JPH0734039U - Underdrain drainage pipe - Google Patents

Abstract

(57) [Summary] [Purpose] By installing in place of crushed stones, etc., on the retaining walls of various retaining walls, the permeated water is eliminated and the moisture content of the soil on the back is reduced, fluidization is prevented and the retaining walls are stabilized, and slopes The purpose is to provide an underdrain drainage pipe that has the effect of preventing collapse and erosion of the river. [Constitution] The permeated water is introduced into the partial back-split underdrain drainage pipe by means of a plate filter and drained.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This plan relates to underdrain pipes buried in cultivated land in order to drain excess groundwater and infiltrated water from agricultural fields such as paddy fields and upland fields to maintain proper soil water content and to promote healthy growth of crops. More specifically, it relates to an underdrain drainage pipe with an attached filter inserted on both sides.

[0002]

[Prior art]

 Conventionally, this kind of thing is as follows. Conventionally, various drainage conduits have been buried underground in cultivated land in order to remove excess water from the soil in agricultural land. Looking at it by material, in addition to unglazed clay pipes, synthetic resin pipes, bamboo pipes, etc., it is not a pipe, but there are many types, such as a rough culvert culvert, a rice husk culvert, a bundle of rice straw and straw, which are continuously buried. .

[0003] The underdrain using plants has a long shelf life because it is heavily corroded by bacteria in the soil. In addition, synthetic resin products have the highest corrosion resistance and rigidity, so they are most used. Most of them are used as perforated pipes by making circular or elongated cuts in the pipe body, This causes the inflow of soil particles, which accumulates in the pipes, impedes the flow of water, and significantly reduces the effect.When laying the soil particles, it acts as a filter around the pipe body and acts as a filter, In order to prevent the invasion of rice husks, it is usual to put rice husks, gravel, sand, etc. in the surroundings, or wrap a synthetic fiber woven or non-woven fabric around the pipe.

[0004]

[Problems to be solved by the device]

 The conventional techniques described above have the following problems. In recent years, it has become difficult to obtain rice husks, etc., and cloth and non-woven fabrics are often clogged, and the long-term effects cannot be expected. Furthermore, the unglazed clay pipe cannot fulfill its purpose as an effective facility because of large subsidence and damage due to the enlargement of agricultural machinery, and it is difficult to take measures against it, and it is desired to develop effective means. As described in the prior art, the non-woven fabric or woven fabric that is wound around the pipe and acts as a filter for suppressing the soil particles flowing in from the perforated part of the pipe is effective in the initial stage, After a couple of years, it causes clogging and partially causes water pollution on the ground surface.

When the cause is examined, in the case of woven cloth, since the folds intersect at regular positions and the thickness of the thread is also constant, the creases caused by the intersections are almost constant along with the regular arrangement. The size will be configured. For this reason, soil particles entrained by groundwater and seepage water from the surface show extremely irregular shapes and complicated movements due to the amount of seepage water. An impermeable layer is formed around the pipe due to the reappearance of the tube. In addition, the non-woven fabric filter has irregular fiber intersections and good water permeability, but due to the thickness of the filter, if the amount of permeated water is small, soil particles will accumulate in the filter layer, resulting in As a result, a part or a considerable part of the filter often transforms into an impermeable layer and loses the underdrain effect.

The present application has been made in view of such problems of the conventional technology, and an object of the present application is to provide the following. The present invention intends to change the shape and function of the filter having the above-mentioned problems, which is the conventional technique, to directly insert the permeated water into the pipe from the upper part of the underdrain pipe, and to drain the permeated water. is there.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is as follows. That is, the one of the present application is composed of a plate-shaped filter 2 and a partial back culvert drainage pipe 3, and the plate-shaped filter 2 is a substrate 2A and one and the other of which are stretched on the front and back surfaces of this substrate 2A. The substrate 2A is composed of sheet filters 2B and 2C. The substrate 2A is embossed with frustoconical protrusions 2A2 and 2A3 of a required height toward the front and back of a smooth substrate body 2A1 made of synthetic resin. The heads of the frusto-conical protrusions 2A2 on the front side and the heads of the frusto-conical protrusions 2A3 on the back side of the substrate 2A are molded so as to be arranged regularly at regular intervals. The sheet filters 2B and 2C are adhered to each other, and the plate filter 2 is cut into a rectangular shape of a predetermined size so that the sheet filter 2 can be mounted on the partial back culvert drainage pipe 3. On the other hand, the partial back culvert drainage drainage is performed. Tube 3 is vinyl chloride resin On the back of an ordinary non-perforated tube 3A such as an Ip or the like, a back split portion 3B is engraved so that the plate filter can be vertically inserted into the longitudinal direction of the non-perforated tube, and a non-back split portion that is not engraved. 3C and 3C are formed alternately, and further, in the back split portion 3B of the partial back split drainage pipe 3, a pipe insertion portion below the plate-shaped filter 2 is inserted into the drain pipe.

In this case, the sheet-like filters 2B and 2C are obtained by spreading fibers of several kinds of thickness into a non-woven fabric and rolling them with heat treatment, and the intersections of the fibers are fused. It can be configured so as not to peel off. Further, in the sheet filters 2B and 2C, the upper end surfaces 2B12 and 2C12 and the end surfaces 2B13 and 2C13 on both sides are closed by heat treatment, and only the lower end surfaces 2B11 and 2C11 of the sheet filter can be opened. it can. Further, the back split portion 3B can be configured to have a length of about 30 cm to 60 cm, and the non-back split portion 3C can be configured to have a length of about 5 cm to 10 cm.

[0009]

【Example】

 Examples will be described with reference to the drawings. 1 is the underdrain drainage pipe of the present invention, which is composed of a plate-like filter 2 and a partial back splitting underdrain drainage pipe 3. Therefore, the plate-shaped filter 2 is composed of a substrate 2A and one and the other sheet-shaped filters 2B and 2C stretched on the front and back surfaces of the substrate 2A. Substrate 2A is made of smooth synthetic resin main body 2A1 so that frustoconical projections 2A2 and 2A3 of required height are regularly arranged in an embossed structure in the front and back directions. It is molded. The sheet-shaped filters 2B and 2C are respectively provided on the head of the truncated cone-shaped protrusion 2A2 in the front direction and the head of the truncated cone-shaped protrusion 2A3 in the back direction of the substrate 2A. Are glued together.

The sheet-shaped filters 2B and 2C are formed by forming fibers of several kinds of thickness into a non-woven fabric and expanding them with a roll while heat-treating, and the intersections of the fibers are completely fused. It does not peel off. Further, in the sheet filters 2B and 2C, the upper end surfaces 2B12 and 2C12 and both end surfaces 2B13 and 2C13 are closed by heat treatment, and only the lower end surfaces 2B11 and 2C11 of the sheet filter are opened. This is to prevent soil particles from entering the inside of the plate filter during and after the burial. The pores of the sheet-shaped filter molded in this way are 0.2 to 1.5 mm, and particles of unspecified size in natural soil can be suppressed. The plate-shaped filter 2 molded in this manner is cut into a rectangular shape of a predetermined size so that it can be mounted on the partial back-split underdrain drainage pipe 3.

Therefore, the partial back-split underdrain drainage pipe 3 is arranged so that the plate filter can be vertically inserted in the pipe in the longitudinal direction of the non-perforated pipe at the back of the ordinary non-perforated pipe 3A such as a vinyl chloride resin pipe. Back-splitting portions 3B engraved on the back and non-back-splitting portions 3C not engraved are alternately formed. In this case, the length of the back split portion 3B is preferably about 30 cm to 60 cm, and the length of the non-back split portion 3C is preferably about 5 cm to 10 cm. In this way, the meaning of alternately processing the back-splitting part and the non-split-splitting part is that when the partial back-split culvert drainage pipe 3 is stretched and buried, cracks open or overlap inside, and the culvert pipe is It is to prevent it from failing to serve its purpose.

Further, a tubular body insertion portion 2D below the plate-shaped filter 2 is inserted in the back split portion 3B of the partial back split underdrain drainage pipe 3. The plate-shaped filter attached to the partial dorsal drainage pipe looks like a dorsal fin of a fish. The partial backspout drainage pipe manufactured in this way extends over the side of the trench previously excavated for burial on the cultivated land where the underdrain should be installed, and the plate filter of the size shown in the design is used. After inserting the drainage pipe for the part of the back split into the groove bottom, correct the position and twist, and perform backfilling to complete the process. 4 is backfill soil.

According to the conventional technique, a method of wrapping or wrapping a filter sheet around a perforated pipe and covering it with high quality masa soil or sand for about 10 cm, and then using excavated soil to backfill it, A method was used in which rice husks were put in the vicinity of a perforated pipe and then the soil was backfilled with excavated soil, but the former had problems such as clogging and the latter being corroded. However, in the present invention, since the sheet filter itself has a thick internal space and has a kind of pipe line structure, it not only has a good water collecting and absorbing function, but is also vertically inserted into the pipe and drained. The function is also very good. Also, when backfilling, excavated soil can be directly converted to backfill soil unless it is heavy clay, which is not only economical but also useful for shortening the construction period.

Further, since the plate-shaped filter 2 has an embossed structure having a truncated cone-shaped protrusion on both sides of the substrate, it has excellent pressure resistance and a strain rate of about 30% under a load of 50 tons per m ^2. It was degree. The experiment was carried out for the purpose of stabilizing the retaining wall by eliminating the permeated water on the back side of the retaining wall in the agricultural road retaining wall construction. The site is a farm road that cuts the slope on the mountain side and leads to other villages through a good plateau.The cut surface is volcanic ash mixed with boulders. Is an expected place. The gravity-type concrete retaining wall stood up as designed, before the concrete hardened and the back surface was backfilled, the one of the present invention was installed.

First, on the front wall of the retaining wall, a partial back culvert drainage pipe was connected to the extension of the retaining wall using a joint. In this case, what is important is to connect the back splits so that they are in a straight line. Also, use a T-shaped tube in accordance with the position of the drain hole provided to drain the water outside the retaining wall. It is connected so that it can be inserted. In this case, the back split underdrain drainage pipe 3 has a diameter of 10 cm, a back split portion has a length of 60 cm, and a non-split portion is 60 cm. The split split portion 3B and the non-split portion are provided over the entire length of the pipe. The beginning and the end are closed by attaching a cap.

After inserting the plate filter having a width of 60 cm, a height of 60 cm and a thickness of 9 mm into the back split portion of the partial back split underdrain drainage pipe 3 extended in this way, the whole is penetrated to the bottom of the wall body. Insert the T-shaped pipe attached to the partial back culvert drainage pipe 3 into the opened drainage holes (every 1 m interval), and quietly hold the excavated soil so that the plate filter already attached is upright as much as possible. It was backfilled little by little, and when it was almost covered up, it was backfilled rapidly by machine or human power.

Thus, one month after the completion of construction, there was rainfall of 85 mm / day near the site, but the amount of water that was clearly visible was continuously drained from each drain hole about two hours after the start of rainfall. After the rain stopped, the drainage condition continued for about 6 hours, indicating a functionally good condition. The sediment on the back of the retaining wall was stable. The permeability of the plate-shaped filter, which is a component of the present invention, is difficult to be defined because it has a complicated shape, but it is approximately 8 × 10 '(cm / sec). The result of measuring the roughness coefficient was 0.09.

The operation will be described together with the effect.

[0019]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. The present invention is configured as described above, and by installing it in place of the back-filling stones of various retaining walls, the permeated water is eliminated, the moisture content of the backside sediment is reduced, fluidization is prevented, and the retaining walls are It stabilizes and prevents slope collapse and erosion. In addition, when the device of the present invention was used for drainage from the underdrain for upland fields and paddy fields, the groundwater level decreased, and due to the improvement in overhumidity, the ground temperature rose about 1.2 degrees in the upland field. 15% for vegetables and 10% for vegetables, both increased compared to the normal crop. Furthermore, it was confirmed that the division was promoted in paddy rice.

Further, in the case of ordinary underdrain drainage, the present invention prevents the inflow of soil particles from the effective portion when burying the underdrain pipe, or a large amount of coating to prevent clogging of wound non-woven fabric etc. Although timber (husks, cut gravel, etc.) is required, it is difficult to collect rice husks due to changes in harvesting and threshing methods, and cut gravel, etc. are restricted in collection, remote production areas and concrete bones. It is difficult to carry into the site due to competition with materials, deterioration of traffic conditions, weight restrictions, etc., and the price is soaring that the economy is being lost.On the other hand, the product of the present invention is lightweight and easy to handle. , A stable supply and quality can be secured with factory products, it does not corrode like rice husks, and ordinary excavated soil can be used as backfill soil unless it is a heavy clay-based backfill soil. Since there is no It can be shortened and the economic effect is great.

[Brief description of drawings]

FIG. 1 is a perspective view in which a part of a plate-shaped filter portion is cut away.

FIG. 2 is a plan view in which a part of a substrate portion is omitted.

FIG. 3 is an enlarged cross-sectional view of a main part of a plate filter.

FIG. 4 is an enlarged front view of a main part of the present application with a part cut away.

FIG. 5 is an enlarged sectional view taken along line AA.

FIG. 6 is a vertical cross-sectional view of the case where the present invention is used in an agricultural land or the like that requires underdrain drainage.

FIG. 7 is a schematic perspective view of a sheet filter.

[Explanation of symbols]

 1 Underdrain drainage pipe 2 Plate filter 3 Partial back splitting underdrain drainage pipe 4 Backfill soil

Claims (4)

[Scope of utility model registration request] 1. A plate-shaped filter (2) and a partial back-split underdrain drainage pipe (3), wherein the plate-shaped filter (2) comprises:
It is composed of a substrate (2A) and one and the other sheet filters (2B, 2C) stretched on the front and back surfaces of the substrate (2A). The substrate (2A) is a smooth substrate body made of synthetic resin ( 2A1) are shaped so that the frustoconical ridges (2A2, 2A3) of the required height in the front and back directions are embossed so that they are regularly arranged at appropriate intervals. Frusto-conical projection (2A
2) head and a frusto-conical protrusion in the back direction (2A3)
Sheet-shaped filters (2B, 2C) are adhered to the head of the plate-shaped filter (2), respectively.
Is cut into a square of a predetermined size so that it can be attached to the partial back split underdrain drainage pipe (3), while the partial back split underdrain drainage pipe (3) is cut.
Is an ordinary non-perforated pipe such as vinyl chloride resin pipe (3
A back split portion (3B) carved so that the plate filter can be inserted vertically into the pipe in the longitudinal direction of the non-perforated pipe and a non-back split portion (3C) not carved are alternately arranged on the back of A). Formed and further partially split drainage pipe (3)
An underdrain drainage pipe, characterized in that a tubular body insertion portion below the plate-shaped filter (2) is inserted into the back split portion (3B). 2. The sheet-like filter (2B, 2C) is
The non-woven fabric made of fibers of several kinds of thickness is expanded by a roll while being heat-treated, and the intersections of the fibers are fused so that they are not separated from each other. Underdrain drainage pipe. 3. The sheet filter (2B, 2C) is
Upper end faces (2B12, 2C12) and both end faces (2B1)
3, 2C13) are closed by heat treatment, and the lower end faces (2B11, 2C1) of the sheet-like filter are closed.
The underdrain drainage pipe according to claim 1 or 2, wherein only 1) is opened. 4. The back split portion (3B) has a length of about 30 cm to 60 cm, and the non-back split portion (3C) has a length of 5.
The underdrain drainage pipe according to claim 1, wherein the drainage pipe is about 10 cm to 10 cm.