Research and application of mining design based on prevention of rock burst under giant thickness hard strata

In China,many mining areas with extremely thick and hard rock strata has strong mine earthquake and strong rock burst caused by the movement of extremely thick and hard rock strata which have serious consequences,is difficult to be controlled and has become the main obstacle to mine safe production. Based on the analysis of the occur- rence law of rock burst under extremely thick and hard rock strata,the paper puts forward three common characteristics of rock burst in such mines:“the effect of key working face”,“ the effect of vibration-induced rock burst” and “ the effect of rock burst and vibration. ” “ Key working face” means that the mining of this working face will lead to the fracture and strong movement of extremely thick and hard rock strata and the occurrence of strong earthquake or rock burst. “The effect of key working face” refers to the strong dynamic disasters occurring in the mining process of “key working face”. “The effect of vibration-induced rock burst” refers to the rock-burst hazards caused by the dynamic stress which generated by the fracture and vibration of extremely thick and hard rock strata propagating to the coal body in the high stress state. Its feature is that “the location of the source is different from that of rock burst. ” “The effect of rock burst and vibration” means that when the key working face is mined,the transmission pressure of ex- tremely thick and hard rock strata will increase sharply. When part of the coal reaches the condition of rock burst,the rock burst will occur and cause vibrations with great energy. The characteristic of this kind of rock burst is that “ the location of the source is the same as that of rock burst. ” Using the theory of overlying strata spatial structure,surface subsidence observation and monitoring data of microseism and stress,a method for identifying the key working face is proposed. This paper describes the concrete methods of preventing rock burst and ensuring safety in three different types of mines with extremely thick and hard strata and the possibility of rock-burst disasters in Shandong Energy Group. These methods include protection layer mining,negative coal pillar design,determination and parameter design of key working face,mining design to avoid the boundary of vibration damage,small coal pillar design and parameter optimization design of sequential mining face.