基于非线性损伤的巷道开挖面附近围岩变形及支护研究

发布时间：2018-03-05 03:31

本文选题：损伤特性　切入点：非线性软化　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：巷道开挖过程中,围岩内应力重新分布并产生变形破坏,为保证巷道的稳定及正常使用,有必要对其稳定性及有效支护进行研究。本文考虑巷道围岩的非线性力学响应及岩体的损伤破坏特性,从岩体内部微裂纹产生和扩展的损伤机理出发,建立岩体的非线性损伤本构模型("直线-曲线-直线"本构模型),求得等压荷载下圆形巷道围岩不同区域半径及位移的计算公式,并求出围岩平衡方程。同时,引入巷道开挖面空间效应原理,提出分步联合支护方案控制围岩变形,建立围岩-支护耦合作用的力学模型,并求得围岩-支护相互作用实时解析解和相互作用平衡力。在此基础上,通过算例分析初始损伤D0、软化程度系数β和损伤比例系数k对塑性损伤区、流动损伤区分布范围、应力分布及位移的影响,也进一步分析了支护时机和支护强度对支护作用效果的影响。文中以刘庄煤矿井底车场的巷道群为研究工程背景,利用3DEC数值模拟软件分析不同支护时机(模拟支护结构距离开挖面分别0.2m、1m和2m)和不同支护强度(模拟三种支护方案)条件下对围岩变形的控制效果,然后现场监测巷道围岩表面和深部岩体的位移量,监测结果验证了研究成果的正确性。本文的研究成果可以为巷道的稳定性分析提供理论依据和为有效支护的确定提供一定的参考。
[Abstract]:In the course of tunnel excavation, the stress in surrounding rock is redistributed and deformed and destroyed, in order to ensure the stability and normal use of roadway, It is necessary to study its stability and effective support. In this paper, considering the nonlinear mechanical response of roadway surrounding rock and the damage and failure characteristics of rock mass, starting from the damage mechanism of micro-crack generation and propagation in rock mass, The nonlinear damage constitutive model of rock mass ("straight-curvilinear" constitutive model) is established. The calculation formulas of radius and displacement of surrounding rock in different regions of circular roadway under isobaric load are obtained, and the balance equation of surrounding rock is obtained. Based on the principle of spatial effect of excavation surface of roadway, a mechanical model of the coupling effect of surrounding rock and support is established by adopting the method of step by step combined support to control the deformation of surrounding rock. The real time analytical solution of the interaction between surrounding rock and support and the equilibrium force of the interaction are obtained. Based on this, the distribution of initial damage D0, softening degree coefficient 尾 and damage proportional coefficient k to plastic damage zone and flow damage zone are analyzed. The influence of stress distribution and displacement on the supporting effect is also analyzed. In this paper, the roadway group in the bottom pit of Liuzhuang coal mine is taken as the engineering background. Using 3DEC numerical simulation software to analyze the control effect of surrounding rock deformation under the conditions of different timbering time (0.2m-1 m and 2ms from the simulated support structure to the excavated surface) and different supporting strength (simulating three support schemes). Then the displacement of surrounding rock surface and deep rock mass of roadway is monitored on site. The monitoring results verify the correctness of the research results, which can provide a theoretical basis for the stability analysis of roadways and a certain reference for the determination of effective support.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD322;TD353

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