Implementation of a fiber Bragg grating sensor network for structural monitoring of a new stone bridge

Abstract

The implementation of a large sensing network based on fiber optic sensors for the structural health monitoring of a new five arch stone bridge with a total span of 60 m over Vizela River (Felgueiras, Portugal) is presented. In addition to the implemented instrumentation with conventional sensors, four different types of fiber Bragg grating based sensors were specially developed for measuring temperature, strain and displacement in several critical points of the structure. In total, 85 Bragg sensors were installed and more than 800 m of fiber cables were deployed along the bridge. The fiber optic sensing network installed on the bridge was entirely monitored by using a single measurement unit designed for collecting and archiving the signals from all the fiber Bragg grating sensors, and also to allow remote access to the important data through a standard GPRS connection.