Analysis on water and soil gushing accident occurred in deep mine air returning shaft during freezing construction

in order to discuss the causes of water and soil gushing accident occured in a ground frezing construction of a mine shaft.based on the Norh No. 3 AirReturning Shaf of Pingmei No.1 Mine a er large abnormal and large with and depth cracks were appeared on the mine concrete lnr n comtbinaton with the site neasured data geological onditions and construction technology,a comprehensive analysis was conducted on the wa1er and soil gushing a ident .The analysis resuts showed that the major causes of the water and sall gushing accident were 1 the construcion fechnology was irationa.such as the rezing pipe borehole was too delecton.the grouting prssure was too igh.the concrete pouring was not continuous and the constrution cold joits ocured, overchaging of the exphosive lcaded caused lbration and theconcrete before and afer the fial sting would cause theloading cracks 2 the concrete mixing rato.,producton and curing were rational such as the .oncrete coud notreach the actal designed strength grade and no production and curing measures conducted,therefore lage area concrete qualt could notreach thedesigned requiremens.such the shrimkage crack 3 thelimitation of the geological co diton,he roce at the accident secion was broken,the igh angle cacks were develope.the crack pressurized water pressure was too high and the structural stress was too high .Mfeanwie the crack rssurzed water were in apoint comnection or inalinear connection with the outside of the mine sheaft and thus stress concentration occurred and the stablity lost of the cross-section was occurred.