Research On The Prediction Of Coal Mine Water Inflow Under The Super-thick Sandstone Aquifer

The Binchang mining area is located in the Jurassic coal field of Huanglong,which is mainly affected by the roof water disaster.With the increase of regional mining intensity,the water disaster is becoming more and more prominent.In this area,the hydrogeological conditions are complex.At the same time,in the calculation of mine water inflow,the sandstone aquifer in the Luohe group is generally considered as one aquifer,which neglects its upper and lower stratification characteristics.The calculated results differ greatly from the actual amount of water yield,and the water inflow poses a threat to mine safety.Therefore,in order to ensure the safe and efficient mining,it is urgent to research the damage law of water flowing fractured zone and the accurate prediction method of the mine water inflow.In this research,Tingnan coal mine in Binchang mining area was selected as the research object,and the research was carried out through literature review,data analysis,drilling,hydrogeological test,physical similar simulation and numerical simulation.Firstly,the stratigraphic characteristics of the upper and lower Luohe group of the Cretaceous are studied by analyzing the hydraulic data,the hydraulic connection between the upper and lower strata,the water chemistry characteristics and other data.The results show that there are obvious differences in the upper and lower Luohe group.It is suggested that the aquifer of lower Luohe group should be considered and used as a relative aquiclude.And the average thickness of the upper section is about 190.75 m and the average thickness of the lower section is about 99.61 m.Secondly,the damage law of water flowing fractured zone in this area is studied by field measurement,similar material simulation and numerical simulation.At the same time,according to the typical large-scale structural,"weak-hard-weak-hard"complex roof structure in the area,it is pointed out that the height of water flowing fractured zone is higher.Finally,combined with the above research results,the traditional large well method,the modified large well method and the numerical method are used to forecast the mine water inflow.What's more,the predicted water yield is compared with the actual water yield,and the advantages and disadvantages of each method are analyzed.The results show that the modified large well method is more suitable for this area.