Design method for roof member joint structure

Abstract

To efficiently improve lateral buckle strength of a beam with reduced construction cost.SOLUTION: A design method for a roof member joint structure between an H-shaped steel beam as a support member and a roof member, having the roof member joined to the H-shaped steel beam with first joint parts that are arranged in the longitudinal direction of the H-shaped steel beam and with second joint parts that have higher rigidity and strength than the first joint part, comprises: a process to derive by analysis a lateral-buckling waveform of the H-shaped steel beam upon assumption that the roof member is joined to the H-shaped steel beam only with the first joint part; a process to determine positions of relative maximum values of out-of-plane deformations in the lateral-buckling waveform; and a process to replace the first joint part with the second joint part at the position of the relative maximum value of the out-of-plane deformation.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for designing a joint structure of a roof member. [Background technology]

[0002] Dry roof structures are known in which roofing components, such as corrugated deck plates, are placed on purlins. For example, Patent Document 1 describes a technique in which purlins are attached to the underside of a deck plate to form the roof body, and the purlins are then attached to fire-resistant beams of a building. In the technique described in Patent Document 1, drilling and tapping screws are used to join the deck plate and the purlins. Other joints that can be used include burn-through plug welding and riveted rivets. Patent Document 2 proposes a technique in which a plate-like member is inserted between the deck plate and a nut that is threaded onto a stud bolt that extends through the deck plate from the opposite side of the support member, in order to form a friction joint between the deck plate and the support member that exhibits stable rigidity and strength while maintaining workability.

[0003] On the other hand, as described in Non-Patent Document 1, for example, a technique is known in which floor slabs, roof panels, etc. are continuously attached in the longitudinal direction of the beam to exert a restraining effect against lateral buckling deformation and improve the lateral buckling strength of the beam. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-282190 [Patent Document 2] Japanese Patent Publication No. 2022-127322 [Non-patent literature]

[0005] [Non-Patent Document 1] Yoshihiro Kimura et al., "Lateral Buckling Load of H-Shaped Beams with Continuous Bracing on the Top Flange Subjected to Inclined Bending Moment and Compressive Axial Force and the Effect of Continuous Bracing on Horizontal and Rotational Restraint," Journal of Structural Engineering, Architectural Institute of Japan, Vol. 82, No. 741, pp. 1799-1809, November 2017 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, when connecting roof elements to H-shaped steel beams via multiple joints to prevent lateral buckling of the beams, the rigidity of the joints is important. For example, if the joints are only made with burn-through plug welds, localized deformation occurs in the roof elements, making it difficult to ensure rotational rigidity. This raises the risk of insufficient suppression of lateral buckling of the beams. For example, using joints with improved rigidity and strength, such as those described in Patent Document 2, would strengthen the restraint effect against lateral buckling, but using such joints for all joints would significantly increase construction costs.

[0007] Therefore, an object of the present invention is to provide a method for designing a joint structure of roof members that can efficiently improve the lateral buckling strength of beams while reducing construction costs. [Means for solving the problem]

[0008] [1] A design method for a joint structure between an H-shaped steel beam, which is a supporting member, and a roof member, wherein the roof member is joined to the H-shaped steel beam by a first joint arranged in the longitudinal direction of the H-shaped steel beam and a second joint having higher rigidity than the first joint, the design method comprising the steps of: analytically deriving a lateral buckling waveform of the H-shaped steel beam assuming that the roof member is joined to the H-shaped steel beam only by the first joint; identifying the position of the maximum out-of-plane deformation in the lateral buckling waveform; and replacing the first joint with the second joint at the position of the maximum out-of-plane deformation. [2] A method for designing a connection structure between an H-shaped steel beam, which is a supporting member, and a roof element, wherein the roof element is joined to the H-shaped steel beam by a first joint arranged in the longitudinal direction of the H-shaped steel beam and a second joint having higher rigidity than the first joint, and the roof element is constituted by deck plates having one or more uneven shapes arranged so that the extension direction of the uneven shapes is perpendicular to the longitudinal direction of the H-shaped steel beam, the method comprising the steps of: analytically deriving a lateral buckling waveform of the H-shaped steel beam assuming that the roof element is joined to the H-shaped steel beam only by the first joint; identifying the position of the maximum out-of-plane deformation in the lateral buckling waveform; and replacing at least one of the first joints of the first deck plate corresponding to the position of the maximum out-of-plane deformation with the second joint. [3] A design method for a joint structure of a roof member described in [2], wherein the first joint and the second joint are refractory plug welds provided in a recess of the first deck plate, and the rigidity of the second joint is increased by increasing the number of refractory plug welds. [Effects of the Invention]

[0009] According to the above configuration, in a roof member joint structure in which a roof member is joined to an H-shaped steel beam by multiple joints arranged in the longitudinal direction of the H-shaped steel beam, it is possible to appropriately determine the positions of the joints with high rigidity and strength. This makes it possible to avoid positions where stiffening effect is not expected, reduce construction costs, and efficiently improve the lateral buckling strength of the H-shaped steel beam. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a joining structure for roof members according to one embodiment of the present invention. [Figure 2] 1 is a plan view of a joining structure for roof members according to an embodiment of the present invention; [Figure 3] 1 is a flowchart of a method for designing a joint structure of a roof member according to one embodiment of the present invention. [Figure 4]FIG. 10 is a schematic diagram illustrating the arrangement of joints in a model of an H-shaped steel beam used in an eigenvalue analysis. [Figure 5] FIG. 1 is a schematic diagram showing an example of a lateral buckling waveform of an H-shaped steel beam obtained by eigenvalue analysis. [Figure 6] 1 is a graph showing an example of an analysis result of the lateral buckling waveform of an H-shaped steel beam. [Figure 7] FIG. 10 is a diagram illustrating the position of a first deck plate when multiple deck plates are arranged. [Figure 8A] FIG. 10 is a diagram showing an example of the arrangement of second joints in the corresponding deck plate. [Figure 8B] FIG. 10 is a diagram showing an example of the arrangement of second joints in the corresponding deck plate. [Figure 8C] FIG. 10 is a diagram showing an example of the arrangement of second joints in the corresponding deck plate. [Figure 8D] FIG. 10 is a diagram showing an example of the arrangement of second joints in the corresponding deck plate. [Figure 8E] FIG. 10 is a diagram showing an example of the arrangement of second joints in the corresponding deck plate. [Figure 9] 10 is a graph showing the analysis results illustrating the effect of providing one second joint portion. [Figure 10] 10 is a graph showing the analysis results illustrating the effect of providing two second joints. [Figure 11] FIG. 10 is an enlarged perspective view of a second joint portion of the joint structure of the roof member. [Figure 12A] FIG. 11 is a cross-sectional view taken along line AA in FIG. [Figure 12B] FIG. 11 is a cross-sectional view taken along line BB in FIG. [Figure 12C] FIG. 11 is a cross-sectional view taken along line CC in FIG. [Figure 13] FIG. 10 is a diagram showing a modified example of an embodiment of the present invention. [Figure 14] FIG. 10 is a diagram showing a modified example of an embodiment of the present invention. [Figure 15] FIG. 10 is a diagram showing a modified example of an embodiment of the present invention. [Figure 16]FIG. 10 is a diagram showing an example of a tight frame in which the rigidity is increased only in a part of the frame. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0012] The design method for a joint structure of a roof member of the present invention is a design method for a joint structure between an H-shaped steel beam, which is a supporting member, and a roof member. The roof member in the present invention is joined to the H-shaped steel beam by a first joint arranged in the longitudinal direction of the H-shaped steel beam and a second joint arranged partially and having higher rigidity than the first joint. The present invention is a method for determining the position of the second joint, which is arranged partially to improve the lateral buckling strength of the H-shaped steel beam, in the above-mentioned joint structure of a roof member.

[0013] First, an example of a joint structure of roof members designed by the design method of this embodiment will be described. Figure 1 is a cross-sectional view of the joint structure of roof members according to one embodiment of the present invention, and Figure 2 is a plan view of the joint structure of roof members. As shown in Figures 1 and 2, the roof member joint structure 100 is a joint structure between an H-shaped steel beam 2, which is a support member, and a deck plate 1, which is an example of a roof member, and the deck plate 1 is joined to the H-shaped steel beam 2 by a plurality of joints N1 to N13 arranged in the longitudinal direction (x direction) of the H-shaped steel beam 2.

[0014] The deck plate 1 is a corrugated thin plate with alternating trapezoidal convex portions 11 and concave portions 12 extending parallel to one another, creating an uneven shape, and is arranged so that the direction of extension of the concave and convex portions is perpendicular to the length direction of the H-shaped steel beam 2. The thickness of the deck plate 1 is, for example, 0.8 mm to 1.6 mm, but is not limited to this example. Multiple deck plates 1 may be laid side by side in the length direction or width direction of the H-shaped steel beam 2.

[0015] The H-shaped steel beam 2 includes flanges 21A, 21B and a web 22. In the illustrated example, the recess 12 of the deck plate 1 is placed on the surface of the flange 21A opposite to the web 22. The x direction shown in each figure is the direction of the corrugation of the deck plate 1 (which coincides with the axial direction of the H-shaped steel beam 2), the y direction is the direction perpendicular to the x direction in the horizontal plane (which coincides with the width direction of the H-shaped steel beam 2), and the z direction is the vertical direction.

[0016] A plurality of (13 in this embodiment) joints N1 to N13 are arranged at approximately equal intervals in the longitudinal direction of the H-shaped steel beam 2. The joints N1 to N13 are composed of first joints (N1 to N3, N5 to N9, and N11 to N13 in this embodiment) and second joints (N4 and N10 in this embodiment) that have higher rigidity than the first joints.

[0017] 1 and 2, the first joints N1 to N3, N5 to N9, and N11 to N13 are formed by one burnt plug weld per joint between the recess 12 of the deck plate 1 and the flange 21A. The second joints N4 and N10 have higher rigidity than the first joints by increasing the number of burnt plug welds per recess 12. The second joints in this embodiment are formed by two burnt plug welds.

[0018] At the second joints N4 and N10, the number of times the above-mentioned burn-out plug welding is performed is large, so the construction cost per location is higher than the construction cost per location of the first joint. Therefore, by partially arranging the second joints as described above and using the first joints for the rest, the construction cost of the entire joint structure can be reduced. As will be shown in the examples described below, by using joints N4 and N10 as second joints, the lateral buckling of the H-shaped steel beam 2 can be effectively restrained.

[0019] [Method for designing joint structure] Next, a method for designing the joint structure of the roof members will be described. As described above, the design method for the joint structure of a roof member is a method for determining the position of a second joint that is partially placed to improve the lateral buckling strength of an H-shaped steel beam. As shown in Figure 3, the design method for the joint structure of a roof member includes a lateral buckling waveform derivation step S1 for deriving the lateral buckling waveform of the H-shaped steel beam through analysis, a maximum value identification step S2 for identifying the position of the out-of-plane deformation maximum value in the derived lateral buckling waveform, and a replacement step S3 for replacing the first joint with the second joint at the position of the out-of-plane deformation maximum value.

[0020] [Transverse buckling waveform derivation process] In the lateral buckling waveform derivation step S1, the lateral buckling waveform of the H-shaped steel beam is derived by eigenvalue analysis, assuming that the roof element is connected to the H-shaped steel beam only by the first joint. That is, as a preliminary step to determining the position of the second joint, which has higher rigidity than the first joint, the lateral buckling waveform of the H-shaped steel beam is derived using a model of the H-shaped steel beam in which all joints are first joints. An example of the analysis conditions for the eigenvalue analysis is shown below.

[0021] [Analysis conditions] H-shaped steel beam: height 300mm x width 150mm, web thickness 6.5mm, flange thickness 9mm H-beam length: 7800mm Continuous stiffening: 600mm pitch Horizontal spring: 72.6kN / mm Rotational stiffness of the first joint: 11.3 kNm / rad

[0022] Figure 4 is a schematic diagram explaining the arrangement of joints in an H-shaped steel beam model used in eigenvalue analysis. As shown in Figure 4, the H-shaped steel beam model is a model in which 13 deck plates 1, arranged at equal intervals on an H-shaped steel beam 2, are each joined at joints N1 to N13. The rotational rigidity of the first joint is an experimental value determined by an experiment in which the H-shaped steel beam and deck plate were welded together using burnt plug welding, and then a torsion was applied to the H-shaped steel beam to confirm the rotational rigidity of the joints provided on each of the deck plates. The horizontal springs are set in the same locations as the first joint, and in this analysis, the value is calculated by multiplying Young's modulus E by the cross-sectional area A per width of the deck plate and dividing it by the deck length typically used in buildings (for example, beam center distance L = 3000 mm).

[0023] Fig. 5 is a schematic diagram showing an example of the lateral buckling waveform of the H-shaped steel beam 2 obtained by eigenvalue analysis. In the example shown in Fig. 5, the lateral buckling waveform of the H-shaped steel beam 2 is in the secondary buckling mode for both the top flange and the bottom flange, and the nodes are at both ends and the middle part of the H-shaped steel beam 2.

[0024] [Maximum value identification process] In the maximum value identification step S2, the position of the maximum out-of-plane deformation value in the lateral buckling waveform derived in the lateral buckling waveform derivation step S1 is identified. The maximum out-of-plane deformation value is determined by the absolute value of the deformation amount. Figure 6 is a graph showing an example of the analysis results of the lateral buckling waveform of an H-shaped steel beam. The horizontal axis of the graph is the position Lr from the end of the beam to the second joint / beam length L, and the vertical axis is the value obtained by dividing the absolute value of deformation in the y direction (width direction of the H-shaped steel beam) by the maximum deformation in the y direction (absolute value of deformation in the y direction / maximum deformation in the y direction). In the example shown in Figure 6, the positions of Lr / L = 0.25 and Lr / L = 0.75 for both the top flange and the bottom flange are the maximum out-of-plane deformation values ​​M in the lateral buckling waveform.

[0025] [Replacement process] In the replacement step S3, the first joint is replaced with the second joint at the position of the out-of-plane deformation maximum value M identified in the maximum value identification step S2. For example, if the positions of Lr / L=0.25 and Lr / L=0.75 are the out-of-plane deformation maximum value M, the first joint at these positions is replaced with the second joint. The position of the replaced first joint does not necessarily have to coincide with the out-of-plane deformation maximum value M, and may be off within a range of ±0.1L. If the length of the H-shaped steel beam is 7800 mm and the position of the out-of-plane deformation maximum value M is 1950 mm (7800 mm x 0.25) from the end, the first joint located 1980±780 mm from the end can be replaced with the second joint.

[0026] As in the example above, when there are multiple out-of-plane deformation maximum values ​​M, the first joint may be replaced with the second joint at the position of at least one of the multiple out-of-plane deformation maximum values ​​M.

[0027] In one embodiment of the present invention as described above, in the roof member connection structure 100 in which the deck plate 1 is connected to the H-shaped steel beam 2 by a plurality of joints N1 to N13 arranged in the longitudinal direction of the H-shaped steel beam 2, the position for arranging the second joint portion with high rigidity can be appropriately determined. This makes it possible to avoid positions where a stiffening effect cannot be expected, reduce construction costs, and efficiently improve the lateral buckling strength of the H-shaped steel beam 2.

[0028] In the above example, the lateral buckling waveform of the H-shaped steel beam was the secondary buckling mode, but the buckling mode is not limited to this. For example, if the lateral buckling waveform of the H-shaped steel beam is the tertiary buckling mode, up to three second joints can be provided.

[0029] In addition, in the above example, the lateral buckling waveform of the H-shaped steel beam is derived by eigenvalue analysis, but this is not limited to this, and the lateral buckling waveform of the H-shaped steel beam may also be derived, for example, by theoretical calculation.

[0030] The method for designing a joint structure for roof members of the present invention can also be applied to cases where multiple deck plates connected to each other are arranged in the longitudinal direction of an H-shaped steel beam. When multiple deck plates are arranged in the longitudinal direction of an H-shaped steel beam, in the replacement step S3, at least one first joint portion of the deck plate (hereinafter referred to as the first deck plate) corresponding to the position of the out-of-plane deformation maximum value M identified in the maximum value identification step S2 can be replaced with a second joint portion. For example, if the positions where Lr / L = 0.25 and Lr / L = 0.75 are the positions where the out-of-plane deformation maximum value M occurs, at least one first joint of the first deck plate corresponding to these positions is replaced with a second joint. As shown in Figure 7, if the roof component is made up of 10 deck plates 1, deck plates 1A1 and 1A2 corresponding to the positions where Lr / L = 0.25 and Lr / L = 0.75 are the first deck plates, and at least one joint of these first deck plates 1A1 and 1A2 is replaced with a second joint.

[0031] 8A to 8E are diagrams showing examples of the arrangement of second joints on the corresponding deck plate 1. In FIG. 8, "x" indicates the location where the second joint is to be provided. All "x"s have second joints. At least one of the "x"s may be the second joint, in which case the others may be the first joints. In the example shown in FIGS. 8A to 8E, the deck plate 1 comprises two protrusions 11, a central recess 12A located between the protrusions 11 and in the center of the H-shaped steel beam 2 in the longitudinal direction, and end recesses 12B located at both ends of the H-shaped steel beam 2 in the longitudinal direction. The central recess 12A may have an engaging portion 14 or a rib 14, in which case, a mating portion can be formed on one side and the other side of the engaging portion or rib 14. In FIG. 8, the locations other than the "x" may have first joints or may not have any joints.

[0032] The first example shown in Figure 8A is the most suitable example, in which second joints are placed in each of the recesses 12B at both ends and on one side of the central recess 12A among the recesses 12 of the corresponding deck plate 1. The first example is the most suitable when taking into consideration rigidity and construction costs, as it can efficiently improve rigidity by suppressing lifting of the entire deck plate (ends and center). The second example shown in Figure 8B is the next most preferable example after the first example, and has second joints located on one side of the recesses 12B at both ends and one side of the central recess 12A of the recesses 12 of the corresponding deck plate 1. In the second example, by joining the female side (the upper side of the engagement portion 14) at the end of the deck plate, it is possible to prevent the adjacent male side from floating.

[0033] The third example shown in Figure 8C is the next most suitable example after the second example, and has second joints located in each of the recesses 12B at both ends of the corresponding deck plate 1 and on one side and the other side of the central recess 12A. In other words, second joints are located in all possible locations. The third example has the highest rigidity because joints are located in all recesses 12. The fourth example shown in Figure 8D is the next most suitable example after the third example, in which second joint portions are placed only in the recesses 12B at both ends of the recesses 12 of the corresponding deck plate 1. In the fourth example, although lifting occurs in the center of the deck plate, because both ends are joined, lifting of one side of the deck plate does not occur, and lifting of the entire deck plate is suppressed. In the fifth example shown in Figure 8E, second joints are located on one side of the recesses 12B at both ends and on both sides of the central recess 12A of the recesses 12 of the corresponding deck plate 1. The fifth example is a specification to be selected when the widths of the recesses 12B are not uniform (for example, when one side is significantly narrower and there is not enough space to perform the joint).

[0034] The builder can select the arrangement of the second joint in the corresponding deck plate 1 depending on the required strength and cost.

[0035] Next, we will explain the analysis conducted to confirm the improvement in the lateral buckling strength of the beam due to the placement of the second joint. In the analysis of the elastic buckling load, an eigenvalue analysis of bending (bottom flange compression) was performed while changing the position of the second joint.

[0036] The rotational rigidity of the first joint is an experimental value of the joint formed by the above-mentioned burn-out plug welding. The rotational rigidity of the second joint is an experimental value obtained by joining an H-shaped steel beam and a deck plate using joints formed by a bearing plate 6 and two burn-off plug welds 7 as described in the second variant of this specification (Figure 14), which are provided on each deck plate, and then applying torsion to the H-shaped steel beam to confirm the rotational rigidity of the joint.

[0037] The positions of the second junctions that will be changed are shown in Table 1. The model names in Table 1 are expressed in the format "number of second junctions (position of second junctions)". For example, if there are two second junctions out of 13 junctions and the positions of the second junctions are N4 and N10, the model name will be "2(N4,N10)". Also, if no second junctions are provided (all first junctions), the model name will be "0", and if one second junction is provided, the model name will be "1(N1) to 1(N13)".

[0038] [Table 1]

[0039] [Analysis results when one second joint is installed] Figure 9 is a graph that overlays the results of the analysis of the lateral buckling waveform of an H-shaped steel beam (all joints are first joints) also shown in Figure 8 with the results of the elastic buckling load when one joint is designated as the second joint. In the graph, the horizontal axis is the position Lr of the second joint from the end of the beam / beam length L, and the vertical axis is the eigenvalue: elastic buckling load eMcr (kNm) and the value obtained by dividing the absolute value of deformation in the y direction by the maximum deformation in the y direction (absolute value of deformation in the y direction / maximum deformation in the y direction).

[0040] As shown in Fig. 9, it was found that the elastic buckling load could be improved by increasing the rotational rigidity of the area where the deformation amount increased when all the joints were the first joints (by replacing them with the second joints). For example, in models (1(N4), (1(N10))) in which the second joint was positioned near the maximum out-of-plane deformation (near Lr / L = 0.25 or Lr / L = 0.75), a tendency for the elastic buckling load to improve was observed (elastic buckling load ≈ 215 kNm). On the other hand, in the model (1(N7)) in which the second joint was located at the center of the beam (Lr / L=0.5, N7) and the models (1(N1), 1(N13)) in which the second joint was located near the end of the beam, the elastic buckling load did not improve compared to the model (0) in which all joints were the first joints.

[0041] [When two second joints are provided] Figure 10 is a graph of the analysis results that explains the effect of providing two second joints. As shown in Figure 10, the increase in yield strength was large in models (2(N4,N10), 2(N3,N11), and 2(N5,N9)) in which the second joints were located near Lr / L = 0.25 and Lr / L = 0.75, where the out-of-plane deformation maximum value is greatest. For example, the increase in yield strength in model (2(N4,N10)) in which the second joints were located at N4 and N10 was more than twice that of model (1(N4), 1(N10)) in which the second joints were located at N4 or N10.

[0042] [Second Joint Embodiment] Next, a second embodiment of the joining portion will be described. Figure 11 is an enlarged perspective view of the second joint in the joint structure of the roof members, and Figures 12A to 12C are cross-sectional views taken along lines AA, BB, and CC in Figure 11, respectively. As shown in Figure 11 and Figures 12A to 12C, the second joint can be formed in the recess 12 of the deck plate 1 by two burnt-out plug welds 7 spaced apart in the extension direction of the recess 12 (y direction, width direction of the H-shaped steel beam 2). Since the deck plate 1 is a thin plate, there is no need to pre-drill holes in the deck plate 1, and no stud bolts or plates are required, so it can be formed at low cost.

[0043] In the above embodiment, the first joint is formed by one quench plug weld per recess, and the second joint is formed by two quench plug welds per recess, but this is not limitative as long as the second joint has higher rigidity and strength than the first joint. For example, the first joint may be formed by one rivet per recess, and the second joint may be formed by two rivets per recess.

[0044] In the following, a modification of the second bonding portion embodiment described above will be described. In the first modified example shown in Figure 13, the second joint, which is more rigid than the first joint, has a deck plate 1 placed on an H-shaped steel beam 2 and is composed of a stud bolt 3, a nut 4, a washer 5, and a bearing plate 6.

[0045] One end of the stud bolt 3 is welded to the flange 21A of the H-shaped steel beam 2, and extends through the recess 12 in the deck plate 1. Specifically, for example, with the deck plate 1 placed on the H-shaped steel beam 2, the stud bolt 3 is welded from above the deck plate 1 using any of various stud welding methods. As already mentioned, the deck plate 1 is a thin plate, so by welding the stud bolt 3 from above the deck plate 1, the deck plate 1 is melted and holes are drilled while the stud bolt 3 is welded to the H-shaped steel beam 2. Therefore, in this modified example, there is no need to pre-drill holes in the deck plate 1 at the joint.

[0046] Nut 4 is screwed onto stud bolt 3 from the end opposite H-shaped steel beam 2, and washer 5 is inserted between nut 4 and deck plate 1. By inserting washer 5 onto stud bolt 3 and then screwing nut 4 onto it, and tightening nut 4 while in contact with washer 5, tension is introduced into stud bolt 3, and a frictional joint can be formed between deck plate 1 and H-shaped steel beam 2.

[0047] In addition to a washer 5, a bearing plate 6 is interposed between the nut 4 and the deck plate 1. The bearing plate 6 extends perpendicular to the direction of the corrugations of the deck plate 1, that is, parallel to the convex portions 11 and concave portions 12. The width of the bearing plate 6 corresponds to the width of the concave portions 12, for example.

[0048] In a second modified example shown in Figure 14, the second joint is composed of a support plate 6 and a weld 7. A vertical through hole 61 is formed in the support plate 6, and the weld 7 is formed by filling the interior of the through hole 61 with weld metal, for example by burn-out plug welding. The weld 7 passes through the recess 12 in the deck plate 1 and contacts the inner wall surface of the through hole 61 and the flange 21A of the H-shaped steel beam 2. The weld 7 joins the inner wall surface of the through hole 61, the recess 12 in the deck plate 1, and the upper surface of the flange 21A.

[0049] Because the deck plate 1 is a thin plate, it is possible to form the welded portion 7 by, for example, drilling a hole that connects the inside of the through hole 61 to the surface of the flange 21A while melting the deck plate 1 using burn-out plug welding. Therefore, in this embodiment, there is no need to pre-drill holes in the deck plate 1 at the joint.

[0050] 15, multiple support plates 6A, 6B are arranged in the extension direction (y direction) of the recess 12. In the illustrated example, a vertical through hole 61A is formed in the support plate 6A, and a vertical through hole 61B is also formed in the support plate 6B. Furthermore, a weld 7A is formed through the recess 12 of the deck plate 1 and contacts the inner wall surface of the through hole 61A and the flange 21A of the H-shaped steel beam 2, and a weld 7B is formed similarly in contact with the inner wall surface of the through hole 61B and the flange 21A. Even when multiple support plates 6A, 6B are arranged separately in this way and welds 7A, 7B are formed between each support plate and the support member, local deformation around the welds is prevented, and stable rigidity can be exerted against rotational deformation of the support member.

[0051] In addition, the deck plate 1 and the H-shaped steel beam 2 do not need to be directly joined, and height-adjusting raising materials (channel steel, lip channel steel, etc.) or tight frames may be installed between the deck plate 1 and the H-shaped steel beam 2.

[0052] Furthermore, the roof member is not limited to the corrugated deck plate 1, and it is also possible to use, for example, a flat deck with a flat upper surface and ribs on the lower surface. As shown in Figure 16, the flat deck 30 is connected to the H-shaped steel beam 2 using a tight frame 9. Specifically, the lower surface of the plate-shaped portion 31 of the flat deck 30, which is made up of a plate-shaped portion 31 and a rib portion 32, is joined to the upper surfaces of the convex portions 91A, 91B of the tight frame 9, and the upper surface of the flange 21A of the H-shaped steel beam 2 is joined to the lower surface of the concave portion 92 of the tight frame 9. In this embodiment, the rigidity of a portion can be increased by making the plate thickness of a portion of the protrusions 91A thicker than that of the other protrusions 91B. Alternatively, the rigidity may be increased by widening the plate width of a portion of the tight frame 9.

[0053] Although the present invention relates to a joint structure between a support member and a roof member, it can also be applied without any problems to a joint structure between a support member such as an H-shaped steel beam and a floor member.

[0054] Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modifications or alterations within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention. [Explanation of symbols]

[0055] 1...deck plate, 1A...first deck plate, 11...convex portion, 12...concave portion, 2...H-shaped steel beam, 21A, 21B...flange, 22...web, 3...stud bolt, 4...nut, 5...washer, 6...bearing plate, 61...through hole, 7...weld, 9...tight frame, 91...convex portion, 92...concave portion, 100...joint structure, N1 to N13...joint, S1...lateral buckling waveform derivation process, S2...maximum value identification process, S3...replacement process.

Claims

1. A method for designing a joint structure between an H-shaped steel beam, which is a supporting member, and a roof member, comprising: The roof member is joined to the H-shaped steel beam by a first joint portion arranged in the longitudinal direction of the H-shaped steel beam and a second joint portion having higher rigidity than the first joint portion, A step of analytically deriving a lateral buckling waveform of the H-shaped steel beam when it is assumed that the roof member is joined to the H-shaped steel beam only by the first joint; Identifying the location of the out-of-plane deformation maximum in the lateral buckling waveform; and replacing the first joint with the second joint at the position of the maximum out-of-plane deformation.

2. A method for designing a joint structure between an H-shaped steel beam, which is a supporting member, and a roof member, comprising: The roof member is joined to the H-shaped steel beam by a first joint portion arranged in the longitudinal direction of the H-shaped steel beam and a second joint portion having higher rigidity than the first joint portion, The roof member is configured by arranging one or more deck plates having a concave-convex shape such that the extension direction of the concave-convex shape is perpendicular to the longitudinal direction of the H-shaped steel beam, A step of analytically deriving a lateral buckling waveform of the H-shaped steel beam when it is assumed that the roof member is joined to the H-shaped steel beam only by the first joint; Identifying the location of the out-of-plane deformation maximum in the lateral buckling waveform; and replacing at least one first joint of a first deck plate corresponding to the position of the out-of-plane deformation maximum with the second joint.

3. 3. The method for designing a joint structure of a roof member according to claim 2, wherein the first joint and the second joint are refractory plug welds provided in recesses of the first deck plate, and the rigidity of the second joint is increased by increasing the number of refractory plug welds.

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