JPS62228515A - Draining material - Google Patents

Abstract

PURPOSE:To keep a draining characteristic for long periods by using a draining material made of a composite consisting of a plastic sheet having through holes in the tops of its cross section where hollow recessions and projections are alternately continued and a hydrophilic cloth. CONSTITUTION:A draining material is made of a composite material formed by covering a hydrophilic cloth 6 on a perforated uneven sheet 1, where the cloth 6 is bonded at a joint portion 7. For the sheet 1, the shape, positional form, and dimensions of the projection are freely selected, cavities 5 and 5' and tops 2 and 2' are formed, and through holes 4 and 4' are formed to connect the surface and back sides. By setting the holes 4 and 4', the cross-sectional area of the upper and lower cavities 5 and 5' can effectively be used as water paths. A draining material having high pressure resistance and filtering characteristics and also having good draining characteristics for long periods can be obtained.

Description

[Detailed description of the invention] [Industrial use bone! 'F) The present invention relates to a drainage material for civil engineering and construction. More specifically, the present invention relates to a drainage material for discharging soil water, rainwater, etc.

[Conventional technology]

Currently, various drainage methods have been proposed as ground improvement methods. One of the known methods is the ground consolidation drainage promotion method. This method involves installing sand drains using sand in both vertical and horizontal directions. & This method speeds up the dissipation of ground water by carrying out embankment and draining the excess pore water generated in the soft ground due to the overburden load in the vertical direction. In recent years, this construction method has had problems such as the difficulty and high cost of obtaining high-quality sand, pollution problems caused by noise and dust during transportation, cutting of drains due to uneven settlement, and the labor-intensive construction process.

In order to solve these problems, prefabricated drains using nonwoven fabric, plastic, etc. as materials to replace sand have been proposed. In particular, as a result of extensive research into vertical prefabricated drains, prefabricated drains are being put into practical use despite some problems. However, for horizontal use, the required characteristics as a drainage material are: 1) Good water permeability (in the surface direction and perpendicular angle direction) 2) No clogging, 3) Elongation in the surface direction is small, 4)
It is still insufficient to have little deformation in the direction perpendicular to the surface, 5) durability, and 6) good handling properties.

That is, the nonwoven fabric materials that are generally offered as prefabricated drains are generally needle bunched nonwoven fabrics, but wood materials have low strength and high elongation, causing large deformation, which poses a practical problem. Furthermore, since the thickness changes greatly with respect to earth pressure, the porosity of the nonwoven fabric decreases significantly, and the water permeability in the plane direction and the direction perpendicular to the plane significantly decreases. Moreover, since the water wettability is not sufficient, the water permeability is further reduced. Furthermore, since the nonwoven fabric has a coarse mesh, clogging due to accumulation of soil particles inside the nonwoven fabric is promoted, resulting in problems such as the nonwoven fabric not being able to withstand long-term use.

In order to improve these problems, a new drainage material has been proposed in which a textured plastic core material is coated with a filter. Although this drainage material is intended to improve the drainage layer and its strength due to large voids, there are problems with the core material structure and the filter material structure, and it cannot be said to be sufficient for practical use.

In other words, if the core material has a wavy shape,
Water only flows in one direction, and when it is blocked by dirt or filters, there is a problem of poor drainage. or,
There is also the problem that it is not flexible and difficult to handle.

In addition, when the shape is uneven with protrusions, water flows in multiple directions, but it is difficult to reduce the pitch of the unevenness, and the filter digs into the recessed part of the core material over the entire surface, lowering the water flow cross section and preventing drainage. Cause sexual defects. Even if the uneven pitch can be made small, the elongation of the filter material is large as compared to -i, so the water passage cross section is still lowered by biting into the recesses.

Furthermore, if the unevenness pitch is extremely small, the bending properties will deteriorate and handling will be poor. Therefore, a method has been adopted in which the height of the unevenness is increased relative to the pitch in the surface direction of the unevenness of the core material to increase the cross-sectional area of water passage (and to reduce the amount of water entering the concave portion of the core material. Elongation of the filter material is a problem, causing a reduction in the water flow cross-sectional area.Also, as the height of the unevenness increases, the pressure resistance of the core material decreases.Also, since these core materials are not connected to the front and back surfaces, The water flow cross section is halved.

Therefore, in order to improve water permeability, an improved core material in which the core material has holes has been proposed. However, because this core material is manufactured by molding a perforated sheet or a partially slit sheet into irregularities, the resulting perforated core material has irregular hole shapes, diameters, and arrangement, resulting in a decrease in strength and pressure resistance. Imitate (I have a problem.

Furthermore, there are many problems regarding the filter material coated on these core materials. That is, since most commonly used filter materials are needle bunched nonwoven fabrics, there is a problem in that required properties are not met, particularly in terms of strength, elongation, thickness change due to earth pressure, hydrophilicity, and clogging.

[Problem that the invention seeks to solve]

The present invention has been achieved as a result of extensive research to solve the above-mentioned problems.In other words, the purpose of the present invention is to solve the above-mentioned problems when buried underground as a drainage material for civil engineering and construction.
No damage to drainage characteristics over a long period of time, pressure resistance characteristics,
The present invention provides a drainage material with good filter properties.

[Means to solve the problem]

To solve the above problem, the drainage material according to the present invention has a sheet cross section in which hollow concave portions and convex portions are alternately continuous, and has a hydrophilic plastic sheet having a through hole at the apex of the concave portions and/or convex portions. It is characterized by being made of a composite material with fabric.

The aperture ratio of the M holes is 0.1 to 20 of the transparent area of the sheet.
% is preferred.

The compression history characteristic of the fabric C, the surface pressure during compression 5
kg/cm2 or surface pressure at the time of compression recovery 2 kg/
It is preferable that the change in the fiber filling degree of the fabric under cJ is 25% or less, and the amount of fabric is 1/2 or less of the sheet thickness of the fabric.

In addition, 1. The coverage rate of the fabric is the plastic sheet L,
' is preferably 95 to 5% IO.

・'Example] The present invention will be described in further detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing one embodiment of the drainage material of the present invention. In FIG. 1, the drainage material of the present invention is a perforated uneven sheet 1
It consists of a composite body coated with a hydrophilic fabric 6, and the fabric 6
are joined by a joining part 7. In this embodiment, the hydrophilic fabric 6 wraps the perforated uneven seam 1 from both sides.
The hydrophilic fabric 6 is covered with a perforated sheet 1.
-1 may be used only on one side or partially.

Also, a water-based material may be used on one side or in part.

When the drainage material of the present invention is used for horizontal drains, water is
As shown in FIG. 4, the fluid flows in the surface direction within the sheet 1 through the fabric 6 from the front or back surface or front and back surfaces.

FIG. 2 shows the top portions 2.2', 5. 2 is a cross-sectional view of the perforated uneven sheet 1 cut in the transverse direction along 1. FIG. 3 is a plan view of the perforated sheet 1. Figure 2,
As shown in FIG. 3, the perforated uneven sheet l has a cavity 5.5.
' and apex 2.2', that is, ix-head tt-shaped uneven parts are provided alternately on the front and back surfaces (when viewed from the front or back side, the projections are arranged in a houndstooth pattern) in the direction perpendicular to the surface. It gives a sense of sublimity, and the front and back sides are connected.')
Through holes 4 and 4' are provided. By increasing the elevation in the vertical direction of the surface, the volume of the cavity 5.5' is increased, and the amount of water flowing through the cavity is increased.

In addition, by installing the through holes 4, 4', the upper cavity F 5.
The cross-sectional area within 5' can be effectively used as a passageway.

Furthermore, by arranging the protrusions in a houndstooth pattern, water can flow in multiple directions. Additionally, flexibility can be imparted, which is effective in terms of water permeability and ease of handling.

Although some of this idea has been known in the past, the form, dimensions, and positional relationships of protrusions and holes have not been sufficiently studied, and in the conventional technology, pressure resistance characteristics and water permeability characteristics have not been sufficiently studied. It wasn't satisfying.

In the present invention, in this perforated uneven sheet I, there are no particular limitations on the shape, arrangement, size, etc. of the projections, or the shape, arrangement, size, etc. of the holes.

For example, the protrusion shape may be a truncated cone, an elliptical truncated cone, a polygonal truncated cone, etc.
Further, the top portion 2.2' is not limited to the flat surface shown in the drawings, but may have a curved surface, an angular surface, or the like. Furthermore, the arrangement form, dimensions, etc. of the protrusions can be freely selected. In addition, the shape of the through-hole may be circular, oval, polygonal, or irregularly shaped, singly or in combination, and the hole size, hole device, number of holes, etc. can be freely selected, but there are It is necessary to fully consider the later pressure resistance characteristics and water permeability characteristics when designing. In this case, the protrusion,
Rising angle of side part 3 of striking convex part, tanθ=H/a
(See FIG. 2), it is preferable that θ=55 to 85″. When θ<55″, the pressure resistance property deteriorates, and when θ>85′, the pressure resistance property and moldability deteriorate. In addition, the height I4 of the unevenness is set by calculating the cross-sectional area from the required water flow rate, but 1 I = 5
~b A sufficient water cross section cannot be obtained, and furthermore, the fabric digs into the recesses, causing a reduction in the water flow cross section.

If H>5On+m, the handleability and pressure resistance will be poor.

Also, the width L of the concave portion of the sheet i (see Figure 2) is the height of the concavity and convexity! ■, rising angle θ of side part 3 and length b of top part 2.2'
Although it is determined based on the dimensional relationship between

That is, if the recess width (7) is made large even though the fabric has no rigidity and is highly elongated, the fabric will dig into the sheet recess under pressure, causing a reduction in the cross-sectional area of water passage. These relationships are preferably designed with reference to the membrane material theoretical formula (the formula below). The width of the recess is at least 5 to 30 mm. If L is 51, it is difficult to manufacture, and if L > 30 mm, the fabric will be too flexible.

δ: Deflection amount of the fabric (m) ω: Positive pressure kg/m) L: Width of the recessed part of the sheet (m) Et: Tensile stiffness of the fabric (kg/m) The pressure resistance characteristics of the textured sheet obtained by the above configuration are as follows:
It will be extremely expensive.

The through holes 4.4' are provided regularly or irregularly at the top 2.2' of the protrusion from the standpoint of pressure resistance and manufacturing. Top 2
．． Installing holes other than 2' will severely deteriorate the pressure resistance. This is because the concavo-convex molded product of the sheet 1 is extremely thin at the side part 3 with respect to the top part 2.2'. However, if the holes are extremely fine, they may be provided partially in areas other than the top 2.2', in addition to the through holes 4, 4' in the top 2.2'.

(2) The dimensions of the through holes 4, 4' are preferably 10 to 60% of the area of the top parts 2, 2', and are opened in the center.

If it is less than 10%, water flow is poor, and if it exceeds 60%,
Pressure resistance and manufacturing are issues.

Further, the through holes 4, 4' may be provided on the entire surfaces of the front and back apexes 2, 2', on the entire surface of the single-sided apex 2 or 2', or partially on those surfaces, but the aperture ratio sheet 1 The area ratio of the entire holes 4, 4' to the transparent area of 0.
It is preferable to set it to 1 to 20%. If O is less than 1%, sufficient water permeability will not be obtained, and if it exceeds 20%, pressure resistance will be extremely low.

The through holes 4, 4' are made circular by post-processing the uneven sheet.
It can be provided in an elliptical or polygonal shape.

In this way, the perforated uneven sheet 1 obtained has almost the same pressure resistance as a non-perforated product, and has extremely good water permeability.

Materials for the perforated uneven sheet 1 of the present invention include hard vinyl chloride, polystyrene, polyethylene, polypropylene,
Hard thermoplastic resins such as nylon, polyester, and ABS can be used, and the content is not particularly limited. The thickness of the sheet material used is preferably 0.1 to 31II11 from the viewpoint of strength and flexibility.

On the other hand, the fabric 6 used in the present invention is a hydrophilic fabric 6.
Hydrophobic fabrics that use water have extremely poor wettability with water, and surface tension prevents water from penetrating, causing air to become trapped inside the fabric, resulting in poor water permeability. Therefore, when using hydrophobic fiber materials, in advance at the yarn stage or fabric stage, higher fatty acid alkali salts, quaternary ammonium salts, polyethylene glycol alkyl ethers, higher amine halogenates, alkyl sulfonates, sulfosuccinates, etc. It is used after being treated with a surfactant such as a salt to make it hydrophilic.

Therefore, the fiber materials used are not limited to hydrophilic fibers and hydrophobic fibers (natural fibers such as cotton, hemp, sheep, wool, metals, glass, inorganic fibers such as carbon fibers, cellulose, protein fibers, etc.). Synthetic fibers such as polyamide, polyester, polyolefin, polyurethane, polystyrene, etc.
Polyvinyl chloride, polyvinylidene chloride, polyacrylic,
Synthetic fibers such as polyvinyl alcohol-based fibers can be used alone or in combination. Preferably, a durable raw fiber material such as synthetic mm is used to withstand long-term use.

In addition, these fibers include long fiber yarns, spun yarns, single fiber yarns, etc., and their shapes include regular circular cross-section yarns, irregular cross-section yarns, foamed yarns, conjugate yarns, etc., and there are no particular restrictions on their use. These fibers can be used alone or in combination, and they can also be used as processed yarns that have been physically or chemically processed.

The form of the fabric 6 used in the present invention is a woven fabric, a woven fabric, or a non-woven fabric made of the mentioned fiber threads, singly or in combination, and the form and content are not particularly limited in terms of use. .

For example, woven fabrics include plain weave, twill weave, satin weave, and special weave fabrics; knitted fabrics include flat knitting, circular knitting, warp knitting, and special knitting fabrics; and nonwoven fabrics include spunbond fabrics, There are dry woven fabrics using the needle punch method, wet non-woven fabrics using the papermaking method, and special fabrics such as Marimo and Mariwat.
Can be used in combination. In addition, these fabrics are subjected to physical processing such as napping treatment, press treatment, heat treatment, resin treatment,
Even if you use a material that has been treated with chemicals, etc., the filter effect can be selected accordingly. (Water permeates through, but the effect of particles'L'i i! Uha y odor 1.) ·,! In order to maintain it for a long time, the thickness of the olfactory thread of the fiber used for the fabric 6 is 0. A range of 1 to 10 de, - l is desirable.

If it is less than 0.1 denier, the fiber filling amount is high and the yuri-'
1< Although it is possible to prevent dirt and sand from commuting due to the density, the water permeability is extremely low), and the fabric strength is low and it will break.
'3 il, easy, If it exceeds 10 f, the amount of fiber filling is low, and although the water permeability is good because 1 go becomes a table, there is a lot of permeation of soil particles (inside the fabric and perforated unevenness). G) If L1 becomes clogged in the L1, it will function as a drainage material. , Furthermore, if the single yarn thickness is within the above range,
t) of a single denier may be used alone, or those of different deniers may be used in a mixed or laminated manner.

Further, it is desirable that the fiber filling amount of the fabric 6 is 10 to 509A.

If it is less than 10%, the porosity increases. , the direction is 1-, but the soil particles 1. (It becomes gargling, and clogging inside the 6j field and inside the perforated uneven sheet 1 occurs, and the function of the drainage material exceeds 782 = 50%. When filtering,
Soil grains - 1-0) Permeation is low f:<<8roga9, water permeability is extremely low.

Incidentally, the degree of miscellaneous filling here refers to the ratio of fiber volume to a constant volume of four strands, and is expressed by the F formula.

However ξ1. , α: Fibre-filling degree (%) e′: Fibre-filling juice, @(g,'cd)e? Woven fiber true specific gravity (g/"" (S・I) W: Nunobata weight effect L g ) V: Volume of fabric > Fiber filling degree composition is within the above range, t'1 ．． rt
The entire fabric is made with uniform density τ, or in the thickness direction,
It is also good to configure it with due south in the linear direction or in both directions.

In terms of filter efficiency, a true density configuration is preferable. This is because soil particles are prevented from permeating through dense areas of fiber filling.
This is because water permeability can be improved in sparse areas.

FIG. 5 is a model diagram showing an example of the above-mentioned fiber structure.

FIGS. 5(A) to 5(F) are longitudinal sectional views thereof, and FIG. 5(E) is a plan view of the fifth section (D). In FIG. 5, 6 is a fabric, 8 is a sparsely filled portion of fibers, and 9 is a dense portion thereof. FIG. 5(a) shows a structure in which fibers are dispersed sparsely and densely throughout the thickness and surface direction of the fabric.

Figures 5(b) and 5(c) show structures in which the fibers are made dense in the thickness direction along the surface of the fabric. FIG. 5(D) shows a structure in which the fiber density variation in thickness is increased at regular intervals in the surface direction, and FIG. 5(E) shows a plan view thereof. FIG. 5(f) shows a structure in which the fibers are made denser and denser along the surface in the thickness direction and partially in the surface direction. The true south structure of the fiber can be appropriately set by the fabric form, the thickness of the single fiber yarn, the degree of convergence of the single fiber yarn, physical processing, chemical processing, etc.

Furthermore, in the present invention, the degree of deformation of the fabric 6 due to surface pressure preferably satisfies the following conditions. That is, (1) the change in the amount of fiber filling under a surface pressure of 5 kg/cnr during compression is 25% or less; (2) the change in the amount of fiber filling is 25% or less under a surface pressure of 5 kg/cnr during compression; (3) If conditions (1) and (2) above are not satisfied,
The value under 2 kg/C1a according to the compression recovery curve satisfies the above conditions. This minimizes the deformation of the fabric 6 due to impact loads during construction, high pressure loads, or earth pressure after construction, and maintains the initially set filter effect (especially water permeability) of the fabric 6 and water permeability as a drainage material for a long period of time. This is to maintain it.

If the fabric deforms significantly, the water permeability of the fabric and the water permeability of the drainage material will decrease, and any deficiency in either will be undesirable from a practical standpoint.

FIG. 6 shows some characteristics of the fabric during a pressure cycle of 6M. In FIG. 6, the shaded area (A) is the area that satisfies the above conditions, that is, the fiber filling degree change is α
~1.25α, indicating a strain change range of 0 to %H.

■, ■, ■ and ■ lines in the figure are compression characteristics, ■1 and ■2
The line shows the history characteristics of the ■ line. In this figure, the ■ and ■ lines satisfy the above conditions (1) and (2) in terms of fiber filling degree and strain under a surface pressure of 5 kg/c. ■ and ■ in the diagram
Under a surface pressure of 5 kg/cIIt, the fiber filling degree and strain change significantly, so conditions (1) and (2) above are not satisfied, but under a surface pressure of 25 kg/cIIt, they recover to some extent and their The above conditions (
3) is satisfied. The two lines ■ and ■ in the figure correspond to the above condition (1).

Neither (2) nor (3) is satisfied.

Fabric structures that satisfy this condition include fabrics that have little deformation in the thickness direction and surface direction, that is, fabrics that have rigidity, such as fabrics using low elongation fibers, resin-treated fabrics, partially fused fabrics, and large denier fabrics. Although it is preferable to use a fabric such as a main fabric or a partially bundled fabric of single tL@fibers, the present invention is not particularly limited to these.

Regarding the distortion of the fabric, as described above, it is preferable to design the rigidity of the fabric 6 with reference to the membrane material theoretical formula in conjunction with the width of the recesses in the perforated uneven sheet 1.

It is practically preferable that the fabric has a basis weight of 30 to 500 g/m and a thickness of 0.1 to 31 g/m. Weight is 30g
If the thickness is less than /rd or the thickness is less than O, I ram, the amount of fibers will be extremely small, resulting in a weakened filter effect and a decrease in strength. The basis weight is 500g/n? or when the thickness exceeds 3 mm, the thickness becomes excessive, leading to a decrease in water permeability, and being heavy and bulky, resulting in poor handling.

The above-mentioned material may be made into a composite by using the perforated sheet 1 and the hydrophilic fabric 6 by an appropriate known method.

As described above, in FIG. 1, which shows an example of the drainage material of the present invention, a perforated, uneven plastic sheet 1 of a predetermined width is covered with a fabric 6, and the ends of the fabric 6 are joined at joints 7.

In the present invention, the coverage rate of the fabric 6 on the sheet 1 is 95≦PS105. P<95 is difficult to coat, and the finished product curls, causing problems in handling. When P>105, the margin of the fabric is too large, which causes the sheet to dig into the convex portions, resulting in a decrease in water permeability. With P<95, the sheet is likely to be wavy, resulting in poor shape and poor handling.

Further, the joint portion 7 of the fabric 6 is joined by adhesion, fusing, sewing, Velcro, or other anchoring joints, etc., singly or in combination. Preferably, a joining method such as sewing or adhesive bonding is desirable in terms of strength and quality. In this case, it is necessary to select a sewing style that causes fewer stitches to tangle during cutting, fewer needle holes, or an adhesive that has excellent water resistance. Note that the form of the joint portion 7 is not limited to that shown in the figure, and may be appropriately selected from the viewpoints of the joining method, performance, etc.

(Experimental Example) Next, a comparative test was conducted on the pressure deformation resistance and pressure drainage resistance characteristics of the drainage material according to the present invention and the drainage material according to the prior art, and the results are shown in graphs in FIGS. Evaluation was made in the lower column.

The clogging characteristics of the drainage material were evaluated using the fabric alone (lower column of Table 2) and are shown in FIG.

As a plastic sheet, hard vinyl chloride resin board 0.
A comparative example and an inventive example were prepared using a thickness of 5 mm and the dimensional configuration shown in Table 1. Examples of the present invention are shown in Figures 2 and 3.
It was a product with the same shape as the figure. On the other hand, fabrics having the configurations shown in Table 2 were created.

The above two materials were combined (the ends of the fabric were glued together) to form a drainage material having the same form as shown in FIG. 1. Combinations of plastic sheets and fabrics are shown in Table 3 using the example numbers in Tables 1 and 2.

Table 1 Table 2 * In the above table, Kariya is good, ○ is good, Table 3 * 1 Rin, Kariyo 2F Kyuko 0 Makiko, As shown in Figures 7 and 8, the comparative plastic sheet non-porous product ■ Although the used drainage material Nll showed little change in volume, its water permeability was extremely poor. In addition, the comparative drainage material 2 using the perforated plastic sheet product 2 was damaged under low pressure, and both volume change and water permeability were poor. Drainage material No. 3 using plastic sheet effective product (2) of the present invention had good volume change and water permeability.

As shown in Figures 7 and 8, drainage material N! uses fabric ■ for comparison! L4 is a drainage material 1 with large fabric deformation, significant volume change, and significant drop in water permeability, and comparative fabric ■.
'h5 has little volume change and water permeability change, but has poor water wettability and extremely poor water permeability.

On the other hand, drainage material Na3 using fabrics ①, ② and ② of the present invention
, I'lh5 and l1h7 have less fabric deformation, so
The volume change is small (and the water permeability is also good. Also, the comparative drainage material No. 8, in which the material of the present invention was used and the coating structure was changed, was as poor as Na4.

In addition, regarding the 100% clogging characteristics of the fabric, as shown in the bottom column of Table 2 and Figure 9, the comparative fabric ■ has a large number of soil particles passing through 4-4, and has a large water permeability (+!'j bottom). (soil particles also remained inside the fabric). On the other hand, the fabric (2) of the present invention had less penetration of soil particles, and
There was also little decrease in water permeability (there was almost no retention of soil particles within the fabric). Furthermore, the fabrics ① and ② of the present invention were also good in that they were similar to ②.

In addition, the evaluation method for the above test is as follows: , place it on a sand cloth, and measure the amount of water discharged from the nF wood while applying pressure from the top, and calculate it using the following formula.

(2) Change in water permeability of drainage material Pressurize the drainage material, fill the entire surface of the drainage material with water from one side with a constant water head, measure the water fil discharged in the surface direction, and calculate using the formula below. do.

However, Z: Drainage bond when there is no sheet (3) From the top of the clogging fabric of the drainage material, turbid water with extremely low seismic intensity is allowed to flow under the head of the tree while stirring, and the permeability of the water passing through it is 4. (Measure the rotation angle and calculate the following formula using i, , +,)-.

Water permeability of fabric = permeability of soil particles - What is the initial water permeability rate? 〃Measurement value under water load 1. Water permeation rate after a certain time is 1. The value is measured after a certain time has elapsed in a turbid water Q load by taking out the fabric and washing the surface with fresh water load.

Also, the concentration of turbid water in the effluent is -・)1'! :
Measure the concentration of the turbid water drained over time, and the value will be 1.

〔Effect of the invention〕

The drainage material of the present invention configured as described above has (1) high utilization efficiency of the cross-sectional area of the drainage material due to the perforated sheet;

(2) Despite the perforated sheet, it has high strength and excellent pressure deformation resistance.

(3) By making the fabric hydrophilic, there is a water permeability effect across the long legs from the initial stage.

(4) The fabric has a high fill-coup effect and can be used for a long period of time.

(5) Made of durable materials, it can withstand long-term use.

(6) It is lightweight and easy to remove.

(7) Because it is manufactured in a factory, it has the advantage of high quality.

Therefore, the drainage material of the present invention has extremely excellent characteristics and effects that have not been seen before as a horizontal drainage material for soft ground improvement construction methods, and furthermore, it can be used for purposes other than this purpose. It can be widely used as a flat water material, culvert drainage material for roads, sports facilities, waste treatment plants, etc., backfill drainage material for retaining walls, backs of tunnels, etc.

[Brief explanation of drawings]

Figure 1 is a perspective view of the drainage material, Figure 2 is a sectional view of the perforated uneven sheet, Figure 3 is a plan view of the effective uneven sheet, Figure 4 is a model diagram explaining the principle of the drainage material, and Figure 5. (B) (U)
(71) (=) (f) is a cross-sectional view of a model explaining the structure of the hydrophilic fabric, Fig. 5 (*) is a plan view of Fig. 5 (d), and Fig. 6 is the compressed M layer of the current hydrophilic fabric. An explanatory diagram showing the characteristics, FIGS. 7 and 8 are pressurization characteristic diagrams of the drainage material, and FIG. 9 is a clogging characteristic diagram of the fabric. 1...Perforated uneven sheet (plastic sheet), 2.
...Top (front), 2'...Top (back), 3...
・Side part, 4...Through hole (front), 4'・
...Through hole (M), 5...Cavity part (front), 5'...
・Cavity part (back), 6...Hydrophilic fabric, 7...Joint part, 8...Sparse part, 9...Dense part,
14...height, r7...recess width, a
... Width of side part, b ... Length of top part 1, θ...
・Standing angle of side, W...Water. Figure 2 Figure 3 (・＼)
(D) Figure 5, Figure 6 Pressure (kl-/cryi) Surface pressure (k, y/su)

Claims (1)

[Claims] 1. A composite of a plastic sheet and a hydrophilic fabric, which has a sheet cross section in which hollow recesses and projections are alternately continuous and has through holes at the apex portions of the recesses and/or projections. A drainage material characterized by consisting of. 2. The aperture ratio of the through holes is 0.1 to 0.1 of the transparent area of the sheet.
20% of the drainage material according to claim 1. 3. In the compression history characteristics of the fabric, the surface pressure during compression 5
kg/cm^2 or surface pressure at compression recovery 2kg/c
The drainage material according to claim 1, wherein the fiber filling degree change of the fabric under m^2 is 25% or less, and the fabric distortion is 1/2 or less of the sheet thickness of the fabric. 4. The drainage material according to claim 1, wherein the coverage of the fabric is 95 to 105% with respect to the plastic sheet.