Since its completion the Bay Bridge has existed in the shadow of its famous
neighbor the Golden Gate Bridge; however, in 1989 it gained the public's
attention. In that year the Loma Prieta earthquake hit the San Francisco
area. Measuring 7.1 on the Richter scale, the quake forced the closing of
the Bay Bridge when a portion of the upper deck on the east crossing fell,
disrupting traffic for months.
Caltrans has begun to seismically retrofit the Bay Bridge beginning with
the eastern approaches in Oakland. This work involves driving new piles
to replace the original timber piles. Additional columns and bracings will
be added and the foundations enlarged. Work will continue through 2002 at
a cost of $1 billion to $1.3 billion.
In addition to the Bay Bridge, four other major bridges in the Bay area
are slated for seismic retrofit work. Work on the Golden Gate Bridge could
begin this fall. This retrofit will allow the bridge to withstand an earthquake
with the magnitude of 8.3 on the Richter scale. Completion of the project
is based on available federal funds.
The Benicia-Martinez Bridge, built in 1962, is scheduled for retrofit in
May 1997, and in 1998 a parallel span will be constructed to help carry
traffic on I-680 across the Suisun Bay. Work on the east span of the
nearby Carquinez Bridge also will begin in May 1997. The west span, built
in 1927, will be replaced at a cost of $300 million.
Caltrans plans to construct a new parallel span for the San Mateo-Hayward
Bridge in 1998, in addition to the retrofit of the existing 6.8-mile-long
bridge.
Construction work on the I-880 and I-92 interchange and the building of the Highway 238 bypass will improve access to the bridge. In 1997 retrofit work will begin on the Richmond-San Rafael Bridge, the 5.5-mile link between Contra Costa and Marin counties. A new, four-lane divided parkway in the city of Richmond, due for completion this summer, will improve access to the bridge from I-80 in the north.