Capture Structures

Abstract

Compared to conventional sediment-related disaster prevention structures, this new structure has fewer time constraints, allows for secondary use through removal and replacement, and offers significantly improved load-bearing capacity compared to previous structures such as sandbags. As a result, it can be used as a sediment-related disaster prevention structure and can also be used in conjunction with previous structures such as sandbags, enabling the development of efficient sediment-related disaster prevention measures according to the topography and watershed conditions. [Solution] The material is made of steel that is formed into a polyhedron shape with a space inside, and has multiple openings formed on the surface of the faces that make up the polyhedron.

Description

Technical Field

[0001] The present invention relates to a gravity structure for capturing sediment, gravel, driftwood, etc. that flow down together with water, and can be used, for example, in sediment capture work for debris flows or in sediment, gravel, driftwood, etc. capture work in rivers, streams, slopes, etc., and relates to a permeable capture structure for sediment disaster countermeasures that can effectively and efficiently capture sediment, gravel, driftwood, etc.

Background Art

[0002] Conventionally, there are various capture structures that can be used for sediment capture work for debris flows or for sediment, gravel, driftwood, etc. capture work in rivers, streams, slopes, etc., for slope rockfall prevention work, and for avalanche prevention work.

[0003] These capture structures are broadly classified into permeable types and impermeable types. The permeable type has high water permeability and is characterized in that it can maintain the upstream capture space for a long period by supplying sediment, gravel, driftwood, etc. that do not directly lead to major disasters during normal times and during small and medium water discharges to the downstream side.

[0004] Among the permeable capture structures that can be used as conventional sediment disaster countermeasures, those called gravity types generally use concrete and expect resistance due to the weight of the concrete.

[0005] When placing the concrete used in such conventional capture structures on-site, a corresponding curing period is required until it hardens. For this reason, there have been problems such as time constraints until the capture structure is completed and difficulty in secondary reuse by removal and replacement.

[0006] In addition, the soil bags generally used in disaster restoration work are classified as impermeable types because they do not have water permeability. Although soil bags have advantages over the above-mentioned time constraints and transferability, etc., their uses are limited to simple rockfall and flying sand prevention measures, etc., and there has been a problem that they are not planned to be used as sediment disaster countermeasures.

Prior Art Documents

[0007] [Patent Document 1] Japanese Patent Publication No. 2008-202339 [Overview of the project] [Problems that the invention aims to solve]

[0008] Thus, the present invention was devised to address the aforementioned conventional problems, and compared to conventional sediment disaster prevention structures, it has fewer time constraints and can be reused by removal and replacement.

[0009] Furthermore, by significantly improving load-bearing capacity compared to conventional structures such as sandbags, we can provide a containment structure that can be used as a countermeasure against sediment-related disasters. It can also be used in combination with conventional structures such as sandbags, allowing for the development of efficient sediment-related disaster countermeasures according to the topography and watershed conditions. [Means for solving the problem]

[0010] The present invention relates to a steel material formed in a polyhedral shape with a space provided inside, and having multiple openings formed on the surface of the faces constituting the polyhedron. It is characterized by the following: or The aforementioned polyhedron shape is a cube shape. It is characterized by the following: or A floating prevention member is installed in the aforementioned space. It is characterized by the following: or A capture structure made of steel, formed in a polyhedral shape with a space inside, and having multiple openings formed on the surfaces of the faces constituting the polyhedron, is installed inside a structure having an opening width narrower than the opening width of the openings. It is characterized by the following: or A capture structure made of steel, formed in a polyhedral shape with internal spaces and multiple openings formed on the surfaces of the faces constituting the polyhedron, can be arranged in parallel in the front-to-back and / or width-to-back directions, and can be stacked, with adjacent capture structures being connectable by connectors. It is characterized by the following: [Effects of the Invention]

[0011] According to the present invention, compared to conventional trapping structures for landslide disaster countermeasures, there are fewer time constraints during installation, and secondary use through removal and replacement is possible. Furthermore, by significantly improving durability compared to conventional structures such as sandbags, a trapping structure usable for landslide disaster countermeasures can be provided. Moreover, by using it in combination with conventional structures such as sandbags, it has the excellent effect of enabling the planning of efficient landslide disaster countermeasures according to the topography and watershed conditions. [Brief explanation of the drawing]

[0012] [Figure 1] This is an explanatory diagram illustrating the configuration of the capture structure according to the present invention. [Figure 2] This is an explanatory diagram illustrating the differences in strength among strip-shaped steel materials. [Figure 3] This is an explanatory diagram (1) illustrating the configuration of the opening width adjustment member. [Figure 4] This is an explanatory diagram (2) illustrating the configuration of the opening width adjustment member. [Figure 5] This is an explanatory diagram (3) illustrating the configuration of the opening width adjustment member. [Figure 6] This is an explanatory diagram (1) illustrating the usage status of the capture device. [Figure 7] This is an explanatory diagram (2) illustrating the usage status of the capture device. [Figure 8] This is an explanatory diagram illustrating the use of conventional large sandbags and other similar devices in combination with a capture device. [Figure 9] This is an explanatory diagram illustrating the specific gravity of the captured structure. [Figure 10] This is an explanatory diagram illustrating one embodiment of a float prevention member. [Figure 11] It is an explanatory diagram for explaining a capturing structure with different formation positions of the opening width. [Figure 12] It is an explanatory diagram for explaining other configurations regarding the outer shape formation of the capturing device. [Figure 13] It is an explanatory diagram for comparing and explaining the present invention and a conventional example regarding the driftwood capturing performance of the capturing structure.

Embodiments for Carrying Out the Invention

[0013] The capturing structure 1 according to the present invention is formed in a polyhedral shape, for example, its upper surface is open, and the inside of the polyhedral shape is configured as a space portion 2. And a plurality of openings 3 penetrating toward the front and back sides of each surface constituting the polyhedron are formed. Further, the capturing structure 1 is made of, for example, a plate-shaped steel material and is supposed to function as a so-called permeable type capturing structure 1.

[0014] Here, the polyhedral shape is mainly composed of shapes such as a cube or a rectangular parallelepiped, but as long as it is a polyhedral shape, it is by no means limited to shapes such as a cube or a rectangular parallelepiped.

[0015] Also, a heavy floating prevention member 4 (see FIG. 10) such as an iron plate can be installed in the space portion 2, and the capturing structure 1 is such that an opening width adjusting member 6 having an opening width narrower than the opening width of the opening 3 can be laid by being attached to the opening 3 or the like.

[0016] In an embodiment of the present invention, the capturing structure 1 may be used alone, but mainly, a plurality of them can be laid in parallel in the front, rear, left, and right directions and / or stacked vertically, and thus it can also be provided as a capturing device 5 that can be formed in a form according to the situation of the construction site.

[0017] In other words, the capture structure 1, made of steel, can be formed into a cubic shape, has a space 2 inside, and has multiple openings 3 formed on the surfaces constituting the cube, which penetrate from the front to the back. These capture structures 1 can be laid in parallel in the front-to-back direction and / or the left-to-right direction (width direction), and can be laid in stacks. Furthermore, adjacent capture structures 1 can be connected with connectors to form a capture device 5.

[0018] First, Figure 1 shows the configuration of the capture structure 1 as a single unit according to the present invention. As can be seen from Figure 1, the capture structure 1 of the present invention is configured in a cubic shape.

[0019] Furthermore, multiple openings 3 are formed on the five faces of the cube, excluding the top face, and penetrate through to the front and back sides of those faces.

[0020] Furthermore, as shown in Figure 1, the two front-to-back surfaces may be configured as surfaces having the multiple openings 3, while the two left-to-right surfaces may be configured as surfaces without openings 3.

[0021] Here, we will describe an example of the procedure for manufacturing the faces having the multiple openings 3 that constitute the cube.

[0022] First, a long, strip-shaped steel material is prepared. This steel material is cut to a predetermined length and initially framed into a rectangular shape. At this time, the width, i.e., the thickness surface 7 of the strip-shaped steel material is framed so that it is perpendicular to the surface direction and the back direction of the surface.

[0023] Next, the strip-shaped steel plates are attached in a grid pattern inside the rectangular frame. This creates a grid surface with multiple openings 3 forming a grid.

[0024] When the frame is constructed in this manner, and strip-shaped steel plates are attached to the inside in a grid pattern, the width of the strip-shaped steel material, or in other words, the thickness surface 7, faces in the front-to-back direction of the surface, that is, in the front-to-back direction. In other words, the length of the width of the frame that constitutes the surface as seen from the front, and the length of the width of the outer frame of the opening that constitutes the opening 3, are configured to be the length of the thickness surface 7 of the strip-shaped steel material.

[0025] Furthermore, as mentioned above, in addition to the procedure of repeatedly cutting and welding strip-shaped steel material (steel plate), another example of a manufacturing procedure is to cut a square (square pipe) steel pipe into rings and rearrange them to form a grid surface with, for example, diamond-shaped openings 2.

[0026] By configuring it as described above, a grid-surface trapping structure 1 can be formed that has sufficient strength to adequately resist falling trapped objects flowing from the front.

[0027] Figure 2 illustrates the difference in strength of the strip-shaped steel material. As can be seen from Figures 2(a) and 2(b), the rigidity of the strip-shaped steel material is overwhelmingly higher when a load is applied in the direction of its thickness.

[0028] Then, the grid surfaces having multiple openings 3 configured as described above are placed on at least two surfaces, the front and the back, and surfaces without openings 3 are placed on the left and right sides, and these are assembled into a rectangular or square (polyhedron) shape as shown in Figure 1.

[0029] In summary, for example, a lattice surface made of steel with lattice-shaped openings 3 is constructed by framing it as described above, and at least the front and rear surfaces are assembled on that surface, or the front, rear, left and right surfaces and the bottom surface are assembled on that surface, and this constitutes one unit of the capture structure 1.

[0030] Furthermore, since the steel material having the grid-like openings 3 that make up the surface has an external shape such as a square or rectangle, one unit of the capture structure 1 takes the form of a polyhedron such as a cuboid or a rectangular prism.

[0031] Incidentally, a capture structure 1 may also be formed by punching out multiple openings 3 from a flat, rectangular steel plate using a punching tool, and then assembling the surfaces having these openings 3. In this case, the openings 3 are not limited to a rectangular grid shape, but can be formed in various shapes.

[0032] As described above, the space 2 of the capture structure 1 is designed to accommodate a heavy anti-float member 4, such as a steel plate. The capture structure 1 of the present invention is made of steel materials in a grid or polyhedral shape, and has a significantly larger unit weight compared to conventional gravity-type capture structures. However, it may still be washed away, for example, if the water flow in the streambed becomes rapidly fast. In cases where such a risk is considered, installing the anti-float member 4 in the space 2 improves resistance, thus reducing the risk of the capture structure 1 of the present invention being washed away.

[0033] Furthermore, although the capture structure 1 according to the present invention has a very high unit volume weight (specific gravity) as described above, it is thought that the weight per unit may be lighter because it has a structure with many voids overall due to having multiple openings 3. In this case, the capture function may not work effectively against flowing objects that do not involve water (for example, the impact of a single large rock), and the structure may become unstable.

[0034] As a means of solving this problem, one can use a method of securing the necessary weight by lining the inside of the capture structure 1 with anti-float members 4 such as steel plates. The required amount (weight and number) of anti-float members 4 can be determined by performing stability calculations of the capture structure 1.

[0035] Furthermore, the anti-float member 4 is not limited to heavy steel plates or the like; it may also consist of an anti-float rod inserted from above, passing through the opening 3 at the bottom, and then inserting its tip into the ground to secure the capture structure 1.

[0036] Incidentally, as mentioned above, the capture structure 1 of the present invention may have a lighter weight (kg) per unit compared to conventional capture structures. While lighter weight may mean lower resistance, it makes assembly easier and improves workability. Furthermore, the unit volume weight (kg / m³) 3 Considering this, the capture structure 1 of the present invention is significantly larger than conventional capture structures, and can be said to have superior stability, especially when accompanied by water flow.

[0037] The influence of buoyancy will now be explained with reference to Figure 9. Conventionally, these structures were mainly made of sand, stone, and concrete, with a specific gravity of approximately 1.5 to 2.2. On the other hand, the capture structure 1 according to the present invention is a structure mainly made of steel, with a specific gravity of approximately 7.85.

[0038] Furthermore, while the weight of conventional structures mainly made of sand, stone, and concrete is reduced by about half in water (a reduction of 67% to 45% as shown in Figure 9), the weight reduction of the present invention is only about 13%, resulting in a structure that is less affected by buoyancy.

[0039] Furthermore, considering the influence of water pressure, conventional structures are all block-shaped, and stability is ensured by stacking these individual structures as closely together as possible to form a wall. As a result, they are susceptible to the effects of water pressure, and when the force of the fluid flowing from the front becomes large, there is a possibility that the structure will collapse or be washed away. On the other hand, the capture structure 1 of the present invention has many voids, i.e., openings 3, in the unit itself, so the surface area on which water pressure acts is very small, and it has the characteristic of being able to dissipate the effects of external forces.

[0040] Furthermore, depending on the conditions of the installation location, the opening width of the opening 3 of the capture structure 1 may not be sufficient to capture the object. In such cases, the capture structure 1 is designed so that an opening width adjustment member 6 with a narrower opening width can be attached to the opening 3.

[0041] Figures 3, 4, and 5 show specific examples of the opening width adjustment member 6. As shown in Figure 3, the opening width adjustment member 6 can be made of a metal or synthetic resin material. The opening width of the opening width adjustment member 6 is narrower than the opening width of the capture structure 1, and by attaching this opening width adjustment member 6 to the rear interior side of the capture structure 1, the object to be captured can be kept in the space 2. Alternatively, as shown in Figures 4 and 5, the opening width adjustment member 6 may be made of a flexible rope or wire material. If the opening width adjustment member 6 is made of a rope or wire material, it can be easily attached to the rear interior side.

[0042] The trapping structure 1 according to the present invention is formed using a plate-shaped steel material having a grid-like opening 3. However, if only soil (fine-grained soil) significantly smaller than the vertical and horizontal spacing of the grid-like opening 3 flows down, it may pass through the opening 3 and the trapping function may not be performed.

[0043] Therefore, it can be said that the capture structure 1 according to the present invention directly satisfies the capture function for driftwood containing stones and gravel with a diameter of approximately half or more the vertical and horizontal opening spacing of the grid-like openings 3.

[0044] Furthermore, if the fine-grained sediment contains stones or driftwood, the fine-grained sediment is secondarily captured when the surface having the grid-like openings 3 is blocked by the stones and driftwood. Therefore, the prerequisite for the flow mode in which the present invention functions best is when a fluid containing stones or driftwood with a diameter larger than about half the vertical and horizontal spacing of the grid-like openings 3 flows down.

[0045] Furthermore, even without the aforementioned preconditions, the capture performance can be improved by installing the opening width adjustment member 6. This narrows the spacing of the openings 3, allowing for more efficient capture of fine-grained soil and sand.

[0046] Furthermore, in the case of the capture device 5 described later, a similar effect can be expected by laying capture structures 1 in parallel with each other in different positions where the opening 3 is formed (see Figure 11).

[0047] Next, we will describe an embodiment in which individual capture structures 1 are laid in parallel in the front-to-back and left-to-right directions, and stacked vertically, and used as a capture device 5 that can be connected to each other.

[0048] Figures 6 and 7 show an embodiment of the capture device 5. As can be seen from Figures 6 and 7, the capture device 5 is constructed by laying individual capture structures 1 in parallel in the front-to-back and left-to-right directions, and stacking them vertically. In Figures 6 and 7, the first layer consists of four capture structures 1 laid in the left-to-right direction and four rows laid in the front-to-back direction. The second layer consists of four capture structures 1 laid in the left-to-right direction and three rows laid in the front-to-back direction. The third layer consists of four capture structures 1 laid in the left-to-right direction and two rows laid in the front-to-back direction. The overall shape is a pyramidal shape, roughly triangular, as shown in Figures 6 and 7.

[0049] Furthermore, the external shape of the capture device 5 constructed according to the present invention is not limited to the pyramidal shape described above. For example, it may be formed in the shape of a right triangle, with one of its mountain-shaped inclined surfaces tilted to become the contact surface (Figure 12).

[0050] Furthermore, there are no restrictions on how many rows of the capture structure 1 of the present invention are laid out in the left, right, front, and rear directions, or how many layers are stacked in the vertical direction; this will be determined based on the conditions of the construction site.

[0051] Figure 6 shows a specific example of a trapping device 5 that can withstand debris flows, in which trapping structures 1 are laid in parallel in the front-to-back and left-to-right directions, stacked vertically, and connected to each other.

[0052] Conventional permeable trapping structures and older structures such as sandbags are all designed to have the function of accumulating sediment and other materials only on the upstream side of the structure.

[0053] However, as shown in the figure, the present invention is configured in a cage shape with multiple openings 3 on its side, so that flowing sediment and other debris can be retained within the space 2 of the capture structure 1 (see Figure 7). Therefore, it is a structure that can capture more flowing sediment and other debris compared to sandbag-type structures. This is particularly effective when the amount of flowing material is excessive compared to the capture capacity.

[0054] Figure 7 (bottom) shows the weight of one unit at each location before and after the model experiment of the present invention. As can be seen, the weight has increased by up to approximately twofold. In the present invention, the weight of the sediment remaining in the space 2 is added to the weight of the capture structure 1, which contributes to the stabilization of the entire capture device 5. Therefore, even if secondary runoff of sediment, gravel, driftwood, etc. occurs, the load-bearing capacity of the capture device 5 against the runoff of such secondary flowing material is improved, and a more robust capture device 5 can be provided that can withstand the runoff of sediment and other materials.

[0055] Furthermore, the present invention significantly improves driftwood capture performance by being permeable. That is, conventional sandbag-type structures lack or have low permeability, allowing driftwood and water to overflow from the left or right banks or from above. Therefore, lighter driftwood (such as fallen trees) risked being washed away with the overflowing water (see Figure 13(a)). On the other hand, the capture structure 1 of the present invention has the aforementioned space 2, thus possessing high permeability and water permeability. This allows for efficient separation of water and driftwood, resulting in high driftwood capture performance (see Figure 13(b)).

[0056] Furthermore, the trapping device 5 of the present invention can be easily used in combination with conventional sandbags and the like (see Figure 8), making it an extremely versatile structure.

[0057] Furthermore, conventional structures generally have a relatively low specific gravity and lack permeability, making them susceptible to unexpected loads from large amounts of soil and water, and increasing the likelihood of instability and collapse if the upper part of the structure is overflowed for extended periods. However, to address these concerns, as shown in Figure 8, by replacing all or part of the conventional structural devices with the present invention, it is possible to reliably improve the overall trapping and load-bearing performance of the structure while utilizing the conventional structural devices.

[0058] Furthermore, since the trapping structure of the present invention does not use any concrete, it has fewer time constraints for installation compared to conventional trapping structures for landslide prevention that use concrete. Also, as shown in Figure 9, since steel has a higher specific gravity than concrete, it occupies a smaller volume when compared at the same weight, making secondary use through removal and replacement easier, and it can be said to have excellent constructability and transportability.

[0059] (Summary of the present invention) The present invention is a "permeable trapping structure made of highly rigid steel material having a grid-like opening," and by "using plate-shaped steel material with a high specific gravity," it can be said that this trapping structure 1 is expected to have the effect of trapping soil, gravel, driftwood, etc., and improving load-bearing capacity against external forces exceeding expectations.

[0060] In other words, because it has "grid-like openings on the sides of the cube-shaped (polyhedral) structure," it cannot stop the flow of sediment that is significantly smaller than the aforementioned interval. However, this concern can be resolved by using an opening width adjustment member 6 made of netting or wire mesh in combination.

[0061] Furthermore, because it has a high specific gravity but a light weight, it may not have sufficient load-bearing capacity against impact loads such as rockfalls that do not involve water. However, this can be solved by lining the unit with anti-float members 4 such as steel plates.

[0062] Furthermore, while this invention alone can contribute significantly to mitigating landslides, combining it with conventional technologies increases the variety of considerations and allows for the design of more effective landslide prevention facilities. [Explanation of symbols]

[0063] 1 Capture structure 2 Space part 3 Opening 4. Anti-float member 5 Capture device 6. Opening width adjustment member 7. Thickness

Claims

1. It is made of steel that is formed into a polyhedron shape with a space inside, and has multiple openings formed on the surface of the faces that make up the polyhedron. A capture structure characterized by the following features.

2. The aforementioned polyhedron shape is a cube shape. The capture structure according to claim 1, characterized in that it is a feature of the present invention.

3. A floating prevention member is installed in the aforementioned space. The capture structure according to claim 1, characterized in that it is a feature of the present invention.

4. A capture structure made of steel, formed in a polyhedral shape with a space inside, and having multiple openings formed on the surfaces of the faces constituting the polyhedron, is installed inside a structure having an opening width narrower than the opening width of the openings. A capture structure characterized by the following features.

5. A capture structure made of steel, formed in a polyhedral shape with internal spaces and multiple openings formed on the surfaces of the faces constituting the polyhedron, can be arranged in parallel in the front-to-back and / or width-to-back directions, and can be stacked, with adjacent capture structures being connectable by connectors. A capture device characterized by the following.

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