Column-beam joint structure with different diameters

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 column-beam joint structure with different diameters.

Background Art

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

[0003] In addition to the form in which steel columns of the same dimensions are applied to the upper floor columns and the lower floor columns, there is a form in which the dimensions of the upper floor columns are relatively smaller than those of the lower floor columns. A column-beam joint structure having lower floor columns and upper floor columns with different dimensions is called a column-beam joint structure with different diameters.

[0004] In the column-beam joint structure with different diameters, a lower floor column having the same shape and dimensions as the panel core is welded to the lower end of the rectangular tube-shaped panel core. On the other hand, an upper floor column having smaller dimensions than the lower floor column or the panel core is welded with a through diaphragm or an internal diaphragm to the upper end of the panel core, and the lower end of the upper floor column is welded to the upper surface of these diaphragms, thereby forming a column-beam joint structure with different diameters.

[0005] The panel core can be formed by welding four steel plates to each other in a square tube shape (referred to as a four-sided box or four-sided panel box), or by applying square steel pipes. However, in order to ensure the rigidity and load-bearing capacity of the ends of the steel frame beams to be joined, the thickness of the panel plates of the panel core increases, and the thickness of the continuous diaphragms and internal diaphragms welded to them also generally increases. In all cases of welding joints between thick panel plates and diaphragms, full penetration welding is generally applied to ensure sufficient stress transfer between the columns and beams. Therefore, it is likely to become a joint with a large amount of welding, requiring preheating management and heat input management of the welded parts according to the plate thickness compared to general welding, and often having the problem of high manufacturing load.

[0006] From the above, in a different-diameter column-beam joint structure where a thick panel core and a diaphragm are welded together, a different-diameter column-beam joint structure that can minimize the amount of welding as much as possible is desired.

[0007] Here, Patent Document 1 proposes a column-beam joint structure for different-diameter column joints in which an internal diaphragm is welded to the upper end of the column-beam joint core, a lower-story column of the same size is welded to the lower end of the column-beam joint core, and an upper-story column with a smaller size than the lower-story column and the column-beam joint core is welded to the internal diaphragm.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] Even in the column-beam joint structure for joining columns of different diameters described in Patent Document 1, since the thick panel plate and the inner diaphragm are welded together by full penetration welding, it is difficult to solve the above-mentioned problems, that is, it is likely to become a joint part with a large amount of welding, and compared with general welding, preheating management and heat input management of the welded part according to the plate thickness are required, and the manufacturing load often becomes high.

[0010] The present invention has been made in view of the above problems, and in a column-beam joint structure in which a panel core with a thick plate thickness and a diaphragm are welded together, an object thereof is to provide a column-beam joint structure with different diameters that can reduce the amount of welding as much as possible while ensuring sufficient stress transmission between the columns and beams.

Means for Solving the Problems

[0011] To achieve the above object, one aspect of the column-beam joint structure according to the present invention is A steel beam is welded to at least one of the panel plates of a rectangular panel core in plan view having four panel plates, a lower column formed by a square steel pipe is welded to the lower end of the panel core, a continuous diaphragm in plan view is welded to the upper end of the panel core, and an upper column formed by a square steel pipe having a smaller cross-sectional dimension than the lower column is welded to the upper surface of the continuous diaphragm. A column-beam joint structure with different diameters, characterized in that At the upper end of the panel plate, the middle part is a flat surface, and there is an L-shaped groove from the middle part to the outside. A backing plate is sandwiched between the flat surface and the lower surface of the continuous diaphragm, and the plate thickness of the backing plate forms a root gap. A butting weld is provided in the space formed by the L-shaped groove, the root gap, and the lower surface of the continuous diaphragm.

[0012] According to this aspect, in a form where a through diaphragm is welded and joined to the upper end of the panel core, up to the middle position of the upper end of the panel plate is a flat surface, there is a J-shaped groove extending outward from the middle position, a backing plate is sandwiched between the flat surface and the lower surface of the through diaphragm, and the plate thickness of the backing plate forms a root gap, so that a new welding joint form (a new first welding joint form), such as a partial penetration welding with a root gap secured, is formed instead of the conventional general full penetration welding. By applying this new welding joint form, even when the plate thicknesses of the panel plate and the through diaphragm are thick, it is possible to minimize the welding amount while ensuring sufficient stress transmission between the column and beam. By reducing the welding amount, it is also possible to reduce the manufacturing load such as preheating management and heat input management of the welded part, which increases according to the plate thickness.

[0013] Here, "rectangular in plan view" means including both a square and a rectangle in plan view, and also includes a shape with curved corners. When a plurality of steel beams are welded and joined to the panel core, the form in which all the steel beams of the same type are applied may be used, or a stepped beam provided with steel beams of different types may be applied.

[0014] Also, in another aspect of the different-diameter column-beam joint structure according to the present invention, A backing plate unit in which four backing plates are arranged in a rectangular frame shape is sandwiched between the flat surface at the upper end of the panel core that is rectangular in plan view and the lower surface of the through diaphragm.

[0015] According to this aspect, a backing metal unit in which four backing metals are arranged in a rectangular frame shape is sandwiched between the flat surface at the upper end of a panel core that is rectangular in plan view and the lower surface of a continuous diaphragm, thereby ensuring a uniform root gap over the entire circumference of the upper end of the panel core. Here, the backing metal unit may be integrated such that the four backing metals form a rectangular frame shape, or may be formed by sequentially installing the four backing metals in a rectangular frame shape. In the former case, since the handling property of the backing metal unit is good, the manufacturability when welding and joining the continuous diaphragm to the panel core is improved.

[0016] Also, another aspect of the different-diameter column-beam joint structure according to the present invention is A steel beam is welded and joined to at least one of the panel plates of a panel core that is rectangular in plan view and includes four panel plates, a lower-story column formed of a square steel pipe is welded and joined to the lower end of the panel core, a continuous diaphragm that is rectangular in plan view is welded and joined to the upper end of the panel core, and an upper-story column formed of a square steel pipe having a smaller cross-sectional dimension than the lower-story column is welded and joined to the upper surface of the continuous diaphragm. The different-diameter column-beam joint structure is characterized in that At the upper end of the panel plate, there is a flat surface up to an intermediate position, and a seat-cutting opening that is trapezoidal in side view extends outward from the intermediate position. The length of the seat-cutting bottom surface of the seat-cutting opening forms a root gap. A butting weld portion is provided in a space formed by the seat-cutting opening and the lower surface of the continuous diaphragm.

[0017] According to this aspect, in a form where a through diaphragm is welded and joined to the upper end of the panel core, up to the middle position of the upper end of the panel plate is a flat surface, and there is a pedestal-shaped gouging groove extending outward from the middle position in a side view. The length of the gouging bottom surface of the gouging groove forms a root gap, thereby forming a new welding joint form (new second welding joint form) such as a partial penetration welding that secures the root gap while eliminating the need for backing metal, rather than the conventional general full penetration welding. By applying this new welding joint form, even when the plate thickness of the panel plate and the through diaphragm is thick, the welding amount can be minimized as much as possible while ensuring sufficient stress transmission between the columns and beams.

[0018] Moreover, another aspect of the different-diameter column-beam joint structure according to the present invention is A steel beam is welded and joined to at least one of the panel plates of a panel core that is rectangular in plan view and has four panel plates. A lower-story column formed of a square steel pipe is welded and joined to the lower end of the panel core. An inner diaphragm that is rectangular in plan view is welded and joined to the inner side of the upper end of the panel core. An upper-story column formed of a square steel pipe with a smaller cross-sectional dimension than the lower-story column is welded and joined to the upper surface of the inner diaphragm. It is a different-diameter column-beam joint structure, At the side end of the inner diaphragm, up to the middle position is a flat surface, and there is an L-shaped gouging groove extending outward from the middle position, 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, Characterized in that a butting weld is provided in the space formed by the L-shaped gouging groove, the root gap, and the inner surface of the panel plate.

[0019] According to this aspect, in a form where an inner diaphragm is welded and joined to the inside of the upper end of the panel core, up to the middle position of the side end of the inner diaphragm is a flat surface, and there is an L-shaped groove starting from the middle position and extending outward. A backing plate is sandwiched between the flat surface and the inner surface of the panel plate, and the plate thickness of the backing plate forms a root gap, thereby forming a new welding joint form (new third welding joint form), such as partial penetration welding with a root gap ensured, rather than the conventional general full penetration welding. And by applying this new welding joint form, even when the plate thicknesses of the panel plate and the through diaphragm are thick, it is possible to minimize the welding amount while ensuring sufficient stress transmission between the columns and beams.

[0020] Also, in another aspect of the different-diameter column-beam joint structure according to the present invention, The panel core is formed by welding and joining four panel plates to each other. At the inner corner portions of adjacent panel plates, backing plates for forming the panel core extending in the axial direction of the panel plate are arranged. It is characterized in that the linear backing plate is sandwiched between each panel plate of the panel core and the flat surface of the corresponding side end of the inner diaphragm.

[0021] According to this aspect, in a form where a panel core is formed by welding and joining four panel plates to each other, so as not to interfere with the backing plates for forming the panel core extending in the axial direction of the panel plate arranged at the inner corner portions of adjacent panel plates, and a backing plate is sandwiched between each panel plate and the flat surface of the corresponding side end of the inner diaphragm. Thus, even in a so-called four-sided box panel core provided with backing plates for forming the panel core at the inner corner portions, an equal root gap can be ensured over the entire circumference of the side end of the inner diaphragm.

[0022] Also, another aspect of the different-diameter column-beam joint structure according to the present invention is In a different-diameter column-beam joint structure, a steel frame beam is welded to at least one of the panel plates of a panel core that is rectangular in plan view and has four panel plates. A lower-story column formed of a square steel pipe is welded to the lower end of the panel core. An inner diaphragm that is rectangular in plan view is welded to the inside of the upper end of the panel core. An upper-story column formed of a square steel pipe with a smaller cross-sectional dimension than the lower-story column is welded to the upper surface of the inner diaphragm. At the side end of the inner diaphragm, there is a flat surface up to an intermediate position, and a seat excavation opening that is trapezoidal in side view extends outward from the intermediate position. The length of the seat excavation bottom surface of the seat excavation opening forms a root gap. A butting weld is provided in a space formed by the seat excavation opening and the inner surface of the panel plate.

[0023] According to this aspect, in a form where an inner diaphragm is welded to the inside of the upper end of the panel core, up to an intermediate position at the side end of the inner diaphragm is a flat surface, and there is a seat excavation opening that is trapezoidal in side view extending outward from the intermediate position. Since the length of the seat excavation bottom surface of the seat excavation opening forms a root gap, a new welding joint form (a new fourth welding joint form), such as a partial penetration weld that secures a root gap while eliminating the need for backing bars, is formed instead of the conventional general full penetration weld. By applying this new welding joint form, even when the panel plate and the through diaphragm have a thick plate thickness, the welding amount can be minimized as much as possible while ensuring sufficient stress transmission between the column and the beam.

[0024] Also, in another aspect of the different-diameter column-beam joint structure according to the present invention, The panel core is characterized by being formed by welding four panel plates to each other or being formed of a square steel pipe.

[0025] According to this aspect, regardless of whether the panel core is formed by 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. Thus, even when the plate thickness of the panel plate and the through diaphragm is thick, it is possible to reduce the welding amount as much as possible while enabling stress transmission between the columns and beams.

[0026] Also, in another aspect of the different-diameter column-beam joint structure according to the present invention, It is characterized in that the bottom surface of the socket excavation of the socket excavation tip is a distorted surface other than a flat surface.

[0027] According to this aspect, since the bottom surface of the socket excavation of the socket excavation tip is a distorted surface other than a flat surface, even when the bottom surface of the socket excavation forms surfaces of various forms depending on the method of processing the socket excavation tip, it is possible to vary the shape of the bottom surface of the socket excavation (allow various bottom surfaces of the socket excavation) on the premise that a root gap of a desired length is ensured. Here, examples of the distorted surface include a wavy surface and a curved surface.

[0028] Also, in another aspect of the different-diameter column-beam joint structure according to the present invention, It is characterized in that the boundary between the bottom surface of the socket excavation of the socket excavation tip and the socket excavation inclined surface has a curvature.

[0029] According to this aspect, since the boundary between the bottom surface of the socket excavation of the socket excavation tip and the socket excavation inclined surface has a curvature, for example, since the boundary between the bottom surface of the socket excavation and the socket excavation inclined surface is not a straight line (the two surfaces do not intersect via a straight line), a margin can be provided in the processing of the socket excavation tip. That is, when continuously performing cutting processing from the socket excavation inclined surface to the bottom surface of the socket excavation, by allowing the curvature of their boundary, variations can be provided in the cutting processing method.

Effects of the Invention

[0030] As can be understood from the above description, according to the different-diameter column-beam joint structure of the present invention, in the different-diameter column-beam joint structure where a panel core with a large plate thickness and a diaphragm are welded and joined, while ensuring sufficient stress transmission between the column and the beam, the welding amount can be reduced as much as possible.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying out the Invention

[0032] Hereinafter, the stepped column-beam joint structure according to each embodiment will be described with reference to the attached drawings. In the present specification and drawings, substantially the same components may be denoted by the same reference numerals, and redundant descriptions may be omitted.

[0033] [Stepped Column-Beam Joint Structure According to the First Embodiment] First, with reference to FIGS. 1 to 4, an example of the stepped column-beam joint structure according to the first embodiment will be described. Here, FIG. 1 is a longitudinal sectional view of an example of the stepped column-beam joint structure according to the first embodiment, FIG. 3 is an enlarged view of part III of FIG. 1, which is a view for explaining a new first welding joint form, and FIG. 4 is a view seen in the direction of arrow IV in FIG. 1.

[0034] The stepped column-beam joint structure 80A (80) shown in FIG. 1 includes a panel core 10 having a square shape (an example of a rectangle) in plan view, which is formed by welding four (four) panel plates 11 to each other by full penetration welding; a lower 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 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, in the illustrated example, the panel core 10 is formed by a four-sided panel box, but the panel core may be formed by a square steel pipe having a square shape 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 plate 11 can be set in the range of about 6 mm to 50 mm.

[0036] The lower column 40 is also formed by a square steel pipe having the same width t1 as the panel plate 11. A groove is provided at the upper end 41 of the lower column 40, a backing plate 35 is disposed inside the lower column 40, and the groove of the lower column 40 and the lower end 13 of the panel core 10 are welded and joined by 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] Each panel plate 11 of the panel core 10 has stepped beams in which the respective side ends 61, 62 of the steel frame beams 60A, 60B formed by two types of H-shaped steels with thicknesses t5, t6 (t5 < t6) are welded. The illustrated example only shows the welding 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 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 welding 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 welding joint form between the through diaphragm 20 and the panel core 10 with reference to FIG. 3, which is an enlarged view of part III of FIG. 1, the welding joint form between the conventional panel plate and the through diaphragm will be explained with reference to FIG. 2. Here, FIG. 2 is a diagram for explaining the welding 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 to ensure the rigidity and load-bearing capacity of the side ends 61, 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] As shown in FIG. 2, in the welding joint form of the conventional panel plate 11 and the through diaphragm 20A, a groove 12' extending across the entire width of the plate thickness is provided at the upper end of the panel plate 11, and a backing plate 35 is disposed on the back surface thereof. A complete penetration weld 75 is formed in a large space G1 formed by the lower surface 22 of the through diaphragm 20A, the groove 12' of the panel plate 11, and the backing plate 35.

[0043] Here, the width t7 of the region exposed to the complete penetration weld 75 in the backing plate 35 forms a root gap.

[0044] As is also apparent from FIG. 2, as the plate thicknesses of both the panel plate 11 and the through diaphragm 20A increase, the welding space G1 becomes larger and the welding amount increases, resulting in a higher manufacturing load due to preheating management and heat input management of the welded joint according to the plate thickness.

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

[0046] At the upper end 12 of the panel plate 11, the inner side to the middle position is a flat surface 15, and a groove-shaped groove 16 with a groove depth t9 is provided from the middle position to the outside.

[0047] A backing plate 30 is sandwiched between the flat surface 15 and the lower surface 22 of the through diaphragm 20A, and the plate thickness t8 of the backing plate 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 butting weld 70 is formed in a space G2 formed by the groove-shaped groove 16, the plate thickness t8 (root gap) of the backing plate 30, and the lower surface 22 of the through diaphragm 20A.

[0049] In the welding joint form of the illustrated example, since the backing plate 30 is inserted up to a position in the middle of the upper end 12 of the panel plate 11, the formed gap G2 becomes significantly smaller than the gap G1 in the conventional welding joint form shown in FIG. 2. While the gap G2 becomes smaller, unlike the conventional partial penetration welding, the root gap is sufficiently ensured by the plate thickness t8 of the inserted backing plate 30.

[0050] Therefore, it becomes a new welding form that is neither the conventional full penetration welding nor the partial penetration welding, and it becomes a welding joint form that ensures sufficient stress transmission between the column and the beam while reducing the welding amount as much as possible.

[0051] Here, as shown in FIG. 4, using a backing plate unit 30A in which four backing plates 30 are integrated so as to form a rectangular frame shape, this backing plate unit 30A is placed on the flat surface 15 of the upper end 12 of the panel core 10 having a rectangular shape in plan view, the lower surface 22 of the through diaphragm 20A is placed on the backing plate unit 30A, and by forming a butting weld portion 70 along the outer periphery of the backing plate unit 30A, it becomes possible to perform the welding joint of the panel core 10 and the through diaphragm 20A with good workability.

[0052] In addition, the dimensions of the four backing plates 30 constituting the backing plate unit 30A may all be the same, or they may not all be the same. For example, two of them may have the same dimensions and the other two may have different dimensions, etc., as long as a rectangular frame shape can be formed as in the illustrated example. Examples of the form in which the dimensions of every two are different include a form in which a pair of parallel long backing plates and a pair of short backing plates orthogonal to them are connected to each other.

[0053] [Heterogeneous column-beam joint structure according to the second embodiment] Next, with reference to FIG. 5, an example of the heterogeneous column-beam joint structure according to the second embodiment will be described. Here, FIG. 5 is a diagram for explaining a new second welding joint form that forms the heterogeneous column-beam joint structure according to the second embodiment.

[0054] The illustrated column-beam joint structure 80B with different diameters is the same as the column-beam joint structure 80A shown in Figs. 1 and 3 except for the welding joint form of the panel plate 11 and the continuous diaphragm 20A.

[0055] In the welding joint form of the illustrated panel plate 11 and the continuous diaphragm 20A (the new second welding joint form), the upper end 12 of the panel plate 11 has a flat surface 15 from the inner side to the middle position, and a counterbored groove 17 with a bevel depth t11 in the shape of a bench in side view is provided from the middle position to the outer side.

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

[0057] A butting weld 70 is formed in the space G3 formed by the counterbored groove 17 and the lower surface 22 of the continuous diaphragm 20A.

[0058] In the welding joint form of the illustrated example, since the counterbored groove 17 is provided from the middle position of the upper end 12 of the panel plate 11, the formed gap G3 is much smaller than the conventional gap G1, similar to the gap G2 in the welding joint form shown in Fig. 3. While the gap G3 becomes smaller, different from the conventional partial penetration welding, the root gap is sufficiently ensured by the length t10 of the counterbored bottom surface 19 of the counterbored groove 17. Therefore, similar to the welding joint form shown in Fig. 3, it is a new welding form that is neither the conventional full penetration welding nor partial penetration welding, and it is a welding joint form that ensures sufficient stress transmission between the column and the beam while reducing the welding amount as much as possible.

[0059] Also, different from the welding joint form shown in Fig. 3, since the backing plate 30 can be made unnecessary, the number of parts can be reduced, and the manufacturability becomes even better.

[0060] Here, with reference to FIG. 6, a modification of the side surface shape of the bottom excavation tip will be described. FIG. 6(a) is a diagram showing the standard form, FIG. 6(b) is a diagram showing a form in which the bottom surface of the bottom excavation 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 bottom excavation bottom surface and the bottom excavation inclined surface of the bottom excavation tip has a curvature.

[0061] The bottom excavation tip 17 shown in FIG. 6(a) has a shape in which the bottom excavation inclined surface 18 and the bottom excavation bottom surface 19, both of which are flat surfaces, abut via a straight line 17a at the boundary.

[0062] On the other hand, the bottom excavation tip 17A shown in FIG. 6(b) has a shape composed of a bottom excavation inclined surface 18 made of a flat surface and a bottom excavation bottom surface 19A that is a distorted surface. Here, the distorted surface includes various surfaces other than a flat surface, such as a curved surface as shown in the illustrated example and a wavy surface (not shown).

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

[0064] As shown in FIG. 6(b), since the bottom excavation bottom surface 19A of the bottom excavation tip 17A is a distorted surface other than a flat surface, even when the bottom excavation bottom surface 19A forms surfaces of various forms depending on the processing method of the bottom excavation tip 17A, variations can be given to the shape of the bottom excavation bottom surface 19A on the premise that a root gap of a desired length is ensured.

[0065] Also, as shown in FIG. 6(c), since the boundary between the bottom excavation bottom surface 19 and the bottom excavation inclined surface 18 of the bottom excavation tip 17B has a curvature 17b, for example, since the boundary between the bottom excavation bottom surface 19 and the bottom excavation inclined surface 18 is not a straight line, a margin can be provided in the processing of the bottom excavation tip 17B, and when continuously performing cutting processing from the bottom excavation inclined surface 18 to the bottom excavation bottom surface 19, by allowing the curvature 17b of those boundaries, variations can be given to the cutting processing method.

[0066] [Heterogeneous Diameter Column-Beam Joint Structure According to the Third Embodiment] Next, with reference to FIGS. 7 to 9, an example of a different-diameter column-beam joint structure according to the third embodiment will be described. Here, FIG. 7 is a longitudinal sectional view of an example of a different-diameter column-beam joint structure according to the third embodiment, FIG. 8 is an enlarged view of part VIII in FIG. 7 and is a view for explaining a new third welding joint form, and FIG. 9 is a view seen in the IX direction in FIG. 7.

[0067] The different-diameter column-beam joint structure 80C (80) shown in FIG. 7 is different from the different-diameter column-beam joint structures 80A and 80B having a continuous diaphragm 20A in that an inner diaphragm 20B with a 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-story column 50 is welded to the upper surface 21 of the inner diaphragm 20B.

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

[0069] At the side end 23 of the inner diaphragm 20B, the portion from the inner side to the middle position is a flat surface 24, and a groove-shaped groove 25 with a groove depth t9 is provided from the middle position to the outer side.

[0070] A backing plate 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 plate 30 forms a root gap.

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

[0072] In the welding joint form shown in the figure, since the backing plate 30 is inserted up to the middle position of the side end 23 of the inner diaphragm 20B, the formed gap G2 becomes as small as in the welding joint form shown in FIG. 3, and the root gap is sufficiently ensured by the plate thickness t8 of the inserted backing plate 30.

[0073] As shown in Fig. 9, in this welding joint form, since the panel core 10 is formed by welding four panel plates 11 to each other by full penetration welding, backing plates 38 for forming the panel core extending in the axial direction of the panel plate 11 are arranged at the inner corner portions of the adjacent panel plates 11. Therefore, a backing plate 30 is sandwiched between the flat surface 24 of the side end 23 of the inner diaphragm 20B corresponding to each panel plate 11 so as not to interfere with each backing plate 38 for forming the panel core at the inner corner portion of the panel core 10. Thus, even in the panel core 10 of the four-sided box provided with the backing plates 38 for forming the panel core at the inner corner portions, an equal root gap can be ensured over the entire circumference of the side end 23 of the inner diaphragm 20B.

[0074] [Reduced-diameter column-beam joint structure according to the fourth embodiment] Next, with reference to Fig. 10, an example of the reduced-diameter column-beam joint structure according to the fourth embodiment will be described. Here, Fig. 10 is a diagram for explaining a new fourth welding joint form forming the reduced-diameter column-beam joint structure according to the fourth embodiment.

[0075] The illustrated reduced-diameter column-beam joint structure 80D is the same as the reduced-diameter column-beam joint structure 80C 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 welding joint form (new fourth welding joint form) between 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 inner side to the middle position, and a counterbored groove 26 with a counterbored depth t11 in a trapezoidal shape in side view is provided from the middle position to the outer side.

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

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

[0079] In the welding joint form of the figure example, since the counterbore opening 26 is provided at an intermediate position of the side end 23 of the inner diaphragm 20B, the formed gap G3 becomes significantly smaller than the conventional gap G1, similar to the gap G2 in the welding joint form shown in FIG. 8. While the gap G3 becomes smaller, unlike the conventional partial penetration welding, the root gap is sufficiently ensured by the length t10 of the counterbore bottom surface 28 of the counterbore opening 26. Therefore, similar to the welding joint form shown in FIG. 8, it becomes a new welding form that is neither conventional full penetration welding nor partial penetration welding, and it is a welding joint form that ensures sufficient stress transmission between the column and the beam while reducing the welding amount as much as possible.

[0080] Also, different from the welding joint form shown in FIG. 8, since the backing plate 30 can be made unnecessary, the number of parts can be reduced and the manufacturability becomes even better.

[0081] [Calculation Method for Diaphragm Plate Thickness] When calculating the required plate thickness of the diaphragm (continuous diaphragm, inner diaphragm), in the calculation of the out-of-plane bending stiffness, yield out-of-plane bending stiffness, and full plastic out-of-plane bending strength of the diaphragm, the plate thickness of the yield line, the yield moment per unit length of the yield line, and the full plastic moment are designed based on the smallest value among the plate thickness of the diaphragm, the plate thickness of the panel plate, and the depth of the opening.

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

[0083]

Equation

[0084]

Number

[0085]

Number

[0086] Furthermore, other embodiments may be possible in which other components are combined with the configurations and the like described in the above embodiments, and the present invention is not limited to the configurations shown here. In this regard, it can be changed without departing from the gist of the present invention and can be appropriately determined according to the application form.

Explanation of Signs

[0087] 10: Panel core 11: Panel board 12: Upper end 13: Lower end 14: Inner surface 15: Flat surface 16: L-shaped groove 17, 17A, 17B: Pocket excavation 17a: Straight line 17b: Curvature 18: Pocket excavation inclined surface 19: Pocket excavation bottom surface 19A: Pocket excavation bottom surface (warped surface) 20: Diaphragm 20A: Through diaphragm (diaphragm) 20B: Inner diaphragm (diaphragm) 21: Upper surface 22: Lower surface 23: Side end 24: Flat surface 25: L-shaped groove 26: Pocket excavation 27: Pocket excavation inclined surface 28: Pocket excavation bottom surface 30: Backing plate 30A: Backing plate unit 35: Backing metal 38: Backing metal for panel core formation 40: Lower floor column (steel column) 41: Upper end 50: Upper floor column (steel column) 51: Lower end 60, 60A, 60B: Steel beam 61, 62: Side ends 70: Butt weld joint 75: Full penetration weld joint (an example of butt weld joint) 80, 80A, 80B, 80C, 80D: Different diameter column-beam joint structure G1, G2, G3: Space

Claims

1. A steel frame beam is welded to at least one of the panel plates of a panel core having a rectangular shape in plan view and comprising four panel plates, a lower floor column formed of a square steel pipe is welded to the lower end of the panel core, a continuous diaphragm having a rectangular shape in plan view is welded to the upper end of the panel core, and an upper floor column formed of a square steel pipe having a smaller cross-sectional dimension than the lower floor column is welded to the upper surface of the continuous diaphragm, which is a different-diameter column-beam joint structure, at the upper end of the panel plate, the middle part up to a certain position is a flat surface, and there is an L-shaped groove starting from the middle position and extending outward, a backing plate is sandwiched between the flat surface and the lower surface of the continuous diaphragm, and the plate thickness of the backing plate forms a root gap, a butting weld is provided in a space formed by the L-shaped groove, the root gap, and the lower surface of the continuous diaphragm, a backing plate unit in which four backing plates are arranged in a rectangular frame shape is sandwiched between the flat surface at the upper end of the panel core having a rectangular shape in plan view and the lower surface of the continuous diaphragm, and is characterized by a different-diameter column-beam joint structure.

2. The panel core is formed by welding four panel plates to each other or is formed of a square steel pipe, and is characterized by the different-diameter column-beam joint structure according to Claim 1.

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