ABSTRACT
The Western Swiss area has evidenced an increasing urban growth over the recent years. To meet population’s need, the Swiss Federal Railways has planned for a strategic use of underground space in Lausanne, one of the major hubs of the region. A new utility tunnel of about 625 m long and 2.5 m internal diameter is constructed, using pipe-jacking and microtunelling, to reroute the control cables in a newly designed infrastructure at the main train station. Key challenges include tunneling in a very dense urban area and in a geology with possible presence of swelling rock. Time-dependent numerical analyses with advanced elastoplastic constitutive models are carried out to assess swelling behavior of rock. An extensive monitoring of the jacking and TBM performance allowed to reasonably manage the possible risk situations. A close coordination between all urban management parties and services is a success key of the project.
