NUMERICAL SIMULATION OF TUNNEL EXCAVATION CONSIDERING TIME DEPENDENT BEHAVIOUR OF ROCK MASS AND THE EFFECT OF TUNNEL SUPPORT

Abstract

Time dependent behavior of rock mass should be considered for the evaluations of long-term stability of tunnel.
In this paper, the FEM analysis based on incremental method was carried out to evaluate the effect of tunnel support, assuming various stiffnesses and setting timings, for long-term stability of a deep underground tunnel in soft rock. Time dependent behavior of rock mass was numerically simulated using compliance variable model proposed by Okubo et al.
The results showed validity of the methods proposed in this paper, and its applicability for design and long-term assessment of tunnel was discussed.