Effects of Wind Conditions and Surface Roughness on Ice Accretion on Bridge Stay Cables

Recently, ice accretion on bridge stay cables has frequently occurred, posing serious safety hazards to pedestrians and vehicles. Current research on factors influencing ice accretion on stay cables primarily focuses on ambient temperature, wind speed, cable diameter, and inclination angle. However, there has been limited investigation into key factors such as wind direction and surface roughness of stay cables. Therefore, in this study, icing tests on stay cables were conducted to explore the impact of these factors on ice accretion of stay cable surfaces. The effects of wind direction and surface roughness on ice accretion at both sides of the cable surface were systematically investigated. The results indicate that wind conditions and surface roughness significantly influence the ice accretion of stay cables. Under parallel wind (where the wind direction is parallel to the ground projection of the cable axis), the average ice rib width, unit number of icicles, and maximum icicle length of the stay cables are 6.92–8.51 mm, 3.5–5.5 icicles/m, and 84–157 mm, respectively. These values all exceed those under perpendicular wind (where the wind direction is perpendicular to the ground projection of the cable axis), which are 6.04–7.05 mm, 0.5–3.5 icicles/m, and 35–47 mm, respectively. All icing parameters increase with wind speed. Ice distribution shows significant asymmetry between Sides A and B under perpendicular wind but is uniform under parallel wind. When the surface roughness parameter (Ra) is increased from Ra1 = 1.6 μm to Ra4 = 6.4 μm, the average ice rib width growth rate reached 37.0%–63.6% for cables with helical fillets and 17.3%–44.7% for those without. Cables with helical fillets exhibit a larger total ice accretion mass despite a lower growth rate (31.0%–61.1% versus 53.0%–143.2%). The study demonstrates that parallel wind, higher wind speed, increased roughness, and helical fillets all promote ice accretion on stay cables.