论文部分内容阅读
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。
Discrete element method was used to study the uniaxial compressive failure process of soft and hard interbedded rock materials under different bedding inclination conditions. Combined with the theoretical analysis of composite rock mass failure, the interfacial bonding stress was solved. Taking into account the influence of weak phase rock and weak interface, the intensity curve of soft and hard interbedded rock mass is proposed. The results show that the uniaxial compressive strength, elastic modulus and total crack number of the rock first decrease and then increase with the increase of bedding inclination, and the strength at 90 ° inclination even exceeds the strength at 0 ° . The number of cracks is dominated by shear cracks and the tensile cracks are less. Due to the different mechanical properties between layers, the inter-layer rock is likely to cause stress concentration at the interface, which leads to the initiation of cracks in the vicinity of the interface. The cracks further extend to the rock masses on both sides of the interface, causing the occurrence of macro-cracks , Eventually causing the destruction of rock mass. Crack initiation and expansion mode directly determine the final rupture of rock mass. The specimen with dip angle = 45 ° ~ 75 ° mainly occurred the sliding failure along the interface of material. Tensile failure mainly occurred in specimens with dip angles = 0 ° and? = 90 °. Tensile specimens with dip angles = 15 ° and? = 30 ° exhibited tensile failure of weak phase materials and composite failure combined with sliding along the plane. The established interface bond stress indicates that the interface stress state is controlled by the weak phase material.