Hydro-mechanical modelling and analysis of multi-stage tunnel excavations using a smoothed excavation method

The main objective of this article is to provide a general numerical approach for the hydro-mechanical (HM) modelling tunnels excavated in saturated rock masses exhibiting plastic behaviour, considering multi-stage excavation process. First, new method has been proposed and implemented software CODE_BRIGHT, based on finite element method. In method, stresses elements are reduced smoothly. As verification, principle uniqueness tested excavation. Then, studies have carried out verify advantages calculation, showing that improves computational efficiency mitigates convergence issues. Hence, can solve usual difficulties related problems and, therefore, it allows more in-depth analysis HM behaviour during tunnel Moreover, results obtained CODE_BRIGHT using compared with existing solutions longitudinal deformation profiles (LDP), including elastic–plastic mechanical elastic problems. Furthermore, presents masses, analysing sensitivity LDP conditions mass quality. Finally, large amount data from simulations, empirical –in steady-state framework– by fitting non-linear curves normalised radial displacements occur ahead behind face. attempts convenient set alternatives preliminary design masses.