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防波堤是港工建筑物中的一个重要组成部分,主要作用为保护港湾免受波浪、冰、沙等海洋动力因素的侵袭.综合以往的相关文献,对于防波堤断面破坏形式,如滑移、倾覆、地基滑动等有了非常充分的研究,可以定量计算出其损坏程度.而对于防波堤平面形态的损坏,如蛇行破坏等,只是较深入研究了失效机理,并没有一个能够定量计算其后果的模型.本文第一部分将期望滑移量模型和绕射模型结合,建立了计算半无限长沉箱式防波堤在使用期限内蛇行破坏程度的模型.第二部分则利用实测的波浪数据设计并计算了一个沉箱式防波堤实例.结果表明,各个堤段的期望滑移量呈现出一定周期性变化的规律,堤头附近区域的滑移量远大于较远的堤段,这对于防波堤施工过程中的堤头防护具有参考价值.本文为建立防波堤平面形态损坏定量计算模型提供了一种思路. 相似文献
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以山东省沿海港口为研究对象,采用基于IPCC第五次评价中RCP8.5情景的渤海、黄海海平面上升速率数据和山东省沿海地区地壳垂直运动速率数据,估算各港区自2019年到2100年相对海平面上升数据,获得以下研究结果:滨州港为0.956 m,东营港为0.794 m,潍坊港为0.47 m,龙口港为0.308 m,日照港为0.181 m,蓬莱港为0.143 m,烟台西港、烟台芝罘湾港区、威海港和青岛港均为0.14 m。结果表明,(1)相对海平面上升增大了港口航道的最大通行能力,其中,东营港、潍坊港、龙口港和滨州港最大通行能力绝对增加量大,分别为3.97×104t、3.5×104t、1.54×104t和1.54×104t;滨州港、东营港、潍坊港和龙口港相对增加量大,分别为51.21%、39.7%、35%和10.27%。(2)相对海平面上升使碎波线更接近防波堤,其中,滨州港、东营港和潍坊港,碎波线向防波堤移动距离大,分别为2 867 m、1 588 m和940 m。(3)相对海平面上升增大防波堤越浪量,其中,滨州港防波堤、东营港北防波堤和潍坊港中港区防波堤越浪量增长率高,分别为34.32%、34.17%和32.88%。(4)滨州港、东营港、潍坊港和龙口港应适时增大进、出港口轮船的最大吨位,以充分利用增大的最大通行能力的条件;滨州港、东营港和潍坊港应适时抛石或安装扭王字块来加固防波堤,以应对碎波线不断接近,激浪流冲击增强的不利影响,防止防波堤遭受破坏;滨州港应增高防波堤胸墙1 m以上,东营港北防波堤和潍坊港中港区防波堤应增加防波堤胸墙,高度分别在0.8 m以上和0.5 m以上,以防止越浪量增大对港池环境的干扰。研究结果和结论可为未来山东省沿海港口建设提供参考。 相似文献
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东营港防波堤平面设计及整体模型试验 总被引：1，自引：0，他引：1
在东营港港区现状的基础上,结合胜利油田黄河海港的远期规划,对南防波堤的走向、口门位置进行了多方案设计,并结合整体模型试验,对各方案进行了比较,选出了最佳方案。同时利用有色溶液模拟悬沙,对港区现状及按各方案布置防波堤时的港内冲淤进行了定性分析,为东营港的远期规划提供了科学依据。 相似文献
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为合理确定锚地布置,根据锚地抗风浪要求,采用综合考虑波浪折射、绕射、反射联合计算的港域不规则波数学模型进行爵溪防波堤锚地的波浪传播变形计算,提出锚地防波堤最为合理平面布置方案,满足了当地渔业生产泊锚安全。 相似文献
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沉箱防波堤兼作岸式波力发电装置是1种新型的港工建筑物,它是集合了防波堤与岸式振荡水柱波力发电装置的共性特点设计而成.本文主要是在物理模型的基础上,研究沉箱气室捕能效果.试验中主要采集了沉箱气室内的波高、气压以及输气管的空气流速等数据. 相似文献
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回顾了日本防波堤建造的历史，根据波浪力和防波堤稳定性讨论了当今混合式防波堤的设计方法。现在日本的混合式防波堤的设计技术是上来该领域经验和实际研究的鼎盛时期。对于混合式防波堤的绝大部分情况，能够精确地计算出设计波浪力的Ｇｏｄａ公式成了防波堤设计的极好工具，在某些情况下，由于波施于皮波堤上部直墙断面上的冲击压力非常大，因此在进行防波堤设计时必须予以考虑。要采用能够消散波浪力的混凝土块体覆盖在混合式防波 相似文献
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日本电力会社、中央研究所,研究成功两种新型,既降低建没费用,又提高性能的防波堤。今后在建设防波堤时,将采用其中的某一种。新型防波堤,是用混疑土预制的箱型结构,但与消波砌外型的防波堤不同。迄今的防波堤,上边是平面的。造价高,易磨耗,越波防止机能差。新型防波堤有两类。一是缝隙型,二是缓斜面型。 相似文献
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深水防波堤周围流场存在复杂的紊动变化,防波堤较容易发生失效破坏。本文利用PIV技术,基于模型实验,对规则波作用下防波堤周围的速度流场及其涡流特性进行了实验研究,获得了规则波流场的瞬时速度分布。通过对不同型式防波堤在不同的水力条件下的波浪流场实验数据的分析,定量地研究了防波堤堤身水域的涡旋流场的水力特性。 相似文献
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利用双频测深仪和声学多普勒流速仪对滨海港区附近海域进行了区域测深和定点全潮水文观测,通过与以往调查研究资料的对比,分析了防波堤建成前后海底冲淤变化特征。研究结果表明:近20年以来水下岸坡为侵蚀最剧烈的区域,海底平原则处于相对稳定状态;受自然侵蚀的影响,水下岸坡继续向岸内移,目前最强侵蚀区已内移至–8~–12 m水深的水下岸坡;近年来自然侵蚀明显减弱,年均侵蚀速率约为前10年的1/4;受防波堤挡流效应的影响,口门南侧已由往复流转变为旋转流;目前已出现三大淤积区域,其中以口门处淤积最严重,最大淤积厚达3.5 m,已造成口门处水深不足–10 m;防波堤对周边海域直接影响范围约13.4 km~2,最远可达废黄河口。分析认为,防波堤建设是引起港区海底冲淤格局发生变化的主因。该研究为防波堤的后续维护及滨海港区30万t级航道工程论证提供了基础资料。 相似文献
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Results of estimating the directional wave fields in front of a detached breakwater are presented here in this paper. Two of non-phase-locked methods, i.e., the Maximum Likelihood Method (MLM) and the Extended Maximum Entropy Principle Method (EMEP), were adopted for the purpose. In general, the latter outperforms the former. It is shown that the reflection coefficients decrease with increasing distances away from the detached breakwater, and within four wavelengths from the detached breakwater, the rate of the decrease is faster for wave fields having larger directional spreads. When the measuring distance is more than four wavelengths away from the detached breakwaters, the reflection coefficients tend to reach to a constant value. It is shown that, with the use of the non-phase-locked EMEP method, the effective region can be extended, as compared with the results of Huntley and Davidson [J. Waterw. Port Coast. Ocean Eng. 124 (1998) 312]. 相似文献
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Interaction Between Waves and A Comb-Type Breakwater 总被引：2，自引：1，他引：2
The characteristics of wave transmission, reflection and energy dissipation of comb-type caisson breakwaters are studied through laboratory physical model tests. Regular and irregular waves, with a wide range of wave heights and periods and a constant water depth, are considered. Different dimensions of each portion of the comb-type caisson breakwater are tested. Empirical formulae for calculating the reduction coefficient k, which is the ratio of horizontal wave force on unit length of the comb-type breakwater to that on unit length of the vertical wall breakwater, and for calculating the reflection coefficient of waves k, are obtained from the measurements. The comb-type caisson breakwater has been found to be very efficient in dissipating incident wave energy and in reducing wave reflection, and has already been used for the construction of an island breakwater in the Dayao Bay of Dalian Port, Liaoning Province, China. Compared with the cost of a common caisson breakwater, about 24. 5% of the investm 相似文献
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A numerical assessment study of tsunami attack on the rubble mound breakwater of Haydarpasa Port, located at the southern entrance of the Istanbul Bosphorus Strait in the Sea of Marmara, Turkey, is carried out in this study using a Volume-Averaged Reynolds-Averaged Navier-Stokes solver, IHFOAM, developed in OpenFOAM® environment. The numerical model is calibrated with and validated against the data from solitary wave and tsunami overflow experiments representing tsunami attack. Furthermore, attack of a potential tsunami near Haydarpasa Port is simulated to investigate effects of a more realistic tsunami that cannot be generated in a wave flume with the present state of the art technology. Discussions on practical engineering applications of this type of numerical modeling studies are given focusing on pressure distributions around the crown-wall of the rubble mound breakwater, and the forces acting on the single stone located behind the crown-wall at the rear side of the breakwater. Numerical modeling of stability/failure mechanism of the overall cross-section is studied throughout the paper.The present study shows that hydrodynamics along the wave flume and over the breakwater can be simulated properly for both solitary wave and tsunami overflow experiments. Stability of the overall cross-section can only be simulated qualitatively for solitary wave cases; on the other hand, the effect of the time elapsed during tsunami overflow cannot be reflected in the simulations using the present numerical tool. However, the stability of the overall cross-section under tsunami overflow is assessed by evaluating forces acting on the rear side armor unit supporting the crown-wall of the rubble mound breakwater as a practical engineering application in the present paper. Furthermore, two non-dimensional parameters are derived to discuss the stability of this armor unit; and thus, the stability condition of the overall cross-section. Approximate threshold values for these non-dimensional parameters are presented comparing experimental and numerical results as a starting point for engineers in practice. Finally, investigations on the solitary wave and tsunami overflow experiments/simulations are extended to the potential tsunami simulation in the scope of both representation of a realistic tsunami in a wave flume and stability of the rubble mound breakwater. 相似文献
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Mário Pereira Fernando Veloso-Gomes José Lima Sérgio Oliveira 《Marine Georesources & Geotechnology》2016,34(7):617-629
This article describes the implementation of a monitoring system on the breakwater at the Funchal Port (Madeira Island, Portugal) for the purpose of understanding its dynamic behavior and the temporal evolution of structural health. The monitoring system focuses on the breakwater superstructure and aims to identify the evolution of damage on the breakwater and analyze the impact of cruise ships docking and undocking. The system includes the measurement of displacements through geodetic techniques using global navigation satellite systems and the measurement of vibrations using accelerometers. Ten observation campaigns were performed over almost 3 years. As the measured displacements during this period were less than 7.5 mm it can be concluded that, despite some visible cracks, the breakwater superstructure did not suffer significant structural changes. It was shown from the measured acceleration records that some of the main modal parameters could be identified, namely the main natural frequencies of the superstructure. Through an analysis of the natural frequencies progression over time, it will be possible to identify deterioration effects on the foundation and/or the superstructure. The comparison of natural frequencies identified could be useful to evaluate the impact of these events on structural health. 相似文献
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A comparison of the diffraction of multidirectional random waves using several selected wave spectrum models is presented in this paper. Six wave spectrum models, Bretschneider, Pierson–Moskowitz, ISSC, ITTC, Mitsuyasu, and JONSWAP spectrum, are considered. A discrete form for each of the given spectrum models is used to specify the incident wave conditions. Analytical solutions based on both the Fresnel integrals and polynomial approximations of the Fresnel integrals and numerical solutions of a boundary integral approach have been used to obtain the two-dimensional wave diffraction by a semi-infinite breakwater at uniform water depth. The diffraction of random waves is based on the cumulative superposition of linear diffraction solution. The results of predicted random wave diffraction for each of the given spectrum models are compared with those of the published physical model presented by Briggs et al. [1995. Wave diffraction around breakwater. Journal of Waterway, Port, Coastal and Ocean Engineering—ASCE 121(1), 23–35]. Reasonable agreement is obtained in all cases. The effect of the directional spreading function is also examined from the results of the random wave diffraction. Based on these comparisons, the present model for the analysis of various wave spectra is found to be an accurate and efficient tool for predicting the random wave field around a semi-infinite breakwater or inside a harbor of arbitrary geometry in practical applications. 相似文献
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Zhang Fugui Ge Zhijin
Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing 《中国海洋工程》1996,(4)
- Rubble mound breakwater, one of the protection structures, has been widely used in coastal and port engineering. Block stones were first used as its armor layer, and its use was limited to shallow sea areas where there is no large waves. Since the specially-shaped armor unit was developed, the rubble mound breakwater has become the main sort of the protection structures, which can be used in deep water zones where storm sometimes occurs. Owing to severe and complex surrounding conditions, the rubble mound breakwater failure sometimes occurs, thus the study on the causes of failure is of great importance. In the present study some breakwater failures at home and abroad are illustrated and the causes of failure are investigated from the point of view of design, test, construction and maintenance. 相似文献
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毛里塔尼亚友谊港处于典型的强沿岸输沙型沙质海岸,年平均沿岸输沙量为90×10~4~100×10~4m~3。由于防波堤工程对上游沿岸输沙的拦截,港区岸线冲淤变化强烈。根据实测资料分析,采用基于"一线理论"的岸线演变数学模型,对友谊港上下游岸线变化作了整体验证,统筹分析了港口工程对上游淤积和下游冲刷的影响。在此基础上,进一步预测了友谊港未来20年的岸线变化情况。结果表明,在港区现有建筑物布置情况下,下游岸线的大幅冲刷将危及陆域土堤的安全,是友谊港未来防护的重点之一。若考虑每隔一定年限在下游增建丁坝工程,形成丁坝群护岸工程,可延长下游岸线的冲刷防护范围,减小对陆域建筑物的威胁。 相似文献