JP6147083B2 - Shield tunnel reinforcement structure and reinforcement method - Google Patents

Description

  The present invention relates to a structure and a method for reinforcing a shield tunnel lining against aged deterioration of a shield tunnel and a change in load from the outer periphery.

  Conventionally, in an existing shield tunnel assembled with segments, when it is assumed that a large external force is applied to the casing due to the influence of proximity work or the like, reinforcement for suppressing the cross-sectional deformation of the shield tunnel has been performed. As a reinforcing method, as shown in FIG. 7, a method of reinforcing concrete by placing concrete as a third lining 9 inside an existing shield tunnel provided with a primary lining 7 and a secondary lining 8 (third lining reinforcement) As described in Non-Patent Document 1, a method of reinforcing a steel material such as an H-shaped steel in the cross-sectional direction (steel material reinforcement), as described in Non-Patent Document 2, bending according to the curvature of the shield tunnel For example, a method of reinforcing and reinforcing steel sheets that have been subjected to arching with bolts one by one (steel sheet reinforcement) is employed.

“Protecting the aorta“ communication path ”in the IT era”, [online], NTT Infranet Corporation, 5 other companies, [Search January 21, 2013], Internet <URL: http: //www.civilnet .or.jp / secretaries / general / gijutsu / 2005 / s1 / files / frame.htm> “Tunnel reinforcement method using thin steel plates”, [online], Kumagai Gumi, [Searched on January 21, 2013], Internet <URL: http://www.kumagaigumi.co.jp/tech/tech_s/doboku/d_rw_2 .html>

  Conventionally, in shield tunnel reinforcement with a relatively small cross-section such as a communication road, most of the cross-sectional space is used for reinforcement work, and a space for maintaining communication cables etc. can be substantially secured. There wasn't. For example, most of the shield tunnel cross-section space was used for reinforcement work when forming a frame support in the above-described tertiary lining reinforcement or during the reinforcement period in steel reinforcement.

  An object of the present invention made in view of such circumstances is to provide a shield tunnel reinforcing structure and a reinforcing method capable of suppressing the deformation of the tunnel while suppressing the reduction of the inner space area in the cross section of the shield tunnel.

In order to solve the above problems, the shield tunnel reinforcement structure according to the present invention is:
The shield tunnel includes a primary lining and a secondary lining provided on the inner surface side of the primary lining. One or more plane seating surface portions that make a part of the inner surface of the secondary lining of the shield tunnel substantially planar;
One or more flat plate reinforcing members fixed to contact with at least one of the plane seat surface portions by a plurality of fixing members ,
The fixing member includes an anchor bolt and a nut,
The anchor bolt is driven from the neutral axis of the primary lining to the radially outer side through the flat plate reinforcing member, the planar seating surface portion and the secondary lining,
The engagement between the anchor bolt and the nut, and the flat plate reinforcing member and the planar seat surface portion Ru fixed.

Moreover, the reinforcing method of the shield tunnel according to the present invention is as follows.
The shield tunnel includes a primary lining and a secondary lining provided on the inner surface side of the primary lining. One or more flat plates on at least one of the plane seat surface portions by a plurality of fixing members with respect to one or more plane seat surface portions in which a part of the inner surface of the secondary lining of the shield tunnel is substantially flat. A method for reinforcing a shield tunnel that abuts and fixes a reinforcing member ,
The fixing member includes an anchor bolt and a nut,
The anchor bolt is driven from the neutral axis of the primary lining to the radially outer side through the flat plate reinforcing member, the planar seating surface portion and the secondary lining,
By fastening the anchor bolt and the nut, the flat plate reinforcing member and the flat seat surface portion are fixed .

  According to the reinforcing structure and the reinforcing method of the shield tunnel according to the present invention, it is possible to suppress the deformation of the shield tunnel while suppressing the reduction of the inner space area in the cross section of the shield tunnel.

It is a figure which shows the reinforcement structure of the shield tunnel which concerns on Embodiment 1 of this invention. It is explanatory drawing of the tensile stress which generate | occur | produces in a shield tunnel cross section by external force. It is the front view and principal part sectional drawing of the flat plate reinforcement member which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the fixing member and flat plate reinforcement member which concern on Embodiment 2 of this invention. It is explanatory drawing of the detail which concerns on the structure of FIG. It is a flowchart figure which shows the reinforcement method of the shield tunnel which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the conventional tertiary lining reinforcement.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram showing a reinforcing structure of a shield tunnel according to the first embodiment. The reinforcing structure according to the present embodiment includes a flat seating surface portion 1, a fixing member 2, and a flat plate reinforcing member 6 on the inner side of an existing shield tunnel including a primary lining 7 (made of steel) and a secondary lining 8 (concrete). With. In the following description, the shield tunnel cross section is described as being substantially circular, but the present invention is not limited to this.

  The flat bearing surface portion 1 is formed by placing concrete on the inner side of the shield tunnel so as to fill a section with a string of a certain length in a sectional view of the shield tunnel, and extends in the shield tunnel axial direction. Further, the flat bearing surface portion 1 is provided in at least one of the locations where the tensile stress of the inner peripheral cross section of the shield tunnel is generated by the deformation of the shield tunnel due to external force. In places where tensile stress is generated, cracks and the like may occur in the lining due to the tensile stress. Therefore, the flat plate reinforcing member 6 described later is subjected to tensile stress to suppress the occurrence of cracks and the like.

  Here, with reference to FIG. 2, the location where the tensile stress of the inner peripheral section of the shield tunnel is generated will be described. FIG. 2 is an explanatory view of the tensile stress generated in the inner circumferential cross section of the shield tunnel due to a change in external force such as loading / unloading. As shown in FIG. 2a, when the external force applied to the loading point 71 increases (when loaded), the places where tensile stress is generated are the loading point 71 on the outer periphery of the shield tunnel and the center of the shield tunnel in the sectional view of the shield tunnel. A straight line passing through the point is a point 81a where the inner circumference of the shield tunnel intersects. On the other hand, as shown in FIG. 2b, when the external force applied to the loading point 71 decreases (when the load is unloaded), the places where tensile stress is generated are the loading point 71 on the outer periphery of the shield tunnel and the shield in the shield tunnel cross-sectional view. A straight line passing through the tunnel center point and a straight line perpendicular to the shield tunnel center point are points 81b where the shield tunnel inner circumference intersects. In FIG. 2, the loading point 71 is illustrated at the top of the shield tunnel, but the loading point 71 may be assumed at an arbitrary position on the outer periphery of the shield tunnel. Moreover, the arrow of FIG. 2 shows the direction of the generated tensile stress.

  In FIG. 1, as shown in FIG. 2 a, the external force is increased and the loading point 71 is assumed on the top of the shield tunnel (or the external force is decreased and the loading point 71 is placed on either side of the shield tunnel. An assumed state) is shown, and the flat seating surface portions 1 are provided opposite to each other on the upper and lower sides of the tunnel inner space where tensile stress is generated. In addition, for example, when concrete is previously placed so that the upper side of the inside of the tunnel is made flat for the purpose of installing an electric lamp in the tunnel, the existing concrete may be used as the flat bearing surface portion 1. Is possible.

  Returning to the description of FIG. The fixing member 2 includes an anchor bolt 3, a washer 4, and a nut 5. The fixing member 2 fixes the flat bearing surface portion 1 and the flat plate reinforcing member 6 in contact with each other by the fastening force of the nut 5. The anchor bolts 3 are substantially on the plane of the flat bearing surface portion 1 and are respectively displaced in opposite directions when the shield tunnel receives an external force, that is, to locations where tensile stress can be transmitted to the flat plate reinforcing member 6. At least one is placed. For example, in FIG. 1, four anchor bolts 3 are driven in the vicinity of the left and right ends of the flat bearing surface portion 1. The anchor bolts 3 that are driven in the center of the left and right sides of the flat seat surface portion 1 are used for temporary fastening when the flat plate reinforcing member 6 is fixed to the flat seat surface portion 1. Preferably, the anchor bolt 3 is embedded up to the compression region radially outside the neutral axis of the primary lining 7 in order to prevent the tunnel bolt from coming off due to minute deformation.

  The flat plate reinforcing member 6 is a flat plate-shaped steel material that is fixed in contact with the substantially flat surface of the flat seat portion 1 by the fixing member 2. Further, the flat plate reinforcing member 6 is substantially rectangular and has a plurality of anchor bolt insertion holes 61 into which the anchor bolts 3 are inserted in the center of the long side and in the vicinity of both ends. When loaded on the top of the tunnel, a tensile stress in the left-right direction is generated at the center of the width of the flat bearing surface portion 1 in the inner peripheral cross section of the tunnel. At this time, the flat plate reinforcing member 6 suppresses the deformation of the entire tunnel by receiving the generated tensile stress via the anchor bolts 3 located near both ends of the long side. In addition, the flat plate reinforcement member 6 is provided about at least one plane seat surface portion 1 when there are a plurality of plane seat surface portions 1.

  As described above, according to the first embodiment, the planar bearing surface portion 1 is provided only at one or more locations where tensile stress is generated in the tunnel inner circumferential cross section, thereby suppressing the reduction of the inner space area in the tunnel cross section. However, deformation of the shield tunnel can be suppressed. Further, since the flat plate reinforcing member 6 that bears the tensile stress is fixed in contact with the flat seating surface portion 1 through a flat surface, the lining is compared with a conventional steel plate reinforcing structure that requires high-precision bending to the steel plate. And the reinforcing steel plate can be integrated easily and reliably. Furthermore, since it suffices to reinforce a part of the inner side of the tunnel, it is possible to reinforce while using the tunnel, and it is possible to reduce costs and shorten the construction period compared to the conventional reinforcing structure.

(Embodiment 2)
Next, the reinforcing structure of the shield tunnel according to the second embodiment of the present invention will be described. In general, the hole diameter of the anchor bolt insertion hole 61 and the hole diameter of the washer 4 of the flat plate reinforcing member 6 into which the anchor bolt 3 is inserted are larger than the diameter of the anchor bolt 3. For this reason, it is considered that the adhesion in the direction of the tensile stress between the anchor bolt 3 and the flat plate reinforcing member 6 is not maintained, and the minute deformation of the shield tunnel cannot be suppressed.

  In the present embodiment, the effect of suppressing deformation of the shield tunnel is improved by improving the adhesion in the direction of the tensile stress between the anchor bolt 3 and the flat plate reinforcing member 6. Compared to the first embodiment, the washer 4 and the flat plate reinforcing member 6 have tapered shapes 41 and 62, respectively.

  FIG. 3 is a front view (FIG. 3 a) and a sectional view (FIG. 3 b) of a main part of the flat plate reinforcing member 6 according to the present embodiment. The flat plate reinforcing member 6 has a tapered shape 62 that calls the washer 4 into a plurality of anchor bolt insertion holes 61 into which the anchor bolts 3 are inserted.

  With reference to FIG.4 and FIG.5, the reinforcement structure which concerns on this embodiment is demonstrated. FIG. 4 is a view showing the structure of the fixing member 2 (anchor bolt 3, washer 4, nut 5) and the flat plate reinforcing member 6 according to this embodiment. The washer 4 has a tapered shape 41 corresponding to the tapered shape 62 of the flat plate reinforcing member 6. Due to the fastening force of the nut 5, the anchor bolt 3 and the flat plate reinforcing member 6 are brought into close contact with each other via the washer 4 in the direction of the tensile stress.

  FIG. 5 is an explanatory diagram of details relating to the structure of FIG. 4, and shows a large diameter of the anchor bolt insertion hole 61. FIG. 5 shows a state before the fastening with the nut 5 after the washer 4 is attached to the anchor bolt 3. FIG. 5 shows two anchor bolts 3 placed on a substantially flat surface of the flat bearing surface portion 1 at a position where a tensile stress can be transmitted to the flat plate reinforcing member 6. The arrows in the figure indicate the direction of tensile stress. In order to suppress minute deformation of the shield tunnel, it is desirable that the anchor bolt 3 is in close contact with the flat plate reinforcing member 6 via the washer 4 in the direction of the tensile stress (left and right outer direction in FIG. 5).

  When the anchor bolt 3 is actually placed, it is assumed that the anchor bolt 3 is eccentric with respect to the anchor bolt insertion hole 61 of the flat plate reinforcing member 6. Specifically, the anchor bolt 3 is displaced with respect to the anchor bolt insertion hole 61 due to a position shift at the time of drilling the anchor bolt insertion hole 61 with respect to the flat plate reinforcing member 6 or a position shift at the time of placing the anchor bolt 3. Eccentric. With reference to FIGS. 5a and 5b, the relationship between the eccentricity of the anchor bolt 3 and the washer 4 will be described.

  FIG. 5 a shows a state in which the two anchor bolts 3 are eccentric in advance in the direction of tensile stress with respect to the anchor bolt insertion holes 61 of the flat plate reinforcing member 6. At this time, the washer 4a is in contact with the anchor bolt 3 and the flat plate reinforcing member 6 in the direction of the tensile stress. On the other hand, the washer 4a is not in contact with either the anchor bolt 3 or the flat plate reinforcing member 6 in the direction opposite to the direction of the tensile stress.

  When the nut 5 is attached and fastened, the washer 4a is pressed against the anchor bolt 3 and the flat plate reinforcing member 6 in the direction of tensile stress. Therefore, the anchor bolt 3 is in close contact with the flat plate reinforcing member 6 in the direction of tensile stress through the washer 4a.

  FIG. 5 b shows a state in which the two anchor bolts 3 are eccentric in advance in the direction opposite to the direction of the tensile stress with respect to the anchor bolt insertion hole 61 of the flat plate reinforcing member 6. Here, the washer 4b is a hole moved in accordance with the eccentric amount of the anchor bolt 3.

  By using the washer 4b, even when the two anchor bolts 3 are eccentric in the direction opposite to the direction of the tensile stress, the same effect as in the case of FIG. 5a described above can be obtained. That is, when the nut 5 is attached and fastened, the washer 4b is pressed against the anchor bolt 3 and the flat plate reinforcing member 6 in the direction of tensile stress. Accordingly, the anchor bolt 3 is in close contact with the flat plate reinforcing member 6 in the direction of tensile stress via the washer 4b.

  In this way, by using the washer 4 having the tapered shape 41, even if the anchor bolt 3 is eccentric with respect to the anchor bolt insertion hole 61, the anchor bolt 3 is connected to the flat plate reinforcing member 6 and the direction of tensile stress. It can adhere to.

  FIG. 6 is a flowchart showing a shield tunnel reinforcement method according to this embodiment. First, the flat seating surface portion 1 (concrete) is placed on the inner space side of the existing shield tunnel including the primary lining 7 and the secondary lining 8 and where tensile stress is generated on the inner circumferential section of the shield tunnel (step S100). ). The location where the tensile stress is generated is determined by estimating the external force applied to the shield tunnel based on the surrounding ground and construction conditions. For example, when ground reinforcement work is performed directly above the shield tunnel buried underground, it is estimated that the external force increases at the loading point on the top of the shield tunnel. It is conceivable that the flat bearing surface portions 1 are placed opposite to each other. In addition, when concrete is previously cast so that a part of the sky side in the tunnel is flat, it is also possible to use the existing concrete as the flat seat portion 1.

  Subsequently, an anchor bolt driving hole is drilled in the flat bearing surface portion 1 using a drill (step S101). Since there is a possibility of cracking in concrete due to vibration during drilling, a small-diameter core boring hole is preferably used. Moreover, you may drill a hole using the jig | tool for cutting a hole perpendicular | vertical to the plane seat part 1. FIG. In addition, the displacement between the anchor bolt placement hole drilled in the flat seat surface portion 1 and the anchor bolt insertion hole 61 of the flat plate reinforcing member 6 is investigated, and when it is difficult to insert the anchor bolt 3, the anchor bolt insertion hole 61 is cut. It may be adjusted by polishing.

  Subsequently, the anchor bolt 3 is driven through the anchor bolt insertion hole 61 of the flat plate reinforcing member 6 (step S102). Generally, an all-in anchor is used, but a chemical anchor may be preferably used because cracks may occur in concrete due to vibration caused by impact.

  Subsequently, the eccentric state of the anchor bolt 3 with respect to the anchor bolt insertion hole 61 of the flat plate reinforcing member 6 is investigated (step S103). When the anchor bolt position is eccentric, the contact area between the taper shape 41 of the washer 4 and the taper shape 62 of the flat plate reinforcing member 6 is small and the transmission of tensile stress is insufficient, or the taper shape 41 in the direction of the tensile stress. , 62 are not in close contact with each other. Preferably, a washer 4b corresponding to the eccentric amount of the eccentric anchor bolt 3 may be manufactured. Specifically, the washer 4b in which the position of the hole of the washer 4 is moved according to the amount of eccentricity may be manufactured.

  Subsequently, the flat plate reinforcing member 6 is temporarily fixed, and gypsum capping is performed to improve the adhesion between the flat seat surface portion 1 and the flat plate reinforcing member 6 (step S104). At this time, when gypsum leaks from the gap between the anchor bolt 3 and the flat plate reinforcing member 6 or from the periphery of the flat plate reinforcing member 6, a sealing operation may be performed in advance using water-stopping clay or the like.

  Subsequently, the washer 4 is attached to each anchor bolt 3 (step S105). Preferably, a washer 4b corresponding to the eccentric amount of each anchor bolt 3 manufactured based on the investigation in step S103 is attached. Further, when the seating surface is inclined, correction may be further performed using a tapered washer.

  Subsequently, the flat plate reinforcing member 6 is fastened by the nut 5 (step S106). Preferably, the nut 5 may be tightened by performing torque management, or may be a double nut to prevent loosening.

  As described above, according to the second embodiment, when the flat plate reinforcing member 6 is fastened and fixed by the nut 5, the tensile stress between the anchor bolt 3 and the flat plate reinforcing member 6 through the washer 4 having the tapered shape 41. Adhesion in the direction is improved. For this reason, it is possible to apply a tensile stress to the flat plate reinforcing member 6 even with a minute deformation occurring in the shield tunnel, and the effect of suppressing the shield tunnel deformation can be improved.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention.

  For example, the material of each component related to the shield tunnel and the reinforcing structure is not limited to the description in the present specification, and is a design matter that can be appropriately selected by those skilled in the art.

  The flat plate reinforcing member 6 may have another shape such as a substantially rectangular shape having a long side in the shield tunnel axial direction.

DESCRIPTION OF SYMBOLS 1 Flat seat surface part 2 Fixing member 3 Anchor bolt 4 Washer 5 Nut 6 Flat plate reinforcement member 7 Primary lining 8 Secondary lining 9 Tertiary lining 41 Taper shape 61 Anchor bolt insertion hole 62 Taper shape 71 Loading point 81 Tensile stress is generated Where to do

Claims (8)

A shield tunnel reinforcement structure comprising a primary lining and a secondary lining provided on the inner surface side of the primary lining ,
One or more extending in the axial direction of the shield tunnel so as to fill a section with a string of a certain length in a cross-sectional view of the shield tunnel, and making a part of the inner surface of the secondary lining of the shield tunnel substantially flat A plane bearing surface portion of
One or more flat plate reinforcing members that are fixed in contact with at least one of the planar bearing surface portions by a plurality of fixing members;
Equipped with a,
The fixing member includes an anchor bolt and a nut,
The anchor bolt is driven from the neutral axis of the primary lining to the radially outer side through the flat plate reinforcing member, the planar seating surface portion and the secondary lining,
Reinforcing structures the anchor bolt and by engaging with the nut, and the flat plate reinforcing member and the planar seat surface portion Ru fixed.   The reinforcing structure according to claim 1, wherein the flat seat surface portion is provided in at least one of locations where tensile stress is generated on the inner peripheral cross section of the shield tunnel. The fixing member further comprises a washer,
The flat plate reinforcing member has a tapered shape that calls the washer into a plurality of anchor bolt insertion holes into which the anchor bolts are inserted,
The washer has a tapered shape corresponding to the tapered shape of the flat plate reinforcing member at the outer peripheral lower portion;
The reinforcing structure according to claim 1 or 2, wherein the flat plate reinforcing member and the plurality of anchor bolts are fixed in close contact via the washer. Wherein the washer, in response to said amount of eccentricity of the anchor bolt relative to the anchor bolt insertion holes of the flat plate reinforcing member include washers made eccentric positions of the holes, the reinforcing structure according to claim 3. The shield tunnel includes a primary lining and a secondary lining provided on the inner surface side of the primary lining. One or more flat plates on at least one of the plane seat surface portions by a plurality of fixing members with respect to one or more plane seat surface portions in which a part of the inner surface of the secondary lining of the shield tunnel is substantially flat. A method for reinforcing a shield tunnel that abuts and fixes a reinforcing member ,
The fixing member includes an anchor bolt and a nut,
The anchor bolt is driven from the neutral axis of the primary lining to the radially outer side through the flat plate reinforcing member, the planar seating surface portion and the secondary lining,
A method for reinforcing a shield tunnel, wherein the flat plate reinforcing member and the flat seat surface portion are fixed by fastening the anchor bolt and the nut .   The reinforcing method according to claim 5, wherein the flat seat surface portion is provided in at least one of locations where tensile stress is generated on the inner peripheral cross section of the shield tunnel. The fixing member further comprises a washer,
The flat plate reinforcing member has a tapered shape that calls the washer into a plurality of anchor bolt insertion holes into which the anchor bolts are inserted,
The washer has a tapered shape corresponding to the tapered shape of the flat plate reinforcing member at the outer peripheral lower portion;
The reinforcing method according to claim 5 or 6, wherein the flat plate reinforcing member and the plurality of anchor bolts are fixed in close contact via the washer. Wherein the washer, in accordance with the eccentricity of the anchor bolt relative to the anchor bolt insertion holes of the flat plate reinforcing member includes a position washers is eccentric holes, method of reinforcing a part recited in claim 7.

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