Sandy Lk Addn 1B-AG 920811 AGENDA REQUEST FORM
~ CITY COUNCIL MF. ETING August 11, 1992 ITEM NUMBER
ITeM CAPTION:
Consideration of approving a variance to the Subdivision Ordinance Appendix A-I-D-I-J,/..~,~e_
21 entltlea r'~-~-:-,-.I rite) tO allow 5" thick concrete pavement in the parking lot area
'- %.. .. , instead of 6" thick concrete pavement.
OTHER REP.: Gre~ Hunt
Tri-Star Construction
EVALUATION OF ITEM: DATE: Aug.,st 5, lqqZ
Mr. Leo Wehkamp of Tri-Star Construction, Inc. has requested a variance tO the Subdivision
Ordinance to construct $" thick concrete pavement in the Sandy Lake Animal Hospital parking
lot instead of 6" concrete pavement. Staff has no objections to the request.
Mr. Wehkamp also requests a waiver of the requirement for the lime stabilization. However,
Appendix A-I-D-I-a allows the waiver if the P.I. is between 6 and 12. As per the attached soil
report by Mr. Dahlin, the P.I. falls within the acceptable range and the requirement for lime was
waived by staff.
Staff recommends approval of the above request for variance to the
APPROVED
DATE
BUDGET AMT. ,~l'///,~ AMT. ES'I~MATED
AMT +/- BUDGET FINANCIAL ~EW BY
COMMENTS:
LEGAL REVIEW BY: REVIEWrED BY CM:~~
AGENDA KEQUEST FORM REV~S~) 1/91
~uv. 4-24-i19 ¢ ORT DOCL~IENTATION FOR AGENDA ITI~2'I
ST,~d~P RECEIVED BY CITY F.~NAGER'S OFFICE:
SUPPORT DOC[~r~NTATION SL'BMITTED I~ITB ACENDA ITEN: /Re. OF ORIGINiLS ilEQUIREI)
· ~E~lOS/ ~/. I e~ch
BILLS/MINUTES :Q _ .
CC%~F~'.CT/ACP£L-V~NT ................. : 3 originals for signature
C.l.P. CONTRACT ..................... : 6 ori$inal8 for signature
m
CHANGE ORDERS ....................... : 3 originals for signature
ORDINANCE ........................... : 1 blueback for signature + 3 copies
CAPTION ............................. : 1 blueback for signature + 3 copies
RESOLUTION .......................... : 2 blueback~ for signature + 1 copy
PROCLANATION ........................ : 2 bluebacks for signature + I copy
BID ................................. : I each
LOCATION MAPS ....................... : 12
ZONING PLA~S ........................ : 12
PRELIHINARY/FINAL PLATS ............. : 12
SITE PI~S .......................... : 12
LANDSCAPE PI,~S ..................... : 12
ARCHITECTURAL REI~DERING$ ............ : 12
DATE PUBLISRED IN TRE ClTIZ~NSfADVOCATE:
NOTIFICATION TO:
DATE/NETBOD OF COW[ACT:
NOTES
2%~ $.".EET. 0588DS
TRI-STAR CONSTRUCTION, INC.
Mr. Ken Griffin 8-3-92
City of Coppell
Re: Variance Request
]07 Samuel
We respectfully request a variance to the Sub-Division
Ordinance to change the thickness of the concrete parking lot
from 6" thick to 5" thick. We also request that the requirement
for lime stabilization be waived for the parking lot. This
request is made due to the results of the soils report that
the Plasticity Index. of the soil is less than ]2.
Thank you for your consideration of this matter.
Leo Wehkamp
Pres.
TRI-STAR CONSTRUCTION, INC.
Ph.3NE 2:-'-2'2';-~55E · FAX:-2';~ 22'-467~
GEOTECHN I CAL ENGINEERING CONSULTANT
1923 CHALICE ROAD ARLXNOTON, TEXAS 76014 817/277-5849
June 15, 1992
Pile No. WPD9228
Mr. Leo Wehkamp
Tri-Star Construction
535 West Purnell, Suite 110
Lewisville, Texas 75057
Re: Geotechnical Engineering Services
Sandy Lake Animal Hospital
Samuel Blvd at Sandy Lake Road
Coppell, Texas
Dear Mr. Wehcamp;
AUTHORIZATION:
On Thursday, June 11, 1992, by phone, you requested that I perform
evaluations on pavement subgrade soil, foundation plans and foundation
installation for the subject project. The following is a geotechnical
engineering report of my findings.
FXELD INVESTIGATION:
In the early evening of Friday, June 12, 1992, I traveled to the site,
picked up a set of three 8.5" by 11" foundation plans, pier drilling
notes, and a copy of an invoice for pier concrete. These items were left
for me and were in an envelope attached to the door of the construction
trailer. 1 observed foundation pier layout, dowelled tops of completed
piers and the excavated soils around the tops of piers and from plumbing
installation. I also sampled the pavement subgrade at four locations. I
was unaccompanied on site.
Later in the evening of June 12, 1992, I talked by phone with Mr. Greg
Hunt, the on-site project superintendent, to review my installed pier
foundation observations and to compare them with the foundation plans and
Mr. Hunt's observations and knowledge of the actual pier drilling and
pier concrete placement work.
The following laboratory test data were obtained on the four pavement
subgrade samples which I obtained from the site on June 12, 1992.
Sample Soil Description ~nd Liquid Plastic Plasti¢it¥
No.: uses Classification: Limit: Limit: Index:
1. Brown Clayey Sand (SC) 22.7 13.6 9.1
2. Dark Brown Clayey Sand (SC) 22.9 13.7 9.2
3. Brown Clayey Sand (SC) 25.8 14.9 10.9
4. Dark Orayish Brown Clayey Sand (SC) 25.1 14.4 10.7
PAGE 2.
Sandy Lake Animal Hospital
PAV~MENT~UBGRADE Continued:
The general locations of the composite subgrade soil locations were:
No. 1, south half of east parking lot section
No. 2, north half of east parking lot section
No. 3, east half of north parking lot section
No. 4, west half of north parking lot section
LIME STABILIZATION:
It is this engineers opinion that the existinc claYeY sand alluvial
sub, fade soils do not require lime stabilization for the proposed
concrete drive and parking pavement sections on this project. Normally,
lime stabilization is required under asphaltic (flexible) pavement and
highly loaded (roads) concrete (rigid) pavement sections, especially
wherever subgrade soils have plasticity indeces in excess of about
fifteen (15) in this active clay soil area of Texas. It is this
engineer's opinion and experience that lightly to moderately loaded
Portland cement concrete parking lots and drives perform adequately
whenever these pavement sections are of sufficient thickness, strength,
and contain at least number three (#3) reinforcement bars on 18" to 24"
centers or the equivalent of welded wire mesh reinforcement.
The pavement subgrade on this project should be compacted in individual
loose lifts not to exceed 9" and to a minimum of 93% of Standard Proctor,
ASTM D-698, at or near the optimum compaction moisture content, fT~e..
est~t~d'St~ndard proctor maximum dry.densit~ and..optimummoistur%
'content [or a composite oE the four sampled-:aub~cle .~o$'iS"i~"'[16'-~cf- at
13%. 93% of the estimated maximum dry density is 108 pcf.
FOUNDATION PLANS:
The foundation plans prepared by Nicol & Holland Associates, Inc.,
consulting structural engineers, of Boulder, Colorado, dated May 14,
1992, appear to be in qeneral accordance with my ueotechnical enqineerinq
report (WPD2224) prepared for the owner, Dr. Stephen King, and submitted
on May 15, 1992.
PIER FOUNDATION INSTALLATION:
From my phone conversation Mr. Greg Hunt and from a concrete invoice by
Charley's Concrete Company, Inc. of Keller, Texas, it appears that the
project's straight, reinforced concrete piers were drilled and placed on
Friday, June 5, 1992. A total of 1, 24" diameter pier and 26, 18"
diameter piers were planned. Apparently one 18" diameter pier was
inadvertently drilled to a diameter of 24" according to Mr. Hunt.
Planned pier depths were to be 11' below existing grade. Notes prepared
by the contractor and my phone conversation with Mr. Greg Hunt indicate
that the project's piers were drilled and placed to depths of between 14'
to 15'. The over drillinq 9~ She planned depths by approximately ~,5'
does Dot appear ~o adversely affect the overall foundation desiun indent
and should not affect ~he performance 9~ the presently existing piers.
PAGE 3.
Sandy Lake Animal Hospital
PIER FOUNDATION INSTALLATION Continued:
The primary purpose of designing the piers to be placed at a depth of 11'
below existing grade was to minimize pier drilling and concrete placement
probIems normally associated with caving and water seepage in alluvial
granular soils. A clayey sand stratum appears below depths of between
11.§' to 12' on the two Logs of Boring prepared by Parkland Engineering
and Testing, Inc. for the project. This particular stratum appears to
grade to silty sand (decreasing clay content) with some gravel with
depth. Water seepage was apparently encountered in the two borings at
15' and 18' These depths are below the 14.5' average drilled and placed
pier depth. Of note is the fact that a large percentage of drilled and
underreamed concrete shafts are commonly placed at a depth of
approximately 15' in suitable clay strata in this area of Texas.
Mr. Hunt stated that seepage was encountered in only one pier hole and
this was apparently in the vicinity of the southwest corner of the
building. My on site observations soils excavated from the pier holes
indicated that silty clayey sands to silty sands were encountered in the
lower depths of some pier holes. It is this enqineer's opinion, based
upon available data, my training and experience, and my conversation with
Mr. Greg Hunt, that negligible, if any, drilled pier foundation
installation problems, relating to soil caving and subsurface seepage,
were encountered by the responsible contractor or their subcontractors on
June 5, 1992, and that the piers should perform as designed.
CLOSING:
Should there be questions regarding this geotechnical engineering report
or other concerns of which I can be of assistance, please contact this
engineer writer at the letterhead address.
William P. Dahlin, P.E.
cc: Dr. Stephen King
600 East Sandy Lake Road
Coppe!l, Texas 75216
Mr. Paul Hofland, P.E.
Nicol and Holland Associates, Inc.
4730 Walnut Street, Suite 210
Boulder, Colorado 80301
19. A. Consideration and approval of awarding Bid No. Q-0792-02
for "physical fitness equipment" to Diamond
Fitness/Medical in the total amount of $5,068.00.
B. Consideration to award bid for concrete pavement repairs
on Bethel School Road to B. J.Scott Construction, Inc.
for a total not to exceed $15,294.00.
C. Consideration of awarding a bid from Tony Crawford
Construction to provide Phase One development of Andrew
Brown Jr. Community Park, west of Denton Tap Road, in the
amount of $258,689.
D. Consideration and approval of a final plat of Waters Edge
Addition, located 664' north of Sandy Lake Road, along
with the west side of MacArthur Boulevard, at the request
of Matthews Southwest Investments.
E. Consideration and approval of a final plat of Riverchase,
located at the intersection of Beltline Road and
MacArthur Boulevard, at the request of Republic Property
Group.
F. Consideration and approval of the certification of the
1992 anticipated collection rate for the period of July
1, 1992 anticipated collection rate through June 30,
1993, and the amount of excess debt collections during
the period of July 1, 1991 through June 30, 1992.
G. Consideration and approval of a contract with Haynes &
Boone for Consulting Services in the area of personnel
administration up to the amount of $4,?00 and authorizing
the City Manager to sign.
H. Consideration of approving a variance to the Subdivision
Ordinance for the use of 5" thick concrete paving the
Andrew Brown Jr. Community Park, as requested by staff.
I. Consideration of approving a variance to the Subdivision
Ordinance Appendix A-I-D-l-1 (Page 21 entitled Parking
Lots) to allow §" thick concrete pavement in the parking
lot area of the Sandy Lake Animal Hospital instead of 6"
thick concrete pavement.
Councilman Robertson moved to approve Consent Agenda Items 19 A, B,
F, H, and I as submitted. Mayor Pro Tem Smothermon seconded the
motion. The motion carried 7-0 with Mayor Pro Tem Smothermon and
Councilmen Weaver, Thomas, Morton, Mayo, Robertson, and Garrison
voting in favor of the motion.
Consent Items 19 C, D, E, and G were pulled by Council and staff
from the agenda to be discussed separately.
Item 19/C. Mayor Pro Tem Smothermon moved to approve the
substitution of "west" to "east" as a correction to
the agenda item awarding a bid from Tony Crawford
Construction to provide Phase One development of
Andrew Brown Jr. Community Park, east of Denton Tap
Road, in the amount of $258,689. Councilman Weaver
seconded the motion and the motion carried 7-0 with
Mayor Pro Tem Smothermon and Councilmen Weaver,
Thomas, Morton, Mayo, Robertson, and Garrison
voting in favor of the motion.
Item 19/D. Mayor Pro Tem Smothermon moved to approve a final
plat of Waters Edge Addition, located 664' north of
CM081192
Page 6 of 7