Abstract Two ultra-long-span cable-stayed bridge schemes, identical in deck configuration and main span length of 1500 m but differ in steel and carbon fiber reinforced polymer (CFRP) stay cables, are first designed based on the equivalent strength principle. Finite element analyses are then conducted to investigate wind-resistant performances of both schemes, including static structural behaviors, mean wind-induced deflections, buffeting responses, flutter instability, wind-induced cable resonance, vortex-induced cable vibrations and wind-induced local bending deformations of the stay cables. The results indicate that the using of CFRP cables reduces significantly the wind loads, which account for a major part in the total wind loads developed on the entire structure. As a result, mean wind-induced global deflections of CFRP scheme are notably reduced compared with the steel scheme. In terms of buffeting, results of the CFRP scheme are 12%, 14%, and 28% lower than those of the steel one in vertical, torsional, and lateral directions, respectively. No substantial difference is observed between the two schemes regarding the bridge deck flutter stability. As far as wind-induced cable resonance is concerned, the CFRP scheme is obviously superior to the steel one, exhibiting a much lower likelihood of buffeting-induced resonances due to much higher natural frequencies of stay-cables. As far as the vortex-induced vibration is concerned, however, CFRP stay-cables are less favorable than steel ones. Finally, aiming at the inherent shortcoming of CFRP cables, wind-induced bending deformations at anchorage ends are analyzed. The results show bending angles of the CFRP cables are significantly lower than those of the steel cables. With a wind speed as high as 52.97 m/s considered, CFRP stay cables experience only low-to-moderate bending angles, resulting in no significant strength reductions and posing no substantial threat to the structural safety.
Nie et al. (Wed,) studied this question.