关键词: 复杂山区, 风场特性, 桥隧连接段, 数值模拟, 风攻角

Abstract:

To study the spatial characteristics of the wind field at the bridge-tunnel connection section in complex mountainous areas, the mountainous terrain within 8km in diameter at the junction of G318 and S217 is selected as the research background. The mountain models of five lengths of bridge-tunnel connection section are established based on the digital elevation model. The spatial distribution characteristics of the wind field at the bridge-tunnel connection section under 16 kinds of flow conditions are obtained by using the numerical simulation method. The results show that, under the condition of the approximately constant mountain slope, affected by the actual complex terrain, there are some differences in the characteristics of transverse wind speed, vertical wind profile, and wind attack angle at the bridge-tunnel connection sections with different lengths, but the overall trend is similar. When the incoming flow is perpendicular to the bridge-tunnel connection section, the wind speed at the midspan is the maximum due to the canyon acceleration effect. This acceleration effect increases with the decrease of the bridge-tunnel connection section length. The incoming flow in other working conditions is reduced due to the reduction effect of high and steep mountains on both sides, and the wind speed is the minimum along the bridge-tunnel connection section. High and steep mountains and river bends affect the vertical transverse wind speed distribution. In the canyon with lower elevation, the shorter the length of the bridge-tunnel connection section, the more significant the impact. The characteristics of the wind angle of attack are also greatly affected by the terrain, and the overall performance is dominated by the negative angle of attack. The variation rules obtained from the numerical simulation of the wind field at the bridge-tunnel connection section in complex mountainous areas can provide some guidance and reference for studying traffic safety at the bridge-tunnel connection section.

Key words: complex terrain, wind characteristic, bridge and tunnel connection section, numerical simulation, wind attack angle