Contribution à la méthode convergence-confinement par le principe de la similitude

Abstract

The characteristic lines method is very useful for the design of supported tun- nels in grounds with no time-dependent effects, but has however a drawback. The convergence of the tunnel when the support is installed, in relation to the distance from the front face, remains undetermined. A simple method is proposed in order to get a precise assessment of the con- vergence at the wall related to the distance from the front in the case of an elastic perfectly plastic ground behaviour. This approximation is validated for the usual loading factors. Using this method, final support pressures and final wall convergences are also investigated according to the ground plasticity and the distance from the front where support is installed