防撞护栏对不同地表类型下钝体箱梁行车风环境影响的数值模拟研究OA

The traffic wind environment of a two-lane bluff box girder is closely related to its bluff body by-passing characteristics.The height and configuration of a crash barrier are the key parameters to regulate the traffic wind environment.Based on computational fluid dynamics(CFD),the bridge deck wind profiles,crosswind discount factors,and static aerodynamic coefficients with 28 types of solid crash barriers and 8 types of combined crash barriers were systematically analyzed by the k-ω SST turbulence model.The influence law of terrain category on the minimum wind-resistant height of the crash barrier was also explored.Consider-ing the degree of improvement in wind environment,wind load cost,and construction price,a comprehensive evaluation indicator was introduced to identify the optimal crash barrier design.The research results indicate that the increase of the height of the crash barrier can significantly increase the height of the return flow area above the bluff box girder,leading to the improvement of the traffic wind environment,but it also increases the drag force of the bridge.Terrain roughness has a notable impact on the minimum wind-resistant height of the crash barrier.The minimum wind-resistant heights of the solid crash barriers and the combined crash barriers under Category D terrain are increased by 14.0%and 25.7%than those under Category A terrain,respec-tively.For the cable-stayed bridge with the bluff box girder studied,the solid crash barrier with a height of 1.64 m under Category A terrain has the best comprehensive index.