Configuration tuning of rocking structural systems through an integrated stiffness–damping redistribution strategy

This study proposes a novel Demountable Rocking Segmental (DRS) system to effectively tune the configuration and seismic response of mid- to high-rise buildings through an integrated redistribution of stiffness and damping. Unlike conventional base-rocking wall systems, which are often constrained by concentrated energy dissipation at the base and pronounced higher-mode effects, the proposed system combines wall segmentation with strategically distributed floor-level dampers to simultaneously control inter-story drift and floor acceleration while enabling structural demountability. Wall segmentation is employed to reduce and redistribute lateral stiffness, thereby mitigating floor accelerations and inertial forces. In parallel, floor-level dampers are introduced to distribute energy dissipation along the building height, effectively suppressing excessive lateral drifts. A simplified analytical framework is first developed to describe the force–displacement behavior of the system and support preliminary design. Subsequently, nonlinear numerical models are established and validated against experimental results. A comprehensive parametric study is conducted to investigate the influence of key design variables, including the number of segments, stiffness ratio, and damper location. The results indicate that configurations with four to five segments, a stiffness ratio between 0.2 and 1, and dampers placed in the upper 25% of the building height provide an effective balance between drift and acceleration reduction. To further tune the system configuration, a multi-objective optimization framework based on the NSGA-II algorithm is employed, considering drift, acceleration, and damping demand simultaneously. Pareto-optimal configurations are identified, and both optimal and economic design points are determined. Nonlinear time-history analyses demonstrate that the configuration-tuned DRS system significantly reduces the mean peak seismic demands across the ensemble of ground motions compared to conventional base-rocking wall systems, achieving mean reductions of up to 16% in inter-story drift, 29% in floor acceleration, and 33% in story shear. These results confirm that the proposed system offers a balanced and efficient solution for mitigating critical seismic demands in tall buildings.