ABSTRACT
Tunnel segments, placed by means of a tunnel-boring machine (TBM), are subjected to high local forces during construction. The TBM pushes itself of against the already placed tunnel elements. The thrust jack forces working on the tunnel segments introduce splitting stresses that can lead to damage. A possible solution is to use steel fibres as splitting reinforcement.
An experimental research program has been carried out which involved small control elements to characterize the post-cracking behaviour of the material, as well as medium sized and large-scale elements to test the real structural behaviour. Calculations by means of physical models as well as finite element models have been done to predict the experimental results.
The conclusions of the research program are that the bearing capacity of SFRC tunnel linings in Serviceability Limit State (SLS) is comparable with ordinary reinforced concrete and the growth of crack widths is decreased in SLS.
