JP2683879B2 - Double tube rod loose injection device and loose injection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double pipe rod loose injection device and a loose injection method.

[0002]

2. Description of the Related Art When drilling to an injection range using a double-tube rod and then performing loose injection using the rod as an injection tube, if the slow injection is performed directly, the injected slow injection will occur. Since the injectable injection escapes toward the ground through the circumferential gap of the outer periphery of the rod, first, the quick-injection injection is injected to form the grout packer, and then the slow-injection injection is performed. So-called compound injection is required. Such a process of injecting the quick-setting injecting agent complicates the operation and the apparatus and is not preferable.

Conventionally, a double pipe rod is used for drilling, but with this, as the drilling progresses, both the inner and outer pipes must be screwed together, which is troublesome and a large loss of work time is required. .

Further, during drilling, the double pipe rod is usually rotated and hit, but since these are transmitted to both the inner and outer pipes, it is necessary to use high-strength inner and outer pipes, which results in high weight. It was inconvenient to use and handle.

[0005] The present invention has been made to solve such a conventional problem.

[0006]

SUMMARY OF THE INVENTION The present invention comprises a double tube rod for injecting a loose injection agent, the double tube rod having an outer tube integrally provided with a tip device portion at its tip, The inner tube is detachably inserted into and coupled to the outer tube, and the inner tube is provided with a side hole at a side portion of the tip portion with the tip closed, and the tip device unit is provided with a pipe axial direction in a central portion of the device. A first discharge passage that opens, a second discharge passage that opens in the pipe axis direction at a position deviated from the central portion of the device, and an outer peripheral portion of the tip device portion that is substantially flush with the outer peripheral surface of the outer pipe. And a connecting passage for communicating the inside of the packer portion with the inner pipe of the double pipe rod, and the upper portion of the first discharge passage is detachable from the tip of the inner pipe. The insertion portion that can be freely inserted and connected is configured, and the outer pipe is a single pipe below the insertion portion of the first discharge passage. When the double tube rod is constructed from the inner and outer tubes, the inner tube is pushed down from the first position to the second position below it by holding the first position to close the communication passage. At this second position, a cylindrical valve body is provided which is installed so as to communicate the inside of the inner pipe with the communication passage through the side hole at the lower end thereof, and the first and second discharge passages are individually or commonly equipped with a reverse valve. The double tube rod loose injection device characterized in that a stop valve is provided.

Furthermore, the present invention is a method for performing slow injection using the apparatus according to claim 1, wherein only the outer tube of the inner and outer tubes forming the double tube rod is used for drilling. And forming a double pipe rod by inserting and connecting an inner pipe into the outer pipe after drilling, and after forming the double pipe rod, from the inside of the inner pipe to the side hole at the lower end and the side. A pressurized fluid is supplied to the inside of the packer portion through a communication passage communicating with the hole through the tubular valve body, the packer portion is expanded in the pipe radial direction to seal around the outer pipe, and then the second pipe is inserted between the inner and outer pipes. The present invention relates to a loose-filling injection method characterized by injecting a loose-filling injection agent into the ground through a discharge passage.

[0008]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In the apparatus of the present invention, the double tube rod 1 is composed of an outer tube 3 and an inner tube 2 which is detachably inserted and connected to the outer tube 3, as shown in the exploded view of FIG. ing.

The inner tube 2 is closed at its tip and is provided with a side hole 16 (see FIG. 3) at the side of the tip.

The outer tube 3 is integrally provided with a tip device portion 4 at its tip.

As shown in FIG. 2, the tip device portion 4 is screwed and coupled to the inner peripheral thread portion 6 at the lower end portion of the outer tube 3 at the outer peripheral thread portion 5 at the upper portion.

The tip device portion 4 has a first discharge passage 7 which is opened in the tube axis direction at the center thereof, and at least one, for example three, which is opened in the tube axis direction at a position deviated from the center portion. 4) of the second discharge passage 8 and the outer peripheral surface of the outer tube 3 are fitted to the outer peripheral portion of the tip device portion 4 so as to be substantially flush with the pressurized fluid to be supplied and discharged through the communication passage 9. And a packer portion 10 that expands and contracts in the radial direction of the pipe.

The upper portion of the first discharge passage 7 constitutes an insertion portion 11 which is detachably inserted and joined to the tip portion of the inner tube 2, and in FIG. 3, inner and outer peripheral threaded portions 12a are formed as insertion and joining means. 12
Although the screw coupling means consisting of b is shown, other coupling means by elastic fitting of unevenness may be applied.

Below the insertion portion 11 of the first discharge passage 7,
A cylindrical valve body 13 having a valve hole 14 on the side is installed.

As shown in FIG. 2, the tubular valve element 13 is held at the upper limit of the first position by the holding spring 15 when the outer tube 3 is a single tube.

When the tubular valve body 13 holds the first position, the position of the valve hole 14 and the communication passage 9 are vertically displaced as apparent from FIG. It is closed by 13. Further, since the valve body 13 is tubular,
The first discharge passage 7 maintains a state in which it is opened in the pipe axis direction, that is, a state in which drilling water can be supplied.

On the other hand, in the state where the inner pipe 2 is inserted and connected in the outer pipe 3 to form the double pipe rod 1, the valve body 13 is lowered by the inner pipe 2 against the holding spring 15 as shown in FIG. And is held in a second position below the first position.

When the valve body 13 holds the second position,
As is apparent from FIG. 3, the side holes 16 at the lower end of the inner pipe 2,
The upper and lower positions of the valve hole 14 and the communication passage 9 are aligned with each other, so that the inside of the inner tube 2 is communicated with the inside of the packer 10 and the pressurized fluid supplied and discharged through the inner tube 2 such as a non-compressed fluid such as water causes the packer 10 to move. The scaling operation is possible. Inner tube 2
Since the tip end of the inner pipe 2 is closed,
Closed by Therefore, after the double tube rod 1 is constructed, the first discharge passage 7 is used exclusively for the expansion / contraction operation of the packer unit 10.

As long as the side hole 16, the valve hole 14 and the communication passage 9 are vertically aligned, even if the positions are displaced in the direction around the pipe, the communicating state is still maintained in the valve hole 14,
Circumferential grooves 14a and 14b are formed on both outer sides.

The first discharge passage 7 and the second discharge passage 8 are gathered together in the lower portion of the tip device portion 4, and a check valve 18 is installed in the gathering passage 17.

The check valve 18 includes a ball valve 18a and the valve 1a.
A spring 18b for urging 8a from the lower side in a direction to always close it.
Although the configuration of and is shown, other configurations may be used.

A tip bit 1 is provided at the tip of the tip device section 4.
9 is fixed by applying, for example, a screwing means, and discharge ports 19a communicating with the collecting passage 17 are formed in the tip bit 19 at four positions (see FIG. 5) inclined obliquely outward, The discharge ports 19a ... Are opened on the lower surface of the tip bit 19. The cutting edge 19b is provided on the outer peripheral portion of the tip bit 19.
Are attached and fixed to a plurality of places at appropriate intervals in the direction around the pipe.

The outer tube 3 is composed of a fixed length tube 3a and a short tubular joint fitting 3b for sequentially joining the low length tubes 3a.

The outer pipe 3 is a portion which is subjected to rotation and impact during drilling, and a steel pipe having high strength, for example, a relatively thick wall, is used like the conventional product.

Like the outer tube 3, the inner tube 2 is composed of a fixed-length tube 2a and a short tubular joint fitting 2b for sequentially joining the fixed-length tube 2a. After drilling, the double-tube rod 1 is attached. It is inserted into the outer tube 2 for construction, and as shown in FIG. 3 , at its tip end, it is inserted and coupled in the first discharge passage 7 (see FIG. 2) at the center of the tip end device portion 4 . There is.

Since the inner pipe 2 is inserted into the outer pipe 3 after drilling to form the double pipe rod 1, unlike the conventional inner pipe which is rotated and hit during drilling, high strength is not particularly required. For example, a plastic tube is sufficiently durable.

The second discharge passages 8 may be independently opened on the lower surface of the tip pit 19 without being combined with the first discharge passages 7. In this case, a check valve is provided in each of the second discharge passages 8.

One implementation situation of the slow injection molding method by the device of the present invention is schematically shown in FIGS. 6 (a) to 6 (f) in the order of steps.

FIG. 6A shows the situation of the drilling process, in which drilling is performed by the outer tube 2 alone.

In the drilling step, as shown in FIG.
The swivel 20 for drilling is provided on the upper end of the uppermost fixed length tube 3a of the outer tube 3.
Is fixedly attached through the joint metal fitting 3b.

The drilling swivel 20 has a fixed tubular member 21 which is coaxially connected to the upper end of the outer tube 3 via a joint metal fitting 3b and has a fixed upper end closed tubular member 21, which is fixed to the outer peripheral surface side of the tubular member 21 in the direction around the axis. And a slide ring 22 provided so as to be rotatable at a position, and a drilling water supply port 23 attached to the slide ring 22 is attached to the slide ring 22 so as to coincide with the supply port 23. The first through hole 24 formed, the peripheral groove 25 formed on the inner peripheral surface of the sliding ring 22 so as to communicate with the through hole 24, and the fixed tubular member 21 formed so as to open in the peripheral groove 25. The outer pipe 3 is communicated with the second through hole 26. At the upper end of the fixed tubular member 21, there is provided a connecting portion 27 for connecting with a percussion rotation imparting device (not shown) for imparting rotation and percussion to the outer tube 3 in a usual manner.

The structure of the swivel 20 for boring is as follows.
There is no substantial difference from the conventional drill swivel applied to single pipe drilling such as casing digging.

When the outer pipe 3 is in the single pipe state, the connecting passage 9 to the packer portion 10 is closed by the valve body 13 as shown in FIG.
The drilling water supplied from the outer pipe 3 (see FIG. 7) passes through the outer pipe 3 through the first and second discharge passages 7, 8 ... It will be injected into the ground from the discharging outlets 19a.

As in the case of conventional single pipe digging, the drilling is performed by the drilling guide by the drilling water while giving the impact and rotation to the outer pipe 3, the drilling guide by the tip bit 19 and the propulsive force generated by the impact. This drilling is continued until the predetermined depth is reached while sequentially connecting the standard length pipe 3a with the joint fitting 3b.

In the drilling step, since the outer pipe 3 may simply be added, it is possible to reduce the labor required for the addition of the inner pipe and the outer pipe as compared with the double pipe digging, and to perform the drilling work efficiently. It can be carried out.

After the drilling reaches a predetermined depth, the drilling is stopped, the drilling swivel 20 is removed from the upper end of the outer pipe 3, and then the outer pipe 3 is placed in the outer pipe 3 as shown in FIG. The inner tube 2 is inserted to form the double tube rod 1.

In the state where the double pipe rod 1 is constructed, as shown in FIG. 3, the valve body 13 resists the holding spring 15 by the inner pipe 2 from the upper limit of the first position to the lower position of the second position. As a result, the inside of the inner pipe 2 is pushed through the side hole 16, the valve hole 14 and the communication passage 9 at the lower end thereof in order, and the packer unit 1
0, so that the packer unit 10 can be expanded and contracted using the inner tube 2. By the way, since the tip of the inner pipe 2 is closed, the first discharge passage 7 is closed by inserting and connecting the inner pipe 2.

On the other hand, the inner space 28 of the outer pipe 3, that is, the circumferential gap 28 between the inner and outer pipes 2, 3 is communicated with the discharge ports 19a of the tip bit 19 through the second discharge passages 8 and the collecting passages 17 in sequence. The outer tube 3 is used to inject the loose injection material into the ground.

After the double pipe rod 1 is constructed from the inner and outer pipes 2 and 3, a double injection swivel 29 is set on the upper end of the rod 1 as shown in FIG.

The upper swivel 2 of the double swivel 29
9, a supply port 3 communicating with the inner pipe 2 as shown in FIG.
0, and the lower end swivel 29b is provided with a supply port 31 which communicates with the circumferential gap 28 between the inner and outer pipes 2, 3, respectively, and the communication means between the supply ports 30, 31 and the inner pipe 2, circumferential gap 28 is Since it is the same as the case of the drilling swivel 20 shown in FIG. 7, its detailed description is omitted.

The structure of such a double swivel 29 for injection is substantially the same as the known double swivel conventionally applied to a double tube rod.

After the double swivel 29 is installed on the double pipe rod 1, the upper swivel 2 as shown in FIG. 6D.
When pressurized water is supplied into the inner pipe 2 through the supply port 30 of 9a, the pressurized water passes through the inner pipe 2 from the lower end side hole 16, the valve hole 14 and the communication passage 9 in sequence, as shown in FIG. 10 and expands the packer portion 10 in the pipe radial direction, so that a mouth packer a is formed around the outer pipe 3 at the lower end of the double pipe rod 1.

In the composite injection method, the mouth packer a functions to seal the gap around the outer tube 3 similarly to the mouth packer formed by instant injection.

After the mouth packer a is formed in this way, a loose injection agent is applied to the peripheral gap 2 between the injection port 31 of the lower end side swivel 29a and the inner and outer tubes 2 and 3 as shown in FIG.
8, second discharge passage 8, collecting passage 17 and discharge port 19a
By sequentially injecting into the ground, the infiltration solidified body b can be formed in the ground.

When the formation of the permeation-solidified body b by the injection of the slow-moving infusate is completed, the pressure in the packer section 10 is released to shrink the packer section 10, and then the packer section 10 is filled with 2 as shown in FIG.
By pulling up the heavy pipe rod 1 by one step, loose injection can be performed at this pulling position in the same manner as above.

By repeating the step-up in the same manner, the ground can be improved by the loose-filling injection material as in the conventional composite injection method.

[0048]

According to the present invention, the outer tube is drilled alone to form the double tube rod, and then the inner tube is used to expand the packer portion, and thus the mouth packer is formed, and the osmotic solidified body is formed by loosening injection. Since the structure is such that it can be formed, the following effects can be obtained.

(A) Since the outer pipe alone can be drilled, the screw joint can be made only with the outer pipe, and the time required for the screw joint can be shortened as compared with the conventional double pipe digging which requires the screw joint for both the inner and outer pipes. Work efficiency can be improved.

(B) Since the mouth packer can be formed by the expansion of the packer portion, the step of injecting the quick-setting injectable agent, which is found in the composite injection, can be omitted, and the formation of the permeable solid material by the slow-injection agent can be instantaneously performed. It can be carried out without consuming an injectable injection agent, and is economically superior.

(C) Since no instantaneous injection agent is used, 2
The cause of trouble such as clogging of the heavy pipe rod can be eliminated.

(D) Drilling can be performed by using the outer tube alone,
Since the inner pipe may be inserted and installed in the outer pipe after drilling, the inner pipe only needs to have a strength enough to withstand the injection pressure.For example, a plastic pipe can be sufficiently durable and the inner pipe can be reduced in weight. it can.

[Brief description of the drawings]

FIG. 1 shows an example of a double tube rod in the device of the present invention,
It is a longitudinal cross-sectional view which decomposes | disassembles and shows in an outer pipe.

FIG. 2 is an enlarged cross-sectional view of a distal end device portion in a single pipe state of an outer pipe.

FIG. 3 is an enlarged cross-sectional view of a distal end device section in a state where a double tube rod is composed of inner and outer tubes.

FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 2;

FIG. 5 is a bottom view of FIG. 2;

FIG. 6 is a schematic explanatory view showing one implementation situation of a slow injection molding method by the device of the present invention in the order of steps (a) to (f).

FIG. 7 is an enlarged vertical sectional view showing how the swivel for drilling is attached.

FIG. 8 is an enlarged vertical sectional view showing a mounting state of a double swivel.

[Explanation of symbols]

 1 Double pipe rod 2 Inner pipe 3 Outer pipe 4 Tip device part 5 Outer peripheral screw part 6 Inner peripheral screw part 7 First discharge passage 8 Second discharge passage 9 Connection passage 10 Packer part 11 Insert part 12a Inner peripheral screw part 12b Outer periphery Screw part 13 Cylindrical valve body 14 Valve hole 15 Holding spring 16 Side hole 17 Collecting passage 18 Check valve 19 Tip bit 19a Discharge port 20 Drilling swivel 21 Fixed tubular member 22 Sliding ring 23 Supply port

Claims (3)

(57) [Claims] 1. A double tube rod for injecting a loose injection agent, wherein the double tube rod has an outer tube integrally provided with a tip device unit at its tip, and is detachably inserted into the outer tube. And a first discharge passage opened in the central part of the device in the axial direction of the device, and the inner device is provided with a side hole at a side part of the tip part. The second discharge passage, which opens in the axial direction of the pipe at a position deviated from the central part of the device, is expandable and contractable in the radial direction of the pipe provided on the outer peripheral part of the tip device part so as to be substantially flush with the outer peripheral face of the outer pipe. A packer part and a communication passage for communicating the inside of the packer part with the inner pipe of the double pipe rod, and the upper portion of the first discharge passage is detachably insertable and connectable with the tip of the inner pipe. And the connecting passage is closed below the insertion portion of the first discharge passage when the outer pipe is a single pipe. When the double tube rod is constructed from the inner and outer tubes while holding the first position, the inner tube pushes down the holding spring from the first position to the second position below it, and at this second position A cylindrical valve body that connects the inside of the inner pipe to the communication passage through the side hole at the lower end is installed and installed, and the first and second discharge passages are provided with a check valve individually or in common. A double tube rod loose injection device characterized in that 2. The double pipe rod loosening and injecting apparatus according to claim 1, wherein the outer pipe is detachably provided with a drilling swivel for drilling the outer pipe alone. 3. A method for performing loose injection using the apparatus according to claim 1, wherein only the outer tube of the inner and outer tubes constituting the double tube rod is used for boring. Including a step and a step of inserting and connecting an inner tube into an outer tube after drilling to form a double tube rod, after forming the double tube rod, a side hole at a lower end portion of the inner tube and the side hole A pressurized fluid is supplied into the packer portion through a communication passage communicating with the tubular valve body, and the packer portion is expanded in the pipe radial direction to seal around the outer pipe,
Next, a slow-moving injection method characterized by injecting a slow-moving injectable agent into the ground through the second discharge passage from between the inner and outer pipes.