JP3336367B2 - Steel column base structure and construction method of steel column base - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a column base structure of a steel column constructed on a concrete foundation having an underground beam, and a steel column base constructed by the column base structure of the steel column. More particularly, the present invention relates to a steel column base structure or a steel column base suitable for application to, for example, a steel structure having up to about three stories.

[0002]

2. Description of the Related Art In general, a column base design of a steel column in a steel structure building is performed by fixing a column base (in the vicinity of a lower end attached to a concrete foundation of the column) to a concrete foundation and causing the column base to generate a moment. There are fixed column bases that are responsible for the support, and pin support column bases that are supported on the concrete foundation by the pin structure and do not receive moment. In addition, the former fixed column base has an embedded column base embedded in the concrete foundation, a column base provided on the ground, but with the base wound by concrete, and an exposed fixed base described later. There is a pedestal. The embedded column base and the base column base can be regarded as completely fixed column bases in terms of structural design. On the other hand, as shown in FIG. 7, the exposed fixed column base is provided with an anchor bolt 4 embedded in the concrete foundation 3 and a nut 5 screwed to the base plate 2 of the column base 1a placed on the concrete foundation 3. A column base structure for fixing the base plate 2 to the concrete foundation 3. The exposed fixed column base, when a moment acts on the column base 1 a,
As shown in FIG. 8, since the anchor bolt 4 is stretched and the column 1 is inclined (although very slightly), the moment cannot be completely covered, and it cannot be said that it is a completely fixed column base. It is called a fixed or elastic column base. In addition, this exposed fixed pedestal is, like a completely fixed pedestal (embedded pedestal or pedestal pedestal), between the underground pillar and the pillar as shown in FIG. The center beam 7 is formed integrally with the concrete foundation 3 so that the underground beam 7 bears a moment acting on the column base 1.

[0003] As described above, there are various types of column base structures. Conventional column bases are either completely fixed column bases or semi-fixed column bases (exposed fixed column bases). Although it is approximated in the calculation, the completely pin-supported column base structure is not adopted as the steel column base structure of the steel columns of the actual steel structure building.

[0004]

The above-mentioned exposed fixed column base is easier to construct than a completely fixed column base. However, the underground beam 7 is designed to be large in order to handle the moment acting on the column base. There is a need. Further, it is necessary to use an anchor bolt having a large size in accordance with the moment at which the pullout stress acts. The exposed fixed column base is formally a completely fixed column base, but the entity is semi-fixed, and the calculation in the design of the column base structure and the entity do not match,
Therefore, the concrete foundation 3 or the underground beam 7 or the anchor bolt 4 or the like often becomes overspec.

By the way, if the column base is a pin supporting column base,
Since the column base does not bear the moment, the underground beam which also acts as the moment can be made small, the anchor bolt can be made small, and the calculation and the substance in the column base design can be reduced. There is the advantage that they can be matched. Of course, in the case of the pin support column base, it is necessary to give the moment to the steel structure as much as the column base does not receive the moment, and it is necessary to increase the rigidity of the steel frame structure itself. This does not necessarily mean that the pin-supported column base is superior. However, under various conditions, for example, when the site foundation has a large restriction on the site foundation work, the pin-supported column base is better. May be appropriate. However, in the past, pin-supported column bases had problems such as unstable columns during construction and poor workability.
It has not been adopted as a column base structure of steel columns in an actual steel structure building.

The present invention has been made in view of the above circumstances, and a pin support column base is practically realized, an underground beam can be reduced, and an anchor bolt can be reduced in size. It is still another object of the present invention to provide a column base structure of a steel column and a method of constructing the column base, which can completely match the calculation and the entity in the structural design of the column base.

[0007]

According to the present invention, there is provided a column base structure of a steel column having a base plate portion mounted on a concrete foundation and fixed by anchor bolts and nuts, and a hemispherical concave portion. A lower member comprising a receiving portion integrally formed on the upper side of the base plate portion; a spherical portion fitted into the hemispherical recess of the receiving portion of the lower member; An upper member having a sphere having a flange portion joined to the lower member, and a retainer fixed to the receiving portion with bolts so as to press the sphere portion of the upper member fitted into the hemispherical concave portion of the receiving portion of the lower member. It is characterized by comprising a metal fitting and a mounting bolt for adjusting the distance between the flange portion and the receiving portion at at least four corners thereof until the construction is completed.

[0008] A second aspect of the present invention is a method of constructing a steel column pedestal in which a steel column pedestal is constructed on a concrete foundation provided with an underground beam by the column structure of a steel column according to the first aspect. Placing the lower member on a foundation and fixing the lower member to a concrete foundation with anchor bolts and nuts; and fitting the spherical portion of the upper member into the hemispherical recess of the lower member. Erecting a steel column on the lower member, connecting the four corners of the flange portion of the upper member and the four corners of the lower member with the mounting bolts, and adjusting the connection intervals at the four corners. The verticality adjusting step of adjusting the verticality of the steel column, and fixing the holding member to the upper surface of the lower member with a bolt by pressing the sphere of the upper member with the holding member. Line after or before A step of applying a waterproofing means for preventing water from entering a gap between the spherical portion of the upper member and the presser fitting, and a step of removing the mounting bolt and nut after completion of the construction. I do.

According to a third aspect of the present invention, in the method of constructing a steel column base according to the second aspect, when the lower member placed on the concrete foundation is fixed with the anchor bolts and the nuts, the concrete foundation column is initially formed. A mortar for centering and leveling the pillars is installed at the position, and after the waterproofing means is applied, the gap between the lower member and the concrete foundation is filled with a filler.

According to a fourth aspect of the present invention, in the method for constructing a steel column base according to the second or third aspect, there is provided a step of providing a waterproofing means for preventing water from entering a gap between the spherical portion of the upper member and the presser fitting. Features.

[0011] The column base structure of the steel column according to claim 5 is as follows.
In the column-base structure of the steel column, the spherical portion and the receiving portion are turned upside down, that is, the spherical portion is provided on the base plate side, and the receiving portion having a hemispherical concave portion for fitting the spherical portion is provided on the steel column. It is provided on the flange portion side joined to the main body.

According to a sixth aspect of the present invention, there is provided a method of constructing a steel column base on a concrete foundation having an underground beam by using the steel column column structure according to the fifth aspect. This is the method of leg installation.

[0013]

FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given with reference to an embodiment shown in FIG. FIG. 1 is a front view of a steel column base structure 11 according to one embodiment of the present invention, FIG. 2 is a partially sectional view of the column base structure 11 of FIG. 1, and FIG. A sectional view and FIG. 4 is a sectional view taken along line BB of FIG. As shown in FIG. 5, the column base structure 11
It is constructed on a concrete foundation 3 integrally formed with the above.
It is also suitable for use as a column base structure of steel columns in a steel structure building up to about three stories.

The column base structure 11 is a concrete base 3
A lower member 16 comprising a base plate portion 14 mounted thereon and fixed by anchor bolts 12 and nuts 13 and a receiving portion 15 having a hemispherical concave portion 15a and integrally formed above the base plate portion 14; This lower member 1
Spherical part 1 fitted into hemispherical concave part 15a of receiving part 15 of No. 6
7 and a spherical upper member 19 having a flange 18 to which the lower end of the steel column main body 21 is integrally joined, and a sphere of the upper member 19 fitted into the hemispherical recess 15a of the lower member 16. A holding member 24 fixed by bolts 23 is provided on the upper surface of the receiving portion 15 of the lower member 16 so as to hold the portion 17. In the embodiment, the steel column main body 21 is used.
Is a square pipe, and the lower member 16, the holding metal 24, and the upper member 19 are all made of cast steel. Steel pillar body 2
1 and the upper member 19 constitute a steel column 22.

The upper member 19 has a structure in which the spherical portion 17 is formed on the lower surface side of the flange portion 18 through the neck portion 17a, and the square cylindrical portion 20 fitted on the inside of the steel column main body 21 is formed on the upper surface side. And the tubular joint 20 is made of steel column body 2
1 is welded and fixed to the lower end. Holes 18 through which the bolts 30 are inserted are provided at the four corners of the flange 18.
In the four corners of the receiving part 15 of the lower member 16 corresponding to these four holes 18a, there are screw holes 15b into which screw parts near the lower end of the mounting bolt 30 are screwed. Further, the holding hardware 24 is composed of two metal pieces 24a.
This is a structure in which the joining flanges 24b provided on the two metal pieces 24a are respectively fastened and joined by bolts 27.

A method of constructing the column base structure 11 will be described. An anchor bolt 12 is embedded in the concrete foundation 3 in advance. Mortar 31 for pillar centering and verticality adjustment at pillar position of concrete foundation 3
The lower member 16 is placed on the mortar 31 so as to be aligned with the column center, and the anchor bolt 12 and the nut 13 are mounted.
Then, the lower member 16 is fixed to the concrete foundation 3.
Next, the upper member 1 is inserted into the hemispherical concave portion 15a of the lower member 16.
9 and the steel pillar 22 is fitted to the lower member 16.
Stand on top. Next, four bolts 30 are inserted from the four corner holes 18a of the flange portion 18 of the upper member 19, and the lower end screw portions are screwed into the four screw holes 15b of the receiving portion 15 of the lower member 16, The nuts 32 are screwed into the screw portions at the upper ends, and the screwing amounts of the nuts 32 are adjusted to adjust the verticality of the steel columns 22 while the upper member 1 is adjusted.
9 is fixed to the lower member 16 side. In this state, the rotation of the upper member 19 is restricted and the upper member 1 is restricted.
9 can maintain the vertical state stably during the construction, so that the steel frame construction can be performed without any trouble.

Next, the holding metal piece 24 is placed on the receiving portion 15 of the lower member 16 so as to press the spherical portion 17 of the upper member 19 with its spherical inner surface, and the two metal pieces 24a are joined. The flanges 24b are joined together by tightening and joining together with bolts 27.
Thus, the holding metal 24 is fixed to the receiving portion 15 side.

Next, as a foreign matter intrusion prevention means for preventing foreign matter such as water and earth and sand from entering a gap between the spherical body portion 17 of the upper member 19 and the holding member 24, a cover 33 made of, for example, styrene foam or rubber is provided. Provide. Spherical part 1
If water or the like intrudes into the inner surface of the base member 7 or the inner surface of the lower member 16 or the presser fitting 24 and rust is generated, the smoothness of sliding of the spherical body portion 17 is impaired. Although the operation is impaired, the cover 33 can prevent this. The cover may be formed by filling a fluid or plastic compound in the vicinity of the gap and solidifying the compound. Next, a filler is filled in a gap between the lower member 16 and the concrete foundation 3.

After the above-mentioned construction of the column pedestal is completed, the bolt 30 for building is removed. Instead of removing the bolt 30 for installation, the nut 32 may be simply loosened so that the action of fixing the flange portion 18 of the upper member 19 to the lower member 16 does not occur.

In the column base structure 11 constructed as described above, no moment acts on the column base because it is a complete pin supporting column base. Therefore, the underground beam 7 which also acts to take the moment need not be so large. Further, since it is not necessary to set a large design pulling force with respect to the anchor bolt, the anchor bolt can be reduced in size. Therefore, the method of the present invention is particularly effective when it is inconvenient to form the underground beam 7 large or when it is desired to reduce the anchor bolt. Further, the design and the entity do not coincide with each other as in the case of the exposed fixed column base, and the design and the entity completely coincide with each other, so that a clear design can be performed with respect to the design conditions.

In the embodiment described above, the lower member 1
6 and the first base plate 14 integrated with the receiving portion 14.
The base plate is separated into a base plate and a second base plate separate from the base plate, and the two are fixed to each other with bolts.
The upper part 19 has a flange 1
8 also has a two-piece structure in which a first flange part integrated with the spherical body part 17 and a second flange part integrally joined to the steel column main body 21 are separated and the two pieces are fixed to each other with bolts. You can also. In this case, the receiving portion 15 and the spherical portion 17 are fitted in advance, and the holding metal 24 is attached.
The assembled product is disposed between a second base plate fixed to a concrete foundation 3 with anchor bolts 12 and a second flange portion integral with the steel column main body 21, and
A method of fixing the base plate portion and the first flange portion to the second base plate portion or the second flange portion with bolts, respectively, can be adopted.

FIG. 6 shows an embodiment of a column base structure of a steel column according to claim 5. The column base structure 11 ′ of a steel column is the column base structure 11 described with reference to FIGS. 1 to 5, in which the sphere portion 17 and the receiving portion 15 are turned upside down. That is, the column base structure 11 'has a flange portion 18' integrally joined to the lower end of the steel column main body 21 and a hemispherical concave portion (similar to the semispherical concave portion 15a in FIG. 2). 1
An upper member 19 'comprising a receiving portion 15' integrally formed below 8 ', a base plate portion 14' mounted on a concrete foundation and fixed by anchor bolts 12 and nuts, and the upper member 19 '. Member 1 having a spherical portion 17 'fitted into the hemispherical recess of the receiving portion 15'
6 'and a holding member fixed to the receiving portion 15' with bolts so as to press the spherical portion 17 'of the lower member 16' fitted into the hemispherical recess of the receiving portion 15 'of the upper member 19'. 24 'and the flange 1 until the construction is completed.
There is provided a mounting bolt (not shown in FIG. 6 since the construction is completed) for connecting the 8 'and the receiving portion 15' at at least four corners so as to adjust the mutual distance therebetween. The construction method of constructing the column base structure 11 ′ of the steel column described above is different from the construction method of constructing the column base structure 11 described with reference to FIGS. 1 to 5 in that the spherical portion and the receiving portion are turned upside down. However, the basic concept is almost the same, and the procedure can be performed in accordance with the difference in the column base structure. The same operation and effect as the steel column base structure 11 shown in FIGS. 1 to 5 can be obtained by the steel column base structure 11 ′.

The upper member 19 or 19 'of the embodiment is used.
Is a separate body from the steel column main body 21 and is fixed by welding to the steel column main body 21. However, the upper member may be formed integrally with the steel column main body. In short, what is necessary is just to have a spherical part or a receiving part at the lower end of a steel pillar. Further, the steel pillar body is not limited to a square pipe, but may be a round pipe, an H-section steel, or the like.

[0024]

According to the present invention, a column base structure using a pin supporting column base that can be practically used can be realized. As a result, the underground beam can be made smaller, the anchor bolt can be made smaller, and the calculation and the actual body can be completely matched in the structural design of the column base.

[Brief description of the drawings]

FIG. 1 is a front view of a column base structure of a steel column according to one embodiment of the present invention.

FIG. 2 is a sectional view showing a part of the column base structure of FIG. 1;

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a sectional view taken along line BB in FIG. 2;

FIG. 5 is a view showing the column base structure of FIG. 1 together with a concrete foundation and an underground beam.

FIG. 6 is a view showing a column base structure of a steel column according to an embodiment of the present invention, together with a concrete foundation and an underground beam.

FIG. 7 is a view showing a conventional example, and is a view showing a general exposed fixed column base structure.

FIG. 8 is a diagram illustrating that the exposed fixed column base structure of FIG. 7 is a semi-fixed column base.

[Explanation of symbols]

 3 Concrete foundation 7 Underground beam 11, 11 'Column base structure 12 Anchor bolt 13, 32 Nut 14, 14' Base plate portion 15, 15 'Receiving portion 15a Semispherical concave portion 15b Screw hole 16, 16' Lower member 17, 17 'Spherical part 18, 18' Flange part 18a Hole 19, 19 'Upper member 20 Cylindrical joint part 21 Steel column main body 22 Steel column 24, 24' Holder 24a Metal piece 24b Joint flange 27 Bolt 30 Bolt for construction 31 mortar 33 cover 34 filler

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E04B 1/24 E02D 27/00 E04B 1/36 E04H 9/02 331 E01D 1/00-23/00

Claims (6)

(57) [Claims] 1. A lower member comprising: a base plate portion mounted on a concrete foundation and fixed by anchor bolts and nuts; and a receiving portion having a hemispherical recess and integrally formed above the base plate portion; An upper member having a sphere having a spherical portion fitted into the hemispherical recess of the receiving portion of the lower member and having a flange integrally joined to the lower end of the steel column main body; A presser fitting fixed to the receiving portion with bolts so as to press the spherical portion of the upper member fitted into the hemispherical concave portion of the portion, and at least four corners of the flange portion and the receiving portion until completion of construction. And a building bolt for adjusting the distance between the columns so as to be adjustable. 2. A method for constructing a steel column pedestal according to claim 1, wherein the steel column pedestal is constructed on a concrete foundation provided with an underground beam. Mounting the lower member and fixing the lower member to a concrete foundation with anchor bolts and nuts; and fitting a spherical portion of the upper member into the hemispherical recess of the lower member to form a steel column. By setting the four corners of the flange portion of the upper member and the four corners of the lower member with the installation bolts, and adjusting the connection intervals at the four corners, thereby making the steel After or before the verticality adjusting step of adjusting the verticality of the column, and fixing the holding member to the upper surface of the lower member with a bolt by pressing the sphere of the upper member with the holding member. The process to be performed Removing the installation bolts and nuts after the completion of the work. 3. The method according to claim 2, wherein when the lower member placed on the concrete foundation is fixed with anchor bolts and nuts, the column is placed at the column position of the concrete foundation in an initial stage. Mortar for centering and adjusting the verticality of the mortar, and after the step of fixing the holding member to the upper surface of the lower member with bolts, filling the gap between the lower member and the concrete foundation with a filler. A method of constructing a steel column base characterized by the following. 4. The steel column pedestal according to claim 2, further comprising a step of providing a foreign matter intrusion preventing means for preventing foreign matter from entering a gap between the spherical body portion of the upper member and the holding member. Construction method. 5. An upper member comprising a flange portion integrally joined to a lower end of a steel column main body and a receiving portion having a hemispherical concave portion and integrally formed below the flange portion, and a concrete base. A lower member having a base plate portion mounted on the base member and fixed by anchor bolts and nuts, and a spherical portion fitted into the hemispherical concave portion of the receiving portion of the upper member; and a hemispherical concave portion of the receiving portion of the upper member. A presser fitting fixed to the receiving portion with bolts so as to press the spherical portion of the lower member fitted to the lower member, and the flange portion and the receiving portion are spaced apart from each other at least at each of the four corners until the completion of construction. A steel column pedestal structure comprising: a mounting bolt that is adjustably coupled. 6. A method of constructing a steel column pedestal according to claim 5, wherein the steel column pedestal is constructed on a concrete foundation provided with an underground beam. Mounting the base plate portion of the lower member and fixing the base plate portion of the lower member to a concrete foundation with anchor bolts and nuts; and a hemisphere of a receiving portion of the upper member on the sphere portion of the lower member. Erecting the steel column on the lower member by fitting the concave portion, and connecting the four corners of the flange portion of the upper member and the four corners of the base plate portion of the lower member with the setting bolt, respectively; A verticality adjusting step of adjusting the verticality of the steel column by adjusting the coupling intervals in the above, and holding the holding metal to the upper member by pressing the sphere of the lower member from below with the holding metal. Fixing the bolts to the lower surface of the joint, after or before the verticality adjusting step, and removing the mounting bolts and nuts after the completion of the work;
A method for constructing a steel column base, comprising: