JP2019183579A - Truss beam - Google Patents

Abstract

To provide a truss beam in which a buckling restraining member whose neck folding buckling is prevented is easily disposed in a part of a chord member and in which a frame can be handled just like a full web member.SOLUTION: A truss beam (1) includes an upper chord member (2), a lower chord member (3), and a plurality of diagonal members (4). A part of the lower chord member (3) is constituted of a buckling restraining member (8). The buckling restraining member (8) comprises: a pair of joint bodies (10, 10) joined to a main body portion (6) of the lower chord member (3); a core material (11) whose end portions are respectively fixed to the corresponding joint body (10); a pair of restraining members (12, 12) which respectively has a cylinder shape through which the core material (11) is inserted and whose one end side is fixed to the corresponding joint body (10); and a filler (13) filled in the restraining member (12) so as not to adhere to the core material (11).SELECTED DRAWING: Figure 1

Description

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

  Truss beams are composed of individual members of string material and diagonal material, and are members that resist the axial force generated in individual members in the elastic region. Generally, a string material is a straight line or a curved line, and an oblique material is a straight line. There are many.

  The deformability of a steel member is determined by a structural characteristic coefficient (hereinafter referred to as “Ds value”) mainly depending on the width-thickness ratio of the individual material, and is applied to a single material satiety member such as H-shaped steel. The greater the deformation performance, the smaller the Ds value and the lower the design seismic force. However, it cannot be applied to the width-thickness ratio of the individual members of the truss beam, and there is no member type of the truss beam itself. Therefore, unless special consideration is made at this time, a large Ds value may be set for the design of the truss beam. It is customary. Therefore, when a truss beam is provided, it is necessary to design it as a “building” with poor deformation performance with a large seismic force (large Ds value), including not only the truss beam but also other columns and beams. It was an uneconomical design.

  Non-Patent Document 1 describes a history that is stabilized in the entire truss frame by replacing a plasticizing member with a buckling restraining member or a member having stable hysteresis characteristics in a flat truss member incorporated in a ramen frame. It is described that it is possible to design that gives characteristics, and it is possible to handle the frame in the same manner as a satiety material (H-shaped steel etc.) without considering the influence of individual material buckling.

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

JP 2005-146773 A

“Design Guidelines for Buckling of Steel Structure” by Architectural Institute of Japan, Architectural Institute of Japan, November 2009

  However, the buckling restraint member described in Patent Document 1 is used as a vibration-damping brace that is disposed obliquely in the frame structure of a building column and beam. Moreover, since both ends of the core material are exposed from the steel pipe, there is a case where the core material is folded at the boundary between the portion located in the steel pipe and the portion exposed from the steel pipe, that is, the neck is bent. .

  In view of such a problem, the present invention provides a truss beam that can easily arrange a buckling restraining member that is prevented from buckling buckling in a part of a chord material and can handle a frame in the same manner as a filling material. The purpose is to provide.

  A truss beam according to at least some embodiments of the present invention includes an upper chord member (2, 42), a lower chord member (3, 22, 32), and a plurality of diagonal members (4). 5, 5) is a truss beam (1, 21, 31, 41) supported by a main chord (6) having a long material and a part of the extending direction of the lower chord And a buckling restraining member (8, 23, 33) disposed so as to replace the main body portion in the section, and the buckling restraining member is joined to the main body portion or the structural member to face each other 1 A pair of joined bodies (10, 10), a core material (11, 34) fixed to the joined body corresponding to both ends thereof, and a cylindrical shape through which the core material is inserted, respectively, correspond to one end side And a pair of restraining members (12) fixed to the joined body.

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

  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 diagonal members. The second and third diagonal members (4b) and (4c) are arranged between the lower ends of the second and third diagonal members (4c).

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

  In the first configuration, the truss beam (21) according to at least some embodiments of the present invention is arranged first and second from the end of the truss beam among the plurality of diagonal members. The lower ends of the first diagonal member (4a) and the second diagonal member (4b) are joined to one of the pair of restraining materials.

  According to this configuration, the first and second diagonal members are joined to one of the pair of restraining members, and after being formed as a truss, the end portion having the shortest section length is most easily plasticized in the lower chord material. It is possible to arrange the buckling restraining member at the same time and to ensure a large length of the plastic region (core material).

  The truss beams (1, 21, 31) according to at least some embodiments of the present invention may be configured such that, in any of the above-described configurations, the ends of the pair of restraining members adjacent to each other are separated from each other. It is characterized by that.

  According to this configuration, the energy of the earthquake can be efficiently absorbed by the expansion and contraction of the core material during the earthquake.

  In the truss beam (31) according to at least some embodiments of the present invention, in the above configuration, the buckling restraining member (33) is filled in the pair of restraining materials and is not attached to the core material. It further has a filler (13), and the core (34) is inserted into the first core (35) inserted into one of the pair of restraints and the other of the pair of restraints. A second core member (36), and the adjacent ends of the first core member and the second core member protrude from the pair of restraining members and are joined to each other. It is characterized by.

  According to this structure, since the 1st and 2nd core material can mutually be joined after injection | pouring of a filler, the workability | operativity of a filler is improved. Moreover, the dimension of a buckling restraining member can be adjusted by adjusting the distance between a 1st and 2nd core material.

  In the truss beam (41) according to at least some embodiments of the present invention, in any of the first to third configurations, the upper chord member (42) is an upper chord body portion (43) having a long member. And an upper chord buckling restraining member (8 ') arranged so as to replace the upper chord main body in a part of the extending direction of the upper chord material, the upper chord buckling restraining member being the upper chord buckling restraining member. A pair of upper chord joints (10 ') joined to the main body or the structural member and facing each other, and an upper chord core (11') having both ends fixed to the corresponding upper chord joints, A pair of upper chord restraining members (12 ′, 12 ′) fixed to the corresponding upper chord joined body, one end side of which has a cylindrical shape through which the upper chord core member is inserted, The ends on the sides close to each other are in contact with each other, and the pair of upper chord restraining members And an end portion of the side close to the stomach is in contact with one another.

  According to this configuration, the core material and the upper chord core material can absorb energy at the time of an earthquake by alternately extending, and the center of the core material and the upper chord core material has a pair of restraining material and a pair of upper chord restraining material, respectively. Therefore, buckling in the center of the core material and the upper chord core material can be prevented.

  According to the present invention, it is possible to provide a truss beam capable of easily arranging a buckling restraining member in which neck buckling is prevented in a part of a chord material and handling a frame in the same manner as a satiety material. .

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

  The upper chord material 2 and the lower chord material 3 are arranged in parallel to each other substantially 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 the H-shaped steel is used for the entire upper chord material 2 and the main body portion 6 of the lower chord material 3, a long steel material such as another shape steel or a steel pipe may be used. The H-section steel used for the entire upper chord member 2 and the main body 6 of the lower chord member 3 is arranged such that a pair of flanges face each other in the vertical direction and the web is along a vertical plane. Both ends of the upper chord member 2 and the lower chord member 3 are rigidly connected or pin-connected to the corresponding pillars 5 respectively.

  As the plurality of diagonal members 4 are directed from one end side in the extending direction of the truss beam 1 to the other end side, the diagonal members 4 are alternately arranged in the diagonally downward direction and in the diagonally upward direction. When a plurality of diagonal members 4 are 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. 4c and the 4th diagonal material 4d, and when showing an unspecified thing or the whole, it is only written as the diagonal material 4. Each diagonal member 4 is made of a long steel material such as an H-shaped steel or a pair of groove-shaped steels arranged in parallel to 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 4 a is rigidly or pin-joined to the upper chord member 2 and the column 5 via the gusset plate 7. In the two diagonal members 4, 4 whose upper end sides are adjacent to each other like the second diagonal member 4b and the third diagonal member 4c, these upper end sides are rigidly connected or pin-connected to each other via a common gusset plate 7. In addition, the upper chord member 2 is rigidly connected or pin-bonded. Further, in the two diagonal members 4, 4 whose lower end sides are adjacent to each other like the first diagonal member 4a and the second diagonal member 4b, these lower end sides are rigidly connected or pinned to each other via a common gusset plate 7. In addition to being joined, the lower chord material 3 is rigidly joined or pin joined. The upper chord member 2, the lower chord member 3, and the diagonal member 4 are fastened to the gusset plate 7 by bolts and nuts (not shown).

  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 material 3 that is easily plasticized. The section that is most easily plasticized is a section from the joint 9 to the column 5 of the plurality of diagonal members 4 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. However, the length of this section is from the lower end of the first diagonal member 4a and the lower end of the second diagonal member 4b to the lower chord member 3 at the lower end of the third diagonal member 4c and the lower end of the fourth diagonal member 4d. This is about half the length of the section to the joint 9 to the lower chord material 3, and there is a possibility that the length necessary for the buckling restraining member 8 cannot be secured. Therefore, in the first embodiment, the buckling restraining member 8 is formed by connecting 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 arrange | positions in the area to the junction part 9 with a lower end.

  The buckling restraining member 8 is fixed to the pair of joined bodies 10 and 10 which are joined to the main body 6 and opposed to each other, and both ends are fixed to the pair of joined bodies 10 and 10 so that the lower chord member 3 extends. A pair of constraining members 12 each having a core 11 arranged so as to be aligned with the main body portion 6 in a direction, each having a cylindrical shape through which the core 11 is inserted, and one end fixed to the corresponding joined body 10; 12 and the pair of restraining materials 12 and 12 are filled, and the filling material 13 is not attached to the core material 11.

  The joined body 10 is made of a steel flat plate. One end side of the core material 11 and the restraint material 12 is fixed to the joined body 10 by welding or the like. A main body part side joined body 14 made of a steel flat plate is provided at an end part of the main body part 6 joined to the buckling restraining member 8, and the main body part side joined body 14 has a main part of the main body part 6. It is fixed to the H-shaped steel to be constructed by welding or the like. Since the joined body 10 and the body portion side joined body 14 are fastened by a fastener 15 such as a bolt and a nut in a state where they are in contact with each other, both ends of the buckling restraining member 8 are joined to the body portion 6. ing.

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

  Each restraint material 12 consists of steel pipes, such as a square steel pipe. The adjacent ends of the pair of restraining members 12 and 12 are separated from each other. A value obtained by dividing the 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 adjacent ends of the pair of restraining members 12 and 12 may be deformed so that they are in contact with each other (the separation length is set to 0). The bending restraining member 8 is a tensile yield type.

  The filler 13 is made of mortar or the like. The filler 13 is formed by applying an anti-adhesive agent such as a mold release material, oil paint, or asphalt to a portion of the core material 11 located in the pair of restraining materials 12, 12. Filled in. Therefore, the filler 13 is not attached to the core material 11. The pair of restraining materials 12 and 12 and the filler 13 prevent the core material 11 from buckling. The core material 11 may be prevented from buckling only by the pair of restraining materials 12 and 12 without providing the filler 13.

  The core member 11 is prevented from buckling by the pair of restraining members 12 and 12 and the filler material 13 and can be expanded and contracted in the extending direction because the filler material 13 is not attached. Therefore, the buckling restraining member 8 can stably absorb energy such as an earthquake. In addition, since the buckling restraining member 8 is disposed at the portion of the lower chord material 3 that is easily plasticized, the truss beam 1 can handle the frame in the same manner as the satiety material without considering the influence of individual material buckling. That is, by improving the deformation capacity of the truss beam 1, the Ds value at the time of calculating the required horizontal proof stress 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, 12 and a filler 13, neck buckling of the buckling restraining member 8 and local buckling of both ends of the core material 11 occur. Can be prevented. In addition, the central portion of the core material 11 not covered with the pair of restraining materials 12 and 12 and the filler material 13 has a gentle change in shape as compared with the conventional buckling-prone portion, so that the force is smoothly applied. It is transmitted and hardly buckled.

  The buckling restraining member 8 has a joined body 10 in which the end of the core material 11 and the end of the restraining material 12 are fixed to one surface. Therefore, the buckling restraining member 8 can be easily attached to the main body 6 by fixing the pair of joined bodies 10 and 10 to the main body 6. Moreover, since the general shape steel currently distribute | circulated in the market can be used for the core material 11 and a pair of restraint materials 12 and 12, the increase in cost can be suppressed.

  A truss beam 21 according to the second embodiment will be described with reference to FIG. In the description, the description of the configuration common to the first embodiment is omitted and the same reference numeral is given.

  The lower chord member 22 of the truss beam 21 has a main body 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. As in the first embodiment, the buckling restraining member 23 includes a pair of joined bodies 10 and 10, a single core member 11, a pair of restraining members 12 and 12, and a filler 13.

  One of the pair of restraining members 12, 12 is fixed to the column 5 via the joined body 10 on one end side which is the end side of the buckling restraining member 23, and the other end which is the center side of the buckling restraining member 23. On the side, the lower end sides of the first diagonal member 4a and the second diagonal member 4b are fixed via a gusset plate 7. The other of the pair of restraining members 12, 12 is fixed to the H-section steel constituting the main body portion 6 via the joined body 10 and the main body portion side joined body 14 on one end side which is the end portion side of the buckling restraining member 23. Has been.

  Thus, by fixing the lower end side of the first and second diagonal members 4a, 4b to one of the restraining members 12 via the gusset plate 7, the first and second diagonal members 4a, 4b, the lower chord member 3, and The buckling restraining member 8 can be arranged so as to straddle the joint 9. Therefore, it is possible to arrange the buckling restraining member 23 at the end portion having the short section length, while ensuring the large length of the core material 11 as the plastic region, although it is most easily plasticized in the lower chord member 3 after being formed as a truss. Can do. Note that the lower end sides of the first and second diagonal members 4 a and 4 b may be fixed to the other restraining member 12.

  A 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 includes a main body portion 6 and a buckling restraining member 33. The buckling restraining member 33 has a pair of joined bodies 10 and 10, a pair of restraining materials 12 and 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 member 34 is fixed to one of the pair of joined bodies 10 and 10 on one end side, and the first core member 35 inserted into the restraining member 12 fixed to the joined body 10 and 1 on one end side. A second core member 36 that is fixed to the other of the pair of bonded bodies 10 and 10 and that is inserted through the restraint member 12 fixed to the bonded body 10. The 1st and 2nd core materials 35 and 36 consist of long steel materials, such as H section steel, respectively. The other end sides of the first and second core members 35 and 36 protrude from the restraint member 12 and are joined to each other. The other end sides of the first and second core members 35 and 36 are joined to each other by being fastened by a fastener 38 such as a bolt and a nut together with a steel joint plate 37 disposed so as to be in contact with both. The

  The first and second core members 35 and 36 can be joined to each other after the filler 13 is injected into each of the restraining members 12. Therefore, the workability of the filler 13 is improved. In addition, in order to join the first and second core members 35 and 36, it is necessary to increase the distance between the ends of the pair of restraining members 12 and 12 that are close to each other compared to the first embodiment. . In this section, the buckling restraint of the core member 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 is to 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 set according to the construction error. By adjusting, the dimension of the buckling restraining member 33 can be adjusted.

  With reference to FIG. 6, the truss beam 41 according to the fourth embodiment will be described. In the fourth embodiment, the upper chord member 42 is an upper chord body portion 43 substantially made of H-shaped steel, and an upper chord buckling restraining member arranged so as to be aligned with the upper chord body portion 43 in the extending direction of the upper chord member 42. 8 '. In other words, in a part of the upper chord member 42, the member constituting the upper chord body 43 is replaced with the upper chord buckling restraining member 8 ′. The upper chord buckling restraining member 8 'has a pair of upper chord joints 10', 10 ', an upper chord core member 11', a pair of upper chord restraining members 12 ', 12' and a filler 13 ', Each of the lower chord members 3 has a configuration corresponding to the pair of joined bodies 10 and 10, the core member 11, the pair of restraining members 12 and 12, and the filler 13. The buckling restraining member 8 of the lower chord member 3 is disposed below the second and third diagonal members 4b and 4c, as in the first embodiment. The upper chord buckling restraining member 8 'is disposed above the first and second diagonal members 4a, 4b, one upper chord joined body 10' is joined to the column 5, and the other upper chord joined body 10 'is a main body portion. It is joined to the upper chord body part 43 via the main body side upper chord joint body 14 ′ having the same configuration as the side joint body 14. The adjacent ends of the pair of restraining members 12 and 12 are in contact with each other, and the adjacent ends of the pair of upper chord restraining members 12 ′ and 12 ′ are in contact with each other. Since the upper chord buckling restraining member 8 ′ is disposed at the end of the upper chord member 42, the gusset plate 7 for fixing the upper end side of the first diagonal member 4 a is fixed to the column 5, 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 members 12, 12 that are close to each other 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 prevented, but the upper chord core that receives the tensile force. The material 11 ′ or the core material 11 extends. When the core material 11 and the upper chord core material 11 ′ that alternately receive the tensile force are elongated, the energy at the time of the earthquake is absorbed. Further, since the centers of the core material 11 and the upper chord core material 11 'are respectively covered with a pair of restraining materials 12, 12 and a pair of upper chord restraining materials 12', 12 ', the core material 11 and the upper chord core material 11 Can prevent buckling at the center of '.

  Although the description of the specific embodiment is finished as above, the present invention is not limited to the above embodiment and can be widely modified. The truss beam may be supported by a structural member of the building other than the pillar, such as a beam. The H-shaped steel used for the lower chord material main body and core material, and the upper chord material upper chord body portion and upper chord core material uses a weak shaft, that is, a pair of flanges extend vertically and the web is horizontal. You may arrange | position so that it may extend in a direction.

1, 21, 31, 41: truss beam 2, 42: upper chord material 3, 22, 32: lower chord material 4: diagonal material 4a: first diagonal material 4b: second diagonal material 5: pillar (structural member)
6: Main body parts 8, 23, 33: Buckling restraint member 8 ': Upper chord buckling restraint member 10: Joint 10': Upper chord joint 11, 34: Core material 11 ': Upper chord core material 12: Restraint material 12' : Upper chord restraining material 13, 13 ': Filler 35: First core material 36: Second core material

Claims (6)

A truss beam having an upper chord member, a lower chord member and a plurality of diagonal members and supported by a pair of structural members,
The lower chord material has a main body portion having a long material, and a buckling restraining member arranged so as to replace the main body portion in a partial section in the extending direction of the lower chord material,
A pair of joined bodies in which the buckling restraining member is joined to the body portion or the structural member and faces each other;
A core member fixed to the joined body corresponding to both ends, and
Each of the truss beams has a cylindrical shape through which the core member is inserted, and has a pair of restraining members fixed to the corresponding joined body on one end side.   The buckling restraining member is arranged between the lower ends of the second diagonal member and the third diagonal member arranged second and third from the end of the truss beam among the plurality of diagonal members. The truss beam according to claim 1.   Of the plurality of diagonal members, the lower ends of the first diagonal member and the second diagonal member arranged first and second from the end of the truss beam are joined to one of the pair of restraining members. The truss beam according to claim 1.   The truss beams according to any one of claims 1 to 3, wherein end portions of the pair of restraining members on the side close to each other are separated from each other. The buckling restraining member is further filled with the pair of restraining materials, and further has a filling material not attached to the core material;
The core member has a first core member inserted into one of the pair of restraining members and a second core member inserted into the other of the pair of restraining members,
5. The truss beam according to claim 4, wherein ends of the first core member and the second core member that are close to each other protrude from the pair of restraining members and are joined to each other. The upper chord material has an upper chord body portion having a long material, and an upper chord buckling restraining member arranged so as to replace the upper chord body portion in a partial section in the extending direction of the upper chord material,
The upper chord buckling restraining member is
A pair of upper chord joints joined to the upper chord body or the structural member and facing each other;
An upper chord core material fixed to the upper chord joined body corresponding to both ends, and
Each has a cylindrical shape through which the upper chord core material is inserted, and one end side has a pair of upper chord restraining members fixed to the corresponding upper chord joined body,
2. The ends of the pair of restraining members adjacent to each other are in contact with each other, and the ends of the pair of upper chord restraining members in contact with each other are in contact with each other. The truss beam as described in any one of -3.

Images