Abstract

Tunnelling in difficult ground conditions induces high loads in the installed support, up to the point where ductile support concepts have to be considered. The usually installed shotcrete lining is subjected to very high strains during its ongoing hydration process, hence resulting in a very complex rheological behaviour. Only the combination of the spatial displacement development with the effects of strength development, stress-dependent non-linear creep and shrinkage of the shotcrete allows plausible prediction of the shotcrete lining's bearing capacity and its final stability. The method developed by Pilgerstorfer is used to predict the spatial development of the displacements, while the flow rate methods by Schubert and Aldrian are used to model the rheological behaviour of shotcrete. A calculation algorithm based on the assumption of displacement compatibility between the surrounding rock mass and installed liner is presented. In order to illustrate the predictive ability and importance of the method, two case-studies are performed and discussed.

This content is only available via PDF.
You can access this article if you purchase or spend a download.