JPH0893218A - Construction method of independent foundation and folding formwork for independent foundation - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a method of constructing an economical independent foundation with good workability, and a formwork for an independent foundation that is easy to assemble on site and is inexpensive to manufacture. [Structure] The folding frame comprises four steel plate panels 1 and tie bars 4 whose edges adjacent to each other are connected by a connecting sheet 5 as a joining member. A hole 9 for a hole-in anchor or a concrete nail 7 for fixing to abandoned concrete is opened in the lower bent portion 2 of the steel plate panel 1. The upper bent portion 3 has a hole 10 for joining the tie bar 4. At the time of transportation and storage, the steel sheet panels 1 are folded at the connecting sheet 5 portion. The folding formwork is spread out in a rectangular shape on the outside of the reinforcing bars arranged on the discarded concrete at the independent foundation construction position, and the concrete is placed inside.

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 independent foundation and a folding formwork for an independent foundation, which is used for constructing a footing portion of a concrete independent foundation.

[0002]

2. Description of the Related Art Generally, when constructing a footing part of a concrete independent foundation, after excavating and compacting the soil, four plywood or metal weir panels are erected on the discarded concrete and arranged in a rectangular shape. Then, it is fixed with a separator or the like. After placing and solidifying concrete, dismantle the formwork,
It has been removed and the excavation area is backfilled.

Further, recently, in order to save the labor of disassembling the formwork, a discarding formwork method such as a lath formwork method in which a steel frame is used as a weir plate for the lath wire net is becoming popular.

Further, Japanese Patent Application Laid-Open No. 4-203024 discloses a circular frame made of a strip-shaped plate material. This is a thin band-shaped plate material that is rolled into a cylindrical shape on site, and the overlapping portion is fastened with screws, providing a simple and inexpensive disposal formwork.

[0005]

In the conventional formwork construction method,
Since the plywood and metal dams are reused, disassembling these formwork materials is very troublesome, and cleaning and maintenance for reuse are also expensive.

[0006] In order to solve these problems, various waste formworks such as the lath formwork method have been proposed, but all of them require labor for on-site assembly and are complicated and have a complicated structure. Production costs are also high. Further, since the form ties and the corner corners are used for assembling the formwork as in the conventional method, it is necessary to collect these materials.

On the other hand, the circular formwork described above is an economical discarding formwork which utilizes the hoop tension effect of the plate itself, but has various problems because the shape of the footing is limited to a circular shape.

That is, in the case of the direct foundation, the circular foundation is inefficient as compared with the rectangular foundation, so that the foundation shape becomes large and it is uneconomical. Even in the case of pile foundations, especially in the case of two piles, the shape is wasteful. Furthermore, when assembling this formwork on site, it is necessary to fasten the place where the plates are overlapped with a screw, which causes some trouble.

An object of the present invention is to provide a method for constructing an economical independent foundation with good workability, and a formwork for an independent foundation that is easy to assemble on site and is inexpensive to manufacture.

[0010]

A method for constructing an independent foundation according to the present invention is one in which four steel plate panels each having an upper bent portion and a lower bent portion on two upper and lower sides are erected so as to have a rectangular planar shape. The outer side of the reinforcing bar that is placed on the discarded concrete at the construction position of the independent foundation by arranging and joining the adjacent edges of the steel plate panels through the bendable joint member to make the foldable folding formwork for the independent foundation. It is installed by spreading it in a rectangular shape and placing concrete inside the folding formwork to build footing of an independent foundation.

Although the folding formwork is usually installed after the reinforcement for the independent foundation is performed, the reinforcement work for the independent foundation may be performed after the installation of the folding formwork in some cases.

Regarding the lower bent portion of the steel plate panel,
With the folding formwork placed on the discarded concrete, it can be fixed to the discarded concrete with the lower bent portion, concrete nails or hole-in anchors.

If necessary, the upper bent portions of the steel plate panels facing each other are connected to each other by a connecting member such as a tie bar so that the rectangular shape is maintained and resists the pouring pressure of concrete.

A folding formwork for an independent foundation of the present invention is a formwork for use in the above-described construction method, and has four steel plate panels each having an upper bent portion and a lower bent portion on two upper and lower sides and having a planar shape. Place it so that it becomes a rectangle,
Adjacent edges of the steel sheet panels are joined via a bendable joining member so that they can be folded.

As the joining member, for example, a flexible synthetic resin sheet or a metal hinge can be used.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The illustrated embodiment will be described below.

1 (a) and 1 (b) show an embodiment of the folding formwork of the present invention, in which four adjacent steel plates are joined by connecting sheets 5 as joining members. It consists of a panel 1 and a tie bar 4.

The upper and lower edges of the steel plate panel 1 are bent,
Holes 9 for hole-in anchors or concrete nails 7 for fixing to waste concrete are provided in the lower bent portion 2.
Is open. Also, a tie bar 4 is provided on the upper bent portion 3.
A hole 10 for joining the two is open.

At the time of transportation and storage, since the steel sheet panels 1 can be folded at the connecting sheet 5 portion into a shape as shown in FIG. 1 (b), no extra space is required.

The connecting sheet 5 is a synthetic resin sheet having a high tensile strength and a good bending followability (for example, a sheet used for a conveyor belt can be used) and a mounting hole is opened.

As shown in FIG. 2, this is joined to the hole formed in the edge of the steel plate panel 1 with bolts 6 or the like,
Panels can be connected in a foldable manner. Further, by installing the steel plate panels 1 over the full height of the connecting side, it is possible to prevent leakage of concrete.

Further, the connecting sheet 5 may be attached by a strong adhesive instead of bolt connection. Further, instead of the connecting sheet 5, other bendable joining members such as hinges may be used.

The steel plate panel 1 is made of a steel plate having a plate thickness as thin as possible in order to reduce the weight as much as possible and to be carried by human power for economic reasons. The upper and lower edges are bent for the following reasons. ing.

The lateral pressure of concrete applied to the steel plate panel 1 is first transmitted to the upper and lower bent portions 2 and 3 of the steel plate panel 1 as a uniformly distributed load. The lower bent portion 2 resists the load as a continuous beam whose both ends are supported by the connecting sheets 5 and whose middle portion is supported by the concrete 11 with the hole-in anchor or the concrete nail 7. On the other hand, the upper bent portion 3 resists as a simple beam whose both ends are supported by the connecting sheet 5 which is a panel connecting portion.

In general, the lateral pressure of concrete is proportional to the depth of concrete, so the lower and upper bent portions 2, 3
The load distributed to each of the parts is 2 to 1, and it is not necessary to support the intermediate part of the upper bent part 3 like the lower bent part 2.

However, if the shape of the foundation is large, it is necessary to connect the upper bent portions 3 of the steel plate panels 1 facing each other with the tie bars 4. The tie bar 4 is a steel strip having holes formed at both ends, and is joined to the upper bent portion 3 by bolts 8 as shown in FIG. 3 (a).

The bent shape of the upper and lower sides is as shown in FIG.
The single bend shown in (a) is simple, but in order to increase the strength, the lip groove cross section as shown in Fig. 3 (b), or as shown in Fig. 3 (c), it is folded back and folded up and down. Two
The shape of 3 may be increased. Furthermore, in order to suppress the protrusion of the central portion of the mold frame to a small extent, corrugated plate processing may be performed in the height direction.

FIG. 4 shows an embodiment of the independent foundation constructed by the construction method of the present invention. The footing portion of the independent foundation is constructed by the following procedure.

The position where the formwork is to be installed is marked out on the discarded concrete 11.

The base reinforcing bars 12 and the columnar reinforcing bars 13 are arranged.

The formwork of the present invention, which has been carried in a folded state from the manufacturing factory, is spread out in a rectangular shape and placed on the discarded concrete 11.

The lower bent portion 2 of the formwork is discarded with a hole-in anchor or concrete nail 7 to provide concrete 1
Fixed to 1.

If it is necessary for further strength, FIG. 1 (a)
As shown in, the upper bent portions 3 of the opposite molds are connected to each other by the tie bars 4 and the bolts 8. (Base rebar 12
The bar-shaped rebar 13 can be arranged even after the formwork is installed, depending on the situation of the site. However, in that case, the upper tie bar 4 is attached after the reinforcement. ) Pour the concrete 14 into the formwork.

After the concrete 14 has hardened to a certain extent, the foundation is completed by backfilling the footing with the formwork as it is.

[0035]

According to the method of constructing an independent foundation of the present invention, the work at the site is as simple as expanding a folded object into a rectangle and fixing it with nails or bolts. Since it does not require dismantling, it is possible to significantly shorten the foundation construction process.

Further, the folding formwork of the present invention is convenient to carry in the folded state and is rectangular in the unfolded state, so that it is efficient as a formwork of an independent foundation and is more efficient than the conventional discarding formwork. It is economical.

[Brief description of drawings]

1A and 1B show an embodiment of a folding formwork of the present invention, in which FIG. 1A is a perspective view in an unfolded state, and FIG. 1B is a perspective view in a folded state.

FIG. 2 is a horizontal sectional view of a connecting portion of a steel plate panel.

3A is an enlarged cross-sectional view of a main part of the mold of FIG. 1, and FIGS. 3B and 3C are cross-sectional views showing a modified example of a bent portion of a steel plate panel.

FIG. 4 is a cross-sectional view of the independent foundation on which concrete has been poured, immediately before backfilling, in the construction method of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Steel plate panel, 2 ... Lower bending part, 3 ... Upper bending part, 4 ... Tie bar, 5 ... Connection sheet, 6 ... Panel connection bolt, 7 ... Hole-in anchor or concrete nail, 8 ... Bolt, 9 ... Hole-in anchor Or holes for concrete nails, 10 ... holes for tie bars, 11 ... discarded concrete, 12 ... base rebar, 13 ... pillar rebar, 14
…concrete

Claims (4)

[Claims] 1. Steel sheet panels having upper and lower bent portions on two upper and lower sides are arranged upright so that a planar shape is rectangular, and adjacent edges of the steel sheet panels can be bent. The folding formwork for the independent foundation that is foldable and joined through a flexible joining member is installed by spreading it in a rectangle outside the reinforcing bars that are laid on the discarded concrete at the construction position of the independent foundation. A method of constructing an independent foundation characterized by placing concrete inside. 2. The independent according to claim 1, wherein when the folding formwork is installed on abandoned concrete, a lower bent portion of a steel plate panel constituting the folding formwork is fixed to the abandoned concrete with concrete nails or hole-in anchors. How to build the foundation. 3. The method for constructing an independent foundation according to claim 1, wherein the upper bent portions of the steel plate panels facing each other constituting the folding formwork are connected by tie bars. 4. The four steel plate panels having upper and lower bent portions on two upper and lower sides are arranged upright so as to have a rectangular planar shape, and adjacent edges of the steel plate panels can be bent. Folding form for independent foundation that can be folded by joining through various joining members.