Flutter control by bridge configuration of long-span suspension bridge

In order to clarify optimum configuration of a long-span suspension bridge from the viewpoints of flutter performance and construction cost, an analytical study on bridge configuration was conducted. The study also tried to find the effect of tower type and an application of high strength steel wire on the flutter critical speed. The analysis showed that a side-span ratio and sag ratio have the significant effects. In the case of the center span of a bridge being constant, the optimum side-span ratio is around 0.3 - 0.35, however in the case of total bridge length being constant, a larger side-span ratio was found to have a better flutter performance and lower cost. Higher stiffness (concrete or A-shaped) tower will be more effective with respect to flutter performance. In addition, application of high strength steel wire reduced the flutter critical speed but also significantly reduced the total cost.