JP2023145098A - embankment - Google Patents

Abstract

An object of the present invention is to improve the strength of an embankment reinforced with walls when water overflows through interaction between the walls and a structure installed at the top. [Solution] A first wall body is cast in a part of the embankment body on the water body side, a second wall body is cast in a part of the embankment body on the side opposite to the water body, and at least the first wall body is cast in a part of the embankment body on the side opposite to the water body. an impermeable structure installed in an area including above the second wall, and extending horizontally from the outermost edge of the second wall to the side opposite to the water area with an overhang length B of 300 mm or more; An embankment is provided. [Selection diagram] Figure 1

Description

The present invention relates to an embankment.

For river embankments, there are concerns about cracks and subsidence in the embankment bodies due to earthquakes, and breaches and collapses due to erosion of the embankment bodies due to overflow during rising waters. As a countermeasure against this, for example, Patent Document 1 discloses that steel sheet pile walls extending in the continuous direction of the embankment body are cast on the slope shoulders on both sides in the width direction of the embankment body, and the heads of each steel sheet pile wall are connected with tie rods. The reinforcement structure of the embankment is described. It is known that such a reinforced structure using double steel sheet pile walls is effective as a countermeasure against liquefaction because the two rows of steel sheet pile walls suppress soil deformation and movement during an earthquake.

Japanese Patent Application Publication No. 2003-13451

By the way, research is progressing on the reinforcing structure of embankments using double steel sheet pile walls as described above as a countermeasure against liquefaction during earthquakes, but it is difficult to improve the strength of embankments in the event of overflow or scouring caused by rising water. It cannot be said that sufficient proposals have been made regarding a rational structure for improving the performance. For example, the tops of many embankments are constructed as roads or promenades, so structures such as concrete pavement and floor slabs are installed on top of steel sheet pile walls, but these structures cannot be used when water overflows. The interaction with the wall has not been elucidated.

Therefore, the present invention aims to realize a structure in which the strength of the embankment is improved when water overflows through interaction between the wall and a structure installed at the top of the embankment reinforced using walls. purpose.

［３］上記張り出し長さＢは、堤高Ｈの関数ｆ（Ｈ）を含む式（ｉ）および式（iii）を満たす、［１］に記載の堤防。

［４］上記張り出し長さＢは、さらに、洗掘された領域の最も上記第２の壁体側の位置から上記第２の壁体までの距離である地盤残存長さＬをさらに含む式（iv）を満たす、［２］または［３］に記載の堤防。

［５］上記地盤残存長さＬは、係数βおよび受動崩壊角φを用いて式（ｖ）で定義される、［４］に記載の堤防。

［６］上記地盤残存長さＬは、係数βを用いて式（vi）で定義される、［４］に記載の堤防。

［７］上記不透水性の構造物は、上記堤体の天端面上に設置される天端構造物である、［１］から［６］のいずれか１項に記載の堤防。
［８］上記天端構造物は、舗装構造体である、［７］に記載の堤防。
［９］上記第１および第２の壁体の少なくともいずれかと、上記舗装構造体の不透水部分とは、止水部材で接続される、［８］に記載の堤防。
［１０］上記天端構造物は、頂版コンクリートである、［７］に記載の堤防。
［１１］上記不透水性の構造物は、上記第２の壁体から上記水域とは反対側に張り出す張り出し部材である、［１］から［６］のいずれか１項に記載の堤防。
［１２］上記第１および第２の壁体の少なくともいずれかは、鋼矢板壁である、［１］から［１１］のいずれか１項に記載の堤防。
［１３］堤体に打設される壁体と、少なくとも上記壁体の上方を含む領域に設置され、上記壁体から水域とは反対側に水平方向に３００ｍｍよりも大きい張り出し長さＢで張り出し、上面側に不透水性部分を含み、下面側に透水性部分を含む構造物と、上記壁体と上記不透水性部分とを接続する止水部材と
を備える堤防。 [1] A first wall cast in a portion of the embankment body on the water area side, a second wall cast in a part of the embankment body opposite to the water area, and at least the second wall body cast in a portion of the embankment body on the side opposite to the water area an impermeable structure installed in an area including above the wall and extending horizontally from the outermost edge of the second wall to the side opposite to the water area with an overhang length B greater than 300 mm; Embankment with
[2] The embankment according to [1], wherein the overhang length B satisfies equations (i) and (ii) including a function f(H) of the embankment height H.

[3] The embankment according to [1], wherein the overhang length B satisfies equations (i) and (iii) including a function f(H) of the embankment height H.

[4] The above-mentioned overhang length B is determined by the formula (iv ), the embankment according to [2] or [3].

[5] The embankment according to [4], wherein the ground remaining length L is defined by equation (v) using a coefficient β and a passive collapse angle φ.

[6] The embankment according to [4], wherein the ground remaining length L is defined by formula (vi) using a coefficient β.

[7] The embankment according to any one of [1] to [6], wherein the impermeable structure is a crown structure installed on the crown face of the embankment body.
[8] The embankment according to [7], wherein the crown structure is a pavement structure.
[9] The embankment according to [8], wherein at least one of the first and second walls and the impermeable portion of the pavement structure are connected by a water stop member.
[10] The embankment according to [7], wherein the crown structure is made of concrete.
[11] The embankment according to any one of [1] to [6], wherein the impermeable structure is an overhanging member that overhangs from the second wall body to a side opposite to the water body.
[12] The embankment according to any one of [1] to [11], wherein at least one of the first and second walls is a steel sheet pile wall.
[13] A wall to be cast on the embankment and a wall installed in an area including at least the upper part of the wall and extending horizontally from the wall to the side opposite to the water area with an overhang length B greater than 300 mm. An embankment comprising: a structure including an impermeable portion on the upper surface side and a water permeable portion on the lower surface side; and a water stop member connecting the wall and the impermeable portion.

According to the above configuration, in an embankment in which a wall is cast on the embankment, an impermeable structure installed in an area including above the wall extends over a predetermined overhang length. During periods of flooding, the point where overflow water falls on the back side of the river is farther away from the wall, and the ground bearing capacity for the wall is maintained even in situations where the foundation ground is scoured. Therefore, according to the above configuration, the strength of the embankment during overflow can be improved.

1 is a schematic cross-sectional view showing the structure of an embankment according to a first embodiment of the present invention. FIG. 2 is a diagram showing the state of the embankment shown in FIG. 1 when water overflows. FIG. 3 is a diagram for explaining a lower limit value of an overhang length. It is a schematic sectional view showing the structure of the embankment concerning the 2nd embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing the structure of an embankment according to a third embodiment of the present invention. It is a schematic perspective view which shows the structure of the embankment based on the 3rd Embodiment of this invention. FIG. 3 is a diagram for explaining an example in which a water stop member is provided in an embodiment of the present invention. FIG. 3 is a diagram for explaining an example in which a water stop member is provided in an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that, in this specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals and redundant explanation will be omitted.

FIG. 1 is a schematic cross-sectional view showing the structure of an embankment according to a first embodiment of the present invention. In this embodiment, the embankment 10 includes a steel sheet pile wall 11, which is a first wall installed on the river front side of the embankment body 1 (river 2 side, which is a water area), and a steel sheet pile wall 11, which is a first wall installed on the river front side of the embankment body 1 (the river side side, which is a water body). It includes a steel sheet pile wall 12 which is a second wall to be cast in a portion (on the opposite side of the river 2), and a tie rod 13 which is a connecting member that connects the heads of each of the steel sheet pile walls 11 and 12. . The embankment body 1 has a slope 1A on the front side of the river, a slope 1B on the back side of the river, and a top surface 1C. In addition, although the tie rod 13 is arrange|positioned as a connection member in this embodiment, the connection member is not specifically limited as long as it is a member which can connect between the steel sheet pile walls 11 and 12 and can transmit tensile force and shear force. For example, the connecting member may be constructed of a wall made of steel installed perpendicularly to each steel sheet pile wall. Alternatively, for example, as in the example described later, when concrete is poured across the heads of the steel sheet pile walls 11 and 12 as a member provided on the top surface, a separate connecting member may not be provided. Good too.

In the embankment 10 as described above, a pavement structure 14 is further installed on the top surface 1C of the embankment body 1. The pavement structure 14 is installed to use the top surface 1C as a road or promenade, and includes, for example, a surface layer and a base layer formed from an asphalt mixture from the surface side, and a roadbed formed from crushed stone or the like. Such a pavement structure 14 is an example of the top structure in this embodiment, and is installed so as to protrude by a length B from the outermost edge of the steel sheet pile wall 12 on the river side. Here, the outermost edge means, for example, when the steel sheet pile wall 12 has a corrugated cross section as a whole, the surface on the river side where the corrugation extends to the river side. If the steel sheet pile wall has a straight cross section, the surface on the river side will simply be the outermost edge. The overhang length B is the distance from the outermost edge of the steel sheet pile wall 12 on the river side to the end of the pavement structure 14 on the river side. For example, when the steel sheet pile wall 12 is composed of a hat-shaped steel sheet pile or a U-shaped steel sheet pile and has a corrugated cross section, the portion of the corrugated cross section that protrudes toward the river side is used as the reference for the overhang distance B. Further, the height of the upper surface of the pavement structure 14 with respect to the foundation ground is defined as the embankment height H.

FIG. 2 is a diagram showing the state of the embankment shown in FIG. 1 when water overflows. In the illustrated state, the water level of the river 2 rises and overflow occurs beyond the height of the upper surface of the embankment 10, that is, the upper surface of the pavement structure 14, and the slope 1B on the river side of the embankment body 1 has already been It has been washed away. In this state, overflow water that has crossed the pavement structure 14 and reached the back side of the river falls from the end of the pavement structure 14 and scours the foundation ground. Let d be the horizontal movement distance from the end of the pavement structure 14 to the overflow point P where the overflow water reaches the foundation ground, and let R be the diameter of the standing vortex generated by the overflow water at the overflow point P. According to Kenji Noguchi et al., “Large-scale model experiment of seawall overtopping and front scouring due to tsunami run-up,” Coastal Engineering Journal, Vol. 44, pp. 296-300, 1997, the width of scouring (on both sides) by water current is fixed. It is proportional to the diameter R of the existing vortex. Therefore, the distance s where the ground remains on the river side of the steel sheet pile wall 12 can be expressed by the following equation (1). However, the coefficient α is unknown.

By securing this distance s, the ground supporting force for the steel sheet pile wall 12 can be maintained even in situations where the foundation ground is scoured on the back side of the river, and deformation and displacement of the steel sheet pile walls 11 and 12 can be prevented. The function of the embankment 10 can be maintained by preventing the embankment body 1 from being washed away in areas other than the back side of the river. Therefore, below, based on equation (1), we will consider how to set the overhang length B of the pavement structure 14 in order to secure the necessary distance s.

First, the horizontal movement distance d of the overflow water is expressed by the following equation (2) using the flow velocity v at the time when the overflow water passes the end of the pavement structure 14. Here, g is gravitational acceleration. Further, the flow velocity v, the overflow water depth h ₀ where the maximum water level of the river 2 near the embankment 10 exceeds the embankment height H, and the critical water depth h _c at the time when the overflow water passes the end of the pavement structure 14. The relationship of equation (3) holds true between them. Equation (3) assumes that the flow velocity in the overflow direction, that is, the direction crossing the embankment 10, is almost 0 in the maximum water level part of the river 2, and the flow velocity v is calculated assuming that the overflow water depth _h0 is equal to the total water head. It is being calculated. Here, according to Mikio Hino, "Clear Hydraulics", Maruzen Co., Ltd., p. 107, 2001, in equation (3), if the critical water depth h _c is set to 2/3 of the overflow water depth h ₀ , and the flow velocity v is calculated, equation (4) is obtained. By substituting this into equation (2), equation (5) is obtained.

On the other hand, the diameter R of the standing vortex is calculated using the following equation (6). Here, q is the flow rate of overflow water, and is the product of the critical water depth _hc and the flow velocity v. Equation (7) is obtained by setting the critical water depth h _c to 2/3 of the overflow water depth h ₀ and substituting q calculated using the flow velocity v calculated by Equation (4).

Furthermore, an experiment was conducted to determine the coefficient α of equation (1). Using a ground material with D ₅₀ = 0.5 mm, where erosion is most likely to occur, and a model of levee 10 with a levee height H of 400 mm, the overflow water depth h ₀ was set to 20 mm, 30 mm, and 40 mm, and overflow was carried out. When the diameter R of the standing vortex calculated from equation (7) using running water was compared with the size of the actually measured scour range, the coefficient α≈7 was found. This result is consistent with the results of previous scour experiments. Furthermore, based on actual experience when rivers overflow, the maximum overflow water depth _h0 is approximately 0.6 m. Therefore, in the above formula (1), d calculated by formula (5), R calculated by formula (7), α = 7, h ₀ = 0.6 (m) and g = 9.8 (m /s ² ), equation (8) is obtained. If the minimum condition that the ground remains on the river side of the steel sheet pile wall 12 is s>0, and the equation (8) is changed to a conditional equation for the overhang length B, the equation (9) is obtained.

On the other hand, in Yuta Mitobe et al., "Numerical experiment on the mitigation effect of tsunami energy attenuation by scouring behind the coastal embankment," Transactions of the Japan Society of Civil Engineers B2 (Coastal Engineering), Vol. 74, No. 2, I_223-I_228, 2018, Equation (10) has been proposed as an empirical formula for calculating the scour width (both sides) L _f from the height H and the overflow water depth h ₀ . In equation (10), αR in equation (1) is replaced with scour width L _f =4.24H ^0.18 , which is calculated as h ₀ =0.6 (m) in the same way as in the above example, and the other terms are Similarly to the above equation (9), if we set h ₀ = 0.6 (m) and g = 9.8 (m/s ² ) and s > 0 as a conditional expression for the overhang length B, equation (11) becomes can get.

As shown in equation (5), when the bank height H is large, the horizontal movement distance d becomes large and always exceeds the scour width, so the values on the right side of equations (9) and (11) above are becomes less than 0. In this case, the lower limit of the overhang length B is set so that at least the surface of the steel sheet pile does not enter the scouring range so that the steel sheet pile wall is not damaged by muddy currents containing earth and sand. According to the findings of the present inventors, the lower limit of such an overhang length B is 300 mm. As shown in Figure 3, in a river embankment with a typical height H of 2 m to 6 m, if we target the overflow water depth h ₀ of 0.2 m or more where scouring occurs due to overflow, especially In areas where the overflow water depth _h0 is large, where the scouring depth becomes deep and affects the stability of the sheet pile, an overhang length of 300 mm or more is required to prevent the scouring influence area A from reaching the steel sheet pile wall. . Such an overhang length B exceeds the overhang length of cap concrete that is generally cast to protect the head of a steel sheet pile wall. An example of the overhang length of general cap concrete is described in the Steel Pipe Pile Association's "Steel Sheet Pile - From Design to Construction", pp. 353-354, 1998, and is about 175 mm at maximum.

In addition, when setting the overhang length B as described above, the top structure such as the pavement structure 14 is an impermeable member that does not allow overflow water to pass from the upper surface side to the lower surface side when water overflows. . For example, if a crown structure has an impermeable part such as a pavement structure or concrete and a permeable part such as a protective net, only the impermeable part is treated as the crown structure. Set the overhang length B. However, since it is sufficient that the overflow water that has permeated does not wash away the embankment body 1 on the underside of the crown structure, complete watertightness is not necessarily required even in the impermeable parts of the crown structure. , as long as it is substantially water-impermeable.

In the above equations (9) and (11), the minimum condition for the remaining ground on the river side of the steel sheet pile wall 12 is set to s>0, but when considering the safer side, the following example You may set the lower limit value L of the distance s where the ground remains on the river side of the steel sheet pile wall 12 as shown in FIG. In this case, the conditions of the following equation (12) are set, with the right sides of equations (9) and (11) being a function f(H) of the embankment height H.

As a first example, consider the range in which passive resistance is exerted in the ground at the embedded part of the steel sheet pile wall 12. According to the Steel Pipe Pile Association's "Steel Sheet Pile - From Design to Construction", 1998, from the theory of beams on elastic floors, the depth of the first fixed point of the pile embedded in the ground is calculated under the condition that the pile head does not rotate. When the above lower limit L is calculated as the distance from the pile to the point where a line obtained by extending the passive collapse angle φ from that depth intersects with the substrate surface, the following equation (13) is obtained. Here, β is a coefficient calculated as β=(E _s /4EI) ^1/4 , E _s is a deformation coefficient, and E and I are Young's modulus and moment of inertia of the steel sheet pile.

As a second example, according to the Architectural Institute of Japan "Architectural Foundation Structure Design Guidelines" p277, 2019, regarding the horizontal resistance of piles near sloped ground, if the distance to the slope is greater than 2.5/β, the slope It is said that the design can be done while ignoring the influence of surfaces. If this slope is replaced with a portion where the foundation ground has disappeared due to scouring by overflow water, the above lower limit value L is calculated as shown in the following equation (14). Note that β is a coefficient calculated as β=( _kh D/4EI) ^1/4 as in the first example.

FIG. 4 is a schematic cross-sectional view showing the structure of an embankment according to a second embodiment of the present invention. In the embankment 20 according to this embodiment, a concrete top slab 24 is installed as a top structure. The heads of the steel sheet pile walls 11 and 12 are embedded in the top slab concrete 24. As already mentioned, in this case, there is no need to provide a separate connecting member between the steel sheet pile walls 11 and 12. The rest of the configuration is the same as that of the first embodiment, so redundant detailed explanation will be omitted. In this embodiment as well, the overhang length B, which is the distance from the outermost edge of the steel sheet pile wall 12 on the river side to the end of the top slab concrete 24 on the river side, is calculated according to the embankment height H using the formula (9) or the formula By setting according to equation (11) or equation (12), the ground supporting force for the steel sheet pile wall 12 can be maintained even in a situation where the foundation ground is scoured on the back side of the river.

5 and 6 are a schematic cross-sectional view and a perspective view showing the structure of an embankment according to a third embodiment of the present invention. Note that the perspective view in FIG. 6 shows the embankment body 1 seen through. In the embankment 30 according to the present embodiment, instead of installing an impermeable crown structure, an impermeable structure is installed from the cap concrete 34 cast at the head of the steel sheet pile wall 12 to the back side of the river along the slope. A water-permeable overhang member 35 is installed. The overhanging member 35 is formed of, for example, a steel plate, a concrete plate, or a resin plate. As in this embodiment, even when the impermeable structure installed in the area including above the steel sheet pile wall 12 of the embankment body 1 is not a crown structure, the overhang length of the overhang member 35 in the horizontal direction If B is set to satisfy Equation (9), Equation (11), Equation (12), or Equation (13) in relation to levee height H, scouring of the foundation ground will occur on the back side of the river. The ground supporting force for the steel sheet pile wall 12 can be maintained even under such conditions.

FIGS. 7 and 8 are diagrams for explaining an example in which a water stop member is provided in the embodiment of the present invention. FIG. 7 shows an example of an embankment 40 in which steel sheet pile walls 11 and 12 are placed on the embankment body 1 and a pavement structure 14 is installed as the crown structure, similar to the first embodiment described above. ing. In the embankment 40, the head of the steel sheet pile wall 11 on the river front side and the pavement structure 14 are connected by a water stop member 46.

As described above, the pavement structure 14 is a water-impermeable structure in that overflow water does not permeate from the upper surface side to the lower surface side when water overflows. However, the pavement structure 14 includes, for example, a surface layer and a base layer formed of an asphalt mixture from the surface layer side, and a roadbed formed of crushed stone, etc., and the roadbed portion is not necessarily impermeable to water. In other words, overflow water does not permeate from the upper side to the lower side of the pavement structure 14, but passes through the connecting part between the pavement structure 14 and the steel sheet pile, or the underside of the roadbed part of the pavement structure 14, and then flows from the river surface side. There is a possibility that overflow water will penetrate to the other side of the river. When the overflow water passes through and flows between the pavement structure 14 and the steel sheet pile walls 11 and 12 in this way, the pavement structure 14 eventually rises from the steel sheet pile walls 11 and 12 and the dam body 1 The top surface 1C will collapse. In this case, as described above, the effect of leaving the ground on the river side of the steel sheet pile wall 12 by moving the pavement structure 14 away from the falling point P of the overflow water cannot be obtained.

Therefore, in the example shown in FIG. 7, the head of the steel sheet pile wall 11 and the impermeable part of the pavement structure 14 are connected with a water stop member 46 such as swollen rubber, so that overflow water can flow between the pavement structure 14 and the steel sheet pile. This prevents the liquid from flowing between the walls 11 and 12. As a result, even when the crown structure includes a partially water-impermeable layer like the pavement structure 14, the function of the portion of the crown structure overhanging to the river side can be maintained. In addition, the water stop member may connect between the head of the steel sheet pile wall 12 and the water-impermeable part of the pavement structure 14.

In the example of FIG. 8, in the embankment 50 where only the steel sheet pile wall 11 on the river front side is poured, the steel sheet pile wall 11 and the impermeable portion of the pavement structure 14 are connected by a water stop member 46. As a result, the portion of the pavement structure 14 that extends from the outermost edge of the river side of the steel sheet pile wall 11 to the river side by a length B moves the steel sheet pile wall 11 away from the falling point P (see FIG. 2) of overflow water. The ground on the back side of the river can be left and the reinforcing effect of the steel sheet pile wall 11 on the embankment body 1 can be maintained. Note that the overhang length B in this case is also calculated in the same manner as in the example described in the first embodiment.

Note that, for example, as described in the second and third embodiments above, the impermeable structure installed in the area including above the steel sheet pile wall includes top plate concrete, cap concrete, etc. When the head of the wall is embedded in these structures, overflow water will not flow between the steel sheet pile wall and the structure, so a water stop member as described above is not necessary.

According to the embodiment of the present invention as described above, in the embankment in which the walls (steel sheet pile walls 11 and 12) are placed on the embankment body 1, an impermeable structure is provided in the area including the upper part of the wall. (paving structure 14 or top slab concrete 24, or overhanging member 35) is installed so that this structure overhangs the river side of the wall by a predetermined overhang length B. In this way, the point P of the overflow water on the back side of the river is moved away from the wall at the time of overflow, and the ground supporting force for the wall can be maintained even in a situation where the foundation ground is scoured.

Although preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that those skilled in the art to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims, and these also include: It is understood that it naturally falls within the technical scope of the present invention.

10, 20, 30, 40, 50... Embankment, 1... Embankment body, 1A... Slope, 1B... Slope, 1C... Top surface, 2... River, 11, 12... Steel sheet pile wall, 13... Tie rod, 14... Paving structure, 24...Top slab concrete, 34...Cap concrete, 35...Overhanging member, 46...Water stop member.

Claims (13)

a first wall that is cast on a water area side portion of the embankment;
a second wall installed in a portion of the embankment opposite to the water area;
An impervious wall installed in an area including at least above the second wall, and extending horizontally from the outermost edge of the second wall to the side opposite to the water area with an overhang length B of 300 mm or more. Embankment with structures and. The levee according to claim 1, wherein the overhang length B satisfies equations (i) and (ii) including a function f(H) of levee height H.

The levee according to claim 1, wherein the overhang length B satisfies equations (i) and (iii) including a function f(H) of levee height H.

The overhang length B further satisfies formula (iv), which further includes a ground remaining length L, which is the distance from the position closest to the second wall in the scoured area to the second wall. , the embankment according to claim 2 or claim 3.

The embankment according to claim 4, wherein the ground remaining length L is defined by equation (v) using a coefficient β and a passive collapse angle φ.

The embankment according to claim 4, wherein the ground remaining length L is defined by equation (vi) using a coefficient β.

The embankment according to any one of claims 1 to 6, wherein the impermeable structure is a crown structure installed on the crown face of the embankment body. The embankment according to claim 7, wherein the crown structure is a pavement structure. The embankment according to claim 8, wherein at least one of the first and second walls and an impermeable portion of the pavement structure are connected by a water stop member. The embankment according to claim 7, wherein the crown structure is made of concrete. The embankment according to any one of claims 1 to 6, wherein the impermeable structure is an overhang member that extends from the second wall to a side opposite to the water body. The embankment according to any one of claims 1 to 11, wherein at least one of the first and second walls is a steel sheet pile wall. A wall to be installed on the embankment body,
It is installed in an area that includes at least the upper part of the wall, extends horizontally from the wall to the side opposite to the water area with an overhang length B larger than 300 mm, includes an impermeable part on the upper surface side, and has an impermeable part on the lower surface side. A structure including a water-permeable part;
An embankment comprising: a water stop member connecting the wall and the impermeable part.

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