共查询到19条相似文献，搜索用时 812 毫秒
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基于非静压数值计算模型,本文系统研究了聚焦波作用下透水潜堤的消波特性,通过设置合理的计算工况,详细分析了波高、堤顶水深、谱峰周期、孔隙率以及堤顶宽度5种因素对透水潜堤消波特性的影响。与此同时,本文将透水潜堤的计算结果同不透水潜堤的计算结果进行了对比分析。计算结果表明:透水潜堤对聚焦波的消减作用要强于不透水潜堤,从而说明,透水潜堤能更有效地降低畸形波对海岸基础设施的影响;波高和堤顶水深是影响潜堤消波特性的重要因素,随入射波高增加、堤顶水深减小,透水潜堤对波浪的消减作用逐渐增强。透水潜堤对长周期波浪的消波效果较差。在本文考虑的孔隙率范围内,孔隙率越大,透水潜堤消波效果越好;当孔隙率为0.4,堤顶宽度为0.612 5 m时,透水潜堤可消减54%的入射波能,比不透水潜堤对入射波能的消减增加36.1%。本文研究结果可为进一步认识透水潜堤的消波特性和海岸防护工程设计提供相应的参考。 相似文献
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柔性水囊潜堤由橡胶制成,内部充水,具有结构简单、造价低廉等优点,能较好满足人工岛、跨海桥梁、海洋平台等基础设施建设工程对简单便携、拆装方便的临时防波堤的需求。为了探究柔性水囊潜堤的消波特性,在溃坝水槽内开展溃坝波与半圆柱形柔性水囊潜堤相互作用的试验研究,重点探究柔性水囊潜堤与溃坝波相互作用过程中水位变化特性,并与半圆柱刚性潜堤的性能进行比较;同时分析柔性水囊潜堤内部初始水压和浸没深度等参数对其消波性能的影响。结果表明：柔性水囊潜堤能够用作临时防波堤来衰减波浪;与半圆柱刚性潜堤相比,柔性水囊潜堤在降低溃坝波无量纲最大水位、提高消波性能方面更具优势;内部初始水压是影响柔性水囊潜堤消波性能的重要因素,适当降低内部初始水压,有利于增强柔性潜堤的变形程度,进而增加波能耗散,可获得更好的消波效果;而增加浸没深度即潜深,会使得柔性水囊潜堤对溃坝波的影响程度降低,消波效果减弱。 相似文献
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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。 相似文献
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人工沙滩与潜堤结合是沙质岸滩软硬防护相结合的防护技术。本文在利用实验室物模试验结果对XBeach水沙运动数值模型进行了有效性检验的基础上,应用该模型对月亮湾沙滩修复工程人工沙滩与潜堤相结合的岸滩防护技术,进行岸滩剖面演变数值分析。通过对风暴海况波浪作用下,该工程有、无潜堤以及潜堤不同位置和不同高度的5个工况数值计算结果分析,得出潜堤的设置,可以使沙滩侵蚀有不同程度的减轻或范围缩小,对人工沙滩防护具有良好的效果;潜堤的位置和高度影响其对沙质岸滩防护效果,潜堤的位置后移和高度升高都会使波浪的冲泄区下移,从而减少对上部沙滩的侵蚀,对人工沙滩的防护效果更好。 相似文献
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无口门式潜堤蓄泄系统中水流属于非恒定流,其蓄泄问题以及堤后坝田内的水位问题关系到潜堤的保滩促淤效果以及堤身的结构稳定性,外海潮位的交替变化对潜堤蓄泄系统的非恒定流调节影响较大,其蓄泄特征较复杂,文中以水量平衡原理为基础,结合外海潮位特性,建立不同情况下坝田内水位变化的解析方法,通过对工程实例计算验证,分析不同的潜堤方案对坝田内水位的影响,结果表明,该方法可以合理地模拟潜堤后坝田内的水位变化过程. 相似文献
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潜堤研究中的几个问题 总被引：1，自引：0，他引：1
本文综述现有国内外一些潜堤方面的研究成果,对潜堤设计中的几个问题,如合理的断面型式;合理的堤顶相对标高α/H(α——潜堤堤顶水深,H——潜堤堤前原始波高);消波性能(即波高传递率)n=H_1/H(H_1——潜堤堤后波高,)及潜堤块体稳定重量 W_z 等进行了分析比较并对上述几个问题进行了探讨。 相似文献
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潜堤结构型式及其透射系数研究 总被引：6，自引：2，他引：6
针对胜利油田某保滩促淤工程，进行了多种方案不同潜堤结构型式的优选，比较了其中四种结构型式，并对这四种结构型式的潜堤分别进行了波浪水槽试验，测试其透射系数，在此基础上，给出了计算潜堤透射系数的经验公式，为工程设计提供依据。 相似文献
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桩式离岸堤保滩促淤工程消浪效果试验研究 总被引：9，自引：0，他引：9
在上海奉贤南北港保滩促淤工程中，采用了一种新型结构型式－桩式离岸堤，并通过物理模式试验进行了桩式离岸堤消浪效果研究。针对离岸堤通常建于近岸水区破波带的特点，重点研究水深，堤高以及堤身结构对波浪衰减的影响，同时对桩式离岸堤堤后水域的波浪底流速 分析探讨。研究结果表明，桩式离岸堤不仅具有良好的消浪效果。而且可在较大范围内改变波态，即由引起水体剧烈紊动的破波转变为浅水推进波，从而有效地改善海滩上的动力条件，促进海滩免受侵蚀，是一种具有广泛应用前景和新型保滩促淤结构。 相似文献
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The unsteady, two-dimensional Navier–Stokes equations and the exact free surface boundary conditions were solved to study the interaction of a solitary wave and a submerged dike. A piston-type wavemaker was set up in the computational domain to produce the incident solitary waves. The incident wave and the associated boundary layer flow in a wave tank with a flat bed were compared with the analytical solutions to verify the accuracy of this numerical scheme. Effects of the incident wave height and the size of the dike on the wave transformation, the flow fields, and the drag forces on the dike were discussed. Our numerical results showed that even though the induced local shear stress on the top surface of the dike is large at some particular locations, the resultant pressure drag is much larger than the friction drag. The primary vortex generated at the lee side of the dike and the secondary vortex at the right toe of the dike may scour the bottom and cause a severe problem for the dike. 相似文献
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The Nampo dike, which is located at the west coast of Korea, was destroyed by wave overtopping during the storms on 30 August and 17 September in 1959. In this paper, is performed the probabilistic assessment of wave overtopping of Nampo dike by use of Owen model, Van der Meer ＆ Janssen model and Hedges ＆ Reis model for wave overtopping of seawall. Based on the available tidal and wave data for storm surges in 1989, the risk assessment of wave overtopping of the Nampo dike has been carried out by both Level Ⅱ and Level Ⅲ reliability methods. The calculated resuhs show the general agreement of failure probability between the two methods. By utilizing the rehabilitated cross section of Nampo dike, the failure probability of wave overtopping for the Nampo dike after rehabilitation will be rapidly reduced to that of initial design at crest level of 9.0 m with the improved slope from 1 ： 2 to 1 ： 4 at seaside. Since the sea level may only rise 1.0 m in the next few decades, the failure probability of Nampo dike will be still in the safe range. 相似文献
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Zhou Jiabao Zhang Jiachang Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing 《中国海洋工程》1992,(1)
-The effect of wave group on wave run-up on a slope dike is mainly discussed in this paper. Two simulating methods of wave group and their applications in laboratory are introduced. Synthesizing the research results of wave run-up on a slope dike, the effect of wave group on wave run-up on a slope dike in coastal protection engineering is studied as the main point. 相似文献
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分析了平面渡与桩列透空堤的相互作用.根据对矩形桩列上力平衡原理和非线性流阻等水动力学特征分析,导出一组计算反射、传递系数和波浪荷载的理论公式.计算公式内所有参数均是已知的,用它们预测的结果与现有的试验数据很好吻合. 相似文献
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A series of hydraulic model tests are carried out to investigate random wave run-up and overtopping on smooth, impermeable single slope and composite slope. Based on analysis of the influences of wave steepness, structure slope, incident wave angle, width of the berm and water depth on the berm and the wave run-up, empirical formulas for wave run-up on dike are proposed. Moreover, empirical formula on estimating the wave run-up on composite slope with multiple berms is presented for practical application of complex dike cross-section. The present study shows that the influence factors for wave overtopping are almost the same as those for wave run-up and the trend of the wave overtopping variation with main influence parameters is also similar to that for wave run-up. The trend of the wave overtopping discharge variations can be well described by two main factors, i.e. the wave run-up and the crest freeboard of the structure. A new prediction method for wave overtopping discharge is proposed for random waves. The proposed prediction formulas are applied to case study of over forty cases and the results show that the prediction methods are good enough for practical design purposes. 相似文献
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Based on the filtered Navier-Stokes equations and Smagorinsky turbulence model,a numerical wave flume is developed to investigate the overtopping process of irregular waves over smooth sea dikes.Simulations of fully nonlinear standing wave and regular wave’s run-up on a sea dike are carried out to validate the implementation of the numerical wave flume with wave generation and absorbing modules.To model stationary ergodic stochastic processes,several cases with different random seeds are computed for each specified irregular wave spectrum.It turns out that the statistical mean overtopping discharge shows good agreement with empirical formulas,other numerical results and experimental data. 相似文献
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1 .IntroductionIt has beenrealizedthat constructing gravitystructures onsoft soil foundations is a difficult task,especiallyinthe marine area where boththe geological and environmental conditions are severe .Thisisnot only because the bearing capacity of the soft foundation is relatively low, but also because thestrength of the soft soil will befurther weakened bythe waveloading (Andersenet al .,1988 ;Ander-sen and Lauritzsen,1988 ; Yasuhara ,1988) .The strength weakening may cause serious d… 相似文献