Abstract In the present study, the effect of collar on temporal scour depth variation at the base of a collar-protected circular pier was investigated. Experimental results revealed that a collar performs efficiently by reducing the rate of temporal scour depth variation around the pier. The efficiency of a collar, for different diameters and elevations, has been studied through flume experiments under clear-water scour condition. Analysis of obtained experimental results indicates that a collar performs efficiently and reduces maximum equilibrium scour at (undisturbed) bed-level. Further, the observations of the study revealed that the effectiveness of a collar increases with increase in collar diameter and decreases with the elevation of collar. Finally an empirical equation has been proposed to compute the time-dependent scour depth at the front of the collar -protected piers. The proposed equation has been validated and proven to be applicable to a wide range of variables under the effect of non-contraction flow. A sensitivity analysis has been done and it indicates that the collar diameter and its elevation are the most influencing parameters.

中文翻译：

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使用项圈减少码头周围的时间相关冲刷

摘要 在本研究中，研究了领圈对带领圈保护的圆形墩底部随时间冲刷深度变化的影响。实验结果表明，通过降低码头周围的时间冲刷深度变化率，项圈可以有效地发挥作用。通过清水冲刷条件下的水槽实验，研究了不同直径和高度的项圈的效率。对获得的实验结果的分析表明，领子有效地执行并减少（未受干扰的）床水平的最大平衡冲刷。此外，研究的观察结果表明，衣领的有效性随着衣领直径的增加而增加，并随着衣领的升高而降低。最后，提出了一个经验方程来计算领口保护墩前部随时间变化的冲刷深度。所提出的方程已被验证并证明适用于非收缩流影响下的各种变量。已经进行了敏感性分析，结果表明轴环直径及其高度是影响最大的参数。