Studying the Interaction of Drilling between Twin Tunnels of Inter-City Subway in Isfahan

Category Engineering Geology
Group GSI.IR
Location 3rd Iranian rock mechanics conference
Holding Date 10 March 2008
      The increase in vehicles number and their long life and then the air pollution rising, make the subways very important. Therefore, construction of subway and establishing of inter-city train for a metropolis such as Isfahan is necessary. In this project, with respect to simultaneous construction of two parallel and similar tunnels with diameter of 6.5m and axial spacing of 20m, we have studied the interaction of drilling between these two tunnels. In addition, modeling is done with numerical finite element software, Plaxis 7.2. Tunneling method was NATM and drilling and linings installation in twin tunnels was divided to six phases. In this paper, the interaction of drilling between first and second tunnels at the end of sixth phase is investigated. The study focused on some parameters such as horizontal and vertical displacements of rock mass and stresses around the openings. The preliminary results indicated that the interaction of drilling between two tunnels is at low level and has no effect on the advance and design of supports.
   Keywords: Interaction of Drilling, Twin Tunnels, Plaxis software, NATM Tunneling Method