A research into underground pressure in longwall face induced by use of sublevel caving in thick seam

This report is written basically in accordance with the test results of two fully mechanized longwall sublevel caving faces. This paper mainly deals with the movement laws of roof coal and upper strata, and support loadings and types when coal face is under operation with a thickness of coal seam about 6 meters. It is believed that support loading in sublevel caving working faces do not surpass that in slicing coal faces which have similar roof and coal seam conditions. It is also proved that the caving supports with long canopy are best suitable for use in hard thick coal seams. If deep holes are driUed in the panel in parallel with faceline and are injected with high pressure water, the strength of coal body will be reduced, and the caved roof coal recovery wi∏ be increased.