Deformation suppressing device

Abstract

To provide a deformation restraining device capable of restraining deformation with the same distance and the same property in all horizontal directions.SOLUTION: A collision receiving beam 2 that is disposed in a seismic isolation layer 11 between a lower structure 12 and an upper structure 13 that are relatively displaceable in a horizontal direction, is fixed to a bottom portion of the upper structure 13, and has a space portion 21 formed therein, the space portion 21 being open downward and having a circular shape or a regular polygonal shape in plan view when viewed from a vertical direction; And a receiving column 5 coaxially arranged inside the annular steel plate 4 at an interval from the inner peripheral surface 41 of the annular steel plate 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a deformation suppression device. [Background technology]

[0002] A base isolation structure is a structure in which a base isolation layer is placed between the base of a building and the superstructure, and the large horizontal deformation of the base isolation layer during an earthquake reduces the acceleration response of the superstructure, allowing the base isolation layer to efficiently absorb input energy.Because the base isolation structure can significantly reduce the response acceleration of the superstructure even during a major earthquake, it not only prevents structural damage to the building, but also achieves high seismic performance that allows the building to maintain its functionality after an earthquake.

[0003] In recent years, the level of earthquake motion that must be considered when designing buildings has been increasing. Concerns have been raised about long-period, extended-duration earthquake motions due to mega-earthquakes in the Nankai Trough or Sagami Trough, as well as long-period pulse earthquake motions due to inland active fault earthquakes such as the Uemachi Fault. In particular, long-period pulse earthquake motions, such as those observed in the 2016 Kumamoto earthquake, can cause excessive displacement in the seismic isolation layer of a base-isolated building, exceeding its clearance. Even increasing the damping amount by adding dampers makes it difficult to sufficiently suppress the displacement. To address this excessive deformation of the base-isolated layer, methods have been proposed for suppressing displacement, such as by installing stoppers (see, for example, Patent Documents 1 and 2). Crash buffer materials have also been proposed to mitigate the impact when the superstructure of a base-isolated building collides with a retaining wall (see, for example, Patent Documents 3 and 4).

[0004] Patent Document 5 discloses a deformation suppression device that suppresses excessive deformation of the seismic isolation layer and also functions as a collision buffer. This deformation suppression device is a stopper made of a beam and a deformable member (such as a beam), and the deformable member bears the load and absorbs kinetic energy through plastic deformation. In addition, a buffer member is provided on one of the collision surfaces of the beam and the deformable member to reduce the impact of the collision. For example, as disclosed in Patent Document 4, a buffer member can be used as this buffer member, which is made of chip-shaped elastic material such as rubber chips formed into a predetermined shape and has a void inside. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-134300 [Patent Document 2] Japanese Patent Publication No. 2022-172852 [Patent Document 3] Patent Publication No. 2022-7100 [Patent Document 4] Japanese Patent Publication No. 2022-63715 [Patent Document 5] Japanese Patent Publication No. 2023-26808 Summary of the Invention [Problem to be solved by the invention]

[0006] The deformation suppression device disclosed in Patent Document 5 has a mechanism for suppressing deformation in one horizontal direction, so to suppress deformation of the seismic isolation layer in two horizontal directions, it is necessary to install a deformation suppression device in each direction. If a deformation suppression device is installed to suppress deformation of the seismic isolation layer in two orthogonal horizontal directions, the distance until it hits the stopper becomes longer in directions oblique to the two horizontal directions, resulting in a problem of greater deformation.

[0007] Therefore, an object of the present invention is to provide a deformation suppression device that can suppress deformation at the same distance and with the same properties in all horizontal directions. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the deformation suppression device of the present invention is arranged in a seismic isolation layer between a lower structure and an upper structure which are capable of relative displacement in the horizontal direction, and comprises: a collision beam which is fixed to the bottom of the upper structure or to the upper part of the lower structure and has a hollow portion on the inside which is open downward or upward and has a circular or regular polygonal shape in a plan view when viewed from the vertical direction; a collision buffer portion which is provided in an annular shape along the inner peripheral surface of the collision beam; an annular steel plate which is provided along the inner peripheral surface of the collision buffer portion; and a support pillar which is fixed to the lower structure or the upper structure and is arranged coaxially inside the annular steel plate at a distance from the inner peripheral surface of the annular steel plate which protrudes upward from the upper surface of the lower structure or protrudes downward from the lower surface of the upper structure.

[0009] In the present invention, a support column fixed to the lower structure is arranged coaxially inside the annular steel plate. As a result, when the lower structure and the upper structure undergo relative horizontal displacement, the support column and the annular steel plate collide with each other with the same relative displacement regardless of the horizontal direction of the relative displacement, and the impact is buffered by the collision buffer, suppressing the relative displacement. In other words, the deformation suppression device can suppress deformation at the same distance and with the same properties in all horizontal directions. As a stopper mechanism that suppresses excessive deformation of the seismic isolation layer due to a major earthquake, it can operate at the same distance and with the same properties in all horizontal directions. Because the deformation suppression device of the present invention is a stopper mechanism that can be used in all horizontal directions, fewer stoppers can be installed than stoppers that can be used in only one horizontal direction.

[0010] In the deformation suppression device according to the present invention, the collision buffer portion may be formed of a plurality of collision buffer materials arranged in an annular shape along the inner peripheral surface of the collision-receiving beam.

[0011] With this configuration, if the collision buffer section is damaged by a collision, it is possible to replace only the collision buffer material in the damaged portion. [Effects of the Invention]

[0012] According to the present invention, deformation can be suppressed in all horizontal directions at the same distance and with the same properties. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view of a deformation suppression device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of a deformation suppression device according to an embodiment of the present invention. [Figure 3] FIG. 10 is a diagram showing a state in which the impact buffer is compressed by a cylinder. [Figure 4] FIG. 10 is a diagram showing a state in which the impact buffer is compressed by a flat plate. [Figure 5] FIG. 1 is a diagram showing a test device for a load test. [Figure 6] 10 is a graph showing the results of a loading test. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A deformation suppression device according to an embodiment of the present invention will now be described with reference to FIGS. As shown in FIG. 1, the deformation suppression device 1 according to this embodiment is provided in a seismic isolation layer 11 of a building. The seismic isolation layer 11 is provided between a lower structure 12, which is capable of relative displacement in the horizontal direction, and an upper structure 13. The lower structure 12 is, for example, the foundation of the building. A seismic isolation device is provided in the seismic isolation layer 11. The deformation suppression device 1 suppresses excessive deformation of the lower structure 12 and the upper structure 13 that exceeds a predetermined value.

[0015] The deformation suppression device 1 includes a collision receiving beam 2, a collision buffer 3, an annular steel plate 4, and a support column 5. The collision receiving beam 2 is provided at the bottom of the upper structure 13. The collision receiving beam 2 is annular. A hollow portion 21 having a circular shape in a plan view when viewed from the vertical direction is formed inside the collision receiving beam 2. The hollow portion 21 is closed at the top by the upper structure 13 and is open at the bottom.

[0016] The collision buffer 3 is provided in an annular shape along the inner peripheral surface 22 of the collision beam 2. The collision buffer 3 is formed of a material capable of absorbing impact, such as an elastic material such as rubber, or a material in which chip-like elastic material such as rubber chips is formed into a predetermined shape and has an internal void, as disclosed in Patent Document 4. By forming the collision buffer 3 from such a material, periodic maintenance can be eliminated or reduced. The collision buffer 3 is fixed to the inner peripheral surface 22 of the collision beam 2. The collision buffer 3 of this embodiment has multiple collision buffers 32. The multiple collision buffers 32 are arranged in an annular shape along the inner peripheral surface 22 of the collision beam 2. The collision buffer 3 is a member that receives a load, as described below. The collision buffer 3 may be formed of materials other than those mentioned above, except for the load-bearing portions, such as the connection portion with the collision beam 2.

[0017] The annular steel plate 4 is provided in a circular shape along the inner circumferential surface 31 of the collision buffer 3. The annular steel plate 4 is attached to the upper structure 13. However, the annular steel plate 4 is attached in a manner that prevents the horizontal load during a collision from being directly transmitted to the upper structure 13 (for example, by hanging it from the upper structure 13 using a hanging member with no horizontal rigidity or in a manner that allows horizontal displacement). The thickness of the annular steel plate 4 can be set arbitrarily as long as it is sized to inscribe the inner circumferential surface of the collision buffer 3. However, to obtain the cushioning effect of the collision buffer 3, it is desirable to set the plate thickness to, for example, 25 mm or more. The material type of the annular steel plate 4 can be set arbitrarily depending on the required performance. For example, a design that does not allow plastic deformation using a high-strength material or a design that expects energy absorption through plastic deformation using a low-yield-point steel is possible. The collision receiving beam 2, the collision buffer portion 3 and the annular steel plate 4 are arranged coaxially with their respective axes extending in the vertical direction. The collision buffer section 3 is made of a material whose characteristics have been clearly established through load tests, etc., and the annular steel plate 4 is made of a steel plate that is commonly used in construction and whose characteristics are clear. This allows the characteristics of the deformation suppression device 1 to be clearly set, and makes it possible to analytically study the behavior of the building when in operation.

[0018] The support pillar 5 protrudes upward from the upper surface of the lower structure 12. The upper side of the support pillar 5 is arranged inside the annular steel plate 4. The support pillar 5 is cylindrical. The support pillar 5 is fixed to the lower structure 12. The outer diameter of the support pillar 5 is smaller than the inner diameter of the annular steel plate 4. Under normal conditions when the lower structure 12 and the upper structure 13 are not displaced relative to each other, the support pillar 5 is arranged at the center of the annular steel plate 4 with a gap between it and the inner peripheral surface 41 of the annular steel plate 4. The support pillar 5 is arranged coaxially with the collision receiving beam 2, the collision buffer 3, and the annular steel plate 4.

[0019] When the lower structure 12 and the upper structure 13 are displaced relative to each other in the horizontal direction, the support column 5 and the annular steel plate 4 are displaced relative to each other in the horizontal direction. If the amount of displacement exceeds the normal distance D1 between the annular steel plate 4 and the support column 5, the annular steel plate 4 and the support column 5 collide. The collision between the annular steel plate 4 and the support column 5 is transmitted from the annular steel plate 4 to the collision buffer 3, and is absorbed by the collision buffer 3 and then received by the collision receiving beam 2, which limits the displacement to within a predetermined horizontal displacement. Because the annular steel plate 4 is annular and the support column 5 is cylindrical, the annular steel plate 4 and the support column 5 come into contact at the same distance of relative displacement in all horizontal directions, and further relative displacement is restricted. The characteristics are also the same in all directions.

[0020] When the collision buffer 3 is made of an elastic material such as rubber or a chip-shaped elastic material such as rubber chips formed into a predetermined shape with an internal void, applying force directly to the collision buffer 3 using a cylindrical support pillar 5 may not provide sufficient cushioning. This is because, as shown in Figures 3 and 4, the deformation characteristics of the collision buffer 3 vary depending on the force application conditions. As shown in Figure 3, when a collision buffer 3A is applied using a cylindrical pillar 301 smaller than its surface, the entire collision buffer 3A does not compress and deform, preventing the expected compressive load from being exerted and resulting in insufficient cushioning. As shown in Figure 4, when a collision buffer 3A of a predetermined size is applied using a flat plate 303 larger than its surface 302, the entire collision buffer 3A is compressed and provides cushioning. The cylindrical pillar 301 corresponds to the support pillar 5, and the flat plate 303 corresponds to the annular steel plate 4. Therefore, as described above, by colliding the support pillar 5 and the collision buffer 3 through the annular steel plate 4, the entire collision buffer 3 can be compressed. This allows the impact buffer 3 to efficiently absorb the impact.

[0021] As shown in Figure 5, a test was conducted in which multiple collision buffers 32B arranged on an arc were pressurized with a semicircular cylinder 5B. In the load test, two cases were conducted: one in which the collision buffers 32B were pressurized with the semicircular cylinder 5B via a semicircular steel plate 4B, and the other in which the collision buffers 32B were pressurized directly with the semicircular cylinder 5B. The collision buffers 32B are components made of chip-shaped elastic material, such as rubber chips, formed into a predetermined shape with an internal void. The width of the semicircular steel plate 4B is the same as the width of the collision buffers 32B. In the load test, force was applied to the ends of the aligned collision buffers 32B.

[0022] Figure 6 shows the load-deformation relationship of the loading test results. The test results for "with annular steel plate" correspond to the case where pressure was applied via semicircular steel plate 4B, while those for "without annular steel plate" correspond to the case where pressure was applied directly without semicircular steel plate 4B. In the case with annular steel plate, the load gradually increases from the small displacement range. However, in the case without annular steel plate, the load does not increase significantly until a displacement of approximately 70 mm, and then the load rises sharply once the displacement exceeds 70 mm. In the case without annular steel plate, the impact buffer 32B exerts almost no load, and after the impact buffer 32B is completely crushed, the impact beam 2 bears the load, resulting in a sudden increase in load. On the other hand, in the case with annular steel plate, a buffering effect is exerted with a gradually increasing load, confirming that the impact buffering effect of impact buffer 32B can be obtained by using annular steel plate.

[0023] Next, the operation and effect of the deformation suppression device according to this embodiment will be described. In the deformation suppression device 1 according to this embodiment, the support pillar 5 fixed to the lower structure 12 is arranged coaxially inside the annular steel plate 4. As a result, when the lower structure 12 and the upper structure 13 are displaced relative to each other in the horizontal direction, the support pillar 5 and the annular steel plate 4 collide with each other with the same relative displacement regardless of the horizontal direction in which the relative displacement occurs, and the impact is buffered by the collision buffer 3, thereby suppressing the relative displacement. In other words, the deformation suppression device 1 according to this embodiment can suppress deformation at the same distance and with the same properties in all horizontal directions. It can function as a stopper mechanism that suppresses excessive deformation of the seismic isolation layer due to a massive earthquake with the same distance and with the same properties in all horizontal directions. The deformation suppression device 1 according to this embodiment is a stopper mechanism that is compatible with all horizontal directions, and therefore the number of stoppers that can be installed can be reduced compared to stoppers that are compatible with one horizontal direction.

[0024] The collision buffer 3 is formed by a plurality of collision buffer materials 32 arranged along the inner peripheral surface 22 of the collision-receiving beam 2. As a result, if the collision buffer 3 is damaged by a collision, it is possible to replace only the damaged collision buffer material 32.

[0025] The collision buffer 3 is fixed to the collision beam 2, and the annular steel plate 4 is installed on the upper structure 13. If both the collision buffer 3 and the annular steel plate 4 are damaged or deteriorated, only the damaged or deteriorated member can be replaced.

[0026] Although the embodiment of the deformation suppression device according to the present invention has been described above, the present invention is not limited to the above embodiment and can be modified as appropriate within the scope of the invention. For example, in the above embodiment, a plurality of collision buffers 3 are arranged along the inner peripheral surface 22 of the collision-receiving beam 2, but they may be a single member. The number of collision buffers 3 to be installed is set arbitrarily depending on the characteristics of the collision buffers 3 and the required cushioning effect. The shape of the hollow space 21 inside the collision-receiving beam 2 in a plan view may be other than circular. The shape of the hollow space 21 inside the collision-receiving beam 2 in a plan view may be, for example, a polygon, or a regular polygon such as a regular hexagon or a regular octagon. The collision buffer 3 and the annular steel plate 4 may also be arranged in a polygonal ring shape instead of a circular ring shape. The support pillar 5 may be a rectangular pillar other than a circular pillar, or a pillar shape whose cross section is a polygon or a regular polygon.

[0027] The collision receiving beam 2 and the support pillar 5 may be upside down, or the collision receiving beam 2 may be fixed to the lower structure 12 and the support pillar 5 may be fixed to the upper structure 13. In such a case, the collision receiving beam 2 is provided on top of the lower structure 12. The hollow space 21 inside the collision receiving beam 2 is closed at the bottom by the lower structure 12 and is open at the top. The support pillar 5 protrudes downward from the bottom surface of the upper structure 13. The lower side of the support pillar 5 is located inside the annular steel plate 4. The annular steel plate 4 is installed on the lower structure 12.

[0028] The Sustainable Development Goals (SDGs) are 17 international goals adopted at the United Nations Summit in September 2015. The deformation suppression device according to this embodiment can contribute to achieving one of the 17 SDGs, such as goal 9, "Create inspiring infrastructure, promote inclusive and sustainable industrialization, and foster innovation." [Explanation of symbols]

[0029] 1. Deformation suppression device 2. Collision beam 3 Collision buffer 4 Annular steel plate 5 Support pillar 11 Seismic isolation layer 12 Undercarriage 13 Superstructure 21 Sky Section 22 Inner surface 31 Inner surface 32 Collision cushioning material 41 Inner surface

Claims

1. It is disposed in the seismic isolation layer between the lower structure and the upper structure, which are relatively displaceable in the horizontal direction, an impact beam fixed to the bottom of the upper structure or the top of the lower structure, the impact beam having an inner hollow portion that is open downward or upward and has a circular or regular polygonal shape in a plan view when viewed from the vertical direction; a collision buffer portion provided annularly along an inner peripheral surface of the collision receiving beam; an annular steel plate provided along an inner peripheral surface of the collision buffer portion; a support pillar fixed to the lower structure or the upper structure, the support pillar being arranged coaxially with and spaced apart from the inner peripheral surface of the annular steel plate inside the annular steel plate that protrudes upward from the upper surface of the lower structure or protrudes downward from the lower surface of the upper structure.

2. The deformation suppression device according to claim 1 , wherein the collision buffer portion is formed of a plurality of collision buffer materials arranged in an annular shape along the inner peripheral surface of the collision-receiving beam.

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