地铁隧道穿越地裂缝引起的地表沉降规律及控制技术研究

发布时间：2018-05-12 05:00

本文选题：地裂缝 + 地表沉降　；参考：《西安科技大学》2017年硕士论文

【摘要】：地裂缝是西安地铁隧道建设过程所必须面临的关键难题,如何正确处理地裂缝问题对地铁隧道安全稳定的影响将是地铁建设过程中的关键所在,因此,进行地铁隧道穿越地裂缝诱发的地表沉降规律及控制技术研究意义重大。论文依托西安地铁1号线半坡～纺织城区间工程,采用理论分析、数值模拟和现场监测相结合的方法对隧道穿越地裂缝引起的地表沉降规律进行研究,提出了地表沉降控制措施,指导了工程实践。论文主要工作如下:(1)地裂缝灾害表现形式主要表现为周期性、有限性、方向性、缓变性和累进性、非均衡性和非对称性以及地裂缝灾害的不可抗拒性。地铁隧道无论从荷载还是变形方面都与无地裂缝时表现出较大差异,主要表现在两个方面:①作用于隧道的荷载发生改变;②隧道底面出现了脱空现象。(2)通过对作用于隧道荷载的理论研究,建立了隧道穿越地裂缝的计算模型,并将地裂缝作用下隧道的受力过程分为沉降初期、脱空发展阶段和完全脱空阶段三个阶段。(3)运用FLAC3D软件对隧道穿越地裂缝引起的地表沉降规律进行研究,计算结果表明:隧道拱顶竖向和地表沉降值远远超过规范允许值,隧道上方的电建小区楼房基础变形很大,易造成墙体倾斜甚至倾覆,必须采取合理有效的控制措施。(4)结合西安地铁1号线半坡～纺织城区间暗挖段工程特点,从隧道结构设计、地层加固设计和开挖步骤三方面提出了穿越地裂缝隧道引起的地表沉降控制技术措施。(5)给出了现场监测方案设计,并完成了现场实测。通过分析实测监测数据,结果表明,采取文中提出的控制措施后,整个隧道穿越地裂缝的施工过程能够确保隧道上方道路变形在允许范围之内和电建小区大楼变形得到有效控制,从而保证了隧道上方道路的正常使用和临近楼房的安全稳定;表明提出的控制措施合理且有效。
[Abstract]:Ground fissures are the key problems that must be faced in the process of subway tunnel construction in Xi'an. How to correctly deal with the influence of ground cracks on the safety and stability of subway tunnel will be the key point in the process of subway construction. It is of great significance to study the law and control technology of ground subsidence induced by ground fissures in subway tunnel. In this paper, based on the project between the slope of Xi'an Metro Line 1 and the textile city, the ground subsidence law caused by the tunnel passing through the ground fissure is studied by the methods of theoretical analysis, numerical simulation and field monitoring. The control measures of surface subsidence are put forward and the engineering practice is guided. The main work of this paper is as follows: (1) the main forms of ground fissure disasters are periodicity, finiteness, directionality, slow variation and progression, disequilibrium and asymmetry, and irresistibility of ground fissures. The subway tunnel is different from the ground crack in terms of load and deformation, mainly in two aspects: the change of the load acting on the tunnel by 1: 1; (2) through the theoretical research on the load acting on the tunnel, the calculation model of tunnel crossing ground fissure is established, and the stress process of the tunnel under the action of ground crack is divided into the initial stage of settlement. The ground subsidence law caused by tunnel crossing ground fissure is studied by using FLAC3D software. The calculation results show that the vertical and surface settlement values of tunnel vault are far more than the allowable value of the code. The building foundation of electric construction district above the tunnel is very large deformation, easy to cause wall incline or even overturn, must take reasonable and effective control measures. 4) combined with Xi'an Metro Line 1 semi-slope ~ textile urban area between the subsurface excavation engineering characteristics, from the tunnel structure design, it is necessary to take reasonable and effective control measures. The ground subsidence control measures caused by ground fissure tunnel are put forward from three aspects of ground reinforcement design and excavation steps. The design of site monitoring scheme is given and the field measurement is completed. Through the analysis of the measured monitoring data, the results show that, after taking the control measures proposed in this paper, The whole construction process of the tunnel through the ground crack can ensure that the deformation of the road above the tunnel is within the allowable range and the deformation of the building in the electric building can be effectively controlled, thus ensuring the normal use of the road above the tunnel and the safety and stability of the adjacent building; The results show that the proposed control measures are reasonable and effective.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U231.3;U456.3;P642.26

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