JP2524503B2 - Membrane structure submerged dike and its construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an open sea area of a breakwater that protects various facilities such as a harbor and a nuclear power plant, or a sea area that forms an artificial inland sea with high calmness. It is related to a suitable submerged dike used by being sunk in, etc., and in particular, it has a film having flexibility, and a film structure submerged dike adapted to attenuate waves by utilizing the motion of this film, and its It is about the construction method.

[Conventional technology]

FIG. 5 shows a membrane structure submerged dike that the applicant has already proposed and developed. In the figure, the reference numeral 1 as a whole is a membrane structure submerged dike (hereinafter abbreviated as "membrane submerged dike"), and this membrane submerged dike 1 is the seabed of the sea area in order to suppress the wave of a certain desired sea area. It is built on S.

The membrane submerged dike 1 is composed of a concrete bed (foundation structure) 2 installed in a substantially buried state on the seabed S, and a bag structure 3 installed on the concrete bed 2.
The bag structure 3 is composed of a flexible film body 4, and includes a bottom film 4a laid on the concrete bed 2 and an upper surface film 4b forming the upper surface of the bag structure 3. ,
A side wall film 4c provided between the bottom film 4a and the top film 4b.
And consists of. The bag structure 3 is in a liquid-tight state, and the inside thereof is filled with water 5, earth and sand 6, or air as shown in FIG. In the state in which the water 5 and the earth and sand 6 are filled, the bag structure 3 has a shape in which the upper surface film 4b is stretched in an arc shape as shown in the figure and forms a part of a cylindrical body. The film body 4 is made of, for example, rubber or cloth-rubber, and as shown in FIG. 7, the end portions of the respective film bodies 4 (bottom film 4a, top film 4b, sidewall film 4c) are While overlapping and joining, the end part of the ring fitting 7
It is attached to the concrete bed 2 by interposing the ring fitting 7 on the anchor 8 and tightening it on the anchor 8. The upper surface film 4b and the side wall film 4c are joined to each other by a means such as bolting through a joining metal fitting (not shown) or vulcanization and curing and then adhering.

The operation of the above-mentioned membrane submerged bank 1 will be described below in comparison with a rigid structure submerged bank that has been widely used in the past.

In FIG. 8, the reference numeral 20 indicates a conventional rigid structure submerged dike (hereinafter referred to as "rigid submerged dike") constructed from concrete or the like.
It is). The rigid submerged dike 20 breaks a wave (incident wave W ₁ ) on the shallow top of the rigid submerged dike 20 as shown in FIG. The energy loss of the wave is aimed to disappear by continuing on the wide tip of the wave. Therefore, in order to expect the wave-dissipating effect of this rigid submerged dike 20, the top of the rigid submerged dike 20 should be located near the water surface (to reduce the water depth above the top of the dike) and to increase the width of the top (cross section Need to be big).

On the other hand, as shown in FIG. 9, the submerged bank (membrane structure submerged bank) 1 attenuates the energy of the wave due to the deformation of the bag structure 3, and the wave generated by the movement of the bag 3 is further reduced. causing interference; (radiation wave radiated wave) W ₂ with respect to the incident wave W _1, it is intended to attenuate the incident wave W ₁ itself.

The applicant has conducted the following simulation in the above-mentioned membrane submerged dike 1 and rigid submerged dike 20, that is, a cross section required to reduce the transmitted wave height of a wave with an incident wave height of 2 m and an incident wavelength of 100 m to 1 m or less in a sea area with a water depth of 20 m. In order to obtain the same wave-dissipation performance, it has been found that the membrane submerged dike 1 has a cross section of 1/8 or less of the rigid subdivided dike 20.

[Problems to be solved by the invention]

By the way, the above-mentioned membrane submerged dam 1 exerts excellent wave-dissipating ability as described above, and also leisure (sea bathing, boating,
Etc.) It has an excellent effect that it is less dangerous when used in the marine area, but there were the following points to be improved.

That is, since the three-dimensional shape of the bag structure 3 is to be maintained by the earth and sand 6 and the water 5 with which the bag structure 3 is filled, the bag structure 3 is required to have high watertightness. There was a concern that the work of joining No. 4 and the connection between the members would become strict and the construction cost would increase. Moreover, the construction of the bag structure 3, that is, the operation of joining the membrane bodies 4 is performed at the construction site, and the work efficiency is low due to the difficulty of the above-mentioned water tightness being required for the underwater work. It was Further, if the bag structure 3 is damaged even at one place, water 5, earth and sand 6, air, etc. leaks to the outside, and it becomes impossible to maintain its three-dimensional shape, and it cannot function as a submerged dike. There was a fear.

The present invention has been made in view of the above circumstances, and it is needless to say that it is possible to obtain the same action as that of the above-mentioned conventional membrane structure submerged dike, because the rigor of construction can be relaxed and long-term use is possible. It is an object of the present invention to provide a membrane structure submerged dike that can avoid the effects of damage and the like as much as possible, and a method for constructing the same.

[Means for solving problems]

A first aspect of the invention is a membrane structure submerged dike configured to include a membrane body and a base structure that is formed on a water bottom and fixes the membrane body, wherein the membrane body has a pair of opposite ends thereof. A portion is fixed on the basic structure in a relaxed state, and a plurality of bags which are inflated by filling with a fluid are provided between the membrane and the basic structure. The present invention further includes that the bag body is integrally formed with the film body on the lower surface of the film body.

A second aspect of the present invention is a membrane structure including a film body having a bag body filled with a fluid such as water on one surface, and a basic structure formed on the water bottom to fix the film body. A method of constructing a submerged embankment, which comprises the step of installing the foundation structure in water, producing the film body in a long strip on land, and winding the film body formed in the strip into a roll shape. A step of rotating to form a film body roll, a step of fixing the tip end of the film body in a roll shape to one end of the base structure installed in water, and a tip end being fixed to the base structure A step of moving the formed film body roll toward the other end of the basic structure while drawing out the film body forming the film body roll; A step of fixing to the end, and a step of fixing the both ends to the base structure and the film body Fixing and disconnecting the bets is the opposite ends in the relaxed state which is characterized in that it consists of a step of injecting a fluid such as water to the bag provided in the film body fixed to the foundation structure.

[Action]

The wave-dissipating principle of the membrane structure submerged dike according to the present invention is the same as the wave-dissipation principle of the conventional membrane structure submerged dike described above. That is, the energy of the wave can be attenuated by the deformation of the submerged bank, and the radiation wave generated by the film body can be interfered with the incident wave by the movement of the submerged bank to attenuate the incident wave.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is for explaining a membrane-structured submerged dike according to the first aspect of the present invention. In FIG. It is called).
The symbol S indicates the seabed.

The membrane submerged dike 10 is configured to have a concrete bed (foundational structure) 2 installed in a substantially buried state on the seabed S, and a membrane body 11 mounted on the concrete bed 2.

The concrete bed 2 is firmly installed on the seabed S so that it does not move even under the influence of ocean currents and waves, like a general underwater foundation. In this embodiment, the concrete bed 2 has a rectangular plate shape. The film body 11 is also rectangular and is provided on the upper surface of the concrete bed 2 so as to cover almost the entire surface of the concrete bed 2. The membrane body 11 is fixed to the concrete bed 2 only at one end of the rectangle, that is, a pair of opposing sides, and is fixed in a relaxed state, that is, in a state where the concrete bed 2 is loosened. Has been done. The fixing of the membrane body 11 to the concrete bed 2 is performed by moving the end portion of the membrane body 11 upward by, for example, a ring fitting 7 in the same manner as that shown and described for the conventional membrane structure submerged dike in FIG. Is pressed against the concrete bed 2. In this case, the ring fitting 7 is attached to the anchor 8 embedded in the concrete bed 2.

A plurality of bags 12 filled with water are provided between the membrane body 11 and the concrete bed 2. In this case, as shown in FIG. 1, the bag body 12 is formed by arranging in parallel from the one end fixed to the concrete bed 2 of the membrane body 11 to the other end, and in this embodiment, this bag body is formed. 12, the film body as shown in FIG.
The lower surface of 11 is integrally formed with the film body 11. For example, as shown in FIG. 2 (a), the bag body 12 is formed by bending a flexible flexible member 13 formed in a band shape in a U shape in the width direction thereof, and further opening the upper opening end thereof on the back surface of the film body 11. It is folded back so as to be in close contact with the (lower surface), and a contact plate or the like (not shown) as a sealing means is interposed between the folded back portion 13a and the membrane body 11, and the membrane body 11 and the folded back portion 13a are bolted together. Nut 1
Two flexible flexible members 13 that are tightened with 4 or the like, or as shown in FIG.
Are joined together at their width direction edges to form a V-shape, and are folded back so that their upper open ends are in close contact with the lower surface of the film body 11, and the folded-back portion 13a and the lower surface of the film body 11 are It is composed by joining. The flexible rubber member 13 is preferably made of the same rubber as the film body 11,
The joining of the flexible flexible members 13 or the joining of the flexible flexible member 13 and the film body 11 according to FIG. 7B is performed by vulcanizing and curing these joints and then adhering them. Further, both side openings of the flexible flexible member 13 which is formed in a U shape or a V shape as described above and whose upper opening end is joined to the film body 11 are also formed by means such as adhesion after vulcanization and curing. The bag 12 is closed so that the bag 12 constitutes a closed space. The film body 11 is such that a plurality of bag bodies 12 arranged in parallel are filled with the maximum amount of water in the center part of the film body 11 and the filling amount is sequentially reduced from the center part toward both ends. By doing so, it is stretched in an arc shape.

Next, the operation of the membrane structure submerged dike 10 configured as described above will be described.

When the plurality of bag bodies 12 are filled with water as described above, the membrane body 11 is stretched in an arc shape as shown in FIG. 1 because the membrane body 11 is fixed to the concrete bed 2 in a relaxed state. It becomes a state. When the wave reaches the membrane submerged dike 10, the membrane body 11 receives the force of the wave, and the membrane body 11 receives the force.
The bag body 12 interposed between the concrete bed 2 and the concrete bed 2 is deformed. The energy of the wave is attenuated by deforming the bag 12. Then, the bag 12 deformed by the waves moves to return to the steady state, that is, the stable state as shown in FIG. This movement of the bag body 12 in turn moves (vibrates) the membrane body 11, and this movement causes a radiation wave to be generated on the water surface. This radiation wave interferes with the incident wave, and the incident wave is attenuated.

Further, the membrane submerged dike 1 does not have a three-dimensional shape by connecting the membrane bodies 11 like the one shown in FIG. 5, but has a three-dimensional shape with a plurality of bag bodies 12. Therefore, in the film body 11, it is not necessary to consider joining with another film body or ensuring liquid tightness, and the construction can be simplified and the cost can be reduced. Regarding the bag body 12, of course, it is necessary to consider liquid tightness, but by making it a divided structure, each of them can be made small and can be manufactured on land, and it can be made highly reliable. . Further, the three-dimensional shape of the membrane submerged bank 10 is to be held by a plurality of bag bodies 12, but since these bag bodies 12 are provided in an independent state, by any chance, Even if one of the bags 12 is damaged, the membrane submarine 10 rarely loses its overall function. Further, the movement of the film body 11, that is, the deformation of the film body 11 due to the wave or the subsequent return is all determined by the relationship with the expansion force applied to the film body 11 by the bag body 12, and thus the bag body 12 It is also possible to adjust the wave-dissipating effect by controlling the tension of the film body 11 by adjusting the amount of water filled into the film. And these membrane submerged dikes
In addition to the peculiar effects of 10, in this embodiment, the bag body 12 is integrally formed with the membrane body 11, so that the construction can be carried out very efficiently.

In the above embodiment, the plurality of bag bodies 12 arranged in parallel have the same size, and the film body 11 is stretched in an arc shape depending on the filling amount of water. The film body 11 may be formed into an arc shape by forming the maximum size in the central part of the film 11 and decreasing the size from the central part toward both ends.

Next, an embodiment of a method for constructing a membrane structure submerged dam according to the second invention will be described with reference to FIG. The second invention is a method for constructing the above-mentioned membrane submerged bank 10 shown as an embodiment of the first invention, and the above-mentioned membrane submerged bank 10 is constructed as follows.

The concrete bed 2 is formed by a conventional method for constructing an underwater foundation, that is, by pouring concrete in water or burying it after making it on land.

The film body 11 is created on land in advance. At that time, the film body 11 is formed in a long strip shape, and the bag body 12 is attached to one surface thereof by the above-mentioned means. After that, the long strip-shaped film body 11 provided with the bag body 12 is wound into a fabric shape to form a film body roll 15.

After the installation of the concrete bed 2 in water and the production of the membrane roll 15 are completed, the membrane roll 15 is transported to above the concrete bed 2 by sea transportation.

Then, the film roll 15 is suspended in water by, for example, a winch 17 or the like provided on the work boat 16 and is suspended to an attached position.

Next, the end portion (tip portion) of the film roll 15 is fixed to one end of the concrete bed 2. At this time, the bag body 12 is positioned on the lower surface, that is, on the concrete bed 2 side. The means for fixing the film body 11 drawn from the film body roll 15 to the concrete bed 2 is the ring contact metal fitting 7 and the anchor 8 as described above. This work is performed underwater.

When the fixing of the tip of the membrane roll 15 to one end of the concrete bed 2 is completed, the membrane roll 15 is moved toward the other end of the concrete bed 2 with the tip thereof fixed. This movement is performed by towing (bottoming) from above the water by the work boat 16 or the like. Since the tip of the membrane roll 15 is fixed, the membrane 11 is fed out from the membrane roll 15 due to this movement, whereby the upper surface of the concrete bed 2 is covered with the membrane 11. .

When the above state is reached, this time, the central portion of the membrane body 11 covering the upper surface of the concrete bed 2 is lifted by the winch 17, and in this state, the membrane body 11 is attached to the other end side of the concrete bed 2. The part which was located is fixed there.
The reason why the central portion of the film body 11 is lifted is to allow the film body 11 to have slack.

Next, the portion of the membrane body 11 fixed to the concrete bed 2 is separated from the membrane body roll 15, and then water (seawater) is injected into the bag body 12 provided on the membrane body 11. The filling of water is performed by the pump 18 mounted on the work boat 16 or the like.

The bag body 12 expands due to the filling of water and pushes the membrane body 11 upward in an arc to complete the membrane submerged ridge 10 as shown in FIG.

According to the above method, the film body 11 and the bag body that are responsible for the wave canceling action.
Since the bag 12, especially the bag 12, is manufactured on land, the product quality such as liquid-tightness can be improved, and the reliability of the entire membrane submerged dike 10 can be greatly improved. Further, since the film body 11 is formed in a roll shape and is laid while unrolling the film body roll 15, the length of the film body 11 can be changed on the spot depending on the size of the concrete bed 2 on site. It can be set freely. The width of a normal submerged dike is 10
-30m, length 50-150m is common,
In many cases, a plurality of membrane submerged dikes 10 as shown in the figure are arranged side by side in the lateral direction, and when the membrane body 11 is laid many times in this way, the membrane body roll is used. Very efficient construction can be expected because construction can be done sequentially while shifting 15 from the completed location to the next location.

In both the first invention and the second invention, in the embodiment, the bag body 12 is a plurality of closed spaces formed in parallel from one end to the other end of the film body 11. The shape and the like are not limited to those of the present embodiment, and may have any configuration as long as the film body 11 can be stretched in a substantially arc shape by expansion. Further, the membrane body 11 and the concrete bed (foundation structure) 2 are rectangular in this embodiment.
Also, the shape of the concrete bed 2 is not limited to the rectangular shape, and the film body 11 may be circular, for example. Further, the bag body 12 is filled with water (seawater) in the embodiment, but the bag body 12 is not limited to water and may be filled with air or the like.

〔The invention's effect〕

As described above, according to the membrane structure submerged embankment according to the first aspect of the present invention, due to the energy attenuation action of the wave due to the deformation of the membrane body and the interference action of the radiation wave due to the restoring force of the membrane body to the incident wave, Of course, it is possible to exert a very remarkable wave-dissipating action, but its three-dimensional shape does not form a bag structure by laminating membranes like a conventional membrane structure submerged dike, but a plurality of Since it is formed by the bag body divided into, the complicated process such as joining the film bodies can be eliminated and the liquid tightness can be easily secured, increasing the reliability of the product and reducing the cost. can do. Further, since the film body is stretched by a plurality of bag bodies, the wave-dissipating action can be adjusted by adjusting the amount of fluid filled in the bag body. Even if one of them is damaged, the entire function is not lost, and the repair can be easily performed, which is an excellent effect.

Further, according to the method for constructing a membrane structure submerged dam according to the second aspect of the invention, since the membrane body having the bag body is manufactured on land, the quality and reliability of the membrane body and the bag body having the wave-dissipating function are improved. It can greatly improve the sex. Further, since the membrane is formed in a roll shape and is laid while sending out the membrane roll during the construction of the submerged levee, the length of the membrane, that is, the width of the submerged ridge is determined by the size of the concrete bed on site. Of course, it can be freely set on the spot depending on the situation.
Since the number of the above-mentioned membrane rolls can be sequentially changed from the completed position to the lateral direction and installed, the length of the membrane structure submerged dike can be adjusted in any way, and extremely efficient construction can be desired. , And the like have excellent effects.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a membrane structure submerged embankment according to the first invention, and is an overall perspective view showing the membrane structure submerged embankment installed at the bottom of the water, and FIG. a) and (b) are both partial front sectional views of the film body showing the formation state of the bag according to the embodiment of the first invention,
FIG. 3 is for explaining an embodiment of a method for constructing a membrane structure submerged ridge according to the second invention, and is a side view showing the process of constructing the membrane structure submerged ridge according to one embodiment of the first invention, FIG. 4 is an overall perspective view showing a long membrane-structured submerged structure constructed by arranging the membrane-structured submerged structures shown as an example, and FIG. 5 is a conventional view previously proposed and developed by the present applicants. FIG. 6 is an overall perspective view showing the membrane structure submerged dike, FIG. 6 is a side sectional view schematically showing the conventional membrane structure submerged dike, and FIG. 7 is a conventional membrane structure submerged dike and the first invention of the present invention. FIG. 8 is a side cross-sectional view showing a part of a conventional membrane structure submerged bank, for explaining the attachment state of the membrane body constituting the membrane structure submerged bank to a base structure. This is for explaining the wave-dissipating principle of the rigid structure submersible, and FIGS. 2 (a) and 2 (b) are side cross-sectional views showing the rigid structure submersible installed in water. FIG. 9 is a side view showing the wave-dissipating principle of a conventional membrane-structured submerged dike and the membrane-structured subdivision according to the first aspect of the present invention, showing a submerged membrane-structured dike along with waves. is there. 2 …… Concrete bed (base structure), 3 …… Bag structure, 10 …… Membrane structure subbank, 11 …… Membrane, 12 …… Bag, 15
...... Membrane roll, 20 ...... Rigid structure submerged dike, S ...... sea floor (water bottom), W ₁ …… Injection wave, W ₂ …… Radiation wave.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yutaka Katsura 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Tadashi Ono 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Incorporated company (72) Inventor Seiji Ichii 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (56) Reference JP-A-60-62927 (JP, A) JP-A-54-155631 (JP, A)

Claims (3)

(57) [Claims] 1. A membrane structure submerged embankment comprising a membrane body and a basic structure formed on a water bottom for fixing the membrane body, wherein the membrane body has a pair of opposite end portions. Is fixed on the basic structure in a relaxed state, and between the membrane and the basic structure there are provided a plurality of bags which are inflated by filling with a fluid. Membrane structure submerged dam. 2. The membrane structure submerged embankment according to claim 1, wherein the bag body is formed integrally with the film body on the lower surface of the film body. 3. A method for constructing a membrane structure submerged dam, comprising a membrane body having a bag body filled with a fluid such as water on one surface, and a foundation structure formed on the bottom of the water for fixing the membrane body. Then, the step of installing the basic structure in water, and on the land, to produce the film body in a long strip shape, the film body formed in the strip shape is wound into a roll shape to form a film body roll. A step of forming, a step of fixing the tip end of the roll-shaped film body to one end of the foundation structure installed in water, and a membrane roll having the tip end fixed to the foundation structure A step of moving the film body constituting the film body roll toward the other end of the basic structure, and a step of fixing the drawn film body to the other end of the basic structure in a relaxed state. , Separate the membrane body and the membrane body roll, both ends of which are fixed to the foundation structure And a step of injecting a fluid such as water into the bag body provided on the membrane body whose both ends are fixed to the foundation structure in a relaxed state. .