DR9306-SY 960111 Consultants
CHANNEL BANK STABILITY
STREAM G-6/BETHEL SCHOOL ROAD
COPPELL, TEXAS
January 11, 1996
10555 Newkirk Street
Suite 530
Dallas, Texas 75220
214.831.1111
FAX 214.831.0800
The City of Coppell
255 Parkway Blvd.
_ P.O. Box 478
Coppell, Texas
-- Attn.: Kenneth M. Griffin, P.E.
Assistant City Manager
City Engineer
Re: Geotechnical Investigation Services
Channel Bank Stability
-- Stream G-6/Bethel School Road
Coppell, Texas
PBT Project No. 101-002
Dear Mr. Griffin:
Patton, Burke & Thompson (PBT) has completed a geotechnical investigation for a portion of the above
referenced channel bank and hereby submit our findings and conclusions. This assignment was carded out in
_ general accordance with our discussions and PBT's proposal dated October 12, 1995.
Our firm appreciates the opportunity to be of professional geotechnical engineering service to the City, and
_ particularly the assistance provided by you and your staff. We would be pleased to discuss any questions which
may arise concerning this report. If we can be of further assistance, please contact us.
-- Respectfully submitted,
PATTON, BURKE & THOMPSON
Che-Hung Tsai, Ph.D. Jack W. Burke, P.E.
Staff Engineer Principal
CHT/JWB/jp
101-002.rpt
Pat~on, Burke d~ Thompson
Engineering Consultants
GEOTECHNICAL INVESTIGATION SERVICES
_ CHANNEL BANK STABILITY
STREAM G-6/BETHEL SCHOOL ROAD
COPPELL, TEXAS
TABLE OF CONTENTS
-- PAGE
10 INTRODUCTION .................................................. 1
1. I GENERAL ................................................... 1
-- 1.2 SCOPE OF WORK ............................................ 1
1.3 REPORT OUTLINE ........................................... 2
2.0 AVAILABLE INFORMATION ....................................... 2
3.0 SUBSURFACE INVESTIGATION .................................... 3
3.1 FIELD INVESTIGATION ....................................... 3
3.2 LABORATORY TESTING ...................................... 3
4.0 GEOLOGY AND SITE CONDITIONS ................................. 4
4.1 SITE GEOLOGY .............................................. 4
-- 4.2 SITE SURFACE CONDITIONS .................................. 4
4.3 GENERAL SUBSURFACE CONDITIONS ......................... 6
-- 5.0 FINDINGS AND ANALYSES ......................................... 7
5.1 GENERAL ................................................... 7
5.2 CHANNEL BANK STABILITY .................................. 7
-- 5.3 RESDENCE POTENTIAL VERTICAL MOVEMENTS ............... 9
6.0 CONCLUSIONS .................................................. 10
7.0' LIMITATIONS ................................................... 11
LIST OF FIGURES
-- BORING LOCATION PLAN: ....................................... FIGURE 1
SURVEY & X-SECTION LOCATIONS ............................... FIGURE 2
_ CROSS SECTIONS ........................................... FIGURES 3-5
WATER CONTENT/PI PROFILE: .................................... FIGURE 6
RESULTS OF SUCTION TEST: .............. : ...................... FIGURE 7
APPENDIX A
-- LOG OF BORINGS: ......................................... FIGURES Al-A7
APPENDIX B
LABORATORY TEST RESULTS ............................... FIGURES B 1 oB9
Pa*ton, Burke & Thompson
Engineering Consultants
APPENDIX C
PHOTOGRAPHS ......................................... FIGURES C1-C6
Patton, Burke & Thompson
Engineering Consultants
-- GEOTECHNICAL INVESTIGATION SERVICES
CHANNEL BANK STABILITY
-- STREAM G-6/BETHEL SCHOOL ROAD
· COPPELL, TEXAS
1.0 INTRODUCTION
1.1 GENERAL
This report presents the results to date of certain geotechnical engineering services performed by Patton, Burke
& Thompson (PBT) for a portion of the west bank (approximately between Station 8+50 and 11+00) of Stream
G-6/Bethel School Road Drainage Improvement Project, in the Northlake Woodlands section of the City (hereafter
in the report referred to as the "study site"). The study site also forms the east property line of the Don Jones
property located at 632 Bethel School Road in Coppell, Texas. The report has been prepared and the investigation
_ was carried out in general accordance with PBT's proposal dated October 12, 1995, which was approved on
November 6, 1995 by the City of Coppell. The subject study site is located in Dallas County immediately north
-- of the intersection of Bethel School Road and Swan Drive, shown in Figure 1.
-- The home at the study site was constructed in 1987, and was occupied by the Jones' family around May 1987. It
is PBT's further understanding that the home was built by Lewis Crump, the basic foundation was a post-tensioned
-- slab-on-grade, the site was a cut/fill pad (i.e., cut on the north and fill to the south and east), the swimming pool
on the east side was added in July 1988, and other miscellaneous items (e.g., fences, landscaping, small retaining
-- walls, etc.) have ben added over the years. Although there is considerable detail on the history of the construction
of the Stream 0-6 new drainage improvements, the primary purpose of this study is to assist, from a geoteclmical
engineering viewpoint, the City in quantifying what caused study site movements noted by PBT during their initial
site visit on October 5, 1995, and developing alternatives on how to stabilize the study site.
1.2 SCOPE OF WORK
Patton, Burke & Thompson received an inquiry from a representative of the City of Coppell and made an initial
site visit on October 5, 1995, in reference to performing certain geotechnical engineering consulting services in
·
The basic services of PBT to date have I
regard to the slope stability and movement problems at the Jones property.
I
Patton, Burke & Thompson
Engineering Consultants
Stream G-6/Bethel School Road
Page 2
involved review of certain project information, property site visits, discussions with homeowner Don Jones and city
representatives, geotechnical field and laboratory investigations, engineering analysis, and the preparation of this
_ report.
1.3 REPORT OUTLINE
_ The remaining portions of this report generally follow an outline which includes a presentation of, specifically as
relates to geotechnical engineering aspects of the observed study site movements, pertinent available information,
- visual observations during site visits, area geology, site surface and subsurface conditions, findings and analysis,
and conclusions.
- 2.0 AVAILABLE INFORMATION
-- Although various drawings, personal discussions with various individuals (including Mr. JOnes), and other project
information has been provided to PBT to assist us in performing our services to date, the review of such
-- information has been focused on and was specifically in regard to evaluating geotechnical engineering aspects of
the observed movements. However, some of the more useful information/data reviewed for this study included the
following:
-- 1. Copy of Plan No. 4454 of the subject residence, 4-sheets.
2. USGS Quad, Carrollton sheet, 1959 (photorevised 1981).
3. Map (2-foot contour intervals), City of Coppell, Texas, prepared by G-inn, Inc., Consulting
Engineers, Dallas, TX, Sheet No. 21 (undated).
4. "Construction Plans for Stream G-6/Bethel Schoo1 Road, Drainage Improvements/DR 93-06 in
_ Northlake Woodlands, City of Coppell, Texas", prepared by O'Brien Engineering, dated September
1994, Sheets 1/11 thru 6/11.
_ 5. Cross Sections of Stream G-6 (Sta. 0+34.7 thru Sta. 2+50), prepared by the City of Coppell, project
No. DR 93-06, December 1995, sheets 1 and 2.
Patton, Burke & Thompson
Engineering Consultants
Stream G-6/Bethel School Road
Page 3
3.0 SUBSURFACE INVESTIGATION
3.1 FIELD INVESTIGATION
_ Six (6) exploratory borings were drilled by PBT to specifically investigate subsurface conditions, at the study site
and in a more general nature the subsurface conditions around the south end ofthe residence.. All borings were
_ drilled and sampled using portable drilling equipment, mainly due to site accessibility. Two (2) borings (PBT-1 and
PBT-2) were advanced to a depth of 12-feet through the pool deck concrete slab on top of the bank, one (1) boring
- (PBT-3) was advanced to a depth of 1 O-feet on the bank about 6-feet behind the new gabion wall, and (1) boring
(PBT-4) was taken to a depth of 12-feet on top of the bank in the grassy area south of the pool. Two borings
- (PBT-5 and PBT-6), immediately outside the south side of the house, were advanced to depths of 12-feet and 10-
feet, respectively. Sampling was supervised and logging performed by a PBT representative. The location of the
- borings are shown graphically on Figure 1, summary Logs of Borings and the classification system used for
encountered soils are presented in Appendix A.
Relatively undisturbed soil samples from the borings were obtained using a thin walled, seamless Shelby tube
-- sampler pushed continuously into the ground. Shelby tube samples were evaluated for shear strength in the field
with a pocket penetrometer. A portable dynamic cone penetrometer was also used to approximate the standard
-- penetration resistance (i.e. N-values) of near surface soils. Samples of the subsoils were visually classified, carefully
wrapped, sealed, marked, and transported to the PBT laboratory. Borings PBT-1 and PBT-2 which were advanced
through the concrete deck slab, were backfilled with soil cuttings and the slab patched with cement. All other holes
of the exploratory borings, PBT-3 through PBT-6, were backfilled with soil cuttings before leaving the site
3.2 LABORATORY TESTING
Soil samples obtained from the borings were observed and classified by an experienced geotechnical engineer in
PBT's laboratory. To aid in classifying the soils and determining their general engineering characteristics, moisture
_ content (ASTM D-2216), dry unit weight, Atterberg limits (ASTM D-4318), minus No. 200 (ASTM- 1140), and
grain size analysis (ASTM D-422) were performed on selected samples. Overburden swell tests (ASTM D-4546-b)
-- were performed on samples from Boring PBT-5 at depths 2-3 ft. and 10-11 fi. to obtain a better understanding of
the swelling characteristics of the subsurface soils in the immediate vicinity of the house structure. Seven (7) filter
1
Patton, Burke & Thompson
Stream G-6/Bethel School Road
Page 4
paper suction tests (ASTM D-5298) were performed to measure the suction of selected samples which can be used
to help evaluate the depth of wetting and prediction of potential heave of on-site expansive clay soils
Direct shear tests (ASTM D-3080) were conducted on samples from the study site area to evaluate the shear
_ strength properties of clay soils. Also, triaxial compression - unconsolidated undrained tests (ASTM D-2850) were
conducted on undisturbed Shelby tube samples from Boring PBT-1 at depth interval of 3 to 4-feet, Boring PBT-2
_ at depth interval of 7 to 8-feet, and Boring PBT-3 at depth interval of 3 to 4-feet to evaluate the short-term shear
strength properties of the on-site clay soils.
Results of all laboratory tests for classification and identification are provided on Log of Boring sheets, Appendix
-- A. A summary of laboratory testing results, unconsolidated undrained triaxial, direct shear, grain size distribution
analysis, and overburden swell tests are presented in attached Appendix B.
-- 4.0 GEOLOGY AND SITE CONDITIONS
4.1 SITE GEOLOGY
Site geology, based on published geological information, visual observations and PBT's experience in the general
area, consists of Eagle Ford Shale formation and/or local areas of man-made fill. The Eagle Ford Shale formation
comprising of clays (especially the typical upper zone of residual soil) are highly expansive and capable of causing
significant soil movements and foundation related distress. These typical local natural geologic conditions were
not supported by the subsurface conditions identified by PBT exploratory borings (with the exception &Boring
PBT-2 below a depth of g-feet), because the depth of most of the relatively shallow borings used for this
investigation encountered man-made fill materials.
4.2 SITE SURFACE CONDITIONS
The overall site, sloping downward from the north toward the south and from the west toward east, is located at
632 Bethel School Road in Coppell, Texas (Figure 1). Original grading plans (i.e., before home was constructed)
were not available for review; however, the overall appearance of the general area indicates the site contains a
Patton, Burke & Thompson
Engineering Consultants
Stream G-6/Bethel School Road
Page 5
variable depth of man-made fill soils. Surrounding landscaping is quite extensive and consists of grass, shrubs and
-- trees, and small rock and/or wood retaining walls. A swimming pool was constructed in mid-1988 to the east of
the main residence, and the new drainage channel was located as generally shown in Figure 1. At the time ofPBT's
-- second site visit on November 10, 1995, the drainage channel was wet with a small amount of upstream drainage
(see Photos 1 and 3, Appendix C) and the swimming pool was filled with water (Photo 5). The current
-- homeowner (Mr. Don Jones) has indicated that since early May 1995 his pool and adjoining concrete deck has
experienced both vertical and lateral movements. Vertical and lateral movements of the concrete deck slab around
the pool were evident and noted by PBT on November 10, 1995, and were measured by the City's survey crew
during the week of December 18, 1995 (see Figure 2). In addition, southward of the Jones's pool area several
continuous ground cracks (tension cracks) were noted paralleling approximately 8' to 10' behind (westward) the
top of the subject bank slope.
It is known that overall construction for the drainage improvement project was started in late-1994 and primarily
involved excavating a new pilot channel, construction of a new channel concrete bottom, and backfilling behind
a new channel bank wall consisting of rock filled gabion. Although there is considerable detail on the construction
ofthe subject new drainage improvements, reportedly around the first week of May 1995 heavy rainfall, runoff and
bank scour was experienced at the site (particularly in the approximate vicinity of Station 11+00 thru 9+50-~).
Shortly thereafter, reported as around May 10th, the project's general contractor 0VI. A. Vinson of Fort Worth)
_ installed heavy steel sheet piling along a portion of the subject bank a few feet behind the previously constructed
gabion wall. The exact length, depth and location of this sheetpiling is not available, but it was roughly along the
_ alignment of the original upper railroad-tie wall in the area (see photo's 2 and 4).
- It is reported that the residence structure itself is founded on a post tensioned slab-on-grade foundation with brick
veneer walls. It is also reported by the homeowner that the house has experienced differential movements in the
- past. External and internal signs of distress and movement were visible during PBT's November 10, 1995 site visit
in the floors, walls and ceilings, generally in a zone starting in the shared bathroom between bedrooms 2 and 3 and
- projecting northeastward through the fireplace in the master bedroom. The observed cracks are classified as slight
to small.
Pn~*on, Burke & Thompson
Engi, eeri, g ¢o,sultmJts
Stream G-6/Bethel School Road
Page 6
4.3 GENERAL SUBSURFACE CONDITIONS
Man-made fill was found at the site in all six (6) borings (see Appendix A). In Borings PBT-1 and PBT-2, on top
of the bank in the study area near the pool, the fill material was comprised of a dark gray to dark brown clay, sand
_ and gravel to depths of 5 to 7-feet below existing grade (i.e., top of concrete deck). A pocket of loose fine sand,
brownish yellow, was noted at a depth about 1-foot in these two borings, PBT-1 and PBT-2. The upper fill
_ materials in Borings PBT-4 through PBT-6 was dark brown, and comprised of clay as well as gravel to depth about
1 -foot below existing grade, and was underlain by brownish yellow, greenish gray to gray, sandy clay materials
-- which are suspected of being original site development fills. A 5.5-feet deep backfill material, sandy clay to clayey
sand with traces of gravels, was noted in Boring PBT-3 about 6-feet behind the face of the new gabion wall.
- Generally speaking, all of the fill materials varied widely from soi~ to very stiffand moist to very moist. Atterberg
limits tests pen°ormed on selected samples indicated an average liquid limit of 44 percent, average plasticity indices
-- of 22 percent, and average 48 percent passing the No. 200 sieve.
-- The typical underlying natural geologic conditions (i.e., Eagle Ford clays) were supported only by the subsurface
condition identified by exploratory boring PBT-2. The existing subsurface conditions, as interpreted from the
boring location and depth penetrated by Borings PBT-2, can be considered as one (1) natural stratum as follows:
· Underlying the fill material was a sandy to silty clay with gravel to the maximum depth of boring penetration
of 12-feet. The clay was stiff to very stiff, moist to very moist, and brown, brownish yellow, as well as
greenish gray in color. Atterberg limits tests performed on selected samples indicated average liquid limit
of 82 percent, average plasticity indices of 52 percent, and average 91 percent passing the No. 200 sieve.
The moisture content were around 29 percent and the dry unit weight around 93 pcf. This clay has high
_ potential for volume change and can be classified as CH material.
_ Groundwater was found only in Boring PBT-3 at 9.5-feet at the time of drilling and at a 6-feet, 2 hours after
completion. However, the local groundwater conditions can be expected to fluctuate, due to the varying
_ characteristics of the fill subsoils, seasonal variations in precipitation and existing site surface runoff'features.
-- The boring logs included with this report (Appendix A) presents the summary subsurface conditions encountered
at the specific locations explored. The generalized stratification discussed above represents interpretive soil
- _l
Patton, Burke d~ Thompson
Engineering Consultants
Stream G-6/Bethel School Road
Page 7
conditions encountered at the study site. It is recommended that the individual boring logs be referred to for more
detailed information of the specific locations explored.
__ 5.0 FINDINGS AND ANALYSIS
-- 5.1 GENERAL
-- Subsurface conditions, as indicated by the borings, consisted generally of original site development man-made fills,
underlain by natural clay soils at depth. One basic exception was the fill materials encountered in Boring PBT-3
-- which is interrupted to be recent backfill materials from the gabion wall construction activities. Groundwater was
encountered at a depth of 9.5-feet at the time of drilling in Boring PBT-3 and all other borings were dry. The clay
-- fill subsoils with gravel, and occasionally gravelly, are considered to have low to moderate potential for volume
change and can be generally classified as CL material. In the analyses which were performed for this study, Borings
-- PBT-1 through PBT-4 in the bank area were used to analyze slope stability and lateral displacements in the bank
study area, and Borings PBT-5 and PBT-6 outside the south end of the house were used in the evaluation of
potential heave or settlement movements.
5.2 CHANNEL BANK STABILITY
An analysis of the stability of the west bank of the new G-6/Stream Channel involved a reconstruction of the
original topography, both before and after the site development activities for the Jones residence and pool areas,
and its relationship to the excavations during construction of the subject stream channel. Combining information
from area USGS topo maps, city topo maps (both past and recent), construction plans £or the recent wall
construction and findings in the study area test borings, the general surface topography for various times were
_ reconstructed for the study area. Numerous subsurface cross sections were developed through the study site area
(primarily in the stream interval of station 9+75 through 10+25) which were utilized to perform stability and/or
-- movement analysis. Field measurements during the boring program and laboratory test results, combined with
experience, were then utilized to select appropriate soil mechanic properties for all subsurface materials. In
- addition, the existing pool was assumed full of water and not leaking to any degree that would affect gross stability
of the streams west bank.
Patton, Bnrke d~ Thompson
Engineering Consultants
Stream G-6/Bethel School Road
Page 8
Numerous stability conditions were analyzed for the slope of the stream's west bank. A modified Bishop method
was utilized for analysis. The analysis includes typical circular shaped failure surfaces. The analyses are performed
_ with the aid of a computer program (GEOSLOPE) to analyze multiple interactions to estimate the critical failure
surface. The critical failure surface is defined as the circular arc with the lowest factor of safety for the given
_ stability conditions. The stability conditions selected for final analysis included three (3) different stages during the
life of the slope at each of three (3) x-section locations though the study area. The three locations are at recent
_ survey stations 1+00, 1+50 and 2+00, shown on Figure 2. The three stages were: 1) before construction of
drainage channel O.e., generally conditions along bank immediately prior to construction of new channel), 2) during
- construction of drainage channel, and 3) after construction of drainage channel (generally current conditions). Both
before and after construction of drainage channel can be considered (from a geotechnical engineering state of stress
- condition) as a long-term condition, however, during construction of drainage channel was analyzed as is a short-
term condition.
The summary of results of analytical stability analysis for the selected three stations at three different stages are
- shown in Figures 3 and 4 for the stream bank in the general vicinity of the pool, and on Figure 5 for the general
bank area south of the pool.
The findings of the slope stability analysis for the three (3) selected cross sections indicate that the calculated factor
of safety, at all cross sections, was substantially reduced between the "before construction" and "during
construction" stages as follows (see Figure 1 for location of cross sections):
· Station 2+00, bank/pool area (Figure 3) - critical factor of safety was calculated to be 1.9 for the before
construction condition and 1.4 during construction. This reduction in factor of safety was heavily
influenced by the depth of cut for the profile of the new channel and the general steepening of the cut slope
to allow construction of the new gabion wall.
· Station 1+50, bank/pool area (Figure 4) - critical factor of safety was reduced from 2.2 to 1.2 between the
_ before construction and during construction stages. This cross section, as indicated on Figure 4, is also
impacted by the deep excavation for the new channel profile, but also is a location where a section of the
-- old, upper wood retaining wall remains which results in a relatively steep average final slope.
Patton, Burke & Thompson
Engineering Consultants
Stream G-6/Bethel School Road
Page 9
· Station 1+00, bank area (Figure 5) - the critical factor of safety is reduced from 2.9 to 1.7 between the
before construction and during construction stages. This analysis also factored in the case of the currently
observed tension crack which has a tendency to lower the average factor of safety for the during
construction stage. Again, this cross section is impacted for the during construction stage primarily by the
excavation of the new channel profile.
_ The study analysis also evaluated the critical factor of safety at the three (3) cross sections for the "after
construction", or current, stage. These analyses indicate a range of critical factor of safety of 1.1 to 1.3 as indicated
_ on Figures 3, 4 and 5. These critical factors of safety are generally lower than the during construction stage
because the analysis takes into account parameters for a long-term condition whereas the parameters for the during
_ construction are considered short-term. In addition, the calculated critical factors of safety for the after
construction stage is considered slightly conservative due to the presence of the reinforced concrete channel bottom
-- which was not accounted for in the analysis. This factor, however, should not increase the critical factor safety
more than 0.1 to 0.2. Also, as noted on figures 3, 4 and 5, the failure surfaces which pass immediately above the
- concrete slab (for the after construction case) may have a factor of safety slightly less or equal to those passing
below the gabion walls.
5.3 RESIDENCE POTENTIAL VERTICAL MOVEMENTS
As discussed earlier both external and internal signs of distress and movement have been observed at one particular
location in the southern area of the structure. The primary purpose of Borings PBT-5 and PBT-6 was to collect
samples of the subsurface materials so that their potential for vertical movements could be evaluated.
Based on the laboratory test results, Figures 6 and 7 illustrates the plots of water content/PI, suction and water
content with depth below current existing grade. It appears from these relationships that the depth of active zone
is most likely to be located around 10-feet.
Four (4) different calculation methods were used to estimate vertical movements near the southern end of the
residence. The firs~ method, utilizing one dimensional laboratory swell testing data (Figures B8 and B9 in Appendix
_ B), show slight vertical movements from the selected test specimens. An empirical method, developed by the Texas
Highway Department's TI-ID test method (TEX-124-E) and locally referred to as "PVR", indicated low potential I
I
Pa*ton, Burke & Thompson
Engineering Consultants
Stream O-6/Bethel School Road
Page 10
movement, less than 1-inch. A suction approach calculation method, developed by Dr. Gordon McKeen, University
of New Mexico, indicated a potential movement of between 2 to 2-1/2-inches under current subsoil conditions.
Also, the VOLFLO computer program, developed primarily by Texas A&M University, was used to estimate
potential vertical movements. Depending on the parameters selected to model the' seasonal moisture variation, total
swell potential for the existing site clay soils ranges from 1-1/4 to 1-3/4-inches, and the range of total shrinkage
(i.e., settlement) potential due to the existing large trees (see Photos 6 and 7 in Appendix C) ranges from 1-1/2 to
2-inches.
6.0 CONCLUSIONS
The findings and analysis of the observed distress damage at the subject Jones study site and residence, as
- specifically relates to the geotechnical engineering aspects of this study, are based primarily on the provided
available information, site observations, geotechnical investigations and our past experience with construction
- activities and slope stability problems. The findings and analysis, in our opinion, are adequate to form a professional
basis for a conclusion on the basic question of "Did the construction activities for the new stream G-6 channel
-- improvements cause the observed study site movements (i.e., the pool area) and/or the observed signs of distress
and movement in the main house?".
In conclusion, the observed movements and distress, in our opinion, can be attributed to the following main factors
or conditions:
1. Existing subsurface conditions, at both the bank/pool study area and the main residence, consist of a
significant depth of old, man-made fills which due to their variability are susceptible to movements (both
vertical and horizontal) over time.
2. Extensive landscaping, several large mature trees and irrigation watering systems throughout the property
creates major oppommities for large seasonal variations in water contents of subsurface man-made fill
materials.
Pa,*on, Burke & Thompson
Engineering Consultants
Stream G-6/Bethel School Road
Page 11
3. Construction activities for the G-6 Stream drainage improvement project did lower the critical factor of
safety for bank stability at the study site, both for the during construction and the after (current)
construction conditions.
_ 4. Although the factor of safety for gross stability at the study site was reduced during construction, the
created critical factor of safety is still considered adequate for normal, relatively short-term construction
_ periods. Furthermore, these reduced factors of safety (generally in the range of 1.2 to 1.4) did nOt within
themself create an unstable bank and the resulting observed movements and distress.
5. Although the reduced long-term after construction stability of the existing bank has also been reduced (i.e.,
- as compared to the original before construction condition), the current critical factor of safety is greater
than unity (i.e., 1.0) and is not the cause of the observed distress and movements to date. However, due
-- to the normal practice that the critical long-term factor of safety for bank stability should be at least 1.5,
the current factor of safety for the west bank of the G-6 Stream (,particularly in the study site area) is
-- considered inadequate.
-- 6. Observed movement and cracking distress to-date for the main residence was not caused by the
construction activities for G-6 Stream drainage improvements. Furthermore, the subject cracking distress
-- and movements in all probability are the result of past shrinkage settlement of the structure foundation due
to the large, mature trees in the near vicinity.
7.0 LIMITATIONS
This study is limited in that the findings and analysis rely upon information provided by City as well as others and
the geotechnical invegtigationa performed by PtlT several months at'er the movements actually occurred.
Therefore, should any conditions other than those described in this report be encountered or be known by others
to exist, it is recommended that Patton, Burke & Thompson be notified so that supplemental interpretations, if
required, can be provided.
Patton, Burke & Thompson
Stream G-6/Bethel School Road
Page 12
The findings, analysis and conclusions presented in this report are based on the assumption that subsurface
conditions do not vary appreciably from those encountered at the borings. Furthermore, the subsurface information
presented in this report does not constitute a direct or implied warranty that the subsurface conditions at the boring
locations can be directly interpolated or extrapolated.
Patton, Burke & Thompson has prepared this report to assist the City of Coppell in their evaluation of the study
site. We have developed our findings and conclusions in accordance with locally accepted professional geotechnical
engineering principles and practices at the time of the investigation. We make no other warranty either express or
_ implied. Our analyses are based on the results of the field exploration, laboratory tests, analysis, and our
interpretations of subsurface conditions.
Burke & Thompson
FIGURES
Sandy Lake Eo&d
Stream O~"'~.~_
(D r~h~...x~....'
~ ~ Vicinity Map
Jones Residence
632 Bethel School Rood
Coppell, Texas
PBT-6
- Entry
_ ,
Bethel School Road
Note: Drawing Not To Scale BORING LOCATION PLAN
_ · indicates approximate location
of exploratory boring Channel Bank Stability
Stream G-6/Jones Residence
Job No. 101-002 Coppell, Texas
_ Patton, Burke & Thompson Figure
I1
Jones Residence
NORTHLAKE WOODLANDS EAST PH. VI' -~
LOT 9-R, BLOCK J
475.18
475.25 STA. 2+00 '
~PA
STA. 1+50
STA. 1+50
.73 Dca<
¢72.70
t74.67
472;7,~
STA. 1+00 !.72
Station 1+00 from this
survey is approximately
Station 9+40 for the .472.54
Stream G-6 construction 472.72 472.33
plans dated September 1994.
472.61 ' ,
~ :'472..63
472.56 --472,70
472~60 ~ 472.56
472,62 ' × 47Z49~ 472::56 :: 472,51
472.52
\ ,
Scale: 1" - 12.5'
469 83
/ Note: Information on this figure taken
from City of Coppell's Sheet 1
of 2 for Project No. DR 93-06.
Survey performed week of December
463.29 18, 1995.
459.11
458.75
10' CON~,RE~ t~-Ut~ ___ "-- --'
\ -
i '~-4:64-~0 - TO~ ~^e~o. W^LL 463.27 \.'~ ~..,
i × 464.80
464!77
SURVEY & X-SECTION LOCATIONS
""~ Sra. 1+00, 1+50 and 2+00
Channel Bank Stobility
Stream G-6/Jones Residence
Job No. 101-002 Coppell, Texas
Potion, Burke & Thompson Figure 2
(orifin&l site development)
A: FILL B: CLAY, sandy
r= I20 pcf r= I25 pcf
C= 120 psf C= 200 psf
es= 15° es= 20° __~
Critical F.S.-- 1,9
Pool A
Lt.Jeol F-flute Pl.,ne
B
A: FILL B: CLAY, sandy
r= 120 pcf r= 125 pcf
C= 200 psf C-- 300 psf
~= 10° ~= 12° /.~-~-------~ / ~ Critical F.S.= 1.4
A
Pool
Channel lr~
During Cons±r'uction (S±o, ~)+00)
No. (2) failure plane
A: FILL B: CLAY, sandy ~l (1). Critical F.S.= 1.3
r= 120 pcf r= 125 pcf J v
C= 60 psf C= 200 psf I Pool A (2). Critical F.S.= 1.1
~= 16° ~= 18°
C: FILL (wall backfill)
r= 120 pef
C= 50 psf
~= 15° No. (1) failure plane
AF±er Consiructiom (Sic, 2+00)
Bank / Pool Area
D: Cabions Wall (2'x2') CROSS SECTION
(Properties assumed strong
enough so as not to affect AT STATION 2+00
analysis results)
Scale: ] Channel Bank Stability
Stream g-6/Jones Residence
Job No. 101-002 o 15-feet Coppell, Texas
Parian, Burke & Thompson Figure 3
A: FILL B: CLAY, sandy r= 120 pcf r= 125 pcf
Critical
1.2
C= 200 psf C= 300 psf
¢=10° ¢=12'
0ri[inml Ground .....
B
Channel Area /
During Construction (S¢o, 1+50)
Edge of house
No. (2) failure plane
A: FILL B: CLAY, sandy
r= 120 per r= 125 pcf (1). Critical F.S.= 1.1
C= 60 psf C= 200 psf A (2) Critical F.S.= 1
¢=16° ¢=18° ~ .. ·
B
C: FILL (wall backfill)
r= 120 per
C= 50 psf No. (1) failure plane
0=15o APter Cons±ruction (S~o. 1+50)
Bank / Pool Area
D: Gabions Wall (2'x2') CROSS SECTION
(Properties assumed strong AT STATION 1+'50
enough so as not to affect
analysis results) Channel Bank Stability
Scale: ]
-- Stream O-6/Jones Residence
0 IS-feet Coppell, Texas
Job No. 101-002
Figure 4
Parian, Burke & Thompson
(origins,! si[e deveiopmenO
A: FILL B: CLAY. sandy
r= 120 pcf r= 125 pcf
C= 120 psf C= 200 psf
O= 15° ~= 20°
Critical F.S.= 2.9
BeFore ConsSructio~ (Sro, 1+00)
A: Tension Area B: CLAY, sandy
r: 120 pet r= 125 pet
Critical
1,7
C= 0 pst C-- 300 pst
~= 0° ~= 12° o~lfl,,,~ G,-o,,,,d ...................
B
Channel Area
Dk~rin9 Con$~cruc~cion (S±o, 1+00)
~A: Tension Area B: CLAY, sandy
r= 120 pet r= 125 pet No. (2) failure plane
C= 0 pst C= 200 pst [ _.....~ ~ (1). Critical F.S.= 1.2
~= 0o ~= 18°
(2). Critical F.S.= 1.1
B
C: FILL (wall backfill)
r= 120 pcf
C= 50 pst .
~= 15°
AF~cer Cons±rue±ion (S±o. 1+00)
D: Gabions Wall (3'x3') Bank Area
(Properties assumed strong
enough so as not to affect CROSS SECTION
analysis results) AT STATION ] +00
Scale: I Channel Bank Stability
Stream G-6/Jones Residence
0 15-feet Coppell, Texas
Job No. 101-002
Potion, Burke & Thompson Figure 5
- 0 ,
0 0.3 0.6 0.9 1,2
- Water Content / PI
- - PBT-5 - PBT-6
WATER CONTENT/PI PROFILE
Channel Bank Stability
Strem G-6/Jones Residence
Job No. 101-002 Coppell, Texas
- Patton, Burke & Thompson Figure 6
_ 4 4.2 4.4 4.6 4.8 $ 5.2
Soil Suction (pF)
-- ~- PBT-5 -~- PBT-6
0
c~ -12
- -20 , ~ , ,, ~
5 10 15 20 25 30
Water Content (%)
-~- PBT-5 -~ PBT-6
RESULTS OF SUCTION TEST
Channel Bank Stability
Strem G-6/Jones Residence
Job No. 101-002 Coppell, Texas
-- Patton, Burke & Thompson Figure 7
APPENDICES
APPENDIX A
_ Log of Borings
LOG OF BORING NO. PBT-1
CLIENT: City of Coppell LOCATION: Stream G-61Jones Residence
JOB NAME: Channel Bank Stability RIG TYPE: Portable Rig
DRILLING CONTRACTOR: Core Test LOGGED BY: JWBICHT
SURFACE CONDITIONS: Concrete Slab DATE DRILLED: 11110/95
GROUND ELEVATION: 472.4' JOB NO.: 101-002 PAGE 1 OF 1
-- FIELD DATA LABORATORY DATA DRILLING METHOD(S): Continuous shelby tube sampling
~ ~ GROUNDWATER INFORMATION: Dry at the time of drilling
z
(5 ~ ~O ~- - o SAMPLE TYPE
-- ~ ,,,Z Z_ w _~ ~ ~ E. ~ ~ ~ --~ 0 0 Z "' ST Shelby Tube RC Rock Core SS Sp§t Spoon
m m l- a. ~ ~ o I- I- CT Cuttings TC THD Cone CS California Spoon
.~ [ O~ GEOTECHNICAL DESCRIPTION
-- '- 2~'*~5 CONCRETE (5') pool deck
S1 0.5-1.0 ST P= 1.25 15 ' · FILL, clay, sandy, silty, medium stiff to very stiff, moist,
'N=4/4 * ·
· darkbrown, darkgray
-- -pocket of loose fine sand (brownish yellow), traces of
S2 1.0-2.0 ST P=2.5 20 71
· gravels and roots noted at 1'
-- S3 2.0-3.0 ST P=2.0 21 104 41 19 22 63
S4 3.0-4.0 :ST P=1.2 21 103
S5 4.O-5.O ST P=1.75 23 · ·
~ 5 · · -sandy, dark brown
S6 5.0-6,0 ST P=2.3 14 119 42 20 22 31
·, · -traces of gravels, sands and roots
87 6.0-7.0 ST P=3.25 13 113 "' ·
~ CLAY, sandy, silty, with gravels, traces of roots, very stiff,
-- S8 7.0-8.0 ST P=4.5 14 117 35 21 14 40 ~ moist, brown, brownish yellow (CL, CH)
S9 8.0-9.0 ST P=4.5 12 124
,- _ 10-S10 9.0-10.0 ST P=3.0 10 125
Sll 10.0-11.0 ST P=3.0 13 122
812 11.0-12.0 ST P=2.75 18 115 52 21 31 62
Boring terminated at a depth of 12'
~ N - STANDARD PENETRATION TEST RESISTANCE REMARKS: Boring backfilled with cuttings and concrete
FIELD T - THD CONE PENETRATION RESISTANCE
P o POCKET PENETRATION RESISTANCE patched. *N: blow/increment using portable cone
TEST R - PERCENTAGE OF ROCK CORE RECOVERY penetrometer.
RQD - ROCK QUALITY DESIGNATION
- Patton, Burke & Thompson Figure- A1
LOG OF BORING NO. PBT-2
CLIENT: City of Coppell LOCATION: Stream G-6/Jones Residence
JOB NAME: Channel Bank Stability RIG TYPE: Portable Rig
DRILLING CONTRACTOR: Core Test LOGGED BY: JVVB/CHT
SURFACE CONDITIONS: Concrete Slab DATE DRILLED: 11/10/95
GROUND ELEVATION: 472.5' JOB NO.: 101-002 PAGE 1 OF 1
FIELD DATA LABORATORY DATA DRILLING METHOD(S): Continuous shelby tube sampling
~ ~ GROUNDWATER INFORMATION: Dry at the time of drilling
z_ w ~: ~: ~ ,,z, u ~ z =: ST Shelby Tube RC Rock Core SS Split Spoon
~ ~. ~ ~. o O z ~: ~- ~ ¢~ = ; F ~ e CT Cutting, TC THD Cone CS California Spoon
~ c~ ~ z~-~'c~= c= _~ ~ o. ~ ~ GEOTECHNICAL DESCRIPTION
~ ~ CONCRETE (4.5") pool deck
S1 0.5-1.0 ST 'N =4/4 16 *.*~ FILL, clay, sandy, silty, stiff to very stiff, moist, dark brown,
' N = 4/3 · dark gray
· -pocket of loose fine sand (brownish yellow), traces of
S2 1.0-2.0 ST P= 4.0 17 ··, gravels and roots noted at 1'
e
S3 2.0-3.0 ST P=2.2 20 108 ·
e
S4 3.0-4.0 ST P=1.5 24 35 18 17 72
· -gravelly at 4 to
S5 4.0-5.0 ST P=4.5+ 6 16 ·
5 - ~//'//~.CLAY, sandy, silty, with gravels, traces of roots, stiff to
S6 5.0-6.0 ST P= 2.75 24~ very stiff, moist, brown, greenish gray, brownish yellow
(CL, CH)
S7 6.0-7.0 ST P= 2.25 29 92 -slightly silty, traces of gypsum, brown, greenish gray
S8 7.0-8.0 ST P=2.75 30 90
S9 8.0-9.0 ST P=2.3 28 82 31 51 89
////'~ -traces of limestone nodules
S10 9.0-10.0 ST P=2.25 29 92
_ 10-S11 10.0_11.0 ST P=3.3 29 94
~ -silty, brown
S12 11.0-12.0 ST P=4.5 29 96 83 30 53 92
Boring terminated at a depth of 12'
N - STANDARD PENETRATION TEST RESISTANCE REMARKS: Boring backfilled with cuttings and concrete
FIELD T - THD CONE PENETRATION RESISTANCE
P - POCKET PENETRATION RESISTANCE patched, aN: blow/increment using portable cone
TEST R - PERCENTAGE OF ROCK CORE RECOVERY penetrometer.
RQD - ROCK QUALITY DESIGNATION
Patton, Burke & Thompson Figure- A2
LOG OF BORING NO. PBT-3
CLIENT: City of Coppell LOCATION: Stream G-6/Jones Residence
JOB NAME: Channel Bank Stability RIG TYPE: Portable Rig
DRILLING CONTRACTOR: Core Test LOGGED BY: JWB/CHT
SURFACE CONDITIONS: sloping/wet DATE DRILLED: 11/10/95
GROUND ELEVATION: 467.2' JOB NO.: 101-002 PAGE 1 OF 1
FIELD DATA LABORATORY DATA DRILLING METHOD(S): Continuous shelby tube sampling
~ ~ GROUNDWATER INFORMATION: 9.5' at the time of drilling
,.k- ~ ~ ~ _~ and water at 6.0' (cave at 7'), 2 hours after
completion.
O k- ~ o k: - ~ SAMPLE TYPE
,¥ z ~ ~=. ~w..=.e~ ~ e) z u ~ z~ -~ o= O~ zc~ =o ST Shelby Tube RC Rock Cot. SS Split Spoon
-J J O u~ ~: u~ _ ~ k- ~ ~ CT Cuttirlgs TC THD Cone CS California Spoon
~ ~ ~ ~ Z~-=== c~ _~ = = . GEOTECHNICAL DESCRIPTION
· FILL, clay, sandy to sand, traces of gravels, soft to very
Sl 0.0-1.0 ST P=O.8 21 stiff, moist to very moist, dare brown, brown
S2 1.0-2.0 ST P=0.7 18 39
S3 2.0-3.0 ST P=2.0 18 107 ·
S4 3.0-4.0 ST P= 2.0 15 112 ·
85 4.0-5.0 ST P=3.5 17 112 33 16 17 48
-gravelly at 5'
S6 5.0-6.0 ST P=3.3 14 ·
~ CLAY, sandy, stiff to very stiff, moist to very moist,
brownish yellow (CL, CH)
S7 6.0-7.0 ST P=2.3 14 120
S8 7.O-8.0 ST P=2.25 15
S9 8.0-9.0 ST P=1.5 15 120 33 15 18 38
-traces of gravels
Sl(~ ~9.0-10.0 ST P=3.0 19
- 10 Boring terminated at a depth of 10'
N - STANDARD PENETRATION TEST RESISTANCE REMARKS: Boring backfilled with cuttings
FIELD T - THD CONE PENETRATION RESISTANCE
P - POCKET PENETRATION RESISTANCE
TEST R - PERCENTAGE OF ROCK CORE RECOVERY
RQD - ROCK QUALITY DESIGNATION
Patton, Burke & Thompson Figure- A3
LOG OF BORING NO. PBT-4
CLIENT: City of Coppell LOCATION: Stream G-6/Jones Residence
JOB NAME: Channel Bank Stability RIG TYPE: Portable Rig
DRILLING CONTRACTOR: Core Test LOGGED BY: JWB/CHT
SURFACE CONDITIONS: Grass/sloping DATE DRILLED: 11110/95
GROUND ELEVATION: 470.3' JOB NO.: 101-002 PAGE 1 OF 1
-- FIELD DATA LABORATORY DATA DRILLING METHOD{S): Continuous shelby tube sampling
~ ~ GROUNDWATER INFORMATION: Dry at the time of drilling
_z ~; ~: ~ ~ ,m ~ ~ '~ o ~ z cz: ST Shelby Tube RC Rock Core SS Split Spoon
c~ ,, ~ ~ 2 ~' I- 3: c~ ,,, e. u{, ~ .~u,,,.. ~ ~3 a. (n e cai- ~. ~ O, z ........ O I- z_ ~- n- c¢ ~' o:~ C3 ~~¢1 ¢3 '~ I- a. I- =. ~ eO ..~ - CT CuttingsGEOTECHNiCAL TC THD Cone DESCRIPTION cs california Spoon
~ * FILL, clay, sandy, with gravels and roots, very stiff, moist,
Sl 0.0-1.0 ST P=4.5+ 17 ** dark brown
· N = 4~6~5 *
CLAY (fill-?), sandy, slightly silty, with gravels, traces of
roots, very stiff, moist, brownish yellow, greenish gray,
~S2 1.0-2.0 ST P=4.5+ 15 brown (CL, CH)
-pocket of cemented sand, clayey, dark brown noted at
-- S3 2.0-3.0 ST P=4.5+ 13 116 31 13 18 32
S4 3.0-4.0 ST P=4.5+ 12 -brownish yellow
S5 4.0-5.0 ST P=4.5+ 20
S6 5.0-6.0 ST P=4.5+ 15 111 48 20 28 44 -roots notes at 5.2
S7 6.O-7.0 ST P=4.5+ 11
-- S8 7.0-8.0 ST P=4.5+ 7
S9 8.O-9.0 ST P = 4.5 + 11
Sl0 9.0-10.0 ST P=2.75 13 125 36
Sll 10.0-11.0 ST P=3.25 13
S12 11.0-12.0 ST P=4.0 13 121
Boring terminated at a depth of 12'
~ N - STANDARD PENETRATION TEST RESISTANCE REMARKS: Boring backfilled with cuttings.
FIELD T - THD CONE PENETRATION RESISTANCE *N: blow/~ncrement using portable cone penetrometer.
P - POCKET PENETRATION RESISTANCE
TEST R. PERCENTAGE OF ROCK CORE RECOVERY
RQD - ROCK QUALITY DESIGNATION
-- Patton, Burke & Thompson Figure-A4
LOG OF BORING NO. PBT-5
CLIENT: City of Coppell LOCATION: Stream G-61Jones Residence
JOB NAME: Channel Bank Stability RIG TYPE: Portable Rig
DRILLING CONTRACTOR: Core Test LOGGED BY: JVVB/CHT
SURFACE CONDITIONS: Grass/flat DATE DRILLED: 11/10/95
GROUND ELEVATION: 478'-480' JOB NO.: 101-002 PAGE 1 OF 1
-- FIELD DATA LABORATORY DATA DRILLING METHOD(S): Continuous shelby tube sampling
;~ ' GROUNDWATER INFORMATION: Dry at the time of drilling
(5 " ~ O ~- - ~ SAMPLE TYPE
=' z - 0 z ~¢ ST Shelby Tube RC Rock Core SS spr~ Spoon
· _ TC THD Cone CS cardornia Spoon
~ GEOTECHNICAL DESCRIPTION
-- · FILL, clay, sandy, with gravels, sands and roots, stiff,
Sl 0.0-1.0 ST P=2.1 15 ' · moist, dark brown
"N=2/3 *
~ CLAY (fill-?), sandy, slightly silty, with gravels, traces
of
-- S2 1.0-2.0 ST P=2.25 18 48 18 30 60 roots, stiff to very stiff, moist, brownish yellow, greenish
gray, brown iCL, CH)
-- S3 2,0-3,0 ST P=3.0 18 104
S4 3.0-4.0 ST P=4.5+ 17
S5 ~' 4.0-5.0 ST P=4.5+ 7 119 29 15 14 28
-- 5 - -gravelly noted at 4 to 7'
S6 5.0-6.0 ST P=4.5+ 7 ~ i
S7 6.0-7.0 ST P=4.5+ 9
~ -traces of gypsum
-- S8 7.0-8.0 ST P=4.5+ 19
S9 8.0-9.0 ST P=4.5+ 20
-gravelly and roots noted at 9'
Sl0 9.0-10.0 ST P=4.5+ 25
-- ~- 10 - -slightly silty, greenish gray, brownish yellow
Sll 10.0-11.0 ST P=4.5+ 25 95
S12 11.0-12.0 ST P=4.0 28
Boring terminated at a depth of 12'
-- N - STANDARD PENETRATION TEST RESISTANCE REMARKS: Boring backfilled with cuttings.
FIELD T - THD CONE PENETRATION RESISTANCE *N: blow/increment using portable cone penetrometer.
P - POCKET PENETRATION RESISTANCE
TEST R - PERCENTAGE OF ROCK CORE RECOVERY
RQD - ROCK QUALITY DESIGNATION
-- Patton, Burke & Thompson Figure- A5
LOG OF BORING NO. PBT-6
CLIENT: City of Coppell LOCATION: Stream G-6/Jones Residence
JOB NAME: Channel Bank Stability RIG TYPE: Portable Rig
DRILLING CONTRACTOR: Core Test LOGGED BY: JWBICHT
SURFACE CONDITIONS: Grass/flat DATE DRILLED: 11/10/95
GROUND ELEVATION: 478'-480' JOB NO.: 101-002 PAGE 1 OF 1
-- FIELD DATA LABORATORY DATA DRILLING METHOD(S).' Continuous shelby tube sampling
~ ~ GROUNDWATER INFORMATION: Dry at the time of drilling
>-
v
=: ~. ~.~.u. z ~ ~: ~ - o SAMPLE TYPE
d ,. ~o,.--~ - - ~ d
~ z ~ ~ ~: ~: ~ ~ ~ ~ ,,Z, '~ c.;, O Z O= ST Shelby Tube RC Rock Core SS Split Spoon
o. ~ 0 ~ ~ CT Cuttings TC THO Cone CS California Spoon
o o~ 0 ~ ........ 0 Z --
- ~ GEOTECHNICAL DESCRIPTION
-- - . *. FILL, clay, sandy, with gravels, sands and roots, very stiff,
S1 0.0-1.0 ST P= 4.5 + 1 6* moist, dark brown
'N =2/2
CLAY (fill-?), sandy, slightly silty, with gravels, traces of
roots, very stiff, moist, brownish yellow, greenish gray,
S2 1.0-2.0 ST P = 4.5 + 8 1 1 3 brown (gL, CH)
-gravelly noted at 1' to 3'
-- S3 2.0-3.0 ST P=4.5+ 11 45 19 26 53
S4 3.0-4.0 ST P=4.5+ 8
S5 4.0-5.0 ST P=4.5+ 12
-- 5 - -roots noted at 4.5'
S6 5.0-6.0 ST P=4.5+ 11
S7 6.0-7.0 ST P=4.2 13
-- S8 7.0-8.0 ST P=3.5 13
-gravelly at 8' to 9'
S9 8,0-9.0 ST P = 4.5 15
-traces of gypsum and roots
,S10 9.0-10,0 ST P=4.3 25
-- 10 Boring terminated at a depth of 10'
-- N - STANDARD PENETRATION TEST RESISTANCE REMARKS: Boring backfilled with cuttings.
FIELD T - THD CONE PENETRATION RESISTANCE *N: blow/increment using portable cone penetrometer.
P - POCKET PENETRATION RESISTANCE
TEST R - PERCENTAGE OF ROCK CORE RECOVERY
RQD - ROCK QUALITY DESIGNATION
-- Patton, Burke & Thompson Figure- A6
UNIFIED SOIL CLASSIFICATION SYSTEM
I SYMBOLS TYPICAL
MAJOR DIVISIONS / GRAPH I LETTER DESCRIPTIONS
o 0 o 0 o 0 o ... WELL-GRADED GRAVELS, GRAVEL-
GRAVEL o [::::> c:~ (,.~W SAND MIXTURES, LITTLE OR NO
-- AND CLEAN lC). C~ _ C)l°° Oo oo C)!°J FINES
GRAVELLY GRAVELS
. I. I. I. ..... POORLY-GRADED GRAVELS, GRAVEL
COARSE SOILS ~.~o ~, ~,~ ~ 'FINEsSAND MIXTURES, LITTLE OR NO
MORE THAN 50% GMMIXTURES
OF COARSE
FRACTION GRAVELS
-- RETAINED ON NO. WITH FINES CLAYEY GRAVELS, GRAVEL - SAND -
4 SIEVE GC CLAY MIXTURES
-- MORE THAN 50% SAND SW SANDS, LITTLE OR NO FINES
OF MATERIAL IS AND -,-,.,,,,,,,,,,,,,
LARGER THAN NO.
200 S[EV£ SiZE SANDY CLEAN SANDS
POORLY-GRADED SANDS, GRAVELLY
-- SOILS ~!:i~ SP SAND. LITTLE OR NO FINES
MORE THAN 50%
__ OF COARSE-i .' _____
FRACTION
INORGANIC SILTS AND VERY FINE SANDS,
M L .ocK FLOUR, SILTY OR
SANDS
OR CLA~Y SILTS WITH SLIGHT PLASTICITY
GRAINED AND LESS THANt~ GL PLASTICITY. GRAVELLY CLAYS, SANDY
SOILS CLAYS 5O C~AYS, SILTY CLAYS, LEAN CLAYS
ORGANIC SILTS AND ORGANIC SILTY
-- OL CLAYS OF LOW PLASTICITY
MORE THAN 50% MH DIATOMACEOUS FINE SAND OR
-- OF MATERIAL IS SILTY SOILS
SMALLER THAN
NO. 200 SIEVE SILTS AND LIQUID LIMIT ~f~'JJ~'f~ INORGANIC CLAYS OF HIGH
S~ZE CLAYS GREATER THAN~ CH PLASTICITY
_ 50
~-~z~.~...-.~?.~.~.~ OH H,GH ~LAST,C,TY. OR~AN,C S,LTS
-- PEAT, HUMUS, SWAMP SOILS WITH
HIGHLY ORGANIC SOILS PT HIGH ORGANIC CONTENTS
__ ASPHALT
FILL
LIMESTONE
I I I I I
SHALE
SANDSTONE
~ " CONCRETE
[ ~ ','x '~x '~ '~l
CHALK
-- Patton, Burke & Thompson Figure- A7
APPENDIX B
- Laboratory Test Results
SUMMARY OF LABORATORY TEST RESULTS
Client: The City of C0ppell
Project Name: Channel Bank Stability (Stream G-6/Jones Residence)
Location: Coppell, Texas Date: 10/17/95
Boring Depth Soil Description Moisture Dry Unit Swell Test Data Suction Atterberg Limits Minus #200
Number (ft) Content (%) Weight (pcf) Swell (%) Pressure (ipso (pF) LL PI Sieve 200 (%)
PBT-1 0.5-1 FILL, clay, sandy 15
1-2 FILL, clay, silty 20 71
2-3 FILL, clay, si~ty 21 104 41 22 63
3-4 FILL, clay, silty 21 103
4-5 FILL, clay, silty 23
5-6 FILL, clay, sandy 14 119 42 22 31
6-7 FILL, clay, sandy 13 113
7-8 CLAY, sandy, with ~lravels 14 117 35 14 40
8-9 CLAY, sandy, with ~lravels 12 124
9-10 cLAY, sandy, with ~lravels 10 125
10-11 CLAY, sandy, with gravels 13 122
11-12 CLAY, sandy, with ~lravels 18 115 52 31 62
PBT-2 0.5-1 FILL, clay, sandy 16
1-2 FILL, clay, sandy 17
2-3 FILL, c~ay, si~7 20 108
3-4 FILL, clay, sandy 24 35 17 72
4-5 FILL,clay, sandy, ~lmvelly 6 16
5-6 !CLAY, sandy, with gravels 24
6-7 cLAY, sandy 29 92
7-8 CLAY, sandy, with ~lravels 30 90
Patton, Burke & Thompson Job No. 101-002 Figure B1
SUMMARY OF LABORATORY TEST RESULTS
Client: The City of Coppell
Project Name: Channel Bank Stability (Stream G-6/Jones Residence)
Location: Coppell, Texas Date: 10/17/95
Boring Depth Soil Description Moisture Dry Unit Swell Test Data Suction Atterber~ Limits Minus #200
Number (ft) Content (%) Weicjht (pcf) Swell (%) Pressure (psf) (pF) LL PI Sieve 200 (%)
PBT-2 8-9 CLAY, sandy, sli~lhtly silty 28 82 51 89
9-10 CLAY. sandy, slightly silty 29 921
10-11 CLAY, sandy, sli~lhtly silty 29 94
11-12 CLAY, sandy, silty 29i 96 83 53 92
PBT-3 0-1 FILL, clay, sandy to clayey sand 21
1-2 FILL, clay, sandy to clayey sand 18 39
2-3 FILL, clay, sandy to clayey sand 18 107
3-4 FILL, clay, sandy to clayey sand 15 112
4-5 FILL, clay, sandy, ~lravelly 17 112 33 17 48
5-6 FILL, clay, sandy 14
6-7 CLAY, sandy 14 120
7-8 CLAY, sandy 15
8-9 cLAY, sandy 15 120 33 18 38
9-10 CLAY, sandy, with gravels 19
PBT-4 0-1 FILL, clay, sandy 17
1-2 CLAY Ifill-?/, sandy, with ~lravels 15
2-3 CLAY (fill-?I, sandy, with ~lravels 13 116 31 18 32
3-4 CLAY (fill-?), sandy, with gravels 12
4-5 CLAY (fill-?), sandy, with gravels 20
Patton, Burke & Thompson Job No, 101-002 Figure B2
SUMMARY OF LABORATORY TEST RESULTS
Client: The City of Coppell
Project Name: Channel Bank Stability (Stream G-6/Jones Residence)
Location: Coppell, Texas Date: 10/17/95
Boring Depth Soil Description Moisture Dry Unit Swell Test Data Suction Atterber~l Limits Minus #200
Number (ft) Content (%) Weight (pcf) Swell (%) Pressure (pst') (pF) LL PI Sieve 200 (%)
PBT-4 5-6 CLAY (fill-?), sandy 15 111 48 28 44
6-7 CLAY (fill-?), sandy, with gravels 11
7-8 CLAY (fill-?I, sandy, with gravels 7
8-9 CLAY (fill-?), sandy, with ~]ravels 11
9-10 CLAY (fill-?), sandy, with ~ravels 13 125 36
10-1 1 CLAY (fill-?), sandy, with ~ravels 13
11-12 CLAY (fill-?), sandy, with ~ravels 13 121
PBT-5 0-1 FILL, clay, sandy 15
1-2 CLAY (fill-?I, sandy, with ~]ravels 18 48 30 60
2-3 CLAY (fill-?), sandy, with ~ravels 18 104 0.1 600 4.2522
3-4 CLAY (fill-?), sandy, with ~ravels 17
4-5 CLAY (fill-?), sand)/, ~ravell¥ 7 119 29 14 28
5-6 CLAY (fill-?I, sandy, gravelly 7
6-7 cLAY (fill-?I, sandy, ~lravelly 9 4.3838
7-8 cLAY (fill-?), sandy 19
8-9 CLAY (fill-?), sandy, ~lravelly 20 4.3103
9-10 CLAY (fill-?), sandy 25 ...
10-11 cLAY (fill-?), sandy 25 95 i 0,1 12001 4,2324
11-12 cLAY (fill-?), sandy, sli(,Ihtly silty 28
Patton, Burke & Thompson Job No. 101-002 Figure B3
SUMMARY OF LABORATORY TEST RESULTS
Client: The City of Coppell
Project Name: Channel Bank Stability (Stream G-6/Jones Residence)
Location: Coppell, Texas Date: 10/17/95
Boring Depth Soil Description Moisture Dry Unit Swell Test Data Suction Atterber~l Limits Minus #200
Number (fl) Content (%) Weight (pcf) Swell (%) Pressure (psf) (pF) LL PI Sieve 200 (%)
PBT-6 0-1 FILL, c~¥, sandy 16
1-2 CLAY (fill-?), sandy, gravelly 8 113
2-3 CLAY (fill-?), sandy, 9ravell¥ 11 5.0031 45 26 53
3-4 CLAY (fill-?), sandy, with ~lravels 8
4-5 CLAY (fill-?), sandy, with grovels 12 4.7583
5-6 CLAY Ifill-?), sandy 11
6-7 cLAY {ffil-?), sandy 13
7-8 cLAY {fill-?), sandy 13
8-9 CLAY {fill-?), sandy, gravelly 15 4.5460
9-10 CLAY {fill-?}, sandy 25
Patton, Burke & Thompson Job No. 101-002 Figure B4
Boring Depth Material Moisture Dry Unit Confining Max. Deviator
No_..=. (ft) Type Content (%) Weklht (Dcf} Pressure (pst} stress (psf)
PBT-1 3-4 FILL, clay, silty 22 102 500 2840
-- PBT-2 7-8 CLAY, sandy, 27 95 1000 2650
with gravels
PBT-3 3-4 FILL, clay, sandy 17 110 500 2020
to clayey sand
TRIAXlAL COMPRESSION TEST
Test Type: ASTM D 2850- UU SUMMARY OF RESULTS
Channel Bank Stability
Stream G-6/Jones Residence
Job No. 101-002 Coppell, Texas
- Patton, Burke & Thompson Figure B5
3.00
2.50 .
2.00
1.50
1.00
0 O0 '
0.0 0.5 1.0 1 .$ 2.0
Normal Stress (ksf)
Boring No.: PBT-1 Depth (ft): 7-8
Soil: Clay, sandy
Average water content (%): 12
Average dry unit weight (pct'): 114
Angl~ of Friction (degree'l: 38
Cohesion (pst'): 800 DIRECT SHEAR TEST
Test Type: ASTM D 3080 Channel Bank Stability
Stream G-6/Jones Residence
Job No. 101-002 Coppell, Texas
Patton, Burke & Thompson Figure B6
GRAIN SIZE (mm)
100 10 0 1 0 01 0 001
?o .
n,' 30 -
Z 2o ...................................................................................
U.S. STANDARD SIEVES
~ PBT-2, 4-5'
GRAIN SIZE DISTRIBUTION ANALYSIS
Channel Bank Stability
Stream G-6/Jones Residence
Job No. 101-002 Coppell, Texas
Patton, Burke & Thompson Figure B7
_..- . .................... ~....u....u..:_..:_u..: ......... ............... ~ ......~. _,.~.~ ~ ....... i~~ i~ 1-.~-~:i-[ ......... .'-----i...:..~.g.i-. . .
4 00 : ~ '
I 10 100 1000 10000
- Pressure (psf)
_ Boring No. ' B-5 Depth (ft): 2-3
Soil: CLAY (fill-?), sandy
Water content (%): 18
Dh/unit weight (pcf): 104 SWELL TEST
Swell I%1: 0.~ Channel Bank Stability
Stream G-6/Jones Residence
_ Job No. 101-002 Coppell, Texas
Patton, Burke & Thompson Figure B8
Boring No, ' B-5 Depth (fi): 10-11
Soil: CLAY (fill-?), sandy
Water content (%): 27
Dry unit weight (pcf): 95 SWELL TEST
Swell (%): 0.1 Channel Bank Stability
Stream G-6/Jones Residence
_ Job No, 101-002 Coppell, Texas
Patton, Burke & Thompson Figure B9
APPENDIX C
Selected Study Photographs
Taken On
November 10, 1995
-- PHOTO 1, Looking northward along west bank of stream G-6 (remains of old wooden wall
around station 10+00)
- PHOTOGRAPHS
_ Channel Bank Stability
Stream G-6/Jones Residence
Job No. 101-002 coppell, Texas
-- Patton, Burke & Thompson Figure Cl
A. South end
.... B. North end
PHOTO 2. Looking westward at disturbed bank area
-- PHOTOGRAPHS
Channel Bank Stability
Stream G-6/Jones Residence
lob No. 101-002 Coppell, Texas
-- Patton, Burke & Thompson Figure C2
PHOTO 3. Looking southward along G-6 channel (from around station 11+00)
-- PHOTO 4. Looking southward along west bank slope (from around station 10+25)
- PHOTOGRAPHS
Channel Bank Stability
Stream G-6/Jones Residence
No. 101-002 Coppell, Texas
-- Figure C3
Patton, Burke & Thompson
- ~HOTO 5. Looking southward along east side of pool (man patching hole in concrete
for Boring PBT-2)
- PHOTOGRAPHS
Channel Bank Stability
Stream G-6/Jones Residence
Job No. 101-002 i Coppell, Texas
-- Patton, Burke & Thompson Figure C4
-- PHOTO 6. Looking northward along east side of home (large mature tree approximately
10-feet from fireplace in master bedroom)
PHOTOGRAPHS
Channel Bank Stability
Stream G-6/Jones Residence
Job No. 101-002 Coppell, Texas
Patton, Burke & Thompson Figure C5
PHOTO 7. Looking northward along west side of home (large mature tree approximately
4-feet from bathroom to bedrooms 2 and 3)
PHOTOGRAPHS
-- Channel Bank Stability
Stream G-6/Jones Residence
Job No. 101-002 Coppell, Texas
Patton, Burke & Thompson Figure C6