JPH10176480A - Shield reaching method - Google Patents

Abstract

(57) [Summary] [Problem] To provide a shield reaching method that is advantageous in terms of economy, management, and construction period. SOLUTION: When the shield machine 2 reaches the reaching shaft, sealing means 4 and 5 are provided in advance on the outer periphery of the shield machine 2, and when the shielding machine 2 penetrates the pit wall 1 of the reaching shaft, the sealing means 4 is provided. , Shield machine 2 and mine wall 1 by 5
To seal the gap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield reaching method for allowing a shield machine which has excavated a ground to reach a reaching shaft.

[0002]

2. Description of the Related Art There are many problems when a closed pressurized shield arrives at a shaft, compared to when the shaft starts. At the time of starting, the entrance seal is attached to the wall of the starting shaft according to the outer circumference of the shield machine, and the ground is excavated in a sealed pressurized state by starting while directly excavating the excavated concrete wall. Is possible, but it is difficult to apply the method as it is upon arrival. The following can be considered as the reason.

(1) Since a sealed pressurized material such as muddy water is located in front of the shield machine, the requirement for water stoppage upon arrival is more severe than that upon start. (2) Since there is always an excavation error in the shield machine, it is difficult to predict a reaching position and install a sealing material on a pit wall of the reaching shaft in advance.

Therefore, in consideration of these facts, usually, the ground improvement method such as a freezing method or a chemical liquid injection method is applied to the ground on the arrival side, and then the shield machine is made to reach the arrival shaft. It is.

In recent years, a sealing means has been buried in concrete on a pit wall of a reaching shaft, and after the tip of the shield machine has passed through the sealing means, pressurized fluid is introduced into the sealing means to stop water. The method of construction is proposed.

[0006]

However, each of the above methods has a problem. That is, the method of performing ground improvement in advance on the arrival side ground has a problem that it is costly and the construction period is long. In addition, the method of incorporating the sealant in advance in the concrete of the pit wall of the reaching shaft requires that the reaching accuracy of the shield machine be considerably increased, and a pressurizing chamber needs to be provided in the shaft. There are problems that the cost is high and the management is difficult.

[0007] In view of the above circumstances, the present invention does not require ground improvement of the ground on the arrival side, does not require a very high accuracy of the shield machine, and does not require the construction of a pressurized chamber in the shaft. Therefore, it is an object of the present invention to provide a shield reaching method which is advantageous in terms of economy, management, and construction period.

[0008]

According to the shield reaching method of the present invention, when the shield machine reaches the reaching shaft, sealing means is provided in advance on the outer periphery of the shield machine, and the shield machine is connected to the reaching shaft. When penetrating the pit wall, a gap between the shield machine and the pit wall is sealed by the sealing means.

According to a second aspect of the present invention, there is provided the shield reaching method according to the first aspect, wherein the sealing means is provided in two or more stages at intervals in the excavation direction, and the distance from the tip of the shielding machine to the foremost sealing means; The distance between adjacent sealing means is set to be smaller than the thickness of the shaft of the reaching shaft.

According to a third aspect of the present invention, there is provided the shield reaching method according to the first or second aspect, wherein the sealing means is accommodated in a skin plate before reaching the reaching shaft, and is placed in the tube when reaching the reaching shaft. It is characterized by comprising a pressurized sealing mechanism which displaces to the outside of the skin plate by introducing a fluid and seals the gap between the skin plate and the peripheral surface.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a process diagram of the shield reaching method according to the present embodiment. In the figure, reference numeral 1 denotes a shaft wall of an reaching shaft, 2 denotes a shield machine, and 3 denotes a skin plate of the shield machine 2.

In the shield reaching method of the present embodiment, FIG.
As shown in (1), pressurizing sealing means 4 and 5 that are continuous in the circumferential direction are provided in advance on the outer periphery of the shield machine 2, that is, on the skin plate 3. As shown in FIG. 2, the sealing means 4, 5 in this case is housed inside the skin plate 3 before reaching the reaching shaft, and introducing a fluid into the tube 7 when reaching the reaching shaft. Therefore, a pressurized sealing mechanism that swells out of the skin plate 3 and seals between the skin plate 3 and the excavation hole peripheral surface 1a is used. In FIG. 2, 8 is a fluid introduction hole, and 9 is a protection plate.

As shown in FIG. 1A, two sealing means 4, 5 are provided at intervals in the direction of excavation. Distance A from tip of shield machine 2 to front sealing means 4
1, and the interval A2 between the front and rear sealing means 4, 5 is set smaller than the thickness B of the pit wall 1 of the reaching shaft.

After such preparation, as shown in FIG. 1, when the shield machine 2 penetrates the pit wall 1 of the reaching shaft, the sealing means 4 and 5 are appropriately operated (pressurized fluid is supplied to the tube). When the shield machine 2 is operated, the excavation is performed while sealing the gap between the shield machine 2 and the excavation hole peripheral surface 1a formed in the pit wall 1a.

That is, as shown in FIG. 1 (a), when the sealing means 4 at the tip enters the range of the thickness of the pit wall 1 of the reaching shaft, the first-stage sealing means 4 is operated under pressure. Continue digging. When the arrival is near, as shown in FIG.
Drilling is performed from the inside of the reaching shaft, and the jack of the shield machine 2 is operated to further advance the shield machine 2. Then, before the first-stage sealing means 4 passes through the pit wall 1 of the reaching shaft, the second-stage sealing means 5 is pressurized, and the shield machine 2 is similarly advanced, and the shield machine 2 is moved to the reaching shaft. 1
Reach inside. As a result, one of the sealing means 4 and 5 always seals the gap between the shield machine 1 and the pit wall 1a of the reaching shaft.

As described above, by appropriately operating the sealing means 4 and 5, the gap between the shield machine 2 and the pit wall 1 when penetrating the pit wall 1 of the reaching shaft can be reliably ensured over all stages during the excavation. Can be sealed. Therefore, it is not necessary to perform the ground improvement method on the arrival side ground. Also, there is no need to build a pressurized chamber in the arrival shaft. Furthermore, since the shield means 2 itself is provided with the sealing means 4 and 5,
Unlike the case where the sealing means is installed in the concrete of the pit wall 1a of the reaching shaft, not so high accuracy is required for the excavation reaching accuracy. As a result, it is possible to carry out all the constructions in terms of economy, management and construction period. In addition, since the pressurizing type is used as the sealing means 4 and 5, the sealing means 4 and 5 can be stored in the skin plate 3 when sealing is not necessary, and the sealing means can be used during excavation. 4 and 5 do not get in the way.

It is to be noted that, of the pit wall 1 of the reaching shaft, at least a wall at a position where the shield machine 2 penetrates is
For example, it is necessary to provide a wall excavated by the cutter, for example, a wall reinforced with resin or the like without a reinforcing bar.

If the skin plate 3 of the shield machine 2 cannot be left in the arrival shaft after the arrival is completed,
At the stage of FIG. 1 (c), a method of disassembling the skin plate 3 by injecting a waterproof material from the inside of the segment 10 toward the pit wall 1 of the reaching shaft can be adopted.

Further, the sealing means 4 and 5 are not limited to those of the above-described embodiment, but various means can be adopted. For example, a flapper-type sealing means can be used. The number of stages of the sealing means may be three or more. In this case, the same effect as described above can be obtained by setting the distance from the tip of the shield machine 2 to the foremost sealing means and the distance between adjacent sealing means smaller than the thickness of the pit wall 1 of the reaching shaft. Can be.

[0020]

As described above, according to the first aspect of the present invention, the gap between the shaft of the reaching shaft and the shield machine is sealed by the sealing means provided on the outer periphery of the shield machine. In addition, there is no need to implement the ground improvement method, and it is not necessary to build a pressurized chamber in the reaching shaft.
In addition, since the sealing means is provided on the shield machine side, very high excavation reaching accuracy is not required. Therefore,
The construction can be carried out advantageously in terms of economy, management and construction period.

According to the second aspect of the present invention, when the tip of the shield machine has penetrated the tunnel wall of the reaching shaft, the space between the tunnel and the tunnel can be sealed by the foremost sealing means. When the sealing means has passed through the pit wall of the arrival shaft, a seal can be formed between the pit wall and the sealing means on the rear side. Therefore, while the shield machine penetrates the reaching shaft wall, one of the sealing means always seals the gap between the shield machine and the reaching shaft wall,
Reliable sealing performance can be maintained throughout the reaching process.

According to the third aspect of the present invention, when the seal is not required, the seal means can be accommodated in the skin plate. And the sealing means does not hinder the excavation performance.

[Brief description of the drawings]

FIGS. 1A to 1C are process diagrams of a shield reaching method according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of a sealing means provided on the outer periphery of the shield machine in the same method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Depth wall of reaching shaft 2 Shield machine 3 Skin plate 4,5 Sealing means 7 Tube

Claims (3)

[Claims] When a shield machine reaches an arrival shaft, a sealing means is provided in advance on an outer periphery of the shield machine, and when the shield machine penetrates a pit wall of the arrival shaft, the shield machine and the tunnel are sealed by the sealing means. A shield reaching method characterized by sealing the gap with the wall. 2. The sealing means is provided in two or more steps at intervals in the excavation direction, and the distance from the tip of the shield machine to the foremost sealing means and the distance between adjacent sealing means are determined by the distance of the wall of the arrival shaft. The shield reaching method according to claim 1, wherein the thickness is set smaller than the thickness. 3. The drilling hole, wherein the sealing means is accommodated in a skin plate before reaching the reaching shaft, and is displaced to the outside of the skin plate by introducing a fluid into a tube when reaching the reaching shaft. 3. The shield reaching method according to claim 1, further comprising a pressure-type sealing mechanism for sealing a gap between the shield and the peripheral surface.