JPH0430097A - Shield excavator for cast-in-place concrete lining - Google Patents

Abstract

PURPOSE:To allow to pass even a small radius of curve easily by assembling an inner mould and an outer mould at the inner side of a tail plate, and providing a movable spacer between the inner side of the tail plate and the outer mould. CONSTITUTION:At the inner side of a tail plate 11 at the rear side of a shield excavator 1, an inner mould 2 and an outer mould 3 are assembled. Then, between the inner side of the tail plate 11 and the outer mould 3, a movable spacer 4 is provided. And sufficient tail clearances are left between the tail plate 11 and the outer mould 3, and between the outer mould 3 and the natural ground. As a result, a sufficient space can be maintained around the tail plate 11 even when the excavator passes a curve, and it can pass the curve easily.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a shield excavator for performing cast-in-place concrete lining.

<Prior Art> A cast-in-place concrete lining method has been developed in which lining is performed by directly placing concrete within the tail plate at the rear of a shield excavator.

Compared to the method of assembling segments, this construction method has the characteristic that there are no joints, so there are no structural weaknesses.

<Problems to be Solved by the Present Invention> However, this conventional construction method has the following problems, particularly in construction on curved sections or in areas with a lot of groundwater.

<A> In the conventional construction method, concrete is filled between the outside of the inner formwork, the tail plate, and the ground, and the concrete is pressurized with a press jack.

Therefore, no voids are created between the tail plate and the inner formwork, which are all filled with concrete.

However, when a shield tunneling machine passes through a curved section, the rear part of the machine naturally moves in a curved line, but requires space.

For this reason, the conventional method, which lacks free space inside the fuselage, has found it extremely difficult to pass curves, especially curves with small radii.

<Exposure> In order to deal with the problem of passing through curves, if we do not completely fill the concrete with mochi and create a gap between the ground mass and the inner formwork, then the problem of groundwater inflow will occur. .

In other words, in the current construction method, the water-stopping effect is achieved through the internal pressure of filling and pressing concrete into the tail plate, so creating a void in this area would prevent groundwater from flowing into the fuselage. I can't.

<Objective of the present invention> The present invention has been made in order to improve such problems, and an object of the present invention is to provide a shield tunneling machine as described below. (- Kui) A shield tunneling machine that can easily pass through curves with a small radius. The present invention has an inner formwork and an outer formwork assembled inside a rear tail plate of a shield tunneling machine, and a movable spacer is positioned between the inside of the tail plate and the outer formwork. , a shield excavator for cast-in-place concrete lining.

<Description of the present invention> The present invention will be explained in detail below.

<A> Inside the tail plate 11 at the rear of the formwork shield excavator 1,
Assemble the inner formwork 2.

The shield tunneling machine 1 is equipped with a propulsion jack 13,
By pressing this propulsion jack 13 against the inner formwork 2 and extending it, the shield excavator 1 is moved forward.

At the same time, the shield excavator 1 is provided with a press jack 12 for compressing concrete, and the concrete is compressed by expanding the press jack 12.

The above structure is the same as that of the conventional device, but the present invention is to assemble the inner formwork 2 inside the tail plate 11 at the rear of the shield tunneling machine l, and at the same time assemble the outer formwork 3 on the outside thereof. This is one of its characteristics.

The outer formwork 3 is an annular body, and is constructed by assembling a plurality of circular arc plates with bolts. The bolts are arranged so that they do not protrude outside the outer formwork 3.

Then, an arcuate plate is assembled with bolts outside the inner formwork 2 to form an outer formwork 3, and concrete is poured between the inner surface of the outer formwork 3 and the outer surface of the inner formwork 2 with a pump.

The outer formwork 3 is arranged in the same manner as the conventional existing segments so that the joint lines of the arcuate plates are arranged in a staggered manner.

<Mouth> Spacer A spacer 4 is arranged between the outer peripheral surface of the outer formwork 3 and the tail plate 11.

This spacer 4 is a narrow ring, and is also constructed by assembling a plurality of arcuate bands.

The spacer 4 made of this circular arc band is not fixed to the outside of the outer formwork 3, but is fixed to the tip of a third jack, that is, a spacer jack 41 provided on the main body side of the shield excavator 1.

Therefore, as the spacer jack 41 expands and contracts, the spacer 4 is positioned in contact with the outer peripheral surface of the outer formwork 3,
It comes off from the outer formwork 3 and is stored in the tail plate 11.

<C> Tail seal A tail seal 14 is fixed to the terminal end of the tail plate 11 over the entire circumference.

This tail seal 14 is a member made of an elastic member such as rubber or a wire brush, and is arranged at a position surrounding the outer formwork 3 from the outside.

<Operation> Next, the operation will be explained.

<A> Assembling the formwork Install the outer formwork 3 inside the tail plate 11 of the shield excavator l.
and inner formwork 2 are assembled.

Concrete is then poured from the opening of the inner formwork 2 into the space between the two formworks using a pump.

The end face of the poured concrete is closed by a press ring at the tip of the press jack 12.

This closing position, that is, the joint position of one concrete, is arranged so as not to overlap the joint position of the inner and outer formwork.

<Mouth> Construction of the gap In order to form a gap S between the outer surface of the outer formwork 3 and the inner surface of the tail plate 11, a spacer 4 is inserted between the two.

The spacer 4 is inserted by a spacer jack 41.

By inserting the spacer 4, even if the outer formwork 3 is made of a thin steel plate or a thin precast plate, it can resist the force from the inner mold that acts when the concrete is compressed.

When the spacer jack 41 is shortened and the spacer 4 is pulled out after the concrete has hardened, a gap S is generated between the two.

Due to the existence of this gap S, the shield excavator 1
Sufficient margin can be provided when the main body passes through a curve.

<C> Filling of external voids A void exists between the outer formwork 3 and the ground.

Therefore, it is not possible to block the inflow of groundwater with concrete, unlike the conventional filling method that does not use external formwork.

However, at the end of the tail plate 11 there is a tail seal 14.
Since this is provided, it is possible to sufficiently prevent groundwater from flowing into the shield excavator 1.

After pouring the concrete, the space between the ground and the outer formwork 3 is filled with mortar.

Even at this time, the tail seal 14 can prevent mortar from flowing into the body.

The gap S between the outer formwork 3 and the inner surface of the tail plate 11 is also filled with mortar by injecting it after the shield excavator 1 moves.

<2> Other Examples In the above structure, the spacer is made of an integral arc-shaped steel material, but it can also be divided into pieces as shown in FIG.

That is, a grooved ring 42 is attached to the tip of the spacer jack 41, and the grooved ring 42 is slid toward the outer formwork 3 with the groove 43 open.

On the other hand, a narrow circular arc band 44 is attached to the outer periphery of the outer formwork 3, and this group of circular arc bands 44 is configured to be able to be stored in the groove 43.

With this structure, concrete can be poured by assembling the outer formwork 3 with the arcuate band 44 attached to the outer periphery inside the grooved ring 42.

Once the concrete has hardened to some extent, the grooved ring 42
When pulled back toward the body, the arcuate band 44 fits into the groove 43 and is pulled back.

<Effects of the Present Invention> Since the present invention has the above-described configuration, the following effects can be achieved.

<B> Sufficient gaps (tail clearance) can be left between the tail plate and the outer formwork, and between the outer formwork and the ground.

Therefore, extra space is secured around the tail plate when passing through a curve, and it is easy to pass through a curve with a small radius.

Needless to say, when passing through a curve, tapered formwork is used for both the inner and outer formwork.

<Mouth> The flow of groundwater and mortar into the interior of the fuselage from the space between the outer formwork and the ground can be prevented by the tail seal.

Therefore, construction similar to segment lining can be performed.

<C> In the conventional method of using the ground as the outer formwork,
The next process could not begin until the concrete hardened and developed a certain level of strength.

If the apparatus of the present invention is used, the concrete is surrounded by formwork inside and out, so the next step can be started immediately without waiting for the concrete to develop its strength, and continuous construction is possible.

(2) Since it is made of concrete surrounded by formwork inside and outside,
Compared to the conventional method of using the ground as the outer formwork, the quality is better (and the thickness of the poured material can be kept constant).

[Brief explanation of drawings]

Fig. 1 2 An explanatory diagram of the overall structure of an embodiment of the device of the present invention Figure 2: Explanatory diagram of main parts

Claims (1)

[Claims] (1) It has an inner formwork and an outer formwork assembled inside the rear tail plate of the shield tunneling machine, and a movable spacer is positioned between the inside of the tail plate and the outer formwork. Shield excavator for cast-in-place concrete lining