Water-stopping method for wellhead

Abstract

To provide a shield driving method using a shield machine special in a front view shape allowing cutting-off of a pit mouth to be securely carried out even when a width of a starting shaft is small as well as a cutting-off state of the pit mouth to be kept even after the shield machine advances and after facilities projected from the pit mount to the starting shaft side is removed.SOLUTION: A cutting-off method of a pit mouth comprises: a first assembly process assembling temporary segments S1, S2 at a rear part of a shield machine 100 positioned in a pit mouth Sb; a second assembly process assembling tunnel wall bodies W1, W2 so as to be connected on the temporary segments S1, S2; a placing process placing in the temporary segments S1, S2 a cutting-off member 200 having a shape sealing a space formed between a packing P1 and rear end portions W11, W21 of the tunnel wall bodies W1, W2; a pushing-in process pushing-in the cutting-off member 200; and a fastening process fastening the cutting-off member on the rear end portions W11, W21.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to a method for watertightly closing a wellhead. [Background technology]

[0002] The H&V (Horizontal variation & Vertical variation) method, which is one of the shield tunneling methods, is a method in which excavation is carried out using two connected shield machines. When each shield machine advances and its front end leaves the side wall of the starting shaft (improved ground) and enters the natural ground, a water path is formed between the two tunnel walls assembled behind each shield machine.

[0003] In order to prevent water from leaking into the starting shaft from this water path, various techniques have been proposed to stop water leaking from the shaft entrance in the H&V construction method. For example, Patent Document 1 describes a technique in which a pair of integrated segments is installed at the rear end of a shield machine and the integrated segments are advanced together with the shield machine. Patent Document 1 also introduces as prior art a technology in which a parent entrance and a child entrance that can be separated, each equipped with a sealing member, are pushed into the tunnel entrance, and water is stopped at the parent entrance when the shield machine penetrates, and at the child entrance when the segment penetrates. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-094181 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in order to push the wellhead entrance and integrated segment into the wellhead as described in Patent Document 1, it is necessary to install a large-scale (space-consuming) propulsion facility in the starting shaft. However, if the width of the starting shaft is small, it is difficult to install such propulsion facility. In addition, the diameter of the tunnel wall is generally one size smaller than that of the shield machine. Therefore, in the water-stopping method using integrated segments as described in Patent Document 1, when the shield machine advances and the member in contact with the packing at the tunnel entrance moves from the skin plate to the integrated segment, water is likely to leak out between the packing and the integrated segment.

[0006] Furthermore, in the conventional water-stopping method using a parent-child entrance, which was introduced as a conventional technology in Patent Document 1, when the child entrance protruding from the tunnel entrance toward the starting shaft is finally removed, there is a possibility that water may leak out from between the tunnel entrance gasket and the tunnel wall. On the other hand, if the sub-entrance were to be left in place to prevent flooding, it would protrude into the departure shaft, causing problems when constructing the structure inside the departure shaft.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to enable, in a shield construction method using a shield machine with a special front-view shape, to reliably seal off water at the mine entrance even when the starting shaft is small in width, and to enable the mine entrance to remain watertight even after the shield machine has advanced or equipment protruding from the mine entrance toward the starting shaft has been removed. [Means for solving the problem]

[0008] In order to solve the above problem, the invention according to claim 1 comprises: A method for stopping water at a tunnel entrance provided on a side wall of a starting shaft of a shield machine, comprising: A first assembly process of assembling temporary segments in the starting shaft at a rear part of the shield machine located in the shaft entrance; a second assembly process in which the shield machine is advanced and a tunnel wall body consisting of a plurality of segments is assembled in the tunnel entrance so as to be connected to temporary segments; a placement process for placing a water-stopping member having a shape for closing a space formed between a packing provided along the inner circumferential surface of the tunnel entrance and the rear end of the tunnel wall on the temporary segment so as to surround the temporary segment; a pushing step of pushing the water-stopping member disposed around the temporary segment between the packing and the rear end portion; a fixing step of fixing the water-stopping member, which is pressed between the packing and the rear end portion, to the rear end portion; A method for watertightness at a wellhead, comprising:

[0009] The invention according to claim 2 is as follows: The water-stopping method for a wellhead according to claim 1, The water-stopping member used is characterized in that its width in the direction of travel of the shield machine does not exceed the distance from the rear end of the gasket to a second gasket provided on the inner surface of the tunnel entrance, closer to the ground than the gasket.

[0010] The invention according to claim 3 is as follows: The water-stopping method for a wellhead according to claim 1 or 2, The shield machine includes: The first aircraft is circular when viewed from the front, A second airframe having a circular shape when viewed from the front, arranged in a direction perpendicular to the traveling direction of the first airframe; a fuselage connection portion for connecting the first fuselage and the second fuselage, As the water-stopping member, a first annular portion surrounding a first tunnel wall assembled at the rear of the first fuselage; a second annular portion surrounding a second tunnel wall assembled at the rear of the second fuselage; The present invention is characterized in that the first annular portion and the second annular portion are connected to each other by a member connecting portion that connects the first annular portion and the second annular portion while blocking the space between the first annular portion and the second annular portion.

[0011] The invention according to claim 4 is as follows: The water-stopping method for a wellhead according to claim 3, At least one of the first annular portion and the second annular portion is made of a plurality of arc-shaped members as the water-stopping member, The placing step is characterized in that at least one of the first annular portion and the second annular portion is placed around the corresponding temporary segment by connecting a plurality of arc-shaped members together.

[0012] The invention according to claim 5 is as follows: The water-stopping method for a wellhead according to claim 4, As one of the arc-shaped members, a member having a joint surface at an end portion thereof, which is located between the inner peripheral surface and the outer peripheral surface of the corresponding annular portion and faces the center of the annular portion, is used, As the other arc-shaped member to be joined to the one arc-shaped member, a member having a joined surface at an end portion thereof, the joined surface being located between the inner peripheral surface and the outer peripheral surface of the annular portion and facing the joining surface is used, The positioning step is characterized in that the joining surface and the joined surface are brought into contact with each other, and one of the arc-shaped members and the other of the arc-shaped members are lap-welded.

[0013] The invention according to claim 6 is as follows: The water-stopping method for a wellhead according to any one of claims 3 to 5, As the water-stopping member, The member connection portion can be divided into a first member located on a first direction side perpendicular to the direction in which the first body and the second body are arranged and the shield machine traveling direction, and a second member located on the opposite side to the first direction, The first member and the second member are characterized in that they can be joined by a bolt. Effect of the Invention

[0014] According to the present invention, in a shield construction method using a shield machine with a special front view shape, water can be reliably stopped at the mine entrance even if the starting shaft is small in width, and the mine entrance can be kept watertight even after the shield machine moves forward or equipment protruding from the mine entrance toward the starting shaft is removed. [Brief description of the drawings]

[0015] [Figure 1] 1 is a front view showing a shield machine used in a shield construction method to which a water stopping method for a mine entrance according to a first embodiment of the present invention is applied. FIG. [Diagram 2] 1 is a side view showing a shield machine located in the natural ground and a tunnel wall assembled by the shield machine. FIG. [Diagram 3] 1A is a side view showing the shield machine at an early stage of construction, and FIG. 1B is a side view showing the shield machine after FIG. 1A and the tunnel wall assembled by the shield machine. [Figure 4] 3 is a front view of a water-stopping member used in the water-stopping method. FIG. [Diagram 5] 5 is a partial enlarged view of the portion (joint) surrounded by A in FIG. 4. [Figure 6] 5A is a partial enlarged view of the portion (member connection portion) surrounded by B in FIG. 4, and FIG. 5B is a cross-sectional view taken along CC in FIG. [Figure 7] FIG. 5 is a cross-sectional view taken along the line DD in FIG. [Figure 8] FIG. 2 is a vertical cross-sectional view showing the shield tunnel in the first assembly process. [Figure 9] FIG. 11 is a vertical cross-sectional view showing the shield tunnel in the second assembly process. [Figure 10] FIG. 11 is a vertical cross-sectional view showing the shield tunnel in the placement process. [Figure 11] FIG. 11 is a vertical cross-sectional view showing the shield tunnel in a pushing process. [Figure 12] FIG. 11 is a vertical cross-sectional view showing the shield tunnel in a fixing process. [Figure 13] This is a front view and a vertical cross-sectional view showing the mine entrance after water has been stopped. [Figure 14] FIG. 11 is a front view showing a shield machine used in a shield construction method to which a water-stopping method for a mine entrance according to a second embodiment of the present invention is applied. [Figure 15] 3 is a front view of a water-stopping member used in the water-stopping method. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] <1. First embodiment> Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. However, the technical scope of the present invention is not limited to the following embodiments and examples shown in the drawings.

[0017] [1-1. Shield machine] First, a shield machine 100 used in a shield construction method to which a water stopping method for a tunnel entrance according to this embodiment (hereinafter, a water stopping method) is applied will be described. Figure 1 is a front view of the shield machine 100, Figure 2 is a side view of the shield machine 100 positioned in the ground and the tunnel wall assembled by the shield machine 100, Figure 3(a) is a side view of the shield machine 100 at the early stage of construction, and Figure 3(b) is a side view of the shield machine 100 at a period after (a) and the tunnel wall assembled by the shield machine 100.

[0018] The shield machine 100 according to this embodiment is used in an H&V (Horizontal variation & Vertical variation) construction method. Moreover, the shield machine 100 according to this embodiment has a first machine body 1, a second machine body 2, and a machine body connection section 3, as shown in FIG.

[0019] The first body 1 is circular in front view (has a circular cutter). In addition, as shown in FIG. 2, the first body 1 assembles a cylindrical first tunnel wall body W1 made up of a plurality of segments at its rear (the space created by the excavation).

[0020] As shown in FIG. 1, the second body 2 is circular when viewed from the front, similar to the first body 1. Although FIG. 1 illustrates the second body 2 having a smaller diameter than the first body 1, the diameter of the second body 2 may be the same as that of the first body 1 or may be larger. The second body 2 is arranged next to the first body 1 in a direction perpendicular to the traveling direction of the first body 1 (for example, in the up-down direction as shown in Figs. 1 and 2). In addition, as shown in FIG. 2, the second body 2 assembles, at its rear, a cylindrical second tunnel wall body W2 made up of a plurality of segments.

[0021] The fuselage connection portion 3 is located between the first fuselage 1 and the second fuselage 2, and connects the first fuselage 1 and the second fuselage 2 together. When the shield machine 100 is used to continuously create two tunnels that run parallel from start to finish, the machine body connection section 3 may be completely connected (inseparable) to the first and second machine bodies 1, 2. On the other hand, when the shield machine 100 is used to create a tunnel that branches off midway, the machine body connecting portion 3 may be configured to be detachable from the first and second machine bodies 1, 2.

[0022] As the shield machine 100 configured in this manner advances while excavating the ground, the ground between the first body 1 and the second body 2 is excavated by the copy cutter of the first body 1 or the second body 2 and taken into the first body 1 or the second body 2, so that no ground remains between the first tunnel wall body W1 assembled by the first body 1 and the second tunnel wall body W2 assembled by the second body 2. Moreover, the first tunnel wall body W1 and the second tunnel wall body W2 each have an independent cylindrical shape (as shown in FIG. 2, the first tunnel wall body W1 and the second tunnel wall body W2 are spaced apart from each other).

[0023] As shown in FIG. 3(a), while the front end of the shield machine 100 is in contact with the side wall Sa of the starting shaft S, the groundwater in the natural ground G is blocked by the side wall Sa, so that the groundwater does not flow behind the shield machine 100. However, as shown in FIG. 3(b), when the shield machine 100 advances and its front end leaves the side wall Sa and enters the natural ground G behind it, the groundwater flows behind the shield machine 100 through the gap between the side wall Sa and the shield machine 100, and a water path P is formed between the first tunnel wall body W1 and the second tunnel wall body W2. W become.

[0024] [1-2.Water-stopping materials] Next, a water-stopping member 200 used in the water-stopping method according to the embodiment of the present invention will be described. 4 is a front view of the water-stopping member 200, FIG. 5 is a partially enlarged view of the portion surrounded by A in FIG. 4, FIG. 6(a) is a partially enlarged view of the portion surrounded by B in FIG. 4, FIG. 6(b) is a cross-sectional view taken along line CC in FIG. 4, and FIG. 7 is a cross-sectional view taken along line DD in FIG. 4.

[0025] As shown in FIG. 4, the water-stopping member 200 according to this embodiment has a first annular portion 4, a second annular portion 5, and a member connecting portion 6. In the waterproof member 200 according to this embodiment, each of the sections 4 to 6 is formed from a steel material.

[0026] The first annular portion 4 surrounds the first temporary segment S1 or the first tunnel wall W1 which is assembled at the rear of the first body 1 of the shield machine 100. The outer diameter of the first annular portion 4 according to this embodiment is substantially equal to the outer diameter of the first body 1 . The inner diameter of the first annular portion 4 is slightly larger than the outer diameter of the first tunnel wall body W1 (for example, to the extent that a gap of 5 mm is formed). The first annular portion 4 according to the present embodiment is made up of a plurality of arc-shaped members 41. As shown in Figure 5, one arc-shaped member 41 in this embodiment has a joining surface 41a at its end that is located between the inner surface 4a and the outer surface 4b of the first annular portion 4 (corresponding annular portion) and faces the center of the first annular portion 4. Another arc-shaped member 41 to be joined to one arc-shaped member 41 has, at its end, a joined surface 41b located between the inner peripheral surface 4a and the outer peripheral surface 4b and facing the joining surface 41a.

[0027] The second annular portion 5 surrounds the second temporary segment S2 or the second tunnel wall W2 which is assembled at the rear of the second body 2 of the shield machine 100. The outer diameter of the second annular portion 5 according to this embodiment is substantially equal to the outer diameter of the second body 2 . The inner diameter of the second annular portion 5 is slightly larger than the outer diameter of the second tunnel wall body W2 (for example, to the extent that a gap of 5 mm is formed). The second annular portion 5 according to this embodiment is made up of a plurality of arc-shaped members 51, as shown in FIG. As shown in FIG. 5, each of the arcuate members 51 has a joining surface 51a or a joined surface 51b at an end, similar to each of the arcuate members 41 of the first annular portion 4.

[0028] As described above, the first and second annular portions 4, 5 in this embodiment are made up of a plurality of arc-shaped members 41, 51, each of which has a joining surface 41a, 51a or a joined surface 41b, 51b, thereby making it easy to position the water-stopping member 200 around a large-diameter temporary segment (described in detail later). Furthermore, even if an assembly error, deformation, or the like occurs in the temporary segment, the diameters and shapes of the first and second annular portions 4, 5 can be adapted to the assembly error, deformation, or the like of the temporary segment. In addition, since the adjacent arc-shaped members 41, 51 do not have uneven surfaces, the inner circumferential surfaces 4a, 5a and the outer circumferential surfaces 4b, 5b of the first and second annular portions 4, 5 become smooth.

[0029] The member connecting portion 6 connects the first annular portion 4 and the second annular portion 5 while closing the gap between the first annular portion 4 and the second annular portion 5. As shown in FIG. 4, the shape of the member connecting portion 6 in a front view is substantially the same as the shape of the machine body connecting portion 3 in a front view (see FIG. 1). As shown in Figure 6, the member connection portion 6 in this embodiment can be divided into a first member 61 located on the first direction side (e.g., the left side in Figure 6) perpendicular to the direction in which the first body 1 and the second body 2 are aligned (the up and down direction in Figure 6(a)) and the traveling direction of the shield machine 100 (the direction perpendicular to the paper surface in Figure 6(a)), and a second member 62 located on the opposite side to the first direction (e.g., the right side in Figure 6).

[0030] The first and second members 61, 62 have, at their ends, joining surfaces 61a, 62a or joined surfaces 61b, 62b similar to those of the arcuate members 41, 51 of the first and second annular portions 4, 5, respectively.

[0031] In addition, the member connecting portion 6 is configured so that the first member 61 and the second member 62 can be joined by a bolt 63 . As shown in FIG. 6(b), the member connecting portion 6 according to this embodiment is configured such that a first member 61 and a second member 62 are joined together by a plurality of bolts 63. Moreover, in the member connecting portion 6 according to this embodiment, the bolt 63 is screwed into the inside of the first and second members 61,62. The first and second members 61, 62 have openings 61c, 62c at positions corresponding to the head of the bolt 63. Therefore, even when the member connecting portion 6 is positioned between the first and second tunnel wall bodies W1, W2, the bolt 63 can be turned by passing a tool through the openings 61c, 62c.

[0032] The water-stopping member 200 is designed so that its width w (see Figure 6(b)) in the direction of travel of the shield machine 100 does not exceed a distance d1 (see Figure 8) from the rear end (the end on the starting shaft S side, ≒ the inner wall surface of the shaft entrance concrete Sc) of a gasket P1 provided along the inner surface of the shaft entrance concrete Sc formed around the shaft entrance Sb on the side wall Sa of the starting shaft S to a second gasket P2 provided on the inner surface of the shaft entrance concrete Sc closer to the ground (a part not shown that is located in the direction of travel of the shield machine than the side wall Sa) than the gasket P1. The waterproof member 200 according to this embodiment is further configured so that the distance from the rear end of the packing P1 to the front end (the end on the ground side) of the packing P1 does not exceed a distance d2 (for example, about 300 mm).

[0033] In the water-stopping member 200 according to this embodiment, the front end portion of the inner circumferential surface 4a of the first annular portion 4 is chamfered as shown in FIG. In addition, in the water-stopping member 200 of this embodiment, the front end portion of the inner surface 5a of the second annular portion 5 and the surface at the member connecting portion 6 that continues with the inner surfaces 4a, 5a of the first and second annular portions 4, 5 are also chamfered.

[0034] In this example, the water-stopping member 200 is exemplified as one in which the outer diameters of the first and second annular portions 4, 5 are both approximately equal to the outer diameters of the first and second bodies 1, 2; however, the outer diameter of the first annular portion 4 or the second annular portion 5 may be different from the outer diameter of the corresponding body. Further, here, the water-stopping member 200 is exemplified as one in which the first and second annular portions 4, 5 are both made of arc-shaped members 41, 51, but the first annular portion 4 or the second annular portion 5 may not be divided into a plurality of arc-shaped members. Further, although an assembled water-stopping member 200 has been exemplified here, the water-stopping member 200 is usually divided into a plurality of members 41, 51, 61, and 62 before the water-stopping method is carried out.

[0035] [1-3. Water-stopping method at the mine entrance] Next, a waterproofing method using the waterproofing member 200 will be described. 8 to 12 are longitudinal sectional views showing the shield tunnel during construction, and FIG. 13 is a front view and longitudinal sectional view showing the tunnel entrance after water has been stopped. 8 to 12 refer to elements of a second embodiment described later.

[0036] This water stopping method is for performing water stopping at a well entrance Sb provided in a side wall Sa (well entrance concrete Sc) of a starting shaft S of the shield machine 100 in the construction of a shield tunnel using the above-mentioned shield machine 100. This water-stopping method includes a first assembly step, a second assembly step, a positioning step, a pushing step, and a fixing step. Although Figures 8 to 12 illustrate a shield machine 100 in which the first body 1 and the second body 2 are arranged vertically, the shield machine 100 in this case may also have the first body 1 and the second body 2 arranged horizontally.

[0037] (First assembly process) In the first assembly process, as shown in Fig. 8, the rear part 100a of the shield machine 100 protrudes from the tunnel entrance Sb into the starting shaft S. At this time, the temporary segments S1 and S2 are assembled in the rear part 100a of the shield machine 100, which is located inside the starting shaft S and at the tunnel entrance Sb. As described above, in the shield construction method of this embodiment, a shield machine 100 having a first body 1 and a second body 2 is used, and therefore, in the first assembly process of this embodiment, a first temporary segment S1 is assembled at the rear of the first body 1, and a second temporary segment S2 is assembled at the rear of the second body 2. In addition, since the first and second temporary segments S1, S2 are intended to obtain a reaction force when the shield machine 100 moves forward, in the first assembly process of this embodiment, the first and second temporary segments S1, S2 are assembled so that their rear ends are supported on the side wall Sa opposite the mine entrance Sb in the starting shaft S and extend toward the mine entrance Sb. Moreover, the first and second temporary segments S1, S2 are connected to the tunnel wall bodies W1, W2 which will be subsequently assembled by the shield machine 100. For this reason, in the first assembly process according to this embodiment, the multiple first temporary segments S1 are assembled into a cylindrical shape having the same diameter as the first tunnel wall body W1, and the multiple second temporary segments S2 are assembled into a cylindrical shape having the same diameter as the second tunnel wall body W2.

[0038] (Second assembly process) After the temporary segments are assembled, the second assembly process begins. In this second assembly process, as shown in Figure 9, the shield machine 100 is advanced and the first and second tunnel wall bodies W1, W2, consisting of multiple segments, are assembled so as to be connected to the first and second temporary segments S1, S2. In addition, in the second assembly process according to this embodiment, a cylindrical first tunnel wall body W1 having the same diameter as the first temporary segment S1 is connected to the end of the first temporary segment S1 so that their annular end faces contact each other, and a cylindrical second tunnel wall body W2 having the same diameter as the second temporary segment S2 is connected to the end of the second temporary segment S2 in the same manner as when the first tunnel wall body W1 is connected to the first temporary segment S1.

[0039] (Placement process) After starting to assemble the first and second tunnel wall bodies W1, W2, the placement process begins. In this arrangement process, as shown in FIG. 10, the first and second temporary segments S1 and S2 are fitted with packings P1 provided along the inner circumferential surface of the portal concrete Sc and the rear end portions W1 and W2 of the first and second tunnel wall bodies W1 and W2. 11 ,W 21 A waterproof member 200 having a shape for blocking the space between the first and second temporary segments S1, S2 is disposed so as to surround the periphery of the first and second temporary segments S1, S2. As described above, the first and second tunnel walls W1, W2 are respectively connected to a plurality of first and second temporary segments S1, S2 assembled into a cylindrical shape, so that in the water-stopping method of this embodiment, a water-stopping member 200 having a first annular portion 4, a second annular portion 5, and a member connecting portion 6 (shaped like an eight when viewed from the front) as shown in Figure 4 is used.

[0040] In the water stopping method according to the present embodiment, the first and second annular portions 4, 5 are made up of a plurality of arc-shaped members 41, 51, as described above. Therefore, in the arrangement step according to this embodiment, the first and second annular portions 4, 5 are arranged around the first and second temporary segments S1, S2 (corresponding temporary segments) by connecting a plurality of arc-shaped members together. This makes it possible to easily arrange the waterproofing member 200 around the first and second temporary segments S1, S2 which have a larger diameter.

[0041] In the arrangement step according to this embodiment, the joining surfaces 41a, 51a and the joined surfaces 41b, 51b are brought into contact with each other, and one arc-shaped member 41, 51 and another arc-shaped member 41, 51 are lap-welded. In addition, in the placement process of this embodiment, the joining surface 41b of the arc-shaped member 41 is brought into contact with the joining surfaces 61a, 62a of the first and second members 61, 62, and the arc-shaped member 41 and the first and second members 61, 62 are lap welded from the outer circumferential surface 4b side. Furthermore, the joining surface 51a of the arcuate member 51 and the joined surfaces 61b, 62b of the first and second members 61, 62 are brought into contact with each other, and the arcuate member 51 and the first and second members 61, 62 are lap-welded from the outer circumferential surface 5b side.

[0042] Furthermore, in the water-stopping method according to this embodiment, a water-stopping member 200 is used in which the member connection portion 6 can be separated into a first member 61 and a second member 62, and the first member 61 and the second member 62 can be joined with a bolt 63. In addition, in the arrangement process of this embodiment, all of the arc-shaped members 41, 51 are connected together, and the arc-shaped members 41, 51 at the ends of the first and second annular portions 4, 5 are connected to the first and second members 61, 62, and finally the first member 61 and the second member 62 are joined with a bolt 63. By doing this, even if assembly errors, deformations, etc. occur in the first and second temporary segments S1, S2, the diameters and shapes of the first and second annular portions 4, 5 can be adapted to the assembly errors, deformations, etc. of the first and second temporary segments S1, S2.

[0043] In addition, in the water-stopping method according to this embodiment, as shown in FIG. 5, one arc-shaped member 41 has a joining surface 41a at its end, and another arc-shaped member to be connected to the one arc-shaped member 41 has a joining surface 41b at its end. In this way, the adjacent arc-shaped members 41, 51 do not have uneven surfaces, so that the inner circumferential surfaces 4a, 5a and the outer circumferential surfaces 4b, 5b of the first and second annular portions 4, 5 become smooth.

[0044] When the waterproofing member 200 is installed around the first and second temporary segments S1, S2 in the above manner, the first annular portion 4 surrounds the first temporary segment S1, and the second annular portion 5 surrounds the second temporary segment S2. In the arrangement process according to this embodiment, the multiple arc-shaped members 41, 51 and the first and second members 61, 62 are connected together around the first and second tunnel wall bodies W1, W2, but they may also be connected together at a different location (to form a water-stopping member 200) and passed through the first and second tunnel wall bodies W1, W2.

[0045] (Pushing process) After the water-stopping member 200 is placed, the process moves to a pushing step. In this pushing step, as shown in FIG. 11, the water-stopping member 200 arranged around the first and second temporary segments S1 and S2 is pushed into the packing P1 and the rear end portions W of the first and second tunnel wall bodies W1 and W2. 11 ,W 21 (The part on the S side of the starting shaft) and push it in between. As described above, in the water-stopping method according to the present embodiment, the water-stopping member 200 having the first annular portion 4, the second annular portion 5, and the member connecting portion 6 is used, so that the first annular portion 4 is connected to the packing P1 and the rear end portion W of the first tunnel wall W1. 11 and the second annular portion 5 is inserted between the packing P1 and the rear end W of the second tunnel wall W2. 21 Push it in between. At that time, the member connecting portion 6 is connected to the rear end portion W of the first tunnel wall body W1. 11 and the rear end W of the second tunnel wall W2 21 It will be pushed in between.

[0046] In the pushing step according to this embodiment, the rear end portion of the shield machine 100 pushes in the waterstop member 200 during the period from when it leaves the packing P1 to when it leaves the second packing P2. In this way, while the second gasket P2 blocks the groundwater seeping out from the ground, the water-stopping member 200 blocks the mine entrance Sb, making it possible to stop water from leaking out of the mine entrance Sb without any groundwater leaking into the starting shaft S.

[0047] In addition, in the water-stopping member 200 used here, the front end portions of the inner circumferential surfaces 4a, 5a of the annular portions 4, 5 are chamfered as shown in FIG. Therefore, even if unevenness occurs on the outer peripheral surfaces of the multiple first and second temporary segments S1 and S2 assembled into a cylindrical shape due to assembly errors, deformation, etc. of the first and second temporary segments S1 and S2, it is possible to prevent the front end of the water-stopping member 200 from getting caught on the unevenness, making it difficult to push the water-stopping member 200 in.

[0048] Furthermore, as described above, the water-stopping member 200 used here is designed so that its width w (see Figure 6(b)) in the direction of travel of the shield machine 100 does not exceed the distance d1 (see Figure 8) from the rear end of the gasket P1 to the second gasket P2. As a result, the mine entrance Sb can be blocked at the stage when the rear end of the shield machine 100 is in contact with the second gasket P2, and the water-stopping member 200 will not protrude into the starting shaft S after blocking the mine entrance Sb.

[0049] As described above, in the water-stopping member 200 used here, the outer diameter of the first annular portion 4 and the outer diameter of the second annular portion 5 are equal to the outer diameter of the corresponding aircraft body. For this reason, the packing P1 presses the waterstop member 200 with the same strength (no step drop) as when it was in contact with the skin plate of the shield machine 100. As a result, it is possible to reduce the risk of water leaking when the member in contact with the packing P1 is replaced from the skin plate to the waterstop member 200.

[0050] As described above, the outer peripheral surfaces 4b, 5b of the water-stopping member 200 according to this embodiment are smooth, so that the outer peripheral surfaces 4b, 5b of the water-stopping member 200 are in close contact with the packing P1 over their entirety after the pushing step. Therefore, by using the water-stopping member 200 according to this embodiment, an additional step of sealing the gap between the packing P1 and the water-stopping member 200 is not required.

[0051] (Adhesion process) After the waterproofing member 200 is pushed in, the process moves to a fixing step. In this fixing process, the packing P1 and the rear end W of the first and second tunnel walls W1 and W2 are 11 ,W 21 The water-stopping member 200 is inserted between the rear end W 11 ,W 21 Fix it to. The water-stopping member 200 according to this embodiment is made of steel as described above. Therefore, in the fastening process according to this embodiment, the water-stopping member 200 is fixed to the rear end portions W of the first and second tunnel wall bodies W1 and W2 by welding. 11 ,W 21 The plates are then fixed to the respective positions. At that time, as shown in FIG. 11 ,W 21 All of the gaps between the first and second tunnel wall bodies W1, W2 and the inner circumferential surfaces 4a, 5a of the water-stopping member 200 are blocked by the filler material M. This makes it impossible for water to pass between the first and second tunnel wall bodies W1, W2 and the water-stopping member 200. As described above, since the inner circumferential surfaces 4a, 5a of the water-stopping member 200 are smooth, the installer can easily weld the water-stopping member 200 to the first and second tunnel wall bodies W1, W2.

[0052] (After water is stopped) After the water-stopping member 200 is fixed, as shown in Figure 13, the space between the packing P1 of the portal concrete Sc and the first tunnel wall W1 is blocked by the first annular portion 4 and filler material M, and the space between the packing P1 and the second tunnel wall W2 is blocked by the second annular portion 5 and filler material M. At that time, the gap between the first tunnel wall body W1 and the second tunnel wall body W2 is also blocked by the packing P1, the member connecting portion 6, and the filler material M. Thereafter, when the shield machine 100 advances and the rear end of the shield machine 100 separates from the second packing P2, groundwater seeping out from the natural ground fills the area around the first and second tunnel wall bodies W1, W2. However, the area between the packing P1 of the tunnel entrance concrete Sc and the first and second tunnel wall bodies W1, W2 is blocked by the packing P1, the member connection part 6, and the filler material M, so the groundwater does not overflow into the starting shaft S.

[0053] [1-4. Effects] As described above, the water stopping method according to this embodiment includes a first assembly step of assembling the first and second temporary segments S1, S2 at the rear of the shield machine 100 located in the starting shaft S and in the tunnel entrance Sb, a second assembly step of advancing the shield machine 100 and assembling the first and second tunnel wall bodies W1, W2 in the tunnel entrance Sb so as to connect them to the first and second temporary segments S1, S2, and a second assembly step of assembling the first and second temporary segments S1, S2 so as to connect the packing P1 provided along the inner circumferential surface of the tunnel entrance concrete Sc to the rear end portions W of the first and second tunnel wall bodies W1, W2. 11 ,W 21 a placement step of placing a water-stopping member 200 having an 8-shape for closing the space between the first and second temporary segments S1 and S2 so as to surround the periphery of the first and second temporary segments S1 and S2; and a step of attaching the water-stopping member 200 placed around the periphery of the first and second temporary segments S1 and S2 to the packing P1 and the rear end portion W of the first and second tunnel wall bodies W1 and W2. 11 ,W 21 and the process of pushing the packing P1 into the gap between the rear end W 11 ,W 21 The water-stopping member 200 is inserted between the rear end W 11 ,W 21 and a fixing step of fixing the same to the substrate.

[0054] The first and second temporary segments S1, S2 can be removed after the fixing process, and therefore do not interfere with the construction of the structure inside the starting shaft S, unlike the sub-entrances used in conventional water-stopping methods. Moreover, unlike the integrated segments used in the conventional water stopping methods, the water stopping member 200 can be pushed into the shaft mouth Sb (using a small hydraulic jack) without installing large-scale propulsion equipment inside the shaft. Therefore, according to the water-stopping method of this embodiment, in a shield construction method such as the H&V method that uses a shield machine 100 with a special front-view shape, water can be reliably stopped at the mine entrance Sb even if the width of the starting shaft S is small, and the mine entrance Sb can be maintained in a water-stopped state even after the shield machine 100 moves forward or equipment protruding from the mine entrance S toward the starting shaft S is removed.

[0055] Furthermore, unlike the conventional method using a parent-child entrance, the water-stopping method of this embodiment does not connect the water-stopping member 200 to the shield machine 100, so the arrangement and shape of the water-stopping member 200 are not affected by the excavation accuracy of the shield machine 100. Furthermore, in the water-stopping method according to this embodiment, since the structure of the water-stopping member 200 is relatively simple, construction work effort and costs can be reduced compared to conventional methods using parent-child entrances or integrated segments.

[0056] <2. Second embodiment> Next, a second embodiment of the present invention will be described. In addition, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0057] [2-1. Shield Machine] First, a shield machine 100A used in a shield construction method to which a water stopping method according to the present embodiment is applied will be described. FIG. 14 is a front view showing the shield machine 100A.

[0058] As shown in FIG. 14, the shield machine 100A according to this embodiment is made up of a single machine body. Moreover, the shield machine 100A according to this embodiment has a generally rectangular shape when viewed from the front. That is, the top surface, bottom surface, and both left and right side surfaces of the shield machine 100A are substantially flat. In addition, the four corners of the shield machine 100A are curved. In addition, in the shield machine 100A of this embodiment, the thickness T1 of the flat portions (the portions forming the upper, lower, and left and right side surfaces) of the skin plate P is greater than the thickness T2 of the curved portions (the portions forming the four corners) in order to maintain strength (for example, the outer peripheral surface of the flat portions is gently curved outward). Moreover, the shield machine 100A assembles, at its rear (in the space created by excavation), a third tunnel wall body W3 having a rectangular cylindrical shape and made up of a plurality of segments (see FIGS. 9 to 12).

[0059] As the shield machine 100A configured in this manner advances while excavating the natural ground, it assembles the third tunnel wall body W3. This third tunnel wall body W3 has the same thickness (uniform thickness) on the top, bottom, both left and right side surfaces and at the four corners, whereas the skin plate of the shield machine 100A has a thickness T1 of the flat portion that is greater than the thickness T2 of the curved portion, as described above. Therefore, the gaps between the top, bottom, both left and right side surfaces of the third tunnel wall body W3 and the wellhead are larger than the gaps between the four corners of the third tunnel wall body W3 and the wellhead. As a result, there is a higher risk of water leaking between the top, bottom and both left and right sides of the third tunnel wall W3 and the gasket P1 than between the four corners of the third tunnel wall W3 and the gasket P1.

[0060] [2-2.Water-stopping materials] Next, a water-stopping member 200A used in the water-stopping method according to the embodiment of the present invention will be described. FIG. 15 is a front view showing the water-stopping member 200A.

[0061] As shown in FIG. 15, the water blocking member 200A has a rectangular frame shape. The width and height of the waterstop member 200A according to this embodiment are approximately equal to the width and height of the shield machine 100A. Furthermore, the distance between the left and right inner side surfaces and the distance between the upper and lower inner side surfaces of the water-stopping member 200A are slightly larger (for example, to the extent that a gap of 5 mm is formed) than the width and height of the third tunnel wall body W3. Moreover, the waterproof member 200A according to this embodiment is made up of a straight portion 7 and a curved portion 8. The straight portion 7 is a member that comes into contact with the flat portions (the upper surface, the lower surface, and both the left and right side surfaces) of the third tunnel wall body W3. The curved portions 8 are members that come into contact with the curved portions (four corners) of the third tunnel wall body W3. Furthermore, in the water-stopping member 200A according to this embodiment, the straight portions 7 are thicker than the curved portions 8 by the difference between the thickness T1 of the flat portions and the thickness T2 of the curved portions of the skin plate P of the shield machine 100A.

[0062] At least some of the other specific configurations of the water-stopping member 200A of this embodiment (material, being made of multiple members, joining surfaces and joined surfaces of the member ends, chamfering of the front end of the inner surface, width in the traveling direction of the shield machine 100A, etc.) may be the same as those of the water-stopping member 200 of the first embodiment.

[0063] [2-3. Water-stopping method at the mine entrance] Next, a waterproofing method using the waterproofing member 200A will be described.

[0064] This water stopping method is for performing water stopping at a well entrance Sb provided in a side wall Sa (well entrance concrete Sc) of a starting shaft S of the shield machine 100A in the construction of a shield tunnel using the above-mentioned shield machine 100A. The waterproofing method according to this embodiment includes a first assembly step, a second assembly step, a positioning step, a pushing step, and a fixing step, like the waterproofing method according to the first embodiment (see FIGS. 8 to 12). Each process of this embodiment is carried out in the same manner as each process of the first embodiment described above, except that the only tunnel wall inside the tunnel entrance Sb is the third tunnel wall W3, the third tunnel wall W3 is rectangular cylindrical, and the front view shape of the water-stopping member 200A is rectangular frame-like.

[0065] (After water is stopped) After the water-stopping member 200A is fixed, the gap between the packing P1 of the well entrance Sb and the third tunnel wall body W3 is blocked by the water-stopping member 200A and the filler material M. At this time, the packing P1 presses down on the flat portions (upper surface, lower surface, and both left and right side surfaces) of the third tunnel wall W3 with a force roughly equivalent to that applied to the curved portions (four corners). After that, when the shield machine 100A advances and the rear end of the shield machine 100A separates from the second packing P2, the groundwater seeping out from the natural ground fills the area around the third tunnel wall body W3. However, the area between the packing P1 at the entrance Sb and the third tunnel wall body W3 is blocked by the packing P1, the water-stopping member 200A, and the filler material M, and the packing P1 presses evenly against the entire circumference of the third tunnel wall body W3, so the groundwater does not overflow into the starting shaft S.

[0066] [2-4. Effects] The water stopping method according to the present embodiment described above is for stopping water from entering the entrance Sb provided on the side wall of the departure shaft S, and includes a first assembly process of assembling a third temporary segment S3 at the rear of the shield machine 100 located in the entrance Sb within the departure shaft S, a second assembly process of moving the shield machine 100 forward and assembling a third tunnel wall body W3 consisting of a plurality of segments in the entrance Sb so as to connect it to the third temporary segment S3, and a third assembly process of assembling a packing P1 provided along the inner peripheral surface of the entrance Sb and the rear end W of the third tunnel wall body W3 in the third temporary segment S3. 31 A process of arranging a waterproofing member 200A having a rectangular frame shape that closes the space between the third temporary segment S3 and the packing P1 and the rear end W so as to surround the periphery of the third temporary segment S3, and 31and the process of pushing the packing P1 into the gap between the rear end W 31 The water-stopping member 200A is inserted between the rear end W 31 and a fixing step of fixing the same to the substrate.

[0067] Therefore, according to the water stopping method of this embodiment, like the water stopping method of the first embodiment described above, in a shield construction method using a shield machine 100A having a special front view shape, water stopping at the mine entrance Sb can be reliably performed even if the width of the starting shaft S is small, and the mine entrance Sb can be maintained in a watertight state even after the shield machine 100A moves forward or equipment protruding from the mine entrance S toward the starting shaft S is removed. [Explanation of symbols]

[0068] 100,100A Shield Machine 100a Rear 1 First unit 2. Second unit 3. Aircraft connection section P Skin Plate T1 Skin plate flat part thickness T2 Skin plate curved part thickness 200,200A Water-stopping material 4 First annular section 4a Inner surface 4b Outer surface 41 Arc-shaped members 41a Joint surface 41b Surface to be joined 5 Second annular section 5a Inner surface 5b Outer surface 51 Arc-shaped members 51a Joint surface 51b Surface to be joined 6. Component connection 61 First member 61a,61b Joining surface, joining surface 61c aperture 62 Second member 62a Joint surface 62b Surface to be joined 62c aperture 63 Volts 7 Straight section 8 Curved section G. Ground M filler metal S Starting shaft Sa side wall Sb wellhead P1 packing P2 second packing S1 First Temporary Segment S2 Second temporary segment W1 First Tunnel Wall W 11 Rear end W2 Second Tunnel Wall W 21 Rear end W3 Third Tunnel Wall W 31 Rear end d1 Distance from rear end of packing to second packing d2 Distance from rear end of packing to front end of packing w Width of the water-stopping material in the direction of the shield machine movement

Claims

1. A method for water-stopping a tunnel entrance provided on a side wall of a starting shaft of a shield machine, comprising: A first assembly process of assembling temporary segments in the starting shaft at a rear part of the shield machine located in the shaft entrance; a second assembly process in which the shield machine is advanced and a tunnel wall body consisting of a plurality of segments is assembled in the tunnel entrance so as to be connected to the temporary segments; a placement process for placing a water-stopping member having a shape for closing a space formed between a packing provided along the inner circumferential surface of the tunnel entrance and the rear end of the tunnel wall on the temporary segment so as to surround the temporary segment; a pushing process of pushing the water-stopping member disposed around the temporary segment between the packing and the rear end portion; a fixing step of fixing the water-stopping member, which is pressed between the packing and the rear end portion, to the rear end portion; A method for watertightness at a wellhead, comprising:

2. The water-stopping method for a mine entrance as described in claim 1, characterized in that the water-stopping member used has a width in the direction of travel of the shield machine that does not exceed the distance from the rear end of the gasket to a second gasket provided on the inner surface of the mine entrance on the ground side of the gasket.

3. The shield machine includes: The first aircraft is circular when viewed from the front, A second airframe having a circular shape when viewed from the front, arranged in a direction perpendicular to the traveling direction of the first airframe; a fuselage connection portion for connecting the first fuselage and the second fuselage, As the water-stopping member, a first annular portion surrounding a first tunnel wall assembled at the rear of the first fuselage; a second annular portion surrounding a second tunnel wall assembled at the rear of the second fuselage; A water-stopping method for a mine entrance as described in claim 1 or claim 2, characterized in that a member connecting portion is used that connects the first annular portion and the second annular portion while blocking the space between the first annular portion and the second annular portion.

4. At least one of the first annular portion and the second annular portion is made of a plurality of arc-shaped members as the water-stopping member, The water-stopping method for a mine entrance as described in claim 3, characterized in that in the placement process, at least one of the first annular portion and the second annular portion is placed around the corresponding temporary segment by connecting multiple arc-shaped members together.

5. As one of the arc-shaped members, a member having a joint surface at an end portion thereof, which is located between the inner peripheral surface and the outer peripheral surface of the corresponding annular portion and faces the center of the annular portion, is used, As the other arc-shaped member to be joined to the one arc-shaped member, a member having a joined surface at an end portion thereof, the joined surface being located between the inner peripheral surface and the outer peripheral surface of the annular portion and facing the joining surface is used, The water-stopping method for a wellhead as described in claim 4, characterized in that in the positioning process, the joining surface and the joined surface are brought into contact with each other, and one of the arc-shaped members is lap-welded to the other arc-shaped member.

6. As the water-stopping member, The member connection portion can be divided into a first member located on a first direction side perpendicular to the direction in which the first body and the second body are arranged and the shield machine traveling direction, and a second member located on the opposite side to the first direction, A method for watertightly closing a wellhead as described in any one of claims 3 to 5, characterized in that the first member and the second member are capable of being joined with a bolt.

Images