JP6653497B2 - Construction method of traffic line shield tunnel and large section underground space - Google Patents

Description

  The present invention relates to a traffic line shield tunnel and a method for constructing a large-section underground space.

  2. Description of the Related Art Conventionally, in a large-section road tunnel or the like, a large-section underground space is constructed at a junction of a main shield tunnel and a ramp shield tunnel, each of which is a permanent shield tunnel. As a method for constructing such a large underground space, for example, as shown in Patent Document 1, when constructing an underground cavity forming a large underground space by excavating underground, A method is known in which a plurality of roof shield tunnels are arranged on the outside in advance at predetermined intervals, thereby constructing a shield roof precedent surrounding a planned excavation position by the roof shield tunnels.

  Further, in Patent Document 1, when constructing an underground space, a plurality of outer shell shield tunnels are constructed outside the planned excavation position of the underground space to construct a shield roof precedent surrounding the planned excavation position. A method is described in which a plurality of outer shell shield tunnels are started by using an underground starting base provided in advance along the outer periphery of an existing tunnel.

  When constructing a large cross-section underground space such as the junction of road tunnels, the outer shell shield tunneling machine that makes the outer shell lining is excavated from the underground starting base. Therefore, it is necessary to arrange the outer shell shield machine in the underground starting base. Usually, the outer shell shield machine is arranged in such a manner that it is transported through the previously constructed main line shield tunnel, and is inserted into the underground starting base through the input opening provided in the main line shield tunnel. In addition, the main line shield tunnel is used to carry in and carry out excavated earth and sand generated during the construction of the outer shield tunnel.

Japanese Patent No. 4958035

However, the conventional method of constructing a large underground space does not only use the main line shield tunnel to carry in the outer shell shield machine, but also removes excavated earth and sand during construction and carries in materials such as segments. You are using a tunnel. For this reason, when the main line shield tunnel itself is under construction, there is a problem in that carrying-in / out operations relating to these outer shell shield tunnels are restricted.
In addition, the opening of the main line shield tunnel to the underground starting base requires the movement of the outer shell shield machine and requires large-scale reinforcement, so there was room for improvement in that respect.

  The present invention has been made in view of the above-described problems.By performing the construction of the outer shell shield tunnel without interfering with other construction, the construction period can be shortened, and the underground starting base can be further improved. It is an object of the present invention to provide a traffic line shield tunnel and a method of constructing a large cross-section underground space in which reinforcement can be suppressed to a small scale.

  In order to achieve the above object, the traffic line shield tunnel according to the present invention, when constructing an underground widening portion that forms a branching junction of the main line shield tunnel and the ramp shield tunnel, a planned excavation position of the underground widening portion On the outside of the shell, a plurality of outer shell shield tunnels are preliminarily excavated by a shell shield machine, and are constructed in a state of being arranged in the circumferential direction of the tunnel. A traffic line tunnel to be used when constructing a body, constructing a large section underground space by excavating the inside of the outer shell lining body, starting from the lamp shield tunnel, It is dug toward the underground starting base constructed in the circumferential direction at a predetermined position, and connects the lamp shield tunnel and the underground starting base. Both are characterized in that the outer shell shield machine has an inner air-sectional passable.

  Further, the construction method of the large section underground space according to the present invention, when constructing an underground widening portion forming a branching junction of the main line shield tunnel and the ramp shield tunnel, outside the underground widening portion of the excavation scheduled position By constructing a plurality of outer shield tunnels in advance in a state arranged in the circumferential direction of the tunnel by excavating the outer shield machine, the outer shell lining body surrounding the planned excavation position by the outer shield tunnels Constructing a large section underground space excavating the inside of the outer shell lining body, a step of reaching the predetermined position of the lamp shield tunnel, from the lamp shield tunnel to the main line shield tunnel Constructing a traffic line shield tunnel toward an underground starting base to be constructed in the circumferential direction; After arriving, the outer shell shield machine is transported in the traffic line shield tunnel and moved from the ramp shield tunnel to the underground starting base, and the outer shell shielding machine is moved to a predetermined starting position of the underground starting base. And a step of digging the outer shell shield machine to provide an outer shell shield tunnel.

In the present invention, a traffic line shield machine is dug using a ramp shield tunnel that has reached a predetermined position in advance, and a traffic line shield tunnel that reaches an underground starting base provided at a predetermined position in advance is constructed. In other words, the ramp shield tunnel and the underground starting base are connected by the traffic line shield tunnel. Can be transported. That is, it is possible to transport the outer shell shield machine into the underground starting base without using the main line shield tunnel. In addition, the traffic line shield tunnel can be used as a material carrying-out path required for carrying out earth and sand during construction of the outer shell shield tunnel and construction.
As described above, by providing the traffic line shield tunnel, other work that interferes with the excavation work of the main line shield tunnel can be eliminated. Therefore, the construction of the outer shell tunnel and the construction of the main line shield tunnel can be performed efficiently in parallel, and the construction period of the entire construction can be shortened. Therefore, even if the main line shield tunnel arrives at the planned underground widening section later than the ramp shield tunnel, the traffic line tunnel can be constructed from the ramp shield tunnel that has reached the predetermined position first. The construction of the outer shield tunnel can be started, and the construction period can be significantly reduced.

In addition, in the present invention, since the traffic line shield tunnel is directly connected to the underground starting base, it is not necessary to provide a new reaching pit for the traffic line shield tunnel to reach, and the construction can be performed efficiently. it can.
Further, according to the present invention, a heavy outer shell shield machine can be carried into the underground starting base using the traffic line shield tunnel. Therefore, there is no need to use a loading opening that connects the inside of the main line shield tunnel and the underground launching station to carry the outer shell shield machine, and the reinforcement of the loading opening at the underground launching base can be reduced on a small scale. Can be suppressed.

  In the construction method for a large-section underground space according to the present invention, it is preferable that the traffic line shield tunnel is configured as one of the plurality of outer shell shield tunnels.

  In this case, the constructed flow shield tunnel functions as one of the outer shield tunnels, so after the transport of the outer shield machine and the function as the flow line at the time of construction of the outer shield tunnel are completed, There is no need to remove the traffic line tunnel, and efficient construction can be performed.

  Further, in the method for constructing a large cross-section underground space according to the present invention, the outer shell shield machine transported in the traffic line shield tunnel may be configured such that the excavation cutter is directed toward the starting side of the traffic line shield tunnel. It is preferable to be moved backward toward the starting base.

  In this case, the outer shell shield machine transported in the traffic line shield tunnel is moved along the circumferential direction of the underground starting base without changing the direction during transport, and the predetermined starting face Position. In other words, when moving the outer shell shield machine, it is not necessary to change the direction of the outer shell shield machine, so that the construction period can be shortened.

  Further, the construction method of the large section underground space according to the present invention, passing the plurality of outer shell shield machines in the traffic line shield tunnel, the plurality of outer shell shield machines arrived at the underground starting base, It is preferable that the underground starting bases are sequentially moved along the circumferential direction and are continuously arranged.

  In this case, a plurality of outer shell shield machines can be continuously moved to the underground starting base using the traffic line shield tunnel, and a plurality of outer shell shielding machines that arrive at the underground starting base are sequentially moved. By moving the outer shell shield machines in the circumferential direction, the plurality of outer shell shield machines can be efficiently arranged at predetermined starting positions of the underground starting base.

  According to the construction method of the traffic line shield tunnel and the large section underground space of the present invention, the ramp shield tunnel and the underground starting base are connected by the traffic line shield tunnel, and this flow line shield tunnel is used when constructing the outer shell shield tunnel. Transportation can be used as a flow line for construction, and construction of the outer shell shield tunnel can be performed without interfering with other construction, shortening the construction period and reinforcing the underground starting base Can be kept small.

It is a perspective view which shows the construction state of the underground widening part by embodiment of this invention. It is a perspective view which shows the whole outline of the construction method of the underground widening part using a traffic line shield tunnel. It is a top view which shows the whole outline of the construction method of the underground widening part shown in FIG. It is the perspective view which showed the state which conveys in a traffic line shield tunnel toward an underground starting base. FIG. 4 is a front view of the underground starting base as viewed from the direction of a tunnel axis, taken along the line AA shown in FIG. 3.

  Hereinafter, a method of constructing a traffic line shield tunnel and a large underground space according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 to 3, the method of constructing the traffic line shield tunnel and the large underground space according to the present embodiment uses a ramp for the main line shield tunnel 11 previously constructed in the ground, for example, in a road tunnel. It is applied to the construction for constructing the underground widening portion 1 at the place where the shield tunnel 12 joins and branches.

  This underground widening portion 1 has a plurality of outer shell shield tunnels 13, 13,... On the outside of the main line shield tunnel 11 and the lamp shield tunnel 12, with a central axis having a direction parallel to the tunnel axis direction X of the main line shield tunnel 11. By constructing in a state of being arranged in the circumferential direction E, the outer shell lining body 1A surrounding the planned excavation position by the outer shell shield tunnel 13 is constructed, and the outer shell lining body 1 surrounding the main line shield tunnel 11 and the lamp shield tunnel 12 is further constructed. It is constructed by excavating the inside of the shell lining body 1A. The outer shell shield tunnel 13 is constructed by excavating an outer shell shield machine 14. In the present embodiment, the main line shield tunnel 11 and the lamp shield tunnel 12 are constructed by a known shield method.

  In the present embodiment, the ramp shield tunnel 12 is first reached to a predetermined arrival position in the underground widening section 1 in the planned excavation area, and a part of the ramp shield tunnel 12 is widened to form the traffic line shield starting base 12A. At the same time, the underground starting base 15 for starting the outer shell shield machine 14 at a predetermined position of the main line shield tunnel 11 digging toward the lamp shield tunnel 12 side is installed. Then, a traffic line shield machine (not shown) is started from the traffic line shield starting base 12A to construct a traffic line shield tunnel 3, and the underground starting base 15 is used for the outer shell shield machine using the traffic line shield tunnel 3. 14 is carried in and installed.

As shown in FIGS. 4 and 5, the outer shell shield machine 14 is excavated with the underground starting base 15 formed in a ring shape along the circumferential direction E outside the main line shield tunnel 11 as a starting part.
As shown in FIG. 3, the plurality of outer shield tunnels 13 cause the outer shield machine 14 to dig toward an underground reaching portion set at a predetermined position on the outer periphery of the main line shield tunnel 11 and the lamp shield tunnel 12. It is constructed by doing.

The underground starting base 15 is constructed by excavating the ground after freezing the ground by a freezing method or the like, and assembling concrete segments, steel shell segments, and the like in parallel. The starting base 15 is set to a size that allows the outer shell shield machine 14 to start (see FIGS. 4 and 5). The underground starting base 15 may be constructed using a circumferential shield excavator.
In the underground starting base 15, a plurality of starting facets 15 a forming a starting portion of the outer shell shield machine 14 have outer walls formed by the segments 10 A at the time of construction, respectively. Similarly, the work is performed using a material such as concrete containing carbon fiber, which can be cut by a cutting cutter. It is also possible to use a segment 10A in which a starting face 15a made of a material that can be cut by a cutting cutter is incorporated in advance.
The starting portion in the case of using the steel shell segment may be constructed of a material that can be cut in the same manner, or may be a structure that can be removed immediately before starting.

  Here, excavation of the underground starting base 15 is performed by a conventional method using a backhoe or the like, and a special machine or the like is used to assemble the segments. The underground starting base 15 can also be constructed by excavating a circumferential shield excavator in the circumferential direction. When such a circumferential shield excavator is used, a cutter is provided on the excavation surface, the tunnel is excavated so as to draw a constant curve, and a segment assembled in a cylindrical shape behind the circumferential shield excavator. 10A are connected in the tunnel excavation direction, and the circumferential shield tunnel 10 is sequentially extended and constructed.

As shown in FIGS. 2 and 3, the traffic line shield tunnel 3 is configured such that a traffic line shield machine (not shown) is arranged in a traffic line shield starting base 12 </ b> A constructed in the ramp shield tunnel 12. It is constructed by arriving at one of the plurality of starting face surfaces 15a. As a result, the lamp shield tunnel 12 and the underground starting base 15 are in communication with each other via the traffic line shield tunnel 3. Further, the inner diameter of the traffic line shield tunnel 3 has a dimension having an inner space section through which at least the outer shell shield machine 14 can pass from the lamp shield tunnel 12 side toward the underground starting base 15.
The traffic line shield tunnel 3 is configured as one of a plurality of outer shell shield tunnels 13, 13,.

Next, a method of constructing the underground widening portion 1 described above will be specifically described with reference to the drawings.
As shown in FIGS. 2 and 3, the method of constructing the underground widening portion 1 of the present embodiment includes a step of causing the lamp shield tunnel 12 to reach a predetermined arrival position P1 and a step of moving the lamp shield tunnel 12 from the main shield tunnel 11. A step of constructing the traffic line shield tunnel 3 toward the underground starting base 15 to be constructed in the circumferential direction, and after the flow line shield tunnel 3 reaches the underground starting base 15, Transporting the outer shell shield machine 14 and moving it from the lamp shield tunnel 12 to the underground starting station 15, and arranging the outer shield machine 14 at a predetermined starting position of the underground starting station 15; And providing a shell shield tunnel 13 by excavating the shell.

As a concrete method of constructing the underground widening section 1, a ramp shield tunnel 12 that branches and joins with the main line shield tunnel 11 is constructed at an excavation position of the underground widening section 1.
First, a traffic line shield starting base 12A is constructed in a part of the ramp shield tunnel 12. The traffic line shield starting base 12A is provided at a position opposite to the main line shield tunnel 11 that branches and joins. 2 and 3, a lamp shield machine 12B excavating the lamp shield tunnel 12 is shown. After the lamp shield machine 12B arrives at the lamp shield tunnel 12, the lamp shield machine 12B leaves the skin plate and the traffic line shield. It is disassembled before or after the construction of the starting base 12A and is carried out toward the starting side of the lamp shield tunnel 12. That is, when the traffic line shield starting base 12A is constructed, the lamp shield machine 12B is in a state of being carried out of the mine.

Next, at a predetermined position in the ramp shield tunnel 12, a traffic line shield starting base 12A having a predetermined size capable of starting the traffic line shield machine is constructed. Prior to the construction of the traffic flow shield starting base 12A, the ground around the construction area of the traffic flow shield launching base 12A is excavated after the ground improvement part is constructed by a chemical injection method or a freezing method.
Thereafter, a flow line shield machine (not shown) is passed through the ramp shield tunnel 12, the transported flow line shield machine is assembled in the flow line shield starting base 12A, and preparation for starting is performed.

  In parallel with the construction of the traffic line shield starting base 12A, the outer shell is formed around the main line shield tunnel 11 by the above-mentioned method at an appropriate timing when the main line shield tunnel 11 has passed the planned construction position of the underground starting base 15. An underground starting base 15 for starting the shield machine 14 is provided.

The underground starting base 15 only needs to be constructed before the arrival of the traffic line shield tunnel 3, and is not constructed in parallel with the above-described traffic line shielding base 12A. It may be constructed inside.
The starting face 15a corresponding to the starting portion of the outer shell shield machine 14 at the underground starting base 15 is constructed of a material that can be cut with a cutter in the same manner as a general shield method.

  Next, the traffic line shield machine installed at the traffic line shield starting base 12A is excavated from the ramp shield tunnel 12 toward the underground starting base 15 to reach one starting face 15a of the underground starting base 15. . Then, the arriving traffic line shield machine is dismantled in the underground starting base 15 and carried out using the main line shield tunnel 11. As a result, the lamp shield tunnel 12 and the underground starting base 15 are connected via the traffic line shield tunnel 3.

  Next, a plurality of outer shield tunnels 13 are constructed by arranging and excavating the outer shield machine 14 at the underground starting base 15. The plurality of outer shield tunnels 13 may be excavated simultaneously or in parallel with the plurality of outer shield machines 14, or may be constructed one by one. The outer shield machine 14 arranged on a predetermined starting face 15a in the underground starting base 15 is installed by being transported in the ramp shield tunnel 12 and the traffic line shield tunnel 3. In other words, the assembled shell shield machine 14 is loaded from the wellhead side of the ramp shield tunnel 12 with its rear end 14a facing forward in the transport direction, passes through the flow line shield starting base 12A, and further moves through the flow line. It is transported in the shield tunnel 3 and sent into the underground starting base 15. Here, the arrow F shown in FIGS. 2 and 3 and the like indicates the transport direction of the outer shell shield machine 14. At this time, the outer shell shield machine 14 moved inside the traffic line shield tunnel 3 is moved backward toward the underground starting base 15 with the excavating cutter facing the start side of the traffic line shield tunnel 3.

Then, as shown in FIG. 5, the outer shell shield machine 14 sent into the underground starting base 15 is moved along the circumferential direction E and arranged at a position of the predetermined starting face 15a.
Note that the plurality of outer shell shield machines 14 arriving at the underground starting base 15 may be sequentially moved along the circumferential direction E of the underground starting base 15 so as to be continuously arranged.

  Next, as shown in FIGS. 2 and 4, a plurality of outer shell shield tunnels 13 are constructed by excavating one or more outer shell shield machines 14 installed at the underground starting base 15 one by one or simultaneously. The excavated earth and sand is sent into the traffic line shield tunnel 3 via the underground launching base 15 and carried out to the outside, and materials such as segments necessary for excavation are also removed from inside the traffic line shield tunnel 3. Through the outer shell shield tunnel 13.

The removal of the excavated earth and sand from the outer shield tunnel 13 and the transport of the materials necessary for the excavation are not limited to the use of the traffic shield tunnel 3, and the main shield tunnel 11 may be used. Shield tunnels 3 and 11 may be used.
As described above, since the traffic line shield tunnel 3 is constructed in the same tunnel shape as one of the outer shell shield tunnels 13, it functions as an outer shell shield tunnel.

  Thereafter, as shown in FIG. 3, when all the outer shield machines 14 reach the predetermined underground reach, the outer shield machine 14 is dismantled with the skin plate left at the underground reach and recovered. I do. Then, the outer shell shield tunnels 13 adjacent to each other in the circumferential direction E are ground-improved by a freezing method, a chemical liquid injection method, or the like, and then connected as a cut-out structure to achieve integration. Thus, an outer shell lining body 1A having a supporting function and a water stopping function is constructed. Further, a wall is constructed inside the outer shell lining body 1A near the underground reaching portion. The starting base 12A of the traffic line shield tunnel 3 is used as a part of the wall.

  Next, the inside surrounded by the outer shell lining body 1A is excavated. At this time, the segments of the main line shield tunnel 11 and the lamp shield tunnel 12 located inside the outer shell lining body 1A are dismantled and removed to form the underground widened portion 1.

Next, the operation of the above-described method of constructing the traffic-line shield tunnel and the large section underground space will be described in detail with reference to the drawings.
As shown in FIGS. 2 and 3, in the present embodiment, the traffic line shield machine is dug using the ramp shield tunnel 12 that has reached the predetermined position in advance, and the underground vehicle provided at the predetermined position in advance is used. A traffic line shield tunnel 3 reaching the base 15 is constructed. That is, since the lamp shield tunnel 12 and the underground starting base 15 are connected by the traffic line shield tunnel 3, a plurality of outer shell shield machines 14 are connected to the ground from the lamp shield tunnel 12 side using the traffic line shield tunnel 3. It can be transported into the middle starting base 15. That is, it is possible to transport the outer shell shield machine 14 into the underground starting base 15 without using the main line shield tunnel 11. In addition, the traffic line shield tunnel 3 can be used also as a material carrying-out path required for carrying out earth and sand during construction of the outer shell shield tunnel 13 and construction.

By providing the traffic line shield tunnel 3 in this way, other work that interferes with the excavation work of the main line shield tunnel 11 can be eliminated. Therefore, both the construction of the outer shell shield tunnel 13 and the construction of the main line shield tunnel 11 can be performed efficiently in parallel, and the construction period of the whole construction can be shortened.
Therefore, even when the main line shield tunnel 11 arrives at the scheduled construction position of the underground widening section 1 later than the lamp shield tunnel 12, the traffic line shield tunnel 3 is moved from the lamp shield tunnel 12 which has reached the predetermined position first. The construction of the outer shell shield tunnel 13 can be started, and the construction period can be significantly shortened.

  Further, in the present embodiment, the heavy outer shell shield machine 14 can be carried into the underground starting base 15 using the traffic line shield tunnel 3. Therefore, as shown in FIG. 5, there is no need to carry in the outer shell shield machine 14 using the input opening 15A that connects the inside of the main line shield tunnel 11 and the inside of the underground starting base 15, and the underground starting base is not required. The reinforcement of the opening 15 </ b> A at 15 can be reduced to a small scale.

  Further, in the present embodiment, since the traffic line shield tunnel 3 is directly connected to the underground starting base 15, it is not necessary to provide a new arrival pit for the traffic line shield tunnel 3 to reach, and it is efficient. Construction can be performed.

  Further, in the present embodiment, the constructed flow line shield tunnel 3 functions as one of the outer shell shield tunnels 13, so that it is used as a flow line when transporting the outer shell shield machine 14 or constructing the outer shell shield tunnel 13. After the function is completed, there is no need to remove the traffic line shield tunnel 3, and efficient construction can be performed.

  Further, in the present embodiment, the outer shell shield machine 14 transported in the traffic line shield tunnel 3 is moved along the circumferential direction E of the underground starting base 15 without changing the direction during the transport. , Can be arranged at the position of the predetermined starting face 15a. In other words, when moving the outer shell shield machine 14, it is not necessary to change the direction of the outer shell shield machine 14, so that it is possible to shorten the construction period.

  Furthermore, in the present embodiment, a plurality of outer shell shield machines 14 can be continuously moved to the underground starting base 15 using the traffic line shield tunnel 3, and furthermore, arrive at the underground starting base 15. By sequentially moving the plurality of outer shell shield machines 14 in the circumferential direction E, the plurality of outer shell shield machines 14 can be efficiently arranged at predetermined starting positions of the underground starting base 15.

  As described above, in the method for constructing the traffic shield tunnel and the large underground space according to the present embodiment, the ramp shield tunnel 12 and the underground starting base 15 are connected by the traffic shield tunnel 3, and the traffic shield tunnel 3 Can be used as a flow line for construction during transportation of the outer shell shield tunnel 13, and the construction of the outer shell shield tunnel 13 is performed without interfering with other construction, thereby shortening the construction period. And the reinforcement of the underground starting base 15 can be suppressed to a small scale.

The embodiments of the traffic line shield tunnel and the method of constructing the large cross-section underground space according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and may be appropriately performed without departing from the gist thereof. Can be changed.
For example, in the present embodiment, the lamp shield tunnel 12 precedes, and the main line shield tunnel 11 reaches the branch junction from the lamp shield tunnel 12 later. However, the construction is limited to such a construction. Never. In other words, even when the ramp shield tunnel 12 reaches the branching junction with the main line shield tunnel 11 constructed earlier, the traffic line shield tunnel 3 is constructed from the ramp shield tunnel 12 to start underground. A construction method of connecting to the base 15 and transporting the outer shell shield machine 14 and the like using the traffic line shield tunnel 3 may be used.

  In addition, the configuration such as the position, the inner diameter, and the number of the traffic line shield tunnel 3 can be appropriately set according to the outer diameter of the outer shell shield machine 14, the position of the lamp shield tunnel 12, and the like. For example, in the present embodiment, a construction method is provided in which one flow line shield starting base 12A is provided in the lamp shield tunnel 12 and one flow line shield tunnel 3 which starts from the flow line shield starting base 12A. , But is not limited to this. If the arrival of the main line shield tunnel 11 is greatly delayed, a plurality of ramp shield tunnels 12 or a large traffic line shield starting base 12A is provided, and the plural traffic line shield tunnels 3 are connected to the underground starting base 15. By connecting and transporting the outer shell shield machine 14 to the underground starting base 15 using the plurality of traffic line shield tunnels 3 and constructing the outer shell shield tunnel 13, it is possible to shorten the construction period. is there.

  Then, as a method of constructing the underground starting base 15, a method of assembling segments by excavating the surroundings by a conventional method and constructing a circumferential shield tunnel 10 by excavating a circumferential shield excavator having a rectangular cross section is constructed as an underground starting base 15. However, the method is not limited to the construction using a shield excavator, and the construction may be performed by another method such as an enlarged shield.

  Furthermore, although the present embodiment is an application example in the case of constructing a road tunnel having a large cross section, it is widely applied to the construction of tunnels of various scales, applications, and forms having a large underground space as described above. It can be applied, and various design changes can be made according to the scale and form of the large section underground space in the tunnel to be constructed and in consideration of various conditions such as the surrounding environment.

  In addition, it is possible to appropriately replace the components in the above-described embodiment with known components without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Underground widening part 1A Outer shell lining body 3 Traffic line shield tunnel 10 Circumferential shield tunnel 11 Main line shield tunnel 12 Lamp shield tunnel 12A Traffic line shield launching base 13 Outer shell shield tunnel 14 Outer shell shielding machine 15 Underground launching base 15A Input opening 15a Start face 10A Segment E Circumferential direction X Tunnel axial direction

Claims (5)

When constructing an underground widening section that forms a branching junction between the main line shield tunnel and the lamp shield tunnel, a plurality of outer shell shield tunnels are previously set outside the planned excavation position of the underground widening section by an outer shell shield machine. By constructing in a state of being arranged in the circumferential direction of the tunnel by excavating, a shell lining surrounding the planned excavation position is constructed by the shell shield tunnel, and the inside of the shell lining is excavated. A traffic shield tunnel used when constructing a large section underground space,
Starting from the lamp shield tunnel, excavated toward an underground starting base constructed in the circumferential direction at a predetermined position of the main line shield tunnel,
A traffic line shield tunnel connecting the ramp shield tunnel and the underground starting base and having an inner space section through which the outer shell shield machine can pass. When constructing an underground widening section that forms a branching junction between the main line shield tunnel and the lamp shield tunnel, a plurality of outer shell shield tunnels are previously set outside the planned excavation position of the underground widening section by an outer shell shield machine. By constructing in a state of being arranged in the circumferential direction of the tunnel by excavating, an outer shell lining body surrounding the planned excavation position is constructed by the outer shell shield tunnel, and the inside of the outer shell lining body is excavated. It is a construction method of a large section underground space,
Causing the lamp shield tunnel to reach a predetermined destination position;
A step of constructing a traffic line shield tunnel from the ramp shield tunnel to an underground starting base constructed in the circumferential direction of the main line shield tunnel,
After the traffic line shield tunnel reaches the underground starting base, the outer shell shield machine is transported in the traffic line shield tunnel and moved from the lamp shield tunnel to the underground starting base, and the underground starting is performed. Arranging the outer shell shield machine at a predetermined starting position of a base;
Excavating the outer shell shield machine to provide an outer shell shield tunnel;
Construction method of underground space with large cross section characterized by having.   The method according to claim 2, wherein the traffic line shield tunnel is configured as one of the plurality of outer shell shield tunnels.   The outer shell shield machine conveyed in the traffic line shield tunnel is moved backward toward the underground starting base with the excavating cutter facing the start side of the traffic line shield tunnel. The method for constructing a large section underground space according to claim 2. Passing a plurality of the outer shell shield machines in the traffic line shield tunnel,
The plurality of outer shell shield machines arriving at the underground starting station are sequentially moved along the circumferential direction of the underground starting station and are continuously arranged. The method for constructing a large section underground space according to any one of the preceding claims.

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