SW6170801 - JSOC, SOF Truck Inspection Point (4)

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SUBSURFACE EXPLORATION
AND
GEOTECHNICAL RECOMMENDATIONS REPORT
SOF Truck Inspection Point, FY 17, PN 87604
Fort Bragg, North Carolina
By:
Chris Norton, P.E., Civil Engineer
Geotechnical and Dam Safety Section
U.S. Army Corps of Engineers, Wilmington District
April 2017

This report was prepared by the Wilmington District of the U.S. Army Corps of Engineers. The initials or
signatures and registration designation of individuals appear on these documents within the scope of
their employment as required by Engineer Regulation 1110-1-8152
Date: 19 April 2017
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Christopher A. Norton, P.E.
Civil Engineer
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Geotechnical and Dam Safety Section
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Saul Carlson, E.I.
Civil Engineer
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Geotechnical and Dam Safety Section

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TABLE OF CONTENTS
PURPOSE.......................................................................................................................................................1
QUALIFICATION OF REPORT..........................................................................................................................1
PROJECTDESCRIPTION..................................................................................................................................1
EXPLORATIONPROCEDURES.........................................................................................................................1
SiteReconnaissance.................................................................................................................................1
SoilBorings and DCP Testing................................................................................................................... 2
SoilInfiltration Testing.............................................................................................................................2
SITE AND SUBSURFACE CONDITIONS............................................................................................................3
SiteConditions......................................................................................................................................... 3
Regionaland Site Geology.......................................................................................................................3
SubsurfaceConditions............................................................................................................................. 4
GroundwaterConditions......................................................................................................................... 4
ENGINEERING EVALUATIONS AND RECOMMENDATIONS............................................................................4
General.................................................................................................................................................... 4
Geotechnical Investigations..................................................................................................................... 5
Excavation, Grading, and Fill................................................................................................................... 5
Damp -proofing and Water-proofing....................................................................................................... 5
Presumptive Load -Bearing Values of Soils...............................................................................................5
Foundations............................................................................................................................................. 6
ShallowFoundations................................................................................................................................ 6
FrostSusceptibility................................................................................................................................... 6
SeismicSite Classification........................................................................................................................7
Liquefaction.............................................................................................................................................7
ATTACHMENT A: 35% Design Submittal — Site Plan
ATTACHMENT B: Boring, DCP, and Infiltration Testing Location Plan
ATTACHMENT C: Soil Test Boring Logs
ATTACHMENT D: CBR and UBC Tabulations
ATTACHMENT E: Infiltration Test Tabulations
ATTACHMENT F: Michigan Method — Soil Infiltration Testing

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PURPOSE
The purpose of this "Subsurface Exploration and Geotechnical Recommendations Report" is to present
the findings and evaluation of subsurface data collected on 27 and 28 February, 2017, at the proposed
Special Operations Facilities (SOF) Truck Inspection Point. This report provides a general overview of the
site and subsurface conditions encountered along the proposed components in the 35 percent design
submittal, which was provided to the Wilmington District on 13 January, 2017 (Attachment A). The
proposed components consist of an asphalt roadway, a concrete foundation for a truck canopy, a
proposed infiltration basin, and a proposed processing building. The processing building will be founded
on a shallow slab on grade concrete foundation. Preliminary engineering evaluations and
recommendations are also provided with respect to the geotechnical design and construction of the
project.
QUALIFICATION OF REPORT
The subsurface investigation was conducted to determine soil and groundwater conditions and were not
intended to serve as an assessment of site wetlands, environmental, or contaminant conditions. The
Architect -Engineer's (A-E) team should include a Registered Design Professional, henceforth referred to
as Design Professional, with an appropriate amount of experience in geotechnical engineering design.
The Design Professional should be able to interpret this report, make a determination if a more
extensive subsurface investigation is required, and develop foundation and earthwork
recommendations and design parameters. Any additional subsurface investigations and laboratory
analyses conducted to better characterize the site and to develop the final design should be performed
under the direction of a Design Professional with an appropriate amount of experience in geotechnical
engineering design.
PROJECT DESCRIPTION
The proposed 35 percent site layout plan can be seen in Attachment A, and consists of the design and
construction of an asphalt roadway, a truck inspection canopy with a concrete foundation, a processing
building with a shallow slab -on -grade foundation, and an infiltration basin. The project will be
constructed on the northwest corner of the JSOC compound, just South of Pope Airfield. The road will
tie into Hurst Drive at two points — an entrance near the far west point of the compound, and an exit
near the northern -most point — before curving south and tying into Malvesti Street. The infiltration basin
will be constructed towards the west end of the project between the new road and the existing parking
lot. The inspection canopy will be located along the new road, and the processing building will be
located between the existing building to the south and the exit to Hurst drive to the north. A new
security fence will be placed adjacent to the new road separating the construction from the rest of the
JSOC compound. Please review Attachment A for more details.
EXPLORATION PROCEDURES
Site Reconnaissance
Before the field investigation was performed, the proposed project site(s) and surrounding areas were
visually inspected. The observations were used in planning the subsurface exploration, in determining
areas of special interest, and in relating site conditions to known geologic conditions in the area.
1

Soil eorinas and DCP Testin
Subsurface conditions along the proposed asphalt roadway were evaluated by seven (7) soil test borings
labeled SOFTI-HA-17-01 through SOFTI-HA-17-07 and companion Dynamic Cone Penetrometer (DCP)
testing (SOFT[-DCP-17-01 through SOFTI-DCP-17-07). The borings acquired along the proposed roadway
were taken to a depth of approximately 3.5 -ft Below Ground Surface (BGS), and the companion DCP
tests were conducted to approximately 30 -inches BGS. One (1) boring (SOFT[ -HA -17-08) was acquired
within the infiltration basin, and was conducted to 6.5 -feet BGS. Companion DCP testing was not
conducted for this boring. Two (2) DCP tests were acquired within the footprint of the processing
building (SOFTI-DCP-17-08 and SOFTI-DCP-17-09), and were conducted to approximately 36 -inches BGS.
Borings and DCP testing were conducted to visually classify and estimate soil engineering parameters,
respectively. These parameters may be used in the evaluation and design of the proposed project.
Borings and DCP testing were conducted at the approximate locations shown in Attachment B. North
Carolina State Plane Coordinates (U.S. Survey Feet) of borings, DCP testing, and infiltration testing are
indicated in Attachments C, D, and E, respectively. Boring coordinates were established by an iPhone 7,
and are considered approximate. Depths are based upon top of hole at existing grade at the time of
investigation. Should any site work take place after this investigation that changes the existing grade,
the depths and associated soil classifications and engineering evaluations given in this report may be
inaccurate.
The soil test borings were conducted by use of a Hand Auger (HA), which consists of 5 -foot sections with
a 3.25 -inch diameter steel barrel sampler. The DCP used for this investigation conforms to American
Standard Test Method (ASTM) D6951, and utilizes a 17.6 -Ib hammer that is dropped (free fall) a distance
of 22.6 -inches, impacting an anvil attached to the drive rod. The impact drives a 602 cone, attached to
the end of the drive rod, into the material of interest. One impact is equivalent to one "blow count". The
number of blow counts per inch of penetration is recorded (number blow counts)/(inch of penetration).
The blow counts are then used to calculate the California Bearing Ratio (CBR) for each inch of strata. The
CBR is a comparison of the penetration resistance of a soil to the penetration into a standard crushed
stone sample. Penetration resistance, when properly evaluated, is an index of the soil's strength,
density, and foundation support capability. Equations used to calculate the CBR are described in ASTM
D6951. A correlation between the CBR and Ultimate Bearing Capacity (UBC) has been developed by the
U.S. Army Corps of Engineers (USACE). The derivation of the correlation equation can be found in the
research paper titled "Evaluation of In -Situ Pavement Layers with the Dynamic Cone Penetrometer
(DCP)", Jeb S. Tingle, et al. The Design Professional should note that the UBC equation does not account
for the Ground Water Table (GWT).
Soil classifications are shown on the Soil Test Boring Logs in Attachment C, and were determined in the
field by a Design Professional. Soil samples were classified in accordance with ASTM D2488 (Visual -
Manual Procedure for Descriptions of Soils). The soil descriptions and classifications are based on visual
examination only; no lab analyses were conducted. CBR and UBC tabulations are included in Attachment
D of this report.
Soil Infiltration Testing
Soil infiltration tests were performed at two (2) locations (SOFTI-INF-17-1 and SOFTI-INF-17-2), and can
be seen in Attachment B. These locations were selected based on the proposed location of the
infiltration basin.
2

i A
The infiltration tests were conducted using a modified version of the "Michigan Method". The "Michigan
Method" procedure can be seen in Appendix F. The infiltration testing procedure used for these tests
include utilizing a 3 -inch diameter PVC pipe inserted into a bored hole to the bottom elevation of the
stilling basin. The required bore depth was calculated for each hole by using the topographic map and
the basin bottom elevation provided in the 35 percent design submittal in Attachment A. After boring
the required depth, the PVC pipe was inserted to the bottom of the hole and into the soil approximately
2 inches. The reason for insertion into the soil is to confine the water to the pipe and minimize
horizontal infiltration, thus eliminating the need for reduction factors. Before the pipe was filled with
water, approximately 3 -4 -inches of pea gravel was placed into the bottom of the hole. After placing the
gravel, the pipe was filled to the approximate ground surface elevation for each hole. The depth from
the top of pipe to the water level was measured initially, and then again at various intervals for at least
an hour, with water being added as needed. Each drop in water surface was recorded in conjunction
with the time interval for an infiltration rate of inches/hour. The last recorded reading was considered to
be the most accurate infiltration rate, as the soil has become saturated and infiltration rates are
reduced.
This test method is believed to simulate how a water column reacts vertically with the soil, and inhibits
horizontal infiltration, thus eliminating the need for a reduction factor.
SITE AND SUBSURFACE CONDITIONS
Site Conditions
The general site layout can be seen in Attachment A. The proposed project is located on the JSOC
Compound. The new asphalt road will be constructed over an existing gravel drive from the west
entrance through the exit onto Hurst Drive. There is a small cluster of trees and an existing infiltration
basin towards the west end of the project site where the new, larger infiltration basin will be located.
The processing building will be located in an open, grassy area just north of the northernmost existing
building, and the road — after the Hurst Drive exit — will continue through another, larger wooded area.
There is a 10 -ft gain in elevation from the west to the east end of the site — over about 400 feet.
Regional and Site Geology
Fort Bragg is situated in the Sand Hills area of the Coastal Plain physiographic province of North Carolina.
The Coastal Plain extends westward from the Atlantic Ocean to the Fall Line, a distance of about 130
miles. The Fall Line is the boundary between the Coastal Plain and the Piedmont physiographic
provinces.
Geologic units in the area, ranging from oldest to youngest, include the Carolina Slate Belt rocks, which
are the basement rocks, the Cape Fear Formation, and the Middendorf Formation. The Cape Fear and
Middendorf Formations overlie the basement rock and are part of the generally southeastward -dipping
and thickening wedge of sediments that constitute the Atlantic Coastal Plain deposits. The Middendorf
Formation is exposed at land surface throughout the area. The formation is composed of tan, cross -
bedded, medium and fine-grained, micaceous quartz sand and clayey sand interbedded with clay or
sandy clay lenses or layers. Layers of hematite -cemented sandstone occur locally throughout the
Middendorf Formation as do thin layers of hard kaolin and kaolin -cemented sandstone. Below the water
table, these units are generally friable or plastic. In places, the Middendorf Formation is mottled orange,
gray, and tan color with streaks and laminae of red and purple hematite and manganese oxide stains.
3

Subsurface Conditions
Soil test borings SOFTI-HA-17-1 through SOFTI-HA-17-8 indicate a stratigraphy consisting of Poorly
Graded Sand (SP), Poorly Graded Sand with Silt (SP -SM), Poorly Graded Sand with Clay (SP -SC), Clayey
Sand (SC), and Lean Clay (CL). Fat Clay (CH) was not encountered during this investigation. Soil test
boring logs are located in Attachment C.
DCP tests SOFTI-DCP-17-1 through SOFTI-DCP-17-9 indicate a range of CBRs and associated UBCs from
approximately 4 percent (1300-psf) to 260 percent (22000-psf). The higher values were encountered
within the lower half of most tests, and may have been influence by root systems. DCP tests SOFTI-DCP-
17-3, SOFTI-DCP-17-4, SOFTI-DCP-17-5, and SOFTI-DCP-17-6 indicate material with a CBR less than 7
percent (approximately 2000-psf), with the lowest strength material exhibiting a CBR of 4 percent (1300-
psf) in tests SOFTI-DCP-17-3 and SOFTI-DCP-17-5. CBR and UBC values for all tests are indicated in
Attachment D.
Infiltration test data indicates infiltration rates of approximately 1.5 -inches per hour for SOTF-INF-17-1
and 9 -inches per hour for SOTF-INF-17-2. All test data for the infiltration testing can be seen in
Attachment E.
The above subsurface description is of a generalized nature to highlight the major subsurface
stratification features and material characteristics. The soil test boring logs should be reviewed for
specific information at individual boring locations. The stratifications shown on the soil test boring logs
represent the conditions at the actual boring locations only. Variations should be expected between
boring locations. The stratification lines shown on the soil test boring logs represent the approximate
boundaries between the subsurface materials; the actual transitions are typically more gradual.
Groundwater Conditions
The apparent GWT was located at approximately 4.5 -feet BGS within borehole SOFT[ -HA -17-8, which is
located within the proposed infiltration basin. The approximate ground surface elevation at this location
is estimated to be at 225 -feet (NAVD 88), placing the GWT at approximately 220.5 -feet.
Due to the prevalence of SC, SP -SC, and CL at the project site, varying levels of perched water conditions
could be encountered before, during, or after construction. A perched -water condition occurs when
water seeping downward is blocked by a low permeability soil layer, such as SC or CL, and saturates the
more permeable soil above it. The true GWT can be several to many feet below the perched -water level.
It should be noted that the GWT may vary during periods of prolonged drought and excessive rainfall, as
well as seasonally. Therefore, fluctuations in the GWT should be anticipated with changing climatic and
rainfall conditions. The Seasonal High Water Table (SHWT) was not encountered in any soil test borings.
ENGINEERING EVALUATIONS AND RECOMMENDATIONS
General
Chapters 16, 17, 18, and 33 of the International Building Code (IBC) 2012, adopted and modified by the
Unified Facilities Criteria (UFC) 3-220-01 of 2012, are the primary design standards referenced for these
recommendations. The following evaluations and recommendations are based on the information
available on the proposed structures, observations made at the project site, interpretation of the data
4

a,
obtained from the soil test borings and associated DCP testing, and previous experience with soils and
subsurface conditions similar to those encountered at the site.
Geotechnical Investigations
A preliminary geotechnical investigation was conducted at the proposed project site by the Wilmington
District, and the results are discussed in this report. This`investigation may not meet all requirements set
forth in Section 1803, IBC 2012, adopted and modified by Section 2-3.3, UFC 3-220-01, and this report
should be evaluated accordingly.
Excavation, Grading, and Fill
It is recommended that the Design Professional adhere to the requirements set forth in Section 1804,
IBC 2012, adopted and modified by Section 2-3.4, UFC 3-220-01.
Where shallow foundations will bear on compacted fill material, the compacted fill should comply with
the criteria set forth in Section 1804.5, IBC 2012.
Where shallow foundations will bear on Controlled Low -Strength Material (CLSM), the CLSM should
comply with the criteria set forth in Section 1804.6, IBC 2012.
Damp -proofing and Water -proofing
It is recommended that the Design Professional adhere to the requirements set forth in Section 1805,
IBC 2012, adopted and modified by Section 2-3.5, UFC 3-220-01. This may include additional
investigations) to verify the depth of the GWT or SHWT per Section 1803.5.4, IBC 2012, adopted and
modified by Section 2-3.3.4 of UFC 3-220-01.
Presumptive Load -Bearing Values of Soils
It is recommended that the Design Professional adhere to the requirements set forth in Section 1806,
IBC 2012, adopted and modified by Section 2-3.6, UFC 3-220-01.
As described above, soils with CBR values less than 7 percent were encountered at various locations and
depths along the proposed asphalt roadway. It is recommended that these soils be improved to increase
loading capacity if they are found to be within the minimum required distance from the subbase or
base, or accounted for by increasing subbase, base, or asphalt thickness. For both DCP tests conducted
within the proposed processing building footprint (SOFTI-DCP-17-8 and SOFTI-DCP-17-9), no soils were
encountered with a bearing capacity of less than 2000-psf.
The Design Professional should evaluate this geotechnical investigation report, and determine if an
additional geotechnical investigation is required to confirm the load bearing values indicated in this
report. The Design Professional should also use the Factors of Safety (FS) shown in Tables 2-2 and 2-3,
UFC 3-220-01, when developing the net allowable bearing capacities that will be used for design. All
bearing capacities given in Attachment D are Ultimate Bearing Capacities, and should be reduced to
Allowable Bearing Capacities upon selection of the FS.

Foundations
It is recommended that foundations be designed and constructed in accordance with Sections 1808.2
through 1808.9, IBC 2012, adopted and modified by Section 2-3.8, UFC 3-220-01.
The foundation should be designed such that the net allowable bearing capacity of the soil is not
exceeded, and that total and differential settlement is limited to acceptable values. The net allowable
bearing capacity should be evaluated by the Design Professional. Acceptable settlement values can be
found in Section 2-3.8.1, UFC 3-220-01.
The foundation should be designed for the most unfavorable effects due to the combinations of loads
specified in Chapter 16, IBC 2012. The Design Professional should also consider possible future events
such as dewatering and flooding due to storms.
Expansive soils are not believed to exist at the site, however the Design Professional should make this
determination and adhere to Section 1808.6, IBC 2012, adopted and modified by Section 2-3.8.4, UFC 3-
220-01, should expansive soils be determined to exist at the site.
Shallow Foundations
It is recommended that shallow foundations be designed and constructed in accordance with Sections
1809.2 through 1809.13, IBC 2012, adopted and modified by Section 2-3.9, UFC 3-220-01.
Shallow foundations should be built on undisturbed soil, compacted fill material, or CLSM in accordance
with Section 1809.2, IBC 2012. Fill material and CLSM should meet the criteria discussed in "Excavation,
Grading, and Fill" of this report.
For excavations, it is recommended that the top 12 -inches of finished subgrade be compacted to 95
percent of maximum dry density per ASTM D698.
For fill, it is recommended that material be placed in 6 -inch lifts and compacted to 95 percent of
maximum dry density per ASTM D698. Fill material should not be placed over wet or frozen areas. Fill
material should be placed adjacent to structures, such as footings, after the structures have been
completed and accepted, and should be compacted as to avoid loading upon or against the structure.
Footings should be constructed at a minimum depth of 18 -inches below the finished ground surface.
Spacing between footings should be at least 1.5 times the width of the larger foundation to minimize
any reduction in bearing capacity due to overlapping zones of influence. The minimum width of footings
should be 12 -inches.
Frost Susceptibility
Frost susceptible soils are defined in American Society of Civil Engineers (ASCE) 32, and consist of soil
with greater than 6 percent by mass passing the #200 sieve in accordance with ASTM D422. Lab analyses
of collected samples were not conducted as part of this geotechnical investigation. Due to the suspected
clay content encountered in the soil test borings, it is recommended that the Design Professional
determine if frost susceptible soils exist at the site, and if so, protect the foundation and other
permanent supports by one or more of the following methods indicated in Section 1809.5, IBC 2012,
adopted and modified by Section 2-3.9, UFC 3-220-01.
0

Seismic Site Classification
This geotechnical investigation is inadequate to provide the Seismic Site Classification (SSC) for the
proposed building site. It is recommended that the Design Professional adhere to Section 1613.3.2, IBC
2012, adopted and modified by Section 2-1.1.2, UFC 3-220-01, in order to verify the SSC. The SSC is
designated as A, B, C, D, E, or F in accordance with Chapter 20 of ASCE 7-10. The building official may
provide an assumed SSC, however if one is not provided, and the soil properties are not known in
sufficient detail to verify the SSC, an SSC of D may be assumed for preliminary purposes. For design
purposes, the Design Professional should verify the SSC by performing at least one boring to a depth of
100 -ft or refusal (defined as N>100 blows per foot), or other method as determined by the building
official.
Liquefaction
This geotechnical investigation is inadequate to provide an assessment of liquefaction potential. It is
recommended that the Design Professional adhere to Section 1613, IBC 2012, adopted and modified by
Section 2-1.1, UFC 3-220-01, regarding the assessment of liquefaction potential.
7

ATTACH M E IVT A
35% Design Submittal—Site Plan

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ATTACHMENT B
Boring, DCP, and Infiltration Testing Location Plan

Legend
SOF Truck Inspection Point, Ft. Brag
& Soil Test Boring/ Companion DCP Test
PROJECT LIMITS&IMITS
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This geotechnical investigation was conducted without the benefit of survey stake -out.
Is PI'PCLA°S IV ATORM PROPOSE: DS A�4
'NF, The locations of soil test borings and companion Dynamic Cone Penetration (DCP) testing
Ex DUCT BANK "AS ITIA�,-- BA
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T1114 _ 1 were based upon a measured distance from existing structures shown in the 35 percent
SOFTI-HA-17-2 SOFTI-DCP-17-2 FONOIWG F 2'�4 50
design submittal, which is transparent in this map.
SOFTI-INF-17-21
GPS coordinates were recorded using an Whone 7, therefore boring/DCP/infiltration
testing locations should be considered approximate.
HA = Hand Auger Boring
SO FTI -HA -17-1 SOFTI-DCP-17-1
__EROPOSPC� CON �IL
HETA'�
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DCP = Dynamic Cone Penetrometer Test
INF = Infiltration Test
X pnopo',FD SEGMENTAL 81,0CIK A total of eight (8) HA borings were acquired, including seven (7) borings along the
C,5X RETAINNOWALL proposed asphalt roadway and one (1) within the infiltration basin. Nine (9) total DCP
Gf"E CfYPI
tests were acquired, including seven (7) companion tests along the proposed roadway
N and two (2) tests within the proposed processing building footprint. Two (2) infiltration
rPOJEC r H%!JTSA 011 TS
Dzi OPsANCE ( rM tests were acquired within the proposed infiltration basin footprint. N
0 25 50 100 ft

ATTACHMENT C
Soil Test Boring Logs

DRILLING LOG South Atlantic Division
1.PROJECT
SOF JSOC Truck Inspection Point
2. HOLE NUMBER LOCATION COORDINATES
SOFTI-HA-17-1 N 514615.004 E 1996521.217
3 DRILLING AGENCY
USACE, Wilmington District
4 NAME OF DRILLER
Chris Norton and Saul Carlson
5. DIRECTION OF BORING DEG FROM : BEARING
® VERTICAL : VERTICAL
0 INCLINED
6 THICKNESS OF OVERBURDEN
7. DEPTH DRILLED INTO ROCK
8 TOTAL DEPTH OF BORING 3.0 -ft
DEPTH SCALE LEGEND FIELD CLASSIFICATION OF MATERIALS
(feet) (feet) (Description)
a b c d
-1 5
Fort Bragg, NC
5Ur II I -FIA -1 /-1
SHEET 1
OF 1 SHEETS
VERTICAL
NAVD88
9. COORDINATE SYSTEM HORIZONTAL
NAD83
10 SIZE AND TYPE OF BIT 3--
11 MANUFACTURER'S DESIGNATION OF DRILL
12 TOTAL SAMPLES : DISTURBED
4
UNDISTURBED
0
13. TOTAL NUMBER CORE BOXES 0
14. ELEVATION GROUND WATER GWT depth in Column "a--
15. DATE BORING
:STARTED COMPLETED
2/27/17 2/27/17
16. ELEVATION TOP OF BORING Elevation from Attachment B
17. TOTAL CORE RECOVERY FOR BORING
18. SIGNATURE AND TITLE OF INSPECTOR
Chris Norton, P.E., Civil Engineer
BOX OR REMARKS
SAMPLE # (Drilling time, water loss, depth of
f weathering, etc , if significant)
9
Boring was acquired with a Hand Auger
(HA)
0.0 IPoorly Graded Sand with Silt (SP -SM), brown, fine to
medium grained, non -plastic, some organics
1.0Clayey Sand (SC), orange to brown, fine to medium
grained
20
Clayey Sand (SC), orange to brown, fine to medium
grained
Clayey Sand (SC), orange to brown, fine to medium
grained
3.0 BOTTOM OF BOREHOLE AT 3.0 -ft
SOILS ARE FIELD VISUALLY CLASSIFIED IN
ACCORDANCE WITH THE UNIFIED SOIL
- CLASSIFICATION SYSTEM
S-1
S-2
Sa
s.a
Drafted By: Chris Norton, P.E. Reviewed By: Saul Carlson, E I.
a -fl, Date Drafted: 4/11/2017 Date Checked: 4/13/2017
Wl�mtngton DIsWd VERSION: Final
Geotechnical and Dam Safety Swdon
SAW FORM 1836-A (SOIL BORING) Boring Designation SOFTI-HA-17-1 SHEET 1 of 1
Ul:l N"IJ

DRILLING LOG South Atlantic Division
1 PROJECT
SOF JSOC Truck Inspection Point
2. HOLE NUMBER : LOCATION COORDINATES
SOFTI-HA-17-2 N 514684.151 E 1996539.157
3. DRILLING AGENCY
USACE, Wilmington District
4. NAME OF DRILLER
Chris Norton and Saul Carlson
5 DIRECTION OF BORING : DEG FROM : BEARING
® VERTICAL : VERTICAL
INCLINED ---
6 THICKNESS OF OVERBURDEN
7. DEPTH DRILLED INTO ROCK
8. TOTAL DEPTH OF BORING 3.5 -ft
DEPTH SCALE LEGEND FIELD CLASSIFICATION OF MATERIALS
(feet) (feet) (Descnphon)
a b c d
SIM
Borina Designation SUF 11-11A-'1 /-2
INSTALLATION SHEET 1
Fort Bragg, NC OF 1 SHEETS
9 COORDINATE SYSTEM : HORIZONTAL : VERTICAL
NAD83 NAVD88
10 SIZE AND TYPE OF BIT 3"
11 MANUFACTURER'S DESIGNATION OF DRILL
12 TOTAL SAMPLES : DISTURBED = UNDISTURBED
5 0
13. TOTAL NUMBER CORE BOXES 0
14 ELEVATION GROUNDWATER GWT depth In column aaa
:STARTED COMPLETED
15. DATE BORING 2/27/17 2/27/17
16 ELEVATION TOP OF BORING Elevation from Attachment B
17 TOTAL CORE RECOVERY FOR BORING
18 SIGNATURE AND TITLE OF INSPECTOR
Chris Norton, P.E., Civil Engineer
BOX OR REMARKS
SAMPLE # (Dnlling hme, water loss, depth of
f weathering, etc, if significant)
9
Boring was acquired with a Hand Auger
(HA)
0 0 Poorly Graded Sand with Silt (SP -SM), brown, fine to
medium grained, non -plastic, little organics
S-1
Lean Clay (CL), brown
S-2
1 0 Poorly Graded Sand with Silt (SP -SM), brown, fine to
J.medium grained
S3
Poorly Graded Sand (SP), brown, fine to medium `
grained I "
Sa
2.0 V11111 Clayey Sand (SC), brown, fine to medium grained
30
BOTTOM OF BOREHOLE AT 3.5 -ft
SOILS ARE FIELD VISUALLY CLASSIFIED IN
ACCORDANCE WITH THE UNIFIED SOIL
CLASSIFICATION SYSTEM
Drafted By: Chris Norton, P.E.
"tet Date Drafted: 4/11/2017
Wllmington District
Geotechnical and Dam Safety Section
SAW FORM 1836-A (SOIL BORINGI
OCT 2013
S5
2.5
Reviewed By: Saul Carlson, E.I.
Date Checked: 4113/2017
VERSION: Final
Rnrinn ns Qinna+inn SnFTI-HA-17-7 SHEET 1 of 1

DRILLING LOG South Atlantic Division
1 PROJECT
SOF JSOC Truck Inspection Point
2. HOLE NUMBER LOCATION COORDINATES
SOFTI-HA-17-3 N 514767.854 E 1996572.042
3 DRILLING AGENCY
USACE, Wilmington District
4. NAME OF DRILLER
Chris Norton and Saul Carlson
5. DIRECTION OF BORING : DEG FROM : BEARING
® VERTICAL : VERTICAL
INCLINED
6 THICKNESS OF OVERBURDEN
7 DEPTH DRILLED INTO ROCK
8. TOTAL DEPTH OF BORING 3.5 -ft
DEPTH SCALE LEGEND FIELD CLASSIFICATION OF MATERIALS
(feet) (feet) (Descnpbon)
a b c d
INSTALLATION
Fort Bragg, NC
9. COORDINATE SYSTEM HC
10. SIZE AND TYPE OF BIT 3"
11. MANUFACTURER'S DESIGNATION OF
12. TOTAL SAMPLES : DISTU
UF I 1 -HA -1 /-3
SHEET 1
OF 1 SHEETS
RIZONTAL VERTICAL
NAD83 NAVD88
ED UNDISTURBED
4 0
13. TOTAL NUMBER CORE BOXES 0
14. ELEVATION GROUND WATER GWT depth In column "a"
:STARTED :COMPLETED
15. DATE BORING 2/27/17 2/27/17
16 ELEVATION TOP OF BORING Elevation from Attachment B
17 TOTAL CORE RECOVERY FOR BORING
18 SIGNATURE AND TITLE OF INSPECTOR
Chris Norton, P.E., Civil Engineer
BOX OR REMARKS
SAMPLE # (Dnlbng time, water loss, depth of
f weathering, etc, ifsignificant)
9
Boring was acquired with a Hand Auger
(HA)
0.0 Poorly Graded Sand with Silt (SP -SM), brown, fine to -
medium grained, non -plastic, little organics
s -t
Clayey Sand (SC), brown, fine to medium grained
S-2
1.0 Poorly Graded Sand with Silt (SP -SM), brown, fine to
medium grained
sa
2.0
3.0 Poorly Graded Sand with Clay (SP -SC), brown, moist,
fine to medium grained
BOTTOM OF BOREHOLE AT 3.5 -ft
SOILS ARE FIELD VISUALLY CLASSIFIED IN
ACCORDANCE WITH THE UNIFIED SOIL
CLASSIFICATION SYSTEM
Drafted By: Chris Norton, P.E. Reviewed By: Saul Carlson, E I
Date Drafted: 4/11/2017 Date Checked: 4/13/2017
Wilmington Dlswd VERSION: Final
Geotechnical and Dam Safety Section
SAW FORM 1836-A (SOIL BORING) Boring Designation SOFTI-HA-17-3 SHEET 1 of 1
)G I Lu13

0
DRILLING LOG """'
South Atlantic Division
1.PROJECT
SOF JSOC Truck Inspection Point
2 HOLE NUMBER LOCATION COORDINATES
SOFTI-HA-17-4 N 514858.831 E 1996646.768
3. DRILLING AGENCY
USACE, Wilmington District
4 NAME OF DRILLER
Chris Norton and Saul Carlson
5 DIRECTION OF BORING DEG FROM : BEARING
® VERTICAL : VERTICAL
INCLINED ""-
6 THICKNESS OF OVERBURDEN
7 DEPTH DRILLED INTO ROCK
8 TOTAL DEPTH OF BORING 3.5 -ft
DEPTH SCALE LEGEND FIELD CLASSIFICATION OF MATERIALS
(feet) (feet) (Descnpbcn)
a b c d
-05
Boring Designation SUFI 1 -HA -1-4
INSTALLATION SHEET 1
Fort Bragg, NC OF 1 SHEETS
9 COORDINATE SYSTEM HORIZONTAL : VERTICAL
NAD83 NAVD88
10 SIZE AND TYPE OF BIT 31'
11 MANUFACTURER'S DESIGNATION OF DRILL
12. TOTAL SAMPLES DISTURBED : UNDISTURBED
5 0
13 TOTAL NUMBER CORE BOXES 0
14 ELEVATION GROUNDWATER GWT depth in column "a"
STARTED COMPLETED
15 DATE BORING 2/27/17 2/27/17
16. ELEVATION TOP OF BORING Elevation from Attachment B
17. TOTAL CORE RECOVERY FOR BORING
18. SIGNATURE AND TITLE OF INSPECTOR
Chris Norton, P.E., Civil Engineer
BOX OR REMARKS
SAMPLE # (Dnllmg time, water loss, depth of
f weathenng, etc., if significant)
9
Boring was acquired with a Hand Auger
(HA)
0.0 Poorly Graded Sand with Silt (SP -SM), brown, fine to
medium grained, non -plastic, little organics, little clay
1.0
20
Poorly Graded Sand with Clay (SP -SC), brown, fine to
medium grained
Clayey Sand (SC), brown to orange, fine to medium
grained
Clayey Sand (SC), brown to orange, fine to medium
grained, some gravel
30 x/1%//1 Lean Clay (CL), brown to red
BOTTOM OF BOREHOLE AT 3.5 -ft
SOILS ARE FIELD VISUALLY CLASSIFIED IN
ACCORDANCE WITH THE UNIFIED SOIL
CLASSIFICATION SYSTEM
s -t
0.5•
S2
-1-1
1.5•
S-3
-2-1
2.5-
S-4
-3-1
S-5
�r Drafted By: Chris Norton, P.E. Reviewed By: Saul Carlson, E I
`. I. Date Drafted: 4/11/2017 Date Checked: 4/13/2017
Wilmington District VERSION: Final
Geotechnical and Dam Safety Section
SAW FORM 1836-A (SOIL BORING) Rorina Designation SOFTI-HA-17-4 SHEET 1 of 1
OCT 2013

DRILLING LOG South Atlantic Division
1.PROJECT
SOF JSOC Truck Inspection Point
2 HOLE NUMBER : LOCATION COORDINATES
SOFTI-HA-17-5 N 514949.798 E 1996811.152
3 DRILLING AGENCY
USACE, Wilmington District
4 NAME OF DRILLER
Chris Norton and Saul Carlson
5. DIRECTION OF BORING DEG FROM : BEARING
® VERTICAL : VERTICAL
Q INCLINED ---
6. THICKNESS OF OVERBURDEN
7 DEPTH DRILLED INTO ROCK
8. TOTAL DEPTH OF BORING 2.5 -ft
DEPTH SCALE LEGEND FIELD CLASSIFICATION OF MATERIALS
(feet) (feet) (Description)
a b c d
Boring Designation
SUI- I 1 -HA -1 t-5
INSTALLATION
Fort Bragg, NC
SHEET 1
�01` 1 SHEETS
9 COORDINATE SYSTEM
: HORIZONTAL
NAD83
VERTICAL
NAVD88
10 SIZE AND TYPE OF BIT
3"
11 MANUFACTURER'S DESIGNATION OF DRILL
12 TOTAL SAMPLES
DISTURBED : UNDISTURBED
3 0
13 TOTAL NUMBER CORE BOXES 0
14 ELEVATION GROUND WATER GWT depth In column "a"
:STARTED :COMPLETED
15 DATE BORING 2/27/17 2/27/17
16 ELEVATION TOP OF BORING Elevation from Attachment B
17 TOTAL CORE RECOVERY FOR BORING
18 SIGNATURE AND TITLE OF INSPECTOR
Chris Norton, P.E., Civil Engineer
BOX OR REMARKS
SAMPLE # (Drilling time, water loss, depth of
f weathering, etc, if significant)
9
Boring was acquired with a Hand Auger
(HA)
0.0 0 0 Poorly Graded Sand with Silt (SP -SM), brown, fine to
medium grained, non -plastic, little organics
Poorly Graded Sand with Clay (SP -SC), brown, fine to
medium grained
10
2,0 —V/// Lean Clay (CL), brown, fine to medium grained, roots
encountered at Bottom of Hole
BOTTOM OF BOREHOLE AT 2.5 -ft
SOILS ARE FIELD VISUALLY CLASSIFIED IN
ACCORDANCE WITH THE UNIFIED SOIL
CLASSIFICATION SYSTEM
S-1
.5-
s2
1-1
S3
Drafted By: Chris Norton, P.E. Reviewed By: Saul Carlson, E I
I' 'I Date Drafted: 4/11/2017 Date Checked: 4/13/2017
Wilmington Dls&ct VERSION: Final
Geotechnical and Dam Safety Section
SAW FORM 1836-A (SOIL BORING) Borina Desionation SOFTI-HA-17-5 SHEET 1 of 1
UL; 1 zul3

DRILLING LOG South Atlantic Division
1.PROJECT
SOF JSOC Truck Inspection Point
2. HOLE NUMBER LOCATION COORDINATES
SOFTI-HA-17-6 N 514826.044 E 1996936.661
3. DRILLING AGENCY
USACE, Wilmington District
4. NAME OF DRILLER
Chris Norton and Saul Carlson
5 DIRECTION OF BORING DEG FROM : BEARING
® VERTICAL : VERTICAL
0 INCLINED ---
6. THICKNESS OF OVERBURDEN
7. DEPTH DRILLED INTO ROCK
8. TOTAL DEPTH OF BORING 2.5 -ft
DEPTH SCALE LEGEND FIELD CLASSIFICATION OF MATERIALS
(feet) (feet) (Description)
a b c d
-2.0
0.0
1.0
2.0
Eloring Designation
5U[- I I -NA -1 !-b
INSTALLATION
Fort Bragg, NC
SHEET 1
�OF 1 SHEETS
9. COORDINATE SYSTEM
HORIZONTAL :
NAD83
VERTICAL
NAVD88
10. SIZE AND TYPE OF BIT
3"
11. MANUFACTURER'S DESIGNATION OF DRILL
12. TOTAL SAMPLES
: DISTURBED UNDISTURBED
4 0
13. TOTAL NUMBER CORE BOXES 0
14. ELEVATION GROUND WATER GWT depth in column "a"
:STARTED :COMPLETED
15. DATE BORING 2/27/17 2/27/17
16. ELEVATION TOP OF BORING Elevation from Attachment B
17. TOTAL CORE RECOVERY FOR BORING
18. SIGNATURE AND TITLE OF INSPECTOR
Chris Norton, P.E., Civil Engineer
BOX OR REMARKS
SAMPLE # (Drilling time, water loss, depth of
f weathering, etc , if significant)
9
Boring was acquired with a Hand Auger
(HA)
Poorly Graded Sand with Silt (SP -SM), brown, fine to
medium grained, non -plastic, little organics
Poorly Graded Sand with Clay (SP -SC), brown, fine to
medium grained
Clayey Sand (SC), brown to orange, fine to medium
grained
Clayey Sand (SC), brown to orange, fine to medium
grained, roots at bottom of hole
BOTTOM OF BOREHOLE AT 2.5 -ft
SOILS ARE FIELD VISUALLY CLASSIFIED IN
ACCORDANCE WITH THE UNIFIED SOIL
CLASSIFICATION SYSTEM
S-1
S-2
84
Drafted By: Chris Norton, P.E. Reviewed By: Saul Carlson, E I.
Date Drafted: 4/11/2017 Date Checked: 4/13/2017
Wllminglon Dlst►fct VERSION: Final
Geotechnical and Dam Safely SecBon
SAW FORM 1836-A (SOIL BORING) Borina Desianation SOFTI-HA-17-6 SHEET 1 of 1
UGI ZU13

DRILLING LOG I South Atlantic Division
1 PROJECT
SOF JSOC Truck Inspection Point
2 HOLE NUMBER : LOCATION COORDINATES
SOFTI-HA-17-7 N 514836.944 E 1997127.934
3 DRILLING AGENCY
USACE, Wilmington District
4. NAME OF DRILLER
Chris Norton and Saul Carlson
5. DIRECTION OF BORING : DEG FROM : BEARING
® VERTICAL : VERTICAL
Q INCLINED
6 THICKNESS OF OVERBURDEN
7 DEPTH DRILLED INTO ROCK
8. TOTAL DEPTH OF BORING 3.5 -ft
DEPTH SCALE LEGEND FIELD CLASSIFICATION OF MATERIALS
(feet) (feet) (Description)
a b c d
nation 5Ul- I I -HA -1 /-
RHi
Fort Bragg, NC I OF 1 SHEETS
9 COORDINATE SYSTEM HORIZONTAL VERTICAL
NAD83 NAVD88
10. SIZE AND TYPE OF BIT 3"
11 MANUFACTURER'S DESIGNATION OF DRILL
12 TOTAL SAMPLES : DISTURBED UNDISTURBED
3 0
13 TOTAL NUMBER CORE BOXES 0
14. ELEVATION GROUND WATER GWT depth in Column "a"
STARTED :COMPLETED
15. DATE BORING 2/27/17 2/27/17
16 ELEVATION TOP OF BORING Elevation from Attachment B
17 TOTAL CORE RECOVERY FOR BORING
18. SIGNATURE AND TITLE OF INSPECTOR
Chris Norton, P.E., Civil Engineer
BOX OR REMARKS
SAMPLE # (Drilling time, water loss, depth of
f weathering, etc , if significant)
9
Boring was acquired with a Hand Auger
(HA)
0.0 0 0 Poorly Graded Sand with Silt (SP -SM), brown, fine to
j].1medium grained, non -plastic, little organics
sf
Poorly Graded Sand with Clay (SP -SC), brown, fine to
medium grained
S-2
1.0
1-1
20
3.0 Clayey Sand (SC), brown to orange, fine to medium 3-1
grained
sa
BOTTOM OF BOREHOLE AT 3.5 -ft
SOILS ARE FIELD VISUALLY CLASSIFIED IN
ACCORDANCE WITH THE UNIFIED SOIL
CLASSIFICATION SYSTEM
Drafted By: Chris Norton, P.E. Reviewed By: Saul Carlson, E.1
Date Drafted: 4/11/2017 Date Checked: 4/13/2017
Wgmington District VERSION: Final
Geotechnical and Dam Safety Section
SAW FORM 1836-A (SOIL BORING) Boring Designation SOFTI-HA-17-7 SHEET 1 of 1
OCT 2013

DRILLING LOG South Atlantic Division
1 PROJECT
SOF JSOC Truck Inspection Point
2 HOLE NUMBER : LOCATION COORDINATES
SOFTI-HA-17-8 N 514736.305 E 1996629.486
3. DRILLING AGENCY
USACE, Wilmington District
4. NAME OF DRILLER
Chris Norton and Saul Carlson
5 DIRECTION OF BORING DEG FROM BEARING
® VERTICAL : VERTICAL
Q INCLINED ---
6. THICKNESS OF OVERBURDEN
7 DEPTH DRILLED INTO ROCK
8 TOTAL DEPTH OF BORING 6.5 -ft
DEPTH SCALE LEGEND FIELD CLASSIFICATION OF MATERIALS
(feet) (feet) (Description)
a b c d
-2.0
INSTALLATION SHEET 1
Fort Bragg, NC OF 1 sHEETs
9. COORDINATE SYSTEM : HORIZONTAL : VERTICAL
NAD83 NAVD88
10. SIZE AND TYPE OF BIT 3"
11 MANUFACTURER'S DESIGNATION OF DRILL
12. TOTAL SAMPLES DISTURBED : UNDISTURBED
0 0
13 TOTAL NUMBER CORE BOXES 0
14. ELEVATION GROUNDWATER GWT depth In column "a"
:STARTED COMPLETED
15. DATE BORING 2/28/17 2/28/17
16. ELEVATION TOP OF BORING Elevation from Attachment B
17. TOTAL CORE RECOVERY FOR BORING
18. SIGNATURE AND TITLE OF INSPECTOR
Chris Norton, P.E., Civil Engineer
BOX OR REMARKS
SAMPLE # (Drilling time, water loss, depth of
f weathering, etc, if significant)
9
Boring was acquired with a Hand Auger
(HA)
0.0 �i/Clayey Sand (SC), organg to brown, fine to medium
Il grained, some organics
1 0 � Poorly Graded Sand (SP), tan, fine to medium grained
20 rX111/J Clayey Sand (SC), tan, fine to medium grained
3.0
40
-4.5
5.0
-5.5
6.0
Clayey Sand (SC), tan to brown, fine to medium
grained, wet at 3.5 -feet
Clayey Sand (SC), tan to brown, GWT at 4.5 -feet
Poorly Graded Sand with Clay (SP -SC), tan to brown,
fine to medium grained, wet
BOTTOM OF BOREHOLE AT 6.5 -ft
SOILS ARE FIELD VISUALLY CLASSIFIED IN
ACCORDANCE WITH THE UNIFIED SOIL
CLASSIFICATION SYSTEM
Drafted By: Chris Norton, P.E. Reviewed By: Saul Carlson, E.1
Date Drafted: 4/11/2017 Date Checked: 4/13/2017
Wilmington District VERSION: Final
Geotechnical and Dam Safety Section
SAW FORM 1836-A (SOIL BORING) Boring Designation SOFTI-HA-17-8 SHEET 1 of 1
OCT 2013

ATTACHMENT D
CBR and UBC Tabulations

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7

Depth Depth
(in) (ft)
1 0.08
2 0.17
3 0.25
4 0.33
5 0.42
6 0.50
7 0.58
8 0.67
9 0.75
10 0.83
11 0.92
12 1.00
13 1.08
14 1.17
15 1.25
16 1.33
17 1.42
18 1.50
19 1.58
20 1.67
21 1.75
22 1.83
23 1.92
24 2.00
25 2.08
26 2.17
27 2.25
28 2.33
29 2.42
30 2.50
Boring ID:
SOFTI-DCP-1774
Elev.
Attachment A
Northing
514858.83100
Easting
1996646.76800
Capacity
(ft)
M
NAVD 88
CBR
Ultimate
Elevation
Bearing
1725
Capacity
(ft)
M
(psf)
4837
27
4837
4837
47
7072
4837
37
5991
5991
37
5991
4837
37
5991
3578
37
5991
4837
37
5991
5991
37
5991
7072
27
4837
9083
27
4837
9083
17
3578
9083
8
2137
14393
17
3578
14393
17
3578
17
3578
8
2137
17
3578
8
2137
8
2137
8
2137
8
2137
8
2137
6
1725
6
1725
6
1725
8
2137
8
2137
8
2137
8
2137
8
2137
Boring ID:
SOFTI-DCP-17-5
Elev.
Attachment A
Northing
514949.79800
Easting
1996811.15200
Capacity
(ft)
M
NAVD 88
CBR
Ultimate
Elevation
Bearing
1725
Capacity
(ft)
M
(Psfl
4837
8
2137
4837
8
2137
4837
6
1725
5991
6
1725
4837
4
1276
3578
4
1276
4837
4
1276
5991
4
1276
7072
6
1725
9083
8
2137
9083
27
4837
9083
47
7072
14393
69
9083
14393
69
9083
103
11842
91
10949
80
10031
80
10031
91
10949
80
10031
69
9083
69
9083
69
9083
69
9083
262
22052
193
17970
134
14106
134
14106
86
10488
86
10488
Boring ID:
SOFTI-DCP-17-6
Elev.
Attachment A
Northing
514826.04400
Easting
1996936.66100
NAVD 88
CBR
Ultimate
Elevation
Bearing
Capacity
(ft)
M
(psf)
6
1725
6
1725
8
2137
27
4837
27
4837
27
4837
37
5991
27
4837
17
3578
27
4837
37
5991
47
7072
69
9083
69
9083
69
9083
138
14393
138
14393
Notes: Top of hole depth is 0; Horizontal Datum is NC State Plane (US Survey Feet); Vertical Datum is NAVD88
and Elevation Top of Hole can be estimated from topography in Attachment B; DCP conforms to ASTM D6951;
CBR per ASTM D6951; Ultimate Bearing Capacity correlation per "Evaluation of In Situ Pavmement Layers with
the Dynamic Cone Penetrometer (DCP)", Jeb S. Tingle, et. al.
ATTnrwRAFNT n

Depth Depth
(in) (ft)
1 0.08
2 0.17
3 0.25
4 0.33
5 0.42
6 0.50
7 0.58
8 0.67
9 0.75
10 0.83
11 0.92
12 1.00
13 1.08
14 1.17
15 1.25
16 1.33
17 1.42
18 1.50
19 1.58
20 1.67
21 1.75
22 1.83
23 1.92
24 2.00
25 2.08
26 2.17
27 2.25
28 2.33
29 2.42
30 2.50
31 2.58
32 2.67
33 2.75
34 2.83
35 2.92
36 3.00
Boring ID:
SOFTI-DCP-17-7
Elev.
Attachment A
Northing
514836.94400
Easting
1997127.93400
1996805.17100
NAVD 88
CBR
Ultimate
Elevation
Elevation
Bearing
Bearing
Capacity
(ft)
M
(psf)
(psf)
17
3578
3578
17
3578
3578
17
3578
4837
17
3578
9083
17
3578
16796
17
3578
12711
8
2137
10031
17
3578
8099
8
2137
7072
17
3578
7072
17
3578
4837
17
3578
5991
27
4837
4837
17
3578
4837
17
3578
4837
27
4837
3578
27
4837
4837
27
4837
4837
17
3578
4837
27
4837
3578
27
4837
4837
27
4837
3578
37
5991
3578
47
7072
3578
47
7072
4837
47
7072
3578
47
7072
3578
47
7072
2137
47
7072
2137
47
7072
DCP ID:
SOFTI-DCP-17-8
Elev.
Attachment A
Northing
514917.04400
514877.00800
Easting
1996805.17100
NAVD 88
CBR
Ultimate
Elevation
Bearing
Capacity
(ft)
M
(psf)
17
3578
17
3578
27
4837
69
9083
174
16796
114
12711
80
10031
58
8099
47
7072
47
7072
27
4837
37
5991
27
4837
27
4837
27
4837
17
3578
27
4837
27
4837
27
4837
17
3578
27
4837
17
3578
17
3578
17
3578
27
4837
17
3578
17
3578
8
2137
8
2137
8
2137
8
2137
17
3578
17
3578
8
2137
8
2137
8
2137
DCP ID:
SOFTI-DCP-17-9
Elev.
Attachment
A
Northing
514877.00800
Easting
1996829.07600
NAVD 88
CBR
Ultimate
Elevation
Bearing
Capacity
(ft)
M
(psf)
8
2137
37
5991
47
7072
37
5991
17
3578
27
4837
27
4837
17
3578
17
3578
27
4837
17
3578
17
3578
8
2137
8
2137
8
2137
17
3578
8
2137
8
2137
8
2137
17
3578
8
2137
17
3578
17
3578
8
2137
8
2137
17
3578
8
2137
17
3578
8
2137
8
2137
8
2137
17
3578
17
3578
8
2137
8
2137
8
2137
Notes: Top of hole depth is 0; Horizontal Datum is NC State Plane (US Survey Feet); Vertical Datum is
NAVD88 and Elevation Top of Hole can be estimated from topography in Attachment B; DCP conforms to
ASTM D6951; CBR per ASTM D6951; Ultimate Bearing Capacity correlation per "Evaluation of In Situ
Pavmement Layers with the Dynamic Cone Penetrometer (DCP)", Jeb S. Tingle, et. al.
ATTArwhAFNT n

ATTACHMENT E
Infiltration Test Tabulations

Observation Time Elapse Water Level Infiltration
Start End Time from Top of Pipe Rate
SOFTI-INF-17-1
9:15
(min)
(in)
(in)
tin/nr)
SOFTI-INF-17-2
9:10
9:40
30
0.00
7.50
15.0
2.0
9:40
9:50
10
7.50
9.25
10.5
9:50
10:00
10
9.25
11.00
10.5
35.16437 N
10:00
10:10
10
11.00
12.50
9.0
79.01133 W
10:10
10:40
30
12.50
17.00
9.0
SOFTI-INF-17-1
9:15
9:30
15
35.5
36.5
4.0
9:30
9:45
15
36.5
37
2.0
additional water
added to pipe
35.16420 N
9:49
9:59
10
33.5
35.75
13.5
79.01125 W
9:59
10:09
10
35.75
36.25
3.0
10:09
10:19
10
36.25
36.5
1.5
10:19
10:29
10
36.5
36.75
1.5
10:29
10:39
10
36.75
37
1.5
ATTACHMENT E

ATTACHMENT F
Michigan Method — Soil Infiltration Testing

i
Appendix E
Soil Infiltration Testing Protocol
Purpose of this Protocol
The soil infiltration testing protocol describes evaluation
and field testing procedures to determine if infiltration
BMPs are suitable at a site, as well as to obtain the
required data for infiltration BMP design.
When to Conduct Testing
The Site Design Process for LID, outlined in Chapter 5
of this manual, describes a process for site development
and application of nonstructural and structural BMPs. It
is recommended that soil evaluation and investigation
be conducted following development of a concept plan
or early in the development of a preliminary plan.
Who Should Conduct Testing
Soil evaluation and investigation may be conducted
by soil scientists, local health department sanitarians,
design engineers, professional geologists, and other
qualified professionals and technicians. The stormwater
designer is strongly encouraged to directly observe the
testing process to obtain a first-hand understanding of
site conditions.
Importance of Stormwater BMP
Areas
Sites are often defined as unsuitable for infiltration
BMPs and soil -based BMPs due to proposed grade
changes (excessive cut or fill) or lack of suitable areas.
Many sites will be constrained and unsuitable for infil-
tration BMPs. However, if suitable areas exist, these
areas should be identified early in the design process
and should not be subject to a building program that
precludes infiltration BMPs. Full build -out of site areas
otherwise deemed to be suitable for infiltration should
not provide an exemption or waiver for adequate storm -
water volume control or groundwater recharge.
Safety
As with all field work and testing, attention to all appli-
cable Occupational Safety and Health Administration
(OSHA) regulations and local guidelines related to
earthwork and excavation is required. Digging and
excavation should never be conducted without adequate
notification through the Michigan One Call system
(Miss Dig www.missdig.net or 1-800-482-7171). Exca-
vations should never be left unsecured and unmarked,
and all applicable authorities should be notified prior to
any work.
Infiltration Testing:
A Multi -Step Process
Infiltration testing is a four -step process to obtain the
necessary data for the design of the stormwater manage-
ment plan. The four steps include:
1. Background evaluation
• Based on available published and site specific
data
• Includes consideration of proposed development
plan
Used to identify potential BMP locations and
testing locations
• Prior to field work (desktop)
2. Test pit (deep hole) observations
• Includes multiple testing locations
• Provides an understanding of sub -surface
conditions
• Identifies limiting conditions
3. Infiltration testing
• Must be conducted onsite
• Different testing methods available
4. Design considerations
• Determine suitable infiltration rate for design
calculations
• Consider BMP drawdown
• Consider peak rate attenuation
ATTACHMENT F

C ( +
Step 1. Background evaluation
Prior to performing testing and developing a detailed
site plan, existing conditions at the site should be inven-
toried and mapped including, but not limited to:
• Existing mapped soils and USDA Hydrologic Soil
Group classifications.
• Existing geology, including depth to bedrock, karst
conditions, or other features of note.
• Existing streams (perennial and intermittent,
including intermittent swales), water bodies,
wetlands, hydric soils, floodplains, alluvial soils,
stream classifications, headwaters, and first order
streams.
• Existing topography, slope, drainage patterns, and
watershed boundaries.
• Existing land use conditions.
• Other natural or man-made features or conditions
that may impact design, such as past uses of site,
existing nearby structures (buildings, walls),
abandoned wells, etc.
• A concept plan or preliminary layout plan for
development should be evaluated, including:
• Preliminary grading plan and areas of cut and
fill,
• Location of all existing and proposed water
supply sources and wells,
• Location of all former, existing, and proposed
onsite wastewater systems,
• Location of other features of note such as utility
rights-of-way, water and sewer lines, etc.,
• Existing data such as structural borings, and
• Proposed location of development features
(buildings, roads, utilities, walls, etc.).
In Step 1, the designer should determine the potential
location of infiltration BMPs. The approximate location
of these BMPs should be on the proposed development
plan and serve as the basis for the location and number
of tests to be performed onsite.
Important. If the proposed development is located on
areas that may otherwise be a suitable BMP location,
or if the proposed grading plan is such that potential
BMP locations are eliminated, the designer is strongly
encouraged to revisit the proposed layout and grading
plan and adjust the development plan as necessary. Full
build -out of areas suitable for infiltration BMPs should
not preclude the use of BMPs for runoff volume reduc-
tion and groundwater recharge.
Step 2. Test pits (deep holes)
A test pit (deep hole) allows visual observation of the
soil horizons and overall soil conditions both hori-
zontally and vertically in that portion of the site. An
extensive number of test pit observations can be made
across a site at a relatively low cost and in a short time
period. The use of soil borings as a substitute for test
pits is strongly discouraged, as visual observation is
narrowly limited in a soil boring and the soil horizons
cannot be observed in-situ, but must be observed from
the extracted borings.
A test pit (deep hole) consists of a backhoe -excavated
trench, 2'/2-3 feet wide, to a depth of 6-7'/z feet, or until
bedrock or fully saturated conditions are encountered.
The trench should be benched at a depth of 2-3 feet for
access and/or infiltration testing.
At each test pit, the following conditions are to be noted
and described. Depth measurements should be described
as depth below the ground surface:
• Soil horizons (upper and lower boundary),
• Soil texture, structure, and color for each horizon,
• Color patterns (mottling) and observed depth,
• Depth to water table,
• Depth to bedrock,
• Observance of pores or roots (size, depth),
• Estimated type and percent coarse fragments,
• Hardpan or limiting layers,
• Strike and dip of horizons (especially lateral
direction of flow at limiting layers), and
• Additional c6mments or observations.
The Sample Soil Log Form at the end of this protocol
may be used for documenting each test pit.
At the designer's discretion, soil samples may be
collected at various horizons for additional analysis.
Following testing, the test pits should be refilled with the
original soil and the topsoil replaced. A test pit should
never be accessed if soil conditions are unsuitable or
unstable for safe entry, or if site constraints preclude
entry. OSHA regulations should always be observed.
ATTACHMENT F

l ( r
It is important that the test pit provide information
related to conditions at the bottom of the proposed
infiltration BMP. If the BMP depth will be greater than
90 inches below existing grade, deeper excavation of
the test pit will be required. The designer is cautioned
regarding the proposal of systems that are significantly
deeper than the existing topography, as the suitability
for infiltration is likely to decrease. The design engineer
is encouraged to consider reducing grading and earth-
work as needed to reduce site disturbance and provide
greater opportunity for stormwater management.
The number of test pits varies depending on site condi-
tions and the proposed development plan. General
guidelines are as follows:
• For single-family residential subdivisions with
on -lot infiltration BMPs, one test pit per lot is
recommended, preferably within 100 feet of the
proposed BMP area.
• For multi -family and high-density residential
developments, one test pit per BMP area or acre is
recommended.
• For large infiltration areas (basins, commercial,
institutional, industrial, and other proposed land
uses), multiple test pits should be evenly distributed
at the rate of four to six pits per acre of BMP area.
The recommendations above are guidelines. Additional
tests should be conducted if local conditions indicate
significant variability in soil types, geology, water table
levels, depth and type of bedrock, topography, etc. Simi-
larly, uniform site conditions may indicate that fewer
test pits are required. Excessive testing and disturbance
of the site prior to construction is not recommended.
Step 3. Infiltration tests
A variety of field tests exists for determining the infil-
tration capacity of a soil. Laboratory tests are not
recommended, as a homogeneous laboratory sample
does not represent field conditions. Infiltration tests
should be conducted in the field. Infiltration tests
should not be conducted in the rain, within 24 hours
of significant rainfall events (>0.5 inches), or when the
temperature is below freezing.
At least one test should be conducted at the proposed
bottom elevation of an infiltration BMP, and a mini-
mum of two tests per test pit are recommended. Based
on observed field conditions, the designer may elect to
modify the proposed bottom elevation of a BMP. Person-
nel conducting infiltration tests should be prepared to
adjust test locations and depths depending on observed
conditions.
Methodologies discussed in this protocol include:
• Double -ring infiltrometer tests.
• Percolation tests (such as for onsite wastewater
systems).
There are differences between the two methods. A
double -ring infiltrometer test estimates the vertical
movement of water through the bottom of the test area.
The outer ring helps to reduce the lateral movement of
water in the soil from the inner ring. A percolation test
allows water movement through both the bottom and
sides of the test area. For this reason, the measured rate
of water level drop in a percolation test must be adjusted
to represent the discharge that is occurring on both the
bottom and sides of the percolation test hole.
Other testing methodologies and standards that are
available but not discussed in detail in this protocol
include (but are not limited to):
• Constant head double -ring infiltrometer.
• Testing as described in the Maryland Stormwater
Manual, Appendix D.1, using five -inch diameter
casing.
• ASTM 2003 Volume 4.08, Soil and Rock (I):
Designation D 3385-03, Standard Test Method for
Infiltration Rate of Soils in Field Using a Double -
Ring Infiltrometer.
• ASTM 2002 Volume 4.09, Soil and Rock (II):
Designation D 5093-90, Standard Test Method
for Field Measurement of Infiltration Rate Using
a Double -Ring Infiltrometer with a Sealed -Inner
Ring.
• Guelph permeameter.
• Constant head permeameter (Amoozemeter).
LID'Manual for Midiiaan `Apliend�z E i s � Page 439.".
ATTACHMENT F

Methodology for double -ring infiltrometer field test
A double -ring infiltrometer consists of two concentric
metal rings. The rings are driven into the ground and
filled with water. The outer ring helps to prevent diver-
gent flow. The drop-in water level or volume in the
inner ring is used to calculate an infiltration rate. The
infiltration rate is the amount of water per surface area
and time unit which penetrates the soils. The diameter
of the inner ring should be approximately 50-70 percent
of the diameter of the outer ring, with a minimum inner
ring size of four inches. Double -ring infiltrometer test-
ing equipment designed specifically for that purpose
may be purchased. However, field testing for storm -
water BMP design may also be conducted with readily
available materials.
Equipment for double -ring infiltrometer test:
Two concentric cylinder rings six inches or greater
in height. Inner ring diameter equal to 50-70 percent
of outer ring diameter (i.e., an eight -inch ring and a
12 -inch ring). Material typically available at a hardware
store may be acceptable.
• Water supply,
• Stopwatch or timer,
• Ruler or metal measuring tape,
• Flat wooden board for driving cylinders uniformly
into soil,
• Rubber mallet, and
• Log sheets for recording data.
four inches. The drop in the water level during the
last 30 minutes of the presoaking period should be
applied to the following standard to determine the
time interval between readings:
If water level drop is two inches or more, use
10 -minute measurement intervals.
If water level drop is less than two inches, use
30 -minute measurement intervals.
Obtain a reading of the drop in water level in the
center ring at appropriate time intervals. After each
reading, refill both rings to water level indicator
mark or rim. Measurement to the water level in the
center ring should be made from a fixed reference
point and should continue at the interval determined
until a minimum of eight readings are completed or
until a stabilized rate of drop is obtained, whichever
occurs first. A stabilized rate of drop means a
difference of/a inch or less of drop between the
highest and lowest readings of four consecutive
readings.
The drop that occurs in the center ring during the
final period or the average stabilized rate, expressed
as inches per hour, should represent the infiltration
rate for that test location.
Methodology for percolation test
Equipment for percolation test
• Post hole digger or auger,
• Water supply,
• Stopwatch or timer,
Procedure for double -ring infiltrometer test • Ruler or metal measuring tape,
• Prepare level testing area. • Log sheets for recording data,
• Place outer ring in place; place flat board on ring
and drive ring into soil to a minimum depth of two
inches.
• Place inner ring in center of outer ring; place flat
board on ring and drive ring into soil a minimum of
two inches. The bottom rim of both rings should be
at the same level.
• The test area should be presoaked immediately
prior to testing. Fill both rings with water to water
level indicator mark or rim at 30 -minute intervals
for one hour. The minimum water depth should be
• Knife blade or sharp -pointed instrument (for soil
scarification),
• Course sand or fine gravel, and
• Object for fixed -reference point during
measurement (nail, toothpick, etc.).
ATTACHMENT F

L '% V.
Procedure for percolation test
This percolation test methodology is based largely on
the criteria for onsite sewage investigation of soils. A
24-hour pre-soak is generally not required as infiltra-
tion systems, unlike wastewater systems, will not be
continuously saturated.
• Prepare level testing area.
Prepare hole having a uniform diameter of 6-10
inches and a depth of 8-12 inches. The bottom and
sides of the hole should be scarified with a knife
blade or sharp -pointed instrument to completely
remove any smeared soil surfaces and to provide
a natural soil interface into which water may
percolate. Loose material should be removed from
the hole.
• (Optional) Two inches of coarse sand or fine gravel
may be placed in the bottom of the hole to protect
the soil from scouring and clogging of the pores.
Test holes should be presoaked immediately prior
to testing. Water should be placed in the hole to a
minimum depth of six inches over the bottom and
readjusted every 30 minutes for one hour.
The drop in the water level during the last 30
minutes of the final presoaking period should be
applied to the following standard to determine the
time interval between readings for each percolation
hole:
o If water remains in the hole, the interval for
readings during the percolation test should be 30
minutes.
If no water remains in the hole, the interval
for readings during the percolation test may be
reduced to 10 minutes.
After the final presoaking period, water in the hole
should again be adjusted to a minimum depth of
six inches and readjusted when necessary after
each reading. A nail or marker should be placed at
a fixed reference point to indicate the water refill
level. The water level depth and hole diameter
should be recorded.
Measurement to the water level in the individual
percolation holes should be made from a fixed
reference point and should continue at the interval
determined from the previous step for each
individual percolation hole until a minimum of
eight readings are completed or until a stabilized
rate of drop is obtained, whichever occurs first.
A stabilized rate of drop means a difference of
inch or less of drop between the highest and lowest
readings of four consecutive readings.
The drop that occurs in the percolation hole during
the final period, expressed as inches per hour,
should represent the percolation rate for that test
location.
The average measured rate must be adjusted to
account for the discharge of water from both
the sides and bottom of the hole and to develop
a representative infiltration rate. The average/
final percolation rate should be adjusted for each
percolation test according to the following formula:
Infiltration Rate = (Percolation Rate)/(Reduction
Factor)
Where the Reduction Factor is given by**:
R_ 2d1—Ad+l
f DIA
With:
d, = Initial Water Depth (in.)
Ad = Average/Final Water Level Drop (in.)
DIA = Diameter of the Percolation Hole (in.)
The percolation rate is simply divided by the reduc-
tion factor as calculated above or shown in Table E.1
below to yield the representative infiltration rate. In
most cases, the reduction factor varies from about two
to four depending on the percolation hole dimensions
and water level drop — wider and shallower tests have
lower reduction factors because proportionately less
water exfiltrates through the sides.
** The area reduction factor accounts for the exfiltra-
tion occurring through the sides of percolation hole. It
assumes that the percolation rate is affected by the depth
of water in the hole and that the percolating surface
of the hole is in uniform soil. If there are significant
problems with either of these assumptions then other
adjustments may be necessary.
ATTACHMENT F