Treatment method of grouting at the back of sluice wall for abandoned water drainage and supply facilities in underground coal mine:with the north tunnel in 7^th level in Zhaogezhuang coal mine as example

Feasibility analysis, design and construction methods were discussed in detail aiming at using abandoned waster drainage and supply facilities to realize single hydraulic high pressure grouting at the back of sluce wall for the purpose of blocking high pressure Ordovician limestone groundwater.This project adopted high pressure grouting at the back of sluice wall, making efficient and economic treatment in the north water tunnel at 7th level, and achieving considerable economic benefits.