During winter, ice cover frequently forms on the water surface of rivers with vegetated channel beds in cold regions. The investigation of the impacts of both ice cover and channel bed vegetation on flow structures around bridge abutments is essential for engineers to gain a comprehensive understanding of the complex interactions occurring in such a situation. In the present study, the flow structure around a rectangular bridge abutment in the presence of vegetation under ice-covered conditions has been studied. Considering different vegetation densities by arranging vegetation elements in square and staggered configurations, this study incorporates the influence of ice covers with different roughness, namely smooth and rough ice cover. Key turbulence parameters, including turbulence intensity, Reynolds shear stress (RSS), and turbulent kinetic energy (TKE), are also examined based on laboratory experiments. Results show that the shape of velocity profiles for flow over a vegetated channel bed changes from an S-shaped curve under an open flow condition to a convex shape under ice-covered conditions. The effects of an ice cover and vegetation on the flow around the bridge abutment create unpredictable turbulence intensity patterns. Under a rough-covered flow condition, there appears a larger area with negative Reynolds shear stress (RSS) downstream of the abutment. Turbulent kinetic energy (TKE) under ice-covered conditions has substantially lower magnitudes than in open flow conditions.

中文翻译：

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冰层水流条件下河床植被存在下桥台周围紊流特征

冬季，寒冷地区河床植被茂盛的河流水面经常结冰。调查冰盖和河床植被对桥台周围流动结构的影响对于工程师全面了解在这种情况下发生的复杂相互作用至关重要。在本研究中，研究了冰覆盖条件下存在植被的矩形桥台周围的流动结构。考虑到不同的植被密度，通过将植被元素排列成方形和交错配置，本研究纳入了不同粗糙度冰盖（即光滑冰盖和粗糙冰盖）的影响。还根据实验室实验检查了关键湍流参数，包括湍流强度、雷诺剪切应力 (RSS) 和湍流动能 (TKE)。结果表明，植被河床上流的速度剖面形状从开放流条件下的 S 形曲线变为冰覆盖条件下的凸形曲线。冰盖和植被对桥台周围水流的影响会产生不可预测的湍流强度模式。在粗糙覆盖的流动条件下，桥台下游会出现较大的负雷诺剪应力 (RSS) 区域。冰覆盖条件下的湍流动能（TKE）比开放流动条件下的湍流动能（TKE）要低得多。