JP3492120B2 - Civil engineering tape-like member and civil engineering net member made of this tape-like member - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape-shaped member for civil engineering and a net member for civil engineering comprising the tape-shaped member, and particularly, for reinforcement of ground such as roads and land for construction, and prevention of settlement of embankment on soft ground. The present invention relates to a civil engineering tape member used by being laid in the ground and a civil engineering net member including the tape member.

[0002]

2. Description of the Related Art Conventionally, there are various types of civil engineering net members that are laid and used in the ground to reinforce the ground such as roads and landscaping, and to prevent the settlement of embankments on soft ground. Has been developed and put into practical use, and the applicant also proposed a civil engineering net member in which uniaxially stretched synthetic resin tapes were used as warp threads and weft threads, which were crossed with each other at a predetermined interval and the intersections were welded together. (Japanese Patent Application No. 1-32382).

This civil engineering net member has high tensile strength, is hard to collapse, and has appropriate flexibility and rigidity.
It has various advantages such as easy handling and manufacturing.

[0004]

By the way, when this type of civil engineering net member is laid and used in the soil to reinforce the ground such as roads and land, and to prevent the settlement of embankments on soft ground. , Usually, a water-permeable member such as a non-woven sheet is used together to promote drainage of the soil layer, and a civil engineering net member and a water-permeable member are laid in layers in the soil at a predetermined interval. . However, the work of laying a number of layers of the civil engineering net member and the water permeable member in the soil at a predetermined interval requires manual work, so the work efficiency is low, and the civil engineering net member and the water permeable member are permeable. There was also a problem in terms of construction accuracy, such as variations in the intervals at which the flexible members were laid.

The present invention has been made in view of the problems of the above-described conventional net member for civil engineering and the water permeable member used together therewith, and for civil engineering having a function of draining the soil layer by itself. An object is to provide a tape-shaped member and a civil engineering net member including the tape-shaped member.

[0006]

In order to achieve the above object, a tape-shaped member for civil engineering of the present invention is a uniaxially stretched poly tape.
Core tape made of propylene or ultra-high molecular weight polyethylene
Along the periphery of a long water-permeable member that is laminated or upper and lower surfaces are integrated by extrusion coating or laminated coating of a thermoplastic resin having a high dielectric constant, while imparting water permeability to the thermoplastic resin coating layer. Characterize. Here, "to impart water permeability to the thermoplastic resin coating layer" means that when the tape-shaped member for civil engineering of the present invention is laid in the soil and used, water in the soil passes through the thermoplastic resin coating layer. , Which means that it has a function of being absorbed by the water permeable member located inside thereof. Incidentally, as a specific means for imparting water permeability to the thermoplastic resin coating layer, other than a method of forming this coating layer with an open-cell thermoplastic resin, the coating layer is positioned at least inside the coating layer. There is a method of forming a small hole reaching the water permeable member, and both of them can be used together as required. In addition, polypropylene or ultra high
Core tape made of child polyethylene is a single or multiple core
A stack of tapes can be used.

The tape-shaped member for civil engineering of the present invention comprises a water-permeable member and a water-permeable thermoplastic resin coating layer having a high dielectric constant, which coats the water-permeable member.
By laying the civil engineering tape-shaped member in the soil, the soil layer can be drained, and the civil engineering tape formed with the civil engineering tape-shaped members or a different thermoplastic resin coating layer having a high dielectric constant. -Shaped members cross each other as warp and weft, and high-frequency electrolysis is applied to the intersections, so that thermoplastic resin with high dielectric constant undergoes molecular distortion and molecular friction to be rapidly dielectrically heated and firmly welded. be able to. At this time, since other members having a low dielectric constant are less likely to be dielectrically heated, they do not deteriorate and have high strength,
A high quality net member can be obtained. Also, uniaxial extension
Made from expanded polypropylene or ultra-high molecular weight polyethylene
By stacking core tapes, the tensile strength is extremely high.
A tape-shaped member for grain civil engineering can be obtained.

Further, the water permeable member can be composed of a polyester filament non-woven fabric sheet having a thickness of 1 mm or more.

Since the polyester long-fiber non-woven fabric sheet has good water permeability, strength retention and fatigue resistance, it can maintain good drainage performance for a long period of time.

Further, the water permeable member may be made of a water permeable tubular member. Here, the "tube-shaped member having water permeability" means a net-shaped member having a diameter of about 1 to 3 mm or a tube member made of a synthetic resin having a large number of small holes on the surface, and a large number of the tube-shaped members are arranged in parallel. To form a water-permeable member.

Since the tubular member can be designed freely in terms of water permeability, strength retention, etc., it is possible to obtain a civil engineering tape-like member having drainage performance adapted to the properties of the soil layer to be laid.

The thermoplastic resin is either ethylene-vinyl acetate copolymer or vinyl chloride resin, and it is desirable that the coating thickness is 0.1 mm or more.

As a result, the high-frequency welding property is improved, and under the mild welding conditions, the intersections of the warp yarns and the weft yarns can be firmly welded without damaging other members such as the core tape. In particular, ethylene containing 5 to 35% by weight of vinyl acetate
The vinyl acetate copolymer has a better high-frequency weldability as the content of vinyl acetate increases, and has a low melting point of 140 ° C. or lower, so that other members such as a core tape are damaged by heat when they are covered. Don't worry. The vinyl acetate content is 5
If it is less than wt%, the high frequency weldability tends to be considerably deteriorated, and if it exceeds 35 wt%, the strength of the coating film tends to be insufficient, so that both are not preferable. Further, if the thermoplastic resin coating thickness is less than 0.1 mm, the high frequency welding strength at the intersection of the warp and weft becomes insufficient, and when a large tensile force acts when constructing the civil engineering net member, the intersection is separated. And there is a risk of collapsing,
The coating thickness is preferably 0.1 mm or more.

In the civil engineering net member of the present invention, any one of the above-mentioned civil engineering tape members is used for at least one of the warp yarn and the weft yarn, and the yarn and the thermoplastic resin coating layer having a high dielectric constant are used. It is characterized in that the other thread formed of the civil engineering tape-shaped member is crossed with each other at a predetermined interval, and the respective intersections are high-frequency welded.

In the civil engineering net member of the present invention, the civil engineering net member can be reinforced and drained at the same time by laying the civil engineering net member in the soil.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a tape-shaped member for civil engineering and a net member for civil engineering comprising the tape-shaped member of the present invention will be described below with reference to the drawings.

1 and 2A show an embodiment of the civil engineering tape member of the present invention. This civil engineering tape-shaped member T is obtained by laminating long water-permeable members 2 and 2 on both surfaces of a core tape 3 made of uniaxially stretched polypropylene or ultra-high-molecular polyethylene, and having a high dielectric constant and water-permeability around its periphery. It is formed by extrusion coating with a thermoplastic resin 1 having The thickness t of the civil engineering tape-shaped member T depends on the thickness of the water-permeable members 2 and 2, the core tape 3 and the like, but in consideration of its handleability, etc., 2.0 to 10.0 m.
m, preferably 2.0 to 5.0 mm, and its width W is 10 to 300 mm, preferably 10 to 100 m.
m.

The thermoplastic resin forming the coating layer 1 is a resin having a high dielectric constant and a high frequency welding property, for example,
Vinyl chloride resin, ethylene-vinyl acetate copolymer, etc. are preferably used, and the content of vinyl acetate is preferably 5 to 5.
35 wt% (more preferably 15-30 wt%) ethylene-vinyl acetate copolymer is used. This ethylene-vinyl acetate copolymer has improved high-frequency weldability as the content of vinyl acetate increases, and high-frequency welding is possible under mild welding conditions without damaging the water-permeable members 2 and 2 or the core tape 3. In addition, since the melting point is as low as 140 ° C. or lower, there is no fear that the water-permeable members 2 and 2 and the core tape 3 are damaged by heat when they are coated. In addition,
If the content of vinyl acetate is less than 5% by weight, the high-frequency weldability tends to be considerably deteriorated, and if it exceeds 35% by weight, the strength of the coating film tends to be insufficient, which is not preferable. Further, as a concrete means for imparting water permeability to the thermoplastic resin coating layer 1, in addition to the method of forming the coating layer 1 with an open-cell thermoplastic resin, at least the coating layer 1 is provided in the coating layer 1. Water-permeable members 2 and 2 located inside
There is a method of forming a small hole reaching up to the above, and if necessary, both of them can be used together. As a result, when this civil engineering tape-shaped member is laid and used in the soil, water in the soil can be absorbed through the thermoplastic resin coating layer 1 into the water-permeable members 2 and 2 located inside. it can.

The coating thickness of this thermoplastic resin coating layer 1 is
0.1 mm or more, preferably about 0.5 to 1.0 mm, and 0. If the thickness is less than 1 mm, the welding strength at the intersection of the warp yarn and the weft becomes insufficient when manufacturing a net member for civil engineering, which will be described later. Therefore, when a large tensile force acts on the net member, the intersection portion peels off and collapses. Is likely to occur. Further, it is desirable to form uneven wrinkles 11 on the surface of the thermoplastic resin coating layer 1 for preventing vertical tearing of the tape and improving the weldability.

A synthetic fiber non-woven fabric sheet is generally used as the water permeable member 2. Of these, a polyester long fiber non-woven fabric sheet having good water permeability, strength retention and fatigue resistance, for example, is used. Polyester long-fiber non-woven fabric sheet manufactured by Unitika Ltd. (Part number AN200B (thickness 2.1 mm, water permeability coefficient (in-plane) 5 × 10 ⁻¹ cm / se)
c), AN300B (thickness 3.0 mm, water permeability coefficient (in-plane) 5 × 10 ⁻¹ cm / sec)) is preferably used. In this case, it is desirable to use a polyester long-fiber nonwoven fabric sheet having a thickness of 1 mm or more, preferably about 1.5 to 3.5 mm, which can maintain good drainage performance for a long period of time.

Further, the core tape 3 is a strip-shaped body formed by melt-extruding polypropylene or ultra-high molecular weight polyethylene.
5 to 20 times in the temperature range of 140 ° C, preferably 7 to 10
A uniaxially stretched tape having a thickness of 0.0
5 to 1.0 mm, preferably 0.2 to 0.5 mm is used. In the core tape having a draw ratio of less than 5 times, the improvement in tensile strength due to molecular orientation is not remarkable,
Core tapes having a draw ratio of more than 20 times are not preferable because the tensile strength decreases due to fibrillation. Even when the draw ratio is 5 to 20 times, a core tape having a thickness of less than 0.05 mm tends to lack absolute strength, and a core tape having a thickness of more than 1 mm has high rigidity and is wound. It is also unfavorable since it has poor properties and tends to have poor handleability.

In the civil engineering tape-shaped member T of this embodiment, the long water-permeable members 2 and 2 are laminated on both surfaces of the core tape 3 as described above, and the periphery thereof is extrusion-coated with the thermoplastic resin 1. However, instead of this, the upper and lower surfaces of the water-permeable members 2 and 2 may be laminated and coated with a thermoplastic resin. Further, the core tape 3 is not limited to one layer, and a plurality of core tapes laminated can be used. This makes it possible to easily increase or decrease the tensile strength by changing the number of laminated core tapes, and moreover, a laminate of a plurality of core tapes has a lower rigidity than that of a single core tape having a total thickness. Therefore, there is an advantage that the winding property is good and the handleability is improved even though the tensile strengths are substantially the same.

Although the civil engineering tape-like member of the present invention has been described above, the present invention is not limited to the above-mentioned embodiments, and its configuration can be changed without departing from the spirit thereof. . FIG. 2 shows a modification thereof. Unless otherwise specified, the basic configuration is the same as the civil engineering tape-shaped member T shown in FIGS. 1 and 2A.

In FIG. 2 (b), a long water-permeable member 2 is laminated on one surface of a core tape 3 made of uniaxially stretched polypropylene or ultra-high molecular polyethylene, and its periphery has a high dielectric constant and It is formed by extrusion coating with a water-permeable thermoplastic resin 1.

In FIG. 2 (c), core tapes 3, 3, 3 made of uniaxially stretched polypropylene or ultra-high molecular weight polyethylene having a narrow width are arranged in parallel with each other, and both sides thereof have long water permeability. The members 2 and 2 are laminated, and the periphery thereof is extrusion-coated with a thermoplastic resin 1 having a high dielectric constant and water permeability. In this case, each core tape 3,
Because it can be used as a water passage between the gaps 3 and 4,
The drainage performance can be improved.

The one shown in FIG. 2D (reference example) is extrusion-coated with a thermoplastic resin 1 having a high dielectric constant and water permeability around the long water-permeable member 2 without providing a core tape. It has been configured. In this case, although the tensile strength is reduced, the water-permeable member 2 having a large thickness can be used, so that the drainage performance can be improved.

FIG. 2 (e) shows a core tape 3 made of uniaxially stretched polypropylene or ultra-high molecular polyethylene, and a plurality of water-permeable tubular members 2a are laminated in parallel on both surfaces of the core tape 3. The periphery thereof is extrusion-coated with a thermoplastic resin 1 having a high dielectric constant and water permeability. As the water-permeable tubular member 2a, a tubular member made of a synthetic resin such as polypropylene or polyethylene having a diameter of about 1 to 3 mm or a large number of small holes on the surface can be used. In this case, since the tubular member 2a can be freely designed in terms of water permeability, strength retention, etc., it is possible to obtain a civil engineering tape-shaped member having drainage performance adapted to the properties of the soil layer to be laid. .

Although the civil engineering tape-shaped member of the present invention has been described above, the civil engineering tape-shaped member can be used alone as it is, and as shown in FIG. 3, any of the civil engineering tape-shaped members can be used. Is used for at least one of the warp yarn T1 and the weft yarn T2 (usually the warp yarn T1), and
Reinforcing and draining the soil layer by intersecting the other thread made of the tape-shaped member for civil engineering with a high-dielectric-constant thermoplastic resin coating layer at a specified interval and welding each intersection with high frequency. It is possible to configure a civil engineering net member N that can also perform the above.

In the civil engineering net member N, the warp threads T1 and the weft threads T2 are intersected at right angles with a predetermined interval so as to form a square mesh, and the warp threads T1 and the weft threads T2 are vertically arranged at intersections like a plain weave. The relationship is alternately reversed and overlapped, and the respective intersections are high-frequency welded. The space between the warp yarn T1 and the weft yarn T2 is
It can be appropriately determined in consideration of the use of the net member N. The warp yarn T1 and the weft yarn T2 may intersect diagonally with respect to the length direction of the net body so as to form a rhombic mesh, and the vertical relationship between the warp yarn T1 and the weft yarn T2 is not limited to all intersection points. The warp yarn T1 may be overlaid on the upper side or the lower side of the weft yarn T2.

In the case of high-frequency welding at the intersection of the warp yarn T1 and the weft yarn T2, a high-frequency welding device (not shown) is used in which the same number of welding heads as the warp yarn T1 are provided in a horizontal row at the same intervals as the warp yarn T1. It is desirable to simultaneously weld the intersecting portions arranged in a horizontal line at a high frequency. The welding conditions may be appropriately set in consideration of the type of the thermoplastic resin coating layer 1, the coating thickness, etc., but usually the frequency is 10 to 40 MHz, the output is 3 to 20 kW, the transmission time is 2 to 15 seconds, Pressure is 2
By adopting the condition of 15 kgf / cm ² , high frequency welding can be performed efficiently.

When a high frequency electric field is applied to the intersection of the warp yarn T1 and the weft yarn T2 under the above conditions, the thermoplastic resin coating layer 1 having a high dielectric constant is rapidly dielectrically heated and firmly welded, but the dielectric constant is low. Since the water permeable member 2 and the core tape 3 made of a material are hard to be dielectrically heated, they are hardly thermally deteriorated at the intersection. Therefore, the obtained net member N
Of the core tape 3 in which the warp yarn T1 and / or the weft yarn T2 are uniaxially stretched does not substantially impair the original excellent tensile strength, so that the strength is extremely large, and the welding strength at the intersection of the warp yarn T1 and the weft yarn T2 is large. Therefore, there is no need to worry about the eyes collapsing.

The civil engineering net member N is used by being laid in the soil for reinforcement of the ground such as roads and landslides, and prevention of embankment settlement on soft ground. As shown in FIG. Usually, the end portion is exposed on the slope 5 or the like, and the surplus water in the soil is discharged to the outside through the water-permeable thermoplastic resin coating layer 1 and the water-permeable member 2. In this case, the civil engineering net member N is laid substantially horizontally in the soil, and excess water in the soil can be discharged to the outside according to Darcy's law as shown in the following formulas (1) and (2). It is a thing. Q = kAH / L = kAi (1) v = Q / A = kH / L = ki (2) where Q: flow rate k: water permeability coefficient A: water permeable member Cross-sectional area H: head i: power gradient v: flow velocity L: unit distance.

[0033]

According to the tape-shaped member for civil engineering of the present invention,
Since it is composed of a water-permeable member and a thermoplastic resin coating layer having a high water permeability and covering the water-permeable member, by laying a civil engineering tape-like member in the soil, Along with being able to perform drainage, the civil engineering tape-shaped members or the civil engineering tape-shaped members on which different types of thermoplastic resin coating layers with high dielectric constants are crossed as warp and weft threads, and high-frequency waves are applied at the intersections. By applying the electrolysis, the thermoplastic resin having a high dielectric constant undergoes molecular strain and molecular friction to be rapidly dielectrically heated and firmly welded. At this time, since other members having a low dielectric constant are less likely to be dielectrically heated, they do not deteriorate,
It is possible to obtain a high-strength, high-quality civil engineering net member. Further, the civil engineering net member of the present invention thus obtained, by laying the civil engineering net member in the soil, it is possible to perform both reinforcement and drainage of the soil layer, therefore, in the soil In addition, the work efficiency and the construction accuracy can be improved as compared with the conventional construction method in which the civil engineering net member and the water permeable member are laid in multiple layers at a predetermined interval.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a tape-shaped member for civil engineering of the present invention.

FIG. 2 is a cross-sectional view showing the same modified example.

FIG. 3 is a perspective view showing an embodiment of the civil engineering net member of the present invention.

FIG. 4 is an explanatory view showing a state in which a civil engineering net member is laid.

[Explanation of symbols]

1 Thermoplastic resin coating layer 2 Water-permeable material 2a Tube-shaped member (water-permeable member) 3 core tape N Civil engineering net material T Civil engineering tape

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-106217 (JP, A) JP-A-8-121094 (JP, A) JP-A-3-180611 (JP, A) JP-A-8- 151634 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) E02D 3/00 102 E02D 3/10 103 E02D 17/18

Claims (5)

(57) [Claims] 1. A uniaxially stretched polypropylene or ultra high content
In addition to extruding or laminating a thermoplastic resin having a high dielectric constant on the periphery or both upper and lower surfaces of a long water-permeable member in which a core tape made of child polyethylene is laminated, the water permeability of the thermoplastic resin coating layer is achieved. A tape-shaped member for civil engineering, which is characterized by imparting properties. 2. The water-permeable member is made of a polyester long-fiber nonwoven fabric sheet having a thickness of 1 mm or more.
The tape-shaped member for civil engineering according to claim 1 . 3. The tape-shaped member for civil engineering according to claim 1 , wherein the water-permeable member is a water-permeable tube-shaped member. 4. The thermoplastic resin is either an ethylene-vinyl acetate copolymer or a vinyl chloride resin and has a coating thickness of 0.1 mm or more .
The tape-shaped member for civil engineering according to 2 or 3 . 5. A tape-shaped member for civil engineering according to any one of claims 1 to 4 is used for at least one of warp yarns or weft yarns to form the yarn and a thermoplastic resin coating layer having a high dielectric constant. A net member, characterized in that the other thread made of a civil engineering tape-shaped member is crossed with each other at a predetermined interval, and the respective intersections are high-frequency welded.