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

摘要： 由于城市轨道交通运行引起的环境振动和噪声日益突出，减振降噪问题近年来成为人们关注的焦点。周期性排桩是在传播路径上对振动波进行阻隔的一种减隔振措施，但实际工程应用时周期性排桩在低频范围内的减隔振效果并不佳。因此，本文提出了一种能够用于20Hz以下低频减隔振的环保型四组元周期性排桩，并应用自适应遗传算法对其低频减振性能进行了深度优化。首先基于复频曲线确定了四组元周期性排桩各部分采用环保材料时的最优材料匹配；然后运用自适应遗传算法对四组元周期性排桩各组成部分的尺寸参数进行优化，使其能够在低频范围内打开较宽的带隙，并进一步给出了减振频带范围分别在9.5Hz-15.5Hz、11.9Hz-20Hz、14.3Hz-24.2Hz、16.3Hz-27.5Hz时的排桩设计参数；最后针对优化出的带隙范围，以9.5Hz-15.5Hz的低频减振频带为例分别在时域内和频域内对周期性排桩的减隔振性能进行了深入分析，研究结果表明本文所提出的四组元周期性排桩在低频范围内具有优良的减隔振性能，具有较好的工程应用价值。

关键词: 周期性排桩, 低频减隔振, 复频曲线, 自适应遗传算法