Time-dependent tunnel deformations in homogeneous and heterogeneous weak rock formations

摘要

To investigate long-term, time-dependent tunnel deformations, this study employs a non-linear theological model capable of considering the tertiary creep behaviour of the rock mass (Okubo and Fukui, 2006). A model parametric study is undertaken with a 30 numerical model encompassing a tunnel. The results show that the tunnel walls start to deform at an accelerating rate after a lapse of ten years. The results offer an explanation to previously reported tunnel instability cases. A 3D numerical model encompassing weak rock formation obliquely intersecting with the tunnel is then constructed. The analysis yields asymmetric wall deformation pattern, suggesting the need for optimizing rock supports. (C) 2017 Elsevier Ltd. All rights reserved.