JP7586679B2 - Wooden stacked shaft members - Google Patents

Description

The present invention relates to a wooden stacked shaft member.

In wooden buildings constructed using wooden framework construction, wooden beams can have large spans, but because there is a limit to the length of wooden beams that can be transported by regular trucks, it is necessary to transport them to the site using special large trucks, which poses the problem of high transportation costs. As a result, measures to curb rising transportation costs can be taken by dividing large-span wooden beams into multiple split wooden beams and transporting the split wooden beams by regular trucks.

When a large span wooden beam is made into multiple split wooden beams as described above, it becomes necessary to transport the split wooden beams to the site and then join the multiple split wooden beams together to produce a large span wooden beam. In this case, a wooden beam is produced with a joint structure with high joint strength so that the joints between the split wooden beams do not become structurally weak. However, by increasing the joint strength of the joints, it becomes difficult to suppress deformation of the wooden beam.

One possible solution is to change the approach from increasing the rigidity of the joints between the split wooden beams to creating a wooden truss beam that places as little bending stress on the joints as possible. Alternatively, another wooden beam can be connected across the joints of the split wooden beams to suppress the deflection of the wooden beams. However, all of these wooden beams require a relatively large dimension below the wooden beam, which puts pressure on the ceiling space and may reduce the design freedom in the vertical structural plane of the building.

For these reasons, there is a demand for wooden shaft members, such as large-span wooden beams and tall wooden columns, that are easy to transport and do not reduce the design freedom of the building's vertical structural components.

Here, a long wooden building material with excellent rigidity and strength is proposed, which is formed by connecting and integrating at least two pieces of laminated timber in the longitudinal direction on-site. Specifically, this is a wooden building material in which at least two pieces of laminated timber are joined in the longitudinal direction, the wooden laminated timber is reinforced by a tubular reinforcing material that penetrates it in the longitudinal direction, a tension material is provided inside the tube of the tubular reinforcing material that penetrates the tube of the at least two wooden laminated timbers in the longitudinal direction, and tension is applied to the tension material, thereby fixing the at least two wooden laminated timbers in a state where they are joined in the longitudinal direction (see, for example, Patent Document 1).

JP 2020-133212 A

The wooden building material described in Patent Document 1 has the above-mentioned problem that it is difficult to suppress deformation of the wooden building material because the joints between the laminated wood timber pieces are made to have high rigidity and strength.

The present invention was made in consideration of the above problems, and aims to provide a wooden overlapping shaft member for wooden shaft members such as large-span wooden beams and tall wooden columns that is easy to transport and does not reduce the design freedom of the vertical structural plane of a building.

In order to achieve the above object, one aspect of the wooden stacking shaft member according to the present invention is as follows:
A wooden overlapping shaft member in which a plurality of wooden shaft members including at least a first wooden shaft member and a second wooden shaft member are overlapped and integrated,
Each of the first and second wood shaft members includes at least two split wood shaft members, and the joint end surfaces of the two split wood shaft members are abutted to form a joint interface. The first and second wood shaft members are formed by joining the two split wood shaft members with a first joining means.
The joint interfaces of the first wood shaft member and the second wood shaft member are arranged at positions offset from each other in the axial direction, the side surfaces extending in the weak axis direction in the axial orthogonal cross sections of the first wood shaft member and the second wood shaft member abut against each other as overlapping surfaces, and the first wood shaft member and the second wood shaft member are joined by a second joining means.

According to this embodiment, the wooden overlapping shaft member is formed of at least two first and second wooden shaft members, each of which is formed of two split wooden shaft members joined to each other via a joint interface, and the joint interfaces of the wooden shaft members are arranged in positions offset in the axial direction and joined together, thereby achieving excellent transportability. For example, even in a large span wooden overlapping shaft member of about 10 m, the length of the split wooden shaft members constituting the first and second wooden shaft members, which are its constituent elements, can be adjusted to a length that can be transported by a general truck. In addition, by joining the joint interface of the first wooden shaft member and the joint interface of the second wooden shaft member formed by the two split wooden shaft members at positions offset in the axial direction of the wooden overlapping shaft member, the joint interface of one wooden shaft member is reinforced by the other wooden shaft member straddling it, and the strength of the joint interface (joint) can be increased without providing special reinforcement to the joint interface of the wooden shaft members.

Furthermore, the side surfaces of the first and second wooden shaft members extending in the weak axis direction in the cross section perpendicular to the axis of each member are abutted against each other as overlapping surfaces, in other words, the two wooden shaft members are not overlapped in the height direction but in the width direction, so that when the wooden overlapping shaft member of this embodiment is applied to the vertical structural surface of a building as a wooden beam or wooden column, there is no risk of narrowing the internal space of the vertical structural surface and reducing the design freedom. Note that in a normal overlapping beam, in order to increase its bending strength, for example, the side surfaces extending in the strong axis direction in the cross section perpendicular to the axis of the shaft members are abutted against each other as overlapping surfaces. However, this embodiment is a wooden overlapping shaft member that differs from conventional overlapping beams in that it is formed by overlapping overlapping surfaces that are different from normal overlapping beams.

Here, the length that can be transported by a general truck can be, for example, a length of about 6 to 7 m. In addition, in this specification, "large span" and "high height" mean that the length of the wooden shaft member is, for example, about 10 m, which is a length that is impossible or difficult to transport by a general truck. In addition, "multiple wooden shaft members including at least a first wooden shaft member and a second wooden shaft member" means a form consisting of two first wooden shaft members and a second wooden shaft member, as well as a form consisting of three or more wooden shaft members, such as a form consisting of two first wooden shaft members and one second wooden shaft member, or a form consisting of two first wooden shaft members and two second wooden shaft members. In any form, the joint interface between adjacent wooden shaft members can be arranged at a position offset in the axial direction of the overlapping wooden shaft member, so that the joint interface can be reinforced by being straddled by adjacent wooden shaft members.

In this embodiment, the first joining means for joining the split wooden shaft members and the second joining means for joining the first wooden shaft member and the second wooden shaft member may be bolts (including lag screw bolts) or screws.

Another aspect of the wooden overlapping shaft member according to the present invention is characterized in that a dowel is interposed at the overlapping surface to prevent the first wooden shaft member and the second wooden shaft member from shifting relative to each other.

According to this embodiment, by interposing a dowel between the first and second wooden shaft members, it is possible to prevent the two wooden shaft members from shifting relative to each other. Here, examples include a form in which grooves into which ring-shaped dowels are fitted are provided at corresponding positions on the overlapping surfaces of both wooden shaft members, and dowels are fitted into both grooves, or a form in which a rod-shaped or plate-shaped dowel with multiple claws on its surface is pressed and embedded into the overlapping surfaces of both wooden shaft members.

In addition, another aspect of the stacked wooden shaft member according to the present invention is characterized in that the two split wooden shaft members provided in the first wooden shaft member and the second wooden shaft member are the first split wooden shaft member and the second split wooden shaft member of different lengths.

According to this embodiment, the first and second wooden shaft members are both formed from first and second divided wooden shaft members of different lengths, so that a wooden overlapping shaft member can be formed with a minimum number of divided wooden shaft members (two types) while arranging the joint interfaces of the first and second wooden shaft members in offset positions, thereby reducing manufacturing costs and improving manufacturability.

In addition, another aspect of the wooden overlapping shaft member according to the present invention is a wooden overlapping beam having a length L,
The present invention is characterized in that all of the multiple joint interfaces are located within a range of L/4 to L/3 from the beam end of the wooden laminate beam.

According to this embodiment, the joint interface between the first and second wooden shaft members is a wooden overlap beam that is within a range of L/4 to L/3 from the beam end of the wooden overlap beam, so that the joint interface between the wooden shaft members can be set at a position that avoids the center of the beam span, where the bending moment is generally dominant, whether the beam end is pin-connected or rigidly connected. Furthermore, when the length of the wooden overlap beam member is L, the length of one split wooden shaft member is set to a range of 3L/4 to 2L/3, and the length of the other split wooden shaft member is set to the remaining range of L/4 to L/3 (with this configuration, the joint interface is within a range of L/4 to L/3 from the beam end of the wooden overlap beam), so that both split wooden shaft members can be set to a length that can be transported by a general truck.

In addition, another aspect of the wooden stacked shaft member according to the present invention is a wooden stacked pillar having a length L,
The present invention is characterized in that all of the multiple joint interfaces are located within a range of L/4 to L/3 from the end of the wooden layered column.

According to this aspect, the joint interface between the first and second wooden shaft members is within a range of L/4 to L/3 from the end of the wooden stacked column, so that the joint interface between the wooden shaft members can be set at a position that avoids the center of the column height where the bending moment is generally dominant when the upper and lower ends of the column are pin-connected. Furthermore, when the length of the wooden stacked shaft member is L, the length of one split wooden shaft member is set in the range of 3L/4 to 2L/3, and the length of the other split wooden shaft member is set in the remaining range of L/4 to L/3, so that both split wooden shaft members can be set to lengths that can be transported by a general truck.

As can be understood from the above explanation, the wooden overlapping shaft member of the present invention can provide a wooden overlapping shaft member that is excellent in transportability for wooden shaft members such as large-span wooden beams and tall wooden columns, and does not reduce the design freedom in the vertical structural plane of a building.

FIG. 2 is a perspective view showing an example of a wooden stacking shaft member according to the first embodiment. 10 is a diagram illustrating an example of a dowel interposed on the mating surface between the first wood shaft member and the second wood shaft member. FIG. 13A to 13C are diagrams illustrating other examples of dowels interposed on the mating surfaces of the first and second wooden shaft members. FIG. 1 is a schematic diagram illustrating a conventional wooden overlap beam. FIG. 11 is a perspective view showing an example of a wooden stacking shaft member according to a second embodiment. FIG. 1 is a schematic diagram illustrating a conventional wooden stacked pillar.

The wooden stacking shaft member according to each embodiment will be described below with reference to the attached drawings. Note that in this specification and the drawings, substantially identical components may be designated by the same reference numerals to avoid redundant description.

[Wood stacked shaft member according to the first embodiment]
First, a wooden overlapping shaft member according to the first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view showing an example of a wooden overlapping shaft member according to the first embodiment. Fig. 2A and Fig. 2B are diagrams for explaining an example of a dowel interposed between the overlapping surfaces of the first wooden shaft member and the second wooden shaft member.

The illustrated wooden overlapping shaft member 70A is a wooden overlapping beam that constitutes the vertical structural surface of a building. The wooden overlapping beam 70A is formed by overlapping the overlapping surface 30a of the first wooden shaft member 30A and the overlapping surface 30b of the second wooden shaft member 30B, and integrating them with a plurality of bolts and nuts 50 (an example of a second joining means). The axial length L of the wooden overlapping beam 70A is long, for example, about 10 m, and is suitable for a vertical structural surface with a large span width. Note that the illustrated wooden overlapping shaft member 70 is formed of two first wooden shaft members 30A and a second wooden shaft member 30B, but it may be formed, for example, by sandwiching one second wooden shaft member 30B between two first wooden shaft members 30A, or by arranging two first wooden shaft members 30A and two second wooden shaft members 30B alternately.

The first wood shaft member 30A is formed by a first divided wood shaft member 10 having a long, thin hexahedral plate shape with a length of 2L/3 to 3L/4, and a second divided wood shaft member 20 having a long, thin hexahedral plate shape with a length of L/4 to L/3. A metal groove 17 is opened in the joint end face 16 at the axial end of the first divided wood shaft member 10, and a metal groove 27 is opened in the joint end face 26 at the axial end of the second divided wood shaft member 20. A joint interface 31 is formed by abutting both joint end faces 16, 26.

The first divided wooden shaft member 10 and the second divided wooden shaft member 20 may both be made of solid wood or may be made of a laminated material consisting of multiple laminated laminas.

Then, the metal grooves 17, 27 are aligned at the joint interface 31, and a metal plate 41 with bolt holes (not shown) is inserted into the aligned metal grooves 17, 27. For example, the metal plate 41 has two rows of bolt holes, three in each row, for a total of six.

The first split wooden shaft member 10 has two opposing wide sides 11 and four end faces 12, with multiple bolt holes 13 penetrating the opposing wide sides 11, and the wide side 11 facing the outside has countersunk grooves 14 that communicate with the bolt holes 13.

The second split wood shaft member 20, on the other hand, has two opposing wide faces 21 and four end faces 22, with multiple bolt holes 23 penetrating the opposing wide faces 21, and the wide face 21 facing the outside has countersunk grooves 24 that communicate with the bolt holes 23.

The joint interface 31 of the first wood shaft member 30A is located at a distance of L/4 to L/3 from the beam end of the first wood shaft member 30A (one beam end 71a of the overlapping wood beam 70A), and similarly, the joint interface 31 of the second wood shaft member 30B is located at a distance of L/4 to L/3 from the beam end of the second wood shaft member 30B (the other beam end 71b of the overlapping wood beam 70A). In the overlapping wood beam 70A, the first wood shaft member 30A and the second wood shaft member 30B are overlapped so that the joint interfaces 31 of both are offset.

In addition, in this overlapping, the wide surface of the first wood shaft member 30A and the wide surface of the second wood shaft member 30B are overlapped so that they form overlapping surfaces 30a, 30b. That is, as shown in FIG. 1, in the axially orthogonal cross sections of the first wood shaft member 30A and the second wood shaft member 30B, the wide surfaces extending in the minor axis direction of both are abutted against each other as overlapping surfaces 30a, 30b.

In this way, when the mating surface 30a of the first wooden shaft member 30A and the mating surface 30b of the second wooden shaft member 30B are overlapped, the multiple bolt holes 13, 23 of both members are aligned with each other to form multiple communication holes, and bolts are inserted into each communication hole.

At the location where the metal plate 41 is inserted, the bolt holes 13, 23 of the first wood shaft member 30A and the bolt holes 13, 23 of the second wood shaft member 30B are aligned with each bolt hole of the metal plate 41 to form a communicating hole, and a bolt is inserted into this communicating hole to form the first joining means 40 with the metal plate 41 and the bolt nut 42. Note that, instead of bolts and nuts, lag screws, bolts, screws, etc. may be used as components of the first joining means 40 and the second joining means 50.

The first split wood shaft member 10 and the second split wood shaft member 20 are joined by the first joining means 40 to form the first wood shaft member 30A and the second wood shaft member 30B. At the same time, the second wood shaft member 30B is joined to the first wood shaft member 30A on the side of the joint interface 31 so as to straddle the joint interface 31. On the other hand, the first wood shaft member 30A is joined to the second wood shaft member 30B on the side of the joint interface 31 so as to straddle the joint interface 31.

In addition, the first wood shaft member 30A and the second wood shaft member 30B are provided with a plurality of bolt holes 13, 23 that are aligned with each other to form a plurality of communication holes, and bolts are inserted into the plurality of communication holes and the nuts are tightened, thereby fastening the first wood shaft member 30A and the second wood shaft member 30B with a plurality of bolts and nuts 50.

According to the laminated wooden beam 70A, the first wooden shaft member 30A and the second wooden shaft member 30B are formed by two split wooden shaft members 10, 20 joined to each other via the joint interface 31, and the joint interfaces 31 of each wooden shaft member 30 are arranged at positions offset in the axial direction to join the two wooden shaft members 30. Therefore, even if the length L of the laminated wooden beam 70A is long, for example about 10 m, it can be transported by a general truck in a state where it is divided into split wooden shaft members 10, 20 of about 3 m to 7 m.

In addition, by joining the two wooden shaft members 30 formed by the two split wooden shaft members 10, 20 with the joint interface 31 of the two wooden shaft members 30 offset in the axial direction of the wooden overlapping beam 70A, the joint interface 31 of one wooden shaft member 30 is reinforced by the other wooden shaft member 30 straddling it, and the strength around the joint interface 31 can be increased without providing special reinforcement to the joint interface 31 of the wooden shaft members 30.

In addition, since the joint interfaces 31 of the first wooden shaft member 30A and the second wooden shaft member 30B are both within a range of L/4 to L/3 from the beam ends 71a, 71b of the wooden overlap beam 70A, each joint interface 31 can be set at a position that avoids the center of the beam span, where the bending moment is generally dominant, whether the beam ends 71a, 71b are pin-connected or rigid-connected.

Furthermore, the side surfaces of the first wooden shaft member 30A and the second wooden shaft member 30B that extend in the weak axis direction in the axially orthogonal cross section are abutted against each other as overlapping surfaces 30a, 30b, so that when the wooden overlapping beam 70A is applied to the vertical structural plane of a building, there is no risk of narrowing the internal space of the vertical structural plane and reducing the design freedom.

For example, in conventional stacked beams, as shown in Figure 3, in order to increase the bending strength, for example, the side surfaces extending in the direction of increasing the beam height, i.e., in the strong axis direction in the cross section perpendicular to the axis of the shaft member, are abutted against each other as overlapping surfaces. Therefore, as shown in Figure 3, the end surface 22 of the first wood shaft member 30A (the second divided wood shaft member 20 constituting it) and the end surface 12 of the second wood shaft member 30B (the first divided wood shaft member 10 constituting it) are abutted against each other as overlapping surfaces.

Increasing the beam depth in this way improves the bending strength against the load P acting on the beam, so conventional stacked beams are generally stacked as shown in the example shown.

In contrast, the wooden overlap beam 70A shown in Figure 1 does not overlap two wooden shaft members 30 in the direction that increases the beam height, but overlaps the wide surfaces of both members as overlapping surfaces 30a, 30b, which is a completely different overlapping method from conventional overlap beams. Therefore, while the bending strength against the bending moment caused by the load P acting on the beam as shown in Figure 1 is not increased compared to the conventional overlap beam shown in Figure 3, the overall beam height is not increased, so that when applied to the vertical structural plane of a building, it is a wooden overlap beam that does not narrow the internal space of the vertical structural plane and reduce the design freedom.

As shown in FIG. 2A or 2B, a dowel is provided on the mating surfaces of both wooden shaft members 30 to prevent the two wooden shaft members 30 from shifting relative to each other.

In the example shown in Figure 2A, endless dowel grooves 25, 15 are opened at corresponding positions on the overlapping surface 30a of one wooden shaft member 30A and the overlapping surface 30b of the other wooden shaft member 30B. The dowel 60A used is a metal dowel having a complementary linear shape to these endless dowel grooves 25, 15. For example, after fitting a part of the dowel 60A into the dowel groove 15 of one wooden shaft member 30B in the X1 direction, the dowel groove 25 of the other wooden shaft member 30A is transferred in the X2 direction so that the other part of the dowel 60A is fitted into it, so that the annular dowel 60A is interposed between the overlapping surfaces 30a, 30b of the two wooden shaft members 30A, 30B, and the relative displacement of the two wooden shaft members 30A, 30B can be prevented. In this way, two wooden shaft members 30A, 30B are stacked together with multiple dowels 60A in between, and then bolts are inserted into the multiple communication holes that are formed, and the two wooden shaft members 30A, 30B are joined together with bolt nuts 50 to form a stacked wooden beam 70A.

On the other hand, in the example shown in FIG. 2B, a dowel 60B is placed between the overlapping surface 30a of one wooden shaft member 30A and the overlapping surface 30b of the other wooden shaft member 30B, and the two wooden shaft members 30A, 30B are transferred in the X3 direction so as to sandwich the dowel 60B, thereby interposing the dowel 60B between the wooden shaft members 30A, 30B. Here, the dowel 60B is a dowel with many claws 62 protruding from the side of a metal rod-shaped body 61, and when the dowel 60B is sandwiched between the wooden shaft members 30A, 30B, the many claws 62 pierce both wooden shaft members 30A, 30B, thereby preventing the wooden shaft members 30A, 30B from shifting relative to each other via the dowel 60B.

The dowel 60B has a rod-shaped body 61 with multiple claws 62, but it may also have a plate-shaped body with multiple claws on its surface, for example.

[Wood stacked shaft member according to the second embodiment]
Next, a wooden layered shaft member according to a second embodiment will be described with reference to Fig. 4. Here, Fig. 4 is a perspective view showing an example of the wooden layered shaft member according to the second embodiment.

The illustrated wooden layered shaft member 70B is a wooden layered column that constitutes the vertical structural surface of a building. The basic structure of the wooden layered column 70B is the same as that of the wooden layered beam 70A, and the wooden layered beam 70A already described is applied as the wooden layered column 70B. The axial length L of the wooden layered column 70B is also long, for example, about 10 m, making it suitable for high vertical structural surfaces and applicable, for example, as a wind-resistant column.

Like the wooden overlap beam 70A, the wooden overlap column 70B also has the effect of being easy to transport and having increased strength around the joint interface 31. In addition, since the joint interfaces 31 of the first wooden shaft member 30A and the second wooden shaft member 30B are both within a range of L/4 to L/3 from the column ends 71a, 71b of the wooden overlap column 70B, each joint interface 31 can be set at a position that avoids the center of the column span, where the bending moment is generally dominant in pin connections.

In addition, the side surfaces of the first wooden shaft member 30A and the second wooden shaft member 30B that extend in the minor axis direction in the axially orthogonal cross section are abutted against each other as overlapping surfaces 30a, 30b, so that when the wooden overlapping column 70B is applied to the vertical structural plane of a building, there is no risk of narrowing the internal space of the vertical structural plane and reducing the design freedom.

For example, in a conventional stacked column, as shown in Figure 5, in order to increase its bending strength, for example, the side surfaces extending in the direction that increases the width of the column in the direction of action of the horizontal force H acting, i.e., the strong axis direction in the cross section perpendicular to the axis of the shaft members, are abutted against each other as overlapping surfaces. Therefore, as shown in Figure 5, the end surface 22 of the first wood shaft member 30A (the second divided wood shaft member 20 constituting it) and the end surface 12 of the second wood shaft member 30B (the first divided wood shaft member 10 constituting it) are abutted against each other as overlapping surfaces.

In this way, by increasing the width of the column in the direction in which the horizontal force H acts, the bending strength against the bending moment generated by the horizontal force H acting on the column is improved, so conventional stacked columns are generally stacked as shown in the example shown.

In contrast, the wooden stacked column 70B shown in Figure 4 does not overlap two wooden shaft members 30 so as to lengthen the width of the column in the direction in which the horizontal force H acts, but rather overlaps the wide surfaces of both members as overlapping surfaces 30a, 30b, which is a completely different overlapping method from conventional stacked columns. Therefore, as shown in Figure 4, the bending resistance against the bending moment caused by the horizontal force H acting on the column is not increased compared to the conventional stacked column shown in Figure 5, but since the column width in the horizontal direction is not increased, it is a wooden stacked column that does not narrow the internal space of the vertical structural plane and does not reduce the design freedom when applied to the vertical structural plane of a building.

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: First split wooden shaft member (split wooden shaft member)
11: Wide surface 12: Small end surface 13: Bolt hole 14: Countersink groove 15: Dowel groove 16: Joint end surface 17: Metal groove 20: Second split wooden shaft member (split wooden shaft member)
21: wide surface 22: small end surface 23: bolt hole 24: counterbore groove 25: dowel groove 26: joint end surface 27: metal groove 30: wood shaft member 30A: first wood shaft member (wood shaft member)
30a: overlapping surface 30B: second wood shaft member (wood shaft member)
30b: overlapping surface 40: first joining means 41: metal plate 42: bolt nut 50: second joining means (bolt nut)
60A, 60B: Dowel 61: Rod-shaped body 62: Nail 70: Wooden overlapping shaft member 70A: Wooden overlapping beam (wooden overlapping shaft member)
70B: Wooden stacked pillar (wooden stacked shaft member)
71a, 71b: Beam end, column end

Claims (4)

A wooden overlapping shaft member in which a plurality of wooden shaft members including at least a first wooden shaft member and a second wooden shaft member are overlapped and integrated,
Each of the first and second wood shaft members includes at least two split wood shaft members, and the joint end surfaces of the two split wood shaft members are abutted to form a joint interface. The first and second wood shaft members are formed by joining the two split wood shaft members with a first joining means.
The joint interfaces of the first and second wood shaft members are arranged at positions offset from each other in the axial direction, and the side surfaces of the first and second wood shaft members extending in the minor axis direction in the axially orthogonal cross sections are abutted against each other as overlapping surfaces, and the first and second wood shaft members are joined by a second joining means;
A wooden overlapping shaft member, characterized in that a dowel groove is opened at corresponding positions on the overlapping surfaces of both the first wooden shaft member and the second wooden shaft member, and a dowel having a complementary linear shape to the dowel groove is fitted into the dowel groove to prevent relative displacement between the first wooden shaft member and the second wooden shaft member. The wooden layered shaft member according to claim 1, characterized in that the two split wooden shaft members provided in the first wooden shaft member and the second wooden shaft member are the first split wooden shaft member and the second split wooden shaft member of different lengths. The wooden overlapping shaft member is a wooden overlapping beam having a length L,
The wooden overlapping beam member according to claim 1 or 2 , characterized in that all of the multiple joint interfaces are located within a range of L/4 to L/3 from the beam end of the wooden overlapping beam. The wooden stacked shaft member is a wooden stacked pillar having a length L,
The wooden stacked shaft member according to claim 1 or 2 , characterized in that all of the multiple joint interfaces are located in a range of L/4 to L/3 from the end of the wooden stacked shaft member.

Images