JP2006169924A - Execution method of branch part or junction of sealed tunnel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an execution method of a branch part or a junction of a sealed tunnel which minimizes the concurrent use of a freezing method, and which enables the construction of a branch/junction with great depths at a low cost and with safety. <P>SOLUTION: A temporary shielding machine 2 of a smaller diameter than that of the two shield tunnels 1 is started one by one from the rear position of the branch part or from the front position of the junction of the two shield tunnels 1 within the two shield tunnels 1 toward the branch part or the junction so that the temporary shielding machine 2 covers the outer periphery of the branch part or the junction. Then the temporary shielding machine 2 is passed through the branch part or the junction, and is recovered within a shield tunnel 1 which is at the front position of the branch part or the rear position of the junction. Thus, an exterior execution 3 covering the outer periphery of the branch part or the junction is performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a method for constructing a branching portion or a joining portion of a shield tunnel, and particularly to a method for constructing a branching portion or a joining portion of a deep shield tunnel in an unconsolidated ground.

The junction and junction of tunnels such as deep roads and railways do not meet the application by connecting them at right angles like sewer pipes, and a continuous connection of several hundred meters is required. It is not possible to build a connected part only by starting and reaching.
In the case of a deep-junction tunnel, since the earth pressure does not increase proportionally to the depth in the case of a consolidated ground mountain, the tunnel part is widened by applying the technique of a mountain tunnel, and the branch / confluence part is It is possible to build.
On the other hand, in the case of a deep unconsolidated ground, both soil and water pressures increase, so a technology that can be safely constructed against these is required for widening the underground.

The auxiliary method that is suitable for deep widening in the prior art is the freezing method, but the freezing method necessary for constructing a large structure of several hundreds of meters requires a large amount of heat, and the cost and construction period are also great.
In addition, freezing in unconsolidated grounds, especially viscous soils, has the problems of impacting surrounding grounds due to freezing and thawing and increasing earth pressure.

  In view of the problems of the conventional shield tunnel branching or merging part construction method, the present invention minimizes the combined use of the freezing method, and safely constructs a large depth branching / merging part at low cost. It is an object of the present invention to provide a method for constructing a branching part or a joining part of a shield tunnel that enables it.

  In order to achieve the above object, the method for constructing a branching part or a joining part of a shield tunnel according to the first invention is a method for constructing a branching part or a joining part of two shield tunnels. A temporary shield machine having a diameter smaller than the diameter of the two shield tunnels from within the two shield tunnels at the rear position of the section or the front position of the merge section, so as to cover the outer circumference of the branch section or the merge section The outer circumference of the branching section or merging section is started sequentially toward the merging section, passes through the branching section or the merging section, and is collected in one shield tunnel at the front position of the branching section or the rear position of the merging section. It is characterized by the fact that an outer shell lining is applied.

  In order to achieve the same object, the method for constructing the branching part or joining part of the shield tunnel of the second invention is a construction method of the branching part or joining part of the two shield tunnels. The temporary shield machine with a diameter smaller than the diameter of the two shield tunnels is branched from the inside of one shield tunnel at the front position of the branch section or the rear position of the merge section so as to cover the outer circumference of the branch section or the merge section. Starting sequentially toward the section or merge section, passing through the branch section or merge section, and collecting in the two shield tunnels at the rear position of the branch section or the front position of the merge section, the branch section or merge section It is characterized in that an outer shell covering that covers the outer periphery is applied.

  In this case, the angle of starting and collecting the temporary shield machine with respect to the tunnel wall surface of the shield tunnel can be set to 25 to 60 °.

  In addition, the outer shell lining bulges once in the outward direction with respect to the tunnel wall surface at the start and recovery position of the temporary shield machine, reduces the diameter at the branching or confluence portion of the shield tunnel, and against the tunnel wall surface of the shield tunnel. Can be made substantially parallel.

  In addition, adjacent outer shell linings can be overlapped and united at a branch portion or a junction portion of the shield tunnel.

According to the construction method of the branching part or the joining part of the shield tunnel of the first and second inventions, the ground can be stabilized even in the case of a deep unconsolidated ground by freezing the ground through the outer shell lining. Supporting, it is possible to safely perform underground widening work at the branching part and the merging part.
In this case, since the ground can be frozen along the outer shell lining, the frozen part can be reduced, the construction period and cost can be reduced, and the temporary shield machine can be recovered to further reduce the cost. Can do.

  Moreover, the opening area of the shield tunnel can be reduced and the strength thereof can be maintained by setting the angle of starting and collecting the temporary shield machine to the tunnel wall surface of the shield tunnel to 25 to 60 °.

  In addition, the outer shell lining bulges once in the outward direction with respect to the tunnel wall surface at the start and recovery position of the temporary shield machine, reduces the diameter at the branching or confluence portion of the shield tunnel, and against the tunnel wall surface of the shield tunnel. In order to maintain the strength of the shield tunnel by increasing the launch and recovery angle of the temporary shield machine with respect to the tunnel wall surface of the shield tunnel and reducing the opening area of the shield tunnel, The diameter of the shell lining can be reduced, the frozen part can be reduced, and the construction period and cost can be reduced.

  In addition, load resistance can be imparted to the outer shell lining by making the adjacent outer shell linings overlap and be integrated at the branching or joining portion of the shield tunnel.

  Hereinafter, an embodiment of a construction method for a branching part or a joining part of a shield tunnel according to the present invention will be described with reference to the drawings.

  1 to 5 show an embodiment of a method for constructing a branching part or a joining part of a shield tunnel according to the present invention.

  This shield tunnel construction method is to construct a branching part or a joining part of two shield tunnels 1 and two shield tunnels at a rear position of a branching part of the two shield tunnels 1 or a front position of a joining part. From inside 1, the temporary shield machine 2 having a diameter smaller than the diameter of the two shield tunnels 1 is sequentially started toward the branching part or the merging part so as to cover the outer periphery of the branching part or the merging part. The outer shell covering 3 that covers the outer periphery of the branching part or the merging part is applied by passing the merging part and collecting it in one shield tunnel 1 at the front position of the branching part or the rear position of the merging part. .

  In this case, the temporary shield machine 2 is started from within one shield tunnel 1 at the front position of the branch portion of the two shield tunnels 1 or at the rear position of the merge portion, and at the rear position of the branch portion or in front of the merge portion. It can also be made to collect in the two shield tunnels 1 at the position.

The outer shell lining 3 once bulges outward from the tunnel wall surface once at the start and recovery position of the temporary shield machine 2 and then returns to reduce the diameter at the branching or joining portion of the shield tunnel 1. 1 is substantially parallel to the wall surface of the tunnel.
As a result, the start and recovery angles of the temporary shield machine 2 with respect to the tunnel wall surface of the shield tunnel 1 are set to 25 to 60 °.
Further, at the branching part or the joining part of the shield tunnel 1, the adjacent outer shell linings 3 are provided so as to overlap with each other.

  By the way, the segments that constitute the shield tunnel 1 of the branching or joining part of the two shield tunnels 1 and the starting part and the recovery part of the temporary shield machine 2 are segments that constitute other permanent parts as required. Compared to, a weaker segment can be used.

  Next, the construction method of the present embodiment will be described by taking a branch lamp of a road shield tunnel as an example.

First, as shown in FIG. 1, the main shield tunnel 1a and the branch shield tunnel 1b are completed to a predetermined position.
From the main line shield tunnel 1a and the branch line shield tunnel 1b, the temporary shield machine 2 constructs as many temporary block shields 4 as necessary for excavation between the main lines, and the outside of the main line shield tunnel 1a and the branch line shield tunnel 1b in the longitudinal direction. A shell lining (roof) 3 is formed.

As shown in FIG. 2, the temporary block shield 4 starts obliquely from the main shield tunnel 1a and the branch shield tunnel 1b, reaches obliquely, and is collected and reused.
A plurality of temporary block shields 4 are required for the outer shell lining 3 to form a roof. However, it is difficult to reinforce the segments of the shield tunnel 1 if openings for starting and reaching are installed at the same location.
Therefore, the starting and reaching positions are shifted in the longitudinal direction and the circumferential direction, and the necessary number of temporary block shields 4 is ensured after ensuring the opening interval that can be reinforced.

  The temporary shield machine 2 starts obliquely from the main shield tunnel 1a or the branch shield tunnel 1b, and then performs a three-dimensional sharp curve excavation to reach the required position on the outer shell lining 3 with a minimum excavation distance. Further, as shown in FIG. 3, as soon as the excavation of the roof section to which the outer shell lining 3 is applied is completed, it is collected in the main shield tunnel 1a by a sharp curve construction in the same manner as the start.

  As shown in FIG. 4, the temporary block shield 4 uses a segment 6 having a substantially circular cross section made of a machinable material having a steel shell 5 having a bowl-shaped cross section. In the roof section, the subsequent temporary block shield 4 is excavated while cutting the cutable material portion of the preceding temporary shield segment 6.

After the construction of the outer shell lining 3 by the temporary block shield 4 is completed, the segment surface of the temporary block shield 4 is partially frozen to counter a deep water pressure. The retaining wall 7 is also constructed by freezing the wife 7 at the end of the outer shell lining 3.
The joint between the temporary block shield 4 and the main branch shield tunnel 1 uses the auxiliary method of the high-pressure injection system to connect the temporary block shield 4 and the segment of the shield tunnel 1 together.

  In this case, as shown in FIG. 4, the segments of the temporary block shield 4 are connected to each other by a PC steel wire 8 and are tightly coupled within the segment of the shield tunnel 1 as shown in FIG. Can be granted.

The segment is removed from the upper part of the shield tunnel 1 in the outer shell lining 3, and the soil between the outer shell lining 3 and the shield tunnel 1 is excavated and carried out.
In this case, as shown in FIG. 5, after the upper half is excavated according to the external pressure, the intermediate strut 9 is provided inside the outer shell covering 3 to excavate the lower half.

After the excavation is completed, the branch structure 10 is built in the outer shell lining 3, and an outer waterproofing work is performed from the outer shell lining 3.
Then, the space between the outer shell lining 3 and the structure 10 is filled with the backfilled soil subjected to high fluidization treatment.
The water stop freezing is completed and the finishing work inside the structure 10 is performed.

Thus, the method of constructing the junction or junction of the shield tunnel according to the present embodiment stably supports the ground even in the case of a deep unconsolidated ground by freezing the ground through the outer shell lining, and branches. The underground widening work can be safely performed at the section and junction.
In this case, since the ground can be frozen along the outer shell lining 3, the freezing portion is reduced, the construction period and cost are reduced, and the temporary shield machine 2 is recovered to further reduce the cost. can do.

  Moreover, the opening area of the shield tunnel 1 can be made small and the intensity | strength can be maintained by setting the angle of starting and collection | recovery of the temporary shield machine 2 with respect to the tunnel wall surface of the shield tunnel 1 to 25-60 degrees.

  Then, the outer shell lining 3 bulges once in the outward direction with respect to the tunnel wall surface at the start and recovery position of the temporary shield machine 2 and is reduced in diameter at the branching or joining portion of the shield tunnel 1. By making it substantially parallel to the tunnel wall surface, the launch and recovery angle of the temporary shield machine 2 with respect to the tunnel wall surface of the shield tunnel 1 is increased, the opening area of the shield tunnel 1 is reduced, and the strength is maintained, The diameter of most of the outer shell cover 3 can be reduced, the frozen portion can be reduced, and the construction period and cost can be reduced.

  Furthermore, load resistance can be imparted to the outer shell covering 3 by making the adjacent outer shell coverings 3 overlap and be integrated at the branching or joining portion of the shield tunnel 1.

  As mentioned above, although the construction method of the branching part or merging part of the shield tunnel of the present invention has been described based on the example, the present invention is not limited to the configuration described in the above example, but described in the example. The configurations can be changed as appropriate without departing from the spirit of the invention, for example, by appropriately combining the configurations.

  The method of constructing the junction or junction of the shield tunnel of the present invention has the characteristics of minimizing the combined use of the freezing method and enabling the construction of large-scale junctions and junctions at a low cost. Therefore, for example, it can be suitably used for the construction of a branch / merging portion of a shield tunnel of a deep unconsolidated ground.

It is a 1st process figure which shows one Example of the construction method of the branch part or confluence | merging part of the shield tunnel of this invention. It is a longitudinal cross-sectional view which shows the said 2nd process. It is a perspective view which shows the said 3rd process. It is a cross-sectional view showing the fourth step. It is a cross-sectional view showing the fifth step.

Explanation of symbols

1 Shield tunnel 2 Temporary shield machine 3 Outer shell lining (roof)
4 Temporary block shield 5 Steel shell 6 Segment 7 Wife 8 PC steel wire 9 Intermediate strut 10 Structure

Claims (5)

  A method for constructing a branching part or a joining part of two shield tunnels, wherein the two shield tunnels are located within the two shield tunnels at the rear position of the two shield tunnels or at the front part of the joining part. The temporary shield machine having a diameter smaller than the diameter is sequentially started toward the branching part or the joining part so as to cover the outer periphery of the branching part or the joining part, and is passed through the branching part or the joining part. By collecting in one shield tunnel at the rear position of the junction, an outer shell covering is provided to cover the outer periphery of the junction or junction. Construction method.   A method of constructing a branching part or a joining part of two shield tunnels, wherein two shield tunnels are arranged from one shield tunnel at a front position of a branching part of two shield tunnels or a rear position of a joining part. A temporary shield machine having a diameter smaller than the diameter is sequentially started toward the branching part or the merging part so as to cover the outer periphery of the branching part or the merging part, and is passed through the branching part or the merging part. By collecting in the two shield tunnels at the front position of the junction, an outer shell covering that covers the outer periphery of the junction or junction is applied. Construction method.   3. A method for constructing a branching part or a joining part of a shield tunnel according to claim 1 or 2, wherein the angle of starting and collecting the temporary shield machine with respect to the tunnel wall surface of the shield tunnel is set to 25 to 60 degrees.   The outer shell lining bulges once in the outward direction with respect to the tunnel wall surface at the start and recovery position of the temporary shield machine, shrinks in diameter at the branching or joining part of the shield tunnel, and is approximately the tunnel wall surface of the shield tunnel. 4. The method for constructing a branching part or a joining part of a shield tunnel according to claim 1, 2 or 3, wherein the parallel part is parallel.   5. The shield tunnel branch or merge portion according to claim 1, 2, 3 or 4, wherein the outer shell linings overlap and are integrated in the branch or merge portion of the shield tunnel. Construction method.

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