JP2013023998A - Load bearing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load bearing material which has a high bearing force under flexural moment.SOLUTION: A load bearing material includes a metal outer pipe 2 having a circular cross section, and a plurality of inner steel pipes 3 and 3A each having a circular cross section and arranged in the outer pipe 2. A curable filler 5 fills the space between the inner surface 21 of the outer pipe 2 and the outer surfaces of the inner steel pipes 3 and 3A. The inner steel pipe 3 is arranged at the center of the outer pipe 2. The inner steel pipes 3A are arranged around the central inner steel pipe 3. The insides of the peripheral inner steel pipes 3A are filled with the curable filler 5. The bearing force is enhanced by the inner steel pipes 3 and 3A. Furthermore, the filler 5 filling the peripheral inner steel pipes 3A is restrained by the inner steel pipe 3A having a diameter smaller than that of the outer pipe 2, so that the flexural moment generates from the load, and the filler 5 resists to the compressive force applied to a cross sectional compressive region. Consequently the bearing force under the flexural moment can be enhanced.

Description

  The present invention relates to a load bearing material.

  Conventionally, protective structures have been known to use this type of load-bearing material. For protective structures such as falling rocks, avalanches, and collapsible sediments, pillars are provided at predetermined intervals. A protective fence (for example, Patent Document 1) that is provided with a horizontal rope material between the support posts and shielded between the support posts by a wire net and is made of concrete or metal between the support posts. In protective fences with multiple ridges and protective fence posts that are erected on the slope at a predetermined interval and stretch the protective net, the lower end of the pillar is placed on the slope, and the anchor provided on the slope A guard fence (for example, Patent Document 2) that uses a strut that is positioned by connecting a lower portion of the strut with an installation rope, or a suspension that connects the anchor and the upper and lower portions of the strut with an installation rope. Fence-type protective fence (for example, special Document 3) and the like are known, steel is used for the said post.

  In addition, a retaining wall formed on the slope, a main structural member that penetrates the retaining wall and is inserted into a natural ground, and supports a portion protruding from the retaining wall in a cantilever manner, and a main structural member that protrudes from the retaining wall There is a protective structure (for example, Patent Document 4) configured by a floor slab provided between members, and a steel pipe is used as the main structural material.

  As described above, steel pipes are used for the members of the protective structure. Furthermore, in the struts of the rock fall prevention fence, an uncoil type PC steel material covered with a sheath material is arranged, and concrete is placed in the steel pipe. There are known ones manufactured by filling (for example, Patent Document 5), and those in which double steel pipes are filled with a filler, and cement milk or mortar is used as the filler (for example, Patent Document 6). ing.

  Furthermore, as a pillar of a building such as a high-rise building, a gap between the outer steel pipe and the inner steel pipe and a filled steel pipe structure filled with concrete inside the inner steel pipe (for example, Patent Document 7), between the outer steel pipe and the inner steel pipe, and A concrete important steel pipe column (for example, Patent Document 8) formed by filling concrete in an inner steel pipe is known.

  As in the above-mentioned patent document, in a filled steel pipe filled with a filler such as concrete, the rigidity can be improved as compared with a hollow steel pipe.

JP-A-6-173221 JP 2000-248515 A (paragraph 0013) JP-A-8-184014 JP 2001-323416 A JP-A-6-146225 JP-A-9-203036 JP 2003-313950 A JP 2002-227302 A

  When a filled steel pipe as described above receives a load such as impact force and distortion occurs due to a bending moment, deformation in the cross section is difficult to occur. On the cross section side where compressive force is generated, concrete having high compressive stress relative to the compressive force. However, it has secured the strength. However, in conventional double steel pipes consisting of an external steel pipe and an internal steel pipe, if the concrete is filled in the gap between the external steel pipe and the internal steel pipe and the inside of the internal steel pipe, the compressive strength of the concrete can be improved. Therefore, it cannot be said that the structure is sufficiently utilized, and a structure that effectively improves the yield strength of the bending moment by filling with a filler such as concrete is desired.

  Therefore, an object of the present invention is to provide a load-bearing material having a high yield strength against a bending moment.

  (1) The present invention includes a metal outer tube having a circular cross section and a plurality of metal inner tubes having a circular cross section disposed in the outer tube, and the space between the inner surface of the outer tube and the outer surface of the inner tube. In a load-bearing material filled with a curable filler, an inner tube is arranged at the center of the outer tube, a plurality of inner tubes are arranged around the central inner tube, and a curable mold is placed inside these surrounding inner tubes. It is characterized by being filled with a filler.

  According to the above configuration, the proof stress is improved by the plurality of inner pipes, and the filler filled in the surrounding inner pipes is restrained by the inner pipe having a smaller diameter than the outer pipes. When a compressive force is applied to the cross-section compression region, the filler constrained by the surrounding inner tube opposes the compressive force, thereby improving the resistance to bending moment.

  (2) Further, the present invention is characterized in that a plurality of inner tubes are arranged concentrically around the central inner tube.

  According to the above configuration, a combination of the outer tube having a circular cross section, the central inner tube, and the peripheral inner tubes arranged concentrically around the central inner tube has substantially uniform strength in all directions. It becomes.

  (3) Further, the present invention is characterized in that a tensile strength of the surrounding inner pipe is higher than that of the central inner pipe.

  According to the said structure, the yield strength with respect to a bending moment can be improved because the internal pipe of the tension | pulling area | region side opposes. Moreover, the binding force of the concrete by the surrounding internal pipe can be increased.

  (4) Further, the present invention is characterized in that the surrounding inner tube is thicker than the central inner tube.

  According to the above configuration, the tensile strength of the surrounding inner tube can be improved.

  (5) Further, the present invention is characterized in that the compressive strength of the curable filler filled in the surrounding inner tube is higher than that of the central inner tube.

  According to the said structure, the yield strength with respect to a bending moment can be improved because the curable filler in an internal pipe opposes in the compression area | region side.

  (6) Further, the present invention is characterized in that the central inner tube has a larger diameter than the surrounding inner tube.

  According to the above configuration, in the large-diameter outer tube, the central inner tube is made large in diameter, so that the surrounding inner steel tube is arranged on the outer tube side of the cross section having high tensile stress and compressive stress, and these stresses are counteracted. can do.

  According to the above configuration, the proof stress is improved by the plurality of inner pipes, and the filler filled in the surrounding inner pipes is restrained by the inner pipe having a smaller diameter than the outer pipes. When a compressive force is applied to the cross-sectional compression region, a filler material constrained by the surrounding inner tube opposes this compressive force, thereby providing a load-bearing material having a high resistance to a bending moment. .

It is sectional drawing of Example 1 of this invention. It is a graph which shows the relationship between the bending moment and curvature of an implementation product same as the above. It is a graph which shows the relationship between the bending moment and curvature of a comparative product same as the above. It is sectional drawing of Example 2 of this invention. It is sectional drawing of Example 3 of this invention. It is sectional drawing of Example 4 of this invention. It is sectional drawing of Example 5 of this invention. It is sectional drawing of Example 6 of this invention. It is sectional drawing of Example 7 of this invention.

  Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below do not limit the contents of the present invention described in the claims. In addition, all of the configurations described below are not necessarily essential requirements of the present invention. In each embodiment, by using a new load bearing material different from the conventional one, an unprecedented load bearing material is obtained, and the load bearing material will be described.

  Embodiment 1 of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the load-bearing material 1 includes an outer tube 2 made of a steel tube, a plurality of metal inner tubes 3, 3A,... A mold filler 5 is provided. The inner steel pipe 3 is arranged at the center of the outer pipe 2, and a plurality of the surrounding inner steel pipes 3A are arranged so as to surround the center inner steel pipe 3, and in this example, the surrounding inner steel pipes 3A ... Are arranged concentrically, and the cross section shown in FIG. The concentric circle means that the virtual circle connecting the centers of the plurality of internal steel pipes 3A and the central internal steel pipe 3 form a concentric circle.

  In this example, the inner steel pipes 3, 3 </ b> A are all steel pipes having the same configuration and are generally thinner than the outer pipe 2. In the outer pipe, the inner steel pipes 3, 3A,... Are positioned by positioning means such as the spacer (not shown).

  The central inner steel pipe 3 has a circular cross section and has a hollow shape, and a plurality of the surrounding inner steel pipes 3A are arranged close to each other in a substantially hexagonal honeycomb shape, and the inner steel pipes 3A, 3A, 3A ... It arrange | positions so that the outer surface 31 of each other may contact | connect, and the surrounding internal steel pipe 3 may contact | connect the center internal steel pipe 3. Specifically, one inner steel pipe 3 is arranged at the center of the outer pipe 2, and six (even number) inner steel pipes 3A, 3A... Are in contact with the outer surface 31 of the inner inner steel pipe 3A. These six inner steel pipes 3A, 3A... Are adjacent to each other, and the cross section of the load bearing material 1 is point-symmetric. Therefore, the central inner steel pipe 3 is in contact with the six surrounding inner steel pipes 3A, 3A..., And the central inner steel pipe 3 is within a range surrounded by the six inner steel pipes 3A, 3A. To position.

  Further, a gap of 10 mm or less is provided between the outer surface 31 of the surrounding inner steel pipes 3A, 3A... And the inner surface 21 of the outer pipe 2, and the outer surface 31 of the surrounding inner steel pipes 3A, 3A. No contact with 21.

  Except for the inside of the central inner steel pipe 3, the inside of the load-bearing material 1 is filled with the curable filler 5 that hardens with time after filling. That is, the first filling space 6 between the inner surface 21 of the outer fitting 2 and the outer surface 31 of the inner steel pipes 3, 3A, 3A..., The second filling space 7 between the inner steel pipes 3, 3A, 3A. The inner steel pipes 3A, 3A... Are filled with a filler 5, and the central inner steel pipe 3 is not filled with the filler 5. Examples of the filler 5 include cement-based fillers. For example, non-shrink mortar, concrete and the like are used. In addition, various kinds of fillers may be used as long as they are solidified or determined in shape over time. Can do.

  In this case, since the central inner steel pipe 3 is on the neutral axis when bending stress is generated in the load bearing material 1, it is not necessary to fill the inside with the curable filler 5 from the aspect of increasing the strength. Reduction is possible. Of course, the central inner steel pipe 3 may be filled with the curable filler 5 or may be filled with the non-curable filler.

  Next, the proof stress of the implementation product based on an Example and a comparison product is demonstrated. The material used for the calculation will be described. In the embodiment shown in FIG. 1, the outer pipe 2 is a steel pipe having an outer diameter of 216.3 mm and a wall thickness of 10.3 mm, and the inner steel pipes 3 and 3A have an outer diameter of 60. The thickness is 5 mm, the wall thickness is 3.8 mm, and the filler is mortar. The comparative product is the same as the implemented product except that the surrounding internal steel pipe 3A is not filled with the filler 5. All steel pipes used STK400 (general structural carbon steel pipe).

  For the calculation of the column cross-sectional yield strength, the yield strength was calculated by the cross-section division method. In the product, the number of spaces surrounded by the inner steel pipes 3, 3A, 3A... (The number of second filling spaces 7) is 6, the average thickness of the filler 5 is 67.6 mm, and the radial direction of the filler 5 The number of divisions is 10 divisions. In the comparative product, the number of spaces surrounded by the inner steel pipes 3, 3A, 3A... Is 6, the average thickness of the filler 5 is 16.07 mm, and the number of divisions in the radial direction of the filler 5 is two. is there. In addition, both the implementation product and the comparison product were assumed to be 4.5 meters in length, and were set as the loading point at which a load was applied at the center.

  The reference bending strength used in the design is a smaller value by comparing the 90% value of the ultimate bending strength determined from the experimentally deformed state with the plasticity ratio εa / εy <5 determined from the strain of the steel pipe. Here, the allowable strain εa of the steel pipe is 5875 μ, and the yield strain εy of the steel pipe is 1175 μ.

  The results of the implementation and comparative products obtained by calculation are shown in FIGS. 2 and 3, respectively. These FIGS. 2 and 3 are graphs in which the vertical axis represents the bending moment and the horizontal axis represents the load-bearing material curvature. Yes, it can be seen that the product has a large proportional range and high proof stress. The actual product has a maximum bending moment of about 250 kN-m, while the comparative product has a maximum bending moment of about 165 kN-m. Simply inserting the filler 5 into the six inner steel pipes 3A Became 1.5 times.

  As described above, the present embodiment includes the metal outer tube 2 having a circular cross section and the inner steel pipes 3 and 3A, which are a plurality of metal inner tubes having a circular cross section, disposed in the outer tube 2. In the load bearing material filled with the curable filler 5 between the inner surface 21 and the outer surface of the inner steel pipe 3, 3 </ b> A, the inner steel pipe 3 is disposed at the center of the outer pipe 2, and the inner inner steel pipe 3 is surrounded by a plurality of Since the internal steel pipes 3A are arranged and the inside of these surrounding internal steel pipes 3A is filled with the hardening type filler 5, the proof stress is improved by the plurality of internal steel pipes 3 and 3A, and the surrounding internal steel pipes 3A are filled. Since the filler 5 is constrained by the inner steel pipe 3A having a diameter smaller than that of the outer pipe 2, a bending moment is generated by receiving a load, and when a compressive force is applied to the cross-sectional compression region, The filler 5 constrained by the steel pipe 3A opposes the bending It is possible to improve the resistance against Mento.

  In this way, in this embodiment, since the plurality of internal steel pipes 3A as inner pipes are concentrically arranged around the inner steel pipe 3 as the central inner pipe, the outer pipe 2 having a circular cross section and the central inner steel pipe 3 are arranged. And a combination of the inner steel pipe 3A and the surrounding inner steel pipe 3A arranged concentrically around the center inner steel pipe 3 have substantially uniform strength in all directions.

  Further, as an effect of the embodiment, since the central inner steel pipe 3 positioned at the neutral axis when bending stress is generated does not fill with the curable filler 5, the material cost can be reduced.

  FIG. 4 shows a second embodiment of the present invention. The same reference numerals are given to the same portions as those of the first embodiment, and detailed description thereof is omitted. In this example, compared to the central inner steel pipe 3, FIG. The thickness of the six surrounding inner steel pipes 3A is set to be large, and the inner steel pipes 3 and 3A are made of the same material. Therefore, the surrounding inner steel pipe 3A has higher strength and higher tensile strength than the central inner steel pipe 3. . In particular, since the steel pipe has higher tensile strength than the curable filler 5 such as mortar, the proof stress in the tensile region of the load bearing material 1 can be improved.

  As described above, in this embodiment, the same operations and effects as those of the first embodiment are obtained.

  As described above, in this embodiment, the tensile strength of the inner steel pipe 3A, which is a peripheral inner pipe, is higher than that of the inner steel pipe 3, which is the central inner pipe. In addition, it is possible to increase the binding force of the concrete by the surrounding inner steel pipe 3A, thereby improving the proof stress against the compressive force.

  In this way, in this embodiment, since the inner steel pipe 3A, which is the surrounding inner pipe, is thicker than the inner steel pipe 3A, which is the central inner pipe, the tensile strength of the surrounding inner steel pipe 3A can be improved.

  FIG. 5 shows a third embodiment of the present invention. The same reference numerals are given to the same portions as those of the above-described embodiments, and detailed description thereof will be omitted. In this example, in the first and second filling spaces, FIG. The filler 5A having a higher compressive strength than the fillers 6 and 7 is filled in the surrounding inner steel pipe 3A.

  As described above, in this embodiment, the same operations and effects as the above-described embodiments are obtained.

  As described above, in this embodiment, the compressive strength of the curable filler 5A filled in the inner steel pipe 3A as the surrounding inner pipe is higher than the compressive strength of the curable filler 5 filled in the inner steel pipe 3 as the central inner pipe. Since it is high, the proof filling material 5A in the inner steel pipe 3A opposes on the compression region side, whereby the yield strength against the bending moment can be improved.

  In the second embodiment, the surrounding inner steel pipe 3 may be filled with a filler 5A having a higher compressive strength than the filler 5 in the first and second filling spaces 6 and 7, in this case. Furthermore, the proof stress of the load bearing material 1 can be improved.

The inner steel pipe at the center does not touch the strength of the larger diameter than the surroundings.
FIG. 6 shows a fourth embodiment of the present invention. The same reference numerals are given to the same parts as those of the above-described embodiments, and detailed description thereof will be omitted. In this example, the outer tube 2 is more than the first embodiment. The diameter of the center inner steel pipe 3B is larger than the diameter of the surrounding inner steel pipe 3A, and the surrounding inner steel pipe 3A is arranged on a concentric circle of the center inner steel pipe 3B. The central inner steel pipe 3B is not filled with a filler. That is, the fifth filling space 6A between the inner surface 21 of the outer tube 2 and the outer surface 31 of the surrounding inner tube 3A, and the fifth space between the outer surface 31 of the surrounding inner tube 3A and the outer surface of the central inner steel tube 3B. The filler 5 is filled in the filling space 7A and the inside of the surrounding inner steel pipe 3A.

  As described above, in this embodiment, the same operations and effects as the above-described embodiments are obtained.

  In this way, in this embodiment, the inner steel pipe 3B, which is the central inner pipe, has a larger diameter than the inner steel pipe 3A, which is the surrounding inner pipe. By making it, it can arrange | position the surrounding inner steel pipe 3A to the outer pipe 2 side of a cross section with high tensile stress and compressive stress, and can counter these stresses.

  Further, as an effect of the embodiment, since the central inner steel pipe 3B is not filled with the filler, the material cost can be reduced. Further, since the outer diameter of the inner steel pipe 3B is 1/2 or more of the outer diameter of the outer pipe 2, the surrounding inner steel pipe 3A is arranged on the outer pipe 2 side of the cross section having high tensile stress and compressive stress, and the bending moment is increased. The proof stress can be improved.

  FIG. 7 shows a fifth embodiment of the present invention. The same reference numerals are given to the same portions as those of the above-described embodiments, and detailed description thereof will be omitted. In this embodiment, the first embodiment is the same as the first embodiment. The filler 5A having higher compressive strength than the filler 5 in the fourth and fifth filling spaces 6A and 7A is filled in the surrounding inner steel pipe 3A.

  Further, similarly to the first embodiment, it is not necessary to fill the portion in the central inner steel pipe 3B with the curable filler 5, and the material cost can be reduced. Of course, the central inner steel pipe 3 may be filled with the curable filler 5 or may be filled with the non-curable filler.

  As described above, in this embodiment, the same operations and effects as the above-described embodiments are obtained.

  Further, in this example, since the compressive strength of the curable filler 5A filled in the inner steel pipe 3A as the surrounding inner pipe is higher than the curable filler 5 filled in the inner steel pipe 3 as the central inner pipe, The proof filling material 5A in the inner steel pipe 3A opposes on the compression region side, whereby the yield strength against the bending moment can be improved.

  FIG. 8 shows a sixth embodiment of the present invention. The same reference numerals are assigned to the same parts as those of the above-described embodiments, and the detailed description thereof is omitted. The small inner steel pipe 3 is arranged inside 3B, and a space between the inner steel pipes 3 and 3B is a third filling space 8, and the third filling space 8 is also filled with the filler 5.

  Therefore, a triple steel pipe is constituted by the central inner steel pipe 3, the inner steel pipe 3 </ b> B, and the outer pipe 2 that form concentric circles, and the inner steel pipe 3 </ b> A is disposed between the inner steel pipe 3 </ b> B and the outer pipe 2.

  As described above, in this embodiment, the same operations and effects as the above-described embodiments are obtained.

  As described above, in this embodiment, the proof stress is improved by the filler 5 filled in the third filling space 8, and in particular, the proof strength against the compressive stress generated by the bending moment is further improved.

  Further, as an effect on the embodiment, if the compressive strength of the filler 5A filled in the surrounding inner steel pipe 3A is made higher than the compressive strength of the other fillers 5, the filler 5A in the inner steel pipe 3A becomes a compressive force. It can counteract and improve bending strength.

  FIG. 9 shows a seventh embodiment of the present invention. The same reference numerals are given to the same portions as those of the above-described embodiments, and detailed description thereof will be omitted. A surrounding internal steel pipe 3A is arranged between the steel pipes 3 and 3B.

  As described above, in this embodiment, the same operations and effects as those of the above-described embodiments can be obtained. In this embodiment, the surrounding inner steel pipes 3A disposed between the outer pipe 2 and the inner steel pipe 3B, and the inner steel pipe 3B. , 3 and the surrounding inner steel pipes 3A ... and the filler 5 can provide the load-bearing material 1 having excellent bending strength.

  Further, as an effect on the embodiment, the inner steel pipe 3A around the large-diameter inner steel pipe 3B is filled with a filler 5A having a higher compressive strength than the other, or the inner steel pipe 3A around the large-diameter inner steel pipe 3B and If the inner steel pipe 3A around the central inner steel pipe 3 is filled with a filler 5A having a higher compressive strength than others, the filler 5A having a higher compressive strength is constrained by the inner steel pipe 3A. It is possible to provide the load-bearing material 1 having a high yield strength.

  In addition, this invention is not limited to the said Example, A various deformation | transformation is possible within the range of the summary of this invention. For example, in the examples, steel pipes are used for the outer pipe and the inner pipe. However, the outer pipe and the inner pipe may be made of various metals other than iron, aluminum, stainless steel, or alloys thereof. Can be used. Moreover, the outer surface of the outer pipe does not necessarily have to be exposed. For example, the load resistant material of the present invention may be used for the steel pipe inside the double steel pipe. Furthermore, the load-bearing material of the present invention can be used as a material for various structures other than the beam members of the protective structure columns such as rock fall, avalanche and collapsed earth and sand described in the background art.

1 Load-bearing material 2 Outer pipe
21 Inner surface 3 Internal steel pipe (central inner pipe)
3A internal steel pipe
31 Outer surface 3B Large diameter inner steel pipe 5 Hardening filler 5A Hardening filler

Claims (6)

A metal outer tube having a circular cross section and a plurality of metal inner tubes having a circular cross section disposed in the outer tube, and a curable filler is filled between the inner surface of the outer tube and the outer surface of the inner tube. In the above load-bearing material, an inner tube is disposed at the center of the outer tube, a plurality of inner tubes are disposed around the inner tube, and a curable filler is filled in the surrounding inner tube. A featured load-bearing material. The load-bearing material according to claim 1, wherein a plurality of inner pipes are arranged concentrically around the central inner pipe. The load-bearing material according to claim 1 or 2, wherein the tensile strength of the surrounding inner pipe is higher than that of the central inner pipe. 4. The load-bearing material according to claim 3, wherein the surrounding inner tube is thicker than the central inner tube. The load-bearing material according to claim 1 or 2, wherein the compressive strength of the curable filler filled in the surrounding inner tube is higher than that of the central inner tube. The load-bearing material according to claim 1, wherein the central inner pipe has a larger diameter than the surrounding inner pipe.

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