JPH07229134A - Civil engineering sheet - Google Patents

Abstract

PURPOSE:To make a civil engineering sheet fit for use in laying underground by providing a pile yarn on a foundation cloth, and specifying the tensile strength of the foundation cloth, the total denier of the pile yarn and the pile length. CONSTITUTION:A pile yarn is planted on a foundation cloth by taffeting or the like, and at need the back of the foundation cloth is backed by synthetic resin to keep the pile yarn from falling off. The foundation cloth has tensile strength of 2ton/m or more at least in one direction to prevent breaking in the ground. The pile yarn is total denier of 50 denier or more to prevent the pile yarn from being laid completely parallel to the foundation cloth by earth pressure. Further the pile length of the pile yarn is 3cm or less to prevent the pile yarn from being laid completely parallel to the foundation cloth by pressure of earth or the like. Thus, in the case of laying the sheet under the ground, it is possible to satisfy the strength, water discharge effect and shock absorbability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a civil engineering sheet which is buried and laid in the soil for civil engineering work such as ground improvement and ground reinforcement.

[0002]

2. Description of the Related Art Conventionally, a cloth made by weaving and weaving synthetic fibers as a civil engineering sheet to be laid and laid in the soil at the time of civil engineering work such as ground improvement and ground reinforcement, and this cloth are made of vinyl chloride. The one coated with resin is used.
In particular, in the case of embankment work, the sheets are required to have drainage action and shock absorption in addition to being strong. A spunbonded nonwoven fabric is generally known as a sheet having a so-called drainage effect that absorbs moisture in the soil and discharges it to the outside. At present, other net-like sheets are used together. In addition, molded products made of vinyl chloride resin, etc. have been used recently, but they are costly and have low strength like spunbonded non-woven fabrics. At this stage, they must satisfy all requirements of strength, drainage effect and shock absorption. Was impossible.

[0003]

The present invention solves such a problem, and is suitable for being used by being buried in the soil and used, and the civil engineering which satisfies all of the strength, drainage effect and shock absorption property. The purpose is to provide a sheet for use.

[0004]

In order to solve this problem, the present invention is a civil engineering sheet comprising a base cloth and a pile yarn provided on the base cloth, wherein the base cloth has at least one direction. The gist is that the tensile strength is 2 ton / m or more. The pile yarn has a total denier of 50.
The gist is that it is 0 denier or more. Further, the gist is that the pile length of the pile yarn is 3 cm or less. Further, the gist is that the pile yarn is planted on the base cloth by tufting. Further, the gist is that the back surface of the base cloth provided with the pile yarn is backed.

The present invention will be described in detail below. The base fabric used in the present invention has a tensile strength of 2 ton / m in at least one direction.
When the tensile strength is less than 2 ton / m, the sheet is vulnerable to pressure, resistance, and tensile strength applied to the sheet in the soil, so that the sheet may be cut or broken.

The fiber material forming the base cloth refers to spun yarns of synthetic fibers such as polyamide, polyester, polyaramid, acrylic, polyethylene, polypropylene and vinylon, long fiber yarns including multifilaments and monofilaments, and the like. Any of melting point fused yarn, spun yarn, flame-retardant yarn, spun-flame retardant yarn and crimped yarn may be used, or these may be used in combination.

The base fabric may be a woven fabric to which a plain weave, a twill weave, a satin weave or the like is applied, or a knitted fabric to which weft knitting or warp knitting is applied. Further, it may be a mesh sheet shape made of a base fabric woven and knitted by these techniques and having a width capable of fixing the pile yarn. When the base cloth is in the form of a mesh sheet, the upper and lower soils sandwiching the sheet are connected by the mesh portion, so that the pulling out strength of the sheet can be improved from the meshing effect of the soil. The mesh sheet as used herein is preferably one having a cloth filling rate of 95% or less. The filling rate is a numerical value calculated by the following formula by taking a plane photograph of the cloth, measuring the weight (M) of the plane photograph and the weight (N) remaining after cutting out the space portion of the plane photograph.

Filling ratio (%) = (N / M) × 100 As a method for providing pile yarns on the base cloth, it is preferable to use a tufting machine from the viewpoint of productivity.

The pile yarn used in the present invention is required to have a total denier of 500 denier or more, and if it is less than 500 denier, the pile yarn may lie completely parallel to the base fabric due to the pressure of soil or the like. There is a nature.
Although the pile yarn may lie down at a certain angle due to the pressure of soil or the like, the thickness of the pile yarn portion needs to cause a drainage action, and therefore, the thickness that can maintain the drainage capacity must be maintained. In addition, the pile length of the pile yarn must be 3 cm or less, and if the pile yarn exceeds 3 cm, the same phenomenon as that of the pile yarn becomes thin, and the problem of sleeping completely parallel to the base fabric due to the pressure of soil etc. There is. The pile yarn density is not limited so that it can be used in various fields, but usually 16 to 20 yarns / inch in the warp direction,
8-10 pieces / inch in the weft direction.

The material of the pile yarn is polyamide, polyester, polyaramid, acrylic, similar to the base cloth material.
This refers to spun yarns of synthetic fibers such as polyethylene, polypropylene and vinylon, long fiber yarns including multifilaments and monofilaments, low melting point fusion yarns, spun yarns,
Any of a flame-retardant yarn, a spun-dyed flame-retardant yarn and a crimped yarn may be used, or these may be used in combination.

The civil engineering sheet obtained by the present invention is backed with a synthetic resin such as vinyl chloride resin or synthetic rubber so that the pile thread portion for promoting the drainage action does not come off in order to cope with various sites. The pile may be looped or cut.
However, considering the pressure applied to the pile yarn portion, the loop shape is preferable.

[0012]

As described above, the base fabric has a tensile strength of 2 ton / m or more in at least one direction, and the pile yarn has a total denier of 500 denier or more and a pile length of 3 cm or less, It is possible to provide a civil engineering sheet that is suitable for being embedded and laid in soil and that satisfies all of the strength, drainage effect, and shock absorption.

[0013]

EXAMPLES The present invention will now be described with reference to examples. The performance of the civil engineering sheets in the examples was evaluated by the following method. (1) Tensile strength (ton / m); JIS L-1096
Was measured in accordance with the above and converted into a width of 1 m. (2) Cutting elongation (%); measured according to JIS L-1096. (3) Water permeability: Pull a sheet on the bottom of a frame of 1 m x 1 m and put 5 kg of sand shown below from the top, and put 5% of water content in the soil tank, dry density 1.46 t / m ³ (compacting degree 90 The sand was tightened with a large rammer so that the water content was 5%, and 5 liters of water was added uniformly from the top of the sand, and the situation where water came out from the bottom was observed.

Sand used in the test Specific gravity Gs; 2.745 50% particle size D ₅₀ ; 0.26 Uniformity coefficient Uc; 2.0

Example 1 Four polyesters of 1000d / 192f were S70 times /
23 × 23 with regular twisted weave (2 mats)
Weaving with books / inch to obtain a base fabric, and using 1800d / 96f BCF nylon yarn as the pile yarn on the base fabric, 1
/ 8 gauge, pile length 0.8 cm, 34 stitches / 1
Tufting was performed at 0 cm to obtain a civil engineering sheet of Example 1.

EXAMPLE 2 Polyester 1200d / 500f 8 ply twisted yarn was used as ground warp, polyester 1200d / 500f 4 ply twisted yarn was used as entangled yarn, and weft was polyester 1500d
/ 378f 3 ply-twisted yarn, 3 part woven structure with density of 3.8 / both in length and 10cm,
In addition, the weft is the above-mentioned leno weave polyester 150
3d twisted yarn of 0d / 378f, polyester 1500
A d / 378f three-ply yarn is used as the ground warp and the warp density is 20.
A 5 cm plain weave part was made with a book / inch, and weaving was performed so that the leno weave part and the plain weave part were alternately arranged. This base cloth is impregnated with urethane resin using a padder, and the plain weave portion 5 cm has a central portion 4 cm wide and a pile yarn of 1800 d /
Tufting was performed using a 96f BCF nylon thread with a 1/8 gauge, a pile length of 0.8 cm, and 34 stitch / 10 cm to obtain a civil engineering sheet of Example 2.

Comparative Example 1 Four polyesters of 1000d / 192f were S70 times /
23 × 23 with regular twisted weave (2 mats)
Weaving with a book / inch was performed to obtain a sheet of Comparative Example 1.

Table 1 shows the evaluation results of the obtained civil engineering sheets of Examples 1 and 2 and Comparative Example 1.

[0019]

[Table 1]

As is clear from Table 1, the civil engineering sheets of Examples 1 and 2 according to the present invention have sufficient strength suitable for the construction method of being buried in the soil and also have a drainage effect. I understand.

[0021]

As described above, according to the present invention, the base fabric has a tensile strength of 2 ton / m or more in at least one direction,
The pile yarn has a total denier of 500 denier or more and a pile length of 3 cm or less, which makes it suitable for being buried and laid in the soil, and has all the strength, drainage effect, and shock absorption properties. It is possible to provide a satisfactory civil engineering sheet. Further, the pile yarn is tufted on the base fabric, and then the back face of the base fabric on which the pile yarn is provided is backed to prevent the pile yarn from coming off from the base fabric.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshifumi Moriguchi, 23 Uji Kozakura, Uji City, Kyoto Prefecture Central Research Institute, Unitika Co., Ltd. Company Nara office

Claims (5)

[Claims] 1. A civil engineering sheet comprising a base fabric and a pile thread provided on the base fabric, wherein the base fabric has a tensile strength of 2 ton / m or more in at least one direction. Sheet. 2. The civil engineering sheet according to claim 1, wherein the pile yarn has a total denier of 500 denier or more. 3. The civil engineering sheet according to claim 1, wherein the pile length of the pile yarn is 3 cm or less. 4. The civil engineering sheet according to claim 1, wherein the pile yarn is planted on the base cloth by tufting. 5. The civil engineering sheet according to claim 1, wherein the back surface of the base cloth provided with pile yarns is backed.