JP2007051514A - Long-sandbag drain reinforcing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing structure excellent in the drainage performance, strength and durability of a dam body or fill, and a long sandbag suitably usable for the formation of the reinforcing structure. <P>SOLUTION: In the structure for reinforcing the dam body or the fill, the long sandbag filled with an earth and stone material with favorable drainage performance is installed in the dam body or the fill in such a manner that one end of the long sandbag is positioned on the surface layer of a slope. In the use of the long sandbag which is filled with two or more kinds of earth and stone materials different in drainage performance in such a manner that layers are longitudinally divided from one another. The sandbag is installed in such a manner that the layer filled with the earth and stone material with high drainage performance is positioned on the side of the surface layer of the slope of the dam body or the fill, and that the layer filled with the earth and stone material with low drainage performance is positioned inside the dam body or the fill. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dam body or embankment reinforcement structure having good drainage, strength, durability, and the like, and a long sandbag that can be suitably used for forming the structure.

  A construction method is known in which a nonwoven fabric is laid in layers on a levee body or embankment for drainage and consolidation promotion in the levee body or embankment. In particular, it is known that a reinforcing structure having a high resistance to arc slip can be constructed by using a nonwoven fabric combined with high-strength fibers. However, when a nonwoven fabric is used, the drainage function may be significantly reduced due to clogging over time. Along with that, there was a problem that the reinforcing effect was lowered, the embankment was deformed, and the risk of collapse was increased.

  Therefore, an object of the present invention is to provide a reinforcing structure for a bank body or embankment that uses an inexpensive material, is easy to construct, has high strength, and can maintain good drainage over many years. . Another object of the present invention is to provide a long sandbag that can be suitably used to form such a reinforcing structure.

  That is, according to the present invention, a long sandbag filled with a debris material with good drainage is installed on the bank or embankment so that one end thereof is located on the slope surface layer part. Is provided. Long sandbags are generally installed so that they are almost horizontal in the longitudinal direction or inclined from the slope surface layer to the inside with a slope to improve resistance to slipping. The These can be installed by arranging a large number of them at intervals in the height direction and / or the width direction. Of course, if necessary, a large number of sandbags can be arranged in parallel and / or stacked so that the long sandbag occupies part or all of the slope portion. As the debris material filled in the long sandbag, a gravel material or crushed stone is preferably used.

  In such a reinforcing structure such as embankment, a long sandbag in which two or more kinds of soil materials having different drainage properties are filled in layers in the longitudinal direction as the long sandbag filled with a debris material with good drainage. Can be used. In this case, the long sandbag should be filled with a layer of debris material with high drainage on the slope surface side according to the location and purpose of use. It will be installed on the embankment and embankment.

  ADVANTAGE OF THE INVENTION According to this invention, the reinforcement structure of the embankment and embankment with which drainage property, drainage sustainability, and intensity | strength were improved can be formed by simple construction using an inexpensive material. That is, according to the present invention, since a long sandbag filled with a debris material with good drainage is installed, drainage inside the levee body and embankment is improved without causing clogging, and the entire dam body and embankment Can be strengthened. In particular, due to the restraint by the sandbag, the strength of the debris material-filled layer itself is strong, and the long sandbag provides a stiffening effect like a pile against the arc slip. Can be increased. In particular, when applied to embankments with low drainage, the effect of consolidation consolidation and reinforcement by drainage improvement is great.

  As a long sandbag filled with a debris material with good drainage, a long sandbag filled with two or more types of debris with different drainage properties in the longitudinal direction is filled with a highly drainable debris material. When installing on a bank, embankment, etc. so that the layer is on the slope surface side, the soil is highly safe against water infiltration, and the soil material with high drainage and the soil material with low drainage are separated into separate sandbags. Compared to the case of filling and arranging, the integrity of the slope is high and the strength is large, so the durability of the slope is excellent. Moreover, construction time can be shortened in slope formation. In addition, when applying a long sandbag filled with two or more types of debris materials with different drainage properties in the longitudinal direction to the downstream slope side of the dam body, it is a highly drainable debris When the material filling layer is installed on the inner side and the soil drainage material filling layer with low drainage is on the slope surface layer side, it is possible to prevent the intrusion of rainwater into the levee and lower the infiltration line in the dam.

  The long sandbag used in the present invention is a debris material with good drainage, filled in a long cylindrical bag material with excellent flexibility and water permeability, drainage performance, reinforcement effect, work In view of the properties, the influence range of the compaction effect, etc., a columnar or elliptical column shape having a length of about 1.5 to 10 m, a height of about 30 to 50 cm, and a width of about 30 to 100 cm is preferable. The weight of the sandbag filled with debris material should be determined according to the construction location, but considering the workability in the installation work, when using a backhoe, about 400-600 kg, when using a crane It is preferably about 600 to 3000 kg. Further, as the sandbag bag material, a material having water permeability and excellent water resistance and durability is preferable, and a polyolefin or polyester fiber such as polyethylene or polypropylene, or a woven fabric of tape is preferably used.

The long sandbag of the present invention is filled with a debris material with good drainage. The debris material with good drainage needs to have a particle size distribution with water permeability that does not cause piping, but a particle size distribution that prevents the trickle or embankment from flowing out is desirable. For example, in the soil particle size test based on JIS A1204, the 15% particle size of the above-mentioned debris material with good drainage is D _15f , the 50% particle size is D _50f, and the 15% particle size of the target embankment or embankment soil is D _It is preferable to use a debris material that satisfies D _15f / D _15b > 5 and D _50f / D _50b <25 when _15b and the 50% particle size is D _50b . More specifically, gravel materials, crushed stones, construction waste materials, etc. that are inexpensive and easily available can be mentioned, but in view of availability stability, the use of gravel materials or crushed stones is preferred.

  In the long sandbag of the present invention, it is not necessary to use the entire filling material as a debris material having good drainage, and a debris material having a drainage comparable to that of the levee soil and embankment material can be used in combination. . When two or more kinds of debris materials with different drainage are used in this way, generally, a debris material with good drainage and a debris material with relatively low drainage are divided into two layers in the longitudinal direction. Preferably it is used. In addition, when three or more types of debris materials with different drainage properties are divided into three or more layers, they are arranged in order from the highest drainage property, or vice versa, so as to give a gradient with respect to drainage properties. Filling is preferred. Examples of the debris material with good drainage include the above-mentioned gravel material, crushed stone, construction waste, and the like. Examples of the debris material with low drainage include clay, silt, and on-site excavated soil. Moreover, sandy materials such as mountain soil, river sand, and sea sand can be cited as intermediate debris materials for drainage. In any case, regarding the drainage as described above, when using a long sandbag that is layered and filled with debris material, in general, the filled layer of debris material with high drainage is positioned on the slope. However, if the effect as described above is expected, on the other hand, on the waterside slope of the levee, a packed bed of debris material with low drainage will be placed on the slope surface layer. You may install so that it may be located.

  Long sandbags are installed in the process of forming a bank or embankment, so that they are almost horizontal in the longitudinal direction of the sandbags, or are inclined to improve resistance to slipping. This is done by laying inward from the slope so that one end thereof is located on the surface of the downstream slope, and embedding on it. For the purpose of strengthening and reinforcing the drainage of ordinary levee bodies or embankments, considering the economic efficiency and reinforcement effect, long sandbags should be installed at regular intervals in the height and width directions. Preferably, the distance between adjacent sandbags can be, for example, about 1 to 2 m. Of course, it should be determined in consideration of the drainage of the bank and embankment, and even if the interval is larger than this, It may be small. Furthermore, in order to form a part or all of the slopes of the levee body and embankment at the ends of many long sandbags, the long sandbags can be arranged in parallel and / or stacked.

  In the reinforcing structure for embankment or embankment of the present invention, the geogrid can be laid at an arbitrary position between the upper and lower long sandbags in order to enhance the reinforcing effect. Further, as described above, when long sandbags are arranged in parallel and / or stacked, the geogrid can be laid so as to wrap around a plurality of long sandbags.

  FIG. 1 is a cross-sectional view showing an example of a long sandbag 1, in which a bottomed cylindrical bag material 2 is filled with a debris material 3 with good drainage and the opening end side is closed with a string. As described above, as a debris material with good drainage, any material may be used as long as it forms an appropriate gap when filled in a sandbag and does not clog by crushing. Granular natural stone, crushed stone, construction waste, etc. can be used.

  FIG. 2 is a schematic cross-sectional view showing an example in which such a long sandbag 1 is installed on the embankment 4, and FIG. 3 is a front view of a slope portion in FIG. 2, showing an arrangement state when the long sandbag is installed. ing. 2 and 3, the long sandbag 1 shown in the figure is formed by laying the long sandbag 1 on the embankment 4 formed on the foundation ground 5 at regular intervals in the course of embedding and embedding it on the embankment. 1 installation structure is formed. One end of the long sandbag 1 is exposed on the bank slope 6.

  FIG. 4 is a drawing schematically showing an example of a long sandbag in which two types of debris materials having different drainage properties are layered and filled in the longitudinal direction. In FIG. 4, a long sandbag 7 is made of a bottomed cylindrical bag material 8 made of a debris material having a relatively high drainage property, for example, a layer 9 filled with crushed stone, and a debris material having a relatively low drainage property, for example, clay. Two kinds of debris materials are filled so as to be separated into the filled layer 10. Although the filling ratio of both layers is arbitrary, it can be about 20 / 80-80 / 20 by volume ratio, for example. In order to obtain a desired filling ratio, a mark is put on the sandbag bag in advance, and after filling one of the debris materials, the other debris material may be filled.

  FIG. 5 shows that the long sandbag 7 of FIG. 4 forms a downstream slope on the opposite side of the dam body 11 from the water storage side 12 so that the layer 9 filled with highly drainable debris material is inside. It is a schematic diagram which shows the state piled up. The long sandbags 7 may be stacked so as to have a gentle slope or a steep slope, or may be stacked so as to form a vertical slope. By constructing a slope in such a structure, the slope is drained smoothly, and water penetration into the dam body due to rainfall or overflow is effectively suppressed. In addition, due to the restraint by the sandbag, different debris materials are integrated and the strength is increased, and a reinforcing effect such as a pile is exhibited against the arc slip along the slope, so that the safety of the entire levee body is enhanced.

It is drawing which shows an example of a long sandbag. It is a cross-sectional schematic diagram which shows the embankment structure which installed the long sandbag. It is a front view of the slope part in FIG. It is a schematic diagram which shows an example of the long sandbag filled with two types of debris materials from which drainage differs. It is a schematic diagram which shows an example which piled up the said long sandbag and formed the slope.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Long sandbag 2 Cylindrical bag material 3 Debris material 4 Embankment 5 Foundation ground 6 Embankment slope 7 Long sandbag 8 Cylindrical bag material 9 Packing layer of highly permeable debris material 10 Packing layer of debris material with low permeability 11 Embankment

Claims (6)

  A structure for reinforcing a bank body or embankment in which a long sandbag filled with a debris material with good drainage is installed on the bank body or embankment so that one end thereof is located on the slope surface layer.   2. A long sandbag filled with two or more kinds of soil and stone materials having different drainage properties in the longitudinal direction is used as the long sandbag filled with a debris material having good drainage. Reinforcement structure of dam body or embankment.   3. The dam body or embankment reinforcement structure according to claim 1 or 2, wherein the long sandbags are arranged with a space in the height direction and / or the width direction.   3. The levee body or embankment reinforcing structure according to claim 1 or 2, wherein the long sandbags are arranged in parallel and / or stacked so as to occupy part or all of the slope portion.   The dam body or embankment reinforcing structure according to any one of claims 1 to 4, wherein the debris material having good drainage is a gravel material or crushed stone.   A long sandbag in which two or more types of debris materials with different drainage properties are filled in layers in the longitudinal direction.

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