Base isolation device installation structure

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

Technical Field

[0001] The present invention relates to a seismic isolation device installation structure.

Background Art

[0002] A seismic isolation device installation structure for a building is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of intermediate floor seismic isolation of a steel frame structure, the columns supporting the seismic isolation device are often made of CFT (Concrete Filled Steel Tube). By the way, if this seismic isolation device includes a sliding bearing, a large-area sliding plate is required to slide the bearing, and the opening on the side receiving the bearing becomes large. Accordingly, the column cross-section of the column supporting the seismic isolation device below also becomes large, and the steel pipe of the column becomes a large-section build box (a welded four-sided box made by welding four thick plates), etc., and the influence on the cost is great. Therefore, in the intermediate floor seismic isolation where the columns supporting the seismic isolation device are made of CFT, it has been difficult to adopt a sliding bearing.

[0005] For this reason, it is conceivable to make the columns supporting the seismic isolation device SRC (Steel Reinforced Concrete Construction). However, when the columns are made of SRC, after the steel frame is built, steel bar placement, formwork attachment, concrete placement, and formwork removal are carried out in order, the seismic isolation device is attached after the columns are completed, and then the construction of the steel frame above the seismic isolation device is carried out, resulting in a problem of a long construction period.

[0006] In view of the above facts, an object of the present invention is to provide a seismic isolation device installation structure that can shorten the construction period and can install the seismic isolation device at an early stage and construct the steel frame above the seismic isolation device without waiting for the reinforcement work and concrete placement of the lower part.

Means for Solving the Problems

[0007] First Aspect The seismic isolation device installation structure described in is provided with a reinforced concrete column, a steel pipe socket member joined to the upper part of the steel frame member of the column and filled with concrete inside, and a seismic isolation device installed on a base plate provided on the upper part of the steel pipe socket member. A connecting reinforcing bar having an upper part embedded in the concrete of the steel pipe socket member and a lower part protruding from the lower surface of the steel pipe socket member, and the connecting reinforcing bar and the column main reinforcing bar of the column are connected.

[0008] First Aspect The seismic isolation device installation structure described in is of a so-called CFT structure for the steel pipe socket member for installing the seismic isolation device, and the column supporting the steel pipe socket member is of a reinforced concrete structure.

[0009] Therefore, First Aspect In the seismic isolation device installation structure described in, if a steel pipe socket member is joined to the upper part of the steel frame member which is a part of the components of the reinforced concrete column and the inside of the steel pipe socket member is filled with concrete and cured, a seismic isolation device can be installed on the base plate provided on the upper part of the steel pipe socket member.

[0010] Therefore, since the construction of the steel frame above the seismic isolation device and the reinforcement work and formwork concrete placement work of the reinforced concrete column can be carried out in parallel, the construction period can be shortened.

[0011] Also, by connecting the connecting reinforcing bar protruding from the lower surface of the steel pipe socket member and the column main reinforcing bar, even if the structures of the two are different, such as the steel pipe socket member being CFT and the column being SRC, the axial force can be reliably transmitted from the socket part to the column.

[0012] Second Aspect The invention described in First Aspect In the seismic isolation device installation structure described in

[0013] Second Aspect In the seismic isolation device installation structure described in

[0014] Third Aspect The invention described in Second Aspect In the seismic isolation device installation structure described in

[0015] Third Aspect The invention described in Second Aspect In the seismic isolation device installation structure described in

Effect of the Invention

[0016] 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 early, and the steel frame construction above the seismic isolation device can be carried out without waiting for the reinforcement placement and concrete pouring below, which has excellent effects.

Brief Description of the Drawings

[0017]

Figure 1

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Figure 11

Embodiments for Carrying Out the Invention

[0018] Using FIGS. 1 to 11, 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. FIG. 1 shows the basement first floor portion of a seismic isolation structure 12 to which a seismic isolation device installation structure 10 according to the present 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 the present embodiment is a so-called intermediate floor seismic isolation building in which a seismic isolation device 60 is provided on an intermediate floor of the building.

[0019] On the upper part of the column 16, a steel pipe connection member 18 of CFT construction is provided. A beam 20 is attached to the side part of this steel pipe connection member 18, and a seismic isolation device 60 described later is installed on the upper part of the steel pipe connection member 18.

[0020] Note that in the ground G, a concrete pile 22 is buried directly below the column 16.

[0021] (Structure of Column) The column 16 has a steel skeleton 26, column main reinforcement bars 28, and stirrups 30 embedded inside the concrete 24. As an example, cross H-shaped steel is used for the steel skeleton 26 of the present embodiment, but other steel skeletons can also be used.

[0022] (Steel pipe connection member) The steel pipe connection member 18 includes a steel box 32 having an inverted trapezoidal shape in a side view configured such that the horizontal cross-sectional area decreases downward. The box 32 is formed with a tubular portion by four lower side plates 34 and four upper side plates 36. The upper opening of the tubular portion is closed by a base plate 38 as the upper part of the steel pipe connection member 18, and the lower side of the tubular portion is closed by a bottom plate 40 as the lower part of the steel pipe connection member 18.

[0023] The tubular portion is formed such that its axial direction is vertical, and a partition plate 42 is provided at the middle part in the vertical direction. The lower side plates 34, upper side plates 36, base plate 38, bottom plate 40, and partition plate 42 are all formed of steel plates.

[0024] As shown in Fig. 2(A), the base plate 38 is formed in a quadrangular shape in a plan view. A circular concrete placement hole 44 is formed at the center, and four rectangular concrete placement holes 46 are formed around the concrete placement hole 44.

[0025] 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.

[0026] As shown in Fig. 2(B), the partition plate 42 is formed in a quadrangular shape. As shown in Fig. 1, a concrete placement hole 48 similar to the concrete placement hole 46 is formed directly below the concrete placement hole 46 formed in the base plate 38.

[0027] As shown in FIGS. 1 and 2(C), a plurality (four in this embodiment) of connecting reinforcing bar through-holes 50 are formed in the bottom plate 40 directly below the concrete placing holes 48 of the partition plate 42. The connecting reinforcing bar through-holes 50 are penetrated by the connecting reinforcing bars 52 inserted from the concrete placing holes 46 and the concrete placing holes 48. Note that the connecting reinforcing bar through-holes 50 are formed to have a slightly larger diameter than the connecting reinforcing bars 52.

[0028] The connecting reinforcing bar 52 penetrates the connecting reinforcing bar through-hole 50 in the vertical direction, and the upper part is arranged inside the box 32 and is formed in an upper hook shape.

[0029] The lower end portion of the connecting reinforcing bar 52 protruding below the bottom plate 40 is joined to the upper end portion of the column main reinforcing bar 28 of the column 16 using a mechanical joint 54.

[0030] The inside of the box 32 is filled with concrete 58 and grout 76 without any gaps.

[0031] (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 this embodiment includes a sliding bearing 62 and a cylindrical laminated rubber 64, and the laminated rubber 64 and the sliding bearing 62 are arranged in series in the vertical direction. The laminated rubber 64 is formed by alternately laminating thin reinforcing steel plates 64A and rubber layers 64B.

[0032] A steel flange 66 formed in a disc shape is provided at the upper end portion of the laminated rubber 64, and this flange 66 is fixed to the superstructure 68 provided above the laminated rubber 64. Note that the shape of the laminated rubber 64 may be other than a cylindrical shape, for example, a prismatic shape.

[0033] The sliding bearing 62 includes a sliding plate 70 provided on the steel pipe spigot member side and a disc-shaped sliding material 72 provided on the rubber body side. The planar shape of the sliding plate 70 is square as an example.

[0034] The sliding plate 70 is fixed to the upper surface of the base plate 38 of the steel pipe joint member 18. Further, the sliding material 72 is fixed to the thick reinforcing steel plate 64C of the laminated rubber 64 and is in slidable contact with the sliding plate 70. Note that the planar shapes of the sliding plate 70 and the sliding material 72 may be other shapes.

[0035] (Superstructure) Above the laminated rubber 64, the superstructure 68 is supported. The superstructure 68 is, for example, a building having a plurality of inner columns (not shown) built on the seismic isolation device 60 and beams (not shown) installed between the column feet of adjacent inner columns. The column feet of the inner columns are column-beam joints, and the ends of the beams are joined.

[0036] (Construction procedure) Next, the construction procedure of the seismic isolation structure 12 of the present embodiment will be described.

[0037] (1) Steel frame construction of columns As shown in FIG. 4, after placing the concrete 78 that becomes the lower layer foundation of the foundation beam 14 on the ground G, build the steel frame members 26 on the upper side of the concrete pile 22. Then, attach the box 32 to the upper part of the steel frame members 26 and attach the beam 20 to the side part of the box 32. In FIG. 4 and other drawings, the steel bars inside the concrete 78 are not shown.

[0038] (2) Installation of connecting steel bars Next, as shown in FIG. 5, drop the connecting steel bar 52 from above the box 32 into the connecting steel bar through-hole 50 (see FIG. 2(C)) of the bottom plate 40, and project the lower end of the connecting steel bar 52 downward from the bottom plate 40. Note that the connecting steel bar 52 is temporarily held on the box 32 using a jig (not shown).

[0039] (3) Concrete placement As shown in Fig. 6, concrete 58 is placed into the box 32 from the concrete placing holes 44 or 46 of the box 32. In this embodiment, the concrete 58 is placed so that a gap-shaped space S1 is formed between the upper surface of the concrete 58 and the lower surface of the base plate 38. It is preferable to previously fill the gap with a filler or the like so that the concrete 58 does not leak out from the gap between the connecting rebar through holes 50 and the connecting rebars 52.

[0040] (4) Grout Filling After the concrete 58 has hardened, as shown in Fig. 7, non-shrinking grout 76 is filled 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 76 is brought into contact with the lower surface of the base plate 38. When the grout 76 has hardened, the steel pipe connection member 18 of the CFT structure is completed.

[0041] (5) Seismic Isolation Device Installation After the grout 76 has hardened, as shown in Fig. 8, the seismic isolation device 60 is mounted on the base plate 38, and the sliding plate 70 is fixed to the base plate 38. Note that the upper surface of the base plate 38 may be ground. After the seismic isolation device 60 is installed, it becomes possible to construct the steel frame of the superstructure 68 on the seismic isolation device 60.

[0042] (6) Connection of Column Main Rebars and Connecting Rebars, Reinforcement of Foundation Beams, Reinforcement of Columns on the Ground Floor, and Concrete Placement of Foundation Beams After the installation of the seismic isolation device 60 is completed, as shown in Fig. 9, the column main rebars 28 are arranged along the steel members 26, and the upper end portion of the column main rebars 28 and the lower end portion of the connecting rebars 52 of the steel pipe connection member 18 are connected by a mechanical joint 54. Thereafter, the stirrups 30 around the steel members 26 are reinforced, and the reinforcement 14A of the foundation beam 14 and the placement of the concrete 14B are carried out on the concrete 78.

[0043] (7) Column Concrete Placement After the concrete 14B of the foundation beam 14 has hardened, as shown in FIG. 10, a formwork 80 is provided around the steel skeleton 26, and the concrete 24 is pressed into the inside of the formwork through a hole (not shown) provided in the formwork 80. In this embodiment, the concrete 24 is pressed in so that a gap-shaped space S2 is formed between the concrete 24 and the bottom plate 40 of the steel pipe joint member 18.

[0044] (8) Grout filling After the concrete 24 has hardened, as shown in FIG. 11, a non-shrinking grout 82 is filled to fill the space S2 formed between the upper surface of the concrete 24 and the lower surface of the bottom plate 40, and the grout 82 is brought into contact with the lower surface of the bottom plate 40. As an example, the grout 82 is filled through a filling hole (not shown) formed on the side surface of the formwork 80.

[0045] (9) Removal of the column formwork After the grout 82 has hardened, the formwork 80 is removed, and the SRC column 16 is completed (see FIG. 1).

[0046] (Effect) The seismic isolation structure 12 of this embodiment is characterized in that the steel pipe joint member 18 is of CFT construction and the column 16 is of SRC construction. Therefore, before the completion of the column 16, the box 32 can be joined to the upper part of the steel skeleton 26, the concrete 58 can be placed inside the box 32, and after the grout 76 is filled and hardened, the seismic isolation device 60 can be installed. Therefore, the seismic isolation device 60 can be installed at an early stage, and the construction of the steel skeleton above the seismic isolation device 60 can be carried out without waiting for the reinforcement of the lower column 16 and the placement of the concrete. In addition, the construction of the steel skeleton above the seismic isolation device 60 and the reinforcement work and formwork concrete placement work of the steel-reinforced concrete column 16 can be carried out in parallel, thereby shortening the construction period.

[0047] Since the CFT construction only requires filling the steel pipe with concrete and hardening it, the construction on site is easier than the SRC construction that requires reinforcement, formwork installation, concrete filling, and formwork removal.

[0048] In the seismic isolation structure 12 of this embodiment, since the cross-sectional area of the column 16 is not determined according to the size of the sliding plate 70 of the seismic isolation device 60 with a bearing, it is not necessary to make the cross-sectional area of the column 16 larger than necessary, and the influence on the cost can also be suppressed.

[0049] In other words, the column 16 only needs to have the minimum cross-sectional area (thickness) capable of supporting the upper load, and can be made thinner compared to the case where the cross-sectional area of the column 16 is determined according to the size of the sliding plate 70.

[0050] Furthermore, in the seismic isolation device installation structure 10 of this embodiment, since the connecting reinforcing bar 52 protruding from the lower surface of the steel pipe joint member 18 is connected to the column main reinforcing bar 28 of the column 16, even if the structures of the two are different, such as the steel pipe joint member 18 being of CFT structure and the column 16 being of SRC structure, the axial force can be reliably transmitted from the steel pipe joint member 18 to the column 16.

[0051] [Other Embodiments] As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0052] In the above embodiment, the column main reinforcing bar 28 and the connecting reinforcing bar 52 are connected by the mechanical joint 54. However, the present invention is not limited to this, and the column main reinforcing bar 28 and the connecting reinforcing bar 52 may be joined by welding.

[0053] The seismic isolation device 60 of this embodiment is configured to include a sliding bearing 62 and a laminated rubber 64. However, the present invention is not limited to this, and the seismic isolation device 60 may be of other types.

[0054] In the above embodiment, the concrete 24 is press-fitted into the formwork 80 so that a gap-like space S2 is formed between the bottom plate 40 of the steel pipe joint member 18, and then the space S2 is filled with the grout 82. However, the concrete 24 may be press-fitted into the formwork 80 so that the space S2 is not formed.

[0055] In the above embodiment, concrete 58 was poured into the box 32 so that a gap-like space S1 was formed between the base plate 38 of the steel pipe joint member 18, and then the grout 76 was filled in the space S1. However, the concrete 58 may be poured into the box 32 so that the space S1 is not formed.

Explanation of Reference Numerals

[0056] 10 Seismic isolation device installation structure 16 Column 18 Steel pipe joint member 26 Steel frame member 28 Main reinforcement of column 38 Base plate 52 Connecting reinforcement 54 Mechanical joint 58 Concrete of steel pipe joint member 60 Seismic isolation device 62 Sliding bearing 64 Laminated rubber

Claims

1. A column made of reinforced concrete, a steel pipe socket member joined to the upper part of the steel reinforcement of the column and filled with concrete inside, a seismic isolation device installed on a base plate provided on the upper part of the steel pipe socket member, comprising: a connecting reinforcing bar with its upper part embedded in the concrete of the steel pipe socket member and its lower part protruding from the lower surface of the steel pipe socket member is connected to the column main reinforcing bars of the column, In a state where the upper part of the steel reinforcement of the steel structure construction is embedded in the concrete filled inside the steel pipe socket member, the base plate is formed with concrete placing holes so that the seismic isolation device can be installed on the base plate, and the lower part of the steel pipe socket member is closed with a bottom plate. Seismic isolation device installation structure.

2. The seismic isolation device includes a laminated rubber and a sliding bearing provided between the laminated rubber and the base plate. The seismic isolation device installation structure according to Claim 1.

3. The cross-sectional area of the upper part of the steel pipe socket member to which the base plate is attached is larger than the cross-sectional area of the lower part joined to the steel reinforcement of the column. The seismic isolation device installation structure according to Claim 2.

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