Plures Intelligens Modicum Machinatorem
808 Gilman Street Berkeley, CA 94710 | 510-549-3300 | admin@bearinc.com
Dr. Glen Stevick, P.E. ext. 101 | Dr. Dave Rondinone, P.E. ext. 102 | Derek King, P.E. ext. 103 | Mingxi Zheng, P.E. ext. 106
Earthquake Engineering.
When the Golden Gate Bridge opened in 1937, it became an icon of engineering genius the world over. The structure’s five traffic lanes bridge a geographic strait from which the bridge takes its name. The Golden Gate Bridge main suspension span extends 4,200 feet. And the towers supporting the bridge's suspension cables narrow at the top from a larger base, emphasizing the tower’s 500-foot height.
Chief Engineer Joseph Strauss oversaw the overall design and construction of the project. Famed designer Leon Misseiff was the principal engineer who produced the basic structural design, introducing his "deflection theory," in which a thin, flexible roadway would flex in the wind, greatly reducing stress by transmitting forces via suspension cable to the bridge tower.
New understanding of engineering suggests that wind and earthquakes, however, can lead to an unexpected resonance mode that could cause the bridge to snap. When the Golden Gate Bridge District started a program to retrofit the Golden Gate bridge to better resist seismic events, the BEAR Engineering Team, headed by Founding Senior Mechanical Engineer, Dr. Glen Stevick, was asked to do the calculations for the disk that was used as a damping device (seen here). For this work, the project received the Outstanding Civil Engineering Achievement Award in 2007.