JP2022178700A - Base-isolation device installation structure - Google Patents

Abstract

To provide base isolation device installation structure capable of shortening a construction period, installing a base isolation device in an early stage, and erecting a steel frame of an upper part of the base isolation device without waiting for bar arrangement of a lower part or placement of concrete.SOLUTION: Base isolation device installation structure 10 has a steel reinforced concrete column 16, a steel pipe joint member 18 joined to the upper part of a steel frame material 26 of the column 16 and filled with concrete 58, and a base isolation device 60 installed on a base plate 38 provided on an upper part of the steel pipe joint member 18.SELECTED DRAWING: Figure 1

Description

The present invention relates to a seismic isolation device installation structure.

A seismic isolation device installation structure for a building is known (see, for example, Patent Document 1).

JP 2016-153571 A

In the case of steel-framed intermediate-story seismic isolation, the columns supporting the seismic isolation device are often CFTs (Concrete Filled Steel Tubes).
By the way, if this seismic isolation device includes a sliding bearing, a sliding plate with a large area is required to slide the bearing, and the connection on the side that receives the bearing becomes large. Correspondingly, the cross-section of the columns that support the seismic isolation device at the bottom becomes larger, and the steel pipes of the columns become large cross-section build boxes (welded four-sided boxes made by welding four thick plates), resulting in cost. have a large impact. Therefore, it was difficult to adopt sliding bearings for intermediate layer seismic isolation using CFT for the columns that support the seismic isolation device.

Therefore, it is conceivable to use SRC (Steel Reinforced Concrete Construction) for the pillars that support the seismic isolation device. However, if the column is made of SRC, after erecting the steel frame, the reinforcement arrangement, formwork installation, concrete pouring, and formwork removal are performed in order. There is a problem that the construction period will be long because the steel frame of the upper part will be erected.

In consideration of the above facts, the present invention can shorten the construction period, and install the seismic isolation device early to construct the upper steel frame of the seismic isolation device, and the lower reinforcement and concrete placement. To provide a seismic isolation device installation structure that can be installed without waiting.

The seismic isolation device installation structure according to claim 1 includes a steel-framed reinforced concrete column, a steel pipe connection member joined to the upper part of the steel frame of the column and filled with concrete, and an upper part of the steel pipe connection member. a seismic isolation device installed on a base plate provided in a connecting reinforcing bar having an upper portion embedded in the concrete of the steel pipe connection member and a lower portion protruding from the lower surface of the steel pipe connection member; The column main reinforcement of the column is connected.

In the seismic isolation device installation structure according to claim 1, the steel pipe connection member for installing the seismic isolation device is of so-called CFT construction, and the pillar supporting the steel pipe connection member is of steel reinforced concrete construction.

For this reason, in the seismic isolation device installation structure of claim 1, a steel pipe connection member is joined to the upper part of the steel frame that is a part of the structural element of the steel-framed reinforced concrete column, and concrete is placed inside the steel pipe connection member. is filled and hardened, the seismic isolation device can be installed on the base plate provided on the upper part of the steel pipe connection member.

Therefore, the erection of the steel frame for the upper part of the seismic isolation device, the reinforcing work of the steel-framed reinforced concrete columns, and the work of placing the formwork concrete can be carried out in parallel, so that the construction period can be shortened.

In addition, by connecting the connecting rebar protruding from the lower surface of the steel pipe connection member and the column main reinforcement, even if the structures of the two are different, such as the steel pipe connection member is CFT and the column is SRC, Axial force can be reliably transmitted to the column.

The invention according to claim 2 is the seismic isolation device installation structure according to claim 1, wherein the seismic isolation device includes laminated rubber and a slide bearing provided between the laminated rubber and the base plate. consists of

In the seismic isolation device installation structure according to claim 2, the laminated rubber functions under a small seismic force, and the laminated rubber slides due to a sliding bearing under a large seismic force, thereby reducing shaking of the building.

The invention according to claim 3 is the seismic isolation device installation structure according to claim 2, wherein the cross-sectional area of the upper part of the steel pipe connection member to which the base plate is attached is joined to the steel frame material of the column. It is made larger than the cross-sectional area of the lower part.

According to the invention of claim 3, in the seismic isolation device installation structure of claim 2, there is no need to increase the cross-sectional area of the pillar in accordance with the amount of slippage of the laminated rubber, that is, to eliminate the need to thicken the pillar. You can make the columns thinner.

As described above, according to the seismic isolation device installation structure of the present invention, the construction period can be shortened, and the seismic isolation device can be installed at an early stage so that the erection of the upper steel frame of the seismic isolation device can be changed to the lower one. It has an excellent effect that it can be performed without waiting for placing bars and concrete.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an elevational view showing a main part of a base isolation building to which a base isolation device installation structure according to one embodiment of the present invention is applied; (A) is a plan view showing the base plate of the steel pipe connection member, (B) is a plan view showing the partition plate of the steel pipe connection member, and (C) is a plan view showing the bottom plate of the steel pipe connection member. be. It is a sectional view showing a seismic isolation device. FIG. 4 is an elevation view showing a steel frame with a box joined to the top; Fig. 2 is an elevational view of a box with connecting rebars attached; 1 is a sectional view showing a box filled with concrete; FIG. 1 is a cross-sectional view showing a box filled with concrete and grout; FIG. It is an elevation view showing a box equipped with a seismic isolation device. It is an elevation view which shows the foundation which performed reinforcement arrangement and concrete placement, and the steel frame which performed reinforcement arrangement. It is an elevation view which shows the state which filled the concrete in the formwork. FIG. 4 is an elevational view showing a formwork in which a space is filled with a grout agent;

A seismic isolation structure 12 to which a seismic isolation device installation structure 10 according to an embodiment of the present invention is applied will be described with reference to FIGS. 1 to 11. FIG.
FIG. 1 shows the first basement floor of a base isolation structure 12 to which a base isolation device installation structure 10 according to this embodiment is applied.
The seismic isolation structure 12 includes a reinforced concrete foundation beam 14 and a plurality of SRC columns 16 erected on the foundation beam 14 . The seismic isolation structure of this embodiment is a so-called middle-story seismic isolation building in which a seismic isolation device 60 is provided on the intermediate floor of the building.

A steel pipe connection member 18 made of CFT is provided on the top of the column 16 . A beam 20 is attached to the side portion of the steel pipe connection member 18, and a seismic isolation device 60, which will be described later, is installed on the upper portion of the steel pipe connection member 18. As shown in FIG.

A concrete pile 22 is buried in the ground G directly below the pillar 16 .

(Pillar structure)
The column 16 has a steel frame 26 , a column main reinforcing bar 28 , and a tie bar 30 embedded in concrete 24 . Cross H steel is used as an example of the steel frame material 26 of the present embodiment, but other steel frame material can also be used.

(Steel pipe joint material)
The steel pipe connection member 18 includes a steel box 32 having an inverted trapezoidal shape when viewed from the side and configured so that the horizontal cross-sectional area decreases downward.
The box 32 has a tubular portion formed by four lower plates 34 and four upper plates 36, and an upper opening of the tubular portion is closed with a base plate 38 as an upper portion of the steel pipe joint member 18. The lower side of the tubular portion is closed with a bottom plate 40 as the lower portion of the steel pipe joint member 18 .

The tubular portion is formed so that the axial direction is the vertical direction, and a partition plate 42 is provided in the vertical middle portion. The lower plate 34, upper plate 36, base plate 38, bottom plate 40, and partition plate 42 are all made of steel.

As shown in FIG. 2(A), the base plate 38 is formed in a rectangular shape in a plan view, with a circular concrete placing hole 44 formed in the center and a rectangular concrete placing hole 44 surrounding the concrete placing hole 44 . Four concrete placement holes 46 are formed.

This base plate 38 is formed larger than the bottom plate 40 . The size of the base plate 38 is determined according to the size of the sliding plate 70 of the seismic isolation device 60 described later, and the size of the bottom plate 40 is determined according to the thickness of the column 16 .

As shown in FIG. 2B, the partition plate 42 is formed in a rectangular shape, and as shown in FIG. A similar concrete placement hole 48 is formed.

As shown in FIGS. 1 and 2C, the bottom plate 40 has a plurality of (four in this embodiment) connecting reinforcing bar through-holes 50 directly below the concrete placing holes 48 of the partition plate 42. ing. The connecting reinforcing bar through hole 50 is penetrated by the connecting reinforcing bar 52 inserted from the concrete placing hole 46 and the concrete placing hole 48 . The connecting reinforcing bar through hole 50 is formed to have a slightly larger diameter than the connecting reinforcing bar 52 .

The connecting reinforcing bar 52 penetrates the connecting reinforcing bar through-hole 50 in the vertical direction, and the upper portion thereof is arranged inside the box 32 and formed in the shape of an upper hook.

The lower ends of connecting reinforcing bars 52 protruding downward from the bottom plate 40 are joined to the upper ends of the column main reinforcing bars 28 of the columns 16 using mechanical joints 54 .

The inside of the box 32 is filled with concrete 58 and grouting agent 76 without gaps.

(Seismic isolation device)
A seismic isolation device 60 is mounted on the base plate 38 of the box 32 .
As shown in FIG. 3, the seismic isolation device 60 of the present embodiment includes a sliding bearing 62 and a columnar laminated rubber 64, and the laminated rubber 64 and the sliding bearing 62 are arranged vertically in series. It is configured as The laminated rubber 64 is formed by alternately laminating thin reinforcing steel plates 64A and rubber layers 64B.

A disk-shaped steel flange 66 is provided at the upper end of the laminated rubber 64 , and the flange 66 is fixed to an upper structure 68 provided on the upper side of the laminated rubber 64 . The shape of the laminated rubber 64 may be a shape other than a cylindrical shape, for example, a prismatic shape.

The slide bearing 62 includes a slide plate 70 provided on the steel pipe joint member side and a disk-shaped slide member 72 provided on the rubber body side. As an example, the planar shape of the slide plate 70 is square.

The slide plate 70 is fixed to the upper surface of the base plate 38 of the steel pipe joint member 18 . Further, the sliding member 72 is fixed to the thick reinforcing steel plate 64C of the laminated rubber 64 and is in contact with the sliding plate 70 so as to be slidable. The planar shape of the sliding plate 70 and the sliding member 72 may be other shapes.

(upper structure)
An upper structure 68 is supported above the laminated rubber 64 . The upper structure 68 is, for example, a building having a plurality of inner pillars (not shown) built on the seismic isolation device 60 and beams (not shown) installed between the column bases of adjacent inner pillars. be. The column base of the inner column is a column-to-beam joint, and the end of the beam is joined.

(Construction procedure)
Next, the construction procedure of the seismic isolation structure 12 of this embodiment will be described.

(1) Construction of Steel Frames for Columns As shown in FIG. After that, the box 32 is attached to the top of the steel frame 26 and the beam 20 is attached to the side of the box 32 . In addition, in FIG. 4 and other drawings, illustration of reinforcing bars inside the concrete 78 is omitted.

(2) Installation of connecting reinforcing bars Next, as shown in FIG. The lower end protrudes downward from the bottom plate 40 . Incidentally, the connection reinforcing bar 52 is temporarily held in the box 32 using a jig (not shown).

(3) Concrete Placement As shown in FIG. 6, concrete 58 is placed inside the box 32 through the concrete placement hole 44 or the concrete placement hole 46 of the box 32 . In the present embodiment, the concrete 58 is placed so that a gap-like space S1 is formed between the upper surface of the concrete 58 and the lower surface of the base plate 38 . In order to prevent the concrete 58 from leaking from the gap between the connecting reinforcing bar through-hole 50 and the connecting reinforcing bar 52, it is preferable to fill the gap with a filler or the like in advance.

(4) Filling with grouting agent After the concrete 58 hardens, as shown in FIG. 7, a non-shrinking grouting agent 76 is filled so as to fill the space S1 formed between the upper surface of the concrete 58 and the lower surface of the base plate 38. , and the grout agent 76 is brought into contact with the lower surface of the base plate 38 . When the grout agent 76 is hardened, the CFT steel pipe connection member 18 is completed.

(5) Installation of seismic isolation device After the grouting agent 76 hardens, the seismic isolation device 60 is mounted on the base plate 38 and the sliding plate 70 is fixed to the base plate 38 as shown in FIG. The upper surface of the base plate 38 may be ground with a grinder.
After the seismic isolation device 60 is installed, the steel frame of the upper structure 68 can be erected on the seismic isolation device 60 .

(6) Connection of column main reinforcing bars and connecting reinforcing bars, foundation beam reinforcement arrangement, basement column reinforcement arrangement, concrete placement of foundation beams. The column main reinforcement 28 is arranged on the upper end portion of the column main reinforcement 28 and the lower end portion of the connection rebar 52 of the steel pipe joint member 18 is connected by a mechanical joint 54 . Thereafter, the reinforcing bars 30 are arranged around the steel frame 26, the reinforcing bars 14A of the foundation beam 14 are arranged on the concrete 78, and the concrete 14B is placed.

(7) Pour Concrete for Columns After the concrete 14B of the foundation beam 14 has hardened, as shown in FIG. Concrete 24 is pressed into the frame. In this embodiment, the concrete 24 is press-fitted so that a gap-like space S2 is formed between the concrete 24 and the bottom plate 40 of the steel pipe joint member 18 .

(8) Grout Filling After the concrete 24 hardens, a non-shrink grout 82 is filled in the space S2 formed between the upper surface of the concrete 24 and the lower surface of the bottom plate 40 as shown in FIG. , the grouting agent 82 is brought into contact with the lower surface of the bottom plate 40 . As an example, the grouting agent 82 is filled through a filling hole (not shown) formed in the side surface of the mold 80 .

(9) Removal of Column Formwork After the grout agent 82 has hardened, the formwork 80 is removed to complete the SRC column 16 (see FIG. 1).

(effect)
The seismic isolation structure 12 of this embodiment is characterized in that the steel pipe joint member 18 is made of CFT construction, and the column 16 is made of SRC construction. Therefore, a box 32 is joined to the upper part of the steel frame 26 before completion of the column 16, concrete 58 is placed inside the box 32, and a grouting agent 76 is filled and hardened, and then a seismic isolation device 60 is installed. can. Therefore, the seismic isolation device 60 can be installed early, and the steel frame of the upper part of the seismic isolation device 60 can be erected without waiting for the reinforcement arrangement of the lower column 16 and the placing of concrete. In addition, the erection of the steel frame for the upper part of the seismic isolation device 60 and the reinforcing work for the steel-framed reinforced concrete column 16 and the formwork concrete placing work can be carried out in parallel, thereby shortening the construction period.

CFT construction is easier to work on site than SRC construction, which requires reinforcement arrangement, formwork installation, concrete filling, and formwork removal.

In the seismic isolation structure 12 of this embodiment, the cross-sectional area of the column 16 is not determined according to the size of the sliding plate 70 of the bearing-equipped seismic isolation device 60, so the cross-sectional area of the column 16 needs to be increased more than necessary. and the cost impact can be reduced.

In other words, the column 16 only needs to have a minimum necessary cross-sectional area (thickness) that can support the load on the top. can be made thin.

Furthermore, in the seismic isolation device installation structure 10 of the present embodiment, the connecting reinforcing bars 52 protruding from the lower surface of the steel pipe connection members 18 are connected to the column main bars 28 of the columns 16, so that the steel pipe connection members 18 are made of CFT. Even if the structures of both are different, for example, the column 16 is made of SRC, the axial force can be reliably transmitted from the steel pipe connection member 18 to the column 16 .

[Other embodiments]
An embodiment of the present invention has been described above, but the present invention is not limited to the above, and can of course be implemented in various modifications without departing from the gist of the present invention. is.

In the above embodiment, the column main reinforcement 28 and the connection reinforcement 52 are connected by the mechanical joint 54, but the present invention is not limited to this, and the column main reinforcement 28 and the connection reinforcement 52 may be joined by welding.

Although the seismic isolation device 60 of the present embodiment includes the slide bearing 62 and the laminated rubber 64, the present invention is not limited to this, and the seismic isolation device 60 may be of other types. good.

In the above embodiment, the concrete 24 is press-fitted into the formwork 80 so as to form a gap-like space S2 between the steel pipe joint member 18 and the bottom plate 40, and then the space S2 is filled with the grouting agent 82. However, the concrete 24 may be pressed into the mold 80 so that the space S2 is not formed.

In the above embodiment, the concrete 58 is poured into the box 32 so as to form the gap-like space S1 between the base plate 38 of the steel pipe connection member 18 and the space S1, and then the space S1 is filled with the grouting agent 76. Concrete 58 may be poured into the box 32 so that the space S1 is not formed.

10 Base isolation device installation structure 16 Column 18 Steel pipe connection member 26 Steel frame 28 Column main reinforcement 38 Base plate 52 Connecting reinforcing bar 54 Mechanical joint 58 Steel pipe connection member concrete 60 Seismic isolation device 62 Slide bearing 64 Laminated rubber

Claims (3)

steel reinforced concrete pillars,
a steel pipe connection member joined to the upper part of the steel frame of the column and filled with concrete;
a seismic isolation device installed on a base plate provided on the upper part of the steel pipe connection member;
with
A connection reinforcing bar having an upper portion embedded in the concrete of the steel pipe connection member and a lower portion protruding from the lower surface of the steel pipe connection member, and the connection reinforcing bar and the column main reinforcing bar of the column are connected.
Seismic isolation device installation structure. The seismic isolation device includes a laminated rubber and a slide bearing provided between the laminated rubber and the base plate.
The seismic isolation device installation structure according to claim 1. In the steel pipe connection member, the cross-sectional area of the upper portion to which the base plate is attached is larger than the cross-sectional area of the lower portion that is joined to the steel frame material of the column.
The seismic isolation device installation structure according to claim 2.

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