JPH01111907A - Sea dyke with box-shaped blocks and inhabitable to littoral creatures - Google Patents

Abstract

PURPOSE:To enable littoral creatures such as shellfishes, seaweeds, etc., to inhabit in concrete blocks to be used for the sea dyke construction, by stagnating part of washing sea water in the block of which two faces are constituted of a shallow water-stopping barrier and a wave-breaking board having a drainage. CONSTITUTION:A concrete block is formed with a bottom board 1, a wave- breaking board 2 having a drainage-forming portion 3, a side wall 4, a water- stopping barrier 5, much lower in height than the side wall 4, and a back wall 6. A plurality of the box-shaped blocks are heaped in tiers to build a sea dyke with the wave-breaking board 2 facing frontward. The wave-breaking board 2 reduces wave energy and let the backwash flow through the drainage, preventing scouring at the dyke body. As the sea water remains in the block even at low tide, the blocks can be made inhabitable to littoral creatures.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention temporarily stores seawater that washes up on the coast, and provides a shallower water-stopping frame to the box-shaped block that prevents free passage of seawater when the waves recede. In addition to constructing a seawall using concrete blocks, a part of seawater remains even at low tide, and box-shaped blocks are used to construct a permanent seawall that is suitable for the habitat of coastal organisms. Concerning seawalls.

[Conventional technology]

There have been many accidents in which seawalls, which have traditionally been built on sandy beaches to prevent coastal erosion, are damaged.

This is due to strong reflected waves scouring the front of the embankment foundation, and strong reflected waves that flow down the concrete surface of the embankment as jets, sucking out pore water inside the embankment from small gaps or cracks in the embankment, accompanied by earth and sand. It is empirically known that this is due to the so-called suction phenomenon.

The present inventor believes that conventional seawalls are all made of strong concrete, but they do not have strong walls to deal with the waves that hit the coast with a large amount of energy, and instead attenuate the wave energy, especially the reflected waves. Focusing on the fact that a seawall that approaches a steady flow to weaken the energy of scouring at the front of the levee body and allows free flow of pore water at the back of the levee body is ultimately stronger, the publication of Special Publication No. 63-14125 ,
JP 63-14126, JP 60-168805
No. 60-168806 proposes covering the embankment body with a large number of concrete blocks having wave-breaking plates that temporarily pool the seawater that washes up with the waves and slowly release it until the next wave. did.

[Technical problem to be solved by the invention]

However, natural beaches, especially rocky areas, have deep areas where some seawater remains even when the tide is low, and these areas contain shellfish,
It is home to seaweed and other coastal creatures and serves as a hiding place for small fish. The seawall proposed by the present inventor has a seawall effect and an effect of preventing scouring in front of the bank body, and is designed to resemble a natural rocky area as much as possible, and is suitable for the habitat of coastal organisms during low tide. They also researched seawalls in which seawater remains and completed the present invention.

[Means of problem solving]

The present invention provides a box-shaped block that stores a portion of the washed-up seawater without letting it flow out until the next high tide by providing a shallow water-stop frame on a concrete block having a wave breaking plate and a drainage channel that constitute a sea wall. According to the present invention, it is possible to provide a park-like element that allows people to enjoy the seawall at low tide.

The block according to the present invention has a strong bottom plate, a rear wall, a wave breaking plate, and a water stop frame that are cast integrally with the strong bottom plate. The bottom plate is sturdy enough to reliably cover the ocean side portion of the sea wall along with the rear wall. The rear wall is installed perpendicularly from the entire length of the rear end of the bottom plate, and is able to withstand the impact from the back. In order to further enhance the water storage effect and obtain a sturdy concrete block, the side wall may be provided integrally with the wave breaking plate and the bottom plate.

A part of the wave-breaking plate must be missing, leaving a shallow water stop frame, and this missing part will serve as a drainage channel for reflected waves when a seawall is formed. There are no particular restrictions on the location where drainage canals are provided, but
One end of the front surface of the bottom plate is convenient for manufacturing. The drainage channel must have a sufficient width so as not to be blocked or narrowed by the proliferation of shellfish, seaweeds, etc., and should be at least 70 mm, preferably 100 to 200 ++v+, and in some cases wider.

The side wall connecting the wave breaking plate and the rear wall is provided on one side of the box-shaped block as shown in FIG. 1, and only the water stop frame is provided on the other side. In addition, when side walls are not provided, as shown in FIG. 2, a water stop frame is provided to shallowly surround the bottom plate in areas other than the rear wall of the bottom plate and the wave breaking plate. In other words, the water stop frame is installed shallowly at the open end of the bottom plate where no wall is provided, shallowly blocks the part of the bottom plate where water flows down, and the height of the water stop frame is set at the water storage area for coastal living creatures. This is the depth of

[Effect]

When such blocks are arranged, a drainage channel having the same width as the drainage channel forming portion of the block is formed. The crashing waves pass over the breaking plates one after another (from below), consuming energy and reducing the amount of seawater, and when being pulled back, they are blocked by the breaking plates and flow down one after another through a narrow drainage channel.Therefore, the waves break due to the breaking plates. Coupled with this effect, the energy of the reflected waves is significantly attenuated, and the flow becomes gentle like a steady stream, and before the next wave hits, it drains away, leaving some of the stored seawater behind.
You can prepare for the next wave. Here, by storing a portion of seawater, it is possible to provide a habitat for coastal organisms.

〔Example〕

FIGS. 1 and 2 are perspective views of a box-shaped block, and FIG. 3 is a cross-sectional view of a seawall using the same. 1 is a bottom plate, 2 is a wave breaking plate planted on the bottom plate 1 leaving a drainage channel forming part 3, and 4 is a side wall provided at the end of the wave breaking plate 2 on the opposite side from the drainage channel forming part 3. Reference numeral 5 denotes a water stop frame which is much lower than the side wall 4, and is provided in the open part of the wave breaking plate 2 on the opposite side to the side wall 4. 6 is the rear wall.

As shown in Fig. 1, when the slope is covered in a step-like manner, the outlet for wave seawater is the front part of the wave-breaking plate 2 where the water-stop frame is provided, and this is shallowly covered (by blocking it with the water-stop frame 5). Seawater is stored. 7 is a seawater storage part. Therefore, the bottom plate 1 is surrounded on all sides, and seawater is stored up to the height of the water stop frame 5 at low tide.

FIG. 2 shows another embodiment of the box-shaped block. In this embodiment, side walls 4 are not provided. Therefore, although not visible in the drawing, the water stop frame 5 is also provided at the open end where the side wall 4 in FIG. 2 is provided, so the water stop frame 5 is divided into two parts on the bottom plate 1. Reference numeral 8 denotes a platform, which can be used as a safe foothold when one wants to walk from a lower block to an upper block, or vice versa, when a seawall is constructed using the blocks of this embodiment.

FIG. 3 is a perspective view of a seawall constructed using the box-shaped blocks shown in FIG. 2. In construction, the box-shaped blocks are arranged side by side in close contact with each other, as shown in FIG. When exposed to waves, the wave-breaking plate 2 attenuates the energy of the waves, and the temporary water storage section 9 stores the waves to reduce the amount of seawater. The undertow is blocked by the wave breaking plate 2 and flows out from the drainage channel 3, approaching a steady flow and preventing scouring of the front surface of the embankment foundation. However, the seawater remaining in the water storage part 7 in the water stop frame 5 cannot flow out, and seawater remains in this part even at low tide, and can be used as a habitat for coastal creatures. 10 is foot protection work.

Furthermore, since the upper ends of the wave-breaking plate and the rear wall are horizontal, and a platform 8 is provided in the middle, it is possible to walk safely inside the seawall at low tide. Furthermore, seawater remains in the water storage section 7, providing a habitat for coastal organisms and allowing the area to be used as a coastal park.

〔Effect of the invention〕

Like this (by this invention, seawater remains shallow even at low tide,
In addition to being suitable for habitat for coastal organisms, the amount and energy of seawater rising up the levee body is drastically reduced, and not only is the energy of reflected waves small, but the flow is close to a steady flow, and the front surface of the levee body is scoured. A permanent sea wall can be obtained without the risk of damage.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIGS. 1 and 2 are perspective views of a box-shaped block, and FIG. 3 is a sectional view of a seawall. In the drawing, 1 is a bottom plate, 2 is a wave breaking plate, 3 is a drainage channel forming part, 4 is a side wall,
5 is a water stop frame, 6 is a rear wall, 7 is a water storage section, 8 is a platform, 9 is a temporary water storage section, and 10 is a foot protection work. Patent applicant: Nippon Sohan Co., Ltd. Agent Patent attorney: Sadako Suzuki

Claims (2)

[Claims] (1) A concrete block having a bottom plate and a rear wall shaped to completely cover the ocean side of a stepped seawall, which blocks the free passage of seawater when waves recede. A wave-breaking plate is installed integrally from the bottom plate, leaving a drainage channel forming part, and a water stop frame is installed on the bottom plate to store some of the seawater that has washed up on it, without allowing it to flow out even after the tide has receded. A box-shaped block featuring (2) A concrete block having a bottom plate and a rear wall shaped to completely cover the ocean side of a stepped seawall, which block the free passage of seawater when waves recede. The wave breaking plate is integrally planted from the bottom plate leaving a drainage channel forming part, and a box-shaped block is installed on the bottom plate with a water stop frame that stores some of the washed-up seawater without letting it flow out. This is a seawall for coastal living creatures, which is made by arranging the wave-breaking plates facing the ocean side, leaving a drainage channel between the wave-breaking plates, and covering the stepped ocean-side slope with the bottom plate and the rear wall.