During the drivage of main-gate in long-wall face with fully mechanized caving mining, the gate is hard to support due to its loose and broken roof, large cross-section and long span.

• 在综采放顶煤工作面顺槽掘进过程中,由于顺槽煤层顶板松动破碎,并且顺槽采用矩形断面,顶板跨距较大,不利于巷道支护。