Safety assessment of ancient masonry towers

The results of structural analyses, carried out to assess the safety of a medieval masonry tower (the belltower of the Cathedral of Monza, Italy), are presented. The analyses were performed by means of a commercial finite element code with user-oriented interface. The interface was utilized to incorporate in the code a theoretical model, expressly developed to describe the creep behaviour of masonry up to failure, accounting for the evolution of damage. The reliability of this model was assessed in previous works, in which a masonry tower recently collapsed in Pavia (Italy) was analyzed and the predicted time to failure turned out to be close to the real one. The values of the parameters that define the model were obtained from experimental tests carried out on specimens taken from a part of the Cathedral contemporary to the tower. The numerical analyses point out the dangerousness of the tower conditions: indeed, a time to failure of about two centuries starting from today is predicted.