Seismic performance of reinforced concrete moment resisting frames

Moment resisting frames (MRF) are typically classified as “ductile”, “nominally ductile”, and “GLD” (Gravity Load Designed). The seismic performance of these structures can be evaluated in terms of its lateral load resistance, distribution of interstory drift, and the sequence of yielding of the members. In this study a typical 5-story frame is designed as (a) ductile, (b) nominally ductile, (c) GLD, and (d) retrofitted GLD. This study presents an analytical approach for seismic assessment of RC frames using nonlinear time history analysis and push-over analysis. The analytical models are validated against available experimental results and used in a study to evaluate the seismic behavior of these 5-story frames. It is concluded that both the ductile and the nominally ductile frames behaved very well under the considered earthquake, while the seismic performance of the GLD structure was not satisfactory. After the damaged GLD frame was retrofitted the seismic performance was improved.