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Hygro‐thermo‐chemo‐mechanical modelling of shotcrete during tunnel advance
Author(s) -
Gamnitzer Peter,
Schreter Magdalena,
Hofstetter Günter
Publication year - 2018
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.201800144
Subject(s) - shotcrete , geotechnical engineering , creep , stiffness , excavation , structural engineering , drill , quantum tunnelling , constitutive equation , geology , engineering , materials science , finite element method , mechanical engineering , composite material , optoelectronics
This contribution deals with numerical modelling of drill‐and‐blast tunnelling. Special attention is paid to the modelling of a shotcrete layer supporting the surrounding rock after excavation. Due to an increasing load caused by further tunnel advance, and due to shrinkage caused by hydration which is restrained by the surrounding rock, the shotcrete is loaded in place at a very early age. Hence it is required to accurately model the evolution of its strength and stiffness. This is done using a fully coupled hygro‐thermo‐chemo‐mechanical multi‐phase model for the shotcrete. Creep of shotcrete is taken into account using a microprestress‐solidification approach. The constitutive model for the shotcrete is calibrated using experimental data obtained from laboratory tests reported in literature. The setup for the tunnelling simulation is completed assuming elastic‐plastic response for the surrounding rock and the additional steel anchors. The results of this contribution are considered to be a further step towards a more accurate modelling of excavation procedures in conventional drill‐and‐blast tunnelling.