JP4889107B2 - Falling object prevention fence and manufacturing method of falling object prevention fence - Google Patents

Description

  The present invention relates to a fallen object prevention fence that is provided along an expressway or the like and prevents the load from falling to the outside of a road when a load falls from a vehicle, and a manufacturing method of the fallen object prevention fence.

  If the cargo loaded on the vehicle traveling on the road falls from the loading platform of the vehicle for some reason, and falls to the outside of the road, a serious accident will occur if there are sidewalks or private houses outside the road. There is a risk of being connected. Furthermore, when the road is an elevated road and there are railways or intersecting roads below it, the fallen load may collide with the train or an opposing car, leading to a more serious accident.

  The most representative performance required for fallen object prevention fences to be installed on the side edges of such roads is the fallen object prevention fence standard in the design guidelines of the Japan Highway Public Corporation (December 2004). Can be mentioned. As the fallen object prevention fence standard, the standard that “a load of 300 kg at a height of 3 m from the road surface collides horizontally with the prevention fence at an angle of π / 12 rad (15 °) at a speed of 60 km / h” is cleared. Performance is required.

  Falling object prevention fences used for satisfying such standards are, for example, falling object prevention fences supported by support columns, a pair of upper and lower horizontal frames, a pair of left and right vertical frames, and such horizontal and vertical frames. The horizontal frame and the vertical frame are respectively formed from a pair of inner and outer frames and an outer frame, and the lattice network is formed from a plurality of horizontal lines and a plurality of vertical lines. Curl is provided near both ends of each horizontal line, or the joint with the vertical line joined to the left and right sides of each horizontal line is reinforced and welded with a weld bead of TIG or MIG, and curls are formed near both ends of each vertical line. The joints between the vertical lines and the horizontal lines joined to the bottom of each vertical line are reinforced and welded with TIG or MIG welding beads, and the curls or the joints are formed between the inner frame and the outer frame. Inserted into the hollow And, said curling or falling object preventing fence line portion adjacent to the center side of the lattice network of the joint is held between the inner frame and the outer frame have been disclosed (for example, Patent Document 1).

  Further, in the translucent sound insulation wall comprising a plurality of support columns built at regular intervals along the road and the translucent sound insulation panel attached between the support columns, the translucent sound insulation panel is made of synthetic resin. Translucent plate, vertical frame material arranged on the left and right vertical sides of the translucent plate, horizontal frame material arranged on the upper and lower horizontal sides, and a ledge that fixes the translucent plate to the vertical frame material and the horizontal frame material Each of the peripheral parts of the translucent plate is fixed and supported by a vertical frame member and a horizontal frame member with a deeply sufficient pinching margin, and the vertical frame member is applied to the front surface of the column. The substrate part and a side part bent substantially perpendicularly from the inner edge of the substrate part to the back surface and extending along the side part of the support column, and the longitudinal side of the translucent plate on the front side of the substrate part And a receiving groove portion for stopping the light transmission plate pressing side end portion of the pressing edge and a supporting groove portion for stopping the other end of the pressing edge are formed. The sound insulation panel is disclosed as a light-transmitting sound insulation wall for roads with a fall prevention function, which is fixed to the front portion of the column by a bolt penetrating the substrate portion of the vertical frame member (for example, Patent Document 2).

JP 2003-321817 A JP 2003-328325 A

  However, with the recent increase in the speed of vehicles, if the strength is designed based on a standard based on the assumption of a collision at a conventional speed of 60 km / h, the strength may be insufficient in light of the trend of the times. Moreover, in the conventional fallen object prevention fence as described in Patent Document 1, a grid net supported around the horizontal frame and the vertical frame is used, and the grid net is large due to the kinetic energy of the load having a weight of 300 kg. Because it is deformed, it is necessary not only for the moment of the collision but also for all of the time to be received by the grid network for a while, and if you want to satisfy the strength when the load collides at a higher speed than the previous speed, A substantial change in design is required according to the required strength, such as making the entire horizontal and vertical lines thick.

  Moreover, in the conventional fallen object prevention fence of patent document 2, the big level | step difference arises between a face plate and a frame by using the sound-insulation panel formed by supporting the circumference | surroundings of a face plate with a frame. Since the load that collided with the face plate collides with this step, not only the moment of the collision but also the kinetic energy of the 300 kg weight that subsequently collided is received by the frame. A large impact is applied to the support, and if you try to satisfy the strength when the load collides at a higher speed, the design of the frame and support will be greatly improved. It was necessary to change.

  The present invention has been made in view of the problems as described above, and provides a falling object prevention fence and a manufacturing method of the falling object prevention fence that require little design change even if the required strength is improved. It is something to be done.

In order to achieve the above object, the present invention is configured as follows. In other words, the falling object prevention fence according to the present invention extends along the roadway, and stands upright, a face plate provided on the front side of the post, and provided on the front side of the face plate. A face plate pressing member provided so as to sandwich both side ends of the face plate therebetween, the face plate is formed of a polycarbonate plate, and a cross section with a circular cross section is attached near the upper end between the columns. The headboard disposed on the back side of the face plate is adapted to support the face plate from the back side against an external force from the front side of the face plate, and further, the front face of the face plate and the front face of the face plate pressing member Is characterized in that the height of the step formed by each front surface is within 15 mm, and the front side end of the face plate pressing member is a curved surface or an inclined surface.

  According to the falling object prevention fence according to the present invention, the load that collides with the face plate slides on the surface of the face plate and the face plate pressing member. Since the response to the kinetic energy after that is almost negligible, even if the required strength is improved, the design of the structural members such as the face plate, face plate presser and struts is greatly improved. The need to make changes can be small.

In order to allow the load to slide on the front surface of the face plate and the front face of the face plate retainer, both the front face of the face plate and the front face of the face plate retainer are made smooth so as not to interfere with the sliding of the load, and the face plate collides with the load. It is necessary to support the kinetic energy at this moment and to repel the load in the opposite direction to some extent without the face plate itself deforming so much. As such a face plate, a metal plate may be used, but it is preferable to use a synthetic resin plate which is difficult to cause plastic deformation because the weight increases and plastic deformation is likely to occur relatively early in a metal material. Moreover, as the synthetic resin plate to be used, a polycarbonate plate that is less susceptible to cracking against impact and having a thickness corresponding to the required strength can be suitably used.

  Further, if the height of the step formed between the front surfaces of the front surface of the face plate and the face plate pressing member is within 15 mm, the risk of the load being caught by the step is reduced, and the sliding of the load is further increased. It can be smooth and is preferable.

Moreover, the manufacturing method of the falling object prevention fence concerning this invention is extended along the roadway, the support column installed upright, the face plate provided in the front side of the support column, the front plate side of this face plate, A falling object prevention fence provided with a face plate pressing member provided so as to sandwich the face plate therebetween, wherein the face plate is formed from a polycarbonate plate and subjected to external force from the front side of the face plate. On the other hand, in order to support the face plate from the back side, a cross section having a circular cross section is mounted near the upper end between the columns, and the head board is disposed on the back side of the face plate, and the front surface of the face plate and The front plate of the face plate presser is a face plate presser whose front side end is a curved surface or an inclined surface so that the step height formed by each front face is within 15 mm. A process of sandwiching the face plate It is characterized in that that.

  According to the manufacturing method of the falling object prevention fence according to the present invention, the load that collides the falling object prevention fence with the face plate slides on the surface of the face plate and the surface of the face plate pressing member, so that the face plate only at the moment of the collision. As the load on the face plate pressing material can be ignored, the response to the subsequent kinetic energy can be almost ignored. It can be a small falling object prevention fence that needs to be changed in design.

  According to the falling object prevention fence according to the present invention, the load that collides with the face plate slides on the surface of the face plate and the face plate pressing member. Since the response to the kinetic energy after that is almost negligible, even if the required strength is improved, the design of the structural members such as the face plate, face plate presser and struts is greatly improved. The need to make changes can be small.

  Further, according to the method for manufacturing a fallen object prevention fence according to the present invention, the load that collides the fallen object prevention fence with the face plate slides on the surface of the face plate and the surface of the face plate pressing member, so that only at the moment of the collision. Since the load on the face plate and the face plate presser can be ignored, the response to the subsequent kinetic energy can be neglected. Therefore, even if the required strength is improved, there is a significant increase in the components such as the face plate, the face plate presser and the column. It is possible to provide a small fallen object prevention fence that requires a simple design change.

  BEST MODE FOR CARRYING OUT THE INVENTION The best embodiment according to the present invention will be specifically described below with reference to the drawings.

  1 to 3 are front views showing an embodiment of a fallen object prevention fence according to the present invention. Falling object prevention fence 10 is made of polycarbonate on the front side of a column-shaped H-shaped steel column (hidden by face plate pressing member 2 to be described later in the front view) standing upright at a pitch of 2 m from wall height column K. A face plate 1 that is a resin plate is provided, and a face plate pressing member 2 that is a steel plate is attached to the front side of the face plate 1. The face plate 1 is integrally provided between the support columns, and the face plate pressing member 2 is attached to the front side of both side edges of the face plate 1, and the face plate pressing member 2 is attached to the support column by mounting bolts 21 from the front side.

  FIG. 2 is a cross-sectional view showing details of the AA cross section in FIG. Here, the side on which the face plate pressing member 2 is disposed is the front side α with the roadway. The support column 3 is a steel material having an H-shaped cross section, and is formed entirely using SS400 material defined in JIS-G3101. The front flange 31 and the rear flange 33 have a width of 200 mm and a thickness of 12 mm. The wave 32 used between the front flange 31 and the rear flange 33 is made of a steel material having a thickness of 8 mm, and these are integrally formed with a cross-sectional H-shaped column having an outer dimension of 200 mm × 200 mm. The face plate pressing member 2 is similarly formed using a SS400 material having a thickness of 9 mm, and both end portions of the face plate 1 which is a polycarbonate resin plate having a thickness of 12 mm are arranged between the front flange 31 and the face plate pressing member 2. The mounting bolt 21 is inserted from the front surface side α of the face plate pressing member 2, and the inserted mounting bolt 21 is screwed into a screw hole provided in advance in the front flange 31 of the support column 3 and tightened, whereby the face plate The face plate 1 is sandwiched between the pressing member 2 and the front flange 31. A packing material P made of a hard rubber material is sandwiched between the face plate 1, the face plate pressing member 2 and the front flange 31.

  Here, when the load collides obliquely from the front side α, the front side of the face plate 1 and the face plate pressing member 2 is made flat and smooth so that the load can slide on the face plate 1 and the face plate pressing member 2. The step height t formed by the front surface of the face plate pressing member 2 and the front surface of the face plate 1 is made as small as possible. The smaller the step height t, the better. However, it is preferable to set the height of the face plate pressing member 2 to about 15 mm or less in consideration of the need to ensure the strength of the face plate pressing member 2. Further, the front side end 22 of the face plate pressing member 2 is curved to make the load easy to slide, but as an inclined surface in addition to the curved surface, the angle between the front surface of the face plate 1 and the side surface of the face plate pressing member 2 is made as much as possible. It is preferable to keep it large. Furthermore, the face plate presser 2 is not limited to SS400 steel or the like as long as the required strength can be ensured, and an aluminum extruded profile or the like can also be used.

  FIG. 3 is a side view of the falling object prevention fence 10. The column 3 is firmly fixed on the wall rail K by the anchor bolt A, and the both ends of the face plate 1 are sandwiched and attached between the front flange 31 and the face plate pressing member 2 of the column 3 having a H-shaped cross section. Yes. In the vicinity of the upper end between the support columns 3, a cross section with a circular cross section G is attached and attached, and the cross section G also serves as a trunk edge that supports the face plate 1 from the back side. Moreover, the fall prevention rope C is inserted into the wave 32 of the support column 3, and the fall prevention rope C is attached to the face plate 1 provided with the support post 3 interposed therebetween, and the face plate 1 should be faced by an accident or the like. It is prevented from falling when it comes off between the presser member 2 and the column 3.

FIG. 4 is a plan view for explaining an example of a manufacturing method of the falling object prevention fence shown in the embodiment. When a 300 kg load T flies horizontally at an angle of 15 ° with respect to the face plate 1 provided on the front surface of the column 3 at a speed of 100 km, the kinetic energy Er of the load T is
Er = 1/2 × 3.0 / 9.8 × (27.78) ² = 118.1 kN · m.
When this kinetic energy is divided into the extending direction of the falling object prevention fence and the extending perpendicular direction orthogonal to the extending direction, the kinetic energy Erx in the extending direction is
Erx = 1/2 × 3.0 / 9.8 × (27.78 × cos15 °) ² = 110.2 kN · m
The kinetic energy Ery in the direction perpendicular to the extension is
Ery = 1/2 × 3.0 / 9.8 × (27.78 × sin15 °) ² = 7.9 kN · m
It becomes.

Here, as shown in FIG. 5, an iron ball W having a weight of 300 kg is dropped from the height of 6.56 m onto the face plate pressing member 2 at an angle of 15 ° with respect to the extending direction of the falling object prevention fence . The amount of deformation of the column 1 was measured by an experiment in a situation where the maximum load was applied to the column 1, and the ratio of the kinetic energy actually acting in the extending direction of the falling object prevention fence was calculated from the amount of deformation. In this experiment, the iron ball W slides down on the face plate pressing member 2 and the face plate 1 after the collision with the face plate pressing member 2, and the final deformation amount of the column 3 is in the extending direction. On the other hand, it was 8.0 mm.

The energy that the iron ball W brings into the fall prevention fence is
Er = (W / g) · g · h = 3.0 × 6.56 = 19.68 (kN · m)
Here, W: weight of iron ball (3.0 kN), h: fall height (6.56 m), g: gravitational acceleration (9.8 m / s ² ).
Of this energy, the energy brought in the extending direction is
Erx = Er · cos ² 15 ° = 18.36 (kN · m).

The external force required to cross H-shaped struts to form a plastic hinge in the extension direction and Fx1, iron ball Fx1 = σy · Z'y / h = 235 × 41.2 × 10 3/1350 × 10 -3 = 7.17 (kN).
Here, σy: standard yield point (235 N / mm ² ) of steel material (SS400) used for the struts, Z′y: plastic section modulus (41.2 cm ³ ) in the extending direction, h: strut height (1350 mm) .

Then, the energy Esx in the extending direction absorbed by the support column is
Esx = Fx1 · Δx = 7.17 × 8.0 × 10 ⁻³ = 0.06 (kN · m)
Here, Δx: deformation amount in the extending direction by experiment (8.0 mm)

Therefore, the ratio of the kinetic energy that actually acts in the extending direction of the falling object prevention fence is
Esx / Erx = 0.06 / 18.36 = 1/306
Therefore, the ratio of the kinetic energy actually acting in the extending direction of the falling object prevention fence is determined to be about 1/300 of the kinetic energy brought in by the load (iron ball).

In the perpendicular direction, the kinetic energy acting on the fallen object prevention fence has little room for consideration because the load collides at a shallow angle of 15 ° in the horizontal direction. Assuming that 15% works, the kinetic energy acting on the fallen object prevention fence at the moment of collision of the 300 kg load is
Kinetic energy acting in the extending direction: Ex = 1/300 × Erx = 0.35 (kN · m)
Kinetic energy acting in the extended perpendicular direction: Ey = (1−0.15) × Ery = 6.7 (kN · m)
It becomes. For the kinetic energy at the moment of the collision, by selecting a material that can be supported, the material for the face plate presser, and the column, and forming a falling object prevention fence, the load that collided with the face plate is repelled in the opposite direction to some extent. Thus, the load can be slid on the face plate and the face plate presser to prevent the load from falling to the opposite side of the roadway.

  The above-mentioned struts, face plates and face plate pressing members can be supported with respect to the kinetic energy Ex acting in the extending direction and the kinetic energy Ey acting in the extending perpendicular direction, thereby preventing falling of the load. It is shown that the load can be slid on the front face of the face plate and face plate presser. By selecting these members according to the required strength and making them capable of supporting the kinetic energy acting at the time of load collision, the load dropped from the vehicle can be placed on the front surface of the face plate and face plate presser. It is possible to slide, and as a result, the kinetic energy in the extending direction acting on the member can be greatly reduced, and the strength at the time of structural design can be estimated low.

It is a front view which shows one Embodiment of the fallen object prevention fence concerning this invention. It is sectional drawing which shows the detail of the AA cross section of FIG. It is a side view which shows one Embodiment of the fallen object prevention fence concerning this invention. It is a top view for demonstrating an example of the manufacturing method of the fallen object prevention fence concerning this invention. It is a side view which shows the outline of the experiment which verifies the kinetic energy which acts on the fallen object prevention fence concerning this invention.

Explanation of symbols

1 Face plate 2 Face plate presser 3 Prop 10 Falling object prevention fence

Claims (2)

A strut that extends along the roadway, stands upright, a face plate provided on the front side of the post, and is provided on the front side of the face plate so that both side ends of the face plate are sandwiched between the post. The face plate is formed of a polycarbonate plate, and a cross section having a circular cross section is inserted and attached near the upper end between the columns, and the face plate is disposed on the back side of the face plate. The headboard supports the face plate from the back side against an external force from the front side of the face plate, and the front face of the face plate and the front face of the face plate presser are step heights formed by the front faces. The falling object prevention fence is characterized in that the front side end of the face plate pressing member is a curved surface or an inclined surface. A strut that extends along the roadway, is erected, a face plate provided on the front side of the post, and a face plate provided on the front side of the face plate so as to sandwich the face plate between the post A method of manufacturing a fallen object prevention fence provided with a presser material,
Forming the face plate from a polycarbonate plate;
In order to support the face plate from the back side with respect to the external force from the front side of the face plate, a cross section with a circular cross-section is mounted near the upper end between the columns, and the head plate is arranged on the back side of the face plate And a process of
The front plate of the face plate and the front of the face plate pressing material, the step height formed by each front surface is within 15 mm, with the face plate pressing material whose front side end is a curved surface or an inclined surface, And a step of sandwiching the face plate with the support .

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