Mechanical analysis on instability of mining roadways under the close neighboring gob

摘要

Damage and instability of roadways are big problems to restrict excavation of the lower coal when the upper coal was mined-out in the close distance seams. There is No. 10 coal that is 2.0 m down the No.9 coal in Wuhushan mine. Based on site investigation of the spatial location of 1001 roadways and its deformation, the spatial mechanical model of lower roadway was established, then the relationship between roadway location and the re-distribution of stress after upper coal mined was analyzed and calculated, furthermore the failure criterion of lower roadways was drawn out. According to the actual conditions of No. 10 Coal Seam, the key areas prone to damage and reasonable location to layout roadway were determined. The field practice shows this method to determine roadway location could effectively reduce the roadway damage and significantly reduce the costs of advance support during its service.