JP5939704B2 - Backing prevention propulsion pipe - Google Patents

Description

  The present invention relates to a propulsion pipe for preventing the backing of a propulsion pipe row that is pushed back to the start shaft when a propulsion pipe is connected during propulsion in the propulsion method.

  In the propulsion work, the ground end in front of the excavator mounted on the head of the propulsion pipe row is cut with a cutting bit, etc., while the rear end of the propulsion pipe row is fixed with a main jack installed in the start shaft. In this method, the excavator and the propelling pipe line are embedded at predetermined positions by pressing. The connection of the propulsion pipe during the propulsion work is completed when one propulsion pipe is buried, the main jack is reduced in the start shaft, and the space formed between the rear end of the propulsion pipe and the head of the main push jack is reduced. A method is used in which the next propulsion pipe is suspended and installed, and the rear end of the installed propulsion pipe is pressed with a main jack to connect to the previous propulsion pipe. However, under soil conditions with high groundwater pressure or earth pressure, large water pressure and earth pressure act on the faceplate at the tip of the excavator, so when the main jack is reduced when the propulsion pipe is connected, the subsequent propulsion with the excavator The tube row generates a backing that is pushed back backwards. For this reason, there is no space for installing the next propulsion pipe, or the water stop rubber on the start pit wall is reversed due to the removal of the propulsion pipe, and there is no water stop and groundwater and earth and sand erupt into the start pit. was there.

For this reason, a method is generally used in which a steel wire is tightened around the outer peripheral surface of the propulsion tube and the propulsion tube is prevented from retreating by frictional force. However, the friction between the steel wire and the outer peripheral surface of the propulsion tube has been used. A large backing force was not obtained by force alone, and it was used only for soil conditions such as water pressure and construction conditions with a small pipe diameter.

Therefore, in recent years, an insert anchor system is often used so as to obtain a large backing force. The method comprises a plurality of insert anchors installed on both side surfaces outside the propulsion pipe and a contact plate projecting at right angles to the outer distribution plate contacting the outer wall surface of the pipe at the insert anchor portion. The support plate is fixed with a plurality of bolts. The support plate is a method of contacting and supporting a receiving plate fixed on a propulsion stand or the like installed on both sides of the propulsion pipe. The support plate is fixed with a plurality of bolts, and a relatively large backing reaction force can be obtained. As another method for preventing backing, a grout hole provided on both side surfaces of the propulsion pipe penetrates the propulsion pipe wall and protrudes outward by a predetermined length, and is inserted into the position of the protuberance. An inner distribution plate that is provided so as to contact the inner wall surface of the pipe with a hole, an inner fixing bracket that fixes the protruding rod through the inner distribution plate, and an insertion hole at the protruding rod position on the outer side of the propulsion tube A cylindrical insertion tube is fixed to the outer distribution plate so as to cover the fitting insertion hole on the outer distribution plate installed so as to contact the outer wall surface of the tube, and a front side surface of the insertion tube is separated from the outer distribution plate. Protruding rod method using a preventing device comprising: a backing force support fitting that is reinforced and fixed by a reinforcing material; and an outer fixing fitting that fixes an end of the protruding rod that protrudes from the insertion hole of the backing force support fitting. Has been developed.

Although the two backing prevention methods described above have made it possible to obtain a large backing reaction force, the following problems have occurred. In the insert anchor method, it is possible to increase or decrease the number of insert anchors according to the backing force. Since there are many drill holes for insert anchors on the wall of the propulsion pipe, there is a problem that the orderer does not permit this method due to concern about the decrease in pipe strength, and installation in the insert anchor A problem has arisen that it takes a lot of time to install and remove bolts. In the protruding rod system, it is possible to increase or decrease the diameter of the protruding rod according to the magnitude of the backing force, and it is only necessary to insert the protruding rod into the grout holes provided on both sides of the propulsion pipe, which is efficient. Although the backing can be prevented, if the backing force is increased, the concrete strength of the grout hole portion is insufficient and the problem of breaking occurs.
JP 2008-82068 A

  For this reason, the problem to be solved by the invention is to provide a propulsion pipe for backing prevention that can be easily and reliably prevented against a large backing force generated during propulsion construction.

INDUSTRIAL APPLICABILITY The present invention is used to prevent the propulsion pipe row from being pushed back to the start shaft side by water pressure or earth pressure acting on the tip excavator face plate when the propulsion pipe made of reinforcing steel concrete is being connected. A propulsion pipe,
Backing prevention constructed by fixing an annular reinforcing plate having a predetermined length in the propulsion direction on the outer peripheral surface of the concrete behind the propulsion pipe so as to be substantially the same diameter as the outer diameter of the propulsion pipe For propulsion pipes.

  Reinforced concrete propulsion pipes are generally standard steel reinforced concrete pipes for the sewer propulsion method, and are roughly divided into standard pipes and intermediate push pipes depending on their shapes. The target is at the time of initial propulsion work with little resistance to the outer peripheral surface of the pipe and is mainly a standard pipe. As for the shape of the standard tube, the tip is provided with a paragraph portion whose diameter is smaller than the outer diameter of the tube so as to be fitted in a steel collar fixed to the outer peripheral portion of the rear end of the front propulsion tube. A ring-shaped water-stopping rubber is attached to the reduced diameter portion and abuts against the inner surface of the steel collar to prevent outflow of groundwater and earth and sand into the pipe. At the rear end, a steel collar to which the next propulsion pipe can be fitted is fixed to the outer wall surface.

  In the reinforcing plate, an annular steel plate having a predetermined length in the propulsion direction and substantially the same diameter as the outer diameter of the propulsion pipe is fixed to the concrete wall surface. The installation location is installed in the rear part of the propulsion pipe so that the propulsion pipe for one can be pushed in reliably. When using the protruding saddle method, the grout holes may be arranged on both side surfaces of the reinforcing plate installation position. The diameter of the grout hole is determined in accordance with a backing force assumed in advance. When the insert anchor method is used, it is not necessary to align the grout hole at the position of the reinforcing plate, and it is only necessary that support plates can be fixed on both side surfaces of the reinforcing plate. As a method for fixing the support plate, a method in which an insert anchor is fixed to a reinforcing plate in advance is generally used, and the support plate is fixed and removed by a plurality of bolts.

Although the method of fixing the insert anchor to the reinforcing plate in advance by the insert anchor method has been disclosed, a method of welding the support plate to the reinforcing plate can also be used. The support plate is generally removed by gas cutting. However, since the cut surface is uneven, it is necessary to smooth the outer surface with a grinder or the like to reduce the outer peripheral surface resistance. As a method for fixing the support plate, an efficient method may be selected in consideration of construction conditions, the magnitude of the backing force, and the like.

In the propulsion pipe for preventing backing according to the present invention, the reinforcing plate fixed on the outer peripheral surface behind the propulsion pipe is responsible for the large backing force acting on the concrete wall of the propulsion pipe by the protruding anchor method or the insert anchor method. The concrete wall of the grout hole was not damaged and the insert anchor was not pulled out. For this reason, the excavator and the propulsion pipe can be reliably prevented from backing by the protruding saddle type backing force support bracket and the insert anchor type support plate, and safe and efficient propulsion can be performed. .

  A propulsion pipe for preventing backing has been realized that can reliably prevent the backing pipe from being pushed back to the start shaft when the propulsion pipe is connected during propulsion.

  FIG. 1 is a plan view illustrating a propelling pipe for preventing backing according to the present invention. The front end of the propulsion pipe 1 is smaller than the outer diameter of the propulsion pipe 1 so that the front end of the propulsion pipe 1 can be fitted into a steel collar 5 fixed to the outer peripheral portion of the rear end of the concrete wall 2 of the propulsion pipe 1. A stepped portion 6 having a diameter is provided. When a ring-shaped water-stopping rubber (not shown) is attached to the central portion of the stepped portion 6 and is inserted into the steel collar 5, it abuts against the inner peripheral surface of the steel collar 5 and groundwater or earth and sand. Prevents outflow in the pipe. An annular reinforcing plate 4 having a predetermined length in the propulsion direction is fixed to the outer peripheral surface of the concrete wall 2 behind the propulsion pipe 1 so as to have the same diameter as the outer diameter of the propulsion pipe. . Grout holes 3 are provided on both side surfaces of the reinforcing plate 4 at symmetrical positions. At the rear end of the propulsion pipe 1, a steel collar 5 to which the next stage section 6 of the propulsion pipe 1 can be fitted is fixed to the outer surface of the concrete wall 2.

  In this embodiment, the projecting rod type propulsion pipe 1 in which the projecting rod 9 is inserted into the grout hole 3 is disclosed. However, if the insert anchor type propulsion tube 1 is used, the position of the grout hole 3 is set as a reinforcing plate. It is not necessary to provide in 4 parts, and it becomes possible to install also in the up-and-down direction in order to perform efficient lubricant and backfill injection.

  The reinforcement plate 4 is installed at the rear position where the backing force support bracket supported by the projecting rod 9 does not hit the starting pit wall provided in front of the starting pit when the propulsion construction of one propulsion pipe is completed. It is done. As a material of the reinforcing material 4, a steel material having a relatively strong strength may be employed so as to be able to resist the backing force transmitted by the protruding rod 9. By providing a plurality of anchor bars on the inner peripheral surface of the reinforcing plate 4, it is possible to further strengthen the adhesion of the propulsion pipe 1 to the concrete wall surface.

  FIG. 2 is a cross-sectional view illustrating the reinforcing plate of the present invention in detail. A reinforcing plate 4 is fixed to the outer peripheral surface of the concrete wall 2 of the propulsion pipe 1 with a predetermined length in the propulsion direction so as to have the same diameter as the outer diameter of the propulsion pipe 1. A grout hole 3 is installed in the central portion of the reinforcing plate 4 so as to penetrate the concrete wall 2, and the outer portion is fixed to the reinforcing plate 4 by welding or the like. The size of the grout hole 3 is manufactured to have a diameter that allows the protruding rod 9 determined to be able to withstand a backing force assumed in advance to be fitted.

  FIG. 3 is a cross-sectional view for explaining a method of preventing the protruding hook type backing. The inner end portion of the protruding rod 9 that protrudes outward by a predetermined length through the concrete wall 2 through the grout holes provided on both side surfaces of the propulsion pipe 1 is inserted into the nut through the fitting insertion hole of the inner distribution plate 10. It fixes with the inner side fixing metal fitting 11 by etc. A cylindrical insertion is provided on the outside of the propulsion tube 1 so as to cover the insertion hole in an outer distribution plate 12 provided with an insertion hole provided at the position of the projecting rod 9 and in contact with the outer peripheral surface of the concrete wall 2. The backing force support fitting in which the tube 13 is fixed to the outer distribution plate 12 and the front side surface of the insertion tube 13 is reinforced and fixed from the outer distribution plate 12 with a rib-shaped reinforcing material is projected from the insertion tube 13. The flange 9 is fixed by tightening the front end of the flange 9 with an outer fixing bracket 14 such as a nut. The backing force support bracket is attached to the position of the reinforcing plate 4 when the propulsion work for one propulsion pipe 1 is completed, and the backing force support bracket is attached to the rearward movement prevention bracket 7 installed on both sides of the propulsion pipe 1. The insertion tube 13 is in abutment structure. For this reason, the backing force support fitting is supported by the backward movement prevention fittings 7 on both sides, and the propulsion pipe 1 is prevented from moving backward.

  The rear movement blocking metal member 7 needs to support a large backing force, and a steel material such as H-shaped steel having strong strength is used, and is firmly fixed from the front and back with a support material such as a steel material.

FIG. 4 is a cross-sectional view for explaining an insert anchor type backing prevention method. When the propulsion construction for one propulsion pipe 1 is completed, the support composed of the outer distribution plate and the contact plate is formed on both side surfaces of the reinforcing plate 4 fixed to the outer peripheral surface of the concrete wall 2 of the propulsion pipe 1. The plate 8 is fixed by welding. Behind the support plate 8, the rear movement prevention metal fitting 7 is fixed so as to abut against the propulsion pipe 1.

  As described above, the propulsion pipe for preventing backing according to the present invention can be applied to propulsion work under soil conditions under high water pressure where there is a large amount of groundwater with a large backing force and construction conditions with a large propulsion pipe diameter.

It is a top view explaining the propelling pipe for backing prevention of the present invention. It is sectional drawing explaining the reinforcement board of this invention in detail. It is sectional drawing explaining the protrusion prevention method backing prevention method. It is sectional drawing explaining the backing prevention method of an insert anchor system.

1 Propulsion pipe 2 Concrete wall 3 Grout hole 4 Reinforcement plate 5 Steel collar
6 Stepped portion 7 Back movement prevention metal fitting 8 Support plate 9 Protruding rod 10 Inner distribution plate 11 Inner fixing bracket 12 Outer distribution plate 13 Insertion tube 14 Outer fixing bracket

Claims (1)

This is a propulsion pipe that is used to prevent the propulsion pipe row from being pushed back to the start shaft side by water pressure or earth pressure acting on the excavator face plate at the tip when the propulsion pipe made of reinforcing steel concrete is being connected. And
An annular reinforcing plate having a predetermined length in the propulsion direction is fixed to the concrete outer surface of the concrete behind the propulsion pipe so as to be approximately the same diameter as the outer diameter of the propulsion pipe. A characteristic propulsion tube for backing prevention.

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