JP2017218776A - Shield machine having back injector, and cut-off method of tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shield machine having a back injector of a simultaneous injection method capable of reliably forming a water stop zone by outer periphery of a shield tunnel, and a tunnel cut-off method.SOLUTION: A shield machine 10 includes: a backfill injection pipe 21; and a back injector 20 which has a housing 23 covering the backfill injection pipe 21. The back injector 20 is disposed being fixed to the inner peripheral surface of a skin plate 1. The housing 23 is provided with a tail seal 31 on the inner peripheral surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a backfill injection device in a shield machine and a tunnel water stopping method using the same.

In the shield method, the backfill material is injected and filled into the tail void in the space between the excavated ground and the segment.
Generally, there are an immediate injection method and a simultaneous injection method as a method for injecting the backing material. In the immediate injection method, the backing material is injected from an injection port penetrating from the inner peripheral side to the outer peripheral side of the segment. The simultaneous injection method injects the backing material from the backing injection device provided in the shield machine. The simultaneous injection method can inject the backing material from the shield machine while digging, so the time when nothing is filled in the tail void can be shortened, and it is more effective in suppressing the influence of land subsidence etc. .

  As a conventional technique of the back injection apparatus of the simultaneous injection method, as illustrated in Patent Document 1, two protrusions are formed along the digging direction on both sides of the upper outer periphery of the rear shell of the shield. A back-filling injection tube is disposed in the.

Such a back-injection apparatus of the simultaneous injection system is shown in FIGS.
FIG. 9A is a view of the shield machine 110 viewed from the rear. The back-filling injection device 120 is provided at two upper portions of the outer peripheral surface of the skin plate 101 of the shield machine 110. Then, the backing material is injected and filled into the tail void 103 between the segment 102 and the excavated ground from the backing injection device 120.
FIG. 9B is an enlarged view of the back-filling injection device 120. The back injection pipe 121 and the pressure gauge 122 are covered with a housing 123. The housing 123 is provided so as to protrude from the outer peripheral surface of the skin plate 101. As described above, since the back-injection device 120 is provided on the outer peripheral surface of the skin plate 101, a tail void enlarged portion 103 ′ in which the tail void 103 becomes larger by the amount of the housing 123 is generated.
FIG. 10 is a longitudinal sectional view of FIG. In this example, the tail seal 131 is provided in three stages on the inner peripheral surface of the skin plate 101. The tail seal 131 prevents earth and sand, groundwater, a backing material and the like from entering between the segment 102 and the skin plate 101.

  In such a simultaneous injection type back-injection device, in particular, during injection, the back-up material may fall below the tail void 103, and the back-fill material may not be reliably filled up to the tail void enlarged portion 103 ′. Can occur. Further, since the tail void width of the tail void 103 below the tail void enlarged portion 103 ′ becomes narrow, the resistance when the backing material flows increases, and there is a possibility that sufficient filling to the lower portion of the tail void 103 may not be obtained. Can occur.

By the way, in general, a tunnel is required to have a water-stopping property, and the same applies to a shield tunnel. The water blocking property of the shield tunnel is mainly borne by the segment that is the tunnel structure. However, in underground connection where a new shield tunnel is connected to an existing shield tunnel or parallel connection where a parallel shield tunnel is connected, etc., the segment itself will be cut or lost, so it will be stopped by other than the segment. It is necessary to secure water.
In such a case, a water stop zone is provided outside the segment by a freezing method or a chemical injection method.
These methods become facilities and processes different from the shield excavation process, and require a construction period and cost.

JP 2003-278490 A

  Focusing on the water-stopping effect of the backing material, a sufficient thickness of the backing material and its reliable filling are required to form a water-stop zone with the backing material of the back-filling device of the simultaneous injection method. It becomes. However, with the normal arrangement of the skin plate and the segment, a sufficient thickness of the backing material cannot be ensured. In addition, the tail void enlarged portion formed by the housing protruding on the outer peripheral surface of the skin plate may cause a problem in the reliable filling and filling of the backing material.

  Therefore, in view of the above-described problems of the prior art, an object of the present invention is to provide a shield machine and a tunnel water stop having a simultaneous injection type backfill injection device that can reliably construct a water stop zone on the outer periphery of the shield tunnel. Is to provide a method.

  The invention according to claim 1 of the present application is a shield machine having a backfill injection device having a backfill injection tube and a housing that covers the backfill injection tube, wherein the backfill injection device is a skin plate. The shield machine is fixed to an inner peripheral surface, and a tail seal is provided on the inner peripheral surface of the housing.

  The invention according to claim 2 of the present application is characterized in that the backfill injection device is fixedly provided on a part of the inner peripheral surface of the skin plate in the circumferential direction. Machine.

  In the invention according to claim 3 of the present invention, a spacer is provided on the inner peripheral surface of the skin plate and the back-filling device is not fixed, and a tail seal is provided on the inner peripheral surface of the spacer. The shield machine according to claim 2, wherein the shield machine is provided.

  The invention according to claim 4 is characterized in that the shield machine has a plurality of rows of tail seals, and a plurality of the spacers are provided corresponding to the plurality of rows of tail seals, respectively. The shield machine according to claim 3.

  The invention according to claim 5 of the present application is the shield machine according to claim 4, wherein a closing member for closing the space between the spacers is provided.

  According to a sixth aspect of the present invention, the shield machine has a plurality of rows of tail seals, and the rear end of the housing is provided with a tail seal of the last row on the inner peripheral surface and is backed up. The shield machine according to any one of claims 1 to 5, wherein a spacer having an opening serving as a material passage is provided so as to be connected to the entire inner peripheral surface of the skin plate. It is.

  The invention according to claim 7 of the present application is a shield machine having a backfill injection device having a backfill injection tube and a housing that covers the backfill injection tube, wherein the backfill injection device is a skin plate. It is fixedly provided on a part of the inner peripheral surface in the circumferential direction. A spacer is provided in a ring shape on the entire inner peripheral surface of the skin plate, and a tail is provided on the entire inner peripheral surface of the spacer. In the shield machine, a seal is provided, and the spacer includes an opening serving as a passage for a backing material.

  The invention according to claim 8 of the present application is a tunnel water stopping method in which a backing material is injected into a tail void using the shield machine according to any one of claims 1 to 7.

  With the configuration according to claims 1 to 8, it is possible to realize a tunnel excavator having a simultaneous injection type back-injection device capable of reliably constructing a water stop zone on the outer periphery of the shield tunnel and a tunnel water stop method using the same.

It is explanatory drawing of the shield machine in embodiment of this invention. It is a longitudinal cross-sectional view of the shield machine in embodiment of this invention. It is explanatory drawing of the back injection apparatus in embodiment of this invention. It is detail drawing of the backfill injection apparatus and tail seal in embodiment of this invention. It is detail drawing of the tail seal in embodiment of this invention. It is detail drawing of the back injection apparatus in embodiment of this invention. It is explanatory drawing of the construction example which applies the water stop zone by this invention. It is explanatory drawing of the construction example which applies the water stop zone by this invention. It is explanatory drawing of the backfill injection apparatus of a prior art. 1 is a longitudinal view of a prior art backfilling device.

  Hereinafter, embodiments of the backfill injection device of the present invention will be described with reference to the drawings. In addition, although it demonstrates using a numerical value in description, the said numerical value is an illustration and it cannot be overemphasized that this invention is not limited by the said numerical value.

FIG. 1A is a view of a shield machine 10 according to the present invention as seen from the back. In the shield machine 10, a segment 2 that is a tunnel structure is assembled inside the skin plate 1.
FIG. 2 is a longitudinal sectional view of FIG. 1 (A) of the rear trunk portion of the shield machine according to the present invention. The upper drawing of FIG. 2 is a vertical sectional view of a portion where the back-filling injection device 20 is disposed. The lower diagram of FIG. 2 is a longitudinal sectional view of the lower part of the portion where the backfill injection device 20 is not disposed.

The back void material is injected and filled into the tail void 3 between the excavated ground and the segment 2. The thickness of the tail void 3 that defines the thickness of the backing material is set to a sufficient dimension in consideration of water stoppage. In this embodiment, for the segment having an outer diameter of 5450 mm, the tail void 3 has a uniform thickness of 150 mm so as to ensure water-stopping. Conventionally, the thickness of the tail void into which the backing material is injected and filled is set to about 75 mm for the outer diameter of the same segment (about 150 mm for the tail void enlarged portion where the back injection device is provided). Therefore, in this embodiment, the thickness of the backing material is doubled. The thickness of the segment 2 is 150 mm.
Normally, the natural ground excavated by the cutter of the shield machine is slightly larger than the outer peripheral surface of the skin plate, and the excavation surface of the natural ground and the outer peripheral surface of the skin plate are not the same. However, in this specification, it is described as the same for convenience of explanation.

  As shown in FIG. 1 (A), the back-filling injection device 20 is fixedly provided at two places in the upper circumferential direction of the inner peripheral surface of the skin plate 1 and two places in the lower circumferential direction of the inner peripheral surface. Yes. The lower part is also provided in consideration of more reliable backfilling. In the present embodiment, a total of four portions are provided, two at each of the upper portion and the lower portion, but the number and arrangement thereof may be appropriately set in consideration of the filling property and efficiency of the backing material. Further, the lower part may be omitted.

FIG. 1B shows an enlarged view of the back-filling injection device 20. The backfill injection apparatus 20 has a backfill injection pipe 21, a pressure gauge 22, and a housing 23 that covers them. The housing 23 has a function of protecting the back-injection pipe 21 and the pressure gauge 22 from contact with the segment 2 and the like, and is configured so as not to follow the resistance of the excavation due to the contact with the segment 2 during the excavation. . The housing 23 includes a housing main body portion 23a where the tail seal 31 is provided, a housing inclined portion 23b that connects the skin main body 23a to the skin plate 1, and a housing reinforcing portion 23c that supports the housing main body portion 23a.
The housing 23 is configured so that earth and sand, groundwater, backing material, and the like do not enter therein, and has an end plate (not shown) at the skin plate rear end portion 11 (FIG. 3) of the shield machine. The discharge port of the back-injection pipe 21 and the detection part of the pressure gauge 22 are configured to be exposed to the tail void 3 from the end plate. As a result, the portions other than the exposed portions of the backfill injection pipe 21 and the pressure gauge 22 can be protected from earth and sand, groundwater, the backfill material and the like.

Thus, since the back injection device 20 is provided on the inner peripheral surface of the skin plate 1, the tail void 3 can be made to have a uniform width, and the portion where the back injection device 20 is disposed. However, it does not have an enlarged shape. Therefore, when the backing material is injected, it smoothly flows and is surely filled in the tail void 3 to ensure water stopping.
In addition, since the back injection device 20 is provided on the inner peripheral surface of the skin plate 1, the housing 23 is disposed in front of the tail seal 31 in the last row even when a malfunction occurs in the back injection tube 21 or the like. If it can be removed or an opening / closing lid is provided on the inner peripheral surface of the housing 23, maintenance work can be safely performed inside the skin plate 1.
Further, since the back-filling device 20 is provided on the inner peripheral surface of the skin plate 1 whose inside is to be excavated, compared to the case where the back-filling device is provided so as to protrude from the outer peripheral surface of the skin plate. The digging resistance due to the backfilling device part can be reduced.

FIG. 3 is a detailed view of the backfill injection device 20 as viewed from the inside of the shield machine 10. The housing 23 is not shown. The lining material injection pipe 21 mixes the lining material A liquid from the lining material A liquid injection pipe 24 and the lining material B liquid from the lining material B liquid injection pipe 25 and injects the backing material. Is. A check valve (not shown) is provided at the front end of the back material B liquid injection pipe 25 before the joining portion with the back material A liquid injection pipe 24, and the back material A liquid and cleaning water to be described later are provided. The back material B liquid injection pipe 25 is prevented from entering.
The waterproof performance of the backing material is selected according to the required waterproof performance.

  The backfill injection device 20 also includes a cleaning water pipe 26. The valve 27 is moved to be positioned on the tip side of the joining portion of the back-filling injection pipe 21 with the back-filling material A liquid injection pipe 24 and closes the discharge port of the back-filling injection pipe 21. Then, the cleaning water sent from the cleaning water pipe 26 is returned to the backing material A liquid injection pipe 24 to clean the injection pipe after the back injection. In FIG. 3, the valve 27 shows a position at the time of back-filling injection. The valve 27 is operated by hydraulic pressure from the hydraulic pipe 28. In FIG. 3, the back injection pipe 21 is disposed so as to protrude from the skin plate rear end portion 11 of the shield machine 10. A pressure gauge 22 for managing the backfill injection pressure is provided in parallel with the backfill injection pipe 21. An end plate (not shown) of the housing 23 is erected along the rear end portion 11 of the skin plate 1.

As shown in FIG. 2, the tail seals 31 are provided in three rows in the front-rear direction over the entire circumference. The tail seal 31 prevents earth and sand, groundwater, a backing material and the like from entering between the skin plate 1 and the segment 2.
In the present embodiment, the thickness of the skin plate 1 is 12 mm at the portion where the tail seal 31 is provided, and is thick at 40 mm where the tail seal 31 is not provided. Since the part where the tail seal 31 of the skin plate 1 is provided has a segment assembled in a ring shape, it is possible to receive soil water pressure from the outside also by this segment. Therefore, the skin plate 1 in this portion can be thinned.

  As shown in FIG. 4A, a tail seal 31 is provided on the inner peripheral surface of the housing main body 23 a of the housing 23. Since the tail seal 31 is provided, the inner peripheral surface of the housing body 23 a has a shape that matches the curved surface of the skin plate 1. As long as the function of the tail seal 31 can be exhibited, the inner peripheral surface of the housing body 23a may be horizontal.

  As shown in FIGS. 1, 2, and 4 (B), a spacer 30 is provided on the inner peripheral surface of the skin plate 1 where the housing main body portion 23 a is not located so as to match the curved surface of the skin plate 1. A tail seal 31 is provided on the inner peripheral surface of the spacer 30. In FIG. 1, FIG. 2, and FIG. 4B, the spacer 30 is indicated by hatching. In FIG. 1, the tail seal 31 is not shown.

As shown in FIG. 1B, the spacer 30 is provided so that its inner peripheral surface is flush with the inner peripheral surface of the housing main body 23a and the surface on which the tail seal 31 is provided. The spacer 30 is provided in the housing inclined part 23b so as to become thinner gradually.
The spacer 30 may be any material such as H steel, a plate, a block, etc., as long as it can fix the tail seal 31 and can secure the water stop together with the tail seal 31.

  In FIG. 2 and FIG. 4 (B), the spacer 30 is provided with one row of spacers 30 for each row of tail seals 31, but one row of spacers for a plurality of rows of tail seals, that is, a plurality of tails for one row of spacers. You may comprise so that a seal | sticker may be provided. FIG. 5A shows an embodiment in which one row of spacers 30 is arranged on the tail seals 31 in the middle row and the last row. With such a configuration, the amount of tail grease used between the tail seals 31 in adjacent rows can be suppressed. Further, as shown in FIG. 5B, a closing member 32 such as a plate may be provided to close the space between adjacent spacers.

  As described above, by providing the spacer 30 in the portion where the housing 23 where the tail seal 31 is provided does not exist, a tail seal corresponding to a portion where the gap between the skin plate 1 and the segment 2 is large (portion where there is no housing) is separately provided. There is no need. As described above, when one type of tail seal of a type corresponding to a gap of one dimension is employed, stability in waterstop is higher than when a plurality of types of tail seals are employed.

  The spacer 30 may be omitted depending on various conditions. In this case, the tail seal is provided directly on the inner peripheral surface of the skin plate. Moreover, it is provided also in the internal peripheral surface of a housing main-body part and a housing inclination part. The tail seal provided directly on the inner peripheral surface of the skin plate has a large gap between the segment and the skin plate. The tail seal provided on the inclined portion of the housing adopts a tail seal that can cope with a gap that changes for a while.

  In order to sufficiently fill the tail void 3 with the backing material, a certain amount of injection pressure is required. When this injection pressure increases, the backing material may wrap around from the rear side of the outer periphery of the skin plate 1 to the face side. When the wraparound occurs, not only the backing material is wasted, but there is a possibility that the tail void 3 cannot be sufficiently filled. When the backfill injection device is attached to the outer peripheral surface of the skin plate as in the prior art, the boundary portion along the front and rear direction of the shield machine between the housing of the backfill injection device and the natural ground is It can also be a passage that guides the wrap around the face. However, in the present invention, since the back injection device 20 is provided on the inner peripheral surface of the skin plate 1, a passage serving as a guide is not formed, and wraparound can be suppressed.

Further, in order to prevent the back material from wrapping around the face, a back flow preventing blade 4 for the back material may be provided over the entire periphery of the rear end of the skin plate 1 as shown in FIGS.
The backflow prevention blade 4 is attached to the outer peripheral surface of the skin plate 1. In the present invention, since the back-filling device 20 is provided on the inner peripheral surface of the skin plate 1, the backflow prevention blade 4 can be easily mounted without hindering the mounting on the outer peripheral surface of the skin plate 1. Moreover, even if the backflow prevention blade is attached along the protruding shape on the outer peripheral surface of the skin plate having the back-filling injection device provided so as to protrude as in the prior art, the backflow occurs because of the protruding shape. The prevention blade has a complicated shape. However, in the present invention, there is no protruding portion due to the back-injection device on the outer peripheral surface of the skin plate, the backflow prevention blade 4 does not have a complicated structure, and the back material to the face improves the effect of preventing the back-around. be able to.

As shown in FIG. 6, a spacer 30 having openings for penetrating the backing material A liquid injection pipe 24, the backing material B liquid injection pipe 25, etc. is provided on the entire inner peripheral surface of the skin plate 1. You may make it provide the housing 23 in the part in which 30 is not provided. In this case, since the spacer 30 can be provided continuously in a ring shape, the water blocking property is more than that of the embodiment shown in FIG. 4 in which the boundary between the housing and the spacer is formed along the longitudinal direction of the shield machine. Excellent.
Adequate water stoppage measures shall be taken between the injection pipe and its opening. Further, the opening itself of the spacer 30 may be used as a flow path for the backing material.

  In the embodiment shown in FIG. 6, three rows of spacers 30 that are continuously provided in a ring shape are provided, but tail seal portions in appropriate rows may be provided in a ring shape. For example, the spacer 30 of only the tail seal portion of the last row is provided in a ring shape on the entire periphery, and the spacer 30 excluding the housing main body 23a as shown in FIG. 4 is provided for the two rows ahead of it. You may do it. In this case, the tail seal spacer 30 in the last row is provided so as to be connected to the housing 23 provided in front thereof, and the back-filling injection pipe 21 and the pressure gauge 22 as in the above-described end plate. It is provided with a function capable of protecting the parts other than the exposed part from earth and sand, groundwater, backing material and the like.

  2 and 4B show the segment drop prevention device 5. The segment drop prevention device 5 is for securing a necessary clearance with respect to the lower side of the skin plate 1 when the segment 2 is assembled. In the figure, the segment drop prevention device 5 is provided so as to be connected to the spacer 30 of the tail seal 31 in the front row. The segment drop prevention device 5 is formed of an appropriate material such as a reinforcing bar or steel material, and the assembled segment 2 does not become an obstacle such as contact with the spacer 30 or the tail seal 31 when the shield machine 10 moves forward. The height, material, and shape. The segment drop prevention device 5 may be formed by extending the spacer 30 in the forward direction of the shield machine.

A backfilling method and a tunnel water stopping method using a shield machine equipped with the backfilling device will be described below.
The shield machine 10 is advanced by extending the shield jack while rotating the cutter head of the shield machine 10 to excavate the ground. Next, the segment 2 is assembled in a ring shape at the rear trunk portion inside the skin plate 1 while appropriately reducing the shield jack of the shield machine 10. Repeating these steps is the basic shield construction process.

The backfill injection by the backfill injection apparatus of the present embodiment is performed by a so-called simultaneous injection method that is performed as the shield machine 10 advances. While the shield machine 10 is moving forward, it is injected immediately after the tail void 3 is generated by the back injection pipe 21 opened to the tail void 3. For this reason, the time when nothing is filled in the tail void 3 can be shortened, which is effective in suppressing the influence of land subsidence and the like, and can improve the water-stopping property of the tunnel quickly.
The backing material injected and filled by the backing injection device of the present invention has a sufficient thickness and filling, and exhibits a high effect as a water stop zone. As a result, the water stoppage can be ensured even under conditions where the segment is cut or chipped.

  In the tunnel water stop method using this backfill injection device, the outer diameter of the shield machine increases and the amount of excavated earth and sand increases, but under conditions where tunnel water stoppage is more important, such as the tunnel excavation length is relatively short, It is particularly effective.

  The present invention is not limited to the above embodiment. For example, the following are included.

In the present embodiment, the simultaneous back-injection method in which back-injection is performed simultaneously with excavation of the shield machine is not limited to this, but back-injection is performed when the shield machine is stopped. You can do it.
In this embodiment, it is assumed that a water stop zone is formed in the case where the segment is cut or chipped. However, not only in such a case, but the segment is not cut or chipped. Even in the case of a non-water-stop zone, it can be applied as an auxiliary water-stop zone. It can also be applied to a water stop zone that is used in combination with ground improvement methods such as the freezing method and chemical injection method.

An example in which the water stop zone formed according to the present invention is applied when the segment is cut or chipped will be described below.
FIGS. 7 (A) and 7 (B) are enlarged views of a part of a cross section when a bulkhead structure C such as RC concrete is constructed in the underground G and a relatively large space is constructed in the interior N. is there. The partition wall structure C is constructed in a space connecting parallel shield tunnels. FIG. 7 (A) is constructed using a conventional freezing method, and FIG. 7 (B) is an application of the water stop zone according to the present invention. The upward direction of the drawing is the ground direction, and the downward direction is the underground direction.

First, the construction procedure will be described using the conventional freezing method shown in FIG.
The preceding shield tunnel S1 is constructed with a predetermined interval. The segment constituting the preceding shield tunnel S1 is made of a material that can be cut by the subsequent shield machine. A freezing pipe P used in the freezing method is attached to the segment constituting the preceding shield tunnel S1.
The fluidized soil R is filled in the preceding shield tunnel S1. The fluidized soil R is filled in order for the subsequent shield machine to stably cut when the preceding shield tunnel S1 cuts the preceding shield tunnel S1. The fluidized soil R is also adjusted so that the subsequent shield machine can be cut.

A trailing shield tunnel S2 is constructed between the preceding shield tunnels S1. The trailing shield tunneling machine excavates the segment of the leading shield tunnel S1 and the fluidized soil R while assembling the segment of the trailing shield tunnel S2. A freezing pipe P used in the freezing method is also attached to the segment constituting the trailing shield tunnel S2.
Using the freezing pipe P attached to the preceding shield tunnel S1 and the succeeding shield tunnel S2, a freezing method is performed to form frozen soil T around it.

A part SX of the segment of the trailing shield tunnel S2 is removed, the fluidized soil R filled in the leading shield tunnel S1 is removed, and the leading shield tunnel S1 and the trailing shield tunnel S2 are connected. At the time of this connection, groundwater W tries to enter from the boundary between the preceding shield tunnel S1 and the subsequent shield tunnel S2, but does not enter because the frozen ground T is formed.
A partition wall structure C such as RC concrete is constructed inside the connected preceding shield tunnel S1 and subsequent shield tunnel S2.

A process of applying the water stop zone according to the present invention shown in FIG. 7B will be described.
In this construction, water blocking zones 51 and 52 of sufficient thickness are formed by backfill injection according to the present invention in the construction of the leading shield tunnel S1 and the trailing shield tunnel S2, and the leading shield tunnel S1 and the trailing shield are formed. The entry of groundwater W from the boundary with the tunnel S2 is prevented.

The basic construction order is the same as that shown in FIG.
The water stop zone 51 is formed when the preceding shield tunnel S1 is constructed, and the water stop zone 52 is also formed as shown in FIG. 7B when the subsequent shield tunnel S2 is constructed thereafter. Then, the water stop zone 52 of the subsequent shield tunnel S2 is bonded to the segment of the preceding shield tunnel S1 and the water stop zone 51 so that the groundwater W can enter from the boundary between the preceding shield tunnel S1 and the subsequent shield tunnel S2. Can be prevented. Therefore, it is possible to safely remove a part SX of the segment of the trailing shield tunnel S2 and remove the fluidized soil R filled in the preceding shield tunnel S1.

An example in which the water stop zone formed according to the present invention is applied when the segment is not cut will be described below.
FIG. 8 is an enlarged view of a part of a cross section when a partition wall structure C such as RC concrete is constructed in the underground G and a relatively large space is constructed in the interior N. The partition wall structure C is constructed in a space connecting parallel shield tunnels. In this example, the freezing method is used together. The upward direction of the drawing is the ground direction, and the downward direction is the underground direction.

  The preceding shield tunnel S1 is constructed with a predetermined interval. The water stop zone 51 is formed simultaneously with the construction of the preceding shield tunnel S1. A freezing pipe P used in the freezing method is attached to the segment constituting the preceding shield tunnel S1, but the illustration is omitted.

  A trailing shield tunnel S2 is constructed between the preceding shield tunnels S1 arranged side by side, at positions on the upper side and the lower side. The subsequent shield tunnel S2 is constructed so that the water stop zone 51 of the preceding shield tunnel S1 and the water stop zone 52 of the subsequent shield tunnel S2 overlap each other. More specifically, after the water blocking zone 51 of the preceding shield tunnel S1 is cut by the subsequent shield machine, the water blocking zone 52 of the subsequent shield tunnel S2 is formed in that portion. The water stop zone 52 of the subsequent shield tunnel S2 is bonded to the water stop zone 51 of the preceding shield tunnel S1 to prevent intrusion of groundwater W from the boundary between the preceding shield tunnel S1 and the subsequent shield tunnel S2. Can do. A freezing pipe P used in the freezing method is attached to the segment constituting the trailing shield tunnel S2, but the illustration is omitted.

Using the freezing pipe P attached to the preceding shield tunnel S1 and the subsequent shield tunnel S2, a freezing method is applied, and frozen soil T is formed around it.
A part SX of the preceding shield tunnel S1 is removed, the preceding shield tunnel S1 is connected to form an internal space, and a partition wall structure C such as RC concrete is constructed. When a part SX of the preceding shield tunnel S1 is removed, the water stop zone 52 of the subsequent shield tunnel S2 is bonded to the water stop zone 51 of the preceding shield tunnel S1, and the frozen soil T also exists. Intrusion of groundwater W from the boundary between the preceding shield tunnel S1 and the subsequent shield tunnel S2 can be prevented.

  As for the shape of the housing 23 of the back-filling injection device 20, the housing body 23 a may be a flat surface instead of a curved surface. The housing inclined portion 23b need not be strictly inclined, and may be substantially perpendicular to the housing main body portion 23a. Further, the housing reinforcing portion 23c may also have a column shape or a rib shape, and may be omitted if not necessary. The reason why the degree of freedom of the form of the housing 23 is increased is that it is located on the inner peripheral surface of the skin plate 1 that is not easily affected by natural ground.

  Each technical matter in any embodiment may be applied to other embodiments as an example.

DESCRIPTION OF SYMBOLS 1 Skin plate 2 Segment 3 Tail void 4 Backflow prevention blade 5 Segment fall prevention apparatus 10 Shield engraving machine 11 Skin plate rear end part 20 Back injection apparatus 21 Back injection pipe 22 Pressure gauge 23 Housing 23a Housing main body 23b Housing inclined part 23c Housing reinforcement part 24 Backing material A liquid injection pipe 25 Backing material B liquid injection pipe 26 Washing water pipe 27 Valve 28 Hydraulic piping 30 Spacer 31 Tail seal 32 Closure member 51, 52 Water stop zone S1 Lead shield tunnel S2 Trail shield tunnel

Claims (8)

A shield machine having a backfill injection device having a backfill injection tube and a housing covering the backfill injection tube,
The back-filling device is provided fixed to the inner peripheral surface of the skin plate,
A shield machine according to claim 1, wherein a tail seal is provided on an inner peripheral surface of the housing.   2. The shield machine according to claim 1, wherein the back-injection device is fixed to a part of a circumferential direction of an inner peripheral surface of the skin plate.   A spacer is provided on the inner peripheral surface of the skin plate and the back-filling device is not fixed, and a tail seal is provided on the inner peripheral surface of the spacer. The shield machine according to claim 2. The shield machine has a plurality of rows of tail seals;
The shield machine according to claim 3, wherein a plurality of the spacers are provided corresponding to the plurality of rows of tail seals.   The shield machine according to claim 4, further comprising a closing member that closes a space between the spacers. The shield machine has a plurality of rows of tail seals;
At the rear end of the housing, a tail seal of the last row is provided on the inner peripheral surface, and a spacer having an opening serving as a passage for the backing material is provided so as to be connected to the entire inner peripheral surface of the skin plate. The shield machine according to any one of claims 1 to 5, wherein the shield machine is provided. A shield machine having a backfill injection device having a backfill injection tube and a housing covering the backfill injection tube,
The back-filling device is provided fixed to a part of the circumferential direction of the inner peripheral surface of the skin plate,
A spacer is provided in a ring shape on the entire inner peripheral surface of the skin plate, and a tail seal is provided on the entire inner peripheral surface of the spacer.
The said shield is provided with the opening used as the channel | path of a backing material, The shield machine characterized by the above-mentioned.   A tunnel water stopping method for injecting a backing material into a tail void using the shield machine according to any one of claims 1 to 7.