JP4410743B2 - Shock absorbing fence - Google Patents

Description

The present invention relates to an impact absorbing fence that can be used both as an avalanche prevention fence and a rockfall protection fence.

  In general, the avalanche prevention fence and the rockfall protection fence differ in the range and magnitude of the force acting on the net surface, while the former acts on a wide area of the net surface, while the latter acts on the net surface. A big impact acts on the local area.

  Based on these differences, the avalanche prevention fence is joined by linking many steel beams across the front surface between a plurality of steel main members erected at intervals on the slope, and the back of the main material. A steel diagonal is arranged between the slope and the slope so that the snow pressure acting on the beam can be supported by the support and the diagonal.

In addition, a rock fall protection fence as shown in FIG. 7 has been proposed as a small and medium-sized protection fence.
This rock fall protection fence is constructed by standing steel struts 70 at a predetermined interval on the mountainside or road side, and horizontally laying a plurality of rope members 71 on each adjacent strut 70 in a multistage manner. Both ends are fixed to the strut 70, and a net member 72 is attached to the rope member 71, and the impact energy held by the falling rock is absorbed by the rigidity of the strut 70 and the deformation of the rope member 71 and the net member 72 to stop the falling stone. It has become.

The conventional prevention fence described above has the following problems.
(1) As described above, the avalanche prevention fence and the rockfall protection fence are used differently depending on the usage because the load application method and the shock absorption system are different. Installation of various types of fences is compelling and installation costs are extremely high.
(2) If an avalanche prevention fence is used as a rockfall protection fence, the rockfall impact force acting on a narrow net surface will be concentrated on the pillar, which may cause the pillar to be deformed and destroyed or removed from the slope. The protective fence can be easily destroyed.
Therefore, many improvements are required to apply the conventional avalanche prevention fence to the falling rock protection fence as it is.
(3) In the rock fall protection fence shown in FIG. 7, since the rope material 71 is connected for every span of the support column 70, the fall rock A shown by the two-dot chain line in the vicinity of the support column 70 as shown in FIG. If there is a collision, an excessive load acts on the connecting member 73 that fixes the rope member 71, and the rope member 71 and the connecting member may be destroyed.
Further, when the falling rock collides with the vicinity of the support column 70, the rope material 71 is connected to each span of the support column 70, so that the deformation amount of the rope material 71 is reduced, so that the generated impact force is increased and the protective fence is increased. Is easily destroyed.
(4) In the rock fall protection fence shown in FIG. 7, the rope material 71 is disposed on the slope upper side with respect to the support column 70, and the net material 72 is disposed on the slope upper side with respect to the rope material 71. When the falling rock collides, there is a problem that the net member 72 and the rope member 71 are sandwiched between the falling rock and the support 70 and are easily cut.
(5) Another type of protective fence for falling rocks is a protective fence in which a rope material is stretched only at the top and bottom edges, and a special protective net knitted in a ring or lattice shape with a strong wire between them. ing.
In the case of this protective fence, there is a problem that the construction cost of the protective fence is high because the protective net is expensive.

This invention is made | formed in view of the above point, The place made into the objective is to provide the impact-absorbing fence which can serve as an avalanche prevention fence and a falling rock protection fence.
Furthermore, the object of the present invention is to stop the collision object without breaking the fence even if the collision object collides with the vicinity of the support column, and the impact that the net surface is not greatly deformed even during snowfall in winter. It is to provide an absorption rail.

The first invention of the present invention is an impact absorbing fence configured by horizontally laying a rope material between struts erected at intervals, and the rope material is disposed on the opposite side of the colliding object with respect to the strut. Then, the rope material is attached to the support through a holding release device that releases the holding of the rope material when a certain lateral force acts on the rope material, and the holding release device pivots on the support. The shock absorbing fence is made of a plate and is provided with a rotation resistance to the pivotal support portion of the rotation plate .
1st invention of this invention is an impact-absorbing fence comprised by laying a rope material in multiple steps between several support | pillars standing upright at intervals, and it is located between the highest and lowest end rope materials. The intermediate rope member is fixed to the end struts, and the intermediate rope member is disposed on the side opposite to the collision object entry side with respect to the intermediate struts located between the end struts. The intermediate rope member is attached to the intermediate column through a holding release device that releases the holding of the intermediate rope member when a force is applied, and the holding release device comprises a rotating plate pivotally supported on the column. It is an impact-absorbing fence characterized by providing rotational resistance to the pivotal support portion of the plate .
A third invention of the present application is the shock absorbing fence according to the second invention, wherein the uppermost and lowermost end rope members are attached to the intermediate struts in an inseparable manner.
A fourth invention of the present application is the impact absorbing fence according to any one of the first to third inventions, wherein a net material is attached to a plurality of rope materials.
A fifth invention of the present application is the shock absorbing fence according to any one of the first to fourth inventions, wherein a shock absorber is interposed in the rope material.

  A sixth invention of the present application is the shock absorbing fence according to any one of the first to fifth inventions, wherein a spacing member is attached between the plurality of rope members.

According to a seventh invention of the present application, in any one of the first to sixth inventions, the holding release device includes a rotating plate pivotally supported on the mounting bracket of the support, and a resistance pin penetrated through the rotating plate and the mounting bracket. The shock absorbing fence is configured to constrain free rotation of the rotating plate by the shear strength of the resistance pin and to allow rotation of the rotating plate by breaking the resistance pin. It is.

The present invention can obtain the following effects.
(1) One type of shock absorbing fence can cope with both avalanches and falling rocks.
(2) At the time of snow pressure action due to snow, the lateral force of the rope material can be transmitted to the intermediate strut like the existing shock absorbing fence, but when the collision object such as falling rock collides, the rope material comes off from the intermediate strut, Since the intermediate rope member is not connected to the intermediate column, it can be greatly deformed, and the energy absorption effect is great.
Therefore, the impact force is reduced, and the impact absorbing fence can be economically designed.
(3) Since it is not necessary to use a special protective net knitted in a ring shape or lattice shape with a strong wire, the construction cost of the shock absorbing fence can be kept low.
(4) Since the intermediate rope material and the net material are arranged on the side opposite to the collision object entry side with respect to the support column, the problem that the net material is sandwiched between the falling rock and the support column can be solved.
(5) The amount of energy that can be absorbed is further increased by placing an impact absorbing device on the rope material.

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

(1) Overview of the entire shock absorbing fence FIG. 1 is an overall view of the shock absorbing fence, and FIG. 2 is a side view thereof.
The shock absorbing fence is composed of a support column 10 erected on the mountainside or on the road side, a rope member 20 horizontally mounted on the support column 10, and a net member 30 attached to the rope member 20.

The strut 10 is composed of an end strut 10a located at the end, and an intermediate strut 10b located between the end struts 10a, and the rope material 20 is also positioned at the lowest position relative to the strut 10 respectively. It consists of the intermediate rope material 20b located between these end rope materials 20a. In the following explanation, the entire name and the individual name will be used separately as necessary.

(2) Prop (Fig. 1)
The strut 10 is a rigid member having a strength capable of resisting an impact force transmitted by the net member 30 and the rope member 20 when a collision object collides, and is spaced apart on the concrete retaining wall 40 and the slope shown in the figure. Standing up.

As the support | pillar 20, well-known raw materials, such as a synthetic structure body made from concrete, H-type steel materials, steel, such as a steel pipe, or the steel pipe filled with concrete, are included.
In addition, in order to increase the support force of the support column 20, a support rope is connected to the support column 20 or supported, or a rope is connected to a base plate provided at the lower end of the support column 20 without being embedded, and each rope is surrounded by It is also possible to connect and support the anchor fixed to the anchor.

(3) Rope material The end rope material 20a and the intermediate rope material 20b constituting the rope material 20 are both constituted by a wire rope or the like.

  The end rope member 20a and the intermediate rope member 20b are disposed on the opposite side of the strut 10 from the collision object entry side, and are fixed to the end strut 10a in common.

  The end rope member 20a and the intermediate rope member 20b are different from each other in the manner of attachment to the intermediate support column 10b as follows.

That is, the uppermost and lowermost end rope members 20a are connected to the intermediate strut 10b for each span. The “connection” in this case includes mooring in a state where the end rope member 20a is allowed to slide in the longitudinal direction, and the external force acting on the end rope member 20a is directly transmitted to at least the upper and lower portions of the intermediate strut 10b. It means a possible mounting form.
In this example, the end rope member 20a is inserted through the mooring hooks 11 provided on the upper and lower portions of the intermediate strut 10b, and the end rope member 20a is attached so as not to be separated from the intermediate strut 10b at the time of impact.

  The intermediate rope member 20b is held via a holding / releasing device 50 attached to the intermediate column 10b. Details of the holding release device 50 will be described later.

Further, when the middle is bent in the extension direction of the fence or the span length of the intermediate strut 10b becomes extremely long, the intermediate rope member 20b is directly connected to the intermediate strut 10b without using the holding release device 50. There is also.

(4) Auxiliary tool for rope material One or a plurality of impact absorbing devices 60 are interposed near or between the ends of the end rope material 20a and the intermediate rope material 20b.
The use of the impact absorbing device 60 effectively absorbs excessive impact energy acting on each rope member 20a, 20b, and exceeds the breaking strength at the connecting part or fixed part of each rope member 20a, 20b. This is because no load is applied.

  The impact absorbing device 60 allows the rope members 20a and 20b to slide in the tension acting direction when a tension higher than a predetermined value is applied to the rope members 20a and 20b, and attenuates the tension by the sliding resistance at this time. For example, in addition to a known frictional resistance type shock absorbing device, a device that uses fluid resistance such as an elastically deformable type or a damper can also be used.

  However, when the tension | tensile_strength resulting from the snow pressure at the time of snowing acts on rope material 20a, 20b, the frictional resistance of the shock absorber 60 is prevented so that it may not slide easily between rope material 20a, 20b and the shock absorber 60. It is important to set (the displacement start resistance of the rope material) in advance.

  When the impact energy is small or the rope length is long, the use of the impact absorbing device 60 may be omitted.

In addition, there may be a case where a spacing member 21 is attached so as to intersect between a plurality of rope members 20a and 20b that are horizontally mounted in a multi-stage manner to limit the spacing between the rope members 20a and 20b within a certain range.
In addition to the combination of the wire rope and the wire clip 22, a combination of the band steel plate and the wire clip, a chain, or the like can be applied to the spacing member 21.

(5) Net material The net material 30 that functions to capture the collision object passing between the rope materials 20a and 20b and appropriately maintain the distance between the main rope materials 20 is suitable for the expected impact force. For example, a known rhombus wire mesh having a rhombus mesh can be used, which is knitted so that a sufficient elongation ability can be exhibited using a wire having a property having a sufficient rigidity and strength.
The wire material for knitting the net material 30 is knitted with a single steel wire or a composite wire made by twisting a plurality of steel wires, and has sufficient strength and deformation capability to withstand the expected impact force. Is given.
As a means for attaching the net member 30 to the rope members 20a and 20b, in addition to the method of disposing the net member 30 on one side of the rope members 20a and 20b, the rope members 20a and 20b are inserted into the net member 30. Any method of arranging them may be adopted.
The overlapping portions of the net member 30 and the rope members 20a and 20b are connected using a known connecting tool or a spiral coil.

(6) Holding Release Device As described above, the intermediate rope member 20b is held by the intermediate support column 10b via the holding release device 50.

  The holding release device 50 maintains a state in which the intermediate rope member 20b is held by the intermediate strut 10b against a relatively small lateral force that is applied over a long period of time, such as snow pressure of snow or snow, and a falling rock collides. When a lateral force greater than the snow pressure is applied, the intermediate rope member 20b is released, and the intermediate rope member 20b is allowed to move greatly toward the opposite side of the collision object such as falling rocks. It can be a device.

  In short, the holding release device 50 connects the intermediate rope member 20b and the intermediate strut 10b so that the force can be transmitted until the lateral force acting on the intermediate rope member 20b reaches a set value. It is only necessary to have a function of releasing the connection between the intermediate rope member 20b and the intermediate strut 10b for the first time when the lateral force acting on the member 20b exceeds the set value.

The holding and releasing device 50 of this example will be described with reference to FIGS. 2 to 4. The holding and releasing device 50 is attached to the mounting bracket 13 protruding from the side surface of the intermediate column 10 b with one end of the rotating plate 51 by a fixing bolt 52 and a nut 53. The pivot plate 51 is pivotally supported so that the pivot plate 51 is provided with a predetermined rotation resistance.
An accommodation groove 54 capable of accommodating the intermediate rope member 20b is formed on one side surface of the rotating plate 51.

The opposing surfaces of the superposed mounting bracket 13 and the rotating plate 51 are formed as a frictional resistance surface 55 having radial irregularities as shown.
The unevenness of the frictional resistance surface 55 is not limited to a radial shape, and any shape can be applied, and hemispherical protrusions may be scattered. Alternatively, a high friction sheet may be attached to the opposing surfaces of the mounting bracket 13 and the rotation plate 51 to give a predetermined rotation resistance.

As a preferable fixing means of the pivotal support portion of the rotating plate 51, when the disc spring 56 is inserted into the fixing bolt 52 and tightened with the nut 53, the disc spring can be fixed with a stable clamping force using the spring force of the disc spring 56.
Furthermore, if the projection 57 is formed on the threaded portion of the fixing bolt 52 so that the tightening amount of the nut 53 can be regulated in accordance with the clamping force, clamping is performed via the disc spring 56 at the pivotal portion of each rotating plate 51. It is possible to keep the force constant.

The tightening torque of the nut 52 can be easily set to an arbitrary torque by selecting the rigidity of the disc spring 56 or selecting the formation position of the projection 57 of the fixing bolt. The limit holding force for starting the rotation can be easily set by appropriately selecting the rotational frictional resistance of the pivotal support portion of the rotation plate 51 and the tightening torque of the nut 52.

(7) Action of shock absorbing fence Next, the action of the shock absorbing fence at the time of the snow pressure action of snow and the falling rock collision will be described.

[Contrast shock absorbing fence]
In order to clarify the action of the shock absorbing fence according to the present invention, first, the action of the shock absorbing fence for comparison will be described.

In general, during snow accumulation, snow pressure due to creep or glide acts on the net surface formed by the rope member 20 and the net member 30 of the shock absorbing fence over a long period of time due to snow accumulation.
Here, assuming that the intermediate rope member 20b is not held by the intermediate strut 10b and the lateral force due to snow pressure is supported only by the uppermost and lowermost end rope members 20a, the uppermost and lowermost end ropes are assumed. Since the material 20a is connected to the end struts 10a and the intermediate struts 10b, the material 20a can support a lateral force due to snow pressure acting outside the net surface.
However, it is difficult to restore the net surface mainly composed of the intermediate rope member 20b that protrudes to the road side due to the lateral force due to the snow pressure after the snow is removed.
Therefore, in consideration of after snow removal, the intermediate rope member 20b is preferably connected to the intermediate support column 10b.

  Further, if the intermediate rope member 20b is completely fixed to the intermediate column 10b in consideration of snow extinguishing, the impact force is increased because the deformation of the net surface is restrained and the impact force is increased when the falling rock collides with the intermediate column 10b. There is a risk that the fence will be destroyed.

  The present invention was made in order to eliminate the above-mentioned inconvenience at the time of snow extinguishing and the inconvenience at the time of rockfall collision, and by attaching the intermediate rope member 20b to the intermediate strut 10b via the holding release device 50, the net surface Even if the magnitude of the lateral force and the range of impact are different, it is possible to function as a normal avalanche prevention fence during snowfall and as a high-performance rockfall protection fence during rockfall.

[When snow pressure acts]
That is, the uppermost and lowermost end rope members 20a are connected to the end struts 10a and the intermediate struts 10b.
Further, both ends of the intermediate rope member 20b are fixed to the end column 10a, and the intermediate rope member 20b is held by the intermediate column 10b via the holding release device 50 therebetween.
Each holding release device 50 only needs to be provided with a turning resistance that can counter the lateral force based on the snow pressure predicted in advance on the pivotal support portion of the turning plate 51.

  Therefore, when a lateral force due to snow pressure acts on the net surface formed by the rope material 20 and the net material 30, the rotation plate 51 of each holding release device 50 does not rotate, so the intermediate rope material 20b is the intermediate strut 10b. The lateral force acting on the intermediate rope member 20b and the end rope member 20a is transmitted to and supported by the intermediate strut 10b.

In this way, the net surface mainly composed of the rope material 20 and the net material 30 does not protrude greatly to the road side due to the lateral force due to the snow pressure, and thus it is not necessary to restore the net surface after snow removal. Become.
Further, it is not necessary to restore (maintain) the holding release device 50 every time snow is removed.

[At the time of rockfall collision]
When the falling rock collides with the net surface mainly composed of the rope member 20 and the net member 30, the intermediate rope member 20b is deformed through the net member 30 in the direction opposite to the falling stone entry side.
The intermediate rope member 20b in the vicinity of the collision is greatly deformed, and a lateral force in the road direction acts on the holding release device 50 of the intermediate column 10b.

  When the kinetic energy of the falling rock is small, the falling rock can be stopped or repelled on the net surface by resisting without rotating the rotating plate 51 of the holding release device 50.

Moreover, when the kinetic energy of falling rocks is large, the tension of the intermediate rope member 20b is large and the amount of deformation thereof is large, so that the lateral force acting on the intermediate strut 10b is large.
When the rotational torque acting on the rotating plate 51 of the holding release device 50 becomes larger than the set torque, the rotating plate 51 rotates as shown in FIG. 5, and the intermediate rope member 20b is detached from the holding release device 50 and the intermediate column 10b. The rope member 20 and the net member 30 attached to the rope member 20 can absorb a large amount of energy because the rope member 20 and the net member 30 attached to the rope member 20 can move greatly to the opposite side of the falling rock entry direction without contacting the intermediate strut 10b.
Therefore, the impact force that the impact absorbing fence finally receives is reduced.

Even when a falling rock collides with the intermediate strut 10b, the intermediate rope member 20b is detached from the holding release device 50 and is not supported by the intermediate strut 10b as described above, so that the deformation of the net surface is restrained by the intermediate strut 10b. There is no.
Therefore, there is no risk of the shock absorbing fence breaking as in the conventional case.

(8) Other Embodiments FIG. 6 shows another holding release device 50 in which the rotation resistance of the rotation plate 51 is provided by a pin.
The basic configuration of the holding release device 50 in which the rotating plate 51 of this example is pivotally supported by the mounting bracket 13 of the intermediate column 10b is the same as that of the above-described embodiment. The high friction process is not performed on the facing surface of the moving plate 51.

Instead, the resistance pin 58 is passed through the mounting bracket 13 and the rotating plate 51 at a position separated from the pivotal support portion of the rotating plate 51.
The rotating plate 51 tries to rotate due to the lateral force of the intermediate rope member 20b. When the torque of the rotating plate 51 is smaller than the shearing strength of the resistance pin 58, the shearing strength of the resistance pin 58 causes the rotation of the rotating plate 51. The rotation is restrained.

  When the torque acting on the rotating plate 51 exceeds the shear strength of the resistance pin 58, the resistance pin 58 is broken and the rotation of the rotating plate 51 is allowed, so that the intermediate rope member 20b is released. Detach from device 50.

  If the shear strength of the resistance pin 58 is set so as to be able to resist the expected snow pressure and to be sheared when it collides with a kinetic energy exceeding a predetermined level of falling rocks, the above-described implementation is performed. As in the case of, it is possible to function as a normal avalanche prevention fence during snowfall and as a high-performance rockfall protection fence during rockfall.

  In addition, in this example, the resistance pin 58 is broken with the advantage that the rotation resistance can be given to the rotation plate 51 by simply inserting the resistance pin 58 as compared with the holding release device 50 of the embodiment described above. There is an advantage that the subsequent recovery and replacement work can be easily performed.

  In addition, although the above-described holding release device 50 has been described with respect to the case where the rotation plate 51 is provided with a rotation resistance and pivotally supported, it is not broken by snow pressure other than the rotation plate 51, but exceeds the snow pressure. The intermediate rope member 20b may be held by a member that breaks when a large impact force is applied, or may be combined with a stopper having a similar function.

Moreover, although the above demonstrated the case where falling rocks and snow cover were made into an object, the effect | action mentioned above can be exhibited also for collapsing earth and sand.
Of course, it can also be applied to a guard rope for a vehicle.

Model diagram of shock absorbing fence according to the present invention Sectional view of II-II in FIG. Perspective view of holding release device with part broken away Front view of the holding release device with a part broken Model diagram of shock absorbing fence at the time of rockfall collision Side view of another holding release device Model diagram of conventional shock absorbing fence Plan view of a conventional shock absorbing fence at the time of impact

Explanation of symbols

10 ··· Post 10a ··· End strut 10b ··· Intermediate strut 13 · · · Mounting bracket 20 · · · Rope material 20a · · · End rope material 20b ··· Intermediate rope material 21... Spacing material 30... Net material 50... Holding release device 51... Rotating plate 52. .... Nut 54 ... Accommodating groove 55 ... Friction resistance surface 60 ... Shock absorber

Claims (7)

In the shock absorbing fence that is constructed by laying rope material between struts erected at intervals,
The rope material is arranged on the side opposite to the collision object entry side with respect to the support,
Attach the rope material to the support through a holding release device that releases the holding of the rope material when a certain lateral force acts on the rope material ,
The holding release device is composed of a rotation plate pivotally supported on a support column, and a rotation resistance is imparted to the pivot support portion of the rotation plate ,
Shock absorbing fence. In the shock absorbing fence that is constructed by laying rope material in multiple stages between a plurality of struts erected at intervals,
The intermediate rope member positioned between the uppermost and lowermost end rope members is fixed to the end strut, and the intermediate rope member is opposite to the collision object entry side with respect to the intermediate strut located between the end struts. Placed in
Attach the intermediate rope material to the intermediate strut via a holding release device that releases the holding of the intermediate rope material when a certain lateral force acts on the intermediate rope material ,
The holding release device is composed of a rotation plate pivotally supported on a support column, and a rotation resistance is imparted to the pivot support portion of the rotation plate ,
Shock absorbing fence.   The shock absorbing fence according to claim 2, wherein the uppermost and lowermost end rope members are attached to the intermediate struts inseparably.   4. The shock absorbing fence according to claim 1, wherein a net member is attached to the plurality of rope members.   The shock absorbing fence according to any one of claims 1 to 4, wherein a shock absorber is interposed in the rope material.   The shock absorbing fence according to any one of claims 1 to 5, wherein a spacing member is attached between the plurality of rope members.   7. The resistance release device according to claim 1, wherein the holding release device includes a rotating plate pivotally supported on a mounting bracket of a support column and a resistance pin penetrating the rotating plate and the mounting bracket. An impact-absorbing fence configured to constrain free rotation of the rotating plate by shearing strength of the rotating plate and allow rotation of the rotating plate by breaking the resistance pin.

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