JPH07127080A - Beam and floor constructing method in inversely placing constructing method - Google Patents

Abstract

PURPOSE:To contribute to reduction in construction cost and shortening of a construction period by improving workability by reducing extremely ordinary form work or timbering installing work in a beam and floor constructing method performed when an underground structural building frame of a building is constructed by the so-called inversely placing construction method. CONSTITUTION:Excavation of the ground 3 is performed up to a level L slightly deeper than an under surface of a beam 1 to be constructed, and leveling concrete 4 is placed up to an under surface level of the beam 1 from an excavation surface L, and a form material 5 for the beam is located on a side surface of the beam, and a timbering 6 for a floor is installed on the leveling concrete 4 in an under surface part of the floor 2, and a form material 7 for the floor is supported, and concrete 8 is placed in a part of the beam 1 and a part of the floor 2, and after the concrete 8 reveals strength, the leveling concrete 4 is removed together with the excavation of the ground 3, and the timbering 6 for the floor is removed. Thereby, the form materials 5 and 7 are placed as they are, and can be used for a regular purpose, and the timbering 6 for the floor can be used according to its necessity.

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 a beam and a floor, which is carried out when a substructure of a building is constructed by a so-called reverse construction method.

[0002]

2. Description of the Related Art The following methods are conventionally known as methods for constructing beams and floors having an underground structure by a reverse construction method. Generally, first, the ground is deeply cut to a depth of about 1.0 m to 1.5 m below the beam, the plow work is performed to smooth the root cutting surface, and after discarding concrete, the beam part is placed. Forming molds on the bottom and side surfaces of the base and the bottom of the floor, and these molds are firmly supported by supporting works standing on the aforesaid concrete, and then concrete is placed on the form. After placing concrete hardens and develops strength, first remove the support work, dismantle the formwork, and then remove the discarded concrete along with the root cutting work of the ground and proceed with the construction of the lower floor Is widely known (for example, see Japanese Patent Publication No. 56-6453).

Further, in Japanese Unexamined Patent Publication (Kokai) No. 4-281920, a beam construction groove is partially excavated deep in the root cutting bottom, and a bottom plate is installed at the bottom of the excavation groove, or waste concrete is placed, A formwork on the side of the beam is built on it, a floor formwork is installed on the bottom cut bottom surface at the upper end level of the formwork, and concrete is placed in the floor formwork and beam formwork. A method of constructing beams and floors is described.

Further, regarding the construction method of the floor slab, Japanese Patent Publication No.
No. 21767 gazette, after discarding concrete is placed on the root cutting surface, a separating layer is applied thereon, and then reinforcement for floor slab and concrete is placed on the separating layer, After hardening, the construction method is described in which the lower part of the floor slab concrete is cut off while removing the waste concrete and the separation layer.

[0005]

SUMMARY OF THE INVENTION A conventional method for constructing a beam and a floor disclosed in Japanese Patent Publication No. 56-6453 discloses a mold which allows a beam and a floor frame to be firmly supported by many supporting works. Frame work and other work are required, which is very troublesome and troublesome, and accidents are likely to occur due to it. There is also a problem that the construction period is long due to the large number of working steps.

In this respect, the beam construction method described in Japanese Patent Application Laid-Open No. 4-281920 has the advantage that the supporting work is almost unnecessary. However, it is necessary to further excavate the groove for beam construction, install a bottom plate at the bottom of the excavation groove as a form of the beam bottom, or pour waste concrete. It is hard to say that construction work such as backfilling is still simplified.

Further, the method of constructing a concrete floor slab according to Japanese Examined Patent Publication No. 4-21767 is simplified by completely omitting the floor formwork and its supporting works, but only for constructing a floor (concrete floor slab). It is a related construction method and is applicable to a flat slab (beamless slab), but a method for constructing a beam or a slab with a beam is not specifically disclosed. Therefore,
The object of the present invention is to reduce and simplify the on-site work such as the construction work of the formwork and the installation work of the support work when constructing the beam and the floor in the reverse construction method as much as possible, and the labor cost is greatly reduced by manpower. It is to provide a method of constructing a beam and a floor that can reduce the number of works, shorten the construction period, and improve safety.

[0008]

As a means for solving the above-mentioned problems of the prior art, the method of constructing a beam and a floor in the upside-down construction method according to the present invention is as shown in FIG. In the upside-down construction method in which the root structure of the ground 3 and the construction of the skeleton are repeated in sequence toward the basement floor while constructing the main structure of the building, etc., it is slightly deeper than the lower surface of the beam 1 to be constructed. The root 3 of the ground is cut to the level L, and the discarded concrete (leveling concrete) 4 is placed from the root cutting surface L to the lower surface level of the beam 1, and the form material 5 for the beam is built on the side surface of the beam. In the lower surface of the floor 2, a support 6 for the floor is installed on the discarded concrete 4 to support the formwork material 7 for the floor, and the portion of the beam 1 and the floor 2 are supported.
The concrete 8 is cast in the portion of, and after the concrete 8 develops strength, the waste concrete 4 is removed together with the root cutting of the ground 3, and the floor support 6 is removed. .

In the construction method, after the waste concrete 4 is cast from the root cutting surface L to the lower surface level of the beam 1, the insulating material 9 is laid on at least the lower surface portion of the beam 1 of the discarded concrete 4 or the surface thereof. After processing, erection of beam form material 5 on the beam side, and floor support 6
It is also possible to construct without using. In addition, as shown in FIG. 2, the floor construction method of the second invention is such that the ground 3 reaches a level L ′ slightly deeper than the lower surface of the floor 2 to be constructed.
After cutting the roots of the soil and leveling the ground, laying the concrete 4 on the leveling surface, and placing the concrete 15 for the floor directly on it, after the floor concrete 15 develops strength It is characterized in that the waste concrete 4 is removed together with the root cutting of the ground 3.

[0010]

[Function] A level slightly deeper than the bottom surface of the beam (L in FIG.
Root cutting of the ground 3 is performed up to the level position shown by, and the discarded concrete 4 is placed from the root cutting surface L to the lower surface level of the beam 1, and the discarded concrete 4 effectively works as a formwork of the beam bottom. Moreover, since the formwork material 5 on the side surface of the beam is erected by standing (supporting) on the abandoned concrete 4, the construction of the beam 1 is completed quickly and safely without using any supporting work. be able to. Formwork material 5 for the beam
The beam 1 can be easily installed as it is by setting. By laying the insulating material 9 on the lower surface of the beam or performing a surface treatment, it is possible to surely cut the edge with the discarded concrete 4.

In the floor portion, supporting members 6 are installed on the waste concrete 4 as needed to support the formwork material 7, so that the formwork material 7 functions as the formwork of the floor 2 and the formwork material concerned. The floor 2 is easily constructed by driving 7 as it is. Even in the case of flat slabs without beams, the ground 3 is cut off to a position slightly deeper than the bottom surface of the floor (level position indicated by L'in Fig. 2), and the ground leveling is performed on the leveling surface. Since the discarded concrete 4 is laid on the floor, the discarded concrete 4 effectively functions as a formwork for the floor bottom, and the beamless slab can be constructed extremely simply.

[0012]

Embodiments of the present invention shown in the drawings will be described below. Figure 1 shows a reverse construction method for constructing a reinforced concrete or steel reinforced concrete structure underground structure by constructing a permanent structure consisting of a beam 1 and a floor 2 and repeating root cutting of the ground 3 and construction of the structure sequentially toward the basement. The example of is shown. In the figure, reference numeral 13 is a soil pillar row wall constructed for mountain retaining.

First, 50 mm from the lower surface of the beam 1 to be constructed
Root cutting of the ground 3 is performed to the position of the lower level L, which is about as deep as possible, and the ground level is sufficiently leveled to the lower level (root cutting surface).
A waste concrete (leveling concrete) 4 that forms a smooth horizontal surface from L to the lower surface level of the beam 1 is placed. That is, the upper surface level of the discarded concrete 4 is set to the same level as the lower surface level of the beam 1, and the discarded concrete 4 serves as a formwork for the beam bottom. Therefore, it is not necessary to construct a formwork on the bottom surface of the beam 1. .

Therefore, if necessary, an insulating material 9 such as a film sheet may be laid on the lower surface of the beam 1 on the surface of the waste concrete 4 or a surface treatment such as a peeling material (not shown) may be applied. Then, a form material 5 for temporary installation or driving of the side surface of the beam 1 to be constructed is built. Since the height of the formwork material 5 on the side surface of the beam is 550 mm, which is approximately the same as the height from the upper surface of the discarded concrete 4 to the lower surface of the floor 2, it is built upright on the discarded concrete 4, so that No support work is required to construct the beam 1. Moreover,
A cement board is used as the frame material 5 for the floor, and by driving it into the beam 1, the beam 1 can be easily constructed with the main installation. A large beam steel frame 10 is installed on the beam 1 and beam reinforcing bars 11 are arranged. The insulating material 9 is usually removed together when the discarded concrete 4 is finally removed, but may be left as long as it does not interfere.

Subsequently, when constructing the floor, a supporting work 6 (height of about 550 mm) is installed on the aforesaid concrete 4 just below the floor 2 to be constructed, and by this supporting work 6, the formwork material 7 for the floor is used. Support. As the floor form material 7,
For example, a permanent deck plate (steel material) that forms the lower surface of the floor 2, a PCa plate, a cement board (concrete material), or the like is used. It is also possible to use a temporary form material (such as a veneer wood material) instead of the main form material 7. As the supporting member 6 for the floor, a wooden material having a thickness substantially equal to the height from the insulating material 9 to the deck plate 7 and a foam material such as expanded polystyrene foam are preferably used. This is because the foam material is lightweight, convenient to handle, and sufficiently strong. Further, by temporarily fastening the supporting work 6 to the deck plate 7 with the fasteners 14, there is a possibility that the supporting work 6 may be broken and damaged during the removal of the waste concrete 4 and the root cutting work described later. Instead, it can be reused. However, when the distance between the beams is short, or when the beams can be directly supported, it is possible to carry out the construction without using the above-mentioned floor supporter 6. In addition,
Floor reinforcing bars 12 are arranged on the floor 2, and the ends of the floor reinforcing bars 12 are fixed to the girder steel frame 10 of the beam 1. After that, concrete 8 is placed on the beam 1 and the floor 2.

After the pouring concrete 8 hardens and develops a predetermined strength, root cutting of the ground 3 is restarted to remove the discarded concrete 4, and the beam form material 5 for temporary construction is dismantled and for the floor. The beam 1 and the floor 2 are completed by removing the support work 6.
Since there is no complicated and miscellaneous formwork work and installation work for supporting work unlike the conventional art, the work of removing the discarded concrete 4 (ground 3) can be performed easily and quickly. Moreover, since the work place is near the ground 3, there is no work at a high place, and construction can be performed safely.

In the following, the construction work of the beam and floor of the basement floor structure is carried out downward by the same procedure as described above, and the underground structure frame is constructed smoothly by the upside down construction method.

[0018]

[Second Embodiment] FIG. 2 shows an embodiment of a method for constructing a flat slab (beamless slab) also in the reverse construction method. From the bottom surface of the floor 2 to a depth of about 50 mm (level position shown by L'in FIG. 2), the root of the ground 3 is cut off to level the ground, and the concrete 4 is discarded on the leveled surface. To set. After the discarded concrete 4 develops strength to the extent that it can cut edges with the floor concrete 15 to be placed thereon, the floor reinforcing bars 12 are installed on the discarded concrete 4 and the floor concrete 15 is directly placed.
After the floor concrete 15 is hardened, the waste concrete 4 is removed together with the root cutting of the ground 3 to complete the flat slab 2.

Therefore, the abandoned concrete 4 works effectively as a formwork for the floor bottom, and a flat slab can be constructed extremely easily without using any supporting work, and the workability can be improved and the construction cost can be reduced.

[0020]

According to the method of constructing a beam and a floor in the upside-down construction method according to the present invention, the beam form material 5 and the floor form material 7 can be directly driven and used for main installation, Moreover, since the support 6 for the floor is used as necessary, normal formwork work and installation work of the support can be reduced as much as possible, the workability is improved, and the construction cost can be reduced by the significant labor saving. Contributes to shortening the construction period. Further, since the work place is close to the ground 3 and there is no work at a high place, it contributes to the improvement of safety.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing important steps.

FIG. 2 is a pivotal sectional view of a second embodiment.

[Explanation of symbols]

 1 Beam 2 Floor 3 Ground 4 Discarded concrete 5 Beam formwork 6 Supporting work 7 Floor formwork 8 Concrete 9 Insulation 15 Floor concrete

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Isao Yanagisawa 8-21-1, Ginza, Chuo-ku, Tokyo Stock company Takenaka Corporation Tokyo head office (72) Inventor Anjo Hanada 8--21, Ginza, Chuo-ku, Tokyo No. 1 Takenaka Corporation Tokyo Main Store (72) Inventor Pillar Tamaki 21-21 Ginza, Chuo-ku, Tokyo Stockholder Takenaka Corporation Tokyo Main Store (72) Inventor Toshi Kishishita Central Tokyo 8-21-1, Ginza, Ginza, Tokyo Takenaka Corporation Tokyo Main Store (72) Inventor Shigefumi Hayashi 8-21-1, Ginza, Chuo-ku, Tokyo Takenaka Corporation Tokyo Head Office (72) Inventor Kotake Ryuichi Tokyo Ginza 8-21-1, Chuo-ku, Tokyo Stock company Takenaka Corporation Tokyo Main Store (72) Inventor Tetsuo Kimura Ginza 8-chome, Chuo-ku, Tokyo Takenaka Corporation Tokyo Main Store ( 72) Inventor Yoshinori Kobikiyama, 21-21 Ginza 8-chome, Chuo-ku, Tokyo Stock company Takenaka Corporation Tokyo head office

Claims (4)

[Claims] 1. A beam to be constructed in a reverse construction method for constructing an underground structure of a building by repeating root cutting of the ground and construction of the structure sequentially toward the basement floor while constructing a main structure such as beams and floors. Root cutting of the ground to a level slightly deeper than the bottom surface of the ground, and pouring waste concrete from the root cutting surface to the bottom surface level of the beam. Place a supporting structure for the floor on the discarded concrete to support the formwork material, and place the concrete on the beam part and the floor part, after the concrete develops strength, along with root cutting of the ground A method for constructing a beam and a floor in a reverse construction method, characterized in that discarded concrete is removed and the floor support is removed. 2. After the waste concrete is cast from the root cutting surface to the lower surface level of the beam, at least the lower surface portion of the beam of the surface of the discarded concrete is laid with an insulating material or subjected to a surface treatment and then the side surface of the beam. The method for constructing a beam and a floor in the upside-down construction method according to claim 1, wherein a form material for the beam is built in. 3. The method for constructing a beam and a floor in the upside-down construction method according to claim 1 or 2, characterized in that the construction is carried out without using any supporting work for the floor. 4. A bottom surface of a floor to be constructed in a reverse construction method for constructing an underground structure of a building by sequentially repeating root cutting of the ground and construction of the structure toward the basement floor while constructing a permanent structure such as a floor. Performing ground leveling by cutting the ground to a level slightly deeper than that, laying waste concrete on the leveling surface, placing floor concrete directly on the waste concrete, and applying the floor concrete. The method for constructing a floor in the upside-down construction method, characterized in that the concrete is removed and then the discarded concrete is removed together with the ground cutting.