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GEOTECHNICAL ENGINEERING REPORT PROPOSED GABION BASKET RETENTION WALLS & RIP/RAP BIG FOSSIL CREEK @ GLENVIEW AND BROADWAY ROADS
HALTOM CITY, TEXAS
Prepared for: CITY OF HALTOM CITY
EWL Report No. HC081718 May 2008
eotechnical Studies Group, Inc. ~ Ellerbee Walczak Lawrence May 28,2008 A DMsion of BIert>ee/Walczak. Inc.
City of Haltom City PO Box 14246 Haltom City, Texas 76117
Attn Mr. Lenny Williams
Re Geotechnical Engineering Report Proposed Gabion Basket Retention Wall & Rip-Rap Bid Fossil Creek at Glenview and Broadway Roads Haltom City, Texas EWL Report No. HC081718
Gentlemen:
Ellerbee-Walczak-Lawrence, Inc. (EWL), a division of EWI, has completed its Preliminary Geotechnical Engineering Report at the above referenced location. The results are presented in the attached report
Please do not hesitate to contact us if you have any questions regarding the information in this report or if we can be of any additional assistance
It has been a pleasure providing geotechnical services for this project.
c-4 c I v
Brent Doug s, Principal i........-.
Copies Submitted (3)
4501 Broadway Ave. • P.O. Box 14809 • Haltom City. Texas 76117 Office 817-759-9999 • Fax 817-759-1888
TABLE OF CONTENTS
Page
1.0 SITE AND PROJECT INFORMATION 1
2.0 SCOPE OF SERViCES 1
3.0 FIELD OPERATIOI\JS 1
4.0 LABORATORY TESTING 2
5.0 SITE SUBSURFACE CONDITIONS 2
6.0 GROUNDWATER 3
7.0 ANALYSIS AND RECOMMENDATIONS 3 7.1 Foundation System 3
7.1.1 Straight Drilled Shafts 3 7.1.2 Lateral Capacity 4 7.1.3 Soil Induced Uplift Loads 4 7.1.4 Drilled Shaft Construction Considerations 4
7.2 Gabion Basket Walls 5 7.3 Earthwork/Site Grading 6 7.4 Global Slope Stability 7 7.5 Permanent Slopes 8
8.0 LIMITATIONS 8
APPENDIX A Figure
Plan of Borings 1 Boring Logs 2 - 4 Key to Symbols used on Boring Logs 5
APPENDIX B Figure
Slope Stability Analysis 1 - 6
GEOTECHNICAL ENGINEERING REPORT PROPOSED GABION BASKET RETENTION WALLS & RIP/RAP BIG FOSSIL CREEK @ GLENVIEW AND BROADWAY ROADS
HALTOM CITY, TEXAS
1.0 SITE & PROJECT INFORMATION
The project sites are located near the Broadway and Glenview bridges crossing Big Fossil creek
in the City of Haltom City, Tarrant County, Texas. The creek bank near Glenview was heavily
forested with the exception of the utility easement. The Broadway location was generally more open and contained trees near the creek banks. We understand significant creek erosion has
occurred in the past.
Planned construction consists of a gabion basket wall for major erosion protection and slope
improvements with rip/rap in the less eroded areas. The slopes will extend to heights of
approximately 17 feet, or less at the Broadway location and approximately 15 feet, or less, at the Glenview location.
2.0 SCOPE OF SERVICES
The purpose of our geotechnical services for this site were to:
• Evaluate the subsurface conditions encountered in the borings.
• Evaluate the pertinent engineering properties of the recovered samples.
• Provide recommendations for gabion basket wall foundations, earthwork and site grading.
• Global slope stability studies on three cross-sections.
3.0 FIELD OPERATIONS
The subsurface conditions of the site were evaluated by performing three borings which were
drilled on April 25, 2008 at accessible open locations clear of utilities. The approximate boring
locations are provided on the Site Plan (Figure 1) in the Appendix. The results of the field
exploration program are presented on the Logs of Boring (Figures 2 through 4) in the Appendix. A key to symbols used on the boring logs is presented on Figure 5.
A truck-mounted drilling rig with continuous flight augers was used to advance the borings. Soils were sampled using steel tubes and during performance of standard penetration tests. The samples were extruded in the field, logged, sealed, and packaged to preserve their in-situ moisture content and reduce disturbance during transportation to the laboratory. The load carrying capacity of the gray shale encountered in the borings was evaluated in the field by performance of the Texas Department of Transportation's (TxDOT) Cone Penetration Test.
EMIL -1- HC081718
Dnlling and sampling were performed in general accordance with applicable ASTM and TxDOT
procedures.
4.0 LABORATORY TESTING
The Boring Logs and samples were reviewed by a geotechnical engineer who assigned soil
samples for testing. Tests were performed in the laboratory by technicians working under the direction of the engineer. Testing was performed in general accordance with applicable ASTM
procedures.
Liquid and Plastic Limit tests were performed on samples of the cohesive soils. These tests were
used in conjunction with moisture content tests for classification and estimating their volume
change potential. Unconfined compression test were performed on samples of cohesive soils to evaluate strength and hand penetrometer tests were performed to evaluate consistency.
The results of the laboratory tests are presented on the Boring Logs and in the Appendix.
5.0 SITE SUBSURFACE CONDITIONS
The conditions encountered at each boring location are depicted on Boring Logs in the Appendix.
Descriptions of each stratum with its approximated depth and thickness are provided. The depths reported on each log refer to the depth from the existing ground surface at the time the borings were performed.
Fill materials consisting of brown and tan silty clays with gravel and concrete were encountered at
the surface of Borings 1 and 2, and extended to depths of about 4 and 1 feet below existing
grades. Samples of the fill soils had Liquid Limits (LL) of 42 percent and Plasticity Indices (PI) of
27 and 28. The fill soils classified as CL according to the Unified Soil Classification System (USCS) and very stiff to hard in consistency.
Dark brown, brown, tan and gray silty clays, some with sand and gravel, were encountered
beneath the fills in Borings 1 and 2 and encountered at the surface of Boring 3. They extended to depths of about 21 Yz, 17 and 15 feet below existing grades in Borings 1, 2 and 3, respectively.
The silty clays had LL's of 39 to 48 percent; PI's of 26 to 32, classified as CL according to the USCS and was very stiff to hard in consistency in the upper portions becoming softer and moister
with depth.
Gray and tan shaley clays, clays and occasional gravelly clays were next encountered in the borings and extended to depth of about 28, 22Yz and 18Yz feet below existing grades in Boring 1, 2 and 3, respectively. They had LL's of 44 and 60 percent, PI's of 31 and 44, classified as CH and CL according to the USCS and were firm to stiff in consistency and generally saturated.
EWL -2- HC081718
Very dense, gray shale with limestone layers was next encountered in the borings at depths of about 18/'2 to 28 feet below existing grades and extended to the termination depths of about 30 to
40 feet below existing grades.
The soils encountered in the borings are considered to be active to highly active with respect to moisture-induced volume changes. Active clay soils will shrink and swell with variations in
seasonal moisture change.
6.0 GROUNDWATER
The borings were advanced in the dry using auger-drilling techniques. This process allows relatively accurate short-term observations of groundwater while drilling. Seepage was observed
in Borings 1, 2 and 3 while drilling at depths of about 23, 17 and 12 feet below existing grades,
respectively. A water level of about 16 feet was measured in the open borehole B-1, prior to
backfilling. Borings 2 and 3 were observed to be dry at dnlling completion.
Groundwater levels will seasonally fluctuate due to variations in the amount of precipitation,
evaporation, surface water runoff and fluctuation in the creek water levels. In addition,
groundwater conditions may change due to landscape irrigation, tree root demand and from leaking buried utilities.
7.0 ANALYSIS AND RECOMMENDATIONS
7.1 Foundation System
Based on the conditions encountered in the borings, a positive foundation system for the
proposed gabion wall base is straight drilled, reinforced concrete shafts founded in the gray shale that was encountered at depths of 28, 22/'2 and 18/'2 feet below existing grades.
Consideration may also be given to placing the bottom gabion baskets on a continuous concrete
footing extending into shale. The footings may be constructed of stacked gabion wall sections. Design parameters are presented below.
7.1.1 Straight Drilled Shafts
Straight drilled shafts penetrating the gray shales will use a combination of end bearing and skin friction in developing their load carrying capacity. We recommend an allowable end bearing pressure of 10,000 pounds per square feet (PSF) and an allowable skin friction value of 1,200
PSF for compressive loads. Allowable skin friction of 500 PSF can be considered on the overlying soils. The upper 5 feet of skin friction in the shaft should be neglected. These values
EMIL -3- HC081718
contain a safety factor of three (3). Higher skin friction values are applicable for that portion of the
shaft embedded in the gray shales below any temporary casing.
The shafts should penetrate the bearing stratum a minimum of 4 feet. Deeper penetrations may
be required to develop additional skin friction and/or uplift resistance. A minimum shaft diameter of 18 inches is recommended.
Adjacent shafts should maintain a minimum center to center spacing of 3.0 times the diameter of
the larger shaft. Closer spacing will require reductions in the skin friction values presented above, and possibly special installation sequences. As a general guide, the design skin friction
will vary linearly from the full value at a spacing of 3.0 diameters to 50 percent of the design value at 1.0 diameter. This firm should be contacted to review, on a case by case basis, shafts
requiring closer spacing.
Settlements for properly installed and constructed straight shafts in competent shales should be less than one-half inch.
7.1.2 Lateral Capacity
An allowable passive resistance of 2,000 PSF is recommended in the gray shale. An allowable
passive resistance of 400 PSF can be considered for the overlying soils. This lateral resistance is considered to act on the projected diameter of the shaft.
7.1.3 Soil Induced Uplift Loads
Since the lower gabion baskets will be resting near saturated soils there will be little uplift as a result of heave in the soils. For the conditions encountered at this site, minimum reinforcing equal to 0.5 percent of the shaft can be considered to resist soil induced uplift loads.
7.1.4 Dri lied Shaft Construction Considerations
Excavations for the shafts should be maintained in the dry. Preferably, concreting should closely
follow excavation to reduce caving and/or seepage problems. Groundwater seepage was observed in the borings and will likely be encountered during installation of some of the straight
shafts, particularly during wet seasonal cycles. Seepage rates may be sufficient to require the use of temporary casing for installation. The casing should be seated in the bearing stratum with
all water and most loose material removed prior to beginning the design penetration. Care must then be taken that a sufficient head of plastic concrete is maintained within the casing during extraction.
EMIL -4- HC081718
The concrete should have a slump of 6 inches plus or minus 1 inch and be placed in a manner to avoid striking the reinforcing steel during placement. Complete installation of individual shafts
should be accomplished in one day's operation and within an 8 hour period after the design penetration is begun. Close coordination of excavation and concreting will be required for
installation of straight shafts.
The drilled shaft design recommendations provided in this report are based on proper construction procedures, including maintaining a dry shaft excavation and proper cleaning of bearing surfaces prior to placing reinforcing steel and concrete. All drilled shaft installations
should be inspected by qualified geotechnical personnel to help verify the bearing stratum, the design penetration, and perform related duties.
7.2 Gabion Basket Walls
Based on the conditions encountered in the borings and the anticipated wall height provided by
Freese & Nichols, the toe of the gravity walls will be situated on shaley clays or silty clays and
may be designed with a maximum allowable bearing pressure of 1,500 PSF. A coefficient of friction of 0.35 is recommended for evaluating sliding resistance.
The retaining walls were analyzed as gravity walls placed on 3'(wide) x 1'(deep) stacked baskets
extending 1 foot into shale as described in the Global Slope Stability section below. They should be checked for bearing pressure, sliding and overturning. Resistance to sliding and overturning
should be checked for each section of wall for the full wall height.
Lateral earth pressures acting on the retaining walls will depend on the type of backfill material
used. Recommended lateral earth pressures expressed as equivalent fluid pressures are presented below for rigid and flexible walls with a level backfill. Rigid walls are not anticipated to deflect sufficiently to mobilize active earth pressures. Tied-back walls should be considered rigid.
Active earth pressures can be used where the top of the wall will deflect on the order of 0.5
percent of the wall height. Gravity walls should be designed for an active earth pressure condition.
EQUIVALENT FLUID PRESSURES
Backfill Material
On-site silty clays soils
Active (Flexible)
(pet)
75
At-Rest (Rigid) (pet)
95
Select Fill, with Liquid Limit less than 35 and PI less than 15
50 65
I
Granular backfill, less than 3% passing No. 200 sieve and less than 30% passing No. 40. Non-plastic
I
35
I
50
EIIIIL -5- HC081718
The wall backfill limits should extend outward at least 2 feet from the base of the wall and then
upward on a 1H:2V slope. For narrower backfill widths of granular or select fill soils, the
equivalent fluid pressures for the on-site soils should be used.
The lateral earth pressure values do not include surcharge loads due to overburden, foundation
influences, equipment, etc. Surcharge loads should be considered if they apply at the surface
above the wall within areas defined by an angle of 45 degrees from the base of the wall. A lateral pressure coefficient of 0.5 is recommended for uniformly distributed surcharge loads.
Wall backfill materials should be placed in loose lifts, less than 9 inches thick, and uniformly
compacted to a minimum density of 95 percent of ASTM 0698. Moisture content during placement of cohesive backfill should be within 0 to +5 percent of the optimum moisture content
as measured in test method ASTM 0698. Granular backfill should not be water jetted to achieve compaction and should be placed at a moisture content to allow the desired density to be achieved,
The top of the granular backfill should be protected by flatwork or a minimum of 2 feet of more clayey soils to help prevent surface infiltration.
The design recommendations presented above assume hydrostatic pressures will not develop
behind the wall. Drainage could be provided by the gabion design itself or by using a collector pipe or weep holes near the base of the wall. Gabion baskets, drains or weep holes should be properly filtered to minimize the potential for erosion through these drains and/or plugging of drain lines,
Settlement of the wall backfill should be anticipated. Piping and conduits through the fill should
be designed for potential soil loading due to fill settlement. Flatwork and sidewalks over the fills
may also settle. Backfill compacted to the density recommended above is anticipated to settle on the order of one half to one percent of the fill thickness.
7.3 Earthwork/Site Grading
The onsite soils are suitable for use in site grading. Imported fill material should be clean soil with
a Liquid Limit preferably less than 35 percent and no rock greater than 4 inches in maximum dimension. The fill materials should be free of vegetation and debris.
Prior to placing any fill, the areas to receive fill will need to be stripped and grubbed. Any soft or
pumping areas should be excavated to firm ground and properly backfilled as described below. Prior to placing any fills, the subgrade should be scarified to a minimum depth of 8 inches and recompacted to a minimum of 95 percent of ASTM D 698 at or above the optimum moisture content as determined by that test. The fill materials should then be spread in loose lifts, less
than 9 inches thick, and uniformly compacted to the same criteria. If filling is suspended and the
EMIL -6- HC081718
subgrade becomes desiccated or rutted, it should be reworked prior to placement of a
subsequent lift.
If fill is to be placed on existing slopes, either natural or man-made, that are steeper than six
horizontal to one vertical (6: 1), then the fill materials should be benched into the existing slopes in such a manner as to provide a good contact between the two materials, break up potential sliding planes, and allow relatively horizontal lift placement.
Final slopes should be as flat as practical to reduce the possibility of creep and shallow slides.
Particularly in cut slopes, the shear strength of the site soils can deteriorate with time. Final side
slopes in cuts or fills of less than five feet in height may be as steep as 2H:1V. Taller sections will require considerably flatter slopes such that slopes of 4H: 1V.
7.4 Global Slope Stability
Proposed slope cross sections were provided by Freese & l\Jichols. One slope cross section in
the failure area was analyzed to serve as a baseline. Three additional cross sections at the final
slopes were developed at the locations nearest the performed borings. The worst case cross
section was then analyzed with the gabion basket wall at the finished slope (adjusted to a 1:1 slope) and again using a stacked gabion baskets as a key into the shale. The slope analyses
were performed using a computer code based on Bishop's Simplified Method after the proposed retention wall is constructed with water levels near current measured levels.
Residual shear strength parameters of 1,500 to 750 PSF in cohesion with an angle of internal
friction of 2 degrees were used for the upper silty clay in-situ soils at unsaturated to semi
saturated states. The saturated soils were analyzed with shear strength parameters of 100 to 200 PSF with angles of internal friction of 2 to 4 degrees. A cohesion of 10,000 PSF was used to
model the shales. An angle of internal friction of 40 degrees in the limestone and a 3,500 PSF
shear strength (tensile) was used to model the gabion baskets. Strength parameters have a factor of safety of 3.
The cross-section diagram and results of the analyses are presented in Appendix B. A minimum factor of safety of about 2 was computed for the gabion basket wall structure placed on the
stacked basket key. These values are considered acceptable based on our engineering judgment and standard industry practice. The gabion wall structure placed upon a 1 to 1 slope
had a factor of safety slightly less than 1.5. Therefore we recommend that a key footing composed of either stacked gabion basket or concrete footing be extended at least 1 foot into the shale.
A factor of safety of less than 1 was calculated on the slope failure area. Factors of safety for the proposed slope sections were generally in the 1.5 range or greater. Therefore Rip/Rap will be
EK'L -7- HC081718
acceptable for these slopes. We recommend reducing proposed upper 5 feet of the slope to a
4H: 1V slope if possible to increase the slope stability at the Broadway East Slope Location.
7.5 Permanent Slopes
Final slopes should be as flat as practical to reduce the possibility of creep and shallow slides.
Taller sections will require considerably flatter slopes, such that slopes 10 feet or more in height ideally should have a maximum slope of 4H: 1V. Site improvements should be maintained well
back of the crest of slopes to reduce the effects of creep or shallow slides.
8.0 LIMITATIONS
The professional services performed for the preparation of this geotechnical report were
accomplished in accordance with current and locally accepted geotechnical engineering principles and practices. The recommendations presented in this report are based upon the data
obtained from the borings at the indicated locations and/or from other information discussed in this report. The possibility always exists that the subsurface conditions occurring between
borings, across the site, or due to seasonal/annual climatic cycles may vary from those encountered in the borings. The nature of these variations may not become evident until during
or after construction. Should subsurface conditions varying significantly from those described herein, EWL should be immediately notified to evaluate the effects on these recommendations
and so supplemental recommendations can be provided. EWL's services should also be retained
for the final review of design plans/specifications so comments can be made regarding interpretation of the geotechnical recommendations provided in this report.
The recommendations provided in this report were prepared for the exclusive use of our client. No warranties, expressed or implied, are intended or made. The information and
recommendations provided in this report are applicable only for the design of the types of structure(s) described in the Site and Project Information section of this report and should not be
used for any other structures, locations or for any other purposes. We should not be held responsible for the conclusions, opinions or recommendations made by others based upon the
information submitted in this report. If changes to the design and/or location of this project as outlined in this report are planned, the recommendations provided in this report shall not be
considered valid unless EWL reviews these changes and either verifies or amends this report in writing. Construction issues such as site safety support of excavations and dewatering
procedures are the responsibility of others.
The scope of services for this report does not include any environmental or biological assessments either specifically or implied. If the owner is concerned about the potential mold, fungi, bacteria, identification of contaminants or hazardous materials and conditions, etc., additional studies should be undertaken.
EW'L -8- HC081718
EWL's capabilities include a full range of construction material testing and observation services.
EWL should be retained to provide testing and observation during excavation, grading, foundation
and construction phases of this project.
We will retain the samples recovered from the borings on this project for a period of 30 days subsequent to the submittal date printed on this report. After the 30-day period, the samples will be discarded unless otherwise notified by the owner in writing.
EINL -9- HC081718
~ __ --~-~ ~ ~ L_____Broadway Road --------
---------~----~ \ ~ . ...B-1 ~. c9
.-0 00' .~
C). ~~
7
B-2 ... &"9
Glenview Drive
1:'0 O'.s'li
erG G,f
~'O~ .~
~'{)
......0 ",'"o
0''O~ ,1'0'\
. ,,~"'~0\'-:) .~0
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t 0\'O~
~-= ~~ ---= --_:: -0 LEG~ (-,,1 c;' _----------!
-~ 20<,r"9 LO(
/I
~ 5CALE
~;
~ 75 15C
FEET
~m'l:;eotechnica, Studies Group. Inc.
E~'::~~~"~~~'~~"i;l:";w;,", ,"eA DIV'SIOI '""Ie
EWL Project No. HC081718
PLAN OF BORINGS Erosion Control/Retaining Wall Structures
Big Fossil Creek at Glenview and Broadway Roads Haltom, Texas
__
-------------------
EWL Geotechnical Studies Group Inc. 4501 Broadway Avenue Haltom City, Texas 76117 Telephone 817-759-9999 Fax 817-759-1888 CLI ENT t-t<i1tom City
PROJECT NUMBER HGQ8J718.
DATE STARTED 4/25108 COMPLETED 4/25/08
DRILLING METHOD Continuous Flight Auger
NOTESl3roadwCiY -E. sideof creek _.. _----- --~_._._--~------- -----------_.._---------
I f--~ 0..';:: W·~
o
o C)
(/)
::0 f Z (5
(/)
" z 5 Q u I (D
I U W f
20
25
(J l-__-L-_.L...
MATERIAL DESCRIPTION
Brown and tan clay (FILL) - with gravel and concrete
Brown silty clay
Tan and gray silty clay
Gray and tan clay
Tan gravelly clay
Gray shale - with limestone layers
Bottom of hole at 40 feet---=::.=.::=.:..:..:....::.:..:..:.::.:.~:.:.......:_=__:_=_=.::_ L- ___.L_ ___L_ _L._ _L._ _'__..J....____J
FIGURE 2
BORING NUMBER B-1 PAGE 1 OF 1
PROJECT NAME Erosion ControIIRetainingWaIlStructl,l!~
PROJECT LOCATION Big Fossil Creel atGlenv!ElwIL~roa~ ..~.~..._----
GROUND ELEVATION N/A
GROUND WATER LEVELS:
V AT TIME OF DRILLING 23.0 ft
• AT END OF DRILLING 16.0 ft
AFTER DRILLING
-I~ f-W -' 0.. :2 <t if)
ST 21 42 14 28P"30
ST p" 4.5+
p" 4.5+ST 15 45 16 29
p" 45+ST 15
Qu" 6.0
p" 4.5+ 14ST
Qu"84
I i I
p" 4.5+ 15 40 12 28~ ST
i
I
p" 1.25 22 45 13 32~ ST
i
i i !
p" 0.25.- ST
I
I I
T" 4 5"/100 ~THD I
I T" 5.25"/100~THD
I
I
.JTHD T " 1.25"/100
2
--
,-----------------------------------------------------...,EWL Geotechnical Studies Group, Inc BORING NUMBER B-2 4501 Broadway Avenue PAGE 1 OF 1Haltom City Texas 76117 Telephone 817-759-9999 Fax 817-759-1888
CLIENT Haltom City PROJECT NAME Erosion Control/Retaining WaH §tru<;tl!!:..es__
PROJECT NUMBER HC081718 PROJECT LOCATION Big Fossil Creel at Glenview&E3ro~dway
DATE STARTED 4/25/08 COMPLETED 4/25/08 GROUND ELEVATION N/A
GROUND WATER LEVELS:
DRILLING METHOD Continuous Flight Auger V AT TIME OF DRILLING 17.0 ft
AT END OF DRILLING Dry
NOTES Broadway - W. side of creek AFTER DRILLING'--T:--r-- .------- ._---..._----- ._-- ----------..if>
I 1- I I-~ 1t01Q..-S <to MATERIAL DESCRIPTION W a:..J o C) i
I I
O--+V"V"""'*~ . . .. ._
\
5
"--_"--
Brown and tan clay (FILL) ST
~\t\Iith 9~avel _ \Q~r15broVilQ::;ilty clay
Brown silty clay ST
Tan silty clay - with calcareous gravel and sand at 12' ST
ST
ST
ST
Gray shaley clay I
I
\~ SS1/
Gray shale i :- with limestone layers
>z (3
::x)
8 T
co z L ~l
o U T D)
tj OJ
o ~.
W':.:J'--__
3: coo . _. alL' LL-C ::Jf- ZI ':=c Uzu I- z gl- -x O~~~ CY~ g-~ UJW i=':= ~w Ue...::J.3 -f- ::J(/)~~(DU?Q)
UJ~ 1-0Oz O~ UJ~.c ~ ~ 9-~ >- UJz __ U 0 OJ '<"0 ~O ::::;..J :5::::; Wa: U 0... :5- zm.<=: 1:-: 0.. =i a o
0... LL. Z f- 0.. [y' a 0::
\ P =2 7~ 18 42 15 27
P =4.5+ 19 48 16 32
P =4.5+ 17
Qu = 5.8
P =4.5+
P =4.5+ 12 39 13 26
ro =4 5+
N = 37 17 44 13 31
--- ---------,-----1 IATTERBERG z
w~ IMIT W a:~ >- I
~ THO T = 8 75"/100
I I I
~THD T = 3"/100
I I I I
i
~ THD I T = 1 5"/100
Bottom of hole at 35 feet
-'-- ---'-_--'-_-'-_--'-_-'-_-'------J
FIGURE 3
EWL Geotechnical Studies Group, Inc 4501 Broadway Avenue Haltom City, Texas 76117 Telephone: 817-759-9999 Fax 817-759-1888 CLIENT ~altom City
PRO.IECT NUMBER. HC081?113
DATE STARTED 4/25/08 COMPLETED 4/25/08
DRILLING METHOD Continuous Flight Auger
MATERIAL DESCRIPTION
Dark brown silty clay
Tan and gray silty clay - with calcareous sand and gravel
Tan and gray shaley clay
Gray shale - with limestone layers
J)
z ~, ::J o o
T U
g Ll...'OL-__..L_..L
Bottom of hole at 30 feet.
BORING NUMBER B-3 PAGE 1 OF 1
PROJECT NAME Erosion Control/Retaining vyall Stru_cture~ _
PROJECT LOCATION Big Fossil Creel at Glenvie\IVJl.!3roadw~_
GROUND ELEVATION N/A
GROUND WATER LEVELS:
V AT TIME OF DRILLING 12.0 ft
AT END OF DRILLING Dry
AFTER DRILLING
If)
w D- o '" rn>- ~-..l- oU:: c
o· 'Q)w ~::o-cg~-' U)~~Q)U3Q)DS ..c: ~ ~ .9-0...:;0:>
<! 65 ~~~~.b (/) .:-: .... :00
ZI-D-Q'OQ' ..
ST P = 4.5~
P = 4.0 ST Qu=3.7
ST P= 4.5+
ST P = 4.5+
P= 3.25ST
Qu 03.5
N = 14
T = 8"/100
T = 2.5"/100 ~TH[)
I I
I ' I
!
aJ THO T = 675"/100
~ t::c zu :::J,2, >Q' 0
w~ Q'~
:::JII- z(/)w-IOZ :;0:>0
U
21
19
14
14
23
_._~,---------
IATTERBERG Z
I IT w I> ZIU -x O~gl- i=t: gw U~:::J (/):;0:> 1-0O~ <!- (/)z (/)
::J-' -,-' w D- 5- Z
D- i:i:
44 15 29
44 14 30
60 16 44
.J..- --L-_--L-_J-_J-_J-_-'--_
FIGURE 4
SOIL CLASSIFICATION CHART SYMBOLS TYPICAL
MAJOR DIVISIONS DESCRIPTIONSLETTER
WELL-GRADED GRAVELS, GRAVELCLEAN SAND MIXTURES. LITTLE OR NO GWGRAVEL GRAVELS FINES
AND GRAVELLY
POORLY-GRADED GRAVELS, SOILS GRAVEL - SAND MIXTURES, LITTLE GP
OR NO FINES
COARSE GRAINED GRAVELS WITH SILTY GRAVELS, GRAVEL - SAND
MORE THAN 50% GM SILT MIXTURES OF COARSE
F SSOILS INE FRACTION ~()/;f;'7.::a*;x~v,~----t-----------l
RETAINED ON NO 4 SIEVE (APPRECIABLE ~ '/ ~ GC CLAYEY GRAVELS. GRAVEL - SAND
AMOUNT OF FINES) ~ '/ y A;'/ CLAY MIXTURES tv: ;//W~
Q 0 " 0 0 0 ~ 0 Q
Q 0 " 0 0 0 Q Q
0000 Q 0 0 Q 0 o 0 0 0 ~ Q 0 0
Q 0 Q 0 0 0 Q"c WELL-GRADED SANDS, GRAVELLY ~ 0 0 0 0 0 0 <~ 0 0 0 ~ 0 • 0 aCLEAN SANDS
Q 0 0 0 0 ~ " 0 SW SANDS. LITTLE OR NO FINES Q Q 0 0 0 Q ~ 0 0SAND 00000 •••MORE THAN 50%
o 0 Q Q 9 0 ~ 0 "AND LARGER THAN
OF MATERIAL IS SANDY
NO 200 SIEVE POORLY-GRADED SANDS, SOILS (LITTLE OR NO FINES) SP GRAVELLY SAND, LITTLE OR NO FINES
SIZE
SANDS WITH SILTY SANDS. SAND - SILT MORE THAN 50% SM MIXTURESFINES
OF COARSE FRACTION
PASSING ON NO 4 SIEVE (APPRECIABLE CLAYEY SANDS. SAND - CLAY
AMOUNT OF FINES) SC MIXTURES
INORGANIC SILTS AND VERY FINE SANDS. ROCK FLOUR. SILTY OR IVIL CLAYEY FINE SANDS OR CLAYEY
I !
•I SILTS WITH SLIGHT PLASTICITY
INORGANIC CLAYS OF LOW TOSILTS FINE LIQUID LIMIT MEDIUM PLASTICITY. GRAVELLY Af\ID LESS THAN 50 CL CLAYS, SANDY CLAYS. SILTY GRAINED CLAYS CLAYS. LEAN CLAYS
SOILS
ORGANIC SILTS AND ORGANIC OL SILTY CLAYS OF LOW PLASTICITY
MORE THAN 50% INORGANIC SILTS, MICACEOUS OR OF MATERIAL IS MH DIATOMACEOUS FINE SAND OR SMALLER THAN SILTY SOILS NO. 200 SIEVE
SIZE SILTS
LIQUID LIMIT INORGANIC CLAYS OF HIGH AND CHGREATER THAN 50 PLASTICITYCLAYS
ORGANIC CLAYS OF MEDIUM TO OH HIGH PLASTICITY. ORGANIC SILTS
PEAT. HUMUS, SWAMP SOILS WITH HIGHLY ORGANIC SOILS PT HIGH ORGANIC CONTENTS
GRAPH ... w .... w ... ..•~~
•• ~•• ~ ~ .•..•.... ....
p,-,~. 0 't' "-~ °l) "-.;'r).~c:Do ·.Je C)
P~ t"l 00 >.
NOTE DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS Figure 5
Failure Area X-Section Safety Factors
121.00
0.92
0.98
0.99
1.01
1.03
1.04 72.60 1.06
1.06
1.07I
1.0848.40
I I
24.20
0+ 24~20-- -,--o 48.40 72.60 96.80 121.00 145.20 169.40 193.60
96.80
Broadway East Slope
121.001
96.80
72.60
48.401
24.20j
O+--~---
Safety Factors
1.49
1.50
1.52
1.57
1.60
1.63
1.65
1.67
1.68
1.68
~j o 24.20 48.40 72.60 96.80 121.00 145.20 169.40 193.60
Broadway East Slope Safety Factors
121.00 1.47
1.48
1.48
1.48
1.50
1.50 72.60~ 1.52
1.54
1.55I
1.5648.40 1
I
24.20
I
I
01o 24.20 48.40 72.60 96.80 121.00 145.20 169.40 193.60
96.80
Broadway East Slope w/Gabion Wall Safety Factors
121.00 1.95
2.00
2.0496.80
2.04
2.05
2.06
2.07
2.07
2.10
2.11
24.20 48.40 72.60 96.80 121.00 145.20 169.40 193.60
72.60 1
I
I48.40'
I
24.20
I
01o
Broadway West Slope Safety Factors
121.00
96.80
72.60
48.40J
24.20
01o 24.20 48.40 72.60 96.80 121.00 145.20 169.40 193.60
1.72
1.73
1.75
1.75
1.77
1.78
1.80
1.83
1.85
1.90
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