Effect of Mining Thickness on Overburden Movement and Underground Pressure Characteristics for Extrathick Coal Seam by Sublevel Caving with High Bottom Cutting Height

Table 7

Support working resistance under different conditions of basic roof movement in different thick coal seams.

State of the roof	Support working resistance (kN)			Average of support working resistance (kN)
	9 m	15 m	25 m	9 m	15 m	25 m
Normal circumstance	4616.8∼6778.1	6065.3∼9928.0	7904.7∼12549.1	5812.4	8451.6	9885.8
Lower main roof pressure	8847.4∼9767.0	12802.0∼14917.3	13054.9∼17216.5	9251.4	13905.6	15043.7
Higher main roof pressure	12549.1∼12664.1	17078.5∼17929.2	20619.3∼23401.4	12606.6	17503. 9	22010.3