JPH0784839B2 - 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 outflow of the cast concrete 7 from the end side is blocked 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 working 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 and 2) The press ring is composed of an outer annular body having an outer diameter substantially equal to the inner diameter of the tail plate of the shield machine and an inner annular body having an inner diameter substantially equal to the outer diameter of the formwork. Are slidably combined with each other in the radial direction of the tunnel, and a plurality of recesses are provided along the inner peripheral surface of the outer annular body or the outer peripheral surface of the inner annular body. 3 and an annular gable plate 8.

(1) Annular Box The annular box 3 is a container having a shape in which a long hollow cylindrical column is bent in an annular shape, and has an inner diameter substantially equal to the outer diameter of the inner formwork 5.

The annular box 3 is slidably mounted on the outer side of the leading edge hydraulic power transmission form 51 on the face side of the inner form 5.

Further, many insertion holes for the tie rods 2 are opened on the front and rear surfaces of the annular box 3, and working holes for joining the tie rods 2 are opened 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 an annular plate body whose outer diameter is formed to be substantially equal to the inner diameter of the tail plate 41, and as shown in FIG. 2, along the entire circumference of its inner peripheral surface, A plurality of recesses 81 having a diameter larger than the diameter of the tie rod 2 are provided.

As will be described later, the recess 81 has a position that surrounds the tie rod 2 when the annular end plate 8 is pushed toward the tie rod 2.
Provide the same number as the tie rod 2.

Further, the annular gable plate 8 is configured to be dividable in the circumferential direction.

Therefore, assembly, disassembly, transportation and the like can be easily performed.

Then, the annular gable plate 8 is positioned 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 so as to be slidable relative to each other at the overlapping portion in the radial direction of the tunnel.

<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, while the annular gable plate 8 freely moves in the annular box 3, it 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. 3 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. 4) 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. 4, 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. 5) Next, the inner form 5 is assembled inside the tail plate 41.

(D) Press-fitting of concrete (Fig. 6) 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. 7) Next, when the press jacks 6 are simultaneously actuated and the tie rods 2 are pulled, the concrete 7 in the uncured state is pressed.

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. 8) 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.

(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.

[Operation of Concavity of Annular Gable Plate] When the shield machine 4 passes through a curved construction part or the like, the annular gable plate 8 located inside the curved construction part is pushed into the annular box 3 toward the tie rod 2 side. Become.

However, since the annular end plate 8 of the present invention is provided with the recess 81, the inner end face of the annular end plate 8 is pushed into the annular box 3 so as to surround the tie rod 2 without hitting the tie rod 2. Will be done.

Therefore, the distance that the annular gable plate 8 located inside the curved construction portion moves into the annular box 3 becomes long, and the tail plate 41 of the shield machine 4 can also follow and greatly move inward.

Therefore, the small-diameter curved portion of the tunnel can be easily constructed, and the operability of the shield machine 4 is improved.

<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.

In this case, the recess 81 of the annular gable plate 8 is also provided along the outer peripheral surface of the annular gable plate 8.

<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, the present invention, the inner periphery of the press ring is always in contact with the mold outer peripheral surface, the outer periphery of the press ring is always in contact with the shield machine inner peripheral surface, the change in the press ring width,
It is carried out in the superposition section of two annular bodies.

Therefore, even if no operation is performed, the press ring and the outer peripheral surface of the formwork and the inner peripheral surface of the shield machine are always closed, and it is possible to reliably prevent the concrete from flowing out.

Further, since the structure is simple, only two annular bodies are combined, and the cost can be reduced.

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

(C) When the shield machine passes through the curved construction portion or the like, the annular gable plate located inside the curved construction portion is pushed into the annular box toward the tie rod.

However, since the annular gable plate of the present invention is provided with the concave portion, the inner peripheral surface side of the annular gable plate is pushed into the annular box so as to surround the tie rod without hitting the tie rod.

Therefore, the annular gable plate located inside the curved construction portion has a long distance to move into the annular box, and the tail plate of the shield machine can also follow and greatly move inward.

Therefore, the small-diameter curved portion of the tunnel can be easily constructed, and the operability of the shield machine is improved.

(D) The annular gable plate is configured to be separable in the circumferential direction.

Therefore, assembly, disassembly, transportation and the like can be easily performed.

(E) A reinforcing material may be arranged in the axial direction of the tunnel between the ground and the formwork, and a reaction force may be applied to the reinforcing material to bury the pressure retaining ring to keep the concrete compressed.

As a result, prestress in the tunnel axial direction can be introduced into the tunnel frame, and the strength of the entire tunnel frame can be improved.

In addition, at this time, with the device of the present invention, it is possible to perform the construction while keeping the covering margin from the inside of the concrete to the reinforcing bar constant.

(F) Since the pressure retaining ring is left at the face end of each lining, it is possible to prevent concrete that has not yet solidified from flowing out to the face face.

Therefore, promotion of the shield machine and concrete pressing can be performed at the same time, and the construction time can be shortened.

(G) The shield machine of the present invention is a method in which a propulsion reaction force is applied to the inner formwork, and the cast concrete is pressed 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]

 FIG. 1: Explanatory diagram of an embodiment of the present invention FIG. 2: Explanatory diagram of annular gable plate FIGS. 3 to 8: Explanatory diagram of construction sequence

 ─────────────────────────────────────────────────── ─── Continuation of the 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-59-27093 (JP, A) JP-A-63- 223298 (JP, A) Actual development Sho 56-125496 (JP, U)

Claims (1)

[Claims] 1. A shield machine that positions an annular formwork behind the shield machine and advances the machine with reaction force to the inner formwork, and at the same time casts concrete between the formwork and the ground. The annular pressure retaining ring that holds the compression of the concrete by applying the reaction force to the reinforcement placed in the cast-in-place concrete, and the outside that has the outer diameter approximately equal to the inner diameter of the shield excavator tail plate. An annular body and an inner annular body having an inner diameter substantially equal to the outer diameter of the inner formwork are slidably combined with each other in the radial direction of the tunnel to form an inner peripheral surface of the outer annular body or an outer peripheral surface of the inner annular body. A cast-in-place excavator having a press ring formed by providing a plurality of recesses along the recess.