INNOVATION IN BRIDgES
orwell Bridge Bearing replacements
Suffolk, united kingdom
opened in 1982, orwell Bridge is a 1,287-meter-long, 18-span structure carrying
the A14 Ipswich Southern Bypass over the river orwell estuary. The structure
consists of two independent, post-tensioned reinforced concrete box girders.
Atkins began managing the bridge in 2001 and has since performed various
works, including design of replacements for bearings that threatened the
structural integrity of the deck and piers.
Upon inspection and monitoring, Atkins quickly developed an interim solution
and then produced an optimal design for replacement bearings on the south
box and north deck. A 3D model of the approach viaducts created in rm Bridge
was used to evaluate options for jacking loads at numerous locations, check
structural adequacy at various replacement stages, and determine the effects
of pre-stressing, losses, and applied loadings.
Cadre Design group, Inc.
sFoBB east span seismic safety project
San Francisco-Oakland, California, united States
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
cadre Design Group provided 3D integrated shop drawings for all four east Span
projects. 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.