Masonry orthotropic vaults in historical construction: the herring bone pattern technology

The research would draw attention to the historical technology, especially to the masonry herring-bone pattern. The first examples could be found into the Roman Architecture. It was used for covering wide rooms using small clay brick elements. The herring-bone pattern and other geometrical and constructive devices had allowed to realise monumental constructions without wood framework. These monumental structures are still in service. The Authors aim is to develop an analytical model in order to investigate the structural behaviour of masonry barrel vaults built with herring-bone pattern. These structural elements are analysed in the field of shell theory and linear elastic behaviour of material; the masonry barrel vaults are modelled as bi-dimensional orthotropic elements. Starting with membrane components, the necessity to evaluate the effect of herring-bone pattern on the stresses configuration requires the introduction of flexural components in the equilibrium conditions. Formulated the static problem, the angle a of masonry configuration in herring-bone pattern is assumed as parametric element for the analysis. The range of the angle a will be the following: “head” and “flat” considering the brick along arch ring. The intermediate brick configurations are defined as herring-bone pattern and a assumes the values between 0 and p/2. The displacement field is evaluated for each configuration of masonry brickwork. Possible stress peaks, identified by the analytical model, are the start point for the definition of collapse mechanism which could modify the static behaviour of these masonry vaults.