Abstract: In light of the investigation of current design specifications and open-cut tunnel projects, the waterproof construction method and theory of deformation joints are summarized. Based on the principle of combination of water blocking with draining for the deformation joints, a drainable waterstop may be used to enhance water tightness for tunnels near the sea as well as for submerged tunnels. Considering the geological conditions and requirements for the open-cut section of the Gongbei tunnel, a drainable waterstop may be used for the waterproofing of deformed joints, and a drain pipe junction is designed for the inner side of the tunnels and used as the drain path for leakage water.