Investigation of the Effect of Plate on Reducing the Scour around Spindle-Shaped Bridge Pier

Objective:The problem of erosion is among the most significant topics in the field of river engineering. Every year, a large number of bridges around the world are destroyed, mainly due to the lack of hydraulic role in their design. Methods of controlling and reducing local scour include the use of roughness, collars, submerged plates and protective piles.Material and Methods: In the present study, the effect of submerged plates in controlling and reducing scour around the spindle-shaped pier has been investigated. In this research, plates with different angles of ۱۵, ۳۰ and ۴۵ degrees were used in single, two and three rows with different flow rates. Results and Discussion:The experimental results showed that by installing ۴۵- degree plates with ۱, ۲ and ۳ rows, we see ۲۳.۳, ۴۰.۵ and ۴۳.۸% reduction of scouring compared to the pier without plate. As the number of rows increases, the sediment displacement and accumulation in front of the bridge pier increases, which ultimately reduces scouring. By installing three rows of plates with angles of ۱۵, ۳۰ and ۴۵ degrees to the direction of flow, we see ۳۲.۸%, ۳۹.۷% and ۴۳.۸% reduction of scouring compared to the pier without a plate. Conclusion:By increasing the angle of the plates along the stream, their effective length increases and thus increases the sediment displacement by them, which results in more sediment being transferred to the front of the base and better scour control. Additionally, the simulation using the Flow-۳D mathematical model closely aligns with the physical model, yielding an RMSE of ۰.۰۳۹۲.

Keywords:

Spindle-shaped , bridge pier , Submerged Plate , Scour , mathematical model , Simulation