Displacement monitoring of a Long-Span Arch Railway Bridge using Digital Image Correlation (DIC)

There is an escalating demand for condition monitoring enhancement of transport infrastructures worldwide. Bridges are of vital importance in transportation infrastructure and need such monitoring. In this research, a non-contact vision-based technique called Digital Image Correlation (DIC) was used to calculate the bridge displacements. A high frame rate camera with 4K capability was used for raw data acquisition and simultaneous feature tracking. Also, a noise reduction filter is employed to make the measurements errors negligible. The displacement of the main span was calculated with an error of 0.08 pixel with 180 Frames Per Second (FPS) from a distance of about 200 meters. The obtained results by DIC were validated with those acquired from the verified FE model. It was concluded that the Digital Image Correlation method has acceptable proficiency and suitable precision for displacement measurement. Thus, it can be used as an alternative to traditional bridge displacement measurement instruments.