关键词: 地面预注浆, 黏土水泥浆, 注浆量, 注浆段高

Abstract: The ideal result of water prevention was obtained in surface pre-grouting for 1# auxiliary shafts of Dajiazhuang Iron Mine.From analysis and optimization of the design，the number of the grouting holes can be reduced to 10 or 8，with grouting quantity and grouting times assured.The main grouting material was single-liquid cement slurry and clay-cement slurry，Which was low cost，no pollution，high water shutoff rate and good durability.Grouting pressure should refer to Code for Acceptance of Shaft Sinking and Drifting of Coal Mine（GB50511-2010），and the upper limit should be taken over the pressure range in the process of construction.The grouting section was divided into several intervals according to geological conditions and the type of grouting material to be grouted，and the grouting quantity was calculated in each interval using the most suitable parameters.The effective dispersal distance should not less than 10 m.The depth of aquifer，aquifuge and fracture zone should be considered in the division of grouting intervals.And it needs be adjusted according to geological conditions exposed by grouting holes.

Key words: Surface pre-grouting, Clay-cement grout, Grouting quantity, Grouting intervals