The third rubber dam of the Baihe River is directly located on the riverbed. The stratum of dam-base mainly consists of the coarse and gravelly sands. It is also saturated with water and has a strong permeability. Because the dam was ever damaged by water
a new hanged vertical curtain
which was on the verge of a longer impervious blanket concretes
was used to prevent seepage. It is proved that the technique is feasible in the coarse and gravel sands by testing and construction the gunite pile technique. The problems of outflow slurry
emitting slurry and containing sands are also discussed.