3D Surveying for structural analysis applications

The plenty of works presented in last two years about the use of 3D models in the field of Cultural Heritage witness the great interest of surveyors, engineers, architects and archaeologists towards the laser scanning technique as an invaluable surveying mean for as-built documentation, digital archiving and restoration of important elements belonging to our historical and cultural heritage. Usually, the end products are represented by VR models (Vrml, Flash), suited to be shared among different user across the Internet, stunning movies (Avi, Mpeg, Divx), showing the 3D geometry of various objects, even phisically located in remote sites, embedded in a unique virtual environment, textured DSMs (Digital Surface Models) of both large and small size artistical pieces (e.g. churches, ancient buildings, statues, basrelieves, etc.) and orthophotos. Such wide variety of applications demonstrate that 3D models allow the user to retrieve different information contents from a unique digital representation of the reality, what is a topic not yet fully investigated. In the context of information retrivial from laser scanning data, this paper focuses on the use of TLS-based 3D models for structural analysis applications. To this aim an historical building, located in the city of Padua (Italy), was surveyed with the Leica HDS 3000 laser scanner for the generation of a complete 3D model of the object. Acquired point clouds were then registered in Polyworks and corresponding results were compared with the ones obtained by the application of Procustes Analysis algorithms, in order to verify the effectiveness of such registration method. Afterthat a few cross sections have been extracted from a building’s wall, presenting a few visible crackings, and employed for a FEM based structural analysis.