ABSTRACT
AASHTO provides two publications for the seismic design of steel bridges: the LRFD Bridge Design Specications (AASHTO, 2012) and the Guide Specications for LRFD Seismic Bridge Design (AASHTO, 2011). e seismic provisions in the LRFD Bridge Design Specications, hereaer referred to as the LRFD Specications, are based on the recommended guidelines in the ATC-6 report published in 1981 (ATC, 1981). e ATC study was initiated by the aermath of the 1971 San Fernando earthquake that caused signicant damages to reinforced concrete bridges. Since bridge substructures are typically made of reinforced concrete in high seismic regions in North America, the LRFD Specications have been mainly focused on reinforced concrete bridges and the coverage of steel bridges is limited.
