强震作用下拱顶背后空洞对隧道结构稳定性影响分析

发布时间：2019-02-16 22:32

【摘要】：隧道衬砌拱顶空洞作为一种常见的隧道衬砌病害形式会对衬砌结构的受力产生较为明显的影响。已有的震害调查记录表明在地震动过程中,空洞位置处隧道衬砌破损较为严重。鉴于我国有大量已建成隧道位于高烈度地震区,因此对地震动作用下衬砌背后空洞对隧道结构变形及安全稳定性的研究就十分必要。论文首先通过数值模拟方法研究了拱顶空洞尺寸对地震动作用下衬砌结构的动力响应影响,然后以汶川大地震中震害较为严重的龙溪隧道为工程背景,对不同地震烈度下拱顶空洞对隧道衬砌结构的地震动力响应进行了分析。最后针对龙溪隧道工程对拱顶空洞加固圈的参数进行了优化分析。本文的主要研究工作及成果如下：(1)对衬砌背后空洞的成因进行了归纳总结,将空洞的成因总结为以下两个主要方面：施工质量原因和设计方案考虑不充分。总结了几种常用的隧道衬砌背后空洞的处治措施,主要包括：回填注浆、锚杆补强、内表面补强、内衬+钢拱架补强、衬砌改建。(2)对拱顶空洞的尺寸对隧道衬砌结构的影响进行了研究,得出结论：隧道衬砌背后拱顶空洞对隧道拱顶衬砌结构的变形、内力及应力有较为明显的影响。随着空洞尺寸的增大,衬砌结构变形显著,空洞位置处衬砌弯矩增大而轴力减小,正应力及剪应力均明显增大。(3)依托工程实例,在不同地震度烈度条件下,对拱顶存在大范围空洞的隧道衬砌结构进行研究分析,得出结论：地震烈度对衬砌结构的正应力、剪应力以及轴力和弯矩具有较明显的影响,对弯矩的增大作用更为明显,可能会造成衬砌大偏心受拉破坏。(4)对隧道空洞位置加固圈参数进行优化分析,得出结论：加固圈刚度能够有效控制衬砌结构的受力并且存在最优值。加固圈厚度对于衬砌结构的受力也有相应的影响,随着衬砌厚度的提高,衬砌结构应力相应减小,弯矩减小而轴力增大,衬砌结构受力更为合理。
[Abstract]:As a common form of tunnel lining diseases, tunnel lining arch cavities have obvious influence on the stress of lining structure. The existing records of earthquake damage investigation show that the tunnel lining damage is serious in the process of ground motion. In view of the fact that a large number of tunnels have been built in our country, it is necessary to study the tunnel structure deformation and safety stability under the action of ground motion. In this paper, the influence of cavity size on the dynamic response of lining structure under ground motion is studied by numerical simulation method, and then the Longxi tunnel, which is seriously damaged by Wenchuan earthquake, is taken as the engineering background. The seismic dynamic response of arch cavities to tunnel lining structures under different earthquake intensity is analyzed. Finally, the parameters of cavity reinforcement ring of arch roof are optimized for Longxi tunnel project. The main research work and results are as follows: (1) the causes of the cavity behind the lining are summarized and summarized into the following two main aspects: the construction quality reasons and the design plan are not fully considered. This paper summarizes several kinds of treatment measures for the cavity behind tunnel lining, including backfilling grouting, reinforcement of anchor rod, reinforcement of inner surface, reinforcement of arch frame of lining steel, etc. (2) the influence of the size of the arch roof cavity on the tunnel lining structure is studied, and the conclusion is drawn that the arch roof cavity behind the tunnel lining has obvious influence on the deformation, internal force and stress of the tunnel arch roof lining structure. With the increase of the cavity size, the lining structure is deformed significantly, the bending moment of the lining at the cavity position increases and the axial force decreases, and the normal stress and shear stress increase obviously. (3) depending on the engineering example, under the conditions of different earthquake intensity, Based on the analysis of tunnel lining structure with large scale cavities in arch roof, it is concluded that seismic intensity has obvious influence on the normal stress, shear stress, axial force and bending moment of lining structure, especially on the increase of bending moment. The large eccentricity of the lining may be damaged by tension. (4) the parameters of the reinforcement ring in the cavity position of the tunnel are optimized and it is concluded that the stiffness of the strengthened ring can effectively control the force of the lining structure and there is an optimum value. With the increase of the thickness of the lining, the stress of the lining structure decreases, the bending moment decreases and the axial force increases, so the stress of the lining structure is more reasonable.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U452.28

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