JPH05295713A - Impulse force absorbing device for drop stone preventive body - Google Patents

Abstract

PURPOSE:To improve the impulse absorbing faculty and prevent deformation and breakage. CONSTITUTION:A plurality of supporting pillar bodies 2 are arranged, keeping an intervals, and a supporting leg part 3 consisting of coil springs having each elastic restoration force is fixed at the lower edge of the supporting pillar body 2. Further, a net body 4 is installed between the supporting bodies 2. Further, the supporting leg part 3 is fixed on a foundation concrete 5 through a foundation supporting pillar 4. When the impulse force of a drop stone R is applied on protective net 1, the supporting leg part 3 is elastically deformed, and absorbs the impulse force effectively, and also the breakage deformation of the protecting net 1 is reduced. When the impulse force of the drop stone R fades away, the protective net 1 is returned to an original position by the elastic restoration force of the supporting leg part 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rockfall preventive body that absorbs the impact of rockfall, and more particularly to an impact force absorbing device for a rockfall preventive body such as a preventive wall, a preventive mesh and a preventive fence.

[0002]

2. Description of the Related Art As a conventional rock fall preventer of this type, for example, a pillar structure for rock fall preventive net installation disclosed in Japanese Utility Model Laid-Open No. 56-138909 is known. This rockfall prevention body fixes a plurality of struts to the embedded concrete that is the foundation of the slope with an anchor member, provides a net between these plurality of struts, and further supports the load applied to the stanchions by rockfall. A supporting member such as a wire is stretched over the support column.

[0003]

In the above-mentioned conventional rock fall prevention body, the support is firmly fixed to the foundation and the load of rock fall is supported by the rigidity of the support. The pillar is easily deformed and damaged, and has a surface that is vulnerable to impact force. And to prevent this,
A support member is stretched over the pillar to prevent the pillar from being deformed or damaged by the load. However, even if the support member is reinforced, the pillar is deformed when a load of a certain amount or more is applied, and the rockfall preventing function afterwards is lost, and there is a problem that repair or re-construction must be performed.

Therefore, an object of the present invention is to provide an impact force absorbing device for a rockfall preventive body which is excellent in impact absorbing ability and is resistant to deformation and damage.

[0005]

SUMMARY OF THE INVENTION The present invention provides a rockfall prevention body provided with support legs having an elastic restoring force.

[0006]

[Function] When the impact force of rockfall is applied to the rockfall prevention body, the support leg portion is elastically deformed to absorb the impact force, and when the impact force disappears, the rockfall prevention body is restored by the elastic restoring force of the support leg portion. Return to the position.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4 show a first embodiment of the present invention, in which a prevention net 1 is used as a rock fall prevention body, and a plurality of pillar main bodies 2 made of metal or the like are arranged at intervals. A support leg portion 3 having an elastic restoring force is fixed to the lower end of the column main body 2, and the support leg portion 3 is a coil spring formed by closely winding a wire made of metal, for example, spring steel,
The lower ends of the support legs 3 are fixed to a foundation pillar 4, and the foundation pillar 4 is fixed to the ground by foundation concrete 5. A mesh body 6 made of metal or the like is stretched over the entire surface of the pillar body 1. The mesh body 6 is formed by forming a wire into a hexagonal mesh and has elasticity, and is further shown in FIG. Thus, the slack portion 6A is formed. In addition, the pillar body 2, 2
A plurality of wires 7 made of metal or the like for reinforcement are stretched in parallel between them, and a wire 8 made of metal or the like is stretched in an X shape between the adjacent pillar bodies 2 and 2. There is.

The operation of the above structure will now be described. The impact force of the falling rock R, that is, the kinetic energy is the prevention net 1.
In addition, the support leg portion 3 made of a coil spring is deformed, the pillar main body 2 is tilted or tilted up to about 90 degrees, and the elastic deformation of the support leg portion 3 absorbs the kinetic energy of the rock fall R. Then, when the falling rock R stops and the force acting on the strut main body 2 becomes only a static load that is smaller than the kinetic energy, the falling rock R is pushed forward by the elastic restoring force of the support leg portion 3, and the strut main body 2 is removed. Position or stand up. If the weight of the falling rock R is larger than the elastic restoring force of the support leg 3, when the observer removes the falling rock R, the elastic restoring force of the support leg 3 causes the column main body 2 to stand up and collapse. Even when removing the rockfall R from the prevention net 1, the support leg 3 is attached to the rockfall R.
Since the elastic restoring force of 1 works, the rockfall R can be removed relatively easily.

As described above, according to the present invention, since the supporting net 3 having the elastic restoring force is provided on the prevention net 1 which is a rock fall prevention body, when the impact force of the rock fall R is applied to the prevention net 1. The supporting legs 3 are elastically deformed to absorb the impact force and have an excellent impact absorbing ability, and the prevention net 1 is elastically deformed as compared with the conventional one that receives the impact force due to rigidity. Since the shock absorbing force is absorbed, the damage and deformation of the prevention net 1 decreases, and when the impact force of the falling rock R disappears, the elastic restoring force of the support leg 3 causes the prevention net 1 to return to its original position. , Easy to maintain.

Further, as an effect of the embodiment, a plurality of pillar bodies 2 are arranged at intervals, all of the pillar bodies 2 are provided with the support leg portions 3, and the net body 6 and the wires 7 are used for all the pillar bodies 2. By integrally connecting the support legs 3 with respect to the falling rock R, all the support legs 3 are elastically deformed as shown in FIG. 4, the impact force is effectively absorbed, and the elasticity of all the support legs 3 is increased. The restoring force enables the prevention net 1 to return to its original position. Further, by providing the elastic net body 6 with the slack portion 6A, even if the falling rock R collides with the net body 6, the net body 6 itself expands and contracts, so that the impact force is gently transmitted to the column main body 2.

5 to 8 show a second embodiment of the present invention. The same parts as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. A supporting wire 9 such as a wire rope or a piano wire is fixed to the top of the main body 2, and the wire 9 is fixed to the ground in front by an anchor 10. The supporting wire 9 is shown in FIG.
9A of upper wire rods and 9B of lower wire rods,
The upper end side of the upper wire 9A is fixed to the ground by the anchor 10, and the lower end side of the upper wire 9A and the upper end side of the lower wire 9B are overlapped with each other to form an overlapping portion 11, and the upper wire 9A of the overlapping portion 11 The lower wire 9B and the lower wire 9B are tightly connected and fixed by two tightening members 12 at intervals. Reference numeral 13 is a terminal protrusion fixed to each end of the upper wire 9A and the lower wire 9B. In that case, the fastening member 13 is attached to the U bolt 12A and the stop plate 12 as shown in FIG.
It shows that the nut 12C is screwed through B.

When the impact force of the rockfall R, that is, the kinetic energy, is applied to the prevention net 1, a tensile force acts on the supporting wire 9 so that the upper wire 9A and the lower wire 9B resist the tightening force of the tightening member 12. Try to slide. When the tensile force applied to the wire rod 9 exceeds the limit static friction resistance due to the tightening member 12, the upper wire rod 9A and the lower wire rod 9B of the overlapping portion 11 release the state of the overlapping portion 11 as shown in FIG. 7 (A). Sliding in the direction
13 is locked to the tightening member 12. At the same time, the supporting legs 3 are elastically deformed due to the sliding, and the column main body 2 is inclined. Further, when a larger tensile force is applied, the two tightening members 12 abut against each other as shown in FIG. 7B by further sliding in the direction of releasing the state of the overlapping portion 11. In this way, while the upper wire 9A and the lower wire 9B of the overlapping portion 11 slide against the tightening force of the tightening member 12, a considerable amount of energy is lost due to friction, and further, the supporting legs are not supported. Due to the elastic deformation of the portion 3, the impact force of the falling rock R is absorbed, and further, in the first stage, the supporting wire 9 slides while the tightening member 12 is stationary, and
At the stage, the tightening member 12 is caused by the engagement between the end protrusion 13 and the tightening member 12.
Slides while moving, and the supporting leg portion 3 elastically deforms in accordance with the inclination of the column main body 2, so that the shock absorbing ability is high. Then, when the falling rock R stops and the force acting on the column body 2 becomes only its own weight smaller than the kinetic energy, the column body 2 is erected in its original position due to the elastic restoring force of the support leg 3.

As described above, according to the present invention, the prevention net 1 which is a rockfall prevention body is provided with the support leg portion 3 having an elastic restoring force, and the support wire 9 fixed to the prevention net 1 and the support wire 9 fixed to the earth pile. The overlapping parts 11 are formed by superimposing the end portions of and the overlapping parts 11 and the overlapping parts 11 are tightly bound together by the tightening members 12 provided at a plurality of intervals to form the overlapping parts 11.
9B is provided with the terminal projections 13 and 13 so that the tensile force applied to the supporting wire 9 allows the terminal projection 13 to be locked to the fastening member 12 and the fastening member 12 to move. While the upper wire 9A and the lower wire 9B of the overlapping portion 11 are sliding against the tightening force of the tightening member 12, a considerable amount of energy is lost due to friction, and further, the supporting leg 3 The elastic deformation absorbs the impact force of the falling rock R, and the impact absorbing ability becomes excellent.

9 and 10 show a third embodiment of the present invention. The same parts as those of the first and second embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. In this example, an essential part of one supporting wire 9 is formed in a loop loop 14 to form an overlapping part 15, and the overlapping part 15 is tightened and fixed by two tightening members 12 at intervals. ing. Therefore, when the impact force of the falling rock R, that is, the kinetic energy is applied to the prevention net 2, the tightening member at the first stage as in the second embodiment.
The wire 9 moves in the direction of releasing the loop 14 as shown in FIG. 10 (A) against the tension of 12 and both ends of the loop 14 are locked by the two fastening members 12. When a tensile load is further applied, in the second stage, the wire rod 9 is further extended while moving the wire 9 in the direction to release the overlapping portion 15 as shown in FIG. 10B, and the two fastening members 12 collide with each other. To meet. In this way, a considerable amount of energy is lost due to friction while the wire 9 of the overlapping portion 15 of the loop 14 moves against the tightening force of the tightening member 12, and the tilt of the strut body 2 is increased. Accordingly, the support leg portion 3 is elastically deformed to absorb the impact force of the falling rock R. Then, when the rockfall R stops and the force acting on the pillar body 2 becomes only the static load smaller than the kinetic energy, the pillar body 2 is erected in its original position due to the elastic restoring force of the support leg 3.

FIG. 11 shows a fourth embodiment of the present invention, in which the same parts as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. A pillar 4 is formed in a prismatic shape, and a stacked leaf spring in which a plurality of leaf springs are stacked is used as the support leg portion 3A. Also in this example, when the impact force of the falling rock R is applied to the prevention net 1, it is supported. The leg portion 3A elastically deforms to absorb the impact force and has an excellent impact absorbing ability, and the breakage and deformation of the prevention net 1 is small and has the same action and effect as those of the first embodiment. Is used for the support leg portion 3A, the pillar main body 2 can be smoothly inclined in the front-rear direction.

FIG. 12 shows a fifth embodiment of the present invention, in which the same parts as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. The pillar 4 is formed in a prismatic shape, and a hollow rubber spring is used as the support leg portion 3B. In this example as well, when the impact force of the falling rock R is applied to the prevention net 1, the support leg portion 3B is elastically deformed. As a result, the shock absorbing force is absorbed and the shock absorbing ability is excellent, and the damage and deformation of the prevention net 1 is small, and the same action and effect as those of the first embodiment are obtained.

FIG. 13 shows a sixth embodiment of the present invention. The same parts as those of the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. The supporting leg portion 3C connecting to the support column 4 is formed by embedding a metal coil spring 16A in a rubber spring 16 having a substantially hollow cylindrical shape. In this example as well, the impact force of the falling rock R acts on the prevention net 1. When added, the supporting legs 3 are elastically deformed to absorb the impact force and have an excellent impact absorbing ability, and the damage and deformation of the prevention net 1 are small, and the same action and effect as those of the first embodiment, Due to the combination of the rubber spring 16 and the coil spring 16A, it is possible to incline the strut main body 1 by 90 degrees or more and obtain a good elastic restoring force that allows the strut body 1 to return to the original state.

FIG. 14 shows a seventh embodiment of the present invention, in which the same parts as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. The thing using the wall 1A is shown, This prevention wall 1A is the pillar main body 2 which consists of a plurality of precast concrete, for example.
A are spaced apart from each other, a cross beam 6B made of a plurality of precast concrete is provided on the strut body 2A, and a supporting leg portion 3 having an elastic restoring force is fixed to the lower end of the strut body 2A. An anchor portion 5A, which is formed by extending the wire rod in the downward direction and having a U-shape, is embedded and fixed in the concrete foundation 5.

As described above, in the present invention, since the concrete prevention wall 1A which is a rock fall prevention body is provided with the support leg portion 3 having an elastic restoring force, the impact force of the rock fall R is applied to the prevention wall 1A. Since the support leg 3 elastically deforms and absorbs the impact force, the support leg portion 3 has an excellent impact absorbing ability, and the prevention wall 1A has The elastic deformation absorbs the impact force, reducing the damage deformation of the prevention wall 1A.
When the impact force of the falling rock R disappears, the elastic restoring force of the support leg portion 3 returns the prevention wall 1 to the original position, which facilitates maintenance.

FIG. 15 shows an eighth embodiment of the present invention, in which the same parts as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. The pillar 4 and the pillar 4 are formed in a prismatic shape, and a stacked leaf spring in which a plurality of leaf springs are stacked is used as the support leg portion 3A. The upper end of the support leg portion 3A is fixed to the pillar body 2 and the lower end is It is attached to the foundation column 4 via the mounting shaft 17, and the foundation column 4
The mounting shaft 17 is formed with an escape hole 17 slidably upward toward the rear, and a stopper 18 for stopping rotation is integrally provided at the lower end of the support leg 3A. And falling rock R
When an impact force is applied to the preventive body by means of, the stopper portion 18 prevents the support leg portion 3A from elastically deforming to absorb the impact force, or when a large impact is released to release the stopper portion 18 from being stopped. The mounting shaft 16 moves along the escape hole 17 to absorb the impact force. Also in this example, when the impact force of the falling rock R is applied to the prevention net 1, the support leg portion 3A elastically deforms to absorb the impact force and has an excellent shock absorbing ability, and the damage prevention deformation of the prevention net 1 is small. It has the same operation and effect as the first embodiment, and since the mounting shaft 16 moves along the escape hole 17, the column main body 2 can be tilted not only in the front-back direction but also in the left-right direction.

The present invention is not limited to the above-described embodiment, but various modifications can be made within the scope of the present invention. For example, the length dimension and material of the supporting leg portion can be appropriately selected. In addition, the support leg may have various elastic restoring forces, such as a double use of large and small coil springs, a combination of coil springs and leaf springs, or a combination of leaf springs and rubber springs. Can be used.

[0022]

As described above, the present invention provides a shock-absorbing device for a rock-fall preventive body which is excellent in shock-absorbing ability and which is not easily deformed or damaged because the rock-fall preventive body is provided with supporting legs having elastic restoring force. be able to.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view of a prevention net according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged perspective view of the prevention net showing the first embodiment of the present invention.

FIG. 3 is a sectional view of a supporting leg portion showing a first embodiment of the present invention.

FIG. 4 is a plan view of a prevention net that has received rockfall according to the first embodiment of the present invention.

FIG. 5 is a side view of the prevention net showing the second embodiment of the present invention.

FIG. 6 is a side view of an overlapping portion showing a second embodiment of the present invention.

FIG. 7 is an explanatory diagram of a working state showing the second embodiment of the present invention.

FIG. 8 is a sectional view of a fastening member showing a second embodiment of the present invention.

FIG. 9 is a side view of an overlapping portion showing a third embodiment of the present invention.

FIG. 10 is an explanatory diagram of a working state showing the third embodiment of the present invention.

FIG. 11 is a sectional view of a support leg portion showing a fourth embodiment of the present invention.

FIG. 12 is a sectional view of a main part of a support leg portion showing a fifth embodiment of the present invention.

FIG. 13 is a sectional view of an essential part of a support leg portion showing a sixth embodiment of the present invention.

FIG. 14 is a sectional view of a prevention wall showing a seventh embodiment of the present invention.

FIG. 15 is a sectional view of a supporting leg portion showing an eighth embodiment of the present invention.

[Explanation of symbols]

 1 Prevention net (falling stone prevention body) 1A Prevention fence (falling stone prevention body) 2,2A Strut body 3,3A, 3B, 3C Support leg

Claims (1)

[Claims] 1. An impact force absorbing device for a rock fall prevention body, wherein a support leg portion having an elastic restoring force is provided on the rock fall prevention body.