JP2637589B2 - Construction method of multi-layer steel frame and steel reinforced concrete structure - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an improved method of erection of multi-layered steel frames and steel reinforced concrete structures.

(Conventional technology) In a multi-story steel frame and a steel-framed reinforced concrete structure serving as a skeleton of a high-rise building or the like, columns and beams are made of H-shaped steel, etc. The skeleton of the structure is erected.

In this type of multi-layer steel frame and steel-framed reinforced concrete structure, the cross-sectional dimension of the beam central part was determined with the prioritized condition that the amount of deflection generated in the beam due to the vertical load was kept as a top priority condition. The cross-sectional dimensions of the entire skeleton member are determined based on the above, and the column members and the beam members are assembled into a rigid structure from the beginning by bolting or welding.

(Problems to be Solved by the Invention) According to the above-described conventional method of designing the member dimensions, each beam member has a very large stress with respect to a vertical load expected from the viewpoint of strength and a horizontal load during an earthquake. It is uneconomical to have a structure with ample room for strength.

The present invention has been proposed in view of the problems of the prior art described above, and the object thereof is to determine the sectional dimensions of structural members safely within a range satisfying the necessary conditions in structural design. An object of the present invention is to provide a method for erection of a multi-layered steel frame and a steel-framed reinforced concrete structure capable of reducing the weight of the structure.

(Means for Solving the Problems) In order to achieve the above object, according to the method of erection of a multi-layered steel frame and a steel reinforced concrete structure according to the present invention, a steel beam to be joined between a plurality of steel columns is connected to a span center. The divided steel beam is divided into two parts so as to maintain a slight gap between the two parts, and the opposite ends of the divided steel beams are joined via a pin joint. Rigidly joined to a steel column in a horizontal position, and then an upward load is applied near the center of the span of the steel beam to cause a predetermined upward bending of the same steel beam. Rigid connection is made between them, and thereafter the upward load is removed.

(Operation) According to the present invention, as described above, the steel beam of each story joined between the plurality of steel members is divided into two so as to maintain a slight gap at the center of the span, and thus divided. The opposite ends of each steel beam are joined via a pin joint, and each end of each of the divided steel beams thus pin-joined is rigidly joined to the steel column in a horizontal posture, thereby forming each layer. A frame of a multi-layered steel structure in which the center of the span of the steel beam is a pin structure is framed.

Therefore, when an upward load is applied near the center of the span of the steel beam in the same frame, the center of the span of the steel beam can be deflected upward by a load that is much smaller than in the case of a rigid structure. it can.

Thus, an upward load is applied to the central portion of the steel beam for each layer, and in a state where the stress change of the steel beam reaches a certain value, for example, a value corresponding to the stress generated by the vertical load at the time of completing the frame, After rigidly connecting the divided steel beams around the pin joint to each other, when the upward load is released, a compressive prestress is introduced into the upper edge of the steel beams and a tensile prestress is introduced into the lower edges. .

Thus, each of the prestresses introduced into the steel beam is
Since the bending in the direction opposite to the stress direction caused by the vertical load applied to the steel beam is given, the bending generated at the center of the span of the steel beam due to the vertical load is reduced, and the bending amount in the same portion is extremely small. Become.

(Example) Hereinafter, the present invention will be described with reference to an illustrated example.

FIG. 1 is a diagrammatic view showing one embodiment of a multi-layered steel frame or a steel reinforced concrete structure constructed by the method of the present invention, wherein (1) is a steel column made of H-section steel or the like. , (2) are steel beams made of H-shaped steel or the like which are erected on the multi-story between the steel columns (1).

The steel beam (2) is divided into two so that a gap is formed at the center of the span, and the opposite ends of the two divided steel beams (2a) are arcuate surfaces (2b) that bulge out toward the partner member. Is formed.

Thus, of the pair of opposed split steel beams (2a),
The base end of one of the front and back joint plates (3) and (3) is welded (w) to the web portion of one of the split steel beams (2a), and the other end is protruded from the distal end of each of the joint plates (3) and (3). Of the divided steel beam (2a), and a joining pin (5) penetrating through a large-diameter connection hole (4) formed in the web portion with the pair of joining plates (3) and (3). ), And a pin joint (6) is formed at the center of the span of the steel beam (2). (See FIG. 2 and FIG. 3.) The pin joints of the steel beam (2) are constructed by various methods other than the above-mentioned embodiment, and the divided steel beam (2a) (2a) However, any configuration may be used as long as the same rotation as the pin is permitted at the center of the span of the steel beam (2).

The opposite ends of the left and right divided steel beams (2a) and (2a) are pin-joined on a gantry, and the other ends of the respective divided steel beams (2a) are bolted to the steel column material (1) in a horizontal posture. The two divided steel beams rigidly connected by welding, welding or the like (2a)
(2a) is suspended and rigidly joined to the steel column (1) in a horizontal posture as described above. (7) in the figure is a rigid joint between the column and the beam.

Next, an upward load P is applied to the vicinity of the center of the span of the beam member (2) by jacking, lifting or the like, and as shown in FIG. 4, a pin joint (6) at the center of the span of the steel beam (2). This causes an upward bending in the vicinity.

At this time, the left and right divided steel beams (2a) rotate about the pin joint (6), so that the center of the span of the steel beam (2) is bent as compared with the case where one continuous beam is bent. Deflection easily occurs with a much smaller load.

In addition, a strain gauge is attached to the steel beam (2) and a steel column (1) to which the beam (2) is rigidly connected. The upward load P is applied by monitoring the change in the applied stress.

As shown in FIG. 5, in a state where the stress exceeds a certain stress corresponding to the stress at the time of the maximum deflection allowed according to the length of the steel beam (2), as shown in FIG. The protruding end is welded (w ') to the web part of the divided steel beam (2a), and a connecting plate (8) is further connected between the arcuate surfaces (2b) and (2b) of the opposed divided steel beam (2a) (2a). Insert and fill gaps and weld to the upper flange (2a ₁ ) (2a ₁ ) and lower flange (2a ₂ ) (2a ₂ ) of each beam (2a) to separate the left and right split steel beams (2a) (2a )

In this state, the steel column (1) and the steel beam (2) have a rigid structure, and when the upward load P is released, the same load P
Due to the stress generated in the steel beam (2), a compressive prestress is introduced into the upper side of the beam (2) and a tensile stress is introduced into the lower side thereof.

Such a construction is sequentially repeated from the lower steel beam (2) in FIG. 1 to the upper steel beam (2), whereby a rigid multilayered steel structure of a required floor is framed.

According to the method shown in the above embodiment, it is possible to safely and easily introduce a prestress into a structural material having a high rigidity that does not easily cause bending, and to assemble a steel frame structure with respect to a vertical load for each floor in the erection stage. The deflection is significantly reduced, and within the limits of the amount of deflection allowed, the cross-section of the steel beam can be reduced and significantly reduced in weight, and the required reverse prestress is easily introduced into the steel column, The cross section of the column can be reduced, and the weight can be reduced.

(Effects of the Invention) According to the present invention, as described above, when erection of a multi-story steel frame structure, the steel beam of each story is divided into two parts so as to maintain a slight gap at the center of the span, and The opposite ends of the beam are joined via a pin joint, and both ends of the pin-joined divided steel beam are rigidly joined to a steel column in a horizontal posture, and the design load is near the center of the span of the steel beam. By applying an upward load in the opposite direction to cause upward bending of the steel beam, and in this state, by rigidly connecting the central portion of the divided steel beam, it is usually very difficult and very difficult to generate bending. In the erection stage, a small amount of load is applied safely and easily to the steel beam having a large rigidity which requires a large load, and the required amount of bending in the reverse direction which is required easily is given in advance. By rigid joining Thus, the required pre-stress in the opposite direction is easily introduced into the steel column erected according to the present invention. As a result, the cross sections of the steel column and the steel beam are reduced, the weight is reduced, and the structure is rational and economical. It is possible to design a simple multilayer steel frame or steel reinforced concrete structure.

[Brief description of the drawings]

1 is a front view diagrammatically showing one surface of a multi-layered steel frame or a steel reinforced concrete structure constructed by the method of the present invention, FIG. 2 is an enlarged front view showing a central pin joint of a steel beam, FIG. 3 is a partially cutaway view taken along the line III-III of FIG. FIG. 4 and FIG. 5 are front views showing the steps of constructing the pin joint. (1) ... steel column, (2) ... steel beam, (2a) ... split steel beam, (3) ... connecting plate, (4) ... connecting hole, (5) ... connecting pin, ( 6) Pin joint, (7) Rigid joint, (8) Link plate, (W) (w ') ... weld, P ... upward load.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshihide Murase Inventor 4-62-22 Kannon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Mitsubishi Heavy Industries, Ltd. Hiroshima Research Laboratory (72) Inventor Takehisa Fukuda 2-10-Nihonbashi, Chuo-ku, Tokyo 4. Inside Toda Construction Corporation (72) Inventor Eiji Kato 2-10-4 Nihonbashi, Chuo-ku, Tokyo Inside Toda Construction Corporation (72) Toshiaki Nakamura 1-3-3 Kyobashi, Chuo-ku, Tokyo Toda Construction Stock In company

Claims (1)

(57) [Claims] 1. A method of erection of a multi-layered steel frame and a steel reinforced concrete structure in which steel beams are joined to a multi-story floor between a plurality of steel columns, wherein the steel beams are held at a center of a span so as to maintain a slight gap. The divided ends of the divided steel beams are divided and joined to each other via pin joints.Each end of the divided steel beams thus pin-joined is rigidly joined to the steel column in a horizontal posture, and An upward load is applied near the center of the span of the steel beam to cause a predetermined upward deflection in the steel beam, and in this state, the divided steel beams are rigidly joined to each other at the center of the span, and then the upward load is applied. A method of erection of a multi-layered steel frame and a steel-framed reinforced concrete structure, characterized by removing slag.