Experimental study on a 1 G reduced scale model of TBM: Impact of tunnelling on piled structures

© The authors and ICE Publishing: All rights reserved, 2015. Within the framework of a new European project named NeTTUN, ENTPE in Lyon (France) is in charge of a large experimental campaign to investigate the impact of tunnelling on neighbouring piled structures. For this study, an original reduced-scale (around 1:10) physical model of Earth Pressure Balanced Shield (EPBS) is used. This "lg" laboratory model is able to reproduce the main features of the excavation method. In the past, tests carried out with this TBM model allowed a detailed analysis on the soil-machine interaction in virgin soils (Berthoz et al, 2012). For the new experimental program, the miniature EPBS advances inside a large tank filled with a model soil, in which instrumented piles were pre-installed. The objectives of this campaign are: (i) to perform, under well-controlled laboratory conditions and taking into account the 3D effects, assessments of soil-structure interactions that occur during tunnel excavation, (ii) to constitute an experimental database providing a reliable support to calibrate numerical simulation models dealing with tunnel - soil - piles in-teractions.