Using Metallic Dampers to Improve Seismic Performance of Soft-Story RC Frames: Experimental and Numerical Study

Abstract

The poor seismic response of gravityload-designed reinforced concrete (RC) frames with a soft story can be effectively controlled by using metallic dampers as passive energy dissipation devices. However, the absence of adequate large-scale test results and numerical tools for the accurate prediction of the seismic response of strengthened RC frames impedes their application in construction practice. This study presents a strengthening technique for the RC frame with a soft story using combined metallic yielding devices. Pseudodynamic testing of a two-story large-scale test specimen has been conducted to investigate its seismic response under varying amplitudes of a selected ground motion. A quasistatic cyclic test has been conducted to evaluate the collapse resistance of the strengthened specimen. In addition, a numerical model using computer software OpenSees has been developed to predict the seismic response of the strengthened RC frame. Both cyclic pushover and nonlinear dynamic analyses have been conducted to predict the seismic response and the collapse resistance of the strengthened specimen. The results of the numerical study matched reasonably well with the experimental findings.