Determination of the reasonable support working resistance

Support working resistance, as an important basis on choosing support, although has many determination methods, all of them have shortages due to lots of complicated influencing factors. Based on extensive reference on relative material of both home and abroad and according to the rock strata control theory, this paper compare support working resistance required in large height mining with that in slicing mining under the same geological condition by using theoretical analysis and field measurement, and successfully explains why the working resistance identified by the commonly 4-8 times High-density method in the large height mining is often lower. That is, the block can not meet the condition of voussoir beam but form cantilever beam, resulting in the roof-hanging distance is equivalent to the periodic weighting distance instead of roof-control distance. On this basis a new method called model method, which establish different mechanical models according to different geological condition, is put forward. The research results have been successful applied in Shendong mining area.