JP3579715B2 - Wave breaker using visco-elasto-plastic member - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wave absorber that reduces waves on the surface of water.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, facilities such as breakwaters and breakwaters (hereinafter, referred to as “wave-breaking facilities”) are provided in ports and coasts for the purpose of reducing incident waves and keeping the bay calm. I have. Many of these wave-breaking facilities consist of large-scale, rigid structures such as concrete caissons and wave-breaking blocks, which reflect or attenuate incident waves to perform wave-damping. I have.
[0003]
[Problems to be solved by the invention]
However, the above-mentioned conventional wave-dissipating facilities are large-scale and rigid structures, and often protrude greatly above the sea, which may hinder the navigation of ships. In addition, these large-scale and rigid structures may impair the landscape such as the coast. In addition, these structures often impede the flow of water such as seawater, and may hinder the circulation of water, which may be a factor of deteriorating the environment such as the coast.
[0004]
The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a wave-dissipating facility that has few problems with respect to ship navigation, landscape, environment, and the like.
[0005]
[Means for Solving the Problems]
In order to solve the above problem, a wave absorber using a visco-elasto-plastic member according to claim 1 is a housing means (3A or 3B) provided near a water bottom (2A or 2B or 2C or 2D) and having a housing space inside. Alternatively, a plurality of tire cut pieces (4A2) formed by cutting rubber tires are housed as visco-elastic plastic members in the housing space of 3C or 3D), and water is moved by water waves (W1 or W2). Deforming the plurality of visco-elasto-plastic members , setting the shear elastic modulus G of the plurality of visco-elasto-plastic members to a value in the range of 0.1 to 10 meganewton / m ² , The installation length B _L is set to a value of about 1.0 to 2.0 times the wavelength of the wave (W1 or W2), and the installation height h _s of the plurality of visco-elasto-plastic members is set to the plurality of visco-elasto-plastic Set the value to approximately the same as the water depth d above the member. It allows the viscoelastic plastic inside the wave member (W1 or W2) energy the wave is consumed as heat energy (W1 or W2) crest conductivity K _T a minimum value of about 0.3 of the said deformation characterized in that to the.
[0006]
A wave absorber using a visco-elasto-plastic member according to claim 2 is a housing means (3A or 3B or 3C or 3D) provided near a water bottom (2A or 2B or 2C or 2D) and having a housing space inside. A plurality of molded rubbers (4A3) formed by molding with a mold from a rubber-based material are accommodated in the accommodation space as a visco-elasto-plastic member, and the movement of the water by the wave (W1 or W2) on the water surface causes the rubber to move. The plurality of visco-elasto-plastic members are deformed, the shear elastic modulus G of the plurality of visco-elasto-plastic members is set to a value in the range of 0.1 to 10 Meganewton / m ² , and the plurality of visco-elasto-plastic members are installed. the length B _L is a value of about 1.0 to 2.0 times the wavelength of the wave (W1 or W2), and said plurality of viscoelastic plastic member installation height h _s of the plurality of viscoelastic plastic member To a value approximately the same as the water depth d above Causes a minimum value of about 0.3 to crest transmissibility K _T of the energy is consumed as heat energy the wave (W1 or W2) of the wave inside of said viscoelastic plastic member to the deformation (W1 or W2) It is characterized by the following.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0008]
FIG. 1 shows a configuration of a wave canceling device according to a first embodiment of the present invention. As shown in FIG. 1, the wave absorber 1A includes a housing structure 3A and a plurality of rubber members 4A. Reference numeral 11 indicates a ship at sea.
[0009]
The housing structure 3A is constructed on the sea floor 2A, is a box-shaped structure made of a reinforced concrete structure or the like, and has an opening inside, and has a housing space inside. The upper edge of the housing structure 3A is located at substantially the same height as the sea floor 2A, and the housing space is a recess with respect to the sea floor 2A.
[0010]
The rubber member 4A is a member made of a rubber-based material. A large number of rubber members 4A are arranged inside the accommodation space.
[0011]
Examples of the rubber-based material include nitrile rubber (NBR), styrene butadiene rubber (SBR), natural rubber (NR), butyl rubber (IIR), polyisobutylene rubber, halogenated rubber, ethylene propylene rubber (EPM and EPDM), butadiene Rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), acrylic rubber (ACM and ANM), silicone rubber (Q), fluoro rubber (FKM), hydrin rubber (CO and ECO), urethane rubber (U), Polynorbornene rubber, ethylene acrylic rubber, chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), polyphosphazene rubber, and the like can be used.
[0012]
As described above, when a plurality of rubber members 4A made of a rubber material are accommodated in the accommodation space of the accommodation structure 3A provided near the sea floor 2A and having an accommodation space therein, the movement of the wave W1 on the sea surface is reduced. Is transmitted to the rubber member 4A by the seawater. Thereby, the plurality of rubber members 4A are deformed in a direction indicated by an arrow in FIG. When the rubber member 4A is deformed, the energy of the wave W1 is consumed as heat energy inside the rubber member 4A. As a result, the kinetic energy of the wave W1 gradually decreases, and the wave height of the wave W1 is reduced from the incident position P1 of the wave to the emission position P2. As a result, the wave is eliminated.
[0013]
FIG. 2 is a first diagram illustrating a wave-breaking function of the wave-breaking device shown in FIG. As shown in FIG. 2A, when a force F for one cycle due to a wave acts on the rubber member 4A, deformation (strain) occurs. In particular, shear stress causes a shear strain as indicated by ε in FIG.
[0014]
Since the rubber-based material that is the material of the rubber member 4A is not a perfect elastic body, the shear stress τ and the shear strain ε are not in a proportional relationship (linear), and plastic deformation occurs. Thus, a loop-like change (hysteresis) occurs. In FIG. 2 (B), the hatched area indicates energy consumption, and it is considered that the rate of energy consumption with respect to applied energy (energy consumption rate) is high in the rubber-based material. In addition, in FIG. 2 (B), the symbol G indicates the slope of the stress-strain curve and is called a shear modulus.
[0015]
FIG. 3 is a second diagram illustrating the wave canceling function of the wave canceling device illustrated in FIG. 1. FIG. 3A is a diagram illustrating the hardness and the wave-breaking function of the rubber member in the wave-breaking device shown in FIG. 1, and the hardness of the rubber member 4A, for example, the shear modulus G is set to 0.1 to 10 MN / m ^2: If set to an appropriate value in the range of (MN meganewtons = 10 ⁶ N), the crest transmissibility K _T waves, have been shown to be able to be a minimum value of about 0.3.
[0016]
Here, the crest transmissibility K _T of the wave indicates the ratio of the transmission wave height to incident wave height (transmitted wave height / incident wave height). The incident wave height indicates the wave height (the height between the highest point of the wave peak and the lowest point of the valley, or the amplitude value of the wave) at the position P1 where the wave W1 enters the wave canceling device 1A. The wave height indicates the wave height (the height between the highest point of the wave peak and the lowest point of the valley, or the amplitude value of the wave) at the position P2 where the wave W1 is emitted from the wave canceling device 1A.
[0017]
3 (B) is a diagram showing parameters related to crest conductivity K _T wave. Crest transmissibility K _T waves, installation length B _L of the rubber member shown in FIG. 3 (B) decreases the longer, the efficiency of the wave dissipating increases. Further, crest transmissibility K _T wave becomes smaller the higher the installation height h _s of the rubber member shown in FIG. 3 (B), the efficiency of the wave dissipating increases. Further, crest transmissibility K _T wave becomes smaller as the depth h shown in FIG. 3 (B), or depth d of the rubber member smaller, the efficiency of the wave dissipating increases. Of course, the wave height transmissivity _KT also changes depending on the hardness (for example, the shear modulus G) of the rubber member 4A, the period of the wave W1, and the wave height. Generally, the installation length B _L of the rubber member is about 1.0 to 2.0 times the wavelength of the wave W1, and the installation height h _s of the rubber member is approximately the same as the water depth d on the rubber member. case, the crest transmissibility K _T of the wave can be set to a value of about 0.3.
[0018]
In the above-described wave absorber 1A, the energy of the wave is consumed by the water flowing in the gap between the rubber members 4A and 4A due to friction between the water and the rubber member or generation of a vortex in the gap. However, the main energy consumption of the device 1A is the internal energy consumption of the rubber member 4A.
[0019]
FIG. 4 is a diagram illustrating a configuration example of a rubber member used in the wave canceling device illustrated in FIG. 1. As the rubber member, as shown in FIG. 4A, a rubber tire 4A1 as a recycled material can be used. Further, as shown in FIG. 4B, as the rubber member, a tire cut piece 4A2 formed by cutting a rubber tire can be used. In the case of the tire cut piece 4A2, the porosity between the rubber members can be adjusted by appropriately setting the dimensions such as the length of the cut piece. Further, as shown in FIG. 4C, as the rubber member, a molded rubber 4A3 formed by molding a rubber-based material with a mold or the like can be used. In the case of the molded rubber 4A3, the porosity between the rubber members can be adjusted by appropriately setting the dimensions of each position of the molded rubber. In the case of the molded rubber 4A3, the energy consumption rate inside the rubber member can be adjusted by appropriately setting the hardness (for example, the shear modulus G) of the rubber-based material as the material. .
[0020]
FIG. 5 is a diagram showing a first example of a place where the above-described wave canceling device 1A is installed. As shown in FIG. 5, it may be installed in the openings 23 of the existing breakwaters 21 and 22 to perform wave extinction. FIG. 6 is a diagram showing a second example of a place where the above-described wave canceling device 1A is installed. As shown in FIG. 6, an existing pier 24 may be installed as a wave-eliminating means so as to extinguish waves. In FIG. 6, reference numerals 12 and 13 indicate marine vessels. Of course, it can be used as a substitute for a normal breakwater or a breakwater.
[0021]
FIG. 7 shows a configuration of a wave canceling device according to a second embodiment of the present invention. As shown in FIG. 7, the wave absorber 1B includes a housing structure 3B and a plurality of rubber members 4B. Reference numeral 14 indicates a marine vessel.
[0022]
The storage structure 3B is constructed on the sea floor 2B, is a box-shaped structure made of a reinforced concrete structure or the like and having an open top, and has a storage space inside. The upper edge of the housing structure 3B is located higher than the sea floor 2B. In the case of the second embodiment, the wave breaker 1B constitutes a kind of submerged levee.
[0023]
Even in the configuration of the second embodiment 1B, the motion of the wave W2 on the sea surface is transmitted to the rubber member 4B by the seawater, as in the case of the first embodiment 1A. Thereby, the plurality of rubber members 4B are deformed, and when the rubber members 4B are deformed, the energy of the wave W2 is consumed as heat energy inside the rubber member 4B. Thereby, the kinetic energy of the wave W2 gradually decreases, and as a result, wave extinction is performed.
[0024]
FIG. 8 shows a configuration of a wave canceling device according to a third embodiment of the present invention. As shown in FIG. 8, the wave absorber 1C includes a housing structure 3C, a plurality of rubber members 4C, and a protection sheet 5.
[0025]
The housing structure 3C is constructed on the sea floor 2C, is a box-shaped structure made of a reinforced concrete structure and the like, and has an opening inside, and has a housing space inside. The feature of the wave canceling device 1C of the third embodiment is that the protective sheet 5 is provided on the upper part of the housing structure 3C, and the other configuration is the above-described first embodiment or the second embodiment. Is the same as
[0026]
As the protective sheet 5, a sheet member made of a synthetic resin material having flexibility can be used.
[0027]
Even with the configuration of the third embodiment 1C, the motion of the waves on the surface of the sea is transmitted by the seawater and transmitted to the rubber member 4C via the protection sheet 5 as in the case of the first embodiment 1A. Is done. As a result, the plurality of rubber members 4C are deformed, and when the rubber members 4C are deformed, the energy of the waves is consumed as heat energy inside the rubber members 4C. As a result, the kinetic energy of the wave gradually decreases, and as a result, the wave is eliminated. In addition to the above effects, the protective sheet 5 can prevent the sand drifting from entering the gaps between the rubber members 4C and burying the rubber members 4C in the sand.
[0028]
FIG. 9 shows a configuration of a wave canceling device according to a fourth embodiment of the present invention. As shown in FIG. 9, the wave absorber 1D includes a housing structure 3D, a plurality of rubber members 4D, a sand discharge pump 6, a sand discharge pipe 7, and a support member 8. .
[0029]
The housing structure 3D is constructed on the sea floor 2D, is a box-shaped structure made of a reinforced concrete structure or the like and has an open top, and has a housing space inside. The feature of the wave absorber 1D of the fourth embodiment is that the support member 8 is installed inside the housing structure 3D to support the plurality of rubber members 4D, and the support member 8 has an opening through which sand can pass. A plurality of sand discharge pumps 6 are provided below the support member 8, and the sand dropped from the support member 8 and accumulated is discharged to the outside of the housing structure 3D through the sand discharge pipe 7. The other points are the same as those in the first embodiment or the second embodiment.
[0030]
Even in the configuration of the fourth embodiment 1D, the motion of the waves on the sea surface is transmitted to the rubber member 4D by the seawater, as in the case of the first embodiment 1A. As a result, the plurality of rubber members 4D are deformed, and when the rubber members 4D are deformed, the energy of the waves is consumed as heat energy inside the rubber members 4D. As a result, the kinetic energy of the wave gradually decreases, and as a result, the wave is eliminated. In addition to the above-described effects, sand is discharged to the outside at an appropriate time by the sand discharge pump 6, the sand discharge pipe 7, and the support member 8, and the drifting sand enters the gap between the rubber members 4D to cause the rubber member 4D to be sandy. Buried inside can be prevented.
[0031]
In each of the above embodiments, the storage structures 3A to 3D correspond to storage means. The rubber member 4A, the rubber tire 4A1, the tire cut piece 4A2, the molded rubber 4A3, and the rubber members 4B to 4D correspond to visco-elasto-plastic members.
[0032]
The present invention is not limited to the above embodiments. Each of the above-described embodiments is merely an example, and has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that has the same operation and effect can be obtained. It is included in the technical scope of the present invention.
[0033]
For example, in each of the above embodiments, the wave absorber installed on the sea floor has been described as an example, but the present invention is not limited to this, and other parts other than the sea floor, for example, lakes, ponds, swamps It is possible to attenuate waves on the surface of the water even if it is placed on the bottom of the inland water section.
[0034]
In each of the above embodiments, the rubber member (4A to 4D) made of a rubber material has been described as an example of the visco-elasto-plastic member disposed in the housing space, but the present invention is not limited to this. Instead, any member made of a visco-elasto-plastic material may be used.
[0035]
A visco-elasto-plastic material is a material having both visco-plastic and elastic properties. Visco-elasto-plastic materials exhibit visco-plastic properties (visco-plasticity) in the time domain where the observation time is long, and elastic materials in the time domain where the observation time is short when deformation (strain) is generated by applying an external force. (Elasticity). Here, the viscosity refers to a property of a Newtonian fluid or the like in which the stress state at an arbitrary point is proportional to the time change rate of deformation (strain), and is proportional to the viscosity coefficient. Elasticity refers to the property that the deformation (strain) when stress is applied is proportional to the stress, and the deformation (strain) returns to the original state when the stress disappears according to Hooke's law. Proportional. Further, plasticity refers to a property such that deformation (strain) under stress does not return to its original state even when the stress is removed. As such a visco-elastic plastic material, a thermoplastic elastomer material can be used in addition to the above rubber material.
[0036]
Examples of thermoplastic elastomer (Thermoplastic Elastomer: TPE) -based materials include styrene-based TPE (TPS), olefin-based TPE (TPO), PVC-based TPE, urethane-based TPE (TPU), ester-based TPE (TPEE), and polyamide-based. TPE, 1,2-polybutadiene-based TPE and the like can be used.
[0037]
Further, in each of the above embodiments, a box-shaped structure (for example, 3A, 3B or the like) having an open top made of a reinforced concrete structure or the like has been described as an example of the storage means, but the present invention is not limited to this. Instead, the side portion may be formed of steel sheet pile or the like and the inside of the side portion may be dug down to form a housing space. In this case, since the dug sea bottom also serves as the bottom of the housing structure, the housing structure does not have a bottom. In short, the housing means may be of any material and structure as long as it has a housing space provided near the water bottom and capable of housing a plurality of visco-elastic plastic members inside. .
[0038]
【The invention's effect】
As described above, according to the first aspect of the present invention, the accommodation space of the accommodation means (3A or 3B or 3C or 3D) provided near the water bottom (2A or 2B or 2C or 2D) and having an accommodation space inside. Inside, a plurality of tire cut pieces (4A2) formed by cutting rubber tires are accommodated as visco- elasto-plastic members, and the shear modulus of elasticity G of the plurality of visco-elasto-plastic members is 0.1 to 10 Meganewton / m ² . The value is set to a value within the range, the installation length B _L of the plurality of visco-elasto-plastic members is set to a value of about 1.0 to 2.0 times the wavelength of the wave (W1 or W2), and Since the installation height h _s is set to a value substantially equal to the water depth d above the plurality of visco-elasto-plastic members, a plurality of visco-elasto-plastic materials are generated by the motion of water due to the wave (W1 or W2) on the water surface. The wave is deformed inside the deformed visco-elasto-plastic member. The energy of one or W2) is consumed as heat energy, the crest transmissibility K _T wave (W1 or W2) can be the minimum value of about 0.3, has the advantage that. According to the second aspect of the present invention, rubber is provided in the housing space of the housing means (3A or 3B or 3C or 3D) provided near the water bottom (2A or 2B or 2C or 2D) and having a housing space therein. A plurality of molded rubbers (4A3) formed by molding from a system material by a mold are accommodated as visco-elastic plastic members, and the shear elastic modulus G of the plurality of visco-elastic plastic members is 0.1 to 10 meganewton / m ² . The value is set to a value within the range, the installation length B _L of the plurality of visco-elasto-plastic members is set to a value of about 1.0 to 2.0 times the wavelength of the wave (W1 or W2), and Since the installation height h _s is set to a value substantially equal to the water depth d above the plurality of visco-elasto-plastic members, a plurality of visco-elasto-plastic materials are generated by the motion of water due to the wave (W1 or W2) on the water surface. deforming the member, within the viscoelastic plastic member it deformed wave (W1 addition The energy of W2) is consumed as heat energy, the crest transmissibility K _T wave (W1 or W2) can be the minimum value of about 0.3, it has the advantage that.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram illustrating a configuration of a wave canceling device according to a first embodiment of the present invention.
FIG. 2 is a first diagram illustrating a wave canceling function of the wave canceling device illustrated in FIG. 1;
FIG. 3 is a second diagram illustrating the wave canceling function of the wave canceling device illustrated in FIG. 1;
FIG. 4 is a diagram showing a configuration example of a rubber member used in the wave canceling device shown in FIG.
FIG. 5 is a diagram showing a first example of a place where the wave absorber shown in FIG. 1 is installed.
FIG. 6 is a diagram showing a second example of a place where the wave absorber shown in FIG. 1 is installed.
FIG. 7 is a conceptual diagram illustrating a configuration of a wave canceling device according to a second embodiment of the present invention.
FIG. 8 is a conceptual diagram illustrating a configuration of a wave canceling device according to a third embodiment of the present invention.
FIG. 9 is a conceptual diagram illustrating a configuration of a wave canceling device according to a fourth embodiment of the present invention.
[Explanation of symbols]
1A to 1D Wave absorber 2A to 2D Seabed 3A to 3D Housing structure (housing means)
4A Rubber member 4A2 Tire cut piece 4A3 Molded rubber 4A1 Rubber tire 4B-4D Rubber member (visco-elastic-plastic member)
Reference Signs List 5 Protective sheet 6 Sand discharge pump 7 Sand discharge pipe 8 Support members 11 to 14 Vessels 21, 22 Breakwater 23 Opening 24 Wharf B _L Installation length of rubber member d Water depth h on rubber member h Water depth h _s Installation height of rubber member P1 Incident position P2 Outgoing position W1, W2 Wave

Claims (2)

A tire cut piece (4A2) formed by cutting a rubber tire in the accommodation space of the accommodation means (3A or 3B or 3C or 3D) provided near the water bottom (2A or 2B or 2C or 2D) and having an accommodation space therein. ) Are accommodated as a visco-elasto-plastic member, and the plurality of visco-elasto-plastic members are deformed by the movement of water due to the wave (W1 or W2) on the water surface, and the shear elastic modulus G of the plurality of visco-elasto-plastic members is changed. 0.1 to 10 is set to a value in the range of mega-newtons / m ^2, 1.0 to 2.0 times the wavelength of the installation of a plurality of viscoelastic plastic member length B _L of the wave (W1 or W2) the extent of value, and by setting the installation height h _s of the plurality of viscoelastic plastic member to a value of almost the same degree as the water depth d over said plurality of viscoelastic plastic member, said deformation the viscoelastic The wave (W1 or W2) is formed inside the plastic member. Wave dissipating device using a viscoelastic plastic member to be characterized in that is a minimum value of about 0.3 to crest transmissibility K _T of the wave is consumed as heat energy (W1 or W2) energy. In the accommodation space of the accommodation means (3A or 3B or 3C or 3D) provided near the water bottom (2A or 2B or 2C or 2D) and having an accommodation space inside, it was formed by molding from a rubber-based material with a mold. A plurality of molded rubbers (4A3) are accommodated as visco-elasto-plastic members, and the plurality of visco-elasto-plastic members are deformed by the movement of water due to waves (W1 or W2) on the water surface, and the shearing of the plurality of visco-elasto-plastic members is performed. The elastic modulus G is set to a value in the range of 0.1 to 10 meganewtons / m ² , and the installation length B _L of the plurality of visco- elastic- plastic members is set to 1.0 to the wavelength of the wave (W1 or W2). and 2.0 times the value, and by setting the installation height h _s of the plurality of viscoelastic plastic member to a value of almost the same degree as the water depth d over said plurality of viscoelastic plastic member, said deformation The wave (W1) inside the visco-elasto-plastic member Wave dissipating device using a viscoelastic plastic member with energy, characterized in that to a minimum value of about 0.3 to crest transmissibility K _T of the wave is consumed as heat energy (W1 or W2) of W2).

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