JPH10311067A - Deep water intake path and its construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deep water intake path and its construction method which does not require any structure for protecting steel pipes from wave force and can reduce on-sea and undersea works remarkably. SOLUTION: A deep water intake path to intake deep water from undersea is provided with through holes 12 and 13 formed to interconnect a land 20 with an undersea deep layer part 25 and a pipe body 11 which is inserted into the through holes and installed extensively from a position higher by a specified length than a sea level 22 to the underside of transparent water layer in the ground 26. In order to construct the deep water intake path, the holes 12 and 13 are formed from the land to the undersea deep layer part through the transparent water layer, and the pipe body is inserted into the holes so that the pipe body is inserted extendedly into the hole 12 from the position higher by a specified length than the sea level to the underside of the transparent water layer. Before the holes are passed through to the undersea deep layer part, water is filled into the pipe body to a position higher by a specified length than the sea level, and the holes are passed to a middle deep layer part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deep water intake channel formed so as to penetrate from the land to a deep part of the sea to take in deep water in the sea, and a method of constructing the same.

[0002]

2. Description of the Related Art Seawater (deep water) having a depth of 200 m or less is
Because of its low temperature, clean and high nutritional properties, it is used for medical treatment, fisheries, temperature difference power generation, and the like. In order to pump deep water to facilities on the ground, conventionally, the diameter is 15 to 20.
cm steel pipe is placed on the seabed and the water depth is 200
m and is used as a deep water intake channel.

[0003]

In the above-mentioned conventional deep water intake channel, there is a problem that a large wave force acts on the steel pipe in the wave breaking zone and the steel pipe is apt to be damaged. When a structure is constructed in a wave breaking zone, there is a drawback that construction costs are greatly increased.

When a deep water intake channel is constructed by using steel pipes, a long steel pipe of 500 to 1000 m is used, and a special work boat is required to transport the long steel pipe, and the transportation cost is high. Has the disadvantage of becoming
The installation of long steel pipes on the sea floor also has the problem of low workability due to work at sea and underwater.

The present invention has been made to solve the above problem by focusing on the drawbacks of the prior art described above, and its object is to eliminate the need for a pipe laid along the seabed to a deep part in the sea, and therefore, to provide a wave. An object of the present invention is to provide a deep water intake channel which does not require a structure for protecting a pipe body from a force in a wave breaking zone, and can greatly reduce construction costs.

Another object of the present invention is to provide a deep water intake channel which does not require a special work boat for transporting construction materials at sea and can greatly reduce high-risk offshore and undersea operations. It is to provide a construction method.

[0007]

In order to solve the above-mentioned problems, the present invention provides a deep water intake channel for taking in deep water in the sea, which is formed so as to communicate from the land to a deep sea portion. And a pipe which is inserted into the through hole and extends from a position higher than the sea surface by a predetermined length to a position below the permeable layer of the ground, to provide a deep water intake channel. The pipe extends below the deepest permeable layer in the ground where the deep water intake channel is constructed, in order to prevent the deep water withdrawn through the deep water intake channel from leaking into the permeable layer. . Further, the section from the lower part of the through hole to the deep part in the sea may be formed without providing a lining body such as a pipe. Further, the pipe may be any pipe as long as it can oppose the pressure from the ground and the internal pressure of deep water. For example, a steel pipe, a polyethylene pipe, a vinyl chloride pipe, or the like can be used.

According to the present invention, there is further provided a drilling step of forming a hole from the land through the permeable layer toward a deep part in the sea, and forming a pipe in the hole from a position higher than the sea surface by a predetermined length and below the permeable layer. A pipe insertion step of inserting a pipe into the hole so that the body extends, and before the hole penetrates into the deep sea depth, filling the pipe with water and positioning it at a predetermined height above the sea surface. And a penetrating step of penetrating the hole into a deep sea part after the water filling step.

Here, the pipe insertion step can be appropriately performed during the drilling step or before or after this step. That is, when the ground for drilling is fragile and the inner surface of the hole is easily collapsed, it is preferable that the inner surface of the hole be protected by the pipe by performing the drilling step while inserting the pipe. Conversely, if the ground to be drilled is sufficiently hard, the insertion of the pipe into the hole is performed at an appropriate timing before the water filling step so as not to hinder the drilling operation. be able to.

In the present invention, the hole (through-hole) may extend in any linear shape as long as the hole communicates from the land to a deep sea part having a predetermined depth. Straight line, straight line through the turning point in the middle,
It can be formed in a curved shape or a linear shape in which these are combined. The most preferable line shape is a straight line shape (not limited to the vertical direction) extending from the land until it penetrates the deepest permeable layer, and a curved line, a straight line, or the like from below. It extends to the deep sea part in combination. With such a linear shape, a straight pipe can be used in the pipe insertion step, the cost of the pipe material can be reduced, and good workability can be obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. FIG. 1 is a sectional view schematically showing a deep water intake channel of the present invention, and FIG. 2 is an enlarged sectional view showing an enlarged upper end portion of the deep water intake channel of FIG. 1 and 2, the deep water intake channel of the present invention is formed with vertical holes 12 and 13 formed so as to communicate from the land 20 to the deep sea portion 25, and is inserted into the upper section 12 of the vertical hole. And a pipe 11 extending from a position higher than the sea surface 22 by a predetermined length to a position below the permeable layer 21 of the ground 26.

Here, the vertical holes 12, 13 are approximately 10 cm in diameter.
The vertical hole 12 extends vertically downward, while the vertical hole 13 communicates with the vertical hole 12 and extends in a curved shape. Deep part 2
5 and the through opening is the intake 14 of the deep water intake channel.
Becomes The water intake 14 is disposed on an inclined surface 23 having a water depth of approximately 200 m or less.

The pipe 11 to be inserted into the vertical hole 12 is a straight steel pipe having a diameter of about 8 cm to 45 cm, from which excavated earth and sand and rocks are removed. 13 is communicated. Further, the tube 11
May extend further downward depending on the condition of the ground. That is, when the ground below the permeable layer 21 is fragile and the inner surface of the vertical hole 13 is easily broken, if the pipe 11 is extended downward until the ground reaches a sufficiently hard ground, the pipe 11 The inner surface can be protected from collapsing. In the deep water intake channel of the present invention, if necessary,
A pump (not shown) and a pipe (not shown) are connected to the upper end 11a of the pipe body 11 to supply deep water to a treatment facility, a utilization facility, and the like.

Next, a method for constructing a deep water intake channel according to the present invention will be described. First, a drilling machine is installed on the coastal land part 20, and the drilling machine generally has a diameter of 10 cm to 50 cm.
The vertical holes 12 are drilled in the vertical direction or with the end of the hole facing the shore. Here, in this drilling step, drilling work is performed by passing a boring machine or the like used for drilling of oil or a hot spring through the pipe body 11, and gradually from above into the formed vertical hole 12. The tube 11 is press-fitted. The vertical hole 12 is formed by the above drilling step to penetrate the water-permeable layer 21. When the pipe 11 reaches below the water-permeable layer 21, the press-fitting of the pipe 11 is stopped, and the vertical hole 12 communicates with the vertical hole 12. The drilling operation is continued to form the hole 13 and the boring machine is moved to a depth of 20 mm.
Propulsion toward a predetermined position on the seabed below 0 m. And before the vertical hole 13 penetrates into the deep sea part 25, the pipe 1
1, water 24 or seawater is injected into the vertical holes 12 and 13 and filled up to a position higher than the sea surface 22, and the sea surface 22 and the pipe 1
Maintain a sufficient head difference with the water surface in 1. After the head difference is thus generated, the drilling operation is continued to penetrate the vertical hole 13 into the deep sea part. Here, an internal pressure due to the head difference acts on the inside of the vertical hole 13 before penetration, and at the time of penetration, excavated earth and sand and rocks are blown into the sea at the time of penetration, so that the water intake 14 is reliably formed. .

[0015]

The deep water intake channel of the present invention is formed by a through-hole formed so as to communicate from the land to the deep part of the sea, and a pipe inserted into the through-hole. The construction cost is greatly reduced because there is no need for pipes laid along the seabed to the deep part of the sea, and there is no need to install structures in the breaking zone to protect the pipes from wave forces. can do.

In the method for constructing a deep water intake channel according to the present invention, a hole is formed from the land to penetrate the permeable layer toward the deep part in the sea, and the hole extends from a position higher than the sea surface by a predetermined length to below the permeable layer. Insert the tube into the hole so that the tube extends into the hole, and fill the tube with water before the hole penetrates into the deep sea depth to a position higher than the sea surface by a predetermined length. Fill,
After the water filling step, the hole is made to penetrate into a deep sea part. Therefore, in the present invention, most of the deep water intake channel can be constructed only by land work such as drilling from the land to the deep sea part using a drilling machine such as a boring machine. There is an advantage that high offshore and undersea operations can be greatly reduced, and a high-cost special work boat is not required.

Still further, in the present invention, water is poured into the pipe to fill the pipe to a position higher than the sea surface by a predetermined length, and a head difference is generated between the sea surface and the pipe, and thereafter, the hole is penetrated into the deep sea part. Therefore, at the time of penetration, the water pressure due to the head difference acts outward, and the excavated earth and rock can be blown out into the sea. Therefore, it is possible to prevent the opening to the deep underwater part from being blocked by earth and sand and rocks, and to construct a through-hole, that is, a deep water intake channel that reliably communicates from the deep underwater part to the land.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a deep water intake channel of the present invention.

FIG. 2 is an enlarged sectional view showing an upper end portion of the deep water intake channel in FIG. 1 in an enlarged manner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Pipe 12 Vertical hole 13 Vertical hole 20 On land 21 Permeable layer 22 Sea surface 24 Water 25 Deep sea part 26 Ground

Claims (2)

[Claims] 1. A deep water intake channel for taking in deep sea water, comprising: a through hole formed so as to communicate from the land to a deep sea portion; And a pipe extending from a position higher than a predetermined length to below the permeable layer of the ground. 2. A drilling step of forming a hole from the land through the permeable layer toward the deep part in the sea, and a pipe extending into the hole from a position higher than the sea surface by a predetermined length and below the permeable layer. A pipe insertion step of inserting a pipe into the hole so that the hole is filled with water before the hole penetrates into a deep sea part to fill the pipe to a position higher than the sea surface by a predetermined length. A method for constructing a deep water intake channel, comprising: a filling step; and, after the water filling step, a penetration step of penetrating the hole into a deep sea part.