Impermeable wall overlapping method used for new and old concrete

The invention provides an impermeable wall overlapping method used for new and old concrete. The method comprises the following steps that S1, an old impermeable wall is previously arranged in a maindam, a rectangular horizontal chiseling port is chiseled in the middle of a construction side, 90 cm away from the upper stream of the old impermeable wall, under the joint cooperation of a grab bucket and a percussion drill, and the rectangular horizontal chiseling port is inserted into the old impermeable wall by 5 m; and S2, a new concrete impermeable wall is poured in the rectangular horizontal chiseling port by means of pouring equipment. According to the impermeable wall overlapping method provided by the invention, the mode that impermeable wall dislocation overlapping and pouring between the new and old impermeable walls is adopted, an impermeable whole is formed by the new and old impermeable walls, and the seepage prevention effect is greatly guaranteed. 本发明提出了一种新旧混凝土用的防渗墙体搭接方法，包括以下步骤：S1：旧防渗墙体原先就是设置在主坝体内