ABSTRACT
In urban tunnel design and construction, one of the major issues is to minimize the surface settlements, which can generate serious problems on existing civil structures. As part of the extension of Paris metro Line 11, a shaft and a test tunnel were realized to improve the understanding of ground response of the Sanoisian “Green” Clay. In this paper, the authors present a 3D numerical back-analysis simulating the tunnel excavation. The study main objective was to best simulate the work carried out in order to calibrate the geotechnical model on the observed in situ measurements. The undrained effective stress approach coupled with consolidation analysis approach was the key to the success of the study which permits to fit the in situ measurements and to determine the geotechnical parameters, to be used in executive studies.
