Reinforcement structure of slope structure, and reinforcement method of slope structure

Abstract

To provide a reinforcement structure of slope structures such as embankments and banks, and a reinforcement method of slope structures which can effectively increase ground strength, improve workability by reducing construction space and shortening a construction period, and suppress CO2 emissions.SOLUTION: A reinforcement structure of slope structures comprises steel sheet piles 3 reinforcing embankments 10 having a slope 10a and provided on a slope shoulder 10b; and a plurality of logs 2 provided on the ground G outside the steel sheet pile 3 in an inward / outward direction from the inside to the outside of the embankment 10 in side view. The steel sheet pile 3 is formed from steel materials, and the amount of carbon dioxide stored in all of the plurality of logs 2 is greater than the amount of carbon dioxide emitted during manufacture of the steel sheet pile 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a reinforcement structure for a slope structure and a reinforcement method for a slope structure. [Background technology]

[0002] In the past, in structures such as levees and embankments, where double walls using steel sheet piles or walls such as steel sheet piles are installed at both ends of the slope to reinforce the structure, the ground on the opposite side (outside) of the ground sandwiched between the steel sheet piles supports the wall, which functions to maintain the shape of the levees or embankments during earthquakes and heavy rains, and is one of the factors that determine the stability of the entire levees or embankments. This outer ground can be lost due to erosion by river flow or erosion and scouring by overflowing water, and in such cases the resistance of the ground supporting the walls will be lower than the designed state, which may reduce the stability of the entire structure. Therefore, in order to increase the strength of the ground outside the wall structure, a ground improvement method using concrete or replacing the original ground with improved soil that can increase the ground strength more than the original ground is used (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-179148 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional ground improvement methods, for example with sand compaction piles, the increase in shear resistance is limited, and sufficient ground reinforcement effects cannot be obtained when construction space is limited, leaving room for improvement.In addition, when concrete is used, the installation of a concrete plant is required, and when construction involves earthwork, large pouring machinery is required, so a large construction yard must be secured and the construction period is long, posing problems in terms of workability. Furthermore, reducing CO2 emissions as a measure against global warming is an urgent issue in the construction industry, which emits a lot of CO2, and there was room for improvement in ground improvement methods that require large heavy machinery that consumes a lot of fuel and emits large amounts of CO2.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a reinforcement structure for slope structures such as embankments and embankments, and a reinforcement method for slope structures, which can effectively increase ground strength, improve workability by reducing construction space and shortening construction time, and also contribute to reducing CO2 emissions at construction sites. [Means for solving the problem]

[0006] (1) Aspect 1 of the reinforcement structure for a slope structure according to the present invention is a reinforcement structure for a slope structure that reinforces a slope structure having a slope made of ground, and is characterized by comprising a wall body provided at the slope shoulder or slope toe, and a plurality of logs provided in the ground outside the wall body in an inward-outward direction from the inside to the outside of the slope structure when viewed from the side.

[0007] Therefore, in this invention, since the ground is divided by the wall, lateral movement of the ground is easily restricted. Therefore, by placing logs in the ground and spreading the surrounding ground, the density of the ground between the logs and the wall increases, which has the effect of improving the ground strength. Furthermore, the inclusion of logs increases the resistance of the embedded portion of the wall, improving seismic resistance and allowing the embedded length to be relatively shorter compared to conventional reinforcement structures without logs. Furthermore, the inclusion of logs increases the strength of the ground near the wall, increasing the ground resistance of the embedded portion of the wall, improving seismic resistance and allowing the embedded length to be relatively shorter compared to conventional reinforcement structures without logs. Furthermore, because the shear stiffness and shear resistance of the increased density ground increase, it becomes possible to lower the cross-sectional performance required of the wall supported by the resistance force from the ground. Thus, the present invention simplifies the structure by shortening the embedded length of the wall or changing the wall to a lower rigidity type, which means that the wall specifications can be set lower and leads to cost reductions in wall materials.

[0008] In addition, in this invention, by using dried wood as logs, water is absorbed from the surrounding ground after the logs are installed, which reduces the pore water pressure in the surrounding ground, increases the unsaturated ground area, and increases the strength of the entire ground. Furthermore, when materials manufactured in factories are used as reinforcement, a certain production period may be required after receiving an order, and they may need to be stored indoors to ensure quality. However, logs, due to their shape, can be easily stacked and stored, resulting in good space-saving efficiency. They can also be stored outdoors, and no storage building is required, making them suitable for stockpiling as a regular lumber supply, allowing materials to be delivered as needed and supplied immediately when needed, such as in disaster response, and allowing for more flexible response to construction period conditions than conventional construction methods. Furthermore, in this invention, the ground that contributes to the stability of the wall is reinforced with logs, so all that is needed is space for heavy machinery to drive the logs into the ground, which has the advantage of eliminating the need for a large construction yard as in the case of ground improvement methods.

[0009] Furthermore, when the logs of the reinforcement structure of this invention are installed on the river-front slope of a levee, for example, the ground is confined between the logs, which prevents the ground from being washed away by water currents, improving the effectiveness of preventing erosion of the river-front slope by river water and improving the resilience of the reinforcement structure because erosion is kept to a minimum.In addition, because the logs bear the water pressure, the water pressure acting on the wall can be reduced, and the specifications required for the wall, such as rigidity, can be reduced. Furthermore, if the logs of the reinforcing structure of this invention are installed on the riverside slope of a levee, for example, when water overflows the levee from the riverside slope to the riverside slope, it is possible to suppress the flow of water seeping into the ground and reduce the amount of scouring of the riverside slope.Furthermore, by installing the logs on the riverside slope, it is possible to increase the passive earth pressure of the ground supporting the wall, thereby reducing the specifications such as rigidity required for the wall.

[0010] Furthermore, the present invention has the advantage that carbon dioxide absorbed from the atmosphere by multiple logs can be stored inside the ground, which contributes to reducing CO2 emissions at construction sites and contributing to carbon neutrality.

[0011] (2) A second aspect of the present invention is characterized in that, in the reinforcement structure for a slope structure of the first aspect, the lower end of at least one of the plurality of logs is deeper than the lower end of the wall body.

[0012] In the present invention, the logs reach deeper into the ground beyond the lower end of the wall, steadily increasing the shear rigidity and shear resistance of the ground portion around the lower part of the wall, which is particularly important for supporting the wall. This makes it possible to further reduce the earth pressure acting on the wall from the ground behind it, and increase the ground resistance supporting the wall, particularly in cases where there is a thick accumulation of soft ground, thereby reducing the length and rigidity required for the wall.

[0013] (3) Aspect 3 of the present invention is characterized in that, in the reinforcement structure of a slope structure of aspect 1 or aspect 2, the wall is formed of steel, and the amount of carbon dioxide stored in all of the multiple logs is greater than the amount of carbon dioxide emitted during the manufacturing of the wall.

[0014] In the present invention, the amount of carbon dioxide stored in all of the multiple logs is greater than the amount of carbon dioxide emitted during the manufacturing of the wall, which leads to a reduction in the amount of CO2 in the atmosphere and provides an environmentally friendly reinforcement structure for slope structures.

[0015] (4) Aspect 4 of the present invention is characterized in that, in the reinforcement structure of any one of aspects 1 to 3 of a slope structure, the lower end of the log is located at a position deeper than a passive collapse line drawn from the lower end of the wall body toward the outside of the slope at a passive collapse angle.

[0016] In the present invention, logs cross the passive collapse line, and the shear resistance of the logs, which are larger than the ground, is added, so the shear resistance of the entire passive collapse line can be increased.In addition to the effect of increasing ground strength due to the increase in density of the surrounding ground caused by the installation of logs, the ground strength that efficiently supports the wall can be improved.

[0017] (5) Aspect 5 of the present invention is characterized in that, in the reinforcement structure of a slope structure of any one of aspects 1 to 4, the logs are inclined so as to extend downward from the head of the wall body toward the outside of the wall body.

[0018] In this invention, in order to maintain the top height position of the slope structure during an earthquake or heavy rain, the head of the wall is supported by an inclined log, and the load that would deform the head of the wall outward from the slope structure is resisted by the compressive force caused by the tension in the log, thereby suppressing the outward deformation of the wall slope structure.

[0019] (6) Aspect 6 of the present invention is characterized in that, in the reinforcement structure of a slope structure of any one of aspects 1 to 5, at least one of the wall body and the log is driven to a position deeper than the liquefaction layer.

[0020] In the present invention, by driving the lower ends of the wall and logs into stronger ground deeper than the liquefaction layer where liquefaction will not occur, the wall can be made to have increased resistance to the soil and water pressure acting from the liquefaction layer, and the logs can be made to have increased strength in the surrounding ground across the entire thickness of the liquefaction layer, and can be kept in place without their installation position being affected by the load from the liquefaction layer.

[0021] (7) A seventh aspect of the present invention is characterized in that in the reinforcement structure for a slope structure of any one of the first to sixth aspects, the head of the log and the head of the wall body are connected.

[0022] In the present invention, by connecting the head of the log to the wall body, when installing part or all of the log below the groundwater level, the wall body can provide a reaction force to prevent the log from floating up due to buoyancy, thereby preventing the log from moving or being washed away.

[0023] (8) Aspect 8 of the present invention is characterized in that, in the reinforcement structure of a slope structure of any one of aspects 1 to 7, the slope structure has the slope on both sides in the width direction, and the log is installed on one of the slopes on both sides in the width direction.

[0024] In this invention, the above-mentioned effect can be obtained even if logs are provided on only one of the slopes on both sides in the width direction. In particular, when the slope structure is made of uneven ground and only the river side or the back side needs to be reinforced, reinforcement costs can be reduced.

[0025] (9) Aspect 9 of the reinforcement method for a slope structure according to the present invention is a reinforcement method for constructing a reinforcement structure for a slope structure according to any one of aspects 1 to 8, characterized in that it comprises the steps of providing the wall body at the slope shoulder or the slope toe, and providing a plurality of logs in the ground outside the wall body on the slope.

[0026] In the present invention, a reinforcement structure for a slope structure can be constructed that can achieve the effects of the first aspect described above. [Effects of the Invention]

[0027] The reinforcement structure for slope structures and the reinforcement method for slope structures of the present invention can effectively increase ground strength, improve workability by reducing construction space and shortening construction time, and suppress CO2 emissions. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a side view showing a reinforcement structure for an embankment according to a first embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a partial perspective view of the reinforcing structure shown in FIG. [Figure 3] FIG. 2 is an enlarged view showing the head of a log in the reinforcing structure shown in FIG. 1. [Figure 4] FIG. 10 is a side view showing a reinforcing structure for an embankment according to a first modified example. [Figure 5] (a) and (b) show the relationship between the improvement rate and CO2 storage capacity in logs. [Figure 6] FIG. 10 is a side view showing a reinforcing structure according to a second modified example. [Figure 7] FIG. 10 is a side view showing a reinforcing structure according to a third modified example. [Figure 8] FIG. 10 is a partial perspective view of another reinforcing structure. [Figure 9] 10(a) and 10(b) are plan views showing a reinforcing structure according to a fourth modified example. [Figure 10] FIG. 10 is a partial perspective view of a reinforcing structure according to a fifth modified example. [Figure 11] 11 is a side view showing the connection state between the logs and the connecting horizontal members of the reinforcing structure shown in FIG. 10. FIG. [Figure 12] FIG. 10 is a side view showing a reinforcing structure according to a second embodiment. [Figure 13] FIG. 13 is a side view showing a reinforcing structure according to a sixth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, a reinforcement structure for a slope face structure and a reinforcement method for a slope face structure according to an embodiment of the present invention will be described with reference to the drawings.

[0030] (First embodiment) As shown in Figure 1, the reinforcement structure 1 for a slope structure according to this first embodiment is a reinforcement structure in which a levee 10 (slope structure) having slopes 10a on both sides is reinforced with a plurality of logs 2. The levee 10 may be an existing structure, or may be applied to a newly constructed structure in which a plurality of logs 2 are constructed at the same time. The slope structure is not limited to the levee 10 exemplified in this first embodiment, and can be applied to structures having embankment or cut slopes.

[0031] The reinforcing structure 1 of the embankment 10 includes a steel sheet pile 3 (wall) installed at the shoulder 10b, and a plurality of logs 2 installed in the ground Ga outside the steel sheet pile 3 in the inward-outward direction from the inside to the outside of the embankment 10 in a side view. The symbol G in Fig. 1 indicates the entire ground.

[0032] Here, the embankment 10 has slopes 10a, 10a on both sides of the top surface 10d when viewed in cross section as shown in Figure 1. In the embankment 10, the normal direction perpendicular to the extension direction Y is the width direction X (the inward / outward direction described above), and the side toward the center of the embankment in the width direction X is the inside, and the opposite side is the outside. In other words, the slope 10a is located outside the slope shoulder 10b and inside the slope toe 10c.

[0033] The steel sheet piles 3 are buried in the ground G at the slope shoulder 10b and extend along the extension direction Y. The steel sheet piles 3 are, for example, hat-shaped steel sheet piles, and are constructed by driving multiple steel sheet piles into the ground G continuously and integrally in the extension direction Y.

[0034] The logs 2 are made of wood such as larch. The logs 2 have a substantially circular cross section and are driven into the ground G on both sides of the slope 10a in the width direction. Multiple logs 2 are spaced apart in the vertical direction Z along the slope of the slope 10a (see Figure 2). The diameter and overall length of the logs 2 can be changed as needed. As shown in Figure 3, the heads 2a of the logs 2 may have inclined end faces 2c that match the slope angle of the slope 10a. As shown in Figure 2, the lower ends 2b of the logs 2 are preferably sharpened to facilitate penetration into the ground G. The logs 2 can be made from thinned or main-cut timber, or they may be made by combining pieces of wood and nailing or gluing them together. Note that in figures other than Figure 2, the lower ends 2b of the logs 2 are shown bluntly for clarity.

[0035] The multiple logs 2 are arranged in a staggered pattern in plan view (see Figure 9(a)). Maintaining a constant distance between the logs is preferable to uniformly increase the strength of the ground around the logs, which also facilitates construction management. When installing logs on an existing embankment, the strength of the surrounding ground increases as the logs are installed, which increases the driving resistance when the logs are driven into the ground. Therefore, by spacing the logs evenly, it is possible to avoid local increases in ground strength and driving resistance, and to drive the logs into the ground with a constant construction machine load. The arrangement of the multiple logs 2 is not limited to a staggered pattern; they may be arranged at regular intervals both vertically and horizontally in plan view (see Figure 9(b)), or they may be arranged to form a lattice pattern.

[0036] Furthermore, the log 2 is not limited to one with a circular cross section, and it is also possible to use wood with an angular cross section such as a rectangular cross section.

[0037] At least one of the steel sheet piles 3 and the logs 2 is driven to a position deeper than the liquefaction layer. In the reinforcement structure 1 shown in Figure 1, the lower ends 2b of multiple logs 2 are located deeper than the lower ends 3b of steel sheet piles 3 installed at the slope shoulder 10b. By positioning the lower ends of the logs 2 deeper than the lower ends of the steel sheet piles, it is possible to maintain high ground strength even if the ground at the slope toe is partially lost due to erosion caused by overflow water. Note that, although the lower ends 2b of all logs 2 are deeper than the lower ends 3b of the steel sheet piles 3 in Figure 1, only some of the logs 2 may be deeper than the lower ends 3b of the steel sheet piles 3.

[0038] 4, depending on the ground conditions, the lower end 3b of the steel sheet pile 3 may be located deeper than the lower end 2b of the log 2. In cases where it is necessary to increase the ground strength only in a relatively shallow layer of ground around the steel sheet pile, it is not necessary to lengthen the log to match the length of the steel sheet pile, and it is preferable to appropriately select the log length so as to minimize costs depending on the installation location.

[0039] The number of logs 2 is set so that the total amount of carbon dioxide (CO2) stored in each log 2 (CO2 storage amount) is greater than the amount of CO2 emitted during the manufacture of the steel sheet pile 3. In other words, the amount of CO2 stored in each log 2 can be determined by setting the improvement rate (%) (= log cross-sectional area / planar area of ​​the study area) and log length of each log 2. By using wooden logs 2 in this reinforcement structure 1, CO2 can be stored in the logs 2 for a long period of time as long as they remain intact and do not decay, thereby promoting the reduction of atmospheric CO2. Furthermore, if the steel used in the steel sheet pile walls is manufactured in an electric furnace, for example, and carbon emissions during manufacturing are relatively low, it may be possible to make the embankment reinforcement work carbon-neutral, including the steel sheet pile manufacturing process. Even if this is not the case, carbon emissions from the entire embankment reinforcement work, such as those during the manufacturing of wall materials and from construction machinery, can be significantly reduced. In addition, wood needs air and decay fungi to deteriorate, but these are lacking below or near the groundwater level, so the wood remains healthy. Therefore, this invention, in which logs are driven into soft ground below the groundwater level, is effective for storing CO2.

[0040] Figures 5(a) and (b) and Table 1 are an example showing the relationship between the improvement rate (%) and the CO2 storage amount (t) in a log. Figure 5(b) is a partially enlarged view of Figure 5(a). In Figures 5(a) and (b), "T1" indicates the CO2 emissions caused by heavy machinery fuel, "T2" indicates the CO2 emissions caused by steel sheet pile manufacturing in the blast furnace, and "M" indicates the CO2 storage amount in the log 2. "Heavy machinery fuel" refers to the CO2 emitted from the construction heavy machinery used when driving the steel sheet pile 3 into the ground. Table 1 shows the storage rate (kgCO2 / m) of the log 2. 2 ), carbon stock (t) and CO2 equivalent (t). For example, when diesel is 412.8L and the diesel emission coefficient (kgCO2 / L) is 2.62, the CO2 emissions resulting from heavy machinery fuel use are 0.54t.

[0041] [Table 1]

[0042] From Figures 5(a) and (b) and Table 1, if the improvement rate using logs 2 is about 0.5%, it is possible to store CO2 in logs 2 at the same level as the CO2 emissions from heavy machinery. Furthermore, if the improvement rate using logs 2 is about 15%, it is possible to store CO2 in logs 2 at the same level as the CO2 emissions caused by steel sheet pile manufacturing.

[0043] Next, as a method for reinforcing the embankment 10 described above, first, as shown in Figures 1 and 2, steel sheet piles 3 are driven into predetermined positions in the ground G on the slope shoulder 10b of the embankment 10. Next, a plurality of logs 2 are driven into the ground G on the slope surface 10a using, for example, a construction heavy machine.

[0044] The above-described reinforcement structure 1 for a levee 10 and the reinforcement method for a levee 10 reinforce the levee 10 having a slope 10a. The reinforcement structure 1 for the levee 10 includes a steel sheet pile 3 installed at the slope shoulder 10b, and a plurality of logs 2 installed in the ground G near the steel sheet pile 3 in an inward-outward direction from the inside to the outside of the levee 10 in a side view.

[0045] Therefore, in this embodiment, the ground G is divided by the steel sheet piles 3, so that the lateral movement of the ground Ga is easily restricted. Therefore, by placing the logs 2 in the ground Ga and spreading out the surrounding ground, the density of the ground between the periphery of the logs 2 and the steel sheet piles 3 increases, and the effect of improving the ground strength can be achieved. Furthermore, by providing the logs 2, the resistance of the embedded portion of the steel sheet pile 3 is increased, improving earthquake resistance, and the embedded length can be made relatively shorter compared to conventional reinforcement structures that do not provide the logs 2. In addition, by installing the logs 2, the ground strength in the vicinity of the steel sheet piles 3 can be increased, which increases the ground resistance at the embedded portion of the steel sheet piles 3, improving earthquake resistance, and also allowing the embedded length to be relatively shorter compared to conventional reinforcement structures in which the logs 2 are not installed. Furthermore, because the shear stiffness and shear resistance of the ground portion with increased density increase, it becomes possible to lower the cross-sectional performance required of the steel sheet piles 3, which are supported by the resistance of the ground. In this way, in this embodiment, the structure can be simplified by shortening the embedded length of the steel sheet piles 3 or changing the steel sheet piles 3 to a lower rigidity type, which means that the specifications of the steel sheet piles 3 can be set lower, leading to cost reduction of the wall material.

[0046] In addition, in this embodiment, by using dried wood as the logs 2, the logs 2 absorb water from the surrounding ground after being installed, thereby reducing the pore water pressure in the surrounding ground, increasing the unsaturated ground range, and increasing the strength of the entire ground. Furthermore, when materials manufactured in factories are used as reinforcement, a certain production period may be required after receiving an order, or they may need to be stored indoors to ensure quality. However, due to their shape, logs 2 can be easily stacked and stored, which allows for good space-saving efficiency. They can also be stored outdoors, and no building is required for storage. This makes them suitable for stockpiling as a regular supply of lumber, allowing for materials to be delivered as needed, and materials to be supplied immediately when needed, such as in disaster response, and allowing for more flexible response to construction period conditions than conventional construction methods. Furthermore, in this embodiment, the ground, which contributes to the stability of the steel sheet piles 3, is reinforced with logs 2, so only space for heavy machinery to drive the logs 2 into the ground is required, which has the advantage of eliminating the need for a large-scale construction yard as in the case of ground improvement methods.

[0047] Furthermore, when the logs 2 of the reinforcement structure 1 of this embodiment are installed on the river-front slope of the embankment 10, for example, the ground is constrained between the logs 2, which prevents the ground G from being washed away by water currents, improving the effectiveness of preventing erosion of the river-front slope by river water and minimizing erosion, thereby improving the resilience of the reinforcement structure. Furthermore, because the logs 2 bear the water pressure, the water pressure acting on the steel sheet piles 3 can be reduced, and the specifications required for the steel sheet piles 3, such as rigidity, can be reduced.

[0048] Furthermore, when the logs 2 of the reinforcement structure 1 of this embodiment are installed on the riverside slope of the levee 10, for example, if water overflows the levee from the riverside slope side to the riverside slope side, the flow of water seeping into the ground can be suppressed, and the amount of scouring of the riverside slope can be reduced. Furthermore, by installing the logs 2 on the riverside slope, the passive earth pressure of the ground supporting the steel sheet piles 3 can be increased, and the specifications such as rigidity required for the wall can be reduced.

[0049] Furthermore, in this embodiment, the carbon dioxide absorbed from the atmosphere by the multiple logs 2 can be stored inside the ground, which has the advantage of contributing to CO2 reduction at construction sites and contributing to carbon neutrality.

[0050] In addition, in this embodiment, the lower end of at least one of the multiple logs 2 is deeper than the lower end 3b of the steel sheet pile 3. As a result, the logs 2 reach deeper into the ground beyond the lower end position of the steel sheet pile 3, which can further increase the shear rigidity and shear resistance of the ground portion around the lower part of the steel sheet pile 3, which is particularly important for supporting the wall body. In particular, when there is a thick pile of soft ground, the earth pressure acting on the steel sheet pile 3 from the back ground can be further reduced and the ground resistance supporting the steel sheet pile 3 can be increased, so that the length and rigidity required for the steel sheet pile 3 can be reduced.

[0051] In this embodiment, the steel sheet pile 3 is made of steel. The amount of carbon dioxide stored in all of the multiple logs 2 is greater than the amount of carbon dioxide emitted during the manufacture of the steel sheet pile 3. This configuration leads to a reduction in the amount of CO2 in the atmosphere, as the amount of carbon dioxide stored in all of the multiple logs 2 is greater than the amount of carbon dioxide emitted during the manufacture of the steel sheet pile 3, and it is possible to provide an environmentally friendly reinforcement structure for a slope structure.

[0052] In this embodiment, at least one of the steel sheet piles 3 and the logs 2 is driven to a position deeper than the liquefaction layer. With this configuration, the lower ends of the steel sheet piles 3 and the logs 2 are driven into stronger ground deeper than the liquefaction layer where liquefaction does not occur, thereby increasing the resistance of the steel sheet piles 3 to the soil-water pressure acting from the liquefaction layer, and the strength of the surrounding ground of the logs 2 can be reliably increased throughout the entire thickness of the liquefaction layer, and the logs 2 themselves can be kept in place without being displaced by the load from the liquefaction layer.

[0053] As described above, the reinforcement structure for slope face structures and the reinforcement method for slope face structures according to this embodiment can effectively increase ground strength, improve workability by reducing the construction space and shortening the construction period, and suppress CO2 emissions.

[0054] Next, other embodiments and modifications of the reinforcement structure for slope face structures and the reinforcement method for slope face structures of the present invention will be described based on the attached drawings. However, the same symbols will be used for components and parts that are the same as or similar to those in the first embodiment described above, and explanations will be omitted. Only configurations that differ from the first embodiment will be described.

[0055] (Second Modification) As shown in Figure 6, the reinforcement structure 1B for a slope structure according to the second modification has a structure in which the lower ends 2b of the logs 2 are located deeper than a passive collapse line K drawn from the lower ends 3b of the steel sheet piles 3 toward the ground G outside the embankment 10 at a passive collapse angle. In other words, the logs 2 are driven to a depth at which they intersect with the passive collapse line K extending from the lower ends 3b of the steel sheet piles 3. Note that, although the lower ends 2b of all the logs 2 are deeper than the passive collapse line K in Figure 6, only some of the logs 2 may be deeper than the passive collapse line K.

[0056] In the second modified example, the lengths of some of the logs 2 to be placed can be shortened. Furthermore, in the second modified example, the logs 2 cross the passive collapse line K extending from the steel sheet pile 3, and therefore the shear resistance of the logs 2, which is larger than the ground, is added, thereby increasing the shear resistance of the entire area along the passive collapse line K. In addition to the effect of increasing the ground strength associated with the increase in density of the surrounding ground due to the installation of the logs 2, the ground strength supporting the steel sheet pile 3 can be efficiently improved. Depending on the increase in shear strength along the passive collapse line K required for reinforcement, it is not necessary for the lower ends of all the logs 2 to be in tolerance with the passive collapse line K, and economical reinforcement can be achieved by making only the lower end portions of the necessary number of logs 2 deeper than the passive collapse line K.

[0057] (Third Modification) As shown in Fig. 7, in the reinforcement structure 1C for a slope structure according to the third modification, the log 2 is inclined so that it extends downward from the head 3a of the steel sheet pile 3 toward the outside X2. The head 2a of the inclined log 2 is connected to the head 3a of the steel sheet pile 3. In this case, the connection structure is preferably the pin connection described above. The head 2a of the inclined log 2 and the head 3a of the steel sheet pile 3 do not necessarily have to be connected, as long as a mechanism is in place that allows compressive force to be transmitted from the head 3a of the steel sheet pile 3 to the log 2 that serves as a batter pile. For example, as shown in Fig. 8, in order to suppress displacement of the log 2 toward the steel sheet pile 3 in the longitudinal direction, a member 22 such as an angle bar may be attached to the head 3a of the steel sheet pile 3 so as to hold down the head of the log 2.

[0058] In the reinforcement structure 1C according to the third variant, in order to maintain the top height position of the slope structure during an earthquake or heavy rain, the head 3a of the steel sheet pile 3 is supported by an inclined log 2, and the load that would deform the head 3a of the steel sheet pile 3 outward from the slope structure is resisted by the compressive force caused by the tension in the log 2, thereby suppressing the outward deformation of the slope structure by the steel sheet pile 3.

[0059] (Fourth Modification) As shown in Figures 9(a) and (b), the reinforcement structure 1D for a slope structure according to the fourth modification has logs 2 provided only on one side of the slope 10a. Figure 9(a) shows an example of an arrangement in which multiple logs 2 are arranged in a staggered pattern in plan view. Figure 9(b) shows an example of an arrangement in which multiple logs 2 are arranged at regular intervals both vertically and horizontally in plan view. In order to prevent scouring, it is desirable to arrange the multiple logs 2 in a staggered pattern so as to suppress the runoff of ground between the logs 2. In cases where the area where the slope structure is located is expected to experience heavy rainfall that is so great that a certain amount of scouring is acceptable, it is desirable to arrange the logs 2 in a grid pattern so that overflow water can be quickly discharged in order to reduce the water pressure acting on the logs 2 located at the rear of the rows in the direction of the water flow.

[0060] (Fifth Modification) As shown in Figures 10 and 11, the reinforcement structure 1E for a slope structure according to the fifth modified example has a structure in which a plurality of logs 2 are connected in the width direction X by connecting horizontal members 20 made of wood. The connecting horizontal members 20 are pieces of wood with a circular cross section similar to the logs 2. The connecting horizontal members 20 connect the heads 2a of the plurality of logs 2 to each other.

[0061] As shown in Fig. 10, one end 20a of the connecting horizontal member 20 and the head 3a of the steel sheet pile 3 are joined by a wire 21A that penetrates each other. As shown in Fig. 11, the connecting horizontal member 20 and the head 2a of the log 2 are joined by a wire 21B that penetrates each other. The reinforcement structure 1E for a slope structure according to the fifth variant connects the head 2a of the log 2 with the head 3a of the steel sheet pile 3, and by applying a reaction force to the steel sheet pile 3, when installing part of the log 2 or the entire log 2 below the groundwater level, it is possible to suppress the log 2 from floating up due to buoyancy, thereby preventing the log 2 from moving from its installation position or being washed away.

[0062] (Second embodiment) As shown in Fig. 12, the reinforcement structure 1F for a slope structure according to the second embodiment is a structure in which steel sheet piles 3 (wall bodies) are provided at the slope toes 10c on both sides in the width direction X of the embankment 10, and multiple logs 2 are provided outside the steel sheet piles 3. In the reinforcement structure 1F of the second embodiment, the depths of the lower ends 2b of all the logs 2 are the same length, and the lower ends 2b of these logs 2 are located deeper than the lower ends 3b of the steel sheet piles 3. The lower ends 3b of the steel sheet piles 3 may be provided at positions deeper than the lower ends 2b of the logs 2. Also, the lower ends 2b of only some of the logs 2 may be deeper than the lower ends 3b of the steel sheet piles 3.

[0063] (Sixth Modification) As shown in Fig. 13, a reinforcement structure 1G for a slope structure according to the sixth modified example is a modified example of the reinforcement structure 1F provided at the slope toe 10c of the second embodiment described above. The reinforcement structure 1G is a structure in which the lower ends 2b of the logs 2 are provided at a position deeper than a passive collapse line K drawn from the lower ends 3b of the steel sheet piles 3 toward the ground G outside the embankment 10 at a passive collapse angle. In other words, the logs 2 are driven to a depth at which they intersect with the passive collapse line K extending from the lower ends 3b of the steel sheet piles 3. Note that, although the lower ends 2b of all the logs 2 are deeper than the passive collapse line K in Fig. 13, only some of the logs 2 may be deeper than the passive collapse line K.

[0064] In the sixth modified example, the lengths of some of all the logs 2 to be placed can be made shorter than in the second embodiment described above, where all the logs 2 are set to the same length. In addition, in the sixth modification, the logs 2 cross the passive collapse line K extending from the steel sheet pile 3, and therefore the shear resistance of the logs 2, which is larger than the ground, is added, thereby increasing the shear resistance of the entire area along the passive collapse line K, and in addition to the effect of increasing the ground strength associated with the increase in density of the surrounding ground due to the installation of the logs 2, the ground strength that efficiently supports the wall can be improved. Depending on the increase in shear strength along the passive collapse line K required for reinforcement, it is not necessary for the lower ends of all the logs 2 to be in tolerance with the passive collapse line K, and economical reinforcement can be achieved by making only the lower end portions of the necessary number of logs 2 deeper than the passive collapse line K.

[0065] The above describes embodiments of the reinforcement structure for a slope structure and the reinforcement method for a slope structure according to the present invention, but the present invention is not limited to the above embodiments and can be modified as appropriate within the scope of the spirit of the present invention.

[0066] For example, in the above-described embodiment, steel sheet piles 3 are used as the wall body, but this is not limited to steel sheet piles, and other wall bodies such as steel pipe sheet piles can also be applied.

[0067] Furthermore, as a reinforcing structure, the depths of the lower ends 2b of all the logs 2 may be the same length, and the lower ends 2b of these logs 2 may be positioned at approximately the same depth as the lower ends 3b of the steel sheet piles 3. By positioning the lower ends of the logs 2 at approximately the same depth as the lower ends 3b of the steel sheet piles 3 in this way, the strength of the ground around the steel sheet piles can be increased over the entire length of the steel sheet piles.

[0068] In addition, the components in the above-described embodiments can be replaced with well-known components as appropriate, without departing from the spirit of the present invention. [Explanation of symbols]

[0069] 1. 1B~1H Reinforcement structure of slope structure 2 logs 2a head 2b Bottom edge 3 Steel sheet pile (wall) 3a head 3b Bottom edge 10 Embankment (slope structure) G, Ga ground K Passive collapse line

Claims

1. A reinforcing structure for a slope structure that reinforces a slope structure having a slope, A wall provided at the shoulder or tail of the glue; A plurality of logs are provided on the ground outside the wall body in an inward / outward direction from the inside to the outside of the slope structure in a side view; A reinforcement structure for a slope structure, comprising:

2. 2. The reinforcement structure for a slope structure according to claim 1, wherein the lower end of at least one of the plurality of logs is deeper than the lower end of the wall body.

3. The wall is formed of steel, 2. The reinforcement structure for a slope structure according to claim 1, wherein the amount of carbon dioxide stored in all of the plurality of logs is greater than the amount of carbon dioxide emitted during the manufacturing of the wall body.

4. 2. A reinforcement structure for a slope structure as described in claim 1, wherein the lower end of the log is located deeper than a passive collapse line drawn from the lower end of the wall body toward the outside of the slope at a passive collapse angle.

5. 2. The reinforcement structure for a slope structure according to claim 1, wherein the logs are inclined so as to extend downward from the head of the wall body toward the outside of the wall body.

6. 2. The reinforcement structure for a slope structure according to claim 1, wherein at least one of the wall body and the logs is driven to a position deeper than the liquefaction layer.

7. The reinforcement structure for a slope structure according to claim 1, wherein the head of the log and the head of the wall are connected.

8. The slope structure has the slope on both sides in the width direction, 2. The reinforcement structure for a slope structure according to claim 1, wherein the log is provided on one of the slopes on both sides in the width direction.

9. A reinforcement method for constructing the reinforcement structure for a slope structure according to any one of claims 1 to 8, comprising: A step of providing the wall body at the glue shoulder or the glue tail; a step of placing a plurality of logs on the ground outside the wall body at the slope; A method for reinforcing a slope structure, comprising:

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