Square Cross Vaults on Spreading Supports

Abstract

This paper investigates the static of masonry square cross vaults on spreading supports through the limit analysis approach adopting a rigid no-tension constitutive model with no sliding. Compatible three-dimensional mechanisms are considered and a rigorous application of thrust line analysis is adopted, in order to evaluate vaulted structure capacity in terms of collapse displacement and associated thrust. For a better understanding of the behaviour of the square cross vault under large displacements, the related case of the elliptical arch on spreading supports is first analysed. The effect of the main geometric parameters and the different possible failure mechanisms are examined and discussed.