Study On Surrounding Rock Stability Of Bed Plate Tunnel Under Mining Pressure In Pan Yidong Mine

Gob-side entry retaining technology can realize safe and efficient mining in deepgassy mine, which is an important change of coal mining technology. As the air-returngate of Y type ventilation system, bed plate tunnel has to be influenced by theintense dynamic pressure, so surrounding rock stress redistributes and secondly occursdeformation and breakage, which is a great threat to gob-side entry retaining. So studyon stress evolution law and reinforcement technique of bed plate tunnel influenced bymining are of important significance to implement gob-side entry retainingsuccessfully.This paper took the bed plate tunnel reinforced in gob-side entry retaining projectof PanYidong mine1231(1) working face as the background, studied the surroundingrock stability of bed plate tunnel influenced by mining through the way of numericalsimulation, mechanical model, theory analysis, engineering conditions and so on, gotthe distribution law of stress around stope, transfer paths and affecting depth of lateralstress, and stress field characteristics and deformation and failure law of bed platetunnel. Moreover space influence factors to roadway stability was analyzed, and it gotminimum vertical and horizontal distance for keeping bed plate tunnel stable duringthe mining period.According to the force and deformation characteristics of bed plate tunnel,extrusion displacement models of roadway surrounding rock were established,deformation law of roadway was tentatively analyzed, and the conditions, mechanicalcauses and influencing factors of the roof-floor and ribs lithology movement were got.According to bolting and grouting integrated principle, combined with newmultiple position extensometer and borehole imaging, an effective support way tocontrol surrounding rock deformation was put forward. And it worked successfully.The above results were applied in1231(1) working face bed plate tunnel to trackcrossheading of Pan Yidong coalmine, Huainan mining group. The results showed thatthe reinforcement scheme was reasonable, roadway surrounding rock deformationwas efficiently controlled during mining period.