Column-beam structure

Abstract

To suppress damage of a column head part of a lower side wooden column and a column base part of an upper side wooden column during earthquakes in a column-beam frame in which a through steel beam is arranged between the lower side wooden column and the upper side wooden column.SOLUTION: A column-beam frame 10 includes: a through steel beam 40 having a lower wooden column 20L, an upper wooden column 20U arranged on the upper side of the lower wooden column 20L, a joint part 40A arranged between the lower wooden column 20L and the upper wooden column 20U, and a beam part 40B extending from the joint part 40A; a pair of lower bearing plates 50 extending downward from the joint part 40A, passing through a column head part 20L1 of the lower wooden column 20L, and joined to the column head part 20L1 in a state of being held from both sides in the material axial direction of the steel beam 40; a pair of upper bearing plates 60 which extend upward from the joint part 40A, passing through a column base part 20U1 of the upper wooden column 20U, and are joined to the column base part 20U1 in a state of being held from both sides in a material axial direction of the steel beam 40; and a damping part 80 provided on the beam part 40B.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a beam-column structure. [Background technology]

[0002] BACKGROUND ART A column-beam joint structure is known in which a steel beam (through steel beam) is disposed between a lower wooden column and an upper wooden column (see, for example, Patent Documents 1 to 3).

[0003] Also, a steel beam is known that has a shear yielding portion provided at the center in the axial direction of the beam (see, for example, Patent Document 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-218464 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-109150 [Patent Document 3] Japanese Patent Application Laid-Open No. 2017-133278 [Patent Document 4] Japanese Patent Application Publication No. 9-105244 Summary of the Invention [Problem to be solved by the invention]

[0005] The technologies disclosed in Patent Documents 1 to 3 have room for improvement in that the capital parts of the lower wooden columns and the base parts of the upper wooden columns connected to the through steel beams may be damaged during an earthquake.

[0006] Taking the above facts into consideration, the present invention aims to suppress damage to the capital part of the lower wooden column and the base part of the upper wooden column during an earthquake in a column-beam structure in which a through steel beam is arranged between a lower wooden column and an upper wooden column. [Means for solving the problem]

[0007] According to the first aspect The beam-column structure includes a through steel beam having a lower wooden column, an upper wooden column arranged above the lower wooden column, a joint section arranged between the lower wooden column and the upper wooden column, and a beam section extending from the joint section, a pair of lower support plates extending downward from the joint section and joined to the column head of the lower wooden column in a state where the column head is sandwiched from both sides in the material axis direction of the through steel beam, and a pair of upper support plates extending upward from the joint section and joined to the column base of the upper wooden column in a state where the column base is sandwiched from both sides in the material axis direction of the through steel beam. and a vibration damping portion provided on the beam portion.

[0008] First aspect According to the beam-column structure, the through steel beam has a joint portion and a beam portion extending from the joint portion. The joint portion is disposed between the lower wooden column and the upper wooden column.

[0009] Here, a pair of lower support plates extend downward from the joints of the through steel beams and are joined to the column capitals of the lower wooden columns while being sandwiched between the column capitals of the through steel beams from both sides in the material axis direction. Also, a pair of upper support plates extend upward from the joints of the through steel beams and are joined to the column bases of the upper wooden columns while being sandwiched between the column bases of the upper wooden columns from both sides in the material axis direction.

[0010] This allows the joints between the through steel beam and the capital and base of the lower and upper wooden columns to be semi-rigid. As a result, bending moments can be transmitted between the joints of the through steel beam and the capital and base of the lower and upper wooden columns. This improves the seismic performance of the beam-column structure.

[0011] In addition, vibration-damping sections are provided on the beam sections of the through steel beams. These vibration-damping sections absorb seismic forces, reducing the seismic forces acting on the capitals of the lower wooden columns and the bases of the upper wooden columns. As a result, damage to the capitals of the lower wooden columns and the bases of the upper wooden columns during an earthquake is suppressed. This further improves the seismic performance of the beam-column structure.

[0012] According to the second aspect The column-beam frame is According to the first aspect The column-beam frame is provided with covering concrete that covers the upper bearing plate and the lower bearing plate, respectively.

[0013] Second aspect According to the beam-column structure described above, by covering the upper and lower bearing plates with covering concrete, the fire resistance of the lower and upper wooden columns can be improved while also increasing the fixation of the lower and upper wooden columns to the joints of the through steel beams, thereby further improving the seismic performance of the beam-column structure.

[0014] According to the third aspect The column-beam frame is First aspect or According to the second aspect In a beam-column structure, the vibration-damping portion is provided at the center of the beam portion in the material axis direction.

[0015] Third aspect In the beam-column structure described above, a vibration-damping section is provided at the center of the beam section of the through steel beam in the material axis direction, where shear force predominates during an earthquake. This reduces the effect of bending moment on the vibration-damping section, making it easier to shear-yield the vibration-damping section at the specified timing. This makes it easier to design the vibration-damping section. [Effects of the Invention]

[0016] As described above, according to the present invention, in a column-beam structure in which a through steel beam is arranged between a lower wooden column and an upper wooden column, damage to the capital part of the lower wooden column and the base part of the upper wooden column can be suppressed during an earthquake. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is an elevation view showing a column-beam frame according to one embodiment. [Figure 2] 2 is an enlarged elevation view showing the joints between the lower and upper wooden columns and the through steel beams shown in FIG. 1. FIG. [Figure 3] 3 is an exploded elevational view showing the joints between the lower and upper wooden columns and the through steel beams shown in FIG. 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, a beam-column structure according to one embodiment will be described with reference to the drawings.

[0019] (Column-beam frame) 1, the beam-column structure 10 according to this embodiment includes a lower wooden column 20L, an upper wooden column 20U, and a through steel beam 40. Note that the arrow X shown in each drawing indicates the material axis direction of the through steel beam 40 (hereinafter also referred to as the "beam axis direction").

[0020] (Lower wooden pillar, upper wooden pillar) The lower wooden columns 20L are arranged at intervals in the material axis direction of the through steel beams 40. Upper wooden columns 20U are arranged above these lower wooden columns 20L. The lower wooden columns 20L and upper wooden columns 20U, which are adjacent in the vertical direction, are joined via joints 40A of the through steel beams 40, which will be described later.

[0021] The lower wooden post 20L and the upper wooden post 20U have the same configuration. Therefore, the following will describe the configuration of the lower wooden post 20L, and will omit a description of the configuration of the upper wooden post 20U as appropriate.

[0022] The lower wooden column 20L is formed in a rectangular column shape. The lower wooden column 20L has a fire-resistant structure. The lower wooden column 20L has a wood core 22 that supports a load (vertical load) and a fire-resistant covering 24 that provides a fire-resistant covering to the wood core 22.

[0023] (woody heart) The wood core 22 is made of wood material such as laminated lumber. The wood core 22 extends in the axial direction of the lower wooden column 20L and has a rectangular cross-sectional shape. The wood core 22 is formed to be able to support the load (long-term load and short-term load) borne by the lower wooden column 20L.

[0024] (Fire-resistant coating) The fire-resistant coating 24 has a fire-retardant layer 26 that covers the wood core 22, and a substitute fire layer 28 that covers the fire-retardant layer 26. The capital part 20L1 of the lower wooden column 20L is not provided with the fire-resistant coating 24, and the wood core 22 is fire-resistant coated with coating concrete 54, which will be described later. Similarly, the base part 20U1 of the upper wooden column 20U is not provided with the fire-resistant coating 24, and the wood core 22 is fire-resistant coated with coating concrete 64, which will be described later.

[0025] (fire-stop layer) The fire-retardant layer 26 is formed in a cylindrical shape surrounding the woody core 22, and covers the entire side surface of the woody core 22. This fire-retardant layer 26 stops the combustion of the substitute fire layer 28 in the event of a fire (spontaneous extinguishing), and is a layer that suppresses the combustion of the woody core 22.

[0026] The fire-retardant layer 26 is a high-heat-capacity layer (heat-capacity type) with a larger heat capacity than the wood core 22. This fire-retardant layer 26 has hardened cement bodies and wood materials arranged alternately around the circumference of the wood core 22. The hardened cement bodies and wood materials are arranged along the material axis direction of the lower wooden column 20L and are joined to the side of the wood core 22 with an adhesive or the like.

[0027] The hardened cement body is formed from, for example, hardened mortar, grout, or concrete, and has a larger heat capacity than wood material. By arranging this hardened cement body and wood material alternately, the heat capacity of the entire fire-retardant layer 26 becomes larger than the heat capacity of the wood core 22 and the substitute fire layer 28. Note that in the fire-retardant layer 26, gypsum and wood material can also be arranged alternately instead of the hardened cement body.

[0028] (stolen layer) A wooden sub-combustible layer 28 is provided on the outside of the fire-retardant layer 26. The sub-combustible layer 28 is formed in a cylindrical shape that surrounds the fire-retardant layer 26 and covers the entire side surface of the fire-retardant layer 26. This sub-combustible layer 28 burns in the event of a fire and forms a carbonized layer (thermal insulating layer), thereby preventing the heat of the fire from penetrating into the woody core 22.

[0029] The sub-combustible layer 28 is formed from a wooden material such as laminated lumber, and is joined to the side of the fire-stopping layer 26 with an adhesive or the like. The thickness (layer thickness) of the sub-combustible layer 28 is set appropriately according to the required fire resistance performance (fire resistance time) required for the lower wooden column 20L, and the burning speed and heat-shielding performance of the sub-combustible layer 28.

[0030] (Through steel beam) The through steel beam 40 is formed of an H-shaped steel. The through steel beam 40 has a pair of upper and lower flanges 42 and 44 that face each other in the vertical direction, and a web 46 that connects the upper and lower flanges 42 and 44.

[0031] Furthermore, the through steel beam 40 has a joint portion 40A and beam portions 40B extending on both sides from the joint portion 40A. The through steel beam 40 is fire-resistant coated with a fire-resistant coating material (not shown) such as sprayed rock wool.

[0032] (joint) 1, the joint 40A is a joint between the lower wooden column 20L and the upper wooden column 20U in the through steel beam 40, and is located between the lower wooden column 20L and the upper wooden column 20U. A pair of lower support plates 50 is provided on the lower flange 44 of the joint 40A.

[0033] The pair of lower support plates 50 are made of steel plates or the like and face each other in the beam axial direction (the direction of arrow X). The pair of lower support plates 50 also extend downward from the lower surface of the lower flange 44 and are joined to the column capital portion 20L1 of the lower wooden column 20L.

[0034] 2 and 3, the pair of lower support plates 50 are arranged along the side surface 22S of the wood core 22 of the capital part 20L1 in the beam axial direction, sandwiching the wood core 22 from both sides in the beam axial direction. The pair of lower support plates 50 also span from one end side to the other end side in the width direction of the side surface 22S of the wood core 22.

[0035] Each lower support plate 50 has a plurality of through holes 52 formed therein, penetrating the lower support plate 50 in the thickness direction. The wood core 22 of the capital column 20L1 has a plurality of through holes 72 formed therein, penetrating the wood core 22 in the beam axial direction. By tightening nuts 74 on both ends of through-bolts 70 inserted into these through holes 52, 72, the wood core 22 of the capital column 20L1 is clamped from both sides in the beam axial direction by the pair of lower support plates 50. In this state, the capital column 20L1 of the lower wooden column 20L is joined (semi-rigidly) to the joint 40A.

[0036] The pair of lower support plates 50 are covered with covering concrete 54. The covering concrete 54 is made of, for example, reinforced concrete. This covering concrete 54 surrounds the wood core 22 at the column capital 20L1 of the lower wooden column 20L, and covers all four side surfaces 22S of the wood core 22.

[0037] The covering concrete 54 provides a fire-resistant coating to the wood core 22 and the pair of lower support plates 50. The covering concrete 54 also increases the degree of fixation of the pair of lower support plates 50 to the wood core 22.

[0038] The outer shape of the covering concrete 54 is approximately the same as the outer shape of the fire-resistant covering portion 24 of the lower wooden column 20L.

[0039] 1, a pair of upper support plates 60 is provided on the upper flange 42 of the joint portion 40A. The pair of upper support plates 60 is formed from steel plates or the like and faces each other in the beam axial direction (arrow X direction). The pair of upper support plates 60 also extend upward from the top surface of the upper flange 42 and are joined to the column base 20U1 of the upper wooden column 20U.

[0040] 2 and 3, the pair of upper support plates 60 are arranged along the side surface 22S of the wood core 22 of the column base 20U1 in the beam axial direction, sandwiching the wood core 22 from both sides in the beam axial direction. The pair of upper support plates 60 also span from one end side to the other end side in the width direction of the side surface 22S of the wood core 22.

[0041] Each upper support plate 60 has a plurality of through holes 62 formed therein that penetrate the upper support plate 60 in the thickness direction. Furthermore, the wood core 22 of the base 20U1 has a plurality of through holes 72 formed therein that penetrate the wood core 22 in the beam axial direction. By tightening nuts 74 onto both ends of through bolts 70 inserted into these through holes 62, 72, the pair of upper support plates 60 are joined to the wood core 22 of the base 20U1.

[0042] The pair of upper support plates 60 are covered with covering concrete 64. The covering concrete 64 is made of, for example, reinforced concrete. This covering concrete 64 surrounds the wood core 22 at the base 20U1 of the upper wooden column 20U, and covers all four side surfaces 22S of the wood core 22. The covering concrete 64 provides a fire-resistant coating to the wood core 22 and the pair of upper support plates 60. The covering concrete 64 also increases the degree of fixation of the pair of upper support plates 60 to the wood core 22.

[0043] The outer shape of the covering concrete 64 is approximately the same as the outer shape of the fire-resistant covering portion 24 of the upper wooden column 20U.

[0044] The joint 40A is provided with a pair of stiffeners 48 that reinforce the joint 40A. The pair of stiffeners 48 are formed from steel plates or the like, and are provided on both sides of the web 46 of the joint 40A. The pair of stiffeners 48 extend in the beam configuration direction of the through steel beam 40, and are arranged with a gap in the beam axial direction.

[0045] Each stiffener 48 is disposed across the upper flange 42 and the lower flange 44 so as to be continuous with the lower support plate 50 and the upper support plate 60. Each stiffener 48 is joined to the upper flange 42, the lower flange 44, and the web 46, respectively, by welding or the like. Stiffeners 48 may be provided as needed, and may be omitted as appropriate.

[0046] (beam) As shown in Fig. 1, the beam section 40B is disposed between the joint sections 40A on both sides and connects these joint sections 40A. A vibration-damping section 80 that absorbs seismic force (earthquake energy) is provided in the center of the beam section 40B in the beam axial direction. The vibration-damping section 80 is, for example, a steel damper.

[0047] Specifically, in the vibration-damping section 80 of the through steel beam 40, the web 46, the lower flange 44, and the upper flange 42 are formed of low-yield-point steel. On the other hand, other portions of the through steel beam 40 are formed of ordinary steel, for example. This makes the vibration-damping section 80 more susceptible to yielding (shear yielding) than other portions of the through steel beam 40.

[0048] In addition, in this embodiment, the yield strength (shear yield strength) of the vibration-damping section 80 is set so that, during an earthquake, the vibration-damping section 80 yields before the column capital portion 20L1 of the lower wooden column 20L and the column base portion 20U1 of the upper wooden column 20U are damaged.

[0049] (action) Next, the operation of this embodiment will be described.

[0050] 1 and 2, in the beam-column structure 10 according to this embodiment, the through steel beam 40 has a joint section 40A and a beam section 40B extending from the joint section 40A. The joint section 40A is disposed between the lower wooden column 20L and the upper wooden column 20U.

[0051] Here, the pair of lower support plates 50 extend downward from the joint 40A of the through steel beam 40 and are joined to the column capital 20L1 of the lower wooden column 20L while sandwiching the column capital 20L1 from both sides in the beam axial direction. In addition, the pair of upper support plates 60 extend upward from the joint 40A of the through steel beam 40 and are joined to the column base 20U1 of the upper wooden column 20U while sandwiching the column base 20U1 from both sides in the beam axial direction.

[0052] This allows the joints 40A of the through steel beam 40 to be semi-rigidly connected to the capital part 20L1 of the lower wooden column 20L and the base part 20U1 of the upper wooden column 20U. As a result, bending moments can be transmitted between the joints 40A of the through steel beam 40 and the capital part 20L1 of the lower wooden column 20L and the base part 20U1 of the upper wooden column 20U. This improves the seismic resistance of the beam-column frame 10.

[0053] Furthermore, by passing a through steel beam 40 between the lower wooden column 20L and the upper wooden column 20U, a so-called through beam, the joint 40A of the through steel beam 40 can be easily made semi-rigid between the column head 20L1 of the lower wooden column 20L and the column base 20U1 of the upper wooden column 20U, compared to the case of a through column.

[0054] Furthermore, the pair of lower support plates 50 and the pair of upper support plates 60 are covered with covering concrete 54, 64, respectively. This improves the fire resistance of the lower wooden columns 20L and the upper wooden columns 20U, while also increasing the degree of fixation of the lower wooden columns 20L and the upper wooden columns 20U to the joints 40A of the through steel beams 40. Therefore, the earthquake resistance of the beam-column structure 10 is further improved.

[0055] In addition, the beam portion 40B of the through steel beam 40 is provided with a vibration-damping portion 80. As shown by the two-dot chain line in Fig. 1, this vibration-damping portion 80 absorbs seismic force (vibration energy) by deforming (shearing deformation) and yielding during an earthquake, thereby reducing the seismic force acting on the column capital portion 20L1 of the lower wooden column 20L and the column base portion 20U1 of the upper wooden column 20U.

[0056] As a result, damage to the column capital portion 20L1 of the lower wooden column 20L and the column base portion 20U1 of the upper wooden column 20U during an earthquake is suppressed, and the earthquake resistance performance of the column-beam frame 10 is further improved.

[0057] In particular, in this embodiment, the yield strength of the vibration-damping section 80 is set so that the vibration-damping section 80 yields before the capital part 20L1 of the lower wooden column 20L and the base part 20U1 of the upper wooden column 20U are damaged during an earthquake. Therefore, damage to the capital part 20L1 of the lower wooden column 20L and the base part 20U1 of the upper wooden column 20U can be more reliably prevented.

[0058] Furthermore, the vibration-damping section 80 is provided at the center of the beam section 40B in the material axis direction, where shear force is predominant during an earthquake. This reduces the effect of bending moment on the vibration-damping section 80, making it easier to cause the vibration-damping section 80 to shear yield at a predetermined timing. This makes it easier to design the vibration-damping section 80.

[0059] (Variation) Next, a modification of the above embodiment will be described.

[0060] 1, in the above embodiment, the vibration damping portion 80 is provided in the central portion of the beam portion 40B in the beam axial direction. However, the vibration damping portion 80 is not limited to being provided in the central portion of the beam portion 40B in the beam axial direction, and may be provided, for example, at an end portion of the beam portion 40B in the beam axial direction.

[0061] In the above embodiment, the vibration damping unit 80 is a steel damper. However, the vibration damping unit 80 is not limited to a steel damper, and may be, for example, a viscoelastic damper, a viscous damper, a friction damper, or the like.

[0062] In the above embodiment, a pair of lower support plates 50 is provided on the underside of the lower flange 44 at the joint 40A of the through steel beam 40. However, the lower flange 44 of the joint 40A may be provided with a tubular section with a rectangular cross section into which the wood core 22 of the column capital part 20L1 of the lower wooden column 20L is fitted. In this case, the side walls on both sides of the tubular section that face each other in the beam axial direction serve as a pair of lower support plates.

[0063] Similarly, the upper flange 42 of the joint 40A may be provided with a cylindrical section with a rectangular cross section into which the wood core 22 of the column base 20U1 of the upper wooden column 20U is fitted. In this case, the side walls on both sides of the cylindrical section facing each other in the beam axial direction serve as a pair of upper support plates.

[0064] In the above embodiment, the pair of lower support plates 50 are fire-resistant coated with covering concrete 54. However, the pair of lower support plates 50 may be fire-resistant coated with other fire-resistant coating materials such as rock wool, not limited to covering concrete 54. Similarly, the pair of upper support plates 60 may be fire-resistant coated with other fire-resistant coating materials such as rock wool, not limited to covering concrete 64.

[0065] In the above embodiment, the lower wooden column 20L and the upper wooden column 20U are fire-resistant. However, the lower wooden column 20L and the upper wooden column 20U are not limited to being fire-resistant, and may be semi-fire-resistant or non-fire-resistant.

[0066] In the above embodiment, the through steel beam 40 is formed of an H-shaped steel. However, the through steel beam 40 is not limited to an H-shaped steel, and may be an I-shaped steel, a C-shaped steel, or the like.

[0067] Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and one embodiment and various modified examples may be used in appropriate combination, and it goes without saying that the present invention can be implemented in various forms as long as it does not deviate from the gist of the present invention. [Explanation of symbols]

[0068] 10 Column beam frame 20L lower wood pillar 20L1 Column head 20U upper wooden column 20U1 Column base 40 Through steel beam 40A Connection 40B beam part 50 Lower pressure plate 60 Upper support plate 54 Covering concrete 64 Covering concrete 80 Vibration control section Arrow X: Axis direction of through steel beam

Claims

1. A lower wooden pillar; an upper wooden pole arranged above the lower wooden pole; A through steel beam having a joint portion disposed between the lower wooden column and the upper wooden column and a beam portion extending from the joint portion; a pair of separate lower support plates formed in a flat plate shape, with upper ends joined to the underside of the joint portion and extending downward from the underside, into which the column capitals of the lower wooden columns are fitted and which are joined to the column capitals in a state in which the column capitals are sandwiched from both sides in the material axis direction of the through steel beams; a pair of separate upper support plates formed in a flat plate shape, with their lower ends joined to the upper surface of the joint and extending upward from the upper surface, into which the base of the upper wooden column is fitted and which are joined to the base in a state in which the base is sandwiched from both sides in the material axis direction of the through steel beam; a vibration damping portion provided on the beam portion; A column-beam structure equipped with:

2. and covering concrete covering the upper bearing plate and the lower bearing plate, The column-beam structure according to claim 1.

3. The vibration damping portion is provided at the center of the beam portion in the material axis direction. The column-beam structure according to claim 1 or 2.

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