JPH0788759B2 - Tunnel lining method - Google Patents

Description

The present invention relates to a method of lining tunnels such as shield tunnels and mountain tunnels.

<Conventional technology> There is a new Austrian tunnel method (NATM method) that performs two linings, a primary lining and a secondary lining, when lining the ground immediately after excavation.

The primary lining of this method is a support layer for the purpose of preventing collapse of the ground immediately after excavation, and is generally constructed by spraying concrete.

In addition to the purpose of supporting the secondary lining in cooperation with the primary lining, the secondary lining was constructed for the purpose of maintaining the exterior of the tunnel and stopping water. Generally, it is a place where a mobile formwork device made of steel is used. Constructed of poured concrete.

<Problems to be Solved by the Present Invention> The above-mentioned tunnel lining technique has the following problems.

(A) Since the movable formwork device for the secondary lining occupies most of the work space of the tunnel, it is inconvenient for the work of discharging soil, carrying in various materials into the mine, or passing by workers.

(B) The secondary lining is constructed after the excavation work is completed.

Therefore, it takes a long construction period as a whole.

(C) When constructing the primary and secondary linings, the construction should be done with sufficient design strength, but in reality, if cracks occur in the concrete due to large deformation of the ground, etc. Since there is no member for stopping water, there remains a problem in terms of water stopping.

(D) Maintenance costs are high because the inside of the tunnel is constantly monitored to detect and repair leaks.

(E) When deciding the tunnel excavation diameter, it is theoretically determined by the design winding thickness of the primary lining and secondary lining, but in reality, the lining is affected by the unevenness of the ground. Since there is a difference in the roll-up thickness, the tunnel excavation diameter is set larger accordingly.

However, if the excavation diameter of the tunnel increases even slightly,
The amount of earth and sand excavated will be enormous in proportion to the excavation length, and the time and cost required for excavation will increase.

<Object of the present invention> The present invention has been made in view of the above points, and an object thereof is to provide a tunnel covering method as follows.

(B) A tunnel lining method in which the secondary lining is thin and has excellent waterproofness.

(B) A tunnel lining method that can significantly reduce the construction period.

(C) Tunnel lining method with high quality and easy quality control.

(D) A tunnel lining method that can reduce the tunnel excavation diameter.

<Structure of the Present Invention> An embodiment of the present invention will be described below with reference to the drawings.

In this embodiment, the case of a shield tunnel will be described.

<B> Tunnel Cross Section Structure FIGS. 1 and 2 show the cross section of the tunnel according to the present invention.

Reference numeral 1 is a segment as a primary lining material, 2 is a prefabricated plate as a secondary lining material, and 3 is a water blocking material interposed between the segment 1 and the prefabricated plate 2.

The conventional secondary lining was a thick-rolled concrete body, but in the present invention, a prefabricated plate 2 of the field assembly type and thin is used as the secondary lining.

Further, the water blocking material 3 is interposed between the segment 1 and the prefabricated plate 2 to improve the water blocking performance of the tunnel.

<B> Prefabricated plate (Fig. 3) The prefabricated plate 2 is a curved dividing plate that functions as a finishing material as a secondary lining and also as a form material when the water blocking material 3 is interposed. Made of thin, lightweight, high-strength material.

This prefab plate 2 is a PIC board or P that can be manufactured in high quality at the factory.
A precast plate such as C plate can be used.

An injection hole 21 and a mounting hole 22 are formed in the plate surface of the prefabricated plate 2.

Next, a tunnel construction method will be described. (First to third
Figure) <1> Excavation The shield machine 4 is suspended in the starting shaft A to start excavation.

<2> Primary lining In parallel with the excavation work, segment 1 will be loaded into the mine and assembled, and the ground immediately after excavation will be lined up sequentially.

The segment 1 is hoisted by an erector device installed in the shield machine 4, and each segment 1 is bolted to assemble.

In addition, the backfill material 8 is filled in the space generated between the segment 1 and the ground 7 in a known manner.

Next, a sleeper 5 made of PC concrete is horizontally arranged on the bottom of the segment 1 and sequentially fixed.

A rail 51 is attached to the upper surface of the sleeper 5 to form a passageway for various vehicles.

A PC board 52 is laid between the sleepers 5 in the tunnel direction.

<3> Secondary lining Secondary lining is performed in parallel with tunnel excavation work and primary lining work.

In this secondary lining work, the prefabricated plate 2 produced in the factory is transported to the mine and bolted inside the segment 1 for assembly.

That is, the connection between the circumferential directions of the prefabricated plates 2 is the fourth.
As shown in the figure, the seal member 6 is interposed and the connecting bolt 23 and the nut 24 are fastened together to assemble in an annular shape.

In FIG. 4, reference numeral 25 is a stud for fixing the flange 26 to the end face of the prefabricated plate 2.

Further, as shown in FIG. 5, the connection between the prefabricated plates 2 in the direction of the tunnel axis is made between the flange 27 having a crank-shaped cross section attached to one side of the prefabricated plate 2 and the side surface of the other prefabricated plate 2. Connection is made with a sealant 61 interposed.

Further, a fixing bolt 28 is passed through the mounting hole 22 of the prefabricated plate 2, and the tip of the fixing bolt 28 is screwed and fixed to an embedded nut 11 recessed in the plate of the segment 1. (FIG. 6) At this time, the prefabricated plate 2 is not brought into close contact with the inner circumference of the segment 1, but is assembled while ensuring a continuous gap with the inner circumference of the segment 1.

When assembling the prefabricated plate 2, the inner diameter of the prefabricated plate 2 is assembled according to the finished inner diameter.

<4> Injecting the waterproof material After the prefabricated plate 2 is assembled into a ring with a constant span, connect a hose for injecting the waterproof material to the injection hole 21 of the prefabricated plate 2, and connect the peripheral surface between the segment 1 and the prefabricated plate 2. Inject the water blocking material 3 into the.

As the water blocking material 3, for example, high tyvex mortar,
Tascon mortar etc. can be used.

The water blocking material 3 is poured until it reaches the entire area of the gap between the segment 1 and the prefabricated plate 2.

The above-mentioned excavation work, primary lining work, secondary lining work, and work of injecting the water blocking material 3 are carried out in parallel while completing a tunnel of a predetermined length.

<Other Examples> In the above examples, the case where the secondary lining is performed in parallel with the excavation work and the primary lining has been described, but it is also possible to collectively perform the secondary lining after the excavation work. .

In this case, the prefabricated plate 2 can be assembled at any position, and the efficiency of assembling the secondary lining plate is improved.

It can also be used as a lining for mountain tunnels without segments and as a secondary lining for propulsion pipes.

<Effects of the Present Invention> Since the present invention is as described above, the following effects can be obtained.

(A) Water-stopping material is continuously interposed between the peripheral surfaces of the primary and secondary linings, and a sealing material is also interposed between the prefabricated plate connecting surfaces of the secondary linings Was applied.

Therefore, even with a secondary lining having a thin roll thickness, a high water-stopping effect can be obtained, and the maintenance cost can be reduced.

(B) Comparing the tunnel excavation diameter of the prior art in which the secondary lining is made with concrete with a high roll-up pressure and the tunnel excavation diameter of the present invention, in the present invention, a thin wall and a prefabricated plate are used as the secondary lining material. Therefore, the tunnel excavation diameter can be reduced compared to the conventional one.

Therefore, the amount of excavated earth and sand is reduced, and it is possible to excavate economically.

(C) The excavation work, the primary lining work, the secondary lining work, and the injection work of the waterproofing material can be performed in parallel.

In addition, the conventional curing period for the secondary lining is unnecessary.

Therefore, the whole construction period can be remarkably shortened and the construction cost can be saved.

(D) For the secondary lining, workers carry the lightweight prefabricated plates and assemble them on site.

Therefore, a large machine for performing the secondary lining work is unnecessary, and the work space in the tunnel can be effectively used for, for example, soil discharging work, loading work of the primary lining material, and passage of workers.

(E) For the prefabricated plate that is the secondary lining material, use the one produced with high quality at the factory.

Therefore, the quality control of the secondary lining is easy.

(F) In the prior art, there is a method of forming a water blocking layer using a thin sheet material such as rubber, plastic, or a synthetic resin film. However, in such a method, the strength of the water blocking layer is small,
Furthermore, there is a limit to the waterproofness.

On the other hand, the present invention uses the secondary lining as a formwork,
Since it is a method of forming a water blocking layer by filling a water blocking material between the peripheral surfaces of the primary lining and the secondary lining, it is possible to form a thick wall-shaped water blocking layer and to achieve high water blocking performance. Greater strength of the water blocking layer can be obtained.

[Brief description of drawings]

FIG. 1: Illustration of tunnel lining method according to the present invention FIG. 2: Sectional view taken along line II-II of FIG. 1 FIG. 3: Illustration of prefabricated plate during assembly FIGS. 4 and 5: Prefabricated plate Illustration of the connection method of Fig. 6: Illustration of the fixing method for fixing the prefab plate to the segment

Claims (1)

[Claims] 1. A primary lining is constructed on the ground immediately after the excavation work in parallel with the excavation work, and a secondary division is constructed by assembling a ready-made divided body inside the primary lining in parallel with the excavation work. Then, a continuous gap is secured between the peripheral surfaces of the primary lining and the secondary lining, and a waterproof material is injected into the continuous space to form a waterproof layer between the primary lining and the secondary lining. Tunnel lining method characterized by forming and performing