JP6764642B2 - Seismic isolation structure and construction method of seismic isolation structure - Google Patents

Description

The present invention relates to a seismic isolation structure and a method of constructing a seismic isolation structure.

A seismic isolation structure including a pillar and a seismic isolation device installed on the stigma of the pillar is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-38420

By the way, when a seismic isolation device is installed on the stigma of a pillar, if the pillar is bent and deformed during an earthquake, the seismic isolation device may tilt and the performance of the seismic isolation device may deteriorate.

In consideration of the above facts, an object of the present invention is to suppress deterioration of the performance of the seismic isolation device.

The seismic isolation structure according to the first aspect includes a lower structure, a plurality of pillars erected on the lower structure, an upper structure supported by the plurality of pillars, and the lower structure provided on the pillars. A plurality of seismic isolation devices that allow the superstructure to be relatively displaced in the horizontal direction with respect to the body, and a plurality of beams that are joined to the adjacent columns and have a rectangular or L-shaped shape in a plan view. Be prepared.

According to the seismic isolation structure according to the first aspect , the upper structure is supported by the plurality of columns erected on the lower structure. In addition, each of the plurality of columns is provided with a seismic isolation device that allows the upper structure to be displaced in the horizontal direction with respect to the lower structure.

Here, a plurality of beams forming a rectangular shape or an L shape in a plan view are joined to the adjacent columns. As a result, the rigid frame frame is composed of adjacent columns and beams, so that the rigidity (flexural rigidity) of the columns is increased. Therefore, since the inclination of the seismic isolation device provided on the pillar is reduced, the deterioration of the performance of the seismic isolation device is suppressed.

Further, the plurality of beams have a rectangular shape or an L shape in a plan view. In this case, two beams extending in two horizontal directions are joined to a predetermined column located at a rectangular or L-shaped corner. For the columns located at this corner, the rigidity in two horizontal directions is increased. Therefore, the deterioration of the performance of the seismic isolation device is further suppressed.

The method of constructing the seismic isolation structure according to the second aspect includes a pillar construction step of providing a pair of columns in the ground, an excavation step of excavating the ground to expose the capitals of the pair of columns, and a pair of columns. It includes a beam erection step of erection of a beam on the stigma of the pillar and a seismic isolation device installation step of installing a seismic isolation device on each of the stigma of the pair of columns.

According to the method of constructing the seismic isolation structure according to the second aspect , first, in the column construction process, a pair of columns are provided in the ground. Next, in the excavation process, the ground is excavated to expose the capitals of the pair of columns. Next, in the beam erection process, the beam is erected on the capitals of the pair of columns. Then, in the seismic isolation device installation process, the seismic isolation device is installed on the capitals of the pair of columns.

As described above, in the present invention, since the seismic isolation device is installed on the stigma of the pair of columns after the beam is erected on the stigma of the pair of columns, the inclination of the pair of columns due to the installation of the seismic isolation device is caused. It will be reduced. Therefore, the installation work of the seismic isolation device becomes easy.

Further, by erection of a beam on the head of a pair of columns, the rigidity (bending rigidity) of the pair of columns can be enhanced. As a result, the deformation (bending deformation) of the pair of columns at the time of an earthquake is reduced. Therefore, since the inclination of the seismic isolation device provided on the stigma of the pair of columns is reduced, the deterioration of the performance of each seismic isolation device is suppressed.

As described above, according to the present invention, it is possible to suppress deterioration in the performance of the seismic isolation device.

It is a top view which shows the seismic isolation floor of the seismic isolation structure to which the seismic isolation structure which concerns on one Embodiment is applied. It is a cross-sectional view taken along the line 2-2 of FIG. It is a partially enlarged sectional view of FIG. It is a partially enlarged view of FIG. (A) to (C) are vertical cross-sectional views explaining the construction method of the seismic isolation structure according to one embodiment. (A) and (B) are vertical cross-sectional views explaining the construction method of the seismic isolation structure according to one embodiment. (A) and (B) are schematic views corresponding to FIG. 3 showing an inner pillar to which a modified example of the seismic isolation structure according to one embodiment is applied. It is a top view which corresponds to FIG.

Hereinafter, the seismic isolation structure and the construction method of the seismic isolation structure according to the embodiment of the present invention will be described with reference to the drawings. It should be noted that the arrow X direction and the arrow Y direction appropriately shown in each figure indicate two horizontal directions orthogonal to each other.

(Seismic isolation structure)
FIG. 1 shows the seismic isolation floor 12A of the seismic isolation structure 12 to which the seismic isolation structure 10 according to the present embodiment is applied. The seismic isolation structure 12 includes a foundation 20 as a substructure, a plurality of outer peripheral columns 16 and inner columns 30 erected on the foundation 20, and a plurality of exemptions provided on the plurality of outer peripheral columns 16 and inner columns 30. It includes seismic devices 19, 40 and a superstructure 50 (see FIG. 2) supported by a plurality of seismic isolation devices 19, 40.

The outer peripheral columns 16 are made of, for example, a reinforced concrete structure (RC structure), and are arranged along the outer periphery of the seismic isolation structure 12. Further, an RC outer wall 18 is provided between the adjacent outer peripheral columns 16. The outer wall 18 and the outer peripheral pillar 16 are integrated. As a result, the rigidity (flexural rigidity) of the outer peripheral column 16 is increased. Further, seismic isolation devices 19 are installed on the stigmas of the outer peripheral columns 16.

Inside the seismic isolation structure 12 (outer peripheral pillar 16), a plurality of inner pillars 30 as pillars are arranged in two horizontal directions (arrow X direction and arrow Y direction). The plurality of inner pillars 30 are CFTs (Concrete Filled Steel Tubes), as will be described later. Each inner column 30 has a smaller cross-sectional area than the outer peripheral column 16, and has a lower rigidity (flexural rigidity) than the outer peripheral column 16. The seismic isolation structure 10 according to the present embodiment is applied to the inner pillar 30 having such low rigidity.

That is, beams 70 are erected on each of the four inner columns 30 arranged in two horizontal directions. These beams 70 have a rectangular shape (square shape) in a plan view. In other words, the four beams 70 form a rectangular flat frame 90 in a plan view. In the present embodiment, the two flat frames 90 are discontinuously provided in an island shape. Hereinafter, the seismic isolation structure 10 according to the present embodiment will be specifically described.

(Substructure)
As shown in FIG. 2, the foundation 20 as a substructure is a pile foundation. The foundation 20 has a plurality of concrete piles 22 buried in the ground G and a reinforced concrete foundation slab 24 provided on the ground G and supported by the plurality of concrete piles 22.

The concrete pile 22 is a cast-in-place concrete pile. The foundation slab 24 is supported by the pile head 22U of the concrete pile 22. The foundation slab 24 forms the floor of the seismic isolation floor 12A of the seismic isolation structure 12. In the present embodiment, the foundation slab 24 forms the floor of the parking lot.

The lower part 26L of the structural pillar 26 is buried in the concrete pile 22. The upper portion 26U of the structure Shinbashira 26 is raised upward from the pile head 22U of the concrete pile 22, and penetrates the foundation slab 24 in the vertical direction. Further, the upper portion 26U of the structural pillar 26 is raised upward from the upper surface of the foundation slab 24. The upper 26U of the structure Shinbashira 26 constitutes the inner pillar 30 of the seismic isolation floor 12A.

A beam 70, which will be described later, is joined to the stigma 30U of the inner column 30. Further, a seismic isolation device 40 is provided on the pillar head 30U of the inner pillar 30. That is, in this embodiment, the stigma seismic isolation structure is adopted. The seismic isolation device 40 is, for example, a laminated rubber bearing. A superstructure 50 is constructed on the seismic isolation device 40. The superstructure 50 is supported by the outer peripheral columns 16 and the inner columns 30 via the seismic isolation devices 19 and 40 (see FIG. 1). The plurality of seismic isolation devices 19 and 40 allow the upper structure 50 to be displaced relative to the foundation 20 as the lower structure in the horizontal direction.

(Superstructure)
The superstructure 50 has a plurality of inner columns 52 erected on each seismic isolation device 40, and a beam 64 erected between the column bases 52L of the adjacent inner columns 52. The column base 52L of the inner column 52 is a column-beam joint, and the ends of the beams 64 are joined to each other. The beam 64 is made of, for example, H-shaped steel. A slab 66 is provided on the beam 64.

(Seismic isolation device)
As shown in FIG. 3, the seismic isolation device 40 is installed on the stigma 30U of the inner pillar 30. The inner pillar 30 (construction pillar 26) is made of, for example, a CFT structure, and has a steel pipe pillar 32 and a concrete 34 filled in the steel pipe pillar 32. The stigma 30U of the inner pillar 30 is formed in a trapezoidal shape whose width increases toward the top. A pair of diaphragms 36 are provided on the stigma 30U.

The pair of diaphragms 36 are, for example, through diaphragms, and are arranged so as to face each other in the vertical direction. Each diaphragm 36 is formed with a through hole 38 for filling concrete 34. Further, on the upper surface of the upper diaphragm 36, a lower base plate 44 is provided via a plurality of adjusting ribs 42 for height adjustment. The lower flange portion 40L of the seismic isolation device 40 is joined to the lower base plate 44 by bolts and nuts (not shown). A concrete 46 for fireproof coating is cast around the adjusting rib 42.

The inner column 52 of the upper structure 50 has a CFT structure, and has a steel pipe column 54 and concrete 56 filled in the steel pipe column 54. The column base 52L of the inner column 52 is formed in a trapezoidal shape whose width increases toward the bottom. A pair of diaphragms 58 are provided on the column base portion 52L.

The pair of diaphragms 58 are, for example, through diaphragms, and are arranged so as to face each other in the vertical direction. Each diaphragm 58 is formed with a through hole 59 for filling the concrete 56. Further, on the lower surface of the lower diaphragm 58, an upper base plate 61 is provided via a plurality of adjusting ribs 60 for height adjustment. The upper flange portion 40U of the seismic isolation device 40 is joined to the upper base plate 61 by bolts and nuts (not shown). Around the adjusting rib 60, concrete 62 for fireproof coating is cast.

(Beam)
As shown in FIG. 2, a beam 70 is erected on the stigma 30U of a pair of adjacent inner columns 30. The beam 70 is made of, for example, H-shaped steel. The beam 70 has an upper and lower flange portions 70A and a web portion 70B that connects the upper and lower flange portions 70A. Further, the ends of the beam 70 on both sides in the material axis direction are joined (rigidly joined) to the side surface of the column head 30U of the inner column 30 by welding or the like. As a result, the rigid frame frame 72 is composed of a pair of adjacent inner columns 30 and beams 70. The method of joining the inner pillar 30 and the beam 70 can be changed as appropriate.

Further, a vibration damping device 80 such as an oil damper is installed on the beam 70. That is, the beam 70 also functions as a stand for installing the vibration damping device 80. The vibration damping device 80 is connected to the beam 70 and the beam 64 of the superstructure 50, and operates with the operation (shear deformation) of the seismic isolation device 40 to absorb vibration energy. The vibration damping device 80 can be omitted as appropriate. Further, various facilities such as pipes, wirings, and ducts can be installed on the beam 70.

As shown in FIG. 4, four beams 70 having a rectangular shape in a plan view are erected on each of the four inner columns 30 arranged in two horizontal directions. Specifically, a beam 70 is erected on the stigma 30U of a pair of inner columns 30 adjacent to each other in the direction of arrow X. As a result, two rigid frame frames 72 are formed in the direction of arrow X. Similarly, a beam 70 is erected on the stigma 30U of the pair of inner columns 30 adjacent to each other in the Y direction of the arrow. As a result, two rigid frame frames 72 are formed in the Y direction of the arrow. As a result, the rigidity of the four inner columns 30 in the two horizontal directions (arrow X direction and arrow Y direction) is increased.

Next, an example of the construction method of the seismic isolation structure according to the present embodiment will be described.

In the present embodiment, the seismic isolation structure 12 is constructed by the so-called reverse striking method. Specifically, first, as shown in FIG. 5 (A), in the column construction process, a plurality of vertical holes for the concrete pile 22 are formed in the ground G, and concrete is poured into these vertical holes. The concrete pile 22 is formed. A mountain retaining wall (not shown) is constructed on the ground G along the outer circumference of the seismic isolation structure 12 (see FIG. 1).

Next, the lower 26L of the steel pipe column 32 constituting the structural pillar 26 is inserted into the concrete pile 22 before hardening. At this time, the lower portion 26L of the structure pillar 26 is inserted into the concrete pile 22 so that the stigma of the structure pillar 26 reaches a depth corresponding to the installation position (installation height) of the seismic isolation device 40. Further, after inserting the structural pillar 26 into the concrete pile 22, the vertical holes are appropriately backfilled.

Next, as shown in FIG. 5B, in the excavation process (primary excavation process), the ground G is excavated, and the stigmas of the adjacent structural pillars 26, that is, the stigmas 30U of the adjacent inner pillars 30 are excavated. Expose. Next, the steel pipe column 32 constituting the structural column 26 is filled with concrete 34 (see FIG. 3) to form the structural column 26 made of CFT. The inner pillar 30 of the seismic isolation floor 12A is formed by the upper 26U of the structure Shinbashira 26.

Next, as shown in FIG. 5C, in the beam erection step, the beam 70 is erected on the stigma 30U of the pair of inner columns 30 adjacent to each other in the arrow X direction. At this time, as shown in FIG. 4, the beam 70 is also erected on the stigma 30U of the pair of inner columns 30 adjacent to each other in the Y direction of the arrow.

Next, as shown in FIG. 3, the lower base plate 44 is joined to the upper surface of the stigma 30U of the inner column 30 via a plurality of adjusting ribs 42. At this time, the height of the lower base plate 44 is adjusted by the adjusting rib 42.

Next, as shown in FIG. 6A, in the seismic isolation device installation process, the seismic isolation device is released on the lower base plate 44 (see FIG. 3) provided on the stigma 30U of the pair of adjacent inner columns 30. The seismic isolation device 40 is installed, and the lower flange portion 40L of the seismic isolation device 40 and the lower base plate 44 are joined by bolts or the like (not shown).

Next, in the superstructure construction process, the inner columns 52 and beams 64 of the superstructure 50 are installed on the seismic isolation device 40. Further, as shown in FIG. 3, the upper base plate 61 is joined to the lower surface of the column base portion 52L of the inner column 52 via the adjusting rib 60, and the upper base plate 61 and the upper flange portion 40A of the seismic isolation device 40 are joined. Is joined with bolts (not shown). At this time, the position of the upper base plate 61 is appropriately adjusted by the adjusting rib 60.

Next, as shown in FIG. 6B, an excavation step (secondary excavation step) is performed after the superstructure construction step or in parallel with the superstructure construction step. In this excavation process, the ground G is excavated until the pile head 22U of the concrete pile 22 is reached, and concrete is poured into the excavation bottom to construct the foundation slab 24. As a result, the seismic isolation floor 12A is formed.

As described above, in the present embodiment, after the beam 70 is erected on the stigma 30U of the pair of adjacent inner columns 30, the seismic isolation device 40 is installed on the stigma 30U of the inner column 30. Therefore, the inclination of the pair of inner columns 30 due to the installation of the seismic isolation device 40 is reduced. Therefore, the installation work of the seismic isolation device 40 becomes easy.

Further, only the stigma 30U of the pair of adjacent inner columns 30 is exposed from the ground G, the beam 70 is erected on the stigma 30U, and the seismic isolation device 40 is installed on the stigma 30U. As a result, the beam 70 and the seismic isolation device 40 can be constructed using the ground surface of the ground G as a scaffold. Therefore, the workability of the beam 70 and the seismic isolation device 40 is improved.

Further, in the excavation process (secondary excavation fixing), the ground G is excavated with the beam 70 erected on the capital 30U of the pair of inner columns 30. As a result, the inclination of the pair of inner pillars 30 (construction pillars 26) due to excavation is suppressed.

Next, the operation and effect of this embodiment will be described.

According to the present embodiment, as shown in FIG. 2, the stigma 30U of the inner column 30 raised from the foundation slab 24 is joined to the inner column 52 of the superstructure 50 via the seismic isolation device 40. ing. That is, in this embodiment, the stigma seismic isolation structure is adopted. As a result, the floor height of the seismic isolation floor 12A can be increased, so that the seismic isolation floor 12A can be effectively used.

On the other hand, when the stigma 30U of the inner column 30 is joined to the inner column 52 of the upper structure 50 via the seismic isolation device 40, the degree of fixation of the stigma 30U is lowered, and the inner column 30 is in a cantilevered state. It will be supported by the basic slab 24. Therefore, the amount of bending deformation of the inner column 30 tends to increase during an earthquake. If the amount of bending deformation of the inner pillar 30 becomes large, the seismic isolation device 40 may tilt and the performance of the seismic isolation device 40 may deteriorate.

On the other hand, in the present embodiment, the beam 70 is erected on the stigma 30U of the pair of adjacent inner columns 30. As a result, the rigid frame frame 72 is formed by the pair of adjacent inner columns 30 and the beams 70, so that the rigidity (flexural rigidity) of the pair of inner columns 30 is increased. Therefore, since the inclination of the seismic isolation device 40 provided on the pair of inner columns 30 is reduced, the deterioration of the performance of the seismic isolation device 40 is suppressed.

Further, as shown in FIG. 4, four beams 70 having a rectangular shape in a plan view are erected on the four inner columns 30 arranged in two horizontal directions (arrow X direction and arrow Y direction). ing. Specifically, a beam 70 is erected on the stigma 30U of a pair of inner columns 30 adjacent to each other in the direction of arrow X. As a result, two rigid frame frames 72 are formed in the direction of arrow X. Similarly, a beam 70 is erected on the stigma 30U of the pair of inner columns 30 adjacent to each other in the Y direction of the arrow. As a result, two rigid frame frames 72 are formed in the Y direction of the arrow.

Therefore, in the present embodiment, the rigidity of the four inner columns 30 in the two horizontal directions (arrow X direction and arrow Y direction) is increased. Therefore, the deterioration of the performance of the seismic isolation device 40 installed at the stigma 30U of the four inner pillars 30 is further suppressed.

By the way, on the seismic isolation floor 12A, the ceiling height is partially lowered in the portion where the beam 70 is installed. On the other hand, in the present embodiment, as shown in FIG. 1, two plane frames 90 having a rectangular shape in a plan view are arranged in an island shape without being continuous. As a result, for example, while the space under each flat frame 90 is used as a parking space for an ordinary automobile or the like, a passage such as a large bus can be formed between the two flat frames 90. Therefore, the seismic isolation floor 12A can be effectively used. Further, the two flat frames 90 can be used, for example, as the core portion of the seismic isolation structure 12.

Further, as shown in FIG. 2, a vibration damping device 80 or the like can be installed on the beam 70 erected on the stigma 30U of the pair of inner columns 30. Therefore, it is not necessary to install a frame for the vibration damping device 80 separately from the beam 70, so that the cost can be reduced.

Next, a modified example of the above embodiment will be described.

In the above embodiment, the seismic isolation device 40 is installed at the stigma 30U of the inner pillar 30, but the above embodiment is not limited to this. For example, as shown in FIG. 7A, the seismic isolation device 40 may be installed between the column base 30L of the inner column 30 and the foundation slab 24. In this case, the bending rigidity of the inner columns 30 can be efficiently increased by installing the beams 70 between the column bases 30L of the pair of adjacent inner columns 30.

Further, for example, as shown in FIG. 7B, the inner pillar 30 is divided into a lower inner pillar 91 and an upper inner pillar 92, and between the lower inner pillar 91 and the upper inner pillar 92. A seismic isolation device 40 may be installed. In this case, the rigidity of the lower inner column 91 can be efficiently increased by installing the beam 70U on the stigma 91U of the pair of adjacent lower inner columns 91. Further, by erection of the beam 70L on the column base portion 30L of the pair of adjacent upper inner columns 92, the rigidity of the upper inner column 92 can be efficiently increased. Either one of the beam 70U and the beam 70L may be omitted.

Further, in the above-described embodiment, a plurality of beams 70 having a rectangular shape in a plan view are erected on a plurality of inner columns 30 arranged in two horizontal directions, but the above-described embodiment is not limited to this. For example, as shown in FIG. 8, a plurality of (two) beams 70 having an L-shape in a plan view may be erected on the plurality of inner columns 30 arranged in two horizontal directions. In this case, the rigidity of the inner column 30 to which the beam 70 is joined is increased. Therefore, deterioration of the performance of the seismic isolation device 40 provided on the inner pillar 30 is suppressed.

Further, for the inner pillar 30 located at the L-shaped corner portion C, a beam 70 extending in two horizontal directions is joined. Therefore, the rigidity of the inner pillar 30 of the corner portion C is increased in two horizontal directions (arrow X direction and arrow Y direction). Therefore, the deterioration of the performance of the seismic isolation device 40 installed on the inner pillar 30 of the corner portion C is further suppressed.

Further, for example, a stiffening member such as a horizontal brace or a floor (slab) is provided between a plurality of beams 70 having a rectangular or L-shaped shape in a plan view to increase the rigidity of the inner column 30 to which the beams 70 are joined. It is possible to further increase it.

Further, in the above embodiment, the beams 70 are erected between the pair of inner columns 30 on the seismic isolation floor 12A. For example, the beams 70 may be erected between the inner columns 30 and the outer peripheral columns 16, or a pair. A beam 70 may be erected between the outer peripheral columns 16.

Further, in the above embodiment, the inner column 30 is made of CFT structure, but the inner column 30 may be made of steel frame, RC structure, SRC structure or the like. Similarly, in the above embodiment, the beam 70 is made of steel, but the beam 70 may be made of RC, SRC, or the like.

Further, in the above embodiment, the seismic isolation device 40 is a laminated rubber bearing, but the seismic isolation device may be, for example, a sliding bearing or a rolling bearing.

Further, in the above embodiment, the seismic isolation structure 12 is an underground foundation seismic isolation, but the above embodiment is not limited to this. The seismic isolation structure 10 according to the above embodiment can also be applied to the intermediate floor (intermediate floor seismic isolation) of the seismic isolation structure 12.

Further, in the above embodiment, the seismic isolation structure 12 is constructed by the so-called reverse striking method, but the seismic isolation structure 12 may be formed by another construction method.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and one embodiment and various modifications may be used in combination as appropriate. Of course, it can be carried out in various modes as long as it does not deviate.

10 Seismic isolation structure 12 Seismic isolation structure 20 Foundation (substructure)
30 Inner pillar (pillar)
30U Capital 40 Seismic isolation device 50 Superstructure 70 Beam 70U Beam 70L Beam

Claims (2)

Substructure and
A plurality of inner columns that are erected on the substructure and arranged inside the outer column ,
An upper structure supported by the plurality of inner columns and
A plurality of seismic isolation devices provided on the inner pillar and allowing the upper structure to be displaced relative to the lower structure in the horizontal direction.
A flat frame that is formed into a rectangular or L-shape in a plan view by a plurality of beams erected on the adjacent inner columns , and is not continuous.
Seismic isolation structure with. A pillar construction process in which multiple inner pillars arranged inside the outer pillars are provided in the ground,
An excavation process in which the ground is excavated to expose the capitals of the plurality of inner columns , respectively.
A beam erection process in which beams are erected on the stigmas of a plurality of the inner columns to form a rectangular or L-shaped and non-continuous planar frame in a plan view.
The seismic isolation device installation process of installing seismic isolation devices on the capitals of the plurality of inner columns , and
Construction method of seismic isolation structure equipped with.

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