The 4th International Symposium on Mine Safety Science and Engineering (ISMSSE2018)

333 / 2018-05-17 23:39:15

Research on response law of EMR and AE to faults ahead of driving face

Driving face,Fault,EMR and AE signals,Response law,Real-time monitoring

Gas of Coal Mine & Coal and Gas Outburst > Coal and gas outburst

The existence of faults and other structures will cause the abnormal stress in the coal seam, which will change the mechanical properties and the gas occurrence state of the coal seam, thus easy to induce dynamic disaster. Therefore, it is of vital significance for the safety production and the rapid excavation of coal mine to identify and monitor the coal structure ahead of the driving face in real time. Based these above, the mechanical analysis of the driving face crossing a fault was carried out firstly. Then coal EMR and AE signals during the driving face crossing a fault were monitored and their characteristics were analyzed. Finally, a method for identifying abnormal geological tectonic zones by EMR and AE real-time monitoring was proposed. The results showed that: 1) There was a stress concentration area in front of the driving face and the rear of the fault respectively. During driving, the superposition of the two stress concentration areas leaded to the continuous increase of stress, which created conditions for the accumulation and release of coal energy, and was the main reason for the increase of coal and gas outburst risk. 2) During the process of driving face crossing a fault, EMR and AE signals showed a distinct characteristic of piecewise change. Before, during, and after the driving face passes through the fault, the strength and frequency of EMR and AE increased first and then dropped. 3) When the driving face was close to the fault, the frequency of AE and EMR was reduced, the frequency band was more concentrated, and the change ranges of EMR and AE signals were respectively 0.3 kHz ~ 17.3 kHz and 3.66 kHz ~ 22.5 kHz; 4) The amplitude of the main frequency of the EMR and AE signals had a sensitive response to the fault, and its response range was about 10m, which could be used as the main indicator for detecting the geological structure anomaly area in future applications.