JP2002364289A - Device and propulsion pipe for preventing backing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a propulsion pipe, which efficiently prevent backing making a propulsion-pipe train pushed back to the side of a starting shaft due to a pipe connection during pipe jacking construction under a pipe jacking method for burying the propulsion pipe, etc., in the ground. SOLUTION: This backing preventing device prevents the backing making the propulsion-pipe train pushed back into the starting shaft by hydraulic pressure and earth pressure, which act on a face plate, at an end, of a boring machine, when the propulsion pipe is connected during the pipe jacking construction. The backing preventing device comprises a pair of supporting materials which are installed ahead of the inside of the starting shaft in such a manner as to face both side surfaces of the propulsion pipe, holding fittings which are provided inside the supporting materials and curved along an outer periphery of the propulsion pipe, tendons which make the supporting materials fastened at a plurality of places, and fixing materials which make the supporting materials fixed to prevent the supporting materials from being displaced backward with respect to a pipe jacking direction. Additionally, the propulsion pipe for preventing the backing, which prevents the backing by using the backing preventing device, is provided with a ring-shaped recess ahead of a steel collar in the rear of the propulsion pipe so as to allow the holding fitting of the supporting material to fall into the recess.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion method in which a propulsion pipe or the like is buried underground. It is about pipes.

[0002]

2. Description of the Related Art The propulsion method is based on pressing the rear end of a row of propulsion pipes with a main push jack installed in a starting shaft while cutting the ground in front of the excavator at the end of the row of propulsion pipes. In general, a method of embedding an excavator and a propulsion pipe at a predetermined position is widely used. The installation of the propulsion pipe during the propulsion construction, once the embedding of one propulsion pipe is completed, reduce the main push jack and install the next propulsion pipe in the space formed between the propulsion pipe and the main push jack, and install A method is used in which the rear end of the propulsion pipe is pressed with a main push jack to connect the propulsion pipe to a previous propulsion pipe.
However, under soil conditions with high groundwater pressure and earth pressure, large water pressure and earth pressure act on the face plate at the tip of the excavator, and when the main push jack is reduced, the propulsion pipe line that follows the excavator and the subsequent It is pushed back to the side and backing occurs. For this reason, there is no space for installing the next propulsion pipe, or the waterproof rubber on the start entrance wall reverses due to the removal of the propulsion pipe and loses water stoppage, causing problems such as groundwater and earth and sand spouting in the shaft. Was.

[0003] For this reason, anchor bolts are embedded in both sides of the propulsion pipe, and the anchors provided on the starting shaft are fixed to each other with wires or steel materials so that the backing of the propulsion pipe is performed by the shearing force of the anchor bolts. Prevention methods are commonly used.

[0004]

In the above-mentioned backing prevention technology, the effect of the backing force is relatively small in the case of the propulsion construction in which the earth covering is shallow and the diameter of the propulsion pipe is small because the backing force is relatively small. It is necessary to embed and install a large number of anchors for fixing anchor bolts to the part,
The work of manufacturing the propulsion pipe becomes complicated. Also, at the time of propulsion construction, before the main jack was reduced, attach the anchor bolt to the anchor of the outer wall of the propulsion pipe, tie it with the anchor provided on the starting shaft wall, and then reduce the main jack. Hangs the next propulsion pipe in that space, removes the wire after connecting with the previous propulsion pipe, and removes the anchor bolts attached to the outer wall of the propulsion pipe. Was significantly reduced. Especially in the case of a large-diameter propulsion pipe or when a relatively large backing force is applied, the number of anchor bolts increases, so it takes time to install and remove the anchor bolts, and it takes no time to bury the propulsion pipe. Problems also arise. Further, since the force of the anchor bolt acts on the anchor portion of the outer wall of the propulsion pipe, the outer wall is damaged.

[0005] Therefore, the present invention provides a backing prevention device and a backing prevention propulsion tube that can efficiently and easily prevent backing of the propulsion tube without damaging the outer wall of the propulsion tube.

[0006]

That is, the present invention prevents backing in which a row of propulsion pipes is pushed back into the starting shaft by water pressure or earth pressure acting on the excavator face plate at the tip when the propulsion pipe is connected during propulsion construction. A pair of support members installed in front of the start shaft and opposed to both side surfaces of the propulsion tube, and provided inside the pair of support members, and curved along the outer periphery of the propulsion tube. A backing prevention device comprising a holding metal, a tension member for tightening the pair of support members at a plurality of locations, and a fixing member for fixing the pair of support members so as not to move backward in the propulsion direction. Further, a propulsion tube for preventing backing using the backing prevention device described above, wherein a recess is provided in a ring shape so that the holding member of the support material can be dropped in front of a steel collar behind the propulsion tube. This is a backing prevention propulsion tube.

[0007] The support material must have relatively high strength in order to press the outer periphery of the propulsion tube with the holding metal, and a steel material such as an H-shaped steel is used. The length of the support is made longer than the outer diameter of the propulsion tube to clamp at the top of the propulsion tube. The holding member provided on the supporting member is formed to be curved along the outer periphery of the propulsion pipe, and has a predetermined length in the circumferential direction to evenly distribute the tightening force from the supporting member. A large frictional force can be generated by attaching a rubber material to the contact surface of the holding member.

The tension member tightens and fixes the outer periphery of the propulsion tube with a holding metal by pulling the pair of support members inward. As the tensioning means, a device according to the prior art using a tension such as a PC steel material or a chain block may be used. Tensioners are installed at two locations, upper and lower, where they do not hinder the propulsion pipe.

The fixing member is disposed and fixed behind the supporting member so that the pair of supporting members do not move rearward in the propulsion direction. As a fixing method of the fixing member, a method of supporting the supporting shaft on both sides of the propulsion pipe from behind the starting shaft wall with a supporting material, a method of supporting the anchoring member provided in front of the starting shaft wall, or the like may be adopted. As the fixing material, it is necessary to support a relatively large backing force, and a strong H-shaped steel material or the like is used.

The recess provided at the rear of the propulsion tube may be manufactured by welding a ring-shaped cylinder so as to be inscribed on the inner surface of the steel collar, or may be formed as an integral structure formed by processing the steel collar. . The backing-preventing propulsion pipe having a concave portion can be used not only for reinforced concrete pipes but also for all propulsion pipes such as synthetic steel pipes and steel pipes.

When the propulsion construction of one propulsion pipe is completed,
By pulling the pair of support members inward by a tensioning means such as a PC steel member provided on the support member, the outer periphery of the propulsion pipe is clamped by a holding metal. For this reason, the propulsion tube is held and fixed by being restrained by the frictional force of the holding metal. Then, the main push jack is reduced, a space is secured between the rear end of the propulsion pipe and the head of the main push jack, and the next propulsion pipe is suspended and installed. When the installation is completed and the rear end of the next propulsion tube is pressurized with the main push jack to complete the connection of the propulsion tube, the tensioning means of the support material is released and the propulsion tube is not restrained. Then, the propulsion burial of the next propulsion pipe is resumed. Furthermore, by providing a recess behind the propulsion tube,
The force holding and holding the propulsion tube becomes the frictional force and the shearing force,
A very large backing prevention force can be obtained.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view illustrating a backing prevention device of the present invention. The propulsion tube 1 installed in the starting shaft is supported and fixed by a pair of rail members 8 provided below both side surfaces of the propulsion tube 1 and is buried in a planned direction. On both side surfaces of the propulsion tube 1, a pair of support members 2 having a height higher than the outer diameter of the propulsion tube 1 are provided. Inside the pair of support members 2, a holding metal fitting 3 curved along the outer periphery of the propulsion pipe 1 is provided. A pair of support members 2
A fixing member 6 is installed on the rear upper portion so as to abut against the supporting member 2, and both ends thereof are fixed to a starting shaft wall 18. At the lower rear part of the support member 2, a fixing member 6 is installed so as to contact the support member 2, and both ends thereof are connected to the starting shaft wall 18.
And the rail member 8. Above and below the pair of support members 2, tension members 4 such as PC steel materials are installed through the support members 2, and both ends thereof are fixed by fixing members 5 such as nuts. At one end of the upper tendon 4, a support 2 and a fixture 5
By equipping the tension jack 7 between them, the tension member 4 can be efficiently tightened or loosened.

In the present embodiment, the method of using the tension jack 7 for tightening the tension member 4 has been disclosed. However, a method of directly tightening or loosening the fixing members 5 at both ends can also be used. The number of used tendons 4 and the caliber are changed in accordance with the backing force calculated in advance.

The pair of support members 2 and fixing members 6 are made of a relatively strong steel material such as an H-shaped steel in order to withstand a large backing force.

Pressing metal fittings 3 provided on a pair of supporting members 2
By attaching a rubber material to the portion that comes into contact with the propulsion tube 1, the transmission of the tension from the support member 2 can be made uniform, and the frictional force with the propulsion tube 1 can be increased.

FIG. 2 is a plan view illustrating a backing prevention device according to the present invention. A pair of support members 2 are provided behind the starting wellhead wall 9 provided on the front surface of the starting shaft so as to face both sides of the propulsion pipe 1. The pair of support members 2 are provided with tension members 4 that penetrate the support member 2 and are fixed at both ends by fixtures 5. Behind the pair of support members 2,
The fixing member 6 is fixed to the starting shaft walls 18 on both sides so as to abut on the support member 2. At both ends of the fixing member 6, reinforcing members 19 for supporting the fixing member from the starting shaft wall 18 are attached.

Although the embodiment in which the reinforcing member 19 is provided obliquely from the starting shaft wall 18 to reinforce the fixing member 6 has been disclosed, when the backing force is very large, from the rear of the starting shaft wall 18 to the fixing member 6. It is also possible to use a method of extending and supporting a plurality of pressing members.

Next, a method for preventing backing of a propulsion pipe using the present apparatus will be described. When the propulsion construction of one propulsion tube 1 is completed, the rear end face of the propulsion tube 1 is supported while the original push jack 10 is extended, and the tension jack 7 provided on the support member 2 is extended to form a pair of propulsion jacks. The support 2 is pulled inward. By tightening the support member 2, the holding member 3 comes into close contact with the outer periphery of the propulsion tube 1 and holds and fixes the propulsion tube 1. Then, the main push jack 10 is reduced to secure a space between the rear end of the propulsion pipe 1 and the head of the main push jack 10. The next propulsion pipe 1 is suspended and installed in the space. When the installation of the propulsion tube 1 is completed, the rear end of the next propulsion tube 1 is pressurized by the main push jack 10 so that the rear end surface of the previous propulsion tube 1 is brought into contact with the front end surface of the next propulsion tube 1 for propulsion. When the connection of the pipe 1 is completed, the tension jack 7 of the support 2 is reduced to loosen the support 2 and the propulsion pipe 1 is opened. Then, the propulsion burial of the next propulsion pipe 1 is restarted.

FIG. 3 is a longitudinal sectional view for explaining a backing preventing propulsion pipe according to the present invention. A ring-shaped recess 13 is provided in front of a steel collar 12 fixed to the outer peripheral surface of the rear end of the reinforced concrete propulsion pipe 1. The configuration of the concave portion 13 is such that a ring-shaped concave cylindrical body 14 is fixed by welding or the like so as to be inscribed in the steel collar 12, and the concave cylindrical body 14 is fixed.
Is formed by covering a front cylindrical body 15 having the same diameter as the steel collar 12 on the front surface thereof and fixing it by welding or the like. Ring-shaped recess 1
The width of 3 is a size in which the holding metal fitting 3 provided on the support member 2 fits.

In the present embodiment, the propulsion pipe 1 made of reinforced concrete is disclosed. However, the present invention is not limited to the reinforced concrete pipe, but may be applied to a propulsion pipe such as a synthetic steel pipe or a steel pipe.

FIG. 4 is a longitudinal sectional view for explaining the concave portion in detail. A steel collar 12 fixed to the outer peripheral surface of the rear end of the concrete propulsion pipe 1 projects rearward by a certain length so that the front end of the next propulsion pipe 1 can be inserted. Propulsion pipe 1
A ring-shaped recessed cylindrical body 14 is welded to the front steel collar 12 fixed to the concrete part so as to be inscribed in the steel collar 12. The outer periphery of the front end of the concave cylindrical body 14 is covered with a front cylindrical body 15 having the same diameter as the steel collar 12 and welded to form a concave 13 between the steel collar 12 and the front cylindrical body 15. . The holding metal 3 of the supporting material 2 is provided in the recess 13.
Is stuck. On the inner peripheral surface of the concave cylinder 14, there are provided a ring-shaped anchor streak 17 for fixing the concave cylinder 14 to concrete and a ring-shaped embedding water-stopping material 16 for maintaining water-stopping.

In this embodiment, the formation of the concave portion 13 is described by combining a ring-shaped cylinder, but it is also possible to integrate the steel collar 12 and process it with a single steel material. It is.

[0023]

As described above, according to the backing prevention device of the present invention, the propulsion pipe can be held and fixed or opened simply by tensioning or loosening the tension member above the pair of support members. The complicated work of installing and removing a plurality of anchor bolts as in the prior art has been eliminated, and a very efficient backing prevention work can be performed.
When a relatively large backing force is applied,
By using the backing prevention propulsion tube in combination, the backing prevention force can be obtained by the frictional force and the shearing force of the recess provided in the propulsion tube, and the backing prevention excellent in safety can be achieved.

[0024]

[Brief description of the drawings]

FIG. 1 is a front view illustrating a backing prevention device of the present invention.

FIG. 2 is a plan view illustrating a backing prevention device of the present invention.

FIG. 3 is a vertical cross-sectional view illustrating a backing prevention propulsion tube according to the present invention.

FIG. 4 is a longitudinal sectional view for explaining a recess in detail.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Propulsion pipe 2 Support material 3 Holder 4 Tension material 5 Fixing device 6 Fixing material 7 Tension jack 8 Rail material 9 Starting wellhead wall 10 Main push jack 11 Bearing wall 12 Steel collar 13 Depression 14 Depression cylinder 15 Front cylinder 16 Water stopping material for embedding 17 Anchor bar 18 Starting shaft wall 19 Reinforcing material

Claims (2)

[Claims] 1. A device for preventing a backing in which a row of propulsion tubes is pushed back into a start shaft by water pressure or earth pressure acting on a front excavator face plate at the time of connection of the propulsion tube during propulsion construction. Forward, a pair of support members installed to face both side surfaces of the propulsion tube; a holding metal fitting provided inside the pair of support members and curved along the outer periphery of the propulsion tube; and the pair of support members A backing prevention device comprising: a tension member for fastening members at a plurality of locations; and a fixing member for fixing the pair of support members so as not to move backward in the propulsion direction. 2. A propulsion pipe for preventing backing by using the backing prevention device according to claim 1, wherein a ring-shaped holding member for the support member can be dropped in front of a steel collar behind the propulsion pipe. A backing prevention propulsion tube, characterized in that a recess is provided in the backing.