Optimising low acoustic impedance back-fill material wave barrier dimensions to shield structures from ground borne high speed rail vibrations
Optimising low acoustic impedance back-fill material wave barrier dimensions to shield structures from ground borne high speed rail vibrations
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DOI：
10.1016/j.conbuildmat.2013.03.034
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发表时间：
2013-07
影响因子：
7.4
通讯作者：
D. Connolly;A. Giannopoulos;Weizhi Fan;P. Woodward;M. Forde
中科院分区：
文献类型：
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作者：
D. Connolly;A. Giannopoulos;Weizhi Fan;P. Woodward;M. Forde
由于高速列车通过而产生的地面振动会对附近环境造成不良影响。减轻振动水平的一种方法是使用“波屏障”，然而它们的安装成本可能非常高。为了尽量减少施工成本，进行了数值模拟和物理实验，以确定优化沟槽尺寸的指导方针。大量的节省被认为是可以实现的，通过仔细选择的屏障尺寸。首先，为了测试的数值模型，可用于铁路波屏障设计师的目的，地球物理调查是在苏格兰爱丁堡以外的高速铁路线进行。测试计划包括邻近线路的振动测量和表面波技术的多通道分析，以确定底层土壤特性。然后提出了一个大纲，描述了一个新开发的三维有限元铁路模型，使用商业可用的软件。由此产生的模型进行修改，以复制的轨道和土壤性质在测试现场，然后它表明，该模型的结果表现出较强的相关性相比，在实验阶段收集的。数值模型，然后使用一系列的波屏障配置，以保护附近的网站从铁路振动的能力进行评估。结果发现，深度和长度有很大的影响，但沟槽宽度的影响是可以忽略不计的振动水平的缓解。最后，对于一个具体的例子，它表明，95%的成本节约是可以实现的，如果沟槽尺寸仔细规划。所有的分析都要求土壤与波障回填材料的声阻抗之比必须大于8。
Ground borne vibrations generated due to high speed train passage can cause undesirable effects on the nearby environment. One approach to mitigate vibration levels is to use “wave barriers”, however their installation cost may be very high. In an attempt to minimize construction costs, numerical modelling and physical experiments are performed to determine guidelines for the optimisation of trench dimensions. Substantial savings are found to be achievable through carefully chosen barrier dimensions. Firstly, for the purposes of testing a numerical model that can be used by railway wave barrier designers, a geophysical investigation is undertaken on a high speed railway line outside Edinburgh, Scotland. The testing schedule consists of vibration measurements adjacent to the line and a multi-channel analysis of surface waves technique to determine the underlying soil properties. An outline is then presented describing a newly developed three dimensional finite element railway model using commercially available software. The resulting model is modified to replicate the track and soil properties at the test site and then it is shown that the model results exhibit a strong correlation in comparison to those collected during the experimental stage. The numerical model is then used to assess the ability of a range of wave barrier configurations to protect nearby sites from railway vibration. It is found that depth and length have a strong influence on the mitigation of vibration levels but the effect of trench width is negligible. Lastly, for a specific example it is shown that cost savings of 95% are achievable if trench dimensions are carefully planned. All of the analyses require that the ratio of the acoustic impedance of soil compared to wave barrier backfill material must be greater than eight.