Abstract:Compared with bored pile,underground diaphragm wall is an environment friendly way with some advantages,such as low disturbance and high efficiency. Impervious wall of plastic concrete is adopted for its combined action with the earth dam. The construction scheme and technique,used in the anti-seepage treatment of Bayi reservoir dam,are introduced,with a method of dealing with special underground structure inside the dam. Efficiency is improved through adoption of interleaving constructing and optimized scheduling for equipments. Further study on impervious wall of plastic concrete is needed.