Cantilever truss bridge
|Function / usage:||
Railroad (railway) bridge
Motorway bridge / freeway bridge
San Francisco, San Francisco County, California, USA
Oakland, Alameda County, California, USA
San Francisco-Oakland Bay Bridge (East) (2013)
Yerba Buena Tunnel (1936)
|Coordinates:||37° 48' 57" N 122° 21' 16" W|
|main span||427 m|
|12 November 1936||
Opened to traffic.
An inspection reveals cracking in a critical eyebar component of the main span. Found in one of eight bars sharing the same load, the crack was not present two years earlier. The bridge is closed and emergency repairs are carried out.
|27 October 2009||
During the evening commute, a saddle, crossbars, and two tension rods (parts of the emergency repair during the previous month) weighing over 2.25 tons collapses onto the deck. The failure of the repair was caused by two design defects: first, the tie rods closely fit the holes in the cross pieces over the saddles and second, wind caused vibrations in the rods, which in turn caused wear and bending at the through holes, eventually causing a rod fracture. The catastrophic dropping of the cross pieces was caused by a lack of structural attachment to the saddle, being retained only by tack welds, friction and the tension of the tie rods. The rework of the design includes six significant modifications:
|2 November 2009||
The bridge is re-opened after emergency repairs.
Relevant Web Sites
- Bay Bridge inspection reveals eyebar crack. In: Bridge Update, n. 86 (September 2009), pp. 1.
- Bay Bridge under close watch after eyebar failure. In: Bridge Design & Engineering, v. 15, n. 57 (4th Quarter 2009), pp. 7.
- Die Geschichte der San Francisco-Oakland Bay Bridge. In: Bautechnik, v. 81, n. 4 (April 2004), pp. 237-250. (2004):
- Les grands ponts du monde: Hors d'Europe. Brissaud, Poitiers (France), pp. 144-145. (1990):
- Les grands ponts en construction à San-Francisco. In: Ossature métallique, v. 3 (November 1934), pp. 543-560.
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