Assessment of the effects induced by mechanised tunnelling on masonry buildings in the urban area of Rome

The growing population and increasing demand for sustainable mobility necessitate the transition of road and rail traffic to underground infrastructure. In urban environments, such projects are often constructed at shallow depths, this emphasising the need to evaluate interactions with existing structures. This issue is particularly critical in Rome, due to its dense concentration of monuments, historical buildings, and churches, of exceptional historical and artistic significance. It is therefore apparent that advanced numerical analyses of the excavation-structure interaction are essential to properly model the problem. However, such analyses are not always applicable to all architectural pre-existences within the displacement field generated by tunnel excavation, making it necessary to resort to empirical methods calibrated on observations in green-field conditions. In this context, over the past three decades, and particularly in London, UK, several studies have examined the modification of the displacement and deformation field caused by the presence of the structure. Different authors, through extensive parametric analyses where the building stiffness, weight, and location, were varied, introduced design charts to improve the deformation predictions. In this paper, the results from these previous studies are compared with those from an extensive parametric study performed with 2D-equivalent Finite Element (FE) analyses, which have been conducted referring to the stretch line T2 of the new Line C of Rome underground. The FE models incorporate geometries derived from detailed analyses of historical Roman buildings, highlight the applicability of existing methods and their potential adjustments for Rome's unique architectural heritage.