JPH09279598A - Execution work method of open caisson - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance workability by connecting a water jet injection pipe at a right angle to a high pressure water supply pipe to the tip of the high pressure water supply pipe suspended in an open caisson, and injecting pressure water toward a cutting edge inside surface of the open caisson. SOLUTION: A sticking clay removing device A is composed of a high pressure water supply pipe 3 fixed to a suspending material 2, a water jet injection pipe 5 and a swing preventive ring 6. Next, in case of execution work, a high pressure pump is driven by confirming that the injection pipe 5 reaches the edge of a caisson, and high pressure water is injected into sticking clay B from the injection pipe 5 through a high pressure jet hose 7. Next, a handle on the upper end of the suspending material 2 is horizontally rotated from above a work scaffold 9, and high pressure water is blown left and right toward the clay B, and a signal is given to a crane operation, and the suspending material 2 is vertically moved. This operation is performed once over the whole circumference of the cutting edge, and this is repeated several times, and the clay B is worn off from the cutting edge. Therefore, execution work can be efficiently, safely and reliably performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for excavating an open caisson, and more particularly to a method for constructing an open caisson that efficiently removes adhered clay adhering to the inner surface of a blade of an open caisson.

[0002]

2. Description of the Related Art In excavation and subsidence work of an open caisson, the cutting edge of the open caisson reaches a support layer (gravel layer), and the silty clay layer on the support layer adheres to the inner surface of the blade and sinks. There may be a case where it becomes impossible. In such a case, conventionally, a stick formed by processing an H-shaped rope is hung by a crane and the adhered clay is dropped to drop the clay, or a diving worker performs underwater work to remove the adhered clay.

[0003]

However, the above-mentioned conventional methods have the following problems. <B> Since the clay is dropped by poking the adhered clay part with a dash, only local removal is possible. <B> Since work is performed in a state where the work location cannot be seen, work efficiency is poor, such as duplication of the location that was once picked. <C> In the case of underwater work by a diver, the risk of work increases.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to remove adhered clay in the vicinity of an open caisson blade with high work efficiency, reliability, and low cost. To provide an open caisson construction method that enables safe work.

[0005]

In order to achieve the above-mentioned object, the present invention hangs a high-pressure water pipe in the internal space of an open caisson, and the high-pressure water pipe has a right angle with the tip of the high-pressure water pipe. A water jet injection pipe is connected to the water jet injection pipe to inject pressurized water from the water jet injection pipe toward the inner surface of the open caisson blade mouth.

Further, in such a construction method, the following modes can be preferably adopted. 1. A high-pressure water pipe is hung along the side wall of the open cason. 2. Fix the steady rest ring in the middle of the high pressure water pipe. 3. A plurality of water jet injection pipes are provided in the horizontal direction.

[0007]

Embodiment 1 Embodiments of the present invention will be described below with reference to the drawings. <B> Overall Configuration FIG. 1 is a vertical cross-sectional view of a general method for constructing an open caisson according to the present invention. At the center of the open caisson body 1 (hereinafter simply referred to as the caisson body 1), a rigid suspending member 2 such as a tremie pipe is suspended, and along this suspending member 2, a high-pressure water pipe 3 is integrated with a pipe band or the like. It is fixed. A water jet injection pipe 5 is connected and fixed to the tip of the high-pressure water supply pipe 3 at a right angle to the high-pressure water supply pipe 3.
Near the lower end of the drooping member 2 (slightly above the water jet injection pipe 5), a steady rest ring 6 is fixed around the drooping member 2. The upper end of the high-pressure water pipe 3 integrally fixed to the hanging member 2 is connected to the high-pressure jet hose 7, and is configured to receive water supply from a high-pressure pump (not shown) in the water storage tank 8. There is. <B> Detailed description of configuration The hanging member 2, the high-pressure water supply pipe 3, the water jet injection pipe 5, and the steady ring 6 are integrally fixed in advance on the ground, but when the caisson body 1 is deep, the hanging member 2,
The high-pressure water supply pipe 3 is divided into appropriate lengths, and on the working scaffolding 9 provided at the upper end of the caisson frame 1, the high-pressure water supply pipes 3 are successively replenished to the required length. As shown in FIG. 2, the steady size of the steady rest ring 6 is made slightly smaller than the distance between the inner surfaces of the side walls of the caisson body 1, and is fixed to the hanging member 2 by welding or the like. As shown in FIG. 3, the water jet injection pipe 5 is connected to the lower end of the high-pressure water supply pipe 3 fixed to the hanging member 2 so as to form a right angle, and is fixed to the lower end of the hanging member 2.

[0008]

[Action]

<B> Set of adhering clay removing device On the ground, the hanging down of the adhering clay removing device A, which is composed of the hanging material 2 and the high-pressure water supply pipe 3 integrally fixed in advance, the water jet injection pipe 5, and the steady ring 6 The upper end of the material 2 is lifted by a crane car or the like, and is lowered into the internal space of the caisson frame 1 by a signal of a worker on the work scaffold 9. When the water jet injection pipe 5 at the lower end of the hanging member 2 reaches the caisson blade edge, the lowering of the hanging member 2 is stopped by the operator's signal. This completes the setting of the adhered clay removing device A. Next, the high pressure jet hose 7 for supplying the water in the water storage tank 8 and the high pressure water supply pipe 3 are connected, and the preparation for the adhered clay removal work is completed. <B> Removal of adhered clay After confirming that the water jet injection pipe 5 has reached the caisson blade tip, a high pressure pump (not shown) in the water storage tank.
Operate. The high-pressure water is sent through the path of the high-pressure jet hose 7, the high-pressure water supply pipe 3, and the water jet injection pipe 5,
Clay B adhered from the nozzle at the tip of the water jet injection pipe 5
Injected toward. At the same time as the high-pressure water injection, the worker on the work scaffolding 9 at the upper end of the caisson body 1 horizontally rotates the handle attached to the upper end of the hanging member 2 to move the high-pressure water left and right toward the adhering clay B on the inner surface of the blade. And the crane operator is signaled to move the hanging member 2 up and down. Thereby, the high-pressure water sprayed toward the adhered clay B can be changed in the vertical direction. The adhered clay B sprayed with high-pressure water vertically and horizontally is sequentially peeled off from the inner surface of the blade edge. This operation is repeated all around the inner surface of the blade opening. Then, the hanging member 2 is pulled up a little more than the above-mentioned vertical width, and the same operation as the previous time is repeated. By repeating the above operation 3 to 4 times in sequence, the adhered clay B adhering to the inner surface of the blade can be completely removed from the inner surface of the blade.

[0009]

Embodiment 2 of the Invention FIGS. 4 to 6 show another embodiment in which a water jet injection pipe 5 is moved along a side wall of a caisson body 1. Clay adhering to the inner surface of the blade mouth while moving the nozzle of the water jet injection pipe 5 fixed to the lower end of the hanging member 2 toward the adhering clay B on the inner surface of the blade mouth while sequentially moving along the side wall of the caisson body 1. To remove. In this case, the steady ring is a steady ring 6 as shown in FIG. 5 when the caisson frame 1 has a circular cross section.
1, or if the caisson frame 1 has a square cross section,
A steady rest ring 62 as shown in FIG. 6 is appropriately attached. In the present embodiment, the jet distance of the water jet is not affected by the diameter of the caisson body 1,
It is suitable when the caisson body 1 has a large diameter.

[0010]

Third Embodiment FIG. 7 shows another embodiment in which the water jet injection pipe 5 is horizontally attached not only in one direction but also in a plurality of directions. FIG. 8 shows a partially enlarged view thereof. In this case, the water jet injection pipe 5 is
Since high-pressure water is jetted in a plurality of horizontal directions, the pressures at the time of jetting cancel each other out.
The steady rest ring 6 for receiving the reaction force as shown in FIG. Further, according to the present embodiment, the work efficiency for removing the adhered clay B on the inner surface of the blade is further increased, and the work period for caisson settlement can be shortened.

[0011]

Since the present invention has been described above,
The following effects can be obtained. <B> The high-pressure water jetted from the water jet jet pipe 5 jets the high-pressure water from a short distance from the clay adhering to the inner surface of the blade, so that the clay can be reliably and efficiently ejected from the inner surface of the blade. Can be stripped off. <B> Since the steady rest ring 6 is fixed near the lower end of the hanging member 2, it serves as a reaction force receiving the high-pressure water jetted from the water jet jet pipe 5, and adheres to the water jet jet pipe 5. The distance from the clay B is always constant, and the pressure of the high pressure water does not weaken. <C> By providing a plurality of water jet injection tubes 5 in the horizontal direction, the clay B adhering to the inner surface of the blade at a plurality of locations can be simultaneously peeled off by a single operation. <D> Since the operation is always performed according to the instructions of the worker on the scaffold, accurate work can be performed efficiently and safely.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a caisson showing a general work situation according to the present invention.

FIG. 2 is a plan view of a steady rest ring.

FIG. 3 is a partially enlarged view of a mounting portion of a water jet injection pipe.

FIG. 4 is a vertical cross-sectional view showing a work situation along the side wall of the open caisson.

FIG. 5 is a plan view of a steady rest ring when the open caisson has a circular cross section.

FIG. 6 is a plan view of a steady ring when the open caisson has a square cross section.

FIG. 7 is a vertical cross-sectional view of a lower end portion of an open caisson in which water jet injection pipes are arranged in multiple directions.

FIG. 8 is a partially enlarged view of FIG.

Claims (4)

[Claims] 1. A method of constructing an open caisson,
A high-pressure water pipe is suspended in the internal space of the open caisson, and a water jet injection pipe is connected to the tip of the high-pressure water pipe at a right angle to the high-pressure water pipe. An open caisson construction method characterized by spraying pressurized water. 2. The method for constructing an open caisson according to claim 1, wherein a high-pressure water pipe is suspended along a side wall of the open caisson, and the high-pressure water pipe is sequentially moved along the side wall. 3. The method for constructing an open caisson according to claim 1, wherein a steady rest ring is fixed to an intermediate portion of the high pressure water pipe. 4. The method for constructing an open caisson according to claim 1, wherein a plurality of water jet injection pipes are provided in the horizontal direction.