JP7097711B2 - Tarpaulin continuum for tunnels - Google Patents

Description

The present invention relates to a waterproof sheet continuum in which a plurality of waterproof sheets serving as a waterproof layer of a tunnel are connected, and particularly to a joint structure between adjacent waterproof sheets in the waterproof sheet continuum.

As a general method for constructing a mountain tunnel, a NATM (New Austrian tunneling Method) method can be mentioned (see Patent Document 1 and the like). The construction method is carried out by the following procedure. First, the ground is excavated and a primary lining is provided on the excavated surface. A waterproof sheet, which is a waterproof layer, is attached to the inner circumference of the primary lining. After that, a secondary lining is placed.

The waterproof sheet has a laminated structure of a water-permeable sheet material such as an EVA sheet and a water-permeable sheet material such as a non-woven fabric. The permeable sheet material is directed to the primary lining. The impermeable sheet material is directed to the secondary lining. The impermeable sheet material prevents spring water from the ground from flowing into the secondary lining side. The spring water is discharged through the permeable sheet material.

The width dimension of one waterproof sheet facing the tunnel axis direction is, for example, about 2 m. In the portion of the waterproof sheet having a width of about 300 mm to 500 mm on both ends in the width direction, the impermeable sheet material and the impermeable sheet material are not joined to each other and are free-end joint sheet portions. A portion having a width of about 50 mm to 200 mm at the end of the joint sheet portion of the water permeable sheet material in two adjacent waterproof sheets is overlapped and joined to each other. Moreover, the portions having a width of about 50 mm to 200 mm at the ends of the joint sheet portions of the impermeable sheet material in the two adjacent waterproof sheets are overlapped and joined to each other. Therefore, between the two adjacent waterproof sheets, a joint portion of a joint sheet having a width of, for example, about 550 mm to 700 mm, which is made of two impermeable sheet materials, and a joint portion of which is made of two water-permeable sheet materials, which has a width of about 550 mm to 700 mm, for example. A continuous portion of the tarpaulin is formed. The continuous portion of the seam sheet of the impermeable sheet material and the continuous portion of the seam sheet of the water permeable sheet material are not joined to each other, and a gap is formed between them.

Japanese Unexamined Patent Publication No. 6-129192 Jikken Sho 63-2502 Gazette

When the waterproof sheet is stretched so as to be added along the inner surface of the primary lining, the continuous portion of the joint sheet of the impermeable sheet facing the inside of the tunnel hangs down by its own weight. After that, when the secondary lining is cast from the bottom side of the tunnel toward the top end, the hanging portion is sequentially crushed from the bottom side of the tunnel, and the air inside is pushed up. Therefore, when the secondary lining is placed near the top of the tunnel, a large air pool is formed between the continuous portion of the seam sheet of the permeable sheet and the continuous part of the seam sheet of the impermeable sheet at the top of the tunnel. .. The presence of such an air pool impairs the placement thickness of the secondary lining.
In view of such circumstances, it is an object of the present invention to suppress the formation of the air pool at the top end of the tunnel and the like, and to secure the casting thickness of the secondary lining.

In order to solve the above problems, the present invention includes a plurality of (two or more, preferably about three) waterproof sheets arranged in the width direction, and each waterproof sheet is a water-impermeable sheet material and a water-permeable sheet laminated with each other. A splicing sheet portion having a predetermined width is set on each of the impermeable sheet material and the end side in the width direction of the impermeable sheet material, including the material, and the splicing sheet portion of the impermeable sheet material of two adjacent waterproof sheets. The two waterproof sheets are connected to each other to form a continuous part of the impermeable joint sheet, and the joint parts of the water permeable sheet material of the two waterproof sheets are connected to each other to form a continuous part of the water permeable joint sheet. In the tunnel tarpaulin continuum stretched along the inner circumference of the primary lining in the axial direction of
It is characterized in that the continuous portion of the impermeable joint sheet and the continuous portion of the water permeable joint sheet are joined in a scattered spot shape, a linear shape or a planar shape.

The end portions of the joint sheet portions of the two impermeable sheet materials constituting the impermeable joint sheet continuous portion are overlapped and joined to form an impermeable joint portion.
The end portions of the joint sheet portions of the two permeable sheet materials constituting the permeable joint sheet continuous portion are overlapped and joined to form a permeable joint portion.
It is preferable that the impermeable joint portion and the water permeable joint portion are joined in a scattered point shape, a linear shape or a planar shape.
Further, the sheet portions on both outer sides of the impermeable joint sheet continuous portion sandwiching the impermeable joint portion and the sheet portions on both outer sides sandwiching the water permeable joint portion in the water permeable joint sheet continuous portion are dispersed. It is preferably joined in a dot-like, linear or planar shape.

According to the present invention, it is possible to suppress or prevent the formation of a large air pool between the permeable sheet material and the impermeable sheet material at the continuous portion of the two waterproof sheets at the top of the tunnel. Therefore, it is possible to secure the casting thickness of the secondary lining.

FIG. 1 is a cross-sectional view of a tunnel including a tarpaulin continuum according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 3 showing a tunnel after the installation of the waterproof sheet continuum and before the placement of the secondary lining. FIG. 3 is a perspective view of the waterproof layer including the waterproof sheet continuum in the tunnel. FIG. 4A is a cross-sectional view showing a state before joining the adjacent waterproof sheets of the waterproof sheet continuum. FIG. 4B is a cross-sectional view showing a state in which the impermeable sheet materials and the water permeable sheet materials of the adjacent waterproof sheets are joined to each other. FIG. 4C is a cross-sectional view of the waterproof sheet continuum. FIG. 5 is a bottom view taken along the line VV of FIG. 4 (c). FIG. 6 shows a second embodiment of the present invention and is a bottom view corresponding to FIG. FIG. 7 shows a third embodiment of the present invention and is a cross-sectional view corresponding to FIG. FIG. 8 shows a third embodiment of the present invention and is a bottom view corresponding to FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
1 to 5 show the first embodiment of the present invention. As shown in FIG. 1, the ground 2 is excavated to form the tunnel 1. The wall of the tunnel 1 has a layered structure in which the primary lining 3, the backfill material 4, the waterproof layer 5, and the secondary lining 6 are stacked in this order from the side of the inner wall 2a of the ground.

As shown in FIG. 3, the waterproof layer 5 includes a plurality of waterproof sheet continuums 10. A plurality of waterproof sheet continuums 10 are arranged and connected in the axial direction of the tunnel 1.
As shown in FIGS. 4A to 4C, each waterproof sheet continuum 10 is manufactured at a factory and includes a first waterproof sheet 11 and a second waterproof sheet 12. These waterproof sheets 11 and 12 are arranged and arranged in the width direction (left and right in FIG. 4). The width dimension of each of the waterproof sheets 11 and 12 is, for example, about 2 m, but the present invention is not limited thereto. The width direction of the waterproof sheets 11 and 12 is directed to the axial direction of the tunnel 1 (the direction orthogonal to the paper surface of FIG. 1). The longitudinal direction of the waterproof sheets 11 and 12 is along the circumferential direction of the tunnel 1.
In FIG. 4, for convenience of drawing, the number of waterproof sheets in the waterproof sheet continuum 10 is two, but it may be three or more. The waterproof sheet continuum 10 may be a series of three or more waterproof sheets connected in the width direction.

As shown in FIG. 4A, each of the waterproof sheets 11 and 12 has a laminated sheet structure of the impermeable sheet material 20 and the impermeable sheet material 30. The thicknesses of the impermeable sheet material 20 and the impermeable sheet material 30 in the figure are exaggerated with respect to the width dimension.

As shown in FIG. 2, the impermeable sheet material 20 is directed to the secondary lining 6 side (lower side in the figure), and the water permeable sheet material 30 is directed to the backfill material 4 side and thus the primary lining 3 side (same). (Upper side in the figure). The impermeable sheet material 20 has a high impermeable property and has a waterproof function of preventing spring water from the ground 2 from flowing into the tunnel 1. Examples of the material of the impermeable sheet material 20 include thermoplastic resins such as ethylene-vinyl acetate copolymer resin (EVA), polyolefin resin, and polyvinyl chloride resin. As the polyolefin resin, in addition to a completely non-polar polyolefin resin such as polyethylene (PE) and polypropylene (PP), a polar group (carboxyl group, etc.) such as acrylic acid or maleic anhydride is graft-polymerized on PE or PP. Examples thereof include a modified polypropylene resin having polarity and imparting adhesiveness. Preferably, the material of the impermeable sheet material 20 is EVA.

As shown in FIG. 2, the permeable sheet material 30 is laminated on the back surface of the impermeable sheet material 20 (the surface to face the primary lining 3 side, the upper surface in the figure). The water permeable sheet material 30 is made of a non-woven fabric or the like. Examples of the material of the non-woven fabric include chemical fibers such as polyester, polypropylene and polyethylene, natural fibers such as coconut husk, cotton, linen, wool and silk, and inorganic fibers such as glass, carbon, metal and ceramic. Preferably, the non-woven fabric material of the water permeable sheet material 30 is a chemical fiber.
A part of the backfilling material 4 is impregnated in the water permeable sheet material 30. The water permeable sheet material 30 has a function of fixing to the backfill material 4, a drainage function, a cushioning function, and the like.

As shown in FIG. 4A, the central portion 21 in the width direction of the impermeable sheet material 20 in each of the waterproof sheets 11 and 12 and the central portion 31 in the width direction of the water permeable sheet material 30 form a central joint portion 14. They are joined to each other through. The central joint portion 14 may extend over the entire area of the seat central portions 21, 31 and may be partial. In the partial case, the seat central portions 21 and 31 may be joined in a strip shape at a plurality of locations in the width direction.
The means for joining the central portions 21 and 31 of the sheets may be heat fusion or an adhesive may be used. In the case of heat fusion, hot air may be blown between the seat center portions 21 and 31 to partially melt the surface of the seat center portions 21 and 31, and the sheet center portions 21 and 31 may be crimped to join. good. As the adhesive, a hot melt resin may be used.

As shown in FIG. 4C, the impermeable sheet material 20 and the impermeable sheet material 30 at both ends of the waterproof sheet continuum 10 in the width direction are not joined and are joined with the free-end joint sheet portions 24 and 34. It has become. These free end joint sheet portions 24, 34 are used for joining to another adjacent waterproof sheet continuum 10 at the construction site of the tunnel 1.

As shown in FIG. 4A, the side ends of the waterproof sheets 11 and 12 adjacent to each other in the width direction of the impermeable sheet materials 20 and 20 are impermeable joint sheet portions 25, respectively. In other words, a joint sheet portion 25 having a predetermined width is set on the end side of each impermeable sheet material 20 in the width direction. The width dimension W ₂₅ of the joint sheet portion 25 is about W ₂₅ = 200 mm to 500 mm. The ratio of the width W ₂₅ of the joint sheet portion 25 to the total width W ₂₀ of the impermeable sheet material 20 of each of the waterproof sheets 11 and 12 is preferably about W ₂₅ / W ₂₀ = 1/10 to 1/4.

As shown in FIG. 4B, the impermeable joint sheet portions 25, 25 of two adjacent waterproof sheets 11 and 12 are connected to each other to form an impermeable joint margin sheet continuous portion 40. At the center of the continuous portion 40 of the impermeable joint sheet in the width direction, the end portions 25e and 25e of the two impermeable joint sheet portions 25 and 25 are overlapped and joined to the impermeable joint portion 42. It has become. The width dimension W ₄₂ of the impermeable joint portion 42 is preferably about W ₄₂ = 50 mm to 200 mm. The ratio of the width dimension W ₄₂ of the impermeable joint portion 42 to the width dimension W ₂₅ of the impermeable joint sheet portion 25 is preferably W ₄₂ / W ₂₅ = about 1/10 to 1/2, more preferably W ₄₂ /. W ₂₅ = about 3/10.
The means for joining the end portions 25e and 25e may be heat fusion or an adhesive may be used. In the case of heat fusion, hot air may be blown between the end portions 25e and 25e to partially melt the surfaces of the end portions 25e and 25e, and the end portions 25e and 25e may be crimped to be joined. As the adhesive, a hot melt resin may be used.

As shown in FIG. 4A, the side ends of the waterproof sheets 11 and 12 adjacent to each other in the width direction of the water-permeable sheet materials 30 and 30 are water-permeable joint sheet portions 35, respectively. In other words, a joint sheet portion 35 having a predetermined width is set on the end side of each water permeable sheet material 30 in the width direction. The width dimension W ₃₅ of the joint sheet portion 35 is about W ₃₅ = 200 mm to 500 mm. The ratio of the width W ₃₅ of the joint sheet portion 35 to the total width W ₃₀ of the water permeable sheet material 30 of each of the waterproof sheets 11 and 12 is preferably about W ₃₅ / W ₃₀ = 1/10 to 1/4.

As shown in FIG. 4B, the water-permeable joint sheet portions 35, 35 of two adjacent waterproof sheets 11 and 12 are connected to each other to form a water-permeable joint sheet continuous portion 50. At the center of the continuous portion 50 of the water-permeable joint sheet in the width direction, the end portions 35e and 35e of the two water-permeable joint sheet portions 35 and 35 are overlapped and joined to form the water-permeable joint portion 52. .. The width dimension W ₅₂ of the water permeable connecting portion 52 is preferably about W ₅₂ = 50 mm to 200 mm. The ratio of the width dimension W ₅₂ of the water permeable connecting portion 52 to the width dimension W ₃₅ of the water permeable joint sheet portion 35 is preferably about W ₅₂ / W ₃₅ = 1/10 to 1/2, more preferably W ₅₂ / W ₃₅ . = About 3/10.
The means for joining the end portions 35e and 35e may be heat fusion or an adhesive may be used. In the case of heat fusion, hot air may be blown between the end portions 35e and 35e to partially melt the surfaces of the end portions 35e and 35e, and the end portions 35e and 35e may be crimped to be joined. As the adhesive, a hot melt resin may be used.

As shown in FIG. 4 (c), the impermeable joint sheet continuous portion 40 and the water permeable joint sheet continuous portion 50 are joined to each other at a plurality of points in the width direction.
Specifically, the impermeable joint portion 42 and the water permeable joint portion 52 are joined via the continuous joint portion 15e. As shown in FIG. 5, the continuous joint portion 15e extends linearly in the longitudinal direction (upper and lower in FIG. 5) of the waterproof sheets 11 and 12.

As shown in FIG. 2, the sheet portions 41 on both outer sides of the impermeable joint sheet continuous portion 40 sandwiching the impermeable joint portion 42 and the water permeable joint portions 52 of the water permeable joint sheet continuous portion 50 on both outer sides. The sheet portion 51 is joined via the side joining portion 15a. As shown in FIG. 5, the lateral joint portion 15a extends linearly in the longitudinal direction (upper and lower in FIG. 5) of the waterproof sheets 11 and 12. The side joint portions 15a are not limited to one location in the width direction of the sheet portions 41 and 51, and may be provided at a plurality of locations.

The joining means for forming the continuous sheet joining portions 15e and 15a may be fusing or an adhesive may be used. In the case of heat fusion, hot air is blown between the joint sheet continuous portions 40 and 50 to partially melt the surface of the joint sheet continuous portions 40 and 50, and the joint sheet continuous portions 40 and 50 are crimped. It may be joined together. As the adhesive, a hot melt resin may be used.

As shown in FIG. 2, the portions other than the joint portions 15a and 15e between the continuous portions 40 and 50 of the joint sheet have a gap of 10 g. The gap of 10 g is narrow.

A plurality of the above-mentioned waterproof sheet continuums 10 are manufactured at the factory and carried into the construction site of the tunnel 1.
At the construction site, while excavating the ground 2, spray concrete is sprayed on the inner wall 2a of the ground to construct the primary lining 3. A lock bolt (not shown) is placed on the ground 2.
After the excavation of the ground 2 and the construction of the primary lining 3 have progressed by a predetermined distance, a semi-cylindrical backfill formwork (not shown) is installed along the inner peripheral wall of the primary lining 3. A waterproof sheet continuum 10 is stretched on the outer peripheral surface of the backfilling form. The impermeable sheet material 20 of the waterproof sheet continuum 10 is applied to the outer peripheral surface of the backfilling formwork, and the water permeable sheet material 30 is directed to the primary lining 3.
One free end joint sheet portion 24, 34 of the waterproof sheet continuum 10 is heat-sealed or adhered to the opposite free end joint sheet portion 24, 34 of the waterproof sheet continuum 10 installed immediately before. Join with an agent or the like. The joint structure of the joint sheet portions 24, 34 may be the same as the joint structure of the joint sheet portions 25, 35 in each waterproof sheet continuum 10.

Next, the backfilling material 4 such as mortar is filled in the gap between the waterproof sheet continuum 10 and the primary lining 3. The backfilling material 4 is continuous with the backfilling material 4 of the excavation span immediately before. A part of the backfill material 4 is impregnated into the water permeable sheet material 30.
After filling the backfill material 4, the backfill form is removed or transferred to the front of the excavation.
Since the impermeable joint sheet continuous portion 40 of the waterproof sheet continuous body 10 is joined to the water permeable joint sheet continuous portion 50 via the joint portions 15e and 15a, the amount of sagging due to its own weight or the like can be reduced.

After that, a formwork for secondary lining (not shown) is installed, and the secondary lining 6 is placed from the bottom side of the tunnel toward the top end. At this time, the gap 10 g between the joint sheet continuous portions 40 and 50 of the waterproof sheet continuous body 10 is sequentially crushed from the tunnel bottom side. On the other hand, the gap 10g itself is narrowed in advance. Therefore, even if the gap 10g on the bottom side of the tunnel is crushed and the air there rises along the gap 10g, the amount of air that collects in the gap 10g at the top of the tunnel is small because the original amount of air in the gap 10g is small. Can be reduced. Therefore, it is possible to prevent the continuous portion 40 of the impermeable joint sheet at the top of the tunnel from swelling significantly.
As a result, it is possible to sufficiently secure the casting thickness of the secondary lining 6 at the top of the tunnel.
In this way, the tunnel 1 is constructed.

Next, another embodiment of the present invention will be described. In the following embodiments, the same reference numerals are given to the drawings for configurations that overlap with the above-described embodiments, and the description thereof will be omitted.
<Second Embodiment>
FIG. 6 shows a second embodiment of the present invention. In the second embodiment, the joint portions 15e and 15a of the impermeable joint sheet continuous portion 40 and the water permeable joint sheet continuous portion 50 are scattered along the longitudinal direction (upper and lower in FIG. 6) of the waterproof sheets 11 and 12. It is arranged in a shape. In FIG. 6, the joint portions 15e and 15a are arranged in a single row, but the joint portions 15e and 15a may be arranged in a plurality of rows or may be randomly arranged.
According to the second embodiment, even if the area of each of the joint portions 15e and 15a is small, the gap 10 g between the continuous portions 40 and 50 of the joint sheet can be reduced, and the permeable water-impermeable joint sheet continuous portion 40 can be efficiently hung down. Can be prevented.

<Third Embodiment>
7 and 8 show a third embodiment of the present invention. In the third embodiment, the joint portions 15e and 15a of the water-permeable joint sheet continuous portion 40 and the water-permeable joint sheet continuous portion 50 are widely spread between the joint sheet continuous portions 40 and 50 and have a planar shape. .. The lateral joint 15a is separated from the central joint 14. The side joint portion 15a may be attached to the central joint portion 14.
According to the third embodiment, the gap 10 g between the continuous portions 40 and 50 of the joint sheet can be further reduced.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, by superimposing and joining almost all of the two impermeable joint sheet portions 25, 25 constituting the impermeable joint sheet continuous portion 40, almost the entire impermeable joint sheet continuous portion 40 is formed. It may be an impermeable connecting portion 42.
Almost all of the two water-permeable joint sheet portions 35, 35 in the water-permeable joint sheet continuous portion 50 are overlapped and joined to each other, so that almost the entire water-permeable joint sheet continuous portion 50 becomes the water-permeable joint portion 52. You may.
The work of manufacturing the waterproof sheet continuum 10 including the work of joining the joint sheet portions 25 and 35 is not limited to the factory, and may be performed at the construction site of the tunnel 1.
The waterproof layer 5 may be directly stretched on the inner surface of the primary lining 3 without the backfilling material 4.
The waterproof sheet continuum 10 can be applied to a tunnel construction method other than the NATM method.

The present invention can be applied to, for example, tunnel construction by the NATM method.

1 Tunnel 5 Waterproof layer 6 Secondary lining 10 Waterproof sheet continuum 10g Gap 11,12 Waterproof sheet 20 Impermeable sheet material 25 Impermeable joint sheet part (joint sheet part of impermeable sheet material)
25e End part 30 Water permeable sheet material 35 Water permeable joint sheet part (joint sheet part of water permeable sheet material)
35e End part 40 Impermeable joint sheet continuous part 41 Both outer sheet parts 42 Impermeable joint part 50 Water permeable joint sheet continuous part 51 Both outer sheet parts 52 Water permeable joint part

Claims (3)

A plurality of waterproof sheets arranged in the width direction are provided, and each waterproof sheet includes a water-permeable sheet material laminated with each other and a water-permeable sheet material having a drainage function, and the water-permeable sheet material and the water-permeable sheet material in the width direction. A joint sheet portion having a predetermined width is set on each end side, and the joint sheet portions of the impermeable sheet material of two adjacent waterproof sheets are connected to each other to form a continuous portion of the impermeable joint sheet, and the above 2 The joint sheets of the water-permeable sheet material of the two waterproof sheets are connected to each other to form a continuous part of the water-permeable joint sheet, and the width direction is directed toward the axis of the tunnel and is stretched along the inner circumference of the primary lining. In a series of waterproof sheets for tunnels
The continuous portion of the impermeable joint sheet and the continuous portion of the impermeable joint sheet are joined to each other in a scattered, linear or planar shape, so that the continuous portion of the impermeable joint sheet is formed by the impermeable joint sheet. A tarpaulin continuum characterized by supporting the continuous part against its own weight . The end portions of the joint sheet portions of the two impermeable sheet materials constituting the impermeable joint sheet continuous portion are overlapped and joined to form an impermeable joint portion.
The end portions of the joint sheet portions of the two permeable sheet materials constituting the permeable joint sheet continuous portion are overlapped and joined to form a permeable joint portion.
The impermeable joint portion and the water permeable joint portion are joined in a scattered point-like, linear or planar shape, and are joined to each other between the impermeable joint sheet continuous portion and the water permeable joint sheet continuous portion. The waterproof sheet continuum according to claim 1, wherein a gap is formed on both sides of the impermeable joint portion and the water permeable joint portion . The sheet portions on both outer sides of the water-permeable joint sheet continuous portion sandwiching the impermeable joint portion and the sheet portions on both outer sides of the water-permeable joint sheet continuous portion sandwiching the water-permeable joint portion are scattered. The waterproof sheet continuum according to claim 2, wherein the waterproof sheet continuum is joined in a linear or planar shape.

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