Parameters Influencing Seismic Resilience of Self-Centering Concrete Bridge Piers

This study evaluates the optimum combination of the parameters that affect the seismic behavior of self-centering concrete bridge piers. Finite element models of these bridge piers under cyclic loading are developed in this study and validated based on the available experimental data set in the literature. A factorial analysis is performed to understand the effects of various parameters on the strength loss of the low and high aspect ratio piers under monotonic lateral loading as demonstrated in past experimental program. The interaction among different parameters such as the pier aspect ratio, concrete strength, prestress force level, longitudinal steel ratio and thickness of the confining steel jacket was evaluated for 4% drift level and their contribution to the degradation of the pier strength has been determined. The results show that concrete strength, prestress force level, and steel jacket thickness affect seismic behavior for both low and high aspect ratio piers. Steel jacket thickness is found to be the most sensitive for strength loss of high aspect piers, and initial prestress force level is the most sensitive for low aspect piers. The longitudinal steel ratio of the piers does not have any effect on strength degradation. Based on factorial analysis, optimum design parameters and a set of regression equations are proposed for the strength degradation estimation. Optimum design parameters result in 3.68% strength reduction for high-aspect piers and no strength reduction for low-aspect piers. The proposed optimum pier design ensures minimum strength degradation and enhances seismic resilience in the self-centering concrete bridge piers.