JP2012237145A - Support structure and guard fence - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an erection angle and a fence height of a receiving surface of a guard net to be kept constant even if there are undulations on a slope, and allow a support structure to exhibit steady damping performance.SOLUTION: An axial force absorber 20 is composed of plural resilient rods 21, a deformation guide 30 is composed of a rigid material, and the axial force acting on the deformation guide 30 is guided to the axial force absorber 20 via connection members 12, 13 and 14.

Description

  The present invention relates to an energy absorption technique suitable for absorbing a dynamic load such as falling rocks, landslide and avalanche, or a static load such as snow pressure (hereinafter referred to as “energy”). More specifically, the present invention can effectively absorb energy. The present invention relates to a strut structure and a protective fence.

  Generally, the struts in this type of guard fence are made of rigid materials such as steel and concrete-filled steel pipes to resist bending and axial force. Not only that, but installation work on site also relies on heavy machinery, which has problems with workability.

Patent Document 1 discloses a strut structure in which a high-rigidity main strut, a high-rigidity oblique strut, and a plurality of connecting ropes are combined, and an avalanche protective fence using the strut structure.
This strut structure is configured by crossing both struts in an X shape, fixing the base ends of the slant struts to the slope with ground anchors, and connecting the free ends and the base ends of both struts with connecting ropes. The upper and lower sides of the protective net are fixed to the upper part of the main support and the lower part of the oblique support.
It has a structure that counteracts the snow load acting on the protective net with the compression strength of both struts and the tension of the connecting rope.

  In order to solve the problems included in the protective fence disclosed in Patent Document 1, the applicant has a strut structure in which the main strut and the oblique strut are composed of a plurality of flexible bars, and protection using the strut structure. A fence was proposed first (Patent Document 2).

JP 2007-63831 A JP 2010-255648 A

The guard fence described in the above-mentioned patent document 1 has the following problems.
(1) The main strut and the oblique strut have high compressive strength but do not have a load absorbing function.
Therefore, when an axial force exceeding the assumption is applied to the main support column and the oblique support column, the support column suddenly buckles and loses the fence function.
(2) When a load acts on the protective fence at high speed like avalanches or falling rocks or locally, not only compression but also bending and twisting are applied to each column.
Since the support structure cannot cope with bending and twisting, the stable balance of the support structure is likely to be lost. If the balance is lost, the support structure will be destroyed suddenly.
(3) The main struts and the base ends of the slant struts constituting the strut structure are allowed to rotate along the slope inclination direction, but are restricted from rotating in a direction perpendicular to the slope inclination direction.
For this reason, when a large force acts on the column structure in a direction orthogonal to the slope of the slope, the pivotal support portion at the base end of both columns is destroyed.
(4) When some of the support columns are destroyed due to the factors (1) to (3) described above, the destruction of the support structure spreads in a chain and functions as a whole protective fence. I will lose.
(5) In order to recover the destroyed support structure, it is necessary to replace the set of support structures newly, which requires a lot of time, labor and cost.

The guard fence described in Patent Document 2 has the following points to be improved.
(1) In order to distribute the load properly between the main struts and the diagonal struts, the balance of elasticity and hardness of each strut, the crossing angle of each strut, the length of the connecting rope, and the installation distance at the bottom of both struts are designed models It is important to install on the street.
Since the mountain slope is not flat and has many undulations, it is difficult to install the strut structure according to the design model described above.
For this reason, if the column structure is installed in response to the undulations at each installation site at the expense of the design model, the installation distance between the base ends of both columns and the standing angle of the protection net will be uneven, and the protection net will be particularly large. There is an inconvenience that the height of the fence is lowered at the inclined part.
(2) The strut structure has a structure in which the share ratio of the damping action by the main strut and the oblique strut is determined.
As described above, when the crossing angle and installation interval of both columns fluctuate due to the influence of undulations on the slope, the share of damping action changes in units of each column structure, and the damping performance of each column structure is steady. Difficult to calculate.
In particular, if the damping balance of each strut that is elastically deformed is lost, not only the original damping performance cannot be demonstrated, but the fence height is deformed extremely low at the time of the first reception, and it corresponds to the subsequent reception Sometimes it is not possible.
(3) The dimensional balance of the strut structure is designed with some margin, but if the dimensional balance of the strut structure exceeds the allowable value, the energy absorption performance will be affected and stable performance will be demonstrated. Can not.
(4) In order to avoid the influence of undulations on the slope and balance the dimensions of the strut structure, it is necessary to individually design the dimensions of each material that constitutes the strut structure, which complicates the processing and assembly of the materials. It becomes.
(5) When assembling the strut structure, it is difficult to assemble because both struts bend.

The present invention has been made in view of the above points, and an object thereof is to provide at least one strut structure and an impact absorbing fence.
<1> The strut structure must be capable of steadily exhibiting damping performance.
<2> Keeping the standing angle of the receiving surface of the protective net and the height of the fence constant even at sites where the undulations of the slope are changing.
<3> Efficiently absorb energy acting on the receiving surface of the protective net while avoiding destruction of the strut structure.
<4> Do not break the column structure even if it is bent or twisted.
<5> Excellent compatibility with not only static loads such as snow pressure, but also dynamic loads such as falling rocks and avalanches.
<6> The strut structure has a self-restoring property and is excellent in the repairability of the shock absorbing fence.
<7> To improve the workability and reduce the cost associated with the weight reduction of the shock absorbing material.

In the first invention of the present application, an axial force absorber that is fixedly tilted with a proximal end fixed, and an axial force absorber that intersects with the axial force absorber and that is tilted with a proximal end fixed. A shock absorber comprising: a deformation derivative; and a connecting member that connects the axial force absorber and each free end of the deformation derivative, and a connecting material that connects the free end of each of the axial force absorber and the deformation derivative and a slope. A strut structure of a fence, wherein the axial force absorber is composed of a plurality of bullets constrained at both ends, the deformation derivative is composed of a rigid material, and the axial force acting on the deformation derivative is It is configured to be guided to the axial force absorber through a connecting material.
A second invention of the present application is characterized in that, in the first invention, a length adjusting tool is interposed in a part of the connecting material so that the length of the connecting material can be adjusted.
According to a third invention of the present application, in the first or second invention, the free ends of the plurality of elastic rods are connected by a binding plate, and the installation position of the binding plate can be displaced along the elastic rod. It is characterized by that.
A fourth invention of the present application is characterized in that, in the second invention, the installation position of the binding plate can be displaced along the elastic rod by a nut screwed into the elastic rod.
A fifth invention of the present application is characterized in that, in any one of the first to fourth inventions, an anchor for respectively fixing the axial force absorber and the base end of the deformation derivative is provided.

A sixth invention of the present application is an impact-absorbing fence comprising a plurality of support structures standing upright apart from each other and a protective net stretched between the support structures. The base end of the axial force absorber is fixed to the valley side slope, and the base end of the deformed derivative arranged so as to cross the axial force absorber is fixed to the mountain side slope. The support structure is erected, and the upper side of the protective net is attached to the free end of the axial force absorber that constitutes each of the adjacent support structures, and is disposed on the mountain-side slope.
According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the energy acting on the protective net is dispersed in the intersecting axial force absorber and the deformation derivative, and the axial force generated in the deformation derivative is transmitted to the axial force absorber. As possible, the axial force absorber and each free end of the deformation derivative, and the free end of each of the axial force absorber and the deformation derivative and the slope are connected by a connecting material, respectively. To do.
The eighth invention of the present application is characterized in that, in the sixth or seventh invention, the lower side of the protective net is attached to the base end of the modified derivative constituting each of the support structure.
A ninth invention of the present application is characterized in that, in the sixth or seventh invention, the lower side of the protective net is fixed to the mountain side slope.

  The “energy” in the present invention includes not only dynamic loads such as falling rocks and avalanches but also kinetic energy and potential energy due to static loads such as snow pressure.

  The “elastic deformation” in the present invention includes compressive deformation in the longitudinal direction of the axial force absorber, torsional deformation with the longitudinal direction as an axis, and bending deformation in all other directions.

According to the present invention, at least one of the following effects can be obtained.
(1) A strut structure formed by combining a flexible axial force absorber and a rigid deformed derivative serves as a member that transmits energy (deformed derivative, etc.) and a member that absorbs energy (axial force absorber). Is clear.
Therefore, each strut structure can constantly exhibit damping performance even if it is affected by the undulation of the slope.
(2) Since the roles of the axial force absorber and the deformation derivative are clear, it is possible to accurately calculate the amount of energy absorbed as the entire support structure, and to easily select a member according to the role.
(3) Even if there are undulations on the slope, the standing angle of the receiving surface of the protective net and the height of the fence can be kept constant by adjusting the total length of the connecting material with the length adjuster interposed in the connecting material. .
(4) At the free end of the axial force absorber, the hanging height of the upper side of the protective net is arbitrarily adjusted, so that the installation distance between the axial force absorber and the deformation derivative is kept constant, while the receiving surface of the protective net is The standing angle and the fence height can be kept more accurate.
(5) It is possible to efficiently absorb energy acting on the receiving surface of the protective net by allowing the axial force absorber to be elastically deformed while maintaining the uprightness and allowing the absorption.
(6) Since the axial force absorber exhibits a cushion function, it is possible to avoid the destruction of the deformation derivative and the plurality of connecting members, and thus it is possible to avoid the sudden loss of function of the shock absorbing fence.
(7) The structural members of the support structure can be simplified, and the manufacturing cost can be greatly reduced.
(8) By constituting the axial force absorber with a plurality of bullets, elastic deformation is possible in all directions. Therefore, it is possible to flexibly follow the deformation without concentrating excessive stress on the base end of the elastic shell against deformation or twist caused by an unexpected load.
(9) Axial force absorbers and deformation derivatives constituting the strut structure can be reduced in weight, so that the strut structure can be transported and assembled on site, improving workability and reducing costs. be able to.
(10) Since the support structure has a self-restoring property, it is excellent in the repairability of the shock absorbing fence.
(11) Sufficient energy absorption performance can be exhibited not only for static loads such as snow cover but also for dynamic loads such as falling rocks and avalanches.

The perspective view of the shock absorption fence which abbreviate | omitted the part which concerns on this invention Side view of support structure according to embodiment 1 Model diagram of the strut structure viewed from the sloped valley side Enlarged view of the proximal end of the axial force absorber Enlarged view of the proximal end of the modified derivative Model diagram of ideal strut structure It is explanatory drawing of the method of installing a column structure on a slope with ups and downs, (A) is a model figure of a column structure when installing on a slope that falls backward, (B) is a column when installing on a slope that rises backward Model diagram of structure Model diagram of ideal strut structure with extra length It is explanatory drawing of the method of installing a support structure on a slope with ups and downs, (A) is a model diagram of the support structure when installed on a slope that falls back, (B) is a case of installing on a slope that rises backward Model diagram of support structure Model diagram of shock absorbing fence during energy action Side view of support structure according to embodiment 3

  Embodiments of the present invention will be described below with reference to the drawings.

<1> Shock Absorbing Fence FIG. 1 is a perspective view of the shock absorbing fence of the present invention, FIG. 2 is a side view of the strut structure 10, and FIG. 3 is a model diagram of the strut structure 10 viewed from the inclined valley side. Indicates.

The shock absorbing fence according to the present invention includes a plurality of support structures 10 provided at an interval on the slope 11 and the like, and a protection net 40 stretched between the support structures 10.
In FIG. 1, reference numeral 18 denotes one or a plurality of holding ropes stretched between the support structure 10 at the end and the inclined surface 11.

<2> Column structure The column structure 10 is a structure having both the function of absorbing energy received by the receiving surface 41 and the column function, and the base end is fixed to the valley-side inclined surface so as to be rotatable on the inclined surface 11. An axial force absorber 20 provided, a deformation derivative 30 which is arranged so as to intersect with the axial force absorber 20, is fixed to the slope on the mountain side, and is rotatably erected on the slope 11, and the axial force absorber 20. And the non-stretchable first to third members respectively connecting the free end and the base end (slope 11) of the axial force absorber 20 and the deformable derivative 30. Connecting members 12-14.

The crossing angle of the axial force absorber 20 and the deformation derivative 30 and the total length of each of the connecting members 12 to 14 transmit energy acting on the receiving surface 41 in a distributed manner to the axial force absorber 30 and each of the connecting members 12 to 14. However, the axial force absorber 20 is related to act as an axial force.
Hereinafter, details of the support structure 10 will be described in detail.

<2.1> Axial force absorber The axial force absorber 20 is an elastic structure having a damper function that absorbs energy acting on the receiving surface 41 by compressive deformation, and a plurality of elastic shells that converge at both ends. 21.
In this example, the case where the axial force absorber 20 is constituted by two bullets 21 and 21 will be described. However, the number of bullets 21 may be appropriate, and may be one or three or more. .
For example, a metal material such as a bar steel or spring steel, or an elastic material such as a resin can be used as the material of the bomb 21.

  Screws are formed on the peripheral surface of the bullet urn 21 so that the suspension height of the upper side of the protective net 40 can be adjusted.

<2.1.1> Structure on the Base End Side of the Axial Force Absorber As shown in FIGS. 2 to 4, the base end of the elastic rod 21 is rotatable to the support bracket 24 of the ground plate 23 by the support shaft 22. It is pivotally supported, and an anchor 25 is driven on the ground plate 23 and fixed to the slope 11.

<2.1.2> Structure of Free End of Axial Force Absorber As shown in FIGS. 2 and 3, a pair of upper and lower nuts 26, 26 are screwed to the free end of each elastic rod 21.
Between the free ends of the plurality of bullets 21, a pair of upper and lower bundling plates 27, 27 are disposed so as to bind the free ends of the two bullets 21, 21 so that they cannot be separated.

The spacer tube 28 and the bundling plates 27, 27, which are externally mounted on the upper part of each of the bullets 21, can be slid while maintaining the restraint with respect to the bullets 21, and the screwing positions of the pair of upper and lower nuts 26, 26 are set. By moving up and down, the installation position of the binding plates 27 and 27 can be adjusted to an arbitrary height along the elastic rod 21.
Each of the binding plates 27 and 27 and the tube 28 are separate bodies, but the lower binding plate 27 and the tube 28 may have an integrated structure.

  An end of the upper rope 15 for hanging the protective net 40 is moored in an inseparable manner on the pipe 28 at the upper part of each of the bullets 21, and the first and third connecting members 12, 14 are attached to the binding plate 27. The upper ends of each are moored inseparably.

  The means for adjusting the suspension height of the upper side of the protective net 40 is not limited to the nuts 26, 26, and the binding plate 27 can be positioned at any position of the elastic rod 21 such as pinning or welding. Known positioning means can be applied.

<2.2> Deformation Derivative The deformation derivative 30 intersects with the deformation derivative 30 in a form located between the bullets 21 and 21 constituting the axial force absorber 20.
The deformation derivative 30 is a rigid material that functions to induce the energy acting on the receiving surface 41 as the axial force of the axial force absorber 20, and is formed of, for example, a steel pipe.
In order to exhibit the function, the compressive strength of the deformation derivative 30 is larger than that of the axial force absorber 20.

<2.2.1> Pivot Support Structure of Deformation Derivative Base As shown in FIG. 2, the base end of the deformation derivative 30 is pivotally supported by the support bracket 33 of the ground plate 32 by the support shaft 31. An anchor 34 is placed on the ground plate 32 and fixed to the slope 11.

  As shown in FIG. 5 in an enlarged manner, the lower end of the third connecting member 14 is connected to the front connection piece 32a formed upright on the ground plate 32, and each side connection formed upright in the diagonal direction. The lower ropes 16 and 16 connected to the lower side of the protective net 40 are connected to the pieces 32b and 32b.

<2.2.2> Free end of deformation derivative As shown in FIG. 2, a protrusion 35 for latching is provided at the free end of the deformation derivative 30 and is anchored to the free end of the deformation derivative 30. The loop portions at one end of the first and second connecting members 12 and 13 can be positioned and connected.
The anchoring means of the first and second connecting members 12 and 13 is not limited to the protrusion 35, and a known anchoring means can be applied.

<2.3> Connecting Material Each of the connecting materials 12 to 14 can be made of, for example, a steel or fiber rope, a steel rod, a steel plate or the like excellent in tensile strength.
The first connecting member 12 is connected between the free end of the axial force absorber 20 and the free end of the deformation derivative 30, and the second connecting member 13 is a base of the free end of the deformable derivative 30 and the axial force absorber 20. The third connecting member 14 connects the free end of the deformation derivative 30 and the base end of the deformation derivative 30.
In addition, you may comprise the 1st-3rd connection materials 12-14 by one continuous member.

  In the present invention, since the axial force absorber 20 has a buffer function, the tension load on each of the connecting members 12 to 14 and the load on each of the anchors 25 and 34 are reduced as compared with the related art.

In the present invention, a case will be described in which a length adjusting tool 17 capable of adjusting the length in the field is interposed in the middle of the second connecting member 13.
The length adjuster 17 may be a known adjuster that can withstand tension, in addition to a turnbuckle or the like.

<3> Protective Net The protective net 40 is a structure having a receiving surface 41 and includes, for example, a metal net, a rope net, or a known net in which these are combined.
Moreover, the protection net | network 40 may be divided | segmented into 1 span unit of the support | pillar structure 10 other than what has the full length over several spans.

The protective net 40 is disposed on the mountain side slope, and the upper side thereof is attached to the free end of the axial force absorber 20 and is suspended.
In this example, the upper side of the protective net 40 is attached to the upper rope 15 that is laid between the free ends of the axial force absorber 20, and the lower side of the protective net 40 is laid down between the base ends of the deformable derivative 30. It is attached to the rope 16.

[Assembly of shock absorbing fence]
Next, a method for assembling the shock absorbing fence will be described.

<1> Carrying in materials The column structure 10 and the protection net 40 constituting the shock absorbing fence are carried into the site.
When the material is carried in, the steel bar munitions 21 and the connecting members 12 to 14 constituting the support structure 10 are subdivided into weights that can be carried by workers, so the site is in a mountainous area. Even if there is, it is easy to carry in materials.

<2> Assembly of support structure The assembly example of the support structure 10 will be described with reference to FIGS.
After setting the grounding plates 23 and 32 to the anchors 25 and 34 driven at intervals on the slope 11, the heads of the anchors 25 and 34 are fixed with nuts.
Next, the base end of the axial force absorber 20 is pivotally supported on the lower installation plate 23 via the support shaft 22, and the base end of the deformation derivative 30 is supported on the upper installation plate 32 via the support shaft 31. Pivot.
Bundling plates 27 and 27 and a tube 28 are set on the free ends of the axial force absorber 20 crossing the deformation derivative 30, and nuts 26 and 26 are screwed on both sides thereof.
Finally, the support structure 10 is assembled by connecting the non-stretchable first to third connecting members 12 to 14 between the free ends and the base ends of the axial force absorber 20 and the deformation derivative 30. Complete.

Even if the axial force absorber 20 is slightly bent, the deformation derivative 30 is not deformed. Therefore, it is easy to assemble the support structure 10 in a three-dimensional manner by intersecting the members 20 and 30.
Furthermore, since the upright installation work of the axial force absorber 20 and the deformation derivative 30 can be performed manually, a crane or the like is not required for assembling the support structure 10.

<3> Assembling the protective net The upper rope 15 is placed between the tops of the adjacent strut structures 10, that is, between the upper portions of the axial force absorbers 20. The lower rope 16 is placed horizontally between the lower portions of the adjacent strut structures 10, that is, between the ground plates 32 at the base end of the deformation derivative 30.
The upper and lower sides of the protective net 40 are attached so as not to be separated between the upper and lower ropes 15 and 16, and the assembly of the shock absorbing fence is completed.

In FIG. 2 showing the completed shock absorbing fence, the weight of the axial force absorber 20 tilting toward the slope mountain side is dispersed and supported by the slope 11 and the rigid deformation derivative 30 via the connecting members 12 and 13.
The weight of the deformation derivative 30 that tilts toward the slope valley is dispersed and supported by the slope 11 and the axial force absorber 20 via the connecting members 12 and 14.
The weight of the protective net 40 is dispersed and supported on the slope 11 and the rigid deformation derivative 30 via the axial force absorber 20 and the connecting members 12 and 13.
As described above, the axial force absorber 20 and the deformation derivative 30 constituting the support structure 10 are able to maintain a stable posture with their weights balanced.

[How to deal with undulations on slopes]
In order for the shock absorbing fence to perform the original trapping function such as falling rocks, the rising angle of the receiving surface 41 of the protective net 40 is kept constant, and the height (fence height) of the receiving surface 41 of the protective net 40 is sufficient. It is required to secure it.
When the dimensional length of each member constituting the column structure 10 is a constant standard (fixed dimension), the rising angle of the receiving surface 41 (angle with respect to horizontal or vertical) and the fence height are affected by the undulation of the slope 11. Cannot be made uniform.
Therefore, in the present invention, when the support structure 10 is installed on the slope 11 with the undulations, the following method is used.

<1> Countermeasure 1
FIG. 6 shows a model diagram of the column structure 10 having an ideal dimension balance.
In the figure, the installation distance (slope distance) of the proximal ends of the axial force absorber 20 and the deformation derivative 30
Is L, the fence height of the protective net 40 is H, the total length of the first connecting member 12 is x, and the total length of the second connecting member 13 is y. A countermeasure that assumes that the total length of 30, the fence height H of the protective net 40, and the total length x of the first connecting member 12 do not change will be described.

FIG. 7A shows a state in which the slope 11 is excessively inclined at an angle of the gradient θ ₁ compared to the reference gradient in FIG. 6 and then is lowered (or forwardly raised), and FIG. Compared with the reference gradient of FIG. 6, the state is shown in a state of rising (or falling forward) after inclining in the opposite direction at an angle of gradient θ ₂ .

As shown in FIG. 7A, when the slope 11 is lowered rearward, the installation distance L ₁ of the base end of the column structure 10 is avoided so that the protective net 40 avoids excessive tilting toward the slope valley side. To shorten.
If only the installation distance L ₁ is shortened, the overall dimensional balance is lost.
Therefore, by extending the adjustment tool 17 to increase the total length y ₁ of the second connecting member 13, it is possible to maintain a good overall dimensional balance.

As shown in FIG. 7B, when the slope 11 rises rearward, in order to avoid excessive tilting of the protective net 40 toward the slope mountain side, the installation distance L ₂ of the base end of the column structure 10 is set to Lengthen.
Dimensions balance of the whole Longer only installation distance L ₂ is lost.
Therefore, by using the adjuster 17 to shorten the overall length y ₂ of the second connecting member 13, it is possible to maintain a good overall dimensional balance.

In this countermeasure, the shape of the triangle formed by the three sides of the protective net 40, the first connecting member 12, and the modified derivative 30 does not change the length of each side.
As described above, the ideal dimensional balance is maintained by simply adjusting the total length y of the second connecting member 13 according to the slope of the slope 11 at the installation site, and the standing angle of the receiving surface 41 and the fence The height can be kept constant.

<2> Countermeasure 2
FIG. 8 shows a model diagram of the column structure 10 having an ideal dimension balance.
In this countermeasure, the total length of the axial force absorber 20 and the deformation derivative 30, the fence height H of the protective net 40, and the total length x of the first connecting member 12 are the same as in the previous countermeasure 1, The main body processing method presupposes that the installation distance L of the axial force absorber 20 and the deformation derivative 30 is not changed.

The axial force absorber 20 used in the present coping method is constituted by a bullet with a long overall length compared to the coping method 1, and an extra length portion 20a is formed at the free end of the axial force absorber 20, By rotating the nut 26, the hanging height of the upper side of the protective net 40 can be arbitrarily adjusted.
The extra length portion 20a refers to a section from the screwing position of the nut 26 to the tip of the axial force absorber 20, and the length of the extra length portion 20a changes by displacing the screwing position of the nut 26. .

As shown in FIG. 9A, when the slope 11 is lowered rearward, the second connecting member 13 is extended by operating the adjustment tool 17 in order to prevent the protective net 40 from tilting toward the slope valley. It is possible to keep the standing angle of the receiving surface 41 and the height of the fence constant by increasing the total length y ₁ and displacing the nut 26 on the axial force absorber 20 toward the tip side.

As shown in FIG. 9B, when the slope 11 is rearwardly raised, the adjustment tool 17 is shortened to avoid the tilt of the protective net 40 toward the slope mountain side. By shortening the total length y ₂ and displacing the nut 26 on the axial force absorber 20 toward the base end side, it is possible to keep the standing angle and the fence height of the receiving surface 41 constant.

Even in this countermeasure, the shape of the triangle formed by the three sides of the protective net 40, the first connecting member 12, and the deformation derivative 30 does not change.
In this countermeasure, the axial force is adjusted by an operation of adjusting the total length y of the second connecting member 13 according to the gradient of the slope 11 at the installation site and an operation of adjusting the position of the nut 26 on the axial force absorber 20. While maintaining the installation distance L between the absorber 20 and the deformable derivative 30 to be constant, an ideal dimensional balance can be maintained and the standing angle of the receiving surface 41 and the fence height can be kept constant.

The above-mentioned countermeasures 1 and 2 are used properly according to the situation at the site or used in combination.

[Energy absorption of shock absorbing fence]
Next, the energy absorption mechanism by the shock absorbing fence will be described with reference to FIG.

<1> Deformation deformation of protection net When energy acts on the receiving surface 41, the protection net 40 bends and deforms toward the inclined valley, and a part of the energy is attenuated by the deformation of the protection net 40.

<2> Non-compression deformation of deformation derivative A tension is generated in the first and second connecting members 12 and 13 as the axial force absorber 20 tries to rotate in the clockwise direction around the base end.
The tension acts on the first and second connecting members 12 and 13 as an axial force with respect to the deformation derivative 30 that tilts toward the inclined valley, but is supported by the deformation derivative 30 without compressive deformation due to its rigidity. .

<3> Tilt restraint of deformation derivative In addition, the free end of deformation derivative 30 is supported by second connection member 13 connected to slope 11 and first connection member 12 connected to the free end of axial force absorber 20. Thus, the tilt angle of the deformation derivative 30 hardly changes, and the tilt of the deformation derivative 30 is restricted.
Therefore, energy acting on the deformation derivative 30 can be guided to the axial force absorber 20.

<4> Rotation restraint of axial force absorber At the same time, the axial force absorber 20 tries to rotate in the clockwise direction around the base end, and tension is generated in the first and second connecting members 12 and 13.
The tension acting on the first and second connecting members 12 and 13 is finally supported by the anchor 25, and the clockwise rotation of the axial force absorber 20 is restricted.

<5> Compression deformation of axial force absorber

A resultant force of the tension generated by the protection net 40 and the tension generated by the first and second connecting members 12 and 13 acts on the axial force absorber 20 as an axial force.
When the axial force generated in the axial force absorber 20 exceeds the deformation strength, the axial force absorber 20 is compressed and deformed.
Energy is efficiently absorbed by the compressive deformation of the axial force absorber 20.
In particular, since the energy absorbing member is only the axial force absorber 20, the energy absorbing performance can be easily calculated, and stable energy absorbing performance can be exhibited.

  Furthermore, even if a large amount of energy acts, the axial force absorber 20 acts as a cushion to avoid breakage of the first and second connecting members 12 and 13 and buckling failure of the deformation derivative 30. Function is not lost suddenly.

Further, even if bending or twisting of the inclined surface 11 acts on the axial force absorber 20, the free ends of the elastic rods 21 and 21 constituting the axial force absorber 20 are bent and deformed or twisted. Bending force and torsional force do not act on the base ends of the bullets 21 and 21.
Therefore, even if bending or twisting acts on the axial force absorber 20, it does not break.

As described above, the shock absorbing fence according to the present invention transmits the energy received by the protective net 40 as an axial force only to the axial force absorber 20 and transmits it as a tension to the connecting members 12 and 13 as the holding members. In addition, the axial force acting on the axial force absorber 20 can be efficiently deformed by compressing and deforming the axial force absorber 20 while maintaining uprightness.
Furthermore, since the column structure 10 has a buffer function, the tension load of the connecting members 12 and 13 and the load load of the anchors 23 and 34 can be reduced.

<6> After the disappearance of energy After the energy generation factor is removed from the protective net 40 (receiving surface 41), the axial force absorber 20 constituting the column structure 10 is restored to its original standby position by its own elastic restoring force. Return to.
As the support structure 10 is restored, the protective net 40 is also lifted to the original position.
Therefore, the state before the action of energy can be maintained and the function of the shock absorbing fence can be continuously maintained.
For example, if the energy generation factor is snow pressure, the axial force absorber 20 will naturally return to its original position when the snow melts, so that the function of the shock absorbing fence is always exerted without taking any special measures. I can keep it.

Even if the axial force absorber 20 and the deformation derivative 30 constituting the support structure 10 are deformed or broken, only the damaged material can be replaced easily and in a short time.

In the first embodiment, the configuration in which the lower side of the protective net 40 is fixed to the base end of the modified derivative 30 has been described.
By hanging the protective net 40 on the free end of the axial force absorber 20, the weight balance is maintained and the stable posture of the support structure 10 can be maintained, so the lower side of the protective net 40 can be fixed to the mountain slope. is there.
By fixing the lower side of the protective net 40 to the slope on the mountain side, the length of the protective net 40 in the inclined direction of the slope can be increased compared to the first embodiment, and the amount of bending deformation of the protective net 40 can be increased. There is an advantage of high performance.

In the first and second embodiments, the mode in which the length adjuster 17 is interposed in the second connecting member 13 has been described. However, the length adjuster 17 may be interposed in the first connecting member 12.
Alternatively, as shown in FIG. 11, the length adjuster 17 is interposed between the first connecting member 12 and the second connecting member 13, or the length adjuster 17 is interposed between all the connecting members 12 to 14. Or you may.
By increasing the number of intervening length adjusters 17, the installation angle of the axial force absorber 20 and the deformation derivative 30 can be individually adjusted according to the undulation of the slope 11.
Further, by combining with the second embodiment, there is an advantage that it is easy to perform the installation work in which the standing angle of the receiving surface 41 and the height of the fence are kept constant even on the site where the slope 11 has various undulations.

DESCRIPTION OF SYMBOLS 10 Support | pillar structure 12 1st connection material 13 2nd connection material 14 3rd connection material 15 Upper rope 16 Lower rope 17 Length adjustment tool 20 Axial force absorber 21 Elastic rod 22 Support shaft 30 Deformation derivative 31 Support Shaft 40 Protective net 41 Reception surface

Claims (9)

An axial force absorber that is erected in a tiltable manner with a proximal end fixed, a deformation derivative that is disposed so as to be tilted with a proximal end fixed and the axial force absorber, and the axial force A strut structure for an impact absorbing fence, comprising a connecting member that connects between the absorber and each free end of the deformation derivative, and a connecting member that connects the free end of each of the axial force absorber and the deformation derivative and the slope. And
The axial force absorber is composed of a plurality of bullets restrained at both ends,
The deformation derivative is made of a rigid material,
An axial force acting on the deformation derivative is configured to be guided to the axial force absorber through the connecting material,
Shock absorber fence support structure.   The strut structure for an impact absorbing fence according to claim 1, wherein a length adjuster is interposed in a part of the connecting material so that the length of the connecting material can be adjusted.   In Claim 1 or Claim 2, it connected between the free ends of a plurality of bullets with a binding board, and it was constituted so that the installation position of the binding board could be displaced along the bullets. Shock absorber fence support structure.   4. The strut structure for an impact-absorbing fence according to claim 3, wherein the installation position of the bundling plate is configured to be displaceable along the elastic rod by a nut screwed into the elastic rod.   The strut structure according to any one of claims 1 to 4, further comprising an anchor for fixing the base ends of the axial force absorber and the deformation derivative. An impact absorbing fence comprising a plurality of support structures standing at intervals and a protective net stretched between the support structures,
Using the support structure according to any one of claims 1 to 5,
While fixing the base end of the axial force absorber to the valley side slope, and fixing the base end of the deformation derivative arranged to intersect the axial force absorber to the mountain side slope, the column structure is erected,
It is characterized in that the upper side of the protective net is attached to the free end of the axial force absorber that constitutes each of the adjacent strut structures and is arranged on the mountain side slope,
Shock absorbing fence.   7. The axial force according to claim 6, wherein energy acting on the protective net is dispersed in the crossed axial force absorber and the deformation derivative so that the axial force generated in the deformation derivative can be transmitted to the axial force absorber. An impact-absorbing fence, characterized in that the absorber is connected to each free end of the deformation derivative, and the free end of each of the axial force absorber and the deformation derivative is connected to the inclined surface by a connecting material.   The shock absorbing fence according to claim 6 or 7, wherein a lower side of the protective net is attached to a base end of a modified derivative constituting each support structure.   The shock absorbing fence according to claim 6 or 7, wherein a lower side of the protective net is fixed to a mountain slope.

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