ABSTRACT
Since November 2016, TRACTEBEL and EGIS have been in charge of the design of the metro line 15 East, which is part of the future Grand Paris Express Network. The project that involves a 23km bored tunnel is located in a densely urbanized area and faces various geotechnical risks. In order to manage risks and achieve cost and delay control, necessary geotechnical investigations and building surveys have been carried out by Société du Grand Paris. Detailed modelling of the geotechnical profile was prepared for the continuous assessment of the settlement trough along the tunnel following an advanced methodology, which combines finite element analysis, empirical models and regional feedback from similar projects, to increase the reliability of the predictions. Sources of uncertainty such as face pressure variability and local geotechnical anomalies were considered and combined in several scenarios for risk assessment.
