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Why were 800 m of the Boßler Tunnel built twice? – TBM passing a shotcrete section
Author(s) -
Goldberger Harald,
Esslinger Christoph,
Lützerath Thomas,
Müller Jörg Rainer,
Galli Mario
Publication year - 2017
Publication title -
geomechanics and tunnelling
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.317
H-Index - 18
eISSN - 1865-7389
pISSN - 1865-7362
DOI - 10.1002/geot.201600074
Subject(s) - shotcrete , drill , section (typography) , new austrian tunnelling method , precast concrete , engineering , geology , geotechnical engineering , structural engineering , mechanical engineering , computer science , excavation , operating system
Impermeable tunnels are usually built conventionally with drill and blast or excavators followed by an inner lining or by mechanized tunnelling method with a segment lining. A combination of both methods on certain sections is commonly used for large tunnels due to geological and geotechnical considerations. The construction of the same section with both methods is not common and seems bizarre. However, this is exactly what happened at the 8.8 km Boßler Tunnel, part of the new high‐speed line Wendlingen–Ulm. Due to a section of about 800 m built by drill and blast as well as geological explorations, the mechanized tunnel drive could be extended. So a solution had to be developed to enable the TBM to pass through the existing tunnel. Design, economic, contractual and technical issues were considered to obtain the best solution: the TBM passed through the existing shotcrete section cutting replacement soil, followed by the installation of precast tunnel segments.