Study On Risk Evaluation Method Of Floor Water Inrush At Condition Of Multiple-aquifer

Water hazard is one of the five big disasters in coal mine,it always threatens the safety of coal mine production,is the problem that to be solved in our country.In recent years,coal mining scale continues to expand in our country,with the increase of mining depth,the pressure on floor will increase when the coal seam is mined,water inrush is becoming more and more serious.Water hazard has become one of the major problems affecting the safety of coal production,and it is necessary to predict the risk of floor water inrushThis paper,taking Anli coal mine as an example,give a risk evaluation of No.?₂floor water inrush,by using fractal theory and Analytic Hierarchy Process?AHP?-Entropy Weight?EW?composite weight based vulnerability index method.First of all,combined with the natural geographical,geological and hydrogeological conditions of Anli coal mine,contrast with Wuguiqiao coal mine by using fractal theoryand statistical analysis,the results show that the two mines are more similar in geological structure,floor aquifuge and aquifer.Then,construction of floor water inrush risk evaluation system for No.?₂ based on richness of aquifer,water pressure aquifer,equivalent thickness of the effective and fractal dimension,on the basis of considering the subjectivity and objectivity of weight calculation,using AHP-EW to determine the weight of factors.Differential analysis for factors by using ArcGIS,establishing attribute database of major factor and its thematic map.In the end,verified the correctness of the method that combine AHP-EW method with vulnerability index method by water inrush point in Wuguiqiao coal mine,then,apply this method to evaluate of floor water inrush in Anli coal mine and compare with water inrush coefficient method.The studies shows that it is the larger risk of floor water inrush for No.?₂ coal seam in Taiyuan limestone of sixth,vulnerable area and smaller vulnerable area account for 68.48%of the mining field,then risk of water inrush has a degressive trend from the north to the south.Floor water inrush vulnerable area of ordovician limestone for No.?₂ coal seam mainly concentrate on the central mining field,vulnerable area and smaller vulnerable area account for 26.02%of the mining field.Compare with water inrush coefficient method,we can knows that this method,more comprehensive consideration and evaluation of the gradual transition from security to vulnerable areas,is more scientific,reasonable and practical,which is more conducive to the prevention and control measures for different regions...