Residual Displacements of Concrete Bridge Piers Subjected to Near Field Earthquakes

Abstract

This research sought a solution to reduce residual displacements of reinforced concrete (RC) bridge piers after earthquake excitations. Because prestressed concrete (PC) members normally show recovery from elastic stiffness during unloading, this work proposes the possibility of using PC to minimize the residual displacements. However, prestressed members will have reduced ductility. Therefore, a new technique that employs partially prestressed concrete (PPC) for the bridge piers is examined in order to take advantage of the positive features of both RC and PC. An extensive experimental program, using reversed cyclic loading and pseudo-dynamic tests, was conducted. The experimental variables included the relative ratio of prestressing tendons to non-prestressing reinforcement and flexural to shear capacities. Based on test results, the inelastic response behavior of PPC bridge piers was substantially clarified. The advantages and disadvantages of their use were clearly identified. The study revealed that employing prestressing tendons in RC bridge piers could result in subsequent reductions of residual displacements, restrain associated cracking, and enhanced concrete shear strength after earthquake excitations.