EARTHQUAKE-RESISTANT BRIDGES- FROM FOUNDATION TO SUPERSTRUCTURE

This article presents an overview of three studies recently completed at the University of Nevada, Reno. Based on the results of a field vibration testing of a bridge the adequacy of existing methods to determine footing stiffness was evaluated. The soil shear modulus was found be the most critical parameter. A new expression for design of confinement steel in rectangular columns as a function of a target displacement ductility was proposed. An evaluation of design methods for seismic restrainers revealed that a simple method such as that in AASHTO is sufficient for common bridges.