JP2003096742A - Sea-water crossflow breakwater caisson - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reduce a wave reflection coefficient in a sea-water crossflow breakwater caisson preventing waves on the outside of the day from reaching the inside of a bay while effectively conducting the crossflow of sea water on the outside of the bay and sea water on the inside of the bay. SOLUTION: In the sea-water crossflow breakwater caisson 100 having headraces 13 for sea water in a skeleton 10 and having cross-over top sections 11 for sea water at the rear sections of the headraces 13, reflection-preventive columns 22, in which front sections are broad and right and left widths are reduced towards the front sides and which have pointed sections 25 and have an approximately triangular horizontal sectional shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seawater AC breakwater caisson, which can take in seawater outside the bay into the bay and prevent waves from outside the bay from reaching the bay. The present invention relates to a seawater AC breakwater caisson that can effectively reduce

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 6, a harbor has been provided with a breakwater A for partitioning the outside and the inside of the harbor to prevent ocean waves S from reaching the inside of the harbor. Also, breakwater A
The function of is to reduce the wave transmittance that prevents the ocean waves S from reaching the bay in this way, and at the same time, to the breakwater A
Therefore, it is necessary to reduce the wave reflectance to prevent the problem that the wave S is reflected and the reflected wave S ′ exerts a bad influence on a fishing ground in the open sea or a ship traveling.

Furthermore, since the inland sea in the bay, which is closed to the open sea by the breakwater A, is calm against natural conditions such as waves of the open sea, mooring of ships, construction of critical factories, etc.
It is used for various purposes such as the installation of aquaculture cages,
Since the bay partitioned by the breakwater A is closed, it is difficult to exchange (exchange) with seawater in the open sea, which seriously poses a problem of contaminating seawater in the bay. There is a strong demand for the development of breakwaters that can be conserved.

In order to meet these demands, conventionally,
A seawater AC breakwater caisson constructed of concrete or a hybrid structure of steel and concrete has been proposed.

FIG. 7 shows an example of the construction of a conventional seawater AC breakwater caisson. The seawater AC breakwater caisson 1 shown in FIG. 7 is a box-shaped structure composed of a bay outer plate 2, a bay inner plate 3, a top plate 4 and a bottom plate 5. The breakwater main body 6 is provided in such a size that it is half-submerged at a required depth from the sea surface.

The bay outer plate 2 of the breakwater main body 6 has a vertically long slit mouth 7 extending above and below the sea level L (tide level).
A plurality of (headraces) are formed laterally at required intervals. At this time, since the bay outer plate 2 needs to maintain its strength while forming the slit ports 7, the vertical plate 2a having a required width is left between the slit ports 7.

On the inner side plate 3 of the bay, below the sea level L,
A plurality of water outlets 8 that connect the inside of the breakwater main body 6 and the inside of the bay are formed laterally with a required interval. Further, an intermediate plate 9 extending from the bottom plate 5 to near the sea level L (tide level) and forming a climbing top 9a is provided between the outer bay plate 2 and the inner bay plate 3 in the breakwater main body 6.

In the seawater AC breakwater caisson 1 shown in FIG. 7, a part of the wave S from the outside of the bay in the direction of the arrow is reflected by hitting the vertical surface plate 2a of the outer plate 2 of the bay, and the remaining wave S is in the headrace. After passing through a certain slit mouth 7 and entering the breakwater main body 6, the water passes between the intermediate plate 9 and the bay inner side plate 3 by climbing over the top 9a of the intermediate plate 9 to raise the water level between the intermediate plate 9 and the bay inner side plate 3. The seawater is exchanged by flowing the seawater into the bay from the water outlet 8 by the pumping action of the seawater between the seawater and the seawater.

In the seawater AC breakwater caisson 1 described above,
Since the waves S pass over the intermediate plate 9 and collide with the inner plate 3 of the bay and flow into the bay through the water outlet 8, the waves S are hardly transmitted into the bay, and the wave transmittance can be suppressed low.

However, as described above, the waves that have entered the breakwater main body 6 through the slit mouth 7 have passed over the intermediate plate 9 and have passed over the apex 9a.
Since the sea level rises between them and the seawater flows into the inside of the bay from the water outlet 8 by the pump action and the seawater exchange is performed, the seawater that has passed over the intermediate plate 9 collides with the inside plate 3 of the bay. It returns to the outside of the bay of the intermediate plate 9 again, so that the pump action is not effectively exerted and there is a problem that the inflow of seawater to the inside of the bay is small. Especially, when the height of the wave S is low, the pump action is sufficient. There is a problem that the flow of seawater that flows into the bay does not work, and the flow of seawater further decreases, and good seawater exchange cannot be performed.

Further, the wave S that collides with the vertical surface plate 2a of the bay outer plate 2 having the above-mentioned slit mouth 7 is the vertical surface plate 2a.
There is a problem that the wave reflectance is large because it reflects according to the area of a and generates a wave toward the outside of the bay.

In order to solve such a problem, the applicant of the present patent application first applied for a seawater AC breakwater caisson having a seawater introduction slope as shown in Japanese Patent Application No. 2000-109506. 8 and 9 are Japanese Patent Application No. 2000-10950.
7 shows a seawater AC breakwater caisson having a structure substantially similar to the structure shown in No. 6.

The seawater AC breakwater caisson 100 shown in FIG. 8 and FIG. 9 climbs over the inside rear part of the bay above the skeleton 10 and the top part 1
1 and a seawater introduction slope 12 having a downward slope inclined from the overpassing top 11 toward the front outside the bay at a required inclination angle α.
It is equipped with a water conduit 13.

A ceiling wall 14 is provided on the upper portion of the water conduit 13, and an outer end of the bay of the ceiling wall 14 is bent downward so that the lower end is equal to or higher than the sea level L height. The intake port 15 is formed.

An inner bay end portion of the ceiling wall 14 has a rear wall 16 extending downward from the rear surface of the skeleton 10 with a required space.
And it is immersed below the sea level L.
A water retaining portion 17 is formed between the rear surface and the rear surface, and a water outlet 18 is formed in the lower portion of the rear wall 16.

In the case of FIG. 9, the skeleton 10 shows a case where a plurality of skeleton blocks 10a (four in the figure) are laterally arranged and integrally assembled or fastened. However, the number of the skeleton blocks 10a can be arbitrarily selected. In FIG. 8, 19 is a wave-dissipating body placed on the upper part of the seawater AC breakwater caisson 100 in which the skeleton block 10a is integrated, and the inside of the skeleton block 10a is filled with concrete or earth and sand. Things are to be filled. On the other hand, there may be a seawater AC breakwater caisson in which the upper part of the water conduit 13 is opened without providing the ceiling wall 14 on the upper part of the water conduit 13.

As shown in FIGS. 8 and 9, in order to form the water conduit 13 having the seawater intake port 15 in the skeleton 10, the skeleton 1
In order to maintain 0 strength, as shown in FIG.
Side walls 20 having a required width X need to be provided on the left and right side portions of the. Therefore, the upright wall surface 21 exists on the front side of the side wall 20 on the outer side of the bay.

The inclination angle α of the downward slope of the seawater introduction slope 12 is, for example, about 10 to 40 ° with respect to the horizontal plane, and the front-back length of the seawater introduction slope 12 (length in the left-right direction in FIG. 8). Is about 1/30 or more of the wavelength of the wave S traveling toward the seawater introduction slope 12. Further, in the seawater AC breakwater caisson 100 of FIG. 9, the height of the headrace 13 formed in each skeleton block 10a is set to the average tide level L so that the effect can be exhibited even if the height of the sea surface L changes. On the other hand, the case where the heights are alternately different from each other is shown.

In the seawater AC breakwater caisson 100 shown in FIGS. 8 and 9, when the wave S at the tide level L acts from the outside of the bay, the wave S is extinguished by the seawater introduction slope 12 and the seawater introduction slope of FIG. It moves so as to ride up on the right side of 12, and over the top portion 11 of the vehicle, and falls to the water retaining portion 17 inside the bay of the skeleton 10. When seawater falls into the water repellent portion 17, the water level of the water repellent portion 17 rises, so that the seawater of the water repellent portion 17 is pushed out of the water outlet 18 toward the inside of the bay by the pump action, and seawater exchange is performed.

As described above, the wave S is the seawater introduction slope 1
Since the seawater is dissipated by 2 and rides on the seawater introduction slope 12, it is designed to climb over the seawater top 11 and fall to the water retaining portion 17, so that the seawater dropped to the water retaining portion 17 does not return to the outside of the bay. Therefore, the seawater that has fallen into the water retaining portion 17 surely exerts a pumping action and flows out from the water outlet 18, so that the inflow amount of seawater into the bay increases and good seawater exchange can be performed.

Further, the seawater AC breakwater caisson 1 described above
At 00, the waves S that have passed over the seawater introduction slope 12 and over the apex 11 collide with the rear wall 16 and fall into the water retaining portion 17, so that the waves S are not transmitted to the inside of the bay and the wave transmittance is suppressed to a low level. be able to.

As described above, according to the seawater AC breakwater caisson 100 shown in FIGS. 8 and 9, excellent seawater AC and reduction of the wave transmittance can be achieved.

[0023]

However, also in the seawater AC breakwater caisson 100 described above, as shown in FIG. 10, the side wall 20 provided to form the water conduit 13 is formed.
Since the upright wall surface 21 exists on the outside front surface of the bay, the wave S toward the seawater AC breakwater caisson 100 collides with the upright wall surface 21 and is reflected, which causes a wave S ′ out of the bay. Have a problem.

Therefore, also in the seawater AC breakwater caisson 100 shown in FIGS. 8 and 9, it is required to reduce the reflected wave generated by the upright wall surface 21 toward the outside of the bay.

The present invention has been made to solve the above problems, and prevents waves outside the bay from reaching the inside of the bay and enables effective exchange between the seawater outside the bay and the seawater inside the bay. It is an object of the present invention to provide a seawater AC breakwater caisson capable of effectively reducing the wave reflectance in the existing seawater AC breakwater caisson.

[0026]

The seawater AC breakwater caisson according to claim 1 is a seawater AC breakwater caisson having a seawater headrace on its skeleton, and a seawater surmounting apex at the rear of the headrace. An anti-reflective column with a wide rear part and narrow left and right parts toward the front and sharpened parts with a horizontal cross-sectional shape of a substantially triangular shape was fixed to the upright wall surface on the outer front of the bay between the headraces. Is characterized by.

The seawater AC breakwater caisson according to claim 2 is characterized in that the horizontal cross-sectional shape of the antireflection column is substantially triangular.

The seawater AC breakwater caisson according to claim 3 is a seawater AC breakwater caisson provided with a seawater conduit in the skeleton, and a seawater transcendental apex at the rear of the conduit, which is formed in the skeleton. It is characterized in that an inclined surface having a sharpened portion is formed in the front part on the outer side of the bay, the width dimension of which is reduced to the left and right toward the outer side of the bay.

In the seawater AC breakwater caisson according to claim 4, the water conduit provided in the skeleton according to claim 1 or 2 has a climbing top on the upper part of the inner rear part of the bay, and from the top of the riding part to the front part outside the bay. It is characterized by having a seawater introduction slope that is inclined downwardly toward the seawater.

According to the above means, it operates as follows.

In the seawater AC breakwater caisson according to the first and second aspects, the rear wall is wide and the left and right width decreases toward the front side on the upright wall surface on the outside front of the bay between the headraces formed in the skeleton. For example, an anti-reflection column with a sharp cross section that has a substantially triangular horizontal cross-section is fixed, so the front part of the outer side of the bay between the headraces is tapered toward the outside of the bay, and therefore waves traveling toward the seawater AC breakwater caisson are reflected. The sloped surface of the prevention column divides the flow to the left and right to the headrace, and does not cause reflected waves due to the upright wall surface outside the bay between the headraces.

In the seawater AC breakwater caisson according to claim 3, an inclined surface having a sharpened portion is formed at the front part outside the bay between the headraces formed in the skeleton so that the width dimension on the left and right decreases toward the outside of the bay. Since it was formed, the front part outside the bay between the headraces has a tapered shape toward the outside of the bay, so that the waves heading to the seawater AC breakwater caisson are diverted to the left and right by the inclined surface and head inside the headrace. Do not generate reflected waves from the upright wall at the outer front of the bay between the headraces.

Further, in the seawater AC breakwater caisson according to claim 4, the water conduit provided in the skeleton has a climbing apex at the upper part of the inner rear part of the bay, and descends from the aboard top to the outer front part of the bay. Since it has a seawater introduction slope that is inclined at a slope, the waves shunted to the left and right by the slope will collide from the lateral direction against the waves that are extinguished by riding on the seawater introduction slope. By further disturbing the wave introduced into the body, the wave-dissipating action of the body is enhanced.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an oblique front view of an example of the embodiment of the present invention applied to the seawater AC breakwater caissons of FIGS. 8 and 9 as seen from the outside of the bay, and FIG. 2A is a partial horizontal view of FIG. It is the top view cut and shown in FIG. In the figure, the same parts as those in FIGS. 8 and 9 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIGS. 1 and 2 (A), the frame 10 is
Seawater AC breakwater caisson provided with a headway 13 on the inside of the bay, and a headrace 13 having a seawater introduction slope 12 with a required inclination angle α from the landing top 11 to the outside of the bay. In 100, an anti-reflective column 22 having a substantially triangular horizontal cross-section whose rear part is wide and whose width decreases toward the front side is provided on an upright wall face 21 on the outer front part of the bay by a side wall 20 for forming a water conduit 13 in the skeleton 10. To fix. Due to the antireflection column 22, a sharpened portion 25 is formed on the front portion of the side wall 20 by a tapered inclined surface 22a toward the outside of the bay.

At this time, it is preferable that the surface of the antireflection column 22 facing the skeleton 10 has a width equal to the width X of the upright wall surface 21 shown in FIG. In addition, the anti-reflection column 22 is the body 1
It may be provided over the entire vertical length of 0, or may be provided with a length limited to the height range in which the wave S acts.

As shown in FIG. 2B, the anti-reflection column 22 having a substantially triangular shape has a protruding portion 22b having the same width as the side wall 20 and extending forward at the rear end, as shown in FIG. Output 22
The front end of b is a sharpened portion 25 with an inclined surface 22a toward the outside of the bay.
May be formed.

Further, the inside of the antireflection column 22 may be solid or hollow.
The anti-reflection column 22 may be formed integrally with the skeleton at the time of manufacturing the skeleton 10, or as shown in FIG.
After manufacturing 0, the antireflection column 22 may be fixed to the body 10 via the bolts 23 and the like. As shown by the broken line in FIG. 1, the antireflection column 22 is also provided between the body 10 of the adjacent seawater AC breakwater caisson 100.

Further, the angle of the anti-reflection column 22 between the inclined surfaces can be set to any size (FIG. 2A).
(B) shows a case of about 60 °), and the inclined surface 22a may be a linear surface as shown in FIGS. 2A and 2B or a curved surface.

The operation of the above embodiment will be described below.

As shown in FIGS. 1 and 2A and 2B,
On the upright wall surface 21 of the outer side front part of the side wall 20 provided for forming the water conduit 13 in the skeleton 10, a horizontal cross-sectional shape including a sharp part 25 with a wide rear part and a reduced left and right width toward the front side is provided. When the anti-reflection column 22 having a substantially triangular shape is provided, the front portion of the side wall 20 is tapered toward the outside of the bay, and therefore the wave S traveling from the outside of the bay toward the seawater AC breakwater caisson 100 is reflected as shown in FIG. Inclined surface 22 of prevention column 22
By being guided by a, the diversion P is made to the left and right, and the headrace 1
I will go to 3. Therefore, the reflected wave due to the upright wall surface 21 on the front surface of the side wall 20 does not occur.

Further, the wave that is shunted to the left and right by the antireflection column 22 and heads for the water conduit 13 will collide with the wave that rides directly toward the seawater introduction slope 12 from the lateral direction, so that the seawater is introduced. The waves riding on the slope 12 are disturbed, and the wave-dissipating action of the seawater introduction slope 12 is also enhanced.

Therefore, according to the seawater AC breakwater caisson 100 shown in FIGS. 1 and 2A and 2B, by providing the headrace 13 having the slope 12 for introducing seawater, the waves S outside the bay enter the bay. In the structure that prevents the spread of the water and effectively exchanges the seawater outside the bay with the seawater inside the bay, the wave reflectance can be effectively reduced, and the wave disappeared by the seawater introduction slope 12. The wave action is also enhanced.

FIG. 4 is a front view of another example of the embodiment of the present invention applied to the seawater AC breakwater caisson of FIGS. 8 and 9 as seen from the outside of the bay, and FIG. 5A shows a part of FIG. It is a top view cut horizontally.

As shown in FIGS. 4 and 5 (A), the water conduit 1
In the seawater AC breakwater caisson 100 provided with No. 3, the width dimension decreases toward the outside of the bay at the outside of the bay of the side wall 20 provided to form the water conduit 13 in the skeleton 10, and the sharpened portion 25 is provided. The inclined surface 24 is formed so as to be formed.

In addition to the shape shown in FIG. 5A, the shape shown in FIG.
As shown in FIG. 1, the side wall 2 of the body 10 forming the water conduit 13
0 is provided so as to project further to the front side than the bay outside front part of the skeleton 10, and the inclined surface 24 whose left and right width dimensions decrease toward the bay outside as described above at the front part of the projecting side wall 20.
The shape may be provided with the sharpened portion 25 by forming the.

The angle between the inclined surfaces 24 may be any size (approximately 60 in FIGS. 5A and 5B).
In addition, the inclined surface 24 may be a linear surface as shown in FIGS. 5A and 5B or a curved surface.

As shown in FIGS. 4 and 5A and 5B,
At the front part of the side wall 20 on the outer side of the bay, a sharpened portion 25 having a taper shape toward the outer side of the bay is formed by an inclined surface 24 whose width dimension decreases toward the outer side of the bay. The wave S traveling toward 100 is shunted to the left and right by being guided to the inclined surface 24 as shown in FIG.
After that, it goes to the water conduit 13. Therefore, in FIG.
The reflected wave due to the upright wall surface 21 on the front surface of the side wall 20 in FIG.

Further, the wave that is shunted to the left and right by the inclined surface 24 formed on the outer side of the bay of the side wall 20 and heads for the headrace 13 is lateral to the wave that rides directly on the slope 12 for introducing seawater. Since the collision occurs, the waves riding on the seawater introduction slope 12 are disturbed, and the wave-dissipating action of the seawater introduction slope 12 is also enhanced.

Therefore, according to the seawater AC breakwater caisson 100 shown in FIGS. 4 and 5A and 5B, the provision of the headrace 13 having the seawater introduction slope 12 allows the wave S outside the bay to enter the bay. In the structure that prevents the spread of the water and effectively exchanges the seawater outside the bay with the seawater inside the bay, the wave reflectance can be effectively reduced, and the wave disappeared by the seawater introduction slope 12. The wave action is also enhanced.

The present invention is not limited to the above embodiment, but is also applicable to the vertical surface plate 2a formed between the slit openings 7 of the bay outer plate 2 in the conventional seawater AC breakwater caisson 1 shown in FIG. Needless to say, the shape of the anti-reflection column and the shape of the inclined surface provided on the side wall can be variously changed, and various changes can be made without departing from the scope of the present invention.

[0053]

In the seawater AC breakwater caisson according to the first and second aspects, the rear wall is wide and the left and right width decreases toward the front side on the upright wall surface outside the bay between the headraces formed in the skeleton. Since an anti-reflection column with a horizontal cross-section having a substantially triangular shape is fixed, the front part outside the bay between the headraces is tapered toward the outside of the bay, so that the waves traveling toward the seawater AC breakwater caisson are sharpened. Is divided into left and right by the inclined surface of the anti-reflection column and heads for the headrace, which has the effect of not generating reflected waves due to the upright wall surface outside the bay between the headraces.

In the seawater AC breakwater caisson of the third aspect, an inclined surface having sharpened portions is formed at the front part outside the bay between the headraces formed in the skeleton so that the lateral width decreases toward the outside of the bay. Since it was formed, the front part outside the bay between the headraces has a tapered shape toward the outside of the bay, so that the waves heading to the seawater AC breakwater caisson are diverted to the left and right by the inclined surface and head inside the headrace. It has the effect of not generating reflected waves due to the upright wall surface on the outer front of the bay between the headraces.

Further, in the seawater AC breakwater caisson according to claim 4, the water conduit provided in the skeleton has a climbing apex at the upper part of the inner rear part of the bay, and descends from the top of the riding aboard toward the outer part of the bay. Since there is a seawater introduction slope that is inclined at a slope, the waves shunted to the left and right by the slope will collide from the lateral direction against the waves that are dissipated by riding toward the seawater introduction slope. In addition, since the wave introduced into the body is further disturbed, there is an effect that the wave-dissipating action of the body is enhanced.

[Brief description of drawings]

FIG. 1 is an oblique front view of an example of the form of a seawater AC breakwater caisson according to the present invention as seen from the outside of the bay.

2A is a plan view showing a part of FIG. 1 cut horizontally, and FIG. 2B is a plan view showing an example of the shape of an antireflection column different from FIG.

FIG. 3 is a perspective view showing a method of fixing an antireflection column to a body.

FIG. 4 is a front view of another example of the form of the seawater AC breakwater caisson of the present invention, as seen from the outside of the bay.

5A is a plan view showing a part of FIG. 4 cut horizontally, and FIG. 5B shows an example of the shape of the side wall and the inclined surface different from the case of FIG. It is a top view.

FIG. 6 is a schematic plan view showing an example of a harbor.

FIG. 7 is a perspective view showing an example of a conventional seawater AC breakwater caisson.

FIG. 8 is a cut-away side view of a seawater AC breakwater caisson having a structure substantially similar to the configuration previously filed by the applicant of the present patent application.

9 is a front view of the seawater AC breakwater caisson of FIG. 8 viewed from the outside of the bay.

10 is a plan view showing a part of FIG. 8 by cutting it horizontally.

[Explanation of symbols]

10 body 11 Overpass top 12 Seawater introduction slope 13 Headrace 20 Side wall 21 Upright wall 22 Anti-reflection column 22a inclined surface 24 inclined surface 25 pointed part 100 Seawater AC Breakwater Caisson

Claims (4)

[Claims] 1. A seawater AC breakwater caisson having a seawater headrace on its skeleton, and a seawater surmounting apex at the rear of the headrace, which is an upright wall surface outside the bay between the headraces formed on the skeleton. The seawater AC breakwater caisson is characterized in that the anti-reflective pillar with a sharpened portion is fixed to the front with a wide rear portion and a reduced width on the left and right sides toward the front side. 2. The seawater AC breakwater caisson as claimed in claim 1, wherein the antireflection column has a substantially horizontal cross-sectional shape of a triangle. 3. A seawater AC breakwater caisson having a seawater headrace on the skeleton and a seawater surmounting apex at the rear of the headrace, wherein the bay outside front part between the headraces formed on the skeleton is provided with a bay. A seawater AC breakwater caisson characterized in that the width dimension on the left and right decreases toward the outside to form an inclined surface with a sharpened portion. 4. The water conduit provided in the skeleton has a climbing apex at the upper part of the rear inner part of the bay, and a seawater introduction slope inclined from the climbing apex toward the outer front part of the bay at a downward slope. The seawater AC breakwater caisson according to claim 1.