Joint structure between beam and seismic wall

Abstract

To provide a joint structure of a beam and an earthquake-resisting wall capable of appropriately designing a joint member according to stress to be borne.SOLUTION: A center part joint member 30 includes a center part fixing part 31 fixed to an RC beam 10, a center part flat plate part 32 of a flat plate shape extending from the center part fixing part 31 toward a vertical direction, and a center part projecting part 33 projecting from the center part flat plate part 32 toward both directions in a thickness direction of an earthquake resisting wall 20. The center part flat plate part 32 and the center part projecting part 33 are inserted into a central groove part 21 formed in the central part of the upper and lower end parts of the earthquake resisting wall 20 in a state of having a part 52 formed by solidifying a filler having a larger compressive yield strength than woody material therebetween. A drift pin 54 is inserted through a through-hole formed in the earthquake resisting wall 20 and a through-hole formed in a side flat plate part 42 in a state where the side flat plate part 42 is inserted into a side groove part 21 formed in each of both side parts of upper and lower end parts of the earthquake resisting wall 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a joint structure between a beam and a seismic wall.

Background Art

[0002] The need to prevent global warming and to improve forest resources and forestry has been attracting attention. Also, from the perspectives of ESG investment and SDGs, the active use of wood materials is demanded. Therefore, it may be used as a seismic wall in which cross-laminated timber (CLT board), in which plywood boards are stacked so that the fiber directions are orthogonal, is installed in a structure.

[0003] A seismic wall is a structural member that bears the stress generated during an earthquake or the like together with columns and beams that constitute a structure, and prevents deformation and destruction of the structure. It is desirable that the seismic wall is joined to columns and beams to cover the entire structure. However, depending on the floor plan of a building or the like, it is also used as an intermediate wall that is not joined to columns and whose upper and lower ends are fixed to beams. In such a case, the CLT seismic wall and the beam are often joined with a drift pin via a joint metal fitting.

[0004] In Patent Documents 1 and 2, when using a CLT seismic wall as an intermediate wall, joint metal fittings provided on both the left and right sides of the upper and lower ends of the CLT seismic wall and joint metal fittings provided at the central portions of the upper and lower ends are used, and both are joined to the beam with drift pins. Thereby, the joint metal fittings provided on both the left and right sides mainly bear the bending stress (tensile force) acting on the CTL seismic wall, and the joint metal fittings provided at the central portion mainly bear the shear force acting on the CTL seismic wall.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] However, when joining with drift pins, there is a slight clearance between the through-hole of the joining fitting and the drift pin, and this clearance delays the stress transfer from the frame to the shear wall. Therefore, when both joining fittings are joined with drift pins, as in the technologies described in the above-mentioned Patent Documents 1 and 2, the stress transfer through both joining fittings starts to bear stress by the same amount of delay, resulting in the joining fitting bearing both vertical and horizontal stress simultaneously. Consequently, there is a problem in that it is difficult to appropriately design the joining fitting according to the stress it bears.

[0007] In view of the above, the present invention aims to provide a joint structure between a beam and a seismic wall that allows for the appropriate design of the joint members (joint fittings) according to the stress being borne. [Means for solving the problem]

[0008] The beam-to-shear wall joint structure of the present invention is a joint structure between a beam of a frame and a shear wall made of wood material, comprising a central joint member that joins the central part of the upper and lower ends of the shear wall to the beam, and two side joint members that join the beam to the beam on both sides of the upper and lower ends of the shear wall, respectively, the central joint member comprising a central fixing part fixed to the beam, a flat central plate part extending vertically from the central fixing part, and central protruding parts projecting in both directions in the thickness direction of the shear wall from the central plate part, and the side joint members comprising a side fixed to the beam The seismic wall comprises a central fixing portion and a flat plate-shaped side plate portion extending vertically from the side fixing portion and having a plurality of through holes formed therein, with a portion between them made of a solidified filler having a greater compressive strength than the wood material, the central plate portion and the central projection portion are inserted into central grooves formed in the center of the upper and lower ends of the seismic wall, and the side plate portion is inserted into side grooves formed on both sides of the upper and lower ends of the seismic wall, respectively, and drift pins are inserted through through holes formed in the seismic wall and through holes formed in the side plate portion.

[0009] According to the beam-to-shear wall joint structure of the present invention, the shear wall is joined to the beam via a central joint member having a central projection that receives horizontal bearing pressure, and since there is a portion between them where the filler material has solidified, the horizontal stress from the beam is directly transmitted to the shear wall. On the other hand, the vertical stress from the beam is not directly transmitted to the shear wall because slip occurs between the beam and the central joint member. As a result, the horizontal stress from the beam is transmitted to the shear wall from the central joint member even when there is no initial displacement, so the central joint member mainly bears the shear force acting on the shear wall.

[0010] Although the shear wall is also connected to the beam at the side joint members, these are joined with drift pins, and a small gap inevitably exists between the drift pins and the through-holes in the shear wall. Therefore, the stress from the beam is transmitted to the shear wall only after an initial displacement has occurred. As a result, the side joint members mainly bear the bending stress acting on the shear wall. Thus, it is possible to appropriately design the central joint members and side joint members according to the stress they bear.

[0011] In the beam-and-shear wall joint structure of the present invention, the shear wall is made of CLT material, and it is preferable that the fiber direction of the sawn boards constituting the CLT material is vertical and horizontal.

[0012] In this case, the vertical component of the stress transmitted from the beam to the shear wall can be suitably borne by the sawn board with the fiber direction perpendicular, and the horizontal component can be suitably borne by the sawn board with the fiber direction horizontal.

[0013] Furthermore, in the beam-and-shear wall joint structure of the present invention, the filling material is preferably a cement-based solidifying material.

[0014] In this case, it becomes possible to easily obtain a filling material with greater compressive strength than the wood material that makes up the seismic wall.

[0015] Furthermore, in the beam-to-shear wall joint structure of the present invention, it is preferable that the beam has a portion made of wood material, and that a portion made of heat sink material is provided between the portion and the shear wall.

[0016] In this case, a heat sink is formed by the heat sink material, making it difficult for the heat generated when the seismic wall burns in a fire to be transferred to the wooden part of the beam. The heat sink material is, for example, solidified mortar, but other materials may also be used. [Brief explanation of the drawing]

[0017] [Figure 1]Schematic front view of the joint structure between a beam and a seismic wall according to the first embodiment of the present invention. [Figure 2] Schematic cross-sectional view taken along line II-II of FIG. 1. [Figure 3] Schematic cross-sectional view taken along line III-III of FIG. 1. [Figure 4] Schematic cross-sectional view taken along line IV-IV of FIG. 3. [Figure 5] Schematic front view of the joint structure between a beam and a seismic wall according to the second embodiment of the present invention. [Figure 6] Schematic cross-sectional view taken along line V-V of FIG. 5. [Figure 7] Schematic cross-sectional view taken along line IIV-IIV of FIG. 6.

Embodiments for Carrying Out the Invention

[0018] The joint structure 100 between a beam and a seismic wall according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. Note that all the drawings are for schematically explaining the embodiments of the present invention, and the dimensions are deformed.

[0019] The joint structure 100 between a beam and a seismic wall according to this embodiment is a structure in which a seismic wall 20 is provided in an RC structure. Here, the seismic wall 20 is joined only to the RC beam (RC beam) 10. However, the seismic wall 20 may be joined to the RC columns of the structure.

[0020] The seismic wall 20 is a seismic wall made of a wood material, and here, it is formed of a cross-laminated timber (CLT board). However, the seismic wall 20 is not limited to being made of a CLT board, and it may be made of parallel laminated timber, laminated veneer lumber (LVL lumber), plywood, or the like.

[0021] In a front view, the upper and lower end portions of the seismic wall 20 are joined to the RC beam 10 via joining members 30 and 40. The joining members 30 and 40 are composed of a central joining member 30 and two side joining members 40.

[0022] In a front view, the central connecting member 30 connects the central part of the upper end of the seismic wall 20 to the RC beam 10 located above it. In a front view, the central connecting member 30 also connects the central part of the lower end of the seismic wall 20 to the RC beam 10 located below it.

[0023] The central joint member 30 comprises a central fixing portion 31 fixed to the RC beam 10, a flat central plate portion 32 extending from the central fixing portion 31 in the direction of the wall surface (vertical direction) of the seismic wall 20, and central protruding portions 33 projecting from the central plate portion 32 in both directions (front and back directions) of the thickness direction of the seismic wall 20.

[0024] Here, the central fixing portion 31 consists of a rectangular steel plate with multiple through holes. The central flat plate portion 32 consists of a rectangular steel plate that extends upward or downward toward the seismic wall 20 to which it is joined, and one of its vertical ends is fixed to the central part of the central fixing portion 31 by welding or the like.

[0025] The central projection 33 consists of two rectangular steel plates that protrude in both the front and rear directions, and is fixed to the left and right end faces of the central flat plate portion 32 by welding or the like. As a result, the central flat plate portion 32 and the central projection 33 as a whole have an H-shape or I-shape when viewed from above. In this case, the central projection 33 is fixed to the central fixing portion 31, and the left and right end faces of the central fixing portion 31 and their side end faces are flush, but this is not limited to this.

[0026] Furthermore, the central flat plate portion 32 and the central protruding portion 33 may be integrated and made of H-beams, I-beams, or the like. The central protruding portion 33 may also be fixed to the center of both the front and rear surfaces of the central flat plate portion 32 by welding or the like, so that the central flat plate portion 32 and the central protruding portion 33 as a whole have a cross shape when viewed from above. Moreover, the central flat plate portion 32 and the central protruding portion 33 as a whole may have a king-shaped shape when viewed from above.

[0027] The central connecting member 30 is fixed to the upper and lower surfaces of the RC beam 10 by inserting anchor bolts 51 through through holes formed in the RC beam 10 so as to penetrate vertically, and through holes formed in the central fixing part 31.

[0028] Furthermore, a central groove (slit) 21 is formed in the central part of the upper and lower ends of the seismic wall 20, following the outer shape of the central flat plate portion 32 and central protrusion portion 33 of the central joint member 30. For example, if the outer shape of the central flat plate portion 32 and central protrusion portion 33 of the central joint member 30 is I-shaped when viewed from above, the central groove 21 is formed in the seismic wall 20 so that there is a small gap between this I shape and the groove. The shape of this central groove 21 is preferably I-shaped, but it may also be a shape that includes an I-shape, such as a rectangle.

[0029] The seismic wall 20 has a central flat section 32 and a central protruding section 33 inserted into the central groove section 21, with a solidified filler section 52 between them. The filler has a greater compressive strength than the wood material that makes up the seismic wall 20, and is a cement-based solidifying material such as grout or non-shrink mortar.

[0030] For example, at both the upper and lower ends of the seismic wall 20, when the central flat plate portion 32 and the central protruding portion 33 are inserted into the central groove portion 21 at the construction site, filler material can be poured into the gaps created, and the gaps can be filled with the filler material and held in place until the filler material hardens. In this way, the upper and lower ends of the seismic wall 20 are fixed to the intermediate joint member 30 via the portions 52 made of hardened filler material. Alternatively, the lower end of the seismic wall 20 may be fixed in advance at a factory or elsewhere, and the upper end may be fixed by filling with filler material at the construction site. It is preferable to waterproof the inner surface of the central groove portion 21 so that the seismic wall 20 does not absorb moisture from the filler material when filling the central groove portion 21.

[0031] The side joint member 40 comprises a side fixing portion 41 that is fixed to the RC beam 10, and a flat side plate portion 42 that extends from the side fixing portion 41 in the direction of the wall surface (vertical direction) of the seismic wall 20.

[0032] Here, the side fixing portion 41 consists of a rectangular steel plate with multiple through holes. The side flat plate portion 42 consists of a rectangular steel plate extending upward or downward toward the seismic wall 20 to which it is joined, and one of its vertical ends is fixed to the center of the side fixing portion 41 by welding or the like. The side flat plate portion 42 has numerous through holes.

[0033] The side connecting members 40 are fixed to the upper and lower surfaces of the RC beam 10, respectively, by inserting anchor bolts 53 through through holes formed in the RC beam 10 so as to penetrate vertically, and through holes formed in the side flat plate portion 42.

[0034] Furthermore, side grooves (slits) 22 are formed on both the left and right sides of the upper and lower ends of the seismic wall 20, following the outer shape of the side flat plate portion 42 of the side joining member 40. In addition, numerous through holes are formed in the thickness direction at the upper and lower ends of the seismic wall 20, corresponding to the positions of the through holes formed in the side flat plate portion 42.

[0035] A side plate portion 42 is inserted into the side groove portion 22 of the seismic wall 20, and numerous drift pins 54 are inserted through through holes formed in the seismic wall 20 and through holes formed in the side plate portion 42.

[0036] Thus, the seismic wall 20 is joined to the RC beam 10 via a central joint member 30 having a central protrusion 33 that receives horizontal bearing pressure, and the gap between the central joint member 30 and the central groove 31 is filled by a portion 52 made of solidified filler material, so that in the initial stage of loading, the portion 52 made of solidified filler material bears the horizontal stress from the RC beam 10, and the side joint member 40 bears the vertical stress from the RC beam 10.

[0037] As a result, the horizontal stress from the RC beam 10 is transmitted from the central connecting member 30 to the shear wall 20 even when there is no initial displacement, so the central connecting member 30 mainly bears the shear force acting on the shear wall 20.

[0038] The seismic wall 20 is also connected to the RC beam 10 at the side connecting members 40, but these are connected by drift pins 54, and there is inevitably a small gap between the drift pins 54 and the through holes in the seismic wall 20, so the stress from the RC beam 10 is transmitted to the seismic wall 20 only after an initial displacement has occurred. As a result, the side connecting members 40 mainly bear the bending stress acting on the seismic wall 20. The bending stress is a stress that acts in a direction that rotates around the central connecting member 30 and is accompanied by a large displacement in the vertical direction, so the drift pins 54 function effectively. Therefore, it is possible to appropriately design the central connecting member 30 and the side connecting members 40 according to the stress they bear.

[0039] Furthermore, it is preferable that the seismic wall 20 be installed by stacking multiple layers of CLT material with two types of fiber orientations, vertical and horizontal, so that it is effective against stress in both directions.

[0040] Furthermore, if the stress borne by the seismic wall 20 is large, and all connections between the seismic wall 20 and the connecting members are made with drift pins, the connecting members may become large in order to secure the required number of drift pins, potentially making it impossible to place the connecting members. However, in this embodiment, the connection between the seismic wall 20 and the central connecting member 30 is made via a portion 52 made of solidified filler material, which makes it possible to suppress the size of the central connecting member 30.

[0041] Next, the beam-and-shear wall joint structure 200 according to the second embodiment of the present invention will be described with reference to Figures 5 to 7. Note that the schematic cross-sectional view along line II-II in Figure 5 is the same as the schematic cross-sectional view along line II-II in Figure 1 of the first embodiment, Figure 2.

[0042] The connection structure 200 with the seismic wall according to this embodiment is a connection structure between the RC beam 70 and the seismic wall 20 via a wooden beam (wooden beam) 60. However, the seismic wall 20 may also be connected to columns of the frame, such as RC columns. The wooden beam 60 corresponds to the portion of the beam made of wood material according to the present invention.

[0043] The wooden beam 60 is fixed to the underside of the RC beam 70 using fasteners such as bolts (not shown), and a surface layer 62 made of wood is present on its outer surface via a fire-resistant coating 61 such as reinforced gypsum board.

[0044] In a front view, the seismic wall 20 is joined at its upper end to the wooden beam 60 or RC beam 70 via connecting members 80 and 40, and at its lower end to the RC beam 70 via connecting members 30 and 40. The connecting members 80, 30 and 40 consist of two types of central connecting members 80 and 30 and one type of side connecting member 40.

[0045] The first central connecting member 80 connects the central part of the upper end of the seismic wall 20 to the wooden beam 60 located above it, in a front view. The second central connecting member 30 connects the central part of the lower end of the seismic wall 20 to the reinforced concrete beam 70 located below it, in a front view.

[0046] The second central joint member 30 is configured identically to the central joint member 30 described above. The first central joint member 80 is configured similarly to the central joint member 30 described above, but here the central fixing portion 81 is extended in both the left and right directions, and the number of through holes is also increased. The side joint member 40 is configured identically to the side joint member 40 described above.

[0047] A recess 63 is formed on the underside of the wooden beam 60, and the first central joint member 80 is fixed to the underside of the wooden beam 60 by embedding fasteners 91, such as structural screws (panel lead steel, etc.), into the wooden beam 60, through holes formed in the central fixing part 81, so that the central fixing part 81 is pressed against the upper surface of the recess 63. A portion 92 made of heat sink material exists in the remaining space of the recess 63.

[0048] A recess 71 is formed on the upper surface of the RC beam 70, and the second central joint member 30 is fixed to the upper surface of the RC beam 70 by inserting anchor bolts 72, which are embedded in the RC beam 70, through holes formed in the central fixing portion 31, so that the central fixing portion 31 is pressed against the bottom surface of the recess 71. The remaining space of the recess 71 contains a portion 93 made of heat sink material.

[0049] Furthermore, at the upper and lower ends of the seismic wall 20, a central groove (slit) 21 is formed in the central part, following the outer shape of the central flat portion 82, 32 and the central protruding portion 83, 33 of the first and second central joint members 80, 30, respectively.

[0050] The central groove 21 of the seismic wall 20 is fitted with central flat sections 82, 32 and central protruding sections 83, 33, with a solidified filler section 52 between them. When filling the central groove 21 with filler, it is preferable to waterproof the inner surface of the central groove 21 so that the seismic wall 20 does not absorb moisture from the filler.

[0051] The side connecting members 40 are fixed to the upper surface of the RC beam 70 and the lower surface of the timber beam 60, respectively, by inserting anchor bolts 94 through through holes formed to penetrate vertically between two recesses 73 formed on the upper surface of the RC beam 70 and two recesses 64 formed on the lower surface of the timber beam 60, and through holes formed in the side fixing part 41.

[0052] Furthermore, a portion 93 made of heat sink material exists in the remaining space of the recess 71 in the RC beam 70. Similarly, a portion 92 made of heat sink material exists in the remaining space of the recess 63 in the wooden beam 60. In this way, a heat sink is formed by portions 92 and 93 made of heat sink material, making it difficult for heat generated when the seismic wall burns in a fire to be transferred to the wooden beam 60. The heat sink material is, for example, solidified mortar, but other materials may also be used.

[0053] Furthermore, compression prevention rods 97 made of steel rods are inserted into through holes formed in the RC beam 70 and the wooden beam 60 so as to penetrate them vertically, and the upper and lower end faces are in contact with the side fixing portion 41 of the side joining member 40.

[0054] Furthermore, side grooves (slits) 22 are formed on both the left and right sides of the upper and lower ends of the seismic wall 20, following the outer shape of the side flat plate portion 42 of the side joining member 40. In addition, numerous through holes are formed in the thickness direction at the upper and lower ends of the seismic wall 20, corresponding to the positions of the through holes formed in the side flat plate portion 42.

[0055] A side plate portion 42 is inserted into the side groove portion 22 of the seismic wall 20, and numerous drift pins 98 are inserted through through holes formed in the seismic wall 20 and through holes formed in the side plate portion 42.

[0056] Thus, in the second embodiment, as in the first embodiment described above, the central connecting members 80 and 30 mainly bear the shear force acting on the seismic wall 20. On the other hand, the side connecting member 40 mainly bears the bending force acting on the seismic wall 20. Therefore, it is possible to appropriately design the central connecting members 80 and 30 and the side connecting member 40 according to the stress they bear.

[0057] It should be noted that the present invention is not limited to the beam-and-shear wall joint structures 100,200 specifically described in the embodiments above, and can be modified as appropriate within the scope of the claims. For example, the beam may be made of steel or the like. [Explanation of Symbols]

[0058] 10,70...RC beam (beam), 20...Seismic wall, 30...Central joint member, second central joint member, joint member, 21...Central groove, 22...Side groove, 31...Central fixing part, 32...Central flat plate, 33...Central protrusion, 40...Side joint member, joint member, 41...Side fixing part, 42...Side flat plate, 51,53...Anchor bolt, 52...Part made of solidified filler (part made of solidified filler), 54...Drift pin, 60...Wooden beam (part made of wood material of the beam), 61...Fireproof coating, 62...Surface layer, 63,64...Depression, 71,73...Depression, 72...Anchor bolt, 80...First central joint member, joint member, 81...Central fixing part, 82...Central flat section, 83...Central protruding section, 91...Fastener, 92,93...Parts made of heat sink material, 94...Anchor bolt, 97...Compression prevention rod, 98...Drift pin, 100,200...Joining structure between beam and seismic wall.

Claims

1. A joint structure between a structural beam and a seismic wall made of wood material, A central joining member that connects the central part of the upper and lower ends of the seismic wall to the beam, The shear wall has two side joining members that connect the upper and lower ends of each side to the beam, The central joint member comprises a central fixing portion fixed to the beam, a flat central plate portion extending vertically from the central fixing portion, and central protruding portions projecting from the central plate portion in both directions in the thickness direction of the seismic wall. The side joint member comprises a side fixing portion fixed to the beam and a flat side plate portion extending vertically from the side fixing portion and having a plurality of through holes formed therein. The central flat portion and the central protruding portion are inserted into the central groove formed in the center of the upper and lower ends of the seismic wall, with a portion in between which a filler having greater compressive strength than the aforementioned wood material has been solidified. A joint structure between a beam and a seismic wall, characterized in that the side flat plate portion is inserted into side grooves formed on both sides of the upper and lower ends of the seismic wall, and drift pins are inserted through through holes formed in the seismic wall and through holes formed in the side flat plate portion.

2. The aforementioned seismic wall is made of CLT material. The beam-and-shear wall joint structure according to claim 1, characterized in that the fiber direction of the sawn slab constituting the CLT material is in the vertical and horizontal directions.

3. The joint structure of a beam and a seismic wall according to claim 1, characterized in that the filler is a cement-based solidifying agent.

4. The beam has a portion made of wood material, The beam-to-shear wall joint structure according to claim 1, characterized in that a portion made of heat sink material is provided between the aforementioned portion and the shear wall.

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