Discrete Modelling of Excavation in Fractured Rock by NSCD Method

Abstract

The presence of the network of discontinuities on intact rock is a special feature of nature rock masses. Non Smooth Contact Dynamics method (NSCD), a discrete numerical method with many strong advantages of the study on granular materials and has been recently used in rock engineering. LMGC90, the open-sourced numerical tool of NSCD, has demonstrated robust capacity in the modelling and mechanical analysis of diverse environments, masonry and rock included. In this study, a numerical modelling of a multi-phaseexcavation in fractured rock was realized. The simulation of the tunnelling was conducted with the consideration of the state of the excavation and its neighbouring rock blocks. The obtained mechanical behaviours of the model were analysed, and three failure mechanisms of the excavation vicinity during the tunnelling were aimed. The observed phenomena showed typical effects of two components of the rock mass (rock structure and rock material) to the stability of the excavation and the host rock mass.