Beam end joint structure

Abstract

To make the joint condition of the beam end match well with the structural calculation model, and suppress the splitting failure of wooden beams.SOLUTION: The end of a wooden beam 1 having a rectangular cross section is joined to a steel beam 2, which is a supporting structural member, via a joining plate 3 fixed to the steel beam. The joining plate is inserted into a vertical slit provided on the end face of the wooden beam, and the wooden beam and the joining plate are joined by drift pins 5 inserted into a plurality of pin holes penetrating horizontally from the side of the wooden beam and a plurality of through holes provided at positions corresponding to the pin holes of the joining plate. The pin holes are arranged at a predetermined distance from the lower end of the wooden beam to the lowest pin hole and are arranged toward the bottom of the beam height, and one or a plurality of through holes located close to each other among the plurality of through holes provided in the joining plate are circular holes 3a, and the other through holes 3b are long holes with their major axes in the horizontal direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a beam end joint structure in which the end of a beam made of wood is joined to a supporting structural member for support. [Background technology]

[0002] In large-scale or medium-scale wooden buildings, large-section wooden materials are often used as beams. In addition, composite structures of wooden materials and steel frames, composite structures of wooden materials and concrete members, etc. are sometimes adopted, and it becomes necessary to join large-section wooden beams to other structural members, such as beams and columns that are wooden materials, steel frames, reinforced concrete members, or steel-reinforced concrete members.

[0003] Generally, structures for joining a wooden beam to another structural member are disclosed in, for example, Patent Document 1 and Patent Document 2. In these structures, a beam support metal fitting is fixed to a supporting structural member to which the beam end is joined, and the beam end is joined to the supporting structural member via the beam support metal fitting. The beam support metal fitting has a steel plate part having a vertical surface protruding from the supporting structural member, and the steel plate part is inserted into a slit provided on the end face of the wooden beam. Then, the beam support metal fitting and the beam are joined by inserting a drift pin through a pin hole provided horizontally from the side of the wooden beam and a through hole provided on the steel plate part. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 10-231562 [Patent Document 1] Patent Publication No. 2008-215057 Summary of the Invention [Problem to be solved by the invention]

[0005] However, as the cross section of the beam becomes larger and the load on the beam increases, the shear force acting on the beam end becomes larger, and the number of drift pins increases and they are arranged in the vertical direction. As the number of drift pins increases, the rotational displacement of the beam end is restrained by the supporting structural member that supports the beam end, and the bending moment acting on the beam end becomes larger. If the connection between such a beam end and the supporting structural member is assumed to be a pin connection in structural calculations, the deviation from the actual structure becomes large. In addition, a structure connected to a beam support metal by multiple drift pins is not a completely rigid connection, and some relative displacement occurs in the rotational direction, so even if the beam end is rigidly connected in structural calculations, there will be a difference from the actual structure.

[0006] On the other hand, when a beam is joined to another supporting structural member, the position is generally set based on the top surface, and the mounting position of metal fittings 62 for joining a beam made of wooden material is also set based on the position of the top surface, as shown in Figure 8. For this reason, the positions of metal fittings 62 and drift pins 63 supporting beam 61 may be biased upward in the beam height. If the drift pins 63 are biased upward, the shear force acting on the beam end will be supported by the upper part of the beam height. For this reason, cracks 64 are likely to occur in the wooden material at the beam end below the position where the drift pins 63 are arranged, as shown in Figure 8.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide a beam end joint structure that can ensure good conformity of the beam end joint state with a structural calculation model and suppress splitting failure of beams made of wood. [Means for solving the problem]

[0008] In order to solve the above problem, the invention of claim 1 provides a beam end joining structure in which an end of a beam made of wood and having a rectangular cross-section is joined to a supporting structural member via a joining plate fixed to the supporting structural member for support, the joining plate having a vertical surface protruding in the axial direction of the beam, the joining plate being inserted into a vertical slit provided in the end face of the beam, the beam and the joining plate being joined by drift pins inserted into a plurality of pin holes penetrating horizontally from the side of the beam and a plurality of through holes provided in the joining plate at positions corresponding to the pin holes, the pin holes maintain a predetermined distance from the lower end of the beam to the lowest pin hole and are arranged toward the bottom of the beam height, and one or a plurality of through holes located in close proximity to one another among the plurality of through holes provided in the joining plate are circular holes, and the other through holes are long holes with their long axes in the horizontal direction.

[0009] In this beam end joint structure, the end of the beam is supported on the supporting structure via the joint plate and the drift pin. The holes are elongated holes except for some of the through holes, and the drift pins inserted into these elongated holes can move horizontally within the elongated holes, allowing the beam end to rotate around the drift pins, which have circular through holes. In other words, the beam end is joined to the supporting structure in a state close to a pin joint. If all of the drift pins were inserted into the circular holes in the joining plate, the joint would not be completely rigid, but would transmit bending moments between the beam and the supporting structural member while allowing slight relative displacement, resulting in a joint structure that includes uncertainties. In contrast, by making some of the through holes through which the drift pins are inserted into elongated holes as described above, a structure that is close to a pin joint and satisfactorily corresponds to structural calculations. In addition, by positioning the pin holes through which the drift pins are inserted closer to the bottom of the beam, the beam ends can be supported from below, preventing the beam from splitting, i.e., cracking in the approximately horizontal direction, below the supported part due to the shear force acting on the beam ends.

[0010] The invention of claim 2 is a beam end joint structure as described in claim 1, wherein the pin holes and through holes are arranged at a predetermined interval in the vertical direction to form a row of holes, and multiple rows are formed at intervals in the horizontal direction, and the holes in two adjacent rows are arranged in a staggered pattern with different height positions.

[0011] In this beam end joining structure, the pin holes for inserting the drift pins and the through holes in the joining plate are arranged in a staggered pattern, allowing multiple pin holes and through holes to be concentrated in a small area, making it possible to minimize movement of the drift pin within the long hole.

[0012] The invention of claim 3 is a beam end joint structure as described in claim 1, wherein the distance from the lower end of the beam to the lowest pin hole is set to maintain fire resistance of the joint between the beam and the supporting structural member, including the drift pin and the joint plate.

[0013] This beam-end joint structure provides the fire resistance required for a building even when the lower part of the beam is exposed to flames, and the beam can continue to be supported at the joint.

[0014] The invention of claim 4 is a beam end joint structure as described in claim 1, wherein the circular holes among the through holes are one closest to the central position between the two through holes located at the furthest positions, or a plurality of through holes close to the central position.

[0015] In this beam-end joint structure, the long hole in the joint plate can be located close to the circular hole, and the movement of the drift pin within the long hole can be kept small.

[0016] The invention of claim 5 is a beam end joint structure described in any of claims 1 to 4, wherein the supporting structural member is a supporting beam or a column, a space is provided between the side of the supporting beam or the column and the end face of the beam, and a heat absorbing material is inserted into the space.

[0017] When the supporting structural members are made of steel in this beam end joint structure, the supporting structural members will become hot in the event of a fire, but the heat can be transferred to the wooden beams, preventing the wooden beams from reaching or exceeding their combustion start temperature. Also, when the supporting structural members are made of wood, it is possible to delay the transfer of heat between the supporting structural members and the beams.

[0018] The invention of claim 6 is a beam end joint structure described in any of claims 1 to 4, wherein the supporting structural member is a supporting beam having a beam height smaller than the beam, the upper ends of the supporting beam and the beam are set at approximately the same height, the joint plate is arranged extending downward from the lower end of the supporting beam, and part or all of the drift pin joining the beam and the joint plate is arranged below the lower end of the supporting beam.

[0019] In this beam end joint structure, even when the height of the beam is greater than the height of the support beam, which is a supporting structural member, the beam can be supported at its lower part and joined to the support beam. Effect of the Invention

[0020] As explained above, in the beam end joint structure of the present invention, the joint state of the beam end allows rotational displacement, making it possible to perform structural analysis that is well suited to the state of the actual structure. In addition, by supporting the beam end at the bottom of the end face, splitting failure of the beam made of wood material can be suppressed. [Brief description of the drawings]

[0021] [Figure 1] 1A and 1B are plan and side views showing a beam end joint structure according to one embodiment of the present invention. [Diagram 2] 2 is an enlarged view showing the arrangement of joint plates and drift pins for joining beam ends used in the beam-end joint structure shown in FIG. 1. FIG. [Diagram 3] FIG. 11 is a plan view showing a beam end joint structure according to another embodiment of the present invention. [Figure 4] FIG. 11 is a plan view showing a beam end joint structure according to another embodiment of the present invention. [Diagram 5]11A and 11B are a plan view and a side view showing a beam end joint structure according to another embodiment of the present invention. [Figure 6] FIG. 11 is a side view showing a beam end joint structure according to another embodiment of the present invention. [Figure 7] FIG. 11 is a plan view showing a beam end joint structure according to another embodiment of the present invention. [Figure 8] FIG. 11 is a side view for explaining problems with a conventional beam end joint structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view and a side view of a beam-end joint structure according to one embodiment of the present invention. This beam-end joint structure is a structure in which the end face of a beam 1 made of wood is opposed to the side face of a steel beam 2 with an I-shaped cross section, and the steel beam 2 and the wood beam 1 are joined together. A joint plate 3 is fixed to the steel beam 2, which is a supporting structural member, with bolts 4, and the wood beam 1 is joined to this joint plate 3 via multiple drift pins 5.

[0023] A beam support member 6 having a vertical surface approximately perpendicular to the web 2a of the steel beam 2 is provided at the portion where the wooden beam 1 is joined to the steel beam 2. This beam support member 6 is made of a steel plate and is welded to the web 2a, the upper flange 2b, and the lower flange 2c, with its upper portion projecting beyond the side edges of the upper flange 2b and the lower flange 2c, and multiple bolt holes for joining the joining plate 3 are provided in this portion.

[0024] The joining plate 3 is a rectangular steel plate, part of which overlaps with the part of the beam-receiving member 6 that protrudes from the upper flange 2b and the lower flange 2c, and bolt holes are provided in parts corresponding to the bolt holes of the beam-receiving member 6. The joining plate 3 is fixed to the steel beam 2 by tightening the bolts 4 inserted through both of the overlapping bolt holes. The bolts 4 may be normal bolts, but it is preferable to use high-strength bolts.

[0025] The wooden beam 1 is made of laminated timber with a rectangular cross section, and has a large beam height relative to its width. It is joined so that its top surface is at approximately the same height as the top surface of the steel beam 2. A vertical slit is provided on the end surface of this wooden beam 1, and a joining plate 3 fixed to the beam support member 6 is inserted into this slit.

[0026] The wooden beam 1 has a plurality of pin holes that penetrate horizontally from one side surface to the opposite side surface and through which drift pins 5 are inserted. The joining plate 3 has through holes at positions corresponding to the pin holes, and the wooden beam 1 and the joining plate 3 are joined together by the drift pins 5 that are inserted from the pin holes of the wooden beam 1 into the through holes provided in the joining plate 3.

[0027] The pin holes provided in the wooden beam 1 are circular holes with a diameter almost the same as the circular cross section of the drift pin 5 to be inserted, and are formed so as to fit closely to the outer circumferential surface of the inserted drift pin 5. These pin holes are provided in two rows of holes formed at regular intervals in the vertical direction as shown in Fig. 1, and the pin holes are formed so that the height positions of the pin holes in both rows are different from each other, that is, in a staggered pattern. These pin holes are formed downward within the beam height of the wooden beam 1, and the pin hole formed at the lowest position is set at a height required from the underside of the wooden beam 1 for fire resistance or structure. The height required from the standpoint of fire resistance is, for example, the height at which the drift pin 5 does not lose its ability to support the wooden beam 1 even during a specified fire resistance time, and the height required from a structural standpoint can be defined as the height at which the wooden beam 1 does not crack or undergo any other deformation when supported by the drift pin 5.

[0028] On the other hand, as shown in Fig. 2, the through holes formed in the joint plate 3 at positions corresponding to the pin holes provided in the wooden beam 1 are circular, and the two through holes 3a located in the middle of the row in the height direction are set to a size that allows the drift pin 5 to be inserted with almost no gap. Also, the through holes 3b located higher and lower than the two circular holes are long holes with their long axes in the horizontal direction.

[0029] In the embodiment shown in Fig. 2, there are two through holes 3a that are circular holes, but there may be one, or three or more. However, when multiple through holes are circular holes, it is preferable to select multiple through holes that are circular and to arrange them in as small an area as possible. Further, the through hole 3a which is a circular hole is the middle one arranged in the vertical direction, but the upper through hole may be a circular hole. On the other hand, in the embodiment shown in Figure 2, the through holes in the joining plate 3 and the pin holes in the wooden beam are formed in two rows, but they may also be formed in one row or three or more rows, and can be designed appropriately depending on the shear force acting on the beam end.

[0030] Generally, when a load acts on a beam, the beam deflects and, if the end of the beam is restrained, a bending moment occurs at the end of the beam. When the end of a beam is joined to the side of another beam, the bending moment is transmitted from the end of the beam to the other beam, and a torsional moment acts on the other beam. However, in the beam end joint structure of the above embodiment, when the wooden beam 1 is deflected, no large restraining force acts on the beam end, and rotational displacement of the beam end is permitted. In other words, the drift pin 5 inserted into the pin hole of the wooden beam 1 is inserted into the long hole 3b of the joint plate 3 as shown in Figure 2, and moves horizontally together with the wooden beam 1, and the beam end of the wooden beam 1 rotates around the circular hole 3a of the joint plate 3. At this time, some restraining force acts due to friction, etc., but the bending moment transmitted from the beam end to the steel beam 2, which is a supporting structural member, is greatly reduced.

[0031] As a result, the end of the wooden beam 1 behaves in a manner similar to a pin joint with the steel beam 2, which matches well with the results of structural analysis performed on a pin joint. This eliminates the uncertainty caused by the discrepancy between the behavior of the actual beam end joint and the behavior in the structural analysis, enabling a highly reliable design.

[0032] In addition, the pin holes of the wooden beam 1 through which the drift pins 5 are inserted are formed toward the lower side of the beam height, which prevents the wooden beam 1 from cracking below the area through which the drift pins 5 are inserted. In other words, if the shear force acting over the entire beam height of the wooden beam 1 is supported by the upper part of the beam end, a vertical tensile force acts on the lower side of the supported area, making it easier for cracks to occur, but the above configuration can prevent cracks. Furthermore, as the arrangement of the drift pins 5 makes it possible to prevent cracks, the length between the position where the drift pins 5 are arranged and the beam end surface can be reduced, and the position where rotational displacement occurs can be brought closer to the supporting structural member, reducing the bending moment generated in the supporting structural member.

[0033] FIG. 3 is a plan view of a beam-end joint structure according to another embodiment of the present invention. This beam end joint structure can be adopted when a wide member is used as the wooden beam 11. The steel beam 12 has beam support members 16 welded to the web, upper flange, and lower flange of the steel beam 12, similar to the beam-end joint structure shown in Fig. 1, but the two beam support members 16 are arranged at a specified interval to form parallel vertical surfaces. Then, the connecting plates 13 are connected to each beam support member 16 by high-strength bolts 14. Two slits are provided in the vertical direction on the end face of the wooden beam 11 so as to correspond to the interval between the connecting plates 13 fixed in parallel, and the connecting plates 13 are inserted into these slits.

[0034] A plurality of pin holes are provided substantially horizontally from one side of the wooden beam 11 toward the opposite side, and through holes are provided in the joint plate 13 at positions corresponding to the pin holes. Drift pins 15 are inserted into these pin holes from the side of the wooden beam 11 and pass through the through holes of the joint plate 13. The drift pins 15 may have a length equal to the width of the wooden beam 11 and pass through the wooden beam 11 and the two joint plates 13, but it is preferable to insert drift pins 15 shorter than the beam width into one pin hole from each side of the wooden beam 11 and pass through the through holes of one of the joint plates 13, as shown in FIG. 3.

[0035] The arrangement of the pin holes formed in the wooden beam 11 and the through holes formed in the two joining plates 13 can be similar to that of the beam end joining structure shown in Figure 1, with some of the through holes formed in the joining plates 13 being circular holes and the other through holes being long holes with their long axes in the horizontal direction. As a result, like the beam-end joint structure shown in Figure 1, the joint between the steel beam 12 and the wooden beam 11 reduces the transmission of bending moment from the wooden beam 11, and behaves in a state similar to that of a pin joint. This allows the generation of cross-sectional forces to be in good agreement with the results of structural analysis.

[0036] FIG. 4 is a plan view of another embodiment of the present invention, in which an end of a wooden beam 21 is joined to the side of a steel column 22 made of a square steel pipe. In this beam-end joint structure, a beam support member 26 made of a steel plate is attached by welding to the side surface of a steel column 22. A joint plate 23 is fixed to this beam support member 26 by a high-strength bolt 24. The joining plate 23, the wooden beam 21 and the drift pin 25 joining them can be configured in the same way as the beam end joining structure shown in Figure 1, and the arrangement of the through holes formed in the joining plate 23 and the pin holes provided in the wooden beam 21, the shape of the through holes, etc. can also be configured in the same way. As a result, this beam end joint structure also provides the same effects as the beam end joint structure shown in FIG.

[0037] FIG. 5 is a plan view and a side view showing another embodiment of the beam-end joint structure of the present invention. This beam end joint structure joins a wooden beam 31 to another wooden beam 32, which is a supporting structural member, and joins the end face of the first wooden beam 31 facing the side of the second wooden beam 32, which is also a supporting structural member. The joining plate 33 used in this joining structure is directly fixed to the second wooden beam 32 with bolts 34. This joining plate 33 has a mounting base plate 33a that abuts against the side surface of the second wooden beam 32, and an overhanging plate portion 33b that protrudes vertically from the mounting base plate 33a. The joining plate 33 is attached to the second wooden beam 32 so that the plate surface of the overhanging plate portion 33b is in the vertical direction and protrudes in the axial direction of the first wooden beam 31.

[0038] A plurality of bolt holes are provided in the mounting base plate 33a of the joining plate 33, and through holes for inserting bolts are provided in the second wooden beam 32 at positions corresponding to the bolt holes. The joining plate 33 is fixed to the second wooden beam 32 by twisting nuts 37 onto the bolts 34 inserted into the bolt holes and through holes and tightening them via a support plate 38.

[0039] A vertical slit is formed on the end face of the first wooden beam 31, into which the overhanging plate portion 33b of the joining plate 33 is inserted. A plurality of through holes 33c are formed in the overhanging plate portion 33b of the joining plate 33, into which the drift pins 35 are inserted, and the first wooden beam 31 has pin holes at corresponding positions extending from one side surface to the opposite side surface. The joining plate 33 and the first wooden beam 31 are joined together by inserting the drift pins 35 into these pin holes and the through holes 33c of the joining plate 33. The arrangement of the through holes 33c formed in the joining plate 33 and the pin holes provided in the first wooden beam 31, as well as the shape of the through holes 33c, can be configured in a similar manner to the beam end joining structure shown in Figure 1, and the same effects can be achieved.

[0040] FIG. 6 is a side view of a beam-end joint structure according to another embodiment of the present invention. In this beam-end joint structure, the steel beams 42 and wooden beams 41 which are supporting structural members have large beam heights, and the beam height of the wooden beams 41 is even greater than that of the steel beams 42 . The steel beam 42 has an I-shaped cross section and is provided with a beam support member 46 made of a steel plate. This beam support member 46 is attached so that its plate surface is vertical and perpendicular to the web 42a, and protrudes in the axial direction of the wooden beam 41 from the side edge of the lower flange 42c near the lower surface of the steel beam 42. Bolt holes for fixing the joining plate 43 are provided in the part protruding from the lower flange 42c. The joining plate 43 is made of a steel plate, and a portion of it overlaps with the beam support member 46 while protruding downward from the underside of the steel beam 42 . The joining plate 43 is fixed to the beam support member 46 by a high-strength bolt 44 .

[0041] A vertical slit is formed on the end face of the wooden beam 41, and a joining plate 43, fixed to a beam receiving member 46 and protruding in the axial direction of the wooden beam 41, is inserted into the slit. A plurality of through holes are formed in the joining plate 43 for inserting drift pins 45 therethrough, and pin holes are formed in the wooden beam 41 at corresponding positions. The joining plate 43 and the wooden beam 41 are joined together by inserting the drift pins 45 into these pin holes and the through holes in the joining plate 43.

[0042] In this beam-end joint structure, the multiple through holes formed in the joint plate 43 and the multiple pin holes formed in the wooden beam 41 are arranged so that some of them are distributed below the lower surface of the steel beam 42. As with the beam-end joint structure shown in Fig. 1, the through holes provided in the joint plate 43 can be structured so that some of the through holes are circular holes and the other through holes are elongated holes to allow rotational displacement of the end of the wooden beam 41. Even if the beam height of the wooden beam 41 increases, the wooden beam 41 can be supported at the lower part of the beam height and joined to the steel beam 42, which is a supporting structural member, and cracks at the end of the wooden beam 41 can be effectively prevented.

[0043] FIG. 7 is a plan view of a beam-end joint structure according to another embodiment of the present invention. In this beam-end joint structure, the steel beam 52, which is a supporting structural member, the beam support member 56 provided on the steel beam 52, the wooden beam 51, the joint plate 53 for joining the wooden beam 51 and the steel beam 52, the arrangement and shape of the through holes formed in the joint plate 53 and the pin holes formed in the wooden beam 51 are the same as those of the beam-end joint structure shown in Fig. 1. In this beam-end joint structure, fireproof coatings 57, 58 are applied to the wooden beam 51 and the steel beam 52. Also, a gypsum board 59 is attached to the entire end face of the wooden beam 51 as a heat absorbing material, except for the part where the joint plate 53 is inserted into the slit. This gypsum board 59 is supported so as to be in close contact with the joint plate 53 near the end face of the wooden beam 51.

[0044] In addition to the above-mentioned gypsum board, the heat absorbing material attached to the end face of the wooden beam may be a calcium silicate board, rock wool, cement board, glass wool, mortar board, stone board, glass board, fiber reinforced cement board, non-flammable sheet, etc. Furthermore, the fire-resistant coatings 57, 58 of the wooden beams 51 and the steel beams 52 cover the sides and undersides thereof, and may be made of gypsum board, calcium silicate board, rock wool board, cement board, ALC panel, concrete board, etc. The fire-resistant coatings 57, 58 may cover the entire periphery of the wooden beams 51 and the steel beams 52, that is, cover both side surfaces and the top and bottom surfaces.

[0045] In this beam-end joint structure, the wooden beam 51 and the steel beam 52, which is a supporting structural member, are provided with fire-resistant coatings 57, 58, so that the temperature rise of the wooden beam 51 and the steel beam 52 can be delayed even in the event of a fire. In addition, the temperature rise of the steel beam 52 occurs earlier than that of the wooden beam 51 and becomes high temperature, but a part of the heat transferred to the wooden beam 51 through the beam support member 56 and the joint plate 53 is absorbed by the gypsum board 59. In addition, the radiant heat from the high-temperature steel beam 52 to the end face of the wooden beam 51 and the convection heat in the space between the end faces of the steel beam 52 and the wooden beam 51 are also absorbed. The gypsum board 59 contains about 20% crystal water, which is released when heated and creates a heat absorption effect due to the latent heat of evaporation. In addition, heat is absorbed by the heat storage effect due to the temperature rise of the gypsum board 59. In addition, when a material other than the above-mentioned gypsum board is used as the heat absorbing material, the same effect can be obtained, although the amount of heat absorption will differ.

[0046] The beam end joint structure described above is an embodiment of the invention related to the present application, and the invention related to the present application is not limited to the above embodiment, and can be designed as appropriate within the scope of the invention related to the present application. For example, an embodiment in which a first wooden beam 31 is joined to a second wooden beam 32 has been described as an embodiment in which the supporting structural member is made of wood, but wooden beams can be joined in the same manner even if the supporting structural member is a wooden pillar. In the above-described embodiment, the supporting structural members are steel or wood materials, but the supporting structural members are not limited to these and may be concrete beams or columns. In this case, the joining plate can be fixed to the column or beam using an anchor member partially embedded in the concrete column or beam. Also, a bracket may be fixed to the concrete column or beam using an anchor member, and the joining plate may be fixed to the bracket.

[0047] Furthermore, the details of the beam end joint structure can be designed appropriately with regard to the following points: 1) When the supporting structural member is a steel beam, the beam support member may be designed as desired, such as one whose upper part protrudes beyond the side edges of the upper and lower flanges as shown in Fig. 1, one whose lower part protrudes beyond the side edges of the upper and lower flanges as shown in Fig. 6, one whose part protrudes below the lower flange, one whose part protrudes from the middle, etc. Also, one that does not have a part protruding from the side edges of the upper or lower flange and is joined by inserting a joining plate between the upper and lower flanges may be used. 2) In the embodiment described above, the joining plate is a rectangular steel plate, but this is not limited to a rectangular shape and other shapes such as a trapezoid can also be used. 3) In the embodiment described above, the wooden beam has a rectangular cross-section with the beam height being greater than the beam width, but this is not limited to this, and it is also possible to use a rectangular cross-section with the beam width being greater than the beam height, or a cross-section of another shape. 4) When the supporting structural member is a beam, in the embodiment described above, the upper surface of the wooden beam and the upper surface of the steel beam or wooden beam which is the supporting structural member are set at approximately the same height, but this is not limited to this, and the upper surface of the wooden beam to be joined may be set higher or lower than the upper surface of the beam which is the supporting structural member, so as to create a step. [Explanation of symbols]

[0048] 1: wood beam, 2: steel beam, 2a: web, 2b: upper flange, 2c: lower flange, 3: connection plate, 3a: circular hole among through holes provided in the connection plate, 3b: oblong hole among through holes provided in the connection plate, 4: bolt, 5: drift pin, 6: beam support member, 11: Wood beam, 12: Steel beam, 13: Joint plate, 14: High strength bolt, 15: Drift pin, 16: Beam support member, 21: Wood beam, 22: Steel column, 23: Joint plate, 24: High strength bolt, 25: Drift pin, 26: Beam support member, 31: first wooden beam, 32: second wooden beam (supporting structural member), 33: joint plate, 33a: mounting base of joint plate, 33b: protruding plate portion of joint plate, 33c: through hole provided in joint plate, 34: bolt, 35: drift pin, 37: nut, 38: support plate, 41: wood beam, 42: steel beam, 42a: web, 42b: upper flange, 42c: lower flange, 43: connection plate, 44: high strength bolt, 45: drift pin, 46: beam support member, 51: Wood beam, 52: Steel beam, 53: Joint plate, 54: High strength bolt, 55: Drift pin, 56: Beam support member, 57, 58: Fireproof coating, 59: Gypsum board

Claims

1. A beam end joint structure in which an end of a beam made of wood material and having a rectangular cross section is joined to a supporting structural member via a joining plate fixed to the supporting structural member, The joining plate has a vertical surface protruding in the axial direction of the beam, The joining plate is inserted into a vertical slit provided on the end surface of the beam, The beam and the joining plate are joined by drift pins inserted into a plurality of pin holes penetrating horizontally from a side surface of the beam and a plurality of through holes provided at positions corresponding to the pin holes of the joining plate, The pin holes are arranged at a predetermined distance from the lower end of the beam to the lowest pin hole and are arranged toward the lower side of the beam height. A beam end joining structure characterized in that some of the multiple through holes provided in the joining plate, one or several through holes located in close proximity to each other, are circular holes, and the other through holes are long holes having their major axis in the horizontal direction.

2. The beam end joint structure described in claim 1, characterized in that the pin holes and through holes are arranged at a predetermined interval in the vertical direction to form a row of holes, and multiple rows are formed at intervals in the horizontal direction, and the heightwise positions of the holes in two adjacent rows are staggered in a staggered pattern.

3. The beam end joint structure described in claim 1, characterized in that the distance from the lower end of the beam to the lowest pin hole is set to maintain fire resistance of the joint between the beam and the supporting structural member, including the drift pin and the joint plate.

4. The beam end joint structure described in claim 1, characterized in that the circular holes among the through holes are one that is closest to the central position between the two through holes that are furthest apart, or a plurality of through holes that are close to the central position.

5. A beam end joint structure described in any one of claims 1 to 4, characterized in that the supporting structural member is a supporting beam or a pillar, a space is provided between the side of the supporting beam or the pillar and the end face of the beam, and a heat absorption material is inserted into the space.

6. The supporting structural member is a supporting beam having a beam height smaller than that of the beam, and the upper ends of the supporting beam and the beam are set at approximately the same height. The joint plate is provided extending downward from the lower end of the support beam, 5. The beam end joint structure according to claim 1, wherein a part or all of the drift pins that join the beam and the joint plate are provided below the lower end of the support beam.

Images