SW5190702_NC Veterans Home Geotechnical Report 071618_7/12/2019

Tai and Associates, PLLC
P.O. Box 90067 Raleigh, NC 27675 [phone] www.taiandassociates.com
PRELIMINARY SUBSURFACE EXPLORATION REPORT
Conducted On:
North Carolina Veterans Home
Raleigh, North Carolina
Tai Job No. 18-137-1
For:
CALYX Engineers
6750 Tryon Road
Cary, North Carolina
July 16, 2018
Prepared By:
Tai and Associates, PLLC
NC Firm License No. P-0370
DocuSigned by:
Matthew TYYan, PE
9AF83C687C44407... `O0� °
- SEAL
027467
219T �NGIN ...

Tai and Associates, PLLC
P.O. Box 90067 Raleigh, NC 27675 [phone] www.taiandassociates.com
July 16, 2018
Mr. Michael D. Allen, PE
CALYX Engineers
6750 Tryon Road
Cary, North Carolina 27518
Re: Preliminary Subsurface Exploration Report
North Carolina Veterans Home
Raleigh, North Carolina
Tai Job No.: 18-137-1
Dear Mr. Allen:
As authorized, we have completed a preliminary subsurface exploration program for the referenced
project. This program consisted of the drilling of six (6) soil borings, classification of soil samples recovered,
site visit, engineering services including analyses of subsurface conditions, and the preparation of this written
report.
FIELD EXPLORATION
The field exploration program consisted of the drilling of six (6) soil borings (B-I through B-6)
advanced to a maximum depth of 40.0 feet below the ground surface. The drilling was performed by a CME
550 drill rig using 2-'/4" inside diameter hollow stem augers to advance the boreholes. Standard Penetration
Tests (ASTM D-1586) were performed at every 2.5-foot interval to 10.0 feet 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 elevations were interpolated from the Wake County GIS website 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.
SURFACE CONDITIONS
The site is currently wooded, undeveloped land, and has not been developed since at least 1938
according to historical aerial photographs, with the exception of agricultural usage. The topography varies
in elevation from 410.0 to 460.0.

North Carolina Veterans Home
Tai Job No. 18-137-1
July 16, 2018
Page 2
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:
Topsoil: Topsoil was encountered in all of the soil borings and was 5.0 to 6.0 inches thick.
2. Silty Residual Soil: Below the topsoil is the 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 clayey, sandy silt and fine
sandy silt.
a. Clayey, sandy silt is red/brown in color, contains variable amounts of mica, and is found
up to a depth of 3.0 feet below ground surface. SPT N-Values for this soil were 8 to 11
(firm to stiff). This soil is of a moderate engineering quality.
b. Fine sandy silt is found below 3.0 feet depth and it is red, brown, purple, tan and gray in
color. This soil is firm to very stiff (SPT N-Values of 8 to 30) and micaceous. Trace
gravel was encountered at variable depths in borings B-2, B-4 and B-6. This soil is of a
moderate engineering quality.
Groundwater: Groundwater was not encountered in any of the soil borings. Some trapped
or perched groundwater probably exists between the borings.
PROPOSED PROJECT
Based on correspondence with the design team, we understand that at this preliminary stage of
design, the proposed project consists of the design and construction of a single -story, 120-bed, skilled nursing
care facility and the related infrastructure. The 110,000 to 140,000 sf building location has not been selected,
and the finish floor elevation is unknown. We presume the building will consist of wood -framed or cold -
formed steel framed construction over slab -on -grade. Foundation loading is unknown, but for preliminary
planning purposes, we anticipate maximum column and wall loads to be on the order of 125 kips and 4 kips
per linear foot, respectively. Cuts and fills up to 10.0 feet is anticipated.
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 (net contact 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

North Carolina Veterans Home
Tai Job No. 18-137-1
July 16, 2018
Page 3
firm or stiff residual soils, new controlled fill, or an improved subgrade. All footing subgrades must be
inspected and approved for the required bearing capacity utilizing field engineering judgment.
The estimated maximum total and differential post -construction settlement is 1.0 and 0.5 inches,
respectively. All foundation systems should be designed at elevations such that no utility lines, utility line
excavation, or retaining wall, and any other footings are located within a 1:1 zone of influence of the edge of
the subject footing. There should be at least 12.0 inches of cover on all exterior footings to prevent frost
penetration. See attachment for settlement estimates.
Building
Net Allowable Bearing
Capacity
Soil Bearing Condition
1-Story
3,000 psf
Up to 125-kip column loads
break.
Expansion joints should be provided on the exterior walls at regular intervals and at every building
Excavation
All normal size earth -moving equipment can easily move the materials encountered in the borings.
It appears that footings and utilities within the building pad should be excavatable with a rubber -tire backhoe.
Rock excavation is not anticipated within 20.0 feet of existing ground surface at the site.
The project specification should include the definition of rock. Rock should be defined as materials
that cannot be excavated with a CAT 325 track -mounted hydraulic excavator, equipped with rock teeth.
Boulders exceeding 1.0 cy in mass excavations and 0.75 cy in trench excavations should also be classified as
rock. We do not anticipate rock excavation for the footings; however, a definition and unit prices for mass
rock and trench excavation should be included in the specification and contract.
Cut and Fill
All fill and any backfill should be placed and compacted to a minimum of 98% of the Standard
Proctor Density (ASTM D-698). The moisture content of the fill during placement must be kept within ±2%
of the optimum value. Most of the natural, non -plastic residual soils in the cut areas should provide suitable
regular backfill fill material except for any plastic clay pockets and all boulders larger than 6.0 inches in any
dimension. In -place density tests should be performed at a rate of one test per lift per 2,500 sf, per lift, per
day (ASTM D-1556).

North Carolina Veterans Home
Tai Job No. 18-137-1
July 16, 2018
Page 4
Utilities
All utility pipes should be supported on top of at least 6.0 inches of granular free draining 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.
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.
Slabs
The floor slab can be designed as slab -on -grade over a well -prepared subgrade. The slabs should be
constructed over four (4) inches of ABC Stone. 457 stone can be utilized as an alternative. 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.
Retaining.
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 457 washed stone) be used as backfill for the entire,
below -grade face of all site concrete retaining walls. A filter fabric (Mirafi 140N or equal) should be used
to separate the 457 stone and the regular soil backfill to avoid losing fines into the voids. The retaining walls
without top supports, if any, should be designed against an active equivalent fluid pressure. Perimeter
foundation drains should be installed behind the walls. All other soil backfill must be placed in thin layers
and compacted to 98% of the maximum Standard Proctor Density (ASTM D-698).
The following soil parameters should be used in analyzing the stability of the wall and footing:
Friction angle
28 deg.
O Unit weight
105 pcf
ka Active earth pressure coefficient
0.361
ko At -rest earth pressure coefficient
0.531
k Passive earth pressure coefficient
2.770
ka (Equivalent active earthpressure)
38 pcf
ko (Equivalent at -rest earthpressure)
56 pcf
k (Equivalent passive earthpressure)
291 pcf
Sliding Friction of Coefficient at Base
0.45

North Carolina Veterans Home
Tai Job No. 18-137-1
July 16, 2018
Page 5
Pavement
The pavement system should be supported on a carefully prepared site subgrade as outlined in the
next section. 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.OB As halt
5-9.513 Asphalt
Equiv. 18,000 lb. Axle Trips / Da
Light Duty
8
2.0
cars only
Intermediate Duty
8
3.0
3.7
Heavy Duty
8
2.5
1.5
9.9
Groundwater
Groundwater was not encountered in the soil borings. However, perched or trapped groundwater
within the upper soil layers is common in the geology of the project site. The design of the building must
take into account the potential for minor trapped groundwater below the slab. Provisions should be made to
divert all surface water away from the building, and a foundation drain tied to the storm drain system should
be installed around the entire perimeter of the building and at all below -grade retaining walls
CONSTRUCTION CONSIDERATIONS
Engineering Behavior of Soils
The on -site silty 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 fills, where required.
However, upon excavation, even some of these soils can become unsuitable if they become wet.
Groundwater
While not encountered in the soil borings, groundwater is commonly encountered in gravel veins in
this geologic region and between clayey soil layers, and it is possible that perched or trapped groundwater is
present on site. Upon reaching grade during mass excavation, portions of the subgrade will likely consist of
low -permeability soils that will not drain freely. As a result, surface water will not infiltrate the soil and all
surface water in cut areas will require pumping if the area cannot be graded to shed surface water.
Additionally, as mentioned, we anticipate some trapped or perched groundwater within the upper soil layers
to enter any cut slopes continuously or intermittently at a slow rate during construction. We expect that
surface and groundwater control measures, such as sumps, pumps, French drains, or diversion ditches will
be required.

North Carolina Veterans Home
Tai Job No. 18-137-1
July 16, 2018
Page 6
Grading
The project site should be cleared of all the existing surface features such as topsoil, tree stumps,
debris, etc. Most of the natural, non -plastic residual soil excavated can be reused as structural fill. 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 in -place prior to any grading and earthwork activity. We anticipate that after
each rainfall event during construction, wet conditions will result in rain impact days and the generation of
wet, unsuitable soil.
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). We suggest budgeting
for undercut in the about of approximately 10% of the total fill required to grade the site.
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-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
The subgrade for the concrete and asphalt pavement systems will require inspection of the subgrade
and ABC stone subbase. Some additional improvement may be required including undercutting and/or
placement of Mirafi 500X geofabric due to existing fill or areas damaged by surface water and construction
traffic.
ADDITIONAL SERVICES
As the design progresses, and when selection of building location, building elevation, parking lot
layout, and utility locations has been made, a final geotechnical report consisting of additional soil test
borings can be prepared.

North Carolina Veterans Home
Tai Job No. 18-137-1
July 16, 2018
Page 7
FIELD SERVICES
The final geotechnical report must be performed and all earthwork and foundation construction
activities must be observed by a field representative of this firm to ensure that the actual subsurface conditions
encountered during construction are consistent with the design intent and 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 by this
firm. We cannot be held responsible for the conditions stated above and the post -construction performance
of the foundation and the pavement systems unless we are authorized to perform the field services required.
CLOSURE
It is our continued pleasure to work with you and your design team on the preliminary phase of this
project. Please call us if you have any questions or if we can offer any additional information or services
during the design phase of this project.
Very Truly Yours,
Tai and Associates, PLLC
Firm License No. P-0370
DocuSigned by:
9AF83C687C44407...
Matthew T. Ryan, PE
Attachments: _ \ Zo ass o0`�`9
1. Boring Location Plan (1) - °°Q� SEAL-
2. Boring Log Symbols and Nomenclature Legend (1)
3. Boring Logs (6) 027467
CC: Michael Allen, PE <mallen(a calyxengineers.com>; / �9TryEW I° �yP ,
�'IIriiii11++++

APPROXIMATE
SITE BOUNDARY
0

Tai and Associates, PLLC _
P.O. Box 90067 Raleigh, NC 27675 [phone] www.taiandassociates.com
Symbols and Nomenclature
Penetration Resistance Results - Sands
Undisturbed Sample (UD)
Number of blows, N
Relative Density
925 Standard penetration resistance (ASTM D-1586) , with SPT N-Value
0-4
very loose
50/0.2 Number of blows (50) to drive the spoon a measured distance (0.2 feet)
5-10
loose
AX,BX,NX Core barrel sizes for rock cores
11-20
firm
65% Percentage of rock core recovered
21-30
very firm
RQD Rock quality designation - % of core 4 or more inches long
31-50
dense
_T_ Water table at least 24 hours after drilling
over 50
very dense or weathered rock
V Water table one hour or less after drilling
50/0.2'
Partially weathered rock
o Loss of drilling water
A Atterberg Limits test performed
Penetration Resistance Results - Silts and Clays
C Consolidation test performed
Number of blows, N
Approx. consistency
GS Grain size test performed
T Triaxial shear test performed
0-1
very soft
P Proctor compaction test performed
2-4
soft
M=18 Natural moisture content (percent)
5-8
firm
9-15
stiff
DRILLING PROCEDURES
16-30
very stiff
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
31-50
hard
inches to drive a 2 inch O.D., 1.4 inch I.D. split spoon sampler one foot. Core drilling performed
over 50
very hard or weathered rock
in accordance with ASTM D-2113. Undisturbed sampling (shelby tube) performed in
50/0.2'
Partially weathered rock
accordance with ASTM D-1587. Soil classification performed in accordance with ASTM
D2487/D-2488.
ABBREVIATIONS
SOIL MOISTURE - CORRELATION OF TERMS
AR -AUGER REFUSAL NP. - NON PLASTIC
FIELD MOISTURE DESCRIPTION
GUIDE -FIELD MOISTURE DESC.
BOF—BOTTOM OF FOOTING PFG — PROPOSED FINAL GRADE
(SAT.)
SATURATED - SAT.
USUALLY LIQUID, VERY WET,
TCR - TRICONE REFUSAL
USUALLY FROM THE BELOW
BT - BORING TERMINATED
GROUND WATER TABLE
TOF —TOP OF FOOTING
DCP Nc — DYNAMIC CONE PENT. TEST w -MOISTURE CONTENT
WET - (W)
SEMISOLID: REQUIRES DRYING TO
e - VOID RATIO V —VERY
ATTAIN OPTIMUM MOISTURE
FFE — FINISHED FLOOR ELEVATION y - UNIT WEIGHT
MOIST - (M)
SOLID: AT OR NEAR OPTIMUM
HI. — HIGHLY yd - DRY UNIT WEIGHT
MOISTURE
HP —HIGH PLASTICITY
DRY-(D)
REQUIRES ADDITIONAL WATER TO
INV — INVERT SAMPLE ABBREVIATIONS
ATTAIN OPTIMUM MOISTURE
LP — LOW PLASTICITY S - BULK
EQUIPMENT USED ON SUBJECT PROJECT
MP —MEDIUM PLASTICITY SS- SPLIT SPOON
ST - SHELBY TUBE RS - ROCK
DRILL UNITS
ADVANCING TOOLS:
MED. - MEDIUM
RT - RECOMP. TRIAXIAL
MICA. -MICACEOUS CBR- CAILFORNIABEARINGRATIO
❑ CMESS
ElCLAY BITS
MOD. — MODERATELY
❑ CMESSATV
❑ 6"CONT. FLIGHTAUGER
N —STANDARD PENETRATION TEST
❑ 8" HOLLOW AUGER
PERCENTAGE OF MATERIAL
❑
El
❑ CASING o W/ADVANCER
ORGANIC MATERIAL GRANULAR SOILS SILT -CLAY SOILS OTHER MATERIAL
TRACE OF ORGANIC MATTER 2-3% 3-5% TRACE 1-10%
CORE SIZE
❑ TRICONE_STEEL TEETH
LITTLE ORGANIC MATTER 3-5% 5-12% LITTLE 10-20%
❑-B
❑ TRICONE_TUNG.CARB.
MODERATELY ORGANIC 5-10% 12-20% SOME 20-35
HIGHLYORGANIC >10% >20% HIGHLY 35%AND ABOVE
❑-N
❑ CORE BIT
❑-H
❑
PLASTICITY
HAMMER TYPE:
PLASTICITY INDEX (PI) DRY STRENGTH
❑ AUTOMATIC ❑ CAT
HEAD
NONPLASTIC 0-5 VERY LOW
HAND TOOLS:
LOW PLASTICITY 6-15 SLIGHT
❑ POST HOLE DIGGER
❑
MEDIUM PLASTICITY 16-25 MEDIUM
HIGH
HIGH PLASTICITY 26OR MORE
❑ HAND AUGER
❑
❑ SOUNDING ROD
❑
❑ VANE SHEAR TEST

BORING LOG
PROJECT: NORTH CAROLINA VETERAN'S HOME
LOCATION: RALEIGH, NORTH CAROLINA
CLIENT: CALYX ENGINEERS
TlF PTA TlF',C P TPTTC)I\T
BORING NO. B-1
PAGE 1 OF 1
DATE: JULY 5, 2018
N-VALUE (ASTM D-1586)
GW ELEV 10 50 90
1.0
TOPSOIL (6")
432
9
3.0
Red, brown, dry, firm, fine sandy SILT, with mica
427
9
DRY
10
422
Red, brown, purple, tan, gray, dry, stiff, micaceous, fine
sandy SILT
I
12
417
CAVED
I
9
20.0
412
Boring Terminated at 20.0 Feet
407
402
397
392
TAI JOB NO. 18-137-1
'1'Al and ASSOCIA'l'ES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525

BORING LOG
PROJECT: NORTH CAROLINA VETERAN'S HOME
LOCATION: RALEIGH, NORTH CAROLINA
CLIENT: CALYX ENGINEERS
TlF PTA TlF',C P TPTTC)I\T
BORING NO. B-2
PAGE I OF I
DATE: JULY 5, 2018
N-VALUE (ASTM D-1586)
GW ELEV 10 50 90
1.0
TOPSOIL (6")
452
447
�11
12
3.0
Red, brown, dry, stiff, fine sandy SILT, with mica
10
DRY
442
12
Red, brown, purple, tan, gray, dry, stiff to very stiff,
micaceous, fine sandy SILT, with trace quartz gravel from
8.0 to 12.0 feet
437
�20
CAVED
/
20.0
432
111
Boring Terminated at 20.0 Feet
427
422
417
412
TAI JOB NO. 18-137-1
'1'Al and ASSOCIA'l'ES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525

BORING LOG
PROJECT: NORTH CAROLINA VETERAN'S HOME
LOCATION: RALEIGH, NORTH CAROLINA
CLIENT: CALYX ENGINEERS
TlF PTA TlF',C P TPTTC)I\T
BORING NO. B-3
PAGE I OF I
DATE: JULY 5, 2018
N-VALUE (ASTM D-1586)
GW ELEV 10 50 90
1.0
TOPSOIL (5")
436
Red, brown, dry, firm, slightly clayey, fine sandy SILT
3.0
with mica
431
13
DRY
�14
426
6
Red, brown, purple, tan, gray, dry, stiff to very stiff,
micaceous, fine sandy SILT
421
2
I
CAVED
I
20.0
416
ll
Boring Terminated at 20.0 Feet
411
406
401
396
TAI JOB NO. 18-137-1
'1'Al and ASSOCIA'l'ES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525

BORING LOG
PROJECT: NORTH CAROLINA VETERAN'S HOME
LOCATION: RALEIGH, NORTH CAROLINA
CLIENT: CALYX ENGINEERS
DEPTH DESCRIPTION
BORING NO. B-4
PAGE 1 OF 1
DATE: JULY 5, 2018
N-VALUE (ASTM D-1586)
GW ELEV 10 50 90
1.0
TOPSOIL (6")
454
10
Red, brown, dry, stiff, clayey, fine sandy SILT, with mica
3.0
12
449
10
DRY
444
I
I
9
439
I
10
434
Red, brown, purple, tan, gray, dry, firm to very stiff,
micaceous, fine sandy SILT, with trace gravel from 3.0 to
5.5 feet and 32.0 to 37.0 feet
12
429
I
I
1
424
22
419
CAVED
1
1
30
40.0
414
Boring Terminated at 40.0 Feet
TAI JOB NO. 18-137-1
TAI and ASSOCIATES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525

BORING LOG
PROJECT: NORTH CAROLINA VETERAN'S HOME
LOCATION: RALEIGH, NORTH CAROLINA
CLIENT: CALYX ENGINEERS
TlF PTA TlF',C P TPTTC)I\T
BORING NO. B-5
PAGE 1 OF 1
DATE: JULY 5, 2018
N-VALUE (ASTM D-1586)
GW ELEV 10 50 90
1.0
TOPSOIL (5")
460
11
Red, brown, dry, stiff, slightly clayey, fine sandy SILT,
3.0
with mica
455
1
DRY
450
9
Red, brown, purple, tan, gray, dry, firm to very stiff,
micaceous, fine sandy SILT
445
9
CAVED
I
I
20.0
440
•
Boring Terminated at 20.0 Feet
435
430
425
420
TAI JOB NO. 18-137-1
'1'Al and ASSOCIA'l'ES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525

BORING LOG
PROJECT: NORTH CAROLINA VETERAN'S HOME
LOCATION: RALEIGH, NORTH CAROLINA
CLIENT: CALYX ENGINEERS
TlF PTA TlF',C P TPTTC)I\T
BORING NO. B-6
PAGE I OF I
DATE: JULY 5, 2018
N-VALUE (ASTM D-1586)
GW ELEV 10 50 90
1.0
TOPSOIL (6")
450
9
Red, brown, dry, stiff, slightly clayey, fine sandy SILT,
3.0
with mica
19
445
7
DRY
21
440
Red, brown, purple, tan, gray, dry, very stiff, micaceous,
fine sandy SILT, with trace gravel from 3.0 to 5.5 feet
I
1
435
CAVED
I
I
19
20.0
430
Boring Terminated at 20.0 Feet
425
420
415
410
TAI JOB NO. 18-137-1
'1'Al and ASSOCIA'l'ES, PLLC
PO BOX 90067 RALEIGH, NC 27675 919-782-9525