JPH0522800B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an excavator used in a mud water pressurization type shield construction method and propulsion construction method.

[Conventional technology]

When constructing a tunnel in the ground, various construction methods are used, one of which is the stabilized solution construction method.

The stabilized liquid method began with the drilling of oil wells in 1914.
Applied to underground continuous wall construction method, reverse pile construction method, etc.
The scope of its application has expanded to include the muddy water pressurized shield method and muddy water pressurized propulsion method, which involve digging horizontal underground holes. The basis of this is, for example, in the literature ``Theory and Practice of Underground Continuous Wall Construction Method'' (by Kiyomitsu Fujii and three other authors, published by Sankaido, March 1975), page 3, lines 3 to 6, ``Shimizu and digging waste.'' The well was filled with muddy water, which is a mixture of the following: As the well deepened, it was recognized that this muddy water had the ability to hold back groundwater and gases, as well as safely support the fragile geological formations. is expressed in

Therefore, the muddy water pressurized excavation method described above injects muddy water (a mixture of plugging material, thickener and water) into the excavation chamber during excavation, dissolves the excavated earth and sand in the muddy water, turns the inside of the excavation chamber into a liquid, and then A mud film is formed on the face surface due to the clogging effect of solid particles of mud water and excavated soil (drill waste), which usually increases groundwater pressure +
The mud pressure of about 0.2Kg/ ^cm2 suppresses and stabilizes the groundwater and face collapse through the mud film.

The excavation structure of conventional mud water pressurized excavators mostly uses a rotary excavation method, and there are differences in the support methods for the cutter head, such as a center shaft method and a peripheral support method. It was common to excavate the earth and sand at the face by rotating the cutta ace (face plate) or cutta spoke with the center of the shaft as the center point of the rotation axis.

[Problem that the invention seeks to solve]

However, conventional tunneling machines had the following problems.

(i) The excavation cross section is limited to a circular shape because the excavation machine excavates the earth and sand at the face by rotating the Katsutaface etc. with the center of the excavator as the center point of the rotation axis. However, in hybrid sewage pipes with subways, underground passages, telecommunications lines, power lines, optical communication networks, etc., rectangular (box-shaped) or horseshoe-shaped (arch culvert) cross sections are more efficient and economical. This is a well-known fact, and it is clear that there will be a social demand for these non-circular cross sections in the future.However, with conventional mud water pressurized excavators, the excavation cross section is limited to a circular shape, and there are no rectangular or horseshoe-shaped cross sections. Excavation was either impossible or extremely difficult.

(ii) Since the earth and sand on the face is excavated by rotating the cutter ace, etc., the whole section is excavated, and the mud film on the entire surface of the face is scraped off at once, making the face unstable.

(iii) Full-section excavation requires a large amount of torque, and the size of the drive machine also increases accordingly, making it easy to remove the equipment inside the excavator if you encounter a bedrock layer or giant boulder layer that cannot be excavated during excavation. It is often difficult to change to manual digging,
If the soil layer returns to a level where it can be excavated, it is almost impossible to install mechanical excavation equipment again during excavation, and the only way to deal with this is to dig a shaft from the ground and use an excavator to dig it up. If this is not possible, the only option is to pick up and retrieve the material from the reaching side by hand digging with a diameter larger than the outside diameter of the excavator, and if the soil quality changes within the excavation section, it is difficult to respond appropriately.

(iv) When excavating a gravel layer or cobblestone layer, or when excavating over a long distance (more than 300 to 1000 m) as in the shield method, the cutter bits naturally wear out. At this time, when replacing the cutting head during excavation, if the diameter is large (2000 mm or more), it is possible to install a work entrance (manhole) in advance for replacement, but since the work is in front of the face, the face may collapse. If the diameter is less than Ф1500mm, it will be very difficult to replace the cutout pit.
This makes it difficult to reduce the diameter.

(v) In the case of full-section excavation, it is often observed at the site that when the cutting stub embeds itself in the ground at the face during excavation, the reaction force tends to cause the excavator to rotate, that is, the rolling phenomenon of the excavator occurs. However, when the excavator rolls, the equipment and equipment inside the excavator will rotate and move, making the operation and accuracy of the excavator unstable and inhibiting normal excavation.

Although the present invention is a mud water pressurization type, it is possible to excavate not only circular cross sections but also arbitrary cross sections such as rectangular and horseshoe shapes.The required torque of the cutter is also very small, and the cutter drive device can therefore be made smaller. The purpose of the present invention is to provide an excavator that can be used to make small diameter tunnels.

[Means and actions for solving problems]

The present invention is a mud water pressurizing excavation machine used in shield construction method and propulsion construction method, in which mud water and excavated soil are stirred and dissolved at a face, and the excavation chamber is filled with a highly concentrated liquid material containing a high filler material. In the above-mentioned mud water pressurizing excavation machine, an outer tube is pivotally supported so as to be freely movable about a substantially central part of the partition wall of the mud water pressurizing excavation machine, a rotating shaft is rotatably inserted into the outer tube, and a rotary shaft is provided at one end of the rotating shaft. A drive machine that provides rotational force to this rotating shaft, and a drive machine that is attached to the other end of the rotating shaft and is 1/5 of the diameter of the excavator.
A cutter having an outer diameter of approximately 3/5, a swing operating device provided on the drive machine side of the outer tube to freely move the cutter in any direction, and a swing operation device provided on the drive machine side of the outer tube for drilling. a guide frame having a shape corresponding to the cross-sectional shape of the cutter and limiting the range of movement of the cutter; and a telescopic blocking device installed in a liquid-tight manner between the outer tube, the outer periphery, and the partition wall. It is characterized by having been established.

With this configuration, the inflow of groundwater and earth and sand into the face is prevented by the blocking device, and the cutter is used to excavate along an arbitrary preset cross section using the floating operation device. In addition to making it possible to excavate any cross section such as a rectangular shape or a horseshoe shape, the excavation is performed while maintaining the stability of the face without scraping off the mud film formed on the face all at once.

In addition, the above-mentioned cutter has a short distance between the rotation axis of the cutter and the cutting bit, so the cutter torque can be small, the drive mechanism can be small-scale, and the equipment inside the excavator can be easily assembled and disassembled, making it easier to manually drill the cutting edge. Mud water pressurized excavation can be easily converted to each other, and changes in the soil layer during excavation can be appropriately responded to.
The cutter portion can be replaced safely and easily, and diameter reduction can be promoted.

〔Example〕

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

In FIGS. 1 and 2, 1 indicates a generally cylindrical excavator, 50 indicates a buried pipe (segment or propulsion pipe) provided at the rear of the excavator 1,
An excavation device 2 is freely movable inside the excavation machine 1.

The excavation device 2 includes a rotating shaft 22 to which rotational force is applied by a drive device 21, a cutter 23 connected to the rotating shaft 22 and having an outer diameter of about 1/5 to 3/5 of the diameter of the excavating device 1, and a rotating It is composed of an outer tube 24 that covers the outer periphery of the shaft 22 along the axial direction.

Further, a spherical part 25 is provided in the middle part of the outer tube 24, and this spherical part 25 is connected to the shield tube 1 of the excavator 1.
It is pivotally supported by a pivot support 12 that is composed of a pair of support columns 12a projecting inward from the support column 1 and seats 12b attached to the tips of these columns. In addition, support column 1
2a has a hook provided at its base end that is slidably engaged with grooves 4 of a pair of slide rails 3 provided in the shield tube 11 of the excavator 1 along the axial direction of the excavator 1. By fitting them together, they can be attached so as to be movable in the axial direction of the excavator 1.

Further, an annular partition wall 13 is provided along the inner circumference of the shield tube 11, and between this partition wall 13 and the outer tube 24, one end thereof is fixed to the outer circumference of the outer tube 24 by a cylindrical body 14a, and the other end is fixed to the outer circumference of the outer tube 24. A sleeve-shaped blocking device 14 made of an elastic and expandable material is fixed to the partition wall 13 with a fixing member 13a such as a bolt via an annular presser plate 13b. The shutoff device 14 is constructed of a single layer or multiple layers of, for example, a flexible plate-shaped reinforced rubber or resin. In order to increase the strength of the above-mentioned reinforced rubber or resin, steel wire, synthetic fiber, etc. may be used as the core material.

Further, as shown in FIG. 3, the rotating shaft 22 is supported with respect to the outer tube 24 by a seal 26 and a bearing 27 that prevent muddy water from entering.

Further, one or more muddy water inlets 28 are formed on the cutting surface of the tip of the cutter 23, and the muddy water inlets 28 are formed in the rotary shaft 22 along its central axis from the muddy water inlet 28 to the drive machine 21 side of the rotary shaft 22. to,
A tubular hollow portion 29 is bored, and a communication hole 30 is formed from the end of the hollow portion 29 on the driver 21 side at right angles to the axial direction, as shown in FIG.

A large-diameter mud feeding pipe connecting portion 31 is provided at a tube location corresponding to the communication hole 30 of the outer tube 24, and a mud feeding pipe 32 is attached to this mud feeding pipe connecting portion 31.

On both sides of the mud feeding pipe connecting portion 31 in the axial direction, there are seals (not shown) to prevent muddy water from leaking into the gap between the rotating shaft 22 and the mud feeding pipe connecting portion 31 and bearings (not shown) to smooth rotation. ) is installed.

As shown in FIG. 2, a mud draining port 16 is formed in the partition wall 13, and a mud draining pipe 17 is connected to the mud draining port 16.
and a valve 18 are provided, and a mud storage tank 19 is installed at the end of the valve 18 on the mud removal side.

Moreover, between the pivot portion 12 and the drive machine 21,
As shown in FIG. 6, three operating jacks 15a
However, the base is pivotally supported by an annular body 15b having a diameter slightly smaller than the inner diameter of the propulsion device 1, and is attached so as to protrude inward to constitute the floating operating device 15 as a whole. Outer tube 2
4 should be supported from three sides. Annular body 15b
is provided with a hook portion 15c as shown in FIG.
It is slidably engaged with the grooves 4 of the pair of slide rails 3 described above.

Further, between the pivot portion 12 and the floating operation device 15, an annular portion 20b into which the outer tube 24 is inserted, and this annular portion 20b are slidably fixed to the pair of slide rails 3. A guide frame 20 is provided, which includes a pair of supports 20a.

Further, a dissolving stirring plate 33 as shown in FIG. 5 is attached to the vicinity of the cutter 23 of the rotating shaft 22 so that the excavated earth and sand at the face can be rapidly dissolved in the mud feeding water.

Note that the mud water inlet 28 for mud feeding may be installed in the partition wall 13, etc., but in order to quickly form a mud film on the face and to reduce the excavation torque during excavation, etc.
It is desirable to install it on the cutting surface of the tip of the cutter 23.

As shown in FIG. 7, the shutoff device 14 may be one in which air, water, oil or the like is injected into a bag-like body having an elastic inner cavity to inflate it and bring it into close contact with the outer tube 24; As shown in FIG. 8, a block of highly elastic rubber, resin, or the like may be used.

In the embodiment, two support columns 12b of the pivot portion 12 form a pair, but there may be three or more.

Moreover, instead of the catch seat 12b and the spherical part 25, a support shaft 34 having a gimbal structure that can be rotated horizontally and vertically as shown in FIGS. 7 to 9 is used, and the outer tube 24 You can also attach it.

Further, in the above embodiment, the groove 4 was provided on the slide rail 3 side, but as shown in FIG. 11
A groove 4 may be provided at the side end.

Next, the operation of the excavator according to the present invention will be explained.

First, from the mud feeding pipe 32 to the communication hole 3 of the rotating shaft 22.
0. Mud water is injected into the excavation chamber formed between the face and the partition wall 13 through the hollow part 29 and the mud water inlet 28, and the face is pressurized with the mud.

Next, the rotary shaft 22 is rotated by the driving machine 21, and the cutter 23 performs excavation while injecting muddy water into the excavation chamber from the muddy water inlet 28. At this time, the communication hole 30 provided in the rotating shaft 22 and the outer tube 2
Due to the action of the large-diameter mud feeding pipe connecting portion 31 provided at 4, muddy water can be injected even while the rotating shaft 22 is rotating. The mud feeding water is supplied near the face surface, and the excavated earth and sand is easily dissolved in the mud feeding water, and the clogging effect by the solid particles of the mud feeding water and the excavated soil is promoted, and the face is pressed through the formed mud film. This stabilizes the face.

At this time, by expanding and contracting the operating jack 15a using hydraulic pressure or air pressure, the cutter 23 can be freely moved horizontally, vertically, and circumferentially to excavate any cross section of the face.
That is, in addition to the circular cross section shown in FIG. 11, the rectangular (box-shaped) cross section shown in FIG.
It is possible to excavate any cross section such as the horseshoe (arch culvert) cross section shown in the figure. Although the mud drain port 16 is provided diagonally below the cutoff device 14 in FIG. 11, it may be provided on the side of the cutoff device 14 as shown in FIGS. 12 and 13.

The movement range of the cutter 23 is controlled by the guide frame 20, which has a shape that corresponds to the shape of the cross section to be excavated, and by performing excavation along the set cross section, over-excavation can be prevented.

The excavated soil and mud after excavation pass through the mud drainage pipe 17 from the mud drainage port 16, and are transferred to the mud storage tank 19 by opening and closing the valve 18 based on the differential pressure between the mud water pressure at the face and the atmospheric pressure inside the excavator 1. The slurry is removed, transported through pipes, and transported outside the mine.

Further, the shield tube 11 is provided with a slide rail 3 in which a groove 4 is formed along the axial direction of the excavator 1, and the shield tube 11 of the support column 12a, the support body 20a, and the operating jack 15a is provided in the groove 4. Since the hooks provided at the side ends are slidably engaged with each other, the cutter 23 can be slid back and forth in the event of trouble due to changes in the soil layer during excavation, and the degree of excavation can be adjusted to the appropriate level. It becomes possible to respond.

In the present invention, the outer diameter of the cutter 23 is approximately one-fifth to one-third of the diameter of the excavator 1, and the length of the moment arm between the rotating shaft 22 of the cutter 23 and the cutting surface is short. Therefore, compared to the conventional mud water pressurizing excavator, the cutting torque is small, and the drive unit 21 is compact, making disassembly and assembly easy.

The bulkhead 13 is also attached with fasteners 1 such as bolts from the inside of the excavator.
3a, it has a structure that can be easily assembled and disassembled, so if you encounter a bedrock layer or a giant boulder layer due to changes in the soil layer during excavation, you can easily remove them and immediately change to manual excavation, making it possible to excavate again. If the soil layer returns to a certain level, the bulkhead 13 and cutter 23 are installed again and mechanical excavation is performed.

Moreover, when long-distance excavation as in the shield method or excavation of a gravel layer, the cutters 23 naturally wear out. Therefore, it is necessary to replace the cutter 23, but since the cutter 23 is compact as described above, replacement is very easy. When replacing the cutter, stabilize the face using a chemical injector or the like, pull the cutter 23 into the excavator through the opening of the bulkhead 13, and immediately replace it with a spare cutter, or replace the bit etc. on the ground.

〔Effect of the invention〕

As described above, according to the present invention, the following effects can be obtained.

(i) A blocking device was installed to prevent the inflow of groundwater and earth and sand into the face, and the rotating shaft to which the cutter was attached was able to move freely around the center of the excavator. , the excavation cross section is not limited to a circular cross section, but also a rectangular (box shape)
It is possible to excavate any cross-section, such as a cross-section or a horseshoe-shaped (arch culvert) cross-section. Therefore, it is possible to easily excavate a rectangular cross-section or a horseshoe-shaped cross-section, which is efficient and economical, in hybrid sewage pipes, etc. where subways, underground passages, telecommunication lines, power lines, optical communication networks, etc. are installed. .

(ii) The mud film on the entire surface of the face is not scraped off all at once, and most of the face is covered with the mud film even during excavation work, making the face more stable.

(iii) Since the distance between the rotating shaft and the cutting part of the cutter is short, the cutting torque is small, and the drive relationship becomes compact, making it easier to reduce the diameter.

(iv) If you encounter a bedrock layer or a huge boulder layer that cannot be excavated during excavation, the drive mechanism is compact, so you can easily remove the equipment inside the excavator and switch to manual excavation, and the excavation will continue smoothly. If you return to a viable soil layer, it is easy to reinstall mechanical excavation equipment during excavation.

(v) Workability is good because a wide working space can be secured, and the small diameter makes it easy to replace the cutters when they become worn out when digging in hard soil or gravel layers or when digging long distances. It can effectively cope with long-distance excavation and gravel layers, and can promote downsizing.

(vi) As the excavation distance increases, the number of curved construction points increases, and extra excavation parts are required when performing curved construction.However, in the case of the excavation machine of the present invention, the shape of the guide frame is changed and the rotation axis is operated. It is also easy to control the over-digging part.

(vii) Unlike the conventional mud water pressurization propulsion, full-section excavation is not performed, and during excavation, the rotational axis of the cutter and the excavator are not on the same axis but are shifted, so the reaction force when the cutter excavates is caused by the excavator. It is not transmitted as a rolling force, and therefore rolling is less likely to occur.

[Brief explanation of drawings]

1 and 2 are a sectional view and a partially cutaway perspective view of an excavator according to the present invention, FIG. 3 is an enlarged sectional view of the main part of FIG. 1, and FIG. 4 is a sectional view taken along the line shown in FIG. 1. ,
Fig. 5 is a sectional view taken along the line of Fig. 1, Fig. 6 is a front view of the operating jack, Figs. 7 and 8, FIG. 10 is a sectional view showing another embodiment of the slide rail, and FIGS. 11 to 13 are front views showing cut sections of different shapes. 1: Excavation machine, 2: Excavation equipment, 3: Slide rail, 4: Concave groove, 11: Shield cylinder, 12: Pivot part, 12a: Support column, 12b: Receiver, 13: Partition wall, 13a: Fixture, 13b : Holder plate, 14:
Shutoff device, 14a: cylindrical body, 15: floating operation device, 15a: operation jack, 15b: annular body, 1
5c: Hook part, 16: Sludge draining port, 17: Sludge draining pipe, 1
8: valve, 19: mud storage tank, 20: guide frame, 20a: support body, 20b: annular part, 21: drive machine, 22: rotating shaft, 23: cutter, 24: outer tube, 25: spherical part, 26 : Seal, 27: Bearing, 28: Mud water inlet, 29: Hollow part, 30:
Communication hole, 31: Sludge pipe connection part, 32: Sludge pipe, 3
3: Dissolution stirring plate, 34: Support shaft, 50: Buried pipe.

Claims (1)

[Claims] 1 In the mud water pressurizing excavation machine used in the shield method and propulsion method, which excavates by stirring and dissolving mud water and excavated soil at the face and filling the excavation chamber with a highly concentrated liquid material containing a high content of plugging material, the above-mentioned method is used. An outer tube pivotably supported approximately at the center of the bulkhead of the mud water pressurizing excavator, a rotating shaft rotatably inserted through the outer tube, and a rotary shaft provided at one end of the rotating shaft. a drive device that applies rotational force to the rotary shaft, a cutter that is attached to the other end of the rotating shaft and has an outer diameter of about 1/5 to 3/5 of the diameter of the excavator, and a cutter that is installed on the drive device side of the outer tube. a swing operating device for freely moving the cutter in any direction, and a guide frame provided on the driving machine side of the outer tube and having a shape according to the shape of the cross section to be excavated and limiting the movement range of the cutter. A mud water pressurizing excavator, characterized in that a retractable shutoff device is provided between the outer periphery of the outer tube and the partition wall portion in a fluid-tight manner.