JPH0441759B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Application Field>> The present invention relates to a shield excavator for cast-in-place lining, and particularly to a shield excavator capable of performing curved construction.

<<Conventional Technology>> As is well known, the shield method is a method for excavating and constructing underground tunnels such as subway tunnels and undersea tunnels.

The shield method uses a cylindrical shield excavator equipped with a digging bit at the tip, and one type of this method is the cast-in-place lining method, which performs lining at the same time as excavation.

In this cast-in-place lining construction method, a formwork is installed at the rear of the shield excavator, and concrete is poured into the space defined by the formwork, the skin plate of the shield machine, and the preceding lining concrete. The lining is performed by sequentially forming lining concrete inside the tunnel while applying compressive force to the tunnel.

By the way, when performing curved construction using the conventional shield construction method, a folding type shield excavator, which is a cylindrical shield excavator divided into a plurality of parts, is known.

In this type of shield tunneling machine, the cylindrical skin plate is divided into a front and rear body, and, in addition to the propulsion jack, a plurality of folding jacks are provided in the circumferential direction to allow different amounts of expansion and contraction during curved construction.

However, when constructing curved sections using the cast-in-place lining method using such a folding type shield excavator, there are problems described below.

≪Problems to be solved by the invention≫ In other words, when constructing cast-in-place lining with the above-mentioned folding type shield excavator, the reaction force of the propulsion jack is taken up by the formwork or lining concrete, but During construction, this reaction force does not act parallel to the axial directions of the formwork and lining concrete, but rather acts eccentrically, so there is a problem in that a radial component force acts on the lining concrete, causing cracks.

This invention was made in view of these problems, and its purpose is to formwork,
To provide a shield excavator for cast-in-place lining, which applies a reaction force parallel to the axial direction of lining concrete during curved construction.

<<Means for Solving the Problems>> In order to achieve the above object, the present invention includes a front and rear trunk section divided into at least a plurality of parts, a shield jack provided between these trunk sections, and a shield jack provided between the front and rear trunk sections. A shield excavator for cast-in-place lining, which is equipped with a press jack for compressing lining concrete placed by installing a formwork behind the body, the press jack being fixed to the rear body, and The present invention is characterized in that a reaction force transmission jack is fixed to the rear body and transmits the propulsion reaction force of the shield jack to the formwork when the front body is propelled and when the rear body is retracted.

<<Operation>> According to the shield excavator having the above configuration, even if the front body side is eccentric during curve construction, the propulsive reaction force when the shield jack is contracted and the rear body part is drawn into the front body side is Since it is applied to the formwork via a force transmission jack, the press jack that compresses the lining concrete receives almost no propulsion reaction force, and only needs to apply the small pressure necessary for compression, which reduces the influence of eccentricity.

<<Example>> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a shield excavator for cast-in-place lining according to the present invention.

The shield excavator shown in the figure is divided into three stages and has a front body part 10, a middle body part 12, and a rear body part 14 so as to be able to perform curved construction.

A cutter head 16 is rotatably disposed at the tip of the front body 10, and the cutter head 16 excavates the ground on the face side by the rotational driving force of a cutter drive motor 18.

In addition, the front body part 10 on the back side of the cutter head 16
The cutter head 16, front body 10, and partition wall 20 form a compartment 21 for storing excavated soil, and a screw conveyor is provided for discharging the soil in the compartment 21 to the outside. 2
2 is installed with one end penetrating the partition wall 20.

In this embodiment, the screw conveyor 22 is divided into two parts within the middle body 12 in order to cope with curved construction, and the primary screw conveyor 22a and the secondary screw conveyor 22b have a flexible member 24. Each screw conveyor 22a,
22b is rotationally driven by a drive motor 26.

The middle body part 12 is a double cylinder made of an outer cylinder 12a and an inner cylinder 12b that can slide in the axial direction, and a folding jack 28 is provided between the outer cylinder 12a and the front body part 10. A plurality of them are pivotally connected at intervals in the circumferential direction.

Further, a plurality of shield jacks 30 are pivotally mounted between the outer cylinder 12a and the rear body portion 14 at intervals in the circumferential direction.

Further, the inner cylinder 12b and the rear body portion 14 are connected via a folding pin 32.

On the other hand, a plurality of press jacks 34 and reaction force transmission jacks 36 fixed to the rear body section 14 are installed at intervals in the circumferential direction.

Each press jack 34 has a telescoping rod 34a and a cylinder 34b that accommodates the telescoping rod 34a.The telescoping rod 34a is inserted into a casing 38 with one end open, and its tip is pivotally connected with a pin 40, and the casing 38 is inserted into the casing 38 at the rear. It is attached by being fixed to the body 14, and a press ring 42 for compressing the lining concrete is attached to the rear end of the cylinder 34b.

In addition, the reaction force transmission jack 36 is also connected to the rear body section 1 through the casing 38a in the same manner as the press jack 34.
The telescopic rod 36a is fixed to the pin 40.
It is pivotally connected to the casing 38a at point a.

In other words, in the shield tunneling machine of this embodiment, the press jack 34 and the reaction force transmission jack 36 are
Each is stored in a casing, and the casing 38
and telescopic rods 34a, 36a are pivotally connected to each other so that each cylinder 34b, 36b can extend and contract rearward.

Note that the member 44 shown in FIG. 1 supports the screw conveyor 22, and
This is a frame on which a trolley 48 for transporting and attaching the formwork 46 is movably mounted.

Further, although detailed illustrations are omitted, sealing packing is interposed at necessary locations such as between the inner and outer cylinders 12a and 12b of the middle body portion 12.

The operation of the jacks 28, 30, 34, and 36 when performing curve construction using the shield tunneling machine having the above configuration will be explained based on FIG. 2.

Figure 2a shows a state in which the preparation for shield excavation has been completed, and in this state, the folding jack 28 and the shield jack 30 are stopped in a contracted state, and the reaction force transmission jack 36 is stopped in an extended state. ,
The press jack 34 compresses the lining concrete 50 placed through the press ring 42.

First, the deflection of the front torso 10 is as shown in FIG.
This is done as shown below.

The deflection of the front trunk section 10 stretches the plurality of folding jacks 28 located outside the direction of bending,
This reaction force is transferred to the formwork 4 via the reaction force transmission jack 36.
6 or into the lining concrete 50 via a press jack 34.

In this case, the cutter head 16 is driven by the drive motor 18.
The machine is rotated by the machine and moves forward while excavating earth and sand.

When the front trunk section 10 is deflected by a predetermined angle, the second
As shown in FIG. c, while the cutter head 16 is rotated by the cutter drive motor 18, the shield jack 30 is extended and excavation is performed.

In this case, the reaction force of the propulsion jack 30 is applied to the formwork 46 via the reaction force transmission jack 36 or to the lining concrete 50 via the press jack 34, and the excavated soil is transferred to the screw conveyor 22. While discharging to the outside, the outer cylinder 12a of the middle trunk section 12 gradually advances forward.

When the outer cylinder 12a of the middle body part 12 advances to the tip of the inner cylinder 12b, digging is completed, and each jack 28, 30, 34, 36 is stopped in its extended state, as shown in FIG. 2d.

Next, as shown in FIG. 2e, the press jack 34 and the reaction force transmission jack 36 are contracted to prepare for pouring the next stage of lining concrete.

When the preparation for pouring is completed, as shown in FIG. 2f, work is carried out to assemble reinforcing bars 52 and assemble a new formwork 46a to the existing formwork 46.

Since the formwork 46a used here is curved, the formwork 46a has different lengths on the top and bottom and on the left and right to accommodate the curve.

When a new lining concrete 50a is placed in front of the existing lining concrete 50, the rear body portion 14 moves forward as shown in FIG. 2g.

The forward movement of the rear trunk section 14 is achieved by extending the press jack 34 and the reaction force transmission jack 36 and contracting the shield jack 30.
This is done so that the inner cylinder 12b enters into the outer cylinder 12a.

In this case, the reaction force of the shield jack 30 accompanying the retraction and forward movement of the rear body section 14 is transferred to the reaction force transmission jack 36.
Since the compressive force of the press jack 34 that compresses the lining concrete 50a is only that necessary to compress the concrete 50a, it is almost unrelated to the reaction force when the rear body 14 moves forward. , and the influence of eccentricity of the rear body portion 14 is reduced.

Therefore, the radial component force acting on the lining concrete 50a due to the eccentricity of the press jack 34 does not pose a problem.

Then, the inner cylinder 12b of the middle body part 12 is connected to the outer cylinder 12a.
When the rear body 14 has penetrated a predetermined length into the interior, as shown in FIG. 2h, the forward movement of the rear body 14 is completed and the state shown in FIG. 2b is restored, and the same jacking operation and digging are repeated thereafter.

In the above embodiment, the shield tunneling machine is divided into three stages, but the implementation of the present invention is not limited to this, and the front body 10 of FIG.
It is also possible to have a two-stage structure in which the cutter head 16 and the like are arranged at the front end of the middle body part 12.

<<Effects of the Invention>> As described above in detail in the examples, according to the shield excavator for cast-in-place lining according to the present invention, almost no radial component force acts on the lining concrete during curved construction, so that the lining concrete can effectively prevent cracks.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a shield tunneling machine according to the present invention, and FIG. 2 is an explanatory diagram of a jacking operation during curve construction using the shield tunneling machine. 10... Front body part, 12... Middle body part, 14... Rear body part, 28... Center folding jack, 34... Press jack, 36... Reaction force transmission jack, 46, 46
a... Formwork, 50, 50a... Lining concrete.

Claims (1)

[Claims] 1 A front and rear torso divided into at least a plurality of parts,
A shield excavator for cast-in-place lining, which is equipped with a shield jack provided between these bodies, and a press jack that compresses lining concrete cast by installing a formwork behind the rear body. The press jack is fixed to the rear body, and the shield jack is fixed to the rear body and applies a propulsive reaction force of the shield jack to the formwork when the front body is propelled and when the rear body is retracted. A shield excavator characterized by being provided with a reaction force transmission jack.