JP5667476B2 - Base-isolated buildings and methods for building base-isolated buildings - Google Patents

Description

  The present invention relates to a base-isolated building and a method for constructing a base-isolated building.

Seismic isolation buildings that separate the foundation and the superstructure are known as buildings that do not directly transmit the shaking of the earthquake to the superstructure.
In seismic isolation buildings, generally, the input acceleration is limited by installing a seismic isolation device such as a laminated rubber bearing or a sliding bearing between the foundation and the lower end of the superstructure column, thereby reducing the horizontal force during an earthquake. In addition to the reduction, the natural period of the upper structure is lengthened (for example, see Patent Document 1).

Such seismic isolation buildings are configured to support the upper structure on the seismic isolation device so that it can be displaced horizontally, and by increasing the rigidity of the foundation and concentrating deformation on the seismic isolation device, the necessary damping is achieved. The effect and natural period are controlled.
Further, by allowing the displacement in the horizontal direction to be controlled while controlling the displacement in the vertical direction, the fall is prevented.

Japanese Patent Laid-Open No. 11-293945

  In the case of a building with a large aspect ratio (height / width) that represents the ratio between the height and width of the building, due to the influence of rocking vibration and tipping moment that the whole building rotates and the vertical movement of the end increases during an earthquake, A large tensile force acts on the seismic isolation device.

Therefore, in the case of buildings with a large aspect ratio, a tensile force can be provided, such as installing a member to bear the tensile force on the seismic isolation device, placing a roller that restrains lifting, or installing a laminated rubber body to prevent falling. Therefore, it is necessary to construct a reinforcing structure against the above, and this reinforcing structure hinders cost reduction.
Moreover, since the same tensile axial force acts also on the pillar and foundation of a building main body, it is necessary also about a pillar and a foundation also to make it the high strength structure according to this tensile axial force.

  On the other hand, it is transmitted by pinning the seismic isolation device at the pile head and omitting the foundation beam, or omitting the foundation directly below the column located in the projected corner in plan view and reducing the rigidity of the foundation. In some cases, the horizontal force at the time of an earthquake may be reduced. However, in this case, the deformation of the foundation itself may be increased.

  Furthermore, in patent document 1, the lower end part of the column adjacent to the column located at the four corners is omitted, and the concentrated force acting on the seismic isolation device disposed at this position by concentrating the axial force at the four corners, Although the structure which cancels the tensile force at the time of an earthquake is disclosed, the superstructure is complicated, and there is a possibility that the design and construction will be troublesome and the cost may be increased.

  The present invention aims to solve the above-mentioned problems, and provides a seismic isolation building and a method for constructing a seismic isolation building that can be constructed at low cost without reducing the seismic isolation effect. The challenge is to propose.

Seismic isolation building of the present invention to solve such problems, seismic isolation layer to reduce the seismic input is provided to a predetermined hierarchy, building end rotates the entire building during an earthquake is vertically It is a seismic isolation building that moves and rocks, and in the seismic isolation layer, a seismic isolation device is not provided below the column located in at least four corners of the plane immediately above the seismic isolation layer . It is characterized by an insulating space capable of allowing ups and downs and a seismic isolation device installed below the other pillars.

Moreover, the construction method of the seismic isolation building of the present invention arranges the temporary support members corresponding to the positions of the pillars erected at at least four corners of the plane, and corresponds to the positions of the other pillars. A step of forming a base isolation layer by arranging a base isolation device; a step of constructing a casing above the base isolation layer in a state where a column is supported by the temporary support member and the base isolation device; and It is possible to remove the temporary support member after the construction has progressed to a predetermined height, and to allow the column to be lifted or submerged without providing a seismic isolation device below the column erected at the corner. Providing an insulating space.

According to such a base-isolated building and the method for constructing the base-isolated building, the base-isolated device under the pillars in at least four corners (outside corners) of the building body is omitted, and the axis that the adjacent base-isolated device bears By increasing the force, it is possible to prevent a large tensile force from acting on the seismic isolation device and to reduce the cost.
In other words, when a large seismic force is applied at the corners, the structure can be lifted and subducted, and does not bear the tensile axial force associated with rocking vibration. It is possible to omit the reinforcing structure against the axial force and the high strength structure.

  In addition, since the vertical load at the corner of the building body is small, the building stability can be maintained by transmitting it to the foundation via the seismic isolation device arranged under the column located next to it. .

  According to the base-isolated building and the construction method of the base-isolated building of the present invention, it is possible to construct the base-isolated building at a low cost without reducing the base-isolating effect even when the rocking vibration is expected to be dominant. Can do.

It is an elevation view which shows the outline | summary of the seismic isolation building which concerns on embodiment of this invention. It is a top view which shows the seismic isolation layer of the base isolation building shown in FIG. (A)-(c) is sectional drawing which shows each construction step of the construction method of a seismic isolation building. (A) And (b) is a top view which shows the other example of a seismic isolation building.

In the present embodiment, as shown in FIG. 1, a multi-story building body 10, a foundation 20 provided below the building body 10, and a seismic isolation layer provided between the building body 10 and the foundation 20. The base-isolated building 1 provided with 30 will be described.
In addition, the magnitude | size, shape, etc. of the seismic isolation building 1 are not limited. Further, the position of the seismic isolation layer 30 is not limited between the building body 10 and the foundation 20. The base-isolated building 1 may be a building having an underground structure.

  The building body 10 includes a plurality of pillars 11, 11,..., And beams 12, 13 laid horizontally between the pillars 11.

The beam 12 is provided at each level of the building body 10, and a lower end beam 13 that connects the lower ends of the columns 11 is provided at the lower end of the building body 10.
In the present embodiment, the lower end beam 13 is formed at a position dug down from the ground surface, but the position of the lower end beam 13 is not limited.

  The building body 10 has a rectangular shape in plan view. In addition, the shape of the building main body 10 is not limited. Further, the number of floors of the building body 10 is not limited.

As shown in FIG. 1, the foundation 20 is formed in the ground G under the building main body 10, and is formed with a gap between the lower end beam 13.
The foundation 20 includes a foundation slab 21 and a foundation pile 22. The configuration of the foundation 20 is not limited. For example, a foundation beam may be employed instead of the foundation slab 21 or an independent foundation may be employed.

The foundation slab 21 is a plate-like member formed below the lower end beam 13, and the head of the foundation pile 22 formed immediately below is fixed.
In this embodiment, the foundation slab 21 is formed at a position where the ground surface is dug down.

  In the present embodiment, as shown in FIG. 2, the basic slab 21 is formed in a rectangular shape in plan view. The shape of the foundation slab 21 is not limited to a rectangular shape, and may be formed as appropriate. Moreover, what is necessary is just to set the thickness (height) of the foundation slab 21 suitably according to the scale of the seismic isolation building 1.

As shown in FIG. 1, the foundation pile 22 is formed corresponding to the position of the column 11, and is formed on an extension line of the central axis of the column 11.
In addition, the positional relationship between the pillar 11 and the foundation pile 22 is not limited to this, and may be set as appropriate. The foundation pile 22 may be a support pile whose tip reaches the support layer, or may be a friction pile supported by a peripheral frictional force, and the support type of the foundation pile 22 is limited. is not.

  The seismic isolation layer 30 includes a seismic isolation device 31 disposed in a gap formed at a predetermined level (between the building body 10 and the foundation 20 in the present embodiment) so as to reduce input during an earthquake. It is configured.

  The seismic isolation device 31 is interposed between the column 11 (lower end beam 13) and the foundation slab 21 on the axis of the column 11 and the foundation pile 22.

  As shown in FIGS. 1 and 2, a seismic isolation device 31 is interposed on the axis of the column 11 located at the corners (protruding corners) C which are the four corners of the plane of the building body 10 (the foundation slab 21). However, an insulating space is provided between the lower end beam 13 and the foundation slab 21. That is, in the corner portion C, no force is exchanged between the building body 10 and the foundation 20. On the other hand, a seismic isolation device 31 is interposed between the pillar 11 other than the corner C where the insulating space is formed and the foundation slab 21.

  Although the structure of the seismic isolation device 31 is not limited, a laminated rubber bearing is employed in this embodiment. Further, in the present embodiment, the seismic isolation device 31 disposed at a position adjacent to the corner C has a seismic isolation device 31a provided with a laminated rubber bearing with a lead plug, a high damping rubber bearing, or an elastic sliding bearing. Is arranged. In addition, what is necessary is just to set the structure of the seismic isolation apparatus 31 located next to the corner C suitably according to the vertical load which the structure of the said seismic isolation apparatus bears, and with the seismic isolation apparatus arrange | positioned in another position It may be the same.

  The construction method of the base-isolated building of this embodiment is equipped with the 1st housing construction process, the seismic isolation layer formation process, the 2nd housing construction process, the support member removal process, and the 3rd housing construction process.

As shown in FIG. 3A, the first fence construction process is a process of constructing a chassis below the seismic isolation layer 30.
In this embodiment, the foundation 20 is constructed in the ground G as a frame below the seismic isolation layer 30. The housing below the seismic isolation layer 30 is not limited to the foundation 20 and may be, for example, an underground structure or a lower-floor housing.

  First, the ground is dug down and the foundation piles 22, 22,... Are formed at predetermined positions. Next, the foundation slab 21 is formed in a state where the heads of the foundation piles 22, 22,.

  In the seismic isolation layer forming step, temporary support members 32, 32,... Are arranged corresponding to the positions of the pillars 11 erected at the corner C of the plane of the building body 10, as shown in FIG. And it is the process of arrange | positioning the seismic isolation apparatus 31 corresponding to the position of the pillar 11 other than that.

  The seismic isolation device 31 is disposed on an extension line of the central axis of the foundation pile 22. In the present embodiment, a jack (not shown) is arranged around the temporary support member 32 together with the temporary support member 32.

  The temporary support member 32 supports the corner C of the building body 10 when the building body 10 is constructed. The configuration of the temporary support member 32 is not limited. For example, a shape steel may be provided.

  The second building construction step is a step of forming the building body 10 (housing) above the foundation 20 as shown in FIG. In other words, the frame (column 11, beam 12, lower end beam 13, etc.) on the floor above the seismic isolation layer 30 is constructed in a state where the column 11 is supported by the temporary support member 32 and the seismic isolation device 31.

The pillar 11 is formed on the axis of the seismic isolation device 31 and the temporary support member 32 (directly above), and the vertical load transmitted from each column 11 is supported by the seismic isolation device 31 and the temporary support member 32.
The beam 12 and the lower end beam 13 are formed so as to connect the adjacent columns 11 to each other.

The support member removal step is a step of removing the temporary support member 32 disposed in the corner C after the building body 10 (frame) is completely constructed to a predetermined position.
In addition, when the “building of the building body 10 is completed to a predetermined position”, for example, the vertical of the pillar 11 positioned at the corner C is obtained by completing the frame of the building body 10 to a predetermined height (level). This is when the load (axial force) can be transmitted to the seismic isolation device 31 arranged next to the corner C via the lower end beam 13 or the like.

  The temporary support member 32 is removed by extracting the temporary support member 32 in a state where the lower end beam 13 is lifted by a jack interposed between the lower end beam 13 and the foundation slab 21 in advance.

The third building construction process is a process of completing the seismic isolation building 1 by continuing the construction of the building body 10 (frame) with the insulating space formed at the corner C after the removal of the temporary support member 32 is completed. .
In addition, when the construction of the frame is completed at a stage where a predetermined axial force is applied to the seismic isolation device 31, such as a low-rise building, the third frame building process may be omitted.

  As described above, according to the base-isolated building 1 and the method for building a base-isolated building of the present embodiment, the cost reduction can be achieved by omitting the base-isolation device 31 for the corners C that are the four corners of the building body 10 having a small vertical load. Can be planned.

In addition, since the seismic isolation device 31 is omitted as an insulating space in the corner C of the building body 10 where lifting and sinking due to rocking vibration occurs, a large tensile axial force acts on the building body 10 and the foundation 20. Can be prevented. In other words, since an insulating space is formed in the corner C to allow rocking vibration (lifting and sinking), it is not necessary to construct a reinforcing structure or high-strength structure corresponding to the rocking vibration. Can be reduced.
Moreover, since it is not necessary to provide the seismic isolation device 31 corresponding to the rocking vibration, the cost can be reduced.

  Since the seismic isolation device 31 is interposed below each pillar 11 other than the corner C, the seismic isolation effect does not decrease.

  Since the vertical load at the corner C is transmitted to the foundation 20 via the seismic isolation device 31 below the column 11 located next to the column 11 located at the corner C, the stability of the seismic isolation building 1 is maintained. Has been. In addition, a large tensile force acts on the seismic isolation device 31 by omitting the seismic isolation device of the column 11 located at the corner C and increasing the axial force borne by the seismic isolation device 31 located next to the corner C. Can be prevented. Further, by increasing the axial force acting on the seismic isolation device 31 located next to the corner C, the lifting at the corner C can be suppressed.

  At the time of construction, since the vertical load of the corner C is temporarily received by the temporary support member 32, the stability at the time of construction is ensured. In addition, if the temporary support member 32 is removed after the building body 10 is completed or after the building body 10 is completed to a predetermined position, the seismic isolation building 1 that allows lifting and sinking due to rocking vibration is configured. Is done.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiment, and the above-described components can be appropriately changed without departing from the spirit of the present invention.

  For example, although the said embodiment demonstrated the seismic isolation building 1 whose planar view was a rectangular shape, the shape of the seismic isolation building 1 is not limited to the said shape. In other words, the base-isolated building is located between the pillars 11 and the foundations 20 at least at the four corners so as to allow lifting and sinking associated with rocking vibration according to the shape of the building. What is necessary is just to set it as the structure which abbreviate | omits the installed seismic isolation apparatus and provides insulation space.

As shown in FIG. 4 (a), the seismic isolation device 31 is omitted for the four corners C as in the case of the rectangular shape for the seismic isolation building 1a having a recess when viewed in plan ( An isolation space is provided), and the seismic isolation device 31 is disposed at other positions.
In addition, as shown in FIG. 4B, in the case of the base-isolated building 1b in which a part of the rectangle is cut out in plan view, in addition to the other corners C, C, C, the cut part The seismic isolation device 31 may be omitted (provided with an insulating space) for the two protruding corners (corners) C ′ and C ′ facing the surface, and lifting and sinking due to rocking vibration may be allowed. Note that the seismic isolation device 31 may be arranged at one of the two protruding corners C ′ and C ′ according to the planar shape of the building body 10.

DESCRIPTION OF SYMBOLS 1 Base isolation building 10 Building body 11 Column 12 Beam 13 Bottom beam 20 Foundation 21 Foundation beam 22 Foundation pile 30 Base isolation layer 31 Base isolation device 32 Temporary support member
C Corner

Claims (2)

A seismic isolation layer that reduces seismic input is provided at a predetermined level, and the building edge moves up and down during an earthquake and rocks and vibrates .
In the seismic isolation layer, the base is not provided with a seismic isolation device below at least four corners of the plane directly above the seismic isolation layer, and it is possible to allow the column to lift and sink. A seismically isolated building, characterized by a space and a seismic isolation device installed below the other pillars. Temporary support members are arranged corresponding to the positions of the pillars erected at at least four corners of the plane, and seismic isolation devices are arranged corresponding to the positions of the other pillars to form the seismic isolation layer. Process,
A step of constructing a frame above the seismic isolation layer in a state where a column is supported by the temporary support member and the seismic isolation device;
The temporary support member is removed after the construction of the frame has progressed to a predetermined height, and a seismic isolation device is not provided below the column erected at the corner , allowing the column to float or sink. And a step of providing an insulating space that is capable of providing a seismic isolation building.

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