February 03, 2014
The American Bridge/Fluor Joint Venture (ABFJV) was the general contractor for the new East Bay Bridge mainspan of the San Francisco /Oakland Bay Bridge. This project includes the construction of a new 624m (2,049’) two-span, self-anchored suspension bridge. The mainspan is 565m (1,854’), and the structure also incorporates a 49.4m (162’) cantilevered span and a 10m (33’) anchor span. The steel tower is 160m (525’) tall, composed of four legs strutted together. The deck is 78m (256’) wide. The 1,400m (4,600’) long, 800mm (31.5”) diameter main cable is continuous from east anchorage to tower top saddle to northwest deviation saddle to center jacking saddle to southwest deviation saddle back to tower top saddle and back down to southwest deck anchorage.
The total weight of permanent structural steel is 51,772mt. With the exception of the caps for the east and west piers, this entire contract is comprised of structural steel fabrication and erection. Over a dozen fabricators supplied product for the bridge, overseen by ABF quality control teams and scheduled and coordinated by ABF engineers. The deck is composed of twin steel boxes of 28m each, strutted together for an out-to-out width of 78m (256’) . In addition, there is a 5m (17’) wide bike path that is cantilevered from one of the 28m boxes. The deck panels are of varying lengths and weigh between 500 and 1,550mt each. The total structural steel weight of the deck is 30,907mt.
The cable has a weight of 4,800mt, and the hanger ropes weigh an additional 650mt. The cable is made up of 137 prefabricated parallel wire strands (PPWS) with 127 wires per strand compacted and wrapped with "s" wire. The cables are anchored in the deck of the structure, making it self-anchored (no gravity anchors). As a result, the orthotropic box girder deck structure was constructed on, and remained supported by a temporary falsework bridge until the main and hanger cables were erected. At that point the entire 31,000mt load of the deck superstructure was transferred from the falsework to the hanger and main cable in a carefully engineered and precisely sequenced operation.
The project completed a major milestone on Sept 2, 2013 when it opened to traffic, on schedule. Final completion was achieved September 24, 2015.