JPH094357A - Ground anchor executing method and device - Google Patents

Abstract

PURPOSE: To prevent the outflow of the grout injected into the ground, secure the anchor yield strength, and stably hold the ground. CONSTITUTION: The ground 1 is drilled by a drilling machine 7 fitted with a mouth packing 8 closing the gap between a guide tube 3 and a drill pipe 4 and fitted with a pinch valve 9 arranged with two bag-like valve elements 9b made of natural rubber and inflated when compressed air is pressed from the outside into the inner periphery of a tube 9 inserted with the drill pipe 4, and an anchor tensile member 6 is inserted. The drill pipe 4 is pulled up while a grout is pressed into the ground 1 from a swivel 11 connected to the upper end of the drill pipe 4. The joint of the drill pipe 4 is located between two valve elements 9b of the pinch valve 9, the compressed air is fed into the valve elements 9b to inflate them when the swivel 11 is connected to the drill pipe 4, and the drill pipe 4 is surely closed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a ground anchor construction method and a ground anchor construction method capable of preventing outflow of earth and sand and water and injected grout from the ground in construction of a ground anchor in a high water level or high pressure ground. For drilling machines and pinch valves.

[0002]

2. Description of the Related Art When placing a ground anchor near a river or a pond near a water surface, which is lower than the water surface, or ground under high pressure, conventionally, a drill pipe connected in multiple stages is used. After drilling, after injecting grout and inserting the anchor tension member in the drill pipe,
Furthermore, the construction method of forming the anchor body by removing the drill pipe while press-fitting the grout was performed. However, with this method, when the drill pipe is pulled out and collected after drilling, the high pressure applied to the ground by the previously injected grout and the soil / water in the ground causes it to flow backward in the drill pipe and open the drill pipe on the ground. It often became a problem because it was leaked from the. Although it is possible to supplement the looseness of the ground to some extent by supplementing the grout after collecting the drill pipe, deterioration of the strength of the grout and the ground is unavoidable, the anchor proof strength is lowered, and in terms of stable ground retention. The adverse effect was extremely large.
In addition, the spilled grout, sediment, and water were scattered around, making the work site dirty and difficult to work.

[0003]

The problem to be solved by the present invention is to solve the above-mentioned problems, prevent the outflow of grout, earth and sand and water, and do not reduce the strength of the ground and the injected grout. (EN) It is an object to provide a ground anchor construction method and a drilling machine or pinch valve used for the method, which secures anchor strength and enables stable ground holding.

[0004]

[Means for Solving the Problems] The constitution of the present invention which has solved the above problems is as follows: 1) A guide pipe is driven into the ground and connected in multiple stages to make it long, and a drill pipe with a bit attached to the tip is provided in the guide pipe. Ground, drilling the ground, inserting the anchor tension member into the drill pipe after drilling, then pulling out the drill pipe while press-fitting the grout to form the anchor body on the ground, ground anchor construction In the method, by closing the gap between the guide pipe inner circumference and the drill pipe outer circumference at the ground surface side opening of the guide pipe with the mouth packing, compressed air is externally injected into the inner circumference of the pipe having an inner diameter larger than the drill pipe outer diameter. Drill bag is inserted through the inside of a pinch valve with a structure in which two flexible bag-shaped valve bodies that expand and are separated by a predetermined distance in the axial direction of the pipe are installed. While pressing the grout from the swivel connected to the end into the drill pipe and sending it to the ground, the entire drill pipe is pulled up by one stage and the joint between the uppermost drill pipe and the next drill pipe has two pinch valves. The drill pipe at the uppermost stage is separated from the next stage so that it is located between the valve discs, and at the same time, the valve disc of the pinch valve is expanded to seal the upper end of the drill pipe at the next stage. From the swivel, connect the swivel to the upper end of the drill pipe that is sealed with a pinch valve, pull up the entire drill pipe by one step, disconnect the topmost drill pipe, and repeat these steps to repeat all drill pipe steps. The ground anchor construction method is characterized in that the ground is pulled up and an anchor body is formed in the ground. Insert a drill pipe with a bit attached at the tip into the ground along the guide rail to perform drilling, and at the drilling machine that can press grout through the drill pipe and pull out the drill pipe. A flexible bag that expands by pressurizing compressed air from the outside to the inner circumference of a pipe with an inner diameter larger than the outer diameter of the drill pipe at the tip of the guide rail of the drilling machine that supports the drill pipe immediately before the ground. Drilling machine characterized in that a pinch valve having a structure in which two valve bodies are provided in the axial direction of the pipe are separated by a predetermined distance so that the drill pipe penetrates. 3) Inner diameter larger than the outer diameter of the drill pipe The pinch valve is characterized in that two flexible bag-shaped valve bodies that expand by pressurizing compressed air from the outside into the inner circumference of the pipe are provided at predetermined intervals in the pipe axial direction. .

[0005]

In the ground anchor construction method of the present invention, while the grout is pressed into the ground through the drill pipe from the swivel connected to the uppermost end of the drill pipe, the entire drill pipe is pulled up by one step, and the uppermost drill pipe and the next step. Position the joint with the drill pipe in the middle of the two valve bodies of the pinch valve. Stop the grout press-in and disconnect the top-stage drill pipe from the next and subsequent stages, and at the same time expand the valve body of the pinch valve to seal the upper end of the next-stage drill pipe and prevent outflow of grout, water, and sediment. . While stopping the outflow with this pinch valve, remove the separated drill pipe from the swivel, lower the swivel position, and place it directly above the pinch valve. Then, the expansion of the pinch valve body is made a little smaller, and at the same time, the swivel is lowered and combined with the upper end of the drill pipe to ensure a reliable connection. When the swivel and the drill pipe are connected without any outflow, the grout press-in from the swivel is restarted, the valve body of the pinch valve is decompressed and returned, and the entire drill pipe is pulled up. By repeatedly pressing the grout, pulling up the drill pipe, and disconnecting the drill pipe in this manner, the drill pipe is pulled out to the ground to replace the press-fitted grout to form an anchor body on the ground.

[0006]

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view showing a ground anchor construction state of the embodiment, FIG. 2 is an explanatory view showing a main part of a hole drilling machine used in the embodiment,
FIG. 3 is an explanatory view showing a drilling work according to the embodiment, FIG. 4 is an explanatory view showing an anchor pulling member setting work according to the embodiment,
FIG. 5 is an explanatory view showing a drill pipe pulling up work according to the embodiment, FIG. 6 is a sectional view showing a pinch valve used in the embodiment, and FIG.
Is an explanatory view showing a drill pipe separating work according to the embodiment, FIG. 8 is an explanatory view showing a swivel moving state in the embodiment,
FIG. 9 is an explanatory view showing a connection state of the drill pipe and the swivel according to the embodiment.

In the ground anchor construction method of this embodiment, first, a guide pipe 3 for introducing a hole is driven from the surface of the ground 1 on which the structure 2 is installed. From the guide pipe 3, a drill pipe 4 having a bit 4a attached to the tip thereof is inserted by a drilling machine 7 to drill a hole in the ground 1. The hole drilling machine 7 is provided with a mouth packing 8 made of a triple rubber ring that watertightly closes the gap between the guide pipe 3 and the drill pipe 4, and a pipe having an inner diameter larger than the outer diameter of the drill pipe 4 is provided behind the mouth packing 8. A natural rubber is used which expands the inside of the pipe 9a by pressurizing compressed air from the external compressor 14 into the inner periphery of the pipe 9a to block the inside of the pipe 9a and to adhere to the outer periphery of the drill pipe 4 penetrating the inside of the pipe 9a. A pinch valve 9 having a structure in which two bag-shaped valve bodies 9b are arranged side by side in the pipe axis direction is detachably attached. The pinch valve 9 is mounted when the drill pipe 4 has drilled a predetermined length. After drilling and attaching pinch valve 9, drill pipe 4
A predetermined amount of grout 5 is injected in advance and the anchor tension member 6 is inserted. The anchor tension member 6 pushes the bit 4a at the tip of the drill pipe 4 to push the drill pipe 4
Drive in until it is completely removed. Unlike the drill pipe 4, the bit 4a may be left on the ground 1 as it is.

After the anchor pulling member 6 is set at a predetermined position in the ground 1, the drill pipe 4 is pulled out by the boring machine 7. This is because the grout 5 is press-fitted into the ground 1 through the drill pipe 4 from the swivel 11 connected to the uppermost end of the drill pipe 4 through the connection portion 11a.
The entire drill pipe 4 is raised by one stage of the drill pipe 4 by the rise of the drill driving device 12 along the guide rail 10 to replace the drill pipe 4 and the press-fitted grout 5, and at this time, the drill pipe at the top stage is replaced. Four
And the next-stage drill pipe 4 joint, the pinch valve 9
Of the drill pipe 4 so that it is located between the two valve bodies 9b of
Pull up. And grout 5 from swivel 11
Once the press-fitting is stopped and compressed air is sent to the pinch valve 9 from the external compressor 14 to expand the valve body 9b and disconnect the uppermost stage drill pipe 4 from the next stage onward, the two valves of the pinch valve 9 are separated. The body 9b closes the inside of the pipe 9a immediately before the opening of the next-stage drill pipe 4 and closely adheres to the outer periphery of the drill pipe 4 immediately after the opening to confine the grout 5 and earth and sand flowing back from the opening of the drill pipe 4, To prevent outflow (see FIG. 4). The separated drill pipe 4 is removed from the connecting portion 11a of the swivel 11, and the drill driving device 12 is lowered again so that the position of the swivel 11 is right above the pinch valve 9 (see FIG. 5). then,
Immediately before the opening of the drill pipe 4 at the uppermost stage due to the replacement, the pressure of the valve body 9b that closes the inside of the pipe 9a of the pinch valve 9 is slightly lowered to slightly weaken the adhesion, and at the same time, the connecting portion 11a of the swivel 11 is connected. Insert into tube 9a. Then, the connection portion 11a and the drill pipe 4 are connected while the valve body 9b is re-pressurized so as to prevent the grout 5 and the like from flowing out and the contact portion 11a and the outer periphery of the connection portion 11a are closely attached (see FIG. 6). In this way, when the swivel 11 and the drill pipe 4 are reconnected without leakage, the pressure of the valve body 9b of the pinch valve 9 is released to release it from the close contact state, and then the drill pipe 4 is pulled up again by one step and the grout 5 from the swivel 11 is released. Press-fitting is also resumed. After that, if the drill pipe 4 is pulled up, the grout 5 is press-fitted, and the drill pipe 4 is separated, the grout, the earth and sand, and the sand, sand and sand are removed while pulling the drill pipe 4 to the ground.
The anchor body can be formed without letting out water.

[0009]

EFFECTS OF THE INVENTION The present invention employs the above-mentioned method to prevent outflow of grout, earth and sand, and water from the ground, has a sufficient strength, and holds the ground stably. Can be easily constructed. In addition, the work site is easy to work without being spilled and polluted.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a ground anchor construction state of an embodiment.

FIG. 2 is an explanatory diagram showing a main part of a hole drilling machine used in the embodiment.

FIG. 3 is an explanatory view showing a drilling work according to an embodiment.

FIG. 4 is an explanatory diagram showing a work of setting an anchor tension member according to an embodiment.

FIG. 5 is an explanatory view showing a drill pipe pulling operation according to the embodiment.

FIG. 6 is a cross-sectional view showing a pinch valve used in an example.

FIG. 7 is an explanatory diagram showing a drill pipe separating operation according to the embodiment.

FIG. 8 is an explanatory diagram showing a swivel movement state in the embodiment.

FIG. 9 is an explanatory diagram showing a work of connecting a drill pipe and a swivel according to an embodiment.

[Explanation of symbols]

 1 ground 2 structure 3 guide pipe 4 drill pipe 4a bit 5 grout 6 anchor tension member 7 drilling machine 8 mouth packing 9 pinch valve 9a pipe 9b valve body 9c air pipe 10 guide rail 11 swivel 11a connection part 12 drill drive device 13 Base 14 Compressor

Claims (3)

[Claims] 1. A guide pipe is driven into the ground and is connected in multiple stages to make it long, and a drill pipe with a bit attached at the tip is inserted into the guide pipe to drill a hole in the ground. Insert the anchor tension member, then
In the ground anchor construction method, in which the drill pipe is removed while the grout is being press-fitted to form an anchor body in the ground, the gap between the guide pipe inner circumference and the drill pipe outer circumference at the ground surface side opening of the guide pipe is sealed with the mouth packing. A structure in which two flexible, bag-shaped valve bodies that expand when compressed air is pressed from the outside into the inner circumference of a pipe that is larger than the outside diameter of the pipe Insert the drill pipe inside the pinch valve of
While pressing the grout into the drill pipe from the swivel connected to the upper end of the drill pipe and sending it to the ground, the entire drill pipe is pulled up by one stage and the joint between the uppermost drill pipe and the next drill pipe is a pinch valve. It is located between the two valve bodies, and at the same time the uppermost stage drill pipe is separated from the next stage, at the same time the valve body of the pinch valve is inflated to seal the upper end of the next stage drill pipe and then separated. Remove the drill pipe from the swivel, connect the swivel to the upper end of the drill pipe that is sealed by the pinch valve, pull up the entire drill pipe by one step, disconnect the uppermost drill pipe, repeat these steps, and repeat the drill pipe. A method of constructing a ground anchor, which comprises pulling up all stages and forming an anchor body on the ground. 2. A multi-staged long pipe with a bit attached at the tip is inserted into the ground along a guide rail to make a hole, and grout is press-fitted through the drill pipe and the drill pipe. In a hole drilling machine capable of pulling out a pipe, the guide rail tip part of the hole drilling machine that supports the drill pipe to be inserted into the ground immediately before the ground, and compressed air from the outside to the inner circumference of the pipe with an inner diameter larger than the drill pipe outer diameter Characterized in that a pinch valve having a structure in which two flexible bag-shaped valve bodies that expand by press-fitting are separated from each other by a predetermined distance in the axial direction of the pipe is attached so that the drill pipe penetrates. , Drilling machine. 3. Two flexible bag-shaped valve bodies, which are expanded by pressurizing compressed air from the outside into the inner circumference of a pipe having an inner diameter larger than the outer diameter of the drill pipe, are separated by a predetermined distance in the axial direction of the pipe. A pinch valve characterized by being provided.