Method for replacing tail seal of shield tunneling machine

Abstract

To provide a method to replace a tail seal of a shield excavator, which enables a tunnel with a small bending radius to be constructed.SOLUTION: An excavator body is promoted forward by elongation of a rod 15a of a plurality of shield jacks 15 using an existing segment ring 30 consisting of pieces divided in a circumferential direction as a reaction receiver, and a new segment ring is sequentially installed in front of the existing segment ring 30 to construct a tunnel. A tail seal 61, which is disposed on a rear part of a skin plate 10 of the excavator body and seals between an inner peripheral surface of the skin plate 10 and an outer peripheral surface of the existing segment ring 30, is replaced during construction of the tunnel. A piece 32 located on an inner side of the tail seal 61 to be replaced is fixed to a spreader of the rod 15a of the shield jack 15. The piece 32 is pulled out forward by contracting the rod 15a and the tail seal 61 to be replaced is replaced through a space S generated by pulling out the piece 32.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for replacing the tail seal of a shield tunneling machine.

Background Art

[0002] To construct a tunnel, a shield tunneling machine is used that repeats, for each ring, excavating the ground at the front end of the tunneling machine body and assembling a segment ring at the rear of the tunneling machine body. In a shield tunneling machine, a tail seal such as a tail brush is provided to prevent water leakage from the gap between the inner peripheral surface of the rear part of the body of the tunneling machine and the outer peripheral surface of the segment ring.

[0003] When constructing a long-distance tunnel, the tail seal may deteriorate or be damaged, which may cause problems such as segment ring defects and abnormal jack thrust. Therefore, it has been necessary to replace the tail seal during tunnel excavation.

[0004] Therefore, Patent Document 1 discloses a technique in which, with a new tail seal ring fixed to the front end of the original tail seal ring, the rod of the shield jack is extended to move these tail seal rings backward, and then the rod is shortened to remove the original tail seal ring.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the technique described in Patent Document 1 above, the stroke of the rod of the shield jack must be longer than the length of the tail seal ring. However, in this case, there is a problem that a tunnel with a small bending radius cannot be constructed.

[0007] In view of the above points, an object of the present invention is to provide a method for replacing a tail seal of a shield tunneling machine capable of constructing a tunnel with a small bending radius.

Means for Solving the Problems

[0008] The method for replacing the tail seal of the shield tunneling machine of the present invention is to propel the tunneling machine body toward the face side by extending the rods of a plurality of propulsion jacks using an existing segment ring composed of pieces divided in the circumferential direction as a reaction force receiver, and sequentially installing new segment rings on the face side of the existing segment ring to construct a tunnel. During this process, a method for replacing a tail seal provided at the rear part of the body of the tunneling machine body and sealing between the inner circumferential surface of the body and the outer circumferential surface of the existing segment ring, wherein at least one piece of the pieces constituting the existing segment ring located inside the tail seal to be replaced is fixed to a spreader of the rod of at least one of the plurality of propulsion jacks, and the rod is contracted to pull out the piece toward the face side, and the tail seal to be replaced is replaced through the space generated by the pulling out of the piece.

[0009] According to the method for replacing the tail seal of the shield tunneling machine of the present invention, a piece located inside the tail seal to be replaced is pulled out toward the face side by contracting the rod of the propulsion jack, and the tail seal is replaced through the space generated by this pulling out. As a result, the amount of rod contraction required for replacing the tail seal only needs to be such that a space where the tail seal can be replaced can be formed. Compared with the technique described in Patent Document 1 above, it is possible to suppress the rod stroke and construct a tunnel with a small bending radius.

[0010] In the method for replacing the tail seal of the shield tunneling machine of the present invention, after pulling out the at least one piece located inside the tail seal to be replaced, the piece and the piece adjacent in the circumferential direction are fixed to the spreader of the rod of at least one other propulsion jack among the plurality of propulsion jacks, and it is preferable to pull out the piece toward the face side by contracting the rod.

[0011] In this case, since the pieces constituting the segment ring located inside the tail seal to be replaced are sequentially pulled out, compared with the case of pulling out the entire segment ring, it is possible to partially perform operations such as water stop, and it is possible to suppress water stop and the like.

[0012] Also, in the method for replacing the tail seal of the shield tunneling machine of the present invention, the at least one piece located inside the tail seal to be replaced and the piece adjacent to the piece in the circumferential direction are fixed, and at least one of these pieces is fixed to the spreader of the rod of at least one propulsion jack among the plurality of propulsion jacks, and it is preferable to pull out these pieces toward the face side simultaneously by contracting the rod.

[0013] In this case, since the plurality of pieces constituting the segment ring located inside the tail seal to be replaced are pulled out simultaneously, compared with the case of pulling out the pieces one by one, the pulling-out operation can be simplified.

[0014] Also, in the method for replacing the tail seal of the shield tunneling machine of the present invention, the at least one piece located inside the tail seal to be replaced is fixed to the piece located on the face side of the piece, and the piece located on the face side is fixed to the spreader of the rod of at least one propulsion jack among the plurality of propulsion jacks, and it is preferable to pull out these pieces toward the face side simultaneously.

[0015] In this case, even if another piece is located on the face side of the piece positioned inward of the tail seal to be replaced, it is possible to replace the tail seal, and it is possible to replace tail seals with a larger number of stages.

[0016] Also, in the method for replacing the tail seal of the shield tunneling machine of the present invention, after pulling out the at least one piece located inward of the tail seal to be replaced, a spacer is interposed between the piece and the piece located on the shaft side of the piece, and then at least one of the pieces of the piece and the piece adjacent in the circumferential direction is fixed to the spreader of the rod of at least one of the plurality of propulsion jacks, and it is preferable to pull out the piece to the face side by contracting the rod.

[0017] In this case, by interposing a spacer between the pieces, it is possible to stabilize these pieces.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying out the Invention

[0019] The shield tunneling machine 100 used when implementing the method for replacing the tail seal of the shield tunneling machine according to the embodiment of the present invention will be described with reference to the drawings.

[0020] As shown in FIG. 1, the shield tunneling machine 100 includes a skin plate (shield cylinder) 10 and an excavation unit 20 assembled to the skin plate 10. The skin plate 10 is composed of a front skin plate (front body) 11 and a rear skin plate (rear body) 12. The skin plate 10 and the excavation unit 20 correspond to the excavation machine body of the present invention, and the skin plate 10 corresponds to the body of the present invention.

[0021] At the front end of the rear skin plate 12, a spherical joint portion 13 that fits into the rear end portion of the front skin plate 11 is provided, and the front skin plate 11 can be bent in any direction with respect to the rear skin plate 12. A plurality of middle folding jacks 14 that connect the front skin plate 11 and the rear skin plate 12 are provided at circumferential intervals, and the direction of the front skin plate 12, that is, the advancing direction of the shield tunneling machine 100, can be adjusted by these middle folding jacks 14.

[0022] A plurality of propulsion jacks (shield jacks) 15 for advancing the shield tunneling machine 100 with the existing segment ring 30 as a reaction force receiver are attached to the rear skin plate 12 at circumferential intervals.

[0023] Inside the rear skin plate 12, referring also to FIG. 2, an erector 50 for assembling a ring-shaped segment ring 31 or the like with pieces 41 or the like on the inner wall surface of the excavated tunnel is arranged.

[0024] Using the existing segment ring 30 as a reaction force receiver, the main body of the excavator is advanced by the propulsion jack, and a new segment ring is installed between the rear (shaft sinking side) of the propulsion jack 15 and the tip of the existing segment ring 30. A plurality of segment rings 31 or the like, here six steel pieces 41 or the like connected in the circumferential direction, are short and substantially circular tubular.

[0025] Pieces 41 or the like are carried into the shield excavator 100, and the pieces 41 or the like are assembled into a ring shape using the erector 50 arranged in the shield excavator 100. Since the pieces 41 or the like are heavy objects, the assembling work is performed inside the shield excavator 100 using the erector 50 provided with a piece assembling attachment 51 capable of assembling the pieces 41 or the like.

[0026] Although not shown in detail, each piece 41 or the like is formed with a held portion such as a recess or a through hole so as to be held by a protruding body such as a pin provided on the curved support member 51a of the piece assembling attachment 51. Each piece 41 or the like is held by the piece assembling attachment 51 by being placed on the support member 51a in a state where its held portion is held by the protruding body.

[0027] The excavation unit 20 has a partition wall 21 and a cutter head 22 that excavates the face in front (face side) of the front end of the skin plate 10. The cutter head 22 is supported by the partition wall 21.

[0028] On the back surface of the partition wall 21, a drive unit 23 for rotationally driving the cutter head 22 is provided. The drive unit 23 is composed of a drive motor, a speed reducer, gears, etc., and the cutter head 22 is rotationally driven at high torque via the drive shaft 24 by the driving force of the drive unit 23.

[0029] The space between the partition wall 21 and the cutter head 22 forms a compartment 25. The compartment 25 is for filling the excavated soil and mud together to counteract the earth pressure from the face. A soil discharging device 26 communicating with the compartment 25 is provided at the rear side of the partition wall 21. The soil discharging device 26 composed of a mud supply pipe 26a and a mud discharge pipe 26b reaches the rear starting shaft.

[0030] At the rear part of the rear skin plate 12, tail seals 61 - 63 for sealing the gap between the outer peripheral surface of the existing segment ring 30 are attached. Note that the tail seals 61 - 63 include brush - shaped tail brushes.

[0031] Each of the tail seals 61 - 63 is annular as a whole and is provided so that its inner circumference contacts the outer peripheral surface of the segment ring 30. When the face side is the front and the shaft side is the rear, the tail seals 61 - 63 are provided in a plurality of stages, here three stages, spaced apart in the front - rear direction. Although not shown in detail, each of the tail seals 61 - 63 is fixed, for example, to a tail plate 12a divided in the circumferential direction for each stage by bolts or the like, and each tail plate 12a is fixed to the rear skin plate 12 by welding, bolts or the like. Thus, each of the tail seals 61 - 63 is replaceable with respect to the tail plate.

[0032] And when replacing the tail seals 61, 62 during tunnel construction, as shown in Fig. 2, pieces 41, etc. constituting the segment ring 31, etc. are arranged so as to be in a predetermined position with respect to the tail seals 61, 62 to be replaced. In other words, in a tunnel under construction where the predetermined pieces 41, etc. are arranged in a predetermined position, the tail seals 61, 62 at the predetermined position can be replaced. Note that Figs. 2 and 3 are schematic development views seen from the central axis side of the shield tunneling machine 100.

[0033] Here, the case of replacing the tail seal 61 of the stage located closest to the face will be described. When constructing a curve or the like, the clearance between the inner peripheral surface of the rear skin plate 12 and the segment ring 31 becomes narrow, so this tail seal 61 is likely to rub against the segment ring 31 and wear, and has the highest replacement frequency. The tail seal 62 may be replaced simultaneously with the tail seal 61. When replacing the tail seal 63, the shaft side needs to be separately sealed.

[0034] Each piece 41 constituting the segment ring 31 located inside (on the central axis side of the shield tunneling machine 100) of the tail seal 61 to be replaced is a steel piece, and one injection port 41a for injecting a water stop agent is formed. However, it is not necessarily required that these pieces 41 be formed with the injection port 41a.

[0035] Each piece 43, 44 constituting the segment rings 33, 34 located on the shaft side by a predetermined number of stages more than the segment ring 31 located inside the tail seal 61 to be replaced is also a steel piece, and a plurality of injection ports 43a, 43b, 44a are formed spaced apart in the circumferential direction. Here, each piece 43 constituting the segment ring 33 located two stages on the shaft side from the segment ring 31 is provided with a plurality of injection ports 43a for injecting consolidation lubricant and injection ports 43b for injecting a water stop agent, which are spaced apart in the circumferential direction.

[0036] This segment ring 33 is located on the shaft side of the tail seal 63 located closest to the shaft side. Note that each piece 44 constituting the segment ring 34, which is one stage on the shaft side from this segment ring 33, that is, here, the segment ring 34 located three stages on the shaft side from the segment ring located inside the tail seal 61 to be replaced, is also provided with a plurality of injection ports 44a for injecting a water stop agent, which are spaced apart in the circumferential direction.

[0037] Each injection port 41a, 43a, 43b, 44a is provided with a check valve (not shown in detail) and is normally sealed with a plug. When injecting the consolidation lubricant or the water stop agent, the plug is removed, and after injection, the injection ports 41a, 43a, 43b, 44a are sealed with the plug.

[0038] Although not shown, all the pieces are provided with at least one injection port for injecting the backfill agent into the gap between the natural ground and the segment ring 30. On the other hand, in the above-described pieces 41 to 44, not only the backfill agent is injected, but it is also necessary to stop the water in the gap between the segment rings 32 to 34 and the natural ground on the shaft side from the tail seal 63. Since this water stop needs to be performed reliably over the entire circumference, a plurality of injection ports 43a, 43b, 44a are provided at intervals in the circumferential direction. Note that since the injection port 41a is provided for injecting the water stop agent in an emergency, only one injection port 41a is provided for each piece 41.

[0039] The number of injection ports 43a provided in each piece 43 constituting the segment ring 33 located two shaft sides from the segment ring 31 located inside the tail seal 61 to be replaced is preferably larger than or the same as the number of injection ports 41a, 44a provided in the other pieces 41, 44. Thereby, it becomes possible to surely stop the water between the segment ring 33, which requires the most water stop and where the tail seals 61 to 63 do not exist on the shaft side from this, and the natural ground.

[0040] Hereinafter, a method for replacing the tail seal of the shield tunneling machine according to the embodiment of the present invention will be described using the above-described shield tunneling machine 100.

[0041] First, as shown in FIG. 2, the positional relationship between the segment rings 31 to 34 with respect to the tail seal 61 to be replaced is set to the above-described predetermined one. In this way, when it is time to replace the tail seal 61, a tunnel is constructed in advance using the predetermined segment rings 31 to 34.

[0042] Then, from each injection port 43a of the piece 43 that constitutes the segment ring 33 located on the shaft side of the tail seal 63, which is the closest to the shaft side, a consolidation lubricant is injected, and then, a water stop agent is injected from the injection port 43b. Thereby, the flow of groundwater from the shaft side of the tail seal 63 can be stopped. Since the backfill agent cannot be injected after the water stop agent is injected, the collapse of the ground is once prevented with the consolidation lubricant, which is a low-strength filler, and then the water stop agent is injected and replaced with the consolidation lubricant. Finally, the backfill agent is injected.

[0043] Next, as shown in FIG. 3, a part of the piece 41 that constitutes the segment ring 31 located inside the tail seal 61 to be replaced is pulled out toward the face side. Here, the case where the piece 41-1 located at the top of the segment ring 31 and the piece 41-2 adjacent to it are pulled out first will be described.

[0044] It is preferable to apply a lubricant in advance to both circumferential side surfaces of these pieces 41-1 and 41-2 that come into contact with the adjacent pieces. Also, it is preferable to embed a sealing material in both of these side surfaces. By these means, it becomes possible to reduce the damage that occurs during pulling out between the pieces 41-1 and 41-2.

[0045] At this time, the operator removes the piece assembly attachment 51 and instead attaches the piece guide attachment 52 to the erector 50 as shown in FIG. 4. Then, the operator operates this erector 50 to pull out the pieces 41-1 and 41-2 to secure the space S. This space S is a space that contains the space where the pieces 41-1 and 41-2 originally existed. The piece guide attachment 52 includes a trough-shaped guide member 52a that guides these pieces 41-1 and 41-2 on the guide surface. Since these pieces 41-1 and 41-2 are guided so as to be pressed against the upper surface of this guide member 52a, it is possible to prevent the remaining pieces 42-1, 42-2, 42-6, etc. from falling off. When guiding the pieces 41-1 and 41-2 located at the upper part, it is supported by the guide member 52a, and when guiding the pieces 41-3 to 41-6 located in the middle part and the lower part, it is preferably configured to be slidable along the guide member 52a.

[0046] While suppressing the remaining pieces 41-3 to 41-6 from falling off with the propulsion jacks 15-3 to 15-6, first pull out the piece 41-1 located at the top and the piece 41-2 on one adjacent side thereof. The piece 41-1 located at the top has both side surfaces inclined so as to widen in a tapered shape toward the face side. And one side surface of the piece 41-2 adjacent to these is inclined corresponding to the side surface in contact with the piece 41-1.

[0047] For the pulling out, first, fix the piece 41-1 at the top and the spreader provided at the end of the rear end of the rod 15a-1 of the propulsion jack 15-1 corresponding thereto. Also, fix the piece 41-2 adjacent to the piece 41-1 at the top and the spreader provided at the end of the rod 15a-2 of the propulsion jack 15-2 corresponding thereto. The fixing of the piece 41-1, etc. and the spreader provided at the end of the rod 15a-1, etc. may be fixed by known detachable fixing means such as a clamp or a vise.

[0048] Thereafter, the rod 15a-1 of the propulsion jack 15-1 is contracted. As a result, the top piece 41-1 is pulled out. And simultaneously with or after this, the rod 15a-2 of the propulsion jack 15-2 is contracted. As a result, the piece 41-2 is pulled out.

[0049] The contraction strokes of the rods 15a-1 and 15a-2 in these extractions shall be a distance longer than the lengths of the spacers 81 and 82 described later. However, the contraction stroke when pulling out the top piece 41-1 shall be a distance slightly longer than the contraction stroke when pulling out the piece 41-2 so that a gap is created between the piece 41-2 when it is pulled out.

[0050] In addition, after replacing the tail seal 61, when the seal portion of the tail seal 61 passes through the segment ring 31 and water leaks out from the joints between the pieces 41 that make up the segment ring 31 due to damage to the tail seal 61, etc., water leakage can be emergently prevented by injecting a water stop agent from each injection port 41a of the piece 41.

[0051] Next, the operator removes the piece guide attachment 52 and instead attaches the water stop plate assembly attachment 53 to the erector 50 as shown in FIG. 5. Then, the operator operates this erector 50 to install the water stop plate 70 as described below.

[0052] The water stop plate assembly attachment 53 is provided with a gripping member 53a capable of gripping the water stop plate 70. By gripping the water stop plate 70 with this gripping member 53a, the heavy water stop plate 70 can be easily assembled by the erector 50. Here, the water stop plate assembly attachment 53 has a configuration in which the gripping member 53a is added to the piece guide attachment 52, but it is not limited to such a configuration and may be something that removably holds the water stop plate 70.

[0053] Then, as shown in FIGS. 3 and 5, a water stop plate 70 is installed on the exposed surfaces of the pieces 41-3, 41-6, 42-1, 42-2, and 42-6 exposed in the space S as required. The water stop plate 70 includes a first water stop plate 71 that covers one exposed side surface of the pieces 41-3 and 41-6 and extends in the front-rear direction (the central axis direction of the shield tunneling machine 100), and a second water stop plate 72 that covers the exposed front surfaces of the pieces 42-1, 42-2, and 42-6 and has a shape in which an annular shape is divided to cover the space between the outer peripheral surface of the pieces 41-3 and 41-6 and the inner peripheral surface of the rear skin plate 12. These two types of water stop plates 71 and 72 may be installed either singly or both, depending on the water stop situation using a water stop agent or the like. Here, the case of installing both water stop plates 71 and 72 will be described.

[0054] Through holes through which bolts for connecting adjacent pieces are inserted are formed in both side walls of each of the pieces 41-3 and 41-6, although not shown. The first water stop plate 71 is composed of a rectangular steel flat plate that abuts against the exposed side walls of the remaining pieces 41-3 and 41-6 over substantially the entire surface. Then, it is fixed to the side walls 41-3 and 41-6 of the remaining pieces by bolts inserted through the through holes formed in this flat plate and the through holes formed in the side walls. Further, notches are formed in the first water stop plate 71 so as to replace the tail seals 61 and 62.

[0055] The second water stop plate 72 has a divided annular flat plate shape obtained by dividing the front surfaces of the pieces 42-1 to 42-6 into six parts so as to cover the front surfaces of the exposed pieces 42-1, 42-2, and 42-6 over substantially the entire surface.

[0056] In addition, each through hole formed in these water stop plates 71 and 72 is an oblong hole having the radial direction of the shield as the major axis in order to ensure a large adjustment width for the position of the bolt.

[0057] Next, the worker sets up scaffolding (not shown) inside the shield tunneling machine 100 as needed, and uses this scaffolding to replace the tail seal 61. Specifically, the tail seal 61 to be replaced is cleaned and then removed. Then, after shaping the tail plate and skin plate as needed, a new tail seal 61 is installed.

[0058] Thereafter, the worker removes scaffolding or the like as necessary, removes the waterstop plate assembly attachment 53, and instead attaches the spacer placement attachment 54 to the erector 50 as shown in FIG.

[0059] Then, by operating this erector 50, spacers 81 and 82 are placed in the gaps between the pulled-out pieces 41-1 and 41-2 and the remaining pieces 42-1, 42-2, and 43-6 in the front-to-rear direction, as shown in Figures 6 and 7, to prevent buckling. The spacers 81 and 82 are made of steel and have a predetermined length. Here, the length of the spacer 81 placed in the space S after the top piece 41-1 has been pulled out is slightly longer than or the same as the length of the spacer 82 placed in the space S after the adjacent piece 41-2 has been pulled out.

[0060] The spacer arrangement attachment 54 is equipped with a holding member 54a that detachably holds the spacers 81, 82. The upper end wall of the holding member 54a can be fixed with bolts to seats that are fixed by welding to the inner sides of the spacers 81, 82. By holding the spacers 81, 82 with this holding member 54a, it becomes possible to position the heavy spacers 81, 82 within the space S.

[0061] Thereafter, by slightly extending the rods 15a-1 and 15a-2 of the propulsion jacks 15-1 and 15-2, the spacer 81 is sandwiched between the pieces 41-1 and 42-1 positioned in the fore-and-aft direction thereof, and the spacer 82 is sandwiched between the pieces 41-2 and 42-2 positioned in the fore-and-aft direction thereof, and the pieces 41-1 and 41-2 are maintained in the pulled-out state by the spacers 81 and 82.

[0062] Next, as shown in FIG. 8, the pieces 41-3 and 41-6 that are arranged adjacent to the pieces 41-1 and 41-2 maintained in the pulled-out state are pulled out. The piece 41-6 adjacent to the other side of the top piece 41-1 has one side inclined corresponding to the side surface in contact with the top piece 41-1. On the other hand, both side surfaces of the piece 41-3 are not inclined. The pulling out of these two pieces 41-3 and 41-6 is performed in the same manner as the pulling out of the pieces 41-1 and 41-2 already described. Note that the pieces may be pulled out one by one or two at a time.

[0063] Note that the contraction stroke of the rod 15a-6 when pulling out the piece 41-6 adjacent to the top piece 41-1 may be set to the same length as or less than the length of the rod 15a-1 corresponding to the piece 41-1 in the pulled-out state. Also, the contraction stroke of the rod 15a-3 when pulling out the other piece 41-3 may be the same as, slightly larger than, or slightly smaller than this rod 15a-6.

[0064] Then, using the space S generated by the pulling out of these two pieces 41-3 and 41-6, in the same manner as above, the tail seals 61-3 and 61-6 are replaced, and further, the spacers 83 and 86 are installed. The lengths of the spacers 83 and 86 may be set to lengths corresponding to the contraction strokes of the rods 15a-3 and 15a-6. Note that the first water stop plate 71 is once removed and installed on the exposed side walls of the remaining pieces 41-4 and 41-5.

[0065] Next, as shown in FIG. 9, the remaining pieces 41-4 and 41-5 that constitute the segment ring 31 located inside the tail seal 61 to be replaced are pulled out. Both side surfaces of these are not inclined. The pulling out of these two pieces 41-4 and 41-5 is performed in the same manner as the pulling out already described. Note that the pieces may be pulled out one by one or two at a time.

[0066] When pulling out the remaining pieces 41-4 and 41-5, the contraction stroke of the rods 15a-4 and 15a-5 may be the same as the contraction stroke of the rod 15a-3 when pulling out the piece 41-3 whose both side surfaces that have already been pulled out are not inclined.

[0067] Then, using the space S generated by pulling out these two pieces 41-4 and 41-5, the tail seals 61-4 and 61-5 are exchanged in the same manner as above, and furthermore, spacers 84 and 85 are installed. Note that the first water stop plate 71 is removed. Also, both ends of adjacent second water stop plates 72 are connected to each other.

[0068] Then, after applying silicon seal or tail grease or the like to the tail seal 61, the segment ring 31 is restored. This is done by slightly contracting the rods 15a of the propulsion jacks 15 to remove the spacers 81 to 86, and then extending the rods 15a of the propulsion jacks 15 to return each piece 41-1 to 41-6 to its original position. This process may be performed in the reverse order of the pulling-out order, and finally the top piece 41-1 is returned to its original position. As described above, since the both side surfaces of the piece 41-1 are inclined so as to expand in a tapered shape toward the front together, by pushing these in, the segment ring 31 can be surely returned to its original shape.

[0069] When returning the pieces 41-1 to 41-6, it is preferable to apply a lubricant to both side surfaces thereof. Also, it is preferable to embed a new sealing material in both side surfaces. By these measures, it becomes possible to reduce the damage caused to the pieces 41-1 to 41-6 when returning them.

[0070] Thereby, the replacement work of the tail seal 61 is completed, but a backfill agent is injected from an injection port (not shown) and replaced with a water stop agent. After that, the process of constructing the segment ring may be performed in the same manner as usual.

[0071] The present invention is not limited to the method for replacing the tail seal of the shield tunneling machine described above, and can be appropriately changed. For example, it is not limited to using the shield tunneling machine 100 described above, and various known shield tunneling machines can be used.

[0072] In addition, in the segment ring 31 composed of six pieces 41, the case where the pieces 41 are pulled out two by two in three times has been described. However, it is not limited to this. For example, the pieces 41 may be pulled out one by one in six times, or three by three in two times.

Explanation of Signs

[0073] 10... Skin plate (body, tunneling machine body), 11... Front skin plate, 12... Rear skin plate, 12a... Tail plate, 15(15-1~15-6)... Propulsion jack, 15a(15a-1~15a-6)... Rod, 20... Excavation unit (tunneling machine body), 21... Partition wall, 22... Cutter head, 23... Driving unit, 30... Existing segment ring, 31~36... Segment ring, 41(41-1~41-6), 42~45... Piece, 41a, 43a, 43b, 44a... Injection port, 50... Erector (assembly device), 51... Piece assembly attachment, 51a... Support member, 52... Piece guide attachment, 52a... Guide member, 53... Water stop plate assembly attachment, 53a... Gripping member, 54... Spacer arrangement attachment, 54a... Holding member, 61~63... Tail seal, 70... Water stop plate, 71... First water stop plate, 72... Second water stop plate, 81~86... Spacer, 100... Shield tunneling machine, S... Space.

Claims

1. During the construction of a tunnel by advancing a tunneling machine body toward the face side by extending the rods of a plurality of propulsion jacks using an existing segment ring composed of pieces divided in the circumferential direction as a reaction force receiver, and sequentially installing new segment rings on the face side of the existing segment ring, a method for replacing a tail seal that is fixedly provided in a replaceable manner at the rear part of the body of the tunneling machine body and seals between the inner circumferential surface of the body and the outer circumferential surface of the existing segment ring, comprising: Fixing at least one piece among the pieces constituting the existing segment ring located inside the tail seal to be replaced to a spreader of a rod of at least one of the plurality of propulsion jacks, and pulling out the piece toward the face side by contracting the rod; Replacing the tail seal to be replaced, which is fixed to the rear part of the body of the tunneling machine body exposed in the space through the space generated by pulling out the piece. A method for replacing a tail seal of a shield tunneling machine, characterized by the above.

2. After pulling out the at least one piece located inside the tail seal to be replaced, fixing the piece and a piece adjacent in the circumferential direction to a spreader of a rod of at least one other propulsion jack among the plurality of propulsion jacks, and pulling out the piece toward the face side by contracting the rod. The method for replacing a tail seal of a shield tunneling machine according to claim 1, characterized by the above.

3. Fixing at least one piece among the at least one piece located inside the tail seal to be replaced and a piece adjacent in the circumferential direction to the piece, fixing at least any one of these pieces to a spreader of a rod of at least one of the plurality of propulsion jacks, and pulling out these pieces simultaneously toward the face side by contracting the rod. The method for replacing a tail seal of a shield tunneling machine according to claim 1, characterized by the above.

4. Fix the at least one piece located inside the tail seal to be replaced to the piece located on the face side of the piece, and fix the piece located on the face side to the spreader of the rod of at least one of the plurality of propulsion jacks, and simultaneously pull out these pieces toward the face side. The method for replacing the tail seal of a shield tunneling machine according to claim 1, characterized by this.

5. After pulling out the at least one piece located inside the tail seal to be replaced, interpose a spacer between the piece and the piece located on the opposite side of the piece against the face. Thereafter, fix at least one of the piece and at least one of the pieces adjacent in the circumferential direction to the spreader of the rod of at least one of the plurality of propulsion jacks, and pull out the piece toward the face side by contracting the rod. The method for replacing the tail seal of a shield tunneling machine according to any one of claims 1 to 4, characterized by this.

Images