关键词: 周期性排桩, 低频减隔振, 复频曲线, 自适应遗传算法

Abstract: The environmental vibration and noise caused by the operation of urban rail traffic have become increasingly prominent, making the issue of vibration and noise reduction a key research focus in recent years. Periodic pile barriers serve as a mitigation measure by blocking vibration waves along the propagation path. However, in practical engineering applications, the conventional periodic piles exhibit poor vibration isolation performance in the low-frequency range. To address this issue, an eco-friendly four-component periodic pile barrier has been proposed, which is capable of effective vibration isolation below 20 Hz, and its low-frequency performance was optimized by using an adaptive genetic algorithm. Firstly, based on the complex dispersion curves, the optimal material composition for each component of the four-element periodic pile barrier was determined, ensuring the use of environmentally friendly materials. Then, the adaptive genetic algorithm was employed to optimize the dimensional parameters of each component, enabling the generation of wide bandgaps in the low-frequency range. The optimized design parameters achieved vibration isolation bands in the ranges of 9.5 Hz-15.5 Hz, 11.9 Hz-20 Hz, 14.3 Hz-24.2 Hz, and 16.3 Hz-27.5 Hz. Finally, taking the 9.5-15.5 Hz low-frequency isolation band as an example, the vibration isolation performance of the periodic pile barrier was thoroughly analyzed in both the time and frequency domains. The results demonstrate that the proposed four-component periodic pile barrier exhibits excellent low-frequency vibration isolation performance, indicating significant potential for engineering applications.

Key words: Periodic pile barrier, low-frequency vibration isolation, complex dispersion curve, adaptive genetic algorithm