Design consideration for improving seismic performance of RC structural wall under extreme conditions

Reinforced concrete (RC) structural walls are commonly used as lateral-load resisting systems for mid- and high-rise buildings. Due to their relatively large stiffness and high strength, there is a consensus in the earthquake engineering community that well-designed RC walls exhibit superior performance under strong earthquakes. The expected energy dissipation mechanism of cantilever walls is flexural yielding concentrated at the bottom of the wall (i.e., the plastic hinge region). However, the bottom walls of high-rise buildings usually experience complex force and moment combinations, making them prone to considerable damage under extreme conditions, which can cause irreparable failure and interruption of functionality. Therefore, improving the seismic performance of bottom RC walls is one of the critical issues for high-rise buildings in earthquake-prone regions. First, the current design practices of axial compressive behavior, global instability, and minimum reinforcement ratio for RC walls were summarized. Design considerations for improving the seismic performance of RC walls under extreme conditions were discussed. Subsequently, three typical failure modes (axial compressive failure, global instability, and shear failure) of the RC wall and the improvement measures were validated through finite element analyses. Numerical results demonstrate that the embedded steel plate can efficiently improve the performance of walls under high axial compressive force and large shear force conditions, providing one of the successful solutions for improving seismic resilience of RC walls.