JP2008196163A - Seismic control stud - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simply-attachable seismic-control stud which includes a hysteretic damper capable of exerting a sufficient function, while having a simple structure. <P>SOLUTION: This seismic control stud comprises a pair of upper and lower base plates, a pair of a stud head portion and a stud base portion, which are protruded in mutually opposed directions from the respective base plates, and a shock absorbing damper which has opposed ends connected to a leading end of the stud head portion and that of the stud base portion, respectively. Both the stud head portion 6 and the stud base portion 8 are formed of at least vertical flat steel plates 10 parallel to each other, and the damper 14 is formed of at least a steel corrugated sheet 16 which has a ridge line of each corrugation oriented in a horizontal direction parallel to the vertical flat plate 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a seismic control column.

  Corrugated steel sheet that resists in-plane bending and shearing force but does not resist vertical axial force and out-of-plane bending force between a pair of upper and lower base plates for attachment to the beam Is known in which the wave is provided in the horizontal direction (Patent Document 1).

  In addition, when installing a damping member between the beams, the concrete hanging wall and waist wall protrude from both beams in the direction facing each other, and the damping member is fixed between them to improve the vibration damping capability. It is known to increase (Patent Document 2).

FIG. 3 of Patent Document 1 described above also discloses a structure in which corrugated steel plates are provided between a concrete hanging wall and a waist wall protruding from upper and lower beams.
JP 2006-37581 A Japanese Patent No. 3807360

    However, if these hanging walls and waist walls are made of concrete like the studs in FIG. 3 of Patent Document 1, these members may be damaged depending on the scale of the earthquake, and these members are manufactured and attached. However, it takes time and effort.

    An object of the present invention is to provide a seismic control column that includes a hysteretic damper that can exhibit a sufficient function while having a simple structure, and that can be easily attached.

The first means is a seismic control pillar,
A pair of upper and lower base plates;
A pair of column heads and column bases projecting in a direction facing each other from each base plate;
A vibration absorbing damper in which the opposite ends are connected to the tops of these column heads and column bases, and
In the seismic control pillar consisting of
The column heads 6 and the column bases 8 are at least steel vertical flat plates 10 parallel to each other,
The vibration absorbing damper 14 is formed by a corrugated plate 16 made of steel in which at least the ridges of each wave are oriented in the horizontal direction parallel to the vertical flat plate 10.

In this means, as a means for connecting the corrugated vibration absorbing damper and the base plate, the column head and the column base are formed of at least a vertical steel plate. Since it is a vertical flat plate, it can be superposed on corrugated plates like ordinary steel plates or simply connected using a joint plate, and can be easily replaced during repairs after an earthquake. Even if the connection location is broken by an earthquake, it is possible to re-weld as an emergency measure. In addition, when a force exceeding the limit is applied to a connecting portion made of concrete (such as the above-mentioned waist wall), the strength of the connecting portion is significantly reduced. On the other hand, since a steel vertical flat plate has toughness, even if it is bent by an earthquake, its strength does not drop so much. Therefore, even if there is an aftershock after repairing after a major earthquake, it can sufficiently counter the seismic force. The advantages of the present invention will be further described later.
The “seismic absorption damper” is to impart damping performance to the structure by energy consumption during the earthquake and suppress excessive relative displacement between the ground and the superstructure during the earthquake. Here, a premise matter related to the feature of the present invention will be described. The damper of the present invention is a hysteretic damper and uses energy consumption associated with a deformation performance. FIG. 9A illustrates the deformation history in a graph in which the horizontal axis represents the deformation angle and the vertical axis represents the horizontal overload. The curve representing the history draws a spindle-shaped locus at the stage beyond the yield point, and consumes energy according to the area of the spindle. Furthermore, the damper of the present invention is a plate-like damper, which resists deformation in the in-plane direction of the plate but does not resist deformation in the out-of-plane direction. As this type of damper, there are one using a flat plate (flat steel plate) and one using a corrugated plate (corrugated steel plate).

    When flat steel plate is used as a vibration absorbing damper, a vertical flat plate joined to the vibration absorbing damper is formed by forming a tension field between the diagonals of the plate when subjected to shear stress and significantly increasing the yield strength after shear yielding. In addition, there is a disadvantage that the damage to the beam member joined to the vertical plate is increased, and the resistance to the seismic force of the entire frame is weakened. On the other hand, in the present invention, since the corrugated plate is used as the vibration absorbing damper, a tension field is not formed between the diagonals of the plate, so that there is little increase in yield strength after shear yielding, and such inconvenience does not occur.

  As described above, the “corrugated plate” has a function of shear yielding and absorbing energy in the event of an earthquake. The corrugated plate transmits a shearing force, but the yield strength is not increased by the axial deformation acting on the damper due to the accordion effect. For the corrugated plate, it is preferable to use a steel material having a strength suitable for the design, such as low yield point steel, ordinary steel, or high strength steel. Further, some corrugated steel plates use steel materials having different strengths.

  “Column head” and “column base” are spacer members (or support bases) that support the damper by interposing between the beam and the top and bottom ends of the vibration absorbing damper whose vertical width is shorter than the distance between beams. As a function. By using these members, the deformation angle of the damper with respect to a certain vibration width can be increased, and the vibration damping performance can be enhanced. As described above, in the conventional technique, the column head and the column base are formed of a concrete vertical wall and a waist wall.

    Since these walls are concrete blocks, it is advantageous when resisting any lateral force. However, since the corrugated steel damper of the present invention described above hardly resists deformation in the out-of-plane direction, even if only the column head and the column base, which are the foundations of the damper, have resistance in the out-of-plane direction of the damper. has no meaning. The only disadvantage is that it is bulky and increases in weight. Therefore, column heads and column bases of flat steel plates have been proposed as slim support bases corresponding to corrugated steel plate dampers.

    The “base plate” can be attached to a large beam in a frame composed of columns and large beams as shown in FIG. Moreover, you may make it install between a small beam and a small beam, and a slab and a slab.

    As a second means, the vertical flat plate 10 has elasticity to such an extent that it can be rocked and deformed in the plate thickness direction by earthquake motion.

  By doing so, even if subjected to vibration in the thickness direction, there is room for deformation as a vertical flat plate in that direction, so that it is possible to prevent an excessive load from being applied to the corrugated plate.

The third means includes the first means or the second means, and the first flange 12 is provided at both ends of the vertical plate 10 of the column head 6 and the column base 8 in the horizontal direction, and the vibration absorbing damper 14 is provided. A second flange 18 is provided on each side of the corrugated plate 16 in the horizontal direction, and the first and second flanges 12 and 18 are joined to each other.

  By doing in this way, the connection operation of a vibration absorption damper, a column head, and a column base becomes easy. The first and second flanges resist bending corresponding to the shearing force input to the corrugated plate.

The invention according to the first means has the following effects.
○ Since a corrugated plate made of steel is used as a vibration absorbing damper, a large drop in yield strength will not occur even after experiencing the maximum yield strength.
○ Since the vertical flat plate 10 is connected to the top and bottom of the corrugated plate 16 that is the vibration absorbing damper 14, it is possible to control the deformation at the time of shear yielding, and it has a simple structure consisting of a plurality of plate portions, but has a hysteretic shape. Demonstrates sufficient performance as a damper.
○ When flat steel plates are used as a means of seismic control, there is a disadvantage that when a shear stress is applied, a tensile field is formed between the diagonals of the plates, the rate of increase in yield strength increases, and the resistance to seismic forces weakens. In the invention, since the corrugated plate is used as the vibration control means, such inconvenience does not occur.

    According to the invention relating to the second means, the column head 6 and the column base 8 are formed by the vertical flat plate 10 having the swingable elasticity, so that cracking may occur due to an earthquake like a concrete connection structure. It is easy to repair after the earthquake.

    According to the third aspect of the invention, since the first and second flanges 12 and 18 are attached to the vertical flat plate 10 and the corrugated plate 16, respectively, the connecting operation is easy.

  1 to 4 show a vibration control pillar according to the present invention. The seismic control column 2 includes a pair of upper and lower base plates 4, 4, a column head 6, a column base 8, and a vibration absorbing damper 14.

  The base plate 4 is for fixing to the lower surface of the upper beam and the upper surface of the lower beam. The fixing method is bolted in the illustrated example, but any method may be used as long as sufficient strength is obtained.

  The column head 6 is suspended from the upper base plate 4, and the column base 8 is erected from the lower base plate 4. These column heads 6 and column bases 8 can have the same structure. Therefore, the structure common to the column head and column base will be described together. Each of the column heads 6 to the column bases 8 has a vertical plate 10 made of steel, and a pair of steel first flanges 12 are connected to each side end of the vertical plate in an H shape when viewed from above and below (preferably Is welded). In the illustrated example, the vertical flat plate 10 of the column head 6 or the column base 8 extends from the end of each first flange 12 to the inside of the beam middle portion to form an overlapping portion 10a with a corrugated plate described later. The vertical flat plate 10 is elastic enough to swing in the plate thickness direction with a connecting portion with the base plate as a fulcrum. The vertical flat plate 10 can be formed of high yield point steel (or high strength steel).

The upper end of the column head 6 is firmly attached to the upper base plate 4 and the lower end of the column base 8 is firmly attached to the lower base plate 4 so as to sufficiently resist the horizontal force in the in-plane direction F _{1 and the} outward direction F ₂ of the vertical flat plate. Connect (preferably weld).

  The vibration absorbing damper 14 has a corrugated plate 16 and a second flange 16 made of steel, respectively.

    The corrugated plate 16 has a corrugated structure as shown in FIG. 3, and upper and lower end portions thereof are overlapped with the overlapping portion 10 a of the column head 6 and the column base 8 and are bolted. As a result, it does not resist vertical deformation (and out-of-plane deformation) as shown in FIG. 5 (a), but resists in-plane deformation as shown in FIGS. Is formed. The corrugated plate 16 can be formed of low yield point steel.

    The second flange 18 is connected (preferably welded) to both side ends of the corrugated plate 16 such that the upper and lower end surface shapes are H-shaped. The second flange 16 is connected to the first flange 12 using a bolt and a joint plate.

  1, the corrugated plate resists seismic force while deforming from a rectangular shape to a parallelogram shape when viewed from the front when it vibrates in the horizontal direction (horizontal direction perpendicular to the plate thickness) in FIG. At this time, a hysteresis curve (not shown) representing the relationship between the deformation angle and the horizontal load draws a shape close to a spindle shape. This is because the corrugated plate 16 yields quickly by protruding the column head 6 and the column base 8 from the base plate. This allows more energy to be absorbed with the same seismic intensity.

    FIG. 6 shows an example in which four pillars in FIG. 1 are combined in a square shape when viewed from the top.

Next, with reference to FIGS. 7 to 9, a performance test performed on the test body of the stud according to the present invention will be described. Prior to the frame experiment, a member experiment using only corrugated steel damper elements was performed, and it was confirmed that there was sufficient performance as a hysteretic damper.
(1) Outline of Experiment As test bodies, the test body (D240) of the stud according to the present invention, the test body (D80) of Comparative Example 1 shown in FIG. 7, and the test body (D532) of Comparative Example 3 shown in FIG. ) Was used. The test body D240 of the present invention is a combination of upper and lower flat steel plates and corrugated steel dampers as shown in FIG. The test body D80 is a combination of upper and lower flat steel plates (plate thickness 12 mm) and flat steel plate dampers. The test body D532 uses a corrugated steel sheet as a damper instead of the three steel sheets of the present invention. The number after D is the vertical width (mm) of the damper portion. The height of each test specimen was 550 mm, and the width was 400 mm so as not to disturb the recoverability when combined with the PC frame. Regarding structures other than those described in the text of the specification, the description of the comparative test body is basically the same as the test body of the present invention, and the description thereof is omitted. Just to mention in.

The reason why the height (vertical width) of the damper was changed as an experimental variable is to make the overall deformation angle (shear deformation angle of the entire specimen) different when the damper yields. In the test, the lower end portion of each test specimen was fixed and repeated incremental loading was performed using a loading device that applies a horizontal load to the upper end portion.
(2) Experimental results Horizontal load-overall deformation angle of the damper (relative horizontal displacement above and below the specimen divided by the specimen height) relationship is shown in Fig. 9, and the horizontal load and overall deformation angle at yield and maximum proof stress are shown in Fig. 9. It shows in Table 2. The yield deformation angle exceeded the prediction for all specimens, and the experimental result was approximately 1.5 to 2 times the predicted value. The cause is considered to be that the deformation of the damper became smaller than expected due to slippage at the bolt joint between the damper and the steel body, and the occurrence of yield was delayed. In addition, since the height of the damper portion of the test body D80 was small, an oblique tension field was formed at an early stage, and the rigidity after yielding did not decrease like the other two bodies. In all the specimens, the yield strength once peaked due to the overall buckling of the damper portion, and in the case of further pushover, the yield strength increased until the damper portion broke.

  From the above results, it was found that by providing rigid body portions above and below the corrugated steel sheet, Ry (the member angle of the stud during the shear yielding of the damper) can be reduced and energy consumption can be started at an early stage. However, if the height of the damper portion is too small like the test body D80, the rigidity after yielding is increased, so that the shape (corrugated steel plate + flat steel plate) of the test body D240 of the present invention is suitable for use as a damper. It can be said that.

It is a front view of the seismic control stud concerning the embodiment of the present invention. It is a top view of the seismic control pillar of FIG. It is a longitudinal cross-sectional view of the seismic control pillar of FIG. It is a figure which shows the example of application to the beam of this invention. It is action explanatory drawing of the corrugated board of this invention. It is explanatory drawing of the Example of this invention. It is one test body for performing a comparison experiment with the present invention stud. It is another test body for performing contrast experiment with the stud of the present invention. It is a figure showing the test result of a test.

Explanation of symbols

2 ... Damping column 4 ... Base plate 6 ... Column head 8 ... Column base 10 ... Vertical flat plate 10a ... Overlap portion 12 ... First flange 14 ... Vibration absorbing damper 16 ... Corrugated plate 18 ... Second flange 104A, 104B ... Base plate 112A, 112B ... first flange 114A, 114B ... vibration absorbing damper 118A ... second flange

Claims (3)

A pair of upper and lower base plates;
A pair of column heads and column bases projecting in a direction facing each other from each base plate;
A vibration absorbing damper in which the opposite ends are connected to the tops of these column heads and column bases, and
In the seismic control pillar consisting of
The column heads 6 and the column bases 8 are at least steel vertical flat plates 10 parallel to each other,
Further, the seismic absorption damper 14 is formed of a corrugated plate 16 made of steel in which each ridge line of each wave is oriented in a horizontal direction parallel to the vertical flat plate 10.   The seismic control pillar according to claim 1, wherein the vertical flat plate (10) has an elasticity that can be swayed and deformed in the thickness direction by seismic motion.     A first flange 12 is attached to both ends of the vertical plate 10 of the column head 6 and the column base 8 in the horizontal direction, and second flanges 18 are attached to both sides of the corrugated plate 16 of the vibration absorbing damper 14 in the horizontal direction. The seismic control pillar according to claim 1 or 2, wherein the first and second flanges (12, 18) are joined to each other.

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