隧道施工对交叉隧洞稳定性影响分析

发布时间：2018-08-08 20:10

【摘要】：本文针对工程中常遇到的空间交叉隧道施工稳定性问题,研究和总结近接隧道施工基本应力场理论、围岩破坏机理及分类标准、影响程度判断准则及分区标准等基本理论。运用ABAQUS有限元软件,模拟分析从化至东莞高速公路左右双线隧道开挖施工对下方已有的空间交叉东深供水隧洞产生的稳定性影响。具体包括以下几个方面研究内容:(1)通过对工程所处区域地质概况的调研以及隧洞交叉段的工程地质条件总结,进行围岩稳定性评价,对围岩进行分类,确定了隧洞及围岩的物理力学参数建议值。(2)针对工程实际情况,建立ABAQUS三维有限元模型,运用对公路隧道不同类别的围岩参数分别进行隧道开挖模拟,得出不同参数对围岩及交叉段供水隧洞衬砌的应力计算结果的影响规律。(3)分别模拟右线和左线公路隧道开挖过程,得出开挖引起的围岩变形和应力值大小,得出了交叉段供水隧洞衬砌因开挖产生的附加拉应力及附加压应力的分布规律,确定了最大附加拉、压应力值及作用位置。(4)计算得出了开挖结束后,交叉段供水隧洞围岩及衬砌最终的变形大小,以及最大拉应力和最大压应力的大小及作用位置,并将最大拉、压应力结果与供水隧洞衬砌的抗拉、抗压强度对比,判断其稳定性为安全。(5)考虑分步开挖,将隧道按开挖一段、立即衬砌一段的实际开挖过程进行了有限元模拟,得出分步开挖后围岩及交叉段供水隧洞变形及应力结果,选取供水隧洞典型断面及主要特征点,得出了各点应力和变形随开挖步骤的变化曲线,总结出了各点的应力及变形变化规律。(6)根据有限元数值分析和公式计算结果,对输水隧洞得出结构分析结论和安全评价,并给出具体建议。
[Abstract]:In this paper, the basic stress field theory, failure mechanism and classification standard of surrounding rock, criterion of influence degree and zoning standard are studied and summarized in view of the stability of space crossing tunnel construction which is often encountered in engineering. By using ABAQUS finite element software, this paper simulates and analyzes the influence of the excavation of the left and right double-line tunnel of Conghua to Dongguan expressway on the stability of the existing space crossing Dongshen water supply tunnel. The specific research contents include the following aspects: (1) through the investigation of the regional geological situation of the project and the summary of the engineering geological conditions of the tunnel crossing section, the stability of surrounding rock is evaluated and the surrounding rock is classified. The suggested values of the physical and mechanical parameters of the tunnel and surrounding rock are determined. (2) according to the actual situation of the project, the three-dimensional finite element model of ABAQUS is established, and the tunnel excavation simulation is carried out by using different kinds of surrounding rock parameters of the highway tunnel. The influence of different parameters on the stress calculation results of surrounding rock and cross section water supply tunnel lining is obtained. (3) the excavation process of right and left highway tunnel is simulated, and the deformation and stress value of surrounding rock caused by excavation are obtained. The distribution law of additional tensile stress and additional compressive stress caused by excavation for the lining of cross section water supply tunnel is obtained, and the maximum additional tensile stress and compressive stress value and action position are determined. (4) after the excavation is finished, the distribution of additional tensile stress and additional compressive stress is obtained. The final deformation of the surrounding rock and lining of the cross section water supply tunnel, and the magnitude and position of the maximum tensile stress and the maximum compressive stress are compared with the tensile and compressive strength of the lining of the water supply tunnel. The stability of the tunnel is judged to be safe. (5) considering the step excavation, the actual excavation process of the tunnel is simulated by finite element method, and the deformation and stress results of the surrounding rock and the water supply tunnel in the cross section after the step excavation are obtained. By selecting typical section and main characteristic points of water supply tunnel, the variation curves of stress and deformation of each point with excavation steps are obtained, and the variation law of stress and deformation at each point is summarized. (6) according to the results of finite element numerical analysis and formula calculation, The conclusion of structure analysis and safety evaluation of water conveyance tunnel are obtained, and some concrete suggestions are given.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455

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