JP5079293B2 - Rock fall protection device - Google Patents

Description

  The present invention relates to a rockfall protection device, and more particularly to a so-called curtain-type rockfall protection device that is suspended and installed so that the lower end edge of a net-like body reaches the lowest position of a slope.

  2. Description of the Related Art Conventionally, as a slope falling rock protection device, a configuration is known in which a plurality of support columns are installed, a belt-like mesh body is held by the formed column array, and the falling rocks from above are received by the mesh body. In other words, the upper and lower edges of the mesh body are fixed to the upper and lower ends of each strut, and each strut is supported from the mountain side by a wire rope, etc. is there.

  In addition, the net is attached to the rope suspended on the column of columns at the upper edge, the suspended lower edge reaches the horizontal ground area at the lowest position of the slope, and the lower edge is the legal A so-called curtain-type rock fall protection device is also known which is fixed at the lowest position of the surface. In such a curtain-type rockfall protection device, instead of catching a fallen stone in the middle of the slope and stopping the fall, the fallen stone falls between the slope surface and the mesh body, and the most It reaches the lower level horizontal ground and is collected in the mesh body. Therefore, when a space for collecting rock fall can be provided at the lowest position of the slope, a curtain-type rock fall protection device that is easy to perform post-fall rock fall protection is preferably used.

  As such curtain-type rock fall protection devices, there are Japanese Patent No. 3258994 (Patent Document 1) and Japanese Patent No. 2916633 (Patent Document 2). These patent documents disclose curtain-type rockfall protection devices. For example, in a large-span slope area, a plurality of vertical ropes and horizontal ropes are incorporated into a wire mesh that is stretched over the entire area and reinforced. The disclosed structure is disclosed.

  In addition, a so-called ring net is known as a net used to stop rockfalls and absorb energy. For example, Japanese Patent No. 3131666 discloses a fence-type protection device that stretches a net between upper and lower ends of a support column, and discloses a ring net that is a net body configured by combining ring-shaped members as a net. The ring-type net is formed in a net shape so that one ring-shaped member is connected to intersect with four surrounding ring-shaped members and has a predetermined spread. In general, one ring-shaped member has a diameter of about 15 cm to 50 cm and is formed of a steel wire. As will be described later, a wire having a wire diameter of 3 mm to 4 mm is wound a plurality of times and has a tensile strength of 500 to 2000 N / mm 2.

  Such a ring-type net is extremely excellent in absorbing a large amount of energy in a large rock fall, which is based on the following net displacement behavior when subjected to a rock fall impact.

(1) Time until a load is applied to the intersection of ring-shaped members connected so as to cross each other (net fitting time)
(2) Elastic displacement timing when the ring-shaped member is deformed while maintaining a circular shape (3) The ring-shaped member is circular to quadrangular (when each ring-shaped member is connected to four ring-shaped members) or hexagonal (4) Elastic displacement timing in the extension direction of the wire due to the load acting on the intersection (5) At the intersection Timing of plastic displacement in the direction of elongation of the wire due to the applied load (6) Breakage of the wire As described above, the ring net has a very large rockfall energy due to the deformation of (1), (2) and (3) above. Can be absorbed.

Japanese Patent No. 3258994 Japanese Patent No. 2916633 Japanese Patent No. 3131666

  In the case of the curtain-type rockfall protection device disclosed in Patent Documents 1 and 2, the vertical and horizontal ropes for reinforcement incorporated in the wire mesh cannot be expected to be stretchable in the extension direction. Therefore, stress concentration tends to occur on the anchor that fixes the vertical and horizontal ropes when a rockfall impact is applied. Since the impact of falling rocks is not absorbed or attenuated by the vertical and horizontal ropes, the stress is instantaneously transmitted to the wire mesh, the struts, and the anchor rope, and the impact force may cause the anchor rope to break. This situation means that there is a possibility that the function of absorbing rock fall energy cannot be fully exerted for swarm rocks and large rock falls.

  In addition, the rock fall protection device (fence-type installation form) using the ring type net disclosed in Patent Document 3 effectively utilizes the function of the ring type net. In this case, a proposal of a configuration that takes advantage of the ring net is expected.

  An object of the present invention is to provide a curtain-type rock fall protection device that can accurately absorb a wide range of rock fall energy from absorption of large energy due to the fall of a large stone to control of a small fall rock.

In order to solve the above-mentioned problem, the rock fall protection device according to claim 1,
A strut row having a plurality of struts arranged at predetermined height positions on the slope and spaced at a predetermined interval and fixed to a natural ground so as to be rotatable at least on the valley side, and each of the struts and the natural ground A support rope suspended between the mountain side and maintaining the standing state of each column, a main rope suspended from the column, and an upper edge portion suspended by the main rope, In the rock fall protection device including the net-like body fixed to the ground at the lowest position,
The net-like body includes a first net body configured in a net shape by connecting a plurality of ring-shaped members to a plurality of adjacent ring-shaped members so as to cross each other, and the main rope to the first net body. Rutotomoni and a second network having a finer stitches than the first mesh member hung overlaps,
The second net is provided in the entire area from the main rope to the lower final position of the slope,
The first net is provided not in the entire area but in a part of a predetermined length range downward from the main rope .

As a result, in the so-called curtain-type rockfall protection device that suspends and installs the mesh body on the slope, the first mesh body that is a so-called ring-type net having excellent rockfall energy absorption capability can be utilized. It can cope with large rocks and swarms. On the other hand, since the second net is also suspended together, it is possible to stop small rockfalls that cannot be stopped by the first net. In addition, since the ring net, which is the first net, is installed only in the upper region, the weight burden on the main rope is reduced, and at the same time, the burden on the support rope that maintains the standing state thereof is also reduced. It is reduced. Furthermore, the installation cost of the first net body can be reduced. On the other hand, the trajectory of a stone that falls on a slope is not a route parallel to the slope, and may jump greatly on the way depending on the undulations of the slope. If the place where such falling rocks are likely to jump out of the slope can be covered with the first mesh body, the function of the mesh body in the curtain-type falling rock protection device can be appropriately exhibited. In other words, by installing the position of the struts appropriately according to the slope of the slope, a large impact of falling rocks is absorbed by the first mesh body, and in the area below the slope surface, the second mesh body collects falling rocks. It can be adjusted to do.

The rock fall protection device according to claim 2 is:
A strut row having a plurality of struts arranged on a slope at a predetermined interval and fixed to a natural ground so as to be rotatable at least on the valley side, and suspended between each of the struts and the mountain side of the natural ground And a support rope that maintains the standing state of each support column, a main measure rope suspended from the support column, and an upper edge portion is suspended by the main measure rope, and is grounded at the lowest position of the slope. In a rock fall protection device including a fixed mesh body,
The mesh body overlaps the first mesh body with a first mesh body configured in a mesh shape by connecting a plurality of ring-shaped members to a plurality of adjacent ring-shaped members so as to cross each other. And a second net having a finer stitch than the first net, and the first net is arranged on the mountain side and the second net is arranged on the valley side. It is characterized by that.

As a result, in the so-called curtain-type rockfall protection device that suspends and installs the mesh body on the slope, the first mesh body that is a so-called ring-type net having excellent rockfall energy absorption capability can be utilized. It can cope with large rocks and swarms. On the other hand, since the second net is also suspended together, it is possible to stop small rockfalls that cannot be stopped by the first net. Furthermore, both the functions of the first net and the finer second net can be effectively exhibited. For example, a second mesh body such as a wire mesh is obtained by combining row lines obtained by bending wire rods into a net shape, and the displacement at the time of shock absorption of the ring net that is the first mesh body described above. There is no displacement like the behaviors (1), (2) and (3), the deformation is inferior to the first network, and the strength per unit is also low. Therefore, when the first mesh body having high deformation performance is installed on the mountain side and the second mesh body having low deformation performance is installed on the valley side, the displacement of the second network body due to falling rocks is the displacement surface of the first network body. Because it is displaced through, it will be displaced in a wider range that is in direct contact with the stone. As a result, the second mesh body is deformed immediately after the start of displacement at a load increase rate corresponding to the wire strength, but the load increase rate per unit area is suppressed. Therefore, it becomes possible to suppress the possibility of the breakage of the second net body due to falling rocks, and as a result, more effective performance of the performance of the first net body and the performance of the second net body on the back surface is ensured. can do.

The rock fall protection device according to claim 3,
The second net body is a net body configured by combining wire rods having a shape in which a plurality of mountain shapes are continuous. That is, the second mesh body is made of, for example, a wire mesh, and can be easily configured as a mesh body having a finer mesh than the ring net that is the first mesh body, and is suitable as a combination of ring nets. .

The rock fall protection device according to claim 4 ,
The first net is characterized in that the upper region in a suspended state has a stronger strength than the lower region. According to this configuration, the second net body is relatively expensive in terms of enforcement cost by adjusting the strength of the first net body installed only in the upper region, not in the entire area thereof. The effective construction cost of the first net body can be reduced and the total weight of the first net body to be installed can be reduced. That is, the installation position of the support is adjusted according to the undulation of the slope, and installed so that the impact of the large inclining machine is applied to the upper area of the first mesh body, without reducing the performance of the entire mesh body. The enforcement cost and weight can be reduced.

The rock fall protection device according to claim 5 is:
Each ring-shaped member of the first net body is formed by winding a steel wire,
The strength is adjusted by adjusting the number of windings of the steel wire, the wire thickness, or the ring diameter. The strength adjustment of claim 4 is performed by the number of windings of the steel wire, the wire thickness or the ring diameter. By increasing the number of windings, increasing the wire thickness, and reducing the ring diameter. Strength can be increased.

The rock fall protection device according to claim 6 ,
The rock fall protection device according to any one of claims 1 to 5 , wherein a brake member is attached to the support rope. Thereby, when a strong pulling force is applied to the support rope, the impact can be reduced. That is, in order to make the impact absorbing function of the mesh body more effective, the support column is provided on the natural ground in a state where it can be rotated to the valley side. It turns and a sudden load is applied to the support rope. Therefore, the impact is mitigated by attaching a brake member to the support rope.

  According to the rock fall protection device having the above-described configuration, it is possible to accurately absorb a wide range of rock fall energy from absorption of large energy due to the fall of a large stone to stopping small rock fall. That is, in the so-called curtain-type rockfall protection device, the first net body having excellent rockfall energy absorption capability can be utilized, and it is possible to cope with large rockfalls and cluster rockfalls, A small net of small size can be restrained by the second mesh body with small stitches suspended together.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an overall configuration of a rock fall protection device 10 according to the embodiment, and FIG. 2 shows a state in which the rock fall protection device 10 is installed on a slope as viewed from the side. As shown in the figure, a plurality of support columns 12 are arranged at predetermined heights on the slope and spaced apart from each other at a predetermined interval to form a support column. As shown in FIG. 2, it is attached to a base 14 embedded in a slope ground via a hinge 16, and the column 12 can be rotated at least to the valley side by the hinge 16. .

  A main rope 18 is suspended from the upper end of the column 12 over the entire column. A net is suspended from the main rope 18, and the characteristic feature of the present invention is that two types of nets are used simultaneously as the net. In this embodiment, a so-called ring net is used as the first net and a wire net is used as the second net. As illustrated, the wire mesh 19 and the ring net 20 are respectively suspended from the main rope 18.

  Each support column 12 is provided with a support rope 13 to assist these standing states. In the present embodiment, two holding ropes 13 are stretched from each upper end portion of the support column 12 to a predetermined position on the mountain side of the support column 12 so as to form a predetermined angle. The mountain side end of the support rope 13 is stably fixed to the slope ground by an anchor.

  The ring-type net 20 suspended from the main rope 18 is configured by connecting a plurality of ring-shaped members 21. As shown in FIG. 3, each ring-shaped member includes a plurality of wire rods (5 It is formed by winding several times in the circumferential direction and fastening several places in the circumferential direction by fastening means 21a. The fastening means 21a is, for example, a substantially cylindrical metal fitting having a C-shaped cross section, and after being fitted to the wire bundle through the opening, it is fixed to the wire bundle by a tightening tool. In addition, it is possible to adjust the intensity | strength and energy absorption power of the ring-shaped member 21 by adjusting the number of turns of a wire, or selecting the thickness of a wire. The ring-shaped member 21 can be made of various materials. For example, carbon fiber or aramid fiber can be used in addition to steel.

  In addition, this ring-shaped member 21 is not restricted to the said structure, It can take a various structure. For example, it is possible to adopt a knitted configuration while facing each other when winding the wire, and it is also possible to use a resin as the material.

  In the present embodiment, one ring-shaped member 21 is configured to be connected to four surrounding ring-shaped members. Therefore, as described in the above “Background Art” section, the displacement behavior when absorbing the impact is the net fitting time (until the load is applied to the intersection of the ring-shaped members connected so as to intersect each other ( When the elastic displacement time (above (2)) in which the ring-shaped member is deformed while maintaining the circular shape is exceeded (1)), as shown in FIG. )) Exists. It is also possible to connect with six ring-shaped members around one ring-shaped member 21. 5 (A) and 5 (B) show a part of a six-connected ring net. FIG. 5 (A) is a conceptual diagram of a deformed word, and FIG. 5 (B) is a conceptual diagram of a deformed word. As shown in the figure, the deformed shape is substantially hexagonal.

  The ring-type net 20 has a unique displacement behavior as described above, so it has a high strength and a large deformation range, and has an excellent shock absorption capacity against falling rocks. Has been.

  On the other hand, the wire net 19 as the second net body has a finer stitch than the ring net 20 as can be understood from the figure, and the wire rod such as a steel wire is bent so that the chevron is continuous. These are locked together to form a net having a desired range of spread. In addition, the displacement behavior when subjected to the impact is as follows: (1) the time until the load is applied to the intersection of the row lines bent in a chevron (familiar time of the wire mesh), (2) the row due to the load acting on the intersection The elastic displacement time of the line, (3) the plastic displacement time of the row line due to the load acting on the intersection, and (4) the break of the row line. As described above, the displacement of the ring net 20 described above (1) to (3) does not occur, and the deformation performance is inferior to that of the ring net 20.

  In addition, what is characteristic in the present embodiment is that the wire mesh 19 extends from the main rope 19 to the horizontal ground portion 100 which is the lowest part of the slope, but the ring net 20 is only halfway. It is not covered. That is, the ring-type net 20 is configured to be shorter in the vertical direction than the metal net 19. Thereby, the construction cost of the ring-type net 20 having a relatively high construction cost can be suppressed, and the weight of the ring-type net 20 that is heavier than the wire net 19 can be reduced. The weight burden can be minimized.

  As described above, even if the cover range in the vertical direction of the ring-type net 20 is limited to only the upper part, the impact absorbing action against falling rocks does not cause a significant decrease. That is, the falling trajectory of the falling rock varies depending on the uneven shape of the slope surface and the starting point of the falling rock, but when falling rock enters the mesh body, first, in the portion where the ring net 20 exists, that is, in the upper region. It will collide. The rock fall energy is greatly attenuated in the upper region where the ring net 20 is installed, and falls down below the slope. Therefore, in the lower region, the mesh body does not receive such a large impact, and the falling rocks finally gather on the horizontal ground portion 100 at the bottom of the slope.

  In addition, for example, in the uneven state of the slope as shown in FIG. 2, the slope has a gentle slope shape with relatively no unevenness in the vicinity of the horizontal ground portion 100, but in the region where the column 12 is installed. There is a situation in which a protruding portion exists like the point P1 or the point P2. In such a situation, the falling rock may bounce off the slope at the point P1 or point P2, and even in such a case, the rock that has jumped on the ring net 20 in the upper area It receives and absorbs that great energy.

  FIG. 6 shows a situation where the jumped stone is received by the ring net 20. As shown in the figure, the stone 200 collides with the ring net 20 at an angle close to a right angle from the front, and the ring net 20 accurately absorbs the falling rock energy.

  FIG. 7 more specifically shows a state in which the ring-type net subjected to the falling rock is greatly deformed by performing the above-described displacement behavior (the wire mesh 19 is not shown). As shown in the figure, the ring net 20 is excellent in strength and deformability, can absorb a large amount of rock fall energy, and the speed of rock fall is greatly reduced. From the state shown in the figure, the falling rock 20 falls further downward, but since the falling rock energy is once attenuated, it is reliably restrained by the wire mesh 19 existing below, and the horizontal ground part which is the lowest part of the slope. Collected in 100.

  Next, still another characteristic item of the present embodiment will be described. As described above, in the present embodiment, only the upper region of the mesh has a double structure of the wire mesh 19 and the ring net 20, but the arrangement of the wire mesh 19 and the ring net 20 is on the valley side. A wire net 19 and a ring net 20 on the mountain side are provided. That is, it is the arrangement in which the metal mesh 19 exists on the back side with respect to the falling rock. According to this arrangement, both the functions of the ring net 20 and the finer metal mesh 19 can be effectively exhibited.

  FIG. 8 shows the displacement behavior of both when a rockfall impact occurs when the wire mesh 19 is arranged on the valley side and the ring net 20 is arranged on the mountain side. As shown in the figure, the rockfall first collides with the ring net 20 ( (A)), the displacement of the metal mesh 19 due to falling rocks is displaced via the displacement surface of the ring net 20 (displacement range L11 in the figure). Therefore, the displacement range (L12) of the wire mesh 19 is displaced in a wider range than when a stone collides directly. As a result, the wire mesh 19 is deformed at a load increase rate corresponding to the wire strength immediately after the start of displacement, but the load increase rate per unit area is suppressed. Therefore, it becomes possible to suppress the possibility of the breakage of the wire net due to falling rocks, and as a result, more effective display of the performance of the ring net 20 and the performance of the back side metal mesh 19 can be ensured.

  Next, although not shown in the drawing, as another embodiment, it is possible to adjust the strength for each region in the installed state of the ring net 20 as shown in FIG. For example, the upper region in the suspended state can be configured to be stronger than the lower region. For example, in the configuration of the ring-shaped member 21 as shown in FIG. 3, the strength can be adjusted by increasing the number of windings of the steel wire to increase the strength, The strength can be increased by reducing the ring diameter.

  In this manner, the ring net 20 installed only in the upper region of the mesh body is further adjusted in strength, thereby reducing the construction cost of the relatively expensive ring net 20 and the ring type. The total weight of the net 20 can be reduced. That is, it is preferable to increase the strength of a portion that will receive a large impact when the falling orbit of the falling rock is predicted from the surface irregularity shape of the slope. In addition, if the installation position of the support column 12 is adjusted according to the undulation of the slope and can be adjusted so that the impact of a large falling rock is applied to the upper area of the ring net 20, the upper area is set to the lower area. Can be set to increase the strength. As a result, the construction cost and weight can be reduced without degrading the performance of the entire mesh body due to the double structure of the wire net 19 and the ring net 20.

  In addition, it is preferable to attach a brake device to the support rope 13 as a reinforcement structure of the part which supports the mesh body which consists of the metal net | network 19 and the ring type net | network 20. FIG. This brake device is sufficient with a known technique. For example, when a strong pulling force is applied to the support rope 13 by inserting the support rope through a looped tube wound and tightening both ends of the looped tube. The pulling energy is absorbed by the contraction of the looped tube. The looped tube is preferably a steel tube, but can be made of other metal materials or plastic materials.

  With this configuration, the impact applied to the support rope 13 that supports the upright state of the support column 12 that can turn to the valley side can be reduced, and the support function of the support column can be complemented. It can be accurate.

  The present invention is not limited to the configuration of the above embodiment, and various modifications are possible within the scope of the gist of the invention. For example, when only the upper part of the mesh body has a double structure of a wire mesh and a ring net, the area ratio of the double structure part to the whole can be changed and adjusted as appropriate. Moreover, although the example which engages what bent the wire rod in the mountain shape was shown, the wire mesh is not restricted to this, The wire mesh which has a finer structure than a ring type net | network is applicable.

It is explanatory drawing which shows the whole structure of the rock fall protection apparatus which concerns on embodiment of this invention. It is shape explanatory drawing seen from the horizontal direction of the state which installed the rock fall protection apparatus shown in FIG. 1 on the slope. It is a schematic perspective view which shows the structure of the ring-shaped member which comprises a ring type net | network. It is explanatory drawing which shows the deformation | transformation body of a ring-shaped member when an impact is added to a ring type net | network. (A) And (B) shows the ring-type net block diagram of the form where six ring-shaped members are connected to one ring-shaped member, and a deformed body of the ring-shaped member when an impact is applied. It is explanatory drawing. It is state explanatory drawing when a falling rock collides with a net-like body. It is explanatory drawing which shows the specific behavior of a ring-type net when a falling rock collides with a net-like body. It is explanatory drawing which shows the displacement behavior at the time of the impact absorption of the double structure part of a metal-mesh (valley side) and a ring-type net | network (mountain side).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Falling rock protective device 12 Support | pillar 13 Support rope 14 Base 18 Main measure rope 19 Wire net 20 Ring type net 21 Ring-shaped member

Claims (6)

A strut row having a plurality of struts arranged on a slope at a predetermined interval and fixed to a natural ground so as to be rotatable at least on the valley side, and suspended between each of the struts and the mountain side of the natural ground And a support rope that maintains the standing state of each support column, a main measure rope suspended from the support column, and an upper edge portion is suspended by the main measure rope, and is grounded at the lowest position of the slope. A fixed mesh,
In rock fall protection equipment including
The network is
A first net body configured in a net shape by connecting a plurality of ring-shaped members with a plurality of adjacent ring-shaped members,
A second net having a finer stitch than the first net suspended from the main rope so as to overlap the first net;
The equipped Rutotomoni,
The second net is provided in the entire area from the main rope to the lower final position of the slope,
The first rock body is provided with a falling rock protection device that is provided not in the whole area but in a part of a predetermined length downward from the main rope . A strut row having a plurality of struts arranged on a slope at a predetermined interval and fixed to a natural ground so as to be rotatable at least on the valley side, and suspended between each of the struts and the mountain side of the natural ground And a support rope that maintains the standing state of each support column, a main measure rope suspended from the support column, and an upper edge portion is suspended by the main measure rope, and is grounded at the lowest position of the slope. A fixed mesh,
In rock fall protection equipment including
The network is
A first net body configured in a net shape by connecting a plurality of ring-shaped members with a plurality of adjacent ring-shaped members,
A second net having a finer stitch than the first net suspended from the main rope so as to overlap the first net;
With
The falling rock protection device according to claim 1, wherein the first net is disposed on a mountain side and the second net is disposed on a valley side.   3. The rock fall protection device according to claim 1, wherein the second net body is a net body configured by combining wire rods having a mountain-shaped continuous shape into a net shape. 4. The rock fall protection according to any one of claims 1 to 3 , wherein the first net has a structure in which the upper region in a suspended state is stronger than the lower region. apparatus. Each ring-shaped member of the first net body is formed by winding a steel wire,
The rock fall protection device according to any one of claims 1 to 4 , wherein the strength is adjusted by adjusting the number of windings of the steel wire, the wire thickness, or the ring diameter. The rock fall protection device according to any one of claims 1 to 5 , wherein a brake member is attached to the support rope.

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