Repairing techniques of railway tunnels

The basic aspects of the repairing procedures of railway tunnels are discussed. The first aspect regards the design of a reliable strategy for the diagnosis and the therapy of tunnel damaging. The main operational techniques are presented and discussed in detail. In the second part of the paper the analytical problem connected to the stress redistribution analysis due to the rheological lack of homogeneity of the repaired structure is solved by means of an appropriate algorithm, obtaining refined results without resorting to exceedingly complex calculation. The discussion of an actual case study will illustrate the practical application of the algorithm and the most significant prerequisites of the service behaviour of the repaired structure.