JP3295065B2 - Geogrid for reinforcing embankment and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a geogrid which is buried horizontally in an embankment to reinforce the embankment, and a method of manufacturing the geogrid for reinforcing the embankment.

[0002]

2. Description of the Related Art A typical geogrid for reinforcing embankment is as follows: (1) A (plastic type) synthetic resin sheet punched in a lattice shape and uniaxially or biaxially stretched.
(2) (Woven fabric type) A lattice-like woven fabric obtained by weaving high-strength synthetic fiber strands as warps and wefts is used as a core material, and the core material is coated with a synthetic resin.

[0003]

The effect of the geogrid for reinforcing the embankment depends entirely on the frictional force between the embankment and the geogrid. Therefore, when the material of the embankment is fine-grained soil, the frictional force between the embankment and the geogrid is significantly reduced due to infiltration water and pore water contained therein, and even if the mechanical strength of the geogrid itself is high, At present, it cannot be put to practical use. In addition, even if the material of the embankment is coarse-grained soil, it is required to use a drainage method together when there are many fine-grained components.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by devising the configuration of a geogrid, and the embankment material that can be employed is not only coarse-grained soil but also fine-grained soil. The aim is to reduce the necessity of using the drainage method together. The invention according to claim 1 of the present application is a geogrid for reinforcing embankment, wherein water guides are incorporated in parallel at appropriate intervals in the vertical direction.

The geogrid body of the present invention except for the water guide is the same or similar to the conventional one, and a plurality of water guides are installed in parallel in the longitudinal direction at appropriate intervals. As the water guiding material, a tape-shaped nonwoven fabric or a hollow plate-shaped flexible drain material is used, which is woven into a horizontal grid of the geogrid and is incorporated in parallel with the vertical grid.

[0006] The width of the water guide material is such that it substantially fills the gap between adjacent vertical grids. The pitch at which the water guide material is incorporated is appropriately selected depending on the type of the embankment material and the core material. In short, every two or three. By incorporating the water-conducting material in this way, the flat area of the geogrid is about 10 to 20% of the grid body,
It is about 50-60%, and the water guide material is about 20-40%.

[0007] As a conventional method of manufacturing a woven fabric type geogrid by coating a core material with a synthetic resin, the core material is immersed in an emulsion of a polyvinyl chloride-based or polyacrylate-based synthetic resin. Thereafter, a method of drying is commonly used. In the present invention, an efficient method of manufacturing a woven fabric type geogrid is a method in which a core material incorporating a water guide material is coated with a synthetic resin by a conventional method, but in this method, the water guide material is simultaneously formed with other materials. This conventional method cannot be used because it is coated with a synthetic resin and impairs its function. For this reason, a water guide material must be incorporated into a geogrid manufactured by a conventional method. In this method, one manufacturing step is added, which is not a good idea. In consideration of this point, the inventors invented a method that does not require a step for a woven-type geogrid. That invention is the invention according to claim 2 of the present application. (In the case of a plastic-type geogrid, it is inevitable to add a step for incorporating a water-conducting material.) That is, the invention according to claim 2 of the present application provides a high-strength synthetic fiber yarn coated with a synthetic resin and a water-conducting water A method of manufacturing a geogrid for reinforcing embankment, characterized in that the warp is made by aligning the materials in the longitudinal direction and the warp is used, and the high-strength synthetic fiber yarn covered with a synthetic resin is woven in a lattice shape as a weft. is there.

According to the present invention, the conventional method of immersing and coating the entire core material in a conventional woven fabric type geogrid with a synthetic resin emulsion at a time is modified to synthesize the warp and weft as raw materials of the core material. The method was immersed and coated with a resin emulsion. By changing the time at which this material is dipped and covered with the synthetic resin emulsion, the entire core material incorporating the water guide material is no longer dipped and covered with the synthetic resin emulsion, so that the function of the incorporated water guide material is impaired. It will not be. Moreover, when the warp of the high-strength synthetic fiber yarn is timed, the water guide is incorporated into the core simply by adding the water guide as a part of the warp and warping at the same time. There is no increase in time and labor, and the efficiency of incorporating the water guide material is extremely good.

The high-strength synthetic fiber yarn used as the warp and the weft in the invention according to the second aspect is not particularly different from that used for the core material of the conventional woven-type geogrid. It is a multifilament yarn of a synthetic fiber (polyester, polyamide, polyvinyl alcohol, etc.) having a high strength of about d. The multifilament yarn has a thickness of about 3000 to 10,000 d. The multifilament yarn is coated with a synthetic resin one by one and used as a warp and a weft for weaving a geogrid. When weaving a geogrid, it is rarely used as warp and weft in the form of a coated multifilament yarn (hereinafter referred to as unit yarn). Usually, a plurality of unit yarns are drawn. Aligned and used as warp and weft in strand form,
Weave in a grid. However, the ears (several millimeters) are of course formed of plain weave instead of lattice, and the warp in this part is not a strand but a rare example used as a unit yarn.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a main part of a geogrid according to the first aspect of the present invention, wherein (a) shows a woven fabric type geogrid and (b) shows a plastic type geogrid. FIG. 2 is a plan view of a woven fabric type geogrid. FIG. 2 (a) shows a case where a strand obtained by aligning a plurality of unit yarns is used as a weft, and FIG. 2 (b) shows a case where a unit yarn is used as a weft. Is shown.

FIG. 3 is a longitudinal sectional view of an example in which the embankment is reinforced using the geogrid of the present invention. Fig. 1 (a) is 6000d
High-strength polyester multifilament yarn coated with polyvinyl chloride resin, and four unit yarns having a thickness of about 10500d are aligned and straight strand 3, weft strand 6
Are warp yarns and weft yarns, and when weaving the geogrid 1 at a pitch of 20 mm in both the vertical and horizontal directions, tape-like nonwoven fabrics 2 each having a width of 15 mm are incorporated in parallel in the longitudinal direction and woven.
FIG. 1 (b) shows a plastic formed by punching a sheet of high-density polyethylene containing carbon black and biaxially stretching it to form a lattice having a mesh size of 60 × 62 mm (length × width) with the vertical grid 4 and the horizontal grid 5. A tape-shaped nonwoven fabric 2 having a width of 55 mm is incorporated between every two adjacent vertical grids 4 of the mold geogrid 1.

In both cases (a) and (b), the pitch at which the tape-shaped nonwoven fabric 2 is incorporated is not limited to every other pitch, but may be every other pitch or every third pitch depending on the soil quality of the embankment material. FIG. 2 shows an example in which five unit yarns identical to those in FIG. 1A are used as warp strands 3, and FIG. 2A shows four unit yarns as in FIG. 1A. The aligned weft strands 6 are used. FIG. 2 (b) shows a structure that is often adopted at the end of the geogrid. In this case, the unit yarn 7 is woven four times as the weft without using the weft strand 6 as the weft. Convenience of the connection between the grids and the connection with the support material or the slope is improved. As described above, the woven fabric type geogrid of the present invention does not need to have a single woven structure as a whole, and appropriately changes the number of unit yarns constituting the strands and the pitch of the strands depending on the purpose depending on the portion. You may. Although not shown, other warp yarns may be used in addition to the warp strands 3 to reinforce the intersections between the warp strands 3 and the weft strands 6 by weaving or the like.

FIG. 3 shows an example of the use of the geogrid of the present invention. In this example, laying of the geogrid, embankment, compaction of the embankment, and protection of the slope are repeated several times to fill the geogrid to a predetermined height. This is an example, and there is no particular difference from the usage example of the conventional geogrid. In this case, a support material 8 (steel pipe, reinforcing bar, etc.) is attached to the end of the geogrid on the back side of the embankment to support the geogrid, and the end of the geogrid on the slope side is entangled in a vegetation sandbag 9. Although not shown, a normal framing work is performed on the surface of the sandbag 9 for vegetation.

[0014]

The present invention is as described above. By using the geogrid of the present invention, not only conventional coarse-grained soil but also fine-grained soil can be used as embankment material.
Therefore, the width of the usable embankment material is expanded, and most of the soil generated in the field can be used as the embankment material. In addition, the necessity of using the drainage method together is reduced as compared with the conventional geogrid.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a geogrid of the invention according to claim 1, wherein (a) shows a woven fabric type geogrid;
(B) shows a plastic geogrid.

FIG. 2 is a plan view of a woven fabric type geogrid. FIG. 2 (a) shows a case where a strand obtained by aligning a plurality of unit yarns is used as a weft, and FIG. 2 (b) shows a case where a unit yarn is used as a weft. Show the case.

FIG. 3 is a longitudinal sectional view of an example in which embankment is reinforced using the geogrid of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Geogrid, 2 ... Tape-like nonwoven fabric, 3 ... Trans strand, 4 ... Trans grid, 5 ... Weft grid, 6 ... Weft strand, 7 ... Unit yarn, 8 ... Support material, 9 ... Sandbag for vegetation

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E02D 17/18 E02D 3/00

Claims (2)

(57) [Claims] 1. An appropriate space on a horizontal grid of a geogrid
The water-guiding material is woven in the vertical grid of the geogrid.
An embankment characterized by being incorporated parallel to the lid
Geogrid for reinforcement. 2. A high-strength synthetic fiber yarn coated with a synthetic resin.
The warp is made by aligning the water-conducting material vertically and warping it.
The high-strength synthetic fiber yarn covered with synthetic resin is used as the weft,
And the light yarn and the weft are formed by weaving in a lattice shape.
How to manufacture a geogrid for embankment reinforcement characterized by becoming
Law.