Abstract Recent studies have shown that the presence of ice cover leads to an intensified local scour pattern in the vicinity of bridge piers. To investigate the local scour pattern in the vicinity of bridge pier under ice-covered flow condition comparing to that under open channel flow condition, it is essential to examine flow field around bridge piers under different flow conditions. In order to do so, after creation of smooth and rough ice covers, three-dimensional timeaveraged velocity components around four pairs of bridge piers were measured using an Acoustic Doppler velocimetry (ADV). The ADV measured velocity profiles describe the difference between the velocity distributions in the vicinity of bridge piers under different covered conditions. Experimental results show that the vertical velocity distribution which represents the strength of downfall velocity is the greatest under rough covered condition which leads to a greater scour depth. Besides, results show that the turbulent intensity increases with pier size regardless of flow cover, which implies that larger scour depth occurs around piers with larger diameter.

中文翻译：

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冰流条件下并排桥墩周围的速度剖面和湍流强度

摘要 最近的研究表明，冰盖的存在导致桥墩附近的局部冲刷模式加剧。为了研究冰覆盖流动条件下桥墩附近与明渠流动条件下桥墩附近的局部冲刷模式，必须检查不同流动条件下桥墩周围的流场。为此，在创建平滑和粗糙的冰盖后，使用声学多普勒测速仪 (ADV) 测量四对桥墩周围的三维时间平均速度分量。ADV 测得的速度剖面描述了不同覆盖条件下桥墩附近的速度分布之间的差异。实验结果表明，代表下落速度强度的垂直速度分布在粗糙覆盖条件下最大，导致冲刷深度更大。此外，结果表明，湍流强度随着桥墩尺寸的增加而增加，而与流量覆盖无关，这意味着较大直径的桥墩周围出现更大的冲刷深度。