基于连续损伤理论的巷道围岩弹脆性损伤分析

发布时间：2018-12-12 17:03

【摘要】：考虑岩石的脆性损伤特性,引入非线性的岩石脆性损伤本构模型,将损伤演化方程从一维推广到三维,建立岩石损伤变量与脆性参数的关系。将圆形巷道围岩划分为损伤残余区、渐进损伤区和弹性区,采用弹脆性连续损伤理论,对巷道围岩损伤范围及应力进行求解。当巷道周边围岩只出现渐进损伤区时,推导出巷道围岩发生不同程度损伤的极限地应力及损伤半径;当巷道出现损伤残余区时,考虑围岩破坏后仍然具有残余承载能力的特点,推导出巷道围岩损伤区半径及围岩应力的表达式。通过算例分析了岩石损伤程度和脆性强弱对巷道围岩损伤半径及围岩应力场分布的影响,研究结果表明:岩石的脆性对损伤半径的影响跟损伤程度有关,岩石脆性越强,围岩切向应力的峰值越大;岩石损伤程度越大、损伤半径越大,切向应力峰值离巷道壁面越远。
[Abstract]:Considering the brittle damage characteristics of rock, a nonlinear constitutive model of brittle damage of rock is introduced. The damage evolution equation is extended from one dimension to three dimensions, and the relationship between rock damage variable and brittle parameter is established. The surrounding rock of circular roadway is divided into three parts: residual damage zone, progressive damage zone and elastic zone. The damage range and stress of surrounding rock are solved by using the theory of elastic brittle continuous damage. When there is only progressive damage zone around the surrounding rock of roadway, the ultimate ground stress and damage radius of tunnel surrounding rock are deduced. When residual damage zone appears in roadway, considering the characteristics of residual bearing capacity of surrounding rock failure, the expressions of radius and stress of surrounding rock damage zone of roadway are derived. The influence of rock damage degree and brittleness on the radius of rock damage and the distribution of stress field of surrounding rock are analyzed by an example. The results show that the influence of rock brittleness on damage radius is related to the damage degree, and the stronger the rock brittleness is, the stronger the rock brittleness is. The peak value of tangential stress of surrounding rock is larger; The larger the damage degree of rock, the larger the damage radius and the farther the peak value of tangential stress is from the wall of roadway.
【作者单位】：安徽理工大学煤矿安全高效开采省部共建教育部重点实验室;武汉大学土木建筑工程学院;
【基金】：国家自然科学基金(51374013) 高等学校博士学科点专项科研基金(20133415110006)
【分类号】：TD322

【相似文献】