A Mine Evaluation Of Water Inrush From Floor In Zhuozishan Coalfield,Inner Mongolia

With the increase of coal mining depth,the water pressure is also growing in the mining process,mining under high pressure has becomed the main way of deep coal resource development,the damage of the floor water will become the main safety problem in the mine construction and production process,so,it is very important to carry out the risk evaluation to coal mine safety.In this paper,a coal mine is used as an example to evaluate the water inrush risk of Ordovician limestone aquifer in the lower section of in the sixteen coal seam by using the AHP type vulnerability index method based on fractal theory and five graph double coefficient method,And the results of the methods were compared and analyzed,the corresponding countermeasures and suggestions are put forward according to the evaluation Results.Thesis research has achieved the following understanding and results:Firstly,the risk of water inrush in the sixteen coal seam is evaluated by the AHP vulnerability index method.The result show that the vulnerable area and the more vulnerable area are located in the south and middle of the study area and the possibility of water inrush is large in this area;the safety zone is located in the eastern part of the study area and is unlikely to cause water inrush;other areas are transitional areas and safer areas that there is less possibility of water inrush under normal circumstances,but there is a possibility of water inrush in the tectonicst area.Secondly,the risk of water inrush in the sixteen coal seam is evaluated by the double coefficient method of five graphs.The result show that the eastern region is the non-pressurized,which is a safe;Zone I is a straight-through water inrush danger zone,located in the central and western part of the study area,and is likely to have a straight-through water inrush accident;Zone II is a non-straight-flow water inrush danger zone,which is distributed in the middle of the study area in strips,and there may be water inrush accidents,especially in tectonic development areas;Zone III is a non-straight-through relative safe zone,in the transition zone between non-straight-flow water inrush danger zone and non-pressure zone,where the possibility of non-straight-through water inrush is small,but there is a possibility of water inrush in the tectonic development area.The double coefficient method of five graphs is mainly based on the water inrush coefficient and the belt pressure coefficient,and the tectonics conditions are less considered,so the prediction effect of the tectonic development area on the water inrush from the floor is not ideal.As a new type of water inrush risk assessment method,the vulnerability index method comprehensively analyzes and considers the interaction between various factors,which can better predict the risk of water inrush from coal floor,but it does not consider the pressure coefficient,so it cannot determine the straight-through water inrush.Both methods have their own advantages and disadvantages,so the two evaluation methods be considered together to obtain a more reasonable evaluation result.