ABSTRACT
The new Lyon-Turin railway project involves the construction of a 57 km twin-tube tunnel between France and Italy. Pini France and Systra-SWS are the designers of the construction site 8 (CO8). This part of the project includes the construction of the tunnel portal on the Villard-Clément platform, two 2.8 km long tubes of the base tunnel in the direction of Saint Martin la Porte, the cross-passages between tubes and the niches.
This paper presents the general approach followed to design each temporary support for the base tunnel, cross-passages and technical rooms. The design of the primary lining profiles deals with the variability of the ground and water conditions, the excavation attended behaviour, the construction planning and the identified geological hazards that could be encountered along the alignment.
Particular attention is paid to the intersections between the tunnels both in terms of numerical modelling and construction methods and phases. Two types of intersections are present in the project: the one between the cross-passages and the base tunnel and the one between the cross-passages and the technical rooms. 3D models have been developed for the tunnel intersections.
