JPH0784838B2 - Cast-in-place shield machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a shield machine that is constructed by casting concrete in-situ, and in particular, outflow of concrete that enters groundwater machine from the ground. The present invention relates to the configuration of a shield machine that can prevent the above.

<Prior Art> In constructing a shield tunnel, there are a method of assembling ready-made segments on site and a method of placing concrete on site using a formwork.

The present invention relates to the latter construction technique.

In general, when concrete is cast in situ, there is a problem that groundwater flows out before the concrete hardens again and flows into the shield machine, deteriorating the working environment and causing a part of the concrete to flow. .

<Purpose of the present invention> The present invention has been made to improve the above points, and a shield excavator configured to prevent groundwater from flowing into the shield excavator before the concrete hardens. It is intended to provide a configuration.

<Structure of the Present Invention> <B> Overall Structure (FIG. 1) The inner formwork 5 is positioned behind the shield machine 4.

The shield machine 4 is moved forward by applying a reaction force to the inner formwork 5.

On the other hand, the run-out of the cast concrete from the gable side is blocked by the pressure retaining ring 1 and the annular seal 9, but the pressure retaining ring 1 has no strength to stand on its own and is fixed to the sliding gable plate.

Then, the cast concrete is pressed by the press jack 6 via the pressure holding ring 1, and the sliding gable plate is positioned between the two.

<B> Pressure Retaining Ring The pressure retaining ring 1 is an annular disc plate.

The pressure retaining ring 1 is an assembling type ring member for cooperating with the tie rod 2 to continue to press the concrete and to be buried to reinforce the tunnel concrete.

A plurality of holes for penetrating the tie rods 2 are formed on the plate surface of the pressure retaining ring 1.

In order to improve the maneuverability of the shield machine 4, the plate width of the pressure retaining ring 1 is set smaller than the lining thickness of concrete.

As a result, contact with the respective surfaces of the tail plate 41 and the inner formwork 5 is avoided, and the steerability of the shield machine 4 is ensured.

Then, the sliding gable plates described below prevent the outflow of fresh concrete.

<D> Sliding end plate The sliding end plate is two annular plates, that is, the annular ring 3.
And the annular gable plate 8.

The annular ring 3 is a double plate body with a slit 31 interposed in the middle, and the annular end plate 8 can slide in the slit 31.

<E> Annular Ring The annular ring 3 has an outer diameter equal to the inner diameter of the tail plate 41 of the shield machine 4.

A large number of tie rods 2 are formed on the front and rear surfaces of the annular ring 3.
Open the insertion hole that penetrates the reinforcing material such as
A working hole for joining the tie rods 2 and the like is opened on the machine body side.

Further, a center hole jack is attached as a press jack 6 to the surface of the annular ring 3 on the leading end side.

<E> Annular end plate The outermost side of the annular end plate 8 having an inner diameter equal to the outer diameter of the inner formwork 5 is located in the slit 31 of the annular ring 3 so that the most advanced thrust transmission formwork 51 of the inner formwork 51. It is slidably mounted on the outer peripheral side of.

This annular gable plate 8 is not fixed to the annular ring 3 but
Both are slidably combined with each other in the radial direction of the tunnel.

<F> Operation of Annular End Plate The annular end plate 8 is slidably accommodated in the annular ring 3.

The annular end plate 8 is mounted on the thrust transmission mold 51 at the end of the inner mold 5.

During the construction, the inner formwork 5 maintains an accurate center line, while the shield machine 4 inevitably moves up and down, left and right during the excavation and deviates from the center line.

However, the outer periphery of the annular ring 3 of the present invention is a shield machine 4
Is in contact with the inside of the tail plate 41 of the
The inner surface of is in contact with the outer peripheral surface of the inner mold 5 or the thrust transmission mold 51 having the same diameter.

Therefore, the annular gable plate 8 freely moves in the annular ring 3, and at the same time, the two are always integrated to prevent the concrete from flowing out as a gable plate.

<G> Annular seal A groove is formed on the inner end of the tail plate 41 or a portion close to the end.

Then, a flexible annular pipe that can expand and contract freely is positioned as an annular seal 9 inside the groove.

The annular seal 9 is a bag like an elongated balloon, and is expanded and contracted by supplying compressed air or liquid.

<Operation of the present invention> Next, a tunnel construction method will be described.

<A> Extension of tie rods Fig. 4 shows the end of the concrete 7 constructed in the previous step.

A pressure retaining ring 1 and a tie rod 2 are exposed at the end of the concrete 7, and a fixing tool 21 is attached to the end of each tie rod 2.

In order to splice new concrete into this concrete 7, first, a connecting tool 22 is screwed onto the tie rod 2 protruding from the existing concrete 7 to connect a separate tie rod 2.

<B> Assembly of rings (Fig. 5) Next, the pressure retaining ring 1 divided into the tunnel is carried in.

In the tail plate 41 of the shield machine 4, the thrust transmission formwork 51 is separated from the inner formwork 5 and moved to the side of the machine by one span to be positioned.

Therefore, the pressure holding ring 1 is temporarily fixed and assembled on the side surface of the annular ring 3 positioned on the thrust transmission frame 51 via the annular end plate 8.

When assembling the pressure holding ring 1, as shown in FIG. 4, each tie rod 2 is penetrated into the pressure holding ring 1, the annular ring 3, and the press jack 6 fixed to the annular ring 3.

<C> Assembly of Form (Fig. 5) Next, the inner form 5 is assembled inside the tail plate 41.

<D> Press-fitting of concrete (FIG. 6) The end side is closed by the annular ring 3 and the annular end plate 8, and the pressure retaining ring 1 is attached to the annular ring 3.

As a result, the sliding gable plate, the inner formwork 5 and the tail plate
A shielded space surrounded by 41 and 41 will be formed.

Concrete 7 is poured into the entire shielded space from a concrete pouring pipe connected to the inner formwork 5.

<E> Pressurization of concrete (Fig. 7) Next, when the press jacks 6 are simultaneously actuated and the tie rods 2 are pulled, the concrete 7 in the unhardened state is pressed and the concrete 7 is pressed against the ground. Excess water is drained into the ground.

During pressurization of the concrete 7, since the annular gable plate 8 is in contact with the outer periphery of the inner formwork 5 or the outer periphery of the thrust transmission formwork 51 having the same size as the outer diameter of the inner formwork, The outflow is stopped.

<F> Shield excavation (Fig. 8) The shield excavator 4 is moved forward while the propulsion jack 42 provided on the shield excavator 4 side is extended to obtain a reaction force to the inner formwork 5.

Then, the tail plate 41 also moves to the face side simultaneously with the advance of the shield machine 4.

As a result, the concrete is pressed against the ground exposed by the passage of the tail plate 41.

Pressing with the press jack 6 is continued until the concrete 7 comes into close contact with the ground.

When the shield machine 4 is excavating, the annular seal 9 is contracted.

Therefore, the annular seal 9 is housed in the groove and does not protrude from the inner peripheral surface of the tail plate 41.

Therefore, when the shield machine 4 is propelled, the annular seal 9 does not hinder the propulsion, and the annular seal 9
There is no risk of damage to itself.

<G> Elimination of ground water The annular seal 9 is expanded until the concrete hardens.

Then, the groundwater flowing out from the ground is prevented by the annular seal 9 and does not flow into the shield machine 4.

At the same time, concrete that has not set yet does not flow out.

Although the expanded portion of the annular seal 9 remains as a groove, it is buried by pouring the next concrete.

<H> Fixing of pressure holding ring When the concrete exhibits a predetermined strength, the working hole of the annular ring 3 is used to tighten the fixing tool 21 to fix the pressure holding ring 1.

As the fixing tool 21, a screwing type, a wedge type, or a type in which depressions are arranged on the outer circumference of the tie rod 2 and a clip type that can be mounted from the lateral direction of the tie rod 2 can be adopted.

<R> Removal of end plate When the fixing work of the pressure holding ring 1 is completed, the annular end plate 8 and the annular ring 3 together with the thrust transmission form 51 are retracted and removed.

By repeating the above steps, concrete is successively spliced to construct a predetermined tunnel.

<N> When passing a curve and correcting direction When the tunnel passes through a curve or the direction of excavation is corrected, the annular gable plate 8 freely moves according to the relative movement amount of the shield machine 4 and the inner formwork 5. Therefore, the distance between the annular ring 3 and the tail plate 41 is always compensated.

Therefore, the shield machine 4 is allowed to move freely, so that the shield machine 4 can be installed smoothly.

<Le> Other Embodiments Above, the annular gable plate 8 which is in contact with the inner formwork 5 and the annular ring 3 which is in contact with the shield gutter 4 side of the sliding gable plate is described above.
However, as shown in FIG. 9, the opposite structure can be adopted.

That is, the slit 81 is provided between the double plate bodies, and the inner formwork 5
An annular ring 8a with a hole with an inner diameter approximately equal to the outer diameter of
And an annular end plate 3a having an outer diameter substantially equal to the inner diameter of the tail plate 41, and the annular end plate 3a is slidable in the circumferential direction within the slit 81 of the annular ring 8a.

A seal 82 is provided on the surface where the annular ring 8a contacts the inner mold form 5.
To position.

<Effects of the Present Invention> Since the present invention is as described above, the following effects can be obtained.

<A> An annular seal is positioned so that it can be expanded and contracted at or near the rear end of the shield machine.

Therefore, it is possible to prevent the groundwater that springs from the ground from flowing into the shield machine.

As a result, it is possible to prevent the deterioration of the working environment and prevent the outflow of concrete that has not yet solidified.

<B> The position of the inner formwork is always on the exact center line.

On the other hand, the shield machine cannot always excavate accurately.

Therefore, the distance between the two is constantly changing, and as a result, when concrete is poured, there is a possibility of concrete flowing out from the gable side.

However, the inner circumference of the slide gable plate is always in contact with the outer peripheral surface of the formwork, and the outer circumference of the slide gable plate is always in contact with the inner peripheral surface of the shield machine. It is carried out in the overlap portion on the outer peripheral side.

Therefore, even if no operation is performed, the slide gable plate and the outer peripheral surface of the formwork and the inner peripheral surface of the shield machine are always closed, so that concrete can be reliably prevented from flowing out.

Further, since the slide gable plate has a simple structure in which the annular box and the annular gable plate are simply combined, the cost can be reduced.

<C> The gable plate that does not create a gap between the formwork and the shield machine is slidably positioned.

Therefore, the size of the end plate of the concrete pouring form can be manufactured without considering the relationship with the inner diameter of the shield machine.

As a result, it is possible to smoothly carry out the construction of a curve having a smaller radius than before.

<D> In the present invention, the case where the reinforcing material such as the tie rod or the reinforcing bar is single has been described, but the work content is the same even when the reinforcing material is double.

Further, the reinforcing material is not limited to the tie rod, and it is of course possible to use a normal reinforcing bar, a flexible reinforcing bar having a larger flexibility, or any other known reinforcing material.

<E> If the annular seal is contracted, it will not protrude from the inner peripheral surface of the tail plate, so the annular seal will not hinder the propulsion when the shield machine is propelled.
Further, there is no possibility that the annular seal itself will be damaged.

<F> The shield machine of the present invention is a method of applying a propulsion reaction force to the inner formwork, and pressurizing the cast-in-place concrete by a press jack dedicated to pressurization which is separate from the propulsion jack.

Therefore, the pressure applied to the concrete can be finely adjusted by adjusting the hydraulic pressure of the press jack, and a good concrete lining can be obtained.

[Brief description of drawings]

 1 is an explanatory view of a construction state using the excavator of the present invention. FIG. 2 is a sectional view of an annular ring. FIGS. 3 to 8 is an explanatory view of a construction sequence. FIG. 9 is an explanatory view of another embodiment.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Nobuyuki Takamatsu 778-5, Taio-cho, Kohoku-ku, Yokohama-shi, Kanagawa (72) Inventor Hitoshi Nishio 2-3-17 Fujigaoka, Midori-ku, Yokohama-shi, Kanagawa (72) Inventor Maeda Koji 1-16-22 Naruse, Machida, Tokyo (72) Inventor Masayuki Akazawa 1-1-14, Naruse, Machida, Tokyo (56) References: 56-125496 (JP, U) Actual: 62-185794 (JP, U)

Claims (1)

[Claims] Claim: What is claimed is: 1. A device for locating a formwork behind a shield machine, advancing the machine by applying a reaction force to the inner formwork, and at the same time casting concrete into the formwork. An annular body with an outer diameter equal to the inner diameter of the tail plate and an annular body with an inner diameter equal to the outer diameter of the inner formwork are slidably combined in the radial direction of the tunnel to form a slide gable plate. A cast-in-place excavator with a groove on the rear inner surface of the tail plate outside the range of movement, and an inflatable annular seal installed in this groove.