JP2008106450A - Impact absorbing fence - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that only received and absorbed impact energy of limited magnitude can be absorbed only by receiving the impact of a rock fall and the like through the use of only the impact absorbing performance of a guard net alone. <P>SOLUTION: Supports 1 are erected at proper intervals; upper and lower wire ropes 3 run across the supports; and ends of the wire ropes are gripped by buffering fittings 4 and 7. A net material 8 is provided in a tensioned state between the upper and lower wire ropes 3, so as to constitute the guard fence. A plurality of weight bodies 9 such as thinned wood are juxtaposed along the guard net. When the impact force of the rock fall etc. acts on the weight body 9, the weight body 9 exerts a braking force which tries to push back the impact force by its weight, so as to attenuate the impact of the rock fall. When the impact force acting on the wire ropes 3 and 5 exceeds the gripping force of the buffering fittings 4 and 7, the wire ropes 3 and 5 generate a frictional force in the buffering fitting 4, and attenuate the impact by the frictional force. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an impact absorbing fence that receives impacts such as falling rocks, slope collapses, and avalanches and absorbs the impacts.

  An impact absorbing structure has been developed to absorb the impact so that rockfalls, slope failures, avalanches, etc. will not cause significant damage to the roads and houses underneath. Structures for absorbing impacts are roughly classified into large scale and medium scale depending on the magnitude of absorbed energy. Such a shock absorbing structure, in any case, becomes a large facility due to the use of concrete foundations, high-rigid struts, large-diameter ropes, large shock absorbers, etc. The cost was high and the construction labor was also large.

  The present applicant has proposed an invention according to Japanese Patent No. 3385508 as an impact absorbing structure that does not require such extensive construction. In the present invention, struts are erected at appropriate intervals, and protective nets are arranged along the struts. The protection net has wire ropes arranged above and below the support, and at least one end of the rope is held by a shock-absorbing metal fitting that allows sliding with a tensile force exceeding the gripping force. Between the upper and lower wire ropes, a net material such as a wire net is stretched. When an impact such as falling rocks acts on this protective net, the end of the wire rope slides and stretches while rubbing the inside of the shock-absorbing bracket, and the frictional force acts as a braking force against the impact. Absorb.

  Such a structure that should be called an impact-absorbing fence absorbs impacts such as falling rocks only by the frictional force when sliding the wire rope and the elongation of the netting material. As shown, the wire mesh a and the buffer wire b are greatly deformed and sometimes are damaged. In other words, the current situation is that the large impact force may not be received, and its application is limited.

On the other hand, there is a problem of effective use of thinned wood, which is a resource of mountain forests. It has been proposed to use thinned wood as an alternative to struts and protective nets as a means of effectively utilizing the thinned wood that has been harvested without disposing it. However, in the current way of use, the amount of thinned wood consumed is not sufficient, and it has not been used effectively. In addition, since wood has a lower strength than steel, the energy absorption performance of the structure may be reduced.
Japanese Patent No. 3385508

  The problem to be solved by the present invention is that shocks such as falling rocks are absorbed only by the buffering performance of the protective net.

The shock absorbing fence according to the present invention is:
In the shock-absorbing fence in which a protective net is stretched along the struts set up at intervals,
A plurality of weights are mounted side by side along the protective net.
Further, as the weight body, metal, concrete, sandbags, etc. can be used, but wood such as thinned wood is sometimes used.
Further, a plurality of weight bodies may be connected to be bent at the connecting portion.
Further, a groove-shaped slit may be formed on the weight body, and when an impact force is applied, the slit may be bent or broken.
In addition, the protective net may be composed of a wire rope passed up and down and a net member stretched between the wire ropes.

(A) Since the amount of energy absorbed is the product of the weight of the object and the amount of movement, the shock absorbing fence according to the present invention adds the weight of the weight to the weight of the protective net. The weight of the weight acts like a braking force against an impact and absorbs, that is, attenuates an impact such as a falling rock, thereby greatly improving the impact absorbing performance.
(B) If the weight is simply suspended from the net to increase the weight as described above, the upper part of the net may sag, and falling rocks may spill from the net to the opposite side. To prevent this, it is necessary to move the entire fence while wrapping stones. For this purpose, it is necessary to make the entire net heavy, and by arranging a columnar (bar-shaped) body over the entire net, the entire weight of the net can be increased. With this columnar shape, it is easy to mount and the interval can be easily maintained.
(C) By making the connecting portion connecting the upper and lower ropes and the columnar weight members movable, energy can be absorbed even in this portion.
(D) The weight adjustment of the protective net can be easily performed by increasing or decreasing the number of weights installed. As a result, the number of attachments can be determined according to the expected amount of required energy absorption and the required weight can be applied, and the amount of deformation at the time of impact can be limited.
(E) Since a shock such as falling rocks can be directly received by a weight body such as wood, the impact force that directly acts on the protective net is reduced, and damage to the protective net can be avoided.
(F) By using wood as a weight, it is possible to effectively use a large amount of thinned wood as a resource, and it is easy to replace when damaged.
(G) By connecting a plurality of weights and making them bendable at the connecting part, the weights bend and receive shocks such as falling rocks, and the weights themselves are less damaged and the impacts are more effective. Can be absorbed.
(H) By forming a groove-like slit in the weight body, the breaking strength of the weight body can be controlled such that the weight body is broken by a certain impact force such as falling rocks. Thereby, energy absorption performance can be grasped quantitatively. When it bends or breaks, it absorbs impact energy and can further increase the absorbency.
(I) The original deformation performance of the protective net is not hindered by bending or bending of the weight body. In other words, it does not adversely affect the original shock absorbing performance of the protective net.

  The shock absorbing fence according to the present invention achieves a significant improvement in shock absorbing performance by arranging a plurality of weight materials such as wood along the protective net.

<1> Overall Configuration The shock-absorbing fence according to the present invention includes a support column 1 that is provided upright and separated as appropriate, a protection net disposed along the support column, and a weight body 9 provided in parallel along the protection net. Consists of. Various types and materials of the support column 1 and the protection net have been used so far. The support column 1 is a tilt type that tilts and absorbs the impact force when an impact is applied, or an embedded impact force in the foundation. Any non-tilting type that does not tilt even if the action is applied can be adopted. Various types of protective nets can be used, such as a rope net or a combination of ropes 3 and 5 and a net member 8 such as a wire net.

<2> Columns FIG. 1 and FIG. 2 show a first embodiment of the present invention, in which an inclined type column is adopted as the column 1, and a plurality of pipe-shaped columns 1 are appropriately used. Standing apart at intervals. Wire ropes 2 are arranged in each support column 1, and these wire ropes 2 are held at the upper ends of the support columns 1 near the ground surface by buffer metal fittings 4 that hold them. When a lateral load acts on the support column 1 and exceeds the gripping force of the shock-absorbing bracket 4, the wire rope 2 slides inside the shock-absorbing bracket 4, and the frictional force is absorbed as a braking force against the load. However, the support column 1 is inclined.

<3> Retention of struts Wire ropes 3 that extend further outward than struts 1 at both left and right ends are gripped with a predetermined force by buffer fittings 4 that are fixed to the ground portion of anchors embedded in natural ground. (FIG. 3) The end of the wire rope 3 extends beyond the shock-absorbing metal fitting 4, and when the wire rope 3 extends, the end of the wire rope 3 exceeds the gripping force of the shock-absorbing metal fitting 4 and slides toward the support column 1 side. . Moreover, the wire rope 5 connected to the upper end of each support | pillar 1 is projected to the mountain side, and is being fixed to the buffer metal fitting 7 fixed to the ground of the anchor 6 embed | buried in the natural ground. The end of the wire rope 5 extends beyond the shock-absorbing bracket 7, and when a load in a direction tilting toward the trough is applied to the support column 1, the wire rope 5 slides in the resist against the gripping force of the shock-absorbing bracket 7. Move to the support 1 side. The impact load is attenuated by the friction force at that time.

<4> Protective net Wire ropes 3 are respectively passed to the upper and lower ends of the support column 1. At least one of the ends of the wire rope 3 is gripped by a buffer fitting 4 attached to the support 1. (FIG. 4) The shock-absorbing metal fitting 4 grips the wire rope 3 with a force clamped between them, but when a force greater than the gripping force acts as a tensile force, the shock-absorbing metal fitting 3 resists the pinching force of the wire rope 3 Slide in 4. The tensile force is attenuated by the friction force at that time, and the load is absorbed. In the figure, one or both ends of the upper and lower wire ropes 3 are gripped by the shock-absorbing metal fittings 4, and when a tensile force acts upon receiving a load, the direction in which the wire rope 3 receives the load exceeding the gripping force of the shock-absorbing metal fittings 4. The impact load is attenuated by the friction force. In the embodiment, a protection net composed of wire ropes 3 and 5 and a net member 8 is used, and the net member 8 is stretched between the upper and lower wire ropes 3. The net member 8 may be a wire net or a synthetic resin net member.

<5> Weight body A plurality of weight bodies 9 are arranged along the protective net. The weights 9 are for adding the weight of the weights 9 to the protective net, and the number of the weights 9 is determined according to the expected impact force. The action of the weight body 9 is not used, for example, to connect and integrate double parallelly arranged wire ropes, but adds its weight to a single protective net and It acts as a braking action that tries to push back by the weight, and attenuates the impact itself. In this embodiment, the weight body 9 is arranged on the mountain side of the net member 8. As the weight body 9, various materials can be considered, but various materials such as thinned wood, metal, concrete, etc. can be used. In the embodiment, thinned wood is used. . Various means for attaching the weight body 9 are conceivable, but a wire or the like can be passed up and down, and this can be directly connected to the wire rope 3 or net member 8 of the protective net.

<6> Shock Absorbing Action When there is a falling rock or the like and the falling rock collides with the fence, a braking force is applied to push back the falling rock or the like by the weight of the weight body 9 integrated with the protective net.
The braking force attenuates the impact energy, that is, absorbs it, and weakens the impact force acting on the protective net itself and the column.
Further, when falling rocks or the like directly collide with the weight body 9 instead of the protection net, most of the impact is received by the weight body 9, and the risk of the protection net being damaged by the impact is reduced. (Fig. 6)
If the weight body 9 is wood such as thinned wood, even if it is damaged by impact, the performance of the fence itself is not affected, and the weight body 9 can be easily replaced and is inexpensive.
If the impact of falling rocks and the like absorbed by the weight body 9 acts as a tensile force on the wire ropes 3 and 5 and the net member 8 of the protective net and exceeds the gripping force of the buffer metal fittings 4 and 7, the wire rope 3 5 slides in the buffer metal fittings 4 and 7 and moves. The frictional force at that time acts as a braking force and attenuates impact energy such as falling rocks.
As described above, the shock absorbing fence according to the present invention achieves an impact absorbing effect that is not found in conventional fences by improving the impact energy attenuation effect by adding weight and the synergistic effect of the original shock energy attenuation effect of the fence. To do.

<7> Others The number of weights 9 determines the weight of the entire fence according to the expected impact energy, and determines the number of installations according to the weight.
The weights 9 can be arranged along either the mountain side or the valley side of the protective net, and can also be arranged on both sides thereof.
In addition, even when the weight body 9 is broken or broken, the impact can be absorbed more, and groove-shaped slits are put in advance in the width direction of the thinned wood or the columnar weight body of concrete, The breaking strength of the weight body can be controlled by breaking at the slit portion by impact. Thereby, the energy absorption performance can be grasped quantitatively.
Further, by bending, bending, or breaking these weights, the deformation of the protective net itself is not hindered, and the net impact absorption performance is not adversely affected.

  FIG. 5 shows another embodiment of the weight body 9 in which the weight body 9 made of thinned material is laid in the horizontal direction. In FIG. 7, the weight body 9 is divided into two upper and lower stages and connected, and this is arranged on the valley side of the net member 8 and between the upper and lower wire ropes 3. When an impact such as falling rocks acts, it bends at the connecting portion and is received so as to wrap the falling rocks, and the impact can be absorbed better.

  FIG. 8 shows one attachment means of the thinning material that is the weight body 9, and a part of the side surface of the thinning material is cut out and attached so that the upper and lower wire ropes 3 are fitted therein. is there.

  FIG. 9 shows another attachment means of the thinned material that is the weight body 9, and penetrates the hole 10 in the center line direction of the thinned material, and passes the wire 11 through the hole 10. It is attached to the upper and lower wire ropes 3 with a cross clip 12.

  FIG. 10 and FIG. 11 show other attachment means of the weight body 9, and a U-shaped metal fitting 13 is attached to the end portions of the upper and lower buffer wire members 3. You may make it grab up and down.

  FIGS. 12 to 14 show other attachment means for the weight body 9, and a C-shaped bracket 14 that can be suspended from the upper and lower wire ropes 3 is attached to the weight body 14. 9 is rotatably attached. When a falling rock hits, the weight body 9 rotates and can absorb the impact further.

It is a perspective view of one Example of an impact-absorbing fence. It is a front view of the fence shown in FIG. It is a side view of the upper end part of a support | pillar. It is a side view of the state which let the wire rope pass through the buffer metal fitting. It is a front view of the other Example of a fence. It is a side view in the state where a falling rock collided. It is a side view of the other Example in the state where the falling rock collided. It is a perspective view of one attachment means of a weight body. It is a perspective view of the other attachment means of a weight body. It is a perspective view of the other attachment means of a weight body. It is a top view of the attachment means shown in FIG. It is a perspective view of the other attachment means of a weight body. It is a side view of the attachment means of FIG. It is a top view of the attachment means of FIG. It is an impact absorption figure of the conventional simple impact-absorbing fence.

Explanation of symbols

1: Strut 2: Wire rope 3: Wire rope 4: Buffer metal fitting 5: Wire rope 6: Anchor 7: Buffer metal fitting 8: Net material 9: Weight body

Claims (5)

In the shock-absorbing fence in which a protective net is stretched along the struts set up at intervals,
A shock-absorbing fence in which multiple weights are mounted side by side along a protective net.   2. The shock absorbing fence according to claim 1, wherein wood is used as the weight body.   2. The shock absorbing fence according to claim 1, wherein a plurality of weight bodies are connected to be bent at the connecting portion.   2. The shock absorbing fence according to claim 1, wherein a groove-shaped slit is formed on the weight body, and when the impact force is applied, the slit is bent or broken at the slit portion.   2. The shock absorbing fence according to claim 1, wherein the protective net is composed of a wire rope extending up and down and a net member stretched between the wire ropes.

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