JP4156016B2 - Sealing means used for pipeline embedding methods - Google Patents

Description

  The present invention relates to a sealing means used in a pipeline burying method for burying a pipeline such as a water pipe or a gas pipe in a natural ground.

  Conventionally, when a pipeline such as a water pipe or a gas pipe is embedded in a natural ground, a sheath pipe is previously disposed in the natural ground and the pipeline is propelled inside the sheath pipe. In such a method, shafts are excavated at positions corresponding to both ends in the axial direction of the pipeline to be buried, and the sheath pipe is arranged so as to connect these shafts. The buried pipeline is formed by propelling a single pipe of a predetermined length toward the other shaft while sequentially connecting end portions in the axial direction within one shaft. Conventionally, when propelling a pipeline inside a sheath tube, in order to reduce friction between the outer peripheral surface of the pipeline and the inner peripheral surface of the sheath tube, an insulator having a plurality of blades radially extending outward in the radial direction is provided. The pipeline was propelled by attaching it to the outer peripheral surface of a single tube and sliding the blades of this insulator relative to the inner peripheral surface of the sheath tube.

Even when an insulator is attached to a single pipe, the frictional resistance is small while the number of single pipes connected is small, so that the pipeline can be driven relatively smoothly. However, as construction progresses and the number of connected single pipes increases, the frictional resistance generated between the insulator and the inner surface of the sheath pipe gradually increases, making it difficult to smoothly promote the pipeline.
Moreover, the single pipe which comprises a pipeline is sequentially inserted in a sheath pipe at the starting shaft side. Moreover, an insulator is often attached to the outer peripheral surface of the single pipe constituting the pipeline in order to prevent the single pipe and the sheath pipe from coming into direct contact. For this reason, even if a single seal member that seals the inner surface of the sheath tube and the outer peripheral surface of the pipeline is provided, if the insulator passes through the seal member, a gap is formed between the pipeline and the seal member. Liquid leaks out of the shaft.

Therefore, in the present invention, even when the number of connected single pipes increases, the sealing means used in the pipeline burying method that can smoothly propel the pipeline, even if the insulator passes through the shaft, It is possible to provide a sealing means that can surely prevent liquid from leaking out.

(1) The sealing means according to the present invention injects a predetermined amount of liquid into a sheath pipe connecting the shafts formed in the natural ground, and propels a pipeline in which an insulator is mounted in the sheath pipe. a sealing means for use in allowed to embedding the pipeline the natural ground by a mounting portion for mounting on an end portion in the axial direction of the sheath tube, the pipeline and the body that can pass through the inside The sealing member that prevents the liquid injected into the sheath pipe from leaking from between the outer peripheral surface of the pipeline is multilayered in the axial direction of the sheath pipe. And the spacing between the multilayer seal members is set to be larger than the width of the insulator .

According to the pipeline embedding method using the sealing means according to the present invention, since the pipeline to be propelled is suspended by the liquid, it is possible to prevent the pipeline and the sheath tube from sliding directly. For this reason, since it is only necessary to propel the pipeline floating the liquid, it can be smoothly propelled with a small force. Therefore, it is not necessary to install a large propulsion device in the shaft, and the cost required for construction can be reduced and the construction period can be shortened.
In the above pipeline embedding method, single pipes constituting the pipeline are sequentially inserted into the sheath pipe on the start shaft side. Moreover, an insulator is often attached to the outer peripheral surface of the single pipe constituting the pipeline in order to prevent the single pipe and the sheath pipe from coming into direct contact. For this reason, even if a single seal member that seals the inner surface of the sheath tube and the outer peripheral surface of the pipeline is provided, if the insulator passes through the seal member, a gap is formed between the pipeline and the seal member. Liquid leaks out of the shaft.
In this regard, according to the present invention, by providing the sealing members in multiple layers, even if the insulator passes through the inner sealing member close to the sheath tube and liquid leaks from the sealing member, the outer sealing member remains liquid. As a result, the liquid can be reliably prevented from leaking into the shaft.

Note that the sealing effect of the layers of the sealing member can be improved by increasing the number of layers. On the other hand, the frictional resistance generated between the seal member and the pipeline is increased. For this reason, smooth promotion may be hindered. The number of layers of the sealing member may be an appropriate number in consideration of the balance between the sealing effect and smooth propulsion.

(2) Further, in the above-described (1), a drainage port for discharging the liquid injected into the sheath pipe is provided on the sheath pipe side from the attachment position of the seal member. The drain outlet is provided at a position higher than the center.

(3) Further, in the above (1) or (2), a drain port for discharging the liquid injected into the sheath pipe is provided in the trunk portion from the attachment position of the seal member. The drain port is provided on the side, and the liquid floats up the pipeline and prevents the lower end of the insulator attached to the outer peripheral surface of the pipeline from coming into contact with the lower end of the sheath tube. The insulator mounted on the outer peripheral surface of the pipeline is formed at a height that maintains the liquid level within a range in which the insulator can be prevented from being pressed against the top surface of the sheath tube. .

  According to the sealing means having such a configuration, it is possible not only to float the pipeline and prevent the lower end from rubbing against the sheath tube, but also to prevent the upper end from sliding with great friction on the top surface of the sheath tube. For this reason, the smooth propulsion of the pipeline can be reliably performed inside the sheath tube, and the leakage of the liquid that floats the pipeline by the sealing means can be minimized.

According to the pipeline embedding method using the sealing means according to the present invention, since the pipeline to be propelled is suspended by the liquid, it is possible to prevent the pipeline and the sheath tube from sliding directly. According to the present invention, since the seal members are provided in multiple layers, even if the insulator passes through the inner seal member close to the sheath tube and liquid leaks from the seal member, the outer seal member is liquid. As a result, the liquid can be reliably prevented from leaking into the shaft.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a state in which a pipeline 2 is embedded by a pipeline embedding method in which a sealing means according to an embodiment of the present invention is used . In this pipeline burying method, shafts are excavated at positions corresponding to both ends of the pipeline 2 to be embedded, the shafts are connected to each other by the sheath tube 1, and the pipeline 2 is propelled inside the sheath tube 1. Thus, the pipeline 2 is buried. Further, a single long pipeline 2 is formed by connecting the end faces in the axial direction of the single tubes 3... 3 having a predetermined length. Although a propulsion device that propels the pipeline 2 is not shown, examples of the propulsion device include a cylinder device and a winch device. Further, this propulsion device is not limited to the one installed in the starting shaft A and pressing the pipeline toward the reaching shaft B. The propulsion device is installed in the reaching shaft B and draws the pipeline to the reaching shaft B. Things may be used.

  The vertical shaft excavated on the right side of FIG. 1 is a start shaft A that is a starting point of the pipeline 2 to be propelled, and the vertical shaft formed on the left side is a reaching shaft B to which the pipeline 2 to be propelled is reached. . These side walls of the shafts A and B are connected to each other by a sheath tube 1. The sheath pipe 1 serves to protect the pipeline 2 to be buried later from earth and sand of the natural ground G, and the pipeline 2 can be propelled in the axial direction inside the pipeline 2. A tube having an inner diameter slightly larger than the outer diameter of 2 is used. The sheath tube 1 is configured by connecting single tubes 1A... 1A having a predetermined length in a plurality of axial directions.

  In addition, a water tank T is installed on the ground surface. The water tank T is for supplying water W to the inside of the sheath tube 1 and is connected to a sealing means 20 described later by a hose 15. In order to prevent the water W injected into the sheath pipe 1 from leaking into the shaft, seal means 10 and 20 are provided at the end portion on the start shaft A side and the end portion on the end shaft B side, respectively. Is provided. The sealing means 20 on the start shaft A side has a special structure that allows the pipeline 2 to be inserted into the inside of the sheath tube 1, and the sealing means 20 will be described in detail later. On the other hand, the sealing means 10 on the reaching shaft B side prevents the water W inside from leaking to the shaft by sealing the opening at the end of the sheath tube 1. In addition, the sealing means 10 on the reaching shaft B side is not particularly limited in its structure as long as the water W can be prevented from leaking to the shaft.

  The pipeline 2 is connected by a propulsion device (not shown) installed in the start shaft A, with single pipes 3... 3 of a predetermined length sequentially connected in the axial direction in the start shaft A excavated on the right side of the figure. The rear end of the single pipe 3 is pressed and propelled toward the reaching shaft B, and this operation is repeated until the leading single tube 3 reaches the reaching shaft B. At this time, since the water W is injected into the sheath pipe 1, the pipeline 2 inserted into the sheath pipe 1 from the start shaft A is floated by the buoyancy of the water W. For this reason, according to the embedding method, the pipeline 2 can be propelled in the axial direction with a small propulsion force. In addition, the front end opening of the single pipe 3 constituting the front end of the pipeline 2 is closed by the lid body 4 to prevent the water W from entering the inside of the pipeline 2. As a result, the pipeline 2 is floated in the sheath tube 1.

  Further, the single pipes 3... 3 constituting the pipeline 2 have insulators 6... 6 attached to the outer peripheral surfaces thereof at both axial positions. The insulators 6 ... 6 are formed in a ring shape and are attached to the outer peripheral surface of the single tubes 3 ... 3, and a plurality of blades 8 ... 8 extending radially outward from the attachment portion 7 in the radial direction. It is composed of The insulators 6 ... 6 serve to protect the single tubes 3 ... 3 by preventing the single tubes 3 ... 3 from rubbing against the inner surface of the sheath tube 1 when the pipeline 2 is propelled. The frictional resistance is reduced by reducing the contact area with the inner surface of the sheath tube 1.

  2 and 3 show details of a state in which the single pipe 3 constituting the tip of the pipeline 2 is inserted into the sheath pipe 1 from the start shaft A.

  A protective wall 40 that prevents the natural ground G from collapsing is installed on the side surface of the start shaft A over the entire circumference of the side wall of the start shaft A. A circular opening is formed in the protective wall 40 at a position where the sheath tube 1 is disposed, and the end of the sheath tube 1 slightly protrudes from the opening to the inside of the start shaft A. Sealing means 20 is attached to the end face of the sheath tube 1 to prevent the water W injected into the start shaft A from leaking out into the sheath tube 1.

  The sealing means 20 includes a donut-shaped mounting portion 22 attached to the end face of the sheath tube 1 and a cylindrical body portion 25 extending from the mounting portion 22 in the axial direction of the sheath tube 1 toward the inside of the start shaft A. The single pipes 3... 3 constituting the pipeline 2 are guided to the inside of the sheath pipe 1 while water W injected into the sheath pipe 1 is stopped. A plurality of bolt holes are formed in the mounting portion 22 so as to be arranged almost evenly on the entire circumference, and bolts are passed through the respective bolt holes, and the sealing means 20 is attached to the end surface of the sheath tube 1 by these bolts. It is attached.

  On the other hand, the body portion 25 is formed of a cylindrical body communicated with the sheath tube 1, and has a diameter that is substantially the same as the inner diameter portion of the mounting portion 22. The shell 25 side of the trunk portion 25 communicates with the sheath tube 1, while the start shaft A side is open, and the single tubes 3... 3 constituting the pipeline 2 are inserted from this opening portion. 1 Guided inside. Rubber packings 27 and 29 are attached to the inner peripheral surface of the body portion 25 as seal members for sealing between the outer peripheral surfaces of the single pipes 3 to 3 of the pipeline 2 to be inserted. The rubber packings 27 and 29 are provided in layers in the axial direction at two locations, that is, the end face portion of the body portion 25 and the substantially central portion in the axial direction. Each rubber packing 27 and 29 is formed in a donut shape, and the outer peripheral portion thereof is bolted to the inner peripheral surface portion of the body portion 25 and attached. On the other hand, the inner peripheral portions of the rubber packings 27 and 29 are formed so that the diameter thereof is slightly smaller than the outer diameter of the single tubes 3.

  In addition, a rectangular drainage port 32 that communicates the inside and outside of the body portion 25 is formed in the body portion 25 at a height H from the lower end thereof. The drain port 32 discharges the water W in the sheath tube 1 to the outside in order to prevent the water level of the water W injected into the sheath tube 1 from exceeding a predetermined water level. If there is much water W injected into the sheath tube 1 and the water level is too high, the pipeline 2 is propelled in the upper portion inside the sheath tube 1. In such a case, the insulators 6... 6 attached to the single tubes 3... 3 are rubbed against the inner peripheral surface of the upper portion of the sheath tube 1, thereby hindering smooth propulsion. Further, as the construction progresses and the number of single tubes 3... 3 connected in the sheath tube 1 increases and the pipeline 2 becomes longer, the ratio of the pipeline 2 to the inner volume of the sheath tube 1 increases. Then, the water level rises inside the sheath tube 1, the pipeline 2 is pushed upward, and the upper ends of the insulators 6 ... 6 come into contact with the upper part of the inner peripheral surface of the sheath tube 1. The drain port 32 prevents the water level of the water W injected into the sheath tube 1 from rising above a predetermined level in order to prevent such problems.

  If the position where the drain port 32 is formed is too low, the pipeline 2 cannot be sufficiently lifted, and the lower end of the insulators 6... . Even in such a case, the frictional resistance increases and the pipeline 2 cannot be smoothly driven. For this reason, the drain port 32 is preferably provided at a position slightly higher than the center. Thereby, the pipeline 2 can be smoothly propelled without sliding either the upper end or the lower end of the insulators 6... 6 on the inner peripheral surface of the sheath tube 1.

  Further, guide rollers 35 for supporting the lower surfaces of the single pipes 3 ... 3 so that the single pipes 3 ... 3 of the pipeline 2 to be inserted can be smoothly inserted into the start shaft A side of the trunk 25. Two 35 are attached. From the lower part of the trunk | drum 25, the circular arc-shaped board | plate material 36 to which the guide rollers 35 and 35 are attached protrudes to the axial direction outer side. The guide rollers 35 are attached at both ends in the circumferential direction of the plate member 36 so that the upper ends thereof extend toward the central axis of the body portion 25. The single pipes 3... 3 are smoothly inserted into the sheath pipe 1 from the sealing means 20 by the two guide rollers 35.

  A bracket 37 protruding upward from the outer peripheral surface is provided on the upper portion of the body portion 25 so that the sealing means 20 can be suspended and moved by a hook.

  By attaching the sealing means 20 having such a configuration to the end portion of the sheath tube 1, as shown in FIG. 4, the single tubes 3 ... 3 can be formed without leaking the water W injected into the sheath tube 1 to the start shaft A. It can be inserted into the sheath tube 1 sequentially. FIG. 4 shows a state in which the single pipe 3 constituting the tip of the pipeline 2 is inserted into the sheath pipe 1 from the sealing means 20.

  FIG. 4A shows a state in which the single tube 3 having the tip is inserted to some extent in the axial direction, and the next single tube 3 is connected to the rear end in the axial direction. Further, the insulator 6 attached to the rear portion of the single tube 3 forming the tip is not yet inserted into the sealing means 20 and is located outside the sealing means 20. In this state, the water W injected into the sheath tube 1 is generally sealed by the rubber packing 27 attached to the inside.

  Then, the pipeline 2 to which the single pipes 3 and 3 are connected is pressed toward the arrival shaft B (left side in FIG. 4) by the starting shaft A, and further inserted into the sheath tube 1 from the sealing means 20. Then, the insulator 6 attached to the rear part of the single tube 3 forming the tip is pushed between the inner peripheral surface of the outer rubber packing 29 and moved between the inner rubber packing 27 and the outer rubber packing 29 (see FIG. 4 (b)). At this stage, the inner rubber packing 27 seals between the body portion 25 and the outer peripheral surface of the single tube 3, and the water W injected into the sheath tube 1 remains inside the inner rubber packing 27. .

  Further, when the pipeline 2 is pressed and inserted into the sheath tube 1 from the sealing means 20, the insulator 6 pushes away the inner peripheral portion of the inner rubber packing 27, and as shown in FIG. 27 to the sheath tube 1 side. When the insulator 6 passes through the rubber packing 27, a gap is formed between the inner peripheral portion of the rubber packing 27 and the outer peripheral surface of the single tube 3. For this reason, the water W injected into the sheath tube 1 leaks from the inner rubber packing 27 and is discharged into a space formed between the inner rubber packing 27 and the outer rubber packing 29. However, the discharged water W is sealed by the outer rubber packing 29 and is reliably prevented from leaking from the sealing means 20 to the starting shaft A. As a result, the propulsion device installed in the start shaft A and the worker working in the start shaft A are not obstructed by the leakage of the water W injected into the sheath tube 1 and can be safely performed. Work can be done.

  As described above, the rubber packing is attached to two locations in the axial direction of the sheath tube, and the seal member is formed so as to have two layers. However, the present invention is not limited to forming the seal member in two layers. You may form in. As the number of layers of the sealing member increases, the frictional resistance generated between the sealing member and the pipeline inserted from the sealing means increases, but it is possible to reliably prevent the water injected into the sheath tube from leaking to the outside. . In addition to the rubber packing, a resin sealing material or the like may be used as the sealing member.

  Further, as the liquid to be injected into the sheath tube, an antifreeze or other liquid may be used in addition to water. As this liquid, an appropriate liquid may be selected in accordance with the environment of the construction site and the type of pipeline to be used for embedding.

Explanatory drawing which shows a mode that the pipeline is embed | buried by the pipeline burying method in which the sealing means concerning one Embodiment of this invention is used . The figure which shows the state in which the single pipe which comprises the front-end | tip of a pipeline was inserted in the sheath pipe from the sealing means in the starting shaft. The figure which looked at the single pipe of FIG. 2 from the rear end side. The figure which shows a mode that the insulator with which the single pipe | tube was mounted | worn passes the rubber packing of a sealing means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheath pipe 2 Pipeline 3 Single pipe 6 Insulator 10, 20 Sealing means 27, 29 Rubber packing (seal member)

Claims (3)

With injected therein a predetermined amount of liquid into the sheath tube to contact shafts each other is formed in the natural ground, allowed to embedding the pipeline this insulator in the sheath tube is allowed to promote the pipeline mounted in the natural ground A sealing means used at the time, comprising: an attachment portion to be attached to an axial end portion of the sheath tube; and a trunk portion through which the pipeline can pass, and an inner surface of the trunk portion A seal member for preventing the liquid injected into the sheath pipe from leaking from between the outer peripheral surface of the pipeline is attached so as to be multilayered in the axial direction of the sheath pipe, and the multilayer seal sealing means, characterized in that the spacing between the members is set to be greater than the width of the insulator. In the body portion, a drain outlet for discharging the liquid injected into the sheath pipe is provided on the sheath pipe side from the attachment position of the seal member, and the drain outlet is provided at a position higher than the center. The sealing means according to claim 1, wherein: The trunk is provided with a drain outlet for discharging the liquid injected into the sheath pipe on the side of the sheath pipe from the attachment position of the seal member. The drain outlet allows the liquid to float up the pipeline. The insulator attached to the outer peripheral surface of the pipeline is prevented from coming into contact with the lower end of the sheath tube while the insulator attached to the outer peripheral surface of the pipeline is pressed against the top surface of the sheath tube. 3. The sealing means according to claim 1, wherein the sealing means is formed at a height that maintains the liquid level within a range in which the liquid can be prevented.

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