JP2025093449A - Joint structure of wooden column units and steel beams - Google Patents

Abstract

To provide a joint structure of a wooden column unit and a steel frame beam which has a wooden column unit of high rigidity, and in which intensity of a joint part for joining the wooden column unit and the steel frame beam is high.SOLUTION: In a joint structure 100 of wooden column units 50, 60A, 60B and steel frame beams 80A, 80B, 80C, the wooden column unit includes: rectangular parallelepiped wooden columns 10, 10A; steel boxes 20, 20A disposed at respective cutouts 15 at four corner parts of the wooden column; and a tendon 30 inserted in a through-opening 17 for connecting the two upper and lower steel boxes in the wooden column. In a state of the tendon 30 being strained, the wooden column unit is fixed to a fixing tool 35 inside the upper and lower steel boxes, and by each wooden column unit and steel frame beam being bolt-joined, the plurality of wooden column units and the steel frame beams form a cross shape.SELECTED DRAWING: Figure 4

Description

The present invention relates to a joint structure between a wooden column unit and a steel beam.

The framework that makes up a building (building framework) includes frameworks made of columns and beams of the same material, such as wooden frameworks made of wooden columns and wooden beams, and steel frameworks made of steel columns and steel beams, as well as hybrid frameworks made of wooden columns and steel beams. By using wooden columns instead of steel for both columns and beams, a building framework can be formed that has the high rigidity of steel and the various functions provided by wood. Furthermore, compared to wooden frameworks made of wooden columns and wooden beams, building frameworks have a higher plastic deformation capacity during earthquakes.

Specific examples of the effects of using wood include: compared to steel frames and concrete, wood is lighter, has a high specific strength, and is easy to process. It also has high insulation and moisture-regulating properties. It also has the appearance design that only natural materials can provide, and because it is a natural material, it has low carbon dioxide emissions and is highly effective in reducing environmental impact.

Patent Document 1 proposes a column-beam joint structure consisting of a wooden column and a steel beam. Specifically, a beam load bearing part is provided on the column toward the center from the joint end where the column and beam meet, and a part of the beam's load is transmitted to the beam load bearing part by a joint metal that joins the column and the beam, and the beam's load is supported by the column joint end and the beam load bearing part.

In this beam-column joint structure, a column reinforcement material made of carbon fiber is attached to the outer periphery of the joint end side of the column that contacts the beam. In addition, at least one L-shaped joint metal is attached to the beam and column to join them, and this L-shaped joint metal has a step so that part of the contact surface that contacts the column does not interfere with the reinforcement material.

JP 2011-256616 A

As described above, compared to existing wooden frames formed of wooden pillars and wooden beams, the column-beam joint structure (hybrid structure) consisting of wooden pillars and steel beams described in Patent Document 1 increases the plastic deformation capacity of the building frame during an earthquake. However, in the column-beam joint structure consisting of wooden pillars and steel beams described in Patent Document 1, the pillars and beams are joined by bolting L-shaped joint metal to both the wooden pillars and the steel beams, and since the strength of the joint between the pillar and beam can also be largely dependent on the strength of the L-shaped joint metal, there is room for improvement in the strength of the joint between the pillar and beam.

In addition, because the structure involves joining wooden posts and steel beams, it is necessary to improve the rigidity of the wooden posts to match the rigidity of the steel beams, but there is no mention of this in Patent Document 1.

The present invention was made in consideration of the above problems, and aims to provide a joint structure between a wooden column unit and a steel beam, which has a highly rigid wooden column unit and has a high strength joint that joins the wooden column unit and the steel beam.

In order to achieve the above object, one aspect of the joint structure between a wooden column unit and a steel beam according to the present invention is as follows:
A joint structure of wooden column units and steel beams,
The wooden post units include a first wooden post unit, and a second wooden post unit and a third wooden post unit, each of which has a small end facing a pair of wide sides of the first wooden post unit,
The steel beams include a steel joint arranged above and/or below the first wooden pole unit, a pair of first steel beams arranged above and/or below the first wooden pole unit and joined to the steel joint, a second steel beam arranged above and/or below the second wooden pole unit and joined to the steel joint, and a third steel beam arranged above and/or below the third wooden pole unit and joined to the steel joint,
The wooden pillar unit is
A rectangular wooden pillar,
A steel box is disposed in each of the notches at the four corners of the wooden pole;
A tension member is inserted into a through opening connecting the two steel boxes at the top and bottom of the wooden pole,
The steel box comprises a pair of upper and lower plates and a plurality of side plates connecting the pair of upper and lower plates, one of the pair of upper and lower plates is provided with a first hole through which the tension member is inserted, the other of the pair of upper and lower plates is provided with a second hole through which a bolt is inserted when the steel box is bolted to the steel beam, and access openings are provided midway between the plurality of side plates to freely access the inside of the steel box,
An end of the tension member is inserted into each of the first holes of the upper and lower steel boxes, and the tension member is fixed to a fixing device inside each of the steel boxes in a tensioned state,
Each steel beam is provided with a third hole through which a bolt is inserted when the steel beam is bolted to the steel box;
A bolt is inserted into the second hole of each wooden pillar unit and the third hole of the corresponding steel beam, and the wooden pillar units and the steel beam are bolted together to form a cross shape.

According to this aspect, in a joint structure in which multiple wooden column units and steel beams form a cross shape, a steel box is disposed in each of the notches at the four corners of the wooden columns that make up each wooden column unit, and the steel box is bolted to the steel beam by a bolt inserted into the second hole of the steel box, so that the wooden column and the steel beam are joined via a steel box that has higher rigidity than an L-shaped joint metal, thereby increasing the strength of both joints. Furthermore, the tension material inserted into the through opening inside the wooden column is tensioned, and its end is fixed to the fixing device inside the upper and lower steel boxes, so that the tension material applies a compressive force to the wooden column, increasing the rigidity of the wooden column.

Here, examples of configurations include a configuration in which one tension member is arranged for each through opening between a pair of upper and lower steel boxes on the left and right sides, for a total of two tension members, and a configuration in which multiple tension members (e.g., two) are arranged for each of multiple through openings (e.g., two) for a total of four tension members. In addition, "through opening" includes both a through hole extending between a pair of upper and lower cutouts, and a through groove provided inside the wooden pole from the wide surface or side surface (small end) and the like, and extending between a pair of upper and lower cutouts.

In addition, one or more access openings are provided in the middle of the side panels of the steel box, so that fasteners can be transferred to the inside of the steel box through the access openings and attached to the ends of the tendons. Furthermore, workers can manually tighten the fasteners inside the steel box through the access openings.

Here, "arranged above and/or below the wooden column unit" includes a configuration in which the steel joints or steel beams are arranged either above or below the wooden column unit, and a configuration in which they are arranged both above and below the wooden column unit.

In addition, in this embodiment, the ends of both the second and third wooden post units face a pair of wide sides of the first wooden post unit, so the first wooden post unit becomes the so-called winning wooden post unit, while the second and third wooden post units become the so-called losing wooden post units.

"Wooden pillars" include ordinary wooden pillars as well as wooden wall pillars. In addition, PC (Prestressed Concrete) steel bars and PC steel wires can be used as "tensioning materials." A sheath tube may be provided inside the through opening. Furthermore, the tensioning materials can be bonded PC pressure-bonded materials using the bonded PC pressure-bonding method, in which the tensioning materials are pressure-bonded via grout filled inside the through opening (or sheath tube), or unbonded PC pressure-bonded materials using the unbonded PC pressure-bonding method, which does not require grout filling.

Another aspect of the joint structure between a wooden column unit and a steel beam according to the present invention is as follows:
A joint structure of wooden column units and steel beams,
The wooden post unit includes a first wooden post unit and a second wooden post unit whose small end faces one of the wide surfaces of the first wooden post unit,
The steel beam includes a steel joint disposed above and/or below the first wooden pole unit, a pair of first steel beams disposed above and/or below the first wooden pole unit and joined to the steel joint, and a second steel beam disposed above and/or below the second wooden pole unit and joined to the steel joint,
The wooden pillar unit is
A rectangular wooden pillar,
A steel box is disposed in each of the notches at the four corners of the wooden pole;
A tension member is inserted into a through opening connecting the two steel boxes at the top and bottom of the wooden pole,
The steel box comprises a pair of upper and lower plates and a plurality of side plates connecting the pair of upper and lower plates, one of the pair of upper and lower plates is provided with a first hole through which the tension member is inserted, the other of the pair of upper and lower plates is provided with a second hole through which a bolt is inserted when the steel box is bolted to the steel beam, and access openings are provided midway between the plurality of side plates to freely access the inside of the steel box,
An end of the tension member is inserted into each of the first holes of the upper and lower steel boxes, and the tension member is fixed to a fixing device inside each of the steel boxes in a tensioned state,
Each steel beam is provided with a third hole through which a bolt is inserted when the steel beam is bolted to the steel box;
A bolt is inserted into the second hole of each wooden pillar unit and the third hole of the corresponding steel beam, and the wooden pillar units and the steel beam are bolted together to form a T-shape.

According to this aspect, in a joint structure in which multiple wooden column units and steel beams form a T-shape, a steel box is disposed in each of the notches at the four corners of the wooden columns that make up each wooden column unit, and the steel box is bolted to the steel beam by a bolt inserted into the second hole of the steel box, so that the wooden column and the steel beam are joined via a steel box that has higher rigidity than an L-shaped joint metal, thereby increasing the strength of both joints. Furthermore, the tension material inserted into the through opening inside the wooden column is tensioned, and its end is fixed to the fixing device inside the upper and lower steel boxes, so that the tension material applies a compressive force to the wooden column, increasing the rigidity of the wooden column.

In this embodiment, the narrow end of the second wooden post unit faces a pair of wide sides of the first wooden post unit, so the first wooden post unit becomes the so-called winning wooden post unit, while the second wooden post unit becomes the so-called losing wooden post unit.

Another aspect of the joint structure between a wooden column unit and a steel beam according to the present invention is as follows:
A gap is provided between the wide surface of the first wooden post unit and the small end of the second wooden post unit or the small end of the third wooden post unit.

According to this aspect, a gap is provided between the wide surface of the first wooden column unit and the end of the second or third wooden column unit, which prevents the end of the second or third wooden column unit on the losing side from sinking into the wide surface of the first wooden column unit when the frame undergoes inter-story deformation during an earthquake.

Another aspect of the joint structure between a wooden column unit and a steel beam according to the present invention is as follows:
The steel joint is characterized in that it is arranged at a central position in the longitudinal direction above and/or below the first wooden pole unit.

According to this aspect, the steel joint is disposed in the longitudinal center above and/or below the first wooden column unit, so that the joint of the steel beam is similarly located in the longitudinal center above or below the first wooden column unit, and it is possible to prevent, for example, the joint between the steel beams from being located outside the wooden column unit. For example, in the case where the steel joint is located in the longitudinal center above the first wooden column unit, the joint between the multiple steel beams is this one location, but if the joint between the steel beams is located outside the wooden column unit, the number of joints will simply be two, one on the left and one on the right of the wooden column unit, increasing the number of joints, leading to reduced workability and, further, an unbalanced arrangement of steel beams in which a short beam is installed between other wooden column units.

Another aspect of the joint structure between a wooden column unit and a steel beam according to the present invention is as follows:
The steel joint is characterized in that it has a rectangular box shape with an access opening at the top or bottom.

According to this aspect, the steel joint has a rectangular box shape with an access opening above or below, which improves workability when multiple steel beams are joined to the steel joint from two to four directions. For example, a steel joint placed above a wooden column unit has an access opening above it, and a steel joint placed below a wooden column unit has an access opening below it.

Another aspect of the joint structure between a wooden column unit and a steel beam according to the present invention is as follows:
The beam configurations of the two steel beams connected via the steel joints are different above and/or below the wooden column unit,
The wooden column unit is characterized in that the areas above and/or below the wooden column unit, which correspond to the steel beams having a relatively high beam depth, are recessed due to the difference in beam depth between the two.

According to this aspect, in a configuration having a step beam in which the beam formation of both steel beams connected via a steel joint is different, the area above and/or below the wooden column unit that corresponds to the steel beam with a relatively high beam formation is recessed due to the difference in beam formation between the two, so that when two step beams are arranged above or below the wooden column unit, the top ends of both step beams can be aligned flush.

Another aspect of the joint structure between a wooden column unit and a steel beam according to the present invention is as follows:
The tension member is characterized in that it is an unbonded PC crimped material.

According to this embodiment, the tension material is an unbonded PC pressure-bonded material, which eliminates the need to place a sheath tube in the through hole or fill it with grout, and allows the wooden column unit to be manufactured using a pressure-bonding method that is easy to manufacture.

In another aspect of the joint structure between the wooden column unit and the steel beam according to the present invention,
The first hole is formed at the center of the thickness of the wooden pole and at the center of the width of the steel box.

According to this embodiment, the first hole through which the end of the tensioning material is inserted is located at the center of the thickness of the wooden pole and at the center of the width of the steel box, so that multiple tensioning materials can be arranged at the center of the thickness of the wooden pole, and a compressive force can be effectively applied to the entire wooden pole.

In another aspect of the joint structure between the wooden column unit and the steel beam according to the present invention,
The wooden pillar is a wall pillar formed from any one of a plurality of square timber units, laminated timber, solid wood, structural plywood, laminated veneer lumber, and cross-laminated timber.

According to this aspect, the wooden column is a wall column formed from one of multiple square timber units, laminated timber, solid wood, structural plywood, laminated veneer lumber, and cross laminated timber, so that the wall column functions as a load-bearing wall even while using a wooden column. For example, by adjusting the number of square timbers or the width of laminated veneer lumber (LVL) or cross laminated timber (CLT), a wall column with the desired rigidity (earthquake resistance) can be formed.

As can be understood from the above explanation, the joint structure between a wooden column unit and a steel beam of the present invention can provide a joint structure between a wooden column unit and a steel beam that has a highly rigid wooden column unit and has a high strength joint that joins the wooden column unit and the steel beam.

1 is a front view of an example of a wooden column unit that forms a joint structure between a wooden column unit and a steel beam according to an embodiment of the present invention. FIG. This is a cross-sectional view taken along the line II-II in Figure 1, in which the wooden pole unit is cut at a midpoint of the steel box and viewed downward. FIG. 1 is a perspective view of an example of a steel box. This is a vertical cross-sectional view showing an example of a joint structure between a wooden pillar unit and a steel beam in accordance with an embodiment of the present invention, cut at a midpoint of the second wooden pillar unit. This is a view taken along the VV arrow in Figure 4, and is a cross-sectional view showing an example of a joint structure between a wooden pillar unit and a steel beam in an embodiment, cut at a midpoint of the wooden pillar. This is a view taken along the line VI-VI in Figure 5, and is a vertical cross-sectional view showing an example of a joint structure between a wooden pillar unit and a steel beam in an embodiment, cut at a midpoint of the first wooden pillar unit. FIG. 1 is a perspective view of an example of a steel joint. A diagram explaining a modified example of a wooden pillar unit and the fit of a step beam. FIG. 8B is a front view of the top of a wooden pole constituting a modified example of the wooden pole unit shown in FIG. 8A.

Below, an example of a joint structure between a wooden column unit and a steel beam according to an embodiment will be described with reference to the attached drawings, along with an example of a wooden column unit that forms the joint structure. Note that in this specification and the drawings, substantially identical components may be designated by the same reference numerals to avoid redundant description.

[Joint structure between wooden column unit and steel beam according to the embodiment]
An example of a joint structure between a wooden column unit and a steel beam according to the embodiment will be described with reference to Figs. 1 to 8. Here, Fig. 1 is a front view of an example of a wooden column unit forming a joint structure between a wooden column unit and a steel beam according to the embodiment, Fig. 2 is a cross-sectional view of the wooden column unit cut at the middle position of the steel box and looking downward, which is a view taken along the II-II arrow in Fig. 1, and Fig. 3 is a perspective view of an example of a steel box. Fig. 4 is a vertical cross-sectional view of an example of a joint structure between a wooden column unit and a steel beam according to the embodiment, cut at the middle position of the second wooden column unit. Furthermore, Fig. 5 is a view taken along the V-V arrow in Fig. 4, and Fig. 6 is a cross-sectional view of an example of a joint structure between a wooden column unit and a steel beam according to the embodiment, cut at the middle position of the wooden column, which is a view taken along the VI-VI arrow in Fig. 5, and Fig. 7 is a perspective view of an example of a steel joint.

As shown in FIG. 1, the first wooden pillar unit 50 (an example of a wooden pillar unit) has a rectangular wooden pillar 10, with rectangular notches 15 provided at the four corners of the wooden pillar 10, and a steel box 20 is disposed in each of the notches 15.

The wooden pillar 10 is a wall pillar, and with regard to the cross-sectional dimensions shown in FIG. 2 perpendicular to the axial direction of the pillar, the width t2 in the wall thickness direction (width direction) is, for example, approximately the same as the wall thickness or larger than the wall thickness (when the thickness of the insulation material and exterior material is added, the width in the wall thickness direction can generally be larger than the wall thickness), and the width t1 (see FIG. 1) in the direction perpendicular to the wall thickness is about two to several times the width t2 in the wall thickness direction, and the pillar has a rectangular cross section with a wide wide surface 14.

The rectangular notches 15 described above are provided at each of the four corners formed by the upper end surface 11, the lower end surface 12, and the left and right side surfaces 13.

The wooden wall pillars 10 are made from multiple log units, laminated timber, solid wood, structural plywood, laminated veneer lumber (LVL), or cross-laminated timber (CLT).

Two through openings 17 (four through openings 17 in total) are provided at the center in the wall thickness direction, spanning a pair of upper and lower cutouts 15 on the left and right. Here, the through openings 17 shown in FIG. 1 are through holes.

As shown in FIG. 3, the steel box 20 has an external shape complementary to the notch 15 provided in the wooden pole 10, is rectangular in plan view, and has a pair of upper and lower plates 21, 22 and three side plates 23, with an access opening 25 provided midway through the side plate 23 to allow free access to the inside of the steel box 20.

Unlike the L-shaped metal joint described in Patent Document 1, the steel box 20 has a box shape and is therefore a highly rigid joint member. Here, the steel box 20 may be manufactured as a single unit by casting or the like, or may be manufactured by welding together plates of flat steel.

When the steel box 20 is placed in the cutout 15, a first hole 26 is opened at a position corresponding to the two through holes 17 in the upper and lower plates 22 below the steel box 20.

A steel box 20 is placed in the upper cutout 15 in the position shown in FIG. 3, and a steel box 20 is placed in the lower cutout 15 in the position shown in FIG. 3, but upside down.

As shown in FIG. 3, the first hole 26 is opened at the center position (t2/2) of the width t2 of the steel box 20, and therefore, as shown in FIG. 2, when the steel box 20 is placed in the notch 15, it is located at the center position of the thickness of the wooden pole 10.

As shown in FIG. 3, in the steel box 20 placed in the upper notch 15, the upper top and bottom plates 21 have a plurality of second holes 27 (six in the illustrated example) that are aligned with a plurality of third holes 84 in the lower flange 83 of the first steel beam 80A (an example of a steel beam, see FIG. 4) and through which bolts 88B are inserted, and the first wooden column unit 50 and the first steel beam 80A are bolted together by the bolts 88B inserted through the corresponding second holes 27 and third holes 84.

As shown in Figures 1 and 2, the end 32 of the tension member 30 inserted through each through hole 17 is inserted into the first hole 26 of each of the upper and lower steel boxes 20, and the tension member 30 is fixed to the steel box 20 with the fixing device 35 inside the steel box 20 in a tensioned state, thereby producing a first wooden column unit 50 in which the wooden column 10 and the four steel boxes 20 at the corners are integrated. Here, the first wooden column unit 50 is produced in a factory or a production yard at the site, and the first wooden column unit 50 is erected at the site, and the upper and lower first steel beams 80A (see Figure 4) are joined to the first wooden column unit 50.

Here, the method of introducing tension into the tendon 30 is, for example, to attach the fixing device 35 in the lower steel box 20 to the lower end 32 of the tendon 30, tension the end 32 of the tendon 30 in the upper steel box 20, and attach the fixing device 35 to the end 32.

Specific methods for introducing tension into the tensioning material 30 include manually tightening the tensioning material 30 through the access opening 25, or by setting the dimensions of the steel box 20 relatively large and installing a tensioning device (tensioning jack) (not shown) inside the steel box 20 to introduce tension.

The tension member 30 in the illustrated example is an unbonded PC crimping material, and is installed using the unbonded PC crimping method, which does not require the placement of a sheath tube in the through hole 17 or the filling of grout, and therefore is crimped with excellent workability. Note that a bonded PC crimping method, in which the tension member is crimped via grout filled inside the through hole 17, may also be applied.

The through opening 17 provided in the wooden pole 10 is a through hole as in the illustrated example, but the through opening may also be a through groove (not shown). Specifically, there is a form in which a through groove is dug from one wide surface 14 of the wooden pole 10 to the arrangement position of the corresponding tension material 30, and extends so as to straddle the upper and lower notches 15, a form in which a through groove is dug from two wide surfaces 14 of the wooden pole 10 to the arrangement position of the corresponding tension material 30, and extends so as to straddle the upper and lower notches 15, and further, a form in which a through groove 17B is dug from the side surface 13 (small end) of the wooden pole 10 to the arrangement position of the two tension materials 30, and extends so as to straddle the upper and lower notches 15.

In the joint structure 100 between the wooden column unit and the steel beam shown in Figures 4 to 7, the ends 13 of the second wooden column unit 60A (another example of a wooden column unit) and the third wooden column unit 60B (another example of a wooden column unit) are arranged opposite the pair of wide faces 14 of the first wooden column unit 50 shown in Figure 1 with a gap G between them, and the three wooden column units 50, 60A, 60B are arranged in a cross shape. In other words, the first wooden column unit 50 is the so-called winning wooden column unit, while the second wooden column unit 60A and the third wooden column unit 60B are the so-called losing wooden column units.

Here, in the illustrated example, the width t3 in the direction perpendicular to the wall thickness of the wooden pole 10A forming the second wooden pole unit 60A and the third wooden pole unit 60B is set shorter than that of the first wooden pole unit 50, the second wooden pole unit 60A and the third wooden pole unit 60B have one through opening 17 (two in total on the left and right) that spans the upper and lower steel boxes 20A, and the upper and lower plates 21 of the steel box 20A have a total of four second holes 27 (two of which are shown in FIG. 6). Although there are differences in the dimensions and number of components between the first wooden pole unit 50 and the second wooden pole unit 60A and the third wooden pole unit 60B, the basic configuration of the three wooden pole units 50, 60A, and 60B is the same. Note that the second wooden pole unit and the third wooden pole unit may have the same configuration as the first wooden pole unit (all three wooden pole units are the same).

The joint structure 100 shown in Figures 4 to 7 is a joint structure between wooden column units 50, 60A, 60B and upper and lower steel beams 80 in the upper floor structure of, for example, a two- or three-story (multiple-story) building, condominium, nursing home, etc.

The first steel beam 80A is made of an H-shaped steel with a web 81, an upper flange 82, and a lower flange 83, and the lower flange 83 of the upper first steel beam 80A is abutted against the upper surface of the upper and lower plates 21 of the steel box 20 above the first wooden column unit 50, and high-strength bolts 88B are inserted through the second holes 27 of the upper and lower plates 21 and the third holes 84 at corresponding positions of the lower flange 83, and bolted together. Here, the first steel beam 80A is provided with a reinforcing rib 65 at a position corresponding to the side plate 23 of the steel box 20.

Similarly, the upper flange 82 of the lower first steel beam 80A is abutted against the underside of the lower upper and lower plates 21 of the steel box 20 below the first wooden column unit 50, and high-strength bolts 88B are inserted through each second hole 27 of the upper and lower plates 21 and the third hole 84 at the corresponding position of the upper flange 82, and bolted together.

A steel joint 70 shown in Figure 7 is provided at the center of the upper and lower longitudinal directions (X direction in Figure 4) of the first wooden pillar unit 50.

The steel joint 70 is made of steel and has a rectangular box shape, with four side walls 71 and one bottom plate 72 (or top plate 72), and an access opening 75 at the top or bottom that leads to the interior.

The state shown in Figure 7 shows a position in which the bottom plate 72 is located below and is positioned above the first wooden pillar unit 50. On the other hand, when it is positioned below the first wooden pillar unit 50, it is used in a position in which the top plate 72 is facing the first wooden pillar unit 50, with the top plate 72 facing the first wooden pillar unit 50.

Each side wall 71 has multiple (four in the illustrated example) fourth holes 73. As shown in FIG. 4, an end plate 85 is welded to the end of the first steel beam 80A, and the end plate 85 has multiple bolt holes (not shown), which are aligned with the corresponding fourth holes 73 and bolted together.

More specifically, steel joints 70 are placed at the center positions of the top and bottom of the first wooden column unit 50 in the longitudinal direction, and the end plates 85 of the two first steel beams 80A on the left and right are bolted to a pair of opposing side walls 71 of each steel joint 70. When bolting, the joining work can be performed through the access openings 75 of the steel joints 70.

On the other hand, the other pair of opposing side walls 71 of the steel joint 70 are abutted against the end plates 86 at the ends of the second steel beam 80B and the third steel beam 80C arranged above and below the second wooden pillar unit 60A and the third wooden pillar unit 60B shown in FIG. 6, respectively, and bolts are inserted into the bolt holes (not shown) and the fourth hole 73 opened in each end plate 86 to connect them.

In this way, a pair of first steel beams 80A, second steel beams 80B, and third steel beams 80C extending in four perpendicular directions are bolted to the steel joints 70 located at the center of the vertical longitudinal direction of the first wooden pillar unit 50, forming a joint structure 100 in which the three wooden pillar units 50, 60A, 60B and the four steel beams 80A, 80A, 80B, 80C form a cross shape.

Here, the construction method of the joint structure 100 can be outlined as follows. First, as already explained, the first wooden pillar unit 50A, the second wooden pillar unit 60A, and the third wooden pillar unit 60B, which are prefabricated in a factory and to which tension is applied by the tendons 30, are transported to the site.

At the site, the two lower first steel beams 80A are bolted to the steel joints 70 using the access openings 75 of the steel joints 70, the first wooden column unit 50 is placed above them, and the pair of steel boxes 20 below the first wooden column unit 50 are bolted to the upper flanges 82 of each first steel beam 80A using the access openings 25 of the steel boxes 20.

Next, a first steel beam 80A is placed above the first wooden column unit 50, and the lower flange 83 of the first steel beam 80A is bolted to one of the steel boxes 20 above the first wooden column unit 50 using the access opening 75, and the side wall 71 of the steel joint 70 is bolted to the end plate 85 of the first steel beam 80A using the access opening 25.

Next, the end plate 85 of the separate first steel beam 80A is bolted to the side wall 71 of the steel joint 70 and to the steel box 20, thereby bolting the upper and lower steel joints 70 and the pair of first steel beam 80A units and the first wooden column unit 50 between them.

Next, the lower end plates 86 of the second steel beam 80B and the third steel beam 80C are bolted to the lower steel joint 70, and the lower pair of steel boxes 20A of the second wooden column unit 60A and the third wooden column unit 60B are bolted to the upper flanges 82 of the second steel beam 80B and the third steel beam 80C.

Next, a second steel beam 80B is placed above the second wooden column unit 60A, and the pair of steel boxes 20A above the second wooden column unit 60A are bolted to the lower flange 83 of the second steel beam 80B, and the side wall 71 of the steel joint 70 is bolted to the end plate 86 of the second steel beam 80B.

Next, the end plate 86 of the third steel beam 80C is bolted to the side wall 71 of the steel joint 70 and to the steel box 20A, thereby constructing a joint structure 100 in which the three wooden column units 50, 60A, 60B and the four steel beams 80A, 80A, 80B, 80C form a cross shape.

According to the connection structure 100 between the wooden column units and the steel beams, in the connection structure 100 in which a plurality of wooden column units 50, 60A, 60B and the steel beams 80A, 80A, 80B, 80C form a cross shape, steel boxes 20, 20A are arranged in the notches 15 at each of the four corners of the wooden columns 10, 10A that constitute each wooden column unit 50, 60A, 60B, and the steel boxes 20, 20A are bolted to the steel beams 80A, 80B, 80C by bolts inserted into the second holes 27 of the steel boxes 20, 20A. As a result, the wooden columns 10, 10A and the steel beams 80A, 80B, 80C are joined via the steel boxes 20, 20A, which have higher rigidity than L-shaped joint hardware, and the strength of both joints can be increased. Furthermore, the tensioning material 30 inserted through the through opening 17 inside the wooden poles 10, 10A is tensioned, and its end is fixed to the fixing device 35 inside the upper and lower steel boxes 20, 20A, so that the tensioning material 30 in the tensioned state applies a compressive force to the wooden poles 10, 10A, increasing the rigidity of the wooden poles 10, 10A.

In addition, by arranging the steel joints 70 at the longitudinal center positions above and below the first wooden pillar unit 50, the joints of the first steel beams 80A are similarly located at the longitudinal center positions above and below the first wooden pillar unit 50, which prevents, for example, the joints between the first steel beams 80A from being located outside the first wooden pillar unit 50.

In addition, by providing a gap G between the wide surface 14 of the first wooden column unit 50 on the so-called winning side and the end 13 of the second wooden column unit 60A and the third wooden column unit 60B on the so-called losing side, when the frame undergoes inter-story deformation during an earthquake, the end 13 of the second wooden column unit 60A or the third wooden column unit 60B on the losing side can be prevented from sinking into the wide surface 14 of the first wooden column unit 50. Here, the size of the gap can be set, for example, to a size that can absorb the amount of horizontal displacement of the frame during inter-story deformation required by the design.

In relatively large, multi-storey buildings, the outer perimeter columns alone may not be able to adequately withstand the horizontal forces during an earthquake, but by applying the joint structure 100 shown in the figure to the frame of each floor, it becomes possible to adequately withstand the horizontal forces during an earthquake while still employing the commonly used cross-shaped wall arrangement.

Although not shown here, the joint structure between the wooden pillar unit and the steel beam may be a cross-shaped structure as shown in the example, or may be a T-shaped joint structure in which, for example, the third wooden pillar unit 60B and the third steel beams 80C above and below it in FIG. 5 do not exist.

Figures 8A and 8B show a wooden pillar that corresponds to the step beam and how the steel beam fits into the wooden pillar. Here, Figure 8A is a diagram explaining a modified wooden pillar unit and how the step beam fits, and Figure 8B is a front view of the top of a wooden pillar that constitutes a modified wooden pillar unit shown in Figure 8A.

As shown in FIG. 8A, the left and right steel beams 80A and 80A' above the wooden column unit 50A have different beam lengths t5 and t6 (t5 > t6).

When such a step beam is installed, as shown in FIG. 8B, a recess 10a equivalent to the difference between beam depths t5 and t6 is provided in the upper end surface 11A of the wooden column 10A constituting the wooden column unit 50A in the region corresponding to the steel beam 80A with a relatively high beam depth.

As a result, as shown in FIG. 8A, when a pair of steel beams 80A, 80A', which are bolted to each other via steel joints 70 at the upper end surface 11A of the wooden column unit 50A, are each bolted to a pair of steel boxes 20 of the wooden column unit 50A, the upper surfaces of the pair of steel beams 80A, 80A' can be made flush, making it possible to install flooring materials for the upper floors without any steps on their upper surfaces.

Note that the configurations described in the above embodiments may be combined with other components, and the present invention is not limited to the configurations shown here. In this regard, changes can be made without departing from the spirit of the present invention, and can be determined appropriately according to the application form.

10, 10A, 10B: Wooden pillar 10a: Hollow 11, 11A: Upper end surface 12: Lower end surface 13: Side surface (edge)
14: Wide surface 15: Notch 17: Through opening (through hole)
20, 20A: Steel box 21: Upper and lower plates (upper upper and lower plates)
22: Upper and lower boards (lower upper and lower boards)
23: Side plate 25: Access opening 26: First hole 27: Second hole 30: Tendon 32: End 35: Fixing device 50: First wooden pole unit (wooden pole unit)
60A: Second wooden pillar unit (wooden pillar unit)
60B: Third wooden pillar unit (wooden pillar unit)
70: Steel joint 71: Side wall 72: Bottom plate (top plate)
73: Fourth hole 75: Access opening 80A, 80A': First steel beam (steel beam)
80B: Second steel beam (steel beam)
80C: Third steel beam (steel beam)
81: Web 82: Upper flange 83: Lower flange 84: Third hole 85, 86: End plate 87: Reinforcing rib 88A, 88B: Bolts (high strength bolts)
100: Joint structure (joint structure between wooden column unit and steel beam)
G: Gap

Claims (9)

A joint structure of wooden column units and steel beams,
The wooden post units include a first wooden post unit, and a second wooden post unit and a third wooden post unit, each of which has a small end facing a pair of wide sides of the first wooden post unit,
The steel beams include a steel joint arranged above and/or below the first wooden pole unit, a pair of first steel beams arranged above and/or below the first wooden pole unit and joined to the steel joint, a second steel beam arranged above and/or below the second wooden pole unit and joined to the steel joint, and a third steel beam arranged above and/or below the third wooden pole unit and joined to the steel joint,
The wooden pillar unit is
A rectangular wooden pillar,
A steel box is disposed in each of the notches at the four corners of the wooden pole;
A tension member is inserted into a through opening connecting the two steel boxes at the top and bottom of the wooden pole,
The steel box comprises a pair of upper and lower plates and a plurality of side plates connecting the pair of upper and lower plates, one of the pair of upper and lower plates is provided with a first hole through which the tension member is inserted, the other of the pair of upper and lower plates is provided with a second hole through which a bolt is inserted when the steel box is bolted to the steel beam, and access openings are provided midway between the plurality of side plates to freely access the inside of the steel box,
An end of the tension member is inserted into each of the first holes of the upper and lower steel boxes, and the tension member is fixed to a fixing device inside each of the steel boxes in a tensioned state,
Each steel beam is provided with a third hole through which a bolt is inserted when the steel beam is bolted to the steel box;
A connection structure between wooden column units and steel beams, characterized in that bolts are inserted into the second holes of each wooden column unit and the corresponding third holes of the steel beams, and the wooden column units and steel beams are bolted together to form a cross shape. A joint structure of wooden column units and steel beams,
The wooden post unit includes a first wooden post unit and a second wooden post unit whose small end faces one of the wide surfaces of the first wooden post unit,
The steel beam includes a steel joint disposed above and/or below the first wooden pole unit, a pair of first steel beams disposed above and/or below the first wooden pole unit and joined to the steel joint, and a second steel beam disposed above and/or below the second wooden pole unit and joined to the steel joint,
The wooden pillar unit is
A rectangular wooden pillar,
A steel box is disposed in each of the notches at the four corners of the wooden pole;
A tension member is inserted into a through opening connecting the two steel boxes at the top and bottom of the wooden pole,
The steel box comprises a pair of upper and lower plates and a plurality of side plates connecting the pair of upper and lower plates, one of the pair of upper and lower plates is provided with a first hole through which the tension member is inserted, the other of the pair of upper and lower plates is provided with a second hole through which a bolt is inserted when the steel box is bolted to the steel beam, and access openings are provided midway between the plurality of side plates to freely access the inside of the steel box,
An end of the tension member is inserted into each of the first holes of the upper and lower steel boxes, and the tension member is fixed to a fixing device inside each of the steel boxes in a tensioned state,
Each steel beam is provided with a third hole through which a bolt is inserted when the steel beam is bolted to the steel box;
A connection structure between wooden column units and steel beams, characterized in that bolts are inserted into the second holes of each wooden column unit and the corresponding third holes of the steel beams, and the wooden column units and the steel beams are bolted together to form a T-shape. The joining structure between the wooden pillar unit and the steel beam according to claim 1 or 2, characterized in that a gap is provided between the wide surface of the first wooden pillar unit and the small end of the second wooden pillar unit or the third wooden pillar unit. The joining structure between a wooden column unit and a steel beam according to claim 1 or 2, characterized in that the steel joint is disposed at a central position in the longitudinal direction above and/or below the first wooden column unit. The joining structure between a wooden column unit and a steel beam according to claim 1 or 2, characterized in that the steel joint is a rectangular box shape with an access opening at the top or bottom. The beam configurations of the two steel beams connected via the steel joints are different above and/or below the wooden column unit,
The joint structure between a wooden column unit and a steel beam as described in claim 1 or 2, characterized in that the area above and/or below the wooden column unit corresponding to the steel beam, which has a relatively high beam depth, is recessed due to the difference in beam depth between the two. The joint structure between a wooden column unit and a steel beam according to claim 1 or 2, characterized in that the tension member is an unbonded PC pressure-bonded material. The joining structure between the wooden pole unit and the steel beam described in claim 1 or 2, characterized in that the first hole is opened at the center position of the thickness of the wooden pole and at the center position of the width of the steel box. The joining structure of a wooden column unit and a steel beam according to claim 1 or 2, characterized in that the wooden column is a wall column formed from one of a plurality of square timber units, laminated timber, solid wood, structural plywood, laminated veneer lumber, and cross-laminated timber.

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