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借助加载控制系统和声发射检测系统,对某矿煤层顶底板砂岩试样进行单轴加载,同时利用声发射检测设备同步进行监测,从而获得砂岩试样在单轴加载条件下的声发射振铃总计数、振铃计数率、各通道幅值、能量、能量率、幅值等声发射特性参数。结果表明:试验砂岩结构组成单一,强度高且表现为脆性;试样的AE能率与声发射事件率吻合,AE能率在岩石破坏前的声发射相对平静期更加明显;相对平静期的特征点可作为岩石破坏的前兆特征点,岩样相对平静期特征点的应力强度百分比为90%~98%,均处于屈服点后的不稳定裂纹扩展阶段。
With loading control system and acoustic emission detection system, the top and bottom sandstone samples of a coal seam are uniaxially loaded, and the acoustic emission detection equipment is used for simultaneous monitoring to obtain the acoustic emission ringing of the sandstone sample under uniaxial loading Total count, ring count rate, the channel amplitude, energy, energy rate, amplitude and other acoustic emission characteristics parameters. The results show that the structure of test sandstone is single in composition, high in strength and brittle. The AE energy of the test specimen agrees well with the acoustic emission event rate, and AE energy is more obvious when the acoustic emission before rock failure is relatively calm. The characteristic points of relative quiet period As a precondition feature point of rock failure, the percentage of stress intensity at the characteristic points of relative calm period of rock samples is 90% ~ 98%, both of which are in the unstable crack propagation stage after yield point.