船舶尾流冲刷作用下抛石基床块石稳定性计算方法研究

船舶尾流是导致重力式码头抛石基床冲刷破坏的重要因素之一,国内港口、海岸工程设计规范中未考虑船舶尾流作用对抛石基床块石稳定性的影响。文章通过总结、对比、分析国外船用螺旋桨射流流速分布研究成果,得到了螺旋桨射流流速分布规律,提出了船舶尾流冲刷作用下抛石基床块石稳定性计算方法,并利用该方法计算并分析了某重力式码头抛石基床块石的冲刷情况。计算结果表明:螺旋桨射流起始段和主体段的流速均可能对抛石基床块石产生冲刷影响,且主体段水流对块石稳定性影响更大,船用螺旋桨桨轴线距基床顶面高度2倍桨直径内的区域可作为船舶尾流冲刷影响区。

Study on stability calculation method of rubble bed stone under scouring effect of ship stern flow

Ship stern flow is one of the key factors that lead to scouring damage of gravity wharf＇s rubble bed.The effect of ship stern flow on rubble bed stability is not estimated in the code of harbor, coastal engineering design in China.Through summarizing,comparing and analyzing theresearch results on ship＇s propeller jet velocity distribution at home and abroad,the distribution law was obtained.A stability calculation method of rubble bed stone under the scouring effect of propeller jet was proposed and used to analyze the scouring effect on the rubble bed of a certain gravity type caisson.The calculation results show that the axial velocity in the zone of established flow has more significant scouring effect on rubble bed than the one in the zone of flow establishment, and the scouring effect could not be neglected if the propeller＇s rotation axis is not higher than the top surface of rubble bed by two times of propeller diameter.