防城港拦门沙航道稳定因素的分析

THE ANALYSES OF STABILITY OF THE BAR CHANNEL OF FANGCHENG HARBOR

本文从泥沙、波浪和潮流三个方面分析了防城港拦门沙航道的稳定性问题。在上述三个因素中,潮流为主导因素。

The water depth of bar channel at the mouth of the Fangcheng Bay was only about 2 m before.Now it is -7.5m after the dredging. The annual accumulation of sediment is about tens of thousands m3. During summer season depositing and winter season erosion. South part is deposit area and north part is erosion area. Effect of Typhoon has little effect in blocking up the channel. The stability of bar channel is good.The interaction among sediments, wave and tide current is analysed based on the data of many years. The sediments are not abundant.H≥0.8 m of wave, frequency is low (p = 17.71%). The angle between channel and main wave direction is small, so the alongshore drift is weak and topographic change of bar is small. But the tidal influx is great in the Fangcheng bay. The flood (ebb) tide current velocity increases (decreases) along the bar channel, the velocity of ebb tidal current is higher than that of flood tidal current. The unsymmetry of tidal current is main factor for making the bar channel of Fangcheng harbor stable.