Soil-structure interaction due to tunnelling in soft ground, an equivalent solid approach

This paper presents a partly uncoupled procedure for the evaluation of tunnelling induced damage on historic buildings, focusing on Roman Renaissance masonry structures in particular. Soil-structure interaction is studied through finite element analyses using a simplified model of the examined building, called ‘equivalent solid’. The equivalent solid model consists of the part of the building embedded in the soil and has a transverselyisotropic linear-elastic behaviour, with adequately calibrated moduli. Results of soil-structure interaction analyses show that, as far as the volume loss is in the typical range expected for tunnel excavation with an earth pressure balance shield, the equivalent solid yields approximately the same settlement distribution as a detailed structural model. Then, damage assessment is carried out applying the predicted settlements at the base of a detailed model of the building that takes into account material non-linearity.