JP2004308250A - Construction method for tunnel branch confluence part and structure of tunnel branch confluent part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To construct a structurally stable tunnel branch confluent part by a shielding construction method. <P>SOLUTION: Shafts 18 and 20 are constructed on both ends of the tunnel branch confluent part 10. The tunnel branch confluent part 10 is constructed by advancing boring by a large cross-sectional single circle shield machine 22 from the shaft 18 after reaching the shaft 18 by advancing the boring in a main line shielded tunnel 12. The branched main line shielded tunnel 14 and branch tunnel 16 are respectively constructed by advancing the boring by shield machines 24 and 26 from the shaft 20 after the large cross-sectional single circle shield machine 22 reaches the shaft 20. In another embodiment, a ground improved part is arranged instead of the shaft 20, and the branched main line shielded tunnel 14 and branch tunnel 16 are respectively constructed by advancing the boring by the shield machines 24 and 26 from this ground improved part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for constructing a tunnel branch junction by a shield method and a structure of a tunnel branch junction constructed by a shield method.
[0002]
[Prior art]
Conventionally, for example, a tunnel branching junction such as an underground road or a subway is generally constructed by an open-cutting method. However, in the excavation method, since a tunnel junction is excavated from the ground, a large work site is required on the ground, and there is a problem that traffic on the ground is obstructed during construction. In addition, it is difficult to secure a land in an urban area, and if a land cannot be secured at a planned place, the plan must be changed to provide a tunnel junction at another place.
[0003]
On the other hand, for example, Patent Literature 1 discloses a method of constructing a tunnel junction by a shield method. In this method, a shaft is constructed at one end of a tunnel junction, and a plurality of horizontal shield machines are dug from the shaft toward the other end to construct a tunnel junction. In parallel with this, the shield machine having a plurality of horizontal or single circles is excavated from both sides of the tunnel junction to reach the tunnel junction.
[0004]
[Patent Document 1]
Japanese Patent No. 2812208 Publication
[Problems to be solved by the invention]
As described above, in the construction method disclosed in Patent Literature 1, the tunnel junction is excavated by a plurality of horizontal shield machines. Therefore, as shown in FIG. 7, the cross-sectional shape of the tunnel branching junction has a shape in which a plurality of circular tunnel portions S1 to S3 are partially overlapped and arranged side by side. A tunnel having such a shape is structurally unstable, and as shown by a broken line in the figure, it is possible to reinforce the tunnel by providing a pillar P between adjacent shield tunnel portions S1 to S3. Required. However, since roads and railways must be able to join and branch in the tunnel junction, it is not possible to provide a column P between the shield tunnels S1 to S3 that hinders the junction. Therefore, instead of providing the pillars P, it is necessary to perform reinforcement work on the entire ceiling of the tunnel, and the work becomes extremely large.
The present invention has been made in view of the above points, and an object of the present invention is to make it possible to construct a structurally stable tunnel junction by a shield method.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 includes one or more first shield tunnels and a plurality of second shield tunnels that branch or merge with the first shield tunnel. A tunnel branching junction comprising: constructing the tunnel branching junction by excavating a single circular shield machine having a large cross-section that includes all of the cross sections of the first and second shield tunnels; The first shield tunnel is connected to one end of the tunnel junction, and the second shield tunnel is connected to the other end.
According to the present invention, the tunnel branching junction is constructed by excavating a large-section single-circle shield machine, so that a structurally stable tunnel branching junction can be constructed.
[0007]
According to a second aspect of the present invention, in the method for constructing a tunnel junction according to the first aspect, a shaft is constructed at an end of the tunnel junction at the first shield tunnel side. Constructing the tunnel junction by excavating the single-circle shield machine from the end toward the end on the second shield tunnel side.
[0008]
According to a third aspect of the present invention, in the method for constructing a tunnel junction according to the second aspect, a second shaft is constructed at an end of the tunnel junction on the side of the second shield tunnel. When the single-circle shield machine reaches the second shaft, collects the single-circle shield machine to the ground at the second shaft, and from the second shaft or toward the second shaft. And digging a shield machine for constructing each of the plurality of second shield tunnels to construct the plurality of second shield tunnels.
[0009]
According to a fourth aspect of the present invention, in the method for constructing a tunnel junction according to the second aspect, the single circular shield machine reaches an end of the tunnel junction at the side of the second shield tunnel. Then, the ground improvement is performed on the front face of the face, and from the ground improvement part or toward the ground improvement part, the shield machines for constructing the plurality of second shield tunnels are respectively dug and the plurality of the shield machines are dug. A second shield tunnel is constructed.
[0010]
According to a fifth aspect of the present invention, there is provided a tunnel branching junction comprising one or more first shield tunnels and a plurality of second shield tunnels branching or merging with the first shield tunnel. The tunnel branching junction is constructed by excavating a single circular shield machine having a large cross-section that includes all the cross sections of the first and second shield tunnels, and one end of the tunnel branching junction. And the plurality of second shield tunnels are connected to the other end thereof.
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a plan view showing a tunnel branching junction in the first embodiment of the present invention, and FIG. 2 is a diagram showing a cross-sectional shape of the tunnel branching junction. As shown in these drawings, in the present embodiment, at the tunnel junction 10, the main line shield tunnel 12 for constructing the main road A after the branch from the main line shield tunnel 12 for constructing the main road A. A description will be given of a case where the vehicle is branched into the branch line shield tunnel 16 for constructing the branch line road B. Of course, the main line shield tunnel 14 and the branch line shield tunnel 16 may be joined to the main line shield tunnel 12. The main line shield tunnel 12 corresponds to a “first shield tunnel” in the claims, and the main line shield tunnel 14 and the branch line shield tunnel 16 correspond to a “second shield tunnel” in the claims. .
[0012]
As shown in FIG. 1, shafts 18 and 20 are provided at both ends of the tunnel junction 10. Then, from the shaft 18 to the shaft 20, excavation is performed by a single-circle shield machine having a large cross-section (hereinafter, referred to as a large-circle single-circle shield machine) including the cross sections of the main line shield tunnels 12, 14 and the branch line shield tunnel 16. By doing so, the tunnel branching junction 10 is constructed.
[0013]
Drawing 3 is a figure for explaining the construction procedure of tunnel junction 10 in this embodiment. First, as shown in FIG. 3A, a shaft 18 is constructed at the end of the tunnel junction 10 on the near side of the branch (right side in the figure), and the shaft 18 is directed toward the shaft 18 from the right in the figure. The main line shield tunnel 12 is constructed by excavating the shield machine 21. The construction of the shaft 18 is completed before the shield machine 21 reaches the construction position. Then, when the shield machine 21 reaches the shaft 18, the shield machine 21 is collected from the shaft 18 to the ground.
[0014]
Next, in the shaft 18, a large-section single-circle shield machine 22 for constructing the tunnel junction 10 is assembled, and as shown in FIG. 3B, the shield machine 22 is excavated from the shaft 18 to the left in the figure. Thus, the tunnel branching junction 10 is constructed. As described above, the shield machine 22 has a large-diameter shield including the cross sections of the main line shield tunnels 12 and 14 and the branch line shield tunnel 16. In parallel with the excavation of the large-section single-circle shield machine 22, a shaft 20 is constructed at the end on the forward side (left side in the figure) of the tunnel junction 10. The construction of the shaft 20 is completed before the large-section single-circle shield machine 22 reaches the construction position. When the large-section single-circle shield machine 22 reaches the shaft 20, the shield machine 22 is recovered from the shaft 20 to the ground.
[0015]
Next, assembling the shield machines 24 and 26 for constructing the main line shield tunnel 14 and the branch line shield tunnel 16 in the shaft 20, respectively, as shown in FIG. The main line shield tunnel 14 and the branch line shield tunnel 16 are constructed. As the shield machine 24 for the main line shield tunnel 14, the shield machine 21 used for constructing the main line shield tunnel 12 can be reused.
[0016]
As described above, according to the present embodiment, since the tunnel branching junction 10 is constructed by the shield method, the construction of the tunnel branching junction 10 only needs to be able to secure the sites of the shafts 18 and 20 on the ground. Therefore, as compared with the case of the open-cutting method, much less land is to be secured on the ground, thereby minimizing the influence on the traffic on the ground and the like. The degree of freedom in planning the construction site of the building will also be greatly improved.
[0017]
Further, since the tunnel branching junction 10 is excavated by the large-section single-circle shield machine 22, the cross section of the tunnel branching junction 10 has a structurally extremely stable single circular shape. Therefore, it is not necessary to reinforce the tunnel branching junction 10 by constructing a pillar or the like. Therefore, according to the present embodiment, it is possible to freely perform branching and merging of the main line of a road or a railway constructed inside the tunnel branching junction 10, and to perform reinforcement work on the tunnel branching junction 10. Can also be eliminated.
[0018]
Next, a second embodiment of the present invention will be described. FIG. 4 is a plan view illustrating a tunnel junction according to a second embodiment of the present invention. The cross-sectional view of the tunnel junction is the same as that in FIG. 2 and is omitted, and the same components as those in the first embodiment are denoted by the same reference numerals. As shown in FIG. 4, in the present embodiment, only the shaft 18 of the first embodiment is constructed, and a ground improvement unit 30 is provided instead of the shaft 20.
[0019]
Also in the present embodiment, the tunnel branching junction 10 is constructed by excavating the large-section single-circle shield machine 22 from the shaft 18 in the same manner as the steps shown in FIGS. 3A and 3B in the first embodiment. I do. FIGS. 5 and 6 show the procedure from the construction of the tunnel branching junction 10 by the large-section single-circle shield machine 22 to the construction of the main line shield tunnel 14 and the branch line shield tunnel 16.
[0020]
First, after the excavation of the large-section single-circle shield machine 22 is stopped, the steel shell (skin plate) 22a is buried and the shield machine 22 is dismantled (FIG. 5A). The ground improvement part 30 is provided by injecting a chemical into the water (FIG. 5B). However, the ground improvement unit 30 may be provided by means other than injection of the medicine, such as freezing the ground. Next, the starting stand 34 of the shield machine 24 for the main line after branching, the main body of the shield machine 24, and the reaction force receiver 36 of the shield machine 24 are sequentially assembled (FIGS. 5C to 5E). 24 is started and the main line shield tunnel 14 is dug (FIGS. 5 (f) and 6 (a)). As the shield machine 24, the shield machine 21 used for constructing the main line shield tunnel 12 can be reused. Similarly, for the branch line shield tunnel 16, the starting stand 38 of the branch line shield machine 26, the main body of the shield machine 26, and the reaction force receiver 40 are sequentially assembled (FIGS. 6B to 6D), and the shielding is performed. The machine 26 is started to excavate the branch line shield tunnel 16 (FIGS. 6E to 6F).
[0021]
As described above, in the present embodiment, the construction of the shaft 20 in the first embodiment can be omitted, so that the construction of the tunnel junction 10 can be simplified, and only one site for the shaft is secured on the ground. Only a small amount of land needs to be secured on the ground. Then, similarly to the first embodiment, since the cross-sectional shape of the tunnel branching junction 10 becomes a structurally extremely stable single circle, inside the tunnel branching junction 10, the branching junction of the road or the track is formed. This can be performed freely, and it is not necessary to perform reinforcement work on the tunnel junction 10.
[0022]
In the above embodiments, after the tunnel branching junction 10 is constructed, the shield machines 24 and 26 are started from the shaft 20 or the ground improvement unit 30 to excavate the main line shield tunnel 14 and the branch line shield tunnel 16. However, the present invention is not limited to this, and the shield machines 24 and 26 may be excavated toward the shaft 18 or the ground improvement unit 30 in the opposite direction to the above embodiments.
[0023]
In the above-described embodiment, the case where one shield tunnel (main line shield tunnel 12) and two shield tunnels (main line shield tunnel 14 and branch line shield tunnel 16) are branched and joined is described. The present invention is not limited to this, and can be applied to a case where one shield tunnel and three or more shield tunnels branch or join, or a plurality of shield tunnels and two or more shield tunnels branch and join. is there. In these cases as well, a tunnel branch junction is constructed with a single circular shield machine having a large cross-section that includes the entire cross section of the shield tunnel to be merged, and each shield tunnel to be merged is connected to both ends. What should I do?
[0024]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, a structurally stable tunnel junction can be constructed by the shield method. For this reason, it is possible to perform branching and joining of roads and railroads within the tunnel branching and joining section without reinforcing the constructed tunnel branching and joining section.
[Brief description of the drawings]
FIG. 1 is a plan view showing a tunnel junction according to a first embodiment of the present invention.
FIG. 2 is a view showing a cross-sectional shape of a tunnel branching junction shown in FIG. 1;
FIGS. 3 (a) and 3 (b) are diagrams for explaining a procedure for constructing a tunnel junction in this embodiment.
FIG. 4 is a plan view showing a tunnel branching junction in a second embodiment of the present invention.
FIGS. 5 (a) to 5 (f) show a procedure from the construction of a tunnel branch junction using a large-section single-circle shield machine to the construction of a main line shield tunnel and a branch line shield tunnel after branching. FIG.
FIGS. 6 (a) to 6 (f) show a procedure from the construction of a tunnel branch junction using a large-section single-circle shield machine to the construction of a main line shield tunnel and a branch line shield tunnel after branching. FIG.
FIG. 7 is a diagram showing a cross-sectional shape of a tunnel branching junction constructed by a conventional method.
[Explanation of symbols]
Reference Signs List 10 Tunnel junction 12, 14 Main line shield tunnel 16 Branch line shield tunnel 18, 20 Vertical shaft 21, 24, 26 Shield machine 22 Single-section shield machine with large cross section 30 Ground improvement unit

Claims (5)

A method for constructing a tunnel branching / joining part comprising one or a plurality of first shield tunnels and a plurality of second shield tunnels branching or merging with the first shield tunnel,
The tunnel branch junction is constructed by excavating a single-section shield machine having a large cross-section including all of the cross sections of the first and second shield tunnels, and the first shield is connected to one end of the tunnel branch junction. Connecting a tunnel and connecting the second shield tunnel to the other end. 2. The tunnel branching junction construction method according to claim 1, wherein a shaft is constructed at an end of the tunnel branching junction on the first shield tunnel side, and the single-circle shield machine is connected to the second shield from the shaft. Constructing said tunnel junction by excavating towards a tunnel end. 3. The method for constructing a tunnel junction according to claim 2, wherein a second shaft is constructed at an end of the tunnel junction on the side of the second shield tunnel, and the single-circle shield machine is used for the second shaft. , The single circular shield machine is recovered to the ground at the second shaft, and the plurality of second shield tunnels are respectively constructed from the second shaft or toward the second shaft. Constructing said plurality of second shield tunnels by excavating a shield machine to perform the operation. In the method for constructing a tunnel junction according to claim 2, when the single-circle shield machine reaches an end of the tunnel junction where the second shield tunnel is located, the front face of the shield face is subjected to ground improvement, and Constructing the plurality of second shield tunnels by digging a shield machine for constructing each of the plurality of second shield tunnels from the ground improvement unit or toward the ground improvement unit; how to. A tunnel branching / joining structure comprising one or a plurality of first shield tunnels and a plurality of second shield tunnels branching or joining the first shield tunnel,
The tunnel junction is constructed by excavating a single circular shield machine having a large cross-section that includes all of the sections of the first and second shield tunnels, and the first shield is connected to one end of the tunnel junction. A structure of a tunnel junction where a tunnel is connected and the second shield tunnels are connected to the other end.

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