JP6710042B2 - Steel column and pile joint structure - Google Patents

Description

The present invention relates to, for example, a joint structure between a steel column and a pile having a reinforced concrete pile head.

Conventionally, it has been proposed to provide a connecting member (temporary support member) between the steel column and the pile as a joint structure between the steel column and the pile (see Patent Document 1).
In Patent Document 1, the upper end of the temporary support member is bolted to the steel column, and the lower end of the temporary support member is bolted to a joint plate welded to the pile head. In addition, a foundation footing is provided from below the pile head surface to above the lower end surface of the steel column, and the vertical streaks that make up the foundation footing are densely arranged from below the pile head surface to above the lower end surface of the steel column. It is arranged.

Patent Document 2 discloses that an anchor bolt connected to a fixing plate is driven into the inside of a column base concrete to secure pull-out proof strength of the anchor bolt.

JP2012-57430A Japanese Patent No. 4575019

In Patent Document 1, when the pulling force acts on the steel column, the pulling force is transmitted from the steel column to the vertical bar that constitutes the concrete foundation footing, and is transmitted to the pile through the vertical bar. It Therefore, a high tensile stress is generated in the vertical streaks, which may cause cracks along the vertical streaks. Further, in a steel frame column to which a high pulling force is applied, it is necessary to arrange longitudinal and lateral reinforcements constituting the basic footing at a high density, which tends to increase the size of the basic footing.

Further, in Patent Document 1, a temporary support material is installed on the upper end surface of the pile, a plate is provided on the upper end surface of the temporary support material, and the steel column is fixed on the plate. Therefore, in order to determine the installation position and installation adjustment of the steel column, it is necessary to insert a height adjustment material between the steel column and the plate for adjustment, and to secure the installation height positioning and installation accuracy. It took a lot of time.

In Patent Document 2, in order to fix the steel column, a column base concrete having a wide portion that exceeds the steel column is required, and the degree of freedom in design is limited when planning the arrangement of the steel columns.

INDUSTRIAL APPLICABILITY The present invention provides a joint portion structure between a steel column and a pile, which facilitates positioning of a built-up position of the steel column and has excellent toughness by smoothly transmitting a force generated in the upper structure to the pile. The task is to do.

A first invention is a structure of a joint portion between a steel column (for example, steel columns 20 and 20A described below) and a pile (for example, a pile 10 described below), and a plate (for example, an upper portion described below) at an upper end portion. A connecting member made of steel (for example, connecting members 30, 30A, 30B described later) having a plate 32) is provided, and the plate of the connecting member is joined to the lower end portion of the steel column, and the lower end of the connecting member is provided. The part is embedded in a concrete body inside the pile.

According to the first aspect of the invention, the connecting member is provided that is joined to the pillar and is fixed in the pile body. Therefore, the height position of the pillar can be adjusted by adjusting the embedded length of the connecting member. Further, since the connecting member is arranged between the steel pillar and the pile, and the connecting member is joined to the steel pillar and is fixed in the pile body, the tensile force generated in the steel connecting member However, since it is transmitted to the vertical reinforcing bars that make up the pile, the seismic performance of the column can be sufficiently secured. Unlike in the prior art, it is not necessary to transmit the pulling force between the steel columns and the piles by the vertical streaks constituting the foundation footing, and it is not necessary to arrange the vertical streaks of the foundation footing closely. Therefore, the basic footing can be downsized. Further, it is easy to position the built-up position of the steel column, and it is possible to smoothly transmit the force generated in the upper structure to the pile and exhibit excellent toughness.

Further, since the lower end portion of the connecting member is embedded in the concrete in the pile body, the lower end portion of the connecting member is restrained by the hardened concrete and is firmly joined to the pile by the adhering action of the concrete.

A second invention is characterized in that a stud (for example, a stud 33 described later) is provided on an outer peripheral surface of a portion of the connecting member embedded in the concrete body.

According to the second invention, since the stud is planted in the portion of the connecting member embedded in the concrete body, the connecting member is fixed to the pile body through the stud, and the connecting member is firmly fixed to the pile body. You can
Further, the stud can be attached to the pile body by providing the stud on the flange and/or the web according to the magnitude of the bending moment, the shearing force, and the axial force acting on the steel column.

A third invention is that a stud (for example, studs 23 and 33 described later) is provided on the outer peripheral surface of the lower end of the steel column and/or the outer peripheral surface of the connecting member, and the stud is made of the steel. It is characterized in that it is embedded in a concrete body (for example, a foundation footing 40 described later) that covers the outer peripheral surface of the lower end of the pillar.

According to the third invention, since the stud is provided on the outer peripheral surface of the lower end portion of the steel column and/or the outer peripheral surface of the connecting member, the connecting member is fixed to the concrete body such as the foundation footing through the stud, The connecting member can be firmly fixed to the foundation footing.

According to the present invention, the concrete body covering the outer peripheral surface of the lower end portion of the steel column has the lower end surface located below the upper end surface of the pile, and the upper end surface located above the lower end surface of the steel column. It is preferably located at.

ADVANTAGE OF THE INVENTION According to this invention, it is easy to position the built-in position of a steel column, and the joint part of a steel column and a pile which has excellent toughness by transmitting the force which generate|occur|produces in an upper structure smoothly to a pile. Can provide the structure of.

It is a longitudinal cross-sectional view of the joint structure between the pillar and the pile according to the first embodiment of the present invention. It is the AA sectional view and BB sectional view of FIG. It is a longitudinal cross-sectional view of the joint part structure of the pillar and the pile which concerns on the reference example of this invention. It is CC sectional view and DD sectional view of FIG. It is a longitudinal cross-sectional view of the joint part structure of the pillar and the pile which concerns on 2nd Embodiment of this invention. FIG. 6 is a sectional view taken along line EE of FIG. 5. It is a longitudinal cross-sectional view of the joint part structure of the pillar and the pile which concerns on the 1st modification of this invention. It is a longitudinal cross-sectional view and FF sectional drawing of the joint part structure of the pillar and the pile which concern on the 2nd modification of this invention. It is a longitudinal cross-sectional view and GG sectional drawing of the joint part structure of the pillar and the pile which concern on the 2nd modification of this invention.

The present inventor inserts a connecting member joined to a lower end of a steel column into a hollow portion of a pile head as a joint structure for connecting a steel column and a pile body, and consolidates the connecting member with concrete. Therefore, paying attention to the fact that the connecting member functions as a height adjusting member for the steel column, and also as a pull-out resistance material that connects the steel column and the pile body, the joint structure of the steel column and the pile body is considered. Invented.
Specifically, the connecting member that connects the steel column and the pile is divided into two parts, that is, an H-shaped steel material (first embodiment) that is joined to the lower end of the steel column and has studs implanted therein. It is a configuration including a plurality of grooved steel materials (second embodiment) joined to the lower part of the pillar and a plate fixed to the upper end surface of the pile (third embodiment).

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the embodiments, the same constituents will be given the same reference numeral, and the description thereof will be omitted or simplified.
[First Embodiment]
FIG. 1 is a vertical sectional view of a joint structure 1 between a pillar and a pile according to the first embodiment of the present invention. 2A is a sectional view taken along the line AA of FIG. 1, and FIG. 2B is a sectional view taken along the line BB of FIG.
The joint structure 1 of a pillar and a pile is a pile 10 constructed in the ground, a steel pillar 20, and a steel connecting member that is joined to the lower end of the steel pillar 20 and is fixed to the pile 10. 30 is provided.
On the upper part of the pile 10, a base footing 40 into which the lower end of the steel column 20 and the connecting member 30 are driven is constructed.

The pile 10 is a ready-made cylindrical RC pile (centrifugal-molded reinforced concrete pile), and is a hollow pile in which a hollow portion 11 is formed.

The steel column 20 includes a column main body 21 that is an H-shaped steel, a lower plate 22 provided at the lower end of the column main body 21, and a stud 23 that is planted on the outer peripheral surface of the lower end of the column main body 21. Prepare

The connecting member 30 includes a vertical portion 31 made of H-shaped steel extending substantially vertically, and a substantially horizontal plate-shaped upper plate 32 provided at an upper end of the vertical portion 31.
The lower plate 22 of the steel column 20 is joined to the upper plate 32 with bolts 24. As a result, the upper plate 32 of the connecting member 30 is joined to the lower plate 22 at the lower end of the steel column 20.

The lower end of the vertical portion 31 is inserted into the hollow portion 11 of the pile 10, and the filled concrete is cast into the upper end of the hollow portion 11. As a result, the lower end portion of the connecting member 30 is embedded in the hardened concrete body 12 of the hollow portion 11.
Studs 33 are planted on the upper flange of the vertical portion 31 and the outer peripheral surface of the web. However, if the external load carried by the steel column is small, the stud may be provided on only one of the flange and the web of the vertical portion.

The vertical portion 31 has a smaller horizontal cross-sectional area than the column main body 21 of the steel column 20. The vertical portion 31 may have a size that can secure the fixing strength of the vertical portion 31 to the pile 10 and can sufficiently resist the tensile force between the pile 10 and the steel column 20.

The portion of the column main body 21 where the stud 23 is provided and the portion of the vertical portion 31 where the stud 33 is provided are embedded in the foundation footing 40.
That is, the foundation footing 40 is a concrete body that covers the lower end portion of the steel column 20 and the outer peripheral surface of the connecting member 30, the lower end surface is located below the upper end surface of the pile 10, and the upper end surface is the steel column. It is located above the lower end surface of 20.

According to this embodiment, there are the following effects.
(1) The connecting member 30 joined to the steel column 20 and fixed to the pile 10 is provided. Therefore, the height position of the steel column 20 can be adjusted by adjusting the embedded length of the connecting member 30. Further, since the connecting member 30 is joined to the steel column 20 and is fixed to the pile 10, the tensile force generated in the connecting member 30 is transmitted to the vertical reinforcing bars constituting the pile 10. The seismic performance of 20 can be sufficiently secured. Therefore, the foundation footing 40 can be miniaturized, the positioning of the steel column 20 can be easily positioned, and the force generated in the superstructure can be smoothly transmitted to the pile 10 to exhibit excellent toughness. it can.

(2) Since the studs 23 and 33 are planted on the outer peripheral surface of the lower end portion of the steel column 20 and the outer peripheral surface of the vertical portion 31 of the connecting member 30, the steel column 20 and the connecting member 30 are studs 23 and 33. It is firmly fixed to the concrete body of the foundation footing 40 via.

(3) By joining the steel column 20 and the connecting member 30 via the upper plate 32, even if the steel column 20 and the vertical portion 31 of the connecting member 30 have different cross-sectional shapes, they can be reliably joined. . Further, by joining the steel column 20 to the substantially horizontal upper plate 32, the vertical accuracy of the steel column 20 can be secured.

(4) Since the lower end portion of the connecting member 30 is driven into the concrete body 12 filled in the cylindrical RC pile 10, the concrete body 12 is locked by the wall surface of the pile 10, and the friction and the concrete body caused by the concrete Since it is restrained by the adhesive action of 12, it is firmly joined to the pile 10.

[ Reference example ]
FIG. 3 is a vertical sectional view of a joint structure 1A between a pillar and a pile according to a reference example of the present invention. 4A is a sectional view taken along the line CC of FIG. 3, and FIG. 4B is a sectional view taken along the line DD of FIG.
In this reference example , the steel column 20A is vertically divided into two parts, and includes a column lower portion 50 and a column upper portion 51 provided on the column lower portion 50.

The column lower part 50 includes a column body 52 which is a rectangular steel tube, a lower plate 53 which is provided at a lower end of the column body 52, an upper plate 54 which is a plate material provided at an upper end of the column body 52, and a column body 52. And a stud 55 planted on the outer peripheral side surface.
The lower plate 53 of the column lower portion 50 is joined to the upper plate 32 of the connecting member 30 with the bolt 24.

The column upper portion 51 includes a column main body 56 which is a rectangular steel pipe, and a lower plate 57 provided at the lower end of the column main body 56. The lower plate 57 of the column upper portion 51 is bolted to the upper plate 54 of the column lower portion 50.

The vertical portion 31 of the connecting member 30A is formed by arranging a pair of grooved steels back to back and at a predetermined distance.

According to this reference example , in addition to the effects (1) to (4) described above, the following effects are obtained.
(5) Since the steel column 20A is vertically divided into two, the vertical accuracy can be easily managed when the steel column 20A is built in the pile 10.

[ Second Embodiment]
FIG. 5 is a vertical cross-sectional view of a joint structure 1B between a pillar and a pile according to the second embodiment of the present invention. FIG. 6 is a sectional view taken along line EE of FIG.
In the present embodiment, the fixing member 60 is attached to the connecting member 30B. The fixing member 60 includes an annular plate 61 fixed to the upper end surface of the pile 10 and a fixing portion 62 that extends downward from the plate 61 and is embedded in the concrete body 12 of the pile 10.
A disc-shaped lower plate 34 is attached to the lower end of the vertical portion 31 of the connecting member 30B. The lower plate 34 is joined to the plate 61 of the fixing member 60 with bolts 63.

According to this embodiment, there are the same effects as the above (1) to (4).

It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within the scope of achieving the object of the present invention are included in the present invention.
For example, although the ready-made RC pile is used as the pile 10 in each of the above-described embodiments, the present invention is not limited to this. For example, a PC pile (prestressed concrete pile), a PHC pile (high-strength prestressed concrete pile), and a PRC pile ( High-strength prestressed reinforced concrete pile) and SC pile (concrete pile with outer shell steel pipe) may be used.

Further, in each of the above-described embodiments, the column main body 21 of the steel column 20 is H-shaped steel and the column main bodies 52 and 56 of the steel column 20A are square steel pipes, but the present invention is not limited to this, and a circular steel pipe or the like is used. May be. Further, concrete may be filled in a column body that is a rectangular steel pipe or a circular steel pipe, and the steel column may be a CFT (Concrete Filled Steel Tube) column.

The pile of the present invention may be a cast-in-place concrete pile constructed at a construction site, instead of a ready-made concrete pile. In the case of cast-in-place concrete piles, a hollow part is often not provided in the pile head, and by driving the connecting material near the center of the pile body, it is possible to connect the steel pillar and the pile with the connecting material.

In addition, in each of the above-described embodiments, the lower plate 22 of the steel column 20 and the upper plate 32 of the connecting member 30 are connected to each other, but the present invention is not limited to this. A pair of chevron steel materials may be attached to the lower surface of the plate 22, and the chevron steel materials and the lower plate 22 of the steel column 20 may be connected. This angle steel material is a connecting member between the steel column 20 and the connecting member 30 and also serves as a height adjusting member.

Further, as shown in FIG. 7, the studs 33 may be planted also on the outer peripheral surface of the flange and the web of the portion of the vertical portion 31 of the connecting member 30 which is embedded in the concrete body 12. According to this configuration, the vertical portion 31 of the connecting member 30 including the stud 33 is firmly joined to the pile 10 by the adhering action of the hollow portion 11 of the pile 10 with the concrete body 12. The bending moment, shearing force, and axial force transmitted from the vertical portion 31 of the connecting member 30 to the concrete body 12 are applied to the pile 10 by the friction resistance mechanism between the concrete body 12 of the pile 10 and the inner peripheral surface of the pile 10. Transmitted. Therefore, the concrete body 12 of the pile 10 has a height sufficient to transmit the internal stress component to the pile 10 by frictional resistance.

Further, as shown in FIG. 8, by mounting a positioning member 35 extending in the horizontal direction at a predetermined height position below the connecting member 30, and mounting the positioning member 35 on the upper edge of the pile 10, The connection member 30 may be positioned in the height direction. The positioning member 35 is, for example, an angle steel member or a groove steel member, and is fixed to the connecting member 30 by welding or bolts. According to this configuration, it is possible to increase the installation accuracy in the height direction of the steel column 20 and the degree of fixation during installation.

Further, as shown in FIG. 9, a positioning member 36 extending in the horizontal direction is attached to a predetermined height position below the connecting member 30. By mounting the positioning member 36 on the upper surface of the concrete body 12, the connecting member 36 is connected. The member 30 may be positioned in the height direction. The positioning material 36 is, for example, a flat steel material, an angle steel material, or a grooved steel material. According to this configuration, it is possible to increase the installation accuracy in the height direction of the steel column 20 and the degree of fixation during installation.

1, 1A, 1B... Joint structure between pillar and pile 10... Pillar 11... Hollow part 12... Concrete body 20, 20A... Steel pillar 21... Pillar body 22... Lower plate 23... Stud 24... Bolt 30, 30A, 30B... Connecting member 31... Vertical part 32... Upper plate 33... Stud 34... Lower plate 35, 36... Positioning member 40... Foundation footing 50... Column lower part 51... Column upper part 52... Column body 53... Lower plate 54... Upper plate 55 ... Stud 56 ... Pillar body 57 ... Lower plate 60 ... Fixing member 61 ... Plate 62 ... Fixing part 63 ... Bolt

Claims (2)

A structure of a joint between a steel column and a pile, comprising a pile, a foundation footing provided on the pile, and a steel column having a lower end embedded in the foundation footing,
Wherein a lower end portion of the pile and the steel pillars are connected by a consolidated member embedded in the foundation footing,
The connecting member includes a vertical portion extending substantially vertically, and a substantially horizontal plate-shaped upper plate provided at an upper end of the vertical portion,
The upper plate is joined to the lower end of the steel column,
The lower end of the vertical portion is embedded in the concrete body inside the pile,
A joint structure between a steel column and a pile, wherein a stud is provided on an outer peripheral surface of a portion of the vertical portion which is embedded in the foundation footing . The outer peripheral surface of the embedded portion inside the concrete body before Kikui of the vertical portion, the stud is provided, and the horizontal cross-sectional area of the vertical section is smaller than the horizontal cross-sectional area of the steel pillar The joint structure between a steel column and a pile according to claim 1, wherein

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