JP2008184761A - Wave protection structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wave protection structure, efficiently absorbing energy of waves without excessively increasing the size of steel products. <P>SOLUTION: This wave protection structure 21 includes a plurality of columnar bodies 28a-28c vertically driven at predetermined spaces in a foundation ground 27 through a concrete sill 23; and wall bodies 29a,29b installed to cover each space between the columnar bodies. In this embodiment, the columnar body 28 uses H-shape steel, and the wall bodies 29 are constructed by disposing channel steels in the horizontal direction, vertically stacking the same in a lower horizontal member 33 of the lower part, and installing the same vertically with a void 35 in an upper horizontal member 31 of the upper part. In the rear of the void 35, a capture body 36 extending in the horizontal direction is constructed on the adjacent columnar body. The presence of the void 35 reduces the impact energy of tsunami, and driftwood passing through the tsunami is captured by the capture body 36. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wave protection structure, and more particularly to a wave protection structure for protecting facilities and the like provided in coastal areas from waves such as tsunami and storm surge.

  Conventionally, as a wave protection structure, a concrete embankment is generally constructed. There are also attempts to defend against tsunamis at a revetment that combines a wave-dissipating block and a breakwater. Furthermore, there are cases where the location where the tsunami arrives is limited in advance, the ground is raised to a safe height even when the tsunami arrives, and an important facility such as an oil tank or a factory plant is constructed thereon.

Further, as described in Patent Document 1, a method of placing a steel material such as a steel sheet pile as a vertical wall has been proposed.
JP 59-61605 A

  In the conventional method of constructing a dike or breakwater as described above, enormous time and work site are required to secure a site for construction.

  Further, in the method of placing the steel sheet pile as a vertical wall as described above, it is necessary to increase the steel material strength of the sheet pile in order to sufficiently protect against a tsunami or storm surge with high wave energy. In order to increase the strength of the steel material, for example, the thickness of the steel material must be increased. As a result, the weight of the steel material increases and the working efficiency decreases.

  This invention was made in order to solve the above-mentioned subject, and it aims at providing a wave protection structure which can absorb energy, such as a wave, efficiently, without making steel material weight etc. excessively large. To do.

  In order to achieve the above object, an invention according to claim 1 is a wave protection structure installed on a foundation ground, and is driven into the foundation ground at a predetermined interval, and has a plurality of columnar shapes standing in a vertical direction. A body and a wall body installed so as to block each of the adjacent columnar bodies among the columnar bodies, and an opening is formed in a part of the wall body.

  If comprised in this way, when a tsunami etc. will approach a wall body, the part will pass an opening.

  According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the opening is formed only at an upper position of the wall body.

  If comprised in this way, the penetration | invasion of the tsunami etc. to the position of an opening will be blocked | prevented, and the part will pass with respect to the tsunami etc. beyond the position of an opening.

  According to a third aspect of the present invention, in the configuration of the first or second aspect of the present invention, the wall body is provided so as to face the opening, and capture means capable of capturing a driftwood or the like that attempts to pass through the opening is provided. It is provided.

  If comprised in this way, the penetration | invasion through opening, such as driftwood, will be reduced.

  According to a fourth aspect of the present invention, in the configuration of any of the first to third aspects of the present invention, the wall body is configured to be arranged vertically and has a plurality of horizontal members having a substantially constant cross section extending in the horizontal direction. The opening is constituted by a gap between the horizontal members arranged at intervals in the vertical direction among the horizontal members.

  If comprised in this way, the up-and-down width of a space | gap can be adjusted with the installation position of a horizontal member.

  According to a fifth aspect of the present invention, in the configuration of the fourth aspect of the present invention, the capturing means includes a rod-shaped capturing body arranged horizontally along the gap.

  If comprised in this way, the supplement in the whole area of the horizontal direction of a space | gap will be attained.

  According to a sixth aspect of the present invention, in the configuration of the fifth aspect of the invention, the capturing body includes a steel chain and an elastic body in which the steel chain is embedded in a loosened state.

  If comprised in this way, a steel chain will be extended with an elastic body with the force added to the capture body by driftwood etc., and tensile force will be transmitted to a steel chain after that.

  As described above, when the tsunami or the like presses against the wall body, the invention according to claim 1 partly passes through the opening, so that the impact due to the tsunami or the like is alleviated, so the strength of the columnar body and the wall body is reduced. It can be set low.

  In addition to the effect of the invention of claim 1, the invention described in claim 2 is prevented from entering a tsunami or the like up to the position of the opening, and part of the tsunami or the like beyond the position of the opening passes through. . As a result, the shock is mitigated only for a tsunami having a high impact energy, so that an efficient wave protection structure is obtained.

  In addition to the effects of the invention described in claim 1 or 2, the invention described in claim 3 reduces the intrusion through the opening of a driftwood or the like, so that damage caused by the intrusion of driftwood can be reduced.

  In addition to the effects of the invention according to any one of claims 1 to 3, the invention according to claim 4 can adjust the vertical width of the gap according to the installation position of the horizontal member, so that the expected size of the tsunami, etc. It is easy to use because the appropriate opening can be set easily.

  According to the fifth aspect of the invention, in addition to the effect of the fourth aspect of the invention, it is possible to supplement the entire region in the lateral direction of the gap, so that the capture reliability is improved.

  In addition to the effect of the invention of claim 5, the invention of claim 6 is because the steel chain is stretched together with the elastic body by the force applied to the capturing body by driftwood or the like, and then the tensile force is transmitted to the steel chain. As a result, the energy absorbed by the capturing body is surely increased as compared with the structure of the steel chain alone.

  FIG. 1 is a schematic perspective view showing an installation state of a wave protection structure according to a first embodiment of the present invention.

  With reference to the figure, the wave protection structure 21 is installed so as to surround the oil tank 24a and the oil tank 24b installed on the concrete base 23. The oil tank 24a and the oil tank 24b are protected from changes in the sea surface 25 caused by tsunamis, storm surges, and the like.

  FIG. 2 is a front view showing the appearance of the wave protection structure shown in FIG.

  Referring to the drawing, the wave protection structure 21 covers columnar bodies 28a to 28c that are driven in a vertical direction at a predetermined interval on a foundation ground 27 via a concrete base 23, and a space between them. It is comprised from the attached wall body 29a and the wall body 29b. In this embodiment, the columnar body 28 uses H-shaped steel, and the wall body 29 has a groove-shaped steel disposed in the horizontal direction, and the lower horizontal member 33 disposed in the lower portion uses this. The upper horizontal member 31 that is stacked up and down and disposed in the upper portion is installed vertically with a gap 35 therebetween. In this embodiment, the vertical interval of the gap 35 substantially coincides with the vertical width of one upper horizontal member, but may be set according to the size of an assumed tsunami or the like. In addition, a bar-shaped capturing body 36 extending in the horizontal direction is installed on the adjacent columnar body behind the gap 35.

  3 is an enlarged sectional view taken along line III-III shown in FIG. 2, FIG. 4 is a sectional view taken along line IV-IV shown in FIG. 2, and FIG. It is an enlarged view.

  With reference to these drawings, the columnar body 28b is installed so that the (columnar body) flange portion 38a and the flange portion 38b are parallel to the arrangement direction of the wall body 29a and the wall body 29b. Each of the three horizontal members 31 constituting the upper portion of the wall body 29 and the seven horizontal members 33 constituting the lower portion have the same shape, and the (horizontal member) flange portion of the grooved steel is vertically horizontal. It is arranged to be in the direction. That is, as shown in FIG. 3, the parts constituting the horizontal member 31 and the horizontal member 33 are connected to the vertical part (web) extending in the vertical direction and the upper end of the vertical part (web) and extend in the horizontal direction. The upper horizontal portion (flange portion) and the lower horizontal portion (flange portion) connected to the lower end of the vertical portion and extending in the horizontal direction are configured.

  Each of the horizontal members 31a to 31c is arranged above and below with a gap 35a and a gap 35b, which are fixed to the inner surface side of the flange portion 38 of the columnar body 28 by bolts 41 and nuts 42. Yes.

  On the other hand, each of the horizontal member 33a to the horizontal member 33g is installed in a piled up and down state, and is fixed to the inner surface side of the flange portion 38 of the columnar body 28 by a bolt and a nut, and is also a bolt 47. And a nut 48. A predetermined gap 35c is also provided between the upper horizontal member 31c and the lower horizontal member 33a. Further, rod-shaped capturing bodies 36a to 36c serving as capturing means are installed between the columnar bodies 28 adjacent in the horizontal direction at the rear positions facing the clearances 35a to 35c. The structure and function of the capturing body 36 will be described later.

  A cushioning material 39 is installed between the rear surfaces of the vertical portions of the horizontal members 31 a to 31 c and the horizontal members 33 a to 33 g and the inner surface of the flange portion 38 of the columnar body 28.

  FIG. 6 is a cross-sectional view showing a schematic shape of the cushioning material 39 shown in FIG.

  Referring to the figure, the buffer material 39 is made of an elastic material such as rubber (CR), and is integrally connected to the belt-like sheet portion 50 along both side edges of the sheet portion 50. It is composed of a pair of projecting portions 51a and 51b having a circular cross section having a large diameter H. Since the cushioning member 39 has such a cross-sectional shape, the upper part and the lower part of each of the projections 51 a and 51 b are the rear surface of the vertical part of the horizontal member 31 or the horizontal member 33 and the flange of the columnar body 28. It will contact | abut to the inner surface of the part 38, and the water stop effect is exhibited. In particular, since the horizontal members 33a to 33g are stacked in the vertical direction as described above, the intrusion of seawater or the like is effectively prevented even through the contact surface with the columnar body. And the thickness of the sheet | seat part 50 of the shock absorbing material 39 is set to 2 mm, and the diameter H of the projection part 51 is set to 10 mm. Here, an experimental example for explaining the buffer effect of the buffer material 39 is shown below. The buffer material 39 may have a flat plate shape that does not have a protrusion.

  In the experiment, a buffer material made of a plurality of rubber sheets (CR) having different thicknesses is arranged on the surface of a steel material made of an iron plate or the like, and a steel ball having a mass of 300 kg is made to collide with it at several kinds of collision speeds. The following table shows the results of this experiment.

表にあっては、横軸に鋼球の衝突速度を採り、縦軸に鋼材が受ける衝撃力を採っている。鋼材に対しては、ゴムシートを配置していないものと、ゴムシートの厚さを２ｍｍ、１０ｍｍ、２０ｍｍ、４０ｍｍとしたものをそれぞれ配置し、計５種類の被衝突物とした。この５種類の対象物に衝突物である鋼球の衝突速度を変えて、その衝撃力を測定した。

In the table, the horizontal axis represents the collision speed of the steel ball, and the vertical axis represents the impact force applied to the steel material. With respect to the steel material, a steel sheet without a rubber sheet and a steel sheet with a thickness of 2 mm, 10 mm, 20 mm, and 40 mm were arranged, respectively, for a total of five types of impacted objects. The impact force was measured by changing the collision speed of the steel ball as the collision object to these five types of objects.

  According to this experimental result, it is found that when the thickness of the rubber sheet is 2 mm, the buffering effect is exhibited, but when the thickness is 10 mm or more, the buffering effect does not change so much.

  From the above experimental results, it is found that in the cushioning material 39, the portion of the sheet portion 50 exhibits a cushioning effect. In addition, it can be expected that stress concentrates on the protrusion 51a and the protrusion 51b due to the shape thereof, and an effective water stop effect is exhibited.

  Returning to FIG. 3, the back surface of each vertical portion of the upper horizontal member 31 a to the upper horizontal member 31 c and the lower horizontal member 33 a to the lower horizontal member 33 g arranged as described above, and the inner surface of the flange portion 38 of the columnar body 28. A cushioning material 39 is installed between the two. Therefore, the impact applied to the upper horizontal member 31 and the lower horizontal member 33 by a tsunami or the like is alleviated and transmitted to the columnar body 28. Therefore, energy such as waves can be efficiently absorbed without excessively increasing the weight or the like of the steel material constituting these structures.

  Furthermore, in the wall body 29 according to this embodiment, an opening made up of the gap 35a to the gap 35c is formed. Therefore, a part of the tsunami that has traveled above the wall body 29 passes to the back side through the gaps 35a to 35c, so that the impact caused by the tsunami and the like is further alleviated. On the other hand, since the tsunami or the like that has traveled only to the lower part of the wall 29 is low in energy, the lower horizontal member 33a to the lower horizontal member 33g are configured to prevent the passage thereof almost entirely. As described above, in the wall body 29 according to the present embodiment, by forming an opening upward, energy such as a tsunami can be efficiently reduced according to its size, and the wall body 29 itself is also efficient. It has a simple structure.

  In this embodiment, the front portion of the connecting portion of the upper horizontal member 31 and the lower horizontal member 33 to the columnar body 28 is covered by the flange portion on the front side of the columnar body 28. This avoids the impact of waves and the like being directly applied to the connecting portion, and in combination with the cushioning effect of the cushioning material 39, the reliability of the wave protection structure 21 is further improved.

  FIG. 7 is a view corresponding to FIG. 2 and is a view of the wave protection structure according to the first embodiment of the present invention as seen from the rear side. FIG. 8 is a “B” portion shown in FIG. FIG. 9 is a sectional view taken along line IX-IX shown in FIG.

  Referring to these drawings, the capturing body 36 is detachably attached so as to be horizontally hung over each of the flange portions 38 on the back side of the adjacent columnar body 28 at a rear position facing the gap 35. Yes. Specifically, it is attached via a shackle 54 to a U-shaped bolt 55 attached to the flange portion 38a by a nut 56a and a nut 56b.

  FIG. 10 is a partially broken perspective view for showing a schematic configuration of the capturing body 36 shown in FIGS.

  Referring to the drawing, the capturing body 36 is composed of a steel chain 57 in a relaxed state and an elastic body 58 such as rubber (CR) formed so as to be embedded therein. Therefore, the elastic body 58 is also filled in the gap 59 between the chains. As a result, the capturing body 36 becomes a structure having a larger tensile absorption energy than that of the chain 57 alone that does not include the elastic body 58. In addition, since the surface of the chain 57 is covered with the elastic body 58, solid objects such as driftwood included in the tsunami do not directly collide with the chain 57, so that the chain 57 is not worn and durability is improved.

  FIG. 11 is a graph showing the relationship between the amount of displacement and the load for explaining the phenomenon of increase in the tensile absorption energy of the capturing body 36.

  Referring to the figure, the amount of displacement is taken on the horizontal axis, and the load is taken on the vertical axis. F on the vertical axis indicates the yield strength of the chain due to tension. In a structure having only a steel chain, the amount of displacement when the yield strength is reached is L1. Therefore, in the structure of the steel chain alone capturing body, the tensile absorption energy corresponds to the area of the hatched portion by the solid line.

  On the other hand, in the capturing body combining the elastic body and the steel chain in the present embodiment, the steel chain is configured in a relaxed state, and therefore when the tensile force is applied, the elastic body and the chain are in the initial stage. And will grow first. Thereafter, when a tensile force is further applied, the chain is in a tension state and reaches the yield strength. That is, in the structure of the capturing body in this embodiment, the tensile absorption energy corresponds to the area of the hatched portion in the broken line. Therefore, in the capturing body of the present embodiment, the tensile absorption energy is remarkably increased as compared with the normal structure having only the constituent chain.

  Next, the function of the capturing body 36 will be described. As described above, the gap 35 is formed between the upper horizontal members 31 constituting the upper portion of the wall body 29. Therefore, when a tsunami or the like that reaches above the wall body 29 proceeds, a part of the tsunami passes through the gap 35. At this time, if a solid object such as driftwood is included in the tsunami or the like, it may pass through the gap 35 depending on its size. If the solid object passes, there is a possibility of colliding with the facility to be protected by the wall body 29 and damaging it. Therefore, the trapping body 36 is arranged on the rear side of the gap 35 so as to trap driftwood or the like passing through the gap 35.

  When the capturing body 36 captures a driftwood or the like, the impact of the driftwood is absorbed. This impact energy is transmitted from the capturing body 36 to the columnar body 28 via the U-shaped bolt. Since the capturing body 36 has the structure shown in FIG. 10, the impact absorption energy is large, and the impact applied to the columnar body 28 is reduced. As a result, the impact received by the entire wall body 29 can be mitigated, and driftwood and the like that are not desired to pass through can be captured, thereby improving the reliability of the wave protection structure.

  In the first embodiment described above, the columnar body and the wall body are configured by using a steel material having a specific shape, but may be a steel material having another shape, or may be another block such as a concrete block. The present invention can be similarly applied to a material configured using materials.

  In the first embodiment, the gap is provided between the upper horizontal members as the opening of the wall body. However, the position of the opening does not have to be upper, or the openings are formed uniformly over the entire surface. You may do it.

  Furthermore, in the first embodiment described above, the lower horizontal members are merely stacked, but a water stop material or the like may be inserted between them to stop the water.

  Furthermore, in the first embodiment, the capturing body is provided in the horizontal direction, but the capturing body is not necessarily required, and the direction and the longitudinal direction may be sufficient. The capturing body may be provided in front of the gap.

  Furthermore, in the first embodiment, the capturing body is composed of a single composite composed of a steel chain and an elastic body. However, the capturing body may be composed of only a steel chain, You may attach so that the composite of this may be connected. Moreover, when it comprises only a steel chain, it is more preferable if a shock absorber is attached to at least one end.

  Furthermore, in the above embodiment, the wall body is attached to the inner surface of the flange portion on the rear side of the H-shaped steel constituting the columnar body, but the wall body may be attached to the outer surface of the flange on the outer surface side. In this case, the capturing body may also be attached to the inner surface side of the flange.

  Further, in the first embodiment, CR rubber is used as the cushioning material and the elastic body. However, other rubbers such as EPT and natural rubber may be used, or the cushioning effect and elasticity other than rubber may be used. You may use the material which has an effect. Moreover, you may mix | blend recycled materials (rubber chip, glass scraps, etc.) with a buffer material or an elastic body as an extender.

  Furthermore, in the first embodiment described above, the cushioning material has a specific cross-sectional shape, but may have another cross-sectional shape. Further, there is no need for a buffer material.

Further, in the first embodiment, nothing is attached to the front surface of the horizontal member, but a shock absorber made of a cushioning material such as CR rubber is installed on the surface where waves and driftwood collide. May be.
In this case, the thickness is desirably 10 mm or more.

  Furthermore, in the first embodiment described above, the grooved steel having the same cross section is used as the horizontal member, but other steels or other steel materials having substantially the same cross section may be used.

It is the schematic perspective view which showed the installation state of the wave protection structure by 1st Embodiment of this invention. It is the front view which showed the external appearance shape of the wave protection structure shown in FIG. It is an expanded sectional view of the III-III line shown in FIG. It is sectional drawing of the IV-IV line shown in FIG. FIG. 4 is an enlarged view of a portion “A” shown in FIG. 3. It is an expanded sectional view of the buffer material 39 shown in FIG. It is the figure which looked at the external appearance shape of the wave protection structure shown in FIG. 1 from the back side. FIG. 4 is an enlarged view of a “B” portion shown in FIG. 3. It is sectional drawing of the IX-IX line shown in FIG. FIG. 8 is a partially broken perspective view showing a schematic structure of the capturing body shown in FIG. 7. It is the graph which showed the relevant characteristic of the displacement amount and load of the capture body shown in FIG. 10 with the general structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 ... Wave protection structure 28 ... Columnar body 29 ... Wall body 31 ... Upper horizontal member 33 ... Lower horizontal member 35 ... Gap 57 ... Chain 58 ... Elastic body 59 ... Gap In addition, the same code | symbol in each figure is the same or it corresponds. Show.

Claims (6)

A wave protection structure installed on the foundation ground,
A plurality of columnar bodies that are driven into the foundation ground at a predetermined interval and are erected in a vertical direction;
Among the columnar bodies, including a wall body that is installed so as to block between each of the adjacent columnar bodies,
A wave protection structure in which an opening is formed in a part of the wall. The wave protection structure according to claim 1, wherein the opening is formed only at a position above the wall body. The wave protection structure according to claim 1, wherein the wall body is provided so as to face the opening, and includes a capturing unit that can capture a driftwood or the like that is about to pass through the opening. The wall body is composed of a plurality of horizontal members having a substantially constant cross section that are arranged vertically and extending in the horizontal direction, and the opening is a gap between horizontal members that are spaced apart from each other in the horizontal direction. The wave protection structure according to any one of claims 1 to 3, comprising: The wave protection structure according to claim 4, wherein the capturing means includes a rod-shaped capturing body disposed in a horizontal direction along the gap. The wave protection structure according to claim 5, wherein the capturing body includes a steel chain and an elastic body that embeds the steel chain in a loosened state.

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