Buildings equipped with seismic isolation devices

Abstract

To provide a building with a seismic isolation device capable of reducing construction costs.SOLUTION: In a building 1 with a seismic isolation device, a seismic isolation device 30 is provided between a lower structure 10 and an upper structure 20. The upper structure 20 has a foundation beam 23 extending horizontally at intervals with respect to the lower structure 10. A lower face side of the foundation beam 23 consists of a pair of inclined surfaces 23a extending obliquely upward from both end sides of the foundation beam 23 in the extending direction toward the center side so that the gap G with respect to the lower structure 10 is larger at the center side than at both end sides in the extending direction of the foundation beam 23.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a building with a seismic isolation device provided between a lower-side structure and an upper-side structure.

Background Art

[0002] As a conventional building with a seismic isolation device, there is known one that suppresses the sway of an upper-side structure by providing a seismic isolation device between a lower-side structure and an upper-side structure and making it difficult for the ground sway caused by an earthquake to be transmitted to the upper-side structure (see, for example, Patent Document 1).

[0003] In a conventional building with a seismic isolation device, a seismic isolation pit is formed in a lower-side structure, and the lower-side structure supports the upper-side structure through a seismic isolation device installed in the seismic isolation pit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a conventional building with a seismic isolation device, in order to allow an operator who inspects the seismic isolation device, mechanical equipment, electrical equipment, etc. to move in the seismic isolation pit, a gap (for example, 600 mm) through which the operator can move is formed between the lower surface of a foundation beam located below the upper-side structure and the bottom of the seismic isolation pit. For this reason, in a conventional building with a seismic isolation device, it is necessary to form a large height dimension of the lower-side structure, and at the same time, in order to install the lower-side structure with a large height dimension underground, it is necessary to increase the root cutting depth, and there is a risk of increasing the construction cost.

[0006] An object of the present invention is to provide a building with a seismic isolation device capable of reducing the construction cost. [Means for solving the problem]

[0007] The seismic isolation device building according to the present invention is a seismic isolation device building in which a seismic isolation device is provided between a lower structure and an upper structure, wherein the upper structure has a foundation beam that extends horizontally at a distance from the lower structure, and the lower surface of the foundation beam consists of a pair of inclined surfaces that extend diagonally upward from each of the ends in the direction of extension of the foundation beam toward the center, such that the gap with the lower structure is larger toward the center than toward the ends in the direction of extension of the foundation beam.

[0008] Furthermore, in the building with seismic isolation device according to the present invention, the foundation beam preferably has a plurality of main reinforcements extending along the direction of extension, and the main reinforcements located on the lower side of the foundation beam among the plurality of main reinforcements extend linearly along the inclined surface from both ends in the direction of extension of the foundation beam toward the central part, and a lap joint is formed on the central part.

[0009] Furthermore, the seismic isolation device-equipped building according to the present invention preferably has a high-strength section in which a plurality of the main reinforcements are provided at both ends of the foundation beam in the extending direction, thereby improving the strength of the other sections.

[0010] Furthermore, in the seismic isolation device building according to the present invention, preferably the foundation beam has a plurality of shear reinforcement bars extending along the upper surface, the lower surface, and both sides in the width direction, and each of the plurality of shear reinforcement bars consists of an upper side member located on the upper side of the foundation beam and a lower side member located on the lower side of the foundation beam, and a lap joint is formed between the upper side member and the lower side member.

[0011] Furthermore, in the seismic isolation device-equipped building according to the present invention, the lower structure preferably comprises a structural body and a pile extending downward from the lower part of the structural body, wherein the pile is joined to the structural body via a member capable of reducing the stress transmitted from the structural body.

[0012] Furthermore, in the building with seismic isolation device according to the present invention, the foundation beam preferably has a plurality of main reinforcements extending along the direction of extension, and the main reinforcement located on the lower side of the foundation beam has a bent portion on the central side in the direction of extension of the foundation beam, and extends linearly along the inclined surface from the bent portion toward each of the two ends. [Effects of the Invention]

[0013] According to the present invention, by forming the central portion of the gap between the lower structure and the lower surface of the foundation beam of the upper structure to a size that allows a person to pass through in the direction of extension of the foundation beam, it becomes possible for a person to move through the seismic isolation pit without increasing the height dimension of the lower structure, and it becomes possible to install the lower structure underground without increasing the excavation depth, thereby reducing construction costs. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a cross-sectional view of the main part of a building equipped with a seismic isolation device according to the first embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view of a foundation beam according to the first embodiment of the present invention. [Figure 3] Figure 3 is a cross-sectional view of the main part of a building equipped with a seismic isolation device according to a second embodiment of the present invention. [Figure 4] Figure 4 is a cross-sectional view of the main part of a building equipped with a seismic isolation device according to the third embodiment of the present invention. [Modes for carrying out the invention]

[0015] <First Embodiment> Figures 1 and 2 illustrate a first embodiment of the present invention; Figure 1 is a cross-sectional view of the main part of a building equipped with a seismic isolation device, and Figure 2 is a cross-sectional view of a foundation beam.

[0016] The seismic isolation device-equipped building 1 of this embodiment can be used, for example, as an apartment building constructed of steel-reinforced concrete (SRC) or reinforced concrete (RC).

[0017] The building 1 with a seismic isolation device includes a lower - side structure 10 excavated from the ground and installed underground, an upper - side structure 20 arranged above the lower - side structure 10, and a plurality of seismic isolation devices 30 installed between the lower - side structure 10 and the upper - side structure 20.

[0018] As shown in FIG. 1, the lower - side structure 10 has a mat foundation 11 as a structure main body and piles 12 extending downward from the lower part of the mat foundation 11.

[0019] The mat foundation 11 extends horizontally over the entire lower part of the upper - side structure 20, and by forming a wall part 11a whose outer peripheral part extends upward in the circumferential direction, a seismic isolation pit 11b where the seismic isolation device 30 is installed is formed on the upper surface side.

[0020] The pile 12 is a cylindrical member. The upper end part is connected to the lower surface of the mat foundation 11, and by reaching the support layer with high ground strength at the lower end side, the lower - side structure 10 is supported by the support layer. Also, the upper end part of the pile 12 is fixed to the lower surface of the mat foundation 11 through, for example, a ring 12a made of precast concrete to reduce the stress transmitted from the mat foundation 11 to the pile 12. Here, since no pulling force acts on the pile 12 in the building 1 with a seismic isolation device, it is not necessary to install tension - fixing bars between the mat foundation 11 and the pile 12.

[0021] The upper - side structure 20 includes a plurality of upper - side footings 22 to which the lower end parts of columns 21 are connected, and foundation beams 23 provided to connect adjacent upper - side footings 22 and extending horizontally at an interval with respect to the mat foundation 11.

[0022] The upper - side footing 22 is formed larger than the outer dimension of the column 21 and the width dimension of the foundation beam 23, and most of the load acts on it. The seismic isolation device 30 is arranged on the lower surface of the upper - side footing 22.

[0023] A horizontally extending plane is formed on the upper surface of the foundation beam 23. The lower surface of the foundation beam 23 consists of a pair of inclined surfaces 23a that extend diagonally upward from each end in the direction of extension toward the center. In other words, the depth of the foundation beam 23 is smaller on the central side than on the ends in the direction of extension. Therefore, the gap G between the lower surface of the foundation beam 23 and the upper surface of the raft foundation 11 of the lower structure 10 is larger on the central side than on the ends in the direction of extension of the foundation beam 23. The portion of the gap G between the upper surface of the raft foundation 11 and the lower surface of the foundation beam 23 on the central side in the direction of extension of the foundation beam 23 is formed to a size (e.g., 650 mm) that allows a person moving through the seismic isolation pit 11b to pass through.

[0024] The foundation beam 23 has a plurality of main reinforcement bars 23b extending along the direction of extension, and a plurality of shear reinforcement bars 23c that are spaced apart in the direction of extension and extend along the upper side, lower side, and both sides in the width direction.

[0025] Multiple main reinforcement bars 23b are arranged across the upper footing 22 and the foundation beam 23, and are reinforcing bars that extend along the upper or lower surface of the foundation beam 23. Of the multiple main reinforcement bars 23b, the main reinforcement bars 23b arranged on the lower surface of the foundation beam 23 extend linearly along the inclined surface 23a from each of the ends in the direction of extension of the foundation beam 23 toward the center, and intersect in the center to form a lap splice 23b1. The lap splice 23b1 is formed to be 50 times the length of the outer diameter of the main reinforcement bars 23b.

[0026] As shown in Figure 2, each of the multiple shear reinforcement bars 23c consists of an upper member 23c1 positioned on the upper surface and upper sides in the width direction of the foundation beam 23, and a lower member 23c2 positioned on the lower surface and lower sides in the width direction of the foundation beam 23. The upper member 23c1 and the lower member 23c2 are each formed into a U-shape by bending both ends of the reinforcement bar, and 180° hooks are formed at both ends. The shear reinforcement bars 23c are formed into lap joints 23c3 by overlapping both ends of the upper member 23c1 and both ends of the lower member 23c2. The lap joints 23c3 are formed to be at least 40 times the length of the outer diameter of the shear reinforcement bars 23c. The vertical size of the shear reinforcement bars 23c can be adjusted by adjusting the length of the lap joints 23c3 formed between the upper member 23c1 and the lower member 23c2.

[0027] Each of the multiple seismic isolation devices 30 is formed, for example, by alternately laminating rubber plates and steel plates, and is installed between the raft foundation 11 of the lower structure 10 and the upper footing 22 of the upper structure 20. The seismic isolation devices 30 allow the upper structure 20 to move horizontally relative to the lower structure 10 and apply a force to the lower structure 10 that returns the upper structure 20 to a predetermined position. It is preferable that the seismic isolation devices 30 have a small vertical size.

[0028] In the building 1 with seismic isolation devices configured as described above, since the seismic isolation device 30 is installed between the lower structure 10 and the upper structure 20, the horizontal force of an earthquake transmitted to the lower structure 10 is transmitted to the upper structure 20 via the seismic isolation device 30. For this reason, the upper structure 20 moves horizontally at a slower speed than the movement of the lower structure 10. Furthermore, when the input of the horizontal force of an earthquake to the lower structure 10 stops, the upper structure 20 returns to its predetermined horizontal position relative to the lower structure 10 due to the restoring force of the seismic isolation device 30.

[0029] Furthermore, the central portion of the foundation beam 23 in the direction of extension within the gap G between the upper surface of the raft foundation 11 of the lower structure 10 and the lower surface of the foundation beam 23 of the upper structure 20 is formed to a size that allows a person to pass through. Therefore, workers who inspect seismic isolation devices, mechanical equipment, electrical equipment, etc., can move through the seismic isolation pit 11b by passing between the upper surface of the raft foundation 11 and the central portion of the foundation beam 23 in the direction of extension.

[0030] Thus, according to the seismic isolation device of this embodiment, the seismic isolation device 30 is provided between the lower structure 10 and the upper structure 20, and the upper structure 20 has a foundation beam 23 that extends horizontally at a distance from the lower structure 10, and the lower surface of the foundation beam 23 consists of a pair of inclined surfaces 23a that extend diagonally upward from each of the ends in the direction of extension of the foundation beam 23 toward the center, such that the gap G with the lower structure 10 is larger toward the center than toward the ends in the direction of extension of the foundation beam 23.

[0031] This allows a person to pass through the central part of the foundation beam 23 in the direction of extension of the foundation beam 23 in the gap G between the upper surface of the raft foundation 11 of the lower structure 10 and the lower surface of the foundation beam 23 of the upper structure 20. As a result, it becomes possible to move through the seismic isolation pit 11b without increasing the height dimension of the lower structure 10, and it becomes possible to install the lower structure 10 underground without increasing the excavation depth, thereby reducing construction costs.

[0032] Furthermore, it is preferable that the foundation beam 23 has a plurality of main reinforcement bars 23b extending along the direction of extension, and that the main reinforcement bars 23b located on the lower side of the foundation beam 23 extend linearly along the inclined surface 23a from both ends in the direction of extension of the foundation beam 23 toward the center, and form a lap joint 23b1 in the center.

[0033] This makes it possible to position the main reinforcement bars 23b, located on the lower side of the foundation beam 23, along the shape of the lower surface of the foundation beam 23 without requiring bending of the main reinforcement bars 23b, thereby reducing the amount of work required at the construction site.

[0034] Furthermore, it is preferable that the foundation beam 23 has a plurality of shear reinforcement bars 23c extending along the upper surface, lower surface, and both sides in the width direction, and that each of the plurality of shear reinforcement bars 23c consists of an upper member 23c1 located on the upper side of the foundation beam 23 and a lower member 23c2 located on the lower side of the foundation beam 23, and that a lap joint 23c3 is formed between the upper member 23c1 and the lower member 23c2.

[0035] As a result, in foundation beams 23 with different beam depths depending on their position in the extension direction, it is possible to construct shear reinforcement bars 23c of different vertical sizes by adjusting the length of the lap joint 23c3, without requiring multiple types of shear reinforcement bars of different vertical sizes, thereby reducing construction costs.

[0036] Furthermore, it is preferable that the lower structure 10 includes a raft foundation 11 and piles 12 extending downward from the lower part of the raft foundation 11, and that the piles 12 are joined to the raft foundation 11 via rings 12a capable of reducing the stress transmitted from the raft foundation 11.

[0037] As a result, since the lower structure 10 does not require main reinforcement to connect the raft foundation 11 and the piles 12, it is not necessary to form a large footing in the lower structure 10, and the excavation depth can be reduced.

[0038] <Second Embodiment> Figure 3 shows a second embodiment of the present invention and is a cross-sectional view of the main part of a building equipped with a seismic isolation device. Components similar to those in the previous embodiment are denoted by the same reference numerals.

[0039] In this embodiment, the building 1 equipped with a seismic isolation device has high-strength sections 23b2 provided at both ends of the upper footing 22 and foundation beam 23 of the upper structure 20, which have improved strength compared to other sections.

[0040] The high-strength section 23b2 is made stronger than other sections by applying heat treatment to the portion of the reinforcing bar used as the main reinforcement 23b.

[0041] In the building 1 equipped with seismic isolation devices as described above, high-strength sections 23b2 are located in the main reinforcement bars 23b at both ends of the upper footing 22 and foundation beam 23, where large stresses act in the upper structure 20.

[0042] Thus, according to the seismic isolation device-equipped building of this embodiment, similar to the previous embodiment, by forming the central portion of the extension direction of the foundation beam 23 in the gap G between the upper surface of the raft foundation 11 of the lower structure 10 and the lower surface of the foundation beam 23 of the upper structure 20 to a size that allows a person to pass through, it becomes possible for a person to move through the seismic isolation pit 11b without increasing the height dimension of the lower structure 10, and it becomes possible to install the lower structure 10 underground without increasing the excavation depth, thereby reducing construction costs.

[0043] Furthermore, it is preferable that the multiple main reinforcements 23b are provided in the portions located at both ends in the extending direction of the foundation beam 23, and have high-strength portions 23b2 that have improved strength compared to other portions.

[0044] This makes it possible to ensure the necessary strength at both ends of the foundation beam, where large stresses are applied, without increasing the outer diameter of the main reinforcement bars or the number of main reinforcement bars used, thereby reducing the amount of reinforcement bars used.

[0045] <Third Embodiment> Figure 4 shows a third embodiment of the present invention and is a cross-sectional view of the main part of a building equipped with a seismic isolation device. Components similar to those in the previous embodiments are denoted by the same reference numerals.

[0046] In this embodiment, the building 1 with a seismic isolation device has a main reinforcement bar 23b located on the lower side of the foundation beam 23, which has a bent portion 23b3 on the central side in the extending direction of the foundation beam 23, and is formed to extend linearly along the inclined surface 23a from the bent portion 23b3 toward each of the two ends.

[0047] In the building 1 equipped with a seismic isolation device configured as described above, the main reinforcement bars 23b located on the lower side of the foundation beam 23 have a bent portion 23b3 located on the central side in the direction of extension of the foundation beam 23, and extend linearly along the inclined surface 23a toward each of the two ends.

[0048] Thus, according to the seismic isolation device-equipped building of this embodiment, similar to the previous embodiment, by forming the central portion of the extension direction of the foundation beam 23 in the gap G between the upper surface of the raft foundation 11 of the lower structure 10 and the lower surface of the foundation beam 23 of the upper structure 20 to a size that allows a person to pass through, it becomes possible for a person to move through the seismic isolation pit 11b without increasing the height dimension of the lower structure 10, and it becomes possible to install the lower structure 10 underground without increasing the excavation depth, thereby reducing construction costs.

[0049] Furthermore, the foundation beam 23 has a plurality of main reinforcement bars 23b extending along the direction of extension, and it is preferable that the main reinforcement bars 23b located on the lower side of the foundation beam 23 have a bent portion 23b3 on the central side in the direction of extension of the foundation beam 23, and extend linearly along the inclined surface 23a from the bent portion 23b3 toward each of the two ends.

[0050] As a result, since lap splices are not formed on the central side in the extension direction of the foundation beam, it becomes possible to reduce the amount of reinforcing steel used as the main reinforcement. [Explanation of symbols]

[0051] 1. Buildings equipped with seismic isolation devices 10 Lower structure 11. Slab foundation 12 stakes 12a ring 20 Upper structure 23 Foundation beam 23a Slope 23b Main bar 23b1 Overlap joint 23b2 High strength section 23b3 Bent part 23c Shear reinforcement 23c1 Upper side member 23c2 Lower side member 23c3 Overlap joint 30 Seismic isolation devices

Claims

1. A building equipped with seismic isolation devices, in which seismic isolation devices are installed between the lower structure and the upper structure, The upper structure has a foundation beam that extends horizontally at a distance from the lower structure, The lower surface of the foundation beam consists only of a pair of inclined surfaces that extend diagonally upward from each of the ends in the direction of extension of the foundation beam toward the center, such that the gap with the lower structure is larger on the central side than on the ends in the direction of extension of the foundation beam. A building equipped with seismic isolation devices.

2. The aforementioned foundation beam has multiple main reinforcements extending along the direction of extension, Of the multiple main reinforcements, the main reinforcement located on the lower side of the foundation beam extends linearly along the inclined surface from both ends in the direction of extension of the foundation beam toward the center, and forms a lap joint in the center. A building equipped with a seismic isolation device as described in claim 1.

3. Multiple of the aforementioned main reinforcements are provided in the portions located at both ends in the extending direction of the foundation beam, and have high-strength sections that have improved strength compared to other portions. A building with seismic isolation devices as described in claim 2.

4. The foundation beam has multiple shear reinforcements extending along the upper surface, the lower surface, and both sides in the width direction. Each of the multiple shear reinforcement bars consists of an upper member located on the upper side of the foundation beam and a lower member located on the lower side of the foundation beam. A lap joint is formed between the upper side member and the lower side member. A building equipped with a seismic isolation device as described in claim 1.

5. The lower structure comprises a structural body and a pile extending downward from the lower part of the structural body. The pile is joined to the main body of the structure via a member capable of reducing the stress transmitted from the main body of the structure. A building equipped with a seismic isolation device as described in claim 1.

6. The aforementioned foundation beam has multiple main reinforcements extending along the direction of extension, Of the multiple main reinforcements, the main reinforcement located on the lower side of the foundation beam has a bent portion on the central side in the extending direction of the foundation beam, and extends linearly along the inclined surface from the bent portion toward each of the two ends. A building equipped with a seismic isolation device as described in claim 1.

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