JPH08291526A - Construction method for underground structure - Google Patents

Abstract

PURPOSE: To improve work efficiency, shorten the term of works and not to damage the environment of the periphery of a construction field by adopting a reverse driving method and adopt a PC member as a constructive member. CONSTITUTION: An earth retaining wall 1 is built on the underground outer peripheral ground where an underground structure is constructed, a cast-in-place concrete pile 3 is made and an intermediate pile for supporting an underground structure is installed on the pile 3 to perform underground primary digging. Subsequently, hollow PC columns (a) are erected on the intermediate piles, a PC beam is stretched between the columns (a), and then a floor material also serving as a form is laid between the beams. Reinforcing bars are arranged on the floor material to place floor concrete integrally with the hollow part of the hollow PC column (a), and digging is performed to the foundation ground to construct a foundation and construct a lower column 9 for supporting the foundation and the PC column (a).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing an underground structure.

[0002]

2. Description of the Related Art When constructing a structure having an underground structure part, in order to prevent the collapse and subsidence of the underground surrounding part of the underground structure part, the surrounding ground is piled up and the pile land business is applied to the soft ground. Performed primary excavation from the above-ground part, supported by horizontal support using ridges and cut beams on the mountain retaining wall, excavated to the specified foundation ground, and carried out foundation construction to construct the skeleton to the upper part Then, it will be further built on the ground.

In addition to the above-mentioned construction method, there is a reverse driving method in which underground construction and ground construction work are simultaneously performed. This reverse driving method was carried out on the ground part, after carrying out mountain retaining on the surrounding ground and piling ground for soft ground, omitting upset for mountain retaining and horizontal support work using cutting beams. It is to build from the top slab to the lower layers, and finally to build the foundation.

[0004]

[Problems to be Solved by the Invention] When constructing an underground structure, the construction method should be examined according to the scale of construction and location conditions, and the optimal construction method should be used. Since there is no such thing, most of the above-mentioned formwork assembly, rebar processing and assembly is performed by each professional at the site, so much work time is required, and noise and vibration associated with the loading and unloading of construction materials are required. However, there is a problem that the environment around the construction site is damaged, and that work in a narrow underground place involves heavy labor and adversely affects the workability.

The present invention has been proposed in view of the above-mentioned problems of the prior art. The object of the present invention is to employ a reverse construction method and industrial products as constituent members,
The point is to improve workability, shorten the construction period, and provide a method for constructing an underground structure that does not damage the environment around the construction site.

[0006]

[Means for Solving the Problems] In order to achieve the above object, according to the method for constructing an underground structure according to the present invention, a mountain retaining wall is constructed on the underground outer ground where the underground structure is to be constructed, and it is cast on site. While constructing concrete piles, installing intermediate piles that support underground structures on the piles and performing primary underground excavation, then standing hollow precast concrete columns on the intermediate piles and precast concrete between the precast concrete columns. After erection of the beams, a formwork / floor material is erected between the precast concrete beams, and reinforcing steel bars are laid on the formwork / floor material to pour floor concrete integrally with the hollow parts of the hollow precast concrete columns. Along with that, the foundation is constructed by excavating to the foundation ground, and the lower pillar that supports the foundation and the hollow precast concrete pillar is constructed. A.

According to the second aspect of the present invention, the hollow precast concrete column has a beam length shorter than the column height corresponding to one floor, and at the top of the column, the column bar that is joined to the upper frame is extended, and at the bottom end of the column. Is a structure in which a column bar connected to the lower frame is extended, and concrete is poured integrally with the intermediate pile through a cavity provided in the center of the column cross section.

[0008]

According to the present invention, as described above, a mountain retaining wall is constructed on the underground outer ground where the underground structure is to be constructed to prevent the surrounding ground from collapsing, a cast-in-place concrete pile is constructed, and the underground structure is constructed. After installing the intermediate pile to support the in-situ concrete pile and performing the underground primary excavation, the hollow precast concrete pillar is erected on the intermediate pile, and the precast concrete beam spans between the hollow precast concrete pillars. After constructing the basement and beam in the basement floor in this way, erection of the floor material that also serves as the formwork between the precast concrete beams, and reinforcing reinforcing bars are laid on the floor material that also serves as the formwork, and the floor concrete is hollowed. On-site assembly of most underground construction work with factory-manufactured components by placing them integrally with the hollow part of the precast concrete columns The underground construction is efficiently constructed by the excavation process to the foundation ground, the foundation construction process after excavation, and the process of constructing the foundation and the lower pillar supporting the hollow precast concrete pillar. .

According to the second aspect of the present invention, the hollow precast concrete column has a beam formation shorter than the height corresponding to one floor and the column reinforcement extends from the column top. Therefore, the upper skeleton constructed later is constructed. Can be joined to, and the lower part also extends the columnar muscles and can be joined to the lower frame. Then, by placing concrete in the hollow portion, structural performance as a pillar can be obtained, and further, concrete in the hollow portion and the intermediate pile support the upper structure by adhesion friction.

[0010]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows a building structure A constructed by the method of the present invention. The building structure A has an underground structure B, and the underground structure B is composed of a foundation K, a pillar C, a beam G, a floor S, and an outer wall W. ing.

FIG. 2A shows an underground building B constructed by industrialized building members. Hollow precast concrete columns (hereinafter referred to as hollow PC columns) a and precast concrete beams (hereinafter referred to as PC beams) b. , A precast concrete beam (hereinafter referred to as a PC beam) c and a floor material d. Figure 2 (b) is a hollow PC column. The beam height is made shorter than the column height corresponding to one floor, and the column reinforcement a ₁ extending from the top of the column to the fixing floor extends from the top of the column and is joined to the lower cast-in-place column. The column rebar a ₁ extends, and the central portion of the column cross section is a hollow portion a ₂ .

In constructing the underground structure B, a mountain retaining wall 1 is built on the outer ground D for constructing the underground structure B, a cast-in-place concrete pile 3 is formed from the ground ground D, and an upper structure is formed on the pile 3. An intermediate pile 4 for supporting an object is installed and underground primary excavation is performed. Reference numeral 5 in the figure denotes a root excavation bottom of the primary excavation. (See FIG. 3 (A)) Next, a waste concrete 6 for temporarily supporting the hollow PC pillars a is provided on the root excavation bottom 5 of the primary excavation, the intermediate pile 4 is penetrated, and the hollow PC pillars a are inserted in the intermediate pile 4. Standing up, a PC beam b is installed between the hollow PC columns a, a PC beam c is installed between the PC beams b, and a floor material d that also serves as a formwork is installed, and reinforcing reinforcing bars are laid in the formwork. Then, the same floor material and the hollow portion a ₂ of the hollow PC pillar a
Top concrete slab 7
To build. (See FIG. 4) Further excavating to the foundation ground, constructing the foundation K on the cast-in-place concrete pile 3, and constructing the foundation K and the lower pillar 9 supporting the hollow PC pillar a on the pile 3 to construct an underground structure. To build. (Refer to FIG. 5) FIG. 3B shows another embodiment of the present invention, in which the column base is excavated to the upper part of the foundation during the first excavation, and the excavated portion 5 ′ is provided with waste concrete, After that, the same steps as those in the above-mentioned embodiment can be performed.

In this case, the lower column 9 of the foundation and the hollow PC column can be omitted, and the site work can be further reduced and the work efficiency can be improved. 6 shows the details of the lower structure,
Reference numeral 10 is a foundation footing constructed on the pile 3, and 12 is concrete in the hollow portion of the hollow PC column a. Although the floor material d that also serves as the formwork is used for the floor on the first floor, for example, a floor construction method in which cast-in-place concrete is cast on a half-PC board or a PC board may be used. In the figure, F ₂ is the basement floor.

In this way, the underground construction section is constructed of hollow PC columns a and P.
Since it can be constructed by using industrialized members by using C beam b, PC beam c, and floor that also serves as a formwork, it does not require a professional worker and can work in a narrow underground space. Disappear.

[0015]

EFFECTS OF THE INVENTION According to the present invention, an intermediate pile for supporting an underground structure is installed on a cast-in-place concrete pile constructed on the bottom bottom of the inner circumference of the mountain retaining wall as described above, and primary excavation is performed to the intermediate pile. Standing up using the hollow part of hollow PC pillars, PC beams are erected between the hollow PC pillars, and reinforcement concrete bars are laid on the form and floor material erected between the PC beams, and floor concrete is placed. Then, the same poured concrete is integrated with the hollow PC column through the hollow portion to achieve integration of the column and floor.

Further, according to the present invention, the pillar, the beam, the beam, and the floor material also used as the formwork are composed of PC members produced in the factory, and are brought into the field and constructed by the erection machine, so that the formwork is assembled and disassembled. The work is labor-saving because there is no rebar processing and assembly, workability is improved, and construction pollution that affects neighboring areas due to construction noise is eliminated. According to the invention of claim 2, the hollow PC column has a beam length shorter than a column height corresponding to one layer, and a column bar is extended to a column top portion and a column lower end portion to reliably join the upper frame and the lower frame. In addition, it can be rigidly joined to the intermediate pile supporting the underground structure through the hollow portion provided in the hollow portion.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an underground structure constructed by the method of the present invention.

FIG. 2A is a perspective view of an underground structure constructed by the method of the present invention, and FIG. 2B is a perspective view of a hollow PC column.

3 (a) and 3 (b) are vertical cross-sectional views showing respective examples of installation and excavation steps of the mountain retaining wall and the intermediate pile in the method of the present invention.

FIG. 4 is a vertical cross-sectional view showing a hollow PC column installation step of an underground structure.

FIG. 5 is a vertical cross-sectional view showing a foundation and a construction condition of a structure of an underground structure.

FIG. 6 is a partially enlarged vertical sectional view of an underground structure.

[Explanation of symbols]

A Architectural structure B Underground structure C Column D Ground F ₁ First floor F ₂ Second floor G Beam K Foundation W Outer wall a Hollow PC column a ₁ Column reinforcement a ₂ Hollow part b PC beam c PC small beam d Floor material 1 Yamadome Wall 2 Root cut bottom 3 Cast-in-place concrete pile 4 Intermediate pile 5 Primary excavation Root cut bottom 5'Excavation section 6 Waste concrete 7 Top slab 9 Lower column

Claims (2)

[Claims] 1. A primary excavation underground by constructing a mountain retaining wall on an outer peripheral ground where an underground structure should be constructed, forming a cast-in-place concrete pile, and installing an intermediate pile supporting the underground structure on the pile. Then, the hollow precast concrete columns are erected on the intermediate pile, and the precast concrete beams are erected between the precast concrete columns, and then the formwork / floor material is erected between the precast concrete beams. Reinforcement reinforcing bar is laid in and the floor concrete is placed integrally with the hollow part of the hollow precast concrete column, and the foundation is constructed by excavating to the foundation ground, and the lower column supporting the foundation and the hollow precast concrete column. A method for constructing an underground structure, characterized by: 2. The hollow precast concrete column has a beam length shorter than a column height corresponding to one level, a column bar extending to the upper frame is extended at the column top, and a lower frame is connected to the column lower end. The method for constructing an underground structure according to claim 1, wherein the concrete reinforcement is formed integrally with the intermediate pile through a hollow portion formed by extending a column bar and provided in a central portion in a cross section of the column.