Grouting Technology for Control of Ordovician Limestone Water

In older to improve efficiency of surface pre--grouting in sealing off water in heavily water-bearing strata, such as sandstone,siltstone and limestone, several methods have been used in China, they are ; intermittent pre-grouting, adjusting pre-grouting parameters and stepwise repeated pre-grouting methods. The paper describes effect of deviation on water sealing in pre-grouting. Deviation correction measures, like mechanical, technological and changing hole position methods have been introduced with satisfactory results in practical engineering projects without increasing the volume of engineering project and without causing delay.