应用屏障进行被动隔振的研究综述

Review on Passive Vibration Isolation Using Barriers

人工振动作为一种新形式的环境污染,被列为世界七大环境公害之一。各种形式的人工振动都涉及弹性波的产生和传播,在既有振源与保护区之间设立屏障来切断弹性波的传播路径,衰减振动能量,降低振动幅度,是目前国际上普通采用的隔振措施。屏障按几何构造可分为两类:连续屏障和非连续屏障。对国内外两类屏障的隔振理论和试验研究进行简述,得出的结论为:(1)连续屏障隔振效果好,但对于低频振源,屏障的深度需达到十几米以上(近似于R波的半波长),在软土和高地下水位地区的工程造价非常高,施工难度也非常大;(2)非连续屏障施工方便,不受深度和场地的限制,不需要进行额外的支护和维护,多排非连续屏障具有更广泛的应用前景。今后应注重和加强多排非连续屏障隔振的三维理论分析和吸振新材料的试验研究。

A large number of buildings and transportation facilities have been constructed in recent years.Residential areas,commercial centers,industrial areas,and highways have formed a threedimensional transportation network,and artificial vibrations are generated with high frequency and large cycle numbers.Artificial vibration has become a new type of environmental pollution,and is listed as one of the world＇s seven major environmental hazards.All the various types of artificial vibrations involve the generation and dissemination of elastic waves.Setting up of barriers between vibration sources and protection zones can block the elastic wave propagation path,attenuate the vibration energy,and reduce the vibration amplitude;this has become one of the most effective vibration isolation measures.Based on the geometric structures,normally-used barriers can be divided into two types：（1）continuous barriers,which are integrated structures,such as open trench,concrete walls,and trenches filled with mud,sawdust,or foam;and（2）discontinuous barriers,which are composed of individual elements,such as one row of cylindrical cavities,solid piles,or hollow pipe piles.In this study,theoretical and experimental studies of these twotypes of isolation barriers are reviewed and some important conclusions are drawn;（1）the effectiveness of continuous isolation barriers is better,but the depth of the barriers is usually required to be more than ten meters for vibration sources with low frequencies,which approaches half the wavelength of a Rayleigh wave,and so high construction costs and large construction difficulties are caused when constructing in soft soils or regions with high groundwater levels;（2）discontinuous barriers can be easily constructed,are not limited to depth and space,do not need additional support and maintenance,and so several rows of discontinuous barriers have more application prospects.In the future,isolation studies should focus on three-dimensional theoretical analysis and experiments on new absorbing materials with several rows of discontinuous barriers.