JP6639774B2 - Falling object protection net and its reinforcement method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a fallen object protection net including a pocket type protection net provided on the front side of a slope to protect a fallen object from the slope, and a reinforcing method thereof.

As this type of conventional technology, for example, a pocket-type rockfall protection net for preventing a road running in a mountain from falling rocks or an avalanche is known.
As shown in FIG. 9, the rock fall protection net includes a plurality of pillars 200 erected on the middle of the slope and a plurality of horizontal ropes stretched in the width direction of the slope via the heads of the pillars 200. 400 (400a, 400b), a vertical rope 500 suspended from the uppermost horizontal rope 400a, and a wire mesh 800 supported by the horizontal ropes 400a, 400b and the vertical rope 500. Also, falling objects such as falling rocks are captured and accommodated between the wire mesh 800 and the slope S.

Further, as an improved example of the rock fall protection net described above, a rock fall protection net shown in Patent Document 1 is also known.
In this rock fall protection net, as shown in FIG. 10, a shock absorbing metal fitting 101 is incorporated at an end of a rope 100 used at each position, and the rope 100 is connected to the anchor body 102 on the side of the slope through the shock absorbing metal fitting 101. Fixed to. Further, when an impact is applied to the rope or the wire netting due to the falling rock, the impact is reduced by the buffer metal fitting 101. That is, the incorporation of the buffer fitting 101 prevents the rope and the wire net from being damaged.

Japanese Utility Model Registration No. 3143816

  By the way, according to the rock fall protection net having the above-mentioned shock absorption ability, the impact energy acting on the protection net is released to the buffer metal and weakened. That is, after the impact energy is received by the protective net, the received impact energy is temporarily released to the end of the rope, and is absorbed by the buffer metal fitting on the end of the rope.

  For this reason, if an excessive impact is applied in a short time, the protective net will be damaged soon after transmitting the impact energy to the shock absorber, and depending on the degree of the disaster, the protective net will need to be totally replaced. In particular, in the vicinity of the center of the protective net far from the buffer metal fittings, it takes time to transmit the collision energy, so that the damage rate is high.

  The present invention has been made in view of the above circumstances, and provides a fall protection net capable of efficiently absorbing impact energy in a short time and a method for reinforcing the fall protection net.

In order to achieve the above object, the present invention is configured as follows.
That is, in order to protect a falling object from the slope, a pillar erected on the slope and a horizontal rope fixed at both ends to the side of the slope and suspended in the width direction of the slope via the pillar. And a protection net suspended from the horizontal rope below the slope, a fallen object protection net comprising:
It is characterized in that a reinforcing rope for reinforcing the protective net is bent and provided outside the protective net.

  In the present invention configured as described above, the reinforcing rope is bent and provided outside the protective net. Thus, the initial impact energy is weakened by the deformation of the protective net without reaching the reinforcing rope. Further, as the protective net is further deformed and the protective rope is further applied to the protective rope, the remaining impact energy is reduced by both the protective rope and the protective net.

  In other words, the provision of the reinforcing rope outside the protective net eliminates the time loss at the time of energy absorption and avoids the damage of the protective net, and furthermore, the reinforcing rope is bent against the protective net, thereby providing the protective net. The shock absorption rate is increased while making use of the shock absorption capacity possessed by.

Also, a vertical rope is provided from the horizontal rope to a lower slope,
The reinforcing rope may be provided so as to pass through a region defined by the horizontal rope and the vertical rope, particularly, a central upper portion of the region.

  In this configuration, the reinforcing rope is provided so as to pass through a region partitioned by the horizontal ropes and the vertical ropes, particularly, above the center of the region. In other words, by providing the reinforcing rope so as to pass through the central region or above the center of the section which is easily broken, the damage rate of the protective net provided in the section is reduced.

  Further, the reinforcement rope may be provided on a diagonal line of a region defined by the horizontal rope and the vertical rope.

  In this configuration, since the reinforcing rope is provided on the diagonal line, the installation span of the reinforcing rope is the longest in this section, and a large amount of energy absorption of the reinforcing rope can be secured.

Further, the protective net is fixed to the horizontal rope and the vertical rope,
The reinforcing rope may be connected to a fixed portion between each of the ropes and the protective net.

  In this configuration, the protective net is fixed to the horizontal rope and the vertical rope. The reinforcing rope is connected to a fixed portion between the protective net and each of the ropes (the horizontal rope and the vertical rope). For this reason, the impact energy acting on the reinforcing rope does not directly act on the protective net, but is received with the fixed portion between the protective net and each rope as a fulcrum.

  Further, it is preferable that the degree of bending of the reinforcing rope is set so that breakage of the protective net can be prevented.

  In this configuration, when setting the degree of bending of the reinforcing rope, a value that can prevent breakage of the protective net is adopted. That is, the reinforcing rope is actuated before the protective net is damaged, and the shock absorbing force of the reinforcing rope avoids damage to the protective net.

  Further, the degree of bending of the reinforcing rope may be set so that the reinforcing rope can be broken prior to the plastic deformation of the protective net.

  In this configuration, when the degree of bending of the reinforcing rope is set, the degree of bending is set so that the reinforcing rope is broken prior to the plastic deformation of the protective net. In other words, by actively breaking the reinforcing rope, all the energy absorption of the reinforcing rope is drawn out, and the maintenance of the protection net is aimed at.

  Further, the bending degree of the reinforcing rope may be set in a range of 102 to 110% as a bending ratio with respect to the installation span.

Here, the installation span corresponds to the distance of one section where the reinforcing rope should be bent and installed, and the bending rate is defined by the actual length of the reinforcing rope with respect to the length of the section. That is, for example, the bending rate of the reinforcing rope having a length 1.5 times that of the section is 150%. In addition, the bending rate of the reinforcing rope having a double length can be said to be 200%.
Further, when the bending rate of the reinforcing rope is set in such a range, the impact energy can be efficiently absorbed by both the protective net and the reinforcing rope while keeping the protection net within a range where breakage of the protective net can be prevented.

  In addition, a plurality of types of long and short reinforcing ropes may be provided at locations where the reinforcing ropes are to be installed, and the bending degree of the long reinforcing rope may be different from that of the short reinforcing rope.

  In this configuration, since the bending rates of the respective reinforcing ropes are made different, the absorption timing of the impact energy can be shifted. Further, even if one of the plurality of reinforcing ropes is damaged, the remaining reinforcing rope can prevent damage to the protective net.

  The reinforcing structure constituted by the above-described reinforcing rope is useful not only for a newly installed fallen object protection net, but also for an existing fallen object protection net. That is, the reinforcing structure and the reinforcing method according to the fallen object protection net of the present invention can be applied regardless of whether they are new or existing.

Further, in the present invention, in order to protect falling objects from the slope, a pillar is erected on the slope, both ends of the horizontal rope are fixed to the side of the slope, and in the width direction of the slope via the pillar. A method for reinforcing a fallen object protection net by suspending the protection net from the horizontal rope below the slope,
It is characterized in that a reinforcing rope for reinforcing the protective net is bent and provided outside the protective net.

That is, this is a reinforcement method in which the reinforcement structure according to the present invention is applied to an existing or newly installed fallen object protection net. In addition, a specific reinforcing method conforms to each of the above-described configurations.
Further, various items described in the means for solving the present problem can be combined without departing from the object of the present invention.

  As described above, according to the present invention, it is possible to provide a fallen object protection net capable of efficiently absorbing impact energy in a short time and a reinforcing method thereof.

FIG. 1 is an overall perspective view of a fallen object protection net shown in Embodiment 1. The top view of the reinforcement rope provided in a reinforcement part. FIG. 3 is a schematic diagram showing how a reinforcing rope bends with respect to a protective net. FIG. 4 is a side view showing a state in which a falling object collides with the protection net in the falling object protection net according to the first embodiment. FIG. 3 is a side view showing a state in which a reinforcing rope is extended in the fallen object protection net according to the first embodiment. The front view of the fallen object protection net of Embodiment 2. The front view of the fallen object protection net of Embodiment 3. FIG. 13 is a front view of the fallen object protection net according to the fourth embodiment. The perspective view which shows the conventional pocket type rock fall protection net. The perspective view which shows the improvement example of the conventional pocket-type rock fall protection net.

As shown in FIG. 1, a fallen object protection net 1 according to the present invention includes a plurality of columns 2 erected at intervals in the width direction of a slope S, and A hanging rope 3 erected at an angle, a holding rope 7 (the lowest horizontal rope) stretched under the slope S in the width direction of the slope, and a hanging rope 7 hanging from the head of each column 2 to the holding rope 7. A plurality of rows of vertical ropes 5, a vertical auxiliary rope 6 disposed between the vertical ropes 5, 5, an anchor 11 provided to intersect with the vertical rope 5 and the vertical auxiliary rope 6, and both ends of which are on the slope side. And a plurality of upper and lower horizontal ropes 4 fixed to
The uppermost horizontal rope 4a of the upper and lower horizontal ropes 4 is suspended in the width direction of the slope via the heads of the columns 2, and the uppermost horizontal rope 4 The protective net 8 is suspended over.

  In addition, the front side of the slope from the uppermost horizontal rope 4 a to the holding rope 7 is partitioned in a grid by the horizontal rope 4 and the vertical rope 5, and the protective net 8 is partitioned by the horizontal rope 4 and the vertical rope 5. It is applied from the outside (the front side of the slope) to the set area. Then, a pocket-like housing portion 9 is formed between the protective net 8 and the slope.

  The protective net 8 is fixed to the ropes 4, 5, 6, and 7 at the contact points with the ropes 4, 5, 6, and 7 using metal fittings such as cross clips and coupling coils. Also, the intersections of the ropes 4, 5, 6, 7 are fixed together with 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 integrated structure. It has become.

In the fallen object protection net 1 of the present invention, in addition to the above-mentioned various ropes 4, 5, 6, and 7, a rope for reinforcing the protection net (hereinafter referred to as a reinforcement rope) 10 is bent outside the protection net 8. It is provided.
Hereinafter, a reinforcing structure using the reinforcing rope 10 according to the present invention and a reinforcing method thereof will be described in detail in the following embodiments.

[Embodiment 1]
In the first embodiment, the reinforcing ropes 10 are installed in each of the sections P1 arranged in the uppermost stage of the area partitioned in a lattice shape.
Each section P1 at the top corresponds to an entrance into the fallen object protection net 1, and has the highest collision rate with the fallen object. Therefore, in the present embodiment, the uppermost section P1 is reinforced with the reinforcing rope 10 to avoid local damage to the protection net 8 and to maintain the entire fallen object protection net.

Specifically, as shown in FIG. 1, the reinforcing ropes 10 are provided for each section so as to intersect with each other along two diagonal lines.
The reinforcing rope 10 is fixed to the horizontal ropes 4 and the vertical ropes 5 at intersections with the ropes 4 and 5. In addition, in the center intersection part of the reinforcement rope 10, the reinforcement ropes 10 and 10 may be mutually connected. By intersecting the reinforcing ropes 10 at the center of the section in this way, the amount of energy absorption in the center of the section having a high damage rate is increased.

Further, in the present embodiment, as shown in FIGS. 2 and 3, the reinforcing rope is constituted by a total of four ropes per one set of the reinforcing rope. Specifically, two types of long and short ropes 10a and 10b are prepared, and these two ropes having different lengths are used in combination of a total of four.
Further, the bending rates of the ropes 10a and 10b having different lengths are set to be 102 to 106% larger for the short reinforcing rope 10a and to 105 to 110% for the long reinforcing rope with respect to the installation span L. The ropes 10a and 10b can be flexed and installed by giving them extra length for the installation span.
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 claims of the present invention.

In addition, the bending rate is selected based on the results of various preliminary experiments performed in consideration of the expansion / contraction rate and the load resistance of the protective net 8, the longitudinal elastic modulus of the reinforcing rope 10, and the like.
Specifically, the scale of falling rocks and the like at each installation location of the fallen object protection net 1 is predicted and assumed, and a value that can prevent the break of the protection net 8 within the range, and that the reinforcing rope 10 has a plasticity of the protection net 8 The flexure rate is chosen to satisfy both the values of breaking prior to deformation.

  Next, the shock absorbing effect of the structure having the above-described reinforcing rope 10 will be described with reference to FIGS. Also, the following description assumes a falling rock collision.

  First, when a falling rock D occurs above the slope, the falling rock D enters the falling object protection net 1 while jumping over the slope S as shown in FIG. Further, most of the falling rocks rush into the uppermost section P1 in the area where the protection net 8 is laid, and collide with the protection net 8. Further, as shown in FIG. 5, the protection net 8 weakens the impact energy of the rock fall D while flexing outward due to the collision with the rock fall D.

  Further, when the deformation of the protective net 8 progresses and the protective net 8 leans on the reinforcing rope 10, the remaining impact energy further deforms the protective net 8 and breaks the short reinforcing rope 10a of the reinforcing rope 10. That is, the impact energy in the late stage of the collision is weakened by both the protection net 8 and the short reinforcing rope 10a.

Here, the bending rate of the short reinforcing rope 10a will be described in detail. The bending rate of the short reinforcing rope 10a is a value that can prevent the plastic deformation of the protective net 8 as described above, and the plastic rope of the protective rope 8 It is set so as to satisfy both the values of breaking before deformation. Therefore, when receiving the impact energy, the short reinforcing rope 10a is broken, but the damage to the protective net 8 and the broken net are avoided.
That is, in the present reinforcing structure, a short reinforcing rope 10a is applied to the protective net 8 just before the protective net 8 is broken in order to keep the deformation of the protective net 8 within a range that does not break.

  As described above, in the present reinforcing structure, by providing the reinforcing rope 10 in a state where the reinforcing rope 10 is bent with respect to the protective net 8, the impact is reduced while making use of the shock absorbing ability of the protective net 8. In addition, by providing the reinforcing rope 10 outside the protective net 8, a time loss at the time of energy absorption is eliminated to avoid damage to the protective net 8, and furthermore, the reinforcing rope 10 is actively broken so that the reinforcing rope 10 Its shock absorbing ability is drawn to its upper limit. Furthermore, since the deformation of the protection net 8 stays within a range that does not break, the fallen object protection net 1 can be repaired only by replacing the short reinforcing rope 10a in the event of a disaster.

  In addition, among the reinforcing ropes 10 provided in the same section P1, the long reinforcing rope 10b is a spare rope and exerts an effect on the next falling rock. In other words, by providing the reinforcing ropes 10 twice, new damage to the protective net 8 during the repair period is prevented.

When the impact energy cannot be completely absorbed by the short reinforcing rope 10a, the long reinforcing rope 10b exerts its effect as a further reinforcement of the protective net 8.
That is, by changing the bending rates of the reinforcing ropes 10a and 10b, the absorption timing of the impact energy is shifted, so that the impact energy that has not been completely absorbed even when the short reinforcing rope 10a is broken can be further weakened and absorbed by the long reinforcing rope 10b. I have to.

[Test Example 1]
Hereinafter, Preliminary Experiment 1 relating to the selection of the bending rate is shown below.
1. Outline and purpose of the test To understand the relationship between the bending rate of the reinforcing rope and the damage state of the protective net for this reinforcing structure in which a reinforcing rope is provided outside the protective net.

2. Specimen and Test Content A Structure of Specimen A rectangular pedestal (frame) is formed by a vertical rope and a horizontal rope of φ16 mm, and the experiment is performed by regarding this pedestal as the uppermost section shown in the present embodiment. That is, a protective net was applied to a frame composed of vertical ropes and horizontal ropes, and reinforcing ropes were installed diagonally from the outside in a crossed state.
B Stand size 5m x 3m
C Protective 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 φ14 General-purpose twisted rope of steel wire specified in JIS G 3525 A total of two reinforcing ropes were installed one by one.
F Handling of Deflection Rate In this test, in order to accurately grasp the optimum value of the deflection rate, the deflection rate was selected together with the deformation rate (deformation amount) of the reinforcing rope having a correlation with the deflection rate.
The deformation rate is an index indicating how much the central part of the protective net (wire mesh) has deformed from a reference line connecting both ends horizontally with reference to the installation span of the reinforcing rope. The deformation rate was determined with the assumed amount of deformation of the protective net being 100%. Specifically, the deformation amount when a reinforcing rope having a deflection rate of 126% was used as a reference, and the deformation amount of the wire mesh at this time was determined as 100%. Further, as for the deformation rate, the amount of change per unit% (the width of the actually measured value) can be obtained larger than the bending rate, so that the use of this deformation rate enables more accurate verification.
G Falling object A 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 Deformation rate 30 to 50% (deflection rate 102.3 to 106.4%)
In the trial in this range, the soundness of both the protective net and the vertical ropes supporting the protective net was maintained, and the reinforcing effect of the reinforcing rope was clearly obtained.
B Deformation rate 60% (deflection rate 109.2%)
In this trial, the reinforcing effect was thin, the protective net was damaged, and the weight could not be supplemented.

4. Evaluation From the above experimental results, the effectiveness was particularly confirmed with a reinforcing rope having a deformation rate of about 30 to 50% and a bending rate of about 102 to 106%.

[Test Example 2]
Next, a preliminary experiment 2 relating to the selection of the bending rate is shown below.
1. Outline and purpose of the test In a structure in which two types of long and short reinforcing ropes with different flexure rates are provided two by 2 on the diagonal line of the same section, a relationship between the flexure rate of the reinforcement ropes and the damage state of the protective net is grasped. I do.

2. Specimen and Test Content A Structure of Specimen A rectangular pedestal (frame) is formed by a vertical rope and a horizontal rope of φ16 mm, and an experiment is performed by regarding this pedestal as the uppermost section shown in the present embodiment. That is, a protective net was applied to a frame composed of vertical ropes and horizontal ropes, and furthermore, reinforcing ropes were installed diagonally from the outside in a crossed state.
B Mount dimensions 5m long x 3m wide
C Protective 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 Long rope φ16 General-purpose twisted rope of steel wire specified in JIS G 3525 x 2 Short rope φ14 JIS G 3525 In this test, one pair (long rope x 2 + short rope x 2) of reinforcing ropes was installed on each diagonal line in each section in this test.
F Deflection rate The deflection rate was selected in combination with the deformation rate as in Test Example 1.
G Falling object A 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% (deflection rate 104.1%)
Reinforcement rope (short) Deformation rate 30% (deflection rate 102.3%)
According to this trial, the long reinforcement rope and the short reinforcement rope both broke,
Insufficient strength and energy absorption of both reinforcement ropes are considered.
B Test No2 to No4
Reinforcement rope (long) Deformation rate 50-70% (deflection rate 106.4-112.6%)
Reinforcement rope (short) Deformation rate 40-60% (deflection rate 104.1-109.2%)
In this trial, the soundness of the long reinforcement rope was maintained. The short reinforcement rope broke with the absorption of impact energy. That is, the soundness of the long reinforcing rope functioning as a spare reinforcing rope was secured while achieving a high shock absorption rate with the short reinforcing rope.
C Test No5
Reinforcement rope (long) Deformation rate 80% (deflection rate 116.4%)
Reinforcement rope (short) Deformation rate 70% (deflection rate 112.6%)
According to this trial, both the long reinforcing rope and the short reinforcing rope were broken, and the vertical rope supporting the wire mesh was also damaged. Therefore, it is considered that the strength of both reinforcing ropes and the energy absorption were insufficient.
4. Evaluation From the above experimental results, Test No. Good results were obtained in 2 to 4 trials.
That is, the effectiveness of the present reinforcing structure was shown by a combination of reinforcing ropes having a bending rate of about 105% to 110% (a deformation rate of 40 to 70%).

  According to further experiments by the inventor, the same tendency was observed even when the specification of the protective net was changed. In other words, it can be said that the reinforcing effect exhibited by the reinforcing rope does not depend on the specifications of the protective net, and is uniquely found by the bending rate of the reinforcing rope.

As described above, according to the present reinforcement structure, the provision of the reinforcing rope 10 outside the protective net 8 eliminates a time loss at the time of energy absorption, avoids damage to the protective net 8, and furthermore, connects the reinforcing rope 10 to the protective net. By bending the protection net 8, the shock absorption rate is increased while making use of the shock absorption capacity of the protection net 8.
As described above, in the present reinforcing structure, when the impact exceeding the energy absorption amount acts on the protection net 8 in a short time, the protection net 8 exhibits its superiority.

[Embodiment 2]
In the second embodiment, the reinforcing ropes 10 are set as one section P2 in all the sections arranged at the top of the area partitioned in a lattice shape.

  Specifically, as shown in FIG. 6, a reinforcing rope 10 is installed in parallel with the horizontal ropes 4a and 4b at a central portion between the uppermost horizontal rope 4a and the next horizontal rope 4b. Further, the entire length of the reinforcing rope 10 is longer than the entire width of the protective net 8 and is provided to be bent in the section P2 as in the first embodiment.

[Embodiment 3]
In the third embodiment shown in FIG. 7, as in the second embodiment, the reinforcing ropes 10 are installed with all the sections arranged at the uppermost stage as one section P2. The difference from the second embodiment is that the reinforcing ropes 10 are not provided in parallel with the horizontal ropes 4 but are provided one by one on two diagonal lines of this section.

[Embodiment 4]
In the fourth embodiment shown in FIG. 8, reinforcing ropes 10 are individually installed in all sections P of the laying area of the protective net 8. Further, similarly to the above-described first and third embodiments, a pair of reinforcing ropes 10 are provided on two diagonal lines of each section P. For this reason, since the reinforcement ropes 10 can be densely arranged in the entire area where the protective net 8 is laid, the energy absorption rate is further improved.

As described above, the reinforcing structure according to the present invention can exemplify various embodiments.
Further, the reinforcing structure of the fallen object protection net 1 described above can be applied not only to a newly installed fallen object protection net 1 but also to an already installed fallen object protection net. Further, the fallen object protection net 1 of the present invention is useful not only for falling rocks, but also for protection against landslides, rocks, and avalanches.

DESCRIPTION OF SYMBOLS 1 Falling object protection net 2 Post 3 Suspension rope 4 Horizontal rope 4a Top horizontal rope 4b Second horizontal rope 5 Vertical rope 6 Vertical auxiliary rope 7 Holding rope (bottom horizontal rope)
Reference Signs List 8 protection net 9 fallen rock storage section 10 reinforcement rope 10a short reinforcement rope 10b long reinforcement rope 11 anchor body P section P1 top section P2 all sections lined up in top section D falling object S slope

Claims (7)

In order to protect a falling object from the slope, a pillar erected on the slope, a lateral rope fixed at both ends to the side of the slope and suspended in the width direction of the slope via the pillar, And a protective net suspended below the slope from the horizontal rope, a fallen object protective net comprising:
Outside the protective net, the long and short plural kinds of reinforcing rope for reinforcing the protection network, said a deflection is set so as to prevent breakage of the protective network provided Rutotomoni, deflection of the long reinforcing ropes A falling object protection net characterized in that the condition and the bending of the short reinforcing rope are different .   2. The fallen object protection net according to claim 1, wherein the degree of bending of the reinforcement rope is set such that the reinforcement rope is broken prior to plastic deformation of the protection net. 3. The bending degree of the short reinforcing rope is set to be in a range of 104.1 to 109.2% in a bending rate of the reinforcing rope with respect to its installation span,
The bending degree of the said long reinforcement rope is set so that it may be in the range of 106.4-112.6% in the bending rate of the reinforcement rope with respect to the installation span, The Claims 1 or 2 characterized by the above-mentioned. Falling object protection net. A vertical rope is provided from the horizontal rope to the lower slope,
The reinforcing ropes, falling objects protection network according to any one of claims 1 to 3, characterized in that is provided so as to pass through the region defined by these horizontal rope and the vertical rope. The fallen object protection net according to claim 4 , wherein the reinforcing rope is provided on a diagonal line of a region defined by the horizontal rope and the vertical rope. The protective net is fixed to the horizontal rope and the vertical rope,
The reinforcing ropes, falling objects protection network according to claim 4 or 5, characterized in that it is connected to the fixed portion thereof and the rope and the protection network. In order to protect the falling object from the slope, a pillar is erected on the slope, and both ends of the horizontal rope are fixed to the sides of the slope, and suspended in the width direction of the slope via the pillar, and a protective net is provided. A method for reinforcing a fallen object protection net suspended from the horizontal rope below a slope,
Outside the protective net, the long and short plural kinds of reinforcing rope for reinforcing the protection network, provided with a deflection which is set to prevent the breakage of the protective network Rutotomoni, long reinforcing ropes A method for reinforcing a fallen object protection net, characterized in that the degree of bending is different from the degree of bending of a short reinforcing rope .

Images