Seismic Floor Acceleration Demands of Self‐Centering Wall Systems

ABSTRACT Self‐centering wall (SCW) structures may generate floor acceleration demands substantially different from those of conventional reinforced concrete (RC) structures due to rocking‐induced higher‐mode amplification and nonlinear uplift–recontact behavior. This study investigates the floor response spectra (FRS) characteristics of SCW structures through combined experimental and numerical analyses and proposes a simplified generalized framework for engineering‐oriented FRS representation. Full‐scale shaking‐table test results demonstrated that resilient SCW systems develop more pronounced higher‐mode amplification and broader long‐period spectral plateaus than conventional RC structures under increasing seismic intensity while maintaining limited structural damage and stable self‐centering capability. The FRS of SCW structures exhibit characteristic bimodal spectral morphology consisting of a short‐period amplification region associated with higher‐order modal response and a long‐period plateau governed by the fundamental rocking mode. A validated nonlinear OpenSees model was subsequently used to investigate the influence of structural period, nonlinear rocking response, equivalent damping ratio, and gravity‐load distribution on FRS characteristics. Results indicate that modal properties and nonlinear rocking behavior dominate the spectral characteristics of SCW systems. Increasing seismic intensity progressively broadens the dominant spectral plateau and enhances short‐period amplification. Based on the generalized spectral characteristics identified from the numerical database, a simplified piecewise FRS representation framework was established using characteristic spectral breakpoints and representative spectral amplitudes. The proposed framework reasonably reproduces the dominant spectral morphology and spectral broadening trends observed in resilient SCW systems while substantially reducing the complexity of the original spectra.