Roof Water Disaster Assessment And Prevention Of 2~# Coal In A Coal Mine In Jizhong Energy

Mine water inrush from sandstone roof is one of the main types in coal mine diraster,it is seriously affected the operation of coal enterprises,and it is also a great threat to coal mine safety in production.Because of the complexity of underground structures and the diversity of geological conditions,the evaluation and control of roof water damage in coal field has been a difficult problem for coal mining in China.The mining area,which is a larger roof water of mine in the North China,is undered the jurisdiction of Jizhong energy.And it is represented that the water inrush type and characteristics for the North China-type coalfield.And it is of great practical significance to provide correct and intuitive evaluation basis for coal mine safety.This paper took an coal mine in Jizhong energy,Hebei province,as the research object,to study the roof water disaster assessment,not only has a provide the correct and intuitive basis for coal mine safety mining,but also has a certain practical value.On the basis of analyzing the geological conditions,combined with drilling data,it established the 3D hydrogeological structure model of the Permian stratigraphic at mining area with GMS,and systematically analyzed the water-resisting layer characteristic of mining area from east-west,south-north directions and combination sections.The result shows that,the stratum formation in the southwest is shallow,and the weathering is more serious,exposing the coal strata in the Shanxi Formation.And the deep burial in the northeast,the weaker degree of weathering,and exposing the strata of the Shiqianfeng Formation.From the southwest to the northeast,the strata of the Permian are gradually exposed,and the thickness of the strata is gradually increased at the top of the model,and the thickness of the lower strata tends to be stable.The thickness of the water-bearing aquifer in the Shanxi Formation is about 45 m,and the distribution is evenly distributed.The thickness of the other areas is basically the same as that of the southwest.In the natural state,there is a thin layer of aquifer between the aquifers to block its hydraulic connection,while the lower layer of the lower water-filled aquifer covers a layer of thicker shale aquifers The supply of water and surface water to the coal seam roof directly or indirectly.On the basis of the geological conditions and the 3D hydrogeological structure model,and analyze the factors that affect the roof gushing water or inrushing water,through AHP-entropy weight method to determine the weight of each control factor,and the evaluation model of roof water damage is established.This paper,through the collection and processing of the watermark characteristics and geological structure of the roof,the weight of each master factor determined by the entropy weight method based on objective factors and also been used to determine the main control factor by AHP method based on subjective factors,and To determine the weight of the impact factor of the roof water damage.Finally,the influence factors are coupled to get the risk map of the roof water hazard,which is used the ARCGIS software data processing function.Forecasting by using this theorise and methods,the prediction results show that the latitude is in the safe area between 4050500 and 4052000,and there is a dangerous zone between 4052000 and 4054000,and its area is located in the more dangerous area.At the same time,the current mining of the North four mining area in a dangerous area.Therefore,before the exploitation of the roof of the need for more dangerous areas and above the water damage control.According to the mining situation,we could choose the-500 m alley for roof test,and design hydrophobic drilling group.It is a way of the underground dredging that draining the water in the roof aquifer,to meet the safety needs of coal mining.