Study On Weakening Straight Overburden Sandstone Roof By Deep-hole Blasting

China has abundant coal resources,and large and small coal resources are distributed in various regions.The geological conditions of each coal section are different,but there are coal seam roof problems,especially in areas such as Shanxi,Inner Mongolia,and Xinjiang,which occupy about 70%of the country’s coal reserves.The area suspended ceiling also brings hidden safety hazards to coal mining.Once the ceiling collapses,disasters such as gas gushing and hurricanes will occur,causing damage to life and property.Therefore,roof management is particularly important.In order to solve the problem that the thick hard roof is difficult to fall,this paper takes the Wujiagou 5302 working face thick hard roof as the research object.On the premise of field survey and investigation,the method is combined with theoretical analysis,numerical simulation and field test.The mining pressure of the 5302 working face after deep hole pre-split blasting roof treatment.Through the analysis of the mine pressure data and its macroscopic performance,it is concluded that this blasting solution effectively solves the problem that the roof of the 5302 working face is difficult to fall.After the deep hole pre-splitting blasting treatment,the roof is changed from difficult to break to possible.Risk.The feasibility of the scheme for the treatment of thick and hard roofs was demonstrated.For the problems after blasting,the cause analysis and solution are given,and the scheme and blasting parameters are optimized,which provides a reference for future research.Figure[44]table[15]reference[51]...