Structural Health Monitoring of Bridges using Digital Image Correlation: A Case Study

Abstract

The rapid development of the transportation section and continuous change in traffic volume, density, and loading patterns over the last few decades have increased the probability of a hazard and reduced the life of existing bridges. Structural Health Monitoring (SHM) is a process of implementing a damage detection and characterization strategy for engineering structures. This paper presents a review of various trends and technology adopted for SHM. However, it focuses on Digital Image Correlation (DIC), which is the latest technology for SHM. It is a non-contact non-destructive optical method of testing. Video Gauge is an instrument based on the DIC principle and can measure displacement, rotation, longitudinal strain, transverse strain, shear strain, dual average strain, Poisson’s ratio, and standard material test. The four-lane simply supported RCC T-girder bridge was tested using Video Gauge. Displacements were recorded at two locations with different cross-sections. These vertical displacements, when compared with analytical results, obtained by linear elastic grillage analysis, differ by 5% and 12.5% at defined points. For estimation of the safety of the limit state of strength, the analytical model was used to estimate maximum displacement, bending moment, and shear force for the worst load combination as per IRC: 6. From the results, it can be concluded that structural monitoring of bridges using the DIC technique can be employed successfully, and the bridge in this case study is safe for a limit state of strength.