An efficient method for optimizing the seismic resistance of reinforced concrete frame structures

Abstract

A practical and efficient optimization procedure for designing reinforced concrete frame structures with improved resistance to seismic loading was developed. The design methodology used the optimality criteria method in an iterative analysis-and-redesign scheme. A damage ratio–based procedure was proposed by employing the inelastic component rotations from nonlinear dynamic analysis to strengthen the severely damaged components in each iteration. The optimization approach is intuitive, simple, and easy to apply, since only analysis tools are required. The approach was applied to optimize the seismic response of two prototype frames, and sensitivity analysis established the relationship between seismic performance and the additional material cost of strengthening. The proposed method can substantially reduce the maximum interstory drift for a slight increase of material cost, indicating that the proposed method is a feasible design procedure for improving the earthquake resistance of reinforced concrete frame structures. Also, the procedure can deal with the cases of single and multiple ground motions. The effectiveness of the proposed method was also verified through extensive time-history analyses.