MONITORING OF HERITAGE STRUCTURES AND HISTORICAL MONUMENTS USING LONG-GAGE FIBER OPTIC INTERFEROMETRIC SENSORS - AN OVERVIEW

Heritage structures and historical monuments have a central cultural place in any society; old stone bridges, palaces, churches, cathedrals, monuments, etc., but also modem structures with very particular architectural or structural design represent an enormous civilizing value. Nevertheless, degradation processes generated by natural or human actions lead to deterioration, damaging or even loss of these inestimable treasures. Thus, regular maintenance and remedial works are unavoidable. The challenges, frequently met in practice, are related to the evaluation of structural health conditions and structural design. Aged and insufficiently known construction materials, as well as the lack of written documents explaining the design and construction of structural members, makes structural assessment difficult. In order to assess the structural health condition, including structural design issues, and also to help register and understand future developments, to performing structural health monitoring using an appropriate monitoring system is recommended. The long-gage fiber optic interferometric sensors have shown excellent performance on several heritage structures and historical monuments, including old church in Switzerland, the Royal palace in Italy, a heritage bridge in Russia, and a temple monument in Korea, just to name a few. A number of important parameters have been monitored allowing a sound assessment of the structural health condition and understanding of real structural behavior. Selected applications using long-gage fiber optic interferometric sensors are presented in this paper.