Strain monitoring of composite steel girder bridge using distributed optical fibre sensor system

Abstract

An I type steel girder was assembled with a concrete upper plate and then placed on two roller supports. Four vertical load actuators were laid on the upper plate to add the vertical load. A single mode optical fiber was attached on the surface of the lower flange of a composite steel girder bridge with a length of 39 m. Longitudinal strain distribution of a composite steel girder bridge is monitored directly using optical fibre sensor system based on Brillouin frequency shift dependency of the strain applied on the optical fiber. Brillouin scattering signal is generated through the Brillouin optical correlation domain analysis at a selected location. Strain data were acquired at 195 points with the interval of 20 cm over the full range. From the strain data over the entire length of the composite steel girder bridge, the strain distribution shape was shown when the vertical load was added on the bridge. (C) 2011 Published by Elsevier Ltd. Selection and peer- review under responsibility of ICM11