The City’s main potable water
supply – an old 20-inch cast iron
pipe – was relocated outside
the pavement area. The pipe
provides water to more than half
of the City’s 24,000 people. The
City’s goal was no interruption
of water service for residents
and businesses during the
project, Schurman said. Ayres
Associates’ custom-designed
thrust blocks and anchors allowed
for the process to be completed
smoothly.
Schurman said he is amazed the
utility portion of the project went
as well as it did.
“In preparation for the project,
we did a lot of study on the
water line itself – testing valves,
16│ TRENDS
determining which ones worked,
which ones didn’t,” he said. “We
went through the whole exercise
in case there was any kind of
failure. Our staff was trained in
what to do. Failure of a 20-inch
water line would have been a big
deal.”
The corridor required miles of
retaining walls that included
cast-in-place, concrete sheet pile,
steel sheet pile, and mechanically
stabilized earth-type, said Hisham
Sunna, who oversaw structural
engineering for Ayres Associates.
Groundwater elevations and
lack of available right-of-way
required various types of walls
to be used depending on site
conditions. Many walls were
designed so the contractor could