Development of a guideline for cross passage junctions in segmental lined tunnels

The connection between tunnels and cross passages places high demands on support and safety measures, especially for mechanized tunnelling with segmental lining. The critical task is to develop a temporary support system during the opening of the precast segmental lining until the inner lining of the cross passage has developed its full bearing capacity and is acting as a final support measure. For singleshell tunnels with waterproof linings, the serviceability of a durable waterproofing connection has to be ensured. A working group initiated by Austrian Federal Railways (ÖBB) has been concentrating on the opening of cross passages in TBM tunnels. The result of the research will be summarized in a guideline for the design of cross passage openings in tunnel with segmental lining. The guideline will describe the different systems already used for various scenarios according to the state of the technology. The paper summarizes the current state of the guideline and provides some recommended systems for lining support, waterproofing systems as well as some fundamental structural design models for the different support and coupling elements. © 2019, Ernst und Sohn. All rights reserved.