JP5415641B1 - Protection device such as rockfall - Google Patents

Abstract

A protective device for falling rocks and the like that can be obtained at low cost and has high durability.
The unit block includes a pair of flat disks 11 arranged opposite to each other and a rubber portion 14 interposed between adjacent disks 11 and covering an outer end face of the outermost disk. The disk 11 of the unit block is provided with ears 12 protruding in the outer diameter direction. A large number of unit blocks are arranged and arranged, and a plurality of unit blocks are connected by holding the ears of adjacent unit blocks with a connecting structure to form a protective net. Each disk 11 and the rubber part 14 of the unit block are integrated by vulcanization adhesion, and a through hole 17 is provided in a part covered with the rubber part 14 of the disk 11, and the rubber part 14 is attached to the two disk 11. Of these, the rubber material that has flowed into the through-hole 17 of one disk 11 is flowed toward the through-hole 17 of the other disk 11 so as to be molded.
[Selection] Figure 3

Description

  The present invention relates to a protection device for falling rocks and the like, particularly for an energy absorption type falling rock protection device using a net, which is installed on a slope of a natural ground and receives a falling rock or an avalanche to ensure the safety of roads and tracks. This protection device for rock fall, etc. is sometimes used in a deep mountain, such as a cliff on one side of the road, where it is difficult to recover if the vehicle falls. It can also be used as a protective device for a vehicle.

  In general, the rockfall protection device normally installed in the mountain is a structure that protects rockfalls with a group of wires that are tightly fixed to the concrete retaining wall and tensioned between the columns and stretched laterally. belongs to. This kind of rock fall protection device is designed to prevent the fall by giving a strong resistance to the fall rock by fixing the whole to the ground. Therefore, a protective structure capable of holding a higher resistance than the impact force of falling rocks is required, and the falling rock protection ability is not sufficient for the construction cost to increase to make a strong structure.

  On the other hand, an energy absorption type rock fall protection device is also known as a fall rock protection device. This type of rockfall protection device has a structure that consumes the impact energy of falling rocks by moving the structure greatly in the falling direction of falling rocks following the falling rock impact, and an example is patented This is disclosed in Japanese Patent No. 3699943 (Patent Document 1) and Japanese Patent No. 3699944 (Patent Document 2).

  In these protective devices described in Patent Documents 1 and 2, a large number of unit blocks made of a metal disc and a rubber laminate are connected via a ring to form a net. When a rockfall occurs, the net is largely deformed to absorb energy, and the impact energy is absorbed by elastically deforming the rubber of the unit block or elastically deforming the ring.

Japanese Patent No. 3699943 Japanese Patent No. 3699944

  In Patent Documents 1 and 2, in order to prevent the rubber plate from being peeled off or dropped off, the edge of the circular plate 11 is provided with a burr rising on the side in contact with the rubber plate. For this reason, the shape of the disk is complicated, and there is a problem that the processing cost increases and the incidence of defective products increases. In addition, by providing a hole penetrating from one disc of the unit block to the other disc after molding the rubber, and inserting a cylindrical lead rod into it, lead against the shear deformation of the rubber plate due to impact The rod functions as a damper to improve the durability of the rubber plate. However, it is not easy to procure and store the lead rod, and the cost increases due to an increase in the number of parts.

  An object of the present invention is to provide a protective device such as a falling rock which is low in cost and can obtain high durability without using a lead bar.

  The present invention that achieves the above object is a protective device such as a falling rock constructed by spanning a protective net having a large number of unit blocks arranged in a line between struts fixed to the ground. The unit block has at least a pair of flat disks opposed to each other and a rubber part interposed between adjacent disks, and the unit block is provided with an ear that is integral with the disk and protrudes in the outer diameter direction. In the protective device such as a falling rock that connects the plurality of adjacent unit blocks to constitute the protective net by holding the ears of the adjacent unit blocks with the connection structure, the rubber unit of the disc is covered. A through hole is provided in the part, and the rubber part is molded by flowing the rubber material flowing into the through hole of one of the two adjacent disks toward the through hole of the other disk. And each disk of the unit block Characterized in that the rubber portion are integrated by vulcanization.

  With such a configuration, the unit blocks can be easily moved with respect to each other, and each element of the protective net is in an unconstrained state without a connecting portion fixed. For this reason, any component of the structure is deformed and moved regardless of the impact force applied to any part of the structure, so that a local reaction force due to the impact does not theoretically occur. In general, the impact energy generated by the collision is represented by the product of the instantaneous impact force applied to the impacted structure and the time from the occurrence of the impact to the end (impact time). In the present invention, each part of the protective device is Since the impact time is extended by moving in the collision direction, the instantaneous impact force can be reduced. In other words, the protective net is deformed in the traveling direction of falling rocks, etc. under a relatively small load while flexibly receiving falling rocks, etc., and when a heavy load is applied, it is entangled so as to wrap the falling rocks while absorbing the collision energy. Deforms and stops with falling rocks. For the above reasons, according to the protective device of the present invention, high shock absorption can be obtained.

In addition, each part of the protective net has no permanent connection parts such as welding, forging, soldering, rivets, etc., and can be easily separated and replaced, making it easy to replace parts damaged by collisions with falling rocks, etc. Is obtained.

  In the present invention, the unit block has a configuration in which a rubber part is vulcanized and bonded to a disk. By doing in this way, the unit block which consists of a disc and a rubber | gum part can be handled collectively, and it is convenient for storage and conveyance, and also the assembly operation | work of the said protection net becomes easy, and it can manufacture with mass productivity and cheaply. As the circular plate, a metal plate, for example, an iron plate is used. The iron plate and rubber can be fixed without using an adhesive. Iron materials that are exposed outdoors usually rust on the surface or combine with oxygen, and the entire surface becomes iron oxide, so the surface of the iron plate is subjected to surface removal processing such as sand blasting and the iron itself Vulcanize after exposing internal tissue. As a result, the so-called composite material structure can be obtained by molecularly bonding iron and rubber via sulfur by utilizing the characteristic that iron forms a compound with sulfur and the molecular crosslinking characteristic of sulfur.

  The disc is flat and there are no burrs. Therefore, the manufacturing cost of the disk can be reduced, and the occurrence rate of defective products is also reduced. Also, the rubber material that has flowed into the through hole of one of the two adjacent disks is flowed toward the through hole of the other disk, and is interposed between the disks. A rubber column extending from one through hole to the other through hole can be formed in the rubber portion. Such a rubber column serves as a damper at the time of shear deformation of the rubber part, promotes the restoring force at the time of shear deformation of the rubber part, and adheres the disc and the rubber part at the time of shear deformation of the rubber part. Strengthen the mechanism. In addition, it promotes the composite material joint relationship between the rubber part and the disc. Therefore, the rubber column can suppress the separation / dropping of the disc and the rubber part during shear deformation. The rubber column can be formed simultaneously with the rubber part when the rubber part is vulcanized and bonded after the rubber part is molded. Therefore, a special rubber column forming step and a special material injection step are not required, and an operation of inserting a lead column as a damper, for example, performed in the manufacturing process of the seismic isolation laminated rubber is not required. Therefore, the unit block can be manufactured inexpensively with high mass productivity. The hole formed in the disk is preferably a long hole (oval) elongated in the circumferential direction of the disk.

  The disk constituting the unit block may be made of iron, steel, aluminum or other metal, or may be made of hard plastic. In any case, a material having weather resistance is desirable. Further, the disk is not limited to a literal circle, but may be a polygon. Further, the disk does not necessarily have an annular shape, that is, a donut shape, but by making it an annular shape, there is a high possibility that the external force applied by the impact can be evenly distributed. In addition to reducing the weight, the wind resistance can be reduced and the landscape is unlikely to be hindered.

According to the basic equation of impact engineering, the magnitude σ of the impact stress received by the impacted structure is expressed as follows: If the Young's modulus of the impacted material is E, the specific weight is ρ, and the impact velocity of the impacted object is v, σ = (E · ρ) ^1/2 × v. Therefore, it is not surprising that if each part of the protective device is made of a material having a Young's modulus lower than that of a material used in a general structure (usually steel material), the shock absorption is increased.

  The pair of disks of each unit block includes a total of four ears in a phase that is arranged at equal intervals in the circumferential direction. In this case, a connection structure is formed by a U-shaped member whose both ends are fixed to the ear part and a ring that passes through the space in the U-shaped member, and the ear part of the adjacent unit block is formed by the connection structure. By holding and connecting a plurality of adjacent unit blocks, a highly flexible protection net can be obtained. The ring winds the wire several times and leaves the ends of the wire unconstrained so that the wound wire can be loosened freely by the load applied at the time of impact. By appropriately selecting the material, thickness, and number of turns of the wire rod of the ring, the protective net can be configured in accordance with the magnitude of energy to be absorbed. Various materials can be used as the material of the wire. For example, in addition to the steel wire, carbon fiber, aramid fiber, or the like can be employed. When a falling rock collides with the protective net, the load is received by the protective net, and at the same time, the elastic deformation of the rubber part of the unit block and the shearing deformation of the rubber and / or free loosening of the ring due to the mutual pulling of the disk The shock energy is absorbed by. Further, when an impact load is applied, the wire is stretched so as to feed out the wound wire. Therefore, the impact energy can be absorbed while flexibly receiving the falling rocks and the like.

  This protection device is completed by stretching a support rope around the periphery of the protection net, supporting the periphery of the protection net with the support rope, and supporting the support rope with a support fixed to the ground. The support column can be installed, for example, in a direction perpendicular to the ground. Moreover, the auxiliary | assistant extending | stretching part which expands and deforms a support rope with the impact force at the time of a collision can be provided in the middle of a support rope. It is desirable that the support rope and the unit block and between the unit blocks are in an unconstrained state that allows relative movement between the support rope and the unit block.

  Here, the support rope is hooked to the unit block via another member (for example, screw shackle), or directly to the unit block itself of the protective net, etc. To be displaceable. When the protective net is rectangular, a single or multiple support ropes are stretched around the entire periphery of the rectangular edge, and a plurality of support ropes installed on the road, beams fixed between the support posts, Connect to a fixed rope.

  The auxiliary extending portion provided in the middle of the support rope can be applied with a part of the support rope that has been loosened. As a result, when an excessive load is applied to the protective net due to a collision with falling rocks, etc., the slack portion extends, so that the collision rope can absorb the collision energy smoothly and effectively without imposing a heavy load on the support rope. The support rope can be stretched and deformed smoothly. When the protective net is deformed by the collision with the protective net and the support rope is stretched and deformed, collision energy such as falling rocks is absorbed in stages, and finally the falling rocks are entangled in the protective net deformed in the collision direction. And stop. That is, the falling rocks do not instantaneously collide and stop, but impact impact time from the collision to the rest is prolonged because they collide in a plurality of stages. Due to the effect of extending the impact travel time, the concentrated impact load per unit time received by the protective net can be reduced.

  Further, the support column in the present invention connects a plurality of column members divided into two or more in the vertical direction so as to be able to bend each other, and connects adjacent column members with a reinforcing member having a planned breakage point to restrict bending. Can be configured. Furthermore, the support column can have a structure including stopper means for restricting the maximum value of the bending angle when the adjacent column members bend each other after the reinforcing member is broken.

  The split-type support here is provided with a reinforcing member so as to be bent and deformed by an impact force when a falling rock collides with the protective net. This reinforcing member may be broken in addition to being deformed when a falling rock collides, and if it is broken in this way, the force required for breaking is consumed from the collision impact force. It can be reduced to prevent damage to the protective net. Further, after the reinforcing member is broken, the stopper means for restricting the bending angle of the vertically adjacent column members is a structure that prevents the vertically adjacent column members from bending beyond a predetermined maximum bending angle. A tough spring steel plate or wire, or a stopper surface provided on the lower end face of the end face column and the upper end face of the lower pillar, which are opposed to each other in the vertical direction, can be applied. In other words, if the column members adjacent vertically are bent beyond a predetermined maximum bending angle, the protective net may be structurally inappropriately deformed by a collision, so this possibility is not a problem with the stopper means. Reduce to a degree.

  According to the protection device for falling rocks and the like of the present invention, when falling stones or the like collide with the protection net, elastic deformation and shear resistance of the rubber part in each of the many unit blocks, and further deformation of the ring connecting the unit blocks to each other. Since the collision energy is absorbed in stages, it is possible to reliably stop rockfalls. Moreover, even if it does not use a lead bar, the restoring force of the rubber part in each unit block can be increased, and high durability can be obtained. Therefore, it is possible to provide an inexpensive and long-life protection device such as falling rocks.

It is a partial front view which shows embodiment of a protective device. It is the elements on larger scale of the protection net which comprises the protection apparatus of FIG. (A) is a front view of a disk constituting a unit block of the protective net, (B) is a perspective view of a pair of disks, (C) is a cross-sectional view of the unit block, and (D) is a cross-section of the deformed unit block. FIG. It is a fragmentary perspective view of a unit block. It is a perspective view of the ring which connects a unit block. It is sectional drawing which shows other embodiment of a unit block. (A) is a front view in the auxiliary | assistant extending | stretching part of the support rope which supports a protection net, (B) is a front view at the time of extending | stretching of an auxiliary | assistant extending | stretching part. It is a side view of the support | pillar which supports a protection net. It is a fragmentary perspective view of a support | pillar. (A) And (B) is a fragmentary perspective view which shows other embodiment of a support | pillar, (C) is a side view at the time of support | pillar bending. (A) is a partial side view which shows other embodiment of a support | pillar, (B) is a side view at the time of support | pillar bending. (A) is a road top view which shows the example of installation of the protection apparatus for vehicles, (B) is a road sectional view. It is a partial front view which shows the protective device for vehicles. It is another road top view. (A) is a side view of the protective device immediately before the vehicle collision, and (B) is a plan view. (A) is a side view of the protective device after a vehicle collision, and (B) is a plan view. It is a partial front view of the protective device which shows other embodiment. FIG. 18 is a partially enlarged front view of a protective net constituting the protective device of FIG. 17. (A) is a front view of a connecting portion between unit blocks, (B) is a front view in a deformed state, and (C) is a perspective view showing an example of a connecting metal fitting for connecting unit blocks. (A) The figure is a front view which shows other embodiment of a support body, (b) A figure is the top view.

  A protection device M such as a rock fall of the present invention shown in FIG. 1 is an energy absorption type, and includes a horizontally-long rectangular protection net 30a composed of a large number of unit blocks 10 arranged vertically and horizontally. The peripheral portion of the protection net 30 a is supported by the support body 40, and the protection net 30 a is stretched so as to be perpendicular to the ground 1. The support body 40 includes a support rope 50 stretched around the peripheral edge of the protective net 30 a and support columns 60 fixed to a plurality of locations on the road surface 1. In FIG. 1, one protective net 30a is stretched between adjacent struts 60, but a horizontally long protective net may be stretched on three or more struts.

  As shown in FIGS. 2 and 3, each unit block 10 includes a pair of ring-shaped disks 11 and a ring-shaped rubber portion 14 interposed between the pair of disks 11. The rubber part 14 is fixed to and integrated with the disk 11 by vulcanization adhesion. As shown in FIG. 3, by covering not only between the disks 11 but also the outer end face of each disk 11 with the rubber part 14, the outer rubber part 14 can be elastically deformed when an impact is applied, The impact energy absorption effect is increased. Further, the weather resistance of the protective net 30a is improved. Since the rubber part 14 is easily colored, it is useful to improve the aesthetic appearance by appropriately coloring the rubber part 14.

  Each disk 11 has two ears 12 spaced 90 degrees on the outer periphery. As can be seen from FIG. 3 (B), the pair of disks 11 are shifted by 180 degrees in the circumferential direction, and the phase is set so that a total of four ears 12 are arranged at equal intervals in the circumferential direction. Each disk 11 does not have burrs or the like rising in the direction of the rubber part 14, and is formed in a flat plate shape having a uniform thickness including the ear part 12. Thereby, the manufacturing cost of the disc 11 can be reduced.

  As shown in FIG. 3C, a ring-shaped rubber portion 14 is interposed between the two disks. Therefore, when an impact force is applied, the molded rubber portion 14 is pulled in the X direction and the Y direction (shear deformation). The two ears A and B in the X direction and the two ears C and D in the Y direction are out of phase with each other, and thus are shifted by the impact force. The deformation (shear deformation) of the rubber portion 14 due to the displacement of the discs 11 achieves large energy absorption in combination with the deformation of the block connecting ring 20 described below. The deformation state is shown in FIG.

  A plurality of adjacent unit blocks 10 are connected through a connecting structure. A connection structure connects the ear | edge parts 12 of the adjacent unit blocks 10, and can be comprised by the U-shaped member 15 shown in FIG. 4, for example, and the ring 20 shown in FIG.

  As shown in FIG. 3 (A), each ear 12 is provided with a pair of attachment holes 13 penetrating in the thickness direction, and the pair of attachment holes 13 is U-shaped as shown in FIG. Both ends of the U-bolt 15 are inserted as shaped members. The U bolt 15 is a bolt in which both U-shaped leg portions are threaded, and a nut 18 is attached to the thread portion to prevent the U bolt 15 from coming off.

  When the protective net 30a is assembled, as shown in FIGS. 1 and 2, the unit blocks 10 are aligned and arranged so that the ears 12 of the different unit blocks 10 face each other in the vertical and horizontal directions. The four unit blocks 10 adjacent to each other are connected to each other by inserting the ring 20 into the space in the U bolt 15 of the opposite ear portion 12 at four locations in the circumferential direction. As shown in FIG. 5, each ring 20 is formed by winding a wire of a certain length a plurality of times, and at least one place is bound with an appropriate binding tool before being assembled to the protective net 30 a. And after assembling | attaching to the protection net | network 30a, each binding tool is removed, and both ends of a wire are left in a free state without restraining with a binding tool etc., and each ring 20 is comprised freely. The energy absorption capacity of the ring 20 can be adjusted by adjusting the number of windings of the wire or by selecting the thickness of the wire.

  In the embodiment shown in FIG. 3, the pair of discs 11 are covered with the rubber part 14 and only the ear part 12 is exposed, but the whole part including the ear part 12 may be covered with rubber. By doing so, the corrosion of the disk 11 can be prevented, and the durability and aesthetics of the protective net 30a are further improved.

  As shown in FIG. 3 (A), a portion (a portion excluding the ear portion 12) covered with the rubber portion 14 of each disc 11 constituting the unit block 10 penetrates in the thickness direction of the disc 11. A through hole 17 is provided. The through holes 17 can be arranged in an arc shape at a plurality of locations in the circumferential direction, for example. When the unit block 10 is manufactured, the pair of disks 11 are opposed to each other in parallel and the circumferential direction of the through holes 17 of both the disks 11 is put in the mold, and either one of the disks is used. The rubber part 14 is molded by injecting a rubber material from a region facing the outer end surface of the rubber member 11. Thereafter, the unit block 10 can be manufactured by performing a vulcanization operation.

  At the time of molding the rubber portion 14, the rubber material flows from the through hole 17 of one disk 11 toward the through hole 17 of the other disk 11 in a region sandwiched between the pair of disks 11. Due to the flow of the rubber material between the through holes 17, after the vulcanization operation, as shown in FIG. A rubber column 16 having a physical characteristic different from that of the other rubber part is formed integrally with the other rubber part 14 in a region corresponding to the above. The rubber column 16 reaches the through hole 17 of the other disk 11 from the through hole 17 of the one disk 11, and the shear deformation direction of the rubber part 14 (FIG. 3 ( The rigidity in (D) is high. Therefore, the rubber column 16 plays a role as a damper when the rubber portion 14 is shear-deformed, and promotes a restoring force when the rubber portion 14 is shear-deformed. Further, the rubber column 16 also has a function of strengthening a bonding mechanism between the disk 11 and the rubber part 14 when the rubber part 14 is sheared. From the above, it is possible to improve the durability performance and reduce the cost of the unit block 10 without using a lead bar.

  The number of the disks 11 constituting each unit block 10 is not limited to two, and for example, as shown in FIG. In this case, it is desirable to form the rubber column 16 so as to penetrate each of the four disks 11. Moreover, it is also possible to provide burrs (not shown) at the periphery of each disk 11 to suppress the peeling / dropping of the rubber part 14 interposed between the disks.

  The support rope 50 that supports the peripheral portion of the protective net 30a is looped around the unit blocks 10 in vertical and horizontal rows constituting the peripheral portion of the protective net 30a. The connecting method of the support rope 50 and each unit block 10 is arbitrary. For example, a screw shackle is passed through a U bolt inserted into the through hole 13 of the ear 12 of each unit block 10, and the support rope 50 is passed through this screw shackle. Can be connected. One support rope 50 is hung on the peripheral edge of the rectangular protective net 30a, and a plurality of locations including the four corners of the support rope 50 in a substantially rectangular ring shape are fixed to the support 60 and the upper end of the adjacent support 60. The beam member 41 is connected. By stretching the rectangular ring-shaped support rope 50, the protective net 30 a is stretched between adjacent struts 60 in a direction perpendicular to the ground 1. The vertical direction here is not limited to the direction perpendicular to the ground 1 but also includes an oblique direction slightly inclined with respect to the ground 1 and a direction of undulating upward from the ground 1.

  The rectangular-ring-shaped support rope 50 in FIG. 1 includes auxiliary extending portions 51 at a plurality of locations on four sides, for example, at substantially the center of the left and right sides and the upper and lower sides. In the auxiliary extending portion 51, as shown in FIG. 7A, base members 53 are attached to both ends of the turnbuckle 52, and a wire clip 54 is attached to each base member 53. The main body of the turnbuckle 52 is provided with a weakened portion 55 weakened by an annular notch or the like. The supporting rope 50 is passed through the two wire clips 54, a circular slack is formed between the two wire clips 54, and the slack is held by a turnbuckle to constitute the auxiliary extending portion 51. When falling rocks or the like collide with the protective net 30a supported by the support rope 50, an impact force propagates from the protective net 30a to the support rope 50, the support rope 50 is pulled, and the main body of the turnbuckle 52 is broken at the fragile portion 55. Therefore, as shown in FIG. 7 (B), the turnbuckle 52 is separated by the main body, and the support rope 50 is stretched and the slack 52 is eliminated. This stretching absorbs an impact caused by a collision of a protective net 30a described later. By adjusting the length of the turnbuckle 52, the amount of slack of the support rope 50 can be adjusted.

  The support column 60 that supports the protective net 30a and the support rope 50 is fixed to a concrete foundation 61 embedded in the ground 1, as shown in FIG. The support 60 is made of a steel mold that can be bent in a direction orthogonal to the net surface of the protective net 30a, for example, H steel. The support column 60 shown in FIG. 8 is divided into three parts vertically, a lower column member 60a fixed to the foundation 61, a middle column member 60b hinged to be bent on the lower column member 60a, and a middle column member 60b. The upper column member 60c is coupled to the upper column member 60b by a hinge pin 64 so as to be bent. The upper and lower column members 60a and 60b, 60b and 60c are connected and integrated by a reinforcing member 62 of a metal plate as shown in FIG. The reinforcing member 62 has a planned breakage portion 63 that is broken by an impact force when a falling rock collides with an intermediate portion. In order to maintain the posture of the support 60 after the collision, one end of a holding rope 67 may be attached to the support 60 as shown in FIG. By anchoring the other end of the holding rope 67 to the ground 1 in front of the protective device M, it is possible to suppress the tilting of the column after the collision of falling rocks or the like. The holding rope 67 is preferably provided with an auxiliary extending portion 51 shown in FIGS.

  When the protective net 30 a and the support rope 50 are deformed by an impact force, the impact force is propagated to the support column 60 and the reinforcing member 62. Due to the propagated impact force, the reinforcing member 62 between the upper and lower column members 60a and 60b and the reinforcing member 62 between the column members 60b and 60c break almost simultaneously, and the middle column member 60b with respect to the lower column member 60a. Is bent and tilted in the collision direction, and the upper column member 60c is bent and tilted in the collision direction with respect to the middle column member 60b. Also by the bending and tilting of the support column 60, the absorption of the impact at the time of collision is promoted.

  After the reinforcing member 62 of the support column 60 is broken by an impact force, it is desirable that the maximum value of the bending angle when the adjacent column members bend each other is regulated to be constant. As shown in FIG. 8, when the support 60 of the protective device M is held by the holding rope 67, the bending angle can be regulated by the extended holding rope 67. When it is difficult to give the holding rope 67 sufficient stretchability due to geographical factors or the like, for example, as shown in FIG. 10C, adjacent column members (in the drawing, the middle column member 60b and the upper column member). It is preferable that the support column 60 is provided with stopper means 65 for stopping the bending when 60c) is bent to a predetermined maximum bending angle α. For the stopper means 65, for example, a stopper plate 65a shown in FIG. 10 (A), a stopper wire 65b shown in FIG. 10 (B), and a stopper surface 65c shown in FIG. 11 can be applied. When these stopper means 65 are used, it is not necessary to install the holding rope 67 as shown in FIG. Therefore, when the protective device is installed on the side of the road, it is useful when it is difficult to install the holding rope 67 because the mountain side of the road is private land or the like.

  The stopper plate 65a in FIG. 10A is a vertically long rectangular plate having the same width as that of the vertically long reinforcing member 62. The middle portion has a mountain shape, and both upper and lower ends are screws 66 on the upper and lower ends of the surface of the reinforcing member 62. It is fixed with. The stopper plate 65a is a tough spring steel plate. In FIG. 10, when the reinforcing member 62 is broken and the upper column member 60c is bent with respect to the middle column member 60b, the upper and lower end portions of the stopper plate 65a are pulled and extended so as to follow this bending. When the bending angle α reaches the maximum value, the extension of the stopper plate 65a stops, and the stopper plate 65a stops the bending between the column members. Thus, after the reinforcing member 62 is broken, by restricting the bending angle of the column members adjacent in the vertical direction to a predetermined maximum angle α, inappropriate deformation of the protective net 30a can be suppressed. Even if the connecting portions such as the hinge pins 64 of the column members adjacent in the vertical direction are broken by impact, both the column members are always connected by the stopper plate 65a. Inappropriate deformation of 30a is more reliably prevented. Such an effect by restricting the bending angle of the column member is also obtained in the stopper wire 65b in FIG. 10B and the stopper surface 65c in FIG. 11B.

  The stopper wire 65b of FIG. 10 (B) is two connecting wires having the same length and having an intermediate portion, and both upper and lower ends are fixed to the upper and lower ends of the surface of the reinforcing member 62 with screws or the like. Similar to the stopper plate 65a, the two stopper wires 65b extend so as to follow this bending when the reinforcing member 62 is broken and the upper column member 60c is bent with respect to the middle column member 60b, and the bending angle α is increased. When reaching the maximum value, the extension stops and the bending between the column members stops.

  The stopper surfaces 65c shown in FIGS. 11A and 11B are formed on the upper end surface and the lower end surface of column members adjacent in the vertical direction. As shown in FIG. 11B, when the upper column member 60c is bent with respect to the middle column member 60b and the bending angle α reaches the maximum value, the edge portion 67 on the upper end surface of the column member 60b and the column member 60c The edge portions 68 of the end faces are in contact with each other. The surfaces of the edge portions 67 and 68 that are in contact with each other are stopper surfaces 65c.

  By installing the protective device M such as rock fall shown in Fig. 1 on the slope or flat surface of bedrock or natural ground, it catches rockfalls and avalanches and secures the safety of structures (roads, tracks, etc.) below the slope. can do. In addition, the protective device M described above can be installed as a protective fence at a suitable place on the road surface where the vehicle travels such as a general road, a highway, a parking lot, etc. Disasters can be prevented. For example, if the protective device M is installed in a place where one of the road sides falls into a cliff at a curve position of a road in a deep mountain, the vehicle can be prevented from falling. In these applications, the size and form of the protection net 30a are selected according to the road surface where the protection device M is installed. A vehicle protection device M installed on the highway 2 will be described with reference to FIGS.

  The highway 2 shown in FIG. 12A is a road in which the left main road 2a and the right main road 2b draw a curve in parallel. A median strip 2c is provided between the left main road 2a and the right main road 2b. The vehicle 3 travels in the direction of the arrow on each of the two main roads 2a and 2b. In the case of the left main road 2a, the protective device M is installed along the curved outer road shoulder, which is a place where there is a high possibility of a vehicle collision accident. In the case of the right main road 2b, the protective device M is installed on the curved portion of the central separation band 2c corresponding to the inner shoulder. Each protection device M is vertically installed on the road surface 1 as shown in FIG. Each protective device is installed on the road surface 1 by calculating the amount of deformation of the net because the protective net 30a is deformed in the opposite direction to the vehicle collision direction at the time of a vehicle collision. The protective net 30a has a size exceeding the vehicle size. When the protective device M is installed on the road surface 1 in this way, it is preferable to omit the holding rope 67 shown in FIG. 8 and use the stopper means 65 shown in FIGS. 10 and 11.

  The highway 2 shown in FIG. 14 is a road where the side road 2e branches from the main road 2d. In this case, the protective device M is installed along the branch road shoulder that branches at an acute angle between the main road 2d and the side road 2e.

  Hereinafter, the operation and effect of the protective device M according to the present invention will be described. As described above, falling objects, avalanches, vehicles, and the like are assumed as collision objects to the protective device M of the present invention, but the following description is for the case where the collision object is a vehicle. Even when the collision object is a falling rock, an avalanche, etc., the following actions and effects can be basically obtained.

  The vehicle 3 shown by the solid lines in FIGS. 15A and 15B is the vehicle 3 just before colliding with the protective net 30a. When the vehicle 3 collides with the protective net 30a, the vehicle 3 deforms the protective net 30a in the vehicle traveling direction as shown by a chain line in FIG. When the protective net 30a receives an impact from the collision vehicle, the impact force is transmitted from the center of the impact through the ring 20 and spreads outward uniformly. At that time, each ring 20 is connected to the other ring 20 at the connection point. Pulled outward, the protective net 30a is deformed according to the tensile force received by each ring. Absorption of extremely large energy is achieved by shear deformation of the rubber portion 14 of each unit block 10 and deformation of each ring 20.

  First, when the vehicle 3 collides with the protective net 30a, the vehicle 3 deforms the protective net 30a in the vehicle traveling direction as shown by a chain line in FIG. The collision load from the vehicle 3 is received by the protective net 30a, and at the same time, the collision energy is absorbed by the elastic deformation and shear resistance of the unit block 10 and / or the deformation of the ring 20, and the deformation of the protective net 30a starts. . At the same time, by free extension of the ring 20 between the unit blocks 10 and further the auxiliary extension 51, absorption of collision energy is promoted and the collision vehicle is flexibly received.

  When the impact force of the vehicle collision is great and a further large load is applied to the protective net 30a, the tensile impact force acts on the support rope 50 to extend the auxiliary extending portion 51, and the auxiliary extending portion 51 is attached in advance. The collision energy is absorbed by breaking along the expected fracture line. Then, as shown by the solid lines in FIGS. 16A and 16B, the support rope 50 and the protective net 30 a are greatly deformed in the vehicle traveling direction and are entangled so as to wrap the vehicle 3. Further, when the vehicle impact force exceeds the impact resistance of the reinforcing member of the support column 60 (notched so as to be broken when a large impact force is applied), the reinforcing member is broken and the support column 60 moves in the vehicle traveling direction. Finally, as shown by the chain lines in FIGS. 16A and 16B, the protective net 30a is further deformed and entangled so as to wrap the vehicle 3 from the top, bottom, left and right. And just before the protection net 30a entangles the vehicle 3, the vehicle 3 stops, and the deformation of the protection net 30a stops. The total collision energy until the vehicle 3 collides with the protective net 30a and stops is absorbed by extending the time rather than instantaneously due to deformation and breakage at various places including deformation of the protective net 30a. Accordingly, deviation from the road of the collision vehicle is reliably prevented, the concentrated impact load per unit time applied to the collision vehicle is reduced, and the portion where the structure contacts the vehicle is almost a rubber material portion. Damage to the vehicle 3 is reduced. The existing protective fence made of panels, etc., installed in the median strip of the expressway, etc. is a structure that bounces off the collision vehicle and pushes it back to the center of the road, which causes a secondary disaster on the contrary. Since the protective device according to the present invention has a function of deeply wrapping the vehicle that has entered and stopping it, such a secondary disaster can be prevented.

  Each unit block 10 shown in the protection net 30a of FIG. 1 can be directly connected by a connecting metal fitting, in addition to being connected by the ring 20. A specific example is shown in a protective net 30b in FIG.

  The protection net 30b shown in the embodiment of FIGS. 17 and 18 connects the adjacent unit blocks 10 with a pair of connection fittings 19 as a connection structure. As shown in FIG. 19, adjacent unit blocks are connected to each other by inserting the leg portions of the connection fitting 19 into the through holes 13 provided in the respective ear portions 12 of the disk 11 of the unit block 10. Here, the connection fitting 19 is made of spring steel, has an appearance similar to a U-bolt, and has a shape in which the top of the U-bolt is bent into a "<" shape. A nut 18 is attached to the threaded portion of both the legs of the connecting bracket 19 to prevent it from coming off. The specific mode of the connection fitting 19 is not limited to that shown in FIG. 19C, and a structure such as a coil spring (not shown) may be employed.

  When the adjacent unit blocks 10 are pulled away from each other, the connecting fitting 19 that connects the unit blocks 10 is pulled and deformed as shown in FIG. In this way, the collision energy can also be absorbed by the deformation of the connecting fitting 19. The energy absorbing power can be adjusted by adjusting the number of connecting fittings 19 or by selecting the thickness of the connecting fitting 19.

  Since the protective function by deformation when a collision object such as falling rock collides with the protective net 30b of FIG. 17 is the same as that of the protective net 30a of FIG. 1, detailed description thereof is omitted here.

  20A and 20B show another embodiment of the support 40. FIG. In the support body 40, the support rope 50 is configured by a vertical vertical rope and a horizontal horizontal rope, and loops are formed at both ends of each support rope 50. At each of the upper end and the lower end of the column 60 made of H-shaped steel, the bolt shaft of the bolt 69 is installed between the side plates, and the bolt 67 of the bolt 69 is passed through the loop and then the nut is tightened on the bolt shaft. It comes to prevent. In this case, the support rope 50 can be stretched in a rectangular shape by supporting one end of each of the vertical rope and the horizontal rope with a single bolt 69. The protective device M is completed by attaching the periphery of the protective net 30a to each support rope 50 using a screw shackle or the like.

  In the protection net 30a or 30b described above, the unit block 10 has a difference in the amount of shear deformation generated in the rubber portion 14 depending on the distance from the collision position when a rock fall or the like collides, but the shear block increases the collision energy. Absorb less or less. In addition, by rupturing the material to be ruptured installed on the support column 60, the support rope 50, etc., each of the collision energy is absorbed, and at the same time, the entire structure is greatly deformed in the moving direction of the collision object due to the rupture of the part. At the same time as the impact time delay effect, the large displacement of the protective device itself absorbs the large energy of the collision object. An experimental example demonstrating this will be described.

The protective device M shown in FIG. 1 is designed to have a collision energy of 1000 kJ. For example, when a collision object with a weight of 1 ton (for example, a normal passenger car) is crashed into the protective device M at a speed of 150 km / h and the collision energy is calculated,
Collision energy = (m × v ² ) /2=88.5 ton · m
[Where m: vehicle weight (ton) v: super speed of the collision vehicle (km / h)]
Here, gravitational acceleration = 9.8 m / sec ² 100 ton · m = 1000 kJ
Therefore, 88.59 ton · m = 885.9 kJ
If such a vehicle collides with the protective net 30a at an angle of 30 °,
Collision energy = 885.9kJ × Sin30 ° = 443kJ
Therefore, it can be seen that the protective device M sufficiently protects even when an object having a weight of 1 ton collides. In fact, even an object having a weight of 3 tons can be sufficiently safely entangled, and since the safety factor 10 is expected in this design, it is known that the enclosure can be protected to some extent up to a weight of about 5 tons in a safe state.

The effect of the reinforcing plate is as follows. Assuming the case where the support is 150 × 150 H-shaped steel and a SS400 steel plate having a thickness of 3 mm is used as a backing plate, the area of the fracture surface is 3 mm × 150 mm = 450 mm ² . Since the breaking stress of SS400 is 40 kg / mm ² , the force for breaking the contact plate is 40 kg / mm ² × 450 mm ² = 18 ton. Since there are four contact plates in one span, a breaking force of 18 ton × 4 = 72 tons is required to simultaneously break the four contact plates. Therefore, when the object hits the protective device M and four reinforcing plates (pads) between one span are cut and the support column is tilted forward, the instantaneous impact force of 72 tons can be erased from the collided object.

M Protection devices such as falling rocks 1 Ground, road surface 3 Vehicle 10 Unit block 11 Disc 12 Ear part 14 Rubber part 15 U bolt (U-shaped member, connecting structure)
16 Rubber pillar 17 Through-hole 19 Connection fitting (connection structure)
20 Ring (linkage structure)
30a, 30b Protective net 40 Support body 50 Support rope 51 Auxiliary extension 53 Brake fitting 60 Post 60a-60c Column member 62 Reinforcement member 65 Stopper means

Claims (6)

A protective device such as a falling rock constructed by passing a protective net having a large number of unit blocks arranged in a line between struts fixed to the ground, wherein the unit blocks are at least a pair of flat circles arranged opposite to each other. The unit block is provided with an ear portion that is integral with the disc and protrudes in the outer diameter direction, and has an ear portion of the adjacent unit block. In a protective device such as a falling rock that connects the plurality of adjacent unit blocks to form the protective net by holding the connection structure,
A through hole is provided in a portion covered with the rubber part of the disk, and the rubber part passes through the other disk with the rubber material flowing into the through hole of one of the two adjacent disks. A protective device for falling rocks, etc., which is molded by flowing toward a hole, and each disk of a unit block and a rubber part are integrated by vulcanization adhesion.   A pair of discs has a total of four ears arranged in a phase that is arranged at equal intervals in the circumferential direction, and passes through a U-shaped member having both ends fixed to the ear and a space in the U-shaped member. The protective device for falling rocks or the like according to claim 1, wherein the connecting structure is formed with a ring, and the ring is wound around a wire several times and left unconstrained.   The protective device for falling rocks or the like according to claim 1 or 2, wherein a support rope is stretched around a peripheral portion of the protective net, the peripheral portion is supported by the support rope, and the support rope is supported by a support column.   The protective device for falling rocks and the like according to claim 3, wherein the supporting rope has an auxiliary extending part that extends and deforms the supporting rope by an impact force received from the falling rocks and the like in the middle.   The support column has a configuration in which a plurality of column members divided into two or more in the vertical direction are connected to each other so that they can be bent, and the adjacent column members are connected to each other with a reinforcing member having a planned breakage point, and the bending is restricted. The protective device for falling rocks or the like according to any one of claims 1 to 4.   6. The protective device for falling rocks and the like according to claim 5, wherein the strut includes stopper means for restricting a maximum value of a bending angle when the adjacent column members bend each other after the reinforcing member is broken.

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