JP2008208604A - Slope protection mat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slope protection mat which is excellent in drainability for eliminating percolating water produced by rainfall, snow melting, etc. and partially constituting the causes of frost heaving, and which can suppress the erosion and collapse of a slope by reducing the looseness of a soil layer by the frost heaving. <P>SOLUTION: In this slope protection mat, a vegetation base layer 5, a top surface covering sheet 6, and an undersurface covering sheet 7 are superposed together. In the vegetation base layer 5, a gap 2 in a flat plate-like three-dimensional net-like structure 1, which is molded from a thermoplastic resin material, is filled with a vegetation base material 4 containing seeds 3. The top surface covering sheet 6, which covers a top surface of the vegetation base layer 5, is equipped with a gap from which plants can put forth buds. The undersurface covering sheet 7, which covers an undersurface of the vegetation base layer 5, is equipped with a gap through which a plant root can pass. The net-like structure 1 is formed by accumulating many monofilaments in a random loop shape, and a plurality of tubular cavity portions 8, which enables smooth drainage, are provided in line in the thickness portion of the net-like structure 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a slope protection mat that effectively prevents erosion / collapse due to freezing on slopes such as a slope or natural slope in a cold region.

  In general, if you leave the slopes such as slopes, natural slopes, etc., in the bare land as they are, the slopes are eroded by rain or melted snow, and eventually collapse occurs. There are situations where people's lives are at risk or the landscape is bad. In order to prevent the erosion / disintegration of the slope, for example, a structure in which a vertical frame and a horizontal frame made of concrete are constructed in a grid pattern on the slope (for example, refer to Patent Document 1), extending in at least one direction and A structure in which a large number of box-shaped slope members with openings at the top are built in a lattice pattern on the slope and planted inside the frame (see, for example, Patent Document 2), or a net A construction (for example, see Patent Document 3) is adopted in which a soil retaining material produced by containing wood is laid on the slope, and the decomposed soil retaining material also serves as a vegetation base material to greenen the slope. Yes.

Utility Model Registration No. 3074535 (page 5-7, FIG. 1) JP-A-9-88074 (page 3-4, FIG. 4) JP 2001-172977 A (page 2-3, FIG. 1)

  By the way, as described above, the device for protecting the slope is taken even in cold regions, but in cold regions, frost columns are formed in the soil due to freezing of permeated water due to rain, snow melting, etc. When this occurs, the soil layer on the surface is lifted up, and this phenomenon is repeated. When this phenomenon occurs, the frame and the retaining material of Patent Documents 1 to 3 are pushed up from below and deformed and destroyed. In early spring, a large amount of infiltrated water due to heavy rain and snow melting in the cavities in the soil layer. The current situation is that it is difficult to achieve the original purpose of slope protection due to the accumulation and the cause of the slope erosion / collapse.

  Therefore, the present invention has been made in view of the above problems, and is excellent in drainage that eliminates infiltrated water due to rainfall, snow melting, etc., which is one of the causes of frost heave, and reduces loosening of the soil layer due to frost heave. An object of the present invention is to provide a slope protection mat that can suppress slope erosion and collapse.

  In order to achieve this object, the slope protection mat includes a vegetation base layer in which a vegetation base material containing seeds is filled in a gap in a flat three-dimensional network structure formed of a thermoplastic resin material, and the vegetation base Formed by laminating an upper surface covering sheet that covers the upper surface of the layer and has a gap through which plants can sprout, and a lower surface covering sheet that covers the lower surface of the vegetation base layer and has a space through which plant roots can penetrate The three-dimensional network structure has a cylindrical hollow portion that is formed by depositing a large number of monofilaments in a random loop shape and that can smoothly drain water in the thickness portion thereof. It is characterized by being arranged in multiple rows.

  At this time, it is preferable that the upper surface covering sheet is formed in a cocoon shape from a natural material such as cocoon or jute.

  Moreover, it is preferable that the said lower surface coating sheet is a nonwoven fabric.

  The slope protection mat according to the present invention includes a vegetation base layer in which a vegetation base material containing seeds is filled in a gap in a three-dimensional network structure formed of a thermoplastic resin material, and a plant that covers the top surface of the vegetation base layer. It is formed by laminating an upper surface covering sheet with a gap that can be put out and a lower surface covering sheet with a gap that covers the lower surface of the vegetation base layer and through which the roots of the plant can penetrate, and within the thickness part of the three-dimensional network structure Since multiple cylindrical cavities that can be smoothly drained are arranged in a row, direct erosion due to rainfall is prevented by the top cover sheet, and the permeated water before deeply penetrating into the slope Is discharged downward through the cylindrical cavity, and the frost heaving phenomenon on the slope is suppressed. This makes it difficult for erosion / collapse to occur even on cold slopes, and eliminates situations that endanger human life or worsen the landscape. In addition, the slope protection mat has a simple structure in which the upper and lower surface covering sheets and the intermediate vegetation base layer are laminated and integrated, and since it only needs to be laid on the slope, it can be provided at low cost and can be installed. There is an effect that it is easy and construction costs can be reduced.

  In addition, when the top cover sheet is formed in a cocoon shape from a natural material such as cocoon or jute, there are many gaps, and when buds emerge from the seeds, young leaves tend to come out from the gaps and are suitable for growing them. .

  Furthermore, when the lower surface covering sheet is formed of a nonwoven fabric, when the roots emerge from the seeds, the roots easily pass through the gaps in the nonwoven fabric and are excellent in water permeability.

  Hereinafter, embodiments of a slope protection mat according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a partially enlarged perspective view of a slope protection mat according to the present invention, and FIG. 2 is a partially enlarged side sectional view showing a manufacturing stage of the slope protection mat. The slope protection mat A includes a vegetation base layer 5 in which a vegetation base material 4 containing seeds 3 is filled in the gaps 2 in the flat three-dimensional network structure 1, and an upper surface that covers the top surface of the vegetation base layer 5 It is formed by laminating a covering sheet 6 and a lower surface covering sheet 7 that covers the lower surface of the vegetation base layer 5.

  The three-dimensional network structure 1 is made of, for example, a thermoplastic resin such as polypropylene. For example, the width is 1 m, the length is 4 m, the thickness is 20 mm, the weight is 1200 g / m, the compressive strength is 20% and the compression property is 49 KN / square meter. Superior to acid and microbial resistance. More specifically, the three-dimensional network structure 1 is provided with a plurality of cylindrical cavities 8 arranged in a row along the longitudinal direction in the thickness portion as shown in FIG. A covering layer 9 is formed on one side surface of 8, 8. As the thermoplastic resin, there are polyethylene and polyethylene terephthalate in addition to polypropylene. Polypropylene is preferred because it is inexpensive and has excellent durability.

  Next, a manufacturing method of the three-dimensional network structure 1 will be described without showing. The molten monofilament is dropped into the water tank from a plurality of nozzles arranged in parallel in two rows. Each monofilament dropped into the water storage is spirally wound so as to have a substantially circular planar shape of approximately the same size as that of nature, and at least some of them are fused and entangled. The monofilament thus formed is passed between a pair of receiving rolls. The space between the receiving rolls is set to a dimension about the thickness width of the cylindrical hollow portions arranged in a row, and when passing between the both receiving rolls, a loop is formed on one side surface of the cylindrical hollow portions 8, 8,. As a result, the coating layer 9 deposited in a crushed state is formed. The three-dimensional network structure 1 is excellent in air permeability and water permeability, and each cylindrical cavity 8 is for smooth drainage.

  The lower surface covering sheet 7 is formed from a nonwoven fabric having the same area as the three-dimensional network structure 1. The nonwoven fabric includes both natural fibers and chemical fibers, and is preferably excellent in both air permeability and water permeability, and preferably has a gap through which a plant root can penetrate. In addition, as long as these conditions are satisfied, for example, a woven fabric or a net-like material made of a natural material, a recycled natural material, or a synthetic resin material may be used. Then, as shown in FIG. 2 (b), the lower surface covering sheet 7 is superimposed on the back surface of the covering layer 9, and the stapler 10 is driven into the appropriate position to fix the lower surface covering sheet 7. The lower surface covering sheet 7 also functions to prevent the vegetation base material 4 filled in the three-dimensional network structure 1 from being unnecessarily spilled.

The vegetation base material 4 is a mixture of a soil conditioner, fertilizer and seeds. A soil improvement material consists of a fine-grained inorganic type soil improvement material as well as a fine-grained organic soil improvement material, and a fertilizer consists of a quick-acting fertilizer, a slow-acting fertilizer, and a phosphate fertilizer. As seeds, Kusayoshi, Iwanogalias, Oogigi and Kusafuji are used, but usually native species rooted in the construction area are desirable. These are based on, for example, the following allocation per square meter of vegetation base material.
Organic soil conditioner: 20 liters Kusaiyoshi: 1.82 g
Inorganic soil conditioner: 500g Ivano Gallias: 0.45g
Immediately effective fertilizer: 100g Great mugwort: 0.60g
Slow-release fertilizer: 60 g Kusafuji: 0.60 g
Phosphate fertilizer: 80g
The seed, soil improvement material, and fertilizer are mixed as appropriate, and the gap 2 in the three-dimensional network structure 1 is filled to the height as shown in FIG. In this way, the vegetation base layer 5 is formed by filling the vegetation base material 4 in the three-dimensional network structure 1.

  The top cover sheet 6 also has the same area as the three-dimensional network structure 1. The upper surface covering sheet 6 may be formed in a bowl shape with a cocoon that is a natural material, and may be formed by forming a natural material such as jute in a bowl shape. Then, as shown in FIG. 2 (d), the upper surface covering sheet 6 is overlaid on the surface of the vegetation base layer 5, and the stapler 10 is driven in place to fix the upper surface covering sheet 6 to the three-dimensional network structure 1. This is because even when seeds grow and sprout, young leaves tend to come out from the gaps and are suitable for growing them. Further, depending on the climate of the land, the top cover sheet 6 is made of a synthetic resin material, and the mesh shape is a mesh having a size such that the seeds 3 and the vegetation base material 4 do not fall and the seed buds can pass through. The sheet may be used.

  The slope protection mat A according to the present invention has the above-described configuration. Next, a construction method for laying on the slope and the laid state will be described. 3 is a perspective view showing a state in which a slope protection mat is laid on the slope, FIG. 4 is a sectional side view thereof, and FIG. 5 is an enlarged side sectional view of the same portion. A substantially horizontal flat portion B is formed at the upper end of the slope H, and a net-like box frame filled with many pebbles, so-called futon cages F, is arranged in a row along the lower end of the slope H. ing. Then, about 1 m is left on the upper flat surface B so as to cover the flat surface B, and the slope protection mat A is laid downward from the slope H therefrom. At this time, the respective cylindrical cavities 8 of the three-dimensional network structure 1 are directed along the slope H in the vertical direction. Then, a plurality of fixing piles 11 are driven into the slope H from the upper surface of the slope protection mat A. Furthermore, on this slope H, another slope protection mat A is laid continuously below the slope. By repeating this operation, a plurality of slope protection mats A are laid so as to cover the slope H.

  The slope protection mat A thus formed was laid on an actual slope in a cold region during the winter season, and the experiment was conducted. As a result, the slope H covered with the slope protection mat A according to the present invention was obtained. Was protected from erosion and collapse until early spring.

  Thereafter, buds and roots emerge from the seed 3, and the buds grow from the gaps of the cocoon buds, which are the upper surface coating sheet 6, and contribute to the greening of the slope H, and the roots are the lower surface coating sheet 7. It penetrates the non-woven fabric and extends into the formation, roots in the formation, and firmly fixes the soil layer.

  Usually, the soil layer on the slope H has more cavities due to freezing and large-scale erosion occurs due to intrusion of early spring rainfall and snowmelt water. However, in the slope protection mat A according to the present invention, direct erosion by rainfall and snowmelt water is prevented by the top cover sheet 6, and the excess water is further removed before deeply penetrating into the slope H. The liquid is discharged downward through each cylindrical cavity 8. Thereby, the frost heaving phenomenon of the slope H is suppressed. Therefore, erosion / collapse is unlikely to occur even on a slope H in a cold region, and the situation of endangering human life or worsening the landscape is eliminated. Further, the slope protection mat A has a simple structure in which the upper and lower surface covering sheets 6 and 7 and the intermediate vegetation base layer 5 are laminated and integrated, and only has to be laid on the slope H. In addition to being provided at a low cost, the construction is easy and the construction cost can be reduced.

  The upper and lower surface covering sheets 6 and 7 are each fixed to the three-dimensional network structure 1 by the stapler 10, but may be fixed by an adhesive or hot melt. Further, the slope protection mat A according to the present invention exhibits its function in a cold region, but it goes without saying that the original effect can be sufficiently exerted in a region other than the cold region.

1 is a partially enlarged perspective view of a slope protection mat according to the present invention. (A)-(d) is a partially expanded side sectional view which shows the manufacturing step of the slope protection mat. The perspective view of the state which laid the slope protection mat on the slope. FIG. The same part expanded side surface sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 3D network structure 2 Crevice 3 Seed 4 Vegetation base material 5 Vegetation base layer 6 Upper surface covering sheet 7 Lower surface covering sheet 8 Cylindrical cavity A A Slope protection mat H Slope

Claims (3)

A vegetation base layer in which a vegetation base material containing seeds is filled in a gap in a flat three-dimensional network structure formed of a thermoplastic resin material; A slope protection mat formed by laminating an upper surface covering sheet provided with a gap that can be formed, and a lower surface covering sheet provided with a gap that covers the lower surface of the vegetation base layer and through which a plant root can penetrate,
The three-dimensional network structure is formed by depositing a large number of monofilaments in a random loop shape, and a plurality of cylindrical hollow portions that can smoothly drain water are provided in the thickness portion. Slope protection mat.   The slope protection mat according to claim 1, wherein the top cover sheet is formed in a cocoon shape from a natural material such as cocoon or jute.   The slope protection mat according to claim 1 or 2, wherein the lower surface covering sheet is a nonwoven fabric.

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