Seismic response assessment of a hybrid coupled wall structure with novel self-centering steel truss coupling beams

In this paper, a novel self-centering buckling-restrained energy dissipater (SC-BRED) with pretensioned basalt fiber-reinforced polymer composite tendons is firstly introduced. Furthermore, based on the SC-BREDs, a self-centering steel truss coupling beam (SCCB) is proposed to improve the seismic resilience of coupled wall structures. The SCCB consists of chord members at the top and bottom, respectively, and two SC-BREDs are employed in the diagonal direction. The chords are connected to the adjacent wall piers by hinge joint and all inelastic deformations are concentrated on the SC-BREDs, which can be easily installed and quickly repaired for post-earthquake. This paper mainly focused on the numerical and theoretical analyses of the SCCB, and nonlinear numerical models are developed in PERFORM-3D. An 11-story prototype structure was designed per Chinese code. The seismic behaviors of the hybrid coupled wall system with SCCBs (HCW-SC), the hybrid coupled wall system with steel truss coupling beams (without pretensioned tendons), and the reinforced concrete coupled wall system with RC coupling beams were evaluated and compared under maximum considered earthquake. Results showed that the HCW-SC can achieve excellent lateral strength, stiffness, and ductility as well as reduce the residual displacements of the structure after earthquake.