*Shinkansen Br. (ends of vertical stiffener) : TIG dressing [#n36d55dc] *新幹線の橋梁(垂直補剛材の端部):TIGドレッシング[#n36d55dc] **1.Field of application [#m2e87387] > Steel bridge on Shinkansen-railway, Japan. &br; >新幹線の鋼橋 &br; >The Tokaido Shinkansen is the first bullet train system in Japan. This line connects between Tokyo and Osaka 515km in length, has been carrying almost 300 trains a day since 1964. &br; >東海道新幹線はわが国最初の高速鉄道である。東京-大阪間515kmを結び、1964年の開業以来、1日約300車両を支え続けている。 &br; >There are totally 1511 steel bridges, about 27 km in length, in Tokaido Shinkansen. &br; >東海道新幹線には1511橋、延長約27kmの鋼橋がある。 &br; < **2.Circumstances of repair [#b855190e] > Occurrences of fatigue damage began to be reported from around 10 years after having been put in service. Various types of fatigue cracks have been observed in many steel bridges.&br;&br; The causes of fatigue cracks are categorized as follows,&br;&br; >開業から約10年経過した頃から疲労損傷に関して報告がなされていた。多くの橋梁で様々なタイプの疲労き裂は見つかった。 疲労き裂の原因は次のように区分される。 1.stress concentrations due to structural details of members, &br;&br; 2.out of plane displacements in web plates occurring between perpendicularly crossing members such as main girders and cross beams or cross beams and stringers, &br;&br; 3.vibration induced out of plane distortions of web plates by high speed operation of trains. &br;&br; 1.各部材の構造詳細による応力集中&br;&br; 2.主桁と横桁、あるいは横桁と縦桁といった互いに直行する部材で生じるWEBの面外方向の変位&br;&br; 3.列車の高速走行によりWEBが面外方向にねじられることで生じる振動&br;&br; TIG dressing have been applied as a retrofitting method to fatigue cracks of type 2 and type 3, and also as a prevention works to suspicious details. The applied details are the ends of vertical stiffener [[(Fig.1)>#fig1]], the connections between longitudinal ribs and diaphragms in box girder, and the ends of gusset plate on web. TYPE-2とTYPE-3の疲労き裂に対してTIGドレッシングで補修が行われた。また疲労き裂が疑われる部分にも予防的にTIGドレッシングを行った。TIGが行われた構造詳細は、垂直補剛材の端部[[(図.1)>#fig1]]、箱桁の水平リブとダイヤフラムの連結部、およびWEBに取り付けられたガセットプレートの端部である。 CENTER:&aname(fig1);&attachref(Shinkansen_TIG_fig1.jpg);&br; CENTER:Fig.1&br; CENTER:図.1 垂直補剛材の端部&br; < **3.Types of structure [#c28cb71d] > Deck or through type girders, trusses. < >上路・下路の鈑桁橋、トラス橋 **4.Details of loading [#d0de18d6] < Fluctuating loads due to Shinkansen trains traffic. > >新幹線荷重 **5.Description of damage and repair method applied [#pd0d3c8c] > The standard conditions of TIG dressing under flat position are as follows, &br; TIGドレッシングの下向姿勢での標準的条件は次のとおりである。 &br; electrode: Tungsten, 3.2mm in diameter &br; &br; current and voltage: 240A, 13-14V &br; &br; speed: 45-60s/100mm &br; &br; &br; 電極: タングステン, 直径3.2mm &br; &br; 電流と電圧: 240A, 13-14V &br; &br; 溶接速度: 45-60s/100mm &br; &br; These conditions are also applicable to works under other positions. A little lower current is recommendable for horizontal, vertical and overhead positions. &br; これらの条件は他の溶接姿勢に対しても適用できる。 水平、立向および上向姿勢の場合はやや電流を下げることが推奨される。 &br; After TIG dressing works, the configuration and size of bead is examined as shown in [[(Fig.3)>#fig3]], &br; TIGドレッシングの終了後、ビードの状態とサイズの検査を行った[[(図.3)>#fig3]] &br; CENTER:&attachref(Shinkansen_TIG_fig2.gif);&br; CENTER:&attachref(Shinkansen_TIG_fig3.gif);&br; CENTER:&aname(fig3);&attachref(Shinkansen_TIG_fig4.gif);&br; CENTER:Fig.3 &br; CENTER:図.3 TIGドレッシングの状況 &br; TIG dressing works were performed at totally, 18111 details in steel bridges in 1962. the conditions of these details have been observing periodically and no recurrence of fatigue crack until now. &br; TIGドレッシングは合計で18111箇所の構造詳細に適用された。これらの構造詳細は定期的に点検されているが、今までのところ疲労き裂の再発は生じていない。 &br; |COLOR(#000000):CENTER:area|>|>|COLOR(#000000):CENTER:execution|>|>|>|>|COLOR(#000000):CENTER:inspection| |~|COLOR(#000000):CENTER:number of bridges|COLOR(#000000):CENTER:number of girders|COLOR(#000000):CENTER:number of details|COLOR(#000000):CENTER:number of bridges|COLOR(#000000):CENTER:number of girders|COLOR(#000000):CENTER:number of details|COLOR(#000000):CENTER:inspection ratio|COLOR(#000000):CENTER:recurrence| |COLOR(#000000):CENTER:Tokyo|COLOR(#000000):CENTER:3|COLOR(#000000):CENTER:73|COLOR(#000000):CENTER:8486|COLOR(#000000):CENTER:1|COLOR(#000000):CENTER:1|COLOR(#000000):CENTER:38|COLOR(#000000):CENTER:0.4%|COLOR(#000000):CENTER:0| |COLOR(#000000):CENTER:Shizuoka|COLOR(#000000):CENTER:10|COLOR(#000000):CENTER:92|COLOR(#000000):CENTER:4109|COLOR(#000000):CENTER:10|COLOR(#000000):CENTER:67|COLOR(#000000):CENTER:3279|COLOR(#000000):CENTER:80%|COLOR(#000000):CENTER:0| |COLOR(#000000):CENTER:Nagoya|COLOR(#000000):CENTER:12|COLOR(#000000):CENTER:94|COLOR(#000000):CENTER:3026|COLOR(#000000):CENTER:2|COLOR(#000000):CENTER:4|COLOR(#000000):CENTER:160|COLOR(#000000):CENTER:5%|COLOR(#000000):CENTER:0| |COLOR(#000000):CENTER:Osaka|COLOR(#000000):CENTER:8|COLOR(#000000):CENTER:64|COLOR(#000000):CENTER:2490|COLOR(#000000):CENTER:1|COLOR(#000000):CENTER:2|COLOR(#000000):CENTER:68|COLOR(#000000):CENTER:3%|COLOR(#000000):CENTER:0| |COLOR(#000000):CENTER:Total|COLOR(#000000):CENTER:38|COLOR(#000000):CENTER:323|COLOR(#000000):CENTER:18111|COLOR(#000000):CENTER:14|COLOR(#000000):CENTER:77|COLOR(#000000):CENTER:3545|COLOR(#000000):CENTER:20%|COLOR(#000000):CENTER:0| &br; |COLOR(#000000):CENTER:区域|>|>|COLOR(#000000):CENTER:実施|>|>|>|>|COLOR(#000000):CENTER:点検| |~|COLOR(#000000):CENTER:橋梁数|COLOR(#000000):CENTER:桁数|COLOR(#000000):CENTER:構造詳細の数|COLOR(#000000):CENTER:橋梁数|COLOR(#000000):CENTER:桁数|COLOR(#000000):CENTER:構造詳細の数|COLOR(#000000):CENTER:点検比|COLOR(#000000):CENTER:再発生| |COLOR(#000000):CENTER:東京|COLOR(#000000):CENTER:3|COLOR(#000000):CENTER:73|COLOR(#000000):CENTER:8486|COLOR(#000000):CENTER:1|COLOR(#000000):CENTER:1|COLOR(#000000):CENTER:38|COLOR(#000000):CENTER:0.4%|COLOR(#000000):CENTER:0| |COLOR(#000000):CENTER:静岡|COLOR(#000000):CENTER:10|COLOR(#000000):CENTER:92|COLOR(#000000):CENTER:4109|COLOR(#000000):CENTER:10|COLOR(#000000):CENTER:67|COLOR(#000000):CENTER:3279|COLOR(#000000):CENTER:80%|COLOR(#000000):CENTER:0| |COLOR(#000000):CENTER:名古屋|COLOR(#000000):CENTER:12|COLOR(#000000):CENTER:94|COLOR(#000000):CENTER:3026|COLOR(#000000):CENTER:2|COLOR(#000000):CENTER:4|COLOR(#000000):CENTER:160|COLOR(#000000):CENTER:5%|COLOR(#000000):CENTER:0| |COLOR(#000000):CENTER:大阪|COLOR(#000000):CENTER:8|COLOR(#000000):CENTER:64|COLOR(#000000):CENTER:2490|COLOR(#000000):CENTER:1|COLOR(#000000):CENTER:2|COLOR(#000000):CENTER:68|COLOR(#000000):CENTER:3%|COLOR(#000000):CENTER:0| |COLOR(#000000):CENTER:合計|COLOR(#000000):CENTER:38|COLOR(#000000):CENTER:323|COLOR(#000000):CENTER:18111|COLOR(#000000):CENTER:14|COLOR(#000000):CENTER:77|COLOR(#000000):CENTER:3545|COLOR(#000000):CENTER:20%|COLOR(#000000):CENTER:0|