Theoretical basis and key technology of prevention and control of coal-rock dynamic disasters in deep coal mining

The occurrence condition of coal and rock strata determines the more complex occurrence mechanism of coal-rock dynamic disasters in deep mining conditions with the significantly increasing difficulty of prevention and con trol technology. How to solve the problem of prevention and control of coal-rock dynamic disasters in deep coal mining directly affects the safety of coal mines production and the efficient energy supply in China. This paper focused on the scientific proposition that “Research on the prevention and control technology of coal-rock dynamic disasters in deep coal mining”. Based on the “Three Factors” theory in rock burst and the hypothesis of comprehensive effect in coal and gas outburst,the paper has clarified some vague concepts in the items of theoretical basis,key technology and in dustry practices in prevention and control of coal-rock dynamic disasters,and established a generalized “ Three Fac tors” theory to describe the mechanism of rock burst and coal and gas outburst,which is “ Physical Factor”,“ Stress Factors” and “Structural Factors”. Consequently,four types of typical rock burst in China’ s coal mines was identi fied:coal seam material instability type,coal seam structure instability type,roof fracture type,and fault slippage type. In addition,the paper analyzes the main factors that affect the rock burst and outburst,condenses prevention and con trol technology with different sources in multi-scales for coal-rock dynamic disasters from the aspects of ideology,prin ciples,methods. This paper also proposes a “ three-level” energy-absorbing method and packaged technology for the rock burst roadway support,and develops a combined surface and underground extraction prevention and control tech nology for coal and gas outburst mines,and a combination of ultra-high pressure water jet “cross-cutting and vertical breaking” coal-rock dynamic disaster prevention and control technology,of which application tests have been carried out on the site. The establishment and improvement of theories and key technologies for the prevention and control of coal-rock dynamic disasters in the deep coal mines could provide a scientific basis for the future prevention and control of coal-rock dynamic disasters in China.