Research on contributing factors of steeply inclined coal seam rock burst based on microseismic spatio-temporal information

Abstract

In order to understand the factors leading to rock burst in steeply-inclined coal seams, based on the mining layout and on-site microseismic monitoring data, the distribution of mine microseismic events and previous rock burst events are deeply analyzed from time and space, and the evolution law of disaster factors under different mining depths is studied. The study shows that the rock burst in steeply-inclined coal seams is mainly caused by stress concentration on the working face due to the hanging roof and intermediate rock pillars, as well as the dynamic disturbance induced by the fracture of the coal and rock mass. The daily advance rate, mining depth, and remaining coal pillars are strongly correlated with the occurrence of rock burst events, and are the main factors leading to rock burst in the mine. During shallow mining, the “prying force” effect of the intermediate rock pillars caused by the horizontal tectonic stress and the self-weight stress on the coal-rock mass is the main factor causing instability and failure of the coal-rock mass. After entering deep mining, the “extrusion” effect of the hanging roof is superimposed on the “prying force” effect of the intermediate rock pillars, and the factors leading to rock burst change to the combined “extrusion + prying force” effect of the roof and pillars.

Keywords

• rock burst
• microseismic monitoring
• contributing factor
• spatial-temporal information
• steeply inclined coal seam
• coal-rock instability