Research on the Characteristics of Technical Parameters for Microseismic Signal Propagation in Excavation Working Faces
Malan Mine of Xishan Coal Electricity is a coal and gas outburst mine.Aiming at the high stress distribution characteristics in coal and gas outburst danger areas and the limitations of outburst prediction and early warning ways mainly based on gas parameters,research is conducted on the propagation range and waveform parameter distribution characteristics of microseismic signals.Microseismic monitoring is used to achieve real-time monitoring of stress distribution and coal body damage status in front of the mining and excavation working face.The on-site monitoring data indicates that the effective propagation range of microseismic signals during the coal roadway excavation process can reach 67 m.In order to achieve effective monitoring of microseismic signals and reduce the daily maintenance of the early warning system,it is necessary to ensure that the position of the sensor is moved at least twice a week,and the time interval should be kept within 3 days as much as possible;the time domain parameters such as waveform amplitude,rise time,duration and others of microseismic signals are mainly concentrated in the low value region,and their frequency speed curves show a chi square distribution characteristic of first sharply increasing,then rapidly decreasing,and tending to zero;while the peak frequency is mainly distributed on a limited number of discrete frequency points.The distribution characteristics of time-frequency domain parameters provide technical support and judgment basis for the selection and noise filtering of microseismic sensors.