JPH0128171B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for removing a pipe that is part of a buried gas transport pipe, such as a city gas pipe, while continuing to transport gas through construction over several days. Concerning a method for replacing gas transport conduits with new pipes.

[Prior art]

Conventionally, as shown in FIG. 7A, new buried conduits 11b were installed along the entire length of the gas transport conduits 11 to be removed, 11a, in a construction process that lasted several days. As shown in FIG.
to shut off the gas transport conduit 11, then cut and remove both ends of the conduit 11a to be removed, connect the new buried conduit 11b to the gas transport conduit 11, and then remove the blocking bag 12 and install the new one. Buried conduit 1
1b was carried out, and then the conduit 11a to be removed was removed by construction work over several days, thereby suppressing the interruption of gas distribution from the gas transporting conduit 11 in as small a range as possible and in a short period of time.

[Problem that the invention seeks to solve]

However, the installation of the new buried conduit 11b and the removal of the conduit 11a to be removed require extensive excavation work, and the excavation work lengthens the construction period, causing traffic disturbances and disturbing the neighborhood. In addition, the construction costs were enormous due to the long range of excavation and backfilling, and the handling of large amounts of excavated and backfilling soil, leaving room for further improvement.

The purpose of the present invention is to greatly shorten the scope of excavation work while minimizing the interruption of gas distribution from gas transport conduits in as small an area as possible and in a short period of time, thereby greatly shortening the construction period and construction cost. The point is to save money.

[Means to solve the problem]

The characteristic means of the present invention is to excavate a section of the conduit to be removed of a unit length that can be replaced in one day's work at one end of the conduit to be removed, which is a part of the buried gas transport conduit, and to A first step of airtightly closing each of the conduit sections near both sides of the conduit section, and then cutting both ends of the removed conduit section and removing the removed conduit section; connecting to the airtightly closed conduit section that will not be removed; a second step of hermetically closing the new pipe to be used for the new pipe with an airtight closing stopper that is movably inserted therein, and hermetically closing the other cut portion of the airtightly closed conduit portion with a cup; a third step of installing a new pipe on the installation site of the removed conduit portion and connecting it to the conduit portion that will not be removed, and releasing the airtight blockage of both conduit portions caused by the first step, the connecting end side of the new pipe; A fourth step of moving the stopper from the stopper to the other end side and purging the air in the new pipe by the action of the stopper; A fifth step of airtightly closing the non-connecting end side of the new pipe with the stopper or cup. , and on the first day, and on each subsequent construction day, excavate a unit length of removed conduit that can be replaced in one day's work on the new pipe side of the conduit to be removed, and A sixth step of airtightly closing the conduit portion near one end of the removed conduit portion, and then cutting one end of the removed conduit portion and removing the removed conduit portion; airtightly closing the cut end of the said conduit portion with a cup; After that, in a seventh step of releasing the airtight blockage of the conduit section from the sixth step, a new pipe is installed at the site where the removed conduit section was installed and connected to the existing new pipe, and the stopper is installed on the same day. an eighth step of moving the new pipe to the free end side and purging the air inside the new pipe installed on the day by the action of the stopper; a ninth step of airtightly closing the new pipe installed on the day as in the fifth step; The purpose is to carry out the construction work including the construction process, and then, on the final construction day, connect the new pipe installed on that day to the part of the gas transport conduit that will not be removed, and its effects are as follows.

[Effect]

In other words, on each construction day, while preventing gas leakage from the gas transport conduit using stoppers, cups, or other means, a unit length of removed conduit is removed, and the installation site of the removed conduit is replaced. Because new pipes are installed, the excavation work area can be reduced by about half compared to the conventional technology described above, in which the new pipes are buried alongside the pipes to be removed.This greatly reduces the construction period and construction costs. It has become possible to achieve major savings.

Also, on each construction day, the installed new pipe is connected to the gas transport conduit and the stopper is moved to the free end side of the new pipe, so gas distribution using the installed new pipe is performed. In addition, in city gas pipelines, the remaining pipelines to be removed are often connected to other gas transportation pipelines, so interruptions in gas distribution from gas transportation pipelines should be kept as small and short as possible. It can be saved in time.

〔Effect of the invention〕

As a result, while taking full advantage of the advantage of suppressing the interruption of gas distribution from gas transport pipes to as small an area as possible and in a short period of time, the construction period is greatly shortened, thereby significantly reducing the negative impact on traffic and the disruption to the neighborhood. This method is extremely advantageous from an economic point of view due to the large reduction in construction costs, and an overall superior method for replacing gas transportation pipes has been obtained.

〔Example〕

Next, an embodiment will be shown with reference to FIGS. 1 to 6.

On the first day of construction, the following steps 1 to 5 will be completed.
Implement construction including construction process.

(1) First step As shown in Figure 1, the pipe P _-1 to be removed in range A, which is a part of the buried gas transport pipe
At P _-o , the removed conduit section P -1 of unit length a, which can be replaced in one day's work, is excavated as shown in Fig. 2A, and the removed conduit section P _-1 , which can be replaced in one day's work, is excavated as shown in Fig. 2A, and as shown in Fig. 2B, The conduit sections P' and P _- 2 near both sides of the removed conduit section P _- 1 are hermetically closed with rubber bags 1 which are inserted through the holes formed therein and then inflated, and then the removed conduit section P _-1 is Cut both ends and remove the removal conduit section P _-1 .

In addition, if the valve 1' is provided at an appropriate location, the drilling and bag insertion may be omitted and the valve 1' may be airtightly closed;
If there is a branch pipe in the removed conduit section P _-1 , the connection between both pipes should be released prior to removal.

(2) Second step As shown in Figure 3, move the new pipe P _0-1 to connect to the airtightly closed pipe section P', P _-2 that will not be removed, P'. It is airtightly closed with the airtight closing stopper 3 that can be inserted freely.
and the other of the airtightly closed conduit portions P′ and P _-2
The cut end of P _-2 is hermetically closed with cup 5.

In addition, two elastic seal members 3 are attached to the stopper 3.
A is provided, and the elastic seal member 3a is configured to be able to be expanded and contracted by supplying and discharging fluid through a hose 8 with a cable.

(3) Third step As shown in Figure 4, a new pipe P _0-1 is installed on the site where the removed pipe section P _-1 was installed, and the pipe section that will not be removed is
Connect to P' with a joint, remove the rubber bag 1 in each of the conduit sections P' and P _-2 , cover the hole with a plug 2, and release the airtight blockage caused by the first step.

Then, if necessary, close the end of the new pipe P _0-1 with cup 6 with valve V, and connect the new pipe from valve V.
Inject compressed air into P _0-1 and perform an airtight test on the new pipe P _0-1 .

(4) Fourth step As shown in Fig. 5, remove the cup 6, contract the elastic seal member 3a, and
, and move the stopper 3 from the connecting end of the new pipe P _0-1 to the other end of the new pipe P 0-1 while preventing leakage of transport gas by the action of the tongue piece 3b attached to the stopper 3 _. Purge the air inside ₁ .

(5) Fifth step As shown in FIG. 6, the non-connecting end side of the new pipe P _0-1 is hermetically closed by the stopper 3 or cup 6 made by expanding the elastic seal member 3a.

Furthermore, if necessary, connect the previously disconnected branch pipe to the new pipe P _0-1 .

Then, on each subsequent construction day, construction work including the 6th to 9th steps below will be carried out.

(6) 6th process: New existing pipes among pipes P _-2 to _{P -o} to be removed
P _0-1 ...On the P _0-o-2 or P _0-o-1 side, removed conduit section P _-2 of unit length a that can be replaced in one day of construction.
…In addition to excavating P _-o-1 or P _-o , the removed conduit part
P _-2 ... P _-o-1 or the conduit section P _-3 near one end of P _-o
... P _-o or P'' is hermetically closed with rubber bag 1 in the same manner as in Fig. 2 B, and then the removed conduit section P _-2 ...
Cut one end of P _-o-1 or P _-o and remove the conduit section P _-2 ...P _-o-1 or P _-o is removed.

(7) Seventh step The cut end of the conduit section P _-3 ...P _-o or P'' is hermetically closed with the cup 5 in the same manner as in Fig. 3, and then the rubber bag 1 is removed in the same manner as in Fig. 4. Then cover the hole with plug 2 and remove the conduit part by the 6th step.
P _-3 ...Remove the airtight blockage of P _-o or P''.

(8) 8th step Similar to Figure 5, new pipe P _0-2 ...P _0-o-1 or P _0-o
Install the removed conduit section P _-2 ...P _-o-1 or P _-o on the installation site and connect it to the existing new pipe P _0-1 ...P _0-o-2 or P _0-o-1 , New pipe P _0-2 with stopper 3 installed on the day...
P _0-o-1 or P _0-o is moved to the free end side, and the new pipe P _0-2 installed on the day...P _0-o-1 or P _0-o is drained from the tongue piece of stopper 3. Purge by the action of 3b.

(9) 9th process Similar to the 5th process shown in Figure 6, connect the non-connecting end of the new pipe P _0-2 ...P _0-o-1 or P _0-o installed on the day to the stopper 3 or Close it airtight with cup 6.

Then, on the final construction day, stopper 3
, and connect the new pipe P _0-o installed on the day to the part P'' of the gas transport conduit that will not be removed.

[Brief explanation of drawings]

1 to 6 are conceptual diagrams showing an embodiment of the present invention, and FIGS. 7A and 7B are conceptual diagrams of a conventional example. P _-1 ...P _-o ...Pipe section to be removed, P', P''...Pipe section not to be removed, P _0-1 to P _0-o ...New pipe, 3...Stopper, 5, 6...Cup .

Claims (1)

[Scope of Claims] 1. Conduit pipes P _-1 to _{P o} that are part of the buried gas transport pipes to be removed are replaced with new pipes P _0-1 to P ₀ while gas transport continues through multi-day construction work. _-o is a replacement construction method for gas transportation conduits, in which the removed conduit portion P _-1 of unit length a that can be replaced in one day's work on one end of the aforementioned conduits P _-1 to _{P o} to be removed. At the same time, the conduit sections P' and P -2 near both sides of the removed conduit section P _-1 are hermetically sealed, and then both ends of the removed conduit section P _-1 are cut and the removed conduit section P _-1 is excavated. The first step of removing P _- 1 is to move and manipulate the new pipe _P0-1 , which is to be connected to P', which is not to be removed out of the airtightly closed conduit sections P' and P _-2 , inside it. a second step of airtightly closing the new pipe with the inserted airtight closing stopper 3, and airtightly closing the cut end of the other P _- 2 of the airtightly closed conduit portions P' and P _-2 with a cup 5; P _0-1 is installed at the installation site of the removed conduit section P _-1 and connected to the conduit section P' that will not be removed,
and a third step of releasing the airtight blockage of both conduit portions P' and P _-2 caused by the first step, moving the stopper 3 from the connecting end side of the new pipe _P0-1 to the other end side, a fourth step of purging the air in the new pipe P _0-1 by the action of the stopper 3; a fifth step of airtightly closing the non-connecting end side of the new pipe P _0-1 with the stopper 3 and cup 6; , on the first day, and on each subsequent construction day, the existing new pipe P _0-1 ... P _0-o-2 or P _0- of the pipes P _-2 to P _o to be removed. Removed conduit section of unit length a that can be replaced in one day of construction on the _o-1 side P _-2 ...P _-o-1 or
Along with excavating P _-o , the removed conduit section P _-2 ...
After airtightly closing the conduit section P _-3 ...P _-o or P'' near one end of P _{-o -1} or P -o, the removed conduit section P _-2 ...
A sixth step of cutting one end of P _-o-1 or P _-o and removing the removed conduit portion P _-2 ...P _-o-1 or P _-o , the said conduit portion P _-3 ...P _{- o} or P'' is hermetically closed with the cup 5, and a seventh step of releasing the airtight closure of the conduit portion P _-3 ...P -o or P _' ' in the sixth step, the new pipe P _0-2 …P _0-o-1 or P _0-o as the removed conduit part
P _-2 ...P _-o-1 or P _-o is installed at the site where P -o was installed and connected to the existing new pipe P _0-1 ...P _0-o-2 or P _0-o-1 , and the stopper 3 be moved to the free end side of the new pipe P _0-2 ...P _0-o-1 or P _0-o installed on the day, and the new pipe P _0-2 ...P _0-o-1 or 8th step of purging the air in P _0-o by the action of the stopper 3, similar to the 5th step, the new pipe P _0-2 installed on the day
…The construction work including the ninth step of airtightly closing P _0-o-1 or P _0-o will be carried out, and on the final construction day, the new pipe P _0-o installed on that day will be removed from among the gas transport conduits. A method of replacing the gas transport pipe connected to the part P″ that will not be removed.