JPH0686724B2 - Seawater AC breakwater - Google Patents
Seawater AC breakwaterInfo
- Publication number
- JPH0686724B2 JPH0686724B2 JP62322770A JP32277087A JPH0686724B2 JP H0686724 B2 JPH0686724 B2 JP H0686724B2 JP 62322770 A JP62322770 A JP 62322770A JP 32277087 A JP32277087 A JP 32277087A JP H0686724 B2 JPH0686724 B2 JP H0686724B2
- Authority
- JP
- Japan
- Prior art keywords
- seawater
- breakwater
- port
- cross
- sectional area
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A10/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE at coastal zones; at river basins
- Y02A10/11—Hard structures, e.g. dams, dykes or breakwaters
Landscapes
- Revetment (AREA)
Description
【発明の詳細な説明】 (産業上の利用分野) 本発明は、港外の海水を港内に交流させる海水交流防波
堤に関する。Description: TECHNICAL FIELD The present invention relates to a seawater AC breakwater that exchanges seawater outside the port with the inside of the port.
(従来の技術) 従来、港内の水質保全のために使用される海水交流防波
堤1のあるものは、第7図に示すように防波堤本体2を
港外3と港内4とを区画するように設け、この防波堤本
体2の下部に単なる流通路5を港外3と港内4を連通す
るように設けて、波力などにより海水交流を図るように
したものや、第8図に示すように流通路5の港外側に損
失の少ないベルマウス形部5Aを設けるとともに港内側に
損失の大きい突出部5Bを設け、波力による流入・流出量
に差を生じさせて港内への流入量を多くせんとしたも
の、更に第9図に示すように流通路5の港内側の開口部
にフラツターバルブ6を設け、港外からの波力による海
水の侵入時には開き、港内からの流出を阻止させるよう
にしたもの等が一般的であった。(Prior Art) Conventionally, in some of the seawater AC breakwaters 1 used for water quality conservation in a port, a breakwater main body 2 is provided so as to divide an outside port 3 and an inside port 4 as shown in FIG. A mere flow passage 5 is provided at the bottom of the breakwater main body 2 so as to connect the harbor 3 and the harbor 4 so that the seawater can be exchanged by wave force or the like, or as shown in FIG. The bellmouth shaped part 5A with less loss is installed on the outside of port 5 and the protrusion 5B with more loss is installed on the inside of the port to increase the inflow and outflow by the wave force and increase the inflow into the port. In addition, as shown in FIG. 9, a flatter valve 6 is provided at the opening inside the port of the flow passage 5 so that it opens when seawater enters due to wave force from outside the port and prevents outflow from inside the port. What was done was common.
(発明が解決しようとする問題点) しかし、第7図に示すような構造では、水深に比べて波
高が小さい場合には、港外3の波は正弦波形となり、こ
のため流通路5内では流量が全く等しい往復流となり、
流入量が期待できない。また、第7図〜第9図に示すい
ずれのタイプのものも、港外3の波による圧力変化が流
通路5を通して直接港内4へ伝播するため、港内4に新
たな伝達波を生じさせ、防波堤1の本来の目的である消
波の面で致命的な問題となっている。(Problems to be solved by the invention) However, in the structure as shown in FIG. 7, when the wave height is smaller than the water depth, the wave outside the harbor 3 has a sinusoidal waveform, so that in the flow passage 5 It becomes a reciprocating flow with exactly the same flow rate,
Inflow cannot be expected. Further, in any of the types shown in FIGS. 7 to 9, the pressure change due to the wave outside the port 3 propagates directly into the port 4 through the flow passage 5, so that a new transmission wave is generated in the port 4. This is a fatal problem in terms of wave breaking, which is the original purpose of the breakwater 1.
このような従来の問題にかんがみ、本発明は、港内を静
穏に保ちつつ港湾水域の水質保全を図ることができる海
水交流防波堤を提供することを目的としたものである。In view of such conventional problems, the present invention has an object to provide a seawater AC breakwater capable of conserving the water quality of the harbor water area while keeping the harbor quiet.
(問題点を解決するための手段) 上述のごとき従来の問題を解決し、所期の目的を達成す
るための本発明の要旨とするところは、港外と港内とを
区画して防波堤本体が設けられ、該防波堤本体の上部に
は港外側に入口が開口した海水導入路が設けられ、該海
水導入路の最奥部下側には該海水導入路に連通した固有
振動周期調整用貯留水槽が設けられ、該貯留水槽の下部
から前記防波堤本体の下部港内側に連通させて排水路が
設けられ、前記海水導入路は水平方向の路幅を奥部に向
かうにつれて狭くする収れん側壁を有し、かつ前記の固
有振動周期調整用貯留水槽内における水面の固有振動周
期の1/2が港外の通常の波の周期と同じになるように、
該貯留水槽の断面積と前記の排水路の断面積並びに長さ
が設定され、かつ前記貯留水槽の断面積を、前記排水路
の断面積より大きくしたことを特徴とする海水交流防波
堤に存する。(Means for Solving Problems) The gist of the present invention for solving the above-mentioned conventional problems and achieving the intended purpose is that the breakwater main body is divided into an outside port and an inside port. A seawater introducing passage having an inlet opening to the outside of the harbor is provided on the upper part of the breakwater main body, and a natural vibration period adjusting reservoir tank communicating with the seawater introducing passage is provided under the deepest part of the seawater introducing passage. Provided, a drainage channel is provided in communication with the inside of the lower port of the breakwater main body from the lower portion of the reservoir tank, the seawater introduction channel has a converging side wall that narrows the horizontal channel width toward the inner part, And so that 1/2 of the natural vibration period of the water surface in the reservoir tank for adjusting the natural vibration period is the same as the normal wave period outside the port,
The seawater AC breakwater is characterized in that the cross-sectional area of the storage water tank, the cross-sectional area and the length of the drainage channel are set, and the cross-sectional area of the storage water tank is larger than the cross-sectional area of the drainage channel.
(作用) この海水交流防波堤は、港外より押し寄せる波が防波堤
本体の前面に衝突し、一部は反射し、他は海水導入路の
開口部から侵入する。侵入した波は収れん側壁に沿って
水位が高められながら奥部に侵入し、撹乱状態となって
エネルギーを消費しながら内部の貯留水槽内に流入し、
この貯留水槽の底部から排水路を通って港内に流入され
る。(Function) In this seawater AC breakwater, the waves rushing from outside the port collide with the front surface of the breakwater main body, part of which is reflected, and the other enters through the opening of the seawater introduction passage. The invading waves invade the inner part while the water level is raised along the converging side wall, become a disturbing state and consume energy, and flow into the internal storage tank,
The water flows from the bottom of this reservoir to the port through the drainage channel.
貯留水槽における海水の流出速度には、貯留水槽の断面
積と排水路の断面積並びにその長さに応じて固有の振動
数があり、この半周期を予め港外の平均的な通常の波の
周期と合わせて成形しておくことにより、侵入する波に
同調して常時港内への流入がなされることとなる。The outflow velocity of seawater in the storage tank has a natural frequency depending on the cross-sectional area of the storage tank, the cross-sectional area of the drainage channel, and its length. By shaping it together with the period, the waves will always flow into the port in synchronization with the invading waves.
(実施例) 次に本発明の実施の一例を第1図〜第3図について説明
する。(Example) Next, an example of implementation of the present invention will be described with reference to Figs.
この海水交流防波堤は、防波堤本体11を港外3と港内4
とを区画する配置に設けている。この防波堤本体11には
その港外3側の面(前面12)に海水導入路13が開口され
ている。この海水導入路13の最奥部下に貯留水槽14が設
けられ、この貯留水槽14の底部と防波堤本体11の背面15
の下部との間に排水路16が設けられている。In this seawater AC breakwater, the breakwater main body 11 is placed outside the port 3 and inside the port 4
It is provided in an arrangement that partitions and. In this breakwater main body 11, a seawater introduction path 13 is opened on the surface (front surface 12) on the outside 3 side. A reservoir tank 14 is provided below the innermost portion of the seawater introducing passage 13, and the bottom of the reservoir tank 14 and the back surface 15 of the breakwater main body 11 are provided.
A drainage channel 16 is provided between the drainage channel 16 and the lower part of the.
海水導入路13は水平配置の天井壁17と、奥部に向かうに
連れて高くし全体が水没している水没底壁18と、海水導
入路13の水平方向の路幅を奥部に向かうにつれて狭くす
る収れん側壁19a,19bとに囲まれて形成されている。The seawater introducing passage 13 has a horizontally arranged ceiling wall 17, a submerged bottom wall 18 that is raised toward the back and is entirely submerged in water, and the horizontal passage width of the seawater introducing passage 13 increases toward the back. It is formed so as to be surrounded by the converging side walls 19a and 19b which are narrowed.
貯留水槽14は、その上部の前面12側に海水導入路13が連
通されており、その水平断面積と排水路16の断面積と長
さによって、海水が排水路16を通じて流出入する際の貯
留水槽14内の水面の上下は固有の振動周期をもってお
り、その固有振動周期の1/2を港外3側の通常の波の周
期と同じになるように予め設定しておく。The storage water tank 14 has a seawater introduction passage 13 communicating with the front surface 12 side of the upper portion thereof, and the storage when the seawater flows in and out through the drainage passage 16 due to the horizontal cross-sectional area and the cross-sectional area and length of the drainage passage 16. The upper and lower sides of the water surface in the water tank 14 have a natural vibration cycle, and 1/2 of the natural vibration cycle is set in advance so as to be the same as the normal wave cycle on the outside 3 side.
次に、この海水交流防波堤の作用について説明する。Next, the action of this seawater AC breakwater will be described.
一般に、第4図に示すように管路Aで連通された2つの
水槽A1,A2において、水槽A1の水面を時刻t=0におい
て強制的に約10cm程度上昇させた後の水面自由振動波形
は第5図(イ)に示す如くであり、また、その際の管内
流速波形は第5図(ロ)に示す如くである。Generally, as shown in FIG. 4, in the two water tanks A1 and A2 communicated with each other by the pipeline A, the water surface free vibration waveform after forcibly raising the water surface of the water tank A1 by about 10 cm at time t = 0 is It is as shown in FIG. 5 (a), and the flow velocity waveform in the pipe at that time is as shown in FIG. 5 (b).
本発明の実施例の防波堤においても、このような連通2
水槽の水の運動原理に基づいており、水槽A2を港内4水
域(断面積無限大)とすると水槽A1は貯留水槽14に対応
し、その水面固有振動周期(Ts)は次式で近似される。Even in the breakwater of the embodiment of the present invention, such communication 2
Based on the principle of water movement in the water tank, assuming that water tank A2 is 4 water areas in the harbor (infinite cross-sectional area), water tank A1 corresponds to reservoir water tank 14, and its natural vibration period (Ts) is approximated by the following equation. .
ここにA1;A1水槽(貯留水槽14)の断面積 A;管路A(排水路16)の断面積 l;管路A(排水路16)の長さ g;重力加速度 式(1)で求められる本実施例の防波堤本体11の貯留水
槽14の水面固有振動周期Tsの1/2が、港外3から海水導
入路13に導入される入射波の周期と一致すると、貯留水
槽14の水面振動時系列波形を模式的に示せば第6図
(イ)のようになり、またその際の排水路16内の流速時
系列波形は第6図(ロ)のようになる。 Where A 1 ; cross-sectional area of A1 water tank (reservoir 14) A; cross-sectional area of pipeline A (drainage channel 16) l; length of pipeline A (drainage channel 16) g; gravitational acceleration Equation (1) When half of the natural oscillation period Ts of the water surface of the storage tank 14 of the breakwater main body 11 of the present example required coincides with the cycle of the incident wave introduced from the port outside 3 into the seawater introducing passage 13, the water surface of the storage tank 14 The vibration time-series waveform is schematically shown in FIG. 6 (a), and the flow velocity time-series waveform in the drainage channel 16 at that time is as shown in FIG. 6 (b).
即ち、貯留水槽14の水面自由振動により水面が最下位に
なったとき(Ts/2時)に入射波が来襲すると瞬間的に水
位が最大となり、その後は再び自由振動に移行する。従
って排水路16内の流速はTs/4時に最大に、Ts/2時にゼロ
となり、流速は常時正側、即ち流入側で変動することと
なり、常に海水の流入を得ることができる。That is, when the incident wave strikes when the water surface is at the lowest level (Ts / 2 o'clock) due to the free vibration of the water surface of the stored water tank 14, the water level instantaneously becomes the maximum, and then the free vibration is resumed. Therefore, the flow velocity in the drainage channel 16 becomes maximum at Ts / 4 and becomes zero at Ts / 2, and the flow velocity always fluctuates on the positive side, that is, the inflow side, so that the inflow of seawater can always be obtained.
なお、この実施例の防波堤の波高伝達率と反射率につい
て検討したところ、前述したように貯留水槽14の水面固
有振動周期1/2と入射波の周期が同期したときの波高伝
達率は5%以下、反射率30%程度となることが実験によ
り確かめられた。また、この種の防波堤の能力を評価す
る指標として、次式で示されるエネルギーロス(Klos
s)がある。When the wave height transmissivity and the reflectance of the breakwater of this example were examined, as described above, the wave height transmissibility when the water surface natural oscillation period 1/2 of the storage tank 14 and the period of the incident wave were synchronized was 5%. Hereinafter, it was confirmed by experiments that the reflectance was about 30%. In addition, as an index for evaluating the capacity of this type of breakwater, the energy loss (Klos
s).
ここにKr;反射率 Kt;波高伝達率 本実施例の防波堤では、海水交換効果が最大のとき、Kr
=0.30、Kt=0.05とすると、Kloss=0.953となり、波の
エネルギーの95%が流れのエネルギーに変換されると考
えられ、波浪低減及び低伝達波の効果を有する。 Here, Kr; reflectance Kt; wave height transmissivity In the breakwater of this embodiment, when the seawater exchange effect is maximum, Kr
= 0.30 and Kt = 0.05, Kloss = 0.953, and it is considered that 95% of the wave energy is converted to flow energy, which has the effect of wave reduction and low transmission waves.
(発明の効果) 本発明の海水交流防波堤は上述の如く構成され、収れん
側壁を有する海水導入路を設け、その奥部に固有振動周
期調整用貯留水槽が設けられていることにより、港外か
ら打ち寄せる波浪の大部分が海水導入路における流れの
エネルギーに変換されて消費されることとなり、また、
貯留水槽に導入される波は自然流過によって港内側に排
出されるため、港内の静穏が維持されつつ海水の交流が
なされることとなり、また、貯留水槽の水面固有振動周
期の1/2を入射波の周期に合わせることにより、常時港
外側の海水が港内側に導入されることとなり、活溌な海
水交流がなされることとなったものである。(Effects of the Invention) The seawater AC breakwater of the present invention is configured as described above, and is provided with a seawater introduction path having a converging side wall, and the natural vibration period adjustment reservoir tank is provided at the back of the seawater AC breakwater. Most of the rushing waves are converted into the energy of the flow in the seawater introduction channel and consumed, and
Since the waves introduced into the storage tank are discharged inside the port by natural flow-through, the calm in the port is maintained and the seawater is exchanged, and half of the natural oscillation period of the water surface of the storage tank is maintained. By adjusting the cycle of the incident wave, seawater outside the harbor was always introduced inside the harbor, and a vigorous exchange of seawater was achieved.
第1図は本発明の実施例の一例の防波堤を示す縦断面
図、第2図は同正面図、第3図は第1図中のIII-III線
断面図、第4図は同実施例の作用を説明するための連通
2水槽を示す断面図、第5図(イ)は第4図の連通2水
槽の水面自由振動波形を示すグラフ、同(ロ)は管内流
速波形を示すグラフ、第6図(イ)は貯留水槽の水面振
動時系列波形を示すグラフ、同(ロ)は排水路の流速時
系列波形を示すグラフ、第7図〜第9図は従来の防波堤
の3種類の例を示す縦断面図である。 11……防波堤本体、13……海水導入路、14……貯留水
槽、16……排水路、18……水没底壁、19a,19b……収れ
ん側壁。FIG. 1 is a longitudinal sectional view showing a breakwater according to an embodiment of the present invention, FIG. 2 is a front view of the same, FIG. 3 is a sectional view taken along line III-III in FIG. 1, and FIG. 5 is a cross-sectional view showing the communication 2 water tank for explaining the action of FIG. 5, FIG. 5 (a) is a graph showing the water surface free vibration waveform of the communication 2 water tank of FIG. 4, and FIG. 5 (b) is a graph showing the pipe flow velocity waveform, FIG. 6 (a) is a graph showing a time-series waveform of water surface vibration of the reservoir tank, FIG. 6 (b) is a graph showing a time-series waveform of flow velocity of the drainage channel, and FIGS. 7 to 9 are three types of conventional breakwaters. It is a longitudinal cross-sectional view showing an example. 11 …… Breakwater main body, 13 …… Seawater introduction channel, 14 …… Storage tank, 16 …… Drainage channel, 18 …… Submerged bottom wall, 19a, 19b …… Convergent side wall.
Claims (1)
られ、該防波堤本体の上部には港外側に入口が開口した
海水導入路が設けられ、該海水導入路の最奥部下側には
該海水導入路に連通した固有振動周期調整用貯留水槽が
設けられ、該貯留水槽の下部から前記防波堤本体の下部
の港内側に連通させて排水路が設けられ、前記海水導入
路は水平方向の路幅を奥部に向かうにつれて狭くする収
れん側壁を有し、かつ前記の固有振動周期調整用貯留水
槽内における水面の固有振動周期の1/2が港外の通常の
波の周期と同じになるように、該貯留水槽の断面積と前
記の排水路の断面積並びに長さが設定され、かつ前記貯
留水槽の断面積を、前記排水路の断面積より大きくした
ことを特徴とする海水交流防波堤。1. A breakwater main body is provided to partition the outside of the harbor and the inside of the harbor, and a seawater introduction passage having an opening to the outside of the harbor is provided at an upper portion of the breakwater main body, and a bottom of the deepest part of the seawater introduction passage is provided. Is provided with a reservoir tank for adjusting the natural vibration period, which communicates with the seawater introduction passage, and a drainage passage is provided so as to communicate from the lower portion of the reservoir tank to the inside of the port at the lower portion of the breakwater main body, and the seawater introduction passage is horizontal. Has a converging side wall that narrows the road width in the direction toward the back, and 1/2 of the natural vibration cycle of the water surface in the storage tank for adjusting the natural vibration cycle is the same as the normal wave cycle outside the port The cross-sectional area of the storage tank and the cross-sectional area and length of the drainage channel are set so that the cross-sectional area of the storage water tank is larger than the cross-sectional area of the drainage channel. AC breakwater.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62322770A JPH0686724B2 (en) | 1987-12-22 | 1987-12-22 | Seawater AC breakwater |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62322770A JPH0686724B2 (en) | 1987-12-22 | 1987-12-22 | Seawater AC breakwater |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH01165811A JPH01165811A (en) | 1989-06-29 |
JPH0686724B2 true JPH0686724B2 (en) | 1994-11-02 |
Family
ID=18147450
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP62322770A Expired - Fee Related JPH0686724B2 (en) | 1987-12-22 | 1987-12-22 | Seawater AC breakwater |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0686724B2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001159115A (en) * | 1999-12-02 | 2001-06-12 | Mitsui Eng & Shipbuild Co Ltd | Sea water purifying revetment ad quay wall |
JP2020056299A (en) * | 2019-12-04 | 2020-04-09 | 長谷川 誠 | Structure of aerial city |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100414348B1 (en) * | 2000-12-18 | 2004-01-07 | 한국해양연구원 | A structure for seawater exchange using a resonant basin |
KR100414350B1 (en) * | 2000-12-29 | 2004-01-07 | 한국해양연구원 | A structure for seawater exchange using a resonant basin |
JP2003096742A (en) * | 2001-09-20 | 2003-04-03 | Ishikawajima Harima Heavy Ind Co Ltd | Sea-water crossflow breakwater caisson |
JP4446837B2 (en) | 2004-08-26 | 2010-04-07 | ポップリベット・ファスナー株式会社 | Connecting device |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS54105830A (en) * | 1978-02-08 | 1979-08-20 | Penta Ocean Construction | Harbor structure of breakwater* etc* |
JPS62244906A (en) * | 1986-04-18 | 1987-10-26 | Penta Ocean Constr Co Ltd | Ocean water cross-current breakwater |
-
1987
- 1987-12-22 JP JP62322770A patent/JPH0686724B2/en not_active Expired - Fee Related
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001159115A (en) * | 1999-12-02 | 2001-06-12 | Mitsui Eng & Shipbuild Co Ltd | Sea water purifying revetment ad quay wall |
JP2020056299A (en) * | 2019-12-04 | 2020-04-09 | 長谷川 誠 | Structure of aerial city |
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