JPS6335909A - Precast pressure-resistant waterway tunnel - Google Patents

Abstract

PURPOSE:To quickly construct a pressure resistant waterway tunnel having excellent stiffness by a method in which a bottom plate and a pair of side plates are molded and connected to form an arched tunnel unit, and the arched tunnel units are carried in a tunnel and set. CONSTITUTION:An arch form of left and right-handed side plates 6 and a bottom plate 3 are formed in a factory and assembled temporarily. PC steel materials are inserted into sheath tubes 7, 8, and 14 for blocks and fixed by the upper fixing seats 20 and 21 of the side plates 6 and the fixing seat 17 of the plate 3 to combine the blocks. The units so formed are orderly carried in a tunnel and set, and the PC steels are inserted even into the longitudinal direction to connect the units. A pressure waterway tunnel having excellent stiffness can thus be quickly constructed.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a precast pressure water tunnel used as a headrace in hydroelectric power generation, for example, and is prestressed, has a thin wall thickness, is small in size, This project proposes a pressure tunnel that is lightweight, made of factory-precast material, low cost, stable quality, and convenient to handle.

(Prior art) Conventional pressure tunnels are built using a cast-in-place method by incorporating formwork into a tunnel in the ground, and cracks are likely to occur on the wall surface due to earth pressure and internal water pressure. This causes water leakage.

In order to prevent such cracks, pre-stressing has been introduced, but since it is cast in place, the walls tend to be thicker and the cross-sectional area of the tunnel excavated is large.
Moreover, the cross-sectional area of the excavation becomes much larger due to the working space required for assembling the formwork, and since it is located inside a tunnel, there are problems such as a long curing period being required.

(Problems to be Solved by the Invention) This invention solves the problem that it is difficult to reduce the wall thickness for on-site casting, and the cross-sectional area of the excavation of the tunnel is difficult. This solves the above-mentioned conventional problems, such as requiring long curing times, and allows the wall thickness to be thin, reducing the cross-sectional area of the tunnel excavation, eliminating the occurrence of cracks, and creating a lightweight, low-cost, low-friction pressure system. It proposes a tunnel.

(Means for solving the problem) In order to solve the above problem, the present invention takes the following technical means.

That is, a pre-shaped bottom plate 3 and a large number of left and right side plates 6, 6.
The bases 5 of the left and right side plates 6 are joined to the left and right parts 2 of the bottom plate 3, and the upper parts 4 of the left and right side plates 6 are joined to each other to form an arch shape. 4
A PCW4 material 15 is disposed inside the left and right side plates 6, 6 and within the left and right parts 2°2 along the arched direction, penetrating the joint part of the left and right parts 2 and the joint part of at least one of the left and right parts 2.
By applying tension, a prestress is introduced, and the left and right side plates 6, 6 and the bottom plate 3 are connected to each other, and multiple sets of the bottom plate 3 and left and right side plates 6, 6 are joined in the longitudinal direction to form the tunnel 26. This is a precast pressure waterway tunnel.

(Function) The respective base parts 5 of the left and right side plates 6 are joined to the left and right parts 2 of the bottom plate 3, the respective upper parts 4 of the left and right side plates 6 are now brought into contact with each other, and the joint part of the upper part 4 and at least one of the left and right parts 2 are connected. Penetrate the joint part and follow the gate shape into the left and right side plates 6, 6 and the left and right parts 2, 2.
By tensioning the PC steel material 15 disposed inside, the left and right side plates 6
, 6 and the bottom plate 3 are coupled together with a sufficiently large compressive force to form an arch-shaped tunnel unit 26a, and the prestress applied to this arch-shaped tunnel unit 26a is introduced into the tunnel unit 26a. It becomes.

This tunnel unit 26a is made up of three precast members: the left and right side plates 6, 6 and the bottom plate 3, so it is small and lightweight, making it easy to handle.Moreover, since it is made of precast material, the quality is always excellent. The tunnel 26 is stable and efficiently manufactured, resulting in a low-cost tunnel 26.

(Example) Next, one embodiment of the present invention will be described with reference to 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 By joining the bottom plate 3 standing up from the base plate 3 and its upper parts 4, 4 to each other, it forms 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 that are
It is molded using the precast method.

The bottom plate 3 and the left and right side plates 6, 6 are both shaped to have short lengths for ease of handling such as transportation.

As is clear from the perspective view shown in FIG.
Sheath tubes 7, 7 and 8, 8 that penetrate along the arch shape
One of the sheathed tubes 7, 7 is arranged near the longitudinal center of the left and right side plates 6, and the other sheathed tubes 8, 8 are arranged on the outside in the longitudinal direction, respectively. There is a sheath tube 9 nearby, a sheath tube 10 at the base 5, and both left and right side plates 6.
It penetrates clearly in the longitudinal direction.

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 PC steel material 15 is provided on the outside of the corner of the bottom l, for example, a concave fixing seat 17.17.
18. Fixing plates 20 and 21.18 and 19, respectively, are fixed, and also on the outside of the upper parts 4, 4 of the left and right side plates 6, for example, concave fixing plates 20 and 21.
21 are respectively provided, concave fixing seats 22 and 23 are provided on the inner side of one of the left and right side plates 6, and a concave fixing seat 24 is provided on one of the bottom plate 3. are provided inside the left and right parts 2.

The left and right side plates 6, 6 precast in this way
and the bottom plate 3, as illustrated in FIGS. 7 and 8, the upper part 4
. The upper end of the steel material is fixed, and the sheath pipe 8 and the sheath pipe 12 are fixed with P in the circumferential direction.
The upper ends of these PC steel materials 15 are fixed to the fixing plate 16 of the fixing seat 21 by inserting the C steel materials 15 respectively, and each of these PC steel materials 15 is tensioned from the side of the bottom part 1 using the tensioning device 25. If the four PC steel members 15 in the circumferential direction are fixed to the fixing plates 16 of fixing seats 18 and 19 of No. 3, the left and right side plates 6, 6
are joined to each other at the upper parts 4, 4, and the left and right side plates 6, 6 and the bottom plate 3
are joined to each other at the base 5 and the left and right parts 2 to form one arch-shaped tunnel unit 26a, and the Teflon stress is applied along this arch shape to the tunnel unit 26a.
There will be 4 K people.

By inserting the PC steel material 15 into the sheath pipe 14,
5 is tensed to introduce prestress in the left-right direction of the bottom plate 3, and grout is injected into the sheath pipes 7, 8, and 14.

A tunnel 27 is excavated in the ground, and five tunnel units 26a, for example, are temporarily tightened using the PC steel material 15 inserted through the sheath pipes 9 and 10.13, and the five integrated tunnel units 26a are assembled as shown in FIG. The tunnel units 26a are then carried into the tunnel 27 using a glossy cart 28, and each tunnel unit 26a is installed at a predetermined position using a forklift 29 as shown in FIG. 10. Insert the PC steel material 15 in the longitudinal direction into the sheath tubes 9', 10, and 13 every five pieces, and insert the PC steel material 15 into the fixing plate 16.
Fix the front end of the

Next, the five tunnel units 26a are temporarily tightened again, and the five tunnel units 26a are carried into the tunnel 27 using the glossy cart 28, and the forklift 29 is used to move the tunnel units 26a one by one. , installed in a predetermined position, the sheath pipes 9, 1 of the five tunnel units 26a
0.13 by inserting the longitudinal PC steel material 15 into the 13th
As illustrated for the sheath tube 9 and fixing seat 22 in the figure,
The prestressed longitudinal prestressing steel material 15 (on the left side of the figure) is attached to the threaded portion 15a of the prestressed longitudinal prestressing steel material 15 (on the left side of the figure) which has already been installed and fixed, via the coupler 30 (on the right side of the same figure).
As shown in Fig. 11, one tunnel unit 26a without a fixing seat 22 or 23 is joined to the outermost side of the five tunnels 22) 26a, and a short PC steel material is connected to the same one. It is connected to the PC steel material 15 on the right side of the figure via the coupler 30, and the tension device 25 is used to tighten the PC steel material 15 on the right side of the figure.
When the opening is tightened and the anchor nut 31 is screwed into the threaded portion 15a to fix the PC steel material 15, 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 material 15 is extracted, and the five tunnel units 26a are carried in the above-mentioned order into the tunnel 27 using a cart with jacks 28, installed using a forklift 29, and transported. A tension force is applied to the five tunnel units 261L that have been added and one tunnel unit 261L, and the new five tunnel units 26a are combined, and in this way, for example, five tunnel units 26a are added. Become.

After forming the tunnel 26 of a predetermined length, the sheath tube 9,
10. Inject grout into the holes 32 and 33 of the bottom plate 3 and left and right side plates 6, respectively, as shown in FIG.
．． 34 is used to fill the gap between the shaft 27 and the tunnel 26 with grout from inside the tunnel 26.

The tunnel unit 26a can be carried into the shaft 27 and installed by various methods in addition to the above-mentioned example.

In the above embodiment, the PC steel material 15 is attached to each sheath pipe 7,
8. ... was used, and the sheath W
The present invention can be achieved even if the unpond PC steel material 15 is used without using 7, 8, . . . .

That is, an unsold PC steel material is disposed along the arch shape in the left and right side plates 6, and an unpounded PC steel material is disposed in the left and right parts 2 in the circumferential direction. When the and bottom plate 3 are joined, both of the unbonded steel members are connected to each other in, for example, connecting recesses (not shown) provided in the left and right parts 2, and the upper parts of the left and right side plates 6 and the left and right parts of the bottom plate 3 are connected together. Regarding the unbonded PC steel materials that penetrate through the bottom part 2 in the front and rear directions, the adjacent ones in the front and rear are connected, and the unbonded PC steel materials are arranged in the left and right direction inside the bottom part 1.

Since the force acting in the longitudinal direction of the tunnel 26 during water flow is small due to water flow resistance, it is also possible to introduce a prestress amount in the longitudinal direction that is slightly reduced compared to the circumferential direction.

The PC steel materials 15 disposed in the left-right direction within the bottom portion 1 may be of either the post-tension type or the pre-tension type as described above.

In the illustrated example, the fixing recesses 22, 23 and 24 for the prestressed steel material 15 in the longitudinal direction of the tunnel 26 are provided inside both the left and right side plates 6 and the bottom plate 3, so that the fixing recesses 22, 23 and 24 for the prestressed steel material 15 in the longitudinal direction of the tunnel 26 are provided inside both the left and right side plates 6 and the bottom plate 3. Since the fixing operation for screwing in the anchor nut 31 can be performed from inside the tunnel 26, the cross-sectional area of the tunnel 27 can be set to the smallest size that can carry the tunnel unit 26a, and the excavation cost can be reduced sufficiently. It can be done cheaply.

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 35 is interposed in this joint portion.

Further, each of the fixing seats 17, 18, . . . is filled with mortar to smooth the recessed portions.

In the illustrated example, the circumferential PC steel material 15 inserted through the sheath pipe 7 of the upper part 4 of one of the left and right side plates 6, 6 and the sheath pipe 7 of the other left and right side plate 6 is inserted into the left and right parts 2 of the other side of the bottom plate 3. death,
This P whose upper end is fixed to the fixing seat 20 on one of the upper parts 4
The C steel material 15 is tensioned from the left and right parts 2 on the other side of the bottom plate 3, and the PC steel material 15 in the circumferential direction is inserted into the sheath pipe 8 of the upper part 4 of the other left and right side plates 6 and the sheath pipe 8 of the other left and right side plates 6. ,
The PC steel material 15, which is inserted through one of the left and right parts 2 of the bottom plate 3 and whose upper end is fixed to the fixing seat 21 of the other upper part 4, is tensioned from one of the left and right parts 2 of the bottom plate 3, so that the circumferential direction of the PC steel material 15 is Due to the tension of the PC steel material 15.15, the left and right side plates 6, 6 are
The respective upper parts 4, 4 are strongly attracted to each other at the joint portion and are firmly connected.

Since the sheath tubes 7, 7 and 8, 8 are arranged symmetrically with respect to the longitudinal center, the prestress introduced by the PC steel material 15 inserted into these sheath tubes 7°8 is:
It acts evenly in the longitudinal direction.

(Effects of the Invention) The precast pressure waterway tunnel according to the present invention is constructed as described above, in which the base portions 5 of the left and right side plates 6 are joined to the left and right portions 2 of the bottom plate 3, and the bases 5 of the left and right side plates 6 are connected to each other. The upper parts 4 of the parts are joined to each other, and the parts are arranged in the left and right side plates 6, 6 and in the left and right parts 2, 2 along an arch shape, passing through the joint part of the upper part 4 and the joint part of at least one of the left and right parts 2. PC to be
, by tensioning the fi material 15, the left and right side plates 6, 6 and the bottom plate 3 are drawn together and joined together with a sufficiently large compressive force, thereby forming the tunnel unino) 26a and creating a prestressed is introduced, and by combining multiple sets of left and right side plates 6, 6 and bottom plate 3 in the longitudinal direction, the above three members are connected to each other and can be used immediately as a pressure waterway tunnel.

Therefore, according to this invention, the curing period required for the cast-in-place construction method is no longer necessary, so the construction period is significantly shortened, and the introduced prestress can effectively counter the tensile stress caused by internal water pressure, which is effective in preventing cracks. Since it is a combination of three members, the left and right side plates 6, 6, and the bottom plate 3, it is effective in reducing the labor involved in handling such as transportation until assembly due to its small size and light weight.

Furthermore, since it is made of precast, the quality is always excellent and stable, and it can be manufactured efficiently, resulting in low cost, making it suitable for pressure waterway tunnels.

In the invention in which the PC steel members 15 are also arranged in the longitudinal direction in the left and right side plates 6 and in the left and right parts 2 of the bottom plate 3, the longitudinal assembly is performed by the tension, and prestress in the longitudinal direction is introduced. Therefore, it has the advantage of enhanced rigidity in the water flow direction.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, and FIG. 1 is a front view of the tunnel unit, and FIGS. 2, 3, and 4 are a left side view, a right side view, and a top view, respectively. FIG. 5 is a perspective view of the tunnel, FIG. 6 is an enlarged sectional view of the main part in FIG. 5, and FIG. 15 is an enlarged sectional view of the main part in FIG. 2...Left and right parts, 3...Bottom plate, 4...Top, 5...
・Base, 6... Left and right side plates, 15... PC steel material, 26
···tunnel.

Claims (6)

[Claims] (1) Consisting of a pre-shaped bottom plate and a plurality of left and right side plates, the bases of the left and right side plates are joined to the left and right parts of the bottom plate, and the upper parts of the left and right side plates are joined to each other to form an arch shape. The PC steel material is provided in the left and right side plates and in the respective left and right parts along the arched direction, penetrating the joint part of the upper part and the joint part of at least one of the left and right parts, and tensions the PC steel material. As a result, prestress is introduced, and the left and right side plates and the bottom plate are connected to each other,
A precast pressure waterway tunnel characterized in that a plurality of sets of the bottom plate and left and right side plates are joined in the longitudinal direction to form a tunnel. (2) The precast pressure water tunnel according to claim 1, wherein the PC steel material is inserted into a sheath pipe. (3) The precast pressure waterway tunnel according to claim 1, wherein the PC steel material is an unbonded PC steel material. (4) Consisting of a pre-shaped bottom plate and a plurality of left and right side plates, the bases of the left and right side plates are joined to the left and right parts of the bottom plate, and the upper parts of the left and right side plates are joined to each other to form an arch shape. A PC steel material is provided in the circumferential direction within the left and right side plates and within the respective left and right parts along the arch-shaped direction, penetrating the joint part of the upper part and the joint part of at least one of the left and right parts, and , PC steel members in the longitudinal direction are arranged in the left and right side plates and in the left and right parts of the bottom plate, and multiple sets of the left and right side plates and the bottom plate are joined in the longitudinal direction, and the PC steel members in the two directions are tensioned together to form an arcuate direction. and a precast pressure waterway tunnel characterized in that a prestress is introduced in the longitudinal direction, and the left and right side plates and the bottom plate are connected to each other to form a tunnel. (5) The precast pressure water tunnel according to claim 4, wherein the PC steel material is inserted into a sheath pipe. (6) The precast pressure waterway tunnel according to claim 4, wherein the PC steel material is an unbonded PC steel material.