JP4448760B2 - Promotion method - Google Patents

Description

  The present invention relates to a propulsion method for constructing a pipe rod in the ground, and more particularly to a propulsion method using a pipe body formed by joining a pair of halved concrete segments.

  As a method for constructing a pipe rod in the ground, a propulsion method is known in which excavation is carried out while pushing the propulsion rod laterally into the ground from a vertical shaft erected in the ground. This is because a concrete pipe manufactured to a predetermined length at the factory is pushed in while being connected to the rear end of the propulsion pipe pushed in first, thereby constructing a pipe with the required length. It is going.

  Conventionally, most pipes constructed by such a propulsion method have a diameter of about 3 m or less. This is due to the fact that transportation becomes difficult when the diameter of the pipe body constructed at the factory and transported to the site exceeds 3 m. However, with the widespread use of common grooves in urban areas, it has become necessary to construct large-diameter pipes with the propulsion method. Therefore, Patent Document 1 discloses that a concrete segment having a shape obtained by dividing a tubular body into two in the circumferential direction is formed, and these two halved concrete segments are assembled into a tubular body. . The concrete segment thus divided can be transported by a trailer or the like even if it has a large diameter.

JP 2004-183289 A

  By the way, such a half-shaped concrete segment is manufactured in a factory and transported to the site by a trailer or the like, and then, at the site, as shown in FIG. One of the two is placed with the opening side up, and another concrete segment 2 is placed from above with the opening side down, and the two are joined together. The joint 3 of the tubular body 1 assembled in this way is positioned horizontally on the ground. When this tubular body 1 is lifted by a crane in this state, it is carried into the bottom of a shaft erected in the ground, and pushed laterally, the joint 3 of the tubular body 1 remains positioned horizontally on the ground. .

  However, when the tube 1 is buried in the ground, it is preferable in view of the strength of the tube 1 that the joint 3 is positioned at an angle of approximately 45 degrees with respect to the ground. After the body 1 is assembled, it must be rotated 45 degrees in the circumferential direction before being lifted by a crane. However, since this pipe body 1 is a heavy concrete product reaching 20 tons, for example, this rotating operation is not easy.

  The present invention has been made in view of the above circumstances, and in a propulsion method using a tubular body in which a pair of halved concrete segments are joined together, a simple apparatus configuration allows the tubular body after joining, which is a heavy object. It is an object of the present invention to provide a propulsion method capable of easily performing a rotating operation.

In the propulsion method according to claim 1, the propulsion pipe is pushed into the ground in the lateral direction, the pipe body is connected to the rear end of the pushed-in propulsion pipe, and the operation of pushing in is repeated. When the tube is constructed by joining a pair of halved concrete segments on the gantry, the outer peripheral surface of the tube and the two support surfaces of the gantry that can circumscribe the outer peripheral surface in the tube body is interposed a low friction material circumferentially to change the circumferential position of the junction portion of the tube body by rotating in, then rear end of the propulsion tube lifting the tubular body between the a carry-promoting method to be connected to the propulsion tube, the support surface of the frame is a low friction surface, the low friction material is interposed between the supporting surface of the pedestal and the outer peripheral surface of the tubular body The tape-shaped low friction material is in the longitudinal direction. Between the outer peripheral surface of the tubular body and the support surface of the gantry so as to be orthogonal to the axial direction of the tubular body, and with the rotation of the tubular body in the circumferential direction, the tubular body and the The tape-like low-friction material is slid along the longitudinal direction by sliding the tape-like low-friction material against the support surface which is the low-friction surface by the frictional force between the tape-like low-friction material. It is characterized by moving .

In the first aspect of the present invention, the low friction material is interposed between the outer peripheral surface of the tubular body and the support surface of the gantry, and the tubular body is rotated in the circumferential direction. Even if it exists, a pipe body can be easily rotated a predetermined angle with a simple apparatus structure. This makes it possible to construct a propulsion method using a large-diameter concrete pipe.
In addition, a low friction material is sandwiched between the outer peripheral surface of the tube body and the support surface of the gantry, and when the tube body is rotated in the circumferential direction, the support surface of the gantry is a low friction surface and is easy to slide. Since the outer peripheral surface of the concrete tube is difficult to slide, the tape-shaped low friction material slides on the support surface, and as the low friction material moves, the outer periphery of the low friction material and the tube A rotational force is given to the tube body by the frictional force between the surfaces. Therefore, even if the tube body is a heavy object having a large diameter, the tube body rotates with a small force. In this way, with a simple device configuration, the rotating work of the joined pipe body, which is a heavy object, can be easily performed.

The propulsion method according to claim 2 is the invention according to claim 1, wherein the angle formed by the lines orthogonal to the two support surfaces of the gantry is an acute angle, and 2 of the pair of halved concrete segments. After joining the pair of halved concrete segments so that the two joints are positioned horizontally, rotating the pipe body in the circumferential direction within a range where one of the joints does not contact the support surface. Features .

In the invention described in claim 2, since the pipe is constructed by joining the pair of halved concrete segments so that the joints are positioned horizontally, the joining work can be performed stably and easily. it can.
Since the angle formed by the lines orthogonal to the two support surfaces is set to be an acute angle, it is possible to prevent the joint from contacting the support surface when the tube is rotated 45 degrees in the circumferential direction. Is possible.

Jacking method according to claim 3 is the invention according to claim 2, wherein the rotating 45 degrees the tube body in the circumferential direction.

In the third aspect of the present invention, the low friction material is interposed between the outer peripheral surface of the tube body and the support surface of the gantry, and the tube body is rotated 45 degrees in the circumferential direction. Even with a body, the tube can be easily rotated by a predetermined angle with a simple device configuration. Thereafter, the tubular body with the joint at a 45 degree position can be lifted as it is, carried into the bottom of the shaft, and pushed into the ground, thereby increasing the strength of the tubular body buried in the ground.

The propulsion method according to claim 4 is the invention according to any one of claims 1 to 3, wherein one end of the chain of the small hoist is fixed to the outer peripheral surface of the tubular body, The end of the tube is fixed to the gantry, and the distance between the chain fixing portion of the tubular body and the chain fixing portion of the gantry is shortened by the small lifting machine, so that the tubular body is moved in the circumferential direction. It is made to rotate.

  According to the propulsion method of the present invention, it is possible to easily perform the rotating operation of the pipe body after joining, which is a heavy object, with a simple device configuration using a gantry and a low friction material.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the concrete pipe body used for the propulsion method according to the embodiment of the present invention will be described.
The concrete pipe body for propulsion pipe (hereinafter, also simply referred to as “pipe body”) 10 is configured by joining a pair of half-shaped concrete segments 12 and 12, but is used in the propulsion method. The method is the same as that of a tubular body integrally formed of concrete. That is, the pipe body (propulsion pipe) 10 is lifted by a crane, carried into the bottom of a vertical shaft erected in the ground, and then successively added to the rear end of the propulsion pipe pushed laterally. Then, the rear end of the joined pipe body 10 is further pushed by a jack or the like to push in the propulsion pipe, and this is sequentially extended to construct a pipe rod.

  The tube body 10 is provided with a collar (steel strip) 14 surrounding the end portion at the rear end side (the side pushed by the jack or the like, the left side in FIG. 1) protruding from the concrete main body 10a by a predetermined length. It has been. On the other hand, on the tip side (the side added to the propulsion pipe, the right side in FIG. 1), a small diameter portion 16 having an outer diameter smaller than the other is formed by a length substantially the same as the protruding length of the collar 14. When the pipe body 10 is added to the rear end of the propulsion pipe, the small diameter portion 16 of the front pipe body 10 and the collar 14 of the rear pipe body 10 are fitted together, and a gap is filled with a filler.

The pair of halved concrete segments 12, 12 are provided with a structure for joining and configuring the tubular body 10 as described below.
As shown in FIG. 2, in the concrete segments 12, 12, annular holes 20 that extend in the circumferential direction and open to the circumferential end faces (joint surfaces) 18, 18 are formed by the sheath 22. Thereby, when a pair of concrete segments 12 and 12 are joined, the corresponding annular holes 20 communicate with each other, and four circumferential holes 24 that pass through the tube body 10 are formed in this example. A part of the circulation hole 24 opens into a recess 26 on the outer peripheral surface of the concrete segment 12, 12, and an anchor 28 is provided in the recess 26. And after joining the joint surfaces 18 and 18 of the concrete segments 12 and 12, after inserting the PC tension | tensile_strength material 30 of PC steel materials etc. from the recessed part 26, tightening with a jack etc., by fixing to the anchor 28, two Tension is applied between the joint surfaces 18 and 18 of the concrete segments 12 and 12 and in the circumferential direction.

  The collar 14 is fixed so as to cover the half circumferences of the concrete segments 12 and 12 by embedding reinforcing bars welded to the collar 14 in the concrete. Concave portions are provided in the circumferential end portions of the concrete segments 12, 12, and the collars 14 are connected to each other by arranging a backing material in the concave portions and welding the end portions of the collars 14.

  As shown in FIG. 3, the opposing circumferential end faces 18 of the concrete segments 12, 12 are respectively provided with recesses 34 for receiving shear keys 32, and the shear keys 32 and the adhesive common to these recesses 34 are provided. And are attached. The main purpose of these shear keys 32 is to apply a shearing force acting between the joint surfaces 18 of the concrete segments 12 and 12 when propelling the pipe body 10 into the ground. For example, as shown in FIG. 4, both ends are formed into a truncated cone-shaped pin shape made of metal such as steel, resin, ceramics, or the like. Since the shear key 32 is also used for positioning when joining the concrete segments 12 and 12 at the same time, the taper taper 36 makes it easy for the shear key 32 to enter the recess 34. As shown in FIGS. 4A and 4B, shear keys 32 having different lengths are prepared and can be selected according to the situation. For example, a long thing is arrange | positioned in the recessed part 34 of the location initially positioned in the case of alignment, a short thing is arrange | positioned in the other recessed part 34, and work can be advanced smoothly by positioning sequentially.

  The recess 34 for accommodating the shear key 32 is formed in a key receiving member 38 embedded in the concrete at the circumferential end face 18 of the concrete segments 12, 12. That is, the key receiving member 38 is formed with a recess 34 in which a conical surface 40 having the same taper as the end of the shearing key 32 and a cylindrical surface 42 that accommodates an intermediate cylindrical portion of the shearing key 32 are formed. Has been. In this embodiment, the dimensional difference between the shear key 32 and the recess 34 of the key receiving member 38 is set to 0.1 mm or less. When a shearing force is applied between the joint surfaces 18, the shear key 32 is sheared. Only force is applied. A screw hole 44 is formed in the bottom of the recess 34 of the key receiving member 38. The key receiving member 38 is formed with an enlarged diameter portion 46 at the end portion on the side embedded in the concrete so that it can resist a force acting in the shearing direction or the drawing direction, and the pressure receiving area is also increased. It is illustrated. The key receiving member 38 can also be made of an appropriate material such as metal, resin, or ceramic.

Next, a propulsion method using the concrete pipe 10 will be described with reference to FIGS. In these drawings, the tube body 10 is illustrated in a simplified manner.
First, the halved concrete segment 12 constituting the tubular body 10 is manufactured in a factory and transported to the site by a trailer or the like.

Next, at the site, a pair of halved concrete segments 12 and 12 are joined to form the tubular body 10, and then the tubular body 10 is rotated 45 degrees in the circumferential direction. This will be described in detail below.
5 and 6 are views showing a gantry used for assembling and rotating the tube body 10, in which FIG. 5 is a front view and FIG. 6 is a side view. The gantry 50 includes a base 51 and two support portions 52 fixed on the base 51. Both support parts 52 are formed in a rail shape, and are arranged in parallel with a gap therebetween. A support surface 53 made of an inclined plane extends linearly in parallel with an interval between the upper portions of the support portions 52, and the tubular body 10 is supported by these two support surfaces 53. An angle α formed by a line perpendicular to the support surface 53 is an acute angle, for example, set to about 70 degrees. In addition, the support part 52 and the support surface 53 may not be extended continuously, but may be separated with a space therebetween.

First, as shown in FIG. 7, the mount 50 is installed near the vertical shaft into which the pipe body 10 is carried.
Next, as shown in FIG. 8, a smooth plate 54 having a smooth surface made of a tin plate or the like is fixed on each support surface 53 of the gantry 50 using an adhesive or the like, and grease is applied to the surface of the smooth plate 54. To make a low friction surface.
Next, as shown in FIG. 9, one end of a tape-shaped low friction material 55 made of a material having a low coefficient of friction such as Teflon (registered trademark) is placed on each support surface 53. The low friction material 55 is provided so as to extend in the circumferential direction of the tubular body 10. A plurality of the low friction materials 55 are arranged at intervals in the axial direction of the tube body 10. The width of the low friction material 55 is set to about 30 to 60 cm, for example.
Next, as shown in FIG. 10, one of the halved concrete segments 12 constituting the tube body 10 is placed on the support surface 53 of the gantry 50 with the opening side facing upward. In this way, one end of the low friction material 55 is interposed between the smooth plate 54 on the support surface 53 and the outer peripheral surface of the concrete segment 12.

Next, as shown in FIG. 11, another concrete segment 12 constituting the pipe body 10 is placed from above with the opening side facing down, and the joint surfaces 18, 18 of both the concrete segments 12, 12 are aligned.
Next, as shown by the arrows in FIG. 12, after inserting a PC tendon such as PC steel in the circumferential direction of the concrete segments 12, 12, and tightening the PC tendon with a jack or the like as shown in FIG. By fixing to the anchor 28, the two concrete segments 12, 12 are firmly integrated. In addition, when the concrete segments 12 and 12 are joined, a shear key is attached and a collar is connected. The joint portion 57 of the tubular body 10 assembled in this way is positioned horizontally on the ground.

  Next, as shown in FIGS. 14 and 15, both ends of the chain 61 of the small hoist 60 are fixed to the outer peripheral surface of the tubular body 10 and the base 51 of the mount 50, respectively, and the distance between both fixing portions is reduced. The tube 10 is rotated 45 degrees in the circumferential direction indicated by the arrow. At this time, a low friction material 55 is interposed between each smooth plate 54 of each support surface 53 of the gantry 50 and the outer peripheral surface of the tube body 10, but grease is applied to the surface of the smooth plate 54. However, since the outer peripheral surface of the concrete tube 10 is difficult to slide, the tape-like low friction material 55 slides and moves on the smooth plate 54 of the support surface 53. As the low friction material 55 moves, a rotational force is applied to the tube body 10 by the frictional force between the low friction material 55 and the outer peripheral surface of the tube body 10. Therefore, even if the tube body 10 is a heavy object of about 20 tons, for example, the tube body 10 rotates with a small force. In addition, you may make it rotate the pipe body 10 to the circumferential direction using a crane instead of the small lifting machine 60. FIG. That is, the wire of a crane is fixed to the outer peripheral surface of the tubular body 10, and the tubular body 10 is rotated by pulling this wire in the rotation direction.

Next, as shown in FIG. 16, the pipe body 10 is lifted by a crane in this state, and is carried into the bottom of a shaft erected in the ground.
Next, as shown in FIG. 17, the tube body (propulsion tube) 10 is pushed into the underground 70 while being connected to the rear end of the tube body 10 that has been pushed in first, so that a pipe rod having a necessary length is obtained. Will continue to build. The pipe body 10 is pushed horizontally into the underground 70 by a jack 73 provided between the bearing wall (reaction wall) 72 of the shaft 71 and the pipe body 10 carried in. The tube 10 buried in the ground in this way has a joint portion positioned at an angle of approximately 45 degrees with respect to the ground. In addition, the tubular body 10 is rotated 45 degrees alternately in the opposite direction so that the joint portion does not continue in the axial direction of the tubular body 10 and is carried into the shaft 71.

  In such a propulsion method, the pipe body 10 is configured by joining the pair of half-shaped concrete segments 12 and 12 so that the joint portion 57 is positioned horizontally, so that the joining work can be stably performed. It can be done easily. And the tape-shaped low friction material 55 is pinched | interposed between the outer peripheral surface of the tubular body 10, and the smooth surface 54 on the support surface 53 of a mount frame, and the smooth surface 54 of the mount frame 10 is made into the low friction surface. While it is easy to slide, the outer peripheral surface of the concrete tubular body 10 is difficult to slide, so that the low friction material 55 slides on the smooth surface 54 and moves along with the movement of the low friction material 55. A rotational force is applied to the tube body 10 by the frictional force between the tube body 10 and the outer peripheral surface of the tube body 10. Therefore, even if the tube body 10 is a heavy object having a large diameter, the tube body 10 rotates 45 degrees in the circumferential direction with a small force. Thus, with a simple device configuration using the gantry 50 and the low friction material 55, it is possible to easily rotate the tubular body 10 after joining, which is a heavy object. Thereafter, the tubular body 10 with the joint portion 57 positioned at 45 degrees can be lifted as it is, carried into the bottom of the shaft and pushed into the ground, and thereby the strength of the tubular body 10 buried in the ground. Will increase.

  In addition, since the support surface 53 of the gantry 50 is composed of two surfaces extending linearly along the axis of the tube with a space between each other, the tube 10 is supported at two points, so a pair of concrete segments The tube body 10 can be stably supported even when the members 21 and 21 are joined and assembled, and can also be stably supported when the tube body 10 is rotated in the circumferential direction. Further, since the two support surfaces 53 and 53 are inclined to face each other, the tube body 10 can be supported more stably and can be rotated. Furthermore, since the angle formed by the lines orthogonal to the two support surfaces 53, 53 is set to be an acute angle of about 70 degrees, when the tubular body 10 is rotated 45 degrees in the circumferential direction, the joint portion It is possible to prevent 57 from contacting the support portion 53.

  In the above-described embodiment, the tape-shaped low friction material 55 is sandwiched between the outer peripheral surface of the tube body 10 and the support surface 53 of the gantry 50, and the tube body 10 is formed using the support surface 53 as a low friction surface. However, instead of this, a low friction material made of a material having a low friction coefficient such as Teflon (registered trademark) is simply fixed on the support surface 53 of the gantry 50 and the tube body 10 is rotated. It may be.

  Alternatively, a low friction material containing a polymer that gels when moisture is absorbed is provided on the outer peripheral surface of the tube body 10, and a smooth plate 54 having a smooth surface such as a tin plate is provided on the support surface 53 of the gantry 50. The support surface 53 may be a smooth surface and the tube body 10 may be rotated. In the case of using such a low friction material, water is sprayed by a sprayer or the like, and if moisture is given to the low friction material to gel, the frictional force of the low friction material is reduced. Therefore, the tube body 10 is easily rotated. be able to. Here, the “polymer that gels when moisture is absorbed” refers to a polymer compound that gels when moisture is absorbed, and includes, for example, a polymer compound of a crosslinked polyacrylate. The “low friction material” is formed by mixing a polymer that gels when it absorbs moisture into a nonwoven fabric, cloth, fiber, rubber, paper, foamed urethane, or the like. Such a low-friction material extends, for example, in a band shape in the circumferential direction of the tubular body 10 within a range in contact with the support surface 53 on the outer circumferential surface of the tubular body 10, and is spaced in the axial direction of the tubular body 10. Multiple rows are pasted.

It is a side view of the concrete pipe body used for the propulsion method according to the embodiment of the present invention. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG. It is sectional drawing which shows a shear key and a key receiving member, (a) is a long shear key, (b) shows a short shear key. It is a figure which shows the mount used for the propulsion construction method which concerns on embodiment of this invention, Comprising: It is a front view. FIG. It is a figure for demonstrating the propulsion construction method which concerns on embodiment of this invention, Comprising: It is a front view which shows a mount installation process. It is a front view of the support part which shows the installation process of a smooth plate equally. It is a front view which shows the installation process of a low friction material equally. It is a front view which shows the mounting process of one concrete segment same as the above. It is a front view which shows the mounting process of the other concrete segment. It is a front view which shows the insertion process of the PC tendon material to a concrete segment. It is a front view which shows the fastening process of the PC tendon in a concrete segment. It is a front view which shows the rotation process of a tubular body similarly. It is a side view which shows the rotation process of a tubular body similarly. It is a front view which shows the lifting process of a tubular body. It is a side surface which shows the pushing process of a tubular body. It is a front view which shows the assembly state of a tubular body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Concrete pipe body 12 Half split concrete segment 50 Mounting base 53 Support surface 57 Joint part

Claims (4)

When constructing a pipe rod of the required length by pushing the propulsion pipe horizontally into the ground, connecting the pipe body to the rear end of the pushed propulsion pipe and pushing it in repeatedly ,
After configuring the pipe body by joining concrete segments of the pair of half-shaped on pedestal, lower between the outer peripheral surface of the tubular body and two support surfaces of the frame that can be circumscribed to the outer peripheral surface the friction material is interposed to change the circumferential position of the junction portion of the tube body by rotating the tube body in the circumferential direction, then the propulsion tube is loaded into the rear end of the propulsion tube lifting the tubular body A propulsion method connected to
The support surface of the gantry is a low friction surface,
The low friction material is a tape-like material sandwiched between the outer peripheral surface of the tubular body and the support surface of the gantry,
The tape-shaped low friction material is disposed so as to be sandwiched between the outer peripheral surface of the tubular body and the support surface of the gantry so that the longitudinal direction thereof is orthogonal to the axial direction of the tubular body,
The tape-shaped low-friction material with respect to the support surface that is the low-friction surface due to the frictional force between the tube and the tape-shaped low-friction material as the tube rotates in the circumferential direction. A propulsion method characterized in that the tape-like low friction material is moved along the longitudinal direction by sliding the tape . The angle formed by the lines orthogonal to the two support surfaces of the gantry is an acute angle,
After joining the pair of halved concrete segments so that the two joints of the pair of halved concrete segments are positioned horizontally, one of the joints does not contact the support surface. The propulsion method according to claim 1, wherein the tubular body is rotated in a circumferential direction . The propulsion method according to claim 2 , wherein the pipe body is rotated 45 degrees in the circumferential direction . One end of the chain of the small lifting machine is fixed to the outer peripheral surface of the tube, the other end is fixed to the frame, and the chain fixing unit of the tube is fixed to the frame by the small lifting machine. The propulsion method according to any one of claims 1 to 3, wherein the tubular body is rotated in a circumferential direction by reducing a distance between the fixed portion of the chain .

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