Shield tunnel and construction method thereof

Abstract

To provide a shield tunnel and a construction method thereof, which can ensure that grout is reliably filled without leaving any air in the entire area of a sheath pipe extending in the circumferential direction.SOLUTION: A segment ring 20 is formed by connecting a number of segments 10 arranged in the circumferential direction via segment joints 12, and a number of segment rings 20 arranged in the axial direction of the tunnel are connected via ring joints 13 to form a shield tunnel 70. A sheath pipe 30 extending in the circumferential direction is buried inside the segment ring 20, a tension member 40 is placed inside the sheath pipe 30 and is filled with grout g, a branch section 32 is provided in a part of the sheath pipe 30, a first exhaust pipe 52 leading to an inner space side of the segment ring 20 is connected to the branch section 32, and at least a midpoint 52a of the first exhaust pipe 52 is at a height position equal to or higher than the highest position of the sheath pipe 30.SELECTED DRAWING: Figure 7A

Description

[Technical field]

[0001] The present invention relates to a shield tunnel and a construction method thereof. [Background technology]

[0002] Shield tunnels are often constructed using the shield method, using steel segments, RC (Reinforced Concrete) segments, or composite segments made of steel and concrete, but P&PC (Prestressed & Precast) segments may also be used as an alternative form. A shield tunnel using these P&PC segments is constructed by assembling concrete (including reinforced concrete) segments into one ring to form a segment ring, inserting tension members such as PC steel strands into the sheath tubes that extend circumferentially inside the segment ring to tension and secure it, and connecting the segment rings while forming such segment rings sequentially in the longitudinal direction of the tunnel. Here, the connection between the segment rings can also be done by inserting tension members into the sheath tubes that extend in the axial direction of the tunnel that communicate with each segment ring, and securing them under tension. In this P&PC segment, a method is also available in which tendons are inserted inside the sheath pipe and tensioned and then the inside of the sheath pipe is filled with grout to form a segment ring.

[0003] In a shield tunnel consisting of P&PC segments in which the sheath pipes are filled with grout, it is essential that any air remaining in the sheath pipes is removed and that the entire area of ​​the sheath pipes extending circumferentially around the segment ring is reliably filled with grout. However, a shield tunnel consisting of P&PC segments that can guarantee that no air remains in the entire circumferentially extending sheath pipe and that grout is reliably filled has not yet been established, and therefore such a shield tunnel is desirable.

[0004] Here, Patent Document 1 proposes a shield tunnel lining for a shield tunnel formed by the above-mentioned P&PC segments. Specifically, a number of segments made of reinforced concrete are assembled circumferentially to form a ring, and a number of sets of this ring-shaped segment assembly are connected in the direction of its central axis to form a shield tunnel lining, with cutouts provided on the inner surface of the segments for fixing the PC steel, and one end of the PC steel arranged in the direction of the central axis within the shield tunnel lining is fixed within the cutout, and the other end of the PC steel is fixed within a cutout provided on the inner surface of the rear or front segment, separated by one or more segment assemblies in the direction of the central axis. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-81891 Summary of the Invention [Problem to be solved by the invention]

[0006] The shield tunnel lining described in Patent Document 1 is said to improve the work efficiency when introducing axial prestress. However, Patent Document 1 does not disclose the above-mentioned problem, that is, a means for ensuring that the entire area of ​​the sheath pipe extending in the circumferential direction is reliably filled with grout without leaving any air therein.

[0007] The present invention relates to a shield tunnel formed by connecting a plurality of segment rings in the axial direction of the tunnel, in which a plurality of segments arranged circumferentially are integrated by tendons inserted into a sheath tube and the inside of the sheath tube is filled with grout, and the object of the present invention is to provide a shield tunnel and a construction method thereof that can ensure that grout is reliably filled throughout the entire sheath tube extending in the circumferential direction without any air remaining therein. [Means for solving the problem]

[0008] In order to achieve the above object, one aspect of the shield tunnel according to the present invention is as follows: A shield tunnel formed by connecting a plurality of segments arranged in a circumferential direction via segment joints to form a segment ring, and connecting a plurality of the segment rings arranged in an axial direction of the tunnel via ring joints, A sheath tube is embedded inside the segment ring and extends in a circumferential direction thereof, and a tension member is disposed inside the sheath tube and filled with grout; a branched portion is provided in a part of the sheath tube, and a first exhaust pipe that is connected to the branched portion and leads to an inner space side of the segment ring, At least a midpoint of the first exhaust pipe is at a height position equal to or higher than the highest position of the sheath tube.

[0009] According to this aspect, a first exhaust pipe leading to the inner space of the segment ring is connected to a branch portion provided on the sheath tube extending circumferentially around the segment ring, and at least a midpoint of the first exhaust pipe is located at a height position equal to or higher than the highest point of the sheath tube. This makes it possible to reliably exhaust air inside the sheath tube to the inner space of the segment ring during the process of filling the sheath tube with grout, thereby ensuring that the entire area of ​​the sheath tube extending circumferentially is reliably filled with grout without any air remaining therein.

[0010] Here, "at least an intermediate position of the first exhaust pipe is at a height position equal to or higher than the highest point of the sheath tube" means that when the first exhaust pipe extends upward from the attachment position with the branching section and then descends downward, for example having an inverted U-shape or inverted V-shape, any position of the first exhaust pipe (which may be the highest point of the inverted U-shape or inverted V-shape, or any position lower than the highest point) is at a height position equal to or higher than the highest point of the sheath tube. Ultimately, complete removal of air from the sheath tube is confirmed by the discharge of grout from the first exhaust pipe. By discharging grout from the first exhaust pipe, which passes at a higher position than the sheath tube into which the grout is filled, it is possible to ensure that air is completely removed from the sheath tube and that the entire sheath tube is reliably filled with grout without any gaps.

[0011] In another aspect of the shield tunnel according to the present invention, The branched portion is a branched tube that protrudes laterally from an upper region of the sheath tube in a cross section perpendicular to the longitudinal direction of the sheath tube.

[0012] According to this aspect, the branching part projects out to the side of the sheath tube from the upper region in a cross section perpendicular to the longitudinal direction of the sheath tube, and the first exhaust pipe is attached to one end of this branching part, so that an air exhaust route can be formed that passes through a position higher than the highest position of the sheath tube and leads to the inner space of the tunnel without impeding the circumferential extension of the sheath tube. Furthermore, if the branching part is in the upper region of the sheath tube, it is possible to ensure that the air is completely exhausted from the sheath tube to the branching part. Here, the "upper region" means the top of the sheath tube, diagonally above the sheath tube, etc.

[0013] Another aspect of the shield tunnel according to the present invention is a connecting pipe to which an end of the first exhaust pipe is connected and a steel plate having a through hole through which the connecting pipe communicates are integrated and embedded inside the segment, A female screw is fixed around the through hole on the inner hollow side of the steel plate, A second exhaust pipe is attached to the through hole, the second exhaust pipe extending further into the inner space than the female thread.

[0014] According to this aspect, the connecting pipe to which the end of the first exhaust pipe is connected and the steel plate having a through hole through which the connecting pipe communicates are integrated and embedded inside the segment, and the second exhaust pipe that protrudes further toward the inner space side than the female thread around the through hole on the inner space side of the steel plate is attached in a manner that communicates with the through hole, thereby preventing the grout from adhering to the female thread when the grout is finally discharged. Here, the male thread of a plug having a male thread is screwed into the female thread after filling with grout, and the recess formed by the female thread etc. is closed with the plug.

[0015] In another aspect of the shield tunnel according to the present invention, The second exhaust pipe is characterized in that it is formed by a joint pipe attached to the through hole and a hose attached to the joint pipe.

[0016] According to this aspect, the second exhaust pipe is formed by a joint pipe attached to the through hole of the steel plate and a hose attached to the joint pipe, so that the second exhaust pipe can be easily attached to the through hole of the steel plate and easily removed from the through hole. Furthermore, by adjusting the length of the hose in various ways, the tip of the hose can be positioned at a desired position inside the shield tunnel where a worker can easily check the discharge of grout.

[0017] Another aspect of the shield tunnel according to the present invention is a connecting pipe to which an end of the first exhaust pipe is connected and a steel plate having a through hole through which the connecting pipe communicates are integrated and embedded inside the segment, A female screw is fixed around the through hole on the inner hollow side of the steel plate, A plug having a male thread is screwed into the female thread.

[0018] According to this aspect, a plug having a male thread is screwed into a female thread fixed around the through hole on the inner space side of the steel plate, so that the recess formed by the female thread or the like can be blocked by the plug, and the inner surface of the plug can be made flush with the inner surface of the segment ring, for example. For example, when the shield tunnel is a storm water main line or the like, it is preferable to make the inner surface of the shield tunnel a flush curved surface without any recesses, since this can prevent the occurrence of turbulence due to the recesses.

[0019] In addition, one aspect of the shield tunnel construction method according to the present invention is to A shield tunnel construction method comprising the steps of: forming a segment ring by connecting a plurality of segments arranged in a circumferential direction via segment joints; arranging a plurality of the segment rings in the axial direction of a tunnel; and connecting the segment rings to each other via ring joints to construct a shield tunnel, A tension filling process includes inserting a tension material into a sheath tube that is embedded inside the segment ring and extends in a circumferential direction thereof to tension the sheath tube, and then filling the sheath tube with grout from a filling port located below the sheath tube, In the tension filling step, air moving inside the sheath tube when the inside of the sheath tube is filled with grout is exhausted to the inner space side of the segment ring through a first exhaust pipe connected to a branch portion provided in a part of the sheath tube and leading to the inner space side of the segment ring, At least a midpoint of the first exhaust pipe is at a height position equal to or higher than the highest position of the sheath tube.

[0020] According to this aspect, a first exhaust pipe leading to the inner space of the segment ring is connected to a branch portion provided on the sheath tube extending circumferentially around the segment ring, and at least a midpoint of the first exhaust pipe is located at a height position equal to or higher than the highest point of the sheath tube. This makes it possible to reliably exhaust air inside the sheath tube to the inner space of the segment ring during the process of filling the sheath tube with grout, thereby ensuring that the entire area of ​​the sheath tube extending circumferentially is reliably filled with grout without any air remaining therein.

[0021] Another aspect of the shield tunnel construction method according to the present invention is as follows: The method is characterized in that after grout is discharged from the discharge port of the sheath tube opposite the filling port, grout is discharged from the first exhaust pipe into the inner space of the segment ring, thereby confirming that the air inside the sheath tube has been removed and that the entire circumference of the sheath tube has been filled with grout.

[0022] According to this embodiment, after grout is discharged from the discharge port opposite the filling port, grout is discharged from the first exhaust pipe into the inner space side of the segment ring, thereby ensuring that grout is reliably filled throughout the entire area of ​​the sheath tube extending circumferentially without any air remaining.

[0023] Another aspect of the shield tunnel construction method according to the present invention is as follows: After the sheath tube is filled with grout up to the branching portion, grout is discharged from the first exhaust pipe, and then grout is discharged from the discharge port opposite the filling port, thereby confirming that the air inside the sheath tube has been removed and that the entire circumference of the sheath tube has been filled with grout.

[0024] According to the present embodiment, after the grout is filled into the sheath tube up to the branching portion, the grout is discharged from the first exhaust pipe, and then the grout is discharged from the discharge port opposite the filling port, thereby ensuring that the grout is reliably filled into the entire area of ​​the sheath tube extending circumferentially without any air remaining. Effect of the Invention

[0025] According to the shield tunnel and its construction method of the present invention, for a shield tunnel formed by integrating a plurality of segments arranged circumferentially with tendons arranged in a sheath tube, filling the inside of the sheath tube with grout to form segment rings, and connecting a plurality of segment rings in the axial direction of the tunnel, it is possible to ensure that grout is reliably filled throughout the entire sheath tube extending circumferentially with no air remaining. [Brief description of the drawings]

[0026] [Figure 1] FIG. 2 is a development view of an inner surface of a portion of an example of a shield tunnel according to an embodiment. [Diagram 2] FIG. 2 is a longitudinal cross-sectional view of a set of segment rings constituting the shield tunnel according to the embodiment. [Diagram 3] FIG. 11 is a longitudinal cross-sectional view of a second set of segment rings constituting the shield tunnel according to the embodiment. [Figure 4] FIG. 4 is a view taken along the line IV-IV in FIG. [Diagram 5] FIG. 3 is an enlarged view of part V in FIG. 2. [Figure 6] 6 is a view taken along the line VI-VI in FIG. 2. [Figure 7A] 7 is a view taken along line VII-VII in FIG. 6, and is a vertical cross-sectional view of the exhaust part when the sheath tube is being filled with grout. [Figure 7B] 7 is a view taken along the line VII-VII in FIG. 6, and is a vertical cross-sectional view of the exhaust part when filling of the sheath tube with grout is completed. [Figure 8] FIG. 1 is a process diagram illustrating a shield tunnel construction method according to an embodiment, with reference to an exhaust section. [Figure 9] 8, this is a process diagram illustrating the shield tunnel construction method according to the embodiment with reference to the exhaust unit. [Figure 10] 9, this is a process diagram illustrating the shield tunnel construction method according to the embodiment with reference to the exhaust unit. [Figure 11]10, this is a process diagram illustrating the shield tunnel construction method according to the embodiment with reference to the exhaust section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, a shield tunnel and a construction method thereof according to an embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially identical components are designated by the same reference numerals to avoid redundant description.

[0028] [Shield tunnel according to the embodiment and its construction method] An example of a shield tunnel and a construction method thereof according to an embodiment will be described with reference to Figs. 1 to 13 . Here, Fig. 1 is an internal development view of a part of an example of a shield tunnel according to the embodiment, and Fig. 2 and Fig. 3 are vertical cross-sectional views of a set of segment rings of a first group and a set of segment rings of a second group, which constitute a shield tunnel according to the embodiment. Fig. 4, Fig. 5, and Fig. 6 are respectively a view taken along the line IV-IV in Fig. 2, an enlarged view of part V in Fig. 2, and a view taken along the line VI-VI in Fig. 2. Fig. 7A is a view taken along the line VII-VII in Fig. 6, which is a vertical cross-sectional view of an exhaust section when grout is being filled into a sheath tube, and Fig. 7B is a view taken along the line VII-VII in Fig. 6, which is a vertical cross-sectional view of an exhaust section when filling of grout into a sheath tube is completed. Figs. 8 to 11 are process diagrams for explaining a construction method of a shield tunnel according to the embodiment with reference to the exhaust section.

[0029] The shield tunnel 70 shown in Figure 1 is a tunnel formed by connecting multiple segment rings 20 to each other via ring joints 13 in the axial direction of the tunnel, and Figure 1 illustrates three of these segment rings 20.

[0030] Here, the illustrated shield tunnel 70 is applied as, for example, an underground river tunnel, and is a storm water main tunnel through which storm water is stored or circulated inside the shield tunnel 70. The shield tunnel 70 may have a use other than as a storm water main tunnel.

[0031] The segment ring 20 has an A-group segment ring 20A and a B-group segment ring 20B. Both the A-group segment ring 20A and the B-group segment ring 20B include a plurality of (four in the illustrated example) A-segments 10A, two B-segments 10B, and a K-segment 10C that is sandwiched between the two B-segments 10B and finally fitted in place. Adjacent segments 10 are connected to each other via segment joints 12 (see FIG. 4), and the segment ring 20 is formed by tensioning the tension material 40 inserted through the circumferentially extending sheath tube 30.

[0032] As shown in FIG. 1, the first segment ring 20A and the second segment ring 20B are alternately arranged, and the two are connected with their segment joints offset from one another.

[0033] A plurality of sheath tubes 30A, 30B (two in the illustrated example as shown in FIG. 4) are embedded inside each segment ring 20 and extend in the circumferential direction, and a tendon 40 made of PC steel strand is inserted inside each sheath tube 30 and tensioned, and furthermore, each sheath tube 30 is filled with grout. Here, the segment ring 20 in the illustrated example has two sheath tubes 30A, 30B inside, but it may also be in a form in which, for example, one sheath tube is provided at the width center position of the segment ring 20.

[0034] As shown in Figures 1 to 3, both the A segment ring 20A and the B segment ring 20B have a grout filling position P1 set at or near their bottoms, and an exhaust position P2 set at or near their tops in the upper region.

[0035] The A-group segment ring 20A and the B-group segment ring 20B are connected to each other with their segment joints offset, which enhances the earthquake resistance of the shield tunnel 70 in the ground G. Also, because both segment joints are offset in this manner, the A-group segment ring 20A shown in Fig. 2 has an exhaust position P2 located to the left of the center line CL, whereas the B-group segment ring 20B shown in Fig. 3 has an exhaust position P2 located to the right of the center line CL, but both exhaust positions P2 are set in the upper region near the top of the segment ring 20. Note that Figs. 2 and 3 also show the center line CL and the spring line SL perpendicular to it.

[0036] As shown in FIG. 4, an erector hole 14 is provided at the center of each segment 10, and two sheath tubes 30A, 30B extending in the circumferential direction are arranged on either side of the erector hole 14.

[0037] 4 is an A-segment 10A located at the bottom of the segment ring 20, and a pair of tendon insertion grooves 15 is provided on the surface on the inner space side of the segment 10A at positions corresponding to both ends of each sheath tube 30. A tendon 40 is inserted into the inside of the sheath tube 30 through one tendon insertion groove 15, and an end of the tendon 40 is pulled out through the other tendon insertion groove 15. Both ends of the tendon 40 are fixed to the wall surface of the tendon insertion groove 15 through tendon fixing hardware 45.

[0038] 5, in the A segment 10A located at the bottom of the segment ring 20, in addition to the position where the tendon 40 is tensioned, a grout filling position P1 where grout is filled from the end of the sheath tube 30 is set. That is, as shown in FIG. 5, one end of the sheath tube 30 serves as a grout filling port 35, and the other end serves as a discharge port 36 from which the grout is discharged after being filled into the entire area of ​​the sheath tube 30.

[0039] On the other hand, as shown in FIG. 6, an exhaust section 50 is formed at the exhaust position P2 of the K segment 10C at the top of the segment ring 20 by connecting two first exhaust pipes 52 (dotted lines in FIG. 6) attached to the branching sections 32 of the two sheath tubes 30.

[0040] The exhaust unit 50 is a mechanism for exhausting air present inside the sheath tube 30 during the process of filling the sheath tube 30 with grout. The exhaust unit 50 has a different structure when the sheath tube 30 is being filled with grout and when filling of the sheath tube 30 with grout is completed. The structures of both exhaust units 50 will be described below with reference to Figures 7A and 7B.

[0041] First, the exhaust section 50 shown in FIG. 7A is an exhaust section when the sheath tube 30 is being filled with grout.

[0042] A branch pipe 32 branches off from each of the two sheath tubes 30A, 30B at a midpoint so as to protrude laterally from the upper region in a cross section perpendicular to the longitudinal direction of the sheath tube 30, and one end of a first exhaust pipe 52 having a linear shape in a substantially inverted U-shape is fixed to this branch pipe 32.

[0043] On the other hand, a recess 16 is provided on the surface on the inner space side of the K segment 10C, and a connection unit 56 is embedded in a position corresponding to the recess 16. This connection unit 56 has a steel plate 53 in which two through holes 53a are formed, a connection pipe 54 fixed to one wide surface of the steel plate 53 at a position corresponding to each of the through holes 53a, and a cylindrical female screw 55 provided on the other wide surface of the steel plate 53 at a position surrounding the two through holes 53a.

[0044] The connection unit 56 is embedded so that the hollow of the female screw 55 communicates with the recess 16 of the K segment 10C. Ends of the first exhaust pipe 52 are connected to two connection pipes 54 that communicate with the two through holes 53a of the steel plate 53, respectively.

[0045] Here, the first exhaust pipe 52 is formed, for example, from a pressure-resistant vinyl hose, a steel pipe, etc. Also, the connecting pipe 54 and the female screw 55 are formed from steel pipes of different diameters, and the female screw 55 has a thread groove formed on its inner surface facing the hollow.

[0046] Two through holes 53a in the steel plate 53 face the recess 16 of the K segment 10C facing the inner space side of the segment ring 20, and one end of a joint pipe 57 is connected to each through hole 53a via the recess 16 and a female screw 55, and a hose 58 is connected to the other end of the joint pipe 57, and the tip of the hose 58 is attached so as to protrude toward the inner space side of the segment ring 20 beyond the recess 16. Here, a second exhaust pipe 59 is formed by the joint pipe 57 and the hose 58, and the hose 58 is formed from, for example, a vinyl hose or the like.

[0047] The positions of the sheath tubes 30B and 30A shown in FIG. 7A are at a level L1 which is the highest position in the linear arrangement in which they extend in the circumferential direction of the segment ring 20.

[0048] In the exhaust section 50, at least a midway position 52a of the first exhaust pipe 52 is set to pass through a level L2 that is a height position equal to or higher than a level L1 that is the highest position of the sheath tube 30.

[0049] In this way, since the midpoint 52a of the first exhaust pipe 52 is located at a height position equal to or higher than the highest position of the sheath tube 30, air present inside the sheath tube 30 can be reliably exhausted to the inner space side of the segment ring 20 during the process of filling the sheath tube 30 extending circumferentially around the segment ring 20 with grout, and it can be ensured that the entire area of ​​the sheath tube 30 extending circumferentially around the segment ring 20 is reliably filled with grout without any air remaining therein.

[0050] In the process of filling the grout, for example, after the grout has been filled into the entire area of ​​the sheath tube 30 extending circumferentially around the segment ring 20, as the grout flows in the X1 direction through the branch tube 32, the first exhaust pipe 52, the connection unit 56 and the second exhaust pipe 59, the air is exhausted by being pushed into the inner space of the segment ring 20 by the grout.

[0051] After air has been exhausted from inside the sheath tube 30 extending circumferentially around the segment ring 20 and the entire area has been filled with grout, the second exhaust pipe 59 is then removed from the recess 16, and as shown in FIG. 7B, a plug 60 having a male thread 62 is screwed into the female thread 55, thereby completely blocking the recess 16 with the plug 60.

[0052] Since the shield tunnel 70 in the illustrated example is a tunnel through which rainwater flows as described above, it is preferable that the inner surfaces of the segment ring 20 and the inner surfaces of the plug 60 are flush curved surfaces as shown in FIG. 7B, which can prevent the occurrence of turbulence and the like caused by the presence of depressions.

[0053] Next, a shield tunnel construction method according to the embodiment will be described with reference to Figs.

[0054] First, as shown in FIG. 8, in the exhaust section 50, the steel plate 53 faces the inner space of the segment ring 20 via the recess 16 and the hollow of the female thread 55. Then, as shown in FIG. 9, the joint pipes 57 of the second exhaust pipe 59 are connected to the two through holes 53a of the steel plate 53, and the hose 58 of the second exhaust pipe 59 is caused to extend into the inner space.

[0055] Next, the tensioning material 40 is inserted into the two sheath tubes 30 and tensioned, and then grout is filled through the filling ports 35 (see Figure 4) of each sheath tube 30. During the process of filling the grout, the air present inside the sheath tubes 30 is exhausted through the exhaust section 50 to the inner space side of the segment ring 20.

[0056] Here, there are two modes for the timing of filling the entire area of ​​the sheath tube 30 extending in the circumferential direction of the segment ring 20 with grout and discharging the air.

[0057] In the first mode, after grout is discharged from the discharge port 36 on the opposite side of the filling port 35 of the sheath tube 30, the grout g flows through the first exhaust pipe 52 in the X1 direction as shown in Figure 10, and air is exhausted when the grout g is discharged in the X1 direction from the exhaust section 50 into the inner space of the segment ring 20.

[0058] In this embodiment, by confirming that the grout g has been discharged from the discharge port 36 of the sheath tube 30 and then confirming that the grout g has been discharged from the exhaust section 50, it is possible to ensure that the air inside the sheath tube 30 has been completely removed and that the entire area of ​​the sheath tube 30 has been reliably filled with grout g.

[0059] On the other hand, the second mode is a mode in which, after the grout g is filled up to the branching section 32 of the sheath tube 30 (for example, after it is filled up to about half the total length of the sheath tube 30), the grout g flows through the first exhaust pipe 52 in the X1 direction as shown in Figure 10, and the grout g is discharged from the exhaust section 50 to the inner space side of the segment ring 20 in the X1 direction, and then the grout is discharged from the discharge port 36.

[0060] This is due to the flow pattern of grout g, which occurs when the frictional resistance is too large when filling the entire sheath tube 30 with grout, and which occurs when the grout flows from the branch pipe 32 to the first exhaust pipe 52 before the entire sheath tube 30 is filled with grout in advance.

[0061] In this embodiment, by confirming that the grout g has been discharged from the exhaust section 50 and then confirming that the grout g has been discharged from the discharge port 36 of the sheath tube 30, it is possible to ensure that the air inside the sheath tube 30 has been completely removed and that the grout g has been reliably filled throughout the entire sheath tube 30.

[0062] In either embodiment, it is possible to ensure complete removal of air from the sheath tube 30 and reliable filling of grout into the entire area of ​​the sheath tube 30 (this is the tension filling process).

[0063] Finally, as shown in FIG. 11, the second exhaust pipe 59 is removed from the recess 16, and a plug 60 is screwed into the female thread 55 to close the recess 16, thereby installing the segment ring 20.

[0064] According to the shield tunnel construction method of the illustrated example, it is possible to ensure that no air remains in the entire area of ​​the sheath tube 30 extending circumferentially around the segment ring 20 and that grout g is reliably filled, which can be a construction method for a shield tunnel made of new P&PC segments that is not currently established.

[0065] Here, as shown in Figure 9, the hose 58 extends from the recess 16 into the inner space of the segment ring 20, and grout g is discharged from the tip of the hose 58, which prevents the discharged grout g from coming into contact with the female thread 55 or the recess 16 and hardening, making it impossible to install the plug 60.

[0066] In addition, by extending the tip of the hose 58 to a position where it is easily visible to the worker, it is easy to confirm that grout g is being discharged from the tip of the hose 58 even if the inside of the shield tunnel 70 is dark.

[0067] A shield tunnel 70 is constructed by sequentially connecting a plurality of segment rings 20 in the axial direction of the tunnel.

[0068] In addition, the present invention is not limited to the configuration shown here, and may be implemented in other embodiments in which other components are combined with the configurations and the like of the above-mentioned embodiment. In this regard, the present invention may be modified within the scope of the gist of the present invention, and may be appropriately determined according to the application form. [Explanation of symbols]

[0069] 10: Segment 10A: A segment (segment) 10B: B segment (segment) 10C: C segment (segment) 12: Segment joint 13: Ring joint 14: Erector hole 15: Tendon insertion groove 16: Recess 20: Segment ring 20A: Class A segment ring (segment ring) 20B: B-group segment ring (segment ring) 30, 30A, 30B: Sheath tube 32: Branch section (branch pipe) 35:Filling port 36:Discharge port 40: Tendon (PC steel strand) 45: Tendon fixing hardware 50: Exhaust section 52: First exhaust pipe 52a: midway position 53: Steel plate 53a: Through hole 54: Connecting pipe 55: Female thread 56: Connection unit 57: Joint pipe 58: Hose 59: Second exhaust pipe 60: Plug 62: Male thread 70: Shield Tunnel P1: Grout filling position P2: Exhaust position SL: Spring Line CL: Center Line G: Ground g: Grout

Claims

1. A shield tunnel formed by connecting a plurality of segments arranged in a circumferential direction via segment joints to form a segment ring, and connecting a plurality of the segment rings arranged in an axial direction of the tunnel via ring joints, A sheath tube is embedded inside the segment ring and extends in a circumferential direction thereof, and a tension member is disposed inside the sheath tube and filled with grout; a branched portion is provided in a portion of the sheath tube, and a first exhaust pipe is connected to the branched portion, the first exhaust pipe being connected to an inner space side of the segment ring; A shield tunnel, characterized in that at least a midpoint of the first exhaust pipe is at a height position equal to or higher than a highest position of the sheath pipe.

2. 2. The shield tunnel according to claim 1, wherein the branch portion is a branch pipe that protrudes laterally from an upper region of the sheath tube in a cross section perpendicular to the longitudinal direction of the sheath tube.

3. a connecting pipe to which an end of the first exhaust pipe is connected and a steel plate having a through hole through which the connecting pipe communicates are integrally formed and embedded inside the segment, A female screw is fixed around the through hole on the inner hollow side of the steel plate, 2. The shield tunnel according to claim 1, wherein a second exhaust pipe is attached to the through hole, the second exhaust pipe extending further toward the inner space than the female thread.

4. 4. The shield tunnel according to claim 3, wherein the second exhaust pipe is formed by a joint pipe attached to the through hole and a hose attached to the joint pipe.

5. a connecting pipe to which an end of the first exhaust pipe is connected and a steel plate having a through hole through which the connecting pipe communicates are integrally formed and embedded inside the segment, A female screw is fixed around the through hole on the inner hollow side of the steel plate, 2. The shield tunnel according to claim 1, wherein a plug having a male thread is screwed into the female thread.

6. A shield tunnel construction method comprising the steps of: forming a segment ring by connecting a plurality of segments arranged in a circumferential direction via segment joints; arranging a plurality of the segment rings in the axial direction of a tunnel; and connecting the segment rings to each other via ring joints to construct a shield tunnel, A tension filling process includes inserting a tension material into a sheath tube that is embedded inside the segment ring and extends in a circumferential direction thereof to tension the sheath tube, and then filling the sheath tube with grout from a filling port located below the sheath tube, In the tension filling step, air moving inside the sheath tube when the inside of the sheath tube is filled with grout is exhausted to the inner space side of the segment ring through a first exhaust pipe connected to a branch portion provided in a part of the sheath tube and leading to the inner space side of the segment ring, A shield tunnel construction method, characterized in that at least a midpoint of the first exhaust pipe is at a height position equal to or higher than the highest position of the sheath pipe.

7. 7. The shield tunnel construction method according to claim 6, characterized in that after grout is discharged from a discharge port of the sheath tube opposite to the filling port, grout is discharged from the first exhaust pipe into the inner space of the segment ring, thereby confirming that air has been removed from inside the sheath tube and that the entire circumference of the sheath tube has been filled with grout.

8. 7. The shield tunnel construction method according to claim 6, wherein after the grout has been filled into the sheath tube up to the branching portion, grout is discharged from the first exhaust pipe, and then the grout is discharged from a discharge port opposite to the filling port, thereby confirming that air has been removed from inside the sheath tube and that the entire circumference of the sheath tube has been filled with grout.

Images