JP2516831B2 - Large beam and small beam connection structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a joint structure of steel-framed large beams and small beams.

(Prior Art) Conventionally, in a steel frame structure, when connecting a girder and a girder so as to form a continuous beam structure extending in the girder axial direction, the girder shafts are connected to the girder joints in the same manner as the girder. A gusset plate protruding in the direction was attached, the gusset plates were tightly connected with each other by high-tensile bolts, and the upper flanges were welded together to form a rigid joint, forming a continuous beam structure.

Further, JP-A-60-212540 (Japanese Patent Application No. 59-67439:
In the title of the invention "joint between PC beam and SRC beam"), while the compression main rebar is projected from the end of the PC beam,
A gusset plate is projected as a shear resistance member, the same member is joined to the gusset plate of the SRC girder with a high-tensile bolt and the concrete is placed by placing the girder and the girder into one piece, and a precast beam is formed. A construction method has been proposed in which the support work is omitted and the workability is improved.

(Problems to be solved by the invention) However, in the former case, the processing and welding process of the steel frame for rigidly joining the reinforcing bar large beam and the small beam is complicated,
In the case of a long span, bending and vibration are likely to occur, so the floor height of the building becomes high in order to prevent this by increasing the beam formation.

In the latter case, it is possible to use a precast beam to omit the support work during the beam construction and improve workability.However, in the case of a long span, the cross section becomes large and the weight of the member increases. There was a problem that inconvenience occurred in the production and construction process of.

The present invention has been proposed in view of the above problems of the prior art, and its object is to provide a girder that has a higher rigidity, a reduced amount of bending, and a higher structural reliability as compared with the conventional structure. The point is to provide a joint structure of beam and beam.

(Means for Solving the Problems) In order to achieve the above object, a joint structure of a girder and a girder according to the present invention is composed of a beam steel frame composed of upper and lower flanges and a web, and the beam steel frame is provided at a girder joint position. And a steel frame large beam in which a gusset plate is projected sideways orthogonally to the same beam steel frame, and a steel frame reinforced concrete part in which an upper surface defect portion equal to the slab thickness is provided at the joint end to the large beam is formed, And a steel frame girder in which a gusset plate is projected from the girder joint end face, the gusset plates facing each other of the girder and the girder are joined with a high-tensile bolt, and the upper surface of the girder and both sides of the girder are sandwiched. Reinforcing steel bars are arranged over the upper surface defective portion of the steel-framed reinforced concrete portion of the steel beam beam arranged in the above, and the upper surface of the steel beam beam including the defective portion and the girder beam beam joint are connected to each other. It is constructed by placing a cleats.

(Operation) As described above, according to the present invention, since the joints at both ends of the steel beam to the girder constructed between the steel girders have a steel reinforced concrete structure, the length of the intermediate pure steel part is shortened. The rigidity is higher and the amount of bending is smaller than that of the conventional pure steel beam.

Further, on the upper surface of the steel frame reinforced concrete portion formed at the joints at both ends of the steel beam, a defect portion having the same thickness as the slab is provided. The large beam and the small beam are rigidly joined together by reinforcing bars being laid out over the upper surface defective portion of the steel-framed reinforced concrete portion and by placing concrete.

(Examples) The present invention will be described below with reference to illustrated examples.

1 to 3, (A) is a steel frame girder having an H-shaped cross section composed of upper and lower flanges and a web as shown in FIG. 1, and (B) is installed between adjacent girders (A). In the steel beam, a steel reinforced concrete portion (a) having a slab thickness t is formed at both ends of the beam (B), and a gusset plate (a shearing resistance member is formed from the end face of the beam (B). 1) is projected.

In the figure, (2) is the concrete part of the steel-framed reinforced concrete part (a), (3) is the lower horizontal reinforcing bar of the part,
(4) is a rib that is wound around the reinforcing reinforcing bar (3), and the upper end thereof projects into the upper surface defect portion of the steel frame reinforced concrete part (a).

Further, a gusset plate (5) constituting a shear resistance member is provided at the beam connecting position of the large beam (A) in a protruding manner.

Then, the steel beam (B) is erected on the adjacent steel beam (A), and the gusset plates (1) and (5) are joined by high-tensile bolts (6). Steel frame reinforced concrete parts (a) on the upper surface and adjacent steel beam (B) (B) arranged on both sides of the same large beam (A).
Reinforcing reinforcing bars (7) are arranged over the defect portion of the upper surface, and concrete (8) (8 ') is placed on the upper surface of the steel beam (B) and the joint portion of the girder beam including the defect portion. Steel beam (A)
And the steel beam (B) are rigidly joined.

4 and 5 show a frame structure of a building to which the present invention is applied, in which (C) is a pillar.

In the illustrated embodiment, as described above, the joints at both ends of the steel beam (B) that is constructed between the adjacent steel beam (A) are
Since it has a steel frame reinforced concrete structure, the length of the pure steel frame portion is shortened, the rigidity is higher and the amount of bending is smaller than that of the conventional pure steel frame beam.

Further, as described above, the reinforcing bar (7) having the steel beam (B) and the steel beam (A) arranged on the upper surface thereof,
Rigid joints are made by concrete (8) and (8 ') cast on the upper surface, the large beam, and the small beam joints.

FIG. 7 is a flexure diagram, and a solid line shows a beam of a continuous beam (continuous beam) structure constituted by the present invention, a dotted line shows a beam of a conventional continuous beam structure, and the flexible beam Δ ₁ in the present invention is It can be seen that the deflection is smaller than that of the conventional structure, Δ ₂ .

FIG. 8 is a bending stress diagram, in which the structure of the present invention is shown by a solid line and the conventional structure is shown by a dotted line. According to the present invention, the bending stress of the steel beam (B) is reduced as compared with the conventional structure, and It has been shown that the beam cross section can be reduced.

FIG. 6 shows another embodiment of the present invention, in which a steel beam girder having a reinforced concrete portion (a) having a slab thickness t at both ends is formed on a PC girder (A ') having a slab thickness t. (B) is continuously framed, reinforcing reinforcing bars (7) are laid over the portions of the upper surfaces of the PC girder (A ') and the steel beam (B) where the slab thickness t is missing, and concrete ( 8 ″) is driven to rigidly join the large beam (A ′) and the small beam (B).

In the figure, the same parts as those in the above-mentioned embodiment are designated by the same reference numerals.

(Effects of the Invention) According to the present invention, as described above, the upper surface of the girder composed of the beam steel frame composed of the upper and lower flanges and the web, and the both ends of the girder with the girder interposed therebetween, and the joint ends are slabs. Across each upper surface of the opposing steel beam formed in the reinforced steel concrete portion having the upper surface defect portion having the same thickness,
Place reinforcing steel bars and place concrete,
By rigidly joining the large beam and the steel frame small beam and making the small structural type a continuous beam structure, the cross section of the steel frame small beam can be reduced, the economical efficiency can be improved, and the workability can be improved.

Further, since both ends of the steel frame beam are formed in the steel frame reinforced concrete portion, the rigidity is high and the amount of bending is reduced, and the slab vibration is less disturbed as compared with the conventional beam structure made of pure steel frame.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view showing an embodiment of a joint structure of a girder and a girder according to the present invention. FIG. 1 is a view taken along the line I--I of FIG. 4, FIG. 2 and FIG. View II-II, along with view III
-III and 4 are plan views showing a frame structure of a building to which the present invention is applied, Fig. 5 is a front view thereof, and Fig. 6 is a partially longitudinal front view showing another embodiment of the present invention, FIG. 7 and FIG. 8 are flexural diagrams and bending stress diagrams of the structure according to the present invention and the conventional structure, respectively. (A) …… Steel beam, (A ′) …… PC beam, (B) ……
Steel beam, (a) …… Steel reinforced concrete part, (7) …… Reinforcing rebar, (8) (8 ′) (8 ″) …… Concrete.

Claims (1)

(57) [Claims] 1. A steel girder composed of a beam steel frame composed of upper and lower flanges and a web, and a steel frame girder integrally formed with the beam steel frame at a beam joint position and having a gusset plate projecting laterally orthogonal to the beam steel frame. A steel-framed reinforced concrete part having a top surface defect equal to the slab thickness is formed at the joint end to the girder, and the girder plate is provided with a gusset plate protruding from the girder joint end face. The opposing gusset plates are joined by high-tensile bolts, and reinforcement bars are arranged over the upper surface of the girder and the upper surface defective portion of the steel-framed reinforced concrete part of the steel beam girder that is arranged on both sides of the girder. Then, a joint structure of a girder and a girder, characterized in that concrete is placed on the upper surface of the steel beam and the girder joint part including the defective portion.