JPH01111999A - Waterproof sheet - Google Patents

Abstract

PURPOSE: To allow a waterproof sheet to resist clogging and perform a draining function over a long period by interposing between nonwoven fabrics a sheet- shaped net in which linear elements intersect and bond together forming wavy indentations. CONSTITUTION: A water-permeable sheet B comprising a sheet-shaped net 3 interposed between a first nonwoven fabric 1 and a second nonwoven fabric 2 is laminated over one side of a water-impermeable sheet A to construct this waterproof sheet. The sheet-shaped net 3 is formed with a structure in which linear elements, such as synthetic resin filaments, metallic wires covered with a synthetic resin, or uncovered metallic wires, extend in irregular directions while intersecting one another and bond together forming wavy indentations. Water springing from the natural ground side of a tunnel, together with mud contained therein, is introduced into a water conduit 4 and discharged therethrough, the water conduit 4 being formed of the nonwoven fabrics 1, 2 and the sheet-shaped net 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a waterproof sheet that can be effectively used to discharge spring water to the outside without hindrance during civil engineering works such as tunnel construction.

Traditionally, N
As seen in the ATM construction method, a waterproof sheet is interposed between the primary lining concrete and secondary lining concrete of the tunnel, and spring water from the second layer concrete side (spring water from underground into the tunnel) is Water) is used to prevent water from leaking into the secondary lining concrete side, and as shown in Figure 6, a waterproof sheet used for this purpose is a non-woven fabric on an impermeable base sheet a. It is known that a water-permeable sheet b having a buffering property of
Publication No. 295). In this waterproof sheet, a water-permeable sheet b is placed on the primary covering concrete side, and spring water from the second-layer concrete side flows down into the water-permeable sheet b. If a tunnel is used for a long period of time in a place where there is water, the earth and sand contained in the spring water will accumulate in the water-permeable sea area and block the spring water passage.
The problem is that it cannot be used permanently for a long period of time because the water permeability and waterproof performance deteriorate.

The present invention has been made to improve the above-mentioned circumstances.It is difficult to cause clogging with earth and sand, and can be used for a long period of time even when used in tunnels etc. where there is a lot of earth and sand and a large amount of spring water is generated. The purpose is to provide a waterproof sheet that effectively exhibits its functions.

B. To achieve the above object, the present invention provides a waterproof sheet in which a water-permeable sheet is laminated on one side of a water-impermeable base sheet.
The water-permeable sheet is made of a nonwoven fabric and a sheet-like mesh body having undulations and convexities in which a large number of linear bodies intersect with each other and these linear bodies adhere to each other at least in part at each intersection. To provide a waterproof sheet characterized by being interposed between the sheets.

Here, the nonwoven fabric constituting the water permeable sheet is as follows:
It is preferable to use a fiber having a fiber density of 0.03 to 0.3 g/- through which earth and sand can pass.

Further, as for the sheet-like net-like body constituting the water-permeable sheet, the thickness of the linear body is 0.5 to 311, the mesh size of the sheet-like net-like body is 0.1 to 20+-, and The sheet-like net-like body having a height of 1 to 30 mm is preferably used. Note that the mesh size in the present invention refers to the maximum distance between two adjacent linear bodies. Since two adjacent linear bodies form a plane or three-dimensional space, the distance between them is perpendicular to any point on one linear body and the tangent at that point, and between the plane containing that point and the other line. This is the straight line distance from the point where the two objects intersect.

Sho: In the waterproof sheet of the present invention, the water-permeable sheet has the sheet-like mesh body interposed between nonwoven fabrics, and thus this sheet-like mesh body constitutes the water conduit. Therefore, when the waterproof sheet of the present invention is used, for example, to guide and discharge spring water from a tunnel, the spring water from the ground side passes through the nonwoven fabric on the outside of the water-permeable sheet and flows through the water conduit formed by the sheet-like network. Even if the spring water contains a considerable amount of sediment, most of the sediment will be discharged along with the spring water through the conduit formed by the sheet-like network, and for this reason, the water will be absorbed into the water-permeable sheet. In other words, in the present invention, since the water conduit is formed of the special sheet net-like body having the above-mentioned relatively large undulating unevenness, the primary covering concrete that has passed through the outer non-woven fabric is less prone to clogging. Spring water from the side flows down through this reticulated body (!i1-like voids) and is discharged to the outside, but at this time, even if the spring water contains a large amount of sediment, the reticulated body Since it is difficult to be clogged with earth and sand and the water guide path is reliably secured, spring water is always reliably guided and discharged to the outside, and earth and sand are also discharged together with the spring water. Therefore, even when used for a long period of time, it exhibits excellent water flow performance and can be used permanently.

In addition, since the sediment from the spring is discharged through the water conduit, it is difficult for the sediment to enter the inner non-woven fabric, but even if the spring water containing sediment flows into the inner non-woven fabric, it may become clogged. Even if this happens, there is no problem because the discharge function of the spring water is ensured by the outer nonwoven fabric and the water conduit made of the sheet-like net, as described above, and the inner nonwoven fabric absorbs the ground pressure against the impermeable sheet. Effectively functions as a buffer material from protrusions.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a waterproof sheet according to an embodiment of the present invention, which has a water-permeable sheet B laminated on one side of a water-impermeable sheet A.

In the water-permeable sheet B, 1 and 2 are a first nonwoven fabric and a second nonwoven fabric, respectively, made of fiber webs, and 3 is a sheet-like mesh having undulating irregularities interposed between the first and second nonwoven fabrics 1 and 2. The hollow part of this net-like body 3 is configured as a water conduit 4. This water permeable sheet B
The first and second nonwoven fabrics 1. are coated on both sides of the net-like body 3. 2
It is formed by laminating these and integrating them by appropriate means such as an adhesive or a needle punch method.

Here, as the water-impermeable sheet A, a synthetic resin sheet such as polyvinyl chloride, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, etc. is suitable, and the thickness thereof is 0.3~6n
It is preferable to set it to +.

In addition, the first and second nonwoven fabrics 1 constituting the water permeable sheet B
．． As No. 2, a nonwoven fabric made of synthetic resin such as polyethylene, polypropylene, polyester, etc. is preferably used. In this case, the fiber density of the first and second nonwoven fabrics is not particularly limited, but it is preferably 0.03 to 0.3 that earth and sand can pass through.
It is preferable to use a material of about g/csi.

Further, the sheet-like network body 3 may be made of polyamide, polyester, polyethylene, etc., as shown in FIGS.
A large number of thin wires made of synthetic resin such as polyolefin such as polypropylene, metal wires coated with synthetic resin such as polyvinyl chloride, or wire bodies 5 such as metal wires intersect each other irregularly in the horizontal direction and the thickness direction. It extends in different directions from one side to the other, and is formed into a net-like sheet having a large number of continuous linear bodies having undulations and depressions 7 that are bonded to each other at least in part at each intersection 6,
It has shape retention and rigidity to maintain such a shape.

In this case, the thickness of the linear bodies 5 constituting the sheet-like net-like body 3 is preferably 0.5 to 3 mm, and the size of the mesh 8 of the sheet-like net-like body 3 is 0, 1. -201 mm, particularly preferably 1-10 mm. Further, it is preferable that the height h1 of the sheet-like mesh body 3, that is, the distance between the top of the highest undulation on the upper side and the top of the highest undulation on the bottom side, is 1 to 30 mm, particularly 2 to 10 mm. be.

Note that the first and second nonwoven fabrics 1.2 and the net-like body 3 may be bonded over the entire surface, but in order to improve the workability and handling of the waterproof sheet, they may be partially bonded with adhesive or the like. They may be joined and integrated.

Moreover, the thickness of the water permeable sheet B is the same as that of the first and second nonwoven fabrics 1
．． 5 to 20 in a state in which 2 and the mesh body 3 are combined and integrated.
It is preferable to set it as mm.

Furthermore, although the water-impermeable sheet A and the water-permeable sheet B may be bonded over the entire surface, in order to improve the workability and handleability of the waterproof sheet, it is preferable to partially bond them together with an adhesive or the like. May be integrated.

When the above-mentioned waterproof sheet is used to guide and discharge spring water in a tunnel, the non-woven fabric is placed facing the ground side, so that the spring water from the tunnel ground side is directed to the non-woven fabric. In this case, even if the spring water contains a considerable amount of earth and sand, the net-like body 3 forming the headrace channel 4 A large number of linear bodies intersect with each other while changing direction irregularly in the horizontal direction and the thickness direction and extend from one side to the other, and these many continuous linear bodies cross at least partially at each intersection. Since it is a sheet body with a relatively large mesh having undulating concavities and convexities bonded to each other, the soil and sand can be discharged together with spring water without clogging with soil and sand. In addition, in this case, since the mesh body 3 has good shape retention and rigidity, it will not collapse or shrink the wire even if pressure is applied by pouring the secondary lining concrete, and it will maintain good shape. Ensure water permeability.

Therefore, this waterproof sheet can exhibit excellent water permeability over a long period of time.

Figure 4 shows another embodiment of the present invention, in which a nonwoven fabric with a coarse fiber density is used as the first nonwoven fabric 1, and a nonwoven fabric with a dense fiber density is used as the second nonwoven fabric 2. . Here, the first nonwoven fabric 1 has a fiber density of 0.01 to 0.05.
g/cd, and the second nonwoven fabric 2 has a fiber density of about 0.07 to 0.15 g/-.

The other structure, method of use, and operation and effect of this embodiment are almost the same as those of the embodiment shown in Fig. 1, but the waterproof sheet of this embodiment is used to guide and discharge spring water in a tunnel. When used, the first nonwoven fabric 1 is placed facing the ground. As a result, spring water from the tunnel earth side flows into the first nonwoven fabric 1 with a coarse fiber density, and further flows through this into the water conduit 4 and is discharged, but in this case, the spring water Even if a considerable amount of mud is contained, the first nonwoven fabric 1 through which spring water flows has a coarse fiber density, so it is difficult to be clogged with mud, and most of the mud flows through the first nonwoven fabric 1. The spring water passes through and is discharged from the water conduit 4, so that a good spring water discharge effect is maintained over a long period of time, and even spring water containing a lot of mud can be reliably discharged. Further, in this case, the second nonwoven fabric 2 has a dense fiber density, and even if the spring water with mud flows into the second nonwoven fabric 2, even if the mud becomes clogged, Since the second nonwoven fabric 2 is not placed on the ground side but on the impermeable sea 1-A side, the discharge of spring water accompanied by mud is ensured by the first nonwoven fabric 1 and the water conduit 4. Therefore, the buffering function of the water-impermeable sheet A by the second nonwoven fabric 2 is effectively exhibited.

In addition, in the present invention, the water conduit may be formed by laminating a plurality of sheet-like mesh bodies. Further, various changes may be made to other configurations without departing from the gist of the present invention.

The waterproof sheet of the present invention does not easily become clogged even when placed in a place where spring water with a lot of earth and sand is discharged, exhibits good drainage function over a long period of time, and has an excellent buffer function. demonstrate. Therefore, the waterproof sheet of the present invention can be suitably used for draining spring water in tunnels with a lot of earth and sand, and
It also shows an excellent buffering effect on concrete walls mixed with steel fiber used in tunnel construction.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, FIG. 2 is an enlarged plan view of a net-like body used on the same side, FIG. 3 is an enlarged side view of the same rod-like body, and FIG. A sectional view showing another embodiment, FIG. 5 is a sectional view of a conventional waterproof sheet. A...Water-impermeable sheet, B...Water-permeable sheet, ■,
2... Non-woven fabric, 3... Sheet-like net-like body, 4... Conduit, 5... Linear body, 6... Intersection, 7... Waviness-like unevenness.

Claims (1)

[Claims] 1. In a waterproof sheet in which a water-permeable sheet is laminated on one side of a water-impermeable sheet, the water-permeable sheet has a large number of linear bodies that intersect with each other, and these linear bodies form at least a portion of each intersection. A waterproof sheet characterized in that a sheet-like net-like body having undulations and convexities bonded to each other is interposed between nonwoven fabrics.