Assessment of structural damage and evolution in time in historical constructions using numerical models: the case of the church of Saint Bassiano in Pizzighettone, Cremona

This paper investigates the capability of advanced numerical modelling techniques to simulate experimental observations as damage or deformations in complex masonry structures. The case of the church of St. Bassiano in Pizzighettone, Cremona Italy is chosen. A multidisciplinary research was set up to collect data as geometric survey with Lidar technology, measurement of axial force in the iron tie rods of the nave, and a monitoring system for crack widths. The data was used as an input to develop and validate a finite element model to study the structural damage and the evolution of the building in time. The finite element model features a three-dimensional geometry, which is created in part automatically, taking advantage of a parametric model for ribbed masonry vaults, proposed recently by the authors. The FE model results in close adherence with the real building structure, due to the accuracy of the collected data. The simulation model features a continuum plastic damage model to take into consideration the masonry constitutive behaviour. The results show how the system response is closely related to the structural evolution in time, associated with the dismantling of the chapels on the south side and the addition of the iron tie rods in the nave. The numerical simulations highlight also the important effect of the soil settlements in the present crack pattern. The information obtained using this approach will allow to understand the active mechanisms in the building and to optimise the technical interventions in critical parts of the structure.