JP5415093B2 - Vibration control structure - Google Patents

Description

  The present invention relates to a vibration damping structure in which the vibration damping effect at the time of a medium-scale earthquake does not depend on the upper structure formed above the foundation beam.

  When a horizontal force such as an earthquake is applied to a building that has seismic elements such as braces, bearing walls, and load-bearing panels, the force that pushes down the lower horizontal member of the load-bearing panel is applied to the direction of the horizontal force at the bottom of the seismic element. A force acts to lift the lower horizontal member on the side opposite to the direction in which the horizontal force acts. In the case of a load-bearing panel installed on the first floor, this force is transmitted to the foundation, so the foundation must have strength and rigidity that can withstand this force.

  The so-called steel foundation (steel), which is composed of a combination of steel foundation beams and footings, solid foundations (pressure panels), piles, etc., as the foundation beams for low-rise, lightweight wooden and steel buildings such as detached houses There is a foundation called (foundation). Steel foundation can shorten construction period compared with general foundation constructed integrally with reinforced concrete, easy to recycle and reuse foundation beams, and reduce the amount of waste at the time of dismantling It is excellent in the point. However, since the rigidity is lower than that of a general foundation, there is a problem that it follows the rigid deformation of the seismic element when a horizontal force is applied, and it is difficult to exhibit the inherent performance of the seismic element. Further, when the steel foundation beam is separated from the ground in order to prevent corrosion, it is difficult to secure the blame of the foundation beam, and it becomes more difficult to ensure rigidity.

  In Patent Literature 1, in a frame having a multi-layer brace, when a horizontal force is applied by fitting a pillar cut off from a pile or a convex part at the lower end of the foundation beam and a concave part at the upper end of the pile, There is a description of a vibration control (synonymous with “vibration control”) structure in which an energy absorbing device such as a viscoelastic body is provided between the vertical surface of the convex portion and the vertical surface of the concave portion. According to this technique, when the horizontal force is applied and one of the pillars is lifted, the energy absorbing device exhibits a damping performance, and the amount of lifting is controlled, so that a damping effect is expected.

JP 2002-276192 A

  However, in the technique described in Patent Document 1, the attenuation performance of the energy absorbing device is exhibited only when the column is lifted. However, when the column is pushed downward, the horizontal surface of the convex portion and the horizontal surface of the concave portion remain in contact with each other, and the attenuation performance of the energy absorbing device is not exhibited.

  The object of the present invention is to provide a vibration damping structure that is highly safe against horizontal forces such as earthquakes, and in particular, does not depend on the superstructure for the damping effect during a medium-scale earthquake without impairing the merit of the steel foundation. There is.

  In order to solve the above-described problems, a vibration damping structure according to the present invention includes a foundation beam supported by a bundle installed on a building load support portion, and a vertical gap between the foundation beam and the first layer beam. A load-bearing panel comprising a pair of provided columns, a connecting portion that connects the pair of columns, and a lower part of one or both of the pair of columns constituting the load-bearing panel, and the building load support portion. And a damping member that is interposed at a position between the base beam and attenuates the vertical displacement of the base beam. Here, the building load support portion is a portion that supports the load of the upper structure of the building such as a footing, a solid foundation (pressure board), and a pile and transmits it to the ground.

  In the above vibration damping structure, the foundation beam is configured so that the deformation always remains in the elastic region by the vibration damping member, and the connecting portion constituting the load-bearing panel is elastically plastically deformed to absorb energy. In the event of an earthquake of a predetermined size or less, the energy absorption is performed by the damping member, and in the event of an earthquake exceeding a predetermined size, energy is absorbed by the damping member and the energy absorbing portion of the load-bearing panel that is plastically deformed. It is characterized by absorption.

  In the vibration damping structure according to the present invention, the vibration damping member that attenuates the vertical displacement of the foundation beam is between the building load support portion and the foundation beam, and the portion in which the vertical displacement of the foundation beam increases during an earthquake. Because it is placed under the pillars that make up the load-bearing panel, energy can be absorbed effectively, and the damping effect is maximized.

  In addition, since the damping member is placed under the pillar that constitutes the load-bearing panel, part of the downward vertical force acting on the pillar is borne by the damping member, reducing the vertical load borne by the building load support section. can do.

  In addition, in the case of a middle earthquake (earthquake where the interlayer deformation angle is allowed to 1/200 in the load-bearing panel), the damping effect is generated by the damping member under the foundation beam. This increases the degree of freedom in designing the load-bearing panel.

It is a figure which illustrates the vibration control structure concerning the present invention typically. It is a figure explaining the structure of a damping member, and explaining the relative position with a load-bearing panel. It is a figure explaining the behavior at the time of an earthquake. It is a figure explaining the behavior of the damping member at the time of an earthquake. It is a figure explaining the structure of the other example of a damping member.

  The vibration damping structure according to the present invention can simplify the design of the load-bearing panel of the superstructure by rationalizing the foundation construction method and realizing a vibration damping structure that does not depend on the superstructure for the damping effect during a medium-scale earthquake. It is what I did.

  In the vibration damping structure shown in FIG. 1, a foundation beam 3 is supported by a bundle 2 disposed on the upper part of a building load support portion (solid foundation) 1, and between the foundation beam 3 and the first layer beam 4. A load bearing panel A constituted by a pair of pillars 10a and 10b and a connecting portion 11 connecting the pair of pillars 10a and 10b is arranged, below the pillar 10b constituting the load bearing panel A, and on the foundation beam 3 and a solid foundation. A damping member B is disposed between the first and second members.

  In the present invention, the structure and the number of layers of the building are not limited, and the present invention can be applied to a two-story or three-story building having a wooden frame or a steel frame. In this embodiment, the present invention is applied to a two-layered steel-frame industrial house having a frame in which a load-bearing panel A is arranged in each layer of the beam-winning method.

  The building load support unit 1 is a structure that can support the load of the building and transmit the load to the ground, and can selectively employ footing, a solid foundation (pressure board) pile, or the like. In this embodiment, a solid foundation 1 made of reinforced concrete is employed as the building load support portion 1.

  The foundation beam 3 is supported by the bundle 2 so as to be spaced apart from the solid foundation 1. The position at which the foundation beam 3 is supported by the bundle 2 and the position at which the foundation beam 3 is supported is not limited, and it is sufficient that the foundation beam 3 is stably supported at least without the vibration damping member B being installed.

  As the foundation beam 3, a steel beam, a wooden beam, or the like can be selectively employed in accordance with the building structure of the building. In this embodiment, the foundation beam 3 is constituted by a steel beam made of H-shaped steel. Further, the foundation beam 3 is made of the same specification H-shaped steel having the same beam length as the first layer beam 4. For this reason, it is possible to rationalize manufacturing and management without increasing the number of beam types.

  A load bearing panel A serving as a load bearing element is disposed at a predetermined position on the plane between the foundation beam 3 and the first layer beam 4. The load-bearing panel A has a function of elastically acting during a medium earthquake and plasticizing and absorbing energy during a large earthquake, and an existing load-bearing panel can be used as it is.

  In this embodiment, the load-bearing panel A is arranged with a predetermined interval, and a pair of columns 10a and 10b whose upper and lower ends are pin-connected to the foundation beam 3 and the first layer beam 4 by bolts, respectively, It arrange | positions at the inner side of a pair of pillar 10a, 10b, and is comprised by the connection part 11 which connects these pillar 10a, 10b.

  The arrangement position of the load-bearing panel A between the foundation beam 3 and the first layer beam 4 is not limited, and should be set as appropriate when designing the frame. In the present embodiment, the load-bearing panel A is disposed at the corner of the building, the damping member B is disposed below the one column 10a, and the bundle 2 is disposed below the other column 10b. A second-layer pillar 5 is disposed above. Therefore, the other pillar 10b has the same function as the pillar of the general part.

  The connecting portion 11 has an energy absorbing function, and two sets are attached in the vertical direction between the pair of pillars 10a and 10b.

  The connection part 11 consists of a pair of frame material 12 attached along a pair of pillar 10a, 10b, and the energy absorption material 13 which connects a pair of frame material 12. The frame member 12 has a vertical frame 12a, a horizontal frame 12b whose one end is bonded to the center position in the height direction of the vertical frame 12a and perpendicular to the vertical frame 12a, and one end bonded to the upper and lower ends of the vertical frame 12a. And the other end of the horizontal frame 12b is joined to the other end of the horizontal frame 12b through a connecting plate, and the frame member 12 forms an isosceles triangle as a whole, and has high rigidity. have. Bolt holes are drilled in the connecting plate, and the horizontal frame 12b and the oblique frame 12c constituting the frame member 12 are joined using the bolt holes, and the connecting plates are connected by the energy absorbing material 13. ing.

  The energy absorbing member 13 is made of a plate-like ultra-low yield point steel plate with a butterfly shape when viewed from the front, and the constricted portion yields by an external force exceeding a predetermined value, and is configured to absorb the energy of seismic force by plastic deformation. Has been. Bolt holes are drilled at both ends of the energy absorbing member 13, and the bolts are used to join the connecting plate of the frame member 12 with the bolts. One or more energy absorbing members 13 can be connected depending on the amount of energy absorption required.

  The energy absorbing member 13 may be made of ordinary steel or low yield point steel that can be plastically deformed and absorb energy by a predetermined external force.

  The structure of the bundle 2 is not particularly limited, and is preferably set as appropriate according to the structure and material of the foundation beam 3. In this embodiment, a steel bundle 2 is employed. Moreover, the pillar 5 of the 2nd layer employ | adopts the steel pillar of the same structure as the pillars 10a and 10b which comprise the load-bearing panel A. FIG.

  The damping member B is a lower part of one or both of the pair of columns 10a and 10b constituting the load-bearing panel A arranged between the foundation beam 3 and the first layer beam 4, and the foundation beam 3 and the solid foundation 1 and has a function of attenuating the displacement in the vertical direction of the foundation beam 3 generated according to the force acting on the columns 10a and 10b during an earthquake.

  As the damping member B, any member can be employed as long as it can absorb energy and exhibit the above-described damping function in the event of an earthquake. What has such a function includes a viscoelastic damper using a viscoelastic body such as a high damping rubber, a viscous body such as oil, in addition to a member using plastic deformation of a steel material like a vibration damping member B described later. There are viscous dampers using friction and friction dampers using friction. Of these, it is preferable to adopt a suitable structure by examining conditions such as the frame structure of the target building and the amount of displacement in the vertical direction that would occur in the foundation beam 3.

  In this embodiment, the damping member B is disposed below the column 10a constituting the load-bearing panel A, and a vertical force (axial force) acts on the column 10a during an earthquake, and is generated according to this axial force. It is comprised so that the displacement of the up-down direction of the foundation beam 3 can be attenuated.

  As shown in FIG. 2, the damping member B includes a displacement portion 23 fixed to the foundation beam 3 in the center in plan view, and a plurality of leg portions 26 arranged to surround the displacement portion 23 and fixed to the solid foundation 1. And a deformation portion 24 that connects the displacement portion 23 and the leg portion 26. The displacement portion 23 is a portion that displaces following the displacement in the vertical direction of the foundation beam 3, and a space 25 is formed below it based on the assumed maximum displacement. The deformation part 24 is designed to be plastically deformed in the event of an earthquake larger than a middle earthquake in accordance with the displacement of the displacement part 21, and is a part that absorbs energy.

  In the present embodiment, four crank-shaped steel plates are prepared, and these are joined by welding or the like in a cross shape in plan view to form the displacement portion 23, the leg portion 26, and the deformation portion 24. Further, the deformable portion 24 is formed in a ladder shape by a plurality of slit holes 24a, and is configured to easily cause shear deformation.

  Further, a lower plate 21 having a rectangular shape and a plurality of bolt holes 21a for fixing the bolt to the solid base 1 at each corner is attached to the lower end of the leg 26 by welding or the like. At the upper end of the portion 23, a rectangular shape having a smaller size than the lower plate 21 is formed, and a plurality of bolt holes 22a for bolting to the lower flange 3a of the foundation beam 3 are formed at each corner. The upper plate 22 is attached by welding or the like. Therefore, the damping member B can be easily replaced when the initial performance is not exhibited due to repeated deformation.

  When the building adopting the vibration control structure configured as described above receives a middle earthquake, as shown in FIGS. 3A and 4, the downward force from the column 10 a corresponding to the horizontal force is applied to the foundation beam 3. Accordingly, a downward displacement is generated in the foundation beam 3, and the displacement portion 23 of the damping member B is displaced downward in accordance with the displacement of the foundation beam 3. Along with the displacement of the displacement portion 23, shear deformation that reaches the plastic region occurs in the deformation portion 24, and energy is absorbed by this shear deformation, and the displacement of the foundation beam 3 is attenuated.

  Further, when a horizontal force in the reverse direction (left direction in the figure) is applied, the displacement portion 23 of the damping member B is displaced upward by the same mechanism. Along with the displacement of the displacement portion 23, shear deformation that reaches the plastic region in the opposite direction occurs in the deformation portion 24, and energy is absorbed by this shear deformation, and the downward displacement of the foundation beam 3 is attenuated.

  On the other hand, in the load-bearing panel A, the frame material 12 falls while maintaining the shape of an isosceles triangle according to the interlayer deformation, and the deformation of the connecting portion 11 is concentrated in the energy absorbing material 13. The deformation of the material 13 remains in the elastic region and does not cause plastic deformation.

  When the building is subjected to a large earthquake, the behavior of the damping member B is the same as when a moderate earthquake is received. On the other hand, as shown in FIG. 3B, the horizontal force acting on the load-bearing panel A increases, and the interlayer deformation also increases with the load-bearing panel A. And the energy absorption material 13 which connects a pair of frame material 12 which comprises the connection part 11 produces a plastic deformation. Thus, in addition to the energy absorption of the damping member B, the energy absorber 13 is plastically deformed, so that a larger energy can be absorbed in the event of a large earthquake.

  According to the above configuration, the damping member B that attenuates the displacement in the vertical direction of the foundation beam 3 is between the solid foundation 1 and the foundation beam 3 that are the building load support portions, and the vertical direction of the foundation beam 3 during an earthquake. Since it is interposed under the pillar 10a that constitutes the load bearing panel A, which is a portion where the displacement increases, energy can be absorbed effectively, and the vibration damping effect is maximized.

  Furthermore, since the damping member B is arranged under the pillar 10a constituting the load-bearing panel A, a part of the downward vertical force acting on the pillar 10a is borne by the damping member B, and the solid load is a building load support portion. The vertical load borne by the foundation 1 can be reduced.

  Further, in the case of a middle earthquake, the damping effect is generated by the damping member B under the foundation beam 3, so that it is not necessary to suppress the vibration with the load-bearing panel A during the middle earthquake. That is, it is extremely difficult to design the load-bearing panel A so that the energy absorbing material 13 is appropriately plasticized and controlled in a middle earthquake, but it is not necessary to design such a design, and the design is limited to elastic deformation that is easy to design. Can be done. Therefore, the design freedom of the load-bearing panel A is improved.

  Further, since the displacement of the foundation beam 3 is suppressed by the damping member B, it is possible to design economically by setting the rigidity and proof stress small. In addition, by designing the foundation beam 3 so as not to be plastically deformed even at the maximum displacement assumed at the time of a large earthquake, the energy absorbing material 13 of the load-bearing panel A or the control can be obtained even in the event of a large earthquake. The performance can be recovered only by exchanging the vibration member B, and there is no need to perform a large-scale restoration work involving the replacement of the foundation beam 3.

  Next, another structure of the damping member B will be described with reference to FIG. The vibration damping member B shown in the figure is configured to attenuate the displacement of the foundation beam 3 with an attenuation member such as a high attenuation rubber.

  The damping member B includes a cylinder 31 whose lower end is fixed to the solid foundation 1 and whose upper end is opened, and a rod whose upper end is fixed to the lower flange 3a of the foundation beam 3 and whose lower end is inserted into the cylinder 31. 32 and a damping member 33 that is bonded to and interposed on the outer surface of the inner rod 32 of the cylinder 31.

  In the damping member B configured as described above, when the base beam 3 is displaced in the vertical direction due to the axial force acting on the column 10a constituting the load-bearing panel A during an earthquake, the rod 32 is moved along with this displacement. It moves up and down, and the damping member 33 is deformed during this movement. This deformation can absorb energy and attenuate the displacement of the foundation beam 3.

  The vibration damping structure of the present invention is advantageous when used for the foundation of a building having a steel frame or a wooden frame that has low rigidity other than reinforced concrete and can be easily recycled and reused.

A Load-bearing panel B Damping member 1 Solid foundation (building load support)
2 Bundles 3 Foundation Beam 3a Lower Flange 4 First Layer Beam 5 Column 10a, 10b Column 11 Connection 12 Frame Material 12a Vertical Frame 12b Horizontal Frame 12c Diagonal Frame 13 Energy Absorbing Material 21 Lower Plate 21a Bolt Hole 22 Upper Plate 22a Bolt Hole 23 Displacement part 24 Deformation part 24a Slit hole 25 Space 26 Leg part 31 Cylinder 32 Rod 33 Damping member

Claims (2)

A foundation beam supported by a bundle installed on the building load support;
A load-bearing panel comprising a pair of columns erected at a predetermined interval between the foundation beam and the first layer beam, and a connecting portion that connects the pair of columns;
It is interposed under both or one of the pair of pillars constituting the load-bearing panel and at a position between the building load support portion and the foundation beam, and suppresses the vertical displacement of the foundation beam. A vibration damping structure comprising: a vibration member. The foundation beam is configured so that the deformation always remains in the elastic region by the damping member,
The connecting portion constituting the load-bearing panel includes an energy absorbing portion that absorbs energy by elastic-plastic deformation,
During an earthquake of a predetermined magnitude or less, energy is absorbed by the vibration damping member,
2. The vibration damping structure according to claim 1, wherein energy is absorbed by the vibration damping member and an energy absorbing portion of the load-bearing panel that is plastically deformed in the event of an earthquake exceeding a predetermined magnitude.

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