引入外参数的声发射系统在地应力测量中的应用

Application of Acoustic Emission System with External Parameters into In-situ Stress Measurement

为解决AE法测量地应力时存在的测试精度低、可靠性差、Kaiser效应点不易判别的问题,采用先进的MTS 815材料试验机作为加载设备、PCI-2声发射仪作为声发射信号采集设备,并通过外参数引入技术改造,实现了加载设备和声发射仪二者数据采集的实时同步化,解决了声发射信号特征点与应力值间准确对应关系问题,提高了测试的准确性和精度。在此基础上,分析研究了分级多次循环加载方式下岩石试件声发射信号激发特征与规律,找到了准确获取地应力特征点的方法和波形处理技术,大大提高了测试的可靠性。利用该系统对甘肃白银集团小厂坝铅锌矿深部矿区进行了3个中段15个测点的地应力测试,获得了该矿区原岩应力场分布及变化规律,可为后续安全生产设计提供可靠基础数据。

To deal with the problem of low precision,poor reliability and Kaiser effect point difficult to be distinguished in in-situ stress measurement with traditional AE( acoustic emission) method,an advanced MTS 815 material testing machine and PCI-2 acoustic emission instrument were used respectively as a loading equipment and a AE signals acquisition equipment in the research. A real-time synchronization between the loading device and acoustic emission detector was realized by introducing load and position parameter signals into AE system as external parameters,leading to an improved accuracy and reliability of the measurement. On this basis,the acoustic emission characteristics and rules of rock specimens under hierarchical-times cyclic loading mode was investigated. The obtained new wave-processing technology and method to accurately determine Kaiser effect-point can greatly improve the reliability of measurement.This system was applied in Xiaochangba Lead-Zinc Mine of Baiyin Nonferrous Metals Company in Gansu province and all AE rock specimens were collected from 15 measurement points in 3 different levels of the deep mine area,with the distribution and variation rules of the initial stress field obtained for this mine,which would be regarded as reliable base data for its following safety production design.