JP2024117392A - Soil erosion prevention mat, slope soil protection structure, and method for preventing soil erosion of slope soil - Google Patents

Abstract

A soil erosion prevention mat is provided that enables easier and more effective protection of slope soil.
[Solution] A soil erosion prevention mat 100 comprises a flexible mat body 101 extending lengthwise and widthwise, with the lengthwise direction aligned along the inclination direction of the sloping soil, and configured to reduce erosion of the soil surface, and one or more flow velocity reduction materials 110 attached to the surface of the mat body 101 for reducing the flow velocity of running water flowing over the surface of the sloping soil. The flow velocity reduction materials 110 are formed in an elongated cylindrical shape extending across the entire width of the mat body 101, and are configured to form a dam having a predetermined height in the vertical direction from the surface of the mat body 101.
[Selected Figure] Figure 1

Description

The present invention relates to a soil erosion prevention mat that is installed on a slope to reduce soil erosion of the slope, a slope soil protection structure using the soil erosion prevention mat, and a method for protecting slope soil using the soil erosion prevention mat.

In recent years, intermittent rainfall and torrential rains have caused erosion of the soil surface on slopes, resulting in disasters such as landslides. A variety of measures have been implemented to reduce or prevent soil erosion on slopes.

Patent Document 1 discloses a sheet-like material for preventing soil erosion that adheres closely to the soil surface to prevent soil erosion. In the following paragraphs, the reference number of Patent Document 1 is shown in parentheses. The long sheet-like material for preventing soil erosion (1) is made of synthetic resin and/or natural fibers, and has a bulkiness and flexibility of 5 to 20 mm in thickness. Substantially the entire upper surface of the long sheet-like material (1) of a predetermined width is covered with a reinforcing net (2), and the reinforcing net (2) and the long sheet-like material (1) are connected only in the vicinity of both the left and right ends in the length direction. The reinforcing net (2) connected to the long sheet-like material (1) is used to drive anchor pins (4) at appropriate intervals, so that the long sheet-like material (1) is connected to the soil (5) by the anchor pins (4) via the reinforcing net (2). The flexible long sheet-like material (1) sags under its own weight and adheres well to uneven and uneven soil (5). In addition, when it rains, the long sheet material (1) absorbs water and gains weight, allowing it to adhere to the ground even on uneven or uneven surfaces. In other words, it easily adheres to the soil even on uneven or uneven surfaces, effectively preventing soil erosion.

Patent Document 2 discloses a log structure that uses logs to prevent the runoff of surface soil on a slope. In the following paragraphs, the reference number of Patent Document 2 is shown in parentheses. The log structure (1) is installed on a slope as a log brace, and is formed to prevent the runoff of surface soil and protect vegetation. The main part of the structure is composed of logs (11) arranged in a substantially horizontal direction on the ground (15) of the slope, a number of upper stacked logs (12) stacked on top of the logs, a fully threaded steel bar (13) that penetrates the logs (11) and the upper stacked logs (12) in the vertical direction and penetrates into the ground, and a nut (14) that is twisted to the top of the fully threaded steel bar (13) and tightened on the top of the upper stacked log (12). Such log braces are generally constructed to dam surface water flowing down a slope and to increase the flow velocity reduction effect and rainwater dispersion effect.

JP 10-60901 A Patent Publication No. 2021-25314

By covering the surface of the slope soil with an erosion prevention mat as in Patent Document 1, it is possible to mitigate the impact of raindrops and reduce sediment runoff, but covering the slope soil alone is not effective in reducing the flow rate of surface water, and therefore the slope soil cannot be protected sufficiently. Therefore, particularly in mountainous areas, log reinforcing bar work as in Patent Document 2 can be used in combination with the mat to provide the effect of reducing the flow rate of surface water by the log reinforcing bar work. However, when a mat is laid on a slope soil on which log reinforcing bar work has been formed, it is inevitable that the mat will break and there will be places where the surface cannot be protected. The problem is that erosion damage will increase intensively from such places where the mat is broken, and waterworks will be formed underground, which may lead to even larger-scale landslides. Another problem is the effort and labor required to build log reinforcing bar work on slope soil. Therefore, the inventors aimed to provide a soil erosion prevention mat that can protect slope soil by reducing the flow rate of surface water and reducing soil runoff without causing the above-mentioned problems.

The present invention has been made to solve the above problems, and its purpose is to provide a soil erosion prevention mat that allows for easier and more effective protection of slope soil, a slope soil protection structure using said soil erosion prevention mat, and a method for protecting slope soil using a soil erosion prevention mat.

A soil erosion prevention mat according to one embodiment of the present invention is a soil erosion prevention mat that is installed on a slope soil in order to reduce soil erosion,
A flexible mat body extending lengthwise and widthwise, the lengthwise direction being arranged along the inclination direction of the slope soil, and configured to reduce erosion of the soil surface;
and one or more flow velocity reducing materials attached to the surface of the mat body for reducing the flow velocity of running water flowing on the surface of the slope soil;
The flow velocity reduction material is formed in a long cylindrical shape extending across the entire lateral direction of the mat body and is configured to form a dam having a predetermined height in the vertical direction from the surface of the mat body.

According to one embodiment of the soil erosion prevention mat of the present invention, the flexible mat body covers the slope soil, thereby reducing the runoff of soil and sand. In addition, a long cylindrical flow rate reducing material extending across the entire width of the mat body is attached to the surface of the mat body to form a dam with a predetermined height vertically from the surface of the mat body, which also reduces the flow rate of surface water without creating any discontinuous areas in the mat body. Therefore, the soil erosion prevention mat of the present invention is capable of covering the protected area of the slope soil without interruption while reducing the flow rate of surface water. Furthermore, by attaching the flow rate reducing material to the surface of the mat body, the soil erosion prevention mat of the present invention can reduce the flow rate of surface water similarly to log reinforcement work, and can improve the effort required to protect the slope soil compared to the past.

A further embodiment of the soil erosion prevention mat of the present invention is characterized in that in the soil erosion prevention mat of the above embodiment, the flow velocity reduction material comprises a bag body and a filler material containing granular material having a grain size or particle diameter of at least 10 mm or less, which is filled into the bag body. The flow velocity reduction material can be easily prepared by filling the bag body with the filler material. In addition, by using granular material having a grain size or particle diameter of 10 mm or less as the filler material, the granular material densely fills the gaps inside the bag body and can move relatively freely inside the bag body, making it possible to easily change the external shape of the flow velocity reduction material to suit the installation environment.

A further embodiment of the soil erosion prevention mat of the present invention is characterized in that in the soil erosion prevention mat of the above embodiment, the flow velocity reduction material comprises a bag body and a filler material containing at least wood chips that is filled into the bag body. The flow velocity reduction material can be easily prepared by filling the bag body with wood chips, and since it is relatively lighter than round wood, it can be more easily applied.

A further embodiment of the soil erosion prevention mat of the present invention is characterized in that, in the soil erosion prevention mat of the above embodiment, the flow velocity reduction material is raised vertically from the surface of the mat body to a height of 5 to 13 cm. In other words, by attaching the flow velocity reduction material to the surface of the mat body, a dam of appropriate height can be formed on the surface of the sloping soil, and the effect of reducing the flow velocity of surface water can be effectively achieved without impeding workability.

A further embodiment of the soil erosion prevention mat of the present invention is characterized in that in the soil erosion prevention mat of the above embodiment, the connection between the flow velocity reduction material and the surface of the mat body is formed in a straight line or in a dot shape in the longitudinal direction of the flow velocity reduction material. In other words, by making the connection between the flow velocity reduction material and the surface of the mat body a single point in the vertical width direction, when a force in the vertical direction of the mat body is applied to the flow velocity reduction material, the flow velocity reduction material can move vertically with the connection as a fulcrum, thereby preventing the mat body from being pulled by the flow velocity reduction material and lifting off the soil surface or tearing.

A further embodiment of the soil erosion prevention mat of the present invention is characterized in that, in the soil erosion prevention mat of the above embodiment, the flow velocity reduction material has a band-shaped connecting strip extending from the bag body in a width direction perpendicular to the longitudinal direction of the flow velocity reduction material, and the connecting strip is connected to the surface of the mat body with a surface extending parallel to the surface of the mat body as a connecting part. In other words, by connecting the surface of the band-shaped connecting strip extending from the bag body to the surface of the mat body as a connecting part, the flow velocity reduction material can be more firmly connected to the surface of the mat body. Furthermore, since the bag body is connected to the surface of the mat body via the connecting strip, when a force is applied to the flow velocity reduction material in the vertical direction of the mat body, the flow velocity reduction material can move vertically relative to the connecting strip, which prevents the mat body from being pulled by the flow velocity reduction material and lifting off the soil surface or tearing.

A further embodiment of the soil erosion prevention mat of the present invention is characterized in that, in the soil erosion prevention mat of the above embodiment, the flow velocity reduction material has a flexible deformation portion at at least one end in the longitudinal direction, which overlaps with the mat body at a first length, protrudes from the lateral edge of the mat body at a second length, and is capable of being deformed by bending so as to move away from the surface of the mat body. That is, the end of the flow velocity reduction material can be deformed so as to rise up from the surface of the mat body at the edge of the mat body via the flexible deformation portion. This allows adjacent flow velocity reduction materials to be continuously arranged without interruption in the contour direction of the slope soil when multiple soil erosion prevention mats are arranged adjacent to each other in the lateral direction, and the edges of adjacent mat bodies can be laid overlapping each other in the contour direction. In particular, by inserting the flow velocity reduction material of one soil erosion prevention mat between the flow velocity reduction material of the other soil erosion prevention mat that has been flexibly deformed and the mat body, adjacent flow velocity reduction materials can be arranged at the same level of the slope soil without interfering with each other. Therefore, it is possible to effectively protect slope soil by using multiple soil erosion prevention mats.

A further embodiment of the soil erosion prevention mat of the present invention is characterized in that in the soil erosion prevention mat of the above embodiment, the mat body is formed from a cotton-like layer of a predetermined thickness. That is, the cotton-like sheet layer of the mat body effectively absorbs the impact of raindrops, and the cotton-like fibers can capture soil particles and suppress their movement. Furthermore, by moving surface water through the cotton-like layer, the amount of surface water flowing into the soil can be reduced, and drainage treatment within the mat can be effectively promoted.

A further embodiment of the soil erosion prevention mat of the present invention is characterized in that, in the above-mentioned soil erosion prevention mat, it further comprises a greening material attached to the mat body. In other words, by placing the soil erosion prevention mat on a slope, it is possible to reduce the erosion of the slope soil while simultaneously promoting soil greening by plants.

A slope soil protection structure according to one embodiment of the present invention is a slope soil protection structure in which a plurality of soil erosion prevention mats according to the above embodiment are installed in a protection area of the slope soil,
The method is characterized in that a plurality of flow velocity reduction materials are arranged continuously and uninterruptedly in the contour direction of the slope soil, and a plurality of mat bodies cover the soil surface of the protection area without exposing it.

A method according to one embodiment of the present invention is a method for protecting a slope soil so as to prevent soil erosion by installing a plurality of soil erosion prevention mats of the above-described embodiment in a protection area of the slope soil,
The flow velocity reducing materials of the soil erosion prevention mats adjacent in the horizontal direction are arranged so as to be continuous without interruption in the contour line direction of the slope soil,
The soil erosion prevention mats are characterized in that the edges of the mat bodies of adjacent soil erosion prevention mats are arranged so as to overlap each other.

The soil erosion prevention mat, slope soil protection structure, and method for protecting slope soil of the present invention reduce the flow rate of surface water and reduce soil runoff, making it possible to protect slope soil more easily and effectively.

1 is a schematic perspective view of a soil erosion prevention mat according to one embodiment of the present invention; FIG. 2 is a partially enlarged perspective view of the soil erosion prevention mat of FIG. 1 . 3 is a cross-sectional view of the soil erosion prevention mat shown in FIG. 2 along line A-A. FIG. 4 is an exploded view of the soil erosion prevention mat of FIG. 3. 3 is a cross-sectional view of the soil erosion prevention mat shown in FIG. 2 along the line B-B. 1 is a schematic perspective view of an entire slope soil protection structure according to one embodiment of the present invention; FIG. 7 is a partially enlarged perspective view of the slope soil protection structure of FIG. 6 . FIG. 8 is a cross-sectional view of the slope soil protection structure of FIG. FIG. 8 is a longitudinal sectional view of the slope soil protection structure of FIG. FIG. 4 is a schematic diagram showing a modified example of the soil erosion prevention mat of the present invention. FIG. 4 is a schematic diagram showing a soil erosion prevention mat according to another embodiment of the present invention. FIG. 12 is a partially enlarged view of the soil erosion prevention mat of FIG. 11 .

The following describes an embodiment of the present invention with reference to the drawings. Note that the shapes of the figures referred to in the following description are conceptual or schematic diagrams for explaining preferred shapes and dimensions, and the dimensional ratios do not necessarily match the actual dimensional ratios. In other words, the present invention is not limited to the dimensional ratios in the drawings.

The soil erosion prevention mat 100 of one embodiment of the present invention is installed on sloping soil such as a slope, thereby covering the soil surface and preventing soil erosion. Although the soil erosion prevention mat 100 of this embodiment is configured to be installed on sloping soil, it goes without saying that it may also be installed on a flat surface that is not inclined. In this specification, when the soil erosion prevention mat 100 is laid on sloping soil, the direction along the slope direction of the slope is defined as the "vertical" direction, and the direction along the contour line direction of the slope is defined as the "horizontal" direction. Furthermore, when the soil erosion prevention mat 100 is laid on sloping soil, the side that is placed on the toe side (upper or higher side) is defined as the "upper" position, and the side that is placed on the toe side (lower or lower side) is defined as the "lower" position.

Figure 1 is a schematic perspective view of a soil erosion prevention mat 100 according to one embodiment of the present invention. Figure 2 is a partially enlarged perspective view of the soil erosion prevention mat 100. Figure 3 is an A-A cross-sectional view of the soil erosion prevention mat 100. Figure 4 is an exploded view of the soil erosion prevention mat 100. Figure 5 is a B-B cross-sectional view of the soil erosion prevention mat 100. As shown in Figures 1 to 5, the soil erosion prevention mat 100 includes a flexible mat body 101 that extends lengthwise and widthwise, with the lengthwise direction aligned with the inclination direction of the slope soil and configured to reduce erosion of the soil surface, and a flow velocity reduction material 110 that is attached to the surface of the mat body 101 and reduces the flow velocity of running water flowing on the surface of the slope soil. In this embodiment, multiple flow velocity reduction materials 110 are attached to one mat body 101 that is long in the lengthwise direction, but one flow velocity reduction material 110 may be attached to one mat body 101.

The mat body 101 is a flexible sheet that extends lengthwise and widthwise so as to cover the protection area of the slope soil and protect the slope soil. The mat body 101 is configured so that, due to its flexibility or pliability, it can adhere closely to the surface of the slope soil having unevenness or undulations when laid. In this embodiment, the mat body 101 is configured from a cotton-like sheet 102 of a predetermined thickness and a mesh sheet 103 attached to the surface side of the cotton-like sheet 102. In this embodiment, the cotton-like sheet 102 is formed from synthetic resin fibers or natural fibers into a cotton-like shape so as to have a thickness of preferably 20 mm or less. More specifically, the cotton-like sheet 102 preferably has a thickness of 3 to 20 mm. In addition, the cotton-like sheet 102 of this embodiment is preferably processed so that the fiber basis weight is about 80 g/m ² or less so as not to inhibit the germination of plants. More specifically, the fiber basis weight is preferably 20 to 80 g/m ² . The cotton-like sheet 102 effectively absorbs the impact of raindrops from heavy rain, and the cotton-like fibers can capture soil particles and effectively suppress their movement. Furthermore, the cotton-like sheet 102 reduces the amount of surface water that flows into the soil by moving through the layer of the cotton-like sheet 102, making it possible to effectively promote drainage treatment within the soil erosion prevention mat 100. The mesh sheet 103 is formed by weaving synthetic resin fibers or natural fibers vertically and horizontally with a specified mesh size, and reinforces the cotton-like sheet 102 from the surface side.

The flow velocity reduction material 110 is attached to the surface of the mat body 101 so as to reduce the flow velocity of the running water (surface water) flowing on the surface of the slope soil. The flow velocity reduction material 110 is formed in a long cylindrical shape extending across the entire width of the mat body 101, and is configured to form a dam with a predetermined height vertically from the surface of the mat body 101. In this embodiment, multiple flow velocity reduction materials 110 are arranged vertically at intervals on one mat body 101. This interval is preferably about 0.5 to 5 m. In addition, the longitudinal length of the flow velocity reduction material 110 is greater than the width of the mat body 101. In other words, the flow velocity reduction material 110 extends so as to protrude from both edges of the mat body 101 in the width direction. In addition, it is preferable that the flow velocity reduction material 110 protrudes vertically from the surface of the mat body 101 to a height of 5 to 13 cm so as to function as a dam. More specifically, the flow velocity reduction material 110 of this embodiment preferably has a circular or elliptical shape in the cross-sectional view shown in Figure 3, and has a circumference of about 25 to 40 cm. If the flow velocity reduction material 110 is smaller than the above-mentioned size, the flow velocity reduction effect will be small, and conversely, if it is larger than the above-mentioned size, workability will be poor.

As shown in FIG. 3, the flow-reducing material 110 comprises a bag 111, a filler 112 filled in the bag 111, and a connecting portion 114 having a connecting portion 115 between the flow-reducing material 110 and the surface of the mat body 101. Unlike logs and the like, the flow-reducing material 110 can change its external shape to a certain extent by moving the filler 112 inside the bag 111. In other words, the flow-reducing material 110 can change its shape to match the unevenness and undulations of the slope soil on which it is installed.

The bag body 111 is composed of a long, tubular nonwoven bag and a resin net that covers the nonwoven bag. This resin net is integrally molded from a synthetic resin that is flexible and elastic. This type of resin net is formed as a so-called "non-woven net" that is integrally molded from synthetic resin, and therefore has higher strength and durability than nets formed by weaving wires.

The filler 112 is also configured to include at least wood chips. Wood chips can be easily and economically obtained by crushing thinned wood or waste wood. In this embodiment, the filler 112 is composed only of wood chips. Wood chips generally have a random shape, but are preferably granular bodies (small pieces, fragments) having a grain size or particle size of about 10 mm or less. However, the filler 112 may include granular bodies such as soil, soil improvement material, crushed urethane, waste paper, resin pieces, and gravel in addition to wood chips. Alternatively, the filler 112 may include granular bodies such as crushed urethane, waste paper, resin pieces, and gravel instead of wood chips. That is, the filler 112 can be arbitrarily selected from materials capable of reducing the flow rate. The granular bodies are preferably materials or sizes having a grain size or particle size of 10 mm or less and being able to be stably maintained inside the bag body 111 without dissolving in water. If the granular material is 10 mm or less, it densely fills the gaps inside the bag body 111 and can move relatively freely inside the bag body 111, so the outer shape of the filler material 112 can easily be deformed to suit the installation environment. Furthermore, in addition to the granular material having a grain size or particle size of 10 mm or less, the filler material 112 may also contain lumps such as wood chips having a grain size or particle size larger than that.

The connecting portion 114 extends in a strip shape from the bag body 111 in the width direction perpendicular to the longitudinal direction of the flow velocity reduction material 110. As shown in FIG. 3, the connecting portion 114 is connected to the surface of the mat body 101 with a surface extending parallel to the surface of the mat body 101 as the connecting portion 115. In this embodiment, the connecting portion 114 is formed as a binding portion of a resin net. This connecting portion 114 can be freely folded and deformed with respect to the bag body 111. As shown in FIG. 4, the connecting portion 114 hanging down from the bag body 111 is folded so as to be parallel to the surface of the mat body 101, and then one surface (connecting portion 115) of the connecting portion 114 is connected to the surface of the mat body 101, so that the flow velocity reduction material 110 can be attached to the surface of the mat body 101. Specifically, the connecting portion 115 is connected to the mat body 101 in its entirety or in part using a C-ring, staple, adhesive, or the like. Additionally, the connection margin 114 and the connecting portion 115 connect the longitudinal center region of the flow velocity reduction material 110 to the surface of the mat body 101, but are configured so that the end regions are not connected to the surface of the mat body 101.

The flow velocity reduction material 110 has a flexible deformation portion 116 at the end in the longitudinal direction, which overlaps with the mat body 101 at a first length and protrudes from the lateral edge of the mat body 101 at a second length, and is capable of being flexibly deformed so as to move away from the surface of the mat body 101. In FIG. 5, the portion of the flexible deformation portion 116 that overlaps with the mat body 101 is shown as an overlapping portion 116a, and the portion of the flexible deformation portion 116 that protrudes from the edge of the mat body 101 is shown as a protruding portion 116b. As shown by the imaginary line in FIG. 5, the flexible deformation portion 116 is capable of being deformed so as to rise from the mat body 101 and form a gap between the mat body 101 surface and the connecting portion 115 on the inner lateral side of the flexible deformation portion 116, which serves as a fixed end. Preferably, the length of the flexible deformation portion 116 (the sum of the first length and the second length) can be set to 20 to 40 cm. In addition, the first length (overlap length) is greater than the second length (protruding length).

That is, the end of the flow velocity reduction material 110 can be deformed via the flexible deformation portion 116 so as to rise from the surface of the mat body 101 near the edge of the mat body 101. As a result, when multiple soil erosion prevention mats 100 are arranged adjacent to each other in the horizontal direction (as will be described later in FIG. 7 and FIG. 8), the adjacent flow velocity reduction materials 110, 110 can be arranged continuously without interruption in the contour line direction of the slope soil, and the edges of the adjacent mat bodies 101, 101 can be laid overlapping each other in the contour line direction. In particular, by inserting the flow velocity reduction material 110 of one soil erosion prevention mat 100 between the flow velocity reduction material 110 of the other soil erosion prevention mat 100 that has been flexibly deformed and the mat body 101, the adjacent flow velocity reduction materials 110, 110 can be arranged at the same level of the slope soil without interfering with each other.

Next, referring to Figures 6 to 9, a slope soil protection structure 10 in which a plurality of soil erosion prevention mats 100 of this embodiment are installed in a predetermined protection area of the slope soil G will be described. Figures 6 and 7 are schematic perspective views of the slope soil protection structure 10. Figures 8 and 9 are transverse and longitudinal cross-sectional views of the slope soil protection structure 10.

In the slope soil protection structure 10 of this embodiment, as shown in FIG. 6, multiple soil erosion prevention mats 100 are installed on the slope soil G so that the vertical direction of each soil erosion prevention mat 100 is aligned with the inclination direction of the slope soil G. Each soil erosion prevention mat 100 is fixed to the slope soil G by multiple anchor pins 107, 108. The anchor pins 107, 108 are driven in so as to penetrate the flow velocity reduction material 110 and the mat body 101. The first anchor pin 107 is located inside (base end side) of the flexible deformation portion 116 of the flow velocity reduction material 110, and this can also be a connecting portion that connects the flow velocity reduction material 110 and the mat body 101. On the other hand, the second anchor pin 108 is driven into the overlapping portion of adjacent soil erosion prevention mats 100, 100 (i.e., the mat bodies 101, 101 and the flow velocity reduction materials 110, 110) and functions to strengthen the connection between adjacent soil erosion prevention mats 100, 100.

In addition, in the slope soil protection structure 10 of this embodiment, adjacent soil erosion prevention mats 100 are laid so that the edges of the mat bodies 101 overlap each other, covering the slope soil G so that it is not exposed. In other words, the multiple mat bodies 101 cover the slope soil G without interruption, thereby providing a soil runoff reduction effect over the entire protected area of the slope soil G. In addition, in the soil erosion prevention mats 100 adjacent in the contour direction, multiple flow velocity reduction materials 110 are continuously arranged in the contour direction of the slope soil G. In other words, the multiple flow velocity reduction materials 110 are continuously arranged in the contour direction of the slope soil G, providing a flow velocity reduction effect over the entire protected area of the slope soil G.

7 and 8, the flow velocity reduction materials 110, 110 adjacent in the horizontal direction overlap each other in the horizontal direction and are arranged continuously on the same level of the contour line. More specifically, in a state where the adjacent mat bodies 101, 101 are overlapped, one of the flow velocity reduction materials 110 is deformed so as to float upward, and the other flow velocity reduction material 110 is inserted into the gap between the one flow velocity reduction material 110 and the mat body 101. The flow velocity reduction material 110 can be deformed with the connecting part 115 or the first anchor pin 107 as a fixed end or fulcrum. In addition, since the length of the overlapping part 116a of the flexible deformation part 116 is greater than the length of the protruding part 116b, the overlapping width between the mat bodies 101, 101 is sufficiently secured. Then, one flow velocity reduction material 110 is stacked on the other flow velocity reduction material 110, and a dam that is continuous in the contour line direction is formed. At this time, the filler 112 moves and deforms inside the bag 111 of the adjacent flow reduction materials 110, 110, which prevents the flow reduction materials 110, 110 from overlapping like sandbags and forming large gaps between the flow reduction materials 110, 110. Furthermore, the second anchor pin 108 as a fixing member is finally driven into the slope soil G through the overlapping parts of the flow reduction materials 110, 110 and the mat main bodies 101, 101, so that the shape of the slope soil protection structure 10 is stably maintained.

As shown in FIG. 9, the cotton-like sheet 102 of the mat body 101 is in close contact with the surface of the slope soil G to protect the soil, and the flow velocity reduction material 110 attached to the surface of the mat body 101 forms a dam with a predetermined height in the vertical direction from the surface of the mat body 101. Here, in FIG. 9, the surface water flowing on the slope soil G is indicated by an arrow. As shown in FIG. 9, when surface water is generated by heavy rain, the flow velocity reduction material 110 functions to dam the water on the upper side in the inclination direction. The flow velocity reduction material 110 restricts the surface water from passing through at its original flow rate. That is, part of the surface water passes through the inside of the flow velocity reduction material 110, and part of the surface water accumulates on the upper side of the inclination direction of the flow velocity reduction material 110, crosses the top of the flow velocity reduction material 110, and flows down the inclination direction. In addition, part of the surface water is also drained by the cotton-like sheet 102 of the mat body 101. In this way, the surface water is dispersed by the flow velocity reduction material 110 and the cotton-like sheet 102, effectively reducing its flow velocity.

As shown in FIG. 9, the flow-reduction material 110 is connected to the mat body 101 via the connecting portion 115 of the connecting portion 114, and the bag body 111 is movable relative to the connecting portion 114. In other words, even if the flow-reduction material 110 is subjected to a force and moves, the bag body 111 tilts or moves relative to the connecting portion 114, thereby preventing a pulling force from being directly applied to the mat body 101. This effectively prevents the mat body 101 from floating up from the surface of the slope soil G or from being torn.

In this embodiment, the slope soil G is shown as an ideal slope with a single gradient, but it goes without saying that multiple soil erosion prevention mats 100 may be applied to natural terrain with complex gradients. In such cases, the flow velocity reduction materials 110 of adjacent soil erosion prevention mats 100 may be arranged so as to be bent in a V shape or to intersect with each other, thereby preventing adjacent flow velocity reduction materials 110 from being disconnected.

Next, a method for constructing a slope soil protection structure 10 by installing multiple soil erosion prevention mats 100 in a specified protection area of the slope soil G will be described. First, a specified number of soil erosion prevention mats 100 are prepared according to the area of the specified protection area. Multiple soil erosion prevention mats 100 are installed on the slope soil G so that the vertical direction of the soil erosion prevention mats 100 is along the slope direction of the slope soil G. The flow velocity reduction materials 110 of the soil erosion prevention mats 100 adjacent in the horizontal direction are aligned so as to be continuous at the same level without interruption in the contour line direction of the slope soil G, and the edges of the mat bodies 101 of the soil erosion prevention mats 100 adjacent in both the vertical and horizontal directions are aligned so as to overlap each other. Then, each soil erosion prevention mat 100 is fixed to the slope soil G by driving anchor pins 107 and 108. In other words, according to this method, by aligning and placing multiple soil erosion prevention mats 100 on the slope soil G, it is possible to construct a slope soil protection structure 10 that has the effect of reducing the flow rate of surface water and the effect of reducing soil runoff, making it possible to protect the slope soil G more easily and efficiently than the conventional log reinforcement construction method.

Based on the above, we will now explain the effects of the soil erosion prevention mat 100 of one embodiment of the present invention.

According to the soil erosion prevention mat 100 of this embodiment, the flexible mat body 101 covers the slope soil G, thereby reducing the runoff of soil and sand. In addition, the long cylindrical flow rate reducing material 110 extending across the entire lateral direction of the mat body 101 is attached to the surface of the mat body 101 to form a dam with a predetermined height vertically from the surface of the mat body 101, and the surface water flow rate reducing effect can also be achieved without creating any interruptions in the mat body 101. Therefore, the soil erosion prevention mat 100 of this embodiment is capable of covering the protected area of the slope soil G without interruption while reducing the flow rate of the surface water. Furthermore, the soil erosion prevention mat 100 of this embodiment can reduce the flow rate of surface water similarly to log reinforcement work by attaching the flow rate reducing material 110 to the surface of the mat body 101, and can improve the effort required to protect the slope soil G compared to the conventional method.

[Modification]
The present invention is not limited to the above-described embodiment, and various modifications are possible. Modifications of the present invention will be described below. In each modification, components indicated by three digits that have the same last two digits have the same or similar characteristics unless otherwise specified, and the description thereof will be omitted.

(1) The soil erosion prevention mat of the present invention is not limited to the above embodiment and can take various forms. That is, in the above embodiment, the flow velocity reduction material is attached to the surface of the mat body with the back side of the connection portion as the connecting portion, but the present invention is not limited to this. Figures 10(a) and (b) show soil erosion prevention mats 200 and 300 of modified examples. In the soil erosion prevention mat 200 shown in Figure 10(a), the connection portion is omitted, and the connecting portion 215 between the flow velocity reduction material 210 and the surface of the mat body 201 is formed in a straight line in the longitudinal direction of the flow velocity reduction material 210. This connecting portion 215 may be formed by means of adhesive or heat fusion. In the soil erosion prevention mat 300 shown in Figure 10(b), the connecting portion 315 between the flow velocity reduction material 310 and the surface of the mat body 301 is formed in a dot shape in the longitudinal direction of the flow velocity reduction material 210. This connection 315 may be a C-ring, staple, adhesive, or an anchor pin that penetrates the mat body 301 and the flow velocity reduction material 310 and is driven into the ground.

In the soil erosion prevention mats 200, 300 shown in Figures 10(a) and (b), the connection parts 215, 315 between the flow velocity reduction materials 210, 310 and the mat main body 201, 301 are one point in the vertical width direction. When a vertical force is applied to the flow velocity reduction materials 210, 310, the flow velocity reduction materials 210, 310 move vertically with the connection parts 215, 315 as fulcrums. This prevents the mat main body 201, 301 from being pulled by the flow velocity reduction materials 210, 310 and lifting off the soil surface or tearing the mat main body 201, 301.

(2) The soil erosion prevention mat of the present invention is not limited to the above embodiment and may take various forms. The soil erosion prevention mat of the present invention may be configured to further include a greening material attached to the mat body. FIG. 11 shows a soil erosion prevention mat 400 including a vegetation bag 421 and a seed-bearing sheet 422 as greening materials. The soil erosion prevention mat 400 includes a flexible mat body 401 configured to reduce erosion of the soil surface, and a plurality of flow velocity reduction materials 410 attached to the surface of the mat body 401 for reducing the flow velocity of running water flowing over the surface of the sloping soil. In this embodiment, the mat body 401 is configured to receive the vegetation bag 421 and the seed-bearing sheet 422.

Specifically, the mat body 401 includes a cotton-like sheet 402 of a predetermined thickness, a mesh sheet 403 attached to the front side of the cotton-like sheet 402, and a seed-bearing sheet 422 attached to the back side of the cotton-like sheet 402. As shown in FIG. 12, the mesh sheet 403 has a plurality of locations where the mesh body is doubled, and a plurality of storage sections 403a extending in a long cylindrical shape in the horizontal direction are provided at the locations. The storage section 403a is composed of a mesh-like long cylindrical body and is configured to hold a vegetation bag 421 containing a greening material. The greening material is a vegetation material used for greening, and includes at least one of seeds, fertilizer, soil improvement material, water retention material, water repellency suppression material, soil, and growth base material. Each storage section 403a extends longitudinally across the horizontal direction of the mat body 401. The seed-bearing sheet 422 is a nonwoven fabric sheet on whose surface plant seeds are scattered. In other words, by placing the soil erosion prevention mat 400 on sloping soil, it is possible to reduce erosion of the slope soil while simultaneously promoting soil greening by plants.

(3) The soil erosion prevention mat of the present invention is not limited to the above embodiment and can take various forms. In the above embodiment, the mat body is a mesh sheet laminated onto a cotton-like sheet of a certain thickness, but any material that has the effect of reducing soil erosion can be selected. For example, the mat body may be formed only from a cotton-like sheet of a certain thickness. Alternatively, the mat body may be a relatively thick nonwoven fabric or urethane sheet.

(4) The soil erosion prevention mat of the present invention is not limited to the above embodiment and may take various forms. In the above embodiment, both ends of the flow velocity reduction material are configured to protrude from both edges of the mat body, but the present invention is not limited to this. For example, only one end of the flow velocity reduction material may be configured to protrude from both edges of the mat body. Alternatively, in cases where a single soil erosion prevention mat covers a protected area of slope soil, the end of the flow velocity reduction material does not need to protrude from the edge of the mat body.

(5) The soil erosion prevention mat of the present invention is not limited to the above embodiment, and may take various forms. In the above embodiment, the flow velocity reduction material is attached parallel to the lateral direction of the mat body, but the flow velocity reduction material only needs to extend across the entire lateral direction of the mat body, and may extend at an angle to the lateral direction. In addition, the flow velocity reduction material does not have to be a single long cylinder, and may be composed of an assembly of multiple bags connected in the lateral direction.

The present invention is not limited to the above-mentioned embodiments, but may be implemented in various forms within the scope of the present invention.

10 Slope soil protection structure 100 Erosion prevention mat 101 Mat body 102 Cotton-like sheet 103 Net-like sheet 107 First anchor pin (connecting part)
108 Second anchor pin (fixing member)
110 Flow velocity reduction material 111 Bag body 112 Filler material 113 Net material 114 Connection space 115 Connection portion 116 Flexible deformation portion 116a Overlap portion 116b Protruding portion 421 Vegetation bag 422 Seed-bearing sheet G Slope soil (protected area)

Claims (11)

A soil erosion prevention mat that is installed on a slope soil to reduce soil erosion, comprising:
A flexible mat body extending lengthwise and widthwise, the lengthwise direction being arranged along the inclination direction of the slope soil, and configured to reduce erosion of the soil surface;
and one or more flow velocity reducing materials attached to the surface of the mat body for reducing the flow velocity of water flowing on the surface of the slope soil;
A soil erosion prevention mat characterized in that the flow velocity reduction material is formed in a long cylindrical shape extending across the entire lateral direction of the mat body and is configured to form a dam having a predetermined height vertically from the surface of the mat body. The soil erosion prevention mat according to claim 1, characterized in that the flow velocity reduction material comprises a bag body and a filler material containing granular material having a grain size or particle diameter of at least 10 mm or less, which is filled into the bag body. The soil erosion prevention mat according to claim 1, characterized in that the flow velocity reduction material comprises a bag body and a filler material containing at least wood chips, which is filled in the bag body. The soil erosion prevention mat according to claim 3, characterized in that the flow velocity reduction material is raised vertically from the surface of the mat body to a height of 5 to 13 cm. The soil erosion prevention mat according to claim 4, characterized in that the connection between the flow velocity reduction material and the surface of the mat body is formed in a straight line or in dots in the longitudinal direction of the flow velocity reduction material. The soil erosion prevention mat according to claim 4, characterized in that the flow velocity reduction material has a band-shaped connecting strip extending from the bag body in a width direction perpendicular to the longitudinal direction of the flow velocity reduction material, and the connecting strip is connected to the surface of the mat body with a surface extending parallel to the surface of the mat body as a connecting part. The soil erosion prevention mat according to claim 4, characterized in that the flow velocity reduction material has a flexible deformation portion at at least one end in the longitudinal direction, which overlaps with the mat body by a first length and protrudes from the lateral edge of the mat body by a second length, and is capable of being flexibly deformed so as to be separated from the surface of the mat body. The soil erosion prevention mat according to claim 4, characterized in that the mat body is formed from a cotton-like sheet of a predetermined thickness. The soil erosion prevention mat according to claim 4, further comprising a greening material attached to the mat body. A slope soil protection structure in which a plurality of soil erosion prevention mats according to any one of claims 1 to 9 are installed in a protection area of slope soil,
A slope soil protection structure characterized in that a plurality of flow velocity reduction materials are arranged continuously and uninterruptedly in the contour direction of the slope soil, and a plurality of mat bodies cover the soil surface of the protection area without exposing it. A method for protecting a slope soil to prevent soil erosion, comprising installing a plurality of soil erosion prevention mats according to any one of claims 1 to 9 in a protection area of the slope soil,
The flow velocity reducing materials of the soil erosion prevention mats adjacent in the horizontal direction are arranged so as to be continuous without interruption in the contour line direction of the slope soil,
A method comprising: arranging adjacent soil erosion control mats such that the edges of the mat bodies overlap each other.

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