三峡工程二期下游围堰防渗墙“两钻一抓”生产性试验

Two-Drill and One Grab" Productive Test for Construction of Stage 2 Downtream Cofferdam Impervious Wall for Three Gorges Project

针对三峡二期围堰防渗墙的施工特点，在下游围堰右岸连接段进行了不同机具和施工方法的“两钻一抓”成槽试验及墙体材料配合比试验验证，对二期围堰防渗墙施工中可能遇到的难点处理从感性认识上有了较为充分的思想准备，并积累了丰富的第一手资料和经验，现场“两钻一抓”生产性试验成果对指导河床深槽防渗墙施工起到了重要的作用。

In accordance with the construction features of the Three Gorges Project stage 2 cofferdam impervious wall project a 'Two-Drill and One Grab' trench forming test and a wall body material mix proportion test have been carried out by using different equipment and methods in the joint section on the right bank of the downstream cofferdam to obtain perceptual knowledge about the potential difficulties in large scale construction of the stage 2 cofferdam impervious wall and thus to be ready to overcome the difficulties. The tests have provided a wealth of first-hand information and data as well as experiences, which play an important role in guiding the construction of the impervious wall in the river bed deep channel section.