On the use of reinforcing layers to improve the static behaviour of arches or shells with single curvature

A linear elastic model constituted by two interacting concentric arches is developed. The sensitivity of the behaviour of the system to its mechanical and geometrical parameters is studied to individuate the fundamental ones. The analysis is extended to the nonlinear field by means of computational finite element models. Another objective of the research is to specifically analyse the interaction between the two arches when there is a large difference in stiffness. A practical case is represented by the retrofitting of a masonry vault with a single curvature (barrel vaults) with a reinforcing concrete layer that, in several cases, resulted in the detachment of some masonry blocks. Finally, on the basis of the results of the nonlinear analyses, which qualitatively confirmed the results of the linear ones, a slightly innovative approach to the use of the reinforcing layers is proposed.