Abstract

The present paper aims at assessing the shape irregularities influence on the collapse conditions of masonry arches subjected to vertical point force. Surveys campaigns on cultural Heritage buildings often reveal masonry elements with irregular shapes. In order to accurately predict their actual behavior the presence of such features cannot be neglected. The reasons for these non-canonical shapes are manifold e.g. the evolution of degradation processes and the constructive laws. As a first analysis attempt, the geometrical uncertainties tied to the building work criteria are taken into account. A random parametric model is proposed to generate two-dimensional geometry of irregular polycentric arches. Monte Carlo simulations allows estimating the probabilistic density function of the collapse load multiplier evaluated by means of the implemented limit analysis method. The outcomes referred to the masonry arch with nominal geometry are compared to those obtained for the random polycentric arch, highlighting the extent of the load-bearing capacity reduction due to presence of such shape irregularities.