Quantifying the impact of bridge geometry and surrounding terrain: wind effects on bridges

Abstract

The safety and serviceability of long-span bridges can be significantly impacted by wind effects and therefore it is crucial to accurately estimate them during bridge design. This study develops full-scale 3-Dimensional CFD (computational fluid dynamics) simulation models to replicate wind conditions at the Rose Fitzgerald Kennedy Bridge in Ireland. The neglection of bridge geometries and the use of small scales in previous studies are significant limitations, and both the bridge geometry and surrounding terrain are included here at full-scale. Input values for wind conditions are mapped from weather simulations that apply the Weather Research and Forecasting (WRF) model. Wind velocities at four different points calculated by CFD simulations are compared with corresponding data collected from SHM field measurements. The calculated time-averaged wind velocities at four different locations on the bridge are shown to have relative differences of less than 10% to the measured wind velocities by anemometers 90% of the time. The maximum relative difference among all comparisons was only 15%, shown to be partially due to the inclusion of the full bridge and terrain geometry.