Evaluation Of Water Inrush Risk Of Pingdingshan No.13 Coal Mine Based On EW-FAHP

The water damage of Pingdingshan No.13 mine is Serious,There was many times water inrush at beginning period of mine production.There were 12 times water inrush accidents in the mine over the years,large and medium-sized water inrush in the mine are often accompanied by the indirect recharge of deep Cambrian limestone water.Ji₄ mining area is the most complex geological and hydrologic unit,with tectonic development.limestone karst water of Taiyuan Formation and Cambrian,with rich water strong water yield property,abundant recharge source and high water pressure could enter entered into mines through fault,karst fissure and mining fracture.The risk of water inrush is enhanced with the increasing depth of coal mining and water pressure in coal seam floor increasing.Therefore,it is necessary to analyze the deep hydrogeological conditions and find out the law of karst development.On this basis,objective and effective evaluation of the water inrush risk of Cambrian limestone under coal seam in Ji₄ mining area is a urgent problem to be solved.By comparing the methods of mechanism of water inrush from coal seam floor and forecasting methods,according to water inrush problem of Cambrian limestone water under coal seam in Ji₄ mining area of the Pingdingshan No.13 mine,This paper use used the vulnerability index method to evaluate coal seam floor water inrush risk in Ji₄mining area.Based on the analysis of the geological environment background in the study area,hydrogeological conditions and water inrush data,the four main controlling factors for the assessment of the risk of water inrush from coal seam floor were determined as follows:cold water pressure,rich water,effective water barrier aquiclude and fault.By using the ArcGIS attribute assignment function and the spatial interpolation function,the main influencing factors of the original data were quantified,and the attribute database of main influencing factors were established and the thematic map was created.Due to the multiple water inrush of the thirteen mine is related to the fault,the fractal dimension theory is used to quantify the fault,and the distribution map of the fault structure is formed.By using the entropy weight fuzzy analytic hierarchy process,the weight of the influence of the Cambrian limestone water pressure,the water abundance,the fault and the effective aquiclude on the total target is calculated as follows:0.303,0.122,0.397,0.178.Using GIS powerful spatial analysis ability,the main controlling factors of the normalized thematic map according to the weight value weighted superposition,coal seam floor water inrush risk evaluation model of Ji₄mining area was established.Using GIS powerful spatial analysis ability,the main controlling factors of the normalized thematic map according to the weight value weighted superposition,coal seam floor water inrush risk evaluation model of Ji₄mining area was established.Through the natural discontinuity method to determine the partition threshold,the coal seam floor water inrush risk of Ji₄ mining area was divided into vulnerable area,relative vulnerable zone,transition zone,the safe area and more safe area of a total of five regions.The water inrush vulnerability evaluation zoning map of coal seam floor in No.13 coal mine Ji₄ mining area was drawed.The evaluation results show that II₁ coal seam floor of Ji₄ mining area in Pingdingshan No.13 coal mine elevation-150^-420.5m area,isn’t affected by the floor limestone water,belonging to the security zone;the area belongs to a relatively safe area which is not affected by the fault of the region in the elevation of–420.5^-600m;the area belongs to a transition region which isn’t affected by the fault of the region in the elevation of–600^-820m;the area belongs to a water inrush danger area which is affected by the fault of the region in the elevation of–600^-820m;the area belongs to water inrush danger zone which is in the elevation of-820m and below or faults zone in the elevation of-600^-820 m.