Study on mechanical model and hydraulic support working state in mining stope with large mining height

The theories of strata movement and stress distribution law and transferring beam were applied to build the structural mechanics model with large mining height, the overlying strata structure characteristics and its movement laws with large mining height was discussed, the concept of immediate roof and basic roof with large mining height was revised, the calculation method of support load and shrinkage quantity with Given deformation and Limited deformation state was confirmed. The results show that the immediate roof thickness and possibility of appearance of long span hanging roof may be increased greatly, the transferring beam scale(including its number and total thickness) was decreased relatively, the distance between coal seam and related rock beams was increased. The hanging roof location, thickness and possible greatest span should be confirmed accurately, they are the keys of roof control design and support selection calculation with large mining height mining stope.