Study on temporal and spatial evolution law of microseism in upper layer mining face rib spalling
The occurrence of coal wall rib spalling might affect the safe mining of working face.Based on the microseismic monitoring data of rib spalling in No.16111 Face of Zhaogu No.1 Mine,the temporal and spatial evolution law of microseismic events in the process of rib spalling was studied.The following conclusions were drawn:when the upper layer of thick coal seam was mined,the frequency of roof microseismic events was high.In addition to the influence of mining,the frequency development was significantly affected by fault structure,rib spalling,mining speed and other factors.When the rib spalling occurred,the frequency of roof events increased greatly,which affected the periodic change of the working face.and had a great influence on the roof.The energy release was violent,which was easy to cause the roof fall accident.During the period of rib spalling,the influence range of advance increased,and the maximum value reached 152 m,which increased sharply compared with other periods.It could appropriately accelerate the advancing speed of the working face,reduce the action time between the advanced concentrated stress and the coal wall,weaken the damage effect of the overlying strata on the coal wall,and reduce the probability of spalling.
spalling ribmicroseismroof eventadvanced influence zonelag influence zone
国家科技期刊平台
NSTL
万方数据
