JP4699655B2 - How to create steep banking - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for creating a steep bank that combines a large sandbag, improved soil, and geogrid.
[0002]
[Prior art]
In general, in the construction of a construction road with cut embankment in a mountainous area or the like, there is often a steep slope due to land limitations.
[0003]
On steep slopes, concrete retaining walls will be constructed to hold the slopes, or a reinforced earth method will be used. Reinforced earth construction methods use the tail armoring method, in which the precast concrete wall panel is integrated with the embankment by the friction resistance of the steel plate embankment material called strip, or the net-like reinforcement material called geogrid is used. However, a reinforced earth method is also implemented in which the slope portion is connected to a concrete panel or a steel net or a sandbag is wound to form a steep slope.
[0004]
As for the reinforced earth method, the present applicant has previously proposed a method in which improved soil and geogrid are combined as disclosed in JP-A-2001-123455.
[0005]
As a method of constructing a steep bank as a temporary structure, it is a common practice to pile up large sandbags.
[0006]
[Problems to be solved by the invention]
The concrete retaining wall described above requires an anti-foundation depending on the foundation ground, and as the embankment height increases, the structure becomes larger and the cost becomes very high. In this regard, although the tail arme method reduces the cost, there is a limit to the problem of connection with the reinforcing material when the wall panel is made thinner.
[0007]
Reinforced earth works using geogrids tend to be under-rolled by heavy machinery near the embankment concrete panel, causing uneven settlement, and stress concentration occurs at the joint between the concrete panel and geogrid. May break. In the type involving a sandbag, the exposed portion of the reinforcing material is likely to deteriorate, and the sloped surface has a flexible structure, which is problematic in terms of durability, and the steel net is inferior in cost advantage.
[0008]
On the other hand, the reinforced earth method using the combination of improved soil and geogrid proposed by the applicant has overcome these problems, but the outermost outer wall panel is some obstacle to further cost reduction. ing.
[0009]
When stacking large sandbags to form steep banking, depending on the height of the banking, it is necessary to arrange the sandbags in, for example, about 3 rows. There is a particular problem in road construction by embankment in mountainous areas where it is necessary to allow some margin from the shoulders, and there is a lot of waste in terms of space, and sufficient space cannot be secured.
[0010]
The present invention aims to solve such problems. That is, an object of the present invention is to provide a method for constructing a steep bank that is very inexpensive and excellent in workability, and is optimal for temporary use.
[0011]
[Means for Solving the Problems]
A first aspect of the present invention is stacked large sandbags as outermost wall, the inside thereof, modified soil walls corresponding to each stage of a large sandbags, and laying embankment on the inside, the surface of the modified soil wall plate compactor Ya In addition to rolling by the vibrating roller, the surface of the embankment is rolled, and a geogrid is laid so as to enter from the rolling surface of the embankment to about half of the rolling surface of the improved soil wall. It is characterized by constructing a gradient embankment .
[0012]
According to a second aspect of the present invention, in the first aspect of the present invention, the one-stage large sandbag is formed so as to sequentially correspond to an improved soil wall, embankment, and geogrid inside.
[0013]
Operation and effect of the invention
According to the present invention, the stability and strength of steep embankment is maintained by the improved soil wall and geogrid, and therefore using large sandbags as the protective wall part, material costs and construction costs can be significantly reduced. Is possible. In addition, large sandbags are required to have the function of formwork as an auxiliary material for compaction of improved soil walls during construction as well as to prevent erosion. Large sandbags are usually large cubes with 1 m ³ each. In addition, it can function sufficiently with its own weight alone, and there is an improved soil wall with sufficient self-supporting strength on the back of the large sandbag, and only the earth pressure during construction by the sandbag itself acts on the foundation of the large sandbag. It does not require special foundation work.
[0014]
In addition, by forming a layer of improved soil wall, embankment and geogrid for each step of the large sandbag, the large sandbag has the function of a formwork as a compacting auxiliary material when rolling the improved soil wall or embankment. Can be created efficiently.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0016]
FIG. 1 is a construction section of a road formed by using the steep slope embankment creation method of the present invention, and FIG. 2 is a diagram showing the procedure of the creation method.
[0017]
In FIG. 1, 1 is a large sandbag, 2 is an improved earth wall, 3 is a geogrid, 4 is embankment, 5 is a road surface, and 6 is a guide rail. Reference numeral 7 denotes a natural mountain line, and 8 denotes an excavation line.
[0018]
The large sandbag 1 is a cube of about 1 m in each piece, and the weight is about 2 t. The improved soil wall 2 is a hardened wall material mixed with soil, solidified material and short fibers. The soil uses locally generated soil at the construction site, the solidified material uses cement, and lime according to the soil quality. A system can also be used. As the short fiber, an elastic petrochemical fiber having a length of about 30 to 50 mm and a thickness of about 10 μm is used. In the case of sandy soil, the geogrid 3 uses a net-like one, and the fixed length of the geogrid 3 is at least about 1.0 m and is about half the wall width of the improved soil wall 2.
[0019]
The creation procedure will be described with reference to FIG.
[0020]
The natural ground is excavated as shown by the excavation line 8 in FIG. 1, and the large sandbag 1 is installed in a position corresponding to the outermost retaining wall. Next, an improved earth wall 2 is placed on the inner side of the large sandbag 1 at half the height, and an embankment 4 is placed on the back of the sandbag. The improved earth wall 2 and further the embankment 4 with a plate compactor or a vibrating roller , Each is compacted to a predetermined density. The geogrid 3 is laid on the rolling surface so as to enter about half of the width of the improved earth wall 2, and the improved earth wall 2 and the embankment 4 are spread again from above and rolled. Finish to the height of the first large sandbag 1.
[0021]
When the first stage is finished in this way, the second stage large sandbag 1 is stacked on the first stage large sandbag 1 with a crane or the like, and the improved soil wall 2 and the embankment 4 are placed on the inside by the same procedure as described above. And the geogrid 3 is spread in layers, and the second stage is finished. Thereafter, these procedures are repeated until the necessary height is reached.
[0022]
In addition, about the geogrid 3, it arrange | positions corresponding to each step | level of the large sandbag 1 in the ratio of one layer. Each number in the figure indicates the above-described creation procedure step by step, and means that creation work is performed in order from the smallest number.
[0023]
Finally, leaving the margin for making the outermost surface the road surface 5 inside the uppermost large sandbag 1, the laying of the improved soil wall 2 and the embankment 4 is finished, and the road surface 5 is formed with a predetermined pavement surface. Form and complete.
[0024]
In the present invention, since the improved earth wall 2 is formed on the wall surface, a large strength can be exhibited even by rolling with a blade compactor or a small vibration roller, and the stability of the wall surface is high. Moreover, the embankment 4 on the back side can all be rolled by heavy machinery, and a high-quality steep embankment can be constructed.
[0025]
The large sandbag 1 not only leads to cost reduction, but also has excellent workability because it is a flexible material. The function required for the large sandbag 1 is to prevent erosion and to serve as a compacting auxiliary material for the improved soil wall 2 during construction. Although the role of the frame is expected, each single unit of the large sandbag 1 is a large cube with each piece being 1 m, and can function sufficiently only with its own weight. And since there is an improved soil wall 2 with sufficient self-supporting strength on the back of the large sandbag 1, only the earth pressure at the time of construction of each stage acts on the large sandbag 1. No foundation work is required. Moreover, since the structural stability as a steep bank is provided by the improved soil wall 2 and the geogrid 3, the large sandbag 1 can be prevented from deteriorating if it plays a role as an erosion prevention or rolling compaction aid. No mortar spraying is required.
[0026]
The embankment material can be used up to viscous soil (liquid limit of 50% or less), and since it is treated stably, the locally generated soil can be used effectively.
[0027]
The present invention is not limited to the embodiments described above, and it is obvious that various modifications are possible within the scope of the technical idea of the invention described in the claims.
[Brief description of the drawings]
FIG. 1 is a construction cross section of a road formed by using the construction method of the present invention.
FIG. 2 is an explanatory diagram showing a procedure of a creation method of the present invention.
[Explanation of symbols]
1 Large sandbag 2 Improved soil wall 3 Geogrid 4 Embankment

Claims (2)

A large sandbag is piled up as the outermost wall, and the inside is laid with an improved earth wall corresponding to each step of the large sandbag, and embankment on the inside, and the surface of the improved earth wall is rolled by a plate compactor and a vibrating roller. , Rolling the surface of the embankment, laying a geogrid so as to enter from the rolling surface of the embankment to about half of the rolling surface of the improved soil wall , and sequentially forming these layers into a steep bank A steep slope embankment creation method characterized by   The steep slope embankment forming method according to claim 1, wherein the large sandbag is formed so as to correspond in sequence so that the improved soil wall, embankment, and geogrid are formed in one layer on one stage of the large sandbag.

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