Tunnel lining joint sheet structure and its construction method

Abstract

To provide a tunnel lining joint sheet structure capable of being easily constructed while suppressing separation from the joint surface of the preceding lining concrete, twisting and / or wrinkling, and a construction method.SOLUTION: A tunnel lining joint sheet structure 6 is formed on a joint 4c of lining concrete 4a, 4b which is constructed at the inner side of a waterproof sheet 5 of a tunnel 1. The tunnel lining joint sheet structure 6 includes: a splice surface sheet 10 which has adhesive permeability to allow permeation of the adhesive 20a before curing; and an adhesive layer 20 made of the adhesive 20a. After covering the splice surface sheet 10 on the joint surface 4e of the preceding lining concrete 4a, the adhesive 20a is applied to the surface 10a of the splice surface sheet 10 facing the subsequent lining concrete 4b.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sheet structure provided at a joint in a tunnel lining concrete and a construction method for installing the sheet structure at the joint, and in particular to a tunnel lining joint sheet structure that separates adjacent lining concrete pieces across the joint and a construction method for the same. [Background technology]

[0002] The joints of tunnel lining concrete are prone to cracking, lifting, and spalling. As a countermeasure, it is recommended to cover the edge (joint surface) of the previously poured lining concrete with a vinyl sheet and secure it with adhesive tape, and then pour the subsequent lining concrete (see Non-Patent Document 1). This separates the previous lining concrete from the subsequent lining concrete, preventing cracking, lifting, and spalling of each concrete. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Ministry of Land, Infrastructure, Transport and Tourism, Tohoku Regional Development Bureau, "Guidelines for Quality Assurance of Concrete Structures (Draft) (Tunnel Lining Concrete Edition)", May 2016, pp. 52-53 Summary of the Invention [Problem to be solved by the invention]

[0004] When vinyl sheets are placed over the joints of the preliminary lining concrete, they tend to come off from the joints and become easily distorted and wrinkled. In view of the above circumstances, the present invention aims to provide a tunnel lining joint sheet structure and its construction method that does not come loose from the joint surface of the advance lining concrete, is less likely to become twisted or wrinkled, and is easy to construct. [Means for solving the problem]

[0005] In order to solve the above problems, the present invention provides a tunnel lining concrete joint structure provided at the joint of the lining concrete constructed on the inner surface of the tunnel waterproof sheet, A joint surface sheet covering the joint surface of the preliminary lining concrete; An adhesive layer made of an adhesive that bonds the joint surface sheet and the joint surface; The joint surface sheet has adhesive permeability that allows the adhesive to pass through before hardening. According to this characteristic configuration, by adhering the joint surface sheet to the joint surface with an adhesive layer, the joint surface sheet can be prevented from coming loose from the joint surface and from becoming distorted or wrinkled. Because the joint surface sheet is adhesive permeable, applying adhesive to the surface of the joint surface sheet facing the subsequent lining allows the adhesive to penetrate the joint surface sheet and bond the joint surface of the preceding lining concrete to the joint surface sheet. At this stage, the subsequent lining side is an open space, making it easy to apply the adhesive. There is no need to flip over the joint surface sheet to apply adhesive to the surface of the joint surface sheet facing the subsequent lining, making the application process even easier. By interposing a joint surface sheet between the preceding lining concrete and the succeeding lining concrete, the lining concretes are separated, preventing cracking, lifting, peeling, etc. near the joints of each lining concrete.

[0006] The joint face sheet is preferably made of a nonwoven fabric. This ensures that the joint surface sheet is adhesive permeable and that the adhesive penetrates the joint surface sheet.

[0007] The adhesive is preferably at least one selected from the group consisting of epoxy adhesives and acrylic adhesives, which allows the adhesive to reliably penetrate the joint surface sheet.

[0008] The method of the present invention is a construction method for a tunnel lining construction joint sheet structure provided at a joint of lining concrete constructed on the inner surface of a tunnel waterproof sheet, A joint surface sheet having adhesive permeability that allows penetration of the adhesive before hardening is placed over the joint surface of the preliminary lining concrete, Thereafter, adhesive is applied to the surface of the joint surface sheet facing the subsequent lining concrete. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a tunnel lining joint sheet structure and construction method that does not come loose from the joint surface of the advance lining concrete, is less likely to become twisted or wrinkled, and is easy to construct. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a front cross-sectional view of a tunnel in which a tunnel lining construction joint sheet structure according to a first embodiment of the present invention is installed on the construction joint surface of a preliminary lining concrete. [Figure 2] FIG. 2 is a side cross-sectional view of the tunnel taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional side view of the tunnel after the subsequent lining concrete has been poured. [Figure 4] FIG. 4 is a front view showing a tunnel lining construction joint sheet structure according to a second embodiment of the present invention in a state before construction. [Figure 5] FIG. 5 is a front cross-sectional view taken along line VV in FIG. 6, showing a tunnel in a state where the tunnel lining construction joint sheet structure according to the second embodiment is installed on the construction joint surface of the preliminary lining concrete. [Figure 6]FIG. 6 is a side cross-sectional view showing the tunnel according to the second embodiment, taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a front cross-sectional view of a tunnel in which a tunnel lining construction joint sheet structure according to the third embodiment of the present invention is installed on the construction joint surface of the preliminary lining concrete. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. <First embodiment (FIGS. 1 to 3)> Figures 1 and 2 show a mountain tunnel 1 being constructed using the NATM method. The tunnel 1 includes a primary lining 3 and a secondary lining 4. Shotcrete 3a of the primary lining 3 is sprayed onto the excavation surface 2a of the natural ground 2. A waterproof sheet 5 is laid on the tunnel inner surface of the shotcrete 3a. The waterproof sheet 5 contains an ethylene vinyl acetate (EVA) resin sheet as its main element. The secondary lining 4 is provided on the tunnel inner surface side of the waterproof sheet 5.

[0012] As shown in Figures 2 and 3, the secondary lining 4 is constructed in the axial direction of the tunnel, span by span, in accordance with the excavation of the tunnel 1. A tunnel lining joint sheet structure 6 is installed at the joint 4c between the lining concrete 4a, 4b, etc. for each span.

[0013] As shown in Figures 1 and 2, the tunnel lining joint sheet structure 6 comprises a plurality of joint surface sheets 10 and an adhesive layer 20. The joint surface sheets 10 are preferably made of nonwoven fabric. The nonwoven fabric is preferably a spunbonded nonwoven fabric made of polyester long fibers, but is not limited to polyester and may be polyethylene or other polyolefins. It is not limited to long fibers and may be short fibers. It is not limited to spunbonded nonwoven fabric and may be a needle-punched nonwoven fabric. Preferably, the thickness of the joint surface sheet 10 made of nonwoven fabric is about 0.1 mm to 1 mm, and the basis weight is 10 g / m 2 ~100g / m 2 That's about it.

[0014] As shown in Figure 1, each joint surface sheet 10 has a roughly trapezoidal rectangular shape. As shown in Figures 1 and 2, the joint surface sheet 10 is placed over the joint surface 4e of the lining concrete 4a (hereinafter referred to as "prior lining concrete 4a") that has been poured first, on the side of the subsequent lining concrete 4b (subsequent lining side). The edge 10h of the long side of the trapezoidal joint surface sheet 10 is aligned with the outer periphery (upper edge in Figure 2) of the arched joint surface 4e, and is in close proximity to or in contact with the waterproof sheet 5. The edge 10g of the short side of the joint surface sheet 10 is aligned with the inner periphery (lower edge in Figure 2) of the joint surface 4e, and extends further inside the tunnel (lower side in Figure 2) than the inner periphery of the joint surface 4e. The height dimension H of the joint surface sheet 10 10 (The distance between the edges 10g and 10h) is the difference between the inner and outer radii of the joint surface 4e, Δr 4e Greater than (H 10 >Δr 4e ).

[0015] As shown in Fig. 1, a plurality of joint face sheets 10 are arranged in the circumferential direction of the arch on the joint face 4e. Opposing edges of adjacent joint face sheets 10 in the circumferential direction of the arch may overlap each other, or may be fitted together without overlapping.

[0016] As shown in Fig. 2, the joint surface sheet 10 is adhered to the joint surface 4e by an adhesive layer 20. The adhesive 20a constituting the adhesive layer 20 is preferably an epoxy adhesive, but is not limited to this and may be an acrylic adhesive. The adhesive 20a before hardening can permeate the joint surface sheet 10 made of nonwoven fabric in the thickness direction. In other words, the joint surface sheet 10 has adhesive permeability that allows the adhesive 20a before hardening to pass through.

[0017] The adhesive layer 20 includes a front layer portion 21, a sheet penetration portion 22, and a back permeable layer portion 23. The front layer portion 21 is coated on the front surface 10a of the joint surface sheet 10 facing the subsequent lining concrete 4b. The sheet penetration portion 22 penetrates into the joint surface sheet 10 made of nonwoven fabric and fills the spaces between the nonwoven fabric fibers that make up the joint surface sheet 10. The back permeable layer portion 23 is interposed between the back surface 10b of the joint surface sheet 10 and the joint surface 4e. The back permeable layer portion 23 bonds the joint surface sheet 10 and the preceding lining concrete 4a. As shown by the hatched pattern in FIG. 1, the adhesive layer 20 is applied to the entire area of ​​the joint face sheet 10, but it may also be applied to only a part of the joint face sheet 10, such as the edge thereof.

[0018] <Construction method for tunnel lining joint sheet structure> The tunnel lining joint sheet structure 6 is constructed as follows. As shown in Figures 1 and 2, after the formwork (not shown) used for pouring and curing the advance lining concrete 4a is removed and moved, a pouring joint surface sheet 10 is placed over the pouring joint surface 4e of the advance lining concrete 4a.

[0019] An adhesive 20a is applied to the front surface 10a of the joint surface sheet 10, which faces the subsequent lining. Preferably, the adhesive 20a is applied while the joint surface sheet 10 is stretched. At this stage, the area where the subsequent lining concrete 4b will be placed is an open space (Fig. 2), making it easy to apply the adhesive 20a. Moreover, there is no need to turn over the joint surface sheet 10 and apply the adhesive 20a directly to the back surface 10b, making the application process even easier.

[0020] Before hardening, the adhesive 20a seeps into the inside of the joint surface sheet 10, and then penetrates through the joint surface sheet 10 to get between the joint surface 4e and the joint surface sheet 10. This causes the joint surface sheet 10 to be bonded to the joint surface 10 of the advance lining concrete 4a via the adhesive 20a. The adhesive 20a hardens to form an adhesive layer 20.

[0021] A plurality of joint surface sheets 10 are arranged in the circumferential direction of the arch of the joint surface 4e. Preferably, the adhesive 20a is applied while the joint surface sheets 10 are arranged in order from the top of the arch to both the left and right sides. In this way, the tunnel lining joint sheet structure 6 is installed over the entire joint surface 4e of the advance lining concrete 4a. Since each joint surface sheet 10 of the tunnel lining joint sheet structure 6 is adhered to the joint surface 4e, the joint surface sheet 10 does not come off the joint surface 4e. Furthermore, by stretching the joint surface sheet 10 when applying the adhesive 20a, the joint surface sheet 10 can be prevented from becoming twisted or wrinkled.

[0022] Thereafter, as shown in FIG. 3, the subsequent lining concrete 4b is poured. As a result, the tunnel lining construction joint sheet structure 6 is sandwiched between the lining concrete 4a, 4b and embedded in the secondary lining 4. The tunnel inner portion 10d of the construction joint surface sheet 10 has a dimensional difference (H 10 >Δr 4e ) from the secondary lining 4 toward the tunnel inner surface (the lower side in FIG. 3). The protruding portion 10d is cut and removed. In the adhesive application step, it is not necessary to apply the adhesive 20a to the protruding portion 10d.

[0023] In the NATM tunnel 1 constructed in this way, the joint surface sheet 10 is interposed at the joint 4c between the lining concrete 4a, 4b, separating the lining concrete 4a, 4b. This prevents cracking, lifting, peeling, etc. in the areas near the joint 4c of the lining concrete 4a, 4b.

[0024] Next, another embodiment of the present invention will be described. In the following embodiment, the same components as those already described will be denoted by the same reference numerals in the drawings and the description thereof will be omitted. <Second embodiment (FIGS. 4 to 6)> As shown in FIG. 4, the tunnel lining joint sheet structure 6B according to the second embodiment includes a joint surface sheet 10B, a welding sheet 11, and a connecting sheet 12. Before construction, the joint surface sheet 10B is in the shape of a long strip. The length of the joint surface sheet 10B is substantially equal to the perimeter of the arch portion of the tunnel 1 and, in turn, the perimeter of the joint surface 4e of the preliminary lining concrete 4a. As in the first embodiment, the joint surface sheet 10B is preferably made of nonwoven fabric and has adhesive permeability that allows the adhesive 20a to pass through before it hardens.

[0025] As shown in Fig. 4, a welding sheet 11 is attached to the joint surface sheet 10B. The welding sheet 11 is formed in a long strip shape extending along the edge 10h of the joint surface sheet 10B on the outer periphery of the tunnel. The welding sheet 11 is made of a material that can be welded to the waterproof sheet 5, preferably made of the same waterproof material as the waterproof sheet 5, and more preferably made of EVA resin.

[0026] The joint surface sheet 10B and the welding sheet 11 are joined by a connecting sheet 12 that straddles both the joint surface sheet 10B and the welding sheet 11. The connecting sheet 12 is formed in a long strip shape that spans the entire longitudinal length of the joint surface sheet 10B and the welding sheet 11. The connecting sheet 12 is made of, for example, nonwoven fabric, but the material of the connecting sheet 12 is not limited to nonwoven fabric and may also be a resin film such as polyethylene. The connecting sheet 12 is joined to the joint surface sheet 10B and the welding sheet 11 with an adhesive 15.

[0027] A fold line 12c is formed in the center of the width direction of the connecting sheet 12. The fold line 12c extends in the longitudinal direction of the connecting sheet 12 and follows the edge 10h of the joint surface sheet 10B on the tunnel outer periphery side. The connecting sheet 12 can be folded at the fold line 12c. The edge 10h of the joint surface sheet 10B on the tunnel outer periphery side is joined to the portion 12a on one side of the fold line 12c of the connecting sheet 12 via adhesive 15a, and the edge of the welding sheet 11 on the preceding lining side is joined to the portion 12b on the other side via adhesive 15b. The welding sheet 11 can be folded along the fold line 12c relative to the joint surface sheet 10B, and can therefore be folded along the edge 10h of the joint surface sheet 10B on the tunnel outer periphery side.

[0028] As shown in Figure 6, in the tunnel lining joint sheet structure 6B after construction, the connecting sheet 12 is folded at a right angle at the folding line 12c, and the welding sheet 11 is oriented horizontally so as to form a right angle with the joint surface sheet 10B. The welding sheet 11 is aligned along the surface of the waterproof sheet 5 facing the inner surface of the tunnel (the lower side in Figure 6), and is welded to the waterproof sheet 5.

[0029] As shown in Fig. 6, the joint surface sheet 10B hangs down vertically from the welding sheet 11 and is aligned with the joint surface 4e. The joint surface sheet 10B and the welding sheet 11 are perpendicular to each other, so that the cross section of the tunnel lining joint sheet structure 6B is L-shaped. The joint surface sheet 10B is joined to the joint surface 4e via the permeable adhesive layer 20, as in the first embodiment (Fig. 2).

[0030] As shown by the two-dot chain lines in Figure 4 and Figure 5, multiple slits 13 are formed in the construction joint surface sheet 10B after installation. Each slit 13 extends from the tunnel inner periphery edge 10g of the construction joint surface sheet 10B toward the tunnel outer periphery edge 10h. The slits 13 reach or extend close to the tunnel outer periphery edge 10h. Furthermore, the slits 13 also cut into the vertical portion 12a of the connecting sheet 12 that is joined to the construction joint surface sheet 10B.

[0031] As shown by the two-dot chain line in Fig. 4, a plurality of slits 13 are arranged at intervals in the longitudinal direction (circumferential direction of the arch) of the joint surface sheet 10B. As shown in Fig. 5, these slits 13 divide the joint surface sheet 10B into a plurality of joint surface sheet portions 14.

[0032] As shown in Figure 5, multiple joint surface sheet portions 14 are arranged side by side in the circumferential direction of the arch of the joint surface 4e of the preliminary lining concrete 4a. The relative angle between two adjacent joint surface sheet portions 14 via a slit 13 is adjusted to match the curvature of the arch of the joint surface 4e. The edge portions 14e, 14f on the slit 13 side of these two joint surface sheet portions 14 are overlapped. As a result, the apparent shape of each joint surface sheet portion 14 when viewed from the front is trapezoidal, with the long side facing the outer periphery of the tunnel and the short side facing the inner periphery of the tunnel.

[0033] As shown in FIG. 5, the horizontal portions 12b of the welding sheet 11 and the connecting sheet 12 extend in the circumferential direction of the arch across the plurality of joint surface sheet portions 14, connecting these joint surface sheet portions 14 together.

[0034] The tunnel lining jointed construction sheet structure 6B according to the second embodiment is constructed as follows. As shown in FIG. 4, the joint surface sheet 10B before construction has no slits 13 formed therein. As shown in FIG. 6, the joint surface sheet 10B is placed over the joint surface 4e of the preliminary lining concrete 4a, and the welding sheet 11 is folded over the joint surface sheet 10B and applied to the waterproof sheet 5. Then, the welding sheet 11 is welded and joined to the waterproof sheet 5. This allows the joint surface sheet 10B to be suspended and supported in a state where it is hung from the waterproof sheet 5, reliably preventing the joint surface sheet 10B and, in turn, the tunnel lining joint sheet structure 6 from falling. Therefore, even before the adhesive 20a is applied, the joint surface sheet 10B can be kept stably covering the joint surface 4e.

[0035] Next, as shown by the two-dot chain lines in Fig. 4 and Fig. 5, the joint surface sheet 10B is cut with scissors to form slits 13, thereby dividing the joint surface sheet 10B into a plurality of joint surface sheet portions 14. Then, the opposing edges 14e, 14f of adjacent joint surface sheet portions 14 are overlapped with each other. This prevents the joint surface sheet 10B from becoming twisted or wrinkled.

[0036] Furthermore, adhesive 20a is applied to the front surface 10a of the joint surface sheet 10B. In addition to the area where the subsequent lining concrete 4b is to be placed being an open space, the joint surface sheet 10B is suspended and supported, making it even easier to apply the adhesive 20a. The adhesive 20a penetrates into the joint surface sheet 10B, bonding the joint surface sheet 10B to the joint surface 4e. In this way, the tunnel lining joint sheet structure 6B is installed on the joint surface 4e of the advance lining concrete 4a. Thereafter, by pouring the subsequent lining concrete 4b, the joint surface sheet 10B is embedded so that it is sandwiched between the lining concretes 4a and 4b, and the welding sheet 11 and the connecting sheet 2 are embedded so that they are sandwiched between the waterproof sheet 5 and the subsequent lining concrete 4b.

[0037] <Third embodiment (FIG. 7)> As shown in FIG. 7, the tunnel lining joint sheet structure 6C according to the third embodiment includes multiple joint surface sheets 10C, a welding sheet 11, and a connecting sheet 12. As in the first embodiment (FIG. 1), multiple joint surface sheets 10C made of nonwoven fabric are arranged in the circumferential direction of the arch of the tunnel 1 and placed on the joint surface 4e. Each joint surface sheet 10C has a trapezoidal shape with its edge 10g on the inner periphery of the tunnel shorter than its edge 10h on the outer periphery of the tunnel. The edges 10h on the outer periphery of the tunnel of the multiple joint surface sheets 10C are connected to each other by a connecting sheet 12. Furthermore, the multiple joint surface sheets 10C and the welding sheet 11 are connected via the connecting sheet 12. As in the second embodiment (FIG. 6), the welding sheet 11 is welded to the waterproof sheet 5. The height dimension H of the joint surface sheet 10C (the distance between the edge on the inner periphery of the tunnel and the edge on the outer periphery of the tunnel) 10 is the difference between the inner and outer radii of the joint surface 4e Δr 4e It is adjusted to (H 10 =Δr 4e Therefore, the tunnel-inside portion of the joint surface sheet 10C does not protrude from the secondary lining 4 toward the tunnel inner surface. Therefore, after the subsequent lining concrete 4b is poured, there is no need to cut and remove the protruding portion 10d (see FIG. 3) toward the tunnel inner surface.

[0038] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention. For example, the adhesive-permeable joint surface sheet 10 is not limited to a nonwoven fabric, but may be a porous sheet having a large number of holes formed therein, or may be a foamed sheet having interconnected pores. The adhesive 20a may be any adhesive other than an epoxy adhesive or an acrylic adhesive, as long as it has permeability to the joint surface sheet 10 before hardening and exhibits the required adhesive strength. The welding sheet 11 and the connecting sheet 12 in the tunnel lining joint sheet structure 6B of the second embodiment may be omitted. In the joint surface sheet 10 of the first embodiment, as in the third embodiment, H 10 =Δr 4e It may be configured as follows. [Explanation of symbols]

[0039] 1. Tunnel 4 Secondary lining 4a Pre-lining concrete 4b Subsequent lining concrete 4c Joint 4e Joint surface 5. Tarpaulin 6 Tunnel lining joint sheet structure 6B, 6C Tunnel lining construction joint sheet structure 10. Joint surface sheet 10B, 10C Joint surface sheet 11 Welding sheet 12 Connecting Sheets 20 Adhesive layer 20a adhesive

Claims

1. A tunnel lining joint sheet structure provided at the joint of the lining concrete constructed on the inner surface of the tunnel waterproof sheet, A joint surface sheet covering the joint surface of the preliminary lining concrete; An adhesive layer made of an adhesive that bonds the joint surface sheet and the joint surface; a tunnel lining joint sheet structure comprising: the joint surface sheet having adhesive permeability that allows the penetration of the adhesive before hardening; the adhesive layer including a front layer portion, a sheet penetration portion, and a back-side permeable layer portion; the front layer portion is coated on the front side of the joint surface sheet facing the subsequent lining concrete; the sheet penetration portion soaks into the joint surface sheet; the back-side permeable layer portion is interposed between the back side of the joint surface sheet and the joint surface; and the joint surface sheet and the preceding lining concrete are bonded together by the back-side permeable layer portion.

2. The tunnel lining construction joint sheet structure according to claim 1, characterized in that the construction joint surface sheet is made of nonwoven fabric.

3. 3. A tunnel lining joint sheet structure according to claim 1, wherein the adhesive is at least one selected from the group consisting of epoxy adhesives and acrylic adhesives.

4. A construction method for a tunnel lining joint sheet structure according to any one of claims 1 to 3, The joint surface sheet having adhesive permeability that allows penetration of the adhesive before hardening is placed over the joint surface of the advance lining concrete, Then, in the open space where the uncast subsequent lining concrete is to be placed, an adhesive that will become the adhesive layer is applied to the surface of the joint surface sheet facing the subsequent lining concrete.

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