Discussion on the mechanism and control of coal bump among mine group

Coal bump often occurs in the mining process between two adjacent mines under the control of large geolog- ical bodies. In order to study the coal bump mechanism between adjacent working faces of two adjacent coal mines un- der the condition of large fault and huge thick overburden conglomerate,this paper investigates the 23070 working face at Yuejin coal mine and the 21220 working face at Changcun coal mine in China. The analyses of monitoring data are carried out on the characteristics of coal bump behavior,microseismic spatio-temporal evolution and microseismic ener- gy. Furthermore,the theoretical analysis and numerical simulation of stress distribution of overburden structure during the mining process of two working faces are conducted. The results show that the activation of F16 thrust fault and o- verall control of massive conglomerates in Yima mining area provide the stress conditions for coal bump. During the mining process of two mines’ adjacent working faces,the “asymmetric T-shaped” structure is formed between the rock beam above the goaf and coal-rock pillar between two mines. The coal bump around the 21220 working face leads to the stress transfer onto the two mines’ pillar and the 23070 working face,which induces the coal bump around the 23070 working face. Mining disturbance between two mines leads to stress transfer and induces rock burst,which is closely related to the initial bump intensity and mining length of later working face. Finally,based on theory and engi- neering monitoring,a coal bump controlling technique with chain-weakening and consumption-increasing between two coal mines is put forward,which regards the weakening of the structural chain of high stress transfer as core. The re- sults provide a theoretical basis for the study on the mechanism and control of coal bump between two adjacent working faces in two adjacent mines.