ATTAININg RETuRN ON INNOVATION
Cadre Design group, Inc.
sFoBB east span seismic safety project
completed in 1936, the San Francisco-oakland Bay
Bridge serves 280,000 vehicles per day. After the
1989 loma prieta earthquake caused a 250-ton
section of the upper deck to collapse, the california
Department of Transportation (cAl TrAnS)
decided to replace the east Span. cAl TrAnS
also designated the Bay Bridge as an emergency
lifeline route, making a seismic upgrade imperative.
cadre Design Group provided 3D integrated shop
drawings for all four east Span projects.
cadre was tasked with preparing 3D models of
various highly congested areas at each project site
for the sole purpose of identifying and resolving
conflicts. However, in every instance the scope
was expanded to allow the models to be used for
design optimization and construction methodology.
For example, on the Yerba Buena Island portion,
GeopAK resolved the complex geometry for
transitioning from Yerba Buena Island tunnels to the
self-anchored suspension span.
Using microStation and GeopAK to develop the
3D models allowed cadre to easily exchange
information with the client, designers, and
contractor; and seamlessly integrate all design
and construction disciplines. As a result of the
expanded use of 3D models on this $6 billion
program, cAl TrAnS saved several million dollars
and maintained the target completion date of 2013.