Analysis of residual displacement for reinforced concrete piers under pseudo-static load

In order to reveal the mechanism of residual deformation for reinforced concrete (RC) piers under pseudo-static load and propose a more accurate calculation method of residual displacement, with the fiber beam-column element, the calculation model of RC pier was established by OpenSees, and the influences of some parameters on ductility index of residual displacement were investigated, including axial load ratio, shear-span ratio, longitudinal reinforcement ratio, transverse reinforcement ratio, strength hardening coefficient of longitudinal reinforcement, ratio between longitudinal reinforcement yield strength and concrete compressive strength. The curve of residual displacement influence coefficient changing with a single parameter was fit by ductility index of residual displacement. On that basis, the calculation formula of residual displacement influence coefficient was established, and the accuracy test of this formula was performed by the comparing estimated value of the proposed formula with the pseudo-static test value. The results show that the estimated residual displacement by the proposed formula has a less than 10% deviation from experimental results, so the proposed formula can be used for preliminary estimate of residual displacement under pseudo-static load of RC piers designed by performance based seismic design method. ©, 2015, Huazhong University of Science and Technology. All right reserved.