JPH03275900A - Excavation method of shield tunnel - Google Patents

Abstract

PURPOSE:To prevent a non-filled cavity from generating against soil subsidence by placing concrete, while moving mold frames having the same curvature as the inner circumference of tunnel to the circumferential direction of the tunnel, and excavating along the circumferential direction of the tunnel. CONSTITUTION:A part of arc frames 4 is pressed on the inside face of respective tunnel bodies 5a-5e and the arc frames 4 is fixed while being shifted. Next, a gable plate 6 is fitted to the periphery of the arc frame 4 and high-early- strength concrete 7 is charged in the arc frame 4 from a shielding machine. Next, after the concrete 7 is cured, the arc frame 4 is removed off and transferred to the front direction of the next tunnel body 5b. And a shield jack 2 is pressed on the whole face of the cured tunnel body 5 at the periphery except the placed range of the concrete 7 to get a reaction force in order to parallely carry out excavation work of the shielding machine 1 and construction work of the tunnel body 5. In this way, the construction term can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to cast-in-place lining technology, and more particularly to a method for lining a shield tunnel that can be lined in parallel with shield excavation.

<Conventional Technology> A cast-in-place lining method is known as a lining method for the shield method.

This method involves assembling a ring-shaped formwork inside the tail of a shielding machine, and pouring concrete between the formwork and the ground to form the final lining.

In addition, in this type of lining method, when the concrete has developed the required strength, the shielding machine is propelled by using the formwork as a reaction force receiver.

<Problems to be Solved by the Present Invention> The conventional cast-in-place lining technology described above has the following problems.

Because concrete is placed directly in the wide dry area between the formwork and the ground, it is difficult to fill every corner with concrete.

Therefore, an unfilled portion (tail void) of concrete is created between the ground and the lining, causing ground subsidence.

<Examination> Excavation work has to be interrupted each time the formwork is assembled, which tends to lengthen the construction period.

<Objective of the present invention> The present invention was made in order to solve the above problems, and its purpose is to provide a shield tunnel lining method that has excellent workability and can shorten the construction period. It is in.

<Means for Solving the Problems> That is, the present invention provides a shield tunnel lining method in which a tunnel body is constructed by pouring concrete into a formwork assembled in a shield machine. A method for lining a shield tunnel, characterized by using a formwork having a structure, placing concrete while moving the formwork in the circumferential direction of the tunnel, and lining the tunnel along the circumferential direction. It is.

<Description of the present invention> The present invention will be described below with reference to the drawings.

<A> Formwork Figure 1 shows a longitudinal cross-sectional view of the tunnel tip.

Reference numeral 1 denotes a known shield machine, which is equipped with a plurality of sets of shield jacks 2 inside.

The present invention is characterized by the shape of the arcuate formwork 4 assembled within the tail portion 3 of the shield machine 1 and the method of using the arcuate formwork 4.

While the conventional formwork has an annular shape, the arc formwork 4 used in the present invention has a circular arc shape.

Furthermore, whereas in the past the lining is circular, in the present invention the arc-shaped lining is continuous in a spiral shape.

<Exposure> Propulsion reaction force of the shield machine Conventionally, the propulsion reaction force of the shield machine was obtained from the formwork, but in the present invention, the reaction force is obtained from the hardened skeleton of the tunnel 5 except for the area during concrete pouring.

<Effect> Next, the tunnel lining method will be explained.

<A> Assembling the formwork The formwork 4 is assembled within the tail portion 3 of the shielding machine 1 in the same manner as in the conventional method.

When extending the tunnel body 5a as shown in FIG.
, 5e.

At this time, the arcuate formwork 4 is shifted and fixed so that a space for placing concrete can be isolated on the face side of the tunnel body 5a.

An end plate 6 is attached to the peripheral edge of the arc formwork 4.

As a result, a partitioned space for pouring concrete is formed between the tail portion 3 and the arcuate formwork 4.

<Opening> Before pouring concrete, an opening for pouring concrete is opened in the arc formwork 4 or end board 6.

Then, early-strengthening concrete is filled into the arcuate formwork 4 from within the shielding machine 1.

one The concrete 7 hardens and the arcuate formwork 4 is removed from the mold.

The demolded arc formwork 4 is assembled in order to cast concrete in front of the adjacent tunnel frame 5b.

Below, the arc formwork 4 is used as the tunnel frame 5C15d, 5e...
While moving one by one to place concrete in front of the tunnel, the frame of the tunnel 5 is added in a spiral manner.

<C> Excavation with shield machine Traditionally, shield machine was not used to excavate during the concrete curing period.

In the present invention, concrete is not poured over the entire circumference of the tunnel 5, but concrete is poured over a part of the circumference.

Since the circumferential portion excluding the area where concrete is placed is hardened, the shield jack 2 is pressed against the entire surface of this hardened tunnel body to obtain a reaction force.

Therefore, the excavation work of the shield machine 1 and the construction work of the tunnel frame can be performed in parallel.

<Other Examples> In the above example, the case where the lining was performed using one circular arc formwork 4 was explained, but when the tunnel 5 has a large cross section,
Construction may be performed using a plurality of arcuate formworks 4.

Furthermore, the formwork is not limited to an arcuate shape, but may have a shape that corresponds to the cross-sectional shape of the tunnel 5.

In addition, although the above embodiment described the case where the concrete frame is poured in a spiral shape, - one ring is constructed by piecing the arc-shaped tunnel frame in the circumferential direction, and this ring is continuously poured into the tunnel. may be lined.

<Exposure> Concrete placement work and shield machine excavation can be performed in parallel, reducing construction time.

<C> - Compared to the case where the tunnel frame is constructed in a circular manner, only a small number of setups are required.

[Brief explanation of drawings]

Fig. 1.2: A vertical sectional view of the tip of a tunnel for explaining the lining method of the present invention. Fig. 2: A perspective view of the tunnel for explaining the order of adding the tunnel body. <Effects of the present invention> The present invention As explained above, the following effects can be obtained. <B> Since the tunnel framework can be constructed partially, the occurrence of unfilled spaces can be effectively prevented. This effectively prevents ground subsidence.

Claims (1)

[Claims] (1) In a shield tunnel lining method in which a tunnel frame is constructed by pouring concrete into a formwork assembled in a shield machine, a formwork having the same curvature as the inner circumference of the tunnel is used, and the formwork is A shield tunnel lining method characterized by placing concrete while moving in the circumferential direction of the tunnel and lining the tunnel along the circumferential direction.