JP2010037800A - Base isolating method for existing building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base isolating method for an existing building that can reduce man-hours and working spaces required for base isolating work. <P>SOLUTION: The base isolating method for the existing building includes carrying out sequentially a connection concrete column forming step of forming connection concrete columns 6, 7 for connecting a column lower part 3 and a column upper part 5 of an existing concrete column 1; an existing concrete column cutting step of cutting off a column pull-out part 4 located between the column lower part 3 and the column upper part 5 of the existing concrete column 1; a base isolating apparatus installation step of installing a base isolating apparatus 10 in a space 8 formed by cutting off the column pull-out part 4 of the existing concrete column 1; and a connection concrete column cutting step of cutting off the connection concrete columns 6, 7 to allow the base isolating apparatus 10 to bear load which was imposed on the connection concrete columns 6, 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a seismic isolation method for isolating existing buildings.

Conventionally, a part of the reinforced concrete columns in the existing building where the seismic isolation device should be installed is dismantled, jacks are placed alongside the reinforced concrete columns to be demolished, and the seismic isolation device is installed at the position of the removed reinforced concrete columns. There is a seismic construction method (see Patent Documents 1 and 2).
JP-A-11-107540 JP-A-8-338155

  However, in such a conventional seismic isolation method for an existing building, a large number of man-hours are required for the replacement work of arranging jacks along with the reinforced concrete columns to be dismantled, and the construction period increases.

  In addition, although the jack bears the axial force of the reinforced concrete column but cannot bear the shearing force, it is necessary to provide a bracing around the jack, which increases the man-hours and work space required for the seismic isolation work.

  This invention is made | formed in view of said problem, and it aims at providing the seismic isolation method of the existing building which can reduce the man-hour and work space required for seismic isolation work.

  The present invention relates to a seismic isolation method for isolating an existing building, a process for forming a connected concrete column that connects a lower column and an upper column of an existing concrete column, and a column of an existing concrete column The excision process of the existing concrete column that excises the column extraction part located between the lower part and the upper part of the column, the installation process of the seismic isolation apparatus that installs the seismic isolation apparatus in the space where the column extraction part of the existing concrete column is excised, The connected concrete pillars are cut out in order, and the connected concrete pillars are cut in order to load the seismic isolation device with the load borne by the connected concrete pillars.

  According to the present invention, it is not necessary to carry out the refilling work using a jack or the like as in the conventional construction method, and the construction period can be shortened.

  In addition, the connecting concrete pillars bear axial force and shearing force during construction, so that the safety of the upper floor is ensured even when an earthquake occurs during construction, and bracing is provided during construction as in the conventional method There is no need, and man-hours and work space required for seismic isolation work can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1-5 shows the procedure of the seismic isolation construction method which installs the seismic isolation apparatus 10 in the existing building. 1 to 5, (a) is a cross-sectional view along a vertical plane of an existing building, and (b) is a cross-sectional view along the horizontal plane of the existing building.

  In the figure, 1 is a column of an existing building (hereinafter referred to as an existing concrete column), 22 is a lower structure of the existing building, and 23 is an upper structure of the existing building.

  Although the lower structure 22 is provided in a foundation part, it is not restricted to this, You may provide in the middle floor of the existing building.

  The upper structure 23 includes a slab 24, a horizontal beam 25, and a vertical beam 26.

  The existing concrete pillar 1 extends in the vertical direction, and its cross section is formed in a rectangular shape. The horizontal beam 25 and the vertical beam 26 extend in the horizontal direction from each side surface of the existing concrete column 1.

  A plurality of existing concrete columns 1 are provided between the lower structure 22 and the upper structure 23, and the seismic isolation devices 10 are respectively installed in the middle of all the existing concrete columns 1.

  The seismic isolation device 10 allows the lower structure 22 to be displaced in the horizontal direction while supporting the upper structure 23 in the vertical direction. By installing the seismic isolation device 10 between the lower structure 22 and the upper structure 23, the upper structure 23 is prevented from following the movement of the ground when an earthquake occurs, and the building is prevented from being destroyed.

  As shown in FIGS. 1A and 1B, a column extraction portion 4 is set in the middle of the existing concrete column 1. This pillar extraction part 4 becomes a site | part which installs the seismic isolation apparatus 10 so that it may mention later.

  A column lower part 3 and a column upper part 5 are set on the existing concrete column 1 with a column extraction part 4 interposed therebetween. As will be described later, the column lower portion 3 and the column upper portion 5 are portions to which the connected concrete columns 6 and 7 are connected.

  The column upper part 3 is set apart from the upper structure 23 by a predetermined height. The column upper portion 3 is not limited to this, and may be set so as to be connected to the beams 25 and 26 of the upper structure 23.

  The column lower part 3 is set apart from the lower structure 22 by a predetermined height. The column lower part 3 is not limited to this, and may be set so as to be connected to the lower structure 22.

  The seismic isolation method, which seismically isolates existing buildings, performs the following steps in order.

[Formation process of connected concrete pillars]
As shown in FIGS. 2A and 2B, two connected concrete columns 6, 7 that connect the lower column 3 and the upper column 5 of the existing concrete column 1 are formed, and the two connected concrete columns 6 are formed. , 7 is provided with a strength higher than the minimum strength required for the column extraction portion 4.

  The two connected concrete columns 6 and 7 are provided so as to sandwich the column extraction portion 4 and bear the necessary axial force and shearing force.

  However, the present invention is not limited to this, and in the case where the required strength is provided by one connected concrete column, one connected concrete column may be provided along one side of the column extraction portion 4.

The connected concrete columns 6 and 7 are formed by the following procedure.
1. The side surfaces 3a and 5a of the column lower portion 3 and the column upper portion 5 to which the connected concrete columns 6 and 7 are joined are suspended and roughened.
2. Reinforcing bars serving as anchors 27 are driven into the side surfaces of the column lower portion 3 and the column upper portion 5 to which the connected concrete columns 6 and 7 are joined.
3. Form a mold (not shown) so as to surround the existing concrete pillar 1.
4). A partition plate (not shown) is attached to the inside of the assembled form along the side surface 4a of the column extraction portion 4 so that a gap 28 is formed between the side surface 4a of the column extraction portion 4 and the connecting concrete columns 6 and 7. To do.
5). A reinforcing bar (not shown) is assembled inside the formwork. However, the present invention is not limited to this, and the reinforcing bars may be abolished when the necessary axial force and shearing force can be borne without providing the reinforcing bars.
6). The ready-mixed concrete is poured into the formwork, and the concrete is solidified to form the connected concrete columns 6 and 7.

[Excision process of existing concrete pillars]
As shown in FIGS. 3A and 3B, the column extraction portion 4 of the existing concrete column 1 is cut out to form a space 8.

  In this excision process of the existing concrete pillar, for example, the existing concrete pillar 1 is cut at two upper and lower portions using a wire saw (not shown), and the pillar extraction portion 4 separated by this cutting is extracted. As a result, the existing concrete column 1 is formed such that the lower surface 3b of the cut portion is formed in a horizontal plane at the lower portion 3 of the column, and the upper surface 5b of the cut portion is formed in a horizontal plane at the upper portion 5 of the column. A space 8 is defined between the two.

  Even if the existing concrete column 1 is cut out, the connecting concrete columns 6 and 7 bear the axial force and shearing force that the column extracting unit 4 has borne. Will not be generated.

[Seismic isolation device installation process]
As shown in FIGS. 4A and 4B, the seismic isolation device 10 is installed in the middle of the existing concrete column 1.

  The seismic isolation device 10 uses a laminated rubber isolator in which metal plates and rubber are alternately stacked between a disk-shaped lower iron plate 11 and an upper iron plate 12 extending in the horizontal direction. However, the seismic isolation device 10 is not limited to this, and may be configured by, for example, a ball slide rail.

  In the installation process of the seismic isolation device, the seismic isolation device 10 is lifted to the same height as the space 8 and then moved in the horizontal direction to be interposed in the space 8.

  The cut portion lower surface 3b and the lower iron plate 11, and the cut portion upper surface 5b and the upper iron plate 12 are joined by filling the gaps with mortar. Not limited to this, the cut portion lower surface 3b and the lower iron plate 11, and the cut portion upper surface 5b and the upper iron plate 12 may be joined using anchors.

  Alternatively, the seismic isolation device 10 may be cooled in advance and interposed in the space 8 with the seismic isolation device 10 contracted.

  By repeating the above steps, the seismic isolation device 10 is installed in the middle of all existing concrete columns 1. And the cutting process of the next connection concrete pillar is performed.

[Removal process of connected concrete pillars]
As shown in FIGS. 5A and 5B, the connected concrete columns 6 and 7 are cut so that the seismic isolation device 10 bears the axial force and shear force that the connected concrete columns 6 and 7 have borne. .

  In the step of cutting the connected concrete pillars, for example, the connected concrete pillars 6 and 7 are cut at two upper and lower positions using a wire saw (not shown), and the parts cut off by the cutting are extracted. As a result, spaces 16 and 17 are formed.

  The heights of the spaces 16 and 17 are set to a minimum within a range in which the remaining portions of the connected concrete columns 6 and 7 do not interfere with each other when the seismic isolation device 10 is operated.

  In addition, you may remove, without leaving not only this but the connection concrete pillars 6 and 7. FIG.

  In all the existing concrete pillars 1, the seismic isolation work for the existing buildings is completed by performing the above-described cutting process of the connected concrete pillars.

  In the existing building thus subjected to the seismic isolation work, when the earthquake occurs, the lower structure 22 is shaken following the movement of the ground, while the seismic isolation device 10 is activated to absorb the vibration energy. 23 shaking is suppressed.

  In this embodiment, it is a seismic isolation method for seismic isolation of an existing building, and the formation of a connected concrete column that forms the connected concrete columns 6 and 7 that connect the lower column 3 and the upper column 5 of the existing concrete column 1. The process, the excision process of the existing concrete column that excises the column extraction portion 4 located between the column lower portion 3 and the column upper portion 5 of the existing concrete column 1, and the space 8 that excises the column extraction portion 4 of the existing concrete column 1 The installation process of the seismic isolation device for installing the seismic isolation device 10 to the seismic isolation device 10 and the connected concrete columns 6 and 7 are excised to load the load borne by the connected concrete columns 6 and 7 to the seismic isolation device 10. The cutting process is sequentially performed.

  This eliminates the need for rearrangement work using a jack or the like as in the conventional construction method, thereby shortening the construction period. In addition, the connecting concrete columns 6 and 7 bear the axial force and shearing force during construction, so that the safety of the upper floor is ensured even in the event of an earthquake during construction. There is no need to provide braces, and the man-hours and work space required for seismic isolation work can be reduced.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

Sectional drawing of the existing building which shows embodiment of this invention. Sectional drawing of the formation process of a connection concrete pillar similarly. Sectional drawing of the cutting process of the existing concrete pillar similarly. Sectional drawing of the installation process of a seismic isolation device. Sectional drawing of the cutting process of a connection concrete pillar similarly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Existing concrete pillar 3 Lower pillar 4 Column extraction part 5 Upper pillar 6 Connection concrete pillar 7 Connection concrete pillar 8 Space 10 Seismic isolation device

Claims (1)

A seismic isolation method for seismic isolation of existing buildings,
A process of forming a connected concrete column that forms a connected concrete column that connects the lower part and the upper part of the existing concrete column;
Cutting the existing concrete column to cut out a column extraction portion located between the column lower portion and the column upper portion of the existing concrete column;
An installation process of the seismic isolation device for installing the seismic isolation device in the space where the column extraction part of the existing concrete column is excised;
A seismic isolation method for an existing building, in which a step of excising the connected concrete column is performed in order by excising the connected concrete column and causing the seismic isolation device to bear the load borne by the connected concrete column.

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