JP2005282839A - Construction method for pipeline - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce construction cost by sharing construction work of pipelines for power cable and pipelines for gas transportation by making a part of pipelines for power cable which are provided in parallel capable of being used as pipelines for gas transportation with an inner face lining method using shape-memory polyetylene pipes. <P>SOLUTION: An inner face of at least one pipeline 1g of two or more parallel provided power cable pipelines 1, ... is lined with a polyolefine pipe 3. At least one pipeline 1g is set as the pipeline for gas transportation. In this case, lining is made possible as a bent and reduced polyolefine pipe having shape-memory of circle section area is inserted into at least the pipeline 1g and the inserted pipe is enlarged and restored to be its original shape. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for constructing a pipeline, and makes it possible to divert a part of a plurality of juxtaposed power cable pipelines as gas transport pipelines.

  In the underground transmission line, in the case of the tunnel type, it may be combined with the gas transportation, etc., but in the case of the pipeline type, the gas transportation pipeline etc. is constructed separately even if it is the same route. The company has built dedicated facilities for power cables and gas transportation.

Construction of pipelines for power cables and pipelines for gas transportation are common in terms of excavating road surfaces, connecting and laying pipe materials, placing manholes, and filling back excavation grooves, and after power transmission and gas transportation start Is common in that it requires regular maintenance and inspection in the manhole.
Thus, conventionally, even in the case of the same route, the power cable conduit and the gas transport conduit are individually constructed, (1) the construction cost is high, (2) the construction period is long, and the vicinity There are concerns about inconvenience to residents and prolonged traffic obstacles. (3) Expansion of excavation area is inevitable, and environmental degradation will be inevitable due to increase in industrial waste such as asphalt and non-renewable excavated soil. (4) There are inconveniences such as an increase in maintenance and maintenance costs due to separate equipment.
The basic difference between the power cable pipeline and the gas transport pipeline is that the latter requires airtightness, whereas the former does not require watertightness as well as airtightness. In other words, in power cable pipelines, pipe materials such as glass fiber reinforced plastic pipes and asbestos pipes are joined by simple fitting, and rainwater that enters the pipelines due to the non-watertightness of the joints in the manholes. A waterproof part is attached to the pipe opening so as to prevent it from flowing into the pipe through the pipe opening.

  As a method of constructing aging existing pipes such as gas transport pipes and water pipes, plastic pipes are memorized in their original circular cross-sectional shape, bent and reduced, inserted into existing pipes, and steam is blown from the pipe ends after insertion. There is known an inner lining method in which heating is performed at a temperature and then cooling is performed while switching to air and expanding the diameter. (For example, see Patent Document 1)

US Pat. No. 4,986,951

  An object of the present invention is to construct a power cable conduit and a gas transport conduit by allowing a part of a plurality of parallel power cable conduits to be diverted to a gas transport conduit by the inner surface lining method. The common purpose is to reduce the construction cost and to eliminate the inconveniences described above.

  The pipe line construction method according to claim 1 is characterized in that at least one inner surface of a plurality of power cable pipelines arranged in parallel is lined with a polyolefin pipe, and at least one of the pipelines is used as a gas transport pipeline. It is characterized by.

  The pipe construction method according to claim 2 is the construction method of the power cable pipe construction according to claim 1, wherein a bending reduced polyolefin pipe storing a circular cross-sectional shape is inserted into at least one pipe, and the insertion pipe The lining is performed by expanding the diameter of the material to the original shape.

  According to a third aspect of the pipe construction method, at least one pipe inner surface is lined with a polyolefin pipe by a construction method according to the first or second aspect over a plurality of spans including manholes in the middle, and both sides are disposed in the manhole. The lining polyolefin pipes are hermetically connected.

  The pipe line construction method according to claim 4 is a method of lining at least one pipe inner surface with a polyolefin pipe by a construction method according to claim 1 or 2 over a plurality of spans including manholes in the middle, and lining polyolefin pipes on both sides of the manhole. It is characterized by being connected with a gas pipe that bypasses the manhole.

  The construction method of the pipeline of claim 5 is the construction method of the power cable pipeline of claim 3, wherein the gas transport pipe portion and its connection in the manhole are connected to the power cable portion and its connection in the same manhole. It is characterized by detouring.

  A construction method for a pipeline according to claim 6 is characterized in that, in the construction method for a power cable pipeline according to claim 5, the gas transport pipe portion in the manhole and its connecting portion are surrounded by a protective tube.

  According to a seventh aspect of the present invention, there is provided a method for constructing a pipeline, wherein a polyethylene pipe is used as the polyolefin pipe in the method for constructing a power cable pipeline according to any one of the first to sixth aspects.

  The pipe construction method according to claim 8 is the power cable / gas transport composite pipeline constructed by the construction method according to any one of claims 1 to 7 and the gas transport pipe is replaced with the power cable. It is characterized by being returned to the pipeline.

A gas transport pipeline can be constructed simply by lining the inner surface of at least one pipeline of multiple power cable pipelines with polyolefin pipes, excavating road surfaces, connecting and laying pipe materials, placing manholes, Backfilling can be made common to power cable pipelines and gas transport pipelines.
Thus, (1) the cost reduction due to the above-mentioned commonization is superior to the increase in the labor cost due to the lining, and the advantages of this cost reduction can be sufficiently retained, and the construction cost can be reduced. The shortening of the construction period due to the above-mentioned standardization is larger than the above, and the advantages of this shortening of the construction period can be fully maintained, and the construction period can be shortened. The amount of industrial waste such as soil can be reduced and environmental degradation can be reduced. (4) The common use of manholes can reduce the cost of maintenance and inspection work for power cables and gas.
In addition, the lining polyolefin pipe can be reinforced with pipe material against external pressure such as earth pressure, the polyolefin pipe can be made thinner, and the lining polyolefin pipe can be easily inserted to improve the flexibility of the lining polyolefin pipe. it can.

  In particular, according to the second aspect of the present invention, since the diameter of the lining polyolefin pipe in which the circular original shape is memorized is also expanded by the original shape restoring force by heating, the internal pressure for the diameter expansion can be lowered accordingly, and the lining polyolefin pipe can be reduced accordingly. Can be inserted with low traction, and lining can be performed easily.

  In particular, according to the third aspect, the gas transport distance can be set in units of the span of the power cable conduit, and can easily correspond to the distance of the gas supply point.

  In particular, according to the fourth aspect, it is not necessary to provide a space for disposing the gas pipe in the manhole, the maintenance and inspection work of the power cable can be easily performed, and the thermal expansion and contraction of the cable in the pipeline due to the cable offset is also possible. It can be done as usual. In addition, the power cable and the gas line can be safely isolated via the earth and sand even at the manhole location, and it is possible to make sure that the power work standard and the gas work standard are guaranteed.

  In particular, according to the fifth aspect, the gas inspection in the manhole can be easily performed, and the cable offset in the manhole is smoothly changed due to the thermal contraction of the cable in the duct so that the thermal contraction of the cable in the duct is performed. Can be absorbed well.

  In particular, according to claim 6, the external pressure strength equivalent to the lining polyolefin pipe reinforced against the external pressure by the pipe material can be given to the gas transport pipe portion of the manhole, and the external pressure resistance of the entire gas transport pipe is guaranteed. it can.

  In particular, according to the seventh aspect, the lining work can be further facilitated due to the flexibility (high tensile elongation at break) and lightness (small specific gravity) of polyethylene.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 (a) is a longitudinal sectional view showing a composite conduit for power cable and gas transport constructed according to the present invention, and FIG. 1 (b) is an enlarged top view of the portion A in FIG. 1 (a). It is.
In FIG. 1, reference numerals 1,... Indicate a multi-stage / multi-row (three-stage / three-row) side-by-side power cable conduit, and a standard pipe between manholes 10 installed with a predetermined span (usually 300 m). Road materials (glass fiber reinforced plastic pipe, asbestos pipe, etc.) 11 are connected and laid by a simple fitting method, and both ends of the series of connection pipe road materials are sanded and embedded in the concrete wall 101 of the manhole 10. It is. Reference numeral 21 denotes a power cable drawn into the power cable conduit 1c, 22 denotes a cable connecting portion, an offset is formed in the cable portions 23 on both sides of the cable connecting tube, and a waterproof portion 24 is attached to the conduit opening. 1 g is a pipe used as a gas transport pipe, and is made airtight by lining a polyolefin pipe, for example, a polyethylene pipe 3 on the inner surface.
In the polyolefin pipe 3, since external pressure such as earth pressure is supported by the pipe material 11, the size and material can be set only from the transport gas pressure (internal pressure). The maximum use internal pressure MOP is the minimum required strength (50 (Years later) is MRS, overall safety factor is k (3 or more recommended by Gas Association), and tube outer diameter / tube thickness is SDR.

MOP = 2MRS / [k (SDR-1)]
For example, for a transport gas pressure of 0.3 Mpa (natural gas), the safety factor k is 3 and the SDR is 17, and the temperature is 40 ° C. (normally the transport gas temperature is 20 ° C. A high-density polyethylene having an MRS of 7.95 Mpa at 40 ° C. in consideration of heating can be used.

  The construction method of a pipeline according to the present invention uses an existing pipeline of an existing power cable line as a gas pipeline from the middle when a power cable line and a gas pipeline are constructed at the same time on the same route. Applicable to cases.

  One end of the gas transport line must be connected to the gas supply source base, and the middle and other end must be connected to the gas user. Must be excavated in the middle of the span and led out, but to avoid damaging other pipe materials and power cables during the excavation, one of the uppermost pipes, For example, it is desirable to use the upper center pipe for gas transportation.

FIG. 2 shows a cross section of an example of a polyethylene pipe for lining used in the pipe line construction method according to claim 2, which is an omega type in which a circular cross section indicated by a dotted line is stored and bent and reduced, The width W is W ≦ 0.75D, the height H is H ≦ 0.75D, the inner gap d ≧ 5 mm, and a polyethylene pipe having a diameter 150A and a thickness t = 8.5 mm is used for a pipe inner diameter of 100 to 150 mm. Can be used.
In order to manufacture this polyethylene pipe for lining, polyethylene is extruded into a circular pipe, and it is gradually formed into the above-mentioned omega type at a high temperature range while it is cooled, and then rapidly cooled to near room temperature to freeze and store the omega shape. Can be taken.

In order to line the polyethylene pipe on the gas transport pipe by the pipe line construction method according to claim 2, the drum around which the polyethylene pipe for lining shown in FIG. 2 is wound is placed on the manhole as shown in FIG. The pulling wire 31 is connected to the tip of the lining polyethylene pipe 30 and the wire 31 is pulled by the winch 32 to insert the lining polyethylene pipe 30 into the gas transporting line 1g. Since the width W and the height H of the cross section of the polyethylene pipe 30 for lining are W ≦ 0.75D and H ≦ 0.75D and are sufficiently smaller than the pipe inner diameter D, this insertion is easy.
After this insertion, as shown in FIG. 3 (b), one end of the insertion pipe is connected to the boiler 34 by a high-pressure / high-temperature hose pipe 33, and the insertion pipe is heated by steam to expand its diameter toward the original circular shape. It is brought into close contact with the inner surface of the pipe, and after that, the boiler is switched to an air compressor and cooled by feeding air.

  FIG. 4 is a view showing a main part of the method for constructing a pipeline according to claim 3, wherein at least one of the pipelines on both sides of the manhole 10, for example, the inner surface of the upper middle pipeline In the same manner, polyethylene pipes are lined, and then the lined polyethylene pipes are hermetically connected by a connecting pipe 300 in the manhole 10.

  FIG. 5 shows the main part of the composite cable pipeline for power cable and gas transport constructed by the pipeline construction method of claim 4, and the polyethylene pipe is placed in the uppermost central pipeline on both sides of the manhole. After lining the pipe, the end of the pipe opening of each lining polyethylene pipe is closed by fusing the plug body 3001 or by crushing and fusing the pipe end, and both lining pipes are bypassed by a gas pipe 3000 that bypasses the manhole 10, for example, polyethylene pipe. The ends are connected airtight.

6. The pipe construction method according to claim 5, wherein the lined polyethylene pipes are hermetically connected directly or via a polyethylene gas pipe, and the gas pipe portion in the manhole is surrounded by a protective pipe. It is said.
Although linear thermal expansion coefficient of the polyethylene pipes to be used as lining pipe is considerably large compared to the linear thermal expansion coefficient of the power cable (power linear thermal expansion of the cable coefficient 2 × 10 -5 ^{/ K} to 14 to 15 × 10 ^{- 5} / K), if the bending rigidity of the protective pipe (for example, SUS) is made considerably larger than the bending rigidity of the polyethylene pipe, the thermal expansion and contraction of the lining polyethylene pipe toward the manhole is suppressed by the protective pipe. Can be expected to be absorbed in the pipeline.
In addition, the protective tube has an airtight structure, which can prevent gas leaks into the manhole and can safely perform maintenance and inspection work in the manhole.

FIGS. 6A and 6B show an example of connection and protective construction of polyethylene pipes in the manhole.
Prior to this construction, as shown in FIG. 7, a protective short pipe 301 is inserted into the pipe opening 1g ′ of the pipe 1g for gas transport, and the inner end of the inserted protective short pipe 301 is connected to a pipe material (glass fiber (Reinforced plastic pipe, asbestos pipe) It is fixed to the inner surface with an adhesive 301 '.
For example, SUS can be used for the protective short tube 301. As the adhesive, for example, a laminate of a glass cloth and a glass nonwoven fabric impregnated with an epoxy resin can be used, and the resin can be cured by heating after being attached to the joint surface in an uncured state of the epoxy resin.
In the construction example shown in FIG. 6, a polyethylene pipe for lining is drawn into a pipe line designated for gas transportation, and the polyethylene pipe for lining is drawn out into a manhole for a predetermined length as shown in FIG. The protective tube main body 302 is inserted into the polyethylene pipe end 3e, and the protective tube main body 302 is connected to the protective short tube 301 in an airtight manner (usually flange connection). The protective tube main body has a telescope slide portion 302 ′ in the middle. This protective tube main body 302 can also be made of SUS, like the protective short tube 301.
After inserting the protective tube main body 302 into the polyethylene pipe drawing end 3e in the manhole in this way, the expansion of the lining polyethylene pipe described above is performed, and then both polyethylene pipes with the expanded diameter are restored. The ends are hermetically connected by the joint 41. The joint 41 can be made by heat-sealing by using a polyethylene electro-fusion joint with an inner surface embedded with a heating wire.
After the polyethylene pipe lead-out ends are connected in an airtight manner in this way, the telescope slide 302 ′ of the protective tube main body 302 is extended as shown in FIG. The telescope slide portions 302 'and 302' are hermetically sealed by wrapping a seal tape or the like, and the airtightness and protective tube by the adhesive between the protective short pipe and the pipe line material are sealed. The airtightness of the protective tube is secured in cooperation with the airtightness of the connection portion between the main body and the protective short tube, and the construction is completed with this.

(A) and (b) of FIG. 8 show another example of connection and protection construction of polyethylene pipes in the manhole.
In this construction example, a polyethylene pipe for lining is drawn into a pipe line designated for gas transportation, and a polyethylene pipe for lining is drawn into a manhole 10 for a predetermined length as shown in FIG. A protective tube main body (for example, made of SUS) 303 is inserted into the end 3e, and the protective tube main body 303 is connected to the protective short tube 301. A protective tube main body (for example, made of SUS) 304 with a telescope slide is inserted through the polyethylene straight tube 42.
After the protective pipe main body 303 is inserted into the polyethylene pipe lead-out end 3e in the manhole 10, the diameter expansion of the polyethylene pipe for lining described above is performed, and thereafter, as shown in FIG. Both polyethylene pipe drawing end pipes 30e, 30e whose diameters have been restored are connected airtightly by a polyethylene straight pipe 42 through joints 43, 43.
As the joint 43, a polyethylene electric fusion joint having an inner surface embedded with a heating wire is used, and the connection can be performed by heat fusion.
After this connection, the telescope slide 304 ′ of the protective tube main body 304 is extended, and then both ends of the protective tube main body 304 and the protective tube main bodies 303 and 303 are connected in an airtight manner, thereby completing the construction.

(A) and (b) of FIG. 9 show an example different from the above-described connection and protection construction of the polyethylene pipe in the manhole.
In this construction example, the pipeline defined for gas transportation is lined by expanding the diameter of the polyethylene pipe for lining described above, and then, as shown in FIG. A polyethylene vent pipe 44 is hermetically connected to the pipe port by a joint 45, and a polyethylene vent pipe 441 in the reverse direction is hermetically connected to the vent pipe 44 by a joint 46, and the polyethylene straight pipe 42 is connected between the reverse direction vent pipes 441 and 441. The airtight connection is made through the joints 47 and 47.
For the joints 45, 46, and 47, a polyethylene electric fusion joint having an inner surface embedded with a heating wire is used, and the connection can be performed by heat fusion.
After this connection, as shown in FIG. 9B, the polyethylene vent pipe, the polyethylene straight pipe, and the joint are hermetically surrounded by the divided protective pipe main body 305, and both ends of the protective pipe main body 305 and the protective short pipes 301, 301 are enclosed. Are connected in an airtight manner, and the construction is completed.
The split protective tube main body 305 can be made of SUS. As shown in FIG. 9C, the adapter 306 is welded to both sides of one of the broken pieces 305a, and the other broken piece 305b is put through the putty tape 307. The two pieces 305a and 305b are fastened with the stainless steel band 308 to fasten and seal the upper and lower cracks, and the longitudinal crack is fastened and sealed with a flange connection via a packing. .

(A) and (b) of FIG. 10 show another example of connection and protection construction of polyethylene pipes in the manhole.
In this construction example, the pipeline defined for gas transportation is lined by expanding the diameter of the polyethylene pipe for lining described above, and then, as shown in FIG. A polyethylene straight pipe 440 is connected to the pipe port in an airtight manner by an elbow joint 450, and the polyethylene straight pipes 440 and 440 are connected in an airtight manner by the polyethylene straight pipe 42 through elbows 460 and 460 in opposite directions.
For the elbows 450 and 460, a polyethylene electric fusion elbow in which a heating wire is embedded in the inner surface is used, and the connection can be performed by heat fusion.
After this connection, as shown in FIG. 10B, the polyethylene straight tubes 42, 440, 440 and the elbows 450, 450, 460, 460 are hermetically surrounded by the divided protective tube main body 315, and the protective tube main body 315 Both ends are connected to the protective short tubes 301 and 301 in an airtight manner, and the construction is completed.
The structure of the split protective tube main body 315 used in this construction example is the same as that of the split protective tube main body 305 used in the construction example of FIG. be able to.

  The pipeline construction method according to the present invention is intended to provide a power and gas supply facility at low cost and promptly to support a large gas business and to improve the asset value of the pipeline by effectively utilizing the existing power facility. If there is no need for gas, the lining polyethylene pipe, the double pipe in the manhole, etc. can be removed and returned to the pipeline dedicated for power transmission.

1 (a) is a drawing showing a composite conduit for power cable and gas transportation constructed according to the present invention, and FIG. 1 (b) is an enlarged explanatory view of a portion A in FIG. 1 (b). It is drawing which shows the cross-sectional dimension of the shape memory polyolefin pipe used in Claim 2. It is drawing which shows the lining construction of the polyolefin pipe of the pipeline inner surface for gas transport used in Claim 2. It is drawing which shows the principal part of the composite pipe line for electric power cables and gas transport constructed | assembled by Claim 3. It is drawing which shows the principal part of the composite pipe line for electric power cables and gas transport constructed | assembled by Claim 4. It is drawing which shows one Example of Claim 5. It is drawing which shows the attachment structure to the pipe opening of the pipe for gas transportation of the protection short pipe in the Example of FIG. It is drawing which shows the Example different from the above of Claim 5. It is drawing which shows the Example different from the above of Claim 5. It is drawing which shows the Example different from the above of Claim 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, ... Multiple parallel line 1c Pipe for power cable 1g Pipe for gas transport 10 Manhole 11 Pipe material 21 Power cable 22 Cable connection pipe 23 Cable offset 3 Lining polyethylene pipe 30 Shape memory polyethylene pipe 30e Polyethylene in manhole Pipe outlet end 300 Gas connection pipe in manhole 3000 Manhole bypass gas pipe 301 Protection pipe 302 Protection pipe 303 Protection pipe 304 Protection pipe 305 Protection pipe 315 Protection pipe

Claims (8)

A method for constructing a pipeline characterized in that at least one pipeline inner surface of a plurality of power cable pipelines arranged in parallel is lined with a polyolefin pipe, and that at least one pipeline is a gas transport pipeline. 2. The pipe according to claim 1, wherein a lining is performed by inserting a bend-reducing polyolefin pipe having a memorized circular cross-sectional shape into at least one pipe and expanding the diameter of the inserted pipe to the original shape. Road construction method. The inner surface of at least one pipe line is lined with a polyolefin pipe by a construction method according to claim 1 or 2 across a plurality of spans including manholes in the middle, and the lining polyolefin pipes on both sides in the manhole are hermetically connected. A method for constructing pipelines. The inner surface of at least one pipe line is lined with a polyolefin pipe by a construction method according to claim 1 or a plurality of spans including a manhole in the middle, and the gas pipe bypassing the manhole is connected between the lining polyolefin pipes on both sides of the manhole. A method for constructing a pipeline characterized by: 4. The method for constructing a pipeline according to claim 3, wherein the gas transport pipe portion in the manhole and the connecting portion thereof are detoured with respect to the power cable portion and the connecting portion in the same manhole. 6. The pipe line construction method according to claim 5, wherein the gas transport pipe portion in the manhole and the connecting portion thereof are surrounded by a protective pipe. 7. The pipe construction method according to claim 1, wherein a polyethylene pipe is used as the polyolefin pipe. The lining polyolefin pipe of the composite line for power cable and gas transport constructed by the construction method according to any one of claims 1 to 7 is removed, and the gas transport conduit is returned to the power cable conduit. Pipeline construction method.

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