裂隙岩体损伤局部化分析

Analysis of Damage Localization in Crack Weakened Rock Mass

裂隙岩体损伤局部化与裂隙扩展状态密切相关,裂隙扩展到一定长度后裂隙的扩展状态发生分叉,一部分裂隙继续扩展,另一部分裂隙停止扩展。裂隙岩体损伤局部化是由裂隙扩展状态分叉产生的,损伤局部化起始位置也取决于裂隙扩展状态。通过对多裂隙扩展状态的分叉分析,得到了含矩形分布裂隙岩体损伤局部化弯折裂纹临界扩展长度及临界应力。根据系数矩阵的特征值与特征向量,确定了裂隙岩体损伤局部化的位置,而且考虑了裂隙之间的相互作用。最后,通过算例分析得到了裂隙岩体损伤局部化临界应力与裂隙列间距、行间距、围压和原生裂隙倾角的关系。

Damage localization in crack weakened rock mass is closely related to the crack growth pattern.Bifurcation of the alternative evolution of cracks occurs when the cracks grow to some extent,then some cracks keep on growing while other ceased evolving.It is found that damage localization in crack weakened rock mass is caused by bifurcation of the crack growth pattern,and the initial location is also determined by the crack growth pattern.Based on the analysis on the bifurcation of crack growth pattern,the critical length of wing crack and the critical stress of damage localization in crack weakened rock mass are obtained.Subsequently,the onset location of damage localization is determined by using the eigenvalue and eigenvector of coefficient matrix,and crack interaction is also taken into account in this model.Finally,the relationship between the interval between columns and rows,the orientation of crack,confining stress and the critical stress of damage localization is defined in the example.