JPH06173578A - Method for strengthening ground - Google Patents

Abstract

PURPOSE:To make it possible to form a reinforced wall which continues to a ground by a method wherein a steel tube acts as a supporting and strengthening material can be easily injected and the injected reinforcing material is prevented from leaking out. CONSTITUTION:A drilling member provided with a bit on its end is releasably inserted into a steel tube wherein the opposite ends thereof are opened and a plurality of through holes 6 are provided on the outer periphery thereof and an external thread is formed on the rear end thereof, and the steel tube 4 is forced into a ground while the drilling member bores a hole through the ground, whereupon the drilling member is pulled out of the steel tube. By means of an injection pump 24 connected to the steel tube through an injection plug 23 which is engaged with the thread 5, strengthening material is forced into the steel tube to inject the material into the ground from the end opening of the tube and through holes 6, following which the plug 23 is removed from the tube and a washer is fitted into the tube in place of the plug and a cap nut is threadedly engaged with the thread 5 so that the gap between the outer periphery and the ground is sealed by the washer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for strengthening natural ground such as tunnels.

[0002]

2. Description of the Related Art Conventionally, for example, as a method of strengthening the ground of a tunnel, a plurality of supports arranged parallel to the tunnel excavation direction have been installed on the outer supports of the tunnel excavation cross section along the contour of the tunnel. A method of press-fitting a steel pipe and forming a roof similar to the excavated surface by the steel pipe is known. By the way, in the conventional construction method as described above, the steel pipe only acts as a supporting work, the tunnel ground is not strengthened, and it is difficult to effectively prevent loosening or subsidence of the ground. In addition, when there is bedrock in the ground, there is a problem that the steel pipe cannot be press-fitted to strengthen the same part.

[0003]

As a method for solving such a problem, there is a method disclosed in Japanese Patent Publication No. 3-48314 proposed by the applicant earlier, which is Since there is some commonality with the illustrated embodiment of the invention, description will be made with reference to this. According to this method, a steel pipe 4 having a plurality of through holes 6 opened at both ends and having a bit attached to the tip inside thereof is removably arranged in the ground 2 by the piercing means 8. After press-fitting while punching, the punching means 8 is withdrawn from the steel pipe 4 after completion of press-fitting for a predetermined length, and the reinforcing material is press-fitted into the plurality of steel pipes 4 thus press-fitted into the ground 2, The reinforcing material is injected into the ground 2 through the tip opening and the through hole 6 on the outer periphery to form the continuous reinforcing wall portion 3, and the intended purpose can be achieved. However, in such a method, when the reinforcing material is press-fitted into the steel pipe, the operation is troublesome, and it is difficult to press it in properly, and the reinforcing material that has been press-fitted passes between the ground and the steel pipe. There is a problem that it leaks to the outside.

Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional construction method, to allow the steel pipe to act as a supporting work, and to form a continuous reinforcing wall portion in the ground. In addition, when press-fitting the reinforcing material during its formation,
It provides a method for strengthening natural rock that is easy to operate for that purpose, can be press-fitted in an efficient manner, and that the strengthened material that has been press-fitted does not leak to the outside through between the rock and the steel pipe. It is in.

[0005]

In order to achieve the above-mentioned object, the invention of claim 1 has a plurality of through holes on the outer circumference with both ends opened, and the outer circumference of the rear end. A drilling means having a bit attached to the tip is removably inserted into a steel pipe having a female thread, and the steel pipe is press-fitted into the ground while punching the ground by the drilling means, and a predetermined length of press-fitting is performed. Then, the perforating means was pulled out from the steel pipe, and injection plugs were screwed to the male threads of the rear ends of the plurality of steel pipes press-fitted into the ground in this way, and the injection pipes were connected to the steel pipe. The injection pump pumps the reinforcement into the steel pipe,
The reinforcing material is injected into the ground through the opening at the tip of the steel pipe and the through hole on the outer periphery, and the injection plug is removed from the steel pipe after finishing the injection of the reinforcing material in this way. 3. A cap nut is screwed to the male threaded portion to seal a gap between the outer circumference and the ground with a washer, thereby forming a continuous reinforcing wall portion in the ground. In the invention of claim 1, in the invention of claim 1, a female screw portion that can be screwed into the male screw portion is provided inside the front end of the steel pipe, and if necessary, both screw portions are screwed together to form a plurality of steel pipes. Connect and perform long processing.

[0006]

In the invention of claim 1 as described above, a part of the piercing means is removably disposed in the steel pipe, and the piercing means is operated to pierce the ground by the bit at the tip of the piercing means. The steel pipe is press-fitted into the mountain, and the punching means is pulled out from the steel pipe when press-fitted for a predetermined length, and the injection plug is screwed to the rear end male screw portion of the plurality of steel pipes thus press-fitted into the ground, The reinforcement is pressed into the steel pipe by the injection pump connected to the steel pipe through this injection plug, and the reinforcement is injected into the ground through the tip opening of the steel pipe and the through hole in the outer periphery. After the injection is completed, remove the injection plug from the steel pipe, replace the steel pipe with a washer, screw a cap nut to the male thread of the steel pipe, and seal the gap between the outer circumference and the ground with a washer. A continuous strengthening wall is formed in the ground. Next, in the invention of claim 2, when a long process is required, a plurality of steel pipes are connected by screwing a female screw portion of the leading end of the trailing steel pipe into a male screw portion of the trailing end of the preceding steel pipe. Will be done.

[0007]

1 is a block diagram of an embodiment of the present invention shown in the drawings.
Shows a cross section of the strengthening wall portion 3 in the ground 2 of the tunnel 1 strengthened by the construction method of the present invention, and 4 represents a steel pipe. 2 to 4 show a piercing means 8 used in this construction method. The steel pipe 4 has a plurality of through holes 6 opened at both ends and a female thread portion 9 at the front end and a rear portion. A male screw portion 5 that can be screwed into the female screw portion 9 is provided at the end. The piercing means 8 is constructed in the same manner as the conventional one, and the first bit 18 fixed to the tip of the bit body 7 provided at the tip,
A second bit 19 that can be opened and closed, and is attached to the tip of a drilling rod 14 that is joined to a shank rod 12 attached to a rock drilling machine 11 via a coupling sleeve 13, and the front side of the coupling sleeve 13 A pipe holder 17 is attached via a holder cap 16 to which the steel pipe 4 is fitted.

When drilling with the above-mentioned steel pipe 4 in which a part of the drilling means 8 is removably arranged,
The drilling machine 11 is operated to rotate the drilling rod 14 while applying thrust to the drilling rod 14, and the first bit 18 of the bit main body 7 which rotates in association with the drilling is used to excavate the second drilling bit 14. Depending on the diameter of the steel pipe 4
Drill 21. At the same time as drilling this hole 21, the pipe holder 17
A thrust is also applied to the steel pipe 4 through the steel pipe 4 so that the steel pipe 4 penetrates into the hole 21, and when the steel pipe 4 is penetrated to a predetermined depth in this way, the operation of the rock drill 11 is stopped and the pipe holder 17 is moved to the steel pipe 4. 4 and pull out the piercing rod 14 together with the piercing member 10 from the steel pipe 4 as shown in FIG. The second when this is pulled out
The bit 19 is stored in the bit body 7.

In this way, as shown in FIG. 1, the male screw portions 5 at the rear ends of the plurality of steel pipes 4 which are press-fitted into the ground 2 are connected to the male screw portion 5 shown in FIG.
Screw the injection plug 23 as shown in
Steel pipe 4 by infusion pump 24 connected to the steel pipe via
The reinforcing material is press-fitted in the inside, and the reinforcing material is injected into the ground 2 through the tip opening of the steel pipe 4 and the through hole 6 on the outer periphery. Thus, after the injection of the reinforcing material is completed, the injection plug 23 is removed from the steel pipe 4. Instead, as shown in FIG. 5, a washer 25 is fitted to the steel pipe 4 and a cap nut 26 is screwed to the male thread portion 5 of the steel pipe 4 to form the steel pipe 4.
The gap between the outer periphery of the ground and the ground 2 is sealed with a washer 25, and the ground 2
A continuous reinforcing wall portion 3 is formed inside. When it is desired to perform long processing due to the state of the ground 2, etc., the female screw portion 9 of the trailing steel pipe 4 is screwed into the rear male screw portion 5 of the preceding steel pipe 4 to form a plurality of steel pipes 4. Will be connected.

[0010]

The present invention is as described above, and the invention according to claim 1 has a plurality of through holes on the outer periphery with both ends opened.
Inside the steel pipe having a threaded portion on the outer periphery of the rear end, a perforating member having a bit attached to the tip is removably inserted, and while the steel pipe is press-fit into the natural rock while perforating the natural rock by the perforating member. The piercing member is pulled out of the steel pipe, and is strengthened in the steel pipe by the injection pump connected to the steel pipe through the injection plugs screwed to the male threads of the rear ends of the steel pipes that are thus press-fitted into the ground. Material is press-fitted, the reinforcement is injected into the ground through the opening at the tip of the steel pipe and the through hole on the outer periphery, and after the injection of this reinforcement is completed, the injection plug is removed from the steel pipe, and instead a washer is fitted to the steel pipe. A cap nut is screwed onto the male thread of the steel pipe to seal the gap between the outer periphery and the ground with a washer, so in addition to the steel pipe acting as a support work, It is possible to form a continuous strengthening wall on the A simple injection operation reinforcement can be injected neat when, also injected reinforcement there is an effect that is not as leaks to the outside through between the natural ground and the steel pipe. According to a second aspect of the present invention, in the first aspect of the present invention, a female threaded portion that can be screwed into the male threaded portion is provided inside the front end of the steel pipe, and both threaded portions are screwed as necessary. Since a plurality of steel pipes are connected to perform long processing, in addition to having the same effect as that of the invention of claim 1, when it is desired to perform long processing depending on the state of natural ground, There is an effect that it can be easily carried out by a simple operation of screwing the female thread portion of the trailing steel pipe to the male thread portion of the trailing steel pipe and connecting a plurality of steel pipes.

[Brief description of drawings]

FIG. 1 is a front view showing a reinforced wall portion of a natural ground constructed according to the present invention.

FIG. 2 is a vertical sectional front view showing a perforating step of the present invention.

FIG. 3 is a vertical cross-sectional front view showing a pulling-out process of the punching means of the above.

FIG. 4 is a vertical cross-sectional front view showing the step of injecting the reinforcing material of the above.

FIG. 5 is a vertical sectional front view at the end of all the steps of the above.

[Explanation of symbols]

 1 tunnel 2 ground 3 strengthening wall 4 steel pipe 5 male screw 6 through hole 7 bit body 8 drilling means 9 female screw 10 drilling member 21 hole 23 injection plug 24 injection pump 25 washer 26 cap nut

Claims (2)

[Claims] 1. A perforation means having a bit attached to a tip thereof is removably inserted into a steel pipe having both ends open and a plurality of through holes on an outer periphery and a threaded portion on an outer periphery of a rear end. Then, the steel pipe is press-fitted into the ground while piercing the ground by the piercing means, and the piercing means is extracted from the steel pipe when press-fitting for a predetermined length, and thus the plurality of steel pipes press-fitted into the ground An injection plug is screwed onto the male thread on the rear end, and a reinforcement is pressed into the steel pipe by an injection pump connected to the steel pipe through this injection plug. After injecting the reinforcing material in this way, remove the injection plug from the steel pipe after completing the injection of the reinforcing material, and instead fit a washer on the steel pipe and screw a cap nut to the male thread part of the steel pipe to attach the outer periphery. The gap between the ground and the ground is sealed with a washer,
A method for strengthening natural rocks, characterized by forming continuous strengthening walls inside the natural rocks. 2. A steel pipe is provided with a female screw portion capable of being screwed into the male screw portion inside a front end of the steel pipe. The method of strengthening the natural ground according to claim 1.