Failure Rule Of Floor Mining And Risk Assessment Of Water Inrush In No.10 Deep Coalbed At Suntuan Mine

Suntuan mine is located in the North China coalfield.Through the analysis of the engineering conditions and hydrogeologic conditions of mining area,the geological structure is complicated.The water of Taiyuan Formation limestone is weak to moderate,the water pressure is high and the watery is inhomogenious,which will cause water inrush danger when mining No.10 coalbed.At the same time the development of structure and fracture is complex,these cracks will destory the integrity of aquiclude.The No.10 coal and limestone of Taiyuan formation water has hydraulic connection better,so the water of Taiyuan Formation limestone has a certain threat to the No.10 coal mining water inrush.Based on the analysis of drilling date and the actual situation of coal mine,the FLACE3D software is used to simulate the failure of coal seam floor in the process of No.10 coal mining.When the coal seam dip angle is 10 degree and the width of working face is 180m,the largest destruction depth in the mining process can reach 16-18m.After carefully analysis of the various factors affecting the floor of coal seam mining,the watery of aquifer,the water pressure of aquifer,the equivalent thickless of aquifuge,the thickness ratio of brittle rock and plastic rock of aquifuge,the desity of fault,the intersection and endpoint of the fault and the scale of the fault are the seven main controlling factors of the evaluation of water inrush in No.10 coal mining.For each of the main factors through the GIS software to generate the thematic map of the impact factors and the normalize map.From the thematic map and the normalized map we can clearly see the impact of each factor.The AHP method is used to contrust the judgment matrix of each influencing factor,and the weight of each factor is determined by the calculation of the matrix,and the prediction model of water inrush from 10 coal floor is established.At the same time,the function of the superposition of various thematic maps by GIS powerful spatial processing formating the zoning map of water inrush vulnerability evaluation of No.10 coal floor and establishing the vulnerability index partition threshold.The study area of No.10 floor water inrush risk is divided into five levels:the safety zone,the safer zone,the transition zone,the slightly dangerous zone and the dangerous zone.We conclude that the dangerous zone and the slightly dangerous zone are mainly distributed in the North and the South of Suntuan mine.Finally selecting the actual water inrush points and projecting to the partition map of vulnerability assessment to check the model.The results show that the fiting is well and the vulnerability index model is in accordance with the actual situation.The evaluation result is ideal.