Water guide member for drainage pipe and method for installing drainage pipe

Abstract

To provide a water guide part forming member for a drain pipe regarding the drain pipe buried in the ground having a slope face or an inclined face, easily inserted into a cylindrical part and causing no space between an inner peripheral surface of the cylindrical part and the outer peripheral surface of a filter member, and a construction method of the drain pipe.SOLUTION: A water guide part forming member 30 has an expandable member 31 expandable in the radial direction and a filter member 32 covering an outer peripheral surface of the expandable member 31. The water guide part forming member 30 is inserted into a cylindrical part 2 in a state of having an outer diameter smaller than an inner diameter of the cylindrical part 2. Then, by expanding the expandable member 31, a space between the outer peripheral face of the filter member 32 and the inner peripheral face of the cylindrical part 2 is closed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a water conveyance section forming member for forming a water conveyance section disposed in a drainage pipe buried in the ground, and a method for constructing the drainage pipe. [Background technology]

[0002] In ground with slopes or embankments, such as cut earth, drainage pipes are buried up to the slopes or embankments to quickly drain soil water caused by rainfall. Holes are provided in the peripheral wall of the drainage pipe, and soil water seeps into the drainage pipe through these holes and is then discharged to the outside. When such drainage pipes are installed in places where the frequency of drainage varies significantly depending on the season, they are susceptible to blockage due to the inflow of sediment and other debris, resulting in a deterioration of the drainage function. Pipe blockages can also occur due to plants and bacteria. To prevent such blockages, a filter element (water-conducting material) is placed inside the pipe body (tubular portion) of the drainage pipe (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-045632 Summary of the Invention [Problem to be solved by the invention]

[0004] To prevent soil and sand from flowing into the drainage pipe, it is desirable to eliminate any gaps between the filter element and the pipe body. In other words, it is desirable for the diameter of the filter element to be approximately the same as the inner diameter of the pipe body. However, if the diameter of the filter element is approximately the same as the inner diameter of the pipe body, the friction between the filter element and the inner surface of the pipe body increases when inserting the filter element into the pipe body, making it difficult to insert the filter element into the pipe body. In order to reduce the friction and make it easier to insert the filter element into the pipe body, filter elements with a diameter smaller than the inner diameter of the pipe body have been used in practice.

[0005] In view of the above background, the present invention aims to provide a water guide section forming member for a drainage pipe, which is easy to insert into the tubular section (pipe main body) and does not leave a gap between the inner surface of the tubular section and the outer surface of the filter member, and a method for installing the drainage pipe. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the present invention is a water-conducting section forming member (30, 43) for a drainage pipe (1, 41) buried in the ground, which comprises an expandable member (31) that extends in a predetermined direction, has an outer peripheral surface, and is expandable in a radial direction perpendicular to the predetermined direction, and a filter member (32) that extends in the predetermined direction, covers the outer peripheral surface of the expandable member, has voids through which water can pass, and is extensible in the circumferential direction.

[0007] According to this aspect, the outer diameter of the filter member can be increased by expanding the expandable member after inserting the water guide portion-forming member into the tubular portion. Therefore, by inserting the water guide portion-forming member into the tubular portion while the water guide portion-forming member has an outer diameter smaller than the inner diameter of the tubular portion of the drainage pipe, the water guide portion-forming member can be easily inserted into the tubular portion. Furthermore, by expanding the expandable member after insertion, the gap between the inner circumferential surface of the tubular portion and the outer circumferential surface of the filter member can be filled, thereby preventing sediment from flowing into the drainage pipe.

[0008] In the above embodiment, the device may further include a core material (44) extending in the predetermined direction and embedded within the expandable member (31).

[0009] According to this aspect, the core material makes it difficult for the water guide portion forming member to bend, making it even easier to insert the water guide portion forming member into the tubular portion.

[0010] In the above embodiment, the expandable member (31) may include a polymer absorbent material that expands by absorbing water.

[0011] According to this aspect, the expandable member expands with water, thereby reducing the impact on the environment around the construction site.

[0012] In the above aspect, the device may further include a membrane member (33) that is expandable in diameter and permeable to water, and that is arranged between the expandable member (31) and the filter member (32) so as to cover the outer peripheral surface of the expandable member (31) in the circumferential direction.

[0013] According to this aspect, when the expandable member expands, the membrane member prevents the expandable member from entering the gaps in the filter member, thereby preventing a decrease in the water conductivity of the filter member.

[0014] In order to solve the above problem, one aspect of the present invention is a method for installing a drainage pipe (1, 41) in the ground using the water-conducting section-forming member of the above aspect, comprising the steps of: placing a tubular section (2) having a hole (2a) in the ground; inserting the water-conducting section-forming member (30, 43) having an outer diameter smaller than the inner diameter of the tubular section (2) into the tubular section (2); and supplying water to the water-conducting section-forming member (30, 43) to expand the expandable member (31).

[0015] According to this aspect, the outer diameter of the water-conducting-section-forming member is smaller than the inner diameter of the tubular portion, which makes it easier to insert the water-conducting-section-forming member into the tubular portion. Furthermore, after the water-conducting-section-forming member is inserted into the tubular portion, the expandable member expands with water, thereby filling the gap between the inner circumferential surface of the tubular portion and the outer circumferential surface of the filter member. This prevents soil from entering the drainage pipe and reduces the impact of construction on the environment around the construction site. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a water guide section forming member for a drainage pipe and a drainage pipe installation method that is easy to insert into a tubular section and does not create a gap between the inner surface of the tubular section and the outer surface of the filter member. [Brief explanation of the drawings]

[0017] [Figure 1] 1A and 1B are side views showing a drainage pipe and its components according to the first embodiment (A: elongated member, B: spiral member, C: drainage pipe). [Figure 2] 1A and 1B are diagrams illustrating a cross section perpendicular to the extension direction of the drainage pipe according to the first embodiment, and explaining the formation process of the drainage pipe (A: before expansion, B: during expansion, C: after expansion). [Figure 3] 1A and 1B are diagrams showing a head protector for installing a drainage pipe according to the first embodiment (A: view from the front, B: view from the rear, C: cross-sectional view taken along the line CC in FIG. A); [Figure 4] 1A and 1B are diagrams showing a support pipe for installing a drainage pipe according to the first embodiment (FIG. 1A is a view from the front, and FIG. 1B is a front view). [Figure 5] 1 is a diagram showing a procedure for installing a drainage pipe according to the first embodiment; [Figure 6] 10A and 10B are diagrams illustrating a cross section perpendicular to the extension direction of the drainage pipe according to the second embodiment, and explaining the formation process of the drainage pipe (A: before expansion, B: during expansion, C: after expansion). DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a drainage pipe 1 and its constituent members according to a first embodiment. The drainage pipe 1 is buried in ground having a slope such as a slope, and drains water that has seeped into the ground. As shown in FIG. 1(C), the drainage pipe 1 has a tubular portion 2 and a water-conducting portion 3 filled in the tubular portion 2. The tubular portion 2 has a plurality of elongated members 4 arranged parallel to each other, as shown in FIG. 1(A), and a spiral member 5, as shown in FIG. 1(B).

[0019] The long material 4 is a steel material that extends straight and is corrosion-resistant. A plurality of long materials 4 arranged parallel to one another are arranged at intervals on the circumference when viewed from the direction of extension. For example, round steel bars with a diameter of about 3 mm may be used as the long materials 4, and 12 long materials 4 may be arranged at equal intervals on the circumference.

[0020] The helical member 5 is a member formed by winding a long steel material in a helical shape around an axis parallel to the extension direction of the long material 4, and is corrosion-resistant. Adjacent portions of the helical member 5 in the axial direction are spaced apart from each other. The helical member 5 has a circumferential shape with a predetermined diameter when viewed from the axial direction. For example, the helical member 5 may be formed by winding a rectangular long steel material measuring 2 mm in length and 3 mm in width in a helical shape at a pitch of 10.2 mm so as to have an outer diameter of 44 mm and an inner diameter of 38 mm.

[0021] As shown in FIG. 1(C), the cylindrical portion 2 has a grid-like structure, and is formed by fixing the elongated material 4 to the outer periphery of the helical member 5 by welding or the like. Because of the grid-like structure, the holes 2a formed in the cylindrical portion 2 are large and numerous. This increases the probability that the holes 2a in the cylindrical portion 2 will come into contact with the water passageway, making the holes 2a less likely to become clogged and improving drainage. Furthermore, because the elongated material 4 and the helical member 5 are made of steel, they have high strength. Furthermore, the angle that the cross section of the helical member 5 forms with respect to the elongated material 4 is not limited, making it relatively easy to manufacture the cylindrical portion 2.

[0022] As shown in FIG. 2(C), the water conducting section 3 is a member having voids that allow water to pass through but prevent sediment and the like from passing through. The water conducting section 3 is formed by expanding the water conducting section-forming member 30 shown in FIG. 2(A) in the radial direction of the drainage pipe 1. The water conducting section-forming member 30 includes an expandable member 31 that extends in the extension direction of the drainage pipe 1 and is expandable in the radial direction of the drainage pipe 1, and a filter member 32 that extends in the extension direction of the drainage pipe 1, covers the entire outer peripheral surface of the expandable member 31, has voids that allow water to pass through but prevent sediment from passing through, and is extensible in the circumferential direction of the drainage pipe 1. The outer diameter of the water conducting section-forming member 30 is smaller than the inner diameter of the tubular section 2. The water conducting section-forming member 30 may further include a membrane member 33 that is expandable in diameter and permeable to water, and is disposed between the expandable member 31 and the filter member 32 so as to cover the entire outer peripheral surface of the expandable member 31. The water guide portion forming member 30 preferably has an extension length equal to the extension length of the tubular portion 2, and the expandable member 31, the filter member 32 and the membrane member 33 preferably have extension lengths equal to each other.

[0023] The expandable member 31 includes a polymer absorbent material that expands by absorbing water. For example, a material (such as polyacrylate) used as an absorbent body in absorbent articles such as diapers may be used as the polymer absorbent material. The expandable member 31 has a circular cross section perpendicular to its extension direction.

[0024] The filter member 32 contains a material that prevents the inflow of soil and sand and allows rainwater that has infiltrated into the ground to pass through. For example, a three-dimensional plastic mesh molded product such as Hechimaron (registered trademark) manufactured by Shinko Nylon Co., Ltd. can be used as the filter member 32. The cross section of the filter member 32 perpendicular to its extension direction has a circular ring shape.

[0025] The membrane member 33 contains a material that is impermeable to the constituent materials of the filter member 32, such as a polymer absorbent material, but is permeable to water. The membrane member 33 may expand in diameter by the stretchability of the membrane member 33 material itself, or by unfolding the pleated folded portions. For example, a woven fabric or a nonwoven fabric can be used as the membrane member 33. The membrane member 33 abuts against the inflatable member 31 and the filter member 32.

[0026] As shown in Figure 2(A), after inserting the water-conducting-section-forming member 30 into the tubular section 2, water is supplied to the water-conducting-section-forming member 30. As shown in Figures 2(B) and (C), the expandable member 31 expands radially due to the water (indicated by the arrow in Figure 2(B)), causing the membrane member 33 and filter member 32 to stretch circumferentially and expand in diameter. When the expandable member 31 expands until there is no gap between the outer circumferential surface of the filter member 32 and the inner circumferential surface of the tubular section 2, the water-conducting-section-forming member 30 becomes the water-conducting section 3. The water may be supplied by an operator or may be soil water.

[0027] To insert the drainage pipe 1 into the ground, holes are drilled in the ground. If the ground remains self-supporting even after drilling, a hole of the required length is drilled and the drainage pipe 1 is inserted into the hole. An example of drilling means for cases where the ground is not self-supporting is explained below. Figures 3 and 4 show the tools used for drilling, and Figure 5 shows the drilling procedure.

[0028] FIG. 3 shows an annular head protector 9 having a bit 8 on its front surface, and FIG. 4 shows a cylindrical support pipe 10 to which the head protector 9 is attached at its front end. The peripheral wall of the support pipe 10 is closed without any holes, and is open at the front and rear. The peripheral wall of the support pipe 10 has projections and recesses on its front end, and the projections 11 of the projections 11 protrude into grooves 12 on the rear surface of the head protector 9. Because the projections 11 are engaged with the surfaces that define the grooves 12, rotating the support pipe 10 in the circumferential direction also rotates the head protector 9. Furthermore, when the support pipe 10 is advanced, the head protector 9 also advances, but when the support pipe 10 is retracted, the projections 11 come out of the grooves 12, and the head protector 9 separates from the support pipe 10. The outer diameter of the support pipe 10 is smaller than the inner diameter of the tubular portion 2, and the outer diameter of the head protector 9 is larger than the outer diameter of the tubular portion 2. Therefore, when the support pipe 10 is disposed inside the tubular portion 2 and the head protector 9 is attached to the front end side of the support pipe 10, the tubular portion 2 is disposed so as to be aligned with the head protector 9 in the front-rear direction.

[0029] 5(A) shows the initial state of the drilling cycle. The front end of the support pipe 10, to which the head protector 9 is attached, is inserted into the ground, and the support pipe 10 is positioned inside the tubular portion 2.

[0030] The support pipe 10 is rotated in the circumferential direction, and the bit 8 excavates the ground in a circular pattern while the head protector 9 and support pipe 10 are advanced approximately 300 to 500 mm (Fig. 5(B)). At this time, the tubular section 2 does not move, and soil and sand from the ground penetrates the front end of the support pipe 10. The tubular section 2 is then advanced until its front end abuts the rear surface of the head protector 9 (Fig. 5(C)). Next, the soil and sand that has penetrated the front end of the support pipe 10 is water-drilled using a rock drill 13 (Fig. 5(D)). At this time, since there are no holes in the peripheral wall of the support pipe 10, the water discharged from the rock drill 13 is not discharged outside the support pipe 10 and does not loosen the ground around the installation location of the drainage pipe 1. The slimy soil and sand are discharged, and the rock drill 13 is retreated (Fig. 5(E)). The above cycle is repeated to drill the ground.

[0031] Once the hole has been drilled to the desired depth, the support pipe 10 is rotated slightly in the opposite circumferential direction and retracted. This causes the head protector 9 to separate from the support pipe 10, leaving the head protector 9 and the cylindrical portion 2 in the hole. The head protector 9 is left in place in the hole.

[0032] 2, an operator inserts the water-conducting-part-forming member 30 into the tubular part 2 and supplies water to the water-conducting-part-forming member 30 to expand the expandable member 31, thereby bringing the outer circumferential surface of the filter member 32 into contact with the inner circumferential surface of the tubular part 2. Water may be supplied from a hose (not shown) or the like inserted into the gap between the tubular part 2 and the water-conducting-part-forming member 30, or soil water passing through the holes 2a of the tubular part 2 may be used.

[0033] The effects of the first embodiment will be described.

[0034] Because the outer diameter of the water guide part forming member 30 is smaller than the inner diameter of the tubular portion 2, the water guide part forming member 30 can be easily inserted into the tubular portion 2. In addition, in the completed state, the outer peripheral surface of the filter member 32 abuts against the inner peripheral surface of the tubular portion 2, which makes it possible to prevent soil and sand from flowing into the tubular portion 2.

[0035] Since the membrane member 33 is located between the expandable member 31 and the filter member 32, when the expandable member 31 expands, the expandable member 31 is prevented from penetrating into the voids in the filter member 32, thereby preventing a decrease in the porosity of the filter member 32.

[0036] Because the expandable member 31 can be expanded by water, it can be expanded without polluting the surrounding environment at the construction site. Furthermore, even if the drainage pipe 1 is installed with the expandable member 31 not fully expanded, the expandable member 31 will expand due to rainwater that has entered the tubular portion 2, thereby closing the gap between the inner circumferential surface of the tubular portion 2 and the outer circumferential surface of the filter member 32.

[0037] Next, a second embodiment of the present invention will be described with reference to Fig. 6. In the description, the components common to the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.

[0038] The drainage pipe 41 according to the second embodiment comprises a tubular portion 2 and a water conducting portion 42 filled within the tubular portion 2. The water conducting portion 42 is a member having voids that allow water to pass through but do not allow sediment and the like to pass through. The water conducting portion 42 is formed by the radial expansion of a water conducting portion-forming member 43 shown in FIG. 6(A) in the drainage pipe 41. The water conducting portion-forming member 43 comprises an expandable member 31, a filter member 32, and a core material 44 embedded in the expandable member 31. The water conducting portion-forming member 43 may further comprise a membrane member 33.

[0039] The core material 44 is less susceptible to bending deformation than the expandable member 31, the filter member 32, and the membrane member 33. The core material 44 is preferably disposed at the center of the expandable member 31 in the radial direction. The core material 44 is preferably present over the entire length of the water guide portion-forming member 43 in the extension direction, but multiple core materials 44 may be provided so as to be spaced apart from each other in the extension direction of the water guide portion-forming member 43. For example, a steel or resin pipe or rod may be used as the core material 44.

[0040] The presence of the core material 44 makes it difficult for the water guide part forming member 43 to bend, and therefore the water guide part forming member 43 can be easily inserted into the tubular part 2 .

[0041] Although the specific embodiments have been described above, the present invention is not limited to the above embodiments and can be widely modified and implemented. The cylindrical portion may be a steel or plastic pipe with holes in its peripheral wall. When installing a drainage pipe in a newly constructed embankment, the drainage pipe or cylindrical portion may be placed on the surface of the embankment in the process of being formed, rather than inserting the cylindrical portion after drilling the ground. The expandable member may contain a substance that expands by chemically reacting with a predetermined substance, instead of or in addition to a polymer absorbent material. [Explanation of symbols]

[0042] 1,41:Drainage pipe 2:Cylinder part 3,42: Water conveyance section 30, 43: Water conveyance section forming member 31: Expandable member 32: Filter material 33:Membrane member 44: Core material

Claims

1. A water conveyance portion forming member for a drainage pipe buried in the ground, an expandable member extending in a predetermined direction, having an outer circumferential surface, and including a polymer absorbent material that can absorb water and expand in a radial direction perpendicular to the predetermined direction; a filter member that is a three-dimensional plastic net-like molded product that extends in the predetermined direction, covers the outer peripheral surface of the expandable member, has voids through which water can pass, and is extensible in the circumferential direction; a membrane member that is disposed between the outer peripheral surface of the expandable member and the filter member so as to cover the expandable member in the circumferential direction, the membrane member expanding in diameter as the expandable member expands, and the water-permeable membrane member; A water guide portion forming member comprising:

2. The water guide portion-forming member according to claim 1 , further comprising a core material extending in the predetermined direction and embedded within the expandable member.

3. A method for installing a drainage pipe in the ground using the water guide portion-forming member according to claim 1 or 2, placing a cylindrical portion having a hole in the ground; inserting the water guide portion forming member, which has an outer diameter smaller than an inner diameter of the cylindrical portion, into the cylindrical portion; supplying water to the water guide portion forming member to expand the expandable member of the water guide portion forming member; A method for providing

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