Novel insights from monitoring-data-driven analytical mechanics of tunnel structures

Abstract

Uncertain ground parameters entering numerical simulations in tunneling typically imply significant gaps between model predictions and corresponding real-time field data. As a remedy, hybrid methods directly couple in-situ geodetic displacement data with advanced shell mechanics, so as to convert recorded lining deformation into utilization degrees. While traditional approaches rely on the ad-hoc choice of spatial displacement interpolations, recent advancements under the “Rail4Future Project” use analytical displacement solutions from aging viscoelastic shell theory, providing not only the shell utilization, but also the ground action. When applied to recent large-scale tunnel projects, ground shear mobilization and shell flexibility including plastic hinge formation turn out as critical structural characteristics of the New Austrian Tunneling Method (NATM). As regards tunnel boring machine (TBM)-driven linings monitored by vibrating wire sensors providing strain data, non-asymptotic concrete creep is the key to successful utilization determination for up to 150 years. While these results rely on tailored grid-point models, future work will employ Fourier-series representations of ground actions, so as to transition the current computational tools into a high-throughput monitoring platform compatible with advanced sensing technologies.