Calibration Factor for ASCE 41-17 Modeling Parameters for Stocky Rectangular RC Columns

Existing old reinforced concrete (RC) buildings could be vulnerable to large earthquake events. Most columns in such buildings have insufficient reinforcement details, which may experience failure during an early loading stage. The failure of columns may lead to partial or complete collapse of entire building systems. To prepare for an adequate retrofit plan for columns, it is necessary to simulate the cyclic behavior of columns using a numerical model with adequate values of constituent modeling parameters. The nonlinear component modeling parameters are specified in ASCE 41-17. However, the experiments on stocky RC columns suggest that ASCE 41-17 nonlinear component modeling parameters do not reflect the RC column behavior adequately. To accurately simulate the nonlinear load deformation responses of stocky RC columns with low span-to-depth ratio, this study proposes a calibration factor for ASCE 41-17 RC column modeling parameters. For this purpose, this study collected test data of 47 stocky column specimens. Based on the test data, empirical equations including the calibration factor for modeling parameters "a" and "b" in ASCE 41-17 were proposed. The accuracy of the proposed equation was verified by comparing the measured and calculated envelope curves.