JP2555796B2 - Underground construction method using hollow PC columns - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing an underground structure by connecting hollow PC columns.

[0002]

2. Description of the Related Art As an underground construction method of this type, for example, there is a method shown in FIG. That is, in this conventional underground construction method, first, the vertical shaft 1 is excavated, concrete is poured into the bottom of the vertical shaft 1, and the cast-in-place pile 2 is constructed. Then, all the PC columns 3 are built in the vertical shaft 1 according to the number of underground floors and sequentially connected. In addition, the all-PC columns 3 are columns in which concrete is precast in advance in a factory or the like. Next, excavate and remove the earth and sand around the pillar 3,
The flat slab 4 is built between the connecting portions of the PC columns 3.

[0003]

However, in such an underground construction method using the conventional PC pillar 3, since the PC pillar 3 is solid, the post-casting beam, that is, the flat slab 4 in this case is joined. Becomes difficult and the strength of the joint cannot be obtained.

Further, by using the cast-in-place pile 2 in combination, it is necessary to insert the pillar 3 into the pile 2 before the concrete of the pile 2 is hardened, and to fix the pillar 3 significantly. Will end up.

Further, since all the solid PC columns 3 are used, there are various problems that the weight is significantly increased and the column length is limited.

In view of the above-mentioned conventional problems, the present invention is to provide a hollow PC column in which a PC column is formed in a hollow shape so that the post can be easily installed and the post-beam can be joined easily and firmly. The purpose is to provide an underground construction method using.

[0007]

In order to achieve the above object, the present invention connects hollow PC columns and corrugated iron plate joints through which beam connecting bars penetrate alternately according to the number of floors of an underground building. The column pre-assembly, place the column pre-assembly in the upper part of the excavation part of the cast-in-place pile to be built, and then pierce the hollow part of the column pre-assembly. A tremy pipe for placing concrete is arranged, a cast-in-place pile is constructed using this tremie pipe, and concrete is placed inside the column preliminary assembly.

[0008]

As described above, in the underground construction method using hollow PC columns according to the present invention, the column preliminary assembly consisting of the hollow PC columns and the corrugated steel plate joint is installed and the tremie pipe is inserted. Since the concrete is placed inside the cast-in-place pile and the column preliminary assembly, the cast-in-place pile and the column preliminary assembly can be constructed by continuous concrete at once. Therefore, the pillar can be easily installed on the cast-in-place pile and the connection between the pillar and the pillar can be strengthened.

Further, since the corrugated iron plate joint connected between the hollow PC columns is penetrated by the beam connecting bar, the beam connecting bar is connected to the beam connecting bar of the post-strike beam to connect the post-strike beam. The joint can be simplified and the strength of the joint can be increased in combination with the corrugated iron plate joint.

Further, since the PC column is hollow,
Weight reduction can be achieved and each hollow PC column can be set long.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 and 2 are an underground construction method showing an embodiment of the present invention, FIG. 1 is a vertical sectional view showing an essential part of the present invention, and FIG. 2 is an enlarged sectional view taken along line AA in FIG. is there.

That is, in the underground construction method of this embodiment, first, the required mountain retaining work is performed, and the inside of the mountain retaining is excavated to the required depth. Next, a vertical shaft 12 having the diameter of the cast-in-place pile 10 to be constructed is excavated on the ground. On the other hand, the hollow PC columns 14 and the corrugated iron plate joints 16 are alternately connected according to the number of floors of the underground building to form the column preliminary assembly 18.

By the way, the hollow PC column 14 is manufactured in advance in a factory or the like using a centrifugal concrete molding machine (not shown).
As shown in FIG. 2, it is formed as a hollow body having a rectangular cross section.
As shown in FIG. 2, the hollow PC column 14 has a plurality of reinforcing bars 20 arranged in the longitudinal direction embedded in the thick portion thereof at substantially equal intervals in the circumferential direction, and the outer sides of the reinforcing bars 20. A plurality of surrounding hoop muscles 22 are embedded at substantially equal intervals in the length direction.

On the other hand, the corrugated iron plate joint 16 is formed as a hollow body in which an iron plate is bent along the outside of the hollow PC column 14 into a rectangular cross section, and its side surface is formed in a concavo-convex shape in the longitudinal direction. And it is as a waveform. The corrugated iron plate joint 16 is integrally provided with a beam connecting line 26 penetrating in the connecting direction of the beam 24.

In the column preliminary assembly 18 thus constructed, the column rebar cage 30 including the column main bars 28 and the like.
Is inserted.

Next, the pillar rebar cage 30 is suspended as shown in FIG. 1, and in this state, a tremie tube 32 penetrating through the hollow portion S of the pillar preliminary assembly 18 in the central axis direction is inserted. Concrete is poured into the pile 10 and the hollow portion S in the vertical shaft 12 through the tremie pipe 32.

The lower end of the tremie pipe 32 projects further downward than the lower end of the column preliminary assembly 18, and the concrete from the tremie pipe 32 fills the bottom of the shaft 12 and then the column preliminary It enters into the hollow portion S of the assembly 18 and fills the hollow portion S. Therefore, the cast-in-place pile 10 and the hollow PC columns 14 can be continuously poured in concrete at one time, and the column 1 for the cast-in-place pile 10 can be used.
4 can be installed easily and the connection between the pile 10 and the pillar 14 can be strengthened. When the concrete placed in the hollow portion S of the column preliminary assembly 18 hardens, the reinforcing bar 20 and the column main bar 28 embedded in the hollow PC column 14 form a lap joint, and each hollow PC The columns 14 can be reliably coupled to each other.

In this embodiment, as the post-beam 24, a beam 24a for laying a floor on the second basement floor and an underground 1
A beam 24b for laying the floor on the first floor and a beam 24c for laying the floor on the first floor above the ground are provided.

Next, in constructing the post-strike beams 24a and 24b, first, the beam connecting bar 26 penetrating the corrugated iron plate joint 16 and the beam main bar 34 of the post-cast beam 24 are connected to the rebar joint 36.
Connect through. Then, the periphery of the beam main bar 34 is covered with a mold frame (not shown), and concrete is poured therein.
In addition, when constructing beams and floor slabs, PC beams and half P
A C beam may be adopted.

By the way, when joining the post-stretched beams 24a and 24b to the column preliminary assembly 18, the beams 2
Since the beam connecting bar 26 penetrates through the corrugated iron plate joint 16 that joins the 4 a and 24 b, the beam connecting bar 26 is connected to the beam connecting bar 26.
The connection of the post-stretched beams 24a and 24b is simplified by connecting No. 4, and the strength of the joint portion of the post-stretched beams 24a and 24b is combined with the fact that the outer side of the corrugated iron plate joint 16 is made uneven. Can be significantly increased.

Further, since the PC columns 14 are formed hollow, weight reduction of the columns can be achieved, and accordingly, each hollow PC column 1 can be achieved.
4 can be formed long. Also, this increases the distance between the post-strike beams 24a, 24b, 24c,
In addition, the space of each basement can be raised.
Although the hollow PC column 14 has a rectangular cross section in this embodiment, it is needless to say that the hollow PC column 14 may have a circular cross section or a polygonal cross section.

[0022]

As described above, in the underground construction method using the hollow PC columns of the present invention, the hollow PC columns and the corrugated iron plate joints having the beam connecting bars penetrating are alternately connected. Assemble the column pre-assembly, and in this state, place the concrete in the cast-in-place pile and the column pre-assembly through the tremie pipe that penetrates the hollow part of the column pre-assembly. As a result, these cast-in-place piles and each hollow PC pillar are
It can be constructed continuously at once with concrete. Therefore, the pillar can be easily installed on the cast-in-place pile and the connection between the pillar and the pillar can be strengthened.

Further, since the beam connecting bar penetrates through the corrugated iron plate joint, the beam main bar of the post-strike beam can be connected to the beam connecting bar. Therefore, the joining of the post-cast beams can be simplified, and the strength of the joining portion can be greatly increased in combination with facilitation of transmitting the shearing force of the beam end as the corrugated iron plate joint.

Furthermore, since the PC column is hollow, the weight of the column can be reduced. Therefore, each PC pillar can be formed long, and various excellent effects can be obtained that the floor height can be increased.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along the line AA in FIG.

FIG. 3 is a longitudinal sectional view of a main part showing a conventional underground construction method.

[Explanation of symbols]

10 Cast-in-place pile 12 Vertical shaft 14 PC column 16 Corrugated steel plate joint 18 Column preliminary assembly 20 Reinforcing bar 22 Hoop bar 24 Post-cast beam 26 Beam connecting bar 28 Column main bar 30 Column rebar cage 32 Tremie pipe 34 Beam main bar

Claims (1)

(57) [Claims] 1. Hollow PC columns and corrugated iron plate joints that penetrate beam connecting bars are alternately connected according to the number of floors of an underground building to form a column preliminary assembly, and this column preliminary assembly is carried out. Build the body by locating it at the upper part of the excavation part of the cast-in-place pile to be constructed, and then piercing the hollow part of this column pre-assembly body and placing the tremie pipe for concrete placement. Hollow P characterized by constructing a cast-in-place pile by using it and placing concrete inside the column preliminary assembly.
Underground construction method using C pillar.