基于PFC3D的破裂岩样力学行为及其影响因素研究

Study of Mechanical Behavior of Fractured Rock Samples and Its Influential Factors Using PFC3D Software

破裂区围岩是地下工程变形的主因,也是支护的主体,对围岩整体稳定的影响非常严重.根据已有室内破裂岩样的单轴、三轴试验结果,基于PFC3D软件进行数值模拟,研究不同围压下破裂岩样的力学行为,并对其主要影响因素进行了分析.最后,通过灰色关联分析法研究了各影响因素的敏感性,发现破裂程度对破裂岩样力学行为影响最严重,岩性和加载速率影响次之,三者均是主要影响因素.而破裂面方向的影响稍大于孔隙量,孔隙量影响最小,二者为次要影响因素.因此,以后的研究中建议把破裂程度、岩性及加载速率的影响作为主要目标.

The fractured surrounding rock is the primary cause of the deformation of surrounding rock and the main part of the support for the underground engineering. It has great influences on the monolithic stability of the surrounding rock. At present, there are few researches on the fractured rock mass and systematic studies on its mechanical behavior. Based on the results of uniaxial and triaxial laboratory experiments for fractured rock samples, the particle flow code in 3 dimensions（PFC3D） software is used to simulate the fractured rock samples and its mechanical behavior under different confining pressures. Furthermore, major influential fac tors are also investigated. The sensitivity of every influential factor is studied by grey correlation analysis re spectively. The results show that the degree of rupture has the greatest impact on the mechanical behavior of fractured rock samples, followed by the lithology and the loading rate, all of the three are the main influential factors. Moreover, the influence of the direction of fracture plane is slightly larger than that of the pore vol ume which is minimum; they are secondary factors. Thus, it is suggested that the influences of the degree of rupture, the lithology and the loading rate should be the principal target of the future research.