JPH02128006A - Levee - Google Patents

Abstract

PURPOSE:To prevent an overall break of a levee in case of high waters by coating a subsoil layer of the levee constructed with earth with a non-permeable sheet lengthwise extending the full length thereof. CONSTITUTION:While tamping generally used earth for reclamation, fill is carried out, and a subsoil layer 8 with an angle shaped section is constructed along a river 1. After that, the surface of the subsoil layer 8 is coated with an in-permeable sheet 7 of polyvinyl chloride, and earth is also piled up thereon to construct a levee 2. Even if a part of the levee breaks in case of the rising of the river, the subsoil layer 8 coated with the in-permeable sheet 7 forms non-erosive wall to prevent an overall break of the levee. According to the constitution, clayey soil is not used for the subsoil layer 8, and a stronger levee can be economically constructed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to embankments constructed using earth and sand along rivers and coasts, and particularly to embankments that can prevent total collapse. .

[Prior Art] Embankments have conventionally been constructed along rivers and coasts to prevent floods caused by rising river water or high tides caused by typhoons, heavy rain, etc.

These embankments are generally constructed using earth and sand from excavation and dredging, but as shown in Figure 6, embankment 1a
A subsoil layer 2a is placed in the center of the subsoil in the lengthwise direction by compacting clay earth and sand into, for example, a semi-cylindrical shape to eliminate voids and make it impermeable, thereby preventing total collapse due to floods such as the river 38. are doing.

However, since the subsoil layer 2a is disposed along the entire length of the embankment 1a constructed along the river 3a, etc., a huge amount of clay is required. Clay with this quality and particle size is rare and difficult to obtain.

Therefore, levees are constructed using only general reclaimed soil without forming the subsoil layer 2a, and there is a problem in such levees that there is a risk of complete collapse.

[Problem to be solved by the invention] The present invention has been made to solve the problem,
To provide an embankment that is free from the risk of complete collapse without using special clay that is difficult to obtain.

[Means for Solving the Problems] In the present invention, a means for solving the above-mentioned problems is provided by a structure in which a subsoil layer covered with a water-impermeable sheet is arranged in the length direction.

[Operation] When a part of the embankment collapses due to a flood or high tide, the subsoil layer covered with an impermeable sheet acts as an inerodible wall to prevent the embankment from completely collapsing.

[Example] Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of the present invention constructed along a river 1, in which an embankment 2 having the same external shape as the conventional one has a roof 3 and slopes 4 and 5 on the front and back. , for example thickness 2
A sheet 7 formed by connecting a plurality of non-water permeable sheets 6 made of polyvinyl chloride with a width of ~10+u+ and a width of a few m in parallel in the length direction of the embankment 1 while overlapping their adjacent connecting edges. A subsoil layer 8 with a chevron-shaped cross section is disposed in the length direction of the embankment 2.

As shown in FIG. 2, the embankment 2 having such a configuration is first constructed by tamping and embanking the site where the embankment 2 is to be constructed, thereby forming a subsoil layer 8 having a mountain-shaped cross section. At this time, if necessary, steel sheet piles or reinforced concrete sheet piles 9 are driven. Then, the roof 3 and the front and back slopes 4 and 5 of the subsoil layer 8 are covered with a sheet 7, and further mounded earth and sand is tamped on top of this, and the surface is covered with grass or stones to form an embankment.

Even if a part of the embankment 2 with such a structure collapses due to an increase in the water of the river 1 due to a typhoon or heavy rain,
The subsoil layer 8, which has a mountain-shaped cross section and is covered with a water-impermeable sheet 7, serves as an inerodible wall and can prevent the embankment 1 from completely collapsing.

Further, FIG. 4 shows another embodiment of the present invention,
The overall structure is similar to that of the embodiment described above, but the sheet 7 is non-water permeable, including not only the top 3 and the front and back slopes 4 and 5 but also the bottom 9 of the subsoil layer 8 having a chevron-shaped cross section. The difference is that it is completely covered. Therefore, the subsoil layer 8 covered with the sheet 7 has no risk of collapsing from the bottom compared to the embodiment described above, exhibits better erosion resistance, and reliably prevents the embankment 2 from completely collapsing. .

This embankment 2 is constructed by first forming a moat 10 of a predetermined depth extending in the length direction of the embankment 2 approximately at the center of the planned construction site of the embankment 2, as shown in FIG. Build a subsoil layer 8 covered with At this time, 1, for example, a sheet body 7 having a sufficient length is spread on the bottom of the trench 10, earth and sand is poured onto it, and the soil is tamped and embanked into a predetermined mountain-shaped cross section to form a subsoil layer 8. Wrap the sheet body 7 around and cover it.
Next, in the same manner as in the previous embodiment, the earth and sand piled up on top of the pile are compacted and constructed.

Although the above embodiments have been described with respect to an embankment constructed along a riverbank, the present invention can be similarly implemented on an embankment constructed along a seashore or lakeshore, and similar effects can be obtained.

[Effects of the Invention] Since the embankment according to the present invention has a structure in which a subsoil layer covered with a non-permeable sheet is arranged in the length direction, the embankment may be damaged due to rising water in rivers or high tides. Even if a part of the building collapses, the subsoil layer covered with a water-impermeable sheet forms an impervious wall that prevents a complete collapse, so no major damage will occur. Furthermore, the soil used for the subsoil layer may be reclaimed soil that is generally used throughout the country and is generated by excavation or dredging, and is not only easily available and economically superior, but also does not pose any difficulty in embankment work.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, in which FIG. 1 is a partially cutaway perspective view, FIGS. 2 and 3 are explanatory diagrams showing the construction method, and FIG. FIG. 4 is a sectional view showing another embodiment of the present invention, FIG. 5 is an explanatory view showing its construction method, and FIG. 6 is a sectional view showing a conventional example. 2... Embankment, 7... Sheet, 8... Subsoil layer.

Claims (1)

[Claims] Subsoil layer (8) covered with a water-impermeable sheet (7)
An embankment characterized by being arranged in the length direction.