JP2011256604A - Design method of embankment reinforcement structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a design method of an embankment reinforcement structure capable of effectively reinforcing an embankment so as not to be damaged to the extent of the loss of the function of the embankment when the liquefaction of the weak ground occurs in an earthquake.SOLUTION: The design method is provided for designing the reinforcement structure 10 of embankment M which is constructed on weak ground G having possibilities of liquefaction or settlement and includes at least slope surfaces M2 facing each other and nearly-flat top end surface M1. The reinforcement structure 10 of the embankment M includes: a retaining member 1 disposed on the slope surface M2; a resisting member 3 disposed in the ground Ga; and a tension member 2 connecting the retaining member 1 and the resisting member 3. In the design method, the resisting member 3 is disposed in the weak ground Ga underneath the embankment M where the upper load caused by the embankment M could be expected.

Description

  The present invention relates to a method for designing a reinforcement structure for an existing or new embankment built on soft ground that may be liquefied or subsided.

  When the embankment to be used as roads, railways, breakwaters, revetments and other dams is created, if the lower ground is soft, it will be reinforced to the extent that it is strong enough to support the embankment. For example, when the lower ground has a soft viscous soil layer, appropriate ground improvement work such as shallow layer mixing treatment or deep layer mixing treatment should be applied to prevent excessive subsidence or uneven subsidence. It is carried out with a viscous soil layer as a target. On the other hand, if there is a sandy layer in the lower ground (particularly the upper layer) and the groundwater is relatively high, the sandy layer will be liquefied during an earthquake to prevent the embankment slope from protruding. In addition, ground improvement works such as groundwater level lowering method and excess pore water pressure dissipation method will be implemented.

  By the way, if the embankment failure mode is classified, it can be roughly classified into four types as shown in FIGS. The type I shown in FIG. 8a is a slope collapse type, and the surface layer portion of the slope collapses like a landslide due to the inertial force acting on the embankment itself during an earthquake.

  On the other hand, type II shown in FIG. 8b is a case where an arc slip failure occurs inside the embankment due to an inertial force or the like at the time of an earthquake, or an arc slip failure is formed by involving not only the embankment but also the lower ground. Further, type III shown in FIG. 8c is a breaking mode in which the embankment itself divides, and type IV shown in FIG. 8d is a form in which the embankment itself sinks. In this type IV, the function of the dam cannot be secured in the case of excessive subsidence.

  Here, among the failure modes of the embankment described above, the flatness and continuity of the top surface of the embankment are lost particularly in the case of type II and III, and in the case of a linear embankment such as a road or a railway. Its function is completely lost. Therefore, development of embankment reinforcement technology for effectively preventing breakage of the embankment and maintaining the function of the embankment is also desired for these failure modes.

  In addition, there is no possibility of liquefaction or subsidence due to measures to improve the ground by performing chemical injection treatment, cement mixing treatment, etc. on the soft ground directly under the embankment, and relatively hard under the soft ground in the foundation ground ( Conventionally, measures such as placing steel sheet piles etc. to the ground (low), closing the foundation directly on the embankment, and tying the sheet pile heads with tie rods are the conventional methods. However, while these measures can be expected to have a high effect on subsidence suppression, etc., the tie rods tie up the construction cost, and in the case of reinforcement of the existing embankment, prevention of deformation of the embankment and securing of a construction area for adjacent construction There is also a major demerit that tie rod construction is extremely difficult. This disadvantage is particularly noticeable in a linear embankment used for roads, railways, etc., whose extension extends over a long span.

  Considering both the construction cost and the necessity of seismic reinforcement, although some embankment of the embankment is allowed, the above described slope is prevented from protruding and the minimum function of the embankment is ensured, for example, its top end surface An embankment reinforcement method and structure that can ensure flatness of the embankment are desirable.

  The inventors of the present invention have come up with a technique related to such embankment reinforcement method and reinforcement structure, and disclose this in Patent Document 1. More specifically, as disclosed in FIG. 1 of Patent Document 1, a restraining member 1, 1 ′ for suppressing the protrusion is provided on the slope of the facing slope of the embankment B. Resistors 3 and 3 'are arranged in the soft sandy ground G1 outside the buttocks, and the restraining members 1 and 1' and the resistors 3 and 3 'are connected by the tension members 2 and 2', respectively. Reinforced structure.

  The positions of the resistors 3, 3 'are such that when the sandy ground G1 is liquefied, the horizontal displacement of each of the resistors 3, 3' increases, preferably in the region where it becomes the largest. When the embankment B sinks due to liquefaction, a force that tries to protrude from the restraining members 1 and 1 ′ on the slope acts, while the liquefaction causes horizontal displacement in the ground, and resistance in the ground The bodies 3 and 3 'follow the horizontal displacement of the ground and move sideways together with the outer soil so that the tension members 2 and 2' act on the tension, effectively preventing the embankment from protruding. is there.

  As described above, the technique disclosed in Patent Document 1 shows that the direction in which the slope of the embankment protrudes and the displacement direction of the resistor connected to the restraining member that suppresses this are opposite directions. It is used to deter the embankment of the embankment by offsetting both forces.

  While affirming the effect exerted by the disclosed technology, the present inventors have come up with a technology that can further suppress the protrusion of embankment against liquefaction by further research and development.

JP 2009-79415 A

  The present invention has been made in view of the above-mentioned problems, and in particular, for liquefaction of the lower soft ground at the time of an earthquake, it is possible to effectively reinforce the damage to the embankment to the extent that it does not stop functioning. It aims at providing the method of designing the embankment reinforcement structure which can be performed.

  In order to achieve the above-mentioned object, the embankment reinforcing structure design method according to the present invention is a method for embankment having at least a facing slope and a substantially flat top end face, which is constructed on a soft ground that may be liquefied or subsided. A method for designing a reinforcing structure, wherein the embankment reinforcing structure includes a restraining member disposed on a slope, a resistor when disposed in the ground, and a tension member connecting the restraining member and the resistor. The resistor is disposed in a soft ground directly under the embankment, in which the upper load due to the embankment can be expected.

  The embankment reinforcement structure formed by the design method of the present invention has a placement position of the resistor disposed in the soft ground constituting the reinforcement structure with respect to the embankment reinforcement structure disclosed in Patent Document 1, immediately below the embankment. By using soft ground that can anticipate the overload due to the embankment, the reaction force expected for the resistor can be further increased, and as a result, it is expected that the embankment will be further prevented from protruding. It is a reinforcement structure that can be done.

  The embankment reinforcement structure disclosed in Patent Document 1 is a method in which a resistor is disposed in a region where lateral displacement is expected in the case of non-reinforcement in soft ground where liquefaction is a concern. The reaction force required to suppress the surface is expected, and the effect of supporting the resistor by the fluid force that causes the ground (like a viscous fluid) whose rigidity has been lowered by liquefaction to move sideways is utilized. Yes. This "bearing effect" means the latter of the friction effect and the bearing effect known as the resistance force in the resistance body (improved body) of the ground anchor, but the flow direction of the ground with reduced rigidity The greater the projected area of the resistor in the direction perpendicular to the direction, the greater the reaction force by the resistor.

  By the way, according to the present inventors, when assuming a relatively uniform embankment on soft ground where liquefaction is a concern, there is no influence of the overlay load due to the embankment weight than the soft ground directly under the embankment due to an earthquake. The knowledge that the soft ground in the outer area directly under the embankment is liquefied in advance (increase in excess pore water pressure) has been obtained.

  This will be described with reference to FIG. In the figure, a sandy soft ground having a high groundwater level spreads below the embankment M, and this soft ground is composed of a soft ground G1 immediately below the embankment M and a soft ground G2 in the outer area. . When the soft ground is liquefied during an earthquake, the soft ground G2 that is not affected by the loading load is liquefied in advance, thereby causing a lateral displacement X1, where the lateral displacement X1 causes the embankment M. Stretching X2 (horizontal widening accompanying the shear deformation of the embankment) may occur.

  On the other hand, since the soft ground G1 directly under the embankment has not reached liquefaction at the time when the surrounding soft ground G2 is liquefied, the state of high rigidity is maintained. Therefore, if the resistor is disposed in the soft ground G2, stretching occurs in the embankment due to liquefaction of the soft ground G2, and tension is generated in the tensile member by this stretching. When the resistor is arranged in the soft ground G1, since the ground in this area has not yet reached liquefaction, it is possible to effectively suppress the increase in stretching of the embankment by the resistance force of this resistor. It becomes possible.

  The reaction force of the resistor due to the fluid force in the soft ground that has reached liquefaction (the technology disclosed in Patent Document 1), and the resistance of the resistor in the soft ground that has secured rigidity by not having reached liquefaction When the reaction force (technique of the present invention) is compared, it is clear that the magnitude of the reaction force expected per resistor is larger in the latter. This means that the reinforcing effect is increased. That is, only the resistance support effect is expected in liquefied soft ground, while in ground that has not reached liquefaction, a larger support is provided as in the case of the improved ground anchor method. This is because a pressure effect and a friction effect on the peripheral surface of the resistor can also be expected.

  Here, it is desirable to design the position of the resistor disposed in the soft ground immediately below the embankment so that the resistor is disposed in the soft ground directly below the top end surface.

  This is due to the difference between the upper load acting on the soft ground below the top end surface and the slope, and by disposing the resistor directly below the top end surface where the upper load becomes relatively large, A larger bearing effect and a frictional effect on the peripheral surface of the resistor can be expected.

  Further, in another embodiment of the design method of the present invention, regarding the safety factor against liquefaction in the soft ground, the area immediately below the embankment has a higher safety factor than the outer area directly below the embankment, and In the area, the upper area may have a higher safety factor than the lower area, and at least the safety factor against liquefaction may be a determining factor for determining the placement position of the resistor.

  Perform a liquefaction analysis in advance to create a liquefaction safety factor contour etc. in soft ground, and based on this safety factor contour, design methods such as placing resistors in the area with the highest safety factor In addition, there is a design method in which a resistor is arranged in an area with a safety factor as high as possible, taking into consideration the workability and the like. Here, as an embodiment of the analysis, the embankment and the soft ground below it are modeled in a computer (for example, a mesh model for two-dimensional and three-dimensional FEM analysis), and a predetermined input earthquake motion or A method of obtaining an excess pore water pressure distribution in the ground when the horizontal seismic intensity is loaded, and creating a safety factor distribution (contour) against liquefaction based on this excess pore water pressure distribution can be mentioned.

  By the way, the embankment reinforcement structure formed by the above-described design method of the present invention is effective even when an earthquake larger than the earthquake motion assumed at the time of design occurs and the foundation ground directly under the embankment is completely liquefied. Is described below.

  Regardless of the magnitude of the earthquake motion, whenever the foundation ground liquefies, liquefaction always occurs in the order from the ground directly under the embankment to the ground directly under the embankment without the influence of the overload due to the embankment. For this reason, in the event of a large earthquake motion that exceeds the expected level, anchor tension will be expected because the foundation base immediately below the embankment has not yet reached liquefaction when the outer periphery directly below the embankment where stretch stretching occurs. Can do.

  Therefore, in an ordinary design, an assumed earthquake scale is set for the target structure, and it will not be possible to sufficiently guarantee the safety of the structure against an earthquake exceeding this scale, but it is formed by the design method of the present invention. The embankment reinforcement structure that can be used can expect the reinforcement effect against the earthquake motion exceeding the assumed earthquake motion.

  Furthermore, each resistor of the reinforcing structure on the opposite slope may be designed to be disposed at a position on the other slope side with respect to the center line of the embankment, or on the other side of the center line of the embankment You may design so that it may arrange | position to the position which does not become the slope side of this, ie, its own slope side rather than a center line.

  This is different from the technique disclosed in Patent Document 1 in that the reinforcing structure formed by the design method of the present invention is a ground having high rigidity by disposing a resistor in a soft ground that can allow for an overload due to embankment. Based on the design philosophy (technical philosophy) of expecting a high reaction force that can suppress the protrusion of the slope, it is due to the movement of the resistor along the lateral flow of the base plate on the other side Since it is not a design philosophy that expects a reaction force, it is not necessary to dispose both tensile members and the resistors at the tip thereof in the ground so as to intersect each other.

  Here, although the restraining member applied in the embankment reinforcement structure formed by the design method of the present invention is not particularly limited, an appropriate member having a strength capable of restraining the embankment without destroying itself. What is necessary is just to be comprised from a material. For example, a steel pile, a concrete block, a sheet material containing steel fiber, carbon fiber, etc., a sandbag, a parent pile horizontal sheet pile composed of H steel installed at a predetermined interval and a wooden board arranged between the H steel, etc. The restraining member can be formed from the material (member). In addition, the slope location where the restraint member is installed is the restraint member, such as the form of only the slope, the form of the slope only, the form of the entire slope, the form of the range from the slope to the middle of the slope. Thus, it is possible to select an appropriate portion where the protrusion of the slope can be suppressed.

  Further, as the tension member, an appropriate material having a tensile strength that can withstand the tension that can be generated when the slope is about to protrude, such as a tie rod, a PC steel bar, a PC steel wire, and a high-tensile steel bar can be selected.

  The embankment reinforcement structure formed by the design method of the present invention can be applied as a reinforcement structure for newly established embankments and has a great advantage in that existing embankments can be reinforced economically. It is not a method of improving the ground directly under the embankment, but it is mainly the installation of restraining members on the slope and the placement of resistors in the soft ground, leaving the existing embankment, This is because the reinforcement work can be performed while using this.

  Moreover, when this embankment is a linear embankment such as a road or a railroad, tensile members are arranged at predetermined intervals along the line. If necessary, the tension member can be installed in two or three stages from the slope of the slope to the top.

  Further, the material and the shape of the resistor connected to the tension member are not particularly limited. For example, a resistance plate attached to the tip of the tension member, a columnar block of concrete, etc. It is only necessary to have a shape and strength (tensile strength, friction strength, etc.) that have a large cross section and resist the tensile force transmitted from the tensile member to stay in the ground.

  Furthermore, an embodiment in which the tension member and the resistor are formed of a ground anchor having a fixing body at the tip may be used. The ground anchor is generally constituted by an anchor body formed by a grout, a tension portion, and an anchor head in order to transmit a tensile force to the ground. Here, the anchor head is a portion that transmits the force received when the embankment slope is about to protrude to the tension portion, and can be constituted by a fixing bracket, a bearing plate, a pedestal block, or the like. In addition, the tension part is a part that transmits the tensile force from the anchor head to the anchor body installed in the soft ground, which can be composed of a tendon and a sheath, etc., which is insulated from the ground and slope. It has a flexible structure. Further, the anchor body is a resistance portion against pulling that is formed or installed in the ground in order to transmit the tensile force of tendon to the ground. The anchor body can be formed by injecting cement grout (cement paste or mortar), synthetic resin grout, or the like.

  According to the design method of the embankment reinforcement structure of the present invention, the arrangement position of the resistor is changed to the soft ground directly under the embankment with respect to the reinforcement structure disclosed in Patent Document 1, and in particular, the liquefaction safety factor in the design Because the reinforcement structure is designed as a determinant of the resistor placement position, a greater reaction force can be exerted by the resistor during an earthquake, and the flooding can be more effectively suppressed. An embankment reinforcement structure can be formed.

  As can be understood from the above description, according to the embankment reinforcing structure design method of the present invention, the damage to the embankment is not brought to a stop due to liquefaction of the soft ground below the embankment particularly during an earthquake. It is possible to design a reinforcing structure that can be effectively reinforced.

It is the flowchart explaining the design method of the embankment reinforcement structure of this invention. It is a schematic diagram which shows one Embodiment of the embankment reinforcement structure formed by the design method of this invention. It is a schematic diagram which shows other embodiment of the embankment reinforcement structure formed by the design method of this invention. It is an excess pore water pressure ratio distribution map by centrifugal loading model experiment. It is an excess pore water pressure ratio distribution map by liquefaction analysis. It is the figure which showed the liquefaction safety factor contour in the ground by liquefaction analysis, (a) is the result of the analysis model of embankment height 8m, embankment top width 25, soft ground layer thickness 20m, (b) It is the result of the analysis model of embankment height 6m, embankment top end width 10.8, soft ground layer thickness 20m. It is the figure explaining the state where the soft ground of the outer area just under embankment has liquefied ahead. (A)-(d) is the schematic diagram which showed the destruction form of the embankment.

  Embodiments of the present invention will be described below with reference to the drawings. The illustrated example shows a design method for the reinforcement structure of an existing embankment on soft ground where liquefaction is highly likely, and a reinforcement structure designed by this design method. Of course, the design method of the present invention can be appropriately modified and applied to a reinforcing structure for measures against consolidation subsidence, for soft ground with the possibility of consolidation subsidence.

  FIG. 1 is a flowchart illustrating a method for designing a bank reinforcement structure according to the present invention. In this design method, first, the groundwater level is relatively high (for example, the groundwater level shallower than 10 m below the ground surface) in the new bank or the ground spreading under the existing bank, and the sandy system is within the surface layer of about 20 m. In the case where there is an existing ground, this target ground is recognized as a soft ground that may be liquefied, and a liquefaction safety factor distribution (liquefaction safety factor contour) in the soft ground is created by liquefaction analysis (step S1). ). 6A and 6B show an example of a liquefaction safety factor contour.

  In the design method shown in the figure, as a general rule, the soft ground directly under the embankment is not improved, but a reinforcement structure is applied to the embankment. The purpose of the design is to secure the minimum functions such as flatness of the top edge of the embankment by suppressing the collapse.

  When the liquefaction safety factor contour is created in step S1, the specification of the reinforcement structure is determined, and the arrangement position of the resistor forming the reinforcement structure is determined in the ground area directly under the embankment (step S2).

Specifically, a reinforcing structure designed by this design method will be described with reference to FIG.
The reinforcing structure 10 is a structure that reinforces an existing bank M that is designed on the soft ground G that may be liquefied and that is designed based on the design flow of FIG. Specifically, the restraining members 1 and 1 are provided to suppress the protrusion of the embossing of the embankment M in which the outer shape is formed from the substantially flat top end face M1 and the opposing slopes M2 and M2. Resistors 3 and 3 installed in the soft ground G just below the embankment M are connected by the tension members 2 and 2, respectively, and the reinforcement structure 10 is formed for each slope M1. In addition, the embankment M reinforced with this reinforcement structure 10 is provided as infrastructure facilities, such as a railroad and a road, whose extension is a linear embankment that extends over a long span in general. In addition to the fact that the top end face M1 is flat, the top end face M1 is “substantially flat”, and the form of a normal road structure in which the center of the top end face M1 is slightly higher and the sides are slightly lower. It is a meaning including.

  Here, the restraining member 1 can use any one of a steel plate, a concrete block, a sheet material containing steel fiber or carbon fiber, a sandbag, or a combination of these, and at least a slope is used. It is strong enough to resist the protruding force that acts when it tries to protrude during an earthquake.

  Moreover, the tension member 2 can use any one of a tie rod, a PC steel bar, a PC steel wire, a high-tensile steel bar, and the like, and is transmitted via the restraining member 1 when the slope is about to protrude. It has a tensile strength that can withstand tension.

  Further, the resistor 3 has a cross section larger than at least the tension member such as a bearing plate and a concrete columnar block, and has a shape and strength that resists the tensile force transmitted from the tension member to stay in the ground. It has.

  In addition, as a unit of the tension member 2 and the resistor 3, a ground anchor including a tension member composed of a tendon and a sheath and a resistor composed of a cement grout can be applied.

  In the present design method, the position of the resistor 3 is arranged in any area in the soft ground in the soft ground G, which is directly under the bank M, and where the loading load due to the bank M can be expected. is there.

  More specifically, in the embankment M shown in the figure, the area Ga immediately below the center top end face M1 and the area Gb directly below the side slope M2 are areas in which the loading due to the embankment M can be expected. Therefore, the resistor 3 is disposed in any part of this area.

  Since the resistor 3 is disposed in the ground area that receives a larger overload, a larger reaction force can be obtained from the resistor 3 when the slope M2 is about to protrude during liquefaction. The arrangement position of the resistor 3 is preferably the area Ga immediately below the top end face M1 among the areas Ga and Gb as shown in the drawing.

  As will be described later with reference to FIG. 6, from the results of liquefaction analysis, the safety factor is generally the smallest in the outer area Gc directly under the embankment where the overload cannot be expected, and in the order of areas Gb and Ga. From the fact that the safety factor increases, it can be seen that the resistor is preferably arranged in the area Ga having the highest safety factor.

  In the event of an earthquake, the outer area Gc directly under the embankment, which is not affected by the loading load due to the embankment weight, is liquefied ahead of the ground areas Ga and Gb directly under the embankment. At this time, the rigidity of the outer area Gc immediately below the embankment is lowered, and stretching (horizontal widening accompanying shear deformation of the embankment) occurs in the embankment M. At the stage where the outer area Gc is liquefied, the ground areas Ga and Gb immediately below the embankment have not reached liquefaction, and therefore high ground rigidity is maintained.

  Since the resistors are arranged in the ground areas Ga and Gb immediately below the embankment where the high rigidity is maintained, the initial stage of the liquefaction of the soft ground G, that is, the outer area Gc is liquefied. In the stage, it is possible to effectively suppress an increase in the stretching of the embankment caused by the liquefaction of the outer area Gc.

  And, by suppressing the stretching of the embankment at the initial stage of liquefaction, the design method of the present invention is intended to suppress the embankment collapse due to the protrusion of the slope, while allowing some settlement of the embankment. Will be achieved.

  FIG. 3 shows another embodiment of the reinforcing structure. In this reinforcing structure 10A, the tensile members 2 'and 2' extending from the restraining members 1 of the opposing slopes M2 and M2 cross each other, and the resistors 3 and 3 are disposed in the area Ga immediately below the top end face M1. It has been done.

  In addition to the example shown in the figure, the resistor is disposed in the area Gb immediately below the corresponding slope M2 (the tensile member does not cross) or in the area Gb directly below the counterpart slope M2. It may be provided (one in which the tensile member crosses).

  FIG. 4 shows the result of one embodiment of the ground liquefaction analysis in step S1 in the design method of the present invention. The inventors obtained the excess pore water pressure ratio distribution by a centrifugal loading model experiment. It is a contour chart. FIG. 5 is a graph showing the excess pore water pressure ratio distribution obtained by the present inventors by liquefaction analysis.

  In both distribution maps, the excess pore water pressure ratio is relatively high in the area outside the area immediately below the embankment, and the excess pore water pressure directly below the top of the embankment is below the slope. The ratio is getting smaller. Furthermore, in the area directly under the embankment, the excess pore water pressure ratio in the upper area is smaller than that in the lower area. The excess pore water pressure ratio is a value of the ratio between the excess pore water pressure and the initial vertical effective stress, and the state where this value reaches 1.0 corresponds to a liquefaction, that is, a safety factor of 1.0. Therefore, the contour regarding the excess pore water pressure ratio shown in FIG. 4 becomes the liquefaction safety factor as it is.

  FIGS. 6a and 6b show liquefaction safety factor contours by liquefaction analysis modeling the embankment structure of highways and railways by the present inventors. More specifically, FIG. 6a shows embankment. FIG. 6B shows the result of an analysis model with a height of 8 m, a bank top edge width of 25, and a soft ground layer thickness of 20 m, and FIG. 6B shows the result of an analysis model with a bank height of 6 m, a bank top edge width of 10.8, and a soft ground layer thickness of 20 m.

  The liquefaction safety factor distributions (contours) shown in FIGS. 6a and 6b are created in step S1, and the optimum value with these factors taken into consideration, that is, as much as possible, taking this safety factor, workability, construction cost, etc. Position in the ground just below the embankment where the liquefaction safety rate is high and where the construction cost is as low as possible (whether directly below the top or slope, either in the upper ground or in the lower ground) Is determined as the arrangement position of the resistor, and the specific design of the reinforcing structure is determined. In the case where the rapid recovery is more important than the construction cost, the placement position of the resistor immediately below the embankment is determined using the safety factor and workability as two main factors for determining the resistor placement position.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Suppression member, 2, 2 '... Tensile member, 3 ... Resistor 10, 10A ... Reinforcement structure, M ... Embankment, M1 ... Top end surface, M2 ... Slope, G ... Soft ground (possibility of liquefaction Some ground), Ga ... Area just below the top of the embankment, Gb ... Area just below the slope, Gc ... Outside area just below the embankment

Claims (5)

A method for designing a reinforcement structure for embankments that is created on soft ground that may be liquefied or subsidence, and that has at least a facing slope and a substantially flat top face,
The reinforcing structure of the embankment is composed of a restraining member disposed on the slope, a resistor when disposed in the ground, and a tension member connecting the restraining member and the resistor,
A method for designing an embankment reinforcement structure in which the resistor is disposed in a soft ground that is directly under the embankment and that allows for an expected load due to the embankment.   The design method of the embankment reinforcement structure of Claim 1 which arrange | positions the said resistor in the soft ground just under the said top end surface.   Regarding the safety factor against liquefaction in the soft ground, the ground area immediately below the embankment has a higher safety factor than the outer ground area directly below the embankment, and in the ground area directly below the embankment, the upper ground area is the lower ground 3. The embankment reinforcing structure design method according to claim 1 or 2, which has a safety factor higher than that of an area, and uses at least the safety factor against liquefaction as a determinant for determining the arrangement position of the resistor.   The design method of the embankment reinforcement structure in any one of Claims 1-3 which arrange | positions each resistor of the reinforcement structure of the opposing slope to the position which becomes the other slope side rather than the center line of embankment.   The design method of the embankment reinforcement structure in any one of Claims 1-3 which arrange | positions each resistor of the reinforcement structure of the opposing slope to the position which does not become the other slope side rather than the center line of embankment.

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