【作者】 陈少峰；

【导师】 尤学一；

【作者基本信息】 天津大学 ， 流体力学， 2012， 硕士

【摘要】 随着滨海城市的发展,围海造地的工程越来越多。工程项目改变了原始的岸线地貌,减少了海域面积,降低了水体交换能力。而且人工堤岸破坏了生态平衡,容易受到侵蚀。本文作为天津临港经济区人工堤岸生态修复与重建工程的一部分,建立了天津港海域和北港池的水动力、示踪剂扩散和拉格朗日粒子跟踪模型,就天津临港经济区北港池水体交换能力以及港池北堤岸的生态改造效果进行数值分析。本文的具体工作和结论如下:建立了EFDC水动力模型,综合考虑了风、潮流对北港池水交换能力的影响,并将港池按地形和功能区划分为10个子区域,比较了各个子区域之间的水交换能力的差别。计算结果表明,东南风加强了港池的平均水交换能力,而西北风减弱了港池的平均水交换能力。港池各个子区域间水交换能力差别明显,港池口端水体水交换能力最强,港池顶端最弱,港池中间段各区域也有差别,靠近北岸处,由于环流的存在,减弱了水体交换能力。采用不同的时间尺度作为港池水交换能力的评价指标,各个区域间的对比关系会发生改变。所以针对不同的区域特征,应该选择合适的时间尺度。设计三种不同坡度的堤岸,并计算堤岸毗邻水域的水体流动情况,综合考虑选取30o坡度为最终方案。计算堤岸上植被对水体流动的拖曳影响,及其所受的潮流力和波浪力。以水土交界处为原点,比较植被极端受力的力矩与植被须根能承受的最大力矩,可知文中选取的种植密度200株/m2,直径1.5cm,高度1.2m的大米草的存活需要在此区域添加三维网垫、混凝土框格等植被加固措施。更多还原

【Abstract】 There are more and more land reclamation projects along with the development of coastal cities. These projects have changed the original landscape of the coastline, reduced the area of the sea and the water exchange capacity. The artificial embankment has damaged the ecological equilibrium and easy to be eroded. This paper, as a part of Tianjin Lingang Economic Area artificial embankment ecology repair and reconstruction project, has built hydrodynamic model, tracer diffusion model and Lagrange particle tracking model for Tianjin harbor area and North pond, and also analyzed the water exchange capacity of the Tianjin Lingang Economic Area and the result of the ecological reconstruction of the North Harbor area. The main work and conclusion are as follows:EFDC hydrodynamic model was established with the consideration of the affection of the wind and the tidal wave on the North Harbor water exchange capacity. And then divided the harbor basin into 10 subareas according to the terrain and functional area, also compared the difference in the water exchange capacity among different subareas. The computation result indicated that the northwest wind has strengthened the water exchange capacity and the southeast wind has weakened this ability. The difference of the water exchange capacity between different subareas is very obvious. The harbor end has the best water exchange capacity and the top is the minimum. Using different time scales as the evaluation index of the water exchange capacity, the contrast relationships of different areas will change. So for different regional characteristics, we should choose a suitable time scale.Embankments of 3 different gradients were designed and the water circulation conditions of the embankment adjacent waters were also calculated. The 30°slope was decided to be the final solution after consideration. The effect of aquatic plants on the drag force of the water body and the tidal force and wave force were also took into consideration. After comparing of the extreme tidal force, the wave force and the maximum tensile force, the Cyperusirial of 200 plants per m2, 1.5cm diameter and 1.2m height need to add vegetation measures like 3D mesh pad and the concrete frame in order to survive.更多还原