA FINISH DATE 8/31/2005 AFTER DRILLING T,a
SPT HAMMER: MANUAL SURFACE ELEV N/A 24 HOUR N/A
SOIL DESCRIPTION D N OU MC OD 5-LIMITS -200 SWELL
._ TYPE (FEET) (BLOWS6T1 (PSF) 1X 1 IPCFI LL PI (%) PRESSURE %R 100 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY(CL) —
brown 2
soft
3
_4_
_S
6
SILTY SANDY LEAN CLAY(CL) 7
tan
soft -a
BOTTOM OF BORING 8.0' _ _
9
10
1-1
12
1-3
1-4
15
16
1-7
1-8
19
20
2-1
2-2
2-3
1-4
25
Earth Engineering Consultants
GATEWAY EVENTS CENTER
WELD COUNTY,COLORADO
PROJECT NO: 1052126 DETENTION POND(PIEZOMETER) DATE: SEPTEMBER 2005
RIG TYPE: CME45 LOG OF BORING 5-2
SHEET 1 OF 1 WATER DEPTH
FOREMAN: JJB START DATE 8/31/2005 WHILE DRILLING 6.0'
AUGER TYPE: 4"CFA FINISH DATE 8/31/2005 AFTER DRILLING N/A --
SPT HAMMER: MANUAL SURFACE ELEV N/A 24 HOUR 8.2'
SOIL DESCRIPTION 0 N DU MC DD ALIMITS -200 SWELL
TYPE (FEET) (BLOWS/FT) (PEF) (%) (PCP) LL PI
1%) PRESSURE % 160//SF
TOPSOIL AND VEGETATION
_i_
SANDY LEAN CLAY(CL) _ _
brown 2
soft
-3
4
SS -5 2 <500 24.8
6
_7_
8
9
reddish brown color change with depth _
SS 10 4 <500 22.5
1-1
1-2
13
1-4
SANDSTONE BEDROCK
rust/brown SS 1-5 26 0000 17.8
poorly cemented —
BOTTOM OF BORING 15.5' 1-6
1-7
1-8
1-9
2-0
2-1
2-2
2-3
2-4
25
Earth Engineering Consultants
GATEWAY EVENTS CENTER
WELD COUNTY,COLORADO
PROJECT NO: 1052126 DATE: SEPTEMBER 2005
,.-.. LOG OF BORING 5.3
RIG TYPE: CME45 SHEET 1 OF 1
WATER DEPTH
FOREMAN: JJB START DATE 5/31/2005 WHILE DRILLING None
AUGER TYPE: 4"CFA FINISH DATE 5/31/2005 AFTER DRILLING None
SPT HAMMER: MANUAL SURFACE ELEV N/A 24 HOUR N/A
SOIL DESCRIPTION 0 N OU MC 90 A-LIMITS -200 SWELL
J TYPE (FEET) (BLOWSIFTI (PSPI MI (PCF) LL PI
A4I PRESSURE %fg IW PSF
TOPSOIL AND VEGETATION
_1_
SANDY LEAN CLAY(CL) — —
brown 2
stiff to very stiff ST _ _ — 5000 9.2 37 21 57.4 3000 3.1%
3
5S _ _ 3 9000+ 12.7
4
5
6
_ _
7
_9_
SS 1-0 6 2000 22.1
SANDSTONE BEDROCK 1-1
rust/gray
poorly cemented 1-2
Firmed at 13.0' 1-3
1-4
Scattered Claystone seams with depth — —
SS 15 30 9000+ 23.8
BOTTOM OF BORING 15.5' 1-6
17
18
1-9
2-0
2-1
22
23
2-4
2-5
Earth Engineering Consultants
GATEWAY EVENTS CENTER
WELD COUNTY,COLORADO
PROJECT NO: 1052126 DATE: SEPTEMBER 2006
LOG OF BORING Bd
RIG TYPE: CME46 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JJB START DATE 8/3112005 WHILE DRILLING None
AUGER TYPE: 4"CFA FINISH DATE 6/31/2005 AFTER DRILLING None
SPT HAMMER: MANUAL SURFACEELEV N/A 24 HOUR N/A
SOIL DESCRIPTION O N 0U MC 00 A-LIMITS -200 SWELL
_ TYPE (FEET) (BLOWS/FT) IPSF) (%) (PCFI LL PI I%I PRESSURE %ES 150 pa
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY(CL) _ _
brown 2
stiff
3
_4
CS 6 12 2600 8.8 89.4 31 13 62.4 0 none
_6
SILTY SANDY LEAN CLAY(CL) _ _
tan 7
soft
8
9
SS 1-0 7 500 21.9
SANDSTONE BEDROCK 1-1
..-`. gray/rust _ _
poorly cemented 12
with scattered claystone seams _ _
13
Firmed with depth
1-4
SS 1-5 18 6000 24.1
BOTTOM OF BORING 15.5' 16
1-7
1-8
1-9
2-0
2-1
2-2
2-3
24
2-6
-- Earth Engineering Consultants
SWELL / CONSOLIDATION TEST RESULTS
Material Description: BrownClay with Sand (Remold)
Sample Location: B-4, S-1, 4'
Liquid Limit: 31 (Plasticity Index: 13 i % Passing #200: 52.4
Beginning Moisture: 12.5% Dry Density: 87 pcf !Ending Moisture: 24.5%
Swell Pressure: 0 psf % Swell @ 500 psf: 0.0%
10 - 1 I _1
F"
8 --- l- _ __11—. ; _ - -
I I
06 —
3
w I
q
i
c 2
P,
E
O
0 —
P /
Pi: St r ded 0- 2
0-4 _ _
CO
•a
c-6
OIIU
-8 i
-10 -- L-1J---. i I I ; J
0.01 0.1 1 10
Load (TSF)
Project: Gateway Event Center
Eaton, Colorado
Project#: 1052126
Date: September 2005
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Clay with Sand
Sample Location: 8-5, S-1, 2'
Liquid Limit: 33 'Plasticity Index: 16 I % Passing #200: 75.4
Beginning Moisture: 16.4% Dry Density: 105.7 pcf I Ending Moisture: 18.9%
Swell Pressure: 0 psf % Swell @ 500 psf: 0.1%
10
I
6
36 -
4 __ _
2
E
d
0
d
to dded
0-4 ,-
U i
6
-10
0.01 0.1 1 10
Load (TSF)
Project: Gateway Event Center
Eaton, Colorado
Project#: 1052126
Date: September 2005
E ECY
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