JPH10140970A - Construction method for vertical shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pull out a steel pipe after the use thereof to reutilize it by a method wherein after removing earth and sand in a steel pipe forced into the ground, a liner plate is provided in the pipe and chemical liquid is injected into a gap between the outer surface of the plate and the inner surface of the pipe and the pipe is pulled out before the liquid solidifies. SOLUTION: A steel pipe 1 is forced into the ground and earth and sand in the pipe 1 is removed by means of an excavator or the like to form a cylindrical column-like space 3 in the pipe 1, following which a liner plate 5 is placed in the space 3 and concrete 7 is placed at the lower end of the interior of the plate 5. And chemical liquid 11 is injected into a gap between the outer surface of the plate 5 and the inner surface of the pipe 1. The liquid 11 has a water- sealing function and serves as a lubricant to allow the pipe 1 to be easily pulled out. And the pipe 1 is pulled out before the liquid 11 solidifies. Thereafter when the liquid 11 has sufficiently solidified and concrete 7 cured, a vertical shaft is completed. Thus the steel pipe can be reutilized.

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 a shaft used for propulsion work for burying water and sewage pipes, cables and the like.

[0002]

2. Description of the Related Art As a method of constructing a shaft, the following is already known.

(1) A method in which a steel pipe is simply pressed into the ground without injecting a chemical solution into the ground, soil and sand in the steel pipe are removed, and concrete is poured into a lower end of the steel pipe (hereinafter, referred to as a "conventional method"). ").

(2) With respect to the stagnant gravel layer, the soil is improved by injecting a chemical solution into the ground on which the shaft is to be constructed, and then a liner plate formed by forming a corrugated plate into a cylindrical shape is lowered downward while digging the ground. After assembling, a method of injecting a chemical solution into the gap between the inner surface of the digged ground hole and the outer surface of the liner plate and placing concrete at the lower end of the liner plate (hereinafter referred to as "conventional method")
That. ).

[0005]

However, each of the above-described methods for constructing a shaft has the following problems.

(1) Conventional method Steel pipes press-fitted into the ground are expensive, but are discarded without being collected, which is uneconomical. Further, since there is no chemical solution layer around the steel pipe, it is necessary to inject the chemical solution into the shaft of the shaft.

(2) Conventional method In the case of a ground with a lot of spring water, it is difficult to inject a chemical solution. That is, when a chemical is injected into the ground with a lot of spring water, the chemical may not be solidified and may flow away with the water. In addition, it is difficult to inject a chemical solution into a gap between the inner surface of the digged ground hole and the outer surface of the liner plate. In other words, there is a possibility that the chemical solution may be washed away due to the spring water from the inner surface of the hole of the ground that has been dug down, and the injection of the chemical solution may have to be repeated. Further, it is not easy to assemble the liner plate downward while digging the ground.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to provide a steel pipe by press-fitting a steel pipe into the ground, removing earth and sand from the steel pipe, and then disposing a liner plate in the steel pipe. A method of constructing a shaft, characterized in that concrete was poured at the lower end of the steel pipe and a chemical solution was injected into a gap between the outer surface of the liner plate and the inner surface of the steel pipe, and the steel pipe was pulled out before the chemical liquid solidified. To provide.

[0009]

Next, embodiments of the present invention will be described with reference to the accompanying drawings. According to the present invention, the shaft is constructed as follows.

(1) Press-in of a steel pipe A steel pipe 1 is press-fitted into a position where a vertical shaft is to be constructed. That is, FIG.
The steel pipe 1 is buried vertically in the ground as shown in FIG. The steel pipe 1 is, for example, a cylindrical body having a diameter of 2 meters, but is not limited to this, and may have any length.

(2) Removal of soil The soil in the steel pipe 1 pressed into the ground is excavated and removed by an appropriate excavator or the like. That is, a columnar space 3 is formed in the steel pipe 1 as an example. See FIG.

(3) Arrangement of liner plate A liner plate 5 is arranged in the space 3 in the steel pipe 1. See FIG. As an example, the liner plate 5 is formed by forming a corrugated plate into a cylindrical shape, and is connected in the vertical direction as necessary.

(4) Casting concrete Concrete 7 is cast at the lower end in the liner plate 5. See FIG. That is, concrete 7 is cast in the liner plate 5 below the space 3. The concrete 7 will be the bottom of the shaft.

(5) Injection of chemical solution Chemical solution 11 is injected into gap 9 between the outer surface of liner plate 5 and the inner surface of steel pipe 1. The chemical liquid 11 has a water stopping function and also functions as a sliding material for facilitating the drawing of a steel pipe described later. As the chemical 11, for example, a cement-based material such as mortar is used. Since the steel pipe to be described later needs to be drawn out before the chemical liquid 11 is hardened, the time until the chemical liquid 11 hardens can be adjusted by adjusting the composition of the chemical liquid 11 depending on the work. The chemical liquid 11 is solidified in about one day to one week, for example. In addition, the order of the concrete casting (4) and the injection of the chemical solution (5) may be changed. That is, after the chemical solution 11 is injected into the gap 9 between the outer surface of the liner plate 5 and the inner surface of the steel pipe 1, the concrete 7 may be poured into the lower end of the liner plate 5.

(6) Pulling out the steel pipe The steel pipe 1 is drawn out before the chemical liquid 11 hardens. The chemical 11 before hardening becomes a lubricant when the steel pipe 1 is pulled out. Incidentally, it is extremely difficult to pull out the steel pipe 1 after the chemical liquid 11 has hardened. The drawn steel pipe 1 is reused. After the steel pipe 1 is pulled out, when the chemical solution 11 is sufficiently hardened and the concrete 7 cast at the lower end in the liner plate 5 is sufficiently hardened, the shaft is completed. At this time, a layer of the cured chemical solution 11 is formed on the outer periphery of the liner plate 5. See FIG.

[0016]

The present invention exhibits the following excellent effects.

(A) The steel pipe used for constructing the shaft is extremely expensive, but according to the present invention, the steel pipe can be pulled out after use and reused. It is more economical than the above-mentioned conventional method which has been “disposable”. Incidentally, the liner plate is also "disposable" in the present invention, but the liner plate is much cheaper than the steel pipe.

(B) Since the steel pipe is pressed into the ground to excavate and remove earth and sand from the steel pipe, the liner plate is disposed in the steel pipe. Therefore, the liner plate can be disposed extremely easily and quickly. Can be.

(C) Since the chemical is injected into the gap between the outer surface of the liner plate and the inner surface of the steel pipe, unlike the above-mentioned conventional method, the chemical can easily and surely enter the gap, and furthermore, due to spring water. Not affected by spills.

(D) There is no need to improve the ground by injecting a chemical solution in advance into the ground where the shaft is to be constructed.

(E) Since a layer of the cured chemical is formed on the outer periphery of the liner plate, there is no need to inject the chemical over the wellhead.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a steel pipe is pressed into a position where a shaft is to be constructed, and soil and sand in the steel pipe have been removed.

FIG. 2 is a cross-sectional view showing a state where a liner plate is provided in a space in a steel pipe.

FIG. 3 is a cross-sectional view showing a state in which concrete is poured into a lower end in a liner plate and a chemical is injected into a gap between an outer surface of the liner plate and an inner surface of a steel pipe.

FIG. 4 is a cross-sectional view showing a completed shaft after a steel pipe is pulled out.

[Explanation of symbols]

 Reference Signs List 1 steel pipe 3 space 5 liner plate 7 concrete 9 gap 11 chemical

Claims (1)

[Claims] 1. A steel pipe is pressed into the ground to remove soil from the steel pipe, a liner plate is disposed in the steel pipe, concrete is cast at a lower end in the liner plate, and the outer surface of the liner plate and the steel pipe are connected to each other. A method for constructing a shaft, comprising injecting a chemical solution into a gap between the inner surface and a steel pipe before the chemical solution hardens.