JP7152007B2 - Falling rock protection fence - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rockfall protection fence, and more particularly to a rockfall protection fence capable of efficiently absorbing impact energy caused by falling rocks.

An example of a rockfall protection fence for preventing rockfall onto a road or the like is disclosed in Patent Document 1. Hereinafter, this falling rock protection fence will be referred to as a conventional protection fence, and will be described with reference to the drawings.

6 is a partially omitted perspective view showing a conventional protective fence, FIG. 7 is a partially enlarged view showing a conventional protective fence, and FIG. 8 is a view of FIG.

6 to 8, 1 is a pair of terminal supports constructed on a slope where rockfall may occur, 2 is a plurality of intermediate supports constructed between the terminal supports 1, and 3 is the terminal support 1. and a plurality of wires stretched over the mountain side of the intermediate support 2 (see FIG. 6) at intervals in the vertical direction, 4 is a wire mesh stretched over the entire surface of the mountain side of the wire 3, 5 is the wire 3 It is a spacing member that maintains the vertical spacing.

The wire 3 is composed of a rock-receiving wire 3a and a buffer wire 3b connected to both ends of the rock-receiving wire 3a and having a smaller longitudinal elastic modulus than the rock-receiving wire 3a. ing.

As shown in FIGS. 7 and 8, the spacing member 5 is made of plate-shaped steel and is fixed to the mountain side of the spacing member 5 with U bolts 6 .

According to the conventional protective net configured in this way, the impact energy of the rock receiving wire 3a and wire netting 4 received by falling rocks is transferred to the terminal post 1 via the buffer wire 3b connected to both ends of the rock receiving wire 3a. However, as a result of the impact energy being absorbed by the elongation of the buffer wire 3b and wire netting 4, the tension applied to the terminal post 1 is greatly reduced. Furthermore, the impact energy is directly transmitted to the rock receiving wire 3a which has not received falling rocks due to the action of the spacing member 5, and as a result, the effect of absorbing the impact energy is further enhanced.

JP 2011-47154 A

According to the conventional protective fence described above, although it is possible to appropriately absorb the impact energy caused by falling rocks, there are the following problems.

Since the wire 3 is fixed to the spacing member 5 by the U bolt 6, the vertical spacing of the wire in the spacing member 5 is maintained, while the wire 3 is kept straight by the U bolt 6. Since the wire 3 is fixed to the space holding member 5 only by being pressed by the holding member 5, the wire 3 easily slides in its longitudinal direction. As a result, there is a risk that the wire 3 will be stretched excessively by the impact energy of the falling rock, and the falling rock will break the wire mesh 4 and fall onto the road.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to limit the elongation of the wire due to the impact energy of falling rocks by appropriately increasing the fixing strength of the wire to the spacing member, and to prevent the wire from being fixed to the spacing member by the impact of the falling rock. To provide a falling rock protection fence capable of efficiently absorbing impact energy caused by falling rocks by appropriately moving up and down by energy.

The present invention has been made to achieve the above objects, and is characterized by the following.

The invention according to claim 1 comprises a pair of terminal struts built on a slope where rockfall may occur, a plurality of intermediate struts constructed between the terminal struts, and the terminal struts and the intermediate struts. A plurality of wires stretched along the mountain side at intervals in the vertical direction, a wire mesh stretched over the entire surface of the mountain side of the wire, and a direction orthogonal to the wire that maintains the vertical interval of the wire. In the rockfall protection fence provided with a space keeping member, the space keeping member is made of a deformed steel bar in which a large number of projections are formed on the outer peripheral surface of the round steel bar at intervals in the longitudinal direction of the round steel bar . , The wire stretched over the crest side of the deformed steel bar is pressed against the deformed steel bar by fitting a washer into a U-bolt arranged across the wire on both sides of the deformed steel bar and tightening the U-bolt with a nut. It is characterized in that it is held and fixed.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the washer is formed with recesses for deformed steel bars into which the deformed steel bars enter.

The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the washer is formed with a wire recess into which the wire is inserted.

The invention according to claim 4 is characterized in that, in the invention according to any one of claims 1 to 3, the wire mesh and the wire are connected by a coil.

According to this invention, by increasing the fixing strength of the wire to the spacing member, the elongation of the wire due to the impact energy of falling rocks is appropriately restricted, so that the impact energy due to falling rocks can be efficiently absorbed.

In addition, according to the present invention, the portion where the wire is fixed to the spacing member can be properly moved up and down by the impact energy of falling rocks, so the impact energy due to falling rocks can be efficiently absorbed.

1 is a partial front view showing a falling rock protection fence of the present invention; FIG. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; FIG. 2 is an enlarged view of part P in FIG. 1; It is an A direction view of FIG. It is a B direction view of FIG. It is a partially omitted perspective view showing a conventional protection fence. It is a partially enlarged view showing a conventional protective fence. FIG. 8 is a view in the direction of A in FIG. 7;

One embodiment of the falling rock protection fence of the present invention will be described with reference to the drawings.

1 is a partial front view showing a rockfall protection fence of the present invention, FIG. 2 is a cross-sectional view along the line AA of FIG. 1, FIG. 3 is an enlarged view of P part of FIG. 1, and FIG. 4 is A of FIG. FIG. 5 is a direction view of FIG. 3. FIG.

As shown in FIGS. 1 to 5, the rockfall protection fence of the present invention is constructed between a pair of terminal struts 1 (see FIG. 6) constructed on a slope where rockfall may occur, and between the terminal struts 1. A plurality of intermediate struts 2, a plurality of wires 7 stretched at intervals in the vertical direction along the crest sides of the terminal struts 1 and the intermediate struts 2 (see FIG. 6), and the entire crest side of the wires 7 are stretched. and a deformed steel bar 8 as a space retaining member arranged in a direction perpendicular to the wire 7 to keep the vertical space between the wires 7. As shown in FIG. The upper end of the deformed steel bar 8 is bent in a U shape and hung on the uppermost wire 7 .

A feature of the present invention is that the spacers are made of deformed steel bars 8 . The deformed steel bar is a round steel bar having a large number of protrusions 8a (see FIGS. 3 and 4) formed on the outer peripheral surface thereof at intervals in the longitudinal direction of the round steel bar.

In order to fix the wire 7 stretched on the crest side of the deformed steel bar 8 as a spacing member to the deformed steel bar 8, U bolts 9 are arranged across the wire 7 on both sides of the deformed steel bar 8, and the U bolt 9 is A plate-shaped washer 10 having a bolt hole 10a is fitted, and a U-bolt 9 is tightened with a nut 11. As shown in FIG. Thus, the wire 7 is pressed against the deformed steel bar 8 and fixed.

The deformed steel bar recess 10b into which a part of the deformed steel bar 8 is inserted is formed in the washer 10, so that the positional displacement of the deformed steel bar 8 with respect to the washer 10 is suppressed.

In this way, by fixing the wire 7 to the deformed steel bar 8 with the U bolt 9, the wire 7 climbs over the deformed steel bar 8 and deforms into a U shape as shown in FIG. Since it is sandwiched between the U-bolt 9 and the washer 10 and fixed to the deformed steel bar 8, the fixing strength of the wire 7 to the deformed steel bar 8 is increased. As a result, the elongation of the wire 7 due to the impact energy of falling rocks is appropriately restricted compared to the case where the wire 7 is fixed without being deformed, so that the impact energy due to falling rocks can be efficiently absorbed.

By restricting the elongation of the wire 7 in this way, the deformation of the coil 12 (see FIG. 1) connecting the wire 7 and the wire mesh 4 can be suppressed. can also be suppressed.

Since the wire recess 10c into which the wire 7 is inserted is formed in the washer 10, the displacement of the wire 7 with respect to the washer 10 is suppressed, and the amount of deformation of the wire 7 at the deformed steel bar 8 is increased. Cheap.

In addition, since the fixed portion of the wire 7 to the deformed steel bar 8 can be properly moved up and down by the impact energy of falling rocks, the impact energy due to falling rocks can be efficiently absorbed. That is, since the projections 8a are formed on the deformed steel bar 8, the wire 7 is less likely to move up and down compared to the case where the projections 8a are not formed. Therefore, when an impact energy exceeding a predetermined magnitude acts on the wire 7, the wire 7 moves up and down, so that the impact energy can be absorbed.

As described above, according to the present invention, by increasing the fixing strength of the wire 7 to the deformed steel bar 8 as the spacing member, the elongation of the wire 7 due to the impact energy of falling rocks is appropriately limited. It can efficiently absorb the impact energy caused by falling rocks.

In addition, according to the present invention, the portion where the wire 7 is fixed to the deformed steel bar 8 serving as a spacing member can be moved up and down appropriately by the impact energy of falling rocks, so the impact energy due to falling rocks can be efficiently absorbed in this respect as well. can do.

1: Terminal post 2: Intermediate post 3: Wire 3a: Rock receiving wire 3b: Buffer wire 4: Wire mesh 5: Spacing material 6: U bolt 7: Wire 8: Deformed steel bar 8a: Projection 9: U bolt 10: Washer 10a : bolt hole 10b: concave portion for deformed steel bar 10c: concave portion for wire 11: nut 12: coil

Claims (4)

A pair of terminal struts built on a slope where rockfall may occur, a plurality of intermediate struts constructed between the terminal struts, and a space between the terminal struts and the intermediate struts along the mountain side in the vertical direction. It comprises a plurality of wires stretched with a gap, a wire mesh stretched over the entire mountain side of the wire, and a spacing member arranged in a direction perpendicular to the wire to retain the vertical spacing of the wire. At the rockfall protection fence,
The spacing member is a deformed steel bar in which a large number of projections are formed on the outer peripheral surface of the round steel bar at intervals in the longitudinal direction of the round steel bar ,
The wire stretched over the crest side of the deformed steel bar is pressed against the deformed steel bar by fitting a washer into a U-bolt arranged across the wire on both sides of the deformed steel bar and tightening the U-bolt with a nut. A falling rock protection fence characterized by being fixed by 2. The rockfall protection fence according to claim 1, wherein the washer is formed with a recess for a deformed steel bar into which the deformed steel bar enters. 3. The rockfall protection fence according to claim 1, wherein said washer is formed with a recess for wire into which said wire is inserted. The rockfall protection fence according to any one of claims 1 to 3, wherein the wire mesh and the wire are connected by a coil.

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