When the magnitude 6.9 Loma Prieta earthquake hit on October 17, 1989, a 50-foot section of San Francisco Bay Bridge collapsed onto the deck below.
Almost a decade later, when a design concept was approved, Caltrans selected Moffatt & Nichol in a joint venture to design the new San Francisco-Oakland Bay Bridge East Span. In addition to designing the bridge foundations, the Moffatt & Nichol was responsible for scour and vessel collision analyses. Seismic design improvements made after the Loma Prieta earthquake led to the extensive seismic retrofit of California bridges. Moffatt & Nichol participated in the development of design criteria.
