As for the coal mining roadway with bolt support, it’s the most dangerous that the roof usually falls because roof bedding separation value is too large. In order to calculate the critical value of roof bedding separation, the mechanism of roof bedding separation was analyzed, moreover, the mechanical models of solid-coal roadway and gob-side roadway were built. Based on analyzing the mechanical property of the two different roadways supported with bolts, the mathematical representations of roof bedding separation critical value were got. Finally, a calculation example was showed, and the results indicated that the roof separation critical value of gob-side roadway is more than that of solid-coal roadway. Furthermore, the representation of gob side roadway coincided with the monitoring value, and the representation of solid-coal roadway can be used to predict the critical value in the period of driving.
