Seismic performance and mechanical mechanism analysis of embedded optimized steel plate-reinforced concrete composite shear wall under multi-dimensional loading

To comprehensively study the seismic performance of shear walls under multi-dimensional loading mode and enhance the seismic performance of the traditional shear wall, a novel type of embedded optimized steel plate-reinforced concrete composite shear wall (EOSP-RCCCSW) is proposed. Nine typical shear wall specimens are designed and subjected to quasi-static loading tests. By comparing failure modes, hysteresis curves, skeleton curves, and ductility of two types of shear wall under multi-dimensional loading condition, the seismic behavior of shear walls and the improved performance of embedded steel plates are investigated. At the component deformation level, the calculation equations for the bearing capacity of both shear wall types under out-of-plane loading condition and oblique loading condition are developed according to current standards. Based on finite element software and calibrated tests, the single main shock and the main-aftershock sequence time history analysis are performed on two structures with few shear walls in one direction. The damage levels of the steel-concrete frame-shear system and the system with embedded optimized steel plates are evaluated and compared based on story drift and rotation. The results indicate that the embedded optimized steel plate-reinforced concrete composite shear wall structure can exhibit higher bearing capacity, superior energy dissipation under various loading angles, and greater lateral stiffness. Significant differences are observed in the seismic performance of shear walls under multi-dimensional loading condition, underlining the importance of addressing out-of-plane loading condition and oblique loading condition. The theoretical equations for component bearing capacity provide precise predictions for yield load, yield displacement, peak load, and peak displacement of both shear wall types. Compared to the traditional frame-shear system, the system with EOSP-RCCCSWs demonstrates excellent performance in the in-plane direction and the out-of-plane direction under main-aftershock sequences.