Symmetric Galerkin BEM for Non Linear Analysis of Historical Masonries

The preservation of the historical and monumental buildings, but also of the considerable heritage of old constructions made by traditional techniques, is one of the actual problems of the structural mechanics. The level of knowledge of their structural behavior in presence of external actions is made through calculus methods and simple procedures in order to allow a reading of the material suffering degree and as a consequence of the related safety. Unfortunately, often the masonry panels show openings located in an irregular way and cracks having small or big dimensions. In these cases the employment of strategies, as for example the identifying of the masonry piers and the transformation of the wall as a frame, prove to be inapplicable. Recently, a new method was introduced, called Boundary Element Method, which applied in its symmetric formulation, in virtue of some peculiarities, proves to be better usable in comparison with other analysis methods. In this paper an elastic analysis of walls, also in presence of geometrical nonlinearity consisting in the contact/detachment phenomenon among stone blocks. The wall having any shape and zone-wise variable physical characteristics is loaded in its plane. For these structures some interventions of structural strengthening have as aim to improve the wall behavior by reducing the stress concentration, so to have a better safety in comparison with its initial value.