Abstract:

Due to the environmental constraints, the central wall of Ziyin doublearch tunnel cannot be constructed in advance. Therefore, the innovative construction scheme of “3heading + connection passage” is proposed and implemented for the tunnel. In the paper, the principle of the construction scheme is presented and the implementation of the scheme in the tunneling is described in detail. Conclusions drawn are as follows: 1) Due to the installation of the connection passages and the conversion of the traffic organization, the central wall has been constructed in advance and rapid tunneling has been achieved; 2) Due to the rational construction sequence adopted, the intensified steel arch support for the connection passage and the strengthened monitoring, the construction safety has been guaranteed.

Key words: doublearch tunnel, pilot heading, connecting passage, rapid construction, traffic organization conversion