Maximum displacement profiles of reinforced concrete frames

Abstract

New expressions to estimate maximum seismic lateral displacement profiles of regular plane RC frames at three different damage levels, slight, moderate, and severe damage, are developed in this study for the purpose of displacement-based seismic design. These expressions relating the maximum floor displacements with the maximum inter-story drift ratio over the height and the main structural characteristic of the frame are based on statistical analysis of the results of hundreds of nonlinear time history analysis conducted on a set of 25 plane RC frames subjected to a set of 16 physical accelerograms containing different frequency spectrum. The fundamental period, column-to-beam strength ratio, and damage level were identified as the main structural characteristic having significant effects on the maximum displacement profiles. A case study was conducted on a 12-story RC frame model tested on the shaking table before and shows good agreement between the estimated profiles and test results. The developed profiles are independent of sections and reinforcement of the structure so that they can be used as the starting design variables in displacement-based seismic design.