JP3756979B2

JP3756979B2 - Girder fall prevention structure

Info

Publication number: JP3756979B2
Application number: JP08205196A
Authority: JP
Inventors: 篤司市川; 清満村田; 直人御船; 安志西本
Original assignee: Railway Technical Research Institute; Shibata Industrial Co Ltd
Current assignee: Railway Technical Research Institute; Shibata Industrial Co Ltd
Priority date: 1996-03-11
Filing date: 1996-03-11
Publication date: 2006-03-22
Anticipated expiration: 2016-03-11
Also published as: JPH09242019A

Description

【０００１】
【発明の属する技術分野】
本発明は、鉄道や道路等に用いる桁と、橋脚や橋台等の桁支持構造物との間、又は連続する桁どうしの間に設ける桁落下防止構造に関するものである。
【０００２】
【従来の技術】
従来、この種の桁落下防止構造は、図７の要部説明図に示すように構成されていた。図７に示すように、この桁落下防止構造２００は、橋脚１と桁２との間に設けられていた。桁２は、支承部材３を介して橋脚１上に支持されていた。
【０００３】
また、この桁落下防止構造２００は、橋脚１の上端部付近に側面等に固定された定着部材８Ｂと、桁２の端部付近の下面等に固定された定着部材１０Ｂと、これらの間を接続するチェーン４Ｂを備えて構成されていた。このチェーン４Ｂの両端は、各定着部材８Ｂ，１０Ｂに直接、又は環やピン等を介して取り付けられていた。
【０００４】
また、上記のチェーン４Ｂは、桁２が温度により伸縮することに対応させるためと、チェーン４Ｂの長さがリング単位となり定着部材８Ｂ，１０Ｂ間の距離とまったく同一の長さにすることができないことから、若干たるませた状態で設置されていた。
【０００５】
【発明が解決しようとする課題】
しかしながら、上記従来の桁落下防止構造２００においては、桁２が温度変化により伸縮して定着部材８Ｂ，１０Ｂ間の距離が増減した場合、特に２点間の距離が長くなった場合に追随できず、桁２や橋脚１に不測の引抜力を作用させ、桁の変位や橋脚の損傷等の悪影響を及ぼすおそれがあった。
【０００６】
また、上記したように、定着部材８Ｂ，１０Ｂ間を接続するチェーン４Ｂは、通常たるんだ状態にある。したがって、地震時のように、水平方向あるいは垂直方向に瞬間的に大きな振動が加わった場合、弛緩していたチェーン４Ｂに急激な引張力が作用する。このためチェーン４Ｂが破断し、最悪の場合には桁２が落下する、というおそれもあった。
【０００７】
また、上記のような大きな振動により、チェーン４Ｂ自体は破断しなくても、定着部材８Ｂ，１０Ｂのボルト等や、チェーン４Ｂと各定着部材８Ｂ，１０Ｂとを連結する部分等が破断し、桁２と橋脚１とが分離してしまうので、桁の落下を防止する、という本来の機能が果たせなくなる、という問題があった。
【０００８】
本発明は上記の問題を解決するためになされたものであり、本発明の解決しようとする課題は、地震力等の衝撃力が作用しても桁落下防止機能を十分確保し得る桁落下防止構造を提供することにある。
【０００９】
【発明を解決するための手段】
上記課題を解決するため、本発明の請求項１に係る桁落下防止構造は、複数の閉合体（６）の各々が接触しないように間隙を配して相互に嵌合させるとともに前記閉合体（６）の全体を直線状に整列させた状態で前記各閉合体（６）を弾性体（７）内に埋設しかつ前記間隙にも前記弾性体（７）を充填することにより略棒状に形成した緩衝部材（５）の一端部（６０）を桁（２）の端部付近に定着させ、前記桁（２）を支持する桁支持構造物（１）の上部付近に前記緩衝部材（５）の他端部（６０）を定着させ、前記緩衝部材（５）の端部と前記桁支持構造物（１）の上部付近との間に、チェーン（４）を設けたことを特徴とする。
【００１０】
また、本発明の請求項２に係る桁落下防止構造は、複数の閉合体（６）の各々が接触しないように間隙を配して相互に嵌合させるとともに前記閉合体（６）の全体を直線状に整列させた状態で前記各閉合体（６）を弾性体（７）内に埋設しかつ前記間隙にも前記弾性体（７）を充填することにより略棒状に形成した緩衝部材（５）の一端部（６０）を桁（２）の端部付近に定着させ、前記桁（２）に隣接する他の桁である隣接桁（２Ａ）の端部付近に前記緩衝部材（５）の他端部（６０）を定着させ、前記緩衝部材（５）の端部と前記桁（２）の端部付近との間に、チェーン（４）を設けたことを特徴とする。
【００１１】
また、本発明の請求項３に係る桁落下防止構造は、請求項１記載の桁落下防止構造において、前記桁支持構造物（１）の上部付近には、金属からなる金具である定着部材（８）が緩衝ボルト（１２）により固定されるとともに、前記緩衝ボルト（１２）は、軸部（１３）の周囲に弾力材と布材とが交互に積層された衝撃緩和部（１４）を有することを特徴とする。
【００１２】
また、本発明の請求項４に係る桁落下防止構造は、請求項２記載の桁落下防止構造において、前記隣接桁（２Ａ）の端部付近には、金属からなる金具である定着部材（８）が緩衝ボルト（１２）により固定されるとともに、前記緩衝ボルト（１２）は、軸部（１３）の周囲に弾力材と布材とが交互に積層された衝撃緩和部（１４）を有することを特徴とする。
【００１３】
また、本発明の請求項５に係る桁落下防止構造は、請求項１記載の桁落下防止構造において、前記桁（２）の端部付近には、金属からなる金具である定着部材（１０）が緩衝ボルト（１２）により固定されるとともに、前記緩衝ボルト（１２）は、軸部（１３）の周囲に弾力材と布材とが交互に積層された衝撃緩和部（１４）を有することを特徴とする。
【００１４】
また、本発明の請求項６に係る桁落下防止構造は、請求項２記載の桁落下防止構造において、前記桁（２）の端部付近には、金属からなる金具である定着部材（１０）が緩衝ボルト（１２）により固定されるとともに、前記緩衝ボルト（１２）は、軸部（１３）の周囲に弾力材と布材とが交互に積層された衝撃緩和部（１４）を有することを特徴とする。
【００１５】
また、本発明の請求項７に係る桁落下防止構造は、請求項３記載の桁落下防止構造において、前記桁支持構造物（１）の上部付近に固定された定着部材（８）の平面状部材（３１）の面上に立設された第２ヒンジ片（３２、３２）には、金属からなる金具である連結部材（９）の一端である第１ヒンジ片（２３）がヒンジピン（１７）により回動可能に取り付けられ、前記連結部材（９）の他端には、円形孔（２１）と、その内部の空間（２２）が設けられ、前記円形孔（２１）に緩衝ピン（１２Ａ）が挿入され、前記緩衝ピン（１２Ａ）は、軸部（１３Ａ）の周囲に弾力材と布材とが交互に積層された衝撃緩和部（１４Ａ）を有し、前記空間（２２）内で前記緩衝ピン（１２Ａ）の衝撃緩和部（１４Ａ）に前記緩衝部材（５）の端部（６０）が嵌合して装着されることを特徴とする。
【００１６】
また、本発明の請求項８に係る桁落下防止構造は、請求項４記載の桁落下防止構造において、前記隣接桁（２Ａ）の端部付近に固定された定着部材（８）の平面状部材（３１）の面上に立設された第２ヒンジ片（３２、３２）には、金属からなる金具である連結部材（９）の一端である第１ヒンジ片（２３）がヒンジピン（１７）により回動可能に取り付けられ、前記連結部材（９）の他端には、円形孔（２１）と、その内部の空間（２２）が設けられ、前記円形孔（２１）に緩衝ピン（１２Ａ）が挿入され、前記緩衝ピン（１２Ａ）は、軸部（１３Ａ）の周囲に弾力材と布材とが交互に積層された衝撃緩和部（１４Ａ）を有し、前記空間（２２）内で前記緩衝ピン（１２Ａ）の衝撃緩和部（１４Ａ）に前記緩衝部材（５）の端部（６０）が嵌合して装着されることを特徴とする。
【００１７】
また、本発明の請求項９に係る桁落下防止構造は、請求項５記載の桁落下防止構造において、前記桁（２）の端部付近に固定された定着部材（１０）の平面状部材（３１）の面上に立設された第２ヒンジ片（３２、３２）には、金属からなる金具である連結部材（１１）の一端である第１ヒンジ片（２３）がヒンジピン（１７）により回動可能に取り付けられ、前記連結部材（９）の他端には、円形孔（２１）と、その内部の空間（２２）が設けられ、前記円形孔（２１）に緩衝ピン（１２Ａ）が挿入され、前記緩衝ピン（１２Ａ）は、軸部（１３Ａ）の周囲に弾力材と布材とが交互に積層された衝撃緩和部（１４Ａ）を有し、前記空間（２２）内で前記緩衝ピン（１２Ａ）の衝撃緩和部（１４Ａ）に前記緩衝部材（５）の端部（６０）が嵌合して装着されることを特徴とする。
【００１８】
また、本発明の請求項１０に係る桁落下防止構造は、請求項６記載の桁落下防止構造において、前記桁（２）の端部付近に固定された定着部材（１０）の平面状部材（３１）の面上に立設された第２ヒンジ片（３２、３２）には、金属からなる金具である連結部材（１１）の一端である第１ヒンジ片（２３）がヒンジピン（１７）により回動可能に取り付けられ、前記連結部材（９）の他端には、円形孔（２１）と、その内部の空間（２２）が設けられ、前記円形孔（２１）に緩衝ピン（１２Ａ）が挿入され、前記緩衝ピン（１２Ａ）は、軸部（１３Ａ）の周囲に弾力材と布材とが交互に積層された衝撃緩和部（１４Ａ）を有し、前記空間（２２）内で前記緩衝ピン（１２Ａ）の衝撃緩和部（１４Ａ）に前記緩衝部材（５）の端部（６０）が嵌合して装着されることを特徴とする。
【００１９】
また、本発明の請求項１１に係る桁落下防止構造は、請求項１記載の桁落下防止構造において、前記緩衝部材（５）の端部を、前記桁支持構造物（１）の上部付近に固定された金属からなる金具である定着部材（８）に、前記緩衝部材（５）の軸回りに回動可能に定着させたことを特徴とする。
【００２０】
また、本発明の請求項１２に係る桁落下防止構造は、請求項２記載の桁落下防止構造において、前記緩衝部材（５）の端部を、前記桁（２）に隣接する他の桁である隣接桁（２Ａ）の端部付近に固定された金属からなる金具である定着部材（８）に、前記緩衝部材（５）の軸回りに回動可能に定着させたことを特徴とする。
【００２１】
【発明の実施の形態】
以下、本発明の実施形態について、図面を参照しながら詳細に説明する。
【００２２】
図１は、本発明の一実施形態である桁落下防止構造の構成を示した要部説明図である。
図１に示すように、この桁落下防止構造１０１は、橋脚１と桁２との間をつなぐように設けられる。桁２は、支承部材３を介して橋脚１上に支持されている。また、桁２には、桁２Ａが隣接・連続しており、桁２Ａは、支承部材３Ａを介して橋脚１上に支持されている。
【００２３】
また、この桁落下防止構造１０１は、橋脚１の上端部付近に側面等に固定された定着部材８と、桁２の端部付近の下面等に固定された定着部材１０と、これらの間に配置された緩衝部材５と、緩衝部材５の一端と定着部材８とを連結する連結部材９と、緩衝部材５の他端と定着部材１０とを連結する連結部材１１を備えて構成されている。
【００２４】
次に、以下に、上記した緩衝部材５のさらに詳細な構成について、図２を参照しつつ説明する。図２に示すように、この緩衝部材５は、略丸棒状に形成されており、複数のリング６，６，…の周囲に、ゴムや合成樹脂等の弾性体７を略円柱状に充填して形成されている。各リング６，６，…の各々は、互いに接触しないように所定の間隙を配して配列され、相互に嵌合し、チェーンを形成している。また、これら複数のリング６，６，…の全体は、直線状に整列されている。
【００２５】
なお、図２においては、リング６としては長円状の環が図示されているが、円状や楕円状、略「ロ」字状でもよく、略「θ」字状や略「日」字状の部材のように中間に結合部材が取り付けられてもよく、一般に線の両端が閉じた閉合体であればよい。
【００２６】
上記の緩衝部材５は、例えば、リング６，６，…を上記の状態で金型（図示せず）等の中に配置し、各リング６，６，…の周囲に弾性体となるべき未固化の原料を流し込み、固化させることにより形成される。弾性体７がゴムの場合には、さらに金型（図示せず）内において加熱する加硫工程等を施す。
【００２７】
この緩衝部材５においては、各リング６，６，…が弾性体７内に埋設されるとともに、各リング間の間隙にも弾性体７が充填される。また、緩衝部材５の両端には、端部のリング６０，６０の一部が弾性体７の外部に露出しており、この部分が略環状をなし、他の部材と連結可能になっている。あるいは、緩衝部材５の両端のリングに別の取付金具（図示せず）を嵌合させておき、この取付金具（図示せず）の一部が弾性体７の外部に露出させるようにしてもよい。
【００２８】
このように構成されることにより、緩衝部材５の端リング６０，６０間に軸方向の引張力が作用すると、この引張力により緩衝部材５内に発生する引張応力は、緩衝部材５の内部の弾性体７を介して各リング６に伝達される。したがって、地震力のような衝撃的応力が加わっても、弾性体７により緩和・減衰された後に各リング６に伝達されるので、従来の裸の状態のチェーン４（図７）の場合とは異なり、破断することがない。
【００２９】
次に、上記した連結部材と定着部材のさらに詳細な構成について、図３を参照しつつ説明する。図３は、例として、連結部材９と定着部材８の構成を示しているが、桁２と連結する側の連結部材１１と定着部材１０の構成も同様である。
図３に示すように、連結部材９は、例えば鋼鉄等の金属からなる金具であり、その一端（図上の左端）には、接続具である緩衝ピン１２Ａが装着可能な円形孔２１が設けられ、この円形孔２１に緩衝ピン１２Ａが挿入され装着されている。
【００３０】
また、緩衝ピン１２Ａの軸部１３Ａには、後述する衝撃緩和部１４Ａが設けられており、この衝撃緩和部１４Ａの周囲は空間２２となっており、この空間２２内で緩衝部材５の端部の端リング６０が緩衝ピン１２Ａの衝撃緩和部１４Ａに嵌合し装着されるようになっている。このため、緩衝部材５は、軸部１３Ａのまわりに回動可能となっている。
【００３１】
また、連結部材９の他端（図上の右端）には円盤の一部をなす形状に形成された第１ヒンジ片２３が設けられており、この第１ヒンジ片２３にヒンジピン１７が挿入可能な円形孔が設けられている。
一方、定着部材８は、例えば鋼鉄等の金属からなる金具であり、平板状部材３１の略中央に、円盤の一部をなす形状に形成された２つの第２ヒンジ片３２，３２（一方のみ図示）が平板状部材３１の面上で互いに離間されて垂直に立設されている。また、２つ第２ヒンジ片３２，３２にはヒンジピン１７が挿入可能な円形孔が設けられている。
【００３２】
そして、２つの第２ヒンジ片３２，３２の間のスリット空間（図示せず）内に、第１ヒンジ片２３が挿入されて各円形孔が連通するように整合され、円形孔内に丸棒状のヒンジピン１７が挿入された後、ヒンジピン１７の両端が円形孔から抜け出さないように拡径処理されている。このため、連結部材９は、ヒンジピン１７のまわりに回動可能となっている。
【００３３】
また、定着部材８の平面状部材３１には、第２ヒンジ片３２をはさんで両側には、それぞれ固定具である緩衝ボルト１２が挿入可能な円形孔３３が設けられている。また、これらの円形孔３３，３３に連通するようにして、橋脚１にボルト孔３４，３４が設けられている。ボルト孔３４の内周面には、雌ネジが形成されている。この円形孔３３には、それぞれ緩衝ボルト１２が挿入され、緩衝ボルト１２の軸部１３の根元側に設けられた後述する衝撃緩和部１４が円形孔３３の内壁と対向し、緩衝ボルト１２の軸部の先端側外周面に形成された雄ネジがボルト孔３４の内周面の雌ネジと螺合することにより、定着部材８が橋脚１に固定されるようになっている。
【００３４】
次に、上記した緩衝ボルト１２と緩衝ピン１２Ａのさらに詳細な構成について、図５を参照しつつ説明する。
図５（Ａ）に示すように、緩衝ボルト１２は、軸部１３と、衝撃緩和部１４と、押え板１５を有して構成されている。衝撃緩和部１４は、六角形状の頭部から延びる軸部１３の根元側（六角形状頭部側）の周囲に設けられており、弾力材と布材とが交互に積層された形成されている。弾力材としては、ゴムや合成樹脂等からなる帯状材が用いられ、布材としては天然繊維又は合成繊維等からなる織布又は不織布等が用いられる。押え板１５は、ボルトの六角形状の頭部と衝撃緩和部１４との間に配置されている。また、軸部１３の先端部（六角形状頭部の反対側の端部）の外周面には、上述したように雄ネジが形成されている。
【００３５】
上記の衝撃緩和部１４は、例えば、上記の帯状材の裏面又は表面に同一形状の布材を当接し、弾力材と布材の２層からなる帯状材とし、軸部１３の周囲に巻回し、接着又は加熱溶着等により略円筒状に成形する。弾力材がゴムの場合には、さらに金型（図示せず）内において加熱する加硫工程等を施す。
【００３６】
また、図５（Ｂ）に示すように、緩衝ピン１２Ａは、円盤状のフランジ部から延びる軸部１３Ａと、衝撃緩和部１４Ａと、キャップ１６を有して構成されている。衝撃緩和部１４Ａは、軸部１３Ａの根元側（円盤状フランジ側）の周囲に設けられており、その構成は、上記した緩衝ボルト１２の衝撃緩和部１４とまったく同様である。
【００３７】
上記の軸部１３Ａの先端部（円盤状フランジ部の反対側の端部）には雌ネジ孔２５が形成されている。また、キャップ１６は、円盤状のフランジ部から延びる軸部を有しており、このキャップ１６の軸部の外周面には、雌ネジ孔２５と螺合可能な雄ネジが形成されている。
【００３８】
したがって、図３に示す連結部材９の円形孔２１に緩衝ピン１２Ａを装着する場合には、例えば、図３において円形孔２１の右上方から緩衝ピン１２Ａの衝撃緩和部１３Ａの部分を挿入し、図３において円形孔２１の左下方にのぞく雌ネジ孔２５にキャップ１６を螺着させることにより、緩衝ピン１２Ａが円形孔２１から抜け出さないように装着することができる。
【００３９】
図４は、図１に示す桁落下防止構造における連結部材と定着部材の他の構成例を示す図である。図４は、例として、他の連結部材９Ａと定着部材８Ａの構成を示しているが、桁２と連結する側の連結部材と定着部材の構成も同様である。
図４に示すように、連結部材９Ａは、例えば鋼鉄等の金属からなる金具であり、平板状部材の一側に抜出防止部３５が垂直に（図の下方に）立設され、平板状部材には、上記した緩衝ボルト１２の衝撃緩和部１４が挿入可能な円形孔３６が設けられている。また、抜出防止部３５を設けるかわりに、平板状部材を、緩衝部材５の端リング６０又は取付金具（図示せず）の平面投影面（定着部材方向への投影面）よりも大きな形状としてもよい。
【００４０】
また、定着部材８Ａは、例えば鋼鉄等の金属からなる金具であり、ブロック状部材に、上記した緩衝ボルト１２の軸部１３の先端付近が挿入可能な円形孔３７が設けられている。
また、円形孔３７に連通するようにして、橋脚１にボルト孔３８が設けられている。ボルト孔３８の内周面には、雌ネジが形成されている。上記の円形孔により緩衝ボルト１２が挿入可能となっており、緩衝ボルト１２の軸部１３の衝撃緩和部１４に、緩衝部材５の端リング６０が嵌合し装着されるようになっている。また、緩衝ボルト１２の軸部の先端側外周面に形成された雄ネジがボルト孔３８の内周面の雌ネジと螺合することにより、定着部材８Ａが橋脚１に固定されるようになっている。このように構成しても、緩衝部材５を桁２や橋脚１に定着することができる。
【００４１】
この場合、緩衝部材５は、緩衝ボルト１２の軸部１３のまわりに回動可能となっている。また、連結部材９Ａには、抜出防止部３５が設けられたり、連結部材９Ａの平板状部材の投影面が、緩衝部材５の端リング６０又は取付金具（図示せず）よりも大きく設定されているので、緩衝部材５の端リング６０又は取付金具（図示せず）と緩衝ボルト１２との嵌合が外れることはない。
【００４２】
図４に示す定着方式においては、緩衝ボルト１２を、緩衝部材５と連結部材９Ａとを接続する接続具と、連結部材９Ａを定着部材８Ａに固定する固定具とを兼用させるようにして用いることができる。あるいは、図４に示した定着部材８Ａを他の別のアンカーボルト等により橋脚１や桁２に固定しておき、緩衝ボルト１２を接続具としてのみ使用してもよい。あるいはまた、定着部材８Ａを橋脚１や桁２と別体の部材とせず、橋脚１や桁２の一部、例えば突起部として形成してもよい。
【００４３】
上記のような構成により、橋脚１が図の上下方向又は左右方向に振動し、定着部材８又は８Ａと緩衝ボルト１２との間のせん断力や、緩衝ボルト１２の引抜力等が作用しても、これらの力は、緩衝ボルト１２の衝撃緩和部１４により緩和され、緩衝部材５に軸方向の減衰した引張力として伝達される。
逆に、緩衝部材５側から橋脚１側へ向う引張力は、緩衝ボルト１２の衝撃緩和部１４により緩和され、減衰したせん断力やボルトの引抜力等として橋脚１側へ伝達される。
【００４４】
同様にして、図１において、桁２が図の上下方向又は左右方向に振動し、定着部材１０とその固定用の緩衝ボルト１２との間のせん断力や、緩衝ボルト１２の引抜力等が作用しても、これらの力は、固定用の緩衝ボルト１２の衝撃緩和部１４により緩和され、緩衝部材５に減衰した引張力として伝達される。
逆に、緩衝部材５側から桁２側へ向う引張力は、緩衝ボルト１２の衝撃緩和部１４により緩和され、減衰したせん断力やボルトの引抜力等として桁２側へ伝達される。
【００４５】
一方、連結部材９，９Ａ又は１１と、緩衝部材５との間には、緩衝ピン１２Ａの衝撃緩和部１４Ａ又は緩衝ボルト１２の衝撃緩和部１４が介在するため、この部分により、緩衝部材５へ向う力、あるいは緩衝部材５からの力は、緩和・減衰されて伝達される。
また、上記したように、緩衝部材５に伝達された力は、弾性体７により緩和・減衰される。
【００４６】
したがって、この桁落下防止構造１０１に地震力のような衝撃的応力が加わっても、衝撃緩和部１４Ａあるいは１４の弾力材により、さらには緩衝部材５内の弾性体７により緩和・減衰されるので、従来の裸の状態のチェーン４（図７）の場合とは異なり、緩衝部材５の端リング６０，緩衝ピン１２Ａ，連結部材９又は１１，ヒンジピン１７，定着部材８又は１０，緩衝ボルト１２などが損傷又は破断することはない。
また、緩衝部材５が弾性を有するため、桁落下防止構造の設置時の公差に追随可能である、という利点もある。
【００４７】
本発明は、他の実施形態としても実施可能である。
例えば、図６に示すように構成してもよい。図６に示すように、この桁落下防止構造１０２は、図１に示す桁落下防止構造１０１の橋脚側の連結部材９と定着部材８との間に、複数のリング６Ａからなるチェーン４を介在させたものである。
【００４８】
このように介在部材を配置すると、桁落下防止構造の設置長さが緩衝部材５の長さよりもかなり長い場合などに、チェーン４によって長さ調整を行うことが可能となる。
介在部材としては、他の構成のものも使用可能であり、鋼棒や細長い鋼材等であってもよい。また、上記の鋼棒等の両端にネジを形成して両端を螺合により連結部材と定着部材に取り付けることもできる。
【００４９】
また、この変形として、いわゆる「ターンバックル」状の部材を介在部材としてもよい。ターンバックルのような部材を用いれば、回動することにより介在部材の部材長を増減調整することが可能となる。
【００５０】
また、介在部材は、図６に示すように、桁落下防止構造の橋脚側の連結部材と定着部材との間に設けるだけでなく、桁落下防止構造の桁側の連結部材と定着部材との間に設けてもよく、また、橋脚側及び桁側の双方に設けてもよい。
【００５１】
さらに他の実施形態として、図示はしないが、隣接する桁２Ａと桁２との間に上記と同様の構成の桁落下防止構造を配置してもよい。また、桁２と橋脚１との間と、隣接する桁２Ａと桁２との間の双方に、上記と同様の構成の桁落下防止構造を配置してもよい。
【００５２】
なお、上記した緩衝部材５が衝撃緩和機能を発揮し得る応力の上限値は、実験によれば、緩衝部材５内に埋設されるチェーンの材質には関係がなく、概ね緩衝部材５内に埋設されるチェーンの断面応力値でσc ＝２５０kg/cm2となっている。また、実験結果より、この緩衝部材５の引張耐力は、埋設されるチェーンの断面積の２倍にチェーンの断面応力値を乗じた値に等しくなっている。このため、緩衝部材５内に埋設されるチェーンの直径をｄとすると、緩衝部材５の引張耐力Ｐは、下式
Ｐ＝π・ｄ2 ・σc ／２
で与えられる。
【００５３】
なお、本発明は、上記各実施形態に限定されるものではない。上記各実施形態は、例示であり、本発明の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本発明の技術的範囲に包含される。
【００５４】
例えば、上記各実施形態においては、連結部材として、図３に示すような緩衝ピン１２Ａ、あるいは図４に示すような緩衝ボルトを使用する例について説明したが、本発明はこれには限定されず、他の構造であってもよく、例えば、環状部材の組み合わせ、環状部材とピンとの組み合わせ、環状部材とフックとの組み合わせ、あるいは螺合による連結等であってもよく、機械的な連結であればどのようなものであってもよい。また、各嵌合部分に、上記した衝撃緩和部１４又は１４Ａと同様の衝撃緩和部を設けるようにしてもよい。
【００５５】
また、上記各実施形態においては、図３に示すように、緩衝ピン１２Ａの軸回りに回動可能でかつヒンジピン１７の軸回りに回動可能な例、あるいは図４に示すように、緩衝ボルト１２の軸回りに回動可能な例などについて説明したが、本発明はこれには限定されず、図３において、さらに緩衝部材５の軸回りに回動可能に構成してもよい。このように構成すると、３次元のいずれの方向の回動も可能となり、地震力等により桁落下防止構造にねじれ力が作用した場合でも、各部に悪影響や損傷等を与えることがない。
【００５６】
【発明の効果】
以上説明したように、本発明によれば、複数の閉合体（６）の各々が接触しないように間隙を配して相互に嵌合させるとともに閉合体（６）の全体を直線状に整列させた状態で各閉合体（６）を弾性体（７）内に埋設しかつ間隙にも弾性体（７）を充填することにより略棒状に形成した緩衝部材（５）の一端部（６０）を桁（２）の端部付近に定着させ、桁（２）を支持する桁支持構造物（１）の上部付近に緩衝部材（５）の他端部（６０）を定着させ、緩衝部材（５）の端部と桁支持構造物（１）の上部付近との間に、チェーン（４）を設けるようにするか、あるいは、複数の閉合体（６）の各々が接触しないように間隙を配して相互に嵌合させるとともに閉合体（６）の全体を直線状に整列させた状態で各閉合体（６）を弾性体（７）内に埋設しかつ間隙にも弾性体（７）を充填することにより略棒状に形成した緩衝部材（５）の一端部（６０）を桁（２）の端部付近に定着させ、桁（２）に隣接する他の桁である隣接桁（２Ａ）の端部付近に緩衝部材（５）の他端部（６０）を定着させ、緩衝部材（５）の端部と桁（２）の端部付近との間に、チェーン（４）を設けるようにしたので、地震力のような衝撃的外力が加わっても、緩衝部材により緩和・減衰され、つねに良好な桁落下防止機能を果たすことができる。
また、緩衝部材（５）が弾性を有するため、桁落下防止構造の設置時の公差に対応可能である、という利点もある。
【図面の簡単な説明】
【図１】本発明の一実施形態である桁落下防止構造の構成を示す要部説明図である。
【図２】図１に示す桁落下防止構造における緩衝部材の構成を示す一部欠截斜視図である。
【図３】図１に示す桁落下防止構造における連結部材と定着部材の一構成例を示す図である。
【図４】図１に示す桁落下防止構造における連結部材と定着部材の他の構成例を示す図である。
【図５】図１及び図２に示す桁落下防止構造に用いる固定具又は接続具の構成例を示す図であり、図５（Ａ）はボルトとして構成した例を、図５（Ｂ）はピンとして構成した例を、それぞれ示している。
【図６】本発明の他の実施形態である桁落下防止構造の構成を示す要部説明図である。
【図７】従来の桁落下防止構造の構成を示す要部説明図である。
【符号の説明】
１橋脚
２，２Ａ桁
３支承部材
４チェーン
５緩衝部材
６，６Ａリング
７弾性体
８，８Ａ，１０定着部材
９，９Ａ，１１連結部材
１２緩衝ボルト
１２Ａ緩衝ピン
１３，１３Ａ軸部
１４，１４Ａ衝撃緩和部
１５押え板
１６キャップ
２５ネジ孔
１７ヒンジピン
２１円形孔
２２空間
２３第１ヒンジ片
３１平板状部材
３２第２ヒンジ片
３３円形孔
３４ボルト孔
３５抜出防止部
３６，３７円形孔
３８ボルト孔
６０端リング
１０１，１０２，２００桁落下防止構造[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a girder falling prevention structure provided between a girder used for a railway or a road and a girder support structure such as a pier or an abutment or between successive girder.
[0002]
[Prior art]
Conventionally, this type of girder dropping prevention structure has been configured as shown in the explanatory view of the main part in FIG. As shown in FIG. 7, this girder fall prevention structure 200 was provided between the pier 1 and the girder 2. The girder 2 was supported on the pier 1 via the support member 3.
[0003]
The girder dropping prevention structure 200 includes a fixing member 8B fixed to the side surface near the upper end of the pier 1 and a fixing member 10B fixed to the lower surface near the end of the girder 2 and the space between them. The chain 4B to be connected is provided. Both ends of the chain 4B are attached to the fixing members 8B and 10B directly or via a ring or a pin.
[0004]
Further, the above-described chain 4B cannot cope with the expansion and contraction of the beam 2 due to temperature, and the length of the chain 4B is a ring unit and cannot be exactly the same as the distance between the fixing members 8B and 10B. Therefore, it was installed in a slightly slack state.
[0005]
[Problems to be solved by the invention]
However, the conventional girder dropping prevention structure 200 cannot follow when the girder 2 expands and contracts due to a temperature change and the distance between the fixing members 8B and 10B increases or decreases, especially when the distance between the two points increases. Unexpected pulling force was applied to the girder 2 and the pier 1 and there was a risk of adverse effects such as displacement of the girder and damage to the pier.
[0006]
Further, as described above, the chain 4B connecting the fixing members 8B and 10B is normally in a slack state. Therefore, when a large vibration is instantaneously applied in the horizontal direction or the vertical direction as in an earthquake, a sudden tensile force acts on the relaxed chain 4B. For this reason, the chain 4B was broken, and in the worst case, the girder 2 could be dropped.
[0007]
Further, due to the large vibration as described above, even if the chain 4B itself does not break, the bolts of the fixing members 8B and 10B, the portions connecting the chain 4B and the fixing members 8B and 10B, etc. are broken, and the beam Since 2 and the pier 1 are separated, there is a problem that the original function of preventing the girder from dropping cannot be performed.
[0008]
The present invention has been made to solve the above-mentioned problems, and the problem to be solved by the present invention is to prevent a girder falling that can sufficiently ensure a girder falling prevention function even when an impact force such as seismic force is applied. To provide a structure.
[0009]
[Means for Solving the Invention]
In order to solve the above-described problem, the girder dropping prevention structure according to claim 1 of the present invention is arranged so that each of the plurality of closing bodies (6) is fitted with a gap so as not to contact each other, and the closing body ( 6) Each of the closed bodies (6) is embedded in an elastic body (7) in a state where the whole is linearly aligned, and the gap is filled with the elastic body (7) to form a substantially rod shape. One end (60) of the buffer member (5) is fixed near the end of the beam (2), and the buffer member (5) is near the upper portion of the beam support structure (1) for supporting the beam (2). Fix the other end (60) of A chain (4) is provided between the end of the buffer member (5) and the vicinity of the upper part of the girder support structure (1). It is characterized by that.
[0010]
Moreover, the girder dropping prevention structure according to claim 2 of the present invention is arranged so that each of the plurality of closed bodies (6) does not come into contact with each other with a gap, and the entire closed body (6) is fitted. A buffer member (5) formed in a substantially rod shape by embedding each of the closed bodies (6) in an elastic body (7) in a state of being linearly aligned and filling the gap with the elastic body (7). ) Is fixed in the vicinity of the end of the beam (2), and the buffer member (5) is positioned near the end of the adjacent beam (2A), which is another beam adjacent to the beam (2). Fix the other end (60) A chain (4) is provided between the end of the buffer member (5) and the vicinity of the end of the beam (2). It is characterized by that.
[0011]
The girder drop prevention structure according to claim 3 of the present invention is the girder drop prevention structure according to claim 1, wherein a fixing member (a metal fitting) is provided near the upper part of the girder support structure (1). 8) is fixed by a buffer bolt (12), and the buffer bolt (12) has an impact relaxation portion (14) in which elastic materials and cloth materials are alternately laminated around the shaft portion (13). It is characterized by that.
[0012]
The girder drop prevention structure according to claim 4 of the present invention is the girder drop prevention structure according to claim 2, wherein the fixing member (8) is a metal fitting near the end of the adjacent girder (2A). ) Is fixed by the buffer bolt (12), and the buffer bolt (12) has an impact relaxation portion (14) in which elastic material and cloth material are alternately stacked around the shaft portion (13). It is characterized by.
[0013]
The girder drop prevention structure according to claim 5 of the present invention is the girder drop prevention structure according to claim 1, wherein the fixing member (10) is a metal fitting in the vicinity of the end of the girder (2). Is fixed by a buffer bolt (12), and the buffer bolt (12) has an impact relaxation portion (14) in which elastic materials and cloth materials are alternately laminated around the shaft portion (13). Features.
[0014]
The girder drop prevention structure according to claim 6 of the present invention is the girder drop prevention structure according to claim 2, wherein the fixing member (10) is a metal fitting in the vicinity of the end of the girder (2). Is fixed by a buffer bolt (12), and the buffer bolt (12) has an impact relaxation portion (14) in which elastic materials and cloth materials are alternately laminated around the shaft portion (13). Features.
[0015]
A girder drop prevention structure according to claim 7 of the present invention is the girder drop prevention structure according to claim 3, wherein the fixing member (8) fixed in the vicinity of the upper part of the girder support structure (1) is in a planar shape. The second hinge piece (32, 32) erected on the surface of the member (31) has a first hinge piece (23) which is one end of a connecting member (9) which is a metal fitting made of metal. ), And the other end of the connecting member (9) is provided with a circular hole (21) and a space (22) therein, and a buffer pin (12A) is provided in the circular hole (21). ) Is inserted, and the buffer pin (12A) has an impact relaxation portion (14A) in which elastic material and cloth material are alternately laminated around the shaft portion (13A), and within the space (22) The shock absorbing part (14A) of the buffer pin (12A) has an end (60) of the buffer member (5). There characterized in that it is mounted fitted.
[0016]
The girder drop prevention structure according to claim 8 of the present invention is the girder drop prevention structure according to claim 4, wherein the planar member of the fixing member (8) fixed near the end of the adjacent girder (2A). On the second hinge piece (32, 32) erected on the surface of (31), the first hinge piece (23) which is one end of the connecting member (9) which is a metal fitting is a hinge pin (17). The other end of the connecting member (9) is provided with a circular hole (21) and a space (22) therein, and a buffer pin (12A) is provided in the circular hole (21). The buffer pin (12A) has an impact relaxation portion (14A) in which elastic material and cloth material are alternately laminated around the shaft portion (13A), and the shock pin (12A) has the impact relaxation portion (14A) in the space (22). The end portion (60) of the buffer member (5) is attached to the impact relaxation portion (14A) of the buffer pin (12A). Combined, characterized in that it is mounted.
[0017]
The girder drop prevention structure according to claim 9 of the present invention is the girder drop prevention structure according to claim 5, wherein the fixing member (10) is a planar member (10) fixed in the vicinity of the end of the girder (2). The first hinge piece (23), which is one end of the connecting member (11), which is a metal fitting, is provided on the second hinge piece (32, 32) erected on the surface of 31) by the hinge pin (17). A circular hole (21) and an internal space (22) are provided at the other end of the connecting member (9), and a buffer pin (12A) is provided in the circular hole (21). The inserted buffer pin (12A) has an impact buffering portion (14A) in which elastic material and cloth material are alternately stacked around the shaft portion (13A), and the buffer pin (12A) has the shock absorbing portion in the space (22). The end portion (60) of the cushioning member (5) is fitted into the impact relaxation portion (14A) of the pin (12A). And characterized in that it is mounted.
[0018]
A girder drop prevention structure according to claim 10 of the present invention is the girder drop prevention structure according to claim 6, wherein the fixing member (10) is a planar member (10) fixed in the vicinity of the end of the girder (2). The first hinge piece (23), which is one end of the connecting member (11), which is a metal fitting, is provided on the second hinge piece (32, 32) erected on the surface of 31) by the hinge pin (17). A circular hole (21) and an internal space (22) are provided at the other end of the connecting member (9), and a buffer pin (12A) is provided in the circular hole (21). The inserted buffer pin (12A) has an impact buffering portion (14A) in which elastic material and cloth material are alternately stacked around the shaft portion (13A), and the buffer pin (12A) has the shock absorbing portion in the space (22). The end portion (60) of the buffer member (5) is placed on the impact relaxation portion (14A) of the pin (12A). Combined, characterized in that it is mounted.
[0019]
The girder drop prevention structure according to claim 11 of the present invention is the girder drop prevention structure according to claim 1, wherein the end of the buffer member (5) is located near the upper part of the girder support structure (1). The fixing member (8), which is a metal fitting made of a fixed metal, is fixed so as to be rotatable about the axis of the buffer member (5).
[0020]
A girder drop prevention structure according to claim 12 of the present invention is the girder drop prevention structure according to claim 2, wherein the end of the buffer member (5) is connected to another girder adjacent to the girder (2). A fixing member (8), which is a metal fitting fixed in the vicinity of an end of a certain adjacent beam (2A), is fixed so as to be rotatable about the axis of the buffer member (5).
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0022]
FIG. 1 is an explanatory view of a main part showing a configuration of a girder dropping prevention structure according to an embodiment of the present invention.
As shown in FIG. 1, the girder fall prevention structure 101 is provided so as to connect between the pier 1 and the girder 2. The girder 2 is supported on the pier 1 via a support member 3. Further, the girder 2 is adjacent to and continuous with the girder 2A, and the girder 2A is supported on the pier 1 via the support member 3A.
[0023]
The girder dropping prevention structure 101 includes a fixing member 8 fixed to a side surface near the upper end of the pier 1, a fixing member 10 fixed to a lower surface near the end of the girder 2, and the like. The buffer member 5 is arranged, a connecting member 9 that connects one end of the buffer member 5 and the fixing member 8, and a connecting member 11 that connects the other end of the buffer member 5 and the fixing member 10. .
[0024]
Next, a more detailed configuration of the buffer member 5 described above will be described with reference to FIG. As shown in FIG. 2, the buffer member 5 is formed in a substantially round bar shape, and an elastic body 7 such as rubber or synthetic resin is filled in a substantially cylindrical shape around the plurality of rings 6, 6,. Is formed. Each of the rings 6, 6,... Is arranged with a predetermined gap so as not to contact each other, and is fitted to each other to form a chain. Further, the whole of the plurality of rings 6, 6,... Is linearly aligned.
[0025]
In FIG. 2, an oval ring is illustrated as the ring 6, but it may be a circle, an ellipse, or an approximately “B” shape, and may be an approximately “θ” shape or an approximately “day” shape. A connecting member may be attached in the middle as in the case of a shaped member, and generally a closed body in which both ends of a line are closed may be used.
[0026]
For example, the buffer member 5 is configured such that the rings 6, 6,... Are placed in a mold (not shown) or the like in the above-described state, and an elastic body around each of the rings 6, 6,. It is formed by pouring and solidifying raw materials for solidification. In the case where the elastic body 7 is rubber, a vulcanization process for heating in a mold (not shown) is further performed.
[0027]
In the buffer member 5, the rings 6, 6,... Are embedded in the elastic body 7, and the elastic body 7 is also filled in the gaps between the rings. Further, at both ends of the buffer member 5, a part of the ring 60, 60 at the end is exposed to the outside of the elastic body 7, and this portion is substantially annular and can be connected to other members. . Alternatively, another mounting bracket (not shown) is fitted to the rings at both ends of the buffer member 5 so that a part of the mounting bracket (not shown) is exposed to the outside of the elastic body 7. Good.
[0028]
With this configuration, when an axial tensile force acts between the end rings 60, 60 of the buffer member 5, the tensile stress generated in the buffer member 5 by this tensile force is generated inside the buffer member 5. It is transmitted to each ring 6 through the elastic body 7. Therefore, even if impact stress such as seismic force is applied, it is transmitted to each ring 6 after being relaxed and attenuated by the elastic body 7, so that it is different from the case of the conventional bare chain 4 (FIG. 7). Unlikely, it does not break.
[0029]
Next, a more detailed configuration of the connecting member and the fixing member will be described with reference to FIG. FIG. 3 shows the configuration of the connecting member 9 and the fixing member 8 as an example, but the configuration of the connecting member 11 and the fixing member 10 on the side connected to the beam 2 is the same.
As shown in FIG. 3, the connecting member 9 is a metal fitting made of metal such as steel, and a circular hole 21 into which a buffer pin 12A as a connection tool can be attached is provided at one end (left end in the figure). The buffer pin 12A is inserted and attached to the circular hole 21.
[0030]
Further, an impact relaxation portion 14A, which will be described later, is provided on the shaft portion 13A of the buffer pin 12A, and the periphery of the impact relaxation portion 14A is a space 22, in which the end portion of the buffer member 5 is located. The end ring 60 is fitted to and attached to the impact relaxation portion 14A of the buffer pin 12A. For this reason, the buffer member 5 is rotatable around the shaft portion 13A.
[0031]
Further, the other end (right end in the figure) of the connecting member 9 is provided with a first hinge piece 23 formed in a shape forming a part of a disk, and the hinge pin 17 can be inserted into the first hinge piece 23. Circular holes are provided.
On the other hand, the fixing member 8 is a metal fitting made of a metal such as steel, and has two second hinge pieces 32 and 32 (only one of them) formed in a shape forming a part of a disk at the approximate center of the flat plate member 31. Are vertically spaced apart from each other on the surface of the flat plate member 31. The two second hinge pieces 32, 32 are provided with circular holes into which the hinge pins 17 can be inserted.
[0032]
The first hinge piece 23 is inserted into a slit space (not shown) between the two second hinge pieces 32, 32 so that the circular holes communicate with each other, and a round bar shape is formed in the circular hole. After the hinge pin 17 is inserted, the diameter of the hinge pin 17 is increased so that both ends of the hinge pin 17 do not come out of the circular hole. For this reason, the connecting member 9 is rotatable around the hinge pin 17.
[0033]
In addition, the planar member 31 of the fixing member 8 is provided with circular holes 33 on both sides of the second hinge piece 32 into which the buffer bolts 12 as fixing tools can be inserted. Further, bolt holes 34 and 34 are provided in the pier 1 so as to communicate with the circular holes 33 and 33. A female screw is formed on the inner peripheral surface of the bolt hole 34. A buffer bolt 12 is inserted into each of the circular holes 33, and an impact relaxation portion 14, which will be described later, provided on the base side of the shaft portion 13 of the buffer bolt 12 faces the inner wall of the circular hole 33, and the shaft of the buffer bolt 12 is The fixing member 8 is fixed to the pier 1 by the male screw formed on the outer peripheral surface of the tip side of the portion being screwed with the female screw on the inner peripheral surface of the bolt hole 34.
[0034]
Next, a more detailed configuration of the buffer bolt 12 and the buffer pin 12A will be described with reference to FIG.
As shown in FIG. 5A, the buffer bolt 12 includes a shaft portion 13, an impact relaxation portion 14, and a presser plate 15. The impact relaxation part 14 is provided around the base side (hexagonal head side) of the shaft part 13 extending from the hexagonal head, and is formed by alternately laminating elastic materials and cloth materials. . As the elastic material, a band-shaped material made of rubber, synthetic resin or the like is used, and as the cloth material, a woven fabric or a non-woven fabric made of natural fiber or synthetic fiber is used. The presser plate 15 is disposed between the hexagonal head of the bolt and the impact relaxation portion 14. Moreover, the external thread is formed in the outer peripheral surface of the front-end | tip part (end part on the opposite side of a hexagonal head) of the axial part 13 as mentioned above.
[0035]
For example, the impact relaxation portion 14 is a belt-shaped material composed of two layers of an elastic material and a cloth material, which is in contact with the back surface or the surface of the belt-shaped material, and is wound around the shaft portion 13. Then, it is formed into a substantially cylindrical shape by adhesion or heat welding. In the case where the elastic material is rubber, a vulcanization process for heating in a mold (not shown) is further performed.
[0036]
Further, as shown in FIG. 5B, the buffer pin 12A includes a shaft portion 13A extending from a disk-shaped flange portion, an impact relaxation portion 14A, and a cap 16. The shock relaxation part 14A is provided around the base side (disk-shaped flange side) of the shaft part 13A, and its configuration is exactly the same as the shock relaxation part 14 of the buffer bolt 12 described above.
[0037]
A female screw hole 25 is formed in the tip end portion (the end portion on the opposite side of the disc-shaped flange portion) of the shaft portion 13A. The cap 16 has a shaft portion extending from a disk-shaped flange portion, and a male screw that can be screwed into the female screw hole 25 is formed on the outer peripheral surface of the shaft portion of the cap 16.
[0038]
Therefore, when attaching the buffer pin 12A to the circular hole 21 of the connecting member 9 shown in FIG. 3, for example, the portion of the shock relaxation portion 13A of the buffer pin 12A is inserted from the upper right of the circular hole 21 in FIG. In FIG. 3, the buffer pin 12 A can be mounted so as not to come out of the circular hole 21 by screwing the cap 16 into the female screw hole 25 except for the lower left of the circular hole 21.
[0039]
FIG. 4 is a view showing another configuration example of the connecting member and the fixing member in the girder dropping prevention structure shown in FIG. FIG. 4 shows the configuration of another connecting member 9A and the fixing member 8A as an example, but the configuration of the connecting member and the fixing member on the side connected to the beam 2 is the same.
As shown in FIG. 4, the connecting member 9 A is a metal fitting made of a metal such as steel, for example, and an extraction preventing portion 35 is erected vertically (downward in the drawing) on one side of the flat plate member. The member is provided with a circular hole 36 into which the impact reducing portion 14 of the buffer bolt 12 can be inserted. Further, instead of providing the extraction preventing portion 35, the flat plate-like member has a shape larger than the plane projection surface (projection surface in the direction of the fixing member) of the end ring 60 of the buffer member 5 or the mounting bracket (not shown). Also good.
[0040]
The fixing member 8A is a metal fitting made of a metal such as steel, and a circular hole 37 into which the vicinity of the tip of the shaft portion 13 of the buffer bolt 12 can be inserted is provided in the block-like member.
A bolt hole 38 is provided in the pier 1 so as to communicate with the circular hole 37. A female screw is formed on the inner peripheral surface of the bolt hole 38. The buffer bolt 12 can be inserted through the circular hole, and the end ring 60 of the buffer member 5 is fitted and attached to the impact reducing portion 14 of the shaft portion 13 of the buffer bolt 12. Further, the fixing member 8 A is fixed to the pier 1 by the male screw formed on the outer peripheral surface on the tip end side of the shaft portion of the buffer bolt 12 being screwed with the female screw on the inner peripheral surface of the bolt hole 38. ing. Even if comprised in this way, the buffer member 5 can be fixed to the beam 2 or the pier 1.
[0041]
In this case, the buffer member 5 is rotatable around the shaft portion 13 of the buffer bolt 12. Further, the connecting member 9A is provided with an extraction preventing portion 35, or the projection surface of the flat plate member of the connecting member 9A is set larger than the end ring 60 or the mounting bracket (not shown) of the buffer member 5. Therefore, the fitting between the end ring 60 or the mounting bracket (not shown) of the buffer member 5 and the buffer bolt 12 is not released.
[0042]
In the fixing method shown in FIG. 4, the buffer bolt 12 is used so as to serve as both a connector for connecting the buffer member 5 and the connecting member 9A and a fixture for fixing the connecting member 9A to the fixing member 8A. Can do. Alternatively, the fixing member 8A shown in FIG. 4 may be fixed to the pier 1 or the girder 2 with another anchor bolt or the like, and the buffer bolt 12 may be used only as a connection tool. Alternatively, the fixing member 8 A may be formed as a part of the pier 1 or the girder 2, for example, a protrusion, without being a separate member from the pier 1 or the girder 2.
[0043]
Even if the bridge pier 1 vibrates in the vertical direction or the horizontal direction in the figure and the shearing force between the fixing member 8 or 8A and the buffer bolt 12 or the pulling force of the buffer bolt 12 acts due to the above configuration. These forces are alleviated by the impact relaxation portion 14 of the buffer bolt 12 and are transmitted to the buffer member 5 as an axially attenuated tensile force.
Conversely, the tensile force from the buffer member 5 side toward the pier 1 side is relaxed by the impact relaxation portion 14 of the buffer bolt 12 and transmitted to the pier 1 side as a damped shear force, a bolt pull-out force, or the like.
[0044]
Similarly, in FIG. 1, the girder 2 vibrates in the vertical direction or the horizontal direction in the figure, and a shearing force between the fixing member 10 and the buffer bolt 12 for fixing the member, a pulling force of the buffer bolt 12, etc. act. Even so, these forces are alleviated by the shock relaxation portion 14 of the fixing buffer bolt 12 and transmitted to the buffer member 5 as a damped tensile force.
On the contrary, the tensile force from the buffer member 5 side toward the beam 2 side is relaxed by the impact relaxation portion 14 of the buffer bolt 12 and transmitted to the beam 2 side as a damped shear force, a bolt pull-out force, or the like.
[0045]
On the other hand, between the connecting member 9, 9 A or 11 and the buffer member 5, the shock buffering part 14 A of the buffer pin 12 A or the shock buffering part 14 of the buffer bolt 12 is interposed. The facing force or the force from the buffer member 5 is transmitted after being relaxed and attenuated.
Further, as described above, the force transmitted to the buffer member 5 is relaxed and attenuated by the elastic body 7.
[0046]
Therefore, even if impact stress such as seismic force is applied to the girder drop prevention structure 101, it is relaxed and attenuated by the elastic material of the impact mitigating portion 14A or 14 and further by the elastic body 7 in the buffer member 5. Unlike the case of the conventional bare chain 4 (FIG. 7), the end ring 60 of the buffer member 5, the buffer pin 12A, the connecting member 9 or 11, the hinge pin 17, the fixing member 8 or 10, the buffer bolt 12, etc. Will not be damaged or broken.
Moreover, since the buffer member 5 has elasticity, there is also an advantage that the tolerance at the time of installation of the girder dropping prevention structure can be followed.
[0047]
The present invention can be implemented as other embodiments.
For example, you may comprise as shown in FIG. As shown in FIG. 6, this girder drop prevention structure 102 has a chain 4 composed of a plurality of rings 6 A interposed between the connecting member 9 on the pier side of the girder drop prevention structure 101 shown in FIG. 1 and the fixing member 8. It has been made.
[0048]
When the interposition member is arranged in this way, the length can be adjusted by the chain 4 when the installation length of the girder dropping prevention structure is considerably longer than the length of the buffer member 5 or the like.
As the interposition member, those having other configurations can be used, and may be a steel bar, an elongated steel material, or the like. It is also possible to form screws at both ends of the steel rod or the like and attach both ends to the connecting member and the fixing member by screwing.
[0049]
In addition, as a modification, a so-called “turn buckle” -shaped member may be used as the interposed member. If a member such as a turnbuckle is used, the length of the interposed member can be increased or decreased by rotating.
[0050]
Further, as shown in FIG. 6, the interposition member is not only provided between the connecting member on the pier side of the girder fall prevention structure and the fixing member, but also between the connecting member on the girder fall prevention structure and the fixing member. It may be provided between them, or may be provided on both the pier side and the girder side.
[0051]
As yet another embodiment, although not shown, a girder dropping prevention structure having the same configuration as described above may be disposed between the adjacent girder 2A and the girder 2. Moreover, you may arrange | position the girder fall prevention structure of the structure similar to the above both between the beam 2 and the bridge pier 1, and between the adjacent beam 2A and the beam 2. FIG.
[0052]
Note that the upper limit value of the stress at which the buffer member 5 described above can exert an impact mitigating function is not related to the material of the chain embedded in the buffer member 5 according to experiments, and is generally embedded in the buffer member 5. The cross-sectional stress value of the chain is σc = 250 kg / cm 2. From the experimental results, the tensile strength of the buffer member 5 is equal to a value obtained by multiplying the cross-sectional area of the embedded chain by twice the cross-sectional stress value of the chain. For this reason, when the diameter of the chain embedded in the buffer member 5 is d, the tensile strength P of the buffer member 5 is expressed by the following formula:
P = π · d 2 · σ c / 2
Given in.
[0053]
The present invention is not limited to the above embodiments. Each of the embodiments described above is an exemplification, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and has the same operational effects can be used. It is included in the technical scope of the present invention.
[0054]
For example, in each of the above embodiments, the example in which the buffer pin 12A as shown in FIG. 3 or the buffer bolt as shown in FIG. 4 is used as the connecting member has been described, but the present invention is not limited to this. Other structures may be used, for example, a combination of an annular member, a combination of an annular member and a pin, a combination of an annular member and a hook, a connection by screwing, etc. Anything may be used. Moreover, you may make it provide the impact mitigation part similar to the above-mentioned impact mitigation part 14 or 14A in each fitting part.
[0055]
Further, in each of the above-described embodiments, as shown in FIG. 3, an example that can rotate around the axis of the buffer pin 12A and can rotate around the axis of the hinge pin 17, or as shown in FIG. Although the example etc. which can be rotated around the 12 axis | shafts were demonstrated, this invention is not limited to this, In FIG. If comprised in this way, the rotation of any direction of three dimensions will be attained, and even if a torsional force acts on the girder fall prevention structure due to seismic force or the like, no adverse effects or damages are given to each part.
[0056]
【The invention's effect】
As described above, according to the present invention, a gap is arranged so that each of the plurality of closing bodies (6) does not come into contact with each other, and the entire closing body (6) is aligned linearly. One end portion (60) of the buffer member (5) formed in a substantially rod shape by embedding each closed body (6) in the elastic body (7) in a state of being closed and filling the gap with the elastic body (7). Fix near the end of the beam (2), and fix the other end (60) of the buffer member (5) near the top of the beam support structure (1) that supports the beam (2). A chain (4) is provided between the end of the buffer member (5) and the vicinity of the upper part of the girder support structure (1). Alternatively, each of the plurality of closed bodies (6) may be fitted to each other with a gap so that each of the closed bodies (6) does not come into contact with each other, and the entire closed body (6) is aligned in a straight line. One end (60) of the buffer member (5) formed in a substantially rod shape by embedding the closed body (6) in the elastic body (7) and filling the gap with the elastic body (7) is used as the girder (2). The other end (60) of the buffer member (5) is fixed near the end of the adjacent beam (2A), which is another beam adjacent to the beam (2). A chain (4) is provided between the end of the buffer member (5) and the vicinity of the end of the beam (2). As a result, even if an impact external force such as seismic force is applied, it is relaxed and attenuated by the buffer member, and a good girder fall prevention function can always be achieved.
Moreover, since the buffer member (5) has elasticity, there is also an advantage that it is possible to cope with a tolerance at the time of installation of the girder dropping prevention structure.
[Brief description of the drawings]
FIG. 1 is a main part explanatory view showing a configuration of a girder drop prevention structure according to an embodiment of the present invention.
FIG. 2 is a partially broken perspective view showing a configuration of a buffer member in the girder dropping prevention structure shown in FIG. 1;
FIG. 3 is a view showing a configuration example of a connecting member and a fixing member in the girder dropping prevention structure shown in FIG. 1;
4 is a view showing another configuration example of a connecting member and a fixing member in the girder dropping prevention structure shown in FIG. 1. FIG.
5A and 5B are diagrams showing a configuration example of a fixture or connection tool used in the girder dropping prevention structure shown in FIGS. 1 and 2, FIG. 5A is an example configured as a bolt, and FIG. Each example is configured as a pin.
FIG. 6 is a main part explanatory view showing a configuration of a girder drop prevention structure according to another embodiment of the present invention.
FIG. 7 is a main part explanatory view showing a configuration of a conventional girder dropping prevention structure.
[Explanation of symbols]
1 Pier
2,2A digits
3 Bearing members
4 Chain
5 cushioning member
6,6A ring
7 Elastic body
8, 8A, 10 Fixing member
9, 9A, 11 connecting member
12 Buffer bolt
12A Buffer pin
13, 13A Shaft
14, 14A Impact mitigation part
15 Presser plate
16 cap
25 Screw holes
17 Hinge pin
21 circular holes
22 space
23 First hinge piece
31 Flat member
32 Second hinge piece
33 circular holes
34 Bolt hole
35 Extraction prevention part
36, 37 round holes
38 bolt holes
60 end ring
101, 102, 200 girder fall prevention structure

Claims

The respective closed bodies (6) are arranged in a state in which gaps are arranged so as not to contact each other and the closed bodies (6) are linearly aligned with each other so as not to contact each other. One end (60) of the buffer member (5) formed in a substantially rod shape by being embedded in the elastic body (7) and filling the gap also with the elastic body (7) is near the end of the beam (2) The other end (60) of the buffer member (5) is fixed near the upper portion of the beam support structure (1) that supports the beam (2), and the end of the buffer member (5) A girder drop prevention structure characterized in that a chain (4) is provided between the girder support structure (1) and the vicinity of the upper part thereof .

The respective closed bodies (6) are arranged in a state in which gaps are arranged so as not to contact each other and the closed bodies (6) are linearly aligned with each other so as not to contact each other. One end (60) of the buffer member (5) formed in a substantially rod shape by being embedded in the elastic body (7) and filling the gap also with the elastic body (7) is near the end of the beam (2) The other end (60) of the buffer member (5) is fixed in the vicinity of the end of the adjacent beam (2A), which is another beam adjacent to the beam (2), and the buffer member (5) A girder drop prevention structure characterized in that a chain (4) is provided between the end of the girder and the vicinity of the end of the girder (2) .

The girder drop prevention structure according to claim 1, wherein a fixing member (8), which is a metal fitting, is fixed by a buffer bolt (12) near the upper part of the girder support structure (1), and the buffer. The bolt (12) has an impact mitigation part (14) in which elastic materials and cloth materials are alternately laminated around the shaft part (13).

The girder fall prevention structure according to claim 2, wherein a fixing member (8), which is a metal fitting, is fixed by a buffer bolt (12) near the end of the adjacent beam (2A), and the buffer bolt. (12) The girder drop prevention structure characterized in that it has an impact relaxation portion (14) in which elastic materials and cloth materials are alternately laminated around the shaft portion (13).

The girder drop prevention structure according to claim 1, wherein a fixing member (10), which is a metal fitting, is fixed by a buffer bolt (12) near the end of the beam (2), and the buffer bolt ( 12) A girder drop prevention structure characterized by having an impact relaxation portion (14) in which elastic materials and cloth materials are alternately laminated around the shaft portion (13).

The girder drop prevention structure according to claim 2, wherein a fixing member (10), which is a metal fitting, is fixed by a buffer bolt (12) near the end of the beam (2), and the buffer bolt ( 12) A girder drop prevention structure characterized by having an impact relaxation portion (14) in which elastic materials and cloth materials are alternately laminated around the shaft portion (13).

The girder drop prevention structure according to claim 3, wherein the second hinge piece is erected on the surface of the planar member (31) of the fixing member (8) fixed near the upper portion of the girder support structure (1). (32, 32), a first hinge piece (23) which is one end of a connecting member (9) which is a metal fitting made of metal is rotatably attached by a hinge pin (17), and the connecting member (9) A circular hole (21) and an internal space (22) are provided at the other end, and a buffer pin (12A) is inserted into the circular hole (21). The buffer pin (12A) 13A) has an impact relaxation portion (14A) in which elastic materials and cloth materials are alternately stacked around the periphery of 13A). Girder drop prevention, characterized in that end (60) of member (5) is fitted and mounted Structure.

5. The second hinge piece (5) standing on the surface of the planar member (31) of the fixing member (8) fixed near the end of the adjacent beam (2 A) according to claim 4. 32, 32), a first hinge piece (23) which is one end of a connecting member (9) which is a metal fitting made of metal is rotatably attached by a hinge pin (17). A circular hole (21) and a space (22) inside the circular hole (21) are provided at the end, and a buffer pin (12A) is inserted into the circular hole (21). The buffer pin (12A) is connected to the shaft portion (13A). ) Around the shock absorbing portion (14A) of the buffer pin (12A) in the space (22). Girder drop prevention structure characterized in that end (60) of (5) is fitted and mounted. .

The girder drop prevention structure according to claim 5, wherein the second hinge piece (32) erected on the surface of the planar member (31) of the fixing member (10) fixed near the end of the girder (2). 32), the first hinge piece (23), which is one end of the connecting member (11), which is a metal fitting made of metal, is rotatably attached by a hinge pin (17), and the other end of the connecting member (9) Is provided with a circular hole (21) and a space (22) therein, and a buffer pin (12A) is inserted into the circular hole (21), and the buffer pin (12A) is connected to the shaft portion (13A). Is provided with an impact buffering portion (14A) in which elastic materials and cloth materials are alternately laminated, and the buffer member (14A) of the buffer pin (12A) is placed in the buffer member (14A) in the space (22). Girder drop prevention structure characterized in that end portion (60) of 5) is fitted and mounted

The girder drop prevention structure according to claim 6, wherein the second hinge piece (32) erected on the surface of the planar member (31) of the fixing member (10) fixed near the end of the girder (2). 32), the first hinge piece (23), which is one end of the connecting member (11), which is a metal fitting made of metal, is rotatably attached by a hinge pin (17), and the other end of the connecting member (9) Is provided with a circular hole (21) and a space (22) therein, and a buffer pin (12A) is inserted into the circular hole (21), and the buffer pin (12A) is connected to the shaft portion (13A). Is provided with an impact buffering portion (14A) in which elastic materials and cloth materials are alternately laminated, and the buffer member (14A) of the buffer pin (12A) is placed in the buffer member (14A) in the space (22). Girder drop prevention structure characterized in that end portion (60) of 5) is fitted and mounted

The girder fall prevention structure according to claim 1, wherein the end of the buffer member (5) is attached to a fixing member (8) which is a metal fitting fixed near the upper part of the girder support structure (1). A girder fall prevention structure characterized in that it is fixed so as to be rotatable about the axis of the buffer member (5).

The girder fall prevention structure according to claim 2, wherein the end of the buffer member (5) is made of metal fixed in the vicinity of the end of the adjacent girder (2A) which is another girder adjacent to the girder (2). A girder dropping prevention structure characterized in that a fixing member (8), which is a metal fitting, is fixed so as to be rotatable about the axis of the buffer member (5).