Low-frequency environmental vibration control for a long span suspension bridge based on phononic crystal theory

The vibrations generated by vehicles passing through cross-river bridges can be transmitted to underwater foundations, which in turn generates underwater environmental vibrations, and these long-lasting underwater environmental vibrations can be harmful to aquatic organisms. Therefore, effective vibration control measures must be applied to reduce the effects of underwater environmental vibrations. As such, the bandgap properties of phononic crystals are exploited in the present study for this vibration control. Specifically, scaled models of bridge tower and periodic piles are designed and constructed according to the design plan of a suspension bridge. Then, a reasonable phononic crystal structure is selected, and the bandgap properties are investigated by using the finite element method. Finally, the vibration attenuation test of the scale model is carried out to study the attenuation effects of the phononic crystal structure. The research shows that the optimized vibration attenuation effect of the bridge tower and the periodic piles reaches more than 80% in the theoretical band gap range of the phononic crystal. Meanwhile, the frequency range of the actual vibration attenuation is consistent with the results of the finite element calculations, which validates the reliability of the simulation and also proves the feasibility of the phononic crystal structure in the underwater low-frequency environmental vibration control of the suspension bridge.