JP6804901B2 - Chemical injection method and equipment - Google Patents

Description

The present invention relates to an injection method of injecting an injection chemical solution (for example, cement milk) into the ground using an injection device.

In the injection method, a boring hole is excavated in the ground to be constructed and a chemical injection device is inserted.
As shown in FIG. 12, the chemical injection device 100 includes an outer tube 11 and an injection inner tube 12, and the outer tube 11 is formed with a plurality of injection ports 11A at predetermined intervals in the longitudinal direction, and is formed in the longitudinal direction. An elastic member 11B having a function of a check valve is provided at each injection port forming position.
The outer tube 11 is formed in a hollow tubular shape, and a chemical solution injection tube 12 (inner tube with a packer) provided with a chemical solution supply port 12A (discharge port) and a packer 12B is inserted into the hollow space of the outer tube 11.

As shown by the dotted line (virtual line) in FIG. 12, when injecting the drug solution, the injection mechanism 12C is positioned in the area where the drug solution should be injected, and the inner tube 12 with a packer is positioned at the position corresponding to the injection port 11A of the outer tube 11 ( The chemical solution supply port 12A of the chemical solution injection tube) is positioned, and the packer 12B is inflated. By expanding the packer 12B, the injected drug solution supplied from the drug solution supply port 12A to the hollow portion of the outer tube 11 is discharged only from the injection port 11A of the outer tube 11 in the region where the drug solution should be injected (arrow CP). When the chemical solution is discharged (arrow CP), the elastic member 11B (sleeve-shaped elastic member) having the function of a check valve is deformed from the state shown by the solid line to the state shown by the dotted line.
When the chemical solution injection is completed, the packer 12B is contracted to pull up the inner tube 12 with the packer (moving upward in the vertical direction), and the injection mechanism 12C is positioned in the next planned injection area (the area where the chemical solution should be injected). Then, the packer 12B is expanded again in the next planned injection region to inject the chemical solution. In this way, the drug solution is sequentially injected in the area where the drug solution should be injected.

However, since the elastic member 11B (sleeve-shaped elastic member) having the function of the check valve shown in FIG. 12 is used as a valve for preventing backflow, the thickness dimension (reference numeral δ) of the elastic member 11B is used. Only the outer tube 11 protrudes outward in the radial direction. In FIG. 12, the thickness dimension of the elastic member 11B is indicated by reference numeral δ.
Since the elastic member 11B having the function of the check valve by the thickness dimension δ protrudes outward in the radial direction of the outer pipe 11, as shown in FIG. 13, the function of the check valve is provided on the inner wall surface of the boring hole H. The lower end portion 11BE of the elastic member 11B that has the elastic member 11B interferes with each other, and becomes a resistance when the chemical liquid injection device 100 is inserted into the boring hole H. In particular, as shown in FIG. 13, when the drilling device 13 is provided at the tip of the chemical solution injection device 100 and the chemical solution injection device 100 is inserted into the boring hole H while drilling the boring hole H, the boring hole H is formed. Since the inner diameter of H is equal to the outer diameter of the chemical injection device 100, the resistance due to the lower end portion 11BE of the elastic member 11B having the function of a check valve interfering with the inner wall surface of the boring hole H becomes large. In FIG. 13, reference numeral 12 represents an inner tube with a packer (chemical injection tube).
In addition, the lower end 11BE of the elastic member 11B may interfere with the inner wall surface of the boring hole H, so that the elastic member 11B having a check valve function may be worn or damaged and may not function as a valve. Also exists.

As another conventional technique, a technique capable of executing chemical injection even in a region directly under an existing structure has been proposed (see Patent Document 1).
However, such a prior art (Patent Document 1) cannot solve various problems due to interference between the elastic member having the function of the check valve and the inner wall of the boring hole described above.

Japanese Unexamined Patent Publication No. 2014-125781

The present invention has been proposed in view of the above-mentioned problems of the prior art, and can reliably exert a function as a valve for injecting a chemical solution, does not interfere with the inner wall surface of the boring hole, and can be used for a long period of time. It is an object of the present invention to provide a method of injecting a drug solution using a device having a valve mechanism capable of exerting a function as a valve, and a drug solution injection device used for the method.

The chemical injection method of the present invention
The drilling process for drilling the boring hole (H) and
The outer pipe (1) and the injection inner pipe (2) are provided, and a valve is provided in the outer pipe (1). The valve is formed on the outer peripheral surface (1D) of the outer pipe (1) and is the outer pipe. A groove (1A) extending in the circumferential direction of (1) and two annular elastic members (1C: for example, an O-ring) fitted in the groove (1A) are included in the groove (1A). The injection ports (1B) are formed at equal intervals in the circumferential direction, and the groove (1A) has a side surface (1AA) extending from the outer peripheral surface (1D) of the outer pipe (1) to the bottom surface (1AA) of the groove. However, it does not have an inclined surface, the boundary portion between the side surface and the bottom surface (1AA) of the groove (1A) is composed of a curved surface, and the bottom surface (1AA) is composed of a curved surface. The radial distance (DH: groove depth) of the groove (1A) is the depth at which the annular elastic member (1C) fitted therein does not protrude from the outer peripheral surface (1D) of the outer pipe (1). The two annular elastic members (1C) fitted in the groove (1A) are always urged inward in the radial direction and housed in the groove (1A). The chemical solution injection device (10) for maintaining the above is arranged (inserted) in the boring hole (H), and the chemical solution injection device arrangement step.
The injection step includes an injection step of injecting a drug solution.
When the injected chemical solution is discharged (injected) from the injection port (1B) of the chemical solution injection device (10), the annular elastic member (1C) is deformed and the chemical solution is discharged outward in the radial direction (in the ground). It has a step of forming a flow path (S) (injected into) .
In the step of forming the flow path (S), the annular elastic member (1C) is maintained in a state of being accommodated inside from the groove (1A) and rides on the outer peripheral surface (1D) of the outer pipe (1). Is characterized by being prevented .

In the chemical injection method of the present invention, when the pressure (pressure in the ground or hydraulic pressure in the ground) outside the chemical injection device (10) rises, the annular elastic member (1C) is deformed and the Note It is preferable to include a step of closing the inlet (1B).

Further, in the present invention, the chemical injection device (10) is provided with a drilling device (for example, a drilling bit, a high-pressure water injection mechanism, etc.) at the tip (tip in the drilling direction), and is bored during the drilling step. At the same time as the excavation of H), the chemical injection device (10) is inserted into the boring hole (H), so that the drilling step and the chemical injection device placement step can be executed at the same time.
Of course, the drilling step is executed by a drilling device prepared separately from the chemical injection device (10), and after the boring hole (H) is drilled in the drilling step, the chemical injection device (10) is used. The chemical solution injection device arrangement step may be executed by inserting it into the boring hole (H). In this case, the hole drilling step and the chemical solution injection device placement step are not executed at the same time, and the chemical solution injection device placement step is executed after the hole drilling step.

Further, the chemical injection device (10) of the present invention is
Equipped with an outer tube (1) and an injection inner tube (2)
A valve is provided in the outer pipe (1).
The valve includes two of said outer tube is formed on an outer peripheral surface (1D) and extending grooves (1A) in the circumferential direction (1), fitted to the grooves (1A) of the outer tube (1) an annular elastic member: includes (1C e.g. O-ring),
Wherein the grooves (1A) inlet (1B) are formed at equal circumferential intervals,
The groove (1A) has a side surface (1AA) extending from the outer peripheral surface (1D) of the outer pipe (1) to the bottom surface (1AA) of the groove, but does not have an inclined surface.
The boundary portion between the side surface and the bottom surface (1AA) of the groove (1A) is formed of a curved surface, and the bottom surface (1AA) is formed of a curved surface.
The radial distance (DH: groove depth) of the groove (1A) is a depth at which the annular elastic member (1C) fitted therein does not protrude from the outer peripheral surface (1D) of the outer tube (1). The two annular elastic members (1C) fitted in the groove (1A) are always urged inward in the radial direction and housed in the groove (1A). It is characterized by maintaining .

According to the present invention having the above-described configuration, a groove (1A) is formed in the outer tube (1) outer peripheral surface (1D) of the chemical solution injection device (10), and an injection port (1B) is formed in the groove (1A). Is formed and two annular elastic members (1C: for example, O-ring) are fitted, so that there are two injection ports (1B) formed in the groove (1A) in a state where the injection work is not performed. It is closed by the annular elastic member (1C) of.
When injecting a chemical solution into the ground, when the packer (2A) is inflated and the chemical solution is discharged from the injection inner tube (2), the discharge pressure of the chemical solution (P1: chemical solution injection pressure) becomes the outer tube (1). Acts from the discharge port (1B: that is, the injection port formed in the groove 1A) to the outside in the radial direction (ground side outside the chemical injection device: the ground side on which the injection method should be applied). Due to the discharge pressure (P1: chemical injection pressure), the annular elastic member (1C) is deformed (see FIG. 5), and a gap is formed between the annular elastic member (1C), and the gap is the flow path of the injected chemical. It becomes (S).
Therefore, the chemical solution is discharged outward in the radial direction (injected into the ground) through the gap (S: flow path).

When the injection (discharge) of the chemical solution is completed, the discharge pressure (P1) of the chemical solution acting on the annular elastic member (1C) disappears, so that the deformation of the annular elastic member (1C) is also completed and the annular elasticity The elastic repulsive force of the member (1C) acts to fit into the groove (1A) and close the discharge port (1B).
That is, according to the present invention, the chemical liquid injection flow path (S) is opened only at the time of injection, as in the case of a valve composed of an elastic member (sleeve-shaped elastic member) having a function of a conventional check valve. When not injecting, the drug solution injection flow path (S) is closed.

Here, the annular elastic member (1C) is fitted in the groove (1A), and the radial distance (DH: groove depth) of the groove (1A) is the annular shape fitted therein. Since the elastic member (1C) is set to a depth that does not protrude from the outer peripheral surface (D) of the outer tube (1), the annular elasticity when the chemical injection device (10) is inserted into the boring hole (H). The member (1C) does not interfere with the inner wall surface of the boring hole (H) and does not act as a resistance to movement of the chemical injection device (10) in the boring hole (H).
Therefore, the annular elastic member (1C) is not worn or damaged by the friction caused by the interference between the annular elastic member (1C) and the inner wall surface of the boring hole (H), and the annular elastic member (1C) is a valve. Can be reliably exerted over a long period of time.

In the present invention, when the pressure outside the chemical solution injection device (10) (P2: pressure in the ground or liquid pressure in the ground) rises, the increased external pressure (P2: pressure in the ground or ground) The annular elastic member (1C) is deformed into a state of being pressed against each other by the hydraulic pressure inside, and is strongly pressed against the bottom surface (1AA) of the groove (1A). Therefore, the injection port (1B) of the outer tube (1) is closed more firmly by the annular elastic member (1C).
As a result, even if the pressure in the ground (P2) or the hydraulic pressure in the ground (P2: the pressure outside the chemical injection device 10) rises, the injection port (1B) of the outer pipe (1) has the annular elasticity. Since it is tightly closed by the member (1C), it is prevented that the liquid in the ground (including the discharged injected chemical solution) flows back into the chemical solution injection device (10).

It is explanatory drawing which shows the embodiment of this invention. FIG. 5 is an enlarged partial cross-sectional view showing a cross section of a portion indicated by reference numeral A in FIG. It is an enlarged partial sectional view which shows the sectional shape of the groove in embodiment. FIG. 5 is an enlarged partial cross-sectional view showing an unsuitable cross-sectional shape of the groove. It is explanatory drawing which shows the deformation action of the O-ring at the time of injection of a chemical solution. It is explanatory drawing which shows the direction in which the elastic repulsive force of an O-ring acts. It is explanatory drawing which shows the state which is prevented by the elastic repulsive force of the O-ring at the time of injecting a chemical solution virtually. It is explanatory drawing which shows the action of an O-ring when a drug solution is not injected. It is explanatory drawing which shows the operation when only one O-ring is arranged. It is explanatory drawing which shows the inconvenience when the depth dimension of a groove is large. It is an end view which shows the position of an inlet. FIG. 5 is a partial cross-sectional view showing a main part of a chemical injection device having a valve composed of an elastic member having a function of a conventional check valve. It is explanatory drawing which shows the problem of the prior art of FIG.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 10.
FIG. 1 shows an outline of an embodiment of the present invention, in which a groove 1A extending in the circumferential direction is formed on the outer peripheral surface 1D of the outer tube 1 of the chemical solution injection device 10.
The outer tube 1 is formed of a hollow tubular having a hollow space, and the hollow space is provided with an injection inner tube 2 (indicated by a dotted line in FIG. 1). The injection inner tube 2 includes a packer 2A, and the configuration and operation / effect of the injection inner tube 2 are the same as those of the conventionally known inner tube 12 with a packer described with reference to FIG.
The grooves 1A of the outer tube 1 are formed at a plurality of locations where the chemical solution should be injected in the axial direction of the outer tube 1 (vertical direction in FIG. 1) (in FIG. 1, only one groove 1A in the axial direction is shown. ). Here, the plurality of locations where the chemical solution should be injected are locations where the chemical solution injection port is provided, which will be described later with reference to FIG. The injection inner tube 2 moves in the hollow space in the outer tube 1 and is held at a predetermined position corresponding to the plurality of locations where the chemical solution should be injected.
In FIGS. 1 to 10, for example, four chemical solution injection ports 1B are formed in the groove 1A at equal intervals in the circumferential direction.

In FIG. 2, an injection port 1B is formed in the center of the bottom surface 1AA of the groove 1A having the width direction (vertical direction in FIG. 2) dimension B in the width direction (vertical direction in FIG. 2).
Two O-rings 1C, which are annular elastic members made of an elastic material (for example, rubber), are fitted in the groove 1A so as to close the injection port 1B. At that time, the two O-rings 1C are evenly arranged in the width direction of the groove 1A, and the central axis 1BC of the injection port 1B defines the boundary between the two O-rings 1C.
Further, the depth DH (radial distance) of the groove 1A is a depth at which the O-ring 1C does not protrude from the outer peripheral surface 1D of the outer tube 1 when the O-ring 1C is fitted into the groove 1A, as shown in FIG. Is set to.

FIG. 3 shows the cross-sectional shape of the groove 1A formed on the outer peripheral surface 1D of the outer pipe 1. In FIG. 3, the bottom surface 1AA (region inward in the radial direction) of the groove 1A is formed on a curved surface having a radius of curvature R.
According to the inventor's experiment, when the bottom surface 1AA of the groove 1A is configured by such a curved surface, two O-rings 1C (in FIG. (Not shown) is properly deformed, and it has been confirmed that a flow path of the chemical solution is formed between the two O-rings 1C as described later with reference to FIG.
Further, according to the inventor's experiment, when the pressure outside the outer pipe 1 (pressure in the ground or liquid pressure in the ground) rises, as will be described later with reference to FIG. It has been confirmed that the two O-rings 1C are strongly pressed against the bottom surface 1AA of the groove 1A while being deformed into a state of pressing each other due to the pressure, and the injection port 1B of the bottom surface 1AA is firmly closed.

As shown in FIG. 4, when the bottom surface 1AA-1 of the groove 1A-1 is formed of a flat surface, the action of forming a chemical solution flow path between the two O-rings at the time of chemical solution injection and the outside of the outer tube 1 It has been confirmed by the inventor's experiment that the action of the two O-rings firmly closing the injection port 1B of the bottom surface 1AA-1 when the pressure rises is not exhibited well.
In other words, in the inventor's experiment, when the bottom surface 1AA-1 of the groove 1A is composed of a flat surface (FIG. 4), the bottom surface 1AA is curved when the O-ring fitted in the groove 1A receives pressure. Unlike the case of being composed of surfaces (Fig. 3), it could not be deformed smoothly.

In FIG. 5, two O-rings 1C are fitted in the groove 1A formed on the outer peripheral surface 1D of the outer tube 1. In the state where the chemical injection operation is not performed, the two O-rings 1C are shown by a solid line and are housed in the groove 1A without deformation and without a gap between them. The injection port 1B formed on the bottom surface 1AA of the groove 1A is closed by two O-rings 1C shown by solid lines.
In the state shown in FIG. 5, the outer end portion (left end portion in FIG. 5) of the O-ring 1C does not protrude from the outer peripheral surface 1D of the outer pipe 1.

In FIG. 5, the two O-rings 1C when injecting the chemical solution into the ground are shown by dotted lines. When a chemical solution is discharged from an injection inner tube with a packer (not shown), the discharge pressure P1 (chemical solution injection pressure) of the chemical solution causes the injection port 1B formed on the bottom surface 1AA of the groove 1A to be radially outward (left in FIG. 5). Inject (discharge) the chemical solution.
At that time, the O-ring 1C is deformed like a dotted line due to the discharge pressure P1 (chemical injection pressure), a gap is formed between the two O-rings 1C, and the gap between the two O-rings 1C is the injection chemical. It becomes the flow path S of. Then, the injected chemical solution is discharged outward in the radial direction (left side in FIG. 5) through the flow path S formed by the gap between the O-rings 1C, and is injected into the ground.

When the injection (discharge) of the chemical solution is completed, the discharge pressure P1 of the chemical solution acting on the O-ring 1C disappears, so that the deformation of the O-ring 1C is also completed. As shown in FIG. 6, the O-ring 1C is fitted into the groove 1A by the elastic repulsive force FRI, and the injection port 1B (discharge port) is closed again.
As a result, according to the illustrated embodiment, the chemical solution injection flow path S is opened only when the chemical solution is injected, as in the case of a valve composed of an elastic member (sleeve-shaped elastic member) having a function of a conventional check valve. When the chemical solution is not injected, the chemical solution injection flow path S is closed.

In FIG. 6, the elastic repulsive force FRI of the O-ring IC itself acts on the two O-rings 1C fitted in the grooves 1A formed on the outer peripheral surface 1D of the outer tube 1, so that the O-rings are always within the radial direction. It is urged toward the direction (on the right side in FIG. 6).
As shown in FIG. 6, the elastic repulsive force FRI of the O-ring 1C acts on the bottom surface 1AA of the groove 1A, and the regions R1 and R2 of the bottom surface 1AA receive the elastic repulsive force FRI.
As described with reference to FIG. 5, the two O-rings 1C fitted in the groove 1A formed on the outer peripheral surface 1D of the outer tube 1 are radially outward (chemical solution) from the injection port 1B when the chemical solution is injected. When the discharge pressure P1 (chemical injection pressure) is applied to the ground side outside the injection device, the cross section is deformed from a circular shape by the discharge pressure P1.

On the other hand, the O-ring 1C always has an elastic repulsive force FRI that goes inward in the radial direction.
Therefore, even if the O-ring 1C deforms its cross-sectional shape due to the discharge pressure P1, the state in which the O-ring 1C is housed in the groove 1A is maintained by the elastic repulsive force FRI.
In other words, the elastic repulsive force FRI prevents the O-ring 1C from protruding from the groove 1A and riding on the outer peripheral surface 1D of the outer tube 1 (the state shown in FIG. 7).

Next, with reference to FIG. 8, in the illustrated embodiment, O when the pressure P2 (for example, the pressure in the ground or the hydraulic pressure in the ground) outside the chemical solution injection device 10 rises when the chemical solution is not injected. The action of the ring 1C is shown.
In FIG. 8, the O-ring 1C in a state where the chemical injection operation has not been performed and the pressure P2 outside the outer tube 1 (outside the chemical injection device 10) has not risen is shown by a solid line. In the state of the solid line in FIG. 8 (the state in which the external pressure P2 does not rise), the O-ring 1C is fitted in the groove 1A without being deformed.

On the other hand, the O-ring 1C when the pressure P2 outside the outer tube 1 (chemical injection device 10) rises is shown by a dotted line in FIG. When the external pressure P2 rises, as shown by the dotted line, the O-ring 1C is pressed by the external pressure P2 and collapses in the radial direction (horizontal direction in FIG. 8: the direction in which the pressure P2 acts), and at the same time, the outside. An attempt is made to expand the pipe 1 in the axial direction (vertical direction in FIG. 8). In other words, the two O-rings 1C are crushed in the radial direction (horizontal direction in FIG. 8) and elastically deformed so as to press each other in the axial direction (vertical direction in FIG. 8), and the side surface of the groove 1A and the groove 1A. It is strongly pressed against the bottom surface 1AA. Further, since the two O-rings 1C are crushed in the radial direction (horizontal direction in FIG. 8: the direction in which the pressure P2 acts) and try to expand in the axial direction of the outer tube 1 (vertical direction in FIG. 8), the outside The axial elastic repulsive force FCP of the tube 1 acts.
As a result, the injection port 1B of the outer pipe 1 is closed more firmly by the O-ring 1C, and the liquid in the ground (discharged injection chemical solution, groundwater, etc.) flows back into the outer pipe 1 (chemical solution injection device 10). Is prevented.
Even when the pressure P2 (FIG. 8) is generated outside the chemical injection device 10, the chemical liquid inlet pressure P1 (discharge pressure: for example, FIGS. 5 and 7) at the time of chemical injection is used as the external pressure P2. If it is set to be larger than (P2 <P1), the chemical solution is discharged to the ground and the chemical solution is injected.

Next, with reference to FIG. 9, as an example inappropriate as the illustrated embodiment, a case where only one O-ring 1C is fitted in the groove 1A will be described.
In the illustrated embodiment, as shown in FIGS. 1 to 8, two O-rings 1C are fitted in the groove 1A, and a chemical solution acting radially outward from the injection port 1B of the bottom surface 1AA of the groove 1A. When the discharge pressure P1 (chemical injection pressure) of the above is applied, a gap is formed between the two O-rings 1C, and the gap constitutes the flow path S of the injection chemical. Therefore, a constant flow path S is secured when the chemical solution is injected.

On the other hand, in the example shown in FIG. 9, when the chemical solution is injected, the O-ring 1C and the groove 1A receive the discharge pressure P1 (chemical solution injection pressure) of the chemical solution acting outward in the radial direction from the injection port 1B of the bottom surface 1AA of the groove 1A. It is uncertain whether the chemical solution is discharged from the boundary portion between the side surface (upper side surface or lower side surface in FIG. 9). Therefore, the upper flow path S1 and the lower flow path S2 in FIG. 9 are configured as the flow path of the injection drug solution, or the upper flow path S1 and the lower flow path S2 coexist.
Therefore, when only one O-ring 1A is fitted in the groove 1A as shown in FIG. 9, the flow path for injecting the chemical solution cannot be determined and uniform chemical injection cannot be performed, which is inappropriate.

FIG. 10 shows a case where the depth of the groove 1A is large as a case where the cross-sectional shape of the groove 1A is inappropriate.
In the illustrated embodiment, as shown in FIGS. 1 to 8, the depth DH (radial distance, FIG. 2) of the groove 1A into which the O-ring 1C is fitted is the O-ring 1C fitted in the groove 1A. Is set to a depth that does not protrude from the outer peripheral surface 1D of the outer tube 1.
On the other hand, in FIG. 10, the depth DH1 (radial distance) of the groove 1A into which the O-ring 1C is fitted is set to be very large compared to the diameter dimension of the cross-sectional shape of the O-ring 1C. Therefore, when the O-ring 1C is fitted into the groove 1A, the O-ring 1C moves to the bottom surface 1AA (arrow M).
When the depth DH1 is large, even if the discharge pressure P1 (not shown in FIG. 10) of the chemical solution acts during the injection of the chemical solution, the wall surface of the groove 1A inhibits the elastic deformation of the O-ring 1C. The O-ring 1C does not deform as shown in FIG. Therefore, the flow path of the injected chemical solution cannot be secured, and uniform chemical injection cannot be performed.

The circumferential position of the injection port 1B in the outer tube 1 will be described with reference to FIG.
FIG. 11A shows the case of the embodiment described with reference to FIGS. 1 to 10, and the injection ports 1B are provided at four locations in the circumferential direction at equal intervals. Note that in FIG. 11, the groove 1A formed in the outer tube 1 is not shown.
The number of inlets 1B is not limited to four in the circumferential direction, and as shown in FIGS. 11B and 11C, the number of inlets 1B is 3 in the circumferential direction and 2 in the circumferential direction. It can also be provided at equal intervals.
Although not shown, it is possible to form only one injection port 1B in the circumferential direction, and it is also possible to form five or more injection ports 1B in the circumferential direction.

When constructing the illustrated embodiment, first, a drilling step of drilling a boring hole H (see FIG. 13 showing the prior art) is performed by a conventionally known method.
Next, the step of arranging the chemical solution injection device 10 of the embodiment of the present invention described with reference to FIGS. 1 to 11 is executed in the bored hole H.
Then, the injection step of injecting the chemical solution into the ground from the chemical solution injection device 10 is executed. Here, in the injection step, as described in detail with reference to FIG. 5, the drug solution is discharged after the packer of the injection inner tube 2 with a packer (FIG. 1) is expanded, and the drug solution is injected from the injection port 1B of the drug solution injection device 10. The chemical solution is discharged (injected). When the chemical solution is injected, the O-ring 1C is deformed by the discharge pressure P1 (chemical solution injection pressure) to form a flow path S for discharging the chemical solution outward in the radial direction (injecting into the ground).

Then, in the chemical injection step, if the grooves 1A are formed at a plurality of locations where the chemical solution should be injected in the outer tube 1, the injection inner tube 2 is sequentially moved according to the positions of the injection ports 1B of the plurality of grooves 1A. , While arranging, perform chemical injection into the ground, for example, from the lower region to the upper region.
However, if an injection inner pipe having a plurality of injection nozzles and a plurality of packers is used corresponding to the positions of the plurality of grooves 1A (injection ports 1B) in the outer pipe 1, the ground is simultaneously transmitted from the injection ports 1B of the plurality of grooves 1A. It is also possible to inject a chemical solution into it.

Further, in the illustrated embodiment, as described in detail with reference to FIG. 8, when the pressure P2 (pressure in the ground or liquid pressure in the ground) outside the chemical solution injection device 10 rises, the O-ring 1C Deforms to close the inlet 1B even more tightly.
Further, in the illustrated embodiment, if a drilling device (for example, a drilling bit, a high-pressure water injection mechanism, etc., reference numeral 13 in FIG. 13 indicating the prior art) is installed at the tip (tip in the drilling direction) of the chemical injection device 10. At the time of drilling the boring hole H, the chemical injection device 10 is arranged in the boring hole H at the same time as the drilling of the boring hole H, so that the drilling of the boring hole H and the arrangement (insertion) of the chemical injection device are performed. It can be executed at the same time.
Of course, the boring hole H may be drilled by a drilling device prepared separately from the chemical injection device 10, and after the boring hole H is drilled, the chemical injection device 10 may be inserted into the boring hole H. In this case, the drilling of the boring hole H and the insertion (arrangement) of the chemical solution injection device 10 into the boring hole H are not executed at the same time, and the chemical solution injection device 10 is inserted (arranged) after the drilling of the boring hole H. Placed).

According to the illustrated embodiment, the chemical solution injection flow path S is opened only at the time of injection, as in the conventional technique using a valve composed of an elastic member (sleeve-shaped elastic member) having a function of a check valve. At the time of non-injection, the drug solution injection flow path S is closed.
Here, in the illustrated embodiment, the O-ring 1C is fitted in the groove 1A, and the radial distance (DH: groove depth, see FIG. 2) of the groove 1A is the O-ring fitted therein. Since the ring 1C is set to a depth that does not protrude from the outer peripheral surface 1D of the outer tube 1, the O-ring 1C does not interfere with the inner wall surface of the boring hole H when the chemical injection device 10 is inserted into the boring hole H. , It does not act as a resistance to movement in the boring hole H of the chemical injection device 10.
Therefore, the O-ring 1C is not worn or damaged by the friction caused by the interference between the O-ring 1C and the inner wall surface of the boring hole H, and the O-ring 1C surely exerts its function as a valve for a long period of time. Can be done.

Further, in the illustrated embodiment, when the pressure P2 (for example, the pressure in the ground or the liquid pressure in the ground) outside the chemical injection device 10 rises, the pressure P2 causes the two O-rings 1C to mutually move. It is deformed into a state of being pressed against each other, and is strongly pressed against the bottom surface 1AA of the groove 1A. Therefore, the injection port 1B of the outer tube 1 is closed more firmly by the O-ring 1C (see FIG. 8).
As a result, even if the external pressure P2 (for example, the pressure in the ground or the liquid pressure in the ground) rises, the injection port 1B of the outer pipe 1 is firmly closed by the O-ring 1C, so that it is in the ground. It is prevented that the liquid (including the discharged injected chemical solution) flows back into the chemical solution injection device 10.

It is added that the illustrated embodiment is merely an example and is not a description intended to limit the technical scope of the present invention.
For example, as the annular elastic member, a rubber O-ring is exemplified in the embodiment, but it may be made of another material, and the cross-sectional shape of the annular elastic member may not be circular.

1 ... Outer tube 1A ... Groove 1AA ... Bottom surface 1B ... Injection port 1C ... O-ring (annular elastic member)
1D ・ ・ ・ Outer surface 2 ・ ・ ・ Injection inner tube (inner tube with packer)
10 ... Chemical injection device H ... Boring holes S, S1, S2 ... Chemical flow path

Claims (3)

The drilling process for drilling the boring hole (H) and
The outer pipe (1) and the injection inner pipe (2) are provided, and a valve is provided in the outer pipe (1). The valve is formed on the outer peripheral surface (1D) of the outer pipe (1) and is the outer pipe. A groove (1A) extending in the circumferential direction of (1) and two annular elastic members (1C) fitted in the groove (1A ) are included, and the groove (1A) includes a groove (1A) in the circumferential direction. Injection ports (1B) are formed at equal intervals, and the groove (1A) has a side surface (1AA) extending from the outer peripheral surface (1D) of the outer pipe (1) to the bottom surface (1AA) of the groove. the inclined surface has no, the sides and the boundary portion between the bottom surface (1AA) of the groove (1A) is composed of a curved surface, and the bottom surface (1AA) is constituted by a curved surface, said groove ( 1A radial distance (DH) of) is set to a depth not protrude from the annular elastic member is fitted thereto (the outer peripheral surface of 1C) the outer tube (1) (1D), said groove A chemical injection device (10) that is constantly urged inward in the radial direction to the two annular elastic members (1C) fitted to the (1A) and maintains a state of being housed in the groove (1A). In the process of arranging (inserting) the chemical solution injection device in the boring hole (H) , and
The injection step includes an injection step of injecting a drug solution.
When the injected chemical solution is discharged from the injection port (1B ) of the chemical solution injection device (10), the annular elastic member (1C) is deformed to form a flow path (S) for discharging the chemical solution outward in the radial direction. has a step to be formed,
In the step of forming the flow path (S), the annular elastic member (1C) is maintained in a state of being accommodated inside from the groove (1A) and rides on the outer peripheral surface (1D) of the outer pipe (1). A chemical injection method characterized by the prevention of The chemical injection method according to claim 1, further comprising a step of deforming the annular elastic member to close the injection port when the pressure outside the chemical injection device increases. Equipped with an outer tube (1) and an injection inner tube (2)
A valve is provided in the outer pipe (1).
The valve includes two of said outer tube is formed on an outer peripheral surface (1D) and extending grooves (1A) in the circumferential direction (1), fitted to the grooves (1A) of the outer tube (1) includes an annular elastic member (1C),
Wherein the grooves (1A) inlet (1B) are formed at equal circumferential intervals,
The groove (1A) has a side surface (1AA) extending from the outer peripheral surface (1D) of the outer pipe (1) to the bottom surface (1AA) of the groove, but does not have an inclined surface.
The boundary portion between the side surface and the bottom surface (1AA) of the groove (1A) is formed of a curved surface, and the bottom surface (1AA) is formed of a curved surface.
The radial distance of the grooves (1A) (DH) is set to a depth as not to protrude from the outer peripheral surface of the annular elastic member is fitted thereto (1C) the outer tube (1) (1D) , The two annular elastic members (1C) fitted in the groove (1A) are always urged inward in the radial direction to maintain the state of being housed in the groove (1A). Chemical injection device.

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