Tie-rods are structural elements of crucial importance in ancient buildings to ensure structural integrity and safety, so the assessment of their effectiveness via an estimation of the axial load is of great importance. Dynamic techniques are often employed using accelerometers to measure the frequency response of the tie-rods. In this work, the frequency response of tie-rods is obtained with acoustic recording, thus introducing general-purpose microphones to potentially replace more expensive and complex sensors in this application. Two microphones were tested, one of known technical characteristics, and a second for which they were unknown. A procedure was designed to overcome the technical limitations of the latter, and two experimental campaigns were conducted to test the proposed method.

Protecting cultural heritage buildings poses significant research challenges. Effective damage prevention hinges on a thorough understanding of structural behavior and the continuous monitoring of its changes over time. Advanced visualization tools are essential to provide adequate awareness of the monitoring systems installed over the years while guaranteeing a quick, basic analysis of their data. This paper addresses a crucial gap in structural health monitoring (SHM), particularly in managing complex structures and systems, by responding to the growing need for tools that not only represent 3D models enriched with heterogeneous data and metadata but also facilitate detailed analysis of sensor recordings. In response to this challenge, it proposes the integration of a 3D informational model and an interactive web-based platform for monitoring data, creating a comprehensive management tool. Piazza del Duomo UNESCO Site in Pisa serves as an ideal test case due to its historical significance, structural complexity, and the wealth of monitoring data collected over time. With their interactive architecture, the two developed integrated visualization tools that could offer an effective solution for data management and visualization in other heritage contexts, particularly in cases where the monitoring system consists of numerous sensors and has evolved substantially over the years.

Monitoring of soil displacements is often crucial to the preservation of monumental buildings, since these structures are highly sensitive to differential settlements. Synthetic Aperture Radar (SAR) images from satellites appear as a tempting tool for monitoring, since they can be compared through interferometric techniques to track soil or building displacements in time. But interferometric SAR, which accuracy varies with image quality and type of displacement, has to be validated with on-site measurements. Exploiting the availability of open source data from the European Sentinel-1A and 1B satellites, this study aims at providing practical insight regarding the use of these remote sensing sources and method to monitor the well-being of monumental structures. Piazza del Duomo in Pisa (Italy) is selected as a case study, for its long historic record of on-site measurements and for the special role that settlements play in the behaviour of its monuments. The authors outline the advantages and limitations of the freely available SAR data from Sentinel satellites for the purpose of structural health monitoring of monumental structures, comparing it with information obtained through levelling.