Study on rock burst risk assessment of fully-mechanized top coal caving mining face in steep coal seam

In order to improve the accuracy of evaluation index and applicability of evaluation method for rock burst risk of fully-mechanized top coal caving mining face in steep coal seam, the stress distribution in the working face when passing through coal pillar area and superposition effect of excavation face and mining face were carried out by numerical simulation and theoretical calculation method.The calculation system of dynamic weight evaluation method in steep coal seam was formed. This paper determined and graded the risk assessment index for rock burst in steep coal seam, and applied the dynamic weight evaluation method to rock burst risk assessment in +495 m level working face.The results show that: the main influencing factors of rock burst in fully mechanized top coal caving mining face of Jian’gou Coal Mine are coal pillar and the superposition of stress disturbance of excavation face and mining face.The risk grade of rock burst is II in +495 m level fully-mechanized top coal caving mining face. It had weak risk of rock burst, and divided into three dangerous areas: 830～1 000 m strike of working face,370～530 m strike of working face,50 m range before and after upper layer’ stopping mining line.The field test showed that the dynamic weight method can effectively realize the risk assessment of rock burst in steeply inclined coal seam.