人工岛对河口行洪与冲淤影响的数值模拟研究

发布时间：2018-01-24 02:33

本文关键词： 人工岛河口数值模拟壅水分析冲淤分析　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着社会经济的快速发展，陆地的土地资源日渐枯竭，而地球上海洋面积约占地表面的71%，由此可见从海洋中开辟可用的陆地资源可以极大缓解陆地资源日渐枯竭所带来的压力。在海洋中开拓人类生存空间，开发具备多种功能的人工岛成为很多土地资源相对匮乏的地区和国家利用海洋资源的重要手段之一。然而人工岛的建设必然会对工程区河口或海湾附近的行洪与冲淤特性有一定影响。因此，，运用数值模拟的方法量化研究一定洪水条件下，工程区河口的行洪与冲淤特性对建设人工岛的响应具有重要意义。本文以汤河河口拟建人工岛为研究背景，利用平面二维数学模型模拟汤河河口水域在嵌入人工岛前、后的水动力及泥沙冲淤变化情况，进而总结人工岛对汤河河口行洪与冲淤的影响规律。具有主要研究成果如下：（1）建立了水动力及水动力-泥沙耦合数学模型，并利用人工岛附近的汤河河口区域里具有代表性的点和测站的实测资料对数学模型进行验证，验证结果吻合较好，说明所建立的数学模型的计算结果可以在一定程度上模拟和预测汤河河口水动力特性、泥沙输移及河口冲淤的变化趋势和规律，为进一步研究提供了计算工具。（2）利用所建立的水动力模型，模拟了在50年一遇设计洪水和50年一遇潮位叠加的情况下，汤河河口嵌入人工岛前后的水动力过程。通过对比分析建设人工岛前后的河道、河口及工程区附近的水位、流速及流向，来研究河道、河口及人工岛周边的壅水范围和壅水高度等变化情况，进而总结人工岛对汤河行洪的影响规律，并进一步分析了建岛前的清淤工程和灯塔对河口行洪的影响。（3）利用所建立的水动力-泥沙耦合数学模型，模拟了在50年一遇设计洪水条件下，汤河河口嵌入人工岛前后的次洪泥沙冲淤过程。通过分析对比修建人工岛前后的河道和工程区附近的冲淤量的变化情况，来研究河道、河口及人工岛周边的冲刷和淤积的情况，进而总结人工岛对汤河河口冲淤的影响规律，并进一步分析了人工岛东侧的灯塔对人工岛周边冲淤变化的影响。
[Abstract]:With the rapid development of society and economy, the land resources of the land are exhausted day by day, and the marine area on the earth covers about 71% of the surface. Thus it can be seen that opening up available land resources from the sea can greatly relieve the pressure brought by the gradual depletion of land resources and open up human living space in the sea. The development of artificial islands with multiple functions has become one of the important means for many regions and countries with relatively scarce land resources to utilize marine resources. However, the construction of artificial islands will inevitably affect flood discharge and flood discharge near estuaries or bays in the engineering area. The characteristics of scour and deposition have certain influence. Numerical simulation is used to quantitatively study the flood discharge and erosion and siltation characteristics of estuaries in the engineering area under certain flood conditions, which is of great significance to the response to the construction of artificial islands. In this paper, based on the proposed artificial island in the Tanghe estuary, the hydrodynamic and sediment scour and deposition changes in the Tanghe estuary are simulated by two-dimensional mathematical model before and after it is embedded into the artificial island. The effects of artificial islands on flood discharge and erosion and deposition in Tanghe estuary are summarized. The main research results are as follows: 1) the hydrodynamic and hydrodynamic-sediment coupling mathematical models are established, and the mathematical model is verified by the measured data of representative points and stations in the Tanghe estuary area near the artificial island. The results are in good agreement with each other, which indicates that the calculated results of the established mathematical model can simulate and predict the hydrodynamic characteristics, sediment transport and erosion and deposition trends of the Tanghe estuary to some extent. A computational tool is provided for further study. 2) the hydrodynamic model is used to simulate the case of design flood once in 50 years and tidal level superposition in 50 years. The hydrodynamic process of Tanghe estuary before and after embedding artificial island is studied by comparing and analyzing the water level, velocity and direction of river before and after the construction of artificial island and near the river mouth and engineering area. The variation of backwater range and backwater height around estuaries and artificial islands is summarized, and the influence of artificial islands on Tanghe flood discharge is summarized, and the influence of dredging engineering and lighthouse on estuarine flood discharge before the establishment of the island is further analyzed. 3) the hydrodynamic and sediment coupling mathematical model is used to simulate the condition of design flood once in 50 years. The secondary flood sediment scour and siltation process before and after the Tanghe estuary is embedded in artificial island. The river course is studied by analyzing and comparing the changes of the river course and the amount of scour and deposition near the engineering area before and after the artificial island is built. The influence of artificial island on the erosion and siltation of Tanghe estuary is summarized, and the influence of the lighthouse on the erosion and deposition around the artificial island is further analyzed.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV122;TV149

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