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Laboratory Validation of a Piezoelectric Scour Monitoring Sensor

F. AZHARI, K. J. LOH, F. A. BOMBARDELLI

Abstract


Water current-induced vortices can scour sediments from around overwater bridge piers and abutments. If extended over a critical depth, bridge scour can cause significant damage and potentially even structural failure. Several promising scour depth sensing systems have been developed over the years, but they still suffer from issues including signal inaccuracy, installation difficulty, and high costs. This research focuses on evaluating the use of a prototype piezoelectric scour depth sensor, in which a poly(vinylidene fluoride) (PVDF) polymer strip forms the main sensing component. Extensive laboratory experiments were performed in which the sensors were driven into the soil surrounding a pier inside a flume simulating scour conditions. As the scour hole extended, the exposed length of each sensor changed, causing the flowinduced voltage signal to also vary. Scour depth at each sensor location was determined based on the fact that the dynamics of the voltage time history response is related to the exposed length of the piezoelectric sensor.

doi: 10.12783/SHM2015/360


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