南水北调配套大宁水库基岩帷幕灌浆试验

Bedrock Curtain Grouting Test in Da′ning Reservoir of the South-to-North Water Diversion Project

以北京市南水北调配套大宁水库工程塑性混凝土防渗墙下基岩帷幕灌浆试验为例,从灌浆试验区地段选择、灌浆压力初选、浆液比级、灌浆分序、灌浆方法、灌浆效果检查等方面对灌浆试验方案设计进行了全面阐述,并对试验过程中获得的数据进行了"不同孔序灌前与灌后压水透水率Lu值、单位注入量与不同孔序之间的关系、检查孔与先导孔灌前压水透水率Lu值以及检查孔各段透水率Lu值"共4个方面的统计分析。根据统计分析结果,结合试验过程中随上部防渗墙抬动而调低灌浆压力值的情况,确定了大宁水库工程基岩灌浆施工所需要的施工参数,为正式进行灌浆施工提供了技术实践基础。

According to the bedrock curtain grouting test of the plastic concrete cut-off wall of the Da′ning reservoir at Beijing Section in the South-to-North Water Diversion Project,the grouting test scheme is illustrated from the aspects of the selection of grouting test locations,grouting pressure,slurry flux proportion,grouting order,grouting method,and effect checking of grouting.Moreover,the statistical analyses on four aspects are obtained,which include the pressure water permeability values（Lu） before and after grouting with different hole sequences,the relationships between the unit infusing volumes and different hole sequences,the pressure water permeability values（Lu） of the inspection holes and pilot holes before grouting,and the water permeability values（Lu） in each section of the inspection holes.Based on the results from the statistical analyses and the decreasing grouting pressure with the lifting of the cut-off wall during the test,the construction parameters for the bedrock curtain grouting of Da′ning reservoir are determined,which can provide the technical support for the grouting construction.