JP3457583B2 - Rockfall protection fence - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rockfall protection fence that can cope with large-scale rockfalls.

[0002]

2. Description of the Related Art Conventionally, as means for preventing damage to a facility such as roads, railways, houses, etc. provided on sloped areas such as mountainous areas due to falling rocks, for example, as shown in FIG. A rockfall prevention fence 60 in which pillars 61 made of H-shaped steel or the like are erected on a hillside at a predetermined interval and a wire rope 62 made of steel and a wire net 63 are laterally provided between the pillars 61 to form a wall surface It is used.

However, the rockfall prevention fence 60 shown in FIG.
The mechanism for absorbing the kinetic energy of the rockfall in is based on the deformation of the wall surface composed of the steel wire rope 62 and the wire net 63 and the pillar 61 such as H-section steel, and both of them have rigidity. Since it is a member, the absorbed energy obtained by deformation is 4 to 6 t.
It is as low as f ・ m.

Therefore, for example, the diameter is 1.5 m (weight is about 5
In the event of an accident in which a relatively large-scale rock exceeding about t) falls about several meters, there is a problem that the rockfall prevention fence cannot support it.

[0005]

[Patent Document 1] Japanese Patent Laid-Open No. 7-5431 discloses a rockfall protection fence that can cope with large-scale rockfalls.
According to Japanese Patent Laid-Open No. 6, a rope material made of steel is laid horizontally in a multi-stage manner between columns that are erected at intervals, and when a shock such as a rock fall is received, the rope material is slid by a shock absorber. A shock absorbing fence that absorbs the shock of falling rocks is disclosed.

However, in the shock absorbing fence disclosed in the above-mentioned publication, once a rock fall occurs, not only the rope material at the portion plastically deformed by the impact of the rock fall but also a wide shock absorbing device for sliding the rope material, etc. It is necessary to replace a large number of parts within the range. In addition, there is also a problem that replacement work is difficult because the entire length of each rope material is long and the structure of the rope attachment device and the shock absorber are complicated.

Further, in the shock absorbing fence disclosed in the above publication,
Although a maximum of 50tf · m of absorbed energy can be obtained by sliding the rope material by the shock absorber and the deformation of the pillar, as mentioned above, rocks of about 5t usually fall a distance of more than 10m before falling rocks. Considering the collision with the guard fence, the absorbed energy of about 50 tf · m is still insufficient.

On the other hand, as a rockfall protection fence that can cope with large-scale rockfall, a net formed by continuously connecting steel rings is suspended by a steel rope, and mainly used. There is also known a so-called ring net protection shelf that absorbs the kinetic energy of rockfall with this net.

According to this ring net protection rack, a maximum of 150 tf · m of absorbed energy can be obtained by the deformation of the ring itself and the sliding of the rope suspending the ring.

However, in the ring net protection shelf, once a rockfall occurs, it is necessary to replace the ring that has been plastically deformed by the impact of the rockfall. In this case,
It is difficult to replace individual rings, and extensively the entire ring net must be replaced.

Further, the shock absorbing fences and the ring net protection shelves disclosed in the above publications have complicated structures,
Due to the large number of parts, not only the replacement work after being subjected to plastic deformation but also the construction work itself is complicated and involves difficult work. There is also a problem that the cost for maintenance such as repair and maintenance also becomes high.

[0012] Therefore, the object of the present invention is to have a sufficient shock absorbing ability, easy construction and maintenance,
It is to provide an inexpensive rock fall protection fence.

[0013]

MEANS FOR SOLVING THE PROBLEMS AND EFFECTS OF THE INVENTION The present inventors have conducted extensive studies to solve the above problems. Surprisingly, when a wall material made of flexible plastic is laid horizontally, it is surprisingly possible to obtain a completely new rockfall protection fence that has absorbed energy that can cope with relatively large-scale rockfalls. As a result of discovering the facts and conducting further studies, the present invention has been completed.

That is, the first rockfall protection fence according to the present invention is a strip of flexible plastic reinforced by chemical fibers, which is laid horizontally in multiple stages between columns that are erected at intervals. It is characterized by being.

The second rockfall protection fence according to the present invention is
It is characterized in that a mesh member made of a flexible plastic reinforced by a chemical fiber is laid horizontally between columns which are erected at intervals.

In the above-mentioned first and second rockfall protection fences, among the members constituting the fence, only the support columns are rigid members, and the wall material that mainly absorbs the impact of rockfalls has strength and deformability. Flexible plastic strips or nets reinforced with superior chemical fibers are used.

The wall material is a flexible plastic strip member or net member reinforced with chemical fibers having excellent strength and deformability as described above, and in addition to having sufficient strength itself. Therefore, the impact energy of rockfall can be absorbed even when the wall material itself is greatly stretched, so that the wall material as a whole has extremely high absorbed energy.

Moreover, such a wall material is lower in cost than steel ropes and wire nets used for conventional rockfall protection fences, and is also lighter in weight than steel ropes. Good workability during construction, such as carrying in during construction.

Further, unlike the conventional steel ropes and wire nets, this wall material is made of a flexible plastic excellent in corrosion resistance, so that it is not necessary to be subjected to rust prevention treatment or the like and is deteriorated with time. Few.

Further, according to the rockfall protection fence according to the present invention, even if the wall material is deformed by absorbing the kinetic energy of rockfall, the wall material basically undergoes plastic deformation (the strip member or Just remove the mesh member) from the column and attach a new wall material to the location,
The rockfall guard fence can be reused. Moreover, according to the present invention, since the structure of the wall material itself is simple,
The wall material replacement work is simple, and it is not necessary to replace the wall material over a wide area of the rockfall protection fence.

Therefore, the burden associated with the replacement work of the protective fence is reduced, and even if the wall material is replaced, since the wall material is lightweight as described above, maintenance such as replacement work can be easily performed. You can

The first rockfall protection fence may be provided with a stringer made of flexible plastic reinforced by chemical fibers. In this case, since the wall material has a net-like shape like the second rockfall protection fence, the absorbed energy can be further improved.

As described above, according to the rockfall protection fence according to the present invention, from the medium-sized rockfall to the large-scale rockfall, it exerts an extremely high energy absorbing action on the kinetic energy of the rockfall, and is sufficient for the rockfall. Exerts a buffering effect. Therefore, the rockfall protection fence according to the present invention has a remarkable effect of preventing rockfall damage to facilities such as roads, railways, and houses below the rockfall protection fence. The rockfall protection fence according to the present invention can not only protect equipment such as roads, railroads, and houses below the fence from damage by falling rocks, but also protect damage from falling trees and avalanches.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The rockfall protection fence according to the present invention will be described in more detail below.

[First Rock Fall Guard Fence] The first rock fall guard fence according to the present invention is reinforced by chemical fibers between columns 11 standing at intervals as shown in FIG. 1, for example. A strip-shaped member 12 made of a flexible plastic is horizontally arranged in multiple stages.

The belt-shaped member 12 is formed by molding a plurality of high-strength chemical fibers 13 in the shape of an endless belt, and covering the surface of the plastic 14 with flexibility. Since the belt-shaped member 12 itself has a ring shape in this manner, the belt-shaped member 12 is attached to the support column 1 when the rockfall protection fence is constructed.
All you have to do is to hang it up between 1 and 10 by the simple method.
Can be obtained. Moreover, since the wall material is substantially doubled, the absorbed energy can be further increased.

The first rockfall protection fence may be, for example, as shown in FIG. 2, only the end portion 25 of the belt-shaped member 22 has a ring shape. Also in this case, as in the case shown in FIG. 1, the rockfall protection fence 20 can be obtained by a simple method in which the strip-shaped member 22 is hung between the columns 11.

The belt-shaped member 12 and the belt-shaped member 22 are
It is also possible to make the belt-shaped member endless belt-like by using bolts or clips, or to form the end into a ring shape, but the wall material is stretched by the impact of the rockfall and the load of the rockfall, Considering that this absorbs the impact of rockfall, it is not preferable to use bolts or clips. Therefore, it is preferable to preliminarily form an endless belt shape or an end portion into a ring shape when manufacturing the belt-shaped member.

Further, the first rockfall protection fence is, for example, as shown in FIG.
In addition, a vertical bar 33 made of a flexible plastic reinforced by chemical fibers may be provided.

As such a vertical member, the same member as the strip-shaped member in the rockfall protection fence shown in FIG. 1 or 2 can be used. For example, among the strip-shaped members 32 horizontally extended in multiple stages, the lowermost stage 32a and the uppermost stage. The columns of 32b are 11
Before being laid horizontally between them, the belt-shaped member 33 that serves as a vertical element beforehand
By passing through the strip-shaped members of the lowermost stage 32a and the uppermost stage 32b, it is possible to finally obtain the rockfall protection fence 30 having the lattice-shaped wall material as shown in FIG. When forming the lattice-shaped wall material, the shape of the lattice can be set to various shapes such as plain weave and twill weave.

The strip-shaped member serving as the vertical member can be integrated with the strip-shaped member laterally mounted between the columns 11 by using bolts, but the wall material is stretched by the impact of rockfall or the load of rockfall. However, considering that the impact of rockfall is absorbed by this, integration using bolts is not preferable. Therefore, similarly to the strip-shaped member in the rockfall protection fence shown in FIG. 2, it is preferable that the end portion 35 of the strip-shaped member 33, which is a vertical member when the strip-shaped member is manufactured, be formed into a ring shape in advance.

[Second Rockfall Guard Fence] The second rockfall guard fence according to the present invention is strengthened by chemical fibers between columns 11 standing at intervals as shown in FIGS. 4 and 5, for example. The mesh members 42, 52 made of flexible plastic are horizontally mounted.

The mesh member 42 shown in FIG. 4 is (a) an endless belt shape obtained by molding a plurality of high-strength chemical fibers into an endless belt shape and coating the surface thereof with a flexible plastic. A plurality of strip-shaped members arranged in parallel, and each strip-shaped member is appropriately connected with a flexible plastic to form a mesh-shaped member as a whole, or (b) a plurality of high-strength chemical fibers A woven fabric composed of an endless belt-like weft and warp yarns inserted into the weft yarn at a predetermined interval, the surface of which is covered with a flexible plastic.

On the other hand, the reticulated member 52 shown in FIG. 5 is not one in which the high-strength chemical fiber is formed into an endless belt shape, but is formed into a ring shape only in the end portion, and the above (a) and ( This is similar to the mesh member 42 shown in b).

Using the mesh members shown in FIGS. 4 and 5,
In either case, the rockfall protection fences 40 and 50 can be obtained by a simple method in which the endless belt-shaped net member 42 or the end of the net member 52 is hung between the columns 11.

[Band-Shaped Member and Net-Shaped Member] A strip-shaped member and a net-shaped member made of a flexible plastic reinforced by chemical fibers used in the present invention (hereinafter, the strip-shaped member and the net-shaped member are collectively referred to as “flexible plastic member”). ".)
Is a plurality of chemical fibers coated with a flexible plastic.

The flexible plastic member is required to have excellent proof strength and elongation in order to sufficiently absorb the impact of rock fall.

(Chemical fiber) The chemical fiber used as a reinforcing material for the flexible plastic member has a high strength such as tensile strength of the flexible plastic member and can be freely deformed in response to the impact of rockfall. Thus, it is also required to impart sufficient elongation to the flexible plastic member.

The chemical fiber used in the present invention is not particularly limited except that it has sufficient tensile strength and elongation, and examples thereof include polyester fiber, polyethylene fiber, polypropylene fiber, nylon fiber, aramid fiber, vinylon fiber and the like. The chemical fiber of can be used.

Since the absorbed energy of the rockfall protection fence increases in proportion to the elongation rate of the chemical fiber, although the chemical fiber whose elongation rate is as large as possible is preferably used, it depends on the location conditions of the rockfall protection fence. The growth rate may be limited. That is, for example, when the distance from the rockfall protection fence to a road or a facility such as a house is short, even if the absorbed energy is small, the wall material (flexible plastic member) of the rockfall protection fence stretched by the rockfall is the road. ,
It is necessary to limit the elongation rate of the chemical fiber so that it will not come into contact with the house.

(Flexible plastic) As with the chemical fiber, the flexible plastic for covering the chemical fiber is required to have excellent strength and sufficient elongation. Specifically, since the type of suitable resin varies depending on the type of chemical fiber used in the present invention, it is not particularly limited, but in general, polyethylene, polyester, polypropylene, nylon, etc. Various conventionally known plastics can be used.

An ultraviolet absorber, a colorant and the like can be added to the above flexible plastic. In particular, since the rockfall protection fence is used outdoors, particularly in a place where there is a lot of sunlight irradiation, it is preferable to blend an ultraviolet absorber into the belt-shaped member to prevent its photodegradation.

(Flexible Plastic Member) Specific examples of the flexible plastic member usable in the present invention include: Fiber-reinforced plastic belts (Maeda Kosen Co., Ltd.)
Made of "TTF series", multiple high-strength polyester fibers coated with polyethylene resin, tensile strength 10
tf, elongation 15%] ・ Multiple woven fabric made of polyester fiber [Company's stretch mat "EL series"] ・ High-strength polyester fiber "Tetron (R)" plain weave ・ Multiple fabric [Teijin (R) made by the same company] Civil engineering sheet "T series"] (both Tetron (R) and Teijin (R) are registered trademarks of Teijin Ltd.) and the like.

[Post] As the post, various conventionally known ones such as steel pipes and H-shaped steel can be used. Among them, the ends are formed in a ring shape or the whole is formed in an endless belt shape. From the viewpoint of operability when fixing the flexible plastic member, it is preferable to use a steel pipe. From the viewpoint of strength, it is preferable to use a steel pipe having a hollow inside.

The column spacing is not particularly limited,
It is set according to the size of rockfall that can be usually assumed, the length of the flexible plastic member, or the like. Generally, the wider the strut spacing, the higher the flexibility of the flexible plastic member, and the effect of absorbing the kinetic energy of rockfall by the expansion of the flexible plastic member can be sufficiently exerted.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a rockfall protection fence according to the present invention.

FIG. 2 is a perspective view showing another embodiment of a rockfall protection fence according to the present invention.

FIG. 3 is a perspective view showing still another embodiment of a rockfall protection fence according to the present invention.

FIG. 4 is a perspective view showing still another embodiment of a rockfall protection fence according to the present invention.

FIG. 5 is a perspective view showing still another embodiment of a rockfall protection fence according to the present invention.

FIG. 6 (a) is a front view showing a conventional rockfall protection fence, and FIG. 6 (b) is a side view thereof.

[Explanation of symbols]

10, 20, 30, 40, 50 Rockfall protection fence 11 props 12, 22, 32 Band-shaped members 33 Vertical child 42,52 mesh members

Claims (3)

(57) [Claims] 1. A rockfall protection fence in which strips made of flexible plastic reinforced by chemical fibers are horizontally extended in a multi-stage manner between columns provided at intervals. 2. The rockfall protection fence according to claim 1, further comprising a stringer made of a flexible plastic reinforced by chemical fibers. 3. A rockfall protection fence in which a mesh member made of a flexible plastic reinforced by chemical fibers is laterally installed between columns provided at intervals.