JP2916587B2 - Construction method of building - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a construction method of a building having a beam having a long span and a large cross section, and to which a load of various building members is applied.

"Conventional technology" In recent years, what is called a so-called megastructure (giant frame) has been studied as a structural form of a building.
FIG. 10 shows an example of a building employing a megastructure, in which a huge portal frame is constructed by four steel columns 1 and a steel truss beam 2 erected between the upper ends thereof. A structure in which the upper floor is constructed by ordinary pillars 3 and beams 4 on the upper part of the megastructure, so that a large space with a high degree of freedom is obtained at the lower part of the megastructure. What was done.

In the building shown in FIG. 10, the span of the truss beam 2 constituting the megastructure is as long as several tens of meters, and the span of the beam is as long as several meters. ing. In constructing such a building, the truss beam 2 is previously provided with a bend so as to be warped upward, and in the middle of construction, as shown in FIG. The truss beam 2 is deformed so that the truss beam 2 becomes almost horizontal by applying a downward precedent load to the central portion of the truss beam 2 by tensioning the wire 5 stretched in a mountain shape by the installed jack. , The wire 5 is loosened to release the preceding load, and the truss beam 2 is naturally leveled by the load when the upper floor is completed.

[Problems to be Solved by the Invention] By the way, in the above-described building, since the steel truss beam 2 is adopted as a beam having a long and long span and a large cross section constituting the megastructure, the truss beam 2 is not used. In order to provide sufficient rigidity, not only does the amount of steel frame become enormous, but also the number of welding or bolt fastening points becomes enormous, resulting in a problem that the construction cost is increased and the construction work is extremely time-consuming.

Further, when constructing the above-mentioned building, as shown in FIG. 10, a precedent load to the truss beam 2 is applied via a column 3 that is erected at the center of the truss beam 2. Therefore, prior to the application of the preceding load to eliminate the peeling, three layers of the skeleton were constructed on the upper part of the truss beam 2, but the truss beam with the peeling still attached Performing construction of the skeleton at the upper part of 2 is extremely difficult because columns 3 other than those located at the center are inclined outward.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a suitable construction method adopted when constructing a building in which a load is applied to a beam having a long span and a large cross section. I do.

"Means for Solving the Problems" The present invention provides a steel frame having a central portion warped upward with a pre-peeled portion interposed between columns, and applies a downward preload to the steel frame to remove the peal. After reducing to the predetermined peeling, vertical material, diagonal material, and upper chord material are connected to the upper part of the steel frame to form a truss, and then, after releasing the preceding load on the steel frame, The lower chord is formed by casting concrete, and the beam formed as described above is subjected to a downward precedent load to make the beam almost horizontal, and then the remaining load to be applied to the beam is applied. The present invention is characterized in that the precedent load is gradually reduced so that the bending of the beam is within the allowable bending range while the building member is being constructed.

Embodiment An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a partial elevational view showing a skeleton of a building constructed by the method of the present invention. In the figure, reference numeral 10 denotes a long span and a large cross section provided for forming a large space 20 thereunder. It is a beam.

This beam 10 basically consists of a lower chord material 11, an upper chord material 12, a vertical
It is of truss structure composed of 13, diagonal material 14,
As shown in FIG. 2, the lower chord 11 is filled with concrete inside the box-shaped steel frame 15,
It is made of steel-framed reinforced concrete (more precisely, filled and coated steel pipe concrete) formed by casting concrete after reinforcing bars 16 are arranged on the outside.
12, vertical member 13, and diagonal member 14 are all made of steel.

As shown in FIG. 1, this beam 10 has both ends of a lower chord material 11 joined to columns 18 and 18 of large sections made of steel-reinforced concrete, and is erected between the upper ends thereof. Have a width spanning 4 spans of this building and 5
A column-free large space 20 through which the layers flow is formed. That is, the beams 10 and the columns 18, 18 form a megastructure that is a portal frame for forming such a large space 20 and supporting the frame on the upper floor.

Then, the floor of the upper floor of the large space 20 is formed at the position of the upper surface of the lower chord material 11 of the beam 10, and the floor of the upper floor is further formed at the position of the upper surface of the upper chord material 12. In this beam 10, the lower chord 11 itself also serves as a floor beam on the floor directly above the large space 20, and the vertical member 13 and the diagonal member 14 themselves also serve as columns and braces on this floor, respectively. The upper chord 12 itself is also used as a floor beam on the upper floor.

In FIG. 1, reference numerals 30 and 31 denote pillars and beams, which are other than the megastructure, which are ordinary steel structures.

An example of a construction procedure of the above building will be described with reference to FIGS.

As shown in FIG. 3, after constructing the frame to the floor of the pillars 18 and 18 and the large space 20, beams are formed on the floor of the large space 20.
Assemble the steel frame 15 to be the lower chord material 11 of the 10. This steel frame 15
As shown in the figure, the center part 15a and the two side parts 15b, 15b are constituted by three pieces, and the center part 15a is peeled so as to be displaced upward. The peeling dimension d ₁ is set so that the beam 10 becomes substantially horizontal when finally receiving the load of the building, taking into account the rigidity of the truss and the weight of the concrete as described later. deep. In addition, a vertical member 13 provided at the center of the beam 10 is attached to the central portion 15a of the steel frame 15 in advance.

Then, the steel frame 15 assembled as described above is lifted up by taking a reaction force from the columns 18, 18, and is erected on the upper end surfaces of the columns 18, 18, as shown in FIG.

Next, a downward leading load is applied to the steel frame 15 erected as described above to reduce the peeling until the peeling dimension becomes d ₂ (d ₂ <d ₁ ). As shown in FIG. 5, a hydraulic jack is attached to the vertical member 13 provided at the center of the steel frame 15.
Attach 40 upward and fix both ends of the wire 41 at the connection between the columns 18, 18 and the beam 10, engage the central part of the wire 41 with the hydraulic jack 40, and operate the hydraulic jack 40. By pushing up the central portion of the wire 41 and tightening, the reaction force is applied to the central portion of the steel frame 15 through the vertical member 13.
It is good to add downward to 15a. In addition, a lifting hydraulic jack is provided like a center hole type jack,
The central portion of the wire 41 may be pulled up by the hydraulic jack.

Then, in that state, as shown in FIG. 6, other vertical members 13, diagonal members 14, and upper chord members 12 are attached to the steel frames 15, respectively.
Form a truss.

Thereafter, the preceding load applied to the steel frame 15 is temporarily released. Thus, although Mukuri steel frame 15 as shown in FIG. 7 is increased, the Mukuri dimension d _3, only the stiffness component of the formed truss initial smaller than Mukuri dimension d _1.

After that, reinforcing steel 16 is arranged outside the steel frame 15 to assemble the formwork, then the concrete is filled inside the steel frame 15 and concrete is poured outside the steel frame 15, and the lower chord material 11 of the steel frame reinforced concrete is formed. Form. As a result, as shown in FIG. 8, the beam 10 is formed in a state in which the beam 10 is peeled. At this stage, the beam dimension d ₄ of the beam 10 is equal to the above-mentioned dimension d _{3 by} the weight of the concrete. becomes smaller, of course smaller than Mukuri dimension d _1, which has been granted to the original in steel frame 15. The peel size d _{4 at} this stage corresponds to the load of the upper-story skeleton and other various building members to be subsequently applied to the beam 10, and the load is finally applied to the beam 10. Is set so that the beam 10 is substantially horizontal by itself.

Therefore, after the concrete strength is secured, the peeling is reduced to a level slightly higher than the level at which the beam 10 due to the construction on the floor above the beam 10 is deflected (until it is almost horizontal as shown in Fig. 9). A preload is applied to the beam 10 via the wire 41 in order to cause the beam to move. After that, the upper-floor skeleton is constructed at the top of the beam 10 and various building members are attached, and the wires 41 are sequentially loosened according to the load to gradually reduce the preceding load, thereby reducing the beam. Keep 10 almost level at all times.

As described above, when the upper floor is almost completed, all the preceding loads applied to the beam 10 are released, and the remaining building members are attached.
Once assembled, the beams 10 are naturally leveled by the total load of the upper floor skeleton and various building components. The method and means for applying the preceding load are not limited to this embodiment, and may be freely adopted in accordance with the frame structure.

In the above-mentioned beam 10, the lower chord material 11 and the upper chord material 12 as a whole ensure a sufficient beam forming dimension and obtain sufficient rigidity.
Of course, the lower chord 11 is made of steel reinforced concrete, and the steel 15 of the lower chord 11 is given a bending moment in a direction opposite to the bending direction of the beam 10, so that the second chord 11 can be secured. Compared to the case where the whole beam has a simple truss structure as shown in Fig. 10, the amount of steel frame can be reduced and the steel frame processing is simplified, which is advantageous in terms of construction cost and labor. Moreover, lower chord 11, upper chord 12, vertical 1
3. Since the diagonal members 14 also serve as beams, columns and braces of the building, there is an advantage that the structure of the entire building is simplified.

In addition, in the construction procedure of the above embodiment, the vertical member 13, the diagonal member 14, and the upper chord member 12 are assembled after applying a precedent load to the steel frame 15 when forming the truss to reduce the peeling. Is what you can do. That is, when assembling a truss with the steel frame 15 having the initial large swelling (scaling dimension d ₁ ), the vertical members 13 are inclined outward and the truss construction Is much more difficult, whereas in the above case,
Since Mukuri dimensions assembled truss from reducing the Mukuri until d _2, it is possible to build uprights 13 vertically without any problem, thus it is possible to assemble the truss easily.

Also, cast concrete on steel frame 15
In forming 11, the prior load applied to the steel frame 15 was once released and returned to a state with large peeling, and concrete was poured in that state, so the peeling of the steel frame 15 was reduced. The rigidity of the beam 10 can be further increased as compared with the case where the lower chord material 11 is formed by casting concrete in the state.

In addition, in order to apply a preceding load to the steel frame 15 and the beam 10, an appropriate method can be adopted without being limited to the above-described embodiment.

Further, in the above embodiment, the lower chord material 11 of the beam 10 is made of a filling-coated steel pipe concrete, but this may be a filled steel pipe concrete structure in which concrete is filled only inside the steel frame 15, or a box. It is also possible to use a general steel-framed reinforced concrete structure using a steel frame having an arbitrary cross-sectional shape without being limited to the steel frame. In addition, upper chord material 12, vertical material 1
3, the diagonal members 14 are not limited to steel members, but may be steel frame reinforced concrete or steel pipe concrete structures.
Needless to say, the position and format of 14 may be appropriately changed according to design requirements and the like. Furthermore, by using a truss or a beam of a composite truss structure in which a beam is integrally formed above and below the beam 10, rigidity can be further increased.

Further, in the above embodiment, the pillars 18 on which both ends of the beam 10 are supported are provided.
Is made of steel-framed reinforced concrete, but is not necessarily limited thereto. Further, even when the column 18 is made of a steel-framed reinforced concrete structure, the concrete placing on the column 18 may be performed simultaneously with the concrete placing on the lower chord material 11 of the beam 10. Needless to say, the beam 10 may be provided in the middle of the pillar when a plurality of long span beams are provided not only at the upper end of the pillar 18 but also on a plurality of floors. Furthermore, in the above embodiment, the steel frame 15 that becomes the lower chord material 11 of the beam 10 is lifted up and erected between the upper ends of the columns 18, but when the span is relatively small, the lift-up method is not necessarily used. Absent.

Further, the above embodiment is an example of a case where the construction method of the present invention is applied to a building in which a large pillarless space is provided below the beams and a skeleton of an upper floor is provided above the beams. However, it goes without saying that the present invention can be applied not only to such forms of buildings, but also to various types of buildings in general.

[Effects of the Invention] As described in detail above, in the construction method of the present invention, since the lower chord material employs a truss structure beam made of steel concrete, a simple truss structure beam is adopted. In addition to reducing the amount of steel frames and simplifying steel frame processing, it is advantageous not only in terms of construction cost and labor, but also when constructing the beams, the center part must be bent upwards in advance. A steel frame with a hole is installed between the pillars,
After applying a downward preload to the steel frame to reduce the peeling to a predetermined level, the vertical, diagonal and upper chords were connected to the upper part of the steel to form a truss. The vertical members can be erected vertically on the upper part of the steel frame without any trouble, so that the truss can be easily formed. Further, after that, after releasing the preceding load on the steel frame, concrete is cast on the steel frame to form the lower chord material, so that the rigidity of the beam can be sufficiently increased.

[Brief description of the drawings]

1 and 2 show an example of a building constructed by the method of the present invention. FIG. 1 is a partial elevational view of the skeleton, and FIG. 2 is a sectional view of a beam (II in FIG. 1). -II line arrow view). 3 to 9 are diagrams for explaining an example of the construction procedure of the building in the order of steps. FIG. 10 is a perspective view showing a conventional example of a megastructure building. 10 ... beam, 11 ... lower chord material, 12 ... upper chord material, 13 ... vertical material, 14 ... diagonal material, 15 ... steel frame, 18 ... pillar.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-44569 (JP, A) JP-A-3-122333 (JP, A) JP-A-3-107048 (JP, A) JP-A-58-58 91274 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) E04G 21/14 E04B 1/30 E04B 1/18

Claims (1)

(57) [Claims] 1. A steel frame having a central portion warped upward and having a preliminarily peeled shape is erected between pillars, and a downward precedent load is applied to the steel frame to reduce fluffing to a predetermined value. After that, the vertical, diagonal and upper chords are connected to the upper part of the steel frame to form a truss, and then the precedent load on the steel frame is released and concrete is cast on the steel frame to lower the chord. Forming the beam, applying a downward precedent load to the beam formed as described above, making the beam substantially horizontal, and then constructing the remaining building member that will be the load applied to the beam, A method for constructing a building, characterized in that a preceding load is gradually reduced so that the deflection of the preform is within an allowable deflection range.