Retaining wall reinforcing method

Abstract

To realize a retaining wall reinforcing method which can prevent a retaining wall from collapsing using a simple construction method at low cost even if repeated vibrations occur due to an earthquake or the like.SOLUTION: A retaining wall portion 50 has a drainage pipe 7 made of a rigid body with a plurality of holes 9 formed in a longitudinal direction and one open end, and is provided with a drainage hole 3. The drainage pipe 7 is driven to the retaining wall portion 50 into the ground 6 through the drainage hole 3 so that the open end protrudes from the retaining wall portion 50. Then, there is provided a support member 8 in which a pair of curved members 12a, 12b are arranged opposite to each other to form a cylindrical portion 13, the drainage pipe 7 is inserted into the cylindrical portion 13, the pair of curved members 12a, 12b are fastened to each other with a hexagonal socket head cap screw 15, and at least one of the curved members 12a of the support member 8 is abutted against the retaining wall portion 50 to prevent the retaining wall portion 50 from collapsing.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for reinforcing a retaining wall, and more particularly to a method for reinforcing a retaining wall provided for stabilizing an artificial or natural slope. [Background technology]

[0002] In order to stabilize artificial slopes such as embankments and cuts, as well as natural slopes, retaining walls are installed on the surface of the slope. When groundwater rises due to an earthquake or torrential rain, it is necessary to drain the water from the ground. Therefore, a technique is known in which drainage holes are installed in the retaining wall and the groundwater is drained from the drainage holes.

[0003] For example, Patent Document 1 proposes a method of reinforcing a retaining wall in which a tubular member is inserted and driven into the ground through a drainage hole.

[0004] In Patent Document 1, the tubular member has many holes in the longitudinal direction, one end is open, and the other end is closed. The tubular member is inserted into the ground through the drainage holes and cast into the ground, compacting the ground and fixing the tubular member so that groundwater can be drained from the open end of the tubular member, thereby ensuring the stability of the ground behind the retaining wall.

[0005] There is also known a technique for strengthening the ground by fixing anchor members into the ground, thereby stabilizing the slope and preventing landslide-like movement of the slope behind the retaining wall.

[0006] For example, Non-Patent Document 1 describes a method in which an anchor member connected to a wire member is driven into the ground using a driving rod, and then the driving rod is removed and the wire member is pulled upward, pivoting the anchor to set it in a predetermined direction, which is thought to be a simple and inexpensive method of strengthening the ground and contributing to stabilizing the slope.

[0007] Patent Document 2 proposes a method of reinforcing a slope, which includes a reinforcing pipe body with a female thread portion formed near its open end, a support plate with a central hole through which the reinforcing pipe body can be inserted and an engagement portion erected at the edge of the central hole, a tapered member having a substantially cylindrical shape with a tapered outer periphery and an inner diameter on the small diameter side formed so as to fit with the outer diameter of the reinforcing pipe body, and a cylindrical fastening member having a male thread portion, the reinforcing pipe body is driven into a slope so that the open end is exposed to the surface, the reinforcing pipe body is inserted into the central hole so that the entire flat part of the support plate is in contact with the surface of the slope, the tapered member is fitted onto the reinforcing pipe body from the small diameter side, the fastening member is fastened to the reinforcing pipe body, the tapered member is wedged into the engagement portion of the support plate to press the support plate against the surface of the slope, and the slope is restrained by the support plate.

[0008] In Patent Document 2, a reinforcing pipe with a pressure plate is constructed using the above-mentioned reinforcing pipe body, support plate, tapered member and fastening member, and by bringing the pressure plate into surface contact with the slope, it is attempted to reinforce the entire slope without compromising the stability of the ground. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 4727718 Specification (Claim 1, Figure 1, etc.) [Patent Document 2] JP 2008-231750 A (Claim 5, Figures 1, 2, etc.) [Non-patent literature]

[0010] [Non-Patent Document 1] "Pivot anchor 'Duckbill Earth Anchor'" from the Construction Price Research Institute, a construction material and construction method information comparison site for people involved in selecting construction materials and construction methods, [online], January 1, 2023, Nippon Lantec Co., Ltd., [Retrieved June 25, 2023], Internet<URL:https: / / www.k-mil.net / contents / detail / 153> Summary of the Invention [Problem to be solved by the invention]

[0011] However, in the above Patent Document 1 and Non-Patent Document 1, repeated strong vibrations such as earthquakes may cause the retaining wall to separate from the ground behind the wall, causing the wall to collapse toward the ground.

[0012] Figure 12 is a schematic diagram showing the process in which a retaining wall separates from the ground and collapses due to an earthquake.

[0013] Figure 12(a) shows the state of the retaining wall before the earthquake, Figure 12(b) shows the behavior of the retaining wall when vibrations were first generated by the earthquake, and Figure 12(c) shows the behavior of the retaining wall when repeated vibrations were generated by the earthquake.

[0014] Under normal circumstances, the retaining wall 102 stands on the ground 105 so as to follow the ground 101, as shown in Fig. 12(a). When vibrations occur due to an earthquake or the like, the soil particles that form the ground 101 have an adhesive force, so that the ground 101 and the retaining wall 102 behave differently, and the retaining wall 102 separates from the ground 101 and vibrates independently. As a result, a gap 103 is generated between the ground 101 and the retaining wall 102, as shown in Fig. 12(b), and soil particles 104 in the ground 101 fall into the gap 103 (wedge slide) as shown by arrow a, so that the retaining wall 102 cannot return to its original position even if a backswing vibration occurs. If such vibrations occur repeatedly, as shown by arrows b to d in Figure 12(c), soil particles 104b to 104d will fall into the gaps 103 more noticeably, causing the retaining wall 102 to lean forward. As a result, the retaining wall 102 will eventually be forced to topple onto the ground 105, potentially causing injury to pedestrians and others.

[0015] Furthermore, Patent Document 2 attempts to reinforce the entire slope by bringing a pressure plate into surface contact with the slope. If this is applied to a retaining wall, it is believed that since the pressure plate will be in surface contact with the retaining wall, it will be possible to prevent the retaining wall from collapsing without compromising the stability of the ground.

[0016] However, in Patent Document 2, the pressure plate is composed of a bearing plate, a tapered member, and a fastening member, and therefore many parts with complex shapes are required, and furthermore, since the pressure plate is fastened to the reinforcing pipe body, it is necessary to form a female screw part at the open end of the reinforcing pipe body, which may lead to an increase in production costs. In addition, in Patent Document 2, the reinforcing pipe body is cast into the ground, but depending on the hardness of the ground, it may be difficult to drive the reinforcing pipe body into the ground, and therefore post-processing such as cutting the reinforcing pipe body itself and then welding and joining the tubular part near the open end where the female screw part is formed and the tubular part that penetrates the ground is required, which requires a lot of work for construction and may lead to an increase in construction costs.

[0017] As described above, the pressure plate structure described in Patent Document 2 is likely to result in increased production and construction costs, and various issues remain before it can be put into practical use.

[0018] The present invention has been made in consideration of the above circumstances, and aims to provide a method for reinforcing a retaining wall that can prevent the wall from collapsing with simple ingenuity and at low cost, even if repeated vibrations occur due to an earthquake or the like. [Means for solving the problem]

[0019] In order to achieve the above-mentioned object, the retaining wall reinforcement method of the present invention has a tubular member made of a rigid body with a large number of holes formed in the longitudinal direction and one end open, and is provided with at least one drainage hole, by driving the tubular member into the ground through the drainage hole so that the open end protrudes from the retaining wall, thereby reinforcing the retaining wall, and is characterized in that a retaining wall support member is provided having a pair of curved members arranged opposite each other to form a cylindrical portion, the tubular member is inserted into the cylindrical portion, the pair of curved members are fastened together with fasteners, and at least one of the curved members of the retaining wall support member is abutted against the retaining wall, preventing the retaining wall from collapsing.

[0020] Here, the above-mentioned drainage holes include not only existing drainage holes, but also drainage holes formed by drilling holes in retaining walls.

[0021] In addition, the retaining wall reinforcement method of the present invention is characterized by forming a plurality of concave spiral portions at predetermined intervals on the outer periphery of the tubular member, and connecting a plurality of the tubular members via joint members having convex spiral portions formed on their outer periphery to increase the length.

[0022] Furthermore, the retaining wall reinforcement method of the present invention is characterized in that a gap is formed between the retaining wall support member and the retaining wall, and the gap is filled with a high-strength material.

[0023] In addition, the retaining wall reinforcement method of the present invention is characterized in that the tubular member has a closed end on the opposite side to the open end, and the tubular member is driven into the ground through the drainage hole to compact the ground while allowing groundwater to be drained from the open end of the tubular member.

[0024] Furthermore, the method for reinforcing a retaining wall of the present invention is characterized in that the tubular member has a zinc-aluminum-magnesium based plating film formed on the surface thereof.

[0025] Furthermore, the present invention is applicable not only to retaining walls for drainage works having a drainage function, but also to retaining walls for ground anchor works in which anchor members are buried in the ground.

[0026] In this case, a pivoting system that uses a wire member to fix the anchor member into the ground makes it relatively easy to secure a work area, is low cost, and is easy to install.

[0027] In other words, the retaining wall reinforcement method of the present invention has a pivotable anchor member connected to a long wire member, and the anchor member is embedded from the retaining wall into the ground to fix the anchor member in the ground and reinforce the retaining wall, and is characterized in that a tubular member is inserted into a hole provided in the retaining wall so that one end protrudes from the retaining wall, the end of the wire member is fixed with a wedge-shaped member and the wedge-shaped member is engaged with the inner surface of the tubular member, a support member having a pair of curved members arranged opposite each other to form a cylindrical portion is provided, the tubular member is inserted into the cylindrical portion, the pair of curved members are fastened together with a fastener, and at least one of the curved members of the support member is abutted against the retaining wall, preventing the retaining wall from collapsing.

[0028] Furthermore, the method for reinforcing a retaining wall of the present invention is characterized in that a gap is formed between the support member and the retaining wall, and the gap is filled with a high-strength material.

[0029] Furthermore, in the retaining-wall reinforcing method of the present invention, the wire member is preferably made of one material selected from a stainless steel material and a carbon fiber material.

[0030] Furthermore, the present technology for preventing the collapse of retaining walls has the same or corresponding technical features in the two independent claims mentioned above, and are linked to form a single general inventive concept. Effect of the Invention

[0031] According to the above-mentioned method for reinforcing a retaining wall, a support member is provided having a pair of curved members arranged opposite to each other to form a cylindrical portion, a tubular member is inserted into the cylindrical portion, and the pair of curved members are fastened together with fasteners, and at least one of the curved members of the support member is abutted against the retaining wall to prevent the retaining wall from collapsing. Therefore, even if repeated vibrations occur due to an earthquake or the like, the retaining wall is supported by the support members, so that it is possible to prevent a gap from being generated between the retaining wall and the ground behind it, and therefore it is possible to prevent soil particles in the ground from falling onto the back surface of the retaining wall, and it is possible to effectively prevent the retaining wall from collapsing. Moreover, since the retaining wall can be prevented from collapsing simply by inserting and fastening a tubular member into a support member having a pair of curved members arranged opposite to each other, there is no need for a pressure plate of a complex shape as in the past, and the manufacturing cost can be reduced. Furthermore, since there is no need to form a threaded portion near the open end, even if the ground is hard and it becomes difficult to drive the tubular member into the ground, it is sufficient to simply cut the tubular member appropriately, and there is no need to cut the middle part of the tubular member and perform post-processing such as welding, as in the conventional method, so that a construction method with good workability can be realized with simple ingenuity at low cost.

[0032] In addition, by forming a plurality of concave spiral portions at a predetermined interval on the outer periphery of the tubular member and connecting a plurality of the tubular members via a joint member having a convex spiral portion formed on the outer periphery to make the tubular member longer, the present invention can be applied to water collection boring works requiring long tubular members. In other words, by applying the present invention to large-scale embankment construction sites, it is possible to prevent the collapse of retaining walls and effectively prevent landslides caused by earthquakes, heavy rain, etc.

[0033] Furthermore, by forming a gap between the support member and the retaining wall and filling the gap with a high-strength material, the frictional resistance of the tubular member can be prevented from decreasing, and the retaining wall can be more effectively prevented from collapsing.

[0034] In addition, the tubular member has a closed end on the opposite side to the open end, and by driving the tubular member into the ground through the drain hole, the ground is compacted and groundwater can be drained from the open end of the tubular member. Therefore, the tubular member also penetrates into the ground behind the retaining wall, and the ground is compacted by the shear resistance of the tubular member and by being driven into the ground. Even if the groundwater level rises due to excess pore water pressure generated during an earthquake, the groundwater is drained outside the system through the drain hole via the tubular member, thereby improving the stability of the ground behind the retaining wall.

[0035] Furthermore, since the tubular member has a zinc-aluminum-magnesium plating film formed on the surface thereof, the tubular member can be prevented from corroding even if the tubular member is buried in the ground for a long period of time.

[0036] Furthermore, according to the method for reinforcing a retaining wall of the present invention, a tubular member is inserted into a hole provided in the retaining wall so that one end of the tubular member protrudes from the retaining wall, the end of the wire member is fixed with a wedge member, and the wedge member is engaged with the inner peripheral surface of the tubular member, a support member is provided in which a pair of curved members are arranged opposite each other to form a cylindrical portion, the tubular member is inserted into the cylindrical portion, the pair of curved members are fastened together with fasteners, and at least one of the curved members of the support member is abutted against the retaining wall, thereby preventing the retaining wall from collapsing, so that the retaining wall can be effectively prevented from collapsing at low cost, as described above. In other words, a construction method with good workability can be realized with simple ingenuity at low cost for not only drainage works but also ground anchor works.

[0037] In addition, by forming a gap between the support member and the retaining wall and filling the gap with a high-strength material, the periphery of the tubular member is reinforced, and the retaining wall can be more effectively prevented from collapsing. In particular, since holes formed in the retaining wall are usually filled by applying a high-strength material such as mortar after drilling, by simultaneously filling the gap with the high-strength material, the filled portion of the high-strength material can function as a base, allowing efficient construction and ensuring the desired strength.

[0038] Furthermore, by forming the wire member from one selected from a stainless steel material and a carbon fiber material, the wire member can be prevented from rusting, and good durability can be obtained.

[0039] Thus, according to the present invention, in drainage works and ground anchor works having retaining walls, it is possible to effectively prevent the collapse of the retaining walls even if repeated vibrations occur due to earthquakes, etc. [Brief description of the drawings]

[0040] [Figure 1] FIG. 1 is a schematic diagram showing an embodiment (first embodiment) of a reinforcement structure using a retaining wall reinforcement method according to the present invention. [Diagram 2] FIG. 2 is an enlarged view of part A in FIG. [Diagram 3] 3A and 3B are diagrams showing the external appearance of a drainage pipe, in which FIG. 3A is a front view and FIG. 3B is a view taken along the arrow BB in FIG. 3A. [Figure 4] 4A and 4B are diagrams showing the details of the support member, in which FIG. 4A is a front view and FIG. 4B is a view taken along the line CC in FIG. 4A. [Diagram 5] 13 is a diagram for explaining the relationship between the overturning moment and resistance moment of a retaining wall. FIG. [Figure 6] FIG. 11 is a diagram showing a first modified example of the above embodiment. [Figure 7] FIG. 7(a) shows an example of a connecting drainage pipe according to a second modified example of the above embodiment, and FIG. 7(b) is a view taken along the line DD in FIG. 7(a). [Figure 8]FIG. 11 is a front view showing an example of a joint member used in the second modified example. [Figure 9] FIG. 2 is an enlarged view of a main portion of a second embodiment of a reinforcement structure using the retaining wall reinforcement method according to the present invention. [Figure 10] 13 is a schematic diagram showing an anchor member used in the second embodiment. FIG. [Figure 11] 5A and 5B are diagrams showing details of a wedge-shaped member used in the second embodiment, where (a) is a cross-sectional view and (b) is a cross-sectional view taken along the line EE of (a). [Figure 12] FIG. 1 is a diagram for explaining a problem with the conventional technology. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] Next, an embodiment of the present invention will be described in detail with reference to the drawings.

[0042] FIG. 1 is a schematic diagram showing one embodiment (first embodiment) of a reinforcement structure using a retaining wall reinforcement method according to the present invention, and FIG. 2 is an enlarged view of a portion A in FIG.

[0043] Reference numeral 1 denotes a stone retaining wall, which is made up of a number of piled stones 2 assembled in an inclined manner. A number of drainage holes 3 are provided vertically and horizontally at predetermined intervals on the sloping surface of the stone retaining wall 1.

[0044] A backfill concrete section 4 is formed on the back side of the stone retaining wall 1, and a backfill crushed stone section 5 is formed on the back side of the backfill concrete section 4, and ground 6 is arranged on the back side of the backfill crushed stone section 5. In this first embodiment, the stone retaining wall 1, the backfill concrete section 4, and the backfill crushed stone section 5 form a retaining wall section 50.

[0045] 2, a drainage pipe (tubular member) 7 is inserted and cast into each drainage hole 3, and the drainage pipe 7 is inserted into a support member 8. That is, the support member 8 is fitted onto the drainage pipe 7, a part of the support member 8 is in contact with the retaining wall portion 50 (stone retaining wall 1), and the tip of the drainage pipe 7 penetrates into the ground 6.

[0046] FIG. 3 shows the external appearance of the drain pipe 7, where FIG. 3(a) is a front view and FIG. 3(b) is a view seen in the direction of arrow BB in FIG. 3(a).

[0047] The drainage pipe 7 is made of a rigid body mainly made of iron, and has a large number of holes 9 formed in the longitudinal direction. In this first embodiment, the holes 9 are formed in an elongated hole shape and are arranged in a staggered pattern in the circumferential direction. Furthermore, the drainage pipe 7 has one end formed as an open end 10a, and the other end opposite the open end 10a is crushed into a flat plate shape and blocked into a roughly pointed shape to facilitate casting, thereby forming a blocked portion 10b. By casting the drainage pipe 7 into the ground 6 from the drainage hole 3, the ground 6 is compacted and groundwater can be drained from the open end 10a of the drainage pipe 7. The shape of the blocked portion 10b is not particularly limited as long as it has a compaction effect when cast, and it is preferable to form it into a cone shape, for example.

[0048] In this retaining wall reinforcement method, the drainage pipe 7 is formed with the other end opposite the open end 10a closed, and the drainage pipe 7 is driven into the ground 6 through the drainage hole 3 to compact the ground 6 and allow groundwater to drain from the open end 10a of the drainage pipe 7. Therefore, the drainage pipe 7 also penetrates into the ground 6 behind the retaining wall section 50, and the ground 6 is compacted by the shear resistance of the drainage pipe 7 and by being driven into the ground 6. Even if the groundwater level rises due to excess pore water pressure generated during an earthquake, the groundwater is drained outside the system through the drainage hole 3 via the drainage pipe 7, thereby improving the stability of the ground 6 behind the retaining wall section 50.

[0049] FIG. 4 shows details of the support member 8, where FIG. 4(a) is a front view and FIG. 4(b) is a view seen in the direction of arrow CC in FIG. 4(a).

[0050] That is, the support member 8 has a pair of curved members 12a, 12b with female threads 11a, 11b engraved on both ends. The pair of curved members 12a, 12b are arranged facing each other in the support member 8 so as to form a cylindrical portion 13. A hexagonal socket bolt (fastener) 15 having a male thread 14 is screwed into the female threads 11a, 11b, and the drain pipe 7 is inserted into the cylindrical portion 13 and fastened by the support member 8.

[0051] In this manner, in the first embodiment, since the retaining wall portion 50 is supported by the support member 8, the retaining wall portion 50 can be effectively prevented from tilting forward and toppling over even if repeated vibrations occur due to an earthquake or the like.

[0052] In other words, in order to prevent the retaining wall section 50 from collapsing, it is necessary to set the resistance moment, whose parameter is the frictional resistance force of the drainage pipe 7, to be greater than the overturning moment, whose parameter is the magnitude of shaking during an earthquake.

[0053] Fig. 5 is a diagram for explaining the relationship between the overturning moment and the resistance moment, and for convenience of explanation, Fig. 5 shows a case where two rows of drainage pipes 7a, 7b are arranged vertically and horizontally on the surface of the retaining wall section 50, but the same applies to a case where three or more rows of drainage pipes 7 are arranged vertically and horizontally on the surface of the retaining wall section 50 as in Fig. 1. In the figure, 51 indicates the ground, F is the fulcrum of the rotational moment, and G is the position of the center of gravity of the retaining wall section 50.

[0054] The horizontal distance between the fulcrum F and the center of gravity G is L1 (m), the vertical distance between the fulcrum F and the center of gravity G is L3 (m), and the horizontal acceleration during the earthquake is ah (m / sec 2 ), and the vertical acceleration during the earthquake is av(m / sec 2 ), the overturning moment M can be expressed by equation (1).

[0055] M = L1 × av + L3 × ah … (1) On the other hand, if the vertical distance between fulcrum F and drain pipe 7a is L2 (m), the vertical distance between fulcrum F and drain pipe 7b is L4 (m), the frictional resistance force of drain pipe 7a is τ1 (N), and the frictional resistance force of drain pipe 7b is τ2 (N), the resistance moment R can be expressed by equation (2).

[0056] R = L2 × τ1 + L4 × τ2 … (2) Therefore, by setting parameters such as the pouring positions of the drainage pipes 7a, 7b and the frictional resistance forces τ1, τ2 so that R>M, it is possible to prevent the retaining wall portion 50 from collapsing.

[0057] However, normally, the gap between the outer periphery of the drainage pipes 7a, 7b and the drainage hole 3 is filled with mortar or the like to form a filler section (not shown). However, when repeated vibrations occur due to an earthquake, the frictional resistance between the outer periphery of the drainage pipes 7a, 7b and the filler section decreases, making the drainage pipes 7a, 7b more slippery.

[0058] That is, since the parameters are set at the design stage so that the resistance moment is greater than the overturning moment, in order to prevent the retaining wall portion 50 from overturning, it is sufficient to suppress the decrease in the frictional resistance force of the drainage pipes 7a, 7b described above, and it is considered sufficient to support the retaining wall portion 50 with a support member having a function of merely catching. This makes it possible to keep production costs and construction costs low, making it more suitable for practical use than ever before.

[0059] Therefore, in this first embodiment, as shown in Figures 2 and 4, a support member 8 is provided in which a pair of curved members 12a, 12b are arranged opposite each other to form a cylindrical portion 13, the drainage pipe 7 is inserted into the cylindrical portion 13, and the pair of curved members 12a, 12b are fastened to each other with a hexagonal socket bolt 15, so that one of the curved members 12a of the support member 8 is abutted against the retaining wall portion 50 to prevent the retaining wall portion 5 from tipping over.

[0060] Moreover, in this first embodiment, the retaining wall section 50 can be prevented from collapsing simply by inserting the drainage pipe 7 into and fastening the support member 8 having a pair of curved members 12a, 12b arranged opposite each other, thereby eliminating the need for a pressure plate of a complex shape as described in Patent Document 2 and reducing manufacturing costs.

[0061] In addition, since there is no need to form a threaded portion near the open end 10a, even if the ground 6 is hard and pouring becomes difficult, it is sufficient to simply cut the drainage pipe 7 appropriately, and there is no need to cut off the middle part and perform post-processing such as welding as in the conventional method, so a construction method with good workability can be realized with simple ingenuity.

[0062] FIG. 6 is a cross-sectional view of a main part, which diagrammatically shows a first modified example of the first embodiment.

[0063] In Figure 2, one of the curved members 12a that constitute the support member 8 is abutted against the retaining wall portion 50, but in this first modified example, a gap is formed between the curved members 12a, 12b and the retaining wall portion 50, and the gap is filled with a high-strength material to form the base 16.

[0064] That is, in this first modified example, the protruding length of the drainage pipe 7 from the drain hole 3 is slightly increased to form a gap between the retaining wall portion 50 and the support member 8, and a high-strength material is applied to the gap and solidified, thereby forming the base 16.

[0065] Therefore, in the first modified example, the frictional resistance of the drainage pipe 7 can be further reinforced, and the retaining wall portion 50 can be prevented from collapsing more reliably and effectively.

[0066] Here, the high-strength material for forming the base 16 is not particularly limited, and for example, mortar, polymer cement, resin, etc. can be used. Among these, mortar is preferably used because it is relatively inexpensive and has high strength.

[0067] In addition, in the first embodiment described above, a single drain pipe 7 formed as an integral unit is used, but it is also preferable to connect multiple drain pipes with joint members to make them longer as necessary (second variant example).

[0068] FIG. 7 is a front view of a main part of a connecting drainage pipe according to a second modified example of the first embodiment, and FIG. 7(b) is a view taken along the line DD in FIG. 7(a).

[0069] That is, as shown in Fig. 7, the drain pipe 17 has a plurality of concave spiral portions 19 engraved by press work at predetermined intervals on the outer periphery near the open end 18. Although Fig. 7(a) only shows the vicinity of one open end 18, the other open end opposite the open end 18 also has concave spiral portions similar to those in Fig. 7(a) engraved by press work.

[0070] FIG. 8 is a front view of the joint member 20. The joint member 20 is formed in a tubular shape so that multiple drainage pipes 17 can be fitted thereto, and a convex spiral portion 21 is formed on its outer periphery by pressing.

[0071] In this second modified example, the convex spiral portion 21 of the coupling member 20 is screwed into the concave spiral portion 19 of one drain pipe 17 to externally fit the one drain pipe 17 onto the coupling member 20, and then the concave spiral portion 19 of the other drain pipe 17 is screwed into the convex spiral portion 21 of the coupling member 20 to externally fit the other drain pipe 17 onto the coupling member 20, thereby connecting the one drain pipe 17 and the other drain pipe 17 to obtain a long drain pipe.

[0072] In this way, in the second modified example, the drainage pipes 17 are connected to each other via the joint members 20 to form a long drainage pipe, which can be applied to water collection boring works that require long drainage pipes. Therefore, in addition to preventing the retaining wall section 50 from collapsing, even if the pore water pressure suddenly rises due to an earthquake or the like, the pore water pressure in the ground can be dissipated by the many members formed in the tubular member, and landslides due to earthquakes, heavy rain, and the like can be effectively prevented.

[0073] Moreover, in this second modified example, multiple drain pipes 17 are connected to each other via a joint member 20 having a convex spiral portion 21 formed on the outer periphery to make them longer, so that multiple drain pipes 17 can be simply and easily joined together by simply screwing the concave spiral portion 19 of the drain pipe 17 into the convex spiral portion 21 of the joint member 20 without threading the drain pipes 17 or the joint member 20. Moreover, the thickness of the drain pipe 17 near the open end 18 does not become extremely thin, and the strength of the drain pipe 17 does not deteriorate.

[0074] It is also preferable to form a zinc-aluminum-magnesium based plating film on the surface of both the single drainage pipe 7 shown in Figure 3 and the drainage pipe 17 connected via a joint member 20 as in the second modified example, thereby preventing the drainage pipe from corroding even if it is buried in the ground for a long period of time.

[0075] In this second modified example, the drain pipe 17, which has both open ends 18, is connected by a coupling member 20, but if the drain pipe 17 is located at the end, it is preferable to have one end closed, as in Figure 2.

[0076] FIG. 9 is an enlarged view of a main part that typically shows a second embodiment of a reinforcement structure using the retaining wall reinforcement method according to the present invention.

[0077] The second embodiment shows an application example in which the anchor member is fixed to the ground to reinforce the ground.

[0078] That is, in this second embodiment, as in the first embodiment, a retaining wall portion 51 is formed by a stone retaining wall 22, a backfill concrete portion 23 and a backfill crushed stone portion 24, and the retaining wall portion 51 is formed on the ground surface at the end of the ground 25.

[0079] In the second embodiment, an anchor member 27 connected to a long rope-like wire member 26 is fixed to a predetermined position of the ground 25.

[0080] The material of the wire member 26 is not particularly limited, but from the viewpoint of ensuring an anti-rust effect, it is preferable that the wire member 26 be made of a stainless steel material or a carbon fiber material.

[0081] In addition, the diameter and rope length of the wire member 26 are not particularly limited, but for example, the diameter of the wire member 26 is appropriately selected in consideration of the load imposed on the wire member 26 and the frictional resistance force against the ground 26. In addition, the rope length of the wire member 26 is appropriately determined in consideration of the fixing position of the anchor member 27 in the ground 26.

[0082] In addition, a short pipe (tubular member) 29 is inserted into a hole provided in the stone retaining wall 22, and a wedge-shaped member 30 is engaged with the inner surface of the short pipe 29, and the end of the wire member 26 is fixed to the wedge-shaped member 30.

[0083] FIG. 10 shows an outline view of the anchor member 27.

[0084] The anchor member 27 has a main body 27a with one end open and the other end closed, and a D-shaped ring portion 27b attached to the main body 27a. The wire member 26 is attached to the ring portion 27b, and a driving rod 28 can be inserted into one end of the main body 27a.

[0085] FIG. 11 is a diagram showing the details of the wedge-shaped member 30, where (a) is a front view and (b) is a view taken along the line EE in (a).

[0086] That is, the wedge-shaped member 30 is composed of a pair of tapered members 32a, 32b in which the slits 31a, 31b are formed in half. The tapered members 32a, 32b are formed with a hollow interior and are formed in an expanding shape extending from one end face portion 33a, 33b to the other end face portion 34a, 34b, and the opposing faces 35a, 35b of the tapered members 32a, 32b have a large number of teeth (not shown) aligned such that the tooth tips face the other end face portion 34a, 33b.

[0087] 9, one end surface portion 33a, 33b of the wedge-shaped member 30 is engaged with the inner peripheral surface of the short pipe 29, and further the support member 8 shown in the first embodiment is fitted onto the short pipe 29. That is, the short pipe 29 is inserted into the cylindrical portion 13 of the support member 8, similarly to the first embodiment.

[0088] In addition, mortar is applied to the inner surface of the short pipe 29 and the inner surface near the one end face portion 33a, 33b of the tapered members 32a, 32b, and mortar is also filled into the gap formed between the support member 8 and the retaining wall portion 51, thereby forming a base 35.

[0089] The above-mentioned reinforcement structure is constructed through the following steps.

[0090] First, the masonry retaining wall 22 of the retaining wall portion 51 is drilled to form a hole, and then the driving rod 29 (see FIG. 10) is used to drive the anchor member 27 connected to the wire member 26 from the retaining wall portion 51 into the ground 25. Next, after removing the driving rod 29, the wire member 26 is pulled to pivot the anchor member 27, and the anchor member 27 is fixed in a direction perpendicular to the wire member 26. Next, the hole formed in the masonry retaining wall 22 is filled with mortar, and further, before the mortar hardens, the short pipe 29 is inserted into the cylindrical portion 13 of the support member 8, and the short pipe 29 is inserted into the hole. Next, before the mortar hardens, the gap formed between the support member 8 and the retaining wall portion 51 is filled with mortar to form the pedestal 35. In this way, by inserting the short pipe 29 and forming the base 35 before the mortar hardens, mortar is also applied to the inner wall surface near one end face 33a, 33b of the tapered members 32a, 32b. This makes it possible to carry out a series of application operations using mortar simultaneously in one process, which is advantageous in ensuring good workability.

[0091] Finally, while pulling the wire member 26 connected to the anchor member 27, the vicinity of the end of the wire member 26 is clamped from both sides with a pair of tapered members 32a, 32b, and striking is applied from the other end faces 34a, 34b of the tapered members 32a, 32b, thereby engaging the wedge-shaped member 30 with the inner surface of the short pipe 29, thereby completing the series of reinforcement methods.

[0092] In this second embodiment, a gap is provided between the support member 8 and the retaining wall portion 51, and the gap is filled with mortar to form the base 35. However, in order to prevent the retaining wall portion 51 from tipping over, as in the first embodiment, it is sufficient that there is a catch to prevent the retaining wall portion 51 from tipping over, and the base 35 may be omitted if necessary.

[0093] In the second embodiment, the base 35 is made of mortar, but as in the first embodiment, any high-strength material may be used, such as polymer cement, resin, etc.

[0094] In this way, in the second embodiment, the short pipe 29 is inserted into a hole provided in the retaining wall portion 51 so that one end of the short pipe 29 protrudes from the retaining wall portion 51, the end of the wire member 26 is fixed by the wedge-shaped member 30, and the wedge-shaped member 30 is engaged with the inner peripheral surface of the short pipe 29, and a support member 8 having a pair of curved members 12a and 12b arranged opposite to each other is provided to form a cylindrical portion 13, the short pipe 29 is inserted into the cylindrical portion 13, and the pair of curved members 12a and 12b are fastened together by a hexagon socket bolt 15, and at least one of the curved members of the support member 8 is directly or indirectly brought into contact with the retaining wall portion 51 to prevent the retaining wall portion 51 from falling over. As a result, the retaining wall can be effectively prevented from falling over at low cost, as in the first embodiment. In other words, a construction method with good workability can be realized not only for drainage works but also for ground anchor works with simple ingenuity at low cost.

[0095] Furthermore, a gap is formed between the support member 8 and the retaining wall portion 51 and filled with a high-strength material such as mortar, thereby reinforcing the area around the short pipe 29 and more effectively preventing the retaining wall portion 51 from collapsing. In particular, since holes formed in the masonry retaining wall 22 are usually filled with a high-strength material such as mortar after drilling, by carrying out this at the same time as filling the gap with the high-strength material, construction can be carried out efficiently, and the portion formed in the gap also functions as a pedestal 35, ensuring the desired strength.

[0096] Furthermore, by forming the wire member 26 from one selected from a stainless steel material and a carbon fiber material, rusting of the wire member can be suppressed, and good durability can be obtained.

[0097] In this way, the present invention can effectively prevent the retaining wall section 50 from collapsing even when repeated vibrations occur due to earthquakes, etc., by using simple ingenuity without the need for large-scale construction, depending on the construction site and purpose.

[0098] It goes without saying that the present invention is not limited to the above-mentioned embodiment, and can be modified without departing from the scope of the present invention. For example, the type of retaining wall is not limited, and the present invention can be applied to reinforced concrete retaining walls, block masonry retaining walls, etc. [Industrial Applicability]

[0099] To prevent a retaining wall from falling onto the ground at low cost with a simple device even if repeated vibrations occur due to an earthquake or the like. [Explanation of symbols]

[0100] 1. Stone retaining wall 3 Drain holes 6 Ground 7 Drainage pipe (tubular member) 8 Support member 9 holes 10a open end 10b Occlusion 12a, 12b Curved member 13 Cylindrical section 16 Hexagon socket bolt (fastener) 17 Drainage pipe 19 Concave spiral part 20 Joint members 21 Convex spiral part 25 Ground 26 Wire material 27 Anchor member 29 Short pipes (tubular members) 30 Wedge-shaped member 50 Retaining wall 51 Retaining wall

Claims

1. A method for reinforcing a retaining wall, comprising the steps of: driving a tubular member made of a rigid body having a number of holes formed in the longitudinal direction and one open end, into a retaining wall provided with at least one drainage hole, through the drainage hole into the ground so that the open end protrudes from the retaining wall, the method comprising the steps of: a support member having a pair of curved members disposed opposite each other to form a cylindrical portion; The tubular member is inserted into the cylindrical portion, and the pair of curved members are fastened together with a fastener. A method for reinforcing a retaining wall, characterized in that at least one curved member of the support member is abutted against the retaining wall to prevent the retaining wall from collapsing.

2. A retaining wall reinforcement method as described in claim 1, characterized in that a plurality of concave spiral portions are formed at predetermined intervals on the outer periphery of the tubular member, and a plurality of the tubular members are connected via joint members having convex spiral portions formed on their outer periphery to increase the length.

3. 3. A method for reinforcing a retaining wall according to claim 1, further comprising forming a gap between said support member and said retaining wall, and filling said gap with a high-strength material.

4. A method for reinforcing a retaining wall as described in claim 1 or claim 2, characterized in that the tubular member has a closed end on the opposite side to the open end, and by driving the tubular member into the ground through the drainage hole, the ground is compacted and groundwater can be drained from the open end of the tubular member.

5. 3. The method for reinforcing a retaining wall according to claim 1, wherein the tubular member has a surface formed with a zinc-aluminum-magnesium plating film.

6. A method for reinforcing a retaining wall, comprising the steps of: embedding a pivotable anchor member connected to a long wire member into ground from a retaining wall to fix the anchor member in the ground and reinforce the retaining wall, the method comprising the steps of: A tubular member is inserted into a hole provided in the retaining wall so that one end of the tubular member protrudes from the retaining wall, and an end of the wire member is fixed by a wedge-shaped member, and the wedge-shaped member is engaged with an inner peripheral surface of the tubular member, a support member having a pair of curved members disposed opposite each other to form a cylindrical portion; The tubular member is inserted into the cylindrical portion, and the pair of curved members are fastened together with a fastener. A method for reinforcing a retaining wall, characterized in that at least one curved member of the support member is abutted against the retaining wall to prevent the retaining wall from collapsing.

7. 7. The method for reinforcing a retaining wall according to claim 6, further comprising forming a gap between said support member and said retaining wall, and filling said gap with a high-strength material.

8. 8. The method for reinforcing a retaining wall according to claim 6 or 7, characterized in that the wire member is made of one material selected from the group consisting of stainless steel and carbon fiber.

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