Seismic isolation structure

Abstract

To provide a seismic isolation structure with a reduced area occupied by an attenuation device and a stopper member compared to when the attenuation device and the stopper member are arranged at different positions.SOLUTION: A seismic isolation structure comprises: a lower structure body; an upper structure body supported by the lower structure body via a seismic isolation device; a stopper member provided at one of the upper structure body and the lower structure body and projecting downwardly or upwardly; a load receiving part provided at the other of the upper structure body and the lower structure body and facing the stopper member; and an attenuation device having one end fitted to the stopper member and the other end fitted to the other of the upper structure body and the lower structure body, and attenuating a vibration by a telescopic movement.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a seismic isolation structure.

Background Art

[0002] Patent Document 1 describes a seismic isolation structure with a fail-safe mechanism that restricts the relative displacement between a lower structure and an upper structure from becoming larger when an assumed maximum-level great earthquake occurs and the relative displacement between the lower structure and the upper structure exceeds the assumption.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The fail-safe mechanism provided in the conventional seismic isolation structure includes a vertically extending displacement restricting main body portion (load receiving portion) provided in the lower structure of the seismic isolation building and a contact portion (stopper member) that collides with the displacement restricting main body portion provided in the upper structure. And the fail-safe mechanism restricts the relative displacement between the lower structure and the upper structure.

[0005] In such a seismic isolation structure, when an earthquake occurs, the damping device that attenuates the vibration of the upper structure is arranged at a different position from the stopper member.

[0006] The problem of the present disclosure is to reduce the area occupied by the damping device and the stopper member as compared with the case where the damping device and the stopper member are arranged at different positions.

Means for Solving the Problems

[0007] The seismic isolation structure according to the first embodiment is characterized by comprising: a lower structure; an upper structure supported by the lower structure via a seismic isolation device; a stopper member provided on one of the upper structure and the lower structure and projecting downward or upward; a load receiving portion provided on the other of the upper structure and the lower structure and facing the stopper member; and a damping device having one end attached to the stopper member and the other end attached to a support portion provided on the other of the upper structure and the lower structure, which dampens vibrations by expanding and contracting.

[0008] In the seismic isolation structure according to the first embodiment, when an earthquake occurs, the seismic isolation device causes the superstructure and the substructure to move relative to each other, thereby suppressing the transmission of earthquake tremors from the substructure to the superstructure.

[0009] In this scenario, when the superstructure and the substructure move relative to each other, the damping device expands and contracts to dampen the vibrations of the superstructure.

[0010] Furthermore, if the upper and lower structures move relative to each other more than expected, the stopper member will collide with the load-bearing part, restricting the relative movement between the upper and lower structures. This prevents damage to the seismic isolation device.

[0011] Here, one end of the damping device is attached to the stopper member. Therefore, the area occupied by the damping device and the stopper member can be reduced compared to the case where the damping device and the stopper member are located in different positions.

[0012] The seismic isolation structure according to the second embodiment is characterized in that, in the seismic isolation structure according to the first embodiment, a cushioning material that collides with the load receiving portion is attached to the portion of the stopper member that faces the load receiving portion, and an energy absorbing portion with lower strength compared to other portions is formed between the portion of the stopper member to which the cushioning material is provided and the portion of the stopper member to which one end of the damping device is attached.

[0013] In the seismic isolation structure according to the second embodiment, an energy absorbing section with lower strength compared to other parts is formed between the part of the stopper member to which a cushioning material is provided and the part of the stopper member to which one end of the damping device is attached.

[0014] This prevents damage to the damping device by causing deformation of the energy absorption section when the upper and lower structures move relative to each other more than expected and the stopper member collides with the load-receiving section.

[0015] The seismic isolation structure according to the third embodiment is characterized in that, in the seismic isolation structure according to the second embodiment, it has a base provided on the lower structure to which the seismic isolation device is attached, the stopper member is fixed to the beam of the upper structure, and the load receiving portion is fixed to the base and faces the stopper member.

[0016] In the seismic isolation structure according to the third embodiment, the load-bearing portion is fixed to a base to which the seismic isolation device is attached. Therefore, when the stopper member collides with the load-bearing portion, the load-bearing portion and the base exert a resisting force. For this reason, the load-bearing portion can be made thinner compared to the case where only the load-bearing portion exerts a resisting force. [Effects of the Invention]

[0017] According to this disclosure, the area occupied by the damping device and the stopper member can be reduced compared to the case where the damping device and the stopper member are located in different positions. [Brief explanation of the drawing]

[0018] [Figure 1] This is a side view showing a seismic isolation structure according to an embodiment of the present disclosure. [Figure 2] This is a plan view showing a building equipped with a seismic isolation structure according to the present disclosure. [Figure 3] This is a plan view showing a seismic isolation structure according to an embodiment of the present disclosure. [Figure 4](A)(B) Cross-sectional view showing the stopper member provided in the seismic isolation structure according to an embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0019] An example of the seismic isolation structure according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 4. In the figures, the arrow H indicates the vertical direction, which is the up-and-down direction of the structure (hereinafter simply referred to as the "up-and-down direction"), the arrow W indicates the horizontal direction, which is the width direction of the structure (hereinafter simply referred to as the "width direction"), and the arrow D indicates the horizontal direction, which is the depth direction of the structure (hereinafter simply referred to as the "depth direction"). The arrow W and the arrow D are perpendicular to each other.

[0020] As shown in FIG. 1, the seismic isolation structure 10 according to an embodiment of the present disclosure is used in a building 100, and includes a lower structure 12, a seismic isolation device 14 attached to the lower structure 12, and an upper structure 16 supported by the seismic isolation device 14. Further, the seismic isolation structure 10 includes a fail-safe mechanism 22 for suppressing breakage of the seismic isolation device 14 and a damping device 70 for damping vibration of the upper structure 16. Although details of this fail-safe mechanism 22 will be described later, the fail-safe mechanism 22 includes a stopper member 30 and load receiving portions 40 and 42 that receive loads from the stopper member 30.

[0021] (Lower structure 12, seismic isolation device 14, upper structure 16) 〔Lower structure 12〕 As shown in FIG. 1, the lower structure 12 is the foundation of the building 100, and includes a plurality of foundation beams 12a extending in the width direction or the depth direction, and a plurality of pedestals 12b provided at intersections of the plurality of foundation beams 12a. Further, the lower structure 12 includes a protruding portion 12c that protrudes upward from the foundation beam 12a and to which an end portion of the damping device 70 is attached. The protruding portion 12c is an example of a support portion.

[0022] 〔Seismic isolation device 14〕 As shown in Figure 1, the seismic isolation device 14 is supported on a base 12b and consists of a pair of upper and lower flanges 14a and laminated rubber 14b provided between the pair of flanges 14a. The lower flange 14a of the seismic isolation device 14 is attached to the base 12b by bolts.

[0023] [Superstructure 16] As shown in Figure 1, the superstructure 16 is a steel-framed column-beam structure, composed of columns 16a joined to beam members 16b. The lower end of the column 16a protrudes below the lower end surface of the beam member 16b, which is located at the very bottom. A base plate 16c is attached to the lower end of the column 16a, and the upper flange 14a of the seismic isolation device 14 is attached to this base plate 16c by bolts.

[0024] (Fail-safe mechanism 22) As shown in Figure 2, the fail-safe mechanism 22 can be divided into two types: one equipped with multiple stopper members 30 fixed to beam members 16b extending in the width direction, and another equipped with a stopper member 30 fixed to beam members 16b extending in the depth direction.

[0025] The fail-safe mechanism 22 equipped with a stopper member 30 fixed to a beam member 16b extending in the width direction and the fail-safe mechanism 22 equipped with a stopper member 30 fixed to a beam member 16b extending in the depth direction have the same configuration. The fail-safe mechanism 22 equipped with a stopper member 30 fixed to a beam member 16b extending in the width direction will be described below.

[0026] The fail-safe mechanism 22 is a mechanism that restricts the relative displacement between the lower structure 12 and the upper structure 16 to suppress the fracture of the seismic isolation device 14. As shown in Figure 1, this fail-safe mechanism 22 includes a stopper member 30, load receiving parts 40 and 42, and a cushioning material 50.

[0027] [Stopper member 30] As shown in Figure 1, the stopper member 30 is positioned between a pair of bases 12b that are aligned in the width direction, and is close to one side in the width direction (the left side in the figure). The stopper member 30 is fixed to a beam member 16b that extends in the width direction, and protrudes downward from the beam member 16b, extending in the vertical direction.

[0028] The stopper member 30, which extends in the vertical direction, comprises a lower end portion 30a to which the cushioning material 50 is attached, a mounting portion 30b to which one end of the damping device 70 is attached, and an intermediate portion 30c positioned between the lower end portion 30a and the mounting portion 30b in the vertical direction. The intermediate portion 30c is an example of an energy absorption portion.

[0029] -Lower end 30a- As shown in Figure 3, the lower end portion 30a of the stopper member 30 is equipped with a support plate 32 that is X-shaped when viewed from above. Furthermore, the lower end portion 30a is equipped with plates 34a, 34b, and 34c that are arranged along the edges of a roughly octagonal shape around the support plate 32 and are supported by the support plate 32.

[0030] A pair of plates 34a are provided and are rectangular in shape when viewed from the thickness direction. The surface of the plates 34a is oriented in the width direction in which the beam member 16b extends. The pair of plates 34a are positioned on one side and the other side in the width direction relative to the support plate 32.

[0031] A pair of plates 34b are provided and are rectangular in shape when viewed from the thickness direction. The surface of plate 34b is oriented in the depth direction, which is perpendicular to the width direction in which the beam member 16b extends. The horizontal length of plate 34b is shorter than the horizontal length of plate 34a. The pair of plates 34b are positioned on the front and rear sides in the depth direction relative to the support plate 32.

[0032] Four plates 34c are provided, and they are rectangular in shape when viewed from the thickness direction. The surfaces of two plates 34c are oriented in a direction that is inclined to one side with respect to the width direction in which the beam member 16b extends, while the surfaces of the other two plates 34c are oriented in a direction that is inclined to the other side with respect to the width direction in which the beam member 16b extends. Furthermore, the horizontal length of these plates 34c is the same as the horizontal length of plate 34a.

[0033] When viewed from above, plate 34c extends from the end of plate 34a to the end of plate 34b, with one end of plate 34c connected to the end of plate 34a and the other end of plate 34c connected to the end of plate 34b.

[0034] -Mounting part 30b- As shown in Figure 4(A), the mounting portion 30b of the stopper member 30 is rectangular in shape when viewed from above and is formed using a steel pipe. As shown in Figure 1, one end of the damping device 70 is attached to the surface of the mounting portion 30b facing the other side in the width direction.

[0035] -Middle part 30c- As shown in Figure 4(B), the intermediate portion 30c of the stopper member 30 is shaped like a cross H when viewed from above, and is formed using a cross H-shaped steel beam. The thickness of each plate material forming the intermediate portion 30c is thinner than the thickness of the steel pipe material forming the mounting portion 30b and the thickness of each plate material forming the lower end portion 30a.

[0036] In this configuration, the bending rigidity of the intermediate section 30c is lower than that of the mounting section 30b and the lower end section 30a. In other words, the strength of the intermediate section 30c is lower than that of the mounting section 30b and the lower end section 30a.

[0037] [Buffer material 50] The cushioning material 50 is formed using an elastic material such as rubber and is attached to the surfaces of plates 34a and 34c, as shown in Figure 3. In other words, the cushioning material 50 is attached to the outer circumferential surface of the lower end portion 30a of the stopper member 30.

[0038] [Load-bearing sections 40, 42] The load-bearing sections 40 and 42 are provided on the lower structure 12, as shown in Figure 1.

[0039] The load-bearing portion 40 is a concrete member fixed to the base 12b, and the load-bearing portion 42 is a concrete member fixed to the foundation beam 12a.

[0040] -Load-bearing section 40- As shown in Figure 1, the load-receiving portion 40 is fixed to the base 12b on the side of the stopper member 30. Furthermore, as shown in Figure 3, the load-receiving portion 40 is positioned to partially surround the stopper member 30. Specifically, the load-receiving portion 40 has an opposing portion 40a that faces the plate 34a of the stopper member 30, and an opposing portion 40c that faces the plate 34c of the stopper member 30.

[0041] Comparing the thickness T1 of the opposing portion 40a with the thickness T2 of the opposing portion 40c, thickness T2 is greater. Here, "thickness" refers to the thickness in the direction opposite to plates 34a and 34c.

[0042] Furthermore, if the distance between the opposing part 40a and the plate 34a is denoted as distance L1, and the distance between the opposing part 40c and the plate 34c is denoted as distance L2, then distances L1 and L2 are considered to be the same. Note that these distances L1 and L2 are set to be less than or equal to the deformation dimension at which the laminated rubber 14b of the seismic isolation device 14 begins to undergo plastic deformation when it undergoes shear deformation during an earthquake.

[0043] Furthermore, the load-receiving section 40 is equipped with reinforcing bars B1, B2, and B3 (see Figure 1), the ends of which are inserted into the base 12b, in order to transmit the load acting from the stopper member 30 to the base 12b.

[0044] In this configuration, if the upper structure 16 and the lower structure 12 move relative to each other more than expected during an earthquake, the plates 34a and 34c of the stopper member 30 collide with the opposing parts 40a and 40c of the load-receiving part 40 via the buffer material 50, thereby restricting the relative movement between the upper structure 16 and the lower structure 12. This suppresses plastic deformation of the laminated rubber 14b of the seismic isolation device 14. In other words, the laminated rubber 14b of the seismic isolation device 14 deforms within the elastic range.

[0045] Furthermore, the cushioning material 50 reduces the impact when the stopper member 30 collides with the load-receiving parts 40 and 42. In addition, the cushioning material 50 absorbs collision energy by undergoing plastic deformation.

[0046] -Load-bearing section 42- As shown in Figure 1, the load-receiving portion 42 is positioned on the opposite side of the load-receiving portion 40 in the width direction, with the stopper member 30 in between, and is fixed to the foundation beam 12a.

[0047] As shown in Figure 3, the load-receiving portion 42 is positioned to partially surround the stopper member 30. Specifically, the load-receiving portion 42 has an opposing portion 42a that faces the plate 34a of the stopper member 30, and an opposing portion 42c that faces the plate 34c of the stopper member 30.

[0048] In this embodiment, of the two plates 34c of the stopper member 30, the opposing portion 42c is provided on the side facing one of the plates 34c (the upper plate in Figure 3), while the opposing portion 42c is not provided on the side facing the other plate 34c (the lower plate in Figure 3).

[0049] In this configuration, work space is secured for reinforcing the load-receiving sections 40 and 42, pouring concrete, and installing the buffer material 50, thereby improving constructability. As shown by the dashed line in Figure 3, an opposing section 42c may also be provided on the side facing the other plate 34c.

[0050] Furthermore, the thickness of the opposing portion 42c is equal to the thickness of the opposing portion 40c, and is set to a thickness T2. In addition, it is preferable that the thickness T3 of the opposing portion 42a be approximately the same as the thickness T2 of the opposing portion 42c, but in this embodiment, the thickness T3 is greater.

[0051] Furthermore, the distance between the opposing part 42a and the plate 34a is the same as the distance L1 described above, and the distance between the opposing part 42c and the plate 34c is the same as the distance L2 described above.

[0052] Furthermore, as shown in Figure 1, the ends of the reinforcing bars (for example, reinforcing bar B4) arranged in the load-receiving section 42 are inserted into the foundation beam 12a in order to transmit the external force acting from the stopper member 30 to the foundation beam 12a.

[0053] (Damping device 70) As shown in Figure 1, the damping device 70 is positioned in the width direction on the opposite side of the load-receiving portion 40 with the stopper member 30 in between, and in the vertical direction above the load-receiving portion 42. In this embodiment, the damping device 70 uses, as an example, a damping choke that exhibits damping performance by the viscous resistance force of a viscous material.

[0054] The damping device 70 extends in the width direction, and one end of the damping device 70 is attached to the mounting portion 30b of the stopper member 30. The other end of the damping device 70 is attached to a projection 12c that protrudes upward from the foundation beam 12a. The projection 12c is located in the width direction between a pair of adjacent bases 12b and on the opposite side of the stopper member 30, with the load receiving portion 42 in between.

[0055] In this configuration, when the superstructure 16 and the lower structure 12 move relative to each other during an earthquake, the damping device 70 expands and contracts. As a result, the damping device 70 dampens the vibrations of the superstructure 16.

[0056] (Function of the main components) In the seismic isolation structure 10 according to this embodiment, the seismic isolation device 14 shown in Figure 1 moves the upper structure 16 and the lower structure 12 relative to each other, thereby suppressing the transmission of earthquake tremors from the lower structure 12 to the upper structure 16. Furthermore, when the upper structure 16 and the lower structure 12 move relative to each other, a damping device 70, one end of which is attached to a stopper member 30, expands and contracts, thereby damping the vibration of the upper structure 16.

[0057] Furthermore, if the upper structure 16 and the lower structure 12 move relative to each other more than expected, the stopper member 30 will collide with the load-receiving parts 40 and 42 via the cushioning material 50.

[0058] Since the load-bearing portion 40 is fixed to the base 12b, both the load-bearing portion 40 and the base 12b exert resistance. Furthermore, since the load-bearing portion 42 protrudes from the foundation beam 12a, a bending moment M1 acts on the portion of the foundation beam 12a where the load-bearing portion 42 protrudes. The foundation beam 12a exerts resistance to this bending moment M1.

[0059] On the other hand, the stopper member 30 fixed to the beam member 16b of the superstructure 16 is subjected to reaction forces from the load-receiving parts 40 and 42. Then, as shown in Figure 1, a bending moment M2 acts on the portion of the beam member 16b to which the stopper member 30 is fixed. The beam member 16b exerts resistance against this bending moment M2.

[0060] Furthermore, when the stopper member 30 collides with the load-receiving parts 40 and 42 via the cushioning material 50, the intermediate part 30c of the stopper member 30 deforms, thereby suppressing the deformation of the mounting part 30b to which one end of the damping device 70 is attached.

[0061] (summary) As explained above, in the seismic isolation structure 10, one end of the damping device 70 is attached to the stopper member 30, and the other end of the damping device 70 is attached to a protruding portion 12c that extends from the foundation beam 12a of the substructure 12. This makes it possible to reduce the area occupied by the damping device 70 and the stopper member 30 compared to the case where the damping device and the stopper member are located in different positions.

[0062] Furthermore, in the seismic isolation structure 10, the stopper member 30 is provided with an intermediate section 30c having reduced bending rigidity between the lower end portion 30a, which collides with the load-receiving portions 40 and 42, and the mounting portion 30b, to which one end of the damping device 70 is attached. This allows the intermediate section 30c to deform and absorb earthquake energy when the upper structure 16 is displaced relative to the lower structure 12 more than expected.

[0063] Furthermore, in the seismic isolation structure 10, if the upper structure 16 experiences a relative displacement greater than expected with respect to the lower structure 12, the deformation of the intermediate section 30c suppresses deformation of the mounting section 30b. This prevents damage to the damping device 70, one end of which is attached to the mounting section 30b.

[0064] Furthermore, in the seismic isolation structure 10, the load-receiving portion 40 is fixed to the base 12b to which the seismic isolation device 14 is attached. Therefore, when the stopper member 30 collides with the load-receiving portion 40, both the load-receiving portion 40 and the base 12b exert resistance. As a result, the load-receiving portion can be made thinner compared to the case where only the load-receiving portion exerts resistance.

[0065] Furthermore, in the seismic isolation structure 10, the load-receiving parts 40 and 42 and the stopper member 30 face each other in the direction in which the beam member 16b extends (the width direction in Figure 1). Therefore, the axial strength and bending strength of the beam member 16b in the axial direction can be exerted as a resistance force received from the stopper member 30.

[0066] Furthermore, in the seismic isolation structure 10, a cushioning material 50 is attached to the lower end 30a of the stopper member 30. This reduces the impact force when the stopper member 30 collides with the load-receiving parts 40 and 42. In addition, the impact energy can be absorbed by, for example, plastically deforming the cushioning material 50.

[0067] Although this disclosure has been described in detail with respect to specific embodiments, it will be apparent to those skilled in the art that this disclosure is not limited to these embodiments, and that various other embodiments are possible within the scope of this disclosure. In the above embodiments, the stopper member 30 is provided on the upper structure 16 and the load-receiving portions 40 and 42 are provided on the lower structure 12, but the stopper member may be provided on the lower structure and the load-receiving portions may be provided on the upper structure.

[0068] Furthermore, in the above embodiment, the seismic isolation device 14 is attached to a base 12b provided at the intersection of the foundation beams 12a, but the seismic isolation device may also be attached to the top of the column. A so-called column-top seismic isolation structure may also be used.

[0069] Furthermore, although the cross-section of the intermediate portion 30c was cross-shaped in the above embodiment, the shape is not limited to this, and it is sufficient that the bending rigidity of the intermediate portion 30c is lower than that of the mounting portion 30b and the bending rigidity of the lower end portion 30a.

[0070] Furthermore, in the above embodiment, a damping element was used as the damping device 70, but for example, an oil damper or a metal damper may also be used.

[0071] Furthermore, although the superstructure 16 in the above embodiment was made of steel, it may also be made of reinforced concrete or the like.

[0072] Furthermore, although a cushioning material 50 was used in the above embodiment, it is not necessary to use a cushioning material. In this case, the effect achieved by using a cushioning material will not be achieved.

[0073] Furthermore, although an example was shown in which the superstructure 16 is made of steel, the superstructure 16 may be made of other structural materials. For example, the superstructure 16 may be made of reinforced concrete or steel-reinforced concrete. [Explanation of Symbols]

[0074] 10. Seismic isolation structure 12 Substructure 12b Pedestal 12c Protruding part (an example of a support part) 14. Seismic isolation device 16 Superstructure 16b Beam material 30 Stopper member 30c Intermediate section (an example of an energy absorption section) 40 Load-bearing section 42 Load-bearing section 50 Cushioning material 70 Damping device

Claims

1. Substructure and An upper structure supported by the lower structure via a seismic isolation device, A stopper member is provided on one of the upper structure and the lower structure, and is projected downward or upward. A load-receiving portion is provided on the other side of the upper structure and the lower structure, and is facing the stopper member, The damping device, which has one end attached to the stopper member and the other end attached to a support provided on the other side of the upper structure and the lower structure, and which dampens vibrations by extending and retracting, A cushioning material is attached to the portion of the stopper member that faces the load-receiving portion, which will collide with the load-receiving portion. Between the portion of the stopper member where the cushioning material is provided and the portion of the stopper member to which one end of the damping device is attached, an energy absorbing portion is formed that has lower strength compared to the other portions. Seismic isolation structure.

2. The lower structure is provided with a base to which the seismic isolation device is attached, The stopper member is fixed to the beam of the upper structure. The load-receiving portion is fixed to the base and faces the stopper member, The seismic isolation structure according to claim 1.

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