JPH0118206B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ground stabilization treatment device using chemical injection.

In recent years, the so-called LAG construction method disclosed in Japanese Unexamined Patent Publication No. 52-48217 has been widely used. The publication states that for drilling, the drilling fluid is fed into the gap between the outer pipe and the inner pipe, the check valve is pushed down, and it is spouted from the spout at the tip, and for injection, one fluid is used to push down the spool valve. A technique in which liquid is discharged from one discharge port, and as the spool valve moves downward, the other liquid is discharged from the other discharge port by crossing the spool valve from the gap, and is brought into contact and mixed at the peripheral wall of the pipe. It is shown.

Although this method and device are extremely effective, the method does not allow injection from the discharge port and discharge from the jet port at the same time, and the device uses a spool valve. Not only does the structure of the injection pipe become complicated, but also there is a risk that the spool valve may malfunction depending on the type of injection liquid.

On the other hand, this type of construction method has a remarkable effect on heterogeneous or complex ground, but depending on the ground, it is effective to naturally improve the ground by using a long gel time chemical solution and letting it penetrate slowly. There is.

The present invention was developed in view of the above circumstances, and
It is possible to inject a chemical liquid at the tip of the injection tube and at the base side thereof, and the purpose is to provide a device that can operate reliably in construction methods that use a combination of fast-setting chemical liquid and slow-setting chemical liquid. It is in.

The present invention will be explained below with reference to specific examples shown in the drawings. Fig. 1 shows an example using a triple tube, in which only the tip of the injection tube is shown, and 1 is the outer tube. A tip tube 3 is connected to the tip of the tube via a joint tube 2 that forms part of the outer tube, and a rod crown 4 is screwed to the tip. 5
1 is a middle tube, 6 is an inner tube, and these inner tube and outer tube 1 according to the present invention constitute a triple tube. Although not shown in the figure, the injection main body extending from the swivel to this tip portion also has a substantially similar triple tube structure.

Reference numeral 7 denotes a guide element in which the lower part of the inner tube 6 is housed. A dispersion chamber 8 communicating with the inner pipe 6 is formed in the guide element 7, and a plurality of dispersion paths 9, 9 are formed diagonally downward from the dispersion chamber 8. It communicates with a spout 12 as a second injection port at the tip of the rod crown 4 via an annular liquid C check valve 10 whose tongue portion 10a is made of rubber or the like and is in contact with the outer peripheral surface of the guide 7.

Further, a guide tube 13 having an inlet 13a is installed in the lower part of the middle tube 5 and the upper part of the guide element 7, and a gap is secured between the guide tube 13 and the inner tube 6. Furthermore, middle tube 5
One side (upper side in Figure 1) is notched, and the outer tube 1
The gap between the two forms a mixing chamber 14. At the upper part (base side) of this mixing chamber 14, the outer pipe 1 and the middle pipe 5
An annular A-liquid check valve 15 with a tongue 15a facing downward is provided between the lower part (tip side) of the mixing chamber 14.
A tongue portion 16 is provided between the guide tube 13 and the guide element 7.
An annular B liquid check valve 16 with a facing upward is provided. A first injection port 17 is formed in the center of the mixing chamber 14.

During injection, liquid C, which is a mixture of two-part curable materials with a long gel time, is delivered to the inner tube 6 through the swivel and the inner tube of the injection tube body at the swivel portion or at the front stage of the swivel. As a result, C
The liquid passes from the dispersion chamber 8 through the dispersion path 9, displaces the tongue 10a of the check valve 10, passes through the tip tube 8 and the rod crown 4, and is ejected downward from the spout 12.

At the same time as this C liquid is injected, AB of the two-component curing material with short gel time is added from the special swivel feed port.
Both liquids are fed respectively, and liquid A is introduced into the gap between the outer tube 1 and the middle tube 5 through the gap between the outer tube and the middle tube of the injection tube main body. In addition, the B liquid is introduced into the gap between the middle tube 5 and the inner tube 6 through the gap between the middle tube and the inner tube of the injection tube body. As a result, liquid A passes through the check valve 15 into the mixing chamber 1.
4, the B liquid flows from the top to the bottom of the inlet 13a.
Then, it passes through the check valve 16 and flows from the bottom to the top of the mixing chamber. As a result, both A and B liquids are mixed in the mixing chamber 1.
4 meet and come into contact at the center, mixing is performed there, and the mixed liquid is discharged from the injection port 17 to the surrounding wall ground.

In this way, when the injection material with a short gel time is injected from the injection port 17, a solid body _G1 of the injection material is generated at a position above the tip of the injection tube.
Since the gel time of the injection material is short, solidification begins immediately after injection, and solidification occurs only in a limited range of the peripheral wall without flowing out.

On the other hand, the C liquid discharged from the spout 12 is injected into the ground surrounding the tip and creates a solid body G ₂ to improve the solid body, but the C liquid, which has a long gel time, remains uncured and a part of it remains uncured. It tries to flow out to the proximal end of the injection tube along the pore wall. However, due to the presence of the solid body _G1 , its outflow is blocked, and as a result, the spout 12
It is possible to make improvements within the desired range, centering on the following.

In this way, it is possible to improve the ground from the tip over a long period of time, and at that time, the outflow of the injection material can be reliably prevented by the pack effect of the solid body G ₁ created on the peripheral wall, and the solid body G ₁ itself also has the effect of improving the ground around the surrounding wall. Furthermore, since the injection work can be performed almost simultaneously, the work efficiency is improved several times compared to separate work.

Note that it is sufficient that the injection of both liquids AB and liquid C are performed almost simultaneously, and there may be a slight difference in time. However, in order to avoid outflow of C liquid, it is not preferable to inject C liquid before feeding AB liquid.

Further, the gel time of the AB solution is preferably within 30 seconds, more preferably within 10 seconds. The gel time of Solution C may be longer than that, but preferably 60 seconds or longer.

If we consider the original function of the device, since the C liquid flow path is independent of the AB liquid flow paths, the C liquid and AB liquid can be injected at the same time. Since the AB liquids are combined and mixed countercurrently in the mixing chamber 14, their miscibility is extremely high. Since it has a triple tube configuration, each flow path is independent, so solidification of the injection material within the tube can be prevented. Also, compared to the conventional method mentioned above, there is no need to use a spool valve, and the structure is simpler.
Moreover, there is no fear of malfunction.

In the above example, the merging is performed inside the mixing chamber 14, but the merging and mixing may be performed outside the tube as in the conventional example. However, mixing within the pipe has better mixing properties.

In Figures 3 and 4, two inner tubes are installed in parallel inside an outer tube instead of a triple tube, and the inside of each inner tube and the gap between the inner tube and the outer tube are separated so that each liquid can flow independently. This figure shows an example of a flow path.

That is, the outer tube 20 of the injection tube main body shown in FIG.
Inside, two inner tubes 21 and 22 are arranged side by side, and in the outer joint tube 23, inner joint tubes 24 and 25 are installed. A B liquid passage 26 and a C liquid passage 27 are formed in parallel in the joint inner tube 24 and communicate with the inner tubes 21 and 22 via joints 28 and 29. A gap is ensured between the outer joint pipe 23 and the inner joint pipe 25, and this gap serves as the A liquid path 30. Further, this A liquid path 30 is not directly illustrated in the figure. The gap A between the outer tube 20 and the inner tubes 21 and 22 is formed through the chamfered portion of the joint inner tube 24 in the front-rear direction in the plane of the drawing.
It communicates with the liquid path 31.

Further, the tip device shown in FIG. 4 is screwed to the injection tube main body, and a connection guide 33 as an inner position according to the present invention is installed inside the outer tube 32. , a B liquid passage 34 which has an inlet 34a on the side, whose tip is closed by a blind plug 34b, and has an inlet 34c formed, and a joint pipe 3 which enters the axis and changes its position slightly to the side
A C liquid path 36 communicating with 5 is formed respectively. On the other hand, a valve seat 38 is disposed at the connection between the joint pipe 35 and the tip bolt 37, and a check valve 39 is installed therein, so that when liquid C is supplied, liquid C pushes down the check valve 39 and enters the second injection port. It is designed to be ejected from a spout 40 as shown in FIG.

Further, a mixing chamber 44 is formed on the peripheral wall of the injection pipe, which is divided by annular check valves 41 and 42 and communicated with a first injection port 43, as in the first embodiment.

The operation of such an example device is easily explained in the first section.
Since this can be determined based on assumptions made in the embodiment, the explanation will be omitted here.

In addition to the effects of the first embodiment, the device of the second embodiment configured as described above has two inner tubes arranged side by side within the outer tube, so that the cross-sectional area of the flow path is equal to that of the two liquids. Since the tube is circular, the flow of the liquid is smooth, and it is possible to solve clogging in the flow path caused by the large contact area of the liquid such as in polymerization tubes, and it is easy to manage the feed rate. Become.

As described above, the present invention is designed to allow injection from the tip on one side and the peripheral wall on the other, so it is ideal for construction methods that use both quick-setting and slow-setting chemicals. In the first injection part, since the two liquids are mixed together, it is possible to reliably achieve packing and improvement by injection of the instant setting chemical liquid.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the first embodiment, Fig. 2 is a schematic sectional view showing the construction method, Fig. 3 is a sectional view showing a part of the injection pipe main body in the second embodiment, and Fig. 4 is a sectional view showing the construction method. It is a sectional view of the tip device. 1... Outer tube, 5... Middle tube, 6... Inner tube, 7...
Guide element, 12... Spout port, 13... Guide tube, 13
a... Inlet, 14... Mixing chamber, 17... Inlet, 20... Outer tube, 21, 22... Inner tube, 32...
...outer tube, 33...connection guide, 43...inlet,
44...Mixing room.

Claims (1)

[Claims] 1. A first injection port is formed in the middle wall of the outer tube, and an inner tube is provided inside the outer tube, and a liquid A path is formed between the outer tube and the inner tube, and an independent B liquid is provided in the inner tube. A liquid path and a C liquid path are formed, and the B liquid path crosses the formation position of the first injection port and moves toward the tip, then breaks through the wall of the inner tube and enters the outer tube, countercurrently with the A liquid path. The C liquid path passes through the inner tube and communicates with the second inlet located at the tip of the first inlet, and the A, B and C liquid paths are mutually connected to each other. A ground stabilization treatment device that is independent.