Discontinuous Numerical Analysis of Masonry Vaults

In this article the behavior of buried vaults (arches, tunnels, bridges, etc.) is studied with Discontinuous Deformation analysis, a numerical method that allows for the discontinuity of the structure and bases its physics on contact and friction among blocks. Two vault geometries are studied, the first semicircular and the second similar to that of oval arches. The considered loads are the weight of the structure, those related with lateral filling, with embankment and with concentrated (through a short distribution) forces at the peak. These loads are transformed to side forces with standard contact algorithm (penalty, Coulomb friction) and to point forces applied to the center of gravity with simple formulae from Soil Mechanics.

The analysis results are compared with experimental ones taken from the literature with, for most cases, very good agreement given the uncertainties on the geometry and material properties and given the intrinsic quality dispersion of masonry structures. The comparison is done for collapse load as a function of the number of joints, safety coefficients and limit point loads, including several modes of failure. The geometry of collapse is also compared with that of the experiments, obtaining here very good agreement.

Key words: Masonry, discontinuous numerical methods, contact, friction, experimental, oval arch, vault, collapse, hinge, filling, embankment, point load.