Abstract:

The excavating tunnel has an adverse effect upon the excavated tunnels during the construction of multiple adjacent tunnels. In this paper, the typical crosssection of the connection section between Line No. 5 and Line No. 6 of Tianjin Metro is analyzed by means of FLAC3D software; and then the interaction of excavating the four adjacent shield tunnels in waterrich stratum is simulated. The results show that: 1) The excavated tunnels incline to the excavating tunnel. The vertical displacement of lowerlaid tunnel is more obvious than the horizontal displacement. 2) The ground surface settlement and the settlement scope induced by lowerlaid excavated tunnel are larger than that induced by upperlaid excavating tunnels under seepage action; and it is proved that the influence of seepage action on waterrich ground settlement and settlement scope are larger than those of excavation stress releasing.

Key words: shield tunnel, fourtunnel converging, FLAC3D, seepage action, ground surface settlement