Drain pipe, terminal material for drain pipe, and retaining wall drain structure

Abstract

To provide a drain pipe, a terminal material for a drain pipe, and a retaining wall drain structure which more surely suppress lowering of drain performance and backflow prevention performance.SOLUTION: A drain pipe 1 has: a pipe body part 10 which is penetrated into a retaining wall and has a drain hole 102 formed on a peripheral wall 101; a first filter part 11 which is provided on a side closer to a drain outlet side than the drain hole 102 inside the pipe body part 10; a backflow valve 12 which is provided on a side closer to the drain outlet side than the first filter part 11 inside the pipe body part 10; and a second filter part 13 which is provided on a side closer to the drain outlet side than the backflow valve 12 inside the pipe body part 10. The pipe body part 10 has: a body part where the drain hole 102 is formed; and a tubular terminal part 20 which is attachable / detachable to / from the body part from the drain outlet side, and the first filter part 11, the backflow valve 12 and the second filter part 13 may be provided inside the terminal part 20.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a drainage pipe, a terminal member for a drainage pipe, and a retaining wall drainage structure. [Background technology]

[0002] Ground with slopes and vertical surfaces of soil and sand, such as natural slopes, embankments or cuts associated with railway or road construction, and residential land development, is at risk of collapse if precipitation exceeds the soil's infiltration capacity, leading to a rise in the groundwater level and an increase in the soil's moisture content. For this reason, research has been conducted into technologies that drain water from the soil and sand through drainage pipes inserted into the ground, lowering the groundwater level and the soil's moisture content, thereby preventing the collapse of slopes and vertical surfaces. Furthermore, when the sea or river water level is higher than the drainage pipe outlet, drainage pipes used in revetments are preferably used in combination with terminal materials equipped with check valves to prevent water from flowing into the soil and sand through the drainage pipe.

[0003] Patent Document 1 discloses a retractable drainage pipe that penetrates into ground with a slope or vertical surface. Patent Document 2 discloses a check valve that is attached to a drainage hole provided in the side wall of an irrigation channel or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-085183 [Patent Document 2] Publication number 3-22334 Summary of the Invention [Problem to be solved by the invention]

[0005] The drainage pipe disclosed in Patent Document 1 is provided with multiple drainage holes and an inflow prevention material is installed inside the inner pipe to prevent sediment from entering through the drainage holes. This significantly reduces the inflow of sediment through the drainage holes when the drainage pipe is inserted and when draining. Furthermore, the check valve disclosed in Patent Document 2 can prevent sediment from flowing back into the drainage pipe when the water level is higher than the drainage outlet of the drainage pipe. However, the drainage pipe disclosed in Patent Document 1 does not provide sufficient measures to prevent sediment accumulation within the drainage pipe, as sediment accumulates between the inner surface of the drainage pipe and the inflow prevention material or falls into the pipe. Furthermore, the check valve disclosed in Patent Document 2 is intended to prevent backflow of sediment and rolling of the check valve using a perforated plate installed on the drainage outlet side. However, while the perforated plate can prevent the inflow of coarse sediment, it cannot prevent the inflow of fine sediment suspended in water that flows in through the drainage pipe opening due to a rise in the water level. That is, Patent Document 2 does not anticipate preventing the backflow of fine sediment (Figure 5). As a result, there is a concern that a small amount of sediment may continue to flow in from the drainage hole of the drainage pipe disclosed in Patent Document 1, or that the backflowing sediment may accumulate around the check valve and impede the operation of the check valve, resulting in a problem that it is not possible to reliably prevent a decline in drainage performance and backflow prevention performance.

[0006] The present invention was devised in consideration of the above-mentioned problems, and its purpose is to provide drainage pipes, terminal materials for drainage pipes, and retaining wall drainage structures that more reliably suppress the decline in drainage performance and backflow prevention performance. [Means for solving the problem]

[0007] The drainage pipe of the first invention is characterized by comprising a tubular body portion that is inserted into a retaining wall and has drainage holes formed in the peripheral wall, a first filter portion that is provided inside the tubular body portion on the drainage outlet side of the drainage holes, a check valve that is provided inside the tubular body portion on the drainage outlet side of the first filter portion, and a second filter portion that is provided inside the tubular body portion on the drainage outlet side of the check valve.

[0008] The drain pipe of the second invention is characterized in that, in the first invention, the tubular body portion has a main body portion in which the drain hole is formed and a tubular terminal portion that can be attached and detached to the main body portion from the drain outlet side, and the first filter portion, the check valve, and the second filter portion are provided inside the terminal portion.

[0009] The drainage pipe of the third invention is characterized in that, in the first or second invention, the check valve is freely openable and closable in the internal space formed between the first filter section and the second filter section.

[0010] The terminal member for a drainage pipe in the fourth invention is a terminal member for a drainage pipe that is inserted into a retaining wall and attached to a pipe body having drainage holes formed in the peripheral wall, and is characterized in that it comprises a tubular terminal portion that can be attached and detached to the pipe body, a first filter portion provided inside the terminal portion, a check valve provided inside the terminal portion on the drainage outlet side of the first filter portion, and a second filter portion provided inside the terminal portion on the drainage outlet side of the check valve.

[0011] The retaining wall drainage structure of the fifth invention is characterized by comprising a retaining wall, a tubular body portion that penetrates the retaining wall and has drainage holes formed in the peripheral wall, a first filter portion that is provided inside the tubular body portion on the drainage outlet side of the drainage holes, a check valve that is provided inside the tubular body portion on the drainage outlet side of the first filter portion, and a second filter portion that is provided inside the tubular body portion on the drainage outlet side of the check valve. [Effects of the Invention]

[0012] According to the first to third inventions, the drain pipe includes a first filter section provided closer to the drain outlet than the drain hole, a check valve provided closer to the drain outlet than the first filter section, and a second filter section provided closer to the drain outlet than the check valve. This prevents sediment from accumulating near the check valve and hindering its operation. This more reliably prevents a decline in the drainage performance and backflow prevention performance of the drain pipe.

[0013] In particular, according to the second aspect of the present invention, the drain pipe has a tubular terminal section that can be attached and detached from the drain outlet side to the main body, and the first filter section, the check valve, and the second filter section are provided inside the terminal section. This makes it easy to replace each filter section, thereby improving the manageability of the drain pipe.

[0014] In particular, according to the third aspect of the present invention, the check valve is configured to be able to open and close freely in the internal space formed between the first filter section and the second filter section, which further prevents the check valve from being obstructed, thereby more reliably preventing a decline in the drainage performance and backflow prevention performance of the drain pipe.

[0015] According to a fourth aspect of the present invention, a terminal member for a drainage pipe includes a first filter section provided inside the terminal section, a check valve provided closer to the drain outlet than the first filter section, and a second filter section provided closer to the drain outlet than the check valve. This prevents sediment from accumulating near the check valve and hindering its operation. This more reliably prevents a decline in the drainage performance and backflow prevention performance of the drainage pipe.

[0016] According to the fifth aspect of the present invention, the retaining wall drainage structure includes a first filter unit provided closer to the drain outlet than the drainage hole, a check valve provided closer to the drain outlet than the first filter unit, and a second filter unit provided closer to the drain outlet than the check valve. This prevents sediment from accumulating near the check valve and hindering its operation. This more reliably prevents a decline in the drainage performance and backflow prevention performance of the retaining wall drainage structure. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a drainage pipe and a retaining wall drainage structure according to this embodiment. [Figure 2] FIG. 2 is a schematic front view showing an example of a drainage pipe and a retaining wall drainage structure according to this embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing an example of a drainage pipe in this embodiment. [Figure 4] 4(a) and 4(b) are images showing an example of a drainage pipe in this embodiment. [Figure 5] 5(a) is a cross-sectional view taken along line AA corresponding to FIG. 3, and FIG. 5(b) is a front view corresponding to FIG. [Figure 6] FIG. 6(a) is a cross-sectional view showing an example of a terminal member for a drainage pipe in this embodiment, and FIG. 6(b) is an image showing an example of a terminal member for a drainage pipe in this embodiment. [Figure 7] FIG. 7 is a schematic cross-sectional view showing a first modified example of the drainage pipe in this embodiment. [Figure 8] FIG. 8 is a schematic cross-sectional view showing a second modified example of the drainage pipe in this embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view showing an example of a drainage method for the drainage pipe in this embodiment. [Figure 10] FIG. 10(a) is a cross-sectional view showing an example of a drainage method for a drainage pipe in this embodiment, and FIG. 10(b) is a schematic cross-sectional view showing a modified example of a drainage method for a drainage pipe in this embodiment. [Figure 11] Figure 11(a) is a cross-sectional view showing an example of a method for preventing backflow in a drainage pipe in this embodiment, and Figure 11(b) is a schematic cross-sectional view showing a modified example of a method for preventing backflow in a drainage pipe in this embodiment. [Figure 12] 12(a) to 12(c) are images showing an example of a method for constructing a retaining-wall drainage structure in this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] An example of a drainage pipe 1 as an embodiment of the present invention will be described in detail below with reference to the drawings. In each drawing, a first direction X is defined, one direction perpendicular to the first direction X is defined as a second direction Y, and a direction perpendicular to both the first direction X and the second direction Y is defined as a third direction Z. The configurations in each drawing are shown schematically for the purpose of explanation, and for example, the size of each component and the size comparison between components may differ from the drawings.

[0019] (100 retaining wall drainage structures, 1 drainage pipe) An example of the drainage pipe 1 and the retaining wall drainage structure 100 in this embodiment will be described with reference to the drawings.

[0020] 1, the retaining wall drainage structure 100 includes a retaining wall 9 containing soil such as cut earth or fill on a coast, river, inland area, or the like, and a drainage pipe 1 that penetrates the retaining wall 9. The retaining wall 9 includes, for example, ground 91 and a retaining wall construction 92 provided on the surface of the ground 91. The retaining wall drainage structure 100 is constructed on coastal revetment retaining walls and river revetment retaining walls facing water, and can also be constructed on retaining walls of inland embankments and cut earth that face water due to rising water levels caused by external flooding (such as river flooding) or inland flooding.

[0021] The drainage pipe 1 is penetrated in a penetration direction P (first direction X in FIG. 1 ) into ground 91 on the surface of which, for example, a retaining wall construction 92 is constructed. More specifically, the drainage pipe 1 is penetrated by being inserted into a borehole H drilled in a retaining wall surface F of the retaining wall construction 92, for example, and then driven into the ground 91. At this time, the drainage pipe 1 drains moisture such as rainwater and groundwater contained inside the ground 91 into the external space O, thereby preventing the ground 91 from collapsing.

[0022] The drainage pipe 1 includes a tubular body portion 10. The drainage pipe 1 is extended, for example, horizontally, and the tip of the tubular body portion 10 is inserted into the retaining wall 9 with the horizontal direction being the insertion direction P. Here, the tip refers to a first end portion 10f of the pipe end of the tubular body portion 10 on the insertion direction P side.

[0023] The tubular portion 10 can drain water from inside the retaining wall 9 into the interior of the tubular portion 10 through drainage holes 102 drilled in the peripheral wall 101. The tubular portion 10 can also drain water from inside the tubular portion 10 to the external space O outside the retaining wall 9, using its rear end exposed on the retaining wall surface F as a drainage outlet. Here, the rear end refers to the second end 10b of the tubular portion 10 on the drainage outlet side, which is opposite the penetration direction P.

[0024] That is, the drainage pipe 1 uses, for example, the second end 10b of the tubular portion 10 as a drainage outlet to drain water inside the tubular portion 10 into the external space O. Here, the external space O refers to the space horizontally adjacent to the retaining wall 9. The external space O may be filled with, for example, the atmosphere, or may be filled with the atmosphere when the water level is h1 lower than the height of the discharge outlet, and may be filled with river water or seawater when the water level is h2 higher than the height of the discharge outlet.

[0025] As shown in Figure 2, for example, a plurality of drainage pipes 1 may penetrate the same retaining wall 9 at appropriate intervals along the horizontal direction (third direction Z in Figure 2). That is, the retaining wall drainage structure 100 may include a plurality of drainage pipes 1 (1a, 1b, 1c). Also, a plurality of drainage pipes 1 may penetrate the same retaining wall 9 at appropriate intervals along the vertical direction (second direction Y in Figure 2).

[0026] Next, the configuration of the drainage pipe 1 will be described in detail.

[0027] The drainage pipe 1 includes a pipe portion 10, a first filter portion 11, a check valve 12, and a second filter portion 13, as shown in FIG.

[0028] <Tube body part 10> The tubular portion 10 is inserted into the retaining wall 9. The tubular portion 10 has a tubular shape in which, for example, a first end 10f, which is the leading end, is closed and a second end 10b, which is the rear end, is open.

[0029] The pipe portion 10 has a tubular peripheral wall 101, as shown in FIG. 4(a), for example. The pipe portion 10 has drainage holes 102 of a predetermined diameter (for example, 5 mm diameter) formed in the peripheral wall 101 at appropriate intervals (for example, 10 mm intervals). In addition, the pipe portion 10 is provided with a water-permeable sediment inflow prevention material 103 on the inner circumferential surface side of the peripheral wall 101 so as to block the drainage holes 102. In this case, water contained in the retaining wall 9 is drained into the inside of the pipe portion 10, while sediment contained in the retaining wall 9 is less likely to flow in, preventing interference with the operation of the check valve 12. This reliably prevents a decrease in the drainage performance and backflow prevention performance of the drainage pipe 1.

[0030] The tubular body portion 10 may have a drainage pipe terminal member 2 at the second end portion 10b, which is the end portion on the drainage outlet side, as shown in Fig. 3, for example. The tubular body portion 10 may have, for example, a main body portion, which is the portion of the tubular body portion 10 excluding the drainage pipe terminal member 2, and a tubular drainage pipe terminal member 2 (terminal portion 20) that is detachable from the main body portion from the drainage outlet side.

[0031] For example, a plated steel pipe is used as the material of the tubular body 10. For example, a Telesco Drain (registered trademark) having an extrusion structure in which a plurality of pipes of different diameters are combined may be used as the tubular body 10.

[0032] <Sediment inflow prevention material 103> The sediment inflow prevention material 103 is, for example, a cylindrical body (columnar body or tubular body) made of a permeable sheet, and is fitted inside the tubular body 10. The sediment inflow prevention material 103 is, for example, fixed to the inner circumferential surface of the tubular body 10. Note that the sediment inflow prevention material 103 may be a cylinder integrated with a perforated pipe made of resin or the like to ensure drainage performance and maintain its shape, or it may be a perforated pipe made of resin or the like alone, without using a cylindrical pipe made of permeable sheet. Furthermore, the sediment inflow prevention material 103 may be a perforated cylinder (columnar body or tubular body) made of stainless steel mesh or punched metal, etc., that has rigidity capable of withstanding soil pressure and water pressure, instead of a permeable sheet. Note that the shape of the sediment inflow prevention material 103 may be a solid cylinder, a rectangular column, or a hollow rectangular tube, as long as it can be fitted inside the drainage pipe 1.

[0033] The sediment inflow prevention material 103 may be any material that has a certain amount of voids that allow water to pass through and has a resilience that can withstand soil pressure and water pressure, and may be a fiber material formed into a three-dimensional mesh shape of polypropylene or a porous material such as foamed resin. However, by using the above-mentioned columnar or cylindrical sediment inflow prevention material 103 that allows water to pass through, the purpose can be achieved simply by loading it inside the tubular part 10, which is preferable because the insertion work is easy.

[0034] 4(b), the sediment inflow prevention material 103 may be provided on the outer peripheral surface side of the peripheral wall 101 so as to block the drainage hole 102. In this case as well, it is difficult for sediment contained in the retaining wall 9 to flow in, preventing the operation of the check valve 12 from being hindered, and it is possible to reliably prevent a decrease in the drainage performance and backflow prevention performance of the drainage pipe 1.

[0035] <First filter section 11> As shown in FIG. 3, for example, the first filter portion 11 is provided inside the tubular portion 10 closer to the drain outlet side (second end portion 10b side) than the drain hole 102.

[0036] The first filter section 11 is provided inside the tubular section 10 closer to the end in the penetration direction P (towards the first end section 10f) than the check valve 12. That is, the first filter section 11 is provided inside the tubular section 10 between the check valve 12 and an area of ​​the peripheral wall 101 where the drainage holes 102 are formed.

[0037] The first filter section 11 may be provided, for example, by being fixed to the peripheral wall 101 inside the tubular section 10, or may be provided by being fixed to the drainage pipe terminal member 2, or may be provided by being fixed to the check valve 12. The first filter section 11 may be fixed to the peripheral wall 101, the drainage pipe terminal member 2, or the check valve 12 with a resin adhesive.

[0038] The first filter section 11 is made of, for example, chemical fiber or nonwoven fabric, and is a known filter that does not allow coarse soil and fine soil to pass through.

[0039] <Check valve 12> The check valve 12 is provided inside the tubular body portion 10 closer to the drain outlet side (second end portion 10b side) than the first filter portion 11.

[0040] The check valve 12 is provided inside the tubular portion 10 closer to the end (first end 10f side) in the penetration direction P than the second filter portion 13. That is, the check valve 12 is provided inside the tubular portion 10 between the first filter portion 11 and the second filter portion 13.

[0041] The check valve 12 is provided so as to be able to open and close freely so as to drain water in the drainage direction inside the tubular portion 10. The check valve 12 may be provided, for example, by being fixed to the peripheral wall 101 inside the tubular portion 10, or may be provided by being fixed to the terminal member 2 for the drainage pipe.

[0042] The check valve 12 has a swing-type structure having a valve element 121 and a valve seat 122, as shown in Figures 3 and 5(a), for example. The valve seat 122 is provided with a check valve water hole 123 through which, for example, wastewater flows. The valve element 121 is fixed to the valve seat 122 via a screw B122 so as to be able to open and close freely. When draining water from the inside of the tubular portion 10 toward the external space O, the valve element 121 opens the check valve water hole 123 to drain water, and when water flows back from the external space O toward the inside of the tubular portion 10, the valve element 121 closes the check valve water hole 123 to prevent backflow.

[0043] In addition, since the first filter section 11 is provided on the back side of the valve seat 122 in the cross-sectional view of Figure 5(a), solid components such as soil and sand in the fluid in the drainage pipe 1 are separated when the fluid passes through the check valve water passage 123.

[0044] The check valve 12 may be of any structure such as the swing type described above, a lift type, a disc type, or the like.

[0045] The check valve 12 is made of, for example, ethylene propylene rubber.

[0046] <Second filter section 13> As shown in Fig. 3, for example, the second filter section 13 is provided inside the pipe section 10 closer to the drainage outlet (towards the second end 10b) than the check valve 12. In this case, sediment does not accumulate near the check valve 12, preventing the operation of the check valve 12 from being hindered. This more reliably prevents the drainage performance and backflow prevention performance of the drainage pipe 1 from decreasing. Furthermore, the retaining wall drainage structure 100 that uses the drainage pipe 1 can more reliably prevent the drainage performance and backflow prevention performance from decreasing.

[0047] The second filter section 13 is spaced apart from the first filter section 11, forming an internal space Q therebetween. Here, the check valve 12 is capable of freely opening and closing in the internal space Q. In this case, it is possible to further prevent the operation of the check valve 12 from being obstructed. This makes it possible to more reliably prevent the drainage performance and backflow prevention performance of the drainage pipe 1 from being reduced.

[0048] The second filter section 13 may be provided, for example, by being fixed to the peripheral wall 101 inside the tubular section 10, or may be provided by being fixed to the drainage pipe terminal member 2. The second filter section 13 may be fixed to the peripheral wall 101 or the drainage pipe terminal member 2 with a resin adhesive.

[0049] The second filter section 13 may be fixed to the peripheral wall 101 or the drainage pipe terminal member 2 by being sandwiched between a pair of screens 131 fixed to the peripheral wall 101 or the drainage pipe terminal member 2. The screen 131 has screen water-passing holes 132 drilled therein to allow drainage to flow, as shown in FIG. 5(b), for example. The screen 131 may also be fixed to the tubular section 10 or the drainage pipe terminal member 2 (terminal portion 20) with bolts B20 or the like.

[0050] The second filter section 13 may be, for example, the same filter as the first filter section 11. The screen 131 may be made of, for example, stainless steel (SUS304). In this case, the second filter section 13 can prevent the backflow of fine soil and sand, and the screen 131 can prevent the backflow of coarse soil and sand.

[0051] <Drainage pipe terminal material 2> The drainage pipe terminal member 2 may be, for example, the second end 10b of the tubular body 10, as shown in Figure 3. The drainage pipe terminal member 2 has a first end 10f and is detachably connected to the main body portion in which a drainage hole 102 is formed. The drainage pipe terminal member 2 may have, for example, a tubular shape with both ends open.

[0052] As shown in Figures 6(a) and 6(b), the terminal member 2 for a drainage pipe has a terminal portion 20. The terminal member 2 for a drainage pipe may further have an extension pipe 21, for example.

[0053] <Terminal unit 20> The terminal portion 20 is tubular with both ends open. The terminal portion 20 is detachable from the main body portion included in the tubular portion 10. The dimensions of the terminal portion 20 are, for example, a length L1 of approximately 95 mm to approximately 338 mm, an outer diameter R1 of approximately φ60 mm to approximately φ178 mm, an end outer diameter R2 of approximately φ55.5 mm to approximately φ160.5 mm, an inner diameter R3 of approximately φ48 mm to approximately φ165 mm, an end notch width W1 of approximately 4.5 mm, and a wall thickness W2 of approximately 11 mm to 26 mm.

[0054] The terminal portion 20 has, for example, a third end portion 20f and a fourth end portion 20b. The third end portion 20f refers to a portion of the tube end of the terminal portion 20 near one open end. The fourth end portion 20b refers to a portion of the tube end of the terminal portion 20 near the other open end opposite the third end portion 20f. As shown in FIG. 3, for example, the third end portion 20f and the fourth end portion 20b are notched to have an end outer diameter R2 that is smaller than the outer diameter R1 of the terminal portion 20, and are connected by fitting with another tube at the notched portion.

[0055] 3, the terminal unit 20 is detachably attached to the main body by, for example, fitting the rear end of the main body into the third end 20f. Also, the terminal unit 20 is detachably attached to the extension pipe 21 by, for example, fitting one end of the extension pipe 21 into the fourth end 20b.

[0056] The terminal portion 20 may be provided with a first filter portion 11, a check valve 12, and a second filter portion 13 therein, as shown in Fig. 6(a), for example. In this case, each filter portion (first filter portion 11, second filter portion 13) can be easily replaced. This can improve the manageability of the drainage pipe 1.

[0057] In this case, the first filter section 11 is provided, for example, inside the terminal section 20, on one end side (third end 20f in Figure 6(a)). The check valve 12 is provided inside the terminal section 20, on the other end side closer to the drain outlet than the first filter section 11 (fourth end 20b in Figure 6(a)). The second filter section 13 is provided inside the terminal section 20, on the other end side closer to the drain outlet than the check valve 12. In this case, sediment does not accumulate near the check valve 12, preventing the operation of the check valve 12 from being obstructed. This makes it possible to more reliably prevent a decline in drainage performance and backflow prevention performance for a drainage pipe 1 using a drainage pipe terminal member 2.

[0058] ABS resin, for example, is used as the material for the terminal portion 20. For example, a "GF type: screened weep hole" made by Chubu Bika Enterprise Co., Ltd., which is conventionally used for draining water from the base plates of irrigation channels, regulating ponds, and dams, may be used as the terminal portion 20.

[0059] <Extension pipe 21> The extension pipe 21 may be, for example, the second end 10b of the tubular body portion 10. The extension pipe 21 is detachably connected to the main body portion having the first end 10f and the terminal portion 20. The shape of the extension pipe 21 is, for example, a tubular shape with both ends open.

[0060] The extension pipe 21 has, for example, a fifth end 21f and a sixth end 21b. The fifth end 21f refers to a portion of the pipe end of the extension pipe 21 near one open end. The sixth end 21b refers to a portion of the pipe end of the extension pipe 21 near the other open end opposite the fifth end 21f. In the example of FIG. 6(a), the extension pipe 21 is detachably attached to the terminal portion 20, for example, by fitting the fourth end 20b and the fifth end 21f of the terminal portion 20 together. The sixth end 21b is exposed to the retaining wall surface F and functions as a drain port for draining water inside the pipe portion 10 to the external space O.

[0061] The extension pipe 21 is made of the same material as the terminal portion 20, for example.

[0062] (Modification of drainage pipe 1) The first filter section 11 may be fixed to the inner circumferential surface of the main body portion of the tubular section 10, as shown in FIG. 7 . Here, if the check valve 12 is provided inside the terminal section 20, the first filter section 11 prevents sediment from flowing into the terminal section 20, making it even less likely for sediment to accumulate near the check valve 12 and further preventing the operation of the check valve 12 from being obstructed. This more reliably prevents a decrease in drainage performance and backflow prevention performance of the drainage pipe 1 using the drainage pipe terminal member 2. In this case, the first filter section 11 may be fixed to the inner circumferential surface of the tubular section 10 with, for example, a resin adhesive. The first filter section 11 may be fixed to the inner circumferential surface of the tubular section 10 by, for example, engaging with the third end 20f of the terminal section 20.

[0063] The terminal portion 20 may also be fixed to the inner circumferential surface of the main body portion of the tubular portion 10, as shown in FIG. 8 . The drainage pipe terminal member 2 may also be detachably fixed to the inner circumferential surface of the main body portion of the tubular portion 10, for example. In this case, soil and sand do not flow in from the connection between the terminal portion 20 and the main body portion, and the terminal portion 20 is not exposed to the retaining wall 9, thereby suppressing deterioration or damage to the terminal portion 20. Furthermore, when at least one of the first filter portion 11, the check valve 12, and the second filter portion 13 is provided inside the terminal portion 20, suppressing deterioration or damage to the first filter portion 11, the check valve 12, and the second filter portion 13 can be suppressed. This improves the economic efficiency of the drainage pipe 1.

[0064] (Drainage method of retaining wall drainage structure 100) An example of a drainage method for the retaining wall drainage structure 100 in this embodiment will be described with reference to the drawings. In this embodiment, an example using a drainage pipe 1 including a tubular body portion 10 having a terminal portion 20 will be described, but the same applies to a case where the tubular body portion 10 does not have the terminal portion 20.

[0065] 9, the drainage pipe 1 constituting the retaining wall drainage structure 100 drains water contained in the ground 91 of the retaining wall 9 through the drainage holes 102 in a first drainage direction f1 from the ground 91 toward the inside of the pipe body portion 10. The drainage pipe 1 then drains water from, for example, the inside of the pipe body portion 10 in a second drainage direction f2 from the first end portion 10f toward the terminal portion 20 on the drainage outlet side. The drainage pipe 1 then drains water from, for example, the inside of the terminal portion 20 in a third drainage direction f3 from the third end portion 20f on the main body side toward the second end portion 10b on the drainage outlet side.

[0066] 10(a), for example, the first filter unit 11 filters the water drained in the third drainage direction f3 inside the terminal unit 20 to prevent the passage of solid components such as coarse and fine sediment, and then passes the liquid components of the drained water. The check valve 12 then passes the water that has passed through the first filter unit 11 in the third drainage direction f3. The second filter unit 13 then passes the water that has passed through the check valve 12 in the third drainage direction f3. As a result, the water contained in the ground 91 is filtered without solid components such as sediment accumulating near the check valve 12, and then drained into the external space O.

[0067] 10(b), the first filter unit 11 may filter the water drained inside the main body in the second drainage direction f2 to prevent solid components such as coarse and fine sediment from passing through, and then allow the liquid components of the drained water to pass through. In this case as well, the water contained in the ground 91 is filtered without solid components such as sediment accumulating near the check valve 12, and then drained into the external space O.

[0068] (Method for preventing backflow in retaining wall drainage structure 100) An example of a backflow prevention method for the retaining wall drainage structure 100 in this embodiment will be described with reference to the drawings. In this embodiment, an example using a drainage pipe 1 similar to the drainage method described above will be described.

[0069] 11(a), for example, the second filter unit 13 filters the water flowing back in the fourth direction f4 inside the extension pipe 21 to prevent the passage of solid components such as coarse and fine sediment contained therein, and then passes the liquid components of the backflowing water. Thereafter, the check valve 12 stops the water that has passed through the second filter unit 13 in the fourth direction f4 in the internal space Q. Thereafter, the second filter unit 13 allows the water that has been stopped by the check valve 12 to pass in the fifth direction f5.

[0070] As a result, water that flows back into the retaining wall drainage structure 100 is filtered without solid components such as sediment accumulating near the check valve 12, and is then stopped in the internal space Q by the check valve 12, and is then drained into the external space O. This prevents sediment from accumulating near the check valve 12, preventing the operation of the check valve 12 from being obstructed. This makes it possible to more reliably prevent the drainage performance and backflow prevention performance of the drainage pipe 1 from decreasing.

[0071] FIG. 11(b) shows a method of preventing backflow in the drainage pipe 1 corresponding to FIG. 10(b), and in this case too, backflow can be prevented in the same way as in FIG. 11(a).

[0072] (Method for constructing retaining wall drainage structure 100) An example of a method for constructing a retaining wall drainage structure 100 in this embodiment will be described with reference to the drawings. In this embodiment, an example will be described in which a drainage pipe 1 including a tubular body portion 10 having a terminal portion 20 is used, but the same applies to a case in which the tubular body portion 10 does not have the terminal portion 20.

[0073] As shown in FIG. 12(a), for example, a worker inserts the drainage pipe 1 into a borehole H drilled in advance in the surface F of the retaining wall 9. After pre-boring the ground 91, for example, the worker inserts the drainage pipe 1 into the retaining wall 9 while holding the end of the pipe body 10 on the drainage outlet side. For example, without pre-boring the ground 91, the worker may insert the drainage pipe 1 into the retaining wall 9 while applying vibration to the pipe body 10 using a small heavy machine or a handheld pile driver.

[0074] Immediately after the drainage pipe 1 is inserted into the retaining wall 9, a space is formed between the terminal portion 20 and the borehole H, as shown in FIG. 12(b), for example. If this space is not sealed, water may flow back from the external space O into the borehole H, and as a result, the water contained in the retaining wall 9 may not be able to be drained. Therefore, as shown in FIG. 12(c), for example, the worker caulks the space between the terminal portion 20 and the borehole H, thereby forming a caulked borehole H'. This makes it possible to construct a retaining wall drainage structure 100 that can drain water contained in the retaining wall 9.

[0075] According to this embodiment, the drain pipe 1 comprises a first filter section 11 provided closer to the drain outlet than the drain hole 102, a check valve 12 provided closer to the drain outlet than the first filter section 11, and a second filter section 13 provided closer to the drain outlet than the check valve 12. This prevents sediment from accumulating near the check valve 12, preventing the operation of the check valve 12 from being obstructed. This more reliably prevents the drainage performance and backflow prevention performance of the drain pipe 1 from declining.

[0076] Furthermore, according to this embodiment, the drain pipe 1 has a tubular terminal portion 20 that can be attached and detached from the drain outlet side to the main body, and the first filter portion 11, check valve 12, and second filter portion 13 are provided inside the terminal portion 20. This makes it possible to easily replace each filter portion (first filter portion 11, second filter portion 13). This improves the manageability of the drain pipe 1.

[0077] Furthermore, according to this embodiment, the check valve 12 can be opened and closed freely in the internal space Q formed between the first filter section 11 and the second filter section 13. This further prevents the operation of the check valve 12 from being obstructed. This makes it possible to more reliably prevent the drainage performance and backflow prevention performance of the drainage pipe 1 from being reduced.

[0078] Furthermore, according to this embodiment, the drainage pipe terminal member 2 comprises a first filter section 11 provided closer to the drainage outlet than the drainage hole 102, a check valve 12 provided closer to the drainage outlet than the first filter section 11, and a second filter section 13 provided closer to the drainage outlet than the check valve 12. This prevents sediment from accumulating near the check valve 12, preventing the operation of the check valve 12 from being obstructed. This makes it possible to more reliably prevent the drainage performance and backflow prevention performance of the drainage pipe 1 from declining.

[0079] Furthermore, according to this embodiment, the retaining wall drainage structure 100 includes a first filter section 11 provided inside the terminal section 20, a check valve 12 provided closer to the drainage outlet than the first filter section 11, and a second filter section 13 provided closer to the drainage outlet than the check valve 12. This prevents sediment from accumulating near the check valve 12, preventing the operation of the check valve 12 from being obstructed. This makes it possible to more reliably prevent the drainage performance and backflow prevention performance of the drainage pipe 1 from declining.

[0080] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0081] 100 Retaining wall drainage structure 1 drain pipe 10. Tube body 101 Peripheral wall 102 Drain hole 103 Sediment inflow prevention material 10f 1st end 10b 2nd end 11 First filter section 12 Check valve 121 Valve body 122 Valve seat 123 Check valve water vent 13 Second filter section 131 screens 132 Screen water hole 2. Drainage pipe terminals 20 Terminal 20f 3rd end 20b 4th end 21 Extension pipe 21f 5th end 21b 6th end 9 Retaining Wall 91 Ground 92 Retaining wall construction F. Retaining wall surface H perforation H' Caulked drilled hole O External space Q interior space P penetration direction f1, f2, f3 drainage direction

Claims

1. a pipe portion that penetrates the retaining wall and has drainage holes formed in the peripheral wall; a first filter section provided inside the tubular section on the drain outlet side of the drain hole; a check valve provided inside the tubular body portion on the drain outlet side of the first filter portion; a second filter section provided inside the tubular section on the drain outlet side of the check valve; To be prepared A drainage pipe characterized by:

2. The tubular body portion has a main body portion in which the drainage hole is formed and a tubular terminal portion that is detachable from the main body portion from the drain outlet side, The first filter section, the check valve, and the second filter section are provided inside the terminal section. The drainage pipe according to claim 1 .

3. The check valve is openable and closable in an internal space formed between the first filter section and the second filter section. The drainage pipe according to claim 1 or 2, characterized in that

4. A drainage pipe terminal member that is attached to a pipe body that penetrates a retaining wall and has drainage holes in the peripheral wall, a tubular terminal portion detachably attached to the tubular body; a first filter portion provided inside the terminal portion; a check valve provided inside the terminal portion on the drain outlet side of the first filter portion; a second filter section provided inside the terminal section on the drain outlet side of the check valve; To be prepared A terminal material for drainage pipes characterized by:

5. Retaining walls and A pipe portion that penetrates the retaining wall and has drainage holes formed in the peripheral wall; a first filter section provided inside the tubular section on the drain outlet side of the drain hole; a check valve provided inside the tubular body portion on the drain outlet side of the first filter portion; a second filter section provided inside the tubular section on the drain outlet side of the check valve; To be prepared A retaining wall drainage structure characterized by:

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