Abstract:Based on the data of geotechnical survey,the cavability of ore/rock in some mining area was analyzed and evaluated with RQD method,RMR method,Q-system and MRMR method,and the levels of cavability of ore/rock masses were determined.The size distribution of caved fragments was analyzed and predicted with BCF,a program to predict block cave fragmentation,it provided a basis for the design of bottom structure of block caving.