Geotechnical Engineering Report - Pavilion … Hermosa...Geotechnical Engineering Report Richardson...
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Geotechnical Engineering Report
Richardson Subdivision Apartments
37th Street and Grand Avenue
Artesia, New Mexico
September 13, 2011
Terracon Project No. 68115055
Prepared for:
Development Design & Engineering, Inc.
El Centro, California
Prepared by:
Terracon Consultants, Inc.
Las Cruces, New Mexico
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY ....................................................................................................... i
1.0 INTRODUCTION ...................................................................................................... 1
2.0 PROJECT INFORMATION ....................................................................................... 1
2.1 Project Description ........................................................................................ 1
2.2 Site Location and Description ........................................................................ 2
3.0 SUBSURFACE CONDITIONS.................................................................................. 3
3.1 Typical Subsurface Profile ............................................................................. 3
3.2 Groundwater ................................................................................................. 3
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION ............................... 3
4.1 Geotechnical Considerations......................................................................... 3
4.2 Earthwork ...................................................................................................... 4
4.2.1 Site Preparation ................................................................................. 4
4.2.2 Excavation ......................................................................................... 5
4.2.3 Subgrade Preparation ........................................................................ 5
4.2.4 Fill Materials and Placement .............................................................. 6
4.2.5 Compaction Requirements................................................................. 7
4.2.6 Grading and Drainage ........................................................................ 7
4.2.7 Corrosion Potential ............................................................................ 7
4.3 Foundation Recommendations ...................................................................... 8
4.3.1 Design Recommendations ................................................................. 8
4.3.2 Construction Considerations .............................................................. 9
4.4 Seismic Considerations ................................................................................. 9
4.5 Floor Slabs ...................................................................................................10
4.5.1 Design Recommendations ................................................................10
4.5.2 Construction Considerations .............................................................10
4.6 Pavements ...................................................................................................10
5.0 GENERAL COMMENTS .........................................................................................13
Exhibit No.
Appendix A – Field Exploration
Site Location Map and Boring Location Plan............................................. A-1 and A-2
Field Exploration Description ................................................................................. A-3
Boring Logs ............................................................................................ A-4 thru A-11
General Notes ..................................................................................................... A-12
Unified Soil Classification System ........................................................................ A-13
Appendix B – Laboratory Testing
Laboratory Test Description ................................................................................... B-1
Laboratory Test Results ............................................................................ B-2 thru B-6
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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EXECUTIVE SUMMARY
This geotechnical executive summary should be used in conjunction with the entire report
for design and/or construction purposes. It should be recognized that specific details were not
included or fully developed in this section, and the report must be read in its entirety for a
comprehensive understanding of the items contained herein. The section titled General
Comments should be read for an understanding of the report limitations.
A geotechnical exploration has been performed for the Richardson Subdivision Apartments
located near the northeast corner of 37th Street and Grand Avenue in Artesia, New Mexico.
The proposed project will include a residential subdivision (approximately 3.5 acres) with a
government controlled 80 unit multi-family apartment complex (10 structures with a community
services building). Paved parking and drive areas are also associated with the project.
Terracon’s geotechnical scope of work included the advancement of eight (8) test borings to
approximate depths ranging from 11-1/2 to 21-1/2 feet below existing site grades (bgs).
Based on the information obtained from our subsurface exploration, the site is suitable for
development of the proposed project. The following geotechnical considerations were
identified:
The site soils in the building areas generally consisted of compressible and expansive
lean clay with varying amounts of sand from the surface to the total explored depths (11-
1/2 to 21-1/2 feet bgs). Groundwater was not encountered in the test borings at the time
of drilling.
Due to the presence of compressible and expansive soils on the site, standard spread
and continuous footings bearing on a minimum of 3 feet of engineered fill may be used
for support of the structures. The majority of on-site clay soils do not appear suitable for
use as engineered fill beneath foundations and floor slabs. However, on-site clay soils
may be blended with imported granular soils to meet the engineered fill specification
contained in this report.
Standard spread and continuous foundations are used for support of the structures,
construction of floor slabs on a minimum thickness of 3 feet of engineered fill composed
of approved blended on-site or imported soils is considered acceptable for the project.
Automobile parking areas – 3” AC over 6” ABC over 10” Compacted Subgrade. 35th
Street – 4-1/2” AC over 6” ABC over 10” Compacted Subgrade
Earthwork on the project should be observed and evaluated by Terracon. The evaluation
of earthwork should include observation and testing of engineered fill, subgrade
preparation, foundation bearing soils, and other geotechnical conditions exposed during
construction
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GEOTECHNICAL ENGINEERING REPORT
RICHARDSON SUBDIVISION APARTMENTS
NEC OF 37TH STREET AND GRAND AVENUE
ARTESIA, NEW MEXICO Terracon Project No. 68115055
September 13, 2011
1.0 INTRODUCTION
This report presents the results of our geotechnical engineering services performed for the
Richardson Subdivision Apartments located near the northeast corner of 37th Street and Grand
Avenue in Artesia, New Mexico. The proposed project will include a residential subdivision
(approximately 3.5 acres) with a government controlled 80 unit multi-family apartment complex
(10 structures with a community services building). Paved parking and drive areas are also
associated with the project. Items addressed in this report are as follows:
subsurface soil conditions groundwater conditions
earthwork foundation design and construction
seismic considerations floor slab design and construction
pavements
Our geotechnical engineering scope of work for this project included the advancement of eight
test borings to depths ranging from approximately 11-1/2 to 21-1/2 feet below existing site
grades.
Logs of the borings along with a Site Location Map and Boring Location Plan (Exhibits A-1 and A-
2) are included in Appendix A of this report. The results of the laboratory testing performed on
soil samples obtained from the site during the field exploration are included in Appendix B of this
report. Descriptions of the field exploration and laboratory testing are included in their respective
appendices.
2.0 PROJECT INFORMATION
2.1 Project Description
ITEM DESCRIPTION
Site layout Refer to the Site Location Map and Boring Location Plan (Exhibits
A-1 and A-2)
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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ITEM DESCRIPTION
Structures
The proposed project will include a residential subdivision
(approximately 3.5 acres) with a government controlled 80 unit
multi-family apartment complex (10 structures with a community
services building). The buildings will be single-story and two-story
structures. Paved parking and roadway areas (portion of 35th
Street) are associated with the project.
Building construction
The buildings will consist of wood frame bearing on exterior and
interior spot footings. The floor system is anticipated to be slab-on-
grade.
Finished floor elevation Existing
Maximum loads
Columns: 15 to 40 kips maximum (assumed)
Walls: 2.0 klf maximum (assumed)
Slabs: 150 psf max (assumed)
Maximum allowable movement 1 inch
Maximum allowable differential
movement
½ inch over 40 feet for walls, ¾ inch over 40 feet for interior
columns (assumed)
Grading in building area Minimal cuts and fills are anticipated
Retaining walls None
Cut and fill slopes None
2.2 Site Location and Description
ITEM DESCRIPTION
Location Northeast of 37th Street and Grand Avenue in Artesia, New Mexico
Existing site features Vacant lot. Evidence of previous development was not observed
during the field exploration
Surrounding developments
North: Single Family Residential
East: Undeveloped
West: 37th Street
South: Single Family Residential
Current ground cover Subgrade soils sparsely vegetated with native grasses and
mesquite bush. Construction debris piles were located throughout
the site.
Existing topography Relatively flat
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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3.0 SUBSURFACE CONDITIONS
3.1 Typical Subsurface Profile
Specific conditions encountered at the boring locations are indicated on the individual boring
logs. Stratification boundaries on the boring logs represent the approximate location of
changes in soil types; in-situ, the transition between materials may be gradual. Details for each
of the borings can be found on the boring logs included in Appendix A of this report. Based on
the results of the borings, subsurface conditions on the project site can be generalized as
follows:
Description Approximate Depth to
Bottom of Stratum (feet) Material Encountered Consistency/Density
Stratum 1 11-1/2 to 21-1/2
Lean Clay with varying
amounts of gravel, sand
and carbonate cementation
Stiff to Hard
Laboratory tests were conducted on selected soil samples and the test results are presented
in Appendix B. The soil samples tested have a slight to significant tendency for hydro-
compaction when elevated in moisture content. It is likely that some sample disturbance
occurred due to the high blow counts and low moisture contents of tested samples. It is our
opinion that the soils will exhibit low to moderate compression potential and low to moderate
expansive potentials.
3.2 Groundwater
Groundwater was not observed in the test borings at the time of field exploration. These
observations represent groundwater conditions at the time of the field exploration and may
not be indicative of other times, or at other locations. Groundwater conditions can change
with varying seasonal and weather conditions, and other factors.
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION
4.1 Geotechnical Considerations
Due to the presence of compressible/expansive soils and based on the geotechnical
engineering analyses, subsurface exploration and laboratory test results, Terracon
recommends that the proposed structures be supported by standard spread and continuous
footings bearing on a minimum thickness of 3 feet of engineered fill.
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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Low to moderate expansive soils are present on this site. This report provides
recommendations to help mitigate the effects of soil shrinkage and expansion. However,
even if these procedures are followed, some movement and (at least minor) cracking in the
structures should be anticipated. The severity of cracking and other cosmetic damage such
as uneven floor slabs will probably increase if any modification of the site results in
excessive wetting or drying of the expansive soils. Eliminating the risk of movement and
cosmetic distress may not be feasible, but it may be possible to further reduce the risk of
movement if significantly more expensive measures are used during construction which may
include additional engineered fill thicknesses and/or structural slabs. We would be pleased
to discuss other construction alternatives with you upon request.
Geotechnical engineering recommendations for foundation systems and other earth
connected phases of the project are outlined below. The recommendations contained in this
report are based upon the results of field and laboratory testing (which are presented in
Appendices A and B), engineering analyses, and our current understanding of the proposed
project.
4.2 Earthwork
The following presents recommendations for site preparation, excavation, subgrade
preparation and placement of engineered fills on the project. The recommendations
presented for design and construction of earth supported elements including foundations
and slabs are contingent upon following the recommendations outlined in this section. All
grading for the structures should incorporate the limits of the proposed structures plus a
minimum pad blow-up of five feet beyond proposed perimeter building walls (where
applicable).
Earthwork on the project should be observed and evaluated by Terracon. The evaluation of
earthwork should include observation and testing of engineered fill, subgrade preparation,
foundation bearing soils, and other geotechnical conditions exposed during the construction
of the project.
4.2.1 Site Preparation
Strip and remove existing vegetation, construction piles, surface debris and other
deleterious materials from proposed building area. Exposed surfaces should be free of
mounds and depressions which could prevent uniform compaction.
Stripped materials consisting of vegetation and organic materials should be wasted from the
site, or used to revegetate landscaped areas or exposed slopes after completion of grading
operations. If it is necessary to dispose of organic materials on-site, they should be placed
in non-structural areas, and in fill sections not exceeding 5 feet in height.
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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The site should be initially graded to create a relatively level surface to receive fill, and to
provide for a relatively uniform thickness of fill beneath the proposed building structures.
Although evidence of underground facilities such as septic tanks, cesspools, utilities and
basements was not observed during the site reconnaissance, such features could be
encountered during construction. If unexpected fills or underground facilities are
encountered, such features should be removed and the excavation thoroughly cleaned prior
to backfill placement and/or construction.
4.2.2 Excavation
It is anticipated that excavations for the proposed construction can be accomplished with
conventional earthmoving equipment.
On-site soils may pump or become unstable or unworkable at high water contents.
Workability may be improved by scarifying and drying. Overexcavation of wet zones and
replacement with granular materials may be necessary. Lightweight excavation equipment
may be required to reduce subgrade pumping.
4.2.3 Subgrade Preparation
A minimum of 3 feet of engineered fill is recommended below spread and continuous
foundations and a minimum of 2 feet of engineered fill is recommended beyond the lateral
extents of the foundations. The engineered fill should extend laterally an additional distance
of 8 inches for each additional foot of excavation beyond the 3-foot minimum depth.
Additionally, the engineered fill should extend horizontally a minimum distance of 5 feet
beyond the outside edge of the slab perimeter. The majority of clean on-site soils do not
appear suitable for use as engineered fill at this site. Site soils (clays) that do not meet the
engineered fill specifications can be blended with imported granular soils to achieve the
recommended fill parameters provided in this report. Additional effort will be required by the
earthwork contractor to moisture condition and blend the on-site clay soils with imported
soils for use as engineered fill.
Exposed areas which will receive fill, once properly cleared and benched where necessary,
should be scarified to a minimum depth of ten inches, conditioned to near optimum moisture
content, and compacted.
Areas of loose or soft soils may be encountered at foundation bearing depth after
excavation is completed for footings. When such conditions exist beneath planned footing
areas, the subgrade soils should be surficially compacted prior to placement of the
foundation system. If sufficient compaction can not be achieved in-place, the loose soils
should be removed and replaced as engineered fill. For placement of engineered fill below
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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footings, the excavation should be widened laterally, at least eight inches for each foot of fill
placed below footing base elevations.
Subgrade soils beneath exterior slabs should be scarified, moisture conditioned and
compacted to a minimum depth of 10 inches. The moisture content and compaction of
subgrade soils should be maintained until slab or pavement construction.
4.2.4 Fill Materials and Placement
All fill materials should be inorganic soils free of vegetation, debris, and fragments larger
than six inches in size. Pea gravel or other similar non-cementitious, poorly-graded
materials should not be used as fill or backfill without the prior approval of the geotechnical
engineer.
Approved imported materials or blended soils may be used as fill material for the following:
general site grading exterior slab areas
foundation areas foundation backfill
pavement areas
Imported or blended soils for use as fill material within proposed building areas should
conform to low volume change materials as indicated in the following specifications:
Percent Finer by Weight
Gradation (ASTM C 136)
6" ......................................................................................................... 100
3” .................................................................................................... 70-100
No. 4 Sieve ..................................................................................... 50-100
No. 200 Sieve ................................................................................... 25-75
Liquid Limit ....................................................................... 35 (max)
Plasticity Index .................................................................. 15 (max)
Maximum expansive potential (%)* ............................................ 1.0
*Measured on a sample compacted to approximately 95 percent of the ASTM D698
maximum dry density at about 3 percent below optimum water content. The sample
is confined under a 100 psf surcharge and submerged/inundated.
Engineered fill should be placed and compacted in horizontal lifts, using equipment and
procedures that will produce recommended moisture contents and densities throughout the
lift. Fill lifts should not exceed ten inches loose thickness.
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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4.2.5 Compaction Requirements
Recommended compaction and moisture content criteria for engineered fill materials are as
follows:
Material Type and Location
Per the Modified Proctor Test (ASTM D 1557)
Minimum
Compaction
Requirement (%)
Range of Moisture Contents
for Compaction
Minimum Maximum
Approved on-site or imported fill soils:
Beneath foundations: 95 0% +3%
Beneath slabs: 95 0% +3%
Beneath pavements: 95 0% +3%
Miscellaneous backfill 90 0% +3%
4.2.6 Grading and Drainage
Positive drainage should be provided during construction and maintained throughout the life
of the project. Infiltration of water into utility trenches or foundation excavations should be
prevented during construction. Planters and other surface features which could retain water
in areas adjacent to the buildings should be sealed or eliminated. In areas where sidewalks
or paving do not immediately adjoin the structures, we recommend that protective slopes be
provided with a minimum grade of approximately 5 percent for at least 10 feet from
perimeter walls. Backfill against footings, exterior walls, and in utility and sprinkler line
trenches should be well compacted and free of all construction debris to reduce the
possibility of moisture infiltration.
Downspouts, roof drains or scuppers should discharge into splash blocks or extensions
when the ground surface beneath such features is not protected by exterior slabs or paving.
Sprinkler systems should not be installed within five feet of foundation walls. Landscaped
irrigation adjacent to the foundation systems should be minimized or eliminated.
4.2.7 Corrosion Potential
Soluble sulfate testing from the general area indicates that ASTM Type I Portland cement is
suitable for all concrete on and below grade. However, the use of ASTM Type II Portland
cement is recommended for additional sulfate resistance of construction concrete based on
the published information. Foundation concrete should be designed in accordance with the
provisions of the ACI Design Manual, Section 318, Chapter 4.
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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4.3 Foundation Recommendations
The building structures can be supported by spread footings bearing on engineered fill.
Design recommendations for foundations for the proposed structures and related structural
elements are presented in the following paragraphs.
4.3.1 Design Recommendations
DESCRIPTION VALUE
Foundation Type Spread and Continuous Footings
Structures
The proposed project will include a residential
subdivision (approximately 3.5 acres) with a
government controlled 80 unit multi-family apartment
complex (10 structures with a community services
building). The buildings will be single-story and two-
story structures.
Bearing Material Minimum 3-foot thickness of engineered fill for support
of spread footings and continuous footings.
Allowable Bearing Pressure 2,000 psf
Minimum Embedment Depth Below
Finished Grade 18 inches
Total Estimated Movement 1 inch
Estimated Differential Movement ½ inch in 40 feet under walls
Finished grade is defined as the lowest adjacent grade within five feet of the foundation for
perimeter (or exterior) footings and finished floor level for interior footings. The allowable
foundation bearing pressures apply to dead loads plus design live load conditions. The
design bearing pressure may be increased by one-third when considering total loads that
include wind or seismic conditions. The weight of the foundation concrete below grade may
be neglected in dead load computations.
Exterior footings should be placed a minimum of 18 inches below finished grade to provide
confinement for the bearing soils. Finished grade is the lowest adjacent grade for perimeter
footings and floor level for interior footings.
Footings should be proportioned to reduce differential foundation movement. Proportioning
on the basis of equal total movement is recommended; however, proportioning to relative
constant dead-load pressure will also reduce differential movement between adjacent
footings. Additional foundation movements could occur if water from any source infiltrates
the foundation soils; therefore, proper drainage must be provided in the final design and
during construction.
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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Footings, foundations, and masonry walls should be reinforced as necessary to reduce the
potential for distress caused by differential foundation movement. The use of joints at
openings or other discontinuities in masonry walls is recommended.
Foundation excavations and engineered fill placement should be observed by the
geotechnical engineer. If the soil conditions encountered differ significantly from those
presented in this report, supplemental recommendations will be required.
4.3.2 Construction Considerations
A minimum of three feet of engineered fill is recommended below all footings. The subgrade
soils should be removed to a minimum depth of 36 inches and a minimum of 24 inches
horizontally beyond the edge of footings. The engineered fill should extend laterally an
additional distance of 8 inches for each additional foot of excavation beyond the 36-inch
minimum depth. The soils should be replaced with approved engineered fill, conditioned to
near optimum moisture content and compacted.
4.4 Seismic Considerations
We have provided seismic design parameters according to the 2009 International Building
Code (IBC) for design and construction of the proposed structure. Selected site ground
motion parameters for the project have been determined in general accordance with the
IBC. The values provided are based on the subsurface exploration presented herein and
the USGS software for use in interpolating values.
CONTERMINOUS 48 STATES-2003 NEHRP SEISMIC DESIGN PROVISIONS
LATITUDE: 32.839 LONGITUDE: -104.441
Spectral Response Accelerations SMs and SM1 SMs = FaSs and SM1 = FvS1
Site Class D - Fa = 1.6, Fv = 2.4
Period (sec) Sa (g)
0.2 0.250 (SMs, Site Class D)
1.0 0.109 (SM1, Site Class D)
SDs = 2/3 x SMs and SD1 = 2/3 x SM1
Site Class D - Fa = 1.6 ,Fv = 2.4
Period (sec) Sa (g)
0.2 0.166 (SDs, Site Class D)
1.0 0.073 (SD1, Site Class D)
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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4.5 Floor Slabs
4.5.1 Design Recommendations
DESCRIPTION VALUE
Interior floor system Slab-on-grade concrete.
Floor slab support 3 feet of engineered fill soils placed and compacted in
accordance with Earthwork section of this report.
Modulus of subgrade reaction 100 pounds per square inch per inch (psi/in)
Construction of floor slabs compacted fills composed of approved soils is considered
acceptable for the project.
In areas of exposed concrete, control joints should be saw cut into the slab after concrete
placement in accordance with ACI Design Manual, Section 302.1R-37 8.3.12 (tooled control
joints are not recommended). Additionally, dowels should be placed at the location of
proposed construction joints. To control the width of cracking (should it occur) continuous
slab reinforcement should be considered in exposed concrete slabs.
Positive separations and/or isolation joints should be provided between slabs and all
foundations, columns or utility lines to allow independent movement. Interior trench backfill
placed beneath slabs should be compacted in accordance with recommendations outlined in
the Earthwork section of this report. Other design and construction considerations, as
outlined in the ACI Design Manual, Section 302.1R are recommended.
4.5.2 Construction Considerations
A minimum of 3 feet of engineered fill is recommended below slabs-on-grade. The
engineered fill should extend horizontally a minimum distance of 5 feet beyond the outside
edge of perimeter footings. Some differential movement of a slab-on-grade floor system is
possible should the subgrade soils become elevated in moisture content. Such movements
are anticipated to be within general tolerance for normal slab-on-grade construction. To
reduce potential slab movements, the subgrade soils should be prepared as outlined in the
Earthwork section of this report.
4.6 Pavements
Design of parking and drive pavements for the project has been based on the procedures
outlined in the 1990 Flexible Pavement Design – California Design Procedures. Assumed
traffic criteria used for pavement thickness design includes single 18-kip equivalent standard
axle loads (ESAL's) of 36,000 for planned auto parking areas. A Traffic Index (TI) of 5.0 for
auto areas was calculated. Actual design traffic loading should be verified. Reevaluation of
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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the recommended pavement sections may be necessary if the actual traffic varies from the
assumed criteria outlined above.
Recommended alternatives for flexible and rigid pavements are as follows:
Traffic Area Alternative
Recommended Pavement Section Thickness (inches)
Asphalt
Concrete
Surface
Portland
Cement
Concrete
Aggregate
Base
Course
Total
Parking and Drive
Areas
A --- 5 --- 5
B 3 --- 6 9
New pavement thicknesses for 35th Street developed for the project have been based on the
procedures outlined in the Infrastructure Design Directive IDD-2008-05 by the New Mexico
Department of Transportation (NMDOT). Estimated traffic criteria used for pavement thickness
design of each residential roadway includes single 18-kip equivalent standard axle loads
(ESAL's) of 150,000. Actual design traffic loading should be verified. Reevaluation of the
recommended pavement sections may be necessary if the actual traffic varies from the
assumed criteria outlined above.
Based upon AASHTO criteria, New Mexico is located within Climatic Region V of the United
States. This region is characterized as being dry, with freeze-thaw cycling. For design
purposes, these conditions typically result in saturated or near-saturated subgrade soil
moisture conditions for approximately 4 percent of the annual moisture variation cycle.
For flexible pavement design of the roadway alignment, a terminal serviceability index of 2.0
was utilized along with an inherent reliability of 85 percent. Using the correlated design R-value
(10), appropriate EAL/day, environmental criteria and other factors, the structural numbers (SN)
of the pavement sections were determined on the basis of the 1993 AASHTO design equation.
Recommended alternatives for flexible pavements are as follows:
Traffic Area Alternative
Recommended Pavement Section Thickness (inches)
Asphalt
Concrete
Surface
Portland
Cement
Concrete
Aggregate
Base
Course
Total
35th Street A 4-1/2 --- 6 10-1/2
B --- 6 --- 6
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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Each alternative should be investigated with respect to current material availability and
economic conditions. Rigid concrete pavement, a minimum of 6 inches in thickness, is
recommended at the location of dumpsters where trash trucks will park and load or areas of
anticipated heavy vehicle loads.
Minimizing subgrade saturation is an important factor in maintaining subgrade strength and
stability. Some distress of pavements is possible due to the clay subgrade soils. Water
allowed to pond on or adjacent to pavements could saturate the subgrade and cause
premature pavement deterioration. The pavement should be sloped to provide rapid surface
drainage, and positive surface drainage should be maintained away from the edge of the
paved areas. Design alternatives which could reduce the risk of subgrade saturation and
improve long-term pavement performance include crowning the pavement subgrades to
drain toward the edges, rather than to the center of the pavement areas; and installing
surface drains next to any areas where surface water could pond. Properly designed and
constructed subsurface drainage will reduce the time subgrade soils are saturated and can
also improve subgrade strength and performance.
Periodic maintenance extends the service life of the pavement and should include crack
sealing, surface sealing and patching of any deteriorated areas. Also, thicker pavement
sections could be used to reduce the required maintenance and extend the service life of
the pavement. If asphaltic concrete is used for this project, we recommend that reinforced
concrete pads be provided in front of and beneath trash receptacles or other areas
anticipated to support heavy vehicle traffic loads. The dumpster trucks should be parked on
the rigid concrete pavement when the trash receptacles are lifted. The concrete pads at and
adjacent to the trash enclosure should be a minimum of 6 inches thick and properly
reinforced.
The performance of all pavements can be enhanced by minimizing excess moisture which
can reach the subgrade soils. The following recommendations should be considered at
minimum:
site grading at a minimum 2 percent grade away from the pavements.
the subgrade and the pavement surface have a minimum 1/4 inch per foot slope to
promote proper surface drainage.
consider appropriate edge drainage and pavement underdrain systems.
install pavement drainage surrounding areas anticipated for frequent wetting (e.g.,
garden centers, wash racks).
install joint sealant and seal cracks immediately.
compaction of any utility trenches for landscaped areas to the same criteria as the
pavement subgrade.
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
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seal all landscaped areas in or adjacent to pavements to minimize or prevent
moisture migration to subgrade soils.
place compacted, low permeability backfill against the exterior side of curb and
gutter.
place curb, gutter and/or sidewalk directly on subgrade soils without the use of base
course materials.
5.0 GENERAL COMMENTS
Terracon should be retained to review the final design plans and specifications so
comments can be made regarding interpretation and implementation of our geotechnical
recommendations in the design and specifications. Terracon also should be retained to
provide observation and testing services during grading, excavation, foundation construction
and other earth-related construction phases of the project.
The analysis and recommendations presented in this report are based upon the data
obtained from the borings performed at the indicated locations and from other information
discussed in this report. This report does not reflect variations that may occur between
borings, across the site, or due to the modifying effects of construction or weather. The
nature and extent of such variations may not become evident until during or after
construction. If variations appear, we should be immediately notified so that further
evaluation and supplemental recommendations can be provided.
The scope of services for this project does not include either specifically or by implication
any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or
identification or prevention of pollutants, hazardous materials or conditions. If the owner is
concerned about the potential for such contamination or pollution, other studies should be
undertaken.
This report has been prepared for the exclusive use of our client for specific application to
the project discussed and has been prepared in accordance with generally accepted
geotechnical engineering practices. No warranties, either express or implied, are intended
or made. Site safety, excavation support, and dewatering requirements are the
responsibility of others. In the event that 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 Terracon reviews the changes
and either verifies or modifies the conclusions of this report in writing.
APPENDIX A
FIELD EXPLORATION
RICHARDSON APARTMENTS 37
TH STREET AND GRAND AVENUE
ARTESIA, NEW MEXICO
SITE LOCATION MAP
Project Mngr: DC
Drawn By:
Checked By:
Approved By:
JM
MEW
MEW
Project No. 68115055
Scale
File No.
Date:
Not to scale
Site Vicinity
08/30/11
1640 Hickory Loop, Suite 105
Las Cruces, New Mexico 88005
575.527.1700 Fax: 575.527.1092
FIG No.
A-1
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES.
Source: USGS 7.5 Minute Topographic Map “Artesia, New Mexico” 1985
N
GRAND AVENUE
PROJECT LOCATION
37th
STREET
Approximate Boring Location
RICHARDSON APARTMENTS 37
TH STREET AND GRAND AVENUE
ARTESIA, NEW MEXICO
BORING LOCATION PLAN
Project Mngr: DC
Drawn By:
Checked By:
Approved By:
JM
MEW
MEW
Project No. 68115055
Scale
File No.
Date:
Not to Scale
Boring Location
08/30/11
1640 Hickory Loop, Suite 105
Las Cruces, New Mexico 88005
575.527.1700 Fax: 575.527.1092
FIG No.
A-2
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES.
N
B-1
B-3
B-4
B-2
B-5 B-6
B-7 B-8
GRAND AVENUE
37TH
STREET
Source: Development Design & Engineering
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
Reliable ■ Responsive ■ Convenient ■ Innovative Exhibit A-3
Field Exploration Description
A total of eight (8) test borings were drilled at the site on August 16, 2011. The borings were
drilled to depths of about 11-1/2 and 21-1/2 feet below the ground surface at the
approximate locations shown on the attached Site Location Map and Boring Location Plan,
Exhibit A-1 and A-2, respectively. The test borings were located as follows:
Borings Location Depth (feet)
B-1 thru B-8 Building Footprints 11-1/2 to 21-1/2
The test borings were advanced with a truck-mounted CME-75 drill rig utilizing 8-inch
diameter hollow-stem augers.
The borings were located in the field using aerial photos, on-site property corner stakes and
using the proposed site plan. The accuracy of boring locations should only be assumed to
the level implied by the method used.
Lithologic logs of each boring were recorded by the field geologist during the drilling
operations. At selected intervals, samples of the subsurface materials were taken by driving
split-spoon or ring-barrel samplers. Bulk samples of subsurface materials were also
obtained.
Penetration resistance measurements were obtained by driving the split-spoon and ring-
barrel samplers into the subsurface materials with a 140-pound automatic hammer falling 30
inches. The penetration resistance value is a useful index in estimating the consistency or
relative density of materials encountered.
A CME automatic SPT hammer was used to advance the split-barrel sampler in the borings
performed on this site. The effect of the automatic hammer's efficiency has been
considered in the interpretation and analysis of the subsurface information for this report.
Groundwater conditions were evaluated in the borings at the time of site exploration.
- 200 =77.7%LL=31PI=135
10
15
2020.33
LEAN CLAY WITH SAND; Brown, verystiff, dry, trace gravel.
Carbonate indurated.
Trace gravel.
Stiff.
Hard, gravelly.Boring terminated at 20.33 feet. No freewater encountered at time of drilling.
SS
RB
SS
SS
SS
CL
CL
CL
CL
CL
1
2
3
4
5
17
34
18
14
50 (4")
7.0
6.4
14
12
18
14
0
87
TESTS
DESCRIPTION
RICHARDSON APARTMENTS
The stratification lines represent the approximate boundary lines
SITE
BORING STARTED
CME-55
WL
WL
WL
BORING COMPLETED
APPROVED MEW
DCFOREMANRIG
8-16-11
68115055
DEVELOPMENT DESIGN & ENGINEERINGCLIENT
LOG OF BORING NO. B-1
JOB #
GR
AP
HIC
LO
G
between soil and rock types: in-situ, the transition may be gradual.
Page 1 of 1
PROJECT
8-16-11WATER LEVEL OBSERVATIONS, ft
37TH STREET AND GRAND AVENUEARTESIA, NEW MEXICO
SAMPLES
US
CS
SY
MB
OL
WA
TE
RC
ON
TE
NT
, %
TY
PE
NU
MB
ER
5
10
15
20
DE
PT
H,
ft.
RE
CO
VE
RY
, in
.
SP
T -
NB
LOW
S \
ft.
DR
Y D
EN
SIT
Y
BO
RE
HO
LE_9
9 6
811
5055
.GP
J T
ER
RA
CO
N.G
DT
9/
13/1
1
5
10
11.5
LEAN CLAY; Light brown, stiff, carbonateindurated.
White to light brown, hard.
Brown to light brown, very stiff.
Boring terminated at 11.5 feet. No freewater encountered at time of drilling.
SS
SS
SS
CL
CL
CL
1
2
3
14
31
22
18
14
14
TESTS
DESCRIPTION
RICHARDSON APARTMENTS
The stratification lines represent the approximate boundary lines
SITE
BORING STARTED
CME-55
WL
WL
WL
BORING COMPLETED
APPROVED MEW
DCFOREMANRIG
8-16-11
68115055
DEVELOPMENT DESIGN & ENGINEERINGCLIENT
LOG OF BORING NO. B-2
JOB #
GR
AP
HIC
LO
G
between soil and rock types: in-situ, the transition may be gradual.
Page 1 of 1
PROJECT
8-16-11WATER LEVEL OBSERVATIONS, ft
37TH STREET AND GRAND AVENUEARTESIA, NEW MEXICO
SAMPLES
US
CS
SY
MB
OL
WA
TE
RC
ON
TE
NT
, %
TY
PE
NU
MB
ER
5
10
DE
PT
H,
ft.
RE
CO
VE
RY
, in
.
SP
T -
NB
LOW
S \
ft.
DR
Y D
EN
SIT
Y
BO
RE
HO
LE_9
9 6
811
5055
.GP
J T
ER
RA
CO
N.G
DT
9/
13/1
1
5
10
15
21.5
LEAN CLAY; Light brown, stiff, carbonateindurated.
Light brown to white, dry.
Very stiff.
Brown to white.
Boring terminated at 21.5 feet. No freewater encountered at time of drilling.
SS
SS
SS
SS
SS
CL
CL
CL
CL
CL
1
2
3
4
5
10
13
19
16
17
5.9
16
12
14
14
16
87
TESTS
DESCRIPTION
RICHARDSON APARTMENTS
The stratification lines represent the approximate boundary lines
SITE
BORING STARTED
CME-55
WL
WL
WL
BORING COMPLETED
APPROVED MEW
DCFOREMANRIG
8-16-11
68115055
DEVELOPMENT DESIGN & ENGINEERINGCLIENT
LOG OF BORING NO. B-3
JOB #
GR
AP
HIC
LO
G
between soil and rock types: in-situ, the transition may be gradual.
Page 1 of 1
PROJECT
8-16-11WATER LEVEL OBSERVATIONS, ft
37TH STREET AND GRAND AVENUEARTESIA, NEW MEXICO
SAMPLES
US
CS
SY
MB
OL
WA
TE
RC
ON
TE
NT
, %
TY
PE
NU
MB
ER
5
10
15
20
DE
PT
H,
ft.
RE
CO
VE
RY
, in
.
SP
T -
NB
LOW
S \
ft.
DR
Y D
EN
SIT
Y
BO
RE
HO
LE_9
9 6
811
5055
.GP
J T
ER
RA
CO
N.G
DT
9/
13/1
1
- 200 =85.6%LL=31PI=14
5
11.5
LEAN CLAY; Brown to light brown, stiff,carbonate indurated.
Very stiff, dry.
Boring terminated at 11.5 feet. No freewater encountered at time of drilling.
SS
SS
SS
CL
CL
CL
1
2
3
11
19
17
7.9
14
16
16
TESTS
DESCRIPTION
RICHARDSON APARTMENTS
The stratification lines represent the approximate boundary lines
SITE
BORING STARTED
CME-55
WL
WL
WL
BORING COMPLETED
APPROVED MEW
DCFOREMANRIG
8-16-11
68115055
DEVELOPMENT DESIGN & ENGINEERINGCLIENT
LOG OF BORING NO. B-4
JOB #
GR
AP
HIC
LO
G
between soil and rock types: in-situ, the transition may be gradual.
Page 1 of 1
PROJECT
8-16-11WATER LEVEL OBSERVATIONS, ft
37TH STREET AND GRAND AVENUEARTESIA, NEW MEXICO
SAMPLES
US
CS
SY
MB
OL
WA
TE
RC
ON
TE
NT
, %
TY
PE
NU
MB
ER
5
10
DE
PT
H,
ft.
RE
CO
VE
RY
, in
.
SP
T -
NB
LOW
S \
ft.
DR
Y D
EN
SIT
Y
BO
RE
HO
LE_9
9 6
811
5055
.GP
J T
ER
RA
CO
N.G
DT
9/
13/1
1
5
15
2020.5
LEAN CLAY; Light brown, stiff, carbonateindurated.
Very stiff ,trace gravel.
Hard.
Gravelly.Boring terminated at 20.5 feet. No freewater encountered at time of drilling.
SS
SS
SS
SS
SS
CL
CL
CL
CL
CL
1
2
3
4
5
13
25
22
33
50 (6")
18
16
14
16
0
TESTS
DESCRIPTION
RICHARDSON APARTMENTS
The stratification lines represent the approximate boundary lines
SITE
BORING STARTED
CME-55
WL
WL
WL
BORING COMPLETED
APPROVED MEW
DCFOREMANRIG
8-16-11
68115055
DEVELOPMENT DESIGN & ENGINEERINGCLIENT
LOG OF BORING NO. B-5
JOB #
GR
AP
HIC
LO
G
between soil and rock types: in-situ, the transition may be gradual.
Page 1 of 1
PROJECT
8-16-11WATER LEVEL OBSERVATIONS, ft
37TH STREET AND GRAND AVENUEARTESIA, NEW MEXICO
SAMPLES
US
CS
SY
MB
OL
WA
TE
RC
ON
TE
NT
, %
TY
PE
NU
MB
ER
5
10
15
20
DE
PT
H,
ft.
RE
CO
VE
RY
, in
.
SP
T -
NB
LOW
S \
ft.
DR
Y D
EN
SIT
Y
BO
RE
HO
LE_9
9 6
811
5055
.GP
J T
ER
RA
CO
N.G
DT
9/
13/1
1
- 200 =84.6%LL=30PI=125
11.5
LEAN CLAY; Light brown, stiff, dry.
Very stiff, carbonate indurated.
Boring terminated at 11.5 feet. No freewater encountered at time of drilling.
SS
SS
SS
CL
CL
CL
1
2
3
14
21
24
6.812
14
16
TESTS
DESCRIPTION
RICHARDSON APARTMENTS
The stratification lines represent the approximate boundary lines
SITE
BORING STARTED
CME-55
WL
WL
WL
BORING COMPLETED
APPROVED MEW
DCFOREMANRIG
8-16-11
68115055
DEVELOPMENT DESIGN & ENGINEERINGCLIENT
LOG OF BORING NO. B-6
JOB #
GR
AP
HIC
LO
G
between soil and rock types: in-situ, the transition may be gradual.
Page 1 of 1
PROJECT
8-16-11WATER LEVEL OBSERVATIONS, ft
37TH STREET AND GRAND AVENUEARTESIA, NEW MEXICO
SAMPLES
US
CS
SY
MB
OL
WA
TE
RC
ON
TE
NT
, %
TY
PE
NU
MB
ER
5
10
DE
PT
H,
ft.
RE
CO
VE
RY
, in
.
SP
T -
NB
LOW
S \
ft.
DR
Y D
EN
SIT
Y
BO
RE
HO
LE_9
9 6
811
5055
.GP
J T
ER
RA
CO
N.G
DT
9/
13/1
1
5
10
2020.33
LEAN CLAY; Light brown, very stiff, dry,carbonate indurated.
Dark brown to white, dry.
Hard, brown.
Gravelly.Boring terminated at 20.33 feet. No freewater encountered at time of drilling.
SS
RB
SS
SS
SS
CL
CL
CL
CL
CL
1
2
3
4
5
16
32
31
52
50 (4")
9.4
14
12
14
10
0
105
TESTS
DESCRIPTION
RICHARDSON APARTMENTS
The stratification lines represent the approximate boundary lines
SITE
BORING STARTED
CME-55
WL
WL
WL
BORING COMPLETED
APPROVED MEW
DCFOREMANRIG
8-16-11
68115055
DEVELOPMENT DESIGN & ENGINEERINGCLIENT
LOG OF BORING NO. B-7
JOB #
GR
AP
HIC
LO
G
between soil and rock types: in-situ, the transition may be gradual.
Page 1 of 1
PROJECT
8-16-11WATER LEVEL OBSERVATIONS, ft
37TH STREET AND GRAND AVENUEARTESIA, NEW MEXICO
SAMPLES
US
CS
SY
MB
OL
WA
TE
RC
ON
TE
NT
, %
TY
PE
NU
MB
ER
5
10
15
20
DE
PT
H,
ft.
RE
CO
VE
RY
, in
.
SP
T -
NB
LOW
S \
ft.
DR
Y D
EN
SIT
Y
BO
RE
HO
LE_9
9 6
811
5055
.GP
J T
ER
RA
CO
N.G
DT
9/
13/1
1
10
11.5
LEAN CLAY; Light brown, very stiff,carbonate indurated.
Brown to red-brown.
Boring terminated at 11.5 feet. No freewater encountered at time of drilling.
SS
SS
SS
CL
CL
CL
1
2
3
16
19
20
18
18
18
TESTS
DESCRIPTION
RICHARDSON APARTMENTS
The stratification lines represent the approximate boundary lines
SITE
BORING STARTED
CME-55
WL
WL
WL
BORING COMPLETED
APPROVED MEW
DCFOREMANRIG
8-16-11
68115055
DEVELOPMENT DESIGN & ENGINEERINGCLIENT
LOG OF BORING NO. B-8
JOB #
GR
AP
HIC
LO
G
between soil and rock types: in-situ, the transition may be gradual.
Page 1 of 1
PROJECT
8-16-11WATER LEVEL OBSERVATIONS, ft
37TH STREET AND GRAND AVENUEARTESIA, NEW MEXICO
SAMPLES
US
CS
SY
MB
OL
WA
TE
RC
ON
TE
NT
, %
TY
PE
NU
MB
ER
5
10
DE
PT
H,
ft.
RE
CO
VE
RY
, in
.
SP
T -
NB
LOW
S \
ft.
DR
Y D
EN
SIT
Y
BO
RE
HO
LE_9
9 6
811
5055
.GP
J T
ER
RA
CO
N.G
DT
9/
13/1
1
GENERAL NOTES DRILLING & SAMPLING SYMBOLS: SS: Split Spoon - 1-3/8" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger ST: Thin-Walled Tube - 2" O.D., unless otherwise noted PA: Power Auger RS: Ring Sampler - 2.42" I.D., 3" O.D., unless otherwise noted HA: Hand Auger DB: Diamond Bit Coring - 4", N, B RB: Rock Bit BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary
The number of blows required to advance a standard 2-inch O.D. split-spoon sampler (SS) the last 12 inches of the total 18-inch penetration with a 140-pound hammer falling 30 inches is considered the “Standard Penetration” or “N-value”. For 3” O.D. ring samplers (RS) the penetration value is reported as the number of blows required to advance the sampler 12 inches using a 140-pound hammer falling 30 inches, reported as “blows per foot,” and is not considered equivalent to the “Standard Penetration”or “N-value”.
WATER LEVEL MEASUREMENT SYMBOLS: WL: Water Level WS: While Sampling N/E: Not Encountered WCI: Wet Cave in WD: While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB: After Boring ACR: After Casing Removal
Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-term observations.
DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally 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 in-place relative density and fine-grained soils on the basis of their consistency.
CONSISTENCY OF FINE-GRAINED SOILS RELATIVE DENSITY OF COARSE-GRAINED SOILS
Unconfined
Compressive Strength, Qu, psf
Standard Penetration or N-value (SS)
Blows/Ft.
Consistency
Standard Penetration or N-value (SS)
Blows/Ft.
Ring Sampler (RS) Blows/Ft.
Relative Density < 500 0 - 1 Very Soft 0 – 3 0-6 Very Loose 500 – 1,000 2 - 4 Soft 4 – 9 7-18 Loose 1,000 – 2,000 4 - 8 Medium Stiff 10 – 29 19-58 Medium Dense 2,000 – 4,000 8 -15 Stiff 30 – 49 59-98 Dense 4,000 – 8,000 15 - 30 Very Stiff > 50 > 99 Very Dense 8,000+ > 30 Hard
RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGYDescriptive Term(s) of other
constituentsPercent of Dry Weight
Major Component of Sample
Particle Size
Trace < 15 Boulders Over 12 in. (300mm) With 15 – 29 Cobbles 12 in. to 3 in. (300mm to 75 mm)
Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75 mm)
RELATIVE PROPORTIONS OF FINESSand
Silt or Clay #4 to #200 sieve (4.75mm to 0.075mm)
Passing #200 Sieve (0.075mm)
PLASTICITY DESCRIPTION Descriptive Term(s) of other constituents
Percent of Dry Weight
Term Plasticity Index
Trace With
Modifiers
< 5 5 – 12 > 12
Non-plastic
Low Medium
High
0 1-10 11-30 > 30
UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Soil Classification
Group Symbol
Group NameB
Cu ≥ 4 and 1 ≤ Cc ≤ 3E GW Well-graded gravelFClean Gravels Less than 5% finesC
Cu < 4 and/or 1 > Cc > 3E GP Poorly graded gravelF
Fines classify as ML or MH GM Silty gravelF,G, H
Coarse Grained Soils
More than 50% retained
on No. 200 sieve
Gravels More than 50% of coarse fraction retained on No. 4 sieve Gravels with Fines More
than 12% finesC
Fines classify as CL or CH GC Clayey gravelF,G,H
Cu ≥ 6 and 1 ≤ Cc ≤ 3E SW Well-graded sandIClean Sands Less than 5% finesD
Cu < 6 and/or 1 > Cc > 3E SP Poorly graded sandI
Fines classify as ML or MH SM Silty sandG,H,I
Sands 50% or more of coarse fraction passes No. 4 sieve Sands with Fines
More than 12% finesD
Fines Classify as CL or CH SC Clayey sandG,H,I
PI > 7 and plots on or above “A” lineJ CL Lean clayK,L,MSilts and Clays Liquid limit less than 50
inorganic
PI < 4 or plots below “A” lineJ ML SiltK,L,M
Liquid limit - oven dried Organic clayK,L,M,N
Fine-Grained Soils 50% or more passes the No. 200 sieve
organic
Liquid limit - not dried < 0.75 OL
Organic siltK,L,M,O
inorganic PI plots on or above “A” line CH Fat clayK,L,M
Silts and Clays Liquid limit 50 or more
PI plots below “A” line MH Elastic SiltK,L,M
Liquid limit - oven dried Organic clayK,L,M,P organic
Liquid limit - not dried < 0.75 OH
Organic siltK,L,M,Q
Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat
A Based on the material passing the 3-in. (75-mm) sieve B If field sample contained cobbles or boulders, or both, add “with cobbles
or boulders, or both” to group name. C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded
gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay.
D Sands with 5 to 12% fines require dual symbols: 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
E Cu = D60/D10 Cc = 6010
230
DxD)(D
F If soil contains ≥ 15% sand, add “with sand” to group name. G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.
HIf fines are organic, add “with organic fines” to group name. I If soil contains ≥ 15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with
gravel,” whichever is predominant. L If soil contains ≥ 30% plus No. 200 predominantly sand, add
“sandy” to group name. M If soil contains ≥ 30% plus No. 200, predominantly gravel, add
“gravelly” to group name. N PI ≥ 4 and plots on or above “A” line. O PI < 4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line.
Form 111—6/98
APPENDIX B
LABORATORY TESTING
Geotechnical Engineering Report
Richardson Subdivision Apartments ■ Artesia, New Mexico
September 13, 2011 ■ Terracon Project No. 68115055
Reliable ■ Responsive ■ Convenient ■ Innovative
Exhibit B-1
Laboratory Testing
Samples retrieved during the field exploration were taken to the laboratory for further
observation by the project geotechnical engineer and were classified in accordance with the
Unified Soil Classification System (USCS) described in Appendix A. At that time, the field
descriptions were confirmed or modified as necessary and an applicable laboratory testing
program was formulated to determine engineering properties of the subsurface materials.
Laboratory tests were conducted on selected soil samples and the test results are presented
in this appendix. The laboratory test results were used for the geotechnical engineering
analyses, and the development of foundation and earthwork recommendations. Laboratory
tests were performed in general accordance with the applicable ASTM, local or other
accepted standards.
Selected soil samples obtained from the site were tested for the following engineering
properties:
Consolidation In-situ Water Content
Sieve Analysis In-situ Dry Density
Atterberg Limits
.
Sieve Size 1 1/2" 3/4" 3/8" #4 #10 #40 #100 #200
% Passing (Cumulative) 100% 100% 100% 98% 96% 94% 89% 77.7%
Specification
% GRAVEL = 2% D85 = 0.1 D15 =
% SAND = 20% D60 = D10 =
% SILT & CLAY = 78% D50 = CU =
D30 = CC =
Sample Date: 8/16/2011
Project No.: 681115055
Project Name: Richardson Apartments
Report Date: 9/13/2011
Sample Location: B1 at 2.5'
Liquid Limit: 31 13
USCS Classification: CL
Material Description: Lean Clay with Sand
Reviewed By:
Dan Cosper, P.E.
TEST SUMMARY
(575) 527-1700
TERRACON
1640 Hickory Loop, Suite 105
Las Cruces, NM 88005
Plasticity Index:
GRAIN SIZE - mm
GRAIN SIZE DISTRIBUTION GRAPH
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.0010.010.11101001000
PE
RC
EN
T F
INE
R
6 in
.
1.5
in
.
#4
#200
.
Sieve Size 1 1/2" 3/4" 3/8" #4 #10 #40 #100 #200
% Passing (Cumulative) 100% 100% 100% 100% 99% 98% 95% 85.6%
Specification
% GRAVEL = 0% D85 = D15 =
% SAND = 14% D60 = D10 =
% SILT & CLAY = 86% D50 = CU =
D30 = CC =
Sample Date: 8/16/2011
Project No.: 681115055
Project Name: Richardson Apartments
Report Date: 9/13/2011
Sample Location: B4 at 5'
Liquid Limit: 31 14
USCS Classification: CL
Material Description: Lean Clay
Reviewed By:
Dan Cosper, P.E.
TEST SUMMARY
(575) 527-1700
TERRACON
1640 Hickory Loop, Suite 105
Las Cruces, NM 88005
Plasticity Index:
GRAIN SIZE - mm
GRAIN SIZE DISTRIBUTION GRAPH
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.0010.010.11101001000
PE
RC
EN
T F
INE
R
6 in
.
1.5
in
.
#4
#200
.
Sieve Size 1 1/2" 3/4" 3/8" #4 #10 #40 #100 #200
% Passing (Cumulative) 100% 100% 100% 100% 99% 99% 95% 84.6%
Specification
% GRAVEL = 0% D85 = 0.1 D15 =
% SAND = 15% D60 = D10 =
% SILT & CLAY = 85% D50 = CU =
D30 = CC =
Sample Date: 8/16/2011
Project No.: 681115055
Project Name: Richardson Apartments
Report Date: 9/13/2011
Sample Location: B6 at 2.5'
Liquid Limit: 30 12
USCS Classification: CL
Material Description: Lean Clay
Reviewed By:
Dan Cosper, P.E.
TEST SUMMARY
(575) 527-1700
TERRACON
1640 Hickory Loop, Suite 105
Las Cruces, NM 88005
Plasticity Index:
GRAIN SIZE - mm
GRAIN SIZE DISTRIBUTION GRAPH
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.0010.010.11101001000
PE
RC
EN
T F
INE
R
6 in
.
1.5
in
.
#4
#200
RICHARDSON APARTMENTS
ARTESIA, NEW MEXICOTERRACON
1640 Hickory Loop, Suite 105
LAS CRUCES, NEW MEXICO 88005
(575) 527-1700
fax (575) 527-1092
CONSOL-B-1@5'.xls
BORING B-1 @ 5'
LEAN CLAY
USCS Classification:
CL
DRY DENSITY= 87 lbs/ft3
MOISTURE CONTENT= 6.4%
PROJECT NO. 68115055
-15
-13
-11
-9
-7
-5
-3
-1
10 100 1000 10000
PE
RC
EN
T C
ON
SO
LID
AT
ION
/ S
WE
LL
STRESS POUNDS PER SQUARE FOOT
SWELL/CONSOLIDATION CHART
water added
RICHARDSON APARTMENTS
ARTESIA, NEW MEXICOTERRACON
1640 Hickory Loop, Suite 105
LAS CRUCES, NEW MEXICO 88005
(575) 527-1700
fax (575) 527-1092
CONSOL-B-3@5'.xls
BORING B-3 @ 5'
LEAN CLAY
USCS Classification:
CL
DRY DENSITY= 87 lbs/ft3
MOISTURE CONTENT= 5.9%
PROJECT NO. 68115055
-26
-23
-20
-17
-14
-11
-8
-5
-2
10 100 1000 10000
PE
RC
EN
T C
ON
SO
LID
AT
ION
/ S
WE
LL
STRESS POUNDS PER SQUARE FOOT
SWELL/CONSOLIDATION CHART
water added
RICHARDSON APARTMENTS
ARTESIA, NEW MEXICOTERRACON
1640 Hickory Loop, Suite 105
LAS CRUCES, NEW MEXICO 88005
(575) 527-1700
fax (575) 527-1092
CONSOL-B-7@5'.xls
BORING B-7 @ 5'
LEAN CLAY
USCS Classification:
CL
DRY DENSITY= 105 lbs/ft3
MOISTURE CONTENT= 9.4%
PROJECT NO. 68115055
-6
-5
-4
-3
-2
-1
0
10 100 1000 10000
PE
RC
EN
T C
ON
SO
LID
AT
ION
/ S
WE
LL
STRESS POUNDS PER SQUARE FOOT
SWELL/CONSOLIDATION CHART
water added