JPH0960464A - Hole bend correcting method in double pipe drilling and double pipe rod for it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly make a correction during drilling by advancing only an inner pipe in the hole bend correcting direction from the present drilling tip position while an outer pipe is stopped, and drilling a hole bend correcting guide hole in an undrilled area. SOLUTION: When a hole bend occurs during drilling, the intrusion and rotation of an outer pipe 1 is stopped, and only an inner pipe 2 is advanced deeper from the present drilling tip position. A hole bend correcting guide hole is drilled to the hole bend correcting direction in an undrilled area. The inner pipe 2 is stopped, the outer pipe 1 is advanced to the relative position to the inner pipe 2, then drilling is again conducted by a double pipe rod. The outer pipe 1 is naturally advanced along the correcting guide hole by the existence of the hole bend correcting guide hole at the front of the tip of the outer tube 1, and the hole bend is automatically corrected. The hole bend correction is made at any time during drilling, and the hole can be drilled with high execution accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention makes it possible to easily and quickly change the drilling direction during drilling while performing drilling with a double pipe rod without using a jig or device for correcting hole bending. TECHNICAL FIELD The present invention relates to a method for correcting hole bending in double-tube rod drilling, and a double-tube rod therefor.

[0002]

2. Description of the Related Art In anchoring work for stabilizing slopes and ground improvement work, drilling pipes such as single pipe rods and double pipe rods are successively added while drilling to a predetermined depth. Especially when drilling with a double pipe rod,
By rotating the inner tube and the outer tube in opposite directions, respectively, the rotational torque can be offset, and
It is often used for reasons such as good drilling accuracy because the overall rigidity of the rod itself increases.

The hole drilling by the double tube rod is carried out by the inner perforating method by the rotary percussion drilling method in the state of the double tube in which the inner tube is inserted into the outer tube. Bending may occur due to the unevenness of the holes and the characteristics of the hole drilling machine itself.

Conventionally, a relatively large number of proposals have been made as correction methods when hole bending occurs. For example, in Japanese Patent Publication No. 2-38303, when a hole is bent, a direction correction guide is inserted outside the drilling shaft and a taper portion provided on the inner surface of the direction correction guide is used for cutting. A method for advancing the drilling shaft and correcting the hole bending while directing the hole pipe axis in the opposite direction is disclosed.

[0005]

However, in the case of the above-mentioned conventional method, for example, an inclinometer in which the generated hole bending is provided in the rod is used, or JP-A-5-3215.
68, a detection method using a magnetic field,
Specifically, while using a drilling drill as an electromagnetic wave generation source, by utilizing the directional characteristics of the directional electromagnetic wave receiving element installed in the drilled hole, the method of detecting hole bending during drilling etc. If the bend is measured, a direction correction jig is inserted or the direction correction guide is replaced. Therefore, stop the drilling work once,
Since it is necessary to proceed with the drilling while taking time and effort to load / change the direction correcting guide, there is a problem that the drilling efficiency is reduced as a result.

Further, the hole bending in the rod drilling occurs at the tip of the rod.

If the drilling depth is shallow, it is possible to relatively easily correct the inclination of the drilling axis by inserting the direction correcting guide on the ground side. When the hole depth is deep, even if a force is applied to the rod in the direction of inclination correction on the ground, the rod itself will bend and the periphery of the rod will be constrained by the ground, which will cause it at the tip of the rod. Correcting hole bends is not easy.

Therefore, the main problem of the present invention is that when a hole bend is detected during drilling, a hole generated by the double pipe rod is drilled without using a jig or device for correcting the hole bend. It is an object of the present invention to provide a method for correcting a hole bend in a double pipe rod drilling capable of correcting a bend promptly and effectively, and a double pipe rod therefor.

[0009]

In order to solve the above-mentioned problems, the present invention stops the outer pipe if a hole bending occurs during drilling by a double pipe rod in which the inner pipe is inserted into the outer pipe. In this state, only the inner pipe is advanced in the hole bending correction direction from the current drilled hole tip position to form the hole bending correction guide hole in the undrilled area.

Therefore, if hole bending is detected by a hole bending detecting means such as a separately provided inclinometer, a hole bending correction guide hole is formed in the undrilled area as described above, and then doubled again. When drilling with a tube rod, the outer tube is guided along the hole bending correction guide hole and advances along this hole, so that the hole bending can be corrected easily and effectively at an early stage when the hole bending occurs. be able to. As a result, drilling can be performed with high construction accuracy.

Further, in the case of the present invention, since the hole bending is directly corrected by controlling the direction at the tip of the double pipe rod, it is basically effective regardless of whether the depth of the hole is shallow or deep. It is possible to correct the hole bending that has occurred in the.

Various forms are conceivable as a mechanism for piercing the inner pipe in the direction of correcting the bending of the hole, and a suitable example thereof is, for example, on the inner surface of the outer pipe on the tip side of the outer pipe. At the different positions in the longitudinal direction of the pipe and forming the upper-side convex portion and the lower-side convex portion on each side facing each other, at the tip side of the inner pipe, on the outer surface of the inner pipe, the upper-side convex portion corresponding position When a diameter-increasing portion having a substantially larger pipe outer diameter is formed in the upper region and the upper region corresponding to the lower convex portion, and the inner pipe is relatively advanced, the upper convex portion and the lower convex portion of the outer pipe are formed. By the contact between the convex portion and the increased diameter portion of the inner pipe,
The double tube rod can be configured such that the inner tube axis is inclined with respect to the outer tube axis at the rod tip portion.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a vertical sectional view of a double tube rod according to the present invention. The double pipe rod R includes an outer pipe 1 and an inner pipe 2.
As shown in the drawing, in the state where the inner pipe 2 is inserted into the outer pipe 1, as shown in the figure, the drilling is performed by turning the drilling water, the excavated earth and sand, etc. inward by the rotary percussion method. The relative positional relationship between the outer pipe 1 and the inner pipe 2 is the first mode in which the inner pipe 2 tip is located inside the outer pipe 1 tip, and the inner pipe 2 is drilled in the first mode. The second mode in which the drilling is performed while keeping the tip substantially at the same position and the third mode in which the drilling is performed with the tip of the inner tube 2 protruding outward of the tip of the outer tube 1 are conceivable. Can be applied to any of the above three perforations. Explaining below by the example of the first aspect, on the tip side of the outer tube 1 of the double tube rod R, on the inner surface of the outer tube 1, on the respective sides facing different positions in the tube longitudinal direction. Upper side convex portion 10
And the lower stage side convex part 11 is formed. The upper-side convex portion 10 and the lower-side convex portion 11 both have a triangular cross-sectional shape, and as shown in the transverse cross-sectional view of FIG. 3, the projecting height d is gradually reduced along the circumferential direction to face the facing side. And the protruding height is 0
Are continuously formed so that notches 10a, 10a ... Are formed at appropriate places in the circumferential direction, and a return water passage is secured. The cross-sectional shape of the convex portions 10 and 11 is not limited to the triangular shape, but various shapes such as a trapezoidal shape and an arc surface shape can be used. Further, unlike the above-described example, it is not necessary to form the protrusion height h continuously in the circumferential direction regardless of the difference in size. For example, as shown in FIG. 5, the protrusions 12 on the upper and lower sides are partially formed. May be formed.

On the other hand, on the distal end side of the inner pipe 2, on the outer surface of the inner pipe 2, an upper diameter increasing portion 20 having a substantially large pipe outer diameter in an upper region of a position corresponding to the upper step side convex portion 10, A lower diameter increasing portion 21 having a substantially larger pipe outer diameter is formed in an upper region corresponding to the lower convex portion 11. As shown in the cross-sectional view of FIG. 2, the increased diameter portions 20 and 21 are formed by providing a thick portion having a predetermined height h in the circumferential direction of the inner pipe 2.

Since it is sufficient for the diameter-increasing portions 20 and 21 to substantially increase the outer diameter of the inner pipe 2, as shown in FIG. 4, the inner pipe 2 has a trapezoidal cross section at appropriate intervals in the circumferential direction. It can also be formed by providing the ridges 22, 22, ... With a predetermined length in the tube axis direction. In this case, since the gap between the trapezoidal protrusions 22 and 22 serves as a return water passage, the upper and lower protrusions 10 formed on the outer pipe 1,
It is not necessary to provide the cutout 10a for the water passage at 11. Further, an inclinometer 3 for detecting a bent state of the rod R is provided inside the inner tube 2.

Therefore, when the inner tube 2 is relatively advanced while the outer tube 1 is fixed in position, as shown in FIG. 6, the upper convex portion 10 of the outer tube 1 and the upper part of the inner tube 2 are increased. Contact with the diametrical portion 20, and the lower convex portion 11 of the outer tube 1 and the inner tube 2
The inner pipe axis L is regulated by the contact with the lower diameter increasing portion 21, that is, the position of the inner pipe 2 is regulated at the A portion at the tip of the upper convex portion 10 and the B portion at the tip of the lower convex portion 11. _i is such that inclined at an inclination angle α with respect to the outer tube axis L _O.

When performing the perforation using the double pipe rod R, the perforation is performed while successively confirming the hole bending state by the inclinometer 3, and during the perforation, for example, inclining to the right side in the drawing in FIG. If hole bending occurs, first, the penetration and rotation of the outer tube 1 are stopped. Specifically, since the direction in which the rod R is advanced is to be corrected to the left side of the drawing, the lower convex portion 11 is on the right side of the drawing, and the upper convex portion 10 is on the left side of the drawing. The outer tube 1 is stopped.

Next, with the outer tube 1 stopped, the inner tube 2
Only the tip of the actual hole is pierced deeper than the position C. As described above, the inner pipe 2 is configured such that the increased diameter portions 20 and 21 formed on the inner pipe 2 ride on the upper-side convex portion 10 and the lower-side convex portion 11 of the outer pipe 1 to form an inner pipe shaft. Since the core l is inclined with the inclination angle α with respect to the outer tube axis L, as shown in FIG. 6, the hole bending correction in the undrilled area is performed in the hole bending correction direction (left tilt direction in the drawing). Guide hole F
Is formed. Then, the inner pipe 2 is stopped in the advanced state, the outer pipe 1 is advanced to a regular position relative to the inner pipe 2 shown in FIG. 1, and the double pipe rod is used for drilling again. . Alternatively, the inner pipe 2 may be temporarily returned to the original position shown in FIG. 1, and then the double pipe rod may be drilled again. When the hole bending correction guide hole F in the direction of the inclination angle α is present in front of the tip of the outer tube 1, the outer tube 1 naturally advances along the correction guide hole F, so that the generated hole bending is automatically corrected. It

By carrying out the drilling while performing such hole bending correction as needed, the drilled hole can be formed with high construction accuracy.

If there is a hole bending inclined to the left side of the drawing in FIG. 1, the outer tube 1 is stopped so that the lower-stage convex portion 11 is located on the left side of the drawing in FIG. Similarly, the inner tube 2 is pierced to form the hole bending correction guide hole F.

Further, in the case of the third mode in which the drilling is performed with the tip of the inner pipe 2 protruding outward of the tip of the outer pipe 1, the current drilled hole position is the inner pipe tip position. Similarly, the inner pipe 2 is further advanced from the current drilling hole tip end position to form the hole bending correction guide hole F in the undrilled region, and the drilling is performed while correcting the direction.

[0022]

As described above in detail, according to the present invention, there is no need to use any special jig or device for correcting hole bending.
It becomes possible to promptly and effectively correct the hole bending that has occurred while drilling with the double pipe rod.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view of a double tube rod according to the present invention.

FIG. 2 is a view taken along the line II-II of FIG.

FIG. 3 is a view taken along the line III-III in FIG.

FIG. 4 is a cross-sectional view showing another example of the shape of the inner pipe increased diameter portion.

FIG. 5 is a cross-sectional view showing another example of the shape of the convex portion of the outer tube.

FIG. 6 is an explanatory diagram of a hole bending correction procedure.

[Explanation of symbols]

1 ... Outer tube, 2 ... Inner tube, 3 ... Inclinometer, 10 ... Upper-side convex portion,
11 ... Lower side convex part, 20 ... Upper diameter increasing part, 21 ... Lower diameter increasing part, F ... Hole bending correction guide hole, R ... Double tube rod

Claims (4)

[Claims] 1. When a hole is bent during drilling by a double pipe rod in which the inner pipe is inserted into the outer pipe, only the inner pipe is bent from the current drilled hole tip position while the outer pipe is stopped. A hole bending correction method in double pipe rod drilling, characterized in that a hole bending correction guide hole is formed in an undrilled area by making a hole in the correction direction. 2. On the tip end side of the outer pipe, an upper-stage convex portion and a lower-stage convex portion are formed on the inner surface of the outer pipe at different positions in the longitudinal direction of the pipe and on opposite sides thereof. At the tip end side, on the outer surface of the inner pipe, a diameter-increasing portion having a substantially increased pipe outer diameter is formed in an upper region corresponding to the upper-side convex portion corresponding position and an upper region corresponding to the lower-stage convex portion corresponding position, When the inner tube is advanced to the upper tube side convex portion and the lower tube side convex portion of the outer tube, the inner tube axial center at the rod tip portion with respect to the outer tube axial center due to contact between the inner tube increased diameter portion. If the double pipe rod is configured to incline, and if hole bending occurs during drilling by the double pipe rod, only the inner pipe is drilled from the current drill hole tip position with the outer pipe stopped. It is special to form a hole bending correction guide hole in the undrilled area in the direction of the hole bending correction. Method for correcting hole bending in double pipe rod drilling. 3. After forming the hole bending correction guide hole,
3. The method for correcting hole bending in double pipe rod drilling according to claim 1, wherein the inner pipe is once returned to its original position and then the double pipe rod is used for drilling. 4. On the tip side of the outer pipe, an upper stage side convex portion and a lower stage side convex portion are formed on the inner surface of the outer pipe at different positions in the longitudinal direction of the pipe and facing each other. At the tip end side, on the outer surface of the inner pipe, a diameter-increasing portion having a substantially increased pipe outer diameter is formed in an upper region corresponding to the upper-side convex portion corresponding position and an upper region corresponding to the lower-stage convex portion corresponding position, When the inner tube is advanced to the upper tube side convex portion and the lower tube side convex portion of the outer tube, the inner tube axial center at the rod tip portion with respect to the outer tube axial center due to contact between the inner tube increased diameter portion. A double pipe rod characterized by being inclined.