ABSTRACT
Both support principles have a different static mode of functioning. The results of FE-analyses for tunnels and the two support principles are illustrated in Figures 5 to 8. The given parameters result from comparative analyses for an investigation gallery in Germany, carried out with the FE-program FEST03 (Wittke-Gattermann 1998). In case the tunnel is well covered with competent unleached Gypsum Keuper and water is only available underneath the invert of the tunnel, the invert is subjected to higher bending in case of a resisting support than in case of a yielding support (Figure 5). Heaving of the tunnel cannot be observed in both cases. The high loading of the shoulders of concrete for the yielding principle is remarkable (Figure 6). It leads to high shear forces in the corresponding area of the inner lining. Nevertheless, the bending moments and normal thrust in the internal lining are lower for the yielding principle than for the resisting principle.
