Structural health monitoring applications with wireless sensors on an historical masonry building

In the last decades, the need for an effective seismic protection and vulnerability reduction of cultural heritage buildings and sites determined a growing interest in Structural Health Monitoring (SHM) as a knowledge-based assessment tool to quantify and reduce uncertainties regarding their structural performance. Monitoring can be successfully implemented in some cases as an alternative to interventions or to control the medium- and long-term effectiveness of already applied strengthening solutions. Traditional monitoring systems are composed of grids of sensors distributed along the structure to be monitored and connected to a central acquisition and processing unit through cables, and then post-processed in order to determine structure’s condition and assess a safety level. Recently, the use of wireless sensor networks (WSN) as an alternative base infrastructure for structural monitoring systems has been explored. A wireless sensor network is usually a more flexible solution (in facts, it does not require any cable deployment if the nodes are battery powered) with minor costs associated especially if the network is composed by low cost devices (e.g., MEMS sensors). Respect to a wired solution, new problems should however be considered: the synchronization between sensor nodes, the short transmission distance, the optimization of energy consumption and the selection of adequate low-cost sensors. In this framework, this work details the main results obtained in the context of the “Palazzo Comunale of Castelfidardo” monitoring project with WSN, with the aim to get an accurate numerical model that simulates the dynamic behaviour of the whole structure. A comparison between the structural responses obtained from the preliminary and an updated numerical model is proposed.