JPH0718315B2 - Muddy water pressure propulsion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to the production of underground tunnels, burial of sewer pipes, communication lines,
A device for excavating a lateral hole in the ground for burying power lines, etc., in particular, a mud slag that excavates underground by forming a mud film between the front face of the cutter and the face and between the shield cylinder and the outer ground. Pressure propulsion device.

[Conventional technology]

There is a muddy water pressure propulsion method as a method of excavating the underground horizontal hole. The construction method is generally to excavate a shaft for loading the excavator and the buried pipe, and to push the excavator and the buried pipe laterally while sequentially connecting a plurality of buried pipes behind the excavator, The excavator is pulled out from the reaching shaft provided at the location, and the buried pipe is installed.

The method of excavation is to inject mud water and pressurize it to form a mud film (mud film) on the ground side, and the face pressure is applied through the mud film (usually groundwater pressure + 0.2 kg / cm ² ) While stabilizing, the cutter is rotated to excavate the earth and sand from the natural ground and promote it.

As the cutter, a spoke type cutter or a face plate type cutter having a cutter face is usually used.

FIG. 8 is a sectional view of an essential part showing an example of a conventional excavator.

On the head side of the machine 41 shown in the figure, the diameter of the cutter portion 8 is formed to be larger than the diameter of the shield cylinder 2, and the ground is slightly overcut compared to the shield cylinder 2, and the shield cylinder 2 and the illustration are shown. A tail void C portion is formed between the buried pipe connected to the rear and the ground.

On the other hand, by sending muddy water from the mud pipe 4 to the front surface of the cutter unit 8, a mud film is formed between the face A and the cutter unit 8, and the face A is stably supported. The earth and sand excavated by the cutter unit 8 is agitated and mixed with the mud water in the excavation chamber 5 to become a high-concentration liquid material. By filling the tail void C portion with this high-concentration liquid under pressure, the ground is put into a pressure receiving state, the collapse of the ground and the tightening to the buried pipe are suppressed, and the excavator and the buried pipe and the ground are separated. Not touch it directly,
The frictional force between the buried pipe and the ground is reduced. In addition, 10 in the figure
Is a mud outlet, 11 is a mud pipe, and 12 is a mud valve.

As described above, the propulsion device using the excavator in which the cutter portion 8 has a diameter larger than that of the shield cylinder 2 enables long-distance propulsion with low thrust as compared with the conventional propulsion devices without overcut. .

[Problems to be Solved by the Invention]

However, in the propulsion work using the above-mentioned excavator, the following problems occurred.

The high-concentration liquid material is produced by mixing mud water and excavated earth and sand in the excavation chamber. At this time, if the mixing ratio of mud water is poor, for example, if the proportion of fine particles is small,
The liquid in the tail void portion was easy to separate, and the ground was likely to collapse, and the ground often tightened the shield cylinder and the buried pipe, resulting in a large thrust.

Since the mixing of sewage water and excavated soil is performed by using the rotation of the cutter part, the tail void part is outside the shield cylinder, so the degree of mixing tends to be worse than in the excavation chamber,
Tightening occurred due to the collapse of the ground, and coarse particles of the ground remained in the tail void portion as they were, which hindered liquefaction of the tail void and increased thrust.

Regarding the pressure control between the face and the front of the cutter, the lower limit is usually groundwater pressure + 0.2 kg / cm ² , the upper limit is groundwater pressure + 0.5-0.7 kg / cm ²
Perform within a range of degrees. Face pressure is groundwater pressure + 0.5-0.7kg
When it reaches about / cm ^{2, the} drainage valve is opened and groundwater pressure + 0.2kg /
Close the mud discharge valve before reaching cm ² . At that time, the pressure of the liquid material in the tail void portion also fluctuates with the sludge, and the liquid material in the tail void portion tends to flow toward the sludge discharge port, and the stability of the tail void portion is impaired by the movement of the liquid material, It often caused an increase in thrust.

Therefore, an object of the present invention is to reliably stabilize the liquid material in the tail void portion in the muddy water pressure propulsion method, and to perform long-distance propulsion more smoothly.

[Means for Solving the Problems]

In order to achieve the object, the muddy water pressure propulsion device of the present invention uses an excavator having a cutter portion having a diameter larger than that of a shield cylinder, and while sequentially connecting a plurality of buried pipes to the rear of the excavator, Extruding the excavator and the buried pipe laterally from the rear end of the buried pipe, stirring and mixing with the mud water in the excavation room while excavating the ground with the cutter part, and between the shield cylinder and the outer ground By injecting a liquid material into the tail void portion formed in the state under pressure, a mud film is formed between the front surface of the cutter portion and the face and between the shield cylinder and the outer peripheral ground to prevent the ground from collapsing. A mud pressure propulsion device for digging into the ground while preventing is provided with any one or more of the following means.

(1) A plate member for mixing the liquid material in the tail void portion is provided on the outer periphery of the cutter portion toward the rear of the excavator.

(2) The plate-shaped members are provided in a plurality of steps on the outer periphery of the cutter portion toward the rear of the excavator.

(3) A weir for holding the liquid in the tail void portion is provided on the outer circumference of the shield cylinder.

(4) Rotating stirring blades for stirring the liquid in the tail void portion are provided at the rear part of the shield cylinder and the outer circumference of the buried pipe.

(5) Provide a pipe for supplying the separately mixed liquid material to the tail void portion.

[Action]

In the muddy water pressure propulsion device of the present invention, the plate-shaped member for mixing the liquid material in the tail void portion is provided on the outer periphery of the cutter portion, so that the excavated earth and sand and the muddy water in the tail void portion are reliably mixed. Further, when the plate-shaped member is provided, for example, in two steps on the outer circumference of the cutter portion, the liquid material in the tail void portion is more reliably mixed, and further, another pipe for supplying a plastic material to the tail void portion is provided. By providing the liquid of the tail void portion has a two-layer structure, a layer for reducing the frictional force between the natural ground and the shield cylinder and the buried pipe, and a layer for stabilizing the other tail void portion. Is configured, and the stability of the tail void portion is ensured. Further, by providing a weir for holding the liquid material in the tail void portion on the outer periphery of the shield cylinder, it is possible to prevent the liquid material in the tail void portion from flowing toward the mud discharge port every time the mud is discharged, and at the rear part of the excavator or The liquid material separately supplied from the embedded pipe to the tail void portion can be held with a constant thickness. Further, by providing the rotary stirring blades at the rear part of the shield cylinder and the outer circumference of the buried pipe, mixing of the liquid material in the tail void portion between the shield cylinder and the outer peripheral ground and pushing of the liquid material to the rear can be effectively performed. In addition, even if the liquid in the tail void portion becomes plastic with the passage of time, it is fluidized again by the rotation of the rotary stirring blades, and the liquefaction in the tail void portion is regenerated to reduce the necessary thrust and smooth the length. Enables distance promotion.

〔Example〕

Hereinafter, the features of the present invention will be specifically described by way of examples with reference to the drawings.

FIG. 1 is a sectional view showing a main part of an excavator in an embodiment of the present invention, and FIG. 2 is a sectional view taken along line I-I of FIG.

In FIGS. 1 and 2, the excavator 1 has a tubular shape as a whole, and a plurality of buried pipes (not shown) are provided behind the excavator 1.
Are sequentially connected.

A partition 3 is provided in the shield cylinder 2 of the excavator 1. A mud pipe 4 is connected to the rear side of the partition wall 3.
The mud pipe 4 is connected to a mud storage tank (not shown) via a pump that pumps the mud a. On the front side of the partition wall 3, a rotary shaft 7 which is given a rotational force by a driving machine 6 such as a motor, and is connected to the rotary shaft 7 and has an outer diameter larger than the outer diameter of the shield cylinder 2 of the excavator 1. A cutter unit 8 is provided. Cutting blades 81 are radially arranged on the front surface of the cutter portion 8, the outermost cutting blades 81 are located outside the shield cylinder 2, and a tail void is formed in a gap between the shield cylinder 2 and the outer peripheral ground B. C is formed.

A space surrounded by the partition wall 3, the cutter portion 8 and the shield cylinder 2 of the excavator 1 is an excavation chamber 5 in which muddy water and excavated earth and sand are mixed.

In the excavation chamber 5, a scraper 9 is provided so as to project from the back surface of the cutter 8 in parallel with the axis of the rotary shaft 7. The scraper 9 scrapes off the earth and sand that tends to remain in the excavation chamber 5 and also mixes the excavated earth and mud water a.

Then, in the cutting portion on the front surface of the cutter portion 8 and in the excavation chamber 5, the liquid material formed by uniformly mixing the muddy water a with the excavated earth and sand forms a mud film on the face A side of the front surface of the cutter portion 8. A tail void C filled with a mud film is formed between the shield tube 2 and the outer peripheral ground B.

In the lower part of the excavation chamber 5, a part of the partition wall 3 is opened,
A sludge discharge port 10 is formed. A sludge pipe 11 is provided in this sludge discharge port 10.
Further, a mud discharge valve 12 is provided in communication with the mud discharge valve 12, and a mud storage tank (not shown) is installed at the end of the mud discharge valve 12 on the mud discharge side.

In the excavator 1 as described above, in this embodiment, a dam plate 21 having a constant thickness (about 20 to 30 mm) is provided on the front part of the shield cylinder 2 so as to cover the outer periphery of the front end part of the shield cylinder 2. Dam plate
21 is made of steel, hard rubber having high rigidity, or synthetic resin. This dam plate 21 responds to the movement and backflow of the liquid in the tail void C portion due to the pressure drop at the time of sludge discharge.
This is for maintaining the thickness (about 20 to 30 mm) of the tail void C portion necessary for reducing the frictional force between the shield tube 2 and the buried pipe.

In addition, a plate-like member 22 for mixing the liquid material in the tail void C portion is provided on the outer periphery of the cutter portion 8 toward the rear of the shield cylinder 2. When the liquid material in the tail void C portion is separated, the ground B is collapsed or soil particles are replaced, and the shield cylinder 2 and the buried pipe are tightened to increase the frictional force and the required thrust is increased. In order to prevent this, the liquid is constantly mixed by the plate member 22 by utilizing the rotation of the cutter unit 8.

Further, an injection pipe 4 _a for supplying the liquid material separately mixed outside the shaft from the rear of the machine 1 to the tail void C portion is provided at the rear portion of the shield cylinder 2. This is to stop supplying the mixture of the excavated soil and the mud water to the tail void C portion in the conventional excavation chamber 5, and to inject the liquid separately blended outside the vertical shaft into the tail void C portion. It is a thing. As described above, when the excavated soil and the mud water are mixed in the excavation chamber 5, the tail void C portion becomes unstable due to a liquid material that is easily separated due to a great influence on the mix of the mud water and the soil soil composition. Therefore, the required thrust increases and hinders long-distance propulsion. Therefore, in the present embodiment, a liquid material suitable for the tail void C portion is separately blended and supplied. The material of this liquid mixture dissolves powdered clay as solid particles for filling, Uragomer which enhances the filling effect, and CMC as a thickening agent in water. In addition, if the site soil is a sand layer, gravel, or cobblestone layer with a high hydraulic conductivity, fine sand with larger particles than powdered clay or perlite, a lightweight aggregate, is added to increase the mud film forming effect and to increase the water retention capacity by using a polymer. Add absorbent. This water retention agent has a role as a water supply source at the time of refluidization of the tail void C portion described later. The mixing ratio of these varies depending on the soil quality of the target rock mass, but the standard weight ratio is 100% water to 3% powdered clay.
0, Uragomer 1.2, CMC0.2, 5-10 for fine sand, 1-3 for lightweight aggregate, and 0.1-0.5 for polymer absorbent. Of course, other than this, it is possible to mix and use an appropriate material as the tail void material. Since this separately mixed liquid material (hereinafter referred to as tail void material α) also has an effective effect on the cutting face, it does not interfere even if a certain amount of water enters the excavation chamber 5 when the mud is discharged.

Injection tube 4 _a of the Teruboido material α is in the FIG. 1 are illustrated in the vertical, it is more effective by providing a plurality of places in e.g., left and right.

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

First, the muddy water a is pressure-fed through the mud feed pipe 4 by a pump (not shown). The pumped mud a fills the excavation chamber 5 and is sent to the face A face under pressure. Next, the rotating shaft 7 is rotated by the driving machine 6 and excavation is performed by the cutter portion 8 while continuing to inject the muddy water a. The excavated earth and sand are mixed with the muddy water a, and the face A is stabilized through the mud film formed by the muddy water a and the excavated earth and sand.

Moreover, since the outer diameter of the cutter portion 8 is set to be larger than the outer diameter of the shield cylinder 2, a tail void C is formed between the outer periphery of the shield cylinder 2 and the buried pipe and the outer peripheral ground B after excavation. The tail void material α is injected into the tail void C portion from the supply pipe 4 _a to form a mud film.

Incidentally, when a flanged shape to indicate the shape of the sheathing board 21 to the numbering 21 _a of FIG. 3 (a), it is possible to secure the holding of the liquid material Teruboido C unit.

Further, the shape of the plate-like member 22 for mixing liquid material Teruboido C unit, even when a third diagram (b) shape having a depending portion to the tip as shown in reference numeral 22 _a of Teruboido It is possible to more reliably hold the liquid material in the C portion. In this case, when the tail void material α flows linearly in the tail void C portion without being spread when it is injected from the rear side, the tail void material α is temporarily stopped by the dam plate 21 and the plate member 22 _a rotates. By doing so, it is possible to mix in the portion of the dam plate 21 to form a liquid material having a planar spread, and to make the uniform mixing of the tail void material α even more effective.

The liquid in the tail void C part has the same pressing force as the mud film in the cutter part 8, for example, the groundwater pressure +0.2 kg / cm ^2, and the pressing force suppresses the collapse of the outer peripheral ground B and generates loose earth pressure. Is prevented and the outer peripheral ground B is not tightened to the buried pipe or the like to reduce the thrust. Therefore, the thruster and the buried pipe can be propelled with a small thrust, which is suitable for the long-distance propulsion method.

The mixture of the earth and sand and the mud water a in the excavation chamber 5 is discharged from the mud discharge port 10 through the mud discharge pipe 11 and the mud discharge valve 12 into a mud storage tank (not shown).

FIG. 4 is a cross-sectional view showing a main part of the excavator in another embodiment of the present invention, and FIG. 5 is a view showing a cross section taken along line II-II of FIG. In these figures, the same members as those shown in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.

Excavator 31 of the present embodiment, provided with a plate-like member 22, 22 _b of the two-step toward the rear from the outer periphery of the cutter unit 8, the supply pipe for supplying the two types of formulation liquid material different to Teruboido C section _4b and _4c are provided.

In the case of normal soil, the thickness of the tail void C part is at least 20-
30mm is enough, but 50 ~ 100m for cobblestone gravel layer
If a thickness of about m is not secured, boulders and gravel will move after passing through the cutter, and will hit the shield tube 2 and the buried pipe, increasing thrust. Therefore, when propelling a cobblestone layer and a gravel layer,
It is necessary to increase the thickness of the tail void C portion. In this case, especially for the outer portion of the tail void C portion, it is necessary to take special measures in consideration of stability.

For this reason, in this embodiment, the mixing plate-shaped member provided on the outer periphery of the cutter portion has a two-stage structure, and the tail void C portion is provided with two different types of liquid mixture α and β separately supplied.
Inject from 4 _b and 4 _c to form a layer C ₁ for reducing the frictional force between the natural ground and the shield tube 2 and the buried pipe, and a layer C ₂ for stabilizing the outside thereof. I have to. And injecting a Teruboido material α of said from the supply pipe 4 _b is the C ₁ layer, another Teruido material from the supply pipe 4 _c is in C ₂ layers β
Inject. The tail void material β should be plastic compared to the tail void material α, and the standard is a two-component plastic material (sliding SS, clean F as a commercial product).
D, etc. are all trade names), or a so-called soil cement-based cement having about 40 of powdered clay and about 10 of cement with respect to 100 by weight of water is preferable. Of course, besides this,
Appropriate tail void materials can be blended and used. Tail void material α injected from supply pipe 4 _b
Are mixed in the plate-like member 22 _b, it covers the outer periphery of the shield tube 2 and buried pipe to form a C ₁ layer to reduce the frictional force between the natural ground and the shield tube 2 and buried pipes, supply pipes 4 _c The tail void material β injected from the above is mixed in the plate-shaped member 22 to form a C ₂ layer near the natural ground that stably holds the tail void C portion.

In FIG. 4 and FIG. 5, 21 is a dam plate provided on the outer periphery of the front end portion of the shield tube 2, and 21 _b is plate members 22 and 2
It is a weir that is located between 2 _b and covers the inlet of the supply pipe 4 _a and at the same time is provided to facilitate formation of the C ₁ layer and the C ₂ layer. The weir 21 _b, because those who provide a large number on the outer periphery of the shield tube 2 is easily formed by distinguishing C ₁ layer and C ₂ layers, hinder the formation of C ₁ layer when over the entire circumference, approximately 4-8 locations Is appropriate.

FIG. 6 is a cross-sectional view showing a main part of an excavator showing still another embodiment of the present invention, and FIG. 7 is a view showing a cross section taken along the line III-III in FIG.

The present embodiment is an example in which a rotary stirring blade as a refluidizing device for the liquid material in the tail void portion is installed at the rear part of the excavator shown in FIG.

In this embodiment, an annular rotary stirring blade 23 for stirring the liquid material in the tail void C portion is provided at the rear of the machine 1.
Is provided. In FIG. 6, for convenience, a part (upper half part in the drawing) of the rotary stirring blade 23 is shown in a cross section, and a part (lower half part in the drawing) is shown in appearance. The rotary stirring blade 23 is a motor 24 fixedly installed in the shield cylinder 2.
An annular body 27 with an internal gear 26 that rotates via a gear 25 by
A large number of blades 28 are attached to the outer periphery of the. This annular body 27 is rotatably installed at the rear of the shield tube 2 via a bearing 29 and a seal 30. This rotating stirring blade
The liquid in the tail void C portion is agitated by rotating for 23 times, and the tail void C portion is activated and reliquefied. At this time, if the blades 28 are attached at an angle in the axial direction of the shield cylinder 2, the liquid material is stirred and the liquid material is further pushed toward the rear connecting pipe.
Further, it is also effective to always operate during the propulsion so that the liquid material in the tail void C portion is always held. Further, it is more effective to provide the rotary stirring blade 23 not only in the rear part of the excavator but also in the buried pipe part.

The role of the rotary stirring blades 23 is formed until a long time has passed due to long-distance propulsion, the excavation of the reaching shaft has been delayed during the propulsion, or the propulsion has been stopped for a certain period of time for some other reason. If the liquid material of the tailoid C portion that had been used is plasticized or separated, and the frictional force between the shield tube 2 and the buried tube increases, the same rotary stirring blade 23 is operated to move the tail void material α. It is to liquefy again using water contained in the polymer absorbent. Of course, water and the tail void material α may be added separately.
Further, it is possible to prevent the plasticization of the liquid material in advance by always operating it during the propulsion.

Incidentally, in the embodiment described above, in the muddy water pressure propulsion method, the mud film is always formed in a normal state between the excavator and the ground, and the above-mentioned (1 ) To (5)
Although the example of the combination of the means is shown, a combination other than the combination of the embodiments can be appropriately selected as the pressure propulsion device of the present invention.

〔The invention's effect〕

As described above, according to the muddy water pressure propulsion device of the present invention, it is possible to form a stable mud film between the natural rock and the shield cylinder, and reduce the frictional force between the natural rock and the shield cylinder. Since it can be significantly reduced, epoch-making long-distance propulsion can be enabled as compared with the conventional muddy water pressure propulsion method. Each means that can be adopted in the device of the present invention has the following effects.

By providing a plate-shaped member on the outer circumference of the cutter for mixing the liquid in the tail void, the liquid in the tail void is mixed with the rotation of the cutter, and it is difficult to evenly separate it, and the ground collapses. The separation and settling of the liquid material in the tail void portion is prevented, and the frictional force between the ground and the shield cylinder and the buried pipe is reduced. Further, when the plate-shaped member has a shape having a hanging portion at the rear portion, the liquid material in the tail void portion can be made more uniform.

When the plate-shaped member provided on the outer periphery of the cutter is installed in two stages, the effect of the above item can be further enhanced, and at the same time, the tail void portion is stabilized by injecting two kinds of liquids having different formulations. It becomes easy to form a two-layer structure that reduces the frictional force.

By installing a weir at the front end of the shield tube, the liquid in the tail void part is prevented from flowing into the face and backflow due to the pressure fluctuation of the face during sludge discharge, and the liquid of the tail void has a certain thickness due to the weir. Held in. As a result, the shield cylinder and the buried pipe are covered with the liquid material with a thickness required to reduce the frictional force, low thrust is maintained, and long-distance propulsion becomes possible. When the weir has a flanged shape, the above effect can be further enhanced.

A more stable tail void portion can be formed by separately mixing a liquid material suitable for the soil quality of the site to be applied outside the vertical shaft and supplying it to the tail void portion. In particular, by injecting a liquid material with a suitable mixture into the shield tube of the tail void portion, the buried pipe side and the natural ground side,
A layer that secures the thickness of the tail void part that is difficult for boulders and boulders in the gravel layer to contact the shield tube and the buried pipe and that reduces frictional force and a layer that stably holds the outer ground This enables long-distance propulsion in a cobblestone and gravel layer with high thrust.

By providing rotary stirring blades on the rear part of the shield cylinder and on the outer circumference of the buried pipe, the plastic state of the liquid state of the tail void part is reactivated when a long time elapses due to long-distance propulsion.
In addition, it is possible to prevent plasticization and separation by constantly operating, and it is possible to stabilize the tail void portion for a long time. With conventional equipment, if you pause during propulsion, thrust will increase.Therefore, you need to push the friction cut at all times without rest, but with this equipment, such work becomes unnecessary and stable long-distance propulsion is achieved. Enforcement becomes possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of the excavator according to an embodiment of the present invention, FIG. 2 is a view showing a cross section taken along line II of the excavator of FIG. 1, and FIG.
(a) And (b) is a figure which shows another example of some members of the excavator of FIG. 1, FIG. 4 is sectional drawing which shows the principal part of the excavator of other Example of this invention, 5th FIG. 6 is a view showing a cross section taken along line II-II of the excavator of FIG. 4, FIG. 6 is a cross sectional view showing a main part of the excavator of still another embodiment of the present invention, and FIG. 7 is a excavation of FIG. FIG. 8 is a view showing a cross section taken along line III-III of the machine, and FIG. 8 is a cross sectional view showing an example of a conventional excavator. 1,31: shield machine, 2: shield tube 3: partition wall, 4: Okudorokan 4 _a, 4 _b, 4 _b: feed tube of the liquid material 5: Drilling chamber, 6: drive motor 7: rotation shaft 8: Cutter 9: Scraper, 10: Sludge outlet 11: Sludge pipe, 12: Sludge valve 21,21 _a , 21 _b : Dam plate, 22,22 _a , 21 _b : Plate member 23: Annular rotary blade, 24: Motor 25: Gear, 26: Internal gear 27: Annular body, 28: Blade 29: Bearing, 30: Seal A: Face, B: Outer ground C: Tail void, a: Muddy water α, β: Tail void material

Claims (5)

[Claims] 1. An excavator having a cutter portion having a diameter larger than that of a shield cylinder is used, and a plurality of embedded pipes are sequentially connected to the rear of the excavator while laterally extending from the rear end of the embedded pipe. Extruding a pipe, stirring and mixing with mud water in the excavation chamber while excavating the ground with the cutter part, and pressurizing the liquid material to the tail void part formed between the shield cylinder and the outer peripheral ground Muddy water pressure propulsion device for forming a mud film between the front face of the cutter and the face of the cutter and between the shield cylinder and the outer ground to prevent the ground from collapsing and to dig into the ground. The mud pressure propulsion device according to claim 1, wherein a plate-shaped member for mixing the liquid material in the tail void portion is provided on the outer periphery of the cutter portion toward the rear of the excavator. 2. The muddy water pressure propulsion device according to claim 1, wherein a plurality of plate-like members for mixing the liquid material in the tail void portion are provided on the outer periphery of the cutter portion. 3. A muddy water pressure propulsion device for digging into the ground by forming a mud film between a front face of a cutter portion having a diameter larger than that of a shield cylinder and a face, and between the shield cylinder and an outer ground. A muddy water pressure propulsion device, characterized in that a weir for holding the liquid material of the part is provided on the outer circumference of the shield cylinder. 4. A muddy water pressure propulsion apparatus for digging underground by forming a mud film between the front face of a cutter portion having a diameter larger than that of a shield cylinder and a face, and between the shield cylinder and the outer ground. A muddy water pressure propulsion device, characterized in that rotary stirring blades for stirring the liquid material in the above portion are provided at the rear portion of the shield cylinder and the outer circumference of the buried pipe. 5. A muddy water pressure propulsion apparatus for digging underground by forming a mud film between the front face of a cutter portion having a diameter larger than that of a shield cylinder and a face, and between the shield cylinder and the outer ground. A muddy water pressure propulsion device characterized in that a pipe for supplying a separately mixed liquid is provided in the section.