JP2009203705A - Repairing structure of column base of steel column - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a repairing structure of a column base of a steel column, which facilitates repair of the pedestal of the steel column without using encasing concrete. <P>SOLUTION: According to the repairing structure, an L-shaped repairing member 20 formed of a fixing portion 21 and an engaging portion 22 is employed as a new anchoring means in place of a damaged anchoring means, and the fixing portion is anchored to a side surface of an individual footing 15 by anchors 16, followed by engaging the engaging portion with a base plate 2 and welding the former to the latter. In this manner the base plate is re-anchored to the individual footing in a manner capable of transmitting an axial force and shear force via the repairing member. With respect to the repairing member, the fixing portion and the engaging portion are preferably made of steel plates, and the former and the latter are combined with and welded to each other in the shape of L. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a repair structure for a column base of a steel column that is erected on a foundation.

In a relatively small and simple steel structure building, for example, as shown in FIG. 3A, the base plate 2 of the steel column 1 is simply fastened to the foundation 3 by the anchor bolts 4 in a pin joint form. In many cases, it is erected.
In such a structure, when the steel column 1 is damaged by an earthquake, the anchor bolt 4 may be pulled out or broken. As shown in FIG. 3 (b), it is common to construct the root winding concrete 5 on the column base.
This is to construct a strong RC reinforced concrete core 5 by placing the main reinforcement 6 and the strip reinforcement 7 on the column base and then placing the concrete into the column base. A large number of studs 8 are planted on the column bases in order to ensure integration with the base 5, and the main reinforcement 6 is post-placed against the foundation 3 in order to securely integrate the root-wrapped concrete 5 and the foundation 3. The anchor 9 is used for fixing.

Further, it is considered that a root-wrap type reinforcing structure shown in Patent Document 1 can be adopted as a similar repair method. As shown in FIG. 4, the outer winding steel pipe 10 is installed outside the root winding concrete 5, and the lower end portion of the outer winding steel pipe 10 is embedded in the notched portion 11 formed in the foundation 3.
Japanese Patent Laid-Open No. 10-18424

  In the conventional repair or reinforcement structure as described above, for the construction of the root winding concrete 5, the reinforcement of the main reinforcement 6 and the band reinforcement 7, the fixing of the main reinforcement 6 to the foundation 3, the installation of the formwork or the outer winding steel pipe 10 Therefore, it is not always easy to construct and requires a considerable cost and construction period.

  In any case, it is common that the steel column 1 is integrally formed with the outer wall, the inner wall, or the waist wall. Requires at least the work of dismantling the wall body formed integrally with the column base in advance, and the work of restoring the wall body after the construction of the root-wrapped concrete 5, and for that purpose bothersome labor and cost It takes a work period.

  In view of the above circumstances, an object of the present invention is to provide an effective and appropriate repair structure capable of easily repairing a column base portion of a steel column without constructing root-wrapped concrete.

  The present invention is directed to a steel column in which a column base portion is fixed by a fixing means with respect to an independent foundation and is erected in a pin-joint manner, and is replaced when the existing fixing means is damaged. A repair structure for re-fixing the column base by a new fixing means, and as a new fixing means, a fixing portion fixed by an anchor on the side surface of the independent foundation, and an upper part of the fixing portion An L-shaped repair member provided with an engagement portion that is provided and welded to the base plate of the steel column is used, and the fixing portion of the repair member is fixed to the side surface of the independent base and the engagement portion of the repair member is By welding to the base plate, the base plate is re-fixed to the independent foundation by the repair member in a state where the axial force and shearing force acting on the steel column can be transmitted to the independent foundation through the repair member. Also It is.

  As the repair member, an appropriate form can be adopted as long as it can transmit axial force and shearing force, and in particular, both the fixing portion and the engaging portion are made of steel plate material. What welded combining the fixing | fixed part and the engaging part in L shape can be employ | adopted suitably.

  According to the present invention, a repair member capable of transmitting axial force and shear force is used as a new fixing means in place of a damaged anchor bolt, and the steel plate base plate is re-fixed to an independent foundation by the repair member. A sufficient repair effect can be obtained only by an extremely simple operation without constructing the wrapping concrete. Therefore, labor and cost required for the repair can be greatly reduced.

  Particularly, the repair member is optimally welded by combining a fixed portion made of a steel plate material and an engaging portion in an L shape, and according to this, sufficient strength as a means for transmitting axial force and shear force is obtained. It can be manufactured at the lowest cost while being secured, can be made sufficiently small and lightweight, has excellent workability, and requires a minimum space for installation.

With reference to FIGS. 1-2, one Embodiment of the repair structure of this invention is described. FIG. 1 shows a state after repair, and FIG. 2 shows a state before repair of the steel column 1 to be repaired.
The steel column 1 to be repaired shown in FIG. 2 is a structure in which a base plate 2 is fixed to an independent foundation 15 by anchor bolts 4 and is erected in a pin joint form. When the anchor bolt 4 is pulled out or broken, the repair is performed.
In such a case, as described above, it is common in the past to construct the wrapping concrete on the column base, but in the case of this embodiment, the cross section of the independent foundation 15 is relative to the cross section of the steel column 1. Therefore, it is difficult to construct the root winding concrete as usual. Therefore, in this embodiment, the repair member 20 as shown in FIG. It is supposed to be repaired by using it, thereby obtaining a repair effect equivalent to or higher than that of the case of the root winding concrete.

The repair member 20 used in this embodiment is an L-shaped metal fitting made of a steel plate material, and is fixed to the side surface of the independent foundation 15 by anchors 16 (6 in 2 rows × 3 stages in the illustrated example). It consists of a fixed portion 21 and an engaging portion 22 that engages with the base plate 2 and is welded thereto.
The repair member 20 has sufficient rigidity to transmit the axial force and shearing force acting on the steel column 1 to the independent foundation 15, and the fixing portion 21 is fixed to the side surface of the independent foundation 15 and fixed by the anchor 16. In this state, the engaging portion 22 is engaged with the base plate 2 of the steel column 1 and welded thereto, so that the repair member 20 functions as a new fixing means in place of the existing anchor bolt 4 and shears as well as axial force. Power can also be borne.

Therefore, by fixing the base plate 2 to the independent base 15 using such a repair member 20, that is, instead of the damaged existing anchor bolt 4, the base plate 2 is fixed to the independent base 15 by the repair member 20. By re-fixing, it is possible to obtain a sufficient repair effect by an extremely simple operation without constructing the wrapping concrete.
In particular, since there is no need for the construction of the wrapping concrete, even if the outer wall, the inner wall, or the waist wall is integrally attached to the steel column 1, it is time consuming to disassemble and reconstruct it as before. Therefore, it is not necessary, and is therefore optimal as a repair method for the steel column 1 having a wall attached to the column base.
Of course, since the repair member 20 is a simple metal fitting made of a steel plate material, the cost of the repair member 20 is insignificant, and it is sufficient if there is a space for the size of the repair member 20 around the column base and the independent foundation 15. Therefore, it is not necessary to secure a special space to install this, and it can be applied to narrow spaces without any problems. Therefore, it is ideal as a repair method when root winding concrete cannot be constructed. Is

In addition, as the repair member 20, what welded simply the steel plate material used as the fixing | fixed part 21 and the steel plate material used as the engaging part 22 like the said embodiment is employable suitably, However, it is not restricted to it Alternatively, when a desired strength can be ensured and manufacturing is easy, a single steel plate material may be bent into an L shape.
Further, when higher strength is required, the repair member 20 is appropriately made of a section steel (for example, an angle material, a channel material, an H-shape steel, etc.) or a steel pipe material instead of the steel plate material. Can also be considered.
In any case, the repair member 20 is fixed between the steel column 1 and the independent foundation 15 with the fixing portion 21 fixed to the side surface of the independent foundation 15 by the anchor 16 and the engaging portion 22 welded to the base plate 2. As long as both axial force and shearing force can be transmitted effectively, the repair member 20 as a whole has rigidity, dimensions, shape, number of installations, installation position, and fixing type to the independent foundation 15 (number of anchors 16). And the position), the welding location for the base plate 2 and the like may be set appropriately.

  The above embodiment is applied to the case where the steel column 1 is a square steel pipe, the base plate 2 is square, and the section of the independent foundation 15 on which the steel column 1 is erected is also square. In the above embodiment, the four repair members 20 are evenly arranged around the steel column 1 in the above-described embodiment. In short, the entire base plate 2 is stably and reliably re-fixed to the independent foundation 15 by the repair members 20. In order to do so, not only the shape and dimensions of the repair member 20 are adjusted, but also the required number may be increased or decreased and the installation positions thereof may be adjusted. For example, when the steel column 1 is a circular steel pipe and the base plate 2 is also circular, the same effect can be obtained by installing at least three repair members 20 at equal intervals.

It is a figure which shows the repair structure which is embodiment of this invention. It is a figure which shows the state before repair same as the above. It is a figure which shows the repair structure by the conventional root winding concrete. It is a figure which shows the other example of the repair structure by the conventional root winding concrete.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel column 2 Base plate 15 Independent foundation 16 Anchor 20 Repair member 21 Fixed part (steel plate material)
22 Engagement part (steel plate material)

Claims (2)

Targeting steel columns that have a column base fixed to the independent foundation by a fixing means and are erected in a pin-joint manner. When the existing fixing means is damaged, a new fixing is made instead of the fixing means. A repair structure for re-fixing the column base by means,
As a new fixing means, an L-shaped part comprising a fixing part fixed to the side surface of the independent foundation by an anchor and an engaging part integrally provided on the upper part of the fixing part and welded to the base plate of the steel column. Using repair members,
By fixing the fixing portion of the repair member to the side surface of the independent base and welding the engaging portion of the repair member to the base plate, the axial force and shearing force acting on the steel column can be made independent via the repair member. A repair structure for a column base of a steel column, wherein a base plate is re-fixed to an independent foundation by the repair member in a state where it can be transmitted to the foundation. The repair structure of the column base part of the steel column according to claim 1,
The repair member is a steel column characterized in that the fixing portion and the engaging portion are both made of a steel plate material, and the fixing portion and the engaging portion are combined in an L shape and welded. Column base repair structure.

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