Multihazard Dynamic Response Control of Long-Span Cable-Stayed Bridges Using Spatially Distributed Tuned Mass Dampers

Long-span cable-stayed bridges present significant engineering challenges due to their susceptibility to dynamic excitations across multiple frequency ranges. This study develops an innovative vibration control system that simultaneously addresses three distinct loading scenarios: seismic vibrations, wind-induced oscillations, and high-speed rail excitations. The proposed solution integrates tridirectional tuned mass dampers (TMDs) with refined spatial distribution to create a comprehensive protection system. Essentially, the research presents a novel multiple tuned mass damper configuration featuring three key innovations: tridirectional control capability for simultaneous management of vertical, lateral, and torsional vibrations; energy tunneling concept that strategically redirects vibrational energy to more easily damped higher frequencies; and iteratively refined spatial distribution based on detailed modal analysis of critical structural zones. The effectiveness of the system is evaluated through comprehensive performance metrics, including structural response parameters, force distributions, and energy dissipation characteristics. Through comparative analysis, the study demonstrates that the enhanced configuration provides superior performance when compared to conventional TMD-based vibration control strategies. The system achieves consistent response reduction across all excitation frequencies while avoiding the detrimental detuning effects commonly observed in simpler systems. The solution maintains superior performance under various loading combinations, offering reliable protection against multihazard scenarios. The integrated design methodology developed in this research provides engineers with a practical framework for creating resilient cable-stayed bridges that can withstand diverse, dynamic challenges while meeting stringent safety and serviceability requirements.