耦合渗流场的TBM输水隧洞三维有限元分析

发布时间：2018-04-10 05:05

本文选题：TBM输水隧洞　切入点：衬砌管片　出处：《天津大学》2014年硕士论文

【摘要】：TBM掘进技术凭借其机械化程度高、施工速度快、对外界干扰性小、掘进作业安全等优点成为长距离深埋输水隧洞开挖施工的首要选择。目前TBM隧洞稳定性分析中大多或是不予考虑外水压力,或是采用“水-岩分算”的方法将外水压力简化为面力施加于衬砌结构的边界,并且TBM隧洞工程的分析中多将衬砌简化为均质渗透体,未能考虑到TBM隧洞工程中渗水主要发生在管片接缝等局部区域。此外,大多隧洞工程研究中采用的地质模型都进行了不同程度的简化,多将地质体简化均质体。针对目前研究中的一些不足之处,结合某TBM输水隧洞工程实例,开展了耦合渗流场的TBM输水隧洞三维有限元分析,在总结现有研究成果的基础上,取得了如下研究成果:(1)针对目前大多关于隧洞工程的研究中将隧洞围岩简化成均质体的不足,构建隧洞围岩三维地质模型。从工程地质建模数据结构、地质体建模技术等方面进行地质建模理论的介绍,并在该理论的基础上采用Visual Geo系统,结合工程实例,构建TBM输水隧洞围岩三维地质模型,为TBM输水隧洞围岩渗流场数值模拟和隧洞稳定性分析提供更加符合工程实际的地质模型。(2)结合TBM输水隧洞的工程特点,实现隧洞管片接缝渗水的渗流场的模拟,并将水荷载以体积力的形式作用在结构分析中。基于隧洞围岩三维地质模型,针对深埋TBM输水隧洞在较大外水压力下容易在衬砌管片接缝处渗水的工程特点,利用自编的脚本文件解决耦合分析模型中渗流场与应力场两套非匹配网格之间的数据传递问题,将考虑渗水发生在管片接缝位置的渗流场中的地下水压力以体积力的形式耦合至TBM输水隧洞的稳定性分析模型中。在三维结构计算结果中,利用应力路径积分方法得到管片衬砌的轴力、弯矩的分布情况。(3)引进基于正交试验设计的敏感性分析方法,分析隧洞围岩参数对于隧洞稳定性评价指标的敏感性大小。将基于正交试验设计的敏感性分析方法引入隧洞渗流应力耦合分析模型,采用三维有限元分析方法计算各个因素不同取值时的隧洞衬砌最大主应力、最小主应力、最大径向位移三个隧洞稳定性的评价指标。利用极差分析方法分析了隧洞稳定性评价指标对6个围岩参数的敏感性,为类似工程的设计提供指导。
[Abstract]:With the advantages of high mechanization, fast construction speed, little interference to the outside world and safety of tunneling operation, TBM tunneling technology has become the first choice in the excavation of long distance and deep buried water conveyance tunnel.At present, in the stability analysis of TBM tunnel, either the external water pressure is not considered, or the external water pressure is simplified to the boundary of the lining structure by the method of "water-rock separation".In the analysis of TBM tunnel, the lining is simplified to homogeneous permeability, which fails to take into account that the seepage occurs mainly in the segment joint and other local areas in the TBM tunnel project.In addition, most of the geological models used in tunnel engineering research have been simplified to varying degrees, and the geological bodies are mostly simplified as homogeneous bodies.In view of the shortcomings of the present research, combined with an example of a TBM water conveyance tunnel, the three-dimensional finite element analysis of the coupled seepage field of the TBM water conveyance tunnel is carried out. On the basis of summing up the existing research results, the three dimensional finite element analysis of the coupled seepage field is carried out.The following research results have been obtained: (1) aiming at the deficiency of most of the current researches on tunnel engineering to simplify the surrounding rock of tunnel into homogeneous mass, a three-dimensional geological model of surrounding rock of tunnel is constructed.This paper introduces the geological modeling theory from the aspects of engineering geological modeling data structure, geological body modeling technology and so on. On the basis of this theory, a three-dimensional geological model of surrounding rock of TBM water conveyance tunnel is constructed by using Visual Geo system and engineering examples.For the numerical simulation of surrounding rock seepage field of TBM water conveyance tunnel and the analysis of tunnel stability, a more practical geological model is provided. Combining with the engineering characteristics of TBM water conveyance tunnel, the seepage field of tunnel pipe joint seepage can be simulated.And the water load acts in the form of volume force in the structure analysis.Based on the 3D geological model of tunnel surrounding rock, this paper aims at the engineering characteristics of deep buried TBM water conveyance tunnel which is easy to seep water at the joint of lining pipe under large external water pressure.The self-compiled script file is used to solve the data transfer problem between two sets of mismatched meshes in the coupled analysis model.The groundwater pressure in the seepage field where seepage occurs at the joint position of the pipe piece is coupled to the stability analysis model of the TBM water conveyance tunnel in the form of volume force.In the result of 3D structure calculation, the stress path integral method is used to obtain the axial force and the distribution of bending moment of segment lining. (3) the sensitivity analysis method based on orthogonal test design is introduced.The sensitivity of surrounding rock parameters to the evaluation index of tunnel stability is analyzed.The sensitivity analysis method based on orthogonal test design is introduced into the seepage stress coupling analysis model of tunnel, and the maximum principal stress and minimum principal stress of tunnel lining are calculated by using three-dimensional finite element analysis method with different values of each factor.Evaluation index of stability of three tunnels with maximum radial displacement.The sensitivity of tunnel stability evaluation index to six surrounding rock parameters is analyzed by means of range analysis method, which provides guidance for the design of similar projects.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV554;TV223

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