Abstract: To analyze the top-coal caving process and movement characters in steeply dipping thick coal seam face, similar simulations were conducted and fifteen models were constructed according to different top-coal caving interval, top-coal caving sequence, caving methods and dipping, and the influence on recovery ratio and movement law of top-coal and gangue under different caving conditions was comparatively analyzed. The results show that：The combination mode of single sequence top-coal caving from lower to upper in dip direction and one-mining one-caving in the mining direction has the highest recovery ratio, and the recovery ration decreases with coal seam dip increasing. The caving is an non symmetrical cone due to the influence of coal seam dip, a turbination funnel type is presented when caving from upper to lower, whereas a positive conical funnel type is presented when caving from lower to upper. The coal seam dip angle has little effect on the caving funnel. The top-coal retention phenomenon of caving appears from upper to lower, but not appears from lower to upper, thus the lower-end should be caving as much as possible whereas the caving should be controlled on upper-end.

Key words: steeply dipping, top-coal caving face, coal caving process, movement of coal and gangue