JP2007023499A - Segment, water cut-off structure, and construction method for shield tunnel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a segment, a water cut-off structure, and a construction method for a shield tunnel for preventing underground water from intruding into a shield machine and a vertical shaft securely and preventing a back-filling material from running by straying off in the ground and being diluted securely by forming the tunnel by the segment provided with a wire brush at an arbitrary position in the axial direction of the shield tunnel and in the vicinity of a pit mouth of the vertical shaft. <P>SOLUTION: A row of wire brushes closed by assembling the segment 1a provided with the wire brush 2 on an outer peripheral face annularly are formed at an adequate position of the shield tunnel to form the water cut-off structure by filling the back-filling material behind the row of wire brushes and filling the back-filling material into tail void nipped by a row of wire brushes attached to an internal wall of a skin plate of the shield machine and a row of wire brushes formed by a plurality of segments 1a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a segment having a wire brush on its outer peripheral surface, a water stop structure comprising the segment, and a method for constructing a shield tunnel, and in particular, an arbitrary position in the axial direction of the shield tunnel and the vicinity of the shaft of the shaft By forming a tunnel with a segment with the wire brush, it is possible to reliably prevent groundwater from entering the shield machine and vertical shaft, and to prevent backfill material from running away and diluting. It is related with the construction method of the segment and water stop structure and shield tunnel which can be performed.

  When constructing pipes for infrastructure facilities such as water pipes, sewer pipes, gas pipes, telephone cable pipes, subway lines and underground passages in the ground, construction by shield method or propulsion method is used instead of excavation method from the ground. It has become the mainstream these days by the method. By the way, usually, a tail seal structure is provided in the vicinity of the rear end of the cylindrical skin plate that constitutes the excavator used in the shield construction method, thereby preventing the intrusion of groundwater into the excavator.

  The tail seal structure described above is constituted by a plurality of wire brush rows formed in an annular shape on the inner wall surface in the vicinity of the rear end of the skin plate constituting the shield machine as disclosed in Patent Documents 1 to 3. It has been a general structure so far.

JP 2005-68905 A JP 2000-328887 A JP 2001-355393 A

  In the inventions disclosed in Patent Documents 1 to 3 described above, the back-filling material is filled in the tail void sandwiched between the inner wall and segment of the skin plate and the annular wire brush projecting inward from the skin plate, thereby preventing water stoppage. Although the structure is constructed, there are often cases where the backfill material cannot be prevented from running away with the wire brush protruding only from the skin plate side, or the groundwater in the ground is wired to the filled backfill material. Infiltration between the brush and the segment can lead to dilution of the backfill material, and can often lead to cases where the backfill material cannot fully demonstrate the initial water stop effect.

  The segment, the water stop structure and the shield tunnel construction method of the present invention have been made in view of the above-mentioned problems, can reliably prevent the penetration of groundwater into a shield machine or a shaft, and It aims at providing the construction method of the segment which can prevent the ground runaway and dilution, etc., the water stop structure and the shield tunnel.

  In order to achieve the above object, a segment according to the present invention is a segment that constitutes a closed segment that is closed by assembling a plurality of segments in the circumferential direction at an appropriate position in the axial direction of the shield tunnel, A wire brush protruding from the outer peripheral surface at the outer peripheral surface, and by assembling a plurality of the segments in the circumferential direction of the shield tunnel, at an appropriate position in the axial direction of the shield tunnel, A wire brush array formed by closing the wire brushes is configured.

  The present invention relates to a segment having a wire brush on its outer peripheral surface, and by using such a segment with a wire brush as a plurality of segments closed in a circumferential direction at an appropriate position of a shield tunnel, A wire brush row is formed by closing the wire brush in the direction. Here, the target segment is a segment having an appropriate polarity, and a plurality of the segments are assembled in the ring direction to form a shield tunnel having a circular section, or a shield tunnel having a rectangular section. The shape of the segment, such as a plurality of segments constituting the, varies depending on the cross-sectional shape of the shield tunnel to be constructed. The material of the segment can also be applied to all conventionally known segments such as concrete and steel.

  As the wire brush, a known one attached to the skin plate can be used, and there is no particular limitation. For example, an intermediate protective plate made of spring steel is interposed between the bundles constituting the wire brush. By placing an aramid nonwoven fabric between the bundles of wire brushes, a wire brush structure that can cope with high water pressure can be obtained. Moreover, as a structure of a wire brush, what was pinched | interposed with the protection board which provided the spring effect on both sides of the wire brush used for the tail part of a shield machine can also be used. Further, with respect to the wire brush row, a plurality of wire brushes can be attached to the segment. In this case, a plurality of wire brush rows are arranged around a group of segments closed in the circumferential direction by the plurality of segments. Will be formed.

  The wire brush described above is desirably attached to the segment in a posture in which the attachment portion of the wire brush is accommodated in a cut formed in the outer peripheral surface of the segment, and welding, bolt joining, or the like can be applied to the attachment.

  As for the method of wrapping the wire brush between the segments, a wrap portion is provided in which the wire brush attached to the preceding piece segment is projected to the trailing piece segment side. As a configuration in which the wire brush is attached on the inner side of the segment, there is a method of assembling between adjacent segments while attaching the wrap portion to the attachment margin. Further, by taking measures such that the wire brush in the vicinity of the attachment portion between adjacent segments is kept in a dense state as compared with the other portions of the segment, a portion where the wire brush does not exist is generated in the segment joint portion. It is possible to form the wire brush row so that the portion does not become a water blocking inhibition portion.

  As described later, the segment of the present invention is used in an appropriate location (such as a groundwater stagnation area) where use is required in the vicinity of the shaft entrance of the shaft or in the axial direction of the shield tunnel. It is possible to improve and prevent dilution of the backfill material with groundwater, and further prevent backfill material from running out of the ground.

  Further, another embodiment of the segment according to the present invention is a segment constituting a closed segment that is closed by assembling a plurality of segments in the circumferential direction at an appropriate position in the axial direction of the shield tunnel, The outer peripheral surface is provided with a wire brush configured to be able to protrude from the outer peripheral surface, and a plurality of the segments are assembled in the circumferential direction of the shield tunnel, and the wire brush protrudes outward at a required time. The wire brush row is formed by closing the wire brush in the circumferential direction at an appropriate position in the axial direction of the shield tunnel.

  In the segment of the present invention, when the wire brush attached to the outer peripheral surface is attached, it is accommodated in, for example, a notch formed in the outer peripheral surface, and it is necessary to take measures against water stoppage with the wire brush. The invention relates to a segment that is configured such that, when it occurs, the wire brush can protrude outside the segment.

  For example, the surface of the wire brush is temporarily fixed with a tape or the like so that the wire brush does not protrude to the outer periphery of the segment in a posture in which the wire brush is accommodated in the notch, and the wire brush is provided at the time when the wire brush should be protruded. The wire brush can be configured to protrude to the outside of the segment by a method such as cutting the temporary fixing tape through the through hole. According to the segment of the present invention, when the segment is assembled at the tail portion of the shield machine and installed in the ground, the wire brush is damaged when there is no need for water stoppage by the wire brush. Etc. can be prevented.

  In another embodiment of the segment according to the present invention, the wire brush is accommodated in a notch formed in the outer peripheral surface of the segment, and a wire is provided by a backfill material provided from the inside of the segment to the outside. The brush protrudes from the outer peripheral surface of the segment.

  Tail voids that are generated when the shield machine is dug are filled with backfill material for the purpose of deforming the surrounding ground and water-blocking the tunnel. Here, examples of backfilling materials include cement-based materials composed of main materials and hardeners with different pot life, and high-viscosity materials composed of grease for the purpose of water-stopping. Can be mentioned. As a method for injecting the backfill material, there are a simultaneous injection method in which the backfill material is injected into the tail void from the shield machine side, and an immediate injection method in which injection is performed from an injection hole formed in the segment.

  In the present invention, the injection hole for immediate injection described above is provided in the segment, and this injection hole faces a notch formed in the outer side surface of the segment. The wire brush accommodated in the notch is projected outward by the injection pressure of the filling material. This is an efficient configuration utilizing immediate injection of the backfilling material, and is a desirable embodiment as a wire brush protruding method.

  The water stop structure according to the present invention is characterized in that the wire brush row formed by the segments can be formed in the ground near the entrance of the shaft, thereby preventing intrusion of groundwater into the shaft.

  Here, the vertical shaft means a starting vertical shaft or an intermediate vertical shaft for starting a shield excavating machine or an excavating machine in a propulsion method, and a reaching vertical shaft for reaching / accommodating the excavating machine. For example, the entrance of the start shaft is equipped with a rubber entrance packing to prevent groundwater and earth and sand from flowing into the shaft from the gap between the entrance and the shield machine or the entrance and the segment. It is common. Since the water stoppage becomes poor due to accumulation of excavated earth and sand on the back side (soil side) of this entrance packing, it is necessary to clean the back side of the entrance packing and then apply water stop injection, but the back side of the entrance packing If the excavated sediment is accumulated in the ground, there is a possibility that the groundwater may be attracted during the cleaning, or that additional sediment may be attracted.As a result, sufficient water stop injection cannot be performed, and the safety of the backside cleaning of the entrance packing can be improved. Problems have also been pointed out in the past.

  Therefore, by constructing a shield tunnel in the vicinity of the wellhead in the segment with the wire brush of the present invention, earth and sand and groundwater are blocked by the wire brush row, and therefore, the back side of the entrance packing can be safely washed. Since water stop injection can be performed in the cleaned space, it is possible to improve the water stop of the entrance.

  Further, another embodiment of the water stop structure according to the present invention is characterized by comprising the wire brush row constituted by the segments, and a backfill material filled in a tail void behind the wire brush row. To do.

  For example, as described above, the tail void formed by the drilling of the shield machine is defined into two regions by the wire brush row of the already formed segments, one region of which is the shield machine side, Since the wire brush which comprises a brush row | line | column protrudes from a segment and maintains the attitude | position which slidably contacted with the ground, it can prevent that groundwater flows in into a shield machine through a tail void. In this state, by immediately injecting the backfill material from the inside of the segment as described above, it is possible to configure a water stop structure composed of the wire brush row and the backfill material. Needless to say, this water stop structure can also prevent the ground from flowing into the shield machine through the tail void.

  Another embodiment of the water stop structure according to the present invention is that the skin plate constituting the shield machine extends from the inner wall surface of the skin plate near the rear end of the skin plate to the inside and closes in the circumferential direction of the inner wall surface. An excavator-side wire brush row configured to perform the above-described segment, the wire brush row constituted by the segment, and a tail void sandwiched by the wire brush row constituted by the excavator-side wire brush segment and the segment And a backfilling material filled in.

  The present invention relates to a wire brush row provided on an inner wall surface in the vicinity of the rear end of the skin plate of a shield machine that has been publicly known, a wire brush row that protrudes from a segment behind it and slides into contact with the ground, and their The present invention relates to a water stop structure composed of a backfill material filled in a tail void portion sandwiched therebetween. This water stop structure is temporarily formed according to the progress of the shield machine. For example, the backfilling material filled into the tail void by immediate injection from within the segment, and one of the skin plate The backfilling material is filled into the tail void in a posture protected by the wirebrush row formed on the inner wall surface and the other is protected by the wirebrush row protruding from the segment, so that it flows from the ground before the backfilling material is hardened. The problem that the backfill material is diluted by the incoming groundwater and the problem that the backfill material before hardening escapes into the ground can be solved. At the stage where the backfill material has developed the required strength (at the stage where it has reached the required hardening state), there is also a problem that groundwater flows into the shield machine through the tail void by excavating the shield machine. It will not be.

  Furthermore, the shield tunnel construction method according to the present invention is a shield tunnel construction method for constructing a shield tunnel composed of a first segment having a wire brush on its outer periphery and a second segment not having a wire brush. In addition, a wire brush row is formed in the vicinity of the wellhead of the starting vertical shaft to form a wire brush row that is in sliding contact with the inner wall surface of the ground excavated by assembling and closing the plurality of first segments in the circumferential direction. Form a weir and surround the plurality of first segments so that the plurality of second segments are sandwiched between two segment groups that are assembled and closed in the circumferential direction at appropriate positions in the axial direction of the shield tunnel. By assembling in the direction and closing, a wire brush row is formed that is in sliding contact with the inner wall surface of the excavated ground. Immediately inject the backfill material into the tail void from the inside of the segment, or back the tail void sandwiched between the wire brush row and the wire brush row provided on the inner wall surface at the rear end of the skin plate of the shield machine. Immediate injection or simultaneous injection of filling material, water stop construction is performed, and the shield machine is made to reach the intermediate shaft or the arrival shaft, and in the vicinity of the intermediate shaft or the arrival shaft, the same as the vicinity of the opening of the start shaft The water blocking weir is constructed by forming a wire brush row that is in sliding contact with the excavated ground.

  In the vicinity of the entrance of the start shaft and the end shaft (including the intermediate shaft), the water stop of the well is secured by the wire brush row formed by the segment with the wire brush and the water stop injection material, etc., in the axial direction of the shield tunnel In the area where groundwater may enter the shield machine through tail voids at appropriate locations, for example in water-stagnation areas, the wire brush trains are constructed using segments with wire brushes to It is possible to take a sure water stoppage measure in all tunnel sections from the wellhead to the shield tunnel to the reach shaft. Such water stop measures also lead to securing construction safety when cleaning the back side of the entrance packing at the wellhead and preventing construction of groundwater from entering the shield machine.

  As can be understood from the above description, according to the segment and the water stop structure and the shield tunnel construction method of the present invention, the water stop of the shaft shaft is improved by the wire brush attached to the segment, the inside of the shield machine through the tail void It is possible to prevent the intrusion of groundwater into the soil, dilute the filled backfilling material, and prevent ground escape.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a segment of the present invention, FIG. 2 is a schematic diagram showing a shield tunnel using the segment of the present invention in a part of the axial direction of the tunnel, and FIGS. The schematic diagram which showed the Example of the wire brush in the joint between segments is shown, respectively. FIG. 4 is a longitudinal sectional view showing the vicinity of the start shaft constructed by the shield tunnel construction method of the present invention, and FIGS. 5 to 7 are longitudinal sectional views sequentially showing the construction sequence at appropriate positions of the shield tunnel. 8a and 8b are longitudinal views showing other embodiments of the construction sequence at appropriate positions of the shield tunnel in the shield tunnel construction method of the present invention. Although the illustrated embodiment relates to a shield tunnel having a circular cross section, it is needless to say that the segment or water stop structure of the present invention corresponding to a shield tunnel having a square or rectangular cross section may be used. is there. Of course, the propulsion method is applicable to the waterstop structure near the entrance of the start shaft and the reaching shaft.

  FIG. 1 is a view showing an embodiment of a segment having a wire brush 2 on its outer peripheral surface. The wire brush 2 is configured in such a manner that wire pieces 21, 21, 21 in which a plurality of wires are bundled together, and intermediate plates 22, 22 made of spring steel are sandwiched therebetween, the wire brush 2 Are attached over the longitudinal direction of the segment 1a (in the direction of the inter-segment joint 1a2). The bottom of the wire brush 2 is fitted into a notch 1a1 formed in the outer peripheral surface of the segment 1a, and the end thereof is welded to the segment 1a (welded portion 91 in the figure), and the vicinity of the base of the wire brush 2 is observed. It is firmly attached with a plurality of bolts 92, 92,. An inter-ring joint 1a3 is provided on a side surface orthogonal to the side surface having the inter-segment joint 1a2, and a wire brush is provided on the outer peripheral surface of a conventionally known concrete or steel-made segment and a combination of concrete and steel. It has an attached configuration.

  FIG. 2 schematically shows a part of the shield tunnel 1 built in the ground, and a wire brush row composed of the wire brushes 2 is formed in the circumferential direction at an arbitrary position in the axial center direction. The situation that is being shown. The general part of the shield tunnel 1 forms a tunnel from normal segments 1b, 1b,... That do not have the wire brush 2, and the wire brush 2 is used in a tunnel section where measures such as water stoppage need to be focused. A tunnel is formed from the provided segments 1a, 1a,. In the schematic diagram shown in the figure, one wire brush row is shown, but in some cases, the wire brush row is formed in a continuous manner or formed at a predetermined interval. There are various examples according to the ground properties, groundwater stoppage status, groundwater pressure, and the like.

  FIG. 3 shows a situation in which the segments are to be assembled in the circumferential direction, and is generally performed by an erector apparatus in the shield machine. Here, in FIG. 3a, the wire brush 2 protrudes from the end (inter-segment joint surface) of the preceding segment 1a '(protruding portion 2a), and the end of the preceding segment 1a' is its end. The trailing segment 1a "having the mounting allowance 1a" 1 to which the wire brush protrusion 2a is attached is attached from the (inter-segment joint surface). Thus, in the preceding and succeeding segments, by providing both the protruding portion of the wire brush and the mounting allowance, and attaching both, it is possible to prevent the gap where the wire brush does not exist on the segment mounting surface. By preventing such a gap from occurring, it is possible to reliably achieve a water stop effect.

  FIG. 3 b shows another embodiment, in which the wire brush 2 is slightly protruded from the end of the preceding segment 1 a ′ and the end of the succeeding segment 1 a ″, and other parts are provided at the end 2 a of the wire brush 2. The number of wires is increased as compared with FIG. 3, and the purpose is to ensure the water stoppage of the wire brush connecting portion between adjacent segments as in FIG.

  Next, based on FIG. 4 to FIG. 7, the situation in the vicinity of the wellhead portion of the start pit 5 where water stop measures have been taken, and the situation in which the tail void is filled with the backfill material as the shield machine progresses are explained. Thus, the method for constructing the shield tunnel of the present invention will be described.

  FIG. 4 shows the situation in the vicinity of the entrance of the start shaft 5 where water stoppage measures have been taken. For example, a rubber entrance packing 6 is attached to a pit (entrance) drilled in the pit wall of the start shaft 5 in a manner along the shape of the opening. The shield machine starts in the ground through this wellhead, and a group of segments closed in a ring formed in the ground G while assembling ordinary segments 1b, 1b,. Installed. Here, in the tunnel construction method of the present invention, a segment group in which the segments 1a, 1a,. The wire brush row is projected to the outside (ground G side), and the tip of the wire brush 2 is brought into sliding contact with the inner wall surface of the ground hole. A shield tunnel is further constructed in front of the ground according to the excavation of the shield machine, a tail void is generated between the tunnel and the inner wall of the ground hole, and a backfill material is filled in the tail void. Become. The figure shows the situation where the back side of the entrance packing 6 was cleaned while the ground wire G1 was prevented from entering the ground by the annular wire brush row, and then the backfill material 3 for water stop was filled. Has been.

  5 to 7 show the procedure for filling the back void material into the tail void T while attaching the segment with the wire brush in the groundwater stagnation area and the high groundwater pressure area, etc., as the shield machine advances in the ground. Is shown. In the shield machine according to the embodiment shown in FIG. 5, two rows of wire brush rows 71, 71 that are annularly closed are provided on the inner wall surface in the vicinity of the rear end of the skin plate 7. Further, the segment 1a provided with the wire brush is provided with an injection hole 4 for immediately injecting the backfilling material from the inside of the segment, and the backfilling material is filled in the tail void through the infusion hose 8 communicating with the segment 1a. The

  In FIG. 5, when the shield machine is dug in the direction of the arrow X and the relative positional relationship between the skin plate 7 and the segment 1a as shown in FIG. 6 is reached, the rear end of the skin plate 7 as shown in FIG. The backfill material 3 is filled between the wire brush row 71 and the wire brush row composed of the wire brush 2 (arrow Y). Here, the wire brush row formed so as to protrude from the segment indicates that groundwater or the like enters the backfill material 3 filled through the tail void T formed at the rear of the wire brush row made of the wire brush 2. It is preventing. By maintaining this posture until the backfilling material 3 develops a predetermined strength, it is possible to effectively prevent the backfilling material 3 from escaping into the ground or diluting with groundwater, thereby ensuring reliable water stoppage. It leads to construction.

  FIG. 8 shows a construction method for filling the back void material into the tail void T using the segment 1a in which the wire brush is attached to the segment, which is different from that in FIG. As shown in FIG. 8a, all of the wire brushes 2 are accommodated in advance in the cuts 1a1 formed in the outer peripheral surface of the segment 1a, and a part of the surface cannot be protruded by the tape 10 on the outer peripheral surface of the segment. Assemble it with the posture temporarily fixed to. Here, the injection hole 4 for immediate injection of the backfill material is formed in the segment so as to face the notch 1a1.

  When the shield machine has been dug and the group of segments with the wire brush row is positioned behind the wire brush row 71 at the rearmost end of the skin plate 7 (FIG. 8b), the backfill material via the injection hose 8 4 is immediately injected (arrow X), and the tape 10 is peeled off by the injection pressure of the backfilling material 4, and the wire brush 2 in the accommodation posture protrudes outside the segment. The protruding tip of the wire brush 2 is in sliding contact with the inner wall surface of the ground to form a water blocking wall, and the back void material 4 is filled in the tail void T behind the water blocking wall.

  Of course, it is also possible to apply the embodiment of the segment 1a of FIG. 8 to the construction method of FIGS. Moreover, in embodiment of FIGS. 5-7 and embodiment of FIG. 8, not only immediate injection from the segment side but the form in which simultaneous injection from the skin plate side may be performed in parallel may be sufficient. That is.

  As described above, when water shield measures are taken while configuring wire brush rows at appropriate locations in the shield tunnel, when the shield excavator reaches an unillustrated reaching shaft (including intermediate shafts), the start shown in FIG. As in the vicinity of the shaft head of the shaft, measures against water stoppage to the shaft head are taken by the wire brush row protruding from the segment. Here, as one example of the construction on the reaching shaft side, after the shield excavator reaches the reaching shaft and the excavation of the ground is completed, the back side of the wire brush provided near the wellhead by the follow-up injection method The filler can be filled (if the wire brush is housed in the notch, the wire brush will protrude from the segment at this stage). After taking measures against water stoppage by the wire brush row, the shield machine is accommodated in the reaching shaft while the shield machine is idly pushed. When this shield machine is accommodated, since the measures against water stoppage are taken by the wire brush rows and backfilling materials provided near the wellhead, there is no problem that groundwater enters the reach shaft.

  As mentioned above, although embodiment of this invention has been explained in full detail using drawing, a concrete structure is not limited to this embodiment, Even if there is a change etc. in the range which does not deviate from the gist of the present invention. These are included in the present invention.

The perspective view which showed the segment of this invention. The schematic diagram which showed the shield tunnel which used the segment of this invention for a part of axial direction of a tunnel. (A), (b) is the schematic diagram which showed the Example of the wire brush in a joint between segments, respectively. The longitudinal section which showed the start vertical shaft vicinity constructed | assembled by the construction method of the shield tunnel of this invention. The longitudinal section which showed one Embodiment of the construction order in the appropriate position of a shield tunnel among the construction methods of the shield tunnel of this invention. FIG. 6 is a longitudinal sectional view illustrating the construction sequence at an appropriate position of the shield tunnel following FIG. 5. FIG. 7 is a longitudinal sectional view illustrating the construction sequence at an appropriate position of the shield tunnel following FIG. 6. (A), (b) is the longitudinal section which showed other embodiment of the construction order in the suitable position of a shield tunnel among the construction methods of the shield tunnel of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a, 1b ... Segment, 1a1 ... Notch, 1a2 ... Inter-segment joint, 1a3 ... Inter-ring joint, 2 ... Wire brush, 21 ... Wire piece, 22 ... Intermediate plate, 3 ... Backing material, 4 ... Injection hole, 5 ... Start shaft, 6 ... entrance packing, 7 ... skin plate, 71 ... wire brush, 8 ... injection hose, 91 ... weld, 92 ... bolt, 10 ... tape, T ... tail void

Claims (7)

A segment constituting a closed segment that is closed by assembling a plurality of segments in the circumferential direction at an appropriate position in the axial direction of the shield tunnel,
The segment is provided with a wire brush protruding from the outer peripheral surface at the outer peripheral surface thereof, and by assembling a plurality of the segments in the circumferential direction of the shield tunnel, the segment is arranged at an appropriate position in the axial direction of the shield tunnel. A segment comprising a wire brush row formed by closing wire brushes in a circumferential direction. A segment constituting a closed segment that is closed by assembling a plurality of segments in the circumferential direction at an appropriate position in the axial direction of the shield tunnel,
The segment is provided with a wire brush configured to protrude from the outer peripheral surface at the outer peripheral surface thereof, and the plurality of segments are assembled in the circumferential direction of the shield tunnel, and the wire brush protrudes outward at a required time. A segment comprising a wire brush row formed by closing the wire brush in the circumferential direction at an appropriate position in the axial direction of the shield tunnel. The segment of claim 2,
The wire brush is accommodated in a cut formed in the outer peripheral surface of the segment, and the wire brush protrudes from the outer peripheral surface of the segment by a backfill material provided from the inside of the segment to the outside. To be segmented.   The water-stop type | mold comprised by the segment in any one of Claims 1-3 can prevent intrusion to the shaft of groundwater by being formed in the ground near the shaft head of a shaft. Construction.   A waterstop structure comprising the wire brush row constituted by the segments according to any one of claims 1 to 3, and a backfill material filled in a tail void behind the wire brush row.   Of the skin plates constituting the shield machine, the wire brush row on the machine side configured to protrude from the inner wall surface of the skin plate near the rear end thereof and close in the circumferential direction of the inner wall surface, The back filled with the tail void sandwiched between the wire brush row constituted by the segment according to any one of claims 1 to 3, the wire brush row on the excavator side, and the wire brush row constituted by the segment A water stop structure characterized by comprising a filling material. A shield tunnel construction method for constructing a shield tunnel composed of a first segment having a wire brush on its outer periphery and a second segment not having a wire brush,
In the vicinity of the entrance of the starting shaft, a water brush weir is formed by forming a wire brush row that is in sliding contact with the inner wall surface of the ground excavated by assembling and closing the plurality of first segments in the circumferential direction. Then, at an appropriate position in the axial direction of the shield tunnel, the plurality of first segments are assembled in the circumferential direction so that the plurality of second segments are sandwiched between the two segment groups that are assembled and closed in the circumferential direction. By attaching and closing, a wire brush row slidably contacting the inner wall surface of the excavated ground is formed, and a backfill material is immediately injected into the tail void behind the wire brush row from within the segment, or the wire brush row Immediate injection or simultaneous injection of backfilling material into the tail void sandwiched between the wire brush row provided on the inner wall of the rear surface of the shield plate of the shield machine A wire brush that slides in contact with the excavation ground in the vicinity of the entrance of the start shaft, near the entrance of the start shaft, or near the entrance of the start shaft. A method for constructing a shield tunnel, characterized in that a water blocking weir is constructed by forming a row.

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