小浪底水利枢纽工程防渗墙施工技术

The construction technology of the cut off wall of the Xiaolangdi Multipurpose Project

黄河小浪底水利枢纽工程主坝防渗墙上游枯水围堰防渗墙 ,是目前国内较大规模的地下防渗墙工程。工程施工采用了多种新方法、新技术 ,如 :在国内首次采用先进的双轮铣和机械抓斗组合的成槽设备和技术 ,在深厚覆盖层和复杂的河床地形条件下 ,确保了槽孔的垂直度和成墙质量 ,加快了工程进度 ;在国内首次采用横向槽孔填充塑性混凝土保护下的平板接头的墙段连接形式 ,使用高压旋喷灌浆对“老虎嘴”的封堵方案 ,采用缓凝高强混凝土材料新工艺、新技术 ;引进了国际上大流量、大压力的双重管高压旋喷灌浆技术和先进的钻机及喷浆设备 ,对覆盖层深达 5 0m的地层采用单排桩成墙获得成功。这些新技术、新方法代表了我国当前防渗墙施工技术的先进水平。

The cut off walls for the main dam and upstream dry cofferdam of Xiaolangdi Multipurpose Project are of larger scale underground works in China at present Many new methods and new techniques have been adopted in the construction of the project For example, the advanced groove formed equipment, composed of the two wheel mill and mechanical clamshell, and its techniques have been firstly adopted in the construction of groove type cutoff wall, which ensures the vertical degree and wall formed quality, and quickens the progress of the project, under the conditions of having deep overburden layer and complicated river bed topography The new plate connection way between two wall sections was firstly used at home, in which the cross grooves are filled with plastic concrete in order to protect the joint The high pressure rotary injection grouting has been scientifically used and new material of slow setting and high strength concrete also has been adopted The high pressure rotary injection grouting technology with large discharge and high pressure double pipe and some advanced drilling machines and grouting equipment have been imported For those layers with overlying stratum depth of over 50 m, the single row pile wall was adopted and proved to be successful These new technologies and methods basically represent the advanced level in the cutoff wall construction technology in China at present