Bridge monitoring by fiber optic deformation sensors: A case study

In the last few years, the real-time monitoring of civil infrastructures has become an essential tool for the safety inspection, the design and planning of maintenance. In this context, the implementation of optic fiber sensors within the structural elements is particularly useful in order to check strains and displacements and assess the structural safety level. In this paper, it is presented a methodology aimed at the control of the safety and serviceability level for a Prestressed Reinforced Concrete viaduct. The procedure is based on information acquired by an optic fibre monitoring system implemented during the construction of the bridge. The processing of the data provided by the sensors at different times of the execution (from the casting of the piers to the launching of the deck elements until the completion of the structure) allowed the appraisal of the strain variations related to the load increments and to the stress losses in the different phases and the comparison with the theoretical values. The advantages provided by this procedure in view of the maintenance programs makes it an effective tool for the periodic control of the structural safety of bridges.