JPH0544481B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for absorbing and dissipating waves and a wave absorbing and dissipating block.

BACKGROUND TECHNOLOGY Tetrapod (registered trademark) is commonly used as a conventional wave absorbing and dissipating block. It consists of a star-shaped concrete block with four protrusions forming an angle of 120 degrees with each other, and the embankment body is constructed by stacking multiple blocks.

Problems to be Solved by the Invention However, in such conventional blocks, when waves collide with the blocks, more energy is absorbed and the waves are dissipated, but along with this, wave splash is generated, and this wave is dissipated. The problem is that the droplets can reach the land. Furthermore, the conventional blocks described above have the problem that the flow of water is inhibited, resulting in stagnation and the organic matter is likely to rot.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve these problems and provide a wave absorption/dissipation method and a wave absorption/dissipation block that can prevent the generation of wave splash and allow water to flow sufficiently. .

Means for Solving the Problems In order to solve the above-mentioned problems, the wave absorption and wave dissipation method of the present invention includes a suction port on the outside of the bay, a suction port formed on the inside of the bay from the suction port, and A small diameter part is formed to dissipate waves, and a part is formed on the inner side of the bay and has a larger diameter than this small diameter part. A through-hole with a large diameter portion having a volume necessary for exhibiting a water retarding function that performs a wave-dissipating action by It is formed so as to penetrate through the hole, and waves are propagated inside the through hole.

In addition, the wave absorbing and dissipating block of the present invention is arranged in a horizontal direction from the outside of the bay to the inside of the bay, and the entire length of this block is extended from the outside of the bay to the bay. A through hole penetrating inward is formed in a straight line, and this through hole is formed with a suction port on the outside of the bay, and on the inside of the bay with respect to this suction port, and is formed with a smaller diameter than this suction port. There is a small diameter part for wave dissipation, and it is formed on the inside of the bay and has a larger diameter than this small diameter part, and the wave is dissipated by the generation of vortices by waves and the collision of waves with the inner surface. The large diameter portion has a volume necessary for exhibiting the water repelling function.

Effect According to such a configuration, waves propagating from the outside of the bay toward the inside of the bay are guided from the suction port of the through hole to the small diameter section, and then propagated from the small diameter section to the large diameter section. Then, the waves are easily guided to the small diameter part by the action of the suction port, and are guided to the large diameter part while receiving a wave-dissipating effect by colliding with the inner surface of the small diameter part, and are transferred from the small diameter part to the large diameter part. Due to the increase in the cross-sectional area of the passage and the water repelling action based on the volume of the large diameter portion, energy is absorbed and reliable wave dissipation is performed. Wave dissipation is also achieved by colliding with the inner surface of the large diameter portion. According to this, the waves do not collide with the rigid body, but are dissipated while passing through the through hole, so that generation of wave splash can be effectively prevented. Further, as the waves pass through the through hole, a water flow is generated inside the through hole, so that stagnation can be prevented from occurring.

Embodiment FIG. 1 shows a schematic cross-sectional structure of an embodiment of a wave absorbing and dissipating block 1A based on the present invention. Here, 2 is a block, which is made of columnar concrete. A cast iron pipe 3 extending along the length of the block 2 is embedded inside the block 2, and a through hole 4 is formed by the cast iron pipe 3.

For example, as shown in FIG. 2, a large number of blocks 2 are piled up in the sea to form a breakwater 5A as a breakwater body.In this breakwater 5A, each block 2 extends from the outside of the bay 6 to the inside of the bay 7. placed horizontally towards the In FIG. 1, the through hole 4 formed by the cast iron pipe 3 has a bellmouth-shaped suction port 9 that opens at the outer end surface 8 of the block 2. As shown in FIG. In addition, the suction port 9
A small diameter portion 10 smaller in diameter than the suction port 9 is formed over a certain length in a portion of the cast iron pipe 3 on the inner side of the bay. A large-diameter portion 11 is formed in a portion of the cast iron pipe 3 on the inner side of the bay than the small-diameter portion 10, which has a larger diameter than the small-diameter portion 10 and has a sufficient volume necessary to exhibit a water repelling function. The small diameter portion 10 and the large diameter portion 11 are connected to each other via a connecting portion 12, and this connecting portion 12 is formed in a hemispherical shape whose diameter gradually increases from the small diameter portion 10 to the large diameter portion 11. has been done.

The wave dissipating block 1A shown in FIG.
It is configured to have mirror symmetry at the center of
The part of the cast iron pipe 3 on the inside of the bay from the large diameter part 12 includes a second connection part 13 similar to the outside of the bay, a second small diameter part 14, and an end face 1 on the inside of the bay of the block 2.
A discharge port 16 opening at 5 is formed.

The wave dissipating block 1A can be divided into a plurality of parts in the length direction, and the one shown in FIG.
A split structure is used. 17 is the divided part, and the cast iron pipes 3 in this divided part 17 are
They are connected to each other using union joints. By dividing the cast iron pipe 3 in the length direction in this manner, each divided piece can have a structure suitable for demolding in centrifugal casting. In addition, in Figure 2,
18 is the foundation installed on the seabed, 19 is the breakwater 5A
This is an upper part for forming the upper surface 20 of.

FIG. 3 shows a schematic cross-sectional structure of another embodiment of the wave absorbing and dissipating block 1B according to the present invention. In this embodiment, the through hole 4 formed by the cast iron pipe 3 is composed of a suction port 9, a small diameter part 10, and a large diameter part 11, and does not have a mirror-symmetrical structure as shown in FIG. Large diameter part 1
The bay inner end 21 of block 1 is the bay inner end surface 1 of block 2.
It is configured to open at 5.

FIG. 4 shows the detailed structure of the wave absorbing and dissipating block 1B whose schematic cross-sectional structure is shown in FIG. 2. As shown in FIG. 4, the concrete block 2 is formed to have a rectangular cross section, and four side surfaces 22, 23, 24, and 25 appear on its outer surface. A plurality of convex portions 26 each having a constant length and a constant height are formed on one side surface 22 at constant distances in the length direction of the block 2 . Each convex portion 26 has a width of the side surface 22 (i.e.,
It is formed over the entire length of one side of the rectangle. A concave portion 27 corresponding to the convex portion 26 is formed on the side surface 24 located on the opposite side to the side surface 22 on which the convex portion 26 is formed, and when a pair of wave-dissipating blocks 1B are arranged side by side, The wave dissipating block 1B is constructed so that the convex portion 26 and the concave portion 27 fit into each other.

In addition, in the above, the convex portion 26 is provided on one side surface 22.
and a recess 27 on the other side 24.
As shown in FIG. 5, a convex portion 26 is formed on each of the pair of adjacent side surfaces 22 and 23, and a recessed portion 27 is formed on each of the other pair of adjacent side surfaces 24 and 25. You may.

FIG. 6 shows the cross-sectional structure of a breakwater 5B as a breakwater body constructed by stacking a large number of wave-dissipating blocks 1B in the sea. When stacking, the recesses 2 of adjacent wave-dissipating blocks 1B
7 and the convex portion 26 are fitted together to firmly connect each wave dissipating block 1B to each other. Also,
The wave-dissipating blocks 1B are stacked so as to form an upward slope from the outer side 6 of the bay to the inner side 7 of the bay. In addition, the breakwater 5A shown in the above-mentioned FIG.
Also, the structure in which the concave portion 27 and the convex portion 26 fit together and the inclined structure of the wave dissipating block 1A are adopted.

FIG. 7 is a view showing the inside or outside side of the breakwater 5 having a configuration similar to that shown in FIG. 2 or FIG. 6. As shown in the figure, the wave absorbing and dissipating blocks 1 are arranged and stacked to form a diamond shape when viewed from the end. With such a stacked structure, the vertical stress transmitted to the lower wave-dissipating block 1 based on the weight of the upper wave-dissipating block 1 can be dispersed laterally, and the buoyant force received from waves can be reduced. You can get a large drag force even if you use it.

Between the plurality of wave-dissipating blocks 1 arranged and stacked in a diamond shape in this way and the base part 18, and between these wave-dissipating blocks 1 and the upper part 19,
As shown in FIG. 8, a spacer 28 having a triangular cross section is provided. This spacer 28 has a convex portion 26 or a concave portion 2 of the block 2.
A concave portion or a convex portion that fits into the spacer 8 is formed, and FIG. 8 illustrates a spacer 28 in which only the concave portion 27 is formed.

In such a configuration, for example, when waves 31 advance toward the breakwater 5A from the outer side 6 of the breakwater 5A shown in FIG.
The wave collides with the outer end face 8 of the bay, and energy is absorbed and dissipated by this collision. The remainder of the wave 31 reaches the suction port 9 of the through hole 4, as shown in FIG. 1, and is guided from the suction port 9 to the small diameter portion 10. At this time, since the suction port 9 is formed in a bell mouth shape, the waves 31 can be effectively introduced into the small diameter portion 10. In the small diameter part 10, waves 31
By colliding with the inner surface of 0, the energy is absorbed and subjected to wave-dissipating action, and then guided to the large diameter portion 11 via the connecting portion 12.

Then, due to the increase in the cross-sectional area of the passage from the small diameter portion 10 to the large diameter portion 11, the fluid energy held by the waves 31 is absorbed and wave dissipation is performed. Furthermore, waves 31 generate vortices 32 in the large diameter portion 11, and energy is consumed to generate these vortices 32, thereby dissipating waves. Furthermore, waves are also dissipated by collision with the inner surface of the large diameter portion 11. Thereafter, the waves 31 are guided by the second connecting portion 13 and reach the second small diameter portion 14, and are dissipated by colliding with the inner surface of the second small diameter portion 14. At this time, since the second connecting portion 13 is formed in a hemispherical shape, the wave 31 to the small diameter portion
The introduction is carried out well. Finally, the waves 31 are guided from the discharge port 16 to the inside of the bay 7, where they are also dissipated due to the increase in the cross-sectional area of the passage, and are in a state where they retain almost no energy.

In the case of the wave absorbing and dissipating block 1B shown in FIG. 3, the waves 31 reaching the large diameter portion 11 of the through hole 4 are
From this large diameter portion 11, the waves are immediately guided to the inner side of the bay 7, where the waves are dissipated due to the increase in the cross-sectional area of the passage.

In this way, the waves 31 are dissipated while passing through the through hole 4, so that it is possible to dissipate the waves while preventing the generation of wave splash.

In addition, as the waves 31 pass through the through hole 4, a water flow is generated inside the through hole 4, so water constantly flows inside the through hole 4, causing stagnation. is prevented. especially,
As shown in Fig. 2 and Fig. 6, the wave dissipating block 1A,
By inclining 1B to form a downward slope toward the outer side 6 of the bay, water in the through hole 4 can be reliably discharged to the outer side 6 of the bay. Therefore, water can be exchanged between the inner side of the bay 7 and the outer side of the bay 6, which was impossible with a conventional simple breakwater.

In addition, since the water in the through hole 4 can be made to flow, it is possible to prevent the occurrence of a situation where foreign matter remains in the through hole 4 and rots. In addition,
In order to prevent foreign matter from entering the inside of the through hole 4, a screen, a net, etc. may be attached to the suction port 9 and the discharge port 16.

Note that, as shown in FIG. 4, it is preferable that the diameter D of the suction port 9 of the through hole 4 and the diameter d of the large diameter portion 11 are made the same, and in this way, the block 2 does not have to have a divided structure as described above. When configured as one,
There is an advantage that concrete can be placed while the cast iron pipe 3 is maintained in a horizontal position. Also,
Since the through hole 4 is formed of the cast iron pipe 3, the wave dissipating block 1 can be easily formed by pouring concrete around the cast iron pipe 3, and the block 2 can be reinforced by the cast iron pipe 3. I can do it.

Effects of the Invention As described above, according to the present invention, waves are dissipated by propagating them inside the through hole, which has a small diameter portion and a large diameter portion that exhibits a water repelling function. It is possible to dissipate waves without generating splashes, and since the through holes are formed in a straight line from the outside of the bay to the inside of the bay, penetrating the entire embankment body, the inside of the Good wave dissipation can be achieved while preventing stagnation and ensuring water flow.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a schematic configuration of an embodiment of the wave-absorbing and dissipating block according to the present invention, FIG. 2 is a cross-sectional view showing a breakwater constructed using the wave-dissipating block shown in FIG. 1, and FIG. 4 is a sectional view showing a schematic configuration of another embodiment of the wave absorbing and dissipating block according to the present invention, FIG. 4 is a detailed view of the block shown in FIG. 3, and FIG. An end view showing an example, FIG. 6 is a sectional view showing a breakwater constructed from the blocks shown in FIG. 3, and FIG. 7 is a side view of the breakwater.
FIG. 8 is a diagram showing a spacer used in constructing the breakwater shown in FIG. 7. 2... Block, 4... Through hole, 6... Bay outside, 7... Bay inside, 9... Suction port, 10... Small diameter part, 11... Large diameter part.

Claims (1)

[Claims] 1. A suction port on the outside of the bay, a small-diameter part for wave dissipation that is formed on the inside of the bay and has a smaller diameter than this suction port, and a smaller diameter part than this small-diameter part. It is formed on the inside of the bay and has a larger diameter than this small diameter part, and is necessary to exert a water retarding function that performs wave dissipation by the generation of vortices by waves and the collision of waves with the inner surface. A through hole having a large diameter portion with a volume is formed so as to penetrate the entire embankment body in a straight line in the horizontal direction from the outside of the bay to the inside of the bay, and waves are propagated inside this through hole. A method for absorbing waves and dissipating waves. 2. A through-hole is inserted in a straight line from the outside of the bay to the inside of the bay through the entire length of the columnar block, which is arranged horizontally from the outside of the bay to the inside of the bay and can be stacked to form an embankment body. This through hole is formed in the shape of a suction port on the outside of the bay, a small diameter part for wave dissipation that is formed on the inside of the bay and has a smaller diameter than this suction port, and It is formed on the inner side of the bay and has a larger diameter than the small diameter part, and has a water retarding function that dissipates waves by generating vortices due to waves and colliding with the inner surface of the waves. A wave absorbing wave dissipating block characterized in that it has a large diameter portion having a volume necessary for.