Structural analysis of masonry elements in architecture

Abstract

The present article establishes the vantage required, in the author’s view, to analyze masonry structure performance. Until the nineteenth century, the entire history of architecture revolved around the various styles of such structures. The introduction of high toughness materials (cast iron and steel) with the industrial revolution and the adoption of rigidity as a parameter for compatible analysis laid the grounds, both in engineering training and professional practice, for analytical methods based on elastic rigidity (stress-strain curve). Masonry structures cannot be analyzed on such a basis: stone or brick elasticity is not readily measured. As a result, they are viewed as mere aggregates of solids working under compression only, pursuant to a statically indeterminate model of infinite order as a result of their likewise infinite number of articulated bonds. Moreover, like all structures they change with time, rendering any analytical model trivial unless account is taken of the actual conditions (fissures or cracking) prevailing in the structure at any given time of its service life. This paper modestly attempts to clarify the assumptions on which analysis is built, evaluating the basic principles of equilibrium, the only valid grounds for such analysis, and the conditions in which such equilibrium can be reached. Yesterday’s builders drew exclusively from experience to ensure equilibrium: for them structural safety meant the absence of collapse. Today vector algebra, observation with high precision instruments and a priori determination of the conditions that may lead to collapse underlie accurate and reliable conjecture about the performance of masonry structures that tangibly establishes safety levels at least as precisely as sophisticated methods of analysis.