ABSTRACT
Metro tunnelling for urban transit in densely populated cities with high traffic volumes poses various challenges, one of which is undercrossing operating railway tracks. Ensuring ground settlements remain within permissible limits to prevent any hindrance to railway operations is both challenging and critical. In such cases, detailed 3D analysis is required to understand soil-structure interaction. This paper presents a numerical study to predict ground settlements beneath railway tracks induced by TBM excavation for metro construction in one of the busiest cities in southern India. The excavation of these twin tunnels requires underpassing five parallel operational railway tracks. Additionally, the tunnel alignment features a horizontal curve with a 90-degree turn, marking one of the most significant curvatures to be excavated so far. An attempt has been made to validate the ground settlements obtained from numerical results with empirical method. Furthermore, this paper discusses the on-site real-time monitoring proposed for tunnel construction.
