JP2648490B2 - Mud pressurization method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a muddy pressurized propulsion method for excavating an underground lateral hole while injecting muddy water from the front surface of a cutter section toward the ground.

[Conventional technology]

2. Description of the Related Art Conventionally, a muddy water pressure propulsion method has been known as a method of excavating an underground lateral hole.

This construction method generally excavates a shaft for carrying an excavator and a buried pipe, and extrudes the excavator and the buried pipe in the horizontal direction while sequentially connecting a plurality of buried pipes behind the excavator. It excavates, pulls out the excavator from the reaching shaft provided at a predetermined location, and installs a buried pipe.

Here, the method of excavating the side hole is to inject muddy water from the excavator toward the ground side of the face and pressurize to form a mud film (mud film) on the ground side. And, while stabilizing the face with the mud film normally pressurized to about 0.2 kg / cm ^{2 of} groundwater pressure, the cutter is rotated to excavate the earth and sand of the ground,
Promote. As the cutter, a spoke type cutter or a face plate type cutter having a cutter face is usually used.

For this mud pressurization propulsion method, the mud sent to the excavator is an important artery of the method. This is because, if the excavation is carried out without sending muddy water, the excavation room in the excavator is blocked by the excavated earth and sand and becomes unable to excavate, and the execution of the excavation work is fatally hit. In addition, the quantity and quality of the mud injected into the face is the most important factor that determines the state of the liquid material in the excavation room for the mud pressurized excavation method, and the stability of the face, favorable effect on propulsion and smooth It is the key for performing construction and the like.

As a prior art of this mud pressurization propulsion method, the injection point of the mud from the front of the cutter unit of the excavator is not one place but described in, for example, JP-A-56-28994 and JP-A-57-298. As described above, an excavator provided at a plurality of locations is known.

As shown in FIG. 3, the excavator is configured to transfer muddy water a from a mud feed pipe 50 through a hollow portion 51 of a rotary shaft 7 of the cutter unit 8 on the head side of the excavator 52, as shown in FIG. Is sent to a plurality of muddy water inlets 9 provided at the same time. The hollow portion 1 branches inside the cutter portion 8, and further branches into four muddy water inlets 9 in the illustrated example.

A cutting blade 81 is provided on the front surface of the cutter unit 8, and the rotating shaft 7 connected to the driving machine 6 rotates, and the cutter unit 8 rotates, so that the cutting wave 81 cuts earth and sand on the ground side. here,
The diameter of the cutter part 8 is formed larger than the diameter of the shield cylinder 4, and the excavated earth and sand is sufficiently stirred and mixed in the excavation chamber 15 by the muddy water a being sent from the outer muddy water inlet 9 to the cutting part. it can.

Then, a liquid material containing a large amount of soil particles is filled in the tail void portion C in a pressurized state, and a mud film is formed on the outer peripheral ground like the face, and the stratum B is formed by the pressing force through the mud film.
And the excavator 52 and the buried pipe do not come into direct contact with the stratum B to minimize the frictional force with the ground, thereby enabling propulsion with low thrust.

[Problems to be solved by the invention]

The muddy water injection method in the above conventional excavator is a method of installing a plurality of muddy water inlets 9 in front of the cutter unit 8 and injecting the muddy water a. It branches into each muddy water inlet 9 inside, and there is one mud feed system.

For this reason, when this method is used, at first glance, it appears that the muddy water a spreads over the entire cutting portion. However, in practice, the muddy water inlets 9 at a plurality of locations start to be sequentially clogged with excavated earth and sand during construction. Since the muddy water a comes out from the muddy water inlet 9 where the muddy water is most likely to come out, the muddy water inlet 9 that has begun to clog is closed as it is. And finally just one
It was the actual situation that only the muddy water inlet 9 of the location remained.

When water or the like is jetted experimentally on a shaft, water is discharged from all of the muddy water inlets 9 at a plurality of locations, but in the case of underground, particles of excavated sediment begin to clog in the muddy water inlet 9 inevitably. .

In this case, if the muddy water inlet 9 is located at one place, the supply of the muddy water a is stopped, so that the clogging of the muddy water inlet 9 can be immediately recognized, and the blockage can be recovered.

However, when there are a plurality of muddy water inlets 9, there is another muddy water inlet 9 that can be injected until all the muddy water inlets 9 are closed, and the muddy water supply is not stopped. I do not notice the clogging of 9. And finally the excavator 52
It is first determined that mud was fed to only one muddy water inlet 9 when was taken out of the arrival shaft.

In this case, the last remaining muddy water inlet 9 is not always a convenient place for excavating the cutter unit 8. It is unknown which mud inlet 9 remains at the end,
Is assumed to extend over the entire surface of the cutting part,
The situation was more unstable than in the case where the muddy water inlet 9 was assumed at one place in advance and the plan was made.

The present invention has been devised in order to solve the above-described problems, and ensures that muddy water can be reliably injected from all of the muddy water inlets at a plurality of locations without clogging the muddy water inlets at a plurality of locations with excavated earth and sand. The purpose is to inject into.

[Means for solving the problem]

The muddy pressurized propulsion method of the present invention is a muddy pressurized propulsion method in which muddy water is injected from a plurality of inlets provided on the front surface of a cutter part having a diameter larger than a shield cylinder toward the ground side in order to achieve the object. Wherein the excavation is promoted while feeding mud using a pump and a feed path that can be independently operated to each of the plurality of inlets.

[Action]

According to the muddy water pressure propulsion method of the present invention, muddy water is injected from a plurality of inlets into the cutting portion through a cutter portion having a diameter larger than that of the shield cylinder. Since the independent pump and feed pipe are used to supply mud to each inlet, the mud inlet is not left clogged with excavated earth and sand during excavation. Therefore, muddy water is properly and evenly injected into the entire surface of the cutting section, and the excavated earth and sand are quickly and reliably stirred and mixed. It is formed.

〔Example〕

Hereinafter, the features of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic side sectional view of an excavator according to an embodiment of the present invention.

In FIG. 1, the excavator 1 has a cylindrical shape as a whole,
A plurality of buried pipes 2 are sequentially connected behind the excavator 1.
In the shaft A for carrying the excavator 1 and the buried pipe 2,
A main push jack 3 is provided, and the rear end of the buried pipe 2 is pressed toward the excavator 1 by the main push jack 3, so that the excavator 1 and the buried pipe 2 are propelled in the stratum B.

A partition 5 is provided in the shield cylinder 4 of the excavator 1. On the front side of the partition wall 5, a rotating shaft 7 to which a rotating force is given by a driving device 6 such as a motor, and the rotating shaft 7 are connected,
A cutter 8 having an outer diameter larger than the outer diameter of the shield cylinder 4 of the excavator 1 is provided. Cutting blades 81 are provided at predetermined positions in the center and the outer periphery of the front surface of the cutter unit 8.

Further, a muddy water inlet 9 is provided at a plurality of positions on the front surface of the cutter portion 8, and in this embodiment, at four positions. 6 four hollow hollow portions 10 are pierced to the rear,
Has four mud pipes each via a rotary joint 11
12 are connected. Note that the tubular hollow portion 10 is
It is not always necessary to be a tubular inside, and it is sufficient that a feeding passage having an appropriate shape can be formed. In the rotary joint 11, the four mud feed pipes 12 are independently connected to the four tubular hollow portions 10, respectively, so that the muddy water inlet 9 of the cutter 8 and the mud feed pipe 12 correspond one to one. It has a structure.

The mud feeding pipe 12 is provided with four pumps 13 for pumping the muddy water a. The upstream side of the pump 13 is connected to a storage tank 14 that stores muddy water a.
Therefore, the mud feeding from each injection port can be independently injected for both the mud sending amount and the mud sending pressure.

The space surrounded by the partition wall 5, the cutter portion 8, and the shield tube 4 of the excavator 1 is an excavation room 15 in which the muddy water a and the excavated earth and sand are mixed and stirred.

In the excavation room 15, a scraper 16 is provided so as to project from the back of the cutter unit 8 in parallel with the axis of the rotary shaft 7. The scraper 16 scrapes off the earth and sand that tends to remain in the excavation chamber 15 and mixes the excavated earth and muddy water a.

Then, in the cutting section and the excavation chamber 15 on the front side of the cutter section 8, the liquid material formed by uniformly stirring and mixing the muddy water a and the excavated earth and sand forms a mud film on the ground side in front of the cutter section 8 and A tail void portion C is formed in a gap between the outside of the shield tube 4 and the formation B. A mud film is also formed on the tail void portion C.

In the lower part of the excavation chamber 15, a part of the partition wall 5 is opened, and a mud hole 17 is formed. A drain pipe 18 and a valve 19 are provided in communication with the drain port 17.
A sludge storage tank 20 is installed at the end of the sludge discharge side 19. Mud storage tank
At 20, a sludge pipe 21 is further extended, and a sludge unit 22 is continuously provided. 23 is a sludge pump.

 FIG. 2 shows a front view of the cutter unit 8.

As shown in the figure, a cutting blade 81 is radially disposed on the front surface of the cutter unit 8, and the outermost cutting blade 81 is located outside the shield tube 4, and the shield tube 4 and the formation B A tail void portion C is formed in the gap.

Then, at positions corresponding to the _four regions S ₁ , S ₂ , S ₃ , and S ₄ divided by concentric circles centered on the center of the cutter unit 8,
Each of the muddy water inlets 9 is provided. By arranging the muddy water inlet 9 in each area, the muddy water a is uniformly injected into the entire surface of the cut portion on the front surface of the cutter 8.

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

First, muddy water a is pumped through each mud feed pipe 12 by each pump 13. The pumped mud water a is evenly injected into the cut portion on the front surface of the cutter unit 8 from each muddy water inlet 9 through each tubular hollow portion 10 via the rotary joint 11.

The injected muddy water a fills the excavation chamber 15 and pressurizes the face with muddy water. Next, the rotary shaft 7 is rotated by the driving machine 6, and excavation is performed by the cutter unit 8 while continuing to inject the muddy water a from the muddy water inlet 9.

The muddy water inlet 9 is provided on the front surface of the cutter unit 8 with each region S ₁ , S ₂ , S ₃ , S
_The muddy water a is supplied to the vicinity of the cutting blade 81 of the cutter unit 8 and to the outer peripheral edge thereof. For this reason, the excavated earth and sand becomes easy to mix with the muddy water a, the clogging effect by the solid particles of the muddy water a and the excavated earth and sand is promoted, and the cutter portion 8 is pressed through the formed mud film, and the cutter portion 8 is pressed. Safety is achieved.

At this time, in the present embodiment, each muddy water inlet 9 is
Since each of them has an independent supply passage for the muddy water a and the pump 13, the muddy water inlet 9 is hardly clogged with excavated earth and sand.

If any of the muddy water inlets 9 is clogged,
Since the muddy water of the muddy water supply path of the muddy water inlet 9 is stopped,
The clogging can be known, and the recovery can be performed immediately.

Further, since the outer diameter of the cutter portion 8 is set to be larger than the outer diameter of the shield tube 4, a tail void portion C is formed between the outer periphery of the shield tube 4 and the buried pipe 2 and the stratum B after excavation. . The tail void portion C is filled with a liquid material having a high content of soil particles in which the excavated earth and sand and the muddy water a are sufficiently stirred and mixed with the excavation.

The liquid material having a high content of soil particles has a pressing force of the cutter unit 8,
For example, the same pressure as groundwater pressure + 0.2 kg / cm ²
A mud film is formed on the ground surface in the same way as the cutting part on the front side, and the pressing force suppresses the collapse of the ground at the tail void portion C, prevents loose earth pressure, and tightens the ground to the buried pipe etc. And the required propulsion of the excavator is reduced. Therefore, the excavator can be propelled with a small propulsion force, which is suitable for a long-distance propulsion method.

Excavated earth and mud after excavation pass through a drainage pipe 18 from a drainage outlet 17, pass through a valve 19, and are discharged into a mud storage tank 20.

Here, the valve 19 is opened and closed by a pressure difference between the pressure of the liquid material in the excavation chamber 15 and the atmospheric pressure in the excavator. Therefore, by appropriately adjusting the opening / closing operation pressure of the valve 19, it is possible to set the pressure of the liquid material for performing good excavation.

The muddy water and the like stored in the mud storage tank 20 are further discharged to a sludge discharging unit 22.
The sludge pipe 21 is carried out of the mine by slurry transportation by the suction force of the sludge pump 23.

〔The invention's effect〕

As described above, in the muddy water pressurized propulsion method of the present invention, muddy water is injected from a plurality of inlets on the front of the cutter unit. Use the road. Therefore, there is no possibility that the excavation continues while the muddy water inlet is clogged with earth and sand, etc., and the muddy water spreads over the entire face, and the muddy water and the excavated sediment are evenly mixed and mixed. A stable mud film can be formed on the front surface and the outer peripheral edge of the portion. In addition, the excavation chamber becomes a good liquid material, and the fluctuation of the face pressure becomes minute, so that the mud can be discharged stably. This allows
Inability to excavate due to attempted mud feeding and various troubles can be avoided, and stable propulsion work can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view showing a structure of an excavator in an embodiment of the present invention, FIG. 2 is a front view of a cutter portion of the excavator,
FIG. 3 is a schematic side sectional view of a conventional excavator. 1: excavator, 2: buried pipe 3: main push jack, 4: shield cylinder 5: bulkhead, 6: drive machine 7: rotary shaft, 8: cutter section 9: muddy water inlet, 10: tubular hollow section 11: rotary Joint 12: Mud pipe, 13: Pump 14: Storage tank, 15: Drilling room 16: Scraper, 17: Drain outlet 18: Drain pipe, 19: Valve 20: Mud storage tank, 21: Drain pipe 22: hydraulic unit, 23: Hydraulic pumps 50: Okudorokan, 51: hollow portion 52: excavator, 81: cutting edge A: pit, B: strata C: Teruboido unit, a: mud S _1, S _2, S _3, S _4: area

Claims (1)

(57) [Claims] In a muddy water pressure propulsion method for injecting muddy water from a plurality of inlets provided on a front surface of a cutter part having a diameter larger than that of a shield tube toward a ground side, each of the plurality of inlets is independently provided. A muddy water pressurized propulsion method characterized in that excavation and propulsion are performed while feeding mud using a pump and a feed path capable of performing an operation.