Скачать или смотреть ‘Vibration-based monitoring of bridge scour’ - Kasun Kariyawasam

CSIC Research Talk
Thursday 27th August 2020

‘Vibration-based monitoring of bridge scour’
Kasun Kariyawasam

Abstract:
Historically, the most common cause of bridge failure has been “scour” – the gradual erosion of soil around bridge foundations due to rapid water flow. A reliable technique to monitor scour could potentially guide timely repair and, in turn, mitigate the risk of future scour-induced bridge failure. Currently, there are various, mostly underwater, techniques employed by bridge managers to monitor scour, ranging from diving inspections to autonomous underwater vehicles; however, none have gained wide acceptance. One technique that has caught our attention was vibration-based monitoring, which detects scour using changes in natural frequency derived from accelerometers above the water level on the bridge piers and deck. We carried out a field trial in an effort to study the potential to identify scour using the traditional parameter, natural frequencies of vibration. We unexpectedly found that two other little known indicators of scour, mode shapes and modal spectral densities, show far greater potential than natural frequency. We studied the sensitivity of these three indicators for different forms of scour in different types of bridges using a unique geotechnical centrifuge programme. This talk will present some of the exciting findings of this research programme and showcase how we can leverage the potential of vibration-based techniques to identify scour.

This research was supervised by Professor Campbell Middleton and advised by Dr James Talbot, Paul Fidler, Professor Gopal Madabhushi and Dr Stuart Haigh.