Combining NDTs with digital photogrammetry survey and ambient vibration de-tection for diagnosis of pathologies in historic architectures toward conservative and compatible measures

Within the performance assessment of historic architectures, inspection, diagnostic and monitoring methods play a crucial role toward the comprehensive knowledge of both the effects deriving from potential pathologies and the factors affecting the actual behaviour of the system, with specific attention to local vulnerabilities and failure mechanisms. For the purpose, NDTs need to follow an integrated approach, where multidisciplinary methods, including laboratory testing, reality-based survey and detection of static and dynamic parameters, are applied. The paper is going to discuss the above-mentioned issues and present the case study of the Town Hall of Altamura (Ba), in South Italy, where a variety of correlated experimental techniques was carried out in order to assess causes and magnitude of a relevant cracking pattern, related to the facade rotation. Particularly, along with radar scanning, video-endoscopy and direct sampling, the investigation relied on some innovative technologies, including digital photogrammetry for survey of unknown underground structures and detection of ambient vibrations whose analysis allowed assessing not only the global structural safety but also the comfort level.