JPS6360393A - Pressure conduit tunnel made of precast - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a precast pressure waterway tunnel used as a headrace for hydroelectric power generation. In order to eliminate the disadvantages of casting on site, these parts were precast and molded separately into small parts, and were devised so that they could be efficiently assembled into a tunnel inside a narrow tunnel in another mountain.

(Conventional technology) Conventional pressure tunnels are built using a cast-in-place method by incorporating formwork into a tunnel in the ground.The cross-sectional area of the excavation is large, and cracks are likely to occur due to the soil and internal pressure. There are various problems that require long-term curing.

In order to solve such conventional problems, it is possible to mold the bottom plate and the left and right side plates into two or three parts using a precast method, and to assemble them in the mine shaft and to introduce prestress. Most desirable,
Special measures are required to efficiently assemble and introduce prestressing in narrow tunnels.

(Problems to be Solved by the Invention) This invention is devised so that members can be efficiently assembled within a tunnel, and the work of introducing prestress can be performed within the assembled tunnel members. .

(Means for Solving the Problems) The structure of the present invention for solving the above problems consists of a pre-shaped bottom plate 3 and an arch-shaped base 5 joined to the left and right sides 2° 2 of the bottom plate 3. A PC steel material 15 is disposed inside the left and right side plates 6 and in the left and right parts 2, 2 along the arched direction passing through the joint portion, and a large number of sets of the left and right side plates 6 and the bottom plate 3 are formed. are joined in the longitudinal direction, and PC5 material 1
In the pressure channel tunnel where the left and right sides 'Fi6 and the bottom plate 3 are connected to each other, the fixing seats 18 and 19 of the PC steel material 15 are placed between the left and right sides 2 degrees 2. This is a precast pressure water tunnel installed at the bottom of the interior.

(Function) The base portions 5 of the left and right side plates 6 and the left and right portions 2.2 of the bottom plate 3 are joined to each other, and the PC steel material 1 is arranged along the arched direction.
By tensioning 5, the left and right side plates 6 and the bottom plate 3 are firmly connected to each other with a large compressive force, and at the same time, prestress is introduced in the arched direction.

The tensioning operation of the PC steel material 15 in the circumferential direction is performed using the fixing seat 18.19 provided at the lower inner side of the left and right parts 2.2 of the bottom plate 3, and the PCt material 15 pulled out from the fixing seat 18.19.
Since the bottom plate 3 is laid in the tunnel 27, the left and right side plates 6 are joined to the bottom plate 3, and inside the left and right side plates 6 and the bottom plate 3, which are combined in an arch shape, the above p,
c) Tensioning work of the steel material 15 can be performed.

This eliminates the need for a special working space for tensioning the PC9al material 15, and eliminates the waste of having to make the excavation section of the tunnel 27 particularly thick.

(Example) Next, one embodiment of the present invention will be described based on the drawings.

As shown in the front view in Fig. 1, the left side in Fig. 2, the right side in Fig. 3, and the plan view in Fig. 4, the left and right parts 2.2 of the flat bottom 1 are The bottom plate 3 standing up from the base plate 3 and its upper part 4.4 are joined together to form an arch shape, and its base 5°5 is formed so that it can be joined to the left and right parts 2.2 of the bottom plate 3. The left and right side plates 6.6 and
It is molded using the precast method.

Both the bottom plate 3 and the left and right side plates 6.6 are shaped to have short lengths for ease of handling such as transportation.

As is clear from the perspective view shown in FIG. 5, sheath tubes 7, 7 and 8.
8, one of the sheath tubes 7, 7 is disposed near the longitudinal center of the left and right side plates 6, and the other sheath tube 8.8 is disposed on the outside in the longitudinal direction, respectively, and A sheath tube 9 is provided near the base portion 5, and a sheath tube 10 is provided in the base portion 5, extending along the longitudinal direction of the left and right side plates 6.

Sheath pipes 11, 11 and 12, 12 are provided on the left and right parts 2 of the bottom plate 3 at positions where they can communicate with the sheath pipes 7 and 8 of the left and right side plates 6, respectively, with the left and right parts 2 joined to the base 5. A sheath tube 13 and a sheath tube 14 and 14 are provided, respectively, passing through the left and right parts 2 in the longitudinal direction, and sheath pipes 14 and 14 passing through the bottom part 1 in the left and right direction.

A fixing plate 16 for fixing the left-right PCi material 15 inserted into the left-right sheath tube 14 is fixed to, for example, a concave fixing seat 17 provided on the outside of the corner of the bottom portion 1.
.
and 19, and for example concave fixing plates 20 and 21.21 are also provided on the outer side of the upper part 4.4 of the left and right side plates 6, respectively.
Concave fixing seats 22 and 23 are provided on the inner side of one of the left and right side plates 6, respectively, and a concave fixing seat 24 is provided on one of the several bottom plates 3 of the left and right sides 2. It is located inside.

The left and right side plates 6, 6 precast in this way
and the bottom plate 3, as illustrated in FIG. The upper end of this PC steel material is fixed to the fixing plate 16 of the fixing seat 20 by inserting the
1 insert the PC steel materials 15 into each other, fix the upper ends of these PC steel materials 15 to the fixing plate 16 of the fixing seat 21, and use the tensioning device 25 to pull these PC steel materials 15 from the fixing seats 18 and 19 side. If the four circumferential PC steel members 15 are fixed to the fixing plates 16 of the fixing seats 18 and 19 of the bottom plate 3 by applying tension, the left and right side plates 6.6 will be joined to each other at the upper part 4°4. The left and right side plates 6.6 and the bottom plate 3 are joined together at the base portion 5 and the left and right portions 2 to form one arch-shaped tunnel unit 26a, and a prestress is applied along this arch shape to the tunnel unit. A large number of tunnel units 26a are joined to each other in the front-rear direction, and the sheath pipes 9, 1
By tensioning the PC steel material 15 inserted through 0.13 mm, the tunnel units 26a are connected to each other to form a tunnel 26 of a desired length, and this tunnel 26
, a longitudinal prestress will be introduced.

Next, the tunnel construction procedure will be explained. Mine shaft 27 in the ground
As shown in the side view in FIG. 6, the bottom plate 3 is laid in the longitudinal direction inside the tunnel 27, and the longitudinal PCm material 15 is inserted into the longitudinal sheath 13 in the left and right parts 2. Using the tensioning device 25, as shown in the side view in FIG.
By tensioning the steel material 15, the respective bottom plates 3 are joined together and a prestress is introduced in the longitudinal direction.

Next, as shown in FIG.
and inject grout into the sheath pipe 13 as well.

As shown in the front view in Fig. 9, the left and right side plates 6.6
The left and right side plates 6,6 are carried into the tunnel 27 using an assembly machine 30 that can support the inner side of the bottom plate 3, and the left and right side plates 6.6 are attached to the left and right sides 2.2 of the bottom plate 3 from the back side as shown in Fig. 1O. When the base portion 5 of the left and right side plates 6, 6 are joined together, the upper portions 4.4 of the left and right side plates 6, 6 are joined together.

The illustrated assembly machine 30 has a trolley 31 that can run on the bottom plate 3 by itself.
A post 32 is erected at the top of the lift arm 33, and a lift arm 33, the base of which is pivotally connected to the post 32, is rotated up and down by the operation of a lift cylinder 34. The inner parts of the left and right side plates 6 are vacuum-sucked by the suction pads 35, and the above-mentioned joining work of the left and right side plates 6.6 to the bottom plate 3 is performed by the operation of the lift cylinder 34.

The assembly machine 30 can run inside the left and right parts 2.2 of the bottom plate 3, and the lift arm 33 supports the inner parts of the left and right side plates 6, 6, so that the assembly machine 30 can travel inside the left and right sides 2.2 of the bottom plate 3, so that the lift arm 33 supports the inside parts of the left and right side plates 6, 6. The necessary working space is sufficient within the arch-shaped area where the left and right side plates 6.6 are joined, and therefore the excavation area of the tunnel 27 can be advantageously reduced.

Next, the PC steel material 15 in the circumferential direction is inserted into the sheath tubes 7 and 11 and the sheath tubes 8 and 12, respectively, and the fixing seats 20 and 2 are inserted.
1, and as shown in FIG.
As shown in the above figure, tension the right PC steel material 15 from the lower end side using the tensioning device 25 applied to the lower end, fix it to the right fixing seat 19 via the fixing plate 16, and fix it to the left fixing seat 19. Although not shown, the PC steel material 15 on the left side pulled out from the seat 18 is tensioned using a tension bag 25 in the same manner as described above, and is fixed to the fixing seat 18 on the left side via the fixing plate 16.

As a result, the bottom plate 3 and the left and right side plates 6.degree. 6 are firmly connected to each other with a large compressive force to form an arch-shaped tunnel unit 26a, and prestress is applied in the circumferential direction along this arch shape to the tunnel unit 26a. It will be introduced in

The prestress introduction work is carried out by pulling out the PC steel materials 15 from the left and right fixing seats 18 and 19 provided at the inner lower part of the left and right portions 2 of the bottom plate 3, so these must be removed before being carried into the tunnel 27. PC steel material 15 is attached to left and right side plates 6
．． Insert the upper end into the upper 4.4° sheath tube 7°8.
If the PC steel members 15 are fixed to the fixing seats 20 and 21, the tensioning operation of these PC steel members 15 can be performed inside the tunnel unit 26a, and they will not protrude outside the tunnel unit 26a. The excavation cross section of the tunnel 27 could be made extremely small.

Tunnel Uni-nod 2 has been installed in this way
PCa materials 15 are inserted in the longitudinal direction into the sheath tubes 9.degree. 10 of every five PCs 6a, and these PC steel materials 15 are tensioned.

The procedure for this tensioning work will be explained by exemplifying the sheath pipe 9 and the fixing seat 22 shown in an enlarged view in FIG. 14.
5 (on the left side of the figure), connect the PC steel material in the longitudinal direction of the unstressed side via the coupler 31 (on the right side of the figure)
As shown in FIG. 12, one tunnel unit 26a without a fixing seat 22, 23 is joined to the outermost side of the five tunnel units 26a, and a short insulator PC steel material 1 is connected.
5 to the PC steel unit on the right side of the figure via the coupler 31, tension these PC steel units 15 using the tensioning device 25 as shown in FIG. When the PC steel material 15 is screwed in and fixed, the extension and addition of the five tunnel units 26a is completed and prestress is introduced in the longitudinal direction.

Once the fixing is completed, the outermost short PC steel T-pieces are removed and the left and right side plates 6.6 are assembled to the bottom plate 3 using the assembly machine 30 as described above, and the tensioning work of the PC steel members 15 in the circumferential direction and the longitudinal direction are performed. By tensioning the PC steel materials 15, for example, five tunnel units 263 are added.

After forming the tunnel 26 of a predetermined length, the sheath tubes 7, 8
Inject grout into ..., grout injection hole 36.37
．． 38 is used to fill the gap between the shaft 27 and the tunnel 26 with grout from inside the tunnel 26.

The joint portion between the left and right portions 2 and the base portion 5 is formed in a stepped shape as shown in the illustrated example, and a packing material 38 is interposed in this joint portion.

The left and right side plates 6.6 mentioned above are formed into an arch shape by joining the upper parts 4.4 of the left and right parts to each other, and FIG. 15 shows a front view, and FIG. 16 shows a front view. As shown in the side view, the present invention is applicable even if the left and right side plates (■) are integrally molded without being divided, and the sheath tube T arranged in the arched direction of the left and right side plates (■) is , it has a simple shape that communicates with the sheath tubes 11.11 of the left and right parts 2.

Although the PC steel material 15 is inserted into the sheath pipe as described above, the present invention can also be achieved by using an unbonded PC steel material as the PC steel material 15 without using a sheath pipe.

After introducing prestress, the fixing seats 17, 18. ... are filled with mortar to smooth out the recesses.

Since the water flow resistance acting in the longitudinal direction of the tunnel 26 is small, the PC steel materials 15 disposed in the longitudinal direction of the bottom plate 3 and the left and right side plates 6 may be made of non-tensioned material or may be made of PCN steel material. When using the material 15, the amount of prestress in the longitudinal direction can be slightly reduced compared to the amount of prestress of the PC steel material 15 in the circumferential direction.

PC steel materials 15 arranged in the left and right direction inside the bottom part 1 of the bottom plate 3
The introduction of prestress may be performed by either a boss tension method or a pretension method.

The PC steel material 15 may also be of an unbonded type. Fixing seat 1B, 19, 22. The number of... can be set in various ways.

(Effects of the Invention) The precast pressure waterway tunnel according to the present invention is configured as described above, in which the base portions 5 of the left and right side plates 6 and the left and right portions 2, 2 of the bottom plate 3 are joined to each other, and By tensioning the PC material 15 disposed along the length, the left and right side plates 6 and the bottom plate 3 are firmly connected to each other with a large compressive force, and at the same time, four prestresses are applied in the arched direction. .

The tensioning operation of the PC steel material 15 in the circumferential direction is performed by using the fixing seat 18.19 provided at the inner lower part of the left and right parts 2.2 of the bottom plate 3, and the PC steel material 15 pulled out from the fixing seat 18.19.
Since this is done by pulling the P
It is possible to perform tensioning work on the C steel material 15.

In this way, a special space for tensioning the PC steel material 15 is not required in the tunnel 27, so according to the present invention,
The excavation cross-sectional area of the tunnel 27 should be any cross-sectional area that is slightly larger than the cross-sectional area necessary to carry in and assemble the left and right side plates 6, 6 and the bottom plate 3, that is, the outer shape of the tunnel unit 26a. , the drilling cost has been reduced considerably.

Fixing seats 22, 23, 24, etc. for the longitudinal prestressing steel material 15 for connecting the left and right side plates 6 to each other in the longitudinal direction to introduce prestress in the longitudinal direction are also attached to the left and right side plates 6 and the bottom plate 3.
The fixing seat 18. of the PC steel material 15 in the circumferential direction is provided on the inner side of the PC steel member 15.
19 are both provided inside the lower part of the bottom plate 3, the prestress introduction work of all these PC steel materials 15 can be
This can be done entirely from inside the tunnel unit 26a, eliminating the need for a special work space required for introducing prestress, which is particularly effective in reducing the cost of excavating the tunnel 27.

[Brief explanation of drawings]

The figures show embodiments of the present invention, and FIGS. 1 and 15 are front views of tunnel units in the respective embodiments, and FIGS. 2 and 3 are left and right views of FIG. 1, respectively. Fig. 4 is a plan view of Fig. 1, Fig. 5 is a perspective view of the tunnel, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 1O, Fig. 11, Fig. 12, Fig. 13. The figure is an explanatory diagram of the tunnel assembly process.
4 is an enlarged sectional view of the main part of FIG. 12, and FIG. 16 is a right side view of FIG. 15. 2... Left and right parts, 3... Bottom plate, 5... Base, 6.6
...Left and right side plates, 15...PC steel material, 18.19.2
2.23゜24...Fixed seat.

Claims (6)

[Claims] (1) Consisting of a pre-shaped bottom plate and arch-shaped left and right side plates whose bases are joined to the left and right parts of this bottom plate, PCs are inserted into the left and right side plates and inside the left and right parts along the arched direction by penetrating the above-mentioned joint parts. In a pressure waterway tunnel in which steel materials are arranged, multiple sets of left and right side plates and bottom plates are connected in the longitudinal direction, prestress is introduced by tensioning the PC steel materials, and the left and right side plates and the bottom plate are connected to each other, A precast pressure waterway tunnel characterized by having PC steel fixing seats located at the inner lower part of the left and right parts. (2) The precast pressure waterway tunnel according to claim 1, wherein the left and right side plates are each divided into two left and right side plates. (3) The precast pressure waterway tunnel according to claim 1, wherein the left and right side plates are formed so that the left and right sides are not divided. (4) Consists of a pre-shaped bottom plate and a number of arch-shaped left and right side plates whose bases are joined to the left and right parts of this bottom plate, and penetrates through the joints and extends inside the left and right side plates along the arched direction. A PC steel material in the circumferential direction is arranged inside the section, and a PC steel material in the longitudinal direction is arranged in the left and right side plates and in the left and right parts of the bottom plate. In a pressure waterway tunnel in which prestress is introduced in the arch direction and longitudinal direction by tensioning the PC steel materials together, and the left and right side plates and the bottom plate are connected to each other, the fixing seat of at least one of the PC steel materials is , a precast pressure waterway tunnel characterized by being installed on the inside of the left and right side plates and the bottom plate. (5) The precast pressure waterway tunnel according to claim 4, wherein the left and right side plates are each divided into left and right side plates. (6) The precast pressure water tunnel according to claim 4, wherein the left and right side plates are formed so that the left and right sides are not divided.