JP2016160594A - Reinforcing structure for column-beam joint part panel zone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcing structure for a column-beam joint part panel zone that improves deformability of overall joint by having a beam member and the panel zone bear for certain a deformation in a column-beam joint part that uses H-section steel.SOLUTION: In a reinforcing structure for a column-beam joint part panel zone, a concrete block 4 is provided in a rectangular area surrounded by a panel frame 1A comprising a columnar flange 21 and a horizontal stiffener 5 that partition a panel zone 1 of a column-beam joint part 10, the concrete block restricting shear deformation of the panel zone 1 by regulating deformation of the columnar flange 21. The concrete block 4 is installed leaving a prescribed interval from the panel frame 1A. The panel zone 1 yields prior to a beam member, and shear deformation of the panel zone 1 is restricted by the concrete block 4.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a reinforcing structure for a column-beam joint panel zone in a steel structure using H-shaped steel for columns and beams.

  2. Description of the Related Art Conventionally, as a column-beam joint, an extremely thick and large H-section steel is used as a column member of a steel frame, and a structure that is welded to a beam using the H-section steel is known. In the moment frame that resists seismic force, the column, beam, and panel zone parts are greatly plastically deformed (energy absorption) without causing sudden strength deterioration due to fracture at the beam-column joint. It is a prerequisite. In general, when an H-shaped steel is used for a column, the beam flange is directly welded to the column flange by full penetration welding using a re-shaped groove.

In such a joint between a column and a beam using a general H-shaped steel, the shear strength of the panel zone may be insufficient because the column web is thinner than the column flange. In this case, since the panel zone is plasticized and excessive deformation occurs, local deformation (kink) is generated in the vicinity of the weld joint between the column flange 100 and the under-beam flange 101 as shown in FIG. K two-dot chain line region) occurs, which is one cause of breakage.
On the other hand, if a doubler plate is affixed to the panel zone and reinforced so that plasticization does not occur, the occurrence of kinks can be prevented, but the beam or column must bear the deformation that the panel zone does not bear. Therefore, there is a problem that the deformation performance as a whole structure is not improved. Therefore, Non-Patent Document 1 aims at a design in which the panel zone and the beam are both plasticized and share the deformation. Specifically, in Non-Patent Document 1, it is considered that the panel zone strength is defined and the panel zone proof strength is preferably 1.1 times or more and 1.67 times or less of the panel stress generated at the time of beam yielding.

  Moreover, in order to prevent the early destruction in a column flange, the nonpatent literature 1 prescribes | regulates a strict specification for a column beam junction part, and reduces the stress concentration of a joint part. Since these strict specification rules increase the cost of steel frame production, a simpler joint is required while ensuring fracture resistance.

FEMA355D (FEMA, 2000, State of the Art Report on Connection Performance, FEMA 355D, Report, prepared by the SAC Joint Venture, a partnership of the Structural Engineers Association of California (SEAOC), Applied Technology Council (ATC), and California Universities for Research in Earthquake Engineering (CUREe), for the Federal Emergency Management Agency, Washington, DC)

However, the conventional column beam joint panel zone reinforcement structure has the following problems.
That is, the plasticization of the panel zone may cause premature fracture due to local bending (kinks) of the column flange as described above. In addition, when the design is made to keep the panel zone elastic, the beam member bears all deformation, so that the deformation performance cannot be improved. Therefore, Non-Patent Document 1 proposes a design method that defines the upper and lower limits of the panel strength. However, when reinforcing with a doubler plate, it is ideal due to factors such as variations in the yield point of the doubler plate and beam members. It is not easy to achieve a strong proof stress balance (design in which the panel zone and the beam share plastic deformation), and there is room for improvement in that respect.

  The present invention has been made in view of the above-described problems. The deformation generated in the beam-column joint using H-shaped steel is surely shared between the beam member and the panel zone, so that the deformation performance of the entire joint can be improved. It is an object of the present invention to provide a reinforcing structure for a column beam joint panel zone which can be improved.

  In order to achieve the above object, the column-beam joint panel zone reinforcing structure according to the present invention is a column-beam joint panel zone reinforcing structure using H-shaped steel, and defines the column zone of the column-beam joint. A rectangular region surrounded by a panel frame composed of a column flange and a horizontal stiffener is provided with a block-like or cheek-like deformation restraining material that restrains the shear deformation of the panel zone by restricting the deformation of the column flange. The deformation restraining material is installed with a predetermined gap between at least the column flange of the panel frame, the panel zone yields prior to the beam member, and the panel is formed by the deformation restraining material. It is characterized by restraining the shear deformation of the zone.

In the present invention, when the panel zone undergoes shear deformation due to seismic force, the deformation restraining material is installed through at least the column flange and a predetermined gap in the panel frame (column flange and horizontal stiffener), Before the shear deformation of the panel zone becomes excessive, the deformation restraining material comes into contact with the panel frame and restrains the deformation of the panel zone. Thereby, since the panel yield strength exceeds the beam yield strength, the beam member is deformed from that state. That is, the beam member bears the deformation after the deformation of the panel zone is constrained.
In this way, it is possible to more reliably load the panel zone with an appropriate deformation than when reinforced with a doubler plate as in the prior art, and it is possible to more reliably share the deformation with the panel zone and the beam member. Moreover, the deformation performance as a column beam joint part can be improved.

  In the reinforcing structure of the column beam joint panel zone according to the present invention, it is preferable that the gap between the deformation restraining material and the panel frame is 1% or more and less than 2% of the beam.

  By setting the gap between the deformation restraining material and the panel frame in this way, the deformation restraining material can be brought into contact with the panel frame more reliably before the shear deformation of the panel zone becomes excessive, and the deformation of the panel zone is restrained. can do.

  Moreover, it is preferable that the reinforcement structure of the column beam junction panel zone which concerns on this invention has the said deformation | transformation restraint material arrange | positioned by the non-joining state with respect to the said panel zone.

  In this case, the panel zone can be deformed without being affected by the deformation restraining material before the panel frame contacts the deformation restraining material. Therefore, a column beam joint with high deformation performance can be realized.

  According to the reinforcing structure of the beam-column joint panel zone of the present invention, the deformation generated in the beam-beam joint using H-shaped steel is surely shared between the beam member and the panel zone, so that the deformation performance of the entire joint can be improved. Can be improved.

It is a perspective view which shows the structure of the column beam junction part by the 1st Embodiment of this invention. It is the AA arrow directional view shown in FIG. 1, Comprising: It is the side view which looked at the column beam junction part from the installation surface side. FIG. 3 is a cross-sectional view taken along the line B-B shown in FIG. It is a side view for demonstrating the operation | work of a column beam junction part. It is a perspective view which shows the structure of the column beam junction part by 2nd Embodiment. It is the side view which looked at the beam-column joint part shown in FIG. 5 from the installation surface side, Comprising: It is a figure corresponding to FIG. It is a figure for demonstrating the deformation | transformation sharing of the beam and junction panel by a comparative example, (a) is a figure which shows the simultaneous yield of a panel and a beam, (b) is a beam yielding, and a junction panel elastically deforms. The figure which shows a state, (c) is a figure which shows the state which a junction part panel yields and a beam elastically deforms. It is a figure for demonstrating the deformation | transformation sharing of the beam and junction panel by an Example. It is a figure which shows the state of the curved part deformation | transformation of the column flange by the panel zone deformation | transformation which arises in the conventional column beam welding joint part.

  Hereinafter, a reinforcing structure of a column beam joint panel zone according to an embodiment of the present invention will be described based on the drawings.

(First embodiment)
As shown in FIG. 1 and FIG. 2, the reinforcing structure of the column beam joint panel zone according to the present embodiment is as follows. In the panel zone 1 located at the column beam joint 10 of the column 2 and the beam 3 made of H-shaped steel, A block-like concrete block 4 (deformation restraint material) that restrains shear deformation of the panel zone 1 by restricting deformation of the column flange 21 on one side (hereinafter referred to as installation surface 1a) of the pillar web 22 of the pillar 2. It is the composition which arranged.

  The beam 3 is joined and protruded to each of the pair of column flanges 21 of the column 2 by welding. A pair of horizontal stiffeners 5 and 5 are integrally joined to both sides of the column web 22 of the column 2. The horizontal stiffener 5 is provided so as to be positioned on the extension line of the beam flange 31 of the beam 3, and a horizontal load is transmitted to the beam flange 31 between the beams 3 and 3 adjacent to each other with the column 2 interposed therebetween via the horizontal stiffener 5. It has become so.

Here, the panel zone 1 refers to a rectangular area surrounded by the pair of upper and lower horizontal stiffeners 5 and 5 and the pair of pillar flanges 21 and 21 in the pillar web 22. The column web 22 in the panel zone 1 is referred to as a junction panel 22A.
In addition, a frame-like portion including a pair of upper and lower horizontal stiffeners 5 and 5 and a pair of column flanges 21 and 21 that define the panel zone 1 is hereinafter referred to as a panel frame 1A.

  The concrete block 4 is a block that has a rectangular shape in a side view and is formed to have a certain thickness. The thickness direction of the concrete block 4 is perpendicular to the surface of the column web 22, and one installation surface 1 a of the panel zone 1 is disposed. Are arranged with a predetermined gap S between them and the panel frame 1A. The outer peripheral surfaces 4b, 4c, 4d, and 4e of the concrete block 4 are arranged so as to be parallel to the column flange 21 and the horizontal stiffener 5 that form the panel frame 1A, respectively. Note that the gap S may not be the same on the outer peripheral surfaces 4a, 4b, 4c, and 4d.

As shown in FIG. 3, the concrete block 4 has a plurality of stud bolts 41 projecting from the installation surface 1 a of the panel zone 1 by welding, and the stud bolts 41 are embedded in the concrete to place the concrete block 4. Manufactured. That is, the concrete block 4 is connected to the pillar web 22 by the four stud bolts 41. The back surface 4a of the concrete block 4 and the pillar web 22 are not joined.
In FIG. 3, a gap in the thickness direction of the column web 22 is formed between the surfaces of the back surface 4 a of the concrete block 4 and the column web 22. In the state, both sides 4 and 22 may be in surface contact.

  The gap S (separation dimension) between the concrete block 4 and the panel frame 1A is set to 1% or more and less than 2% of the beam (horizontal stiffeners 5, 5).

  According to the reinforcing structure of the column-beam joint panel zone described above, as shown in FIGS. 1 and 2, the panel zone 1 is designed so that the shear strength yields earlier than the beam member. When deformation due to seismic force occurs in the beam-column joint 10, yielding of the panel zone 1 occurs prior to deformation of the beam 3 and the column 2.

  When the panel zone 1 undergoes shear deformation due to seismic force, the concrete block 4 is installed via the panel frame 1A (the column flange 21 and the horizontal stiffener 5) and a predetermined gap S. When the deformation reaches 1 to 2% (ratio indicated by interlayer deformation angle / beam), the panel frame 1A becomes concrete in the panel frame 1A before the shear deformation of the panel zone 1 becomes excessive as shown in FIG. Contacting the block 4 restrains the shear deformation of the joint panel 22A (panel zone 1). If the rigidity of the concrete block 4 is designed to be sufficiently large, the apparent strength of the joint panel 22A of the beam-column joint 10 is increased and further deformation is constrained, and the panel strength is reduced to the beam strength. Therefore, the beam member is deformed from that state. That is, the beam member bears the deformation after the deformation of the panel zone 1 is restricted.

  As described above, it is possible to more reliably load the panel zone 1 with an appropriate deformation, and to more reliably share the deformation with the panel zone 1 and the beam member, as compared with the case of reinforcing with a conventional doubler plate. Therefore, the deformation performance as the column beam joint 10 can be enhanced.

  Further, in the present embodiment, the gap S between the concrete block 4 and the panel frame 1A is set to 1% or more and less than 2% of the beam, so that the concrete can be more reliably made before the shear deformation of the panel zone 1 becomes excessive. The block 4 can be brought into contact with the panel frame 1A, and deformation of the panel zone 1 can be restrained.

  Moreover, in this Embodiment, although the concrete block 4 is partially connected with the stud bolt 41, it has the structure arrange | positioned with respect to the panel zone 1 by the non-joining state. Thereby, before the panel frame 1 </ b> A contacts the concrete block 4, the panel zone 1 can be deformed without being affected by the concrete block 4. Therefore, the column beam joint 10 having high deformation performance can be realized.

  As described above, in the reinforcing structure of the column beam joint panel zone according to the present embodiment, the beam member and the panel zone 1 are surely shared with the beam member and the panel zone 1 by deforming the column beam joint 10 using H-shaped steel. The deformation performance of the entire beam joint 10 can be improved.

  Next, another embodiment of the reinforcing structure of the column beam joint panel zone according to the present invention will be described with reference to the accompanying drawings. However, the same or similar members and parts as those in the first embodiment are described below. The same reference numerals are used to omit the description, and a configuration different from the first embodiment will be described.

(Second Embodiment)
As shown in FIG. 5 and FIG. 6, the reinforcing structure of the column beam joint panel zone according to the second embodiment is the shear deformation of the panel zone 1 by restricting the deformation of the column flange 21 inside the panel frame 1A. The block-shaped steel plate block 6 (deformation restraint material) which restrains is provided.
The steel plate block 6 is a trapezoidal block formed from a steel plate, and is arranged with the trapezoidal bottom bottom steel plate 61 facing upward. The lower bottom steel plate 61 is connected to the upper horizontal stiffener 5 (5A) with a bolt 60 (not shown in FIG. 5) and is in surface contact with both, and the upper bottom steel plate 62 and the lower horizontal stiffener are provided. 5 (5B) and between the side plate of the steel plate block 6 and the column flange 21, a gap S is formed. The steel plate block 6 is provided with braces 63 that intersect with each other inside the trapezoidal outer frame.
The gap S between the steel plate block 6 and the lower horizontal stiffener 5 (5B), and the steel plate block side plate and the column flange 21 is not less than 1% of the beam (interval H between the horizontal stiffeners 5A and 5B) 2 It is set to less than%.
The steel plate block 6 may be rectangular instead of trapezoidal. Moreover, a clearance gap may be provided between the pillar webs 22 and it may join with a volt | bolt.

  Also in the case of the second embodiment, the panel zone 1 is designed so that the shear strength yields earlier than the beam member, and when the deformation due to the seismic force occurs in the column beam joint 10, The yielding of the panel zone 1 occurs prior to the deformation of the beam 3 and column 2.

  When the panel zone 1 undergoes shear deformation due to seismic force, the steel plate block 6 is placed between the panel frame 1A (here, the two column flanges 21 and 21, the lower horizontal stiffener 5B) and a predetermined gap S. When the panel zone 1 reaches a shear deformation of 1 to 2% (ratio indicated by the interlayer deformation angle / the height of the layer), the panel frame 1A before the shear deformation of the panel zone 1 becomes excessive. Contacts the steel plate block 6 in the panel frame 1A and restrains the shear deformation of the joint panel 22A. By designing the steel plate block 6 to have sufficiently high rigidity, the joint panel 22A of the beam-column joint 10 has an increased apparent strength and is restrained from being deformed further. Therefore, the beam member is deformed from that state. Therefore, as in the first embodiment described above, it is possible to load the panel zone 1 with an appropriate deformation, and it is possible to more reliably share the deformation between the panel zone 1 and the beam member. The deformation performance as the part 10 can be improved.

  Next, examples carried out for supporting the effect of the reinforcing structure of the column beam joint panel zone according to the above-described embodiment will be described below.

(Example)
In this example, the reinforcing structures of Comparative Examples 1 to 3 according to the conventional example and the reinforcing structures of Examples 1 to 3 according to the above-described embodiment were designed and their effects were confirmed.
The column beam members targeted in this design are a combination of column beams having a column cross section of H500 × 300 × 16 × 32 and a beam cross section of H600 × 200 × 9 × 16. The steel type is JIS SN490 (yield strength standard 325 MPa to 445 MPa). In structural design, it is usually assumed that the lower limit (325 MPa) of the yield point is used as the design strength. Based on the design concept of Non-Patent Document 1 (FEMA355D), the panel (panel zone) and the beam can share the deformation when the panel strength is in the range of 1.1 to 1.67 times the beam strength. Shall.
7 and 8 are diagrams for explaining the deformation sharing between the beam and the joint panel, showing the relationship between the interlayer deformation angle (rad) on the horizontal axis and the member deformation angle (rad) on the vertical axis. Yes.

First, a design method according to a comparative example will be described.
Table 1 shows the column, beam, and joint panel proof strength according to a comparative example based on a conventional method whose design policy is to balance the proof strength of the beam and the panel zone.

Comparative Example 1 is a case where the panel zone is reinforced from both sides with a doubler plate having a plate thickness of 16 mm, and the design strength of both the column beam becomes an actual yield point (325 MPa).
The panel yield strength is 1.28 times the beam yield strength, and as shown in FIG. 7 (a), the panel zone is also plasticized after the yielding of the beam. Thus, since the beam and the panel share the entire deformation by yielding the panel and the beam at the same time, the overall deformation performance is ensured.

In Comparative Example 2, the panel zone is reinforced from both sides with a doubler plate having a plate thickness of 16 mm, the yield point of the beam is the design strength (325 MPa), and the yield point of the column is the upper limit of specification (445 MPa).
The panel yield strength is 1.75 times the beam yield strength, and only the beam member is plasticized as shown in FIG. 7B. In Comparative Example 2, since only the beam bears, the deformation performance as a whole is lower than that of Comparative Example 1.

In Comparative Example 3, the panel zone is reinforced from both sides with a doubler plate having a plate thickness of 16 mm, the yield point of the beam is the upper limit of the standard (445 MPa), and the yield point of the column is the design strength (325 MPa).
Since the panel strength is below the beam strength, the panel zone yields in advance. Therefore, as shown in FIG. 7C, when the deformation progresses, the panel zone kinks breaks, and the deformation performance cannot be ensured.
As described above, even when the design is performed on the premise that the beam / panel proof stress of Comparative Example 1 is balanced, an ideal balance of proof stress may not be realized due to variations in yield points.

Next, in the embodiment, as shown in FIG. 8, the panel member is allowed to yield in advance (that is, the panel proof strength is lower than the beam proof strength). Therefore, the balance of proof stress when a combination of the above-mentioned column beams is reinforced from one side with a doubler plate having a thickness of 9 mm and when a deformation restraining material is installed will be examined.
Table 2 shows the column, beam, and joint panel yield strength according to the examples.

  In Example 1, when the panel zone is reinforced from one side with a doubler plate having a plate thickness of 9 mm and the design strength of both the column and beam is the actual yield point (325 MPa), the panel yield strength is 0.67 times the beam yield strength. Yes, the panel zone yields ahead. As shown in FIG. 8, the deformation of the panel zone is stopped at about 2% (reference symbol P shown in FIG. 8) by the deformation restraining material, and thereafter the beam bears the deformation, so that the deformation performance as a whole is ensured. be able to.

  Example 2 is a case where the panel zone is reinforced from one side with a 9 mm thick doubler plate, the yield point of the beam is the design strength (325 MPa), and the yield point of the column is the upper limit of specification (445 MPa). The yield strength is 0.91 times the beam strength, and the panel zone yields in advance. As shown in FIG. 8, the deformation of the panel zone is stopped at about 2% (reference symbol P shown in FIG. 8) by the deformation restraining material, and thereafter the beam bears the deformation, so that the deformation performance as a whole is ensured. be able to.

  Example 3 is a case where the panel zone is reinforced from one side with a 9 mm thick doubler plate, the yield point of the beam is the upper limit of specification (445 MPa), and the yield point of the column is the design strength (325 MPa). The yield strength is 0.49 times the beam strength, and the panel zone yields in advance. As shown in FIG. 8, the deformation of the panel zone is stopped at about 2% (reference symbol P shown in FIG. 8) by the deformation restraining material, and thereafter the beam bears the deformation, so that the deformation performance as a whole is ensured. be able to.

  Thus, in Examples 1-3, since the prior | preceding yield of a panel zone can be accept | permitted, even when the dispersion | variation in a yield point is considered, the deformation | transformation performance as a framework can be ensured.

  As mentioned above, although the embodiment of the reinforcing structure of the column beam joint panel zone according to the present invention has been described, the present invention is not limited to the above embodiment, and can be appropriately changed without departing from the scope of the present invention. is there.

  For example, the concrete block 4 according to the first embodiment is not limited to the concrete placement on site, but a column-shaped precast concrete deformation restraint material manufactured at a place different from the column beam joint 10 is connected by a bolt. You may make it connect with the web 22. FIG.

  Moreover, the concrete block 4 is not limited to the stud bolt 41 protruding from the pillar web 22 as in the present embodiment, and the adhesive is applied to the pillar web 22 (joint panel 22A) in the panel frame 1A. It may be connected via. In this case, the concrete block 4 may be bonded so as not to move from a predetermined position of the joint panel 22A, and it is preferable that the entire surface is not bonded integrally.

Further, the steel deformation restraining material is not limited to the shape of the steel plate block 6 according to the second embodiment, and a predetermined gap S between at least the column flange 21 in the panel frame 1A. As long as it is a shape installed with a gap, it does not have to be trapezoidal, and other shapes may be used.
For example, a cheek cane-like deformation restraining material without an outer frame may be adopted instead of a block shape having a quadrangular outer shape.
Furthermore, the deformation restraining material may be a combination of concrete and steel. For example, in order to increase the strength against the contact pressure with the panel frame, a rectangular concrete block whose outer peripheral surface is reinforced with a steel plate may be employed.

  Further, in the present embodiment, the deformation restraining material is disposed only on one side surface (installation surface 1a) of the panel zone 1, but the deformation restraining material is disposed on both side surfaces of the panel zone 1 (columnar web 22). It is also possible.

  Furthermore, in the present embodiment, the gap S between the deformation restraining material and the panel frame is set to 1% or more and less than 2% of the beam, but it is limited to this dimension. Absent.

  Moreover, it can set suitably also about structures, such as each dimension of the pillar 2, the beam 3, and the horizontal stiffener 5 which consist of H-section steel.

  In addition, it is possible to appropriately replace the components in the above-described embodiments with known components without departing from the spirit of the present invention.

1 Panel Zone 1A Panel Frame 2 Column 3 Beam 4 Concrete Block (Deformation Restraint Material)
5 Horizontal stiffener 6 Steel plate block (deformation restraint material)
10 Beam-to-column joint 21 Column flange 22 Column web 31 Beam flange 32 Beam web 41 Stud bolt S Gap H Gap spacing

Claims (3)

Reinforced structure of column beam joint panel zone using H-section steel,
A rectangular region surrounded by a panel frame composed of a column flange and a horizontal stiffener that defines a panel zone of a beam-column joint is a block shape that restricts shear deformation of the panel zone by restricting deformation of the column flange or A cheek cane-like deformation restraining material is provided,
The deformation restraining material is installed with a predetermined gap between at least the column flange of the panel frame,
The reinforcement structure of the column-beam joint panel zone, wherein the panel zone yields prior to the beam member and shear deformation of the panel zone is restrained by the deformation restraining material.   The reinforcing structure of a column beam joint panel zone according to claim 1, wherein a gap between the deformation restraining material and the panel frame is 1% or more and less than 2% of the beam.   The reinforcing structure of a column beam joint panel zone according to claim 1, wherein the deformation restraining material is arranged in a non-joined state with respect to the panel zone.

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