JP2015098771A - Column leg pin structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure an excellent structure performance capable of being applied to a medium-low story building, in a simple and low-cost structure.SOLUTION: A column leg pin structure 10 includes an SRC column 1 of a steel reinforcement concrete structure in which a first steel column 11 protruding toward a base beam side and a second steel column 12 jointed to an upper end of the first steel column 11 through a column joint part 14 are embedded in column concrete 13. The SRC column 1 is connected to a base beam 2 of a concrete structure. The column leg pin structure 10 is provided in which the first steel column 11 protrudes downward from a column concrete lower end surface 13a of the SRC column 1, and in a state in which a protruding portion of the first steel column 11 is embedded in the base beam 2, a clearance C is provided between the column concrete lower end surface 13a and an upper surface 2a of the base beam 2.

Description

  The present invention relates to a column base pin structure in which an SRC column and a concrete foundation beam are connected.

Conventionally, as an example of a column base joint structure that improves the seismic performance of a building, an entire collapse type system as shown in FIG. 10 that absorbs energy efficiently in the entire building by using a column base on the first floor as a pin structure is known. (For example, refer to Patent Document 1).
A column base joint structure 100 shown in FIG. 10 has a structure in which a core rebar 102 in a leg portion 101a of a wall column 101 is embedded in a foundation 103, whereby the leg portion 101a is rotatably supported by the foundation 103. It has a configuration.

JP 2012-241472 A

However, the conventional column base joint structure has the following problems.
That is, in the column base joint structure 100 shown in FIG. 10, the detail of the first floor column base that can realize an ideal pin structure is important, but as a performance required for the pin structure, it has a good rotation performance. However, it is necessary to secure the transmission performance of vertical axial force and shear force, and there is room for improvement in that respect.
And when applying the pin structure to buildings with middle and lower floors, it is difficult to achieve both rotational performance and vertical axial force and shear force transmission performance (2000kN or more). For example, installing an oil damper on the first floor There was a problem that a separate member was required, and the structure was special and complicated.

  The present invention has been made in view of the above-described problems, and provides a column base pin structure that can ensure excellent structural performance that can be applied to a low-rise building and a high-rise building with a simple and inexpensive structure. For the purpose.

  In order to achieve the above object, in the column base pin structure according to the present invention, a first steel column projecting toward the foundation beam side and a second steel frame joined to the upper end of the first steel column via a column joint portion. A steel column reinforced concrete SRC column embedded in the column concrete, and a column base pin structure in which the SRC column and the concrete foundation beam are connected, wherein the first steel column is a column concrete of the SRC column Projecting downward from the lower end surface, with the protruding portion of the first steel column embedded in the foundation beam, a clearance is provided between the lower end surface of the column concrete and the upper surface of the foundation beam. .

In the present invention, the first steel column projecting downward from the lower end surface of the column concrete of the SRC column is embedded in the concrete in the foundation beam, and a clearance is provided between the lower end surface of the column concrete and the upper surface of the foundation beam. Therefore, the embedded first steel column functions as a hinge, and a column base with a pin structure is formed. That is, in this pillar base pin structure, high axial force and shearing force transmission performance can be secured, and excellent rotational rigidity can be secured as a pin structure.
In addition, since the rotation performance as a pin is secured at the hinge part of the first steel column and the structure is excellent in deformation performance, damage to the column concrete part of the SRC column due to rotation deformation of the column base is suppressed even in large deformation areas. There is an advantage that damage on the appearance can be reduced.

And since it becomes the simple structure which does not require special members, such as using an oil damper conventionally, a workability can be improved and cost reduction can be implement | achieved.
In addition, since high axial force and shear force transmission performance can be ensured, it can be used for buildings with middle and low-rise buildings.

  In addition, since the first steel column and the second steel column are connected via the column joint portion in the SRC column, it is possible to arrange the first steel column and the second steel column having different cross-sectional sizes. It is. Therefore, the cross section of the first steel column can be designed with the required performance of the pin structure part with only the column base, and the cross section design of the second steel column (or the steel column of the floor above the second steel column) There is an advantage that it is not necessary to be restricted by the pin structure.

  Moreover, in the column base pin structure which concerns on this invention, it is preferable that the buffer material which contacts the circumference | surroundings of the embedded 1st steel column is provided in the upper end part of the foundation beam.

  By adopting such a configuration, it is possible to suppress the damage of the concrete of the foundation beam by the buffering action of the buffer material, and it is possible to secure the necessary deformability as a pin structure, that is, it is possible to reduce the rotational rigidity. .

  In the column base pin structure according to the present invention, it is preferable that the SRC column is provided with a horizontal stiffener in at least one of the first steel column and the second steel column in the column concrete of the SRC column.

  In this case, the horizontal stiffener can bear the transmission of axial force to the column concrete of the SRC column, and it becomes possible to simplify the column joint between steel columns by bolting or the like. Can be designed to The horizontal stiffener provided in the first steel column can transmit the axial force transmitted from the column concrete portion to the first steel column. In addition, when a horizontal stiffener is provided on the second steel column, even if the cross section of the steel column suddenly changes at the joint position (column joint portion) where the first steel column and the second steel column are joined, The axial force of the column concrete and the steel column can be adjusted by the horizontal stiffener of the steel column, and the plane maintenance as the SRC column can be secured.

  Moreover, in the column base pin structure which concerns on this invention, it is preferable that the horizontal stiffener is arrange | positioned in the position which is flush | planar with the lower end of the column concrete of a 1st steel column.

  In this case, since the column concrete having a small covering is not interposed below the horizontal stiffener provided at a position flush with the lower end of the column concrete, it is possible to prevent damage to the column concrete lower end surface.

  Moreover, in the column base pin structure according to the present invention, it is preferable that the first steel column and the second steel column are connected to each other by bolt joint with a space in the vertical direction.

  In this case, the axial force and the column shear force borne by the second steel column can be transmitted to the first steel column, and the transmission performance can be improved.

  Further, in the column base pin structure according to the present invention, in a portion embedded in the foundation beam from the column concrete of the first steel column, or in a clearance portion between the bottom surface of the column concrete and the upper surface of the foundation beam The web of the first steel column is preferably reinforced with a vertical stiffener.

  Further, in the column base pin structure according to the present invention, the flanges on both sides of the first steel column are closed by welding with vertical stiffeners in the portion of the first steel column embedded from the column concrete to the foundation beam. It is preferable that the inside of the closed cross section of the clearance portion between the lower end surface of the column concrete and the upper surface of the foundation beam is filled with concrete.

  In these cases, a larger vertical axial force and column shear force can be borne in the clearance between the lower end surface of the column concrete for the first steel column and the upper surface of the foundation beam. Can be improved.

  According to the column base pin structure of the present invention, there is an effect that it is possible to ensure excellent structural performance that can be applied to a low-rise building and a high-rise building with a simple and inexpensive structure.

It is an elevation view which shows the structure of the column base pin structure by embodiment of this invention. It is AA sectional view taken on the line shown in FIG. 1, Comprising: It is a figure which shows the state embedded in the foundation beam of the 1st steel column. FIG. 2 is a cross-sectional view taken along line B-B shown in FIG. 1 and is a diagram of a portion where a first steel column portion of an SRC column is disposed. It is an elevational view showing the configuration of the column base pin structure according to the first modification of the embodiment of the present invention, and shows the web of the first steel column in the clearance portion between the column concrete lower end surface and the upper surface of the foundation beam. It is the figure which reinforced. It is the DD sectional view taken on the line shown in FIG. 4, Comprising: It is a figure which shows the state embedded in the foundation beam of the 1st steel column. It is the EE sectional view taken on the line shown in FIG. 4, Comprising: It is a figure of the part by which the 1st steel column part of a SRC pillar is arrange | positioned. It is an elevation which shows the structure of the column base pin structure by the 2nd modification of embodiment of this invention, and the flange of the both sides of a 1st steel column is weld-joined with a vertical stiffener to make a closed cross section, and column concrete lower end surface It is the figure which filled concrete in the inside of the closed cross section of the clearance part between the upper surface of a foundation beam. It is the FF sectional view taken on the line shown in FIG. 7, Comprising: It is a figure which shows the state embedded in the foundation beam of the 1st steel column. It is the GG sectional view taken on the line shown in FIG. 7, Comprising: It is a figure of the part by which the 1st steel column part of an SRC pillar is arrange | positioned. It is a figure which shows an example of the conventional column base joining structure.

  Hereinafter, column base pin structures according to embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a column base pin structure 10 according to the present embodiment is a structure that improves the seismic performance of a building, and is a steel reinforced concrete column (hereinafter referred to as “SRC column 1”) and its SRC. This is a joint structure with a reinforced concrete foundation beam 2 which is embedded and fixed at the bottom of the column 1.

The SRC column 1 includes a first steel column 11 projecting toward the foundation beam 2 side, a second steel column 12 joined to the upper end 11c of the first steel column 11 via a column joint portion 14, a main bar 15A, A bar arrangement 15B, an upper half portion of the first steel column 11, and a column concrete 13 in which the second steel column 12 is embedded are schematically configured.
Here, in FIG. 1, the 1st steel column 11 by this Embodiment shows the steel 0 node in a building, and the 2nd steel column 12 has shown the steel 1 node.

The SRC column 1 has a square shape in a cross-sectional view, and a first steel column 11 and a second steel column 12 made of H-section steel are arranged along the central axis. The first steel column 11 has a larger cross-sectional shape than the second steel column 12. The first steel column 11 and the second steel column 12 are connected to each other by bolting the webs 11a and 12a with a predetermined distance S in the vertical direction.
In the column joint portion 14, a web 12a at the lower end of the second steel column 12 and a web 11a on the upper end 11c side of the first steel column 11 are sandwiched by a pair of sandwich plates 14a, and bolts 14b are provided in the thickness direction thereof. It is configured to be inserted and joined.

Moreover, as shown in FIG.1 and FIG.2, the horizontal stiffener 16 is arrange | positioned at the SRC pillar 1 in the 1st steel pillar 11 and the 2nd steel pillar 12 in the column concrete 13. As shown in FIG.
In FIG. 1, the first steel column 11 is provided with two horizontal stiffeners 16 (16A, 16B), and a first horizontal stiffener 16A disposed at a position flush with the column concrete lower end surface 13a; A second horizontal stiffener 16B disposed between the first horizontal stiffener 16A and the column joint portion 14; Further, a third horizontal stiffener 16 </ b> C is disposed on the second steel column 12 above the column joint portion 14. The horizontal stiffener 16 is arranged so as to block the space between the web 11a (12a) and the flange 11b (12b) of the first steel column 11 (second steel column 12) in the cross-sectional view of FIG.

  When two or more horizontal stiffeners 16 are provided as in the first steel column 11, the separation between the horizontal stiffeners 16 </ b> A and 16 </ b> B is set to 1.5 times or more of the column formation of the first steel column 11. Thus, the stress transmission path of the column concrete 13 can be secured, which is effective.

  As shown in FIG. 1, the first steel column 11 protrudes downward from the column concrete lower end surface 13 a of the SRC column 1, and the protruding portion of the first steel column 11 is embedded in the foundation beam 2. A certain clearance C is provided between the concrete lower end surface 13 a and the upper surface 2 a of the foundation beam 2.

The foundation beam 2 is provided with a cushioning material 21 that is located on the upper surface 2 a and that contacts the periphery of the embedded first steel column 11. As shown in FIG. 3, the buffer material 21 is provided along the peripheral surface of the H-section steel of the first steel column 11.
As the buffer material 21, for example, a foamable resin such as “Styrofoam” (registered trademark, manufactured by Dow Chemical Co., Ltd.) can be suitably used.

Next, the effect | action of the column base pin structure 10 mentioned above is demonstrated in detail based on drawing.
In the present embodiment, as shown in FIG. 1, a first steel column 11 protruding downward from a column concrete lower end surface 13a of the SRC column 1 is embedded in the concrete in the foundation beam 2, and further the column concrete lower end surface. Since the clearance C is provided between 13a and the upper surface 2a of the foundation beam 2, the embedded first steel column 11 functions as a hinge, and a column base having a pin structure is formed.
That is, in this pillar base pin structure 10, high axial force and shearing force transmission performance can be secured, and excellent rotational rigidity can be secured as a pin structure.

  Moreover, since the rotation performance as a pin is secured at the hinge portion of the first steel column 11 and the structure is excellent in deformation performance, the column concrete 13 portion of the SRC column 1 accompanying the rotation deformation of the column base even in a large deformation region. There is an advantage that damage can be suppressed and damage on appearance can be reduced.

And since it becomes the simple structure which does not require special members, such as using an oil damper conventionally, a workability can be improved and cost reduction can be implement | achieved.
In addition, since high axial force and shear force transmission performance can be ensured, it can be used for buildings with middle and low-rise buildings.

  And since the 1st steel column 11 and the 2nd steel column 12 are connected via the column joint part 14 in the SRC column 1, the 1st steel column 11 from which the magnitude | size of a cross section differs like this Embodiment. And the second steel column 12 can be arranged. Therefore, the cross section of the first steel column 11 can be designed with the necessary performance of the pin structure portion only of the column base, and the cross section of the second steel column 12 (or the steel column of the second steel column 12 or higher floor). There is an advantage that the design does not need to be restricted by the pin structure portion.

  Moreover, in this Embodiment, since the buffer material 21 which contacts the circumference | surroundings of the 1st steel column 11 is provided in the upper end part of the foundation beam 2, the damage of the concrete of the foundation beam 2 by the buffering effect of the buffer material 21 is provided. In addition, it is possible to secure the deformation capability necessary for the pin structure, that is, to reduce the rotational rigidity.

Further, in the case of the present embodiment, the horizontal stiffener 16 can bear the axial force transmission to the column concrete 13 of the SRC column 1, and the column joint portion 14 between the steel columns 11, 12 by bolting or the like is simplified. The column joint portion 14 can be rationally designed.
The horizontal stiffener 16 (16A, 16B) provided in the first steel column 11 can transmit the axial force transmitted from the column concrete 13 portion to the first steel column 11. Further, when the horizontal stiffener 16C is provided on the second steel column 12, the cross section of the steel columns 11 and 12 changes suddenly at the joint position (column joint portion 14) where the first steel column 11 and the second steel column 12 are joined. Even if it is a case, the axial force of column concrete 13 and a steel column can be adjusted with horizontal stiffener 16C of the 2nd steel column 12, and plane maintenance as SRC column 1 can be secured.

  Moreover, in this Embodiment, since column concrete with small covering does not intervene below the horizontal stiffener 16 provided in the position which becomes flush with the column concrete lower end surface 13a, it prevents that the column concrete lower end surface 13a is damaged. be able to.

  In addition, since the first steel column 11 and the second steel column 12 are connected to each other by bolt joint with an interval S therebetween in the vertical direction, the axial force and the column shear force that bear the second steel column 12 are the first. It can be transmitted to the steel column 11, and the transmission performance can be improved.

  As described above, the column base pin structure according to the present embodiment has an effect that it is possible to ensure excellent structural performance that can be applied to middle- and low-rise buildings with a simple and inexpensive structure.

  As mentioned above, although embodiment of the column base pin structure by this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably.

For example, the column base pin structure 10 according to the first modification shown in FIGS. 4 to 6 has both sides of the web 11a of the first steel column 11 in the portion embedded in the foundation beam 2 from the column concrete 13 of the first steel column 11. The vertical stiffener 17A is reinforced by welding. The vertical stiffener 17A has its surface direction orthogonal to the surface direction of the first steel column 11, and the extending direction is arranged along the vertical direction. Thereby, since a larger vertical axial force can be transmitted, the seismic performance can be improved even in a high-rise building.
The vertical stiffener includes not only a flat plate-like member as in the first modified example but also a member in which a long member such as a T-shaped steel is provided in the vertical direction along the web 11a of the first steel column 11.

  Further, the column base pin structure 10 according to the second modification shown in FIGS. 7 to 9 includes a pair of flanges 11b of the first steel column 11 in a portion embedded from the column concrete of the first steel column 11 into the foundation beam 2. 11b are welded and joined to each other with a vertical stiffener 17B to form a closed cross section, and the concrete 18 is also filled inside the closed cross section of the clearance portion between the column concrete lower end surface 13a and the upper surface 2a of the foundation beam 2. It has been configured. Thereby, since a larger vertical axial force can be transmitted, the seismic performance can be improved even in a high-rise building.

  Moreover, in this Embodiment, although the buffer material 21 is arrange | positioned in the location where the 1st steel pillar 11 of the foundation beam 2 is embedded, such a buffer material 21 is also omissible. Moreover, in this Embodiment, although the shock absorbing material 21 is provided along the perimeter of the 1st steel column 11 which consists of H-section steel, it is good also as a partial range instead of a perimeter.

  Moreover, in this Embodiment, although the horizontal stiffener 16 (16A-16C) is provided in each of the steel pillars 11 and 12 of the SRC pillar 1, this horizontal stiffener 16 can also be abbreviate | omitted, an attachment position, Configurations such as quantity and thickness can be changed as appropriate.

  Furthermore, in this embodiment, the column joint portion 14 is a bolt joint, and a space S is provided between the steel columns 11 and 12, but not limited to this, the upper end of the first steel column 11 and the first It is also possible to use a metal touch at the lower end of the two steel column 12. In this case, the metal touch surface is processed so as to be in close contact by cutting or the like, and transmission by metal touch is, for example, up to 1/4 of the axial force according to the steel structure standard (edited by the Architectural Institute of Japan).

  Further, in the present embodiment, the SRC column 1 has a square shape in a cross-sectional view, and the first steel column 11 and the second steel column 12 made of H-shaped steel are arranged along the central axis. Without being limited thereto, the SRC pillar 1 may be rectangular. In this case, it is effective from the viewpoint of structural performance that the strong axis direction of the first steel column 11 and the second steel column 12 is the short side direction of the SRC column 1.

  In addition, it is possible to appropriately replace the components in the above-described embodiments with known components without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 SRC pillar 2 Foundation beam 10 Column base pin structure 11 1st steel pillar 11a Web 11b Flange 12 2nd steel pillar 13 Column concrete 13a Concrete lower end surface 14 Column joint part 16, 16A, 16B, 16C Horizontal stiffener 17A, 17B Vertical stiffener 18 Concrete 21 Buffer material C Clearance S Clearance

Claims (7)

A steel-framed reinforced concrete SRC column in which a first steel column projecting toward the foundation beam and a second steel column joined to the upper end of the first steel column via a column joint are embedded in the column concrete A column base pin structure in which the SRC column and a concrete foundation beam are connected,
The first steel column protrudes downward from the column concrete lower end surface of the SRC column, and the projecting portion of the first steel column is embedded in the foundation beam, and the column concrete lower end surface and the foundation beam A column base pin structure characterized in that a clearance is provided between the top surface and the top surface.   2. The column base pin structure according to claim 1, wherein a cushioning material that contacts the periphery of the embedded first steel column is provided at an upper end portion of the foundation beam. 3.   The horizontal stiffener is arrange | positioned by the said SRC column at least one of the said 1st steel column and the 2nd steel column in the column concrete of this SRC column, The Claim 1 or 2 characterized by the above-mentioned. Column base pin structure.   4. The column base pin structure according to claim 3, wherein the horizontal stiffener is disposed at a position flush with a lower end of the column concrete of the first steel column.   5. The column base pin structure according to claim 1, wherein the first steel column and the second steel column are connected to each other by bolt joint with a space in the vertical direction.   In a portion embedded in the foundation beam from the column concrete of the first steel column, or in a clearance portion between the bottom surface of the column concrete and the upper surface of the foundation beam, the web of the first steel column is a vertical stiffener. 6. The column base pin structure according to claim 1, wherein the column base pin structure is reinforced.   In the portion of the first steel column embedded in the foundation beam from the column concrete, the flanges on both sides of the first steel column are welded and joined with vertical stiffeners to form a closed cross section, and the lower end surface of the column concrete and the 6. The column base pin structure according to claim 1, wherein concrete is filled in the closed cross section of a clearance portion between the upper surface of the foundation beam.

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