掘进工作面微震信号传播技术参量特征研究

Research on the Characteristics of Technical Parameters for Microseismic Signal Propagation in Excavation Working Faces

西山煤电马兰矿为煤与瓦斯突出矿井,针对煤与瓦斯突出危险区域的高应力分布特征以及以瓦斯参数为主的突出预测预警手段的局限性,开展微震信号传播范围及波形参数分布特征研究,采用微震监测实现采掘工作面前方应力分布和煤体损伤状态的实时监测。现场监测数据表明:煤巷掘进过程中微震信号的有效传播范围可以达到67m,为实现微震信号的有效监测,并减少预警系统的日常维护,必须确保每周至少移动2次传感器的位置,且时间间隔尽量保证在3 d以内;微震信号的波形振幅、上升时间和持续时间等时域参量主要集中在低值区间,其频次曲线呈现出先急剧增大后迅速减小并趋于零的卡方分布特征,而峰值频率主要分布在数量有限的离散频点上,时频域参量分布特征为微震传感器的选型和噪声滤除提供了技术支撑和判断依据。

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.