JP3090091B2 - Termination method of shield tunnel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a terminal portion of a shield tunnel excavated as a water discharge channel whose terminal portion opens into the sea such as a seaside.

[0002]

2. Description of the Related Art In recent years, shield tunnels used as, for example, water outlets of power plants are excavated by shield machines. In order to excavate the tail end of the tailrace so that it opens into the sea such as the seaside, a sealed shield machine configured with a partition wall on the front so that the earth and sand of the cutting face does not flow into the tunnel side is provided. In order to further lining the tail end of the water discharge channel, for example, as shown in FIG. 8 , the excavation of the shield tunnel 20 is completed, and when the tip of the shield machine 21 protrudes from the wall surface of the breakwater 22, the shield is firstly provided. The inside of the tunnel 20 is filled with seawater. Next, all the main devices of the shield machine 21 except the skin plate 24 such as the cutter desk 23 of the shield machine 21 are removed, and then the underwater concrete 25 is poured inside the skin plate 24.

[0003]

However, all work such as removal of the main equipment of the shield machine 21 such as the cutter desk 23 and placing of the underwater concrete 25 is underwater work, and underwater work largely depends on the weather. In addition to this, there is a problem that the work efficiency is low and the operation is very dangerous.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method of constructing a terminal portion of a shield tunnel which can improve the efficiency and safety of construction. .

[0005]

In order to solve the above-mentioned problems, a method of constructing a terminal portion of a shield tunnel according to the present invention comprises the steps of: excavating the shield tunnel and projecting the shield machine into water; Attach the bulkhead to the shield machine and close the tip of the shield machine in a sealed state, then remove the main equipment except the skin plate of the shield machine, and then cast concrete inside the skin plate to make the shield tunnel Lining the inner periphery of the terminal end of the above, and then removing the bulkhead.

At this time, after the bulkhead is attached to the tip of the shield machine to close the tip of the shield machine in a sealed state, before removing the main equipment of the shield machine, the partition located at the tip of the shield machine is removed. After draining the inside of the chamber composed of the bulkhead and the inside of the end of the shield tunnel, the inside of the shield tunnel is flooded before the bulkhead is removed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 of the Invention 1 to 7 show an embodiment of the present invention. In the drawings, reference numeral 1 denotes a dug from a shaft 2 constructed on land to the sea, and penetrates a breakwater 3 constructed on the seaside. , A shield tunnel whose end opens into the sea, 4 is a segment lining the inner periphery of the shield tunnel 1, and 5 is a shield tunnel 1
It is a shield machine that excavates.

Reference numeral 6 designates a cutter desk 8 of the shield machine 5 which is attached to the tip of a shield machine 5 which has finished excavating the shield tunnel 1 and penetrates the breakwater 3 and partially projects from the breakwater 3 into the sea. This is a bulkhead that removes all of the components and closes the tip of the shield machine 5 so that seawater does not flow into the shield tunnel 1 during the construction of the terminal end of the shield tunnel 1.

The breakwater 3 is constructed by, for example, driving a large number of steel sheet piles into the seashore to form an underground continuous wall, and then casting concrete into the underground continuous wall. Also,
A concrete segment or the like is used for the segment 4.

The shield machine 5 is a hermetic shield machine provided with a partition wall 10 on the front surface so as to prevent the earth and sand of the cutting face from flowing into the tunnel.
A skin plate 7 for holding the inner periphery of the shield tunnel 1 immediately after excavation, a cutter disk 8 for excavating the ground, a cutter shaft 9 for transmitting power for rotating the cutter disk 8, and an inflow of earth and sand. It is provided with a partition 10 and the like for blocking.

The bulkhead 6 is made of a steel plate or the like and has a bulkhead body 11 formed in the shape of a cap having substantially the same diameter as the outer diameter of the shield machine 5 and a reinforcing truss beam 12 attached to the outside of the bulkhead body 11. It is composed of The reinforcing beam 12 is, for example, bridged radially from the center of the bulkhead main body 11 to the peripheral direction or parallel to one direction.

A gasket 13 made of synthetic rubber or the like is interposed continuously between the bulkhead 6 and the shield machine 5 in the circumferential direction of the shield machine 5 and the bulkhead 6. Seawater is prevented from flowing into the interior.

Further, outside the abutting portion, a stopper 14 for fixing the bulkhead 6 so as not to come off from the tip of the shield machine 5 is continuous with the shield machine 5 and the bulkhead 6 in the circumferential direction or at a predetermined interval. Every other is attached.

After the distal end of the shield machine 5 is closed by the bulkhead 6 in this manner, the cutter disk 8, the cutter shaft 9, the partition 10 and the like are all removed, leaving only the skin plate 7, and further thereafter. Concrete 15 is cast inside the skin plate 7 to construct the terminal end of the shield tunnel 1.

Next, the construction method will be described step by step.

When the shield machine 5 has finished excavating the shield tunnel 1 and has penetrated the breakwater 3 and partially protrudes from the wall surface of the breakwater 3 into the sea, the cutter disc 8 is reduced in diameter to the inside of the skin plate 7 (FIG. 3).

Next, the tip of the shield machine 5 is attached to the bulkhead 6 to seal the tip of the shield machine 5 in a sealed state (see FIG. 3). The bulkhead 6 is assembled at a factory or on site, suspended by a crane ship 16 and submerged in the sea,
And it is installed at the tip of the shield machine 5 (see FIG. 2). At this time, the periphery of the bulkhead 6 is brought into close contact with the periphery of the skin plate 7 of the shield machine 5 via a gasket 13, and a stopper 14 is attached to the outside of the contact portion between the shield machine 5 and the bulkhead 6 to bulk The head 6 is fixed to the tip of the skin plate 7 so as not to come off (see FIG. 3).

Next, water in a chamber a including the partition wall 10 and the bulkhead 6 is forcibly drained by a drain pump (not shown). When the water in the chamber a is drained, the periphery of the bulkhead 6 is strongly pressed against the periphery of the skin plate 7 by water pressure, and the gasket 13 is crushed. Will be complete.

Next, all the main devices of the shield machine 5, such as the cutter disk 8, the cutter shaft 9, and the partition 10, are removed except for the skin plate 7 (FIG. 4).
reference). Then, concrete 15 is poured into the skin plate 7 to a predetermined thickness to cover the terminal end of the shield tunnel 1 (see FIG. 5).

Next, by supplying water to the shield tunnel 1 and flooding the inside of the shield tunnel 1, the inside and outside of the shield tunnel 1 are made to have the same water pressure.

When the inside and outside of the shield tunnel 1 have the same water pressure, the stopper 14 is removed, and the bulkhead 6 is suspended by the crane ship 16 and removed (see FIGS. 6 and 7).

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

According to the present invention, the method for constructing the end portion of the shield tunnel has the above-described structure. When the shield machine has protruded into the water after excavating the shield tunnel, a bulkhead is attached to the tip of the shield machine. Attach and seal the tip of the shield machine, then remove the main equipment except the skin plate of the shield machine, and then cast concrete inside the skin plate to set the inside of the shield tunnel end Lining the circumference,
Next, since the bulkhead is removed, the removal of the main equipment of the shield machine such as the cutter desk, the placement of concrete for lining, etc., all the work can be performed by dry construction, so the workability is extremely high, There are also effects such as extremely high safety.

After the bulkhead is attached to the tip of the shield machine to seal the tip of the shield machine, and before the main equipment of the shield machine is removed, the inside of the chamber is drained. Since the gasket is crushed by being strongly pressed by the water pressure around the skin plate, it is possible to reliably stop the water at the contact portion between the bulkhead and the skin plate.

Further, prior to removing the bulkhead, the inside of the shield tunnel is flooded to make the inside and outside of the shield tunnel have the same water pressure, so that the bulkhead can be easily removed.

[0040]

[0041]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a shield tunnel excavated from a shaft into the sea.

FIG. 2 is a longitudinal sectional view showing a construction state of a shield tunnel terminal end opening into the sea.

FIG. 3 is a longitudinal sectional view showing a construction state of a shield tunnel terminal end opening into the sea.

FIG. 4 is a vertical cross-sectional view showing a construction state of a shield tunnel terminal end opening into the sea.

FIG. 5 is a longitudinal sectional view showing a construction state of a shield tunnel terminal end opening into the sea.

FIG. 6 is a longitudinal sectional view showing a construction state of a shield tunnel terminal end opening into the sea.

FIG. 7 is a longitudinal sectional view showing a state after construction of a shield tunnel terminal end opening into the sea.

FIG. 8 is a longitudinal sectional view of a shield tunnel excavating from a shaft into the sea and having a terminal end opening into the sea.

[Explanation of symbols]

1 ... shield tunnel, 2 ... shaft, 3 ... breakwater, 4 ...
Segment, 5 ... shield machine, 6 ... bulk head,
7 ... skin plate, 8 ... cutter disk, 9 ... cutter shaft, 10 ... partition wall, 11 ... bulkhead body, 12 ...
Reinforced beams, 13 ... gaskets, 14 ... clamps, 15 ... concrete, 16 ... cranes.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E21D 9/06 301

Claims (3)

(57) [Claims] 1. A and excavation by the shield machine, the terminal end construction methods of the shield tunnel end portion is opened in the water, when the shield machine finished excavating shield tunnel projects into the water, in the shield machine
Attach the bulkhead to the tip of the skin plate to seal the tip of the shield machine, then remove the main equipment except the skin plate of the shield machine, and then cast concrete inside the skin plate Lining the inner periphery of the end of the shield tunnel, and then removing the bulkhead. 2. The method of claim 1] Sukinpure in the shield machine
After sealing the front end portion of the sheet Rudomashin attach the bulkhead to the tip portion of the over preparative, claims, characterized in that the draining chamber comprising a partition wall and bulkhead located at the top portion of the sheet Rudomashin 2. The method for constructing a terminal portion of a shield tunnel according to claim 1. 3. The method according to claim 1, wherein the shield tunnel is flooded before the bulkhead is removed.
Item 3. The method for constructing an end portion of a shield tunnel according to item 2 or 2.