JP2018154987A - Base isolation repair method and base isolation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the work efficiency of a base isolation repair in which a base isolation device is installed at a lower end part of a reinforced concrete column.SOLUTION: A base isolation structure 10 includes a steel pipe 50 provided around the lower end part 32 of a reinforced concrete column 30, a steel beam 70 joined to the steel pipe 50, a base isolation device 38 for supporting the steel pipe 50, a filler J filling a gap between the lower end part 32 of the reinforced concrete column 30 and the steel pipe 50, a recessed portion 34 formed in the outer peripheral portion 32B of the lower end part 32 of the reinforced concrete column 30, and a projecting portion 54 provided on the inner wall 50B of the steel pipe 50.SELECTED DRAWING: Figure 1

Description

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

  Patent Document 1 discloses a technique relating to a middle floor seismic isolation structure in which a seismic isolation device is installed in a part of a pillar on a middle floor of a building. In this prior art, a steel plate is wound around the outer circumference of a column where a seismic isolation device is installed, and a column base rebar with a base end fixedly supported on the lower floor is arranged on the inner peripheral side of the steel plate leg. Has been.

  Patent Document 2 discloses a technique related to a method for extending a lower floor of an existing building. In this prior art, a lower floor such as a first floor in an existing relatively low-rise building is expanded by pushing up the upper floor.

  Here, in the seismic isolation repair which installs a seismic isolation apparatus in the lower end part of the existing reinforced concrete pillar, in order to cut | disconnect the lower end part of a reinforced concrete pillar, it is necessary to support a reinforced concrete pillar beforehand with a jack. In general, temporary decks, brackets, and the like that serve as jack support are constructed on reinforced concrete columns. In addition, after installing a seismic isolation device at the lower end of the reinforced concrete column, the deck and brackets are removed.

  Therefore, there is room for improvement in improving the work efficiency of the seismic isolation repair in which a seismic isolation device is installed at the lower end of the reinforced concrete column.

JP-A-2005-155131 JP 2005-26469 A

  In view of the above facts, the present invention has an object to improve the work efficiency of seismic isolation repair in which a seismic isolation device is installed at the lower end of a reinforced concrete column.

  The invention according to claim 1 includes a step of providing column side axial force transmission means on the outer peripheral portion of the lower end portion of the reinforced concrete column, and a steel pipe divided into a plurality of pieces and provided with steel pipe side axial force transmission means on the inner wall. Attaching to the periphery of the force transmission means, filling the gap between the lower end of the reinforced concrete column and the steel pipe with a filler, joining the steel beam to the steel pipe, and supporting the steel beam with a jack; A seismic isolation repair method comprising a step of cutting the reinforced concrete column below the steel pipe, a step of installing a seismic isolation device that supports the steel pipe, and a step of removing the jack.

  In the first aspect of the present invention, the divided steel pipe surrounds the lower end portion of the reinforced concrete column before cutting from the periphery, the filler is filled between the lower end portion of the reinforced concrete column and the steel pipe, and the steel pipe is filled in the steel beam. Join. Thereby, the axial force acting on the reinforced concrete column can be transmitted to the steel pipe and the steel beam via the column side axial force transmission means, the steel pipe side axial force transmission means, and the filler. Then, the steel beam is supported by a jack as a support receiver, the lower end portion of the reinforced concrete column is cut off, a seismic isolation device for supporting the steel pipe is installed, and the jack is removed.

  Therefore, there is no need to construct a temporary deck, bracket, etc., which will be a support support for the jack, on a reinforced concrete column and remove it after the seismic isolation repair. Therefore, the work efficiency of the seismic isolation repair which installs a seismic isolation apparatus in the lower end part of a reinforced concrete pillar improves.

  Invention of Claim 2 is the steel pipe provided around the lower end part of a reinforced concrete pillar, the steel beam joined to the steel pipe, the seismic isolation device which supports the steel pipe, the lower end part of the reinforced concrete pillar, and the steel pipe An axial force transmission means for transmitting the axial force acting on the reinforced concrete column via the filler, the filler filled in the gap, the lower end of the reinforced concrete column and the steel pipe; This is a seismically isolated structure.

  In the invention according to claim 2, the axial force acting on the reinforced concrete column is transmitted to the steel pipe provided around the lower end portion of the reinforced concrete column via the filler by the axial force transmitting means, so that the steel pipe A reinforced concrete column can be supported with a jack using the joined steel beam as a support receiver.

  Therefore, it is not necessary to construct a temporary deck, bracket, etc. that will be supported by the jack and remove it after the repair, improving the work efficiency of the seismic isolation repair by installing a seismic isolation device at the lower end of the reinforced concrete column .

  Invention of Claim 3 is a seismic isolation structure of Claim 1 in which the penetration bolt which penetrates the outer peripheral part of a reinforced concrete pillar and the said steel pipe is provided.

  In invention of Claim 3, since the penetration bolt has penetrated the outer peripheral part and steel pipe of a reinforced concrete pillar, the axial force which acts on a reinforced concrete pillar can be reliably transmitted with a steel pipe.

  According to the present invention, the work efficiency of seismic isolation repair in which a seismic isolation device is installed at the lower end of a reinforced concrete column is improved.

It is a vertical sectional view along line 1-1 of FIG. 2 of the main part of the base isolation structure to which the base isolation structure of the present embodiment is applied. It is a horizontal sectional view along line 2-2 of Drawing 1 of an important section of a base isolation structure to which a base isolation structure of this embodiment was applied. It is a top view which shows the state which the steel pipe unit divided | segmented. It is process drawing which shows the seismic isolation repair process of this embodiment in order to (A)-(D). It is process drawing which shows the seismic isolation repair process of this embodiment in order to (A)-(E). It is process drawing corresponding to FIG. 5 which shows the seismic isolation repair process of a comparative example in order to (A)-(E).

<Embodiment>
A seismic isolation structure according to an embodiment of the present invention will be described.
[Construction]
First, the main structure of the seismic isolation structure 10 to which the seismic isolation structure of this embodiment is applied will be described.

  In addition, the seismic isolation structure 10 shown to FIG.1 and FIG.5 (E) is a structure where the existing structure 11 (refer FIG. 5 (A)) was seismically isolated and repaired.

  As shown in FIG. 1, in the base isolation structure 10, a base isolation device 38 is installed on a reinforcement base 21 (see also FIG. 5A) that reinforces an existing base 20, and a steel pipe 50 is attached to the base isolation device 38. It is supported. In addition, in this embodiment, although the seismic isolation apparatus 38 uses laminated rubber, it is not limited to this. A bottom plate 52 is joined to the bottom of the steel pipe 50, and the base plate 52 is supported by the seismic isolation device 38.

  A steel beam 70 made of H-shaped steel is joined to the outer peripheral portion 50 </ b> A of the steel pipe 50. The steel beam 70 functions as a foundation beam and supports the slab 22 on the foundation floor. The steel beam 70 includes a bracket 72 joined to the outer peripheral portion 50 </ b> A of the steel pipe 50 and a beam body 74 joined to the bracket 72. In the present embodiment, the bracket 72 and the beam main body 74 are bolted via a joining plate (not shown). Further, the inner wall 50B of the steel pipe 50 is provided with a convex portion 54 that functions as a cotter.

  In the steel pipe 50, the lower end 32 of the reinforced concrete column 30 is inserted. The lower end surface 32 </ b> A of the lower end portion 32 is in contact with or close to the bottom plate 52 joined to the bottom portion of the steel pipe 50. Moreover, the recessed part 34 which functions as a cotter is formed in the outer peripheral part 32B of the lower end part 32 of the reinforced concrete pillar 30. As shown in FIG. In addition, the convex part 54 of the inner wall 50B of the steel pipe 50 and the concave part 34 of the outer peripheral part 32B of the lower end part 32 of the reinforced concrete column 30 are provided so that the vertical position may be substantially the same position.

  A gap between the outer peripheral portion 32B of the lower end portion 32 of the reinforced concrete column 30 and the steel pipe 50 is filled with a filler J such as concrete or mortar. Moreover, in this embodiment, the penetration bolt 60 has penetrated the outer peripheral part 32B of the lower end part 32 of the reinforced concrete pillar 30, the steel pipe 50, and the filler J.

  As shown in FIG. 2, an outer diaphragm 80 is joined to the outer peripheral portion 50 </ b> A of the steel pipe 50 and the steel beam 70. The outer diaphragm 80 is not shown except in FIGS. The steel pipe 50 in a state where the bracket 72 and the outer diaphragm 80 are joined is referred to as a steel pipe unit 88.

  As shown in FIG. 3, the steel pipe 50 includes a divided steel pipe 51 and a divided steel pipe 53 that are divided into two. The divided steel pipe 51 and the divided steel pipe 53 are provided with a joining flange 51A and a joining flange 53A, respectively. The outer diaphragm 80 joined to the steel pipe 50 is also divided into a divided diaphragm 81 and a divided diaphragm 83. The divided steel pipes 51 and 53, the bracket 72, and the divided diaphragms 81 and 83 are joined to constitute divided steel pipe units 85 and 87.

  As shown in FIG. 2, the joining flange 51 </ b> A of the split steel pipe 51 and the joining flange 53 </ b> A of the split steel pipe 53 are overlapped and bolted to form a steel pipe unit 88.

[Seismic isolation repair process]
Next, an example of the seismic isolation repair process of making the base isolation structure 10 (FIGS. 1 and 5E) by isolating the existing structure 11 (FIG. 5A) will be described.

  The existing structure 11 shown in FIG. 5A is a reinforced concrete structure. Then, a reinforcing foundation 21 is placed on the existing foundation 20 of the existing structure 11 to be reinforced. As illustrated in FIG. 1, the outer peripheral portion 32 </ b> B of the lower end portion 32 of the reinforced concrete column 30 is rolled to form a concave portion 34. In addition, a through hole (not shown) through which the through bolt 60 passes is formed in the lower end portion 32.

  As shown in FIGS. 4A and 5B, a steel pipe unit 88 (steel pipe 50) is provided around the lower end portion 32 of the reinforced concrete column 30. At this time, the divided steel pipe unit 85 (the divided steel pipe 51 (see FIG. 3)) and the divided steel pipe unit 87 (the divided steel pipe 51 (see FIG. 3)) are installed so as to sandwich the lower end 32 of the reinforced concrete column 30 and divided. The joining flange 51A of the steel pipe 51 and the joining flange 53A of the split steel pipe 53 are integrated by overlapping and bolted to form a steel pipe unit 88 (see also FIGS. 1 and 2).

  Moreover, as shown in FIG.1 and FIG.2, the penetration bolt 60 is penetrated to the outer peripheral part 32B and the steel pipe 50 of the lower end part 32 of the reinforced concrete pillar 30, and it fixes with a nut. Thereby, the steel pipe unit 88 is temporarily fixed to the lower end 32 of the reinforced concrete column 30.

  As shown in FIGS. 4B and 5C, the beam main body 74 is joined to the bracket 72 joined to the steel pipe 50. Further, as shown in FIG. 5C, the slab 22 is placed on the steel beam 70.

  As shown in FIG. 4C, the filler J is filled in the gap between the steel pipe 50 and the lower end portion 32 of the reinforced concrete column 30. At this time, the gap between the lower end 50C of the steel pipe 50 and the lower end 32C of the lower end 32 of the reinforced concrete column 30 is sealed with a sealing member 59 so that the filler J does not leak from below.

  When the filler J is solidified, the axial force acting on the reinforced concrete column 30 can be transmitted to the steel pipe 50 via the concave portion 34 of the lower end portion 32 of the reinforced concrete column 30, the convex portion 54 of the steel pipe 50 and the filler J shown in FIG. It becomes.

  As shown in FIGS. 4D and 5D, a jack 150 is installed on the reinforcing foundation 21 and the existing foundation 20 below the steel beam 70, and the steel beam 70 is supported by the jack 150 (see also FIG. 1). ). And the lower part 33 of the steel pipe 50 of the lower end part 32 of the reinforced concrete pillar 30 is cut off, and the bottom plate 52 (refer FIG.5 (D) and FIG. 1) is joined to the bottom part of the steel pipe 50. FIG.

  In addition, as mentioned above, since it transmits to the steel pipe 50 via the recessed part 34 of the lower end part 32 of the reinforced concrete pillar 30 shown in FIG. 1, the convex part 54 of the steel pipe 50, and the filler J, the lower end part 32 of the reinforced concrete pillar 30 is shown. Even if the portion 33 is cut out, the steel beam 70 joined to the steel pipe 50 can be supported by the jack 150 as a support receiver.

  As shown in FIG.1 and FIG.5 (E), the seismic isolation apparatus 38 was installed between the baseplate 52 joined to the steel pipe 50, and the reinforcement base 21 (referred part 33 (refer FIG.4 (D))). After that, the jack 150 (see FIGS. 1 and 5D) is removed.

  The through bolt 60 may be removed after the seismic isolation repair or may be left as it is.

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

  The steel pipe 50 is composed of a split steel pipe 51 and a split steel pipe 53 that are divided into two parts, and a bracket 72 and split diaphragms 81 and 83 are joined to form split steel pipe units 85 and 87.

  And the steel pipe is provided in the lower end part 32 of the reinforced concrete pillar 30 by surrounding the lower end part 32 of the reinforced concrete pillar 30 before a cutting | disconnection with the divided steel pipe 51 (divided steel pipe unit 85) and the divided steel pipe 53 (divided steel pipe unit 87). 50 (steel pipe unit 88) can be provided.

  By filling the filler J between the lower end portion 32 of the reinforced concrete column 30 and the steel pipe 50, the axial force acting on the reinforced concrete column 30 is converted into the concave portion 34 at the lower end portion 32 of the reinforced concrete column 30 and the convex portion 54 of the steel pipe 50. And it becomes possible to transmit to the steel pipe 50 through the filler J.

  Therefore, it is possible to install the seismic isolation device 38 that supports the steel pipe 50 by supporting the steel beam 70 with the jack 150 as a support receiver, cutting the lower portion 33 of the steel pipe 50 at the lower end portion 32 of the reinforced concrete column 30.

  Here, the seismic isolation repair process of the comparative example to which this invention is not applied is demonstrated using FIG. In the comparative example, the foundation beam is a reinforced concrete beam 700.

  As shown in FIG. 6A, the existing structure 11 is a reinforced concrete structure. Then, a reinforcing foundation 21 is placed on the existing foundation 20 of the existing structure 11 to be reinforced.

  As shown in FIG. 6B, a temporary support receiving member 800 such as a deck or a bracket serving as a support receiving of the jack 150 is constructed at the lower end portion 32 of the reinforced concrete column 30. Then, the jack 150 is installed on the reinforcing foundation 21 and the existing foundation 20, and the temporary support receiving member 800 is supported by the jack 150.

  As shown in FIG. 6C, the lower part of the lower end 32 of the reinforced concrete column 30 is cut out.

  As shown in FIG. 6D, after the seismic isolation device 38 is installed, the jack 150 is removed and the temporary support receiving member 800 is removed.

  As shown in FIG. 6E, the slab 22 is placed on the reinforced concrete beam 700.

  As described above, in the comparative example, the temporary support receiving member 800 such as a deck or a bracket serving as the support receiving of the jack 150 is constructed at the lower end portion 32 of the reinforced concrete column 30 and removed after the seismic isolation repair.

  On the other hand, in this embodiment, since the steel beam 70 is used as a support receiver for the jack 150, there is no need to construct a temporary support receiver member 800 such as a deck or a bracket on the reinforced concrete column 30, and this is removed. There is no need to do.

  Therefore, the work efficiency of the seismic isolation repair which installs the seismic isolation apparatus 38 in the lower end part 32 of the reinforced concrete pillar 30 improves. Further, in this embodiment, since the slab 22 can be driven in advance (see FIG. 5C), the working efficiency is also improved in this respect.

  In the present embodiment, the steel pipe unit 88 is temporarily fixed to the lower end portion 32 of the reinforced concrete column 30 by the through bolt 60. Moreover, since the penetration bolt 60 has penetrated the outer peripheral part 32B of the lower end part 32 of the reinforced concrete pillar 30, the steel pipe 50, and the filler J, the axial force which acts on the reinforced concrete pillar 30 can be reliably transmitted by the steel pipe 50. .

  In the embodiment, since the outer diaphragm 80 that resists bending deformation is joined to the steel pipe 50 and the steel beam 70, bending deformation of the steel beam 70 when supported by the jack 150 is suppressed.

<Others>
The present invention is not limited to the above embodiment.

  For example, in the said embodiment, although the steel pipe 50 was divided | segmented into two, it is not limited to this. It may be divided into three or more.

  For example, in the said embodiment, although the penetration bolt 60 penetrated, the penetration bolt 60 does not need to penetrate.

  Further, for example, in the above embodiment, the outer diaphragm 80 is joined to the steel pipe 50, but the outer diaphragm 80 may not be joined.

  Further, for example, in the above embodiment, the axial force of the reinforced concrete column 30 is transmitted to the steel pipe 50 via the concave portion 34 of the lower end portion 32 of the reinforced concrete column 30, the convex portion 54 of the steel pipe 50, and the filler J. It is not limited to. Other than the concave portion 34 and the convex portion 54 that function as these cotters, for example, a configuration in which the axial force is transmitted by a stud may be employed.

  Furthermore, the present invention can be implemented in various modes without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Seismic isolation structure 11 Existing structure 30 Reinforced concrete pillar 32 Lower end part 32B Outer peripheral part 34 Recessed part (an example of column side axial force transmission means)
38 Seismic isolation device 50 Steel pipe 50B Inner wall 54 Convex part (an example of steel pipe side axial force transmission means)
60 Through bolt 70 Steel beam 150 Jack
J Filler

Claims (3)

Providing the column side axial force transmission means on the outer periphery of the lower end of the reinforced concrete column;
Attaching a steel pipe divided into a plurality and provided with steel pipe side axial force transmission means on the inner wall around the column side axial force transmission means;
Filling a gap between the lower end of the reinforced concrete column and the steel pipe with a filler and joining a steel beam to the steel pipe;
Supporting the steel beam with a jack;
Cutting the reinforced concrete column below the steel pipe;
Installing a seismic isolation device for supporting the steel pipe;
Removing the jack;
A seismic isolation repair method. A steel pipe provided around the lower end of the reinforced concrete column;
A steel beam joined to a steel pipe,
A seismic isolation device for supporting the steel pipe;
A filler filled in the gap between the lower end of the reinforced concrete column and the steel pipe;
Axial force transmitting means provided at the lower end of the reinforced concrete column and the steel pipe, and transmitting axial force acting on the reinforced concrete column to the steel pipe via the filler,
Seismic isolation structure with A through bolt that penetrates the outer peripheral portion of the reinforced concrete column and the steel pipe is provided,
The seismic isolation structure according to claim 2.