Viability of optical tracking systems for monitoring deformations of a long span bridge
European Association for the Control of Structures
Characterisation of both dynamic and quasi-static deformations of suspension bridges is essential to manage their serviceability and to appreciate the internal forces due to the various live loads effects of wind, temperature and traffic. GPS is commonly used for the largest, most flexible structures but the limitations are not well understood and accelerometers cannot capture the extreme low frequency movements. Optical displacement tracking has potential to avoid all these errors but has different types of limitation that need to be evaluated and mitigated. In attempt to cross-validate optical tracking technology against GPS data, a commercial optical system the Imetrum ‘Video Gauge’ was used at Humber Bridge, after first initial experiments on a short span bridge to identify the most effective way to deploy it in the field for measurements at very long range. Some results are presented illustrating the character of the observed deformations and the limitations of the various forms of deformation monitoring instrumentation. In particular limitations of GPS were highlighted through comparison with Video Gauge and accelerometer data.
The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 330195. The authors would also like to acknowledge the support of the Bridge Design Group of Devon County Council, led by Kevin Dentith, and Humber Bridge Board.
Authors' manuscript. Paper presented at 6th European Conference on Structural Control (EACS 2016); July 11th - July 13th 2016 - Sheffield, England.
6th European Conference on Structural Control, 2016-07-11, 2016-07-13, Sheffield