JPH10212893A - Earth removal method in method of bedrock drilling construction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the removed earth clogging of a drilling device having double pipe structure by smoothly removing earth. SOLUTION: A drilling device has the inner pipe 10 and outer pipe 12 of double pipe structure. The outer pipe 12 has an inside diameter larger than the outside diameter of the inner pipe, and an earth removing path is formed between these pipes 10, 12 when the inner pipe 10 is inserted on a concentricity in the outer pipe 12. One end side of the earth removing path is opened to the outside at the front end section of the outer pipe 12. A double rotary 20 rotating and driving the outer pipe 12 and an earth removing swivel 22 being communicated with the earth removing path and extracting removed earth D to the outside are arranged on the rear end side of the outer pipe 12. A discharge opening 24 communicated with the inside is formed to the outer circumference of the earth removing swivel 22, and an earth removing hose 26 is connected to the discharge opening 24. The connecting section of the earth removing hose 26 is branched into a Y shape, and high-pressure air E is injected towards the downstream side of the earth removing hose 26 from the branch pipe 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earth removal method in a ground drilling method and, more particularly, to a technique for smoothly discharging an earth in this kind of method.

[0002]

2. Description of the Related Art Rock bolt method and high-pressure jet stirring method are known as methods used for improving soft ground and collapsible ground, and the ground is drilled by this kind of method. In some cases, a drilling device having a double pipe structure is used in order to prevent collapse of the drilling. In the drilling method using a drilling device having such a structure, when drilling a ground, supplying drilling water to cool the drilling bit, including earth and sand excavated by the drilling bit. The earth removal is discharged outside the borehole.

[0003] Drilling water is usually supplied from the inside of an inner pipe in order to prevent collapse of the ground, and soil is discharged to the outside through a soil discharging passage provided between the inner and outer pipes. Was. In this case, in the method in which the inner and outer pipes are driven to rotate, a discharging swivel communicating with the discharging passage is attached to a portion where the outer pipe protrudes from the ground, without obstructing the rotational driving of the drilling device. The removal of soil was performed smoothly.

[0004] However, such a conventional earth discharging method has the following technical problems.

[0005]

That is, in the conventional drilling method, the earth removal passes through an earth removal passage provided between the inner pipe and the outer pipe, and then is passed through the earth removal swivel. However, since the excavated soil contains excavated earth and sand, it is particularly easy to clog in the vicinity of the discharge port of the excavated swivel.

[0006] When such clogging occurs in the earth removal, the resistance of the inner pipe that is driven to rotate increases, causing problems such as impairing the smoothness of drilling.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and an object of the present invention is to eliminate the inconvenience associated with clogging of soil by smoothly discharging the soil. It is an object of the present invention to provide a soil removal method in the ground drilling method that can perform the drilling.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a two-piece type comprising: an inner pipe provided with a drill bit on the distal end side; and an outer pipe containing the inner pipe therein. In a method of drilling a ground using a drilling device having a heavy pipe structure, high-pressure air is supplied to a downstream side in the vicinity of a discharge port communicating with a soil discharging passage provided between the inner pipe and the outer pipe. Was spouted. According to the discharging method configured as described above, the high-pressure air is blown toward the downstream side in the vicinity of the discharge port communicating with the discharging path provided between the inner pipe and the outer pipe. When the high-pressure air is injected, a negative pressure acts on the upstream side (inner and outer pipes) of the jetting point, and the negative pressure also promotes the soil removal. As a result, In addition, clogging of the soil can be effectively prevented. The discharge port may be mounted on a portion of the outer pipe protruding from the ground, and may be provided on a discharging swivel communicating with the discharging passage. According to this configuration, even in a drilling device that rotationally drives the inner and outer pipes, it is possible to prevent clogging of the earth. The discharge port may be attached to a portion of the outer pipe protruding from the ground, and may be provided in a discharge cap communicating with the discharge passage. According to this configuration, even in a drilling device that does not rotationally drive the outer pipe, it is possible to prevent clogging of the earth.

[0009]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG.
FIG. 3 to FIG. 3 show a first embodiment of the earth removal method in the ground drilling method according to the present invention, and the examples shown in these figures are cases where the present invention is applied to the high-pressure jet stirring method. FIG. 1 shows the construction steps of the high-pressure injection stirring method in order.

In the high-pressure injection stirring method shown in FIG. 1, when excavating and forming a cavity such as a tunnel, prior to excavation,
The basic configuration is to form a columnar pile A extending in the excavation direction from the face side along the periphery of the excavation section in the ground B.

When forming the cylindrical pile A, FIG.
The drilling device shown in FIG. 3 is used. The drilling device shown in these figures is supported by a boom (not shown) and includes an inner pipe 10 and an outer pipe 12 having a double pipe structure.

The inner tube 10 has a cylindrical inner tube main body 10a open at both ends, and is fixedly mounted at the tip of the inner tube main body 10a.
It has a cylindrical injection adapter 10b disposed at a position protruding forward from the outer tube 12, and a drill bit 10c fixed to the tip of the injection adapter 10b.

The injection adapter 10b includes a main body 101 having a through hole 100b communicating with the inside of the inner tube main body 10a.
b, and a plurality of injection nozzles 102b mounted in through holes provided in the radial direction of the main body 101b.

The injection nozzles 102b are arranged at predetermined intervals along the axial direction of the main body 101b, and are arranged one at a time in the circumferential direction.
An interval of 80 degrees is provided. The drill bit 10c is
The injection adapter 1 has a reamer bit 100c provided on the outer periphery of the distal end of the main body 101b of the injection adapter 10b and a pilot bit 101c disposed at the forefront.
The injection nozzle 10 is inserted into a hole communicating with the through hole 100b of the nozzle 0b.
2c is mounted.

As shown in FIG. 3, a double rotary 14 for rotating the inner tube body 10a and a high-pressure swivel 16 for supplying a hardening material C into the inner tube body 10a are provided at the rear end side of the inner tube body 10a. Is arranged.

On the other hand, the outer tube 12 has an inner diameter larger than the outer diameter of the inner tube main body 10a, and has a cylindrical outer tube main body 12a whose both ends are open. When the pipe main body 10a is inserted concentrically, the earth discharging passage 1 surrounded by the inner peripheral surface of the outer pipe main body 12a and the outer peripheral surface of the inner pipe main body 10a.
8 are formed.

One end of the earth discharging passage 18 is connected to the outer pipe main body 1.
It is open to the outside at the tip of 2a. In addition, the outer tube body 1
A ring bit 12b is fixedly provided on the outer periphery of the tip of 2a.

At the rear end side of the outer tube body 12a, the outer tube body 1 is provided.
2a, which is in communication with a double rotary 20 for rotating and driving the earth discharging passage 18, and which takes out the earth discharging D to the outside.
2 are arranged.

A discharge port 24 communicating with the inside is provided on the outer periphery of the discharge swivel 22, and a discharge hose 26 is connected to the discharge port 24. Discharge hose 26
Is branched in a Y-shape, and high-pressure air E is jetted from the branch pipe 28 toward the downstream side of the discharging hose 26.

When a columnar pile A is formed in the ground B by using the drilling device having the above-described configuration, as shown in FIG. The inner and outer pipe bodies 10a, 12a are drilled in the drilled portions while the pipe body 12a is rotationally driven by the double rotary 14, 20 and the ground B is drilled forward with the drill bit 10c and the ring bit 12b. Inserted.

At this time, in the case of the present embodiment, the hardening material C, for example, cement molk or cement paste is supplied into the inner pipe main body 10a via the high-pressure swivel 16, and is injected by the supply pressure of the hardening material C. Adapter 10b and drill bit 1
The hardening material C is sprayed from the spray nozzles 102b and 102c provided at 0c toward the ground B at the front and side.

The hardening material C injected from the injection nozzles 102b and 102c cuts the surrounding ground B,
It diffuses and penetrates a wide area in front and side of the ground B. In this case, since the inner pipe main body 10a is driven to rotate, the injection direction of the injection nozzle 102b also moves in the circumferential direction, and as a result, the range of diffusion and penetration of the hardening material C becomes cylindrical.

At this time, the earth removal D caused by the advance drilling of the hole drilling bit 10c and the ring bit 12b is transferred to the earth discharging passage 18
Is taken in from one end side of the
Through 4, it is guided to a discharging hose 26.

In this case, since the discharged hardening material D contains the injected hardening material C, if it stagnates in the discharge passage 18 or the like, the hardening material C is included, so that it is easily clogged. Therefore,
In the present embodiment, high-pressure air E is ejected through a branch pipe 28 toward the downstream side of the discharging hose 26 near the discharge port 24 of the discharging passage 18.

When the high-pressure air E is ejected in this way, the earth removal is promoted by the high-pressure air E, and when the high-pressure air E is ejected, the high-pressure air E is ejected upstream of the injection point,
Since a negative pressure acts on the earth discharging passage 18 and the earth discharging swivel 22 side between the inner and outer pipes 10a and 12a, the earth discharging is also promoted by this negative pressure, and as a result, the clogging of the earth discharging D is effectively prevented. Can be prevented.

As described above, when the inner and outer pipes 10 and 12 are inserted into the ground B to a predetermined length, the inner pipe 10 is extracted. Inner tube 1
When extracting 0, the double rotary 20 and the earth removal swivel 22 attached to the outer tube 12 are removed, and only the outer tube 12 is left.

When the hardening material C injected into the ground B hardens, a columnar pile A integrated with the outer periphery of the outer tube 12 is formed.

According to the earth removal method configured as described above, the earth removal clogging can be prevented even in the hole drilling device that rotationally drives the inner and outer pipes 10 and 12, and the drilling work can be efficiently performed. Can do well.

FIG. 4 shows a second embodiment of the earth discharging method according to the present invention. The same or corresponding parts as in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Only the characteristic points will be described.

The embodiment shown in the figure is a case where the present invention is applied to the rock bolt method, and the drilling device is an inner pipe 5.
The inner tube 50 is driven by rotation only, and a drill bit (not shown) is provided at the distal end of the inner tube 50. .

This drill bit is disclosed in, for example,
No. 465, which has a structure capable of drilling a hole slightly larger than the diameter of the outer tube 52 and capable of shrinking to fit inside the inner tube 50 when the inner tube 50 is extracted. Is desirable.

The inner pipe 50 has a hollow pipe shape, and the inside thereof is a supply passage 54 for drilling water F.
The drilling water F is supplied for cooling the drilling bit. The drilling water F is supplied to the supply passage 54 at the rear end side of the inner pipe 50 according to the above-described embodiment. A high-pressure swivel (not shown) having a similar structure and a double rotary (not shown) for driving the inner tube 50 to rotate are provided.

At the end of the outer pipe 52 projecting from the ground B to the outside, a discharging cap 56 is mounted in place of the discharging swivel 20. The earth discharging cap 56 has substantially the same diameter as the outer tube 52, and one end is fixed to an edge of the outer tube 52 via a mounting flange, and the other end is
The inner ring 50 is fitted around the outer periphery of the inner tube 50 with a seal ring 58 interposed therebetween.

An earth discharging port 60 communicating with the inside is provided on the outer periphery of the earth discharging cap 56, and the earth discharging hose 26 having the branch pipe 28 for jetting the high pressure air E is provided at the earth discharging port 60. It is connected. When drilling the ground B, drilling water F is supplied through the supply passage 54, and the earth removal D accompanying the drilling is carried out between the inner pipe 50 and the outer pipe 52 as in the above embodiment. The air is taken in through the earth discharging passage 18 and flows down the earth discharging passage 18 to reach the inside of the earth discharging cap 56. Thereafter, the earth discharging D in the earth discharging cap 56 is discharged from the discharging port 60 to the earth discharging hose 26 side.
The high-pressure air E is injected from the nozzle, so that clogging of the earth is prevented as in the first embodiment, and the drilling efficiency can be improved even when a drilling device that does not rotate the outer pipe 52 is used.

[0035]

As described above in detail in the embodiments,
According to the earth removal method in the ground drilling method according to the present invention, clogging of the earth removal is eliminated, so that inconvenience in construction due to the earth removal clogging can be avoided, and the drilling efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing a construction step of a high-pressure jet stirring method to which a soil discharging method according to the present invention is applied.

FIG. 2 is an explanatory view of a main part of a drilling device used in the method of FIG.

FIG. 3 is a sectional view of a main part of a drilling device used in the method of FIG. 1;

FIG. 4 is an explanatory sectional view of a main part showing another embodiment of the earth discharging method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Inner pipe 10a Inner pipe main body 10b Injection adapter 102b Injection nozzle 10c Drilling bit 102c Injection nozzle 12 Outer pipe 14 Double rotary 16 High pressure swivel 18 Discharge passage 22 Discharge swivel 24 Discharge port 26 Discharge hose 28 Branch pipe A Column shape Pile B Ground Mountain C Hardening Material D Discharge E High-Pressure Air F Drilling Water

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tsuyoshi Fujii 2-3 Kandajimachi, Chiyoda-ku, Tokyo Tokyo Main Office in Tokyo (72) Inventor Tadashi Ninomiya 2-3 Kandajimachi, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo head office

Claims (3)

[Claims] 1. A ground drilling method using a double-pipe drilling device including an inner pipe having a drill bit on the tip end side and an outer pipe for housing the inner pipe therein. In the construction method, a high-pressure air is blown toward a downstream side in the vicinity of a discharge port communicating with a discharge path provided between the inner pipe and the outer pipe, and the earth removal method in the ground drilling method. Method. 2. The ground according to claim 1, wherein the discharge port is mounted on a portion of the outer pipe protruding from the ground, and is provided on a discharge swivel communicating with the discharge passage. Earth removal method in mountain drilling method. 3. The ground according to claim 1, wherein the discharge port is mounted on a portion of the outer pipe protruding from the ground, and is provided in a discharge cap communicating with the discharge passage. Earth removal method in mountain drilling method.