矮塔斜拉桥混凝土箱梁施工阶段风荷载影响分析

Wind load effect on low-pylon cable-stayed bridge during construction of box girders

南澳大桥主桥的混凝土箱梁施工中,当地风环境条件极其恶劣,在成桥最大悬臂状态时,对风荷载作用下的结构动力特性进行计算分析。在无类似相关经验和参数选取的条件下,通过施工前期观测统计,合理选取风荷载参数,采取安全可靠的方案措施,科学合理控制施工最大允许风速,有效避免了竖向涡激共振对浇筑混凝土质量的影响。

During the construction of concrete box girders for the main part of Nan＇ao Bridge, the local wind conditions wereextremely bad. We analyzed the dynamic characteristics of the structure under the effect of wind loading when the bridge was inits maximum cantilevering position. As there were no similar experience and parameters available, parameters for wind loadswere rationally selected on the basis of the data of observation made in the early stage of the project. Safe and reliable measureswere taken and the highest allowable wind velocity was scientifically and rationally controlled to effectively avoid the effect ofthe vertical vortex induced resonance on the quality of concrete.