An Anisotropic Model for the Numerical Analysis of Tunneling-Induced Settlements in the Paris Area

Abstract

In many cases, numerical simulations cannot accurately predict the settlements induced by the construction of shallow tunnels: the settlements troughs obtained numerically tend to be wider than the observed ones. This can lead to underestimating the differential settlements and thus the potential damages to buildings above ground. This article proposes an elastoplastic model aiming to improve the results of finite element simulations and more precisely the width of the settlement trough. The key feature is the introduction of transverse isotropy in the elastic part of the model. The model makes it possible to clearly identify the influence of each parameter on the mechanical behavior. In particular, one of the parameters controls the shape of the settlement trough. The model was implemented in the finite element code CESAR-LCPC and used to model the settlements observed during the construction of a tramway line in the outskirts of Paris. The results show the effectiveness of the proposed approach.