Dry galloping characteristics and its mechanism of inclined/yawed cables

Mechanism of dry galloping of inclined cable of cable-stayed bridges is described in relation to Karman vortex mitigation. Furthermore, the role of Scruton number Sc on reduced critical velocity Vrcr of the dry galloping is investigated for practical use basing on wind tunnel tests and field observations of dry galloping or pseudo-galloping, which is classified as cable vibration with rain-state but response amplitude is abnormally large. It is verified that as far as the divergent-type of dry galloping, the design criterion subject to Sc-Vrcr proposed by FHWA (Federal Highway Administration of U.S.) seems to be reasonable for practical use, on the other hand, for the unsteady dry galloping, the Saito criterion for Sc-Vrcr diagram seems to be reasonable.