A Comparison Study of Different Resisting Systems in Seismic Design of Highway Bridges Using Proposed NCHRP Provisions

Abstract

The Applied Technology Council (ATC), in a joint venture with the Multidisciplin ary Center for Earthquake Engineering Research (MCEER), has recently developed Comprehensive Specifications for the Seismic Design of Highway Bridges (National Cooperative Highway Research Program, NCHRP Project 12-49). The American Association of State Highway and Transportation Officials (AASHTO) is considering these recommended specifications for possible incorporation into the future AASHTO Load and Resistance Factor Design Specifications. The primary objective of NCHRP Project 12-49 was to develop seismic design provisions that reflect the latest research findings, design philosophies, and design approaches (ATC 2002). In this study, the substructures of two existing Missouri bridges with Seismic Performance Category of “C” and “D” were redesigned according to the proposed NCHRP provisions. These bridges have different resisting systems; in one bridge abutments contribute in lateral resisting system and in the second bridge, only the intermediate bent resist against earthquake forces. The design res ults were compared for these bridges.