JPH08326068A - Method for constructing hollow deep basis using air bag - Google Patents

Abstract

PURPOSE: To make it easy to dispose of excavated soil by inserting an air bag in a specified position of an excavated hole, placing concrete in a space between the inner circumferential face of the hole and the outer circumferential face of the air bag in a condition where air is supplied, pulling up the air bag and forming a hollow part. CONSTITUTION: A steel-made mold for positioning the lower part of an inner mold 8 using an air bag 7 is mounted on the bottom part of a previously excavated cylindrical hole, and concrete 6 of an lower base is placed on the lower part of the steel-made mold. Next, the inner mold 8 is inserted in a specified position, air is supplied to the air bag 7 through an air hose 10 and an air valve 11, and concrete 12 is placed between the outer circumferential face of the inner mold 8 and the inner circumferential face of the hole. After hardening of the concrete the air in the air bag is extracted therefrom, the air bag is pulled out from the hole, and a hollow part surrounded by the concrete is formed. Next, the inner mold 8 is inserted in the upper half of the hole, concrete 13 is placed, a hollow deep basis having the hollow part is formed in the hole, and the hollow part is buckfilled with the soil as excavated from the hole.

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 deep foundation foundation for supporting a power transmission tower or a bridge, and more specifically, a hollow portion capable of filling the hollow portion with excavated soil produced when the deep foundation foundation is constructed. Regarding the construction method of the deep foundation.

[0002]

2. Description of the Related Art Generally, deep foundations for supporting power transmission towers or bridges are generally constructed on the slopes of mountainous areas. FIG. 12 is an external view of a conventional deep foundation foundation 51. The conventional deep foundation foundation 51 is constructed in a solid type without a hollow portion. A hole is excavated to construct the deep foundation 51, and a large amount of excavated soil appears. Previously, the excavated soil was often treated on the slope of the construction site.However, because the excavated soil may flow down and destroy the surrounding natural environment due to flooding, etc. It is transported to a flat area where there are no worries for processing.

[0003]

The excavated soil obtained by excavating the hole for constructing the conventional deep foundation 51 has to be transported from a mountainous area to a flat area where there is no danger of natural environment destruction and treated. In addition, transportation and treatment costs are high, and it has become difficult to secure a dump site for residual soil. Therefore, in the present invention, by constructing a hollow deep foundation foundation having a hollow portion for filling the excavated soil that has come out during the construction of the deep foundation foundation,
To provide a construction method for hollow deep foundations using airbags that significantly reduces the cost of excavated soil and reduces the total construction cost by reducing the amount of concrete for the construction of hollow deep foundations. This is a problem to be solved.

[0004]

According to the present invention, a method for solving the above-mentioned problems is a step of driving a concrete into an excavated hole to construct a deep foundation, in which 1 is set at a predetermined position of the hole. Insert individual airbags, and while supplying air until the internal pressure of the airbag reaches a predetermined value, pour concrete into the space between the inner peripheral surface of the hole and the outer peripheral surface of the airbag. After curing with air, the air in the airbag is evacuated to lower the internal pressure so that the airbag is separated from the concrete, and the airbag is pulled up from the hole to form a hollow portion. After filling the excavated soil when excavating the hole in the section,
It is to form a deep foundation in a predetermined shape.

[0005] In another method, in the process of driving a concrete into an excavated hole to construct a deep foundation, an airbag arranging member in which a plurality of airbags are positioned in a predetermined shape is formed in the hole. After being inserted into a predetermined position, air is supplied until the internal pressure of each airbag reaches a predetermined value, and the air is supplied to the space between the outer peripheral surface of the airbag disposing member and the inner peripheral surface of the hole. After the air bag is poured and cured, the air of the airbag is evacuated to separate the outer peripheral surface of the airbag arranging member from the concrete, and the hollow is formed by pulling up the airbag arranging member, and After filling the hollow portion with excavated soil when the hole is excavated, a deep foundation is formed in a predetermined shape.

[0006]

[Function] The hollow portion formed by the method of the hollow deep foundation using the above-mentioned airbag is filled with the excavated soil when the hole is excavated, which facilitates the treatment of the excavated soil, and Since it is not necessary to drive in concrete, the amount of concrete used is smaller than that of the conventional solid foundation.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a sectional view of a hollow deep foundation 1 that supports a power transmission tower or a bridge. As shown in FIG. 1, a hollow portion 2 is formed in a hollow deep foundation foundation 1, and when constructing the hollow deep foundation foundation 1, it is possible to fill the hollow portion 2 with excavated soil S when excavating a hole in advance. You can do it.
The construction method for constructing this hollow deep foundation 1 is shown below.
-It demonstrates, referring FIG.

In order to construct the hollow deep foundation 1 as shown in FIG. 1 at a predetermined position, as shown in FIG. 2, a required bar arrangement R is formed along the inner peripheral surface of the pre-excavated cylindrical hole H. After the construction, the inner formwork 8 using the cylindrical airbag 7 described later.
A steel mold 3 for positioning the lower part of the lower part (see FIGS. 4 and 5) is attached to a position close to the bottom of the hole H, and an inner mold for supporting the middle part of the inner mold 8 The frame support rings 4A and 5A are attached to the reinforcing bar R.

Next, as shown in FIG. 3, the lower base concrete 6 is driven into the lower portion of the steel mold 3 to harden it.
The lower base concrete 6 is filled with the concrete 12 between the outer peripheral surface of the inner mold 8 using the airbag 7 and the inner peripheral surface of the hole H (see FIG. 5). This is to prevent the concrete 12 from wrapping around the bottom of the inner mold 8 to give buoyancy to the inner mold 8 and prevent it from floating.

Next, as shown in FIG. 4, an inner mold 8 using a cylindrical air bag 7 is opened from the opening of the hole H via a rope RP connected to an elevator (not shown). Then, the inner mold 8 is vertically inserted into the hole H so that the lower part of the inner mold 8 is positioned by the steel mold 3. In order to protect the outer peripheral surface of the airbag 7, synthetic rubber or vinyl is used.
Although the seat 9 made of a rubber is used, it is possible to use only the airbag 7 without using the seat 9. Of course, when the sheet 9 is used, since the concrete is less likely to come into direct contact with the outer peripheral surface of the airbag 7, the airbag 7 is protected and the life is extended.

After the inner formwork 8 is inserted at a predetermined position,
From the compressor (not shown) to the air hose 10 and the air valve 11 so that the internal pressure of the airbag 7 reaches a predetermined value.
Air is supplied to the airbag 7 via the.

Next, as shown in FIG. 5, the concrete 12 is poured between the outer peripheral surface of the inner mold 8 and the inner peripheral surface of the hole H to be solidified. Then, after the concrete 12 is solidified, the air in the airbag 7 is evacuated and the airbag 7 and the sheet are sealed.
Take out the hole 9 from the hole H. In this state, a hollow portion surrounded by the concrete 12 is formed in the lower half of the hole H.

Next, as shown in FIG. 6, in the upper half of the hole H, the inner formwork support rings 4B and 5B for supporting the middle part of the inner formwork 8 are attached to the bar arrangement R, and then the airbag 7 is attached.
Insert the sheet 9 into the upper half of the hole H. Then, air is supplied from the compressor (not shown) to the airbag 7 via the air hose 10 and the air valve 11 so that the internal pressure of the airbag 7 becomes a predetermined value.

Next, as shown in FIG. 7, in the upper half of the hole H, the concrete 13 is poured between the outer peripheral surface of the inner mold 8 and the inner peripheral surface of the hole H to be solidified. Then, after the concrete 13 is solidified, the air in the airbag 7 is evacuated, and the airbag 7 and the sheet 9 are taken out from the hole H. In this state, since the underground portion 1B of the hollow deep foundation foundation 1 having the hollow portion 2 in the hole H is formed, the excavated soil S when the hole H is excavated in the hollow portion 2 is formed as shown in FIG. After packing, throw in the discard concrete 14.

As described above, since the excavated soil when excavating the hole H can be backfilled in the hollow portion 2 of the hollow deep foundation 1, the excavated soil need not be carried to a distant treatment site as in the conventional case. , The cost of treating the residual soil can be significantly reduced.

As described above, the underground portion of the hollow deep foundation 1 is constructed by using one air bag 7 as shown in FIG. 9, and then is disposed on the discard concrete 14 as shown in FIG. The entire hollow deep foundation 1 is completed by forming the above ground portion 1A by concrete.

Next, a method of constructing a hollow deep foundation using a plurality of airbags will be described with respect to its essential parts. In this embodiment, as shown in FIG.
Is used as an inner mold 23 having a circular shape arranged along the inner diameter surface of the synthetic rubber sheet 22. In FIG. 10, an inner mold 23, in which a plurality of airbags 21 are arranged in a circular shape along the inner diameter surface of a synthetic rubber sheet 22, is inserted into the hole H described above, and FIG. 11 is a plan view showing that the concrete 24 is driven between the outer peripheral surface of the inner mold 23 and the inner peripheral surface of the hole H while the inner pressure is increased to a predetermined value. FIG. 10 and 11 correspond to the state of FIG. 5 showing the step of forming the hollow portion 2 by the inner frame 8 using the one airbag 7 described above.

As shown in FIGS. 10 and 11, the inner mold 23
The lower part is positioned on the steel mold 3 similar to that of the above-mentioned embodiment, and the plurality of airbags 21 are made of synthetic rubber.
The styrofoam EPS is packed in the center while being arranged in a circular shape along the belt 22. The foamed polystyrene EPS is packed so that the inner mold 23 is not deformed even if the concrete 24 is driven in while the air is supplied to each of the airbags 21 to have a predetermined inner pressure. It should be noted that this foamed polystyrene EPS has a certain shape secured by the pressing force of the upper connecting plate 26 and the lower connecting plate 27 connected by a plurality of connecting rods 25.

When the concrete 24 is driven between the outer peripheral surface of the inner mold 23 and the inner peripheral surface of the hole H, this concrete is pressed.
The inner pad 28 is fitted into the gaps between the airbags 21 so that the belt 24 does not penetrate into the gaps between the airbags 21 and the seals are attached to the respective airbags 21.
An outer pad 29 is fitted in a gap between the inner peripheral surface of the boot 22 and the inner peripheral surface. Further, the inner formwork support rings 30A and 30B are attached to the bar arrangement R in advance, as in the above-described embodiment.

After the concrete 24 is driven in and hardened as described above, the air in the airbag 21 is evacuated, and the inner pressure is lowered to pull up the inner formwork 23 from the hole H to the lower half of the hole H. The hollow portion 2 is formed. Since the hollow portion 2 having a predetermined shape is formed by forming the hollow portion 2 also in the upper half of the hole H as in the above-described embodiment, the excavated soil when the hole H is excavated is the hollow deep foundation 1 Can be backfilled in the hollow portion 2 of With the construction method described above, the amount of work in the hole H is extremely small,
It is possible to construct a deep foundation with a relatively small diameter that is difficult for workers to enter, and the burden on workers is reduced.

[0021]

As described above, according to the present invention, one or a plurality of airbags are provided at predetermined positions in the hole in the step of driving the concrete into the excavated hole to construct the deep foundation. Insert the inner mold using the, and supply air until the inner pressure of the airbag reaches a predetermined value, in the space between the inner peripheral surface of the hole and the outer peripheral surface of the inner mold, After pouring the mixture into the mold, the inner mold was separated from the concrete by removing the air from the airbag to lower the internal pressure, and the inner mold was pulled up from the hole to form a hollow portion. In addition, since the excavated soil when excavating a hole can be filled in the hollow portion, the excavated soil processing cost can be significantly reduced, and the amount of concrete for constructing this deep foundation foundation decreases, Lower overall construction cost There is an effect that it is possible to.

[Brief description of drawings]

1 is a cross-sectional view of a hollow deep foundation.

FIG. 2 is an explanatory view of a construction process of a hollow deep foundation.

FIG. 3 is an explanatory view of a construction process of a hollow deep foundation.

FIG. 4 is an explanatory view of a construction process of a hollow deep foundation.

FIG. 5 is a diagram illustrating a construction process of a hollow deep foundation.

FIG. 6 is an explanatory view of a construction process of a hollow deep foundation.

FIG. 7 is an explanatory view of a construction process of a hollow deep foundation.

FIG. 8 is an explanatory view of a construction process of a hollow deep foundation.

FIG. 9 is an explanatory view of a construction process of a hollow deep foundation.

FIG. 10 is a plan view showing a state of a hollow deep foundation foundation construction process using a plurality of airbags.

FIG. 11 is a cross-sectional view showing a state of a hollow deep foundation foundation construction process using a plurality of airbags.

FIG. 12 is an external view of a conventional deep foundation.

[Explanation of symbols]

 1 Hollow deep foundation 2 Hollow part 7,21 Airbag 8,23 Inner formwork H hole S Excavated soil

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Oda 2-24 Yokota, Atsuta-ku, Nagoya, Aichi Chubu Electric Power Co., Inc. Central Transmission and Substation Construction (72) Inventor Hidetoshi Shimojima, Minato-ku, Nagoya, Aichi Prefecture 3-7-1, Wakamachi Chudenko Co., Ltd. Towaka Branch Office (72) Inventor Takayasu Iida 1-3-2, Sennen 3-chome, Minato-ku, Nagoya, Aichi Prefecture (72) Inventor Yasue Good luck, Hitachi Cable, Ltd., Chubu Branch, 4-26-13 Meieki, Nakamura-ku, Nagoya

Claims (3)

[Claims] 1. A step of driving a concrete into an excavated hole to construct a deep foundation, in which 1 is placed at a predetermined position of the hole.
Insert individual airbags, and while supplying air until the internal pressure of the airbag reaches a predetermined value, pour concrete into the space between the inner peripheral surface of the hole and the outer peripheral surface of the airbag. After curing with, the air of the airbag is evacuated to lower the internal pressure so that the airbag is separated from the concrete, and the airbag is pulled up to form a hollow portion. A method for constructing a hollow foundation foundation using an air bag, characterized by forming the foundation foundation in a predetermined shape after filling the excavated soil when excavating the hole. 2. An air bag arranging member having a plurality of air bags positioned in a predetermined shape is inserted into a predetermined position of the hole in the step of driving a concrete into the excavated hole to construct a deep foundation. Then, while supplying air until the internal pressure of each airbag reaches a predetermined value, a concrete is poured into the space between the outer peripheral surface of the airbag disposing member and the inner peripheral surface of the hole to cure. After that, the air of the airbag is evacuated to separate the outer peripheral surface of the airbag arranging member from the concrete, and a hollow portion is formed by pulling up the airbag arranging member, and the hole is formed in the hollow portion. A method for constructing a hollow deep foundation using an airbag, which is characterized by forming a deep foundation in a predetermined shape after filling the excavated soil when excavating. 3. Before inserting the airbag or the airbag arranging member into the hole, a concrete is poured into the bottom portion of the hole, and a positioning member for locating the airbag or the airbag arranging member is provided at the bottom portion of the concrete. It installs on the surface, The construction method of the hollow deep foundation foundation using the airbag of Claim 1 or Claim 2 characterized by the above-mentioned.