Seismic Performance of Steel Bridges during Last 50 Years and Lessons Learned

The talk will focus on the observed seismic performance of steel bridges during the major earthquakes over the last 50 years (Alaska 1964- Napa 2014). During the 1964 Alaska quake major steel truss spans collapsed indicated lack of sufficient length of bearing supports on the piers. The next major quake, the 1989 Loma Prieta earthquake caused the collapsed of a 50-ft segment of deck on top of a pier, while other steel bridges had minor damage to their connections. The 1994 Northridge earthquake caused damage to the connections of steel bridges but no collapse. The 1995 Kobe earthquake caused serious damage to some of the most modern long span bridges especially to their bearings and seismic energy dissipating devices with a few steel girder span and steel piers collapsing during this quake. During the 2014 Napa earthquake steel bridges performed well with minor damage. The possible causes of damage will be discussed with lessons learned from the study of performance of steel bridges to improve seismic design.

Speaker: Dr. Abolhassan Asteneh, UC Berkeley