ABSTRACT
The north extension of Paris metro line 12 consists in 3.8 km of double track tunnel and 3 stations, constructed in two main stages. The first stage, between 2010 and 2011, included the tunnel boring with an EPB TBM. The monitoring of settlements was particularly dense and provided a wealth of topographic data. A back analysis based on non-local least square method showed that a very good agreement could be found between a calibrated Peck formula and the empirical data. An inverse analysis allowed to deduce the characteristic trough width parameter of each formation. Eventually, a detailed back-analysis based on finite element modelling allowed to derive a law relating confinement to volume loss. This allowed establishing a predictive model based on Peck formulation complemented by two empirically calibrated laws which is shown to match closely the full data set and could be used on projects currently under study.
