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考虑裂隙的连通率、间距、孔隙基质和裂隙材料在表征单元(REV)中的体积分数,认为双重孔隙介质的黏聚力Nc及内摩擦角Nφ是随方向变化的,从而进一步完善相应的确定方法,并证明所建立的Nc,Nφ计算式是合理的。在独自开发的二维弹塑性有限元程序中引入求得的Nc,Nφ,针对一个断面为矩形的地下洞室,拟定岩体中裂隙的连通率及间距不同的2种情况,进行数值模拟,考察围岩中的变形、应力和塑性区的分布与变化。所得结果显示:随着岩体裂隙连通率的增加,岩体的破碎程度变严重,黏聚力和内摩擦角下降,围岩中位移增大,主应力等值线发生明显变化,塑性区加速扩展,并且位移、应力和塑性区的分布由对称变为不对称,围岩的各向异性表现越发显著;而随着裂隙间距的变大,围岩的动态与裂隙连通率增加时正好相反。
Taking into account the connectivity, spacing, volume fraction of pore matrix and fracture material in the characterization unit (REV), the cohesion Nc and the internal friction angle Nφ of the dual-porosity media are assumed to vary with direction, so as to further improve the corresponding determination Method, and proved that the established Nc, Nφ formula is reasonable. The two-dimensional elastic-plastic finite element program developed by ourselves is introduced into Nc and Nφ. For an underground caverns with a rectangular section, two cases of different connection rates and pitches of cracks in the rock mass are formulated, Investigate the deformation, stress and plastic zone distribution and changes in the surrounding rock. The results show that with the increase of rock fissure connectivity, the crushing degree of rock mass becomes more serious, the cohesion and internal friction angle decrease, the displacement of surrounding rock increases, the principal stress contours change obviously, and the plastic zone accelerates And the distribution of displacement, stress and plastic zone changed from symmetry to asymmetry, and the anisotropy of surrounding rock became more and more pronounced. With the increase of crack spacing, the dynamic of surrounding rock was exactly the opposite when the fracture connectivity increased.