Numerical modelling of ground borne vibrations from high speed rail lines on embankments
Numerical modelling of ground borne vibrations from high speed rail lines on embankments
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DOI：
10.1016/j.soildyn.2012.12.003
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发表时间：
2013-03-01
影响因子：
4
通讯作者：
Forde, M. C.
中科院分区：
文献类型：
--
作者：
Connolly, D.;Giannopoulos, A.;Forde, M. C.
本文提出了一个能模拟高速铁路附近地面振动传播和传递的三维数值模型。该模型是一个时域显式动力有限元模型，能够模拟非线性激励机制，用于研究路堤组成材料对离轨道不同距离处的地基振动水平的影响。整个模型，包括车轮/轨道接口是完全耦合的。考虑到土壤结构的无界性，在截断界面处设置了吸收边界条件（无限元）。为了提高边界吸收性能，土壤结构采用细长球形几何体建模。与轨道部件相关的复杂几何体详细建模，从而允许高度逼真地模拟车辆到路堤的力传递。最后，采用非线性赫兹接触理论建立了与轨道完全耦合的多体模型，对车辆机车的准静态和动态激振机理进行了描述，并利用现场试验采集的高速列车地面振动数据对模型进行了验证。然后，它被用来调查的作用，在振动的传输。结果发现，软阻尼器表现出大的偏转和铁路振动被困在结构内的波导。这导致路堤内部和周围土壤的振动水平增加。相比之下，发现由较硬的材料形成的增强体减少了近场和远场中的振动。(C)2012爱思唯尔有限公司保留所有权利。
A three dimensional numerical model is presented capable of modelling the propagation and transmission of ground vibration in the vicinity of high speed railways. It is used to investigate the effect of embankment constituent material on ground borne vibration levels at various distances from the track.The model is a time domain explicit, dynamic finite element model capable of simulating non-linear excitation mechanisms. The entire model, including the wheel/rail interface is fully coupled. To account for the unbounded nature of the soil structure an absorbing boundary condition (infinite element) is placed at the truncated interfaces. To increase boundary absorption performance, the soil structure is modelled using an elongated spherical geometry.The complex geometries associated with the track components are modelled in detail thus allowing a highly realistic simulation of force transmission from vehicle to embankment. Lastly, quasi-static and dynamic excitation mechanisms of the vehicle locomotives are described using a multi-body approach which is fully coupled to the track using non-linear Hertzian contact theory.The resulting model is verified using experimental ground borne vibration data from high speed trains, gathered through field trials. It is then used to investigate the role of embankments in the transmission of vibration. It is found that soft embankments exhibit large deflections and act as a waveguide for railway vibrations which are trapped within the structure. This results in increased vibration levels both inside the embankment and in the surrounding soil. In contrast it is found that embankments formed from stiffer material reduce vibrations in the near and far fields. (C) 2012 Elsevier Ltd. All rights reserved.