冻融作用引起上部隧道变形规律研究

发布时间：2018-11-09 09:37

【摘要】：随着城市地铁建设的迅猛发展,地下轨道交通线路越来越多。由于规划设计滞后或者周边存在既有结构体,使得立体交叉线路不得不进行穿越施工。目前,冻结法已成为暗挖隧道安全穿越施工中一种最可靠的工法。然而,冻胀融沉现象又不可避免的造成既有结构的变形甚至破坏。武汉市轨道交通机场线盘龙城站~宏图大道站区间6#联络通道下穿3#隧道冻结法施工,属于长距离联络通道近距离穿越既有隧道工程。本文通过理论模型计算、数值模拟和物理模型试验相结合的方法对该工程案例进行详细研究。首先,将经典的平面随机介质理论扩展到三维,推导出空间地层任意微单元体开挖造成上方任意位置处的各个方向位移变化计算公式。在此基础上,建立能够预测冻融作用引起上部地层任意一点位移变化的三维冻胀融沉计算模型。随后,运用建立的三维冻胀融沉计算模型对工程案例进行计算。通过计算结果的分析,得到6#长距离联络通道冻结法施工过程中,上部3#线既有隧道位置处的地层冻胀、融沉位移变化规律。其次,利用ANSYS有限元软件,对工程案例建立数值计算模型。通过对该案例进行典型参数研究,模拟6#长距离联络通道冻结法施工。分析计算结果,得到冻结施工过程中上部3#线既有隧道冻胀融沉位移变化规律。接着对3#隧道冻胀位移开展单因素影响研究。再次,基于相似理论,对工程案例进行模化设计,并在实验室实施物理模拟试验。最后,对理论解析、有限元数值计算和模型试验得出的结论相互对比验证,总结出本文研究成果,并对后续工作提出研究展望。
[Abstract]:With the rapid development of urban subway construction, there are more and more underground rail transit lines. Due to the delay of planning and design or the existence of existing structures in the periphery, the crossing line has to be constructed. At present, freezing method has become the most reliable method in tunneling safe crossing construction. However, the phenomenon of frost heaving and thawing will inevitably cause deformation and even destruction of existing structures. The freezing construction of tunnel under 6 # contact channel between Panlong City Station and Hongtu Avenue Station of Wuhan rail transit airport line belongs to the project of long distance contact channel and short distance passing through the existing tunnel. In this paper, the engineering case is studied in detail by the combination of theoretical model calculation, numerical simulation and physical model test. Firstly, the classical theory of plane random medium is extended to 3D, and the formula of displacement variation in every direction caused by the excavation of arbitrary microelement in space stratum is deduced. On this basis, a three-dimensional frost heave and thawing settlement model is established to predict the change of displacement at any point in the upper stratum caused by freeze-thaw process. Then, the three-dimensional frost heaving and thawing settlement model is used to calculate the engineering case. Through the analysis of the calculation results, the variation of frost heaving and thawing displacement of the upper section of the tunnel is obtained during the construction of the freezing method of 6 # long distance connection channel. Secondly, the numerical model of engineering cases is established by using ANSYS finite element software. By studying the typical parameters of this case, the construction of 6 # long distance contact channel freezing method is simulated. By analyzing the calculation results, the variation law of frost heave and thawing settlement displacement of the existing tunnel on the upper wall of the upper wall is obtained during the freezing construction. Then the influence of single factor on the frost heaving displacement is studied. Thirdly, based on the similarity theory, the simulation design of engineering cases is carried out, and the physical simulation test is carried out in the laboratory. Finally, the conclusions of theoretical analysis, finite element numerical calculation and model test are compared and verified, the research results of this paper are summarized, and the research prospects for the follow-up work are put forward.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U451

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