24039_Jones Electric_Test Pit Exploration_20200526

SUMMARY OF ADDITIONAL GEOTECHNICAL SERVICES 7TH STREET APARTMENTS - REVISION NO. 1 705 EAST 7TH STREET CHARLOTTE, NORTH CAROLINA SUMMIT PROJECT NO. 4164.11 R.1
Prepared For: Mr. Bobby Thapar
Laurel Street Residential 511 East Boulevard Charlotte, North Carolina 28203 Email: [e-mail]
Prepared By: SUMMIT Engineering, Laboratory & Testing, P.C. (SUMMIT) 3575 Centre Circle Drive
Fort Mill, South Carolina 29715
May 26, 2020
May 26, 2020
Mr. Bobby Thapar
Laurel Street Residential 511 East Boulevard Charlotte, North Carolina 28203 Email: [e-mail]
Subject: Summary of Additional Geotechnical Services 7th Street Apartments – Revision No. 1 705 East 7th Street Charlotte, North Carolina SUMMIT Project No. 4164.11 R.1
Dear Mr. Thapar:
As requested, SUMMIT Engineering, Laboratory and Testing, P.C. (SUMMIT) has provided
additional geotechnical services performed at the site located at 705 East 7th Street in Charlotte,
North Carolina. These geotechnical services were performed in general accordance with our conversations, email correspondences and our Proposal No. P2019-837-G-TP dated February 11, 2020. This report contains a brief description of the project information provided to us, general site and subsurface conditions revealed during our test pit excavation and our general
recommendations regarding foundation design and construction.
SUMMIT appreciates the opportunity to be of service to you on this project. If you have any questions concerning the information presented herein or if we can be of further assistance, please feel free to call us at [phone].
Sincerely yours,
SUMMIT ENGINEERING, LABORATORY AND TESTING, P.C. (SUMMIT)
Todd A. Costner, E.I. Kerry C. Cooper, P.E.
Senior Professional Geotechnical Department Manager
5/26/20
Summary of Additional Geotechnical Services SUMMIT Project No. 4164.11 R.1
7th Street Apartments, Charlotte, NC May 26, 2020
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LIST OF APPENDICES 1. Figures – Figure 1: Site Vicinity Map Figure 2: Test Location Plan
2. Summary of Test Pit Observation Sheets
3. Photographic Logs

Summary of Additional Geotechnical Services SUMMIT Project No. 4164.11 R.1
7th Street Apartments, Charlotte, NC May 26, 2020
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SITE AND PROJECT DESCRIPTION
The subject site is located at 705 East 7th Street in Charlotte, North Carolina. The subject property
is approximately 1.21 acres comprised of Mecklenburg County Tax Parcel ID Number 08010402
and a portion of IDs Number 0801408. Based on our site observation and review of historical
aerial photographs previous developed had occurred on the property that consisted of an industrial
mill facility, residential structures, and asphalt paved parking lots and roadways.
SUMMIT was provided a plan a plan sheet titled “Sketch Plan”, prepared by Timmons Group
dated July 9, 2019 that indicated the configurations of the proposed construction planned for this
project and the locations of the test pits. Based on the provided information, we understand the
project is planned to include a 100-unit five-story multi-family complex with associated
pavements, and an underground stormwater retention.
At the time of report preparation, SUMMIT had not been provided structural details of the planned
construction indicating proposed loads and foundation bearing elevations. For this report,
SUMMIT assumed the proposed structures will be supported on a shallow foundation system
consisting of spread, strip, and/or combined footings and that maximum wall loads will be on the
order of 4 to 5 kips per foot and the maximum column loads will be 100 kips. Based on the provided
plans, the projected cut and fill depths will be on the order of 1 to 3 feet from the existing ground
surface.
PURPOSE OF ADDITIONAL GEOTECHNICAL SERVICES
The purpose of this test pit exploration was to obtain additional geotechnical information regarding
the subsurface conditions encountered during our previous geotechnical subsurface exploration
report dated December 10, 2019. This report contains the following items:
• General subsurface conditions observed at each test pit location,
• Summary of Test Pit log(s), Summary of Hand Auger Boring, and an approximate Test Location Plans.
Summary of Additional Geotechnical Services SUMMIT Project No. 4164.11 R.1
7th Street Apartments, Charlotte, NC May 26, 2020
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EXPLORATION PROCEDURES
On May 1, 2020, SUMMIT visited the site to observe the excavation of nine (9) test pits (identified
as TP-1 through TP-5 and TP-7 through TP-10). Please note that Test Pit TP-6 was not performed
because the test location was not accessible due to the existing building, underground utilities and
existing tree. Also, some of the test pit were offset from the requested location due to existing
trees and underground utilities. The test pits were performed at the approximate locations shown
on Figure 2 – “Test Location Plan” provided in Appendix 1. The test pits were located by
professionals from our office using existing test locations, site observations, provided plan,
existing structures, and aerial maps as reference. Since the test locations were not surveyed, the
test locations should be considered approximate.
The test pits were excavated using a Hyundai 140 LC-9 trackhoe. The test pits were excavated to
approximate depths ranging from 5 to 16 feet below the existing ground surface. The soil
excavated from the test pits were visually examined and classified by a qualified geotechnical
professional. The test pits were backfilled with the excavated materials.

SUBSURFACE CONDITIONS
Generalized Subsurface Stratigraphy
General subsurface conditions encountered during our test pit exploration are described herein.
For more detailed soil descriptions and stratifications at a particular soil test pit, the respective
“Summary of Test Pit Observation Sheet” provided in Appendix 2 should be reviewed. The
horizontal stratification lines designating the interface between various strata represent
approximate boundaries. Transitions between different strata in the field may be gradual in both
the horizontal and vertical directions.
Surface Materials/Topsoil
Surface material/topsoil (surface soils) was encountered at the existing ground surface of all test
locations with approximate thickness of 2 inches.
Summary of Additional Geotechnical Services SUMMIT Project No. 4164.11 R.1
7th Street Apartments, Charlotte, NC May 26, 2020
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Existing Fill Soils
Existing fill (disturbed) soils were observed beneath the surface materials in all the test locations.
The existing fill soils were observed to approximate depths ranging from 1 to 10 feet below the
existing ground surface. The existing fill soils generally consisted of elastic silts (MH), sandy silts
(ML) and silty sands (SM).
Please note that the organic and laden stained fill soils were encountered in the Test Pits TP-1, TP-
4, TP-7 and TP-10 at various depths. Debris were encountered in all of the test pits at various
depths. The construction debris generally consisted of concrete debris, mortar debris, metal, and
boulders. Organic stained and/or laden soils and construction debris are considered not suitable
for building and pavement support and are not suitable to be re-used as structural fill material. The
organic stained/laden soils may be utilized as non-structural fill and backfill at landscaped or non-
pavement areas of the project.
The following table summarizes the locations and approximate depths that existing fill soils were
encountered in the test pits performed for this exploration.
Summary Table of Existing Fill Soils Depths
Test Location No. Existing Fill Soil Approx. Depth, (feet)1 Organic Stained Approx. Depth, (feet)1 Construction Debris Approx. Depth, (feet)1
TP-1 11.5 2.5 - 11 0.2 - 2.5 & 7 - 11.5
TP-2 13 --- 7 - 13
TP-3 6 --- 3 - 6
TP-4 10 7 - 10 0.2 - 10
TP-5 7 --- 0.25 - 7
TP-6 Test Pit was not performed
TP-7 6 4 - 6 4 - 6
TP-8 3 --- 3
TP-9 3.5 --- 3.5
TP-10 6.5 4 – 6.5 4 – 6.5
1Depths were measured from the existing ground surface.
Based on historical aerial photographs and our site observations, previous grading activities and/or
development have occurred on the property. As such, the contractor should anticipate the presence
Summary of Additional Geotechnical Services SUMMIT Project No. 4164.11 R.1
7th Street Apartments, Charlotte, NC May 26, 2020
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of fill soils, active or abandoned utility lines, and/or construction debris that were not encountered
in the test pits performed for this exploration. If fill soils are encountered at other locations in the
field during construction, the fill soils should be evaluated by the Geotechnical Engineer-of-
Record, or their authorized representative, with respect to the criteria outlined in this report and
our geotechnical report dated December 10, 2019.
Alluvial Soils
Alluvial (water-deposited) soils were encountered beneath the surface materials and existing fill
soils in Test Pit TP-3 between the approxaimte depths of 6 to 9 feet, Test Pit TP-5 between the
approxaimte depths of 7 to 13 feet, and Test Pit TP-7 between the approxaimte depths of 6 to 8
feet. When sampled, the alluvial soils generally consisted of sandy silts (ML) and silty sands
(SM).
Residual Soils
Residual (undisturbed) soils were encountered below the surface material, existing fill soils, and/or
alluvial soils. The residual soils generally consisted of lean clays (CL), sandy silts (ML) and clayey
sands (SC).
Water Level Measurements
Groundwater was observed in Test Pits TP-1, TP-2, and TP-5 at approxaimte depths of 11, 11, and
12 feet. It should also be noted that groundwater levels tend to fluctuate with seasonal and climatic
variations, as well as with some types of construction operations. Therefore, water may be
encountered during construction at depths not indicated in the borings performed for this
exploration.
CONCLUSION
Based on the results of the current test pits and previous borings results from our geotechnical
subsurface exploration, the proposed construction could be supported on a combination of a
shallow foundation system and deep foundation system. We do not recommend a Post Tension
Slab System as a primary foundation system for supporting the proposed construction.
Summary of Additional Geotechnical Services SUMMIT Project No. 4164.11 R.1
7th Street Apartments, Charlotte, NC May 26, 2020
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Details of a shallow foundation systems and deep system are outlined in Section 4.2 of our
geotechnical report dated December 10, 2019. Using the current and previous field results and
provided building loads by the structural engineer, the estimated settlement using a Post Tension
Slab System would exceed acceptable limits of total and differential settlements due to the
consolidation of the underlying soils under the building loads.
Our recommended next steps would be to consult the structural engineer and/or deep foundations
contractor to evaluate the most effective combination of deep and shallow foundation systems
from an engineering and cost perspective.

QUALIFICATIONS OF REPORT
This exploration has been provided for the sole use of Laurel Street Residential. This exploration
should not be relied upon by other parties without the express written consent of SUMMIT and
Laurel Street Residential.
The results submitted in this report were based, in part, on data obtained from the test pits. If the
above-described project conditions are incorrect or changed after the issuing of this report, or
subsurface conditions encountered during construction are different from those reported,
SUMMIT should be notified and should be re-evaluated based on the changed conditions to make
appropriate revisions. We have prepared this report according to generally accepted geotechnical
engineering practices. No warranty, express or implied, is made as to the professional advice
included in this report.
Summary of Additional Geotechnical Services SUMMIT Project No. 4164.11 R.1 7th Street Apartments, Charlotte, NC May 26, 2020

APPENDIX 1
FIGURES
Summary of Additional Geotechnical Services SUMMIT Project No. 4164.11 R.1 7th Street Apartments, Charlotte, NC May 26, 2020

APPENDIX 2
SUMMARY OF TEST PIT
OBSERVATION SHEETS

SUMMARY OF TEST PIT OBSERVATION SHEET 7TH STREET APARTMENTS 705 EAST 7TH STREET CHARLOTTE, NORTH CAROLINA SUMMIT PROJECT NO. 4164.11
Test Pit Number
Depth (feet)*
Soil Description TP-1
0 – 0.2 0.2 – 2.5 2.5 - 7 7 – 11 11 – 11.5 11.5
Approximately 2” of Topsoil FILL: Moist Dark Yellowish Brown Slightly Clayey Sandy SILT with some Debris (Concrete, Brick, Mortar and Asphalt) FILL: Moist Red and Brownish Yellow Slightly Clayey Sandy SILT with a layer of Organic Stained Soil FILL: Dark Brown (Organic Stained) Silty SAND with some Debris (Concrete, Brick, Mortar and Rocks) FILL: Boulders Test Pit Refused on Rock Groundwater encountered at an approx. depth of 11 feet Test Pit Terminated Depth -11.5 feet TP-2
0 – 0.2 0.2 – 7 7 - 13
Approximately 2” of Topsoil FILL: Moist Dark Brownish Red Slightly Clayey Sandy SILT with some Debris (Concrete, Brick, Rebar, Boulders and Asphalt) FILL: Boulders and Concrete Debris with Brown Slightly Clayey Sandy SILT Test Pit Refused on Rock Groundwater encountered at an approx. depth of 11 feet Test Pit Terminated Depth -13 feet *Referenced from existing ground elevation Note: Test Pits Performed with a Hyundai 140 LC-9 trackhoe
SUMMARY OF TEST PIT OBSERVATION SHEET 7TH STREET APARTMENTS 705 EAST 7TH STREET CHARLOTTE, NORTH CAROLINA SUMMIT PROJECT NO. 4164.11 Test Pit Number
Depth (feet)*
Soil Description
TP-3
0 – 0.2 0.2 – 3 3 - 6 6 – 9 9 - 11
Approximately 2” of Topsoil FILL: Moist Brownish Red Sandy Elastic SILT FILL: Moist Red, Yellow and Brownish Gray Slightly Clayey Sandy SILT with some Debris (Concrete, Brick, Mortar and Rocks) ALLUVIUM: Moist Gray Slightly Clayey Sandy SILT RESIDUUM: Moist Gray and Light Brown Clayey SAND Test Pit Refused on Rock Groundwater Not Observed in Test Pit at Time of Completion Test Pit Terminated Depth -11 feet
TP-4
0 – 0.2 0.2 – 7 7 – 10 10 – 12.5
Approximately 2” of Topsoil FILL: Moist Brownish Red Sandy Elastic SILT with some Debris (Asphalt, Concrete and Rocks) DEBRIS: Debris (Wood, Concrete) with Brownish Gray (Organic Stained) Slightly Clayey Sandy SILT RESIDUUM: Moist Light Gray and Yellow Clayey SAND Test Pit Refused on Rock Groundwater Not Observed in Test Pit at Time of Completion Test Pit Terminated Depth -12.5 feet *Referenced from existing ground elevation Note: Test Pits Performed with a 140 LC -9
SUMMARY OF TEST PIT OBSERVATION SHEET 7TH STREET APARTMENTS 705 EAST 7TH STREET CHARLOTTE, NORTH CAROLINA SUMMIT PROJECT NO. 4164.11 Test Pit Number
Depth (feet)*
Soil Description
TP-5
0 – 0.2 0.2 – 2.5 2.5 – 3 3 - 7 7 – 13 13
Approximately 2” of Topsoil FILL: Brownish Red Sandy Elastic SILT with some Debris (Brick) FILL: Gravel Material FILL: Asphalt Debris with some Wood Debris ALLUVIUM: Moist Light Brown and Gray Silty SAND Rock Test Pit Refused on Rock Groundwater encountered at an approx. depth of 12 feet Test Pit Terminated Depth -13 feet
TP-7
0 – 0.2 0.2 – 4 4 – 6 6 – 8 8 – 14 14 - 16
Approximately 2” of Topsoil FILL: Moist Red Elastic SILT FILL: Brownish Gray Sandy SILT with Organics and some Debris (Brick) ALLUVIUM: Brownish Gray Silty SAND RESIDUUM: Moist Light Gray and Light Brown Sandy Lean CLAY Moist White and Gray Clayey SAND Groundwater Not Observed in Test Pit at Time of Completion Test Pit Terminated Depth -16 feet *Referenced from existing ground elevation Note: Test Pits Performed with a Hyundai 140 LC-9 trackhoe
SUMMARY OF TEST PIT OBSERVATION SHEET 7TH STREET APARTMENTS 705 EAST 7TH STREET CHARLOTTE, NORTH CAROLINA SUMMIT PROJECT NO. 4164.11
Test Pit Number
Depth (feet)*
Soil Description TP-8
0 – 0.2 0.2 – 3 3 - 5
Approximately 2” of Topsoil FILL: Moist Light Brown and Red Sandy Elastic SILT with some Debris (Concrete and Asphalt) RESIDUUM: Red and Yellow Slightly Clayey Sandy SILT Groundwater Not Observed in Test Pit at Time of Completion Test Pit Terminated Depth -5 feet TP-9
0 – 0.2 0.2 – 3.5 3.5 - 5
Approximately 2” of Topsoil FILL: Moist Light Brown and Red Sandy Elastic SILT with some Debris (Concrete and Asphalt) RESIDUUM: Red and Yellow Slightly Clayey Sandy SILT Groundwater Not Observed in Test Pit at Time of Completion Test Pit Terminated Depth -5 feet TP-10
0 – 0.2 0.2 – 4 4 – 6.5 6.5 – 8.5
Approximately 2” of Topsoil FILL: Moist Brownish Red and Red Slightly Clayey Sandy SILT with some Rocks FILL: Brownish Gray (Organic Stained) Sandy SILT with Debris (Wood and Lumber) RESIDUUM: Yellowish Red and Yellow Slightly Clayey Sandy SILT Groundwater Not Observed in Test Pit at Time of Completion Test Pit Terminated Depth -8.5 feet *Referenced from existing ground elevation Note: Test Pits Performed with a Hyundai 140 LC-9 trackhoe
Summary of Additional Geotechnical Services SUMMIT Project No. 4164.11 R.1 7th Street Apartments, Charlotte, NC May 26, 2020

APPENDIX 3
PHOTOGRAPHIC LOGS
Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of Test Pit No. 1

A view of the material excavated from Test Pit No. 1

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of Test Pit No. 2

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of the material excavated from Test Pit No. 2

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of the material excavated from Test Pit No. 2

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of Test Pit No. 3

A view of the material excavated from Test Pit No. 3

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of Test Pit No. 4

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of the material excavated from Test Pit No. 4

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of Test Pit No. 5
Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of the material excavated from Test Pit No. 5

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of Test Pit No. 7
A view of the material excavated from Test Pit No. 7

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of Test Pit No. 8
Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of the material excavated from Test Pit No. 8

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of Test Pit No. 9

A view of the material excavated from Test Pit No. 9

Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of Test Pit No. 10
Photograph Log SUMMIT Project No. 4164.11 7th Street Apartments, Charlotte, NC Taken on May 1, 2020

A view of the material excavated from Test Pit No. 10