Author(s): Kengo Osada; Yoshihiko Shimizu; Robert Ettema

Linked Author(s): Yoshihiko Shimizu, Robert Ettema

Keywords: wood or ice accumulation; bridge waterways; bed scour; bridge forces; numerical and flume models

Abstract: Wood or ice-rubble accumulation at bridges may partially block bridge waterways, causing flow to assume a relatively strong downward component beneath the bridge, scouring the waterway’s alluvial bed beneath the bridge, especially around the bridge’s piers. Additionally, such accumulations exert forces against the bridge. The writers propose a numerical analysis model for simulating bed scour and loading caused by a cross-sectional blockage formed of woody debris or ice rubble accumulated against a bridge. The writers conducted flume experiments to obtain data on bed-scour shape, forces against a bridge deck, and water-surface profiles in a straight channel fitted with a blockage of fixed cross-section extent. The ability of the proposed numerical analysis model was validated by comparing predicted results with data from the experiments. Moreover, the writers developed a non-equilibrium sediment transport model to calculate local bed scours. These considerations enabled the writers to predict scour beneath a bridge, and the forces exerted against a bridge.

DOI: https://doi.org/10.3929/ethz-b-000675921

Year: 2024