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Approximate time‐dependent analysis of tunnel support structure considering progress of tunnel face
Author(s) -
Sakurai Shunsuke
Publication year - 1978
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.1610020205
Subject(s) - isotropy , face (sociological concept) , hydrostatic pressure , hydrostatic equilibrium , stress (linguistics) , stress field , field (mathematics) , mechanics , homogeneous , structural engineering , engineering , mathematics , finite element method , statistical physics , physics , optics , social science , linguistics , philosophy , quantum mechanics , sociology , pure mathematics
The pressure acting on tunnel support structures generally increases with lapse in time. The pressure increase may be caused by not only the time‐dependent mechanical properties of the underground medium, but also by the progression of the tunnel face. In order to clarify these two effects, three‐dimensional analysis is required. In this study, however, a method which takes into account the three‐dimensional effects of the tunnel face progression in two‐dimensional plane strain analyses is proposedby introducing the ‘equivalent intial stress’. The proposed method can be easily applied to time‐dependent analyses of the behaviour of tunnel support structures installed in a visco‐elastic medium. The tunnels considered here are circular in shape, being driven in homogeneous isotropic linear visco‐elastic media having hydrostatic initial stresses. In the first part of this paper, detailed discussions of the proposed equivalent initial stress are given. The second deals with the mathematical formulations for obtaining closed‐form solutions for the pressure acting on tunnel support structures. In the third, numerical results and discussions are given, and special attetion is paid to the effects of both the time‐dependent mechanical properties of the material and the tunnel face progression. Finally, the theoretical results obtained here are utilized for interpretation of field measurements.