JP2000265453A - Civil engineering sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a civil engineering sheet excellent in retentivity of earth and sand by laminating filament nonwoven fabric at least on one surface of base cloth having rupture ductility not more than a specific value. SOLUTION: Water permeable nonwoven fabric 2 is laminated at least on one surface of base cloth 3, and is united by needle punching to make a civil engineering sheet 1. The water permeable nonwoven fabric 2 is composed of filament having a function resistible to a movement of earth and sand, that is, pull-out resistance. Rupture ductility of the base cloth 3 is set not more than 20%, desirably, not more than 10% when measured on the basis of JIS L-1096. Standing hair 4 is formed on both surfaces of the water permeable nonwoven fabric 2 to establish a stable fixation of earth and sand. Such constitution can provide a civil engineering sheet excellent in both uneven settlement preventive performance of the weak ground, circular arc slide preventive performance of banking, retentivity of earth and sand and drainability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet for civil engineering which is excellent in prevention of uneven settlement of soft ground, prevention of arc sliding of embankment, retention of earth and sand, and excellent drainage.

[0002]

2. Description of the Related Art Conventionally, civil engineering sheets have been practically made of short fiber non-woven fabrics for increasing water permeability, or laminated with a scrim or mesh sheet as a reinforcing material.

[0003]

Although these prior arts may be able to exhibit excellent performance in drainage, they can satisfactorily prevent uneven settlement of soft ground and arc slippage of embankment. Since it was not possible to hold the earth and sand, there was a risk that the landslide would easily occur.

In view of the conventional sheet for civil engineering, the present invention is excellent in preventing uneven settlement of soft ground, preventing slippage of embankment and maintaining earth and sand, and also excellent in drainage. And provide civil engineering sheets.

[0005]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the civil engineering sheet of the present invention is a sheet formed by laminating a water-permeable nonwoven fabric on at least one surface of a base fabric, and the water-permeable nonwoven fabric is a long-fiber nonwoven fabric, and
The elongation at break of the base fabric is 20% or less as measured according to JIS L-1096.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The present invention has been made to solve the above-mentioned problems, namely,
We have studied diligently the excellent sheet for civil engineering, which is excellent in preventing uneven settlement of soft ground, preventing arc sliding of embankment, and holding earth and sand, and also excellent in drainage. When the elongation at break of the base fabric constituting the above was limited to a small area of 20% or less and a water-permeable nonwoven fabric was laminated thereon, it was surprisingly found that such a problem could be solved all at once. is there.

The fibers constituting the water-permeable nonwoven fabric of the present invention are:
It is important that it is composed of long fibers. That is,
Since the sheet for civil engineering of the present invention is used for fixing and holding the ground, having a function capable of resisting movement of the earth and sand, that is, having a pull-out resistance, establishes a stable fixing of the earth and sand. It is the rule condition for. For this reason, in the present invention, long fibers are used. In addition, it is composed of such long fibers, and the breaking elongation is 20 when measured based on JIS L-1096.
% Or less, preferably 10% or less, is a condition for reliably maintaining stable fixation of earth and sand. From another point of view, in terms of the entanglement of the nonwoven fabric and the base fabric, the pull-out strength of the base fabric from the nonwoven fabric is determined by JI
When measured based on SL-1907, it is preferably at least 3 t / m ² , more preferably 4 ± 0.5 t / m ² .
The value of m ² is good for ensuring stable fixation of earth and sand. In order to increase the resistance, the entanglement can be improved by forming the nonwoven fabric and the base fabric using a modified cross-section yarn or a mixed fineness yarn.

[0008] Further, in order to establish a stable fixation of earth and sand, it is also a preferable condition that nap or fluff is present on the surface of the water-permeable nonwoven fabric. The naps and fluffs may include loop-like ones, but in short, the naps and fluffs have a function of stopping the movement of the earth and sand, and the unit area (cm ² ) At least 10 or more, more preferably brushed, that is, 20 fluffs per unit area (cm ² )
It is better to have more than a book. From another point of view, J
Gloss (light diffuse reflectance) in a 30-degree direction by a gloss test according to IS L-1096 is preferably 5 to 70%,
More preferably about 50 ± 5% may be excellent in the function of stopping earth and sand.

[0009] The water-permeable nonwoven fabric of the present invention is JIS A-
As permeability as measured according to 1218, preferably those in the range of 1 × 10 over ^{2 ~1} × 10 ⁰ cm / sec is used. That is, the sheet for civil engineering of the present invention,
It is important to have an excellent drainage function, and this function can stably fix and hold the earth and sand on the embankment and soft ground.

The base fabric of the present invention has a function of reinforcing and assisting the low elongation and high tensile strength characteristics of such a water-permeable nonwoven fabric. Such a base fabric is 110 T / m or less, preferably 100 T / m or less. Hereinafter, more preferably no twist to 90T
/ M is used because it does not impair the physical properties and water permeability of the base fabric. The structure of the woven fabric may be any structure, but a plain weave structure is most preferably used from the viewpoint of tensile strength characteristics.

The use of a sweet twisted yarn as the woven yarn of the base fabric is a preferable configuration for achieving high strength and low elongation characteristics, but from the viewpoint of contributing to the strength of the civil engineering sheet. It is preferable to use a base fabric having a basis weight in the range of 200 to 1000 g / m ² .

As the base fabric and the water-permeable nonwoven fabric, those made of long fibers having an average fineness of 1 to 15 denier are used. Such a water-permeable nonwoven fabric has a basis weight of 10
Those having a range of 0 to 500 g / m ² are used.

The civil engineering sheet of the present invention may be a sheet in which the water-permeable nonwoven fabric is laminated on only one side of a base fabric, but preferably a sheet in which both sides are laminated. The total weight of the civil engineering sheet is preferably 400 to
1500 g / m ² , more preferably 500 to 1000
g / m ² , that is, it is possible to provide a very practical sheet which is a light sheet and has excellent performance in drainage function and earth and sand fixing function.

On the other hand, when the nonwoven fabric and the base fabric are both civil engineering sheets made of the same material, such as polyester, there is an advantage that the material can be recycled because the materials are the same. .

The sheet for civil engineering of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an example of a cross section of the civil engineering sheet of the present invention. This civil engineering sheet 1 is obtained by laminating a water-permeable nonwoven fabric 2 on both sides of a base fabric 3 and needle-punching them. If necessary, after such coalescence, a nap treatment or a nap treatment can be performed to form nap (fuzz) 4 on both sides of the water-permeable nonwoven fabric. FIG. 2 is a schematic diagram showing an example in which a plurality of the civil engineering sheets of FIG.

[0016]

The present invention will be described in more detail with reference to the following examples. The evaluation of the pull-out resistance in the examples was performed according to the following method. <Testing method of pull-out resistance> After peeling off the nonwoven fabric and the base fabric from one end of the laminated sheet sample having a width of 5 cm to 8 cm, the peeled base fabric was cut, and only the two nonwoven fabrics of the remaining peeled portion were overlapped. Hold it to the chuck. Further, after the nonwoven fabric and the base fabric up to 8 cm from the other end of the sample are peeled off, the nonwoven fabric is cut, and only the base fabric that appears after the peeling is held by the chuck. Then, the pull-out resistance was measured by a tensile tester. Example 1 1500 denier polyester filament, 6 twisted yarns
Using a 0 T / m yarn, a woven fabric having a basis weight of 310 g / m ² , woven at a spacing of 13 yarns / inch each on the front and back sides, a 200-g / m ² basis weight of 5 denier polyester filament and a thickness of 2 mm A nonwoven fabric was stacked and subjected to needle punching penetrating both layers to obtain an integrated civil engineering sheet. Needle punching conditions were as follows: needle density 30 needles / cm ² , needle depth 13
mm. As the needle type, a smooth type FPD1-36SM was used in order to minimize damage to the woven fabric yarn which bears the strength. Table 1 shows the results of a tensile test of this civil engineering sheet based on JIS L1096. Example 2 In the case where the clay sheet is laid in the middle of the soil as a drainage / reinforcing material for the embankment, the civil engineering sheet obtained in Example 1 is more closely adhered to the clay sheet. Was put on a buffing machine equipped with a sandpaper No. 80 on a rotating roll to raise the surface. Table 1 shows the characteristics of the obtained civil engineering sheet. As for the tensile strength and elongation properties, almost the same property results as in Example 1 were obtained. In addition, when the number of fluffs on the surface of the raised civil engineering sheet was measured, it was 10
The number of 0 / cm ² or more was confirmed.

[0017]

[Table 1]

[0018]

According to the present invention, it is possible to provide an excellent sheet for civil engineering excellent in preventing uneven settlement of soft ground, preventing slippage of an embankment, retaining earth and sand, and draining.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a cross section of a sheet for civil engineering of the present invention.

FIG. 2 is a schematic view showing an example of a cross section when the civil engineering sheet of the present invention is laid on an embankment.

[Explanation of symbols]

 1: Civil engineering sheet 2: permeable nonwoven fabric 3: base cloth 4: fluff 5: embankment

Front page of the continued F-term (reference) 2D043 DA03 DD01 2D044 CA05 4F100 AJ08B AJ08C AJ08D AK41 BA02 BA03 BA06 BA10B BA10C DG04B DG04C DG07A DG11A DG15B DG15C DG16B DG16C EC092 GB07 JA13A JA13B JA13C JD05A JD05B JD05C JK02B JK02C JK08A JK16 JN21B JN21C YY00A YY00B YY00C 4L032 AB01 AB04 AC02 DA02 EA00 EA06 4L047 AA21 AB03 AB07 BA03 CA05 CA08 CA19 CB01 CB10 CC10

Claims (15)

[Claims] 1. A sheet formed by laminating a water-permeable nonwoven fabric on at least one surface of a base fabric, wherein the water-permeable nonwoven fabric is a long-fiber nonwoven fabric, and the base fabric has a breaking elongation of JIS.
Civil engineering sheet characterized by being 20% or less when measured based on L-1096. 2. The sheet for civil engineering according to claim 1, wherein the elongation at break of the base fabric is 10% or less. 3. The sheet for civil engineering according to claim 1, wherein the water-permeable nonwoven fabric is laminated on both sides of a base fabric. 4. The sheet for civil engineering according to claim 1, wherein said water-permeable nonwoven fabric has nap or fluff on its surface. 5. The nap or the fluff is present in at least 10 or more per unit area (cm ² ).
Civil engineering sheet as described. 6. The sheet for civil engineering according to claim 1, wherein the water-permeable nonwoven fabric has a raised surface. 7. The permeable non-woven fabric according to JIS L-1096.
Glossiness in 30 degree direction by glossiness test according to
The sheet for civil engineering according to any one of claims 1 to 6, which has a surface that is 70%. 8. The sheet for civil engineering according to claim 1, wherein the pull-out strength of the water-permeable nonwoven fabric from the base fabric is at least 3 t / m ^{2 as} measured according to JIS L-1907. . 9. The permeable nonwoven fabric according to JIS A-1218.
Permeability when measured in accordance with the 1 × 10 over ² to 1 × 1
The civil engineering sheet according to any one of claims 1 to 8, which is in a range of ⁰ cm / sec. 10. The sheet for civil engineering according to any one of claims 1 to 9, wherein the base fabric is formed of a sweet twist yarn of 110 T / m or less. 11. The base fabric has a water permeability of 1 × 10 ^-3 to 1 as measured according to JIS A-1218.
2. The composition according to claim 1, wherein the density is in the range of ^10-2 cm / sec.
0. The sheet for civil engineering according to any one of 0. 12. The water-permeable nonwoven fabric is made of fibers having an average fineness of 1 to 15 denier.
3. The sheet for civil engineering according to any one of 1. 13. The water-permeable nonwoven fabric has a basis weight of 100 to 500.
civil engineering sheet according to any one of claims 1 to 12 in a range of g / m ^2. 14. The base fabric has a basis weight of 200 to 1000 g / m.
The civil engineering sheet according to any one of claims 1 to 13, which is in the range of ² . 15. The sheet for civil engineering according to claim 1, wherein said nonwoven fabric and said base fabric are made of the same material.