Taking coal roadway of high deviatoric stress in a coal mine in Shanxi as the background,the distribu-tion characteristics,evolution law and fracturing mechanism of tensile-shear fracturing were investigated combing the theoretical analysis,numerical and physical simulation. An innovative and optimized full-length zoning support-ing method along the excavation direction was proposed for surrougnd rock of roadway. The results show with lateral pressure coefficient is 0.60,wedge failure occurs in two sidewalls of roadway,the roof and floor are obviously un-loaded,and the stress concentration occurs at the four roadway corners. As lateral pressure coefficient gradually de-creases to 0. 24,the "butterfly wing" gradually developed with the failure iniating from two sidewalls under the effect of shear fracture,eventually forming a butterfly-shaped fracture pattern. The tensile-shear mixed fracture zone existed in the shallow part of the excavation damage zone,but dominated by tensile fractures. However,the shear fracture is dominant in the deep part. The fracturing evolution process of surrounding rock can be divided into three stages:self-destruction stage of the circular free surface,gestation and expansion stage of the"butterfly wing",and expansion and stable stage of the "butterfly wing". The stress threshold according to the full-length partition of roadway was defined and the full-length zonal control method of the roadway was put forward. This research provides theoretical basis for the differential supporting of roadway during coal mining.
关键词
高偏应力/拉剪破裂/托顶煤巷道/分区支护
Key words
high deviatoric stress/tensile-shear fracture/top coal roadway/zoning support
维普
万方数据