JP6433783B2 - Falling object protection net and method for reinforcing the same - Google Patents

Description

  The present invention relates to a fallen object protection net provided with a pocket type protection net provided on the front side of the slope in order to protect the fallen object from the slope and a method of reinforcing the fallen object protection net.

As this type of conventional technology, for example, a pocket-type rockfall protection net for preventing a road running through a mountain from falling rocks and avalanches is known.
This rockfall protection net is hung from a plurality of struts erected on the middle of the slope, a plurality of horizontal ropes stretched across the slope width via the heads of these struts, and the top horizontal rope A vertical rope that is lowered and a wire mesh supported by the horizontal rope and the vertical rope are provided. Falling objects such as falling rocks are captured and stored in a pocket-shaped space formed between the wire mesh and the slope.

By the way, as shown in Patent Document 1, there is also known a rockfall protection net that can absorb a shock when a fallen object collides with the wire net to suppress damage to the metal net.
In this rockfall protection net, as shown in FIG. 12, shock absorbing shock absorbers 101 are incorporated at the ends of the ropes 100 used at various locations, and the ropes 100 are anchored on the slope side via the shock absorbers 101. To fix. Moreover, when a shock is applied to a rope or a wire net with falling rocks, the shock is weakened by the buffer metal fitting 101.
According to the rockfall protection net having the above-described shock absorbing capability, energy at the time of collision (hereinafter referred to as impact energy) acting on the protection net is released to the buffer fitting at the end of the rope and reduced. That is, after the impact energy generated by the collision of the falling rock is received by the protective net, the received impact energy can be released once along the rope and then weakened and absorbed by the buffer fitting at the end of the rope.

Utility Model Registration No. 3143816

However, in the rockfall protection net having the shock absorption capacity as described above,
If excessive impact is applied intensively in a short period of time, the protective mesh will be damaged shortly before the impact energy is transmitted to the shock absorber at the end of the rope, and depending on the extent of the damage, Replacement is required. In particular, in the vicinity of the center of the protective net far from the shock-absorbing metal fitting, the damage rate increases because it takes time to transmit the collision energy.

  In addition, with regard to the maintenance and management of the rockfall protection net, conventionally, regular inspection work has been carried out in order to grasp the damage state of each part. Specifically, workers regularly visited the site and checked the status of each part while climbing up and down steep slopes and cliffs. For this reason, workers and the like have been forced to perform a careful and hard work, in addition to the time and cost required for the inspection. Therefore, reduction of the burden required for maintenance is required.

  The present invention has been made in view of the above circumstances, and provides a falling object protection network that can efficiently absorb impacts while maintaining each part and that is easy to maintain and a method for reinforcing the same. is there.

In order to achieve the above object, the present invention is configured as follows.
That is, in order to protect against falling objects from the slope, the pillars standing on the slope and both ends are fixed to the sides of the slope and suspended in the slope width direction via the pillars. A falling object protective net comprising a horizontal rope and a protective net suspended from the horizontal rope below the slope,
A reinforcement rope is provided on the front side of the trough side of the protection mesh, and the reinforcement rope is configured to be able to project forward together with the protection mesh in accordance with the deformation of the protection mesh due to an impact on the protection mesh. It is characterized by restricting.

  According to the present invention, the reinforcing rope is provided on the front side of the trough side of the protective net. Further, when an impact caused by a fallen object acts on the protective net, the reinforcing rope projects forward together with the protective net along with the deformation of the protective net and absorbs the impact. In addition, the reinforcing rope that extends to the limit limit stays in front of the protective net and receives the impact of falling objects.

  As described above, when the fallen object collides with the protective net, the impact energy at the initial stage of the collision is weakened by the deformation of the protective net itself. Further, when the deformation of the protective mesh advances and an impact reaches the reinforcing rope, the remainder of the impact energy weakened in the previous stage is further weakened by both the reinforcing rope and the protective mesh. That is, in the present invention, the reinforcement net is directly reinforced using the reinforcement rope, and the energy absorption capability of the reinforcement rope is applied in the latter half of the collision, thereby avoiding excessive energy concentration on the protection net and the reinforcement rope, and the time difference. In order to absorb the impact energy efficiently.

  In addition, since the presence or absence of an impact on the protective mesh and the extent of the impact can be easily grasped from the amount of extension of the reinforcing rope, based on the confirmation of the state change of the reinforcing rope, The frequency of inspections at each part and the items to be inspected can be reviewed. As a result, the frequency and items of inspection can be made appropriate, and the efficiency of maintenance can be improved.

  Moreover, the said reinforcement rope can be provided in the front surface of the said protection net | network without slack in a normal state.

Here, the “normal state” is a state in which no falling object collides with the protective net, and the state of the reinforcing rope after the falling object collision is changed by installing the reinforcing rope without slack. Is easier to understand. Moreover, the appearance defect resulting from the slack of the reinforcing rope can be eliminated.
In the above description, “slack” refers to intentionally provided slack or intentional slack, and excludes slack due to the rigidity and weight of the reinforcing rope. That is, “providing without slack” means that reinforcing ropes are installed in a straight line as much as possible.
Moreover, in this invention, the case where a reinforcement rope is slackened and installed is not excluded irrespective of said description.

  Further, one end of a reinforcing rope provided on the front surface of the protective mesh is a fixed end, the other end is sent behind the protective mesh, and the extra length of the reinforcing rope provided for overhang is located behind the protective mesh. It is preferable to ensure it in the portion to be. However, the position of the other end is not limited to the back of the protective net. In addition, when the reinforcing rope is loosened and installed, the extra length portion of the reinforcing rope does not need to be secured separately.

Here, “the surplus length provided for the overhang” corresponds to an allowable overhang amount, and the reinforcing rope is provided so as to be able to project to the front of the protective net within the range of the extra length.
Moreover, in this structure, since the surplus length of the reinforcing rope is ensured behind the protective net, the slack of the reinforcing rope is not exposed to the outside.

  In addition, a holding member that slidably holds the reinforcing rope is provided, and the reinforcing rope is sent to the back of the protective net via the holding member, and is located on the rear end side (the protective net behind) of the holding member. A stopper is provided on the rope so as to abut against the holding member and to limit the amount of the reinforcing rope that protrudes.

  In this configuration, the amount of extension of the reinforcing rope is limited by the combination of the holding member and the stopper. That is, when the reinforcement rope is projected forward of the protective net by the collision of the falling object, the reinforcement rope can be extended until the stopper provided on the rear end side of the reinforcement rope comes into contact with the holding member.

Further, both ends of the reinforcing rope provided on the front surface of the protective net, that is, both ends are fixed ends, and excluding the both ends, at least one section is sent to the back of the protective net,
The extra length of the reinforcing rope provided for the overhang may be secured by providing a slack in a section sent behind the protective net.

  In this configuration, at least one section excluding both ends of the reinforcing rope is sent to the back of the protective net, and this section is slackened behind the protective net to secure an extra length. Further, since both ends of the reinforcing rope are fixed together, the reinforcing rope can be extended until the slack behind the protective net is eliminated. That is, in this configuration, it is possible to limit the amount of overhang without using a stopper.

  Further, the limit of the overhang amount can be set so that the reinforcing rope can be broken prior to the plastic deformation of the protective net when an impact accompanied by the breaking of the reinforcing rope is applied.

  That is, in the case of an impact accompanied by the breakage of the reinforcing rope, by setting the overhang amount so as to satisfy the above condition, it is possible to draw all the shock absorbing ability of the reinforcing rope prior to the plastic deformation of the protective net.

  The effective length of the reinforcing rope can be set in the range of 102% to 110%, preferably in the range of 102% to 106%, based on the installation span of the reinforcing rope.

  Here, the “installation span” is defined by the shortest distance of the section where the reinforcement rope should be installed. On the other hand, the “effective length” corresponds to the distance between the fixed ends of the reinforcing ropes that can be overhanged. For example, when the effective length is converted to the actual length for an installation span of 4 m, the effective length of 102% is the installation span of 4 m + 2. % Increase to 4,08m. Further, when the effective length is 110%, the installation span is increased by 4 m + 10% to 4,4 m.

  In addition, a plurality of the reinforcing ropes can be provided on the front surface of the protective net, and the limit of the amount of protrusion of each reinforcing rope can be made different for each reinforcing rope.

  That is, in this configuration, a plurality of reinforcing ropes having different effective lengths are installed on the front surface of the protective mesh, so that even if the effective length reinforcing rope (short) breaks due to an impact, the remaining effective length reinforcing rope (long) Can be configured to continue to reinforce the protective mesh.

  In addition, the reinforcement structure of the fall object protection net | network comprised by the above-mentioned reinforcement rope can be effectively added not only to the existing fall object protection net | network but to an existing fall object protection net | network. .

Further, the reinforcing method according to the present invention is to protect the fallen object from the slope, with the pillars standing on the slope and both ends fixed to the sides of the slope, and via the pillars. A falling rope protection network comprising a horizontal rope suspended in the slope width direction and a protection net suspended from the horizontal rope below the slope,
A step of providing a reinforcing rope on the front surface of the protective mesh and disposing the reinforcing rope so as to extend forward of the protective mesh when an impact occurs on the protective mesh; and the reinforcing rope stays in front of the protective mesh. And a step of installing so that the amount of overhang is limited.

  As described above, the reinforcing structure and the reinforcing method according to the falling object protection net of the present invention can be applied regardless of whether the falling rock protection net is newly installed or existing. In addition, about a concrete reinforcement method, it applies to each above-mentioned structure. Further, various items described in the means for solving the problem can be combined without departing from the problem of the invention.

  As described above, according to the present invention, it is possible to provide a falling object protection net that can efficiently absorb an impact while maintaining each part and that is easy to maintain and a method for reinforcing the same.

FIG. 3 is a perspective view of a falling object protection net shown in the first embodiment. The schematic block diagram of a reinforcement rope. The schematic diagram which shows a mode that a reinforcement rope protrudes. The side view which shows the falling object protection net | network of the initial stage of a collision. The side view which shows the falling object protection net | network in the latter half of a collision. FIG. 5 is a front view of a falling object protection net shown in a second embodiment. The schematic diagram which shows a mode that a reinforcement rope protrudes. FIG. 6 is a schematic configuration diagram of a reinforcing rope shown in a third embodiment. FIG. 6 is a front view of a falling object protection net shown in a fourth embodiment. FIG. 10 is a front view of a falling object protection net shown in a fifth embodiment. FIG. 10 is a front view of a falling object protection net shown in a sixth embodiment. The perspective view which shows the conventional improved pocket type rock fall protection net.

The fallen object protection network 1 according to the present invention holds a plurality of support columns 2 standing at intervals in the width direction of the slope S, and each of these support columns 2 at a desired angle with respect to the slope S. A suspension rope 3 is provided. Further, a holding rope 7 (lowermost horizontal rope) stretched in the width direction of the slope below the slope S, and a plurality of rows of vertical ropes 5 suspended from the heads of the columns 2 to the holding rope 7. And a vertical auxiliary rope 6 disposed between the vertical ropes 5 and 5. In addition, there are provided a plurality of upper and lower horizontal ropes 4 which are provided so as to intersect with the vertical rope 5 and the auxiliary auxiliary rope 6 and whose both ends are fixed to the anchors 11 on the side of the slope.
Of the plurality of upper and lower horizontal ropes 4, the uppermost horizontal rope 4 a is suspended in the slope width direction via the heads of the columns 2, and is protected from the uppermost horizontal rope 4 to the holding rope 7. A net 8 is suspended.

  The front side of the slope from the uppermost horizontal rope 4 a to the holding rope 7 is partitioned in a lattice pattern by the horizontal rope 4 and the vertical rope 5 described above, and the protective net 8 is partitioned by the horizontal rope 4 and the vertical rope 5. The contacted area is crossed from the outside (slope front side). And the pocket-shaped accommodating part 9 is formed between this protective net | network 8 and a slope.

  In addition, the protection net | network 8 uses metal fittings, such as a cross clip and a coupling coil, in each contact with each rope (horizontal rope, vertical rope, vertical auxiliary rope, and holding rope) 4,5,6,7, and each rope 4 , 5, 6 and 7 are fixed. Further, the intersections of the ropes 4, 5, 6, and 7 are also fixed together by a cross clip, a coupling coil, or the like, and the ropes 4, 5, 6, 7 and the protective net 8 are rigid as an integral structure. Can be obtained.

In addition, in the falling object protection net 1 of the present invention, in addition to the various ropes 4, 5, 6, and 7 described above, a rope for reinforcing the protection net (hereinafter referred to as a reinforcement rope 10) is provided on the front upper portion of the protection net 8. Is provided.
Hereinafter, a fallen object protection net reinforcement structure using the reinforcement rope 10 according to the present invention and a reinforcement method thereof will be described.

[Embodiment 1]
In the first embodiment, among the regions partitioned in a lattice pattern by the vertical rope 5 and the vertical auxiliary rope 6, each of the front surfaces (front side) of each of the three sections P1 having a two-row width arranged in the uppermost row thereof, The reinforcing rope 10 is arranged in a brace shape. Further, the reinforcement rope 10 is provided with an extra length as will be described later, and the reinforcement rope 10 is provided so as to be able to project forward in the range of the extra length.
The uppermost section P1 corresponds to an entrance into the falling object protection network 1 and has the highest collision rate with falling objects falling along the slope S. For this reason, in the present embodiment, the uppermost section P1 is reinforced by the reinforcing rope 10 to avoid local damage of the protective net 8 and to maintain the entire fallen object protective net.

Specifically, as shown in FIG. 1, the reinforcing ropes 10, 10 are provided so as to intersect each other along the two diagonal lines per section.
Further, at the central intersection of the reinforcing ropes 10 and 10 on the front surface of the protective net, the reinforcing ropes 10 and 10 are connected to each other.
In this way, the reinforcing ropes 10 and 10 are crossed at the center of the section, thereby increasing the energy absorption amount of the section center portion having a high damage rate.

  Further, the distal end portion (the lower end side in FIG. 1) of each reinforcing rope 10 is locked to the intersection (hereinafter referred to as the lower edge side corner) of the horizontal rope 4 and the vertical rope 5 at the lower edge of the section. It is fixed by fixing means such as a winding grip. In addition, the rear end portion (upper end side in FIGS. 1 and 2) of each reinforcing rope 10 is an intersection (hereinafter referred to as an upper edge side corner) of the horizontal rope 4 and the vertical rope 5 at the upper edge of the section or in the vicinity of the intersection. The reinforcing rope 10 is positioned in front of the protective net 8 without slack in its normal state via the shackles 12 respectively provided in the back of the protective net 8.

  Further, as shown in FIG. 2, the rear end portion (rear end side) of the reinforcing rope 10 extending behind the protective net 8 is made of a metal that restricts the amount of protrusion of the reinforcing rope 10 by contact with the shackle 12 (for example, , Made of aluminum) (hereinafter referred to as stopper 13) is crimped and fixed. Further, the length Y from the stopper 13 to the shackle 12 is determined in consideration of the overhang amount of the reinforcing rope 10. That is, the extra length provided for the overhang of the reinforcing rope 10 is secured from the stopper 13 to the shackle 12.

The effective length of the reinforcing rope 10, that is, the actual length from the fixed end of the reinforcing rope 10 to the stopper 13 is in the range of 102% to 110%, preferably 102%, based on the installation span of the reinforcing rope 10 as 100%. It is set in a range of ˜106%. By setting the effective length in advance in this way, the reinforcing rope 10 can be accurately retained at a fixed position in front of the protective net when a falling object collides. .
When the installation span is described in view of FIG. 1, the length of the diagonal line in the section P1 corresponds to the installation span in the present invention.

In addition, the effective length setting method, in other words, the extra length setting method of the reinforcing rope is set based on various preliminary experiments conducted in consideration of the expansion / contraction rate and load resistance of the protective net 8, the longitudinal elastic modulus of the reinforcing rope 10, and the like. Has been.
Specifically, the scale of falling rocks at each installation site of the fallen object protection net 1 is predicted and assumed, and preferably a value that can prevent the breakage of the protection net 8 within the assumed range, and the reinforcing rope 10 The effective length is selected so as to satisfy both of the values that can be broken prior to the plastic deformation of the protective net 8. Further, along with the selection of the effective length, the extra length of the reinforcing rope 10 is naturally determined.

  Next, the impact absorbing effect of the reinforcing rope 10 will be described with reference to FIGS. FIG. 3 is a schematic diagram showing a state in which the reinforcing rope protrudes, and FIG. 3A shows the reinforcing rope in a normal state (standby state). FIG. 3B shows a reinforcing rope immediately after the start of overhang. FIG. 3C shows the reinforcing rope in a completely overhang state.

  First, as shown in FIG. 4, when the falling rock D is generated above the slope, the falling rock D enters the falling object protection net 1 while jumping up and down the slope S. At this time, the reinforcing rope 10 is still in a standby state and is disposed without slack on the front surface of the protective net (see FIG. 3A). Further, most of the falling rocks enter the uppermost section P1 and collide with the protective net 8 in the area where the protective net 8 is laid. Further, as shown in FIG. 5, the protective net 8 absorbs the impact energy of the falling rock D while being bent outward due to the collision with the falling rock D.

  Further, at the same time that the protective mesh 8 starts to bend, the reinforcing rope 10 disposed on the front surface of the protective mesh 8 is also pushed by the protective mesh 8 and protrudes forward of the protective mesh (see FIG. 3B). Further, the stopper 13 at the rear end portion of the reinforcing rope hits the shackle 12 with the extension of the reinforcing rope 10, and thereafter the extension of the reinforcing rope 10 is restricted and prevented by the stopper 13 (see FIG. 3C). . Therefore, the reinforcing rope 10 stays in front of the protective net and prepares for a subsequent impact.

  Subsequently, when an impact reaches the reinforcing rope 10, the remaining impact energy is absorbed by further deforming the protective net 8 and extending or tearing (cutting) the reinforcing rope 10. That is, the impact energy in the latter half of the collision is weakened by both the protective net 8 and the reinforcing rope 10.

  As described above, the effective length of the reinforcing rope 10 has both a value capable of preventing the protective net 8 from breaking against an assumed rock fall and a value capable of breaking the reinforcing rope 10 prior to plastic deformation of the protective net 8. It is set to meet. Therefore, in the case of falling rocks as expected, damage to the protective net 8 can be avoided even if the impact is accompanied by the breakage of the reinforcing rope 10. Moreover, the fallen object protection net | network 1 can be restored to the original state only by replacement | exchange of the reinforcement rope 10. FIG.

  Thus, according to the present reinforcing structure, the reinforcing net 10 is directly reinforced by providing the reinforcing rope 10 on the front surface of the protective net 8. Further, since the reinforcement rope 10 is provided with a surplus length so that the reinforcement rope 10 can be projected to the front of the protective net, the shock absorbing ability of the reinforcement rope can be concentrated and act in the latter half of the collision of the fallen object. That is, the energy at the initial stage of the collision is absorbed to some extent by the protective net 8 and weakened, and the energy at the latter stage of the collision is absorbed by both the reinforcing rope and the protective net. Therefore, the impact is not excessively concentrated on the protective net 8 and the reinforcing rope 10, and the impact energy is efficiently absorbed while being distributed in the process of acting on the protective net 8 and the reinforcing rope 10.

  Moreover, since the presence or absence and the extent of the impact on the protective net 8 can be generally grasped from the amount of protrusion of the reinforcing rope 10 after receiving the fallen object, the state of the reinforcing rope 10 is confirmed and analyzed, so that the falling object protective net 1 The frequency of inspection in each part can be determined, and unnecessary inspection items can be omitted. That is, if the slackness of the reinforcing rope 10 is confirmed using binoculars or the like from the cliff or the nearest road, it can be easily determined whether or not inspection of each part in the site is necessary.

[Test Example 1]
The preliminary experiment 1 related to the selection of the effective length is shown below.
1. Outline and purpose of the test To understand the relationship between the effective length of the reinforcement rope and the reinforcement effect of this reinforcement structure with the reinforcement rope in front of the protective net.

2. Test body and test content A Structure of test body A rectangular base (frame) was formed with a vertical rope and a horizontal rope of φ16 mm, and this base was regarded as one section of the uppermost stage shown in this embodiment, and an experiment was conducted. . That is, a protective net was applied to a frame made up of vertical ropes and horizontal ropes, and reinforcement ropes were installed in a crossing state diagonally from the outside.
B frame size length 5m × width 3m
C Protection net Wire diameter 4.0mm
D Vertical rope / horizontal rope specifications φ16 General-purpose twisted rope of steel wire specified in JIS G 3525 E Reinforcement rope 10 specification φ14 General-purpose twisted rope of steel wire specified in JIS G 3525 In this test, on each diagonal line Two reinforcing ropes 10 were installed one by one.
F Handling of effective length In this test, in order to grasp the optimum value of the effective length accurately, the effective length was selected by using the deformation rate of the reinforcing rope having a correlation with the effective length.
The “deformation rate” is an index that indicates how much the central portion of the protective net is deformed from a reference line that horizontally connects both ends of the reinforcing rope as a reference. In this test, the deformation rate standard was determined with the possible amount of deformation of the protective net as 100%. Specifically, the deformation amount when a reinforcement rope having an effective length of 126% (actual length = installation span size × 26% increase) is used as a reference, and the deformation amount of the protective net at this time is determined as a deformation rate of 100%. It was. In addition, since the amount of change per unit% (the fluctuation width of the measured value) is obtained larger than the amount of change in the effective length, the “deformation rate” can be obtained by using this deformation rate in combination with the effective length and the reinforcing effect. Can be accurately verified.
G Falling object The spherical concrete block 11KN which applies a dynamic load to the protective net was lifted by a crane and dropped from a predetermined height.
3. Test results

A Deformation rate 30-50% (effective length 102.3-106.4%)
In the trials in this range, the protection net and the vertical rope supporting the protection net both maintained soundness and the reinforcement effect was clearly obtained.
B Deformation rate 60% (effective length 109.2%)
In this trial, the reinforcement effect was thin, and the protective net was damaged, and the weight could not be stored.

4). Evaluation From the above experimental results, the effectiveness was particularly confirmed with a reinforcing rope having a deformation ratio of 30 to 50% and an effective length of 102 to 106%.

[Test Example 2]
Subsequently, preliminary experiment 2 relating to selection of the effective length is shown below.
1. Outline and purpose of the test In this test, the reinforcement effect of two types of long and short reinforced ropes with different effective lengths, one on the diagonal of the same section and a total of four on the diagonal. Verified.

2. Test body and test content A Structure of test body A rectangular base (frame) was formed with a vertical rope and a horizontal rope of φ16 mm, and this base was regarded as one section of the uppermost stage shown in this embodiment, and an experiment was conducted. . That is, a protective net was applied to a frame made up of vertical ropes and horizontal ropes, and reinforcement ropes were installed in a crossing state diagonally from the outside.
B frame size length 5m × width 3m
C Protection net Wire diameter 4.0mm
D Vertical rope / Horizontal rope specification φ16 General-purpose twisted rope of steel wire specified in JIS G 3525 E Reinforcement rope specification Reinforcement rope (long) φ16 General-purpose twisted rope of steel wire specified in JIS G 3525 × 2 Reinforcement rope ( Short) φ14 General-purpose twisted rope of steel wire specified in JIS G 3525 × 2 pieces F Effective length In the same manner as in Test Example 1, the effective length was selected using the deformation rate.
G Falling object The spherical concrete block 11KN that applies a dynamic load to the protective net is lifted by a crane and dropped from a predetermined height.
3. Test results

A Test No1
Reinforcement rope (long) Deformation rate 40% (effective length 104.1%)
Reinforcement rope (short) Deformation rate 30% (effective length 102.3%)
According to this trial, both the reinforcing rope (long) and the reinforcing rope (short) were broken, so that the strength of both the reinforcing ropes and the energy absorption amount are considered to be insufficient.
B Test No2-No4
Reinforcement rope (long) Deformation rate 50-70% (effective length 106.4-112.6%)
Reinforcement rope (short) Deformation rate 40-60% (effective length 104.1-109.2%)
In this trial, the soundness of the reinforcing rope (long) was maintained. The reinforcing rope (short) broke with the absorption of impact energy. That is, the soundness of the reinforcing rope (long) functioning as a spare reinforcing rope was secured while achieving a high impact absorption rate with the effective length of the reinforcing rope (short).
C Test No5
Reinforcement rope (long) Deformation rate 80% (effective length 116.4%)
Reinforcement rope (short) Deformation rate 70% (effective length 112.6%)
According to this trial, both the reinforcing rope (long) and the reinforcing rope (short) were broken, and the vertical rope supporting the wire mesh was also damaged, so there was insufficient strength of both reinforcing ropes and insufficient energy absorption. Conceivable.
4). Evaluation From the above experimental results, test no. Good results were obtained in trials 2-4.
That is, the effectiveness of the present reinforcing structure was shown by a combination of reinforcing ropes having an effective length of about 105% to 110% (40 to 70% in terms of deformation rate).

  In addition, according to a further experiment by the present inventor, the same tendency was observed even when the specifications of the protection network were changed. That is, it can be said that the reinforcing effect exhibited by the reinforcing rope is uniquely found depending on the effective length of the reinforcing rope without depending on the specifications of the protective net.

[Embodiment 2]
Next, the second embodiment will be described.
The falling object protection net described in the second embodiment is different from the first embodiment in the structure of the reinforcing rope. Specifically, in the second embodiment, the reinforcing ropes provided on the respective diagonal lines are constituted by one long reinforcing rope 15. There is no stopper for limiting the amount of overhang, and both ends of the reinforcing rope 15 are both fixed at the intersection of the vertical rope and the horizontal rope.
In addition, since the structure other than the above of the reinforcing rope 15 conforms to the first embodiment, the same portions will be described with the same reference numerals.

Hereinafter, the feeding of the reinforcing rope 15 to the back of the protective net 8 will be described with reference to FIG.
First, the end portions of the reinforcing ropes 15 are inserted from behind the shackles 12 and 12 respectively provided at the upper edge corners of the section P1. Further, the reinforcing rope 15 drawn out to the front surface of the protective net 8 through the shackle 12 is arranged on the diagonal of the section P1 so as to intersect at the center of the reinforcing section P1. Moreover, each end part of the reinforcing rope 15 arrange | positioned on a diagonal line is each fixed to the nearest lower edge corner | angular part in the division. The reinforcing rope 15 may be sent behind the protective net 8 from above as described above, or vice versa.

  Further, an extra length that allows the reinforcement rope 15 to be overhanged is secured behind the protective net 8. Specifically, considering the distance between the shackles 12 and 12 and the effective length of the reinforcing rope 15, an extra length is secured in the reinforcing rope 15, and a slack corresponding to this extra length is provided between the shackles to secure the extra length. To do.

That is, in the second embodiment, both ends of the reinforcing rope 15 disposed on the front surface of the protective net 8 and multiple ends, that is, both ends are fixed ends, and one section (intermediate portion) excluding both ends. Is sent to the back of the protective net 8 and slackened, and the slackening secures the extra length of the reinforcing rope 15.
In addition, since the reinforcement rope 15 used in this Embodiment 2 has substantially the length of two reinforcement ropes and the impact absorption capability, when selecting the effective length, the effective per reinforcement rope 15 is taken into consideration. Set the length and extra length.
In addition, the reinforcing rope 15 is arranged on the front surface of the protective net 8 without slacking in the normal state as in the first embodiment by loosening the portion corresponding to the extra length of the reinforcing rope 15 behind the protective net 8 in this way.

Next, how the reinforcing rope 15 projects will be described with reference to the schematic diagram of FIG.
7A-1 is a front view showing a reinforcing rope in a normal state (standby state), and FIG. 7A-2 is a side view showing the reinforcing rope in a normal state (standby state). FIG. 7B-1 is a front view showing the reinforcement rope immediately after the start of overhanging, and FIG. 7B-2 is a side view showing the reinforcement rope immediately after the start of overhanging. FIG. 7 (c-1) is a front view showing the reinforcing rope in a completely overhanging state, and FIG. 7 (c-2) is a side view showing the reinforcing rope in a completely overhanging state.

  In the state where rockfall has not yet occurred, as shown in FIG. 7A, the reinforcing rope 15 is disposed without slack on the front surface of the protective net. In addition, rock fall occurs, and the protection net 8 starts to bend forward due to the collision with the rock fall, and at the same time, the reinforcement rope 15 is pushed by the protection net 8 and projects forward (see FIG. 7B). In addition, when tension is applied between the shackles as the reinforcement rope 15 extends, the extension of the reinforcement rope 15 is restricted and prevented thereafter.

Thus, in Embodiment 2, since both ends of the reinforcement rope 15 are fixed together, the reinforcement rope 15 can be projected until the slack behind the protective net is eliminated. That is, by adopting the reinforcing rope 15 of the second embodiment, it is possible to limit the amount of overhang without using a stopper.
The arrangement of the reinforcing rope may be reversed upside down.

[Embodiment 3]
Subsequently, Embodiment 3 will be described.
In the third embodiment, based on the configuration of the second embodiment and the test example 2 described above, the reinforcing rope 15 is configured with two types of long and short reinforcing ropes 15a and 15b as shown in FIG. These reinforcing ropes 15a and 15b are assembled one by one on the front surface of the protective net.

In other words, by providing two long and short reinforcing ropes 15a and 15b having different effective lengths, if the impact energy cannot be absorbed by the reinforcing rope (short) 15b, the remaining impact energy can be reduced with the remaining effective rope 15a. Absorb.
The reinforcing rope (long) 15a is positioned as a spare reinforcing rope, and when the reinforcing rope (short) 15b breaks, the protection net 8 is prevented from being newly damaged before the replacement.

  Thus, in this Embodiment 3, the protection net | network 8 is reinforced using several reinforcement ropes 15a and 15b from which effective length differs.

[Embodiment 4]
In the fourth embodiment, based on the configuration of the first embodiment, among the regions partitioned in a lattice shape, the reinforcing rope 10 is installed with all the partitions arranged in the uppermost stage as one partition P2.

  Specifically, as shown in FIG. 9, a reinforcing rope 10 is installed in parallel with the lateral ropes 4a and 4b at the center between the uppermost lateral rope 4a and the next lateral rope 4b. Moreover, the setting position of the extra length with respect to the reinforcement rope 10, and the attachment method of the stopper 12 can be illustrated variously. For example, as shown in FIG. 9, an extra length is secured at both ends of the reinforcing rope 10, and stoppers are provided at both ends of the reinforcing rope 10 corresponding to the extra length. Further, one end of the reinforcing rope 10 may be a fixed end, and an extra length and a stopper may be provided on the other end side.

[Embodiment 5]
In the fifth embodiment shown in FIG. 10, similarly to the fourth embodiment, the reinforcing rope 10 is installed with all sections arranged in the uppermost row as one section P2. Further, the difference from the fourth embodiment is that the reinforcing rope 10 is not provided in parallel to the horizontal rope 4 but is provided on the diagonal line of the section P2.

[Embodiment 6]
In the sixth embodiment shown in FIG. 11, the reinforcement ropes 10 are individually installed in the entire section P of the protection net 8. Further, similarly to the first embodiment described above, the reinforcing ropes 10 are provided on the two diagonal lines of each section P, respectively. For this reason, since the reinforcement rope 10 can be densely arranged in the entire laying region of the protective net 8, further improvement in the energy absorption rate can be achieved.

Thus, the reinforcing structure according to the present invention can be exemplified in various embodiments.
In addition, the above-described reinforcing structure of the falling object protection net 1 can be applied not only to a new installation, but also to an already installed falling object protection net. Moreover, the fallen object protection net | network 1 of this invention is useful not only as a fallen rock but as a protective measure against a landslide, a rock fall, and an avalanche.

DESCRIPTION OF SYMBOLS 1 Falling object protection network 2 Support | pillar 3 Hanging rope 4 Horizontal rope 4a Top horizontal rope 4b Second horizontal rope 5 Vertical rope 6 Vertical auxiliary rope 7 Pressing rope (bottom horizontal rope)
8 Protective net 9 Falling rock storage 10 Reinforcement rope 11 Anchor body 12 Shackle 13 Stopper 15 Reinforcement rope 15a Reinforcement rope (long)
15b Reinforcement rope (short)
P Section P1 Each section on the top P2 All sections on the top D D Fallen object S Slope

Claims (9)

In order to protect against fallen objects from the slope, the pillars erected on the slope and the lateral ropes whose both ends are fixed to the side of the slope and suspended in the width direction of the slope via the pillar And a fallen object protection net provided with a protection net suspended from the side rope below the slope,
A reinforcement rope is provided on the front side of the trough side of the protection net, and the reinforcement rope is configured to be slidable forward together with the protection net along with the deformation of the protection net due to an impact on the protection net. A falling object protection net characterized by limiting the amount of overhang.   The fallen object protection net according to claim 1, wherein the reinforcing rope is provided on the front surface of the protection net without slack in a normal state.   One end of a reinforcing rope provided on the front surface of the protective net is a fixed end, the other end is sent behind the protective net, and the extra length of the reinforcing rope used for overhang is a portion located behind the protective net The fallen object protection net according to claim 1, wherein the fallen object protection net is secured. A holding member for slidably holding the reinforcing rope is provided, and the reinforcing rope is sent to the back of the protective net via the holding member,
4. The stopper according to claim 1, wherein a stopper is provided on the rope on a rear end side of the holding member so as to abut against the holding member and limit a protruding amount of the reinforcing rope. 5. Falling object protection net. Both the one end and the other end of the reinforcing rope provided on the front surface of the protective mesh, that is, both ends are fixed ends, and at least one section excluding the both ends is sent to the back of the protective mesh,
The fallen object protection net according to any one of claims 1 to 3, wherein an extra length of the reinforcing rope provided for the overhang is secured by providing a slack in a section sent behind the protection net. .   The limit of the amount of overhang is set so that the reinforcement rope can be broken prior to plastic deformation of the protective net when an impact accompanied by the breakage of the reinforcement rope is applied. To a falling object protection net according to any one of 5 to 5. 6. The drop according to claim 1, wherein the effective length of the reinforcing rope is set in a range of 102.3% to 106.4% based on an installation span of the reinforcing rope. Object protection net. The reinforcement net according to any one of claims 1 to 7, wherein a plurality of the reinforcing ropes having the same arrangement are provided on the front surface of the protective net, and a restriction on the amount of overhang of each reinforcing rope is made different for each reinforcing rope. Falling object protection net described in 1. In order to protect against fallen objects from the slope, the pillars erected on the slope and the lateral ropes whose both ends are fixed to the side of the slope and suspended in the width direction of the slope via the pillar And a method of reinforcing a fallen object protection net comprising a protection net suspended from the side rope below the slope,
A step of providing a reinforcing rope on the front surface of the protective mesh, and arranging the reinforcing rope so as to be slidable and slidable forward to the front of the protective mesh when an impact occurs on the protective mesh; and And a method of reinforcing the falling object protection net, characterized in that it includes a step of setting the projecting amount to be limited in order to stay in front.

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