A method of spatial arrangement of offshore breakwaters for effective wave attenuation and changing currents

有效衰减波浪和改变水流的近海防波堤空间布置方法

• 批准号: 02650362
• 负责人: NAKAMURA Takayuki
• 金额: $ 1.41万
• 依托单位: Ehime University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650362/
• 关键词: Offshore breakwater system; Effective spatial array; Wave directional change; Wave height attenuation; Wave-induced current; Wave energy dissipation; Green's function method; 低反射効果; 波浪流; 波浪制御効果; 平面的配置; 波浪制御

In order to effectively attenuate incoming waves and control wave-induced currents, the spatial arrangement and allocation of offshore breakwaters is examined extensively. The following 3 topics have been especially dealt with in this study. (1)Wave dissipation mechanism and the resultant mean current features based on the vertical 2-D model of the breakwaters: Various types of breakwater, e.g. a concrete block breakwater, caisson breakwater, curtain-walled breakwater, floating breakwater and submerged breakwater, are used in order to clarify the wave dissipation mechanism of each type of breakwater. Characteristics of the mean current caused by the wave dissipation around the breakwater have been also studied. As a result, if is confirmed that the wave energy dissipation by the concrete block breakwater is mainly caused by the wave slamming inside the breakwater, wave breaking for the rubble mound breakwater, vortex formation around the angular or sharp corners for the curtain-walled … More breakwater and floating breakwater. It is also shown that the mean current around the breakwater has a close relation with the wave dissipation mechanism.(2)Effective arrangement and allocation of offshore breakwaters for reducing incoming waves: For all types of the breakwater used in this study, it is recommended that the pitch length between neighboring breakwaters should be less than the incident wave length because the generation of obliquely transmitted waves through the breakwater array is restrained. Furthermore, in the case of a floating breakwater array, the staggered array is very effective for reducing incoming waves if the projected gap length of the neighboring breakwaters on the array axis is equal to 0.(3)Effective arrangement and allocation of offshore breakwaters for changing the wave propagation direction: When the rectangular caisson is placed in such a way that the inclination angle from the array axis is in the range of 8 to 20 degrees, it is clarified that the obliquely propagating wave component becomes predominant in the lee side of the breakwater array. As a result, it is possible to control the intensity and direction of the wave induced current in the near shore region. Less

为了有效地衰减入射波和控制波生流，对近海防波堤的空间布置和配置进行了广泛的研究。本研究特别讨论了以下3个主题。(1)基于防波堤垂直二维模型的消波机理及由此产生的平均水流特征：采用混凝土块式防波堤、沉箱式防波堤、幕式防波堤、浮式防波堤、沉式防波堤等不同类型的防波堤，阐明各类型防波堤的消波机理。研究了防波堤周围波浪耗散引起的平均流特性。结果表明，混凝土砌块防波堤的波浪能耗散主要是由防波堤内部的波浪撞击、碎石丘防波堤的波浪破碎、幕墙防波堤在角角或尖角处形成的涡流等引起的。研究还表明，防波堤周围的平均水流与波浪耗散机制密切相关。(2)有效布置和配置近海防波堤以减少入射波：对于本研究中使用的所有类型的防波堤，建议相邻防波堤之间的节距长度应小于入射波长度，因为通过防波堤阵列产生的斜透射波受到了抑制。此外，在浮动防波堤阵中，当相邻防波堤在阵轴上的投影间隙长度为0时，交错阵对减小入射波非常有效。(3)改变波浪传播方向的海上防波堤的有效布置与配置：当矩形箱箱与防波堤阵轴线的倾角在8 ~ 20度范围内放置时，明确了在防波堤阵背风侧斜传播波分量占主导地位。因此，可以控制近岸区波浪感应流的强度和方向。少

项目成果

中村 孝幸: "矩形堤体列まわりの平面的な波変形の特性と波向き制御法に関する研究" 土木学会海岸工学論文集. 39. 536-540 (1992)

Takayuki Nakamura：“矩形堤坝阵列周围平面波变形特性和波向控制方法的研究”日本土木工程师学会学报，海岸工程学报 39. 536-540 (1992)。

中村 孝幸: "斜波中における浮体列まわりの波浪境界値問題の解析法に関する研究" 愛媛大学 工学部 紀要. 12-3. 249-259 (1993)

Takayuki Nakamura：“斜波中浮体周围波浪边值问题的分析方法”爱媛大学工学部通报12-3（1993）。

中村 孝幸: "直線配列された浮防波堤の波浪制御効果に関する研究" 土木学会海洋開発論文集. 8. (1992)

Takayuki Nakamura：“直线布置的浮动防波堤的波浪控制效果研究”日本土木工程师学会海洋开发学报8。（1992）。

中村 孝幸: "各種の平面形状を有する共振装置型堤体列の波浪制御効果について" 土木学会海岸工学論文集. 37. 529-533 (1990)

Takayuki Nakamura：“关于具有各种平面形状的谐振器型路堤阵列的波浪控制效果”，日本土木工程师学会会议记录，海岸工程学会，37. 529-533 (1990)。

中村 孝幸: "浮防波堤の平面的な配置法に関する研究" 土木学会海岸工学論文集. 39. 531-535 (1992)

Takayuki Nakamura：“浮动防波堤平面布置的研究”日本土木工程师学会会议录，海岸工程学39. 531-535（1992）。