三峡二期围堰防渗墙墙体材料水下成型特性研究

Study on characteristic of cutoff wall material moulding under ground water in phase?Ⅱ cofferdam of Three Gorges Project

运用均匀设计方法对三峡二期围堰防渗墙墙体材料的水下特性进行了墙体材料的水下成型试验研究。试验结果表明:防渗墙墙体材料水上和水下成型试件的力学指标具有相当大的差异,水下成型环境下墙体材料的实际抗压强度比同期常规成型试件的抗压强度约低40%～20%,初始切线模量比同期常规成型试件的初始切线模量约低40%～10%,但随着龄期的增长,差异越来越小。这一研究成果为防渗墙墙体材料设计参数的变更及防渗墙的验收提供了科学依据。

In order to study the properties of material of phase?Ⅱ cofferdam cutoff wall in Three Gorges Project, a test of the material moulding under ground water is conducted to compare with that of ordinary moluding. The test result shows a notable difference of the mechanical index of the material between two cases. That is the compression strength of the material with underwater moulding is 40%-20% lower than that of ordinary moulding, and the initial elastic mouldus of the former is 40%-10% smaller than the latter, but the difference decreases gradually with ages. The research result provides a scientific basis to mend design parameters of the cutoff wall, as well as to check and accept the cutoff wall.