HomeMy WebLinkAboutSW4200703_Hawbridge School_SE_20200708
Tai and Associates, PLLC
P.O. Box 90067 Raleigh, NC 27675 (919) 782-9525 www.taiandassociates.com
SUBSURFACE EXPLORATION REPORT
Conducted On:
Hawbridge School
Saxapahaw, North Carolina
Tai Job No. 18-196-1
For:
The Hawbridge School
1735 Saxapahaw-Bethlehem Church Road
Saxapahaw, North Carolina
March 20, 2019
Prepared By:
Tai and Associates, PLLC
NC Firm License No. P-0370
_________________________________
Matthew T. Ryan, PE
Tai and Associates, PLLC
P.O. Box 90067 Raleigh, NC 27675 (919) 782-9525 www.taiandassociates.com
March 20, 2019
Ms. Mya Ciccotti Geiss
Interim Executive Director
The Hawbridge School
1735 Saxapahaw-Bethlehem Church Road
Saxapahaw, North Carolina 27340
Re: Subsurface Exploration Report
Hawbridge School
Saxapahaw, North Carolina
Tai Job No.: 18-196-1
Dear Ms. Ciccotti Geiss:
In accordance with your authorization, we have completed a subsurface exploration program for the
referenced project. This program consisted of the drilling of twenty-three (23) soil borings, visual
classification of soil samples recovered, site visit, engineering services, analyses of subsurface conditions,
and the preparation of this written report.
FIELD EXPLORATION
The field exploration program consisted of the drilling of twenty-three (23) soil borings (B-1 through
B-23) advanced to a maximum depth of 42.0 feet below the existing ground surface. The drilling was
performed by a CME 550 drill rig using 2-¼” inside diameter hollow stem augers to advance the soil borings.
Standard Penetration Tests (ASTM D-1586) were performed at every 2.5-foot interval to 10.0 feet below
ground surface, followed by one at every 5.0-foot interval utilizing an auto-hammer.
The approximate locations and logs of the soil borings are shown on the attached “Boring Location
Plan” and “Boring Logs”. The boring locations were staked by measuring from existing site features and
should be considered approximate. Boring elevations were interpolated from an Existing Conditions and
Demolition Plan prepared by Little, dated December 12, 2018, and should also be considered approximate.
LABORATORY TESTING
The laboratory-testing program consisted of the visual classification of all soil samples recovered
(ASTM D-2488). The descriptions of the subsurface materials as represented by the soil samples recovered
are indicated on the “Boring Logs.” All samples will be discarded in 60 days unless otherwise instructed.
SITE OBSERVATION
The site is predominantly cleared and vegetated with grass. The site topography is lowest at the
eastern part of the site, at an elevation of approximately 454.0, and highest at the western part of the site, at
an elevation of approximately 515.0.
Ms. Mya Ciccotti Geiss
Tai Job No. 18-196-1
March 20, 2019
Page 2 of 8
SUBSURFACE CONDITIONS
Based on the results of the field exploration program, the subsurface materials of the project site can
be described as consisting of the following units of soil:
1. Topsoil: Topsoil, encountered in sixteen (16) soil borings at the site, was 1.0 to 2.0 inches
thick. At boring B-15, 6.0 inches of topsoil was encountered.
2. Possible Fill Soil: Possible fill soil was encountered in borings B-15 and B-17 to a depth of
about 5.5 feet below the ground surface. This unit of soil consists of soft to firm, clayey silt
with gravel, roots and variable amounts of sand. This unit of soil is of poor engineering
quality.
3. Residual Soil: Below the topsoil and fill soil is natural, residual soil derived from the in-
place weathering of the parent rock. This is the predominant subsurface material found at
the site and it is found in all of the soil borings. It generally comprises silty clays, clayey
silts, and sandy silts.
a. The shallower portions of the residuum consist mostly of red silty clays and clayey silts
to a depth of 3.0 to 32.0 feet, but mostly 5.0 to 10.0 feet below ground surface. SPT N-
Values for this soil were 5 to 33 (firm to hard). This soil is of a moderate engineering
quality.
b. The residual soils become less cohesive with depth. Silts and sandy silts were
encountered below the clayey soils. Generally tan, orange, brown, gray in color, this
unit of soil was stiff to very hard (SPT N-Values of 14 to 55). This soil is of a moderate
engineering quality.
4. Possible Boulder Material: Possible boulder material was encountered in borings B-1
through B-3 at depths of 17.0 to 22.0 feet below ground surface. Shallow rock ledges,
boulders, and boulder clusters probably exist elsewhere on site between borings.
5. Weathered Rock: Defined by material having a SPT N-Value of 50 blows per foot (bpf) or
more, weathered rock was encountered from 12.0 to 15.0 feet below ground surface at boring
B-8, 17.0 to 25.0 feet at borings B-16 and B-22, and from 32.0 to 35.0 feet at boring B-2.
This unit of soil is of good engineering quality, and the depth to this material is sporadic
based on previous experience.
6. Partially Weathered Rock: Some of the weathered rock becomes much harder with depth
and is classified as partially weathered rock (PWR). For this project, PWR is defined as very
hard, rock-like material having a N-Value of 50 blows over two inches or less. PWR was
encountered in boring B-2 at a depth of 37.0 feet below ground surface.
Ms. Mya Ciccotti Geiss
Tai Job No. 18-196-1
March 20, 2019
Page 3 of 8
7. Auger Refusal: Auger refusal was encountered at a depth of 42.0 feet below ground surface
at boring location B-2.
8. Groundwater: Groundwater was encountered in borings B-2, B-15 and B-22 at depths
ranging from 8.0 to 25.4 feet below the ground surface and likely exists elsewhere between
the borings at varying elevations.
PROPOSED PROJECT
Based on correspondence with the design team, we understand that the proposed project consists of
the design and construction of a two-story school building, stormwater detention ponds, above-ground
parking areas, and the related infrastructure. The preliminary finish floor elevation for the upper level of the
new building is 484.0 (near borings B-5, B-6, and B-9) and for the lower level is 472.0. Foundation loading
is unknown, but for preliminary planning purposes we anticipate maximum column loads to be in the order
of 200 kips. Up to 20.0 feet of cut and 7.0 feet of fill will be required to reach proposed grade at the site.
RECOMMENDATIONS
Foundations
We recommend the proposed building be supported on single, combined, or continuous footings
designed for the net allowable bearing pressure (net contact pressure) shown below. The net allowable
bearing pressure refers to the pressure which may be transmitted to the foundation bearing material in excess
of the final surrounding overburden pressure. All footings shall be supported on firm or stiff residual soils,
new controlled fill, or an improved subgrade. The estimated maximum total and differential post-
construction settlement is 1.0 and 0.5 inches, respectively.
Building Net Allowable Bearing Capacity Soil Bearing Condition
1 to 2-Story 3,000 psf Up to 250-kip column loads
If it proves beneficial, a higher bearing capacity of 4,000 psf can be achieved in the areas at the
project site with at least 4.0 feet of cut to reach proposed finish floor elevation.
All footing subgrades must be inspected for the design bearing capacity by a professional engineer
or their representative utilizing field engineering judgment. Expansion joints should be provided on the
exterior walls at regular intervals and at every building break. There should be at least 12.0 inches of cover
on all exterior footings to prevent frost penetration. All foundation systems should be designed at an
elevation that no utility lines, utility line excavation, and any other footings are located within a 1:1 zone of
influence of the subject footing edge. See attachment for estimated settlement calculation.
Ms. Mya Ciccotti Geiss
Tai Job No. 18-196-1
March 20, 2019
Page 4 of 8
Excavation
All normal size earth-moving equipment can easily move the materials encountered above the
boulder material and weathered rock layer. Normally, slow excavation with a large hydraulic excavator such
as a CAT 330 track-mounted hydraulic excavator, or equal, should be able to excavate any hard or dense
soils. Weathered rock cannot be excavated with a rubber-tire backhoe or a small track-mounted excavator
such as a mini-excavator.
Rock excavation should be defined as material that cannot be excavated with a track-mounted
hydraulic excavator, equipped with rock teeth, equivalent to a CAT 330. Boulders exceeding 1.0 cy in mass
excavations and 0.75 cy in trench excavations should also be classified as rock. The contract should include
definitions for mass rock and trench rock.
Some rock excavation in the form of boulders in deep cut areas are common for the geology, and are
present in one boring near proposed grades (B-1). When a grading plan becomes available, we would be
pleased to provide an estimated volume of rock excavation.
Cut and Fill
It appears that up to 20.0 of cut and 7.0 feet of fill will be required to reach proposed grades for the
proposed building, roads and parking areas at the site. A two (2) horizontal to one (1) vertical cut or fill,
temporary or permanent slope should offer sufficient margin of safety for global stability in any area not
protected by a shoring system. Cut and fill slopes not confined by retaining walls should start a minimum of
8.0 feet from the edge of the building and 5.0 feet from paved areas.
Most of the natural, non-plastic residual soils in the cut areas should provide suitable regular backfill
material, except for any clay pockets or boulders larger than 6.0 inches in any dimension. The existing on-
site fill soils are not considered suitable for reuse as fill. All fill and any backfill should be placed on cleared,
natural soil. Fill and backfill soils should consist of clean, sandy, silty natural residual soil, or approved off-
site borrow, placed in 8.0-inch loose lifts, and compacted to 98% of the Standard Proctor Density (ASTM D-
698). The moisture content of the fill during placement should be maintained to within ±2% of the optimum
value. In-place density tests should be performed at a rate of one test per 2,500 sf, per lift, per day (ASTM
D-1556).
Retaining wall backfills in excess of 12.0 feet in depth are difficult or impossible to accomplish
without settlement of the backfill relative to the building foundation or pavement areas. The design should
take this into account. This settlement can be substantially reduced by utilizing select granular borrow such
as quarry screenings with less than 15% passing the #200 sieve.
Seismic Classification
The project site subsoil belongs to seismic Site Class D, as determined in accordance with equation
16-41 of the 2012 North Carolina Building Code.
Ms. Mya Ciccotti Geiss
Tai Job No. 18-196-1
March 20, 2019
Page 5 of 8
Retaining Walls
We recommend that either a layer of prefabricated drainage material such as Enkadrain or 2-foot
wide layer of free-draining, granular material (such as #57 washed stone) be used as backfill for the entire,
below-grade face of site concrete retaining walls. Filter fabric (Mirafi 140N or equal) should be used to
separate the #57 stone from the regular soil backfill to avoid losing fines into the void spaces. The retaining
walls with top support should be designed against an at-rest equivalent fluid pressure. The retaining walls
without top support, if any, should be designed against an active equivalent fluid pressure. Perimeter
foundation drains should be installed behind the walls and connected to the storm drain system by gravity or
by pump. All other soil backfill must be placed in 8.0-inch thick loose layers and compacted to 98% of the
maximum Standard Proctor Density (ASTM D-698), within ±2% of the optimum moisture content.
The following soil parameters should be used in analyzing the stability of the wall and footing:
(φ) Friction angle 28 deg.
(γ) Unit weight 105 pcf
ka (Active earth pressure coefficient) 0.361
ko (At-rest earth pressure coefficient) 0.531
kp (Passive earth pressure coefficient) 2.770
ka (Equivalent active earth pressure) 38 pcf
ko (Equivalent at-rest earth pressure) 56 pcf
kp (Equivalent passive earth pressure) 291 pcf
Sliding Friction of Coefficient at Base 0.45
Segmental Retaining Walls
If segmental retaining walls are utilized as part of this project, these walls would normally be
designed on a design-build basis after the general contract has been awarded. As such, the reinforced backfill
zone cannot be specified until after the contract has been awarded. For planning purposes, we recommend
budgeting for import of all reinforced backfill soils because most or all of the on-site soils will contain more
than 50% fines, and will not consist of free-draining material.
Slabs
The building floor slabs can be designed as slab-on-grade over a well-prepared subgrade. The slabs
should be constructed over 4.0 inches of compacted NCDOT ABC stone or #57 stone. The slabs should be
isolated from the walls and columns. ACI 301.2 indicates that a contraction joint spacing of 24 to 36 times
the slab thickness up to a maximum spacing of 18.0 feet have produced acceptable results for unreinforced,
plain concrete slabs.
Ms. Mya Ciccotti Geiss
Tai Job No. 18-196-1
March 20, 2019
Page 6 of 8
Groundwater
Groundwater was encountered in three soil borings at depths ranging from 8.0 to 25.4 feet below
ground surface (elevation 459.0 to 453.0). Perched or trapped groundwater will likely be present at the site,
particularly during/following heavy rainfall periods. The site subgrade will be nearly impermeable. The
design of the building and development of the site must take this into account. The site should be graded to
divert surface water away from the building and a foundation drain tied to the storm drain system should be
installed around the entire building perimeter and behind all below-grade retaining walls. Waterproofing and
drain board should be installed behind all below-grade walls.
Utilities
All utility pipes should be supported on top of at least 6.0 inches of free-draining granular material.
The backfill should consist of clean natural soil, or suitable fill, and should be compacted to 98% of the
Standard Proctor Density (ASTM D-698), within 2% of the optimum moisture content.
Pavement
The pavement system should be supported on a carefully prepared site subgrade. Based on the NC
DOT Interim Pavement Design Procedure, and assumed soaked CBR Value of 6.0, the pavement system
should be as outlined below. The subgrade and the ABC stone base course should be inspected, tested and
proofrolled prior to placement of the subsequent lift.
ABC Stone I-19.0B Asphalt S-9.5B Asphalt Eq. 18,000 lb. Axle Trips /
Day
Light Duty 8 2.0 Cars only
Intermediate Duty 8 3.0 3.7
Heavy Duty 8 2.5 1.5 9.9
CONSTRUCTION CONSIDERATIONS
Engineering Behavior of Soils
The on-site silty-clayey soils are sensitive to surface water damage. Grading operations performed
in the wet winter months of November through March will be difficult, time consuming and expensive. Stiff
natural silty soils, if kept dry, will provide an adequate subgrade to placement of additional fill. However,
upon excavation even some of these soils can become unsuitable if they become wet.
Grading
The project site should be cleared of all the existing surface features such as topsoil, trees and other
vegetation, debris, etc. Most of the natural, non-plastic residual soil excavated can be reused as structural fill
Ms. Mya Ciccotti Geiss
Tai Job No. 18-196-1
March 20, 2019
Page 7 of 8
if the moisture content is maintained with 2% of the optimum moisture content. Any existing fill, plastic
clays, wet clays, or soft soils will not likely be suitable for re-use as structural fill.
Surface water control measures must be placed prior to any grading and earthwork activity. The
cleared site should be carefully proofrolled and inspected to identify any soft soil, existing fill soil, plastic
soils, or other unsuitable soil that requires undercutting. Should plastic soils be encountered, these may
require undercut and/or placement of separation geofabric (Mirafi 500X, or equal).
The on-site soils are difficult to work with. The low density, clayey-silty soil can be difficult to
maintain near the optimum moisture, and some pumping is occasionally observed during fill placement and
compaction, even when achieving the desired compaction density. Field engineering judgement will be
required by the geotechnical engineer to verify the suitability of the on-site soils for re-use as structural fill
during grading.
Shallow Foundations
The foundation excavation not poured immediately should be covered by a 3.0-inch thick mud slab
to protect from surface water damage. All footing subgrades must be inspected and approved for the required
bearing capacity by a representative of this firm utilizing field engineering judgment. Footing undercut
should be backfilled with lean concrete or other material approved by the geotechnical engineer.
Pavement and Slab Subgrades
Inspection of the asphalt pavement system subgrade and ABC stone subbase will be required. Some
additional improvement may be required including undercutting and/or placement of Mirafi 500X geofabric
due to existing fill, soft soils, plastic clays, or areas damaged by surface water and construction traffic.
ADDITIONAL SERVICES
Based on our experience working on projects similar to the Hawbridge School project, revisions and
modifications may be necessary as the design progresses. The foundation and earthwork design
recommendations presented in this report are based not only on our field and laboratory test results, but also
on the limited preliminary project information currently available to us. As the design progresses and
revisions are made, or when the final design becomes available, we would be pleased to have the opportunity
to review the plans and specifications, or to provide any additional consultation services.
FIELD SERVICES
All earthwork, foundation, slab, pavement, and utility construction activities should be observed by
one of our experienced engineers or geotechnicians to ensure that the actual subsurface conditions
encountered during construction are consistent with the design intent, and that the intended design
considerations are met in every phase of the earthwork and foundation construction. Some modification of
the design recommendations presented in this report may be required and any such changes must be verified
Ms. Mya Ciccotti Geiss
Tai Job No. 18-196-1
March 20, 2019
Page 8 of 8
by this firm. We cannot be held for the conditions stated above and the post-construction performance of the
foundation and pavement systems unless we are authorized to perform the field services required.
CLOSURE
It has been a pleasure to work with you and your design team on the preliminary phase of this project.
If you have any questions, or if we can offer any additional information or services during the design phase
of this project, please feel free to call us at your convenience.
Very Truly Yours,
Tai and Associates, PLLC
Firm License No. P-0370
Matthew T. Ryan, PE
Attachments:
1. Boring Location Plan (1)
2. Boring Log Symbols and Nomenclature Legend (1)
3. Boring Logs (23)
TAI JOB NO.: 18-196-1 MARCH, 2019
B-1
B-8
B-9
B-7
B-3
B-4
B-5
B-6
B-2
B-10
B-11
B-12
B-13
B-14 B-15
B-16 B-17
B-18
B-19
B-20
B-21
B-22
BORING LOCATION PLAN
HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
B-23
Symbols and Nomenclature Penetration Resistance Results - Sands
Undisturbed Sample (UD)
●25 Standard penetration resistance (ASTM D-1586) , with SPT N-Value
50/0.2 Number of blows (50) to drive the spoon a measured distance (0.2 feet)
AX,BX,NX Core barrel sizes for rock cores
65% Percentage of rock core recovered
RQD Rock quality designation - % of core 4 or more inches long
▼ Water table at least 24 hours after drilling
∇ Water table one hour or less after drilling
∆ Loss of drilling water
A Atterberg Limits test performed
C Consolidation test performed
GS Grain size test performed
T Triaxial shear test performed
P Proctor compaction test performed
M=18 Natural moisture content (percent)
Number of blows, N Relative Density
0-4 very loose
5-10 loose
11-20 firm
21-30 very firm
31-50 dense
over 50 very dense or weathered rock
50/0.2' Partially weathered rock
Penetration Resistance Results - Silts and Clays
Number of blows, N Approx. consistency
0-1 very soft
2-4 soft
5-8 firm
9-15 stiff
16-30 very stiff
31-50 hard
over 50 very hard or weathered rock
50/0.2' Partially weathered rock
DRILLING PROCEDURES
Soil sampling and standard penetration testing performed in accordance with ASTM D-1586.
The standard penetration resistance is the number of blows of a 140 pound hammer falling 30
inches to drive a 2 inch O.D., 1.4 inch I.D. split spoon sampler one foot. Core drilling performed
in accordance with ASTM D-2113. Undisturbed sampling (shelby tube) performed in
accordance with ASTM D-1587. Soil classification performed in accordance with ASTM
D2487/D-2488.
ABBREVIATIONS SOIL MOISTURE - CORRELATION OF TERMS
AR - AUGER REFUSAL
BOF – BOTTOM OF FOOTING
BT - BORING TERMINATED
DCP Nc – DYNAMIC CONE PENT. TEST
e - VOID RATIO
FFE – FINISHED FLOOR ELEVATION
HI. – HIGHLY
HP – HIGH PLASTICITY
INV – INVERT
LP – LOW PLASTICITY
MP – MEDIUM PLASTICITY
MED. - MEDIUM
MICA. - MICACEOUS
MOD. – MODERATELY
N – STANDARD PENETRATION TEST
NP. - NON PLASTIC
PFG – PROPOSED FINAL GRADE
TCR - TRICONE REFUSAL
TOF – TOP OF FOOTING
w - MOISTURE CONTENT
V – VERY
γ - UNIT WEIGHT
γd - DRY UNIT WEIGHT
SAMPLE ABBREVIATIONS
S - BULK
SS - SPLIT SPOON
ST - SHELBY TUBE RS - ROCK
RT - RECOMP. TRIAXIAL
CBR - CAILFORNIA BEARING RATIO
FIELD MOISTURE DESCRIPTION
SATURATED - (SAT.)
WET - (W)
MOIST - (M)
DRY - (D)
GUIDE-FIELD MOISTURE DESC.
USUALLY LIQUID, VERY WET,
USUALLY FROM THE BELOW
GROUND WATER TABLE
SEMISOLID: REQUIRES DRYING TO
ATTAIN OPTIMUM MOISTURE
SOLID: AT OR NEAR OPTIMUM
MOISTURE
REQUIRES ADDITIONAL WATER TO
ATTAIN OPTIMUM MOISTURE
EQUIPMENT USED ON SUBJECT PROJECT
DRILL UNITS
□ CMESS
□ CMESS ATV
□ __________
□ __________
CORE SIZE
□-B_________
□-N_________
□-H_________
ADVANCING TOOLS:
□ CLAY BITS
□ 6"CONT. FLIGHT AUGER
□ 8" HOLLOW AUGER
□ CASING □ W/ADVANCER
□ TRICONE___STEEL TEETH
□ TRICONE___TUNG.CARB.
□ CORE BIT
□ ______________________
PERCENTAGE OF MATERIAL
ORGANIC MATERIAL GRANULAR SOILS SILT-CLAY SOILS
TRACE OF ORGANIC MATTER 2-3% 3-5%
LITTLE ORGANIC MATTER 3-5% 5-12%
MODERATELY ORGANIC 5-10% 12-20%
HIGHLY ORGANIC >10% >20%
OTHER MATERIAL
TRACE 1-10%
LITTLE 10-20%
SOME 20-35 %
HIGHLY 35% AND ABOVE
PLASTICITY HAMMER TYPE:
PLASTICITY INDEX (PI)
NONPLASTIC 0-5
LOW PLASTICITY 6-15
MEDIUM PLASTICITY 16-25
HIGH PLASTICITY 26 OR MORE
DRY STRENGTH
VERY LOW
SLIGHT
MEDIUM
HIGH
□ AUTOMATIC □ CAT HEAD
HAND TOOLS:
□ POST HOLE DIGGER □ ______________________
□ HAND AUGER □ ______________________
□ SOUNDING ROD □ ______________________
□ VANE SHEAR TEST
Tai and Associates, PLLC
P.O. Box 90067 Raleigh, NC 27675 (919) 782-9525 www.taiandassociates.com
0.2
5.5
17.0
22.0
35.0
TOPSOIL (2'')
Red, brown, moist, stiff, silty CLAY, with roots
Red, brown, tan, orange, gray, moist, firm to stiff, clayey
SILT
POSSIBLE BOULDERS - Tan, brown, dry, sandy SILT
Tan, brown, orange, gray, dry to moist, very stiff to hard,
clayey, sandy SILT
Boring Terminated at 35.0 Feet
9
13
12
10
7
0.5
35
41
30
490
485
480
475
470
465
460
455
450
445
TAI JOB NO. 18-196-1
B-1
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
50
FFE 472.0
BOF 469.0
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.2
5.5
17.0
22.0
32.0
37.0
42.0
TOPSOIL (2'')
Red, brown, moist, firm to stiff, silty CLAY, with roots
Red, brown, tan, orange, black, moist, stiff, clayey SILT
POSSIBLE BOULDERS - Tan, brown, gray, dry, sandy
SILT
Tan, brown, orange, gray, moist, very stiff to hard, clayey
SILT
WEATHERED ROCK - Tan, brown, orange, gray,
gravelly, clayey SILT
PARTIALLY WEATHERED ROCK - Tan, gray, SILT
Boring Terminated at 42.0 Feet
Auger Refusal at 42.0 Feet
5
13
13
9
13
57
29
33
0.5
0.1
485
480
475
470
465
460
455
450
445
440
TAI JOB NO. 18-196-1
B-2
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
25.4
CAVED
50
50
FFE 472.0
BOF 469.0
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.2
8.0
17.0
20.0
TOPSOIL (2'')
Red, brown, moist, firm to stiff, silty CLAY, with roots
Tan, orange, brown, moist, stiff, clayey SILT, with roots
POSSIBLE BOULDERS - Tan, brown, gray, moist, sandy
SILT
Boring Terminated at 20.0 Feet
9
10
8
9
13
73
475
470
465
460
455
450
445
440
435
430
TAI JOB NO. 18-196-1
B-3
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
FFE 472.0
BOF 469.0
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.1
8.0
15.0
TOPSOIL (1'')
Red, brown, orange, moist, firm to stiff, silty CLAY
Tan, brown, gray, moist, firm, clayey SILT
Boring Terminated at 15.0 Feet
7
12
8
8
6
469
464
459
454
449
444
439
434
429
424
TAI JOB NO. 18-196-1
B-4
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
BOF 469.0 DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.2
17.0
20.0
TOPSOIL (2'')
Red, brown, moist, firm to very stiff, silty CLAY / clayey
SILT
Red, brown, moist, very stiff, clayey SILT
Boring Terminated at 20.0 Feet
7
17
20
21
26
21
489
484
479
474
469
464
459
454
449
444
TAI JOB NO. 18-196-1
B-5
FEBRUARY 13, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
FFE 484.0
BOF 481.0
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.2
5.5
22.0
25.0
TOPSOIL (2'')
Red, brown, moist, firm to stiff, silty CLAY, with roots
Red, brown, orange, black, gray, moist, stiff, clayey SILT,
gravelly from 12.0' - 17.0'
Gray, orange, brown, dry, very stiff, SILT
Boring Terminated at 25.0 Feet
6
10
14
10
12
12
26
482
477
472
467
462
457
452
447
442
437
TAI JOB NO. 18-196-1
B-6
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
FFE 472.0
BOF 469.0
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.1
3.0
12.0
15.0
TOPSOIL (1'')
Red, orange, brown, moist, firm, silty CLAY
Tan, brown, moist, firm, slightly clayey SILT
Gray, brown, black, moist, stiff, silty CLAY
Boring Terminated at 15.0 Feet
8
8
9
7
9
468
463
458
453
448
443
438
433
428
423
TAI JOB NO. 18-196-1
B-7
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
5.5
8.0
12.0
15.0
Red, brown, orange, black, moist, stiff, silty CLAY
Brown, orange, black, moist, firm, SILT
Gray speckled white, stained orange, dry to moist, stiff,
fine sandy SILT
WEATHERED ROCK - Gray speckled white, stained
orange, sandy SILT
Boring Terminated at 15.0 Feet
13
9
7
14
0.4
465
460
455
450
445
440
435
430
425
420
TAI JOB NO. 18-196-1
B-8
FEBRUARY 12, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED 50
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.1
17.0
20.0
TOPSOIL (1'')
Red, brown, moist, firm to very stiff, silty CLAY / clayey
SILT
Red, brown, moist, very stiff, clayey SILT
Boring Terminated at 20.0 Feet
7
11
14
19
26
22
485
480
475
470
465
460
455
450
445
440
TAI JOB NO. 18-196-1
B-9
FEBRUARY 13, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
FFE 484.0
BOF 481.0
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.1
12.0
15.0
TOPSOIL (1'')
Red, brown, orange, moist, firm to stiff, silty CLAY
Tan, gray, moist, firm, clayey SILT
Boring Terminated at 15.0 Feet
8
13
13
10
7
470
465
460
455
450
445
440
435
430
425
TAI JOB NO. 18-196-1
B-10
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
BOF 469.0
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
12.0
15.0
Red, brown, orange, black, moist, firm to stiff, clayey
SILT
Gray speckled white, stained orange, moist, very hard,
sandy SILT
Boring Terminated at 15.0 Feet
8
9
7
12
55
465
460
455
450
445
440
435
430
425
420
TAI JOB NO. 18-196-1
B-11
FEBRUARY 12, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.2
8.0
10.0
TOPSOIL (2'')
Red, brown, moist, stiff to very stiff, silty CLAY
Gray, tan, orange, moist to wet, firm, gravelly, slightly
clayey SILT
Boring Terminated at 10.0 Feet
9
14
16
8
468
463
458
453
448
443
438
433
428
423
TAI JOB NO. 18-196-1
B-12
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.1
10.0
TOPSOIL (1'')
Red, brown, orange, tan, moist, firm to stiff, silty CLAY
Boring Terminated at 10.0 Feet
8
12
9
11
468
463
458
453
448
443
438
433
428
423
TAI JOB NO. 18-196-1
B-13
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.2
3.0
17.0
25.0
TOPSOIL (2'')
Red, brown, moist, firm, silty CLAY, with roots
Red, brown, tan, orange, moist, firm to stiff, slightly
clayey SILT
Gray speckled white, stained orange, moist, stiff to very
stiff, slightly clayey, sandy SILT, with trace gravel
Boring Terminated at 25.0 Feet
5
12
15
5
8
14
18
483
478
473
468
463
458
453
448
443
438
TAI JOB NO. 18-196-1
B-14
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.5
3.0
5.5
8.0
10.0
TOPSOIL (6'')
POSSIBLE FILL - Red, brown, moist, firm, clayey SILT,
with roots and gravel
POSSIBLE FILL - Brown, moist to wet, soft, clayey,
sandy SILT
Gray, brown, moist, firm, CLAY, with trace gravel
Blue, gray, moist, firm, SILT
Boring Terminated at 10.0 Feet
6
2
7
8
461
456
451
446
441
436
431
426
421
416
TAI JOB NO. 18-196-1
B-15
FEBRUARY 13, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
8.0
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.2
8.0
12.0
17.0
25.0
TOPSOIL - (2'')
Red, brown, moist, firm to stiff, silty CLAY
Tan, gray, orange, moist, stiff, clayey SILT
Tan, gray, orange, brown, dry, hard, clayey, sandy SILT
WEATHERED ROCK - Tan, gray, orange, brown, fine
sandy SILT
Boring Terminated at 25.0 Feet
8
12
12
13
36
0.5
0.4
480
475
470
465
460
455
450
445
440
435
TAI JOB NO. 18-196-1
B-16
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
50
50
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
3.0
5.5
10.0
POSSIBLE FILL - Red, brown, moist, firm, clayey SILT,
with gravel and roots
POSSIBLE FILL - Brown, moist, soft, clayey SILT
Tan, gray, orange, brown, moist, firm to stiff, slightly
clayey SILT
Boring Terminated at 10.0 Feet
7
3
6
12
461
456
451
446
441
436
431
426
421
416
TAI JOB NO. 18-196-1
B-17
FEBRUARY 13, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
3.0
10.0
Red, brown, orange, moist, firm, silty CLAY
Orange, brown, black, tan, moist, stiff to very stiff,
slightly clayey, fine sandy SILT
Boring Terminated at 10.0 Feet
8
12
14
18
461
456
451
446
441
436
431
426
421
416
TAI JOB NO. 18-196-1
B-18
FEBRUARY 12, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
3.0
10.0
Red, brown, moist, stiff, silty CLAY
Orange, brown, black, dry to moist, stiff to very stiff,
clayey, fine sandy SILT
Boring Terminated at 10.0 Feet
14
13
15
22
467
462
457
452
447
442
437
432
427
422
TAI JOB NO. 18-196-1
B-19
FEBRUARY 12, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.1
10.0
TOPSOIL (1'')
Red, brown, orange, tan, black, moist, firm to very stiff,
SILT, with varying amounts of clay
Boring Terminated at 10.0 Feet
12
8
10
17
465
460
455
450
445
440
435
430
425
420
TAI JOB NO. 18-196-1
B-20
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
12.0
20.0
Red, brown, moist, firm to very stiff, silty CLAY
Orange, brown, moist, stiff to very stiff, clayey SILT
Boring Terminated at 20.0 Feet
6
10
15
20
16
15
480
475
470
465
460
455
450
445
440
435
TAI JOB NO. 18-196-1
B-21
FEBRUARY 13, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
0.1
8.0
12.0
17.0
25.0
TOPSOIL (1'')
Red, brown, moist, firm to stiff, silty CLAY
Tan, gray, dry, very stiff, SILT
Tan, gray, black, moist, firm, clayey SILT
WEATHERED ROCK - Brown, gray, sandy SILT
Boring Terminated at 25.0 Feet
7
9
9
28
7
0.3
0.3
480
475
470
465
460
455
450
445
440
435
TAI JOB NO. 18-196-1
B-22
FEBRUARY 14, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
22.0
CAVED
50
50
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)
3.0
10.0
Red, brown, moist, stiff, silty CLAY
Orange, brown, tan, moist, firm to stiff, SILT, with
varying amounts of clay
Boring Terminated at 10.0 Feet
9
12
5
7
465
460
455
450
445
440
435
430
425
420
TAI JOB NO. 18-196-1
B-23
FEBRUARY 12, 2019
THE HAWBRIDGE SCHOOL
SAXAPAHAW, NORTH CAROLINA
THE HAWBRIDGE SCHOOL
PAGE 1 OF 1
DRY
CAVED
DEPTH DESCRIPTION GW ELEV 10 50 90
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525
PROJECT:
LOCATION:
CLIENT:
BORING NO.
DATE:
N-VALUE (ASTM D-1586)