A Study of Reliability-Based Criteria for Seismic Design of Reinforced Concrete Frame Buildings

Keywords: Design Criteria, Moment Resisting Frames, Reinforced Concrete Buildings, Reliability Based Design, and Limit States.

Abstract: A reliability-based criteria for the seismic design of reinforced concrete, moment-resisting frame buildings is presented. Criteria are developed in the LRFD format by considering structural strength explicitly and ductility implicitly. The design criteria are established on the seismic performance of the entire frame system. The collapse limit state employed herein is determined by the flexural failure mechanism of a structural system rather than the failure of structural members. Acceptable risk levels for various categories of buildings are investigated, and seismic load factors for ordinary buildings in various seismic zones of the U.S. are determined. In low seismicity zones, frame structures designed only for dead and live loads, and detailed as an IMR frame as specified by ACI 318-89, provide enough seismic resistance for ordinary and high risk buildings. For essential buildings, the seismic design requires use of both a seismic load factor and an importance factor of 1.0.