Analysis of cracking in tunnel lining segments

The article describes the study carried out with the purpose to seek the probable causes that have provoked an overall systematic description of the cracks in the works of covering for the tunnel dug with TBM and covered throw prefabricated structures in armed concrete. First of all, it is analysed carefully the overall systematic description of the cracks and in addition the operating methods of excavation and covering. This analysis allows to underline that the reasons for the cracking phenomenon are to return several factors connected to ground conditions and to the presence of layer, to work conditions and to static aspects of the covering. In underground works realized with cutter, these factors are closely related and strongly linked together and lead to undesired effects, in the adverse coincidence.