Seismic performance of eccentrically-compressed steel pier under multi-directional earthquake loads

In this article, the seismic performance of box-shaped steel piers embedded with energy-dissipating shells under a multi-directional seismic load is investigated. A finite element(FE) model was accurately established and verified by the quasi-static test results. A parametric analysis of the hysteretic behaviour of a novel box-shaped steel pier under eccentric pressure was carried out on this basis. We discussed the influence of the eccentricity, axial compression ratio, thickness of embedded shell, ratio of slenderness, spacing of transverse stiffening ribs on the embedded shell, and width-to-thickness ratio of wallboard on the anti-seismic performance of a novel box-shaped steel bridge pier. The results revealed that the load carrying capacity and ductility coefficient of the specimen are substantially influenced by the eccentricity, variation in the axial compression ratio, and slenderness ratio. The specimen′s plastic energy dissipation capacity can be effectively improved by increasing the thickness of the embedded shell. The spacing of the transverse stiffening ribs only marginally affects seismic performance. In addition, the width-to-thickness ratio of the wallboard exerts a more considerable influence on the deformability of the square-section specimen. Finally, a formula for calculating the bearing capacity of the novel box-shaped steel piers under cyclic loading is proposed.