Numerical analysis and risk assessment on face stability of large-diameter tunnels

Abstract

For the two types of shield tunneling such as Slurry and EPB shield the stability of tunnel face depends on the prevailing support pressure. The support pressure at the tunnel face has to be applied to a value that gives as well sufficient safety against a collapse of the tunnel face as the against uplifting. The paper aims at a better understanding of the mechanics of face failure for those lager-diameter tunnels. And some different determination methods of the applied support pressure are compared and given a risk assessment, which are illustrated their application by numerical analysis in the Yangtze River Tunnel of Shanghai. © Springer-Verlag Berlin Heidelberg 2007.