Assessment of Soil Parameters Met during a Tunnel Excavation: Use of Inverse Analysis on In Situ Measurements — Case of Bois de Peu (France)

In this paper, an optimization method is tested on in-situ measurements carried out during the excavation of Bois de Peu tunnel in France. An important monitoring program was foreseen during this excavation because it was decided to apply the "interactive design method" in order to adapt support in real time. An optimization software, SiDoLo, is used. It is coupled with the finite element software CESAR-LCPC to evaluate soil parameters. Only the identification of the argillaceous unit parameters is presented in this paper. Experimental responses used in the inverse analysis approach and presented in this paper are strain measurements of the soil ahead the face by extrusometers. Numerical responses are obtained by 2D numerical models. This article shows the results obtained according to the number of used experimental responses. It shows difficulties which can be met during the identification of several parameters simultaneously.