控制性帷幕灌浆防渗技术在土石围堰中的应用

洪家渡电站围堰为不过水土石围堰，防渗处理采用了控制性帷幕灌浆技术，该技术是近两年在临时挡水围堰的防渗墙建造过程中形成的，因其在抛填层、河床沙砾层及基岩层的防渗墙建造过程中“可控性好”而得名．其原理与常规水工建筑物水泥灌浆相同，差别主要在施工工艺和浆液配合比上．主要优点是设备配置简单、施工工艺简单、施工功效较高、工程造价底，适宜于山区河谷地带堤防和临时挡水围堰的所有地层．

Application of controlled curtain grouting impervious technology in embankment cofferdams

The cofferdam of Hongjiadu Hydro Project was selected to be a non-overflow embankment structure with controlled curtain grouting technology for impervious treatment. The technology developed for the recent two years to construct some cutoff walls of temporary cofferdams was a well-controlled impervious method for treating damping fills, sand-gravel river beds and rock strata. The principle was the same as the ordinary cement grouting for hydraulic structures, but there was a difference in their construction technologies. The method was chosen essentially for ease of equipment installation, simplicity of technology, high efficiency of work and low construction cost, and it will be suitable for circumstance of dykes and temporary cofferdams in mountainous river conditions. This paper addresses different problems concerning the above technology and related construction.