Field Application of an Innovative Bridge Scour Monitoring System with Fiber Bragg Grating Sensors

Abstract

Bridge scour has attracted enormous attention because of its catastrophic influence on bridge safety. In order to measure and monitor scour depth variations including deposition process, a scour monitoring system was developed in the authors’ previous study. An instrument with fiber Bragg grating (FBG) sensors was designed together with a reliable sensor-protection measure, of which the performance has been tested in the laboratory. In the present paper, the proposed system was applied on a field bridge with a critical scour history. Two test piles were manufactured and each was assembled with six standard 0.9 m-long (3 ft-long) segments. The two test piles were then installed beside two foundation piles of the field bridge, respectively, for long-term monitoring. Up until now, the measured sensor responses have verified the functionality of the proposed system. The estimated scour depths based on the sensor data to date match qualitatively well with the actual scour depths observed on the bridge site, and the concept of the scour monitoring design has been confirmed.