Bay Bridge Info

The design, engineering and construction teams have met the challenge of making the Bay Bridge seismically resilient with cutting-edge innovations and enhancements—some never before used in bridge building—that are transforming the bridge into a state-of-the-art engineering icon.

 

The first section crews completed was the Skyway, which also includes some of the most amazing seismic innovations. To build the Skyway’s foundations, 160 rebar and concrete-filled steel piles were driven up to 300 feet below the water’s surface to anchor into stable soils. The piles were driven into the soil at an angle, through a process called “battering,” to create greater stability. This method has been used to create secure foundations for oil rigs for more than two decades, but has not been used in bridge construction of this scale.

 

Hinge pipe beams, which look like massive metal dowels, are another amazing state-of-the-art innovation, as they are designed to move within their sleeves during expansion or contraction of the decks during minor events, such as changes in temperature. Twenty of these 60-foot-long devices were placed between deck sections as well as between where the Skyway and SAS meet. The beams are designed to absorb the energy of an earthquake by deforming in their middle or “fuse” section. This will minimize the damage to the bridge’s main structure. The damaged fuses can then be removed and replaced. Hinge pipe beams are also found at the western piers where the SAS connects to the YBITS.