JP5479989B2 - Tunnel construction method and shield machine - Google Patents

Description

  The present invention relates to a tunnel construction method in which a construction method can be changed during construction of a tunnel having a large cross section, and a shield machine used therefor.

  Conventionally, when constructing a tunnel, for example, a shield machine of a SENS (Shield machine expanded NATM System) method of excavating while casting cast concrete behind a shield machine may be used. By using a shield machine for cast-in-place concrete (ECL (Extracted Concrete Lining), it is possible to dig up and cast a tunnel while placing concrete using the inner formwork and the end formwork behind the shield machine ( Hereinafter, it will be referred to as a tunnel construction method using the cast-in-place concrete method).

  On the other hand, there is a method of digging while constructing a segment behind the shield machine and constructing a tunnel (hereinafter referred to as a segment construction method). In order to construct a tunnel by the segment method, it is necessary to use a shield machine for the segment method. The cast-in-place concrete method and the segment method are normally used in consideration of the location and mode of the tunnel to be constructed, cost, construction period, and the like. Therefore, when constructing a tunnel, it is necessary to determine in advance what construction method should be adopted and to select a shield machine to be used.

  However, depending on the tunnel, you may want to use these methods depending on the strength of the ground and the construction site. Therefore, the construction method which can respond to both types is desired.

  As such a method, for example, when constructing a tunnel or the like, there is a method of lining with cast-in-place concrete and a segment using one shield machine (Patent Document 1, Patent Document 2).

7-86317 JP2004-52467

  However, neither method of Patent Document 1 nor Patent Document 2 describes a specific method for installing members, water stopping, or the like in switching between the segment method and the cast-in-place concrete method. For this reason, there is a problem of water leakage from the rear of the shield machine at the time of switching work in the switching part of the system, and a problem that it is difficult to assemble and install segments and inner molds in a narrow position. Moreover, if the strength of the reaction force transmission portion of the shield machine in the method switching portion is not sufficient, the constructed concrete portion or segment portion may be damaged.

  The present invention has been made in view of such problems, and can be switched between a cast-in-place concrete method and a segment method with a single shield machine at the time of tunnel construction, there is no problem of water leakage that can be placed at the time of switching, and switching work An object of the present invention is to provide a tunnel construction method and a shield machine used therefor.

  In order to achieve the above-described object, the first invention is a tunnel construction method for switching from a cast-in-place concrete method to a segment method in the middle of excavation, and a propulsion jack provided in a skin plate and a shield machine behind Wife formwork used as a formwork of cast-in-place concrete, wife formwork jack capable of moving forward and backward with the wife formwork, a first seal part detachable with respect to the inner surface of the wife formwork, A method using cast-in-place concrete with the inner mold frame and the wife mold frame as a mold frame while using the shield machine having a second seal part detachable with respect to the inner surface of the skin plate. The step (a) of constructing a tunnel in step (b) and water stopping near the rear end of the skin plate are performed, and the wife formwork is pulled forward of the shield machine by the wife formwork jack. And (b) removing the first seal portion and moving the second seal portion rearward of the skin plate and joining the skin plate in the vicinity of the rear end thereof by the jack frame jack. (C) and a step (d) of moving the first segment to the rear of the skin plate and joining the first segment to the outer periphery of the inner mold frame by the wife mold jack, A step (e) of installing a second segment in front of one segment and moving the shield machine forward to construct a tunnel by a segment method.

  The step (c) is a step of moving the wife mold frame and the second seal part rearward by the wife mold jack after installing the second seal part behind the wife mold frame. Yes, the step (d) includes pulling back the wife formwork to the front of the shield machine by the wife formwork jack, and installing the first segment behind the wife formwork jack; A step of moving the wife formwork and the first segment to the rear of the skin plate by a jack for the use, wherein the step (e) is a step of moving the wife formwork to the front of the shield machine by the jack for the formwork frame. The propulsion jack is pushed against the first segment to advance the shield machine, and the first filler is filled outside the first segment, and the propulsion jack is moved to the second segment. No While against the instrument to advance the shield machine may be a step of filling the second sealing member outwardly of the second segment.

  The shield machine further includes a ring member that can be attached to and detached from the inner surface of the skin plate and that can slide along the skin plate, and in the step (c), the ring member is installed behind the end formwork. The second seal portion is installed behind the ring member, and the ring member and the second seal portion are moved rearward of the skin plate by the wife formwork jack. (D) pulls back the wife formwork and the ring member to the front of the shield machine by the wife formwork jack, installs a first segment behind the ring member, and uses the wife formwork jack, It may be a step of moving the ring member and the first segment to the rear of the skin plate.

  The shield machine includes an embedded freezing pipe provided in the vicinity of the rear end of the skin plate, and the step (b) includes a step of freezing and water-stopping a ground near the rear end of the skin plate by the embedded freezing pipe. It is desirable that

  A spreader is attached to the tip of the propulsion jack, and in step (e), the shaft core of the spreader provided at the tip of the propulsion jack is eccentric in the outer peripheral direction, and the propulsion jack is moved to the first end. It is desirable that the shield machine is advanced by pressing against one segment. In this case, the center of the spreader shaft is offset outwardly from the inner mold spreader. The spreader may be replaced with a segment spreader, and the shaft center of the spreader may be decentered by sliding the propulsion jack in the outer peripheral direction of the shield machine. Moreover, you may combine these.

  The first filler is preferably mortar, and the second filler is preferably a backfill material having a lower strength than the first filler.

  The first segment is a segment having a tapered shape, and the step (d) is a step in which a temporary segment is provided in front of the first segment, and the step (e) is performed together with the temporary segment. The first segment may be moved rearward, the temporary segment and the first segment may be separated, and the temporary segment may be pulled back to the front of the shield machine.

  According to the present invention, water is stopped near the rear end of the skin plate at the time of system switching, so there is no risk of water leakage from the natural ground. In particular, by using an embedded freezing tube embedded in the vicinity of the rear end of the skin plate, water can be stopped easily and reliably without interfering with other members.

  In addition, the first segment is provided on the outer periphery of the inner mold frame at the boundary between the inner mold frame and the segment, and the second segment is provided in front of the first segment. The pressing force is transmitted reliably and there is no risk of damage to the inner mold.

  Also, by using a wife form jack for moving the second seal part and the first segment to the rear of the skin plate, it is possible to assemble in a wide working space and easily move to the installation position. Therefore, workability is excellent.

  In particular, when moving the second seal part and the first segment to the rear of the skin plate, by providing a ring member behind the wife formwork, these members are moved rearward beyond the stroke of the wife formwork jack. It is not necessary to enlarge the wife form jack more than necessary.

  Also, the first segment is filled with the first filler, and the second segment is filled with the second filler, thereby reliably preventing water leakage from the ground. be able to. At this time, the first filler is, for example, a mortar having substantially the same strength as the concrete used in cast-in-place concrete (such as cast-in concrete removed), and the second filler is For example, by using a lower-strength filler than the first filler, such as mortar containing bentonite that has been used in the past, a higher-strength filler is filled near the boundary of the system change. Thus, it is possible to reliably crack and stop the water, and it is not necessary to use a filler having excessive strength in other portions.

  In addition, along with the change in construction method, when the shaft core (the center of the pressing surface) of the spreader used for the part where stress is transmitted backward by the propulsion jack is changed from the inner mold frame pressing to the segment pressing, the outer circumferential direction Therefore, the pressing force can be reliably transmitted to the inner mold frame and the segment as well. In this case, if the spreader for the inner mold is changed to the spreader for the segment that is eccentric outward than the spreader for the inner mold, the position of the spreader can be eccentric to the outer periphery without having a special mechanism. Further, instead of this, or in combination with this, the same effect can be obtained by moving the propulsion jack itself in the outer peripheral direction of the shield machine.

  A second invention is a tunnel construction method for switching from a segment method to a cast-in-place concrete method during excavation, and a propulsion jack provided in a skin plate and a cast-in-place concrete formwork behind a shield machine Wife mold frame used as a wife, a wife mold jack capable of moving the wife mold frame back and forth, a first seal portion detachable from the inner surface of the wife mold frame, and a detachable attachment to the inner surface of the skin plate A second shield can be used, and a second segment can be installed and a second filler can be filled outside the second segment to construct a tunnel in a segmented manner. A step (p) of performing a step (q) of stopping water in the vicinity of the rear end of the skin plate, and joining an inner form reaction force ring to the inner periphery of the second segment, Water stop in the vicinity of the rear end, removing the second seal part from the skin plate (r), installing an inner mold in front of the inner mold reaction force ring, A first seal portion is installed on the inner surface of the frame, the wife frame is moved to the vicinity of the rear end of the skin plate, and the first segment is formed outside the second segment in the vicinity of the rear end of the skin plate. A tunnel construction comprising: a step (s) of filling a filler; and a step (t) of constructing a tunnel by a cast-in-place concrete method using the inner mold frame and the end mold frame as a mold frame. Is the method.

  According to the second invention, it is possible to change from the segment method to the cast-in-place concrete method by performing the reverse process of the first invention. In this case, by providing the inner form reaction force ring on the inner periphery of the segment at the system change boundary part, the pressing force from the propulsion jack can be reliably transmitted at the boundary part.

  A third invention is a shield machine capable of arbitrarily changing a segment system and a cast-in-place concrete system during excavation, and a propulsion jack provided in a skin plate, and a cast-in-place concrete behind the shield machine A wife formwork used as a formwork, a wife mold jack capable of moving the wife form back and forth, an embedded freezing tube provided near the rear end of the skin plate, and an inner surface of the wife formwork A first seal portion provided detachably, a second seal portion provided detachably on the inner surface of the skin plate, and a ring detachable with respect to the inner surface of the skin plate and slidable along the skin plate And a member.

  According to the third invention, the segment method and the cast-in-place concrete method can be switched at an arbitrary place during excavation and at an arbitrary number of times.

  According to the present invention, at the time of tunnel construction, it is possible to switch between the cast-in-place concrete method and the segment method with a single shield machine, there is no problem of water leakage that can be placed at the time of switching, and a tunnel construction method that can be easily switched and used for this Can be provided.

It is a figure which shows the shield machine 1, (a) is a schematic sectional side view, (b) is the A section enlarged view of (a). The figure which shows the process of switching from a cast-in-place concrete system to a segment system, and is a figure which shows the installation process of the tail seal 27. The figure which shows the process of switching from a cast-in-place concrete system to a segment system, and is a figure which shows the installation process of the taper segment 29. FIG. The figure which shows the process of switching from a cast-in-place concrete system to a segment system, and is a figure which shows the assembly process of the segment 35. FIG. The figure which shows the process of switching to a cast-in-place concrete system from a segment system, and is a figure which shows the installation process of the inner-frame form reaction force ring 41. FIG. The figure which shows the process of switching to a cast-in-place concrete system from a segment system, and is a figure which shows the installation process of the end-frame inner periphery seal | sticker 18. FIG. The figure which shows the process switched from a segment system to a cast-in-place concrete system, and is a figure which shows the filling process of the mortar 37. FIG. The figure which shows the process of switching from a segment system to a cast-in-place concrete system, and is a figure which shows the assembly process of the inner formwork 15. It is a figure which shows the sliding state of the jack for propulsion 7, (a) is a figure which shows the state located in the inner peripheral direction, (b) is a figure which shows the state moved to the outer peripheral direction.

  Hereinafter, a tunnel construction method according to an embodiment of the present invention will be described. FIG. 1 is a view showing a shield machine 1 used in the present invention, FIG. 1 (a) is a schematic side sectional view of the shield machine 1, and FIG. 1 (b) is an enlarged view of a portion A in FIG. 1 (a). It is. In FIG. 1B (and subsequent drawings), for the sake of simplicity, the propulsion jack 7 is shown together with the wife formwork jack 11 on the same drawing. FIG. 1 is a diagram showing a state in which the shield machine 1 constructs a tunnel by a cast-in-place concrete method. The shield machine 1 is mainly composed of a skin plate 3, a cutter head 5, a propulsion jack 7, a wife mold 9, a wife mold jack 11, a screw conveyor 13, and the like.

  The skin plate 3 is a cylindrical member, and a cutter head 5 is provided in front. The cutter head 5 excavates a natural ground in front of the shield machine 1 and can be rotated by a motor or the like (not shown). A plurality of jacks for propulsion 7 are provided on the inner surface of the skin plate 3 at predetermined intervals in the circumferential direction of the skin plate 3. The propulsion jack 7 presses the rear segment, the inner mold, and the like, and propels the shield machine 1 with the reaction force.

  On the inner periphery of the skin plate 3, a plurality of wife form frame jacks 11 are provided in the circumferential direction in the same manner as the propulsion jack 7. A ring-shaped wife mold 9 is provided at the tip of the wife mold jack 11. That is, the wife mold 9 can be moved in the front-rear direction of the shield machine 1 by the wife mold jack 11. Note that the wife form jack 11 and the propulsion jack 7 are arranged with their circumferential positions shifted so as not to interfere with each other, and are located between the propulsion jacks 7 and slightly outward from the propulsion jack 7. A frame jack 7 is arranged.

  As shown in FIG. 1B, an inner mold spreader 19 is provided at the tip of the propulsion jack 7. The inner mold spreader 19 is a portion that is pressed against the inner mold 15 by the propulsion jack 7 and applies a pressing force to the inner mold 15. That is, the center position of the pressing surface of the inner mold spreader 19 (the radial position of the shield machine 1) is arranged so as to coincide with the radial position of the inner mold frame 15 in the shield machine 1. In the following description, the center of the pressing surface of the ring-shaped spreader (the radial position of the shield machine 1) is called the spreader axis.

  On the inner peripheral surface of the wife mold 9, a wife mold inner peripheral seal 18 is provided. The first frame inner peripheral seal 18 is a brush-like member that functions as a seal member when placing concrete, and can be attached to and removed from the inner peripheral surface of the wife mold 9 with bolts or the like. Installed.

  A freezing tube 21 is embedded in the vicinity of the rear end portion of the skin plate 3 over the entire circumference. A refrigerant is flowed through the freezing tube 21 to cool surrounding natural ground. That is, it is possible to freeze and stop the ground and concrete near the rear end of the skin plate 3. The skin plate 3 has such a thickness that the freezing tube 21 can be embedded.

  The shield machine 1 excavates a natural ground in front of the shield machine 1 with a cutter head 5 and conveys excavated earth and sand to the rear of the shield machine 1 with a screw conveyor 13 while propelling jack 7 (inner formwork spreader 19). Is pressed against the inner mold 15 and is propelled forward by a repulsive force. At this time, the end form 9 is disposed in the vicinity of the rear end of the skin plate 3, and concrete 17 is placed in a space surrounded by the inner form 15, the end form 9, and the surrounding ground. The concrete 17 is placed behind the end form 9 by a mixer and a pump (not shown). In addition, installation and removal of the inner mold 15 are performed using an inner mold assembling apparatus and an inner mold removing apparatus that are not shown.

  The wife formwork jack 11 moves the wife formwork 9 in the front-rear direction of the shield machine 1 in accordance with the placement amount, pressure, and the like of the concrete 17. When a predetermined amount of concrete 17 is placed, the propulsion jack 7 is shrunk, and the inner mold 15 is further assembled and propelled in front of the existing inner mold 15 by an inner mold assembling apparatus (not shown). Push the jack 11 and move forward. While repeating the above, a tunnel can be constructed by the cast-in-place concrete method.

  Next, a method for switching from the cast-in-place concrete method to the segment method during tunnel construction will be described. 2-4 is a figure which shows the process of a system switching.

  First, as described above, a tunnel is constructed by a cast-in-place concrete method. After the cast concrete 17 is solidified, as shown in FIG. 2A, the freezing pipe 21 freezes and stops the ground in the vicinity of the rear end portion of the skin plate 3 to form a water stop portion 23. . Next, the wife mold jack 11 is driven, and the wife mold 9 is pulled back to the front of the shield machine 1 (in the direction of arrow B in the figure). At this time, since the vicinity of the back of the skin plate 3 is frozen and stopped, there is no fear of water leakage from here. In addition, even in a very narrow part, if it is the embedded freezing tube 21, water leakage can be reliably stopped at a leaking dangerous part.

  Next, as shown in FIG. 2 (b), the end form inner peripheral seal 18 is removed from the end form 9. In addition, a ring member 25 is installed behind the end form 9 and joined to the end form 9. The ring member 25 is a ring-shaped member that is slidable in the axial direction along the inner periphery of the skin plate 3. The ring member 25 is installed in accordance with the stroke of the end form jack 11 and the amount of movement of a tail seal 27 and the like which will be described later. A tail seal 27 is installed behind the ring member 25. The tail seal 27 that is the second seal portion is a member in which a brush-like member is provided on the inner periphery of the ring-shaped member, and is slidable in the axial direction along the inner periphery of the skin plate 3. If necessary, the ring-shaped member of the tail seal 27 is provided with a flange portion for joining to the ring member 25 and joined to the flange portion of the ring member 25.

  Next, as shown in FIG. 2C, the wife formwork jack 11 is driven to move the wife formwork 9 backward (in the direction of arrow C in the figure). That is, the ring member 25 and the tail seal 27 are slid rearward by the wife mold 9.

  Next, as shown in FIG. 2D, the tail seal 27 is disposed in the vicinity of the rear end portion of the skin plate 3, and the tail seal 27 is joined to the inner surface of the skin plate 3. In this state, the flange portion of the tail seal 27 is removed. Furthermore, the wife mold jack 11 is driven to pull the wife mold 9 and the ring member 25 joined to the wife mold 9 back to the front of the shield machine 1 (in the direction of arrow D in the figure).

  Next, as shown in FIG. 3A, the temporary segment 31 and the taper segment 29 are joined to the rear of the ring member 25. The taper segment 29, which is the first segment, is a part that receives a pressing force from the propulsion jack at the switching boundary to the segment system. The temporary segment 31 is a member for installing the taper segment 29 at a predetermined position of the inner mold 15, and is a segment that is substantially the same size as the front surface (pressing surface) of the taper segment 29.

  As shown in FIG. 3B, the wife formwork jack 11 is driven to move the wife formwork 9 to the rear of the shield machine 1 (in the direction of arrow E in the figure). That is, the end form 9 and the temporary segment 31 and the taper segment 29 joined thereto are moved backward. The taper segment 29 is joined to the outer surface of the inner mold frame 15 at a position where the end surface of the inner mold frame 15 and the end surface of the taper segment 29 (joint surface with the temporary segment 31) substantially coincide with each other. Since the taper segment 29 has a tapered shape with a thick front portion, it can reliably receive a pressing force from the front.

  Next, as shown in FIG.3 (c), the temporary fix | stop of the temporary segment 31 and the taper segment 29 is removed. Further, the wife formwork jack 11 is driven, and the wife formwork 9 and the temporary segment 31 joined to the wife formwork 9 are pulled back to the front of the shield machine 1 (in the direction of arrow F in the figure).

  Next, as shown in FIG. 4A, the ring member 25 and the temporary segment 31 are separated and removed. Further, the inner mold spreader 19 is replaced with the segment spreader 33. The segment spreader 33 is a member whose axis is located on the outer peripheral side of the inner formwork spreader 19. The segment spreader 33 is arranged so that the axial center of the segment spreader 33 coincides with the radial position of the segment 35 installed in the shield machine 1.

  In this state, a segment 35 as a second segment is installed in front of the inner mold 15 and the taper segment 29. The segment 35 is a steel segment, for example.

  Further, as shown in FIG. 4B, the segment 35 is pressed by the propulsion jack 7 (segment spreader 33) and propelled while repeating the installation of the segment 35. At this time, the outer side of the taper segment 29 (and the outer side of the segment 35 in contact with the taper segment 29) is filled with mortar 37 from the rear side of the skin plate 3. It is desirable that the mortar 37 as the first filler has substantially the same strength as the concrete 17. For example, it is a material in which only the aggregate is omitted from the concrete 17. In addition, after filling with the mortar 37, you may stop the water stop by the freezing tube 21. FIG.

  As shown in FIG. 4C, the vicinity of the boundary between the inner mold 15 and the segment 35 is filled with mortar 37, but after that (front side), the outside of the segment 35 is backed. It digs while filling the material 39. The backfill material 39 is a mixture of bentonite or the like with mortar, and does not require any particular strength. That is, the backing material 39 has a lower strength than the mortar 37. As described above, the installation of the segment 35 and the like can be repeated to construct the tunnel by the segment method. That is, it is possible to switch from the cast-in-place concrete method to the segment method.

  Next, a method for switching from the segment method to the cast-in-place concrete method during tunnel construction will be described. FIG. 5 to FIG. 8 are diagrams showing the method switching process. In the following description, the same description as that shown in FIGS. 2 to 4 is omitted.

  First, as shown in FIG. 5B, the vicinity of the rear end portion of the skin plate 3 is frozen and stopped by the freezing pipe 21 with respect to the construction state of the tunnel by the segment method as shown in FIG. Thereby, the water leakage from the backfill material 39 and the natural ground side can be prevented.

  Further, the inner form reaction force ring 41 is joined to the inner peripheral surface of the segment 35 (the segment 35 located on the foremost side) installed last before switching. The inner form reaction force ring 41 is a member having a tapered cross-sectional shape with a thick front side. The inner mold reaction force ring 41 is a ring-shaped member, and the outer peripheral surface is joined to the inner peripheral surface of the segment 35. At this time, the end surface of the inner mold reaction force ring 41 and the end surface of the segment 35 are installed so as to substantially coincide with each other. The inner form reaction force ring 41 may be joined so as to straddle the plurality of segments 35.

  Next, as shown in FIG. 5C, the segment spreader 33 is replaced with the inner formwork spreader 19. The inner formwork spreader 19 can press the inner formwork reaction force ring 41 and the segment 35. Furthermore, the ring member 25 is installed and joined to the rear side of the wife formwork 9.

  Next, as shown in FIG. 6A, the wife formwork jack 11 is driven to move the wife formwork 9 and the ring member 25 backward (in the direction of arrow G in the figure). When the ring member 25 moves to the position of the tail seal 27, the flange or the like is joined and the ring member 25 and the tail seal 27 are joined. Further, the joint between the tail seal 27 and the skin plate 3 is removed.

  Next, as shown in FIG. 6B, the wife formwork jack 11 is driven, and the wife formwork 9, the ring member 25 and the tail seal 27 joined thereto are pulled back to the front of the shield machine 1 (see FIG. 6B). Middle arrow H direction).

  Next, as shown in FIG. 6C, the ring member 25 and the tail seal 27 are removed. Further, a wife mold inner peripheral seal 18 is attached to the inner peripheral surface of the wife mold 9.

  Next, as shown in FIG. 7A, the inner mold 15 is joined to the front of the inner mold reaction force ring 41 and pressed by the propulsion jack 7 (inner mold spreader 19). Before and after this, the wife mold jack 7 is driven to move the wife mold 9 backward (in the direction of arrow I in the figure).

  Further, as shown in FIG. 7B, the outer periphery of the segment 35 to which the inner form reaction force ring 41 is attached is filled with a mortar 37. In addition, when filling with the mortar 37, you may stop the water stop by the freezing pipe 21. FIG.

  From the above state, as shown in FIG. 8A, concrete 17 is placed outside the inner mold 15 with the end mold 9 and the inner mold 15 as molds. While placing the concrete 17, the inner mold 15 is pressed to propel the shield machine. As shown in FIG. 8 (b), the tunnel is constructed by a cast-in-place concrete method while assembling the inner mold 15 sequentially (in the direction of arrow J in the figure).

  According to the tunnel construction method according to the present embodiment, the segment method and the cast-in-place concrete method can be easily switched any number of times during the tunnel construction.

  Further, when installing or removing the tail seal 27, the taper segment 29 used at the time of system switching, the reaction force ring 41 for the inner mold, or the like behind the shield machine 1 as necessary, A ring member 25 is used. For this reason, the assembly and installation work is performed in a relatively wide region, and the member can be easily moved backward, so that the workability is excellent.

  In addition, since the freezing pipe 21 is embedded in the rear end portion of the skin plate 3, it is possible to reliably prevent water leakage from a natural ground or the like in the vicinity of the method change boundary during the operation at the time of method switching. At the same time, since the freezing tube 21 is not exposed from the skin plate 3, it does not hinder the work or interfere with other members at the time of tunnel construction or the like.

  The tapered segment 29 used when switching to the segment system and joined to the inner mold 15 has a thick tapered cross section at the front, so that it can reliably receive a pressing force from the front and move to the inner mold 15 and the like. A pressing force can be transmitted. Further, since the temporary segment 31 is used, it is easy to match the fixing position of the taper segment 29 with the end surface of the inner mold 15.

  Further, since the mortar 37 having high strength is filled outside the system switching boundary, it is possible to prevent the boundary from cracking, leaking water, etc., and to the outside of the normal segment, the minimum required Since the limited backfill material 39 is filled, there is no excessive strength.

  Further, since the taper segment 29 and the reaction force ring 41 for the inner mold frame are used in the vicinity of the system switching boundary portion, the strength is higher than the case of only the inner mold frame 15 and only the segment 35, and the propulsion jack 7 There is no fear of breakage against the pressing force from.

  Further, since the spreader attached to the propulsion jack 11 is exchanged between when the inner mold 15 is pressed and when the segment 35 is pressed, the inner mold 15 and the segment 35 installed outside the inner mold 15 are arranged. The center of each end face can be pressed reliably.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, although the spreader used at the time of pressing each of the inner mold 15 and the segment 35 is replaced, it is not limited to this. FIG. 9 is an arrangement view of the propulsion jack 7 and the end form jack 11 as seen from the rear of the shield machine 1. As shown in FIG. 9A, the propulsion jack 7 and the end frame jack 11 are held on the inner surface of the skin plate 3 by a jack holding flange 45 formed substantially perpendicular to the axial direction of the shield machine 1. .

  A slide hole 43 is formed in the jack holding flange 45. The slide hole 43 is a substantially elliptical long hole, and has a shape that slightly protrudes from an end portion on the center direction side of the shield machine 1 (hereinafter simply referred to as a center direction end portion). The propulsion jack 7 is installed such that the rod of the propulsion jack 7 passes through the slide hole 43. When the inner mold 15 is pressed by the propulsion jack 7 (when the portion to be pressed by the propulsion jack 7 is a part away from the skin plate 3), the propulsion jack 7 is moved in the center direction of the slide hole 43. It is moved to the end side and fixed to the jack holding flange 45. At this time, the rod of the jack for propulsion 7 is arranged at a position shifted in the direction of the end of the slide hole 43 in the center direction. Even when the jack for propulsion 7 is installed on the end side in the center direction of the slide hole 43, the end in the center direction of the slide hole 43 is exposed at the end of the jack for propulsion 7. That is, even if the propulsion jack 7 is moved in the center direction of the shield machine 1, the end portion in the center direction of the slide hole 43 is not blocked, so that piping, wiring, and the like can be inserted into the slide hole 43.

  Similarly, when the segment 35 is pressed by the propulsion jack 7 (when the portion to be pressed by the propulsion jack 7 is a part close to the skin plate 3), the propulsion jack 7 is moved outward of the shield machine 1. To the jack holding flange 45 (in the direction of arrow K in the figure). At this time, the rod of the jack for propulsion 7 is arranged at a position shifted in the direction of the outer end of the slide hole 43 (end on the outer side of the shield machine 1). Even in this state, the end in the center direction of the slide hole 43 is not blocked, so that piping, wiring, and the like can be inserted into the jack holding flange 45.

  As described above, the propulsion jack 7 can be slid in the center direction of the shield machine 1 and outward, so that the shaft core of the spreader installed at the tip of the propulsion jack 7 is in the outer peripheral direction or the center direction of the shield machine 1. Can be decentered (moved).

  The eccentric movement of the spreader shaft core caused by the sliding movement of the propulsion jack 7 and the change of the eccentric amount of the spreader shaft core caused by the replacement of the spreader can also be used in combination. For example, if the inner mold frame and the pressed part of the segment are significantly different (when the eccentric amount is large), it cannot be handled by changing the spreader alone, and the amount of movement of the propulsion jack 7 is also limited. In such a case, it is possible to cope with a large amount of eccentricity by combining them.

DESCRIPTION OF SYMBOLS 1 ......... Shielding machine 3 ......... Skin plate 5 ......... Cutter head 7 ......... Propulsion jack 9 ......... Wive formwork 11 ... …… Wife formwork jack 13 ......... Screw conveyor 15 ... ... Inner mold 17 ... Concrete 18 ... Tail mold inner periphery seal 19 ... Inner mold spreader 21 ... Frozen pipe 23 ... Water stop 25 ... Ring member 27 ... ... tail seal 29 ......... taper segment 31 ......... temporary segment 33 ......... segment spreader 35 ......... segment 37 ......... mortar 39 ......... backing material 41 ......... inner form reaction force ring 43 ……… Slide hole 45 ……… Jack holding flange

Claims (11)

Tunnel construction method to switch from cast-in-place concrete method to segment method during excavation,
Propulsion jack provided in the skin plate, wife formwork used as a cast-in-place concrete formwork behind the shield machine, wife formwork jack capable of moving forward and backward in the formwork of the wife, and the wife mold Using a shield machine comprising a first seal part detachable from the inner surface of the frame and a second seal part detachable from the inner surface of the skin plate,
(A) constructing a tunnel by a cast-in-place concrete method using the inner mold and the wife mold as a mold while installing the inner mold;
(B) performing water stop near the rear end of the skin plate, and pulling the wife form frame back to the front of the shield machine by the wife form frame jack;
(C) removing the first seal part and moving the second seal part to the rear of the skin plate and joining the skin plate in the vicinity of the rear end by the wife formwork jack;
A step (d) of moving the first segment to the rear of the skin plate and joining the first segment to the outer periphery of the inner mold frame by the wife mold jack;
A step (e) of installing a second segment in front of the first segment to advance the shield machine and constructing a tunnel by a segment method;
The tunnel construction method characterized by comprising. The step (c) is a step of moving the wife mold frame and the second seal part rearward by the wife mold jack after installing the second seal part behind the wife mold frame. Yes,
In the step (d), the wife formwork is pulled back to the front of the shield machine by the wife formwork jack, and after the first segment is installed behind the wife formwork jack, A step of moving the wife formwork and the first segment to the rear of the skin plate by a jack;
In the step (e), the wife formwork is pulled back to the front of the shield machine by the wife formwork jack, and the propulsion jack is pressed against the first segment to advance the shield machine. Filling the outside of one segment with the first filler and pushing the propulsion jack against the second segment to advance the shield machine, while the second filling is carried out to the outside of the second segment The tunnel construction method according to claim 1, wherein the tunnel construction method is a step of filling a material. The shield machine further includes a ring member that is detachable from the inner surface of the skin plate and is slidable along the skin plate;
In the step (c), the ring member is installed behind the wife formwork, the second seal portion is installed behind the ring member, and the ring member and the A step of moving the second seal portion rearward of the skin plate;
In the step (d), the wife mold and the ring member are pulled back to the front of the shield machine by the wife mold jack, a first segment is installed behind the ring member, and the wife mold is used. The tunnel construction method according to claim 2, wherein the ring member and the first segment are moved to the rear of the skin plate by a jack. The shield machine comprises an embedded freezing tube provided near the rear end of the skin plate,
4. The tunnel according to claim 1, wherein the step (b) is a step of freezing and water-stopping a ground near the rear end of the skin plate by the embedded freezing pipe. Construction method. A spreader is attached to the tip of the propulsion jack,
The step (e) is a step of advancing the shield machine by decentering the axis of a spreader provided at the tip of the propulsion jack in the outer peripheral direction and pressing the propulsion jack against the first segment. The tunnel construction method according to any one of claims 1 to 4, wherein the tunnel construction method is provided.   6. The tunnel construction according to claim 5, wherein eccentricity of the shaft core of the spreader is performed by exchanging the spreader for the inner mold with a spreader for the segment eccentrically outward from the spreader for the inner mold. Method.   The tunnel construction method according to claim 5 or 6, wherein the eccentricity of the shaft core of the spreader is performed by sliding the jack for propulsion in the outer peripheral direction of the shield machine.   The said 1st filler is mortar, The said 2nd filler is a backfilling material whose intensity | strength is weaker than the said 1st filler, The any one of Claim 1-7 characterized by the above-mentioned. Tunnel construction method described in 2. The first segment is a segment having a tapered shape,
The step (d) is a step in which a temporary segment is provided in front of the first segment,
The step (e) is a step of moving the first segment rearward together with the temporary segment, separating the temporary segment and the first segment, and pulling the temporary segment back to the front of the shield machine. The tunnel construction method according to claim 1, wherein: A tunnel construction method that switches from a segment method to a cast-in-place concrete method during excavation,
Propulsion jack provided in the skin plate, wife formwork used as a cast-in-place concrete formwork behind the shield machine, wife formwork jack capable of moving forward and backward in the formwork of the wife, and the wife mold Using a shield machine comprising a first seal part detachable from the inner surface of the frame and a second seal part detachable from the inner surface of the skin plate,
While installing the second segment, filling the second filler outside the second segment and constructing the tunnel in a segmented manner (p);
A step (q) of performing waterstop near the rear end of the skin plate;
A step (r) of joining an inner mold reaction force ring to the inner periphery of the second segment, stopping water in the vicinity of the rear end of the skin plate, and removing the second seal portion from the skin plate; When,
While installing an inner mold in front of the inner mold reaction force ring, installing a first seal part on the inner surface of the wife mold, moving the wife mold near the rear end of the skin plate, Filling the outside of the second segment in the vicinity of the rear end of the skin plate with a first filler (s);
(T) constructing a tunnel by a cast-in-place concrete method using the inner formwork and the end formwork as a formwork;
The tunnel construction method characterized by comprising. A shield machine that can arbitrarily change the segment method and the cast-in-place concrete method while digging,
A jack for propulsion provided in the skin plate;
Wife formwork used as cast-in-place concrete formwork behind the shield machine,
A wife mold jack capable of moving back and forth the wife mold frame;
An embedded cryotube provided near the rear end of the skin plate;
A first seal portion detachably provided on the inner surface of the wife formwork;
A second seal portion detachably provided on the inner surface of the skin plate;
A ring member detachably attached to the inner surface of the skin plate and slidable along the skin plate;
A shield machine comprising:

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