A new system for the construction of large shallow tunnels by microtunnelling technology.
L. Grillo, F. Alessandrini, R. Meriggi.
The article describes the results of a numerical analysis intended to simulate the behaviour of an elliptical tunnel lining which has been installed using a new methodology able to reduce drastically the phenomenon of subsidence.
The innovation of this method, called the “pre-assembled shell”, is the construction method of the lining, consisting of high-resistance reinforced concrete tubing inserted into the ground by microtunnelling technology.
The tubing elements are suitably connected to each other both longitudinally and transversally, to create a highly rigid and stable lining, before the excavation of the ground from within the cavity.
The results of the analysis have highlighted a rigid behaviour of the lining with small ground subsidence, which could make this technique particularly suitable for large tunnels with small degrees of cover. © 2001 Elsevier Science Ltd. All rights reserved