Experimental investigation on mechanism and mitigation of rain–wind-induced vibration of stay cables

Abstract

Rain–wind-induced vibration is one of the most severe vibrations for stay cables in long-span bridges. To clarify the mechanism of cable vibration and its aerodynamic countermeasures under two unfavorable refined rain–wind environments, wind tunnel tests were systematically conducted on cable sectional models with various surface processing schemes, including smooth surface, spiral protuberances, spiral dimples, straight dimples, and polyurea painting. Rivulet formation by cable vibrations under two unfavorable environments are discussed, and differences between mechanisms are preliminarily classified. The above schemes were investigated to determine their effectiveness in mitigating vibrations. Spiral protuberances had significant mitigating effects on cable vibration, and spiral protuberances of 0.011 height and 0.43 intervals nondimensionalized by the diameter of the cable were good enough to prevent rain–wind-induced vibrations. The effectiveness of dimples strongly depended on their arrangement on the cable surfaces. Polyurea painting reduced the possibility of large-amplitude vibration, but it also changed the unfavorable environmental conditions.