JP5647448B2 - Column repair method for multi-story building - Google Patents

Description

  The present invention relates to a column repair method for a multi-story building.

For example, for repairs to reinforce specific pillars or repairs of pillars damaged by an earthquake, the axial force applied to the planned repair site of the repaired pillars must be unloaded before repair work. As a method of unloading, generally, a temporary steel column with a jack is installed between the floor slab and the end of the large beam on both sides of the column, and anchors are installed above and below the planned repair site of the column, and the upper and lower anchors are equipped with jacks. A method for attaching both ends of a temporary steel column is known.
However, the former method can be used when the axial force applied to the column is small in a relatively low-rise building, but it cannot be used in a high-rise building because the strength of the large beam cannot be accommodated when the axial force applied to the column increases. It becomes difficult.
Moreover, although the latter method can cope with a high-rise building where the axial force applied to the pillar is large, if the bar arrangement in the pillar is dense, it may be difficult to install the anchor and may not be used.

  Therefore, a temporary extension member that surrounds and holds the entire circumference of the column is provided above and below the planned repair site of the column, and a temporary steel column with a jack is provided between the upper and lower temporary extension members. It is conceivable to use a method of unloading the axial force of the planned repair site by exerting the stretching force (see, for example, Patent Document 1).

JP 2006-83516 A

  In the above-described method, since the extension force from the jack is transmitted to the column via the temporary support extending member, the distance from the column to the temporary steel column with the jack is increased. Moment acts on the member, the holding posture of the temporary support overhanging member becomes unstable, and sufficient frictional force is not generated between the temporary support overhanging member and the column, and the temporary support overhanging member is reinforced. Otherwise, there is a problem that the extension force due to the jack cannot be efficiently transmitted to the column, and the bending force is easily applied to the temporary steel column due to the moment with respect to the temporary support projecting member, and this temporary steel column is also reinforced. There is a problem of having to.

  Accordingly, an object of the present invention is to eliminate the above-mentioned problems and to enable unloading of an axial force at a planned repair site of a column by a simple method.

The first characteristic configuration of the present invention is that a temporary support column with a jack made of steel material is vertically aligned on both side surfaces facing each other of the repair target column from the lower column part to the upper column part than the planned repair site . And at least a pair in a state of being in contact with the side surface of the column to be repaired, and generating a frictional force by pressing the temporary column to the lower column portion and the upper column portion, Unload the axial force applied to the planned repair site of the pillar to be repaired via the temporary support column, and make the repair work on the planned repair site, and then release the extension force from the jack. Thus, an axial force is introduced into the repair target pillar.

According to the first characteristic configuration of the present invention, the temporary support column with the jack directly transmits the extension force of the jack to the column to be repaired by the frictional force with the opposite side surfaces of the column to be repaired. Can often unload planned repair points.
Therefore, it is possible to unload and repair the planned repair site by simply pressing the temporary support column directly against the repair target column without reinforcing the temporary support column more than necessary. By simply releasing the extension force caused by the building, the strength of the pillars to be repaired can be exhibited in the building.

The second characteristic configuration of the present invention is such that the lower pillar of the lower floor and the upper floor of the upper floor below the floor where the planned repair location is located in the repair target pillar. And the temporary strut is disposed,
The lower column portion for pressing the temporary support column is set to the lower floor column, and the upper column portion for pressing the temporary column is set to the upper column.

According to the second characteristic configuration of the present invention, by setting the location where the frictional force of the temporary support column acts on the repair target column to the upper and lower floor columns, the extension force of the jack is By acting on a wider range in the vertical direction, the unloading range of the axial force of the column can be greatly expanded.
Therefore, a wide range of column repair work can be performed.

  According to a third characteristic configuration of the present invention, a plurality of temporary columns are arranged on the floor where the planned repair site in the repair target pillar, the floor on which the lower floor pillar is located, and the floor on which the upper floor pillar is located. Are provided separately from each other, and are provided so as to be able to transmit axial forces to each other vertically.

  According to the third characteristic configuration of the present invention, by providing a plurality of temporary struts across the upper and lower floors so as to transmit axial force to each other, it is possible to easily install the temporary struts, Renovation will be possible.

  According to a fourth characteristic configuration of the present invention, the temporary support column extends over the floor where the planned repair site is located in the repair target pillar, the floor where the lower floor pillar is located, and the floor where the upper floor pillar is located. , In a place formed by a series of members provided so as to penetrate the floor slab of each floor.

  According to the 4th characteristic structure of this invention, the axial force unloading effect | action with respect to a repair object pillar can be performed efficiently by the temporary support | pillar formed with a series of members which penetrate a floor slab.

  According to a fifth characteristic configuration of the present invention, there is provided a clamping steel material including a pair of pressing portions that sandwich the lower column portion or the upper column portion and the at least one pair of temporary columns in order to generate the frictional force. The temporary support column is pressed against the column to be repaired by the lower column portion and the upper column portion by the tension of the PC steel rod provided and spanned across the pair of pressing portions.

  According to the fifth characteristic configuration of the present invention, in order to exert the frictional force by pressing the temporary support column at the lower column part or the upper column part, the tension force acting on the PC steel rod is used to sandwich the steel material for clamping. It is only necessary to press the temporary support column against the column to be repaired, and the column can be repaired by a simple method.

It is a whole perspective view. (A) A cross-sectional view, (b) a side view. It is a longitudinal cross-sectional view of a floor slab. It is a longitudinal cross-sectional view of a floor slab. It is a construction drawing of another embodiment, (a) a cross-sectional view, (b) a side view. It is a cross-sectional view of another embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
As shown in FIGS. 1 and 2, in a multi-story building where columns made of reinforced concrete (RC structure) are connected across the multi-story floor, the repair target has a repair target part that requires repair work for reinforcement. The pillar is repaired for the pillar 1 in the following process.
1. At least a pair of temporary columns 3 with jacks 2 made of H-shaped steel as steel materials are provided on both side surfaces of the column 1 to be repaired facing each other from the lower column portion 1B to the upper column portion 1C rather than the planned repair location 1A.
2. A U-shaped sandwiching steel material 5 in a plan view in which a pair of pressing portions 4 for sandwiching a pair of temporary support columns 3 on both ends is provided between the lower column portion 1B and the upper column portion 1C, respectively, from an H-shaped steel. Formed and arranged (FIG. 2 (a)),
3. PC steel rod is bridged across a pair of pressing parts 4 in the steel material 5 for clamping, the PC steel rod is pulled, and the temporary support column 3 is repaired by the lower column portion 1B and the upper column portion 1C by the tension force. Press against the pillar 1 to generate a frictional force between them,
4). Unload the axial force applied to the repair planned portion 1A of the repair target column 1 via the temporary support column 3 by causing the jack 2 to exert an extension force (FIG. 2 (b)),
5. After renovating the planned refurbishment point 1A,
6). The extension force by the jack 2 is released, and the axial force is introduced into the repair target column 1.

The lower column portion 1B is a lower floor column below the floor where the planned repair location 1A of the repair target column 1 is located, and the upper column portion 1C is the repair planned location 1A of the repair target column 1 It is an upper floor pillar above the floor where the floor is located, and a plurality of temporary support columns 3 are arranged on the floor where the planned repair location 1A, the floor where the lower floor pillar is located, and the floor where the upper floor pillar is located. Are provided separately from each other and capable of transmitting axial forces to each other vertically.
That is, in order to provide a plurality of temporary struts 3 in the vertical direction so that axial force can be transmitted to each other in the vertical direction, as shown in FIG. Reinforce with. Alternatively, as shown in FIG. 3, a steel plate 8 larger than the cross section of the temporary support column 3 is interposed between the floor slab 7 and the temporary support column 3.

[Second Embodiment]
5 (a) and 5 (b), the temporary support column 3 is arranged on the floor where the planned repair location 1A is located in the pillar 1 to be repaired, and in the two floors where the lower floor pillar is located, and the upper floor. An example is shown in which it is formed of a series of members provided so as to penetrate through the floor slab 7 of each floor over the two floors where the pillars are located.
When the main temporary support 3A cannot be pressed against the repair target column 1 in the center in the width direction in a cross-sectional view, the main temporary support 3A is pressed against the repair target column 1 due to the tension of the PC steel rod. After that, in order to prevent the moment of rotation from acting on the holding steel material 5 due to the extension operation by the jack 2, an auxiliary temporary support column 3B with a pair of jacks 2 is placed on the side opposite to the PC steel rod in the column width direction. This auxiliary temporary column 3B also extends the jack 2. At this time, the extension force of the jack 2 with respect to the auxiliary temporary support column 3B may be smaller than the extension force of the jack 2 of the main temporary support column 3A.

[Another embodiment]
Other embodiments will be described below.

<1> The present invention can be applied even if the repair target column 1 is a column made of steel (S) or reinforced steel (SRC) other than a column made of reinforced concrete (RC).
<2> As shown in FIG. 6, a pair of H-shaped steels disposed on both sides of the repair target column 1 is provided as the sandwiching steel material 5, and PCs are provided at both ends of the pair of H-shaped steels. The structure which presses the temporary support | pillar 3 to the repair object pillar 1 with tension | tensile_strength reaction force by attaching a steel bar and tensioning a PC steel bar may be sufficient.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Column to be repaired 1A Planned repair location 1B Lower column portion 1C Upper column portion 2 Jack 3 Temporary column 4 Pressing portion 5 Steel for clamping 6 PC steel rod

Claims (5)

Temporary columns with jacks made of steel are placed on both side surfaces of the column to be repaired facing each other from the lower column part to the upper column part from the planned repair site , and the repair target At least a pair along the side surface of the pillar ,
The lower column part and the upper column part are pressed against the temporary column to generate a frictional force,
Unloading the axial force applied to the planned repair site of the repair target column via the temporary support column by exerting an extension force on the jack,
After renovation construction of the planned renovation,
A column repair method for a multi-story building in which an extension force by the jack is released and axial force is introduced into the repair target column. The temporary support column is arranged continuously to the pillar to be repaired, and extends between the lower floor pillar of the floor below the floor where the planned repair spot is located and the upper floor pillar of the upper floor. ,
The method for repairing a column of a multi-story building according to claim 1, wherein a lower column portion that presses the temporary support column is set to the lower floor column, and an upper column portion that presses the temporary support column is set to the upper floor column. .   A plurality of the temporary columns are provided separately on the floor where the planned repair location of the pillar to be repaired, the floor on which the lower floor pillar is located, and the floor on which the upper floor pillar is located, and The method for repairing a pillar of a multi-story building according to claim 2, wherein the method is provided so that axial force can be transmitted.   The temporary strut is in a state of penetrating the floor slab of each floor across the floor where the planned repair site in the pillar to be repaired, the floor where the lower floor pillar is located, and the floor where the upper floor pillar is located. The method of repairing a pillar of a multi-story building according to claim 2, wherein the method is a series of members provided.   In order to generate the frictional force, a sandwiching steel material provided with a pair of pressing portions that sandwich the lower column portion or the upper column portion and the at least one pair of temporary support columns is provided, and spans the pair of pressing portions. The column repair method for a multi-storey building according to claim 1 or 2, wherein the temporary support column is pressed against the column to be repaired by a lower column portion and an upper column portion by a tension force of a PC steel rod to be bridged.

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