JPS63176527A - Steep slope protection work by planting - Google Patents

Abstract

PURPOSE:To obtain a vegetation work on a horizontal step portion by preventing the degradation of slope by a method in which broken stone layers are continuously laid along slope by holding the tensile materials of the lowest banking layer from below and banking layers are formed on the front side in a tiered stepped manner. CONSTITUTION:Latticed or netted high-tensile materials 3 for civil construction work are set from the bottom side to the slope of a banking layer 2, and the innermost portion of the bottom of the materials 3 is joined with cross beams 4 covered with anchor blocks 5 and fixed to the backward slope by anchors 8. A broken stone layer 13 is laid below the materials 3 of the lowest banking layer 2, and a broken stone layer 11 is set between the materials 3 on the back of the layer 2 and the blocks 5. A grid skeleton 15 to hold slope on the front side of the layer 2 and a cloth material for preventing the run-off of soil are laminated to form a vegetation horizontal portion 18 by forming the fronts of upper and lower banking layers 2 in a tiered stepped manner for vegetation work.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to slope protection works for protecting steep slopes and cut-up slopes, and in particular to greening steep slopes by planting trees. It is.

<Conventional technology> Conventionally, as shown in FIGS. 6 to 11, timber 32 is stacked or concrete blocks 3 are stacked in front of embankment 31.
Crushed stones or earth and sand 35 that are piled up or put into cloth 34
Stacking gabions 36 filled with crushed stone, stacking concrete floor plates 37, and stacking concrete walls 38.
These are erected and held in place by high tensile strength civil engineering tensile strength materials 39 made of steel, polyethylene, or polypropylene in the form of belts, grids, or nets buried in the embankment 31.

In addition, as shown in Fig. 12, reinforcing cosicrete floors, l'K 41, are arranged in multiple stages in front of the steeply sloped ground 4o, and are anchored to the ground 4o using anchors 42. 40 and the floor plate 41, or as shown in FIG.
A construction method was also implemented in which 3 were added together and successively stacked on top of each other.

<Problems to be solved by the invention> The slope protection works shown in Figs. Collapse is prevented by overlaying the pull-out force of the tensile strength material that occurs when the material collapses. Therefore, this type of construction method does not have much effect on preventing collapse, so one width is long or the height is less than 10 m, which is too high.
It is used when it is desired to make the slope vertical or steep in order to make effective use of the top, but it is difficult to implement on steep slopes where the height is higher than the width, for example, several tens of meters. . In addition, greening has been impossible because the surface is made of materials that cannot grow plants, such as concrete, wood, and crushed stone wrapped in wire mesh.

The slope protection works shown in FIGS. 12 and 13 have greater resistance to collapse than those shown in FIGS. 6 to 11 and can be implemented on higher slopes. However, the surface is made of concrete, so it is similar in that it is impossible to grow plants.

Therefore, in construction work carried out by the national or local governments, the slope that is allowed for tree planting is limited to about 1:3, and greening cannot occur on slopes steeper than that.

<Means for Solving the Problems> The slope protection work according to the present invention is constructed by stacking a large number of embankment layers in order from the bottom in front of a steep mountain slope or cut-up slope. Sandwiched between the layers of the embankment is a lattice or net-like civil engineering strength member made of a high tensile strength material such as steel, polypropylene or polyethylene, the rear part of which extends along the slope. The tensile strength members are secured near the innermost part of the interlayer portion of the embankment or connected to the cross beams. The crossbeams are encased in anchor blocks made at appropriate intervals or entirely by cast-in-place concrete. A steel pile, or anchor, is driven through this anchor block into the slope behind it,
This allows the anchor block to be firmly fixed to the slope. From below the tensile strength materials laid under the lowest embankment layer, a layer of crushed stone is placed continuously along the slope with each tensile strength material in between. The embankment layer mentioned above is placed in front of this crushed stone layer.

The front face of the embankment layer is held in place by a strong vertical or steeply sloped lattice framework overlaid with a fabric-like material to prevent sediment runoff. The front of this embankment layer is arranged at different levels every two or several layers, and suitable trees are planted on the horizontal steps created by these different levels. Further, it is desirable to mix appropriate seeds in advance in the front part of each embankment layer that comes into contact with the cloth-like material.

<Function> Since the above-mentioned slope is vertical or has a steep slope in front of each embankment layer, it is possible to implement the slope as a whole up to about 70°. The stacked embankment layers are held on the slope behind each layer by tensile strength materials, and various expected failure surfaces will cross these tensile strength materials, so it is difficult to prevent the collapse of the embankment layers. It can be prevented. Furthermore, many anchors are driven into the ground slope and cut-up slope in the back, and the expected failure surface will also cross the anchors, which will help prevent the slope behind from collapsing. Therefore, it is possible to protect steep slopes such as those mentioned above, and it can be safely implemented even on slopes as high as several tens of meters.

In addition, since the embankment has a horizontal stepped portion consisting of a layer of embankment, trees can be planted therein, and since the front side of the embankment is covered with a fabric-like material, grass can be grown through the texture of the fabric. In this way, the entire slope can be covered with plants.

<Example> In Figures 1 and 2, ■ indicates a steep slope such as a rock cutting slope or a ground shaping surface, and 2.2... indicates a steep slope provided in front of steep slope 1 to protect it. It is an embankment layer. At the bottom of each embankment layer 2, grid-like or net-like tensile strength materials for civil engineering 3.3 made of M or synthetic resin are laid down at a gentle downward slope. As these tensile strength materials 3, a net-like material made of a braided material of synthetic resin fibers called geogrid is suitable;
It has a tensile strength of 0 tons. The rearmost part of the tensile strength member 3 is held down through a crossbeam 4 made of steel bar, as shown in FIG. The tensile strength member 3 further extends from the crossbeam 4 and is attached to the steep slope l.
It's climbing along.

5.5... is an anchor block made of reinforced concrete that is installed to enclose a part of the tensile strength member 3 and a part of the crossbeam 4. The anchor block 5 is reinforced with reinforcing bars 6 and has a through hole 7, as shown in FIG. A steel anchor 8 is deeply inserted into the steep slope 1 at the rear through the through hole 7, and by tightening a nut 9 screwed onto the end of the anchor 8, the anchor block 5 is firmly anchored to the steep slope 1. 10 is a cover that protects the end of the anchor 8 and the nut 9 from corrosion.

11, 11... are crushed stone layers for drainage piled up in front of the steep slope 1 with tensile strength material 3 in between, and between this and the embankment layer 2, there is a layer to prevent soil from flowing into the crushed stone layer ll. A geotextile cloth 12 with suitable openings is sandwiched in order to block the turbulence. 13 is a crushed stone layer for drainage laid under the lowermost embankment layer 2 and tensile strength material 3, and is continuous with the upper crushed stone layer 11, 11, etc. 14 is a drain pipe for draining water accumulated in the crushed stone layer I3.

Reference numeral 15 is a steel grid, and 16 is a civil engineering fiber cloth, which are laid on the lower front surface of the embankment layer 2, and are bent to stand up to protect the front surface of the embankment layer 2. As shown in FIG. 5, the lattice 15 is made of vertical bars 15a, 15a, φ, etc. of steel bars having a sufficient thickness, for example, 20 to 25 mm in diameter.
It is made by welding horizontal bars 15b, 15b, etc. of steel bars of appropriate thickness, and the mesh size is 20cm x 20cs.

In the illustrated embodiment, the embankment layers 2.2... have sloped front faces 17a, 17a... and vertical front faces 17b, 17b... Alternately stacked and inclined front surfaces 17a, 17a...
There are horizontal sections 18, 18, and 18 above each step.
are formed, and trees 19, 19, . . . are planted in the horizontal parts 18, 18, . . . , respectively. In addition, the front surfaces 17a, 17a... and 17b, 17b...
Grass seeds are mixed in the soil behind...
The germinated grass grows through the holes of the civil engineering fiber cloth 16.

In the embodiment described above, it is appropriate that the depth of each embankment layer 2, 2, . The front surface of each embankment layer 2.2... is configured in a dogleg shape by arranging the entire surface 17a inclined above the vertical front surface 17b as shown in the first diagram, and also has a steep front surface with the same slope. The horizontal part 18.18...
shall be provided for each appropriate number of embankment layers 2.2, etc. depending on the slope slope.

Anchors 8.8... It is appropriate to drive anchors 4 to 5 m long at horizontal intervals of about 2 m. Anchor blocks 5,5, etc. may be provided for each anchor 8 as shown in the figure, or may be provided continuously so as to enclose the entire crossbeam 4. In that case, the crushed stone layer 11 is provided for each anchor 8. Is it necessary to form it so as to cover the front surface of the block 5?

On the slope mentioned above, the plane 21, 22, 23, 24 shown in Fig. 1
, 25, 26, etc., but these surfaces intersect tensile strength members 3.3... one after another, so the failure will occur at tensile strength members 3.3... The collapse of the embankment can be prevented unless this occurs. In addition, the collapse of the ground at the ground level 27, 28, 29, and the area 30, 31
．． Even if slipping along 32 is predicted, these are connected to the later parts by anchors 8, 8, etc., so it is possible to prevent the collapse and slipping of the ground etc.

<Effects of the Invention> As is clear from the above-mentioned embodiments, the present invention prevents the collapse of a mountain slope or a cut-up slope, while also creating an embankment layer in front of the slope without fear of collapse. Can be stacked and covered. Therefore, it is possible to safely protect even extremely steep slopes such as 70", and in addition to this, it is possible to secure a horizontal crotch area for planting trees and the front of the soil slope where grass can grow. It is possible to green the entire slope.

[Brief explanation of the drawing]

Figures 1 to 5 show embodiments of the present invention, with Figure 1 being an overall vertical sectional view, Figure 2 being a detailed partially enlarged vertical sectional view, and Figure 3 showing how the tensile strength members and cross beams are connected. 4 is an enlarged vertical sectional view of the anchor block, FIG. 5 is a plan view of the tensile strength material and the lattice frame, FIGS. 6, 7, 8, 9, 1O, FIGS. 11, 12, and 13 are longitudinal sectional views of various conventional slope protection works. 1... Slope, 2... Embankment layer, 3... Tensile strength material for civil engineering, 4... Cross beam, 5... Anchor block, 8... Anchor, 11 and 13...crushed stone layer, 15...lattice framework, 16...fabric material, 1
8...Horizontal part.

Claims (1)

[Claims] (1) In slope protection works in which a large number of embankment layers are stacked sequentially from the bottom in front of a steep mountain slope or a cut-up slope, a high tensile strength lattice or A mesh-like tensile strength material for civil engineering is laid, the bottom of the tensile strength material is connected to the anchoring crossbeam at the bottom, an anchor block is formed from concrete by wrapping at least a portion of the crossbeam, and the anchor The block is fixed with a steel anchor driven into the slope behind it, and a crushed stone layer is laid below the above-mentioned tensile strength material in the lowest embankment layer, and behind each of the above-mentioned embankment layers, the above-mentioned A crushed stone layer that is continuous with the crushed stone layer is installed, and in front of each of the above embankment layers, a lattice-like frame strong enough to support vertical or steep slopes and a cloth-like material to prevent earth and sand from flowing out are superimposed, A steep slope tree-planting slope protection work in which the front surfaces of the upper and lower embankment layers are different from each other for each of the above-mentioned multiple embankment layers to form a horizontal section for planting trees.