JP2013129959A - Column-beam joint structure of column with square hollow section and beam with h-shaped section - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outer diaphragm type column-beam joint structure which is lightweight and easy to transport.SOLUTION: There is provided a joint structure of a column-beam joint part coupling a column with a square hollow section and a flange part of a beam with an H-shaped section to each other through an outer diaphragm, which comprises four plate-like members covering four circumferential sides of the column. Each of the plate-like members is in a shape obtained by symmetrically cutting a rectangle having long sides in a flange width direction of the beam and side sides in a column axis direction such that a length in the column axis direction gradually decreases from an end of the long side or from nearby it to a 1/2 position and the length in the column axis direction at the 1/2 position is equal to or larger than the thickness of the flange part of the beam. A plate thickness of the plate-like member is equal to or larger than a plate thickness of a skin plate of the column, and the long side is joined at a position where a flange of the beam is fitted to be orthogonal to the column axis.

Description

  The present invention relates to a column beam connection structure in which a column having a square hollow cross section and a beam having an H shape cross section are bonded via an outer diaphragm.

  Generally, a joining element called a diaphragm is used for a column beam joint of a building steel structure in order to complement the joint strength. Various types of diaphragms are used for attachment of the diaphragm, and are roughly classified into an inner diaphragm type (FIG. 11), a through diaphragm type (FIG. 10), and an outer diaphragm type (FIG. 12) shown in Non-Patent Document 1.

  The inner diaphragm type is often joined by electroslag welding, and a very large heat input of several hundred thousand to several million J / cm acts on the welded part. The toughness of the steel deteriorates and a brittle fracture is likely to occur at the weld. This tendency is particularly remarkable in high-strength steel materials. Furthermore, in cold roll-formed square steel pipes and round steel pipes, electroslag welding cannot be applied due to the shape thereof, and therefore it is difficult to apply the inner diaphragm type.

  In the through diaphragm type, the column is once cut at the position where the diaphragm is disposed, and the divided columns are reassembled after the diaphragm welding.

  Since the outer diaphragm type can be applied to fillet welding between the diaphragm and the steel pipe column, there is no need to worry about deterioration of the toughness of the weld due to large heat input, and it can be easily applied to high-strength steel materials. Further, the outer diaphragm type has advantages such as less welding amount and processing amount than the through diaphragm type, and excellent workability when filling the steel pipe column with concrete.

  When welding an outer diaphragm to a steel pipe column at a construction site, in addition to welding between the diaphragm and the steel pipe column, there is also welding of the diaphragm and beam flange, or high-strength bolt connection, which increases the number of work processes at the construction site. .

  In addition, because the current outer diaphragm has a large protruding width from the column surface, when the outer diaphragm is installed at the factory and transported to the construction site, the number of columns loaded on the truck is limited by the outer diaphragm having a large protruding width. The transportation efficiency is poor.

  Therefore, an outer diaphragm type has been proposed in which four plate-like members are joined to the position where the flange portion of the beam is attached on the wall surface of the steel pipe column so that the projecting width dimension of the outer diaphragm is reduced (Non-Patent Document 2). .

  Further, Patent Document 1 discloses an outer diaphragm in which a square sleeve obtained by bending a flat steel with a constant width is attached to a steel pipe column. By adjusting the width of the flat steel, the same steel pipe column can have a “beam seismic”. It is stated that different beams can be attached.

JP 2006-002351 A

Architectural Institute of Japan Steel Structure Joint Design Guidelines Chapter 4 Beam-Column Joint, 2006, 3 Experimental study of square steel tube column and H-shaped beam joints using a four-plate diaphragm, Abstracts from the Architectural Institute of Japan C, Structure II 1992, 1555-1556, 1992, 8

  However, in the case of the outer diaphragm type described in Non-Patent Document 2, the length in the column axis direction of the plate-like member used as the diaphragm is the same as the plate thickness and cannot be made large. For this reason, when different beams are attached to the same steel pipe column, it is necessary to install an outer diaphragm for each beam flange position, which increases the construction cost.

  The outer diaphragm type described in Patent Document 1 has a drawback in that the strength of the outer diaphragm against the tensile force in the outer direction of the steel pipe column surface, which is transmitted from the beam flange to the outer diaphragm when the band width is increased, is reduced.

  Therefore, the present invention provides a column beam joint portion of an outer diaphragm type that connects a column having a square hollow section and a beam having an H shape section, which is small in weight and easy to carry, with a small projection width of the outer diaphragm from the column surface. The purpose is to provide a structure.

The object of the present invention can be achieved by the following means.
1. It is a joining structure of a column beam joint that connects a column having a square hollow section and a flange portion of a beam having an H shape section via an outer diaphragm, and the outer diaphragm has four plate-like shapes covering the four circumferences of the column. The plate-like member has a rectangular shape having a long side in the flange width direction of the beam and a short side in the column axis direction. The plate thickness of the plate-like member is such that the length gradually decreases and the length in the column axis direction at the 1/2 position is notched symmetrically so as to be equal to or greater than the thickness of the flange portion of the beam. A square hollow section column, wherein the column is equal to or greater than the thickness of the skin plate of the column, and the long side is joined to the column at a position where the flange of the beam is attached to the column. And beam-to-column connection structure of H-shaped cross section beam.
2. It is a joining structure of a column beam joint that connects a column having a square hollow section and a flange portion of a beam having an H shape section via an outer diaphragm, and the outer diaphragm has four plate-like shapes covering the four circumferences of the column. The plate-shaped member has a rectangular shape in which the flange width direction of the beam is the long side and the column axis direction is the short side, and extends from the end of the long side or the vicinity thereof to the 1/2 position in the column axis direction. The length in the column axis direction at the 1/2 position is equal to or greater than the thickness of the flange portion of the beam, and a portion with a certain length in the column axis direction is formed on the left and right of the 1/2 position. The plate-like member has a shape that is cut symmetrically so that it has a plate thickness that is equal to or greater than the plate thickness of the skin plate of the column, and the long side is at a position where the flange of the beam is attached to the column. Square hollow section characterized by being joined so as to be orthogonal to the column axis Beam structure for joining columns and H-shaped cross-section beam.
3. 3. The rectangular hollow cross-section column and the H-shaped cross-section beam according to 1 or 2, wherein the plate-like member has a portion having a certain length in the column axis direction at both ends on the long side. Column beam connection structure.
4). Any of the lengths in the column axis direction of the plate-like member, wherein the minimum length in the range where the flange portion of the beam is attached is 90% or more of the maximum length. The column beam connection structure of the square hollow section column and H section beam described in one.

  According to the present invention, since the protruding portion of the outer diaphragm from the column is small and a beam having a different beam length can be attached to the column, the outer diaphragm type rectangular hollow section column and the H-shaped section beam having excellent transport efficiency can be obtained. A column beam connection structure is obtained, which is extremely useful in industry.

The figure explaining the column beam junction structure (in the case of factory welding) concerning one example of the present invention. The figure explaining the column beam junction structure (in the case of factory welding) concerning other examples of the present invention. The figure explaining the analysis model used for the test which analyzes the shape of the plate-shaped member which comprises the outer diaphragm of the column beam connection structure concerning this invention, (a) is a top view, (b) shows a side view. The figure explaining the shape of the plate-shaped member used for the analysis model of FIG. The figure which shows the influence which the notch part of a plate-shaped member exerts on the mechanical characteristics of the column beam connection structure of the analysis model of FIGS. The figure which shows the example of a shape ((a)-(d)) of the plate-shaped member which comprises the outer diaphragm of the column beam junction structure which concerns on this invention. The figure which shows the example of a shape ((a)-(d)) of the plate-shaped member which comprises the outer diaphragm of the column beam junction structure which concerns on this invention. The figure which shows the example of a shape ((a)-(d)) of the plate-shaped member which comprises the outer diaphragm of the column beam junction structure which concerns on this invention. The figure which applied the column beam junction structure concerning one example of the present invention to the middle pillar. An example of a conventional diaphragm with a column-beam joint structure. An example of an inner diaphragm of a conventional column-beam joint structure. An example of a conventional outer diaphragm with a column-beam joint structure.

  The present invention provides an outer diaphragm type column beam joint in which the outer diaphragm is a plate-like member, and the yield strength of the beam-beam joint exceeds the maximum strength of the beam flange. The shape is such that different beams can be attached.

  FIG. 1 is a schematic diagram showing the structure of an outer diaphragm type column beam joint according to an embodiment of the present invention. In the figure, 1 is a steel column with a square hollow section, 1a is a skin plate of a steel column 1, and 2 is H. A steel beam having a cross section (sometimes referred to as a beam bracket), 2a is a beam flange of the steel beam 2, 2b is a beam web of the steel beam 2, 3 is a groove for welding the beam flange 2a and the outer diaphragm 10, 4 Is a scallop, 5 is a skin plate (sometimes referred to as a column surface) 1a of the steel column 1 and a fillet welded portion of the outer diaphragm 10, 6 is a butt welded portion of the outer diaphragm 10 and the beam flange 2a, and 10 is a plate-like member An outer diaphragm consisting of 11 is shown.

  The outer diaphragm 10 is composed of four plate-like members 11 that cover the four circumferences of the steel column 1. The plate-like member 11 has a shape in which a notch is provided in a rectangle having the long side in the width direction of the beam flange 2a of the steel beam 2 and the short side in the column axis direction. The mechanical characteristics of the beam-column joint when the notched portion is provided in the plate member 11 to form the outer diaphragm 10 will be described below.

In the beam-column joint portion, when the yield strength of the beam-column joint portion is P _y and the maximum strength of the beam flange 2a is P _{max , the} beam breaks, and therefore it is necessary to satisfy the following formula (1).

The yield strength P _y of the beam-column joint is obtained by Expression 2 obtained from the numerical analysis result considering the elasto-plasticity in which the parameters shown in Table 1 are changed in the analysis model shown in FIG. 3A is a plan view of the analysis model, and FIG. 3B is a side view. The analysis model is an outer diaphragm reinforcing joint that models a column-tension beam flange joint in a box-shaped cross-section column-H-shaped cross-section beam joint having a plate-shaped member as an outer diaphragm, and a plate-like member 11 on the column surface 1a. And the beam flange 2a is attached.

  Assuming a middle column when the horizontal load at the time of earthquake acts on the building, in order to reflect in the analysis that the outer diaphragm cross section in the column central axis orthogonal to the horizontal load is in the state of stress, the corresponding plate member 11 50 mm slits are provided (in FIG. 3, the beam side portion of the plate-like member divided by the 50 mm slits is used as the support member 9). FIG. 4 shows the shape of the plate-like member 11 in the analysis model shown in FIG. In these drawings, the same components as those in FIG.

Expression (2) is an expression expressed using the yield strength P _y obtained from a total of 21 analysis models and the five parameters of the _joint, and multiple regression using the yield strength P _{y_FEM} of each analysis model and those parameters. Derived through analysis. In Equation 2, B _f is the range of changing the width of the pillar-axis direction of the plate member 11, t _p is the cylindrical surface thickness, t _s is the thickness of the struts of the plate-like member 11 in the analysis model, h _s is the distance from the back of the cylindrical surface 1a in the analysis model to the flange corresponding members 2a, _p σ _y is the yield strength of the pillars skin plate 1a, the _d sigma _y indicates the yield strength of the outer diaphragm (plate member 11). In addition, the yield strength _{Py_FEM} of each analysis model was a point at which the stiffness becomes 1/3 of the initial stiffness in the load-displacement relationship.

For yield strength P _y in the analysis model, by varying the width t _f pillar axis direction of the plate member 11 (also referred to as a cylindrical axis direction) _{(corresponding} to the flange thickness t _f), gives the yield strength P _y The impact was analyzed.

Plate range B _f to vary the width of the pillar axis of the member 11 and the width B _f of the beam flanges 2a, outside the 45 ° of across the hypotenuse of inclination pillar axis direction of width t _{s (t s} switches the same value as the thickness of the support member 9 of the plate-like member 11 in the analysis model (FIG. 4).

No. in Table 1 5 model as a reference of varying Delta] t _s in Figure 4 to 2.5~9mm (5~18mm on both sides).

The analysis results are shown in FIG. According widths Delta] t _s notching the pillar axis direction of the plate-like member 11 _{increases, P y / P y0 (P} y0 is the yield strength of the No.5) will be decreased, Delta] t _s is 7.5% ( P _y from the time of more than 15%) on both sides is reduced significantly.

From FIG. 5, the width Δts cut out in the column axis direction in the region of the long side of the plate-like member 11 and the width B _f (the same width as the beam flange width B _f ) has a great influence on the mechanical properties of the beam-column joint. There is no range, and at least 10% of the original width ts can be cut out.

  Therefore, in the present invention, a notch portion is provided to reduce the weight of the plate-like member 11 and facilitate handling at the construction site. The shape and size of the notch provided in the plate-like member 11 are appropriately set using the method described above so as not to impair the mechanical properties of the beam-column joint.

  The shape of the cutout portion is such that the shape of the plate-like member after the cutout is from the end of the long side of the plate-like member 11 or the vicinity thereof to ½ position so that the processing to the plate-like member 11 is easy. The length in the column axis direction gradually decreases, and the shape (ribbon shape) is symmetric with respect to the half position of the long side of the plate-like member 11 (FIGS. 6A to 6D and FIG. a) to (d)), the length in the column axis direction gradually decreases from the end of the long side of the plate-like member 11 or the vicinity thereof to the vicinity of the 1/2 position, and in the column axis direction to the left and right of the 1/2 position. It is preferable to use a symmetrical shape (dogbone shape) having a portion of a certain length (FIGS. 7A to 7D).

  From the analysis model result, the minimum length within the range where the beam flange 2a of the beam 2 is attached on the long side of the length in the column axis direction of the plate-like member 11 is the maximum length on the long side of the plate-like member 11. If it is 90% or more, the mechanical properties will not be greatly affected. However, in any plate-like member 11 shown in FIGS. 6 to 8, the length in the column axis direction at the half position of the long side of the plate-like member 11 is set so that the beam flange 2 a can be welded. It shall be more than the thickness of the flange part.

  Further, the plate thickness (wall thickness) of the plate-like member 11 is set to be equal to or greater than the plate thickness of the skin plate 1a in order to reinforce the skin plate 1a of the steel column 1 and ensure the rigidity as the outer diaphragm.

  The length of the plate member 11 in the column axis direction is appropriately set so that the plate member 11 can be attached even if the “seismic” of the steel beam 2 changes. When the steel column 1 is an outer column, a middle column, and an inner column, a plurality of steel beams 2 having different “seis” are attached (FIG. 9).

  In the beam-column joint according to the present invention, the plate-like member 11 is joined to the skin plate 1a at a position where the flange 2a of the beam 2 is attached to the steel column 1 so that its long side is orthogonal to the column axis of the steel column 1. Has been.

  By fixing the plate-like member 11 to the beam flange 2a and the steel column 1, the joint end portion of the beam flange 2a is reinforced. Further, since the plate-like member 11 is wide at the column corner, the stress concentration at the column corner can be relaxed, the stress from the steel beam 2 can be smoothly flowed into the steel column 1, and The length of the beam 2 of the plate-like member 11 in the material axis direction can be shortened.

  In the construction, the steel column 1 and the plate-like member 11 are welded by fillet welding, and then the beam flange 2a of the steel beam 2 is welded to the plate-like member 11 by butt welding. In order to make the butt weld 6 and fillet weld 5 free of welding defects, butt welding is performed by providing a groove 3 on the beam flange 2a, and fillet welding is performed on the skin plate 1a side of the long side of the plate-like member 11. Chamfer.

  The “bending” acting on the beam-column joint is transmitted from the upper and lower flanges 2a, 2a to the steel column 1 via the plate member 11, and the shearing force is transmitted to the steel column 1 via the beam web 2b. The beam web 2b is fixed to the skin plate 1a of the steel column 1 by fillet welding.

  FIG. 1 shows the case of a column-beam joint structure by factory welding. FIG. 2 shows the case of a column-beam joint structure by field welding. 2, 7 indicates a gusset plate, 8 indicates a bolt, and the same components as those in FIG.

  In the construction by field welding, the gusset plate 7 is attached to the steel column 1 by welding in advance, the steel beam 2 is suspended between the steel columns 1 and 1, and the beam web 2b is temporarily fixed to the gusset plate 7 with bolts 8. The beam flange 2a is joined to the plate-like member 11 welded to the steel column 1 by butt welding, and after the welding is finished, the bolt 8 is finally tightened to join the steel column 1 and the steel beam 2.

  In addition, in the column beam junction part which concerns on this invention, the structure method in particular of the outer diaphragm 10 is not prescribed | regulated. The plate-like member 11 is joined to each skin plate 1a of the steel pipe column 1, and the ends of the four plate-like members 11 that are joined are welded to cover the four circumferences of the steel pipe column 1 or may be formed as a square sleeve in advance. good.

  The outer diaphragm 10 may be divided into a plurality of parts. In that case, one divided outer diaphragm 10 (plate-like member 11) is connected to one of the adjacent outer diaphragms 10 (plate-like member 11).

DESCRIPTION OF SYMBOLS 1 Steel column 1a Skin plate 2 Steel beam 2a Beam flange 2b Beam web 3 Groove 4 Scallop 5 Fillet weld part 6 Butt weld part 7 Gusset plate 8 Bolt 9 Base material 10 Outer diaphragm 11, 11a Plate-shaped member

Claims (4)

  It is a joining structure of a column beam joint part in which a column having a square hollow section and a flange part of a beam having an H shape section are connected via an outer diaphragm, and the outer diaphragm has four plate shapes covering the four circumferences of the pillar. The plate-like member has a rectangular shape having a long side in the flange width direction of the beam and a short side in the column axis direction. The plate thickness of the plate-like member is such that the length gradually decreases and the length in the column axis direction at the 1/2 position is notched symmetrically so as to be equal to or greater than the thickness of the flange portion of the beam. A square hollow section column, wherein the column is equal to or greater than the thickness of the skin plate of the column, and the long side is joined to the column at a position where the flange of the beam is attached to the column. And beam-to-column connection structure of H-shaped cross section beam.   It is a joining structure of a column beam joint part in which a column having a square hollow section and a flange part of a beam having an H shape section are connected via an outer diaphragm, and the outer diaphragm has four plate shapes covering the four circumferences of the pillar. The plate-shaped member has a rectangular shape in which the flange width direction of the beam is the long side and the column axis direction is the short side, and extends from the end of the long side or the vicinity thereof to the 1/2 position in the column axis direction. The length in the column axis direction at the 1/2 position is equal to or greater than the thickness of the flange portion of the beam, and a portion with a certain length in the column axis direction is formed on the left and right of the 1/2 position. The plate-like member has a shape that is cut symmetrically so that it has a plate thickness that is equal to or greater than the plate thickness of the skin plate of the column, and the long side is at a position where the flange of the beam is attached to the column. Square hollow section characterized by being joined so as to be orthogonal to the column axis Beam structure for joining columns and H-shaped cross-section beam.   3. The rectangular hollow cross-section column and the H shape according to claim 1 or 2, wherein the plate-like member has a portion having a certain length in the column axis direction at a portion which becomes both ends on the long side. Column beam connection structure of cross-section beams.   4. The length of the plate-like member in the column axis direction is such that the minimum length within a range where the flange portion of the beam is attached is 90% or more of the maximum length. A column beam joint structure of the square hollow section column and the H section beam according to any one of the above.