Research On The Prediction Of Development Height Of Water Flowing Fractured Zone In Overlying Strata

The exploitation of working face has been threatened by the water of old kiln around the coal mine,the above mined-out space and the aquifer group of sandstone and limestone,which has become increasingly serious problem.The overlying strata in roof of coal seam could be fractured and moved in the process of mining,concurrently the water flowing fractured zone would be formed.When the developed height of this zone extends to the boundary of flushing water,the zone would be likely to become water flowing channels and bring about seriously impact for the safety of underground mining.The paper is mainly based on the background of distribution law of XiShan coal mine about“upper three zone”in main coal seam and“lower three zone”of coal mining under pressure.It made study of the MaLan,GuanDi,DongQu coal mine,and previously collected the geological condition of production,the occurrence condition of the coal seam,physical-mechanical property and the mining technology parameter,etc.Based on extensively reading and classification-summary to analyze the mainly influential factors of developed height and summarize formation mechanism of water flowing fractured zone.It is observed by the upward or downward slant deep drilling to carry out the measurement work as well as counted the measured height data of water flowing fractured zone?permo-carboniferous coal seam?.Take the working face of 22611 in GuanDi coal mine as an example,the development height of water flowing fractured zone is 47.6m by using pressurized-water test method in the upward slant hole on the underground The working face is numerical simulated by FLAC^3D software,the height of roof in overlying strata is 54.5m.When the length of the working face moves to different distances,get the shape of the plastic damage zone of"arch"and"saddle shaped".The stress concentration is larger.in the stress concentration area behind the working faceCounting 35 data of measuring the development height of water flowing fractured zone in working face?Eliminate 5 abbnormal data?.After statistical analysis,we get the regression equation about the fitting curve of mining depth,the fitting curve of mining thickness,the uniaxial compressive strength of rock and the length of working face of the height of water flowing fractured zone,the fitting formula is composed up of single factor and the height of water flowing fractured zone.After model test and optimize,getting the new regression equation and the fitting formula of the thickness and the height of water flowing fractured zone that It is of practical significance to estimate the height of water flowing fractured zone on the roof in permo-carboniferous coal seam and the height of water flowing fractured zone of the coal seam roof under the fully mechanized mining condition in the XiShan mining area.It is important to improve the recovery rate of coal resources and the safety of the mine production.