A Simplified Approach to Investigate the Seismic Ductility Demand of Shear-Critical Reinforced Concrete Columns Based on Experimental Calibration

A simplified approach is proposed to investigate the seismic ductility demand of shear-critical reinforced concrete (RC) columns based on experimental calibration. Incorporating with the Bouc-Wen-Baber-Noori (BWBN) model, the governing equation of the equivalent single-degree-of-freedom (SDOF) system is first presented to describe the typical hysteresis characteristics, where the relationship between the inelastic restoring force and translational displacement is calibrated by comparing with the experimental data of shear-critical RC columns under quasi-static cyclic testing. Based on the developed governing equation, the strength reduction approach is further implemented to estimate the seismic ductility demand of shear-critical RC columns by establishing the constant strength-ductility demand spectral (CSDDS) method. Finally, an empirical expression is regressed to predict the mean and standard deviation of seismic ductility demand of shear-critical RC columns. This study verifies the feasibility of the proposed approach to assess the seismic ductility demand of shear-critical RC columns. The presented idealized SDOF system can simplify the establishment of CSDDS method. The lognormal assumption cannot well describe the probabilistic characteristics of seismic ductility demand if all the uncertainties in model parameters and earthquakes are considered. The developed empirical expression is applicable to investigate the probabilistic seismic risk of shear-critical RC columns under different earthquake excitations.

Automated summary

A simplified approach is proposed to investigate the seismic ductility demand of shear-critical RC columns based on experimental calibration. The method includes establishing a governing equation, implementing a strength reduction approach, and regressing an empirical expression to predict seismic ductility demand. This study verifies the feasibility of the proposed approach and highlights the limitations of lognormal assumption in describing probabilistic characteristics of seismic ductility demand.