Study on multi-factor complex analysis method applied to watery of sandstone in Zhiluo Formation

According to the water disaster prevention and control problems of the sandstone roof in Zhiluo Formatior of Shaanbei Jurassic Coalfield,based on the roof water inrush occurred in Ningtiaota Minefield as a case,the paper analyzed thee factors of th aquirerthckress of the sandstone.the sand-nud sone compostinand the weathered sandstone affected to the watery of the sandstone aquifer in Zhiluo Formation.Baed on the muiti acor complex analysis method,he ltnology stuc:ure index of Zhiluo Formation,the sand and mudration coefcient and sandstone weathering rate were detemined tothe watery weighting of the acufe in the sandstone and the watery grade valuation scope of the sandstone in Zhluo Formation.The studlyresultshowed that th ltholgy structure indexcoud wel efet the porositypermeability and partcle size of the aquifer n the sandstone affected to the watery.The muti factor complex analysis method was appied todeemine that the weightingcoeficient of the threeinfuence factors were 0.3,0.3 and 0.4 indidualla.According to the weighting resuli the watery zone could be dided to three grades of strongmedum and weak. Among them O ~ 1.6 would be a weak water zone,1.6 ~ 2.3 would be a medium watery zone and 2.3 ~ 3. woul be a trong wvalery zone.The srong water region would be mainly located in the south part and the centralwvest part of the minefeld and some part of the north-east par.The watey medunregion woud be mainlylcated in the central part of the minefeld and the majof region of the norh part n the south and north wings of the mine fel , there would be a relative weak watery zone indidually.The dided zone predicted results and the mine actual oof water inush region would have a good cons istency and could provide an ef.cie prediction access to prevent and control the roof water disasters occurred in the North Shaanxi Jurassic Coalfield.