Use of Partially Prestressed Reinforced Concrete Columns to Reduce Post-Earthquake Residual Displacements of Bridges

To minimize residual displacements in reinforced concrete columns, a design is proposed whereby a longitudinal post-tensioning tendon replaces some of usual longitudinal mild reinforcing bars. The seismic performance of such partially prestressed, reinforced concrete columns is investigated through a series of earthquake simulator tests. The effects of unbonding of longitudinal mild reinforcement and providing a steel jacket are also investigated. The partially prestressed, reinforced concrete columns studied perform remarkably well under strong ground excitations. Very small permanent deformations are observed after the tests, especially when the longitudinal mild reinforcement is unbonded and a steel jacket is provided.