Steel bridge on roadway bridge(intersection of a valve rib and a crossbeem) 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 a valve rib and a crossbeem) へ行く。
Steel bridge on roadway bridge(intersection of a valve rib and a crossbeem) の差分を削除

*•Steel bridge on roadway bridge(intersection of a valve rib and a crossbeem)[#f0cf1b7b]
*Steel bridge on roadway bridge(intersection of a valve rib and a crossbeem)[#f0cf1b7b]

**1.Field of application [#xb24e840]

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

**2.Circumstances of repair [#w638d500]

>Fatigue cracks were detected on welded joints between vertical stiffeners and orthotropic deck plate in 2005 after 9 years of service.&br;

**3.Types of structure [#tfd342b1]
>The outline of the bridge structure is as follows.&br;
-Bridge length : 165.0m
-Span length : 49.3+75.0m+44.6m
-Structure : Box girder bridge with orthotropic deck system
-Structural steel : SM490Y 

**4.Details of loading [#y50e36b5]
>Fluctuating loads due to highway live load.

**5.Description of damage [#ycceae98]
>Fatigue cracks were detected on welded joints between vertical stiffners and orthotropic deck plate.Type-A cracks initiated from the orthotopic deck side toe of the weld bead and propagated at a orthotropic deck. Type-B cracks initiated from the vertical stiffeners side toe of the weld bead and propagated at orthotopic deck after penetrating through the weld bead([[Fig.1>#fig1]]). .
&br;
CENTER:&aname(fig1);&attachref(./type-a-b.jpg,35%);&br;
&br;
CENTER:Type-A　　　　　　　　　　　　　　　　　　　　　　　　　Type-B &br;
&br;
CENTER:Fig.1 Crack location &br;
&br;
>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 [#b01beb0a]

>Retrofitting measures were cutting treating of semicircle at the vertical stiffeners([[Fig.2>#fig2]]).
&br;
&br;
CENTER:&aname(fig2);&attachref(./cutting.jpg,50%);&br;
&br;
CENTER:Fig.2 Cutting treating of semicircle &br;
&br;
**Reference [#cafe5c9d]
>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)
&br;
&br;