基于能级-频度分析的微震能量预警指标优化

Optimization of microseismic energy early-warning index based on energy level and frequency analysis

单个事件能量、日总能量是矿井最常用的两个微震预警指标,但其初始值设置往往不够准确,需结合大量监测数据进行优化。以葫芦素21103工作面的实际监测数据为基础,对初始指标的预警效能进行了分析,分析表明:单个事件能量的强冲击危险指标、日总能量的中等及强冲击危险指标初设不合理。进一步发展了基于能级-频度分析进行微震预警指标优化的方法:首先研究了矿井尺度下微震事件的能级-频度曲线,并将其划分为指数分布段、线性分布段和离散分布段;然后,取线性分布段末两次偏移点的能级作为矿井中等与强冲击危险的预警指标,取斜率偏移点的能级作为弱冲击危险的预警指标;最后,对基于统计数据划分的日总能量指标的能级-频度合理性进行检验。最终得到的新预警指标预警准确率明显提高,对4起大能量事件的预警基本准确。

Single event energy and daily total energy are the two microseismic early warning indicators most commonly used in coal mines, but their initial values are often not accurate enough and need to be optimized combining with a large number of monitoring data. Based on the actual monitoring data of the 21103 working face in Hulusu Coal Mine, the early warning effectiveness of the initial index is analyzed. The analysis shows that the initial design of strong burst risk index of single event energy, moderate and strong burst risk index of daily total energy is unreasonable. The optimization method of microseismic early-warning index based on energy level and frequency analysis is developed: firstly, the energy level frequency curve of microseismic events at mine scale is studied and divided into exponential distribution section, linear distribution section and discrete distribution section;secondly, the energy level of the last two migration points of linear distribution section is taken as the early warning index of medium and strong rockburst risk, the energy level of the slope shift point is taken as the early warning index of weak rockburst risk. Finally, the rationality of the energy level and frequency of the total daily energy index divided based on the statistical data is tested. The accuracy of the new early-warning index is significantly improved, and the early-warning of four high energy events is basically accurate.