Wind analysis of pipeline suspension bridges

Two pipeline suspension bridges, with main spans of 850 feet (259.1 meters) and 1008 feet (307.2 meters), were investigated for wind load responses. Previously published findings indicated that vortex shedding was the cause of vertical wind oscillations of the former span which occurred shortly after its completion. These wind oscillations are now prevented by diagonal cable stays that have substantially increased structure damping. For the latter span, which has no diagonal cable stays, the relatively rigid profile of the suspended pipe is the likely reason why vertical wind oscillations of this span have not occurred. The responses of new suspended pipe profiles, which further increase pipe rigidity and hence decrease the risk of vertical wind oscillations of pipeline suspension bridges, are reported here. Additional investigations of the two original spans and new studies of two other pipeline suspension bridges are currently being conducted.