JPH0568565B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an easy-to-implement river embankment construction method that is highly safe against emergencies such as floods and can also contribute to the maintenance and management of waterside greening.

(Conventional technology) In normal times, river banks are built at the normal water level l shown in Figure 2.
The embankment body 10 is not immersed in water, but in the event of a flood, the water often reaches the flood water level L at the upper end, which is lined with concrete 11.

By the way, many of the old levees were built by filling soil from the vicinity of the site, and the levee body 1
0 itself is often made of permeable soil.

(Problems to be Solved by the Invention) Therefore, even if the river side is lined with concrete or the like, rainwater permeates and forms a saturated area within the embankment body 10, as shown in Figure 2. A so-called water leakage phenomenon occurred in which water gushed out onto the slope behind the embankment, causing soil to flow out and the embankment to be destroyed.

In addition, in the concrete 11 revetment on the slope side of the embankment, the distortion force of the concrete is smaller than that of the soil, so when the ground is distorted, concrete that cannot keep up with it will crack and lose its water-blocking properties. Moreover, this concrete cladding 11 looked too artificial and could not create an atmosphere where people could casually come to relax by the water. Therefore, the idea that future urban rivers should incorporate greenery into waterfront planning and appropriate vegetation to create a balance between nature and man-made water has recently become popular.

(Means for Solving the Problems) This invention has been made to solve the above problems. dozens of
The aim of the present invention is to apply the principle of creating an impermeable layer on the surface by flattening the surface, and to build a river embankment by combining an impermeable layer of clay and this functional stabilizing material.

In detail, this invention involves constructing a clay impermeable layer on at least the top slope side and the lever surface of the embankment body, and processing a water-absorbing resin into a fiber-like fiber on the surface of the clay impermeable layer with a specific gravity of 0.07. A river embankment construction method that is characterized by stretching felt pine-shaped water gel pine with a weight of ~0.15g/ ^cm3 , combining the two with anchors, and adding soil on top to grow plants on the surface. be.

Next, a construction example of the present invention will be explained in detail with reference to FIG.

First, embankment body 1 is built by embanking the soil near the site. Note that this material may be permeable soil,
It may be an existing embankment that has been constructed in the past.

When the river bed 2 is a permeable bed, water stop sheet piles 3 are driven on the river surface side to reach the impermeable layer to block foundation water leakage. Then, as shown in FIG. 1, clay is applied to the surface of the cutoff sheet pile 3 to the front side, the lever side, and the upper back side of the embankment body 1 to form a clay impermeable layer 4. In some cases, a waterproof sheet such as a rubber sheet may be interposed in the clay.

Then, on the upper surface of the clay water-permeable layer 4, a water gelling mat 5, which will be described later and which is a feature of the present invention, is spread.

This is because when starch is polymerized with acrylate grout, or carboxycellulose is grouted with acrylate, it absorbs several hundred times its volume of water and solidifies, creating a mass that does not allow the water to escape under pressure. It has the property of becoming a lumpy substance.

Processing this kind of water-absorbing resin into fiber cotton,
When the water-gelled mat 5 is processed into a felt mat shape and has a specific gravity of 0.07 to 0.15 g/cm ³ , water becomes solid plate-like and forms an impermeable layer. However, since the molecular structure of H ₂ O remains the same, although it dries,
Evaporation is very slow compared to ordinary fiber pine, and while polyester or polypropylene cotton pine of the same specific gravity dries in a room at 20°C and 60% humidity in about 24 hours, the water-gelled pine of this invention 5 takes 240 hours, or 10 days.

On the other hand, when clay contains water, it becomes sticky and is therefore impermeable to water, but when it dries, it shrinks, causing cracks and cracks. Therefore, in cases such as river embankments, water normally does not come in and the clay dries out, causing cracks and cracks in the clay, but if a flood occurs in a place with such cracks and cracks, this clay layer becomes a water barrier. It will not fulfill the role of the layer.

Therefore, in this invention, a water gelling mat 5 is pasted on the clay impermeable layer 4. Then, an anchor 9 penetrating the clay impermeable layer 4 is taken from the water gelling mat 5, and the clay impermeable layer 4 and the water gelling mat 5 are integrally combined.

Then, a covering soil 6 suitable for growing a lawn is added on top of this, and plants 7 are grown on the surface. Note that 8 is the pavement on the top of the tenba.

(Effects of the invention) In the embankment constructed using this invention, the surface of the embankment is impermeable by concrete or asphalt lining, and clay is buried as an impermeable layer within the embankment, and this clay is always kept moist without losing its viscosity. In other words, the water-gelling pine contained in the soil is
As mentioned above, it takes 10 days to dry even in a room, so it hardly ever dries out, keeping the clay constantly moist and protecting and maintaining its function as an impermeable layer.

In addition, if this water-gelling pine is not present, the water that has permeated the surface soil will move parallel to the clay surface at the boundary with the clay and move downward, causing slippage at this boundary and causing the soil to slip. The soil falls off and collapses. However, in this invention, the surface of the fibrous gelled mat retains the fluffy nature of the fibrous mat, so it has a large frictional force and good adhesion to the soil, so it works to prevent the soil from slipping. Furthermore, if the gelled water inside the mat is also water, the water that has penetrated is also water.
The bonding and adsorption of water ions work together to provide a feature that does not create a sharp boundary between flowing and sewage water. For this reason, there is an excellent effect that the top soil layer above the pine is highly unlikely to slide and break during floods.

This is the effect when a flood comes after the construction is completed, but when constructing the embankment with soil, the water-gelled pine is dry, but at this time the surface roughness of the pine is
At 0.6N to 0.7N (N is overburden load), soil has good adhesion and embankment construction with soil is easy.

In addition, since water-gelled pine is a fibrous pine, it has much higher tensile strength than soil, so if you set an anchor that penetrates the clay layer, you can avoid an unexpected accident in which the soil is washed away by the force of a flood. Even if it happens,
The levee below Matsuto is protected from soil washing away, and the levee does not break. Therefore, it is possible to construct a levee that prevents damage caused by floods.

In addition, the surface covering soil allows for greening with grass and plants, and there is no possibility of cracks and loss of water-blocking properties as with concrete-lined embankments, and the embankment is made of earth, making it safer. is high.

In addition, the pine acts as a heavy body corresponding to the thickness of the clay layer by anchoring, and the post-mortem management is the same as that of an earthen embankment, making it easy to manage. It's a huge amount.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing a conventional embankment. 1... Embankment body, 2... River bed, 3... Water stop sheet pile, 4
...Clay impermeable layer, 5...Water gelatinized pine, 6...
...soil, 7...plant, 8...paving, 9...anchor, 10...embankment, 11...concrete,
l...Water level during normal water, L...Water level during flood.

Claims (1)

[Claims] 1. A clay impermeable layer is applied to at least the surface of the embankment and the top of the embankment, and a water-absorbing resin is applied to the surface of the clay impermeable layer in the form of fibers to increase the specific gravity.
This river embankment construction method is characterized in that water gelatinized pine in the form of a felt pine of 0.07 to 0.15 g/cm ³ is stretched, both are combined with anchors, and plants are grown on the surface using top soil as additional soil.