JP5688239B2 - Rock fall prevention fence - Google Patents

Description

  The present invention relates to a rockfall prevention fence that prevents rockfall on a road or the like.

  Conventionally, rockfall prevention fences have been installed on slopes along roads in order to prevent rockfalls from slopes to roads in mountainous areas.

  The rock fall prevention fence described in Patent Document 1 is such that a plurality of rope members are connected between struts so as to connect the upper and lower portions of adjacent struts to each other between the struts erected at a predetermined interval. Are arranged in the horizontal direction, and a plurality of net members are attached to the respective struts along the rope members.

  Moreover, in this rock fall prevention fence, the shock absorber is attached to the upper part and the lower part of each support | pillar, respectively, and the both ends of each rope material are each hold | gripped. Each shock absorber can set the gripping force of each rope material individually. When a tensile force exceeding the set gripping force is applied, the rope material is allowed to slide with respect to the shock absorber. Reduce the impact.

  Further, in this rock fall prevention fence, a diagonal rope member extending diagonally is connected between the pillars, and a shock absorber similar to the above is interposed in the middle of the diagonal rope member.

Japanese Patent No. 3385508

  However, in the above rockfall prevention fence, a plurality of rope members are routed in the horizontal direction between the columns, and shock absorbers are attached to the upper and lower portions of each column. Therefore, there is a problem that it takes time and labor for the adjustment.

  This invention is made | formed in view of the above situations, and it aims at providing the falling rock prevention fence which construction is easy.

In order to solve the above-mentioned problems, a rockfall prevention fence according to the present invention includes a plurality of struts erected at intervals, a wire mesh that covers between the plurality of struts and receives rockfall, and an upper portion of the wire mesh. An upper cable that supports the lower portion of the wire mesh, a reinforcing cable that reinforces the wire mesh between the columns, and the wire mesh that is coupled to the upper cable, the lower cable, and the reinforcing cable. A coupling portion; a shock absorber that absorbs kinetic energy of the falling rocks acting on the upper cable, the lower cable, and the reinforcing cable; and an anchor that fixes the upper cable, the lower cable, and the reinforcing cable to the ground, respectively. The wire mesh is provided continuously so as to cross all the columns in the arrangement direction, and the upper cable is Is held in all of the upper portion of the plurality of struts is routed continuously, both ends of the upper cable is fixed to the ground via the anchor, the lower cable, all of the lower portion of the plurality of struts The reinforcing cable is routed so as to pass through at least a part of a diagonal line in a rectangular plane formed between the support columns, and the shock absorbers are arranged at both ends of the upper cable. Between the two ends of the lower cable and the ground, and between the lower portion of the reinforcing cable and the ground, and the shock absorber has a first end portion. And a second end, and an absorption part that absorbs kinetic energy of the falling rock by extending with resistance between the first end and the second end, and The first end is the upper case. The second end portion is connected to the ground via the anchor. The second end portion is connected to the ground, the lower cable, or the reinforcing cable .

  In this rock fall prevention fence, all the shock absorbers are arranged in the vicinity of the ground, and the shock applied to the wire mesh when falling rocks can be effectively reduced by these shock absorbers. Specifically, the wire mesh is continuously provided so as to cross each column, and the upper and lower portions are supported by the upper cable and the lower cable, respectively, and further, the reinforcement cables are supported between the columns. Even if there is a falling rock in the area between any struts, the wire mesh catches this and each cable suppresses the deflection. Furthermore, when a certain tension or more is applied to each cable, the impact is mitigated by the action of a shock absorber installed near the ground.

  Specifically, both ends of the upper cable are connected to the ground via shock absorbers, and the intermediate part is supported by each column, so even if there is a falling rock in the area between any columns, It is possible for the shock absorbers at both ends to function by applying tension to the upper cable.

  Similarly, since both ends of the lower cable are connected to the ground via shock absorbers, and the middle part is supported by each column, even if there is a falling rock in the area between any columns, the lower cable It is possible for the shock absorbers at both ends to function as a result of the tension.

  In addition, the reinforcing cable is routed so as to pass through at least a part of a diagonal line in a rectangular plane formed between the support columns, and the lower part thereof is connected to the ground via a shock absorber. Even if there is a fallen rock, tension is applied to the reinforcing cable between the columns and the lower shock absorber can function.

In this way, these shock absorbers are installed at both ends of the upper cable fixed to the ground while being arranged so as to be able to absorb kinetic energy at the time of falling rocks, as well as both ends of the lower cable, and the reinforcing cable Are installed at the bottom of each. Specifically, the first end of the shock absorber is connected to an upper cable, a lower cable, or a reinforcing cable, and the second end of the shock absorber is connected to the ground via an anchor. For this reason, the work which climbs to the upper part of a support | pillar and attaches a shock absorber becomes unnecessary, and construction becomes very easy.

  In addition, in this structure, since the shock absorber is simply attached to both ends of the upper cable and the lower cable, the shock absorber can be greatly reduced.

Moreover, according to said structure, when the kinetic energy of falling rocks acted on the said upper cable, the said lower cable, or the said reinforcement cable, between these cables and the ground, the 1st end part of a shock absorber and The second end is pulled. At that time, the absorbing portion can absorb the kinetic energy of the falling rock by extending with resistance between the first end portion and the second end portion.

  Further, the reinforcing cable extends on the diagonal and extends from the lower part of the column to the upper part of the adjacent column, and the reinforcing cable extends on the diagonal and extends from the upper part of the column. It is preferable to further include a cross clip that has a second reinforcing cable extending downward and that holds a crossing portion of the first reinforcing cable and the second reinforcing cable.

  In this configuration, the first reinforcing cable and the second reinforcing cable constituting the reinforcing cable are arranged so as to cross between the support columns, so that the falling rocks can be more reliably prevented than when the reinforcing cable is arranged in parallel in the lateral direction. It is possible to prevent falling rocks from penetrating to the valley side. In addition, it is possible to disperse the kinetic energy of the falling rocks to both the first reinforcing cable and the second reinforcing cable via the cross clip, and to absorb the kinetic energy by the shock absorber attached to each cable.

  Alternatively, the reinforcing cable extends on the diagonal line, is folded back from the lower part of the column through a diagonal intermediate point and extends to the upper part of the column, and at a position facing the first reinforcing cable. A second reinforcing cable extending on the diagonal line and extending from a lower part of the column adjacent to the column through a diagonal middle point and extending to the upper part of the column, the first reinforcing cable and the Preferably, the second reinforcing cable further includes a holding ring for bundling and holding folded portions of the first and second reinforcing cables at the diagonal intermediate point.

  In this configuration, the first reinforcing cable and the second reinforcing cable extending on the diagonal line are folded back at the diagonal middle point between the support columns, and the folded part is bundled and held by the holding ring. Therefore, the falling rocks can be received more reliably than when the reinforcing cables are arranged in parallel in the lateral direction, and the falling rocks can be prevented from penetrating to the valley side. Moreover, it is possible to disperse the kinetic energy of the falling rocks to both the first reinforcing cable and the second reinforcing cable via the holding ring, and to absorb the kinetic energy by a shock absorber attached to each cable.

  Further, the coupling portion is composed of a coupling coil having a coil shape, and the upper cable, the lower cable, and the first and second reinforcing cables are wound inside the coupling coil together with the wire of the wire mesh, thereby It is preferably combined with a wire mesh.

  According to this configuration, since the wire mesh is connected to the upper cable, the lower cable, and the first and second reinforcing cables by the coupling coil, when the wire mesh receives a falling rock, the kinetic energy is passed through the coupling coil. Since these are securely distributed to these cables and absorbed by the shock absorbers attached to the respective cables, it is possible to receive rockfall of relatively large kinetic energy with a simple structure.

  As described above, according to the rockfall prevention fence of the present invention, the work of mounting the shock absorber becomes very easy with the kinetic energy at the time of rockfall, and the construction is easy.

It is a front view concerning 1st Embodiment of the rock fall prevention fence of this invention. It is a top view of the rock fall prevention fence of FIG. It is an enlarged front view which shows the attachment state of the cable in the support | pillar near the middle of the rock fall prevention fence of FIG. It is an enlarged front view which shows the attachment state of the cable in the support | pillar near the right end of the rock fall prevention fence of FIG. It is a right view which shows the attachment state of the cable in the support | pillar near the right end of the rock fall prevention fence of FIG. (A) is a front view of the shackle of FIG. 1, (b) is a left side view of the shackle. It is the enlarged view which looked at the cross clip vicinity of the rock fall prevention fence of FIG. 1 from the mountain side. It is the enlarged view which looked at the cross clip vicinity of the rock fall prevention fence of FIG. 1 from the trough side. It is a front view of the cross clip of FIG. It is a top view of the cross clip of FIG. It is a side view of the cross clip of FIG. FIG. 2 is a front view of a state in which a part of the plate portion of the brake element of FIG. 1 is cut away. It is a top view of the brake element of FIG. It is an enlarged front view of the wire clip which hold | grips the edge part of the 1st reinforcement cable of FIG. It is an enlarged front view of the wire clip which hold | grips the edge part of the upper cable of FIG. It is an enlarged front view of the example in which the holding ring was installed in the diagonal intermediate point concerning 2nd Embodiment of the rock fall prevention fence of this invention. It is an enlarged view of the holding ring of FIG.

(First embodiment)
Hereinafter, a rockfall prevention fence according to a first embodiment of the present invention will be described with reference to the drawings.

  The whole structure of the rock fall prevention fence 1 concerning 1st Embodiment is shown by FIGS.

  The rockfall prevention fence 1 includes, as main components, a plurality of support columns 2, a single upper cable 3, a single lower cable 4, a plurality of first reinforcing cables 5 and a second reinforcing cable 6 that cross each other. One wire net 7 and a plurality of brake elements 8 are provided.

  In this rock fall prevention fence 1, the workability is greatly improved by disposing the brake element 8 that absorbs the kinetic energy of the rock fall on the lower side of the rock fall prevention fence 1. In addition, the upper cable 3, the lower cable 4, and the wire mesh 7 have a seamless structure in which all the struts 2 are continuously traversed, and the kinetic energy of falling rocks can be received by the entire falling rock prevention fence. Therefore, the rockfall prevention fence 1 can receive rockfalls having a relatively large kinetic energy (about 100 KJ) with a simple structure.

  Hereinafter, the specific structure of the rock fall prevention fence 1 of 1st Embodiment is demonstrated. The rockfall prevention fence 1 further includes a cross clip 9, a coupling coil 10, a shackle 26, and a wire grip 12 in addition to the above-described components.

  As shown in FIGS. 1 and 2, the plurality of support columns 2 are erected on the ground G at intervals in a direction orthogonal to a direction facing the mountain side (hereinafter referred to as a mountain side direction) M. As the support 2, H-shaped steel or the like is used.

  As shown in FIGS. 3 to 5, each support column 2 has, in the upper part 2 a, a valley-side mounting portion 2 c that protrudes in a direction V (hereinafter referred to as a valley-side direction) V that faces the valley side, and a direction M that faces the mountain side. And a ridge-side mounting portion 2d that protrudes toward the center.

  Further, the lower portion 2 b of the support column 2 is fixed to the ground G via the base plate 21. The base plate 21 includes a pedestal 21a, a pair of column attachment plates 21b, and a shackle attachment portion 21c. The base 21a is fastened by a nut 34 to an anchor bolt 33 that protrudes from the cement anchor 22 embedded in the ground G to the ground surface. A pair of support | pillar mounting plates 21b are standingly arranged on the base 21a at intervals. The lower part 2 b of the support column 2 is sandwiched between a pair of support column mounting plates 21 b and connected by a bolt 30 and a nut 31. The shackle mounting portion 21c is fixed to the pedestal portion 21a at a position shifted in the valley side direction V from the column mounting plate 21b. The brake element 8 is connected to the shackle mounting portion 21c via a shackle 26 (see FIGS. 6A and 6B).

  The upper cable 3 is a cable that supports the upper part of the wire mesh 7, and is inserted into a shackle 26 attached to the upper part 2a of each column 2 as shown in FIGS. It is held by the upper part 2a and arranged continuously. Both end portions 3 a and 3 b of the upper cable 3 are fixed to the ground G via the brake element 8. Specifically, the cement anchor 22 is embedded in the ground G, and the brake element 8 is fixed to the anchor bolt 33 protruding from the cement anchor 22 with a nut or the like. Both ends 3 a and 3 b of the upper cable 3 are ring-shaped by being closed by a wire grip 12 (see FIGS. 14 to 15), and are connected to the end of the brake element 8.

  The lower cable 4 is a cable that supports the lower part of the wire mesh 7, and is inserted into a shackle 26 attached to the lower part 2b of each column 2 via a base plate 21, as shown in FIGS. It is held by all the lower parts 2b of the support column 2 and arranged continuously. Both end portions 4 a and 4 b of the lower cable 4 are fixed to the ground G via the brake element 8. Specifically, the cement anchor 22 is embedded in the ground G, and the brake element 8 is fixed to the anchor bolt 33 protruding from the cement anchor 22 with a nut or the like. Both ends 4 a and 4 b of the lower cable 4 are ring-shaped by being closed by a wire grip 12 (see FIGS. 14 to 15), and are connected to the end of the brake element 8.

  The first reinforcing cable 5 and the second reinforcing cable 6 that cross each other are cables that reinforce the wire mesh 7 between the columns 2, and are formed between the columns 2 as shown in FIGS. 1 and 3 to 4. Are arranged so as to pass through at least a part of the diagonal lines CL1 to CL4 in the rectangular plane.

  In the first embodiment, the first reinforcing cable 5 is routed so as to extend on the diagonal lines CL <b> 1 and CL <b> 2 and extend from the lower portion 2 b of the support column 2 to the upper portion 2 a of the adjacent support column 2. The second reinforcing cable 6 is routed so as to extend on the diagonal lines CL4 and CL3 and extend from the upper portion 2a of the support column 2 to the lower portion 2b of the adjacent support column 2.

  Lower ends 5a and 6a of the first and second reinforcing cables 5 and 6 are respectively attached to the lower portion 2b of the support column 2 (specifically, the shackle 26 attached to the base plate 21) via the brake element 8, The parts 5b and 6b are respectively attached to the upper part 2a of the support column 2 (specifically, the shackle 26 attached to the valley side attaching part 2c). The lower ends 5a and 6a and the upper ends 5b and 6b of the first and second reinforcing cables 5 and 6 are ring-shaped by being closed by a wire grip 12 (see FIGS. 14 to 15).

  The metal net 7 is a metal net that covers the space between the plurality of pillars 2 and receives falling rocks, and is continuously provided so as to cross all the pillars 2 in the arrangement direction. The wire mesh 7 is coupled to the upper cable 3, the lower cable 4, and the first and second reinforcing cables 5 and 6 by a coupling coil 10.

  As shown in FIGS. 1-2 and FIGS. 12-13, the brake element 8 absorbs the kinetic energy of falling rocks acting on the upper cable 3, the lower cable 4, and the first and second reinforcing cables 5, 6. It is a member and is included in the concept of the shock absorber of the present invention.

  As shown in FIGS. 12 to 13, the brake element 8 includes a first end 8 a connected to the upper cable 3, the lower cable 4, the first and second reinforcing cables 5 and 6, and the ground G. A second end portion 8b to be connected and an absorption portion 40 are provided. The absorption part 40 absorbs the kinetic energy of falling rocks by extending with resistance between the first end part 8a and the second end part 8b.

  The absorber 40 has a cable part 27 and a plate part 28. The cable portion 27 is made of a fiber core rope made of a high steel wire rod. The plate portion 28 is made of a steel plate having a plurality of holes 28a. The cable portion 27 has a large loop portion 27a by being passed through all the holes 28a of the plate portion 28 so as to be continuous.

  The first end portion 8a and the second end portion 8b are integrally formed at both end portions of the cable portion 27, and are formed by caulking both end portions of the cable portion 27 in a ring shape with an aluminum clamp portion 29. .

  1-2, the brake element 8 is provided between both ends 3a, 3b of the upper cable 3 and the ground G. Specifically, both ends 3a, 3b of the upper cable 3 and cement are provided. It is provided between the anchor bolts 33 protruding from the anchor 22. Similarly, the brake element 8 is provided between both ends 4 a and 4 b of the lower cable 4 and the ground G, and specifically, protrudes from both ends 4 a and 4 b of the lower cable 4 and the ground G and the cement anchor 22. It is provided between the anchor bolts 33 to be used.

  Further, as shown in FIGS. 1 and 3 to 4, the brake element 8 is provided between the lower portions 5 a and 6 a of the first and second reinforcing cables 5 and 6 and the ground G. Specifically, It is provided between the lower portions 5 a and 6 a of the first and second reinforcing cables 5 and 6 and the shackle 26 attached to the base plate 21 fixed to the cement anchor 22.

  Thus, the brake element 8 is arranged at the end of each cable 3-6, so that the kinetic energy at the time of falling rock received by the wire mesh 7 can be absorbed by the brake element 8 via the cables 3-6. Is possible. For example, when kinetic energy at the time of falling rock is propagated from the upper part of the wire mesh 7 to the upper cable 3, it is transmitted to both ends 3a, 3b of the upper cable 3 fixed to the ground G, and both ends 3a, 3b and the ground G The kinetic energy can be absorbed by the brake element 8 interposed therebetween. Similarly, the kinetic energy propagated from the lower part of the wire mesh 7 to the lower cable 4 can be absorbed by the brake element 8 interposed between the both ends 4a and 4b of the lower cable 4 and the ground G. Furthermore, the kinetic energy transmitted to the first reinforcing cable 5 or the second reinforcing cable 6 close to the position of the surface of the metal mesh 7 that has received the falling rock is between the first reinforcing cable 5 or the second reinforcing cable 6 and the ground G. Can be absorbed by the brake element 8 interposed between the two.

  Next, the energy absorption mechanism of the brake element 8 will be described. When the kinetic energy of falling rocks acts on the upper cable 3, the lower cable 4, the first and second reinforcing cables 5, 6 to which the brake element 8 is connected, the cable portion 27 constituting the absorbing portion 40 of the brake element 8. Is pulled suddenly. At this time, when a tensile load of a predetermined size or more is applied to the cable portion 27, the cable portion 27 and the inner peripheral surface of the hole 28a of the plate portion 28 and the surface of the plate portion 28 rub against each other and generate frictional heat. However, the loop portion 27a is reduced. At this time, the kinetic energy of falling rocks can be absorbed by the brake element 8 by converting the kinetic energy of falling rocks into frictional heat generated between the cable portion 27 and the plate portion 28.

  In 1st Embodiment, as FIG. 1-4 shows, all the brake elements 8 exist in the vicinity of the ground G, and are connected with all the cables 3-6. For example, the end 8b of the brake element 8 is directly connected to a shackle 26 disposed on an anchor bolt 33 projecting from the lower part 2b of the support column 2 or the cement anchor 22 to the ground surface. Therefore, it is not necessary to add a clamp or a cable to connect between the brake element 8 and the lower part 2b of the support column 2 or the anchor bolt 33.

  As shown in FIG. 1 and FIGS. 7 to 11, the cross clip 9 holds a crossing portion of the first reinforcing cable 5 and the second reinforcing cable 6.

  As shown in FIGS. 7 to 11, the cross clip 9 includes a plate portion 35, a pair of U bolts 36, and a plurality of nuts 37. Four openings 35 a are formed in the plate portion 35.

  The first and second reinforcing cables 5 and 6 are sandwiched between the mountain-side U-bolt 36 and the valley-side plate portion 35, and in this state, the male thread portion 36 a of the U-bolt 36 is inserted into the opening 35 a of the plate portion 35. By inserting and fastening the nut 37 to the external thread 36a, the crossing portion of the first reinforcing cable 5 and the second reinforcing cable 6 can be held.

  In addition, a groove 35b is formed in the plate portion 35, and one of the first or second reinforcing cables 5 and 6 is held in the groove 35b.

  The coupling coil 10 is made of a wire such as a steel wire having a coil shape. As shown in FIGS. 1 and 3, the coupling coil 10 couples the wire mesh 7 with the upper cable 3, the lower cable 4, and the first and second reinforcing cables 5 and 6. Specifically, the upper cable 3, the lower cable 4, the first and second reinforcing cables 5, 6 and the wire mesh 7 are wound together with the wire mesh 7 so that the cables 3 to 6 and the wire mesh 7 are connected. Combined. The coupling coil 10 is included in the concept of the coupling portion of the present invention.

  As shown in FIGS. 3 to 6, the shackle 26 is a connecting bracket that fixes the upper cable 3, the lower cable 4, and the first and second reinforcing cables 5, 6 to the column 2.

  For example, as shown in FIGS. 6A and 6B, the shackle 26 includes a U-shaped main body portion 26a and a pin 26b having a male screw portion 26e. The pin 26b can be combined with the main body portion 26a by passing the male thread portion 26e of the pin 26b through the opening 26c of the main body portion 26a and then screwing into the female screw portion 26d.

  As shown in FIG. 3, the shackle 26 is attached to the upper part 2 a and the lower part 2 b of the column 2. Specifically, the shackle 26 is attached to the valley side attachment portion 2 c of the support 2 at the upper part 2 a of the support 2. The upper cable 3 passes through the space 26f of the shackle 26 (see FIG. 6A). In addition, ring-shaped end portions 5 b and 6 b of the first reinforcing cable 5 and the second reinforcing cable 6 are connected to the main body portion 26 a of the shackle 26. On the other hand, the shackle 26 is attached to the shackle attachment portion 21 c of the base plate 21 at the lower portion 2 b of the column 2. The lower cable 4 passes through the space 26c (see FIG. 6A) of the shackle 26. Moreover, the end portion 8 b of the brake element 8 is connected to the main body portion 26 a of the shackle 26.

  As shown in FIGS. 1 and 14 to 15, the wire grip 12 is connected to the brake element 8 among the ends of the upper cable 3, the lower cable 4, and the first and second reinforcing cables 5 and 6. The end of the ring is closed in a ring shape, and a generally distributed one is used. For example, the wire grip 12 shown in FIG. 14 and the wire grip 12 shown in FIG. 15 are the same, and the same wire grip 12 is viewed from an angle changed by 90 degrees around the axis of the cables 3 and 5. Only.

  As shown in FIGS. 14 to 15, the wire grip 12 has an opening 12d formed in the base portion 12a at both ends of the U bolt 12b, which is composed of a base portion 12a, a U bolt 12b, and a nut 12c. And is fastened to the base portion 12a by a nut 12c. The base portion 12a has a plurality of protrusions 12e around the opening 12d. In the wire grip 12, a portion where the cable end portions overlapped when the ends of the cables 3 to 6 are closed in a ring shape is sandwiched between the base portion 12a and the U bolt 12b.

  Moreover, the rock fall prevention fence 1 of 1st Embodiment is also the side end cable 23, the side cable 24, and the mountain side cable 25 other than said cables 3-6 as FIG. 1-2 shows. And have.

  As shown in FIG. 1 and FIG. 4, the side end cable 23 is routed between the upper part 2 a and the lower part 2 b of the support column 2 located at both left and right ends, and the side end part of the wire mesh 7 is attached. Specifically, the ring-shaped end portion 23a on the upper side of the side end cable 23 is connected to an eye nut 32 attached to the upper portion 2a of the column 2 as shown in FIG. On the other hand, the ring-shaped end 23 b on the lower side of the side end cable 23 is connected to a shackle 26 attached to the shackle attaching portion 21 c of the base plate 21 in the lower portion 2 b of the column 2. An intermediate portion of the side end cable 23 is inserted into an eye nut 32 provided on a side surface on the valley side of the support column 2 and held on a side surface on the valley side of the support column 2.

  The side end cable 23 and the wire mesh 7 are coupled using the above-described coupling coil 10 or the like. Thereby, both ends of the wire mesh 7 are reinforced by the connection with the side end cable 23.

  The ring-shaped end portions 23a and 23b of the side end cable 23 are formed by closing the end of the cable in a ring shape by the wire grip 12 described above.

  As shown in FIGS. 1 and 2 and FIG. 4, the side cable 24 extends from the upper part 2 a of the support column 2 located at the left and right ends toward the left and right sides, and connects the upper part 2 a of the support column 2 and the ground G. . Specifically, the ring-shaped end portion 24a on the upper side of the side cable 24 is connected via a shackle 26 attached to the side of the upper portion 2a of the column 2 as shown in FIG. A ring-shaped end 24b on the lower side of the side cable 24 is connected to an anchor bolt 33 projecting from the cement anchor 22 embedded in the ground G to the ground surface with nuts together with both ends 3a and 3b of the upper cable 3. .

  As shown in FIGS. 1 and 2 and 5, the mountain-side cable 25 extends from the upper part 2 a of each column 2 in the mountain-side direction M, and connects between the upper part 2 a of the column 2 and the slope on the mountain side. Specifically, the mountain-side ring-shaped end 25a of the mountain-side cable 25 is connected to the anchor bolt 33 of the cement anchor 22 embedded in the ground G with a nut or the like. Moreover, the ring-shaped end portion 25b on the valley side is connected to the mountain-side mounting portion 2d of the upper portion 2a of the support column 2 via a shackle 26 as shown in FIG.

(Explanation regarding dimensions of rock fall prevention fence 1)
The rock fall prevention fence 1 configured as described above is designed to receive a rock fall with a relatively large kinetic energy of about 100 KJ. The dimensions of such a falling rock prevention fence 1 for 100 KJ and each part are as follows.

  The overall height of the rockfall prevention fence 1 is about 3.3 m.

  The space | interval of the support | pillar 2 is about 6 m.

  The diameters of the upper cable 3, the lower cable 4, and the first and second reinforcing cables 5 and 6 are each about 12 mm.

  The wire mesh 7 is a high-strength wire mesh that is reinforced more than a normal rockfall prevention wire mesh. For example, a strand made of a material having a high tensile strength is used. For example, a strand having a diameter of 3.2 mm is 63 mm. A wire mesh knitted with mesh on all sides is adopted.

  The coupling coil 10 employs a high-strength coupling coil that is reinforced more than a normal coupling coil. For example, the coupling coil has a strand diameter of 4 mm, a winding number of 7 turns, an inner diameter of 40 mm, and a length of 575 mm. Is adopted. The coupling coils 10 are respectively attached to the upper cable 3 and the lower cable 4 extending in the lateral direction at a ratio of about eight between the columns 2. Further, about five coupling coils are attached to the first and second reinforcing cables 5 and 6, respectively.

(Characteristics of rock fall prevention fence of the first embodiment)
As described above, in the rockfall prevention fence 1 according to the first embodiment, the both ends of the upper cable 3 that supports the wire mesh 7, both ends of the lower cable 4, and the lower portions of the first and second reinforcing cables 5 and 6, respectively. By arranging the brake elements 8, it is possible to absorb the kinetic energy at the time of falling rock received by the wire mesh 7 by the brake elements 8 through the cables 3 to 6. And in this rock fall prevention fence 1, since all the brake elements 8 are installed in the vicinity of the ground G in such a structure, construction of the rock fall prevention fence 1 is easy. Specifically, each brake element 8 is provided between the both ends 3a and 3b of the upper cable 3 and the ground G (specifically, the anchor bolt 33 protruding from the cement anchor 22), and both ends 4a of the lower cable 4. 4b and the ground G (specifically, the anchor bolt 33 protruding from the cement anchor 22), and the lower portions 5a and 6a of the first and second reinforcing cables 5 and 6 and the ground G (specifically, A shackle 26) attached to the base plate 21 fixed to the cement anchor 22 is provided. This eliminates the need to climb the upper portion 2a of the support column 2 and attach the brake element 8, and the construction becomes very easy.

  In addition, in this structure, the brake element 8 can be greatly reduced because it is a simple structure in which the brake element 8 is simply attached to both end portions 3a, 3b, 4a and 4b of the upper cable 3 and the lower cable 4, respectively. is there.

  Moreover, the brake element 8 in 1st Embodiment absorbs the kinetic energy at the time of falling rocks using the friction between the cable part 27 and the plate part 28, and the upper limit of the kinetic energy which can be absorbed is previously set. It is a set inexpensive structure. Even the brake element 8 having an inexpensive structure in which such absorbable kinetic energy is set in advance can be replaced with the brake element 8 set to another upper limit value by being installed in the vicinity of the ground G. It can be done easily. Further, the work of replacing the old brake element 8 with a new one can be easily performed.

  Furthermore, in this rock fall prevention fence 1, since it is possible to receive the kinetic energy of a rock fall by the whole rock fall prevention fence 1, the rock fall of comparatively big kinetic energy can be received with a simple structure. Specifically, the upper cable 3, the lower cable 4, and the wire mesh 7 that are installed so as to cross all of the plurality of columns 2, and the first and the second installed on the diagonal lines CL <b> 1 to CL <b> 4 between the columns 2. The kinetic energy of falling rocks can be absorbed by the second reinforcing cables 5 and 6 and the brake elements 8 attached to the cables 3 to 6. Therefore, the amount of deflection of the rock fall prevention fence 1 can be suppressed to be small. As a result, even if the falling rock prevention fence is installed on the mountain side at a distance greater than the amount of deflection from the road, etc., the distance to be shifted to the mountain side can be reduced, facilitating the transportation of materials and the construction of the falling rock prevention fence. .

  In particular, if the rock fall prevention fence 1 configured as described above is used, it is possible to reduce the amount of deflection to less than 3 m even if it receives rock fall having a kinetic energy of 100 kJ or less. It can be installed at a distance within 3m. As a result, it is possible to carry materials and to construct a rockfall prevention fence using a vehicle-mounted crane (for example, UNIC (registered trademark)) attached to a truck or the like.

  Moreover, in the rock fall prevention fence 1 of 1st Embodiment, when the kinetic energy of rock fall acts on the upper cable 3, the lower cable 4, or the 1st and 2nd reinforcement cables 5, 6, these cables 3-6 and the ground The first end portion 8a and the second end portion 8b of the brake element 8 are pulled between the first end portion 8a and the second end portion 8b. By stretching with resistance between them, it is possible to absorb the kinetic energy of falling rocks. As a result, breakage or the like of these cables 3 to 6 can be prevented.

  Further, in the rock fall prevention fence 1 of the first embodiment, the first reinforcement cable 5 and the second reinforcement cable 6 that constitute the reinforcement cable are arranged so as to cross between the columns 2, so that the reinforcement is provided between the columns 2. Falling rocks can be received more reliably than when cables are routed in parallel in the lateral direction, and falling rocks can be prevented from penetrating to the valley side. In addition, the kinetic energy of falling rocks is distributed to both the first reinforcing cable 5 and the second reinforcing cable 6 via the cross clip 9, and the kinetic energy is absorbed by the brake elements 8 attached to the cables 5 and 6, respectively. It becomes possible.

  Furthermore, in the rockfall prevention fence 1 of the first embodiment, the wire mesh 7 is connected to the upper cable 3, the lower cable 4 and the first and second reinforcing cables 5, 6 by the coiled coupling coil 10. When 7 receives a rock fall, its kinetic energy is reliably distributed to these cables 3-6 via the coupling coil 10, and is absorbed by the brake element 8 attached to each cable 3-6, respectively. With a simple structure, it is possible to receive rocks with relatively large kinetic energy.

(Second Embodiment)
In said 1st Embodiment, although the 1st reinforcement cable 5 and the 2nd reinforcement cable 6 are arrange | positioned crossing on diagonal line CL1-CL4, this invention is not limited to this, Diagonal line CL1-. Although passing over CL4, the cables 5 and 6 may be folded and arranged at the diagonal intermediate point P without crossing, and the folded portions may be connected by the holding ring 41.

  Specifically, as in the second embodiment shown in FIGS. 16 to 17, the first reinforcing cable 5 extends from the lower portion 2b of the support column 2 to the diagonal intermediate point P along the diagonal line CL1, and the diagonal intermediate point thereof. It is routed so that it is folded at P and extends to the upper part 2a of the column 2 through the diagonal line CL4. On the other hand, the second reinforcing cable 6 is located diagonally from the lower part 2b of the column 2 adjacent to the column 2 where the first reinforcing cable 5 is routed along the diagonal line CL3 at a position facing the first reinforcement cable 5. It extends to the point P, is folded at the diagonal intermediate point P, and is routed so as to extend to the upper part 2a of the column 2 through the diagonal line CL2.

  The lower ends 5a and 6a of the first and second reinforcing cables 5 and 6 are connected to the lower part 2b of the support column 2 (specifically, the shackle attached to the base plate 21) via the brake element 8, as in the first embodiment. 26), and the upper end portions 5b and 6b are respectively attached to the upper portion 2a of the support column 2 (specifically, the shackle 26 attached to the valley side attaching portion 2c). The lower ends 5a and 6a of the first and second reinforcing cables 5 and 6 are ring-shaped by being closed by the wire grip 12 (see FIGS. 14 to 15).

  The holding ring 41 holds the first reinforcing cable 5 and the second reinforcing cable 6 at the diagonal intermediate point P by bundling the folded portions 5 c and 6 c of the first and second reinforcing cables 5 and 6.

  As shown in FIG. 17, the holding ring 41 is formed by bending a main body portion 42 made of a wire or the like into a ring shape, and folding back portions 5 c of the first and second reinforcing cables 5, 6 into the inner space 44. 6c is bundled and held. The both ends 42a and 42b of the main body 42 are connected by the connecting portion 43, so that the holding ring 41 has a ring shape.

  In the second embodiment, the first reinforcing cable 5 and the second reinforcing cable 6 that extend diagonally between the columns 2 are folded back at the diagonal middle point P so that they face each other, and the folded portion is the holding ring 41. Therefore, the falling rocks can be received more securely than the case where the reinforcing cables are routed in parallel in the lateral direction between the support columns 2, and the falling rocks can be prevented from penetrating to the valley side. In addition, the kinetic energy of falling rocks is distributed to both the first reinforcing cable 5 and the second reinforcing cable 6 via the holding ring 41, and the kinetic energy is absorbed by the brake elements 8 attached to the cables 5 and 6, respectively. It is possible.

  In the above first and second embodiments, the brake element 8 using the friction brake between the cable portion 27 and the plate portion 28 has been described as an example of the shock absorber of the present invention. However, the present invention is not limited to this, and various types of shock absorbers can be employed as long as they can absorb the kinetic energy of falling rocks acting on the cables 3 to 6.

DESCRIPTION OF SYMBOLS 1 Falling rock prevention fence 2 Support | pillar 3 Upper cable 4 Lower cable 5 1st reinforcement cable 6 2nd reinforcement cable 7 Wire mesh 8 Brake element (buffer)
9 Cross grip 10 Coupling coil (joining part)
CL1, CL2, CL3, CL4 Diagonal line P Diagonal intermediate point G Ground M Mountain side direction V Valley side direction

Claims (4)

A plurality of support columns standing at intervals, and
A wire mesh that covers between the plurality of support columns and receives rockfalls;
An upper cable supporting the upper part of the wire mesh;
A lower cable supporting the lower part of the wire mesh;
A reinforcing cable that reinforces the wire mesh between the struts;
A coupling portion for coupling the wire mesh to the upper cable, the lower cable, and the reinforcing cable;
A shock absorber that absorbs kinetic energy of the falling rocks acting on the upper cable, the lower cable, and the reinforcing cable;
An anchor for fixing the upper cable, the lower cable, and the reinforcing cable to the ground, respectively .
The wire mesh is provided continuously so as to cross all the columns in the direction of alignment,
The upper cable is continuously routed while being held on all the tops of the plurality of columns, and both ends of the upper cable are fixed to the ground via the anchors ,
The lower cable is continuously routed while being held at all lower portions of the plurality of struts,
The reinforcing cable is routed so as to pass through at least a part of a diagonal line in a rectangular plane formed between the columns,
The shock absorbers are interposed between both ends of the upper cable and the ground, between both ends of the lower cable and the ground, and between a lower portion of the reinforcing cable and the ground, respectively .
The shock absorber absorbs kinetic energy of the falling rock by extending with resistance between the first end, the second end, and the first end and the second end. An absorption part,
The first end is connected to the upper cable, the lower cable or the reinforcing cable;
The second end is connected to the ground via the anchor;
Rock fall prevention fence. The reinforcing cable is
A first reinforcing cable extending on the diagonal line and extending from a lower portion of the column to an upper portion of the adjacent column;
The second reinforcing cable extending on the diagonal line and extending from the upper part of the column to the lower part of the adjacent column,
A cross clip for holding a crossing portion of the first reinforcing cable and the second reinforcing cable;
The rock fall prevention fence according to claim 1 . The reinforcing cable is
A first reinforcing cable extending on the diagonal line, folded back from the lower part of the column through a diagonal middle point and extending to the upper part of the column;
A second reinforcing cable that extends on the diagonal line at a position facing the first reinforcing cable, and is folded back from the lower part of the column adjacent to the column through a diagonal middle point and extends to the upper part of the column. And
A holding ring for holding the first reinforcing cable and the second reinforcing cable in a bundled portion of the folded first and second reinforcing cables at the diagonal intermediate point;
The rock fall prevention fence according to claim 1 . The coupling part comprises a coupling coil having a coil shape,
The upper cable, the lower cable and the reinforcing cable are wound inside the coupling coil together with the wire of the wire mesh, thereby being coupled to the wire mesh.
The rock fall prevention fence according to any one of claims 1 to 3 .

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