JP5020267B2 - Steel structural material - Google Patents

Description

  The present invention relates to a steel structural material, and specifically relates to a technique for preventing water from staying in a steel structural material to enable reliable drainage and thus preventing corrosion of the structural material.

  Steel structures such as H-shaped steel are often used for sluices and bridges. When a bridge, a sluice, or the like is constructed by combining such structural materials, there may be a place where rainwater or the like is likely to accumulate depending on the shape of the structural material itself or the mounting relationship with other members. Therefore, a technique for draining water accumulated in such a place has been proposed.

  For example, with the object of providing a water drainage prevention structure for steel boxes, a drainage bolt attached to a drainage through hole formed in a plate and a drainage nut screwed to the drainage bolt Thus, a drain bolt / nut (see Patent Document 1), in which a series of drain channels are formed in the drain bolt and drain nut, has been proposed.

  In addition, as a technology that considers drain holes and drainage dredging structures, etc., the upper collar part that opens a plurality of drainage windows from the bottom of the wall part to the top, A drainage device for a road structure comprising a drainage basin formed by placing an upper collar part on a height adjustment spacer formed on a lower collar part and a lower collar part formed with a height adjustment spacer (Patent Document) 2) is also proposed.

JP 2006-299750 A JP 2005-248426 A

  As in the prior art, water drainage holes and various drainage devices may be provided in parts of the structural material that are less affected by stress, but the essential drainage openings are clogged with fallen leaves and other debris. In many cases, the location of the opening is inappropriate and water does not function as a drain hole.

  As for the location where the water has accumulated, the wet and dry with sunshine is repeated, and the coating film of the structural material is deteriorated and the steel material itself is likely to be corroded. Moreover, dirt or the like may be promoted on the structural material by clogging the drainage hole with dirt or the like. This sediment accumulation causes grass, moss, etc. to grow on the structural material, which has water retention properties and allows moisture to permeate into the structural material, thereby degrading the coating film of the structural material.

  On the other hand, sluices, bridges, and the like are often installed in places where personnel cannot easily approach such as high places and steep slopes, and the drainage mechanism such as the drain hole cannot be easily cleaned.

  Therefore, the present invention has been made in view of the above problems, and it is a main object to provide a technique for suppressing the retention of water in a steel structural material and enabling reliable drainage, and thus preventing the corrosion of the structural material. To do.

  The steel structural material of the present invention that solves the above problems can be used as an alternative to H-shaped steel used for, for example, sluices and bridge girders, and is roughly similar to H-shaped steel in shape. However, the steel structural material has a structure peculiar to the present invention in the web portion of the conventional H-shaped steel. That is, the steel structural material has a web portion in which a predetermined length of steel material having a cross-section of a mountain shape or an arc shape is aligned in a convex direction in the cross section and arranged in parallel at a predetermined interval, and the web portion It consists of an end face of each steel material and a fixed flange portion.

  In the steel structural material, a slit (= having a width corresponding to the predetermined interval) between a pair of steel members arranged in parallel at a predetermined interval is a facing distance between flange portions fixed to each end surface of the steel material Has a length of minutes. Therefore, even if obstructions such as dead leaves adhere to any part of the slit, drainage from other parts of the slit is not hindered, and water can be prevented from staying on the steel structural material. Of course, since the slit exists between the steel materials arranged in parallel, even if one slit is completely closed, the drainage from the other slit is maintained, and the water stays. Can also be prevented from spreading over a wide range of steel structural materials.

  Moreover, the said steel structure material is good also as providing the web part which arranged in parallel the steel material which aligned the direction of the convex direction in the said cross section toward the web part outer side at predetermined intervals.

  Further, the steel structural material of the present invention comprises a set of steel materials having a predetermined length with a cross-section of a mountain shape or an arc shape, with the convex directions in the cross-section facing each other at predetermined intervals. It is characterized by comprising a web part formed by arranging a set of steel materials in parallel in the extending direction of the steel structural material, and a flange part fixed to the end face of each steel material constituting the web part.

  ADVANTAGE OF THE INVENTION According to this invention, staying of the water in a steel structure material is suppressed, reliable drainage is attained, and the corrosion of a structure material can be prevented by extension.

It is a figure which shows Example 1 of the steel structure material of this embodiment. It is a figure which shows Example 2 of the steel structural materials of this embodiment. It is a figure which shows the analysis result 1 of the displacement and stress in this embodiment. It is a figure which shows the analysis result 2 of the displacement and stress in this embodiment. It is a figure which shows the analysis result 3 of the displacement and stress in this embodiment. It is a figure which shows the analysis result 4 of the displacement and stress in this embodiment.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram illustrating Example 1 of the steel structural member 100 of the present embodiment. The steel structural member 100 includes a web portion 50 and a flange portion 60 in the same manner as the H-shaped steel. Among them, the web portion 50 has a predetermined length (a length corresponding to the web height in the steel structural material) having a cross section of a mountain shape or an arc shape, and is aligned in a convex direction in the cross section. They are arranged in parallel at intervals. As the steel material 51, for example, an angle steel having a mountain-shaped cross section or a steel pipe having a circular cross section (see FIG. 1B) can be assumed. In addition, it is suitable if the direction of the convex direction in the cross section of the said steel material 51 is aligned toward the outer side of the web part 50, as shown in FIG.

  In the steel structural member 100, a slit 70 (= having a width corresponding to the predetermined interval) between a pair of steel members arranged in parallel at a predetermined interval is a flange portion fixed to each end face 52 of the steel member 51. It has a length corresponding to an opposing distance between 60 (= web height). Therefore, even if obstructions such as dead leaves adhere to any part of the slit 70, drainage from other parts of the slit 70 is not hindered and water is prevented from staying on the steel structural member 100. it can. Of course, the slit 70 exists between the steel members 51 arranged in parallel (in the example of the steel structural member 100 in FIG. 1, a total of five slits), so even one slit is completely closed. Even if it has been done, drainage from other slits is maintained, and it is possible to prevent water from staying over a wide area of the steel structural member 100.

  Further, the end surface 52 of each steel material 51 constituting the web portion 50 is fixed to the flange portion 60. For example, the angle steel as the steel material 51 is cut according to the web height (for example, a steel structural material is designed according to the required strength), and the end surface 52 of the flange portion 60 is configured. Fix to the steel plate by welding (submerged arc welding, etc.).

  In addition to the steel structural material 100 of the above-described form, a steel structural material 100 shown in FIG. 2 can be assumed. FIG. 2 is a view showing Example 2 of the steel structural member 100 of the present embodiment. In the case of this example, the web portion 50 of the steel structural member 100 is formed by arranging steel members 51 having a predetermined length whose cross section is a mountain shape or an arc shape at predetermined intervals in such a direction that the convex directions in the cross section face each other. One set is formed, and the one set of steel materials 51 is arranged in parallel in the extending direction of the steel structural material 100. In addition, as the said steel material 51, the cross-section angle steel (in the case of FIG. 2 (a)) or the steel pipe with a circular cross section (in the case of FIG. 2 (b)) can be assumed, for example. The end surface 52 of each steel material 51 constituting the web portion 50 is fixed to the flange portion 60 as in the case of FIG.

  In the case of the steel structural material 100 illustrated in FIG. 2A, the steel material 51 is an angle steel, and is arranged so as to face each other in a so-called “<” shape, and a slit 70 is provided between each steel material 51. Is provided. Further, the slits 71 may be provided between the backs of the “<” shape of the steel material 51. With such a slit arrangement, the drainage paths (= slits) in the steel structural member 100 are further dispersed, and the retention of water due to the obstructions that block the slits is suppressed, leading to reliable drainage.

  On the other hand, since it is the said steel structural material 100 which has a web shape different from normal H-shaped steel, it analyzed and verified whether the intensity | strength required as a structural material could be ensured. FIG. 3 is a diagram showing the analysis result 1 of displacement and stress in the present embodiment. Here, H-shaped steel (size: web height = 300 mm, flange width = 300 mm), first steel structural material 100 (size: flange width of the flange portion 60 = 300 mm, chevron forming the web portion 50, which is a comparison target 3 types of analysis target: steel 200 mm × 200 mm) and second steel structural member 100 (size: flange width of flange portion 60 = 300 mm, angle steel 100 mm × 100 mm constituting web portion 50) It was.

  As shown in FIG. 1 (a), the analysis is performed on the AA line of the flange portion 60 when a load of 100 kN is applied to the longitudinal center point of the flange portion 60 of the steel structural member 100. The displacement amount and the stress value at the point (the center point in the length direction of the flange portion 60) are calculated using an analysis program (existing one) of the displacement amount and the stress value such as an FEM analysis program.

  As a result of such analysis, the first steel structural member 100 has a maximum displacement (mm) of 1.26 times and a stress value of point B of 1.18 times compared to the H-shaped steel. . Further, the second steel structural member 100 was 1.36 times the maximum displacement (mm) and 1.23 times the stress value at the point B, compared with the H-shaped steel. Although it depends on the design strength required for the structural material, it can be said that the steel structural material 100 has a strength that does not cause any problem even if the steel structural material 100 is employed instead of H-shaped steel.

  As another analysis example, the same analysis as described above was performed by changing the plate thickness condition of the steel plate in the steel material 51. FIG. 4 is a diagram showing the analysis result 2 of displacement and stress in the present embodiment. Here, H-shaped steel (size: web height = 300 mm, flange width = 300 mm), first steel structural material 100 (size: flange width of the flange portion 60 = 300 mm, chevron forming the web portion 50, which is a comparison target Steel 200 mm × 200 mm, plate thickness t = 15 mm) and second steel structural member 100 (size: flange width of flange portion 60 = 300 mm, angle iron 200 mm × 200 mm constituting web portion 50, plate thickness t) = 20 mm)) was the analysis target.

  As a result of analysis under this condition, the first steel structural member 100 has a maximum displacement (mm) of 1.26 times that of the H-shaped steel, and a stress value at the point B of 1.18. Doubled. Further, the second steel structural member 100 was 0.95 times the maximum displacement (mm) and 0.88 times the stress value at the point B, compared with the H-shaped steel. From this result, in order to achieve the design strength required as a structural material, if the plate thickness of the steel material 51 of the web portion 50 in the steel structural material 100 is appropriately increased, it is used instead of the conventional H-shaped steel. Even so, it can be said that the steel structural material 100 has sufficient strength or higher.

  Further, as another analysis example, the same analysis as described above was performed by changing the condition of the web height of the web portion 50 (= the length of the steel material 51) in the steel material 51. FIG. 5 is a diagram showing an analysis result 3 of displacement and stress in the present embodiment. Here, H-shaped steel (size: web height = 300 mm, flange width = 300 mm), first steel structural material 100 (size: flange width of the flange portion 60 = 300 mm, chevron forming the web portion 50, which is a comparison target Steel 200 mm × 200 mm, angle steel 300 mm long) and second steel structural member 100 (size: flange width of flange portion 60 = 300 mm, angle steel 200 mm × 200 mm constituting web portion 50, angle steel) Of 350 mm in length) were analyzed.

  As a result of analysis under this condition, the first steel structural member 100 has a maximum displacement (mm) of 1.26 times that of the H-shaped steel, and a stress value at the point B of 1.18. Doubled. In addition, the second steel structural member 100 was 1.02 times the maximum displacement (mm) and 1.01 times the stress value at the point B, compared with the H-shaped steel. From this result, in order to achieve the design strength required as a structural material, if the web height of the web portion 50 in the steel structural material 100, that is, the length of the steel material 51 is appropriately long, the conventional H It can be said that the steel structural material 100 has almost the same strength as that of the mold steel.

  Furthermore, as another analysis example, the same analysis as described above was performed on the steel structural member 100 in which the web portion 50 was configured by arranging the angle steels so as to face each other in the so-called “ku” shape illustrated in FIG. . FIG. 6 is a diagram showing the analysis result 4 of displacement and stress in the present embodiment. Here, H-shaped steel (size: web height = 300 mm, flange width = 300 mm), steel structural material 100 (size: flange width of flange portion 60 = 300 mm, angle iron 200 mm constituting the web portion 50) 200 mm), were the analysis targets.

  As a result of analysis under this condition, the steel structural member 100 is 1.04 times the maximum displacement (mm) and 1.06 times the stress value at the point B as compared with the H-shaped steel. It was. From this result, it can be said that the steel structural member 100 has almost the same strength as the conventional H-shaped steel.

  As described above, if a sluice, a bridge, or the like is constructed using the steel structural member 100 having the same strength as that of the conventional H-shaped steel, the required strength is sufficiently secured and the slits 70 and 71 are formed. Even if obstructions such as dead leaves adhere to any part of the above, drainage from other parts of the slit is not hindered and water can be prevented from staying on the steel structural material. Since the slits exist between the steel members 51 arranged in parallel, even if one slit is completely blocked, the drainage from the other slit is maintained and the water is retained. However, it is possible to prevent the steel structural member 100 from reaching a wide range. That is, the cleaning work of drain holes and drainage devices, which was necessary in the prior art, is unnecessary for a long period of time, and it is less likely to force personnel to perform dangerous work in high places or steep slopes. Further, as described above, the steel structure material 100 can continue the natural drainage through the slits, and can suppress the steel material corrosion of the steel structure material itself and prevent the thickness of the steel structure material from decreasing.

  Therefore, according to the present embodiment, water can be prevented from staying in the steel structural material and reliable drainage can be performed, and thus corrosion of the structural material can be prevented.

  As mentioned above, although embodiment of this invention was described concretely based on the embodiment, it is not limited to this and can be variously changed in the range which does not deviate from the summary.

50 Web part 51 Steel material 52 End face 60 (of steel material) Flange part 70 Slit 100 Steel structure material

Claims (3)

  A web portion in which a predetermined length of steel material having a cross-section of a mountain shape or an arc shape is aligned in a convex direction in the cross section and arranged in parallel at a predetermined interval, and a flange fixed to an end surface of each steel material forming the web portion Steel structural material consisting of parts.   The steel structure material according to claim 1, further comprising a web portion in which steel materials in which the convex direction in the cross section is aligned toward the outside of the web portion are arranged in parallel at a predetermined interval.   A steel material of a predetermined length whose cross section is a mountain shape or a circular arc shape is arranged at a predetermined interval in a direction in which the convex directions in the cross section face each other, forming a set, and the set of steel materials is an extension direction of the steel structural material A steel structural material comprising: a web portion arranged in parallel to each other; and an end face of each steel material forming the web portion and a fixed flange portion.

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