天津港人工沙滩环抱水域泥沙回淤研究

Study on siltation in encircled water area of artificial beach of Tianjin Port

为提高对环抱堤内水域的泥沙回淤状况的认识,以天津港东疆人工沙滩环抱堤内水域为实例,通过综合分析浑水现象调查、悬沙粒径时空分布、含沙量时空分布、余流等方面的资料得出了环抱堤内水域的泥沙来源,然后采用套图法计算了地形冲淤变化并分析了冲淤原因。结果表明,环抱堤内的浑水主要随涨潮水体自口门外流入;淤积区域的年均淤积厚度约为0.2 m,环流集中区所在的重淤积区的淤积厚度约为平均淤积厚度的2~4倍;口门约束形成的大流速和从口门直接入射的波浪,以及NE向小风区波浪的作用,造成口门—宾馆区沙滩水域出现深度约为0.2 m的冲刷带;环抱堤内水域的冲、淤分布与动力条件分布密切相关。

In order to increase the knowledge of the siltation in the water area encircled by dike,the materials were employed to analyze the source of sediment entering the encircled water area of artificial beach of Tianjin Port,including field observation of turbid water,the spatial and temporal distribution of particle and concentration of suspended sediment,residual current etc.And the variation of water depth was calculated with two maps measured in different time.The results indicate that the turbid water mainly comes from outside through the mouth of dikes with the flood current.The average depth of siltation is 0.2 m,and the circular current areas are more serious,where the siltation depth are approximately 2~4 times of average depth.The erosion zone with 0.2 m depth exists in the mouth area,which is caused by the high speed current under the restraining of mouth of dike,the incident wave and the wave in small wind area from NE.And hence,the distribution of siltation is closely related to hydrodynamic condition.