Experimental and theoretical studies on the seismic performance of CFST battened built-up column piers

Abstract

The insufficiency of seismic performance data and the lack of seismic design provisions have affected the application and promotion of the CFST battened built-up column (CFST-BBC) pier in high-intensity areas. To understand the failure mechanism, the energy dissipation capacity, and the hysteretic behavior of the CFST-BBC pier, a total of seven test specimens subjected to lateral cyclic repeated loading were first tested. Meanwhile, a fiber-based finite element model (FFEM) was established by using OpenSees to simulate the seismic behavior of the CFST-BBC pier, and an extended parametric analysis was performed to clarify the impact of key parameters such as material strength, axial compression ratio and slenderness ratio on the seismic performance of the CFST-BBC pier. Finally, theoretical calculation methods for the lateral stiffness, lateral resisting strength and allowable deformation of the CFST-BBC pier were proposed and verified by comparing with experimental and analytical results. It is proved that the calculation results obtained by the proposed methods can effectively reflect the intrinsic characteristics of the seismic performance of the CFST-BBC pier and meet the accuracy requirements of practical engineering applications.