November/December 2006
Merit Awards:
Caltrans Wins Demolition “Super Bowl”

A careful balance is maintained between creation and destruction as the new
approach takes shape just a few feet from homes and offices in downtown
San Francisco. (Photo: John Huseby, Caltrans)
For Caltrans to replace a one-mile stretch of freeway is not
a big deal. But when the freeway is located in the middle of
densely populated San Francisco, connects to the San
Francisco-Oakland Bay Bridge, has three on/off ramps and carries
260,000-plus vehicles a day, the project takes on another dimension.
The Bay Bridge West Approach seismic
retrofit is part of the overall Bay Bridge Seismic Safety Project
and one of the most complex and daunting projects in Caltrans’ history.
The entire one-mile stretch, bounded by Fifth Street and the
bridge anchorage on Beale Street, is in the process of being
completely torn down and replaced. The work must be done with
minimal disruption of heavy traffic and within inches or feet
of apartment buildings and offices.
The six-year project, scheduled
from 2003 to 2009, consists of a series of elaborately planned
demolition and construction projects. Called “retrofit
by replacement,” the
work entails building a temporary structure, rerouting vehicles
to it, demolishing the old structure, and beginning work on
the new one. When the new structure is built, vehicles are
rerouted again, and the temporary structure ultimately demolished.
“It
is a 10,000-piece puzzle,” said West Approach
Project Manager Ken Terpstra, “and requires a unique
combination of design, structural, construction and traffic
engineers to put it all together.”
The greatest challenge
of the entire project occurred on Labor Day weekend 2006, when
Caltrans closed the eastbound Bay Bridge for 77 hours in order
to demolish 1,000 feet of the upper deck bridge approach and
remove 10,000 cubic yards of concrete.
“There was a huge
amount of planning,” said Construction
Manager Dennis Turchon. “We had to sell the concept (of
the Labor Day weekend closure) to the governor, the Legislature,
the CHP, the city and county of San Francisco, and many other
decision-makers. We had to know if BART could run 24 hours,
if ferry service could be expanded and whether the contractor
could do the job in one weekend. This was the Super Bowl of
demolitions.”
“It was a tremendous PR risk if we
didn’t succeed,” added Caltrans Public Information
Officer Bart Ney. “There was no plan to follow. So we
developed one. First, we showed the media what we were going
to do, which made their jaws drop. Second, we went door-to-door
with flyers for the quarter-million people who live and work
in the South of Market neighborhood. We also visited virtually
every Bay Area city to let them know the artery wouldn’t
be available over Labor Day weekend. We had to get the message
out every way possible.”
At 4:23 a.m. the Tuesday after
Labor Day, the first cars came through. “We were 37 minutes
early, and we had won the Super Bowl,” Turchon said.
— Marjorie
Blackwell
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