深埋硬岩隧道开挖稳定性及柔性防护网快速施工工法研究

发布时间：2018-06-12 20:05

本文选题：深埋硬岩隧道 + 岩爆　；参考：《西南交通大学》2017年硕士论文

【摘要】：长大隧道埋深大、延伸长、工程地质复杂,一般作为交通设施建设的控制性工程。随着埋深的不断增加,许多硬岩隧道穿越高地应力区,岩爆问题不可忽视。岩爆是地下工程领域最为强烈的围岩失稳现象之一,伴随着能量的突然释放,具有突发性和强破坏性,直接威胁施工作业人员、设备安全,影响施工进度,已成为地下工程领域世界性难题之一。本文依托巴陕高速米仓山隧道,研究深埋硬岩隧道致灾机理和岩爆预测、防治技术,并结合工程实践,从主动、快速的防护角度优化了米仓山隧道岩爆段施工方案,提出了柔性防护网快速施工工法,大大提高的施工效率和安全性。此研究可为我国类似工程修建提供参考和借鉴意义,主要研究成果如下:(1)通过室内及现场测试,获得了米仓山隧道高地应力硬岩区段围岩基本力学参数及初始地应力特征,在此为基础开展高地应力硬岩隧道开挖扰动特征研究。(2)通过资料调研和理论分析对岩石变形破坏的力学特征展开研究,得出了不同岩石破坏类型之间的转化围压,以此建立围岩应力状态调整路径与围岩破坏类型之间的关系,并分析了岩爆演变过程中围岩应力状态和能量积聚、耗散的特征。(3)采用FLAC3D数值计算软件对隧道开挖过程进行模拟,获得了开挖引起的应力、位移的时空演化规律和围岩扰动特征,并结合单孔声波测试法和UDEC离散元软件研究了米仓山隧道深埋段开挖损伤范围,为支护手段和参数的选择提供依据。(4)提出了岩爆段柔性防护网快速施工工法,引入了柔性防护网支护手段,配合喷锚支护,显现优势互补,对不同等级的岩爆灾害均能起到有效的抵御作用,同时对柔性网支护系统与传统支护方式的施工效率、支护效果、安全性等方面进行了比较分析,研究其经济效益和应用前景。(5)在隧道开挖稳定性以及开挖损伤研究的基础上对高地应力硬岩隧道柔性防护网体系做了参数优化研究,并得出了柔性防护网系统的受荷力学行为和变形特征。
[Abstract]:The long tunnel is a control project of traffic facilities construction because of its large buried depth, long extension and complicated engineering geology. With the increasing of buried depth, many hard rock tunnels pass through high ground stress zone, so the problem of rock burst can not be ignored. Rock burst is one of the most intense rock instability phenomena in underground engineering field. With the sudden release of energy, rock burst is sudden and destructive, which directly threatens construction workers, equipment safety and affects construction progress. It has become one of the worldwide problems in the field of underground engineering. In this paper, the disaster mechanism, rock burst prediction, prevention and control technology of deep buried hard rock tunnel are studied, and the construction plan of rock burst section of Mecangshan tunnel is optimized from active and quick protection angle. The fast construction method of flexible protective net is put forward, which greatly improves the construction efficiency and safety. This study can provide reference for similar engineering construction in China. The main research results are as follows: 1) through indoor and field tests, the basic mechanical parameters and initial geostress characteristics of surrounding rock in high ground stress hard rock section of Micang Mountain Tunnel are obtained. On the basis of this, the disturbance characteristics of high stress hard rock tunnel excavation are studied. (2) through data investigation and theoretical analysis, the mechanical characteristics of rock deformation and failure are studied, and the transformation confining pressure between different rock failure types is obtained. Based on this, the relationship between the stress state adjustment path of surrounding rock and the failure type of surrounding rock is established, and the stress state and energy accumulation of surrounding rock during the evolution of rock burst are analyzed. The dissipative characteristics of surrounding rock stress state are analyzed. The FLAC3D numerical calculation software is used to simulate the excavation process of tunnel. The space-time evolution law of stress and displacement caused by excavation and the disturbance characteristics of surrounding rock are obtained. The damage range of excavation in deep buried section of Micang Mountain Tunnel is studied by using single hole acoustic wave test method and UDEC discrete element software. For the selection of supporting means and parameters, this paper puts forward the fast construction method of flexible protective net in rock burst section, and introduces flexible protective net supporting method, which is combined with shotcrete anchor support, and shows the complementary advantages. All kinds of rockburst disasters can effectively resist, and the construction efficiency, support effect and safety of the flexible mesh support system and the traditional support method are compared and analyzed. On the basis of the stability of tunnel excavation and the study of excavation damage, the parameter optimization of flexible protective net system of high ground stress hard rock tunnel is studied. The mechanical behavior and deformation characteristics of flexible protective net system are obtained.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.4

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