FROM THE CONTINUOS TO THE DISCRETE MODEL: A LASER SCANNING APPLICATION TO CONSERVATION PROJECTS

Abstract. This paper aims to demonstrate the usage of laser scanning (in particular through a methodology based on the integrated use of the software "FARO© Scene" and "GEXCEL JRC-3D Reconstructor") as a valid alternative to traditional surveying techniques, especially when finalized to the restoration and conservation repair of historical buildings. The need to recreate the complex and often irregular shapes of the ancient architecture, by acting quickly and also being accurate, as well as the subsequent implementation of FEM (Finite Element Method) for structural analysis, have made nowadays the laser scanning survey a very useful technique. The point cloud obtained by laser scanning can be a flexible tool for every need; not a finished product, but a huge database from which it is possible to extract different information at different times. The use of numerical methods in data processing allows wide opportunities of further investigations starting from the fitting equations. The numerical model lends by itself to the possibility of usage in many applications, such as modelization and structure analysis software. This paper presents the case study of the Church of the Assumption and Saint Michael the Archangel, located in Borgo di Terzo (Italy), a magnificent 18^th century's building that presented several structural problems like as the overturning of the façade, the cracking of part of the vaulted ceiling. The survey, carried out by laser scanner (FARO© Photon 120) allowed the reconstruction of the exact geometry of the church, offering the basis for performing structural analysis supported by a realistic model (and not an idealized regular one), useful also in the design of repair interventions.