JPS58168795A - Method and apparatus for removing exposed part of embedded injection pipe remained in soil during tunnel drilling construction - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] This invention aims to prevent water from flowing out during tunnel excavation work by leaving injection pipes in which chemical liquid has been injected in the surrounding ground buried,
The present invention relates to a method for removing the rear part of an injection pipe exposed to the inside from a tunnel lining part, and an injection pipe used for the method.

Generally speaking, injection pipes for injecting ground hardening chemicals, etc. are pulled out after injection work and used continuously, but if subsidence of the surrounding ground is expected during tunnel excavation work,
If a large number of injection pipes are left buried in the ground solidified by injection, they act like reinforcing bars and strengthen the ground, which is why this method of injection management and leaving them in place has been adopted. .

Incidentally, since injection work in tunnel construction is carried out in the shaft prior to lining work, the rear part of the injection pipe exposed when excavating the shaft to the lining part must be removed. For this reason, the conventional method was to use a burner to burn off the injection pipes that sprayed into the tunnel after excavating the tunnel, but with this method, the large number of injection pipes that remained buried would interfere with the excavation of the tunnel. In addition, there were drawbacks such as difficulty in cutting the exposed portion.

In order to solve the above-mentioned conventional problems, this invention allows the injection pipe to be easily separated and removed from the lining part, allows the removed injection pipe part to be reused, and also allows for the removal of the injection pipe in advance prior to excavation of the tunnel. This paper proposes a method that enables this, and an injection tube for use in this method.

Embodiments of the present invention shown in the drawings will be described below. FIGS. 1(a), 1(b), and 1(c) show the rear end, middle, and tip of an injection tube 1 according to the present invention, respectively. , it has a double tube configuration of an outer tube 2 and an inner tube 3.

The outer tube 2 is integrally formed in a threaded joint portion 4 consisting of male and female positive threads (right-hand threads) with a required number of unit outer tubes 2a, joint outer tubes 2b, and strainer unit outer tubes 2c provided at each tube end. Connect it to .

At its tip, there is a check valve adapter 5 as an outer tube member.
The check valve case 6 and the bit part 7 are sequentially connected.

The outer joint tube 2b has front and rear parts 2b' and 2 which are separately molded.
b'' is connected to the threaded joint part 4 at a male and female reverse threaded joint part 8 which has a reverse thread (left-handed thread), and the inner circumferential surface of each of the front and rear parts 2b' and 2kl" has an axial direction. A series of splines 9 are formed in the.

The inner tube 3 is integrally connected at a male and female threaded joint portion 1o provided at each tube end with a required number of unit inner tubes 3a, a joint inner tube 3b, and a unit inner tube 3c for the tip. The tip part is removably inserted into the center hole 11 of the check valve adapter 5, and the periphery is sealed by an O ring 12, and the end part is inserted into the groove 13 provided on the outer periphery from the outer periphery of the check valve adapter 5. The shear pins 14 that have been attached are engaged, and thereby the unit inner tubes 3c are locked without falling off.

The inner joint pipe 3b has its front and rear parts 3b' and 3t/' connected and integrated by a threaded joint part 12, and has a spline 1 on the outer periphery of the front part that loosely meshes with the spline 9 of the outer joint pipe 2b.
3 is provided, and is inserted into the inner circumference of the reverse threaded joint part 8 of the joint outer pipe 2b while engaging both splines 9 and 13, so that it is slidable in the axial direction but cannot rotate around the axis. In addition, the front and rear parts 2b' and 2 of the joint outer pipe 2b
This front and rear 2t/
, 2b'', the reverse threaded joint portion 8
The two are integrally connected without loosening.

When performing injection work using the injection pipe 1 with the above configuration,
Insert the unit inner pipe 3c into the center hole 11 of the check valve adapter 5 and lock it with a shear pin 14. After connecting the unit inner pipe 3a to this, connect the unit outer pipe 2c for strainer to the check valve adapter 5. , connect the required number of unit inner pipes 3a and unit outer pipes 2a as necessary, and attach a water swivel 1 to each pipe end.
The injection pipe 1 is rotated while the auxiliary inner and outer pipes 15a, 15b of No. 5 are connected and excavated water is pumped to be propelled from the inside of the shaft T into the surrounding ground as shown in FIG. At this time, the drilling water is simultaneously forwarded to the inner and outer flow paths of the inner and outer pipes 2.3, and the ball check valve 16 of the check valve case 6 is opened to allow the drilling water forced into the own flow path to reach the tip of the bit part 7. By discharging the drilling water that has been forced out from the unit outer pipe 2c and further forced into the outer flow path from the outlet 17 of the unit outer pipe 2c, backflow of drilling mud from the unit outer pipe 2c is prevented.

On the other hand, the joint outer pipe 2b and the joint inner pipe 3b spline-fitted thereto are planned so that the reverse threaded joint part 8 is located outside the tunnel lining as shown in Fig. 3 at the end of the injection work. Connect to the parts according to the injection construction plan. Then, while connecting the required number of unit inner and outer tubes 2a and 3a in the same manner, the injection tube 1 is dug until the tip reaches a predetermined injection position. Note that the excavation water forced into the outer flow path at this time flows through the gap between the splines 9 and 13 of the joint inner and outer pipes 2b13b because they are loosely engaged.

When injecting, remove the auxiliary inner and outer tubes 15a and 15b of the water swivel 15, and insert the inner tube 3 as shown in FIG.
A knocking head 19 is connected to the end, and a knocking block loosely fitted around the outer tube 2 is struck against this, thereby applying an impact force in one axial direction to the inner tube 3 to lock the tip. Cut the shear pin 14. In this state, by sequentially pulling out the inner tube 3 from the outer tube 2, the inner joint tube 3b also comes out of the outer joint tube 2b, and the engagement with the front and rear portions 2t/, 2t/' of the outer joint tube 2b is released.

After the inner tube 3 is pulled out in this manner, the water swivel 15 is attached to forcefully feed the chemical solution into the outer tube 2, and a predetermined injection operation is performed.

After the injection work is completed, a rotational force is applied to the rear end of the injection pipe 1 in the same direction as when digging, thereby releasing the engagement with the front and rear parts 2t1' and 2b'' of the outer joint pipe 2b.

After the inner tube 3 is pulled out in this manner, the water swivel 15 is attached to forcefully feed the chemical solution into the outer tube 2, and a predetermined injection operation is performed.

After the injection work is completed, by applying a rotational force in the direction of digging and separation at the rear end of the injection pipe l, the front and rear parts 21 (, 2t/' of the joint outer pipe 2b are separated at the reverse threaded joint part 8, The outer tube 2 behind it can be easily removed.

On the other hand, the outer pipe 2 in front of the reverse threaded joint part 8 is left buried in the surrounding ground outside the planned tunnel lining, and can function like a reinforcing bar to strengthen the ground.

In addition, in the above configuration, the spline 9 of the inner and outer pipes of the joint.
13 does not necessarily need to be formed all around the contact surface, and may be a convex strip or several axial grooves and a convex strip that fits into the grooves.

In addition, although the illustrated embodiment shows a case in which a pre-mixed medicinal solution is injected under pressure, in the case of injecting an instant-setting medicinal solution with a short gel time, it is necessary to inject the medicinal solution into the distal end of the injection tube 1 independently from the inner and outer channels. It has a structure in which a mixing chamber is provided in which the mixed chemical solutions are combined and mixed, and the injection can be carried out without removing the inner pipe 3 during injection,
After this is completed, the inner tube 3 may be removed.As described above, according to the present invention, the outer joint tube connected to the middle part of the injection tube is connected at its front and rear parts with a reverse threaded joint. The inner joint tube is inserted into the outer tube so that it can slide freely in the axial direction at the front and rear, but cannot rotate around the axis, so the reverse threaded joint loosens due to rotation when the injection tube is dug. In addition, when removing the exposed portion of the injection tube, the shear pin that locks the tip of the inner tube must be cut and the inner tube removed. Since it is pulled out together with the inner pipe of the joint,
The front and rear parts of the outer joint pipe are uncoupled, and by rotating the injection pipe in the direction of rotation during excavation, the outer pipe is separated back and forth at the reverse threaded joint located outside the tunnel lining. , the exposed part within the lining can be easily extracted and removed.

Therefore, it can be removed extremely easily without the need for special cutting tools, and the removed outer pipe and pulled-out inner pipe can be reused, making it economical. Moreover, it can be removed prior to excavating the lining. , tunnel excavation work and lining construction can be carried out smoothly.

[Brief explanation of the drawing]

Figures 1(a), (b), and (c) are partial side views showing the tip, middle, and rear end of the injection pipe according to the present invention, and Figure 2 is a longitudinal cross-section of the tunnel portion showing the completed state of injection work. A front view, Figure 3 is a vertical cross-sectional view showing the completed tunnel lining,
FIG. 4 is a longitudinal sectional side view of the shearing pin cutting device. 1...Injection pipe, 2...Outer pipe, 2a, 2c...Unit outer pipe,
2b...Joint outer pipe, 2b'...front, 2b''...rear,
3...Inner pipe, 3a, 3c...Unit inner pipe, 3b...Joint inner pipe, 4.・・Clockwise threaded joint part, 5.・Check valve adapter,
8. Reverse thread joint, 9.13. Spline, 14.
・Sharpei／, T.・Guiding shaft, K.・Lining. Patent applicant Chitakumi Co., Ltd. Sanki Shoji Co., Ltd. Obayashi Corporation

Claims (1)

[Scope of Claims] 1) An injection pipe with a double pipe structure consisting of a required number of unit outer pipes and a unit inner pipe that is inserted into and removably inserted into the outer pipes and sequentially connected by pressure screw joints, respectively. A joint outer pipe whose front and rear parts are connected to the middle part of the joint with a reverse threaded joint, and a joint inner pipe which is inserted into the joint outer pipe so as to be slidable in the axial direction with respect to the front and rear parts thereof and not to rotate around the axis. The tip of the inner tube is locked to the outer tube member at the tip of the injection tube with a shear pin, and the injection tube is inserted from inside the shaft into the ground around the tunnel while rotating to drill a hole. Carry out the injection work, and at the end of the process, position the reverse threaded joint part outside the lining part, apply an axial force to the inner pipe before partially removing the injection pipe, and cut the shearbin. Pull out the inner tube from inside the outer tube, and in this state, apply a rotational force to the outer tube in the same direction as when drilling the hole to separate the outer tube at the rear from the reverse threaded joint of the joint outer tube from the unburied portion at the front. A method for removing an exposed portion of an unburied injection pipe in tunnel construction, which is characterized by removal. 2) Separately, in the middle part of the injection pipe, which has a double pipe structure, consisting of the outer pipe and inner pipe, in which the required number of unit outer pipes and the unit inner pipes inserted into and removably inserted into the inner pipes are sequentially connected with pressure screw joints. A joint outer pipe whose front and rear parts are connected by a reverse threaded joint, and an axial groove inserted into the joint outer pipe and correspondingly provided between the outer circumferential part and the inner peripheral surface of the front and rear parts of the joint outer pipe. and a joint inner tube that is slidable in the axial direction but not rotatable around the axis by a protrusion that engages with the inner tube, and the tip of the inner tube is sheared to the outer tube member at the tip of the injection tube. An injection tube characterized by being locked by.