JPH08214433A - Method of laying underground cable for freezing countermeasure and underground cable facility - Google Patents

Abstract

PURPOSE: To prevent the damage of a cable owing to expansion by the freezing of water intruding into a conduit line by fixing one end of a PE pipe to a pull-up conduit line, fastening one end of a flexible pipe to a duct stop cock in a lower projecting conduit line and overlapping the PE pipe and the flexible pipe in the lower projecting conduit line. CONSTITUTION: One end of a PE pipe 40 is fixed onto a pull-up conduit line 10, and the PE pipe is laid in a conduit line 20 together with a cable C. One end 51 of a flexible pipe 50 is fitted to the side face of the conduit line 20 of a duct stop cock 30, the PE pipe 40 and the flexible pipe 50 are overlapped in the longitudinal direction of the conduit line 20, and the duct stop cock 30 is installed into the duct port of the conduit line 20. Accordingly, even when water intruding into the conduit line 20 in the vicinity of the duct stop cock 30 is frozen and expanded, a volume increasing section owing to the expansion by the freezing is absorbed by the PE pipe 40, and the cable C in the vicinity of the duct stop cock 30 is not damaged by oppression.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a downwardly convex pipe line between a pulling pipe line and a manhole provided along a pulling column, and a cable is provided in the downward convex pipe line. The present invention relates to an underground cable facility and a method of laying an underground cable for freezing measures.

[0002]

2. Description of the Related Art In underground cable facilities laid between manholes, when water flows into a manhole, the water that flows in flows into the pipe, and in cold regions the water that flows into the pipe freezes. When expanded, the volume of the cable expands, which may press the installed cable and damage it.

FIG. 8 is a view showing a cross section of a conventional underground cable facility.

It is an elastic body and has knots at predetermined intervals like bamboo.
PE pipe 80 having a cylindrical structure in which air is sealed
Is installed in the pipeline 70 in parallel with the cable C, thereby preventing the underground cable C from being damaged when the muddy water W in the pipeline 70 freezes. That is, the PE pipe 80 contracts during freezing to absorb the volume expansion of the water in the muddy water W during freezing, and therefore the cable C also remains during the freezing of the muddy water W.
Is not pressed, damage to the cable C due to the pressing can be prevented.

FIG. 9 is an explanatory view of a conventional underground cable facility.

In this conventional example, a pulling pipe line 10 is provided along a pulling column P, and a pipe line 70 descending to the left in the drawing is provided between the pulling pipe line 10 and a manhole M1. A cable C is provided between the hoisting pipeline 10 and the manhole M1 via the inside of the passage 70. A PE pipe 80 is provided in parallel with the cable C.

FIG. 10 is a view showing the vicinity of the duct opening D of the manhole M1 in the above conventional example.

In the above conventional example, the PE tube 80
Is composed of a hollow portion 80T in which air or the like is sealed and a seal portion 80S having a solid structure. And
PE pipe 80 shrinks due to the temperature drop (PE pipe 80 shrinks, for example, 64 cm per 100 m)
In order to prevent the pipe 80 from not being installed, the following is done. That is, the duct mouth D to the manhole M1
If the length L1 from the duct opening D to the first seal portion 80S exceeds 50 cm in the portion where the PE tube 80 projects inward, the first seal portion 80
If the length L1 from the duct opening D to the first seal portion 80S is 50 cm or less at S, the PE pipe 80 is cut at the second seal portion 80S. Then, the PE pipe 80 is arranged along the cable C, and the PE pipe 80 is fixed to the cable C by winding a vinyl adhesive tape around the PE pipe 80 and the cable C about every 50 cm for 2-3 times.

By the way, in the above-mentioned conventional example, in FIG.
At the right end portion of 0, it is connected to the pulling pipe line 10 that is vertically pulled up along the electric pole P, and from there, it is installed at a downward slope toward the manhole M1. In this way, it is necessary to install all of the pipes on the down slope in this way.
This is to prevent water from accumulating inside. Since the muddy water W does not stay in the pipe line 70 by making the entire slope down from the right end portion of the pipe line 70 to the manhole M1 side in this way, it is not necessary to provide a duct stop cock in the manhole M1. , So that the length of the temperature shrinkage of the PE pipe 80 appears in the manhole M1.
0 can be set.

[0010]

However, as described above, if the pipe 70 is installed at a downward slope from the end of the pipe 70 toward the manhole M1, the position of the pipe 70 on the side of the manhole M1 becomes deeper. In addition, there is a drawback that the construction cost of underground equipment becomes expensive due to the deeper pipeline position. In order to overcome this drawback, so-called U-Line
The construction method is adopted.

FIG. 11 is an explanatory view of a conventional U-Line construction method.

The U-Line construction method is an installation method of underground equipment used in a pulling up portion of a cable for pulling out the underground cable C to the ground, and it is considered that all the pipelines connecting the pulling pipeline and the manhole are installed in a downward slope. Instead, it is a construction method in which the pipe line, that is, the downward convex pipe line 71 is installed in a slack shape. Therefore, according to the U-Line construction method, the pipeline position on the manhole M side becomes shallower than before (in FIG. 11, the conventional manhole position is shown by a chain double-dashed line), so the construction cost of the underground facility is low. It has the advantage that it is used in areas other than cold regions.

In the above U-Line method,
When muddy water flows into the pipeline 20, mud is accumulated in the pipeline 20, and the volume of mud makes it impossible to remove the cable C. In order to enable the removal of the cable C, the pipeline 20 is removed. It is necessary to provide the duct water stopcock 30 at the duct opening of the inner wall of the manhole M that communicates. Further, the conventional duct water stopcock 30 has a hole through which the cable C is inserted, and has a structure in which the duct mouth is sealed while the cable C is inserted into the duct water stopcock 30.

Thus, the current duct water stopcock 30 is
The structure is such that the duct mouth is sealed while only the cable C is inserted, and the PE pipe 80 cannot be inserted into the duct water stopcock 30. For this reason, the duct waterstop 30 is installed at a place where it is installed. Cannot apply the above-mentioned anti-freezing measures.

Therefore, when the duct water stop plug 30 is provided at the end of the downward convex pipe 71 on the manhole M side and the PE pipe 80 is provided in the pipe 71, the temperature in the pipe 71 is lowered. At this time, the PE pipe 80 contracts, and the distance between the end 81 of the PE pipe 80 and the duct water stopcock 30 widens.
When the water that has entered the inside of 1 is frozen and expanded, the duct stop cock 30
There is a problem that the cable C in the vicinity is damaged by pressure.

Further, in this case, the duct water stopcock 30 is disengaged from the end of the pipeway 71 on the manhole M side by the freeze expansion pressure due to the water that has entered the pipeway 71 in the vicinity of the duct waterstop 30. Also occurs.

Of course, by modifying the duct water stopcock 30,
It is conceivable to form a hole for taking out the pipe 80 and prevent the water from entering without fixing the PE pipe 80. However, depending on the outer diameter of the cable C, the PE pipe 80 to be inserted into the pipeline is formed. Considering that the number of each is different and that it is necessary to prevent water from entering without fixing the PE pipe 80 to the duct stopcock, developing a new duct stopcock is a burden of development costs. Is big and not a good idea.

A first object of the present invention is to provide a duct water stopper at the end of the downward convex pipe line on the manhole side, and to provide P in the pipe line.
When a pressure-shrinkable rod-shaped body such as an E pipe is provided, when the temperature in the conduit decreases, the pressure-shrinkable rod-shaped body contracts, and the end of the pressure-shrinkable rod-shaped body and the duct water stop plug The distance increases,
At this time, even if the water that has entered the pipeline near the duct water stopcock freezes and expands, the cable near the duct waterstop is not damaged by pressure.

A second object of the present invention is to provide a duct water stopper at the end of the downward convex pipe line on the manhole side, and to provide P inside the pipe line.
When a pressure-shrinkable rod-shaped body such as an E pipe is provided, when the temperature in the conduit decreases, the pressure-shrinkable rod-shaped body shrinks to form an end portion of the pressure-shrinkable rod-shaped body and a duct water stopper. Even if the water that has entered the pipeline near the duct stopcock freezes and expands at this time, the freezestopping pressure causes the duct stopcock to come off from the end of the pipeline on the manhole side. Is to be surely prevented.

A third object of the present invention is to provide a duct water stop plug at the manhole side end of the downward convex pipe line and to provide a pressure shrinkable rod-shaped body such as a PE pipe in the pipe line. After that, when it becomes necessary to remove the pressure-shrinkable rod-shaped body, the removal work should be easy.

[0021]

SUMMARY OF THE INVENTION According to the present invention, a downward convex pipe line is provided between a pulling pipe line provided along a pulling column and a manhole, and a cable is provided in the downward convex pipe line. In the underground cable facility in which the duct water stop is provided at the manhole side end of the downward convex pipeline, one end of the PE pipe is fixed to the pulling pipeline, and the cable is installed in the downward convex pipeline. The PE pipe is provided in parallel, the flexible pipe is provided in parallel with the cable in the downward convex pipe line, one end of the flexible pipe is fixed to the duct water stop, and there is room for expansion and contraction of the PE pipe. The flexible pipe has a length corresponding to the length, and the PE pipe and the flexible pipe overlap each other in the downward convex conduit.

[0022]

According to the present invention, one end of the PE pipe is fixed to the pulling pipe, and the P pipe is placed in the downward convex pipe in parallel with the cable.
An E pipe is provided, a flexible pipe is provided in parallel with the cable in the downward convex conduit, and one end of the flexible pipe is fixed to the duct water stopcock. Since the flexible pipe is provided and the PE pipe and the flexible pipe overlap each other in the downward convex pipe line, when the temperature in the downward convex pipe line decreases, the PE pipe Shrinks, the distance between the end of the PE pipe and the duct water stopcock increases, and at this time, even if the water that has entered the pipe line near the duct waterstop freezes and expands, the flexible pipe contracts. As a result, the cable near the duct water stopcock is not damaged by pressure.

[0023]

FIG. 1 is an explanatory view showing an underground cable facility 1 which is an embodiment of the present invention.

The underground cable facility 1 is provided with a downwardly convex pipe line 20 below the ground G between the pulling pipe line 10 provided along the pulling column P and the manhole M. A cable C is provided in the conduit 20, and a duct water stop plug 30 for preventing water from flowing into the downwardly convex conduit 20 is provided at an end of the downwardly convex conduit 20 on the manhole M side. It is a thing.

A PE pipe 40 is provided in parallel with the cable C in the downward convex conduit 20.
Reference numeral 0 denotes a rod-shaped body that repeatedly contracts when pressurized and expands when depressurized, and has a hollow portion and a seal portion like the PE pipe 80, and one end of which is fixed to the conduit 10. A flexible pipe 50 is provided in parallel with the cable C in the downward convex conduit 20, and one end 51 of the flexible pipe 50 is fixed to the duct water stopcock 30. The flexible pipe 50 is a rod-shaped body that repeatedly contracts when pressure is applied and expands when pressure is reduced, and the same flexible pipe 50 as the PE pipe 40 can be used. Further, the flexible pipe 50 has a length corresponding to the extra length of expansion and contraction of the PE pipe 40.
0 overlaps in the downward convex conduit 20.

Next, the operation of the above embodiment will be described.

In order to install the underground cable equipment 1, first, one end of the PE pipe 40 is pulled up and fixed to the pipe line 10, the PE pipe is laid in the pipe line 20 together with the cable C, and the pipe of the duct stop cock 30 is installed. One end 51 of the flexible pipe 50 is attached to the side surface of the passage 20, and the PE pipe 40 and the flexible pipe 50 are overlapped with each other in the longitudinal direction of the pipe passage 20, so that the duct water stopper 30 is formed. Install in the duct mouth of 20.

FIG. 2 is a view showing a state where the duct water stopcock 30 is installed at the duct opening of the manhole M in the above embodiment.

The duct water stop plug 30 is inserted into the pipe line 20 to prevent the muddy water from flowing into the pipe line 20. When the duct water stop plug 30 is attached to the duct mouth. The end 41 of the PE pipe 40 is attached to the duct water stopper 30.
The seal portion of the PE pipe 40 is cut so that it does not hit. Then, before the duct water stopcock 30 is attached to the duct mouth, a flexible pipe 50 having a length L corresponding to the extra length of expansion and contraction of the PE pipe 40 is provided on the duct 20 side of the duct water stopcock 30. Attach end 51. The PE pipe 40
The length L corresponding to the extra length of expansion and contraction is the distance between the end 41 of the PE pipe 40 and the surface of the duct water stop 30 on the side of the conduit 20 that occurs when the ambient temperature of the PE pipe 40 decreases. . Further, the length of the flexible pipe 50 is set so that the PE pipe 40 and the flexible pipe 50 overlap with each other in the longitudinal direction of the conduit 20 even when frozen.

As described above, when the PE pipe 40 is provided in the downward convex pipe line 20 and the duct water stop plug 30 is provided at the end of the pipe line 20 on the manhole M side, the temperature in the pipe line 20 is lowered. At this time, the PE pipe 40 contracts, and the distance 21 between the end 41 of the PE pipe 40 and the duct water stopcock 30 widens, and at this time, the duct 2 near the duct waterstop 30.
Even if the water that has entered 0 is freeze-expanded, the volume increase due to this freeze-expansion is absorbed by the PE pipe 40, and the cable C in the vicinity of the duct stopcock 30 is not pressed. The cable C near the stopper 30 is not damaged by pressure.

That is, if the PE pipe 40 contracts, for example, 64 cm in a 100 m span due to the temperature characteristics, PE
There is a section where the pipe 40 is not inserted by 64 cm per 100 m, but since the flexible pipe 50 is inserted in parallel with the PE pipe 40, the PE pipe 40 or the flexible pipe 50 is always inserted in the entire section. Therefore, the influence of the freezing pressure on the cable C can be prevented. Although the flexible pipe 50 shrinks due to temperature, the length of the flexible pipe 50 may be set in consideration of this temperature shrinkage.

Further, in the above embodiment, even if the water that has entered the pipe line 20 freezes and expands in the vicinity of the duct water stopcock 30,
Since the volume increase due to this freezing expansion is absorbed by the flexible pipe 50, the pressure on the duct water stopcock 30 does not increase,
Therefore, the duct water stopcock 30 will not come off from the duct opening of the manhole M.

In the above embodiment, the PE pipe 4 is used.
0, PE used in the current anti-freezing construction method
A pipe can be used, and as the duct stop cock 30, a duct stop cock currently used in a place other than a cold region can be used.

The PE pipe 40 is an example of a first pressure-shrinkable rod-shaped body which is provided in the downward convex pipe line in parallel with the cable and has one end fixed to the pull-up pipe line. The sex pipe 50 is an example of a second pressure-shrinkable rod-shaped body that is provided in the downward convex pipe line in parallel with the cable and has one end fixed to the duct water stopcock.

FIG. 3 shows the cable C in the above embodiment.
It is a figure which shows the relationship between the outer diameter and the required number of PE pipes.

In FIG. 3, the flexible pipe 50
As an example, the same PE pipe 40 is used as the PE pipe 40, and the “PE pipe required to prevent the duct stop cock 30 from coming off during freezing” corresponds to the flexible pipe 50. Yes, the “PE pipe 40 required to protect the cable C during freezing” is the PE pipe 40 that has almost the same length as the cable C in the pipelines 10 and 20 and is installed in parallel with the cable C. Is. Note that FIG.
The PE pipe shown in 1 is 19 mmφ, 1 seal section length is 2.
It is 0m.

In FIG. 3, when a cable C having an outer diameter of 25 mm is used, for example, there are two "PE pipes necessary for preventing the disconnection of the duct stopcock 30 during freezing", and "the cable C during freezing". PE needed to protect
The number of pipes 40 "is three, and a total of five PE pipes are required. When using the cable C having an outer diameter of 50 mm, a total of three PE pipes are required. Cable C
The larger the outer diameter of the pipe 20, the smaller the cross-sectional area of water in the cross-sectional area of the pipe 20, so the freeze expansion pressure gradually decreases at the same temperature. Therefore, as the outer diameter of the cable C increases, the PE pipe The number required is small.

The material of the PE pipe 40 is low density polyethylene, and the coefficient of linear thermal expansion is 10 to 22 × 10 ^-5.
/ K. In addition, the laying length of the PE pipe 40 is 100
m, and the temperature difference is -20. C-20. C, or 40. If C changes, PE due to temperature changes
Expansion and contraction length of the pipe 40 is 0.40 to 0.88 m / 10
It is 0m.

FIG. 4 is an explanatory view of an underground cable facility 2 which is another embodiment of the present invention. FIG. 5 is a diagram showing a state where the duct water stopcock 30 is installed at the duct opening of the manhole M in the underground cable facility 2.

The underground cable facility 2 is basically the same as the underground cable facility 1 except that the end portion 52 of the flexible pipe 50 and the end portion 41 of the PE pipe 40 are connected by a connecting cord R. Is different from the underground cable facility 1. The connection string R is a string that connects the PE pipe 40 and the flexible pipe 50 in order to prevent the PE pipe 40 from being unable to be removed when the cable is removed due to the temperature shrinkage of the PE pipe 40.

In the underground cable facility 2, a duct stop 30 is provided at the duct opening of the manhole M, and the duct 20
In the case where the PE pipe 40 is provided inside, when the duct pipe water stopper 30 is removed when the PE pipe 40 needs to be removed thereafter, the flexible pipe fixed to the duct water stopper 30. 50 is drawn out, and the PE pipe 40 connected by the connecting string R is also drawn out. Therefore, even if the PE pipe 40 is buried in the sediment of mud in the mud water in the pipe line 20, Easy to remove.

FIG. 6 is an explanatory view of an underground cable facility 3 which is another embodiment of the present invention. FIG. 7 is a diagram showing a state where the duct water stopcock 30 is installed at the duct opening of the manhole M in the underground cable facility 3.

The underground cable facility 3 is basically the same as the underground cable facility 1, and is different from the underground cable facility 1 only in that a flexible plate member 60 is provided instead of the flexible pipe 50. different. The flexible plate-shaped body 60 is a plate-shaped body that repeats an operation of contracting when pressure is applied and expanding when pressure is reduced.

That is, in the underground cable facility 3, a downwardly convex pipe line 20 is provided between the pulling pipe line 10 provided along the pulling column P and the manhole M, and inside the downward convex pipe line. 20 is provided with a cable C to prevent water from flowing into the downward convex conduit 20.
In the underground cable facility in which 0 is provided at the manhole M side end of the downward convex conduit 20, one end of the PE pipe 40 is fixed to the pulling conduit 10 and parallel to the cable C in the downward convex conduit 20. Then, the PE pipe 40 is provided, and the flexible plate-like body 6 is provided on the side of the downward convex conduit 20 side of the duct water stopcock 30.
0 is fixed. The flexible plate-like body 6
0 is a plate-shaped body that contracts when pressurized and expands when depressurized, and the flexible plate-shaped body 60 is an example of a pressure-contracted body that is fixed to the downward convex conduit side of the duct water stopcock. is there.

In the underground cable facility 3, the pipeline 20
Even if the water that has entered the inside freezes and expands in the vicinity of the duct water stopcock 30, the increase in volume due to this freeze expansion is caused by the flexible plate member 60.
Therefore, the pressure in the vicinity of the duct water stopper 30 does not increase, and therefore the duct water stopper 30 does not come off from the duct opening of the manhole M.

In the underground cable facility 3, PE
The end portion 41 of the pipe 40 and the flexible plate-like body 60 may be connected by a connecting string or the like. By doing so, when the PE pipe 40 needs to be removed, the duct stop is stopped. When the faucet 30 is removed, this duct water stopcock 30
P connected to a flexible plate 60 fixed to
The E pipe 40 is also pulled out, so even if the PE pipe 40 is buried in the pipe line 20 with mud, the PE pipe 40
Is easy to remove.

In each of the above embodiments, the PE pipe 40 may be replaced by another pressure-contracting rod-shaped body which contracts when pressurized and expands when decompressed.

In addition to the above-mentioned embodiment, as a place where a duct stop cock for preventing water from flowing into the pipe line needs to be installed and a measure against freezing is required, There are bridge overhanging pipelines, underpasses, etc., and the above embodiments can be applied to these.

[0049]

According to each of the first, second, fifth and sixth aspects of the present invention, a duct water stop plug is provided at the manhole side end of the downward convex pipe, and a PE pipe or the like is added in the pipe. When the pressure-shrinkable rod-shaped body is provided, when the temperature in the conduit decreases, the pressure-shrinkable rod-shaped body shrinks, and the distance between the end of the pressure-shrinkable rod-shaped body and the duct water stopcock increases. At this time, even if the water that has entered the pipeline near the duct water stopcock freezes and expands, the cable near the duct waterstop is not damaged by the pressure.

According to each of the first to sixth aspects of the invention, a duct water stop plug is provided at the manhole side end of the downward convex pipe, and a pressure shrinkable rod-shaped body such as a PE pipe is provided in the pipe. In this case, when the temperature in the conduit decreases, the pressure-shrinkable rod-shaped body shrinks, which widens the gap between the end of the pressure-shrinkable rod-shaped body and the duct water stopcock. Even if water that has entered the pipeline near the faucet is freeze-expanded, it is possible to reliably prevent the duct water shut-off plug from being detached from the end of the duct on the manhole side due to the freeze expansion pressure.

According to each of the inventions described in claims 2, 4, and 6,
When a duct water stopper is provided at the manhole side end of the downward convex pipe and a pressure shrinkable rod-shaped body such as a PE pipe is provided in the pipe, it is necessary to remove the pressure shrinkable rod-shaped body thereafter. When it occurs, there is an effect that the removal work is easy.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an underground cable facility 1 which is an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which a duct water stopcock 30 is installed at a duct opening of a manhole M in the above embodiment.

FIG. 3 shows the outer diameter of the cable C and PE in the above embodiment.
It is a figure which shows the relationship with the required number of pipes.

FIG. 4 is an underground cable facility 2 which is another embodiment of the present invention.
FIG.

[Fig. 5] In the underground cable facility 2, the duct stop cock 3
It is a figure showing the state where 0 was installed in the duct mouth of manhole M.

FIG. 6 is an underground cable facility 3 which is another embodiment of the present invention.
FIG.

[Fig. 7] In underground cable facility 3, duct stop cock 3
It is a figure showing the state where 0 was installed in the duct mouth of manhole M.

FIG. 8 is a view showing a cross section of a conventional underground cable facility.

FIG. 9 is an explanatory diagram of an underground cable facility in a conventional example.

FIG. 10 is a diagram showing the vicinity of a duct opening D of a manhole M1 in the above conventional example.

FIG. 11 is an explanatory diagram of a conventional U-Line construction method.

[Explanation of symbols]

 1, 2, 3 ... Underground cable facility, C ... Cable, M ... Manhole, P ... Lifting column, R ... Connection string, 10 ... Lifting pipe line, 20 ... Downward convex pipe line, 30 ... Duct stopcock, 40 ... PE pipe, 41 ... End part, 50 ... Flexible pipe, 51, 52 ... End part, 60 ... Flexible plate-like body.

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Kenichi Tsuchida 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (6)

[Claims] 1. A downwardly convex pipe line is provided between a pulling pipe line and a manhole provided along a pulling column, and a cable is provided in the downward convex pipe line. In an underground cable facility in which a duct stopcock for preventing water from flowing into the pipeline is provided at the manhole-side end of the downward convex pipeline, in the downward convex pipeline parallel to the cable. A first pressurizing and contracting rod-shaped body, one end of which is fixed to the pulling-up pipe line; and one end of which is provided in the downward convex pipe line in parallel with the cable, And a second pressure-shrinkable rod-shaped body fixed to the second pressure-shrinkable rod-shaped body, and the second pressure-shrinkable rod-shaped body has a length corresponding to a surplus length of expansion and contraction of the first pressure-shrinkable rod-shaped body. Then, the first pressure-shrinkable rod-shaped body and the second pressure-shrinkable rod-shaped body have the downward convex shape. Underground cable plant, characterized in that overlap within the road. 2. The underground cable facility according to claim 1, wherein the other end of the first pressure-shrinkable rod-shaped body is connected to the other end of the second pressure-shrinkable rod-shaped body. . 3. A downwardly convex pipe line is provided between the pulling pipe line and the manhole provided along the pulling column, and a cable is provided in the downward convex pipe line. In an underground cable facility in which a duct stopcock for preventing water from flowing into the pipeline is provided at the manhole-side end of the downward convex pipeline, in the downward convex pipeline parallel to the cable. And a pressure shrinkable rod-shaped body, one end of which is fixed to the pull-up pipeline, and a pressure shrinkable body fixed to the downward convex pipeline side of the duct water stopcock. Characteristic underground cable equipment. 4. The underground cable facility according to claim 3, wherein the other end of the pressure-shrinkable rod-shaped body and the pressure-shrinkable body are connected to each other. 5. One end of a first PE pipe having a predetermined length necessary for measures against freezing of a cable laid in the pipeline is fixed to a pipeline that is provided along a pipeline. Laying the first PE pipe together with the cable in the conduit; the conduit of a duct stop plug inserted into the conduit to prevent mud from flowing into the conduit Attaching one end of a second PE pipe having a surplus length of expansion and contraction of the first PE pipe to a side surface; the first PE pipe and the second PE
Laying the duct water stopcock at the duct mouth of the pipeline so that the pipe and the pipe overlap in the longitudinal direction of the pipeline; Method. 6. The method for laying an underground cable for anti-freezing according to claim 5, further comprising a connecting step of connecting the other end of the first PE pipe to the other end of the second PE pipe. .