Study on microseism response law of roof strata disturbance in extremely thick coal seam mining
Chang Chenglin1, Du Yuanhao1, Gao Hongwei1, Xue Wuqiang1, Wang Yin1, Chen Jiandong2, 3
1. Ordos City Huaxing Energy Co., Ltd., Ordos 017000, China; 2. Hebei Coal Research Institute Co., Ltd., Xingtai 054000, China; 3. Hebei Key Laboratory of Mine Microseismicity, Xingtai 054000, China
In view of the phenomenon of large mining height, wide mining width, long strike and high in-situ stress of overlying strata in fully mechanized top coal caving in extremely thick coal seam of North China coalfield in western Inner Mongolia, taking Tangjiahui Coal Mine of Huainan Mining Group as an example, by comparing and analyzing the development of roof microseism events in roof cutting and non-roof cutting mining faces, the response law of microseism monitoring in the mining process of Carboniferous coal seam in thick main mining was studied, and the time-space-energy comprehensive response characteristics of microseism monitoring were analyzed. The results showed that for the uncut roof working face of No.6 coal seam in Tangjiahui Coal Mine, the disturbance range of roof strata monitored by microseism monitoring was large, which could reach 15 ~ 20 times of mining height. In the working face with roof cutting and pressure relief measures, the height of overburden failure monitored by microseismic monitoring was about 12 times of the mining height, which had obvious effect on the control of roof strata pressure in extremely thick coal seam mining. Roof cutting and pressure relief could build a relatively low stress area in advance to avoid dynamic disasters caused by abnormal mine pressure.