Embankment and construction method for embankment

Abstract

To improve the strength of a core portion in an embankment having double wall bodies, by enhancing workability by reducing construction space and shortening the construction period, and also contribute to CO2 reduction.SOLUTION: An embankment is provided, the embankment comprising: an embankment body; first and second wall bodies cast into the embankment body and extending in the longitudinal direction of the embankment; and logs cast into the embankment body between the first and second wall bodies.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a levee and a method for constructing a levee. [Background technology]

[0002] There are concerns about the risk of river, coastal, and reservoir levees being breached or destroyed due to cracks or subsidence in the levee body caused by earthquakes, or erosion of the levee body caused by overflow during floods. Patent Document 1, for example, describes a reinforcing structure for levees in which steel sheet pile walls are cast into the shoulders of the embankment on both sides of the width of the levee body, extending in the same direction as the levee body, and the tops of each steel sheet pile wall are connected with ties. This type of reinforcing structure using double steel sheet pile walls is known to be effective as a liquefaction countermeasure, since the two rows of steel sheet pile walls suppress soil deformation and movement during an earthquake. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-13451 Summary of the Invention [Problem to be solved by the invention]

[0004] In levees with walls like the double steel sheet pile wall mentioned above, the strength of the portion of the levee between the walls (hereinafter referred to as the core) affects the stability of the entire structure. For example, the strength of the core can be improved by using ground improvement methods that use cement, but it is not always easy to secure large construction yards around the levee for the cement plants and heavy construction equipment required for ground improvement methods. Furthermore, reducing CO2 emissions as a measure against global warming is also an important issue in the construction industry, and there is particularly great room for improvement in ground improvement methods, which emit large amounts of CO2 due to the fuel consumption of large heavy equipment.

[0005] Therefore, the present invention aims to provide a levee and a levee construction method that can improve the strength of the core part of a levee with double walls, thereby improving workability by reducing the construction space and shortening the construction period, and also contributing to reducing CO2 emissions. [Means for solving the problem]

[0006] [1] A levee comprising a levee body, first and second walls driven into the levee body and extending in the extension direction of the levee, and logs driven into the levee body between the first and second walls. [2] The embankment described in [1], further comprising a connecting member connecting the heads of the first and second wall bodies. [3] The embankment according to [1] or [2], wherein at least some of the logs are driven deeper than the first and second walls. [4] A levee described in [1] or [2], wherein at least one of the first and second walls or at least a portion of the logs is driven down to the supporting layer of the ground on which the levee is constructed. [5] A levee described in [1] or [2], in which at least some of the logs are driven deeper than the passive collapse line of the levee body drawn from the lower end or zero displacement point of the first wall body toward the second wall body. [6] A levee described in [1] or [2], in which at least some of the logs are driven deeper than the active collapse line of the levee body drawn from the lower end of the second wall or the zero displacement point toward the first wall. [7] The embankment described in [1] or [2], wherein the logs include a first log driven deeper than the passive collapse line of the embankment body drawn from the lower end or zero displacement point of the first wall toward the second wall, and an active collapse line of the embankment body drawn from the lower end or zero displacement point of the second wall toward the first wall, between the first wall and the intersection of the passive collapse line and the active collapse line, and a second log driven deeper than the active collapse line between the intersection and the second wall. [8] The embankment described in [1] or [2], wherein the logs include a first log driven deeper than the first passive collapse line of the embankment body drawn from the lower end or zero displacement point of the first wall toward the second wall, and a second passive collapse line of the embankment body drawn from the lower end or zero displacement point of the second wall toward the first wall, between the first wall and the intersection of the first passive collapse line and the second passive collapse line, and a second log driven deeper than the second passive collapse line between the intersection and the second wall. [9] The embankment described in [1] or [2], wherein the logs include logs connected to the head of at least one of the first wall body or the second wall body and driven diagonally to the vertical direction.

[10] The embankment described in [1] or [2], further comprising a cross member connecting the head of the first or second wall body to at least a portion of the log.

[11] A levee described in [1] or [2], wherein the carbon storage amount of the logs per unit length of the levee is equal to or greater than the carbon emissions from heavy machinery during the construction of the first and second walls.

[12] A method for constructing a levee as described in [1], comprising the steps of excavating the levee body to form pile holes, and driving the logs into the pile holes.

[13] A method for constructing a levee as described in [2], comprising the step of installing the connecting material and then driving the logs.

[14] A method for constructing a levee according to

[13] , which does not include a step of excavating the levee body to form pile holes.

[15] A method for constructing a levee according to

[13] or

[14] , wherein tension is introduced into the connecting material by the step of driving the logs. [Effects of the Invention]

[0007] According to the above-mentioned configuration, by placing logs in the core of the embankment, the resistance of the structure consisting of the core and the first and second walls to sliding and shearing can be increased. The method using logs is easy to implement because it requires less construction space and shortens the construction period compared to, for example, ground improvement methods using cement. Furthermore, the carbon storage capacity of the logs, which are made of wood, can contribute to CO2 reduction. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view showing the structure of a levee according to a first embodiment of the present invention. [Figure 2] FIG. 6 is a schematic cross-sectional view showing the structure of a levee according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a diagram showing an example of the driving depth of a log in an embodiment of the present invention. [Figure 4] FIG. 10 is a diagram showing an example of the driving depth of a log in an embodiment of the present invention. [Figure 5] FIG. 10 is a diagram showing an example of the relationship between the log driving depth and the passive collapse line of the embankment in an embodiment of the present invention. [Figure 6] FIG. 10 is a diagram showing an example of the relationship between the log driving depth and the passive collapse line and active collapse line of the embankment in an embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing an example of the relationship between the log driving depth and the passive collapse line of the embankment in an embodiment of the present invention. [Figure 8] FIG. 10 is a diagram showing an example of the relationship between the log driving depth and the passive collapse line of the embankment in an embodiment of the present invention. [Figure 9] 10A and 10B are diagrams illustrating examples of further reinforcing structures in embodiments of the present invention. [Figure 10] 10A and 10B are diagrams illustrating examples of further reinforcing structures in embodiments of the present invention. [Figure 11] FIG. 10 is a diagram for explaining the definition of an improvement rate. [Figure 12] 10 is a graph showing the relationship between the improvement rate calculated by analysis and the horizontal displacement of the steel sheet pile head when scouring occurs. [Figure 13] 10 is a graph showing the relationship between the unit volume weight of the core calculated by analysis and the horizontal displacement of the steel sheet pile head when scouring occurs. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0010] FIG. 1 is a schematic cross-sectional view showing the structure of a levee according to a first embodiment of the present invention. In this embodiment, a levee 10A includes a levee body 11, steel sheet pile walls 12 and 13 driven into the slope of the levee body 11, and logs 15 driven between the steel sheet pile walls 12 and 13, i.e., into the core portion 11C of the levee body 11. The steel sheet pile walls 12 and 13 are examples of first and second walls extending in the extension direction of the levee 10A (the depth direction in the figure), and in other embodiments, they may be concrete walls or the like. The logs 15 may be made by joining pieces of wood together with nails or adhesive.

[0011] The above-described embankment 10A is constructed, for example, by drilling between the steel sheet pile walls 12, 13 to form pile holes and driving logs 15 into the pile holes. The embankment including the embankment body 11 and the steel sheet pile walls 12, 13 may already be constructed, and only driving the logs 15 may be performed as a step to reinforce the embankment. Alternatively, the embankment including only the embankment body 11 may already be constructed, and driving the steel sheet pile walls 12, 13 and driving the logs 15 may be performed as a step to reinforce the embankment. Furthermore, the embankment 10A including the embankment body 11, the steel sheet pile walls 12, 13, and the logs 15 may be newly constructed through a series of steps.

[0012] In the embankment 10A according to this embodiment, by driving logs 15 into the core 11C of the embankment body 11, the resistance to sliding and shear of the structure formed by the core 11C and the steel sheet pile walls 12, 13 can be increased. More specifically, the ground in the core 11C is sandwiched between the steel sheet pile walls 12, 13, and ground movement toward the steel sheet pile walls 12, 13 is easily restricted. By driving logs 15 into the core 11C and spreading the surrounding ground, the density of the ground between the periphery of the logs 15 and the steel sheet pile walls 12, 13 is increased, thereby improving the strength of the core 11C. Furthermore, the provision of logs 15 increases the ground strength near the steel sheet pile walls 12, 13, thereby enhancing the ground resistance at the embedded portions of the steel sheet pile walls 12, 13. Furthermore, because the shear stiffness and shear resistance of the soil where the density has increased are increased, the overall stability of the structure can be improved, or the cross-sectional performance required for the steel sheet pile walls 12, 13, which are supported by the resistance of the soil, can be reduced. Thus, the present invention simplifies the structure by shortening the embedded length of walls such as the steel sheet pile walls 12, 13, or by using materials with lower stiffness, which means that the wall specifications can be set lower, leading to reduced costs for wall materials. From this perspective, the planar arrangement of the logs 15 does not necessarily need to be uniform; it is more effective to arrange the logs 15 more densely in areas close to the steel sheet pile walls 12, 13.

[0013] In particular, for levees with a narrow crest width, i.e., a narrow core width, the shear strength of the core is relatively low, so reinforcing the core with logs is particularly effective for such levees. A similar effect can be achieved by ground improvement methods, but the method of this embodiment using logs is advantageous in that it does not require a large construction yard and is simpler to implement. Another advantage of this embodiment is that logs and the wood chips used to make them are easy to stockpile, making it easy to respond to urgent reinforcement work, such as disaster recovery work.

[0014] In this embodiment, the carbon offset effect can also be achieved by utilizing the carbon storage capacity of the logs, which are wood. For example, the diameter and spacing of the logs may be set so that the carbon storage capacity of the logs 15 per unit length in the dike 10A's extension direction is equal to or greater than the carbon emissions from the heavy machinery used to install the steel sheet pile walls 12 and 13. It may also be possible to carbon-neutralize the dike reinforcement work, including the manufacturing process of the steel sheet piles used in the steel sheet pile walls 12 and 13. Even if this is not possible, it is possible to significantly reduce carbon emissions throughout the entire dike reinforcement work, including emissions from the manufacturing of wall materials and from the heavy machinery used to install them.

[0015] In addition, when logs 15 are driven into pile holes formed by drilling holes in the embankment body 11 of the embankment 10A, the weight of the core of the embankment body 11 is reduced. In other words, by replacing part of the core with logs 15, the weight per unit volume (density) becomes smaller than when the core is formed of soil alone, and the load on the steel sheet pile walls 12, 13 is reduced. Therefore, it becomes possible to construct the steel sheet pile walls 12, 13 using steel sheet piles with lower specifications, i.e., steel sheet piles with a relatively small cross-sectional area, which not only reduces costs but also reduces carbon emissions during steel sheet pile manufacturing.

[0016] 2 is a schematic cross-sectional view showing the structure of a levee according to a second embodiment of the present invention. In this embodiment, in addition to the configuration of the levee 10A described above, the levee 10B includes tie members 14 connecting the heads of the steel sheet pile walls 12, 13. The tie members 14 are an example of connecting members connecting the heads of the first and second wall bodies. In other embodiments, the tie members 14 may be other members capable of transmitting tensile and shear forces between the heads of the wall bodies, such as steel walls installed perpendicular to the wall bodies or concrete top plates poured across the heads of the wall bodies.

[0017] The above-described embankment 10B is constructed, for example, by installing tie members 14 connecting the heads of the steel sheet pile walls 12, 13, and then driving logs 15 between the steel sheet pile walls 12, 13, i.e., into the core of the embankment body 11. As with the above-described embankment 10A, the process of reinforcing the embankment may involve only driving the logs 15, or may involve driving the steel sheet pile walls 12, 13, installing the tie members 14, and driving the logs 15. Alternatively, the embankment 10B including the embankment body 11, the steel sheet pile walls 12, 13, the tie members 14, and the logs 15 may be newly constructed through a series of processes.

[0018] Like the levee 10A described above, the levee 10B according to this embodiment can also enhance the sliding and shear resistance of the structure composed of the core of the levee body 11 and the steel sheet pile walls 12 and 13. The advantages of the logs 15, such as ease of construction, ease of stockpiling, and carbon offsetting, are also similar. Additionally, in the levee 10B, the logs 15 are driven into the core of the levee body 11 between the steel sheet pile walls 12 and 13, thereby compacting the soil. Therefore, when driving the logs 15 in the levee 10B, the process of excavating the levee body 11 to form pile holes can be omitted. Alternatively, even if pile holes are formed, the holes can be smaller than those in the levee 10A. For example, driving the logs 15 near the steel sheet pile walls 12 and 13 may push the soil in the core of the levee body 11 outward, thereby introducing tensile force into the tie members 14. Therefore, the tensile force introduced into the tie material 14 before and after the driving of the log 15 can be measured using a strain gauge or optical fiber, and this can be used as an indicator of whether the soil in the core area is compacted.

[0019] On the other hand, in the construction of the embankment 10B, it is also possible to excavate the core of the embankment body 11 to form sufficiently large pile holes and drive logs 15 into the pile holes. In this case, the soil compaction effect described above is not obtained or is reduced, but instead, the effect of reducing the density in the core of the embankment body 11 is obtained, as in the case of the embankment 10A. In this case, the logs 15 may be driven before the tie materials 14 are installed.

[0020] In the following, other embodiments of the present invention will be described mainly based on the embankment 10A according to the first embodiment, but a similar configuration is also possible for the embankment 10B according to the second embodiment.

[0021] 3 and 4 are diagrams showing examples of the driving depth of logs in an embodiment of the present invention. In the examples of FIGS. 1 and 2, all of the logs 15 are driven shallower than the steel sheet pile walls 12, 13. However, at least some of the logs 15 may be driven deeper than the steel sheet pile walls 12, 13. Specifically, as in the example of FIG. 3, all of the logs 15 may be driven deeper than the steel sheet pile walls 12, 13, or as in the example of FIG. 4, only some of the logs 15 may be driven deeper than the steel sheet pile walls 12, 13. As an example of the driving depth, at least one of the steel sheet pile walls 12, 13 or at least some of the logs 15 may be driven down to the bearing layer of the ground on which the cut-off wall 11 is constructed.

[0022] 5 to 8 are diagrams illustrating examples of the relationship between the log driving depth and the passive or active collapse line of the embankment body in an embodiment of the present invention. When the steel sheet pile wall 12 faces the water body side of a river levee, the core receives unbalanced water pressure from the steel sheet pile wall 12 side during flooding. To increase resistance to passive collapse due to unbalanced water pressure, as shown in the example of FIG. 5, at least some of the logs 15 may be driven deeper than the passive collapse line PL of the embankment body 11, which is drawn from the lower end of the steel sheet pile wall 12 toward the steel sheet pile wall 13. Similarly, to increase resistance to active collapse due to unbalanced water pressure, at least some of the logs 15 may be driven deeper than the active collapse line PL of the embankment body 11, which is drawn from the lower end of the steel sheet pile wall 13 on the side opposite the water body toward the steel sheet pile wall 12.

[0023] Figure 6 shows an example of combining the above two configurations. Figure 6 shows a passive collapse line PL of the embankment body 11, drawn from the lower end of the steel sheet pile wall 12 toward the steel sheet pile wall 13; an active collapse line AL of the embankment body 11, drawn from the lower end of the steel sheet pile wall 13 toward the steel sheet pile wall 12; and an intersection CP1 between the passive collapse line PL and the active collapse line AL. The logs 15 include a first log 15A driven deeper than the passive collapse line PL between the steel sheet pile wall 12 and the intersection CP1; and a second log 15B driven deeper than the active collapse line AL between the intersection CP1 and the steel sheet pile wall 13. This configuration increases resistance to both passive and active collapse due to unbalanced soil pressure.

[0024] On the other hand, in the event of an earthquake, the core may be subjected to horizontal seismic forces from both the steel sheet pile wall 12 side and the steel sheet pile wall 13 side. To increase resistance to passive collapse due to seismic forces, at least some of the logs 15 may be driven deeper than the passive collapse lines PL1 and PL2 of the embankment body 11, which are drawn from the lower ends of the steel sheet pile walls 12 and 13, as shown in the example of Figure 7 . Figure 7 shows a passive collapse line PL1 drawn from the lower end of the steel sheet pile wall 12 toward the steel sheet pile wall 13, a passive collapse line PL2 drawn from the lower end of the steel sheet pile wall 13 toward the steel sheet pile wall 12, and an intersection CP2 of the passive collapse lines PL1 and PL2. The logs 15 include a first log 15A driven deeper than the passive collapse line PL1 between the steel sheet pile wall 12 and the intersection CP2, and a second log 15B driven deeper than the passive collapse line PL2 between the intersection CP2 and the steel sheet pile wall 13. This increases resistance to passive collapse in both directions due to seismic forces.

[0025] In the above example, the passive collapse lines PL, PL1, PL2 and the active collapse line AL of the embankment body 11 are drawn from the lower end of the steel sheet pile wall 12 or 13. However, as in the example of Fig. 8, the passive collapse line PL of the embankment body 11 may be drawn from the zero displacement point ZP calculated at the lower end of the steel sheet pile wall 12 or 13. The same applies to the passive collapse lines PL1, PL2 and the active collapse line AL. The zero displacement point ZP is the point at which the displacement of the steel sheet pile wall in the width direction of the embankment body, which is determined in design by the balance between the soil-water pressure acting on the wall and the wall rigidity, converges to almost zero.

[0026] 9 and 10 are diagrams illustrating examples of further reinforcement structures according to an embodiment of the present invention. Deformation of the steel sheet pile walls 12, 13 caused by the above-mentioned uneven soil pressure and seismic force may lead to the collapse of the core. Therefore, as shown in the example of FIG. 9 , the logs 15 may include, in addition to the logs 15C driven vertically, logs 15D connected to the head of the steel sheet pile wall 12 and driven at an angle to the vertical. This allows the compressive force of the logs 15C to resist deformation of the head of the steel sheet pile wall 12. Similarly, the steel sheet pile wall 13 may include a log 15E connected to the head of the steel sheet pile wall 13 and driven at an angle to the vertical. These logs 15D, 15E and the heads of the steel sheet pile walls 12, 13 are preferably connected by pin connections, for example, by drilling holes and threading wires through them.

[0027] In the example of FIG. 10 , a cross member 16 is provided to connect the head of the steel sheet pile wall 12 to at least a part of the log 15. The cross member 16 may be, for example, a wooden member like the log 15, or a steel or resin member. The steel sheet pile wall 12 and the cross member 16, and the cross member 16 and the log 15 are connected by, for example, drilling holes and passing wire through them to fasten them together. Providing the cross member 16 also increases the resistance to deformation of the head of the steel sheet pile wall 12. A similar cross member may also be provided on the steel sheet pile wall 13 side. [Example]

[0028] Below, we will explain the results of an analytical study using the ground analysis software PLAXIS on the effect of reinforcement by driving logs into the core of the cut-off wall. As shown in Figure 11, the improvement rate α S =πD 2 / 4B 2 Calculate the improvement rate α according to "Verification of the effect of ground improvement on coastal reclaimed land by driving logs Part 2 Sounding test results" (Hara Tadashi et al., November 2014, Shikoku Branch of the Geotechnical Society) S was converted into an increment in N value. Note that pile holes were not formed.S = 0), the internal friction angle φ = 25°, the adhesive force c = 1.0 kPa, and the improvement rate α S The analysis was conducted assuming that the internal friction angle φ changes in response to the increase in N-value due to an increase in the water level. In the analysis, the horizontal displacement of the head of the steel sheet pile on the back side of the river was calculated when scouring occurs on the back side of the river (opposite the water area) due to an increase in the water level of the river levee, causing the levee body to be washed away. In addition, when a typical log diameter D = 0.2 m is considered, the improvement rate α S ≒1%, improvement rate α at pouring intervals of 0.5 m S ≒15%. Figure 12 is a graph showing the relationship between the improvement rate calculated by analysis and the horizontal displacement of the steel sheet pile head when scouring occurs. As shown in the graph, the improvement rate α S As the horizontal displacement of the head of the steel sheet pile increases, it decreases almost linearly, and it is clear that the driving of logs has a reinforcing effect on the core of the embankment.

[0029] Next, we analyzed the effect of weight reduction when driving logs into pile holes drilled into the dam body. S Instead of converting into an increment in N-value, the unit volume weight γ of the core part of the dam body was changed. Since the density of the logs is smaller than that of the soil, the improvement rate α S The larger the value, the smaller the unit weight of the core γ. S = 0) and unit weight γ = 20 kN / m 3 The analysis was conducted assuming that the unit weight γ of the core part would decrease due to the driving of logs. Figure 13 is a graph showing the relationship between the unit weight of the core part calculated by the analysis and the horizontal displacement of the steel sheet pile head when scouring occurs. As shown in the graph, the unit weight γ of the core part after driving of logs was 20 kN / m 3 to 13kN / m 3 The horizontal displacement of the steel sheet pile head decreases within the range of γ=13kN / m 3 For example, a typical cedar log (air-dry density 0.38 g / cm 3 ) and the improvement rate α S = 40%. As mentioned above, even when logs are placed with a log diameter D = 0.2 m and a placement interval B = 0.5 m, the improvement rate αS ≒ 15%, the above analysis results show that the effect of reducing the core weight can be achieved within the realistic range of log arrangement. As shown in the graph, the improvement rate α S The range in which weight reduction has a particularly large effect is 25% or less.

[0030] Next, we will explain the results of verifying the carbon offset effect of reinforcing the embankment with logs. Table 1 shows the calculation results of the carbon stock per 10m of embankment length when logs are driven into the embankment with a core width of 5m, i.e., the interval between steel sheet pile walls, at various driving intervals B (see Figure 11). The logs driven are larch logs with a length of 6m and a diameter of 0.2m (air-dry density 0.50g / cm). 3 ), and the carbon storage equivalent in CO2 was calculated by multiplying the log mass by the carbon content of lumber (0.5), then multiplying it by 44 / 12 to convert the carbon mass to CO2 mass. In contrast, the CO2 emissions from installing two rows of steel sheet pile walls per 10 m of levee length are calculated as 1.08 t, calculated by multiplying the diesel fuel consumption (412.8 L) for the press-in machine and crawler crane by the diesel CO2 emission coefficient (2.62 kg-CO2 / L). Therefore, even with a relatively low improvement rate, using logs to reinforce the levee body can achieve carbon storage levels greater than those emitted by heavy machinery during installation of the steel sheet pile walls. On the other hand, if the steel sheet piles used for two rows of steel sheet pile walls per 10 m of levee length are manufactured using an electric furnace and rolling process, the CO2 emissions are approximately 13.5 t. Therefore, when the improvement rate is high by reinforcing the embankment with logs, it is possible to achieve a carbon storage amount greater than the carbon emissions during the manufacturing of the steel sheet pile and the installation of the steel sheet pile wall (in this example, 1.08 + 13.5 ≒ 14.6 t). Furthermore, when the improvement rate is high, exceeding 18%, it is possible to achieve a carbon storage amount greater than the CO2 emissions of a steel sheet pile wall manufactured in the steelmaking process using a blast furnace.

[0031] [Table 1] [Explanation of symbols]

[0032] 10A, 10B... embankment, 11... embankment body, 11C... core section, 12, 13... steel sheet pile wall, 14... tie material, 15... logs, 16... cross member.

Claims

1. The embankment and First and second walls are cast into the bank body and extend in the extension direction of the bank; Logs driven into the bank between the first and second walls; A levee equipped with:

2. The embankment of claim 1 further comprising a connector connecting the heads of the first and second walls.

3. 3. The embankment according to claim 1 or claim 2, wherein at least some of the logs are driven deeper than the first and second wall bodies.

4. 3. The embankment according to claim 1 or claim 2, wherein at least one of the first and second wall bodies or at least a portion of the logs is driven down to a bearing layer of the ground on which the embankment is constructed.

5. A levee as described in claim 1 or claim 2, wherein at least some of the logs are driven deeper than the passive collapse line of the levee body drawn from the lower end or zero displacement point of the first wall body toward the second wall body.

6. A levee as described in claim 1 or claim 2, wherein at least some of the logs are driven deeper than the active collapse line of the levee body drawn from the lower end or zero displacement point of the second wall body toward the first wall body.

7. The embankment described in claim 1 or claim 2, wherein the logs include, in relation to a passive collapse line of the embankment drawn from the lower end or zero displacement point of the first wall toward the second wall, and an active collapse line of the embankment drawn from the lower end or zero displacement point of the second wall toward the first wall, a first log that is driven deeper than the passive collapse line between the first wall and the intersection of the passive collapse line and the active collapse line, and a second log that is driven deeper than the active collapse line between the intersection and the second wall.

8. The embankment described in claim 1 or claim 2, wherein the logs include, in relation to a first passive collapse line of the embankment drawn from the lower end or zero displacement point of the first wall toward the second wall, and a second passive collapse line of the embankment drawn from the lower end or zero displacement point of the second wall toward the first wall, a first log that is driven deeper than the first passive collapse line between the first wall and the intersection of the first passive collapse line and the second passive collapse line, and a second log that is driven deeper than the second passive collapse line between the intersection and the second wall.

9. 3. The embankment according to claim 1 or claim 2, wherein the logs include logs connected to the head of at least one of the first wall body or the second wall body and driven in at an angle to the vertical direction.

10. The embankment according to claim 1 or claim 2, further comprising a cross member connecting the head of the first or second wall body to at least a part of the log.

11. A levee as described in claim 1 or claim 2, wherein the carbon storage amount of the logs per unit length in the levee extension direction is equal to or greater than the carbon emissions caused by heavy machinery when pouring the first and second wall bodies.

12. The embankment construction method according to claim 1, a step of excavating the bank body to form pile holes; driving the logs into the pile holes; and methods of constructing embankments, including:

13. The embankment construction method according to claim 2, A method for constructing a levee, comprising the step of installing the connecting material and then driving the logs.

14. 14. The embankment construction method according to claim 13, which does not include a step of excavating the embankment body to form pile holes.

15. 15. The embankment construction method according to claim 13 or claim 14, wherein tension is introduced into the connecting material by the step of driving the logs.

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