Analysis of Dynamic Response and Driving Safety of Ultra-High Pier Long-Span Rigid-Frame Bridge Under Nonstationary Wind

To study the influence of nonstationary wind on the dynamic response and driving safety of ultra-high pier long-span rigid-frame bridge, based on the wind-vehicle-bridge coupling system, a seven-span continuous rigid-frame bridge in a mountainous area was taken as the engineering background. First, the vertical deflection and acceleration of the bridge under nonstationary wind, stationary wind, and no wind were calculated. Second, the statistical method was used to calculate the wheel’s converted pressure at various wind velocities. Finally, the critical overturning wind velocity and vehicle speed under nonstationary wind were calculated. The results indicate that at low wind velocities, the difference between stationary and nonstationary wind effects on the bridge’s dynamic response is minimal. However, as the wind velocity increases, nonstationary wind has a greater impact on the bridge’s dynamic behavior compared to stationary wind. Specifically, at wind velocities of 15, 20, and 25[Formula: see text]m/s, the wheel’s converted pressure under stationary wind is 1.03, 1.09, and 1.23 times that of nonstationary wind, respectively. This suggests that higher wind velocities make nonstationary wind more likely to cause vehicle overturning than stationary wind. When the wind velocity exceeds 28[Formula: see text]m/s, the speed limit should be imposed on vehicles crossing the bridge.