3D rigid block micro-modelling of a full-scale unreinforced brick masonry building using mathematical programming

In this paper, we present a three-dimensional limit equilibrium analysis of an unreinforced brick masonry building. The structure under investigation is a one-room one-floor building that has been selected from a full-scale test carried out within the framework of a joint USA-Pakistan research project. The structural model of the building is an assemblage of rigid blocks, which interact through no-tension contact surfaces with Coulomb friction. A micro-modelling approach is adopted where each masonry unit is modelled as a rigid body. The underlying limit analysis formulation is based on the concave contact model, with contact forces located at the vertices of the interfaces. Iterative calculations are carried out to deal with the non-associative friction behaviour. The numerical analysis is carried out with the aid of a computer program that provides as output the failure load and the collapse mechanism. The comparison with experimental outcomes shows that the adopted formulation is capable to predict the actual behaviour of 3D masonry structures with a reasonable computational effort.