JPH06248872A - Method of burying pipe in ground and pipe therefor - Google Patents

Abstract

PURPOSE:To propel a pipe by small propulsive force, by a method wherein porous layers, of which the permeable coefficient is made smaller in proportion to a radially outward distance, are formed on the periphery of a pipe body, and the pipe is inserted into the ground while an injection material is being pumped into the layers from the end part of the pipe. CONSTITUTION:The periphery of a pipe body 2 is covered with a corrosion-proof layer 3 made of polyethylene or the like. A first covered layer 5 consisting of porous polymers and having high permeability coefficient, and a second covered layer 6 consisting of cement bentenites and having low permeability coefficient, are formed on the layer 3. In this way, covered layers 4 are porously composed, of which the permeability coefficient is made smaller in proportion to a radially outward distance. After a vertical shaft 8 is excavated, an end part 9 on a pipe 1 is pushed by a jack 10, and the pipe 1 is axially propelled and is inserted into the ground. After that, an injection material-feeding means 11 is connected with the end part 9 on the pipe 1 and an injection material, such as a lubricant, is fed from a feed source 13 having a pump etc., through a flexible pipe 12. In this way, the lubricant seeps into soil 7 through the periphery of the second covered layer 6 of the covered layers 4 and the pipe 1 can be easily inserted into the ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for burying a pipe for transporting a fluid such as gas in the ground and a pipe for underground burying used therein.

[0002]

2. Description of the Related Art Conventionally, in order to bury a pipe such as a gas pipe in the ground by a non-excavation method, a hume pipe is previously buried by propulsion work, and then the main pipe is inserted into the hume pipe. It is installed.

[0003]

In such a prior art, it is necessary to bury the Hume pipe in the ground and then insert the main pipe into the Hume pipe. Therefore, it is troublesome twice and the construction period is long. Become. Further, in order to bury the fume pipe, it is necessary to perform propulsion and excavation of a fume pipe having an outer diameter considerably larger than the outer diameter of the main pipe, which requires a large propulsion power and a great cost. Further, the frictional force between the outer peripheral surface of the fume tube and the soil becomes large, so that the fume tube cannot be propelled and buried over a long distance.

An object of the present invention is to provide a method for burying a pipe in the ground with a relatively easy operation and a pipe for burying in the ground.

[0005]

According to the present invention, there is provided a tube body having a porous layer formed on the outer peripheral surface of the tube body, the porous layer having a smaller permeability coefficient toward the outer side in the radial direction. It is a method of underground embedding of a pipe, in which the pipe is inserted into the ground while pumping the injection material.

Further, the present invention is the underground burying pipe, characterized in that a porous layer having a smaller permeability coefficient is formed on the outer peripheral surface of the pipe main body in the radially outward direction.

[0007]

According to the present invention, a pipe for underground embedding has a coating layer formed on the outer peripheral surface of a pipe body such as a steel pipe, and the coating layer is made of a porous material having a smaller permeability coefficient toward the outer side in the radial direction. The pipe is pushed into the ground and inserted into this layer while the injection material is being pumped from the axial end of the pipe. This injection material is
Lubricating oil, for example, by pumping such lubricating oil from the axial end of the pipe, the lubricating oil is supplied in the axial direction of the pipe through the radial inside where the permeability coefficient of the layer is large. Further, it oozes out substantially uniformly in the circumferential direction through the outer peripheral portion of the layer and is interposed between the outer peripheral surface of the layer and the soil. This reduces the coefficient of friction between the pipe and the soil and allows the pipe to be inserted into the ground by propelling it with a relatively small force. A fluid such as a gas can be transported to this pipe body after being buried in the ground, and therefore, it is not necessary to propel a fume pipe having a large outer diameter into the ground as in the above-mentioned prior art, which allows Also, the driving force will be small. Also, the pipe can be buried in the ground over a long distance.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a pipe 1 for underground burial according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along a line perpendicular to the axis, and FIG. 2 is a sectional view taken along the axial direction thereof. On the outer peripheral surface of a pipe main body 2 such as a steel pipe for transporting a fluid, a layer 3 for preventing corrosion such as polyethylene is coated and formed, and a coating layer 4 according to the present invention is formed on the layer 3.
Is formed. The coating layer 4 is formed on the first inner side in the radial direction.
And the second layer 6 on the outer side in the radial direction.
The first layer 5 has a large permeability coefficient and is porous, and is made of, for example, a porous polymer. As a material for such a first layer 5, there is, for example, solidified air milk. The second layer 6 is made of a porous material having a smaller permeability coefficient than the first layer 5. As a material of such a second layer 6, there is, for example, cement bentonite. In this way, the coating layer 4 is
It is formed into a porous material having a smaller permeability coefficient toward the outer side in the radial direction. In this embodiment, the transmission coefficient is changed stepwise by the first layer 5 and the second layer 6, but as another embodiment of the present invention, the transmission coefficient is changed continuously in the radial direction. It may be a layer configured to.

Referring to FIG. 3, when the underground burying pipe 1 shown in FIGS. 1 and 2 is propelled into the soil 7 to be buried, a vertical hole 8 is formed as shown in FIG. 3 (1). Is excavated, the end portion 9 of the pipe 1 is pushed by the jack 10, and the pipe 1 is propelled in the axial direction and inserted into the ground. At this time, as shown in FIG. 3 (2), the injection material supply means 11 is connected to the end portion 9 of the pipe 1, and the supply source 13 is provided with a pump or the like via the flexible pipe 12.
Pump the injection material from. This injection material is, for example, lubricating oil, and by supplying such lubricating oil to the end portion 9 of the pipe 1, the lubricating oil forms a soil with the soil 7 from the outer peripheral surface of the second layer 6 of the coating layer 4. It bleeds out between the two, whereby the coefficient of friction between the outer peripheral surface of the second layer 6 and the soil is reduced, and the pipe 1 can be inserted into the soil 7 by the propulsive force of the relatively small jack 10.

FIG. 4 is a sectional view of the injection material supplying means 11. The end of the tube 2 is sealed with a lid 14. The end portion of the cylindrical body 15 having a diameter larger than the outer diameter of the flexible tube 1 is bound to the outer peripheral surface of the second layer 6 of the coating layer 4 with the belt 16 and airtightly fixed. The flexible tube 12 is connected to the cylindrical body 15, and from the supply source 13, for example, 1 to 10 kg / c.
The injection material, for example lubricating oil as described above, is pumped at a pressure of m ² . In the initial stage of the supply pressure of the injection material, the supply pressure is set to be relatively low, so that the injection material is rapidly supplied to the first layer 5 having a large permeability coefficient in the axial direction of the pipe, and the second layer 6 is supplied. The injection material is also supplied from the end portion in the pipe axial direction, and the injection material in the first layer 5 is guided to the second layer 6 from the radially inner side to the outer side. After the injection material is uniformly distributed and supplied to the first layer 5 and the second layer 6 in the pipe axis and the pipe circumferential direction, the pressure of the supply source 13 is increased. As a result, the injection material oozes from the second layer 6 to the outside, contacts the soil 7, and is injected. After that, by propelling the tube 1 into the soil 7 using the jack 10 and inserting the tube 1, the tube 1 can be inserted with a relatively small propulsive force of the jack 10.

As shown in FIG. 3 (3), a similar pipe 1 a is further added to the pipe 1 to propel it into the soil 7. To connect the pipes 1, 1a at the connecting portion 17, the pipe bodies 2, 2a of the pipes 1, 1a are exposed and welded at their end faces 18, as shown in FIG. Portions of the pipes 1 and 1a corresponding to the pipe 1 are shown with the same numerals and a subscript a. Next, the tube body 2, 2a or the layer 3, 3a formed thereon
A pair of half-divided connecting members 19 and 20 of which the cross section perpendicular to the axis is shown in FIG. This connection member 1
9 and 20 are made of the same material as the first layer 5 and are porous with a large permeability coefficient. Next, as shown in FIG. 6 (2), which is a sectional view perpendicular to the axis, a pair of half-divided second connecting members 21,
Place 2. The connecting members 21 and 22 are made of the same material as the second layer 6 and are porous with a small permeability coefficient.

After connecting the pipes 1 and 1a in this way, the pipes 1 and 1a are pushed into the soil 7 by the jack 10 and propelled.
As shown in (4), the injection material supply means 11 is attached to the end portion 9a of the pipe 1a, and the injection material is pressure fed from the end portion 9a. The lubricant fed under pressure from the end 9a of the pipe 1a has the same structure as the pipe 1 described above,
Through the cover layer, then through the connecting part 17, and then through the pipe 1
Of the tube 1 and exudes outwardly from the tube 4 of the tube 1, which also applies to the tube 1a. Thus, by using the lubricating oil as the injecting agent, the pipes 1, 1a can be propelled into the soil 7 over a long distance with a small frictional force. For example, as shown in FIG. Not only that, but the pipe 1b can be further connected and propelled. The pipe 1b, which is shown in FIG. 3 (5) and has a short distance to be thrust and inserted into the soil 7, is covered with the coating layer 4
May not have.

The injection material may be a lubricant such as a lubricant as described above, but as another embodiment of the present invention, it may be a ground improvement material such as mortar, cement or bentonite. Alternatively, a drug such as a backfill material may be used. Thus, the present invention can also be implemented to prevent the soil 7 from loosening and prevent the ground surface from sinking.

The outer diameter of the tube body 2 is, for example, 300 to 20.
The layer thickness of the first layer 5 is, for example, 30 to 100 mm, and the layer thickness of the second layer 6 is substantially the same as the layer thickness of the first layer 5.

As another embodiment of the present invention, the half-divided connecting members 21 and 22 shown in FIG. 6 (2) may be made of a material through which the injectable material does not permeate, that is, the permeation coefficient is zero. . Further, the connecting members 19 and 20 shown in FIG.
May be made of a material having a higher transmission coefficient than that of the first layer 5, or may have a structure in which passages are formed in the axial direction.

FIG. 7 is a sectional view of still another embodiment of the present invention. Insert the tube 1 into the hole 23 previously formed in the soil 7,
The cord 24 and the winch 25 may be used for retracting and inserting. At this time, the injecting material supplying means 11 is connected to the end portion 9 of the tube 1 to supply the injecting material. When the injection material is lubricating oil, even if the pulling force of the winch 25 is relatively small, the pipe 1 can be pulled into the soil 7 over a long distance and inserted into the ground to be buried.

The pipe body 2 may be made of a material other than steel pipe, and may be made of synthetic resin such as polyethylene.
In the first layer 5, passages extending in the tube axis direction may be formed at intervals in the circumferential direction.

[0018]

As described above, according to the present invention, the porous coating layer formed on the outer peripheral surface of the pipe body of the underground burying pipe is
The permeation coefficient is formed to become smaller toward the outer side in the radial direction, and the pipe is inserted into the ground while pumping the pouring material from the axial end portion of the pipe to this coating layer. It passes through the radially inner part of the coating layer in the axial direction, and oozes out from the radially outer part to the outer surface of the coating layer, which reduces the coefficient of friction with the soil and, therefore, a relatively small propulsive force. This allows the tube to be propelled and inserted into the ground over long distances. In addition, when there is a space on the outer circumference of the pipe, the injection material is supplied to fill the space in the soil with the injection material from the outer peripheral surface of the layer, which prevents the soil from loosening and the ground surface to sink. You can solve problems such as

[Brief description of drawings]

FIG. 1 is a cross-sectional view perpendicular to the axis of an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the tube 1 shown in FIG. 1 along the tube axis direction.

FIG. 3 is a cross-sectional view showing a process of propelling and inserting tubes 1, 1a and 1b into soil 7.

FIG. 4 is a cross-sectional view of an injection material supplying means 11 and its vicinity.

FIG. 5 is a side view of the vicinity of the connecting portion 17 of the pipes 1 and 1a.

FIG. 6 is a connecting member 1 used in a connecting portion 17.
It is sectional drawing which shows 9,20; 21,22.

FIG. 7 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1, 1a, 1b Pipe 2 Pipe body 3 Anticorrosion layer 4 Covering layer 5 1st layer 6 2nd layer 7 Soil 11 Injection material supply means 12 Flexible tube 13 Supply source 10 Jack 17 Connection part 19, 20; 21, 22 Connection member

Claims (2)

[Claims] 1. A pipe in which a porous layer having a smaller permeability coefficient is formed on the outer peripheral surface of the pipe body toward the outer side in the radial direction, while the injection material is pumped from the axial end of the pipe to the pipe. A method of burying a pipe to insert a pipe into the ground. 2. A pipe for underground embedding, characterized in that a porous layer having a smaller permeability coefficient is formed on the outer peripheral surface of the pipe body toward the outer side in the radial direction.