Innovative shear link coupling system for vibration synchronization and seismic pounding mitigation in reinforced concrete buildings

Seismic pounding and out-of-phase vibrations are critical issues for adjacent reinforced concrete structures. This research introduces an innovative shear link coupling system to synchronize inter-structural vibrations and mitigate pounding. The shear link coupling system connects adjacent buildings through replaceable, energy-dissipative shear links with tailored stiffness and ductility, allowing controlled deformation and energy absorption. The efficacy of this Novel Coupling System (NCS) is compared against a conventional Individual Building Retrofit (IBR) for two adjacent four-story reinforced concrete buildings with a 2.5 cm gap. The IBR uses steel chevron braces with aluminum links, while the NCS connects the buildings with steel rigid beams and aluminum links to enforce response synchronization. Advanced finite element modeling and nonlinear time-history analysis are used to evaluate interstory drift ratio, acceleration, and pounding potential. The analysis reveals that while the IBR reduces impacts, it cannot prevent hazardous collisions. In contrast, the NCS completely eliminates pounding by enforcing synchronization. The NCS dissipates nearly 65% of input energy through its links, compared to 45% for the IBR. Fragility analysis demonstrates that the NCS increases the median collapse capacity of the structures by over 300% relative to their as-is condition. The results show a significant reduction in seismic demand and pounding forces. The shear link coupling system’s enhanced resilience and reparability make it a viable solution for dense urban areas. This confirms that a design philosophy based on enforced synchronization is fundamentally more effective for mitigating seismic pounding than conventional independent-building strengthening.