ABSTRACT
The use of the underground has been a growing solution found for the installation of infrastructure and (or) transport networks in the last decades. In these networks it is common to sequentially excavate tunnels in close proximity. Several case studies reported that the deformations associated with the excavation of a second tunnel were higher than those recorded in the first, showing that in this scenario there seems to have an interaction between tunnels. In order to predict the settlement profile induced by the excavation of the second tunnel several methods have been proposed based on numerical, centrifuge and small scale models. In this paper the results obtained with a numerical analysis of the excavation of two twin tunnels are presented and compared against those proposals. The results confirm that the presence of the first tunnel influences the excavation of the second tunnel. Based on a parametric study carried out it was possible to verify that interaction occurs regardless of the depth of the tunnel, though it is strongly dependent on the pillar width between tunnels.
