ABSTRACT
In this paper, 1193 working face in Tunbao Coal Mine was chosen as studying case. In this region, the hostrock strength is low and stress concentration exists in front of the working face. Based on the modified Hoek-Brown failure criterion (Hoek & Brown 1997), mechanical analysis on the coal and rock mass in fault influence zone was adopted for confirming the critical range. Placed optical borehole in the fault influence zone, and used the sight instrument to collection the optical information in the coal and rock mass. After statistic analysis on the borehole fractures, evaluated the joint fractures’ development characteristics and its distribution characteristics with depth, then analyzed the critical instability range of surrounding rock. Compared the theoretical analysis and field monitoring results, confirmed the critical instability range of coal and rock mass in fault influence zone in order to ensure the safe and efficient production in fault influence zone, mining technical condition.
