This study presents the dynamic behavior of bed material and local scour around a circular bridge pier under wave and current in a laboratory wave flume. Substantial bridge damages are considered to be occurred not only by the local scour but also by the dynamic instability of the bed material around the bridge pier under the persistent action by water waves. Observations were carried out on the local scour development under clear-water steady flow as well as under wave and current. Waves were generated from upstream side of bridge pier and from downstream side of bridge pier respectively. Observations were further carried out on the excessive pore-water pressure around a circular bridge pier. The results showed that the local scour depths found maximum in the downstream side of the pier for most of the cases under the coexistence of wave and current. The results also showed that the excessive pore-water pressure development decreased the effective stress of the bed material around the pier.

Akihiro Tsuda

Papers

Dynamic behavior of bed material and local scour around a circular bridge pier under wave and current