Mechanics of masonry vaults: The equilibrium approach

The theory of masonry structures should take into account the essentials of the material "masonry": heterogeneity, good compressive strength, almost no resistance to tension, and a high friction coefficient. Besides, it should be appropriated to the usual structural type of old masonry buildings, i.e., vaulted structures with massive buttresses. Finally, it should consider that cracks are present in most masonry buildings and that these cracks may vary with time. From the end of the seventeenth century a "scientific" theory of vaulted masonry structures has been developed. Professor Heyman has incorporated this "old" theory of masonry structures within the broader frame of modern Limit Analysis. This scientific theory was preceded by another: the traditional "geometrical" theory of the old master builders. Both theories tried to solve the fundamental problem of structural design: to design safe structures, i.e., to understand what makes an structure safe (or unsafe). Both theories arrive to same conclusion: the safety of a masonry structure is a matter of geometry. A safe state of equilibrium is achieved through a correct geometry. Both historically and theoretically the "equilibrium approach" is the best approach to the analysis and design of masonry structures.