单轴压缩下软硬互层岩石破裂过程的离散元数值分析

发布时间：2019-08-16 09:56

【摘要】：采用离散单元法研究了软硬互层岩石材料在不同层面倾角条件下的单轴压缩破坏过程,并结合复合岩体破坏的理论分析,求解了交界面上的界面黏结应力。考虑弱相岩石和弱界面的影响提出了软硬互层岩体的强度曲线。结果表明:随着层面倾角的增大,岩石的单轴抗压强度和弹性模量,以及总裂纹数量呈先减小后增大,层面倾角90?时的强度甚至超过了0?时的强度。裂纹数量以剪切裂纹为主,而拉伸裂纹较少。互层岩体由于层间力学属性不同,极有可能在交界面处引起应力集中,使得在交界面附近裂纹最先萌生,裂纹进一步向交界面两侧岩体中扩展,从而引起宏观裂纹的出现,最终引起岩体的破坏。裂纹的萌生位置和扩展模式直接决定了岩体的最终破裂形态。层面倾角?=45°~75°的试件主要发生沿材料交界面的滑动破坏。层面倾角?=0°和?=90°的试件主要发生拉伸破坏。层面倾角?=15°和?=30°的试件呈现弱相材料的拉伸破坏与沿层面滑动相结合的复合破坏。建立的界面黏结应力表明界面的应力状态由弱相材料控制。
[Abstract]:The uniaxial compression failure process of soft and hard interbedded rock materials under different dip angles is studied by using discrete element method. Combined with the theoretical analysis of composite rock mass failure, the interfacial bonding stress on the interface is solved. Considering the influence of weak phase rock and weak interface, the strength curve of soft and hard interbedded rock mass is put forward. The results show that with the increase of plane dip angle, the uniaxial compressive strength and elastic modulus of rock, as well as the total number of cracks decrease at first and then increase, and the plane inclination angle is 90? The intensity of the time is even more than 0? The strength of the hour. The number of cracks is mainly shear cracks, but the tensile cracks are less. Because of the different mechanical properties of interlayer rock mass, it is very likely to cause stress concentration at the interface, which makes the crack initiate first near the interface, and the crack propagates further into the rock mass on both sides of the interface, which leads to the appearance of macroscopic crack and finally the failure of rock mass. The crack initiation position and propagation mode directly determine the final fracture shape of rock mass. The sliding failure along the interface of the material mainly occurs when the plane inclination angle is 45 掳~ 75 掳. Tensile failure occurs mainly in specimens with dip angle of 0 掳and 90 掳. The specimens with dip angle of 15 掳and 30 掳show the tensile failure of weak phase material and the composite failure of sliding along the plane. The established interfacial bonding stress indicates that the stress state of the interface is controlled by the weak phase material.
【作者单位】：东京大学土木工程系;重庆大学煤矿灾害动力学与控制国家重点实验室;大连理工大学工程力学系;
【基金】：国家自然科学基金项目(10772205)
【分类号】：TU45

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