基于微震监测的矿山岩体强度动态标定方法研究

Research on dynamic calibration method of rock mass strength of mine based on microseismic monitoring

针对矿山岩体强度参数具有随空间和时间动态变化的特点,以石人沟铁矿为例,对地下岩体破坏过程中产生的微震信号进行处理、分析,获得微震监测数据的3个参数(事件数量、能量、事件间距离),结合应力场数值计算结果,分析地下岩体失稳破坏过程的微震数据和应力场演化规律,得到微震数据变量和应力变量之间的对应关系。然后对岩体强度参数进行综合反演,提出基于微震数据和应力场数据的岩体强度参数动态标定方法,并获得地下围岩稳定性的安全储备系数。研究结果表明:微震监测数据结合应力场分析能很好地实现矿山岩体强度参数动态标定,为矿山岩体稳定性动态评价提供有效的量化分析手段。

The strength parameter of the rock mass varies with space and time. Microseismic monitor- ing datum during the rock mass failure of Shirengou iron mine was processed and analyzed and three parameters （microseismic events number, accumulated energy, average distance between the events） were obtained. Combined with numerical calculation result of stress field, correspondence of micro-seismic datum variables and stress variables was built by analyzing evolution law of microseismic monitoring datum and stress field datum with underground rock mass failure. Dynamic calibration method of rock mass strength parameter was proposed based on microseismic monitoring datum by pa-rameter inversion, and safety coefficient of underground rock-mass stability was obtained. The results showed that dynamic calibration of rock mass strength parameter is very achievable by analyzing mi- croseismic monitoring datum and the stress field, thus providing a quantitative analysis method for dy-namic evaluation of rock mass satiability of underground mine.