应用于采空区失稳预报的声发射差量比指标

Application of Acoustic Emission Differential Ratio Indicator in Instability Prediction of Mining-out Area

鄂东地区中小型矿山数量众多,采空区失稳事故频发,实现采空区准确有效的预警预报已成为鄂东地区重点研究内容之一。结合鄂东地区声发射监测应用现状,提出差量比指标,该指标综合考虑了一段期间声发射大事件、总事件及能率3项参数,有效减少外界干扰、地质条件不同及采空区结构差异造成的声发射监测参数波动影响。通过对比采空区岩体失稳声发射参数累计值的变化,得出了对应的声发射差量比指标的一般变化规律及失稳前兆特征,利用声发射差量比指标,不仅能合理有效分析采空区稳定性状态,还能简单准确地根据差值比前兆特征对采空区失稳时间进行预测。将声发射差值比指标应用于鄂东地区普民铁矿采空区稳定性分析,预测评判结果与现场实际情况一致,说明该指标评判方法具有一定的适用性和合理性。

There are numerous small or medium-sized mines in the eastern Hubei where instable accidents of mining excavations frequently happened.How to accurately and effectively analyze and predict the stability of mining-out area has been one of the important issues.Based on the application status of acoustic emission in the eastern Hubei,the AE differential ratio indicator was put forward,which took into consideration of such three AE parameters as the large acoustic emission events,and the total event period and the energy rate within a period of time.It can effectively reduce the interference on sound monitoring parameter fluctuations from the external environment,different geological conditions and different structures of the mined zone.Through comparing with the variation of the cumulative value of rock acoustic emission parameters in mined-out area,the general changing rule of the corresponding AE differential ratio indicator and its precursor characteristics of instability were obtained.The AE differential ratio indicator can not only reasonably and effectively analyze the stability of the mined-out area,but also simply and accurately predict the instable time.Then,AE differential ratio indicator was applied in Pumin iron mine in the eastern Hubei to predict the stability of mined-out area,and the prediction result was basically in accord with the actual situation,indicating that the indicator has certain applicability and rationality.