The San Francisco-Oakland Bay Bridge was constructed at the same time as the Golden Gate Bridge and opened for traffic in 1936. In October 17, 1989, an earthquake measuring 7.1 on the Richter scale severely damaged the double decker truss structure east of Yerba Buena Island, knocking down a portion of the upper deck.
The new structure of the bridge is designed to meet current seismic codes as well as other codes pertaining to roadway shoulders, lane widths, stopping sight distances and other factors to substantially improve public safety. The Skyway portion of the bridge connects the Oakland Touchdown structure to the Suspension Section just east of Yerba Buena Island. It is the longest component of the East span and where Sika products are currently being utilized by the joint venture partnership builder, KFM (Kiewit Pacific, FCI Constructors and Manson Construction Company).
The Skyway section of the new East span is the largest contract ever awarded by Caltrans at $1.04B. It consists of a westbound and eastbound deck over 1 mile (1.61 km) long. The two roadways each have five lanes of traffic, emergency shoulders and 15 feet (4.6 m) wide pedestrian/bike paths. There are 452 precast sections. Each segment was cast in Stockton, California (approximately 100 miles (161 km) form the project) then shipped down on barges to the site. Prior to shipping, the transverse cables were tensioned and the ducts grouted with SikaGrout®-300 PT.
More than 16’000 gallons (approx. 60’000 Liter ~120 tons) of Sikadur®-31 SBA were “smeared” to each side of each precast segment prior to final placement and tensioning. Sikadur®-31 SBA serves as a lubricant to allow for adjusting the placement of the segments during erection and as waterproofing for joints after placement of the segments and tensioning of the cables.
Over 200’000 bags of SikaGrout®-300 PT where supplied to fill the ducts containing the post-tensioned cables. The grout provides additional protection to the steel cables as well as enhanced bonding of the cables to the duct and precast concrete segment.
CalTrans (California Department of Transportation)
KFM (Kiewit Pacific, FCI Constructors and Manson Construction Company) – Joint Venture