锚固圆形隧洞解析解及可靠性分析

发布时间：2018-05-23 13:24

本文选题：圆形隧洞 + 弹塑性解析解　；参考：《河南理工大学》2014年硕士论文

【摘要】：隧洞是地下工程结构的重要组成部分之一,对无支护和锚杆支护两种状态下的圆形隧洞进行分析是解决实际工程问题的基础。弹性分析或者以理想弹塑性材料为假设的塑性分析都太过于保守,而经典的微观力学对于锚杆支护状态下隧洞的求解过于复杂,同时隧洞可靠性分析中失稳判据的确定很模糊,这些都是隧洞稳定性分析、设计与施工中需要解决的问题,因此,用新的方法和思路来分析隧洞力学状态及其稳定性显得尤为必要。针对上述问题,本文研究了锚杆支护前后隧洞的应力、位移和塑性区的特性并给出了相应的表达式。首先,在静水压力状态下,岩石表现为弹脆塑性材料模型,采用Mohr-Coulomb线性屈服准则和非关联流动法则,推导了无支护状态下圆形隧洞的弹塑性解析新解;在此基础上,通过均匀化方法,从宏观尺度将高密度支护模式下的岩石和锚杆复合体考虑成均匀连续、强度参数增强的等效材料,定义能够反映隧洞支护参数的锚杆密度因子,推导得到了等效弹性模量,等效粘聚力和等效内摩擦角的表达式,建立了锚杆支护状态下圆形隧洞的弹塑性解析解,并将本文结果与前人研究结果及数值结果进行了比较分析,对比了锚杆支护前后圆形隧洞的塑性区半径和塑性区位移,结果表明本文解析解简单可靠,适用于准确分析隧洞应力和位移状态;最后结合可靠性理论,分析了隧洞在支护前后的可靠度指标与破坏概率,结果表明锚杆支护对隧洞的位移限制效果明显,可显著提高隧洞的可靠性。
[Abstract]:Tunnel is one of the important parts of underground engineering structure. The analysis of circular tunnel without support and bolt support is the basis of solving practical engineering problems. Both elastic analysis and plastic analysis based on ideal elastic-plastic material are too conservative, and the classical micromechanics is too complicated to solve the tunnel under the condition of bolt support, and the determination of the instability criterion in the reliability analysis of the tunnel is very fuzzy. These are the problems to be solved in tunnel stability analysis, design and construction. Therefore, it is necessary to use new methods and ideas to analyze tunnel mechanical state and its stability. In view of the above problems, the characteristics of stress, displacement and plastic zone of the tunnel before and after bolting are studied and the corresponding expressions are given. Firstly, under hydrostatic pressure, the rock appears to be an elastic-brittle plastic material model. By using the Mohr-Coulomb linear yield criterion and the uncorrelated flow rule, a new elastic-plastic analytical solution for a circular tunnel without support is derived. Through the homogenization method, the rock and bolt complex under the high density support mode is considered as an equivalent material with uniform and continuous strength parameters from the macroscopic scale, and the anchor density factor which can reflect the support parameters of the tunnel is defined. The expressions of equivalent modulus of elasticity, equivalent cohesive force and equivalent angle of internal friction are derived, and the elastic-plastic analytical solution of circular tunnel under bolting condition is established, and the results of this paper are compared with those of previous studies and numerical results. The plastic zone radius and plastic zone displacement of circular tunnel before and after bolting are compared. The results show that the analytical solution in this paper is simple and reliable, which is suitable for accurate analysis of stress and displacement state of tunnel. The reliability index and failure probability of the tunnel before and after supporting are analyzed. The results show that the bolt support has obvious effect on limiting the displacement of the tunnel and can obviously improve the reliability of the tunnel.
【学位授予单位】：河南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU45

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