JPH0562165B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to 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, energy is absorbed and waves are dissipated. The problem is that it reaches 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 An object of the present invention is to solve these problems and provide a wave absorbing and wave dissipating block that can prevent the generation of wave splash and can allow water to flow sufficiently.

Means for Solving the Problems In order to solve the above problems, the present invention is arranged in a lateral direction from the outside of the bay to the inside of the bay, and
A through hole is formed in a columnar block that can be stacked to form an embankment body, and a through hole is formed from the outside of the bay to the inside of the bay. A structure having a bench lily part with a smaller cross-sectional area, a throat part formed at the rear end of this bench lily part, and a retarding part formed on the inner side of the bay than this throat part and having a larger cross-sectional area than this throat part. That is.

Effect According to this 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 throat section via the bench lily section, and the waves generated at the throat section on the upstream and downstream sides. The energy is absorbed and dissipated by the pressure difference. Furthermore, energy is also absorbed and dissipated due to the increase in the cross-sectional area of the passage when moving from the throat section to the retarding section and the collision with the inner surface of the through hole. According to this, the waves do not collide with the rigid body, but are dissipated while passing through the through hole, so generation of wave splash can be suppressed. Further, as the waves pass through the through hole, a water flow is generated inside the through hole, thereby preventing the occurrence of stagnation.

Embodiment FIG. 1 shows a schematic cross-sectional structure of a wave absorbing and dissipating block according to the present invention. Here 1
is a block, made of concrete in the shape of a square prism. A cast iron pipe 2 extending along the length of the block 1 is embedded inside the block 1, and a through hole 3 is formed by the cast iron pipe 2. As shown in FIG. 3, a large number of blocks 1 are piled up in the sea to construct an embankment body 4 such as a breakwater. In this embankment body 4,
Each block 1 is arranged laterally from the outer side 5 of the bay to the inner side 6 of the bay.

In FIG. 1, the through hole 3 formed by the cast iron pipe 2 has a bellmouth-shaped suction port 8 that opens at the outer end surface 7 of the block 1. As shown in FIG. On the inside of the bay from this suction port 8, there is a bench lily portion 9 whose diameter gradually decreases from the outside of the bay toward the inside of the bay.
A throat portion 10 is formed at the rear end of the bench lily portion 9. Bench lily part 9
is the angle α that its inner surface makes with the axis 11 of block 1
It is formed into a cone shape so that the angle ranges from 0 to 45 degrees. A retarding portion 12 having a larger diameter than the throat portion 10 is formed in a portion of the cast iron pipe 2 on the inner side of the bay than the throat portion 10 . The throat portion 10 and the water retardation portion 12 are connected via a connecting portion 13, and this connecting portion 13 is formed in a cone shape as shown in the figure or a hemispherical shape. In FIG. 1, the angle β between the inner surface of the connecting portion 13 and the axis 11 can be set appropriately.

The wave absorbing and dissipating block in FIG. 1 is configured to have mirror symmetry at the center of the retarding section 12, and a second section of the cast iron pipe 2 on the inner side of the bay than the retarding section 12 has a second Connection part 1
4. A discharge port 18 that opens at the second throat portion 15, the second bench lily portion 16, and the inner end surface 17 of the block 1 is formed.

In the above, the cast iron pipe 2 has a circular cross section, but a square cross section or other pipes may also be used. Further, although the block 1 having a square cross section is illustrated in FIG. 2, it may have another cross-sectional shape. Furthermore, the back side of the water retarding section 12 may be opened directly into the bay inner end surface 17 without providing the second throat section 15 or the like.

FIG. 3 shows the cross-sectional structure of a breakwater body 4 constructed by stacking a plurality of wave absorbing and dissipating blocks described above vertically and horizontally in the sea. Here, 19 is a concrete base installed on the seabed, and a concrete foundation block 20 is stacked on top of this base 19, and a plurality of blocks 1 are placed on top of this foundation block 20.
It is composed of a stack of.

Block 1 is a wave 21 advancing from the outside of the bay 5.
The height 23 of the part protruding upward from the sea surface 22 should be two-thirds of the wave height h.
degree and the height of the part submerged into the sea from sea level 22
It is preferable that 24 be approximately the same as the wave height h.

In such a configuration, the embankment body 4 shown in FIG.
When a wave 21 advances toward this embankment body 4 from the outer side 5 of the bay, a part of this wave 21 collides with the outer end face 7 of the block 1, and energy is absorbed by this collision and the wave is dissipated. be done. Here, in the embankment body 4 shown in FIG.
A simple concrete foundation block 20 is installed in the area that is not affected by water, and no wave dissipating block is installed in this area. By doing so, the cost can be reduced since the through hole 3 is not formed. The stacking height of block 1 mentioned above is
The above-mentioned values are set depending on the fluctuation range of the tide level and the expected maximum wave height.

Of the waves 21, those that do not collide with the end face 7 of the block 1 reach the retarding part 12 from the suction port 8 in FIG. Then, due to the pressure difference between the outside of the bay and the inside of the bay that occurs in the throat portion 10, that energy is absorbed and dissipated. Furthermore, energy is absorbed and dissipated due to the increase in the passage cross-sectional area when moving from the throat portion 10 to the retarding portion 12 and the collision with the inner surface of the through hole 3.

Thereafter, the waves are further dissipated by passing through the second connection part 14, the second throat part 15, and the second bench lily part 16. and outlet 1
8 to the inside of the bay 6, where it is also dissipated due to the increase in the cross-sectional area of the passage and becomes in a state where it retains almost no energy.

In this way, since the waves 21 are dissipated while passing through the through hole 3, it is possible to dissipate the waves while preventing the generation of splashes. Moreover, the wave 21 is
As the water passes through the through hole 3, a water flow is generated inside the through hole 3, so that stagnation in the embankment body 4 is prevented.

Effects of the Invention As described above, according to the present invention, wave dissipation can be performed satisfactorily without generating wave splash and in a state where water flow is ensured.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the wave absorbing and dissipating block according to the present invention, FIG. 2 is a cross-sectional view taken from FIG. 1, and FIG. It is a sectional view showing the constructed embankment body. 1... Block, 3... Through hole, 4... Embankment body,
5... Outside the bay, 6... Inside the bay, 8... Suction port, 9
... Bench lily part, 10... Throat part, 12...
...Playing water club.

Claims (1)

[Claims] 1 A through-hole is formed in a columnar block that is arranged horizontally from the outside of the bay to the inside of the bay and can be stacked to form an embankment body, and this through-hole extends from the outside of the bay to the inside of the bay. An outer suction port, a bench lily portion whose cross-sectional area gradually decreases from this suction port toward the inside of the bay, a throat portion formed at the far end of this bench lily portion, and a throat portion formed on the inside of the bay from this throat portion. A wave-absorbing wave-dissipating block characterized by having a retarding section having a larger cross-sectional area than a throat section of a lever.