JPH05118194A - Sealing method of lining in cast-in-place lining shield method - Google Patents

Abstract

PURPOSE:To make improvements in operational safety and workability by securing the extent of water stoppability between a skine plate and a concrete lining after removal of press pressure, in a cast-in-place lining shield method. CONSTITUTION:At the time of setting up a form 4, a wire net 20 is set up in the inner circumferential surface of a skin plate 2 at a driving tip position of concrete C. When the concrete C is pressed according to a forward motion of the skin plate 2, the wire net 20 is relatively moved backward together with the concrete C in relation to the skin plate 2. When the press pressure is opened free, the concrete C is kept in the wire net 20 at a connecting part between a rear end inner circumferential surface of the skin plate 2 and concrete C'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing method for preventing water leakage from a joint between a skin plate and a concrete lining in a cast-in-place lining shield method.

[0002]

2. Description of the Related Art A cast-in-place lining shield method is a method in which, at the same time as a shield machine is excavated, it is provided between an inner peripheral surface of a skin plate forming an outer shell of the shield machine and a formwork arranged inside the skin plate. This is a construction method in which the lining is formed by high-pressure pressing the placed concrete. It does not require a backfilling injection process compared to conventional construction methods, there is no collapse of the tail void portion, and high strength is achieved by high-pressure pressing. Thus, a uniform lining structure can be obtained.

In this construction method, the forward movement of the shield machine and the high-pressure pressing of concrete are performed by the jack provided on the inner peripheral portion of the skin plate, and the thrust is received by the press ring provided at the tip of the concrete placing surface. ing.

Therefore, the skin plate advances due to the reaction force of the jack and the placed concrete is compressed through the press ring. After that, the jack is reduced to remove the press pressure, and The formwork and press ring are set back to the front, and the concrete pouring and advance / high pressure press work of the shield machine are repeated.

[0005]

However, when the advance / high pressure press work of the shield machine for one step is completed,
The concrete that has been cast in the state where the pressing pressure is removed, that is, the length at which the outer periphery of the concrete lining and the inner peripheral surface of the skin plate are joined is shortened as the skin plate advances, and the pressing force is reduced. Since it has been removed, a slight gap is likely to occur at the joint between the skin plate and the concrete lining. If the ground is permeable and the groundwater level is high, groundwater may flow through the gap into the shield mine, causing unexpected accidents and work stagnation.

The present invention has been made in view of the above problems, and it is possible to easily secure the waterproof property between the skin plate and the concrete lining after removing the press pressure, and An object of the present invention is to provide a lining sealing method capable of improving safety and workability in performing assembly work and the like.

[0007]

In order to achieve the above-mentioned object, a sealing method of a lining in a cast-in-place lining shield method of the present invention is a method of forming a skin plate and a mold of the shield machine at the same time when the shield machine is excavated. In a cast-in-place lining shield construction method in which high-pressure press is applied to the concrete placed in between, a sealing method of the lining for preventing intrusion of groundwater between the skin plate and the concrete, the formwork At the time when the concrete is placed, a wire mesh is placed on the inner peripheral portion of the skin plate at the pouring tip position of the concrete, and when the concrete is pressed according to the forward movement of the skin plate, the wire mesh is skinned with the skin plate. It moves backward relative to the skin pre-press when the press pressure is released. At the junction of the rear end inner peripheral surface of the bets and the concrete, it is characterized in that holding the concrete to the metal wire net.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 (a), 1 (b) and 1 (c) are sectional views showing the construction sequence of the cast-in-place lining shield construction method to which the present invention is applied.

In the figure, a shield machine 1 is provided with a plurality of jacks 3 extending rearward on an inner peripheral portion of a cylindrical skin plate 2.

Also, on the inner periphery of the rear part of the skin plate 2,
A mold 4 having a length corresponding to the stroke length of the jack 3 is assembled in a tubular shape, and a press ring 5 is located between the skin plate 2 and the mold 4 so as to face the jack 3. ..

In this cast-in-place lining method, concrete C is poured through the concrete casting pipe 6 between the most advanced formwork 4 and the skin plate 2 as shown in FIG.

After placing the concrete C, the shield excavator 1 excavates the cutting face, and excavates the excavated earth and sand through the conveyors 8 and 9 provided in the shield excavator 1 and the existing shield pit 7 behind it. When the jack 3 is extended, the shield machine 1 advances by the stroke of the jack 3 due to the reaction force of the jack 3, as shown in FIG.

At the same time, the concrete C is high-pressure pressed by the jack 3 via the press ring 5 to fill the tail void on the rear side of the skin plate 2 and form a high-strength and uniform concrete lining C '.

Next, as shown in FIG. 3C, the jack 3 is reduced and the concrete lining C'formed by casting is formed.
By arranging the reinforcing bar 10 on the inner periphery of the skin plate 2 between the jack 3 and the jack 3, assembling a new form 4 inside thereof and installing the press ring 5 on the front surface,
Preparation for placing concrete C for lining in the next step is completed.

By repeating the steps (a) to (c) in the figure, the shield excavation is sequentially performed.

Here, when the jack 3 shown in FIG. 1 (b) is fully extended, it is assumed that the joint length between the cast concrete C, that is, the concrete lining C'and the skin plate 2 is extremely short. Therefore, the space between them is sealed by the following method.

That is, in the assembly process of FIG. 1 (c), as shown in FIGS. 2 (a) and 3, in the vicinity of the press ring 5, which is the position of the concrete pouring tip, inside the skin plate 2. The strip-shaped wire net 20 is arranged on the entire circumference or at least on the ceiling side.

Next, when the shield machine 1 is moved forward and the concrete C is pressed under high pressure, the wire mesh 2
0 is due to the pressing force of the press ring 5 and the skin plate 2
While sliding on the inner circumference of the skin plate 2, it moves backward relative to the skin plate 2 together with the concrete C, and is located at the inner circumference of the rear end of the skin plate 2 as shown in FIG. 2 (b).

Part of the concrete placed by this pressing force and relative sliding is rubbed in the wire net 20,
It is held crosslinked in the eye.

Therefore, from the rear end of the skin plate 2, groundwater tries to enter the inside of the skin plate 2 along the joint between the inner circumferential surface of the skin plate 2 and the concrete C, that is, the concrete lining C '. However, the intrusion is surely prevented by the wire net 20 and the concrete clogged in the eyes.

FIG. 4 shows another embodiment of the present invention.

In the figure, the tip of the wire net 20 is folded back at the tip of the concrete lining C'and is arranged both over the outer periphery of the form 4 and the inner periphery of the skin plate 2.

In this embodiment, the same effect as the above embodiment can be obtained. Further, there is no displacement of the wire net 20 during relative movement. Furthermore, reinforcement of the concrete connecting surface is done by this wire mesh 2.
It can be performed by 0.

[0025]

As described above in detail with reference to the embodiments, according to the present invention, after removing the press pressure, the form,
It is possible to surely secure the waterproofness when performing the press ring assembling work, etc. Therefore, it is possible to easily improve the safety and workability of these works. Further, since the wire mesh is simply arranged in the assembling process, there is no need for a double-sided work, and the outer peripheral portion of the concrete lining can be reinforced by the wire mesh.

[Brief description of drawings]

1 (a), (b) and (c) are cross-sectional views showing a construction sequence of a cast-in-place lining shield method to which the present invention is applied.

2 (a) and 2 (b) are partial cross-sectional views showing a main part of the seal structure of the present invention, (a) showing a state before pressing concrete, and (b) showing a state after pressing concrete. Respectively.

FIG. 3 is an enlarged view of part A in FIG.

FIG. 4 is a cross-sectional view of essential parts showing another embodiment of the present invention.

[Explanation of symbols]

 1 Shield machine 2 Skin plate 3 Jack 4 Form 5 Press ring 20 Wire mesh C Concrete C'Concrete lining

Claims (1)

[Claims] 1. A cast-in-place lining shield construction method in which concrete placed between a skin plate and a formwork of the shield machine is pressed at the same time when the shield machine is excavated, in the cast-in-place lining shield method. A method of sealing a lining to prevent intrusion of groundwater from between, by disposing a wire mesh at the inner peripheral portion of the skin plate at the pouring tip position of the concrete when the formwork is installed, When the concrete is pressed according to the forward movement of the skin plate, the wire mesh moves backward together with the concrete relative to the skin plate, and when the pressing pressure is released, the inner peripheral surface of the rear end of the skin plate and the concrete A cast-in-place caster characterized by holding concrete in the wire mesh at the joint with Lining sealing method in the inning shield method.