Real-time health monitoring of historic buildings with wireless sensor networks

This paper describes the application of a wireless sensor network (WSN) in Torre Aquila, a 31 meter-tall medieval tower located in the city of Trento (Italy). Special attention was paid to monitoring and preservation of an artistic treasure: the fresco of the "Cycle of the Months" on the second floor. The various sensors installed include accelerometers, thermometers and strain gauges, arranged to record both structural response and external effects (road traffic vibration, temperature change), in order to real-time calibrate the structural model parameters and to identify any possible occurrence of abnormal situations. Strain sensors include prototypes of new Fiber Optic Sensors (FOS) in view of their long-term stability and durability. Based on the first 8 months of operation in assessing the stability of the tower, the wireless system is seen to be an effective tool thanks to its customized hardware and dedicated software. The whole system is reliable and energy efficient. The comparison between the acquired measurements and simulated numerical results shows good agreement.