Seismic design and performance of building structures with self-centering steel-concrete hybrid single-pier coupled walls

In response to the demand for seismic-resilient structures, various innovative solutions have emerged to reduce local damage and residual deformations, facilitating repair operations in the aftermath of high-intensity earthquakes. This paper examines the seismic performance of a steel-concrete hybrid wall system equipped with a self-centering solution to mitigate earthquake-induced residual deformations. The considered hybrid system includes a Reinforced Concrete (RC) shear wall with two steel side columns connected by coupling steel beams. In this study, a novel type of coupling beams featuring a friction-damped self-centering system is implemented. The system is referred to as Self-Centering Hybrid Single-Pier Coupled Wall (SC-SP-HCW) and aims to minimize damage and residual deformations after earthquakes, which in turn facilitates repairs and enhances seismic resilience. Unlike conventional self-centering coupling beams with post-tensioned tendons, the self-centering configuration in this system does not rely on a gap-opening mechanism at the wall-beam connection interface, eliminating frame expansion effects. The proposed self-centering devices can also be implemented as pre-assembled links, which facilitates installation and reduces uncertainties associated with the on-site post-tensioning procedure. The seismic performance of SC-SP-HCWs is investigated through nonlinear static and incremental dynamic analyses on case study SC-SP-HCWs designed as the lateral load-resisting systems of an eight-story building. The seismic response of the case study SC-SP-HCWs is investigated, considering both local and global engineering demand parameters (EDPs). The results demonstrate the ability of the SC-SP-HCWs to significantly reduce earthquake-induced residual deformations without exacerbating damage to structural elements typically observed in conventional coupled walls.