Study on factors affecting rock burst of sub-erectcoal seam based on data analysis

In order to grasp the hazardous factors of rock burst in sub-erect coalseamin the southernpart of Wudong coal mine, based on the mining layout and occurrence characteristics of overlying coal pillars in B3+6 coal seam, the data statistics method is used to separately distribute the mine microseismic events and rock burst accidents in fully-mechanized caving face of B3+6 coal seam. The results show that the overlying coal pillar is the main disaster-causing factor of rock burst, and mining disturbance, mining depth and coal pillar resource recovery are the influencing factors of rock burst. The influence of mining disturbance is obvious when the distance of fully mechanized mining face and the development face of different coal seams during mining is 80 m and when the mining crossing distance is 110 m, and the frequency of microseisms reaches the peak when advancing difference of the two faces is with in 0～30 m.B3+6 coal seam rock burst accidents are concentrated in the pillar area of a small shaft and the industrial square areaof Dahonggou coalmine. After multi-layer mining, the stress effect of overlying coal pillar still exists, and with the increase of the numbers of coal seam mining layers, the relationship between the location of the working face and the coal pillar changed following a regular law as "before the coal pillar - under the coal pillar - after the coal pillar". When the bump pressure occurs, the fully-mechanized top coal caving face during rock burst accident concentrated in the 50 m range of coal pillar boundary, and the location and times of rock burst accident are related to the length of the coal pillar.With the increase of the striking length of the overlying pillar, the distance between the fully-mechanized caving face and the boundary of the pillar increases when the rock burst accident occurs. At the same time, the probability and failure strength of the rock burst accident in the area near the coal pillar also increase.