JP2520182B2 - Water-permeable case - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to water permeable caissons.

2. Description of the Related Art Conventionally, in harbor music and the like, a breakwater is constructed by a caisson or the like, and a closed water area is formed surrounded by the breakwater. However, in this closed water area, the flowability of seawater becomes poor and the seawater in the port becomes polluted.In recent years, therefore, this caisson was provided with a communication passage that laterally connects the outside of the bay and the inside of the bay. It has been proposed to prevent water pollution in water bodies.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, as described above, in a caisson provided with a communication passage that laterally connects the outer side of the bay and the inner side of the bay, sludge and the like accumulated on the sea bottom move through the communication passage. And
This may lead to enlargement of the sludge area.

The present invention solves the above problems, and an object of the present invention is to provide a water-permeable caisson that does not cause enlargement of sludge areas.

Means for Solving the Problems In order to solve the above problems, the present invention, in a caisson placed in water, provided with a passage portion that penetrates in the wave transmission direction, if the heights of the openings of the passage portions are different from each other. Shime,
The openings in the high position face the outside of the bay, and the openings in the low position face the inside of the bay.

Action With the above configuration, one opening is arranged at a low position and the other opening is arranged at a high position, and the water-permeable caisson is arranged with the opening at the high position facing the outside of the bay, which is the area on the sludge spot side. By doing so, the water passes through the passage portion between the regions before and after the passage portion due to the waves, while the sludge does not flow into the passage portion, whereby expansion of the sludge portion is prevented.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 (a) and 1 (b), a caisson 1 made of concrete has a passage portion 2 penetrating obliquely in the front-back direction.
Are provided side by side, one opening 3 is formed at a high position, and the other opening 4 is formed at a low position.
As shown in FIG. 2, the water-permeable caisson 5 has, as shown in FIG. 2, a boundary portion of the area where the sludge a is accumulated on the seabed.
The opening 3 located at a high position is arranged to face the wave transmission force x (for example, the opening 3 is directed toward the outside of the bay) so that the opening 3 is directed toward the outside of the sled a side.

In the above configuration, the seawater in the middle layer or the upper layer outside the bay flows into the lower layer inside the bay via the passage 2 due to the wave transmission force x. Therefore, while the seawater circulates well between the inside and the outside of the bay, the inflow of sludge a into the passage 2 is prevented because the opening 3 on the outside of the bay where the sludge a is accumulated is at a high position. . As a result, the sludge a portion does not expand.

Further, in the above-mentioned embodiment, the example of preventing the expansion of the sludge portion is shown, but it can also be used for preventing the outflow of fine sand. That is, it is possible to prevent the outflow of the fine sand by directing the opening 3 at a high position toward the side where the fine sand is present and by arranging the opening 3 facing the wave x.

Further, the water permeable caisson 5 can be used for improving water quality. That is, by directing the opening 3 at the high position to the outside of the bay, the water with a large oxygen content in the upper and middle layers of the sea flows in as an ocean current and flows out from the opening 4 at the lower position. The water quality is improved by mixing the water with a large amount of oxygen with the water with a small amount of oxygen near the seabed. Further, by directing the opening 4 at a lower position toward the side where the bottom is eutrophication, the eutrophication water b near the bottom is supplied to the upper layer and the middle layer through the passage 2 by the wave flow. , This also improves the water quality.

FIGS. 3 (a) and 3 (b) show another embodiment. In this embodiment, a front wall 12 and a rear wall 13 extending upward from the front end and the rear end of a concrete bottom portion 11 are erected. It is set up. Then, a plurality of passage portions 14 made of cast iron pipe or the like are arranged so as to extend across the front surface wall 12 and the rear surface wall 13, and the front side opening portion 15 of the passage portion 14 is located at a high position.
The rear opening 16 of the 14 is arranged at a low position. With this water permeable caisson 17, the same operational effects as those of the water permeable caisson 5 of the above embodiment can be obtained.

It should be noted that the lengths and inclination angles of the passage portions 2 and 14 in both of the above embodiments may be appropriately changed depending on the application.

Further, FIGS. 4 (a) and 4 (b) show a separate embodiment, in which the water-permeable caisson 21 has a plurality of openings 23 provided at a high position on the front surface of concrete caissons 22A, 22B in two steps. A plurality of openings 24 are provided at a high position on the rear surface, and the corresponding openings 23, 24 are communicated with each other by a communication space 25 as a passage extending vertically and longitudinally. Adjacent communication space portions 25 are communicated with each other by lateral communication passages 26A, 26B formed in the caisson 22A, 22B of each stage so as to extend in the lateral direction. Although not shown, the lateral end of the water permeable caisson 21 is closed by a lid member or the like so that seawater or the like flows in and out only through the front opening 23 and the rear opening 24. With this type of water permeable caisson 21, the same operational effects as those of the water permeable caissons 5 and 17 of the above embodiment can be obtained.

Further, the water permeable caisson 5, 17, 21 of each embodiment may be used in combination.

EFFECTS OF THE INVENTION As described above, according to the present invention, the heights of the openings of the passage portions are made different from each other, and the openings at the high positions are directed to the outside of the bay and the openings at the low positions are directed to the inside of the bay. Since the sleds and fine sand are located outside the bay, the opening at a high position outside the bay is placed so that the sludge and fine sand can be prevented from flowing into the bay. We can supply eutrophic water to the upper and middle layers by arranging the low-level opening toward the eutrophic water side near the seafloor in the upper and middle layers. The quality of water that cannot be supplied to the lower part can be improved.

[Brief description of drawings]

1 (a) and 1 (b) are a cross-sectional view and a front view showing a water-permeable caisson according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing an example of use of the water-permeable caisson, and FIG. FIGS. 4A and 4B are cross-sectional views and front views showing a water-permeable caisson according to another embodiment of the present invention, and FIGS. 4A and 4B are cross-sectional views showing another embodiment of the present invention. It is a front view. 1,22A, 22B …… Caison, 2,14 …… Corridor, 3,4,15,16,2
3,24 …… Aperture, 5,17,21 …… Water-permeable caisson, 12 ……
Front wall, 13 ... rear wall, 25 ... communication space (passage),
26A, 26B ... Horizontal passage.

 ─────────────────────────────────────────────────── ─── Continued Front Page (56) References JP-A-63-70706 (JP, A) JP-A-64-36809 (JP, A)

Claims (1)

(57) [Claims] 1. A caisson placed in water is provided with a passage portion penetrating in the direction of wave transmission, the openings of the passage portions are made different in height, and the opening portion at a high position is directed to the outside of the bay. , A water-permeable caisson characterized by arranging the lower opening towards the inside of the bay.