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通过在类岩石模型材料中预制特定倾角和尺寸的断续贯通2条裂隙试样,以MTS常规三轴压缩试验为手段,研究2条裂隙试样的破坏特性。主要研究成果:(1)2条裂隙岩样的宏观破裂迹线由次生共面裂纹、反翼裂纹和翼裂纹3种类型组成;(2)2条预制裂隙之间的贯通有拉伸贯通、剪切贯通、一预制裂隙共面扩展裂纹与另一预制裂隙的反翼裂纹扩展连接贯通及两预制裂隙无贯通4种形式;(3)2条裂隙岩样在三向受力条件时,反翼裂纹为主要裂纹形式,它影响着试样的最终破坏形式;(4)2条预制裂隙的排列形式和围压大小决定着试样的破坏模式;(5)2条裂隙试样的轴向应力–轴向应变曲线表现出多峰值的特点,变形特性为从低围压下的脆性向高围压下的延性转化;(6)2条裂隙试样在高围压状态时,裂隙岩石的扩容现象不明显甚至完全消失;(7)2条裂隙试样的轴向应力–轴向应变曲线与裂纹的萌生、扩展、贯通具有密切的关系。研究成果能为含节理或断层的地下工程开挖、支护设计及其稳定性分析提供理论参考。
The fracture characteristics of two fissure samples were studied by means of conventional MTS triaxial compression test by intermittently penetrating two fissure specimens with specific inclination and size prefabricated in the rock-like model material. The main research results are as follows: (1) The macroscopic rupture trace of two fractured rock samples consists of three types of secondary coplanar crack, anti-wing crack and wing crack. (2) , Shear through, a prefabricated crack coplanar expansion crack connected with another prefabricated anti-wing crack propagation through and two non-through prefabricated cracks through four forms; (3) two fractured rock samples in the three-way stress conditions, (4) The arrangement of two prefabricated fractures and the confining pressure determine the failure mode of the specimen; (5) The axis of the two fissured specimens, which is the major crack, affects the final failure mode of the specimen; The stress-axial strain curve showed multi-peak characteristics, and the deformation characteristics were ductile transition from low confining pressure to high confining pressure. (6) In the condition of high confining pressure, the fractured rock (7) The axial stress-axial strain curves of two cracked specimens are closely related to the initiation, propagation and penetration of cracks. The research results can provide theoretical reference for excavation and support design and stability analysis of underground engineering with joints or faults.