EVALUATING THE STRUCTURAL INTEGRITY OF THE SAINT ANTONIO BARREL VAULT IN THE FORTRESS OF ALMEIDA BY COMBINING LASER SCANNER AND LIMIT ANALYSIS

Under the framework of the modern theory of restoration, this paper shows the experimental results obtained during the structural diagnosis of one of the most important master gates inside the military modern complex of Almeida in Portugal: the inner master gate of Saint Antonio. This master gate was conceived with the aim of supporting the siege of an early modern army, using to this end a masonry framework filled by a natural soil able to absorb the impacts. However, this infill is promoting the disaggregation of the masonry and thus the reduction of its bearing capacity. In order to evaluate the current and future structural behaviour, it is proposed a method able to combine the terrestrial laser scanner with the limit analysis for masonry constructions. The results obtained by this combination shows that the major barrel vault has, in its current conservation state, enough bearing capacity to support an agglomeration of people. However, it is recommended a material restitution in order to recover the contact are between masonry blocks as well as to recover the architectural interpretation of the element.