JP2007224575A - Triple pipe seismic control brace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a triple pipe seismic control brace capable of efficiently absorbing a stress caused by tensile and compressive repeated axial forces without allowing the strength of an axial force tube to be lowered due to the general or local buckling even if the stress acts on the axial tube in earthquake and improved in the lowering of a stress absorbing capacity due to the sudden rise of the strength of the axial tube produced when the axial tube is largely deformed. <P>SOLUTION: In this triple pipe seismic control brace 10, auxiliary rigid tubes 14, 16 for stopping the buckling due to yielding of the axial force tube 12 are disposed concentrically with the axial tube 12 at an interval on both the inner and outer sides of a low yield point steel tube 20 side of the axial force tube 12 to which a structural steel tube 18 and a low yield point steel tube 20 are connected on the same axis. A plurality of slits 34 are formed in the low yield point steel tube 20 in the axial and circumferential directions. The plurality of slits 34 are axially long. The distance between the slits 34, 34 adjacent to each other in the circumferential direction is desirably longer than the axial length of the slit 34. The axial force tube may have a length adjusting mechanism. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a triple-tube seismic brace, and more particularly, even if stress due to repeated axial force of tension or compression is applied to an axial force tube due to an earthquake, the axial force tube is reduced in yield strength due to overall or local buckling. This is about a triple-control seismic brace that never happens.

  Conventionally, as a material for reducing the shaking of a building due to an earthquake, there is a tensile / compressed structural material provided with an axial force tube having an elastoplastic history characteristic. And as a countermeasure against the decrease in the proof stress of the axial force pipe due to the stress due to the repeated axial force during an earthquake, there is a double steel pipe type tensile / compressed structural material.

  For example, Patent Document 1 discloses an axial force tube in which a thick tube and a thin wall tube having a smaller thickness are coaxially joined, and an axial force tube for suppressing buckling of the axial force tube to the outside. There is disclosed a double steel pipe-type structural material composed of an outer tube arranged concentrically over the entire length on the outside. Patent Document 2 is composed of an axial force tube and an inner tube disposed concentrically over the entire length of the axial force tube in order to suppress buckling of the axial force tube to the inside. A double steel tube type structural material is disclosed.

  And according to what is shown in patent document 1 and patent document 2, when the stress due to the repeated axial force of tension or compression acts on the axial force tube due to the earthquake, the axial force tube deforms elastically and absorbs the stress. This can reduce the shaking of the building due to the earthquake.

  At this time, the one disclosed in Patent Document 1 can prevent the axial tube from buckling outward by the outer tube. Moreover, what is shown by patent document 2 can prevent that an axial force pipe tries to buckle inside by an inner cylinder pipe.

  However, these can prevent buckling to either the outside or the inside of the axial force tube by the outer tube or the inner tube, but cope with buckling to the other side at the same time. There was a problem that I could not. In addition, the outer tube and the inner tube are disposed over the entire length of the axial force tube, which increases the manufacturing cost. In order to solve these problems, a triple pipe seismic brace has been developed.

  For example, Patent Document 3 discloses a triple pipe seismic brace that solves the above problem. The structure will be described with reference to FIG. 6. A triple pipe seismic brace 60 includes a structural steel pipe 64 made of a general structural steel material, and a low yield point steel pipe 66 made of a low yield point steel material having a lower yield point. Are axially joined by a weld stop 68, and stiffening tubes 70 and 72 concentrically disposed on both the inside and the outside of the steel tube 66 side of the axial force tube 62. Have.

  According to the triple pipe seismic brace 60, when a stress due to repeated axial force of tension or compression acts on the axial force pipe 62 due to the earthquake, the low yield point steel pipe 66 of the axial force pipe 62 is elastically plastically deformed to absorb the stress. Therefore, the shaking of the building due to the earthquake can be reduced. At this time, the inner reinforcing tube 70 prevents the axial force tube 62 from buckling inward, and the outer reinforcing tube 72 prevents the axial force tube 62 from buckling outward. it can. Further, since the stiffening tubes 70 and 72 are disposed not on the entire length of the axial force tube 62 but on the low yield point steel tube 66 side, the manufacturing cost can be reduced.

Japanese Patent Laid-Open No. 11-193570 JP 2003-34983 A JP 2005-320688 A

  However, in the triple-tube seismic brace 60 shown in Patent Document 3, the strength reduction of the axial force pipe 62 is reduced by the fact that the stiffening pipes 70 and 72 on both sides constrain the overall buckling and local buckling of the axial force pipe 62. Although it is prevented, the low yield point steel pipe 66 is not particularly processed to disperse the buckled portion over the entire steel pipe, so that the buckling restraint of the axial force pipe 62 tends to be local. When the axial force tube 62 is largely deformed (for example, during a large earthquake), the stiffening tubes 70 and 72 and the axial force tube 62 are caused by local buckling restraint of the axial force tube 62 by the stiffening tubes 70 and 72. The strength of the seismic brace 60 suddenly increases due to the close contact, and the low yield point steel pipe 66 other than the close contact portion cannot be plastically deformed, and the stress due to the repeated axial force of tension or compression acting on the axial force tube due to the earthquake. There was a problem that was not absorbed.

  The problem to be solved by the present invention is that even if an axial force pipe is subjected to stress due to repeated tensile or compressive axial force due to an earthquake, the axial force pipe is subjected to the stress without lowering its proof stress due to overall or local buckling. An object of the present invention is to provide a triple-tube seismic brace that efficiently absorbs and improves a decrease in stress absorption capability due to a sudden increase in the proof stress of an axial force tube that occurs when the axial force tube undergoes large deformation.

  In order to solve the above problems, a triple pipe seismic brace according to the present invention includes a structural steel pipe made of a general structural steel material and a low yield point steel pipe made of a low yield point steel material having a lower yield point than that of the structural steel pipe. A stiffening tube that prevents a decrease in yield strength due to buckling of the axial force tube is concentric with the axial force tube at regular intervals on both the inside and outside of the low yield point steel tube side of the axial force tube that is coaxially joined. The low-yield point steel pipe of the axial force pipe is provided with a plurality of slit holes in the axial direction and the circumferential direction.

  In this case, the plurality of slit holes have a length in the axial direction longer than the circumferential length thereof, and a distance between the slit holes adjacent to the circumferential direction of the low yield point steel pipe than the axial length thereof. It is desirable that the low yield point steel pipe is provided so as to lengthen the length.

  The axial force tube may have a length adjusting mechanism.

  According to the triple pipe vibration control brace according to the present invention, since the stiffening pipes are concentrically arranged on both the inner side and the outer side of the low yield point steel pipe side of the axial force pipe, the entire buckling of the axial force pipe is performed. Can be restrained on both sides. At this time, since the stiffening tube is arranged at a constant interval from the axial force tube, the progress of local buckling can be prevented. As a result, when stress due to repeated axial force of tension or compression acts on the axial force tube due to an earthquake, it is possible to prevent the axial force tube from lowering its proof stress and efficiently absorb the stress.

  And the triple pipe damping brace which concerns on this invention is provided with the several slit hole in the axial direction and circumferential direction of the low yield point steel pipe of an axial force pipe. Therefore, when a stress due to repeated axial force of tension or compression acts on the axial force pipe due to an earthquake, the plurality of steel pipe portions between the slit holes are uniformly plastically deformed. As a result, the low yield point steel pipe of the axial force pipe can be yielded uniformly over the entire region in the axial direction and the circumferential direction.

  According to this, when the low yield point steel pipe of the axial force pipe is deformed greatly (compression deformation) due to a large earthquake or the like, the axial force pipe is buckled and restrained by the inner or outer stiffening pipe, but the deformation of the slit hole part This prevents the stiffening tube and the axial force tube from coming into close contact with each other. And even at the time of large deformation of the axial force pipe, it is possible to plastically deform the entire low yield point steel pipe and to absorb the stress caused by repeated axial force of tension and compression acting on the axial force pipe due to the earthquake. The effect can be demonstrated.

  In this case, a plurality of slit holes having a shape in which the length in the axial direction is longer than the circumferential length of the slit holes and the distance between the slit holes adjacent to each other in the circumferential direction is made longer than the axial length is low yielding. If a point steel pipe is provided, when the compressive stress due to an earthquake acts on the low yield point steel pipe of an axial force pipe, the slit hole collapses in the circumferential direction (plastically deforms) and the hole becomes smaller, and the stress is more efficiently handled. Can be absorbed.

  And if the axial force pipe has a length adjusting mechanism, this triple pipe seismic brace can be expanded and contracted, so the length adjustment caused by the error in mounting this triple pipe seismic brace on the building structure The problem is solved. In addition, the work process becomes easier as compared with other methods of adjusting the length by rotating the entire vibration control brace. Furthermore, since the entire triple pipe seismic brace can be expanded and contracted by rotating only the joint member of the length adjusting mechanism, it is not necessary to select a joining member when joining the triple pipe seismic brace and the building structure, It becomes possible to deal with various joining members such as clevis joints and bolt joints.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial sectional view showing an embodiment of a triple pipe seismic brace according to the present invention. FIG. 2 is an enlarged view of the low yield point steel pipe portion of the axial force pipe of the triple pipe vibration control brace shown in FIG. FIG. 3 is a view showing an example in which the triple pipe seismic brace shown in FIG. 1 is incorporated in a framework of a building structure. FIG. 4 is a partial cross-sectional view showing an embodiment of a triple pipe seismic brace having a length adjusting mechanism in an axial force pipe. FIG. 5 is a graph illustrating the effects of the triple pipe seismic brace according to the present invention.

  As shown in FIG. 1, a triple-tube seismic brace 10 according to an embodiment of the present invention is concentric at regular intervals on an axial force tube 12 that is a main structural material and both inside and outside of the axial force tube 12. It has a triple tube structure consisting of an inner stiffening tube 14 and an outer stiffening tube 16 arranged in a shape.

  The axial force pipe 12 is composed of a structural steel pipe 18 and a low yield point steel pipe 20 that are coaxially joined by a weld stopper 22. The axial force pipe 12 has one end on the structural steel pipe 18 side welded to the base 24a and the other end on the low yield point steel pipe 20 side similarly welded to the base 24b. Bolt joint members 28a and 28b are attached to the caps 24a and 24b, respectively.

The structural steel pipe 18 constituting the axial force pipe 12 is made of a general structural steel material. For example, a structural standard strength of 235, 325, 355, 385, 440 (N / mm ² ) is exemplified. can do. On the other hand, the low yield point steel pipe 20 is made of a low yield point steel material having lower rigidity and yield strength than the structural steel pipe. For example, the design standard strength is 80, 100, 120, 160, 225 (N / mm ² ). Can be illustrated.

  Inside the low yield point steel pipe 20 of the axial force pipe 12, an inner stiffening pipe 14 having a slightly smaller diameter than the low yield point steel pipe 20 is disposed concentrically with the low yield point steel pipe 20 at a constant interval. One end thereof is welded 30 to the base 24b. Further, on the outer side of the low yield point steel pipe 20 of the axial force pipe 12, an outer stiffening pipe 16 having a slightly larger diameter than the low yield point steel pipe 20 is concentric with the low yield point steel pipe 20 at a constant interval. One end thereof is also welded 32 to the base 24b. On the other hand, the other ends of the stiffening tubes 14 and 16 are not welded. Therefore, when an axial force is repeatedly applied to the triple pipe damping brace 10 due to an earthquake, the stress acts only on the axial force pipe 12. The stiffening tubes 14 and 16 may be steel tubes made of the same material as the structural steel tube 18 of the axial force tube 12.

  The constant interval referred to here is an interval that is uniformly provided to such an extent that the overall buckling and local buckling of the low yield point steel pipe 20 do not progress excessively. If the interval is too wide, the effect that the plastically deformed low yield point steel pipe 20 is buckled and restrained by the stiffening pipes 14 and 16 provided on both sides of the low yield point steel pipe 20 is reduced, and if the interval is too narrow, The low yield point steel pipe 20 is immediately buckled and restrained by sufficient plastic deformation to absorb the stress caused by the repeated axial force of tension and compression acting on the axial force pipe 12 due to the earthquake, and the effect of absorbing the stress. This is because of a decrease. Therefore, it may be a uniform interval that can sufficiently exhibit these effects.

  And in the triple pipe damping brace 10 which concerns on this embodiment, the low yield point steel pipe 20 of the axial force pipe 12 has a characteristic shape. Therefore, the shape will be described in detail with reference to FIG.

  As shown in FIG. 2, the low yield point steel pipe 20 of the axial force pipe 12 is provided with a plurality of slit holes 34, 34... Having seven in the axial direction and six in the circumferential direction. The slit holes 34, 34... Are elliptical through holes having a major axis in the axial direction, and are arranged at regular intervals along the axial direction and the circumferential direction. In the slit holes 34, 34..., The distance L 1 between one slit hole 34 adjacent to the circumferential direction of the low yield point steel pipe 20 and the other slit hole 34 is longer than the axial length L 2 of the slit hole 34. Is also formed to be long.

  The yield strength and deformation performance of the low yield point steel pipe 20 vary depending on the material and the diameter and thickness of the pipe. Therefore, the slit holes 34, 34... Formed in the low yield point steel pipe 20 are not limited to the shape and number described above, and have desired proof stress and deformation performance according to the material, the diameter and thickness of the pipe. As can be obtained, it can be determined by calculation.

Further, such slit holes 34, 34... Can be easily processed (perforated) in steel materials distributed in the market having design standard strengths of 80, 100, 120, 160, 225 (N / mm ² ). Etc.), and the yield strength and deformation performance can be freely adjusted according to the processing method. That is, the proof stress of the low yield point steel pipe 20 can be adjusted by changing the width and number of the slit holes 34 in the circumferential direction of the low yield point steel pipe 20, and the length and number of the slit holes 34 in the axial direction can be adjusted. By changing, the deformation performance of the low yield point steel pipe 20 can be adjusted.

  The triple-pipe seismic brace 10 having such a configuration can be attached to a building structure by being incorporated in a framework made up of columns and beams of the building structure. An example in which the triple pipe seismic brace 10 according to the present embodiment is incorporated in a framework of a building structure will be described with reference to FIG.

  As shown in FIG. 3, the frame surrounded by the pillar 38 and the beam 40 of the building structure 36 is provided with gussets 42 a and 42 b at one corner and at one corner and the other corner at a diagonal position, respectively. Yes. The triple pipe seismic brace 10 is installed between both gussets 42a and 42b by attaching bolt joint members 28a and 28b attached to both ends to the gussets 42a and 42b, respectively.

  At this time, due to construction errors when attaching the triple pipe vibration control brace 10 to the building structure 36, the length between both gussets 42a and 42b and the length between both bolt joint members 28a and 28b of the triple pipe vibration control brace 10 are difficult to match. Sometimes. In such a case, a triple pipe seismic brace having a length adjusting mechanism in the axial force pipe may be used.

  As a triple pipe vibration control brace having a length adjusting mechanism in the axial force pipe, for example, a triple pipe vibration control brace 44 shown in FIG. 4 can be exemplified. As shown in the figure, the triple pipe damping brace 44 includes an axial force pipe part A and a length adjusting part B. The axial force pipe portion A has an axial force pipe 12 which is a main structural material in which a structural steel pipe 18 and a low yield point steel pipe 20 are coaxially joined by a weld stopper 22 in the same manner as the triple pipe damping brace 10. The axial force pipe 12 has a triple pipe structure in which stiffening pipes 14 and 16 are concentrically arranged at regular intervals on both the inside and outside of the low yield point steel pipe 20 side. A base 24b is welded to the pipe end of the axial force pipe 12 on the low yield point steel pipe 20 side, and a bolt joint member 28b is attached to the base 24b.

  The length adjusting portion B is composed of a joint member 46 and a pair of screw members 48a and 48b. The joint member 46 includes a shaft joint 50 and male screw shafts 52 a and 52 b having a left and right reverse screw structure protruding from both ends of the shaft joint 50. The pair of screw members 48a and 48b have female screw holes 54a and 54b having a left and right reverse screw structure threaded on opposite surfaces thereof. The joint member 46 is interposed between the pair of screw members 48a and 48b, and the male screw shafts 52a and 52b of the shaft joint 50 are screwed into the female screw holes 54a and 54b of the pair of screw members 48a and 48b. ing.

  The length adjusting portion B is joined to the axial force tube portion A by welding 56 the structural steel pipe 18 of the axial force tube 12 to one screw member 48b, and is bolted via the other screw member 48a. It is joined to the member 28a.

  In this example, when the shaft joint 50 of the joint member 46 is rotated clockwise, the pair of screw members 48a and 48b are separated (approached) from each other, and the entire triple pipe vibration brace 44 is extended (shrinked), and the shaft joint 50 is When rotated counterclockwise, the pair of screw members 48a and 48b approach (separate) each other, and the entire triple pipe vibration brace 44 contracts (extends). In such a turnbuckle mechanism, if the screw structure of the pair of screw members is a reverse screw, and the screw structure of the joint member is also a reverse screw structure in accordance with the screw structure of the screw member, The length adjustment of the triple pipe vibration control brace can be made flexible by turning.

  Next, according to the example, in the triple pipe vibration control brace 10 according to the present embodiment, the action and effect when the low yield point steel pipe of the axial force pipe 12 is formed in the shape shown in FIG. 2 is compared with the conventional one. explain.

(Example)
Low yield point steel pipe “LY100” (φ172.8 × 8.5 mm, length 600 mm) with design standard strength 80 (N / mm ² ), length (axial direction) 50 mm, width (circumferential direction) 10 mm A test material X having seven elliptical slit holes in the axial direction and six in the circumferential direction was prepared. A tension-compression test was performed after arranging a stiffening tube at a predetermined interval (3.5 mm) on both the inner and outer sides of the test material X.

  In the tension-compression test, a tensile load is applied to the test material X. When the tensile deformation amount becomes 0.6 mm, a compressive load is applied in the opposite direction, and when the compressive deformation amount is also 0.6 mm, a tensile load is applied again. This time, when the amount of tensile deformation becomes 1.5 mm, a compressive load is applied to the opposite direction, and when the amount of compressive deformation becomes 1.5 mm, the tensile load is applied, and so on. A load is applied so that gradually increases, and the amount of deformation (0.6, 1.5, 3.0, 4.5, 6.0, 15, 30, 60 mm) in the axial direction of the test material X is stepped. The load required at that time was continuously measured. The result is shown in FIG.

(Comparative example)
The test material Y was a low yield point steel pipe “LY100” (φ172.8 × 8.5 mm, length 600 mm) with no slit holes. Similar to the test material X, after the stiffening pipes were arranged on both the inner and outer sides, a compression-tensile test was performed. The result is shown in FIG.

  As shown in FIG. 5A, in the embodiment, when the amount of deformation increases stepwise, the load required at that time also increases stepwise. The relationship between the amount of deformation at this time and the required load is that there is no sudden increase in the load, and the load is increasing regularly, as in the graph drawn in FIG. 5A. I understand. In particular, the load required when the amount of compressive deformation is 60 mm (about 1750 kN) is on a line extending straight from the load required when the amount of compressive deformation is 0 mm (about 1120 kN), and the amount of compressive deformation is up to 60 mm. It can be seen that there is no sudden increase in load.

  And when the state of the test material X when the amount of compressive deformation becomes 60 mm is observed, a plurality of steel pipe portions between the plurality of slit holes provided in the axial direction are in the axial direction and the circumferential direction. Was uniformly deformed (in a waveform).

  On the other hand, in the comparative example, as shown in FIG. 5B, in the first deformation stage (up to 30 mm compression deformation), as in the embodiment, the necessary load increases as the deformation amount increases stepwise. The graphs are gradually increasing, and the drawn graphs are similar. However, it can be seen that in the next deformation stage where the amount of compressive deformation is 30 mm, the load required to increase the amount of compressive deformation is rapidly increased (in the figure, the yield strength increasing portion). And when the state of the test material Y when the amount of compressive deformation became 38 mm was observed, the low yield point steel pipe was locally buckled restrained by the stiffening pipe, and the location was closely_contact | adhered.

  From the above results, in the conventional triple pipe seismic brace without multiple slit holes in the axial direction and circumferential direction of the low yield point steel pipe, the local buckling of the low yield point steel pipe during large deformation of the axial force pipe A sudden increase in proof stress accompanying restraint will occur. In other words, when a large deformation occurs in the low yield point steel pipe of an axial force pipe due to a large earthquake, etc., the low yield point steel pipe cannot be sufficiently plastically deformed, and the stress due to repeated axial forces of tension and compression acting on the axial force pipe due to the earthquake. It is thought that it becomes impossible to absorb the water.

  On the other hand, by assuming that a plurality of slit holes 34, 34... Are provided in the axial direction and the circumferential direction of the low yield point steel pipe 20 like the triple pipe vibration control brace 10 according to the present embodiment. Even when a large deformation occurs in the low yield point steel pipe 20 of the axial force pipe 12 due to a large earthquake or the like and the axial force pipe 12 is buckled and restrained by the stiffening pipes 14 and 16, stiffening is achieved by deformation of the slit hole 34 portion. In order to prevent the tubes 14 and 16 and the axial force tube 12 from coming into close contact with each other, the entire low yield point steel tube 20 can be plastically deformed, and due to repeated axial forces of tension and compression acting on the axial force tube 12 due to an earthquake. The desired effect of absorbing stress can be exhibited.

  And according to the triple pipe seismic brace 10 comprised as mentioned above, the stiffening pipe | tubes 14 and 16 are arrange | positioned concentrically both on the inner side of the low yield point steel pipe 20 side of the axial force pipe 12, and the outer side. Therefore, as shown in FIG. 3, in the state where the building structure 36 is incorporated in the frame surrounded by the columns 38 and the beams 40, the stress due to the repeated axial force of tension or compression is applied to the axial force tube 12 due to the earthquake. Can act to restrain the entire buckling of the axial force tube 12 by the stiffening tubes 14 and 16. At this time, since the stiffening tubes 14 and 16 are arranged at a constant interval from the axial force tube 12, the progress of local buckling can be prevented. As a result, when stress due to repeated axial force of tension or compression is applied to the axial force tube 12 due to an earthquake, the axial force tube 12 can be prevented from decreasing its proof stress, and the stress can be absorbed efficiently.

  Further, the triple-tube seismic brace 10 according to the present embodiment has an axial length longer than the circumferential length of the slit holes 34, 34..., And the slit holes 34 adjacent in the circumferential direction rather than the axial length. -Since the low yield point steel pipe 20 is provided with a plurality of slit holes 34, 34 ... that have a shape that increases the distance between the slit holes 34, the compressive stress caused by the earthquake is applied to the low yield point steel pipe 20 of the axial force pipe 12. When acted, the slit holes 34, 34... Are crushed in the circumferential direction (plastically deformed) and the holes become smaller, so that the stress can be absorbed more efficiently.

The low yield point steel pipe 20 constituting the axial force pipe 12 of the triple pipe vibration control brace 10 is a steel material distributed in the market having a design standard strength of 80, 100, 120, 160, 225 (N / mm ² ). Yes, by applying simple processing to this, it is possible to freely adjust the proof stress and deformation performance, so it is possible to provide a vibration control member rich in variations.

  Further, as shown in FIG. 4, when the axial force pipe 12 has a length adjusting mechanism, the triple pipe vibration control brace 44 can be expanded and contracted. Therefore, when the triple pipe vibration control brace 44 is attached to the building structure, The length adjustment problem caused by enforcement errors is solved. In addition, the work process becomes easier as compared with other methods of adjusting the length by rotating the entire vibration control brace. Further, since the entire triple pipe seismic brace 44 can be expanded and contracted by rotating the shaft joint 50 of the joint member 46 of the length adjusting mechanism B, a joining member for joining the triple pipe seismic brace 44 and the building structure is provided. It does not have to be selected, and can be applied to various joining members such as clevis joints and bolt joints.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment at all, A various change is possible in the range which does not deviate from the summary of this invention.

  For example, the shape of the slit hole formed in the low yield point steel pipe 20 of the axial force pipe 12 is not limited to an elliptical shape. In addition, it may be round. Further, the relationship between the axial length of the slit holes and the distance between adjacent slit holes in the circumferential direction is not limited to that shown in FIG. If a plurality of slit holes are formed in the axial direction, it is easy to yield at a plurality of steel pipe portions between the slit holes, so that it can be yielded uniformly in the entire axial direction, and a plurality of slits also in the circumferential direction. This is because if the holes are formed, it is possible to uniformly yield the entire circumferential direction.

  Moreover, the length adjustment part B is not limited to what is shown by FIG. For example, there is no problem even if a female screw hole is formed in the joint member and a male screw shaft is formed in the screw member.

  Furthermore, the joining members attached to both ends of the triple pipe seismic brace are not limited to the bolt joining members 28a and 28b, and may be other joining members such as a clevis joint.

  The triple-pipe seismic brace according to the present invention can be used for various building structures such as steel-framed reinforced concrete architecture, reinforced concrete architecture, steel-framed architecture, and civil engineering structures if necessary.

It is a partial sectional view showing one embodiment of the triple pipe seismic brace concerning the present invention. It is an enlarged view of the low yield point steel pipe part of the axial force pipe of the triple pipe damping brace shown in FIG. It is the figure which showed an example in which the triple pipe control brace shown by FIG. 1 is integrated in the framework of a building structure. It is a partial sectional view showing one embodiment of the triple pipe seismic brace which has a length adjustment mechanism in an axial force pipe. It is a graph explaining the effect of the triple pipe vibration control brace which concerns on this invention. It is a figure showing an example of the structure of the conventional triple pipe damping brace.

Explanation of symbols

10,44 Triple pipe seismic brace 12 Axial force pipe 14 Inner stiffening pipe 16 Outer stiffening pipe 18 Structural steel pipe 20 Low yield point steel pipe 34 Slit hole 36 Building structure

Claims (3)

  A structural steel pipe made of a general structural steel material and a low yield point steel pipe made of a low yield point steel material having a lower yield point than that of the structural steel pipe are coaxially joined to the low yield point steel pipe side of the axial force pipe. A stiffening tube that prevents a decrease in yield strength due to buckling of the axial force tube is disposed on both the inner side and the outer side, concentrically with the axial force tube at a predetermined interval, and the low yield point steel tube of the axial force tube. Has a plurality of slit holes in the axial direction and circumferential direction.   The plurality of slit holes have a length in the axial direction longer than a length in the circumferential direction, and a distance between the slit holes adjacent to the circumferential direction of the low yield point steel pipe is made longer than the length in the axial direction. The triple pipe seismic brace according to claim 1, wherein the triple pipe seismic brace is provided on the low yield point steel pipe.   The triple pipe seismic brace according to claim 1 or 2, wherein the axial force pipe has a length adjusting mechanism.

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