均质地基中空沟对交通荷载的隔振分析

Analysis of isolating vibration from traffic by open trench in homogenous ground

为了研究二维均质地基中空沟对作用于路基顶部交通荷载的隔振效果,基于格子法理论,提出使用二维格子法分析空沟隔振的方法,并给出一种实用的人工边界条件。采用最大位移幅值系数作为隔振效果评价标准,利用上述方法分析空沟宽度、深度、位置和路堤高度及泊松比对隔振效果的影响。提出影响因子的概念,建立空沟隔振效果的简化计算模型。在该模型中,上述几个因素对空沟隔振效果的影响分别定量地表示为影响因子,其乘积可综合反映空沟隔振效果。根据格子法的计算结果,给出影响因子的计算公式,并进行算例验证。研究结果表明:空沟的深度和位置是影响空沟隔振效果的关键因素,两者的取值应同时考虑;泊松比越大,越不利于空沟隔振。

Based on the grid method theory,the screening effectiveness was studied by open trench.A practical artificial boundary condition was presented for analyzing the isolation vibration by open trench from traffic loads acting on the top of an embankment in 2-D homogenous ground.The amplitude ratio of maximum displacement was utilized for evaluating the isolation efficiency.Using the grid method,the main influence factors on the isolation efficiency,including the width,depth,location of open trench,the height of embankment and Poisson＇s ratio,were analyzed respectively.A new simplified calculation model was proposed for evaluating the isolation efficiency of the open trenches together with introducing influence factors.In the model,the influences of the factors mentioned above were respectively denoted as some influence factors.The product of these influence factors represents the isolation efficiency.The computing equations were presented for the influence factors on the basis of the results from the grid method.The equations were verified by the examples.The results show that the depth and location of open trench are key influence factors on the isolation efficiency.So the both factors should be considered simultaneously.A great Poisson＇s ratio of the ground soil is harmful to the isolation efficiency.