JPS6314125B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a concrete block for a seawall and a seawall using the same, and more specifically, to a concrete block for a seawall and a seawall using the same. The present invention relates to a concrete block for a seawall for constructing a permanent seawall, which prevents scouring and suction phenomena in front of the bank body by bringing the flow of reflected waves close to a steady flow, and a seawall using the concrete block.

Accidents frequently occur in which seawalls, which have traditionally been built on sandy beaches to prevent coastal erosion, are damaged. This is caused by strong reflected waves scouring the front of the embankment foundation, and interstitial water within the embankment colliding with the concrete of the embankment. Together with the strong reflected waves, the water is sucked out to the front of the embankment through a small gap in the embankment, accompanied by soil and sand. It is empirically known that this is due to the suction phenomenon.

Therefore, a method of covering the front wall with glue was adopted, which can withstand some amount of suction and can stand on its own and continue to function even if some soil flows out from the back. The butt wall type has a wide bottom plate and a fairly large slope of about 1:0.5 in order to withstand scouring in front of the levee body. However, in this buttress-type seawall, the energy of the reflecting plate is not attenuated very much, causing the sandy beach to recede significantly, and the front surface is scoured and sucked out by reflected waves, which still causes breakage and collapse accidents.

Although all of these seawalls are made of strong concrete, the inventors believe that they do not have strong walls to protect against the waves that hit the coast with a large amount of energy, and instead attenuate the wave energy. In particular, we focused on the fact that a seawall that weakens the energy of reflected waves and allows free flow of pore water at the back of the dam body is stronger as a result. The present invention was completed by covering the embankment body with a concrete block having a large number of water reservoirs that allow water to be released slowly until the waves arrive.

That is, the present invention aims to provide a permanent seawall by breaking waves and turning reflected waves into a gentle steady flow to prevent front surface scouring. A concrete block for a seawall in which a wave-breaking plate planted in the bottom plate and one wall plate perpendicular to the bottom plate and the wave-breaking plate are integrally cast, and a large number of such concrete blocks for a seawall. This is a seawall with a wave-breaking plate facing toward the ocean and a bottom plate placed in close contact with the slope.

The concrete block according to the present invention requires a strong bottom plate, a wave breaking plate, and a wall plate to be cast as one unit. The bottom plate is flat to ensure stable placement on the slope, and the wave-breaking plate is designed to withstand wave energy.
A sturdy one with a slight slope towards the bottom plate is preferable. The wall board is installed perpendicularly to the bottom plate, and it is desirable that the upper end surfaces of the bottom plate and the wave-breaking plate become horizontal when installed on a slope. As a result, a water storage container is formed by the bottom plate, the wave breaking plate, and the wall plate, and becomes a container for storing seawater, but because one wall plate is missing, the water cannot be stored for a long time, and at the same time as the waves recede, one of the bottom plates It gradually flows out from the edge, and the energy of the reflected waves is significantly attenuated by the wave-breaking effect of the wave-breaking plate, resulting in a gentle flow similar to a steady stream, and the water storage tank is empty before the next wave hits. It can store seawater for the next time.

Hereinafter, the present invention will be described in detail by way of examples with reference to the drawings.

FIG. 1 is a perspective view of a concrete block. 1 is a bottom plate, 2 is a wave breaking plate planted in the bottom plate 1, a part of the bottom face 3 extends outward from the bottom plate, and forms a recess 5 with a first end 4 of the bottom plate. 6 is a curved wave breaking surface, which receives waves and attenuates energy. A wall plate 7 is formed integrally with the wave breaking plate 2 at a third end 8 adjacent to the first end 4 of the bottom plate 1. Reference numeral 9 denotes a fitting portion provided at the second end 10 of the bottom plate, which is longer than the outwardly extending portion of the bottom surface of the wave breaking plate 2 and has a size that allows it to fit into the recess 5 of another block of the same shape. It is. Therefore, the wall plate 7 is provided deeper than the insertion part 9. There is no limit to the shape of the wall plate, but the surface that slopes from the bottom plate surface toward the upper end of the wave breaking plate 2, preferably formed by the upper end of the wave breaking plate 2 and the upper end of the wall plate 7, is suitable for this block. It is desirable that it be horizontal when installed on a surface. Bottom plate 1, wave breaking plate 2 and wall plate 7
As a result, a concave-shaped water reservoir 11 is formed. 12
is a drainage channel forming part formed by extending the fourth end 13 of the bottom plate outward from the wave breaking plate, and forms a drainage channel through which the seawater temporarily stored in the water storage shell 11 flows out before the next wave. do.

FIG. 2 shows another embodiment in which the drainage channel forming portion 12 is provided outside the wall plate 7 and the wave breaking surface 6 is made flat. In any of the above embodiments, the slope is completely covered by the bottom plate, but since the bottom plates are not bonded to each other, the gap water behind the embankment body can freely pass through. Insertion part 9 of another block
It has the advantage that the bottom plate is hard to shift because it is inserted and combined.

FIG. 3 is a layout diagram of a seawall using the concrete blocks of the present invention, viewed perpendicular to the slope, and FIG. 4 is a sectional view taken along the line -- in FIG. 14 is the slope, 15
is a foot protection work. Waves crashing from the ocean first collide with the breaking wave surface 6a and break mechanically, and a portion of the seawater is stored in the water reservoir 11a. The remaining waves further collide with the wave breaking surface 6b of the upper block and are broken, and a portion is stored in the water storage bowl 11b. As the seawater rises to the upper level, the amount of seawater decreases significantly and the wave energy also attenuates. When the waves recede, the seawater stored in the water storage bowl 11 flows down from the side where the wall plate 7 is not provided, passes through the drainage channel 16, enters the lower water storage bowl 11, and further flows down the drainage channel 16. In this way, the reflected waves cannot flow down all at once, so they are attenuated and become close to a steady flow, so there is no scouring of the front surface of the levee body, and there is no suction from the back surface of the levee body. Even if it were to be sucked out, the bank protection block-covered slope according to the present invention has the flexibility to be transformed into a slightly depressed slope, so the bank body would not be destroyed.

In this embodiment, the drainage channel 16 is formed on the bottom plate, but in some cases, the drainage channel forming part 12 may not be provided on the concrete blocks themselves, and the concrete blocks may be arranged with the drainage channel intervals maintained. Good too. The drainage channel must be wide enough not to be clogged by shellfish, etc., and is 10 to 40 cm, preferably 15 to 30 cm. Further, when the blocks of the present invention are arranged on a slope, in this embodiment, the upper and lower stages are staggered, but it is not necessarily necessary to stagger them, and the drainage channels may run perpendicularly to each other.

As described above, according to the present invention, the amount and energy of wave seawater rising up the embankment body is drastically reduced by using the concrete block water storage container and the wave breaking plate that cover the slope, and not only the energy of the reflected waves is small, but also the energy of the reflected waves is small. The flow is close to a steady flow, and a permanent seawall can be obtained without the risk of scouring the front of the embankment body.

[Brief explanation of the drawing]

The drawings show embodiments of the invention, FIGS. 1 and 2.
The figure is a perspective view of concrete blocks for seawall, No. 3.
The figure is a layout diagram of the blocks viewed from the vertical direction of the slope, and FIG. 4 is a sectional view taken along the line -- in FIG. In the figure, 1 is the bottom plate, 2 is the wave breaking plate, 4 is the first end, 5 is the recess, 6 is the wave breaking surface, 7 is the wall plate, 9 is the inset part, 10 is the second end, and 11 is the water storage 14 is the slope, 15 is the foot protection work, and 16 is the drainage canal.

Claims (1)

[Scope of Claims] 1. Concrete for a seawall, in which a flat bottom plate, a wave-breaking plate planted on the bottom plate, and one wall plate perpendicular to the bottom plate and the wave-breaking plate are integrally cast. Block. 2. A flat bottom plate, a wave-breaking plate planted on a first end of the bottom plate, a part of the bottom extending outward from the bottom plate, and forming a recess on the bottom surface, and a first end of the bottom plate. At a second end opposite to the first end, a wall plate perpendicular to the bottom plate and the wave breaking plate is integrally formed, leaving a fitting portion shaped to fit into the recess formed in the first end. Concrete blocks for the seawall being poured. 3 A large number of concrete blocks for seawalls, each of which is integrally cast with a flat bottom plate, a wave-breaking plate installed on the bottom plate, and a wall plate perpendicular to the bottom plate and the wave-breaking plate, are A seawall is constructed by placing the plates facing the ocean and the bottom plate in close contact with the slope. 4. A seawall according to claim 3, wherein a large number of concrete blocks for seawall are arranged with drainage channels formed between wave-breaking plates.