JPS5819817B2 - Slope stabilization vegetation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for stabilizing slopes and also for greening slopes such as bedrock which cannot be greened and soft rocky surfaces where surface soil often flows out.

Conventionally, soft rock cut slopes, especially sedimentary soft rocks, are hard in dry conditions, but are susceptible to weathering when wet due to rainfall, etc., making it extremely difficult to carry out greening.

For slope greening, it is essential that the slope be stable and that there be a base layer for plant growth.

Various construction methods have been attempted for greening the above-mentioned sedimentary soft rock slopes, but successful examples are rare, and only a few methods are installed and connected by installing formwork on slopes that meet the essential requirements for greening. , a construction method in which low-slump mortar or concrete (hereinafter referred to as mortar, etc.) is sprayed into the formwork to reinforce the ground, and the formed structure is used as a base to provide a base layer for plant growth and greening. successful.

However, the above method had the following drawbacks.

(a) Since the formwork is formed on both sides, the rebound of low-slump mortar, etc. discharged into the frame cannot escape outside the formwork, and the mortar etc. is in a state similar to that of millet with many voids filled with rebound. In a short period of time, it has fallen into disrepair and weathered, and cannot be reinforced with mortar.

This means that even if the formwork is a wire mesh plate with large squares, the rebound that tries to escape outside the formwork will either hit the wire mesh plate and be bounced back, even if a small amount escapes at first. Gluing it to the board prevents the grid from forming, resulting in mortar that looks like millet.

At the same time, if conditions such as those found in millstones occur, air will enter, and the reinforcing bars installed within the lattice frame will oxidize and corrode, rendering them useless.

4. Formwork on both sides is not practical unless it has a shape that adapts to the unevenness of the slope, so special formwork must be made, and the formwork must be stretched vertically, so it requires advanced technology. It is not economical as it requires technology and is labor intensive.

In particular, many of the slopes to which this method is applied are made of rock, and the surface of rock slopes is often extremely uneven (some parts have reverse slopes), and most of the formwork on both sides is The formwork cannot be installed because parts of it are raised on the slope.

Furthermore, since it is impossible to eliminate such unevenness of the slope, it is practically impossible to implement this construction method.

C. If a base layer for plant growth is formed by spraying soil or organic materials for greening, when it rains, the only drainage measures available are spring water, and the slope surface is washed away. Rainwater accumulates at the bottom of the slope and washes away the base layer for plant growth.

In addition, even if the base layer for plant growth is formed by using a bag to prevent surface erosion, regardless of soil or spraying, the bag will fall apart in a short period of time, and even if the plants grow thick, the roots will grow.
Since it is about the same level as cIIL, it will be washed away by large amounts of rainwater.

The present invention was invented mainly in view of the above-mentioned drawbacks of Iroha, with particular emphasis on drainage measures, and its purpose is to provide a construction method that can stabilize slope surfaces and maintain the base layer for plant growth. It is in.

Slope 3 to explain the structure of the present invention by giving examples below.
1, a wire mesh 1 having a ratio of around 56 rn is stretched over the entire surface, and one place at intervals of 1 to 3 m is φ9mvtJ + length 30cI.
Fixed with IL Laspin 2, width 10crrL on the shoulder part
A groove 32 with a depth of about 30 cIIL is excavated, a wire mesh is wrapped in the groove, and an anchor 3 having a diameter of 16 mm and a length of 40 CrrL is driven and fixed.

If the slope is made of rock, a hole may be drilled and an anchor driven into the hole, or a rock bolt may be fitted into the hole and mortar may be filled in the hole to secure the slope.

Next, reinforcing bars 4 having a diameter of about 6 mm are arranged in a lattice pattern on a wire mesh to serve as markings and reinforcement at the portions where the bulges are to be formed in a lattice shape using mortar or the like, and are fixed with binding wires, wires, welding, or the like.

Once the above work is completed, spray low slump mortar or the like along the reinforcing bars to create a grid of 1 to 2 m sections with the bulges 5 having an upper end width of 20 cr IL, a lower end (slope adhesion part) width of 30 m, and a thickness of about 20 c IIL. form a frame.

In this case, it is preferable that the bulge 6 provided with the drainage portions A and B be larger in both width and height than the other bulges.

Further, the shape of the grid may be square, rectangular, trapezoidal, partially triangular, or a mixture of these shapes.

When a drainage portion is provided in a bulging body, there are two types of shapes: a U-shaped cross section as shown in A in FIG. 2, and an oval-shaped cross section as shown in B in FIG.

To make a mold for the shape of the drainage part, you can either spray mortar, etc. and make a mold by thickening or thinning it at the time, or you can spray mortar, etc. and then cut it out with a trowel etc. before it hardens and make a mold. good.

The size of the drainage part is 10 to 20 crn in width and 5 to 10 crn in depth.
crrL is normal, but it becomes larger at water collection point C.We have explained how to form a lattice frame using bulges and how to provide drainage parts, but next we will discuss how to arrange drainage parts on the slope. This will be explained step by step with some drawings.

FIG. 4 shows a case in which the drainage portion is provided with a slight inclination to the left, or to the right, or a combination of left and right drainage portions.

FIG. 5 shows a case in which drainage portions are provided diagonally across diamond-shaped lattice frames.

FIG. 6 shows a case where drainage sections are provided vertically and horizontally.

FIG. 7 is particularly suitable for slopes that are outwardly curved (convex at the center), and shows a case in which the drainage portion is provided at an angle to the left and right from the center line of the slope curve.

Figure 8 is particularly suitable for slopes that have an internal curve (concave in the center), with a vertical drainage section that serves as a water collection section in the center of the slope curve, and slopes from the left and right to the water collection section. The figure shows the case where a drainage section is provided.

Although typical examples of the methods of arranging the drainage portions of the present invention have been shown above, it goes without saying that there are various methods of arrangement by combining the above examples.

Also, in the drawings, drainage sections are provided for every three rows of lattice frames, but this can be changed in various ways depending on the local rainfall condition and gradient.

After the self-work is completed, the entire surface of the slope where the lattice frame has been formed, excluding the bulges and drainage areas, is covered with vegetation seeds suitable for the site, chemical fertilizers, park compost, organic fibers such as peat moss, etc.
Mix appropriate combinations of soil improvement materials, vegetation, and other vegetation base materials.
The plant growth base layer 7 is formed by spraying with a power sprayer to a layer slightly thinner than the thickness of the bulge.

Depending on the case, a film forming agent such as an asphalt emulsion may be sprayed or a net material such as a polyethylene net may be stretched.

The thickness of the vegetation growth base layer created by spraying this vegetation base material is approximately 10 cIIL, and since it is difficult for seeds located at the bottom to germinate, planting soil, organic fibers, compost, etc. After spraying vegetation base material such as chemical fertilizer,
In addition to the above-mentioned spraying method for forming a base layer for plant growth, greening methods that involve spraying seeds alone or in a mixture with the film-forming agent include placing vegetation bags or sandbags in a lattice frame. You may.

As described above, the present invention is for greening the inside of the lattice frame by forming the lattice frame and the drainage part by spraying mortar etc. after stretching the net-like body such as wire mesh on the slope, which has been difficult to green up until now. Slopes that were prone to collapse can be stabilized and revegetated.

The formed lattice frame is different from conventional cast-in-place lattice frames by removing the formwork on both sides, so the rebound caused by spraying mortar etc. does not accumulate inside the bulge and can clog the eyes. In this state, the reinforcing bars do not corrode, and the tensile strength of the wire mesh is combined to form a strong bulge.

In addition, the most important effect of the present invention is that in conventional cast-in-place lattice frames, drainage was only considered to be the treatment of spring water, but what is important is the treatment of surface water caused by rainfall, and in the present invention, the bulges are treated as appropriate. Because drainage sections are easily constructed at intervals, rainwater is collected without stagnation and drained to the bottom of the slope or to the left and right, preventing any runoff of the plant growth base layer.

Furthermore, as described above, the present invention does not require a special formwork, and a lattice frame can be easily formed by spraying mortar or the like on the base for stretching a net-like body such as a wire mesh or arranging reinforcing bars. However, in places with extremely uneven surfaces, it was impossible to use the conventional lattice frame forming method, which involves installing formwork and spraying low-slump mortar, etc., but the present invention makes it possible and stabilizes the slope in a short period of time. Once a greening base has appeared and plants have grown within the lattice frame, the net is stretched at the bottom of the lattice frame, so the roots can become entangled in the net, making it possible to plant even on steep slopes. It shows excellent effects such as there is no risk of animals falling.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the method for installing the mesh, and Figure 2 is a bulge forming a lattice frame, and after forming the bulge with a U-shaped drainage section, a base layer for plant growth is provided. A sectional view showing the location. FIG. 3 is a sectional view showing that the drainage section in FIG. 2 is L-shaped. FIGS. 4 to 8 are part of front views showing the method of arranging the drainage section. In the figure, 1 is a net-like body, 2 is a small lath pin, 3 is a large lath pin, 4 is a reinforcing bar, 5 is a bulge, 6 is a bulge with a drainage part, 7 is a plant growth base layer, 31 is a slope, Reference numeral 32 indicates a groove for winding up the wire mesh, A indicates a U-shaped drainage section, B indicates an L-shaped drainage section, and C indicates a large-sized drainage section.

Claims (1)

[Claims] 1. When forming a bulging body of mortar or concrete by stretching a net-like body such as a wire mesh on a slope and spraying mortar or concrete in a lattice pattern from above the net-like body, the bulging bodies are placed at appropriate intervals. A slope stabilizing vegetation construction method characterized by installing drainage areas and planting greenery within a lattice frame.