大跨度曲线人行桥舒适度评估与减振研究

Research on Comfort Level Evaluation and Vibration Reduction of Long-Span Curved Footbridge

摘要:

大跨度曲线人行桥通常结构基频较低，难以通过结构构造调整来优化基频，导致人致振动问题尤为突出。以某城市大跨度曲线钢结构人行桥为例，利用空间有限元设计软件，结合国内外人行桥舒适度评价标准，在规定的人群荷载激励下，对桥梁设置TMD（tuned mass damper）阻尼器之前与之后的峰值加速度响应结果进行对比分析，并且按照国内与国外标准不同的评价规则划分行人舒适度等级。研究表明，在一定的成本控制限制条件下，选择合适的阻尼器参数和布置位置能够大幅降低振动峰值加速度，有效改善行人舒适度，此方式对于类似大跨度曲线人行桥减振设计能够提供很好的借鉴价值，同时也验证了国内人行桥修订版规范的适用性。

Abstract:

Long-span curved footbridges usually have a relatively low fundamental frequency of structure, making it difficult to optimize the fundamental frequency through structural adjustment, which leads to particularly prominent human-induced vibration problems. Taking a long-span curved steel structure footbridge in a certain city as an example, the author used spatial finite element design software and combined domestic and international footbridge comfort level evaluation standards. Under the specified crowd load excitation, the peak acceleration response results of the bridge before and after the installation of TMDs(tuned mass dampers) were compared and analyzed, and the comfort level was classified according to different domestic and international evaluation standards. Research shows that under certain cost control constraints, choosing appropriate damper parameters and layout positions can significantly reduce the peak vibration acceleration and effectively improve pedestrian comfort. This approach can provide good reference value for the vibration reduction design of similar long-span curved footbridges and also verifies the applicability of the revised domestic footbridge standards.