ST8201-CS 890929GINN, INC.
CONSULTING ENGINEERS
September 29, 1989
Mr. Scott Balch, P.E.
L. H. Lacy Co.
P.O. Box 541297
Dallas, TX 75354-1297
Re:
Denton Tap Road Improvements from BE Road to
Denton Creek - Concrete Riprap Failure at the Grapevine
Creek Bridge
Dear Mr. Balch:
We have reviewed your letter of September 12, 1989 regarding the
subject captioned above. Having conferred with our Structural
Engineering Sub-Consultant, Reedcon, Inc., we maintain our
previously stated position as noted-in our July 6, 1989 letter.
The failed portions of the concrete riprap are to be removed and
replaced at the Contractor's expense as soon as possible. Prior
to reconstructing the failed portions, however, we require that
the depth and condition of the toe walls be verified by our
representative. Should there be evidence of rotation, improper
depth, or any other defects, the toe wall section shall also be
replaced.
It is still our intention to test the concrete riprap adjacent to
the failures, possibly by nondestructive means, to determine the
location and depth of reinforcing steel, thickness of concrete,
and the presence of voids in the slope immediately beneath the
riprap. Deficient areas discovered shall be replaced at the
Contractor's expense. The foregoing testing may also be
conducted on the other concrete riprap placed on this as well as
the adjacent project with the same stipulations as mentioned in
our July 6, 1989 letter in the third paragraph of the last page.
The costs of all re-examination, including testing and analysis
will be borne by the Contractor if the work is found to be
defective. If the work is found to be in compliance with the
Drawings and Specifications, the Owner will bear the costs of the
re-examination, testing and analysis.
Please proceed with the removal and replacement of the failed
concrete riprap as soon as possible. Call me if you have any
questions.
Sincerely,
Karlsruher, P.E.
Project Engineer
cc:
Stan Reed, P.E.
H. Wayne Ginn, P.E.
Randy Fleming
File 378
17103 Preston Road · Suite 100 · LB 118 · Dallas, Texas 75248 · .Phone 214/248-4900