同安湾人工沙滩泥化问题的影响研究

摘要

Along with the rapid development of coastal tourism resources, providing more opportunities for tourists and local people to enjoy the beach, there have been an increasing number of coastal cities which are engaging in the construction of artificial beach. However, building a artificial beach on the muddy coast is a brand new project because' the hydrodynamic condition is relatively weak and scouring effect is deficient on mud beach. The fine sediments deposit on the artificial beach, which causes the beach mudding and affects the long-term administrative operation.Therefore, it is of great importance for the technology research and application to solve the problem of the artificial beach mudding. In Xiamen City the artificial beach will be built along the northwest beach of Tongan Bay.This paper gives a comprehensive analysis of the possibility and prospect of artificial beach mudding through the analysis of the investigation data based upon a field survey, the silt depositing and consolidating experiment, the silt motion experiment and analysis of the draft layout plan of the artificial beach. The research shows: (1) According to an analysis of the sediment, hydrodynamic environment and topography survey of 30 sections in Xiamen Bay, the beaches in the Xiamen Bay can be divided into three categories, i.e. sandy beach; muddy beach and sand-mud mixed beach. The wave is relatively weak in Tongan Bay due to the island's covering, and the annual wave height is only 0.3m～0.4m in average. The type of hydrodynamic environment is muddy beach. (2) When the intertidal zone below the water level, the water-absorption of sand has a remarkable accelerating effect on mud consolidation. If the mud deposit on the sandy beach, the mud density can reach 1.40g/cm3 within one hour. If the mud deposit on the bed below the water,the mud density will increase up to 1.40g/cm3 in 2 hours and stays steady. (3) According to wave channel experiment, by the calculation the critical shear velocity is 1.62cm/s when the mud density is 1.40g/cm3. In view of the relation between mudding depth and wave height, considering the average wave height is 0.3m～0.4m along the artificial beach, the mudding depth is 1.5m～2.0m by estimate along the artificial beach in Tongan Bay, equal to the mudding elevation is 4.0m～5.0m on theoretical position. (4) After the dredging project in Tongan Bay, the near-shore wave strengthens and the probability of sediment depositing reduces. The siltation intensity lessens along the artificial beach and the beach mudding elevation descends to 3.3m on theoretical position. The hydrodynamic environment is sand-mud mixed beach, which is advantageous for the artificial beach.

目录

英文文摘

声明

第一章 绪论

1.1研究背景及意义

1.2研究现状

1.2.1国外人工沙滩的研究进展

1.2.2国内人工沙滩的研究进展

1.2.3人工沙滩泥化现象的实例

1.3研究中存在的问题

1.4本文研究内容

1.4.1研究内容

1.4.2研究方法及技术路线

第二章 同安湾自然条件概况

2.1厦门同安湾地理环境

2.1.1厦门岛海域概况及围垦工程概况

2.1.2同安湾的地理环境

2.2同安湾的水文条件

2.2.1同安湾河流概况

2.2.2同安湾潮流特征

2.2.3厦门岛附近海域风况

2.2.4厦门湾波浪场特点

2.2.5同安湾波况分析

2.3同安湾泥沙条件和岸滩冲淤特点

2.3.1同安湾海域泥沙来源

2.3.2同安湾海域悬沙平面分布

2.3.3同安湾底质条件

2.3.4同安湾岸滩冲淤特点

第三章 现场勘测研究分析

3.1厦门湾岸滩现场勘测成果

3.1.1厦门湾海域波浪场分布特点

3.1.2现场勘察海域的岸滩特点

3.2厦门湾岸滩特征分析

3.2.1典型岸滩特征分析

3.2.2岸滩坡度与近岸波高相关性分析

3.3厦门湾泥化点研究分析

3.4本章小结

第四章 沙滩泥化机制试验研究

4.1沙滩上淤泥的沉降和固结机理试验研究

4.1.1试验方法及内容

4.1.2水下淤泥的沉降固结试验成果分析

4.1.3沙滩滩面上淤泥的沉降和固结特点

4.2波浪条件下淤泥扬动机制试验研究

4.2.1试验条件

4.2.2试验现象

4.2.3试验结果分析

4.3同安湾人工沙滩泥化点水深

4.4本章小结

第五章 人工沙滩平面布置方案设计

5.1平面布置的初步考虑

5.2人工沙滩输沙率计算

5.2.1沿岸输沙计算模式

5.2.2小风区波浪计算成果

5.2.3沿岸输沙率计算

5.3控制性合成波向角

5.4平面布置的优化

5.5本章小结

第六章 结论与展望

6.1结论

6.2展望

参考文献

致谢

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