Study On Rockburst Tendency Of Coal Or Rock And Forcast For Rockburst In Pingdingshan Mining Area

With the increasing depth of mining, rock burst is becoming more and more serious. It has become a major disaster for the production and safety of mining. The influences, prediction and prevention of rock burst were studied in this thesis, based on the real geological, coal seam and mining technology conditions in Pingdingshan coal area.The rock burst tendency of coal and its roof and floor in Pingdingshan were studied, using the elastic energy index, burst energy index, dynamic failure duration and bending energy index. The tests concluded that most coal seams and their roofs and floors have moderate or weak rock burst tendency. The acoustic emission under uniaxial compression damage and loading and unloading for coal seams was studied, as well as the uniaxial compression damage and flexural failure for its roof and floor. It concluded that most samples had a"quiet period"before damage. This conclusion provided a basis for the forecasting of rock burst.The factors of rock burst at the location of bump were studied. Through numerical simulation software of FLAC2D, the effects of coal bed hardness and the distance from hard and thick roof to coal seam on rock burst were studied. The distance from hard and thick roof to coal seam is closer, the rock burst is more likely to appear. The harder of coal seam, the higher of the stress in coal seam.The shock hazard of J15-16-24110 was predicted with composite index method, and moderate rock burst tendency appears in this working face. Meanwhile, the cuttings tests were conducted in the headway and gateway of the working face, and abutment pressure effect to shock hazard were predicted. It concluded that shock hazard appears in gateway under abutment pressure, it appears in headway within 30m to the working face, and becomes weaker beyond 30m to the working face.