In order to explore the damage and failure mechanism of the coal-rock interface of outburst coal seam and clarify the precursor information of dynamic disasters such as hole spray and coal bursts,the research methods of micro-seismic monitoring and theoretical analysis were adopted to analyze the spatiotemporal evolution characteristics of micro-seismic events during the drilling process from rock layer to coal seam,and the precursor information characteristics of micro-seismic event frequency,apparent stress and failure form before the hole spray phenomenon.The results showed that according to the frequency and energy of micro-seismic events,the damage of rock mass at the coal-rock interface could be divided into three stages from the time dimension:weak-disturbance stable period,strong-disturbance active period and no-disturbance decline period;according to the spatial distribution,the damage of rock mass could be divided into affected area,damaged area and broken area;the frequency of micro-seismic events reached 2 to 3 in a short time,the apparent stress was greater than 30 kPa,and the tensile failure ratio increased significantly.
关键词
微震监测/煤岩交界面/喷孔/微震事件/煤与瓦斯突出
Key words
micro-seismic monitoring/coal-rock interface/spray hole/micro-seismic events/coal and gas outburst
维普
万方数据