ABSTRACT
In conventional tunneling, shotcrete is often one of the main support elements and its failure can potentially lead to a collapse. Therefore, in geotechnical monitoring, the definition of the shotcrete stress is essential, even more in squeezing rock mass conditions, where the large deformations that occur can generate relevant stresses in the lining and reach the limit of its resistance capability. This paper presents a “two-step procedure” for the evaluation of shotcrete stress of the primary lining based on the convergence measurements. Although the method can provide only a first estimation of the shotcrete stress, it has proven to be very effective when applied to the case study of the Periadriatic fault at the Brenner Base Tunnel. Very interesting results regarding the shotcrete behavior in squeezing rock mass conditions have been obtained.
