JPH0468169A - Building construction method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a construction method for a building having a beam with a long span and a large cross section, and in which the load of various building parts and shrines is applied to the beam. .

"Prior Art" In recent years, so-called megastructures have been studied as a structural form of buildings. Figure 1θ shows an example of a building in which megas) lacture has been adopted. It consists of a megastructure, which is a gate-shaped frame, and the upper floor is constructed with regular columns 3 and beams 4 on the top of the megastructure, and the lower part of the megastructure has a high degree of freedom. It was designed to provide a large space.

In the building shown in Figure 10, the span of the I lath beam 2 that makes up the megas 1-structure is long, reaching several tens of meters, and the beam length is several meters. It is said that it also extends to When constructing such a building, the truss beam 2 should be curved in one direction in advance. By tensioning the wire 5 strung in a chevron shape with the jacks installed at both ends of the beam 2, a downward preload is applied to the center of the truss beam 2, causing the truss beam 2 to deform so as to become horizontal. As the construction of the upper floor progresses, loosen the wire 5 to release the preload, and when the second floor is completed, the truss beam 2 will automatically become horizontal due to the load. There is.

``Problem to be Solved by the Invention'' By the way, in the building mentioned in 1, since the steel-framed 1-lath beam 2 is used as the long span and large cross-section beam that constitutes the mechanical structural framework core, However, in order to provide sufficient rigidity to the truss beam 2, the amount of steel frames must be enormous, and the number of welding or bolting points must be enormous, which increases construction costs and requires considerable time and effort.

In addition, when constructing the above-mentioned building, as shown in Fig. 1O, the preceding load on the I-Lath beam 2 is applied to the pillar 3 that is erected at the middle of the truss beam 2. For this reason, three layers of the frame were constructed on top of truss beam 2 before applying a preload to eliminate the bulge, but the bulge still remained. The construction of the frame in the second part of the lath beam 2 is extremely difficult because the pillars 3 other than the one located in the center will tilt outward.

The present invention has been made in view of the circumstances described in 1.It is an object of the present invention to provide a construction method suitable for use when constructing a building in which a load is applied to a beam with a long span and a large cross section. purpose.

``Means for Solving the Problem'' The present invention involves constructing a steel frame between columns with a steel frame that is curved upward in the center and applying a downward pre-load to the steel frame to prevent the steel frame from being exposed to a predetermined value. After the steel frame was reduced to a flat surface, vertical members, materials, and top chords were connected to the top of the steel frame to form a lath, and after that, the preceding load on the steel frame was released. Concrete 1 is then poured onto the steel frame to form the lower chord, and a downward pre-load is applied to the formed beam to make it almost horizontal. 17, after that, the preceding load is gradually reduced so that the deflection of the beam in B is within the allowable deflection range while constructing the remaining building members that will be the load to be applied to the beam. be.

``Example'' An example of the present invention will be described below with reference to FIGS. 1 to 9.

FIG. 1 is a partial elevation view showing the framework of a building constructed by the method of the present invention, and the reference numeral 10 in the figure is a long span and large section provided to form a large space 20 below. It is a beam.

This beam 10 basically has a truss structure consisting of a lower chord member 11, a lower chord member 12, a vertical member 13, and a diagonal member 14. As shown in FIG. is a steel-framed reinforced concrete structure (more precisely, JG term covering Type steel pipe concrete 1)
The lower chord member 12, vertical member J3, and material number 4 are all said to be of steel construction.

As shown in FIG.
A column-less large space 20 is formed below the beam 10, which has a width spanning four spans of this building and has five floors. It is now possible to do so. That is, the clasp 10 and pillars 18 and 18 constitute a megastructure, which is a gate-shaped frame for forming such a large space 20 and supporting the frame of the upper floor.

And, at the position of the second side of the lower chord member 11 of this beam 10,
The second floor of the large space 20 is formed, and the upper chord 12
The floor of the upper floor is further formed at the upper surface position, and the lower chord member 11 of this fruit 10 by itself serves as the floor beam for the second floor of the large space 20, and also serves as the floor beam for the vertical floor 1.
3 and the diagonal members 14 serve as the columns and braces for this floor, respectively, and the upper chord 12 itself serves as the floor beam for the upper floor.

In addition, in the vJ1 diagram, numerals 30 and 31 are pillars and beams that are the building blocks other than the megastructure, and these are made of normal steel frames.

An example of the construction procedure for the above building will be explained with reference to FIGS. 3 to 9.

As shown in FIG.
Then, the steel frame 15, which will become the lower part of the beam 10, is assembled.

As shown in the figure, the steel frame 15 is composed of three pieces including a central portion 15a and both side portions 15b, and is curved so that the central portion 15a is displaced in the j1 direction. The peeling dimension d1 is set so that the beam 10 will be approximately horizontal when it finally receives the load of the building, taking into account the rigidity of the truss, the weight of the concrete, etc., as described later. . Further, the vertical member 13 provided at the center of the beam 10 is attached to the center portion 15a of the steel frame 15 in advance.

Then, the steel frame 15 assembled in this way is attached to the column 1818.
It is lifted up by taking the reaction force from the column 18, and is installed between the upper ends of the columns 18, 18, as shown in FIG.

Next, a downward preliminary load is applied to the steel frame 15 constructed as described above, and the bulge is reduced until the bulge dimension becomes a2 (a2<dt). To do this, as shown in Figure 5,
Hydraulic jacks 40 are attached in two directions along the vertical member 13 provided at the center of the steel frame 15, and both ends of the wire 41 are fixed at the joints between the pillars 18 and 18 and the beam 10, and the wire 41 is engaged with the hydraulic jack 40, and the hydraulic jack 40 is moved fr to remove the wire 4.
By pushing and tensioning the center part of the steel frame 1, it is preferable to apply the reaction force downward through the vertical lever 13 to the medium heat part 15a of the steel frame 5. Incidentally, it is also possible to provide a lifting type hydraulic jack like a center hole type jack (J5) and pull the central part of the wire 41 with the hydraulic jack.

In this state, as shown in FIG.
'13, Diagonal member 141. , I: The chord members 12 are each attached to the steel frame 15 to form a truss.

After that, the preceding load applied to the steel frame I5 is temporarily released. As a result, the bulge of the J: sea urchin steel frame 15 (not shown in Fig. 7) becomes larger, or the bulge dimension d3 is equal to the rigidity of the formed truss (it becomes smaller than the bulge dimension d at the beginning of the truss). .

After that, reinforcing bars 16 are arranged outside the steel frame 15 and a formwork is assembled, and then concrete is filled inside the steel frame 15 and concrete is poured outside of it as well. The lower part of the shrine J1 is formed. As a result, as shown in FIG. 8, the beam 10 is formed with a bulge. At this stage, the bulge dimension d of the beam 10 is equal to the weight of the concrete 1. It is smaller than the cutout dimension d3, and of course smaller than the cutout dimension d1 originally given to the steel frame 15. The exposed dimension d at this stage is then applied to the beam 10.

It corresponds to the load of the upper floor frame and other various building parts H, and is set so that the beam 10 becomes almost horizontal by itself when the load is finally applied to the beam 10.

Therefore, after the strength of the concrete 1 is secured, the concrete is raised to a level slightly higher than the level at which the beam 10 is deflected due to construction on the floor above the beam 10 (until it becomes almost horizontal as shown in Figure 9). A preload is applied to the beam 10 via the wire 41 to reduce swelling. After that, the upper floor frame is constructed on top of the beam 10, and various building components are attached, and the wires 41 are gradually loosened according to the load, thereby reducing the preceding load in stages. l
Hold O almost horizontally to '.

As a result of the above, when the upper floor was almost completed, all the preceding loads applied to the beams 10 were released, and the remaining architectural part shrines were installed.
Once assembled, the beam 1o will naturally become horizontal due to the total load of the two-story frame and various building components. Note that the method and means for applying the advance load are not limited to this embodiment, and may be freely adopted in accordance with the frame structure.

In the above-mentioned beam 1O, the lower chord member 11 and the lower chord member 12 ensure sufficient beam dimensions as a whole and obtain sufficient rigidity, thereby creating a large space 20 as described above below the beam 10. Of course, it is possible to secure the lower chord material 11.
is made of steel-reinforced concrete, and the steel frame 15 of the lower chord member 11 is given a bending moment] in the direction opposite to the direction of deflection of the beam lO, so the beam is Compared to the case where the entire structure is a simple truss structure, the amount of steel can be reduced, and steel processing is simplified.
It is advantageous in terms of construction cost and construction time.

Moreover, the lower chord member 11, the upper chord member 12, the vertical member 13, and the diagonal member 1
4 also serve as the beams, columns, and presses of this building, which has the advantage that the frame of the entire building can be simplified.

In addition, in the construction procedure of the above embodiment, when forming a truss, the vertical members 13, diagonal members 14, and upper chord members 12 are assembled after applying a preliminary load to the steel frame 15 to reduce swelling, so that the work is facilitated. It is something that can be done.

In other words, if the truss is assembled with the steel frame 15 still having a large bulge (the bulge dimension a+), the vertical 14 t a will tilt outward, causing the truss to deteriorate. In contrast, in the above case, the truss is assembled after reducing the bulge until the bulge dimension becomes d2, so the vertical +1
' 13 can be erected vertically without any hindrance and the truss can therefore be assembled easily.

In addition, when pouring concrete to the steel frame 15 to form the lower chord member 11, the preceding load applied to the steel frame 15 is temporarily released and the large bulge is returned to a flat state, and concrete is poured in that state. The steel frame 15
The rigidity of the beam 10 can be further increased compared to the case where the lower chord member 11 is formed by pouring concrete with the bulge reduced.

In addition, in order to apply a preliminary load to the steel frame 15 and the beam 1O, an appropriate method can be adopted without being limited to the above embodiment.

In addition, in the above embodiment, the lower chord member 11 of the beam 10 was made of filled-coated steel pipe concrete 1.
It may be a filled steel pipe concrete structure in which only the inside of s is filled with concrete, or it may be a general steel-reinforced concrete structure using a steel frame of any cross-sectional shape, not just a box-shaped steel frame. In addition, the upper chord material 12
, the vertical members 13 and the diagonal members 14 are not limited to steel structures, but may also be steel reinforced concrete structures or steel pipe concrete structures.
It goes without saying that the positions and formats of the vertical members 13 and diagonal members 14 may be changed as appropriate depending on design requirements. Furthermore, the rigidity can be further increased by forming a composite truss structure beam in which a truss or a beam is integrally formed at the upper or lower part of the beam 1O.

In addition, in the above embodiment, the pillar 1 on which both ends of the beam 10 are supported is
8 is made of steel-framed reinforced concrete construction, but it is not necessarily limited thereto. Furthermore, even if the column 18 is made of steel-framed reinforced concrete, concrete pouring for the column 18 is performed using concrete 1/2 for the bottom chord 1 of 910.
It may be done at the same time as pouring. Of course, if a beam with a long span is provided on multiple floors, it may be provided not only at the upper end of the pillar 18, but also in the middle of the pillar. Furthermore, in the above embodiment, the steel frame 15 serving as the lower chord member 11 of the beam 10 is
Although the structure is installed between the upper ends of the pillars 18 using a hair bulge, in cases where the span is relatively small, etc., it is not necessarily necessary to use the lift-as-ue method.

Further, the above embodiment is an example in which the construction method of the present invention is applied to a building in which a large column-free space is provided below the beam, and an upper floor frame is provided above the beam. However, it goes without saying that the present invention is applicable not only to buildings of this type, but also to buildings of various types in general.

"Effects of the Invention" As explained in detail above, the construction method of the present invention has the following effects:
Since we have adopted a truss structure beam with the lower chord made of steel-framed concrete, the amount of steel can be reduced compared to the case of using a simple lath structure beam, and the steel processing has been simplified, reducing construction costs and construction costs. Not only is it advantageous in terms of time and effort, but when constructing the beam, a steel frame with the center section curved upward is erected between the pillars, and the steel frame has a downward leading edge. After applying a load to reduce the bulge to a predetermined bulge, we connected the vertical members, diagonal members, and top chord members to the two parts of the steel frame to form a truss. Vertical trusses can be built vertically without any problems, and trusses can be easily formed. Furthermore, after the preliminary load on the steel frame is released, concrete 1 is poured onto the steel frame to form the lower chord, so that the rigidity of the beam can be sufficiently increased.

[Brief explanation of the drawing]

Figures 1 and 2 show an example of a building constructed by the method of the present invention, with Figure 1 being a partial elevation view of the frame, and Figure 2 being a sectional view of the beam (II of Figure 1). -II line arrow view). FIGS. 3 to 9 are diagrams for explaining an example of the construction procedure of the building described in "1" in the order of steps. FIG. 10 is a perspective view showing a conventional example of a building using a megastructure. 0... Beam, 1... Lower chord member, 2... Lower chord member, 3... Vertical old, 4... Diagonal member, j5... ...Steel frame, 8...Columns.

Claims (1)

[Claims] A steel frame with a curved center section curved upwards is erected between the columns, and a downward preload is applied to the steel frame to reduce the deflection to a predetermined level. Vertical members, diagonal members, and upper chord members are connected to the top of the steel frame to form a truss, and then, after releasing the preceding load on the steel frame, concrete is poured to the steel frame to form the lower chord member, By applying a downward preliminary load to the beam formed as described above, the beam is made almost horizontal,
Thereafter, while constructing the remaining building members that will be the load applied to the beam, the preceding load is gradually reduced so that the deflection of the beam falls within an allowable deflection range.