Coal-rock mass dynamic fracturing characteristics and deep critical discrete range in fault zones

摘要

Mining-induced dynamic disasters caused by coal-rock mass destabilization in fault effect region are very common.Quantitative determination on the Ranging of Deeper Critical Destabilization (RDCD) of coal-rock mass is critically important for the supporting parameters optimization and mining safety.According to the safety mining idea in fault effect region of Tunbao Coal Mine, controlling parameters of coal-rock stability were confirmed by taking advantage of Hoek-Brown failure criterion theory, hence, the expression of RDCD was shown as R =k + a.In order to obtain the RDCD, a sight instrument was used to collect the optical information of hostrock around deep mining roadway, then the joint fractures' development characteristics and their distribution characteristics with depth could be predicted.So, based on the theoretical analysis and in-situ measurement, the RDCD in fault effect region was determinated, and the maximum RDCD reached 2.51 m.At last, an asymmetric supporting scheme was also proposed, which has been proved effective in roadway stability and safety.