Study on safe mining height of top coal caving for shallow buried coal seam under rivers in Gaotouyao coal mine

The height of water conducted fissure is the main basis for coal mining under water.In this paper,using the methods of the procedures forecast,numerical simulation,equivalent material simulation and engineering analogy,the height of water conducted fissue was analyzed for shallow buried coal seam under the rivers Shuiduohuchuan and Dahatatugou in Gaotouyao Coal Mine.The results showed that there was an error for these forcasting results,and combined with engineering analogy,the ratio of the height of the fractured zone to the mining height is 15 under the rivers Shuiduohuchuan and Dahatatugou.Because the overlying strata on 2-3 coal seam is thin in Gaotouyao Coal Mine,according to coal mining regulations,the mining height must be controled,h≤H/19,in order to reach the purpose of controling the height of water conducted fissure and achieve the safety mining under the rivers.