CA1321479C - Method of pipe replacement (no.1) - Google Patents
Method of pipe replacement (no.1)Info
- Publication number
- CA1321479C CA1321479C CA000580574A CA580574A CA1321479C CA 1321479 C CA1321479 C CA 1321479C CA 000580574 A CA000580574 A CA 000580574A CA 580574 A CA580574 A CA 580574A CA 1321479 C CA1321479 C CA 1321479C
- Authority
- CA
- Canada
- Prior art keywords
- pipe
- mole
- temporary
- new
- old
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims abstract description 25
- 230000009172 bursting Effects 0.000 claims abstract description 7
- 239000010687 lubricating oil Substances 0.000 description 3
- 229910001141 Ductile iron Inorganic materials 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000011083 cement mortar Substances 0.000 description 1
- 238000009750 centrifugal casting Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
- F16L55/16—Devices for covering leaks in pipes or hoses, e.g. hose-menders
- F16L55/162—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe
- F16L55/165—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe a pipe or flexible liner being inserted in the damaged section
- F16L55/1658—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe a pipe or flexible liner being inserted in the damaged section the old pipe being ruptured prior to insertion of a new pipe
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/20—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes
- E21B7/205—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes without earth removal
- E21B7/206—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes without earth removal using down-hole drives
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/28—Enlarging drilled holes, e.g. by counterboring
- E21B7/30—Enlarging drilled holes, e.g. by counterboring without earth removal
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method of replacing an old buried pipe with a new pipe comprises attaching a temporary pipe having an external diameter which is substantially the same as the new pipe to the rear end of a bursting mole having a cylindrical body whose external diameter is larger than the old pipe, impulsively moving the mole forward so that a head of the mole intrudes into the old pipe and bursts it to provide an enlarged space for receiving the temporary pipe following the mole, applying the new pipe to one end of the temporary pipe, and withdrawing the temporary pipe such that it is progressively replaced by the new pipe.
A method of replacing an old buried pipe with a new pipe comprises attaching a temporary pipe having an external diameter which is substantially the same as the new pipe to the rear end of a bursting mole having a cylindrical body whose external diameter is larger than the old pipe, impulsively moving the mole forward so that a head of the mole intrudes into the old pipe and bursts it to provide an enlarged space for receiving the temporary pipe following the mole, applying the new pipe to one end of the temporary pipe, and withdrawing the temporary pipe such that it is progressively replaced by the new pipe.
Description
132~7~ ~
"Method of pipe replacement"
THIS INVENTIO~ relates to a method of replacing an existing old pipe, such as water service pipe~ gas pipe or the like, with a new pipe and, in particular, to a method oE replacing an old pipe with a new one without digging up the ground.
When an old pipe, in particular a cast :iron pipe, has deteriorated with age and become unable satisfactorily to perform its func-tion or when it is required to replace -the old pipe with a new due -to new re~uirements, it is desirable to replace the old pipe by a new one without digging up -the ~round, because great labour and cost is involved in ; excavating the old pipe and because such digging woxk ,, .
unavoidably obstructs traffic or affec-ts means of transport and communication.
,' ~.
~: :
According to a known method of pipe replacement called "plpe-in-pipe", a new pipe is simply inserted into the old one under the ground, but this inevitably means that the internal diàmeter of the new pipe mu~t be smaller than that of the old pipe, resulting in a reduction in the capacity for transporting gas or water. ~
~ ~ .
~' ,~
- -, , , , , . .
:. ~ " ;' ' ~
.
-~3~79 An attemp-t has already been made to ovexcome the above-discussed drawhack of the "pipe-in-pipe" method, as disclosed in UK Patents ~B 2152624B "Pipe Replacement System", GB 21243~5B and GB 20~270:LB "Mains Insertion".
The aforesaid prior art discloses a method and an apparatus for pipe replacement in wh:ich a new pipe is attached -to a rear end of a bursting mole having a cylindrical body with an external diameter which is larger than an old pipe to be replaced. The bursting mole and -the new pipe move forward together, and a front end or head of the bursting mole in-trudes into the old pipe and.
progressively burst the old pipe to form an enlarged space to receive the new pipe following behind -the burstiny mole, so that the old pipe is replaced with the new one.
The known method descrihed above may be said to constitute a rational way of replacing buried pipes.
. .
However, when the abo~e known ~ethod is studied in de-tail, several drawbacks are found therein. Tha-t is, the following drawbacks exist whether a new pipe or a sheath is towed into position by the mole:
'~ .
1. When no sheath is used ~i.e., a new pipe is connected to the rear end of the mole for direct renewall:
:. ~
(a) Because an air hose and possibly other items are inserted thxough the new pipe, any paintwork or lining on .~
~32~79 the internal surface of the new pipe may be damaged by the coupling of the hose a-t the time of working or drawing the hose.
~b) Because exhaust air is discharged insicle the new pipe, lubricating oil in the air ~mixing of lubricating oil with the air is necessary for sliding motion of piston) may adhere to the internal surface of the new pipe and soil it. If an exhau~t air hose is provided in an a-ttempt to obviate this problem, not only is the working efficiency lowered but the performance of the air cylinder is also affected due to the reduced discharge cross-section, Moreover, an increased number of hoses is then required, and the danger of damage to the internal surface of the new pipe may increase correspondingly.
~; 15 2. When a sheath is used (i.e., a new pipe is inserted into a sheath aFter the sheath is installed in place of the old pipe):
,:
.".
Because the sheath attached -to the mole should have an internal diameter which is larger than the external diameter of the new pipe, the external diarneter of the mole is obliged ; to be rather large as compared with the former case where no sheath lS used. Accordingly, greater pressure has to be applied to the surrounding ground and working efficiency is thereby lowered. Further, the conse~uences of such greater pressure on the surrounding ground tpressure, Yibration~
~' :
, .
132~4~9 cannot be ignored~ In particular, where there is another existing buried pipe line in the vicinity, then is a serious possibility of disloca-ting the other pipe line or loosening a pipe joint -thereof due to such pressure.
The present invention aims to solve -the above-discussed problems and to provide an improved pipe replacement method by which the internal surface of the new pipe is protected from damage, stain or pollution, while minimizing the adverse consequences on the corresponding ground.
Accordingly, the invention provides a method of replacing an old buried pipe with a new pipe, comprising attachiny a temporary pipe having an external diame-ter which is substantially the same as the new pipe to the rear ` end of a bursting mole having a cylindrical body whose external diameter is larger than -the old pipe moving , . .
n the mole forward so that a head of the mole intrudes . .
into the old pipe and bursts it to provide an enlarged space for receiving the temporary pipe following -the mole, c ~^~r ~` applying the new pipe to ~ end of the temporary pipe, and withdrawing the temporary pipe such that it is procJressively replaced by the new pipe.
, .
A method embodying the invention obviates such problems as damage to the paintwork and lining of the internal surface of the new pipe wikh which the old pipe is replaced. Even when khe drive unit is equipped with an air cylinder, the : . ~ :;. : . .. :. : : .
~32~L47~
internal surface of -the new pipe is prevented from stain and damage due to the adherence of foreign materials ~lubricating oil in the exhaust air), and cleaning of the new pipe after the replacement is no-t required.
S Moreover, since a -temporary pipe having an external diameter almost the same as -the new pipe is used in the ; replacemen-t, the external diameter of the temporary pipe can be one size smaller than a comparable sheath for the same - size of new pipe, so that the driving force necessary for the foxward movement can be correspondingly smaller. As a result, detrimen-tal influences on -the surrounding ground can be reduced.
, Furthermore, the temporary pipe once used can be repeatedly used for future replacements, and therefore the .
; 15 method according to the invention may be said to be more ^ economical as compared with a sheath which is used only once and left buried.
.
, In order that the inven-tion may be more readily understood, embodiments thereof and the prior art, will now be described by way of example with reference to -the a~companying drawings, in which:
Figures l and 2 are diagrammatic sectional views illustrating a method of pipe replacement embodying the ; present invention;
.
,. . .
- ~ . .: :: . -:
1~21479 Figure 3 is a diagrammatic sectional view illustrating an example of a temporary pipe employed in -the method o Figures 1 and 2;
Figure 4 is a sectional view illustrating the wall construction and coupling arrangement o an example of a new pipe;
Figures 5 and 6 are diagrammatic sectional views illustrating respective further embodiments of the ; invention; and .
., ~
., :
Figures 7 to 9 are diagrammatic sectional views 10 . illustrating a prior art pipe replacemen-t method.
' :
Apparatus in accordance with -the prior art is illustrated in detail in Figure 7 of the accompanying drawings, Figures 8 and 9 illustrating a manner of actual ~:; 15 use of this prior apparatus.
. :
As shown in Figure 7, a rear end of a mole 4a having a body with a laryer external diameter than that of an old pipe la is connected to either a new pipe 9a for directly replacing the old pipe or to a sheath 14 for receiving and - 20 protecting -the new pipe.
.. . . . .
, ... ~
7 !~
In Figures 8 and 9, -the mole 4a incorporates an air cylinder serving as a drive unit for the mole, and an air hose 7a for actuating the air cylinder is connected to a pressure source ~compressor 8a) and passes through the new pipe or shea-th. A cable 3a attached to the tip end of the mole passes through the old pipe and is connected -to a win~h 2a.
. ~:
` The mole 4a is impulsively driven forward by the ~: lO driving force applied by the pressure source while being .: subjected to a tractive for~e by the winch -thereby bursting the old pipe. Since the maximum ex-ternal diameter of the mole body is larger -than the external diameter of the old pipe, the fragments o~ the old pipe are pushed outwardly to form a space larger than the external diameter of the new pipe or the sheath which Eollows the mole. In this manner, by utilising the gap corresponding to the difference in the external diameters of the mole and the new pipe, the pipe replacement can be smoothly carried out using a new pipe of substantially the same diameter as the old pipe. The disadvantages of this apparatus are outlined above.
: An embodiment of -the invention will now be described with reference to ~igure 1 (showing the replacement of an old ; 25 pipe with a temporary pipe) and Figure 2 (showing the replacement of the temporary pipe with a new pipe).
...
~ . . . :
,.-.. ., , . , .
:~32~ ~79 The steps involved in the illustratecl pipe replacement method are as follows:
1. A starting pi-t Kl and a destination pi-t K2 are dug at respective ends section of an old buried pipe whi.ch is to be replaced and existing pipe members in the pi.ts are removed.
,,~
r~ 2. A winch :is installed a-t the destination pi-t, ancl a cable 3 of the winch is passed from the destination pit K2 to -the s-tarting pit Kl throwgh -the inside of the old pipe 1.
3. A temporary pipe 5 composed of interconnect.ecl temporary pipe members and having almost the same length as the section of the old pipe to be replaced is attached to -the : rear end of a mole 4, and the mole and the temporary pipe are . coupled together by means of a wire 6 inserted through the temporary pipe 5. The wire is tensioned between the rear end of the mole and -the rear end of the temporary pipe. At this time, an air hose 7 is inserted through the inside of the temporary pipe, and the ends of the air hose are connected to the mole 4 and a compressor 8 respectively.
4. The cable 3 of the winch is connected to the front end of the mole to guide the mole to -the end of -the existing pipe in the starting pit.
. : .: .
:. ~ " ~ ~ ~
~32~79 5. The existing buried pipe is burst by a head of the mole as a result of forward motion o~ the mole 4 under the action of the tractive force of -the winch ancl the impulsive drive of the air cylinder clisposecl in the mole, whereby -the temporary pipe towed by the mole is progressively installed within the fragmented old pipe as the mole progxesses from ; the starting pit to the destina-tion pit.
~, , 6. Upon reaching the destination pit, the mole 4 is uncoupled from the temporary pipe 5 ancl the air supply hose and others inside the temporary pipe are also removed. The foregoing steps 1 to 6 corresponcl to Figure 1.
7. A new pipe member 9 is connected to the end of the temporary pipe in the starting pit and is pushed in toward the destination pit by means of a jacking device 10 disposed in the starting pit/ whereby the temporary pipe S is thrust out of the ground at the destination pi-t by a corresponding amount as the new pipe is inserted.
8. New pipe memhers are inserted one by one from the star-ting pit and pushed toward the destination pit, whereby the temporary pipe is progressively replaced with the new pipe extending from the starting pit -to the destination pit.
When short temporary pipe members are used, as illustra-ted, they are removed one by one at the destination pit. The foregoing steps 7 to 8 correspond to Figure 2.
' - '- . : ~ ': :, ' ~
The above steps remain almost unchanged when a device other than an air cylinder is usecl as a drive uni-t incorporated in the mole, because a drive source is required to be connected -to any such device by way of a hose or cable.
Figure 3 illustrates the construction of a -temporary pipe 5 which may be used in the above described method. As can be seen, the temporary pipe 5 is composed oE
interconnected members each having a reduced diameter spigot portion at one end and an enlarged diameter socket por-tion at the other end for receiving -the spigot portion of an adjacent pipe member. Because the temporary pipe moves under -the ground, it is preferable for the external surface oE the ; pipe to be smooth, although the configuration and material of the temporary pipe does not matter so far as it is durable enough against traction applied by the mole, compressive force applied by the jacking device as the new pipe is inserted, and pressure from the s~rrounding ground.
Figure ~ is a view illustrating an example of a nu-t and bolt joint between adjacent pipe members of the new pipe 9.
The body of the pipes composed of a ductile cast iron processes by centrifugal casting, the internal surface of the pipe is lined with a cement mortar 11, and the external surface of the pipe is coated with an armoured concrete 13 which includes reinforcing bas~et members 12 (composed of welded steel bars) r both internal and external surfaces :. :
13214~79 composing of a ductile cast iron pipe for use in propulsion working for the replacement, which is the most preferable embodiment o~ the inven-tion.
~, In another embodimen-t of the method according to the inven-tion illustrated in E'igure 5, -the new pipe ~ is connected to the rear end of -the te~lporary pipe 5 so as to be pulled through the ground to the destination pit K2 behind the temporary pipe 5 at the latter is pulled ou-t of -the ground by the winch 2, thereby obviating -the head for a jacking device in the starting pit K1. In this embocliment, since the temporary pipe and the new pipe move forward through the space left by the passage of the mole 4, an advantage is that no large propulsion ~i.e.. jacking device) is needed in addition to the propulsion system for the temporary pipe.
Figure 6 illustrates a further embodiment of the pipe replacement method, in which the temporary pipe members are successively connected together within the starting pit K1 where there is insufficient space for the connection to take place at ground level.
"Method of pipe replacement"
THIS INVENTIO~ relates to a method of replacing an existing old pipe, such as water service pipe~ gas pipe or the like, with a new pipe and, in particular, to a method oE replacing an old pipe with a new one without digging up the ground.
When an old pipe, in particular a cast :iron pipe, has deteriorated with age and become unable satisfactorily to perform its func-tion or when it is required to replace -the old pipe with a new due -to new re~uirements, it is desirable to replace the old pipe by a new one without digging up -the ~round, because great labour and cost is involved in ; excavating the old pipe and because such digging woxk ,, .
unavoidably obstructs traffic or affec-ts means of transport and communication.
,' ~.
~: :
According to a known method of pipe replacement called "plpe-in-pipe", a new pipe is simply inserted into the old one under the ground, but this inevitably means that the internal diàmeter of the new pipe mu~t be smaller than that of the old pipe, resulting in a reduction in the capacity for transporting gas or water. ~
~ ~ .
~' ,~
- -, , , , , . .
:. ~ " ;' ' ~
.
-~3~79 An attemp-t has already been made to ovexcome the above-discussed drawhack of the "pipe-in-pipe" method, as disclosed in UK Patents ~B 2152624B "Pipe Replacement System", GB 21243~5B and GB 20~270:LB "Mains Insertion".
The aforesaid prior art discloses a method and an apparatus for pipe replacement in wh:ich a new pipe is attached -to a rear end of a bursting mole having a cylindrical body with an external diameter which is larger than an old pipe to be replaced. The bursting mole and -the new pipe move forward together, and a front end or head of the bursting mole in-trudes into the old pipe and.
progressively burst the old pipe to form an enlarged space to receive the new pipe following behind -the burstiny mole, so that the old pipe is replaced with the new one.
The known method descrihed above may be said to constitute a rational way of replacing buried pipes.
. .
However, when the abo~e known ~ethod is studied in de-tail, several drawbacks are found therein. Tha-t is, the following drawbacks exist whether a new pipe or a sheath is towed into position by the mole:
'~ .
1. When no sheath is used ~i.e., a new pipe is connected to the rear end of the mole for direct renewall:
:. ~
(a) Because an air hose and possibly other items are inserted thxough the new pipe, any paintwork or lining on .~
~32~79 the internal surface of the new pipe may be damaged by the coupling of the hose a-t the time of working or drawing the hose.
~b) Because exhaust air is discharged insicle the new pipe, lubricating oil in the air ~mixing of lubricating oil with the air is necessary for sliding motion of piston) may adhere to the internal surface of the new pipe and soil it. If an exhau~t air hose is provided in an a-ttempt to obviate this problem, not only is the working efficiency lowered but the performance of the air cylinder is also affected due to the reduced discharge cross-section, Moreover, an increased number of hoses is then required, and the danger of damage to the internal surface of the new pipe may increase correspondingly.
~; 15 2. When a sheath is used (i.e., a new pipe is inserted into a sheath aFter the sheath is installed in place of the old pipe):
,:
.".
Because the sheath attached -to the mole should have an internal diameter which is larger than the external diameter of the new pipe, the external diarneter of the mole is obliged ; to be rather large as compared with the former case where no sheath lS used. Accordingly, greater pressure has to be applied to the surrounding ground and working efficiency is thereby lowered. Further, the conse~uences of such greater pressure on the surrounding ground tpressure, Yibration~
~' :
, .
132~4~9 cannot be ignored~ In particular, where there is another existing buried pipe line in the vicinity, then is a serious possibility of disloca-ting the other pipe line or loosening a pipe joint -thereof due to such pressure.
The present invention aims to solve -the above-discussed problems and to provide an improved pipe replacement method by which the internal surface of the new pipe is protected from damage, stain or pollution, while minimizing the adverse consequences on the corresponding ground.
Accordingly, the invention provides a method of replacing an old buried pipe with a new pipe, comprising attachiny a temporary pipe having an external diame-ter which is substantially the same as the new pipe to the rear ` end of a bursting mole having a cylindrical body whose external diameter is larger than -the old pipe moving , . .
n the mole forward so that a head of the mole intrudes . .
into the old pipe and bursts it to provide an enlarged space for receiving the temporary pipe following -the mole, c ~^~r ~` applying the new pipe to ~ end of the temporary pipe, and withdrawing the temporary pipe such that it is procJressively replaced by the new pipe.
, .
A method embodying the invention obviates such problems as damage to the paintwork and lining of the internal surface of the new pipe wikh which the old pipe is replaced. Even when khe drive unit is equipped with an air cylinder, the : . ~ :;. : . .. :. : : .
~32~L47~
internal surface of -the new pipe is prevented from stain and damage due to the adherence of foreign materials ~lubricating oil in the exhaust air), and cleaning of the new pipe after the replacement is no-t required.
S Moreover, since a -temporary pipe having an external diameter almost the same as -the new pipe is used in the ; replacemen-t, the external diameter of the temporary pipe can be one size smaller than a comparable sheath for the same - size of new pipe, so that the driving force necessary for the foxward movement can be correspondingly smaller. As a result, detrimen-tal influences on -the surrounding ground can be reduced.
, Furthermore, the temporary pipe once used can be repeatedly used for future replacements, and therefore the .
; 15 method according to the invention may be said to be more ^ economical as compared with a sheath which is used only once and left buried.
.
, In order that the inven-tion may be more readily understood, embodiments thereof and the prior art, will now be described by way of example with reference to -the a~companying drawings, in which:
Figures l and 2 are diagrammatic sectional views illustrating a method of pipe replacement embodying the ; present invention;
.
,. . .
- ~ . .: :: . -:
1~21479 Figure 3 is a diagrammatic sectional view illustrating an example of a temporary pipe employed in -the method o Figures 1 and 2;
Figure 4 is a sectional view illustrating the wall construction and coupling arrangement o an example of a new pipe;
Figures 5 and 6 are diagrammatic sectional views illustrating respective further embodiments of the ; invention; and .
., ~
., :
Figures 7 to 9 are diagrammatic sectional views 10 . illustrating a prior art pipe replacemen-t method.
' :
Apparatus in accordance with -the prior art is illustrated in detail in Figure 7 of the accompanying drawings, Figures 8 and 9 illustrating a manner of actual ~:; 15 use of this prior apparatus.
. :
As shown in Figure 7, a rear end of a mole 4a having a body with a laryer external diameter than that of an old pipe la is connected to either a new pipe 9a for directly replacing the old pipe or to a sheath 14 for receiving and - 20 protecting -the new pipe.
.. . . . .
, ... ~
7 !~
In Figures 8 and 9, -the mole 4a incorporates an air cylinder serving as a drive unit for the mole, and an air hose 7a for actuating the air cylinder is connected to a pressure source ~compressor 8a) and passes through the new pipe or shea-th. A cable 3a attached to the tip end of the mole passes through the old pipe and is connected -to a win~h 2a.
. ~:
` The mole 4a is impulsively driven forward by the ~: lO driving force applied by the pressure source while being .: subjected to a tractive for~e by the winch -thereby bursting the old pipe. Since the maximum ex-ternal diameter of the mole body is larger -than the external diameter of the old pipe, the fragments o~ the old pipe are pushed outwardly to form a space larger than the external diameter of the new pipe or the sheath which Eollows the mole. In this manner, by utilising the gap corresponding to the difference in the external diameters of the mole and the new pipe, the pipe replacement can be smoothly carried out using a new pipe of substantially the same diameter as the old pipe. The disadvantages of this apparatus are outlined above.
: An embodiment of -the invention will now be described with reference to ~igure 1 (showing the replacement of an old ; 25 pipe with a temporary pipe) and Figure 2 (showing the replacement of the temporary pipe with a new pipe).
...
~ . . . :
,.-.. ., , . , .
:~32~ ~79 The steps involved in the illustratecl pipe replacement method are as follows:
1. A starting pi-t Kl and a destination pi-t K2 are dug at respective ends section of an old buried pipe whi.ch is to be replaced and existing pipe members in the pi.ts are removed.
,,~
r~ 2. A winch :is installed a-t the destination pi-t, ancl a cable 3 of the winch is passed from the destination pit K2 to -the s-tarting pit Kl throwgh -the inside of the old pipe 1.
3. A temporary pipe 5 composed of interconnect.ecl temporary pipe members and having almost the same length as the section of the old pipe to be replaced is attached to -the : rear end of a mole 4, and the mole and the temporary pipe are . coupled together by means of a wire 6 inserted through the temporary pipe 5. The wire is tensioned between the rear end of the mole and -the rear end of the temporary pipe. At this time, an air hose 7 is inserted through the inside of the temporary pipe, and the ends of the air hose are connected to the mole 4 and a compressor 8 respectively.
4. The cable 3 of the winch is connected to the front end of the mole to guide the mole to -the end of -the existing pipe in the starting pit.
. : .: .
:. ~ " ~ ~ ~
~32~79 5. The existing buried pipe is burst by a head of the mole as a result of forward motion o~ the mole 4 under the action of the tractive force of -the winch ancl the impulsive drive of the air cylinder clisposecl in the mole, whereby -the temporary pipe towed by the mole is progressively installed within the fragmented old pipe as the mole progxesses from ; the starting pit to the destina-tion pit.
~, , 6. Upon reaching the destination pit, the mole 4 is uncoupled from the temporary pipe 5 ancl the air supply hose and others inside the temporary pipe are also removed. The foregoing steps 1 to 6 corresponcl to Figure 1.
7. A new pipe member 9 is connected to the end of the temporary pipe in the starting pit and is pushed in toward the destination pit by means of a jacking device 10 disposed in the starting pit/ whereby the temporary pipe S is thrust out of the ground at the destination pi-t by a corresponding amount as the new pipe is inserted.
8. New pipe memhers are inserted one by one from the star-ting pit and pushed toward the destination pit, whereby the temporary pipe is progressively replaced with the new pipe extending from the starting pit -to the destination pit.
When short temporary pipe members are used, as illustra-ted, they are removed one by one at the destination pit. The foregoing steps 7 to 8 correspond to Figure 2.
' - '- . : ~ ': :, ' ~
The above steps remain almost unchanged when a device other than an air cylinder is usecl as a drive uni-t incorporated in the mole, because a drive source is required to be connected -to any such device by way of a hose or cable.
Figure 3 illustrates the construction of a -temporary pipe 5 which may be used in the above described method. As can be seen, the temporary pipe 5 is composed oE
interconnected members each having a reduced diameter spigot portion at one end and an enlarged diameter socket por-tion at the other end for receiving -the spigot portion of an adjacent pipe member. Because the temporary pipe moves under -the ground, it is preferable for the external surface oE the ; pipe to be smooth, although the configuration and material of the temporary pipe does not matter so far as it is durable enough against traction applied by the mole, compressive force applied by the jacking device as the new pipe is inserted, and pressure from the s~rrounding ground.
Figure ~ is a view illustrating an example of a nu-t and bolt joint between adjacent pipe members of the new pipe 9.
The body of the pipes composed of a ductile cast iron processes by centrifugal casting, the internal surface of the pipe is lined with a cement mortar 11, and the external surface of the pipe is coated with an armoured concrete 13 which includes reinforcing bas~et members 12 (composed of welded steel bars) r both internal and external surfaces :. :
13214~79 composing of a ductile cast iron pipe for use in propulsion working for the replacement, which is the most preferable embodiment o~ the inven-tion.
~, In another embodimen-t of the method according to the inven-tion illustrated in E'igure 5, -the new pipe ~ is connected to the rear end of -the te~lporary pipe 5 so as to be pulled through the ground to the destination pit K2 behind the temporary pipe 5 at the latter is pulled ou-t of -the ground by the winch 2, thereby obviating -the head for a jacking device in the starting pit K1. In this embocliment, since the temporary pipe and the new pipe move forward through the space left by the passage of the mole 4, an advantage is that no large propulsion ~i.e.. jacking device) is needed in addition to the propulsion system for the temporary pipe.
Figure 6 illustrates a further embodiment of the pipe replacement method, in which the temporary pipe members are successively connected together within the starting pit K1 where there is insufficient space for the connection to take place at ground level.
Claims (4)
1. A method of replacing an old buried pipe with a new pipe, comprising attaching a temporary pipe having an external diameter which is substantially the same as the new pipe to the rear end of a bursting mole having a cylindrical body whose external diameter is larger than the old pipe, moving the mole forward so that a head of the mole intrudes into the old pipe and bursts it to provide an enlarged space for receiving the temporary pipe following the mole, applying the new pipe to the rear end of the temporary pipe, and withdrawing the temporary pipe such that it is progressively replaced by the new pipe.
2. A method according to claim 1, wherein the mole is moved forwardly impulsively.
3. A method according to claim 1 or 2, wherein the new pipe is thrust into the ground behind the temporary pipe by a jacking device installed in a pit dug to expose one end of the old pipe.
4. A method according to claim 1 or 2, wherein the temporary pipe is pulled from the ground by a winch, thereby towing the new pipe into place.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62160479A JPS646590A (en) | 1987-06-26 | 1987-06-26 | Method of replacing existing main pipe with novel main pipe |
| GB8806638A GB2206173B (en) | 1987-06-26 | 1988-03-21 | Method of pipe replacement |
| CA000580574A CA1321479C (en) | 1987-06-26 | 1988-10-19 | Method of pipe replacement (no.1) |
| DE3835901A DE3835901C2 (en) | 1987-06-26 | 1988-10-21 | Procedure for replacing a pipe laid in the ground |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62160479A JPS646590A (en) | 1987-06-26 | 1987-06-26 | Method of replacing existing main pipe with novel main pipe |
| CA000580574A CA1321479C (en) | 1987-06-26 | 1988-10-19 | Method of pipe replacement (no.1) |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1321479C true CA1321479C (en) | 1993-08-24 |
Family
ID=25672186
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000580574A Expired - Fee Related CA1321479C (en) | 1987-06-26 | 1988-10-19 | Method of pipe replacement (no.1) |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS646590A (en) |
| CA (1) | CA1321479C (en) |
| DE (1) | DE3835901C2 (en) |
| GB (1) | GB2206173B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE69012106T2 (en) * | 1989-03-02 | 1994-12-22 | Ina Acquisition Corp | LINING OF PIPELINES AND CHANNELS. |
| GB2231118B (en) * | 1989-05-06 | 1992-12-16 | D J Ryan & Sons Limited | Pipeline replacement |
| JP4127577B2 (en) * | 1998-08-28 | 2008-07-30 | Ｊｆｅ工建株式会社 | Pull-out crushing device for buried pipe and method for renewing buried pipe using the same |
| AT505411B1 (en) * | 2007-10-15 | 2009-01-15 | Skrdla Ges M B H | METHOD FOR REPLACING PIPES |
| NL2014727B1 (en) * | 2014-04-29 | 2016-06-20 | Visser & Smit Bv | Remove underground pipe and replace with new one. |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3176344D1 (en) * | 1980-12-02 | 1987-09-10 | British Gas Corp | Improvements in the replacement of mains |
| JPS6396382A (en) * | 1986-10-13 | 1988-04-27 | 日本電信電話株式会社 | Method of renewing and pipe-increasing construction of existing buried pipe and pipe crushing instrument |
-
1987
- 1987-06-26 JP JP62160479A patent/JPS646590A/en active Granted
-
1988
- 1988-03-21 GB GB8806638A patent/GB2206173B/en not_active Expired - Lifetime
- 1988-10-19 CA CA000580574A patent/CA1321479C/en not_active Expired - Fee Related
- 1988-10-21 DE DE3835901A patent/DE3835901C2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| GB2206173B (en) | 1991-01-23 |
| GB8806638D0 (en) | 1988-04-20 |
| DE3835901C2 (en) | 1998-04-16 |
| GB2206173A (en) | 1988-12-29 |
| JPH0378513B2 (en) | 1991-12-13 |
| DE3835901A1 (en) | 1990-04-26 |
| JPS646590A (en) | 1989-01-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |