摘要: |
由于对海岸景观和生态环境影响较小,渗透潜堤被广泛用于沙滩整治修复和侵蚀防护。在波浪水槽中开展物理模型实验,研究潜堤对沙滩剖面演化的影响。采用浪高仪阵列和激光扫描仪采集了水面高程变化和沙滩剖面高程,分析了波浪传播的相关水动力特征,包括波高沿程分布、透射系数、波浪能谱以及非线性指标(偏度和斜度),不同入射波浪和潜堤设置情况时沙滩剖面的变形特征,统计了沙滩侵蚀关键因子(岸线蚀退距离、单宽侵蚀量等),探讨了沙滩侵蚀与波浪条件、渗透潜堤特征参数之间关系,提出了沙滩侵蚀量与渗透潜堤无量纲特征参数的估算公式。研究表明:在堤顶破碎、大孔隙介质阻力和堤前反射综合作用下,入射至近岸沙滩的波浪能量降低,潜堤具有消浪和沙滩侵蚀防护作用;泥沙整体离岸输运,潜堤向岸侧淤积;对于实验考虑的工况,潜堤位置变化对沙滩防护效果的影响较小,堤顶宽度增加更利于消浪和滩面防护,潜堤对于较强的波浪表现出更好的沙滩防侵蚀效果。 |
关键词: 渗透潜堤 剖面演变 物理模型实验 水动力特征 |
DOI:10.11693/hyhz20211200307 |
分类号:P753 |
基金项目:国家自然科学基金资助项目,52071057号,51779022号,51809053号;国家环境保护海洋生态环境整治修复重点实验室开放基金,202108号。 |
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LABORATORY STUDY ON BEACH PROFILE EVOLUTION UNDER THE PROTECTION OF SUBMERGED POROUS BREAKWATER |
YI Feng1, FANG Ke-Zhao1, SUN Jia-Wen2, WANG Ping2, WU Hao1,2, YOU Zai-Jin3, LI Bi1
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1.State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China;2.National Marine Environmental Monitoring Center, Dalian 116023, China;3.Centre for Ports and Maritime Safety, Dalian Maritime University, Dalian 116026, China
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Abstract: |
The submerged porous breakwater is widely used to reduce coastal erosion due to its less interference to coastal landscape and ecological environment. To investigate the beach erosion evolution under the protection of submerged porous breakwater, a physical experiment was conducted in a wave flume. Wave gauges and laser scanner were used to record the elevations of water surface and beach. Wave hydrodynamics along the wave flume and the effect of different submerged breakwater configurations on beach erosion profile were analyzed in detail. A new equation between coastal erosion parameter ep and breakwater dimensionless parameter χ was proposed. Results show that submerged porous breakwater had a positive effect on wave dissipation and beach erosion. Additionally, the wave height decreased and the peak of fundamental frequency dropped sharply as waves broke atop the breakwater. Offshore transport of sediment on the beach was significant and the lee side of breakwater was mainly by siltation. The positioning of breakwater had a little influence on beach erosion. A wider breakwater could achieve better beach protection effect. |
Key words: submerged porous breakwater beach profile evolution physical model hydrodynamics |