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选取典型深部矿山脆性岩石进行加卸载岩石力学试验,对复杂应力路径下脆性岩石的力学及破裂特征进行对比分析。采用声发射设备对破裂过程中声发射演化特征进行研究。研究表明,岩石的力学性质和变形特性与围压有密切的关系,围压的增加使围岩逐渐由脆性破坏向延性破坏过渡;对试件进行卸围压操作,容易造成岩石的突然破坏,同时造成了岩石强度的降低;由破裂形式素描图可知,卸载造成破坏更加剧烈,岩石表面出现大量竖向裂纹,卸载往往造成岩石的复合拉压破坏,且卸载破坏的的声发射计数率远远加载破坏。卸载破坏过程中,岩石声发射演化过程总体分为3个阶段,包括峰前平静期、活跃期及峰后平缓期,每个时期都有一个应力、应变及振铃计数临界值,需要通过大量试验及现场测试。
Select the typical deep mine brittle rock loading and unloading rock mechanics test, the mechanics and rupture characteristics of brittle rock under complex stress path are compared and analyzed. Acoustic emission equipment was used to study the evolution of acoustic emission during rupture. The results show that the mechanical properties and deformation characteristics of rock are closely related to the confining pressure. The increase of confining pressure causes the gradual transition from brittle failure to ductile deformation. The unloading and confining pressure operation of the specimen can easily lead to the sudden destruction of the rock, At the same time, the strength of the rock decreases. From the sketch map of the rupture, it can be seen that the damage caused by unloading is more severe, and a large number of vertical cracks appear on the rock surface. Unloading often results in compound tension and compression failure of the rock. Loading damage. During the process of unloading and destruction, the rock acoustic emission evolution process is generally divided into three stages, including the pre-peak quiet period, active period and post-peak flat period. Each period has a critical value of stress, strain and ring count, Test and field test.