JPH0593500A - Consoridation of self-drilled lock bolt and selt-drill lock bolt - Google Patents

Abstract

PURPOSE:To inject a chemical grout with good efficiency as well as easily drill holes by a method in which the intermediate hole of a lock bolt leading to the hollow is covered with a stopper, a pit is drilled, and the stopper is pushed out by a chemical grout under a fixed injecting pressure. CONSTITUTION:A hole leading to the hollow of a bolt (a) is formed in the intermediate part and the tip of a lock bolt (a), and the hole 3 is covered with a conical stopper for drilling. In this case, a water-mixed powder is injected into the hole 9 by compressed air or pressure water to form a form a hole by a bit 6. A chemical grout 10 is then injected through the tip hole of the bolt (a) into the hole 9 to push the inside of the hole 9 toward opening side in order. When the injecting pressure of the chemical grout is increased until its injecting pressure is reached to a fixed limit or more, the stopper of the intermediate hole 3 of the bolt (a) is pushed out by the chemical grout 10. The chemical grout 10 is also injected into the peripheral side of the bolt (a) even from the intermediate hole 3 to exactly fix the bolt (a) to the ground (b).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-drilling lock for a ground into which a consolidating chemical liquid (hereinafter, simply referred to as a chemical liquid) that is easy and quick-hardening is injected in tunnel excavation work. The present invention relates to a bolt consolidation method and its self-drilling rock bolt.

[0002]

2. Description of the Related Art If the ground is soft, or if the ground has cracks or joints that are significantly developed, the drill hole for the injection lock bolt cannot be self-standing and the drill rod cannot be pulled out. Often cannot be inserted. In such a case, a self-drilling lock bolt of a type that is drilled and buried as it is and used as an injection lock bolt is often used.

[0003] The conventional one uses a self-drilling lock bolt, is easy to work, and in the method of pouring a chemical solution to consolidate the self-drilling rock bolt to the ground, the hole for the injection is specified. It is provided only at the tip of the bolt as in the invention described in Japanese Laid-Open Patent Publication No. 48-47113, or at the tip and intermediate portion of the bolt as in the invention described in British Patent No. 790,483. ing.

[0004]

The problem to be solved is that, in the former case in which the injection hole is provided only at the tip of the bolt, compressed air or pressurized water is supplied into the hollow portion of the bolt for perforation. At the time of drilling, the compressed air or pressurized water may be blown out from the hole at the tip of the bolt to improve the discharge of the powder, but at the time of injecting the chemical through the hollow part of the bolt, the injected chemical may be It may not be possible to inject it around the bolt because it tends to collect toward the tip of the.

In the latter case in which the holes for injection are provided at the tip and the middle part of the bolt, compressed air or pressurized water is blown out from all the holes at the time of drilling, and the discharge of the powdered powder is poor, and a good result cannot be obtained. .. Furthermore, during the injection of the chemical liquid, the chemical liquid is injected first from the hole in the middle portion of the bolt and is difficult to be injected from the hole at the tip,
There is a case where the injected chemical solution is easily collected in the middle part of the bolt and cannot be injected around the bolt.

On the other hand, the purpose of injecting the chemical liquid of the lock bolt is
Since the chemical solution is injected around the bolts, both of the above cannot achieve the expected effect of bolt consolidation.

[0007]

Generally, the supply pressure of compressed air or pressurized water during drilling with a lock bolt is 3
~ 7 kg / cm ² . On the other hand, the injection pressure at the time of injecting the chemical solution is 15 to 100 kg / cm ² at the maximum.
become. Therefore, if this pressure difference is utilized, only the hole at the tip of the bolt is opened during drilling with the lock bolt, and the hole in the middle part of the bolt is opened during injection of the chemical liquid, and the chemical liquid is injected from that hole as well. A solidification method for drilling rock bolts is possible.

According to the present invention, in order to facilitate the drilling work with the self-drilling lock bolt and to properly inject the chemical liquid into the periphery of the bolt, the tip and the intermediate portion of the self-drilling lock bolt communicate with the hollow portion in the bolt. Hole is provided, and a cone-shaped stopper is placed in the hole in the middle of the hole, and when the chemical liquid is injected after the self-drilling lock bolt is used, the chemical liquid is first injected through the hole at the tip of the bolt. When the pressure exceeds a certain limit, the chemical solution extrudes the stopper of the hole in the intermediate portion, and the chemical solution is also injected from the hole. Further, the purpose of facilitating the drilling work and well injecting the chemical liquid around the bolt is realized by a simple configuration.

[0009]

1 to 5 show one embodiment of the present invention,
The structure will be described with reference to the drawings. (A) shows a self-drilling lock bolt, (1) and (1) are hollow full screw bolts to be connected, and one or a plurality of intermediate portions of the bolt (1). A hole (3) communicating with the hollow portion (2) is provided at a position, and the bolts (1) and (1) have their connection side end portions on both side female screw portions (5) and (5) of the coupler (4), respectively. The end faces of the connection side are screwed together and pressed against each other for connection.

(6) is a bit of the lock bolt (a),
The bit (6) is provided with a hole (7) communicating with the hollow portion (2) of the bolt (1) by being screwed to the tip of one bolt (1). (8) is a stopper installed in the hole (3) in the middle part of the bolt (1), which is removed by hitting the rock bolt (a) or rotating the lock bolt (a) during drilling with the lock bolt (a). It is made of a material that is flexible and capable of absorbing impact, such as rubber, plastic, and wood. The size of the stopper (8) is such that the stopper (8) is extruded from the hole (3) by the chemical liquid (10) when the injection pressure reaches a certain limit when the chemical liquid is injected, for example, 20 kg / cm ² or more. Is set, and as shown in FIG. 3, it is embedded and pressed into the hole (3).

(B) shows the ground, (9) shows the ground (b)
Perforated with lock bolt (a), (10) is a chemical solution,
(11) is a washer, (12) is a lock bolt tightening nut, and (13) is an exhaust tube inserted through a through hole of the washer (11).

The operation will be described. Lock bolt (a)
When compressed air or pressured water is supplied into the hollow portion (2) of the rock bolt and the rock bolt (a) is used to pierce the natural ground (b), the compressed air or pressured water causes the hole (7 ), The powder is discharged from the hole by the compressed air or the pressure water, and the bit (6) is used for the hole drilling.

As shown in FIG. 1, after the hole (9) is drilled to the required depth by the lock bolt (a), the chemical solution (10) is injected through the hollow portion (2) of the lock bolt (a).
While the air in the perforation (9) is discharged from the exhaust tube (13), the chemical liquid (10) is first injected into the inner part of the perforation (9) through the hole (7) at the tip of the lock bolt (a) and the perforation ( 9) The inside is sequentially pushed toward the opening side. When the above-mentioned action progresses and the injection pressure of the chemical solution (10) increases and the injection pressure exceeds a certain limit, the chemical solution (10) causes the stopper (8) of the hole (3) in the middle portion of the lock bolt (a). Is extruded, and the chemical solution (10) is also injected from the hole (3) to perform the chemical solution injection action.

[0014] Figures 6 and 7 show a second embodiment of the plug (8), the configuration of the plug _(81), said plug (8) push rod or the like in the central portion of the large diameter side end face of Recess for insertion of (14)
Is provided with a pressure receiving recess (15) at the center of the end surface on the small diameter side.

[0015] FIGS. 8 and 9 show a third embodiment of the plug (8), construction of the plug _(82), the locking bolt (a) of the hole (3) to push easy way the plug A part of the small diameter side of (8) is formed into a steep taper (16). Further, both end surfaces of this stopper (8 ₂ ) may be provided with a recess (14) for insertion of a push rod or the like and a recess (15) for pressure reception as in the case of the stopper (8 ₁ ).

The stoppers (8 ₁ ) and (8 ₂ ) also operate in the same manner as the stopper (8).

[0017]

Industrial Applicability The self-drilling lock bolt consolidating method and the self-drilling rock bolt of the present invention have the following advantages.

(1) Since the hole in the middle portion of the lock bolt is plugged so as to be extruded when the injection pressure of the chemical liquid exceeds a certain limit, at the time of drilling with the lock bolt, Since the compressed air or compressed water supplied to the hollow part has a weak supply pressure, it is perforated while being blown out only from the hole at the tip of the bolt, and the dust is well discharged, and the boring work can be performed smoothly and quickly. And workability is good.

(2) At the time of injecting the chemical liquid, the chemical liquid passes through the hollow portion of the lock bolt and is first injected from the hole at the tip of the bolt toward the deep part of the perforation. After that, when the injection pressure of the chemical liquid exceeds a certain limit, The plug of the hole in the middle part of the bolt is pushed out by the chemical liquid, and the chemical liquid is injected also from the hole, and the chemical liquid is injected quickly and accurately, and the lock bolt is surely solidified to the ground, which is practically useful. ..

(3) The structure is simple, the construction is easy, and the operation is appropriate.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a state in which a self-drilling lock bolt according to an embodiment of the present invention is installed.

FIG. 2 is an enlarged front view of the same self-drilling lock bolt, showing the intermediate portions on both sides by cutting away.

FIG. 3 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 4 is a side view of the stopper.

FIG. 5 is a rear view of the same.

FIG. 6 is a side view of the second embodiment of the stopper.

FIG. 7 is a rear view of the same.

FIG. 8 is a side view of the third embodiment of the stopper.

FIG. 9 is a rear view of the same.

[Explanation of symbols]

 a Self-drilling rock bolt b Ground rock 1 Hollow full screw bolt 2 Hollow part 3 Hole 4 Coupler 5 Female screw part 6 Bit 7 Hole 8 Plug 9 Drilling 10 Consolidation liquid 11 Washer 12 Lock bolt tightening nut 13 Exhaust tube

Claims (2)

[Claims] 1. A self-drilling lock bolt is provided with a hole communicating with a hollow portion in the tip and an intermediate portion thereof, and a cone-shaped plug is press-fitted into the hole of the intermediate portion, and compressed air or pressurized water is added to the above. The bolt is blown into the hollow part of the bolt and blown out only from the hole at the tip of the bolt to be perforated by the bolt.Next, the consolidating chemical solution is passed through the hollow part of the bolt and first injected from the hole at the tip of the bolt. A method for consolidating self-drilling rock bolts, characterized in that when the chemical liquid exceeds a certain limit, the stopper of the hole in the intermediate portion is extruded by the chemical liquid and the chemical liquid is injected also through the hole. 2. A bit having a hole communicating with the hollow portion inside the bolt is screwed into the tip portion of the hollow full screw bolt, and a hole communicating with the hollow portion inside the bolt is provided in the middle portion of the bolt. , In the hole of the intermediate part, a cone-shaped plug is embedded under pressure so that when the injection pressure of the consolidating chemical liquid injected through the intermediate part of the bolt becomes a certain limit or more, it is extruded by the chemical liquid. Self-drilling rock bolt characterized by.