Analysis of surrounding rock stability based on mining stress field and microseismicity

Combining with an engineering case of Shirengou iron mine,mainly studied the relation between mining stress field with microseismicity and surrounding rock stability.The law of microfracture production aggregation and evolution was detailed analysised nearby No.15 exploration line during the process of gob formation and open pit internal emission.A mechanical model was established by FEM ANSYS to simulate the mining stress field distribution under different mining conditions.Then the comparison of the stress field distribution and microseism distribution show that the rock microseismicity is induced by the change of stress status and microseism events usually aggregate in the stress concentration regions.By examing the practical field rock mass status,we find the destructiveness of the region where the high energy microseism events aggregate more serious than the surrounding area.The results show that the density and energy of microseism events can reflect destructiveness of rock mass really.It’s reasonable to take them as the rock mass stability evaluation index.At last,based on the understanding of above relationship,combing with the next stage mining stress field,the poor stability rock mass is identified and the the corresponding control measures are pointed out.