Static behaviour of in scale masonry vaults under imposed settlement of the supports

Abstract

The European architectural heritage is heavily characterized by the use of unreinforced masonry spatial structures, like vaults, which represent vulnerable elements in historical buildings. In recent years, the use of in-scale models to investigate the structural behaviour of vaults has largely increased in scientific research. In-scale models allow to overcome the difficulty of performing destructive tests on real structures and allow to investigate the complex three-dimensional failure mechanisms derived by different kinds of load, including the settlement of the supports. In this study, an experimental campaign is carried out on 1:5 in-scale models of barrel vaults with different brick laying techniques, to investigate their structural behaviour un-der settlement of the supports. Two brick patterns are tested: radial and vertical, with bed joints respectively orthogonal and parallel to the head arch plane. Models are built with cement blocks and low cohesion mortar, to simulate the typical historic masonry behaviour. Two tests for each brick arrangement are carried out on the models, which are tested under shear settlement, involving the movement of one abutment normally to the head arch plane. The acquisition process involves image and video recording, while a constant monitoring with the 3D-Digital Image Correlation (DIC) is performed to measure the three-dimensional deformations of the structures. The acquired information allowed to obtain, for each test, crack patterns, ultimate displacements and failure mechanisms. Comparison of the results highlights different behaviour between the vaults built with the two brick arrangements, in terms of different typical crack phenomena leading to different, local or global, failures. The results of the research could help practitioners dealing with interventions on architectural heritage to properly interpret the collapse mechanisms on existing vaults and could be used, in future work, in the validation of numerical models for brick vault analysis.