Steel bridge on roadway bridge(intersection of valve ribs and crossbeems) の変更点

追加された行はこの色です。
削除された行はこの色です。
Steel bridge on roadway bridge(intersection of valve ribs and crossbeems) へ行く。
Steel bridge on roadway bridge(intersection of valve ribs and crossbeems) の差分を削除

*Steel bridge on Hanshin Expressway (welded joints between vertical stiffeners and orthotropic deck plate) [#p3adfebb]

**1.Field of application [#fc9f85ba]

>Steel bridge of Route 43, Japan.&br;

**2.Circumstances of repair [#y32485b5]

>Fatigue cracks at intersection of valve ribs and crossbeems were found.

**3.Types of structure [#s22f0672]
>The outline of the bridge structure is as follows([[Fig.1>#fig1]])..&br;
>The outline of the bridge structure is as follows([[Fig.1>#fig1]]).&br;
-Bridge length : 211.0m
-Span length : 60.0m+91.0m+60.0m
-Structure : Box girder bridge with orthotropic deck system

**4.Details of loading [#l6e4d7ad]
>Fluctuating loads due to vehicles live load.

**5.Description of damage [#k7bc89d3]
>Fatigue cracks were detected on boxing weld joints between bottom of valve ribs and web plates of crossbeem.Cracks initiated from the toe of the boxing weld joints and propagated at the web plates of the crossbeem([[Fig.1>#fig1]]).
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CENTER:&aname(fig1);&attachref(./type-a-b.jpg,35%);&br;
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CENTER:Type-A　　　　　　　　　　　　　　　　　　　　　　　　　Type-B &br;
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CENTER:Fig.1 Crack location &br;
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>Cause of fatigue cracks was as follows:&br;
-Localized stress concentration which resulted from the restraint of the deck plate deflection due to the wheel load.

**6.Repair method applied [#cfd751ca]

>Retrofitting measures were cutting treating of semicircle at the vertical stiffeners([[Fig.2>#fig2]]).
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CENTER:&aname(fig2);&attachref(./cutting.jpg,50%);&br;
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CENTER:Fig.2 Cutting treating of semicircle &br;
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**Reference [#v2fdca89]
>Yoshihiko TAKADA,Yoriko KAWAKAMI,Yuji SAKAI,Masahiro SAKANO, Study on retrofit measures in weld of vertical stiffener cutting treating of the semicircle in orthotropic steel deck, '''STEEL CONSTRUCTION ENGINEERING''', Vol.16, No.62,2009.(In Japanese)
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