Safety Pillar Design For Coal-caving Under Aquifer Of 83 Mining Area,Yuandian No.2 Coalmine

This article studies how to design the safty pillar for coal-caving under loose aquifer of 83 Mining Area Yuandian No.2 Coalmine.This paper systematically collects relevant hydrologic and geological producticve data,and conducts scientific analysis of the distribution law of the aquifer and aquifer,combined with the scientific analysis of physical and hydrologic properties parameters,and gets the following results.At the bottom of the loose layer,the water isolation layer(the third aquifuge)is thick and stable,which can effectively isolate the hydraulic connection between the upper and lower aquifers.The bottom aquifer(the fourth contained)is weakly water rich and has poor permeability.Referring to the "three cases" mining standard,it is the II level.The 83 mining area Yuandian No.2 Coalmine bedrock section and weathered zone have good water isolation,and the type of overlying rock is medium hard.On the basis of the specifications of the “three cases” mining standard and the coal mine control water manual,the measured values of the mine are referred to.By collecting a large amount of measured data of mine samples,to build mathematical BP neural network model and FLACD3 D coal mining modele,in order to research roof damage "two strips" features,and reasonable coal pillar height and the height limit of mining of the 83 Mining Area Yuandian No.2 Coalmine.Finally through the risk evaluation of water inrush on roof results the verification of the safety factors.The results of the study determine the new mining upper limit,which is of guiding significance to the safety and economic mining of the mine,and to some extent save the valuable resources of the country.