Research on the Influence Mechanism of Tectonic Stress in the «Three Hard» Coal Seam in Coalfield on Rockbursts.

This paper addressed the rockburst hazards caused by tectonic stress in the "three hard" coal mine in Datong Coalfield. We analyzed tectonic stress characteristics in the mining area and the mechanism of tectonic stress inducing rockbursts. We built the stress analysis model for rockburst-inducing tectonic stress. The roadway of the coal seam 12# in Xinzhouyao Coal Mine of Datong Coalfield was explicitly analyzed as an example. It was found that roof bedding separation was very likely to happen under the action of local tectonic stress in the roadway of the "three hard" coal seam, causing rockbursts that pushed out the coal wall. Numerical simulation was performed to analyze the occurrence of rockbursts induced by tectonic stress. We validated that stress concentration was more likely to happen in the coal-rock masses under the action of the tectonic stress, causing rockbursts. Besides, a large horizontal stress gradient would be formed near the roadway coal wall when the principal stress was perpendicular to the roadway axis. Rockbursts were highly probable in the coal-rock masses under this situation. [ABSTRACT FROM AUTHOR]