The bridge structures are to be retrofitted to sustain a “maximum credible earthquake” with limited damage while maintaining the bridge’s historic and aesthetic values. In addition to the seismic retrofit of the suspension span, the contract also includes seismic retrofit of the Lincoln Boulevard and Toll Plaza undercrossings. HDR will also provide structural design and detail of the wind retrofit and structural hardening of the bridge determined by the Golden Gate Bridge Highway and Transportation District.
The Golden Gate Bridge is a vital transportation link to the San Francisco Bay area, serving more than 40 million vehicles a year. After the 1989 Loma Prieta earthquake, officials developed a four-phase seismic retrofit plan (Phase I, II, IIIA and IIIB). HDR designed the Phase IIIA retrofit work and is currently providing design support services during construction on Phase IIIA – North Anchorage Housing and North Pylon. Construction for the Phase IIIA project is under way, and HDR’s design work on Phase IIIB—which involves the suspension span—also is under way.
