Numerical Simulation of Wind Fields at the Bridge Site in Mountain-Gorge Terrain Considering an Updated Curved Boundary Transition Section

Abstract

To investigate the characteristics of wind fields at the bridge site in mountain-gorge terrains more accurately and rationally, an updated curved boundary transition section (BTS) was proposed in this study. The flow transition efficiency considering the updated curved BTS was first investigated and compared with those in previous studies. Then a mountain-gorge terrain model in which a long-span bridge straddles was configured as a typical numerical example by establishing two different BTSs in the computational domain for comparison purpose. Furthermore, the effects of different BTSs on the characteristics of wind fields at the bridge site with two different ranges of terrain region were comparably investigated. The results show that the updated curved BTS is very user-friendly with a straightforward expression and has a better flow transition efficiency than those reported previously. The wind speeds at the bridge site with the updated curved BTS outperform those with the ramp BTS. An appropriate shape of BTS can probably be more important than the size factor of the terrain region in terms of predicating the characteristics of wind fields at the bridge site in such mountain-gorge terrains. It is hoped that this updated curved BTS can serve as basics for analyzing the wind fields at the bridge site in mountain-gorge terrains, which will be of benefit to investigate the structure performance under wind loads not only in the design stage but also in the service stage.