JP2019190183A - Wire mesh and stone fall countermeasure mesh - Google Patents

Abstract

To provide a wire mesh which improves corrosion resistance or a stone fall countermeasure mesh using the same.SOLUTION: A wire mesh 1 whose a basic form is rhombic has a tensile strength of more than 2,200 N/mm, has a wire diameter of 1.0 mm or more and 3.0 mm or less, and is composed of a plurality of column lines that are spirally formed of a wire plated with zinc aluminum alloy containing 10% or more aluminum.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a diamond-shaped wire net having a basic aspect and a rockfall countermeasure net using the same.

Wire mesh is often used for facilities and construction methods for the prevention and protection of falling rocks on slopes, and as one of such construction methods, wire meshes are stretched along slopes to stabilize the slopes. There is a construction method.
The related art relating to this is disclosed in Japanese Patent Application Laid-Open No. H10-228707.

Special table 2001-522422

Patent Document 1 describes a wire mesh composed of high-strength steel wires for the purpose of reducing the weight of the wire mesh. Considering the use of a wire mesh for a rockfall countermeasure net that is a facility for the prevention and protection of rockfall on slopes, from the standpoint of workability of installation, it is lighter by making it stronger. (Reducing the wire diameter) is preferable.
On the other hand, the rock fall prevention net provided in contact with the outdoor surface and the slope is in an environment that is easily corroded. Reducing the wire diameter for weight reduction increases the surface area per unit volume, which is disadvantageous for corrosion resistance.

  In view of the above points, an object of the present invention is to provide a wire net with improved corrosion resistance, or a rockfall countermeasure net using the same.

(Configuration 1)
It has a tensile strength exceeding 2200 N / mm ² and has a wire diameter of 1.0 mm or more and 3.0 mm or less, and is constituted by a zinc-aluminum alloy plated wire containing 10% or more of aluminum. Wire mesh characterized by.

(Configuration 2)
The wire mesh according to Configuration 1, wherein a deflection amount as a mesh body under the following conditions is 707 mm or more.
Conditions: The net is supported in a cantilever shape in the column line direction, the length of the cantilever is 1000 mm, and the amount of displacement in the vertical direction of the free end at this time is the deflection amount.

(Configuration 3)
With a wire having a tensile strength of 290 N / mm ² or more and less than 1000 N / mm ² , a wire diameter of 1.0 mm or more and 3.0 mm or less, and zinc aluminum alloy plating containing 10% or more of aluminum, Wire mesh characterized by being configured.

(Configuration 4)
The wire mesh is provided with a plurality of column lines formed in a spiral shape by the wires, whereby a basic aspect is formed as a rhombus wire mesh, and an annular portion is formed so that the end of the column line is folded at the end of the column line. In addition, the leading end of the column line is wound around the column line itself, and in the adjacent column line, the annular part of one column line and the annular part of the other column line are linked. 4. The wire mesh according to any one of configurations 1 to 3, wherein the wire mesh is provided.

(Configuration 5)
The wire mesh according to Configuration 4, wherein the diamond wire mesh has a wire mesh angle of 30 ° to 85 °.

(Configuration 6)
6. The wire mesh according to Configuration 4 or 5, wherein the thickness of the wire mesh is 30 mm to 70 mm because the row lines are formed in a spiral shape having a thickness.

(Configuration 7)
The wire mesh according to any one of configurations 1 to 6, wherein the wire is used in a 1 m ² knitted mesh of a wire mesh of 45 m or more.

(Configuration 8)
A rock fall countermeasure network characterized by being formed of the wire mesh according to any one of configurations 1 to 7.

  According to the wire mesh of the present invention and the rock fall countermeasure network using the same, since the zinc aluminum alloy plating containing 10% or more of aluminum is applied, the wire mesh with improved corrosion resistance, or this It is possible to provide a rockfall countermeasure network that has been used.

The figure which shows a part of wire mesh of embodiment which concerns on this invention The figure which shows the edge part of the wire mesh of embodiment which concerns on this invention Graph on corrosion resistance evaluation of zinc aluminum alloy plating (Mr. Nishizaki et al., Civil Engineering Data, 37-1 (1995), P62) Schematic of a state where a wire mesh is supported in a cantilever shape The graph which shows the relationship between the length of a cantilever beam, and the amount of deflection about the conventional rhombus metal mesh, the conventional thick net, and the high strength metal mesh 1 of this embodiment, respectively. The figure which shows another example of the high intensity | strength wire mesh which concerns on this invention The figure which shows the installation state of the falling rock countermeasure net which used the high strength wire net of this invention Schematic showing the installation procedure of the rockfall countermeasure net Schematic diagram showing the structure of a rockfall countermeasure network

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. In addition, the following embodiment is one form at the time of actualizing this invention, Comprising: This invention is not limited within the range.

<Embodiment 1>
FIG. 1 is a diagram showing a wire mesh of the present embodiment, FIG. 1 (a): a front view, FIG. 1 (b): a side view (for simplification, it is a diagram for two column lines, This structure is repeated for the entire wire mesh). FIG. 2A is a diagram showing an end of a wire mesh, and FIG. 2B is a diagram showing an end of a column line.
The wire mesh of this embodiment is a high-strength wire mesh formed as a thick net by a wire having a tensile strength of 2300 MPa (a wire having a tensile strength of more than 2200 MPa and not more than 2800 MPa) plated with zinc-10% aluminum alloy. It is. A thick net is the same as a rhombus metal mesh in the basic form, but as a metal net having a predetermined thickness, the row lines constituting the rhombus metal net are formed in a spiral shape having a thickness. Is formed.
Specifically, a diamond wire mesh having a mesh size of 42 mm, a wire mesh angle of 30 °, and the number of line intersections per meter of 23.8 by a wire plated with zinc-10% aluminum alloy having a wire diameter of 2.0 mm. As shown in FIG. 1B, the spiral of the column line is formed in a substantially rectangular shape (having a substantially straight rising portion 11) in a side view, so that the thickness is 30 mm. Is formed. The wire mesh tension of the high strength wire mesh 1 is 197.1 kN / m.
By forming the high-strength wire mesh 1 with a wire having a high tensile strength, the required strength can be obtained with a thin wire diameter (2.0 mm), and the weight per 1 m ² is 1.45 kg, which is lightweight. Can be formed.

  The high-strength wire mesh 1 is plated with zinc-aluminum alloy containing 10% or more of aluminum, so that it has high corrosion resistance and is lightweight when used as a rockfall countermeasure net provided in contact with an open-air and slope. Therefore, even if the wire diameter is reduced, sufficient corrosion resistance can be obtained.

Fig. 3 shows the evaluation of corrosion resistance of zinc-aluminum alloy plating, excerpted from the Ministry of Construction Public Works Research Institute "Example of corrosion resistance evaluation of zinc / aluminum plating" (Mr. Nishizaki et al., Civil Engineering Technical Data, 37-1 (1995), P62). It is a graph.
The same corrosion resistance evaluation was conducted by conducting a salt spray test (JIS Z 2371) on three types of plated steel wires: hot dip galvanized, zinc-5% aluminum alloy plated, zinc-10% aluminum alloy plated, and corrosion of the plated layer. The amount was investigated.
As shown in FIG. 3, the zinc-5% aluminum alloy plating exhibits a corrosion weight loss of 1/3 or less of the zinc plating, and the zinc-10% aluminum alloy plating is further compared to the zinc-5% aluminum alloy plating. It has about twice the corrosion resistance. That is, by using zinc aluminum alloy plating containing 10% or more of aluminum, the corrosion resistance in practical use is extremely excellent.
The zinc-aluminum alloy plating containing 10% or more of aluminum preferably has an adhesion amount of 150 g / m ² or more. From the viewpoint of increasing the corrosion resistance, the adhesion amount is 290 g / m ² or more. It is more preferable that

As shown in FIG. 2B, the high-strength wire mesh 1 of the present embodiment has an annular portion 121 formed at the end of the column line so that the tip of the column line is folded back. The terminal processing part 12 in which the winding part 122 by which the front-end | tip part of this was wound around the row line itself was formed is provided.
As shown in FIG. 2 (a), the high-strength wire mesh 1 of the present embodiment includes a terminal processing portion 12 (annular portion 121) of one column line and a terminal processing of the other column line in adjacent column lines. The part 12 (annular part 121) is linked.
In a conventional wire mesh, the end portion is left open or knuckle processing is performed. In the case of being cut off, there is a risk that the working efficiency may be deteriorated or the operator or the like may be injured due to the occurrence of a catch at the tip. Such a problem can be reduced by knuckle the end, but the conventional knuckle process simply folds the front end of the row line, so the work efficiency is reduced due to catching as before. There was some risk of injury.
On the other hand, in the high-strength wire mesh 1 of the present embodiment, the annular portion 121 is formed so that the front end of the column line is folded, and the front end portion of the column line is wound around the column line itself. Therefore, the above problem can be further reduced. In addition, it is preferable that the winding number of the winding part 122 shall be 1.5 times or more.
When the high-strength wire mesh 1 of the present embodiment is installed as a rockfall prevention net, the roll-shaped high-strength wire mesh 1 is excellent in deployability when rolled from above the slope, and has good work efficiency. It is.

The high-strength wire mesh 1 of the present embodiment is supported in a cantilever shape in the column line direction so that the length of the cantilever is 1000 mm, and the amount of deflection, which is the displacement in the vertical direction of the free end, corresponds to 977 mm. It is.
The high-strength wire mesh 1 is a flexible wire mesh having a deflection equivalent to 977 mm (707 mm or more) while using a high-strength wire with a tensile strength of 2300 MPa to reduce the weight. When used for facilities and construction methods for the purpose of prevention and protection, etc., the familiarity to the slope (following to the unevenness of the slope) is good, and it is difficult for gaps to form between the slope and the wire mesh, stabilizing the slope soil It can be made.

If the slope is flat, there is no problem with the familiarity with the slope as described above, but there are many irregularities on the actual slope. It is difficult to generalize the size of the unevenness and the corner radius on natural slopes, and it is difficult to generalize this, but considering the range from flat (0 °) to vertical cliff (90 °), The intermediate value is 45 °. The fact that the wire mesh conforms to its 45 ° unevenness by its own weight means that when the wire mesh is supported in a cantilever shape, it bends at approximately 45 degrees.
FIG. 4 shows a schematic diagram of a state in which the wire mesh is supported in a cantilever shape. Here, a simplified diagram is shown, and a cantilever-like wire mesh is linearly bent, but in reality, it is bent in an arc shape. In this arc-shaped deflection, if the line connecting the support end and the free end is approximately 45 °, it can be said that “the wire mesh adapts to its 45 ° unevenness by its own weight”. As shown in FIG. 4, when the cantilever is 1000 mm, the amount of deflection is about 707 mm.
Therefore, when the net is supported in a cantilever shape in the column line direction and the length of the cantilever is 1000 mm, and the amount of deflection in the vertical direction of the free end is the amount of deflection, this is 707 mm or more. If it exists, it can be said that the familiarity to the slope (following to the unevenness of the slope) is good in the above criteria.

One method for forming a wire mesh having a large amount of deflection is to increase the length of the wire used per unit area.
For example, in the case of a certain length of column line, when the wire used for the column line is the shortest, it becomes a simple linear wire (in this case, it cannot be said to be a column line). If the amount of wire used is increased without changing the length as the column line, the number of turns of the spiral of the column line (or the size of the spiral) will increase. Here, when comparing a simple linear wire with a helical row line having a large number of turns, the length of the wire being used is the same as the length as the row line, The amount of deflection is greater in the latter case. Therefore, by increasing the length of the wire used per unit area, it is possible to form a wire mesh with a large amount of deflection.
When using a wire with a wire diameter of 2 mm having a tensile strength exceeding 2200 MPa, a wire of 45 m or more may be used for a 1 m ² wire mesh. In this way, when the net is supported in a cantilever shape in the column line direction and the length of the cantilever is 1000 mm, the amount of deflection can be about 707 mm or more. In addition, it is preferable to use a wire of 50 m or more in a 1 m ² wire knitted net, and it is more preferable to use a wire of 55 m or more. The high-strength wire mesh 1 of the present embodiment uses a 58 m wire for a 1 m ² wire mesh.

FIG. 5 shows a conventional rhombus wire mesh, a conventional thick net, and a high strength wire mesh 1 according to the present embodiment. In supporting the wire mesh in a cantilever shape as shown in FIG. The results of measuring the amount of deflection are shown respectively. The horizontal axis is the length of the cantilever and the vertical axis is the amount of deflection.
The “conventional rhombus wire mesh” has a wire diameter of 3.2 mm (tensile strength: 450 MPa), a mesh size of 67.6 mm, a wire mesh angle of 85 °, and a number of line intersections per meter of 14.8. It is a diamond wire mesh. The “conventional thick net” has a wire diameter of 3.2 mm (tensile strength: 400 MPa), a mesh size of 46 mm, a wire mesh angle of 85 °, and the number of line intersections per meter of 21.7. As in FIG. 1B, the column line spiral is formed in a substantially rectangular shape in side view (having a substantially linear rising portion 11), so that the thickness is formed to be 30 mm.
For the high-strength wire mesh 1, the length of the cantilever is measured every 100 mm up to 600 mm (solid line) for the convenience of the experimental sample, and the approximate curve obtained as a result of the actual measurement (resultingly) A straight line) is shown extended (broken line).
As shown in FIG. 5 (a), the conventional rhombus wire mesh has a deflection amount of about 315 mm when the length of the cantilever is 1000 mm, and is not very well adapted to the slope due to its own weight. On the other hand, the conventional thick net has a deflection amount of about 730 mm when the length of the cantilever is set to 1000 mm, and it can be said that a necessary amount is obtained as the familiarity to the slope. However, this conventional thick net does not use a high-strength steel wire, and therefore requires a certain thickness to obtain the required strength, resulting in a relatively large weight (3.7 Kg / m ^2). ) Considering transportation costs and installation work efficiency on sloping ground, the smaller the weight, the better. Therefore, it is conceivable to use a high-strength steel wire to reduce the weight. However, high strength and light weight are negative factors for “familiarity to the slope due to its own weight”.
On the other hand, the high-strength wire mesh 1 of the present embodiment is not limited to simply “high strength and light weight” as a wire mesh, and as shown in FIG. It is a flexible wire mesh with a deflection amount equivalent to 977 mm, has good conformability to the slope (followability to unevenness of the slope), and does not easily cause a gap between the slope and the wire mesh. In other words, it is excellent in transportation cost and installation work efficiency on sloped land, and in stabilizing slope soil.

In the present embodiment, as a high-strength wire mesh, a thick net having a substantially linear rising portion 11 as illustrated in FIG. 1B has been described as an example, but the wire is formed of a wire having a tensile strength exceeding 2200 MPa. Any configuration may be used as long as the amount of deflection as a net body is 707 mm or more.
FIG. 6 shows another example of a high-strength wire mesh. The high-strength wire mesh 1 ′ shown in FIG. 6 (FIG. 6 (a): front view, FIG. 6 (b): side view) is formed as a diamond wire mesh. Specifically, a wire having a wire diameter of 2.0 mm is formed as a diamond wire mesh having a mesh size of 54 mm, a wire mesh angle of 85 °, and a number of line intersections per meter of 18.5, and the wire mesh tension is 197. 1 kN / m.
By forming the high-strength wire mesh 1 ′ with a wire having high tensile strength, the required strength can be obtained with a thin wire diameter (2.0 mm), and the weight per 1 m ² is 1.15 kg, which is lightweight. Can be formed.

As a high-strength wire mesh, formed with a wire having a tensile strength exceeding 2200 MPa and satisfying the requirement that the amount of deflection as a mesh body is 707 mm or more, the wire diameter of the wire is 1.0 mm or more and 3.0 mm or less. In addition, the tensile strength of the wire is preferably 2800 MPa or less.
When the wire diameter of the wire having a tensile strength exceeding 2200 MPa is less than 1.0 mm, the yield may be significantly reduced due to the occurrence of cracks and breaks during the processing of the wire for manufacturing the wire mesh. Moreover, it is difficult to make the wire diameter of the wire having a tensile strength exceeding 2200 MPa exceed 3.0 mm with a normal production facility at present. Similarly, it is difficult to produce a wire having a tensile strength exceeding 2800 MPa with a normal production facility at present.

  In addition, “the amount of deflection as a net body is 707 mm or more” means selection of strength and wire diameter of “wire having tensile strength exceeding 2200 MPa” and various dimensions ( That is, it is realized by appropriately combining the selection of the mesh size, wire mesh angle, thickness, etc.

<Embodiment 2>
Embodiment 2 is a rockfall countermeasure net formed by the high-strength wire mesh 1 of Embodiment 1, and FIG. 7 is a schematic perspective view showing the rockfall countermeasure net 2 provided on the slope.
The rockfall countermeasure network 2 can prevent and protect rockfalls on slopes and promote greening.

FIG. 8 is a diagram illustrating an outline of a construction process of the rockfall countermeasure net 2, and FIG. 9 is a schematic diagram illustrating a configuration of the rockfall countermeasure net 2.
The rockfall countermeasure net 2 in the second embodiment is basically the same configuration as the conventional rockfall countermeasure net except that the high-strength wire mesh 1 of the first embodiment is used as a wire mesh. Although detailed explanation is omitted, the rock fall prevention net 2 is provided with a high-strength wire mesh 1 for stabilizing the slope over the entire area, and a vertical rope 22 and a horizontal rope 23 for reinforcing and holding the same. And various connecting members (such as the clip 24) for connecting these members to each other and various anchors (such as the cement anchor 21 and the pin anchor 25) for installing on the slope.

The rockfall prevention net 2 of the present embodiment is light in weight and excellent in terms of workability, transportation cost, and the like by using the high-strength wire mesh 1 of the first embodiment, and is supple and familiar with the slope (slope The slope soil is stable, and it is difficult to form a gap between the slope and the wire mesh, and the slope soil can be stabilized.
That is, in the row line direction of the high-strength wire mesh 1, the amount of deflection as a mesh body is 707 mm or more, so that the self-weight of the high-strength wire mesh 1 itself follows the undulations of the slope as described in the first embodiment. Can be familiar. In addition, in the direction perpendicular to the column lines of the high-strength wire mesh 1, the column line spirals are formed in a substantially rectangular shape in side view (having a substantially linear rising portion 11), so that adjacent column lines are mutually connected. (Sliding in the left-right direction in FIG. 1 (b)), and also in this direction, the familiarity with the slope (following to the unevenness of the slope) is good.
As is clear from these, the rockfall prevention net 2 is excellent in workability because it is lightweight in its construction, and when the high-strength wire mesh 1 is spread on the slope, it adapts to the unevenness of the slope by its own weight. The workability of the work of fixing the high-strength wire mesh 1 to the slope by the anchor or the like is also excellent.
In addition, the rockfall countermeasure net 2 of the present embodiment uses the high-strength wire mesh 1 of the first embodiment, so that in the installation work, the high-strength wire mesh 1 wound in a roll shape is rolled from above the slope. It has excellent deployability when deployed and is excellent in workability.
Furthermore, by using the high-strength wire mesh 1 of Embodiment 1, the corrosion resistance is excellent.

  In the case of a rockfall countermeasure net using a conventional high-strength wire mesh, it has high resilience due to its high strength and light weight, and its followability with its own weight to unevenness on a slope is poor. In other words, when the high strength wire mesh is spread on the slope, there are places that are in a floating state with respect to the unevenness of the slope, and the workability of the work of fastening with an anchor or the like at these floating places is deteriorated. It was. In addition, if there is a part that is not familiar to the slope and floats in the installed state, a floating stone or the like is likely to occur there, which leads to falling rocks. The falling rocks themselves are accommodated by the wire mesh (collected below the wire mesh), but if this accumulates, the wire mesh swells, and there is a possibility that it is necessary to remove the accumulated fallen rocks. In order to suppress this, it is necessary to bring the net and the slope into close contact with each other in order to suppress the floating stone itself. However, in the case of a conventional rockfall countermeasure net using a high-strength wire mesh, the resilience is due to the high strength. There are many places where the wire mesh floats against the slope. Therefore, more pin anchors, fasteners, and the like are required to bring the wire mesh and the slope into close contact with each other, which is disadvantageous in terms of work efficiency and cost. In addition, to keep the part floating by the repulsive force in close contact with the slope with a pin anchor or the like means that it is installed in a state where the repulsive force in the direction of pulling out the pin anchor or the like is always generated. There is also a risk that pin anchors may fall out when there is a slight earthquake or other vibration.

On the other hand, according to the rock fall countermeasure network 2 of the present embodiment, as described above, the workability of the construction is excellent, and the followability to the unevenness of the slope is good, so that floating stones are suppressed effectively. Slope soil can be stabilized.
The rockfall prevention net 2 is also suitable as a base material for various slope reinforcement works such as a guest soil seed spraying work and a mortar / concrete spraying work.
When using it as a base material for the guest soil seed spraying work, the thickness of the high-strength wire mesh 1 is preferably 30 mm to 70 mm. If the thickness is less than 30 mm, the layer to be sprayed does not have a sufficient thickness and there is a problem that cracks are likely to occur, and if it exceeds 70 mm, the weight of the layer to be sprayed becomes excessive and tends to collapse. Because.

In the second embodiment, as an example of use of the high-strength wire mesh 1 of the first embodiment, a rockfall countermeasure net provided on the slope in order to stabilize the slope has been described. The application is not limited to this, and it can be used for many purposes.
For example, the high-strength wire mesh according to the present invention may be used as a rockfall protection net provided vertically or vertically with respect to the slope. As described above, the high-strength wire mesh according to the present invention is pliable while having high strength, and has a high energy absorption capability.

In the embodiment, a high-strength wire mesh formed by a wire having a tensile strength exceeding 2200 N / mm ² has been described as an example. However, in applications where the strength as a wire mesh is not required, 290 N / mm ² or more and 1000 N It is good also as a wire mesh formed of a wire having a tensile strength of less than / mm ² , a wire diameter of 1.0 mm or more and 3.0 mm or less, and zinc-aluminum alloy plating containing 10% or more of aluminum. .

  In the embodiment, a thick net is taken as an example, but the present invention is not limited to this, and may have a thickness similar to that of a conventional rhombus metal net.

1. . . High strength wire mesh 11. . . Rising part 12. . . Terminal processing unit 121. . . Annulus 122. . . Winding part 2. . . Rockfall countermeasure network 21. . . Cement anchor 22. . . Vertical rope
23. . . Horizontal rope
24. . . Clip 25. . . Pin anchor

Claims (8)

It has a tensile strength exceeding 2200 N / mm ² and has a wire diameter of 1.0 mm or more and 3.0 mm or less, and is constituted by a zinc-aluminum alloy plated wire containing 10% or more of aluminum. Wire mesh characterized by. The wire mesh according to claim 1, wherein a deflection amount as a mesh body under the following conditions is 707 mm or more.
Conditions: The net is supported in a cantilever shape in the column line direction, the length of the cantilever is 1000 mm, and the amount of displacement in the vertical direction of the free end at this time is the deflection amount. With a wire having a tensile strength of 290 N / mm ² or more and less than 1000 N / mm ² , a wire diameter of 1.0 mm or more and 3.0 mm or less, and zinc aluminum alloy plating containing 10% or more of aluminum, Wire mesh characterized by being configured. The wire mesh is provided with a plurality of column lines formed in a spiral shape by the wires, whereby a basic aspect is formed as a rhombus wire mesh, and an annular portion is formed so that the end of the column line is folded at the end of the column line. Furthermore, the tip of the row line is wound around the row line itself,
The wire mesh according to any one of claims 1 to 3, wherein in the adjacent column lines, the annular portion of one column line and the annular portion of the other column line are linked.   The wire mesh according to claim 4, wherein a wire mesh angle of the rhombus wire mesh is 30 ° to 85 °.   The wire mesh according to claim 4 or 5, wherein the row line is formed in a spiral shape having a thickness so that the thickness of the wire mesh is 30 mm to 70 mm. The wire mesh according to any one of claims 1 to 6, wherein the wire is used in a 1 m ² knitted mesh of a wire mesh of 45 m or more.   A rock fall prevention net, which is formed by the wire net according to any one of claims 1 to 7.

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