JPS58138871A - Construction of cylindrical structure utilizing buoyancy - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention The present invention relates to a method for constructing a liquid storage tank or other cylindrical structure having a hollow cross section. Elevating and lowering formwork equipment, simplifying mechanical equipment, improving safety and workability,
This makes it possible to save labor and reduce construction costs.

Conventional sidewall construction methods such as slip form and jumping form are different, but even if the structure collapses, brackets, etc. are fixed to an appropriate part of the structure where the concrete has hardened, and the formwork is used as a support using a lifting device. This is a method of raising and lowering scaffolding. Therefore, complicated mechanical equipment for raising and lowering the formwork and brackets to support it are required, which may result in poor economic efficiency and workability depending on the structure of medium height or less or the scale of the construction work. It also requires a skilled operator to operate the lifting device.

In order to improve these shortcomings, the construction method of this invention eliminates the need for complicated lifting and lowering equipment, and instead floats floats in liquid such as water injected into the tank and uses their buoyancy to support the formwork and scaffolding and raise and lower the water level. The formwork, etc. can be raised and lowered by

That is, in the method of constructing a cylindrical structure using buoyancy according to the present invention, a liquid is injected and stored inside a cylindrical side wall that is watertightly constructed to a predetermined height, and a float floating on this stored liquid is used to lift the upper end of the side wall. Support the formwork equipment installed in the section,
The method is characterized in that the formwork device is raised and lowered by adjusting the water level of the liquid, concrete is poured and cured while the formwork device is moved, and the upper side walls are successively constructed.

The present invention will be described below based on illustrated embodiments (FIGS. 1 to 5).

The embodiment shown in FIGS. 1 to 4 is used for constructing a liquid storage tank having a PC or RC structure, and in FIG. 1, 1 is the liquid storage tank, 1a is its side wall, and 1b is the bottom plate. A liquid such as water 2 is injected into the liquid storage tank 1 under construction, and a float 3 is floated inside the side wall 1a. For example, a pontoon-shaped float 3 can be used to sufficiently support the formwork device described below on the water! It shall be possible to do so. The floats 3 may be connected in the circumferential direction, or may be configured such that a plurality of independent floats 3 support the formwork device.

The formwork device consists of a formwork 4 facing both sides of the side wall concrete to be poured and a work scaffolding, suspended and supported by an inverted-shaped earth set up on a float and a formwork hanger 7 at the tip.

FIGS. 2 to 4 show the construction procedure. First, the side wall 1a that has already been constructed is made to withstand the water pressure to be injected by introducing prestress or reinforcing it with reinforcing bars. These prestresses also serve as reinforcement against the pressure of the liquid that will be stored after completion (see Figure 2).

Next, the formwork 4 and work scaffolding 5 fixed to the side wall 1alC are released, and water 2 is poured into the tank.

As the water level rises, the float 3 rises, and its buoyancy pushes up the formwork 4 and scaffolding 5 (see Figure 3).

When it rises to a predetermined position, the injection of water 2 is stopped and the formwork 4 and scaffolding 5 are fixed to the side wall 1a. After the concrete 8 is poured and hardened, the necessary prestress is introduced (see Figure 4).

By repeating the above operations, the side walls 1a are successively constructed.

Note that after pouring the concrete 8, curing for about 4 to 5 days is usually required before prestressing is introduced, but if shortening the construction period is required, early-strengthening cement or the like is used.

The construction of a liquid storage tank has been described above, but the construction method of the present invention can also be applied to a structure that is water-tight and whose side walls are designed to withstand water pressure, that is, a bridge pier with a hollow cross section,
It can also be used to construct silos, chimneys, etc. In addition, if the side wall cannot withstand the water pressure due to construction of the high bridge pier 9, etc., a waterproof bottom plate 10 as shown in FIG. 5 may be provided in the middle, and water 2 may be poured into it.

As described above, according to the method of constructing a cylindrical structure using the buoyancy of the present invention, the formwork device is supported by a float floating in a stored liquid such as water, and the formwork is adjusted by adjusting the water level of the stored liquid. Since the device is raised and lowered, there is no need for complicated mechanical equipment, support fittings, etc. for raising and lowering, unlike in the past. Therefore, unless the scale of the construction work is particularly large, it is excellent in economy, workability, etc., and the work is extremely simple. Furthermore, since this construction method injects a liquid such as water into the cylindrical structure, watertightness can be checked at each construction step, eliminating the need for water filling tests after completion.

(4) Also, if there is a water leakage point, it can be dealt with immediately at each construction stage.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing an overview of the construction method of this invention, Figures 2 to 4 are vertical cross-sectional views showing the construction procedure, and Figure 5 is a vertical cross-sectional view when used for constructing a high bridge pier. be. l...Liquid storage tank, 1a...side wall, 1b...bottom plate, 2
...Water, 3...Float, 4...Formwork, 5...
Work scaffolding, 6... Arm, 7... Formwork hanging tool, 8...
・Concrete, 9...High pier, 10...Waterproof bottom plate.

Claims (1)

[Claims] (1) A liquid is injected and stored inside a cylindrical side wall constructed watertight to a predetermined height, and a formwork device installed at the upper end of the side wall is supported by a float floating on this stored liquid, and the water level of the liquid is This is a cylindrical structure that utilizes buoyancy, which is characterized by raising and lowering the formwork device by adjusting the buoyancy, placing and curing concrete while moving the formwork, and sequentially constructing the upper side wall. How to build structures.