SC-Pinkerton E1-CS 910308March 8, 1991
Mr. Steve Goram
Director of Public Works
City of Ooppell
732 Deforest
Coppell, Texas 75019
RE: Pinkerton Elementary School Addition
Dear Mr. Goram:
and ~,/~(~
On behalf of Coppell I.S.D., SHWC, Inc. requests a hearing of the Coppell City Council on a
variance for the above mentioned project.
Coppell I.S.D. would like to request a change from the present requirements of 6" thick con-
crete paving to 5" thick concrete paving in the parking and light traffic areas. All bus and serv-
ice drives will be constructed with 6" thick concrete paving. All concrete paving, whether 5" or
6", will be installed on lime stabilized sub base.
This request is being made based on the information provided by Maxim Engineers, whose soil
investigation indicates that a 4" thick concrete pavement section for the parking and light traffic
areas is sufficient for these selected areas. I have included the section of this soils report per-
taining to pavement recommendations for your review.
Coppeil I.S.D. applied for and was granted this very same request for the parking areas at Cop-
pell High School parking areas, Austin Elementary School and Mockingbird Elementary School.
I would appreciate your consideration of this request and would like to be considered for the
earliest possible date for the City Council's upcoming meeting.
Should you need any additional information please do not hesitate to call me. My telephone
number is 550-0700. Thank you for your assistance in this matter.
Sincerely,
SHWC, Inc.
Michael L. Elmore
Senior Associate
ME/kc
Enclosures
]2
It is also recommended that the utility ditches be
visually inspected during the excavation process to
ensure that undesirable fill that was not detected
by the test borings, does-not exist at the site.
This office should be notified immediately if any
such fill is detected.
The proposed additions should be structurally
independent of the existing structures.
At Grade Pavement Recommendations (Surface and Dri¥9~}.
Prior to beginning pavement construction, soils at the
natural ground surface in the proposed drive area
should be scarified and grubbed to a depth of at least
six (6) inches.
Organic materials and any vegetation should be removed
from the site. The scarified areas, along with areas
requiring additional fill, should then be recompacted
to a minimum of 95% of Standard Proctor Density as
defined by ASTM D 698 at a moisture content between
optimum and five (5) percent above the optimum moisture
value.
The following pavement sections are a minimum recom-
mended for the soil conditions existing on the site:
13
Areas of Light Vehicular Traffic
5.0 inches Portland Cement Concrete
(15 feet_Joint Spacing )*
6.0 inches Lime Stabilized Soils**
or
Areas of Liaht Channelzed Traffi~
6.0 inches Portland Cement Concrete
(15 feet Joint Spacing )*
6.0 inches Lime Stabilized Soils**
The light duty pavement is designed for 200 to 300
vehicles per day, two (2) to three (3) of which may be
heavy commercial trucks. The pavement section should
be redesigned and may differ from the aforementioned if
traffic loading, volume and other conditions exist
outside those previously mentioned.
MAXIM
*See guidelines for concrete parking areas in the
Appendix of this report.
**With the addition of five (5) percent of hydrated
lime by dry unit weight of soil.