JP2006070509A - Underground pipeline installation method - Google Patents

Abstract

A technique for preventing a collapse of a wall surface of an excavation hole excavated from the ground toward an offshore and constructing a healthy pipeline is provided.
A drilling hole having one end opened into the water is propelled from the land side, and a resin pipe to be drawn into the drilling hole is allowed to settle in the water on the extension of the drilling hole. Is immediately connected to one end of the resin pipe 31 at the tip of the excavation propulsion pipe, and the excavation propulsion pipe is retracted to draw the resin pipe 31 into the excavation hole 11 to form a lining. Protect.
[Selection] Figure 1

Description

  The present invention relates to a method for installing underground pipes, and more specifically, for example, an underground excavation hole having one end opened into water, for example, 120 to 800 mmφ and a length of 100 m to more than 1000 m is excavated from the land side. The present invention relates to an underground conduit installation method in which a drilling hole wall is lined with a resin pipe after being opened.

  When there are obstacles on the ground and when installing pipes etc. in the ground avoiding this, conventionally, a starting shaft and a reaching shaft are provided, and a pipeline is formed between these two shafts by a propulsion method etc. There is technology. As a technique for installing a pipeline in the ground without excavating such a shaft, there is a technique for excavating a reverse arch-shaped underground hole and laying a casing or a conduit along the hole (for example, a patent) Reference 1).

  This technique is a technique for excavating large-diameter underground holes sequentially using a washover pipe and constructing a casing or a conduit.

  Moreover, the technique of laying a steel pipe from the starting point to the end point across an obstacle such as a river is also known (see, for example, Patent Document 2).

  This technology drills an arc-shaped pilot hole while pushing the pilot bit with a boring rod, attaches a drilling bit to this boring rod, attaches a drill pipe behind the drilling bit, and drills the drilling hole while rotating the drill pipe. Expand the hole, attach the expanded reamer or reed reamer to the starting side as the final step, attach the middle pipe to the rear of the reamer so that it rotates with the reamer, cover the steel pipe to be laid on the middle pipe, and provide the reamer with a swivel joint In this technique, the steel pipe is caused to follow the steel pipe, and the middle pipe is rotated while being pushed into the hole to lay the steel pipe in the arc-shaped hole.

  In addition, when excavating a drill hole along the planned curve entering the ground from the surface, select the drilling tool organization according to the soil or rock quality to be drilled and attach it to the tip of the drill pipe. There is a technique for drilling a drill hole according to a planned curve while adjusting the hole locus according to the orientation, inclination, and position of the hole monitored by a measuring instrument (see, for example, Patent Document 3) .)

  Applications of such planned curves include pipelines, power transmission lines, optical fiber paths, cogeneration, lifelines, drainage channels, measurement holes, injection holes, and the like. As such a planned curve, there are pipelines that open from the surface of the ocean, lakes and other shores through the ground to the offshore, such as oil and other landings, shoreline approaches, various pipelines, transmission lines, optical fibers, etc. Used as

Such a line can be installed without any influence on the breakwater or harbor facilities. In such a drilling hole that opens in water, measures must be taken to prevent the collapse of the pipe wall surface as soon as possible after the drilling hole opens in water.
Japanese Examined Patent Publication No. 61-40840 Japanese Patent Publication No.62-13480 Japanese Patent Laid-Open No. 10-317883

  An object of the present invention is to provide a technique for quickly preventing a collapse of a wall surface of an excavation hole and constructing a healthy pipeline after an excavation hole excavated from the ground toward an offshore is opened in water. Is.

  The present invention has been made to solve the above-mentioned problems. A drilling hole whose one end is open to the water is propelled from the land side, while a resin pipe to be drawn into the drilling hole is submerged in the water. An underground conduit characterized in that after the tip of the excavation propulsion pipe reaches underwater, the resin pipe is connected to the tip of the excavation propulsion pipe, the excavation propulsion pipe is retracted, and the resin pipe is drawn into the excavation hole. It is an installation method.

  In the method of the present invention, as the resin pipe, for example, a polyethylene pipe, a vinyl chloride pipe, a reinforced resin pipe reinforced with carbon fiber, aramid fiber, or the like can be used. These pipes are used by extending a seamless long pipe from the land to the water or from a trolley or the like. In this case, it is preferable to enclose a liquid whose specific gravity is adjusted in the resin tube and slowly settle it in water at an appropriate speed. For the specific gravity adjustment, a solution or slurry using a substance that dissolves in water or a substance mixed with water may be used. As such substances, alkali metal salts or alkaline earth metal salts, fine powders of iron, silicon, other oxides, natural sand, and the like can be used. Furthermore, it is preferable to use salt water (NaCl water) as the liquid with adjusted specific gravity because it may be released into the water after construction in the ocean or rivers close to this.

  According to the present invention, a synthetic resin pipe or the like is lined immediately after excavation into an excavation hole excavated from the land to underwater, and the wall of the excavation hole is prevented from collapsing and effective as various pipes and the like. It became possible to use it. Especially for drilling holes that open in or near the sea, by adjusting the specific gravity of the synthetic resin pipe with salt water, it is possible to easily prepare a pipe with any specific gravity that floats in sea water, and discharges salt water after construction. However, it is extremely useful because it does not have any adverse effect on the environment. In addition, the specific gravity adjustment improves the balance of the tube and makes the movement in the water smooth, so that the pull-in resistance is reduced, and the long tube is easily drawn.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 3 is an explanatory diagram showing an example of a drilling method for excavating a drill hole along a planned curve entering the ground from the ground surface. The drill pipe 1 is caused to enter the underground 20 to be excavated with an inclination along the planned curve from the ground surface 21. For example, a drill bit 2 is attached to the tip of the drill pipe 1, and a mud motor 3, a vent sub 4, a measuring instrument 5, and a nonmagnetic collar 6 are subsequently attached. High pressure water is fed from the drill pipe 1 and sprayed from the tip of the drill bit 2 into the ground. The drilling device (propulsion device) 10 is pushed into the ground while rotating the drill pipe 1, and detects the direction of travel, that is, the orientation, inclination, and position of the hole by the measuring device 5, and injects the high-pressure water along the planned curve. The excavation bit is advanced while adjusting the trajectory of the hole while adjusting the hole trajectory with the vent sub. The mud motor 3 is rotated by high-pressure water to rotate the bit.

  1 to 2 are explanatory views showing an embodiment of the method of the present invention. A drilling hole 11 that opens from the ground surface 21 through the underground 20 to the bottom 26 of the ocean 24 is drilled using the drilling device 10. This excavation hole 11 opens offshore, for example, under the breakwater 25 or the like. This excavation hole 11 is used for a crude oil transportation route from a large ship, a power transmission line, an optical fiber route, and the like.

  Before the excavation hole 11 opens into the water, a synthetic resin pipe 31 to be drawn into the excavation hole 11 as a lining pipe is prepared in the water.

  The synthetic resin pipe 31 is generally arranged in the extending direction of the excavation hole 11 and the length is longer than the length of the excavation hole 11. After adjusting the specific gravity of the synthetic resin pipe 31, the synthetic resin pipe 31 is drawn out from the land into the water, or is sequentially wholesaled from the top of the carriage 30 into the sea. This work should be done when the wind wave is calm. The synthetic resin pipe 31 is attached with a floating tool, a weight or the like as necessary so that it can be properly fed into the sea. A traction tool 32 or the like is attached to the tip of the tube 31.

  The synthetic resin tube 31 encloses in the tube 31 a liquid whose specific gravity is adjusted so as to settle gently in water. The specific gravity adjusting material sealed in the tube 31 can be made using various substances, but in the sea, salt water is most suitable. Since the salt has a specific gravity of 2.164 and a solubility in 100 g of water at room temperature of 35.8 g (20 ° C.), salt water having a specific gravity of about 1.35 can be easily prepared as a solution. If necessary, a liquid having a higher specific gravity can be made including insoluble matter.

  For example, the specific gravity of high-density polyethylene is about 0.94 to 0.96 with respect to the specific gravity of seawater of 1.024, but the specific gravity of the entire pipe is encapsulated with salt water adjusted according to the pipe diameter. It is easy to adjust to about 1.1 to 1.15. If salt water is used, such a specific gravity adjusting liquid will not cause any environmental pollution if it is released into the sea after the work is completed.

  FIG. 1 is an explanatory view showing an underground conduit installation method according to an embodiment of the present invention.

  The arc-shaped excavation hole 11 is excavated from the surface 21 by the excavator 10 toward the offshore, and the ground excavator 10 connecting the resin pipe to the tip of the excavation pipe pulls back the drill pipe as indicated by an arrow 35. The synthetic resin pipe 31 is easily drawn into the excavation hole 11 and protects the wall surface of the excavation hole. The specific gravity adjusting liquid sealed in the synthetic resin tube is released into water.

  FIG. 2 shows a case where a synthetic resin pipe is fed out from the carriage 30. The trolley 30 loaded with the synthetic resin pipe 31 is floated on the ocean or the like 24, and the synthetic resin pipe 31 is gradually drawn out into the water. The diving operator guides the tip of the synthetic resin pipe 31 to the tip of the drilling hole, and couples the synthetic resin pipe 31 to the tip of the drill pipe 1. Thereafter, the synthetic resin pipe 31 is drawn into the excavation hole 11 as shown in FIG.

It is explanatory drawing of an Example. It is explanatory drawing of an Example. It is explanatory drawing of excavation hole excavation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drill pipe 2 Drill bit 3 Mud motor 4 Vent sub 5 Measuring instrument 6 Nonmagnetic collar 10 Drilling device 11 Drilling hole 20 Underground 21 Ground surface 24 Ocean etc. 25 Breakwater 26 Submarine 30 Cargo ship 31 Synthetic resin pipe 32 Traction tool 35 Arrow

Claims (3)

  The excavation hole with one end opened into the water is propelled from the land side, while the resin pipe to be drawn into the excavation hole is allowed to settle in the water, and after the excavation propulsion pipe tip reaches the water, the excavation propulsion pipe tip The resin pipe is connected to the pipe, the excavation propelling pipe is retracted, and the resin pipe is drawn into the excavation hole.   An underground conduit installation method, wherein the resin pipe is filled with a liquid whose specific gravity is adjusted, and is submerged in water.   The underground conduit installation method, characterized in that the liquid whose specific gravity is adjusted is salt water.

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