Abstract: Well built engineering|Surface pre-grouting|Water control|Clay slurryThe water contents of quaternary system of the southern part of Sijiaying iron mine is rich. The freezing method is taken as the construction method in sink wells. The surface pre-grouting method is used to deal with the water in the bedrock fissure in sink wells and the ratio and function of clay cement grout and the influence of each other are analyzed, so, the suitable ratio of grout is acquired. On the whole, the bedrock fissure water inrush is well controlled.

Key words: Well built engineering, Surface pre-grouting, Water control, Clay slurry