JPH06105035B2 - 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.

<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.

Generally, when casting concrete in-situ, place an inner formwork inside the tail plate of the shield machine and move the machine forward with the reaction force applied to the formwork.At the same time, place concrete between the formwork and the ground. A shield machine to hit is adopted.

In this case, a plate member generally called a gable plate is arranged between the end face of the inner formwork on the face side and the tail plate to form the frame.

<Problems to be Solved by the Present Invention> The prior art has the following problems.

That is, considering the outflow of fresh concrete, the gap between the end plate and the inner peripheral surface of the tail plate cannot be set large.

Since the distance between the inner peripheral surface of the tail plate and the end plate is extremely small as described above, the end plate becomes an obstacle during correction of the excavation direction or during the construction of the curve, and the steerability of the shield machine is deteriorated.

Especially, when the radius of the curve becomes small, the construction may become impossible.

<Object of the present invention> The present invention has been made in view of the above points, and an object of the present invention is to provide a shield machine with excellent operability even when correcting the excavation direction of the shield machine or when performing a curve construction. To do.

<Structure of the Present Invention> An embodiment of the present invention will be described below with reference to the drawings.

<A> Overall configuration of the apparatus (Fig. 1) An inner formwork 5 is annularly positioned inside and 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 drainage of the cast concrete 7 from the end side is prevented by a press ring described later.

The placed concrete 7 is pressed by the press jack 6 via the press ring, but the concrete is continuously pressed by the pressure holding ring 1 after the press ring is removed.

<B> Pressure retaining ring (Fig. 1) The pressure retaining ring 1 is an annular disc.

The pressure retaining ring 1 is an assembly type ring member intended to reinforce the concrete 7 of the tunnel by continuously pressing the concrete 7 in cooperation with the tie rods 2 and then burying the concrete 7 as it is.

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.

When the plate width of the pressure retaining ring 1 is reduced, the gap amount between the tail plate 41 of the shield machine 4 and the inner formwork 5 is increased, and it is expected that fresh concrete will flow out.

On the contrary, if the plate width of the pressure retaining ring 1 is increased, it is expected that the steerability of the shield machine will be deteriorated when the direction is corrected or when the curve is constructed.

Therefore, according to the present invention, first, the plate width of the pressure holding ring 1 is reduced to avoid contact with the respective surfaces of the tail plate 41 and the inner formwork 5, and the steerability of the shield machine 4 is ensured.

Then, the press ring described below will regulate the outflow of fresh concrete.

<C> Press Ring (FIGS. 1 to 3) The press ring is composed of the annular box 3 and the annular gable plate 8.

(1) Annular Box The annular box 3 is a container having a shape in which a long hollow rectangular cylinder is bent into an annular shape.

As shown in FIG. 2, the annular box 3 is configured such that the side face on the face side can be separated.

The side surface of the annular box 3 on the face of the cutting face is detachably configured with, for example, bolts 32.

Further, the annular box 3 is configured to be dividable in the circumferential direction, as shown in FIG.

The divided annular boxes 3 can be connected and separated by bolts or the like.

Then, this annular box 3 is slidably mounted on the outer side of the most advanced thrust transmission mold 51 on the face side of the inner mold 5.

A plurality of insertion holes 33 for the tie rods 2 are formed on the front and rear surfaces of the annular box 3, and a working hole 34 for joining the tie rods 2 is formed on the body side of the annular box 3.

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

Further, a slit 31 is provided on the outer peripheral surface of the annular box 3 over the entire circumference.

(2) Annular end plate The annular end plate 8 is located in the slit 31 of the annular box 3.

The annular end plate 8 is not fixed to the annular box 3 but is positioned inside in a slidable manner in the circumferential direction.

The outer diameter of the annular gable plate 8 is formed to be substantially equal to the inner diameter of the tail plate 41.

<D> Operation of Annular End Plate The annular end plate 8 is slidably housed in the annular box 3.

The annular box 3 is a thrust transmission mold 51 at the end of the inner mold 5.
It is mounted on.

On the other hand, the inner formwork 5 maintains an accurate center line, and it is inevitable that the shield machine 4 moves up and down, left and right during the excavation and deviates from the center line.

However, the outer periphery of the annular gable plate 8 of the present invention has a shield machine 4
Touches the inside of the tail plate 41 of.

Therefore, the annular gable plate 8 moves freely in the annular box 3 and always serves as a gable plate to prevent the concrete from flowing out.

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

(A) Extension of tie rod 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) Subsequently, the pressure holding 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 to the side surface of the annular box 3 located on the thrust transmission frame 51 to assemble.

When assembling the pressure holding ring 1, as shown in FIG. 5, each tie rod 2 is fixed to the pressure holding ring 1 and the annular box 3 and the annular box 3 and the press jack 6 is fixed.
Penetrate inside.

(C) Assembly of Form (Fig. 6) Next, the inner form 5 is assembled inside the tail plate 41.

(D) Press-fitting of concrete (Fig. 7) The gable side is closed by the annular gable plate 8 and the annular box 3,
A shielded space surrounded by the inside of the inner frame 5 and the tail plate 41 is 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. 8) Next, when the press jacks 6 are simultaneously actuated and the tie rods 2 are pulled, the concrete 7 which is not yet hardened is pressurized.

While the concrete 7 is being pressed, the annular gable plate 8 is the tail plate.
Since it is in contact with 41, the outflow from the wife side of concrete 7 is regulated.

(F) Shield excavation (Fig. 9) The shield excavator 4 is advanced while extending the excavation jack 42 provided on the shield excavator 4 side 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.

(G) Fixing of pressure holding ring When excess water in the concrete 7 is discharged after completion of the shield promotion, the fixing hole is fixed by using the work hole of the annular box 3.
Tighten 21 and fix pressure retaining 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.

[Division of Annular Box] As described above, when assembling the pressure retaining ring 1,
When the pressure retaining ring 1 is temporarily fixed to the side surface of the annular box 3 with bolts or the like, or when each tie rod 2 is attached to the annular box 3
In the case of penetrating the inside, or in the case of fixing the pressure retaining ring 1 by the fixing tool 21 after the completion of the shield propulsion, fine work is performed and the work becomes complicated.

However, in the annular box 3 of the present invention, the side surface on the face side is separable.

Therefore, after separating the side surface on the face side, a wide open portion is formed.

Therefore, even when performing the detailed work as described above, it is possible to easily perform the work by inserting a hand or a tool from the widely formed open portion.

Moreover, the annular box 3 is configured to be dividable in the circumferential direction.

Therefore, it is possible to easily install or remove the concrete 7 on the gable side.

Further, since it can be divided during transportation, it can be easily transported.

(H) Removal of annular box After the fixing work of the pressure retaining ring 1 is completed, the annular box 3 is removed together with the thrust transmission form 51.

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

(I) At the time of passing a curve and correcting the 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. And always ring box 3
And the distance between the tail plate 41 and the tail plate 41 is compensated.

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

<Other Examples> In the above example, the annular end plate 8 is slidably positioned on the outer peripheral surface side of the annular box 3, but as another example, the reverse case is also possible. The same effect can be obtained.

That is, the outer diameter of the annular box 3 is formed to be substantially equal to the inner diameter of the tail plate 41, and the annular end plate 8 is formed to be slightly smaller than the inner diameter of the tail plate 41.

Then, a slit is provided on the inner peripheral surface side of the annular box 3,
In the structure, the annular gable plate 8 is slidably positioned in the circumferential direction in the slit.

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

(A) 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, since the annular gable plate of the present invention comes into contact with the inside of the tail plate and can freely move in the circumferential direction in the annular box, the gable side can always be completely closed.

(B) Since the annular gable plate that does not generate a gap between the formwork and the shield machine is slidably positioned, the shield machine can smoothly perform the construction of a curve having a small radius.

(C) In the present invention, when assembling the pressure retaining ring, when temporarily fixing the pressure retaining ring to the side surface of the annular box with bolts or the like, when penetrating each tie rod in the annular box, or after completion of shield promotion, When the pressure retaining ring is fixed by the fixing tool, fine work is performed and the work becomes complicated.

However, in the annular box of the present invention, the side surface on the face side is separable.

Therefore, after separating the side surface on the face side, a wide open portion is formed.

Therefore, even when performing the detailed work as described above, it is possible to easily perform the work by inserting a hand or a tool from the widely formed open portion.

(D) The annular box of the present invention is dividable in the circumferential direction.

Therefore, it is possible to easily install or remove concrete on the gable side.

Further, since it can be divided during transportation, it can be easily transported.

(E) Reinforcing bars and tie rods are embedded in concrete.

At this time, with the apparatus of the present invention, the work can be performed while keeping the covering margin from the inside of the concrete to the reinforcing bar constant.

[Brief description of drawings]

 Fig. 1: Explanatory diagram of one embodiment of the present invention Fig. 2, 3: Explanatory diagram showing disassembled state of annular box Fig. 4-9: Explanatory diagram of construction sequence

 ─────────────────────────────────────────────────── ─── 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-shi, Tokyo (72) Inventor Masayuki Akazawa 1-1-14-17 Minami-naruse, Machida-shi, Tokyo (56) Reference JP-A-60-261896 (JP, A) JP-A-62- 202199 (JP, A) Actual development Sho 56-125496 (JP, U)

Claims (1)

[Claims] 1. A shield machine in which an annular formwork is positioned behind the shield machine and a reaction force is applied to the formwork to advance the machine, and at the same time concrete is cast between the formwork and the ground. There is an annular pressure retaining ring that holds the compression of concrete by applying a reaction force to the reinforcement placed in cast-in-place concrete, and it is located close to the end side of the concrete, and the outer or inner surface It consists of a hollow annular box with slits that can be separated on the face side, and an annular gable plate that is slidably mounted in the slit of the annular box in the circumferential direction. The cast-in-place shield machine is characterized in that the outer diameter of the shield machine or the outer diameter of the gable plate is configured to be substantially equal to the inner diameter of the shield machine.