JP7183817B2 - Embankment reinforcement structure - Google Patents

Description

The present invention relates to a reinforcement structure for a bank body.

In recent years, there have been many breaches of river levees and reservoir levees due to large-scale earthquakes, and since several large-scale earthquakes are expected to occur, seismic reinforcement of levees is becoming increasingly important. .

In view of this background, techniques for reinforcing embankments (embankment bodies) using steel sheet piles have been proposed (for example, see Patent Documents 1 and 2).
In the seismic performance reinforcing structure of the embankment described in Patent Document 1, reinforcing plate-like bodies formed of steel sheet piles in two rows and columns in the longitudinal direction of the almost central part of the embankment such as an earthfill dam or a reservoir are installed. A double coffer structure is formed in which the upper ends of both reinforcing plates are connected by a connecting member at predetermined intervals.

In addition, in the embankment reinforcement structure described in Patent Document 2, a steel wall formed of steel sheet piles continuous in the extension direction of the embankment near the shoulder on the outer side of the embankment and whose lower end reaches the support layer of the ground. is provided, and in the vicinity of the slope shoulder on the inner side of the embankment, discretely arranged anchorages are provided, and the steel wall and the anchorage are connected to each other by a tie material near the crest of the embankment. .

JP-A-2003-321826 JP 2013-14962 A

By the way, "Trans. of JSIDRE No.218, Journal of the Japan Society of Agricultural
127-137 (2002.4), ``Causes of Destruction of Agricultural Ponds by Heavy Rain and Characteristics of Damage'', it is said that there are about 200,000 to 250,000 agricultural reservoirs nationwide. It is a valuable water resource not only for agriculture but also for the region. However, there are many ponds because they were built long ago and have deteriorated, and there are concerns about damage to the ponds during heavy rains. Damage to reservoirs includes damage to the embankment due to slips and erosion, leakage of water from the embankment and foundation, and damage to incidental structures. It's becoming
Due to recent heavy rain/earthquake disasters, damage caused by the collapse of dams of reservoirs has occurred nationwide, and there are more than 200,000 to 250,000 locations scattered throughout the country, so reinforcement of dams has become an urgent issue. ing.
As a levee reinforcement construction method using steel sheet piles, the steel sheet pile double cofferdam construction method has already been established, and has been adopted as a permanent structure for coastal levees. On the other hand, since a fixed amount of water is constantly stored in the irrigation levee (bank body) for agricultural purposes, it is necessary to take countermeasures that take into consideration the unbalanced water pressure on the levee body, which always acts.

In the conventional embankment reinforcement structures described in Patent Document 1 and Patent Literature 2 described above, the embankment (embankment body) is regarded as a linearly elongated uniform structure, and the extension direction (extending direction) of the embankment is perpendicular to the extension direction (extending direction) of the embankment. It is mainly to apply a reinforcement construction method that devises the arrangement of reinforcing bodies on a two-dimensional cross section, or to install reinforcing structures discretely within the range inside the extension direction of the embankment body as a linear structure. there were.
However, if a structure is installed only inside the embankment to resist the water pressure generated in the event of a disaster, etc., the reinforcing structure becomes large, which increases the construction cost and construction period.
In addition, the ends of the reinforcing body in the extension (extending) direction of the embankment are not connected, and the reinforcing body becomes large because it resists the soil bearing pressure received from the direction perpendicular to the side surface as a single wall body, In this respect as well, construction costs and construction periods increase.
In addition, when the surrounding ground is composed of relatively soft strata such as Saraike, it is necessary to drive a steel wall into the support layer in order to ensure the rigidity of the embankment so that it can resist water pressure. Construction period will be longer.

The present invention has been made in view of the above-mentioned circumstances, and is capable of shortening the construction cost and construction period compared to the conventional method, and resisting the increase in the water pressure acting on the bank when the amount of water stored in the saucer increases. An object of the present invention is to provide a levee body reinforcement structure capable of suppressing the collapse of the levee body.

In order to achieve the above object, the embankment reinforcement structure of the present invention is a embankment reinforcement structure for reinforcing the embankment of a saucer pond surrounded by a soil structure including at least the embankment,
A steel wall is continuously installed so as to surround the plate pond, and at least a part of the steel wall is installed inside the bank.

Here, "a soil structure including at least the embankment body" refers to a soil structure formed only by the embankment body or a soil structure formed by both the embankment body and a protruding part such as natural ground. means.
In addition, "the steel wall is continuously installed so as to surround the perimeter of the saucer pond" means that the steel wall is continuously installed along the saucer pond so as to surround the saucer pond. When the pond has a shape that bites inward in a plan view, the steel wall is not installed along the biting portion, and the steel wall is installed along the outer peripheral side of the biting portion. This includes
Moreover, as the steel wall, a steel sheet pile wall formed by connecting a plurality of steel sheet piles is suitably used, but it is not limited to this. For example, a steel pipe sheet pile wall formed by connecting a plurality of steel pipe sheet piles, a steel wall formed by connecting a plurality of steel sheet piles and steel pipe sheet piles, or the like may be used.

In the present invention, the steel wall is continuously installed so as to surround the pond, and at least a part of the steel wall is installed inside the bank body. It will be connected all around including the inside of . Therefore, when the water pressure acting on the levee body increases when the amount of water stored in the saucer pond increases, the levee body begins to collapse locally. By receiving resistance from the ground on the steel wall portions located on both sides, it is possible to resist an increase in water pressure, thereby avoiding local collapse of the embankment body 10 .
In addition, when the bank of the saucer pond is formed in a ring shape that does not bite inward in plan view, the steel wall installed inside the bank is also formed in a ring shape that does not bite inward. For this reason, the hoop tension of the steel wall formed in the ring shape can resist the above-described water pressure, so there is no need to impart great rigidity to the steel wall, and the steel wall can be installed inside the support layer, which is difficult to construct. There is no need to set up to Therefore, the construction cost and construction period can be shortened compared to the conventional method.

Further, in the above configuration of the present invention, the steel wall is formed in a ring shape that does not bite inward in plan view,
The steel wall installed inside the embankment has an upper end at the same height as the crest of the embankment, and is rooted to the upper surface of the support layer or bedrock layer located below the embankment. may be included.

Here, when the steel wall is embedded up to the upper surface of the bearing layer or bedrock layer, if there is a soft layer directly below the embankment and there is a bearing layer or bedrock layer directly below it, the steel wall is It means that the lower end of the steel wall is in contact with or close to the upper surface of the support layer or bedrock layer while penetrating the soft layer. means that the lower end of the steel wall installed inside the is in contact with or close to the upper surface of the support layer or bedrock layer.

According to this configuration, the upper end of the steel wall is at the same height as the crest of the levee body, and the steel wall is embedded up to the upper surface of the support layer or bedrock layer located below the levee body. Therefore, it is possible to prevent the occurrence of a water path penetrating the bank from the saucer pond side and a water path penetrating the weak layer directly under the bank body from the saucer pond side, so that seepage failure of the bank body can be suppressed.
In addition, when driving (embedding) a steel wall into the support layer or bedrock layer, a special construction machine such as a crush piler that crushes the ground is required. By stopping, construction can be performed with a normal construction machine, and construction costs can be suppressed.

Moreover, the said structure of this invention WHEREIN: The said steel wall may be formed by connecting multiple straight steel sheet piles.

According to this configuration, since hoop tension is used, the steel wall is not a retaining wall that resists out-of-plane bending, but a cell structure that resists in-plane tensile loads. , the bending rigidity of the steel wall installed inside the embankment can be made smaller than the conventional structure. Therefore, the steel wall can be formed from the straight steel sheet piles, and the material cost can be reduced.

Further, in the configuration of the present invention, the steel wall is formed in an irregular ring shape that bites inward in a plan view,
The steel wall may be embedded in a support layer or bedrock underlying the dam.

According to such a configuration, the steel wall is embedded in the support layer or bedrock located below the bank, so that the steel wall can be more strongly stabilized inside the bank.

Further, in the configuration of the present invention, a structure extending in the width direction of the bank is provided inside the bank, and a part of the lower end of the steel wall does not reach the structure. good too.

Here, the structure provided inside the embankment includes a bottom gutter, but is not limited to this.
In addition, when the steel wall is composed of a steel sheet pile wall, the lower end of the steel sheet pile positioned above the structure among the plurality of steel sheet piles constituting the steel sheet pile wall reaches the structure. It doesn't have to be.

According to such a configuration, it is possible to prevent the steel wall installed inside the bank from interfering with the structure inside the bank and damaging the structure.

According to the present invention, construction cost and construction period can be shortened compared to the conventional art, and collapse of the bank body can be suppressed by resisting the increase in water pressure acting on the bank body when the amount of water stored in the saucer increases.

BRIEF DESCRIPTION OF THE DRAWINGS The reinforcement structure of the embankment body which concerns on 1st Embodiment of this invention is shown, (a) is the schematic which shows typically, (b) is a top view which shows a modification. It is a cross-sectional view of the cut-off wall and the ground of the same. It is a perspective view of a steel sheet pile wall equally. It is sectional drawing along the extension direction of the steel sheet pile wall installed in the inside of a bank body equally. It is the schematic which shows typically the reinforcement structure of the bank body which concerns on 2nd Embodiment of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows the reinforcement structure of the embankment body according to the first embodiment, (a) is a schematic diagram schematically showing, (b) is a plan view showing a modification, and FIG. 2 shows the embankment body and the ground. is a cross-sectional view of the.
In this embodiment, as shown in FIG. 1(a), a soil structure 10A is formed only by the bank body 10. As shown in FIG. The soil structure 10A is basically a structure mainly made of soil, and includes various facilities and articles made of concrete or the like provided inside or on the surface thereof.

The bank body 10 is formed in a ring shape, specifically an elliptical ring shape, which does not bite inward when viewed from above. Note that the bank body 10 is not limited to an elliptical ring shape in a plan view, and may be formed in a circular ring shape, an oval ring shape, or the like, for example. The point is that it should be formed in a ring shape that does not bite into the inside.
The soil structure 10A may be formed of only the embankment 10 or, as shown in FIG. In this case, the bank 10d does not have a continuous ring shape and is partially formed by the projection 10e. It is formed in a continuous ring shape.

The dam 10 or the soil structure 10A surrounds an elliptical pond 11 in plan view.
As shown in FIGS. 1A and 2, the bank 10 has a trapezoidal cross section and is arranged in an elliptical ring shape in a plan view so as to surround the pond 11 .
Further, there is a soft layer 30 directly below the embankment body 10, and a support layer 40 or a bedrock layer is directly below the soft layer 30. - 特許庁The soft layer 30 and the support layer 40 are continuous below the pond 11 as well.
In the present embodiment, the embankment body 10 is provided on the upper surface of the soft layer 30 .

Further, if the side (inner side) of the bank 10 is defined as the upstream side and the downstream side is defined as the outer side of the crest 10a of the bank 10, the upstream side of the dam body 10 is the tray 11 in which water is stored. In addition, the bank body 10 has an upstream slope 10b on the upstream side and a downstream slope 10c on the downstream side across the crest 10a. The inclination angles of the upstream slope 10b and the downstream slope 10c with respect to the ground surface (upper surface of the soft layer 30) are equal, but the inclination angles may be different between the upstream slope 10b and the downstream slope 10c.

As shown in FIG. 2, water is always stored in the plate pond 11, and the water surface at the full water level is approximately half or more than the height of the upstream slope 10b of the bank body 10, In addition, the height of the embankment body 10 is set so that the water surface at the design flood level during heavy rain or the like is 1 m or more lower than the crest 10a according to the height of the waves and the water depth.
When the water level is always full, no water pressure acts on the upstream slope 10b above it from the saucer pond 11 side. That is, the water pressure acting on the bank body 10 gradually increases when the water surface always exceeds the full water level, and becomes maximum when the water surface reaches the design flood level due to heavy rain or the like.

Moreover, the bank body 10 is provided with a water intake facility (not shown). This water intake facility has a sloping gutter or hard gutter for taking in the water stored in the saucer pond 11 and a bottom gutter (see FIG. 4) for conveying the water. In general, a water intake hole is provided in a slanting pipe buried along the upstream slope 10b of the embankment body 10, and the water taken in from this hole is led to a bottom gutter buried at the bottom of the embankment body 10 to take the water. be done.

Inside the bank 10, a steel sheet pile wall (steel wall) 15 is continuously installed in the shape of an elliptical ring in plan view along the extending direction (longitudinal direction) of the bank 10. As shown in FIG. That is, the steel sheet pile wall 15 is continuously installed so as to surround the plate pond 11 .
Furthermore, the steel sheet pile wall 15 is installed in the center in the width direction of the bank 10, its upper end is at the same height as the crown 10a of the bank 10, and is embedded up to the upper surface of the support layer 40. ing. That is, the steel sheet pile wall 15 vertically penetrates the weak layer 30 and the lower end of the steel sheet pile wall 15 is in contact with or close to the upper surface of the support layer 40 . However, the installation position of the steel sheet pile wall 15 in the width direction of the bank body is not limited to the central portion, and the steel sheet pile wall 15 is installed near the shoulder of the slope on the side of the saucer pond or near the shoulder of the slope opposite to the saucer pond 11. You may By installing the steel sheet pile wall 15 at a position where the distance from the top end 10a of the bank body 10 to the upper surface of the support layer 40 is the shortest, such as when the upper surface of the support layer 40 is inclined, the upper and lower sides of the steel sheet pile wall 15 The length in the direction can be shortened, making it economical.

Further, as shown in FIG. 1(b), when the soil structure 10A is formed by both the embankment body 10d and the projecting portion 10e that constitutes a part of the ground or the like, the steel sheet pile wall 15 is formed by the embankment body It is installed inside the bank body 10 along the extending direction of 10d, and is not installed inside the projecting portion 10e at the portion of the projecting portion 10e, and the projecting portion 10e is inside (Saraike 11 side) are installed to avoid However, the steel sheet pile wall 15 is continuously installed so as to surround the circumference of the plate pond 11, and at least a part of the steel sheet pile wall 15, that is, the part excluding the part installed avoiding the protrusion 10e is a bank body 10d inside. In addition, when the projecting portion 10e is not hard but relatively weak, the steel sheet pile wall 15 may be installed inside the projecting portion 10e.

The steel sheet pile wall 15 is formed by connecting a plurality of hat-shaped steel sheet piles 16, as shown in FIG.
The steel sheet pile 16 includes a web 16a, flanges 16b formed at both ends of the web 16a, and an arm 16c formed at the end of the flange 16b opposite to the web 16a. A joint 16d is formed in the portion.
Adjacent steel sheet piles 16, 16 are connected by fitting joints 16d, 16d to each other, whereby a steel sheet pile wall 15 is formed.
The steel sheet piles forming the steel sheet pile wall 15 are not limited to hat-shaped steel sheet piles, and may be U-shaped steel sheet piles or straight steel sheet piles.

If there is no part of the pond 11 that encroaches inwardly along the outer circumference line, especially if it has a substantially circular shape, the fact that the water pressure acts evenly on a plane according to Pascal's principle can be used. , the hoop tension of the steel sheet pile wall 15 enables it to resist water pressure. Since the hoop tension is used, the steel sheet pile wall 15 is not a retaining wall that resists bending out of plane, but a cell structure that resists in-plane tensile loads. The bending rigidity of the sheet pile wall 15 can be made smaller than that of the conventional structure. Therefore, when using hoop tension, it is preferable to form the steel sheet pile wall 15 by applying a straight steel sheet pile, that is, by connecting a plurality of straight steel sheet piles. When constructing the steel sheet pile wall 15 with straight steel sheet piles, in order to enable installation of the straight steel sheet piles in the ground, there is an opportunity when constructing a saucer pond or when excavating the embankment for repair work of the saucer pond 11. use.

Further, as shown in FIG. 4, a structure 25 such as a bottom gutter extending in the width direction perpendicular to the extending direction of the bank 10 (the direction perpendicular to the paper surface in FIG. 4) is provided at the bottom of the bank 10. is provided, part of the lower end of the steel sheet pile wall 15 does not reach the structure 25 . In addition, the water taken in from the water intake hole is led to the slanted sluice pipe buried along the upstream slope 10b of the embankment body 10 and taken into the bottom gutter.
Since the steel sheet pile wall 15 is formed by connecting a plurality of steel sheet piles 16, the lower end portion of the steel sheet pile 16 positioned above the structure 25 among the plurality of steel sheet piles 16 reaches the structure 25. not, that is, a predetermined gap is provided between the lower end of the steel sheet pile 16 and the structure 25 .

As described above, according to the present embodiment, the steel sheet pile wall 15 is continuously installed so as to surround the plate pond 11, and at least a part of the steel sheet pile wall 15 is installed inside the bank body 10. Therefore, the steel sheet pile wall 15 is connected all around including the inside of the bank body 10 . Therefore, when the amount of water stored in the plate pond 11 increases during heavy rain or the like, the increase in the water pressure acting on the levee body 10 causes the levee body 10 to start collapsing locally. The parts of the steel sheet pile walls 15 located on both sides in the circumferential direction of the part of the bank 10 (the uneven shape in a plan view) receive resistance from the ground, so that local collapse of the bank 10 can be avoided. By leaving the sheet pile wall 15, the bank body height can be maintained.

In a plan view, the bank 10 of the dish pond 11 is formed in a ring shape that does not bite inward, and the steel sheet pile wall 15 installed inside the bank 10 is also formed in a ring shape that does not bite inward. . Therefore, since the hoop tension of the steel sheet pile wall 15 formed in the ring shape can resist the above-mentioned water pressure, it is not necessary to impart great rigidity to the steel sheet pile wall 15, and the construction of the steel sheet pile wall 15 is difficult. It is not necessary to drive the inside of the support layer 40 . Therefore, the construction cost and construction period can be shortened compared to the conventional method.

Further, since the upper end of the steel sheet pile wall 15 is at the same height position as the top end 10a of the bank body 10, and the steel sheet pile wall 15 is embedded up to the upper surface of the support layer 40 located below the bank body 10. Since generation of a water path penetrating the embankment body 10 from the dish pond 11 side and a water path penetrating the soft layer 30 directly under the embankment body 10 from the dish pond 11 side can be prevented, seepage failure of the embankment body 10 can be suppressed.
Furthermore, when driving (embedding) the steel sheet pile wall 15 to the support layer 40, a special construction machine such as a crush piler that crushes the ground is required. As a result, it is possible to carry out construction with a normal construction machine, and it is possible to suppress construction costs.
In addition, since hoop tension is used in the present embodiment, the steel sheet pile wall 15 is not a retaining wall that resists out-of-plane bending, but a cell structure that resists in-plane tensile loads. Therefore, the bending rigidity of the steel sheet pile wall 15 installed inside the bank body 10 can be made smaller than that of the conventional structure. Therefore, the steel sheet pile wall 15 can be formed of straight steel sheet piles, and the material cost can be reduced.

Further, when a structure 25 such as a bottom gutter extending in the width direction of the bank body 10 is provided inside the bank body 10, among the plurality of steel sheet piles 16 constituting the steel sheet pile wall 15, the structure 25 Since the lower end of the steel sheet pile 16 positioned above does not reach the structure 25, the steel sheet pile wall 15 can be prevented from interfering with the structure 25 and damaging the structure 25.

In the present embodiment, only one row of the steel sheet pile wall 15 is provided in the central portion of the bank body 10 in the width direction. Two or more rows may be provided at predetermined intervals in the width direction of the . In this case, it is preferable to connect the steel sheet pile walls adjacent to each other in the width direction of the bank body 10 by connecting members such as tie rods.

(Second embodiment)
FIG. 5 is a schematic diagram schematically showing a reinforcement structure for a bank body according to a second embodiment.
The second embodiment differs from the above-described first embodiment in that, in a plan view, the plate 11 is formed in an irregular ring shape that bites inward, and accordingly the steel sheet pile wall 15 is irregularly shaped in that it bites inward. , and the steel sheet pile wall 15 is embedded in the support layer 40 located below the embankment 10. Therefore, this point will be described below, and the first embodiment will be described. Parts common to the form may be denoted by the same reference numerals, and description thereof may be omitted.

As shown in FIG. 5, in the present embodiment, the dish pond 11 is formed in an irregular ring shape that bites inward in plan view. Specifically, the dish pond 11 is formed such that about 1/4 of the elliptical circumferential direction is greatly cut inward when viewed in plan, and in this cut-in portion, the dam body 10 is 2 inches in plan view. It is formed in two straight lines. Therefore, in a plan view, the bank body 10 is composed of a curved portion 10K and two straight portions 10L, 10L formed in a substantially 3/4 elliptical ring shape.

Steel sheet pile walls 15 are continuously installed so as to surround such a dish pond 11 , and these steel sheet pile walls 15 are installed inside the embankment body 10 . In addition, the steel sheet pile walls 15 are provided in two rows with a predetermined interval in the width direction of the bank body 10 . The two rows of steel sheet pile walls 15, 15 are driven from above inside the shoulder of the crest 10a of the bank body 10. As shown in FIG. The steel sheet pile wall 15 penetrates the weak layer 30 located below the bank body 10 and is embedded in the support layer 40 located below the weak layer 30 . That is, the lower end of the steel sheet pile wall 15 is driven into the support layer 40 by a predetermined depth from the upper surface of the support layer 40 .
Further, the upper ends of the two rows of steel sheet pile walls 15, 15 are connected by a plurality of connecting members 18 such as tie rods provided at predetermined intervals in the extending direction of the bank body 10. As shown in FIG.

In addition, in a plan view, in a portion where the bank body 10 is bent, a place with a large curvature, for example, a portion where the curved portion 10K and the straight portion 10L of the bank body 10 are connected, the steel sheet pile 16 that constitutes the steel sheet pile wall 15 By using a deformed steel sheet pile whose cross-sectional shape can be freely set as, the steel sheet pile wall 15 can be adapted to the planar shape of the bank body 10 .

According to the present embodiment, as in the first embodiment, the steel sheet pile wall 15 is continuously installed so as to surround the plate pond 11, and the steel sheet pile wall 15 is installed inside the bank body 10. Since it is installed, the steel sheet pile wall 15 is connected all around inside the bank body 10 . Therefore, when the amount of water stored in the plate pond 11 increases during heavy rain or the like, the increase in the water pressure acting on the levee body 10 causes the levee body 10 to start collapsing locally. The portions of the steel sheet pile walls 15 located on both sides in the circumferential direction of the bank body 10 (uneven portions in plan view) receive resistance from the ground, so that the adjacent steel sheet piles 16 that have begun to collapse collapse. , thereby avoiding local collapse of the bank body 10.
In addition, since the steel sheet pile wall 15 is embedded in the support layer 40 positioned below the bank 10 , the steel sheet pile wall 15 can be more firmly stabilized inside the bank 10 .

In this embodiment, the steel sheet pile walls 15 are provided in two rows with a predetermined interval in the width direction of the bank body 10, but more than that may be provided. The wall 15 may be provided in only one row at the central portion of the bank body 10 in the width direction.

Further, in the present embodiment, the steel sheet pile wall 15 is installed along the deformed ring-shaped bank body 10 inside the bank body 10, but as shown by the two-dot chain line in FIG. In the case of a shape that bites inward when viewed, the steel sheet pile wall 15 is not installed along this bitten portion, and the steel sheet pile wall 15 is formed along the outer peripheral side of the bitten portion so that it does not bite inward. A sheet pile wall 15 may be installed. In this case, as in the first embodiment, since the steel sheet pile wall 15 is formed in a ring shape, the hoop tension of the steel sheet pile wall 15 can resist the water pressure, thus imparting great rigidity to the steel sheet pile wall 15. There is no need to drive the steel sheet pile wall 15 into the support layer 40 which is difficult to construct. Therefore, the construction cost and construction period can be shortened compared to the conventional method. In addition, in the portion where the steel sheet pile wall 15 is not installed inside the bank body, which is the outer peripheral side of the biting portion, the top height of the steel sheet pile wall 15 is suppressed to the ground surface level, and the scenery of the surrounding environment is damaged. It is preferable to avoid In order to reinforce the embankment body 10 more firmly, the steel sheet pile wall 15 may be installed also in the part that bites inward.

10 bank body 10a crest 11 plate pond 15 steel sheet pile wall (steel wall)
25 structure 30 soft layer 40 support layer

Claims (6)

A bank body reinforcement structure for reinforcing the bank body of a saucer pond surrounded by a soil structure including at least the bank body,
A steel wall is installed so as to surround the circumference of the dish pond so as to be continuously connected on the entire circumference , and in a plan view, the entire steel wall is installed inside the bank body ,
A reinforcement structure for a bank body, wherein the steel wall is embedded up to an upper surface of a support layer or a bedrock layer positioned below the bank body . A bank body reinforcement structure for reinforcing the bank body of a saucer pond surrounded by a soil structure including at least the bank body,
A steel wall is installed so as to surround the circumference of the dish pond so as to be continuously connected on the entire circumference, and in a plan view, almost all of the steel wall is installed inside the bank body except for a part. ,
A reinforcement structure for a bank body, wherein the steel wall is embedded up to an upper surface of a support layer or a bedrock layer positioned below the bank body. In a plan view, the steel wall is formed into a ring shape that does not bite into the inside ,
3. A dam body reinforcement structure according to claim 1 , wherein said steel wall installed inside said dam body has an upper end at a height position equal to the crest of said dam body. The reinforcement structure for a bank body according to claim 3 , wherein the steel wall is formed by connecting a plurality of straight steel sheet piles. A bank body reinforcement structure for reinforcing the bank body of a saucer pond surrounded by a soil structure including at least the bank body,
In a plan view, the bank body is formed in an irregular ring shape that bites inward,
In a plan view, a steel wall is continuously installed inside the bank body other than the part that bites inward, and extends from the inside of the bank body to the outside of the part that bites inward. put out and arranged in a ring shape as a whole,
A reinforcement structure for a bank body, wherein the steel wall is not embedded in a support layer or a bedrock layer located below the bank body. A structure extending in the width direction of the bank is provided inside the bank,
The dam body reinforcement structure according to any one of claims 1 to 5 , wherein a part of the lower end of the steel wall does not reach the structure.

Images