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.