A Preliminary Structural Analysis of Typical Arches of Italian Gothic Churches

The preservation of the built heritage is a challenge for contemporary societies. Arches and vaults represent a widespread structural system; since they were conceived exclusively to withstand gravitational loads, they are exposed with seismic damage and therefore the structural safety of the entire buildings could be compromised. To preserve these structures and to properly design retrofitting interventions, a careful assessment of their capacity is required both under gravitational and seismic loading. However, the complexity of the construction systems and their different arrangements make it difficult to fully understand the mechanical behaviour of such important structural elements. The aim of this study is to evaluate the mechanical behaviour of three different types of Gothic arches (namely drop, equilateral and lancet) observed in typical Italian Gothic churches by means of a parametric study based on limit analyses with a kinematic approach. Therefore, an automatic procedure has been implemented to calculate the horizontal load multiplier sufficient to activate a four-hinge collapse mechanism in each arch subjected to both its own weight and horizontal static equivalent forces arising from a mass proportional distribution of acceleration. As expected, since in the adopted procedure the mechanical characteristics of the base materials have not been accounted for, the obtained outcomes have returned a significant dependence on the main geometrical features of the investigated vaulted structures. Furthermore, the preliminary parametric study carried out in this article could be easily extended by means of the developed automatic procedure, which is a very powerful tool also to analyze specific practical cases.