Safety fence and method for constructing safety fence

Abstract

To provide a construction method of a guard fence, in which a terminal support hardly falls even when falling rocks collide with the vicinity of the height of 1 / 3 of the guard fence or the vicinity of the height of 2 / 3 of the guard fence.SOLUTION: The method includes a first fixing step of fixing one end of the uppermost wire passing through the end column to the first pile via a buffer fitting, and fixing one end of the lowermost wire passing through the end column to the second pile; a second fixing step of fixing one end of the first side wire to a portion corresponding to a position of one third of the height of the end column, and fixing the other end of the first side wire to the first pile; and a third fixing step of fixing one end of the second side wire to a portion corresponding to a position of one half of the height of the end column, and fixing the other end of the second side wire to the second pile.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a protective fence and a method for constructing the protective fence. [Background technology]

[0002] Patent Document 1 discloses a rockfall protection fence comprising a pair of terminal posts constructed on a slope where rockfalls are likely to occur, multiple intermediate posts constructed between the terminal posts, multiple wires stretched at intervals in the vertical direction along the mountain side of the terminal posts and intermediate posts, wire mesh stretched over the entire mountain side of the wires, and spacing members arranged perpendicular to the wires to maintain the vertical spacing of the wires.

[0003] Figures 1 and 2 show a conventional example of such a rockfall protection fence. As shown in Figure 1(A), a conventional rockfall protection fence 100 has an uppermost side rope 2, middle side ropes 10A, 10B, 10C, and 10D (hereinafter sometimes collectively referred to as "middle side rope 10"), and a lowermost side rope 6 attached, from top to bottom, to end supports 1 and intermediate supports 11 made of H-beam steel.

[0004] As shown in FIG. 2(A), U-bolt holes 20 are formed in one flange of intermediate support 11 at positions where the top side rope 2 and the middle side rope 10 will be installed. U-bolt holes 20 are also formed in a part of the base 21 of intermediate support 11 at positions where the bottom side rope 6 will be installed. Then, as shown in FIG. 2(B), U-bolts 22 are attached to U-bolt holes 20 so that the top side rope 2 and the middle side rope 10 are sandwiched between the flange in which U-bolt holes 20 are formed and the U-shaped portion of U-bolt 22. Similarly, the bottom side rope 6 is attached using a part of base 21 and U-bolt 22 so that the bottom side rope 6 passes through the lower end of intermediate support 11. In this way, the top side rope 2, the middle side rope 10, and the bottom side rope 6 are each attached to the intermediate support 11. The top side rope 2 and the bottom side rope 6 are attached to the terminal support 1 in the same manner as the intermediate support 11, and their ends pass through the terminal support 1 toward the outside of the rockfall protection fence 100 and are connected to anchors 4 and 5. On the other hand, the ends of the middle side ropes 10 are fixed to the terminal support 1 at their respective height positions.

[0005] Diamond-shaped wire mesh 9 for catching falling rocks is attached to the top side rope 2, middle side rope 10, and bottom side rope 6 using a coupling coil. In addition, spacing retaining members 7 for maintaining the distance between the top side rope 2, middle side rope 10, and bottom side rope 6 are attached. Conventionally, as shown in Figure 1, three spacing retaining members 7 are attached between adjacent posts (one span).

[0006] The end of the middle side rope 10 is connected to a buffer metal fitting fixed to the terminal support 1 via a turnbuckle 3D. The turnbuckle 3D is used to adjust the tension of the middle side rope 10.

[0007] The end of the uppermost side rope 2 is supported by the upper end of the terminal support 1, passes through the terminal support 1, and is fixed to the anchor 4 via a turnbuckle 3A and a buffer fitting 12A, etc. Meanwhile, the end of the lowermost side rope 6 is supported by the lower end of the terminal support 1, passes through the terminal support 1, and is fixed to the anchor 5 via a turnbuckle 3C.

[0008] In addition, one end of a side support rope 19 supporting the terminal support pole 1 is fixed to the terminal support pole 1 via an eyebolt 13, and the other end of the side support rope 19 is fixed to the anchor 4 via a turnbuckle 3B.

[0009] As shown in Fig. 1(B), anchors 4 and 5 are installed side by side on a straight line extending from terminal support 1. However, they may not be installed on a straight line.

[0010] As shown in Figure 2(C), one end of stay rope 14 supporting terminal support 1 is fixed to the top of terminal support 1, and the other end of stay rope 14 is fixed to anchor 15 installed on the valley side of terminal support 1. Also, one end of suspension stay rope 16 supporting terminal support 1 is fixed to the top of terminal support 1, and the other end of suspension stay rope 16 is fixed via a shock absorber and turnbuckle 17 to anchor 18 installed on the mountain side of terminal support 1. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Publication No. 2020-056272 Summary of the Invention [Problem to be solved by the invention]

[0012] In the rockfall protection fence 100 described above, the areas most likely to be hit by falling rocks are the areas indicated by the symbol X in FIG. 1(A) (corresponding to two-thirds of the height of the rockfall protection fence 100) and the area indicated by the symbol Y (corresponding to one-third of the height of the rockfall protection fence 100). A weight impact experiment was then conducted in which a weight simulating a falling rock was impacted against the rockfall protection fence 100. The results showed that when the weight impacts the area indicated by the symbol X, a force is applied to the middle side ropes 10A and 10B, pulling the terminal support pole 1 toward the intermediate support pole 11 and applying a large force to the side support ropes 19 and anchors 4, making the terminal support pole 1 unable to withstand the torsional load and prone to break and tipping over. Furthermore, the results showed that when the weight impacts the area indicated by the symbol Y, the terminal support pole 1 is prone to break and tipping over because there are no side support ropes at one-third of the height of the rockfall protection fence 100.

[0013] Therefore, the object of the present invention is to provide a guardrail and a method for constructing a guardrail that is less likely to break or tip over even when a falling rock strikes the guardrail at approximately one-third or two-thirds of the height of the guardrail. [Means for solving the problem]

[0014] One aspect of the present invention is a method for constructing a protective fence including a plurality of posts, a plurality of wires supported horizontally on the plurality of posts, and wire mesh attached to the plurality of wires, the method comprising: a first fixing step of fixing one end of the uppermost wire supported on the upper end of an end post of the plurality of posts and passing through the end post, and one end of the lowermost wire supported on the lower end of the end post and passing through the end post, to a first post via a shock absorber; a second fixing step of fixing one end of a first side wire to a portion corresponding to a position one-third of the height of the end post and fixing the other end of the first side wire to the first post; and a third fixing step of fixing one end of a second side wire to a portion corresponding to a position two-thirds of the height of the end post and fixing the other end of the second side wire to the second post.

[0015] In one aspect of the present invention, the first pile and the second pile are installed in positions where the end support, the first pile, and the second pile are not aligned in a straight line when viewed in a plane.

[0016] In addition, in one aspect of the present invention, the end support is an H-beam, and a reinforcing member is provided to block at least a portion of the groove formed by the flange and web of the H-beam.

[0017] In addition, in one aspect of the present invention, one end of the lowest wire is supported by a part of the base of the end support instead of being supported by the lower end of the end support.

[0018] Another aspect of the present invention is a protective fence including a plurality of posts, a plurality of wires supported horizontally on the posts, wire mesh attached to the plurality of wires, a first side wire, and a second side wire, wherein one end of the uppermost wire supported by the upper end of an end post of the plurality of posts and passing through the end post, and one end of the lowermost wire supported by the lower end of the end post and passing through the end post, are fixed to a first post via a shock absorber, one end of the first side wire is fixed to a portion corresponding to a position one-third of the height of the end post, the other end of the first side wire is fixed to the first post, one end of the second side wire is fixed to a portion corresponding to a position two-thirds of the height of the end post, and the other end of the second side wire is fixed to a second post.

[0019] In another aspect of the present invention, the first pile and the second pile are installed in positions where the end support, the first pile, and the second pile are not aligned in a straight line when viewed in a plane.

[0020] In another aspect of the present invention, the end support is an H-beam, and a reinforcing member is provided to block at least a portion of the groove formed by the flange and web of the H-beam.

[0021] In another aspect of the present invention, one end of the lowest wire is supported by a part of the base of the end support instead of being supported by the lower end of the end support. [Effects of the Invention]

[0022] According to this invention, in the event of a rockfall impact at two-thirds the height of the protective fence, the second side wire, the top wire, and the buffer fittings work effectively, and the impact load can be borne by the first and second piles, making it difficult for the terminal posts to tip over; and in the event of a rockfall impact at one-third the height of the protective fence, the first side wire, the bottom wire, and the buffer fittings work effectively, and the impact load can be borne by the first pile, making it possible to create a protective fence that is difficult for the end posts to break and tip over. [Brief explanation of the drawings]

[0023] [Figure 1] 1A is a front view showing a part of a conventional rockfall protection fence 100, and FIG. 1B is a schematic plan view showing a part of a conventional rockfall protection fence 100. FIG. [Figure 2] 1A is a front view of a conventional intermediate support 11, FIG. 1B is a side view of the same, and FIG. 1C is a side view showing a part of a conventional rockfall protection fence 100. FIG. [Figure 3] 1A is a front view showing an example of a rockfall protection fence 300 according to this embodiment, and FIG. 1B is a schematic plan view showing an example of a rockfall protection fence 300 according to this embodiment. [Figure 4] FIG. 1 is a front view showing an example of construction near one terminal support 31 of a rockfall protection fence 300 according to this embodiment. [Figure 5] 10 is a diagram showing an example of the connection between the top side rope 32 and the bottom side rope 33 of the rockfall protection fence 300 according to this embodiment. FIG. [Figure 6] 10 is a diagram showing an example of connection of the upper side support rope 34 of the rockfall protection fence 300 according to this embodiment. FIG. [Figure 7] 1 is a side view showing an example of a rockfall protection fence 300 according to an embodiment of the present invention. [Figure 8] FIG. 2 is a perspective view showing an example of a terminal support 31 according to the present embodiment. [Figure 9] (A) and (B) are perspective views showing an example of a reinforced terminal support 31 according to this embodiment, and (C) is a transparent front view showing an example of a reinforced terminal support 31 according to this embodiment. [Figure 10] (A) is a front view showing an example of a reinforced terminal support 31 according to this embodiment, (B) is a side view of the same, (C) is a plan view showing an example of a reinforcing plate 77 according to this embodiment, and (D) is a DD cross-sectional view of Figure 10(B) showing an example of a reinforcing plate attached to the terminal support 31 according to this embodiment. [Figure 11] 1A is a perspective view showing an example of a reinforced terminal support 31 according to the present embodiment, and FIG. 1B is a transparent front view showing an example of a reinforced terminal support 31 according to the present embodiment. [Figure 12] 1A is a perspective view showing an example of a reinforced terminal support 31 according to the present embodiment, and FIG. 1B is a transparent front view showing an example of a reinforced terminal support 31 according to the present embodiment. [Figure 13] 1A is a front view showing an example of a reinforced terminal support 31 according to this embodiment, FIG. 1B is a left side view thereof, and FIG. 1C is a right side view thereof. [Figure 14] 10 is a flowchart showing an example of the flow of a construction method for the rockfall protection fence 300 according to this embodiment. [Figure 15] 1 is a schematic plan view showing an example of a rockfall protection fence 300 according to an embodiment of the present invention. [Figure 16] 10A and 10B are cross-sectional views of a reinforced end support 31 in a modified example. [Figure 17] 10A is a front view showing an example of a reinforced terminal support 31 in a modified example, FIG. 10B is a left side view of the same, and FIG. 10C is a right side view of the same. DETAILED DESCRIPTION OF THE INVENTION

[0024] An embodiment of the present invention will be described with reference to the drawings.

[0025] 3 and 4, the rockfall protection fence 300 according to this embodiment has an intermediate support 41 erected between two terminal supports 31, and from the top, these supports are equipped with an uppermost side rope 32, middle side ropes 40A, 40B, 40C, and 40D (hereinafter sometimes collectively referred to as "middle side rope 40"), and a lowermost side rope 33. The terminal supports 31 and intermediate supports 41 according to this embodiment are approximately 2.5 m high, and are fixed to the ground by support anchors 38 via foundations 63 on which the supports are erected.

[0026] Diamond-shaped wire mesh 39 for catching falling rocks is attached to the top side rope 32, the middle side rope 40 and the bottom side rope 33 by connecting coils.

[0027] The ends of the middle side ropes 40A, 40B, 40C, and 40D are fixed to the terminal support 31 via turnbuckles 47A, 47B, 47C, and 47D and shock absorbers 54A, 54B, 54C, and 54D, respectively. The shock absorbers are attached to the ends of the wires and slide to absorb energy when a certain tension is applied to the wires.

[0028] The end of the uppermost side rope 32 is supported by the upper end of the terminal support 31, passes through the terminal support 31 from the center of the rockfall protection fence 300 toward the outside (to the left of the plane of the paper for the terminal support 31 on the left side of FIG. 3, to the right of the plane of the paper for the terminal support 31 on the right side of FIG. 3, and to the left of the plane of the paper for the terminal support 31 in FIG. 4), and is fixed to the first anchor 37. Meanwhile, the end of the lowermost side rope 33 is supported by a part of the base 63 of the terminal support 31 using a U-bolt, passes through the terminal support 31 from the center of the rockfall protection fence 300 toward the outside (to the left of the plane of the paper for the terminal support 31 on the left side of FIG. 3, to the right of the plane of the paper for the terminal support 31 on the right side of FIG. 3, and to the left of the plane of the paper for the terminal support 31 in FIG. 4), and is fixed to the first anchor 37.

[0029] 5, the end of the uppermost side rope 32 to which the winding grip 55 is attached is attached to a loop formed at one end of the shock absorber 54J, and similarly, the end of the lowermost side rope 33 to which the winding grip 56 is attached is attached to a loop formed at one end of the shock absorber 54J. The other end of the shock absorber 54J is attached to the first anchor 37 via the mounting bracket 50 that connects the first anchor 37 and the turnbuckle 47J, and the turnbuckle 47J.

[0030] The method of attaching the top side rope 32 and the bottom side rope 33 to the terminal support 31 and the intermediate support 41 may be the same as the conventional attachment method (see Figure 2(B)). Also, the bottom side rope 33 may be attached directly to the lower end of the terminal support 31 or the intermediate support 41 (so as not to interfere with the foundation 63), just like the top side rope 32.

[0031] Also, as shown in Figure 4, one end of the upper side support rope 34 supporting the terminal support 31 is fixed to a part corresponding to approximately two-thirds of the height of the terminal support 31 (height from the lower end of the terminal support 31), and the other end of the upper side support rope 34 is fixed to the second anchor 36.

[0032] 6, one end of the upper side support rope 34, to which the winding grip 43A is attached, is connected via a turnbuckle 47K to an eye nut 48 attached to the terminal support pole 31 at a height of approximately two-thirds of the way up. The eye nut 48 is attached to the terminal support pole 31 with a bolt 49. The other end of the upper side support rope 34, to which the winding grip 43B is attached, is fixed to the second anchor 36 via a mounting bracket 42 that connects the second anchor 36 and the turnbuckle 47K.

[0033] Also, as shown in Figure 4, one end of the lower side support rope 35 supporting the terminal support 31 is fixed via a turnbuckle 47L to a part corresponding to approximately one-third of the height of the terminal support 31 (height from the bottom end of the terminal support 31), and the other end of the lower side support rope 35 is fixed to the first anchor 37 via a mounting bracket 50 that connects the first anchor 37 and the lower side support rope 35.

[0034] Specifically, one end of the lower side support rope 35, to which the winding grip is attached, is connected via a turnbuckle 47L to an eye nut 60 attached to the terminal support pole 31 at a height of approximately one-third of the length. The eye nut 60 is attached to the terminal support pole 31 with a bolt 61. The other end of the lower side support rope 35, to which the winding grip is attached, is fixed to the first anchor 37 via a mounting bracket 50.

[0035] As shown in FIG. 3(B), the first anchor 37 and the second anchor 36 are installed at positions where they are not aligned in a straight line when viewed from above. The installation positions of the first anchor 37 and the second anchor 36 can be changed as appropriate depending on the topography of the location where the rockfall protection fence 300 is to be installed. Although the terminal support 31, the first anchor 37, and the second anchor 36 may be installed at positions where they are aligned in a straight line when viewed from above, it is preferable to install the first anchor 37 and the second anchor 36 at positions where they are not aligned in a straight line when viewed from above. It is also preferable to install the first anchor 37 and the second anchor 36 at a distance (e.g., 1 m or more) that does not affect each other's bearing capacity.

[0036] 7, one end of a suspension rope 62 supporting the terminal support pole 31 is fixed to the top of the terminal support pole 31, and the other end of the suspension rope 62 is fixed via a shock absorber to an anchor 30 installed on the mountain side of the terminal support pole 31. Note that although this embodiment illustrates an example in which the rockfall protection fence 300 is installed on a slope, the rockfall protection fence 300 may also be installed on level ground.

[0037] In the rockfall protection fence 300 of this embodiment, for example, if a rock falls at the section indicated by symbol P in Figure 3(A) (two-thirds of the height of the rockfall protection fence 300), a force will act to cause the terminal support pole 31 to tip toward the intermediate support pole 41. However, this force is borne by the upper side support rope 34 and the second anchor 36, and is also borne by the top side rope 32, the shock absorber 54J, and the first anchor 37, preventing the terminal support pole 31 from tipping toward the intermediate support pole 41. In other words, the load that would normally be applied to the middle side ropes 40A, 40B can be borne.

[0038] Furthermore, with the rockfall protection fence 300 of this embodiment, if a rock falls at the section indicated by symbol Q in Figure 3(A) (one-third of the height of the rockfall protection fence 300), a force will act to cause the terminal support pole 31 to tip toward the intermediate support pole 41, but this force is borne by the lower side support rope 35 and the first anchor 37, and can also be borne by the lowest side rope 33, buffer fitting 54J, and first anchor 37, preventing the terminal support pole 31 from tipping toward the intermediate support pole 41. In other words, the load that would normally be applied to the middle side ropes 40C, 40D can be borne.

[0039] In addition, by attaching one end of the upper side support rope 34 at a position two-thirds the height of the terminal support 31 and installing the other end on the mountain side of the diamond-shaped wire mesh 39 using a second anchor 36, it is possible to reduce the torsional load on the terminal support 31 and prevent the terminal support 31 from collapsing toward the center.

[0040] In this embodiment, the uppermost side rope 32 and the lowermost side rope 33 are attached to one shock absorber fitting 54J and fixed to the first anchor 37, but separate shock absorbers may be attached to the uppermost side rope 32 and the lowermost side rope 33 and fixed to the first anchor 37. In this case, one more shock absorber fitting is required, which increases costs. On the other hand, even when attached to one shock absorber fitting 54J as in this embodiment, the force of a falling rock can be sufficiently absorbed unless the falling rock hits the upper and lower parts of the protective fence simultaneously (which is unlikely).

[0041] 3(A), in this embodiment, one spacing member 44 is attached to one span (between adjacent columns). This allows the buffer metal fittings to function efficiently and suppress the load on the terminal columns 31.

[0042] Next, a method for reinforcing the terminal struts 31 will be described. Because a large force is applied to the terminal struts 31 in the event of a rockfall collision, a stronger terminal strut 31 is required. Conventional terminal struts 31 use, for example, 100 mm x 100 mm H-beams. To increase strength, it is possible to change to thicker 150 mm x 150 mm H-beams, but this increases costs and the burden of installation work. Therefore, a method for reinforcing the terminal struts 31 that can increase the strength of conventional H-beams without changing the size is required.

[0043] 8, the H-beam used in the conventional terminal support 31 has one web 81 and flanges 82, 83 respectively provided at both ends of the web 81. The web 81 has mounting holes 76, 74, 73, 71 for attaching the middle side ropes 40A, 40B, 40C, 40D, respectively, and also has mounting holes 75, 72 for attaching the upper side support rope 34 and the lower side support rope 35, respectively.

[0044] As shown in FIG. 10(A), reinforcing metal fittings 71A-76A and 71B-76B are attached to both sides of the portion of the web 81 where the mounting holes 71-76 are formed.

[0045] In this embodiment, in order to reinforce this H-beam, a reinforcing plate is provided as a reinforcing member so as to cover at least a part of the groove formed by the flanges 82, 83 and the web 81. Below, specific examples 1 and 2 of the method of attaching the reinforcing plate will be described.

[0046] A first specific example of a method for attaching a reinforcing plate will be described with reference to FIGS. 9(A) to 9(C) and 10(A) to 10(D).

[0047] In specific example 1, as shown in FIGS. 10(A) and 10(B), reinforcing plates 77A and 77B (see FIG. 10(C)) are attached to one groove of the H-beam. The reinforcing plates 77A and 77B (hereinafter sometimes collectively referred to as "reinforcing plates 77") are attached to a portion corresponding to one-third of the height of the terminal support 31, where a large force is applied in the event of a rockfall, and a portion corresponding to two-thirds of the height of the terminal support 31. Here, the reinforcing plates are attached to positions corresponding to mounting holes 71, 72, and 73, and positions corresponding to mounting holes 74, 75, and 76, respectively. In addition, three mounting holes 85A, 85B, and 85C (85D, 85E, and 85F) of the same diameter are formed in the reinforcing plate 77A (77B) at positions facing the mounting holes 71, 72, and 73 (74, 75, and 76) when the plate is attached to the H-beam.

[0048] The length of the reinforcing plate 77 in the longitudinal direction is longer than the distance between the mounting holes 71 and 73, and is a length that covers the mounting holes 71 and 73 when the H-beam with the reinforcing plate 77 attached is viewed from the side. On the other hand, the length of the reinforcing plate 77 in the lateral direction is longer than the distance between the outer surface 82a of the flange 82 and the outer surface 83a of the flange 83, and is a length that covers the flanges 82 and 83 where the reinforcing plate 77 is attached when the H-beam with the reinforcing plate 77 attached is viewed from the side.

[0049] The reinforcing plate 77 is attached to the H-beam by welding. As shown in Figure 10(D), the reinforcing plate 77 is placed so as to span the flanges 82 and 83 (so as to close one of the grooves formed by the web 81 and the flanges 82 and 83 (the upper groove in the example of Figure 10(D))), and the reinforcing plate 77 is welded to the flanges 82 and 83 using filler metal 84.

[0050] 9(A)-(C), eye nuts 46 are attached to the reinforced terminal support 31 in Example 1 with bolts 45 inserted through mounting holes 71, 73, 74, 76 and mounting holes 85A, 85C, 85D, 85F. Buffer metal fittings 54A, 54B, 54C, 54D, to which the middle side rope 40 is connected, are attached to each eye nut 46. In the example of FIGS. 9(A)-(C), buffer metal fittings 54A, 54B, 54C, 54D are attached to the side of the terminal support 31 on which the reinforcing plate 77 is attached.

[0051] Furthermore, eye nuts 48 for attaching the lower side support ropes 35 are attached to the reinforced terminal strut 31 in Example 1 by bolts 49 inserted through the mounting holes 72 and 85B, respectively. Similarly, eye nuts 60 for attaching the upper side support ropes 34 are attached by bolts 61 inserted through the mounting holes 75 and 85E, respectively. That is, the eye nuts 48, 60 are fastened to bolts 49, 61 that pass through the H-beam web 81 and the reinforcing plate 77 attached to the ends of the H-beam flanges 82, 83. In the example of Figures 9(A)-(C), the bolts 49, 61 are inserted from the side of the terminal strut 31 where the reinforcing plate 77 is attached, and are fastened to the eye nuts 48, 60.

[0052] 9, shock absorbers 54A, 54B, 54C, and 54D and eye nuts 48 and 60 may be attached to the opposite side of terminal support 31. Specifically, as shown in FIGS. 11(A) and 11(B), eye nuts 80 are attached to the reinforced terminal support 31 in Example 1 from the side where reinforcing plate 77 is attached using bolts 78 inserted through mounting holes 71, 73, 74, and 76 and mounting holes 85A, 85C, 85D, and 85F. Shock absorbers 54A, 54B, 54C, and 54D, to which the middle side rope 40 is connected, are attached to each eye nut 80. That is, in the example of FIGS. 11(A) and 11(B), shock absorbers 54A, 54B, 54C, and 54D are attached to the side of terminal support 31 opposite to the side where reinforcing plate 77 is attached.

[0053] Additionally, eye nuts 48 for attaching the lower side support rope 35 are attached to the terminal support pole 31 by bolts 49 inserted through the mounting holes 72 and 85B, respectively. Similarly, eye nuts 60 for attaching the upper side support rope 34 are attached by bolts 61 inserted through the mounting holes 75 and 85E, respectively. That is, the eye nuts 48 and 60 are fastened to bolts 49 and 61 that pass through the H-beam web 81 and the reinforcing plate 77 attached to the ends of the H-beam flanges 82 and 83. In the example of Figures 11(A) and (B), the bolts 49 and 61 are inserted from the side opposite to the surface of the terminal support pole 31 where the reinforcing plate 77 is attached, and are fastened to the eye nuts 48 and 60.

[0054] Next, a second specific example of a method for attaching a reinforcing plate will be described with reference to FIGS. 12(A), 12(B), and 13(A) to 13(C).

[0055] In Example 2, as shown in FIGS. 13(A)-(C), reinforcing plates 90A, 90B, 90C, and 90D (hereinafter sometimes collectively referred to as "reinforcing plates 90") are attached to one groove of the H-beam, and reinforcing plates 94A and 94B (hereinafter sometimes collectively referred to as "reinforcing plates 94") are attached to the other groove of the H-beam. Reinforcing plates 90 and 94 are attached to a portion corresponding to one-third of the height of terminal support 31, where a large force is applied in the event of a rockfall, and a portion corresponding to two-thirds of the height of terminal support 31. Here, reinforcing plates 90A and 90B are attached to the left side of the H-beam at positions corresponding to mounting holes 71 and 73, and reinforcing plate 94A is attached to the right side of the H-beam at positions corresponding to mounting hole 72. Similarly, reinforcing plates 90C and 90D are attached to the left side of the H-beam at positions corresponding to mounting holes 74 and 76, and reinforcing plate 94B is attached to the right side of the H-beam at positions corresponding to mounting hole 75. Furthermore, mounting holes 95A, 95B, 95C, and 95D having the same diameter as mounting hole 71, etc. are formed at the centers of reinforcing plates 90A, 90B, 90C, and 90D. Similarly, mounting holes 96A and 96B having the same diameter as mounting hole 71, etc. are formed at the centers of reinforcing plates 94A and 94B.

[0056] The reinforcing plates 90 are substantially square when attached to the H-beam and viewed from the left side of the H-beam, and one plate is attached to each of the attachment holes 71, 73, 74, and 76.

[0057] 13(A), when the H-beam is viewed from the right side, the reinforcing plate 94 has a rectangular shape, and its longitudinal length is such that, when the H-beam is viewed from the front, one end of the reinforcing plate 94A overlaps one end of the reinforcing plate 90A and the other end of the reinforcing plate 94A overlaps one end of the reinforcing plate 90B. On the other hand, the lateral length of the reinforcing plate 94 is longer than the distance between the outer surface 82a of the flange 82 and the outer surface 83a of the flange 83, and is such that, when the H-beam with the reinforcing plate 94 attached is viewed from the side, the reinforcing plate 94 covers the flanges 82 and 83 where the reinforcing plate 77 is attached.

[0058] The reinforcing plate 77 is attached to the H-beam by welding, as in the first example.

[0059] 12(A) and (B), eye nuts 80 are attached to the reinforced terminal support 31 in Example 2 with bolts 78 inserted through mounting holes 71, 73, 74, 76 (see FIG. 8) and mounting holes 95A, 95B, 95C, 95D. Buffer metal fittings 54A, 54B, 54C, 54D, to which the middle side rope 40 is connected, are attached to each eye nut 80, respectively.

[0060] Furthermore, eye nuts 48 for attaching the lower side support rope 35 are attached to the reinforced terminal support pole 31 in Example 2 by bolts 49 inserted through the mounting holes 72 and 96A, respectively. Similarly, eye nuts 60 for attaching the upper side support rope 34 are attached by bolts 61 inserted through the mounting holes 75 and 96B, respectively. As with Example 1, as a modification of the example in Fig. 12, shock absorbing fittings 54A, 54B, 54C, and 54D and eye nuts 48 and 60 may be attached to the opposite surfaces of the terminal support pole 31.

[0061] As described above, in this embodiment, a reinforcing plate is provided on the terminal support 31, so that it can withstand torsional loads, etc., and the attachment portions of the side support ropes 34, 35 and the middle side rope 40 on the terminal support 31 are less likely to break.

[0062] Next, the flow of the construction method for the rockfall protection fence 300 will be described with reference to FIG.

[0063] First, the first fixing step (step S1) is performed. In this step, one end of the uppermost side rope 32, which is supported on the upper end of the terminal support 31 and passes through the terminal support 31, and one end of the lowermost side rope 33, which is supported on a part of the base 63 of the terminal support 31 and passes through the terminal support 31, are fixed to the first anchor 37 via a shock absorber 54J. For example, a winding grip 55 is attached to one end of the uppermost side rope 32 and connected to the shock absorber 54, and a winding grip 56 is attached to one end of the lowermost side rope 33 and connected to the shock absorber 54. The shock absorber 54 is then connected to the first anchor 37 via a turnbuckle 47J and a mounting bracket 50, and the tension of the uppermost side rope 32 and the lowermost side rope 33 is adjusted by the turnbuckle 47J.

[0064] Next, the second fixing step (step S2) is performed. In this step, one end of the lower side support rope 35 is fixed to a portion corresponding to a position one-third of the height of the terminal support pole 31, and the other end of the lower side support rope 35 is fixed to the first anchor 37. For example, one end of the lower side support rope 35 is connected to a portion corresponding to a position one-third of the height of the terminal support pole 31 via a turnbuckle 47L, and the tension of the lower side support rope 35 is adjusted by the turnbuckle 47L. Then, the other end of the lower side support rope 35 is fixed to the first anchor 37 via a mounting bracket 50.

[0065] Next, the third fixing step (step S3) is performed. In this step, one end of the upper side support rope 34 is fixed to a portion corresponding to a position two-thirds of the height of the terminal support pole 31, and the other end of the upper side support rope 34 is fixed to the second anchor 36. For example, one end of the upper side support rope 34 is connected to a portion corresponding to a position two-thirds of the height of the terminal support pole 31 via a turnbuckle 47K, and the tension of the upper side support rope 34 is adjusted by the turnbuckle 47K. Then, the other end of the upper side support rope 34 is fixed to the second anchor 36 via the mounting bracket 42. When the third fixing step (step S3) is completed, the construction method for the rockfall protection fence 300 is completed.

[0066] The order of the first fixing step, the second fixing step, and the third fixing step may be reversed.

[0067] As explained above, the construction method for the rockfall protection fence 300 according to this embodiment is a construction method for the rockfall protection fence 300 including the terminal support 31 (an example of a "support"), the intermediate support 41 (an example of a "support"), the uppermost side rope 32 (an example of a "wire"), the middle side rope 40 (an example of a "wire"), and the lowermost side rope 33 (an example of a "wire") that are supported horizontally by the terminal support 31 and the intermediate support 41, and the diamond-shaped wire mesh 39 (an example of a "wire mesh") attached to these side ropes, and includes one end of the uppermost side rope 32 (an example of an "uppermost wire") that is supported by the upper end of the terminal support 31 (an example of an "end support") and passes through the terminal support 31, and one end of the lowermost side rope 33 (an example of a "lowermost wire") that is supported by a part of the base 63 of the terminal support 31 and passes through the terminal support 31. The method includes a first fixing step (step S1) of fixing one end of the lower side support rope 35 (an example of a "first side wire") to the first anchor 37 (an example of a "first pile") via a shock absorber 54J (an example of a "shock absorber"); a second fixing step (step S2) of fixing one end of the lower side support rope 35 (an example of a "first side wire") to a portion corresponding to a position one-third of the height of the terminal support pole 31 and fixing the other end of the lower side support rope 35 (an example of a "first side wire") to the first anchor 37; and a third fixing step (step S3) of fixing one end of the upper side support rope 34 (an example of a "second side wire") to a portion corresponding to a position two-thirds the height of the terminal support pole 31 and fixing the other end of the upper side support rope 34 (an example of a "second side wire") to the second anchor 36 (an example of a "second pile").

[0068] Therefore, according to the construction method for the rockfall protection fence 300 of this embodiment, in the event of a rockfall collision at two-thirds the height of the rockfall protection fence 300, the upper side support rope 34, the top side rope 32, and the buffer fitting 54J will work effectively, and the collision load can be borne by the first anchor 37 and the second anchor 36, making it difficult for the terminal support pole 31 to tip over; and in the event of a rockfall collision at one-third the height of the protection fence, the lower side support rope 35, the bottom side rope 33, and the buffer fitting 54J will work effectively, and the collision load can be borne by the first anchor 37, making it possible to construct a rockfall protection fence 300 in which the terminal support pole 31 is less likely to break and less likely to tip over.

[0069] Furthermore, in the construction method for the rockfall protection fence 300 according to this embodiment, the first anchors 37 and second anchors 36 are installed in positions where they are not aligned in a straight line when viewed from above (i.e., not aligned in a straight line as shown in FIG. 1(B)). This allows the force of a falling rock to be dissipated in multiple directions when it hits the diamond-shaped wire mesh 39, making it difficult for the terminal support 31 and intermediate support 41 to tip over. As a modified example, the terminal support 31, first anchor 37, and second anchor 36 may not be aligned in a straight line when viewed from above, as shown in FIGS. 15(A)-(C).

[0070] Furthermore, in the construction method of the rockfall protection fence 300 according to this embodiment, the terminal supports 31 are H-beams, and reinforcing plates 77, 90, 94 (an example of a "reinforcing member") are provided to close at least part of the grooves formed by the flanges 82, 83 of the H-beams and the web 81. This reinforces the terminal supports 31, improving the strength of the rockfall protection fence 300.

[0071] Furthermore, in the construction method for the rockfall protection fence 300 according to this embodiment, one end of the lowest side rope 33 may be supported by the lower end of the terminal support 31 instead of being supported by part of the foundation 63 of the terminal support 31. For example, similar to the middle side rope 10 in Figure 2, U-bolt holes 20 may be formed in the flange at the lower end of the support, and U-bolts 22 may be attached to the U-bolt holes 20 so that the lowest side rope 6 is sandwiched between the flange in which the U-bolt holes 20 are formed and the U-shaped portions of the U-bolts 22.

[0072] In the method of attaching the reinforcing plates 77, 90, and 94 in this embodiment, as shown in Fig. 10(D), the reinforcing plates 77, 90, and 94 are arranged so as to span the flanges 82 and 83 (so as to close the grooves formed by the web 81 and the flanges 82 and 83), and then welded to the flanges 82 and 83 using a filler metal 84. However, as shown in Figs. 16(A) and 16(B), for example, a reinforcing plate 97 may be provided by welding or the like between the flanges 82 and 83 so as to close the grooves formed by the web 81 and the flanges 82 and 83. In this case, the longitudinal length of the reinforcing plate 97 may be any length, like the reinforcing plate 90 and the reinforcing plate 94.

[0073] 17(A)-(C), reinforcing plates 98, 99 may be provided so as to cover most of the grooves formed by the web 81 and the flanges 82, 83. In this case, the reinforcing plates 98, 99 are formed with mounting holes 98A-98F and mounting holes 99A-99F having the same diameter as the mounting hole 71, etc., so that eye nuts 48, 60, 80 and bolts 49, 61, 78 can be attached. [Explanation of symbols]

[0074] 1: Terminal support 2: Top side rope 3A-3D: Turnbuckle 4: Anchor 5: Anchor 6: Bottom side rope 7: Spacing material 8: Fastening hardware 9: Diamond-shaped wire mesh 10: Middle side rope 10A-10D: Middle side rope 11: Intermediate support 12A: Buffer metal fittings 13: Eye bolt 14: Stay rope 15: Anchor 16: Hanging support rope 17: Turnbuckle 18: Anchor 19: Side support rope 20: U-bolt hole 21: Basics 22: U-bolt 30: Anchor 31: Terminal support 32: Top side rope 33: Bottom side rope 34: Upper side support rope 35: Lower side support rope 36: Second anchor 37: First anchor 38: Pole anchor 39: Diamond-shaped wire mesh 40: Middle side rope 40A-40D: Middle side rope 41: Intermediate support 42: Mounting bracket 43A, 43B: Wrapping grip 44: Spacing material 45: Bolt 46: Eye Nut 47A-47D: Turnbuckle 47J-47L: Turnbuckle 48: Ainat 49: Bolt 50: Mounting bracket 54A-54D: Buffer metal fittings 54J: Buffer metal fittings 55: Wrapping grip 56: Wrapping grip 60: Ainat 61: Bolt 62: Hanging rope 63: Basics 71: Mounting hole 71-76: Mounting holes 71A-76A: Reinforcement brackets 71B-76B: Reinforcement brackets 77: Reinforcement plate 77A, 77B: Reinforcement plate 78: Bolt 80: Ainat 81: Web 82: Flange 82a :face 83: Flange 83a :face 84: Filler metal 85A-85F: Mounting holes 90: Reinforcement plate 90A-90D: Reinforcement plates 94: Reinforcement plate 94A, 94B: Reinforcement plate 95A-95D: Mounting holes 96A, 96B: Mounting holes 97: Reinforcement plate 98: Reinforcement plate 98A-98F: Mounting holes 99: Reinforcement plate 99A-99F: Mounting holes 100: Rockfall protection fence 300: Rockfall protection fence

Claims

1. A method for constructing a protective fence including a plurality of posts, a plurality of wires horizontally supported by the plurality of posts, and a wire mesh attached to the plurality of wires, a first fixing step of fixing one end of the uppermost wire, which is supported on the upper end of an end support among the plurality of supports and passes through the end support, and one end of the lowermost wire, which is supported on the lower end of the end support and passes through the end support, to a first pile via a shock absorber; a second fixing step of fixing one end of a first side wire to a portion corresponding to a position one-third of the height of the support post at the end, and fixing the other end of the first side wire to the first post; a third fixing step of fixing one end of a second side wire to a portion corresponding to a position two-thirds of the height of the end support and fixing the other end of the second side wire to a second stake; A protective fence construction method comprising the steps of:

2. A method for constructing a protective fence according to claim 1, A method for constructing a protective fence, characterized in that the first pile and the second pile are installed in positions where the end support, the first pile, and the second pile are not aligned in a straight line when viewed in a plane.

3. A method for constructing a protective fence according to claim 1 or 2, The end supports are H-shaped steel beams, A protective fence construction method characterized in that a reinforcing member is provided to block at least a portion of the groove formed by the flange and web of the H-beam.

4. A method for constructing a protective fence according to claim 1, A method for constructing a protective fence, characterized in that one end of the lowest wire is supported by a part of the base of the end support instead of being supported by the lower end of the end support.

5. A safety fence including a plurality of posts, a plurality of wires horizontally supported by the plurality of posts, a wire mesh attached to the plurality of wires, a first side wire, and a second side wire, One end of the wire at the top of the plurality of supports, which is supported by and passes through the upper end of the support at the end, and one end of the wire at the bottom of the plurality of supports, which is supported by and passes through the lower end of the support at the end, are fixed to a first pile via a shock-absorbing metal fitting; One end of the first side wire is fixed to a portion corresponding to a position one-third of the height of the end support, and the other end of the first side wire is fixed to the first stake, A protective fence characterized in that one end of the second side wire is fixed to a portion corresponding to a position two-thirds of the height of the end support post, and the other end of the second side wire is fixed to a second stake.

6. The protective fence according to claim 5, A protective fence characterized in that the first pile and the second pile are installed in positions where the end support, the first pile, and the second pile are not aligned in a straight line when viewed in a plane.

7. The protective fence according to claim 5 or 6, The end supports are H-shaped steel beams, A protective fence characterized in that a reinforcing member is provided to block at least a portion of the groove formed by the flange and web of the H-beam.

8. The protective fence according to claim 5, A protective fence characterized in that one end of the lowest wire is supported by a part of the base of the end support post instead of being supported by the lower end of the end support post.

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