The method of top coal caving in roadways is a new mining technology in steep seams.

The model computer simulation for roadway sub-level caving of steep medium thickness～thick seem was set ip on the basis of industrial test It is simulated that the recovery rate of roof coal was influenced by the thickness of seam, the height of caving level and the distance of chute Thus, the optimal height of caving level was determine

On the basis of industry test,this paper analyses mining feasibility of applying roadway caving method and caving broken mechanism in high gas steeply indined medium coal seams.

Applying systematic reliability theory, the mathematical model on the reliability of the production system of roadway caving in steep medium-thickness and hish seam is set up, and the calculating formulas of the effectiveness and production ability of this system are also given.

Based on the application of artificial neural networks method, it sets up the artificial neural networks model for the evaluation on the degree of difficulty of top coal caving of roadway caving method in steep medium-thickness and high seam The model is made use of forecasting the technical-economic indexes of coal face and optimizing the technological parameters of roadway caving metho

The deformation mechanism of surrounding rock is analyzed by the energy principle,and the mechanical model of roadway roof coal is established.

This paper researched soft top coal drift stable control technology at the effect of supporting strain.