Sloughing mechanism and control of coal wall in high cutting fully-mechanized top coal caving mining face in ultra thick seam

According to the serious sloughing problem of the coal wall nNo.F622 high cutt g full - mechanized top cal caving mining face inBuliangou Mine, with th site investigation and obsevation.based on the spallig locaton of the cal al. he paper had a summarization and analysis on the spalling bas c features of thecoal wall in the mining process The paper had a further analysis on the roof structure,powered support workng res itance and coal mining face pushing forward speedaffected to the salig degreeof the cal wall The stuty showed that a coal wall impact by the rebcunding zone at the upperof the coal val .cured by the insabilitand breaking of the combined suspended beam in the botom combined suspended beam upper lined beam structure formed by the roof.as well as thestrength pseudoincreased of the combined suspended beam structure strength and the instantaneous releasing of the accurulated more strain energy caused by the low resistance ofthe powered support and oofast pushing forward speed of the coal mining face would be the inporant factors to cause the sloughing f the coalwal nder the conditonof the igh cuting full - mechanized top coal caving mining. The working resistance of the powered suppor increased would reduce the sloughing degree ofthe coawell A comprehensive sloughing control plan of the " seam water injction proper reduced pushing foward speed of the cal mining fae and the working resistance ofthe powered suppor increased" as provided. The engineering practices showed tht anter conrol plan conduced,the sloughing frequency of the cal wall and dail soughing depth were both highly reduced than previous and good sloughing control effect was obtained.