JP2745324B2 - Geotextile for embankment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a geotextile for embankment which is buried in soil to reinforce the embankment of a road, a construction site or the like, and to prevent embankment of the embankment in soft ground.

[Conventional technology]

Conventionally, various geotextiles for embankment have been used. For example, a drawing net manufactured by extruding a rhombic net or a thick sheet manufactured using a rotary die or the like by an extrusion method, piercing small holes in them, then heating and stretching uniaxially or biaxially, In addition, there is a so-called fiber net in which a convergence body such as a polyester fiber is woven, coated with a synthetic resin, and a warp and a weft are bound. Japanese Utility Model Application Publication No. 51-120129 (Japanese Utility Model Application No. 51-120129) includes a net buried in an embankment having a drainage function.

[Problems to be solved by the invention]

The above-mentioned embankment for embankment has the following problems.

That is, since the rhombic net is manufactured by an extrusion method using a rotary die or the like, if a strong net is required, it is necessary to thicken each thread constituting the net. There was no other way. However, when the yarn is thickened, not only the volume of the whole net becomes large but also the weight is greatly increased, so that there has been a problem that handling and transportation are inconvenient. Also, even if such a thick yarn net is provisionally drawn, there is a problem that there is no accuracy in the size of each yarn, so that a thin portion of the yarn is greatly extended and a thick portion is hardly drawn. However, there is a problem that a net with a uniform eye cannot be formed.

In addition, the above-mentioned stretching net is manufactured by forming many small holes on a thick sheet with high precision and accuracy, and then biaxially stretching the perforated plate. Expensive. An unstretched portion remains at the intersection of the biaxially stretched net, causing imbalance in strength. Also, if unstretching failure occurs in one place to continuously form the net, the net will not be uniform as a product, and the production yield will be poor, resulting in a high cost net. There was a problem.

In addition, when the Rishime net or stretched net is buried in the embankment as it is, it is not necessary to use the water itself but to use a gravel layer and an auxiliary culvert, which not only increases the construction cost but also complicates the construction. Had become something.

In addition, the fiber net is not completely fixed at the intersection of the warp and the weft, but is usually bound with a paste of vinyl chloride or the like. Therefore, there is a problem that the net collapses because it cannot withstand the large pulling force generated when the embankment collapses, deforms the net, receives partial concentrated load, and breaks the net. Further, since the net itself has almost no water-passing ability, there is a problem that the drainage in the embankment must use another member.

Also, in the synthetic resin mesh of Japanese Utility Model Application No. 51-120129, a plurality of strips are fixed to the strip 2 at intervals to give a drainage function to the mesh, and a water-permeable sheet is covered thereon. Although it is a drainage channel, such a buried body has a rigidity itself, so that only a flat-shaped one can be formed, and there is a problem that a long object cannot be transported.

[Means for solving the problem]

The present invention has solved the above problems. That is, a uniaxially stretched synthetic resin band having a width of 2 to 20 mm is used as a warp and a weft, placed at regular intervals, and a band-shaped nonwoven fabric is arranged at regular intervals among these longitudinal and transverse yarns. Yarns are arranged, and the intersections of the yarns are geotextiles that are fixed to each other.By embedding them in the embankment, it is possible to not only reinforce the embankment but also drain the embankment at the same time. It was done.

[Action]

The geotextile of the present invention is uniaxially stretched and has a width of 2 to 20 mm.
The warp and weft yarns are made of synthetic resin strips, and their intersections are fixed, so the net is extremely strong,
In particular, the tensile strength is large, and there is no risk of collapse.
However, if the width is 2 mm or less, the tensile strength is too small for a civil engineering net. If it is more than 20 mm, it is complicated to fix the intersection, and it is expensive and excessive quality for embankment.

When the geotextile of the present invention is buried in an embankment, the upper and lower soils are apparently divided into two by the geotextile, but since there is an interval that can be called a mesh of a net, the upper and lower soils are connected. The soil above and below the geotextile is combined to form a large mass.
Therefore, it functions to suppress the collapse of the slope of the embankment. If the embankment slips in a part, the geotextile receives a large shearing force and a drawing force.However, in the case of the present invention, since the warp and the weft constituting the geotextile are respectively stretched, the geotextile cannot be cut. In addition, since the intersections are fixed at the intersections, they have a strength that can sufficiently withstand the above-mentioned shearing force and pull-out force without causing collapse.

At the same time, since the belt-like nonwoven fabric exists at regular intervals in the warp or weft, water in the embankment is discharged to the outside of the embankment system through the fibers in the nonwoven fabric. That is, the belt-shaped nonwoven fabric of the present invention functions as a path for discharging water, that is, a so-called "water path".

The geotextile of the present invention can be wound because all the components, that is, the warp, the weft, and the belt-shaped nonwoven fabric have flexibility. Therefore, even in a large area, a roll can be made compact, so that it is not bulky, easy to transport, and easy to handle. In addition, since the intersections of the respective yarns are fixed, they are extremely easy to handle as an integrated net without falling apart.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

1, 2 and 3 are perspective views of one embodiment of the present invention, FIG. 4 is a partially enlarged perspective view of the geotextile of the present invention, and FIG. 5 is a perspective view showing an application example. is there. 1 is a warp yarn, 2 is a weft yarn, and 3 is a nonwoven fabric.

Each of the warp 1 and the weft 2 is a uniaxially stretched band made of polypropylene. For such a band, a polyethylene resin, a nylon resin, various polyester resins, and the like are preferably used in addition to the polypropylene resin.

In addition, the method of manufacturing the belt-like body is to extrude a wide thick plate made of a synthetic resin, and in the case of polyolefin or the like, usually 100
C., in the case of a dry method, it is uniaxially stretched 5 to 8 times in the length direction in a temperature range of 120 to 150.degree. C. and slit into appropriate widths. For example, in the case of polypropylene resin,
Extrude a wide plate to a thickness of 2 mm, stretch it 7 to 8 times while heating it to a temperature of 110 ° C, slit it to a width of 15 mm,
Make a 0.5mm tape-shaped strip. Then, these strips are simply arranged vertically and horizontally orthogonally as shown in FIG. 2 or knitted in a plain weave shape as shown in FIG. 1 and placed. Compression bonding by fusion,
Alternatively, a heater is inserted between the intersections 3 of the warp yarns 1 and the weft yarns 2 and then heated and press-integrated or hot-melt resin is heated and melted. The intersection 3 is joined by, for example, causing the intersection 3 to be joined.

In addition, the length of each interval between warp and weft is 15mm-100m
m is preferable. For example, a 25 mm square net made of polypropylene and stretched 8 times with a thickness of 0.7 mm and a width of 15 mm has a light weight of about 400 g per m ² and a tensile strength of about 6 tf / m.

The width of the warp and the weft can be 2 mm or more and 20 mm or less. The tensile strength depends on the type of the synthetic resin and the degree of stretching. Therefore, it is important to properly use the type of resin and the thickness of thread depending on various conditions used, such as the soil quality and height of the embankment.

On the other hand, the nonwoven fabric is preferably as thick as possible and has good water permeability. The thickness and width are not particularly limited, but desirably 0.2 mm to 1.5 mm in thickness and 5 to 5 in width.
It is about 20mm. Care must be taken if the nonwoven fabric is too large, because it may cause slippage in grounds with fine-grained soil silt or iron.

Also, as shown in FIG. 1, the nonwoven fabric 3 may be considered as one of the warp yarns, arranged in a plain weave, and fixed to the weft yarn 2 with an adhesive or hot melt adhesive resin. Further, when the nonwoven fabric is formed of a resin compatible with the weft yarn, for example, the same polypropylene or the like, ultrasonic fusion can be performed as it is, which is a great advantage in manufacturing.

FIG. 2 shows a non-woven fabric 3 disposed between the warp yarns 1. Since the fixation to the weft 2 is performed in the same manner as described above, the description is omitted.

FIG. 3 shows the nonwoven fabric 3 alternately arranged with the warp 1 and the weft 2 respectively. This is suitable for embankment in places where a large amount of water needs to be discharged, such as soft ground or landfill of sludge ponds.

FIG. 4 is a partially enlarged perspective view of the geotextile of the present invention, and shows a state in which the warp yarn 1, the weft yarn 2, and the nonwoven fabric 3 are heat-sealed at the intersections 4 respectively. Since both the warp yarn 1 and the weft yarn 2 are uniaxially stretched, the fixing of the intersection 4 must be performed as instantly as possible. If the heating time is long, care must be taken because the yarn shrinks at and around the intersection, making it extremely unsightly and losing commercial value. Therefore, it is desirable to use ultrasonic bonding or an adhesive capable of exhibiting strength to fix the intersection.

FIG. 5 is a cross-sectional perspective view of an embankment such as a built-up ground. It is laid in a predetermined part on the side. After the laying is completed, the embankment is laid on it until it is about 30 cm to 1.5 m thick, and the process is repeated. As can be seen from the embankment section 10, several layers of geotextile 12 are buried in the embankment to prevent collapse of the embankment. Here, when laying the geotextile 12 of the present invention, care must be taken that the nonwoven fabric 3 is laid so as to be orthogonal to the slope 11. This is because the water in the embankment soaked with rainwater is gradually discharged to the slope 11 through the nonwoven fabric 3, so that the softening of the soil in the embankment is suppressed and the embankment can be stabilized.

In addition, since the geotextile 12 is wound, there is an advantage that the geotextile 12 is easy to carry and has good workability.

In addition, since the warp, the weft, and the nonwoven fabric are flexible, they are well adapted to the soil, and exhibit a strong resistance to the pulling force, which also plays a large role in preventing slippage of the slope of the embankment.

〔The invention's effect〕

As is clear from the above description, when embedded and used in the embankment of the present invention, water in the embankment gradually percolates toward the slope through the fibers of the nonwoven fabric. This has the effect that the nonwoven fabric serves as a drainage channel. Also, since the weft and warp are uniaxially stretched synthetic resin strips, their tensile strength is much stronger than that of conventional nets,
Moreover, since the intersections are fixed, they do not collapse, and can exhibit sufficient strength against the slippage of the embankment. In addition, since all the components, that is, the warp, the weft, and the non-woven fabric have flexibility, they can be made to be long, and the fixing length can be made sufficiently long. In addition, it can be transported in rolls, so it can be transported in large quantities, has excellent workability, can be produced at low cost despite its much increased strength than conventional synthetic resins, and has a drainage function. It has a remarkable effect.

[Brief description of the drawings]

1, 2 and 3 are perspective views showing one embodiment of the present invention, FIG. 4 is a partially enlarged perspective view of the present invention, and FIG.
The figure is a cross-sectional view of an embankment structure using the geotextile of the present invention. 1 ... warp, 2 ... weft, 3 ... non-woven fabric.

Claims (1)

(57) [Claims] A uniaxially stretched synthetic resin strip having a width of 2 to 20 mm is formed as a warp and a weft, and is placed at a fixed interval. The strips are arranged at regular intervals in parallel with the warp or the weft. A geotextile for embankment, wherein the non-woven fabric yarns are arranged, and the intersections of the yarns are fixed respectively.