JPH0730565B2 - Construction method of underground structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is applied to the underground construction method for construction of underground structures, especially for the soft ground, large scale, and deep underground where the reverse construction method is required. It relates to the construction method of structures.

(Prior Art) In a general construction method for an underground structure, temporary shoring is installed on a temporary earth retaining wall, and a temporary pier is installed to perform underground excavation.

However, for large-scale and deep underground excavation on soft ground, it is difficult to construct with the conventional temporary general mountain retaining method, and in many cases the whole building reverse driving method is adopted to ensure safety. In the reverse construction method, for each substructure of the basement floor, the formwork was assembled, the reinforcing bars were reinforced, and the concrete was placed each time.

(Problems to be solved by the invention) As described above, in the conventional construction method, for each substructure work of the underground part, the formwork is assembled, the bar arrangement and the concrete placement are carried out each time, so that it is better than the soft ground. The support is unstable, and if the strength of the upper concrete does not exceed a certain limit, demolition and lower level root cutting cannot be done.Furthermore, the demolished formwork material is once carried out to the upper floor, tidyed up, and after root cutting, again. Work such as moving to the lower floor is complicated.

As a result, the reverse striking work is extremely troublesome, the construction cost is high, and the process is delayed.

(Means for Solving Problems) The present invention has been proposed in order to solve such problems, and the first root cutting is completed between the construction pillars constructed underground. After that, assemble the slab and the beam formwork on the root of the same root and hang them up and down freely on the suspension frame installed on the structure column, and lift the slab and the beam formwork to the floor of the first floor above the ground. The floor slab structure concrete on the first floor above ground is placed on each of the above-mentioned structure columns, and then the second root cutting is performed, and then the slab and the beam formwork are located on the first basement floor. It is hung up to the floor part of the above and installed between the above-mentioned true columns, and the floor beam skeleton concrete of the first basement floor is placed on the above-mentioned formwork, and the same steps as above are repeated thereafter. It relates to the construction method of structures.

(Operation) In the present invention, as described above, after constructing a structured pillar in the ground, the first root cutting is performed, and a large slab and a beam formwork are assembled on the bottom of the root cutting to construct the structured pillar. Suspended vertically to the suspension frame installed in, and hung the slab and beam formwork to the floor of the first floor above the ground, and installed between the structure columns.
Concrete is cast on the formwork to construct the floor beam skeleton on the first floor above the ground.

Then, after performing the second root cutting, the slab and beam formwork were hung down to the floor of the first basement floor, placed between the concrete columns, and concrete was placed on the formwork. , The floor beam structure of the first basement floor.

Hereinafter, an underground structure is constructed by repeating the same steps as above for the required number of basements.

(Examples) The present invention will be described below with reference to illustrated examples.

A continuous underground wall (1) that also serves as a support pile will be constructed on the outer periphery of the structure below, and a true pillar (2) for hanging the below-mentioned formwork will be erected to carry out the first root cutting. . (3) in the figure
Is the first root cutting bottom. (See FIG. 1) In addition, a pillar type and a beam type are incorporated in the underground continuous wall (1) as needed. In addition, in order to shorten the construction period, if the basement work is done at the same time as the above-ground structure work, the column will be a strong pillar for supporting the upper structure. Further, concrete for work is placed on the root cutting bottom (3) by the hardness of the ground.

Next, a large slab and beam formwork (4) are assembled on the root cutting bottom (3) and a steel beam (5) of a work floor for construction (generally the floor beam of the first floor) is connected between the structural columns (2). , And between the same-structured true pillar (2) and the underground continuous wall (1), and as described later, the suspension frame (6) is attached to the true-structured pillar (2) through the steel beam (5). Install. (See FIG. 2) FIGS. 7 and 8 show the details of the suspension frame (6),
At the location where the steel beam (5) on the first floor intersects, between the two opposite sides of the rectangular frame-shaped suspension frame (6a) that intersects the axis of each steel beam (5) at an angle of 45 °. A pair of connecting pieces (6b) which are orthogonal to both sides and which face each other with the true pillar (2) sandwiched therebetween are connected, and between the two connecting pieces (6b) are orthogonal to these, and the true pillar (6b). 2) A pair of connecting pieces (6
c) is connected, and the connecting pieces (6b) and (6c) are provided with a restricting piece (6d) that comes into contact with the side surface of the false column (2) and restricts the horizontal position of the hanging frame.

A PC strand (7) for hanging the slab and the beam formwork (4) is inserted into each side of the suspension frame (6a),
As shown in FIG. 2, the strand (7) is installed at the stage where the suspension frame (6) is installed on the steel beam (5) on the first floor.

Next, the slab and the beam formwork (4) are hung up to the first floor above the ground, and installed between the true construction columns (2) and between the true construction columns (2) and the underground continuous wall (1). 4) Pour the first floor floor beam concrete (8) on top. Next, the second root cutting is performed. (9) in the figure is the same root cutting bottom. (See FIG. 3) Next, the formwork (4) is hung by the suspension frame (6) through the PC strand (7) to the floor of the first basement floor, and between the structure columns (2) and It is installed between the true pillar (2) of the same structure and the underground continuous wall (1), and the concrete beam (10) for the first floor under the ground is placed on the formwork (4). (See FIG. 4) Then, the third root cutting is performed, and the formwork (4) is hung down to the floor part of the second basement floor, and between the structure columns (2) and between the structure columns (2). And the underground continuous wall (1), and the concrete beam (11) for the second floor of the basement floor is placed on the formwork (4). (12) in the figure is the third root cutting bottom. (Fifth
(Refer to the figure) After repeating the same steps as above, the final root cutting is performed as shown in Fig. 6, the foundation concrete (14) is placed on the final root cutting bottom (13), and the post-casting post frame ( 15) Complete construction and overhaul processing to complete the entire process.

(Effect of the invention) According to the present invention, after the construction pillar is constructed in the ground and the first root cutting is completed, the slab and the beam formwork are assembled on the bottom of the root cutting and arranged on the construction pillar. Since it can be hung up and down freely on the suspended mount and can be hung down as the root cutting progresses, it will be installed on the bottom of the root cutting between the above-mentioned structure pillars in the first basement floor, the second basement .. By placing floor girder concrete of each basement floor on each of the formwork, the slab and beam formwork can be diverted for each floor, so that the substructure can be constructed with a single slab formwork. Is simplified.

In addition, basement work is carried out by the suspension base in the structure pillar, the structure pillar on the top of the suspension base is used as a supporting member for the underground structure, and it is possible to perform both ground work and underground work at the same time, Construction efficiency is improved.

[Brief description of drawings]

1 to 6 are vertical cross-sectional views showing the steps of an embodiment of the method for constructing an underground structure according to the present invention, and FIGS. 7 and 8 are plan views of the suspension frame, respectively, and a vertical cross-section. It is a figure. (1) ... Underground continuous wall, (2) ... Structural columns, (4) ... Slabs and beam formwork, (6) ... Suspended frame, (10) ... Underground floor floor concrete structure, (11) … Basement floor concrete floor basement.

Claims (1)

[Claims] 1. A hanging installed between the construction pillars constructed in the ground, after the first root cutting is completed, by assembling a slab and a beam formwork on the roots of the root cutting and installing them on the construction pillars. The slab and the beam formwork are suspended up and down on a stand, and the slab and the beam formwork are hung up to the floor part on the first floor above the ground to install them between the concrete columns. After laying and then performing the second root cutting, the slab and beam formwork are hung down to the floor part of the first basement floor and installed between the concrete columns, and the basement is placed on the formwork. Placing the floor beam frame concrete on the first floor,
Hereinafter, a construction method for an underground structure, which is characterized by repeating the same steps as described above.