Mechanism analysis of top coal and caving roadway deformation in steep seam

On the basis of summarizing field test,the influence factors which affect top coal breaking of sub level caving in the steep seam were analyzed by elastic plastic theory. The internal relationship between ground behavior of caving roadway and top coal breaking was analyzed by the theory of rock pressure. The breaking mechanism of top coal was put forward, which could be of practical and theoretical significance in application and dissemination of the mining method.