Falling Rock Protection Fence

Abstract

Provided is a rockfall protection fence that can efficiently absorb rockfall energy while having a simple structure. 【Solution means】The protection fence 1 of the present invention includes a plurality of columns 10 erected at the upper part of the slope X at intervals, an upper side rope 30 horizontally arranged between the upper parts 10a of the plurality of columns 10, a support pressure rope 40 horizontally arranged between the bases 10b of the plurality of columns 10, and a net 20 suspended from the upper side rope 30 to the lower part of the slope X. The support pressure rope 40 is passed through the slope valley side of the column 10 and the net 20, and both ends of the support pressure rope 40 are fixed to the slope X. Thus, the support pressure rope 40 divides the net 20 into a blocking surface A that unfolds along the plurality of columns 10 and a guiding surface B that unfolds below the plurality of columns 10. The rock mass Y falling from the slope mountain side is impacted by the blocking surface A, and the rock mass Y after being impacted is configured to be guided to the foot of the slope through the space between the guiding surface B and the slope X.

Description

Technical Field

[0001] The present invention relates to a rockfall protection fence, and particularly to a rockfall protection fence that has a simple structure and can efficiently absorb rockfall energy.

Background Art

[0002] In recent years, due to the influence of climate change, local heavy rains and abnormal weather have increased. Along with this, the destabilization of slopes has progressed, and rockfall disasters have occurred frequently in mountainous areas and steep slopes. For this reason, rockfall protection measures to prevent infrastructure such as roads, railways, and buildings, as well as human casualties from rockfall disasters, are highly regarded. Rockfall protection measures are classified into preventive works and protective works. Preventive works are technologies that prevent the occurrence of rockfalls by removing loose rocks and boulders on slopes or fixing them to the slopes. Protective works are technologies that capture rock blocks caused by rockfalls with facilities such as rockfall protection fences installed on slopes to prevent damage. Patent Documents 1 to 4 disclose pile-type rockfall protection fences in which a net is deployed between columns penetrated into the upper part of a slope. Patent Documents 5 to 8 disclose high-energy pocket-type rockfall protection fences in which the front of the slope is covered with a net and an opening is provided between the columns at the upper part of the net (Fig. 8(a)).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

[0004] The prior art has the following problems. <1> Since the pile type rockfall protection fence has a structure that completely captures rock blocks at the upper part of the slope, high-rigidity members and large-scale foundation work are required, resulting in increased installation costs. Also, after a rockfall, since the rock blocks remain at a high position, removal work requires time and cost. <2> Since the pocket type rockfall protection fence has an opening that is widely open on the mountain side, it is impossible to predict at which position of the net the flying rock blocks will collide. For this reason, a wire mesh with a strength corresponding to the impact energy of the rock blocks is required for the entire net, resulting in increased installation costs. Also, there is a risk that the collided rock blocks will push the wire mesh to the valley side and freely fall from that position, causing significant damage to the legal buttocks (Fig. 8(b)).

[0005] An object of the present invention is to provide a rockfall protection fence for solving the above problems. [Means for Solving the Problems]

[0006] The rockfall protection fence of the present invention includes a plurality of columns erected at intervals at the upper part of the slope, an upper side rope horizontally disposed between the upper parts of the plurality of columns, a support pressure rope horizontally disposed between the bases of the plurality of columns, and a net suspended from the upper side rope to the lower part of the slope. The support pressure rope is passed through the slope valley side of the column and the net, and both ends of the support pressure rope are fixed to the slope. By this, the net is divided by the support pressure rope into a blocking surface that unfolds along the plurality of columns and a guiding surface that unfolds below the plurality of columns. The rock blocks falling from the slope mountain side are impacted by the blocking surface, and the rock blocks after being impacted are configured to be guided to the legal buttocks through between the guiding surface and the slope.

[0007] The rockfall protection fence of the present invention may have different inclination angles in the vertical direction of the blocking surface and the guiding surface.

[0008] The rockfall protection fence of the present invention may be such that the net of the blocking surface is made of a material and / or structure with higher strength than the net of the guiding surface.

[0009] The rockfall protection fence of the present invention may be configured by combining a diamond wire mesh and a ring net attached to the diamond wire mesh for the net of the blocking surface, and the ring net may be a wire mesh formed by inserting and connecting a plurality of metal ring materials into each other within the rings.

[0010] The rockfall protection fence of the present invention may be provided with friction sliding type buffer devices attached to both ends of the upper side rope and the bearing rope, and the buffer device attached to the bearing rope may be configured to be more easily slidable than the buffer device attached to the upper side rope.

Effects of the Invention

[0011] Since the rockfall protection fence of the present invention has the above configuration, it has at least one of the following effects. <1> By using a double energy absorption function that absorbs energy by receiving the impact of rock blocks with the blocking surface erected on the slope and then attenuates the energy with the guiding surface suspended from the slope, it can efficiently absorb the rockfall energy with a simple structure and reduce the damage caused by rockfalls. <2> By sliding between the guiding surface and the slope, the falling speed of the rock blocks can be decelerated and safely guided to the legal buttocks. Therefore, no work on the slope is required and the removal of rock blocks is easy. <3> Since the blocking surface and the guiding surface are separated by the bearing rope, there is no risk that the rock blocks will directly collide with the guiding surface and freely fall to the legal buttocks.

Brief Description of the Drawings

[0012]

Figure 1

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Figure 8

Mode for Carrying Out the Invention

[0013] Hereinafter, the rockfall protection fence of the present invention will be described in detail with reference to the drawings. In the present invention, the "front surface" of the net means the surface on the valley side of the slope, and the "back surface" means the surface on the mountain side of the slope.

Example

[0014] <1> Rockfall protection fence (Fig. 1) The rockfall protection fence 1 is a facility for protecting roads, railways, buildings, etc. from rock blocks Y sliding down the slope X. The rockfall protection fence 1 includes at least a plurality of columns 10 erected at intervals on the upper part of the slope X, a net 20 covering the front surface of the slope X, an upper side rope 30 horizontally arranged between the upper parts 10a of the columns 10, and a support pressure rope 40 horizontally arranged between the base parts 10b of the columns 10. In this example, further, an intermediate rope 50 horizontally arranged in the middle part of the net 20, a lower side rope 60 horizontally arranged at the lower part of the net 20, a plurality of vertical ropes 70 arranged in the height direction of the net 20, and a friction sliding type buffer device 90 provided at the ends of the upper side rope 30 and the support pressure rope 40 are provided. In addition, an anchor may be buried in the slope X on the mountain side and connected to the column 10 with a stay rope. The net 20 is connected to the upper side rope 30 and suspended downward from the upper side rope 30 to the lower part of the slope X. The support pressure rope 40 crosses the front side of the column 10 and the net 20 and presses the front surface of the net 20.

[0015] <2> Column (Fig. 2) The support column 10 is a member that supports the net 20. The support column 10 has a grounding portion 10c driven into the ground and is erected on the slope X. In this example, the support column 10 is erected vertically, but it may also be erected with an inclination toward the valley side of the slope. In this example, as the support column 10, a concrete-filled steel pipe is adopted, in which steel bars and wires are inserted into a circular steel pipe and filled with concrete. In addition to the mutual restraint effect between the circular steel pipe and the concrete, the steel bars and wires arranged in the concrete can assist the tensile force of the circular steel pipe as tension members, so that the concrete-filled steel pipe can exhibit high flexural strength. Mounting portions 11 for inserting the upper-side rope 30 and the pressure-supporting rope 40 are provided at least at the upper part 10a and the base part 10b of the support column 10. Here, the base part 10b means the lower part of the above-ground portion of the support column 10. In this example, the mounting portion 11 is a loop structure provided on the front side of the support column 10. The structure, height, diameter, grounding depth, interval between the support columns 10, etc. are appropriately designed according to the geology of the slope X and the assumed scale of falling rocks. Further, the support column 10 is not limited to a structure having a grounding portion 10c, and may be of a type erected on the upper surface of a grounding plate fixed to the slope X with an anchor bolt or the like.

[0016] <3>Net (Figure 2) The net 20 is a member having both a buffering function and a guiding function against falling rocks. In this example, a diamond wire mesh 21 is adopted as the net 20. Since the diamond wire mesh 21 is flexible and has a large impact absorption capacity, it is particularly suitable for the net 20 of the falling-rock protection fence 1. However, the net 20 is not limited to the diamond wire mesh 21, and other metal wire meshes or fiber meshes may be adopted. A connecting coil (connecting member 80) is wound around the upper-side rope 30 between the support columns 10, and the connecting coil is wound into the meshes of the net 20, so that the net 20 is suspended from the upper-side rope 30 and deployed. However, the connecting member 80 of the net 20 is not limited to the connecting coil, and may be a shackle or the like. Further, without using the connecting member 80, the upper-side rope 30 may be inserted through the meshes of the net 20 and connected.

[0017] <4>Upper-side rope The upper side rope 30 is a rope for suspending the net 20. In this example, a wire rope is adopted as the upper side rope 30. Since the wire rope has high tensile strength and weather resistance, it is particularly suitable. However, the upper side rope 30 is not limited to a wire rope, and a resin rope, a high-strength fiber rope, etc. may be adopted. The upper side rope 30 is inserted into the attachment portion 11 of the upper portion 10a of the support column 10 and fixed to an anchor buried in the slope X at both ends. With this structure, the upper side rope 30 can slide across the support column 10, so that the energy absorption efficiency due to the impact on the net 20 is increased.

[0018] <5>Support pressure rope The support pressure rope 40 is a rope that presses the front surface of the net 20 and constitutes a blocking surface A and a guiding surface B on the net 20. In this example, a wire rope is adopted as the support pressure rope 40. However, it is not limited to this, and a resin rope, a high-strength fiber rope, etc. may be used. The support pressure rope 40 is disposed on the front side of the support column 10 and the net 20, inserted into the attachment portion 11 of the base portion 10b of the support column 10, and fixed to an anchor buried in the slope X at both ends. The support pressure rope 40 is preferably disposed with a slight slack in order to allow the rock mass Y to pass under it during a rockfall.

[0019] <6>Division of the net The rockfall protection fence 1 of the present invention has one feature in that the net 20 is divided by the support pressure rope 40 into a blocking surface A above the support pressure rope 40 and a guiding surface B below the support pressure rope 40. The blocking surface A is a surface that directly receives the impact of the rock mass Y that spreads along a plurality of support columns. The upper and lower parts of the blocking surface A are moored to the slope X by an anchor via the upper side rope 30 and the support pressure rope 40. The guiding surface B is a surface that receives the rock mass Y after the energy dispersion by the blocking surface A and guides it to the gully. The upper and lower parts of the guiding surface B are moored to the slope X by an anchor via the support pressure rope 40 and the lower side rope 60. In this example, due to the bearing pressure of the bearing rope 40, the surface angles (the inclination angles in the vertical direction) of the blocking surface A and the guiding surface B are different. Specifically, the blocking surface A inclines toward the valley side with respect to the guiding surface B. Therefore, it is easy to capture the rock block Y sliding from the mountain side on the blocking surface A.

[0020] <7>Intermediate rope, lower side rope, vertical rope The intermediate rope 50, the lower side rope 60, and the vertical rope 70 are ropes for mooring the net 20 to the slope X. In this example, a wire rope is adopted as each rope. However, it is not limited to this, and a resin rope, a high-strength fiber rope, etc. may also be used. The intermediate rope 50 and the lower side rope 60 are horizontally arranged at the middle part in the height direction and the lower side of the net 20 respectively, and both ends are fixed to the anchors embedded in the slope X. The intermediate rope 50 is arranged in an appropriate number at predetermined intervals in the height direction. The vertical rope 70 is arranged in the height direction of the net 20 along the inclination of the slope X, the upper end is connected to the upper side rope 30 or the support 10, and the lower end is fixed to the lower side rope 60 or the anchor embedded in the ground. The vertical rope 70 is arranged in an appropriate number at predetermined intervals in the horizontal direction.

[0021] <8>Function of the rockfall protection fence The rockfall protection fence 1 functions as follows when a rockfall occurs. The rock block Y sliding from the mountain side of the slope of the rockfall protection fence 1 collides with the blocking surface A between the supports 10. The collision energy of the rock block Y is efficiently absorbed by the blocking surface A through the deformation of the net 20, the elongation of the upper side rope 30 and the bearing rope 40, the deformation of the support 10, and the sliding of the buffer device 90 (Figure 3(a)). At the same time, the bearing rope 40 is pushed out to the valley side and deformed on the net 20 of the blocking surface A, and an opening downward is formed between the bearing rope 40 and the slope X. The rock block Y passes through the opening and slides down below the bearing rope 40 (Figure 3(b)). After the passage of the rock mass Y, the support pressure rope 40 that had extended toward the valley side restores, the opening narrows, and the net 20 of the guiding surface B is drawn toward the slope X side. The rock mass Y slides down while decelerating between the slope X and the guiding surface B (Fig. 4(c)), and is safely guided along the slope X to the toe while the energy is absorbed by the deformation of the net 20 of the guiding surface B (Fig. 4(d)). As described above, the rockfall protection fence 1 of the present invention directly receives the impact of the rock mass Y with the blocking surface A erected between the columns 10, absorbs the impact energy, and then additionally attenuates the energy by sliding it between the slope X and the guiding surface B. With the dual energy absorption function, it is possible to efficiently suppress the damage caused by rockfalls with a simple structure. In addition, since it is not a structure in which a rock mass directly collides with the guiding surface like the pocket-type rockfall protection fence of the prior art, there is no risk of the rock mass freely falling to the toe.

Example

[0022] [Example where the net of the blocking surface is of higher strength than the net of the guiding surface] Since the net 20 of the blocking surface A directly receives the impact of the rock mass Y, high strength is required. On the other hand, since the net 20 of the guiding surface B guides the rock mass Y after the energy is dispersed by the blocking surface A, the same strength as the blocking surface A is not required. Therefore, in this example, the net 20 of the blocking surface A is composed of a material and / or structure with higher strength than the net 20 of the guiding surface B. Specifically, for example, the net 20 of the guiding surface B is composed of a diamond wire mesh 21, and the net 20 of the blocking surface A is composed of a high-strength wire mesh made of high-tensile steel wire. In addition, other configurations may be adopted, such as making the wire diameter of the diamond wire mesh 21 of the blocking surface A thicker than that of the diamond wire mesh 21 of the guiding surface B, making the mesh size of the diamond wire mesh 21 of the blocking surface A smaller than that of the diamond wire mesh 21 of the guiding surface B, and reinforcing only the diamond wire mesh 21 of the blocking surface A with a ring net 22 (Example 3). In this example, by eliminating the excessive performance of the net 20 of the guiding surface B that does not directly receive the impact of the rock mass Y, the installation cost of the rockfall protection fence 1 can be reduced.

Example

[0023] [Example of installing a ring net on the net of the blocking surface] In this example, the net 20 of the blocking surface A is composed of a combination of a diamond wire mesh 21 and a ring net 22 (Fig. 5). The ring net 22 is a wire mesh formed by connecting a plurality of ring members with a diameter of about 30 to 40 cm, which are formed by winding iron wires multiple times, through each other inside the rings. The ring net exhibits an excellent impact dispersion function when the ring members are deformed during impact. The ring net 22 is deployed on the front or back surface of the diamond wire mesh 21 and connected to the diamond wire mesh 21 with a connecting fitting such as a shackle. In this example, by reinforcing the diamond wire mesh 21 with the ring net 22, local loads caused by the collision of the rock mass Y can be dispersed, and deformation and damage of the net 20 can be suppressed. Also, when the net 20 of the blocking surface A is made stronger than the net 20 of the guiding surface B as in Example 2, it is not necessary to switch the specifications of the diamond wire mesh 21 between the blocking surface A and the guiding surface B. After suspending the diamond wire mesh 21 of the same specification from the upper side rope 30, if the ring net 22 is installed only on the blocking surface A, it can be reinforced, so the construction is easy and the installation cost can be suppressed. Note that the ring net 22 may be provided not only on the blocking surface A but also on both the blocking surface A and the guiding surface B (Fig. 6).

Example

[0024] [Example of making the buffer device of the support pressure rope easier to slide] In this example, a difference is made in the fastening force between the buffer device 90 installed on the upper side rope 30 and the buffer device 90 installed on the support pressure rope 40, and the support pressure rope 40 is configured to be easier to slide than the upper side rope 30. Specifically, for example, a method of fastening the bolts of the buffer device 90 of the support pressure rope 40 weaker than those of the buffer device 90 of the upper side rope 30, a method of making the buffer device 90 of the support pressure rope 40 a product with a weaker fastening force than the buffer device 90 of the upper side rope 30, a method of reducing the number of buffer devices 90 attached to the support pressure rope 40 compared to the number of buffer devices 90 of the upper side rope 30, etc. can be adopted. When the rock mass Y collides with the blocking surface A, tension is generated in the pressure-bearing rope 40, causing sliding between the pressure-bearing rope 40 and the buffer device 90, and the excess length portion 41 is pulled out, thereby attenuating the tension and absorbing the falling rock energy (Fig. 7). In this case, since the rope tension at which the pressure-bearing rope 40 starts to slide is smaller than the rope tension at which the upper-side rope 30 starts to slide, when the blocking surface A receives the impact of the rock mass Y, the excess length portion of the pressure-bearing rope 40 slides ahead of the upper-side rope 30, making it easier for the opening between the pressure-bearing rope 40 and the slope X to widen. This enhances the capturing effect of the rock mass Y.

Explanation of Reference Numerals

[0025] 1 Rockfall protection fence 10 Support column 10a Upper part 10b Base part 10c Anchoring part 11 Mounting part 20 Net 21 Diamond wire mesh 22 Ring net 30 Upper-side rope 40 Pressure-bearing rope 41 Excess length portion 50 Intermediate rope 60 Lower-side rope 70 Vertical rope 80 Connecting member 90 Buffer device A Blocking surface B Guide surface X Slope Y Rock mass

Claims

1. A plurality of support columns erected vertically at the upper part of the slope with intervals therebetween; An upper side rope horizontally arranged between the upper parts of the plurality of support columns; A support pressure rope horizontally arranged between the bases of the plurality of support columns; A net suspended from the upper side rope to the lower part of the slope, and comprising: The support pressure rope is passed through the slope valley side of the support column and the net, and both ends of the support pressure rope are fixed to the slope. By this, the support pressure rope divides the net into a blocking surface that unfolds along the plurality of support columns and a guiding surface that unfolds below the plurality of support columns; Characterized in that a rock mass falling from the slope mountain side is impacted by the blocking surface, and the rock mass after impact can be guided to the toe through between the guiding surface and the slope. Rockfall protection fence.

2. Characterized in that the inclination angles of the blocking surface and the guiding surface in the vertical direction are different. The rockfall protection fence according to Claim 1.

3. Characterized in that the net of the blocking surface is made of a material and / or structure with higher strength than the net of the guiding surface. The rockfall protection fence according to Claim 1 or 2.

4. The net of the blocking surface is composed of a combination of a diamond wire mesh and a ring net attached to the diamond wire mesh; Characterized in that the ring net is a wire mesh formed by inserting and connecting a plurality of metal ring materials into each other within the rings. The rockfall protection fence according to Claim 3.

5. Comprising friction sliding type buffer devices attached to both ends of the upper side rope and the support pressure rope; Characterized in that the buffer device attached to the support pressure rope is configured to be more easily slidable than the buffer device attached to the upper side rope. The rockfall protection fence according to Claim 1.

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