JPH10168896A - Basic structure of steel frame structure - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a foundation structure of a steel frame structure that can be easily designed and constructed with a solid foundation that does not require a foundation beam. SOLUTION: The bending moment transmitted from a ramen column is borne by a steel base (5) to which the ramen column () is fixed, and is not transmitted to the solid foundation (1) side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foundation structure used for a steel frame structure.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, the base of a steel frame structure using a solid base is used. That is, a foundation slab (32) made of concrete with reinforcing bars (31)
A foundation beam (34) is also constructed with reinforcing bars (33), and the base plate at the lower end of the column base (35) is placed on the foundation beam (34).
(36) is installed and fixed with anchor bolts (37) buried in the foundation beam (34). Both the bending moment from the first floor and the bending moment due to the ground reaction force from the ground side Is received by the foundation beam (34). At this time,
Mortar for horizontal accuracy is provided on the top of the foundation beam (34).
(38) has been constructed.

[0003]

In the above-mentioned conventional foundation structure, first, both the bending moment from the first floor and the bending moment due to the ground reaction force are received by one foundation beam (34). A large section foundation beam (34) is required, and the entire foundation becomes larger.

In order to secure the strength of the foundation beam (34),
The joints between the foundation beams (34) need to have enough joint bars, and the notches such as the entrance also need enough reinforcing bars. is there.

[0005] Further, the column pedestal is a place where a steel column manufactured in a factory having completely different precision and mechanical properties is joined to an RC foundation for on-site construction. Because there are many conditions, it is a place where problems easily occur.

In other words, the installation of anchor bolts and the concrete casting of the foundation are performed by the construction company, and the steel frame above the base plate is manufactured by a specialized steel frame processing company. May be more difficult, leading to poor construction.

[0007] Therefore, it is extremely important to ensure the construction accuracy for accurately anchoring the anchor bolts at the predetermined positions. However, among the limited foundation beams, there are considerably many joint bars and reinforcing bars in addition to the main bars. It is difficult to accurately install large anchor bolts here, and it is also conceivable that concrete anchors may be moved by casting concrete, making it extremely difficult to secure construction accuracy.

According to a survey of an actual building, the adhesion between the base plate and the mortar beneath the base plate is not always good, and cavities often occur. In this case, there is a problem that a required degree of fixation is not easily obtained, and a precondition for designing a reinforced concrete section by regarding the dimensions of the bottom surface of the base plate as a concrete section and regarding the anchor bolt as a reinforcing bar is broken.

An object of the present invention is to solve the above-mentioned drawbacks of the conventional foundation structure and to provide a foundation structure of a steel frame structure that is easy to design and construct with a simple foundation that does not require foundation beams. It is intended for.

[0010]

In order to solve the above-mentioned problems, the present invention disposes a steel frame base between a reinforced concrete foundation and a steel column base so that a bending moment from the first floor is borne by the base. The structure is such that the reaction force from the ground is borne by the reinforced concrete foundation.

Above, a solid foundation without beams is used for the reinforced concrete foundation.

[0012] Also in the above, the steel column base and the steel base are usually joined by high strength bolts.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 and 2, (1)
This is a solid foundation consisting solely of a flat foundation slab cast on the improved ground (2) via a foundation slab concrete (3). Reinforcing bars are arranged in this solid foundation (1),
Since it is a flat simple structure without a foundation beam, it is sufficient to arrange a wire mesh (4) made of rebars of different diameters as shown in the figure.

(5) is a steel base made of H-section steel,
While being installed on the solid foundation (1) via the base plate (6), the joints between the steel bases (5) and (5) are
Using the joining plate (7), the members are joined with high-strength bolts (8) (8). As shown in FIG. 1, at a portion where the steel bases (5) and (5) are joined at right angles, a stiffener (9) is welded in advance between flanges of one steel base (5) and the other steel base is used. The web portion of (5) is joined with the joining plate (7).

Numeral (11) is a ramen column to be joined on the steel base (5). As shown in FIG. 2, the ramen column (11) has a pair of flanges (12) (12) ( 12) and one or more steel webs (13) connecting between the flanges (12) and (12), and the web (13) has a large number of horizontally long slits ( 14), (14)... Are arranged vertically. That is, the ramen pillar (11)
When a large bending moment is applied during a large earthquake, the slit (14) as a seismic damper is plastically deformed, thereby absorbing its energy and the supporting capacity of the vertical load by the rigid frame column (11) is not impaired In this way, the web (13) provided with the slit (14) can be repaired only by replacing the web (13).

In addition, the slits (14) correspond to the pillars (11).
Also serves to reduce the bending moment transmitted from the steel base (5) to the steel base (5), so that when the steel base (5) bears such bending moment, only the steel base (5) is sufficient. I am able to bear it. At the lower end of the flanges (12) and (12), a cross-shaped column base member (1
5) is projected along the web (13), and the base plate (16) joined to the lower end thereof is attached to the steel base (5).
Installed on the upper surface of the flange and joined with high strength bolts (17),
Thereby, the bending moment of the ramen column (11) is transmitted to the steel frame base (5).

The steel frame (5) is provided with the base plate (6).
Above, it is joined to an anchor bolt (10) which protrudes upward through its base plate (6) and is pre-buried in the solid foundation (1). Since it does not have the function of transmitting the bending moment from the solid foundation (1) side to the steel base (5) or transmitting it from the steel base (5) to the solid foundation (1),
A simple pin connection will suffice.

Therefore, there is no strict restriction on the size of the gap between the anchor bolt (10) and the bolt hole of the steel base (5), and a bolt only corresponding to the error of the position of the anchor bolt (10). As the hole diameter, such anchor bolts (1
The position error of (0) can be absorbed.

FIG. 3 shows a solid foundation (1) of the steel base (5).
It is a floor plan showing the arrangement on the top, steel base such as entrance (17)
In a portion where (5) is unnecessary, the steel base (5) may be omitted, and it is not necessary to cut out a foundation beam made of reinforced concrete and insert a complicated reinforcing bar or the like as in the related art.

As shown in FIG. 4, the ramen columns () at the corners are formed by connecting three steel pipe flanges (12) (12)... Connect with (13).

[0021]

According to the present invention, the bending moment of the first floor from the ramen column is borne by the steel base and is not transmitted to the foundation concrete side, so that there is no need to provide a reinforced concrete foundation beam as in the prior art. The solid foundation only needs to be a simple flat foundation slab, so the reinforcement is simpler and the temporary frame is also simpler, so the construction work is extremely simple, and the anchor buried in the solid foundation There is little risk that the bolts will be hindered by the reinforcement.

Further, even if the steel frame base is installed on a solid foundation, it is sufficient that the steel base is simply installed on the solid foundation and joined with anchor bolts. Further, the anchor bolt and the steel base are simple. Since pin bonding is sufficient, as described above, there is no strict requirement for the positional accuracy of the anchor bolt as in the related art, and the construction work becomes easy even in consideration of installing such a steel base.

On the other hand, the joint between the steel frame base and the ramen column is also jointed by high-strength bolts. Since both are high-precision steel frames, the joining operation is easy and the joints can be made with high accuracy. In addition, since there is no need to fill mortar between them, there is no occurrence of voids and voids as in the conventional case.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a main part showing an embodiment of the present invention as viewed from a side of a column base.

FIG. 2 is a longitudinal sectional view of a main part, also viewed from the column base front direction.

FIG. 3 is a plan view showing an arrangement of a steel base on a solid foundation.

FIG. 4 is a cross-sectional view of a column base at an L-shaped corner portion.

FIG. 5 is a vertical sectional view of a main part showing a structure of a conventional joint between a ramen column and a solid foundation.

[Explanation of symbols]

 (1) Solid foundation (5) Steel base (6) Anchor bolt (11) Ramen column (17) High strength bolt

Claims (3)

[Claims] A steel base is arranged between a reinforced concrete foundation and a steel column base, and a bending moment from the first floor is borne by the base, and a bending moment due to a ground reaction force from the ground is borne by the reinforced concrete foundation. Basic structure in steel frame structure characterized by having a structure. 2. The foundation structure according to claim 1, wherein the reinforced concrete foundation is a solid foundation having no beams. 3. The steel frame base structure according to claim 1, wherein the steel column base and the steel base are joined by high-strength bolts.