Minimum thrust of rounded cross vaults

In this paper the static behavior of the rounded cross vaults is analyzed. The study is based on the limit analysis approach developed for masonry structures and adopts a rigid no-tension constitutive model with no sliding. The kinematic theorem of the Limit Analysis with a compatible tridimensional mechanism is applied on these structures with the aim of the evaluation of the minimum thrust. In this way it was possible to build some abaci in which the ratio between the minimum thrust and the weight is plotted versus the geometrical characteristics of the vaults. At the end of the paper the proposed abaci are used to calculate the thrust of the main vault of the Diocletian Baths in Rome.