JP5164791B2 - Shock absorbing fence - Google Patents

Description

  The present invention relates to an impact absorbing fence that absorbs an impact absorbing structure such as rock fall, landslide, and avalanche.

An impact absorbing fence made up of columns that are erected at a predetermined interval and a protective net that is installed between the columns is widely known from Patent Document 1 and the like.
The protective net is constructed by combining a wire rope and a wire mesh, and receives a shock with the tensile strength of the metal material, and finally transmits the shock to the support to support it.
As this kind of support, a steel structure or a composite structure in which a steel pipe is filled with concrete is the mainstream, and the lower part of the support is directly buried in the ground or standing on the foundation concrete. In addition, a support rope made of wire rope is connected between the upper part of the column and the slope to increase the independence of the column.

  Further, Patent Document 2 discloses that a support column is divided into two parts in the vertical direction, and the support column upper part is connected after the support column lower part is embedded in advance.

Further, Patent Document 3 discloses a shock absorbing fence in which a protective net is formed of a synthetic resin net, and a hinge is provided at a lower portion of the support column so that the support column can be tilted to reduce its weight. .
JP 2002-115213 A JP 2008-88713 A JP 2004-76275 A

The conventional shock absorbing fence has the following problems.
(1) Many shock-absorbing fences are installed in inconvenient places such as mountainous areas and mountainous areas.
In such a site, there is a problem that it takes a lot of time and cost to carry in a long support column including an embedding length and to lift and stand a long support column at the site.
In particular, the pillars of Patent Document 1 that are manufactured in the factory in advance by filling the steel pipe with concrete are heavy and the depth of the pillars is deep, so that heavy machinery is used for carrying in and building the pillars. Required.
(2) Since the support described in Patent Document 2 has a connection structure in which the upper part of the lower part of the support and the lower part of the upper part of the support are only fitted through an adhesive, the connecting part has a weak weak point. Prone.
(3) In patent document 3, the support | pillar is erected by landing the board | substrate provided in the lower part of the support | pillar, and fixing a some lock bolt to this board | substrate.
Although the plurality of lock bolts function to prevent the lateral displacement of the column, they do not function at all to increase the strength of the column.
(4) In any conventional shock absorbing fence, a support rope is connected and supported for the self-supporting of the column.
At the time of receiving the impact, the impact transmitted to the support column concentrates on the connection portion between the upper portion of the support column and the upper end of the stay rope and the connection portion between the anchor on the slope side and the lower end of the stay rope.
Therefore, when a big impact acts, there exists a possibility that the connection part of the edge part of a reserve rope may fracture | rupture or an anchor may be damaged.
If the supporting function of the supporting rope by the holding rope is lost before the protective net or the supporting column exhibits the original shock absorbing function, the original performance of the shock absorbing fence cannot be exhibited.
(5) In order to avoid breakage of the stay rope, it is known that a friction resistance type shock-absorbing metal fitting is interposed at the connection portion of the stay rope.
Generally, the shock-absorbing bracket is composed of a plurality of clamping bodies that clamp the rope material and a plurality of bolts and other fastening means that clamp the rope material via these clamping plates. There is a problem in that stable buffer performance cannot be exhibited due to power variation.

The present invention has been made in view of the above points, and an object thereof is to provide at least one of the following shock absorbing fences.
(1) The column can be installed without using heavy machinery, and it has excellent workability on site.
(2) With a simple structure, the support strength of the support is increased and the independence of the support is improved.
(3) Material costs and construction costs can be reduced.
(4) To prevent breakage of the holding rope and breakage of the anchor without using a buffer fitting.

Shock according to the first aspect of the present invention, which includes a post erected at intervals, and synthetic fibers made of copy material connected to the post, a plurality of synthetic fibers made of protective nets laterally placed between the mounting posts of the present application In the absorption fence, the column is supported by a hollow column body supported by a pivot mechanism so as to allow tilting in all directions, and an end cap that is installed at an end of the column body and attaches the retaining material and the protective net. If, by fixing the lower into the ground, comprising a tension core material inserted through the end cap provided at the upper portion of the column body and the support body, a fixing member which is screwed to the end of the previous SL tension core Tighten to obtain a reaction force on the tensioned core material and apply an axial compressive force to the column main body, and a buffer rope material made of a synthetic fiber larger than the breaking elongation of the material is attached to a part of the material. And when the tensile force acts on the retaining material and the buffer rope material, the buffer rope There wherein the extended deformation, provides a shock absorbing fence.
The second invention of the present application provides the shock absorbing fence according to the first invention, wherein the buffer rope material has a breaking elongation of 30 to 300% .
According to a third invention of the present application, there is provided an impact absorbing fence according to the first or second invention, wherein a foundation anchor is provided in accordance with a standing position of the support column, and a tension core is connected to the foundation anchor. provide.
According to a fourth invention of the present application, in any one of the first to third inventions described above, the pivot mechanism is a combination of a hemispherical joint concave portion and a joint convex portion that is pivotably supported by the joint concave portion. An impact absorbing fence is provided.
The fifth invention of the present application, in any one of the invention in the first to fourth mentioned above, disposed between the posts, and the first shock absorber reticulated guard net is made of synthetic fiber having stretchability, between posts impact by the polymerized with the first shock absorber disposed, having stretchability constituted by a second shock absorber made of synthetic fibers, stretching deformation of the first shock absorber and a second shock absorber A shock absorbing fence is provided, which is characterized by absorbing water.

The present invention can obtain the following effects.
(1) Since each material which comprises a support | pillar is lightweight, it can carry in to an on-site and an assembly only by an operator's human power, without using heavy machinery.
Therefore, the shock absorbing fence can be constructed by a simple method even in mountainous areas and steep slopes where it has conventionally been difficult to install the shock absorbing fence.
(2) There is no need to perform any special additional processing on the column body, and a commercially available steel pipe can be used as it is.
Therefore, not only can the cost of the support column be reduced, but also the assembly time and cost of the support column can be reduced.
(3) It can be erected in a state where a compressive force is applied to the strut via the tension core.
Compared to the conventional standing technology in which the lower part of the support is buried deep in the ground, the ability to absorb the impact by the support is enhanced as the support of the support is significantly improved.
(4) Since the lower part of the column main body is supported so as to be tiltable in all directions via the pivot mechanism, the supporting part of the column is less likely to be destroyed as compared with the conventional hinge mechanism having a limitation in the tilting direction.
(5) The buffer rope material is interposed when an excessive impact load is applied while maintaining the basic function (supporting function of tilting of the column) by interposing the buffer rope material in a part of the material. By stretching, it is possible to safely and reliably avoid the breakage of the retentive material and the breakage of the anchor.
Therefore, the evaluation with respect to the safety as an impact absorption fence becomes higher.
(6) By forming the protective net with the first shock absorber and the second shock absorber made of synthetic fiber, the protective net can be significantly reduced in weight compared to the conventional metal net, and the conventional metal It is possible to ensure the same strength as the net made by the manufacturer.
(7) Compared to conventional metal nets, the amount of extension of the protective net made of synthetic fiber is remarkably increased, so that the shock absorbing performance of the protective net alone is greatly improved.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

(1) Outline of the shock absorbing fence The shock absorbing fence is a fence installed on a hillside or slope where rockfalls, landslides and avalanches are expected to occur. The support column 10, the protective net 20 laid across the support column 10, and the retaining material 40 that supports the support column 10 by obtaining a reaction force from the natural ground.

  The retentive material 40 is a tensile material made of synthetic fiber, and is disposed between the upper portion of each column 10 and the anchor 35 provided on the mountain side of the slope and, if necessary, the valley side.

Although the structure of the support | pillar 10 and the detail of the standing structure are mentioned later, in this invention, the support | pillar 10 is erected using the foundation anchor 30, without burying the lower part of the support | pillar 10 in the ground.
The following describes the main materials that make up the shock absorbing fence.

(2) Protective Net In this example, the protective net 20 is disposed between the net-like first shock absorber 21 made of a stretchable synthetic fiber and the support 10 and a second impact made of a stretchable synthetic fiber. The case where it comprises and the absorber 22 and comprised so that an impact may be absorbed by the expansion deformation of the 1st impact absorber 21 and the 2nd impact absorber 22 is demonstrated.

The first shock absorber 21 is a net-like body having an overall shape of a rectangle, and is a net-like object for capturing falling objects such as falling rocks. The knitting structure is not particularly limited, and is a knot type or a no-knot type. Either may be sufficient.
There is no particular limitation on the shape, mesh size (mesh), and thickness of the first shock absorber 21, and it may be appropriately determined according to the scale of rock fall expected at the installation location.

  The second shock absorber 22 is a rope member that is stretched in parallel between the adjacent struts 10 in the lateral direction, and is made of a synthetic fiber having elasticity like the first shock absorber 21. ing.

  Examples of synthetic fibers constituting the first shock absorber 21, the second shock absorber 22 and the retaining material 40 include, for example, polyolefin fibers such as polyethylene and polypropylene, ultrahigh molecular weight polyethylene fibers, low pressure polyethylene fibers, polyarylate fibers, Polyester fibers such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyamide fibers such as polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, aramid fibers such as polyparaterephthalamide and polymetaterephthalamide, polybenzo One type or two or more types of oxazole fiber, carbon fiber, poly-p-phenylenebenzobisoxazole fiber, polyoxyketone fiber, acrylic fiber, rayon fiber, glass fiber, etc. Combined and can be used.

The breaking strength of the buffer net 20 is preferably 5 to 40 kN, and more preferably 5 to 10 kN.
When the breaking strength of the buffer net 20 is less than 5 kN, compared to the case where the breaking strength is within the above range, there is a problem that even if it can absorb the impact, it cannot withstand the impact and easily breaks.
In addition, when the strength exceeds 40 kN, the diameter of the buffer net 20 increases as compared with the case where the strength is in the above range, and the workability at the time of construction of the protective fence is deteriorated. is there.

(3) Foundation anchor and tension core material The foundation anchor 30 is an anchor provided in accordance with the standing position of the support column 10, and in this example, a case where a simple anchor rod is employed will be described.
The protruding portion of the foundation anchor 30 exposed on the ground surface is threaded so that it can be connected to the tension core member 32 for extension via a coupler 31 which is a joint tool shown in FIG.

For the foundation anchor 30 and the tension core 32, a known PC steel bar, a reinforcing bar or the like can be used.
The extension anchor core 32 is connected to the foundation anchor 30 by tensioning these members 30 and 32 to fix the column 10, thereby improving the independence of the column 10 and reducing the tilting resistance of the column 10. This is to increase it.

(4) Strut As shown in FIGS. 1 and 2, the strut 10 includes a hollow strut body 11, an end cap 12 provided at the end of the strut body 11, a loading plate 13 provided at the bottom of the strut body 11, A tray plate 14 interposed between the lower portion of the column main body 11 and the loading plate 13 is provided.

[Staff body]
The column body 11 is a hollow tube such as a steel tube, and is set to an appropriate length according to the height of the shock absorbing fence.
As will be described below, the use of the end cap 12 eliminates the need to attach a structural element for rope connection to the column main body 11, thereby simplifying the structure of the column main body 11.
Along with the simplification of the column main body 11, it is possible to decorate the outer surface of the column main body 11 by coating or coloring various decorative materials. For example, if a decoration made of pseudo-wood is applied to the outer surface of the column main body 11, the shock absorbing fence can be harmonized with the surrounding environment.

[End cap]
As shown in FIG. 2, the end cap 12 is a short column having an outer diameter different in diameter with a through hole 12 a formed in the center, and functions as a pressure bearing plate when tensioning the column 10 at least. It also has a function as a mounting member.
The small diameter portion 12 b of the end cap 12 is set to a diameter that allows the column main body 11 to be inserted, and the large diameter portion 12 c is set to a diameter that the column main body 11 cannot be inserted.
A plurality of ring-shaped hooks 12d are provided on the outer peripheral surface of the large-diameter portion 12c.
The hook 12d functions as a mounting member for the defense net 20 and the retaining member 40. In this example, the case where two hooks 12d are provided in a straight line with respect to the large diameter portion 12c is shown in FIG. In some cases, three hooks 12d or four hooks 12d are provided.

[Loading plate and plate]
The loading plate 13 is a plate for forming a through hole 13a in the center thereof and supporting the column main body 11 in a tiltable manner.
In the center of the loading plate 13 in which the through-hole 13a is formed, a joint recess 13b that is recessed in a hemispherical shape is formed.
The upper surface of the dish plate 14 having a through hole 14a formed in the center is formed as a flat surface, and the lower surface of the dish plate 14 is formed with a joint convex portion 14b that can be pivotably supported corresponding to the joint concave portion 13b. It is.
The joint convex part 14b of the tray plate 14 is accommodated in the joint concave part 13b of the loading plate 13, and the pivot mechanism which accepts the inclination of the support | pillar 10 in all directions is comprised.

In addition, the pivot mechanism may be formed by combining the forming members of the concavity and convexity portion of the loading plate 13 and the plate 14 in the reverse combination, or the plate 14 is omitted and is joined to the end surface of the large diameter portion of the end cap 12. Either one of the uneven portions may be formed.
The reason why the joint concave portion 13b and the joint convex portion 14b are formed in a hemispherical shape corresponding to each other is to allow the column 10 to tilt in all directions.

(5) Retaining Material and Buffer Rope Material Retaining material 40 stretched between the end cap 12 at the top of the support column 10 and the anchor 35 fixed on the ground is a tensile material made of synthetic fiber.

  In this example, a buffer rope material 41 made of synthetic fiber is interposed between the lower portion of the retaining member 40 and the anchor 35 or between the upper portion of the retaining member 40 and the upper end cap 12.

The breaking elongation of the buffer rope material 41 is larger than the breaking elongation of the recording material 40.
The breaking elongation of the buffer rope material 41 is 30 to 300%. More preferably, it is more preferably 100 to 300%, and particularly preferably 100 to 200%.
The breaking elongation of the backing material 40 is 10 to 100%.

Here, the elongation at break refers to the length of the sample at the time of rupture A when the sample is broken by applying a load to the sample, and the initial length of the sample before the load is applied. When B, it is a value (%) represented by (B−A) × 100 / A.
Specifically, it is a value measured in accordance with 6.2 [k1] of “Temporary Industrial Association“ Safety Standards and Explanation Regarding Structure of Safety Net ””.

[Action]
Next, the construction method of the shock absorbing fence will be described.

(1) Foundation anchor construction FIG. 3 shows an assembly process of the column 10.
As shown to (A) of the figure, the foundation anchors 30, such as an anchor rod, are provided in the standing position of the support | pillar 10. As shown in FIG.
The upper part of the foundation anchor 30 is projected from the ground surface.
Moreover, although not shown in figure, the anchor 35 for fixing the retainer 40 is installed (FIG. 1).

(2) Assembly of support column As shown in FIG. 3 (B), the loading plate 13 is set to penetrate the foundation anchor 30 protruding to the ground surface. Further, the plate 14 and the large-diameter portion 12 c of the end cap 12 are placed on the loading plate 13 facing downward while penetrating the foundation anchor 30.
At this time, the hemispherical joining concave part 13b and the joining convex part 15b respectively formed in the opposing surface of the loading plate 13 and the plate 14 are fitted.
The upper part of the foundation anchor 30 is preset to a length protruding from the upper surface of the end cap 12.

  Next, as shown in FIG. 3C, the lower part of the tension core member 32 is connected to the exposed end of the foundation anchor 30 via a coupler 31.

  Subsequently, as shown in FIG. 3D, the column main body 11 is covered from above the tension core 32, and the lower opening of the column main body 11 is covered with the small diameter portion 12 b of the end cap 12.

As shown in FIG. 1, when the column main body 11 is externally mounted on the foundation anchor 30 and the tension core member 32 connected to each other, a separate end cap 12 is mounted on the upper portion of the column main body 11.
The upper end cap 12 is fitted into the upper end of the column body 11 with the small diameter portion 12b facing downward.
The upper end of the tension core 32 protrudes upward through the upper end cap 12.

  The fixing tool 34 such as a nut is fastened to the tension core member 32 protruding upward from the end cap 12 set on the upper portion of the column body 11 to complete the assembly of the column 10.

  By tightening the fixing tool 34 and introducing prestress to the basic anchor 30 and the tension core 32, a compressive force is applied to the column main body 11 in the axial direction to give the column 10 high independence.

(3) Installation of Retaining Material As shown in FIG. 1, a buffering rope material 41 is interposed between the upper portion of the support column 10 and the anchor 35 and connected with a reserving material 40.
In this example, the upper end of the support member 40 is connected to the upper portion of the support column 10, and the buffer rope material 41 connected to the lower end of the support member 40 is connected to the anchor 35 side. It may be connected to the upper side.

  In this example, when the upper end of the support member 40 is connected to the upper portion of the support column 10, the connection plate 36 mounted on the upper end cap 12 of the support column main body 11 is shown. You may connect with a hook.

  A buffer rope material 41 is interposed between the lower end of the retentive material 40 and the anchor 35.

(4) Attaching the protective net A protective net 20 made of synthetic fiber is attached between the columns 10 erected in the above work process.
Since the protective net 20 is significantly lighter than that made of metal, the workability of the protective net 20 can be improved, and the construction cost can be reduced and the construction period can be shortened.

[Shock absorption mechanism]

(1) Shock absorption by the protective net When an impact is applied to the protective net 20, the shock is distributed and transmitted to the first shock absorber 21 and the second shock absorber 22 constituting the protective net 20, and the first shock absorption. The impact is absorbed by the extension and deformation of the body 21 and the second shock absorber 22.
In particular, since the second shock absorber 22 reinforces the first shock absorber 21, the first shock absorber 21 is hardly damaged, and the shock absorption performance of the first shock absorber 21 can be guaranteed.
Compared to the conventional metal net, the protective net can be significantly reduced in weight, and the strength equal to or higher than that of the conventional metal net can be secured.

(2) Impact absorption by the support The impact due to the action on the protective net 20 is transmitted to the support 10.
The strut 10 is prestressed in the foundation anchor 30 and the tension core 32 to apply a high compressive force to the strut body 11 to enhance the strength.
Therefore, the impact is absorbed by the strength of the column 10.

In addition, when an impact greater than the self-supporting strength of the column 10 is applied, the column 10 can be tilted by the fitting structure of the bonding concave portion 13b and the bonding convex portion 15b formed between the lower portion of the column main body 11 and the loading plate 13. To do.
Since a high compressive force is continuously applied to the column main body 11 while the column 10 is tilted, the shock is absorbed as the column 10 is tilted.

In the case of the conventional hinge structure, there is a problem that since the tilt direction is limited, the load is concentrated on the hinge portion and the hinge is easily damaged.
On the other hand, in the present invention, since the lower part of the support column 10 can be pivoted in all directions, the tilt direction of the support column 10 is not limited, and can be tilted in all directions.
Therefore, it can avoid that a load concentrates on the pivotal support part of the support | pillar 10. FIG.

(3) Shock Absorption Mechanism by Retaining Rope In parallel with absorbing the shock by tilting the support column 10 described above, the impact is also absorbed by extension deformation of the buffer rope member 41 on which the upper portion of the support column 10 and the anchor 35 are installed. .
The impact acting on the support column 10 acts as a tensile force on the holding member 40 and the buffer rope member 41. When this tensile force exceeds the tensile strength of the holding member 40 and the buffer rope member 41, only the buffer rope member 41 is applied. Elongates and deforms.
Therefore, it is possible to prevent the breakage of the retaining material 40 and the anchor 35 from being broken at once immediately after the impact is applied.

Model diagram of shock absorbing fence according to the present invention Exploded view of prop Explanatory drawing of assembly process of support Model diagram of shock absorbing fence according to the present invention Bottom view of end cap with different number of hooks

Explanation of symbols

10... Column 11... Column body 12... End cap 12 a... Through hole 12 b... Small diameter portion 12 c. · Hook 13 · · · Loading plate 14 · · Plate 20 · · · Protection net 21 · · · First shock absorber 22 · · · Second shock absorber 30 · · · ·································································· 31

Claims (5)

In the shock absorption fence provided with the support pillars erected at intervals, the synthetic fiber retaining material connected to the support pillars, and the protective net made of synthetic fiber laid horizontally between the plurality of support pillars,
The column is a hollow column body supported via a pivot mechanism so as to allow tilting in all directions;
An end cap that is installed at the end of the column main body and attaches the retaining material and the protective net ;
The lower part is fixed in the ground, and includes a strut body and a tension core inserted through an end cap provided on the top of the strut body.
The compressive force in the axial direction is given to the strut body to give a reaction force to the tension core by tightening the fixing member which is screwed to the end of the previous SL tension core,
A buffer rope material made of synthetic fiber larger than the breaking elongation of the retaining material is interposed in a part of the retaining material,
When a tensile force acts on the holding material and the buffer rope material, the buffer rope material is elongated and deformed ,
Shock absorbing fence. The shock absorbing fence according to claim 1, wherein the breaking elongation of the buffer rope member is 30 to 300% .   The shock absorbing fence according to claim 1 or 2, wherein a foundation anchor is provided in accordance with a standing position of the support column, and a tension core is connected to the foundation anchor.   The pivot mechanism according to any one of claims 1 to 3, wherein the pivot mechanism is a combination of a hemispherical joint concave portion and a joint convex portion that is pivotably supported by the joint concave portion. Shock absorbing fence. In any one of claims 1 to 4, disposed between the posts, and the first shock absorber reticulated guard net is made of synthetic fiber having stretchability, the first shock absorber between the mounting posts And a second shock absorber made of a synthetic fiber having elasticity, and arranged in a polymerized manner .

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