声发射和变形场联合监测试验研究

为探究工程岩体在声发射和变形场联合监测下破裂失稳的特征,分析两者与岩石破裂失稳的内在联系,进行了片麻岩单轴压缩试验,提供一种更全面的预警方法.研究结果如下:声发射累计振铃计数和变形场应变均方差两个参数曲线启动点出现时间差距不大,预警点出现时间差距较大,总体上声发射比变形场更早监测到破裂信息;声发射累计振铃计数曲线和应变...

Experimental study on combined acoustic emission and deformation field monitoring

The purpose of this paper is to explore the characteristics of fracture instability of engineering rock mass under combined acoustic emission and deformation field monitoring and analyze the internal relationship between them and rock fracture instability.In this paper, the uniaxial compression test of gneiss is carried out to provide a more comprehensive method for early warning.The results are as follows: there is little time difference between the start points of the acoustic emission cumulative ringing count and the strain mean square deviation of the deformation field, while there is a big time difference between the warning points. On the whole, the acoustic emission detects the rupture information earlier than the deformation field.The cumulative acoustic emission ringing count curve and strain mean square deviation curve can give warning when the near vertical slope rises sharply for the first time, indicating that the rock is about to collapse.The cumulative acoustic emission ringing count curve increased by 20%-50%, accounting for 34.65% on average, and the strain mean square deviation curve increased by 25%-65%, accounting for 41.15% on average.In terms of the early warning of rock fracture and instability, the temporal acoustic emission is earlier than the deformation field, but the deformation field can be used to observe the rock surface crack evolution in real time.By combining the two monitoring methods, the rupture of engineering rock mass can be understood more comprehensively, and the theoretical basis for stability control and prevention of engineering rock mass can be provided.