JP7172446B2 - embankment structure - Google Patents

Description

The present invention relates to embankment structures such as embankments.

In recent years, levee breaches due to earthquakes have occurred frequently, and several large-scale earthquakes are expected to occur in the near future.

On the other hand, in the past, techniques for reinforcing embankments or embankments using steel sheet piles have been proposed (see Patent Documents 1 and 2, for example).
In the embankment reinforcement structure described in Patent Document 1, at least one row of sheet pile walls having a depth that penetrates the embankment and is embedded in the supporting ground is continuous in the longitudinal direction of the embankment except for the toe of the embankment. A structural frame is formed by a sheet pile wall in the ground that constitutes the embankment and the ground closed off by the sheet pile wall.
In such an embankment reinforcement structure, at least one row of sheet pile walls penetrates the embankment at a position other than the toe of the slope and is embedded in the supporting ground, so that the interior of the embankment has a structural framework of two or more compartments in the width direction. Since it is divided into sections, groundwater and seepage water are prevented from penetrating the entire width of the embankment, and even if the foundation ground becomes unstable due to external forces during floods or earthquakes, the structural frame itself remains stable. is ensured.

In addition, in the embankment reinforcement structure described in Patent Document 2, one or more rows of steel sheet pile walls are provided along the continuous direction of the embankment within the range of the approximate top end of the continuous embankment, and the steel sheet pile wall is In an embankment reinforcement structure embedded to a depth shallower than a support layer, steel support members embedded to the support layer are discretely arranged at predetermined intervals in the continuous direction of the embankment at the toe of the embankment, The steel sheet pile wall and each of the steel supporting members are connected by first connecting members, respectively, so that the steel sheet pile wall is supported by the steel supporting members via the first connecting members.
In such an embankment reinforcement structure, the steel sheet pile wall and each steel supporting member are connected by the first connecting member, respectively, so that the steel sheet pile wall is supported by the steel supporting member via the first connecting member. Therefore, it is possible to suppress the settlement of the steel sheet pile wall inside the embankment during an earthquake, which has the effect of suppressing the settlement of the embankment during an earthquake and preventing the breakage of the embankment when water overflows.

JP-A-2003-13451 JP 2015-168952 A

However, in the above-described conventional embankment reinforcement structure, although the effect of suppressing the deformation of the core portion of the embankment or the foundation ground is exhibited, the deformation and collapse of the slope are allowed. Therefore, if there are important infrastructure facilities, houses, emergency evacuation routes, etc. on the downstream side of embankments such as embankments, it may lead to serious damage.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an embankment structure that can dam the earth and sand due to the slope collapse even if the embankment such as an embankment collapses. .

In order to achieve the above object, the embankment structure of the present invention is characterized in that, of two slopes on one side and the other across the top of a continuous embankment, at least the one side slope and the most A first steel sheet pile wall is provided along the continuous direction of the embankment on the one side of the slope shoulder of the slope near the top, and the head of the first steel sheet pile wall is located on the one side of the embankment. Protruding above the ground surface or the one side slope or bench of the embankment,
It is characterized in that the head of the first steel sheet pile wall dams up earth and sand caused by a slope failure on the one side of the embankment.

In the present invention, since the head of the first steel sheet pile wall is projected upward from the ground surface on one side of the embankment, the slope on one side of the embankment, or the bench, the head of the first steel sheet pile wall can be used for embankment It is possible to dam the sediment caused by slope failure on one side of the slope.
Therefore, even if the slope collapses due to an earthquake or the like, it is possible to prevent the earth and sand from moving over the first steel sheet pile wall and causing damage.

In addition, the structure of the embankment of the present invention is such that water exists on the other side, and when the other side is the upstream side and the one side is the downstream side, the downstream side slope shoulder located on the most upstream side of the embankment On the downstream side, the first steel sheet pile wall projects the head of the first steel sheet pile wall above the ground surface on the downstream side of the embankment, or the slope or bench on the downstream side of the embankment. It is characterized in that it is arranged in a state in which it is folded.

According to such a structure, even when the embankment is used as an embankment, the head of the first steel sheet pile wall can dam the earth and sand caused by the slope collapse on the downstream side of the embankment.
Therefore, even if the slope collapses due to an earthquake or the like, it is possible to prevent the earth and sand from moving over the first steel sheet pile wall and causing damage to the downstream side.

Moreover, the said structure of this invention WHEREIN: The 2nd steel sheet pile wall may be provided in the top end of the said embankment along the continuous direction of the said embankment.

According to such a configuration, the second steel sheet pile wall can reduce the infiltration line in the embankment and maintain the strength of the embankment, and by maintaining the height of the embankment, it suppresses damage due to collapse of the embankment and overflow of water. can. In particular, when embankments are used as embankments, the second steel sheet pile wall maintains the height of the embankment (embankment), thereby suppressing damage caused by collapse of the embankment (embankment) and overflow of water. ) can reduce the infiltration line inside and maintain the strength of the embankment.

Further, in the above configuration of the present invention, the first steel sheet pile wall is provided on the downstream side slope toe of the embankment, and the second steel sheet pile wall is provided on the upstream side slope shoulder of the crest of the embankment,
The projection length of the head of the first steel sheet pile wall is h (m), the width of the top end is B (m), the height of the embankment is H (m), and the slope angle on the downstream side of the embankment is θ Then, the following formula (1) may be satisfied.

According to such a configuration, by setting the projection length h of the head of the first steel sheet pile wall provided at the downstream side slope toe of the embankment so as to satisfy the expression (1), slope collapse sediment can be prevented. The first steel sheet pile wall provided at the bottom of the slope on the downstream side receives all of it, and damage on the downstream side due to slope collapse earth and sand can be reliably prevented.

Further, in the above configuration of the present invention, the first steel sheet pile wall is provided on the ground surface on the downstream side of the embankment, and the second steel sheet pile wall is provided on the upstream shoulder of the crest of the embankment,
The projection length of the head of the first steel sheet pile wall is h, the width of the top end is B, the height of the embankment is H, the slope angle on the downstream side of the embankment is θ, the first steel sheet pile wall and the above Assuming that the horizontal distance between the embankment and the bottom of the slope on the downstream side is b, the following formula (2) may be satisfied.

According to such a configuration, by setting the projection length h (m) of the head of the first steel sheet pile wall provided on the ground surface on the downstream side of the embankment so as to satisfy the equation (2), the law The first steel sheet pile wall provided on the ground surface on the downstream side receives all of the surface collapsed earth and sand, and the damage on the downstream side due to the collapsed earth and sand can be reliably prevented.

Further, in the above configuration of the present invention, the first steel sheet pile wall is provided on the slope on the downstream side of the embankment, and the second steel sheet pile wall is provided on the upstream shoulder of the crest of the embankment,
The projection length of the head of the first steel sheet pile wall is h (m), the width of the top end is B (m), the height of the embankment is H (m), and the slope angle on the downstream side of the embankment is θ Assuming that the horizontal distance between the first steel sheet pile wall and the bottom of the slope on the downstream side of the embankment is b (m), the following equation (3) may be satisfied.

According to such a configuration, by setting the projection length h (m) of the head of the first steel sheet pile wall provided on the slope on the downstream side of the embankment so as to satisfy the equation (3), the The first steel sheet pile wall provided on the downstream side of the slope receives all the slope collapse sediment upstream of the first steel sheet pile wall, and the downstream damage due to the slope collapse sediment can be reliably prevented.

In the configuration of the present invention, when the second steel sheet pile wall is provided, at least one of the first steel sheet pile wall and the second steel sheet pile wall is provided with a water-permeable steel sheet pile. may be

According to such a configuration, since at least one of the first steel sheet pile wall and the second steel sheet pile wall is provided with a permeable steel sheet pile, water in the embankment is directed to one side (downstream side ) can be drained smoothly. Therefore, it is possible to prevent the water level in the embankment from becoming excessively high, so that the embankment destruction suppression effect of the embankment can be achieved.

ADVANTAGE OF THE INVENTION According to this invention, even if slope collapse occurs in embankments, such as an embankment, the earth and sand by the said slope collapse can be dammed up by the 1st steel sheet pile wall.

BRIEF DESCRIPTION OF THE DRAWINGS The structure of the embankment as embankment which concerns on the 1st Embodiment of this invention is shown, (a) is a cross-sectional view of an embankment, (b) is a top view of an embankment. 1 is a cross-sectional view of an embankment having a plurality of slopes on each of the upstream side and the downstream side, showing the structure of the embankment as an embankment according to the first embodiment of the present invention; FIG. It is a cross-sectional view which shows the state which dams the earth and sand by slope collapse by the 1st steel sheet pile wall equally. It is a cross-sectional view of an embankment for demonstrating the protrusion length of the head of a 1st steel sheet pile wall equally. FIG. 10 is a cross-sectional view of the embankment for explaining the projection length of the head portion of the first steel sheet pile wall, showing the structure of the embankment as the embankment according to the second embodiment of the present invention. Fig. 10 is a cross-sectional view of the embankment for explaining the projection length of the head portion of the first steel sheet pile wall, showing the structure of the embankment as the embankment according to the third embodiment of the present invention. 1 is a cross-sectional view showing an embankment (embankment) to be studied in an embodiment of the present invention; FIG. It is for explaining the embodiment of the present invention, (a) is a cross-sectional view of the embankment (bank) corresponding to the first embodiment, (b) is the embankment corresponding to the second embodiment ( (c) is a cross-sectional view of an embankment (bank) corresponding to the third embodiment.

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 structure of the embankment (levee) according to the first embodiment, (a) is a cross-sectional view, and (b) is a plan view.
This embodiment shows a case where the embankment is used as a bank, and in FIG. The embankment 10 is constructed by this embankment. Water W exists. Therefore, the embankment 10 constitutes a reservoir embankment, a river embankment, a coastal embankment, or the like.
In the following description, one side (the right side in FIGS. 1A and 1B) will be described as the downstream side, and the other side (the left side in FIGS. 1A and 1B) will be described as the upstream side.

The embankment 10 has a slope 12 on the upstream side and a slope 13 on the downstream side across a crest 11. - 特許庁The slopes 12 and 13 have the same inclination angle θ with respect to the ground surface GS, but the slopes 12 and 13 may have different inclination angles θ.
In addition, on the downstream side of the downstream slope shoulder 13a located on the most upstream side of the embankment 10, the first steel sheet pile wall 20 extends in the continuous direction of the embankment 10 (the direction orthogonal to the paper surface in FIG. 1(a), (b) in the vertical direction).
For example, in the present embodiment, the first steel sheet pile wall 20 is provided along the continuous direction of the embankment 10 at the toe 13e downstream of the downstream shoulder 13a positioned most upstream.
The first steel sheet pile wall 20 is formed by connecting a plurality of steel sheet piles 20a in the continuous direction of the embankment 10, and the steel sheet piles 20a are driven into the ground G substantially vertically from the toe 13e of the slope. It is formed by connecting to the steel sheet pile 20a that has been placed by pressing.
If the length of one steel sheet pile 20a is insufficient, a plurality of steel sheet piles 20a are vertically spliced and driven into the ground G from the toe 13e.

Here, the embankment 10 may have a plurality of slopes on the upstream side and/or the downstream side. For example, embankment 10 shown in FIG. 1A has two slopes 12b and 12c on the upstream side and three slopes 13b, 13c and 13d on the downstream side. A small step 15 is provided between the slope 12b and the slope 12c on the upstream side, and a small step 16 is provided between the slope 13b and the slope 13c on the downstream side. A horizontal portion provided between 13c and slope 13d is small step 17 .

Therefore, in the embankment 10 shown in FIG. 1A, the most upstream downstream slope shoulder is the slope shoulder 13a of the slope 13b. Therefore, the first steel sheet pile wall 20 is provided on the downstream side (right side in FIG. 1A) of the downstream slope shoulder 13a. For example, the first steel sheet pile wall 20 includes the downstream side slopes 13b and 13c, the small steps 16 and 17, the most downstream side slope 13e, and the ground surface GS downstream of the slope 13e by a predetermined distance. provided in Note that FIG. 1A illustrates an example in which the first steel sheet pile wall 20 is provided on the small step 17 or the downstream side slope 13e, but the first steel sheet pile wall 20 is positioned on the most upstream side described above and located on the downstream side. It may be provided on the downstream side of the shoulder 13a.

In the embankment 10 shown in FIGS. 1(a) and 1(b), the first steel sheet pile wall 20 has its head portion 20b projecting upward from the ground surface GS and from the downstream side slope 13e. Since the downstream side slope 13e is positioned on the ground surface GS, the head 20b protrudes upward from the ground surface GS by protruding upward from the slope 13e. Then, as shown in FIG. 2, the head 20b of the first steel sheet pile wall 20 dams up the earth and sand S caused by the slope collapse on the downstream side of the second steel sheet pile wall 25 of the embankment 10. As shown in FIG. The second steel sheet pile wall 25 will be described later.
In addition, in the embankment 10 shown in FIG. 1A, the head 20b of the first steel sheet pile wall 20 projects upward from the ground surface GS on the downstream side of the embankment 10, the slopes 13b and 13c on the downstream side, or the small steps 16 and 17. Let it be. The head portion 20b of the first steel sheet pile wall 20 dams up the earth and sand caused by the slope collapse on the downstream side of the embankment 10. As shown in FIG. It is the earth and sand caused by the slope collapse on the upstream side of the first steel sheet pile wall 20 that can dam up the earth and sand caused by the slope collapse.

Further, as shown in FIGS. 1(a) and 1(b), a second steel sheet pile wall 25 is provided at the crest 11 of the embankment 10 along the direction in which the embankment 10 continues. Specifically, the second steel sheet pile wall 25 is provided on the upstream slope shoulder 12a or on the crown 11 slightly downstream of the upstream slope shoulder 12a.
The second steel sheet pile wall 25 is formed by connecting a plurality of steel sheet piles 25a in the continuous direction of the embankment 10, and the steel sheet piles 25a penetrate the embankment 10 substantially vertically from the upstream shoulder 12a. It is formed by driving into the ground G and connecting to the previously driven steel sheet pile 25a. Moreover, the upper end of such a second steel sheet pile wall 25 is substantially flush with the top end 11 . In addition, although the driving depth of the second steel sheet pile wall 25 from the ground surface GS is equal to that of the first steel sheet pile wall 20, it may be different. The lower end of the second steel sheet pile wall 25 preferably reaches below the ground surface GS. may
If the length of one steel sheet pile 25a is insufficient, a plurality of steel sheet piles 25a are vertically spliced and driven into the embankment 10 from the upstream slope shoulder 12a.
By providing the second steel sheet pile wall 25 in the embankment 10 in this way, the seepage line WL in the embankment 10 can be lowered.

Moreover, at least one of the first steel sheet pile wall 20 and the second steel sheet pile wall 25 may be provided with a water permeable steel sheet pile. In this case, the plurality of steel sheet piles 20a forming the first steel sheet pile wall 20 and the plurality of steel sheet piles 25a forming the second steel sheet pile wall 25 may all be made of water-permeable steel sheet piles. The steel sheet piles 20a and 25a may be made of water-permeable steel sheet piles. As the water-permeable steel sheet pile, for example, a steel sheet pile in which a plurality of water-permeable holes are formed vertically and horizontally at predetermined intervals is used. In addition, a plurality of permeable holes may be formed at predetermined intervals over the entire top and bottom of the steel sheet pile, or may be formed at predetermined intervals vertically only in the portion of the steel sheet pile that protrudes upward from the ground surface GS.

At least part of the first steel sheet pile wall 20 is composed of water permeable steel sheet piles, that is, only the first steel sheet pile wall 20 has water permeability, and the second steel sheet pile wall 25 does not have water permeability. In this case, since the water W on the upstream side that permeates from the slope 12 of the embankment 10 does not enter the embankment 10 on the downstream side of the second steel sheet pile wall 25, it is possible to suppress the strength reduction of the embankment 10, and the ceiling of the embankment 10 Since part of the water remaining in the ground G below the edge 11 can be discharged to the outside through the first steel sheet pile wall 20, liquefaction caused by an earthquake or the like can be suppressed.
In addition, at least part of the second steel sheet pile wall 25 is composed of water-permeable steel sheet piles, that is, only the second steel sheet pile wall 25 has water permeability, and the first steel sheet pile wall 20 has water permeability. If not, water inside the embankment 10 and water in the ground G below the embankment 10 can be prevented from reaching the ground G downstream of the first steel sheet pile wall 20 . Therefore, liquefaction caused by an earthquake or the like in the ground G immediately below the building constructed on the ground surface GS on the downstream side of the first steel sheet pile wall 20 can be suppressed.
In addition, when both the first steel sheet pile wall 20 and the second steel sheet pile wall 25 have water permeability, it is possible to suppress the retention of water inside the embankment 10, suppress the strength reduction of the embankment 10, and By suppressing retention of water in the ground G below 10, liquefaction of the ground G caused by an earthquake or the like can be suppressed.

Moreover, in the present embodiment, as shown in FIG. Based on the geometrical relationship in the cross section, the minimum protrusion length that can dam all the earth and sand even if the range from the crown 11 to the downstream slope 13 completely collapses is defined.

That is, as shown in FIG. 3, above the line segment L reaching the second steel sheet pile wall 25 horizontally toward the second steel sheet pile wall 25 through the top of the head 20b of the first steel sheet pile wall 20 The cross-sectional area of the embankment 10 (indicated by hatching) is S1, the cross-sectional area of the portion surrounded by the line segment L, the head 20b of the first steel sheet pile wall 20, and the slope 13 below the line segment L (hatched ) is S2, S1≦S2 is sufficient to dam all the earth and sand even if the range from the top 11 to the downstream side slope 13 collapses completely.

Therefore, the projection length of the head 20b of the first steel sheet pile wall 20 is h (m), the width of the crest 11 is B (m), the height of the embankment 10 is H (m), and the downstream slope of the embankment 10 is If the angle is θ, the minimum protrusion of the head 20b that can dam all the earth and sand even if the range from the crown 11 to the downstream side slope 13 completely collapses by satisfying the following formula (1) length can be specified.

As described above, according to the present embodiment, the head portion 20b of the first steel sheet pile wall 20 is projected upward from the downstream slope 13e of the slope 13 on the downstream side of the embankment 10. The head 20b of the sheet pile wall 20 can dam the earth and sand caused by the slope failure of the slope 13 on the downstream side of the embankment 10. - 特許庁
Therefore, even if the slope collapses due to an earthquake or the like, the soil is prevented from moving beyond the first steel sheet pile wall 20 and causing damage to important infrastructure facilities, houses, emergency evacuation routes, etc. existing downstream. be able to.

In addition, since the second steel sheet pile wall 25 is provided along the continuous direction of the embankment 10 on the upstream slope 12a of the crest 11 of the embankment 10, the second steel sheet pile wall 25 maintains the embankment height. As a result, it is possible to suppress the damage caused by the breakage of the embankment 10 and the overflow of water, and to reduce the seepage line WL in the embankment 10 to maintain the strength of the embankment 10 .
Furthermore, by setting the projection length h of the head 20b of the first steel sheet pile wall 20 provided at the downstream side slope 13e of the embankment 10 so as to satisfy the equation (1), the slope collapse sediment is completely removed downstream The first steel sheet pile wall 20 provided at the side slope bottom 13e receives the load, and can reliably prevent damage on the downstream side due to slope collapse sediment.

(Second embodiment)
FIG. 4 is a cross-sectional view showing the structure of the embankment according to the second embodiment.
As in the first embodiment, the embankment of the present invention is also used as a bank in the second embodiment. This second embodiment differs from the first embodiment in that the first steel sheet pile wall 20 is provided on the ground surface GS downstream of the downstream slope 13e of the embankment 10 by a predetermined distance. Therefore, this point will be described below, and the same reference numerals will be given to the same configurations as in the first embodiment, and the description thereof will be omitted.

In the second embodiment, the first steel sheet pile wall 20 is provided on the ground surface GS downstream by a predetermined distance from the downstream side slope 13e of the embankment 10, and the head 20b of the first steel sheet pile wall 20 projects upward from the ground surface GS.
Also in this embodiment, as in the first embodiment, the head of the first steel sheet pile wall 20 provided on the ground surface GS downstream by a predetermined distance from the downstream side slope 13e of the embankment 10 Regarding the projecting length of the portion 20b, based on the geometrical relationship in a cross section in the continuous direction of the embankment 10, even if the range from the crest 11 to the downstream side slope 13 completely collapses, all earth and sand can be dammed. defines the minimum possible overhang length.

That is, the cross-sectional area ( hatched) is S1, the line segment L, the head 20b of the first steel sheet pile wall 20, the slope 13 below the line segment L, and the ground surface between the toe 13e and the first steel sheet pile wall 20 Assuming that the cross-sectional area (shown by hatching) of the portion surrounded by GS is S2, even if the range from the crest 11 to the downstream side slope 13 completely collapses, in order to dam all the earth and sand, S1 ≤ S2 If it is

Therefore, the projection length of the head 20b of the first steel sheet pile wall 20 is h (m), the width of the crown 11 is B (m), the height of the embankment 10 is H (m), and the first steel sheet pile wall 20 is Assuming that the horizontal distance to the downstream side slope 13e is b (m) and the downstream side slope angle of the embankment 10 is θ, the following equation (2) is satisfied. It is possible to define the minimum protrusion length of the head 20b that can dam all the earth and sand even if such a range collapses completely.

According to this embodiment, in addition to obtaining the same effect as the first embodiment, the first steel sheet pile wall 20 provided on the ground surface GS downstream of the downstream side slope 13e of the embankment 10 By setting the protrusion length h of the head 20b to satisfy the equation (2), the first steel sheet pile wall 20 provided on the ground surface GS receives all the slope collapse sediment, and the slope collapse sediment downstream side damage can be reliably prevented.
Further, since the first steel sheet pile wall 20 is provided on the ground surface GS on the downstream side of the downstream side slope toe 13e, the slope on the ground surface GS between the downstream side slope toe 13e and the steel sheet pile wall 20 Part of the collapsed sediment can be accumulated. Therefore, the steel sheet pile wall 20 can be shortened as compared with the first embodiment.

(Third Embodiment)
FIG. 5 is a cross-sectional view showing the structure of the embankment according to the third embodiment.
As in the first and second embodiments, the embankment of the present invention is also used as a bank in the third embodiment. This third embodiment differs from the first and second embodiments in that the first steel sheet pile wall 20 is provided on the slope 13 on the downstream side of the embankment 10, so this point will be described below. will be described, and the same reference numerals will be given to the same configurations as those in the first and second embodiments, and the description thereof will be omitted.

In the third embodiment, the first steel sheet pile wall 20 is provided on the downstream slope 13 of the embankment 10, and the head 20b of the first steel sheet pile wall 20 protrudes upward from the downstream slope 13. there is
Also in this embodiment, as in the first and second embodiments, the projection length of the head portion 20b of the first steel sheet pile wall 20 provided on the downstream slope 13 of the embankment 10 is Based on the geometric relationship in the cross section with 10 continuous directions, even if the range from the crown 11 to the downstream side slope 13 on the upstream side of the first steel sheet pile wall 20 completely collapses, all the earth and sand will be dammed. It defines the minimum protruding length that is possible.

That is, the cross-sectional area ( indicated by hatching) is S1, the line segment L, the head 20b of the first steel sheet pile wall 20, and the downstream side below the line segment L and above the portion where the first steel sheet pile wall 20 and the slope 13 intersect Suppose that the cross-sectional area (shown by hatching) of the portion surrounded by the slope 13 is S2, and the range from the crown 11 to the downstream slope 13 on the upstream side of the first steel sheet pile wall 20 has completely collapsed. In order to dam up all earth and sand, S1 ≤ S2 is sufficient.

Therefore, the projection length of the head 20b of the first steel sheet pile wall 20 is h (m), the width of the crown 11 is B (m), the height of the embankment 10 is H (m), the bottom of the slope 13e and the first steel If the horizontal distance between the sheet pile wall 20 is b (m), the downstream slope angle of the embankment 10 is θ, and the horizontal distance between the first steel sheet pile wall 20 and the downstream slope 13e is b (m), By satisfying the following formula (3), even if the range from the crown 11 to the downstream slope 13 on the upstream side of the first steel sheet pile wall 20 completely collapses, all the earth and sand can be dammed. A minimum protrusion length of 20b can be defined.

According to this embodiment, in addition to obtaining the same effect as the first and second embodiments, the head 20b of the first steel sheet pile wall 20 provided on the downstream side slope 13 of the embankment 10 protrudes. By setting the length h to satisfy the expression (3), the first steel sheet pile wall 20 provided on the downstream side slope 13 with all the slope collapse sediment on the upstream side of the first steel sheet pile wall 20 is It is possible to reliably prevent damage on the downstream side due to slope collapse sediment.
Further, in the present embodiment, since the first steel sheet pile wall 20 is provided on the downstream side slope 13 of the embankment 10, a place for providing the first steel sheet pile wall 20 on the downstream side of the downstream side slope 13e cannot be secured. valid in case.

(Example)
As an embodiment of the present invention, when embankment 10 is embankment 10 having a cross section as shown in FIG. (2) and (3) were obtained using the formulas.
In FIG. 6, the width B (m) of the crest 11 is 4 m, the height H (m) of the embankment 10 is 10 m, and the downstream slope angle θ of the embankment 10 is 30°.
The results are shown in FIG. FIG. 7(a) corresponds to the first embodiment, and when the first steel sheet pile wall 20 is projected upward from the downstream side slope 13e of the embankment 10, FIG. Corresponding to the embodiment, when the first steel sheet pile wall 20 is projected upward from the ground surface GS on the downstream side by a predetermined distance bm from the downstream side slope 13e, FIG. Corresponding to the embodiment, the case where the first steel sheet pile wall 20 is projected from the downstream side slope 13 upstream of the downstream side slope 13e by a predetermined distance bm is shown.

In FIG. 7, h (m) is the protruding length of the head 20b of the first steel sheet pile wall 20, B (m) is the width of the crest 11 = 4 m, H (m) = 10 m is the height of the embankment 10, and 10 was set to θ=30°, and the horizontal distance between the first steel sheet pile wall 20 and the downstream slope bottom 13e was set to b(m)=5.0 m.
Substituting these into the equations (1), (2) and (3) respectively, h≤5.9m for the embankment 10 shown in FIG. 7(a), and for the embankment 10 shown in FIG. , h≦4.8m, and in the case of the embankment shown in FIG. 7(c), h≦8.4m.
That is, in the case of the embankment 10 shown in FIG. 7A, the minimum projection length of the first steel sheet pile wall 20 is 5.9 m, and in the case of the embankment 10 shown in FIG. 7B, the minimum projection length of the first steel sheet pile wall 20 is The length was 4.8 m, and in the case of the embankment shown in FIG. 7(c), the minimum protruding length of the first steel sheet pile wall 20 was 8.4 m.

In this way, if there is room to install the first steel sheet pile wall 20 on the downstream side of the downstream side slope 13e of the embankment 10, the first steel sheet pile is installed on the ground surface further downstream than the downstream side slope 13e. By providing the wall 20 (see FIG. 7(b)), the projection height of the first steel sheet pile wall 20 can be set lower than the first steel sheet pile wall 20 in FIGS. 7(a) and 7(c). Therefore, if the driving depth of the first steel sheet pile wall 20 from the ground surface is constant, the height dimension of the first steel sheet pile wall 20 in FIG. 7(b) can be minimized.

In the above-described first to third embodiments, when the embankment is used as a bank, that is, between one side and the other side of the crown 11 of the bank 10, the water W is present on the other side. For example, the embankment 10 constitutes a reservoir embankment, a river embankment, or a coastal embankment, but the present invention is not limited to embankments and can be applied to embankments other than embankments.

In this case, although illustration is omitted, it is the slope on one side of the two slopes on one side and the other side across the top of the embankment, and the slope on the slope closest to the top of the embankment. A first steel sheet pile wall is provided on the one side along the continuous direction of the embankment, and the head of the first steel sheet pile wall is positioned on the ground surface on the one side from the embankment or on the one side of the embankment. The first steel sheet pile wall may be protruded upward from the surface or the small step, or the first steel sheet pile wall on the other side of the slope on the other side of the embankment and the shoulder of the slope closest to the top. is provided along the continuous direction of the embankment, and the head of the first steel sheet pile wall is protruded above the ground surface on the other side of the embankment or the slope or bench on the other side of the embankment. good too.
Furthermore, the first steel sheet pile walls may be provided on both slope sides of the embankment as described above. Then, the head of the first steel sheet pile wall may dam earth and sand due to slope collapse on the one side, the other side, or both sides of the embankment.

10 embankment (embankment)
11 crest 12, 13 slope 12a upstream slope shoulder 13a downstream slope shoulder 13e downstream slope bottom 16, 17 small step 20 first steel sheet pile wall 20b head 25 second steel sheet pile wall GS ground surface

Claims (6)

A continuous embankment structure,
Of the two slopes on one side and the other side across the top of the embankment, at least on the one side of the slope and on the one side of the slope closest to the top of the slope. A steel sheet pile wall is provided along the continuous direction of the embankment, and the head of the first steel sheet pile wall is positioned above the ground surface on the one side of the embankment, the slope on the one side of the embankment, or the bench. protrude,
The head of the first steel sheet pile wall dams the earth and sand due to the slope collapse of the slope on the one side of the embankment ,
When water exists on the other side, the other side is the upstream side, and the one side is the downstream side,
The first steel sheet pile wall is located on the downstream side of the downstream slope shoulder located on the most upstream side of the embankment, and the head of the first steel sheet pile wall is positioned on the ground surface on the downstream side of the embankment or on the An embankment structure, characterized in that the embankment is arranged in a state of protruding upward from the slope or bench on the downstream side of the embankment. 2. The embankment structure according to claim 1, wherein a second steel sheet pile wall is provided at the crest of said embankment along the continuous direction of said embankment. The first steel sheet pile wall is provided on the downstream side slope toe of the embankment, and the second steel sheet pile wall is provided on the upstream side slope shoulder of the crest of the embankment,
The projection length of the head of the first steel sheet pile wall is h (m), the width of the top end is B (m), the height of the embankment is H (m), and the slope angle on the downstream side of the embankment is θ and
3. The embankment structure according to claim 2 , wherein the following formula (1) is satisfied.

The first steel sheet pile wall is provided on the ground surface downstream from the embankment, and the second steel sheet pile wall is provided on the upstream slope shoulder of the crest of the embankment,
The projection length of the head of the first steel sheet pile wall is h (m), the width of the top end is B, the height of the embankment is H (m), the slope angle on the downstream side of the embankment is θ, the third 1 If the horizontal distance between the steel sheet pile wall and the bottom of the slope on the downstream side of the embankment is b (m),
3. The embankment structure according to claim 2 , wherein the following formula (2) is satisfied.

The first steel sheet pile wall is provided on the slope on the downstream side of the embankment, and the second steel sheet pile wall is provided on the upstream slope shoulder of the crest of the embankment,
The projection length of the head of the first steel sheet pile wall is h (m), the width of the top end is B (m), the height of the embankment is H, the slope angle on the downstream side of the embankment is θ, the third 1 If the horizontal distance between the steel sheet pile wall and the bottom of the slope on the downstream side of the embankment is b (m),
3. The embankment structure according to claim 2 , wherein the following formula (3) is satisfied.

The embankment according to any one of claims 2 to 5 , wherein at least one of the first steel sheet pile wall and the second steel sheet pile wall is provided with a permeable steel sheet pile. structure.

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