SS9701-CS 970123January 23, 1997
J0555 Newki~k
S u i I e 530
Dallas, Texas ?5220
972.83 1.1 1 1 1
t-AX 972.831.0800
The City of Coppell
255 Parkway Boulevard
P. O. Box 478
Coppell, Texas 75019
Attn:
Mr. Kenneth M. Griffin, P.E.
Assistant City Manager
City Engineer
PROPOSAL FOR GEOTECHNICAL CONSULTING SERVICES
Creek Bank Stability
Grapevine Creek - Beltline and Mockingbird
Coppell, Texas
PBT Proposal No. 97-114
Dear Ken:
Patton, Burke & Thompson (PBT) is pleased to submit this written proposal, in accordance with our
January 17 1997 site visit and conversations with you and Garreth Campbell, for performing certain geotechnical
consulting services for the referenced creek bank.
GENERAL
It is our understanding, based on our discussion, the site visit on January 17th, review of construction
plans for earlier vicinity sewer lines, readily available topo maps provided by you of the site area, review of
geotechnical investigation reports by Southwestern Laboratories (May 4, 1992) and Reed Engineering Group
(September 16, 1994), and our past experience with the geological formations which exist in the assignment
area, that the following basic information is currently known about the area to be investigated:
The creek bank to be investigated is approximately 200 to 250-LF of the north bank
(approximately between Station 39+00 and 41+25 of the Grapevine Creek Sewer Trunk Main
Project), just south of the residence property at 776 Crestview Ct.
Patton, Burke & Thompson
The Cigt of Coppell
Grapevine Creek
Page 2
Overall construction for the sewer trunk main project in this area was started in late-1993 and
primarily involved (i.e., for the purposes of discussions for this specific assignment) the micro
tunneling of a 30-inch diameter, PVC line at a depth below the existing grade of approximately
20-feet. This new line replaced an existing 1965, 12-inch sanitary sewer line located
approximately 8 to 10-feet north of the new sewer line alignment. Furthermore the old line is
at an elevation levd approximately 5-feet higher than the new line, the old line was constructed
by open cut excavation methods and was taken out of service upon completion of the new line.
Although there is considerable history of development and activities along this stretch of
Grapevine Creek, a portion of the creek's bank, immediately to the east of the current study area,
was investigated for a landslide condition in early to mid-1994. A geotechnical investigation
study and eventual stabilization construction remediation procedure is described in the 1994
Reed report.
In addition to the creekbank instability there is an existing relatively large, brick home, swimming
pool and general residential features located immediately north and on top of the existing overall
bank area. (i.e, resident located at address 776 Crestview Court). City records indicate that the
building permit application for the home was obtained in October of 1991 and for the pool in
February 1992. During our site inspection visit on January 17th with representatives of the City,
no obvious signs of movement or distress were noted for the subject residential property,
(however, a detail inspection was not made at this time).
A btief review of the various topographical maps provided by the City at this time indicates that
there could be considerable filling which has occurred through this general area in the overall
process of developing the subdivision lots, particularly the subject lot at 776 Crestview Court.
Based upon this topographical information, the referenced 1994 Reed report and vicinity new
sewer trunk main subsurface information developed by Southwestern Laboratories, and our past
experience in the City of Coppell, the subject study area is believed to be underlain by the Eagle
Ford shale formation (both the weathered and eventual unweathered shale sections) overlain by
Alluvial deposits and/or fill soil materials. The depth to the unweathered shales on the top of the
bank (i.e., generally at the elevation level of the residential construction) is estimated fi.om
available information to be 15 to 20-feet; however, to the south through the area of the slide the
depth and extent of the various materials could be quite variable due to the movement activities.
The principal purpose of this geotechnical investigation, as PBT understands it at this time, is to carry
out a geotechnical engineering investigation and to provide consulting services to assist the City in quantifying
what is responsible for the current landslide and movements, and to develop stabilization alternatives for this
reach of the Creek.
SCOPE OF WORK
The scope of work proposed by PBT at this time, based upon all of the above information and our
extensive past experience with slope stability problems, will consist of developing a technical approach,
Patton, Burke d; Thompson
The City of CoppeLI
Grapevine Creek
Page 3
performing the necessary geotechnical investigations and analysis, development of alternatives and
recommendations for slide stabilization, and general consultation with the City.
The following describes the general scope of work we propose at this time for carrying out the necessary,
in our opinion, services for the study area:
1. Field Investigations
a)
Geotechnical - type borings will be drilled and sampled using a truck or trailer mounted drill
rig where possible, and a portable drill fig, in the more inaccessible areas. The magnitude
of the envisioned field program would involve five (5) or six (6) borings: two (2) taken on
top of the bank with a truck or trailer rig (western portion of study area), one (1) on top of
the bank with a trailer fig or portable rig (eastern portion of study area), and two (2) or three
(3) with a portable dg along the slope and bank toe areas. [Note: We are attempting to use
the boring information previously developed by others through-out the area as much as
possible.]
b)
No surface monitoring or surveying is currently proposed to be performed by PBT, but
temporary groundwater measuring tubes will be installed in selected boreholes, depending
upon the groundwater conditions actually encountered.
2. Assumptions Regarding Site and Field Work:
The borings will be located in the field based upon measurements fi.om existing features. The
City will assist PBT in developing elevation control at the study area and true scale X-
sections of the existing groundline through the slide area.
No special permit or permission will be required of PBT to enter the site that will result in
a delay or additional cost.
· Final selected boring locations will be free of either overhead or underground obstructions.
Assignment assumes that only non-contaminated/non-hazardous soils will be encountered
during the field exploration program. Otherwise, the proposed cost for the field and
laboratory investigations will need to be revised.
No extended inclement or severe weather conditions will be encountered during the actual
field program. Should this condition occur, we will contact you immediately regarding
continuing to remain on site, or de-mobilize the field program to a later date.
Geotechnical Laboratory_ Testing - The final laboratory testing program will depend upon the
actual subsurface conditions encountered in the test borings and soil samples/rock cores recovered,
but in general is envisioned to involve the following:
Burke & Thompson
C~#gif~eed, g ¢of~suItanrs
Thc City of Coppcll
Grapcvinc Creek
Page 4
Moisture content, unit weight, Atterberg limits and grain size analysis on selected soil
samples to evaluate classification and consistency properties, and rock core recovery, rock
quality designation and unit weight on recovered rock cores to evaluate rock quality and
classification.
· Soil suction tests to assist in the evaluation of the depth of wetting of the slope materials.
Q-Triaxial and/or direct shear on in situ natural and tH site soils and weathered shales for
utilization in slope stability analysis.
· Other laboratory tests as deemed appropriate upon evaluating findings of borings.
Engineering Analysis/Written Report - The full extent of the analysis will depend upon the actual
findings of the field and laboratory testing programs, but is envisioned at this time to include the
following:
· Site soil stratigraphy, subsurface conditions and associated variability.
Evaluation of physical, consistency, shear strength and soil suction potential characteristics
of subsurface soils, and weathered shale.
Evaluation of timings and development of conclusions regarding probable mechanism and
cause(s) of bank instability to date.
Recommendations regarding technical and practical alternatives for the geotechnical
engineering design and construction of slide remediation.
SCI:I'EDULING OF WORK
Patton, Burke & Thompson will develop a firm schedule for the geotechnical exploration program
immediately upon your authorization of the services outlined in this proposal. The field program, barring any
bad weather, is estimated to be completed in 2 to 2-1/2 working days after mobilization to the site. The
laboratory testing program, for selected soil samples and rock cores retained fi.om the borings, will be completed
within ten (10) working days after field program completion. [Note: Most of the lab work, with the exception
of shear tests, will be completed within five (5) working days.] Preliminary verbal findings, if desired, can be
presented within four (4) working days aRer completion of the field and laboratory programs. The final written
report will be submitted within six (6) working days following the preliminary verbal findings.
PRICING/CONTRACTING
Patton, Burke & Thompson proposes to perform the work for this investigation on a time and materials
basis, for the scope of work outlined above, for a maximum not to exceed budget as outlined below:
Pa~ton, Burke · Thompson
The City of Coppell
Grapevine Creek
Page 5
a. Field Explorations (including engineering field logging personnel)
b. Laboratory Testing
c. Engineering Analysis and Written Report(s)
$2,960.00
2,245.00
3.420.00
Total Estimated Maximum Not-to-Exceed Budget
$8.625,00
Furthermore, we propose to provide all ~ervices in accordance with PBT's General Terms & Conditions (Form
1-95/A), and any additions or modifications to the above referenced scope of work, with prior approval by you,
will be in accordance with PBT's Schedule of Charges (Forms 4-96/B and 5/96L).
Patton, Burke & Thompson is pleased to have the opportunity to submit this geotechnical investigation
services proposal to the City of Coppell, and we look forward to being of continued professional service. If you
have any questions in regard to the content of this proposal, or if additional input is desired, please feel flee to
contact the undersigned.
To authorize this work, please sign and return one copy of this agreement to us.
Very truly yours,
PATTON, BURKE & THOMPSON
JWB:jp
97-114.pro
Enc: Assignmeat Authorization
General Terms and Conditions
Schedule of Charges (2)
Pu~*on, BuriEe ~ Thompson
Engineenng Consultants
The City of Coppell
Grapevine Creek
Page 6
ASSIGNMENT AUTHORIZATION
The City of Coppell hereby agrees to the terms of this proposal and the attached General Terms and
Conditions (Form 1-95/A), and the attached Schedule of Charges (Forms 4-96/B and 5/96L)..
Proposal accepted by:
City of Coppell*
Name Company
Title Date
*Individual with financial authority to commit to this Assignment Authorization
I
Patton, Burke & Thompson ·
Patton, Burke & Thompson
General Terms and Conditions
1.0 General
Patna, Burke & Thompson (PBT) by the performance of services covered hereunder, does not in any way assume any of
those duties or responsibilities with regard to the project's design professionals or any other design agencies or authorities.
Client agrees to furnish or cause to be furnished to PBT, all documents and information known to client that relate to the
identity, location, quantity, nature or characteristics of any hazardous or toxic materials on or near the site. In the event that
test samples obtained during PBT"s work contain substances hazardous to health, safety, or the environment, these snmples
remain in the property of the client.
2.0 Billing
PBT will submit progress invoices to client monthly and a final invoice upon completion of services. Each invoice, on
presentation, is due and payable by client or his authorized representative. Payment is past due 30 days from invoice date.
Client agrees to pay interest of one and one-half percent (1-1/2%) per month, (but not exceeding the maximum rate
allowable by law), on past due accounts. Any attorney's fees or other costs incurred in collecting any delinquent amount
shall be paid by client.
3.0 Standard of Care
PBT services will be performed, within the limits prescribed by its clients, with the usual thoroughness and competence of
the engineering cxmsulting profession, and in accordance with the standard for professional services at the time and under
similar conditions tlmse serviees axe reoxlere& No other warranty or representation, either expressed or implied, is included
or intended in PBT's proposals, contracts, or reports.
4.0 Liability
PBT's liability shall be limited to injmy or loss caused by the negligence of PBT, its subcontractors, and/or agents
hereunder. PBT has neither created nor contributed to the creation or existence of any hazardous, toxic, pollutant, or
otherwise dangerous substance or condition at the site, and its compensation hereunder is in no way commensurate with
the potential risk of injury or loss that may be caused by exposure to such substances or conditions:
PBT's liability for injury or loss arising from (1) professional errors or omissions and/or (2) any hazardous, toxic, pollutant,
or waste gases, liquids, or solid materials shall not exceed $5,000 or our fee, whichever is greater.
PBT's liability for injmy or loss arising from comprehensive general and automobile exposures shall not exceed $ ~ 00,000.
The client agrees to defend, indemnify, and hold PBT harmless from any claim, liability, or defense cost in excess of the
limits stated herein for injury or loss sustained by any patty fi.om exposures allegedly caused by PBT's performance of
services hereunder.
In the event the client makes a claim against PBT, at law or otherwise, for any alleged error, omission or other act arising
out of the peffonnavxe of its professional services, and to the extent the client fails to prove such claim, then the client shall
pay all costs, including attorney's fees, incurred by PBT in defending itself against the claim.
5.0 Applicable Law
All general terms and conditions shall be governed by the laws of the State of Texas.
PATTON, BURKE & THOMPSON
SCHEDULE OF CHARGES
The compensation to Patton, Burke & Thompson (PBT) for professional services is based upon and
measured by the following charge elements.
1.0 Personnel Charges
Charges for PBT employees and consultants are based upon hourly rates for the following general labor
categories:
Engineering Technician I ..................................... $29/hr
Engineering Technician II ..................................... $31/hr
Engineering Technician 11I .................................... $33/hr
Senior Engineering Technician ................................. $35/hr
CWI/Stmctural Steel Inspector ................................ $40/hr
Word Processor/Secretary .................................... $30/hr
Drafting ................................................... $35/hr
Staff Engineor .............................................. $45/hr
Geologist .................................................. $55/hr
Project Engineer ............................................ $55/hr
Senior Engineer ............................................ $85/hr
Principal ................................................. $105/hr
Expert Witness (Deposition & Trial) ........................... $125/hr
[Note: Time spent in either local or inter-city travel, when travel is in the interest of the work, will be
charged for in accordance with the foregoing schedule; however, for non-local travel by public carder a
maximum of eight hours per day will be charged.]
2.0 Equipment Charges
PBT equipment, if used, will be billed at the rates noted in the proposal.
3.0 Other Services and Supply Charges
Charges for services, equipment and facilities not furnished directly by PBT, and any unusual items of
expense not customarily incurred in PBT's normal operations, are computed as follows:
Cost plus 15 percent includes surveying services, land drilling equipment, construction equipment,
testing laboratories, shipping charges, subsistence, transportation, outside printing and reproduction,
long distance communication, special supplies and rentals.
Cost plus 20 percent includes aircraft, watercraft, and marine drilling equipment.
FORM (04-96/B)
PATTON, BURKE & THOMPSON
SCHEDULE OF LABORATORY TESTING CHARGES
Visual Unified Classification, sample ............................ $ N/C
Natural Moisture Content ........................................ 5.00lea
Unit Weight ................................................. 10.00/en
Specific Gravity .............................................. 40.00lea
Atterberg Limits (Wet Method) .................................. 35.00lea
Grain Size Analysis, #200 sieve only ............................. 20.00/en
Grain Size Analysis, 1-inch to #200 sieve .......................... 35.00/ea
Hydrometer Analysis .......................................... 70.00/ca
Lime Series (LL & PL) ........................................ 155.00/en
Unconfined Compression, peak stress only ......................... 35.00/ca
Unconfined Compression, with stress/strain curve ................... 55.00lea
Triaxial Shear (UU), per point, peak stress only ..................... 85.00/en
Triaxial Shear (UU), per point, w/stress-strain ..................... 110.00/ca
Triaxial Shear (CU), per point, w/stress-strain ..................... 250.00/ca
Triaxial Shear (CU w/pore pressure), per point, w/stress-strain ........ 305.00/en
Direct Shear (UU), per point, w/stress-strain ...................... 120.00/ea
Direct Shear (CU), per point, w/stress-strain ....................... 140.00/ea
Direct Shear (CD), per point, w/stress-strain ....................... 160.00/ea
Soil Suction (filter paper) ...................................... 20.00/ea
One-Dimensional Swell ........................................ 35.00/ea
One-Dimensional Swell with Load Back ........................... 55.00/ea
One Dimensional Swell with Load Back &Rebound .................. 75.00/ea
Consolidation- w/o Time Plots ................................. 190.00/ea
Consolidation - with Time Plots ................................. 250.00/¢a
Falling or Constant Head Permeability ........................... 175.00/ea
Flexible Membrane Permeability ................................ 300.00/ea
Standard Compaction ........................................ 115.00/ea
Modified Compaction ................................. ~ ......135.00/ea
CBR O-points, includes proctor) ................................ 325.00/ea
pH ..................................................... 20.00/ea
Water Soluble Sulfates ......................................... 30.00/¢a
Resistivity (natural moisture and saturated) ........................ 40.00/ea
Concrete Mix design review .................................... 100.00lea
Cylinder Compressive Strength .................................. 11.00lea
Compressive Strength of Concrete Cores .......................... 20.00lea
Compressive Strength & Density of Concrete Cores .................. 29.00/ea
Splitting Tensile & Density of Concrete Cores ...................... 29.00lea
Flexural Strength of Cast Beams ................................. 15.00lea
Concrete or Asphalt Coring ..................................... 85.00/hr
Asphalt Mix Design Review ................................... 200.OO/ea
Hveem stability & density (w/Theoretical Maximum Density) ......... 200.00lea
Extraction and gradation ...................................... 140.00lea
Form (05/96/L)
9?28510800
01-23-1997 05:28PM FRO~-~ PATTON, BURKE & THOMPSON TO ' 9723043570 P.O1
PATTON, BURKE & ~THOMIF~ON
Engineering ~n~ul~nt~
10555 Ne~irk, Sult~ 530
Dallas, TX 7522p
Phone No: (972) 831~-1111
Fax No: (972} 831-0800
/
. CO R $HE
DATE:~ F~ NO:~~
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