中文摘要：

电磁辐射信号随着煤岩受载变形破裂速率的增加而增强,电磁辐射强度主要反映煤岩体的受载程度及变形破裂强度,脉冲数主要反映煤岩体变形及微破裂的频次。应用电磁辐射技术可以非接触监测煤岩体的受载及变形强度和变形及微破裂频次,从而对矿山顶板的稳定性做出评价。现场应用实践表明,采掘工序对电磁辐射监测信号有微弱影响;地质构造带等地应力异常区域电磁辐射幅值明显增加,波动幅度较大;顶板稳定性异常区域电磁辐射脉冲数明显增多,可以应用电磁辐射技术非接触监测评价矿山顶板的稳定性。

英文摘要：

The focus in the search for early warning indicators has been concentrated on observation of seismic events prior to the fall.These precursors have been studied to some extension,but none is fully successful.A new method to evaluate roof stability is put forward based on electromagnetic emission（EME） technology.It is known that wide frequent EME signals can be produced in the processes of deformation and failure of coal and rock.EME of coal and rock is a kind of phenomenon during the deformation and fracture processes of loaded coal and rock;and the EME signal becomes stronger with the increases of the velocity rates of deformation and fracture.The amplitude of EME is mainly affected by the intensity of load and the extent of deformation and fracture;and the impulse number is mainly influenced by the rate of deformation and microfracture.The EME technology has been applied to monitor the hazard degree of coal and gas outburst and rockburst in mines.By means of EME technology the tunnel stress distribution and stress state in working faces can be also evaluated.So,by means of EME monitoring technology,the stability of mine roof can be evaluated.The excavated work procedure has slender effect on the EME monitoring data.The EME amplitude and fluctuation become distinctively greater in geological structure where the strata stress is high.The EME pulse increases distinctively in the roof instability zones.It has been primarily estimated by the practice in certain mine that the EME monitoring technology can be applied to monitor and evaluate the stability of mine roof.