Temporal Variations of Scour Depth in Non-Uniform Twin Piers

Document Type : Research Paper

Authors

• seyed mohammad Ravanfar ¹
• Reza Mohammadpour Ghalati ²
• Touraj Sabzevari ³

¹ Islamic Azad University, Estehban branch

² Department of civil engineering, Estahban Branch, Islamic Azad University, Estahban, Iran

³ Department of Civil Engineering, Estahban Branch, Islamic Azad University, Estahban, Iran

10.30495/wej.2025.32090.2392

Abstract

Local scour around piers poses a significant challenge for hydraulic structures. Typically, due to geotechnical and economic constraints, most bridge piers are built on a foundation featuring two piers (referred to as non-uniform twin piers). Understanding the temporal evolution of scour around these structures is crucial. The novelty of this study lies in investigating the temporal variation of scour around non-uniform twin piers and determining the scour depth. All experiments were conducted under clear water conditions on non-uniform twin pairs with three different foundation distances (XP/D) and levels (ZF/D). The findings indicate that when the foundation is positioned beneath the scour hole, the maximum scour depth equals the foundation level and remains constant over time. Conversely, if the foundation is placed within the scour hole, the scour depth remains stable for a specific period (delay time), which is influenced by the foundation dimensions and the distance between the piers. Additionally, it is observed that the minimum scour depth occurs within the range of -1 < ZF/D < 0. In light of this study, it can be concluded that the delay time for non-uniform twin piers is shorter than that for non-uniform abutments and piers.

Keywords

• آبشستگی
• تراز پی
• پایه مرکب
• گروه پایه ها
• زمان تاخیر

Main Subjects

• subject

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