涨落潮对海湾内新建人造沙滩稳定性的影响

为提高海湾内人造沙滩稳定性，以宁波西沪港北岸人造沙滩为研究对象，结合已有试验段人造沙滩退化过程，分析了沙源流失原因，并以此优化拟建段人造沙滩的位置，再通过波浪-泥沙物理模型试验，研究了不同强度波浪和潮位过程对拟建段人造沙滩稳定性的影响。结果表明：波浪和人造沙滩存在夹角时，沙滩前会存在明显的纵向沿岸输沙；人造沙滩建造后首年，平常浪作用1年对人造沙滩稳定性影响可能会大于单次台风浪对沙滩的作用；常浪作用下涨落潮引起的沙滩前沿水下沙坝发育过程不同，落潮水位过程波浪对沙滩的侵蚀大于涨潮水位过程；人造沙滩前落潮流和波生沿岸流方向一致，会加速沙滩侵蚀，当落潮流作用大于涨潮流，则会进一步导致沙滩严重退化。

The influence of flood and ebb tide on the stability of an artificial beach

To improve the stability of artificial beaches, an artificial beach in the Xihu Harbor, Ningbo, Zhejiang was studied. Combined with the degradation process of the test section of the artificial beach, the reasons of sand loss were analyzed considering which section of the proposed artificial beach had been optimized. The influence of different intensity waves and tidal processes on the stability of the proposed artificial beach were studied by wave-sediment physical modelling experiment. Results indicate that when there is an angle between waves and artificial beaches, there will be significant longitudinal coastal sediment transport in front of the beach. In the first year after the construction of artificial beaches, the impact of normal wave action on the stability of artificial beaches for one year may be greater than that of a single typhoon wave on the beach. The development of underwater sand bars at the beach front caused by flood and ebb tides under normal wave action is different, and the wave erosion on the beach during ebb tide water level is greater than that during flood tide. When the directions of the ebb tide and the wave generated coastal current in front of the artificial beach are the same, the erosion of the beach will accelerate. If the effect of the ebb tide is greater than the flood tide, the degradation of the beach will further deteriorate.