Construction of the Shinhamadera Bridge

Following the construction of Aki Bridge with the span length 110 m, in 1968, a large number of Nielsen bridges have been constructed in Japan. Among them Shinhamadera Bridge, having the world's longest span length 254 m, was built in 1991 as a Nielsen-Lohse Bridge with the arch ribs of basket handle type.

In designing this bridge, elasto-plastic and finite displacement analysis as well as ultimate strength tests by using test models were conducted to investigate the effective buckling length of the arch ribs. For aesthetic reasons, the upper lateral bracings without diagonal members consisted of oval and circular cross sections and the ultimate strength of them was verified through experiments on model.

Due to the environmental condition at the construction site, the bridge was completely assembled at the yard and erected in one step by means of a submarine deck barge. This constructional method enabled the constructions fo the bridge to be completed in a short time.