Many countries around the world have plans to construct super long-span bridges including a new type of cable-supported bridge. Realization of long-span bridges requires development of new technologies to lead to reduction of the construction costs. For crossing wide straits, application of multi-span suspension bridges over 3 spans is one of economical solutions. However, structural behaviour of this type of bridge has not been fully clarified. In this paper, we focused on the ultimate strength of multi-span suspension bridges, and especially parametric analysis was carried out on the elasto-plastic behavior and load carrying capacity of the suspension bridge systems with different sag ratios and the number of spans.
