JPH11315512A - Shock absorption fence and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a design with low strength without lowering shock damping action and, at the same time, to facilitate replacement of a strut. SOLUTION: A buffer 6 holding a stay rope 7 to allow it to slide is provided to a strut 3. The stay rope 7 is connected between the buffer 6 and an anchor 8. The lower part of the strut 3 is pivoted on a footing concrete 1 with a bearing 4 in a tiltable manner. Shock is absorbed by frictional resistance between the buffer 6 and stay rope 7 while tilting the strut with the pivot section 4 as the center while receiving part of shock acting on the strut 3 as compressive force toward the pivot section 4 of the strut 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorbing technology for attenuating kinetic energy such as falling rocks and avalanches.

[0002]

2. Description of the Related Art As a shock absorbing fence for rock fall prevention, a wire rope or a net is stretched between supports erected at equal intervals on a foundation concrete, and a stay rope is provided between an upper part of each support and an anchor on a mountain side. Connected things have been known for a long time. As shown in FIG. 8, a shock absorbing member b is interposed in the middle of the stay rope a so that the deformation of the support column c and the damping effect due to the sliding resistance between the stay rope a and the shock absorber b are achieved. There has been proposed a shock absorbing fence for preventing rock fall, which attenuates energy of a large rock fall.

[0003]

The above-described conventional shock absorbing technology has the following problems.

<1> The overturning moment due to the impact acting on the impact absorbing fence is finally supported by the bending strength of the column c. This overturning moment is constant without change even while the column c is deformed. Therefore, in order to counter this overturning moment, it is necessary to increase the size of the column c and to design it with high strength.

<2> Since the overturning moment acting on the pillar c also acts on the foundation concrete d supporting the pillar c, it is necessary to design not only the pillar c but also the foundation concrete d large.

<3> Due to the reasons <1> and <2> described above, the conventional shock absorbing fence has a high shock absorbing cost and has room for improvement.

<4> When replacing the pillar c deformed due to falling rocks, the foundation concrete d must be rebuilt after being destroyed, and replacement of the pillar c requires much time and cost.

<5> The stay rope a is connected to an anchor e fixed on the mountain side of the column c. Therefore, it is necessary to secure a land from the position of the support column c to the anchoring position of the anchor e, and the use cost of the land increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a shock absorbing technique which enables a low-strength design without reducing the shock damping action. Is to do.

It is a further object of the present invention to provide a shock absorbing technique which can easily replace a column.

[0011]

The invention according to claim 1 is
At a shock absorbing fence where a wire rope or a net is stretched between pillars erected at predetermined intervals on the foundation concrete and a retaining rope is connected between the upper part of the pillar and the anchor, at the upper part of the pillar or the retaining rope, or in the middle of the retaining rope A shock absorber is provided between the rope and the anchor so as to allow the stay rope to slide, and the lower part of the column is pivotally supported via a hinge so that the column can be tilted without transmitting a bending moment to the column. It is characterized by the following. The invention according to claim 2 is the shock absorbing fence according to claim 1, wherein an anchor is provided on the same basic concrete as the shock absorbing fence, and an end of a stay rope connected to a support is connected to the anchor. Features. According to a third aspect of the present invention, in the shock absorbing fence according to the first aspect, a plurality of shock absorbers for holding the stay rope so as to allow sliding thereof are provided in series on the support, and the stay rope is attached to each shock absorber. It is characterized by being held. Claim 4
According to the invention according to claim 3, in the shock absorbing fence according to claim 3,
A buffer is provided on the foundation concrete so as to allow the stay rope to slide, and the stay rope is gripped between the plurality of cushions provided on the columns and the buffer on the foundation concrete. According to a fifth aspect of the present invention, in the shock absorbing fence according to any one of the first to fourth aspects, the shock-absorbing device has a corrugated groove for accommodating the retaining rope, and the retaining rope is provided along the corrugated groove. It is characterized by being held. The invention according to claim 6 is that a wire rope or a net is stretched between pillars erected at predetermined intervals on the foundation concrete, and a stay rope is connected between the upper part of the pillar and the anchor, and the upper part of the pillar or the stay is provided. An impact that grips the stay rope in an acceptable manner in the middle of the rope or between the stay rope and the anchor, and absorbs the impact acting on the strut due to frictional resistance between the shock absorber and the stay rope. In the absorbing method, the impact absorbing fence according to any one of claims 1 to 5 is used, and a part of the impact force acting on the column is received as a compressive force toward the pivotal portion of the column. The impact is absorbed by frictional resistance between the shock absorber and the stay rope while tilting the column around the pivot without transmitting the bending moment.

[0012]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

<A> Configuration of Shock Absorbing Fence FIG. 1 shows a model diagram of a shock absorbing fence according to the present invention. A bracket 2 for mounting a pillar is mounted on a top surface of a foundation concrete 1 at a predetermined interval, and a lower end of a pillar 3 made of a rigid member such as an H-section steel or a steel pipe is pivotally supported by a shaft 4. A wire rope 5, a net, and the like are stretched between the columns 3 as in the related art, forming a shock absorbing fence.

In the present invention, the lower part of the column 3 has a hinge structure,
I tried to be proactive. This is because the column 3 is tilted along the direction in which the impact force such as a falling rock acts, so that the bending moment acting on the column 3 is greatly reduced, and the exchangeability of the column 3 is improved.

That is, while the conventional concept is to absorb the impact by bending the column, the present invention does not actively utilize the bending deformation of the column 3 for absorbing the impact. The shock is absorbed by the sliding resistance between the shock-absorbing tool 6 provided in the above and the stay rope 7 made of wire. Therefore, in the present invention, it is only necessary to provide the buckling strength enough to resist the compressive force caused by the impact in the design of the column 3.

If the support 3 is simply pivoted to the bracket 2, the support 3 may fall over to the mountain side. As a countermeasure, for example, a stopper is provided at the lower part of the column 3 to prevent the column 3 from falling to the mountain side, or a rope material for preventing the column 3 from falling is connected between the column 3 and the valley side.
Can be dealt with by erecting it slightly inclining to the valley side from the vertical line.

<A> Fixing position of stay rope Based on the conventional idea of absorbing impact due to bending deformation of the support, it has been considered that the farther the fixing position on the mountain side of the stay rope is far from the support, the more effective. . Conventionally, the bending moment was almost constant even during the deformation of the column.

In the present invention, since the lower portion of the column 3 is erected with a hinge structure as described above, the fixing position of the stay rope 7 on the mountain side is provided on the same basic concrete 1 as the shock absorbing fence (column). It becomes possible. That is, the anchor 8 is provided at a position farther from the support 3 of the foundation concrete 1 on the mountain side, and one of the stay ropes 7 is fixed to the anchor 8.

The fixing position of the stay rope 7 on the mountain side is brought closer to the column 3 side in order to omit the anchor fixed on the mountain side remote from the foundation concrete 1 and to change the overturning moment acting on the column 3. It is. That is,
The tension T of the stay rope 7 is constant both in the initial state of the overturning moment as shown by the solid line in FIG. 4 and in the inclined state as shown by the dashed line.
₁ and R ₂ gradually decrease. Therefore, the moment M ₁ in the initial falling state is expressed as M ₁ = T · R ₁ , and the moment M ₂ at the time of inclination is expressed as M ₁ = T · R ₂ . As described above, since the arms R ₁ and R ₂ from the pivot portion gradually decrease with the tilting, the moment M ₂ when tilting is smaller than the moment M _{1 in the} initial tilting state, and the tilting of the column 3 proceeds. Therefore, the moment M ₂ is reduced. Therefore, the overturning moment with respect to the foundation concrete 1 also decreases with the inclination of the column 3.

<C> Shock absorber An example of the shock absorber 6 shown in FIGS.
The shock-absorbing device 6 is composed of two holding members 9, 9 with corrugated grooves 10 having arcuate cross sections formed on the opposing surfaces thereof. The retaining rope 7 is gripped by the bolt 11 and the nut 12, and the gripping force of the retaining rope 7 can be adjusted by the fastening force of the bolt 11 and the nut 12. Corrugated groove 1
The end of 0 is preferably rounded in a trumpet shape in order to avoid damage to the stay rope 7, and the means for attaching the shock absorber 6 to the column 3 is preferably bolted with a U bolt or the like. is there.

The cushioning member 6 is not limited to the holding members 9 and 9 vertically divided into two, but the plate is divided into two in the horizontal direction, and the corrugated groove is horizontally formed on the opposing surface of each plate. It may be formed in the direction. The point is that any structure can be used as long as the stay rope 7 can be forcibly bent and gripped. This is because, when the stay rope 7 is forcibly bent as compared with the case where the stay rope 7 arranged linearly is gripped, an energy attenuating action due to the forced bending and return of the stay rope 7 is added.

[0022]

(A) Impact Absorbing Action In FIG. 1, the impact absorbing action when a falling rock falling from the mountain on the right side of the figure collides with the fence and the impact energy is transmitted to the column 3 will be described.

The impact energy applied to the column 3 is
Acts as a falling moment, but for the following reasons:
No large bending force is generated on the column 3. That is, the support 3
Is rotatably supported by a support shaft 4. Therefore, a part of the impact force acting on the support 3 is
Acts as a compressive force toward the (pivot). When the overturning moment acting on the shock absorber 6 and the stay rope 7 at the upper part of the support 3 exceeds the gripping force (friction resistance) of the stay rope 7 in the shock absorber 6, the stay rope 7 starts sliding on the shock absorber 6. The impact energy is efficiently attenuated by the sliding resistance while the column 3 tilts toward the valley side.

While the support 3 is tilting, the support rope 7 is attached to the support 3.
Thus, only a compressive force is generated by being urged in the direction of the support shaft 4, and the bending force acting on the support column 3 can be reduced as compared with the conventional structure in which the support column is embedded in the foundation concrete.

As described above, according to the present invention, the damping action of the impact energy is obtained not by the bending deformation of the support 3 but by the damping action of only the shock absorber 6. Can be easily and accurately obtained by calculation.

Further, since the column 3 does not need to be subjected to a large bending force, it can be designed to have a lower rigidity than the conventional one.

Considering the change of the overturning moment, in the conventional structure in which the strut is buried in the foundation concrete, a large overturning moment is generated when an impact force acts on the strut. Almost unchanged during deformation.

On the other hand, in the present invention, the overturning moment acting on the support 3 decreases as the support 3 tilts,
The overturning moment of the foundation concrete 1 supporting the column 3 is reduced. This is as described above. Therefore, the burden on the foundation concrete 1 can be reduced as compared with the conventional case.

<A> Replacement of Support When the support 3 is deformed due to a large-scale rock fall, the support 4 is removed and replaced with a new support 3. Even if the column 3 is deformed, the work of removing the column 3 by damaging the foundation concrete 1 is unnecessary.

[0030]

Embodiment 2 Hereinafter, another embodiment will be described. In the description, the same portions as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 5 shows another embodiment in which a known shock absorber 6 is interposed between the column 3 and the stay rope 7. The operation and effect of this embodiment are the same as those of the first embodiment.

[0032]

Third Embodiment FIG. 6 shows an application example of the first embodiment, in which a plurality of shock absorbers 6a and 6b are provided in a column 3 in series.
Another embodiment in which the stay rope 7 is held by the plurality of shock absorbers 6a and 6b is shown.

[0033]

Fourth Embodiment FIG. 7 shows an application of the first and third embodiments. In addition to the shock absorbers 6a and 6b provided on the column 3, a shock absorber 9c is arranged on the foundation concrete 1. ,
Another embodiment in which a retaining rope 7 is arranged and gripped in series between these shock absorbers 6a to 6c is shown.

[0034]

As described above, the present invention has the following effects. <A> The lower portion of the support is tiltably erected through the hinge, so that the bending moment does not act on the support almost but acts as a compressive force toward the pivot. For this reason, it is only necessary to have a buckling strength enough to counteract the compressive force accompanying the action of the impact force when designing the strut,
The struts can be designed with low strength. <A> In the present invention, as the column tilts, the overturning moment acting on the column becomes smaller, and the falling moment of the same basic concrete as the shock absorbing fence becomes smaller, so that the load on the basic concrete can be reduced as compared with the conventional case. . <C> Since the damping effect of the impact energy is determined not by the bending deformation of the support but by the damping effect of only the shock absorber, it is possible to easily and accurately obtain the damping performance by calculation without considering the deformation of the support it can. <D> Since the lower part of the column has a hinge structure, damage to the column can be reduced, and when replacing the column, there is no need to break the foundation concrete, and the replacement operation can be performed easily and easily. <E> The anchoring position of the stay rope on the mountain side is closer to the pillar side, so that the anchor fixed on the mountain side apart from the foundation concrete can be omitted, and it is not necessary to secure land from the pillar position to the anchor anchoring position . <F> By holding the retaining rope in the corrugated groove formed in the shock absorber, the energy damping effect due to the forced bending and return of the retaining rope is smaller than when the retaining rope is gripped by a linear groove. As a result, the damping efficiency increases.

[Brief description of the drawings]

FIG. 1 is a model diagram of a shock absorbing fence according to Embodiment 1.

FIG. 2 is an explanatory view of a shock absorber.

FIG. 3 is a sectional view of a shock absorber.

FIG. 4 is an explanatory view of a falling moment.

FIG. 5 is a model diagram of a shock absorbing fence according to the second embodiment in which a shock absorber is provided between a support post and a stay rope.

FIG. 6 is a model diagram of a shock absorbing fence according to a third embodiment in which a plurality of shock absorbers are provided on a support.

FIG. 7 is a model diagram of a shock absorbing fence according to a fourth embodiment in which a shock absorber is also provided on the foundation concrete.

FIG. 8 is a model diagram of a shock absorbing fence based on the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Foundation concrete 2 Bracket for mounting a support 3 Support 4 Axle (pivot part) 5 Wire rope 6 Shock absorber 7 Staying rope 8 Anchor 9, 9 Clamp body 10 Corrugated groove 11 Bolt 12 Nut

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[Procedure amendment]

[Submission date] March 15, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

In the present invention, the lower part of the column 3 has a hinge structure,
I tried to be proactive. This By tilting in column 3 is along the direction of action of the impact force of falling rock, etc., greatly reduces the bending moment acting on the strut 3, the bending mode
The purpose is to prevent the transfer of the cement to the foundation concrete 1 and to improve the exchangeability of the columns 3.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction contents]

[0033]

Fourth Embodiment FIG. 7 shows an application of the first and third embodiments. In addition to the shock absorbers 6a and 6b provided on the column 3, a shock absorber 9c is arranged on the foundation concrete 1. ,
Another embodiment in which a retaining rope 7 is arranged and gripped in series between these shock absorbers 6a to 6c is shown. It should be noted that
In each of the embodiments, the anchor 8 is placed immediately below the support 3.
Provided, and the stay rope 4 may be arranged inside the pillar 3.
Of course.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kazuo Minami, 2-11-4 Yaesu, Chuo-ku, Tokyo Inside Tohei Kanemori Co., Ltd. (72) Masaki Kasama 5-5 Kimachi, Takaoka-shi, Toyama Teikoku Metals Co., Ltd. In-house

Claims (6)

[Claims] 1. A wire rope or a net is stretched between supports erected at predetermined intervals on a foundation concrete,
At the shock absorbing fence where the stay rope is connected between the upper part of the support and the anchor, a shock absorber is provided to grip the stay rope at the upper part of the support, at the middle of the stay rope, or between the stay rope and the anchor so that the stay rope can slide. An impact absorbing fence, wherein a lower portion of the column is pivotally supported via a hinge so that the column can be tilted without transmitting a bending moment to the column. 2. The shock absorbing fence according to claim 1, wherein an anchor is provided on the same foundation concrete as the shock absorbing fence, and an end of a stay rope connected to a support is connected to the anchor. , Shock absorbing fence. 3. The shock absorbing fence according to claim 1, wherein a plurality of shock-absorbing members for gripping the stay rope in a permissible manner are provided in series on the column, and each of the shock-absorbing members grips the stay rope. A shock absorbing fence characterized by the following. 4. The shock absorbing fence according to claim 3, wherein a buffer is provided on the foundation concrete so as to allow the stay rope to slide, and a plurality of buffers provided on the pillar and the buffer on the foundation concrete. A shock absorbing fence characterized by holding a restraining rope between components. 5. The shock absorbing fence according to claim 1, wherein the shock absorber has a corrugated groove for accommodating the retaining rope, and the retaining rope is gripped along the corrugated groove. A shock absorbing fence characterized by the following. 6. A wire rope or a net is stretched between columns erected at predetermined intervals on the foundation concrete,
A stay rope is connected between the upper part of the support and the anchor, and the stay rope is slidably gripped by a shock absorber provided on the upper part of the support or in the middle of the stay rope or between the stay rope and the anchor. A shock absorbing method for absorbing an impact acting on a column by frictional resistance between a tool and a stay rope, wherein the impact acting on a column is used by using the impact absorbing fence according to any one of claims 1 to 5. While receiving a part of the force as a compressive force toward the pivot of the column, the frictional resistance between the buffer and the stay rope while tilting the column around the pivot without transmitting the bending moment to the column A shock absorbing method characterized by absorbing shock.