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Tunnel pre‐support using pipe umbrellas – Technical developments and their advantages
Author(s) -
Volkmann Günther M.
Publication year - 2018
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.201800035
Subject(s) - quantum tunnelling , engineering , simple (philosophy) , tube (container) , connection (principal bundle) , current (fluid) , field (mathematics) , mechanical engineering , structural engineering , electrical engineering , materials science , philosophy , optoelectronics , mathematics , epistemology , pure mathematics
Pipe umbrella support systems have been used successfully for tunnelling in challenging ground conditions since the 1970s. The single umbrella pipes are installed stepwise and parallel to the later installed saw‐tooth shaped primary lining by connecting pipe pieces to each other. The connections are the weakest link of the support system, so recent developments in this field also have an effect on system performance. The development of both machinery and connection types have a major influence on pipe umbrella design for tunnelling. This includes not only simple parameters like installation length or tube dimension but also the connection type. So a conventional pipe umbrella design is not as cost‐efficient as current technical possibilities allow, because material as well as time savings are missed. This article explains possible optimisations for pipe umbrella supported tunnels with simple examples to show cost‐optimised design principles regarding time and material.