Abstract: Shenglongxia Open-pit Mine in Qian'an County, Tangshan City is adjacent to Lu'an River.Due to the sufficient underground water supplement and loose slope structure, the conventional grouting method can not meet the requirements of both earth retaining and water blocking.In view of this case, a consolidation scheme based on diaphragm wall was selected.It is known from FLAC numerical analysis and site monitoring data that the safety factor is only 0.83 when the excavation is made without consolidation and the predicted rush-in water in the whole pit is as high as 23 000 m³/d.The safety factor is 1.37 when the excavation is made after consolidation and the maximum rush-in water is only 1 000 m³/d, fully demonstrating that this scheme can effectively play a role of earth retaining and water blocking.It is the first international case of applying diaphragm wall in open-pit mine, and therefore, is of the value of wide spreading.

Key words: Diaphragm wall, Open-pit mine, Consolidation, Water blocking