JP2008082068A - Backing preventing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device which quickly and effectively prevents a line of pipes from being pushed back toward a starting shaft when pipes are connected in the process of jacking the pipes in a pipe jacking method. <P>SOLUTION: The device includes a projecting rod which penetrates the wall of a jacking pipe to project outward by a given length. The device also includes inside the jacking pipe an internal distribution board which has an insertion hole at the position of the projecting rod and is set to be in contact with the inner wall surface of the jacking pipe, and an internal metal fixture which fixes the projecting rod via the internal distribution board. The device also includes outside the jacking pipe an external distribution board which has an insertion hole at the position of the projecting rod and is set to be in contact with the outer wall surface of the jacking pipe, a cylindrical insertion cylinder which is so fixed to the external distribution board as to cover the insertion hole, a backing force support metal fitting which fixes and reinforces the front side face of the insertion cylinder with a reinforcing material from the side of the external distribution board in an integral manner, and an external metal fitting which fixes an end of the projecting rod projecting out of the insertion cylinder of the backing force support metal fitting. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  The propulsion method uses an excavator machine by pressing the rearmost end of the propulsion pipe row with a main push jack installed in the starting shaft while cutting the ground in front with the face plate at the tip of the excavator installed at the tip of the propulsion pipe row. And a method of burying the propelling tube row at a predetermined position. The connection of the propulsion pipe during the propulsion construction is completed when one propulsion pipe is buried, the main jack is reduced in the start shaft, and the next propulsion pipe is placed in the space formed between the propulsion pipe and the main jack. Is 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 and earth pressure, large water pressure and earth pressure are acting on the faceplate at the tip of the excavator. The propulsion tube row that produces the backing is pushed back. For this reason, there is a problem that there is no space for installing the next propulsion pipe, the water stop rubber on the start pit wall is reversed by the removal of the propulsion pipe, the water stoppage is lost, and groundwater and earth and sand erupt in the vertical shaft. It was.

  For this reason, a method of turning and tightening a steel wire around the outer peripheral surface of the propulsion tube and preventing the propulsion tube from retreating with frictional force was generally used, but only the frictional force between the steel wire and the outer peripheral surface of the propulsion tube was used. However, it was not used for preventing large backing and was used only for soil conditions such as water pressure and construction conditions with a small pipe diameter.

  Therefore, in recent years, many insert anchor methods have been adopted so as to obtain a large backing force. In this method, a plurality of insert anchors are installed on both side surfaces outside the propulsion pipe, and a plurality of support plates are fixed to the insert anchor portion with a plurality of bolts. The support plate is a method in which the support plate is supported in contact with a receiving plate on a propulsion base 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, there are a pair of support members installed on both sides of the propulsion pipe, a press fitting provided on the inner side of the support member and curved along the outer periphery of the propulsion pipe, and a pair of support members. A backing prevention method that tightens the outer peripheral surface of the propulsion pipe with a large force by a device composed of a tension material that clamps the material at multiple locations and a fixing material that fixes the pair of support materials so that they do not move backward in the propulsion direction. Has been developed.

Japanese Patent No. 3751222

  The above-mentioned insert anchor method can increase or decrease the number of insert anchors according to the magnitude of the backing force, but in the case of a large backing force, the number of insert anchors for fixing the support plate becomes very large. There is a problem that it takes a lot of time to attach and remove the bolts installed on the insert anchor, and the time required for the propulsion work is remarkably reduced. Moreover, the hole-filling process of an insert anchor part is also needed, and more labor and cost will be needed if the number of installation increases. Furthermore, the method of tightening the outer periphery of the propulsion pipe with a pair of support materials requires a strong tightening force in order to obtain a large backing prevention force. There is a problem that it is necessary to reinforce the pipe material by winding it to have a large strength, and the pipe material cost becomes very expensive. For this reason, this invention is providing the backing prevention apparatus which can prevent easily and reliably even with a big backing force.

The present invention is an apparatus for preventing the backing of the propelling pipe row from being pushed back to the starting shaft side by water pressure or earth pressure acting on the excavator face plate at the tip when the propulsion pipe is being propelled.
A rod-like projecting rod that penetrates the propulsion tube wall and projects outward by a predetermined length through grout holes provided on both side surfaces of the propulsion tube, and an insertion hole at the projecting rod position on the inner side of the propulsion tube An inner distribution plate installed so as to be in contact with the inner wall surface of the pipe, an inner fixing bracket for fixing the protruding rod through the inner distribution plate, and a pipe provided with an insertion hole at the position of the protruding rod on the outer side of the propelling tube A cylindrical insertion tube is fixed to the outer distribution plate so as to cover the fitting hole on the outer distribution plate installed so as to contact the outer wall surface, and the front side surface of the insertion tube is reinforced from the outer distribution plate. Backing prevention support characterized by comprising a backing force support bracket integrated by reinforcing and fixing with a material, and an outer fixing bracket for fixing the end portion of the protruding collar protruding from the insertion tube of the backing force support bracket apparatus.

  The protruding rod inserted into the grout hole is subjected to strength examination in advance so that the material and outer diameter of the protruding rod are determined so as not to be deformed or damaged with respect to the assumed backing force.

  The inner fixing bracket may be any one that does not allow the protruding rod to come out, and a commonly used nut or the like is used. The inner distribution plate is brought into contact with the tube wall surface in a square or circular shape so that the output of the protruding rod can be widely transmitted to the propulsion tube. As the material of the inner distribution plate, a steel material having a relatively high strength is used so as not to cause deformation or damage to the pulling force.

  The insertion cylinder of the backing force support bracket has an inner diameter with a margin in the outer diameter of the protruding collar so that the protruding collar can be inserted smoothly. In order to reinforce the front side surface of the insertion tube with a reinforcing material, the outer distribution plate is brought into contact with the pipe wall surface in a square or circular shape extending forward by a predetermined length.

  The backing force support fitting is fixed by attaching a nut or the like, which is an outer fixing fitting, to a protruding rod protruding through the insertion tube and tightening the head of the insertion tube.

  A rearward movement prevention metal fitting abuts on the rear side surface of the insertion tube of the backing force support metal fitting to prevent the rearward movement of the backing force support metal fitting. The backward movement prevention metal fitting is vertically installed on both sides of the propulsion pipe, and has a structure that is supported from the front or rear of the start shaft wall so that it cannot move backward from the position. Since the material of the rearward movement prevention metal fitting receives a relatively large backing force from the backing force support fitting, it is made of a material such as an H-type steel material.

  Since the backing preventing apparatus of the present invention uses the grout holes previously installed on both side surfaces of the propulsion pipe, it is possible to employ a protruding rod having a relatively large cross section and obtain a large backing preventing force at one place. In addition, the installation and removal of the backing prevention device can be performed efficiently with only two places on both sides.

  During the construction of the propulsion method, the technology that can easily and reliably prevent the backing that pushes back the excavator and the propelling pipe row back by water pressure and earth pressure is used by using the grout holes installed on both sides.

  FIG. 1 is a plan view for explaining a backing preventing apparatus according to the present invention. Grout holes 2 having a predetermined inner diameter are provided on both side surfaces of the propulsion pipe 1. The grout hole 2 is provided with a rod-like protruding rod 3 that penetrates the wall of the propulsion pipe 1 and protrudes outward by a predetermined length. The inner wall surface of the propelling tube 1 is in contact with a rectangular inner distribution plate 4 provided with a fitting hole for passing the protruding rod 3, and the end of the protruding rod 3 protruding from the fitting hole has an inner distribution. It is fixed via a plate 4 with a nut or the like which is an inner fixing metal fitting 5. The projecting rod 3 projecting outside the propulsion tube 1 is provided with a fitting hole at the position of the projecting rod 3 and provided in the rectangular outer distribution plate 6 provided so as to contact the outer wall surface of the propelling tube 1. An outer distribution plate is formed by fixing a cylindrical insertion tube 7 to the outer distribution plate 6 so as to cover, and reinforcing and fixing the front side surface of the insertion tube 7 from the outer distribution plate 6 with a reinforcing material 9. 6 is inserted from the fitting hole 6 into the protruding rod 3 and installed. The end of the protruding rod 3 protruding from the insertion tube 7 of the backing support fitting is fixed by a nut or the like that is the outer fixing fitting 8.

  A rearward movement-preventing metal fitting 10 made of an H-type steel material or the like abuts on the rear side surface of the insertion cylinder 7 of the backing support metal fitting to prevent the backward movement of the backing force support metal fitting. The backward movement prevention metal fitting 10 is vertically installed on both sides of the propulsion pipe, and has a structure that is firmly supported from the front or rear of the start shaft wall so that it cannot move backward from the position.

  The protruding rod 3 to be inserted into the grout hole 2 changes the material and outer diameter of the protruding rod 3 by conducting a strength study in advance so that deformation and damage do not occur with respect to the assumed backing force.

  The inner fixing bracket 5 and the outer fixing bracket 8 that fix the protruding rod 3 inside and outside the propelling pipe 1 may be any one as long as the protruding rod 3 does not come out or move, and a nut or the like that is normally used as a conventional technique is used. .

  FIG. 2 is a cross-sectional view illustrating the backing preventing apparatus of the present invention. The inner distribution plate 4 and the outer distribution plate 6 are preferably curved and brought into contact with the inner and outer wall surfaces of the propulsion pipe 1 in order to distribute the backing force received by the protruding rods 3 evenly over a wide range. In order to support and fix the inner distribution plate 4 and the backing support fitting with the inner fixing fitting 5 and the outer fixing fitting 8, both ends of the projecting rod 3 are threaded.

  Next, the usage situation of the backing prevention apparatus of this invention is demonstrated. When the propulsion construction of one propulsion pipe 1 is completed, the projecting rod 3 penetrates through the grout holes 2 on both side surfaces of the propulsion tube 1 from the outside, and the inner anchor bracket 5 projects through the fitting holes of the inner distribution plate 4. To fix. Then, from the outside, the insertion tube 7 of the backing support fitting is passed through the protruding hook 3, and the backing support fitting is fixed from the front end portion of the protruding hook 3 with the outer fixing fitting 8.

    Behind the insertion tube 7 of the backing support metal fitting, a rear movement prevention metal fitting 10 made of H steel or the like is vertically installed, and is firmly supported and fixed from the front or rear of the start shaft wall so that it cannot move backward from the position. Has been.

  When the installation of the backing prevention device is completed, the main jack (not shown) is reduced, the rear end of the propulsion pipe 1 is opened, and one row of the propulsion pipes is formed by the backing force due to the groundwater pressure or earth pressure applied to the tip of the excavator. Trying to push backwards. However, the backing support fittings installed on both side surfaces of the rearmost propulsion pipe 1 abut against the rearward movement prevention fitting 10 to prevent backward movement. For this reason, a space for installing the next propulsion pipe 1 can be secured in front of the main push jack and behind the rearmost push pipe 1 by reducing the main push jack.

  When the installation of the next propulsion pipe 1 is completed, the main push jack is extended, and the front end of the next propulsion pipe 1 is fitted and connected to the rear end of the front propulsion pipe 1. When the connection of the propulsion pipe 1 is completed, the backing preventing device is removed while the pressure of the main push jack is being applied, and a check valve and a cover are attached to the grout hole 2 and the propulsion work is resumed.

  It can be applied to propulsion work under soil conditions with high groundwater pressure and deep soil cover.

It is a top view explaining the backing prevention apparatus of the present invention. It is a cross-sectional view explaining the backing prevention apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Propulsion pipe 2 Grout hole 3 Protruding rod 4 Inner distribution plate 5 Inner fixing bracket 6 Outer distribution plate 7 Insertion tube
8 Outer fixing bracket 9 Reinforcement material 10 Back movement prevention bracket

Claims (1)

In the device for preventing the backing of the propelling pipe row being pushed back to the start shaft side by the water pressure or earth pressure acting on the tip excavator face plate at the time of propulsion pipe connection during propulsion,
A rod-like projecting rod that penetrates the propulsion tube wall and projects outward by a predetermined length through grout holes provided on both side surfaces of the propulsion tube, and an insertion hole at the projecting rod position on the inner side of the propulsion tube An inner distribution plate installed so as to be in contact with the inner wall surface of the pipe, an inner fixing bracket for fixing the protruding rod through the inner distribution plate, and a pipe provided with an insertion hole at the position of the protruding rod on the outer side of the propelling tube A cylindrical insertion tube is fixed to the outer distribution plate so as to cover the fitting hole on the outer distribution plate installed so as to contact the outer wall surface, and the front side surface of the insertion tube is reinforced from the outer distribution plate. Backing prevention support characterized by comprising a backing force support bracket integrated by reinforcing and fixing with a material, and an outer fixing bracket for fixing the end portion of the protruding collar protruding from the insertion tube of the backing force support bracket apparatus.

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