Evaluating a video gauge for deformation measurements of two UK long span bridges

Abstract

Bridge deformation measurements provide, through time and space derivatives, a rich set of information on cable stayed bridge (CSB) performance. Direct measurements of deformation of major components of CSBs i.e. deck, pylons, cables, are difficult due to problems with access and reference points. Compared to use of GPS and accelerometers which have more fundamental limitations, optical measurements offer many advantages such as multi-target tracking with limitations on resolution and accuracy in space and time being steadily eroded through developments in software capabilities. Hence we have revisited a research technology initially developed to monitor the Humber Bridge in 1990 and which now, in the form of a robust combination of hardware and Video Gauge software, provides a robust and effective solution for field monitoring.