ABSTRACT

As a part of the Lyon-Turin railway link project, the Saint-Martin-la-Porte (France) access gallery (SMP2) has been excavated through a highly squeezing Carboniferous formation. The anisotropic time-dependent behavior of the access gallery has been widely studied, particularly through convergence measurements during and after excavation. Recently, a new survey gallery (SMP4) started to be excavated along the direction and at the depth of the base tunnel. The excavation is accompanied by extensive monitoring including convergence measurements. Considering that the tunnel crosses the same Carboniferous formation, highly squeezing behavior was expected. In this paper, we test the predictive capabilities of the convergence law proposed by Vu et al. (2013) for SMP2 by analyzing the convergence data of SMP4 and by extrapolating the parameters calibrated on SMP2 to SMP4.