Vision-Based Displacement Measurement of Pedestrian Suspension Bridges

The number of pedestrian suspension bridges in South Korea increased from 188 to 208 between 2020 and 2021, with a corresponding increase in the number of visitors. However, these bridges are susceptible to structural issues due to natural factors and their continual usage, necessitating structural health monitoring (SHM) to prevent accidents. SHM requires data on the structure's vibration, deflection, and deformation. This study proposes a system utilizing targets for vision-based dynamic behavior measurement of pedestrian suspension bridges through image processing and applying these data to SHM. The proposed method demonstrated a deviation of only 1.3150 mm when compared to the direct measurement of the bridge's dynamic behavior and yielded almost identical mode shape results. The proposed approach can be effectively employed to inspect and maintain pedestrian suspension bridges.