JPH04231596A - Cut-off method and cut-off construction of shield machine - Google Patents

Abstract

PURPOSE:To construct safely and surely a vertical shaft base and to make underwater connection, etc., by pushing a cut-off plate into a space between a shield machine body and a cutter face, or placing concrete between the cutter face and a partition wall. CONSTITUTION:A cylindrical cut-off plate 11 is pushed into a space 10 between a shield machine body 1 and a cutter face 5 to blockade the space 10 for stopping water. Concrete 15 is placed in an excavation chamber 14 between the cutter face 5 and a partition wall 4, or concrete is also placed in the peripheral surface to reinforce the cut-off plate 11 from the inside and the outside. A cut-off construction is constituted of the cylindrical cut-off plate 11, a means 13 to push it out and a seal rubber 12, the cut-off plate 11 is pushed out to bring it into contact with the seal rubber 12, and water is stopped. According to the constitution, construction of a vertical shaft base and horizontal underground connection, etc., can be made surely and efficiently.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and structure for stopping water between the tip of a skin plate of a shield machine body and a cutter face.

0002

[Prior Art] In the shield construction method, the cutter face of the shield machine is rotated to excavate and take in earth and sand at the face.
There is a gap between the cutter tip and the cutter face. Ground water coming from the surrounding ground is stopped by the shield machine's bulkhead (pressure wall). For this reason, until now it has been thought that there is no need to provide a water stop to the gap between the shield machine body and the cutter face.

0003

[Problems to be Solved by the Invention] When a shaft is constructed using the shield construction method, it is necessary to construct a shaft bottom at the deepest part to stop groundwater and withstand groundwater pressure. However, in the conventional technology, there is no safe, reliable, and efficient construction method for the shaft bottom, and this is an issue that needs to be solved.

[0004] In addition, when constructing a long horizontal tunnel using a shield machine, two tunnels were excavated in opposing positions and approached each other.
A method of joining a base shield machine underground is already known and has been practiced (for example, Japanese Patent Laid-Open No. 167895/1983). Specifically, as shown in Figure 3, a freezing pipe 2 is installed toward the surrounding ground between two shield machines 1 and 1 that are close to each other, and the surrounding ground is frozen over a fairly wide area. Many methods are adopted in which the bulkhead 4 and cutter face 5 of the shield machine 1 are dismantled and recovered by providing the ground 3 with resistance to groundwater pressure. However, freezing the surrounding ground takes a lot of time and money, so it is necessary to limit the frozen area as small as possible to increase efficiency. To do this, the gap between the shield machine body and the cutter face must be It is important to shut off the water as appropriate.

As a different method of underground bonding, as shown in FIG. 4, an over-drilling cutter 6 is made to protrude from the outer periphery of the cutter face 5 to over-drill the outer peripheral ground, and this over-excavated portion 7 is filled with concrete. 8, and this ring-shaped concrete 8
A method for performing underground bonding while protecting against earth pressure and groundwater pressure has also been developed (for example, Japanese Patent Laid-Open No. 167895/1983). However, in this case as well, unless the water is stopped in the gap between the shield machine body 1 and the cutter face 5, the poured concrete will go around into the excavation chamber 14, making it extremely difficult to dismantle and recover the cutter face 5 and the like. Therefore, there is an urgent need to develop an appropriate water-stopping method and structure for the gap between the shield machine body and the cutter face 5.

[0006]

[Means for Solving the Problems] As a means for solving the above-mentioned problems of the prior art, a method for stopping water in a shielding machine according to the present invention includes a method in which a cylindrical shape is provided in the gap 10 between the shielding machine body 1 and the cutter face 5. Push out the water stop plate 11 to close the gap and stop water, or push out the cylindrical water stop plate 11 into the gap 10 between the shield machine body 1 and the cutter face 5 to close the gap 10 and stop water. At the same time, concrete 15 is poured into the excavation chamber 14 between the cutter face 5 and the partition wall 4, or concrete is also poured around the outer circumference of the shield machine body 1 which has been excavated with an enlarged diameter, and the water stop plate 11 is installed from the inside. , or stiffening from the inside and outside.

Further, the water-stopping structure of the shielding machine according to the present invention includes a cylindrical water-stopping plate 11 housed on the side of the shielding machine main body 1, a means 13 for pushing out the water-stopping plate 11, and a cutter face 5. The water stop plate 1 on the side of
It is characterized by a sealing rubber 12 installed at a portion where the water stopper plate 1 comes into contact with the water stopper plate 11, and the water stopper plate 11 is pushed out and brought into contact with the sealer rubber 12 to perform waterstopping.

[0008]

[Operation] When the water stop plate 11 is pushed out and strongly pressed against the seal rubber 12 of the cutter face 5, the gap 10 between the shield machine body 1 and the cutter face 5 is completely closed. Therefore, it is possible to prevent the infiltration of groundwater coming from the surrounding ground, or to prevent the concrete from going around into the excavation chamber 14 when concrete 8 is placed in the over-excavation part 7 as shown in FIG.

[0009]

Embodiments Next, illustrated embodiments of the present invention will be described. The shield machine 1 shown in FIGS. 1 and 2 is an example of a vertical shield machine that excavates vertically downward to construct a vertical shaft. An annular hydraulic chamber 13 that opens downward in the axial direction is formed at the tip of the shield skin plate, and a cylindrical water stop plate 11 having an annular piston that can freely slide inside the hydraulic chamber 13 can move forward and backward. It is installed. The forward and backward stroke of the water stop plate 11 is set to about 30 cm so that the gap 10 between the tip of the shield skin plate of the shield machine 1 and the cutter face 5 can be completely closed. On the other hand, a seal rubber 12 is installed in an annular shape at a portion of the inner surface of the cutter face 5 where the tip of the water stop plate 11 comes into contact.

Therefore, in order to construct a shaft to a desired depth using this vertical shield machine 1, and to stop underground water and construct a shaft bottom that can withstand underground water pressure, first, hydraulic pressure is supplied into the hydraulic chamber 13 to stop the shaft. The water plate 11 is pushed out and strongly pressed against the seal rubber 12 of the cutter face 5. As a result, the shield machine body 1 and cutter face 5
The gap 10 between the ground and the ground is closed, and the infiltration of groundwater from the surrounding ground can be prevented. Concurrently with this, underwater concrete 15 is poured into the excavation chamber 14 between the partition wall (pressure wall = bulkhead) 4 and the cutter face 5 by a mud water displacement method. When this concrete 15 hardens and develops strength, it stiffens the water stop plate 11 from the inside, creating a structure that can permanently withstand underground water pressure. In this case, the cutter face 5 is buried.

Note that the means for pushing out the water stop plate 11 is not limited to the above-mentioned hydraulic type. screw jack mechanism,
Alternatively, it is possible to adopt and implement a push bolt mechanism or other methods.

0012

[Second Embodiment] When joining the two horizontal shield machines 1, 1 shown in FIG. When it stops rotating,
The shield machine body 1 is made by protruding each water stop plate 11.
A gap 10 between the cutter face 5 and the cutter face 5 is closed to stop water. Therefore, the inflow of earth and sand and groundwater from the ground around the joint is limited to only the circumferential portion 17 at the front of the shield machine. Therefore, freezing of the surrounding ground by the freezing pipe 2 can be limited to the minimum necessary area and can be efficiently carried out in a short period of time. After the frozen ground 3 is completed, the work to penetrate the horizontal tunnel is carried out by giving it a capacity to withstand underground water pressure.

[0013]

[Third Embodiment] The underground joining of the two horizontal shield machines 1, 1 shown in FIG. An over-drilling cutter 6 is made to protrude from the outer periphery of the trench 5 to perform over-drilling of the surrounding ground. After that, the water stop plate 11 is pushed out and the shield machine body 1 is removed.
A gap 10 between the cutter face 5 and the cutter face 5 is closed to shut off water. Furthermore, the earth and sand intake slit attached to the front face of the face is closed to create a closed space inside the chamber. Next, underwater concrete 8 is placed in the overexcavation part 7 using a mud water replacement method. At this time, the water stop plate 11 can prevent concrete from flowing into the chamber. When the ring-shaped concrete 8 hardens and develops strength, it becomes a structure that protects against earth pressure and underground water pressure, so the inner partition wall 4 and cutter face 5 are dismantled and removed, and the chamber Underground joints can be completed at a high rate without the need for concrete.

[0014]

[Effects of the present invention] According to the water-stopping method and water-stopping structure of a shielding machine according to the present invention, the construction of the shaft bottom section constructed by the shielding machine 1 and the horizontal underground connection can be carried out. It can be carried out safely, reliably, and efficiently without being adversely affected by groundwater or groundwater pressure.

[Brief explanation of the drawing]

FIG. 1 is a simplified cross-sectional view of a shield machine equipped with a water-stopping structure according to the present invention.

FIG. 2 is a cross-sectional view showing the shield machine of FIG. 1 in use.

FIG. 3 is a sectional view of underground bonding using the shield machine.

FIG. 4 is a sectional view of underground bonding using the shield machine.

[Explanation of symbols]

1 Shield machine 5 Cutter face 10 Gap 11 Water stop plate 15 Underwater concrete 13 Hydraulic chamber 12 Seal rubber

Claims (4)

[Claims] 1. A method for shutting off water in a shielding machine, which comprises pushing out a cylindrical water-stopping plate into the gap between the shielding machine body and the cutter face to close the gap and shut off water. . Claim 2: A cylindrical water stop plate is pushed out into the gap between the shield machine body and the cutter face to close the gap and stop water, and at the same time, the inside of the excavation chamber between the cutter face and the partition wall. A water stop method for a shield machine, which is characterized by reinforcing a water stop plate from the inside by pouring concrete on the surface of the shield machine. 3. A cylindrical water stop plate is extruded into the gap between the shield machine body and the cutter face to close the gap and stop water, and at the same time, the water stop plate is extruded into the gap between the shield machine body and the cutter face. A water stoppage method for a shield machine, which is characterized by pouring concrete on the outer periphery of the shield machine body, which has been excavated to enlarge its diameter, and reinforcing the water stop plate from the inside and outside by pouring concrete around the outer periphery of the shield machine body, which has been excavated to enlarge its diameter. 4. A cylindrical water stop plate housed in the shield machine main body, and means for pushing out the water stop plate.
It is characterized by comprising a seal rubber installed at a portion of the cutter face side where the water stop plate contacts, and the water stop plate is pushed out and brought into contact with the seal rubber to perform water stop. Water stop structure for shield machine.