ABSTRACT
The construction of Bored tunnels in soft soil will lay a stronger demand on the flexibility of a tunnel lining than in hard soil. In order to enhance the understanding of this, and in order to develop the appropriate models for tunnel design, the failure modes of a tunnel lining are looked at. Subsequently an overview of feasible models is given; i.e. from analytical ring models, to subgrade reaction models, and Finite Element models. The development of longitudinal stresses; bending moment in the tunnel tube, and 2nd order effects in the ring action are discussed. Finally some of the measurements from the monitoring of the 2nd Heinenoord tunnel are evaluated. From the measurements it came forward, that understanding of the inaccuracy of installation of segments in a tunnel lining is at least as important as the mechanical model chosen.
