多排桩屏障远场被动隔振分析

视桩为弹性半空间中的异质体，以瑞利波散射的积分方程为基础，首次对多排桩屏障的远场被动隔振效果进行了三维分析。详细讨论了影响隔振效果的几个主要参数，指出非连续排桩屏障隔振起到的是整体屏蔽作用。研究表明，影响多排桩屏障体系隔振效果的厚度主要取决于桩的排数，与桩的截面尺寸关系不大；密布小截面多排桩隔振效果与空沟和填充沟相当；桩的排距对隔振效果影响小；每一排桩的桩间净距是影响隔振效果的重要参量，为了获得满意的隔振效果，应控制相邻桩的桩间距足够小。最后，通过工程实例验证了多排桩的隔振效果。

ANALYSIS OF MULTI-ROW OF PILES AS BARRIERS FOR ISOLATING VIBRATION IN FAR FIELD

Based on the integral equation of Rayleigh wave scattering, piles are treated as irregular obstacles in elastic half-space. This paper presents three-dimensional multi-row piles as ground barriers for passive isolating vibration in far field for the first time. Effects of relevant parameters on the effectiveness of vibration isolation are analyzed and presented. The theoretical results demonstrate that the rows of piles as discontinuous barriers can be functioned as an integrated system to isolate ground vibration. The number of row mainly determines the thickness of barrier system, which affects screening effectiveness. The cross-section size of each pile may have less effect on the vibration isolation. The screening effectiveness by rows of small cross-section piles densely arranged can be as good as that of the open trench and in-filled trenches. The space between the pile rows may have less effect on the vibration reduction. The net spacing between piles along each row can be an important factor for the vibration isolation; it can be determined by the practical engineering. In order to obtain satisfied effectiveness of isolating vibration of the rows of piles as discontinuous barriers; the distance between piles in a row should be controlled close enough. At last, a case history proves the good isolation effect by rows of piles. The method and findings presented are useful in the design of ground barrier and can be used to predict the functions of rows of piles as barrier system for ground vibration.