JPH04231785A - Pipeline laying method - Google Patents

Abstract

PURPOSE:To lessen an occupation area required for joining work of a base end portion of a pipeline to a new pipe and to facilitate welding for the joining. CONSTITUTION:A post 2 is erected straight on a bank 7 on one side and a pipe supporting base 1 including a welding stand 3, which can be raised and lowered, provided on the said post 2. A new pipe 5, which is lifted up with a crane 6, is welded to a base end portion 4 of a pipeline 10, which is solidified by means of the said supporting base 1, and join together with the axis in a vertical condition. The pipeline 10 formed by joining is moved to a specified location. The pipeline 10 is laid by repeating the process.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipeline installation method for installing a pipeline formed by joining a plurality of pipes.

0002

BACKGROUND OF THE INVENTION A conventional pipeline laying method is as described in, for example, Japanese Unexamined Patent Publication No. 2-8108.
On one land such as a river or sea where a pipeline is to be laid, the pipe is moved horizontally from the pipe supply source to the inclined feeding path by rolling it or using a truck with a jack, etc. one end of the pipe is brought into contact with the base end of a pipeline installed with its axis horizontal, the abutting part is joined by welding, and the tip of the pipeline is pulled toward a predetermined position; The other end of the joined pipe is the base end of a new pipeline.

[0003]The steps of joining and moving the pipes are repeated to construct a pipeline from one shore of a river or sea to a predetermined position.

0004

[Problems to be Solved by the Invention] However, in the conventional pipeline laying method, since the base end of the pipeline to be joined and the axis of the pipe are held horizontally, the land area where the joining work is performed is difficult. This method requires a large working area, and there is a problem in that the longer the pipes to be joined, the larger the working area is required to carry out the joining work.

[0005] Furthermore, in order to carry out welding while fixing the base end of the pipeline to be joined and the axis of the pipe in a horizontal state, it is said that welding techniques in all positions that require a high level of skill are required. There are also problems. The present invention has been made with attention to the above-mentioned problems, and it reduces the area occupied by joining a new pipe to the base end of a pipeline, and further reduces the welding work required for the joining. The purpose is to make your work easier.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the pipeline laying method of the present invention includes adding a new pipe to the base end of the pipeline and moving the distal end of the pipeline to a predetermined position. In a pipeline laying method in which the base end of the pipeline is stretched upward, the base end of the pipeline is supported upward, and the lower end of a new pipe whose axis is oriented vertically is welded and joined to the upper end of the base end. It is characterized by

[0007]

[Operation] While joining the lower end of a new pipe to the base end of the pipeline with its axis facing up and down, the series of pipelines formed by the joining has a predetermined radius of curvature below the joining position. move it toward a predetermined position while bending it. At this time, the predetermined radius of curvature needs to be set smaller as the height from the pipeline installation position to the base end is lower. to ensure that the pipe does not bend beyond the elastic deformation of the pipe being used.

[0008] Furthermore, since the base end of the pipeline and the new pipe are joined with their axes up and down, the working area occupied by the joining work is not affected by the length or diameter of the pipe, and is Only the area necessary to install the end and the device for vertically supporting the new pipe is required. Furthermore, since the welding work performed for the above-mentioned joining is performed on the horizontal abutting part between the base end of the pipeline with the axis up and down and the new pipe, the welding work is performed from a horizontal position. The well-known technology for welding steel pipe piles can be applied as is.

[0009]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. This embodiment is an example in which a pipeline is laid at the bottom of a river. First, as shown in FIG. 1, a pipe support stand 1 is installed on one bank 7 side of a river where a pipeline 10 is to be laid. The pipe support stand 1 consists of a post 2, a welding stand, and an auxiliary stand 9. The post 2 is built on land on the shore 7 side with its axis vertically, and one end 3a of the welding stand 3 is mounted vertically on the post 2. The welding stand 3 is movably fixed and extended horizontally in the pipeline laying direction,
Further, the other end 3b of the welding stand 3 is provided with a gripping part 3c for vertically gripping the first pipe 4 forming the base end of the pipeline 10, and a new pipe 5 is provided above the welding stand 3. An auxiliary stand 9 having a holding part for supporting the shaft with its axis up and down is fixed at one end to the post 2 so as to be movable up and down, and extends in the pipeline laying direction.

After installing the pipe support 1 as described above, as shown in the flowchart of FIG. 3, the pipe is lifted and moved from a pipe supply source (not shown) using a crane 6.
The pipe is held by the gripping part 3c of the welding stand 3 with the axis up and down, and the upper end of the pipe is attached to the pipeline 10.
(Step 1). At this time, the welding stand 3 is moved up and down along the post 2 in advance within the range of flexure due to elastic deformation of the pipes 4 and 5 to be joined.
Welding stand 3 is installed so that pipeline 10 made of pipes joined along the river bed to be laid has a predetermined radius of curvature.
Determine the height of the installation location. For example, if the wall thickness of the pipe is thick and the elastic deformation is small, the welding stand 3 is installed at a higher position (the position indicated by the dotted line in FIG. 1) so that the radius of curvature becomes larger. Note that during pipe forming, the corners of the outer periphery of both ends of all pipes used for laying are chamfered for welding.

Next, a new pipe 5 is lifted from a pipe supply source (not shown) by a crane 6 serving as a lifting means.
The pipe 5 is moved above the base end 4 fixed to the welding stand 3 (step 2). Subsequently, as shown in FIG. 2, the newly lifted pipe 5 is lowered to bring the lower end of the pipe 5 into contact with the base end portion 4 (step 3). At this time, the new pipe 5 is supported by a holding portion provided on the auxiliary stand 9 to maintain the abutting state.

Next, an automatic welding device 11 that can move horizontally along the outer circumference of the pipe 5 is installed on the outer circumference of the lower end of the pipe 5, and the tip 11a of the welding device 11 is attached to the abutted pipeline. By moving the distal end portion 11a of the welding device 11 along the corresponding contact portion toward the contact portion between the base end portion 4 of the pipe 10 and the new pipe 5, the contact portion is moved while maintaining a horizontal posture. Weld the base end 4 and the new pipe 5
(Step 4). Note that the horizontal welding method is
Japanese Unexamined Patent Publication No. 51-26315 and Utility Model Application No. 55-1657
A known horizontal welding method described in Japanese Patent No. 85 and the like can be employed.

When the connection between the base end 4 and the abutting part of the new pipe 5 is completed, the welding device 11 is removed, and while the upper end of the pipe 5 is supported by the crane 6, the gripping part 3c of the welding stand 3 is lifted. Loosen the pipe 5 and move the pipe 5 downward to a position where the welding stand 3 can grip the upper part of the pipe 5.
Subsequently, the upper part of the pipe 5 is gripped by the gripping part 3c, so that the upper end of the pipe 5 becomes the base end 4 of the pipeline 10 (step 5). At this time, the tip end 8 of the pipeline 10 is bottomed out by a winch or the like (not shown) installed on the opposite shore and moved toward the opposite shore. Note that the distal end portion 8 is closed in advance to prevent foreign matter from entering.

The above process is repeated until all the pipes are joined (step 6), and a pipeline 10 consisting of a predetermined number of rows of joined pipes is laid on the riverbed. As described above, in this embodiment, the base end 4 of the pipeline 10
The work area required to join the new pipe 5 to the new pipe 5 should be large enough to install the pipe support stand 1 that supports the pipe and the crane 6 that lifts the pipe, regardless of the length or diameter of the pipe. It does not require a large area to occupy depending on the length of the pipeline.

[0015] Also, welding for joining pipes is easier because all welding parts are oriented horizontally, so welding only needs to be carried out in a horizontal position, and the welding technique is also reduced. It can be easily learned in a short period of time. In addition, in the above embodiment, the pipe support stand 1 that supports the pipe is
is installed on the land area on one bank 7 side, but it may be installed on the riverside area on the bank 7 side if the river bottom is strong. Further, the pipe support stand 1 shows one means for vertically supporting the base end portion 4 of the pipeline 10 and the new pipe 5, and other known means may be used.

Furthermore, in the above embodiment, a new pipe 5
Although the auxiliary stand 9 was used to prevent the pipe from swinging, other means may be used as long as the lower end of the pipe 5 can be prevented from moving relative to the upper end of the pipe 4 during welding.
Furthermore, the crane 6 may be a tower crane installed at the upper end of the post 2.

[0017]

[Effects of the Invention] As explained above, in the pipeline laying method of the present invention, the area required for joining the base end of the pipeline to a new pipe depends on the length of the pipeline, the pipe diameter, etc. Regardless, it occupies only a small area for installing the device that supports the base end and the new pipe vertically, and furthermore, the welding for the connection only requires welding in a horizontal position. This has the effect of making welding work easier.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the pipeline installation method of this embodiment.

FIG. 2 is a side cross-sectional view showing the connection between the base end of the pipeline and a new pipe.

FIG. 3 is a flowchart showing the flow of the pipeline installation method of this embodiment.

[Explanation of symbols]

1 Pipe support stand 4 Base end of pipeline 5. New pipe 8. Tip of the pipeline 10 Pipeline 11 Welding equipment

Claims (1)

[Claims] Claim 1: In a pipeline laying method in which a new pipe is added to the base end of the pipeline and the distal end of the pipeline is stretched toward a predetermined position, the base end of the pipeline is supported with the base end facing upward. At the same time, a method for laying a pipeline, characterized in that the lower end of a new pipe with its axis facing up and down is joined to the upper end of the base end by welding.