Numerical simulation study on the tunnel excavation

In order to shorten route and increase road grade, tunnel excavation road scheme will be widely used in mountain area, so tunnel stability will increasingly become important problem for design and construction. In this paper mechanical behavior of tunnel is simulated by FLAC during road tunnel excavation and support with three-dimensional Fast Lagrangian Method. It indicates through numerical simulation that regularities of distribution of displacement and stress in wall rock and supporting structure can be obtained in dynamic excavation by steps and support by steps; at the same time distribution and failure mechanism of plastic zone of wall rock is given about three different phases of without support, first support, second support.