ABSTRACT
In this chapter, the authors describe the collapse behavior of cross vaults, damaged or undamaged, under horizontal static action. In the present modelling, masonry is discretized as a system of interacting rigid blocks in no-tension and frictional contact. As widely acknowledged, the problem of evaluating the collapse load and the collapse mechanism of Lagrangian systems of elements interacting through no-tension and frictional contact surfaces corresponds to the Limit Analysis of discretised rigid perfectly-plastic systems with non-associative flow rules. Roman masonry should be modeled properly as a continuum material with some resistance in tension; it could hardly be represented as assemblies of blocks in no tension and frictional interfaces. In Roman Baths, the Romans employed groin vaults of great dimension. In the aim of structural conservation of ancient wide span vaulted halls, simple tools of analysis are lacking, despite the many sophisticated computational methods available; due to geometrical and material complexity the theme is not commonly faced in technical literature.
