Strength of eccentrically compressed brickwork pillars: a theoretical and experimental analysis

The compressive strength of masonry is a relevant mechanical parameter playing a central role in the safety assessment of masonry structures. In spite of a large number of experimental data and of theoretical approaches, the failure of brickwork pillars and arches and its dependence on the strength and geometry of the constituents, on the masonry bond and on the loading conditions seems to be not clear. In this paper the cases of concentric and eccentric loading are analyzed both theoretically and experimentally. Aiming at a more detailed knowledge of the brickwork failure, a mechanical model for eccentrically compressed pillars has been formulated in order to relate the compressive strength to the brick unit dimensions. On the bases of prescribed statically admissible stress fields, the compressive strength is obtained from the Static Theorem of Limit Analysis. Besides, tests have been performed on brickwork prisms with different load eccentricities in order to reproduce the brickwork limit domains in the N-M plane. Comparisons between theoretical and experimental results are discussed