Experimental and Numerical Investigation of Wind Characteristics over Mountainous Valley Bridge Site Considering Improved Boundary Transition Sections

Abstract

To study wind characteristics over mountainous terrain, the Xiangjiang Bridge site was employed in this paper. The improved boundary transition sections (BTS) were adopted to reduce the influence of “artificial cliffs” of the terrain model on the wind characteristics at the bridge site over the mountainous terrain. Numerical simulation and experimental investigations on wind characteristics over mountainous terrain with/without BTS were conducted for different cases, respectively. The research results show that the cross-bridge wind speed ratios and wind attack angles at the main deck level vary greatly along the bridge axis, which can be roughly divided into three parts, namely the mountain (I, III) and central canyon areas (II). The cross-bridge wind speed ratios at the main deck level with BTS is generally larger than that without BTS in the central canyon area (II) for most cases, while the opposite trend can be found in wind attack angles. The longitudinal wind speed ratios of the terrain model with BTS at L/4, L/2, and 3L/4 of the bridge length are larger than that of the terrain model without BTS for most cases. In general, the maximum relative error between numerical results and experimental results is about 30% for most cases.

Effect of Topography Truncation on Experimental Simulation of Flow over Complex Terrain

“…Four cases conducted in this study are shown in Figure 3: original topography (OT), without transition section (WTS), Witozinsky transition curve (WTC), and ramp transition curve (RTC). According to previous studies [17,[23][24][25], the performance of the transition curve was evaluated by comparing the characteristics of the flow after the transition section with incoming flow, and the less differences observed, the better. However, the studies of Kilpatrick et al [1] and Lange et al [10] highlighted the significant effect of the leading edge geometry of the terrain model on the flow behavior over the Bolund Hill.…”

“…Huang et al [17] proposed a comprehensive method to evaluate the performance of several curve transitions including the Hu et al [24] improved theoretical curve. Chen et al [25] considered different weights of speed-up factors, wind attack angle, and turbulence intensity by combining a weighted solution based on the correlation degree to ameliorate the evaluation method for determining the optimal form of the transition section.…”

Special Issue on “Buildings and Structures under Extreme Loads”

“…Among others, a extreme natural event is certainly represented by windstorms. In this Special Issue, wind load modelling and design is mainly addressed by [6][7][8], while [9] describes the results of a visual test carried out on a suction caisson that support offshore wind turbines. Finally, the last natural hazard analyzed in the Special Issue is snowdrift.…”

Numerical Investigation of Wind Flow and Speedup Effect at a Towering Peak Extending out of a Steep Mountainside: Implications for Landscape Platforms

“…Han et al [5] proposed a multiscale coupling approach suitable for determining the inlet mean wind speed for numerical simulations of the wind field in mountain gorges. In addition to conducting CFD simulations of wind fields in natural topography, researchers have extensively studied wind flow over typical circular hills [6][7][8][9].…”