A Rational Approach for Determining Response Modification Factors for Seismic Design of Buildings Using Current Code Provisions

摘要

A short review of response modification factors currently found in code design provisions for seismic design of buildings is given. A proposal for a new, rational procedure for determining R factors is presented. It requires both experimental and analyses for implementation. It is based on a probabilistic foundation developed for the SAC Phase 2 project. The target threshold is to provide a 90% confidence level for satisfying the Collapse Prevention performance objective for an earthquake with a 2,475-year return period. Adoption of this procedure would result in a uniform level of safety against collapse over all materials and building systems. The method is applied to steel moment-resisting frame buildings as an example.