JP2001254366A - Method for constructing foundation by using left-in- place-steel form - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for constructing a foundation by using a steel form, which dispenses with a concrete curing period, and form dismantling work by embedding the steel form in the ground without removing the same, can drastically reduce a construction period, and cuts costs by virtue of reduction of surplus soil dealing cost of excavated soil and elimination of steel reinforced scaffold. SOLUTION: The ground is excavated according to the arrangement of the foundation consisting of a base portion and an underground beam portion, to thereby form a concave in which the base portion and the underground beam portion are housed. Then, a steel form 5 for the base and a steel form 6 for the underground beam which self-stand against earth pressure of backfilled earth are built in the excavated recess corresponding to the base portion and the underground beam portion, respectively, and the outsides of the steel form 5 for the base and the steel form 6 for the underground beam are backfilled with the excavated earth. Next, bars are arranged in the steel form 5 for the base and the steel form 6 for the underground beam, and thereafter concrete is placed in the steel form 5 for the base and the steel form 6 for the underground beam. In this manner, the foundation is constructed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buried steel formwork method for constructing a concrete foundation of a building.

[0002]

2. Description of the Related Art In a conventional method of constructing a concrete foundation of a building, a recess is excavated in the ground in accordance with the arrangement of the foundation, and veneer forms for foundation pillars and underground beams are buried in the recess. Assembled by using a separator, etc., erected by giving the formwork reinforcement by means of various stays provided between its outer surface and the recesses or the ground, laying concrete inside the assembled formwork, then casting concrete, concrete After the solidification of the mold, the formwork is dismantled to construct the base, and finally, the space between the base and the recess is filled back with soil.

[0003]

By the way, the conventional method as described above requires the time required for curing concrete,
In addition to the time required for dismantling the formwork, the construction period is long, and in the case of a narrow site, if the excavated soil generated by excavation of the recess cannot be stocked, not only must the excavated soil be taken out of the site and the remaining soil disposed, but also There is a problem that it becomes necessary to purchase and carry back the backfill soil, which increases the economic burden.

Further, the conventional veneer formwork is contrary to the trend of protecting timber resources and maintaining the global environment, and requires the installation of a reinforcing bar scaffold for maintaining accuracy when the column reinforcing bars are built. There is.

[0005] Therefore, an object of the present invention is to eliminate the need for concrete curing time and dismantling of the formwork by using a steel formwork to bury the formwork, thereby enabling a significant reduction in the construction period. Backfill steel at the base, which can protect wood resources, reduce the cost of disposal of excavated soil and the cost of purchasing backfill soil, and eliminate the need for reinforcing bars. An object of the present invention is to provide a molding method.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 has a structure in which a base portion and an underground beam are provided on the ground in accordance with the arrangement of a base portion including a base portion and an underground beam. Excavate the recesses that will fit in, and erected the steel formwork for the base in the excavation recess in the base and the steel formwork for the underground beam in the excavation recess in the underground beam, each standing independently against backfill earth pressure. Between the excavation recess and the steel formwork for the base and between the excavation recess of the underground beam and the steel formwork for the underground beam,
Reinforcement is arranged inside the steel formwork for the base and the steel formwork for the underground beam, and then concrete is poured into the steel formwork for the base and the steel formwork for the underground beam. It was done.

According to a second aspect of the present invention, in the first aspect of the present invention, the steel mold for the base is assembled into a frame shape using a keystone plate in a vertical direction, and a fixing member provided on the lower outer side of the keystone plate. And the belly fixed along the outer surface of the keystone plate are connected by a support member, the floor plate is placed on the fixed member, and the base plate is self-supported by the weight of the soil. This structure employs a configuration in which the end portion is fitted and fixed to an upstanding channel steel on a leg plate laid in a concave portion, so as to be self-standing.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

The base part constructed by the steel formwork method of the present invention comprises a base part A and an underground beam part B as shown in FIG. 1, and the base part A is placed on the ground in accordance with the arrangement of the base part. Excavation is carried out on the concave portion 1 in which the underground beam portion B is accommodated and the crushed stone 3 is laid on the bottom surface of the concave portion 1 and the underground beam portion B.
And the steel formwork for base 5 in the excavation recess 1 of the base portion A and the steel formwork 6 for underground beam in the excavation recess 2 of the underground beam portion B are erected independently.

As shown in FIG. 2, the base steel formwork 5 is assembled in a rectangular frame shape by arranging a keystone plate 7 having a predetermined height in four directions using a vertical direction. In the portion where the underground beam portion B of the plate 7 is continuous, the steel formwork 6 for the underground beam is formed from the upper end downward.
The connection notch 8 is provided. Incidentally, the keystone plate 7 can be set to a height of about 2.5 m, which is deeper than the conventional construction method, by reinforcement.

FIG. 4 shows a fixing structure of the keystone plate 7 on the discarded concrete 4. A supporting angle member 10 is provided on the outer surface of the peripheral angle member 9 disposed on the discarded concrete 4. The supporting angle member 10 is fixed by welding so as to protrude outward at predetermined intervals in the length direction, the support angle member 10 is discarded by the anchor 11 and fixed to the concrete 4, and the lower end portion of the keystone plate 7 is fixed to the peripheral angle member 9. The keystone plate 7 is arranged in an upright position, and the keystone plate 7 is fixed at an intermediate position along the outer surface with a bolt 12 along the outer surface, and a supporting angle member 10.
Are joined by a support member 14 using a reinforcing bar, and the keystone plate 7 is made to stand by itself.

A steel weight plate 15 is placed on the adjacent support angle member 10 so as to bury the steel weight plate 15, and an angle member 16 is mounted on the upper end of the keystone plate 7. The upper end corners of the adjacent keystone plates 7 are fixed to each other by a fired material 17 using the angle material 16.

FIG. 7 shows a connection structure of corner portions of the keystone plate 7 adjacent to each other.
8 and keystone plate 7 using bolts and nuts 19
Are joined at right angles. Such a base steel formwork 5
With the assembling structure, each keystone plate 7 is self-supported from the inside without reinforcement under the earth pressure of the backfill soil.

A column formwork 20 is arranged inside the base steel formwork 5. This column form 20 is also formed into a rectangular frame shape using a keystone plate, and the legs 21 at the four corners are placed on the discarded concrete 4, and the upper end thereof is at the same height as the base steel form 5, At a portion where the underground beam portion B is continuous, a cutout portion 22 for connecting the steel formwork 6 for the underground beam and the column and the steel formwork between the beams from the upper end downward is provided. I have.

The steel formwork 6 for underground beams is formed by arranging keystone plates 7a in a lateral direction and facing each other on both sides as shown in FIG. 3, and FIG. 5 and FIG.
The structure for fixing the keystone plate 7a on the crushed stone 3 is shown. A base member 23 using a C-shaped steel is installed on the crushed stone 3, and an H-shaped steel 24 or a C-shaped steel serving as a joint is back-to-back on the base member 23. The H-shaped steel 24 is fastened to the lower end of the H-shaped steel 24 using a bolt 25 and a nut 26 and an angle member 25 welded on the base member 23.
The angle member 25 'welded to the outer upper part of the section steel 24 and the end of the base member 23 are joined by a support member 27 using a reinforcing bar to make the H section steel 24 self-supporting.
The end of the keystone plate 7a is fitted into the groove 4 and is fixed by interposing a packing 28 on the outer surface side.

Keystone plate 7a opposed to both sides
Is configured such that an angle member 29 fixed to the upper end is detachably connected by a head connection 30.

FIG. 8 shows a corner structure of the column form 20 and a joint structure of the column form 20 and a steel form 31 between the column and the beam, using an angle member 32, bolts and nuts 33. It is structured to be fastened.

Next, a method of constructing the foundation will be described.

As shown in FIG. 9 (A), first, a concave portion 1 in which the base portion A fits in the ground is excavated in accordance with the arrangement of the base portion, and crushed stone 3 is laid on the bottom surface of the concave portion 1 and placed thereon. A cast concrete 4 is cast, and then a base steel formwork 5 is erected in the concave portion 1 and the underground beam portion B is fitted so as to connect the adjacent concave portions 1 as shown in FIG. The recess 2 is excavated, and crushed stone 3 is laid on the bottom of the recess 2.

As shown in FIGS. 2 and 4, the steel frame 5 for the base is set in the excavation recess 1 of the base portion A by using the keystone plate 7 in the vertical direction to form a frame on the discarded concrete 4. The keystone plate 7 is disposed from outside, and the support angle member 10 and
The steel weight plate 15 is placed on the support angle member 10, and the upper end corners of the adjacent keystone plates 7 are connected to each other with a fired material 17 to assemble. A pillar formwork 20 is provided inside the formwork 5.
Place.

As shown in FIG. 9 (C), a steel formwork 6 for the underground beam is erected in the recess 2 in which the underground beam portion B is accommodated. As shown in FIGS. 5 and 6, the steel formwork 6 for underground beams is installed.
On the crushed stone 3, base members 23 using a C-shaped steel are sequentially installed at the connection positions of the keystone plates 7 a, and H-shaped steels 24 serving as joints are fixed on both sides of each base member 23 so as to stand upright. Support member 27 for joining an angle member 25 'welded to the upper outside and an end of the base member 23
The keystone plates 7a are arranged opposite to each other by fixing the laterally oriented ends of the keystone plates 7a in the grooves of the adjacent H-shaped steel 24 by fixing them.

The end of the steel frame 6 for the underground beam and the steel frame 5 for the base are connected to each other at the cutout portion provided in the steel frame 5 for the base. When the steel formwork 5 for steel and the steel formwork 6 for underground beams are completed, FIG.
As shown in (D), the outside of the base steel formwork 5 and the outside of the underground beam steel formwork 6 are backfilled. For the backfill soil, the excavated soil generated by excavation of the concave portions 1 and 2 is used, whereby the excavated soil can be effectively treated, and the amount of excavated soil generated by excavation can be significantly reduced. Become.

Further, since the base steel formwork 5 and the underground beam steel formwork 6 are supported from the outside, they can sufficiently withstand the earth pressure of the backfill soil. The means will be buried in the backfill soil.

As shown in FIG. 10 (E), when the backfilling is completed, the lower reinforcement 34 for the base and the reinforcement 35 for the column 20 are arranged in the steel form 5 for the base. Next, FIG.
As shown in FIG. 10 (F), the ground frame 36 is placed on the steel formwork 6 for the underground beam, and the underground beam reinforcement 37 is laid on the underground frame 36, as shown in FIG. 10 (G). When the underground beam reinforcement 37 is assembled, the underground frame 36 is removed, the underground beam reinforcement 37 is dropped into the steel formwork 6 for underground beam, and then the upper part of the opposing keystone plate 7a is joined by the head joint 30. . The underground beam bars 37 are fitted in the base steel formwork 5 at their ends, and are placed inside the column bars 35.

Thereafter, as shown in FIG. 10 (H), in the steel formwork 5 for the base, the reinforcement of the hoop 38 to the column reinforcement 35 and the reinforcement of the upper base 39 are performed, respectively. Formwork 2
0 and steel formwork 3 for underground beam between column and beam
1 and then concrete is cast in the steel formwork 5 for the base and the steel formwork 6 for the underground beam. The steel formwork 5 for the base and the steel formwork 6 for the underground beam Is buried and the solidification of concrete completes the foundation of the building.

As described above, the steel formwork 5 for the base and the steel formwork 6 for the underground beam are buried and the foundation is constructed by casting concrete, so that the work of dismantling the formwork is not required at all. This eliminates the need for a waiting period for concrete curing.

[0027]

As described above, according to the present invention, a steel formwork for base and a steel formwork for underground beam are erected in the excavated recess, and the space between the formwork and the recess is filled with excavated soil. By using the excavated soil for backfilling, even on a small site where excavated soil cannot be stocked, excavated soil only needs to be processed in an amount corresponding to the amount of concrete poured in, reducing the cost of disposal of unremoved residual soil, It is possible to cope with the shortage of landfill sites, eliminating the need to purchase and transport backfill soil.

Further, by burying the steel formwork for the base and the steel formwork for the underground beam, there is no need to wait for the formwork dismantling work and the curing of the concrete, and it is possible to greatly shorten the construction period. .

Further, the steel formwork for the base and the steel formwork for the underground beam can be self-supported without reinforcing the earth pressure of the backfill soil, the excavation depth can be set deeper than the existing construction method, and the underground depth can be set. Can build a deep foundation.

In addition, the steel formwork for the base and the steel formwork for the underground beam are erected, and the space between the formwork and the concave portion is backfilled with excavated soil. While this is possible, the use of steel forms will also help protect the global environment.

[Brief description of the drawings]

FIG. 1 is a plan view showing a steel formwork for a base and a steel formwork for an underground beam.

FIG. 2 is a perspective view of a steel formwork for a base.

FIG. 3 is a perspective view of a steel formwork for underground beams.

FIG. 4 is a longitudinal sectional view of a steel formwork for a base.

FIG. 5 is a longitudinal sectional view of a steel formwork for underground beams.

FIG. 6 is an enlarged cross-sectional view showing a connection portion of a steel formwork for underground beams.

FIG. 7 is an enlarged cross-sectional view showing a connection portion of a base steel formwork.

FIG. 8 is an enlarged cross-sectional view showing a connection portion of a column formwork.

FIGS. 9A to 9D are explanatory diagrams sequentially showing the first half of the process of constructing a foundation.

FIGS. 10 (E) to 10 (H) are explanatory diagrams sequentially showing the latter half of the process of constructing the basic part.

[Explanation of symbols]

 1 recess 2 recess 5 steel formwork for base 6 steel formwork for underground beam 7 keystone plate 7a keystone plate A base part B underground beam part

Claims (2)

[Claims] 1. A steel for a base, wherein a concave portion in which a base portion and an underground beam portion are accommodated is excavated on the ground according to an arrangement of a base portion including a base portion and an underground beam, and each of the recesses is self-supported against backfilling earth pressure. The steel mold for the underground beam is set in the excavation recess of the underground beam, and the steel mold for the underground beam is erected in the excavation recess of the underground beam. The space between the steel beams for the underground beams is backfilled with excavated soil, and then the reinforcing steel is placed inside the steel frames for the base and the steel beams for the underground beams. And a concrete casting method in which steel is cast inside a steel formwork for underground beams. 2. The base steel formwork is assembled into a frame shape using a keystone plate in a vertical direction, and a bellows fixed along an outer surface of a keystone plate and a fixing member provided on a lower outer side of the keystone plate. Are attached by a supporting member, and a floor plate is placed on a fixed member, and is self-supported by the weight of the soil.The steel formwork for the underground beam uses a keystone plate in the lateral direction, and stands on a leg plate laid in a concave portion. 2. The method according to claim 1, wherein the end portion is fitted into and fixed to the grooved steel to be made to be self-supporting.