La tecnologia laser scanning per la valutazione statica delle strutture storiche

Abstract

In recent years, laser scanning technique has aroused huge interest in the field of structural analysis of historical built heritage aimed at the evaluation of different static stress states and the assessment of health conditions. Nowadays it is possible to generate and manage multi-scale and simplified 3D and 2D structural models featured by different levels of detail, on which static assessment can be applied. The Geomatics group of the Politecnico di Torino, in cooperation with the Structural Engineering group, has started a series of experiences and studies oriented to outline "good practices” for the models generation of different historical structures, from ancient stone-walls, up to wooden beams, thin vaults and reinforced concrete structures.
This paper shows some results, issues and considerations of such experiences: an in-depth analysis about the generation of adequate 3D models from point clouds and their geometrical generalization is carried out, which comes with the selection of the best strategies and algorithms for the automation of editing.
The selected case studies are quite different regarding the period in which they were built and, therefore, regarding their building systems. The aim is to highlight tools already available for the automatic and semiautomatic
geometrical entities recognition and features extraction which are necessary to develop geometrical models useful for Finite Element Method (FEM). The case studies consist in: the large masonry blocks laid almost dry of the ancient suburban bath of Hierapolis (TK); the thin wooden vault and wooden
timbers roof of the large sloping Baroque roofs, both belonging to the seventeenth century Castle of Valentino in Turin; the latest is the reinforced concrete vault of the Paraboloid of Casale Monferrato (AL).