JPH08174054A - Double pipe for concrete composite structure and manufacturing method thereof - Google Patents

Abstract

PURPOSE: To provide a steel tube excellent in a composite structure characteristics with a concrete and a manufacturing method thereof, in a concrete filling steel tube column mainly used as a structural columnar material. CONSTITUTION: This steel tube is a double tube having round cross section and has linear web 1 at the center part and is formed in continuous or discontinuous rugged shape having pulging parts in the length direction on the front and the rear surface of the web 1. Further, the projections may be provided on the inner surface of a flange 2 of the double tube. Then, this double tube is manufactured by bending the flange 2 part of a wide flange beam formed with bulging parts on the front and the rear surfaces of the web 1 by using a double caliber rolling mill.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a concrete-filled steel pipe column mainly used as a column material for a structure, and a double pipe excellent in composite structural characteristics with concrete, and a method for producing the same. .

[0002]

2. Description of the Related Art Concrete-filled steel tubular columns have advantages such as excellent strength and fire resistance of structures, and the advantage that the concrete form can be omitted from the construction method and the construction can be simplified. I'm trying. Conventionally, the steel pipe which is the member is manufactured by bending a thick steel plate and welding the end faces. However, this concrete-filled steel pipe column
If the steel tube columns and the filled concrete are not sufficiently adhered to each other, there is a problem that the required yield strength cannot be exhibited as a structure. As a countermeasure against this, Japanese Patent Publication No. 4-72934 discloses a method of forming a projecting shape on a thick steel plate serving as an original plate of a steel pipe column to form a steel pipe with inner ribs and increasing the adhesion strength thereof. However, when this structure is used under a high yield strength design condition, further improvement is required in terms of reliability as a concrete composite structure and structural yield strength.

[0003]

DISCLOSURE OF THE INVENTION The present invention uses a H-section steel having bulges protruding from the front and back surfaces of a web as a material, and has a high rigidity of concrete and has a high rigidity. And a method for manufacturing this double pipe.

[0004]

SUMMARY OF THE INVENTION The present invention has the following features. That is, in a double pipe in which a flange is bent inward in an arc shape centering on a web of H-section steel, a plurality of bulges protruding on either the front or back surface of the web or the front and back surfaces of the web are lengthwise. A double pipe for concrete composite structures, which is characterized by being installed in rows. The double pipe for concrete composite structure according to the above item, wherein corrugated irregularities are formed on the web surface. The double pipe for a concrete composite structure as described in the above item 1 or 2, wherein a projection is formed on the inner surface of the flange.

In a method of forming a circular double pipe by bending an H-section steel flange inwardly in an arc shape using a double-hole rolling mill, the H-section steel web is previously formed before the bending. 2. A method for producing a double pipe for a concrete composite structure, which comprises arranging a plurality of bulges protruding from the front and back in a lengthwise direction. The method for producing a double pipe for concrete composite structure as described in the above item, wherein corrugated irregularities are formed on the web surface. The method for producing a double pipe for a concrete composite structure according to the above item or paragraph, characterized in that a plurality of projections are formed in advance in the longitudinal direction on the inner surface of the flange portion of the H-section steel, and then the product is subjected to bunge bending.

[0006]

Embodiments of the present invention will be described below. FIG. 1 is a front sectional view of a double pipe according to the present invention, in which the left and right flanges 2 are curved inward in an arc shape with the web 1 as a center, and the abutting portions 3 of the left and right flanges 2 are adhered by means such as welding. ing. FIG. 2 shows H which is a material of the double pipe of the present invention.
It is an example which shows a web shape which is a characteristic of a shaped steel material and a double pipe of the present invention.

2 (A) and 2 (a) show the first embodiment, (A) is a front view and (a) is a side view. In this embodiment, bulges (protrusions) 4a, 4b having a trapezoidal cross section are provided on both sides of the web 1a at predetermined intervals and project in opposite directions at regular intervals. Thereby, the buckling strength and the adhesion strength with concrete can be improved. The bulges 4a and 4b can be formed by rolling using a horizontal roll of a universal rolling machine provided with irregularities on the cylinder peripheral surface before bending forming of a flange described later. In addition, this bulge 4
The patterns of a and 4b are not limited to those shown in the figures, but those having bulges only on one side of the web, or those having bulges obliquely distributed in a grid pattern, and further as a second embodiment shown in FIG.
As shown in (B) and (b), it is possible to select an arbitrary shape such as a projection provided with a checkered pattern 4c.

In order to form the H-shaped steel material for double pipes of FIGS. 2A and 2A into the double pipe of FIG. 1, the forming of the Japanese Patent Application Laid-Open No. 2-80103 previously proposed by the applicant of the present application. The method may be applied. That is, in FIG. 6, (A) is a sectional view of the H-section steel material for double pipes used in the present invention. The web thickness t _W and the flange thickness t _F are made equal to the required thickness of the steel pipe column to be the product. The shape dimension of the butted portion 3 of the double pipe after molding is H
It is determined by the flange width w and the web height h of the shaped steel material and the shape of the protrusions 11 of the roll.

FIG. 6 (B) shows an example of the first-pass hole type, in which the upper and lower rolls 12 form a vertical elliptical caliber having protrusions 11 on the upper and lower sides. In the present invention, the web 1 is oriented horizontally and passed through in the shape of an H-shaped steel. Therefore, a tensile force acts on the web 1 and a compressive force that pushes and bends the web does not act on the web, so that the web can be satisfactorily formed even if the web thickness t _W is thin. The flange 2 of the H-section steel is bent along the caliber wall, but since the projections 11 are provided on the upper and lower sides of the caliber, there is no concern that the rolled material will rotate during passing. That is, since the rolled material is added with an upset amount, which will be described later, the rolled material is restrained and held in the hole die, so that it does not fall or twist and a stable rolled state can be maintained.

FIG. 6 (C) shows an example of a hole type of a few passes. The flange of the H-section steel is bent more largely and has a shape close to a circle, but since the projections 11 are provided on the upper and lower rolls, the rolled material is rolled. It doesn't rotate inside. Further, in such a double pipe product, the web thickness t _W is extremely thin with respect to the flange thickness t _F. Further, since the flange thickness t _F is thicker than the flange width w, good bending is generally difficult. In the method of the present invention, by adding a proper upset amount (0.5 to 2%) to the flange, the forcible bending reduction force at the contact portion between the flange tip and the projection 11 and the inner side of the flange central portion by the web 1 are applied. Due to the pulling restraining force in the direction, even if the flange portion is thick, it can be flexibly deformed into the shapes of the cavities B and C, and the plastic bending process is performed with sufficient compressive force. No springback occurs. Further, there is no occurrence of biting or scratches in the hole-shaped opening P and its vicinity. It should be noted that the upset amount here is 100 (w-l _B ) / w% and 100 (l _B -l _C ) / l, respectively, where the center line lengths of the pore types B and C are l _B and l _C , respectively.
_B %.

FIG. 6D shows an example of finish forming, in which a circular caliber is formed by upper and lower rolls. The material to be rolled is close to circular, and the material to be rolled has a butt portion that is straight and not twisted in the length direction.
In the finish forming pass, the abutting part is a double tube whose length is maintained straight. Here, the shape and dimensions of the web 1 of the double pipe according to the first embodiment are the same as those of the web of the H-section steel material for double pipes according to the present invention shown in FIGS. 2 (A) and 2 (a).

2B and 2B show a second embodiment of the double pipe material according to the present invention. FIG. 2B is a front view and FIG. 2B is a side view. In this embodiment, as described in the first embodiment, projections 4c having a checkered pattern are provided on both front and back surfaces of the web 1b to improve the effect of capturing concrete. Other than that, the method is the same as that of the embodiment shown in FIGS. 2A and 2A, including the method of forming a double pipe.

FIGS. 2 (C) and 2 (c) show a third embodiment of the double pipe material according to the present invention, which is a modification of FIGS. 2 (A) and 2 (a). The front view, (c) is a side view. In this embodiment, bulges 4d and 4e are alternately formed in a corrugated shape (corrugated) on both front and back surfaces of the web 1c. Also in this case, a corrugated concavo-convex pattern can be formed by a method similar to that described with reference to FIGS. Other than that, including the effect and molding method of double pipe,
This is exactly the same as the embodiment shown in FIGS.

FIGS. 2D and 2D show a fourth embodiment of the material for a double pipe according to the present invention. FIG. 2D is a front view and FIG. 2D is a side view. It is a modification of C) and (c). In this embodiment, the bulges 4f and 4g on both the front and back surfaces of the web 1d have a substantially circular or elliptical bowl shape, and the cross section thereof is formed in an arc shape as shown in FIG. The bulges 4f and 4g may be provided only on one side of the web 1d, and may be continuous or discontinuous. Other than that, including the effect and the molding method of the double pipe,
This is exactly the same as the embodiment shown in (A) and (a).

FIGS. 2 (E) and 2 (E) show a fifth embodiment of the double pipe material according to the present invention. This double pipe material is a modification of that shown in FIGS. 2 (D) and 2 (d). An example,
(E) is a front view and (e) is a side view. In this embodiment, the individual arcuate bulges 4h and 4i of the web 1e are formed, and in the bulges 4h and 4i themselves, another S-shaped or reverse S-shaped is formed in the vertical direction of the web. Formed bulges and depressions 5a, 5b are formed. With such a shape, the rigidity of the web 1e and the concrete capturing effect can be further increased. Other than that, as shown in FIG.
This is exactly the same as the embodiment shown in (a).

FIG. 3 is a sixth view of a double pipe material according to the present invention.
It is a perspective view showing an example of. In this embodiment, as shown in FIGS. 2 (A) and 2 (a), the web 1a has a trapezoidal cross-section bulge (projection) 4a which is provided on both sides of the web 1a with a space provided and at least every other space. , 4b are formed. Further, stripe-shaped projections 8 are provided on the inner surface of the flange 2 to enhance the adhesiveness of concrete and the buckling strength of steel pipe columns.

FIG. 4 shows the H-shaped steel material having striped projections 8 and bulges (projections) 4a, 4b having a trapezoidal cross section on the inner surface of the flange 2 and the front and back surfaces of the web 1a, respectively. Here, in the perspective views of FIGS.
Is the surface of the web 1a and is shown, whereas 4 is
Although b is located in the middle of 4a, it is not shown because it is on the back surface of 1a. The striped protrusions 8 and the bulges 4a and 4b having a trapezoidal cross section are the process of rolling the flange and the web with the striped recesses and the universal vertical rolls 10 engraved on the side surface of the universal horizontal roll 9 of the universal rolling mill of FIG. Can be formed with.

The double pipe according to the sixth embodiment can remarkably enhance the trapping effect during concrete filling.
Of course, depending on the use and application conditions of the steel pipe column, the required function can be sufficiently satisfied without the projection on the inner surface of the flange as in the first to fifth embodiments. Although the web of FIG. 3 is the same as that of FIGS. 2A and 2A in this embodiment, it may be combined with other shapes and patterns. Other than that, the method is the same as that of the embodiment shown in FIGS. 2A and 2A, including the method of forming a double pipe.

[0019]

EFFECTS OF THE INVENTION According to the double pipe of the present invention, it is possible to fill concrete inside and use it as a high rigidity concrete filled steel pipe column as a composite structure with concrete. That is, in the double pipe of the present invention, since the web serving as the reinforcing rib is interposed on the inner surface of the cylinder, the buckling strength of the steel pipe column is dramatically improved. Further, when filling the concrete, the adhesion to the concrete is improved by the continuous or discontinuous projections or corrugated unevenness provided on the front and back of the web.
Furthermore, by forming a protruding bulge on the inner surface of the flange, the adhesion and capture of concrete is improved,
The reliability as a high-strength concrete composite structure is improved.

[Brief description of drawings]

FIG. 1 is a front sectional view of a double pipe according to the present invention.

2A to 2E are front views of an H-shaped steel material for double pipes according to the present invention. (A)-(e) is a side view corresponding to (A)-(E) of the H-section steel material for double pipes concerning this invention.

FIG. 3 is a perspective view showing another embodiment of the double pipe according to the present invention.

FIG. 4 is a perspective view of the H-shaped steel material for double pipes of FIG.

5 is an explanatory view showing an example of universal rolling of the H-shaped steel material for double pipes of FIG.

FIG. 6 is an explanatory view showing an example of a method for forming a double pipe according to the present invention.

[Explanation of symbols]

 1, 1a to 1e ... Web 2 ... Flange 3 ... Butt portion 4a to 4i ... Expansion 5a ... Depression 5b ... Expansion 8 ... Striped projection 9 ... Universal horizontal roll 10 ... Universal vertical roll 11 Roll projection 12 Vertical roll

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinya Hayashi 1 No. 1 Tsukiko Hachiman-cho, Sakai City, Osaka Prefecture Nippon Steel Corporation Sakai Steel Co., Ltd.

Claims (6)

[Claims] 1. A double pipe in which a flange is bent inward in an arc shape around a H-section steel web as a center, and a plurality of bulges protruding from either the front surface or the back surface of the web are formed. A double pipe for a concrete composite structure characterized by being arranged in the length direction. 2. The double pipe for a concrete composite structure according to claim 1, wherein corrugated irregularities are formed on the web surface. 3. The double pipe for concrete composite structure according to claim 1, wherein a protrusion is formed on the inner surface of the flange. 4. A method of forming a circular double pipe by bending an H-section steel flange inwardly in an arc shape by using a double-hole rolling mill, and forming the H-section steel in advance before the bending. A method for producing a double pipe for a concrete composite structure, comprising arranging a plurality of bulges protruding from the front and back of the web in the longitudinal direction. 5. The method for producing a double pipe for a concrete composite structure according to claim 4, wherein corrugated irregularities are formed on the web surface. 6. The double pipe for a concrete composite structure according to claim 4, wherein a plurality of projections are preformed in the length direction on the inner surface of the flange portion of the H-section steel, and then flange bending is performed. Manufacturing method.