JPH01131792A - Shield excavator - Google Patents

Abstract

PURPOSE: To prevent a crack from occurring by providing reaction transmitting jacks transmitting thrust reaction of shield jacks to a form, so as not to apply component force in the radial direction to lining concrete at curved construction. CONSTITUTION: This shield machine constituted of a front body part 10, an intermediate body part 12, and a rear body part 14 is respectively provided with a plurality of bend type jacks 28, shield jacks 30, press jacks, and reaction transmitting jacks 26. In curved construction, the jack 28 on the outside to be bent is extended to deflect the front body part 10, the jacks 30 are extended to advance while rotating a cutter head 16, the outer cylinder of the intermediate body part 12 is advanced, and lining concrete 50a of the next step is placed. By extending the jacks 34, 36 and contracting the jacks 30, the rear body 14 is drawn in to be advanced, but reaction of the jacks 30 is taken with a form 46 through the jacks 36, and force applied to the concrete 50a due to eccentricity of the rear body 14 is reduced.

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.

(Prior Art) 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. Concrete lining inside the tunnel while applying compressive force!・Form and perform lining.

By the way, when performing curved construction using the conventional shield construction method, a center-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;
During curved 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 of 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 at least a plurality of divided front and rear body parts, a shield jack provided between these body parts, and a shield jack provided between the front and rear body parts. A shield excavator for cast-in-place lining, which is equipped with a press jack for compressing soldering concrete cast by installing a formwork behind the body, the press jack being fixed to the rear shoulder, and A reaction force transmission jack is fixed to the rear body and transmits the propulsive reaction force of the shield jack to the formwork when the front body is propelled and when the rear body is retracted. .

(Function) According to the shield tunneling machine having the above configuration, even if the front trunk side is eccentric during curve construction, the propulsive reaction force when contracting the shield jack and pulling the rear trunk toward the front trunk side is Since the lining concrete is transferred to the formwork via a reaction 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.
The influence of eccentricity is reduced.

(Embodiments) 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 same figure is divided into three stages so that it can perform curved construction. Middle torso 12, back shoulder 1
It has 4.

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

Further, a partition wall 20 is provided on the front body part 10 on the back side of the cutter head 16, and the cutter head 16, the front body part 10, and the partition wall 20 form a compartment 21 for storing excavated earth and sand. A screw conveyor 22 for discharging earth and sand inside 21 to the outside 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 part 12 in order to accommodate curved aS work, and is divided into two parts, a primary screw conveyor 22a and a secondary screw conveyor 2.
2b is connected to each screw conveyor 22a via a flexible member 24.

22b is rotationally driven by a drive motor 26.

The middle J1 section 12 is a double cylinder that is slidable in the axial direction and consists of an outer cylinder 12a and an inner cylinder 12b.
A plurality of center-folding jacks 28 are pivotally mounted between 2a and the front body portion 10 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 thereto are installed on the rear body section 14 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 pivoted 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.

Further, the reaction force transmission jack 36 is also fixed to the rear body section 14 via the casing 38a, similar to the press jack 34.
The telescopic rod 36a is connected to the casing 38a by the bin 40a.
It is pivoted to.

That is, in the shield excavator of this embodiment, the press jack 34 and the reaction force transmission jack 36 are housed in the casing, and the casing 38 and the telescopic rod 34a,
36a is pivotally connected to each cylinder 34b, 36b.
It is configured so that it can extend and contract backwards.

Note that the member 44 shown in FIG. 1 supports the screw conveyor 22 and has a formwork 46 on the upper surface.
It is a pedestal on which a trolley 48 for transportation and installation is movably mounted.

In addition, although detailed illustration is omitted, the inner and outer cylinders 1 of the middle body part 12
A sealing backing is interposed at necessary locations such as between 2a and 2b.

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

FIG. 2(a) shows a state in which preparations for shield excavation have 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 in an extended state. The press jack 34 is compressing the lining concrete 50 placed through the press ring 42.

First, the front body portion 10 is deflected as shown in FIG. 2(b).

The deflection of the front body part 10 stretches the plurality of folding jacks 28 located outside in the direction of bending, and this reaction force is taken by the formwork 46 via the reaction force transmission jack 36, or
Lining concrete 5 via press jack 34
Set to 0.

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

When the front trunk section 10 is deflected by a predetermined angle, as shown in FIG.
As shown in FIG. 2, excavation is performed by extending the shield jack 30 while rotating the cutter head 16 by the cutter drive motor 18.

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 discharged to the outside by the screw conveyor 22. At the same time, the outer cylinder 12a of the middle trunk section 12 gradually advances forward.

When the outer tm12a of the central and southern part 12 advances to the tip of the inner cylinder 12b, excavation is completed, and the jacks 28, 30, 34, 36 are stopped in their respective extended states, as shown in FIG. 2(d).

Next, as shown in FIG. 2(e), the press jack 3
4 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. 2(f), the work of assembling the reinforcing bars 52 and assembling the new formwork 46a to the existing formwork 46 is performed.

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.

Then, when a new lining concrete 50a is poured in front of the existing lining concrete 50, a second lining concrete 50a is placed in front of the existing lining concrete 50.
As shown in Figure (g), the posterior nuchal section 14 is moved forward.

The rear body part 14 moves forward by extending the press jack 34 and the reaction force transmission jack 36 and contracting the shield jack 30, so that the inner cylinder 12b of the middle body part 12 moves into the outer cylinder 1.
This is done by penetrating into 2a.

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 formwork 4 through the reaction force transmission jack 36.
6a, the compressive force of the press jack 34 that compresses the lining concrete 50a is equal to the concrete 50
It is only necessary to compress the rear body part 81$14, and has almost no relation to the reaction force when the rear body part 81$14 is drawn forward, so that the influence of eccentricity of the rear body part 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.

When the inner fm 12b of the middle body part 12 enters the outer cylinder 12a by a predetermined length, as shown in FIG. 2(h),
The forward movement of the rear trunk section 14 is completed, and the state returns to the state shown in FIG. 2(b), 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 present invention is not limited to this, and the front body 10 shown in FIG. 1 can be removed and the cutter head 16 etc. It may also be of a two-stage configuration in which the middle syllable part 12 is arranged at the front end.

(Effects of the Invention) As described above in detail in the embodiments, 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. can effectively prevent cracks.

[Brief explanation of the drawing]

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 torso 12... Middle torso 14...
・Rear body part 28...Central folding jack 34...
Press jack 36...Reaction force transmission jack 46.4
6a... Formwork 50.508... Lining concrete patent applicant Obayashi Sodo Co., Ltd.
Sodo Okumura Co., Ltd. Hitachi Zosen Co., Ltd. Representative Patent Attorney - Ken Iro Hakuma
Patent Attorney Masatoshi Matsumoto Figure 2 Figure 2

Claims (1)

[Claims] A front and rear body divided into at least a plurality of parts, a shield jack installed between these body parts, and a press jack that compresses lining concrete that is placed by installing a formwork behind the rear body. A shield excavator for cast-in-place lining, comprising: a press jack fixed to the rear body; A shield excavator characterized in that a reaction force transmission jack is provided for transmitting a propulsive reaction force of the shield jack to the formwork.