Study on the seismic behavior of RC bridge piers under variable axial load

To study the seismic performance of RC bridge piers under variable axial force, six specimens are prepared, of which one was under constant axial load and the other five with different longitudinal reinforcement ratios, volumetric percentages of stirrups and shear span ratios, were subjected to variable axial force. The test results indicate that the variable axial force has apparent effect on the displacement, residual deformation, and the level of destruction of RC bridge piers. The fiber model was applied to simulate the piers under variable axial load and the theoretical results agree well with the experimental results. According to the performance-based seismic design, suggestions are proposed to consider varying axial load during design.