Study on the water inrush evaluation and major contributing factors determination using vulnerable index method in a built-up coal mine

The hydrological data is always incomplete and inaccurate in built-up coal mines,which leads to many difficulties in water inrush forecasts.The AHP vulnerable index method was applied to analyze the water inrush risk because of its advantage in quantifying the influence of related factors.Six factors were selected as the major contributing factors in the evaluation model.The corresponding single factor thematic map was established through GIS and the weight of each factor was acquired through the established AHP model.By superposing the six factors,the entire floor was divided into four zones,which were vulnerable area,slight vulnerable area,slight safe area and safe area respectively.The past water inrush accident verified the forecast result.The sensitivity of the six factors was analyzed and the water-resisting layer played a significant role in controlling water inrush from floor.Several suggestions based on the prediction results were put forward: the west area should be mined firstly and the east area should be put focus prevention.The methodology has guiding significance on forecasting and controlling water inrush in built-up coal mines.