South Toulon tube: 3D numerical back-analysis on in situ measurements

摘要

Full face excavation with ground reinforcement has become a common technique to build largerntunnels in soft rock or hard soil. Nevertheless, at the design phase, it remains difficult to assess the effect of therndifferent construction and reinforcement elements on the control of the ground movements and settlements. Inrnorder to improve the understanding of ground response to this tunnelling method, a monitoring section has beenrninstalled during the construction of the south Toulon tunnel (France). An important database was obtained andrnsubsequently used for numerical back-analysis.A3D FE calculation, modeling the real reinforcement system andrnconstruction stages, was then performed. The satisfactory matching between the numerical results and the in siturnmeasurements shows that the three-dimensional numerical model with an explicit modeling of the reinforcementrnelements is a reliable tool to simulate the complex phenomenon of interaction between the excavation process,rnthe reinforcements and the ground reaction.