ADDENDUM 4 - 7460 - 19830G - Scripture Street Waterline Geotechnical Report
The seal appearing on this
document was authorized by
James F. Phipps, P.E. 84778 on
May 2, 2019.
geotechnical and construction materials consultants
May 2, 2019
Report No. 19830G
Birkhoff, Hendricks & Carter, LLP
11910 Greenville Avenue, Suite 600
Dallas, Texas 75243
ATTN: Mr. Cooper E. Reinbold, E.I.T.
Phone: 214-361-7900
Email: creinbold@bhcllp.com
RE: Geotechnical Investigation
Scripture Street Waterline
Scripture Street and I-35
Denton, Texas
Mr. Reinbold:
Presented herein is the report of a limited geotechnical investigation conducted by Henley-Johnston
& Associates, Inc. for the above referenced project.
We appreciate the opportunity to provide this report to you. If we can be of further service or if
you desire any additional information, please do not hesitate to call.
Signed,
HENLEY-JOHNSTON & Associates, Inc.
Benjamin Clarke, E.I.T. James F. Phipps, P.E.
Project Manager Vice President
Firm Registration No.: F-1238
Copies submitted (2) Birkhoff, Hendricks & Carter, LLP – Mr. Cooper E. Reinbold, E.I.T., Mr. Gary Hendricks, P.E.
Report No. 19830G May 2, 2019
- 1 -
INVESTIGATION AND ANALYSIS
Introduction
This report presents the results of a limited subsurface investigation performed for a proposed
20-inch water line along Scripture Street and Interstate 35 in Denton, Texas.
The purpose of this investigation was to provide information on the anticipated types of materials
to be encountered during installation of the lines and earthwork criteria for backfill of the utility
trench.
This report is specific to this site. Persons using the recommendations herein for projects and/or
designs not covered by this report do so at their own risk.
Field and Laboratory Investigation
Due to the size and layout of the project, subsurface conditions were evaluated with a total of
three soil borings. Two of the borings were located along the west side of Interstate 35 Frontage
Road just north of Scripture Street, while the remaining boring was located along the east side of
Interstate 35 just north of Scripture Street. Locations of the borings were dictated by the client
and site accessibility and are presented on Plate 1. Borings were drilled using a truck-mounted
rig equipped with continuous flight augers and extended to a depth of 15 feet below existing
(April 2019) grades. Drilling and sampling were done in general accordance with ASTM methods
and standards. Relatively undisturbed samples of cohesive soil and weathered shale were
obtained with three-inch diameter thick-walled Shelby tubes. Clay soils were sampled and
evaluated in-situ using Standard Penetration Test (SPT) [ASTM 1586].
All samples were transported to the Henley-Johnston & Associates, Inc. (HJA) laboratory for
visual classification and testing. Soils were visually classified according to the Unified Soil
Classification System (USCS). Rock materials were described using standard geological
nomenclature. The Boring Logs and a key to terms and symbols used on the logs are attached.
Selected samples were tested to confirm visual classification. Tests conducted included
Atterberg Limits (ASTM D-4318) and moisture content determinations (ASTM D-2216). The
strength properties of selected samples were investigated by the Unconfined Compression test
(ASTM D-2166). Results of these laboratory tests are presented on Plates 2 and 3.
Surface and Subsurface Conditions
Surface Conditions
At the time of the field investigation, the majority of the proposed alignment for the water lines
was undeveloped and occupied by existing utilities.
Report No. 19830G May 2, 2019
- 2 -
Geologic Setting
Review of geologic maps indicates the proposed alignment appears to be within the Lower
Cretaceous Grayson Marl and Main Street Limestone Formation, undivided. Subsurface
conditions consisted of fill materials and clay soils over weathered shale.
Subsurface Conditions
Fill materials were encountered at the surface of Boring No. 1. These fill materials consisted of
brown and light brown clay soils that continued to a depth of 1 foot below existing grade.
Residual clay soils were present below the fill materials in Boring No. 1 and at the surface of
Boring Nos. 2 and 3. These clays were dark brown to light brown in appearance, moderately
plastic (CL), contained varying amounts of calcareous particles and limestone fragments, and
continued to depths of 8 to 13 feet below existing grades.
Weathered shale was encountered underlying the clay soils. This weathered shale was soft
(rock hardness classification), laminated in structure, light brown, gray, and dark gray in
appearance, and extended through the termination depth of the borings.
Ground Water
Ground water was encountered in Boring Nos. 1 and 2 during the field investigation at depths of
7 to 8 feet below existing grades, and at depths of 4 to 13 feet below existing grades at end of
day observations. The presence and depth to ground water will vary depending upon seasonal
rainfall amounts. When present, ground water should be expected to perch within the open
cracks and fissures of the overlying weathered rock and overburden soils.
Excavations
Per Federal regulations, any excavation over 20 feet in depth will require an engineered
excavation and safety plan prepared by a licensed engineer. Soils encountered within the
borings consisted of fill materials and CL clays over weathered shale. These soils should be
classified as Type C soils per OSHA Excavation Standards CFR 29, Part 1926, Sub-Part P,
Appendix A. Clay soils along the water lines may be laid back on a temporary slope of
1:Horizontal to 1:Vertical up to a maximum slope height of 20 feet.
For retention system design, these soils may be considered to exert an equivalent fluid pressure
of 45 pcf considering active conditions against any shielding or temporary shoring.
All spoils and construction materials should be kept a minimum of 4 feet from the edge of the
trench. Water should not be allowed to pond along the edge of or within the bottom of the
trench.
Earthwork Recommendations
On-site soils should be placed in maximum eight-inch loose lifts and compacted to a minimum of
95% of the maximum density as determined by ASTM D-698. Moisture content should be at or
above optimum.
Report No. 19830G May 2, 2019
- 3 -
Construction Testing and Observation
It is recommended that all backfill materials within the trench be tested for moisture and density
at a rate of one test per foot of fill for every 300 linear feet of excavation (NCTCOG Public Works
Construction Standards, Fifth Edition – 2017, Item 504.5.3.2). Field density tests should be
taken during placement of trench backfill. Excavating and evaluating fill materials within test pits
should not be permitted. Provisions should be made to permit safe access to the utility trench
during placement of fill to allow for testing of the backfill materials for adequate moisture and
density.
PLATE 1
LEGEND
SOIL BORING
HJA No.:
DATE:
19830G
APRIL 2019
TEXAS FIRM REGISTRATION NO. F-1238 BORING LOCATION PLAN235 MORGAN AVE. DALLAS, TX 75203 I 214.941.3808 I WWW.HJA-ENG.COM
3
SCRIPTURE STREET WATERLINE
SCRIPTURE STREET AND I-35
DENTON, TEXAS
1
2
GEOTECHNICAL INVESTIGATION
REPORT NO. 19830G
SCRIPTURE STREET WATERLINE
SCRIPTURE STREET AND I-35
DENTON, TEXAS
Plate 2
SUMMARY OF INDEX PROPERTIES
BORING
NUMBER
DEPTH
(ft.)
LIQUID
LIMIT
(%)
PLASTIC
INDEX
DUW
(pcf)
FINER
#200
(%)
MOISTURE
CONTENT
(%)
UNIFIED SOIL
CLASSIFICATION
1 0.0 – 1.0 19.7
1 1.0 – 2.0 26.1
1 2.0 – 3.0 26.0
1 3.0 – 4.0 27.0
1 4.0 – 5.0 18.6
1 5.0 – 6.0 24.5
1 6.0 – 7.0 28 13 16.5 CL
1 7.0 – 8.0 110.0 21.0
1 8.0 – 9.0 25.0
1 9.0 – 10.0 17.7
1 14.0 – 15.0 16.1
2 0.0 – 1.0 19.8
2 1.0 – 2.0 21.7
2 2.0 – 3.0 49 33 103.3 22.7 CL
2 3.0 – 4.0 22.7
2 4.0 – 5.0 22.5
2 5.0 – 6.0 23.6
2 6.0 – 7.0 18.8
2 7.0 – 8.0 18.8
2 8.0 – 9.0 21.4
2 9.0 – 10.0 20.6
2 14.0 – 15.0 112.4 19.5
3 0.0 – 1.0 22.7
3 1.0 – 2.0 24.6
3 2.0 – 3.0 21.5
3 3.0 – 4.0 20.5
3 4.0 – 5.0 16.3
3 5.0 – 6.0 19.2
3 6.0 – 7.0 13.9
GEOTECHNICAL INVESTIGATION
REPORT NO. 19830G
SCRIPTURE STREET WATERLINE
SCRIPTURE STREET AND I-35
DENTON, TEXAS
Plate 3
SUMMARY OF INDEX PROPERTIES
BORING
NUMBER
DEPTH
(ft.)
LIQUID
LIMIT
(%)
PLASTIC
INDEX
DUW
(pcf)
FINER
#200
(%)
MOISTURE
CONTENT
(%)
UNIFIED SOIL
CLASSIFICATION
3 7.0 – 8.0 16.0
3 8.0 – 9.0 21.7
3 9.0 – 10.0 67 48 109.0 20.1 CH
3 14.0 – 15.0 18.0
SUMMARY OF UNCONFINED COMPRESSION TESTS - SOIL
BORING
NUMBER
DEPTH
(ft.)
PEAK
STRESS
(psi)
FAILURE
STRAIN
(%)
MATERIAL DESCRIPTION
1 7.0 – 8.0 19.8 6.3 CLAY, stiff to very stiff, brown and light brown
2 2.0 – 3.0 21.7 9.0 CLAY, very stiff, dark brown and brown
2 14.0 – 15.0 33.1 5.8 SHALE, weathered
3 9.0 – 10.0 31.1 5.3 SHALE, weathered
Strata symbols
FILL
LOW PLASTICITY CLAYS,
SANDY CLAYS, OR GRAVELLY
CLAYS (CL)
SHALE, weathered
Misc. Symbols
Ground Water During Drilling (ft)
Pocket Penetrometer (tsf)
Standard Penetration (BPF)
Soil Samplers
Undisturbed thick wall
Shelby tube
Split Spoon
LEGEND, LITHOLOGY, SOIL CONSISTENCY
& RELATIVE ROCK HARDNESS
# OF BORINGS:3
PROJECT No.:19830G
Scripture Street Waterline
Scripture Street and I-35
Denton, Texas
DRILL DATE:4/23/19
TEXAS FIRM REGISTRATION NO. F-1238 METHOD:Shelby Tube to 15'
asdf
FOR SANDS, GRAVELS, & SANDY SILTS FOR CLAYS AND SANDY CLAYS
Modified from Peak, Hanson & Thornburn (1974)
(COHESIVE SOILS)
Modified from Peak, Hanson & Thornburn (1974)
Consistency Standard Penetration Resistance
(N)
Consistency Unconfined
Compression (tsf)
Standard
Penetration
Resistance (N)
Very Soft Less than 0.25 Less than 2
Very Loose Less than 4
Soft 0.25 to 0.5 2 to 4
Loose 4 to 10
Medium Stiff 0.5 to 1.0 4 to 8
Medium Dense 10 to 30
Stiff 1.0 to 2.0 8 to 15
Dense 30 to 50
Very Stiff 2.0 to 4.0 15 to 30
Very Dense Greater than 50 Hard Greater than 4.0 Greater
than 30asdfasdf
RELATIVE HARDNESS MODIFIERS (ROCK)
(RELATED TO FRESH SAMPLE)
Modified from SCS EWP, Tech Guide No. 4
Hardness Rule of Thumb Test
Soft Permits denting by moderate finger pressure
Resists denting by fingers but can be penetrated
by pencil point to medium to shallow depth (No. 2 pencil)Firm
Very shallow penetration of pencil point, can be
scratched by knife and in some instances cut with knifeMod. Hard
Hard No pencil penetration, can be scratched with knife,
can be broken by light to moderate hammer blows
Very Hard Cannot be scratched by knife, can be broken
by repeated hammer blows
asdf
0
3
6
9
12
15
18
21
FILL: CLAY, stiff, brown and light brown
CLAY, calcareous, very stiff, dark brown
CLAY, with limestone fragments, stiff to very stiff, brown and light
brown
SHALE, weathered, laminated, soft, dark gray
TOTAL DEPTH: 15.0'
2
LOG OF BORING PROJECT No.:19830G
Scripture Street Waterline
Scripture Street and I-35
Denton, Texas
BORING No.:1
STATION:
DRILL DATE:4/23/19 SHEET:1 of
METHOD:Shelby Tube w/Split Spoon to 15'LOCATION:See Plate 1
GROUND ELEVATION:
Ground Water During Drilling (ft.):7'
dfs
Ground Water After Drilling (ft.):4'DEPTH(feet)SYMBOLSAMPLESMATERIAL DESCRIPTION
ELEVATION(feet)RECOVERED (ft.)CORE
RQD (%)1 2 3 4 +++POCKET PENETROMETER (tsf)
10 20 30 40 50 60STANDARD PENETRATION (BPF)
1 2 3 4 5 6
TxDOT CPT (inches per 100 blows)
1
0
3
6
9
12
15
18
21
CLAY, calcareous, very stiff, dark brown and brown
CLAY, with calcareous nodules, very stiff, brown and light brown
SHALE, weathered, laminated, soft, light brown and gray
TOTAL DEPTH: 15.0'
LOG OF BORING PROJECT No.:19830G
Scripture Street Waterline
Scripture Street and I-35
Denton, Texas
BORING No.:2
STATION:
DRILL DATE:4/23/19 SHEET:1 of
METHOD:Shelby Tube to 15'LOCATION:See Plate 1
GROUND ELEVATION:
Ground Water During Drilling (ft.):8'
dfs
Ground Water After Drilling (ft.):13'DEPTH(feet)SYMBOLSAMPLESMATERIAL DESCRIPTION
ELEVATION(feet)RECOVERED (ft.)CORE
RQD (%)1 2 3 4 +++POCKET PENETROMETER (tsf)
10 20 30 40 50 60STANDARD PENETRATION (BPF)
1 2 3 4 5 6
TxDOT CPT (inches per 100 blows)
1
0
3
6
9
12
15
18
21
CLAY, calcareous, very stiff, dark brown and brown
CLAY, with calcareous nodules, very stiff, light brown
SHALE, weathered, laminated, soft, light brown and gray
TOTAL DEPTH: 15.0'
LOG OF BORING PROJECT No.:19830G
Scripture Street Waterline
Scripture Street and I-35
Denton, Texas
BORING No.:3
STATION:
DRILL DATE:4/23/19 SHEET:1 of
METHOD:Shelby Tube to 15'LOCATION:See Plate 1
GROUND ELEVATION:
Ground Water During Drilling (ft.):DRY
dfs
Ground Water After Drilling (ft.):DRYDEPTH(feet)SYMBOLSAMPLESMATERIAL DESCRIPTION
ELEVATION(feet)RECOVERED (ft.)CORE
RQD (%)1 2 3 4 +++POCKET PENETROMETER (tsf)
10 20 30 40 50 60STANDARD PENETRATION (BPF)
1 2 3 4 5 6
TxDOT CPT (inches per 100 blows)
1