Limit analysis of masonry domes: two case studies

This paper aims at defining the tools to interpret and quantify the mechanical behavior of masonry domes. The analysis is based on geometrical parameters only, while constitutive laws are not taken into account. No-tension assumption is made. Accordingly, membrane theory does not hold true and the dome splits into slices, so that it behaves like a set of arches with variable section, i.e., a thrusting behavior is considered for the dome. By limit analysis the collapse mechanisms are analyzed in relation to the load and shell geometry. This approach introduces an analytical method to predict the collapse and the associated horizontal limit thrust at the springing. This would suggest the possibility of adopting a geometrical safety factor Phi to define the condition acceptable for the equilibrium of the structure and the tool to lead the decisions when we must strengthened the dome.