Different diameter column-beam joint structure

Abstract

To provide different diameter column-beam joint structure that can reduce a welding amount as much as possible while securing sufficient stress transmission between a column and a beam in the different diameter column-beam joint structure in which a large-thickness panel core and a diaphragm are welded and joined.SOLUTION: In a different diameter column-beam joint structure 80A, a lower floor column 40 is weld and joined at bottom edges 13 of a panel core 10, a through-diaphragm 20A is weld and joined at top edges 12 of the panel core 10, and an upper floor column 50 with small cross-sectional dimension than the lower floor column 40 is weld and joined at an upper surface 21 of the through-diaphragm 20A. The top edge 12 of a panel plate 11 has a flat surface 15 up to an intermediate position and a single-bevel groove 16 from the intermediate position throughout the outside. A backing strip 30 is sandwiched between the flat surface 15 and the lower surface 22 of through-diaphragm 20A, and a plate thickness t8 of the backing strip 30 forms a root gap. A butt welding part 70 is provided at the space G2 formed with the single-bevel groove 16, the root gap, and the lower surface 22 of through-diaphragm 20A.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a joint structure for beams and columns with different diameters. [Background technology]

[0002] In steel-framed buildings where square steel pipes and the like are used as steel columns and H-shaped steel beams, and where H-shaped steel beams and the like are used as steel columns and beam joints, diaphragms such as through diaphragms and internal diaphragms are arranged above and below a rectangular cylindrical panel core (panel zone) that is rectangular in plan view (for example, square in plan view), the upper and lower floor columns (both steel columns) are welded to the top and bottom ends of the panel core, and steel beams are welded to each panel plate of the panel core, thereby forming a beam-column joint structure.

[0003] In addition to a structure in which steel columns of the same dimensions are used for the upper and lower floor columns, there is also a structure in which the dimensions of the upper floor columns are relatively smaller than those of the lower floor columns.A column-beam joint structure with lower and upper floor columns of different dimensions like this is called a differential diameter column-beam joint structure.

[0004] In a dissimilar beam-column joint structure, lower floor columns of the same shape and dimensions as the panel core are welded to the bottom end of a rectangular cylindrical panel core. On the other hand, upper floor columns, which are smaller than the lower floor columns and panel core, have through diaphragms or inner diaphragms welded to the top end of the panel core, and the lower ends of the upper floor columns are welded to the top surfaces of these diaphragms to form a dissimilar beam-column joint structure.

[0005] Panel cores come in two forms: one formed by welding four steel plates together into a rectangular tube (known as a four-sided box or four-sided panel box), and another formed using rectangular steel pipes. To ensure the rigidity and strength of the ends of the steel beams to which they are connected, the panel core panels are typically thick, and the through diaphragms and internal diaphragms welded to them are also typically thick. In both cases, full penetration welding is typically used to weld thick panel plates and diaphragms to ensure sufficient stress transfer between the column and beam. This often results in a large amount of welding, which requires more careful preheating and heat input management in accordance with the plate thickness than with conventional welding, often resulting in a high manufacturing load.

[0006] For these reasons, in a dissimilar diameter column-beam joint structure in which a thick panel core and a diaphragm are welded together, there is a demand for a dissimilar diameter column-beam joint structure in which the amount of welding can be reduced as much as possible.

[0007] Here, Patent Document 1 proposes a column-beam joint structure for connecting columns of different diameters, in which an inner diaphragm is welded to the upper end of a column-beam joint core, a lower floor column of the same dimensions is welded to the lower end of the column-beam joint core, and an upper floor column of smaller dimensions than the lower floor column and the column-beam joint core is welded to the inner diaphragm. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-190045 Summary of the Invention [Problem to be solved by the invention]

[0009] Even in the beam-column joint structure for joining dissimilar diameter columns described in Patent Document 1, the thick panel plate and the inner diaphragm are welded together using full penetration welding, which makes it difficult to resolve the above-mentioned issues, namely, the joints tend to require a large amount of welding, and preheating control and heat input control of the welds according to the plate thickness is required compared to general welding, which often results in a high manufacturing load.

[0010] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a dissimilar diameter column-beam joint structure in which a thick panel core and a diaphragm are welded together, in which the amount of welding can be reduced as much as possible while ensuring sufficient stress transmission between the columns and beams. [Means for solving the problem]

[0011] In order to achieve the above object, one aspect of the column-beam joint structure according to the present invention is as follows: A steel beam is welded to at least one panel plate of a rectangular panel core in plan view having four panel plates, a lower floor column formed of a square steel pipe is welded to the lower end of the panel core, a rectangular through diaphragm is welded to the upper end of the panel core in plan view, and an upper floor column formed of a square steel pipe with a cross-sectional dimension smaller than that of the lower floor column is welded to the upper surface of the through diaphragm, The upper end of the panel plate has a flat surface up to a midpoint, and a V-shaped groove extending from the midpoint to the outside, A backing metal is sandwiched between the flat surface and the lower surface of the through diaphragm, and the plate thickness of the backing metal forms a root gap; The present invention is characterized in that a butt weld is provided in the space formed by the V-groove, the root gap, and the underside of the through diaphragm.

[0012] According to this aspect, a through diaphragm is welded to the upper end of a panel core. The upper end of the panel plate is flat up to a midpoint, with a square groove extending from the midpoint to the outside. A backing metal is sandwiched between the flat surface and the underside of the through diaphragm, and the thickness of the backing metal forms a root gap. This results in a new welded joint (a new first welded joint) that is a partial penetration weld with a root gap, rather than the conventional full penetration weld. By applying this new welded joint, even when the panel plate and the through diaphragm are thick, sufficient stress transfer between the column and beam can be ensured while minimizing the amount of welding. Reducing the amount of welding also reduces the manufacturing burden, such as preheating and heat input management for the weld, which increases with plate thickness.

[0013] Here, "rectangular in plan view" means both a square and a rectangle in plan view, and also includes shapes with curved corners. When multiple steel beams are welded to a panel core, the steel beams may all be of the same composition, or step beams with steel beams of different compositions may be used.

[0014] In another aspect of the joint structure of the different diameter column and beam according to the present invention, A backing metal unit, which is made up of four backing metals arranged to form a rectangular frame, is sandwiched between the flat surface at the upper end of the panel core, which is rectangular in plan view, and the lower surface of the through diaphragm.

[0015] According to this aspect, the backing metal unit, in which four backing metals are arranged to form a rectangular frame, is sandwiched between the flat surface at the upper end of the rectangular panel core in a plan view and the underside of the through diaphragm, thereby ensuring a uniform root gap around the entire upper end of the panel core. Here, the backing metal unit may be formed by integrating the four backing metals to form a rectangular frame, or by sequentially arranging the four backing metals to form a rectangular frame. In the former case, the backing metal unit is easy to handle, which improves manufacturability when welding the through diaphragm to the panel core.

[0016] Another aspect of the different diameter column-beam joint structure according to the present invention is as follows: A steel beam is welded to at least one panel plate of a rectangular panel core in plan view having four panel plates, a lower floor column formed of a square steel pipe is welded to the lower end of the panel core, a rectangular through diaphragm is welded to the upper end of the panel core in plan view, and an upper floor column formed of a square steel pipe with a cross-sectional dimension smaller than that of the lower floor column is welded to the upper surface of the through diaphragm, The upper end of the panel plate has a flat surface up to a midpoint, and a trapezoidal countersink groove in a side view extending from the midpoint to the outside. The length of the bottom surface of the countersink groove forms a root gap; A butt weld is provided in the space formed by the countersunk groove and the underside of the through diaphragm.

[0017] According to this aspect, in a configuration in which a through diaphragm is welded to the upper end of a panel core, the upper end of the panel plate is flat up to a position midway, and a countersink groove that is trapezoidal in side view extends from the position midway to the outside, and the length of the bottom of the countersink groove forms a root gap, thereby forming a new welding joint configuration (a new second welding joint configuration) that is a partial penetration welding that ensures a root gap while eliminating the need for a backing metal, rather than the conventional general full penetration welding. By applying this new welding joint configuration, it is possible to minimize the amount of welding while ensuring sufficient stress transfer between the column and beam, even when the panel plate and the through diaphragm are thick.

[0018] Another aspect of the different diameter column-beam joint structure according to the present invention is as follows: A differential beam-column joint structure in which a steel beam is welded to at least one panel plate of a rectangular panel core in plan view having four panel plates, a lower floor column formed of a square steel pipe is welded to the lower end of the panel core, an inner diaphragm which is rectangular in plan view is welded to the inside of the upper end of the panel core, and an upper floor column formed of a square steel pipe with a cross-sectional dimension smaller than that of the lower floor column is welded to the upper surface of the inner diaphragm, The side end of the inner diaphragm has a flat surface up to a midpoint and a V-shaped groove extending from the midpoint to the outside, A backing metal is sandwiched between the flat surface and the inner surface of the panel plate, and the plate thickness of the backing metal forms a root gap; The method is characterized in that a butt weld is provided in a space formed by the V-groove, the root gap, and the inner surface of the panel plate.

[0019] According to this aspect, in a configuration in which the inner diaphragm is welded to the inside of the upper end of the panel core, the side end of the inner diaphragm is flat up to a position midway, there is a square groove from the midway position to the outside, a backing metal is sandwiched between the flat surface and the inner surface of the panel plate, and the thickness of the backing metal forms a root gap, thereby forming a new welding joint configuration (a new third welding joint configuration) that is a partial penetration welding that ensures a root gap rather than the conventional general full penetration welding. By applying this new welding joint configuration, it is possible to minimize the amount of welding while ensuring sufficient stress transmission between the column and the beam, even when the panel plate and the through diaphragm are thick.

[0020] In another aspect of the joint structure of the different diameter column and beam according to the present invention, The panel core is formed by welding four panel plates together, A backing metal for forming a panel core is disposed at the inner corner portion of the adjacent panel plates and extends in the axial direction of the panel plates, The method is characterized in that the linear backing metal is sandwiched between each panel plate of the panel core and the flat surface of the side end of the corresponding inner diaphragm.

[0021] According to this aspect, in a configuration in which a panel core is formed by welding four panel plates together, a backing metal is sandwiched between each panel plate and the flat surface of the side end of the corresponding inner diaphragm so as not to interfere with the panel core forming backing metal arranged at the inner corners of adjacent panel plates and extending in the axial direction of the panel plates.This means that even in a so-called four-sided box panel core equipped with panel core forming backing metal at the inner corners, a uniform root gap can be ensured around the entire circumference of the side end of the inner diaphragm.

[0022] Another aspect of the different diameter column-beam joint structure according to the present invention is as follows: A differential beam-column joint structure in which a steel beam is welded to at least one panel plate of a rectangular panel core in plan view having four panel plates, a lower floor column formed of a square steel pipe is welded to the lower end of the panel core, an inner diaphragm which is rectangular in plan view is welded to the inside of the upper end of the panel core, and an upper floor column formed of a square steel pipe with a cross-sectional dimension smaller than that of the lower floor column is welded to the upper surface of the inner diaphragm, The side end of the inner diaphragm has a flat surface up to a midpoint, and a trapezoidal countersink groove in a side view from the midpoint to the outside, The length of the bottom surface of the countersink groove forms a root gap; A butt weld is provided in the space formed by the countersunk groove and the inner surface of the panel plate.

[0023] According to this aspect, in a configuration in which the inner diaphragm is welded to the inside of the upper end of the panel core, the side end of the inner diaphragm is flat up to a position midway, and there is a countersunk groove that is trapezoidal in side view from the midpoint to the outside, and the length of the bottom of the countersunk groove forms a root gap, thereby forming a new welding joint configuration (a new fourth welding joint configuration) that is a partial penetration welding that does not require a backing metal but ensures a root gap, rather than the conventional general full penetration welding. By applying this new welding joint configuration, it is possible to minimize the amount of welding while ensuring sufficient stress transmission between the column and beam, even when the panel plate and the through diaphragm are thick.

[0024] In another aspect of the joint structure of the different diameter column and beam according to the present invention, The panel core is characterized in that it is formed by four panel plates welded together, or is formed from square steel pipes.

[0025] According to this aspect, regardless of whether the panel core is formed from a square steel pipe or a so-called four-sided box, a new welding joint form is formed between the panel plate and the diaphragm, which makes it possible to transmit stress between the columns and beams while minimizing the amount of welding as much as possible, even when the panel plate and the through diaphragm are thick.

[0026] In another aspect of the joint structure of the different diameter column and beam according to the present invention, The countersink groove has a bottom surface that is a distorted surface other than a flat surface.

[0027] According to this aspect, since the bottom surface of the countersink groove is a distorted surface other than a flat surface, even if the countersink groove bottom surface has various shapes depending on the processing method of the countersink groove, it is possible to provide variations in the shape of the countersink bottom surface (various countersink bottom surfaces are acceptable) on the premise that the desired length of the root gap is secured. Here, examples of distorted surfaces include a wavy surface and a curved surface.

[0028] In another aspect of the joint structure of the different diameter column and beam according to the present invention, The boundary between the bottom surface of the countersink groove and the inclined surface of the countersink groove has a curvature.

[0029] According to this aspect, the boundary between the bottom surface of the countersink groove and the inclined surface of the countersink has a curvature, and therefore, for example, the boundary between the bottom surface of the countersink and the inclined surface of the countersink is not a straight line (the two surfaces do not intersect via a straight line), which allows for leeway in machining the countersink groove. In other words, when continuously cutting from the inclined surface of the countersink to the bottom surface of the countersink, allowing for a curvature in the boundary allows for variation in the cutting method. [Effects of the Invention]

[0030] As can be understood from the above explanation, according to the dissimilar diameter column-beam joint structure of the present invention, in a dissimilar diameter column-beam joint structure in which a thick panel core and a diaphragm are welded together, it is possible to minimize the amount of welding while ensuring sufficient stress transmission between the columns and beams. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a vertical cross-sectional view of an example of a joint structure for connecting beams and columns with different diameters according to a first embodiment. [Figure 2] 10A and 10B are diagrams illustrating a conventional welding connection form between a panel plate and a through diaphragm. [Figure 3] FIG. 2 is an enlarged view of part III in FIG. 1, illustrating a novel first welding joint form. [Figure 4] FIG. 4 is a view taken in the direction of the arrow IV in FIG. [Figure 5] 10A and 10B are diagrams illustrating a new second welding joint form for forming a joint structure for a beam to a column with different diameters according to the second embodiment. [Figure 6] These are diagrams showing the side shapes of the countersink grooves formed according to the groove preparation machine, where (a) is a diagram showing a standard form, (b) is a diagram showing a form in which the countersink bottom surface has a distorted surface other than a flat surface, and (c) is a diagram showing a form in which the boundary between the countersink bottom surface and the countersink inclined surface of the countersink groove has a curvature. [Figure 7] FIG. 11 is a vertical cross-sectional view of an example of a joint structure for connecting beams and columns with different diameters according to a third embodiment. [Figure 8] FIG. 8 is an enlarged view of a portion VIII in FIG. 7, illustrating a new third welding joint form. [Figure 9] 9 is a view seen in the direction of the arrow IX in FIG. 7. [Figure 10] 10A and 10B are diagrams illustrating a new fourth welding joint form for forming a joint structure for a beam-to-column structure having different diameters according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, the joint structure for a beam-column structure having different diameters according to each embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially identical components are designated by the same reference numerals, and redundant description may be omitted.

[0033] [Different diameter column-beam joint structure according to the first embodiment] First, an example of a joint structure for dissimilar diameter columns and beams according to the first embodiment will be described with reference to Fig. 1 to Fig. 4. Here, Fig. 1 is a longitudinal cross-sectional view of an example of the joint structure for dissimilar diameter columns and beams according to the first embodiment, Fig. 3 is an enlarged view of part III in Fig. 1 and is a view illustrating a novel first welding joint form, and Fig. 4 is a view seen in the direction of arrow IV in Fig. 1.

[0034] The dissimilar diameter beam-column joint structure 80A (80) shown in Fig. 1 includes a panel core 10 that is square in plan view (an example of a rectangle) and is formed by welding together four (four) panel plates 11 with full penetration welding, a lower floor column 40 welded to the lower end 13 of the panel core 10, a through diaphragm 20A welded to the upper end 12 of the panel core 10, an upper floor column 50 welded to the upper surface 21 of the through diaphragm 20A, and a plurality of steel beams 60 welded to each panel plate 11. Here, the illustrated example shows the panel core 10 formed from a four-sided panel box, but the panel core may also be formed from a rectangular steel pipe that is square in plan view.

[0035] The width t1 of the panel core 10 can be set in the range of about 150 mm to 1000 mm, and the thickness t2 of the panel board 11 can be set in the range of about 6 mm to 50 mm.

[0036] The lower floor columns 40 are also formed from rectangular steel pipes that are square in plan view and have the same width t1 as the panel boards 11. A groove is provided at the upper end 41 of the lower floor columns 40, and a backing metal 35 is arranged on the inside of the lower floor columns 40. The groove of the lower floor columns 40 and the lower end 13 of the panel core 10 are welded together with a full penetration weld 75.

[0037] Here, specific welding methods in welded joints include, in addition to arc welding such as arc spot, arc stud, gas shielded arc, and plasma welding, various welding methods such as electro-slag welding, electron beam welding, and laser beam welding can be applied.

[0038] On each panel plate 11 of the panel core 10, there are stepped beams in which the side ends 61 and 62 of the steel frame beams 60A and 60B formed by two types of H-shaped steels with thicknesses t5 and t6 (t5 < t6) are welded. The illustrated example only shows the welded joint form (complete penetration weld 75) between the flange of the steel frame beam 60 and the panel plate 11. However, the web of the steel frame beam 60 and the panel plate 11 may also be welded by fillet welding, or the entire circumference of the steel frame beam 60 and the panel plate 11 may be welded by fillet welding.

[0039] The welded joint form between the through diaphragm 20 and the panel core 10 will be described in detail below. The upper column 50 connected to the upper surface 21 of the through diaphragm 20 is formed of a square steel pipe in plan view with a width t4 (t4 < t1) that is narrower than the panel core 10 and the lower column 40. A groove is provided at the lower end 51 of the upper column 50, a backing plate 35 is disposed inside the upper column 50, and the groove of the upper column 50 and the upper surface 21 of the through diaphragm 20A are welded by a complete penetration weld 75.

[0040] Here, before explaining the welded joint form between the through diaphragm 20 and the panel core 10 by referring to FIG. 3 which is an enlarged view of part III of FIG. 1, the welded joint form between the conventional panel plate and the through diaphragm will be explained by referring to FIG. 2. Here, FIG. 2 is a diagram for explaining the welded joint form between the conventional panel plate and the through diaphragm, and is shown in a manner corresponding to FIG. 3.

[0041] As shown in the figure, both the plate thickness t3 of the through diaphragm 20A and the plate thickness t2 of the panel plate 11 are thickened in order to ensure the rigidity and strength of the side ends 61 and 62 (see FIG. 1) of the steel frame beam 60 joined to the panel plate 11 and to ensure sufficient stress transmission between the columns and beams.

[0042] In the conventional welding joint between the panel plate 11 and the through diaphragm 20A, as shown in Figure 2, a groove 12' is provided at the upper end of the panel plate 11 across the entire width of the plate thickness, a backing metal 35 is placed on the back surface of the groove 12', and a full penetration weld 75 is formed in the large space G1 formed by the underside 22 of the through diaphragm 20A, the groove 12' of the panel plate 11, and the backing metal 35.

[0043] Here, the width t7 of the area of ​​the backing metal 35 exposed to the full penetration weld 75 forms a root gap.

[0044] As is clear from Figure 2, as the thickness of both the panel plate 11 and the through diaphragm 20A increases, the welding space G1 becomes larger and the amount of welding increases, resulting in a higher manufacturing load due to the need to manage the preheating and heat input of the welded parts according to the plate thickness.

[0045] Next, an example of a welding joint form (a new first welding joint form) of the panel plate 11 and the through diaphragm 20A that form the different diameter column-beam joint structure 80A, which replaces the conventional welding joint form shown in Figure 2, will be described with reference to Figure 3.

[0046] At the upper end 12 of the panel plate 11, a flat surface 15 is formed from the inside to a midpoint, and a V-shaped groove 16 having a groove depth t9 is provided from the midpoint to the outside.

[0047] A backing metal 30 is sandwiched between the flat surface 15 and the lower surface 22 of the through diaphragm 20A, and a plate thickness t8 of the backing metal 30 forms a root gap. Here, the plate thickness t8 forming the root gap can be set to about 6 mm to 9 mm.

[0048] A butt weld 70 is formed in a space G2 formed by the V-shaped groove 16, the plate thickness t8 (root gap) of the backing metal 30, and the lower surface 22 of the through diaphragm 20A.

[0049] In the illustrated welded joint configuration, the backing metal 30 is inserted partway through the upper end 12 of the panel plate 11, so the gap G2 that is formed is significantly smaller than the gap G1 in the conventional welded joint configuration shown in Figure 2. Even though the gap G2 is smaller, unlike conventional partial penetration welding, the plate thickness t8 of the inserted backing metal 30 ensures a sufficient root gap.

[0050] Therefore, this is a new welding method that is neither the conventional full penetration welding nor the partial penetration welding, and is a welding joint method that ensures sufficient stress transmission between the columns and beams while reducing the amount of welding as much as possible.

[0051] Here, as shown in Figure 4, a backing metal unit 30A in which four backing metals 30 are integrated to form a rectangular frame is used, and this backing metal unit 30A is placed on the flat surface 15 of the upper end 12 of a panel core 10 which is rectangular in plan view.The lower surface 22 of the through diaphragm 20A is placed on top of the backing metal unit 30A, and a butt weld 70 is formed along the outer periphery of the backing metal unit 30A, making it possible to weld the panel core 10 and the through diaphragm 20A together with good manufacturability.

[0052] The dimensions of the four backing metals 30 constituting the backing metal unit 30A may all be the same or may not all be the same, and for example, two may have the same dimensions and the other two may have different dimensions, as long as the result is a rectangular frame shape as shown in the example shown. An example of a configuration in which two backing metals have different dimensions is a configuration in which a pair of parallel long backing metals are connected to a pair of perpendicular short backing metals.

[0053] [Different diameter column beam joint structure according to the second embodiment] Next, an example of a joint structure for dissimilar diameter columns and beams according to the second embodiment will be described with reference to Fig. 5. Here, Fig. 5 is a diagram illustrating a new second welding joint form that forms the joint structure for dissimilar diameter columns and beams according to the second embodiment.

[0054] The illustrated joint structure 80B for a beam and a column with different diameters is the same as the joint structure 80A for a beam and a column with different diameters shown in FIGS. 1 and 3, except for the welding joint form between the panel plate 11 and the through diaphragm 20A.

[0055] In the illustrated welded joint form (new second welded joint form) of the panel plate 11 and the through diaphragm 20A, the upper end 12 of the panel plate 11 has a flat surface 15 from the inside to a midpoint, and a countersink groove 17 that is trapezoidal in side view and has a groove depth t11 extending from the midpoint to the outside.

[0056] The countersink groove 17 has a countersink inclined surface 18 and a countersink bottom surface 19, and the length t10 of the countersink bottom surface 19 forms a root gap. The countersink inclined surface 18 ensures the groove angle, and the groove depth t11, which is the depth to the countersink bottom surface 19, ensures the penetration depth.

[0057] A butt weld 70 is formed in a space G3 formed by the countersink groove 17 and the lower surface 22 of the through diaphragm 20A.

[0058] In the welded joint shown in the figure, a countersunk groove 17 is provided midway along the top end 12 of the panel plate 11, so the gap G3 formed is significantly smaller than the conventional gap G1, similar to the gap G2 in the welded joint shown in Figure 3. Despite the small gap G3, unlike conventional partial penetration welding, the length t10 of the countersunk bottom surface 19 of the countersunk groove 17 ensures a sufficient root gap. Therefore, similar to the welded joint shown in Figure 3, this is a new welding form that is neither conventional full penetration welding nor partial penetration welding, and ensures sufficient stress transfer between the column and beam while minimizing the amount of weld required.

[0059] Furthermore, unlike the welding joint configuration shown in FIG. 3, the backing metal 30 is not required, which reduces the number of parts and further improves manufacturability.

[0060] Here, modified examples of the side shape of the countersink groove will be described with reference to Fig. 6. Fig. 6(a) is a diagram showing the standard form, Fig. 6(b) is a diagram showing a form in which the countersink bottom surface has a distorted surface other than a flat surface, and Fig. 6(c) is a diagram showing a form in which the boundary between the countersink bottom surface and the countersink inclined surface of the countersink groove has a curvature.

[0061] The countersink groove 17 shown in FIG. 6(a) has a shape in which a countersink inclined surface 18 and a countersink bottom surface 19, both of which are flat surfaces, rub against each other via a boundary line 17a.

[0062] 6(b), the countersink groove 17A has a shape consisting of a flat countersink slope 18 and a distorted countersink bottom surface 19A. The distorted surface includes various surfaces other than flat surfaces, such as a curved surface as shown in the example and a wavy surface (not shown).

[0063] On the other hand, the countersink groove 17B shown in FIG. 6(c) has a shape in which a countersink inclined surface 18 and a countersink bottom surface 19, both of which are flat surfaces, rub against each other via a boundary curvature 17b.

[0064] As shown in Figure 6(b), since the seat bottom surface 19A of the seat groove 17A is a distorted surface other than a flat surface, even if the seat bottom surface 19A forms a surface of various shapes depending on the processing method of the seat groove 17A, it is possible to provide variations in the shape of the seat bottom surface 19A, provided that a root gap of the desired length is secured.

[0065] Furthermore, as shown in Figure 6(c), the boundary between the seat bottom surface 19 and the seat inclined surface 18 of the seat groove 17B has a curvature 17b. For example, since the boundary between the seat bottom surface 19 and the seat inclined surface 18 is not a straight line, it is possible to allow for leeway in processing the seat groove 17B, and when continuously cutting from the seat inclined surface 18 to the seat bottom surface 19, by allowing for the curvature 17b of the boundary, it is possible to provide variation in the cutting method.

[0066] [Different diameter column beam joint structure according to the third embodiment] Next, an example of a joint structure for dissimilar diameter columns and beams according to a third embodiment will be described with reference to Fig. 7 to Fig. 9. Here, Fig. 7 is a longitudinal sectional view of an example of the joint structure for dissimilar diameter columns and beams according to the third embodiment, Fig. 8 is an enlarged view of part VIII in Fig. 7 and is a view illustrating a new third welding joint form, and Fig. 9 is a view seen from the direction of arrow IX in Fig. 7.

[0067] The dissimilar diameter column-beam joint structure 80C (80) shown in Figure 7 differs from the dissimilar diameter column-beam joint structures 80A, 80B having a through diaphragm 20A in that an inner diaphragm 20B of plate thickness t3 is welded to the inner surface of the upper end 12 of the panel core 10, and the lower end 51 of the upper floor column 50 is welded to the upper surface 21 of the inner diaphragm 20B.

[0068] First, with reference to FIG. 8, an example of a welding connection form (a new third welding connection form) between the panel plate 11 and the inner diaphragm 20B that forms a joint structure 80C of dissimilar diameter columns and beams according to the third embodiment will be described.

[0069] At the side end 23 of the inner diaphragm 20B, a flat surface 24 is formed from the inside to a midpoint, and a V-shaped groove 25 having a groove depth t9 is provided from the midpoint to the outside.

[0070] A backing metal 30 is sandwiched between the flat surface 24 and the inner surface 14 of the panel plate 11, and the plate thickness t8 of the backing metal 30 forms a root gap.

[0071] A butt weld 70 is formed in a space G2 formed by the V-shaped groove 25, the plate thickness t8 (root gap) of the backing metal 30, and the inner surface 14 of the panel plate 11.

[0072] In the illustrated welding joint form, the backing metal 30 is inserted up to a position halfway through the side end 23 of the inner diaphragm 20B, so the gap G2 formed is small, similar to the welding joint form shown in Figure 3, and the plate thickness t8 of the inserted backing metal 30 ensures a sufficient root gap.

[0073] 9, in this welding joint configuration, the panel core 10 is formed by welding four panel plates 11 together with full penetration welding, and panel core-forming backing metals 38 extending in the axial direction of the panel plates 11 are disposed at the inner corners of adjacent panel plates 11. Therefore, the backing metals 30 are sandwiched between each panel plate 11 and the flat surface 24 of the side end 23 of the corresponding inner diaphragm 20B so as not to interfere with each panel core-forming backing metal 38 at the inner corners of the panel core 10. As a result, even in a four-sided box panel core 10 equipped with panel core-forming backing metals 38 at the inner corners, a uniform root gap can be ensured around the entire periphery of the side end 23 of the inner diaphragm 20B.

[0074] [Fourth embodiment of a different diameter column-beam joint structure] Next, an example of a joint structure for a beam to a column with different diameters according to the fourth embodiment will be described with reference to Fig. 10. Here, Fig. 10 is a view illustrating a new fourth welding joint form that forms the joint structure for a beam to a column with different diameters according to the fourth embodiment.

[0075] The illustrated joint structure 80D for a beam and a column with different diameters is the same as the joint structure 80C for a beam and a column with different diameters shown in FIGS. 7 and 8, except for the welding joint form between the panel plate 11 and the inner diaphragm 20B.

[0076] In the illustrated welded joint form (new fourth welded joint form) of the panel plate 11 and the inner diaphragm 20B, the side end 23 of the inner diaphragm 20B has a flat surface 24 from the inside to a midpoint, and a countersink groove 26 that is trapezoidal in side view and has a groove depth t11 extending from the midpoint to the outside.

[0077] The countersink groove 26 has a countersink inclined surface 27 and a countersink bottom surface 28, and the length t10 of the countersink bottom surface 28 forms a root gap.

[0078] A butt weld 70 is formed in a space G3 formed by the countersink groove 26 and the inner surface 14 of the panel plate 11.

[0079] In the welded joint configuration shown in the figure, a countersunk groove 26 is provided from a midpoint on the side end 23 of the inner diaphragm 20B, so the gap G3 formed is significantly smaller than the conventional gap G1, similar to the gap G2 in the welded joint configuration shown in Figure 8. Even though the gap G3 is small, unlike conventional partial penetration welding, a sufficient root gap is ensured by the length t10 of the countersunk bottom surface 28 of the countersunk groove 26. Therefore, similar to the welded joint configuration shown in Figure 8, this is a new welding configuration that is neither conventional full penetration welding nor partial penetration welding, and it is a welding joint configuration that ensures sufficient stress transmission between the column and the beam while minimizing the amount of weld.

[0080] Furthermore, unlike the welding joint configuration shown in FIG. 8, the backing metal 30 is not required, which reduces the number of parts and further improves manufacturability.

[0081] [Calculation method for diaphragm thickness] When calculating the required thickness of a diaphragm (through diaphragm, internal diaphragm), the thickness of the yield line, the yield moment per unit length of the yield line, and the full plastic moment are designed in the calculation of the diaphragm's out-of-plane bending rigidity, yield out-of-plane bending rigidity, and full plastic out-of-plane bending strength based on the smallest value among the diaphragm thickness, panel plate thickness, and groove depth.

[0082] Here, the yield bending moment per unit length of the yield line formed in the diaphragm is LD M y is expressed by the following formula (1), and the yield bending moment per unit length of the yield line formed in the panel plate is LP M y is expressed by the following formula (2), and the yield bending moment per unit length of the butt weld is LW M y is expressed by the following formula (3), and the thickness of the diaphragm can be designed using the minimum value of formulas (1) to (3).

[0083]

number

[0084]

number

[0085]

number

[0086] It should be noted that the present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0087] 10: Panel core 11: Panel board 12:Top edge 13: Bottom edge 14: Inner self 15:Flat surface 16: L-shaped groove 17,17A,17B:Spot digging groove 17a: straight line 17b: Curvature 18: Seat-dug slope 19: Bottom of the pit 19A: Bottom of countersunk hole (distorted surface) 20: Diaphragm 20A: Through diaphragm (diaphragm) 20B: Inner diaphragm (diaphragm) 21:Top surface 22: Bottom surface 23: Side edge 24:Flat surface 25: L-shaped groove 26: Countersunk groove 27: Seat-dug slope 28: Bottom of the pit 30: Backing plate 30A: Backing metal unit 35: Backing plate 38: Panel core forming backing metal 40: Lower floor pillar (steel pillar) 41:Top edge 50: Upper floor pillar (steel pillar) 51: Bottom edge 60, 60A, 60B: Steel beam 61,62: Side edge 70: Butt weld 75: Full penetration weld (an example of a butt weld) 80,80A,80B,80C,80D: Different diameter column and beam joint structure G1,G2,G3: Space

Claims

1. A steel beam is welded to at least one panel plate of a rectangular panel core in plan view having four panel plates, a lower floor column formed of a square steel pipe is welded to the lower end of the panel core, a rectangular through diaphragm is welded to the upper end of the panel core in plan view, and an upper floor column formed of a square steel pipe with a cross-sectional dimension smaller than that of the lower floor column is welded to the upper surface of the through diaphragm, The upper end of the panel plate has a flat surface up to a midpoint, and a trapezoidal countersink groove in a side view extending from the midpoint to the outside. The length of the bottom surface of the countersink groove forms a root gap; A dissimilar diameter column-beam joint structure, characterized in that a butt weld is provided in the space formed by the countersunk groove and the underside of the through diaphragm.

2. 2. The joint structure of claim 1, wherein the bottom surface of the countersink groove is a distorted surface other than a flat surface.

3. 2. The joint structure of claim 1, wherein a boundary between the bottom surface of the countersink groove and the inclined surface of the countersink groove has a curvature.

4. The panel core is formed by welding four panel plates together, or is formed from a square steel pipe.

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