ABSTRACT
Tunnel design requires the quantification of deformations induced by excavation. The increasing number and complexity of calculation methods requires a quantity of information that cannot simply be applied to large areas. Thus, a simple method provides a density of results suitable for urban infrastructure projects is necessary: the contraction rate method enables the convergence of excavated soil to be modelled in a single calculation step. This method has been used to design around 50 km of tunnels around Paris, including the tunnels of the Line 16 of Grand Paris Express and EOLE projects. Now that these projects are completed, a critical analysis of the method is a fundamental step for the designs’ reliability. The conclusions and confidence intervals can then be considered to future projects in the Paris region, and the approach presented here can also be proposed in other geological contexts as a complement to other usual methods.
