吹填法填海造地悬沙减少施工工艺研究

发布时间：2018-04-22 20:48

本文选题：吹填法填海造地 + 悬沙减少　；参考：《鲁东大学》2017年硕士论文

【摘要】：填海造地在带动沿海经济快速发展的同时会产生一系列的环境问题,如:海岸线蚀退、水质恶化、海洋生物种类减少以及海洋灾害频繁发生。研究表明,施工过程中所产生的悬沙对当地水环境和海洋生物会产生不可逆转的影响。在填海造地扩大土地使用面积的同时应注意对海洋环境的保护。如何减少填海造地过程中的悬沙量,已为广大专家学者所关注。因此,针对吹填法填海造地悬沙减少施工工艺的研究对于指导实际工程建设和保护海洋环境具有较为重要的现实意义。目前关于吹填法填海造地施工过程中如何减少悬沙产生的研究仅局限于施工过程的某个环节,不能贯穿整个过程;此外,对于施工过程中悬沙扩散的研究,常采用平面二维扩散方程计算出其包络面积,不能直观的展现悬沙扩散的动态变化。本文重点分析了填海造地过程中不同环节悬沙产生的影响因素,讨论了各个环节中减少悬沙的方法,并通过数值模拟对不同工况下的悬沙浓度和扩散范围进行比较,定量分析不同影响因素下的结果差异。主要内容如下:1、吹填施工过程中悬沙产生的主要影响因素分析。通过分析悬沙产生的机理,重点关注施工过程中的基槽开挖、围堰设置与拆除、吹填及自然因素对悬沙产生的影响。2、悬沙减少施工工艺优化研究。在上述第一条内容基础上,针对悬沙产生的不同环节,提出了相应的优化措施。包括护岸抛填施工中抛石位置选择、基槽开挖阶段施工机械选择、围堰的施工顺序和天气选择、吹填物料的选择、排水口、溢流口位置的合理布置、龙口合拢时机的选择等。3、数值模型建立与设计工况的模拟。以龙口湾海域为研究对象,应用MIKE21水动力模块(HD)耦合对流扩散模块(TR),采用动量方程、质量方程和对流扩散方程为控制方程,利用Mesh Generator生成三角形非结构化网格,建立求解研究海域悬沙扩散输运模型。应用上述模型,计算当地潮流场的运移动态,并分析悬沙扩散浓度包络图,定量分析不同源强、吹填物料、作业位置下悬沙浓度和扩散范围的差异。吹填法填海造地悬沙产生主要集中在护岸、基槽开挖、围堰的建立与拆除以及吹填阶段,针对不同施工环节提出相应的优化措施,可有效减少悬沙产生。源强、吹填物料和作业位置对悬沙浓度和扩散范围有显著影响。本文结论可为实际工程建设提供一定的理论依据。
[Abstract]:Reclamation will bring about a series of environmental problems, such as coastal erosion and retreat, deterioration of water quality, reduction of marine species and frequent occurrence of marine disasters. The results show that the suspended sediment produced during construction has an irreversible effect on the local water environment and marine life. Attention should be paid to the protection of marine environment while reclaiming land to expand land use area. How to reduce the amount of suspended sediment in the process of reclamation has been concerned by experts and scholars. Therefore, it is of great practical significance for practical engineering construction and marine environment protection to study the construction technology of reducing suspended sediment by reclamation. At present, the research on how to reduce the formation of suspended sediment in the process of reclamation by blowing method is limited to one part of the construction process and cannot run through the whole process. In addition, the research on the diffusion of suspended sediment during the construction process, The plane two-dimensional diffusion equation is often used to calculate the envelope area, which can not show the dynamic change of suspended sediment diffusion directly. In this paper, the influence factors of suspended sediment in different links during reclamation are analyzed, the methods of reducing suspended sediment in each link are discussed, and the concentration and diffusion range of suspended sediment under different conditions are compared by numerical simulation. Quantitative analysis of the results of different factors. The main contents are as follows: 1. Analysis of the main factors influencing the formation of suspended sediment in the process of filling construction. Based on the analysis of the mechanism of suspended sediment formation, emphasis is placed on the optimization of construction technology for reducing suspended sediment by excavation of foundation groove, setting and dismantling of cofferdam, filling and natural factors. On the basis of the first article above, the corresponding optimization measures are put forward for the different links of suspended sediment production. Including the choice of riprap position in the construction of bank revetment, the selection of construction machinery in the excavation stage of foundation groove, the construction sequence and weather selection of cofferdam, the selection of filling materials, the reasonable arrangement of the location of drainage port and overflow port, Longkou closing time selection. 3, numerical model establishment and design conditions simulation. Taking Longkou Bay as the research object, using MIKE21 hydrodynamic module (HDD) coupled convection-diffusion module, using momentum equation, mass equation and convection-diffusion equation as control equations, Mesh Generator is used to generate triangular unstructured meshes. A model for the diffusion and transport of suspended sediment in the studied sea area is established. By using the above model, the migration dynamics of the local tidal current field are calculated, and the envelope diagram of suspended sediment diffusion concentration is analyzed to quantitatively analyze the difference between the suspended sediment concentration and the diffusion range under the condition of the different homology, the filling material and the operating position. The formation of suspended sediment is mainly concentrated in bank revetment, foundation trench excavation, cofferdam construction and demolition, and the construction and demolition of cofferdam, and the corresponding optimization measures are put forward in view of different construction links, which can effectively reduce the formation of suspended sediment. The source strength, filling material and working position have significant influence on suspended sediment concentration and diffusion range. The conclusion of this paper can provide certain theoretical basis for practical engineering construction.
【学位授予单位】：鲁东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P756.8

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