| 摘要: |
| 近年来风暴潮等海洋灾害日趋频发,沙质海岸侵蚀问题也愈发突出,沙滩稳定防护显得日益重要。为研究风暴浪作用下沙质岸滩稳定机制问题,设计了一系列的水槽试验,对风暴浪作用下沙质岸滩的稳定机制和演变过程进行了录像观察和研究分析。试验中采用图像处理技术,根据水和岸滩床面的像素值差异,对岸滩整体剖面进行实时动态提取;对比和分析了不同入射波高、波周期、水深、岸滩初始坡度以及波高连续变化下沙质岸滩演变过程。试验结果表明,岸滩稳定与岸滩初始坡度和沙坝的发育直接相关,而波参数主要影响岸滩扰动幅度和沙坝以及前滩侵蚀边界的位置变化。当入射波高连续变化时,沙坝迅速响应并向离岸迁移。岸滩变化幅值与入射波能流存在明显正相关关系,波能流越大对岸滩稳定性的危害越大。而水位升高会增强前滩向岸侵蚀风险。此外,在本试验尺度下,前滩以侵蚀为主。当岸滩初始坡度小于稳定坡度且波陡较小时,即Dean参数Ω'较小时,岸滩才发生明显的前滩淤积,这对于试验尺度下岸滩恢复工况研究至关重要。具体来说,当岸滩整体坡度为1:10且前滩坡度达到1:5~1:2.5时,岸滩稳定性最好,岸滩形态最接近最终平衡剖面,岸滩趋于稳定的时间最短。 |
| 关键词: 岸滩 水槽试验 初始坡度 波参数 稳定性 演变 图像处理 |
| DOI：10.11693/hyhz20220100026 |
| 分类号:P642 |
| 基金项目:NSFC-山东联合重点基金,U1806227号;国家自然科学基金项目,51739010号,52001292号。 |
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| LABORATORY SIMULATION ON SANDY BEACH STABILITY UNDER STORM WAVE |
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WANG Jun1, YOU Zai-Jin1, LIANG Bing-Chen2
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1.Centre for Ports and Maritime Safety, Dalian Maritime University, Dalian 116026, China;2.Shandong Provincial Key Laboratory of Ocean Engineering, Ocean University of China, Qingdao 266100, China
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| Abstract: |
| In recent years, marine disasters such as storm surges have become more and more frequent with increasing problem of sandy coast erosion. Therefore, the stability and protection of beach is an urgent task. To study the stability mechanism of sandy beach under storm wave action, a series of flume tests were designed to observe, study, and analyze the stability mechanism and evolution process of sandy beach under storm wave action. In the experiments, images were taken and processed, from which the overall profile of the beach were real-time extracted dynamically according to the difference in pixel value between the water and the beach bed. The evolution process of sandy beach under different incident wave height, wave period, water depth, initial slope, and continuous change of wave height were compared and analyzed. The test results show that the stability of beach was directly related to the initial slope of beach and the development of sand bar, and the wave parameters mainly affected the disturbance amplitude of beach and the position change of sand bar and front beach erosion boundary. When the incident wave height changed continuously, the sand bar responded quickly and migrated offshore. An obvious positive correlation was found between the variation scale of the beach and the incident wave energy flow. The greater the wave energy flow, the greater the harm to the stability of the beach. The rising water level could increase the risk of coastal erosion in the foreshore. In addition, under the scale of this experiment, the foreshore was dominated by erosion. When initial slope of the beach was below the stable slope and the wave steepness was small, that is, the Dean parameter Ω' is small, obvious foreshore deposition would occur on the beach. This is very important for the study of beach restoration conditions at the experimental scale. Specifically, when the overall slope of the beach is 1:10 and the slope of the foreshore reaches 1:5~1:2.5, the stability of the beach is the best, the shape of the beach is the closest to the final equilibrium profile, and the time for the beach to stabilize is the shortest. |
| Key words: sandy beach flume test initial slope wave parameters stability evolution image processing |
