【作者】 董丽红；

【导师】 梁书秀；

【作者基本信息】 大连理工大学 ， 港口海岸及近海工程， 2012， 硕士

【摘要】 海滩养护是近年来国内外备受推崇的海岸防护措施。我国十二五规划中对于海岸防护及岸线恢复工作更加重视,加强海滩养护相关理论和技术问题研究是进一步做好此项工作的关键。海滩养护剖面设计的合理性影响养护后岸滩与当地水动力环境的适应能力,从水动力角度分析影响海滩演变的设计因素是保证人工海滩稳定性的首要条件。本文首先回顾了近年来海滩养护在国内外的开展情况,介绍了海滩平衡剖面理论、海滩演变的数值与物理模型试验方面的研究进展。探讨了海滩养护中常见的稳定岸线形态及剖面形态设计方法。重点介绍了岬湾型岸线设计方法在海滩养护中的应用,并利用抛物线岸线拟合模型进行岬湾型岸线布置和岸线稳定性预测分析,包括现存海滩岸线的稳定性分析、人工建筑物修建对原有岸线的影响等。此外,依据Dean的平衡剖面理论对白沙湾海滩养护平衡剖面进行了初步设计。应用岸滩剖面演变模型,对不同海滩养护剖面设计方案下海滩稳定性进行数值模拟分析。利用剖面演变模型讨论补沙粒径、滩肩宽度、滩肩高程等因素对岸滩稳定性的影响,为合理选择海滩剖面设计参数提供依据。此外,进行了潜堤和护岸存在的海滩剖面演变数值实验,分析了不同堤顶高程、堤顶宽度和离岸距离的潜堤对岸滩剖面掩护作用的差异。利用岸线演变的一线模型,进行养护后新海滩岸线不同年限后岸线冲淤变化模拟,以基于岸线冲淤预测结果进行岸线布置方案的合理性评价。物理模型实验一方面能同时考虑泥沙的横向输移和纵向输移,另一方面弥补数值模型中对于波浪的折射、绕射、反射考虑的不足,因此,通过物理模型实验进一步分析岸滩剖面稳定性和岸线稳定性。首先进行实验室模型设计和布置,开展海滩物理模型验证性试验研究。通过实验中观察岸滩侵蚀部位和侵蚀强度,与现场观测结果对比,进行物理模型实验相似性验证,验证结果较好。在保证模型与原型相似的前提下,进行人工海滩补滩剖面和岸线稳定性研究,得到了不同重现期波浪作用下海滩剖面的侵蚀和恢复形态,以及不同重现期的波浪作用下的岸线的蚀退和淤长量,在此基础上分析了不同波浪条件对海滩横向剖面和岸线稳定性的影响,进行岸滩泥沙运移规律研究。更多还原

【Abstract】 Beach nourishment is a popular shore protection measure around the world in recent years. The Twelfth Five-year Plan for National Economic and Social Development stresses that more emphases should be put on shore protection and coastline restoration. It is suggested that more attention should be paid on the summarization and assessment of the theories and techniques on beach nourishment. The reasonableness of design profiles for beach nourishment determines the adaptability of nourished beach to the hydrodynamic conditions of the site. It is strongly emphasized that the influence of design factors to beach stability should be analyzed from hydrodynamic view.Firstly, the development of beach nourishment method is reviewed in and abroad China. Also, the state-of-the-art of Equilibrium beach profile model, numerical and physical experiment study in beach profile evolution are reviewed in this article. The models and design methods of shoreline and profile morphology for beach nourishment is discussed.The response of different design proposals is simulated under various wave and tide condition to assess the influence of different design factors, such as median diameter of filled sand, beach berm width, beach berm height to profile stability. Besides, the numerical study of profile evolution with sheltering submerged breakwaters and revetments is carried out to assess the sheltering effects of breakwaters with different top elevations, top width and distance from the shore. The nourished shoreline change after several years is simulated by means of one-line model which is widely used in shoreline evolution. Based on the evolution results, the rationality of shoreline layout is evaluated.Furthermore, the beach profile and shoreline stability is studied based on physical experiment. For one thing, both cross-shore and long shore sediment transport is included in physical model. For another thing, the wave refraction, diffraction, reflection are more close to real in physical model compared to numerical model study. The proven experiment is carried out to validate model similarity first. After this, artificial beach profile and shoreline stability experiment is carried out to study the response of nourished beach under different wave and water level conditions and the features of near shore sediment transport.更多还原