JP5417152B2 - Guard post - Google Patents

Description

  The present invention relates to a protective fence post used for a protective fence for roads, bridges, and the like.

  Conventionally, protective fences for roads, bridges, etc. have a structure that can ensure the safety of passengers etc. while absorbing the impact load at the time of vehicle collision and minimizing the damage of the accident as much as possible. It is required to make a structure that meets such a requirement also for the protective fence post used for the protective fence.

  For example, as a performance required for a rectangular column for a recent protective fence, when a load test as described below is performed, the maximum load resistance is 55 kN to 60 kN, and the displacement amount is 300 mm. It is required that the impact load can be absorbed without breaking.

  To satisfy such required performance, simply adjusting the thickness, material, etc. of the guard fence post to increase the rigidity, the early stage of the welded joint between the base plate constituting the guard fence and the tube body It is difficult to satisfy the required performance. For this reason, what devised variously about the structure of the support | pillar for protection fences so that required performance can be satisfied is proposed (for example, refer patent document 1, 2).

  In Patent Document 1, as shown in FIG. 16, a plate-like center stiffener 171 parallel to a horizontal member such as a beam, pipe, or wire cable is joined to the upper surface of the base plate 111 by welding, and the lower end portion of the tubular body 121 There is described a protective fence column 101 in which a center stiffener 171 is fitted in a notch formed in 121a, and the notch of the tubular body 121 and the center stiffener 171 are joined by welding. In this protective fence post 101, the required performance as described above can be obtained by adjusting the dimensions such as the thickness and height of the center stiffener 171 and the gap between the center stiffener 171 and the lower end 121d of the tubular body 121. It is structured.

  In Patent Document 2, as shown in FIG. 17, a guard fence column 102 in which a pair of vertical slits 173 is formed at the lower end portion 121 a of the pipe body 121 at intervals in the pipe circumferential direction and long in the pipe axis direction. Is described. In this protective fence post 102, the rear surface 121f of the tubular body 121 sandwiched by the pair of longitudinal slits 173 is compressed in the tubular axial direction so as to enter the tubular body 121 from the initial deformation stage to the final deformation stage. The side surface 121c of the tube body 121 is configured to be bent and plastically deformed while being compressed in the tube axis direction so as to protrude outside the tube body 121. As a result, this protective fence post 102 can exhibit impact load absorption performance while preventing breakage of the weld joint 122, and the slit width and slit height of the pair of vertical slits 173. By adjusting the dimensions, etc., the above-described required performance can be obtained.

  Further, as shown in FIG. 18, Patent Document 2 describes a structure in which a reinforcing plate 175 is joined to a position facing the vertical slit 173 on the inner surface of the lower end portion 121 a of the tubular body 121. As a result, it is possible to further improve the effect of preventing breakage at the weld joint 122 where breakage is likely to occur while improving the maximum load capacity during deformation.

Japanese Patent Laid-Open No. 11-117245 (refer to claim 1 etc.) Japanese Patent Laying-Open No. 2008-202393 (see claims 1 and 12)

  FIG. 10 shows a load-displacement curve when the following load test is performed on the protective fence columns 101 and 102 described in Patent Documents 1 and 2.

  In this load test, a steel pipe having a rectangular cross section with a material of STK400, a cross-sectional dimension of 125 mm × 125 mm × 6 mm, and a height of 840 mm is used as the tube body 121, and a material of SS400 is used as the base plate 111. A steel plate having dimensions of 300 mm × 300 mm × 28 mm was used. Comparative Example 1 is a support fence post 101 having a structure as shown in FIG. 16 described in Patent Document 1, and as the center stiffener 171, the material is SS400, and the plate thickness × height is 22 mm × 150 mm. The thing with the clearance gap between the lower end 121d of the tubular body 121 is 5 mm was used. Comparative Example 2 is a protective fence post 102 having a structure as shown in FIGS. 17 and 18 described in Patent Document 2, the slit width × slit height of the vertical slit 173 is 5 mm × 60 mm, and the reinforcing plate 175 The width × height × thickness of 90 mm × 50 mm × 9 mm was used.

  In this load test, a displacement meter is installed on the front surface of the tube body 121 located 760 mm above the bottom surface of the base plate 111, and a static load is applied to a position 760 mm above the bottom surface of the tube body 121. The load-displacement curve was obtained by measuring the displacement (mm) with respect to the load (kN).

  In Comparative Example 1, a maximum load capacity was 59.78 kN, and in Comparative Example 2, a load-displacement curve with a maximum load capacity of 58.2 kN was obtained.

  As shown in FIG. 10, in the protective fence post 101 described in Patent Document 1, after the stiffener plate 171 yields and deforms, the lower end 121 d of the tubular body 121 comes into contact with the base plate 111 and then the tubular body 121 yields. The maximum load capacity can be obtained for the first time. However, it is preferable that the protective fence support has a structure that allows a vehicle that collides with the protective fence to be guided in a safe direction along the protective fence at an early stage. Therefore, it has been desired to have a structure capable of obtaining a maximum load capacity.

  Further, the protective fence post 101 described in Patent Document 1 requires a center stiffener 171 in addition to the tube body 121, and accordingly, an increase in welding work time for production, an increase in production cost due to welding, and weight. Problems such as deterioration in workability due to the increase and increase in material costs have occurred.

  Further, in the protective fence post 102 described in Patent Document 2, in order to improve the maximum load resistance and prevent the welded joint 122 from being broken, it is possible to adopt a structure in which the reinforcing plate 175 is joined. When the reinforcing plate 175 is joined, problems such as deterioration in workability due to weight increase and increase in material cost occur. Further, in order to join the reinforcing plate 175 to the inner surface of the pipe body 121, a welding operation with a closed cross-section is required, which is difficult compared to normal welding, and increases the working time for manufacturing. The manufacturing cost by welding will be increased. Further, when welding the reinforcing plate 175, it is particularly difficult to weld the upper portion of the reinforcing plate 175, and it is considered that the welding of the upper portion of the reinforcing plate 175 must be omitted. In this case, the pickling treatment performed as a pretreatment when the protective fence support 102 is subjected to the galvanizing treatment causes the pickling solution to enter between the reinforcing plate 175 and the pipe body 121 and cause corrosion. End up. In view of these points, there has been a demand for a protective fence post having a structure that can obtain deformation characteristics equal to or higher than those obtained when the reinforcing plate 175 is joined without joining the reinforcing plate 175.

  Further, in the protective fence post 102 described in Patent Document 2, as shown in FIG. 17B, when the rear surface 121f and the side surface 121c of the tube body 121 are bent while being compressed in the tube axis direction and plastically deformed. As a result of the deformation of the rear surface 121f and the side surface 121c of the tube body 121, the load resistance at the final stage of deformation is relatively low. As the protective fence post, it is preferable to further improve the load resistance at the final stage of deformation in the direction W shown in FIG. 10 while satisfying each required performance as described above. It was desired.

  Accordingly, the present invention has been devised in view of the above-described problems, and the object of the present invention is to provide a maximum load capacity equal to or greater than that when a reinforcing plate is joined without a reinforcing plate. Provided is a protective fence post which can be obtained at an early stage of deformation with a small amount of displacement, can further improve load resistance at the final stage of deformation, and can further reduce the number of members used. It is in.

  In order to solve the above-described problems, the inventor has invented the following protective fence support after intensive studies.

  A protective fence support according to a first aspect of the present invention includes a base plate that is fixed to a foundation and a tube that is erected from the base plate, and absorbs an impact load applied to the tube by plastic deformation of the tube. Possible struts for guard fences, comprising a set of notches formed at intervals in the tube axis direction at the lower end of the tube opposite to the side receiving the impact load, The one set of notch holes is formed in two sets at intervals in the pipe circumferential direction of the pipe body.

  The protective fence support according to a second aspect of the present invention is the protective fence support according to the first aspect, wherein the pair of cutout holes are formed on the uppermost end side of the tubular body with an interval above the base plate. It is characterized by being.

  A protective fence support according to a third aspect of the present invention is the first or second aspect, wherein the tubular body is formed in a square cross section, and the pair of cutout holes are formed in corner portions of the tubular body. It is characterized by being.

  The protective fence support according to a fourth aspect of the present invention is characterized in that, in the invention according to any one of the first to third aspects, the pair of cutout holes is a through-hole penetrating the tubular body.

  The protective fence support according to a fifth aspect of the present invention is the protection fence according to any one of the first to third aspects of the present invention, wherein the one set of cutout holes is formed on one or both of the outer surface and the inner surface of the tubular body. It is the hollow which has the formed bottom face, It is characterized by the above-mentioned.

  According to the first to fifth aspects of the invention, it is possible to easily obtain a predetermined maximum load capacity even at the initial stage of deformation with a relatively small amount of column displacement. In addition, since two sets of cutout holes are provided, it is possible to adjust the maximum load resistance at the initial stage of deformation, and even when there is no reinforcing plate, the maximum withstand value equal to or higher than that when the reinforcing plate is joined. A load can be obtained. Further, since the remaining portion is provided between the pair of cutout holes, it is possible to further improve the load resistance at the final stage of deformation compared to the conventional protective fence post 102. In addition, these effects can be achieved without using special members, and the number of used members can be reduced. As a result, the workability is improved by weight reduction and the material cost is reduced. Thus, it is possible to solve the peculiar problems that occur when the conventional reinforcing plates are joined.

(A) is a top view which shows an example of the protection fence in which the support | pillar for protection fences concerning 1st Embodiment is used, (b) is the front view. It is side surface sectional drawing which shows an example of the protection fence in which the support | pillar for protection fences concerning 1st Embodiment is used. It is a perspective view which shows the structure of the support | pillar for protection fences concerning 1st Embodiment. (A) is the front view which looked at the support | pillar for protection fences concerning 1st Embodiment from the front side, (b) is the top view, (c) is the side view, (d) is the side It is a rear view, (e) is an A arrow view of (b). (A) is a plane sectional view of the pillar for protection fence concerning a 1st embodiment, and (b) is a partial notch enlarged view of Drawing 4 (d). It is the figure which showed typically the stress distribution applied to the lower end part of a tubular body in a deformation | transformation initial stage. It is the figure which showed typically the deformation | transformation state of the lower end part of a tubular body after the deformation | transformation initial stage with the stress distribution. It is the figure which showed typically the deformation | transformation state in the final stage of a deformation | transformation in which the deformation | transformation advanced further than FIG. 7 with the stress distribution. It is the figure which looked at the deformation | transformation state of the lower end part of the tubular body in the middle of a deformation | transformation from the different angle. It is a figure which shows the load-displacement curve at the time of performing a load load test with respect to the support | pillar for protection fences of the structure of an invention example, the comparative example 1, and the comparative example 2. FIG. (A) is the figure which looked at the structure of the guard post for guards concerning 2nd Embodiment from the same direction as A arrow of FIG.3 (b), (b) is the guard post for guards concerning 3rd Embodiment. It is the figure which looked at the structure of from the same direction as A arrow of FIG.3 (b). (A) is an expansion perspective view which shows the structure of the support | pillar for protection fences concerning 4th Embodiment, (b) is an expansion perspective view which shows the structure of the support | pillar for protection fences concerning 5th Embodiment. (A) is the figure which looked at the structure of the support | pillar for protection fences concerning 6th Embodiment from the same direction as A arrow of FIG.3 (b), (b) is the BB sectional drawing of (a). (C) is the figure which looked at the structure of the support | pillar 1 for guard fences concerning 7th Embodiment from the same direction as A arrow of FIG.3 (b), (d) is C- of (c). FIG. It is a perspective view which shows the structure of the support | pillar for guard fences concerning 8th Embodiment. (A) is the front view which looked at the support | pillar for protection fences concerning 8th Embodiment from the front side, (b) is the top view, (c) is the side view, (d) is the side It is a rear view. It is a perspective view which shows the structure of the support | pillar for protection fences described in patent document 1. FIG. (A) is a perspective view which shows the structure of the support | pillar for protection fences of patent document 2, (b) is a perspective view which shows the deformation | transformation state. (A) is side sectional drawing which shows the state which joined the reinforcement board with respect to the support | pillar for protection fences of patent document 2, (b) is the top view.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for implementing a guard fence post to which the present invention is applied will be described in detail with reference to the drawings.

  First, the structure of the support fence post 1 according to the first embodiment will be described.

  Fig.1 (a) is a top view which shows an example of the protection fence 3 in which the support | pillar 1 for protection fences concerning 1st Embodiment is used, FIG.1 (b) is the front view, FIG. 2 is the side surface. It is sectional drawing.

  The protective fence 3 includes a plurality of protective fence posts 1 that are installed upright with respect to a foundation 7 made of concrete or the like, and a horizontal member 5 that is installed on the multiple protective fence supports 1. I have. The protective fence 3 is installed with respect to a road, a bridge, etc., for example. When the guard fence 3 is installed on the road, it is installed along the roadside or the median strip, and when it is installed on the bridge, the side edge of the main girder in the direction perpendicular to the bridge axis. It is installed along. In the following description, the case where the protective fence 3 is installed along the road side will be described as an example, and the road side of the protective fence column 1 will be described as the front side, and the opposite side to the road side will be the back side.

  In the first embodiment, the horizontal member 5 is composed of a guard rail beam. However, the horizontal member 5 is composed of a guard pipe, a guard cable wire rope, and the like. The horizontal member 5 is attached to the front side of the tubular body 21 in order to transmit a collision load caused by a collision with a vehicle or the like to the protective fence support 1.

  FIG. 3 is a perspective view showing a configuration of the guard fence support 1 according to the first embodiment. FIG. 4A is a front view of the guard fence support 1 according to the first embodiment as viewed from the front side thereof, FIG. 4B is a plan view thereof, and FIG. 4C is a side view thereof. FIG. 4 (d) is a rear view thereof, and FIG. 4 (e) is a view taken along arrow A in FIG. 4 (b). FIG. 5A is a plan sectional view of the protective fence post 1 according to the first embodiment, and FIG. 5B is an enlarged partial cutaway view of FIG.

  The guard fence post 1 includes a base plate 11 fixed to the foundation 7 and a tube body 21 standing from the base plate 11. The protective fence support 1 functions as a support that can absorb the impact load applied to the tubular body 21 due to a collision between the vehicle or the like and the horizontal member 5 or the tubular body 21 by plastic deformation of the tubular body 21. Is. The base plate 11 and the pipe body 21 of the support fence post 1 are made of, for example, a ferrous metal such as steel or a non-ferrous metal such as aluminum.

  The base plate 11 is formed at the pillar holes 13 into which the tubular body 21 formed at the center thereof is inserted, and at the four corners thereof, and anchor bolts 61 and the like for fixing the base plate 11 to the foundation 7 are inserted. And a fixing bolt hole 17.

  The base plate 11 is formed to have a rectangular shape in plan view in the first embodiment, but the shape is not limited to this, and is formed to have a circular shape, a polygonal shape, or the like in plan view. May be.

  The tube body 21 is formed in a square cross section in the first embodiment. The tube body 21 has its lower end 21a inserted into the support hole 13 of the base plate 11, welds the side surface 21c and the upper surface 11a of the base plate 11, and further lowers the lower end 21d and the support hole of the base plate 11. 13 is fixed to the base plate 11 by welding.

  The tube body 21 has a bracket bolt hole 23 formed at the upper end 21b. A bracket 65 is attached to the upper end portion 21 b of the tubular body 21 by a bolt 63 inserted through the bracket bolt hole 23, and the horizontal member 5 is attached by a bolt 63 or the like through the bracket 65. In addition, if the structure for attaching the horizontal member 5 with respect to the pipe body 21 is a well-known structure, it will not specifically limit.

  Here, the tube body 21 of the protective fence post 1 according to the present invention further includes a pair of cutout holes 31 formed at intervals in the tube axis direction at the lower end portion 21a on the back side. ing. The pair of cutout holes 31 are formed in two sets at intervals in the tube circumferential direction of the tube body 21. In the first embodiment, a total of four cutout holes 31 are formed for each tube body 21. A remaining portion 33 in which the tubular body 21 remains is provided between the cutout holes 31 constituting the pair of cutout holes 31. Note that three or more sets of the cutout holes 31 may be formed at intervals in the tube axis direction of the tube body 21.

  The two pairs of cutout holes 31 are formed at positions opposite to the side receiving the impact load applied to the tubular body 21 due to a collision between the vehicle or the like and the horizontal member 5 or the tubular body 21. It is formed as follows. In the first embodiment, since the side receiving the impact load is the front side of the tube body 21, the two sets of cutout holes 31 are formed on the back side opposite to the front side of the tube body 21. . More specifically, in the first embodiment, the two sets of cutout holes 31 are formed in the corner portion 21e of the tube body 21 formed in a square cross section.

  The two sets of cutout holes 31 are formed so that adjacent ones of the cutout holes 31 constituting each set in the pipe circumferential direction are positioned at substantially the same height with respect to the base plate 11. In addition, in the first embodiment, the two sets of the cutout holes 31 are formed on the uppermost side 11 a of the base plate 11 with a slight gap therebetween at the lowermost end side of the tube body 21. Thereby, the cross-sectional defect | deletion will be lose | eliminated in the pipe circumferential direction at the pipe body 21 by the welding junction part 22 of the pipe body 21 and the baseplate 11. The two sets of cutout holes 31 may be formed so that the one located on the lowermost end side of the tube body 21 is located on the same plane as the upper surface 11 a of the base plate 11.

  The two sets of cutout holes 31 are formed in a circular shape in the first embodiment. The two sets of cutout holes 31 are not particularly limited in shape as long as the intended effect of the present invention can be obtained, and in addition to a rectangular shape, a polygonal shape, and an elliptical shape as in the embodiments described later. It may be formed in an indefinite shape or the like. In addition, in the first embodiment, the two sets of cutout holes 31 are configured as through holes penetrating the tube body 21, but any one of the outer surface and the inner surface of the tube body 21 as in the embodiment described later. You may be comprised as a groove | channel which has the bottom face formed in either or both.

  In the guard fence support 1 according to the first embodiment, the reinforcing plate is not joined to the inner surface of the lower end portion 21a of the tubular body 21.

  Next, the effect of the protective fence support 1 according to the present invention will be described.

  A vehicle body 21 collides with the horizontal member 5 of the protective fence 3 or the protective fence support 1 and the tubular body 21 as shown in FIG. 4B against the tubular body 21 of the protective fence support 1. Consider the case where a collision load is applied in the direction P1 from the front side to the back side.

  FIG. 6 is a diagram schematically showing a stress distribution applied to the lower end portion 21a of the tubular body 21 in the initial stage of deformation.

  In this case, in the initial stage of deformation until plastic deformation starts at the lower end portion 21a of the tube body 21, the compressive stress P1 in the tube axis direction is loaded on the back side of the lower end portion 21a of the tube body 21, and on the front side thereof. A tensile stress in the tube axis direction is applied. At this time, as shown in FIG. 6, the cutout hole 31 of the pipe body 21 is deformed so that the side edges 31a on both sides in the pipe circumferential direction are spread apart from each other due to the compressive stress in the pipe axis direction applied thereto. As a result, tensile stress P2 in the pipe circumferential direction is applied to both sides of the notch hole 31 in the pipe circumferential direction.

  Here, the stress applied to the part S1 surrounded by the two sets of cutout holes 31 of the tubular body 21 as shown in FIG. 6 will be considered. First, the tensile stress P2 in the pipe circumferential direction as described above is applied to the part S1. In addition, a substantially uniform compressive stress P1 in the tube axis direction is applied to the portion S1 over the tube circumferential direction. In addition, a bending stress that deforms so as to be recessed inside the tube body 21 is applied to the portion S1. When the compressive stress P1 in the tube axis direction, the tensile stress P2 in the tube circumferential direction, and the bending stress are exceeded to some extent, plastic deformation starts to buckle so that the portion S1 is recessed inward.

  Incidentally, also in the part S2 located on both sides in the pipe circumferential direction with respect to the part S1 surrounded by the two sets of cutout holes 31 of the pipe body 21 as shown in FIG. The tensile stress P2 is applied. Further, the compressive stress P1 in the tube axis direction is applied to the portion S2 so as to become smaller from the portion S1 in the tube circumferential direction.

  Here, in the present invention, a remaining portion 33 is provided between the cutout holes 31 constituting the set of cutout holes 31. For this reason, it resists by this residual part 33 with respect to the tensile stress P2 of the pipe circumferential direction loaded with respect to site | part S1 and site | part S2 enclosed by the two sets of notch holes 31 of the above-mentioned tubular body 21. It becomes possible. Thereby, compared with the case where the longitudinal slit 173 as shown in FIG. 17 having the slit height of the same length as the total length of the pair of cutout holes 31 as shown in FIG. The buckling strength can be improved, and the maximum load capacity at the initial stage of deformation can be improved.

  FIG. 7 is a diagram schematically showing the deformation state of the lower end portion 21a of the tube body 21 along with its stress distribution after the initial stage of deformation, and FIG. 8 is a final stage of deformation where the deformation has advanced further than FIG. It is the figure which showed the deformation | transformation state typically with the stress distribution.

  After the initial stage of deformation, as shown in FIG. 7, the compressive stress P1 in the tube axis direction, the tensile stress P2 in the tube circumferential direction, and the bending stress are continuously applied to the portions S1 and S2 of the tube body 21. As a result, as shown in FIG. 7 and FIG. 8, the part S <b> 2 located on both sides in the pipe circumferential direction with respect to this part S <b> 1 is outside so that the part S <b> 1 surrounded by the two sets of cutout holes 31 is recessed inside. The plastic deformation that becomes convex is progressed.

  Here, in the present invention, a remaining portion 33 is provided between the cutout holes 31 constituting the set of cutout holes 31. The remaining portion 33 is provided so as to connect a portion S1 that deforms so as to be recessed inside the tube body 21 and a portion S2 that deforms so as to protrude outwardly from the tube body 21. For this reason, the remaining portion 33 is loaded with a load in a direction to be deformed so as to be recessed toward the inside of the tubular body 21 and a load in a direction to be deformed so as to be convex toward the outside of the tubular body 21. As a result, the deformation amount of the remaining portion 33 becomes smaller than the deformation amount of the part S1 and the part S2. This is a deformation that is recessed inside the part S1 surrounded by the two sets of cutout holes 31, and a deformation that is convex outward of the part S2 located on both sides in the circumferential direction of the part S1. On the other hand, it means that the remaining portion 33 resists, and as a result, the load resistance at the final stage of deformation after the plastic deformation starts is improved.

  In addition, in 1st Embodiment, as shown in FIG. 9, site | part S3, S4 located in the both sides of a pipe-axis direction with respect to site | part S1 enclosed by two sets of notch holes 31 is a cross section in a pipe circumferential direction. There are no defects or the base plate 11 is restrained by welding. For this reason, as a result of the deformation amount being smaller than that of the part S1, the part S1 surrounded by the two sets of the cutout holes 31 is plastically deformed so as to be recessed more inwardly than the other parts S3 and S4. This is because when the impact load is applied to the tube body 21, the largest compressive stress is applied to the part S1 surrounded by the two sets of cutout holes 31, and the bending deformation starts from the part S1. Means that will occur. At this time, the tensile stress in the tube axis direction applied to the front surface side of the tube body 21 is most heavily applied at the portion S5 closest to the portion S1 surrounded by the two sets of cutout holes 31. Become. As a result, it is possible to plastically deform above the welded joint portion 22 between the tube body 21 and the base plate 11 and to absorb stress above the welded joint portion 22, thereby preventing breakage at the welded joint portion 22. It becomes possible.

  FIG. 10 shows a load-displacement curve when the above-described load test is performed on the protective fence support 1 having the structure shown in FIG. As the pipe body 21, the same condition as in Comparative Examples 1 and 2 as described above was used. As shown in FIG. 3, two sets of circular through holes having a diameter of 30 mm are formed in the tube body 21, and the lower notch hole 31 has a center plate at the center position. The upper notch hole 31 is spaced by a distance of 40 mm from the center position of the lower notch hole 31. The reinforcing plate 175 is not joined to the inner surface of the lower end portion 21 a of the tube body 21. The test conditions in this load test are as described above.

  As a result, in the inventive example, a load-displacement curve having a maximum load resistance of 58.51 kN as shown in the drawing was obtained. In Comparative Example 2, the maximum load capacity is 58.2 kN as described above. Thus, in the inventive example, the reinforcing plate 175 is not used as in the comparative example 2, and the total length in the tube axis direction of the pair of cutout holes 31 is approximately the same as the slit height in the comparative example 2. However, the maximum load capacity comparable to that of Comparative Example 2 is obtained.

  Further, in the inventive example, the reinforcing plate 175 is not used as in the comparative example 2, and the total length in the tube axis direction of the pair of cutout holes 31 is approximately the same as the slit height in the comparative example 2. Nevertheless, the load resistance at the end stage of deformation superior to that of Comparative Example 2 is obtained.

  As described above, according to the present invention, it is possible to easily obtain a predetermined maximum load capacity even in the initial stage of deformation with a relatively small amount of column displacement. Further, according to the present invention, since the two sets of the cutout holes 31 are provided, the maximum load capacity at the initial stage of deformation can be adjusted as will be described later, and even if the reinforcing plate 175 is not provided, the reinforcement is performed. It becomes possible to obtain a maximum load capacity equal to or higher than that when the plates 175 are joined. Further, according to the present invention, since the remaining portion 33 is provided between the pair of cutout holes 31, it is possible to further improve the load resistance in the final stage of deformation compared to the conventional protective fence post 102. It becomes. In addition, according to the present invention, it is possible to exert these effects without using a special member, it is possible to suppress the number of members used, as a result, improvement in workability by weight reduction and In addition to the reduction in material cost, it is possible to solve problems peculiar to the case where the conventional reinforcing plate 175 is joined.

  Here, as described above, as the protective fence support 1, when the load load test as described above is performed, the maximum load capacity can be 55 kN to 60 kN and a predetermined maximum load capacity, or a displacement of 300 mm. There is a demand for not breaking until a predetermined amount of displacement is obtained. In order to satisfy such required performance, for example, the dimensions and positions of the cutout holes 31 may be adjusted in consideration of the characteristics with respect to the dimensions and positions of the cutout holes 31 as described below.

  For example, as shown in FIG. 5, when the interval L1 in the tube axis direction of the pair of cutout holes 31 is too small, the cross-sectional area of the remaining portion 33 between the pair of cutout holes 31 becomes small and is loaded on the remaining portion 33. As a result, the remaining portion 33 may be broken by the stress, and as a result, the load resistance during the final stage of deformation may be reduced. In addition, when the tube axis direction interval L1 is too large, the inclination angle with respect to the vertical surface due to the bending of the tube body 21 becomes too large, and the height of the protection fence 3 is lowered when the tube body 21 is largely deformed. As a result, there is a risk that the performance of the protective fence such as riding on a large vehicle or breaking through the vehicle may be reduced.

  In addition, when the tube axis direction distance L2 from the upper surface 11a of the base plate 11 to the lower cutout hole 31 is too large, the inclination angle with respect to the vertical surface due to the bending of the tube body 21 becomes too large. There is a risk of deteriorating the protective fence performance such as breaking through. Further, the part S1 surrounded by the two sets of cutout holes 31 resists the impact load applied to the tube body 21 while being deformed. The bending moment at the time of deformation of the part S1 is considered. The degree of resistance increases as the distance from the base plate 11 of the part S1, that is, the increase in the tube axis direction interval L2, and decreases as the tube axis direction interval L2 decreases. For this reason, it is possible to adjust the maximum load resistance when an impact load is applied to the tube body 21 by adjusting the tube axis direction interval L2.

  Moreover, when the notch hole 31 is too large, the cross-sectional defect | deletion of the tubular body 21 will become large, and the reduction | decrease of a maximum load capacity will be caused. If the cutout hole 31 is too small, the maximum load capacity can be increased. However, the upper edge 31b and the lower edge 31c of the cutout hole 31 come into contact with each other before being displaced to a predetermined displacement amount, and the deformation due to the cutout hole 31 occurs. Is no longer promoted, and tensile stress concentrates on the weld joint 22 between the front surface side of the lower end 21a of the tube body 21 and the base plate 11, and as a result, the weld joint 22 may be broken. is there.

  In consideration of these premises, by adjusting the size and position of the notch hole 31, the protective fence column has a performance that does not break until it reaches a predetermined maximum load resistance or reaches a predetermined displacement. 1 can be obtained.

  Next, the structure of the support fence post 1 according to the second and third embodiments will be described. In addition, about the component same as the component mentioned above, the description below is abbreviate | omitted by attaching | subjecting the same code | symbol.

  Fig.11 (a) is the figure which looked at the structure of the support | pillar 1 for guard fences concerning 2nd Embodiment from the same direction as A arrow of FIG.3 (b), FIG.11 (b) is 3rd Embodiment. It is the figure which looked at the structure of the support | pillar 1 for such a guard fence from the same direction as A arrow of FIG.3 (b).

  The guard fence support 1 according to the second embodiment has two sets of cutout holes 31 formed in a rectangular shape, and the guard fence support 1 according to the third embodiment has two sets of cutout holes 31 having a hexagonal shape. Is formed. As described above, the two sets of the cutout holes 31 are not particularly limited with respect to the shape within a range in which the intended effect of the present invention is obtained, but are formed in a circular shape as in the first embodiment. This is preferable because it can be easily manufactured and the deformation behavior when an impact load is applied to the tube body 21 is stabilized.

  Next, the structure of the support fence post 1 according to the fourth and fifth embodiments will be described.

  FIG. 12A is a partially enlarged perspective view showing the structure of the guard fence post 1 according to the fourth embodiment, and FIG. 12B is a partially enlarged perspective view showing the structure of the guard fence post 1 according to the fifth embodiment. FIG.

  In the guard fence post 1 according to the fourth embodiment, two sets of cutout holes 31 are formed on the side surface 21c of the tubular body 21 formed in a square cross section and in a portion near the back surface 21f. In the guard fence post 1 according to the embodiment, two sets of cutout holes 31 are formed on the back surface 21f of the tubular body 21 formed in a square cross section and in a portion near the side surface 21c. Thus, as long as the two sets of cutout holes 31 are positions on the opposite side to the side receiving the impact load applied to the tube body 21, the positions where the two cutout holes 31 are formed are not particularly limited. However, as in the first embodiment, the two sets of notches 31 are formed in the corner 21e of the tubular body 21 formed in a square cross section so that an impact load is applied to the tubular body 21. This is preferable because the deformation behavior is stable.

  Next, the structure of the guard fence support 1 according to the sixth and seventh embodiments will be described.

  Fig.13 (a) is the figure which looked at the structure of the support | pillar 1 for guard fences concerning 6th Embodiment from the same direction as A arrow of FIG.3 (b), FIG.13 (b) is FIG.13 (a). Fig. 13 (c) is a view of the structure of the protective fence post 1 according to the seventh embodiment as viewed from the same direction as the arrow A in Fig. 3 (b). 13 (d) is a cross-sectional view taken along the line CC of FIG. 13 (c).

  The guard fence support 1 according to the sixth embodiment is configured such that two sets of cutout holes 31 have a bottom surface 31 d formed on the outer surface of the tubular body 21. The protective fence support 1 according to the seventh embodiment is configured such that two sets of cutout holes 31 have a bottom surface 31 d formed on the inner surface of the tube body 21. The thickness of the portion provided with the depression is adjusted so as to be easily broken when the tube body 21 is deformed.

  Also in the case of the sixth and seventh embodiments, the deformation behavior as described above can be obtained, and the intended effect of the present invention can be obtained. In the case of the sixth and seventh embodiments, the intrusion of rainwater or the like into the tube body 21 can be suppressed, and the occurrence of corrosion can be suppressed accordingly. When the cutout hole 31 is configured as a recess having a bottom surface 31 d, the recess may be formed on both the outer surface and the inner surface of the tube body 21.

  Next, the structure of the guard fence support 1 according to the eighth embodiment will be described.

  FIG. 14 is a perspective view showing the configuration of the guard fence support 1 according to the eighth embodiment. Moreover, Fig.15 (a) is the front view which looked at the support | pillar for protection fences concerning 8th Embodiment from the front side, (b) is the top view, (c) is the side view, d) is a rear view thereof.

  As for the protective fence support | pillar 1 which concerns on 8th Embodiment, the tubular body 21 is formed in the circular cross section. As described above, the tubular body 21 is not particularly limited in its cross-sectional shape, but the impact load is applied to the tubular body 21 when the tubular body 21 is formed in a square cross section as in the first embodiment. In this case, the deformation behavior is preferable.

  As mentioned above, although the example of embodiment of this invention was demonstrated in detail, all the embodiment mentioned above showed only the example of actualization in implementing this invention, and these are the technical aspects of this invention. The range should not be construed as limiting.

1: Guard fence post 3: Guard fence 5: Horizontal member 7: Foundation 11: Base plate 11a: Upper surface 13: Post hole 17: Fixing bolt hole 21: Tube 21a: Lower end 21b: Upper end 21c: Side 21d: Lower end 21e: Corner portion 21f: Back surface 22: Welded joint 23: Bracket bolt hole 31: Notch hole 31a: Side edge 31b: Upper edge 31c: Lower edge 31d: Bottom surface 33: Remaining portion 61: Anchor bolt 63 : Bolt 65: Bracket 171: Center stiffener 173: Vertical slit 175: Reinforcing plate

Claims (5)

A support fence post comprising a base plate fixed to a foundation, and a pipe standing from the base plate, and capable of absorbing an impact load applied to the pipe by plastic deformation of the pipe,
A lower end of the tube opposite to the side receiving the impact load is provided with a set of cutout holes formed at intervals in the tube axis direction,
The set of notch holes is formed in two pairs at intervals in the pipe circumferential direction of the pipe body. 2. The protective fence column according to claim 1, wherein the pair of cutout holes are formed on the lowermost end side of the pipe body with an interval upward from the base plate. The tubular body is formed in a square cross section,
The guard fence post according to claim 1 or 2, wherein the pair of cutout holes are formed in a corner portion of the tubular body. The guard fence post according to any one of claims 1 to 3, wherein the set of cutout holes is a through-hole penetrating the tubular body. The set of cutout holes is a recess having a bottom surface formed on one or both of an outer surface and an inner surface of the tubular body. Guard post.

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