JP7510865B2 - Water pressure pipeline renewal method - Google Patents

Description

The present invention relates to a method for updating a penstock pipeline in a hydroelectric power plant to replace an existing penstock pipeline with a new penstock.

When the hydraulic pipelines at a hydroelectric power plant become deteriorated, the existing iron pipes must be removed and new iron pipes must be brought in and assembled. These tasks can be carried out by installing large-scale lifting equipment such as cable cranes or by constructing multiple temporary work platforms along the hydraulic pipelines, but either method requires a lot of equipment and materials and takes a long time, which increases costs.
On the other hand, Patent Document 1 discloses a method for removing an existing pipe, in which the upper half of an existing pipe (iron pipe) is divided in a circumferential direction (e.g., into quadrants) at a predetermined length in sequence from the downstream side to the upstream side, and each block of the divided upper half is repeatedly transported downstream by using the inner surface of the existing pipe (lower half) as a chute, and then the lower half of the existing pipe is divided in a circumferential direction (e.g., into quadrants) at a predetermined length in sequence from the upstream side to the downstream side, and each block of the divided lower half is repeatedly transported downstream by using the inner surface of the remaining existing pipe (lower half) on the downstream side.

Japanese Patent Application Laid-Open No. 61-192983

However, in Patent Document 1, a wire rope or other cable is described as a pulling means for preventing the divided blocks from sliding down, and the other end of the cable is unwound by a winding machine, but the mechanism and other materials and equipment required for pulling the blocks are not specifically specified. For example, when a winch is used as a winding machine, the winch itself is a large piece of equipment, and there is a problem that the work of transporting and installing it at the site is cumbersome. In addition, the wire rope used as the pulling means is difficult to bend, and the work of connecting and disconnecting is cumbersome, and it is heavy and difficult to handle. Furthermore, it is described that the existing iron pipe is divided into blocks by means of separation, melting, etc., but in order to carry out this, it is considered that a crane and a temporary platform for setting it up are required to support the blocks to be cut. Therefore, several temporary platforms need to be installed along the existing iron pipe, but since the existing iron pipe is not only exposed to the ground but also laid in a tunnel, and the work site is in the mountains, it is preferable to reduce the amount of materials and equipment brought into the site as much as possible. In addition, due to limitations in work (installation) space, it is difficult for large heavy machinery to enter the site, so it is desirable for each piece of equipment to be lightweight.
The present invention has been made in consideration of the above circumstances, and aims to provide a method for updating hydraulic pipelines that reduces the amount of equipment and materials transported to the work site, cuts down on preparatory work, eliminates the need for special work, improves work efficiency, and enables a significant shortening of construction time and reduction in costs.

The hydraulic pipeline renewal method according to the present invention, which is in accordance with the above-mentioned object, is a hydraulic pipeline renewal method for removing an existing iron pipe from a hydraulic pipeline of a hydroelectric power plant and installing a new iron pipe,
Midway along the longitudinal direction of the hydraulic pipeline, at least the upper half of the existing iron pipe is removed from a portion of the existing iron pipe that is exposed above ground to form an opening, and the existing iron pipe downstream and upstream of the opening is divided in the circumferential and axial directions of the existing iron pipe and transported to the opening and removed.

In the hydraulic pipeline renewal method according to the present invention, when the existing iron pipe is divided in the circumferential direction of the existing iron pipe, it is preferable that the existing iron pipe is divided into four parts, a ceiling part, both side parts, and a bottom part, and the divided ceiling part and both side parts are transported on and along the inner surface of the bottom part.

In the hydraulic pipeline renewal method according to the present invention, it is preferable that, after the divided ceiling and both side sections of the existing iron pipe downstream of the opening are removed, the bottom is divided in the axial direction from downstream to upstream, and the remaining upstream bottom section is transported along the inner circumferential surface of the inner circumferential surface to the opening and removed, and, after the divided ceiling and both side sections of the existing iron pipe upstream of the opening are removed, the bottom is divided in the axial direction from upstream to downstream, and the remaining downstream bottom section is transported along the inner circumferential surface to the opening and removed.

In the hydraulic pipeline renewal method according to the present invention, the opening has a downstream opening portion and an upstream opening portion formed respectively on the downstream and upstream sides of an existing intermediate fixing base that fixes the existing iron pipe by covering the outer periphery of the existing iron pipe with concrete, midway along the longitudinal direction of the hydraulic pipeline, and the existing iron pipe downstream of the opening portion may be divided and removed from the downstream opening portion, and the existing iron pipe upstream of the opening portion may be divided and removed from the upstream opening portion.

In the hydraulic pipeline renewal method according to the present invention, it is preferable that the new iron pipe is brought in in a sliced state from the location where the opening was formed after the existing iron pipe has been removed, and is transported sequentially downstream and upstream from the opening to be connected to the adjacent new iron pipes.

In the hydraulic pipeline renewal method according to the present invention, the transportation of the new iron pipe can be guided by multiple support stands temporarily installed along the longitudinal direction of the hydraulic pipeline.

In the hydraulic pipeline renewal method according to the present invention, the portion of the new iron pipe that is curved downstream of the hydraulic pipeline and fixed to the existing downstream fixed base is preferably divided into three in the circumferential direction and has a bottom wall and left and right pivot walls that are rotatably connected to both sides of the width of the bottom wall, and each of the pivot walls is folded toward the bottom wall and transported from the opening to the downstream installation position and assembled into a circular tube shape.

In the hydraulic pipeline renewal method according to the present invention, it is preferable that a single common crane is used to transport the existing iron pipe and the new iron pipe, to remove the existing iron pipe, and to bring in the new iron pipe.

In the hydraulic pipeline renewal method according to the present invention, the crane and chain block may be used in combination to transport the existing iron pipe and the new iron pipe.

In the hydraulic pipeline renewal method according to the present invention, it is preferable that the portion of the existing iron pipe that is installed inside the tunnel is suspended by a tunnel chain block that is attached to the inner surface of the ceiling of the tunnel and divided.

In the hydraulic pipeline renewal method according to the present invention, it is preferable that the portion of the existing iron pipe that is exposed above ground is divided by being suspended from a ground chain block attached to a gate-shaped frame that is installed so as to surround the periphery of the existing iron pipe.

In the hydraulic pipeline renewal method according to the present invention, at least the upper half of the existing iron pipe is removed from a portion of the existing iron pipe exposed above ground midway along the longitudinal direction of the hydraulic pipeline to form an opening, and the existing iron pipe downstream and upstream of the opening is divided in the circumferential and axial directions of the existing iron pipe and transported to the opening for removal. Therefore, even if the hydraulic pipeline is long or curved along the way, the work of removing the existing iron pipe and the work of installing the new iron pipe can be carried out efficiently in a short time.

In the hydraulic pipeline renewal method according to the present invention, when an existing iron pipe is divided in the circumferential direction of the existing iron pipe, it is divided into four parts, the ceiling, both side parts, and the bottom, and when the divided ceiling and both side parts are transported on and along the inner circumferential surface of the bottom, the bottom can be effectively used to efficiently transport the divided ceiling and both side parts, eliminating the need to use separate chutes or transport carts, and reducing the amount of equipment and materials brought to the work site.

In the hydraulic pipeline renewal method according to the present invention, the existing iron pipe downstream of the opening has its divided ceiling and both side sections removed, and then its bottom is divided in the axial direction from downstream to upstream, and then transported along the inner circumferential surface of the remaining upstream bottom section to the opening and removed; and the existing iron pipe upstream of the opening has its divided ceiling and both side sections removed, and then its bottom is divided in the axial direction from upstream to downstream, and then transported along the inner circumferential surface of the remaining downstream bottom section to the opening and removed. In this case, the remaining bottom section can be effectively utilized, and the divided bottom section can be transported efficiently, resulting in excellent workability and labor savings.

In the hydraulic pipeline renewal method according to the present invention, the opening has a downstream opening portion and an upstream opening portion formed respectively on the downstream and upstream sides of an existing intermediate fixing base that fixes the existing iron pipe by covering the outer periphery of the existing iron pipe with concrete midway along the longitudinal direction of the hydraulic pipeline, and when the existing iron pipe downstream of the opening is divided and removed from the downstream opening portion and the existing iron pipe upstream of the opening is divided and removed from the upstream opening portion, the existing iron pipe removal work can be performed reliably and efficiently even if the outer periphery of some of the existing iron pipes is covered with concrete and fixed to the intermediate fixing base.

In the hydraulic pipeline renewal method according to the present invention, after the existing iron pipe has been removed, the new iron pipe is brought in in a sliced state from the location where the opening was formed, and then transported sequentially downstream and upstream from the opening to connect with other adjacent new iron pipes, allowing the installation work of the new iron pipe to be carried out efficiently in a short time.

In the hydraulic pipeline renewal method according to the present invention, when the transport of a new iron pipe is guided by multiple support stands temporarily installed along the longitudinal direction of the hydraulic pipeline, the transport work of the new iron pipe can be carried out efficiently, resulting in excellent labor savings.

In the hydraulic pipeline renewal method according to the present invention, the part of the new iron pipe that is curved downstream of the hydraulic pipeline and fixed to the existing downstream fixed base is divided into three parts in the circumferential direction and has a bottom wall and left and right pivoting walls that are rotatably connected to both sides of the width of the bottom wall, and when each pivoting wall is folded toward the bottom wall and transported from the opening to the installation position downstream and assembled into a circular tube, even if the pipeline is curved, the new iron pipe can be transported reliably to the installation position and installation work can be carried out efficiently.

In the hydraulic pipeline renewal method according to the present invention, when a single common crane is used to transport the existing iron pipe and the new iron pipe, remove the existing iron pipe, and bring in the new iron pipe, installation space and working space can be secured even at a site in the mountains, work efficiency can be improved, and a significant shortening of construction time and cost can be achieved.

In the hydraulic pipeline renewal method according to the present invention, when a crane and a chain block are used in combination to transport the existing iron pipe and the new iron pipe, the chain block is easy to transport to the site and to operate, which can greatly improve workability.

In the hydraulic pipeline renewal method according to the present invention, when the portion of the existing iron pipe installed inside the tunnel is suspended by a tunnel chain block attached to the inner surface of the tunnel ceiling and divided, the division work of the existing iron pipe inside the tunnel can be carried out safely and efficiently.

In the hydraulic pipeline renewal method according to the present invention, when the portion of the existing iron pipe that is exposed above ground is suspended by a ground chain block attached to a gate-shaped frame that is installed so as to surround the periphery of the existing iron pipe and divided, the work of dividing the existing iron pipe on the ground can be carried out safely and efficiently.

1 is a partial cross-sectional side view showing a hydraulic pipeline of a hydroelectric power plant to which a hydraulic pipeline renewal method according to one embodiment of the present invention is applied. FIG. 2 is an end view of a main portion showing a process of forming an opening in the water pressure pipeline renewal method. FIG. 2 is a partial cross-sectional side view showing an opening formed in the water pressure pipeline renewal method. FIG. 2 is a partial cross-sectional side view showing the process of removing the ceiling portion of the existing iron pipe downstream of the opening in the water pressure pipeline renewal method. FIG. 2 is an end view of a main part showing the process of removing the ceiling portion of the existing iron pipe downstream of the opening in the water pressure pipeline renewal method. FIG. 2 is a cross-sectional side view of a main portion of a transport chain block used in the water pressure pipeline renewal method. FIG. 2 is a partial cross-sectional side view showing the process of removing a side portion of an existing iron pipe downstream from an opening in the water pressure pipeline renewal method. FIG. 2 is an end view of a main portion showing the process of removing the side portion of the existing iron pipe downstream from the opening in the water pressure pipeline renewal method. FIG. 2 is a partial cross-sectional side view showing a process of installing a new cylindrical iron pipe inside a downstream fixed base in the water pressure pipeline renewal method. FIG. 13 is an end view of a main part showing the process of installing a new foldable iron pipe inside the downstream fixed base in the water pressure pipeline renewal method. This is an end view of a main part showing the process of removing the bottom of the existing iron pipe downstream from the opening in the water pressure pipeline renewal method. FIG. 2 is a partial cross-sectional side view showing a process of installing a new iron pipe downstream of the opening in the water pressure pipeline renewal method. FIG. 2 is a partial cross-sectional side view showing the process of removing the ceiling portion of the existing iron pipe upstream of the opening in the water pressure pipeline renewal method. FIG. 2 is an end view of a main part showing the process of removing the ceiling portion of the existing iron pipe upstream of the opening in the water pressure pipeline renewal method. FIG. 2 is a partial cross-sectional side view showing a process of removing a side portion of an existing iron pipe upstream of an opening in the water pressure pipeline renewal method. FIG. 2 is an end view of a main part showing the process of removing the side portion of the existing iron pipe upstream of the opening in the water pressure pipeline renewal method. FIG. 2 is a partial cross-sectional side view showing the process of removing the bottom of the existing iron pipe upstream of the opening in the water pressure pipeline renewal method. FIG. 11 is a partial cross-sectional side view showing a process of removing an existing iron pipe inside an intermediate fixing base in the water pressure pipeline renewal method. FIG. 2 is a partial cross-sectional side view showing the state in which installation of a new iron pipe has been completed in the water pressure pipeline renewal method.

Next, with reference to the attached drawings, an embodiment of the present invention will be described for better understanding of the present invention.
A method for updating a penstock pipeline according to an embodiment of the present invention is used when updating an existing iron pipe 12 of a penstock pipeline 11 in a hydroelectric power plant 10 shown in FIG. 1 with a new iron pipe.
As shown in Fig. 1, the penstock 11 connects a water tank (regulating reservoir) 13 on the upstream side and a water turbine (not shown) on the downstream side, and supplies water stored in the water tank 13 to the water turbine. A part of the existing iron pipe 12 is laid inside a tunnel 14. An existing upstream fixing base 16, an intermediate fixing base 17 and a downstream fixing base 18 are provided at the upstream end, midway along the longitudinal direction and downstream end of the penstock 11 (existing iron pipe 12), respectively, which fix the existing iron pipe 12 by covering the outer periphery of the existing iron pipe 12 with concrete. Furthermore, key points in the longitudinal direction of the existing iron pipe 12 are slidably supported by a plurality of small supports 20.

First, in order to remove the existing iron pipe 12, at least the upper half of the existing iron pipe 12 (here, the upper 2/3 circumference, hatched portion in Figs. 1 and 2) is removed from a part of the existing iron pipe 12 exposed on the ground midway in the longitudinal direction of the penstock 11, to form an opening 21 as shown in Fig. 3. At this time, as shown in Figs. 1 and 3, since the midway of the longitudinal direction of the penstock 11 is fixed by the intermediate fixing base 17, a downstream opening portion 21a and an upstream opening portion 21b are formed on the downstream side and the upstream side of the intermediate fixing base 17, respectively. As a result, the existing iron pipes 12a, 12b downstream and upstream of the opening 21 (excluding the portions fixed by the downstream fixing base 18 and the upstream fixing base 16) are divided in the circumferential direction and the axial direction, respectively, and transported to the downstream opening portion 21a and the upstream opening portion 21b, and taken out from the downstream opening portion 21a and the upstream opening portion 21b.
The portion to be removed from the existing iron pipe 12 when forming the opening 21 (the downstream opening portion 21a and the upstream opening portion 21b) is suspended in advance by a hook 24 attached to the tip of a boom 23 of a crane 22 so as to be capable of ascending and descending, as shown in FIG. 1, so that it does not fall during division, and is lifted up and removed by the crane 22 after division. At this time, by leveling the upper part of the tunnel 14 near the opening 21 and setting up the crane 22, the existing iron pipe 12 can be efficiently removed and the new piping can be brought in. A small mobile crane (e.g., a 25 t crawler crane) is preferably used as the crane, but is not limited thereto, and may be made as large as possible as long as it can be brought in and set up at the work site.

In this embodiment, the area removed to form the opening 21 is the upper 2/3 of the entire circumference of the existing iron pipe 12, excluding the lower 1/3 area supported by the small support 20, as shown in Figure 2. By forming the opening 21 (downstream opening portion 21a and upstream opening portion 21b), the existing iron pipes 12a and 12b, which will later be divided in the circumferential and axial directions downstream and upstream of the opening 21, can be smoothly transported out. The shape and size of the openings (downstream opening portion and upstream opening portion) can be appropriately selected within the range in which the divided existing iron pipe can be transported out, but it is preferable to remove at least the upper half of the existing iron pipe 12.

Next, as shown in Figures 4 and 5, the ceiling part 26 (hatched part in Figures 4 and 5) of the existing iron pipe 12a (installed in the tunnel 14 in this case) downstream of the opening 21 is divided. At this time, the ceiling part 26 is divided while hanging from a tunnel chain block 28 attached to the inner ceiling surface 27 of the tunnel 14 in advance, and after division, it is placed on the bottom part 29 of the existing iron pipe 12a. In addition, slide shoes 31 are attached via support members 30 to both sides in the width direction of the lower side of the ceiling part 26, and a connector 34 for connecting a transport chain block 33 shown in Figure 6 is attached to the center of the width direction of the upper surface side. As a result, the divided ceiling part 26 is smoothly transported along the inner surface of the bottom part 29 to the opening 21 and taken out from the downstream opening part 21a. The division and removal of the ceiling part 26 are performed sequentially from the upstream side to the downstream side, and the axial length at the time of division can be selected appropriately. For example, the ceiling 26 may be divided into sections that can be removed from the downstream opening 21a from the beginning and transported upstream in sequence, or the ceiling 26 may be divided into sections that are longer than the axial length of the downstream opening 21a (for example, 2 to 3 times the axial length of the downstream opening 21a) and transported upstream, and then repeatedly divided below the downstream opening 21a into sections of approximately the same length as the axial length of the downstream opening 21a. Therefore, the number and arrangement of the tunnel chain blocks 28 and slide shoes 31 can be selected appropriately depending on the axial length of the ceiling when it is divided, but it is preferable to install at least two axial locations (front and back), two on each side, for a total of four. The chain blocks 33 can be attached using the peripheral wall of the intermediate fixing base 17.

After the entire ceiling portion 26 of the existing iron pipe 12a is removed as described above, the two side portions 35a, 35b (hatched portions in FIGS. 7 and 8) are divided as shown in FIGS. 7 and 8. First, one side portion 35a is divided while being suspended by the tunnel chain block 28, and after division, it is placed on the bottom portion 29 of the existing iron pipe 12a. At this time, slide shoes 36 are attached to both sides in the width direction on the outer periphery side of the side portion 35a, and a connector 34 is attached to the center in the width direction on the inner periphery side, similar to the ceiling portion 26. As a result, the divided side portion 35a is smoothly transported along the inner periphery surface of the bottom portion 29 to the opening 21 and taken out from the downstream opening portion 21a. Here, the procedure for dividing and transporting the side portion 35a in the axial direction is the same as that of the ceiling portion 26 described above, so a description thereof will be omitted. The procedure for dividing and transporting the other side portion 35b is the same as that of the side portion 35a, so a description thereof will be omitted. It is preferable to alternately divide and remove one side portion 35a and the other side portion 35b in the axial direction by a specified length, but it is also possible to first remove all of one side portion 35a and then remove the other side portion 35b.
In this way, by using the bottom 29 of the existing iron pipe 12, which is divided circumferentially, to transport the ceiling portion 26 and both side portions 35a, 35b, there is no need to use a separate transport cart, etc., and the amount of equipment and materials transported to the work site can be reduced.

Next, the portion of the existing iron pipe 12 that is fixed to the downstream fixing base 18 (the shaded portion in FIG. 7) is removed. This portion is curved and narrows toward the downstream end, so it is dismantled together with the surrounding concrete inside the downstream fixing base 18, collected in a bucket or the like, and carried out from the downstream end. At this time, the water turbine and generator have been temporarily removed.
Next, as shown in Fig. 9, a new iron pipe to be installed inside the downstream fixed base 18 is carried in through the opening 21 (downstream opening portion 21a) by the crane 22. At this time, since the inside (hollow portion) of the downstream fixed base 18 is curved and the downstream end side is partially narrowed in diameter, a cylindrical new iron pipe 38 or a foldable new iron pipe 39 shown in Fig. 10 is used depending on the installation location.
10, the new iron pipe 39 is divided into three in the circumferential direction and has a bottom wall 40 and left and right rotating walls 41 rotatably connected to both sides in the width direction of the bottom wall 40, and the height can be lowered by folding each rotating wall 41 toward the bottom wall 40, so that the new iron pipe 39 can pass through places where the cylindrical new iron pipe 38 cannot pass through. Therefore, the new iron pipe 39 is transported to the installation position downstream with each rotating wall 41 folded toward the bottom wall 40, and assembled into a circular pipe shape.
The new iron pipes 38, 39 are both transported to the downstream fixed platform 18 by utilizing the bottom 29 of the existing iron pipe 12a, and the above-mentioned transport chain block 33 is used for transport. The new iron pipe 39 can be transported smoothly by placing it on a transport cart 42. In this embodiment, the connector 34 for connecting the chain block 33 is attached to the center in the width direction on the upper surface side of the bottom wall 40, but it may also be attached to the transport cart.

Next, the bottom 29 (hatched portion in FIG. 9) of the existing iron pipe 12a is removed. The bottom 29 is successively divided in the axial direction from the downstream side to the upstream side, and as shown in FIG. 11, is transported along the inner circumferential surface of the remaining upstream bottom 29 to the opening 21 and removed. At this time, the bottom 29 is also divided while suspended by the tunnel chain block 28, similar to the above-mentioned ceiling portion 26 and both side portions 35a, 35b. Since the above-mentioned connector 34 is attached to the center of the width of the inner circumferential (upper) side of the bottom 29, the divided bottom 29 can be placed on the upstream bottom 29 and transported by connecting the transport chain block 33 and pulling it upstream.
In this manner, the bottom portion 29 is entirely removed, and the removal of the existing iron pipe 12a is completed.

Next, as shown in FIG. 12, the new iron pipe 44 is brought in in a sliced state from the location where the opening 21 (downstream opening portion 21a) was formed, and is transported downstream from the opening 21 in sequence, and is connected to the other adjacent new iron pipes 44 and installed. The new iron pipes 44 brought in by the crane 22 may be transported downstream one by one by the chain block 33 and connected to the other new iron pipes 44 that were previously installed, or may be connected to the other new iron pipes 44 near the entrance (upstream end) of the tunnel 14, and then transported downstream all together and further connected to the other new iron pipes 44 that were previously installed. At this time, by temporarily setting up a support stand 45 along the longitudinal direction of the hydraulic pipeline 11 at the location where the small support stand 20 is not installed at the delivery position of the new iron pipe 44, the new iron pipe 44 can be reliably supported and guided, and the transport work can be performed smoothly. In addition, by attaching two or three slide shoes to the periphery of the upstream end of the small support 20 along its inner surface (circumferential direction), and attaching a slide rail to the outer surface of the bottom side of the new iron pipe 44, the new iron pipe 44 can be moved smoothly along the axial direction of the small support 20.

Next, the existing iron pipe 12b upstream of the opening 21 (upstream opening portion 21b) is removed. First, the ceiling portion 46 (hatched portion in Figs. 13 and 14) is removed. Unlike the case of removing the ceiling portion 26 of the existing iron pipe 12a, the ceiling portion 46 is divided and removed sequentially from the downstream side to the upstream side. Since the existing iron pipe 12b is exposed on the ground, instead of the tunnel chain block 28 (see Fig. 5), as shown in Fig. 14, it is divided while suspended by a ground chain block 48 attached to a gate-shaped frame 47 installed to surround the outer periphery of the existing iron pipe 12b, and after division, it is placed on the bottom portion 49 of the existing iron pipe 12b. Then, by using the same support member 30, slide shoe 31 and connector 34 as in the case of the ceiling portion 26, it is smoothly transported along the inner periphery of the bottom portion 49 to the opening 21 and taken out from the upstream opening portion 21b. As shown in FIG. 13, the chain block 50 for transporting the existing iron pipe 12b is attached to the entrance (upstream) side of the upstream fixed platform 16 (for example, at an appropriate position in the water tank 13), and direction changes and route selection can be performed using a chain pulley 51 that is appropriately installed along the route to the connector 34.

After removing the entire ceiling portion 46 of the existing iron pipe 12b as described above, the side portions 53a, 53b (hatched portions in Figs. 15 and 16) are removed as shown in Figs. 15 and 16. However, unlike the case where the side portions 35a, 35b of the existing iron pipe 12a are removed, the side portions 53a, 53b are divided and transported sequentially from the downstream side to the upstream side. Note that, except that a ground chain block 48 is used instead of a tunnel chain block 28 (see Fig. 8) when dividing the side portions 53a, 53b, and a chain block 50 is used when transporting the side portions 53a, 53b, the procedure is the same as that when dividing and transporting the side portions 35a, 35b of the existing iron pipe 12a, so a description thereof will be omitted.
Next, as shown in Fig. 17, the portion of the existing iron pipe 12 that is fixed to the upstream fixing base 16 (the shaded portion in Fig. 17) is removed. This portion is dismantled together with the surrounding concrete inside the upstream fixing base 16, and is collected in a bucket or the like, and is transported by a transport chain block 50 to the location where the opening 21 (upstream opening portion 21b) was formed.
Next, the bottom portion 49 (hatched portion in FIG. 17) of the existing iron pipe 12b is removed. The bottom portion 49 is successively divided in the axial direction from the upstream side to the downstream side, and is transported along the inner circumferential surface of the remaining downstream-side bottom portion 49 to the opening 21 and removed. The procedure is the same as that for dividing and transporting the bottom portion 29 of the existing iron pipe 12a, except that the ground chain block 48 shown in FIGS. 14 and 16 is used to divide the bottom portion 49 and the chain block 50 is used to transport the bottom portion 49, and therefore a description thereof will be omitted.

After removing the entire bottom 49 of the existing iron pipe 12b in the above manner, the portion of the existing iron pipe 12 that is fixed to the intermediate fixing base 17 (the shaded portion in FIG. 18) is removed as shown in FIG. 18. This portion is dismantled together with the surrounding concrete inside the intermediate fixing base 17 and collected with a bucket or the like, and carried out by crane 22 from the location where the opening 21 (downstream opening portion 21a) was formed.
Next, as shown in Fig. 19, new iron pipes 55-60 are installed between the outlet (downstream side) of the upstream fixed table 16 and the inlet (upstream end) of the new iron pipe 44 that is the most upstream pipe that has been installed previously. Here, the new iron pipes 55-58 are carried in a sliced state from the place where the opening 21 (downstream opening portion 21a or upstream opening portion 21b) was formed, and are transported upstream in sequence to be connected to the other adjacent new iron pipes 56-58. At this time, the transportation of the new iron pipes 56-58 can be guided by a plurality of support tables 45 that are temporarily installed in places where the small support tables 20 are not installed along the longitudinal direction of the penstock 11, and the new iron pipes 56-58 can be arranged in the predetermined positions. In addition to the new straight iron pipe 55, a new iron pipe 56 formed in a trapezoidal shape in a side view and installed at the curved part of the upstream fixed base 16, a new tapered iron pipe 57, and a new iron pipe 58 formed to be expandable in the axial direction are appropriately combined and installed at a predetermined position. Finally, a short new iron pipe 59 and a new iron pipe 60 expandable in the axial direction are carried into the place where the downstream opening portion 21a was formed, and the gaps between the front and rear (upstream and downstream) new iron pipes 57 and 44 are adjusted and connected to each other, completing the renewal work. It is not necessary that all the straight new iron pipes 55 have the same axial length, and pipes of different lengths may be combined. The number and arrangement of the other new iron pipes 57 to 60 can also be selected appropriately.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations described in the above embodiments, and also includes other embodiments and variations that can be considered within the scope of the matters described in the claims.
For example, the procedures for removing the existing iron pipe and installing the new iron pipe do not have to be as described in the above embodiment, and some of the steps may be rearranged or multiple steps may be performed simultaneously (in parallel).
In the above embodiment, a crane and a chain block are used in combination to transport the existing and new iron pipes, but it is also possible to use only a crane without using a chain block. When using only a crane, a chain connected to the hook of the crane on one side is placed along a route on which chain pulleys for changing direction are installed at key points, and the other side of the chain is connected to the existing or new iron pipe to be transported, and the pipe can be lifted or sent out by moving the hook up and down (raising and lowering).

10: Hydroelectric power plant, 11: Penstock, 12, 12a, 12b: Existing iron pipe, 13: Water tank, 14: Tunnel, 16: Upstream fixed base, 17: Intermediate fixed base, 18: Downstream fixed base, 20: Small support base, 21: Opening, 21a: Downstream opening position, 21b: Upstream opening position, 22: Crane, 23: Boom, 24: Hook, 26: Ceiling, 27: Ceiling inner surface, 28: Tunnel chain block, 29: Bottom, 30: Support member, 31: Slide shoe, 33: Chain block, 34: Connector, 35a, 35b: Side, 36: Slide shoe, 38, 39: New iron pipe, 40: Bottom wall, 41: Rotating wall, 42: Transport cart, 44: New iron pipe, 45: Support, 46: Ceiling, 47: Gate frame, 48: Ground chain block, 49: Bottom, 50: Chain block, 51: Chain pulley, 53a, 53b: Side, 55-60: New iron pipe

Claims (11)

A method for updating a hydraulic pipeline by removing an existing iron pipe from a hydraulic pipeline of a hydroelectric power plant and installing a new iron pipe, comprising the steps of:
a hydraulic pipeline renewal method comprising the steps of: removing at least the upper half of the existing iron pipe from a portion of the existing iron pipe exposed above ground midway in the longitudinal direction of the hydraulic pipeline, to form an opening; and dividing the existing iron pipe downstream and upstream of the opening in the circumferential and axial directions of the existing iron pipe, transporting it to the opening and removing it. A water pressure pipeline renewal method according to claim 1, characterized in that when the existing iron pipe is divided in the circumferential direction of the existing iron pipe, it is divided into four parts, a ceiling part, both side parts, and a bottom part, and the divided ceiling part and both side parts are transported on and along the inner surface of the bottom part. A hydraulic pipeline renewal method according to claim 2, characterized in that, after the divided ceiling and both side sections of the existing iron pipe downstream of the opening are removed, the bottom is divided in the axial direction from downstream to upstream, and the remaining upstream bottom section is transported along the inner circumferential surface of the inner circumferential surface to the opening and removed, and, after the divided ceiling and both side sections of the existing iron pipe upstream of the opening are removed, the bottom is divided in the axial direction from upstream to downstream, and the remaining downstream bottom section is transported along the inner circumferential surface to the opening and removed. A method for updating a hydraulic pipeline according to any one of claims 1 to 3, characterized in that the opening has a downstream opening portion and an upstream opening portion formed respectively on the downstream and upstream sides of an existing intermediate fixing base that fixes the existing iron pipe by covering the outer periphery of the existing iron pipe with concrete midway along the longitudinal direction of the hydraulic pipeline, and the existing iron pipe downstream of the opening portion is divided and removed from the downstream opening portion, and the existing iron pipe upstream of the opening portion is divided and removed from the upstream opening portion. A method for updating a hydraulic pipeline according to any one of claims 1 to 4, characterized in that the new iron pipe is brought in in a sliced state from the location where the opening was formed after the existing iron pipe has been removed, and is transported sequentially downstream and upstream from the opening to be connected to the adjacent new iron pipe. The water pressure pipeline renewal method according to claim 5, characterized in that the transportation of the new iron pipe is guided by a plurality of support stands temporarily installed along the longitudinal direction of the water pressure pipeline. A method for updating a hydraulic pipeline according to any one of claims 1 to 4, characterized in that the part of the new iron pipe that is curved downstream of the hydraulic pipeline and fixed to the existing downstream fixing base is divided into three parts in the circumferential direction and has a bottom wall and left and right rotating walls that are rotatably connected to both sides of the width direction of the bottom wall, and each of the rotating walls is folded toward the bottom wall and transported from the opening to a downstream installation position and assembled into a circular pipe shape. A hydraulic pipeline renewal method according to any one of claims 1 to 7, characterized in that a single common crane is used to transport the existing iron pipe and the new iron pipe, to remove the existing iron pipe, and to bring in the new iron pipe. The hydraulic pipeline renewal method according to claim 8, characterized in that the crane and chain block are used in combination to transport the existing iron pipe and the new iron pipe. A method for updating a hydraulic pipeline according to any one of claims 1 to 9, characterized in that the portion of the existing iron pipe installed inside the tunnel is suspended by a tunnel chain block attached to the inner ceiling surface of the tunnel and divided. A method for updating a hydraulic pipeline according to any one of claims 1 to 10, characterized in that the portion of the existing iron pipe that is exposed above ground is suspended by a ground chain block attached to a gate-shaped frame that is installed so as to surround the periphery of the existing iron pipe and divided.

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