冻结降温对地铁盾构隧道接缝影响的数值研究

发布时间：2018-01-12 11:28

本文关键词：冻结降温对地铁盾构隧道接缝影响的数值研究　出处：《华南理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着地铁沿线周边物业高强度、高密度的开发,在地铁隧道正上方进行的基坑工程日益增多。在隔水地层条件下,地铁隧道正上方基坑工程已成功的案例较多,但针对强透水地层条件下,由于受下方隧道埋深及基坑止水帷幕无法超越隧道等条件的限制,基坑工程往往难以按常规的止水方法形成封闭的隔水体系,将可能影响甚至危及基坑工程的自身安全以及下方地铁隧道的结构安全和地铁的运营安全。对基坑两端围护结构和止水帷幕无法插入隔水地层的部位,采用冻结法实施冻结降温以形成封闭的隔水体系,可有效解决此类特殊基坑工程的止水问题,并对下方地铁隧道结构安全进行保护。受局部冻结降温的影响,下方地铁盾构隧道的力学行为将发生改变,如盾构隧道接缝张开量增大,进而可能诱发隧道渗漏水。然而,目前针对此类基坑工程冻结降温对地铁盾构隧道接缝影响所开展的相关研究甚少。本文以某冻结法止水基坑工程下方运营地铁盾构隧道为研究对象,采用Midas FEA有限元软件,建立了地铁盾构隧道的三维精细数值模型,研究了冻结降温作用对盾构隧道环缝、纵缝张开量及管片受力、变形等的影响,并初步分析了依托工程隧道渗漏水的原因。本文的主要工作和研究成果如下:(1)结合盾构隧道管片通过环向螺栓和纵向螺栓连接这一结构特点,建立了横向单环和纵向三环盾构隧道的三维精细数值模型,考虑了管片接缝、连接螺栓、手孔、橡胶密封垫等细部构造。(2)研究了四种不同冻结范围情况下,单环管片的温度场分布、纵缝张开量及单环管片的受力和变形受冻结降温影响的变化规律。对比分析了在温度工况、荷载-温度工况下,纵缝张开量以及单环管片的受力和变形受对流系数、最低冻结温度两种因素影响的变化规律。(3)研究了不同冻结范围情况下,环缝张开量及纵向三环管片的受力和变形受冻结降温影响的变化规律。分析了在温度工况下,环缝张开量以及纵向三环管片的受力和变形受对流系数、最低冻结温度两种因素影响的变化规律。(4)结合依托工程盾构隧道渗漏水案例,通过对比分析冻结降温作用下隧道的环缝、纵缝张开量,初步分析了隧道发生渗漏水的原因。
[Abstract]:Along with the MTR surrounding property of high strength, high density development, foundation pit engineering is above the subway tunnel is increasing. In the water formation condition, more cases are above the subway tunnel excavation project has been successful, but the strong permeable stratum conditions, due to tunnel buried depth and foundation pit waterproof curtain beyond tunnel conditions, excavation engineering is often difficult to stop according to conventional methods to form a closed water system, the structural safety and possible effects of iron and even endanger the safety and excavation of subway tunnel under the operation safety of foundation pit retaining structure. Both ends and waterproof curtain cannot be inserted into the water formation sites by freezing the implementation of the law of freezing temperature to form a closed water system, can effectively solve the water problem of this kind of special foundation pit, and the bottom of the subway tunnel construction safety. For protection. By partial freezing cooling effect, the mechanical behavior under the subway shield tunnel will be changed, such as the joint open shield tunnel increases, which may induce tunnel Water Leakage. However, at present this kind of foundation pit engineering research related to the freezing temperature for the metro shield tunnel joint influence carried out by little. Based on a freezing method water pit below the metro shield tunnel as the research object, using Midas finite element software FEA, 3D numerical model was established for the subway shield tunnel, the effect of freezing cooling effect of shield tunnel joints, longitudinal seam open and segment stress, deformation and so on, and analyzed the cause of tunnel project Water Leakage. The main work and research results are as follows: (1) combined with the shield tunnel segment by bolt and bolt connecting the vertical structure characteristics, establish the horizontal 3D numerical model of the single ring and vertical ring of shield tunnel, the segment joint, bolts, hand hole, rubber gaskets and other details. (2) studied four different freezing range, the temperature field distribution of single segment, longitudinal crack of single loop and the force effect of cooling and deformation by freezing. The variation regularity of comparative analysis on temperature, load and temperature conditions, and the opening of the longitudinal joints of single segment stress and deformation by the convection coefficient, variation of the minimum effect of freezing temperature two factors. (3) studied the different freezing range under the condition of ring seam open and longitudinal ring segment stress and deformation by the freezing effect of cooling were studied. Analysis of the temperature conditions, circular seam stretching and longitudinal ring segment stress and deformation by the convection coefficient, minimum freezing temperature two because of changes in the factors. (4) combined with the case of water leakage in the engineering shield tunnel, by comparing and analyzing the circumferential seam and longitudinal opening quantity of the tunnel under freezing and lowering temperature, the cause of water leakage in the tunnel is preliminarily analyzed.

【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.43;U231.3

【引证文献】