| The inclined angle of 5# coal seam is 45°, the average thick is 51.51m of the Hua-ting Coal Mine, the mining depth of 819.45m. As mining area range is small, mined-out space is large, mined-out area converge in a smaller region. Multiple-seam mining and tunneling at the same time leaded to effect of coal extraction overlapped each other, aggravated severely grade of ground pressure. Coal-mass are broken and soft, sometimes dynamic pressure manifestation are produced. This case brought very adverse influence for manufacture and security of coal mine. The study bases on cognition for in-situ mining engineering geological mechanics and ground pressure regularity, starts with ground pressure rule and dynamic disaster mechanism of fully-mechanized top-coal caving horizontal stratified in deeply-inclined extremely-thick coal seam, then achieves complex control purpose.The in-situ ground pressure monitor shows that coal extraction not only have larger effect to the roof entry of this face, but also to under roof entry. This can be lead to stress concentration. The distance between upper face and under face are shorter, the effect degree is larger. The effects of mining range ahead of upper face about 120m. The serious effect ranges the ahead of about 40m, and the rest about 80m. Floor entry is mainly affected by upper face mining, and under floor entry is affected by upper face mining, in addition the effect of coal seam main roof is larger.Complex study shows that mining coal seam and the round roof's rock-burst tendency in Hua-ting Coal Mine are weak, the ultimately reason of dynamic pressure is the exterior stress factor, that is, the stress concentration caused by mining and the main roof's collapse and movement. If you want to solve entry support problem absolutely, and to prevent the dynamic phenomenon, it needs to avoid stress high concentration, increase overlying strata self-stability time, and induce main roof energy to release.
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