基于解析法的深埋铁路隧道二次衬砌支护时机研究

发布时间：2018-06-20 23:02

本文选题：深埋隧道 + 解析法　；参考：《山东科技大学》2017年硕士论文

【摘要】：铁路隧道开挖深度的不断增加、地压大、地质条件复杂、缺乏正确的理论指导、设计与施工工艺存在较大的盲目性,造成隧道衬砌坍塌现象常常发生,已成为隧道建设中亟待解决的重大技术难题。国内外对隧道衬砌坍塌破坏的研究多集中在支护结构受力机理、稳定性问题以及支护结构破坏后的重新修复方面,针对隧道二次衬砌受力机理及稳定性的研究成果存在较大的局限性,并且基于解析法的二次衬砌支护最佳时机问题则少有研究。针对城际铁路隧道二次衬砌的合理支护时机进行分析,以青岛“蓝色硅谷”城际铁路崂山隧道工程为依托,通过现场监控量测数据,以及大型有限差分软件FLAC3D对隧道开挖支护进行模拟分析,并最终将现场实测结果以及模拟分析结果相结合,具体分析隧道二次衬砌的合理支护时机。本文对城际铁路隧道二次衬砌的施作时机主要进行了以下研究:(1)通过理论分析,详细分析深埋隧道二次衬砌受荷类型,分析在不同荷载作用下,二衬结构的受荷特征;分析二衬结构在荷载作用下的破坏特征,特别是二衬裂缝的演化过程及分布规律,根据不同类型、不同部位的裂缝演化特征,分别从设计、施工、材料等方面影响隧道深埋隧道变形及破坏的影响因素。(2)分析了对衬砌施工产生作用的因素,详细介绍了确定二次衬砌支护时机的机理和方法步骤,并从支护抗力、变形速率、位移变化三个方面分析了衬砌合理支护时机的原理;考虑各种因素的影响,建立符合工程实际情况最佳支护时机的解析公式,在围岩参数已知的情况下,可以计算出隧道洞壁周边变形量,并与实际工程中的监测到的围岩变形量数据进行对比分析,确定了二次衬砌支护的时机,从理论上解决了深埋隧道二次衬砌的支护时机问题。(3)通过有限元FLAC3D分析软件,模拟了崂山隧道的支护,在模拟过程中,分析了在不同应力释放率下隧道衬砌的受力情况及隧道围岩的变形情况,得到了崂山隧道二次衬砌的最佳支护时机,利用监控量测技术,研究了隧道开挖过程中,隧道周边收敛和拱顶沉降,并与FLAC3D数据进行比较,推算出了二次衬砌的合理施作时机,验证了解析公式的正确性。
[Abstract]:The excavation depth of railway tunnel is increasing continuously, the ground pressure is high, the geological condition is complex, and lack of correct theoretical guidance, the design and construction technology is more blind, and the phenomenon of tunnel lining collapse often occurs. It has become an important technical problem to be solved in tunnel construction. The research of tunnel lining collapse damage at home and abroad is mainly focused on the mechanical mechanism, stability of the support structure and the re-repair after the failure of the support structure. The research results on the mechanism and stability of secondary lining of tunnel are limited, and the optimal time of secondary lining support based on analytic method is seldom studied. Based on the analysis of the reasonable supporting time of the secondary lining of the inter-city railway tunnel, based on the Laoshan tunnel project of Qingdao "Blue Silicon Valley" inter-city railway, the field monitoring and measuring data are adopted. And the large-scale finite-difference software FLAC3D is used to simulate and analyze the tunnel excavation support. Finally, combining the field measured results with the simulation analysis results, the reasonable supporting time of the secondary lining of the tunnel is analyzed. In this paper, the following research on the timing of secondary lining of inter-city railway tunnel is carried out: (1) through theoretical analysis, the types of secondary lining of deep buried tunnel are analyzed in detail, and the loading characteristics of secondary lining structure under different loads are analyzed. The failure characteristics of two-liner structure under load, especially the evolution process and distribution law of two-liner cracks are analyzed. According to the evolution characteristics of cracks in different types and different parts, the design and construction are carried out respectively. The factors influencing the deformation and failure of deep buried tunnel are analyzed, the mechanism and method of determining the time of secondary lining support are introduced in detail, and the resistance and deformation rate of secondary lining are introduced in detail. This paper analyzes the principle of reasonable supporting time of lining in three aspects of displacement variation, establishes the analytical formula of optimum supporting time according to the actual situation of engineering, considering the influence of various factors, and when the surrounding rock parameters are known, The surrounding deformation of tunnel wall can be calculated and compared with the deformation data of surrounding rock monitored in actual engineering, and the time of secondary lining support is determined. The problem of supporting opportunity of secondary lining of deep buried tunnel is solved theoretically. The support of Laoshan tunnel is simulated by finite element software FLAC3D. In the process of simulation, The stress situation of tunnel lining and the deformation of tunnel surrounding rock under different stress release rates are analyzed. The optimum supporting time for the secondary lining of Laoshan tunnel is obtained. The monitoring and measurement technology is used to study the excavation process of the tunnel. Compared with the FLAC3D data, the reasonable timing of the secondary lining is calculated, and the correctness of the analytical formula is verified.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.91

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