JPH047495A - Pressing and driving device for muddy water - Google Patents

Abstract

PURPOSE:To make it possible to form always a stabilized muddy film between a driving machine and a bedrock by providing a pressure control body to be elastically deformed in accordance with the variation in pressure of the inside of an excavation room to a partition wall of the excavation room, and operating a sludge withdrawal valve properly. CONSTITUTION:Pressure control body 13 of the inside of an excavation room 5 is constituted of a rigid body as a unit so that the excavation room 5 side is formed of an elastic body 13a and that the rear section side 3a is formed of a partition wall 3. Gas having the same extent of pressure as that of muddy water (a) is enclosed to the inside of the excavation room. After that, press-feed of the muddy water (a) is made through a sludge delivery pipe 4 to fill the excavation room 5, and it is delivered to the surface of a facing A. Then, the muddy water (a) is mixed with the earth excavated by a cutter section 8, and a muddy film is formed between the cutter section 8 and the facing A. Another moddy film is also formed between a tail boid section D and the peripheral bedrock B. According to the constitution, pres sure applied to the muddy films is equivalent to the pressure of a liquid mixture in the excavation room 5, so that the breakdown of the facing A and the peripheral bedrock B can be controlled to prevent the generation of loose earth pressure.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to the use of muddy water that excavates underground by forming a mud film between the front face of a cutter part and a face, and between a shield tube and an outer ground. It relates to a pressurized propulsion device.

[Conventional technology]

The muddy water pressure propulsion method is conventionally known as a construction method for underground horizontal hole excavation.

This construction method is as follows: - A vertical shaft is excavated to carry the excavator and buried pipes into the boat, and multiple buried pipes are sequentially connected behind the excavator while pushing the excavator and buried pipes laterally into the horizontal hole. Excavate the area, pull out the excavator from the reaching shaft installed at the specified location, and install the buried pipe.

Here, in the method of excavating a horizontal hole, mud is injected from an excavator toward the rock side of the face and pressurized to form a mud film on the rock side. Then, while the face is stably supported by a mud film pressurized to about +0.2 kg/cut of normal groundwater pressure, the cutter is rotated to excavate earth and sand from the ground and propelled. As the cutter, a spoke type cutter or a face plate type cutter having a cutter face is usually used.

FIG. 7 is a partial sectional view showing an example of a conventional excavator.

On the head side of the excavator 41 shown in the figure, the diameter of the cutter part 8 is formed larger than the diameter of the shield tube 2, and the cutter portion 8 is formed to overcut the ground slightly larger than the shield tube 2. A tail void C portion is formed between the buried pipe connected to the rear (not shown) and the ground.

On the other hand, a mud film is formed between the face A and the cutter part 80 by sending mud water a to the front surface of the cutter part 8 from the mud feed pipe 42, and the face A is stably supported. The earth and sand excavated by the cutter section 8 is stirred and mixed with mud feeding water in the excavation chamber 5 to become a highly concentrated liquid.

By filling the tail void C section with this highly concentrated liquid under pressure, the ground is placed in a pressure-receiving state, suppressing the collapse of the ground and tightening of the buried pipe, and preventing the excavation machine, the buried pipe, and the ground from collapsing. This reduces the friction between the buried pipe and the ground by preventing direct contact between the underground pipe and the ground.

In the figure, 10 is a mud draining port, 11 is a mud draining pipe, and 43 is a valve.

In this way, the propulsion device using an excavator in which the cutter 8 part has a larger diameter than the shield tube 2 enables long-distance propulsion with lower thrust than previous propulsion devices without an overcut. .

[Problem to be solved by the invention]

As mentioned above, the mud water pressurization propulsion method creates a mud film between the cutter and the face and between the shield tube and the outer ground by injecting mud under pressure from an excavator toward the rock side of the face. The cutter is rotated to excavate and propel the face while stably supporting the face and the surrounding ground by the pressure applied through the mud film.

In this mud water pressurization propulsion method, it is extremely important to maintain the pressurizing force through the mud film within a certain range in order to stably support the face and the surrounding ground. The problem here is the drop in pressure at the face due to mud removal work. Naturally, excavation cannot be carried out unless the excavated soil is discharged, so excavation and mud removal work are repeated. In conventional work, the valve installed in the sludge pipe is opened and closed only when the pressure at the face is the lower limit (groundwater pressure + 0.2 kg/Cn).
t) The pressure at the face was controlled by opening the valve when the pressure was higher and closing it at the lower limit, but the face pressure often fell below the set lower limit, making it difficult to stabilize the face and tail void. On the other hand, if the face pressure when opening the valve is set high, the mud film that has been formed will be broken due to the high face pressure and mud will escape, causing the face pressure to drop all at once and making the face unstable. Occurred.

Further, as a valve installed in the sludge drainage pipe, an air pinch valve 43 is provided, in which a rubber sleeve 43b is attached to a casing 43a as shown in FIG. 8, and the rubber sleeve 43b opens and closes by supplying air at a predetermined pressure into the casing 43a. When used, when this valve 43 is closed, the same figure (a) (front sectional view) and the same (
b) (side cross-sectional view), when the lump of earth and sand 44 being drained is sandwiched between the rubber sleeves 43b as shown in Figure (C) (side cross-sectional view), the area around the earth and sand 44 is A large gap 45 may be created and the valve 43 may not be completely closed, allowing muddy water to leak. For this reason, there was a problem in that the valve 43 was not operated properly, causing pressure fluctuations within the excavation chamber.

Furthermore, if the rubber sleeve 43b is damaged, there is a problem in that muddy water flows out and the face pressure decreases, causing the face to collapse.

Therefore, in the mud water pressurization propulsion method, the present invention suppresses pressure fluctuations in the excavation chamber and properly operates the mud drainage valve to form a stable mud film at all times between the excavator and the ground. The purpose is to facilitate long-distance excavation.

[Means to solve the problem]

In order to achieve the objective, the mud water pressurization propulsion device of the present invention forms a mud film between the front surface of the cutter portion, which has a diameter larger than the shield tube, and the face, and between the shield tube and the outer ground. The mud water pressurization propulsion device for digging underground is characterized by having one or more of the following means (1) to (4).

(1) A pressure regulator that elastically deforms in response to pressure changes within the excavation chamber is provided on the partition wall provided at the rear of the cutter section to form the excavation chamber of the excavation machine.

(2) The valve installed in the middle of the mud removal pipe connected to the excavation chamber of the excavator is an air pinch valve with a rubber sleeve attached inside the casing, and when the rubber sleeve is closed, the cross-sectional shape of the rubber sleeve is radial. Provide air supply ports at three or more locations in the circumferential direction of the casing.

(3) A plurality of the air pinch valves are installed in series.

(4) The casing of the air pinch valve is made of hard rubber, and the casing has a structure that can be pressed from the outside.

[Effect]

In the mud water pressurization propulsion device of the present invention, the pressure regulating body provided on the partition wall forming the excavation chamber is designed to prevent the pressure increase in the excavation chamber from increasing when a large lump of excavated soil enters the excavation chamber. In response to the pressure drop at the time of shrinkage and the start of sludge removal, the pressure regulating body expands to absorb pressure fluctuations within the excavation chamber and maintain the interior of the excavation chamber at a predetermined pressure at all times.

The air pinch valve installed in the mud removal pipe prevents the rubber sleeve from becoming deformed and creating gaps even when the rubber sleeve gets caught in a lump of earth and sand. Further, when a plurality of the same air pinch valves are arranged in series, the pressure inside the excavation chamber can be reliably maintained at a predetermined pressure by appropriately setting the supply air pressure of each valve. In addition, if the casing of the air pinch valve is made of hard rubber and has a structure that allows the casing to be pressed from the outside, if the rubber sleeve inside the casing is damaged, the casing must be pressed to close the valve. I can do it.

〔Example〕

Hereinafter, the features of the present invention will be specifically explained using examples with reference to the drawings.

FIG. 1 is a sectional view showing the main parts of an excavator in an embodiment of the present invention.

In FIG. 1, the excavator 1 has a cylindrical shape as a whole, and a plurality of buried pipes (not shown) are successively connected to the rear of the excavator 1.

A partition wall 3 is provided inside the shield tube 2 of the excavator 1. A mud feeding pipe 4 is connected to the rear side of the partition wall 3. This mud feeding pipe 4 is connected to a muddy water storage tank (not shown) via a pump that pumps muddy water a. On the front side of the bulkhead 3, there is a rotating shaft 7 to which rotational force is applied by a drive device 6 such as a motor, and a rotating shaft 7 that is connected to the rotating shaft 7 and has an outer diameter larger than the outer diameter of the shield tube 2 of the excavator 1. A cutter section 8 is provided. Cutting blades 81 are arranged radially on the front surface of the cutter part 8, and the outermost cutting blade 81 is connected to the shield tube 2.
A tail void portion C is formed in the gap between the shield tube 2 and the outer periphery ground B.

A space surrounded by the partition wall 3, cutter section 8, and shield tube 2 of the excavator 1 is an excavation chamber 5 where muddy water and excavated earth and sand are stirred and mixed.
It becomes.

In this excavation chamber 5, a scraper 9 is provided protruding from the back surface of the cutter section 8 in parallel to the axis of the rotating shaft 7. The scraper 9 scrapes off the earth and sand that tends to remain on the inner surface of the shield cylinder 2, and also stirs and mixes the excavated earth and sand and the muddy water a.

Then, in the cutting section on the front surface of the cutter section 8 and the excavation chamber 5, the liquid mixture created by uniformly stirring and mixing the muddy water a and the excavated soil forms a mud film on the face Δ side on the front surface of the cutter section 8. At the same time, a tail void portion C is formed between the shield tube 2 and the outer circumferential ground B. A mud film is also formed in this tail void portion C.

In the lower part of the excavation chamber 5, a part of the partition wall 3 is opened,
A mud drain port 10 is formed. This mud drainage port 10 is provided with a mud drainage pipe 11 and a valve 12, and further includes a valve 1.
A mud storage tank (not shown) is installed at the end of No. 2 on the mud removal side.

In this embodiment of the excavator 1, the partition wall 3 is provided with a pressure regulator 13 that elastically deforms in response to changes in the pressure within the excavation chamber 5. This pressure adjusting body 13 has an elastic body 13a made of rubber or the like on the side of the excavation chamber 5, and a rigid body integrally formed on the rear side 3a with the partition wall 3, so that the pressure inside the body is equal to the pressure of the muddy water a inside the excavation chamber 5. It is filled with a gas such as air at a pressure of .

Next, the operation of the excavator 1 shown in FIG. 1 will be explained.

First, muddy water a is pumped through the mud feeding pipe 4 by a pump (not shown). The pumped mud water a fills the excavation chamber 5 and is sent to the face A surface under pressure. Next, the rotary shaft 7 is rotated by the driving machine 6, and the cutter section 8 excavates while continuing to pour the muddy water a. The excavated earth and sand are mixed with mud water a, and this liquid mixture presses the face A of the face A, and a mud film is formed between the cutter part 8 and the face A.
stability will be achieved.

Furthermore, since the outer diameter of the cutter section 8 is set larger than the outer diameter of the shield tube 2, a tail void section C is formed between the outer periphery of the shield tube 2 and the buried pipe and the outer circumferential ground B after excavation. . A mud film is also formed between this tail void portion C and the outer circumferential ground B.

The pressure applied to this mud film is the same as the pressure of the liquid mixture in the excavation chamber 5, for example, groundwater pressure + 0.2 kg/cut, and its pressing force suppresses the collapse of the face A and the surrounding ground B and loosens it. The generation of earth pressure is prevented, and the required propulsion force of the excavator is reduced by eliminating the tightening of buried pipes, etc. in the outer ground B. Therefore, the excavator can be propelled with a small propulsion force, making it suitable for long-distance propulsion construction methods.

The liquid mixture of earth and sand and muddy water a in the excavation chamber 5 is discharged through the mud draining port 10.
The sludge is drained from the sludge through a sludge pipe 11 and a valve 12 into a sludge storage tank (not shown). By appropriately adjusting the opening/closing operating pressure of this valve 12, it becomes possible to maintain the pressure of the liquid mixture in the excavation chamber 5 for performing good excavation.

During the above-mentioned excavation work, when a relatively large lump of excavated soil enters the excavation chamber 5, the pressure inside the excavation chamber 5 temporarily increases by an amount corresponding to the volume of this lump, and the excavation chamber 5 Pressure fluctuations occur within the mud film, making it unstable. However, in this embodiment, the pressure adjusting body 13 that is elastically deformed on the partition wall 3
, the volume of gas such as air in the pressure regulator 13 is reduced by an amount corresponding to the pressure increase, and the pressure in the excavation chamber 5 does not increase. After the lumps are drained from the mud drain port 10, the slurry returns to its original state, so that a stable mud film is maintained. In addition, when the pressure at the face decreases due to mud removal or when the pressure decreases during abnormal conditions, this pressure regulator 13 expands and follows the volume change, preventing the pressure decrease at the face, and when the pressure becomes normal, it returns to its original state. return to the state.

FIG. 2 is a diagram illustrating a different configuration example of the elastically deformable pressure adjusting body. In this example, the pressure regulator 14 is arranged in a bag-like part 14a made of an elastic material such as rubber and arranged on the convex part 3b of the partition wall 3.
It is composed of a pipe 14b connected to the bag-shaped portion 14a, a pressure adjustment gauge 14c, and a valve 14d.

In this configuration, the valve 14[j is operated by the pressure adjustment gauge 14c so that the pressure of the gas such as air in the bag portion 14a is constant. And always the same figure (
In the state shown in a), if a relatively large lump of excavated soil enters the excavation chamber 5, the bag-shaped portion 14a will be in the state shown in the figure (b).
), it is elastically deformed to absorb the pressure increase inside the excavation chamber 5. At this time, a part of the gas in the bag-shaped portion 14a is released through the valve 14d.

When the lump of earth and sand is discharged from the excavation chamber 5, gas is supplied to the bag-shaped portion 14a through the valve 14d, and the state as shown in FIG. 2(a) is restored.

FIG. 3 is a diagram showing still another example of the configuration of the pressure regulator. In this example, the pressure regulator 15 is a disk 15 that slides like a piston on the inner surface of a convex portion 3c formed by forming the partition wall 3 into a cylindrical shape.
The piston head 15c is connected to the rod 15b and reciprocates within the fluid pressure cylinder 15d.

The left side of the fluid pressure cylinder 15d in the figure communicates with the outside air, and the right side of the fluid pressure cylinder 15d communicates with the liquid tank 15e. Air at a predetermined pressure is sealed inside the liquid tank 15e, and is normally in the state shown in FIG. If a relatively large lump of excavated soil enters the excavation chamber 5, the disc 1
5a, rod 15h, and piston head 15C are shown in the same figure (b
), it moves to the right in the figure to absorb the pressure increase in the excavation chamber 5. When the earth and sand lumps are discharged from the excavation chamber 5, the disk 15a, rod 15b, and piston head 15c return to the state shown in FIG.

FIG. 4 is a diagram showing the structure of the valve 12 provided in the mud removal pipe 11 in the embodiment shown in FIG. In this example,
The valve 12 is shown in Fig. 4 (a), (b), (C) (7).
As shown in Example 2, there are three or more air supply ports 12c into the casing 12a, and the rubber sleeve 12b has a radial cross-sectional shape when the valve 12 is closed. For this reason, the rubber sleeve 12b
Even if the rubber sleeve 12b is caught in the lump 20
It adapts to the environment and does not deform and create gaps, preventing muddy water from leaking. At this time, the casing 12 &
If the rubber sleeve 12b is fixed at three or more points, the rubber sleeve 12b will not separate from the casing 12a at the fixed points, and the rubber sleeve 12b will reliably take on a radial cross-sectional shape and be closed. .

FIG. 5 is a diagram showing an embodiment in which the valve provided in the sludge pipe is a double valve. In this example, the first valve 1
6 and a second valve 17 are connected in series, the first valve 16 is supplied with air at a pressure P from the supply port 16c, and the second valve 17 is supplied with air at a pressure P2 from the supply port 17c. . In the figure, 16a, 17a are casings, 16b, 1
7b is a rubber sleeve, and 16d and 17d are pressure gauges. In this double valve, the air pressure of the valve 16 is set to be about the same as the pressure inside the excavation chamber 5, as in the case of FIG.
The air pressure of the valve 17 is made slightly higher than the air pressure of the valve 16.

In FIG. 5, (a) shows a state in which both valves are closed, and (b) to (C) show the procedure for operating the valves during mud removal. When the excavation progresses and the pressure inside the excavation chamber 5 becomes higher than the predetermined pressure, the first valve 16 is automatically opened (see FIG.
b) condition). Seeing the increase in the pressure displayed on the pressure gauge 166 at this time, the operator lowers the air pressure supplied to the second valve 17 and opens the second valve 17 (the state shown in FIG. 3(C)).
. In this state, the liquid mixture in the excavation chamber 5 is drained. As the mud removal progresses, the pressure inside the excavation chamber 5 decreases, and when the pressure falls below a predetermined pressure, the first valve 16 automatically closes and the mud removal stops (the state shown in FIG. 3(d)). Thereafter, the operator closes the second valve 17 to return to the state shown in FIG. 2(a). In this way, the mud removal valve is a double valve, and the pressure displayed on the pressure gauge of the first valve 16 is monitored, and the pressure of the second valve 17 is monitored.
By opening and closing the second valve 17,
Even if there is a delay in closing the excavation room 5,
The internal pressure will never be lower than a predetermined pressure, thereby stably supporting the face and preventing the face from collapsing.

FIG. 6 is a diagram showing an embodiment of a valve installed in a mud drainage pipe, in which a casing is formed of hard rubber and the casing can be pressed from the outside; FIG. 6(a) is a front sectional view; Figure (b) is a side sectional view, and Figure (C) is a side sectional view showing the state in which the casing is pressed. In this example, the main body of the valve 21 consists of a hard rubber casing 22 and a rubber sleeve 23, and a hydraulic cylinder 24 presses the casing 22 against the main body from the outside.
has been established. In normal operating conditions, the rubber sleeve 23 is opened and closed by supplying air at a predetermined pressure between the casing 22 and the rubber sleeve 230. If the rubber sleeve 23 is damaged for some reason during operation, the fluid pressure cylinder 24 is operated to press the casing 22 with the presser 25 at the tip of the cylinder rod to bring the entire pulp 21 into close contact and prevent muddy water from flowing out. .

The embodiments described above are for the purpose of forming a stable mud film between the excavator and the ground in the mud water pressurization propulsion method to facilitate long-distance excavation. (4)
Although examples of combinations of means are shown, combinations other than those in the embodiments can be selected as appropriate for the pressurized propulsion device of the present invention.

〔Effect of the invention〕

As explained above, according to the mud water pressurization propulsion device of the present invention, the pressure of the mixture of mud water and excavated soil in the excavation chamber and between the shield tube and the outer ground is maintained within a predetermined range, and the cutter Fluctuations in the pressure applied to the mud film formed on the front surface of the shield tube and the outer periphery of the shield cylinder are minute, and the face and the outer ground are stably supported. This allows stable long-distance excavation work. Further, each means that can be adopted in the device of the present invention has the following individual effects.

■ When a pressure regulator is installed on the bulkhead that forms the excavation chamber, and the pressure regulator deforms elastically in response to changes in the pressure inside the excavation chamber, the pressure regulator will respond to the increase in pressure when a large lump of excavated soil enters the excavation chamber. shrinks and absorbs the pressure rise inside the excavation chamber, constantly maintaining the predetermined pressure inside the excavation chamber and stabilizing the support of the face. Conversely, in response to a drop in pressure at the start of mud removal, the pressure regulating body expands to prevent the pressure drop in the excavation chamber and prevent the face and tail void from collapsing.

■ When the valve installed in the mud removal pipe is an air pinch valve in which the cross-sectional shape of the rubber sleeve becomes radial when the rubber sleeve is closed, the rubber sleeve does not blend into the dirt even when the rubber sleeve gets caught in a lump of dirt. It does not deform and create gaps, and there is no leakage of muddy water.

■ When two air pinch valves are installed in series as valves on the mud removal pipe, the pressure inside the excavation chamber can be reliably maintained at the specified pressure by appropriately setting the supply air pressure of each valve. It is possible to prevent the face from collapsing.

■ When the casing is made of hard rubber and the casing is constructed to be able to be pressed by fluid pressure as a valve installed in the mud drainage pipe, even if the rubber sleeve inside the casing is damaged, muddy water can be prevented from flowing out, and the face can be prevented. Collapse can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the main parts of the excavator in the embodiment of the present invention, Figs. 2 and 3 are views showing different configuration examples of the elastically deformable pressure regulating body, and Fig. 4 is a sectional view showing the main parts of the excavator in the embodiment of the present invention. FIG. 5 is a diagram showing the structure of the valve provided, FIG. 5 is a diagram showing the same double valve, and FIG. 6 is a diagram showing another example of the structure of the same valve. On the other hand, FIG. 7 is a sectional view showing an example of a conventional excavator, and FIG. 8 is a diagram for explaining problems with the conventional mud drain valve. 1.41: Excavation machine 2: Shield tube 3: Bulkhead
3a: Rear side of bulkhead 3b, 3c: Convex portion of bulkhead 4, 42: Sludge pipe 5: Excavation chamber 6:
Drive machine 7 - rotating shaft 8; cutter part 81: cutting blade
9: Scraper 10: Mud removal port 1
1: Sludge pipe 12, 16.17.43: Valve 12a, 16a, 17a, 43a: Casing 1
2b, 16b, 17b, 43b: Rubber sleeve 1
2c, 16c, 17c: Air supply ports 13, 14.1
5: Pressure adjustment body 13a: Elastic body 14a: Bag-shaped part
14b: Piping 14C: Pressure adjustment gauge 14d: Valve 15a: Disc 15b: 07 de 15C
: Piston head 15d: Fluid pressure cylinder 150:
Liquid tank 16[], 17d: Pressure gauge 20,
44: Mass of earth and sand 21: Valve 22: Casing
23: Rubber sleeve 24: Fluid pressure cylinder 2
5: Holder 45: Gap A: Face B: Outer ground C: Tail void part a: Mud water

Claims (1)

[Claims] 1. A mud water pressurization propulsion device that excavates underground by forming a mud film between the face and the front face of a cutter portion having a diameter larger than that of the shield tube, and between the shield tube and the outer ground. Pressurized mud water propulsion, characterized in that a pressure regulating body that elastically deforms in accordance with pressure changes in the excavation chamber is provided on a partition wall provided at the rear of a cutter part to form an excavation chamber of an excavation machine. Device. 2. In a mud water pressurization propulsion device that excavates underground by forming a mud film between the front surface of the cutter portion, which has a larger diameter than the shield tube, and the face, and between the shield tube and the outer ground, the excavation machine The valve installed in the middle of the sludge drainage pipe connected to the room is an air pinch valve with a rubber sleeve attached inside the casing, and the cross section of the rubber sleeve is radial when the rubber sleeve is closed. A mud water pressurization propulsion device characterized by having air supply ports at three or more locations. 3. A mud water pressurization propulsion device comprising a plurality of air pinch valves according to claim 2 arranged in series. 4. A mud water pressurization propulsion device, characterized in that the casing of the air pinch valve according to claim 2 or 3 is made of hard rubber, and the casing has a structure that can be pressed from the outside. 5. A mud water pressurization propulsion device that excavates underground by forming a mud film between the front surface of the cutter portion having a diameter larger than that of the shield tube and the face, and between the shield tube and the outer surrounding ground, as set forth in claim 1. A mud water pressurization propulsion device, characterized in that it is provided in an excavator by combining the pressure regulating body and the air pinch valve according to any one of claims 2 to 4.