含X型交叉裂隙的岩体力学特性数值分析

Numerical Analysis of the Mechanical Behavior of the Rock Mass with X Type Cross Cracks

基于FLAC^(3D)数值计算软件,首先采用超细单元划分法对计算模型进行剖分以模拟线状裂隙扩展特征,其次采用弹脆性模型及空模型分别刻画岩石及裂隙的力学行为。数值模拟计算结果表明,在两裂隙对称分布的情况下,其夹角及长度对试件破坏模式的影响不大,但是试件强度随裂隙夹角及长度的增加而逐渐减小;当其中一条裂隙长度逐渐增加到与另一条裂隙长度相同时,试件破坏模式也逐渐由较长裂隙控制的单裂隙破坏形式转变为双裂隙同时扩展的对称破坏模式,试件强度也随着裂隙长度的增加而增加;当其中一条裂隙的长度不变,而倾角变化时,试件破坏也呈现单裂隙控制的破坏模式,但相应的试件强度变化规律比较复杂。

Based on numerical calculation software FLAC3D,the superfine element division method was firstly adopted to divide the calculation model to simulate characteristics of linear fracture propagation,and then the elastic-brittle model and null models were used to describe the mechanical behavior of rock and cracks respectively.The numerical results showed that under symmetrical distribution of these two cracks,the angle and length between cracks had little effect on failure mode of sample,but the sample strength decreased with the increase of the angle and length between cracks.When the length of one crack gradually increased to the same with that of the other,the failure mode of sample gradually changed from single-crack-controlling mode controlled by long crack to the two-crack-controlling symmetrical failure mode,and the sample strength also increased with the increase of crack length.Meanwhile,when one crack length remained constant and the inclination changed,the failure of the sample presented a single-crack-controlling mode,but the variation law of the corresponding sample was rather complicated.