A Study on Coupled Wall System with Post-tensioned Steel Truss Coupling Beams: Concept and Performance Evaluation

In order to improve the seismic behavior of coupled shear wall structures, a new type of post-tensioned steel truss coupling beam (PSTCB) is developed in this paper. The PSTCB is composed of chord members, two diagonal buckling-restrained energy dissipaters and diagonally placed post-tensioned tendons. The energy dissipaters are expected to serve as fuses and can be quickly repaired after earthquake. Furthermore, the residual drift of the coupling beam can be reduced by the application of post-tensioned tendons in the diagonal direction. In the PSTCB, the post-tensioned tendons are anchored at outer ends of the wall piers. According to the Chinese code, an 11-story coupled wall structure was designed and the numerical model was developed in PERFORM-3D software. The seismic behaviors of the hybrid coupled wall system with PSTCBs (HCW-P), the hybrid coupled wall system with replaceable steel truss coupling beams and concrete coupled wall system with reinforced concrete coupling beams were evaluated and compared under maximum considered earthquake. Results showed that the HCW-P can achieve excellent lateral strength, stiffness, and ductility as well as reduce the residual displacements of the structure after earthquake.