Abstract:

The surrounding rock controlling technology of the gob-side entry driving with high stress in the island coal face is one of the necessitated problems in coal mines. Take the return airway No.80509 of the No.2 Yangquan colliery as an example, combined with field observation, experimental test, theoretical analysis and field test, etc., the deformation and broken process of the roadway, the X-ray diffraction and electron microscope scanning to the immediate roof, floor of the roadway and the mining coal seam, physical and mechanical properties test to the coal and rock samples of the immediate roof and floor are studied, respectively, and then a combined support technology including high performance bolt, pre-stress cable and pre-stress cable truss is put forward. We obtained: (1) The deformation and broken process of the gob-side entry driving with high stress in the island coal face is: lower part “leaving the former place” of the coal side, the upper part “loose coal side”, “move the coal side” and “collapse of the roadway”. (2) The deformation origin are large disparity of the physical and mechanical properties of the immediate roof and floor, high lateral stress and mining stress and the improper support technology. (3) The new type of supporting technology could effectively control the deformation of the surrounding rock of the roadway and safeguard the roadway safety during the excavation and mining activities. The obtained research has some preferable value to supporting design to similar coal roadways.