JPH01174794A - Front foundation improvement method and device for shield excavator - Google Patents

Abstract

PURPOSE:To prevent any accident due to a collapse of ground from occurring by connecting a filling pipe connected to a filling short pipe, to a cap without removing this cap, advancing it to the outside of a machine from a cap mounting hole and filling a ground improver therein. CONSTITUTION:A cap 5 with a cutting blade is attached to a forward port 4 installed in a front end 2 of a shield excavator 1 and/or a side wall surface 3 proximate to it, and when there is a fear of collapse of ground 9 during excavation of a tunnel 7, a filling pipe 300 connected with a filling shor pipe 30 is connected to the cap 5 via a pressing device, and it is advanced into the ground 9 in a state as it is. Then, any of a flash setting filler, a retard setting filler, and grout such as cement milk or the like or a ground improver made up of combining these elements together properly is impregnated from a clearance where a ring elastic body 35 installed in recess 36 at the side of the filling short pipe 30 is opened wide, and thus shield excavation advance takes place as improving the ground 9.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The inventions of this application all relate to a method and an apparatus for improving the ground in front of a shield excavator during tunnel excavation by the shield excavator.

(Conventional technology) When forming a tunnel with a shield trencher.

Closed type shield excavators are often used.

In such cases, in order to balance the surrounding earth pressure, the space in front of the shield excavator and the surrounding ground is filled with muddy water, mud, mud, or pressurized air. but,
Even if you do this, the pressure relationship will be disrupted in places with a lot of spring water, ground with many faults, or even soft ground, and a sudden change in the strata in the ground due to a pressure control error will cause the ground to collapse, resulting in an accident. I had something to do.

Therefore, a method was developed in which soil improvement material is injected in front of the shield excavator before excavation proceeds.

It has been filed as Utility Model Application No. 61-35997.

However, the method using this device.

■ The polling work and the injection pipe advancement work are separate processes.
The work is complicated, and the equipment is also complicated and expensive.

■ When advancing the polling machine or injection tube outside the machine through the through hole (3) drilled on the cutter surface (front end surface), it is necessary to remove the cap fitted to the second through hole (3).
At that time, a large amount of dirt, mud, spring water, etc. can instantly enter the cabin, causing the ground to collapse and creating a dangerous situation.

■ A gap is created between the poling hole created by water drilling and the injection pipe, and the pipe wall is not in close contact with each other, making it impossible to inject into the desired location, or the injection pressure decreases, making it impossible to inject the chemical solution deeply. is washed away along the pipe wall and is wasted.

There were drawbacks such as.

For this reason, the inventor of the present application ■ Perform polling work and injection pipe advancement work at the same time.

■Remove the cap only once.

■ Prevent gaps between the injection pipe wall and the ground.

For this purpose, a patent application No. 1983-2739905 was filed. However, this is very ■ I have to remove the cap even once.

At this time, mud, mud, and spring water may collapse, causing accidents.

■ Removing and attaching the cap is troublesome.

There was a drawback.

(Problems to be Solved) In the present invention, in order to solve the above-mentioned drawbacks, the short injection pipe is directly connected to the cap as a stopper without removing it, and the injection pipe is removed from the machine through the hole where the cap is attached. The problem to be solved is to make it possible to advance and inject soil improvement material.

(Means for Solving the Problem) In the present invention, an injection pipe outlet is bored on the tip end face of a shield excavator or a side wall face near the end face, a cap with an excavator blade is attached thereto, and a tunnel is excavated. The injection pipe is freely connected to the cap with the excavation blade at any time during the process, and with the cap still attached to the tip, the injection pipe is advanced into the ground in front of the shield excavator to perform instant setting injection or slow setting injection. The above-mentioned problem was solved by performing shield excavation while improving the ground in front by injecting a ground improvement injection material made of either lumber or grout such as cement milk, or a suitable combination of these.

As a more specific solution, there is a ground improvement method in front of a shield excavator with the above configuration, and an injection pipe entrance is drilled in the front of the machine, into which a cap with an excavator blade can only advance outward. A forward ground improvement device during shield excavation, consisting of a shield excavator installed in a watertight manner in
The problem was solved by developing the above-mentioned shield excavator itself and the above-mentioned cap with an excavator blade.

(Example 1) Embodiments of each invention of the present application will be described with reference to the drawings.

Figure 1 shows how a tunnel (7) is formed by digging a horizontal hole (8) with a substantially circular cross section underground using a shield excavator (1), and installing segments (6) there. In particular, it shows how the injection pipe is advanced from the front end face of the shield excavator (1) into the front ground (9) in order to inject the injection material into the front ground (9). Since the shield excavator (1) and the construction method using the same are already known, the explanation thereof will be omitted, and nine features of the present invention will be explained in detail.

A tunnel (6) is constructed using a shield excavator (1) in a known manner.
), if the ground in front (9) is soft or has a lot of muddy water, sludge, or spring water, and there is a risk of ground collapse if the excavation continues, - Interrupt excavation and inject soil improvement material. Before explaining the injection method, the features of the shield excavator according to the present invention, the injection pipe, and the cap will first be explained.

First of all, the shield excavator (1) according to the third invention of the present application is equipped with all the mechanisms of the known shield excavator, and in addition, a new entrance ( 4) is bored, and a cap with a digging blade (5) is fitted therein in a watertight manner. There are various fitting means for the cap with the digging blade, but in this first embodiment, the one shown in FIG. 3 will be explained.

The cap with a digging blade (5) in FIG. 3 has a digging blade (501) at its tip, followed by a main body (502).
).

Furthermore, there is a connecting part (503). The connecting part (503) has a tool engaging part (SOS) on its rear end surface, and is screwed into the entrance (4) with the digging blade facing outward. As a screwing means, a method is used in which a male thread is carved on the outer periphery of the main body and a matching female thread is carved on the inner periphery of the exit opening (4).

The tool holding part (505) is a cap (5) with a digging blade.
This is for engaging a tool when screwing the screw into the exit port (4), but this is not necessary and the location where it is formed is not specified here.

A short injection pipe is connected to such a cap (5) with an excavation blade, and while a rotational force is applied by a propulsion device, the cap (5) with the excavation blade is advanced into the ground (9) in front while the two are connected.
The injection short tube will now be explained, and in this example, the one shown in FIGS. 7 and 8 will be explained.

As shown in Fig. 7, the injection short pipe (to) has an outer diameter that is the same as the outer diameter of the cap main body (502), and a grout hole (4) is provided on the outer wall thereof. A male screw 03 is provided which is screwed into the female screw (301).

A female thread 07) that connects with the male thread of the connection part (503) of the cap is formed on the distal end surface of the short injection tube (toward), and a swivel or another injection tube is formed on the opposite rear end surface. A male thread is formed to connect the short tubes.

A guide hole (b) is opened in this rear end surface.

The guide hole extends to the appropriate position of the injection short pipe.

Inlet ports C3I to C39 are radially opened in the peripheral wall of the short injection tube in communication with this. The inlet (31) communicates with a concave chamber 2 having a spout opening in the outer circumferential wall of the short inlet tube, and an annular elastic body (to) is inserted into the concave chamber so as to cover the inlet 69. As shown in Figure 1, the outer periphery of the part of the recess into which the annular elastic body (c) is inserted is the same as the outer periphery of other parts of the injection tube (to) even when the annular elastic body is attached. so that it has the same diameter as

The depth of the recessed chamber which is attached and presses the annular elastic body, the size of the annular elastic body (to), and the size of the jet nozzle (2) are arbitrary and determined as appropriate.

This is fine when one injection short tube is sufficient, but if this does not allow injection to the desired depth, a second and third injection short tube must be connected. This second. The third injection short tube (30") has almost the same structure as the first injection short tube shown in Figure 7, but the guide hole passes through the tip surface (upper side in Figure 7). This is clearly seen in Figure 10.

Injection pipe (aOO) that connects the cap with digging blade (5), the first injection short pipe (to), and the second injection short pipe (30")
As is clear from Fig. 10, the outer circumferential wall has a male thread that engages with the female thread carved on the inner circumferential wall of the outlet (4), and a guide hole ( B)
The tip of each injection short tube (to) is occluded (30°
) are perforated to communicate with each other.

Next, a method and apparatus for injecting the excavation/injection pipe (300) into the forward ground α through the entrance (4) will be explained.

The dotted line in the upper left of Figure 1 is the excavation and injection pipe (3
00), it is introduced into the front ground (9), and subsequently, the ground improvement material is injected. To get to this state.

First, the suppression device is placed at a predetermined position in the tunnel (7) formed by assembling and connecting the segments (6) in the shield excavator (1) or in the horizontal hole (8) excavated by the shield excavator (1) via the rail α0. Carry and secure.

This suppression device has a base (13) equipped with wheels for running on rails and a frame 0, and an injection tube pushing device is pivotally supported on this frame a3 so as to be able to adjust the angle. And beyond that is the injection tube holding cylinder C17
) is extended, and a cover-integrated α mark is provided on a part of the upper part of the holding cylinder for inserting and removing the injection short pipe (to).

This cover-integrated α barrel can rotate or slide relative to the holding cylinder (171) so that the short injection tube can be taken in and out when necessary.On the other hand, a worm gear and a ratchet wheel u3 are attached to the frame (13) on the shaft I. This ratchet wheel q9 is integrally fixed to the motor (19 and holding cylinder d7) described above.

A handle is attached to the worm gear (2), and by rotating it, the ratchet wheel 119
is rotated, and the tartar α9 and holding cylinder αη are rotated to an arbitrary angle. The motor mata 9 is an electric motor or a fluid pressure motor (hydraulic,
pneumatic motor) etc. Either reduce the rotational force of the motor and transmit it to the male screw C (3) carved on the outer periphery of the short injection pipe (to) to rotate it, or
A hydraulic motor that rotates the rear end is connected to rotate the injection short pipe (to) and the cap with excavation blade (5). In addition, a press-in device is provided for pumping soil improvement material into the injection pipe. At the tip of this press-in device, a swivel is attached to connect to the end of the injection pipe, pumps (Ft, (P') are used to apply pressure, and a mixing device is used to mix the injection liquid and materials. etc. are provided.

These press-fitting devices are well known and there is nothing new about them, so the explanation will end here.

Next, the construction method of the first invention of the present application will be explained using these devices.

While the shield excavator (1) is excavating a side hole (8), if the ground in front (9) is poor and there is a danger of collapse, etc., the excavation is temporarily stopped and the pressing device is placed in a predetermined position. In this case, it is convenient to have a rail (IG) installed, but this is not necessary.Once the suppressor is in place.

Rotate the handle (to) and rotate the wheel (II).

The motor haze and holding cylinder t1η fixed to it are connected to the front end face (2) of the shield excavator (1) and the side peripheral wall near it (
3) to match the angle of the exit opening (4) drilled in the hole (4). Next, a cover integrated 18 provided on a part of the holding cylinder tL7)
Open the injection short pipe (to) and store the short injection pipe (to) in the holding tube 1η, and insert its tip into the connection part (503) of the cap with excavation blade (5) fitted into the outlet (4). Link.

When the connection is completed, drive the motor (1!19) and apply its rotational force to the injection pipe (300) where the cap with digging blade (5) and the injection short pipe (to) are connected.
4) The inner circumferential wall has a female thread carved into it that engages with a male thread carved on the outer periphery of the injection pipe (300), so as the injection pipe (aOO) rotates, the injection pipe (aOO) will be exposed to the outside of the machine and even to the ground in front of it ( 9)
Advance inside. In this case, in front of the injection tube (300).

Since the excavating blade (501) is attached, the push force of the motor alone is enough to penetrate the ground even without water, but in some cases, water may be ejected from the tip of the injection pipe (300) to dig into the ground. Drilling with water while breaking is also possible. Injection tube (
300) into the ground in front is shallow, connect several short injection pipes (30°) in the axial direction,
Prepare the injection tube (300) by lengthening it using the method described above.
Advance to the front ground (9) deeper than the arm in figure 0. Once the desired depth is reached, the soil improvement material may be injected immediately, but leave it in the same state as it has been advanced, and insert the injection pipe (aOO) into each of the front ground from another entrance in the same way as before. After advancing in the direction, attach a swivel (S) to each rear end.
) can be connected to inject ground improvement material all at once. The injection method for this improving material is the same as the conventional method, and various well-known methods such as 1 shot, 1.5 shot, 2 shot, etc. can be adopted.

The injection of the ground improvement material may be carried out once after the injection pipe (300) reaches the desired depth;
00) may be performed continuously while moving backward, or several times by temporarily stopping at an appropriate place. Injection tube (300
) can be retracted by reversing the motor exposure or by changing the gear combination of the reduction gear.
This is possible by rotating 0) in the opposite direction. At this time, once one injection short tube (30) is completely stored in the holding tube The short injection pipe (to) is removed one by one by retreating it into the holding cylinder 1η, and finally the cap with excavation blade (5) is screwed back into the inlet (4). Finish the injection work.

When the injection work is completed, excavation is resumed using the shield excavator (1), and once the ground is in poor condition, the above-mentioned injection work is performed again. In this way, a safe and strong tunnel can be formed while preventing accidents caused by ground collapse.

Furthermore, if necessary, an inlet (4°) is formed in the segment, and caps with digging blades (5) similar to those attached to the front end are attached thereto, and injected in the same way as before. A short pipe can be connected to it to form an injection pipe, and a swivel (8) can be connected to the end of the injection pipe to inject soil improvement material or backfilling material. A stable and strong tunnel that will not collapse can be formed.

(Embodiment 2) Another embodiment of the first invention of the present application will be described using FIG. 1, FIG. 4, FIG. 6, FIG. 9, FIG. 11, and FIG. 12.

Cap with digging blade used in this example (51)
As shown in FIG.
503') Furthermore, there is a tool retaining part (505°) on the end face.
Although it is basically similar to that of Example 1 in that it has .

There are no male threads on the outer periphery of the main body and it is smooth. However, there are 506 stopper retaining parts formed somewhere.

On the other hand, an entry opening (41) is formed in the front end face (2) of the shield excavator (1) and the side peripheral wall (3) near the front end face (2).
The inner periphery is generally smooth, and a part of the inner periphery has a groove in which the packing (101) is housed.

On the other hand, the injection short pipe 5 (H) to be connected to the cap with a digging blade (5) has a smooth outer periphery as shown in Fig. A female threaded portion (62) to which a short injection pipe or swivel is connected is formed.A cap with a digging blade (51) is provided on the inner periphery of the recessed portion.
) is provided with a female thread (57) that engages with the male thread provided on the connecting part (503°), and the rear end has a female thread to which the next injection short pipe 6G or swivel should be connected. It is engraved.

The short injection tube 6G in this example is a type of injection tube called a double tube (
500), and two independent passages are provided in the pipe so that two types of soil improvement chemicals, improvement materials, water, etc. can be sent at the same time. Therefore, the outer pipe on the injection short pipe side (5
1) has an inner tube (6) in a continuous cavity (54) consisting of a large diameter part (62), a medium diameter part (63), and a small diameter part (64).
1) is provided with its tip connected to the small diameter portion (64). Specifically, the tip (upper part in the figure) of the inner tube (61) has a small diameter part (64) and a medium diameter part (63), as is clear from FIG.
) is fixed with screws to the stepped part. and the tip of the small diameter part (
7) is closed, the inner tube (61) and the small diameter portion (64) form one passageway, ie, the B liquid groove hole (b) whose tip is closed, and the inner tube ( A liquid groove hole (a) is formed by a space defined by the outer circumferential wall of 61) and the inner walls of the large diameter portion (62) and the medium diameter portion (63).

A liquid inlet (60) communicating with this human fluid guide hole (a) and a liquid B inlet (59) communicating with the liquid B groove (b) are opened so as to communicate with the outside of the pipe. ing.

Both the A liquid inlet (60) and the B liquid inlet (59) communicate with the concave chamber (56), where the two liquids are mixed and ejected out of the tube via the ejection port (58). become.

A rubber-like elastic body (55) is inserted into the concave chamber (56) and acts as a check valve to prevent dirt, mud, mud, etc. from entering the pipe.

The above injection short pipe 5■ can be called the first injection short pipe side that should be attached to the cap with excavator blade (5'), but if it is too short as an injection pipe and cannot be used to inject to the desired depth. The second tube has a double tube structure. It is necessary to add a third injection short tube (50'). This second.
The third injection short pipe (50') is the same diameter as the first injection short pipe (A), which is connected to the second injection short pipe (50') in Figure 10. An outer tube (51) and an inner tube (61') are provided concentrically.

Male thread (57') to be screwed to the tip of the short injection tube
However, there is a female thread carved into the rear end for connecting the next injection short tube or swivel (■).

Therefore, in order to obtain a long injection tube, first connect the first injection tube 6I to the five caps with digging blades as shown in FIG.
Then a second injection short tube (so') and a third injection tube of the same type.
Fourth injection short pipe (50 pipes will be installed in series).

The injection pipe (500) connected in this way will be as shown in Fig. 11 and will be entered into the ground in front (Ql), but the method of entry of this injection pipe (500) and how to carry out it will be explained below. Although the apparatus is basically the same as that of the first embodiment, the differences will be mainly explained.

First, the first injection short pipe t!il shown in FIG. 9 is connected to the rear end of the cap with digging blade (5") (see FIG. Remove it and push it outward using a linear motion hydraulic motor.

When one short injection tube has been pushed out, insert a stopper to hold the position, put the second short injection tube into the holding cylinder Uη, close the cover U8, and then linearly remove it again using the hydraulic motor (19). By repeating this process, the injection pipe (500) can advance into the ground (9) to a desired depth and the injection work can be performed in the same manner as in the first embodiment.

(Example 3) An example will be described in which a cap with an excavating blade (51) shown in FIG. 12 and the one shown in FIG. 9 are used as the injection short pipe.

This example is also basically the same as the first example, and the explanation will focus on the points that differ from it.

First, the cap (5'') with a digging blade fitted into the exit opening (4) is as shown in Fig. 12, and one digging blade (50) is formed at the tip of the cap (5''), which is connected to the main body (5''). 502"). On the front outer periphery of this main body part (502), a male thread (504") is carved to engage with a female thread carved on the inner peripheral wall of the grout hole.The rear outer periphery has a smaller diameter. The body part (50
A connecting part (503'') is connected to the connecting part (503''), and a male thread is carved on the outer circumferential wall of the connecting part (503''), and a tool holding part (505'') is formed behind the connecting part (503''). A packing (100) is inserted between the smooth part and the exit port,
It is held down by a packing holder (110) so that it does not pop out.

To advance the injection pipe into the front ground (9), connect the injection short pipe mark as shown in Fig. 9 to the connection part (503'') of the cap with excavation blade (51) as described above. If it is short as shown in Figure 11, the second
Add some injection short tubes (50") which can also be called short tubes. This second injection short tube (50" has almost the same structure as the first injection short tube side, but the tip of the small diameter part (64) is The only difference is that the injection tube (500) connected in this way is opened to the outside by penetrating the tip surface (top surface in FIG. 9).
As shown in the figure, the specific method of connection is the same as in the first embodiment, and once the connection is completed, the short injection tube 6C is first moved forward while applying rotational force to the short injection tube 6C. If the cap with excavator blade (5") comes off the outlet (4) and comes out of the machine, it is not necessarily necessary to apply rotational force to the short injection pipe I5C, and just applying a linear motion will cause the injection pipe (500) to reach the ground. I am forced to go inside.

After advancing one injection short tube side, connect the next second injection short tube (50) while preventing the injection tube (500) from going backwards into the machine using the - key, and then remove the injection tube (50). Then, the injection pipe (500) is again advanced into the ground ahead by the motor.

Once the injection pipe (500) can be advanced as shown by the dotted line in Fig. 1, a swivel (S) is attached to the rear end and the soil improvement material or chemical solution is injected, but this method is described in the second embodiment. Since it is the same as that described above, the explanation will be omitted.

(Example of the pond) Although the three embodiments have been described above, it is natural that multiple pipes such as double pipes and triple pipes can be used in the first embodiment, and in that case, It is sufficient to carve a thread as shown in FIG. 7 on the outer peripheral surface of a double pipe as shown in FIG. 9 (including other multi-ply pipes).

Also second. It goes without saying that a single pipe can be used in the third embodiment as well, and in that case, the outer circumferential surface of the single pipe is made smooth.

Furthermore, in addition to the ones shown in the drawings, various known injection tubes can be used, and the known injection tubes can be divided into lengths that are easy to work in the tunnel and then used by connecting them. You can also do it. As a known injection tube that can be used as the injection tube of the present invention, Japanese Patent Application Laid-Open No. 61-247
Examples include those shown in Publication No. 21. Further, the advancement of the injection pipe into the ground can be carried out manually using a tool or the like without using the pressing device as in the embodiment, or two kinds of modified devices can be used.

(Effect) According to the method for improving the ground in front of the first invention of the present application, excavation is stopped when necessary and the injection pipe is inserted into the ground in front from the inlet drilled in the front end surface of the shield excavator or the side wall surface in the vicinity thereof. Since soil improvement materials and chemical solutions can be injected immediately after advancing, construction work can be carried out safely and efficiently by preventing disturbances in earth pressure and accidents caused by ground collapse due to pressure control errors.

In particular, in this invention, the cap with the excavation blade fitted to the entry port connects the short injection pipe as it is and advances into the ground in front as the tip of the injection pipe. Compared to the type that is inserted into the outlet and allows the injection pipe to advance to the ground in front, the moment the cap is removed, dirt, muddy water, sludge, spring water, etc. do not enter the machine, preventing the ground from collapsing. Can be done.

■ The cap can be used as it is as a cutting blade for the injection pipe, making it convenient and work efficient.

■ There is a digging blade at the tip of the cap, which can be used as a cutting blade at the tip of the injection pipe to advance into the ground without water, so there is no need to perform separate excavation work, and excavation work and injection pipe installation can be done at the same time, making it efficient. In addition, since the injection pipe and the ground are in close contact, improved materials and improved chemical solutions can be injected over long distances at high pressure.

■ Since the segment also has a cap with a digging blade, it is possible to backfill gaps created around the outer periphery of the segment using the same method, making the ground more stable.

According to the device of the second invention of the present application ■ For entrances drilled in various directions.

By simply turning the handle and changing the angle, it is possible to advance the injection tube from several exit ports with one device.

■ Excavation and injection pipe setting can be done at the same time.

■ By connecting short injection tubes, a long injection tube can be obtained, allowing injection to the desired depth.

■ You can select any injection tube, so 1 shot is 1.5
Shot 2 injection becomes possible.

According to the shield excavator of the third invention of the present application, (1) Ground improvement material or chemical solution can be injected at any position during tunnel excavation, so safe work can be performed.

■ No water, dirt, etc. will enter the machine during the injection process or when the injection pipe goes in and out.

According to the cap with a digging blade according to the fourth invention of the present application, since there is a digging blade at the tip, 2 it can be used as it is for both digging and as a part of the injection pipe, so the injection pipe can be exited without leaving the entrance open even for a moment. It is possible to retire.

[Brief explanation of the drawing]

FIG. 1 shows how a shield excavator advances an injection pipe to improve the ground in front during tunnel formation. FIG. 2 shows the state of the exit hole drilled in the front end face of the shield excavator, and is a model view of the shield excavator as seen from the front. FIG. 3 shows an inlet formed in a part of the front end surface and a part of the side wall surface of the shield excavator, and a cap with an excavator blade fitted therein. FIG. 4 shows a part of the front end surface of the shield excavator, and shows a cap with an excavator blade fitted into the inlet. FIG. 5 is a diagram showing a cross section taken along line II in FIG. 3. FIG. 6 is a cross-sectional view taken along the line -■ in FIG. 4. Figures 7 and 9 show the injection short tube, and Figure 7 shows 1.
Double pipe, Figure 9 shows a double pipe. FIG. 8 is a diagram showing the I-1 cross section in FIG. 7. Figures 10 and 11 show injection pipes in which a short injection pipe is connected to a cap with a digging blade.
The one in Figure 11 shows a double pipe. FIG. 12 shows an example of another type of cap with an excavator blade, and shows how it is fitted into an exit hole formed in the front end face of a shield excavator. 1... Shield excavator 2... Front end surface 3... Side wall surface 4... Outlet 5... Cap with excavation blade 9... Front ground 15... Motor 1
7... Holding cylinder 30... Injection short pipe 34...
Guide hole 38... spout 39... injection port 5
0... Injection short pipe 61... Inner pipe 54...
Cavity 59...Liquid B injection hole 60...Liquid A injection port 58...Spout ports 300, 500...
Injection tube 11 Kunise Z self figure 5 age 6

Claims (1)

[Scope of Claims] 1) An injection pipe outlet is drilled on the tip face of the shield excavator or the side wall face near it, and a cap with a digging blade is attached thereto. A method for improving the ground in front of a shield excavator, in which an injection pipe is connected to a cap provided at the front end of the shield excavator, and with the cap attached to the tip, the injection pipe is advanced into the ground in front of the shield excavator to inject a ground improvement material. 2) A method for improving the ground in front of a shield excavator as set forth in claim 1, wherein a plurality of injection pipes are advanced into the ground in front while being joined in the length direction. 3) A method for improving the ground in front of a shield excavator according to claim 1 or 2, wherein the injection pipe with a cap with a digging blade attached to the tip is advanced into the ground in front without water. . 4) Ground improvement in front of a shield excavator according to claim 1 or 2, in which the injection pipe with a cap with a digging blade attached to the tip is advanced into the ground in front using water. Method. 5) In addition to injecting improvement materials and improved chemicals into the ground in front of the shield excavator, the entrance (
Insert a cap with a digging blade (5''') into the cap with a digging blade (5'''), connect the short injection pipes (30) and (50) to this, and leave it attached to the tip of the cap with a digging blade (5'''). The injection short pipe is successively advanced out of the segment, and a press-in device is installed at the rear end to forcefully feed backfilling material, improvement material, and improved chemical solution into the injection pipe, into the gap between the segment and the surrounding ground, and into the surrounding ground.
The front ground improvement method according to any one of claims 1 to 4, wherein a backfill material, a soil improvement material, or an improvement chemical solution is injected. 6) An injection tube outlet (4) is bored in the tip face or the side wall near the tip face, and a cap (5) with a digging blade is attached to the outlet (4) so that it can advance only outward. shield excavator (1), injection pipes (300), (500),
A forward ground improvement device during shield excavation, comprising a pressure feeding device that presses ground improvement material into the injection pipe. 7) An injection tube outlet is drilled on the tip surface or the side wall near the tip surface, and a cap (5) with a digging blade is attached to the outlet (4).
The shield tunneling machine (1) is installed in a watertight manner so that it can only advance outward, and the injection pipes (300) and (500)
, an extruder for advancing the injection pipe to the ground in front of the shield excavator through the exit port (4), and a pressure feeding device for pressurizing the ground improvement material into the injection pipe. Improved equipment. 8) An injection tube outlet (4) is bored in the tip face or the side wall near the tip face, and the cap (5) with a digging blade can be inserted into the outlet (4) in a watertight state so that it can advance only outward. Shield excavator installed. 9) A drilling machine with a drilling blade (501) at the tip and a male thread carved into the entire or part of the outer periphery of the main body to engage with a female thread formed on the inner peripheral wall of the injection pipe outlet (4). Cap with blade. 10) Excavation where there is a digging blade (501) at the tip and a stop part is formed on the main body connected to it so that it does not go inward of the shield excavator but can freely advance outside. Cap with blade. 11) A water guide hole is drilled through the center of the cap with a digging blade, and a check valve is installed in the middle of the hole to block inflow from the tip but allow outflow from the rear end. 11. The cap with excavation blade according to claim 9 or 10, which allows the injection pipe to go underground even when water is present.