Precast Segmental Seismic Retrofit for the San Mateo Hayward Bridge

The retrofit of the San Mateo - Hayward Bay Bridge is part of the California Department of Transportationʹs (Caltrans) effort to retrofit the toll bridges in the state of California. As part of this program, the use of precast segmental construction techniques in the San Mateo - Hayward Bay Bridge retrofit project resulted in a constructable and durable retrofit for the rectangular foundations. The $102 million construction package included the seismic retrofit of 20 of these rectangular piers. This article provides an overview of the project design and construction phases. Precasting of the frames was performed on barges that were towed to the site and the frames were assembled and placed around the footings. Arms on the frames reached out to 8 to 12 ft (2.4 to 3.6 m) diameter piles driven through the bay mud to firmer soils so the system limited the excessive transverse deflections that would occur in a severe earthquake.