Abstract

The development of urban mobility implies the construction of tunnels, often interacting with valuable historical structures. It is thus necessary to develop rational and reliable procedures to estimate the potential excavation-induced damage, dealing with complex soil-structure interaction problems. Classical approaches are often characterised by relatively simple schematisations for either one or both components of the problem, as, for example, springs for the soil or equivalent plates for the structure. Such simplified assumptions prove to be appropriate for simple soil-foundation cases, while show several limitations when tackling more complex problems, as those involving the excavation in the vicinity or beneath historical masonry structure. In such cases, the need for reliable prediction of the potential damage on surface structures induced by construction activities justifies the adoption of advanced numerical approaches. These need to be based on realistic constitutive assumptions for both soils and masonry elements and require the definition of the three-dimensional geometry as well as an accurate modelling schematisation of the excavation process. In this paper a 3D Finite Element approach is proposed to model in detail the excavation of twin tunnels, accounting for the strongly non-linear soil behaviour, interacting with monumental masonry structures, carefully modelling their geometry and non-linear anisotropic mechanical behaviour. The work focuses on a specific case-study related to the ongoing construction of the line C of Rome underground.