Abstract: The research is based on the western tunnel crossing the Liuyanghe river.Ansys software is used to simulate the three-dimensional excavation with CD method.The displacement data of tunnel vault obtained is  compared with the real data.The displacement characteristics and charge regularities of this project are summarized.The research provides reference and experience for the future similar project.The results show that:the vault displacements change slowly with space location;the soil consolidation is better,the vault displacement is lower;Reinforcement area is appropriate,the seepage is good to vault displacement.

Key words: river-crossing , tunnel;displacement of tunnel vault;CD method;three-dimensional finite element