Huerta Fernández, Santiago
The safety of masonry buttresses.
"Proceedings of the Institution of Civil Engineers. Engineering History and Heritage", v. 163
The vault is the main element of a majority of historical buildings. Masonry vaults exert an inclined thrust which must be resisted by a substantial mass of masonry: the buttress. The buttress system assures the safety of the whole construction. Old Master Builders were well aware of that and the traditional structural rules addressed mainly the problem of buttress design. Nowadays, the architect or engineer assessing the structural safety of a historical construction needs to estimate the safety of the buttress system with accuracy. This has been considered a simple topic, however, to estimate the safety of even a simple buttress is not an easy matter. The buttress may fracture under certain conditions with a substantial loss of stability. Besides, the buttress may show a certain leaning, it may be separated from the wall, etc. On the other hand, buttress systems are complex structures, a combination of walls and counterforts, flying buttresses, etc., made of different masonry. The matter cannot be handled in an abstract way. In the first part, an outline of the development of buttress design since ca. 1700 would serve to present the main approaches and to provide the historical context. In the second part, the state of the art of modern masonry buttress analysis is summarised, and a detailed discussion of the estimation of safety is made.