JP4195708B2 - Guard post - Google Patents

Description

  The present invention relates to a protective fence post installed along a roadway.

  The protective fence for vehicles prevents the vehicle from falling from the roadway, and has a structure in which a horizontal beam is spanned between a plurality of support columns (hereinafter referred to as “protection fence support columns”) standing at predetermined intervals. I have.

  From the viewpoint of preventing the vehicle from falling, it is better to increase the rigidity / strength of the protective fence, but if it is made larger than necessary, there is a risk that the driver and the passenger will be damaged greatly due to the impact at the time of collision. There is also a possibility that a vehicle that has contacted or collided with the protective fence will be bounced back by the protective fence and spin on the roadway side, causing a secondary disaster.

  For this reason, in a conventional protective fence, when a vehicle contacts or collides and an external force of a certain level or more is applied, the collision (impact) energy is first absorbed by the crushing and bending deformation of the cross beam, and then the elastic deformation of the support fence post In addition, the impact energy is absorbed by plastic deformation such as buckling and buckling, which minimizes damage to the driver and passengers and prevents the vehicle from bouncing back to the roadway. (For example, refer to Patent Document 1).

  As shown in FIG. 8A, the protective fence support 100 of Patent Document 1 includes a pedestal 101 fixed to a foundation constructed on the side of the roadway and a support main body 102 erected on the pedestal 101. The strut body 102 is tilted rearward at the time of collision, and absorbs collision energy. As shown in FIG. 8B, the column main body 102 includes a front flange 102a facing the roadway, a rear flange 102b having substantially the same width as the front flange 102a, a front flange 102a, and a rear flange 102b. The web 102c to connect is provided, and the horizontal cross section is H-shaped. The rear flange 102b is formed with a curved recess 103 that serves as a starting point for tilting the column main body 102.

In Patent Document 1, since the load concentrates on the curved recess 103 of the rear flange 102b, when the tilting of the column main body 102 progresses, the curved recess 103 of the rear flange 102b is bent and deformed, and the web 102c is localized in the out-of-plane direction. Buckling occurs and the front flange 102a undergoes bending deformation. That is, in the protective fence support 100 of Patent Document 1, the support body 102 is bent and deformed and tilts backward to absorb the collision energy, and further, the web 102c is locally buckled by a predetermined collision load. The front flange 102a is prevented from being broken and the impact force applied to the vehicle is prevented from increasing.
Japanese Patent Laid-Open No. 11-336034

  Since the protective fence support 100 of Patent Document 1 needs to set the local buckling strength of the web 102c so that the collision energy is appropriately absorbed by the bending deformation of the front flange 102a and the rear flange 102b. There is a problem that it is difficult to design and manufacture. That is, in the protective fence post 100 of Patent Document 1, the dimensions of the rear flange 102b and the web 102c are set so that the web 102c is locally buckled in the out-of-plane direction when the support body 102 is tilted. Since it is necessary to adjust the position and curvature of the curved recess 103 that is the starting point of tilting of the main body 102, it is difficult to set the dimensions of each part, and furthermore, high manufacturing accuracy is required to realize the deformation mode assumed in the design. The

  From such a viewpoint, it is an object of the present invention to provide a guard post for protection fences in which the dimensions of each part can be set relatively easily and can be easily manufactured.

The present invention, which was created to solve such a problem, is a support fence post having a pedestal fixed to a foundation constructed on the side of the roadway, and a support column body erected on the pedestal, The column main body includes a front flange facing the roadway, a rear flange disposed behind the front flange, and a web connecting the front flange and the rear flange, and the column is attached to the rear flange. A sectional second moment of the rear flange alone around the centroid axis perpendicular to the front flange without forming a curved recess for locally buckling the main body is the above-mentioned around the centroid axis parallel to the front flange. while the range of 0.05% to 5% of the second moment of the strut body, smaller than the buckling strength of the lateral collapse buckling strength of the rear flange by local buckling of the web By, when the collision load from the road side to the front flange is applied, characterized in that the transverse inclination buckling on the rear flange was made to occur.

  This protective fence post absorbs the collision energy by tilting the post main body backward, and further, the rear flange falls down and buckles with a predetermined collision load, thereby preventing the front flange from breaking. This prevents an increase in impact force applied to the vehicle. According to this protective fence post, since it is not necessary to form a curved recess in the rear flange, it is easy to set the width dimension and thickness dimension of the front flange, rear flange, and web. Further, according to the support fence post, the shape of the support main body is simplified to the extent that the curved concave portion is not formed in the rear flange, so that the manufacture becomes easy.

  In the present invention, the rear flange may be formed narrower than the front flange. If it does in this way, when a collision load acts on a front flange, it will become possible to generate a buckling on a rear flange more certainly. In addition, the rear flange is thinner than the front flange, and the projected area from the front (roadway side) diagonal direction is small, so it is difficult to block the landscape spreading behind the guard fence post when viewed from the roadway side. . That is, the support fence post according to the present invention has excellent transparency from the roadway side, and is easy to harmonize with the landscape.

  The support fence post according to the present invention may include a reinforcing rib that connects the rear surface of the rear flange and the upper surface of the pedestal. This makes it difficult for the rear flange to buckle in the front-rear direction, so that it is possible to more reliably achieve lateral buckling of the rear flange in the left-right direction. Further, since it is possible to prevent load concentration at the boundary between the pedestal and the column main body, it is possible to prevent breakage at the boundary. On the other hand, since the buckling surely occurs in the middle part in the vertical direction of the column main body, it is possible to effectively absorb the collision energy.

  The protective fence support according to the present invention is relatively easy to set in dimensions of each part, and can be easily manufactured.

  FIG. 1 is a perspective view showing a vehicular protective fence G including a protective fence post 2 according to the present embodiment. As shown in this figure, the vehicle guard fence G includes three strips of horizontal members 1, 1, 1 installed along the roadway R, and a plurality of guard fences that support the horizontal members 1, 1,. The support columns 2, 2,... Are provided. In each member, the surface facing the roadway R is referred to as “front surface”, and the opposite surface is referred to as “rear surface”.

  The three strips 1, 1, 1 are arranged in parallel to each other. In addition, in this embodiment, although the guard fence G for vehicles provided with three horizontal members 1,1,1 is illustrated, it is not the meaning which limits the number of items of the horizontal members 1. FIG.

  The horizontal member 1 includes a plurality of hollow beam members 11, 11,... Arranged in the longitudinal direction, and a connecting member 12 disposed inside a boundary portion between the adjacent hollow beam members 11, 11. Has been.

  The hollow beam member 11 has a cylindrical shape and is cut to the same length as the interval between the adjacent protective fence columns 2 and 2. The connecting member 12 is disposed so as to straddle the boundary portion between the adjacent hollow beam members 11 and 11. In addition, in this embodiment, although the case where the external shape of the hollow beam material 11 was circular was illustrated (refer (b) of FIG. 3), it is not limited to this, For example, an ellipse, a shell shape, It can be a rectangle.

  As shown in FIG. 2, the protective fence post 2 includes a pedestal 21 fixed to a reinforced concrete foundation K constructed on the side of the roadway R, a column main body 22 erected on the pedestal 21, And reinforcing ribs 23 joined to the column main body 22 by welding. A plurality of nuts N1 are embedded in the foundation K.

  The pedestal 21 is made of a steel plate having a rectangular shape in top view, and has an insertion hole 21a at a position corresponding to the nut N1 embedded in the foundation K. A bolt B1 screwed into the nut N1 is inserted through the insertion hole 21a. Note that the pedestal 21 is not limited to a rectangular shape and is not shown, but may be a polygonal shape, a circular shape, or the like. Of course, the pedestal 21 may be fixed to an anchor or a steel girder stud bolt embedded in general concrete.

  The column main body 22 includes a front flange 22a facing the roadway R, a rear flange 22b disposed behind the front flange 22a, and a web 22c connecting the front flange 22a and the rear flange 22b. In the embodiment, the upper mounting member 22d disposed from the upper end of the front flange 22a to the upper end of the rear flange 22b, and the middle mounting member 22e and the lower mounting member 22f disposed on the front surface in the center of the front flange 22a. I have.

  The front flange 22a is made of a steel plate, and has a substantially trapezoidal shape as viewed from the front, as shown in FIG. In addition, a pair of left and right bolt insertion holes 221 and 221 are formed in two upper and lower stages at the center in the height direction of the front flange 22a. In the bolt insertion hole 221, a fixing bolt B3 for fixing the middle horizontal member 1 (see FIG. 3B) or a fixing bolt B4 for fixing the lower horizontal member 1 (FIG. 3 ( b) is inserted. As shown in FIG. 3B, the front flange 22a stands from the front end edge of the pedestal 21 and is fixed to the pedestal 21 by welding. The wall thickness of the front flange 22a is constant from the lower end to the upper end. Further, as shown in FIGS. 3C and 3D, the width dimension at the lower end portion of the front flange 22 a is equal to the width dimension at the front end of the base 21.

  The rear flange 22b is made of a steel plate and has a strip shape as shown in FIG. The rear flange 22b is formed narrower than the front flange 22a. The width dimension of the rear flange 22b is desirably 1/2 or less of the width dimension of the lower end portion of the front flange 22a, and more desirably 1/3 or less. The width dimension and thickness of the rear flange 22b are such that the sectional moment of the rear flange 22b alone around the centroid axis b (see FIG. 4B) perpendicular to the front flange 22a is parallel to the front flange 22a. Although it may be set to be 0.05% to 5% of the cross-sectional secondary moment of the entire column main body 22 around the axis a (see FIG. 4B), more preferably 0.7% to 1. It should be set to 0%. In the present embodiment, the width dimension and the thickness of the rear flange 22a are constant from the lower end to the upper end. In the present embodiment, the cross-sectional shape of the rear flange 22a is rectangular. However, the present invention is not limited to this, and may be a polygon other than a rectangle, or a circle or an ellipse. There is no problem. In the present embodiment, as shown in FIG. 3B, the entire rear flange 22b is inclined forward. In this embodiment, the rear flange 22b is disposed from the lower end portion to the upper end portion of the web 22c, and is fixed to the rear end edge of the web 22c by welding. Further, as shown in FIG. 3 (d), the center C2 of the rear flange 22b is located on the vertical plane V including the center C1 of the front flange 22a.

  As shown in FIG. 3B, the web 22c is erected from the upper surface of the pedestal 21 and fixed to the pedestal 21 by welding. As shown in FIG. 3 (d), the web 22c is located on the vertical plane V including the center C1 of the front flange 22a and the center C2 of the rear flange 22b, and is welded to the rear and rear surfaces of the front flange 22a. It is fixed to the front surface of the flange 22b.

  The column main body 22 is designed so that the rear flange 22b starts buckling (lateral buckling) in the left-right direction (longitudinal direction of the horizontal member 1) when the maximum support force is exceeded. When a collision load P (see FIG. 4A) acts on the column main body 22 from the roadway R side, as shown in FIG. 4B, the front side of the column main body 22 with respect to the center axis a (front flange 22a). Side) is tension, and the rear side (rear flange 22b side) is compression, so that the lateral side buckling strength of the rear flange 22b is made smaller than the buckling strength due to local buckling of the web 22c. In this case, the lateral buckling strength of the rear flange 22 b becomes the maximum support force of the column main body 22. The depth dimension W of the column main body 22 is set to have a bending strength that can withstand the bending moment generated when the design horizontal load that simulates the design collision load is applied to the upper end of the column main body 22 statically. To do.

  The upper mounting member 22d shown in FIG. 2 is a member that holds the upper horizontal member 1 (see FIG. 1), and is fixed to the front flange 22a and the web 22c by welding in this embodiment. On the surface on the roadway R side of the upper mounting member 22d, a cylindrical mounting seat is formed along the outer peripheral surface of the upper horizontal member 1. Bolt insertion holes 222 and 222 are formed in the left and right portions of the upper mounting member 22d. A fixing bolt B <b> 2 for fixing the upper horizontal member 1 is inserted into the bolt insertion hole 222.

  The middle mounting member 22e is interposed between the middle horizontal member 1 (see FIG. 1) and the front flange 22a, and on the surface on the roadway R side, the outer periphery of the middle horizontal member 1 is provided. A cylindrical surface mounting seat is formed along the surface. Bolt insertion holes 223 and 223 are formed in the left and right two portions of the middle mounting member 22e. A fixing bolt B3 for fixing the middle horizontal member 1 is inserted through the bolt insertion hole 223.

  Although the lower mounting member 22f is interposed between the lower horizontal member 1 and the front flange 22a, the main configuration is the same as that of the middle mounting member 22e, and thus detailed description thereof is omitted. To do.

  As shown in FIG. 3B, the reinforcing rib 23 is made of a plate material having a triangular shape in side view, and is fixed to the upper surface of the base 21 and the rear surface of the rear flange 22b of the column body 22 by welding. As shown in FIG. 3C, the reinforcing rib 23 is located on the vertical plane V including the center C1 of the front flange 22a and the center C2 of the rear flange 22b. That is, the reinforcing rib 23 is disposed on a vertical plane including the web 22c. The shape of the reinforcing rib 23 is not limited to that shown in the figure, and may be, for example, a rectangular shape, a trapezoidal shape, a polygonal shape, or a sector shape.

  In order to install the guard fence support 2 configured in this way on the upper surface of the foundation K, as shown in FIG. 2, the insertion holes 21a, 21a,... At the four corners of the base 21 are embedded in the foundation N. , N1,... Is placed on the upper surface of the foundation K so as to be positioned directly above, and then the bolt B1 is inserted into the insertion hole 21a of the base 21, and the shaft portion is screwed into the nut N1. .

  Further, as shown in FIG. 3 (b), in order to fix the upper horizontal member 1 to the guard fence post 2, the boundary portion of the hollow beam members 11, 11 (that is, the connecting member 12 is arranged). The upper part mounting member 22d of the column main body 22 and then the bolt insertion holes 222, 222 (see FIG. 2) of the upper stage mounting member 22d and the bolt insertion holes (not shown) of the hollow beam member 11 What is necessary is just to insert the axial part of volt | bolt B2 and screwing the front-end | tip part in the internal thread hole (not shown) formed in the connection member 12.

  Further, in order to fix the middle horizontal member 1 to the protective fence support 2, the boundary portion of the hollow beam members 11, 11 (that is, the portion where the connecting member 12 is disposed) is positioned on the front side of the support main body 22. The intermediate mounting member 22e is interposed between the hollow beam member 11 and the column main body 22, and then the bolt insertion hole 221 of the column main body 22 and the bolt insertion hole 223 of the intermediate column mounting member 22e (see FIG. 2). In addition, the shaft portion of the bolt B3 may be inserted into the bolt insertion hole (not shown) of the hollow beam member 11 and the tip thereof may be screwed into the female screw hole (not shown) of the connecting member 12. The same applies to the case where the lower horizontal member 1 is fixed to the protective fence post 2.

  As shown in FIG. 5A, the protective fence support 2 described above absorbs collision energy by tilting the support body 22 backward, and as shown in FIG. 5B, By causing the rear flange 22b to buckle and buckle with a predetermined collision load, the front flange 22a is prevented from being broken and the impact force applied to the vehicle is prevented from increasing. According to this protective fence post 2, it is not necessary to form a curved recess (see the curved recess 103 shown in FIG. 7A) in the rear flange 22c, so the width of the front flange 22a, the rear flange 22b, and the web 22c. Setting of dimensions and thickness dimensions becomes easy. Further, according to the support fence post 2, the shape of the support body 22 is simplified by the amount that the curved recess is not formed in the rear flange 22 c, so that the manufacture is facilitated.

  In the present embodiment, since the rear flange 22b is formed to be narrower than the front flange 22a, when the collision load is applied to the front flange 22a, the rear flange 22b is more reliably tilted sideways and buckled. It becomes possible. Further, since the rear flange 22b is thinner than the front flange 22a and the projected area from the front diagonal direction is small, the landscape spreading to the rear side of the protective fence post 2 when viewed diagonally forward from the roadway R side. It becomes difficult to block. That is, the protective fence post 2 has excellent transparency from the roadway R side, and is easy to harmonize with the landscape.

  Further, in the present embodiment, the sectional secondary moment around the centroid axis b of the rear flange 22b alone is set to 0.05% to 5% of the sectional secondary moment around the centroid axis a of the column body 22. The lateral buckling of the rear flange 22b is more reliably generated.

  Furthermore, since the protective fence support 2 according to the present embodiment includes the reinforcing rib 23 that connects the rear surface of the rear flange 22b and the upper surface of the pedestal 21, the rear flange 22b is unlikely to buckle in the front-rear direction (weak axis direction). Yes. Therefore, it is possible to more reliably realize lateral buckling of the rear flange 22b in the left-right direction. Moreover, since it is possible to prevent load concentration at the boundary between the base 21 and the column main body 22, it is possible to prevent breakage at the boundary. On the other hand, since buckling surely occurs at the middle part in the vertical direction of the column main body 22, it is possible to effectively absorb the collision energy.

  In the present embodiment, the protective fence support 2 is formed by joining steel plates by welding, but the invention is not limited thereto. The protective fence support 2 may be configured by welding a stainless steel plate or an aluminum alloy plate as a vehicle protective fence by welding. Alternatively, the protective fence support 2 may be a cast product such as cast iron, stainless steel, or aluminum alloy, and the base 21, the support main body 22, the reinforcing rib 23, and the like may be integrally formed. When the protective fence support 2 is a cast product, the width and thickness of the rear flange 22b are secondary cross-sections of the rear flange 22b alone around the centroid shaft b (see FIG. 4B). The moment may be set to be 0.08% to 0.2% of the cross-sectional secondary moment of the column main body 22 around the centroid axis a.

  In this embodiment, the width dimension of the rear flange 22b is not changed from the lower end to the upper end. However, the width dimension is not limited to this, and as shown in the width dimension of the rear flange 22b ′ shown in FIG. Although it may be gradually decreased as it goes, or it is not shown, it may be gradually increased as it goes downward. Although not shown in the drawings, the width dimension of the intermediate portion in the height direction of the rear flange (the portion where lateral buckling is desired to be buckled) may be reduced. That is, the intermediate portion in the height direction of the rear flange may be bundled.

  In the present embodiment, the thickness of the rear flange 22b is unchanged from the lower end to the upper end. However, the thickness is not limited to this, and although not illustrated, the thickness may be gradually reduced toward the bottom. You may increase gradually as it goes downward. Moreover, although illustration is abbreviate | omitted, you may reduce the thickness in the intermediate part (part which wants to carry out lateral buckling) of the height direction of a rear surface flange.

Regarding the protective fence post 2 according to the above-described embodiment, the relationship between the load and the amount of displacement when a horizontal load simulating a collision load is applied statically to the upper end of the post body 22 (manufactured by welding). Is shown in FIG.
The material of each element (the pedestal 21, the column main body 22, and the reinforcing rib 23) constituting the protective fence column 2 is SS400. The height of the column main body 22 is 750 mm, the width dimension at the lower end of the front flange 22a is 140 mm, the width dimension at the upper end is 93 mm, and the wall thickness is 9 mm. The rear flange 22b has a width of 38 mm, a wall thickness of 9 mm, and the web 22c has a wall thickness of 6 mm. The thickness of the reinforcing rib 23 is 12 mm.

  As shown in FIG. 7, the rear flange 22b was buckled and buckled at 31.6 kN, but there was no sudden drop in load until the amount of displacement of the upper end of the column main body 22 reached 30 cm. Since the displacement at the upper end of the column main body 22 reaches 30 cm and the load at that time is about 25 kN, the protective fence column 2 has characteristics that can sufficiently withstand the collision load at the time of vehicle contact / collision. I understand.

It is a perspective view of the guard fence for vehicles provided with the support | pillar for guard fences concerning this embodiment. It is a disassembled perspective view of the support fence post according to the present embodiment. It is a figure which shows the support | pillar for protection fences concerning this embodiment, Comprising: (a) is a front view, (b) is a side view, (c) is a rear view, (d) is a X1-X1 line cross section of (a). FIG. FIG. 5B is a side view for explaining the compressive force generated in the rear flange when a horizontal load simulating a collision load is applied, and FIG. 5B is a cross-sectional view for explaining a method for designing the column main body. (A) And (b) is a perspective view which shows the condition where the side flange fell down and buckled generate | occur | produced. It is a rear view which shows the modification of the support | pillar for protection fences concerning this embodiment. It is a graph which shows the relationship between the load and the amount of displacement when applying the horizontal load which simulated the collision load statically to the upper end part of the support | pillar for protection fences. It is a figure which shows the support pillar for the conventional protection fence, Comprising: (a) is a side view, (b) is the X2-X2 sectional view taken on the line of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Horizontal member 2 Guard fence post 21 Base 22 Post body 22a Front flange 22b Rear flange 22c Web 23 Reinforcement ribs a and b

Claims (3)

A pedestal fixed to the foundation built beside the roadway,
A support fence post having a support body standing on the pedestal,
The column main body includes a front flange facing the roadway, a rear flange disposed behind the front flange, and a web connecting the front flange and the rear flange, and the column is attached to the rear flange. Without forming a curved recess to locally buckle the body,
And the sectional secondary moment of the rear flange unit around the centroid axis perpendicular to the front flange is 0.05% to 5% of the sectional secondary moment of the column main body around the centroid axis parallel to the front flange. As well as
Is made smaller than the buckling strength by falling down laterally buckling local buckling of the web of the rear flange, when the collision load from the road side to the front flange is applied, the lateral falling locus to the rear surface flange A protective fence post characterized by bending.   The guard fence support according to claim 1, wherein the rear flange is formed narrower than the front flange. Fences upright according to claim 1 or claim 2, further comprising a reinforcing rib connecting the upper surface of the the rear surface of the rear flange pedestal.

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