Determination of support working resistance of fully-mechanized caving in steeply dipping seam with ultra thick

In order to improve the stability of "R-S-F" system, researches have been done on support working resistance of fully-mechanized caving in steeply dipping seam with ultra thick based on physical simulation tests. The results show that the loading on supports is different in different zones along inclination, the largest support load in the middle section with average load of 5540kN, the larger support load in the upper section with average load of 5340kN and the lower support load in lower section with average load of 4966kN. The supports in middle and upper section of a steep mining face have the tendency of reverse rollover, and supports in the lower section have the tendency of dislocation slipping. In addition the support working resistance is estimated using the methods of load estimation and "R-S-F"system control theoretical. With the comparison on the above results, the support working resistance in Changshanzi coal mine is determined as 5000kN.