公路大跨度桥梁抗风性能评价方法

Evaluation method of wind-resistance capability of large-span bridge on highway

为精确判断公路大跨度桥梁的抗风稳定性等级,在公路大跨度桥梁设计阶段合理选择桥跨布置方案,选取扭弯频率比等结构影响参数和风攻角效应系数等场地参数,共计12个因子作为评价指标。采用模糊数学方法对公路大跨度桥梁的抗风稳定性能进行定量评价,将各种大跨度桥梁的抗风稳定性划分为稳定型、次稳定型、次不稳定型、不稳定型,并以已建大跨度悬索桥为工程算例进行抗风稳定性能的评价分析。结果表明:该研究方法对公路大跨度桥梁抗风稳定性能评定是可行的,经风洞试验结果对比也验证了该分析方法和结论的正确性。

For large-span bridges, in order to accurately evaluate their wind resistance level, the structure parameters, like frequency ratio of torsion and bending, and site factors, such as the effective coefficient of wind angle, totally 12 indexes are chosen as evaluating indicators in a fuzzy mathematics method to implement the evaluation quantitatively. Accordingly, large-span bridges can be classified as stable, second stable, second instable and instable totally four types. An existing large-span suspension bridge is taken as an engineering example to carry out the evaluation analysis of wind resistance level. The results show that the proposed method is feasible to evaluate the wind resistance level for large-span bridges. This conclusion is further strengthened by comparing the numerical simulation results with experimental data of wind tunnel tests. 4 tabs, 7 refs.