Effects of above-crossing tunnelling on the existing shield tunnels
Effects of above-crossing tunnelling on the existing shield tunnels
复制标题
上穿隧道对既有盾构隧道的影响
DOI：
10.1016/j.tust.2016.05.002
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发表时间：
2016-09-01
影响因子：
6.9
通讯作者：
Yu, Feng
中科院分区：
文献类型：
--
作者：
Liang, Rongzhu;Xia, Tangdai;Yu, Feng
在人口稠密的市区进行隧道挖掘工程，往往会导致跨越或绕过现有隧道。显然，当跨线隧道施工引起的变形超过隧道结构的承载能力时，将对既有隧道产生不利影响，甚至造成破坏。越来越多的人开始关注跨线隧道和下伏隧道之间的相互作用。为了更好地了解上跨隧道施工对既有隧道的影响，并提供一种快速而低成本的评估方法，以评估施工前的下卧隧道的行为，简化的分析方法，提出了这项研究。在这种简化方法中，隧道被简单地认为是一个连续的Euler-Bernoulli梁具有一定的等效弯曲刚度。在不考虑既有隧道的情况下，通过Mindlin解计算了跨线隧道施工引起的隧道位置卸荷应力。然后，基于公认的Winkler地基模型，分析了卸荷应力引起的隧道-土相互作用。三个有据可查的案例验证了所提出的方法的适用性。这些案例研究的结果表明，合理的预测和观察之间的协议。最后，通过参数分析，研究了不同因素对既有隧道施工性状的影响，包括净距、推进距离和多隧道施工。(C)2016爱思唯尔有限公司版权所有
Tunnelling in the dense urban areas frequently results in over-crossing or bypassing the existing tunnels. It is obvious that the over-crossing tunnelling will adversely affect and even damage the existing tunnels if the induced deformation exceeds the capacity of tunnel structures. Increasing concerns have been raised about the interactions between the over-crossing tunnelling and underlying tunnels. In order to obtain a better mechanical understanding of the effects of the over-crossing tunnelling on the existing tunnels and provide a quick but low cost assessment alternative method for evaluating the behavior of underlying tunnels prior to construction, a simplified analytical method is proposed in this study. In this simplified method, the tunnel is simply considered as a continuous Euler-Bernoulli beam with a certain equivalent bending stiffness. The unloading stress at the tunnel location caused by the over-crossing tunnelling is computed through Mindlin's solution, ignoring the presence of the existing tunnel. Then, the tunnel-soil interaction due to the relief stress is analyzed based on the commonly-accepted Winkler foundation model. The applicability of the presented method is validated by three well-documented case histories. Results of these case studies show a reasonable agreement between the predictions and observations. Finally, a parametric analysis is also preformed to investigate the influences of the different factors on the behavior of the existing tunnels, including clearance distance, advancing distance and multiple tunnels construction. (C) 2016 Elsevier Ltd. All rights reserved.