Analysis and Application on Inverted Arch Support of Cross-cut Floor Heave

Abstract

The cross-cut is an important gateway to connect the main roadway and the coal seam. The transportation, the pedestrian and the ventilation of mine could be seriously influenced by floor heave of cross-cut. Aiming at the severe floor heave of +1100 m track cross-cut in Liu Yuan Zi Coal Mine, the cross-cut surrounded with hard roof and soft floor was found. To solve this problem, the bolt-net-shotcrete and 36U-shape steel combined supporting (the original supporting scheme) and the bolt-net-shotcrete and 36U-shape steel round shed combined supporting (the new supporting scheme) respectively were applied to the cross-cut by numerical analysis. The simulation results indicate that the floor heaves is reduced by 57%, and the surrounding rock stress was changed from tension to compression at the bottom and the plastic range decreased and trended to homogenization. Field application results indicat that the cross-cut floor heave can be controlled effectively by bolt-net-shotcrete and 36U-shape steel round shed combined supporting. The conclusions provide a reliable technical scheme for hard roof and soft floor roadway.