JP7019499B2 - Truss beam - Google Patents

Description

The present disclosure relates to truss beams having a high deformation capacity during an earthquake.

The truss beam is composed of individual chords and slanted lumbers, and is a member that resists the axial force generated in each member in the elastic region. Generally, the chords are straight or curved, and the slanted lumber is straight. There are many.

The deformation ability of the steel frame member is mainly determined by the structural characteristic coefficient (hereinafter referred to as "Ds value") by the width-thickness ratio of the individual material, and is applied to the filling material member of a single material such as H-shaped steel. The larger the deformation performance, the smaller the Ds value, and the smaller the seismic force for design. However, it cannot be applied to the width-thickness ratio of the individual material of the truss beam, and there is no member type of the truss beam itself. It is customary. Therefore, when installing truss beams, it is necessary to design with a large seismic force (large Ds value) as a "building" with poor deformation performance, including not only truss beams but also other columns and beams. It was an uneconomical design.

In Non-Patent Document 1, in a flat truss member incorporated in a rigid frame frame, a buckling restraining member or a member having stable history characteristics is replaced with a buckling restraining member, so that the entire truss frame has a stable history. It is stated that it is possible to design to give characteristics, and it will be possible to handle the frame in the same way as the filling material (H-shaped steel, etc.) without considering the influence of buckling of individual materials.

For example, Patent Document 1 describes a buckling restraining member. This buckling restraining member is used as a vibration damping brace that is diagonally arranged in the frame structure of columns and beams of a building, and is made of steel pipe and steel pipe inserted into the steel pipe so that both ends protrude. It has a core material of the above and a filler filled in a steel pipe so as not to adhere to the core material.

Japanese Unexamined Patent Publication No. 2005-146673

Architectural Institute of Japan, "Guidelines for Buckling Design of Steel Structures", Architectural Institute of Japan, November 2009

However, the buckling restraining member described in Patent Document 1 is used as a vibration damping brace that is diagonally arranged in the frame structure of columns and beams of a building. In addition, since both ends of the core material are exposed from the steel pipe, there is a case where the core material breaks at the boundary between the portion located in the steel pipe and the portion exposed from the steel pipe, that is, the neck breaks and buckles occur. ..

In view of such a problem, the present invention provides a truss beam capable of easily arranging a buckling restraining member in which buckling of the neck is prevented on a part of the chord material and handling the frame in the same manner as the filling material. The purpose is to provide.

The truss beam according to at least some embodiments of the present invention has an upper chord member (2,42), a lower chord member (3,22,32) and a plurality of diagonal members (4), and is a pair of structural members ( It is a truss beam (1,21,31,41) supported by 5,5), and the lower chord member is a main body portion (6) having a long member and a part of the lower chord member in the extending direction. It has a buckling restraint member (8, 23, 33) arranged to replace the main body portion in the section of the above, and the buckling restraint member is joined to the main body portion or the structural member and faces each other. A pair of joints (10, 10) and a core material (11, 34) fixed to the joint with both ends corresponding to each other form a tubular shape through which the core material is inserted, and one end side corresponds to each other. It is characterized by having a pair of restraining materials (12) fixed to the joint body.

According to this configuration, the buckling restraining member can be easily arranged as a part of the lower chord material by the joint, and both ends of the core material are covered with the restraining material, so that the neck bending buckling is prevented. To.

In the truss beam (1,31,41) according to at least some embodiments of the present invention, the buckling restraining member (8,33) is 2 from the end of the truss beam among the plurality of slanted lumbers. It is characterized in that it is arranged between the lower ends of the second diagonal member (4b) and the third diagonal member (4c) arranged in the third and third positions.

According to this configuration, the buckling restraining member can be most easily plasticized in the lower chord material after the lower end side of the diagonal member is joined to the main body, but it can be arranged at a position relatively close to the end portion having a short section length, and the plastic region. A large length of (core material) can be secured.

The truss beam (21) according to at least some embodiments of the present invention is the first and second arrangement from the end of the truss beam among the plurality of diagonal lumbers in the first configuration. The lower ends of the 1 diagonal member (4a) and the 2nd diagonal member (4b) are characterized in that they are joined to one of the pair of restraint members.

According to this configuration, the first and second diagonal members are joined to one of the pair of restraint materials to form a truss, and then the end portion of the lower chord material, which is most easily plasticized but has a short section length. A buckling restraining member can be arranged at the center, and a large length of the plastic region (core material) can be secured.

In any of the above configurations, the truss beams (1,21,31) according to at least some embodiments of the present invention have ends of the pair of restraints on adjacent sides separated from each other. It is characterized by that.

According to this configuration, the core material expands and contracts during an earthquake, so that the energy of the earthquake can be efficiently absorbed.

In the truss beam (31) according to at least some embodiments of the present invention, the buckling restraining member (33) is filled in the pair of restraining materials and does not adhere to the core material in the above configuration. Further having a filler (13), the core material (34) is inserted into a first core material (35) inserted into one of the pair of restraints and the other of the pair of restraints. The second core material (36) is provided, and the ends of the first core material and the second core material on the side close to each other protrude from the pair of restraint materials and are joined to each other. It is characterized by.

According to this configuration, the first and second core materials can be joined to each other after the filler is injected, so that the workability of the filler is improved. Further, the dimensions of the buckling restraining member can be adjusted by adjusting the distance between the first and second core materials.

The truss beam (41) according to at least some embodiments of the present invention has the first to third configurations, wherein the upper chord member (42) has an upper chord main body portion (43) having a long member. And the upper chord buckling restraining member (8') arranged so as to replace the upper chord main body portion in a part section in the extending direction of the upper chord member, and the upper chord buckling restraining member is the upper chord. A pair of upper chord joints (10') that are joined to the main body or the structural member and face each other, and an upper chord core material (11') whose both ends are fixed to the corresponding upper chord joints, respectively. The upper chord core material has a tubular shape through which the upper chord core material is inserted, and one end side has a pair of upper chord restraint materials (12', 12') fixed to the corresponding upper chord joint body, and the pair of restraint materials. It is characterized in that the ends on the side close to each other are in contact with each other, and the ends on the side close to each other of the pair of upper chord restraints are in contact with each other.

According to this configuration, the core material and the upper chord core material are alternately stretched to absorb energy at the time of an earthquake, and the center of the core material and the upper chord core material is a pair of restraint material and a pair of upper chord restraint material, respectively. Since it is covered with, it is possible to prevent buckling in the center of the core material and the upper chord core material.

According to the present invention, it is possible to provide a truss beam capable of easily arranging a buckling restraining member in which buckling by bending the neck is prevented on a part of a chord material and handling a frame like a filling material. ..

Front view of the truss beam according to the first embodiment II-II sectional view in FIG. Sectional drawing which shows the modification of 1st Embodiment Front view of the truss beam according to the second embodiment Front view of buckling restraint member in truss beam according to the third embodiment Front view of the truss beam according to the fourth embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 show the truss beam 1 according to the first embodiment. The truss beam 1 has an upper chord member 2, a lower chord member 3, and a plurality of diagonal members 4, and both ends thereof are supported by a pair of columns 5 and 5. The truss beam 1 may have a bundle member (not shown). Since the truss beam 1 has a substantially mirror image symmetrical shape, one of both ends will be described as an example, but the other end also has the same configuration.

The upper chord member 2 and the lower chord member 3 are arranged substantially parallel to each other along the horizontal direction. The upper chord member 2 and the lower chord member 3 of the present embodiment are linear members, but may be curved members. Although H-shaped steel is used for the entire upper chord material 2 and the main body 6 of the lower chord material 3, long steel materials such as other shaped steels and steel pipes may be used. In the H-shaped steel used for the entire upper chord member 2 and the main body portion 6 of the lower chord member 3, a pair of flanges face each other in the vertical direction, and the web is arranged along the vertical plane. Both ends of the upper chord member 2 and the lower chord member 3 are rigidly or pin-bonded to the corresponding columns 5, respectively.

As the plurality of diagonal members 4 are arranged from one end side to the other end side in the extending direction of the truss beam 1, those directed diagonally downward and those directed diagonally upward are alternately arranged. When indicating a plurality of diagonal members 4 arranged at specific positions, the first diagonal member 4a, the second diagonal member 4b, and the third diagonal member are arranged in order from the one arranged at the end to the center. It is described as 4c and the 4th diagonal member 4d, and when an unspecified object or the whole is indicated, it is simply referred to as a diagonal member 4. Each diagonal member 4 is made of a long steel member such as H-shaped steel or a pair of channel steels arranged in parallel with each other. The angles of the diagonal members 4 with respect to the upper chord member 2 and the lower chord member 3 are substantially equal to each other. The upper end of the first diagonal member 4a is rigidly or pin-bonded to the upper chord member 2 and the column 5 via the gusset plate 7. In two diagonal members 4 and 4 whose upper end sides are adjacent to each other, such as the second diagonal member 4b and the third diagonal member 4c, the upper end sides thereof are rigidly or pin-bonded to each other via a common gusset plate 7. At the same time, it is rigidly or pin-bonded to the upper chord member 2. Further, in two diagonal members 4 and 4 whose lower end sides are adjacent to each other such as the first diagonal member 4a and the second diagonal member 4b, these lower end sides are rigidly joined or pinned to each other via a common gusset plate 7. It is joined and rigidly joined or pin-joined to the lower chord member 3. The upper chord member 2, the lower chord member 3 and the diagonal member 4 are fastened to the gusset plate 7 with bolts, nuts (not shown) or the like.

The lower chord member 3 has a main body portion 6 substantially made of H-shaped steel, and a buckling restraining member 8 arranged so as to be aligned with the main body portion 6 in the extending direction of the lower chord member 3. In other words, in a part of the lower chord member 3, the member constituting the main body 6 is replaced with the buckling restraining member 8. The buckling restraining member 8 is provided in a section of the lower chord member 3 that is easily plasticized. The section most easily plasticized is the section from the joint portion 9 to the pillar 5 to the lower chord member 3 of the lower end of the first diagonal member 4a and the lower end of the second diagonal member 4b among the plurality of diagonal members 4. However, the length of this section is from the joint 9 to the lower chord member 3 at the lower end of the first diagonal member 4a and the lower end of the second diagonal member 4b to the lower end of the third diagonal member 4c and the lower end of the fourth diagonal member 4d. It is about half the length of the section up to the joint portion 9 to the lower chord member 3, and there is a possibility that the length required for the buckling restraining member 8 cannot be secured. Therefore, in the first embodiment, the buckling restraining member 8 is formed from the joint portion 9 between the lower end of the first diagonal member 4a and the lower end of the second diagonal member 4b to the lower end of the third diagonal member 4c and the fourth diagonal member 4d. It is arranged in the section up to the joint portion 9 with the lower end.

The buckling restraining member 8 is fixed to a pair of joints 10 and 10 which are joined to the main body 6 and face each other, and both ends thereof are fixed to the pair of joints 10 and 10, and the lower chord member 3 extends. A pair of restraining materials 12 which are arranged so as to be aligned with the main body 6 in the direction and each of which has a cylindrical shape through which the core material 11 is inserted and whose one end side is fixed to the corresponding joint body 10. It has a filler 13 that is filled in each of the 12 and the pair of restraints 12, 12 and does not adhere to the core 11.

The joint 10 is made of a flat plate made of steel. One end side of the core material 11 and the restraining material 12 is fixed to the joint body 10 by welding or the like. At the end of the main body 6 to be joined to the buckling restraining member 8, a main body side joint 14 made of a steel flat plate is provided, and the main body side joint 14 is a main part of the main body 6. It is fixed to the constituent H-shaped steel by welding or the like. Since the joint 10 and the main body side joint 14 are fastened with fasteners 15 such as bolts and nuts in a state of being in contact with each other, both ends of the buckling restraining member 8 are joined to the main body 6. ing.

The core material 11 is made of one H-section steel, and a pair of flanges face each other in the vertical direction, and the web is arranged along the vertical plane. As the core material 11, as in the modified example shown in FIG. 3, a pair of channel steels 16 and 16 arranged in parallel with each other are opposed to each other so that the openings 16a face opposite to each other. (FIG. 3 (A)) or a plurality of steel flat plates 17 arranged in parallel with each other (FIG. 3 (B)) may be used.

Each restraining material 12 is made of a steel pipe such as a square steel pipe. The adjacent ends of the pair of restraints 12, 12 are separated from each other. The value obtained by dividing this separation length by the length of the core material 11 is the maximum compressive strain of the core material 11. It should be noted that the pair of restraint members 12 and 12 may be deformed so that their adjacent ends abut against each other (the separation length is set to 0). The bending restraint member 8 is of a tensile yield type.

The filler 13 is made of mortar or the like. The filler 13 is formed by applying an anti-adhesion agent such as a formwork release material, oil paint or asphalt to a portion of the core material 11 located inside the pair of restraining materials 12 and 12, and then applying the pair of restraining materials 12 and 12. Filled inside. Therefore, the filler 13 does not adhere to the core material 11. A pair of restraining materials 12, 12 and filler 13 prevents buckling of the core material 11. It should be noted that the filler 13 may not be provided, and the core material 11 may be prevented from buckling by using only a pair of restraining materials 12 and 12.

The core material 11 is prevented from buckling by a pair of restraining materials 12 and 12 and a filler 13, and can be expanded and contracted in the extending direction because the filler 13 is not attached. Therefore, the buckling restraining member 8 can stably absorb energy such as an earthquake. Further, since the buckling restraining member 8 is arranged in the portion of the lower chord member 3 that is easily plasticized, the truss beam 1 can handle the frame in the same manner as the filling material without considering the influence of the buckling of the individual members. That is, by improving the deformation capacity of the truss beam 1, the Ds value at the time of calculating the required holding horizontal strength can be reduced, and the amount of steel material can be reduced.

Since both ends of the core material 11 are covered with a pair of restraining materials 12 and 12 and a filler 13, buckling of the buckling restraining member 8 and local buckling of both ends of the core material 11 occur. Can be prevented. Further, the central portion of the core material 11 not covered by the pair of restraining materials 12 and 12 and the filler 13 changes its shape more slowly than the portion where buckling is likely to occur in the conventional product, so that the force can be smoothly applied. It is transmitted and buckling is unlikely to occur.

The buckling restraining member 8 has a joint body 10 in which the end portion of the core material 11 and the end portion of the restraining material 12 are fixed to one surface. Therefore, by fixing the pair of joints 10, 10 to the main body 6, the buckling restraining member 8 can be easily attached to the main body 6. Further, since general shaped steels distributed in the market can be used for the core material 11 and the pair of restraining materials 12, 12, the increase in cost can be suppressed.

The truss beam 21 according to the second embodiment will be described with reference to FIG. In the description, the configurations common to the first embodiment are omitted from the description and the same reference numerals are given.

The lower chord member 22 of the truss beam 21 has a main body portion 6 and a buckling restraining member 23. The buckling restraining member 23 extends below the first diagonal member 4a and the second diagonal member 4b. The buckling restraint member 23 has a pair of joints 10, 10, a core material 11, a pair of restraint materials 12, 12 and a filler 13 as in the first embodiment.

One of the pair of restraint members 12 and 12 is fixed to the column 5 via the joint 10 at one end side which is the end side of the buckling restraint member 23, and the other end which is the center side of the buckling restraint member 23. On the side, the lower end side of the first diagonal member 4a and the second diagonal member 4b is fixed via the gusset plate 7. The other of the pair of restraint members 12 and 12 is fixed to the H-shaped steel constituting the main body 6 via the joint 10 and the main body side joint 14 at one end side of the buckling restraint member 23. Has been done.

In this way, by fixing the lower end sides of the first and second diagonal members 4a and 4b to one of the restraining members 12 via the gusset plate 7, the first and second diagonal members 4a and 4b and the lower chord member 3 are formed. The buckling restraining member 8 can be arranged so as to straddle the joint portion 9. Therefore, after being established as a truss, the buckling restraining member 23 can be arranged at the end portion of the lower chord material 3 which is most easily plasticized but has a short section length, and the length of the core material 11 which is a plastic region can be secured large. Can be done. The lower ends of the first and second diagonal members 4a and 4b may be fixed to the other restraint member 12.

The truss beam 31 according to the third embodiment will be described with reference to FIG. The lower chord member 32 of the truss beam 31 has a main body portion 6 and a buckling restraining member 33. The buckling restraining member 33 has a pair of joints 10, 10, a pair of restraining materials 12, 12 and a filler 13 as in the first embodiment, and is arranged in the same manner as in the first embodiment. However, the configuration of the core material 34 is different from that of the first embodiment.

The core material 34 has a first core material 35 fixed to one of a pair of joints 10 and 10 on one end side and inserted through a restraining material 12 fixed to the joint 10 and 1 on one end side. It has a second core material 36 fixed to the other of the paired joints 10 and 10 and inserted through a restraining material 12 fixed to the joint 10. The first and second core materials 35 and 36 are each made of a long steel material such as H-shaped steel. The other ends of the first and second core materials 35 and 36 project from the restraint material 12, respectively, and are joined to each other. The other ends of the first and second core members 35 and 36 are joined to each other by being fastened with fasteners 38 such as bolts and nuts together with a steel joint plate 37 arranged so as to abut against both. To.

The first and second core materials 35 and 36 can be joined to each other after the filler 13 is injected into the respective restraining materials 12. Therefore, the workability of the filler 13 is improved. Further, in order to join the first and second core materials 35 and 36, it is necessary to increase the distance between the ends of the pair of restraining materials 12 and 12 on the sides close to each other as compared with the first embodiment. .. In this section, the buckling restraint of the core material 34 is reduced, but the buckling is suppressed by the reinforcing effect of the joint plate 37. Further, the length of the section in which the buckling restraining member 33 should be installed may vary depending on the construction error of the main body 6, but the distance between the first and second core members 35 and 36 is determined according to the construction error. By adjusting, the dimensions of the buckling restraint member 33 can be adjusted.

The truss beam 41 according to the fourth embodiment will be described with reference to FIG. In the fourth embodiment, the upper chord member 42 is arranged so as to be aligned with the upper chord main body 43 substantially made of H-shaped steel and the upper chord main body 43 in the extending direction of the upper chord member 42. Has 8'and. In other words, in a part of the section of the upper chord member 42, the member constituting the upper chord body portion 43 is replaced with the upper chord buckling restraining member 8'. The first-string buckling restraint member 8'has a pair of upper-string joints 10', 10', a pair of upper-string cores 11', a pair of upper-string restraints 12', 12', and a filler 13'. Each has a configuration corresponding to a pair of joints 10, 10, a core material 11, a pair of restraint materials 12, 12 and a filler 13 in the lower chord material 3. The buckling restraining member 8 of the lower chord member 3 is arranged below the second and third diagonal members 4b and 4c as in the first embodiment. The upper chord buckling restraining member 8'is arranged above the first and second diagonal members 4a and 4b, one upper chord joint 10'is joined to the pillar 5, and the other upper chord joint 10'is the main body portion. It is joined to the upper chord main body 43 via the main body side upper chord joint 14'having the same configuration as the side joint 14. The adjacent ends of the pair of restraints 12 and 12 are in contact with each other, and the adjacent ends of the pair of upper chord restraints 12'and 12'are in contact with each other. Since the upper chord buckling restraining member 8'is arranged at the end of the upper chord member 42, the gusset plate 7 for fixing the upper end side of the first diagonal member 4a is fixed to the pillar 5 and is fixed to the upper chord member 42. Not joined.

Focusing on one end side of the truss beam 41, when one of the upper chord member 42 and the lower chord member 3 receives a compressive force during an earthquake, the other receives a tensile force. Further, when the upper chord member 42 receives a tensile force on one end side of the truss beam 41, the lower chord member 3 receives a tensile force on the other end side of the truss beam 41. Since the ends of the pair of restraining materials 12 and 12 on the adjacent sides are in contact with each other, the contraction of the core material 11 or the upper chord core material 11'that receives the compressive force is hindered, but the upper chord core that receives the tensile force. The material 11'or the core material 11 is elongated. The energy at the time of an earthquake is absorbed by the extension of the core material 11 and the upper chord core material 11'which are alternately subjected to the tensile force. Further, since the center of the core material 11 and the upper chord core material 11'is covered with a pair of restraint materials 12, 12 and a pair of upper chord restraint materials 12', 12', respectively, the core material 11 and the upper chord core material 11'. 'Can prevent buckling in the center.

Although the description of the specific embodiment is completed above, the present invention can be widely modified without being limited to the above embodiment. The truss beam may be supported by a structural member of the building other than the pillar, for example, a beam or the like. The H-shaped steel used for the main body and core material of the lower chord material and the upper chord body and upper chord core material of the upper chord material uses a weak shaft, that is, a pair of flanges extend in the vertical direction and the web is horizontal. It may be arranged so as to extend in the direction.

1,21,31,41: Truss beam 2,42: Upper chord material 3,22,32: Lower chord material 4: Diagonal lumber 4a: First lumber 4b: Second lumber 5: Column (structural member)
6: Main body 8, 23, 33: Buckling restraint member 8': Upper chord buckling restraint member 10: Joint body 10': Upper chord joint body 11, 34: Core material 11': Upper chord core material 12: Restraint material 12' : Upper chord restraint material 13, 13': Filler material 35: 1st core material 36: 2nd core material

Claims (6)

A truss beam having an upper chord lumber, a lower chord lumber and a plurality of diagonal lumbers and supported by a pair of structural members.
The lower chord member has a main body portion having a long member and a buckling restraining member arranged so as to replace the main body portion in a part of a section of the lower chord member in the extending direction.
A pair of joint bodies in which the buckling restraint member is joined to the main body portion or the structural member and faces each other.
A core material whose both ends are fixed to the corresponding joint,
Each truss beam has a cylindrical shape through which the core material is inserted, and one end side has a pair of restraining materials fixed to the corresponding joint body. The buckling restraining member was arranged between the lower ends of the second and third slanted lumbers arranged second and third from the end of the truss beam among the plurality of slanted lumbers. The truss beam according to claim 1. The lower ends of the first and second slanted lumbers arranged first and second from the end of the truss beam among the plurality of slanted lumbers are joined to one of the pair of restraint members. The truss beam according to claim 1. The truss beam according to any one of claims 1 to 3, wherein the ends of the pair of restraining materials on the side close to each other are separated from each other. The buckling restraint member further comprises a filler that is filled in the pair of restraints and is not adhered to the core.
The core material has a first core material inserted through one of the pair of restraint materials and a second core material inserted through the other of the pair of restraint materials.
The truss beam according to claim 4, wherein the ends of the first core material and the second core material on the side close to each other protrude from the pair of restraint materials and are joined to each other. The upper chord member has an upper chord main body portion having a long member and an upper chord buckling restraining member arranged so as to replace the upper chord main body portion in a part of a section in the extending direction of the upper chord member.
The upper chord buckling restraining member
A pair of upper chord joints that are joined to the upper chord body or the structural member and face each other.
The upper chord core material whose both ends are fixed to the corresponding upper chord joints,
Each has a tubular shape through which the upper chord core material is inserted, and one end side has a pair of upper chord restraining materials fixed to the corresponding upper chord joint.
Claim 1 is characterized in that the ends of the pair of restraints on the side close to each other are in contact with each other, and the ends of the pair of upper chord restraints on the sides close to each other are in contact with each other. The truss beam according to any one of 3 to 3.

Images