In Memphis, Tennessee, the Hernando DeSoto Bridge carries Interstate 40 (I-40) over the Mississippi River. The bridge also sits on the southeast edge of the New Madrid Seismic Zone, which is considered to be the highest earthquake risk in the U.S. apart from the West Coast. The fault itself runs approximately 193 km from Illinois to Arkansas, and the full seismic zone covers a much broader area. Recognizing the potential seismic danger, FHWA, Arkansas' State Highway and Transportation Department, and the Tennessee Department of Transportation joined forces to provide a seismic retrofit for the well-traveled bridge. The aim was to minimize the changes of potential closures that could affect I-40 in the event of an earthquake. This article details the performance goals, design features, retrofit design strategies, isolation bearings, and seismic monitoring of the bridge retrofit project.
Samenvatting