Development of a Bridge Weigh-in-Motion System Based on Long-Gauge Fiber Bragg Grating Sensors

Abstract

Monitoring the weight of vehicles is essential for policymakers to maintain the condition of bridges. In the group of methods for weighing vehicles, bridge weigh-in-motion (B-WIM) systems are among the most prominent and have several advantages, such as convenience and no interruption to traffic. However, they still have one drawback in that, for most systems, a vehicle’s velocity and wheelbase need to be given in advance. Currently, this problem is usually solved by adding an axle detector, which leads to higher costs. Under such circumstances, this paper presents an alternative B-WIM system to measure a vehicle’s velocity, wheelbase, and axial and gross weight merely based on a single set of long-gauge fiber Bragg grating (FBG) sensors without additional devices. To test the effectiveness of this method under various conditions, a vehicle-bridge interaction (VBI) system simulation was performed based on the result of an indoor experiment. Also, an in situ test on an expressway bridge was performed to initially verify its feasibility. The results showed that this method can achieve its function with good accuracy under various conditions.