A Flexure-Shear Coupling Fiber-Section Model for the Cyclic Behavior of R/C Rectangular Hollow Section Bridge Piers

Abstract

Reinforced concrete (R/C) bridge pier with hollow section may undergo strongly nonlinear responses when subjecting severe earthquakes. The pier may perform flexure-shear coupling behavior, especially for the thin wall of the hollow section. Some simulation models accounting flexure-axial coupled effects were proposed, however, few simulation model is proposed for R/C hollow section bridge piers mainly impacted by the flexure-shear coupling. In this paper a beam-column element accounting for flexure-shear effect is presented. The mathematical theory for this element is flexibility-based formulation, and the section constructed by fibers can be treated as any kind of bi-axial materials. The cyclic soften membrane model (CSMM) constitutive relationship for plane bi-axial R/C components is used in the determination of the nonlinear behavior. Two cyclic pushover experiments were carried on scaled hollow section piers. The results deduced from the numerical model is compared with the experiment result. This fiber-based model provides sufficient accuracy and computational efficiency. The model has been implemented into the finite element program, OpenSees. And further researches will focus on the flexure-shear induced damage and collapse for bridge structures.