JPH0921137A - Device for relieving disturbance in surrounding natural ground in pneumatic caisson - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relieve disturbances in surrounding ground arising from side earth pressure oh occasion of sinking a caisson body, and to make stabilized sinking possible for the caisson body. SOLUTION: A plurality of air intakes 4 are provided at specified intervals at the periphery of a caisson body 1, and air chambers 5 are provided at the inside of a row of the air intakes. Air passages 7 for releasing air to the outside air above the ground through the inside of the side wall of the caisson body 1 are connected to the air chambers 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disturbance mitigation device for surrounding rocks in order to reduce disturbance of the surrounding rocks when a caisson structure is submerged in the ground by a pneumatic caisson method to construct a shaft.

[0002]

2. Description of the Related Art When a caisson skeleton is submerged in the ground by a pneumatic caisson method to construct a shaft, earth pressure around the caisson skeleton acts like a wedge, and the surrounding ground may be disturbed.

When oxygen-deficient air is present around the caisson skeleton, the air blown into the working chamber of the caisson skeleton pushes out the oxygen-deficient air.

However, the prior art does not take special measures against these phenomena.

[0005]

Therefore, in the prior art, when the caisson skeleton is subsided, the earth pressure around the caisson skeleton acts like a wedge, the surrounding ground is disturbed, and the caisson skeleton is sunk in an unstable state. there were.

When oxygen-deficient air is present in the surroundings, the air blown into the work chamber below the caisson frame pushes out the oxygen-deficient air, which leaks the oxygen-deficient air to nearby wells, ponds, etc. There were also problems that had an adverse effect.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the disturbance of the surrounding ground due to the earth pressure at the side of the caisson skeleton when the caisson skeleton is subsided and to stabilize the caisson skeleton. The purpose of the present invention is to provide a turbulence mitigation device for surrounding natural ground in a pneumatic caisson that can be subsided at.

Another object of the present invention is to provide a turbulence alleviating device for surrounding natural ground in a pneumatic caisson which can prevent clogging of an air chamber and an air passage due to surrounding earth and sand.

[0009]

In order to achieve the above object, the present invention provides a plurality of air intake ports 4 at a predetermined interval on the outer periphery of a caisson frame 1 and an air intake port inside the row of air intake ports. A chamber 5 is provided, and this air chamber 5
An air passage 7 is connected to the inside of the caisson body 1 to release air to the atmosphere on the ground.

In order to achieve the above object, according to the present invention, a steel blade fitting 3 is fixed to a blade opening 2 of the caisson body 1, and the air intake 4 and an air chamber are fixed to the blade fitting 3. And 5 are provided.

Further, in order to achieve the above object, the present invention provides a filter 6 in the air chamber 5.

[0012]

In the present invention, a plurality of air intake ports 4 are provided at a predetermined interval on the outer periphery of the caisson frame 1, and an air chamber 5 is provided inside the row of air intake ports. An air passage 7 is connected to the air chamber 5 through the inside of the side wall of the caisson body 1 to release air to the atmosphere on the ground. As a result, the air around the caisson frame 1 enters the air chamber 5 through the air intake 4, and is released from the air chamber 5 through the air passage 7 to the atmosphere on the ground. As a result, when the caisson body 1 is subsided, it is possible to mitigate the disturbance of the surrounding ground due to the earth pressure around the caisson body 1 acting in a wedge shape, and thus the caisson body 1 can be subsided in a stable state. It will be possible. Moreover, the oxygen-deficient air in the caisson frame 1 is pushed out by the air blown into the work chamber below the caisson frame 1 to leak into nearby wells and ponds, which adversely affects the surrounding environment. Can be eliminated.

Further, in the present invention, a steel blade member 3 is fixed to the blade portion 2 of the caisson body 1. And
The blade fitting 3 is provided with the air intake 4 and the air chamber 5. As a result, the air intake port 4 and the air chamber 5 having the above-mentioned functions can be accurately formed in the caisson body 1.

Further, in the present invention, since the filter 6 is arranged in the air chamber 5, it is possible to prevent clogging of the air chamber 5 and the air passage 7 due to the earth and sand.

[0015]

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

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention, and FIG. 2 is an enlarged perspective view of a main part.

In the embodiments shown in these drawings, a steel blade fitting 3 is fixed to a blade opening 2 of a caisson body 1.

As shown in FIG. 2, the blade fitting 3 has
An air intake port 4 and an air chamber 5 are provided at a predetermined interval.

In the embodiment shown in the drawings, the air intake port 4 is formed as an elongated rectangle having a width of 5 mm and a height of 50 mm, but it may be an ellipse, an ellipse or a circle.

A filter 6 is arranged in the air chamber 5. The filter 6 is made of gravel, synthetic resin fiber, or the like, and prevents dirt and sand from entering the members after the air chamber 5.

An air passage 7 is connected to the air chamber 5 through the inside of the side wall of the caisson body 1.
The air passages 7 are formed by, for example, vinyl chloride air pipes, and a plurality of air passages 7 are provided inside the side wall of the caisson body 1 at predetermined intervals in the circumferential direction. The upper end of the air passage 7 extends to the ground so that the air can be released to the atmosphere. Further, a valve 8 is provided at the upper end of each air passage 7.

A working chamber 10 is formed on the lower side of the caisson body 1 as shown in FIG. Compressed air is supplied to the working chamber 10 and is kept in a pressurized state of a predetermined pressure. Also, a hole 11 is provided in the ceiling slab of the work room 10.
Is provided. A shaft 13 provided inside the caisson body 1 is connected to the hole 11. An upper lock 12 is attached to the upper end of the shaft 13, and an arm hatch 16 is provided to the lower end. The upper lock 12 includes an upper hatch 14 and a lower hatch 1.
5 are provided.

When the caisson skeleton body 1 is submerged by the pneumatic caisson method, the working chamber 10 is kept under a predetermined pressure. In this state, the ground G at the bottom of the working chamber 10 is excavated by an automatic excavator (not shown). When carrying out the excavated earth and sand to the ground, the upper hatch 14 provided in the upper lock 12 is opened, the earth and sand bucket (not shown) is put in the upper lock 12, and the inside of the upper lock 12 is pressurized. When the pressures of the upper lock 12 and the working chamber 10 become the same, the lower hatch 15 of the upper lock 12 is opened, and the earth and sand bucket is passed through the shaft 13 and lowered into the working chamber 10. Then, the earth and sand excavated in the working room 10 is put into the earth and sand bucket by the automatic excavator, drawn into the upper lock 12 through the shaft 13, the lower hatch 15 provided in the upper lock 12 is closed, and the inside of the upper lock 12 is decompressed. Then, the earth and sand bucket is pulled up outside the box, and the excavated earth and sand is discharged.

After digging up to a predetermined depth in this way, the caisson frame 1 is submerged. When the caisson skeleton 1 is submerged, in this embodiment, the air around the caisson skeleton 1 is divided into a plurality of pieces provided on the blade fitting 3 of the blade opening 2 of the caisson skeleton 1 as shown by an arrow a in FIG. The air is taken into the air chamber 5 through the air intake 4, the soil is blocked by the filter 6 placed in the air chamber 5, and only the air is provided as an air passage 7 provided inside the side wall of the caisson body 1 with an air pipe and a valve. It is released through 8 into the atmosphere on the ground.

As a result, when the caisson body 1 is submerged,
The disturbance of the surrounding ground due to the earth pressure around the caisson body 1 acting like a wedge can be alleviated, and therefore the caisson body 1 can be sunk in a stable state.

Further, in this embodiment, the oxygen-deficient air in the caisson frame 1 is pushed out by the air blown into the working chamber 10 below the caisson frame 1 to leak into a nearby well, pond or the like, and the surrounding area. It is also possible to eliminate problems such as adversely affecting the environment.

In the present invention, the shapes and structures of the respective parts are not limited to the embodiments shown in the drawings, but may be any one having a desired function.

[0028]

As described above, according to the first aspect of the present invention.
In the described invention, a plurality of air intake ports 4 are provided on the outer periphery of the caisson body 1 at predetermined intervals, an air chamber 5 is provided inside the air intake port array, and the air chamber 5 is provided with the caisson body 1 of the caisson body 1. An air passage 7 for releasing air to the atmosphere on the ground through the inside of the side wall is connected, and the air around the caisson skeleton 1 is taken into the air chamber 5 through the air intake port 4, and the air passage from this air chamber 5 is taken. Since it is released to the atmosphere on the ground through 7, there is an effect that when the caisson skeleton body 1 is subsided, the turbulence of the surrounding rocks due to the wedge pressure of the earth pressure around the caisson skeleton body 1 can be alleviated. In addition to having the effect of sinking the caisson body 1 in a stable state, the caisson body 1
Oxygen-deficient air is pushed out by the air blown into the work chamber below the caisson frame 1 to leak into nearby wells, ponds, etc., which can eliminate problems such as adversely affecting the surrounding environment. There is also.

Further, in the invention according to claim 2 of the present invention,
Since the blade member 3 made of steel is fixed to the blade portion 2 of the caisson body 1 and the air intake port 4 and the air chamber 5 are provided in the blade body 3, the caisson body 1 has the above-mentioned function. There is an effect that the air intake port 4 and the air chamber 5 that are held can be accurately formed.

Further, in the invention according to claim 3 of the present invention, since the filter 6 is arranged in the air chamber 5, it is possible to prevent clogging of the air chamber 5 and the air passage 7 due to earth and sand. is there.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional side view showing one embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a main part of the embodiment shown in FIG.

[Explanation of symbols]

 1 Caisson skeleton 2 Blade edge of caisson skeleton 3 Blade metal 4 Air intake 5 Air chamber 6 Filter 7 Air passage 8 Valve provided at air side end of air passage 10 Working room

Claims (3)

[Claims] 1. A plurality of air intakes 4 are provided at predetermined intervals on the outer periphery of a caisson body 1, an air chamber 5 is provided inside the row of air intakes, and the air chamber 5 is provided with An apparatus for mitigating turbulence in the surrounding natural ground in a pneumatic caisson, which is connected to an air passage 7 that releases air to the atmosphere on the ground through the inside of the side wall. 2. A steel blade fitting 3 is fixed to a blade portion 2 of the caisson body 1, and the air intake 4 and an air chamber 5 are provided in the blade fitting 3. The disturbance mitigating device for the surrounding natural ground in the pneumatic caisson according to claim 1. 3. A turbulence alleviating device for surrounding natural ground in a pneumatic caisson as set forth in claim 1, wherein a filter 6 is arranged in said air chamber 5.