Guard fence support structure

Abstract

To provide a support structure used in a guard fence for capturing falling rocks, etc., which is easy to maintain and has high impact energy absorption performance.SOLUTION: A support structure of a guard fence 10 comprises a plurality of support bodies 38 installed at predetermined intervals on a base 32 constructed on the ground, and on which a net 12 is stretched. A support member 40 is installed on a valley side and / or mountain side of the ground slope of the support bodies, and is a rod-shaped body with one end 40a connected to the base and the other end 40b connected to the support bodies, and has a curved and / or bent portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a support structure for a guardrail, and more particularly to a support structure used for a guardrail that captures falling rocks and the like on a slope to prevent disasters. [Background technology]

[0002] Traditionally, protective fences have been installed on mountain slopes to protect adjacent roads, railways, and homes from natural disasters such as landslides, falling rocks, and avalanches. In Japan, which is particularly prone to damage from earthquakes and heavy rains, it is important to take disaster prevention measures by installing protective fences on slopes.

[0003] A guardrail is generally constructed by suspending ropes or nets between multiple posts erected at intervals on a slope. When such a guardrail receives an impact load caused by falling rocks or the like, the impact is absorbed by the extension of the ropes or nets.

[0004] For example, the protective fence described in Patent Document 1 is formed by stretching a net between multiple posts erected on a ground slope, and each post is made of a highly rigid columnar body, and is erected by embedding the base of this columnar body into the ground. When an impact force acts on this protective fence due to a rockfall or the like, the impact energy is absorbed by the stretching of the net without deforming the posts.

[0005] The protective fence described in Patent Document 2 is formed by stretching a net between multiple posts erected on a ground slope, and each post is configured by a pillar-shaped post body erected via a hinge on a base constructed on the ground so that it can tilt. The post body is prevented from tilting toward the valley by a tie rope stretched from the upper end of the post body toward the slope of the mountain.

[0006] In the protective fence described in Patent Document 2, the support pillars are installed on the base via hinges so that they can be tilted as described above, and when an impact force acts on the protective fence due to a rockfall or the like, the net is extended to absorb the impact energy, and the support pillars are tilted via the hinges, thereby extending the stay ropes supporting the support pillars and absorbing the impact energy. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-117361 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-105721 Summary of the Invention [Problem to be solved by the invention]

[0008] In the guardrail fence described in Patent Document 2, the support poles are easier to replace than in fences where the poles are embedded in the ground, and maintenance work is easier if the support poles are damaged. However, while conventional guardrail fences can absorb impact energy by deforming the net or tie ropes, the net and rope are components that are easily stretched and deformed, and therefore have low impact energy absorption performance. Therefore, there has been a demand for a guardrail structure that makes maintenance work easier and enables improved impact energy absorption performance.

[0009] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a support structure used in protective fences that capture falling rocks, etc., that is easy to maintain and has high impact energy absorption performance. [Means for solving the problem]

[0010] In order to achieve the above object, the support structure of the protective fence described in claim 1 comprises: A support structure for a protective fence includes a plurality of support poles installed at predetermined intervals on a base constructed on the ground, and on which a net or rope is stretched, The support member is a rod-shaped body that is installed on the valley side and / or mountain side of the ground slope of the support pillar body, one end of which is connected to the base and the other end of which is connected to the support pillar body, and that has a curved and / or bent portion.

[0011] With this configuration, if the net of the protective fence is hit by a rockfall or the like and an impact load acts on the support post main body, the support members connected to the support post main body are rod-shaped bodies with curved and / or bent portions, and so deformation occurs at the curved and bent portions. That is, compared to when the support members are configured as straight rod-shaped bodies, the stress caused by the impact is concentrated at the curved and bent portions, making them more likely to bend on the convex side of the curve or bend. As a result, the support members crash at these curved and bent portions, allowing them to absorb the impact load.

[0012] For example, if a support member is installed on the valley side of the support body and an impact load from a rockfall acts on the support body, tilting it toward the valley side of the ground slope, a concentrated load will act on the curved and / or bent parts of the support member, causing the support member to buckle from the point of application of this concentrated load.

[0013] Furthermore, if the support members are installed on the mountain side of the ground slope relative to the support pillar body, tilting the support pillar body toward the valley side will cause an elongation force to act on the support members. This causes the curved and / or bent sections to elongate, making it possible to absorb the impact energy of falling rocks. In this way, providing the support pillar body with easily deformable support members can improve the impact energy absorption performance of the guardrail.

[0014] Furthermore, since the support body is installed on a base, replacement is easy, and maintenance work is easy if the support body is damaged.

[0015] The invention described in claim 2 is the support structure described in claim 1, The support column body is tiltably mounted on the base via a hinge.

[0016] With this configuration, when a falling rock hits the support pole body directly, the support pole body can be actively tilted to deflect the rock toward the net, preventing damage to the support pole body. This eliminates the need to replace the support pole body, reducing the time and cost required for maintenance of the protective fence. In addition, actively tilting the support pole body encourages deformation of the support member, improving the energy absorption performance of the support member.

[0017] The invention described in claim 3 is the support structure described in claim 1 or 2, The support member is formed in a curved or bent shape that is convex in a direction away from the support body and the base, one end is connected to the center of the support member in the longitudinal direction, and the other end is connected to a part of the support body that is lower than the connection part with the support member, and is characterized in that it is equipped with a deformation control member that acts in a direction to suppress bending or curving in the event that bending or curving occurs in the support member.

[0018] According to this configuration, when an impact is applied to the support body and the support body tilts toward the support member, the support member located between the support body and the base bends and flexes in a direction away from the support body and the base. The deformation-restricting member acts to suppress this bending and flexing of the support member. That is, at the beginning of the tilting movement of the support body, the support member bends and flexes, thereby mitigating the impact in the direction that tilts the support body. When the support body has tilted to a certain extent, it is possible to suppress that tilt, and by suppressing tilting, it is possible to prevent the next falling rock from easily passing through the net stretched around the support.

[0019] The invention described in claim 4 is the support structure described in claim 1 or 2, The support member is characterized in that it is formed in a curved or bent shape that is convex in a direction approaching the support body and the base.

[0020] With this configuration, when an impact is applied to the support body and the support body tilts toward the support member, the support member located between the support body and the base bends and flexes toward the support body and the base. Therefore, the support member is sandwiched between the support body and the base at a position below the support body. The presence of this support member serves to prevent the support body from tilting. That is, at the beginning of the tilting movement of the support body, the support member bends and flexes to absorb the impact in the direction of tilting the support body. Finally, the support member is sandwiched between the support member and the base, preventing the support body from tilting. This allows for both the absorption of impact from falling rocks and the prevention of tilting of the support body.

[0021] The invention described in claim 5 is the support structure described in claim 1 or 2, The support member is characterized in that both ends thereof are connected to the base and the support body via hinges.

[0022] According to this configuration, when a collision load is transmitted from the support pillar body to the support member, the support member can rotate relative to the support pillar body and the base, which prevents the load from concentrating on the connecting portion and prevents damage to the connecting portion of the support member, and enables accurate bending of the curved portion and / or bent portion, improving the energy absorption performance due to bending.

[0023] The invention described in claim 6 is the support structure described in claim 1 or 2, The support members are characterized in that a plurality of them are provided on at least the same side of the ground slope valley side or the ground slope mountain side relative to the support pillar body.

[0024] According to this configuration, multiple support members provided on the same side of the support pillar body can be subjected to buckling deformation or elongation deformation, thereby improving the efficiency of absorbing impact energy.

[0025] The invention described in claim 7 is the support structure described in claim 6, The plurality of support members provided on the same side are connected to the support column body at the same height position, and the center portions in the length direction are connected to each other by a connecting member, The connecting member is characterized in that when a force acts in the direction of extension, it applies a biasing force that counters the force.

[0026] According to this configuration, when the support pillar body tilts, the impact load acting on the multiple support members via the connecting member can be made uniform, allowing the multiple support members to deform appropriately.

[0027] The invention described in claim 8 is the support structure described in claim 6, The plurality of support members provided on the same side are characterized in that they are configured to have different buckling strengths.

[0028] With this configuration, it is possible to sequentially deform multiple support members connected to the support body, thereby absorbing impact energy in stages, and by dispersing the instantaneous impact, higher impact resistance can be ensured. [Effects of the Invention]

[0029] According to the guardrail fence support structure of the present invention, if the guardrail net is hit by a rockfall or the like, causing an impact load to act on the support main body and tilting the support main body, the support members connected to the support main body can be deformed to absorb the impact load. The support members are rod-shaped bodies with curved and / or bent portions, and since stress due to an impact is concentrated at the curved or bent portions, they are prone to bending on the convex side of the curve or bend. The support members deform at these curved or bent portions, thereby absorbing the impact load. In this way, providing the support main body with easily deformable support members can improve the impact energy absorption performance of the guardrail fence. Furthermore, because the support main body is installed on a base, maintenance work is easy if the support main body is damaged. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a perspective view of a protective fence using a support structure according to one embodiment of the present invention. [Figure 2] FIG. 2 is a side view of the protective fence shown in FIG. [Figure 3] FIG. [Figure 4] FIG. 2 is a side view showing the main part of the support structure. [Figure 5] FIG. 5 is a cross-sectional view taken along line AA in FIG. [Figure 6A] FIG. 10 is a side view illustrating the operation of the protective fence. [Figure 6B] FIG. 10 is a side view illustrating the operation of the protective fence. [Figure 7] FIG. 10 is a side view showing a modified example of the support structure. [Figure 8] FIG. 10 is a side view showing a modified example of the support structure. [Figure 9] FIG. 10 is a side view showing another embodiment of the support structure. [Figure 10] FIG. 6 is a cross-sectional view similar to FIG. 5, showing another embodiment of the support structure. DETAILED DESCRIPTION OF THE INVENTION

[0031] A protective fence 10 using a support structure according to one embodiment of the present invention will be described in detail using Figures 1 to 5. Note that the figures used in the following description are schematic diagrams and do not precisely depict the dimensions of each component. The protective fence 10 is installed on mountain slopes and the like to protect adjacent roads, railways, and residences from natural disasters such as falling rocks, landslides, and avalanches, and prevents disasters by catching fallen earth and rocks. As shown in Figure 1, the protective fence 10 includes multiple support posts 30 and a protective net 12 stretched between the support posts 30. The net 12 catches falling rocks, falling earth, and the like, preventing damage. Note that the protective fence 10 may have a structure in which multiple ropes are stretched between the support posts 30 instead of the net 12. The height of the support posts 30 above ground is, for example, about 2m to 5m, and the spacing between the support posts 30 is, for example, 3m to 5m, or in some cases about 5m to 10m, and these can be selected appropriately depending on the size of the ground slope S on which the protective fence 10 is to be installed and the situation.

[0032] The protective fence 10 of this embodiment comprises multiple posts 30-1 to 30-4, a net 12, an upper support rope 14, a holding rope 16, an auxiliary rope 18, and buffer means 20, 22, and 24. While FIG. 1 shows four posts 30-1 to 30-4 as an example, the number of posts 30 is not limited to this and may be two or more. The multiple posts 30 are installed on the ground at predetermined intervals to tension the net 12, forming a single row of posts. Each post 30 comprises a base 32, a hinge 34 for a post body 38, the post body 38, and a support member 40. Each of the components constituting the protective fence 10 will be described in detail below.

[0033] The net 12 is a mesh of steel wires (e.g., high-tensile hard steel wires or wires made by twisting multiple high-tensile hard steel wires). In the illustrated example, the net 12 is a ring-shaped net with ring-shaped meshes. In the ring-shaped net, the diameter of each ring forming the mesh can be, for example, 300 to 400 mm. Each ring is formed, for example, by winding steel wire once or multiple times and fastening it at several points around the circumference with fastening means. The fastening means is, for example, a substantially cylindrical metal fitting with a C-shaped cross section. After fitting the wire bundle through its open portion, it is fixed to the wire bundle with a tightening tool. The net 12 may also be, for example, a diamond-shaped wire mesh with diamond-shaped meshes. The lower end of the net 12 extends from the support posts 30 to the mountain side of the ground slope S and is fixed to the ground with anchor bolts 54. In this embodiment, the net 12 is pressed against and fixed to the ground slope S by plates 55 attached to the heads of the anchor bolts 54. The plates 55 are fixed to the heads of the anchor bolts 54 using bolts 56. Note that the lower ends of the net 12 do not have to extend to the mountain side of the ground slope S, and may instead extend to the lower support ropes 15 suspended below each support pillar body 38.

[0034] The upper support ropes 14 are stretched across the upper ends of the column rows. As shown in Figures 1 and 2, the upper support ropes 14 are stretched from the first anchors 28A fixed to the ground slope S, through the tops of the columns 30-1 to 30-4, and to the second anchors 28B. The upper support ropes 14 are located on the upper side of the net 12.

[0035] Of the multiple columns 30-1 to 30-4 that make up the column row, the inner columns 30-2 and 30-3, excluding the columns 30-1 and 30-4 at both ends, are equipped with holding ropes 16 that extend from the top of the columns to anchors 28 that are fixed to the ground on the mountainside of the slope. In this embodiment, two holding ropes 16 are provided for each column 30-2 and 30-3. These holding ropes 16 allow the columns 30-2 and 30-3 to be stably erected and enable adjustment of the tilting movement of the columns 30-2 and 30-3. Although not shown, a structure in which holding ropes 16 are provided for the columns 30-1 and 30-4 at both ends may also be adopted.

[0036] The auxiliary ropes 18 are laid horizontally at a predetermined height between at least two of the multiple pillars 30-1 to 30-4. In this embodiment, three auxiliary ropes 18 are laid horizontally at intervals in the vertical direction between the two pillars 30-1 and 30-4 located at both ends of the pillar row. Both ends of each auxiliary rope 18 are fixed by fixing devices (not shown) provided on each of the two pillars 30-1 and 30-4, and the auxiliary ropes 18 are laid across with a constant tension.

[0037] The upper support rope 14, the holding rope 16, and the auxiliary rope 18 are provided with shock absorbers 20, 22, and 24, respectively. The shock absorbers 20, 22, and 24 absorb sudden impact forces during rockfall collisions and prevent breakage of the ropes 14, 16, and 18. Figure 3 is a perspective view showing the shock absorber 24 located near the end of the auxiliary rope 18. The shock absorber 24 is constructed by first inserting the auxiliary rope 18 through a metal fastening member 25 having a hole 25a through which two auxiliary ropes 18 can pass. After winding the auxiliary rope 14 once into a loop, the auxiliary rope 14 is again inserted through the hole 17a from the same direction and the fastening member 25 is crimped to secure it to the inserted auxiliary rope 18. This allows the auxiliary ropes 18 to be in frictional contact with each other within the hole 25a. The buffer means 20 and 22 provided on the upper support rope 14 and the holding rope 16, respectively, also have the same structure as the buffer means 24 shown in FIG.

[0038] 1, 2, and 4, the support pillar 30 has a support structure including a base 32 constructed on the ground, a support pillar body 38 installed on the base 30 via a hinge 34, a support member 40, and a deformation restriction member 46. Note that the deformation restriction member 46 is not shown in FIG. 1.

[0039] The base 32 serves as the foundation for the support pillar 30. In this embodiment, the base 32 is made of a concrete foundation built on the ground, and is built for each support pillar body 38. By constructing the base 32 from a solid concrete foundation in this way, it is possible to stabilize the base 32 on which the support pillar body 38 is installed. In this embodiment, the base 32 is firmly fixed to the ground using at least one anchor bolt 50.

[0040] The pillar body 38 is a columnar body made of a highly rigid material such as steel. The pillar body 38 is installed via hinges 34 so that it can tilt toward the valley side and the mountain side of the ground slope S. In this embodiment, the pillar body 38 is formed in a cylindrical shape with a circular cross section, but the cross-sectional shape is not limited to this and may be a polygonal shape such as a square, or may be an H-shaped steel. The length of the pillar body 38 can be, for example, 1.5 m to 3.5 m, and preferably 2 m to 3 m.

[0041] The hinge 34 provided between the base 32 and the support main body 38 includes a fixed plate 34a that is fixed to the base 32 and stands upright from the base 32, and a shaft member 34b attached to the fixed plate 34a. The fixed plates 34a are arranged in pairs to sandwich the circumferential surface of the support main body 38. The shaft member 34b passes through the support main body 38 and the pair of fixed plates 34a. This allows the support main body 38 to be tiltable on the base 32 around the shaft member 34b. The support main body 38, which is configured to be tiltable by the hinge 34, is held in an upright position by the upper support rope 14 and the holding rope 16, and is supported by the support member 40.

[0042] The support member 40 is a rod-shaped body installed on the valley side and / or mountain side of the ground slope of the support pillar body 38, and has a curved portion and / or a bent portion. In this embodiment, an example is shown in which the support member 40 is installed on the valley side of the support pillar body 38, and this support member 40 is formed in a curved shape that convexly extends away from the support pillar body 38 and the base 32. In this embodiment, as shown in FIG. 1 , a support member 40 is provided on each support pillar body 38. The support member 40 is preferably formed of a material with lower rigidity than the support pillar body 38, such as an aluminum alloy or a hard resin material. In this embodiment, as an example, the support member 40 is configured as a curved, hollow circular tube made of an aluminum alloy. However, it may also be a hollow column material with a square cross section. The support member 40 may be a hollow tube with an outer diameter of 50 mm to 70 mm, for example, and a thickness of 3 mm to 5 mm, for example. The support member 40 may also be a solid rod-shaped body.

[0043] One end of the support member 40 is connected to the base 32, and the other end is connected to the support column main body 38. As shown in Fig. 3, in this embodiment, both ends 40a, 40b of the support member 40 are connected to the base 32 and the support column main body 38 via hinges 42, 44. In the following description, the end of the support member 40 connected to the base 32 will also be referred to as the first end 40a, and the end connected to the support column main body 38 will also be referred to as the second end 40b. The hinge 42 interposed between the first end 40a of the support member 40 and the base 32 will also be referred to as the first hinge 42, and the hinge 44 interposed between the second end 40b and the support column main body 38 will also be referred to as the second hinge 44.

[0044] The first hinge 42 includes a pair of plate-like portions 42a protruding from the base 32 and a shaft portion 42b serving as a rotation axis. The pair of plate-like portions 42a are arranged to face each other with the first end portion 40a of the support member 40 sandwiched therebetween. The shaft portion 42b is composed of a shaft member that penetrates the pair of plate-like portions 42a and the first end portion 40a.

[0045] The second hinge 44 includes a base 44a joined to the circumferential surface of the support pillar main body 38, a pair of plate-like portions 44b protruding from the base 44a, and a shaft portion 44c serving as a rotation axis. The base 44a is plate-shaped and has an arc-shaped cross section that surrounds the circumferential surface of the support pillar main body 38. The pair of plate-like portions 44b are fixed to the base 44a and are arranged substantially parallel to each other and facing each other with the second end portion 40b of the support member 40 sandwiched therebetween. The shaft portion 44c is composed of a shaft member that penetrates the pair of plate-like portions 44b and the second end portion 40b. As shown in FIGS. 4 and 5, the first hinge 42 and the second hinge 44 are installed such that the shaft portions 42b, 44c serving as the rotation axis are parallel to the shaft portion 34b of the hinge 34 for the support pillar main body 38.

[0046] Distance D1 from the top surface of the base 32 to the connecting portion between the pillar body 38 and the support member 40 (in this embodiment, the distance to the shaft 44c of the second hinge 44) is set to 1 m or less. Distance D2 from the pillar body 38 to the connecting portion between the base 32 and the support member 40 (in this embodiment, the distance to the shaft 42b of the first hinge 42) is set to be smaller than distance D1, and can be set to, for example, 50 cm. Note that these distances D1 and D2 can be set appropriately according to the height of the pillar body 38, etc.

[0047] A deformation restriction member 46 is attached to the support member 40. One end of the deformation restriction member 46 is connected to the longitudinal center of the support member 40, and the other end is connected to a portion of the support column body 38 below the connection portion with the support member 40. The deformation restriction member 46 applies a force in a direction that suppresses bending or flexing of the support member 40 when the support member 40 is bent or flexed. The deformation restriction member 46 may be, for example, a wire rope or a spring member. In this embodiment, a wire rope is used as an example. When a tensile force is applied to the deformation restriction member 46, the deformation restriction member 46 applies a force in a contracting direction, thereby restricting deformation of the support member 40. The deformation restriction member 46 is optional, and the structure may not include the deformation restriction member 46.

[0048] Next, the operation of the protective fence 10 equipped with the support structure of this embodiment will be described. Fig. 6A is a side view of the protective fence 10, showing a state in which a falling rock 70 is received by the net 12 suspended between the support pole bodies 38 at an upper position away from the ground. When the net 12 receives the falling rock 70 and the support pole body 38 receives an impact load of a predetermined value or greater, the support pole body 38 tilts toward the valley side of the ground slope S due to the hinge structure provided at its lower end, and a compressive load acts on the support member 40 connected to the support pole body 38. Compared to when the support member 40 is configured as a straight rod, stress due to the impact load is concentrated at the curved portion, making it more likely to bend convexly. The support member 40 buckles at this curved portion, absorbing the impact energy.

[0049] In this embodiment, the pillar body 38 is tiltably installed on the base 32 via the hinges 34, so that the load received by the pillar body 38 can be directly applied to the support members 40. This promotes deformation of the support members 40, allowing for active absorption of impact energy. Furthermore, in a pillar structure provided with hinges 34, the energy absorption performance of the pillar body 38 itself can be reduced compared to a pillar structure in which the pillar body is fixedly installed, and impact loads received by the pillar body 38 can be effectively transmitted to the support members 40 and ropes 14, 16, thereby preventing damage to the pillar body 38.

[0050] Furthermore, because hinges 42, 44 are interposed at the connection parts between the support member 40, the support pillar main body 38, and the base 32, when a collision load is transmitted from the support pillar main body 38 to the support member 40, the support member 40 can rotate relative to the support pillar main body 38 and the base 32, preventing the load from concentrating on the connection parts and preventing damage to the connection parts of the support member 40. This allows the curved parts of the support member 40 to be deformed appropriately, improving energy absorption performance.

[0051] Furthermore, in the support structure of this embodiment, deformation of the support member 40 can be restricted by the deformation restriction member 46 attached to the support member 40. Specifically, when the support member 40 buckles and bends away from the support body 38 and the base 32, a tensile force acts on the deformation restriction member 46, and the deformation restriction member 46 accordingly applies a force in a direction that restricts the bending of the support member 40. That is, in the early stage of the tilting of the support body 38, the support member 40 deforms to absorb impact energy, and as the tilting of the support body 38 progresses, the deformation restriction member 46 restricts the deformation of the support member 40, thereby restricting the tilting of the support body 38. This prevents the next falling rock 70 from easily passing through the net 12 stretched around the support body 38 when the support body 38 is completely tilted.

[0052] Next, the operation of the protective fence 10 of this embodiment will be described using Figure 6B. Figure 6B shows a state in which a falling rock 70 is received by the net 12 near the lower end of the support pole body 38. In such a case, an impact load acts on the support pole body 38 via the net 12, causing the support pole body to tilt toward the mountain side of the ground slope S. At this time, a force acts on the support member 40 in the direction of extension. As a result, the curved portion of the support member 40 undergoes extension deformation, absorbing the impact energy of the falling rock 70. Since the extension of the support member 40 stops, tilting of the support pole body 38 is suppressed, and the deformation of the support member 40 can be used to design the support pole body 38 to allow tilting within a predetermined range.

[0053] Furthermore, with the protective fence 10 of this embodiment, if a falling rock 70 hits the support post main body 38 directly, the support post main body 38 tilts via the hinge 34, allowing the hitting rock 70 to escape toward the net 12, thereby providing a high impact absorption effect. This prevents damage to the support post main body 38 and eliminates the need for replacement work due to damage, thereby reducing the time and cost required for maintenance work on the protective fence 10.

[0054] Next, a modified example of the support structure described above will be described. Fig. 7 is a side view showing a modified example of the support structure. In this modified example, the support member 40 is formed in a bent shape that is convex in the direction away from the support main body 38. In this way, the support member 40 may be a rod-like body having a bent portion, or may be a rod-like body having a bent portion as well as a curved portion.

[0055] FIG. 8 is a side view showing another modified example of the support structure. In this modified example, the support member 40-1 is curved so as to convex toward the support main body 38 and the base 32. In the support structure according to this modified example, when an impact load acts on the support main body 38 and the support member 40 tilts toward the support member 40, the support member 40 bends toward the support main body 38 and the base 32. As a result, the support member 40 is sandwiched between the support member 40 and the base 32 below the support main body 38, and the presence of the support member 40 serves to restrict the tilting of the support main body 38. That is, at the beginning of the tilting movement of the support main body 38, the support member 40 deforms to absorb the impact force in the direction of tilting the support main body 38. Finally, the support member 40 is sandwiched between the support main body 38 and the base 32, thereby preventing the support main body 38 from tilting. In this way, it is possible to achieve both the effects of absorbing impact and restricting tilting of the support main body 38. As shown by the solid and virtual lines in Figure 8, the support member 40 may have a structure in which, for one support main body 38, a first support member 40-1 that is convex toward the support main body 38 and a second support member 40-2 that is convex away from the support main body 38 are provided.

[0056] FIG. 9 is a side view showing another embodiment of the pillar structure. In this embodiment, support members 40-1 and 40-2 are attached to one pillar body 38 on both the valley side and the mountain side of the ground slope. The support member 40-1 installed on the valley side is connected to the pillar body 38 and the base 32 via a first hinge 42-1 and a second hinge 44-1, and the support member 40-2 installed on the mountain side is connected to the pillar body 38 and the base 32 via a first hinge 42-2 and a second hinge 44-2. The structures of the first hinges 42-1 and 42-2 and the second hinges 44-1 and 44-2 are similar to those of the first hinge 42 and the second hinge 44 described using FIGS. 4 and 5, so detailed description will be omitted. As in this embodiment, by providing support members 40-1 and 40-2 on both the valley side and the mountain side, it is possible to improve the impact energy absorption performance. Furthermore, even if a falling rock hits support member 40-2 installed on the mountain side, it is possible to absorb the impact energy by deforming support member 40-1 installed on the valley side.

[0057] In the embodiment shown in Figure 9, each support member 40-1, 40-2 has a curved portion that is convex in a direction away from the support body 38 and the base 32, but instead, it may have a shape that is convex in a direction approaching the support body 38 and the base 32, or one may have a shape that is convex in a direction away from the support body 38 and the base 32 and the other may have a shape that is convex in a direction approaching the support body 38 and the base 32.

[0058] Fig. 10 is a cross-sectional view similar to Fig. 5 showing another embodiment of the pillar structure. In this embodiment, two support members 40A, 40B are provided for one pillar body 38 on the valley side of the ground slope of the pillar body 38. In this way, the structure may be such that two or more support members 40 are provided on the same side of the ground slope, either the valley side or the mountain side.

[0059] In this embodiment, the two support members 40A, 40B are connected to the support column main body 38 at the same height via second hinges 44. The center portions of the support members 40A, 40B in the longitudinal direction are connected to each other by a connecting member 48. The connecting member 48 is configured to apply a biasing force that counteracts a force acting in the extension direction. For example, a wire rope or a spring member can be used as such connecting member 48, and in this embodiment, a wire rope is used.

[0060] 10, multiple support members 40A, 40B provided on the same side of the support pillar main body 38 can be subjected to buckling or elongation deformation, thereby improving the efficiency of impact energy absorption. Furthermore, when the support pillar main body 38 tilts, the impact load acting on the multiple support members 40A, 40B can be equalized via the connecting member 48, allowing the multiple support members 40A, 40B to deform appropriately.

[0061] The multiple support members 40A, 40B provided on the same side of the support body 38 may be configured to have different buckling strengths. For example, different buckling strengths can be achieved by changing the materials of the support members 40A, 40B (e.g., making one from an aluminum alloy and the other from a resin), or by changing the curvature or bending rate of each support member. When the buckling strengths are different, the multiple support members connected to the support body can be deformed sequentially to absorb impact energy in stages. This allows the support body 38 to tilt in stages, thereby mitigating the impact load acting on the lower end of the support body 38 when a rock falls and preventing damage to the support body 38.

[0062] As shown in the above-described embodiments and modifications, the support member 40 may be a rod-shaped body having a curved portion and / or a bent portion, and the direction in which the curved portion and / or bent portion is convex may be a direction away from or a direction approaching the support main body 38. Furthermore, the support member 40 may be structured so that at least one support member 40 is installed on at least one of the valley side and the mountain side of the support main body 38.

[0063] The present invention is not limited to the above-described embodiment and modifications, and various modifications are possible without departing from the spirit of the invention.

[0064] For example, the support column body 38 may be fixed to the base 32 without the hinge 34 . [Explanation of symbols]

[0065] 10 Protective fence 12 Net 14 Upper support rope 16 Retaining rope 20,22,24 Buffering means 30 pillars 32 Foundation 34 Hinge 38 Support body 40 Support member 42 First Hinge 44 Second hinge 46 Deformation control member 48 Connecting member S ground slope

Claims

1. A support structure for a protective fence includes a plurality of support poles installed at predetermined intervals on a base constructed on the ground, and on which a net or rope is stretched, A pillar structure characterized by comprising a support member, which is a rod-shaped body having a curved and / or bent portion, installed on the valley side and / or mountain side of the ground slope of the pillar body, one end connected to the base and the other end connected to the pillar body.

2. The support structure according to claim 1 , wherein the support body is tiltably installed on the base via a hinge.

3. The support member is formed in a curved or bent shape that convexly extends away from the support body and the base, with one end connected to the center of the support member in the longitudinal direction and the other end connected to a portion of the support body below the connection portion with the support member, and is characterized in that it is provided with a deformation control member that acts in a direction to suppress bending or curvature in the event of bending or curvature of the support member.

4. 3. The support structure according to claim 1, wherein the support member is formed in a curved or bent shape that is convex in a direction approaching the support body and the base.

5. 3. The support structure according to claim 1, wherein both ends of the support member are connected to the base and the support body via hinges.

6. 3. The support structure according to claim 1, wherein a plurality of the support members are provided on at least the same side of the support body, either the valley side of the ground slope or the mountain side of the ground slope.

7. The plurality of support members provided on the same side are connected to the support body at the same height position, and the center portions in the length direction are connected to each other by a connecting member, 7. The support structure according to claim 6, wherein the connecting member applies a biasing force that counteracts a force acting in the direction of extension.

8. 7. The support structure according to claim 6, wherein the plurality of support members provided on the same side are configured to have different buckling strengths.

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