Traditional vs innovative structural health monitoring of monumental structures: A case study (pages 430–449)

摘要

This work reports an experimental comparison between two measurement techniques of crack openings: antraditional method based on a mechanical device and the OTTO system based on fiber optic sensors andndeveloped by CELM. The main characteristics of both methods are presented, with their main advantages,ndrawbacks, and peculiarities. The testing campaign conducted on a historical church erected in the first halfnof the eighteenth century is then described in detail. Cracks evaluation has a key role in the safetynassessment of a monumental building and it is the base for a proper restoration design and interventionnplan. The measurements monthly collected using the two described methods are compared and thenperformances of the two monitoring systems are discussed from both technical and economical points ofnview. Of particular interest are the unique characteristics of fiber Bragg gratings (FBG) sensors includingntheir noninvasiveness and their extremely high precision in both displacement and time resolutions. Thesenfeatures make FBG sensors the ideal candidates for long term or not invasive monitoring. On the othernhand, mechanical measurements remain the best candidates for initial or sporadic measurements.nCopyright r 2010 John Wiley & Sons, Ltd.