JP2736222B2 - Floating and sinking wave absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wave absorber for canceling a wave by floating on a water surface.
In detail, it is used to prevent floating mud generated during underwater construction such as dredging and landfill from flowing out of the construction area due to the effects of waves and spreading and contaminating fishing grounds. The present invention relates to a floating-sink type wave absorber that can be submerged in water.

[0002]

2. Description of the Related Art During underwater works such as dredging and landfill,
Floating mud is generated. If such floating mud or the like flows out and spreads out of the construction area due to the effect of the waves, the fishing ground may be polluted, and it is necessary to prevent such a situation. In addition, in the case of undersea construction, there is a problem that, when affected by waves, the construction period is prolonged due to a decrease in work efficiency and construction costs are increased. For this reason,
2. Description of the Related Art Conventionally, in underwater construction, wave countermeasures have been taken to suppress generation of waves in a construction area.

As a conventional countermeasure against waves, the following floating / sinking type wave absorber is known (see FIG. 4, FIG. 5, page 5 of Japanese Patent Application Laid-Open No. 60-175615). Referring to FIG. 5, according to the publication, the floating / sinking type wave absorber is provided with a first flexible tubular float 2A.
A second flexible tubular float 5A positioned in parallel with the first flexible tubular float 2A;
A, a flexible plate 3 integrally connected to 5A, a canvas 6 connected along a lower end of the first flexible tubular float 2A, and a lower end of the canvas 6 attached along the lower end of the canvas 6. And a plurality of weights 9.

According to the floating-sink type wave absorber of the above construction, the canvas 6
Thereby, the diffusion of floating mud and the like generated in the construction area can be suppressed. Further, in the same figure, the wave traveling in the direction of arrow C is eliminated by the first flexible tubular float 2A and the second flexible tubular float 5A, and the generation of waves in the work area can be suppressed.

[0005]

By the way, when a sea route is set near the place where the floating-sink type wave absorber is installed, or in the sea or lake where the scenery is important, even if the work is under construction, the work is actually performed. If not, the wave absorber is very obtrusive. Therefore, the floating-sink type wave absorber can be immersed in water except during actual work. That is, referring to FIG.
Settling floats 20, 21 are connected in a T-shape in the middle of 5A, and both floats 2A, 5A are connected by a conduit to an air supply / exhaust device on land.

Referring to FIG. 6, if the two floats 2A and 5A are evacuated at the required time, the two floats 2A and 5A are drawn into the water in a V-shape (see the upper left of page 3 of the publication). 13th line to the lower left second line). However, if the squat is settled as shown in FIG.
There is a case where the connecting portion C between the first and second floats 2A and 5A is extremely bent and damaged. In addition, in order to reliably sink the air into the floats 2A and 5A without generating an air reservoir, air must be exhausted from both sides of the floats 2A and 5A, which causes a problem that the apparatus becomes large-scale. There is also.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a floating-sink type wave absorber which can easily sink and float without damaging the wave absorber.

[0008]

According to a first aspect of the present invention, there is provided a floating / sinking type wave absorber which is flexible and has a long bag which floats on water by being filled with air. A canvas attached along the longitudinal direction of the bag body and provided with a weight at the lower end, and hanging down from the bag body into water to suppress water flow in the water under the influence of waves, and air for the bag body. An air supply / exhaust device that supplies or exhausts air when the air in the bag body is exhausted by the air supply / exhaust device,
In a floating-sinking type wave absorber including a bag and a forced sinking weight for forcibly sinking the canvas into the water, the forced sinking weight is provided at one longitudinal end of the bag, The air supply / exhaust device is characterized in that it is connected to the other longitudinal end of the bag.

The floating / sinking type wave absorber according to a second aspect of the present invention is the floating / sinking type wave absorber according to the first aspect, wherein the bags are arranged parallel to each other in a water surface direction while floating on the water. It is constituted by a pair of tubular members connected to each other, and the canvas is attached along a longitudinal direction of each of the pair of tubular members.

Further, the floating / sinking type wave absorber according to claim 3 comprises:
The floating / sinking type wave absorber according to claim 2, wherein a distance between the pair of tubular members is 5m or more. Further, the floating-sink type wave absorber according to claim 4 is the floating-sink type wave absorber according to claims 1 to 3, wherein the length from the upper end to the lower end of the canvas is 4 m or more. It is.

[0011]

According to the floating / sinking type wave absorber according to the first aspect, when air is supplied into the bag body by the air supply / exhaust device connected to the other end of the bag body, the bag body becomes a so-called float and floats on the water. Surface. A canvas is attached to the bag along the longitudinal direction, and since the canvas is provided with a weight, if the bag floats, the canvas hangs down from the bag into the water. I do. With this canvas, it is possible to prevent mud and the like generated in the water during the dredging work or the like from being diffused under the influence of waves and leaking from the inside of the construction area to the outside. Further, since the bag floating on the water cancels waves on the water surface, waves in the work area can be suppressed.

On the other hand, when the air in the bag body is exhausted by the air supply / exhaust device, the bag body contracts because it has flexibility, and its buoyancy decreases. In addition, since a weight for forced settlement is provided at one end in the longitudinal direction of the bag, the bag with reduced buoyancy sinks in water sequentially from one end where the weight for forced settlement is provided. I do. This allows
When the floating sinking body sinks in water, the bag is not bent extremely.

Further, according to the floating / sinking type wave absorber according to the second aspect, since the bag body is formed of a tubular member, the bag body can be easily manufactured and the air supply and exhaust can be performed smoothly. It is preferable because it can be used. Moreover, since the bag body is composed of a pair of tubular members arranged and connected in parallel with each other in the water surface direction, after the wave on the water surface is eliminated by one tubular member, the other tube is further removed. The wave can be eliminated by the shape member, and the wave can be eliminated more effectively. Further, since the canvas is attached to each of the pair of tubular members, it is possible to effectively suppress the flow of the water flow in the water due to the influence of the waves, and to more effectively prevent the diffusion of mud and the like. be able to.

In particular, according to the floating / sinking type wave absorber according to the third aspect, since the interval between the pair of tubular members is set to 5 m or more, the pair of tubular members simultaneously move up and down on the waves. Can be avoided. Because, from experience, the wavelength of the wave generated on the sea where this type of wave absorber is used is within 10 m, so if the interval between the pair of tubular members is set to one half or more of the wavelength, This is because even if one of the tubular members moves up and down on a wave, the other tubular member does not move up and down in conjunction with the one tubular member. Therefore, the water flow in the water can be suppressed by any one of the canvases, and the diffusion of mud or the like due to the effect of the waves can be surely prevented.

Further, according to the floating / sinking type wave absorber according to the fourth aspect, since the length from the upper end to the lower end of the canvas is set to 4 m or more, the wave energy due to the canvas is effectively attenuated. Can be. Because, the water particles inside the wave also have a rotational motion, and the motion of the water particles has, empirically, extended to a depth of about a half wavelength below the surface of the water. The velocity of the water particles is highest near the water surface, and decreases linearly as the water depth increases. Also, the energy of the waves is proportional to the square of the velocity of the water particles. Therefore, the length of the canvas is 4 m below the water surface.
If the wave length is set to 10 m, the canvas can affect 80% of the velocity distribution of water particles, assuming that the wavelength of the wave is up to 10 m. That is, if the length of the canvas is set to 4 m or more below the water surface, the canvas can affect about 96% or more of the wave energy. Therefore, it is possible to more effectively prevent the diffusion of mud and the like due to the influence of the waves.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a partially sectional exploded perspective view schematically showing a floating-sink type wave absorber according to one embodiment of the present invention. With reference to FIG. 1, this floating / sinking type wave absorber is installed on water to divide a construction area during underwater construction, and is a long bag that can be filled with air. 100, a canvas 200 attached to the bag 100, and a hose 300
Have an air supply / exhaust device (not shown) connected to the bag 100.

The bag 100 includes a pair of tubular members 110 and 120 arranged in parallel, a connecting member 130 for connecting the tubular members 110 and 120, and a forced subsidence provided at one end of each of the tubular members 110 and 120. Weight 140 is included. The tubular members 110 and 120 are made of a flexible material such as rubber and the like, and expand to form a columnar shape when filled with air, and shrink when air is removed from the inside. This tubular member 11
It is preferable that the outer diameter of 0,120 is set in the range of 300 mm to 700 mm, even when installed on the sea, because it is hardly affected by weight increase due to attached organisms. Further, by forming the bag-shaped member, the bag 100 can be easily manufactured, the manufacturing cost can be reduced, and the supply and exhaust of air into and from the tube-shaped members 110 and 120 can be performed smoothly. .

The materials constituting the tubular members 110 and 120 are not only rubber but also the tubular members 110 and 1.
As long as airtightness of the inside of the housing 20 can be ensured, a resin or the like can be used, or a cloth coated to ensure the airtightness of the inside can be used. The pair of tubular members 110 and 120 have a predetermined axial distance d in the water surface direction in an expanded state. In this embodiment, the distance d is set to 5 m. In addition,
The forced sinking weight 140 is made of a metal such as lead or iron.

The connecting member 130 is a sheet having flexibility. The connecting member 130 is made of the same material as that of the tubular members 110 and 120. Thus, the tubular member 11
If they are made of the same material as 0, 120, they can be formed integrally. However, the connecting member 13
It is also possible to form the tubular member 110 with a material different from that of the tubular members 110 and 120. In this case, the tubular members 110 and 120 and the connecting member 130 can be connected by an adhesive or another known method. it can.

The canvas 200 is a rectangular sheet-shaped member, and its upper side 220 is attached along the longitudinal direction of each of the tubular members 110 and 120. A weight 210 is provided on the lower side 230. In this embodiment, the weight 210 is made of a chain, but may be made of a known material such as lead or a concrete block that can be used as a weight. Further, the upper side 220 and the lower side 230 have a predetermined distance L, and are set to 4 m in this embodiment.

The air supply / exhaust device includes an air supply / exhaust unit and the hose 300. The air supply / exhaust section is installed at a predetermined position on land, and the air supply / exhaust section is connected to the tubular members 110 and 120 by the hose 300. And the hose 30
0, the air is supplied into the tubular members 110 and 120 through the tubular members 110 and 120.
The inside air can be taken in and exhausted. The hoses 300 may be individually connected to the air supply / exhaust section, or a valve may be provided at a predetermined position so that air is uniformly supplied to both the tubular members 110 and 120. . In this way, when the air is supplied to lift the wave absorber, both tubular members 11
0, 120 floats evenly, and the tubular members 110, 1
20 can be prevented from contacting each other and being damaged.

According to this embodiment, when air is supplied to the pair of tubular members 110 and 120 by the air supply / exhaust device, the tubular members 110 and 120 float on the water as a so-called float. The waves on the water surface are eliminated by these tubular members 110 and 120, and the waves in the work area can be suppressed. Moreover, since these tubular members 110 and 120 are a pair of members arranged and connected in parallel with each other, for example, in FIG.
After the attenuation at 10, the sufficiently attenuated wave transmitted through the tubular member 110 is further eliminated at the other tubular member 120, so that the wave can be effectively eliminated.

Since the canvas 200 is attached to each of the tubular members 110 and 120 along the longitudinal direction, if the tubular members 110 and 120 float,
The canvas 200 is suspended in water by the weight 210. By this canvas 200, the water flow in the water can be suppressed, and the mud and the like generated in the water during the dredging work and the like are diffused under the influence of the waves, in combination with the wave extinction of the water surface by the tubular members 110 and 120, Leakage from inside the construction area to the outside can be prevented. Moreover, since the canvas 200 is attached to each of the tubular members 110 and 120, the pair of tubular members 110 and
Similarly to the wave extinction by 120, it is possible to effectively prevent mud and the like from leaking from inside the construction area to the outside.

On the other hand, when the air in each of the tubular members 110 and 120 is exhausted by the air supply / exhaust device, each of the tubular members 110 and 120 is flexible and contracts, and its buoyancy is reduced. . Referring to FIG. 2 at the same time, since the weight 140 for forced settlement is provided at one end of each of the tubular members 110 and 120, each of the tubular members 110 and 120 having reduced buoyancy is provided.
Does not bend extremely, but sinks smoothly in water from the one end where the forced sinking weight 140 is provided. As a result, the floating sinker is submerged in water,
Or, even if the floating is repeated again, each of the tubular members 110 and 120 is not damaged, and the floating / sinking type wave absorber becomes extremely excellent in durability. In addition, there is no need for a conventional facility for bleeding air from both ends of each of the tubular members 110 and 120, so that the floating / sinking type wave absorber can be easily lowered or raised.

In particular, in this embodiment, since the distance d between the axes of the pair of tubular members 110 and 120 is set to 5 m, the pair of tubular members 110 and 120 simultaneously move up and down on the waves. Can be avoided.
Because, from experience, the wavelength of waves generated on the sea is usually within a maximum of 10 m, and the pair of tubular members 1
If the distance d between the axes of 10, 120 is set to one half or more of the wavelength of the wave generated on the water surface, even if one of the tubular members moves up and down on the wave, the other tubular member will not move. This is because the member can be prevented from moving up and down in conjunction with the one tubular member. Therefore, the water flow in the water can be suppressed by any one of the canvases 200, and the diffusion of the mud or the like due to the effect of the waves can be surely prevented.

Further, since the length from the upper side to the lower side of the canvas 200 is set to 4 m, the canvas 200 can effectively attenuate the energy of the wave passing through the floating-sinking body. Because the water particles inside the waves
It also has a rotational motion, and the motion of this water particle
It extends to a depth of about half a wavelength below the water surface. The velocity of this water particle is
It is fastest near the water surface and decreases linearly as the water depth increases. Also, the energy of the waves is proportional to the square of the velocity of the water particles. Therefore, the length of the canvas 200 is 4
m, the maximum wavelength of the wave is 10m,
The sail 200 can affect 80 percent of the velocity distribution of the water particles. That is, the canvas 200
Can affect more than about 96 percent of the energy of the wave.

Therefore, each of the above dimensions is a preferred embodiment in which a remarkable wave canceling effect can be obtained. Next, the results of a comparative wave-dissipation experiment of the floating-sink type wave absorber according to the present invention will be described. Wave-dissipation experiments were performed on floating-sink type wave absorbers of the type shown in FIGS. Among them, the floating / sinking type wave absorber according to the present invention is of the type shown in (c), and the above-mentioned dimensions are the outer diameter of the tubular member S = 150 mm, the center distance d = 500 mm, and the canvas length L = 500 mm.

On the other hand, (a), (b) and (d)
The type shown in (c) was used in a comparative experiment for the floating-sink type wave absorber of the type (c). To explain each type, the outer diameter S of the tubular member and the canvas length L of the type (a) are the same as those of the type (c). It is composed of a tubular member and canvas. In the case of the type (b), the outer diameter S of the tubular member, the distance d between the shafts, and the canvas length L are the same as those of the type (c). The small floating body T is provided instead of the tubular member on the side where no canvas is attached. In addition, a connecting member made of the same material as the canvas is attached between the tubular member and the small floating body T. Furthermore, the type of (d)
This is a variation of the type (a), in which the length of the canvas is doubled,
A rubber body G having the same outer diameter as the outer diameter S of the tubular member is attached to the middle of the canvas. The rubber body G has a hollow structure, and water is sealed therein.

Under the above conditions, each floating-sinking type wave absorber was floated on a water surface having a sufficient water depth, and waves of various wavelengths were generated to examine the wave-eliminating effect. FIG. 4 is a graph showing the results, in which the horizontal axis represents the wave period and the vertical axis represents the transmittance of the given wave. Note that, between the period t of the deep sea wave and the wavelength λ,

[0030]

Λ = 1.56t ² −−−−−−−−− (I) Referring to FIG. 4, comparing the types (a) and (b) with the type (c), it is clearly better that the tubular member and the canvas are provided as a pair rather than a single one. This shows the wave elimination performance. Moreover, compared to the type (d), it can be seen that the wave breaking effect is higher when the tubular members are connected in parallel so that they are parallel to each other in the water surface direction than when they are connected in series in the water depth direction.

Further, since the distance between the axles and the length of the canvas are set to 500 mm, the above equation (I) may theoretically affect waves having a period of 0.8 seconds or less. It should have been possible, and the type (c) described above was able to obtain the wave-breaking effect most consistent with the theory. From the above experimental results, if the wavelength of a wave generated on the sea is usually 10 m, in order to effectively eliminate the wave having this wavelength, the distance between the shafts and the length of the canvas according to the above-described embodiment are required. It is confirmed that setting is effective.

[0032]

According to the first aspect of the present invention, when air in the bag body is exhausted by the air supply / exhaust device, the bag body contracts to reduce its buoyancy, and the one end provided with the forced sinking weight is provided. It sinks in water in order from the side. Accordingly, when the floating / sinking type wave absorber is submerged in water, the bag body is not bent excessively, and it is possible to prevent the floating / sinking type wave absorber from being damaged even if the floating and sinking is repeated. In addition, since the air supply / exhaust device is connected only to the other end of the bag, the device can be simplified and the cost of the floating / sinking type wave absorber can be reduced as compared with the related art.

Further, according to the second aspect of the present invention, since the bag is formed of a tubular member, the bag can be easily manufactured, thereby providing a floating and sinking wave body at low cost. it can. In addition, the tubular members are provided in a pair in the water surface direction, and furthermore, since the canvas is attached to each of the pair of tubular members, the wave on the water surface is canceled by one of the tubular members. Further, while the other tubular member cancels the waves, the flow of the underwater water flow due to the influence of the waves can be effectively suppressed, and the underwater work can be easily performed.

In particular, according to the third aspect of the present invention, since the interval between the pair of tubular members is set to 5 m or more, a wavelength of 10 m usually generated on the sea where this type of wave absorber is used. The following waves can be effectively eliminated, which is preferable. Further, since the length from one end to the other end of the canvas is set to 4 m or more in the invention of claim 4, the wavelength of 1 wavelength normally generated on the sea where this type of wave absorber is used.
The kinetic energy of water particles in the depth direction caused by waves of 0 m or less can be effectively attenuated, and the diffusion of mud and the like due to the effects of waves can be effectively prevented, so that underwater work is further facilitated. be able to.

[Brief description of the drawings]

FIG. 1 is a partially sectional perspective view showing a schematic configuration of a floating-sink type wave absorber according to one embodiment of the present invention.

FIG. 2 is a front view showing a sinking state of the floating-sink type wave absorber.

FIG. 3 (a) used in a comparative wave-dissipation experiment of a floating-sink type wave-dissipating body.
It is a schematic diagram of the floating-sink type | mold wave absorber of a type (d).

FIG. 4 is a graph showing the results of a comparative wave-dissipation experiment of a floating-sink type wave absorber.

FIG. 5 is a partially sectional perspective view showing a conventional floating-sink type wave absorber.

FIG. 6 is a front view showing a sinking state of a conventional floating-sink type wave absorber.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 bag 110 tubular member 120 tubular member 130 connecting member 140 weight for forced settlement 200 canvas 210 weight 300 hose

Claims (4)

(57) [Claims] 1. An elongated bag body which is flexible and floats on the water by being filled with air, an upper end is attached along the longitudinal direction of the bag body, and a weight is attached to a lower end. A canvas that suppresses the flow of water under the influence of waves by dripping from the bag body into the water; an air supply / exhaust device that supplies or exhausts air to / from the bag body; When the air in the bag body is exhausted by the device, the weight of the forced squat is provided with a weight for forced sinking that forcibly sinks the bag and canvas into the water. A floating-sink type wave absorber provided at one end in the longitudinal direction of the body, wherein the air supply / exhaust device is connected to the other end in the longitudinal direction of the bag body. 2. The bag body is composed of a pair of tubular members arranged and connected in parallel to each other in a water surface state while floating on the water, and in a longitudinal direction of each of the pair of tubular members. The floating-sink type wave absorber according to claim 1, wherein the canvas is attached along the wave-absorbing body. 3. The distance between said pair of tubular members is 5 m.
3. The floating / sinking type wave absorber according to claim 2, wherein: 4. The length from the upper end to the lower end of the canvas is 4
m or more.
Floating and sinking type wave absorber as described.