单轴压缩下粉砂岩声发射事件与撞击对比试验研究

Experimental study on the acoustic emission characteristic parameters of siltstone at uniaxial compression

为更深入地研究岩石受载失稳过程中声发射(AE)撞击和事件参数对岩石内部损伤的响应关系,试验采用PCI-2全数字化声发射信号采集分析系统及TAW-2000型微机伺服岩石力学实验系统,对粉砂岩进行单轴加载声发射监测,观察粉砂岩在单轴加载过程中声发射事件参数与撞击参数的变化特征。通过参数对比分析,发现事件参数与撞击参数对粉砂岩破坏表征的优劣性,得出如下结论:AE撞击参数较AE事件参数变化趋势明显,更能体现岩石内部损伤过程;在岩石受载中期声发射活动相对前后期较为平稳且各参数值也相对偏低;在粉砂岩未处于失稳破坏阶段时,撞击数与事件数的变化趋向相同;但受载末期撞击数迅速增加而事件数很少,两者变化呈不同趋向,其直观地反映出岩石内部裂隙发展过程。

To intensively study the effects of acoustic emission（AE）hit and event parameters in rock loading rupture process,physical experiments on the uniaxial compression of siltstones were carried out using PCI-2digital AE signal collection/analysis system and TAW-2000 computer servo rock mechanics system,and the corresponding variation characteristic of the AE parameters upon loading was studied.The results show that AE hit parameters have more features and can better reflect the rock damage process than the AE event parameters.In the middle stage of the rock loading,AE activity is relatively stable and the parameter values are relatively low.Before the siltstone instable destruction stage,the hit and the event have the same variation tendency.However,at the end of the loading,the hit number increases suddenly while that of the event decreases,this difference reflects intuitively the rock fracture development.