Full scale study of pile response to EPBS tunnelling on a Grand Paris Express site
Résumé
This article presents a full-scale experiment on the effect of EPBS tunnelling on pile foundations in the Paris area. Three cast in-situ piles, instrumented with strain gauges and optical fibre cables, were installed at different distances from tunnel axis with various pile base positions to monitor pile strains as the EPBS progresses. This paper investigates pile – soil differential settlements at ground surface, axial load variations, shaft friction mobilization, base load variations, bending moments and pile structural failure possibility. The pile behaviour changed depending on the pile position with respect to the tunnelling machine, with the main changes occurring during the passage of the EPBS beneath or at pile level. Estimation of pile behaviour based on simplified modelling was confirmed by the field monitoring.