JPH0711160B2 - Construction method of frame in steel building - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for constructing a frame effectively used in a steel structure with a large span, and particularly, to a column member standing upright to face each other. , A middle pillar that is erected between these pillar members,
After assembling a frame composed of a beam member spanned between the pillar member and the middle pillar, prestressing the beam member by displacing the middle pillar downward or the pillar member upward. SPC (Steel Prestress C)
ontrol) construction method.

"Prior Art" Among steel-framed buildings, for example, in buildings that require a large space to be formed inside, such as factories,
Since the structural members such as beams and slabs have a large span, the truss structure is mainly used for the frame because it is small in deformation with respect to members that receive bending moment and is structurally and economically advantageous. . However, even in these trusses that have been generally used in the past, when the length (span) becomes remarkably large, not only the flexure becomes large, but also the truss with respect to the total weight of the structure. There was a problem that it became uneconomical because of its own weight.

Therefore, in recent years, even in such a steel building, means for introducing prestress to structural members such as roofs, slabs and beams of the building have been proposed. A general method is to dispose a PC steel material on a member (for example, a truss beam) to be introduced and apply a tensile force to the PC steel material to fix both ends thereof.

[Problems to be Solved by the Invention] By the way, in the steel frame structure in which the prestress is introduced as described above, not only the bending thereof can be reduced but also the stress generated in the frame can be reduced. However, in the conventional means for introducing prestress to the frame, first place the PC steel material on the member to which the prestress should be introduced, and then apply tensile force to this PC steel material and apply both ends to it. Fixed, and to introduce prestress to the structural members, temporary scaffolding, gantry, etc. are required when performing the work to introduce prestress, and the workability is poor and the work efficiency should be poor. There were challenges left.

The present invention has been proposed in view of the above circumstances, and an object thereof is to easily introduce prestress into a steel frame structure, which can reduce the construction cost and improve the construction efficiency. It is to provide a method for constructing a frame in a steel frame building.

"Means for Solving the Problem" In order to achieve such an object, the present invention relates to a method of constructing a frame structure for a steel frame building, in which pillar members which are erected opposite to each other and between these pillar members are provided. After assembling a frame composed of a vertically installed center pillar and a beam member bridged between the pillar member and the center pillar, the middle pillar is displaced downward or the pillar member is displaced upward. Thus, prestress is introduced into the beam member, and the displaced middle pillar or pillar member is fixed at the displaced position.

Further, in order to achieve the same purpose, in a method of constructing a frame for constructing a steel-framed building, in a method of constructing an outer wall of a building, a floor slab that is provided inside the wall and serves as a floor of the building. And a core portion which is arranged in the central portion of the floor slab and which supports the floor slab and which is composed of a plurality of middle pillars, and which is installed between the wall portion and the middle pillar of the core portion to support the floor slab. After assembling a frame composed of beam members, prestress is introduced into the beam member by displacing the core part downward or the wall part upward, and the displaced core part or wall part is displaced. You may make it fix at the position made to do.

Then, it is preferable to provide a control means for controlling the displacement amount of the middle pillar or the pillar member to be displaced.

[Operation] In this invention, since the beam member connected to the upper end of the center column is pulled down by displacing the core portion composed of the center column or a plurality of center columns downward, it is attempted to return to these beam members. Occurs, and these reaction forces act so as to cancel the top load of the beam members.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of a frame constructed by the method for constructing a frame in a steel building according to claim 1, and FIG. 2 is a schematic perspective view showing a state in which a roof plate is roofed on the frame. In these drawings, the reference numeral 1 indicates a frame frame assembled by a steel frame.
Is a pair of pillar members erected on the ground G in a state of facing each other.
2,2, a middle pillar 3 standing upright between the pillar members 2,2, and a beam member bridged between the upper ends of the middle pillar 3 and the pillar members 2,2 It is mainly composed of 4,4.
In the illustrated example, a plurality of the frames 1 are arranged in parallel with each other at predetermined intervals and are connected to each other by a connecting beam bridged between the frames 1 and also constitute the frame 1. A roof plate 5 is attached to the upper portions of the beam members 4 and 4 to form a roof of a building (see FIG. 2).

The pillar member 2 is made of, for example, H-shaped steel, and is vertically arranged with its lower end fixed to a foundation on the ground G.

On the other hand, the middle pillar 3 which is erected between the pillar members 2 and 2 is mainly composed of H-shaped steel, and the beam members 4 and 4 are integrally connected to the upper and left ends of the middle pillar 3 through gusset plates or the like. It has become so.

FIG. 3 is a front view showing the details of the lower end of the middle pillar 3, and as shown in the drawing, a bottom plate 3a is attached to the lower end of the middle pillar 3, and the bottom plate 3a is provided on the upper surface of the foundation 6 so as to project therefrom. An insertion hole for inserting the anchor bolt 7 is provided.
The foundation 6 supports the lower end of the center pillar 3 and is formed by concrete into a ground G that faces the lower end of the center pillar 3. In the embodiment, four anchor bolts 7 projecting from the upper surface of the base 6 are provided on the base 6 in parallel with each other at a predetermined interval, and each anchor bolt 7 has its base end. It is embedded in the foundation 6 to prevent it from coming off.

By the way, a control means 10 for supporting the middle pillar 3 and controlling the amount of displacement of the middle pillar 3 is provided at the lower end of the middle pillar 3. The control means 10 includes a pair of hydraulic jacks 11 and 11 arranged on the left and right of the center pillar 3 and these hydraulic jacks 11 and 11.
It is mainly composed of an electric pump 12 for sending pressure oil to the oil pump, and a control unit 13 for controlling these, and a shutout valve 15 and a hydraulic pressure gauge 16 are provided in the middle of the oil supply pipes 14, 14 for sending the pressure oil, respectively. And are connected.

The hydraulic jacks 11 and 11 are arranged between a supporting steel material 17 bolted to the left and right flange plates 3b of the center pillar 3 and a base mortar 18 provided on the ground G to support the upper and lower sides thereof. 20 bolts on each of steel 17 and base mortar 18
Also, the center pillar 3 can be moved up and down by fixing it via the nut 21.

The beam member 4 bridged between the pillar members 2, 2 and the middle pillar 3 is composed of an upper chord member 4a, a lower chord member 4b, and a lattice member 4c connecting the upper chord member 4a and the lower chord member 4b. It is constructed by being assembled into a truss structure, and its both ends are rigidly joined to the pillar members 2 and 2 and the middle pillar 3 to form a pillar member.
It is designed so that it can be integrally attached to 2, 2 and the middle pillar 3. In addition, in the embodiment, the beam member 4 is set to have a larger size from the outer end fixed to the pillar member 2 to the inner end fixed to the middle pillar 3 (see FIG. 1).

Next, with reference to FIGS. 1 to 4, a method of constructing a frame according to an embodiment of claim 1 will be described.

First, the pillar members 2 and 2 and the middle pillar 3 are erected on the ground G at intervals corresponding to the span interval of the beam members 4 and 4 and the beam members 4 and 4 assembled in the truss structure are fixed to the pillar member 2 , 2 and the middle pillar 3, and the beam members 4, 4 are erected between the pillar members 2, 2 and the middle pillar 3 by rigidly joining both ends to the pillar members 2, 2 and the middle pillar 3. To do. When constructing the center pillar 3, the hydraulic jacks 11 and 11 are assembled in advance to the base mortar 18 of the ground G, and when the middle pillar 3 is suspended, the bottom plate 3a of the center pillar 3 is placed on the upper surface of the foundation 6. The protruding anchor bolt 7 is placed through,
Further, by fixing the supporting steel material 17 of the middle pillar 3 to the upper ends of the hydraulic jacks 11, 11, the middle pillar 3 is erected.

When the construction of the frame 1 is completed in this way, next, operate the hydraulic jacks 11, 11 to operate the hydraulic jack 1
The center pillar 3 supported by 1, 11 is displaced downward, prestress is introduced into the beam members 4, 4 by its own weight, and the bottom plate 3a of the middle pillar 3 is
The nut 25 is screwed into the anchor bolt 7 penetrating through to fix the middle pillar 3. Therefore, in the beam members 4 and 4, the stress at the beam member inner end is reduced in accordance with the introduction of this prestress,
Maximum moment becomes small. This result is also clear from FIG.

Fig. 4 (a) shows the bending moment diagram of frame 1 solved by the evenly distributed load before the introduction of pre-stress, and Fig. 4 (b) shows that the pre-stress was introduced into frame 1 by lowering the center column 3 by δ cm. Bending moment diagram at the time of
Figure (c) shows a bending moment diagram that combines these. As is clear from these figures, when the prestress is introduced into the frame 1, the maximum bending moment at the inner ends of the beam members 4 and 4 becomes small, and the stress distribution is in accordance with the beam strain of the beam members 4 and 4.

That is, in such a structure of the frame 1, the pillar member
When the beam members 4, 4 are built in 2, 2 and the middle pillar 3, the moment distribution shown in Fig. 4 (a) occurs in the beam members 4, 4, but the middle pillar 3 is pulled down. At the stage, a reaction force that tries to return to the beam members 4, 4 acts, and the stress at the inner ends of the beam members 4, 4 is reduced by this reaction force. Therefore, the moment distribution in this state is as shown in FIG. Therefore, the prestress is introduced into the beam members 4, 4, and the stress generated in the beam members 4, 4 is reduced by the effect of the force offsetting the overlaid load on most of the beam members 4, 4. The bending of the beam members 4 and 4 is reduced, and the weight of the beam members 4 and 4 can be reduced at the design stage.

That is, according to the frame construction method of this embodiment, the frame 1
Since the prestress is introduced into the beam members 4 and 4 by pulling down the center pillar 3 after assembling the prestress, it is possible to introduce the prestress into the frame 1 without using PC steel material and improve its workability. It can be improved and the work period can be shortened. If prestress is introduced by pulling down the center pillar 3, the maximum moment at the inner ends of the beam members 4 and 4 can be reduced, so that the weight of the member can be reduced, which results in a large span frame structure. It will be possible to economically construct steel-framed buildings.

Regarding the method of constructing the frame described above, the central column 3 was pulled down with the values shown in Table 1, and the measured and analyzed values of the moment by the strain gauge were blotted as shown in FIG.

As is clear from this figure, the measured value and the analytical value are close, confirming the effect of introducing prestress.

The details of the construction method of the frame of the present invention, the shape of the frame to be constructed, and the like are not limited to the illustrated examples, and can be appropriately changed without departing from the concept of the invention. As an example, in the embodiment, in order to displace the middle pillar 3, the hydraulic jack 11 provided at the lower end of the middle pillar 3 is used. However, this is provided at the upper end of the middle pillar 3 and the upper end of the middle pillar 3 is provided. Needless to say, the beam members 4, 4 may be directly displaced by means of the above, or the displacement amount of the center pole 3 may be controlled by means other than the hydraulic jack 11.

Further, in the above-described embodiment, the center pillar 3 is displaced downward,
While the pre-stress was introduced to the beam members 4 and 4, the center pillar 3 was fixed by the nut 25, but the hydraulic jacks 11 and 11 were controlled by the computer so that the position of the center pillar 3 acted on the frame 1 ( The vertical stress, the horizontal force, etc.) can be changed more effectively to reduce the internal stress of the frame, and economical construction can be realized.

FIG. 6 shows an example in which the present invention is carried out based on such a premise, and a coil spring for urging the middle pillar 3 upward is provided between the bottom plate 3a of the middle pillar 3 and the upper surface of the foundation 6. 30 are interveningly arranged.

According to such a method, when the center pillar 3 is jacked down, it is urged upward by the coil spring 30 and the position of the center pillar 3 is displaced according to the magnitude of the top load.
For the forces acting on the frame 1 (vertical force, horizontal force, etc.),
It has the advantage that it can be self-controlled continuously.

In addition, in the said Example, although the method of introduce | transducing the prestress to the beam members 4 and 4 by lowering the center pillar 3 was described, in this invention, the center pillar 3 is made into the fixed state and the pillar member is kept. The prestress may be introduced into the beam members 4 and 4 by raising 2 and 2 upward. In this case, it goes without saying that the control means 10 is arranged at the lower ends of the pillar members 2, 2 and the displacement of the pillar members 2, 2 is controlled by this control means 10.

Next, an embodiment of the present invention according to claim 2 will be described with reference to FIGS. 7 to 9.

In these drawings, what is denoted by reference numeral 40 is the frame of this embodiment, and this frame 40 is provided inside the wall portion 41 that constitutes the rectangular outer wall of the steel frame building and inside this wall portion 41. A floor slab 42 that serves as a floor of a building, and a core portion 44 that is composed of a plurality of (four in the illustrated example) middle pillars 43 arranged in the center of the floor slab 42 and supporting the floor slab 42. It is configured as a main body, and in the illustrated example, such a frame 40 is provided in a plurality of layers in the vertical direction (see FIG. 8).

The wall portion 41 is a pillar member composed of four main pillars 45 standing upright at four corners of the building and an outer pillar 46 standing upright between the main pillars 45, and between the pillars 45, 46. Is mainly composed of a large beam 47 connected to, and the floor slab 42, a beam member 48 connecting the outer pillar 46 and the middle pillar 43, and a connecting beam 49 connecting the middle pillars 43. A support beam 50 extending in two directions is incorporated in an inner space surrounded by the wall portion 41.

Next, a method of constructing the frame of the embodiment according to claim 2 will be described. First, the frame 40 is assembled in order from the lower layer. The erection of the frame 40 that constitutes each layer is such that a main pillar 45 and an outer pillar 46 are erected to assemble the wall portion 41, and a middle pillar 43 is erected at the center position of the building. Pillar 45,
Beam members (large beam 47, beam member 48, etc.) between the outer pillar 46, the middle pillar 43, etc.
It is carried out by bridging the connecting beam 49, the supporting beam 50, etc.). In addition, at the lowermost end of the middle pillar 43, the middle pillar 43 as described above.
Needless to say, the control means 10 for controlling the amount of displacement is incorporated, and the four center pillars 43 are supported by the hydraulic jacks 11 forming the control means 10.

Then, when the frame 40 is assembled in this way, the control means 10 incorporated at the lower end of each middle pillar 43 is operated to displace the core portion 44 downward, and the beam member 48 for supporting the floor slab 42.
Pre-stress is introduced to fix the core portion 44 at the displaced position. Therefore, the frame 40 is shown in FIG.
Two bending moments as shown in the bending moment diagram (b) are combined to generate a moment distribution as shown in FIG.

However, according to the method of constructing the frame 40, the prestress can be three-dimensionally introduced into the frame of the multi-storey building by pulling down the core portion 44 located at the center of the building. It has the advantage of being able to economically construct large span frames in multi-storey buildings.

Note that, also in the method of constructing such a frame, as described in the previous embodiment, the position of the core portion 44 is changed by controlling the control means 10 with respect to the force acting on the frame 40. It goes without saying that it is also possible to adopt a method of appropriately reducing the stress and continuously controlling the self. Further, the present invention is not limited to the illustrated examples shown in FIGS. 7 to 9, and the details and the shape of the frame to be constructed can be appropriately changed without departing from the idea of the invention. Needless to say.

Furthermore, in the invention method of this embodiment, the means for introducing the prestress to the beam member 48 by displacing the core portion 44 downward has been described, but the core portion 44 is fixed and the surrounding wall portion 41 is fixed. The same prestress may be introduced into the beam member 48 by displacing it upward.

Further, as a modified example of the above-described construction method of the frame, for example, as shown in FIG. 10, two middle columns 3,3 are provided between the column members 2,2.
By arranging the column members 2, 2 close to the column members 2, 2 and spanning the beam members 4, 4 between these column members 2, 2 and the middle columns 3, 3 to displace the column members 3, 3 downward. Prestress may be introduced into the beam members 4,4. In the figure, reference numeral 50 indicates a support beam that connects the beam members 4, 4.

"Effects of the Invention" As described above, the method for constructing a frame in a steel frame building according to the present invention has the following excellent effects.

The method for constructing a frame according to claim 1, wherein in the method for constructing a frame constituting a steel frame building, pillar members that are erected opposite to each other, and a middle pillar that is erected between these pillar members,
After assembling a frame composed of a beam member spanned between the pillar member and the middle pillar, prestressing the beam member by displacing the middle pillar downward or the pillar member upward. Since it is characterized by fixing the center pillar or pillar member that has been introduced and displaced at the displaced position, prestress can be easily introduced into the steel frame structure and the construction cost can be reduced. It is possible to improve the construction efficiency. Moreover, since the stress generated in the frame can be reduced, the weight of the steel frame can be reduced, and the economical construction of a large span building can be realized.

The method for constructing a frame according to claim 2 is the method for constructing a frame for constructing a steel frame building, wherein a wall portion forming an outer wall of the building and a floor provided inside the wall portion are provided for the building. A floor slab, a core portion composed of a plurality of middle pillars arranged in the central portion of the floor slab and supporting the floor slab, and a floor slab that is erected between the wall portion and the middle pillar of the core portion. After assembling a frame composed of supporting beam members, prestress is introduced into the beam member by displacing the core portion downward or the wall portion upward, and the displaced core portion or wall portion is removed. Since it is fixed at the displaced position, it is possible to easily introduce Presto-S into the frame of a multi-story structure, which has been assembled into a three-dimensional structure, thereby enabling economical construction. be able to.

Further, by providing a control means for controlling the displacement amount of the middle pillar or the pillar member, the position of the pillar is changed with respect to the force acting on the frame, the internal stress is appropriately reduced, and the continuation is continued. There is an advantage that prestress can be self-controlled.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 5 are shown for explaining an embodiment of a method of constructing a frame according to claim 1, and FIG. 1 is a diagram showing a frame in a constructed state. A front view, FIG. 2 is a schematic perspective view showing a state in which a roof plate is roofed on the frame, and FIG. 3 is a front view showing the structure of the control means assembled to the lower end of the center pillar, FIG. 4 (a), (B) and (c) are shown to explain the bending moment of the frame, respectively. Fig. 4 (a) is a bending moment diagram where a uniform load is applied to the beam member, and Fig. 4 (b) is Bending moment diagram when introducing prestress, No. 4
Fig. (C) is a bending moment diagram when these are combined, Fig. 5 is a diagram plotting the measured and analyzed values of the moment by a strain gauge when introducing prestress, and Fig. 6 is a front view showing another embodiment. FIGS. 7 to 9 are shown for explaining an embodiment of a method for constructing a frame according to claim 2, and FIG. 7 is a plan view showing an outline of the frame, and FIG. )
Is a bending moment diagram when prestress is not introduced into the frame, Fig. 8 (b) is a bending moment diagram when prestress is introduced, and Fig. 9 is a bending moment diagram combining these,
FIG. 10 is a plan view showing a modified example of the method of the present invention. G: ground, 1 ... frame, 2 ... pillar member, 3 ... middle pillar,
3a ... bottom plate, 3b ... flange plate, 4, 4 ... beam member, 5 ...
… Roof board, 6 …… Base, 7 …… Anchor bolt, 10 ……
Control means, 11 …… hydraulic jack, 12 …… electric pump, 13
...... Control unit, 14 …… Oil supply pipe, 15 …… Shut-out valve, 16 …… Oil pressure gauge, 17 …… Support steel material, 18
…… Base mortar, 20 …… Bolts, 21,25 …… Nuts, 30 …… Coil springs, 40 …… Frames, 41 …… Walls, 42 …… Floor slabs, 43 …… Middle pillars, 44 …… Cores Part, 45 ...
… Main columns, 46 …… Outer columns, 47 …… Large beams, 48 …… Beam members, 49…
… Connection beams, 50… Support beams.

Claims (3)

[Claims] 1. A method of constructing a frame constructing a steel frame building, comprising pillar members standing upright to face each other, middle pillars standing upright between these pillar members, said pillar members and middle pillars. After assembling a frame composed of a beam member bridged between and, the pre-stress is introduced into the beam member by displacing the middle column downward or the column member upward, and displacement is added. A method for constructing a frame in a steel building, characterized by fixing a central pillar or a pillar member at its displaced position. 2. A method for constructing a frame constructing a steel frame building, wherein a wall portion constituting an outer wall of the building, a floor slab provided inside the wall portion and serving as a floor of the building, and the floor. With a core portion composed of a plurality of center pillars arranged in the central portion of the slab and supporting the floor slab, and a beam member that is installed between the wall portion and the center pillar of the core portion and supports the floor slab. After assembling the frame structure to be constructed, prestress is introduced into the beam member by displacing the core part downward or the wall part upward, and the displaced core part or wall part is displaced at the position. A method for constructing a frame in a steel frame building characterized by fixing. 3. The method for constructing a frame in a steel frame building according to claim 1, wherein the middle pillar or the pillar member to be displaced is provided with a control means for controlling the amount of displacement thereof. .