JP6499411B2 - Seismic isolation building - Google Patents

Description

  The present invention relates to a seismic isolation building having a seismic isolation structure.

In buildings such as buildings and condominiums, various seismic isolation structures are widely used to suppress vibrations input from the ground to the building during an earthquake.
In Patent Document 1, in a building having a large aspect ratio and a large aspect ratio with respect to the horizontal dimension of the building, the outer periphery of the upper structure is located in the vicinity of the seismic isolation layer provided between the foundation structure and the upper structure. A configuration having a hook-shaped weight on the portion is disclosed. According to such a configuration, by providing a bowl-shaped weight in the vicinity of the base isolation layer, the force to resist the overturning moment received by the superstructure during an earthquake is increased, and the base isolation performance of the building is increased. It is increasing.

JP 2002-54323 A

However, when building a building on a narrow land, as in the configuration disclosed in Patent Document 1, it may be difficult to secure a space for providing a bowl-shaped weight projecting on the outer peripheral portion of the upper structure. By providing a weight, the floor area of the building is reduced.
An object of the present invention made there is to provide a base-isolated building that can obtain a high base-isolation performance while ensuring a maximum floor area even in a narrow land.

The present invention employs the following means in order to solve the above problems.
That is, the present invention includes a lower structure constructed in the ground, an upper structure provided above the lower structure, and a seismic isolation layer provided between the lower structure and the upper structure. The upper structure has a plurality of upper and lower floors, and the lower floor slabs are heavier than the upper floor slabs.
According to such a base-isolated building, since the lower slab of the upper structure is heavier than the upper slab, the upper structure has a low center of gravity. As a result, it is possible to suppress the overturning moment received by the upper structure during an earthquake or the like without providing any additional material on the outer periphery of the upper structure.

The lower slab of the upper structure may be formed thicker than the upper slab.
Thereby, the slab of a lower floor can be made heavier than the slab of an upper floor, and the low center of gravity of an upper structure can be implement | achieved easily.

The upper slab of the upper structure may be a void slab having a hollow portion.
Thereby, the slab of the upper floor can be reduced in weight. This also makes it possible to lower the center of gravity of the upper structure.
Further, by using the void slab, it is possible to ensure soundproofing while reducing the thickness of the slab, so that the center of gravity of the upper structure can be lowered more effectively.

Further, the upper floor of the upper structure may be a non-beam / column-free structure in which a frame is formed only from the slab and walls.
Thereby, weight reduction of the whole frame of an upper floor can be achieved, and the low center of gravity of an upper structure can be achieved.

Further, the lower end portion of the upper structure may be provided with an outer wall inclined from the upper side to the lower side toward the inside of the building, and with a horizontal gap between the lower end portion and the outer peripheral portion of the lower structure. .
Thereby, even when the lower structure of the base-isolated building is constructed over the entire site, it is possible to secure a gap that allows the upper structure to be displaced in the horizontal direction due to an earthquake or wind. In addition, a large floor area can be secured in a portion above the lower end of the upper structure.

  According to the base-isolated building of the present invention, by reducing the center of gravity of the superstructure, it is possible to increase the force in the base-isolated layer to resist the overturning moment that the superstructure receives during an earthquake. Therefore, the seismic isolation effect in the seismic isolation layer can be effectively exhibited, and even in a narrow land, it is possible to obtain high seismic isolation performance while ensuring the maximum floor area.

It is an elevation sectional view of a base-isolated building concerning this embodiment. It is a perspective view which shows the frame structure of the said seismic isolation building. It is an elevation sectional view showing the composition of the lower part of a base-isolated building. It is a plane sectional view showing composition of each floor of a base-isolated building. It is a sectional elevation showing an example of a columnar void slab. It is a top view which shows the example of arrangement | positioning of the seismic isolation bearing in a seismic isolation layer. It is an elevation sectional view showing an example of a laminated rubber bearing as a seismic isolation bearing. It is an elevation sectional view showing an example of an elastic sliding bearing as a seismic isolation bearing. It is an elevation sectional view showing an example of a linear motion rolling bearing as a seismic isolation bearing. It is an elevation sectional view showing an example of an oil damper as a seismic isolation device.

Hereinafter, with reference to an accompanying drawing, a form for carrying out a seismic isolation building by the present invention is explained based on a drawing.
FIG. 1 is a vertical sectional view of the base-isolated building according to the present embodiment. FIG. 2 is a perspective view showing a frame configuration of the base-isolated building. FIG. 3 is an elevational sectional view showing a configuration of the lower part of the base-isolated building.
As shown in FIGS. 1 and 2, the seismic isolation building 10 includes a lower structure 11 that is a basic structure, an upper structure 12, and a seismic isolation layer 13 provided therebetween.

  The seismic isolation building 10 has a substantially rectangular shape in plan view, and the direction along the short side 10a is defined as the frontage direction X, and the direction along the long side 10b is defined as the depth direction Y. The base-isolated building 10 has, for example, a length in the frontage direction X of about 7 m, a length in the depth direction Y of about 20 m, and a dimension in the height direction H of about 33 m, for example. Thus, the seismic isolation building 10 is a building having a large dimension in the height direction H with respect to the length in the frontage direction X and a large so-called aspect ratio.

  The lower structure 11 transmits the load of the base-isolated building 10 and the external force that acts on the base-isolated building 10 during an earthquake or the like to the ground G. This lower structure is firmly supported in the ground G by an appropriate type of foundation structure such as a direct foundation or a pile foundation. In this embodiment, the lower structure 11 is formed below the surface Gf of the ground G in the seismic isolation building 10.

  As shown in FIG. 3, the lower structure 11 is formed by, for example, a reinforced concrete structure. The lower structure 11 is installed at the bottom of the foundation pit 14 excavated and formed in the ground G, and is formed so as to rise along the inner surface of the foundation pit 14 from the outer periphery of the base portion 15 located in the horizontal plane. The retaining wall portion 16 is integrally provided. In this embodiment, it is assumed that the basic pit 14 is formed over the entire site of the seismic isolation building 10.

  The upper structure 12 constitutes a ground floor portion above the base isolation layer 13 in the base isolation building 10. In this embodiment, each floor of the upper structure 12 is open on both sides in the depth direction Y.

FIG. 4 is a cross-sectional plan view showing the configuration of each floor of the base-isolated building.
As shown in FIG. 4, in the upper structure 12, on one end side in the depth direction Y, the elevator 18 and the staircase 19 are collectively arranged at a portion protruding to one side in the frontage direction X. Thereby, the indoor space R of each floor can be effectively used as a rectangular shape in plan view.

As shown in FIGS. 1 and 2, the lower floor portion (lower floor) 12 </ b> L of the upper structure 12 constitutes, for example, the first to fourth floor portions.
The lower floor portion 12L of the upper structure 12 includes a slab 21 formed at intervals in the vertical direction, and wall portions (walls) 22 formed along the depth direction Y at both end portions of the slab 21. ing. Each floor of the lower floor portion 12L has a cylindrical shape that is continuous in the depth direction Y by the upper and lower slabs 21 and 21 and the wall portions 22 and 22 on both sides.

  Such a lower floor portion 12L is formed of, for example, a steel structure, a reinforced concrete structure, a steel reinforced concrete structure, or the like. For example, the column 22c and the beam 22b of the lower floor portion 12L are formed of reinforced concrete to form a frame. Moreover, the slab 21 and the wall part 22 of the lower floor part 12L are formed by construction methods, such as precast concrete, half precast concrete, or cast-in-place concrete.

  In the lower floor 12L, the first floor slab (lower slab) 21A is formed thicker than the slabs 21 on the other floors. The slab 21A of the first floor portion can have a thickness of 1 m, for example.

As shown in FIG. 3, in the lower floor portion 12 </ b> L, the wall portion (outer wall) 22 </ b> A of the first floor portion is formed to be inclined inward in the frontage direction X of the seismic isolation building 10 from the upper side to the lower side. ing. Accordingly, the lower end portion of the wall portion 22A and the retaining wall portion 16 of the lower structure 11 are opposed to each other with a gap S therebetween in the horizontal direction. The gap S prevents the lower end portion of the wall portion 22A from interfering with the retaining wall portion 16 of the lower structure 11 even if the upper structure 12 is displaced in the horizontal direction during an earthquake. Further, the inclined wall portion 22A can secure a large floor area in the upper layer portion of the upper structure 12 than the second floor.
An expansion joint 50 is provided between the lower end portion of the wall portion 22A and the retaining wall portion 16 of the lower structure 11 to prevent the fall. The expansion joint 50 closes the gap S between the lower end portion of the wall portion 22A and the retaining wall portion 16 of the lower structure 11, and connects the lower end portion of the wall portion 22A and the retaining wall portion 16 of the lower structure 11 to each other. It allows horizontal displacement.

As shown in FIGS. 1 and 2, the upper floor portion (upper floor) 12H of the upper structure 12 constitutes, for example, a 5th to 8th floor portion. The frame of the upper floor portion 12H does not use a steel frame, and each floor portion is formed on both sides of the slab portion (upper floor slab) 25 provided at an interval in the vertical direction and the front direction X of the slab portion 25. Each of the wall portions 26 extends along the depth direction Y, and has a no-column / no-beam thin wall floor structure. In this way, each floor portion of the upper floor portion 12H has a rectangular cross-section that is continuous in the depth direction Y by the slab portions 25, 25 positioned above and below and the wall portions 26, 26 positioned on both sides in the short side 10a direction. It is cylindrical and has the same configuration as a so-called box culvert.
Such an upper floor portion 12H can be formed by on-site reinforced concrete construction, half precast concrete construction, precast concrete construction, or the like.

Further, each slab portion 25 of the upper floor portion 12H is formed by a columnar void slab.
FIG. 5 is an elevational sectional view showing an example of a columnar void slab. As shown in FIG. 5, the columnar void slab constituting the slab portion 25 is a state in which a columnar body 27 made of a foamed resin material and a cylindrical body made of metal, paper, etc. are disposed between the reinforcing bars 25a. It is formed by placing concrete 25b. The slab portion 25 is reduced in weight by forming a hollow portion without the concrete 25b being placed in the columnar body 27 or the cylindrical body portion.
In this embodiment, the slab portion 25 is thinner than the slab 21A of the first floor portion of the lower floor portion 12L, and has a thickness of, for example, 300 mm.

FIG. 6 is a plan view showing an example of arrangement of seismic isolation bearings in the seismic isolation layer. FIG. 7 is an elevational sectional view showing an example of a laminated rubber bearing as a seismic isolation bearing. FIG. 8 is an elevational sectional view showing an example of an elastic sliding bearing as a seismic isolation bearing. FIG. 9 is a vertical sectional view showing an example of a linear motion rolling bearing as a seismic isolation bearing. FIG. 10 is an elevational sectional view showing an example of an oil damper as a seismic isolation device.
The seismic isolation layer 13 is provided in order to install a seismic isolation bearing device that structurally separates the upper structure 12 and the lower structure 11 and to ensure clearance so that the upper structure 12 and the lower structure 11 do not collide during an earthquake. ing. The seismic isolation layer 13 is configured by providing a plurality of types of seismic isolation bearings between the base portion 15 of the lower structure 11 and the slab 21 </ b> A of the first floor portion of the upper structure 12.
As shown in FIG. 6, as the seismic isolation bearing constituting the seismic isolation layer 13, for example, a laminated rubber bearing 31, an elastic sliding bearing 32, a linear motion rolling bearing 33, and an oil damper 34 can be provided.

As shown in FIG. 7, the laminated rubber support 31 has a configuration in which a disk-like rubber layer 31c and a metal plate layer 31d are laminated in a plurality of layers in the vertical direction between a pair of upper and lower base plates 31a and 31b. . The rubber layer 31c is formed of a rubber material such as natural rubber or synthetic rubber. The metal plate layer 31d can be made of a seismic steel plate or the like in addition to a general metal material.
The laminated rubber bearing 31 provides torsional rigidity about the vertical axis of the entire building that is generated between the lower structure 11 and the upper structure 12.

  Such a laminated rubber bearing 31 is inserted between the lower structure 11 and the upper structure 12 after the upper structure 12 is constructed on the lower structure 11 and the seismic isolation layer 13 so as not to bear the load of the upper structure 12. It is preferable to do this. Thereby, even if the outer diameter of the rubber layer 31c is small, sufficient resilience characteristics can be exhibited when a large displacement occurs when a large earthquake occurs.

  As shown in FIG. 8, the elastic sliding bearing 32 is similar to the laminated rubber bearing 31, and upper and lower base plates 32 a and 32 b, laminated rubber bearing portions 32 s formed by alternately laminating rubber layers 32 c and metal plate layers 32 d, It has. The elastic sliding bearing 32 further includes sheet-like sliding materials 32t and 32u having a small friction coefficient made of PTFE (polytetrafluoroethylene), stainless steel plate, or the like on the upper side or the lower side of the laminated rubber bearing portion 32s.

In the elastic sliding bearing 32, each rubber layer 32c is deformed when the deformation due to the horizontal displacement generated between the lower structure 11 and the upper structure 12 is small. Further, when the force generated by the deformation of the rubber layer 32c exceeds the frictional force between the laminated rubber support portion 32s and the sliding material 32t, the laminated rubber support portion 32s slides in the horizontal direction on the sliding material 32t.
Such an elastic sliding bearing 32 is disposed in order to exert resistance to wind sway. Therefore, the elastic sliding bearing 32 is preferably arranged at a position where the axial force fluctuation is relatively small.

  As shown in FIG. 9, the linear motion rolling support 33 includes a guide rail 33a and a block 33c that is slidably provided along a guide rail 33a via a roller (not shown). 33f. The linear motion guide portion 33f includes two sets of guide rails 33a and blocks 33c, and is provided to be slidable in directions orthogonal to each other in a horizontal plane.

  Here, in the linear motion rolling support 33, the block 33c is engaged with the guide rail 33a via a roller (not shown) and is restrained in the vertical direction. Therefore, it is preferable to arrange the linear motion rolling bearing 33 at the corner of the base isolation layer 13 where a pulling force may be generated during an earthquake.

  As shown in FIG. 10, the oil damper 34 is connected to one of the lower structure 11 and the upper structure 12 and to the other of the lower structure 11 and the upper structure 12 and is displaced in the horizontal direction within the cylinder 34a. A piston rod 34b that is made free, and a damper oil (not shown) that is enclosed in the cylinder 34a and attenuates the displacement of the piston rod 34b in the cylinder 34a.

  Such an oil damper 34 is installed so as to have an operation axis direction in the horizontal direction. The oil damper 34 attenuates the displacement in the torsional direction around the vertical axis that occurs between the lower structure 11 and the upper structure 12. For this reason, a plurality of oil dampers 34 are arranged on the outer peripheral portion of the seismic isolation layer 13 so as to be displaced in a direction along the frontage direction X and the depth direction Y, respectively.

According to the seismic isolation building 10 as described above, the upper structure 12 has a plurality of upper and lower floors, and the slab 21A of the lower floor part 12L is formed heavier than the slab part 25 of the upper floor part 12H. Specifically, the slab 21A of the lower floor portion 12L of the upper structure 12 is formed thicker than the slab portion 25 of the upper floor portion 12H. The slab portion 25 of the upper floor portion 12H of the upper structure 12 is formed of a void slab having a hollow portion. Furthermore, the upper floor portion 12H of the upper structure 12 is a no-beam / column-free structure in which a frame is formed only from the slab portion 25 and the wall portion 22.
With these configurations, the upper structure 12 has a low center of gravity. Thereby, the overturning moment which the superstructure 12 receives at the time of an earthquake can be suppressed. Therefore, in the seismic isolation layer 13, it is possible to increase the force for resisting the overturning moment received by the upper structure 12 during an earthquake. Moreover, it can suppress that the pulling-out force of an up-down direction acts on each seismic isolation bearing of the seismic isolation layer 13. FIG. Thereby, the seismic isolation effect can be effectively exhibited in the seismic isolation layer 13. As a result, even in a narrow land, it is possible to obtain high seismic isolation performance.

  Further, by using a void slab for the slab portion 25 of the upper floor portion 12H of the upper structure 12, it is possible to ensure soundproofing while making the slab portion 25 thinner. Accordingly, it is possible to reduce the weight of the entire casing of the upper floor portion 12H.

  The seismic isolation layer 13 includes a plurality of types of seismic isolation devices such as a laminated rubber bearing 31, an elastic sliding bearing 32, a linear motion rolling bearing 33, and an oil damper 34. In this way, by combining a plurality of types of seismic isolation bearings, the seismic isolation layer 13 can effectively exhibit seismic isolation performance against various vibrations. Therefore, the displacement which arises between the upper structure 12 and the lower structure 11 by an earthquake, a wind, etc. can be reduced effectively.

Further, the wall portion 22A at the lower end portion of the lower structure 11 is inclined inwardly from the upper side to the inner side of the seismic isolation building 10 and horizontally between the retaining wall portion 16 constituting the outer peripheral portion of the lower structure 11. Are provided with a gap S therebetween.
Thereby, even when the lower structure 11 of the seismic isolation building 10 is constructed over the entire site, it is possible to secure a gap S that allows the upper structure 12 to be displaced in the horizontal direction due to an earthquake or a wind. Moreover, a large floor area can be secured in a portion above the lower end of the upper structure 12.

(Other embodiments)
In addition, the seismic isolation building of this invention is not limited to the above-mentioned embodiment described with reference to drawings, Various modifications can be considered in the technical scope.

Further, in the above embodiment, the slab 21A of the lower floor portion 12L of the upper structure 12 is formed to be heavier than the slab portion 25 of the upper floor portion 12H by being formed thicker than the slab portion 25 of the upper floor portion 12H. I was like that.
In addition to this, the slab portion 25 of the upper floor portion 12H is formed of lightweight concrete or foamed concrete, and the slab 21A of the lower floor portion 12L is ordinary concrete or heavy concrete having a weight greater than that of the slab portion 25 of the upper floor portion 12H. You may make it form in.

Further, not only the slab portions 25 and 21A but also the casing itself constituting the upper floor portion 12H and the lower floor portion 12L may be configured such that the lower floor portion 12L is heavy and the upper floor portion 12H is light.
For this purpose, for example, the lower floor portion 12L may be a reinforced steel concrete structure, and the upper layer portion 12H may be a steel structure.
Moreover, you may make it increase the area and number of openings, such as a window provided in the upper floor part 12H, compared with the lower floor part 12L.
Furthermore, for example, when attaching an outer wall material called a curtain wall or the like to the outer wall surface of the upper floor portion 12H or the lower floor portion 12L, the outer wall material of the upper floor portion 12H is thinned and the outer wall material of the lower floor portion 12L is It may be thicker.
These structures also lower the center of gravity of the upper structure 12.

Further, for example, the appearance of the base-isolated building 10, the planar shape, the specific structure of the lower structure 11, the number of floors and structure of the upper structure 12, the types and number of base-isolated supports provided in the base-isolated layer 13, the specific structure, etc. Unless departing from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.
The seismic isolation layer 13 is provided with a laminated rubber bearing 31, an elastic sliding bearing 32, a linear motion rolling bearing 33, and an oil damper 34. However, if at least two of these are provided as the seismic isolation bearing Furthermore, a seismic isolation device of a type other than the laminated rubber bearing 31, the elastic sliding bearing 32, the linear motion rolling bearing 33, and the oil damper 34 may be employed.

10 Base-isolated building 10a Short side 10b Long side 11 Lower structure 12 Upper structure 12H Upper floor (upper floor)
12L Lower floor (lower floor)
13 Seismic isolation layer 16 Retaining wall part 21 Slab 21A Slab (slab of lower floor)
22 Wall (wall)
22A Wall (outer wall)
25 Slab (upper slab)
26 Wall 27 Column 31 Laminated rubber bearing (Seismic isolation bearing)
32 Elastic sliding bearing (Seismic isolation bearing)
33 Linear motion rolling bearing (Seismic isolation bearing)
34 Oil damper (Seismic isolation device)
G Ground S Gap

Claims (4)

A lower structure including a base part and a retaining wall part built in the ground;
An upper structure provided above the lower structure;
A seismic isolation layer provided between the lower structure and the upper structure,
The upper structure has a plurality of floors above and below, and the lower floor slab is formed heavier than the upper floor slab ,
The lower end portion of the upper structure is provided with an outer wall located above the retaining wall portion inclined from the upper side to the lower side toward the inside of the building, with a horizontal gap between the outer structure and the outer peripheral portion of the lower structure. seismic isolation building, characterized in that is.   The seismic isolation building according to claim 1, wherein the lower floor slab of the upper structure is formed thicker than the upper floor slab.   The seismic isolation building according to claim 1 or 2, wherein the slab on the upper floor of the superstructure is a void slab having a hollow portion.   The seismic isolation building according to any one of claims 1 to 3, wherein the upper floor of the upper structure is a non-beam / column-free structure in which a frame is formed only from the slab and a wall.

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