JPH0250255B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a slope protection method for preventing earth and sand from being washed away due to slope collapse or the like.

Conventional technology On slopes such as road cut-outs with relatively large inclination angles and insufficient soil strength, natural collapse and landslide due to wind and rain are unavoidable, and to prevent these, some form of earth retention is required. Countermeasures are necessary.

Conventional earth retention measures include constructing a lattice-like slope frame made of concrete, steel, wire mesh, plastic, etc. on the slope to be earth-retained;
One method is to install earth retaining fences in the form of steps on the slope. However, not only slopes that have only these earth retaining measures applied, but also slopes that have been newly created even if the slope angle is small, have no vegetation and therefore collapse at an extremely high rate when exposed to wind and rain. .

Therefore, a method of planting plants on slopes that are prone to collapse was considered, but carrying out earth retaining work and greening work separately required a lot of manpower, was inefficient, and was uneconomical. There was a drawback. In addition, methods have been considered to promote vegetation by spraying plant seeds, fertilizers, etc. together with water and fibers on such slopes, but although this spraying method is efficient, it does not affect the condition of the slope. In addition, newly created slopes generally have poor soil that is not suitable for plant growth and may wither, or the roots of plants that have finally sprouted may be buried in the soil. They were often blown away by the wind or washed away by the rain before they had fully penetrated. Furthermore, in order to improve the shortcomings of such conventional methods, a method has been proposed in which a soil-retaining greening sheet is pasted on a slope, with seeds and fertilizers of plants to be grown distributed and adhered to one surface. If the slope angle is large, large earth pressure will build up on the greening sheet that has been taken care of, unless sufficient soil retaining measures are taken separately.
There was a high risk that vegetation would not be able to form due to damage to the sheets, burying them with earth and sand, or washing them away.

Therefore, a method of forming sandbags using green sheets and installing them on the slope was proposed. Although these types of green sandbags have excellent effects in both earth retention and greening, they are not economical when installed on the entire slope due to high material and installation costs, and they are not economical when stacked high. There are construction issues,
It was often used in conjunction with simple earth retaining fences and piles to form earth retaining walls. In addition, on slopes with relatively gentle slopes, instead of constructing slope frames in a lattice pattern, low-height nets are stretched in a lattice pattern, and retaining sheets are attached to the mountain side to prevent soil flow. It has also been proposed that green sandbags be used in conjunction with construction methods to prevent soil damage.

In this type of net frame construction method, it is necessary to stack the green sandbags to the height of the net, and in order to prevent soil from flowing out from the gaps between the sandbags, materials and This method could not be called economical in terms of man-hours.

Problems to be Solved The present invention aims to propose an improved construction method that is easy to construct and has a reliable earth retaining effect in the netting frame construction method that protects slopes using sandbags. The aim is to provide economical and easy-to-handle sandbags for use in this construction method.

Means for Solving the Problems The object of the present invention as described above is to install a long mesh on the mountain side of a net installed on a slope that has water permeability, wet strength, and a mesh that allows plants to germinate. This can be achieved by installing a sandbag made by filling a bag body with earth and sand, etc., and having a sheet part formed by vertically sewing or joining sheets and capable of being extended and deployed on both sides. Particularly, effective earth retention can be achieved by deploying one of the sheet portions over the top of the net to the valley side and deploying and fixing the other sheet portion onto the mountain side slope.

In addition to the seeds and fertilizers for vegetation, the sandbag sheets also contain soil conditioners, water retention agents, etc.
By at least partially using so-called greening sheets glued with materials effective for promoting greening, such as germination promoters, and by adding a mixture of vegetative plant seeds and vegetative base materials to a portion of soil, etc. By filling it instead, the slope protection effect will be even greater.

The sandbag of the present invention is made of a long sheet as shown in FIG.
As in the examples shown in b, c and d, a long bag body 1 having two sheet parts 2 and 2' is obtained by overlapping them in the longitudinal direction and sewing or joining them using thread, In addition, as shown in Figure 1, soil, etc.
It is made by filling. The sheet used here is obtained by coarsely weaving vegetable fibers, synthetic resin fibers, etc., has a texture for plant germination, has water permeability, and has wet strength. . In addition, when using a part of this sheet to which seeds of plants for vegetation, fertilizer, etc. are adhered, the part that is the outside of the sandbag, the part that is exposed on the slope, or the part that is shallowly covered with soil. It is preferable that the structure is configured such that it occupies . The sandbag A thus obtained has sheet parts 2, 2' on both sides of the bag body 1.
It is of the form that is equipped with.

In order to construct a slope protection frame using the sandbags of the present invention, as shown in FIG. They are installed in series, and furthermore, piles, supports 4, etc. are driven into key points to form a continuous frame as a whole. At this time, when using a diamond-shaped net as the net 5, cross beams for fixing may be provided connected to the upper and lower parts of the pillars 4, etc., and the net 5 may be attached to these. Also, when using a grid-like welded net, it is possible to omit the crossbeams, and the frame can be fixed to the slope by providing long vertical striations of the welded net in the form of skewers and piercing them into the slope. Increase strength,
While it is possible to save on the number of piles and the like used, the provision of many small holes on the slope promotes the infiltration of rainwater and has the effect of encouraging the rooting and growth of vegetation. The mesh body 5 is not limited to these, and any suitable material may be selected and used, such as one made of woven wood, bamboo, or the like.

Next, a sandbag A and, if necessary, a vegetation sheet are installed in contact with the mountain side of the net frame thus installed. The length of the sandbag A may be arbitrary, but it is desirable to adjust it in advance so that it is approximately equal to the length corresponding to the two sides of the frame. It is preferable that the soil 3 to be filled into the sandbag A is separately formulated for plant growth, but it may also be soil generated locally, and it is best to mix leaf mold, fertilizer, etc. with the soil to promote vegetation. It is more preferable for It is also preferable to fill the soil with a mixture of vegetation seeds, fertilizer, etc. in a vegetation base material such as permiculite, in place of part of the earth and sand. When installing the sandbag A, the sandbag A may be filled with earth and sand 3 and placed close to the mountain side of the frame, or the sandbag A may be installed while being filled with earth and sand.
When installing, place one sheet part 2 at the bottom and the other sheet part 2' at the top, for example, on the mountain side of the frame so that the sandbag A is bent in a V-shape from the center. The lower sheet part 2 is spread out on the slope X on the mountain side, and the vicinity of the end is fixed to the slope with a small skewer or the like, or by placing earth and sand 6 or the like on it. When loading earth and sand, it is preferable to support the lower half of the sandbag with the earth and sand (Figure 4).

Furthermore, the upper sheet portion 2' extends over the net body 5 and extends to the valley side thereof. This helps to prevent the sandbags from separating from the frame of the mesh body 5 and shifting toward the mountain side or falling down. At this time, if fertilizer 7 or the like formed into blocks is attached to key points of the sheet portion 2', the work of expanding the sheet portion 2' will be facilitated, and it will be more effective for long-term growth of vegetation. Further, when the upper sheet portion 2' is sufficiently long, it may be made to wrap around the net body 5 and may also be expanded on the valley side slope. In some cases, instead of being fixed to the net, the vicinity of the end may be fixed to the valley side slope using a small skewer or the like. After installing the sandbags in this manner, it is more preferable to apply a mound of soil to the slope X as necessary, and further spread a seed-bearing vegetation sheet or the like.

When constructing a slope protection frame using the sandbag of the present invention, the height of the net to be initially installed is preferably about 10 to 30 cm. If the height is too low, the layer of soil necessary for plant growth will be thin, and it will be easily buried by soil washed away by rain, etc. On the other hand, if it is too high, the sandbag will only sit unstable. Moreover, the amount of earth and sand filled in the frame increases, which increases the amount of work and is uneconomical. Also, if the sandbag is too thick, it will be heavy and difficult to work with.
If it is too small, the slope protection effect will not be sufficient.
It is best to choose an appropriate height so that the height of the sandbags when installed is approximately 15 to 25 cm.

With the slope protection frame constructed using the construction method of the present invention, even if the earth and sand flows out due to rain, the earth and sand will settle within the frame of each unit and only the rainwater will permeate through the sandbags, sheets, etc. , or only rainwater overflows. Therefore, concentration of rainwater flow channels is less likely to occur in frames constructed by combining beam-like frames, etc.
There is little erosion of the slope. Furthermore, when the sandbag is made of a sheet with seeds of plants for vegetation, fertilizer, etc. adhered to it, it is more advantageous for the early establishment of vegetation in combination with the stability of the slope surface.

Effects of the Invention The slope protection method of the present invention uses long sandbags that are easy to handle and have uniform water permeability, so the amount of materials used and the number of construction steps are reduced, and the method has good corrosion resistance. It is an economical and excellent construction method because it allows the construction of a surface protection frame, has good drainage, and prevents the built-up earth and sand from eroding and flowing out.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a slope protection sandbag of the present invention, and FIG. 2 is an explanatory diagram of the structure of the bag. FIG. 3 is a perspective view of a slope protection frame constructed by the slope protection method of the present invention, and FIG. 4 is a sectional view of the frame portion. A... Sandbag, 1... Bag body, 2, 2'... Sheet part,
3...filling earth and sand, 4...post, 5...net body, 6...earth and sand,
7...Lump fertilizer, X...Slope.

Claims (1)

[Claims] 1. A slope protection frame or slope protection fence is formed by installing a net on a slope, and then sandbags are installed in contact with the mountain side of the net to protect the slope. In this regard, the sandbag is formed by vertically sewing or joining long sheets that are water permeable, have wet strength, and have a mesh that allows plants to germinate, and is equipped with a sheet portion that can be extended and deployed on both sides. A method characterized by using a body filled with earth and sand, etc., and deploying one of the sheet parts over the top of the net to the valley side, and deploying and fixing the other sheet part on the mountain side. Surface protection method. 2 Sediment, etc. is poured into a bag body that is formed by vertically sewing or joining long sheets that are permeable, wet-strength, and have a mesh that allows plants to germinate, and that has a sheet section that can be extended and deployed on both sides. A protective sandbag made by filling. 3. The sandbag according to claim 2, wherein the sheet has seeds of vegetation and fertilizer adhered thereto. 4. A sandbag according to claim 2, which is filled with a mixture of dry vegetation base material and seeds of vegetation plants as part or all of the earth and sand.