Joint structure between box section column and H-shaped steel beam and manufacturing method for joint structure

Abstract

To provide a bonding structure of a box column and an H-shaped steel beam and a manufacturing method of the bonding structure having high manufacturing efficiency and capable of reliably securing assembly accuracy of members.SOLUTION: Provided is a bonding structure of a box column and an H-shaped steel beam in which the H-shaped steel beam is bonded to the welding assembled box column configured by bonding four skin plates to each other by corner welding, via an outer diaphragm. A hole for welding surrounded by a patch is provided in between surfaces of the skin plates and an end surface of the outer diaphragm. The box column and the outer diaphragm are bonded to each other by a welding part formed by filling a molten metal into the hole for welding by electroslag welding.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a joint structure between a column and a beam in a building and a manufacturing method for the joint structure, and more particularly to a joint structure between a box section column and an H-shaped steel beam and a manufacturing method for the joint structure. [Background technology]

[0002] In super high-rise steel buildings, welded assembled box columns consisting of four skin plates joined together by corner welding are often used. At the joint between the box column and H-shaped steel beam, when horizontal forces act on the building during an earthquake or other events, stress is transmitted from the flange of the H-shaped steel beam to the skin plate of the box column. To prevent local deformation of the skin plate of the box column due to this stress, it is common to install a horizontal stiffener called a diaphragm at the same height as the flange of the H-shaped steel beam on the box column.

[0003] The joints between box-section columns and H-shaped steel beams can be broadly classified into three types: the internal diaphragm type, which uses an internal diaphragm; the through diaphragm type, which uses a through diaphragm; and the external diaphragm type, which uses an external diaphragm.

[0004] Among these, the internal diaphragm type is most commonly used for the joint between a box column and an H-shaped steel beam. Figures 6(a) and 6(b) show a perspective view and a plan view of a joint between a box column 81 and an H-shaped steel beam 82 using the internal diaphragm type. Figures 7 and 8 show longitudinal sectional views of the main parts of the joint between a box column 81 and an H-shaped steel beam 82 using the internal diaphragm type. As shown in Figures 7 and 8, the skin plate 811 of the box column 81 and the internal diaphragm 84 are generally joined by electroslag welding.

[0005] Specifically, in the process of assembling a skin plate 811 to manufacture a box-shaped cross-section column 81, an inner diaphragm 84 is installed inside the box-shaped cross-section column 81. Then, as shown in FIG. 7, both sides of the gap between the back surface of the skin plate 811 and the end surface of the inner diaphragm 84 are surrounded by a backing metal 841 to provide a welding hole 842 having a rectangular cross-section. Furthermore, a molten slag bath is formed in the welding hole 842, and the molten slag is heated by resistance heating by feeding a welding wire into the molten slag bath while supplying an electric current from the welding wire. In this way, while applying a large heat input of up to several million J / cm, as shown in FIG. 8, the base material around the welding hole 842 is melted and the welding hole 842 is filled with molten metal. Electroslag welding is extremely efficient compared to manual or semi-automatic gas-shielded arc welding.

[0006] However, since the inner diaphragm 84 and the backing plate 841 need to be joined to the inside of the box-shaped cross-section column 81, it is difficult to ensure assembly precision for the root spacing 84G between the skin plate 811 of the box-shaped cross-section column 81 and the inner diaphragm 84, and the backing plate 841, etc.

[0007] 9(a) and 9(b) show a perspective view and a plan view of a through diaphragm type joint between a box section column 81 and an H-shaped steel beam 82. As shown in Fig. 9(a) and 9(b), in the through diaphragm type joint between a box section column 81 and an H-shaped steel beam 82, a through diaphragm 85 is provided so as to penetrate the cross section of the box section column 81. The through diaphragm type joint between a box section column and an H-shaped steel beam is assembled by cutting the box section column 81 at a position where the through diaphragm 85 is to be provided, inserting the through diaphragm 85 into the cut position, and welding the box section column 81 and the through diaphragm 85 together.

[0008] Here, the weld 86 between the box section column 81 and the through diaphragm 85 is a full penetration weld, thereby ensuring the performance of the box section column 81 even if the through diaphragm 85 is provided so as to penetrate the cross section of the box section column 81.

[0009] However, as described above, the assembly of the joint between the box column and the H-shaped steel beam using the through diaphragm type is performed by cutting the box column 81 at the position where the through diaphragm 85 is to be provided, inserting the through diaphragm 85 at the cut position, and welding the box column 81 and the through diaphragm 85. Therefore, it takes time and effort to cut the box column 81 and to prepare the groove for full penetration welding of the box column 81 to the through diaphragm 85, and the amount of welding tends to be large. In addition, high skill is required to ensure accuracy in aligning the box column 81 to be joined above and below the through diaphragm 85.

[0010] Furthermore, the through diaphragm 85 provided so as to penetrate the cross section of the box column 81 constitutes a part of the box column 81 when the building is designed. As a prerequisite for this design, it is necessary to use a welding material having a strength equal to or greater than that of the box column 81 for the welded portion 86 between the box column 81 and the through diaphragm 85, which tends to increase the material cost and construction load. The box column 81, which is often used in high-rise buildings, is often made of high-strength steel, and it is necessary to use a high-strength welding material having a strength class equal to or greater than that of the box column 81 for the welded portion 86 between the box column 81 and the through diaphragm 85.

[0011] 10(a) and 10(b) show a perspective view and a plan view of a joint between a box column and an H-shaped steel beam using an external diaphragm. As shown in FIG. 10(a) and FIG. 10(b), in the joint between a box column and an H-shaped steel beam using an external diaphragm, the box column 81 and the external diaphragm 83 are welded from the outside of the box column 81. This makes it easy to attach the external diaphragm 83 to the box column 81, and ensures the assembly accuracy of the components. Furthermore, since no diaphragm is inserted inside the box column 81, the construction is excellent when filling the inside of the box column 81 with concrete.

[0012] 11 to 13 show longitudinal cross-sectional views of the main parts of a joint between a box column 81 and an H-shaped steel beam 82 using an external diaphragm. Fig. 11 shows an example in which a weld 87 between the box column 81 and the external diaphragm 83 is fillet welded. Fig. 12 shows an example in which a weld 88 between the box column 81 and the external diaphragm 83 is fully welded. Fig. 13 shows an example in which a weld 89 between the box column 81 and the external diaphragm 83 is partially welded.

[0013] The box-shaped column 81 and the outer diaphragm 83 are generally joined by fillet welding as shown in FIG. 11, or by full penetration welding or partial penetration welding after groove preparation on the outer diaphragm 83 as shown in FIG. 12 and FIG. 13. Semi-automatic gas-shielded arc welding is used for these fillet welding, full penetration welding and partial penetration welding. However, when a large-section H-shaped steel beam 2 is used, the stress acting on the skin plate 811 of the box-shaped column 81 from the flange 821 of the H-shaped steel beam 82 during an earthquake or the like becomes large, and the thickness of the outer diaphragm 83 must be increased in order to prevent local deformation of the skin plate 811 of the box-shaped column 81. The larger the thickness of the outer diaphragm 83, the more passes are required for gas-shielded arc welding, which tends to result in lower manufacturing efficiency compared to electroslag welding used in the inner diaphragm type.

[0014] Furthermore, as shown in Fig. 10(b), in a joint between a box section column 81 and an H-shaped steel beam 82 using an external diaphragm, the protruding width 83h of the external diaphragm 83 from the skin plate 811 of the box section column 81 is often made large in order to ensure the strength of the column-beam joint. Therefore, when the box section column 81 with the external diaphragm 83 attached is manufactured in a steel frame manufacturing factory and transported to the construction site, if the protruding width 83h of the external diaphragm 83 is large, the number of box section columns 81 that can be loaded onto a transport vehicle at one time is limited, which tends to deteriorate the transport efficiency.

[0015] Therefore, Patent Documents 1 and 2 propose an external diaphragm that can ensure the strength of the column-beam joint while reducing the protruding width of the external diaphragm, and a column-beam joint structure using the same.

[0016] Specifically, Patent Document 1 proposes using a sleeve-shaped external diaphragm formed by bending flat steel outward to fit the outer peripheral surface of a square steel pipe column, thereby reducing the planar shape compared to conventional external diaphragms.

[0017] In addition, Patent Document 2 proposes combining four L-shaped steel pieces to form an outer diaphragm, and using a material with a large plate thickness for the L-shaped steel pieces to reduce the dimensions of the outer diaphragm. The L-shaped steel pieces are joined together by fillet welding or partial penetration welding on the front and back surfaces. [Prior art documents] [Patent documents]

[0018] [Patent Document 1] JP 2006-002351 A [Patent Document 2] JP 2016-108868 A Summary of the Invention [Problem to be solved by the invention]

[0019] Here, in order to ensure the quality of the welded joint between the box section column or square steel pipe column and the external diaphragm, it is necessary to ensure the root spacing between the square steel pipe column and the external diaphragm with appropriate accuracy. If the root spacing is too small, welding defects are likely to occur, and if the root spacing is too large, the amount of welding increases and workability deteriorates. However, in Patent Document 1, there is a problem that it is difficult to ensure the dimensional accuracy when manufacturing the external diaphragm and the assembly accuracy when attaching the external diaphragm to the box section column or square steel pipe column, because localized residual stress occurs in the flat steel when bending the flat steel out of the plane.

[0020] In addition, in Patent Document 1 and Patent Document 2, it is assumed that the box section column or square steel pipe column and the outer diaphragm are joined by fillet welding using gas shielded arc welding, or by partial penetration welding after groove preparation on the outer diaphragm. Therefore, there is a problem that the manufacturing efficiency is low compared to electroslag welding adopted for the inner diaphragm type.

[0021] The present invention has been made to solve such problems, and aims to provide a joint structure between a box section column and an H-shaped steel beam, and a manufacturing method for such a joint structure, which has excellent manufacturing efficiency and can reliably ensure the assembly precision between the components. [Means for solving the problem]

[0022] In order to solve the above problems, the present invention has the following features.

[0023] [1] A connection structure between a box column and an H-shaped steel beam, in which an H-shaped steel beam is connected to a welded assembled box column consisting of four skin plates joined together by corner welding, via an external diaphragm, in which a welding hole surrounded by a metal is provided between the surface of the skin plate and the end face of the external diaphragm, and the box column and the external diaphragm are joined by a weld formed by filling the welding hole with molten metal by electroslag welding.

[0024] [2] A joint structure between a box section column and an H-shaped steel beam described in [1], in which a partition made of a steel piece is provided inside the welding hole so that the welding hole is divided into two or more holes in the thickness direction of the outer diaphragm.

[0025] [3] A joint structure between a box section column and an H-shaped steel beam described in [1] or [2], wherein the yield strength of the external diaphragm is greater than the yield strength of the flange of the H-shaped steel beam.

[0026] [4] A manufacturing method for a joint structure between a box column and an H-shaped steel beam, in which an H-shaped steel beam is joined via an external diaphragm to a welded assembled box column consisting of four skin plates joined together by corner welding, in which a welding hole is provided by surrounding the area between the surface of the skin plate and the end face of the external diaphragm with a backing metal, and the box column and the external diaphragm are joined by filling the welding hole with molten metal by electroslag welding with a heat input of 100 to 1500 kJ / cm to form a weld.

[0027] [5] A manufacturing method for a joint structure between a box section column and an H-shaped steel beam described in [4], in which a partition made of a steel piece is provided inside the welding hole so that the welding hole is divided into two or more holes in the thickness direction of the outer diaphragm.

[0028] [6] A manufacturing method for a joint structure between a box section column and an H-shaped steel beam described in [4] or [5], wherein the yield strength of the external diaphragm is greater than the yield strength of the flange of the H-shaped steel beam. Effect of the Invention

[0029] In the joint structure between a box column and an H-shaped steel beam and the manufacturing method thereof according to the present invention, the box column and the external diaphragm are joined by electroslag welding, which can significantly improve the manufacturing efficiency compared to the joint structure between a box column and an H-shaped steel beam using a general external diaphragm type joined by gas shielded arc welding.

[0030] In addition, in the joint structure between a box column and an H-shaped steel beam and the manufacturing method thereof according to the present invention, the electroslag welding between the box column and the outer diaphragm is performed from the outside of the box column, so that the assembly precision of the root clearance between the surface of the skin plate of the box column and the end face of the outer diaphragm, the backing metal, etc. can be reliably ensured. [Brief description of the drawings]

[0031] [Figure 1]FIG. 1 is a vertical cross-sectional view showing a main part of a joint structure between a box section column and an H-shaped steel beam according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view showing a main part of a joint structure between a box section column and an H-shaped steel beam according to the first embodiment of the present invention. [Diagram 3] 3(a) to 3(f) are plan views showing examples of the shapes of the exterior diaphragms in the joint structure of the present invention between a box section column and an H-shaped steel beam. [Figure 4] FIG. 4 is a vertical sectional view showing a main part of a joint structure between a box section column and an H-shaped steel beam according to a second embodiment of the present invention. [Diagram 5] FIG. 5 is a vertical sectional view showing a main part of a joint structure between a box section column and an H-shaped steel beam according to a second embodiment of the present invention. [Figure 6] 6(a) and 6(b) are a perspective view and a plan view showing a joint between a box section column and an H-shaped steel beam using an internal diaphragm. [Figure 7] FIG. 7 is a vertical cross-sectional view showing a main part of a joint between a box section column and an H-shaped steel beam using an internal diaphragm. [Figure 8] FIG. 8 is a vertical cross-sectional view showing a main part of a joint between a box section column and an H-shaped steel beam using an internal diaphragm. [Figure 9] 9(a) and 9(b) are a perspective view and a plan view showing a through diaphragm type joint between a box section column and an H-shaped steel beam. [Figure 10] 10(a) and 10(b) are a perspective view and a plan view showing a joint between a box section column and an H-shaped steel beam using an external diaphragm type joint. [Figure 11] FIG. 11 is a vertical cross-sectional view showing a main part of a joint between a box section column and an H-shaped steel beam using an external diaphragm type. [Figure 12] FIG. 12 is a vertical cross-sectional view showing a main part of a joint between a box section column and an H-shaped steel beam using an external diaphragm type. [Figure 13] FIG. 13 is a vertical cross-sectional view showing a main part of a joint between a box section column and an H-shaped steel beam using an external diaphragm type. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Hereinafter, with reference to the drawings, an embodiment of a joint structure between a box section column and an H-shaped steel beam and a manufacturing method of the joint structure of the present invention will be described in detail. First Embodiment 1 and 2 show vertical cross-sectional views of essential parts of a joint structure between a box section column and an H-shaped steel beam according to a first embodiment of the present invention.

[0033] As shown in Fig. 1 and Fig. 2, the joint structure between a box column and an H-shaped steel beam in this embodiment is such that an H-shaped steel beam 2 is joined to a welded assembled box column 1 formed by four skin plates 11 joined to each other by corner welding (not shown) via an outer diaphragm 3. Specifically, as shown in Fig. 1, a welding hole 32 surrounded by a backing metal 31 is provided between the surface of the skin plate 11 of the box column 1 and the end face of the outer diaphragm 3. Then, as shown in Fig. 2, the box column 1 and the outer diaphragm 3 are joined to each other by a weld 5 formed by filling the welding hole 32 with molten metal by electroslag welding.

[0034] As shown in FIG. 1, the cross-sectional shape of the electroslag welding hole 4 is rectangular, similar to the electroslag welding hole between the skin plate and the inner diaphragm at the joint between the box section column and the H-shaped steel beam by the inner diaphragm type.

[0035] For the H-shaped steel beam 2 connected to the box section column 1, either roll-formed H-shaped steel or welded H-shaped steel can be used.

[0036] In addition, the backing plate 31 may be made of the same steel material as that used in electroslag welding between the skin plate and the inner diaphragm at the joint between the box section column and the H-shaped steel beam by the inner diaphragm type.

[0037] In addition, it is preferable that the yield strength of the outer diaphragm 3 is greater than the yield strength of the flange of the H-shaped steel beam 2 attached to the outer diaphragm 3. In this way, the protruding width h of the outer diaphragm 3 shown in FIG. 1 can be increased without reducing the strength of the beam-column joint against the stress acting from the flange 21 of the H-shaped steel beam 2 to the skin plate 11 of the box section column 1 during an earthquake or the like. d When the box-section column 1 with the outer diaphragm 3 attached is manufactured in a steel frame manufacturing factory and transported to a construction site, the protruding width h of the outer diaphragm 3 can be reduced. d This makes it difficult for the transportation efficiency of the box section column 1 to be impaired.

[0038] In the joint structure between a box column and an H-shaped steel beam of this embodiment, the box column 1 and the outer diaphragm 3 are joined by electroslag welding. Therefore, compared with the joint structure between a box column and an H-shaped steel beam using a general outer diaphragm type joined by gas shielded arc welding, the manufacturing efficiency can be significantly improved.

[0039] Furthermore, in the joint structure between a box column and an H-shaped steel beam according to the present invention, since the outer diaphragm 3 is attached to the outside of the box column 1, electroslag welding between the box column 1 and the outer diaphragm 3 is performed from the outside of the box column 1. This makes it possible to reliably ensure assembly precision for the root clearance G between the surface of the skin plate 11 of the box column 1 and the end face of the outer diaphragm 3, the backing plate 31, etc.

[0040] In addition, the root spacing G between the surface of the skin plate 11 of the box section column 1 and the end face of the external diaphragm 3 in the joint structure of a box section column and an H-shaped steel beam in this embodiment can be set to an appropriate dimension, similar to the root spacing between the inner surface of the box section column and the end face of the internal diaphragm at the joint between a box section column and an H-shaped steel beam using the internal diaphragm type.

[0041] Figures 3(a) to 3(f) show various examples of the shape of the exterior diaphragm 3 (3A to 3C) in the joint structure of a box column and an H-shaped steel beam of this embodiment. As shown in Figures 3(a) to 3(f), the exterior diaphragm 3 is joined to one to four of the four side faces of the box column 1 depending on the number of H-shaped steel beams 2 attached to the box column 1.

[0042] 3(a) and 3(b) are examples in which a polygonal steel plate is used as the outer diaphragm 3A. Also, FIG. 3(c) and FIG. 3(d) are examples in which a rectangular steel plate is used as the outer diaphragm 3B. Furthermore, FIG. 3(e) and FIG. 3(f) are examples in which a part of the planar shape of the outer diaphragm 3C has a circular arc. As shown in FIG. 3(e) and FIG. 3(f), when a part of the planar shape of the outer diaphragm 3C has a circular arc, stress can be smoothly transmitted from the flange 21 of the H-shaped steel beam 2 to the skin plate 11 of the box section column 1 via the outer diaphragm. Therefore, it is preferable because it is possible to suppress the occurrence of cracks and breaks in the outer diaphragm 3.

[0043] In addition, the manufacturing method of the joint structure between a box section column and an H-shaped steel beam in this embodiment is realized by performing electroslag welding so that the heat input is 100 to 1500 kJ / cm when manufacturing the joint structure between the box section column 1 and the H-shaped steel beam 2 described above. Second Embodiment 4 and 5 show longitudinal sectional views of essential parts of a joint structure between a box section column and an H-shaped steel beam according to a second embodiment of the present invention.

[0044] As shown in Figs. 4 and 5, in the joint structure of the box-shaped column and the H-shaped steel beam of this embodiment, the flange 21 of the H-shaped steel beam 2 and the outer diaphragm 3 have a larger plate thickness than the joint structure of the box-shaped column and the H-shaped steel beam of the first embodiment. When electroslag welding with a large heat input is applied to general steel materials for architectural structures, the toughness of the welded portion 5 by electroslag welding is reduced, and brittle fracture is likely to occur in the welded portion 5 due to the stress transmitted from the flange 21 of the H-shaped steel beam 2 to the outer diaphragm 3 during an earthquake. In particular, when the plate thickness of the outer diaphragm 3 is large as in this embodiment, the amount of heat input required to ensure penetration of the weld metal into the members around the welding hole during electroslag welding increases, which is likely to cause a significant decrease in the toughness of the welded portion 5.

[0045] Therefore, in the joint structure of the box-shaped column and the H-shaped steel beam of this embodiment, as shown in Figs. 4 and 5, a partition wall 33 made of a steel piece is provided inside a welding hole surrounded by the surface of the skin plate 11 of the box-shaped column 1, the end face of the external diaphragm 3, and the backing metal 31. As a result, the welding hole surrounded by the surface of the skin plate 11 of the box-shaped column 1, the end face of the external diaphragm 3, and the backing metal 31 is divided into two welding holes 34, 35 in the thickness direction of the external diaphragm 3. In this way, the widths w1, w2 of the welding holes 34, 35 in the thickness direction of the external diaphragm 3 can be reduced. That is, even if the thicknesses of the flange 21 of the H-shaped steel beam 2 and the external diaphragm 3 are large, the amount of heat input required to ensure penetration of the weld metal into the members around the welding hole during electroslag welding can be reduced, and a significant decrease in the toughness of the welded portion 5 can be suppressed.

[0046] The above describes embodiments of the joint structure between a box section column and an H-shaped steel beam and the manufacturing method of the joint structure of the present invention. However, the specific configuration of the present invention is not limited to the above-mentioned embodiments, and design changes are possible without departing from the gist of the present invention.

[0047] For example, although the widths w1 and w2 of the welding holes 34 and 35 are the same in Fig. 4 and Fig. 5, the widths w1 and w2 of the welding holes 34 and 35 may be different. Also, although Fig. 4 and Fig. 5 show an example in which the welding hole surrounded by the surface of the skin plate 11 of the box section column 1, the end face of the outer diaphragm 3, and the backing metal 31 is divided into two welding holes 34 and 35, the welding hole may be divided into three or more welding holes in the thickness direction of the outer diaphragm 3. It is preferable to appropriately set the number of divisions and width of the welding hole in consideration of the type and dimensions of the steel material used, the welding conditions of the electroslag welding, etc., so that brittle fracture of the welded part 5 can be effectively suppressed against the stress transmitted from the flange 21 of the H-shaped steel beam 2 to the outer diaphragm 3 during an earthquake or the like. EXAMPLES

[0048] In the joint structure of the second embodiment between a box section column and an H-shaped steel beam, a partition wall 33 was provided inside the welding hole to divide the outer diaphragm 3 into two welding holes 34, 35 in the thickness direction, thereby verifying how much the heat input of electroslag welding could be reduced.

[0049] First, calculation examples No. 1 to No. 5 were set based on the joint structure of the box section column and the H-shaped steel beam of the first embodiment shown in Fig. 1 and Fig. 2. Table 1 shows the outer diameter D c and the thickness t of skin plate 11 c , the protruding width h of the outer diaphragm 3 d and plate thickness t d , the root spacing G and width w0 of the weld hole 32 are shown.

[0050] [Table 1]

[0051] As shown in Table 1, in calculation examples 1 to 5, the outer diameter D c The outer diameter D of the box section column 1 was changed to five types: 500 mm, 800 mm, 1000 mm, 1200 mm, and 1500 mm.c In calculation examples 1 to 5, the thickness t of the skin plate of the box section column 1 is c , and the protruding width h of the outer diaphragm 3 d and plate thickness t d The root spacing G of the welding holes 32 was set to 23 mm in all of the calculation examples Nos. 1 to 5.

[0052] The amount of heat input required to ensure penetration of the weld metal into the members surrounding the weld hole 32 during electroslag welding varies depending on the dimensions of the members surrounding the weld hole 32. Therefore, in this embodiment, as a calculation standard, the amount of heat input in calculation example No. 1 was assumed to be 300 kJ / cm. The calculation of the amount of heat input in calculation examples No. 2 to 5 was performed using the cross-sectional area of ​​the weld hole 32 in calculation examples No. 2 to 5 relative to calculation example No. 1, the plate thickness t of the skin plate 11 of the box section column 1, c , the protruding width h of the outer diaphragm 3 d and plate thickness t d The calculation results are shown in Table 1.

[0053] As can be seen from calculation examples No. 1 to 5 in Table 1, the thickness t d When the thickness t of the outer diaphragm 3 is small, the heat input of the electroslag welding is kept small, and the toughness of the welded portion 5 is not significantly deteriorated. d As this increases, the heat input in electroslag welding also increases, which tends to cause a significant decrease in the toughness of the welded portion 5.

[0054] Next, calculation examples No. 3A to No. 5A were set based on the joint structure of the box column and the H-shaped steel beam of the second embodiment shown in Figures 4 and 5, and the heat input of the electroslag welding was calculated. Table 2 shows the heat input of the box column 1 in the calculation examples No. 3A to No. 5A. c and the thickness of the skin plate, t c , the protruding width h of the outer diaphragm 3 d and plate thickness t d, and the root spacing G and widths w1 and w2 of the welding holes 34 and 35 are shown. Calculation examples No. 3A to 5A are examples in which a partition wall 33 is provided inside the welding hole 32 of calculation examples No. 3 to 5 shown in Table 1, and the welding hole 32 is divided into two welding holes 34 and 35 in the thickness direction of the outer diaphragm 3. The thickness B of the partition wall 33 in calculation example No. 3A is 15 mm, and the widths w1 and w2 of the welding holes 34 and 35 are 22.5 mm, respectively. The thickness B of the partition wall 33 in calculation example No. 4A is 15 mm, and the widths w1 and w2 of the welding holes 34 and 35 are 32.5 mm, respectively. The thickness B of the partition wall 33 in calculation example No. 5A is 20 mm, and the widths w1 and w2 of the welding holes 34 and 35 are 40 mm, respectively.

[0055] [Table 2]

[0056] Then, the heat input due to electroslag welding was calculated for calculation examples No. 3A to No. 5A in the same manner as calculation examples No. 1 to No. 5. The calculation results are also shown in Table 2.

[0057] As can be seen from calculation examples Nos. 3A to 5A in Table 2, by dividing the welding hole for electroslag welding into two welding holes 34, 35 by partition 33 and performing electroslag welding on each of welding holes 34, 35, the heat input is reduced to the same level as calculation examples Nos. 1 and 2 in Table 1. In other words, it was confirmed that by dividing the welding hole for electroslag welding into two welding holes 34, 35 by partition 33 and performing electroslag welding on each of welding holes 34, 35, a significant decrease in toughness of welded portion 5 can be suppressed. [Explanation of symbols]

[0058] 1 Box-shaped column 11 Skin Plate 2 H-shaped steel beam 21 Flange 22 Web 3, 3A~3C Outer diaphragm 31 Backing 32, 34, 35 Welding holes 33 Bulkhead W0~W2 Welding hole width 5 Welding D c Outside diameter of box section column t c Skin plate thickness t d Outer diaphragm thickness h d Outer diaphragm protrusion width G Root Spacing B Thickness of bulkhead 81 Box-shaped column 811 Skin Plate 82 H-shaped steel beam 821 Flange 83 Outer diaphragm 83h Outer diaphragm protrusion width 84 Inner diaphragm 84G Route Spacing 841 Backing 842 Welding holes 85 through diaphragm 86~89 Welded parts

Claims

1. A joint structure between a box-shaped column and an H-shaped steel beam, in which an H-shaped steel beam is joined to a welded assembled box-shaped column formed by joining four skin plates to each other by corner welding via an external diaphragm, A joining structure between a box section column and an H-shaped steel beam, in which a welding hole surrounded by a metal is provided between the surface of the skin plate and the end face of the outer diaphragm, and the box section column and the outer diaphragm are joined by a weld formed by filling the welding hole with molten metal by electroslag welding.

2. The joint structure of a box section column and an H-shaped steel beam as described in claim 1, wherein a partition made of a steel piece is provided inside the welding hole so that the welding hole is divided into two or more holes in the plate thickness direction of the outer diaphragm.

3. 3. The joint structure of a box section column and an H-shaped steel beam according to claim 1 or 2, wherein the yield strength of the outer diaphragm is greater than the yield strength of the flange of the H-shaped steel beam.

4. A manufacturing method for a joint structure between a box column and an H-shaped steel beam, the method comprising: joining an H-shaped steel beam to a welded assembled box column formed by joining four skin plates to each other by corner welding via an external diaphragm, A manufacturing method for a joining structure of a box section column and an H-shaped steel beam, comprising: providing a welding hole by surrounding the area between the surface of the skin plate and the end face of the outer diaphragm with a metal strip; filling the welding hole with molten metal by electroslag welding with a heat input of 100 to 1500 kJ / cm to form a weld, thereby joining the box section column and the outer diaphragm.

5. The manufacturing method of the joint structure of a box section column and an H-shaped steel beam as described in claim 4, wherein a partition wall made of a steel piece is provided inside the welding hole so that the welding hole is divided into two or more holes in the plate thickness direction of the outer diaphragm.

6. The method for manufacturing a joint structure between a box section column and an H-shaped steel beam according to claim 4 or 5, wherein the yield strength of the outer diaphragm is greater than the yield strength of a flange of the H-shaped steel beam.

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