On Site Surveying of a Historical Structure for Numerical Models Development and Seismic Retrofitting Design
The restoration of the building heritage in the Abruzzo Region (Italy) is related to a detailed analysis of the technical and constructive aspects in the minor architecture of its historic centers. This paper describes the studies carried out for the recovery and seismic improvement of an aggregate in the historical center of Celano (AQ). The theme offered the opportunity to experience the potential of new digital imaging techniques with the use of “FARO-Focus3D” laser scanners based on acquisition of “phase-shift” points and integrated with HDR photography. The laser scanner provided a virtual model of the structure while the HDR cameras provided information to characterize the individual constructive elements. The cognitive framework obtained with the new technology has been a valuable tool in designing retrofitting interventions. The 3D laser scanner relief detected the constructive vertical misalignments of the bearing walls and allowed to evaluate the degradation of the materials and the crack patterns. Complementarily, the surveys and the experimental tests have given the possibility to determine the mechanical and constructive characteristics of its masonry. Thanks to these studies, useful numerical “pre and post-intervention” models for the design phases were developed. The level of safety, starting from a minimum pre-intervention safety coefficient of 0.18%, reached a post-intervention coefficient of 0.61% (respect to a full safety one required for a new building) that has guaranteed the seismic practicability of that historical structure.