JPH0995935A - Injection device for ground reinforcing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the back flow of an injected ground reinforcing material, and to reduce the solidification of the ground reinforcing material inside an injecting rod for making its reuse possible. SOLUTION: A cylindrical inner rod is inserted into a cylindrical outer rod 2 to form a double pipe structure, and a packer 4 to freely expand and contract is attached to the middle outer periphery of the outer rod 2, and a first check valve 5 which shuts down a gap passage between an outer circumference at the tip of the inner rod and an inner circumference at the tip of the outer rod 2 and passes the flow of the ground reinforcing material from a base end to a tip is provided on an outer circumference at the tip of the inner rod. A nozzle to communicate a space being outside the inner rod and inside the outer rod 2 with the inner space of the inner rod is provided at the tip of the inner rod. A second check valve 7 to outward pass the ground reinforcing material from the inside of the inner rod is provided in the nozzle. The base end opening of the inner space of the inner rod is set up as one leading-in port if to the ground reinforcing material for improving the ground, and an opening in a space between an outer periphery at the base end of the inner rod and an inner periphery at the base end of the outer rod 2 is set up as another leading-in port 2b for the ground reinforcing material.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a main material such as cement milk and grout, which is a ground reinforcement material, and a main material such as cement milk, which is a ground reinforcement material, for hardening in a tunnel construction, an underground anchor construction and a foundation construction. The present invention relates to an apparatus for separately injecting a reactive material such as water glass.

[0002]

2. Description of the Related Art Conventionally, in tunnel construction, anchor construction, and foundation construction, in order to improve the weak ground,
A main material such as cement milk or grout and a reactive material such as water glass that reacts with the main material and hardens are injected as a ground reinforcing material. For injection of ground reinforcement, pipes
Drilling pipes are often used. Conventionally, the main material and the reaction material are mixed and injected at the position of the opening at the base end (ground side) of the pipe. Therefore, the main material and the reaction material react in the pipe and the interior of the pipe is filled with the solidified reinforcing material, which is difficult to reuse. In addition, there is a problem that the reinforcing material injected under strong pressure flows backward and is ejected to the ground side to contaminate the injection site.

[0003]

SUMMARY OF THE INVENTION The problems to be solved by the present invention are to solve these problems in the prior art, to suppress the backflow of the injected ground reinforcement, and to improve the ground reinforcement inside the rod for injection. It is an object of the present invention to provide a reusable ground reinforcement material injection device with less solidification.

[0004]

The structure of the present invention which has solved the above problems is as follows: 1) A cylindrical inner rod is inserted into a cylindrical outer rod to form a double pipe structure, and an outer peripheral surface in the middle of the outer rod is expanded. A first check valve for attaching a compressible packer, closing the gap passage between the outer circumference of the inner end of the inner rod and the inner circumference of the outer end of the outer rod, and passing the flow of the ground reinforcement from the base end to the end is provided at the end of the inner rod. Provided on the outer periphery, a nozzle is provided at the tip of the inner rod, which communicates with the space inside the outer rod outside the inner rod and the inner space of the inner rod.
The nozzle is provided with a second check valve for passing the ground reinforcement from the inside of the inner rod to the outside, and the base end opening of the inner space of the inner rod is used as an inlet for one of the ground reinforcement for ground improvement. Ground reinforcement material injection device in which the opening of the space between the outer circumference of the inner end of the inner rod and the inner circumference of the outer end of the outer rod is used as an inlet for other ground reinforcement materials 2) The first check valve is made of rubber, The ground reinforcement injection device according to 1), which has a structure in which a valve body extending in the outer tip direction in a skirt shape is projected from a cylindrical body portion fixed to the outer circumference of the inner rod tip. 3) First and second reverse The ground reinforcement injection device according to the above 1) or 2), wherein the tip portion of the inner rod to which the stop valve is attached is detachably attached to the inner rod body.

[0005]

In the present invention, the ground reinforcement material injection device having a double pipe structure of the outer rod and the inner rod is inserted into the ground drilling hole or the tubular buried pipe inserted into the drilling hole. After the insertion, gas or liquid is pumped to the packer for expansion, and the space between the outer rod outer periphery and the hole inner wall of the drilled hole or the inner surface of the buried pipe is closed. After that, one of the ground reinforcements is pressure-fed from the inlet of the base end opening of the inner rod. The ground reinforcement that has been pumped passes through the inner space of the inner rod, pushes open the second check valve at the lower end of the inner rod, and is discharged from the nozzle into the outer rod on the outer side. It is discharged into the ground in the drilled hole or into a buried pipe. The ground reinforcement discharged into the buried pipe moves to the tip inside,
It is injected from the tip opening into the ground of the drilled hole. Further, another ground reinforcing material is pressure-fed from the opening between the outer periphery of the inner rod at the base end of the injection pipe and the inner surface of the outer rod. This ground reinforcement is sent to the space between the outer circumference of the inner rod and the outer rod in the distal direction, and pushes the first check valve open by the pressure of the pressure feed to directly open the ground of the drilled hole from the opening at the lower end of the outer rod. Or discharge into the buried pipe. The ground reinforcing material that has flowed out into the buried pipe is poured out to the ground around the drilled hole from the tip opening of the buried pipe and the discharge hole of the ground reinforcing material in the middle. In this way, the two ground reinforcements are poured into the ground around the drilled hole, mixed to cause a chemical reaction, and harden to improve the ground. Even if the injected ground reinforcement material tries to rise inside the drilled hole / buried pipe, the packer that has expanded on the outer rod outer periphery blocks the space on the outer rod outer periphery, and the space between the inner rod outer periphery and the outer rod inner surface is the first space. The check valve works and shuts off, and the backflow into the inner rod is blocked by the work of the second check valve at the position of the nozzle so that they do not rise and jet. The one in which the check valve is composed of a rubber tubular portion and a skirt-shaped valve element is capable of reliably preventing backflow with a simple structure. Further, if the tip of the inner rod having the first and second check valves attached is detachable from the inner rod body, even if the two ground reinforcing materials are mixed and hardened by a chemical reaction, this inner rod It can be easily reused by replacing the tip.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In the embodiment shown in the drawings, the buried pipe is inserted into the hole,
It is an example in which the ground reinforcement injection device of the present invention is inserted therein. In addition, the packer of the embodiment is made of rubber that expands with air, the first and second check valves are made of rubber, and the first check valve extends from the tubular portion toward the outer tip in a skirt shape. The distal end portion of the inner rod having the above-mentioned valve body protruding and having the first and second check valves attached is detachably attached to the inner rod body. 1 is a partially cutaway front view of the embodiment, FIG. 2 is a vertical cross-sectional view of the embodiment, FIG. 3 is an enlarged vertical cross-sectional view of a tip portion of an injection pipe of the embodiment, and FIG. 4 is ground reinforcement of a buried pipe of the embodiment. Explanatory drawing showing the check valve of the material discharge hole, FIGS. 5 and 6 are explanatory views showing the operation of the first and second check valves of the embodiment, and FIGS. 7, 8 and 9 are ground improvement using the embodiment. It is explanatory drawing which shows the process of operation. In the figure, 1 is a long cylindrical inner rod,
1a is an inner rod body of the inner rod 1, 1b is a first connecting pipe screwed to the tip of the inner rod body, 1c is a second connecting pipe screwed to the first connecting pipe, and 1d is the same. A cap screwed to the tip of the second connecting pipe, 1e is a nozzle pierced in the peripheral wall of the cap, 1f is an inlet for water glass, which is a reaction material of the ground reinforcement at the base end of the inner rod 1, and 1g.
Is a passage inside the inner rod 1, 2 is a cylindrical outer rod, 2a is an opening at the tip of the outer rod 2, and 2b is a cement milk which is the main material of the ground reinforcement outside the opening 2a at the base end of the outer rod 2. Mouth 2c is outer rod 2
The cap at the base end of 2 is a fitting for the packer 4 provided around the outer rod 2, and 2e is an air inlet for the fitting 2d. In the figure, 3 is an injection pipe having a double pipe structure composed of an inner rod 1 and an outer rod 2, 4 is a rubber packer that is housed in a pair of upper and lower fittings 2d, and expands outward by air, and 5 is an inner rod. Second lower part of 1
A rubber first check valve mounted on the outer periphery of the connecting pipe 1c, 5
Reference character a denotes a tubular body portion of the first check valve, reference numeral 5b denotes a skirt-shaped valve body protruding from the tubular body portion 5a, and the tubular body portion 5a and the valve body 5b are integrally molded of rubber. . 6 is the first check valve 5
And a stop metal fitting for the second check valve 7, 7 is a second check valve made of rubber that is tubular and opens and closes the nozzle 1e, and 8 is a ground reinforcement pumping pipe connected to the inlet 1f of the inner rod 1. , 9 is a ground reinforcement pumping pipe connected to the inlet 2b of the outer rod 2,
Reference numeral 10 is an air pipe for sending air to the packer 4, 11 is a steel tubular buried pipe, 11a is a ground reinforcement discharge hole provided in the lower portion of the buried pipe 11, 11b is an opening at the tip of the buried pipe 11, and 12 is Ground, 13 is a hole drilling machine, 14 is a hole drilling machine, 15 is a mouth coating, 16 is a mixed ground reinforcing material, and 17 is a cap.

In this embodiment, the hole 13 is formed by the hole drilling machine 14 while burying the buried pipe 11 in the ground 12 (see FIG. 7A). The embedded pipe 11 is inserted into the drilled hole 13 (see FIG. 7B). Next, with the packer 4 contracted, the injection pipe 3 is inserted to the deepest part of the buried pipe 11 (see FIG. 7).
(C)). After inserting the injection pipe 3 into the buried pipe 11, high-pressure air is sent from the air pipe 10 to expand the packer 4 by air pressure so that the packer 4 expands outward from the folded state (FIG. 8).
(A)). The packer 4 expands and presses against the inner surface of the buried pipe 11, closing the passage 14 in the space between the outer circumference of the outer rod 2 and the inner surface of the buried pipe 11 to prevent the backflow of the ground reinforcement from the drilled hole 13. Then, the injection pipe 3 is fixed to the buried pipe 11 (see FIG. 8B). Next, water glass, which is a reaction material of the ground reinforcement 16, is pumped from the reinforcement pump 8, and cement milk, which is the main material of the ground reinforcement, is pumped from the other ground pump 9. Water glass as a reaction material is fed from the ground reinforcement material feed pipe 8 to the inlet 1f of the inner rod 1 and the rod body 1
a, the first connecting pipe 1b, the second connecting pipe 1c, and the cap 1d through the passage 1g, the nozzle 1e of the cap 1d pushes the second check valve 7 made of rubber to expand the inner rod 1
Is discharged to the space inside the outer rod 2 outside. Cement milk, the main material of the other ground reinforcement,
Ground reinforcement pumping pipe 9, inlet 2 at the upper end of outer rod 2
b and inside the outer rod 2, passing through the space between the inner rod 1 and the outer periphery of the inner rod 1, the skirt-shaped valve element 5b of the lower first check valve 5 is pushed down and opened to be discharged into the lower portion of the outer rod 2. While being mixed with water glass of the reaction material from the inner rod 1, the water is sent from the opening 2a at the tip of the outer rod 2 to the inside of the tip of the buried pipe 11, and the opening 11b at the tip of the buried pipe 11 and the ground reinforcement of the buried pipe 11. It is poured from the discharge hole 11a to the ground 12 of the drilled hole 13 (FIGS. 5 and 8 (b)).
reference). The two types of ground reinforcements 16, water glass as a reaction material and cement milk as a main material, are injected into the ground 12 while chemically reacting and hardened to improve the ground 12. The injection pipe 3 is inserted to the deepest part of the buried pipe 11 and then gradually pulled up while injecting the ground reinforcement material as described above (Fig. 8 (c),
(D), FIG. 9 (a), (b) reference).

When the hydraulic pressure or other fluid pressure in the hole drilling 13 in the ground is high, or when the ground reinforcement material fed under pressure is pressurized in the hole drilling 13, these fluids rise into the buried pipe 11. Although a reverse flow is about to occur, the valve body 5b of the first check valve 5 is expanded by the pressure in the space around the outer rod 2 as shown in FIG. 6, and the passage is closed. At the nozzle 1e of the inner rod 1, the second check valve 7 is also closed by the pressure of the fluid from the ground as shown in FIG. Furthermore, the space passage between the outer periphery of the outer rod 2 and the inner surface of the buried pipe 11 is closed by the packer 4. Thus, the pressure fluid from the ground 12 is
The first and second check valves 5, 7 and the packer 4 close the passage to prevent backflow. When used and solidified by the ground reinforcement material filled inside the tip of the injection pipe, the first or second connection pipe 1b, 1c or the cap 1
The inner rod body 1a and the outer rod 2 can be reused by removing d from the inner rod body 1a and replacing it with a new one, or by removing the ground reinforcing material adhering to the inner and outer peripheries.

[0009]

As described above, according to the present invention, backflow of water from the ground, ground reinforcing material for ground improvement, etc. can be prevented by the packer and the first and second check valves. The ground reinforcement can be injected into the ground so that there is no backflow. In addition, the solidified portion of the ground reinforcement material inside the injection pipe is small, and it can be reused and used for a long time.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of an embodiment.

FIG. 2 is a vertical sectional view of an example.

FIG. 3 is an enlarged vertical cross-sectional view of the tip portion of the injection pipe of the embodiment.

FIG. 4 is an explanatory view showing a check valve of a reinforcing material discharge hole of a buried pipe according to an embodiment.

FIG. 5 is an explanatory view showing the functions of the first and second check valves of the embodiment.

FIG. 6 is an explanatory diagram showing the operation of the first and second check valves of the embodiment.

FIG. 7 is an explanatory diagram showing a process of ground improvement work using an example.

FIG. 8 is an explanatory diagram showing a process of ground improvement work using an example.

FIG. 9 is an explanatory diagram showing a process of ground improvement work using an example.

[Explanation of symbols]

 1 Inner Rod 1a Inner Rod Main Body 1b First Connection Pipe 1c Second Connection Pipe 1d Cap 1e Nozzle 1f Inlet Port 1g Passage 2 Outer Rod 2a Opening 2b Inlet Port 2c Cap 2d Mounting Bracket 2e Air Inlet Port 3 Inlet Pipe 4 Packer 5 1st Check valve 5a Cylindrical part 5b Valve body 6 Stop fitting 7 Second check valve 8 Reinforcement pressure feed pipe 9 Reinforcement pressure feed pipe 10 Air pipe 11 Embedded pipe 11a Reinforcement discharge hole 11b Opening 12 Ground 13 Drilling hole 14 Drilling machine 15 Mouth coating 16 Ground reinforcement 17 Cap

Claims (3)

[Claims] 1. A tubular inner rod is inserted into a tubular outer rod to form a double pipe structure, an expandable and contractable packer is attached to an intermediate outer peripheral surface of the outer rod, and an inner rod tip outer periphery and an outer rod tip inner periphery are provided. A first check valve that closes the gap passage between the inner rod and the inner rod is provided on the outer periphery of the inner rod at the outer periphery of the inner rod, the first check valve closing the gap passage between A nozzle that communicates with the inner space of the inner rod is provided at the tip of the inner rod, and a second check valve that allows the ground reinforcement to pass outward from the inner rod is provided at the nozzle, and the base end of the inner space of the inner rod is provided. Ground reinforcement using the opening as one inlet for ground reinforcement for ground improvement, and the opening in the space between the outer periphery of the inner rod base end and the inner periphery of the outer rod base end as the inlet for other ground reinforcement Material injection device. 2. The first check valve is made of rubber, and has a structure in which a valve body extending in the outer tip direction in a skirt shape is projected from a cylindrical body portion fixed to the outer circumference of the tip of the inner rod. The ground reinforcement injection device described. 3. The ground reinforcement material injecting device according to claim 1, wherein the tip end portion of the inner rod to which the first and second check valves are attached is detachably attached to the inner rod body.