JP6404589B2 - Design method of guard fence support - Google Patents

Description

本発明は、車道や橋梁などの路肩に設けられている防護柵の一部をなす防護柵支柱の設計方法に関する。 The present invention relates to a method for designing a protection fence post that forms a part of a protection fence provided on a road shoulder such as a roadway or a bridge.

従来、車道や橋梁などの路肩に設けられている防護柵は、複数の防護柵支柱と、これら防護柵支柱間に架設された横梁から構成され、鋼材やアルミニウム合金鋳物、ダクタイル鋳鉄等が防護柵支柱の材料として用いられている。また、防護柵支柱は、設置面にアンカーボルトやナットで取付けられるベース部に支柱本体部が立設された構成となっている。   Conventionally, protective fences provided on the shoulders of roadways and bridges consist of multiple protective fence posts and horizontal beams installed between these protective fence posts. Steel, aluminum alloy castings, ductile cast iron, etc. are used as protective fences It is used as a material for the support. Moreover, the guard fence support | pillar becomes the structure by which the support | pillar main-body part was erected in the base part attached to an installation surface with an anchor bolt or a nut.

この種の防護柵支柱においては、支柱本体部を、車道に面する前面板材と、この前面板材の後方に配置される後面板材と、これら前面板材と後面板材とをつなぐ連結板材とを備えた構成とし、これらを互いに溶接により接合、または鋳型によって成型したものがある。そして、かかる支柱本体部を矩形板状のベース部上に溶接により立設、または鋳型によって支柱本体部とベース部とを一体として成型している。   In this type of guard fence column, the column main body portion includes a front plate member facing the roadway, a rear plate member disposed behind the front plate member, and a connecting plate member that connects the front plate member and the rear plate member. There is a configuration in which these are joined together by welding or molded by a mold. And this support | pillar main-body part stands by welding on a rectangular-plate-shaped base part, or the support | pillar main-body part and a base part are shape | molded integrally by the casting_mold | template.

また、後面板材の下部後面側に凹部等を設け、車両が防護柵に衝突し支柱本体部の上部に車道側から衝突荷重が作用すると、先ず横桟の圧潰、次いで支柱本体部が凹部を起点として後方へ変形し、車両の衝突エネルギーを吸収するように設計されている。   In addition, a recess or the like is provided on the lower rear side of the rear plate, and when the vehicle collides with the protective fence and a collision load acts on the upper part of the column main body from the roadway side, the horizontal beam is first crushed, and then the column main body starts from the concave. It is designed to deform rearward and absorb the collision energy of the vehicle.

また、車道側から衝突荷重が作用すると前面板材の前面や連結板材の前側には引張り力が生じ、後面板材の後面、特に凹部には圧縮力が生じる。従って、前面板材や連結板材に生じる引張り力によって亀裂が生じやすく、亀裂を起点として支柱が破断し、後方へ倒壊しやすくなる。   Further, when a collision load is applied from the roadway side, a tensile force is generated on the front surface of the front plate member and the front side of the connecting plate member, and a compressive force is generated on the rear surface of the rear plate member, particularly on the recess. Therefore, a crack is easily generated by the tensile force generated in the front plate member and the connecting plate member, and the support column is broken starting from the crack and easily collapses backward.

そこで、前面板材や連結板材に生じる引張り力による亀裂を生じ難くする技術が、たとえば特許文献１に開示されている。本技術によれば、凹部よりも高い位置で車両の接触や衝突時の衝撃により最も大きな引張り力が加わる前面板材に繋がる連結板材の部分を厚肉化することで補強している。   Therefore, for example, Patent Document 1 discloses a technique for making it difficult for a crack due to a tensile force generated in a front plate member or a connecting plate member to occur. According to the present technology, the portion of the connecting plate material that is connected to the front plate material to which the greatest tensile force is applied by the vehicle contact or impact at the time of collision at a position higher than the concave portion is reinforced by increasing the thickness.

特開平１１−３３６０３４号公報Japanese Patent Laid-Open No. 11-336034

確かに、特許文献１に開示された技術によれば、前面板材や連結板材に生じる引張り力による亀裂が生じ難くなることで、支柱本体部の強度を向上させることができる点では一定の効果があった。しかし、凹部の上部の断面剛性を高くして強度を向上させようとするものであることから、車両が防護柵に衝突した際の初期的な衝撃が非常に大きくなる傾向があった。   Certainly, according to the technique disclosed in Patent Document 1, it is difficult to generate a crack due to the tensile force generated in the front plate member and the connecting plate member, so that there is a certain effect in that the strength of the column main body can be improved. there were. However, since it is intended to improve the strength by increasing the cross-sectional rigidity of the upper part of the recess, the initial impact when the vehicle collides with the protective fence tends to be very large.

また、凹部よりも上部に位置する支柱本体部は、特別に応力分布の状況が考慮されたものではないため、凹部以外の支柱本体部による衝撃力の吸収効果があまり期待できず、車両が防護柵に衝突した際の初期的な衝撃を凹部以外で吸収し減衰させる効果が非常に低かった。   In addition, since the strut body located above the recess does not take into account the stress distribution, the impact force absorption effect by the strut body other than the recess cannot be expected so much and the vehicle is protected. The effect of absorbing and attenuating the initial impact at the time of collision with the fence other than the recess was very low.

また、前面板材や連結板材を補強するために連結板材の所定の箇所を圧肉化しているため、防護柵全体が重くなり、更には、材料費が嵩むため経済的に不利であると共に、施工時に作業者が取り扱うにはあまりにも重く煩雑であった。   In addition, because the front plate material and the connection plate material are reinforced by compressing predetermined portions of the connection plate material, the entire protective fence becomes heavy, and further, the material cost increases, which is economically disadvantageous and Sometimes it was too heavy and cumbersome for an operator to handle.

また、支柱本体部の強度を保つために、凹部を除きベース部から支柱本体部の上端部に至るまで幅広な外形となっており、車道側や路肩側からの透過性を改善することはできなかった。   In addition, in order to maintain the strength of the column main body part, it has a wide outer shape from the base part to the upper end part of the column main body part excluding the concave part, and it can improve the permeability from the roadway side or the road shoulder side. There wasn't.

本発明は、以上のような事情に鑑みてなされたものであり、車両衝突時の衝突エネルギーを効率よく吸収でき、軽量で取り扱い性に優れ、透過性の高い防護柵支柱を得ることができる防護柵支柱の設計方法を提供することを目的とする。 The present invention, as described above has been made in view of the circumstances, the collision energy during a vehicle collision can be efficiently absorbed, excellent handling property lightweight, it is possible to obtain a highly transparent protective fence post protection It aims at providing the design method of a fence support .

以上のような目的を達成するために、本発明は以下のようなものを提供する。   In order to achieve the above object, the present invention provides the following.

請求項１に係る発明は、設置面に固定されるベース部と、このベース部上に立ち上がり水平方向の一側に横梁を支持する支柱本体部と、を備えた防護柵支柱の設計方法であって、前記支柱本体部を、前記横梁を支持する第一面板材と、前記第一面板材に連結板材を介して連接される第二面板材と、を備えるとともに、前記横梁を支持する側の上部の所定箇所を水平方向に押圧力を付与した際に作用する応力が均一に分散するように形成された応力分散部と、前記第二面板材を前記第一面板材側に凹状となるように湾曲させた湾曲凹部を前記応力分散部の下側に有し、前記横梁を支持する側の前記所定箇所を水平方向に押圧力を付与した際に起点となって前記応力分散部を前記横梁を支持する側と反対側に傾倒させる応力集中部と、を備えた構成とし、前記横梁の極限曲げモーメントの合計との関係で、前記防護柵支柱の種別に応じて許容範囲が範囲をもって規定された極限支持力と、前記応力集中部からの塑性変形による前記応力分散部の傾倒に必要な最大の応力である塑性許容応力度と、前記極限支持力以上の値であり、且つ、前記応力集中部に前記塑性許容応力度が作用するように決定される最大支持力と、を用い、前記応力分散部における前記所定箇所から前記応力集中部の図心軸までの間に複数箇所の水平断面を設定し、各前記水平断面の断面係数を、次式（１）により、各前記水平断面の箇所に作用する応力が前記塑性許容応力度以下で均一となるように算出し、算出した各前記水平断面についての断面係数に基づいて前記応力分散部を設計することを特徴とする防護柵支柱の設計方法。
Ｚ＝Ｐｈ／σ ・・・（１）
ここで、Ｚ：断面係数、Ｐ：前記最大支持力、ｈ：前記所定箇所から各前記水平断面までの垂直距離、σ：応力である。 Inventions is according to claim 1, and a base portion which is fixed to the installation surface, a post body portion for supporting the cross beam on one side of the rising horizontal to the base unit on, with a protective fence post design method with a there, the strut body portion, a first surface plate for supporting the cross beam, and a second surface plate which is connected via a connecting plate to said first surface plate provided with a, side supporting the cross beam A stress distribution portion formed so as to uniformly disperse the stress acting when a pressing force is applied in a horizontal direction on a predetermined portion of the upper portion of the plate, and the second surface plate material is concave on the first surface plate material side. has a curved recess is curved in the lower side of the stress dispersion portion, said front Kisho constant part of the crossbeam of the supporting side is a starting point upon applying a pressing force in the horizontal direction the stress dispersion portion structure provided with a stress concentration portion which Ru is inclined to the side opposite to the side supporting the cross beam a And the stress distribution part due to plastic deformation from the stress concentration part and the ultimate support force with a tolerance range defined according to the type of the protective fence column in relation to the sum of the ultimate bending moments of the transverse beams The maximum allowable stress that is the maximum stress necessary for tilting and the maximum support force that is greater than or equal to the ultimate support force and that is determined so that the allowable plastic stress acts on the stress concentration portion. The horizontal cross section of a plurality of locations is set between the predetermined location in the stress distribution portion and the centroid axis of the stress concentration portion, and the section coefficient of each horizontal cross section is expressed by the following equation (1): The stress acting on each horizontal section is calculated so as to be uniform below the plastic allowable stress level, and the stress distribution portion is designed based on the calculated section modulus for each horizontal section. Protective fence A method of designing a pillar.
Z = Ph / σ (1)
Here, Z is a section modulus, P is the maximum supporting force, h is a vertical distance from the predetermined location to each horizontal section, and σ is stress.

本発明による防護柵支柱によれば、支柱本体部に、横梁を支持する側の上部の所定箇所を水平方向に押圧力を付与した際に作用する応力が均一に分散するように形成された応力分散部と、横梁を支持する側の上部の所定箇所を水平方向に押圧力を付与した際に起点となって横梁を支持する側と反対側に傾倒する応力集中部と、を備えることで、応力集中部のみならず応力分散部においても充分に衝撃力を吸収することができる。   According to the protective fence column according to the present invention, the stress that is applied to the column main body when the pressing force is applied in the horizontal direction to the predetermined portion on the upper side that supports the horizontal beam is uniformly distributed. By providing a dispersion part and a stress concentration part that tilts to the opposite side from the side that supports the horizontal beam as a starting point when applying a pressing force in the horizontal direction on the predetermined portion on the side that supports the horizontal beam, The impact force can be sufficiently absorbed not only in the stress concentration portion but also in the stress dispersion portion.

（ａ）は本発明の一実施形態に係る防護柵支柱の側面図であり、（ｂ）は（ａ）のＡ−Ａ断面図であり、（ｃ）は底面図である。(A) is a side view of the protection fence support | pillar which concerns on one Embodiment of this invention, (b) is AA sectional drawing of (a), (c) is a bottom view. （ａ）は本発明の一実施形態に係る防護柵支柱の正面斜視図であり、（ｂ）は背面斜視図である。(A) is a front perspective view of the protection fence support | pillar which concerns on one Embodiment of this invention, (b) is a rear perspective view. 本発明の一実施形態に係る防護柵支柱の使用状態の一例を示す斜視図である。It is a perspective view which shows an example of the use condition of the protection fence support | pillar which concerns on one Embodiment of this invention. （ａ）は従来の防護柵支柱の応力分布を模式的に示した図であり、（ｂ）は本発明の一実施形態に係る防護柵支柱の応力分布を模式的に示した図である。(A) is the figure which showed typically the stress distribution of the conventional protection fence support | pillar, (b) is the figure which showed typically the stress distribution of the protection fence support | pillar which concerns on one Embodiment of this invention. （ａ）最大支持力で傾倒する状態を示す側面図であり、（ｂ）は変形量１５０ｍｍ時の状態を示す側面図であり、（ｃ）変形量３００ｍｍ時の状態を示す側面図である。(A) It is a side view which shows the state inclined by the maximum support force, (b) is a side view which shows the state at the time of deformation amount 150mm, (c) It is a side view which shows the state at the time of deformation amount 300mm. 本発明の一実施形態に係る防護柵支柱の設計時に考慮される側面図である。It is a side view considered at the time of the design of the protection fence support | pillar which concerns on one Embodiment of this invention. 本発明の一実施形態に係る防護柵支柱の荷重−変形量曲線を示す図である。It is a figure which shows the load-deformation amount curve of the guard fence support | pillar which concerns on one Embodiment of this invention.

本発明の要旨は、支柱本体部に、横梁を支持する側の上部の所定箇所を水平方向に押圧力を付与した際に作用する応力が均一に分散するように形成された応力分散部と、横梁を支持する側の上部の所定箇所を水平方向に押圧力を付与した際に起点となって横梁を支持する側と反対側に傾倒する応力集中部と、を備えることで、応力集中部のみならず応力分散部においても充分に衝撃力を吸収することができるものである。すなわち、車両衝突時の衝突エネルギーを効率よく吸収することができる防護柵支柱の提供を図ろうとするものである。   The gist of the present invention is that the stress distribution part formed so that the stress acting when the pressing force is applied in the horizontal direction to the predetermined part of the upper part on the side supporting the cross beam is uniformly distributed to the column main body part, By providing a stress concentrating portion that starts from the side where the horizontal beam is supported and tilts in the opposite direction from the side that supports the horizontal beam when a pressing force is applied in the horizontal direction to the predetermined portion on the side supporting the horizontal beam, only the stress concentrating portion is provided. That is, the impact force can be sufficiently absorbed even in the stress dispersion portion. That is, an object of the present invention is to provide a protective fence post that can efficiently absorb collision energy at the time of a vehicle collision.

以下、本発明に係る防護柵支柱の一実施形態について図面を参照しながら説明する。また、本説明中において左右同一又は左右対称の構造や部品については、原則として同一の符号を付し、左右何れか一方のみを説明して、他方については説明を適宜省略する。   Hereinafter, an embodiment of a protective fence post according to the present invention will be described with reference to the drawings. In this description, the same or symmetrical structures and parts are assigned the same reference numerals in principle, and only one of the left and right is described, and the description of the other is omitted as appropriate.

図１（ａ）は本発明の一実施形態に係る防護柵支柱の側面図であり、（ｂ）は（ａ）のＡ−Ａ断面図であり、（ｃ）は底面図である。また、図２（ａ）は防護柵支柱の正面斜視図であり、（ｂ）は背面斜視図である。また、図３は防護柵支柱の使用状態の一例を示す斜視図であり、図４（ａ）は従来の防護柵支柱の応力分布を模式的に示した図であり、（ｂ）は本発明の一実施形態に係る防護柵支柱の応力分布を模式的に示した図である。   Fig.1 (a) is a side view of the guard fence support | pillar which concerns on one Embodiment of this invention, (b) is AA sectional drawing of (a), (c) is a bottom view. FIG. 2A is a front perspective view of the protective fence column, and FIG. 2B is a rear perspective view. FIG. 3 is a perspective view showing an example of the usage state of the guard fence post, FIG. 4 (a) is a diagram schematically showing the stress distribution of the conventional guard fence pillar, and FIG. It is the figure which showed typically the stress distribution of the guard fence support | pillar which concerns on one Embodiment.

本発明に係る防護柵支柱１は、設置面５０に固定されるベース部２と、このベース部２上に立ち上がり水平方向の一側に横梁６０を支持する支柱本体部３と、を備え、支柱本体部３は、横梁６０を支持する側の上部５の所定箇所Ｃを水平方向に押圧力Ｐを付与した際に作用する応力が均一に分散するように形成された応力分散部４と、横梁６０を支持する側の上部５の所定箇所Ｃを水平方向に押圧力Ｐを付与した際に起点となって横梁６０を支持する側と反対側に傾倒する応力集中部６と、を備えた構成となっている。   The protective fence post 1 according to the present invention includes a base portion 2 fixed to the installation surface 50 and a post main body portion 3 that stands on the base portion 2 and supports a cross beam 60 on one side in the horizontal direction. The main body 3 includes a stress distribution portion 4 formed so that stress acting when a pressing force P is applied in a horizontal direction to the predetermined portion C of the upper portion 5 on the side supporting the horizontal beam 60, and the horizontal beam A stress concentration portion 6 that starts from a predetermined point C of the upper portion 5 on the side supporting the 60 and tilts to the opposite side from the side that supports the horizontal beam 60 when a pressing force P is applied in the horizontal direction. It has become.

なお、支柱本体部３は、後述する湾曲凹部１６周縁を応力集中部６とし、湾曲凹部１６よりも上部を応力分散部４としている。   In addition, the support | pillar main-body part 3 makes the stress concentrating part 6 the periphery of the curved recessed part 16 mentioned later, and makes the upper part rather than the curved recessed part 16 the stress dispersion | distribution part 4. FIG.

このように構成することで、車両が防護柵５１に衝突した際の初期的な衝突エネルギーを応力分散部４の全長に渡り略均一に応力を発生させて衝撃力を吸収するように応力分散部４を変形させ、応力分散部４に亀裂が入る前に応力集中部６を起点として路肩５３側に応力分散部４を傾倒させることができる。   By configuring in this way, the stress distribution unit absorbs the impact force by generating the stress substantially uniformly over the entire length of the stress distribution unit 4 when the vehicle collides with the protective fence 51. 4 can be deformed, and the stress distribution part 4 can be tilted to the road shoulder 53 side from the stress concentration part 6 before the stress distribution part 4 is cracked.

ここで、防護柵支柱の上部５の所定箇所Ｃに車道５２側から押圧力Ｐを付与した際の従来の防護柵支柱１００の応力は、図４（ａ）で模式的に示すように、応力集中部６で応力が最大となるように、応力の分布が鋭角の頂点を上とした直角三角形状７で表される。しかし、本一実施形態に係る防護柵支柱１の応力は、図４（ｂ）に模式的に示すように、応力分散部４で応力が均一になるように、応力の分布が長手方向を上下とする長方形状８で表される。   Here, the stress of the conventional protective fence post 100 when the pressing force P is applied to the predetermined portion C of the upper part 5 of the protective fence post from the side of the roadway 52 is as shown schematically in FIG. The stress distribution is represented by a right-angled triangle shape 7 with an acute vertex at the top so that the stress is maximized at the concentrated portion 6. However, as shown schematically in FIG. 4B, the stress of the guard fence post 1 according to the present embodiment is such that the stress distribution is higher and lower in the longitudinal direction so that the stress is uniform in the stress dispersion portion 4. And is represented by a rectangular shape 8.

そして、防護柵支柱１は、図５に示すように、横梁６０を支持する側の上部５の所定箇所Ｃを水平方向に押圧力Ｐを付与した際に最終的に応力集中部６が起点となって路肩５３側に傾倒させるために、応力集中部６からの塑性変形による傾倒に必要な最大の応力、すなわち塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）が応力集中部６に作用するまでは、応力分散部４に作用する塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）以下の応力が応力分散部４に均一に分散されるように構成されている。 As shown in FIG. 5, when the protective fence support 1 is applied with a pressing force P in the horizontal direction at a predetermined portion C of the upper portion 5 on the side supporting the cross beam 60, the stress concentration portion 6 finally starts from the starting point. In order to tilt toward the road shoulder 53 side, the maximum stress necessary for tilting due to plastic deformation from the stress concentration portion 6, that is, until the plastic allowable stress σ _w (kN / cm ² ) acts on the stress concentration portion 6. Is configured such that stress having a plastic allowable stress σ _w (kN / cm ² ) or less acting on the stress dispersion portion 4 is uniformly dispersed in the stress dispersion portion 4.

このように構成することで、図５（ａ）に示すように、塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）が応力集中部６に作用するまで応力分散部４は後方に撓りながら押圧力Ｐを吸収することができる。特に、応力分散部４では応力分散部４に作用する応力が均一に分散されるため、後方への確実な撓りを発生させることができる。従って、車両が防護柵支柱１に衝突した際の初期的な衝撃力は応力分散部４によって可及的に吸収されると共に、その後、応力分散部４に作用する応力が塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）に至るまで衝撃力を吸収し続けることができる。 With this configuration, as shown in FIG. 5A, the stress dispersion portion 4 is pushed while being bent backward until the plastic allowable stress σ _w (kN / cm ² ) acts on the stress concentration portion 6. The pressure P can be absorbed. In particular, since the stress acting on the stress dispersion portion 4 is uniformly dispersed in the stress dispersion portion 4, it is possible to generate a reliable backward bending. Therefore, the initial impact force when the vehicle collides with the protective fence column 1 is absorbed as much as possible by the stress dispersion portion 4, and thereafter, the stress acting on the stress dispersion portion 4 becomes the plastic allowable stress σ _w. The impact force can continue to be absorbed up to (kN / cm ² ).

また、応力分散部４によって減衰した衝撃力による応力が塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）に達すると、図５（ｂ）、（ｃ）に示すように、応力集中部６を起点として応力分散部４の後方への傾倒が始まる。従って、塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）以上の応力が応力集中部６に作用した後は、応力分散部４を傾倒させながら応力集中部６で衝撃力を吸収させることができる。 Further, when the stress due to the impact force attenuated by the stress dispersing portion 4 reaches the plastic allowable stress degree σ _w (kN / cm ² ), the stress concentration portion 6 starts as shown in FIGS. As a result, the backward inclination of the stress dispersion portion 4 starts. Therefore, after a stress greater than the plastic allowable stress σ _w (kN / cm ² ) acts on the stress concentration portion 6, the stress concentration portion 6 can absorb the impact force while tilting the stress dispersion portion 4.

以上のように、本発明に係る防護柵支柱１は、応力集中部６のみならず応力分散部４においても充分に衝撃力を吸収することができるため、応力分散部４を有さない従来の防護柵支柱に比して効率的に衝撃力を減衰させることができる。   As described above, the protective fence column 1 according to the present invention can sufficiently absorb the impact force not only in the stress concentration portion 6 but also in the stress distribution portion 4, and thus does not have the stress distribution portion 4. The impact force can be attenuated more efficiently than the protective fence support.

以下に、本発明の一実施形態に係る防護柵支柱１の各部の構成について詳述する。   Below, the structure of each part of the guard fence support | pillar 1 which concerns on one Embodiment of this invention is explained in full detail.

防護柵支柱１はダクタイル鋳鉄による鋳物で形成され一体成型されたものであり、図１〜図３に示すように車道５２と路肩５３との境界部５４上の設置面５０に固定されるベース部２と、ベース部２上に立ち上がり、車道５２に沿って配設される上下２本の第一・第二横梁６０ａ，６０ｂを支持可能とする支柱本体部３とで構成されている。   The guard fence post 1 is formed of a cast made of ductile cast iron and integrally molded. As shown in FIGS. 1 to 3, the base portion fixed to the installation surface 50 on the boundary 54 between the roadway 52 and the road shoulder 53. 2 and a column main body 3 that stands on the base 2 and can support the upper and lower two first and second horizontal beams 60a and 60b disposed along the roadway 52.

ベース部２は図１、図３に示すように、矩形板状に形成され、各角部の近傍には楕円状の４つのアンカーボルト挿通孔９を形成し、設置面５０に植設された４つのアンカーボルト１０がアンカーボルト挿通孔９に挿通される。その後、ベース部２の上方に突出したアンカーボルト１０に４つのナット１１を螺合させて螺着固定することで防護柵支柱１を設置面５０に固定可能としている。   As shown in FIGS. 1 and 3, the base portion 2 is formed in a rectangular plate shape, and four elliptical anchor bolt insertion holes 9 are formed in the vicinity of each corner portion, and are implanted in the installation surface 50. Four anchor bolts 10 are inserted into the anchor bolt insertion holes 9. Thereafter, the guard fence support 1 can be fixed to the installation surface 50 by screwing and fixing the four nuts 11 to the anchor bolt 10 protruding above the base portion 2.

支柱本体部３は車道５２側に面して第一・第二横梁６０ａ，６０ｂを支持する面板材である第一面板材１２と、第一面板材１２に連結板材１３を介して連接される第二面板材１４とを備えており、これら各板材１２，１３，１４は一体に成型されている。なお、本一実施形態に係る防護柵支柱１では、図１（ｂ）、図２（ａ）、（ｂ）に示すように、第二面板材１４を第一面板材１２よりも幅狭とし、断面を略Ｔ字状に形成している。   The column main body 3 faces the roadway 52 side and is connected to the first face plate member 12 that is a face plate member that supports the first and second transverse beams 60a and 60b, and the first face plate member 12 via the connecting plate member 13. The second face plate material 14 is provided, and these plate materials 12, 13, and 14 are integrally molded. In the guard fence support 1 according to the present embodiment, the second face plate 14 is made narrower than the first face plate 12, as shown in FIGS. 1 (b), 2 (a), and (b). The cross section is formed in a substantially T shape.

また、支柱本体部３は下部においてベース部２と一体に成型されており、第一面板材１２とベース部２とが繋がる部分を第一面板材１２の最大幅となるように形成されている。すなわち、第一面板材１２は、車道５２側に面するベース部２の前面でベース部２と接続されており、ベース部２の該前面の幅を最大幅として形成されている。   The column main body 3 is formed integrally with the base portion 2 at the lower portion, and a portion where the first face plate material 12 and the base portion 2 are connected is formed to have the maximum width of the first face plate material 12. . That is, the first face plate member 12 is connected to the base portion 2 on the front surface of the base portion 2 facing the roadway 52 side, and is formed with the width of the front surface of the base portion 2 as the maximum width.

また、第二面板材１４とベース部２とが繋がる部分を第二面板材１４の最大幅となるように第二面板材１４の下部をベース部２側へ緩やかな拡開状となるように形成されている。すなわち、第二面板材１４は、路肩５３側に面するベース部２の後面でベース部２と接続されており、ベース部２の該後面の中央部においてベース部２の幅の略３分の１を最大幅となるように形成されている。   Further, the lower portion of the second face plate material 14 is gradually expanded toward the base portion 2 so that the portion where the second face plate material 14 and the base portion 2 are connected becomes the maximum width of the second face plate material 14. Is formed. That is, the second surface plate member 14 is connected to the base portion 2 at the rear surface of the base portion 2 facing the road shoulder 53 side, and is approximately a third of the width of the base portion 2 at the central portion of the rear surface of the base portion 2. 1 is formed to be the maximum width.

また、支柱本体部３は、特に第一面板材１２、及び連結板材１３の幅を上部５に向けて先鋭となるように形成することで、支柱本体部３全体が上部５に向けて先鋭となるように形成されている。なお、第二面板材１４の幅についても上部５に向けて僅かに先鋭となるように形成されている。また、図１（ａ）に示すように、第一面板材１２の厚みは、ベース部２側から上部５にかけて徐々に薄板となるように形成されている。   Further, the column main body part 3 is formed so that the width of the first face plate member 12 and the connecting plate member 13 is particularly sharpened toward the upper part 5, so that the entire column main body part 3 is sharpened toward the upper part 5. It is formed to become. The width of the second face plate 14 is also formed to be slightly sharper toward the upper portion 5. Moreover, as shown to Fig.1 (a), the thickness of the 1st surface board | plate material 12 is formed so that it may become a thin plate gradually from the base part 2 side to the upper part 5. As shown in FIG.

このように支柱本体部３全体、ひいてはベース部２から支柱本体部３の上端部に渡り、上部５に向けて先鋭となるように形成することができるのは、支柱本体部３の応力分散部４に作用する応力が均一に分散されるように形成されているからであり、これにより、防護柵支柱１を軽量化でき、更に、車道５２側や路肩５３側からの透過性を向上させることができる。   In this way, the entire strut main body 3, that is, from the base 2 to the upper end of the strut main body 3, can be formed to be sharp toward the upper portion 5. This is because the stress acting on 4 is formed so as to be evenly distributed, thereby making it possible to reduce the weight of the protective fence column 1 and to further improve the permeability from the roadway 52 side or the road shoulder 53 side. Can do.

また、支柱本体部３は、ベース部２側から略３分の１の高さにおいて第一面板材１２を路肩５３側に僅かに傾けた屈曲部１５を形成し、屈曲部１５よりも上部を略垂直に形成している。更に、ベース部２側から略５分の１の高さにおいて第二面板材１４を車道５２側に凹状となるように湾曲させた湾曲凹部１６を形成し、湾曲凹部１６よりも上部を緩やかに車道５２側に傾斜するようにして第一面板材１２の上端部近傍と接続している。   Further, the column main body portion 3 forms a bent portion 15 in which the first face plate 12 is slightly inclined toward the road shoulder 53 at a height of about one third from the base portion 2 side, and the upper portion of the column main body portion 3 is higher than the bent portion 15. It is formed substantially vertically. Further, a curved concave portion 16 is formed by bending the second face plate material 14 so as to be concave toward the roadway 52 at a height of about one-fifth from the base portion 2 side, and the upper portion of the curved concave portion 16 is gently formed. It is connected to the vicinity of the upper end portion of the first face plate 12 so as to be inclined toward the roadway 52 side.

また、支柱本体部３には第一・第二横梁６０ａ，６０ｂを支持するために、車道５２側に凹状の湾曲面からなる第一横梁受部１７と第二横梁受部１８とが形成されている。各湾曲面は外径の異なる２つの横梁６０ａ，６０ｂの曲率と略同一の曲率に形成されている。第一横梁受部１７は、第二横梁６０ｂよりも大径の第一横梁６０ａを支持可能とし、第一面板材１２の上端部において幅広とした湾曲面の凹側を第一面板材１２の車道５２側に位置する面に連続して形成されている。すなわち、第一横梁受部１７は、上部５に向けて先鋭とした第一面板材１２の上端部近傍において、第一面板材１２の幅よりも広い幅で形成されている。   Further, in order to support the first and second transverse beams 60a and 60b, the column main body portion 3 is formed with a first transverse beam receiving portion 17 and a second transverse beam receiving portion 18 each having a concave curved surface on the roadway 52 side. ing. Each curved surface is formed to have substantially the same curvature as that of the two transverse beams 60a and 60b having different outer diameters. The first transverse beam receiving portion 17 can support the first transverse beam 60a having a diameter larger than that of the second transverse beam 60b, and the concave side of the curved surface which is wide at the upper end portion of the first face plate 12 is formed on the first surface plate 12. It is formed continuously on the surface located on the roadway 52 side. That is, the first cross beam receiving portion 17 is formed with a width wider than the width of the first face plate member 12 in the vicinity of the upper end portion of the first face plate member 12 sharpened toward the upper portion 5.

また、第一横梁６０ａを水平方向に安定して支持するために左右２つの第一横梁固定孔１９が湾曲面を貫通するように穿設されている。従って、路肩５３側から第一横梁固定孔１９にボルト（図示せず）等を挿通して第一横梁６０ａに形成された雌ネジ部（図示せず）等と螺合させ、第一横梁受部１７に第一横梁６０ａを固定させることができる。   Further, in order to stably support the first horizontal beam 60a in the horizontal direction, the left and right first horizontal beam fixing holes 19 are formed so as to penetrate the curved surface. Therefore, a bolt (not shown) or the like is inserted from the road shoulder 53 side into the first transverse beam fixing hole 19 and is screwed with a female screw portion (not shown) or the like formed in the first transverse beam 60a. The first transverse beam 60 a can be fixed to the portion 17.

また、第一横梁受部１７の裏面となる路肩５３側には、垂直方向に形成した板状の補強リブ２０を備え、補強リブ２０の下部側が第二面板材１４の上端部周面の中央部で接続されている。   Further, a plate-shaped reinforcing rib 20 formed in the vertical direction is provided on the side of the road shoulder 53 that is the back surface of the first cross beam receiving portion 17, and the lower side of the reinforcing rib 20 is the center of the upper end portion peripheral surface of the second face plate member 14. Connected in the department.

また、第二横梁受部１８は、第一横梁６０ａよりも小径の第二横梁６０ｂを支持可能とし、第一面板材１２の長手方向における中央下部近傍において、湾曲面の凹側を車道５２側に若干だけ突出させ、更に、第一面板材１２の当該位置の幅よりも若干だけ幅広として形成している。また、第二横梁６０ｂを水平方向に安定して支持するために左右２つの第二横梁固定孔２１が湾曲面を貫通するように穿設されている。従って、路肩５３側から第二横梁固定孔２１にボルト（図示せず）等を挿通して第二横梁６０ｂに形成された雌ネジ部（図示せず）等と螺合させ、第二横梁受部１８に第二横梁６０ｂを固定させることができる。   The second transverse beam receiving portion 18 can support the second transverse beam 60b having a diameter smaller than that of the first transverse beam 60a, and the concave side of the curved surface is arranged on the side of the roadway 52 in the vicinity of the center lower portion in the longitudinal direction of the first face plate member 12. The first face plate 12 is formed so as to be slightly wider than the width of the corresponding position of the first face plate 12. In addition, in order to stably support the second horizontal beam 60b in the horizontal direction, two left and right second horizontal beam fixing holes 21 are formed so as to penetrate the curved surface. Accordingly, a bolt (not shown) or the like is inserted into the second transverse beam fixing hole 21 from the road shoulder 53 side and is screwed with a female screw portion (not shown) or the like formed on the second transverse beam 60b. The second transverse beam 60b can be fixed to the portion 18.

以上のように、本一実施形態に係る防護柵支柱１は構成されている。   As described above, the protective fence post 1 according to the present embodiment is configured.

[設計例]
次に、本発明に係る防護柵支柱１の「応力分散部４」と「応力集中部６」を主とした設計手順の一例を以下に説明する。なお、防護柵は、平成２０年１月付けの社団法人日本道路協会発行の「防護柵の設置基準・同解説」（以下、「基準書」とする。）に基づいて設計されるため、図５、図６、図７と共に基準書に準じて説明を行う。 [Design example]
Next, an example of a design procedure mainly including the “stress distribution portion 4” and the “stress concentration portion 6” of the guard fence post 1 according to the present invention will be described. The guard fence is designed based on the “Protection Fence Installation Standards / Description” (hereinafter referred to as “Standard Document”) published by the Japan Road Association dated January 2008. 5, FIG. 6 and FIG.

なお、本防護柵支柱１は、基準書においてＢ種に分類され、ベース部２の底面側から上部の所定箇所（中心Ｃ）までの高さＨが８００ｍｍとしたダクタイル鋳鉄製の防護柵支柱である。   This guard fence post 1 is classified as Class B in the standard document, and is a duct fence cast iron guard fence pillar having a height H of 800 mm from the bottom surface side of the base portion 2 to the upper predetermined portion (center C). is there.

図５（ａ）は最大支持力で傾倒する状態を示す側面図であり、（ｂ）は変形量１５０ｍｍ時の状態を示す側面図であり、（ｃ）は変形量３００ｍｍ時の状態を示す側面図である。また、図６は防護柵支柱１の設計時に考慮される側面図であり、図７は防護柵支柱１の荷重−変形量曲線を示す図である。   FIG. 5A is a side view showing a state of tilting with the maximum support force, FIG. 5B is a side view showing a state when the deformation amount is 150 mm, and FIG. 5C is a side view showing a state when the deformation amount is 300 mm. FIG. FIG. 6 is a side view taken into consideration when designing the guard fence post 1, and FIG. 7 is a diagram showing a load-deformation amount curve of the guard fence pillar 1.

まず、防護柵支柱は複数の種別に分類されており、種別に応じて防護柵支柱の極限支持力Ｐ_ｗ（ｋＮ）の許容範囲が部材選定域として定められている。具体的には、横梁の外径や本数等によって変化する横梁の極限曲げモーメントの合計Ｍｏを縦軸とした際に、算出または試験によって得られた横梁の極限曲げモーメントの合計Ｍｏと部材選定域とで囲まれた範囲に相当する横軸の防護柵支柱の極限支持力Ｐ_ｗ（ｋＮ）が範囲をもって規定される（基準書ｐ１０１）。従って、防護柵支柱の極限支持力Ｐ_ｗ（ｋＮ）は、この範囲内から決定されることになる。 First, the guard fence columns are classified into a plurality of types, and an allowable range of the ultimate support force P _w (kN) of the guard fence columns is determined as a member selection area according to the types. Specifically, when the total Mo of the bending moment of the transverse beam, which varies depending on the outer diameter and number of the transverse beams, is taken as the vertical axis, the total bending moment Mo of the transverse beam obtained by calculation or test and the member selection area The limit support force P _w (kN) of the protective fence column on the horizontal axis corresponding to the range surrounded by is defined with a range (reference document p101). Therefore, the ultimate support force P _w (kN) of the protective fence post is determined from this range.

次に、防護柵支柱の最大支持力Ｐ_ｍａｘ（ｋＮ）は、防護柵支柱の極限支持力Ｐ_ｗ（ｋＮ）以上の値である必要があり、且つ、防護柵支柱の最大支持力Ｐ_ｍａｘ（ｋＮ）で応力集中部６に塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）が作用するように決定する。具体的には以下のように算出される。 Next, the maximum support force P _max (kN) of the guard fence column needs to be a value equal to or greater than the limit support force P _w (kN) of the guard fence column, and the maximum support force P _max ( kN) so that the allowable plastic stress σ _w (kN / cm ² ) acts on the stress concentration portion 6. Specifically, it is calculated as follows.

［数１］
Ｍ＝Ｐｈ
σ＝Ｍ／Ｚ
Ｍ：曲げモーメント（ｋＮｃｍ）
Ｐ：押圧力（ｋＮ）
ｈ：押圧力Ｐ（ｋＮ）を付与する中心Ｃからの垂直距離（ｃｍ）
σ：応力（ｋＮ／ｃｍ^２）
Ｚ：断面係数（ｃｍ^３） [Equation 1]
M = Ph
σ = M / Z
M: Bending moment (kNcm)
P: Pressing force (kN)
h: Vertical distance (cm) from the center C to which the pressing force P (kN) is applied
σ: Stress (kN / cm ² )
Z: Section modulus (cm ³ )

［数２］
Ｐ＝σＺ／ｈ [Equation 2]
P = σZ / h

応力σ（ｋＮ／ｃｍ^２）は材料によって規定される塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）とし、断面係数Ｚ（ｃｍ^３）は応力集中部６の湾曲凹部１６の断面係数Ｚ_ｇ（ｃｍ^３）とし、垂直距離ｈ（ｃｍ）は押圧力Ｐ（ｋＮ）を付与する上側の第一横梁６０ａの所定箇所である中心Ｃから応力集中部６の図心軸Ｇまでの垂直距離ｈ_ｇとし、押圧力Ｐ（ｋＮ）を防護柵支柱１の最大支持力Ｐ_ｍａｘ（ｋＮ）として防護柵支柱１の極限支持力Ｐ_ｗ（ｋＮ）の範囲内となるように決定する。従って、以下の数式（数３）によって最大支持力Ｐ_ｍａｘ（ｋＮ）が算出される。 The stress σ (kN / cm ² ) is the allowable plastic stress σ _w (kN / cm ² ) defined by the material, and the section modulus Z (cm ³ ) is the section modulus Z _g ( cm ³ ), and the vertical distance h (cm) is the vertical distance h _g from the center C, which is a predetermined position of the upper first transverse beam 60a to which the pressing force P (kN) is applied, to the centroid G of the stress concentration portion 6. And the pressing force P (kN) is determined to be within the range of the ultimate support force P _w (kN) of the guard fence post 1 as the maximum support force P _max (kN) of the guard fence post 1. Therefore, the maximum support force P _max (kN) is calculated by the following equation (Equation 3).

［数３］
Ｐ_ｍａｘ＝σ_ｗＺ_ｇ／ｈ_ｇ [Equation 3]
P _max = σ _w Z _g / h _g

ここで、本一実施形態に係る防護柵支柱１の静荷重試験の結果である荷重−変形量曲線を図７に示す。これによると、極限支持力Ｐ_ｗ（ｋＮ）は２３．１ｋＮであり、最大支持力Ｐ_ｍａｘ（ｋＮ）は３６．６ｋＮとなる。また、最大支持力Ｐ_ｍａｘ（ｋＮ）を支柱上部５の中心Ｃに受けた際の防護柵支柱１は、図５（ａ）に示すような状態であり、この時点から応力集中部６に応力が集中することになる。 Here, FIG. 7 shows a load-deformation amount curve as a result of the static load test of the protective fence support 1 according to the present embodiment. According to this, the ultimate support force P _w (kN) is 23.1 kN, and the maximum support force P _max (kN) is 36.6 kN. Further, the protective fence column 1 when the maximum support force P _max (kN) is received at the center C of the column upper part 5 is in a state as shown in FIG. 5A, and stress is applied to the stress concentration portion 6 from this point. Will concentrate.

次に、応力分散部４については、応力分散部４に作用する応力が均等となるように、例えば、図６に示すように、押圧力Ｐ（ｋＮ）を付与する上側の第一横梁６０ａの中心Ｃから応力集中部６の図心軸Ｇまでの間において、当該間隔を略５等分するように中心Ｃから下方へ１０ｃｍの等間隔で４箇所Ａ，Ｂ，Ｃ，Ｄの水平断面を設定した場合、これらの箇所に作用する応力が少なくとも塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）に至るまでは応力分散部４に均一に作用するように構成される。 Next, with respect to the stress dispersion portion 4, for example, as shown in FIG. 6, the stress acting on the stress dispersion portion 4 is equalized by the upper first horizontal beam 60 a that applies the pressing force P (kN). From the center C to the centroid axis G of the stress concentration portion 6, horizontal sections of four locations A, B, C, and D are equally spaced at a distance of 10 cm from the center C so as to divide the distance into approximately five equal parts. When set, the stress is applied uniformly to the stress dispersion portion 4 until the stress acting on these places reaches at least the allowable plastic stress σ _w (kN / cm ² ).

すなわち、少なくとも最大支持力Ｐ_ｍａｘ（ｋＮ）となる図５（ａ）の状態までは応力分散部４に作用する応力は均一に分散されることになる。従って、応力分散部４による効果は、従来の防護柵支柱に比して、図７における最大支持力Ｐ_ｍａｘ（ｋＮ）となる変形量が右側にシフトすることで確認できる。これは、応力分散部４での衝撃吸収性の向上を示すことになる。 That is, the stress acting on the stress dispersion portion 4 is uniformly dispersed until at least the state shown in FIG. 5A where the maximum support force P _max (kN) is obtained. Therefore, the effect by the stress dispersion | distribution part 4 can be confirmed by the amount of deformation | transformation used as the maximum supporting force _Pmax (kN) in FIG. 7 shifting to the right side compared with the conventional guard fence support | pillar. This indicates an improvement in impact absorbability at the stress dispersion portion 4.

このように構成するためには、設定した４箇所の各断面係数Ｚ_{１０〜４０}（ｃｍ^３）を算出する必要がある。この場合、算出されるのは１０ｃｍ間隔の各断面係数Ｚ_{１０〜４０}（ｃｍ^３）であることから、算出されない部分の断面係数Ｚ（ｃｍ^３）は、算出された前後の断面係数Ｚ（ｃｍ^３）から勾配を求め、近似的に当該箇所の断面係数Ｚ（ｃｍ^３）とすればよい。なお、応力分散部４に作用する応力を、応力分散部４の何れの位置においても精度よく設計するためには断面係数Ｚ（ｃｍ^３）の設定箇所を増やせばよい。 Thus in order to configure, it is necessary to calculate each section modulus of four locations set _{Z 10~40} (cm ^3). In this case, since being calculated is the section modulus _{Z 10 to 40} of 10cm spacing (cm ^3), the section modulus of not calculated moiety Z (cm ³⁾ is the section modulus before and after the calculated Z (cm ³ ), the gradient may be obtained and approximated to the section modulus Z (cm ³ ) of the location. In order to design the stress acting on the stress dispersion portion 4 accurately at any position of the stress dispersion portion 4, the number of setting points of the section modulus Z (cm ³ ) may be increased.

設定した４箇所の各断面係数Ｚ_{１０〜４０}（ｃｍ^３）の具体的な算出方法は、上述した数式（数２）において、垂直距離ｈ（ｃｍ）は押圧力Ｐ（ｋＮ）を付与する上側の第一横梁６０ａの中心Ｃから下方へ１０、２０、３０、４０ｃｍの箇所の各図心軸Ｇ_{１０〜４０}までの垂直距離ｈ_{１０〜４０}（この場合は、全て水平断面なので図心軸Ｇ_{１０〜４０}の算出は不要）とし、押圧力Ｐ（ｋＮ）を防護柵支柱１の最大支持力Ｐ_ｍａｘ（ｋＮ）とし、応力σ（ｋＮ／ｃｍ^２）は塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）として算出される。従って、以下の数式（数４）によって設定した４箇所の各断面係数Ｚ_{１０〜４０}（ｃｍ^３）が算出される。 The specific calculation method for each of the four section coefficients Z _{10 to 40} (cm ³ ) set is as follows. In the above-described equation (Equation 2), the vertical distance h (cm) is the upper side that gives the pressing force P (kN). Vertical distances h ₁₀ to 40 from the center C of the first transverse beam 60a to the centroids G ₁₀ to 40 at positions 10, 20, 30, and ₄₀ cm downward (in this case, since all are horizontal sections, the centroid axis G _{10 to 40} is not required), the pressing force P (kN) is the maximum support force P _max (kN) of the protective fence column 1, and the stress σ (kN / cm ² ) is the allowable plastic stress σ _w (kN / cm ² ). Accordingly, each of the four section coefficients Z _{10 to 40} (cm ³ ) set by the following formula (Equation 4) is calculated.

［数４］
Ｚ_{１０〜４０}＝Ｐ_ｍａｘｈ_{１０〜４０}／σ_ｗ [Equation 4]
Z _10-40 = P _max h _10-40 / σ _w

以上のようにして算出された各断面係数Ｚ_{１０〜４０}（ｃｍ^３）に基づいて応力分散部４を設計すれば、少なくとも塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）に至るまでは応力分散部４に作用する応力を均一にすることができる。 If the stress distribution part 4 is designed based on each section modulus Z _10-40 (cm ³ ) calculated as described above, the stress distribution is at least until the allowable plastic stress σ _w (kN / cm ² ) is reached. The stress acting on the portion 4 can be made uniform.

なお、上述した数式（数４）においては、応力集中部６が起点となって応力集中部６の塑性変形により応力分散部４を傾倒させるために、応力σ（ｋＮ／ｃｍ^２）を塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）と同等とすることが望ましい。この場合、算出された設計値と現物による測定値との誤差を考慮した上で、応力分散部４が必要以上に重くならず、応力集中部６の影響を受けることなく応力分散部４での安定した衝撃吸収性能を発揮させるために、数式（数４）で用いる応力σ（ｋＮ／ｃｍ^２）を塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）よりも小さく、塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）の５％減以内、または、塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）よりも小さく、塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）の１０％減以内としてもよい。 In the above-described formula (Equation 4), the stress σ (kN / cm ² ) is plastically allowable in order to tilt the stress dispersion portion 4 by the plastic deformation of the stress concentration portion 6 starting from the stress concentration portion 6. It is desirable to make it equivalent to the stress degree σ _w (kN / cm ² ). In this case, in consideration of an error between the calculated design value and the actual measurement value, the stress dispersion portion 4 does not become heavier than necessary and is not affected by the stress concentration portion 6. In order to exhibit stable shock absorbing performance, the stress σ (kN / cm ² ) used in the equation (Equation 4) is smaller than the allowable plastic stress σ _w (kN / cm ² ), and the allowable plastic stress σ _w ( kN / cm ²⁾ within down 5 percent, or, less than the plastic allowable stress ^{_{σ w (kN / cm 2)}} , may be within 10% reduction plastic allowable stress ^{_{σ w (kN / cm 2)}} .

上述した防護柵支柱の設計手順は一例であり、本説明に限定されるものではなく、例えば、水平断面から断面係数Ｚ（ｃｍ^３）を算出するのではなく、各部の形状を考慮して断面係数Ｚ（ｃｍ^３）を算出する等、本発明の要旨の範囲内において種々の方法を用いることができる。 The design procedure of the protective fence support described above is an example, and is not limited to the present description. For example, the cross-section coefficient Z (cm ³ ) is not calculated from the horizontal cross-section, and the cross-section is taken into account the shape of each part. Various methods can be used within the scope of the present invention, such as calculating the coefficient Z (cm ³ ).

また、本一実施形態に係る防護柵支柱１は、ダクタイル鋳鉄を用いており、断面を略Ｔ字状に形成しているが、これらは本一実施形態に限定されるものではなく、本発明の要旨の範囲内において種々の変形、変更が可能であることは言うまでもない。   Moreover, although the protection fence support | pillar 1 which concerns on this one embodiment uses ductile cast iron, and the cross section is formed in the substantially T shape, these are not limited to this one embodiment, This invention It goes without saying that various modifications and changes can be made within the scope of the present invention.

以上のようにして防護柵支柱１を設計することで、ベース部２から支柱本体部３の上端部に渡り、上部５に向けて先鋭となるように形成することができる。これにより、防護柵支柱１を軽量化でき、材料費の削減によって経済的に有利になると共に、施工時の取り扱い性を向上させることができる。更に、車道５２側や路肩５３側からの透過性を向上させることができる。   By designing the protective fence column 1 as described above, it can be formed so as to be sharpened toward the upper portion 5 from the base portion 2 to the upper end portion of the column body portion 3. Thereby, the protective fence support | pillar 1 can be reduced in weight, while it becomes economically advantageous by reduction of material cost, and the handleability at the time of construction can be improved. Furthermore, the permeability from the roadway 52 side or the road shoulder 53 side can be improved.

また、図５（ａ）に示すように、塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）が応力集中部６に作用するまで応力分散部４は後方に撓りながら押圧力Ｐ（ｋＮ）を吸収することができる。特に、応力分散部４では応力分散部４に作用する応力が均一に分散されるため、後方への確実な撓りを発生させることができる。従って、車両が防護柵支柱１に衝突した際の初期的な衝撃力は応力分散部４によって可及的に吸収されると共に、その後、応力分散部４に作用する応力が塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）に至るまで衝撃力を吸収し続けることができる。 Further, as shown in FIG. 5 (a), the stress dispersion portion 4 deflects backward while applying the pressing force P (kN) until the plastic allowable stress σ _w (kN / cm ² ) acts on the stress concentration portion 6. Can be absorbed. In particular, since the stress acting on the stress dispersion portion 4 is uniformly dispersed in the stress dispersion portion 4, it is possible to generate a reliable backward bending. Therefore, the initial impact force when the vehicle collides with the protective fence column 1 is absorbed as much as possible by the stress dispersion portion 4, and thereafter, the stress acting on the stress dispersion portion 4 becomes the plastic allowable stress σ _w. The impact force can continue to be absorbed up to (kN / cm ² ).

また、応力分散部４によって減衰した衝撃力による応力が塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）に達すると、図５（ｂ）、（ｃ）に示すように、応力集中部６を起点として応力分散部４の後方への傾倒が始まる。従って、塑性許容応力度σ_ｗ（ｋＮ／ｃｍ^２）以上の応力が応力集中部６に作用した後は、応力分散部４を傾倒させながら応力集中部６で衝撃力を吸収させることができる。 Further, when the stress due to the impact force attenuated by the stress dispersing portion 4 reaches the plastic allowable stress degree σ _w (kN / cm ² ), the stress concentration portion 6 starts as shown in FIGS. As a result, the backward inclination of the stress dispersion portion 4 starts. Therefore, after a stress greater than the plastic allowable stress σ _w (kN / cm ² ) acts on the stress concentration portion 6, the stress concentration portion 6 can absorb the impact force while tilting the stress dispersion portion 4.

このように、本発明に係る防護柵支柱１は、応力集中部６のみならず応力分散部４においても充分に衝撃力を吸収することができるため、応力分散部４を有さない従来の防護柵支柱に比して効率的に衝撃力を減衰させることができる。   As described above, the protective fence column 1 according to the present invention can sufficiently absorb the impact force not only in the stress concentration portion 6 but also in the stress distribution portion 4, so that the conventional protection without the stress distribution portion 4 is provided. The impact force can be attenuated more efficiently than the fence post.

以上、本発明の好ましい実施形態を説明したが、本発明は係る特定の実施形態や変形例に限定されるものではなく、特許請求の範囲に記載された本発明の要旨の範囲内において、種々の変形・変更が可能である。   The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments and modifications, and various modifications can be made within the scope of the gist of the present invention described in the claims. Can be modified or changed.

Ｃ 所定箇所（中心）
Ｐ 押圧力
Ｐ_ｍａｘ 最大支持力
σ_ｗ 最大の応力
１ 防護柵支柱
２ ベース部
３ 支柱本体部
４ 応力分散部
５ 上部
６ 応力集中部
１２ 第一面板材
１３ 連結板材
１４ 第二面板材
５０ 設置面
６０ 横梁 C Predetermined location (center)
P Pressing force P _max Maximum support force σ _w Maximum stress 1 Guard fence support 2 Base part 3 Support body part 4 Stress dispersion part 5 Upper part 6 Stress concentration part 12 First surface plate material 13 Connection plate material 14 Second surface plate material 50 Installation surface 60 cross beam

Claims (1)

設置面に固定されるベース部と、このベース部上に立ち上がり水平方向の一側に横梁を支持する支柱本体部と、を備えた防護柵支柱の設計方法であって、
前記支柱本体部を、
前記横梁を支持する第一面板材と、前記第一面板材に連結板材を介して連接される第二面板材と、を備えるとともに、
前記横梁を支持する側の上部の所定箇所を水平方向に押圧力を付与した際に作用する応力が均一に分散するように形成された応力分散部と、
前記第二面板材を前記第一面板材側に凹状となるように湾曲させた湾曲凹部を前記応力分散部の下側に有し、前記横梁を支持する側の前記所定箇所を水平方向に押圧力を付与した際に起点となって前記応力分散部を前記横梁を支持する側と反対側に傾倒させる応力集中部と、を備えた構成とし、
前記横梁の極限曲げモーメントの合計との関係で、前記防護柵支柱の種別に応じて許容範囲が範囲をもって規定された極限支持力と、
前記応力集中部からの塑性変形による前記応力分散部の傾倒に必要な最大の応力である塑性許容応力度と、
前記極限支持力以上の値であり、且つ、前記応力集中部に前記塑性許容応力度が作用するように決定される最大支持力と、を用い、
前記応力分散部における前記所定箇所から前記応力集中部の図心軸までの間に複数箇所の水平断面を設定し、
各前記水平断面の断面係数を、次式（１）により、各前記水平断面の箇所に作用する応力が前記塑性許容応力度以下で均一となるように算出し、
算出した各前記水平断面についての断面係数に基づいて前記応力分散部を設計する
ことを特徴とする防護柵支柱の設計方法。
Ｚ＝Ｐｈ／σ ・・・（１）
ここで、Ｚ：断面係数、Ｐ：前記最大支持力、ｈ：前記所定箇所から各前記水平断面までの垂直距離、σ：応力である。 A protection fence column design method comprising a base unit fixed to an installation surface, and a column body unit that stands on the base unit and supports a horizontal beam on one side in the horizontal direction ,
The column main body is
A first face plate that supports the transverse beam, and a second face plate that is connected to the first face plate via a connecting plate,
A stress distribution portion formed so that stress acting when a pressing force is applied in a horizontal direction to a predetermined portion on the upper side supporting the horizontal beam is uniformly distributed;
Wherein the dihedral plate has a curved recess is curved in a concave shape to said first surface plate side to the lower side of the stress dispersion portion, the horizontal direction before Kisho constant position on the side for supporting the lateral beam and the stress dispersion portion is a starting point upon applying a pressing force to the side for supporting the lateral beam and the stress concentrated portions Ru is tilted to the opposite side, a configuration with a,
In relation to the sum of the ultimate bending moment of the transverse beam, the ultimate support force with an allowable range defined according to the type of the guard fence post, and
Plastic allowable stress degree, which is the maximum stress necessary for tilting the stress dispersion part due to plastic deformation from the stress concentration part;
A maximum support force that is a value equal to or greater than the ultimate support force and is determined such that the plastic allowable stress acts on the stress concentration portion,
A plurality of horizontal cross sections are set between the predetermined location in the stress dispersion portion and the centroid of the stress concentration portion,
The section modulus of each horizontal section is calculated according to the following equation (1) so that the stress acting on the location of each horizontal section is equal to or less than the allowable plastic stress,
A design method for a protective fence post , wherein the stress distribution portion is designed based on the calculated section modulus for each horizontal section .
Z = Ph / σ (1)
Here, Z is a section modulus, P is the maximum supporting force, h is a vertical distance from the predetermined location to each horizontal section, and σ is stress.

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