SHM

Structural Health Monitoring (SHM) is an emerging tool for reliable structural assessments. Efficient monitoring programs may help characterize the progressive decay of structural performances, both in the short and in the long term, providing useful information for optimized maintenance and safety.
In recent years, wireless communication, low power computing, and sensing technology have allowed the application of Wireless Sensor Networks technology to face Structural Health Monitoring problems.
WEST Aquila developed a permanent structural health monitoring system for a monumental church, the Basilica S. Maria di Collemaggio at L’Aquila, Italy, strongly damaged by the 2009 earthquake. A partial collapse occurred in the transept area, caused the dome’s breakdown, and dramatically altered the whole structural characteristics. Benefits and critical issues related to wireless sensor networks technology were analyzed in the specific case of monumental building monitoring.
The system development, purposely designed to detect low-amplitude earthquake-induced vibrations, can be broadly divided into two distinct phases: the design and deployment of an accelerometric monitoring network (essentially designed to capture the global seismic response) and the design and deployment of a second network for wall inclination and crack width local measurement.
The system is specifically designed for seismic and dynamic response analysis based on acceleration, crack opening, and wall inclination measurements.
The modal signature extracted from the acceleration measurements has been compared with finite element models, furnishing valuable results to evaluate the temporary scaffolding structures’ effectiveness.