The Study on the Construction Technology of Large-Scale Underground Interchange Tunnels under the Rivers

A Large-scale underground interchange tunnels will be applied in the Chongqing Two Rivers Tunnel project with six crossings and four interchanges adopting NATM. The paper analyzes and discusses the whole-process construction mechanical behavior of the underground interchange by the numerical analysis method, at the same time considering the similar project established, and then suggests some important design parameters about crossings and close overlap interchanges between NATM tunnels, such as proper space of crossings and interchanges. Through the analyses, the paper suggests the design and construction method and construction organization project, especially for the crossings and close overlap interchanges between the NATM tunnels. The paper discusses the key problems of an underground interchange tunnels, and first suggests a mode how to construct an underground interchange tunnels. So, it is important in theory and practical engineering.