ABSTRACT
The near collapse-deformed configuration of a structure can be evaluated directly through mathematical programming, without the classical nonlinear incremental analysis. In this work, with the assumption of no elastic returns of the material, the theoretical deformed shaped at collapse of masonry bridges is directly defined using a variational principle, in the simplifying assumption of perfect elastoplastic behavior. The proposed approach is an extension of the well-known paper of Heyman. In the Heyman work, the final configuration of the structure that respect the restrain conditions is due to two contributions: the contribution of the elastic deformations of the structure portions between plastic-hinges and the contribution of the rotations concentrated in the plastic-hinge sections. In this work, the final configuration of the masonry bridges is evaluated considering the elastoplastic deformation of the structure obtained by the integration of the curvature that tends to infinity in the plastic-hinges sections and the rotations concentrate in the plastic-hinge sections
