Fragility Assessment of Adjacent Buildings Coupled with Metallic Shear Dampers under Seismic Pounding Effects

Seismic pounding between adjacent buildings often exacerbates structural damage during earthquakes. This study evaluates the efficacy of metallic shear dampers in mitigating pounding effects and improving the seismic fragility of adjacent structures. A nonlinear finite element model of two adjacent mid-rise steel buildings (5- and 8-story) coupled with metallic shear dampers is developed in Abaqus. The dampers, modeled with a bilinear hysteresis law, are subjected to 20 scaled from the FEMA P-695 far-field suite. Fragility curves are derived for four damage states (slight: 0.5% drift; moderate: 1.0%; extensive: 2.0%; complete: 4.0%) and compared to uncoupled (bare) buildings. Results demonstrate that the dampers reduce peak pounding forces by 38–47% and limit maximum inter-story drifts by 25–32% across all seismic intensities. Furthermore, the coupled system reduces the probability of exceeding moderate damage by 46% and lowers collapse vulnerability by 55%. These findings highlight the coupling system’s robustness in minimizing seismic fragility and pounding risks, providing actionable insights for retrofitting adjacent buildings in earthquake-prone regions.