On Estimation of Seismic Residual Displacements in Reinforced Concrete Single-Column Bridges Through Force–Displacement Method

Abstract

Bridges normally undergo nonlinear deformations during a near-field strong ground motion resulting in a critical deviation of their columns from the plumb state due to considerable residual deformations. The conventional hysteresis models formulated for typical concrete columns are normally used for this purpose which most of times fail to correctly predict the residual deformations occurred as a result of a one-sided or directivity pulse excitation. The present research aims at development of a peak-oriented hysteresis model being able to regenerate residual deformations more reasonable compared with the conventional hysteresis models. This multi-linear peak-oriented model considers strength deterioration in each half cycle in addition to stiffness degradations in unloading cycles. Yielding points differ in both positive and negative sides of the hysteresis model that enables us to define a different elastic stiffness of both sides in asymmetric concrete sections. This work also compares the obtained results to the conventional hysteresis models, namely bilinear, Clough, Q-Hyst, Takeda, and Bouc-Wen in terms of prediction of residual nonlinear deformations in cyclic analysis or dynamic analysis of reinforced concrete single-column bridge piers. The obtained results prove higher relative accuracy of the proposed model.