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*Sozuka-Ohhashi (at suspension member) [#w01a59d1] **1.Field of application [#q8f70363] >Sozuka-Ohhashi over dam lake which is located between Ohtsu and Uji, Shiga-prefecture, Japan.&br; **2.Circumstances of Repair [#i3e5eb1f] >Fatigue fractures were found at the weld of the suspension members, which connected the lower lateral bracing with the stringer, in 1981 after 15 years of service. >This type of damage cases can be often seen at the arch, truss bridge and through-type deck girder bridge which have the same detail. The lower lateral bracing of these bridges are almost rivet or weld connected to the stringers as same as Sozuka-Ohhashi. Generally, the damage occurs in the rivet connection or weld connection. For such kinds of damage, repair is frequently performed by replacing the original joints to the high strength bolts. **3.Types of structure [#t6dbbd4b] >This bridge is the 2-hinge rib arch through bridge of which arch span length is 106m long. The structure of the bridge can be seen in case of "Sozuka-Ohhashi, Ohtsu, Shiga-prefecture (at member connection)". The suspension members were weld connected to the stringer bottom flanges in order to support the lower lateral members. **4.Details of loading [#de522056] >Fluctuating loads due to vehicles live load. **5.Description of damage [#e2ef1a8d] >Fatigue fracture initiated from the weld beads of the suspension members at the lower lateral bracing connections with the stringer ([[Fig.1>#fig1]]). There were some cases that the damage occurred in the rivet locations of the suspension members. Cause of fatigue cracks is as follows. Differential displacement between the main girder and the floor system. &br; &br; CENTER:&aname(fig1);&attachref(Sozuka23.gif);&br; &br; CENTER:Fig.1 Fatigue fracture of the suspension member.&br; &br; &br; **6.Repair method applied [#g0ffe0e6] >Before repairing, the removal of the original members was carried out by frame-cutting and weld area remained was ground smooth ([[Fig.2>#fig2]]). Repair of parts subjected to damaging was to replace to the new members by using high strength bolts ([[Fig.3>#fig3]]). &br; &br; CENTER:&aname(fig2);&attachref(Sozuka24.gif);&br; &br; CENTER:Fig.2 Grinding area.&br; &br; &br; CENTER:&aname(fig3);&attachref(Sozuka25.gif);&br; &br; CENTER:Fig.3 Replacement of the suspension member.&br; &br; &br; **Reference [#ff51a569] >Takada H. and Mizumoto M.,Report on Strengthening Construction of Sozuka-Ohhashi. Yokogawa Bridge Works Technical Report, No.19,1990 >Takada H. and Mizumoto M.,Report on Strengthening Construction of Sozuka-Ohhashi. '''Yokogawa Bridge Works Technical Report''', No.19,1990 &br; &br;
