JPH0453207B2 - - Google Patents

Description

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

<Prior art> Conventionally, as shown in FIGS. 6 to 11, wood 32, concrete blocks 33, or crushed stone or earth and sand 35 wrapped in cloth 34 are stacked on the front of an embankment 31. Stacking gabions 36 tied together with crushed stones, concrete floor plates 37
These can be stacked or concrete walls 38 erected, and these can be held down by high tensile strength civil engineering tensile strength materials 39 made of steel, polyethylene or polypropylene in the form of strips, grids or nets buried in the embankment 31. It is being said.

In addition, as shown in Fig. 12, the steep slope of the ground 4
Reinforced concrete floor plates 41 are arranged in multiple stages on the front surface of the ground 40, and are attached to the ground 40 using anchors 42.
Anchored at
As shown in Figure 13,
Inverted Y-shaped concrete block 44 in front of 0
A construction method was also implemented in which crushed stones 43 were placed behind the stones and piled up one after another.

<Problems to be solved by the invention> The slope protection structure shown in Figs. By exceeding the pull-out force of the tensile strength material that occurs when the material collapses,
It prevents collapse. Therefore, this type of structure does not have much of an effect on preventing collapse.
The width is long, but the height is less than 10m, so it cannot be made very high.
It is used when you want to make the slope vertical or steep in order to make effective use of the top, and it is difficult to implement on steep slopes that are higher than the width, for example, several tens of meters. It was hot. In addition, because the surface is made of materials that cannot grow plants, such as concrete, wood, crushed stone wrapped in metal, etc.,
Greening was impossible.

The slope protection structures 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 projects carried out by the national and local governments, the slope at which trees can be planted is limited to a slope of 1:3, and it is not possible to plant trees on steeper slopes.

<Means for Solving the Problems> The slope protection structure according to the present invention is constructed by stacking a large number of embankment layers sequentially from the bottom in front of a steep earth slope or cut slope. Sandwiched between the layers of the embankment is a lattice or net-like civil engineering tensile strength material 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 connected to the cross beams near the innermost part of the interlayer portion of the embankment and held there. The crossbeams are encased in anchor blocks made at appropriate intervals or entirely by cast-in-place concrete. A steel stake, or anchor, is driven through the anchor block into the slope behind it, thereby firmly fixing the anchor block 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 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 2
Each layer or several layers are arranged at different levels, and appropriate trees are planted on the horizontal steps created by the 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 front surface of each embankment layer is vertical or has a steep slope, the above-mentioned slope can be constructed up to an overall slope of 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, making it difficult to effectively prevent the collapse of the embankment layers. It can be prevented. Furthermore, many anchors are driven into the ground slope and cut 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 maintain a steep slope as described above, and it can be safely carried out even on a slope as high as several tens of meters.

Moreover, 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 cloth-like material, grass can be grown through the texture of the cloth. In this way, the entire slope can be covered with plants.

<Example> In Figures 1 and 2, 1 is a steep slope such as a rock cutting slope or a ground shaping surface, 2, 2... is an embankment layer provided in front of the steep slope 1 to protect it. It is. At the bottom of each embankment layer 2, grid-like or net-like civil engineering tensile strength materials 3, 3, . As these tensile strength members 3, a mesh material made of a braided material of synthetic resin fibers called diogrid is suitable, and this has a tensile strength of about 10 tons per 1 meter width. 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 climbs up along the steep slope 1.

Reference numerals 5, 5, . . . indicate anchor blocks made of reinforced concrete that enclose a portion of the tensile strength member 3 and a portion of the crossbeam 4. Anchor block 5 is the fourth
As shown in the figure, it is reinforced with reinforcing bars 6.
It has a through hole 7. A steel anchor 8 is deeply inserted into the steep slope 1 behind 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 the tensile strength material 3 in between, and between this and the embankment layer 2, there is a layer to block earth and sand from flowing into the crushed stone layer 11. In order to do this, a geotextile 12 having a suitable weave is sandwiched. 13 is a crushed stone layer for drainage laid under the lowest embankment layer 2 and tensile strength material 3, and the upper crushed stone layer 1
1, 11, etc. are consecutive. 14 is crushed stone layer 1
This is a drain pipe for draining water that has accumulated inside the tank.

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. The grid 15 has a diameter of, for example, 20 mm, as shown in FIG.
Horizontal bars 15b, 15b... of appropriate thickness are welded to longitudinal bars 15a, 15a... of steel bar with sufficient thickness of ~25 mm, and the mesh size is 20 cm x 20 cm. be.

In the illustrated embodiment, the embankment layers 2, 2... have sloped front surfaces 17a, 17a... and vertical front surfaces 17b, 17b... are stacked alternately. Front 17a, 17a...
Above... there are horizontal sections 18, 18...
... 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 ..., and the germinated grass grows through the holes of the civil engineering fiber cloth 16.

In the embodiment described above, each embankment layer 2, 2...
Appropriate depth is 2 to 4 m and height is 60 to 80 cm. 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 straight front surface with a steep slope and the same slope. It may be configured in the form of
The horizontal portions 18, 18... shall be provided for each appropriate number of embankment layers 2, 2... depending on the gradient of the slope.

It is appropriate for the anchors 8, 8, . . . to be 4 to 5 m long and driven at horizontal intervals of about 2 m. The anchor blocks 5, 5, . . . may be provided for each anchor 8 as shown in the figure, or they may be provided continuously so as to enclose the entire crossbeam 4. In that case, the crushed stone layer 11 is not connected to the anchor blocks. It is necessary to form it so as to cover the front surface of 5.

On the above-mentioned slope, the surfaces 21, 22, 2 shown in FIG.
Even if it is predicted that the embankment will collapse at points 3, 24, 25, 26, etc., these surfaces intersect tensile strength members 3, 3, etc. one after another, so tensile strength members 3, 3, etc.
As long as rupture does not occur in ..., collapse of the embankment can be prevented. In addition, the surface 27, 2 is
Even if collapse at points 8 and 29 or sliding along planes 30, 31, and 32 are expected, these are connected to the later parts by anchors 8, 8, etc., so the ground, etc. It can also prevent collapse and slippage.

<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 slope, and also forms an embankment layer in front of the slope without fear of collapse. Can be stacked and covered. Therefore, even extremely steep slopes, for example 70°, can be safely protected, and in addition, a horizontal stage for planting trees and a sandy front surface on which grass can grow can be ensured. , the entire slope can be greened.

[Brief explanation of the drawing]

1 to 5 show embodiments of this invention,
Fig. 1 is an overall longitudinal sectional view, Fig. 2 is a detailed partially enlarged longitudinal sectional view, Fig. 3 is a sketch showing how the tensile strength members and cross beams are connected, and Fig. 4 is an enlarged longitudinal sectional view of the anchor block. Figure 5 is a plan view of the tensile strength material and lattice frame, Figures 6, 7, 8, 9, and 10.
11, 12, and 13 are longitudinal sectional views of various conventional slope protection structures. 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 frame, 16...Fabric material, 18...Horizontal part.

Claims (1)

[Claims] 1 In front of a steep mountain slope or cut slope,
In a slope protection structure in which a large number of embankment layers are stacked in order from the bottom, a high tensile strength civil engineering tensile material in the form of a grid or net is laid from the bottom of each of the embankment layers to the slope, and the bottom of the tensile material is The innermost part is connected to a retaining crossbeam, an anchor block is formed from concrete surrounding at least a part of this crossbeam, and this anchor block is connected to a steel anchor driven into the slope behind it. A crushed stone layer is laid below the tensile strength material in the lowest embankment layer, and a crushed stone layer continuous to the crushed stone layer is installed between the tensile strength material and the back of each of the embankment layers. In front of the embankment layer, a lattice-like frame strong enough to hold vertical or steep slopes and cloth-like material to prevent soil outflow are installed in layers, and each of the upper and lower embankment layers A steep-slope tree-planting slope protection structure with a stepped front surface to form a horizontal section for planting trees.