JP2017128898A - Shield machine transfer system and large section tunnel construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an outer shell shield machine to be transferred to a predetermined start position in an underground start base with a simple structure and thereby improving working efficiency and shortening a construction period.SOLUTION: A shield machine transfer system comprises: a guide rail 5 which is used for constructing outer shell tunnels 2 with an outer shell shield machine 10 started from a portion of a main tunnel 1, is installed in an underground start base 3 constructed in a ring shape along a peripheral section of the main tunnel 1, is extended in a circumferential direction of the main tunnel in the underground start base 3, and guides the outer shield machine 10 along the circumferential direction of the main tunnel; a telescopic jack 42 which is connected to one edge of the outer shell shield machine 10 in the circumferential direction of the main tunnel and can be extended or contracted in the circumferential direction of the main tunnel; a clump 43 which is detachably supported by the guide rail 5 and receives reaction force of the telescopic jack 42 in a state of being supported by the guide rail 5; and a storage frame 41 which stores the outer shell shield machine 10 and has a slide section sliding along the guide rail 5.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a shield machine moving system and a method for constructing a large section tunnel.

Conventionally, as a method of constructing the underground widening part that excavates the ground, a plurality of outer shell shield tunnels are arranged outside the planned construction position of the underground cavity at a predetermined interval to surround the planned construction position in the large cross-sectional space. By constructing a shield roof tip receiver, excavating the inside of this shield roof tip receiver with a large section shield tunnel, and further excavating between the large section shield tunnel and the shield roof tip receiver, The construction method to build is known.
In the method of constructing the underground widened portion using such a shield roof tip receiving construction, the cylindrical lining wall including the necessary space of the underground widened portion is constituted by, for example, an outer shell shield tunnel having an outer diameter of about 4 m. A plurality of outer shield tunnels are started from shield tunnels that are constructed in advance (see, for example, Patent Document 1).

  In Patent Document 1, when constructing a branching junction between the main shield tunnel and the lamp shield tunnel, the lamp shield tunnel is advanced ahead of the main shield tunnel, and the roof shield machine is started near the tip of the lamp shield tunnel. A method of constructing a shield roof tip receiving work that surrounds a branch junction by constructing a number of roof shield tunnels (outer shell shield tunnels) in a state of being closely arranged along the contour of the junction outside the branch junction It is disclosed.

Japanese Patent No. 4803428

However, the conventional large-section tunnel construction method described above has the following problems.
That is, the outer shell shield used in the conventional large-section shield has a plurality of units installed at predetermined positions in the circumferential direction of the underground start base. However, even if the outer shell shield is a shield excavator having an outer diameter of about 4 m, for example, it has a weight of nearly 100 t. And since the underground launch base mentioned above has a limited work space, it is also considered that the shield machine and the launch stand are combined together to form a unit. Further, the weight of the integral unit is, for example, 150 t. It is getting bigger. Therefore, it is very complicated and time consuming to move and install such a heavy outer shell shield machine in a ground start base with limited space to a predetermined start position. become.

  The present invention has been made in view of the above-described problems, and by moving the outer shell shield machine to a predetermined start position in the underground start base with a simple structure, the construction efficiency is improved and the construction period is shortened. It is an object of the present invention to provide a shield machine moving system capable of achieving the above and a method for constructing a large section tunnel.

  In order to achieve the above object, in the shield machine moving system according to the present invention, the main machine is used when excavating the ground and starting the outer shield machine from a part of the main tunnel to construct the outer shell tunnel. A shield machine moving system provided in an underground start base constructed in a ring shape along the outer periphery of the tunnel, and extending to the underground start base in the tunnel circumferential direction, and tunneling the outer shell shield machine A guide guide rail that guides in the circumferential direction, a telescopic device that is connected to one end in the tunnel circumferential direction of the outer shell shield machine, and that can expand and contract along the tunnel circumferential direction, and is detachably supported with respect to the guide guide rail And a reaction force receiving portion that takes a reaction force of the telescopic device in a state of being supported by the guide guide rail.

  In order to achieve the above object, in the construction method of a large section tunnel according to the present invention, a construction method of a large section tunnel using the above-described shield machine moving system, a process of constructing a main tunnel, A step of constructing an underground start base in a ring shape along the outer periphery, a step of providing a guide guide rail extending in the tunnel circumferential direction on the underground start base, and the outer shell shield machine provided with the telescopic device Installing the outer shell shield machine at the predetermined position of the guide guide rail and extending the expansion / contraction device by applying a reaction force to the reaction force receiving portion while changing the expansion / contraction device. The outer shell shield machine is moved in the circumferential direction of the tunnel, the outer shield machine is installed at a predetermined start position, and the outer shield machine is started from the underground start base. Is characterized by comprising the steps of applying a shell tunnel, the.

In the present invention, when the outer shell shield machine is arranged at a predetermined start position of the underground start base provided in the main tunnel, the expansion and contraction device is sequentially repositioned with respect to the guide guide rail, and the reaction force receiving portion is counteracted. It is possible to extend the telescopic device by taking force and guide the outer shield machine to the guide guide rail and move it along the circumferential direction of the tunnel, so that the outer shield machine can be installed at a predetermined start position . Then, the outer shell shield machine is started from the multiple starting positions of the underground starting base to construct a plurality of outer shell tunnels around the main line tunnel, and the inside of the outer shell portion constituted by these outer shell tunnels is excavated. Therefore, it is possible to construct a large-section tunnel having a larger cross section than the main tunnel.
Thus, in the present invention, the outer shell shield machine, which is a heavy object, can be easily moved in the tunnel circumferential direction in an underground space where a large crane called an underground start base cannot be used. Moreover, since the outer shield machine is guided by the guide guide rail, the posture of the moving outer shield machine is stabilized, so that it is possible to reduce time and effort required for positioning work at the starting position.

  Further, in the shield machine moving system according to the present invention, the outer shell shield machine is stored, and a storage frame having a sliding portion that slides along the guide guide rail is provided, and the telescopic device is stored in the storage It is preferable that it is connected to the outer shell shield machine through a frame.

  According to the shield machine moving system of the present invention, the sliding portion of the storage frame storing the outer shell shield machine can be moved by sliding along the guide guide rail. Therefore, since the outer shell shield machine having a cylindrical outer shape is not moved directly along the guide guide rail, the outer shell shield machine can be prevented from rotating around the shield machine axis during the movement.

  Further, in the shield machine moving system according to the present invention, it is preferable that the outer shell shield machine side of the expansion / contraction device has a fixing portion that is detachably fixed to the guide guide rail.

  In this case, when the outer shell shield machine is moving, when the expansion and contraction device is replaced, after the extension device is extended, the fixing portion is fixed to the guide guide rail. Then, the support of the reaction force receiving portion with respect to the guide guide rail is released, the extension device is expanded and contracted to move the position of the reaction force receiving portion, and the reaction force receiving portion is supported on the guide guide rail at the moved position, The removal work can be smoothly performed by releasing the fixing portion from the guide guide rail.

  Moreover, in the construction method of the large-section tunnel according to the present invention, a plurality of the outer shell shield machines may be arranged at predetermined intervals over the entire circumference in the tunnel circumferential direction at the underground starting base.

  In this case, the outer shell shield machine disposed at a predetermined interval in the circumferential direction of the tunnel at the underground start base can be translated and installed. In this case, the outer shield machine can be moved in order from the predetermined location in the underground start base in the order of arrangement in the circumferential direction of the tunnel, and can be installed at the predetermined start position. That is, since a plurality of outer shell shield machines can be simultaneously moved in the underground start base, construction efficiency can be improved and the construction period can be shortened.

  According to the shield machine moving system of the present invention and the method for constructing a large section tunnel, the construction efficiency is improved by moving the outer shield machine to a predetermined start position in the underground start base with a simple structure. The construction period can be shortened.

It is a perspective view which shows the structure of the large cross-section tunnel by embodiment of this invention. It is a figure which shows the outline | summary of the construction method of a large section tunnel, Comprising: It is the side view which fractured | ruptured a part of underground start base. It is a perspective view which shows the construction method of an underground start base, Comprising: It is a figure which shows the state under excavation with an underground start base excavator. It is the partially broken perspective view which shows the structure of a shield machine moving system. It is an AA arrow directional view shown in FIG. 2, Comprising: It is a figure which shows the state which moves a shield machine unit to the predetermined start position of an underground start base. It is an AA arrow line view shown in FIG. 2, Comprising: It is a figure which shows the state which has arrange | positioned the several shield machine unit in the predetermined start position of an underground start base. It is a front view which shows the structure of the movement unit seen from the tunnel axial direction. It is an enlarged view which shows the structure of the expansion-contraction jack and clamp shown in FIG. It is the side view which looked at the movement unit from the tunnel circumferential direction.

  Hereinafter, a shield machine moving system and a method for constructing a large section tunnel according to embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1 to FIG. 3, the shield machine moving system and the large-section tunnel construction method according to the present embodiment, for example, in a large-section road tunnel, excavate the ground by a shield method and use the main tunnel 1. This is applied to the construction for constructing the underground widened portion K in part. Specifically, the main line tunnel 1 is constructed in advance inside the planned excavation position of the underground widened portion K, and a plurality of outer shell tunnels 2 are excavated outside the main line tunnel 1 with a plurality of outer shell shield machines 10. In this construction method, the outer shell portion 20 constructed by these outer shell tunnels 2 and surrounding the main tunnel 1 is constructed, and the underground widening portion K is constructed by excavating the inside of the outer shell portion 20. The main tunnel 1 and the outer shell tunnel 2 are constructed by a well-known shield method. In FIG. 3, the outer shell 2 and the outer shell 20 are omitted.

  Here, the direction of the tunnel axis in the main tunnel 1 is indicated by the symbol X. In the present embodiment, in a plan view of the large-section tunnel viewed from the tunnel axis direction X, a direction orthogonal to the tunnel axis is referred to as a tunnel radial direction, and a direction around the tunnel axis is referred to as a tunnel circumferential direction. In the large section tunnel, the center side in the tunnel radial direction is referred to as the inner peripheral side, and the natural mountain side is referred to as the outer peripheral side.

  The outer shell tunnel 2 is formed from shield start portions 3A (see FIGS. 4 and 5) arranged at a plurality of locations in the tunnel circumferential direction in the underground start base 3 provided at a predetermined position in the tunnel axial direction X of the main tunnel 1. It is started substantially parallel to the main tunnel 1. In addition, according to the size of the outer shell 20 to be constructed, it is gradually dug in the direction away from the main tunnel 1 toward the outside in the radial direction of the tunnel after starting the excavation, and when it reaches a predetermined position. The tunnel may be dug substantially parallel to the main tunnel 1.

The underground start base 3 is provided in a ring shape coaxially with the main tunnel 1 and along the circumferential direction of the tunnel, and along the outer peripheral surface of the main tunnel 1 using an underground start base excavator 30 as shown in FIG. It is constructed by excavating in the circumferential direction and assembling the starting base segment 31. Or you may construct using the support work (steel material, spraying, a lock bolt, etc.) which is not illustrated used with a general tunnel construction method. The distance in the tunnel radial direction of the underground launch base 3 is set to such a size that one outer shell shield machine 10 can start, and a shield machine unit 10A described later can move in the tunnel circumferential direction. Yes.
In addition, when the underground start base 3 is constructed, the ground in the excavation construction range is improved in advance by a freezing method or the like. Moreover, the wall surface of the starting part of the outer shell shield machine 10 is constructed with a material such as carbon fiber-containing concrete that can be cut with a cutting cutter in the same manner as a general shield method.

As shown in FIGS. 4 to 6, the outer shell shield machine 10 is integrally provided with a moving unit 4 for moving along the tunnel circumferential direction in the underground start base 3. The combination of the outer shell shield machine 10 and the moving unit 4 is referred to as a shield machine unit 10A. The shield machine unit 10 </ b> A is guided by a guide guide rail 5 provided along the circumferential direction of the underground start base 3 and is provided so as to be movable in the tunnel circumferential direction, and can be installed at any position of the underground start base 3. It is configured as follows.
Here, the underground start base 3, the moving unit 4, and the guide guide rail 5 correspond to the shield machine moving system of the present invention.

  The guide guide rail 5 includes two inner peripheral guide rails 51 provided along the inner peripheral surface of the underground start base 3 and two outer peripheral guide rails 52 provided along the outer peripheral surface. These guide rails 51 and 52 are made of H-shaped steel, and are arranged so that the flange surface is orthogonal to the tunnel radial direction and along the tunnel peripheral surface.

As shown in FIG. 7, the moving unit 4 accommodates the outer shell shield machine 10 and is moved by being guided and moved by the inner peripheral guide rail 51 and the outer peripheral guide rail 52 (an inner frame member 211 and an outer frame member to be described later). 212), a telescopic jack 42 (stretching device) in which one rod distal end 42a in the telescopic direction is connected to one end in the circumferential direction of the tunnel of the housing frame 41, and a rod base end 42b of the telescopic jack 42. And a clamp 43 (reaction force receiving portion).
As shown in FIG. 8, the shield machine unit 10A takes the reaction force when moving the clamp 43 in the circumferential direction of the tunnel by gripping the clamp 43 by the guide rails 51 and 52, and the connected expansion and contraction jack 42 is used in the circumferential direction of the tunnel. Extrude towards one side.

  The storage frame 41 is in a state of sliding in contact with the inner frame member 411 extending along the inner peripheral guide rail 51 and in the state of sliding along the outer peripheral guide rail 52 as viewed from the tunnel axis direction shown in FIG. An outer frame member 412 that extends, and a vertical frame member 413 that connects ends of the inner frame member 411 and the outer frame member 412 in the circumferential direction of the tunnel, and further, as shown in FIG. A horizontal frame member 414 that connects the inner frame members 411 in the front and the rear in the direction X and the outer frame members 412 is provided.

The storage frame 41 includes a start frame (not shown) of the outer shell shield machine 10. That is, the outer shell shield machine 10 stored in the storage frame 41 is moved along the guide guide rail 5 while being placed on the start frame.
In addition to the start frame, the storage frame 41 includes equipment such as a work stage 46 and subsequent equipment necessary for seed digging, for example, so that the storage frame 41 is moved to a predetermined start position. The excavation preparation work is reduced and the construction period can be shortened.

  The storage frame 41 is provided with a fixing portion (not shown) that is detachably fixed to each of the inner guide rail 51 and the outer guide rail 52. In addition, this fixing | fixed part should just be the outer shell shield machine 10 side of the expansion-contraction jack 42, and is not limited to being provided in the storage frame 41. FIG. For example, the outer shell shield machine 10 may be provided.

  As shown in FIG. 9, the telescopic jack 42 is provided at a position where the telescopic jack 42 is supported via the clamps 43 with respect to the guide rails 51 and 52 of the storage frame 41 in a side view seen from the tunnel circumferential direction. As shown in FIG. 7, the rod base end 42 b of the telescopic jack 42 is fixed to one end of the inner frame member 411 and the outer frame member 412 in the tunnel circumferential direction.

  As shown in FIG. 8, the clamp 43 includes a support portion 44 extending along one direction and a plurality (three in this case) of gripping portions 45 arranged in the longitudinal direction of the support portion 44. The clamp 43 is connected to the rod base end 42 b of the expansion / contraction jack 42 with the longitudinal direction of the support portion 44 facing substantially the same direction as the expansion / contraction axis direction of the expansion / contraction jack 42. The rod tip 42a of the extension jack 42 and the storage frame 41 are connected, and the rod base end 42b of the extension jack 42 and the clamp 43 are connected to each other so as to be rotatable about a horizontal direction orthogonal to the extension / contraction direction.

  The gripping portions 45 are arranged so that each can be gripped by the guide guide rails 5 at the same time. The clamp 43 provided on the inner peripheral guide rail 51 is provided with a grip 45 on the inner peripheral side with respect to the support 44, and the clamp 43 provided on the outer peripheral guide rail 52 is gripped on the outer peripheral with respect to the support 44. A portion 45 is provided.

  In the shield machine unit 10A configured as described above, the outer shell shield machine 10 is guided by sequentially changing the gripping position of the clamp 43 with respect to the guide guide rail 5 in accordance with the stroke caused by the extension (extension) of the telescopic jack 42. It is moved along the guide rail 5 in the tunnel circumferential direction.

Next, the construction method of the large-section tunnel using the shield machine moving system described above will be described based on the drawings.
As shown in FIGS. 3 and 5, in the present embodiment, the underground start base 3 is constructed at a predetermined position before the planned construction position of the underground widened portion K of the existing main line tunnel 1, and the underground A plurality of outer shell shield machines 10 are started from the departure base 3 and a plurality of outer tunnels 2 are constructed outside the main tunnel 1.

  When the underground start base 3 was constructed, as shown in FIG. 3, the underground start base excavator 30 made of a seal excavator having a rectangular cross section was dug down and set to a size capable of starting. The underground start base excavator starter 32 is constructed. In this underground start base excavator starter 32, an underground start base excavator 30 is arranged so that one side in the circumferential direction of the tunnel is a face, and the underground start base excavator 30 extends along the outer periphery of the main tunnel 1. As shown in FIG. 1, a ring-shaped underground start base 3 as shown in FIG. 1 is constructed around the main tunnel 1 by installing the start base segment 31. And as shown in FIG. 4, the inner periphery guide rail 51 and the outer periphery guide rail 52 are installed in the underground start base 3 along the tunnel circumferential direction.

  Next, as shown in FIG. 5, in the underground starting base excavator starting unit 32, the outer shell shield machine 10 including the moving unit 4 is installed on the guide guide rails 51 and 52. That is, as shown in FIG. 7, in the outer shell shield machine 10 stored in the storage frame 41 together with the starting frame, the extension jack 42 and the clamp 43 are provided at predetermined positions of the storage frame 41. Then, the guide guide rail 5 is held by the holding portion 45 of the clamp 43. At this time, the inner frame member 411 and the outer frame member 412 of the storage frame 41 are provided in sliding contact with the guide guide rail 5.

Then, as shown in FIGS. 5 and 7, the shield jack unit 10 </ b> A is sequentially tunneled along the guide guide rail 5 by extending and retracting the extension jack 42 and repeatedly attaching and detaching the clamp 43 to and from the guide guide rail 5. Move in the circumferential direction. At this time, since the rods are extended by synchronizing the four telescopic jacks 42, the storage frame 41 is moved in a state where the balance in the direction in which the central axis of the outer shell shield machine 10 faces the guide guide rail 5 is maintained. be able to. That is, it is possible to prevent the axis of the storage frame 41 from deviating from the direction along the tunnel axis, so that the positioning work performed after moving to a predetermined position in the tunnel circumferential direction is simplified.
Here, the moving direction of the shield machine unit 10A in the underground starting base 3 may be either the forward or reverse direction in the tunnel circumferential direction. That is, by moving the shield machine unit 10A from the underground start base excavator starter 32 toward both sides of the tunnel circumferential direction, the longest movement distance becomes a range of 180 degrees, and the movement distance of one shield machine unit 10A Can be suppressed and work efficiency can be improved.

  In this embodiment, when the outer shell shield machine 10 is moving, when the telescopic jack 42 is replaced, the telescopic jack 42 is stretched, and then a fixed portion (not shown) provided in the storage frame 41 is guided to the guide guide rail. Fix to 5. Then, the support of the clamp 43 with respect to the guide guide rail 5 is released, the telescopic jack 42 is expanded and contracted to move the position of the clamp 43, and the clamp 43 is supported by gripping the guide guide rail 5 at the moved position. By removing the fixed portion from the guide guide rail 5, the refilling operation can be performed smoothly.

As shown in FIG. 6, a plurality of shield machine units 10 </ b> A are arranged at predetermined start positions at predetermined intervals over the entire circumference in the tunnel circumferential direction at the underground start base 3. FIG. 5 is a view in which the last one of the outer shell shield machine 10 is carried in, and since there is no movement in the circumferential direction, the storage frame 41 is not necessary, and the outside installed in the underground start base 3 The outer shell shield machine 10 may be installed directly on the shell shield machine start frame.
Next, each outer shell shield machine 10 is started at the same time or individually, and the outer shell tunnel 2 is constructed by performing backfill injection and assembling segments along with the excavation. The excavated earth and sand at this time are carried outside through the underground start base 3 through the main tunnel 1 and materials such as segments necessary for excavation are transferred from the main tunnel 1 through the underground start base 3 into the outer shell tunnel 2. It is carried in.
In this way, a plurality of outer shell tunnels 2 are constructed substantially along the tunnel axial direction X, and an outer shell portion 20 including a plurality of outer shell tunnels 2 is constructed around the main tunnel 1.

  Here, the outer shell tunnel 2 to be constructed is dug almost parallel to the tunnel axis direction X immediately after the outer shell shield machine 10 is started. For example, the entire body of the outer shell shield machine 10 or the entire subsequent equipment is underground. When advancing into the ground from the departure base 3, the tunnel is excavated to a predetermined position while being bent away from the main tunnel 1 to the outside in the tunnel radial direction, and further in the predetermined tunnel radial direction with respect to the main tunnel 1 at the predetermined position. The outer shell tunnel 2 may be constructed by digging substantially parallel to the main tunnel 1 at the position. Thereby, the cross section of the outer shell portion 20 formed by the plurality of outer shell tunnels 2, 2,... Can be enlarged.

Next, after the ground improvement is performed between the outer shell tunnels 2 and 2 adjacent to each other in the circumferential direction of the tunnels among the plurality of outer shell tunnels 2 constructed by a freezing method, a chemical solution injection method, etc. Integration is achieved by connecting as a body, thereby forming the outer shell 20 having a support function and a water stop function.
In addition, after constructing the outer shell tunnel 2 by excavation, the outer shell shield machine 10 is disassembled by reaching a planned wall wall point of the underground widened portion K.

  Then, while excavating the inside of the outer shell portion 20 constituted by the plurality of outer shell tunnels 2 while disassembling and removing the segment near the anchor wall in the main tunnel 1 of the anchor wall planned site and constructing the anchor wall, The remaining segments in the shield roof of the main tunnel 1 are dismantled and removed, and a large-section tunnel (underground widened portion K) is constructed.

Next, the operation of the shield machine moving system and the method for constructing the large section tunnel described above will be described in detail based on the drawings.
As shown in FIG. 4, in the present embodiment, the outer shell shield machine 10 that is a heavy object is easily moved in the tunnel circumferential direction in an underground space where a large crane called the underground start base 3 cannot be used. Can do. Moreover, since the outer shield machine 10 is guided by the guide guide rail 5, the posture of the outer shield machine 10 during movement is stabilized, so that it is possible to reduce the time and effort required for positioning work at the starting position. .

  In the present embodiment, the sliding portions (the inner frame material 411 and the outer frame material 412) of the storage frame 41 storing the outer shell shield machine 10 are slid along the guide guide rail 5 and moved. it can. Therefore, since the outer shell shield machine 10 having a cylindrical outer shape is not moved directly along the guide guide rail 5, the outer shell shield machine 10 can be prevented from rotating around the shield machine axis during the movement. .

  Moreover, in the construction method of the large-section tunnel according to the present embodiment, since the plurality of outer shell shield machines 10 are arranged at predetermined intervals over the entire circumference in the tunnel circumferential direction at the underground start base 3, The outer shell shield machine 10 can be translated and installed. In this case, the outer shield machine 10 can be moved in order from the predetermined location in the underground start base 3 in the order of arrangement in the circumferential direction of the tunnel, and can be installed at the predetermined start position. That is, since a plurality of outer shell shield machines 10 can be simultaneously moved in the underground start base 3, the construction efficiency can be improved and the construction period can be shortened.

  As described above, in the shield machine moving system and the large-section tunnel construction method according to the present embodiment, by moving the outer shield machine 10 to a predetermined start position in the underground start base 3 with a simple structure, Construction efficiency can be improved and the construction period can be shortened.

As mentioned above, although embodiment of the construction method of the shield machine movement system by this invention and the large section tunnel was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it is appropriate. It can be changed.
For example, although the storage frame 41 is provided as the moving unit 4 in the present embodiment, the storage frame 41 is not limited to the configuration in which the storage frame 41 is provided, and the storage frame 41 may be omitted. It is. In this case, the expansion jack 42 may be attached directly to the outer shell shield machine 10.

  In the present embodiment, a plurality of outer shell shield machines 10 are arranged at predetermined start positions at predetermined intervals over the entire circumference in the tunnel circumferential direction in the underground start base 3. There is no limit to the method. A method may be used in which the outer shell shield machine 10 is moved to a predetermined start position one by one to dig.

  Further, in the present embodiment, the underground start base 3 is constructed by excavating the underground start base excavator 30 from the underground start base excavator starting portion 32 along the outer periphery of the main tunnel 1 in a ring shape. However, it is not limited to such a construction method, and the underground start base 3 may be constructed by a method of expanding by the NATM method or a conventional mountain tunnel method. The underground start base 3 is not necessarily limited to the ring shape, and may be a rectangular cross section, an arch shape, or the like. The point is that the ring-shaped guide guide rail along the circumferential direction of the tunnel may be provided in the underground starting base.

Furthermore, the position, size, etc. of the underground start base 3 can be appropriately set according to conditions such as the outer diameter of the main tunnel 1, the outer diameter of the outer shell shield machine 10, and the ground. Further, the configuration of the outer shell shield machine 10 and the configuration such as the outer diameter are not limited to the present embodiment, and can be determined as appropriate.
Further, regarding the guide guide rail 5, in the present embodiment, two inner guide rails 51 and two outer guide rails 52 are arranged, but the number and position of the guide guide rails 5 are also particularly limited. It is not something.

  Also, in this embodiment, it is an application example when constructing a road tunnel with a large cross section, but it can be widely applied in general when constructing tunnels of various scales, uses, and forms having the above-mentioned underground widened portion. In addition, various design changes can be made in accordance with the scale and form of the underground widened portion in the tunnel to be constructed and in consideration of various conditions such as the surrounding environment.

  In addition, the range of the ground improvement part by the freezing method that is integrally formed between adjacent outer shell tunnels, the form and its construction method, and other details of each process are also optimal within the scope of the present invention. It is sufficient to design, and of course, an appropriate auxiliary method may be adopted as necessary.

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

DESCRIPTION OF SYMBOLS 1 Main line tunnel 2 Outer shell tunnel 3 Underground start base 3A Shield start part 4 Movement unit 5 Guide guide rail 10 Outer shell shield machine 10A Shield machine unit 20 Outer shell part 41 Storage frame 42 Telescopic jack (extensible device)
43 Clamp 44 Supporting part 45 Holding part 51 Inner peripheral guide rail X Tunnel axial direction K Underground widening part

Claims (5)

An underground launch base that is used to construct an outer shell by excavating the ground and launching an outer shell shield machine from a part of the main tunnel, and constructed in a ring shape along the outer periphery of the main tunnel A shield machine moving system provided in
A guide guide rail that extends in the tunnel circumferential direction to the underground launch base and guides the outer shell shield machine in the tunnel circumferential direction;
A telescopic device connected to one end of the outer shell shield machine in the tunnel circumferential direction and stretchable along the tunnel circumferential direction;
A reaction force receiving portion that is detachably supported with respect to the guide guide rail, and that takes a reaction force of the telescopic device in a state of being supported by the guide guide rail;
A shield machine moving system characterized by comprising: While storing the outer shell shield machine, a storage frame having a sliding portion that slides along the guide guide rail is provided,
2. The shield machine moving system according to claim 1, wherein the expansion and contraction device is connected to the outer shell shield machine via the storage frame.   3. The shield machine moving system according to claim 1, further comprising a fixing portion that is detachably fixed to the guide guide rail on the outer shell shield machine side of the telescopic device. . A construction method of a large-section tunnel using the shield machine moving system according to any one of claims 1 to 3,
The process of constructing the main tunnel,
Constructing an underground start base in a ring shape along the outer periphery of the main tunnel,
Providing a guide guide rail extending in the tunnel circumferential direction at the underground starting base;
Installing the outer shield machine provided with the telescopic device at a predetermined position of the guide guide rail;
While changing the expansion and contraction device, the reaction force receiving portion takes a reaction force to extend the expansion and contraction device and guide the outer shell shield machine to the guide guide rail and move it along the circumferential direction of the tunnel. Installing the outer shell shield machine at a predetermined start position;
Starting the outer shell shield machine from the underground launch base and constructing an outer shell tunnel;
A construction method of a large-section tunnel characterized by comprising:   5. The construction method for a large-section tunnel according to claim 4, wherein a plurality of outer shell shield machines are arranged at predetermined intervals over the entire circumference in the tunnel circumferential direction at the underground starting base.

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