JP7844103B2 - A fence used for both rockfall protection and avalanche prevention. - Google Patents

Description

This invention relates to a fence that can be used for both rockfall protection and avalanche prevention.

To protect roads, houses, and other structures from falling rocks on slopes, protective fences (rockfall protection fences) are installed on the slope side of the roads, houses, and other structures being protected. Typical rockfall protection fences consist of an upper component made up of posts, wire ropes, and wire mesh, supported by a concrete foundation. This structure catches rocks falling from above the slope and prevents disasters.
Such a rockfall protection fence is disclosed in Non-Patent Document 1.
Furthermore, technologies related to rockfall protection fences that have been improved to broaden the range of energy absorption capacity of falling rocks are disclosed in Patent Documents 1 and 2.

https://www.hkd.mlit.go.jp/ky/kn/dou_ken/ud49g700000023a8-att/splaat0000003yer.pdf

Japanese Patent Publication No. 2019-85691 Japanese Patent Publication No. 2019-85692

In areas with snow cover, in addition to rockfall protection on slopes, avalanche prevention is also necessary. From an economic standpoint, it is sometimes possible to incorporate both rockfall protection and avalanche prevention functions into a single protective fence. The protective facilities disclosed in Patent Documents 1 and 2 can also be used as both rockfall protection fences and avalanche prevention fences.

The present invention aims to provide a protective fence that is more suitable as a protective fence that combines the functions of rockfall protection and avalanche prevention, as it can efficiently absorb the energy of falling rocks.

(Composition 1)
A fence for both rockfall protection and avalanche prevention, characterized by comprising: terminal posts erected at both ends; a surface material fixed to the terminal posts and unfolded between the terminal posts; intermediate posts positioned between the terminal posts; and a surface material sliding holding member that allows the surface material to slide between itself and the intermediate posts.

(Structure 2)
The rockfall protection and avalanche prevention fence according to configuration 1, characterized in that the surface material sliding holding member is equipped with a sliding force adjustment mechanism for adjusting the sliding force against the surface material.

(Composition 3)
The rockfall protection and avalanche prevention fence according to configuration 2, characterized in that the sliding force adjustment mechanism adjusts the pressing force that presses the surface material between the surface material sliding holding member and the intermediate support column.

(Composition 4)
The rockfall protection and avalanche prevention fence according to configuration 3, characterized in that the rockfall protection and avalanche prevention fence is provided on or near a slope, and the surface material sliding holding member is positioned on the upper slope side with respect to the intermediate support column.

(Composition 5)
The rockfall protection and avalanche prevention fence according to configuration 4, characterized in that the sliding force adjustment mechanism is configured such that the surface material sliding holding member is formed of an elastic member that elastically deforms when subjected to snow pressure due to snow accumulation, and the surface material is pressed between the surface material sliding holding member and the intermediate support column by the elastic deformation of the surface material sliding holding member.

(Composition 6)
The sliding force adjustment mechanism is configured such that the surface material sliding holding member is slidably attached to the intermediate support column, and the surface material sliding holding member moves when subjected to snow pressure due to snow accumulation, pressing the surface material against the intermediate support column, as described in configuration 4, for a shared fence for rockfall protection and avalanche prevention.

(Composition 7)
The rockfall protection and avalanche prevention fence according to configuration 6, further comprising a biasing member that generates a biasing force in a direction that widens the gap between the intermediate support and the sliding holding member of the surface material.

(Composition 8)
A fence for both rockfall protection and avalanche prevention, as described in any of configurations 5 to 7, characterized in that a snow pressure receiving surface member is attached to the surface material sliding holding member to increase the contact area with the snow.

(Composition 9)
A fence for both rockfall protection and avalanche prevention according to any one of configurations 1 to 8, characterized in that a protrusion or recess is formed on the surface of the sliding holding member of the surface material that faces the surface material.

(Composition 10)
A fence for both rockfall protection and avalanche prevention, according to any one of configurations 1 to 9, characterized in that an upper beam member is provided between the terminal support and the intermediate support or between the intermediate support members, and the surface material is slidably attached to the upper beam member.

(Composition 11)
A fence for both rockfall protection and avalanche prevention, as described in any of configurations 1 to 10, characterized in that the surface material is wire mesh.

According to the present invention, it is possible to provide a protective fence that is more suitable as a combined rockfall protection and avalanche prevention fence, possessing both rockfall protection and avalanche prevention functions.

A schematic front view showing the rockfall protection and avalanche prevention fence according to Embodiment 1 of the present invention. A schematic side view of the rockfall protection and avalanche prevention fence of Embodiment 1. A schematic plan view illustrating the state in which the rockfall protection and avalanche prevention fence of Embodiment 1 receives falling rocks. This diagram illustrates the function of the sliding retaining member for the surface material when the rockfall protection and avalanche prevention fence of Embodiment 1 receives snow. This diagram illustrates the function of the sliding retaining member for the surface material when the rockfall protection and avalanche prevention fence of Embodiment 1 receives snow. A diagram showing an example of a sliding and holding member for a surface material. A schematic diagram illustrating another example of a fence used for both rockfall protection and avalanche prevention. A schematic diagram illustrating another example of a fence used for both rockfall protection and avalanche prevention. This figure shows the mounting structure of the sliding retaining member for the rockfall protection and avalanche prevention fence of Embodiment 2. This diagram shows another example of the mounting structure for the sliding retaining member of the surface material of a fence used for both rockfall protection and avalanche prevention.

The embodiments of the present invention will be described in detail below with reference to the drawings. Note that the following embodiments are merely examples of how the present invention can be implemented, and do not limit the present invention to their scope.

<Embodiment 1>
Figure 1 is a schematic front view (viewed from the lower side of the slope) of the rockfall protection and avalanche prevention shared fence (hereinafter simply referred to as the "shared protection fence") of Embodiment 1. Figure 2 is a side view of the configuration of the shared protection fence 1 at the location of the intermediate support column 12, and also shows enlarged views of the area near the upper and lower ends.
The shared protective fence 1 of this embodiment functions as a rockfall protection fence installed on the slope side of the road or house to be protected, in order to protect roads, houses, etc. from falling rocks on sloping ground (slope or near thereto), and at the same time functions as an avalanche prevention fence to suppress the occurrence of avalanches.
The shared protective fence 1 of this embodiment comprises terminal posts 11 erected at both ends, a wire mesh 13 which is a surface material fixed to the terminal posts 11 and deployed between the terminal posts at both ends, intermediate posts 12 positioned between the terminal posts 11, and a surface material sliding holding member 14 which allows the wire mesh 13 to slide between itself and the intermediate posts 12.

The terminal support column 11 is constructed, for example, from an H-shaped steel beam and is supported by a concrete foundation. The terminal support column itself can be made of any material with the necessary strength, and the supporting structure (foundation) can also be any material that generates the necessary bearing force (for example, a structure that supports the column with anchors).
In this embodiment, the terminal support column 11 is provided with a support member 111 and an attachment member 112 for securing the wire mesh 13.
The support member 111 is a support member that resists the force that causes the wire mesh 13 to be pulled by the impact when it catches a falling rock, which would cause the terminal support 11 to tilt inward. It is not necessarily required if the strength obtained from the terminal support itself (and the foundation) is sufficient.
The mounting member 112 is a steel material bolted to the web of the terminal support 11, which is an H-shaped steel beam, and the end of the wire mesh 13 is fixed to the mounting member 112. In this embodiment, the wire mesh 13 is attached to the terminal support 11 via the mounting member 112 in a horizontal arrangement (arranged so that the rows constituting the wire mesh are in a vertical direction). The mounting member 112 can be any configuration that can fix the wire mesh to the terminal support with the necessary strength, or it may be a configuration in which the wire mesh is fixed directly to the terminal support (without providing a separate mounting member).

In this embodiment, the intermediate support columns 12 are formed from square steel pipes and are arranged between the terminal support columns 11 at predetermined intervals (for example, every 3m to 10m). As shown in Figure 2, the intermediate support columns 12 are positioned on the downward slope relative to the wire mesh 13. As will be explained below, the wire mesh 13 is not fixed to the intermediate support columns 12.
Similar to the terminal posts, the intermediate posts themselves can be any type with the necessary strength, and the supporting structure (foundation) can also be any type that generates the necessary bearing force (for example, a concrete foundation or a structure that supports the posts with anchors). The number of intermediate posts is determined according to the total width of the shared protective fence 1 and the span (distance between posts).

The surface material sliding holding member 14 is provided parallel to the intermediate support 12 on the upper slope side of the intermediate support 12, and as shown in Figure 2, a wire mesh 13 is passed between the surface material sliding holding member 14 and the intermediate support 12.
As shown in Figure 2, the surface material sliding retaining member 14 is attached to the intermediate support column 12 in this embodiment. The attachment to the intermediate support column 12 is performed by the upper end fixing fitting 15T and the lower end fixing fitting 15B. The fixing fittings 15T and 15B are L-shaped fittings, with one end fixed to the intermediate support column and the other end to which the surface material sliding retaining member 14 is fixed, forming a gap S between the surface material sliding retaining member 14 and the intermediate support column 12. The gap S is formed to be equal to or greater than the thickness of the wire mesh 13.
The wire mesh 13, which is fixed to the terminal support 11, passes between the surface material sliding support member 14 and the intermediate support 12, and the wire mesh 13 is not fixed to either the surface material sliding support member 14 or the intermediate support 12. Although it is not fixedly supported, because the wire mesh 13 is positioned between the surface material sliding support member 14 and the intermediate support 12, it is supported against falling over, and the wire mesh 13 is able to fully unfold as a surface material.
In this embodiment, the connection between the fixing hardware 15T and 15B and the surface material sliding holding member 14 and the intermediate support column 12 is shown as a bolted connection, but any method that can provide the necessary strength for each connection (for example, welding) can be used.

Figure 3 is a schematic plan view illustrating the state in which the shared protective fence 1 receives falling rocks.
The wire mesh 13 is not fixed to the intermediate support 12 or the surface material sliding holding member 14, and the spacing S is formed to be greater than or equal to the thickness of the wire mesh 13. Therefore, when the wire mesh 13 catches a falling rock, the wire mesh 13 can slide relative to the intermediate support 12 or the surface material sliding holding member 14.
In other words, the impact energy of the falling rock is efficiently transmitted along the entire length of the wire mesh 13, and the impact energy can be absorbed along the entire length of the wire mesh 13 (however, depending on the impact energy, the energy may not necessarily be transmitted along the entire length of the wire mesh). When the wire mesh receives the impact energy of a falling rock, it elongates due to structural deformation (deformation of the mesh size, etc.) and elongation of the wires that make up the wire mesh. Energy is consumed by the plastic deformation and friction between the members that occur at this time, and the impact energy is absorbed by these, and this effect can be generated along the entire length in the width direction of the wire mesh.
In conventional protective fences, the wire mesh is usually fixed directly or indirectly to the intermediate support posts, and the impact energy is concentrated only in the specific span where the falling rock hits. Therefore, each component needs to have sufficient strength to withstand this. However, with the shared protective fence 1 of this embodiment, it is possible to absorb (disperse) the energy throughout the entire fence, which allows for a reduction in the specifications of each component, thus providing an excellent effect.

On the other hand, when used as an avalanche prevention fence to hold back snow, problems may arise if the wire mesh 13 slides freely.
Snowfall in natural environments is not always uniform due to the influence of topography and other factors. For example, snowdrifts can cause localized areas of heavy snowfall. When such uneven distribution occurs, as conceptually shown in Figure 4(a), a load may be applied only to specific spans in the initial stages of snowfall, causing the wire mesh in those spans to bend significantly. As snowfall progresses, the spans that have already bent significantly may receive further snow loads, potentially leading to damage to the structural members.
To address these problems, the shared protective fence 1 of this embodiment is equipped with a sliding force adjustment mechanism that adjusts the sliding force on the wire mesh (surface material) 13 by adjusting the pressing force that the surface material sliding holding member 14 presses against the wire mesh (surface material) 13 between itself and the intermediate support column 12. This makes it possible to reduce the amount of bending of the wire mesh in a specific span due to uneven snow accumulation.

Figures 4(b) and 5 are schematic diagrams illustrating the sliding force adjustment mechanism of the surface material sliding holding member 14.
The sliding retaining member 14 of this embodiment is made of an elastic material that elastically deforms under the snow pressure when snow accumulates, and has the function of reducing the sliding of the wire mesh 13 (the wire mesh bending significantly over a specific span) by pressing the wire mesh 13 against the intermediate support column 12. The sliding retaining member 14 of the surface material can be made of any material that is elastically flexible, such as a square pipe, flat bar, or round bar.
As shown in Figure 5, as snowfall increases the snow depth SC, the load due to snow pressure is gradually transmitted to the surface material sliding and holding member 14. Since the middle part of the surface material sliding and holding member 14 is not fixed, deflection occurs in the center of the surface material sliding and holding member 14 when subjected to the load, and the wire mesh 13 is sandwiched between them, pressing the wire mesh 13 against the intermediate support column 12. The force fixing the wire mesh 13 becomes stronger as the snow depth SC increases, and as shown in Figure 4(b), this has the function of making the deflection of the wire mesh 13 uniform in each span.
The surface material sliding holding member 14 is an elastic member, and once the snow cover SC is gone, its deflection returns to its original state. Therefore, when a load such as falling rocks or soil occurs in the absence of snow cover SC, the structure does not hinder the function of the wire mesh 13 to slide. In other words, it can effectively protect against falling rocks and prevent avalanches.
Furthermore, the force required to secure the wire mesh during snowfall is only sufficient to maintain uniform deflection of the mesh during the initial to mid-stages of snowfall. After that, as snowfall increases, the snow accumulation in each span will maintain balance, so strong fixing is not necessary.

As described above, the shared protective fence 1 of this embodiment can efficiently absorb the energy of falling rocks, and can also reduce the amount of bending of the wire mesh in a specific span, even in environments where there is an uneven distribution of snow cover. Therefore, it is possible to provide a shared protective fence for rockfall protection and avalanche prevention that is more suitable as a protective fence that combines the functions of both rockfall protection and avalanche prevention.
Furthermore, because it has a relatively small number of parts and requires less work for installation, it is possible to provide a fence that serves both as a rockfall protection and avalanche prevention system at a low cost.

Furthermore, in order to increase the sliding restraint force of the surface material sliding retaining member against the wire mesh when snow is present, a convex or concave portion may be formed on the surface of the surface material sliding retaining member that faces the wire mesh (surface material).
Figure 6 shows an example of such a thing.
The surface material sliding retaining member 14-1 shown in Figure 6(a) has a protrusion 141 formed to match the mesh size of the wire mesh 13. As a result, when the surface material sliding retaining member 14-1 is pressed against the wire mesh 13, an engagement force is generated between them, further suppressing the sliding of the wire mesh 13.
The surface material sliding retaining member 14-2 shown in Figure 6(b) has a recess 142 formed to match the mesh size of the wire mesh 13. As a result, when the surface material sliding retaining member 14-2 is pressed against the wire mesh 13, an engagement force is generated between the two, further suppressing the sliding of the wire mesh 13.
As illustrated in Figures 6(a) and (b), it is preferable to have irregularities that correspond to the mesh size of the wire mesh, but even if the irregularities do not correspond to the mesh size, it is still possible to obtain a restraining force against the sliding of the wire mesh. As an example of such a case, Figure 6(c) shows a surface material sliding retaining member formed from deformed steel bars. Even with such a surface material sliding retaining member 14-3, the restraining force against the sliding of the wire mesh can be improved by its irregularities.

Furthermore, in order to increase the sliding restraint force of the surface material sliding retaining member against the wire mesh when snow is present, a snow pressure receiving surface member that increases the contact area with the snow may be attached to the surface material sliding retaining member.
For example, by attaching a steel plate to the surface material sliding retaining member, the area viewed from the front or back (from the downward or upward side of the slope) is increased, and a greater load due to snow pressure is applied to the surface material sliding retaining member, thereby increasing the restraining force against the sliding of the wire mesh.

Although the sliding support members for the facing material provide support against the tilting of the wire mesh, if the span is long, deflection may occur due to the weight of the wire mesh itself or the weight of snow accumulated on the wire mesh, which may cause the fence height to decrease in the center of the span.
To prevent this, an upper beam member may be provided between the terminal support and the intermediate support, or between the intermediate support, and the wire mesh may be supported (suspended from above) by the upper beam member.
Figure 7 shows an example of such a thing.
In the shared protective fence 1-2 shown in Figure 7, upper beam members 16 are provided between the terminal posts 11 and the intermediate posts 12, and between the intermediate posts 12 themselves. Wire mesh (surface material) 13 is slidably attached to these upper beam members 16 by connecting coils C.
The connecting coil C is designed to wrap around the upper beam member 16 and the wire mesh 13, and has sufficient strength to prevent the wire mesh 13 from bending under its own weight or the weight of snow. However, when impact energy from falling rocks is applied, the connecting coil C is designed to stretch, unravel, or break. This prevents the connecting coil C from getting caught at the point where the intermediate support column 12 and the upper beam member 16 are connected, thereby limiting the sliding of the wire mesh 13 during a rockfall.

As for the wire mesh 13, any wire mesh or other facing material that can meet the specifications for use as a rockfall protection fence and avalanche prevention fence can be used. Energy-absorbing facing materials and energy-absorbing devices disclosed in Patent Documents 1 and 2 can also be used. In addition, reinforcing members may be provided to reinforce the upper or lower part of the facing material as needed.
Figure 8 shows an example of such a thing.
In the shared protective fence 1-3 shown in Figure 8, a surface material 13-1 having an energy-absorbing structure as shown in Patent Document 2 is used, and it is also equipped with an upper wire mesh 13-2 and a lower wire mesh 13-3. The upper wire mesh 13-2 and the lower wire mesh 13-3 are fixed to the end posts, but not to the intermediate posts or the surface material sliding holding members, similar to the wire mesh 13 described above.

In this embodiment, the upper and lower ends of the surface material sliding holding member are attached to the intermediate support column as an example, but the present invention is not limited to this, and for example, only one of the upper or lower ends may be fixed to the intermediate support column.
Furthermore, while this embodiment uses an example where the surface material sliding retaining member is attached to an intermediate support column, the present invention is not limited to this. For example, the surface material sliding retaining member may be composed of a support column that is driven in parallel with the intermediate support column.

<Embodiment 2>
Figure 9 shows the mounting structure (upper part) of the surface material sliding holding member of the shared protective fence 1-4 of Embodiment 2.
Furthermore, regarding the parts of the shared protective fence 1-4 other than the mounting structure of the surface material sliding holding member, the concept is the same as in Embodiment 1, so the explanation here will be simplified or omitted.

In the shared protective fence 1-4 of this embodiment, the mounting structure for the surface material sliding holding member 14-1 includes a sliding receiving portion 15T-1 fixed to the intermediate support column 12 by welding or the like.
The sliding receiving portion 15T-1 is a box-shaped member with an open lower section, and as shown in Figure 9, it houses and holds the end of the surface material sliding holding member 14-1 inside. The sliding receiving portion 15T-1 loosely fits the end of the surface material sliding holding member 14-1 so that it can slide toward/away from the intermediate support column 12. Although not shown in the figure, the lower end of the surface material sliding holding member 14-1 has a similar configuration, and a sliding receiving portion 15B-1, which is the inverted version of the sliding receiving portion 15T-1, is fixed to the intermediate support column 12.
As a result, the sliding holding member 14-1 is attached to the intermediate support 12 so that it can slide towards or away from the intermediate support 12. The sliding holding member 14-1 moves due to the snow pressure from the snow accumulation, and by pressing the wire mesh 13 against the intermediate support 12, it suppresses the sliding of the wire mesh 13.

As described above, the shared protective fence 1-4 of this embodiment provides the same effects and advantages as in Embodiment 1. Furthermore, the sliding holding member for the surface material is not limited to an elastic member (a member that flexes appropriately under snow pressure); any member can be used (of course, an elastic member may also be used).

The surface material sliding retaining member 14-1 is free to slide in the direction of approaching or moving away from the intermediate support column 12, and when the snow cover is gone, the force pressing down on the wire mesh 13 is eliminated, so when a load such as falling rocks or soil occurs when there is no snow cover, it does not basically hinder the function of the wire mesh 13 to slide. However, by providing a biasing member that generates a biasing force in the direction of widening the gap between the intermediate support column and the surface material sliding retaining member, the surface material sliding retaining member may be more actively moved away from the intermediate support column when the snow cover is gone.
Figure 10 shows an example of such a thing.
In the shared protective fence 1-5 of Figure 10, the mounting structure for the sliding retaining member of the surface material of the shared protective fence 1-4 of Embodiment 2 is configured such that the spring 151 generates a biasing force in the direction of widening the gap between the intermediate support and the sliding retaining member of the surface material.
More specifically, a shaft member 152 (here, it is made up of a bolt member as an example) is provided that extends along the sliding direction of the surface material sliding holding member 14-2. A hole is formed in the surface material sliding holding member 14-2, and the shaft member 152 is inserted through this hole. The spring 151 is positioned between the intermediate support column 12 and the surface material sliding holding member 14-2, with the shaft member 152 inserted through it. The configuration of the sliding receiving portion 15T-2 is basically the same as that of the sliding receiving portion 15T-1, except that a bolt hole is formed for fastening the bolt which is the shaft member 152. The lower end has the same configuration as the upper end, and a sliding receiving portion 15B-2, which is the sliding receiving portion 15T-2 inverted, is fixed to the intermediate support column 12, with the shaft member 152 and spring 151 arranged similarly (it is not necessarily required to provide biasing members on both the upper and lower ends; they may be provided on only one).
In the shared protective fence 1-5 having the above configuration, when subjected to snow pressure, the load due to the snow pressure exceeds the elastic force of the spring 151, causing it to clamp the wire mesh 13. On the other hand, when the snow pressure is removed, the elastic force of the spring 151 causes the surface material sliding holding member 14-2 to slide away from the intermediate support 12, thus eliminating the resistance to the sliding of the wire mesh 13.

It goes without saying that various modifications described in Embodiment 1 (such as forming uneven surfaces on the surface material sliding holding member, attaching the snow pressure receiving surface member, attaching the upper beam member, and variations in the surface material) may also be applied in Embodiment 2.

In this embodiment, the wire mesh 13 is shown as being attached to the terminal support 11 in a horizontal configuration (arranged so that the rows of wire mesh are vertical), but the wire mesh may also be arranged in a vertical configuration (arranged so that the rows of wire mesh are horizontal).
Furthermore, in addition to the wire mesh (face material), additional ropes (such as wire ropes) may be provided as appropriate.

It is not necessary to provide the sliding retaining member for the surface material for all intermediate posts. For example, the sliding retaining member may not be provided for intermediate posts close to the terminal post 11. Furthermore, if the installation environment of the shared protective fence is known in advance to be prone to heavy snowfall, the sliding retaining member may be provided only for intermediate posts installed near those areas.

1. ... Fence for protection against falling rocks and avalanches 11. ... End posts 12. ... Intermediate posts 13. ... Wire mesh (face material)
14. Surface material sliding holding member 141. Protrusion 142. Recess 16. Upper beam member 151. Spring (biasing member)

Claims (7)

End support columns erected at both ends,
A surface material fixed to the terminal support and unfolded between the terminal support,
Intermediate support columns are positioned between the terminal support columns and on the downward sloping side relative to the surface material,
A surface material sliding holding member is positioned on the upper slope side of the surface material, and is arranged to allow the surface material to slide in the width direction between itself and the intermediate support column. However, when subjected to snow pressure due to snow accumulation, it clamps and presses the surface material between itself and the intermediate support column, thereby reducing the sliding of the surface material in the width direction .
A fence for both rockfall protection and avalanche prevention, characterized by having the following features. The rockfall protection and avalanche prevention fence according to claim 1, characterized in that the sliding retaining member for the surface material is made of an elastic material that elastically deforms when subjected to snow pressure, and when subjected to snow pressure, the sliding retaining member for the surface material elastically deforms, thereby sandwiching and pressing the surface material between the sliding retaining member for the surface material and the intermediate support column, thereby reducing the sliding of the surface material in the width direction. The rockfall protection and avalanche prevention fence according to claim 1, characterized in that the sliding holding member for the facing material is slidably attached to the intermediate support column, and when the sliding holding member for the facing material is subjected to snow pressure due to snow accumulation, it moves and presses against the facing material between itself and the intermediate support column, thereby reducing the sliding of the facing material in the width direction. The rockfall protection and avalanche prevention fence according to claim 3, characterized by comprising a biasing member that generates a biasing force in a direction that widens the gap between the intermediate support and the sliding holding member of the surface material. A fence for both rockfall protection and avalanche prevention, according to any one of claims 2 to 4, characterized in that a snow pressure receiving surface member is attached to the sliding holding member of the surface material to increase the contact area with the snow. A rockfall protection and avalanche prevention fence according to any one of claims 2 to 5, characterized in that a convex or concave portion is formed on the surface of the sliding holding member of the surface material that faces the surface material. A rockfall protection and avalanche prevention fence according to any one of claims 1 to 6, characterized in that an upper beam member is provided between the terminal support and the intermediate support or between the intermediate support members, and the surface material is slidably attached to the upper beam member.