Author(s): Zheng Chen; Dieter Rickenmann; Alexandre Badoux
Linked Author(s): Dieter Rickenmann
Keywords: Bedload transport high-frequency acoustic signals geophone flume experiments
Abstract: Bedload transport plays a crucial role in water-related hazard assessments and hydraulic engineering applications. However, accurately quantifying the bedload transport rates remains a significant challenge due to the large spatio-temporal variability of bedload rate, especially in steep gravel-bed streams. In this study, we performed controlled experiments in a flume facility, varying the grain size distribution, bed compactness, and initial water content of the bed material within the measurement section. Impact plate geophone systems were installed flush with the flume bed at both upstream and downstream locations to detect the changes in high-frequency vibration signals generated by transported bedload particles. Triaxial force sensors were embedded beneath the bed material to measure the basal impact forces triggered by the bedload particles. Flow velocities and depths of the moving bedload mass were recorded using a high-speed camera and laser sensors positioned above the geophone plates, respectively. The observed vibration signals were analyzed in terms of their spectrograms and power spectral density, with results presented as functions of flow depth and the power of the fluctuating forces. The findings of this study may provide some insights into the variability of the bedload transport processes in mountain streams.
Year: 2025