Centrifuge and numerical modelling of ground-borne vibration from an underground tunnel
Centrifuge and numerical modelling of ground-borne vibration from an underground tunnel
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DOI：
10.1016/j.soildyn.2013.04.004
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发表时间：
2013-08
影响因子：
4
通讯作者：
Wen-bo Yang;M. Hussein;A. Marshall
中科院分区：
文献类型：
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作者：
Wen-bo Yang;M. Hussein;A. Marshall
地下隧道引起的地面振动是城市地区的一个主要环境问题。各种研究，主要是基于数值方法，已经进行了调查这个问题。在数值模型中，为了简化问题，通常假定土壤刚度和阻尼随深度保持不变（均质假设）。然而，岩土工程领域的各种研究表明，由于围压增加的影响，土壤性质随深度而变化。本文研究了土层性质随深度的变化（土层的非均匀性）对地下隧道地表振动的影响。离心机和数值模拟都用于进行研究。在离心模型中，一个塑料管埋在沙子里模拟地下隧道。采用小型振动台对模型隧道仰拱进行振动激振。隧道和土壤的反应是在测试过程中使用加速度计测量。基于FLAC 3D软件建立了相应的数值模型，对离心试验进行了模拟。通过数值模型对离心试验的潜在边界效应进行了研究。均质和非均质情况下的模型响应也通过数值模型计算。实验和数值计算结果的比较表明，一个均匀的模型可以给出可接受的估计的隧道行为。然而，一个明显的改善土壤行为的估计时，观察到土壤性质随深度的变化被认为是在数值模型。
Ground-borne vibration from underground tunnels is a major environmental concern in urban areas. Various studies, mostly based on numerical methods, have been conducted to investigate this problem. In the numerical models, soil stiffness and damping are commonly assumed to remain constant with depth (homogeneous assumption) in order to simplify the problem. However, various studies in the field of geotechnical engineering have shown that soil properties change with depth due to the effect of increased confining stress. This paper presents a study of the effects of variation of soil properties with depth (soil non-homogeneity) on ground-borne vibration from an underground tunnel. Both centrifuge and numerical modelling were used to perform the study. In the centrifuge model, a plastic pipe was buried within sand to model the underground tunnel. Vibration excitation was applied to the model tunnel invert by a small shaker. The tunnel and soil response was measured using accelerometers during the tests. Corresponding numerical models, based on FLAC 3D, were built to simulate the centrifuge tests. The potential boundary effects of the centrifuge tests were examined by the numerical models. The model responses for both homogenous and non-homogenous cases were also calculated by the numerical models. Comparison of the experimental and numerical results shows that a homogenous model can give acceptable estimates of the tunnel behaviour. However, a clear improvement of estimates of soil behaviour is observed when the variation of soil properties with depth is considered in the numerical model.