Permeability changing laws of surrounding rock under the influence of coal mining and prediction of water yield of working face in Ningtiaota Coal Mine
The permeability change of surrounding rock in coal mining processing plays a crucial role in the accuracy of the prediction of water yield of working face.In this paper,taking the sandstone for roofing of Ningtiaota Coal Mine as the research object,the horizontal and vertical permeability coefficient change laws of the surrounding rock are simulated and analyzed by fluid-solid coupling module in FLAC3D software,and based on which,the water yield of working face of S12003 is predicted and analyzed by using GMS.The results show that when the advancing distance of the working face is 100 m,200 m,300 m and 400 m,the maximum horizontal permeability coefficient increased by 10 times,500 times,10 000 times and 1 000 000 times,respectively,and the maximum vertical permeability coefficient increased by 5 times,50 times,100 times and 10 000 times respectively.Different parts of the horizontal and vertical permeability coefficient change laws are not consistent.With the increase of advancing distance,the range of pore water pressure down to 0 MPa and the range of plastic damage occurs in the upper part of the overburden rock both show a gradual increasing trend.Based on this,the predicted water yield of working face show that it increases gradually and then decreases with the advances of the working face,and finally the water yield of working face is basically stabilizes at about 210 m3/h.At this time,the static storage capacity of the overlying Zhiluo group pressurized aquifer have basically been drained,and the water yield of working face is mainly the lateral recharge of the aquifer.The predicted results are consistent with the actual situation.The research results will provide reference for the prediction of water yield of working face under similar conditions.
NETL
NSTL
万方数据
