Fatigue properties of connection details of steel pipe truss members in the box girder

摘要

In order to reduce the weight of box girders for a long span suspension bridge, structures with thin steel plates have been frequently adopted so far. But these structure types are rather complex. So, more simple structure using thick plates and large-section size members is now suggested. The full-web type diaphragm of the box girder has been usually used. But, in the Kurushima Bridge, one of the Honshu-Shikoku Bridges, the truss type diaphragm has been adopted because of easier maintenance work for the bridge. Fig. 1 shows the plan of improved box girder with steel pipe truss members. In this plan, the number of truss member is decreased by applying large size pipe members. In order to use steel pipes as truss members, connections with transverse ribs have to be durable against fatigue and to be so simple structures that fabricating them is easier. In this study, fatigue test was conducted to observe fatigue properties of the connection detail of the pipe truss structure consisted of inserted ribs to pipe and attached end diaphragm.