JP6945679B2 - Joint structure of steel columns and piles - Google Patents

Description

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

Conventionally, as a joint structure between a steel frame column and a pile, it has been proposed to provide a connecting member (temporary support member) between the steel frame 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 the joint plate welded and fixed to the pile head. In addition, foundation footing is provided from below the pile head surface to above the lower end surface of the steel column, and the vertical bars constituting the foundation footing are densely arranged from below the pile head surface to above the lower end surface of the steel column. Reinforcement is done.

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

Japanese Unexamined Patent Publication No. 2012-57430 Japanese Patent No. 4575019

In Patent Document 1, when a pulling force acts on a steel column, the pulling force is transmitted from the steel column to the vertical bars constituting the concrete foundation footing, and is transmitted to the pile via the vertical bars. NS. Therefore, a high tensile stress is generated in the vertical streaks, so that there is a possibility that cracks may occur along the vertical streaks. Further, in the steel column to which a high pulling force is applied, it is necessary to arrange the vertical and horizontal bars constituting the foundation footing at a high density, and the foundation footing tends to be large.

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 frame column is fixed on the plate. Therefore, it is necessary to insert a height adjusting material between the steel column and the plate to determine the installation position and adjust the installation of the steel column, and to ensure the positioning of the installation height and the 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 wider portion than the steel column is required, and the degree of freedom in design is limited in planning the arrangement of the steel column.

The present invention provides a joint structure between a steel column and a pile, which is easy to position the built-in position of the steel column and has excellent toughness by smoothly transmitting the force generated in the superstructure to the pile. The task is to do.

The first invention is a structure of a joint portion between a steel column (for example, steel columns 20 and 20A described later) and a pile (for example, a pile 10 described later), and a plate (for example, an upper part described later) is formed at an upper end portion. A steel connecting member having a plate 32) (for example, connecting members 30, 30A, 30B described later) is provided, and the plate of the connecting member is joined to the lower end of the steel column, and the lower end of the connecting member is joined. The portion is characterized in that it is embedded in a concrete body filled in a hollow portion of the ready-made concrete pile.
Further, the connecting member functions as a height adjusting member for the steel column by adjusting the buried length, and is fixed to the ready-made concrete pile.

According to the first invention, a connecting member that is joined to the column and fixed inside the pile is provided. Therefore, the height position of the pillar can be adjusted by adjusting the buried length of the connecting member. Further, since the connecting member is arranged between the steel column and the pile, and this connecting member is joined to the steel column and fixed inside the pile, the tensile force generated in the steel connecting member is generated. However, since it is transmitted to the vertical reinforcing bars that make up the pile, the seismic performance of the columns can be sufficiently ensured. Unlike the conventional method, it is not necessary to transmit the pulling force between the steel column and the pile by the vertical bars constituting the foundation footing, and it is not necessary to densely arrange the vertical bars of the foundation footing. Therefore, the basic footing can be miniaturized. In addition, it is easy to position the built-in position of the steel column, and the force generated in the superstructure can be smoothly transmitted to the pile to exhibit excellent toughness.

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

The second invention is characterized in that a stud (for example, a stud 33 described later) is provided on the 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 via the stud, and the connecting member is firmly fixed to the pile body. Can be done.
Further, the studs can be provided 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, so that the connecting member can be fixed to the pile body.

In the third invention, studs (for example, studs 23 and 33 described later) are 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, 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 portion of the pillar.

According to the third invention, since the studs are 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 via the stud. The connecting member can be firmly fixed to the foundation footing.

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

According to the present invention, the joint portion between the steel column and the pile has excellent toughness by easily positioning the built-in position of the steel column and smoothly transmitting the force generated in the superstructure to the pile. Structure can be provided.

It is a vertical sectional view of the joint structure of a column and a pile which concerns on 1st Embodiment of this invention. FIG. 1 is a cross-sectional view taken along the line AA and a cross-sectional view taken along the line BB of FIG. It is a vertical sectional view of the joint structure of a column and a pile which concerns on 2nd Embodiment of this invention. FIG. 3 is a cross-sectional view taken along the line CC and a cross-sectional view taken along the line DD of FIG. It is a vertical sectional view of the joint structure of a column and a pile which concerns on 3rd Embodiment of this invention. FIG. 5 is a cross-sectional view taken along the line EE of FIG. It is a vertical cross-sectional view of the joint structure of a column and a pile which concerns on the 1st modification of this invention. It is a vertical sectional view and FF sectional view of the joint structure of a column and a pile which concerns on the 2nd modification of this invention. It is a vertical sectional view and GG sectional view of the joint structure of a column and a pile which concerns on the 2nd modification of this invention.

The present inventor inserts a connecting member joined to the lower end of the steel column into the hollow portion of the pile head as a joint structure for connecting the steel column and the pile body, and solidifies the connecting member with concrete. By 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 for connecting the steel column and the pile body, the joint structure between the steel column and the pile body is constructed. I came to invent it.
Specifically, the connecting member that connects the steel column and the pile is an H-shaped steel material (first embodiment) that is joined to the lower end of the steel column and has studs planted, and the steel column is divided into two parts. It is a configuration including a plurality of grooved steel materials (second embodiment) joined to the lower part of the column 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 description of the following embodiments, the same components will be designated by the same reference numerals, and the description thereof will be omitted or simplified.
[First Embodiment]
FIG. 1 is a vertical cross-sectional view of a joint structure 1 between a column and a pile according to the first embodiment of the present invention. FIG. 2A is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 2B is a cross-sectional view taken along the line BB of FIG.
The joint structure 1 between the pillar and the pile is a steel connecting member that is joined to the pile 10 constructed in the ground, the steel pillar 20, and the lower end of the steel pillar 20 and fixed to the pile 10. 30 and.
At the upper part of the pile 10, a lower end portion of the steel column 20 and a foundation footing 40 into which the connecting member 30 is driven are constructed.

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

The steel column 20 includes a column body 21 made of H-shaped steel, a lower plate 22 provided at the lower end of the column body 21, and a stud 23 planted on the outer peripheral surface of the lower end of the column body 21. Be prepared.

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 the 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 filled concrete is poured into the upper end of the hollow portion 11. As a result, the lower end 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 borne by the steel column is small, studs may be provided on only one of the flange and the web in the vertical portion.

The vertical portion 31 has a smaller horizontal cross-sectional area than the column 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 sufficiently resist the tensile force between the pile 10 and the steel column 20.

The portion of the column body 21 provided with the stud 23 and the portion provided with the stud 33 above the vertical portion 31 are embedded in the foundation footing 40.
That is, the foundation footing 40 is a concrete body that covers the lower end 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) A connecting member 30 which is 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 buried length of the connecting member 30. Further, since the connecting member 30 is joined to the steel column 20 and 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, so that the steel column Sufficient seismic performance of 20 can be secured. Therefore, the foundation footing 40 can be miniaturized, the built-in position of the steel column 20 can be easily positioned, and the force generated in the superstructure is smoothly transmitted to the pile 10 to exhibit excellent toughness. can.

(2) Since the studs 23 and 33 were 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 the studs 23 and 33. It is firmly fixed to the concrete body of the foundation footing 40 through.

(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 ensured.

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

[Second Embodiment]
FIG. 3 is a vertical sectional view of a joint structure 1A between a column and a pile according to a second embodiment of the present invention. 4 (a) is a cross-sectional view taken along the line CC of FIG. 3, and FIG. 4 (b) is a cross-sectional view taken along the line DD of FIG.
In the present embodiment, the steel column 20A is divided into upper and lower parts, and includes a column lower portion 50 and a column upper portion 51 provided on the column lower portion 50.

The column lower portion 50 includes a column body 52 which is a square steel pipe, a lower plate 53 provided at the lower end of the column body 52, an upper plate 54 which is a plate material provided at the upper end of the column body 52, and a column body 52. It is provided with 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 bolts 24.

The column upper portion 51 includes a column main body 56 which is a square 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 51 is bolted to the upper plate 54 of the column lower 50.

Further, the vertical portion 31 of the connecting member 30A is configured by arranging a pair of channel steels back to back and at predetermined intervals.

According to this embodiment, in addition to the above-mentioned effects (1) to (4), there are the following effects.
(5) Since the steel column 20A is divided into upper and lower parts, the vertical accuracy can be easily controlled when the steel column 20A is built in the pile 10.

[Third Embodiment]
FIG. 5 is a vertical sectional view of a joint structure 1B between a column and a pile according to a third embodiment of the present invention. FIG. 6 is a cross-sectional view taken along the 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 extending downward from the plate 61 and embedded in the concrete body 12 of the pile 10.
A disk-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 a bolt 63.

According to this embodiment, there is the same effect as the above-mentioned (1) to (4).

The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the range in which the object of the present invention can be achieved are included in the present invention.
For example, in each of the above-described embodiments, a ready-made RC pile is used as the pile 10, but the pile is not limited to this, and 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 piles) and SC piles (concrete piles with outer shell steel pipes) may be used.

Further, in each of the above-described embodiments, the column body 21 of the steel column 20 is H-shaped steel, and the column 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. You may. Further, the steel column may be made into a CFT (Concrete Filled Steel Tube) column by filling the column body, which is a square steel pipe or a circular steel pipe, with concrete.

Further, 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 portion is often not provided at the pile head, and by driving a connecting material near the center of the pile body, the steel column and the pile can be connected by the connecting material.

Further, 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, but the present invention is not limited to this, and the lower portion of the steel column 20 is attached to the upper end of the connecting member 30. A pair of angle steel materials may be attached to the lower surface of the plate 22, and the angle steel materials and the lower plate 22 of the steel column 20 may be connected to each other. 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 stud 33 may be planted on the flange of the portion of the vertical portion 31 of the connecting member 30 embedded in the concrete body 12 and the outer peripheral surface of the web. According to this configuration, the vertical portion 31 of the connecting member 30 provided with the stud 33 is firmly joined to the pile 10 by the adhesive action of the hollow portion 11 of the pile 10 with the concrete body 12. Further, the bending moment, the shearing force and the axial force transmitted from the vertical portion 31 of the connecting member 30 to the concrete body 12 are transferred to the pile 10 by the frictional resistance mechanism between the concrete body 12 of the pile 10 and the inner peripheral surface of the pile 10. Be transmitted. Therefore, the concrete body 12 of the pile 10 has a sufficient height to transmit the internal stress to the pile 10 by the frictional resistance.

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

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, and the positioning member 36 is placed on the upper surface of the concrete body 12 to be 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 channel steel material. According to this configuration, it is possible to improve the building accuracy of the steel column 20 in the height direction and the degree of fixation at the time of building.

1, 1A, 1B ... Joint structure between column and pile 10 ... Pile 11 ... Hollow part 12 ... Concrete body 20, 20A ... Steel column 21 ... Column 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 ... Pillar lower 51 ... Pillar upper 52 ... Pillar 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 ready-made concrete pile, a foundation footing in which the pile head of the pile is embedded, and a steel column in which the lower end is embedded in the foundation footing. ,
The ready-made concrete pile and the lower end of the steel column are connected by a steel connecting member embedded in the foundation footing.
The upper end of the connecting member is joined to the lower end of the steel column.
The lower end of the connecting member is embedded in a concrete body filled in the hollow portion of the ready-made concrete pile.
The connecting member functions as a height adjusting member for the steel column by adjusting the buried length, and is fixed to the ready-made concrete pile. .. The connecting member has a vertically extending portion that extends substantially vertically.
The joint structure between a steel column and a pile according to claim 1, wherein the horizontal cross-sectional area of the vertical portion is smaller than the horizontal cross-sectional area of the steel column.

Images