Experimental Study of Seismic Performance of an Innovative Low-Damage Self-Centering Composite Steel Plate Shear Wall

Composite shear walls are widely used to resist the lateral load in high rise-buildings nowadays; however, prior experimental tests have shown high damages and residual drifts at the plastic zone region. At present time, designing resilient buildings with low or no damage is one of main goal in performance-based seismic design of structures. In current research, a new design of an innovative low damage self-centering composite steel plate shear wall (SC-C-SPSW) equipped with unbonded posttension tendons (UPTs) is proposed to control the damage and the residual drift under seismic loading. To this end, five specimens including two composite steel plate shear walls (C-SPSW) and three SC-C-SPSWs were tested under gravity and reverse cyclic loading. The SC-C-SPSWs were detached using a pair of steel plates placed symmetrically under the wall boundary elements in order to form the bottom gaps with the foundation. The gap length, steel plate dimensions, and the initial prestressing on UPTs were considered as experimental parameters in this study. The construction details and the seismic performance including failure modes, damage progression, hysteretic response, and energy dissipation are presented in detail. The experimental results indicated that SC-C-SPSWs have excellent behavior in term of lateral strength and ductility and experienced low damage levels in comparison with C-SPSWs. The SC-C-SPSW walls experienced a large lateral displacement before initiation of the strength degradation, and the residual drifts were much smaller in comparison with C-SPSWs.