SHAKE TABLE TESTING OF FLEXURE DOMINATED REINFORCED CONCRETE BRIDGE COLUMNS

This study focused on the performance of circular reinforced concrete bridge columns that were subjected to real time earthquake excitation. An inertial loading system for testing single-degree-of-freedom models on a shake table system was developed for the study. A computer program was developed to predict the non-linear response of the columns under earthquake loading. Two columns were tested , both with flexural dominated failure modes with identical longitudinal steel and transverse confinement ratios. Axial load and column diameter and height were the same for both columns. Two different earthquake loading scenarios were used to compare the effect of load history on the performance of the two columns. The RC-SHAKE computer program adequately predicted column deflections. It was shown that strain rate can have a significant effect on column capacity for dynamic loading versus slow-cycle testing.