施工隧道质量安全评估及数值模拟研究

发布时间：2018-10-08 18:39

【摘要】：随着我国经济的快速发展,城市化进程也已步入高速发展阶段,城市地面交通量的快速增加,交通拥堵、路面交通供需不足现象也越发严重。如今,以隧道工程为主的地下空间的开发利用已经作为发达国家解决城市资源、人口、环境三大危机的重要途径。伴随而来的是隧道开挖后的稳定性问题,本文通过运用有限差分软件FLAC3D,分析了隧道开挖对围岩位移与应力的影响。在数值模型中,衬砌采用线弹性材料,土体采用Mohr-Coulomb弹塑性模型。首先,本文结合东至县龙头岭隧道,分别采用CRD法、台阶法、全断面法等不同开挖方法模拟分析围岩结构的稳定性,通过对比分析,可得到以下主要结论：(1)隧道开挖引起的拱顶与拱底围岩位移沉降较大,拱腰处出现应力集中现象,衬砌支护使得围岩应力得到一定的缓解；(2)CRD法开挖引起的位移沉降最小,安全性高；(3)隧道开挖引起的地表沉降槽形状呈颠倒的正态分布曲线；(4)随着土体深度的增加,土体位移沉降越来越大。其次,分析各种影响因素对围岩结构稳定性的影响以及小净距隧道开挖围岩结构稳定性的研究。最后,从多个方面阐述了隧道施工过程中的安全预防与控制措施。本文所得数值模拟结果能为实际工程提供理论指导。
[Abstract]:With the rapid development of China's economy, the urbanization process has also entered the stage of high-speed development, the rapid increase of urban ground traffic volume, traffic congestion, the shortage of road traffic supply and demand is becoming more and more serious. Nowadays, the development and utilization of underground space based on tunnel engineering has become an important way for developed countries to solve the problems of urban resources, population and environment. Along with the stability of tunnel excavation, the influence of tunnel excavation on the displacement and stress of surrounding rock is analyzed by using the finite difference software FLAC3D,. In the numerical model, linear elastic material is used for lining and Mohr-Coulomb elastoplastic model is used for soil. First of all, the stability of surrounding rock structure is simulated and analyzed by CRD method, step method, full-section method and so on, combined with Dongzhi County Longtouling Tunnel. The main conclusions are as follows: (1) the displacement settlement of arch roof and arch bottom caused by tunnel excavation is larger, the stress concentration phenomenon appears at the arch waist, and the surrounding rock stress is alleviated by lining support; (2) the displacement settlement caused by CRD excavation is the smallest. Safety is high; (3) the shape of surface settlement trough caused by tunnel excavation is inversely normal distribution curve; (4) with the increase of soil depth, the displacement settlement of soil becomes larger and larger. Secondly, the influence of various factors on the stability of surrounding rock structure and the stability of surrounding rock structure in tunnel excavation with small spacing are analyzed. Finally, the safety prevention and control measures in tunnel construction are expounded from many aspects. The numerical simulation results obtained in this paper can provide theoretical guidance for practical engineering.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455

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